1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #include "opt_inet.h"
34 #include "opt_inet6.h"
35 #include "opt_ipsec.h"
36 #include "opt_kern_tls.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/arb.h>
41 #include <sys/callout.h>
42 #include <sys/eventhandler.h>
43 #ifdef TCP_HHOOK
44 #include <sys/hhook.h>
45 #endif
46 #include <sys/kernel.h>
47 #ifdef TCP_HHOOK
48 #include <sys/khelp.h>
49 #endif
50 #ifdef KERN_TLS
51 #include <sys/ktls.h>
52 #endif
53 #include <sys/qmath.h>
54 #include <sys/stats.h>
55 #include <sys/sysctl.h>
56 #include <sys/jail.h>
57 #include <sys/malloc.h>
58 #include <sys/refcount.h>
59 #include <sys/mbuf.h>
60 #include <sys/priv.h>
61 #include <sys/sdt.h>
62 #include <sys/socket.h>
63 #include <sys/socketvar.h>
64 #include <sys/protosw.h>
65 #include <sys/random.h>
66
67 #include <vm/uma.h>
68
69 #include <net/route.h>
70 #include <net/route/nhop.h>
71 #include <net/if.h>
72 #include <net/if_var.h>
73 #include <net/if_private.h>
74 #include <net/vnet.h>
75
76 #include <netinet/in.h>
77 #include <netinet/in_fib.h>
78 #include <netinet/in_kdtrace.h>
79 #include <netinet/in_pcb.h>
80 #include <netinet/in_systm.h>
81 #include <netinet/in_var.h>
82 #include <netinet/ip.h>
83 #include <netinet/ip_icmp.h>
84 #include <netinet/ip_var.h>
85 #ifdef INET6
86 #include <netinet/icmp6.h>
87 #include <netinet/ip6.h>
88 #include <netinet6/in6_fib.h>
89 #include <netinet6/in6_pcb.h>
90 #include <netinet6/ip6_var.h>
91 #include <netinet6/scope6_var.h>
92 #include <netinet6/nd6.h>
93 #endif
94
95 #include <netinet/tcp.h>
96 #ifdef INVARIANTS
97 #define TCPSTATES
98 #endif
99 #include <netinet/tcp_fsm.h>
100 #include <netinet/tcp_seq.h>
101 #include <netinet/tcp_timer.h>
102 #include <netinet/tcp_var.h>
103 #include <netinet/tcp_ecn.h>
104 #include <netinet/tcp_log_buf.h>
105 #include <netinet/tcp_syncache.h>
106 #include <netinet/tcp_hpts.h>
107 #include <netinet/tcp_lro.h>
108 #include <netinet/cc/cc.h>
109 #include <netinet/tcpip.h>
110 #include <netinet/tcp_fastopen.h>
111 #include <netinet/tcp_accounting.h>
112 #ifdef TCPPCAP
113 #include <netinet/tcp_pcap.h>
114 #endif
115 #ifdef TCP_OFFLOAD
116 #include <netinet/tcp_offload.h>
117 #endif
118 #include <netinet/udp.h>
119 #include <netinet/udp_var.h>
120 #ifdef INET6
121 #include <netinet6/tcp6_var.h>
122 #endif
123
124 #include <netipsec/ipsec_support.h>
125
126 #include <machine/in_cksum.h>
127 #include <crypto/siphash/siphash.h>
128
129 #include <security/mac/mac_framework.h>
130
131 #ifdef INET6
132 static ip6proto_ctlinput_t tcp6_ctlinput;
133 static udp_tun_icmp_t tcp6_ctlinput_viaudp;
134 #endif
135
136 VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
137 #ifdef INET6
138 VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
139 #endif
140
141 VNET_DEFINE(uint32_t, tcp_ack_war_time_window) = 1000;
142 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_timewindow,
143 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_ack_war_time_window), 0,
144 "Time interval in ms used to limit the number (ack_war_cnt) of challenge ACKs sent per TCP connection");
145 VNET_DEFINE(uint32_t, tcp_ack_war_cnt) = 5;
146 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, ack_war_cnt, CTLFLAG_VNET | CTLFLAG_RW,
147 &VNET_NAME(tcp_ack_war_cnt), 0,
148 "Maximum number of challenge ACKs sent per TCP connection during the time interval (ack_war_timewindow)");
149
150 struct rwlock tcp_function_lock;
151
152 static int
sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)153 sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
154 {
155 int error, new;
156
157 new = V_tcp_mssdflt;
158 error = sysctl_handle_int(oidp, &new, 0, req);
159 if (error == 0 && req->newptr) {
160 if (new < TCP_MINMSS)
161 error = EINVAL;
162 else
163 V_tcp_mssdflt = new;
164 }
165 return (error);
166 }
167
168 SYSCTL_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
169 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
170 &VNET_NAME(tcp_mssdflt), 0, &sysctl_net_inet_tcp_mss_check, "I",
171 "Default TCP Maximum Segment Size");
172
173 #ifdef INET6
174 static int
sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)175 sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
176 {
177 int error, new;
178
179 new = V_tcp_v6mssdflt;
180 error = sysctl_handle_int(oidp, &new, 0, req);
181 if (error == 0 && req->newptr) {
182 if (new < TCP_MINMSS)
183 error = EINVAL;
184 else
185 V_tcp_v6mssdflt = new;
186 }
187 return (error);
188 }
189
190 SYSCTL_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
191 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
192 &VNET_NAME(tcp_v6mssdflt), 0, &sysctl_net_inet_tcp_mss_v6_check, "I",
193 "Default TCP Maximum Segment Size for IPv6");
194 #endif /* INET6 */
195
196 /*
197 * Minimum MSS we accept and use. This prevents DoS attacks where
198 * we are forced to a ridiculous low MSS like 20 and send hundreds
199 * of packets instead of one. The effect scales with the available
200 * bandwidth and quickly saturates the CPU and network interface
201 * with packet generation and sending. Set to zero to disable MINMSS
202 * checking. This setting prevents us from sending too small packets.
203 */
204 VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
205 SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW,
206 &VNET_NAME(tcp_minmss), 0,
207 "Minimum TCP Maximum Segment Size");
208
209 VNET_DEFINE(int, tcp_do_rfc1323) = 1;
210 SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | CTLFLAG_RW,
211 &VNET_NAME(tcp_do_rfc1323), 0,
212 "Enable rfc1323 (high performance TCP) extensions");
213
214 /*
215 * As of June 2021, several TCP stacks violate RFC 7323 from September 2014.
216 * Some stacks negotiate TS, but never send them after connection setup. Some
217 * stacks negotiate TS, but don't send them when sending keep-alive segments.
218 * These include modern widely deployed TCP stacks.
219 * Therefore tolerating violations for now...
220 */
221 VNET_DEFINE(int, tcp_tolerate_missing_ts) = 1;
222 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tolerate_missing_ts, CTLFLAG_VNET | CTLFLAG_RW,
223 &VNET_NAME(tcp_tolerate_missing_ts), 0,
224 "Tolerate missing TCP timestamps");
225
226 VNET_DEFINE(int, tcp_ts_offset_per_conn) = 1;
227 SYSCTL_INT(_net_inet_tcp, OID_AUTO, ts_offset_per_conn, CTLFLAG_VNET | CTLFLAG_RW,
228 &VNET_NAME(tcp_ts_offset_per_conn), 0,
229 "Initialize TCP timestamps per connection instead of per host pair");
230
231 /* How many connections are pacing */
232 static volatile uint32_t number_of_tcp_connections_pacing = 0;
233 static uint32_t shadow_num_connections = 0;
234 static counter_u64_t tcp_pacing_failures;
235 static counter_u64_t tcp_dgp_failures;
236 static uint32_t shadow_tcp_pacing_dgp = 0;
237 static volatile uint32_t number_of_dgp_connections = 0;
238
239 static int tcp_pacing_limit = 10000;
240 SYSCTL_INT(_net_inet_tcp, OID_AUTO, pacing_limit, CTLFLAG_RW,
241 &tcp_pacing_limit, 1000,
242 "If the TCP stack does pacing, is there a limit (-1 = no, 0 = no pacing N = number of connections)");
243
244 static int tcp_dgp_limit = -1;
245 SYSCTL_INT(_net_inet_tcp, OID_AUTO, dgp_limit, CTLFLAG_RW,
246 &tcp_dgp_limit, -1,
247 "If the TCP stack does DGP, is there a limit (-1 = no, 0 = no dgp N = number of connections)");
248
249 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pacing_count, CTLFLAG_RD,
250 &shadow_num_connections, 0, "Number of TCP connections being paced");
251
252 SYSCTL_COUNTER_U64(_net_inet_tcp, OID_AUTO, pacing_failures, CTLFLAG_RD,
253 &tcp_pacing_failures, "Number of times we failed to enable pacing to avoid exceeding the limit");
254
255 SYSCTL_COUNTER_U64(_net_inet_tcp, OID_AUTO, dgp_failures, CTLFLAG_RD,
256 &tcp_dgp_failures, "Number of times we failed to enable dgp to avoid exceeding the limit");
257
258 static int tcp_log_debug = 0;
259 SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
260 &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
261
262 /*
263 * Target size of TCP PCB hash tables. Must be a power of two.
264 *
265 * Note that this can be overridden by the kernel environment
266 * variable net.inet.tcp.tcbhashsize
267 */
268 #ifndef TCBHASHSIZE
269 #define TCBHASHSIZE 0
270 #endif
271 static int tcp_tcbhashsize = TCBHASHSIZE;
272 SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
273 &tcp_tcbhashsize, 0, "Size of TCP control-block hashtable");
274
275 static int do_tcpdrain = 1;
276 SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0,
277 "Enable tcp_drain routine for extra help when low on mbufs");
278
279 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | CTLFLAG_RD,
280 &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
281
282 VNET_DEFINE_STATIC(int, icmp_may_rst) = 1;
283 #define V_icmp_may_rst VNET(icmp_may_rst)
284 SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | CTLFLAG_RW,
285 &VNET_NAME(icmp_may_rst), 0,
286 "Certain ICMP unreachable messages may abort connections in SYN_SENT");
287
288 VNET_DEFINE_STATIC(int, tcp_isn_reseed_interval) = 0;
289 #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
290 SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW,
291 &VNET_NAME(tcp_isn_reseed_interval), 0,
292 "Seconds between reseeding of ISN secret");
293
294 static int tcp_soreceive_stream;
295 SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
296 &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
297
298 VNET_DEFINE(uma_zone_t, sack_hole_zone);
299 #define V_sack_hole_zone VNET(sack_hole_zone)
300 VNET_DEFINE(uint32_t, tcp_map_entries_limit) = 0; /* unlimited */
301 static int
sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS)302 sysctl_net_inet_tcp_map_limit_check(SYSCTL_HANDLER_ARGS)
303 {
304 int error;
305 uint32_t new;
306
307 new = V_tcp_map_entries_limit;
308 error = sysctl_handle_int(oidp, &new, 0, req);
309 if (error == 0 && req->newptr) {
310 /* only allow "0" and value > minimum */
311 if (new > 0 && new < TCP_MIN_MAP_ENTRIES_LIMIT)
312 error = EINVAL;
313 else
314 V_tcp_map_entries_limit = new;
315 }
316 return (error);
317 }
318 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, map_limit,
319 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
320 &VNET_NAME(tcp_map_entries_limit), 0,
321 &sysctl_net_inet_tcp_map_limit_check, "IU",
322 "Total sendmap entries limit");
323
324 VNET_DEFINE(uint32_t, tcp_map_split_limit) = 0; /* unlimited */
325 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, split_limit, CTLFLAG_VNET | CTLFLAG_RW,
326 &VNET_NAME(tcp_map_split_limit), 0,
327 "Total sendmap split entries limit");
328
329 #ifdef TCP_HHOOK
330 VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
331 #endif
332
333 #define TS_OFFSET_SECRET_LENGTH SIPHASH_KEY_LENGTH
334 VNET_DEFINE_STATIC(u_char, ts_offset_secret[TS_OFFSET_SECRET_LENGTH]);
335 #define V_ts_offset_secret VNET(ts_offset_secret)
336
337 static int tcp_default_fb_init(struct tcpcb *tp, void **ptr);
338 static void tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged);
339 static int tcp_default_handoff_ok(struct tcpcb *tp);
340 static struct inpcb *tcp_notify(struct inpcb *, int);
341 static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
342 static struct inpcb *tcp_mtudisc(struct inpcb *, int);
343 static struct inpcb *tcp_drop_syn_sent(struct inpcb *, int);
344 static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
345 const void *ip4hdr, const void *ip6hdr);
346 static void tcp_default_switch_failed(struct tcpcb *tp);
347 static ipproto_ctlinput_t tcp_ctlinput;
348 static udp_tun_icmp_t tcp_ctlinput_viaudp;
349
350 static struct tcp_function_block tcp_def_funcblk = {
351 .tfb_tcp_block_name = "freebsd",
352 .tfb_tcp_output = tcp_default_output,
353 .tfb_tcp_do_segment = tcp_do_segment,
354 .tfb_tcp_ctloutput = tcp_default_ctloutput,
355 .tfb_tcp_handoff_ok = tcp_default_handoff_ok,
356 .tfb_tcp_fb_init = tcp_default_fb_init,
357 .tfb_tcp_fb_fini = tcp_default_fb_fini,
358 .tfb_switch_failed = tcp_default_switch_failed,
359 .tfb_flags = TCP_FUNC_DEFAULT_OK,
360 };
361
362 static int tcp_fb_cnt = 0;
363 struct tcp_funchead t_functions;
364 VNET_DEFINE_STATIC(struct tcp_function_block *, tcp_func_set_ptr) = &tcp_def_funcblk;
365 #define V_tcp_func_set_ptr VNET(tcp_func_set_ptr)
366
367 void
tcp_record_dsack(struct tcpcb * tp,tcp_seq start,tcp_seq end,int tlp)368 tcp_record_dsack(struct tcpcb *tp, tcp_seq start, tcp_seq end, int tlp)
369 {
370 TCPSTAT_INC(tcps_dsack_count);
371 tp->t_dsack_pack++;
372 if (tlp == 0) {
373 if (SEQ_GT(end, start)) {
374 tp->t_dsack_bytes += (end - start);
375 TCPSTAT_ADD(tcps_dsack_bytes, (end - start));
376 } else {
377 tp->t_dsack_tlp_bytes += (start - end);
378 TCPSTAT_ADD(tcps_dsack_bytes, (start - end));
379 }
380 } else {
381 if (SEQ_GT(end, start)) {
382 tp->t_dsack_bytes += (end - start);
383 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (end - start));
384 } else {
385 tp->t_dsack_tlp_bytes += (start - end);
386 TCPSTAT_ADD(tcps_dsack_tlp_bytes, (start - end));
387 }
388 }
389 }
390
391 static struct tcp_function_block *
find_tcp_functions_locked(struct tcp_function_set * fs)392 find_tcp_functions_locked(struct tcp_function_set *fs)
393 {
394 struct tcp_function *f;
395 struct tcp_function_block *blk = NULL;
396
397 rw_assert(&tcp_function_lock, RA_LOCKED);
398 TAILQ_FOREACH(f, &t_functions, tf_next) {
399 if (strcmp(f->tf_name, fs->function_set_name) == 0) {
400 blk = f->tf_fb;
401 break;
402 }
403 }
404 return (blk);
405 }
406
407 static struct tcp_function_block *
find_tcp_fb_locked(struct tcp_function_block * blk,struct tcp_function ** s)408 find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s)
409 {
410 struct tcp_function_block *rblk = NULL;
411 struct tcp_function *f;
412
413 rw_assert(&tcp_function_lock, RA_LOCKED);
414 TAILQ_FOREACH(f, &t_functions, tf_next) {
415 if (f->tf_fb == blk) {
416 rblk = blk;
417 if (s) {
418 *s = f;
419 }
420 break;
421 }
422 }
423 return (rblk);
424 }
425
426 struct tcp_function_block *
find_and_ref_tcp_functions(struct tcp_function_set * fs)427 find_and_ref_tcp_functions(struct tcp_function_set *fs)
428 {
429 struct tcp_function_block *blk;
430
431 rw_rlock(&tcp_function_lock);
432 blk = find_tcp_functions_locked(fs);
433 if (blk)
434 refcount_acquire(&blk->tfb_refcnt);
435 rw_runlock(&tcp_function_lock);
436 return (blk);
437 }
438
439 struct tcp_function_block *
find_and_ref_tcp_fb(struct tcp_function_block * blk)440 find_and_ref_tcp_fb(struct tcp_function_block *blk)
441 {
442 struct tcp_function_block *rblk;
443
444 rw_rlock(&tcp_function_lock);
445 rblk = find_tcp_fb_locked(blk, NULL);
446 if (rblk)
447 refcount_acquire(&rblk->tfb_refcnt);
448 rw_runlock(&tcp_function_lock);
449 return (rblk);
450 }
451
452 /* Find a matching alias for the given tcp_function_block. */
453 int
find_tcp_function_alias(struct tcp_function_block * blk,struct tcp_function_set * fs)454 find_tcp_function_alias(struct tcp_function_block *blk,
455 struct tcp_function_set *fs)
456 {
457 struct tcp_function *f;
458 int found;
459
460 found = 0;
461 rw_rlock(&tcp_function_lock);
462 TAILQ_FOREACH(f, &t_functions, tf_next) {
463 if ((f->tf_fb == blk) &&
464 (strncmp(f->tf_name, blk->tfb_tcp_block_name,
465 TCP_FUNCTION_NAME_LEN_MAX) != 0)) {
466 /* Matching function block with different name. */
467 strncpy(fs->function_set_name, f->tf_name,
468 TCP_FUNCTION_NAME_LEN_MAX);
469 found = 1;
470 break;
471 }
472 }
473 /* Null terminate the string appropriately. */
474 if (found) {
475 fs->function_set_name[TCP_FUNCTION_NAME_LEN_MAX - 1] = '\0';
476 } else {
477 fs->function_set_name[0] = '\0';
478 }
479 rw_runlock(&tcp_function_lock);
480 return (found);
481 }
482
483 static struct tcp_function_block *
find_and_ref_tcp_default_fb(void)484 find_and_ref_tcp_default_fb(void)
485 {
486 struct tcp_function_block *rblk;
487
488 rw_rlock(&tcp_function_lock);
489 rblk = V_tcp_func_set_ptr;
490 refcount_acquire(&rblk->tfb_refcnt);
491 rw_runlock(&tcp_function_lock);
492 return (rblk);
493 }
494
495 void
tcp_switch_back_to_default(struct tcpcb * tp)496 tcp_switch_back_to_default(struct tcpcb *tp)
497 {
498 struct tcp_function_block *tfb;
499 void *ptr = NULL;
500
501 KASSERT(tp->t_fb != &tcp_def_funcblk,
502 ("%s: called by the built-in default stack", __func__));
503
504 if (tp->t_fb->tfb_tcp_timer_stop_all != NULL)
505 tp->t_fb->tfb_tcp_timer_stop_all(tp);
506
507 /*
508 * Now, we'll find a new function block to use.
509 * Start by trying the current user-selected
510 * default, unless this stack is the user-selected
511 * default.
512 */
513 tfb = find_and_ref_tcp_default_fb();
514 if (tfb == tp->t_fb) {
515 refcount_release(&tfb->tfb_refcnt);
516 tfb = NULL;
517 }
518 /* Does the stack accept this connection? */
519 if (tfb != NULL && (*tfb->tfb_tcp_handoff_ok)(tp)) {
520 refcount_release(&tfb->tfb_refcnt);
521 tfb = NULL;
522 }
523 /* Try to use that stack. */
524 if (tfb != NULL) {
525 /* Initialize the new stack. If it succeeds, we are done. */
526 if (tfb->tfb_tcp_fb_init == NULL ||
527 (*tfb->tfb_tcp_fb_init)(tp, &ptr) == 0) {
528 /* Release the old stack */
529 if (tp->t_fb->tfb_tcp_fb_fini != NULL)
530 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0);
531 refcount_release(&tp->t_fb->tfb_refcnt);
532 /* Now set in all the pointers */
533 tp->t_fb = tfb;
534 tp->t_fb_ptr = ptr;
535 return;
536 }
537 /*
538 * Initialization failed. Release the reference count on
539 * the looked up default stack.
540 */
541 refcount_release(&tfb->tfb_refcnt);
542 }
543
544 /*
545 * If that wasn't feasible, use the built-in default
546 * stack which is not allowed to reject anyone.
547 */
548 tfb = find_and_ref_tcp_fb(&tcp_def_funcblk);
549 if (tfb == NULL) {
550 /* there always should be a default */
551 panic("Can't refer to tcp_def_funcblk");
552 }
553 if ((*tfb->tfb_tcp_handoff_ok)(tp)) {
554 /* The default stack cannot say no */
555 panic("Default stack rejects a new session?");
556 }
557 if (tfb->tfb_tcp_fb_init != NULL &&
558 (*tfb->tfb_tcp_fb_init)(tp, &ptr)) {
559 /* The default stack cannot fail */
560 panic("Default stack initialization failed");
561 }
562 /* Now release the old stack */
563 if (tp->t_fb->tfb_tcp_fb_fini != NULL)
564 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 0);
565 refcount_release(&tp->t_fb->tfb_refcnt);
566 /* And set in the pointers to the new */
567 tp->t_fb = tfb;
568 tp->t_fb_ptr = ptr;
569 }
570
571 static bool
tcp_recv_udp_tunneled_packet(struct mbuf * m,int off,struct inpcb * inp,const struct sockaddr * sa,void * ctx)572 tcp_recv_udp_tunneled_packet(struct mbuf *m, int off, struct inpcb *inp,
573 const struct sockaddr *sa, void *ctx)
574 {
575 struct ip *iph;
576 #ifdef INET6
577 struct ip6_hdr *ip6;
578 #endif
579 struct udphdr *uh;
580 struct tcphdr *th;
581 int thlen;
582 uint16_t port;
583
584 TCPSTAT_INC(tcps_tunneled_pkts);
585 if ((m->m_flags & M_PKTHDR) == 0) {
586 /* Can't handle one that is not a pkt hdr */
587 TCPSTAT_INC(tcps_tunneled_errs);
588 goto out;
589 }
590 thlen = sizeof(struct tcphdr);
591 if (m->m_len < off + sizeof(struct udphdr) + thlen &&
592 (m = m_pullup(m, off + sizeof(struct udphdr) + thlen)) == NULL) {
593 TCPSTAT_INC(tcps_tunneled_errs);
594 goto out;
595 }
596 iph = mtod(m, struct ip *);
597 uh = (struct udphdr *)((caddr_t)iph + off);
598 th = (struct tcphdr *)(uh + 1);
599 thlen = th->th_off << 2;
600 if (m->m_len < off + sizeof(struct udphdr) + thlen) {
601 m = m_pullup(m, off + sizeof(struct udphdr) + thlen);
602 if (m == NULL) {
603 TCPSTAT_INC(tcps_tunneled_errs);
604 goto out;
605 } else {
606 iph = mtod(m, struct ip *);
607 uh = (struct udphdr *)((caddr_t)iph + off);
608 th = (struct tcphdr *)(uh + 1);
609 }
610 }
611 m->m_pkthdr.tcp_tun_port = port = uh->uh_sport;
612 bcopy(th, uh, m->m_len - off);
613 m->m_len -= sizeof(struct udphdr);
614 m->m_pkthdr.len -= sizeof(struct udphdr);
615 /*
616 * We use the same algorithm for
617 * both UDP and TCP for c-sum. So
618 * the code in tcp_input will skip
619 * the checksum. So we do nothing
620 * with the flag (m->m_pkthdr.csum_flags).
621 */
622 switch (iph->ip_v) {
623 #ifdef INET
624 case IPVERSION:
625 iph->ip_len = htons(ntohs(iph->ip_len) - sizeof(struct udphdr));
626 tcp_input_with_port(&m, &off, IPPROTO_TCP, port);
627 break;
628 #endif
629 #ifdef INET6
630 case IPV6_VERSION >> 4:
631 ip6 = mtod(m, struct ip6_hdr *);
632 ip6->ip6_plen = htons(ntohs(ip6->ip6_plen) - sizeof(struct udphdr));
633 tcp6_input_with_port(&m, &off, IPPROTO_TCP, port);
634 break;
635 #endif
636 default:
637 goto out;
638 break;
639 }
640 return (true);
641 out:
642 m_freem(m);
643
644 return (true);
645 }
646
647 static int
sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)648 sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)
649 {
650 int error = ENOENT;
651 struct tcp_function_set fs;
652 struct tcp_function_block *blk;
653
654 memset(&fs, 0, sizeof(fs));
655 rw_rlock(&tcp_function_lock);
656 blk = find_tcp_fb_locked(V_tcp_func_set_ptr, NULL);
657 if (blk) {
658 /* Found him */
659 strcpy(fs.function_set_name, blk->tfb_tcp_block_name);
660 fs.pcbcnt = blk->tfb_refcnt;
661 }
662 rw_runlock(&tcp_function_lock);
663 error = sysctl_handle_string(oidp, fs.function_set_name,
664 sizeof(fs.function_set_name), req);
665
666 /* Check for error or no change */
667 if (error != 0 || req->newptr == NULL)
668 return (error);
669
670 rw_wlock(&tcp_function_lock);
671 blk = find_tcp_functions_locked(&fs);
672 if ((blk == NULL) ||
673 (blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) {
674 error = ENOENT;
675 goto done;
676 }
677 if ((blk->tfb_flags & TCP_FUNC_DEFAULT_OK) == 0) {
678 error = EINVAL;
679 goto done;
680 }
681 V_tcp_func_set_ptr = blk;
682 done:
683 rw_wunlock(&tcp_function_lock);
684 return (error);
685 }
686
687 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default,
688 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
689 NULL, 0, sysctl_net_inet_default_tcp_functions, "A",
690 "Set/get the default TCP functions");
691
692 static int
sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS)693 sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS)
694 {
695 int error, cnt, linesz;
696 struct tcp_function *f;
697 char *buffer, *cp;
698 size_t bufsz, outsz;
699 bool alias;
700
701 cnt = 0;
702 rw_rlock(&tcp_function_lock);
703 TAILQ_FOREACH(f, &t_functions, tf_next) {
704 cnt++;
705 }
706 rw_runlock(&tcp_function_lock);
707
708 bufsz = (cnt+2) * ((TCP_FUNCTION_NAME_LEN_MAX * 2) + 13) + 1;
709 buffer = malloc(bufsz, M_TEMP, M_WAITOK);
710
711 error = 0;
712 cp = buffer;
713
714 linesz = snprintf(cp, bufsz, "\n%-32s%c %-32s %s\n", "Stack", 'D',
715 "Alias", "PCB count");
716 cp += linesz;
717 bufsz -= linesz;
718 outsz = linesz;
719
720 rw_rlock(&tcp_function_lock);
721 TAILQ_FOREACH(f, &t_functions, tf_next) {
722 alias = (f->tf_name != f->tf_fb->tfb_tcp_block_name);
723 linesz = snprintf(cp, bufsz, "%-32s%c %-32s %u\n",
724 f->tf_fb->tfb_tcp_block_name,
725 (f->tf_fb == V_tcp_func_set_ptr) ? '*' : ' ',
726 alias ? f->tf_name : "-",
727 f->tf_fb->tfb_refcnt);
728 if (linesz >= bufsz) {
729 error = EOVERFLOW;
730 break;
731 }
732 cp += linesz;
733 bufsz -= linesz;
734 outsz += linesz;
735 }
736 rw_runlock(&tcp_function_lock);
737 if (error == 0)
738 error = sysctl_handle_string(oidp, buffer, outsz + 1, req);
739 free(buffer, M_TEMP);
740 return (error);
741 }
742
743 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available,
744 CTLFLAG_VNET | CTLTYPE_STRING | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
745 NULL, 0, sysctl_net_inet_list_available, "A",
746 "list available TCP Function sets");
747
748 VNET_DEFINE(int, tcp_udp_tunneling_port) = TCP_TUNNELING_PORT_DEFAULT;
749
750 #ifdef INET
751 VNET_DEFINE(struct socket *, udp4_tun_socket) = NULL;
752 #define V_udp4_tun_socket VNET(udp4_tun_socket)
753 #endif
754 #ifdef INET6
755 VNET_DEFINE(struct socket *, udp6_tun_socket) = NULL;
756 #define V_udp6_tun_socket VNET(udp6_tun_socket)
757 #endif
758
759 static struct sx tcpoudp_lock;
760
761 static void
tcp_over_udp_stop(void)762 tcp_over_udp_stop(void)
763 {
764
765 sx_assert(&tcpoudp_lock, SA_XLOCKED);
766
767 #ifdef INET
768 if (V_udp4_tun_socket != NULL) {
769 soclose(V_udp4_tun_socket);
770 V_udp4_tun_socket = NULL;
771 }
772 #endif
773 #ifdef INET6
774 if (V_udp6_tun_socket != NULL) {
775 soclose(V_udp6_tun_socket);
776 V_udp6_tun_socket = NULL;
777 }
778 #endif
779 }
780
781 static int
tcp_over_udp_start(void)782 tcp_over_udp_start(void)
783 {
784 uint16_t port;
785 int ret;
786 #ifdef INET
787 struct sockaddr_in sin;
788 #endif
789 #ifdef INET6
790 struct sockaddr_in6 sin6;
791 #endif
792
793 sx_assert(&tcpoudp_lock, SA_XLOCKED);
794
795 port = V_tcp_udp_tunneling_port;
796 if (ntohs(port) == 0) {
797 /* Must have a port set */
798 return (EINVAL);
799 }
800 #ifdef INET
801 if (V_udp4_tun_socket != NULL) {
802 /* Already running -- must stop first */
803 return (EALREADY);
804 }
805 #endif
806 #ifdef INET6
807 if (V_udp6_tun_socket != NULL) {
808 /* Already running -- must stop first */
809 return (EALREADY);
810 }
811 #endif
812 #ifdef INET
813 if ((ret = socreate(PF_INET, &V_udp4_tun_socket,
814 SOCK_DGRAM, IPPROTO_UDP,
815 curthread->td_ucred, curthread))) {
816 tcp_over_udp_stop();
817 return (ret);
818 }
819 /* Call the special UDP hook. */
820 if ((ret = udp_set_kernel_tunneling(V_udp4_tun_socket,
821 tcp_recv_udp_tunneled_packet,
822 tcp_ctlinput_viaudp,
823 NULL))) {
824 tcp_over_udp_stop();
825 return (ret);
826 }
827 /* Ok, we have a socket, bind it to the port. */
828 memset(&sin, 0, sizeof(struct sockaddr_in));
829 sin.sin_len = sizeof(struct sockaddr_in);
830 sin.sin_family = AF_INET;
831 sin.sin_port = htons(port);
832 if ((ret = sobind(V_udp4_tun_socket,
833 (struct sockaddr *)&sin, curthread))) {
834 tcp_over_udp_stop();
835 return (ret);
836 }
837 #endif
838 #ifdef INET6
839 if ((ret = socreate(PF_INET6, &V_udp6_tun_socket,
840 SOCK_DGRAM, IPPROTO_UDP,
841 curthread->td_ucred, curthread))) {
842 tcp_over_udp_stop();
843 return (ret);
844 }
845 /* Call the special UDP hook. */
846 if ((ret = udp_set_kernel_tunneling(V_udp6_tun_socket,
847 tcp_recv_udp_tunneled_packet,
848 tcp6_ctlinput_viaudp,
849 NULL))) {
850 tcp_over_udp_stop();
851 return (ret);
852 }
853 /* Ok, we have a socket, bind it to the port. */
854 memset(&sin6, 0, sizeof(struct sockaddr_in6));
855 sin6.sin6_len = sizeof(struct sockaddr_in6);
856 sin6.sin6_family = AF_INET6;
857 sin6.sin6_port = htons(port);
858 if ((ret = sobind(V_udp6_tun_socket,
859 (struct sockaddr *)&sin6, curthread))) {
860 tcp_over_udp_stop();
861 return (ret);
862 }
863 #endif
864 return (0);
865 }
866
867 static int
sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS)868 sysctl_net_inet_tcp_udp_tunneling_port_check(SYSCTL_HANDLER_ARGS)
869 {
870 int error;
871 uint32_t old, new;
872
873 old = V_tcp_udp_tunneling_port;
874 new = old;
875 error = sysctl_handle_int(oidp, &new, 0, req);
876 if ((error == 0) &&
877 (req->newptr != NULL)) {
878 if ((new < TCP_TUNNELING_PORT_MIN) ||
879 (new > TCP_TUNNELING_PORT_MAX)) {
880 error = EINVAL;
881 } else {
882 sx_xlock(&tcpoudp_lock);
883 V_tcp_udp_tunneling_port = new;
884 if (old != 0) {
885 tcp_over_udp_stop();
886 }
887 if (new != 0) {
888 error = tcp_over_udp_start();
889 if (error != 0) {
890 V_tcp_udp_tunneling_port = 0;
891 }
892 }
893 sx_xunlock(&tcpoudp_lock);
894 }
895 }
896 return (error);
897 }
898
899 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_port,
900 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
901 &VNET_NAME(tcp_udp_tunneling_port),
902 0, &sysctl_net_inet_tcp_udp_tunneling_port_check, "IU",
903 "Tunneling port for tcp over udp");
904
905 VNET_DEFINE(int, tcp_udp_tunneling_overhead) = TCP_TUNNELING_OVERHEAD_DEFAULT;
906
907 static int
sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS)908 sysctl_net_inet_tcp_udp_tunneling_overhead_check(SYSCTL_HANDLER_ARGS)
909 {
910 int error, new;
911
912 new = V_tcp_udp_tunneling_overhead;
913 error = sysctl_handle_int(oidp, &new, 0, req);
914 if (error == 0 && req->newptr) {
915 if ((new < TCP_TUNNELING_OVERHEAD_MIN) ||
916 (new > TCP_TUNNELING_OVERHEAD_MAX))
917 error = EINVAL;
918 else
919 V_tcp_udp_tunneling_overhead = new;
920 }
921 return (error);
922 }
923
924 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, udp_tunneling_overhead,
925 CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE,
926 &VNET_NAME(tcp_udp_tunneling_overhead),
927 0, &sysctl_net_inet_tcp_udp_tunneling_overhead_check, "IU",
928 "MSS reduction when using tcp over udp");
929
930 /*
931 * Exports one (struct tcp_function_info) for each alias/name.
932 */
933 static int
sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS)934 sysctl_net_inet_list_func_info(SYSCTL_HANDLER_ARGS)
935 {
936 int cnt, error;
937 struct tcp_function *f;
938 struct tcp_function_info tfi;
939
940 /*
941 * We don't allow writes.
942 */
943 if (req->newptr != NULL)
944 return (EINVAL);
945
946 /*
947 * Wire the old buffer so we can directly copy the functions to
948 * user space without dropping the lock.
949 */
950 if (req->oldptr != NULL) {
951 error = sysctl_wire_old_buffer(req, 0);
952 if (error)
953 return (error);
954 }
955
956 /*
957 * Walk the list and copy out matching entries. If INVARIANTS
958 * is compiled in, also walk the list to verify the length of
959 * the list matches what we have recorded.
960 */
961 rw_rlock(&tcp_function_lock);
962
963 cnt = 0;
964 #ifndef INVARIANTS
965 if (req->oldptr == NULL) {
966 cnt = tcp_fb_cnt;
967 goto skip_loop;
968 }
969 #endif
970 TAILQ_FOREACH(f, &t_functions, tf_next) {
971 #ifdef INVARIANTS
972 cnt++;
973 #endif
974 if (req->oldptr != NULL) {
975 bzero(&tfi, sizeof(tfi));
976 tfi.tfi_refcnt = f->tf_fb->tfb_refcnt;
977 tfi.tfi_id = f->tf_fb->tfb_id;
978 (void)strlcpy(tfi.tfi_alias, f->tf_name,
979 sizeof(tfi.tfi_alias));
980 (void)strlcpy(tfi.tfi_name,
981 f->tf_fb->tfb_tcp_block_name, sizeof(tfi.tfi_name));
982 error = SYSCTL_OUT(req, &tfi, sizeof(tfi));
983 /*
984 * Don't stop on error, as that is the
985 * mechanism we use to accumulate length
986 * information if the buffer was too short.
987 */
988 }
989 }
990 KASSERT(cnt == tcp_fb_cnt,
991 ("%s: cnt (%d) != tcp_fb_cnt (%d)", __func__, cnt, tcp_fb_cnt));
992 #ifndef INVARIANTS
993 skip_loop:
994 #endif
995 rw_runlock(&tcp_function_lock);
996 if (req->oldptr == NULL)
997 error = SYSCTL_OUT(req, NULL,
998 (cnt + 1) * sizeof(struct tcp_function_info));
999
1000 return (error);
1001 }
1002
1003 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, function_info,
1004 CTLTYPE_OPAQUE | CTLFLAG_SKIP | CTLFLAG_RD | CTLFLAG_MPSAFE,
1005 NULL, 0, sysctl_net_inet_list_func_info, "S,tcp_function_info",
1006 "List TCP function block name-to-ID mappings");
1007
1008 /*
1009 * tfb_tcp_handoff_ok() function for the default stack.
1010 * Note that we'll basically try to take all comers.
1011 */
1012 static int
tcp_default_handoff_ok(struct tcpcb * tp)1013 tcp_default_handoff_ok(struct tcpcb *tp)
1014 {
1015
1016 return (0);
1017 }
1018
1019 /*
1020 * tfb_tcp_fb_init() function for the default stack.
1021 *
1022 * This handles making sure we have appropriate timers set if you are
1023 * transitioning a socket that has some amount of setup done.
1024 *
1025 * The init() fuction from the default can *never* return non-zero i.e.
1026 * it is required to always succeed since it is the stack of last resort!
1027 */
1028 static int
tcp_default_fb_init(struct tcpcb * tp,void ** ptr)1029 tcp_default_fb_init(struct tcpcb *tp, void **ptr)
1030 {
1031 struct socket *so = tptosocket(tp);
1032 int rexmt;
1033
1034 INP_WLOCK_ASSERT(tptoinpcb(tp));
1035 /* We don't use the pointer */
1036 *ptr = NULL;
1037
1038 KASSERT(tp->t_state < TCPS_TIME_WAIT,
1039 ("%s: connection %p in unexpected state %d", __func__, tp,
1040 tp->t_state));
1041
1042 /* Make sure we get no interesting mbuf queuing behavior */
1043 /* All mbuf queue/ack compress flags should be off */
1044 tcp_lro_features_off(tp);
1045
1046 /* Cancel the GP measurement in progress */
1047 tp->t_flags &= ~TF_GPUTINPROG;
1048 /* Validate the timers are not in usec, if they are convert */
1049 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
1050 if ((tp->t_state == TCPS_SYN_SENT) ||
1051 (tp->t_state == TCPS_SYN_RECEIVED))
1052 rexmt = tcp_rexmit_initial * tcp_backoff[tp->t_rxtshift];
1053 else
1054 rexmt = TCP_REXMTVAL(tp) * tcp_backoff[tp->t_rxtshift];
1055 if (tp->t_rxtshift == 0)
1056 tp->t_rxtcur = rexmt;
1057 else
1058 TCPT_RANGESET(tp->t_rxtcur, rexmt, tp->t_rttmin, TCPTV_REXMTMAX);
1059
1060 /*
1061 * Nothing to do for ESTABLISHED or LISTEN states. And, we don't
1062 * know what to do for unexpected states (which includes TIME_WAIT).
1063 */
1064 if (tp->t_state <= TCPS_LISTEN || tp->t_state >= TCPS_TIME_WAIT)
1065 return (0);
1066
1067 /*
1068 * Make sure some kind of transmission timer is set if there is
1069 * outstanding data.
1070 */
1071 if ((!TCPS_HAVEESTABLISHED(tp->t_state) || sbavail(&so->so_snd) ||
1072 tp->snd_una != tp->snd_max) && !(tcp_timer_active(tp, TT_REXMT) ||
1073 tcp_timer_active(tp, TT_PERSIST))) {
1074 /*
1075 * If the session has established and it looks like it should
1076 * be in the persist state, set the persist timer. Otherwise,
1077 * set the retransmit timer.
1078 */
1079 if (TCPS_HAVEESTABLISHED(tp->t_state) && tp->snd_wnd == 0 &&
1080 (int32_t)(tp->snd_nxt - tp->snd_una) <
1081 (int32_t)sbavail(&so->so_snd))
1082 tcp_setpersist(tp);
1083 else
1084 tcp_timer_activate(tp, TT_REXMT, TP_RXTCUR(tp));
1085 }
1086
1087 /* All non-embryonic sessions get a keepalive timer. */
1088 if (!tcp_timer_active(tp, TT_KEEP))
1089 tcp_timer_activate(tp, TT_KEEP,
1090 TCPS_HAVEESTABLISHED(tp->t_state) ? TP_KEEPIDLE(tp) :
1091 TP_KEEPINIT(tp));
1092
1093 /*
1094 * Make sure critical variables are initialized
1095 * if transitioning while in Recovery.
1096 */
1097 if IN_FASTRECOVERY(tp->t_flags) {
1098 if (tp->sackhint.recover_fs == 0)
1099 tp->sackhint.recover_fs = max(1,
1100 tp->snd_nxt - tp->snd_una);
1101 }
1102
1103 return (0);
1104 }
1105
1106 /*
1107 * tfb_tcp_fb_fini() function for the default stack.
1108 *
1109 * This changes state as necessary (or prudent) to prepare for another stack
1110 * to assume responsibility for the connection.
1111 */
1112 static void
tcp_default_fb_fini(struct tcpcb * tp,int tcb_is_purged)1113 tcp_default_fb_fini(struct tcpcb *tp, int tcb_is_purged)
1114 {
1115
1116 INP_WLOCK_ASSERT(tptoinpcb(tp));
1117
1118 #ifdef TCP_BLACKBOX
1119 tcp_log_flowend(tp);
1120 #endif
1121 tp->t_acktime = 0;
1122 return;
1123 }
1124
1125 MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
1126 MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory");
1127
1128 static struct mtx isn_mtx;
1129
1130 #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
1131 #define ISN_LOCK() mtx_lock(&isn_mtx)
1132 #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
1133
1134 INPCBSTORAGE_DEFINE(tcpcbstor, tcpcb, "tcpinp", "tcp_inpcb", "tcp", "tcphash");
1135
1136 /*
1137 * Take a value and get the next power of 2 that doesn't overflow.
1138 * Used to size the tcp_inpcb hash buckets.
1139 */
1140 static int
maketcp_hashsize(int size)1141 maketcp_hashsize(int size)
1142 {
1143 int hashsize;
1144
1145 /*
1146 * auto tune.
1147 * get the next power of 2 higher than maxsockets.
1148 */
1149 hashsize = 1 << fls(size);
1150 /* catch overflow, and just go one power of 2 smaller */
1151 if (hashsize < size) {
1152 hashsize = 1 << (fls(size) - 1);
1153 }
1154 return (hashsize);
1155 }
1156
1157 static volatile int next_tcp_stack_id = 1;
1158
1159 /*
1160 * Register a TCP function block with the name provided in the names
1161 * array. (Note that this function does NOT automatically register
1162 * blk->tfb_tcp_block_name as a stack name. Therefore, you should
1163 * explicitly include blk->tfb_tcp_block_name in the list of names if
1164 * you wish to register the stack with that name.)
1165 *
1166 * Either all name registrations will succeed or all will fail. If
1167 * a name registration fails, the function will update the num_names
1168 * argument to point to the array index of the name that encountered
1169 * the failure.
1170 *
1171 * Returns 0 on success, or an error code on failure.
1172 */
1173 int
register_tcp_functions_as_names(struct tcp_function_block * blk,int wait,const char * names[],int * num_names)1174 register_tcp_functions_as_names(struct tcp_function_block *blk, int wait,
1175 const char *names[], int *num_names)
1176 {
1177 struct tcp_function *f[TCP_FUNCTION_NAME_NUM_MAX];
1178 struct tcp_function_set fs;
1179 int error, i, num_registered;
1180
1181 KASSERT(names != NULL, ("%s: Called with NULL name list", __func__));
1182 KASSERT(*num_names > 0,
1183 ("%s: Called with non-positive length of name list", __func__));
1184 KASSERT(rw_initialized(&tcp_function_lock),
1185 ("%s: called too early", __func__));
1186
1187 if (*num_names > TCP_FUNCTION_NAME_NUM_MAX) {
1188 /* Too many names. */
1189 *num_names = 0;
1190 return (E2BIG);
1191 }
1192 if ((blk->tfb_tcp_output == NULL) ||
1193 (blk->tfb_tcp_do_segment == NULL) ||
1194 (blk->tfb_tcp_ctloutput == NULL) ||
1195 (blk->tfb_tcp_handoff_ok == NULL) ||
1196 (strlen(blk->tfb_tcp_block_name) == 0)) {
1197 /* These functions are required and a name is needed. */
1198 *num_names = 0;
1199 return (EINVAL);
1200 }
1201
1202 for (i = 0; i < *num_names; i++) {
1203 f[i] = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait);
1204 if (f[i] == NULL) {
1205 while (--i >= 0)
1206 free(f[i], M_TCPFUNCTIONS);
1207 *num_names = 0;
1208 return (ENOMEM);
1209 }
1210 }
1211
1212 num_registered = 0;
1213 rw_wlock(&tcp_function_lock);
1214 if (find_tcp_fb_locked(blk, NULL) != NULL) {
1215 /* A TCP function block can only be registered once. */
1216 error = EALREADY;
1217 goto cleanup;
1218 }
1219 if (blk->tfb_flags & TCP_FUNC_BEING_REMOVED) {
1220 error = EINVAL;
1221 goto cleanup;
1222 }
1223 refcount_init(&blk->tfb_refcnt, 0);
1224 blk->tfb_id = atomic_fetchadd_int(&next_tcp_stack_id, 1);
1225 for (i = 0; i < *num_names; i++) {
1226 (void)strlcpy(fs.function_set_name, names[i],
1227 sizeof(fs.function_set_name));
1228 if (find_tcp_functions_locked(&fs) != NULL) {
1229 /* Duplicate name space not allowed */
1230 error = EALREADY;
1231 goto cleanup;
1232 }
1233 f[i]->tf_fb = blk;
1234 (void)strlcpy(f[i]->tf_name, names[i], sizeof(f[i]->tf_name));
1235 TAILQ_INSERT_TAIL(&t_functions, f[i], tf_next);
1236 tcp_fb_cnt++;
1237 num_registered++;
1238 }
1239 rw_wunlock(&tcp_function_lock);
1240 return (0);
1241
1242 cleanup:
1243 /* Remove the entries just added. */
1244 for (i = 0; i < *num_names; i++) {
1245 if (i < num_registered) {
1246 TAILQ_REMOVE(&t_functions, f[i], tf_next);
1247 tcp_fb_cnt--;
1248 }
1249 f[i]->tf_fb = NULL;
1250 free(f[i], M_TCPFUNCTIONS);
1251 }
1252 rw_wunlock(&tcp_function_lock);
1253 *num_names = num_registered;
1254 return (error);
1255 }
1256
1257 /*
1258 * Register a TCP function block using the name provided in the name
1259 * argument.
1260 *
1261 * Returns 0 on success, or an error code on failure.
1262 */
1263 int
register_tcp_functions_as_name(struct tcp_function_block * blk,const char * name,int wait)1264 register_tcp_functions_as_name(struct tcp_function_block *blk, const char *name,
1265 int wait)
1266 {
1267 const char *name_list[1];
1268 int num_names, rv;
1269
1270 num_names = 1;
1271 if (name != NULL)
1272 name_list[0] = name;
1273 else
1274 name_list[0] = blk->tfb_tcp_block_name;
1275 rv = register_tcp_functions_as_names(blk, wait, name_list, &num_names);
1276 return (rv);
1277 }
1278
1279 /*
1280 * Register a TCP function block using the name defined in
1281 * blk->tfb_tcp_block_name.
1282 *
1283 * Returns 0 on success, or an error code on failure.
1284 */
1285 int
register_tcp_functions(struct tcp_function_block * blk,int wait)1286 register_tcp_functions(struct tcp_function_block *blk, int wait)
1287 {
1288
1289 return (register_tcp_functions_as_name(blk, NULL, wait));
1290 }
1291
1292 /*
1293 * Deregister all names associated with a function block. This
1294 * functionally removes the function block from use within the system.
1295 *
1296 * When called with a true quiesce argument, mark the function block
1297 * as being removed so no more stacks will use it and determine
1298 * whether the removal would succeed.
1299 *
1300 * When called with a false quiesce argument, actually attempt the
1301 * removal.
1302 *
1303 * When called with a force argument, attempt to switch all TCBs to
1304 * use the default stack instead of returning EBUSY.
1305 *
1306 * Returns 0 on success (or if the removal would succeed), or an error
1307 * code on failure.
1308 */
1309 int
deregister_tcp_functions(struct tcp_function_block * blk,bool quiesce,bool force)1310 deregister_tcp_functions(struct tcp_function_block *blk, bool quiesce,
1311 bool force)
1312 {
1313 struct tcp_function *f;
1314 VNET_ITERATOR_DECL(vnet_iter);
1315
1316 if (blk == &tcp_def_funcblk) {
1317 /* You can't un-register the default */
1318 return (EPERM);
1319 }
1320 rw_wlock(&tcp_function_lock);
1321 VNET_LIST_RLOCK_NOSLEEP();
1322 VNET_FOREACH(vnet_iter) {
1323 CURVNET_SET(vnet_iter);
1324 if (blk == V_tcp_func_set_ptr) {
1325 /* You can't free the current default in some vnet. */
1326 CURVNET_RESTORE();
1327 VNET_LIST_RUNLOCK_NOSLEEP();
1328 rw_wunlock(&tcp_function_lock);
1329 return (EBUSY);
1330 }
1331 CURVNET_RESTORE();
1332 }
1333 VNET_LIST_RUNLOCK_NOSLEEP();
1334 /* Mark the block so no more stacks can use it. */
1335 blk->tfb_flags |= TCP_FUNC_BEING_REMOVED;
1336 /*
1337 * If TCBs are still attached to the stack, attempt to switch them
1338 * to the default stack.
1339 */
1340 if (force && blk->tfb_refcnt) {
1341 struct inpcb *inp;
1342 struct tcpcb *tp;
1343 VNET_ITERATOR_DECL(vnet_iter);
1344
1345 rw_wunlock(&tcp_function_lock);
1346
1347 VNET_LIST_RLOCK();
1348 VNET_FOREACH(vnet_iter) {
1349 CURVNET_SET(vnet_iter);
1350 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo,
1351 INPLOOKUP_WLOCKPCB);
1352
1353 while ((inp = inp_next(&inpi)) != NULL) {
1354 tp = intotcpcb(inp);
1355 if (tp == NULL || tp->t_fb != blk)
1356 continue;
1357 tcp_switch_back_to_default(tp);
1358 }
1359 CURVNET_RESTORE();
1360 }
1361 VNET_LIST_RUNLOCK();
1362
1363 rw_wlock(&tcp_function_lock);
1364 }
1365 if (blk->tfb_refcnt) {
1366 /* TCBs still attached. */
1367 rw_wunlock(&tcp_function_lock);
1368 return (EBUSY);
1369 }
1370 if (quiesce) {
1371 /* Skip removal. */
1372 rw_wunlock(&tcp_function_lock);
1373 return (0);
1374 }
1375 /* Remove any function names that map to this function block. */
1376 while (find_tcp_fb_locked(blk, &f) != NULL) {
1377 TAILQ_REMOVE(&t_functions, f, tf_next);
1378 tcp_fb_cnt--;
1379 f->tf_fb = NULL;
1380 free(f, M_TCPFUNCTIONS);
1381 }
1382 rw_wunlock(&tcp_function_lock);
1383 return (0);
1384 }
1385
1386 static void
tcp_drain(void)1387 tcp_drain(void)
1388 {
1389 struct epoch_tracker et;
1390 VNET_ITERATOR_DECL(vnet_iter);
1391
1392 if (!do_tcpdrain)
1393 return;
1394
1395 NET_EPOCH_ENTER(et);
1396 VNET_LIST_RLOCK_NOSLEEP();
1397 VNET_FOREACH(vnet_iter) {
1398 CURVNET_SET(vnet_iter);
1399 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo,
1400 INPLOOKUP_WLOCKPCB);
1401 struct inpcb *inpb;
1402 struct tcpcb *tcpb;
1403
1404 /*
1405 * Walk the tcpbs, if existing, and flush the reassembly queue,
1406 * if there is one...
1407 * XXX: The "Net/3" implementation doesn't imply that the TCP
1408 * reassembly queue should be flushed, but in a situation
1409 * where we're really low on mbufs, this is potentially
1410 * useful.
1411 */
1412 while ((inpb = inp_next(&inpi)) != NULL) {
1413 if ((tcpb = intotcpcb(inpb)) != NULL) {
1414 tcp_reass_flush(tcpb);
1415 tcp_clean_sackreport(tcpb);
1416 #ifdef TCP_BLACKBOX
1417 tcp_log_drain(tcpb);
1418 #endif
1419 #ifdef TCPPCAP
1420 if (tcp_pcap_aggressive_free) {
1421 /* Free the TCP PCAP queues. */
1422 tcp_pcap_drain(&(tcpb->t_inpkts));
1423 tcp_pcap_drain(&(tcpb->t_outpkts));
1424 }
1425 #endif
1426 }
1427 }
1428 CURVNET_RESTORE();
1429 }
1430 VNET_LIST_RUNLOCK_NOSLEEP();
1431 NET_EPOCH_EXIT(et);
1432 }
1433
1434 static void
tcp_vnet_init(void * arg __unused)1435 tcp_vnet_init(void *arg __unused)
1436 {
1437
1438 #ifdef TCP_HHOOK
1439 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
1440 &V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
1441 printf("%s: WARNING: unable to register helper hook\n", __func__);
1442 if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
1443 &V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
1444 printf("%s: WARNING: unable to register helper hook\n", __func__);
1445 #endif
1446 #ifdef STATS
1447 if (tcp_stats_init())
1448 printf("%s: WARNING: unable to initialise TCP stats\n",
1449 __func__);
1450 #endif
1451 in_pcbinfo_init(&V_tcbinfo, &tcpcbstor, tcp_tcbhashsize,
1452 tcp_tcbhashsize);
1453
1454 syncache_init();
1455 tcp_hc_init();
1456
1457 TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
1458 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
1459 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1460
1461 tcp_fastopen_init();
1462
1463 COUNTER_ARRAY_ALLOC(V_tcps_states, TCP_NSTATES, M_WAITOK);
1464 VNET_PCPUSTAT_ALLOC(tcpstat, M_WAITOK);
1465
1466 V_tcp_msl = TCPTV_MSL;
1467 arc4rand(&V_ts_offset_secret, sizeof(V_ts_offset_secret), 0);
1468 }
1469 VNET_SYSINIT(tcp_vnet_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH,
1470 tcp_vnet_init, NULL);
1471
1472 static void
tcp_init(void * arg __unused)1473 tcp_init(void *arg __unused)
1474 {
1475 int hashsize;
1476
1477 tcp_reass_global_init();
1478
1479 /* XXX virtualize those below? */
1480 tcp_delacktime = TCPTV_DELACK;
1481 tcp_keepinit = TCPTV_KEEP_INIT;
1482 tcp_keepidle = TCPTV_KEEP_IDLE;
1483 tcp_keepintvl = TCPTV_KEEPINTVL;
1484 tcp_maxpersistidle = TCPTV_KEEP_IDLE;
1485 tcp_rexmit_initial = TCPTV_RTOBASE;
1486 if (tcp_rexmit_initial < 1)
1487 tcp_rexmit_initial = 1;
1488 tcp_rexmit_min = TCPTV_MIN;
1489 if (tcp_rexmit_min < 1)
1490 tcp_rexmit_min = 1;
1491 tcp_persmin = TCPTV_PERSMIN;
1492 tcp_persmax = TCPTV_PERSMAX;
1493 tcp_rexmit_slop = TCPTV_CPU_VAR;
1494 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
1495
1496 /* Setup the tcp function block list */
1497 TAILQ_INIT(&t_functions);
1498 rw_init(&tcp_function_lock, "tcp_func_lock");
1499 register_tcp_functions(&tcp_def_funcblk, M_WAITOK);
1500 sx_init(&tcpoudp_lock, "TCP over UDP configuration");
1501 #ifdef TCP_BLACKBOX
1502 /* Initialize the TCP logging data. */
1503 tcp_log_init();
1504 #endif
1505
1506 if (tcp_soreceive_stream) {
1507 #ifdef INET
1508 tcp_protosw.pr_soreceive = soreceive_stream;
1509 #endif
1510 #ifdef INET6
1511 tcp6_protosw.pr_soreceive = soreceive_stream;
1512 #endif /* INET6 */
1513 }
1514
1515 #ifdef INET6
1516 max_protohdr_grow(sizeof(struct ip6_hdr) + sizeof(struct tcphdr));
1517 #else /* INET6 */
1518 max_protohdr_grow(sizeof(struct tcpiphdr));
1519 #endif /* INET6 */
1520
1521 ISN_LOCK_INIT();
1522 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
1523 SHUTDOWN_PRI_DEFAULT);
1524 EVENTHANDLER_REGISTER(vm_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT);
1525 EVENTHANDLER_REGISTER(mbuf_lowmem, tcp_drain, NULL, LOWMEM_PRI_DEFAULT);
1526
1527 tcp_inp_lro_direct_queue = counter_u64_alloc(M_WAITOK);
1528 tcp_inp_lro_wokeup_queue = counter_u64_alloc(M_WAITOK);
1529 tcp_inp_lro_compressed = counter_u64_alloc(M_WAITOK);
1530 tcp_inp_lro_locks_taken = counter_u64_alloc(M_WAITOK);
1531 tcp_extra_mbuf = counter_u64_alloc(M_WAITOK);
1532 tcp_would_have_but = counter_u64_alloc(M_WAITOK);
1533 tcp_comp_total = counter_u64_alloc(M_WAITOK);
1534 tcp_uncomp_total = counter_u64_alloc(M_WAITOK);
1535 tcp_bad_csums = counter_u64_alloc(M_WAITOK);
1536 tcp_pacing_failures = counter_u64_alloc(M_WAITOK);
1537 tcp_dgp_failures = counter_u64_alloc(M_WAITOK);
1538 #ifdef TCPPCAP
1539 tcp_pcap_init();
1540 #endif
1541
1542 hashsize = tcp_tcbhashsize;
1543 if (hashsize == 0) {
1544 /*
1545 * Auto tune the hash size based on maxsockets.
1546 * A perfect hash would have a 1:1 mapping
1547 * (hashsize = maxsockets) however it's been
1548 * suggested that O(2) average is better.
1549 */
1550 hashsize = maketcp_hashsize(maxsockets / 4);
1551 /*
1552 * Our historical default is 512,
1553 * do not autotune lower than this.
1554 */
1555 if (hashsize < 512)
1556 hashsize = 512;
1557 if (bootverbose)
1558 printf("%s: %s auto tuned to %d\n", __func__,
1559 "net.inet.tcp.tcbhashsize", hashsize);
1560 }
1561 /*
1562 * We require a hashsize to be a power of two.
1563 * Previously if it was not a power of two we would just reset it
1564 * back to 512, which could be a nasty surprise if you did not notice
1565 * the error message.
1566 * Instead what we do is clip it to the closest power of two lower
1567 * than the specified hash value.
1568 */
1569 if (!powerof2(hashsize)) {
1570 int oldhashsize = hashsize;
1571
1572 hashsize = maketcp_hashsize(hashsize);
1573 /* prevent absurdly low value */
1574 if (hashsize < 16)
1575 hashsize = 16;
1576 printf("%s: WARNING: TCB hash size not a power of 2, "
1577 "clipped from %d to %d.\n", __func__, oldhashsize,
1578 hashsize);
1579 }
1580 tcp_tcbhashsize = hashsize;
1581
1582 #ifdef INET
1583 IPPROTO_REGISTER(IPPROTO_TCP, tcp_input, tcp_ctlinput);
1584 #endif
1585 #ifdef INET6
1586 IP6PROTO_REGISTER(IPPROTO_TCP, tcp6_input, tcp6_ctlinput);
1587 #endif
1588 }
1589 SYSINIT(tcp_init, SI_SUB_PROTO_DOMAIN, SI_ORDER_THIRD, tcp_init, NULL);
1590
1591 #ifdef VIMAGE
1592 static void
tcp_destroy(void * unused __unused)1593 tcp_destroy(void *unused __unused)
1594 {
1595 #ifdef TCP_HHOOK
1596 int error;
1597 #endif
1598
1599 tcp_hc_destroy();
1600 syncache_destroy();
1601 in_pcbinfo_destroy(&V_tcbinfo);
1602 /* tcp_discardcb() clears the sack_holes up. */
1603 uma_zdestroy(V_sack_hole_zone);
1604
1605 /*
1606 * Cannot free the zone until all tcpcbs are released as we attach
1607 * the allocations to them.
1608 */
1609 tcp_fastopen_destroy();
1610
1611 COUNTER_ARRAY_FREE(V_tcps_states, TCP_NSTATES);
1612 VNET_PCPUSTAT_FREE(tcpstat);
1613
1614 #ifdef TCP_HHOOK
1615 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
1616 if (error != 0) {
1617 printf("%s: WARNING: unable to deregister helper hook "
1618 "type=%d, id=%d: error %d returned\n", __func__,
1619 HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
1620 }
1621 error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
1622 if (error != 0) {
1623 printf("%s: WARNING: unable to deregister helper hook "
1624 "type=%d, id=%d: error %d returned\n", __func__,
1625 HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
1626 }
1627 #endif
1628 }
1629 VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL);
1630 #endif
1631
1632 void
tcp_fini(void * xtp)1633 tcp_fini(void *xtp)
1634 {
1635
1636 }
1637
1638 /*
1639 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb.
1640 * tcp_template used to store this data in mbufs, but we now recopy it out
1641 * of the tcpcb each time to conserve mbufs.
1642 */
1643 void
tcpip_fillheaders(struct inpcb * inp,uint16_t port,void * ip_ptr,void * tcp_ptr)1644 tcpip_fillheaders(struct inpcb *inp, uint16_t port, void *ip_ptr, void *tcp_ptr)
1645 {
1646 struct tcphdr *th = (struct tcphdr *)tcp_ptr;
1647
1648 INP_WLOCK_ASSERT(inp);
1649
1650 #ifdef INET6
1651 if ((inp->inp_vflag & INP_IPV6) != 0) {
1652 struct ip6_hdr *ip6;
1653
1654 ip6 = (struct ip6_hdr *)ip_ptr;
1655 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
1656 (inp->inp_flow & IPV6_FLOWINFO_MASK);
1657 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) |
1658 (IPV6_VERSION & IPV6_VERSION_MASK);
1659 if (port == 0)
1660 ip6->ip6_nxt = IPPROTO_TCP;
1661 else
1662 ip6->ip6_nxt = IPPROTO_UDP;
1663 ip6->ip6_plen = htons(sizeof(struct tcphdr));
1664 ip6->ip6_src = inp->in6p_laddr;
1665 ip6->ip6_dst = inp->in6p_faddr;
1666 }
1667 #endif /* INET6 */
1668 #if defined(INET6) && defined(INET)
1669 else
1670 #endif
1671 #ifdef INET
1672 {
1673 struct ip *ip;
1674
1675 ip = (struct ip *)ip_ptr;
1676 ip->ip_v = IPVERSION;
1677 ip->ip_hl = 5;
1678 ip->ip_tos = inp->inp_ip_tos;
1679 ip->ip_len = 0;
1680 ip->ip_id = 0;
1681 ip->ip_off = 0;
1682 ip->ip_ttl = inp->inp_ip_ttl;
1683 ip->ip_sum = 0;
1684 if (port == 0)
1685 ip->ip_p = IPPROTO_TCP;
1686 else
1687 ip->ip_p = IPPROTO_UDP;
1688 ip->ip_src = inp->inp_laddr;
1689 ip->ip_dst = inp->inp_faddr;
1690 }
1691 #endif /* INET */
1692 th->th_sport = inp->inp_lport;
1693 th->th_dport = inp->inp_fport;
1694 th->th_seq = 0;
1695 th->th_ack = 0;
1696 th->th_off = 5;
1697 tcp_set_flags(th, 0);
1698 th->th_win = 0;
1699 th->th_urp = 0;
1700 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
1701 }
1702
1703 /*
1704 * Create template to be used to send tcp packets on a connection.
1705 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only
1706 * use for this function is in keepalives, which use tcp_respond.
1707 */
1708 struct tcptemp *
tcpip_maketemplate(struct inpcb * inp)1709 tcpip_maketemplate(struct inpcb *inp)
1710 {
1711 struct tcptemp *t;
1712
1713 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
1714 if (t == NULL)
1715 return (NULL);
1716 tcpip_fillheaders(inp, 0, (void *)&t->tt_ipgen, (void *)&t->tt_t);
1717 return (t);
1718 }
1719
1720 /*
1721 * Send a single message to the TCP at address specified by
1722 * the given TCP/IP header. If m == NULL, then we make a copy
1723 * of the tcpiphdr at th and send directly to the addressed host.
1724 * This is used to force keep alive messages out using the TCP
1725 * template for a connection. If flags are given then we send
1726 * a message back to the TCP which originated the segment th,
1727 * and discard the mbuf containing it and any other attached mbufs.
1728 *
1729 * In any case the ack and sequence number of the transmitted
1730 * segment are as specified by the parameters.
1731 *
1732 * NOTE: If m != NULL, then th must point to *inside* the mbuf.
1733 */
1734
1735 void
tcp_respond(struct tcpcb * tp,void * ipgen,struct tcphdr * th,struct mbuf * m,tcp_seq ack,tcp_seq seq,uint16_t flags)1736 tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m,
1737 tcp_seq ack, tcp_seq seq, uint16_t flags)
1738 {
1739 struct tcpopt to;
1740 struct inpcb *inp;
1741 struct ip *ip;
1742 struct mbuf *optm;
1743 struct udphdr *uh = NULL;
1744 struct tcphdr *nth;
1745 struct tcp_log_buffer *lgb;
1746 u_char *optp;
1747 #ifdef INET6
1748 struct ip6_hdr *ip6;
1749 int isipv6;
1750 #endif /* INET6 */
1751 int optlen, tlen, win, ulen;
1752 int ect = 0;
1753 bool incl_opts;
1754 uint16_t port;
1755 int output_ret;
1756 #ifdef INVARIANTS
1757 int thflags = tcp_get_flags(th);
1758 #endif
1759
1760 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
1761 NET_EPOCH_ASSERT();
1762
1763 #ifdef INET6
1764 isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
1765 ip6 = ipgen;
1766 #endif /* INET6 */
1767 ip = ipgen;
1768
1769 if (tp != NULL) {
1770 inp = tptoinpcb(tp);
1771 INP_LOCK_ASSERT(inp);
1772 } else
1773 inp = NULL;
1774
1775 if (m != NULL) {
1776 #ifdef INET6
1777 if (isipv6 && ip6 && (ip6->ip6_nxt == IPPROTO_UDP))
1778 port = m->m_pkthdr.tcp_tun_port;
1779 else
1780 #endif
1781 if (ip && (ip->ip_p == IPPROTO_UDP))
1782 port = m->m_pkthdr.tcp_tun_port;
1783 else
1784 port = 0;
1785 } else
1786 port = tp->t_port;
1787
1788 incl_opts = false;
1789 win = 0;
1790 if (tp != NULL) {
1791 if (!(flags & TH_RST)) {
1792 win = sbspace(&inp->inp_socket->so_rcv);
1793 if (win > TCP_MAXWIN << tp->rcv_scale)
1794 win = TCP_MAXWIN << tp->rcv_scale;
1795 }
1796 if ((tp->t_flags & TF_NOOPT) == 0)
1797 incl_opts = true;
1798 }
1799 if (m == NULL) {
1800 m = m_gethdr(M_NOWAIT, MT_DATA);
1801 if (m == NULL)
1802 return;
1803 m->m_data += max_linkhdr;
1804 #ifdef INET6
1805 if (isipv6) {
1806 bcopy((caddr_t)ip6, mtod(m, caddr_t),
1807 sizeof(struct ip6_hdr));
1808 ip6 = mtod(m, struct ip6_hdr *);
1809 nth = (struct tcphdr *)(ip6 + 1);
1810 if (port) {
1811 /* Insert a UDP header */
1812 uh = (struct udphdr *)nth;
1813 uh->uh_sport = htons(V_tcp_udp_tunneling_port);
1814 uh->uh_dport = port;
1815 nth = (struct tcphdr *)(uh + 1);
1816 }
1817 } else
1818 #endif /* INET6 */
1819 {
1820 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
1821 ip = mtod(m, struct ip *);
1822 nth = (struct tcphdr *)(ip + 1);
1823 if (port) {
1824 /* Insert a UDP header */
1825 uh = (struct udphdr *)nth;
1826 uh->uh_sport = htons(V_tcp_udp_tunneling_port);
1827 uh->uh_dport = port;
1828 nth = (struct tcphdr *)(uh + 1);
1829 }
1830 }
1831 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1832 flags = TH_ACK;
1833 } else if ((!M_WRITABLE(m)) || (port != 0)) {
1834 struct mbuf *n;
1835
1836 /* Can't reuse 'm', allocate a new mbuf. */
1837 n = m_gethdr(M_NOWAIT, MT_DATA);
1838 if (n == NULL) {
1839 m_freem(m);
1840 return;
1841 }
1842
1843 if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
1844 m_freem(m);
1845 m_freem(n);
1846 return;
1847 }
1848
1849 n->m_data += max_linkhdr;
1850 /* m_len is set later */
1851 #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
1852 #ifdef INET6
1853 if (isipv6) {
1854 bcopy((caddr_t)ip6, mtod(n, caddr_t),
1855 sizeof(struct ip6_hdr));
1856 ip6 = mtod(n, struct ip6_hdr *);
1857 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1858 nth = (struct tcphdr *)(ip6 + 1);
1859 if (port) {
1860 /* Insert a UDP header */
1861 uh = (struct udphdr *)nth;
1862 uh->uh_sport = htons(V_tcp_udp_tunneling_port);
1863 uh->uh_dport = port;
1864 nth = (struct tcphdr *)(uh + 1);
1865 }
1866 } else
1867 #endif /* INET6 */
1868 {
1869 bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip));
1870 ip = mtod(n, struct ip *);
1871 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1872 nth = (struct tcphdr *)(ip + 1);
1873 if (port) {
1874 /* Insert a UDP header */
1875 uh = (struct udphdr *)nth;
1876 uh->uh_sport = htons(V_tcp_udp_tunneling_port);
1877 uh->uh_dport = port;
1878 nth = (struct tcphdr *)(uh + 1);
1879 }
1880 }
1881 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
1882 xchg(nth->th_dport, nth->th_sport, uint16_t);
1883 th = nth;
1884 m_freem(m);
1885 m = n;
1886 } else {
1887 /*
1888 * reuse the mbuf.
1889 * XXX MRT We inherit the FIB, which is lucky.
1890 */
1891 m_freem(m->m_next);
1892 m->m_next = NULL;
1893 m->m_data = (caddr_t)ipgen;
1894 /* clear any receive flags for proper bpf timestamping */
1895 m->m_flags &= ~(M_TSTMP | M_TSTMP_LRO);
1896 /* m_len is set later */
1897 #ifdef INET6
1898 if (isipv6) {
1899 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
1900 nth = (struct tcphdr *)(ip6 + 1);
1901 } else
1902 #endif /* INET6 */
1903 {
1904 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
1905 nth = (struct tcphdr *)(ip + 1);
1906 }
1907 if (th != nth) {
1908 /*
1909 * this is usually a case when an extension header
1910 * exists between the IPv6 header and the
1911 * TCP header.
1912 */
1913 nth->th_sport = th->th_sport;
1914 nth->th_dport = th->th_dport;
1915 }
1916 xchg(nth->th_dport, nth->th_sport, uint16_t);
1917 #undef xchg
1918 }
1919 tlen = 0;
1920 #ifdef INET6
1921 if (isipv6)
1922 tlen = sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
1923 #endif
1924 #if defined(INET) && defined(INET6)
1925 else
1926 #endif
1927 #ifdef INET
1928 tlen = sizeof (struct tcpiphdr);
1929 #endif
1930 if (port)
1931 tlen += sizeof (struct udphdr);
1932 #ifdef INVARIANTS
1933 m->m_len = 0;
1934 KASSERT(M_TRAILINGSPACE(m) >= tlen,
1935 ("Not enough trailing space for message (m=%p, need=%d, have=%ld)",
1936 m, tlen, (long)M_TRAILINGSPACE(m)));
1937 #endif
1938 m->m_len = tlen;
1939 to.to_flags = 0;
1940 if (incl_opts) {
1941 ect = tcp_ecn_output_established(tp, &flags, 0, false);
1942 /* Make sure we have room. */
1943 if (M_TRAILINGSPACE(m) < TCP_MAXOLEN) {
1944 m->m_next = m_get(M_NOWAIT, MT_DATA);
1945 if (m->m_next) {
1946 optp = mtod(m->m_next, u_char *);
1947 optm = m->m_next;
1948 } else
1949 incl_opts = false;
1950 } else {
1951 optp = (u_char *) (nth + 1);
1952 optm = m;
1953 }
1954 }
1955 if (incl_opts) {
1956 /* Timestamps. */
1957 if (tp->t_flags & TF_RCVD_TSTMP) {
1958 to.to_tsval = tcp_ts_getticks() + tp->ts_offset;
1959 to.to_tsecr = tp->ts_recent;
1960 to.to_flags |= TOF_TS;
1961 }
1962 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
1963 /* TCP-MD5 (RFC2385). */
1964 if (tp->t_flags & TF_SIGNATURE)
1965 to.to_flags |= TOF_SIGNATURE;
1966 #endif
1967 /* Add the options. */
1968 tlen += optlen = tcp_addoptions(&to, optp);
1969
1970 /* Update m_len in the correct mbuf. */
1971 optm->m_len += optlen;
1972 } else
1973 optlen = 0;
1974 #ifdef INET6
1975 if (isipv6) {
1976 if (uh) {
1977 ulen = tlen - sizeof(struct ip6_hdr);
1978 uh->uh_ulen = htons(ulen);
1979 }
1980 ip6->ip6_flow = htonl(ect << IPV6_FLOWLABEL_LEN);
1981 ip6->ip6_vfc = IPV6_VERSION;
1982 if (port)
1983 ip6->ip6_nxt = IPPROTO_UDP;
1984 else
1985 ip6->ip6_nxt = IPPROTO_TCP;
1986 ip6->ip6_plen = htons(tlen - sizeof(*ip6));
1987 }
1988 #endif
1989 #if defined(INET) && defined(INET6)
1990 else
1991 #endif
1992 #ifdef INET
1993 {
1994 if (uh) {
1995 ulen = tlen - sizeof(struct ip);
1996 uh->uh_ulen = htons(ulen);
1997 }
1998 ip->ip_len = htons(tlen);
1999 if (inp != NULL) {
2000 ip->ip_tos = inp->inp_ip_tos & ~IPTOS_ECN_MASK;
2001 ip->ip_ttl = inp->inp_ip_ttl;
2002 } else {
2003 ip->ip_tos = 0;
2004 ip->ip_ttl = V_ip_defttl;
2005 }
2006 ip->ip_tos |= ect;
2007 if (port) {
2008 ip->ip_p = IPPROTO_UDP;
2009 } else {
2010 ip->ip_p = IPPROTO_TCP;
2011 }
2012 if (V_path_mtu_discovery)
2013 ip->ip_off |= htons(IP_DF);
2014 }
2015 #endif
2016 m->m_pkthdr.len = tlen;
2017 m->m_pkthdr.rcvif = NULL;
2018 #ifdef MAC
2019 if (inp != NULL) {
2020 /*
2021 * Packet is associated with a socket, so allow the
2022 * label of the response to reflect the socket label.
2023 */
2024 INP_LOCK_ASSERT(inp);
2025 mac_inpcb_create_mbuf(inp, m);
2026 } else {
2027 /*
2028 * Packet is not associated with a socket, so possibly
2029 * update the label in place.
2030 */
2031 mac_netinet_tcp_reply(m);
2032 }
2033 #endif
2034 nth->th_seq = htonl(seq);
2035 nth->th_ack = htonl(ack);
2036 nth->th_off = (sizeof (struct tcphdr) + optlen) >> 2;
2037 tcp_set_flags(nth, flags);
2038 if (tp && (flags & TH_RST)) {
2039 /* Log the reset */
2040 tcp_log_end_status(tp, TCP_EI_STATUS_SERVER_RST);
2041 }
2042 if (tp != NULL)
2043 nth->th_win = htons((u_short) (win >> tp->rcv_scale));
2044 else
2045 nth->th_win = htons((u_short)win);
2046 nth->th_urp = 0;
2047
2048 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
2049 if (to.to_flags & TOF_SIGNATURE) {
2050 if (!TCPMD5_ENABLED() ||
2051 TCPMD5_OUTPUT(m, nth, to.to_signature) != 0) {
2052 m_freem(m);
2053 return;
2054 }
2055 }
2056 #endif
2057
2058 #ifdef INET6
2059 if (isipv6) {
2060 if (port) {
2061 m->m_pkthdr.csum_flags = CSUM_UDP_IPV6;
2062 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2063 uh->uh_sum = in6_cksum_pseudo(ip6, ulen, IPPROTO_UDP, 0);
2064 nth->th_sum = 0;
2065 } else {
2066 m->m_pkthdr.csum_flags = CSUM_TCP_IPV6;
2067 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2068 nth->th_sum = in6_cksum_pseudo(ip6,
2069 tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
2070 }
2071 ip6->ip6_hlim = in6_selecthlim(inp, NULL);
2072 }
2073 #endif /* INET6 */
2074 #if defined(INET6) && defined(INET)
2075 else
2076 #endif
2077 #ifdef INET
2078 {
2079 if (port) {
2080 uh->uh_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
2081 htons(ulen + IPPROTO_UDP));
2082 m->m_pkthdr.csum_flags = CSUM_UDP;
2083 m->m_pkthdr.csum_data = offsetof(struct udphdr, uh_sum);
2084 nth->th_sum = 0;
2085 } else {
2086 m->m_pkthdr.csum_flags = CSUM_TCP;
2087 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
2088 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr,
2089 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p)));
2090 }
2091 }
2092 #endif /* INET */
2093 TCP_PROBE3(debug__output, tp, th, m);
2094 if (flags & TH_RST)
2095 TCP_PROBE5(accept__refused, NULL, NULL, m, tp, nth);
2096 lgb = NULL;
2097 if ((tp != NULL) && tcp_bblogging_on(tp)) {
2098 if (INP_WLOCKED(inp)) {
2099 union tcp_log_stackspecific log;
2100 struct timeval tv;
2101
2102 memset(&log.u_bbr, 0, sizeof(log.u_bbr));
2103 log.u_bbr.inhpts = tcp_in_hpts(tp);
2104 log.u_bbr.flex8 = 4;
2105 log.u_bbr.pkts_out = tp->t_maxseg;
2106 log.u_bbr.timeStamp = tcp_get_usecs(&tv);
2107 log.u_bbr.delivered = 0;
2108 lgb = tcp_log_event(tp, nth, NULL, NULL, TCP_LOG_OUT,
2109 ERRNO_UNK, 0, &log, false, NULL, NULL, 0, &tv);
2110 } else {
2111 /*
2112 * We can not log the packet, since we only own the
2113 * read lock, but a write lock is needed. The read lock
2114 * is not upgraded to a write lock, since only getting
2115 * the read lock was done intentionally to improve the
2116 * handling of SYN flooding attacks.
2117 * This happens only for pure SYN segments received in
2118 * the initial CLOSED state, or received in a more
2119 * advanced state than listen and the UDP encapsulation
2120 * port is unexpected.
2121 * The incoming SYN segments do not really belong to
2122 * the TCP connection and the handling does not change
2123 * the state of the TCP connection. Therefore, the
2124 * sending of the RST segments is not logged. Please
2125 * note that also the incoming SYN segments are not
2126 * logged.
2127 *
2128 * The following code ensures that the above description
2129 * is and stays correct.
2130 */
2131 KASSERT((thflags & (TH_ACK|TH_SYN)) == TH_SYN &&
2132 (tp->t_state == TCPS_CLOSED ||
2133 (tp->t_state > TCPS_LISTEN && tp->t_port != port)),
2134 ("%s: Logging of TCP segment with flags 0x%b and "
2135 "UDP encapsulation port %u skipped in state %s",
2136 __func__, thflags, PRINT_TH_FLAGS,
2137 ntohs(port), tcpstates[tp->t_state]));
2138 }
2139 }
2140
2141 if (flags & TH_ACK)
2142 TCPSTAT_INC(tcps_sndacks);
2143 else if (flags & (TH_SYN|TH_FIN|TH_RST))
2144 TCPSTAT_INC(tcps_sndctrl);
2145 TCPSTAT_INC(tcps_sndtotal);
2146
2147 #ifdef INET6
2148 if (isipv6) {
2149 TCP_PROBE5(send, NULL, tp, ip6, tp, nth);
2150 output_ret = ip6_output(m, inp ? inp->in6p_outputopts : NULL,
2151 NULL, 0, NULL, NULL, inp);
2152 }
2153 #endif /* INET6 */
2154 #if defined(INET) && defined(INET6)
2155 else
2156 #endif
2157 #ifdef INET
2158 {
2159 TCP_PROBE5(send, NULL, tp, ip, tp, nth);
2160 output_ret = ip_output(m, NULL, NULL, 0, NULL, inp);
2161 }
2162 #endif
2163 if (lgb != NULL)
2164 lgb->tlb_errno = output_ret;
2165 }
2166
2167 /*
2168 * Send a challenge ack (no data, no SACK option), but not more than
2169 * V_tcp_ack_war_cnt per V_tcp_ack_war_time_window (per TCP connection).
2170 */
2171 void
tcp_send_challenge_ack(struct tcpcb * tp,struct tcphdr * th,struct mbuf * m)2172 tcp_send_challenge_ack(struct tcpcb *tp, struct tcphdr *th, struct mbuf *m)
2173 {
2174 sbintime_t now;
2175 bool send_challenge_ack;
2176
2177 if (V_tcp_ack_war_time_window == 0 || V_tcp_ack_war_cnt == 0) {
2178 /* ACK war protection is disabled. */
2179 send_challenge_ack = true;
2180 } else {
2181 /* Start new epoch, if the previous one is already over. */
2182 now = getsbinuptime();
2183 if (tp->t_challenge_ack_end < now) {
2184 tp->t_challenge_ack_cnt = 0;
2185 tp->t_challenge_ack_end = now +
2186 V_tcp_ack_war_time_window * SBT_1MS;
2187 }
2188 /*
2189 * Send a challenge ACK, if less than tcp_ack_war_cnt have been
2190 * sent in the current epoch.
2191 */
2192 if (tp->t_challenge_ack_cnt < V_tcp_ack_war_cnt) {
2193 send_challenge_ack = true;
2194 tp->t_challenge_ack_cnt++;
2195 } else {
2196 send_challenge_ack = false;
2197 }
2198 }
2199 if (send_challenge_ack) {
2200 tcp_respond(tp, mtod(m, void *), th, m, tp->rcv_nxt,
2201 tp->snd_nxt, TH_ACK);
2202 tp->last_ack_sent = tp->rcv_nxt;
2203 }
2204 }
2205
2206 /*
2207 * Create a new TCP control block, making an empty reassembly queue and hooking
2208 * it to the argument protocol control block. The `inp' parameter must have
2209 * come from the zone allocator set up by tcpcbstor declaration.
2210 * The caller can provide a pointer to a tcpcb of the listener to inherit the
2211 * TCP function block from the listener.
2212 */
2213 struct tcpcb *
tcp_newtcpcb(struct inpcb * inp,struct tcpcb * listening_tcb)2214 tcp_newtcpcb(struct inpcb *inp, struct tcpcb *listening_tcb)
2215 {
2216 struct tcpcb *tp = intotcpcb(inp);
2217 #ifdef INET6
2218 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
2219 #endif /* INET6 */
2220
2221 /*
2222 * Historically allocation was done with M_ZERO. There is a lot of
2223 * code that rely on that. For now take safe approach and zero whole
2224 * tcpcb. This definitely can be optimized.
2225 */
2226 bzero(&tp->t_start_zero, t_zero_size);
2227
2228 /* Initialise cc_var struct for this tcpcb. */
2229 tp->t_ccv.tp = tp;
2230 rw_rlock(&tcp_function_lock);
2231 if (listening_tcb != NULL) {
2232 INP_LOCK_ASSERT(tptoinpcb(listening_tcb));
2233 KASSERT(listening_tcb->t_fb != NULL,
2234 ("tcp_newtcpcb: listening_tcb->t_fb is NULL"));
2235 if (listening_tcb->t_fb->tfb_flags & TCP_FUNC_BEING_REMOVED) {
2236 rw_runlock(&tcp_function_lock);
2237 return (NULL);
2238 }
2239 tp->t_fb = listening_tcb->t_fb;
2240 } else {
2241 tp->t_fb = V_tcp_func_set_ptr;
2242 }
2243 refcount_acquire(&tp->t_fb->tfb_refcnt);
2244 KASSERT((tp->t_fb->tfb_flags & TCP_FUNC_BEING_REMOVED) == 0,
2245 ("tcp_newtcpcb: using TFB being removed"));
2246 rw_runlock(&tcp_function_lock);
2247 CC_LIST_RLOCK();
2248 if (listening_tcb != NULL) {
2249 if (CC_ALGO(listening_tcb)->flags & CC_MODULE_BEING_REMOVED) {
2250 CC_LIST_RUNLOCK();
2251 if (tp->t_fb->tfb_tcp_fb_fini)
2252 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2253 refcount_release(&tp->t_fb->tfb_refcnt);
2254 return (NULL);
2255 }
2256 CC_ALGO(tp) = CC_ALGO(listening_tcb);
2257 } else
2258 CC_ALGO(tp) = CC_DEFAULT_ALGO();
2259 cc_refer(CC_ALGO(tp));
2260 CC_LIST_RUNLOCK();
2261 if (CC_ALGO(tp)->cb_init != NULL)
2262 if (CC_ALGO(tp)->cb_init(&tp->t_ccv, NULL) > 0) {
2263 cc_detach(tp);
2264 if (tp->t_fb->tfb_tcp_fb_fini)
2265 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2266 refcount_release(&tp->t_fb->tfb_refcnt);
2267 return (NULL);
2268 }
2269
2270 #ifdef TCP_HHOOK
2271 if (khelp_init_osd(HELPER_CLASS_TCP, &tp->t_osd)) {
2272 if (CC_ALGO(tp)->cb_destroy != NULL)
2273 CC_ALGO(tp)->cb_destroy(&tp->t_ccv);
2274 CC_DATA(tp) = NULL;
2275 cc_detach(tp);
2276 if (tp->t_fb->tfb_tcp_fb_fini)
2277 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2278 refcount_release(&tp->t_fb->tfb_refcnt);
2279 return (NULL);
2280 }
2281 #endif
2282
2283 TAILQ_INIT(&tp->t_segq);
2284 STAILQ_INIT(&tp->t_inqueue);
2285 tp->t_maxseg =
2286 #ifdef INET6
2287 isipv6 ? V_tcp_v6mssdflt :
2288 #endif /* INET6 */
2289 V_tcp_mssdflt;
2290
2291 /* All mbuf queue/ack compress flags should be off */
2292 tcp_lro_features_off(tp);
2293
2294 tp->t_hpts_cpu = HPTS_CPU_NONE;
2295 tp->t_lro_cpu = HPTS_CPU_NONE;
2296
2297 callout_init_rw(&tp->t_callout, &inp->inp_lock,
2298 CALLOUT_TRYLOCK | CALLOUT_RETURNUNLOCKED);
2299 for (int i = 0; i < TT_N; i++)
2300 tp->t_timers[i] = SBT_MAX;
2301
2302 switch (V_tcp_do_rfc1323) {
2303 case 0:
2304 break;
2305 default:
2306 case 1:
2307 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
2308 break;
2309 case 2:
2310 tp->t_flags = TF_REQ_SCALE;
2311 break;
2312 case 3:
2313 tp->t_flags = TF_REQ_TSTMP;
2314 break;
2315 }
2316 if (V_tcp_do_sack)
2317 tp->t_flags |= TF_SACK_PERMIT;
2318 TAILQ_INIT(&tp->snd_holes);
2319
2320 /*
2321 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
2322 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives
2323 * reasonable initial retransmit time.
2324 */
2325 tp->t_srtt = TCPTV_SRTTBASE;
2326 tp->t_rttvar = ((tcp_rexmit_initial - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4;
2327 tp->t_rttmin = tcp_rexmit_min;
2328 tp->t_rxtcur = tcp_rexmit_initial;
2329 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
2330 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
2331 tp->t_rcvtime = ticks;
2332 /* We always start with ticks granularity */
2333 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS;
2334 /*
2335 * IPv4 TTL initialization is necessary for an IPv6 socket as well,
2336 * because the socket may be bound to an IPv6 wildcard address,
2337 * which may match an IPv4-mapped IPv6 address.
2338 */
2339 inp->inp_ip_ttl = V_ip_defttl;
2340 #ifdef TCPPCAP
2341 /*
2342 * Init the TCP PCAP queues.
2343 */
2344 tcp_pcap_tcpcb_init(tp);
2345 #endif
2346 #ifdef TCP_BLACKBOX
2347 /* Initialize the per-TCPCB log data. */
2348 tcp_log_tcpcbinit(tp);
2349 #endif
2350 tp->t_pacing_rate = -1;
2351 if (tp->t_fb->tfb_tcp_fb_init) {
2352 if ((*tp->t_fb->tfb_tcp_fb_init)(tp, &tp->t_fb_ptr)) {
2353 if (CC_ALGO(tp)->cb_destroy != NULL)
2354 CC_ALGO(tp)->cb_destroy(&tp->t_ccv);
2355 CC_DATA(tp) = NULL;
2356 cc_detach(tp);
2357 #ifdef TCP_HHOOK
2358 khelp_destroy_osd(&tp->t_osd);
2359 #endif
2360 refcount_release(&tp->t_fb->tfb_refcnt);
2361 return (NULL);
2362 }
2363 }
2364 #ifdef STATS
2365 if (V_tcp_perconn_stats_enable == 1)
2366 tp->t_stats = stats_blob_alloc(V_tcp_perconn_stats_dflt_tpl, 0);
2367 #endif
2368 if (V_tcp_do_lrd)
2369 tp->t_flags |= TF_LRD;
2370
2371 return (tp);
2372 }
2373
2374 /*
2375 * Drop a TCP connection, reporting
2376 * the specified error. If connection is synchronized,
2377 * then send a RST to peer.
2378 */
2379 struct tcpcb *
tcp_drop(struct tcpcb * tp,int errno)2380 tcp_drop(struct tcpcb *tp, int errno)
2381 {
2382 struct socket *so = tptosocket(tp);
2383
2384 NET_EPOCH_ASSERT();
2385 INP_WLOCK_ASSERT(tptoinpcb(tp));
2386
2387 if (TCPS_HAVERCVDSYN(tp->t_state)) {
2388 tcp_state_change(tp, TCPS_CLOSED);
2389 /* Don't use tcp_output() here due to possible recursion. */
2390 (void)tcp_output_nodrop(tp);
2391 TCPSTAT_INC(tcps_drops);
2392 } else
2393 TCPSTAT_INC(tcps_conndrops);
2394 if (errno == ETIMEDOUT && tp->t_softerror)
2395 errno = tp->t_softerror;
2396 so->so_error = errno;
2397 return (tcp_close(tp));
2398 }
2399
2400 void
tcp_discardcb(struct tcpcb * tp)2401 tcp_discardcb(struct tcpcb *tp)
2402 {
2403 struct inpcb *inp = tptoinpcb(tp);
2404 struct socket *so = tptosocket(tp);
2405 struct mbuf *m;
2406 #ifdef INET6
2407 bool isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
2408 #endif
2409
2410 INP_WLOCK_ASSERT(inp);
2411 MPASS(!callout_active(&tp->t_callout));
2412 MPASS(TAILQ_EMPTY(&tp->snd_holes));
2413
2414 /* free the reassembly queue, if any */
2415 tcp_reass_flush(tp);
2416
2417 #ifdef TCP_OFFLOAD
2418 /* Disconnect offload device, if any. */
2419 if (tp->t_flags & TF_TOE)
2420 tcp_offload_detach(tp);
2421 #endif
2422 #ifdef TCPPCAP
2423 /* Free the TCP PCAP queues. */
2424 tcp_pcap_drain(&(tp->t_inpkts));
2425 tcp_pcap_drain(&(tp->t_outpkts));
2426 #endif
2427
2428 /* Allow the CC algorithm to clean up after itself. */
2429 if (CC_ALGO(tp)->cb_destroy != NULL)
2430 CC_ALGO(tp)->cb_destroy(&tp->t_ccv);
2431 CC_DATA(tp) = NULL;
2432 /* Detach from the CC algorithm */
2433 cc_detach(tp);
2434
2435 #ifdef TCP_HHOOK
2436 khelp_destroy_osd(&tp->t_osd);
2437 #endif
2438 #ifdef STATS
2439 stats_blob_destroy(tp->t_stats);
2440 #endif
2441
2442 CC_ALGO(tp) = NULL;
2443 if ((m = STAILQ_FIRST(&tp->t_inqueue)) != NULL) {
2444 struct mbuf *prev;
2445
2446 STAILQ_INIT(&tp->t_inqueue);
2447 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, prev)
2448 m_freem(m);
2449 }
2450 TCPSTATES_DEC(tp->t_state);
2451
2452 if (tp->t_fb->tfb_tcp_fb_fini)
2453 (*tp->t_fb->tfb_tcp_fb_fini)(tp, 1);
2454 MPASS(!tcp_in_hpts(tp));
2455 #ifdef TCP_BLACKBOX
2456 tcp_log_tcpcbfini(tp);
2457 #endif
2458
2459 /*
2460 * If we got enough samples through the srtt filter,
2461 * save the rtt and rttvar in the routing entry.
2462 * 'Enough' is arbitrarily defined as 4 rtt samples.
2463 * 4 samples is enough for the srtt filter to converge
2464 * to within enough % of the correct value; fewer samples
2465 * and we could save a bogus rtt. The danger is not high
2466 * as tcp quickly recovers from everything.
2467 * XXX: Works very well but needs some more statistics!
2468 *
2469 * XXXRRS: Updating must be after the stack fini() since
2470 * that may be converting some internal representation of
2471 * say srtt etc into the general one used by other stacks.
2472 */
2473 if (tp->t_rttupdated >= 4) {
2474 struct hc_metrics_lite metrics;
2475 uint32_t ssthresh;
2476
2477 bzero(&metrics, sizeof(metrics));
2478 /*
2479 * Update the ssthresh always when the conditions below
2480 * are satisfied. This gives us better new start value
2481 * for the congestion avoidance for new connections.
2482 * ssthresh is only set if packet loss occurred on a session.
2483 */
2484 ssthresh = tp->snd_ssthresh;
2485 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
2486 /*
2487 * convert the limit from user data bytes to
2488 * packets then to packet data bytes.
2489 */
2490 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
2491 if (ssthresh < 2)
2492 ssthresh = 2;
2493 ssthresh *= (tp->t_maxseg +
2494 #ifdef INET6
2495 (isipv6 ? sizeof (struct ip6_hdr) +
2496 sizeof (struct tcphdr) :
2497 #endif
2498 sizeof (struct tcpiphdr)
2499 #ifdef INET6
2500 )
2501 #endif
2502 );
2503 } else
2504 ssthresh = 0;
2505 metrics.hc_ssthresh = ssthresh;
2506
2507 metrics.hc_rtt = tp->t_srtt;
2508 metrics.hc_rttvar = tp->t_rttvar;
2509 metrics.hc_cwnd = tp->snd_cwnd;
2510 metrics.hc_sendpipe = 0;
2511 metrics.hc_recvpipe = 0;
2512
2513 tcp_hc_update(&inp->inp_inc, &metrics);
2514 }
2515
2516 refcount_release(&tp->t_fb->tfb_refcnt);
2517 }
2518
2519 /*
2520 * Attempt to close a TCP control block, marking it as dropped, and freeing
2521 * the socket if we hold the only reference.
2522 */
2523 struct tcpcb *
tcp_close(struct tcpcb * tp)2524 tcp_close(struct tcpcb *tp)
2525 {
2526 struct inpcb *inp = tptoinpcb(tp);
2527 struct socket *so = tptosocket(tp);
2528
2529 INP_WLOCK_ASSERT(inp);
2530
2531 #ifdef TCP_OFFLOAD
2532 if (tp->t_state == TCPS_LISTEN)
2533 tcp_offload_listen_stop(tp);
2534 #endif
2535 /*
2536 * This releases the TFO pending counter resource for TFO listen
2537 * sockets as well as passively-created TFO sockets that transition
2538 * from SYN_RECEIVED to CLOSED.
2539 */
2540 if (tp->t_tfo_pending) {
2541 tcp_fastopen_decrement_counter(tp->t_tfo_pending);
2542 tp->t_tfo_pending = NULL;
2543 }
2544 tcp_timer_stop(tp);
2545 if (tp->t_fb->tfb_tcp_timer_stop_all != NULL)
2546 tp->t_fb->tfb_tcp_timer_stop_all(tp);
2547 in_pcbdrop(inp);
2548 TCPSTAT_INC(tcps_closed);
2549 if (tp->t_state != TCPS_CLOSED)
2550 tcp_state_change(tp, TCPS_CLOSED);
2551 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
2552 tcp_free_sackholes(tp);
2553 soisdisconnected(so);
2554 if (inp->inp_flags & INP_SOCKREF) {
2555 inp->inp_flags &= ~INP_SOCKREF;
2556 INP_WUNLOCK(inp);
2557 sorele(so);
2558 return (NULL);
2559 }
2560 return (tp);
2561 }
2562
2563 /*
2564 * Notify a tcp user of an asynchronous error;
2565 * store error as soft error, but wake up user
2566 * (for now, won't do anything until can select for soft error).
2567 *
2568 * Do not wake up user since there currently is no mechanism for
2569 * reporting soft errors (yet - a kqueue filter may be added).
2570 */
2571 static struct inpcb *
tcp_notify(struct inpcb * inp,int error)2572 tcp_notify(struct inpcb *inp, int error)
2573 {
2574 struct tcpcb *tp;
2575
2576 INP_WLOCK_ASSERT(inp);
2577
2578 tp = intotcpcb(inp);
2579 KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
2580
2581 /*
2582 * Ignore some errors if we are hooked up.
2583 * If connection hasn't completed, has retransmitted several times,
2584 * and receives a second error, give up now. This is better
2585 * than waiting a long time to establish a connection that
2586 * can never complete.
2587 */
2588 if (tp->t_state == TCPS_ESTABLISHED &&
2589 (error == EHOSTUNREACH || error == ENETUNREACH ||
2590 error == EHOSTDOWN)) {
2591 if (inp->inp_route.ro_nh) {
2592 NH_FREE(inp->inp_route.ro_nh);
2593 inp->inp_route.ro_nh = (struct nhop_object *)NULL;
2594 }
2595 return (inp);
2596 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
2597 tp->t_softerror) {
2598 tp = tcp_drop(tp, error);
2599 if (tp != NULL)
2600 return (inp);
2601 else
2602 return (NULL);
2603 } else {
2604 tp->t_softerror = error;
2605 return (inp);
2606 }
2607 #if 0
2608 wakeup( &so->so_timeo);
2609 sorwakeup(so);
2610 sowwakeup(so);
2611 #endif
2612 }
2613
2614 static int
tcp_pcblist(SYSCTL_HANDLER_ARGS)2615 tcp_pcblist(SYSCTL_HANDLER_ARGS)
2616 {
2617 struct inpcb_iterator inpi = INP_ALL_ITERATOR(&V_tcbinfo,
2618 INPLOOKUP_RLOCKPCB);
2619 struct xinpgen xig;
2620 struct inpcb *inp;
2621 int error;
2622
2623 if (req->newptr != NULL)
2624 return (EPERM);
2625
2626 if (req->oldptr == NULL) {
2627 int n;
2628
2629 n = V_tcbinfo.ipi_count +
2630 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2631 n += imax(n / 8, 10);
2632 req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
2633 return (0);
2634 }
2635
2636 if ((error = sysctl_wire_old_buffer(req, 0)) != 0)
2637 return (error);
2638
2639 bzero(&xig, sizeof(xig));
2640 xig.xig_len = sizeof xig;
2641 xig.xig_count = V_tcbinfo.ipi_count +
2642 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2643 xig.xig_gen = V_tcbinfo.ipi_gencnt;
2644 xig.xig_sogen = so_gencnt;
2645 error = SYSCTL_OUT(req, &xig, sizeof xig);
2646 if (error)
2647 return (error);
2648
2649 error = syncache_pcblist(req);
2650 if (error)
2651 return (error);
2652
2653 while ((inp = inp_next(&inpi)) != NULL) {
2654 if (inp->inp_gencnt <= xig.xig_gen &&
2655 cr_canseeinpcb(req->td->td_ucred, inp) == 0) {
2656 struct xtcpcb xt;
2657
2658 tcp_inptoxtp(inp, &xt);
2659 error = SYSCTL_OUT(req, &xt, sizeof xt);
2660 if (error) {
2661 INP_RUNLOCK(inp);
2662 break;
2663 } else
2664 continue;
2665 }
2666 }
2667
2668 if (!error) {
2669 /*
2670 * Give the user an updated idea of our state.
2671 * If the generation differs from what we told
2672 * her before, she knows that something happened
2673 * while we were processing this request, and it
2674 * might be necessary to retry.
2675 */
2676 xig.xig_gen = V_tcbinfo.ipi_gencnt;
2677 xig.xig_sogen = so_gencnt;
2678 xig.xig_count = V_tcbinfo.ipi_count +
2679 counter_u64_fetch(V_tcps_states[TCPS_SYN_RECEIVED]);
2680 error = SYSCTL_OUT(req, &xig, sizeof xig);
2681 }
2682
2683 return (error);
2684 }
2685
2686 SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
2687 CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_NEEDGIANT,
2688 NULL, 0, tcp_pcblist, "S,xtcpcb",
2689 "List of active TCP connections");
2690
2691 #ifdef INET
2692 static int
tcp_getcred(SYSCTL_HANDLER_ARGS)2693 tcp_getcred(SYSCTL_HANDLER_ARGS)
2694 {
2695 struct xucred xuc;
2696 struct sockaddr_in addrs[2];
2697 struct epoch_tracker et;
2698 struct inpcb *inp;
2699 int error;
2700
2701 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2702 if (error)
2703 return (error);
2704 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2705 if (error)
2706 return (error);
2707 NET_EPOCH_ENTER(et);
2708 inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
2709 addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
2710 NET_EPOCH_EXIT(et);
2711 if (inp != NULL) {
2712 if (error == 0)
2713 error = cr_canseeinpcb(req->td->td_ucred, inp);
2714 if (error == 0)
2715 cru2x(inp->inp_cred, &xuc);
2716 INP_RUNLOCK(inp);
2717 } else
2718 error = ENOENT;
2719 if (error == 0)
2720 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2721 return (error);
2722 }
2723
2724 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
2725 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT,
2726 0, 0, tcp_getcred, "S,xucred",
2727 "Get the xucred of a TCP connection");
2728 #endif /* INET */
2729
2730 #ifdef INET6
2731 static int
tcp6_getcred(SYSCTL_HANDLER_ARGS)2732 tcp6_getcred(SYSCTL_HANDLER_ARGS)
2733 {
2734 struct epoch_tracker et;
2735 struct xucred xuc;
2736 struct sockaddr_in6 addrs[2];
2737 struct inpcb *inp;
2738 int error;
2739 #ifdef INET
2740 int mapped = 0;
2741 #endif
2742
2743 error = priv_check(req->td, PRIV_NETINET_GETCRED);
2744 if (error)
2745 return (error);
2746 error = SYSCTL_IN(req, addrs, sizeof(addrs));
2747 if (error)
2748 return (error);
2749 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
2750 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
2751 return (error);
2752 }
2753 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
2754 #ifdef INET
2755 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
2756 mapped = 1;
2757 else
2758 #endif
2759 return (EINVAL);
2760 }
2761
2762 NET_EPOCH_ENTER(et);
2763 #ifdef INET
2764 if (mapped == 1)
2765 inp = in_pcblookup(&V_tcbinfo,
2766 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
2767 addrs[1].sin6_port,
2768 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
2769 addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
2770 else
2771 #endif
2772 inp = in6_pcblookup(&V_tcbinfo,
2773 &addrs[1].sin6_addr, addrs[1].sin6_port,
2774 &addrs[0].sin6_addr, addrs[0].sin6_port,
2775 INPLOOKUP_RLOCKPCB, NULL);
2776 NET_EPOCH_EXIT(et);
2777 if (inp != NULL) {
2778 if (error == 0)
2779 error = cr_canseeinpcb(req->td->td_ucred, inp);
2780 if (error == 0)
2781 cru2x(inp->inp_cred, &xuc);
2782 INP_RUNLOCK(inp);
2783 } else
2784 error = ENOENT;
2785 if (error == 0)
2786 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
2787 return (error);
2788 }
2789
2790 SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
2791 CTLTYPE_OPAQUE | CTLFLAG_RW | CTLFLAG_PRISON | CTLFLAG_NEEDGIANT,
2792 0, 0, tcp6_getcred, "S,xucred",
2793 "Get the xucred of a TCP6 connection");
2794 #endif /* INET6 */
2795
2796 #ifdef INET
2797 /* Path MTU to try next when a fragmentation-needed message is received. */
2798 static inline int
tcp_next_pmtu(const struct icmp * icp,const struct ip * ip)2799 tcp_next_pmtu(const struct icmp *icp, const struct ip *ip)
2800 {
2801 int mtu = ntohs(icp->icmp_nextmtu);
2802
2803 /* If no alternative MTU was proposed, try the next smaller one. */
2804 if (!mtu)
2805 mtu = ip_next_mtu(ntohs(ip->ip_len), 1);
2806 if (mtu < V_tcp_minmss + sizeof(struct tcpiphdr))
2807 mtu = V_tcp_minmss + sizeof(struct tcpiphdr);
2808
2809 return (mtu);
2810 }
2811
2812 static void
tcp_ctlinput_with_port(struct icmp * icp,uint16_t port)2813 tcp_ctlinput_with_port(struct icmp *icp, uint16_t port)
2814 {
2815 struct ip *ip;
2816 struct tcphdr *th;
2817 struct inpcb *inp;
2818 struct tcpcb *tp;
2819 struct inpcb *(*notify)(struct inpcb *, int);
2820 struct in_conninfo inc;
2821 tcp_seq icmp_tcp_seq;
2822 int errno, mtu;
2823
2824 errno = icmp_errmap(icp);
2825 switch (errno) {
2826 case 0:
2827 return;
2828 case EMSGSIZE:
2829 notify = tcp_mtudisc_notify;
2830 break;
2831 case ECONNREFUSED:
2832 if (V_icmp_may_rst)
2833 notify = tcp_drop_syn_sent;
2834 else
2835 notify = tcp_notify;
2836 break;
2837 case EHOSTUNREACH:
2838 if (V_icmp_may_rst && icp->icmp_type == ICMP_TIMXCEED)
2839 notify = tcp_drop_syn_sent;
2840 else
2841 notify = tcp_notify;
2842 break;
2843 default:
2844 notify = tcp_notify;
2845 }
2846
2847 ip = &icp->icmp_ip;
2848 th = (struct tcphdr *)((caddr_t)ip + (ip->ip_hl << 2));
2849 icmp_tcp_seq = th->th_seq;
2850 inp = in_pcblookup(&V_tcbinfo, ip->ip_dst, th->th_dport, ip->ip_src,
2851 th->th_sport, INPLOOKUP_WLOCKPCB, NULL);
2852 if (inp != NULL) {
2853 tp = intotcpcb(inp);
2854 #ifdef TCP_OFFLOAD
2855 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) {
2856 /*
2857 * MTU discovery for offloaded connections. Let
2858 * the TOE driver verify seq# and process it.
2859 */
2860 mtu = tcp_next_pmtu(icp, ip);
2861 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu);
2862 goto out;
2863 }
2864 #endif
2865 if (tp->t_port != port)
2866 goto out;
2867 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
2868 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
2869 if (errno == EMSGSIZE) {
2870 /*
2871 * MTU discovery: we got a needfrag and
2872 * will potentially try a lower MTU.
2873 */
2874 mtu = tcp_next_pmtu(icp, ip);
2875
2876 /*
2877 * Only process the offered MTU if it
2878 * is smaller than the current one.
2879 */
2880 if (mtu < tp->t_maxseg +
2881 sizeof(struct tcpiphdr)) {
2882 bzero(&inc, sizeof(inc));
2883 inc.inc_faddr = ip->ip_dst;
2884 inc.inc_fibnum =
2885 inp->inp_inc.inc_fibnum;
2886 tcp_hc_updatemtu(&inc, mtu);
2887 inp = tcp_mtudisc(inp, mtu);
2888 }
2889 } else
2890 inp = (*notify)(inp, errno);
2891 }
2892 } else {
2893 bzero(&inc, sizeof(inc));
2894 inc.inc_fport = th->th_dport;
2895 inc.inc_lport = th->th_sport;
2896 inc.inc_faddr = ip->ip_dst;
2897 inc.inc_laddr = ip->ip_src;
2898 syncache_unreach(&inc, icmp_tcp_seq, port);
2899 }
2900 out:
2901 if (inp != NULL)
2902 INP_WUNLOCK(inp);
2903 }
2904
2905 static void
tcp_ctlinput(struct icmp * icmp)2906 tcp_ctlinput(struct icmp *icmp)
2907 {
2908 tcp_ctlinput_with_port(icmp, htons(0));
2909 }
2910
2911 static void
tcp_ctlinput_viaudp(udp_tun_icmp_param_t param)2912 tcp_ctlinput_viaudp(udp_tun_icmp_param_t param)
2913 {
2914 /* Its a tunneled TCP over UDP icmp */
2915 struct icmp *icmp = param.icmp;
2916 struct ip *outer_ip, *inner_ip;
2917 struct udphdr *udp;
2918 struct tcphdr *th, ttemp;
2919 int i_hlen, o_len;
2920 uint16_t port;
2921
2922 outer_ip = (struct ip *)((caddr_t)icmp - sizeof(struct ip));
2923 inner_ip = &icmp->icmp_ip;
2924 i_hlen = inner_ip->ip_hl << 2;
2925 o_len = ntohs(outer_ip->ip_len);
2926 if (o_len <
2927 (sizeof(struct ip) + 8 + i_hlen + sizeof(struct udphdr) + offsetof(struct tcphdr, th_ack))) {
2928 /* Not enough data present */
2929 return;
2930 }
2931 /* Ok lets strip out the inner udphdr header by copying up on top of it the tcp hdr */
2932 udp = (struct udphdr *)(((caddr_t)inner_ip) + i_hlen);
2933 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) {
2934 return;
2935 }
2936 port = udp->uh_dport;
2937 th = (struct tcphdr *)(udp + 1);
2938 memcpy(&ttemp, th, sizeof(struct tcphdr));
2939 memcpy(udp, &ttemp, sizeof(struct tcphdr));
2940 /* Now adjust down the size of the outer IP header */
2941 o_len -= sizeof(struct udphdr);
2942 outer_ip->ip_len = htons(o_len);
2943 /* Now call in to the normal handling code */
2944 tcp_ctlinput_with_port(icmp, port);
2945 }
2946 #endif /* INET */
2947
2948 #ifdef INET6
2949 static inline int
tcp6_next_pmtu(const struct icmp6_hdr * icmp6)2950 tcp6_next_pmtu(const struct icmp6_hdr *icmp6)
2951 {
2952 int mtu = ntohl(icmp6->icmp6_mtu);
2953
2954 /*
2955 * If no alternative MTU was proposed, or the proposed MTU was too
2956 * small, set to the min.
2957 */
2958 if (mtu < IPV6_MMTU)
2959 mtu = IPV6_MMTU - 8; /* XXXNP: what is the adjustment for? */
2960 return (mtu);
2961 }
2962
2963 static void
tcp6_ctlinput_with_port(struct ip6ctlparam * ip6cp,uint16_t port)2964 tcp6_ctlinput_with_port(struct ip6ctlparam *ip6cp, uint16_t port)
2965 {
2966 struct in6_addr *dst;
2967 struct inpcb *(*notify)(struct inpcb *, int);
2968 struct ip6_hdr *ip6;
2969 struct mbuf *m;
2970 struct inpcb *inp;
2971 struct tcpcb *tp;
2972 struct icmp6_hdr *icmp6;
2973 struct in_conninfo inc;
2974 struct tcp_ports {
2975 uint16_t th_sport;
2976 uint16_t th_dport;
2977 } t_ports;
2978 tcp_seq icmp_tcp_seq;
2979 unsigned int mtu;
2980 unsigned int off;
2981 int errno;
2982
2983 icmp6 = ip6cp->ip6c_icmp6;
2984 m = ip6cp->ip6c_m;
2985 ip6 = ip6cp->ip6c_ip6;
2986 off = ip6cp->ip6c_off;
2987 dst = &ip6cp->ip6c_finaldst->sin6_addr;
2988
2989 errno = icmp6_errmap(icmp6);
2990 switch (errno) {
2991 case 0:
2992 return;
2993 case EMSGSIZE:
2994 notify = tcp_mtudisc_notify;
2995 break;
2996 case ECONNREFUSED:
2997 if (V_icmp_may_rst)
2998 notify = tcp_drop_syn_sent;
2999 else
3000 notify = tcp_notify;
3001 break;
3002 case EHOSTUNREACH:
3003 /*
3004 * There are only four ICMPs that may reset connection:
3005 * - administratively prohibited
3006 * - port unreachable
3007 * - time exceeded in transit
3008 * - unknown next header
3009 */
3010 if (V_icmp_may_rst &&
3011 ((icmp6->icmp6_type == ICMP6_DST_UNREACH &&
3012 (icmp6->icmp6_code == ICMP6_DST_UNREACH_ADMIN ||
3013 icmp6->icmp6_code == ICMP6_DST_UNREACH_NOPORT)) ||
3014 (icmp6->icmp6_type == ICMP6_TIME_EXCEEDED &&
3015 icmp6->icmp6_code == ICMP6_TIME_EXCEED_TRANSIT) ||
3016 (icmp6->icmp6_type == ICMP6_PARAM_PROB &&
3017 icmp6->icmp6_code == ICMP6_PARAMPROB_NEXTHEADER)))
3018 notify = tcp_drop_syn_sent;
3019 else
3020 notify = tcp_notify;
3021 break;
3022 default:
3023 notify = tcp_notify;
3024 }
3025
3026 /* Check if we can safely get the ports from the tcp hdr */
3027 if (m == NULL ||
3028 (m->m_pkthdr.len <
3029 (int32_t) (off + sizeof(struct tcp_ports)))) {
3030 return;
3031 }
3032 bzero(&t_ports, sizeof(struct tcp_ports));
3033 m_copydata(m, off, sizeof(struct tcp_ports), (caddr_t)&t_ports);
3034 inp = in6_pcblookup(&V_tcbinfo, &ip6->ip6_dst, t_ports.th_dport,
3035 &ip6->ip6_src, t_ports.th_sport, INPLOOKUP_WLOCKPCB, NULL);
3036 off += sizeof(struct tcp_ports);
3037 if (m->m_pkthdr.len < (int32_t) (off + sizeof(tcp_seq))) {
3038 goto out;
3039 }
3040 m_copydata(m, off, sizeof(tcp_seq), (caddr_t)&icmp_tcp_seq);
3041 if (inp != NULL) {
3042 tp = intotcpcb(inp);
3043 #ifdef TCP_OFFLOAD
3044 if (tp->t_flags & TF_TOE && errno == EMSGSIZE) {
3045 /* MTU discovery for offloaded connections. */
3046 mtu = tcp6_next_pmtu(icmp6);
3047 tcp_offload_pmtu_update(tp, icmp_tcp_seq, mtu);
3048 goto out;
3049 }
3050 #endif
3051 if (tp->t_port != port)
3052 goto out;
3053 if (SEQ_GEQ(ntohl(icmp_tcp_seq), tp->snd_una) &&
3054 SEQ_LT(ntohl(icmp_tcp_seq), tp->snd_max)) {
3055 if (errno == EMSGSIZE) {
3056 /*
3057 * MTU discovery:
3058 * If we got a needfrag set the MTU
3059 * in the route to the suggested new
3060 * value (if given) and then notify.
3061 */
3062 mtu = tcp6_next_pmtu(icmp6);
3063
3064 bzero(&inc, sizeof(inc));
3065 inc.inc_fibnum = M_GETFIB(m);
3066 inc.inc_flags |= INC_ISIPV6;
3067 inc.inc6_faddr = *dst;
3068 if (in6_setscope(&inc.inc6_faddr,
3069 m->m_pkthdr.rcvif, NULL))
3070 goto out;
3071 /*
3072 * Only process the offered MTU if it
3073 * is smaller than the current one.
3074 */
3075 if (mtu < tp->t_maxseg +
3076 sizeof (struct tcphdr) +
3077 sizeof (struct ip6_hdr)) {
3078 tcp_hc_updatemtu(&inc, mtu);
3079 tcp_mtudisc(inp, mtu);
3080 ICMP6STAT_INC(icp6s_pmtuchg);
3081 }
3082 } else
3083 inp = (*notify)(inp, errno);
3084 }
3085 } else {
3086 bzero(&inc, sizeof(inc));
3087 inc.inc_fibnum = M_GETFIB(m);
3088 inc.inc_flags |= INC_ISIPV6;
3089 inc.inc_fport = t_ports.th_dport;
3090 inc.inc_lport = t_ports.th_sport;
3091 inc.inc6_faddr = *dst;
3092 inc.inc6_laddr = ip6->ip6_src;
3093 syncache_unreach(&inc, icmp_tcp_seq, port);
3094 }
3095 out:
3096 if (inp != NULL)
3097 INP_WUNLOCK(inp);
3098 }
3099
3100 static void
tcp6_ctlinput(struct ip6ctlparam * ctl)3101 tcp6_ctlinput(struct ip6ctlparam *ctl)
3102 {
3103 tcp6_ctlinput_with_port(ctl, htons(0));
3104 }
3105
3106 static void
tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param)3107 tcp6_ctlinput_viaudp(udp_tun_icmp_param_t param)
3108 {
3109 struct ip6ctlparam *ip6cp = param.ip6cp;
3110 struct mbuf *m;
3111 struct udphdr *udp;
3112 uint16_t port;
3113
3114 m = m_pulldown(ip6cp->ip6c_m, ip6cp->ip6c_off, sizeof(struct udphdr), NULL);
3115 if (m == NULL) {
3116 return;
3117 }
3118 udp = mtod(m, struct udphdr *);
3119 if (ntohs(udp->uh_sport) != V_tcp_udp_tunneling_port) {
3120 return;
3121 }
3122 port = udp->uh_dport;
3123 m_adj(m, sizeof(struct udphdr));
3124 if ((m->m_flags & M_PKTHDR) == 0) {
3125 ip6cp->ip6c_m->m_pkthdr.len -= sizeof(struct udphdr);
3126 }
3127 /* Now call in to the normal handling code */
3128 tcp6_ctlinput_with_port(ip6cp, port);
3129 }
3130
3131 #endif /* INET6 */
3132
3133 static uint32_t
tcp_keyed_hash(struct in_conninfo * inc,u_char * key,u_int len)3134 tcp_keyed_hash(struct in_conninfo *inc, u_char *key, u_int len)
3135 {
3136 SIPHASH_CTX ctx;
3137 uint32_t hash[2];
3138
3139 KASSERT(len >= SIPHASH_KEY_LENGTH,
3140 ("%s: keylen %u too short ", __func__, len));
3141 SipHash24_Init(&ctx);
3142 SipHash_SetKey(&ctx, (uint8_t *)key);
3143 SipHash_Update(&ctx, &inc->inc_fport, sizeof(uint16_t));
3144 SipHash_Update(&ctx, &inc->inc_lport, sizeof(uint16_t));
3145 switch (inc->inc_flags & INC_ISIPV6) {
3146 #ifdef INET
3147 case 0:
3148 SipHash_Update(&ctx, &inc->inc_faddr, sizeof(struct in_addr));
3149 SipHash_Update(&ctx, &inc->inc_laddr, sizeof(struct in_addr));
3150 break;
3151 #endif
3152 #ifdef INET6
3153 case INC_ISIPV6:
3154 SipHash_Update(&ctx, &inc->inc6_faddr, sizeof(struct in6_addr));
3155 SipHash_Update(&ctx, &inc->inc6_laddr, sizeof(struct in6_addr));
3156 break;
3157 #endif
3158 }
3159 SipHash_Final((uint8_t *)hash, &ctx);
3160
3161 return (hash[0] ^ hash[1]);
3162 }
3163
3164 uint32_t
tcp_new_ts_offset(struct in_conninfo * inc)3165 tcp_new_ts_offset(struct in_conninfo *inc)
3166 {
3167 struct in_conninfo inc_store, *local_inc;
3168
3169 if (!V_tcp_ts_offset_per_conn) {
3170 memcpy(&inc_store, inc, sizeof(struct in_conninfo));
3171 inc_store.inc_lport = 0;
3172 inc_store.inc_fport = 0;
3173 local_inc = &inc_store;
3174 } else {
3175 local_inc = inc;
3176 }
3177 return (tcp_keyed_hash(local_inc, V_ts_offset_secret,
3178 sizeof(V_ts_offset_secret)));
3179 }
3180
3181 /*
3182 * Following is where TCP initial sequence number generation occurs.
3183 *
3184 * There are two places where we must use initial sequence numbers:
3185 * 1. In SYN-ACK packets.
3186 * 2. In SYN packets.
3187 *
3188 * All ISNs for SYN-ACK packets are generated by the syncache. See
3189 * tcp_syncache.c for details.
3190 *
3191 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling
3192 * depends on this property. In addition, these ISNs should be
3193 * unguessable so as to prevent connection hijacking. To satisfy
3194 * the requirements of this situation, the algorithm outlined in
3195 * RFC 1948 is used, with only small modifications.
3196 *
3197 * Implementation details:
3198 *
3199 * Time is based off the system timer, and is corrected so that it
3200 * increases by one megabyte per second. This allows for proper
3201 * recycling on high speed LANs while still leaving over an hour
3202 * before rollover.
3203 *
3204 * As reading the *exact* system time is too expensive to be done
3205 * whenever setting up a TCP connection, we increment the time
3206 * offset in two ways. First, a small random positive increment
3207 * is added to isn_offset for each connection that is set up.
3208 * Second, the function tcp_isn_tick fires once per clock tick
3209 * and increments isn_offset as necessary so that sequence numbers
3210 * are incremented at approximately ISN_BYTES_PER_SECOND. The
3211 * random positive increments serve only to ensure that the same
3212 * exact sequence number is never sent out twice (as could otherwise
3213 * happen when a port is recycled in less than the system tick
3214 * interval.)
3215 *
3216 * net.inet.tcp.isn_reseed_interval controls the number of seconds
3217 * between seeding of isn_secret. This is normally set to zero,
3218 * as reseeding should not be necessary.
3219 *
3220 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
3221 * isn_offset_old, and isn_ctx is performed using the ISN lock. In
3222 * general, this means holding an exclusive (write) lock.
3223 */
3224
3225 #define ISN_BYTES_PER_SECOND 1048576
3226 #define ISN_STATIC_INCREMENT 4096
3227 #define ISN_RANDOM_INCREMENT (4096 - 1)
3228 #define ISN_SECRET_LENGTH SIPHASH_KEY_LENGTH
3229
3230 VNET_DEFINE_STATIC(u_char, isn_secret[ISN_SECRET_LENGTH]);
3231 VNET_DEFINE_STATIC(int, isn_last);
3232 VNET_DEFINE_STATIC(int, isn_last_reseed);
3233 VNET_DEFINE_STATIC(u_int32_t, isn_offset);
3234 VNET_DEFINE_STATIC(u_int32_t, isn_offset_old);
3235
3236 #define V_isn_secret VNET(isn_secret)
3237 #define V_isn_last VNET(isn_last)
3238 #define V_isn_last_reseed VNET(isn_last_reseed)
3239 #define V_isn_offset VNET(isn_offset)
3240 #define V_isn_offset_old VNET(isn_offset_old)
3241
3242 tcp_seq
tcp_new_isn(struct in_conninfo * inc)3243 tcp_new_isn(struct in_conninfo *inc)
3244 {
3245 tcp_seq new_isn;
3246 u_int32_t projected_offset;
3247
3248 ISN_LOCK();
3249 /* Seed if this is the first use, reseed if requested. */
3250 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
3251 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
3252 < (u_int)ticks))) {
3253 arc4rand(&V_isn_secret, sizeof(V_isn_secret), 0);
3254 V_isn_last_reseed = ticks;
3255 }
3256
3257 /* Compute the hash and return the ISN. */
3258 new_isn = (tcp_seq)tcp_keyed_hash(inc, V_isn_secret,
3259 sizeof(V_isn_secret));
3260 V_isn_offset += ISN_STATIC_INCREMENT +
3261 (arc4random() & ISN_RANDOM_INCREMENT);
3262 if (ticks != V_isn_last) {
3263 projected_offset = V_isn_offset_old +
3264 ISN_BYTES_PER_SECOND / hz * (ticks - V_isn_last);
3265 if (SEQ_GT(projected_offset, V_isn_offset))
3266 V_isn_offset = projected_offset;
3267 V_isn_offset_old = V_isn_offset;
3268 V_isn_last = ticks;
3269 }
3270 new_isn += V_isn_offset;
3271 ISN_UNLOCK();
3272 return (new_isn);
3273 }
3274
3275 /*
3276 * When a specific ICMP unreachable message is received and the
3277 * connection state is SYN-SENT, drop the connection. This behavior
3278 * is controlled by the icmp_may_rst sysctl.
3279 */
3280 static struct inpcb *
tcp_drop_syn_sent(struct inpcb * inp,int errno)3281 tcp_drop_syn_sent(struct inpcb *inp, int errno)
3282 {
3283 struct tcpcb *tp;
3284
3285 NET_EPOCH_ASSERT();
3286 INP_WLOCK_ASSERT(inp);
3287
3288 tp = intotcpcb(inp);
3289 if (tp->t_state != TCPS_SYN_SENT)
3290 return (inp);
3291
3292 if (tp->t_flags & TF_FASTOPEN)
3293 tcp_fastopen_disable_path(tp);
3294
3295 tp = tcp_drop(tp, errno);
3296 if (tp != NULL)
3297 return (inp);
3298 else
3299 return (NULL);
3300 }
3301
3302 /*
3303 * When `need fragmentation' ICMP is received, update our idea of the MSS
3304 * based on the new value. Also nudge TCP to send something, since we
3305 * know the packet we just sent was dropped.
3306 * This duplicates some code in the tcp_mss() function in tcp_input.c.
3307 */
3308 static struct inpcb *
tcp_mtudisc_notify(struct inpcb * inp,int error)3309 tcp_mtudisc_notify(struct inpcb *inp, int error)
3310 {
3311
3312 return (tcp_mtudisc(inp, -1));
3313 }
3314
3315 static struct inpcb *
tcp_mtudisc(struct inpcb * inp,int mtuoffer)3316 tcp_mtudisc(struct inpcb *inp, int mtuoffer)
3317 {
3318 struct tcpcb *tp;
3319 struct socket *so;
3320
3321 INP_WLOCK_ASSERT(inp);
3322
3323 tp = intotcpcb(inp);
3324 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
3325
3326 tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
3327
3328 so = inp->inp_socket;
3329 SOCK_SENDBUF_LOCK(so);
3330 /* If the mss is larger than the socket buffer, decrease the mss. */
3331 if (so->so_snd.sb_hiwat < tp->t_maxseg) {
3332 tp->t_maxseg = so->so_snd.sb_hiwat;
3333 if (tp->t_maxseg < V_tcp_mssdflt) {
3334 /*
3335 * The MSS is so small we should not process incoming
3336 * SACK's since we are subject to attack in such a
3337 * case.
3338 */
3339 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
3340 } else {
3341 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
3342 }
3343 }
3344 SOCK_SENDBUF_UNLOCK(so);
3345
3346 TCPSTAT_INC(tcps_mturesent);
3347 tp->t_rtttime = 0;
3348 tp->snd_nxt = tp->snd_una;
3349 tcp_free_sackholes(tp);
3350 tp->snd_recover = tp->snd_max;
3351 if (tp->t_flags & TF_SACK_PERMIT)
3352 EXIT_FASTRECOVERY(tp->t_flags);
3353 if (tp->t_fb->tfb_tcp_mtu_chg != NULL) {
3354 /*
3355 * Conceptually the snd_nxt setting
3356 * and freeing sack holes should
3357 * be done by the default stacks
3358 * own tfb_tcp_mtu_chg().
3359 */
3360 tp->t_fb->tfb_tcp_mtu_chg(tp);
3361 }
3362 if (tcp_output(tp) < 0)
3363 return (NULL);
3364 else
3365 return (inp);
3366 }
3367
3368 #ifdef INET
3369 /*
3370 * Look-up the routing entry to the peer of this inpcb. If no route
3371 * is found and it cannot be allocated, then return 0. This routine
3372 * is called by TCP routines that access the rmx structure and by
3373 * tcp_mss_update to get the peer/interface MTU.
3374 */
3375 uint32_t
tcp_maxmtu(struct in_conninfo * inc,struct tcp_ifcap * cap)3376 tcp_maxmtu(struct in_conninfo *inc, struct tcp_ifcap *cap)
3377 {
3378 struct nhop_object *nh;
3379 struct ifnet *ifp;
3380 uint32_t maxmtu = 0;
3381
3382 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
3383
3384 if (inc->inc_faddr.s_addr != INADDR_ANY) {
3385 nh = fib4_lookup(inc->inc_fibnum, inc->inc_faddr, 0, NHR_NONE, 0);
3386 if (nh == NULL)
3387 return (0);
3388
3389 ifp = nh->nh_ifp;
3390 maxmtu = nh->nh_mtu;
3391
3392 /* Report additional interface capabilities. */
3393 if (cap != NULL) {
3394 if (ifp->if_capenable & IFCAP_TSO4 &&
3395 ifp->if_hwassist & CSUM_TSO) {
3396 cap->ifcap |= CSUM_TSO;
3397 cap->tsomax = ifp->if_hw_tsomax;
3398 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
3399 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
3400 /* XXXKIB IFCAP2_IPSEC_OFFLOAD_TSO */
3401 cap->ipsec_tso = (ifp->if_capenable2 &
3402 IFCAP2_BIT(IFCAP2_IPSEC_OFFLOAD)) != 0;
3403 }
3404 }
3405 }
3406 return (maxmtu);
3407 }
3408 #endif /* INET */
3409
3410 #ifdef INET6
3411 uint32_t
tcp_maxmtu6(struct in_conninfo * inc,struct tcp_ifcap * cap)3412 tcp_maxmtu6(struct in_conninfo *inc, struct tcp_ifcap *cap)
3413 {
3414 struct nhop_object *nh;
3415 struct in6_addr dst6;
3416 uint32_t scopeid;
3417 struct ifnet *ifp;
3418 uint32_t maxmtu = 0;
3419
3420 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
3421
3422 if (inc->inc_flags & INC_IPV6MINMTU)
3423 return (IPV6_MMTU);
3424
3425 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
3426 in6_splitscope(&inc->inc6_faddr, &dst6, &scopeid);
3427 nh = fib6_lookup(inc->inc_fibnum, &dst6, scopeid, NHR_NONE, 0);
3428 if (nh == NULL)
3429 return (0);
3430
3431 ifp = nh->nh_ifp;
3432 maxmtu = nh->nh_mtu;
3433
3434 /* Report additional interface capabilities. */
3435 if (cap != NULL) {
3436 if (ifp->if_capenable & IFCAP_TSO6 &&
3437 ifp->if_hwassist & CSUM_TSO) {
3438 cap->ifcap |= CSUM_TSO;
3439 cap->tsomax = ifp->if_hw_tsomax;
3440 cap->tsomaxsegcount = ifp->if_hw_tsomaxsegcount;
3441 cap->tsomaxsegsize = ifp->if_hw_tsomaxsegsize;
3442 cap->ipsec_tso = false; /* XXXKIB */
3443 }
3444 }
3445 }
3446
3447 return (maxmtu);
3448 }
3449
3450 /*
3451 * Handle setsockopt(IPV6_USE_MIN_MTU) by a TCP stack.
3452 *
3453 * XXXGL: we are updating inpcb here with INC_IPV6MINMTU flag.
3454 * The right place to do that is ip6_setpktopt() that has just been
3455 * executed. By the way it just filled ip6po_minmtu for us.
3456 */
3457 void
tcp6_use_min_mtu(struct tcpcb * tp)3458 tcp6_use_min_mtu(struct tcpcb *tp)
3459 {
3460 struct inpcb *inp = tptoinpcb(tp);
3461
3462 INP_WLOCK_ASSERT(inp);
3463 /*
3464 * In case of the IPV6_USE_MIN_MTU socket
3465 * option, the INC_IPV6MINMTU flag to announce
3466 * a corresponding MSS during the initial
3467 * handshake. If the TCP connection is not in
3468 * the front states, just reduce the MSS being
3469 * used. This avoids the sending of TCP
3470 * segments which will be fragmented at the
3471 * IPv6 layer.
3472 */
3473 inp->inp_inc.inc_flags |= INC_IPV6MINMTU;
3474 if ((tp->t_state >= TCPS_SYN_SENT) &&
3475 (inp->inp_inc.inc_flags & INC_ISIPV6)) {
3476 struct ip6_pktopts *opt;
3477
3478 opt = inp->in6p_outputopts;
3479 if (opt != NULL && opt->ip6po_minmtu == IP6PO_MINMTU_ALL &&
3480 tp->t_maxseg > TCP6_MSS) {
3481 tp->t_maxseg = TCP6_MSS;
3482 if (tp->t_maxseg < V_tcp_mssdflt) {
3483 /*
3484 * The MSS is so small we should not process incoming
3485 * SACK's since we are subject to attack in such a
3486 * case.
3487 */
3488 tp->t_flags2 |= TF2_PROC_SACK_PROHIBIT;
3489 } else {
3490 tp->t_flags2 &= ~TF2_PROC_SACK_PROHIBIT;
3491 }
3492 }
3493 }
3494 }
3495 #endif /* INET6 */
3496
3497 /*
3498 * Calculate effective SMSS per RFC5681 definition for a given TCP
3499 * connection at its current state, taking into account SACK and etc.
3500 */
3501 u_int
tcp_maxseg(const struct tcpcb * tp)3502 tcp_maxseg(const struct tcpcb *tp)
3503 {
3504 u_int optlen;
3505
3506 if (tp->t_flags & TF_NOOPT)
3507 return (tp->t_maxseg);
3508
3509 /*
3510 * Here we have a simplified code from tcp_addoptions(),
3511 * without a proper loop, and having most of paddings hardcoded.
3512 * We might make mistakes with padding here in some edge cases,
3513 * but this is harmless, since result of tcp_maxseg() is used
3514 * only in cwnd and ssthresh estimations.
3515 */
3516 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
3517 if (tp->t_flags & TF_RCVD_TSTMP)
3518 optlen = TCPOLEN_TSTAMP_APPA;
3519 else
3520 optlen = 0;
3521 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3522 if (tp->t_flags & TF_SIGNATURE)
3523 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3524 #endif
3525 if ((tp->t_flags & TF_SACK_PERMIT) && tp->rcv_numsacks > 0) {
3526 optlen += TCPOLEN_SACKHDR;
3527 optlen += tp->rcv_numsacks * TCPOLEN_SACK;
3528 optlen = PADTCPOLEN(optlen);
3529 }
3530 } else {
3531 if (tp->t_flags & TF_REQ_TSTMP)
3532 optlen = TCPOLEN_TSTAMP_APPA;
3533 else
3534 optlen = PADTCPOLEN(TCPOLEN_MAXSEG);
3535 if (tp->t_flags & TF_REQ_SCALE)
3536 optlen += PADTCPOLEN(TCPOLEN_WINDOW);
3537 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3538 if (tp->t_flags & TF_SIGNATURE)
3539 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3540 #endif
3541 if (tp->t_flags & TF_SACK_PERMIT)
3542 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED);
3543 }
3544 optlen = min(optlen, TCP_MAXOLEN);
3545 return (tp->t_maxseg - optlen);
3546 }
3547
3548
3549 u_int
tcp_fixed_maxseg(const struct tcpcb * tp)3550 tcp_fixed_maxseg(const struct tcpcb *tp)
3551 {
3552 int optlen;
3553
3554 if (tp->t_flags & TF_NOOPT)
3555 return (tp->t_maxseg);
3556
3557 /*
3558 * Here we have a simplified code from tcp_addoptions(),
3559 * without a proper loop, and having most of paddings hardcoded.
3560 * We only consider fixed options that we would send every
3561 * time I.e. SACK is not considered. This is important
3562 * for cc modules to figure out what the modulo of the
3563 * cwnd should be.
3564 */
3565 if (TCPS_HAVEESTABLISHED(tp->t_state)) {
3566 if (tp->t_flags & TF_RCVD_TSTMP)
3567 optlen = TCPOLEN_TSTAMP_APPA;
3568 else
3569 optlen = 0;
3570 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3571 if (tp->t_flags & TF_SIGNATURE)
3572 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3573 #endif
3574 } else {
3575 if (tp->t_flags & TF_REQ_TSTMP)
3576 optlen = TCPOLEN_TSTAMP_APPA;
3577 else
3578 optlen = PADTCPOLEN(TCPOLEN_MAXSEG);
3579 if (tp->t_flags & TF_REQ_SCALE)
3580 optlen += PADTCPOLEN(TCPOLEN_WINDOW);
3581 #if defined(IPSEC_SUPPORT) || defined(TCP_SIGNATURE)
3582 if (tp->t_flags & TF_SIGNATURE)
3583 optlen += PADTCPOLEN(TCPOLEN_SIGNATURE);
3584 #endif
3585 if (tp->t_flags & TF_SACK_PERMIT)
3586 optlen += PADTCPOLEN(TCPOLEN_SACK_PERMITTED);
3587 }
3588 optlen = min(optlen, TCP_MAXOLEN);
3589 return (tp->t_maxseg - optlen);
3590 }
3591
3592
3593
3594 static int
sysctl_drop(SYSCTL_HANDLER_ARGS)3595 sysctl_drop(SYSCTL_HANDLER_ARGS)
3596 {
3597 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
3598 struct sockaddr_storage addrs[2];
3599 struct inpcb *inp;
3600 struct tcpcb *tp;
3601 #ifdef INET
3602 struct sockaddr_in *fin = NULL, *lin = NULL;
3603 #endif
3604 struct epoch_tracker et;
3605 #ifdef INET6
3606 struct sockaddr_in6 *fin6, *lin6;
3607 #endif
3608 int error;
3609
3610 inp = NULL;
3611 #ifdef INET6
3612 fin6 = lin6 = NULL;
3613 #endif
3614 error = 0;
3615
3616 if (req->oldptr != NULL || req->oldlen != 0)
3617 return (EINVAL);
3618 if (req->newptr == NULL)
3619 return (EPERM);
3620 if (req->newlen < sizeof(addrs))
3621 return (ENOMEM);
3622 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
3623 if (error)
3624 return (error);
3625
3626 switch (addrs[0].ss_family) {
3627 #ifdef INET6
3628 case AF_INET6:
3629 fin6 = (struct sockaddr_in6 *)&addrs[0];
3630 lin6 = (struct sockaddr_in6 *)&addrs[1];
3631 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
3632 lin6->sin6_len != sizeof(struct sockaddr_in6))
3633 return (EINVAL);
3634 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
3635 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
3636 return (EINVAL);
3637 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
3638 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
3639 #ifdef INET
3640 fin = (struct sockaddr_in *)&addrs[0];
3641 lin = (struct sockaddr_in *)&addrs[1];
3642 #endif
3643 break;
3644 }
3645 error = sa6_embedscope(fin6, V_ip6_use_defzone);
3646 if (error)
3647 return (error);
3648 error = sa6_embedscope(lin6, V_ip6_use_defzone);
3649 if (error)
3650 return (error);
3651 break;
3652 #endif
3653 #ifdef INET
3654 case AF_INET:
3655 fin = (struct sockaddr_in *)&addrs[0];
3656 lin = (struct sockaddr_in *)&addrs[1];
3657 if (fin->sin_len != sizeof(struct sockaddr_in) ||
3658 lin->sin_len != sizeof(struct sockaddr_in))
3659 return (EINVAL);
3660 break;
3661 #endif
3662 default:
3663 return (EINVAL);
3664 }
3665 NET_EPOCH_ENTER(et);
3666 switch (addrs[0].ss_family) {
3667 #ifdef INET6
3668 case AF_INET6:
3669 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
3670 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
3671 INPLOOKUP_WLOCKPCB, NULL);
3672 break;
3673 #endif
3674 #ifdef INET
3675 case AF_INET:
3676 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
3677 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
3678 break;
3679 #endif
3680 }
3681 if (inp != NULL) {
3682 if (!SOLISTENING(inp->inp_socket)) {
3683 tp = intotcpcb(inp);
3684 tp = tcp_drop(tp, ECONNABORTED);
3685 if (tp != NULL)
3686 INP_WUNLOCK(inp);
3687 } else
3688 INP_WUNLOCK(inp);
3689 } else
3690 error = ESRCH;
3691 NET_EPOCH_EXIT(et);
3692 return (error);
3693 }
3694
3695 SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
3696 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3697 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_drop, "",
3698 "Drop TCP connection");
3699
3700 static int
tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS)3701 tcp_sysctl_setsockopt(SYSCTL_HANDLER_ARGS)
3702 {
3703 return (sysctl_setsockopt(oidp, arg1, arg2, req, &V_tcbinfo,
3704 &tcp_ctloutput_set));
3705 }
3706
3707 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, setsockopt,
3708 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3709 CTLFLAG_MPSAFE, NULL, 0, tcp_sysctl_setsockopt, "",
3710 "Set socket option for TCP endpoint");
3711
3712 #ifdef KERN_TLS
3713 static int
sysctl_switch_tls(SYSCTL_HANDLER_ARGS)3714 sysctl_switch_tls(SYSCTL_HANDLER_ARGS)
3715 {
3716 /* addrs[0] is a foreign socket, addrs[1] is a local one. */
3717 struct sockaddr_storage addrs[2];
3718 struct inpcb *inp;
3719 #ifdef INET
3720 struct sockaddr_in *fin = NULL, *lin = NULL;
3721 #endif
3722 struct epoch_tracker et;
3723 #ifdef INET6
3724 struct sockaddr_in6 *fin6, *lin6;
3725 #endif
3726 int error;
3727
3728 inp = NULL;
3729 #ifdef INET6
3730 fin6 = lin6 = NULL;
3731 #endif
3732 error = 0;
3733
3734 if (req->oldptr != NULL || req->oldlen != 0)
3735 return (EINVAL);
3736 if (req->newptr == NULL)
3737 return (EPERM);
3738 if (req->newlen < sizeof(addrs))
3739 return (ENOMEM);
3740 error = SYSCTL_IN(req, &addrs, sizeof(addrs));
3741 if (error)
3742 return (error);
3743
3744 switch (addrs[0].ss_family) {
3745 #ifdef INET6
3746 case AF_INET6:
3747 fin6 = (struct sockaddr_in6 *)&addrs[0];
3748 lin6 = (struct sockaddr_in6 *)&addrs[1];
3749 if (fin6->sin6_len != sizeof(struct sockaddr_in6) ||
3750 lin6->sin6_len != sizeof(struct sockaddr_in6))
3751 return (EINVAL);
3752 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
3753 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
3754 return (EINVAL);
3755 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]);
3756 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]);
3757 #ifdef INET
3758 fin = (struct sockaddr_in *)&addrs[0];
3759 lin = (struct sockaddr_in *)&addrs[1];
3760 #endif
3761 break;
3762 }
3763 error = sa6_embedscope(fin6, V_ip6_use_defzone);
3764 if (error)
3765 return (error);
3766 error = sa6_embedscope(lin6, V_ip6_use_defzone);
3767 if (error)
3768 return (error);
3769 break;
3770 #endif
3771 #ifdef INET
3772 case AF_INET:
3773 fin = (struct sockaddr_in *)&addrs[0];
3774 lin = (struct sockaddr_in *)&addrs[1];
3775 if (fin->sin_len != sizeof(struct sockaddr_in) ||
3776 lin->sin_len != sizeof(struct sockaddr_in))
3777 return (EINVAL);
3778 break;
3779 #endif
3780 default:
3781 return (EINVAL);
3782 }
3783 NET_EPOCH_ENTER(et);
3784 switch (addrs[0].ss_family) {
3785 #ifdef INET6
3786 case AF_INET6:
3787 inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
3788 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
3789 INPLOOKUP_WLOCKPCB, NULL);
3790 break;
3791 #endif
3792 #ifdef INET
3793 case AF_INET:
3794 inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
3795 lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
3796 break;
3797 #endif
3798 }
3799 NET_EPOCH_EXIT(et);
3800 if (inp != NULL) {
3801 struct socket *so;
3802
3803 so = inp->inp_socket;
3804 soref(so);
3805 error = ktls_set_tx_mode(so,
3806 arg2 == 0 ? TCP_TLS_MODE_SW : TCP_TLS_MODE_IFNET);
3807 INP_WUNLOCK(inp);
3808 sorele(so);
3809 } else
3810 error = ESRCH;
3811 return (error);
3812 }
3813
3814 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_sw_tls,
3815 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3816 CTLFLAG_NEEDGIANT, NULL, 0, sysctl_switch_tls, "",
3817 "Switch TCP connection to SW TLS");
3818 SYSCTL_PROC(_net_inet_tcp, OID_AUTO, switch_to_ifnet_tls,
3819 CTLFLAG_VNET | CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP |
3820 CTLFLAG_NEEDGIANT, NULL, 1, sysctl_switch_tls, "",
3821 "Switch TCP connection to ifnet TLS");
3822 #endif
3823
3824 /*
3825 * Generate a standardized TCP log line for use throughout the
3826 * tcp subsystem. Memory allocation is done with M_NOWAIT to
3827 * allow use in the interrupt context.
3828 *
3829 * NB: The caller MUST free(s, M_TCPLOG) the returned string.
3830 * NB: The function may return NULL if memory allocation failed.
3831 *
3832 * Due to header inclusion and ordering limitations the struct ip
3833 * and ip6_hdr pointers have to be passed as void pointers.
3834 */
3835 char *
tcp_log_vain(struct in_conninfo * inc,struct tcphdr * th,const void * ip4hdr,const void * ip6hdr)3836 tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr,
3837 const void *ip6hdr)
3838 {
3839
3840 /* Is logging enabled? */
3841 if (V_tcp_log_in_vain == 0)
3842 return (NULL);
3843
3844 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3845 }
3846
3847 char *
tcp_log_addrs(struct in_conninfo * inc,struct tcphdr * th,const void * ip4hdr,const void * ip6hdr)3848 tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr,
3849 const void *ip6hdr)
3850 {
3851
3852 /* Is logging enabled? */
3853 if (tcp_log_debug == 0)
3854 return (NULL);
3855
3856 return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
3857 }
3858
3859 static char *
tcp_log_addr(struct in_conninfo * inc,struct tcphdr * th,const void * ip4hdr,const void * ip6hdr)3860 tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, const void *ip4hdr,
3861 const void *ip6hdr)
3862 {
3863 char *s, *sp;
3864 size_t size;
3865 #ifdef INET
3866 const struct ip *ip = (const struct ip *)ip4hdr;
3867 #endif
3868 #ifdef INET6
3869 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)ip6hdr;
3870 #endif /* INET6 */
3871
3872 /*
3873 * The log line looks like this:
3874 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
3875 */
3876 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
3877 sizeof(PRINT_TH_FLAGS) + 1 +
3878 #ifdef INET6
3879 2 * INET6_ADDRSTRLEN;
3880 #else
3881 2 * INET_ADDRSTRLEN;
3882 #endif /* INET6 */
3883
3884 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT);
3885 if (s == NULL)
3886 return (NULL);
3887
3888 strcat(s, "TCP: [");
3889 sp = s + strlen(s);
3890
3891 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
3892 inet_ntoa_r(inc->inc_faddr, sp);
3893 sp = s + strlen(s);
3894 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3895 sp = s + strlen(s);
3896 inet_ntoa_r(inc->inc_laddr, sp);
3897 sp = s + strlen(s);
3898 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3899 #ifdef INET6
3900 } else if (inc) {
3901 ip6_sprintf(sp, &inc->inc6_faddr);
3902 sp = s + strlen(s);
3903 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
3904 sp = s + strlen(s);
3905 ip6_sprintf(sp, &inc->inc6_laddr);
3906 sp = s + strlen(s);
3907 sprintf(sp, "]:%i", ntohs(inc->inc_lport));
3908 } else if (ip6 && th) {
3909 ip6_sprintf(sp, &ip6->ip6_src);
3910 sp = s + strlen(s);
3911 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3912 sp = s + strlen(s);
3913 ip6_sprintf(sp, &ip6->ip6_dst);
3914 sp = s + strlen(s);
3915 sprintf(sp, "]:%i", ntohs(th->th_dport));
3916 #endif /* INET6 */
3917 #ifdef INET
3918 } else if (ip && th) {
3919 inet_ntoa_r(ip->ip_src, sp);
3920 sp = s + strlen(s);
3921 sprintf(sp, "]:%i to [", ntohs(th->th_sport));
3922 sp = s + strlen(s);
3923 inet_ntoa_r(ip->ip_dst, sp);
3924 sp = s + strlen(s);
3925 sprintf(sp, "]:%i", ntohs(th->th_dport));
3926 #endif /* INET */
3927 } else {
3928 free(s, M_TCPLOG);
3929 return (NULL);
3930 }
3931 sp = s + strlen(s);
3932 if (th)
3933 sprintf(sp, " tcpflags 0x%b", tcp_get_flags(th), PRINT_TH_FLAGS);
3934 if (*(s + size - 1) != '\0')
3935 panic("%s: string too long", __func__);
3936 return (s);
3937 }
3938
3939 /*
3940 * A subroutine which makes it easy to track TCP state changes with DTrace.
3941 * This function shouldn't be called for t_state initializations that don't
3942 * correspond to actual TCP state transitions.
3943 */
3944 void
tcp_state_change(struct tcpcb * tp,int newstate)3945 tcp_state_change(struct tcpcb *tp, int newstate)
3946 {
3947 #if defined(KDTRACE_HOOKS)
3948 int pstate = tp->t_state;
3949 #endif
3950
3951 TCPSTATES_DEC(tp->t_state);
3952 TCPSTATES_INC(newstate);
3953 tp->t_state = newstate;
3954 TCP_PROBE6(state__change, NULL, tp, NULL, tp, NULL, pstate);
3955 }
3956
3957 /*
3958 * Create an external-format (``xtcpcb'') structure using the information in
3959 * the kernel-format tcpcb structure pointed to by tp. This is done to
3960 * reduce the spew of irrelevant information over this interface, to isolate
3961 * user code from changes in the kernel structure, and potentially to provide
3962 * information-hiding if we decide that some of this information should be
3963 * hidden from users.
3964 */
3965 void
tcp_inptoxtp(const struct inpcb * inp,struct xtcpcb * xt)3966 tcp_inptoxtp(const struct inpcb *inp, struct xtcpcb *xt)
3967 {
3968 struct tcpcb *tp = intotcpcb(inp);
3969 sbintime_t now;
3970
3971 bzero(xt, sizeof(*xt));
3972 xt->t_state = tp->t_state;
3973 xt->t_logstate = tcp_get_bblog_state(tp);
3974 xt->t_flags = tp->t_flags;
3975 xt->t_sndzerowin = tp->t_sndzerowin;
3976 xt->t_sndrexmitpack = tp->t_sndrexmitpack;
3977 xt->t_rcvoopack = tp->t_rcvoopack;
3978 xt->t_rcv_wnd = tp->rcv_wnd;
3979 xt->t_snd_wnd = tp->snd_wnd;
3980 xt->t_snd_cwnd = tp->snd_cwnd;
3981 xt->t_snd_ssthresh = tp->snd_ssthresh;
3982 xt->t_dsack_bytes = tp->t_dsack_bytes;
3983 xt->t_dsack_tlp_bytes = tp->t_dsack_tlp_bytes;
3984 xt->t_dsack_pack = tp->t_dsack_pack;
3985 xt->t_maxseg = tp->t_maxseg;
3986 xt->xt_ecn = (tp->t_flags2 & TF2_ECN_PERMIT) ? 1 : 0 +
3987 (tp->t_flags2 & TF2_ACE_PERMIT) ? 2 : 0;
3988
3989 now = getsbinuptime();
3990 #define COPYTIMER(which,where) do { \
3991 if (tp->t_timers[which] != SBT_MAX) \
3992 xt->where = (tp->t_timers[which] - now) / SBT_1MS; \
3993 else \
3994 xt->where = 0; \
3995 } while (0)
3996 COPYTIMER(TT_DELACK, tt_delack);
3997 COPYTIMER(TT_REXMT, tt_rexmt);
3998 COPYTIMER(TT_PERSIST, tt_persist);
3999 COPYTIMER(TT_KEEP, tt_keep);
4000 COPYTIMER(TT_2MSL, tt_2msl);
4001 #undef COPYTIMER
4002 xt->t_rcvtime = 1000 * (ticks - tp->t_rcvtime) / hz;
4003
4004 xt->xt_encaps_port = tp->t_port;
4005 bcopy(tp->t_fb->tfb_tcp_block_name, xt->xt_stack,
4006 TCP_FUNCTION_NAME_LEN_MAX);
4007 bcopy(CC_ALGO(tp)->name, xt->xt_cc, TCP_CA_NAME_MAX);
4008 #ifdef TCP_BLACKBOX
4009 (void)tcp_log_get_id(tp, xt->xt_logid);
4010 #endif
4011
4012 xt->xt_len = sizeof(struct xtcpcb);
4013 in_pcbtoxinpcb(inp, &xt->xt_inp);
4014 }
4015
4016 void
tcp_log_end_status(struct tcpcb * tp,uint8_t status)4017 tcp_log_end_status(struct tcpcb *tp, uint8_t status)
4018 {
4019 uint32_t bit, i;
4020
4021 if ((tp == NULL) ||
4022 (status > TCP_EI_STATUS_MAX_VALUE) ||
4023 (status == 0)) {
4024 /* Invalid */
4025 return;
4026 }
4027 if (status > (sizeof(uint32_t) * 8)) {
4028 /* Should this be a KASSERT? */
4029 return;
4030 }
4031 bit = 1U << (status - 1);
4032 if (bit & tp->t_end_info_status) {
4033 /* already logged */
4034 return;
4035 }
4036 for (i = 0; i < TCP_END_BYTE_INFO; i++) {
4037 if (tp->t_end_info_bytes[i] == TCP_EI_EMPTY_SLOT) {
4038 tp->t_end_info_bytes[i] = status;
4039 tp->t_end_info_status |= bit;
4040 break;
4041 }
4042 }
4043 }
4044
4045 int
tcp_can_enable_pacing(void)4046 tcp_can_enable_pacing(void)
4047 {
4048
4049 if ((tcp_pacing_limit == -1) ||
4050 (tcp_pacing_limit > number_of_tcp_connections_pacing)) {
4051 atomic_fetchadd_int(&number_of_tcp_connections_pacing, 1);
4052 shadow_num_connections = number_of_tcp_connections_pacing;
4053 return (1);
4054 } else {
4055 counter_u64_add(tcp_pacing_failures, 1);
4056 return (0);
4057 }
4058 }
4059
4060 int
tcp_incr_dgp_pacing_cnt(void)4061 tcp_incr_dgp_pacing_cnt(void)
4062 {
4063 if ((tcp_dgp_limit == -1) ||
4064 (tcp_dgp_limit > number_of_dgp_connections)) {
4065 atomic_fetchadd_int(&number_of_dgp_connections, 1);
4066 shadow_tcp_pacing_dgp = number_of_dgp_connections;
4067 return (1);
4068 } else {
4069 counter_u64_add(tcp_dgp_failures, 1);
4070 return (0);
4071 }
4072 }
4073
4074 static uint8_t tcp_dgp_warning = 0;
4075
4076 void
tcp_dec_dgp_pacing_cnt(void)4077 tcp_dec_dgp_pacing_cnt(void)
4078 {
4079 uint32_t ret;
4080
4081 ret = atomic_fetchadd_int(&number_of_dgp_connections, -1);
4082 shadow_tcp_pacing_dgp = number_of_dgp_connections;
4083 KASSERT(ret != 0, ("number_of_dgp_connections -1 would cause wrap?"));
4084 if (ret == 0) {
4085 if (tcp_dgp_limit != -1) {
4086 printf("Warning all DGP is now disabled, count decrements invalidly!\n");
4087 tcp_dgp_limit = 0;
4088 tcp_dgp_warning = 1;
4089 } else if (tcp_dgp_warning == 0) {
4090 printf("Warning DGP pacing is invalid, invalid decrement\n");
4091 tcp_dgp_warning = 1;
4092 }
4093 }
4094
4095 }
4096
4097 static uint8_t tcp_pacing_warning = 0;
4098
4099 void
tcp_decrement_paced_conn(void)4100 tcp_decrement_paced_conn(void)
4101 {
4102 uint32_t ret;
4103
4104 ret = atomic_fetchadd_int(&number_of_tcp_connections_pacing, -1);
4105 shadow_num_connections = number_of_tcp_connections_pacing;
4106 KASSERT(ret != 0, ("tcp_paced_connection_exits -1 would cause wrap?"));
4107 if (ret == 0) {
4108 if (tcp_pacing_limit != -1) {
4109 printf("Warning all pacing is now disabled, count decrements invalidly!\n");
4110 tcp_pacing_limit = 0;
4111 } else if (tcp_pacing_warning == 0) {
4112 printf("Warning pacing count is invalid, invalid decrement\n");
4113 tcp_pacing_warning = 1;
4114 }
4115 }
4116 }
4117
4118 static void
tcp_default_switch_failed(struct tcpcb * tp)4119 tcp_default_switch_failed(struct tcpcb *tp)
4120 {
4121 /*
4122 * If a switch fails we only need to
4123 * care about two things:
4124 * a) The t_flags2
4125 * and
4126 * b) The timer granularity.
4127 * Timeouts, at least for now, don't use the
4128 * old callout system in the other stacks so
4129 * those are hopefully safe.
4130 */
4131 tcp_lro_features_off(tp);
4132 tcp_change_time_units(tp, TCP_TMR_GRANULARITY_TICKS);
4133 }
4134
4135 #ifdef TCP_ACCOUNTING
4136 int
tcp_do_ack_accounting(struct tcpcb * tp,struct tcphdr * th,struct tcpopt * to,uint32_t tiwin,int mss)4137 tcp_do_ack_accounting(struct tcpcb *tp, struct tcphdr *th, struct tcpopt *to, uint32_t tiwin, int mss)
4138 {
4139 if (SEQ_LT(th->th_ack, tp->snd_una)) {
4140 /* Do we have a SACK? */
4141 if (to->to_flags & TOF_SACK) {
4142 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4143 tp->tcp_cnt_counters[ACK_SACK]++;
4144 }
4145 return (ACK_SACK);
4146 } else {
4147 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4148 tp->tcp_cnt_counters[ACK_BEHIND]++;
4149 }
4150 return (ACK_BEHIND);
4151 }
4152 } else if (th->th_ack == tp->snd_una) {
4153 /* Do we have a SACK? */
4154 if (to->to_flags & TOF_SACK) {
4155 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4156 tp->tcp_cnt_counters[ACK_SACK]++;
4157 }
4158 return (ACK_SACK);
4159 } else if (tiwin != tp->snd_wnd) {
4160 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4161 tp->tcp_cnt_counters[ACK_RWND]++;
4162 }
4163 return (ACK_RWND);
4164 } else {
4165 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4166 tp->tcp_cnt_counters[ACK_DUPACK]++;
4167 }
4168 return (ACK_DUPACK);
4169 }
4170 } else {
4171 if (!SEQ_GT(th->th_ack, tp->snd_max)) {
4172 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4173 tp->tcp_cnt_counters[CNT_OF_ACKS_IN] += (((th->th_ack - tp->snd_una) + mss - 1)/mss);
4174 }
4175 }
4176 if (to->to_flags & TOF_SACK) {
4177 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4178 tp->tcp_cnt_counters[ACK_CUMACK_SACK]++;
4179 }
4180 return (ACK_CUMACK_SACK);
4181 } else {
4182 if (tp->t_flags2 & TF2_TCP_ACCOUNTING) {
4183 tp->tcp_cnt_counters[ACK_CUMACK]++;
4184 }
4185 return (ACK_CUMACK);
4186 }
4187 }
4188 }
4189 #endif
4190
4191 void
tcp_change_time_units(struct tcpcb * tp,int granularity)4192 tcp_change_time_units(struct tcpcb *tp, int granularity)
4193 {
4194 if (tp->t_tmr_granularity == granularity) {
4195 /* We are there */
4196 return;
4197 }
4198 if (granularity == TCP_TMR_GRANULARITY_USEC) {
4199 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS),
4200 ("Granularity is not TICKS its %u in tp:%p",
4201 tp->t_tmr_granularity, tp));
4202 tp->t_rttlow = TICKS_2_USEC(tp->t_rttlow);
4203 if (tp->t_srtt > 1) {
4204 uint32_t val, frac;
4205
4206 val = tp->t_srtt >> TCP_RTT_SHIFT;
4207 frac = tp->t_srtt & 0x1f;
4208 tp->t_srtt = TICKS_2_USEC(val);
4209 /*
4210 * frac is the fractional part of the srtt (if any)
4211 * but its in ticks and every bit represents
4212 * 1/32nd of a hz.
4213 */
4214 if (frac) {
4215 if (hz == 1000) {
4216 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
4217 } else {
4218 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
4219 }
4220 tp->t_srtt += frac;
4221 }
4222 }
4223 if (tp->t_rttvar) {
4224 uint32_t val, frac;
4225
4226 val = tp->t_rttvar >> TCP_RTTVAR_SHIFT;
4227 frac = tp->t_rttvar & 0x1f;
4228 tp->t_rttvar = TICKS_2_USEC(val);
4229 /*
4230 * frac is the fractional part of the srtt (if any)
4231 * but its in ticks and every bit represents
4232 * 1/32nd of a hz.
4233 */
4234 if (frac) {
4235 if (hz == 1000) {
4236 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_MSEC) / (uint64_t)TCP_RTT_SCALE);
4237 } else {
4238 frac = (((uint64_t)frac * (uint64_t)HPTS_USEC_IN_SEC) / ((uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE));
4239 }
4240 tp->t_rttvar += frac;
4241 }
4242 }
4243 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_USEC;
4244 } else if (granularity == TCP_TMR_GRANULARITY_TICKS) {
4245 /* Convert back to ticks, with */
4246 KASSERT((tp->t_tmr_granularity == TCP_TMR_GRANULARITY_USEC),
4247 ("Granularity is not USEC its %u in tp:%p",
4248 tp->t_tmr_granularity, tp));
4249 if (tp->t_srtt > 1) {
4250 uint32_t val, frac;
4251
4252 val = USEC_2_TICKS(tp->t_srtt);
4253 frac = tp->t_srtt % (HPTS_USEC_IN_SEC / hz);
4254 tp->t_srtt = val << TCP_RTT_SHIFT;
4255 /*
4256 * frac is the fractional part here is left
4257 * over from converting to hz and shifting.
4258 * We need to convert this to the 5 bit
4259 * remainder.
4260 */
4261 if (frac) {
4262 if (hz == 1000) {
4263 frac = (((uint64_t)frac * (uint64_t)TCP_RTT_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
4264 } else {
4265 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTT_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
4266 }
4267 tp->t_srtt += frac;
4268 }
4269 }
4270 if (tp->t_rttvar) {
4271 uint32_t val, frac;
4272
4273 val = USEC_2_TICKS(tp->t_rttvar);
4274 frac = tp->t_rttvar % (HPTS_USEC_IN_SEC / hz);
4275 tp->t_rttvar = val << TCP_RTTVAR_SHIFT;
4276 /*
4277 * frac is the fractional part here is left
4278 * over from converting to hz and shifting.
4279 * We need to convert this to the 4 bit
4280 * remainder.
4281 */
4282 if (frac) {
4283 if (hz == 1000) {
4284 frac = (((uint64_t)frac * (uint64_t)TCP_RTTVAR_SCALE) / (uint64_t)HPTS_USEC_IN_MSEC);
4285 } else {
4286 frac = (((uint64_t)frac * (uint64_t)(hz) * (uint64_t)TCP_RTTVAR_SCALE) /(uint64_t)HPTS_USEC_IN_SEC);
4287 }
4288 tp->t_rttvar += frac;
4289 }
4290 }
4291 tp->t_rttlow = USEC_2_TICKS(tp->t_rttlow);
4292 tp->t_tmr_granularity = TCP_TMR_GRANULARITY_TICKS;
4293 }
4294 #ifdef INVARIANTS
4295 else {
4296 panic("Unknown granularity:%d tp:%p",
4297 granularity, tp);
4298 }
4299 #endif
4300 }
4301
4302 void
tcp_handle_orphaned_packets(struct tcpcb * tp)4303 tcp_handle_orphaned_packets(struct tcpcb *tp)
4304 {
4305 struct mbuf *save, *m, *prev;
4306 /*
4307 * Called when a stack switch is occuring from the fini()
4308 * of the old stack. We assue the init() as already been
4309 * run of the new stack and it has set the t_flags2 to
4310 * what it supports. This function will then deal with any
4311 * differences i.e. cleanup packets that maybe queued that
4312 * the newstack does not support.
4313 */
4314
4315 if (tp->t_flags2 & TF2_MBUF_L_ACKS)
4316 return;
4317 if ((tp->t_flags2 & TF2_SUPPORTS_MBUFQ) == 0 &&
4318 !STAILQ_EMPTY(&tp->t_inqueue)) {
4319 /*
4320 * It is unsafe to process the packets since a
4321 * reset may be lurking in them (its rare but it
4322 * can occur). If we were to find a RST, then we
4323 * would end up dropping the connection and the
4324 * INP lock, so when we return the caller (tcp_usrreq)
4325 * will blow up when it trys to unlock the inp.
4326 * This new stack does not do any fancy LRO features
4327 * so all we can do is toss the packets.
4328 */
4329 m = STAILQ_FIRST(&tp->t_inqueue);
4330 STAILQ_INIT(&tp->t_inqueue);
4331 STAILQ_FOREACH_FROM_SAFE(m, &tp->t_inqueue, m_stailqpkt, save)
4332 m_freem(m);
4333 } else {
4334 /*
4335 * Here we have a stack that does mbuf queuing but
4336 * does not support compressed ack's. We must
4337 * walk all the mbufs and discard any compressed acks.
4338 */
4339 STAILQ_FOREACH_SAFE(m, &tp->t_inqueue, m_stailqpkt, save) {
4340 if (m->m_flags & M_ACKCMP) {
4341 if (m == STAILQ_FIRST(&tp->t_inqueue))
4342 STAILQ_REMOVE_HEAD(&tp->t_inqueue,
4343 m_stailqpkt);
4344 else
4345 STAILQ_REMOVE_AFTER(&tp->t_inqueue,
4346 prev, m_stailqpkt);
4347 m_freem(m);
4348 } else
4349 prev = m;
4350 }
4351 }
4352 }
4353
4354 #ifdef TCP_REQUEST_TRK
4355 uint32_t
tcp_estimate_tls_overhead(struct socket * so,uint64_t tls_usr_bytes)4356 tcp_estimate_tls_overhead(struct socket *so, uint64_t tls_usr_bytes)
4357 {
4358 #ifdef KERN_TLS
4359 struct ktls_session *tls;
4360 uint32_t rec_oh, records;
4361
4362 tls = so->so_snd.sb_tls_info;
4363 if (tls == NULL)
4364 return (0);
4365
4366 rec_oh = tls->params.tls_hlen + tls->params.tls_tlen;
4367 records = ((tls_usr_bytes + tls->params.max_frame_len - 1)/tls->params.max_frame_len);
4368 return (records * rec_oh);
4369 #else
4370 return (0);
4371 #endif
4372 }
4373
4374 extern uint32_t tcp_stale_entry_time;
4375 uint32_t tcp_stale_entry_time = 250000;
4376 SYSCTL_UINT(_net_inet_tcp, OID_AUTO, usrlog_stale, CTLFLAG_RW,
4377 &tcp_stale_entry_time, 250000, "Time that a tcpreq entry without a sendfile ages out");
4378
4379 void
tcp_req_log_req_info(struct tcpcb * tp,struct tcp_sendfile_track * req,uint16_t slot,uint8_t val,uint64_t offset,uint64_t nbytes)4380 tcp_req_log_req_info(struct tcpcb *tp, struct tcp_sendfile_track *req,
4381 uint16_t slot, uint8_t val, uint64_t offset, uint64_t nbytes)
4382 {
4383 if (tcp_bblogging_on(tp)) {
4384 union tcp_log_stackspecific log;
4385 struct timeval tv;
4386
4387 memset(&log.u_bbr, 0, sizeof(log.u_bbr));
4388 log.u_bbr.inhpts = tcp_in_hpts(tp);
4389 log.u_bbr.flex8 = val;
4390 log.u_bbr.rttProp = req->timestamp;
4391 log.u_bbr.delRate = req->start;
4392 log.u_bbr.cur_del_rate = req->end;
4393 log.u_bbr.flex1 = req->start_seq;
4394 log.u_bbr.flex2 = req->end_seq;
4395 log.u_bbr.flex3 = req->flags;
4396 log.u_bbr.flex4 = ((req->localtime >> 32) & 0x00000000ffffffff);
4397 log.u_bbr.flex5 = (req->localtime & 0x00000000ffffffff);
4398 log.u_bbr.flex7 = slot;
4399 log.u_bbr.bw_inuse = offset;
4400 /* nbytes = flex6 | epoch */
4401 log.u_bbr.flex6 = ((nbytes >> 32) & 0x00000000ffffffff);
4402 log.u_bbr.epoch = (nbytes & 0x00000000ffffffff);
4403 /* cspr = lt_epoch | pkts_out */
4404 log.u_bbr.lt_epoch = ((req->cspr >> 32) & 0x00000000ffffffff);
4405 log.u_bbr.pkts_out |= (req->cspr & 0x00000000ffffffff);
4406 log.u_bbr.applimited = tp->t_tcpreq_closed;
4407 log.u_bbr.applimited <<= 8;
4408 log.u_bbr.applimited |= tp->t_tcpreq_open;
4409 log.u_bbr.applimited <<= 8;
4410 log.u_bbr.applimited |= tp->t_tcpreq_req;
4411 log.u_bbr.timeStamp = tcp_get_usecs(&tv);
4412 TCP_LOG_EVENTP(tp, NULL,
4413 &tptosocket(tp)->so_rcv,
4414 &tptosocket(tp)->so_snd,
4415 TCP_LOG_REQ_T, 0,
4416 0, &log, false, &tv);
4417 }
4418 }
4419
4420 void
tcp_req_free_a_slot(struct tcpcb * tp,struct tcp_sendfile_track * ent)4421 tcp_req_free_a_slot(struct tcpcb *tp, struct tcp_sendfile_track *ent)
4422 {
4423 if (tp->t_tcpreq_req > 0)
4424 tp->t_tcpreq_req--;
4425 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) {
4426 if (tp->t_tcpreq_open > 0)
4427 tp->t_tcpreq_open--;
4428 } else {
4429 if (tp->t_tcpreq_closed > 0)
4430 tp->t_tcpreq_closed--;
4431 }
4432 ent->flags = TCP_TRK_TRACK_FLG_EMPTY;
4433 }
4434
4435 static void
tcp_req_check_for_stale_entries(struct tcpcb * tp,uint64_t ts,int rm_oldest)4436 tcp_req_check_for_stale_entries(struct tcpcb *tp, uint64_t ts, int rm_oldest)
4437 {
4438 struct tcp_sendfile_track *ent;
4439 uint64_t time_delta, oldest_delta;
4440 int i, oldest, oldest_set = 0, cnt_rm = 0;
4441
4442 for (i = 0; i < MAX_TCP_TRK_REQ; i++) {
4443 ent = &tp->t_tcpreq_info[i];
4444 if (ent->flags != TCP_TRK_TRACK_FLG_USED) {
4445 /*
4446 * We only care about closed end ranges
4447 * that are allocated and have no sendfile
4448 * ever touching them. They would be in
4449 * state USED.
4450 */
4451 continue;
4452 }
4453 if (ts >= ent->localtime)
4454 time_delta = ts - ent->localtime;
4455 else
4456 time_delta = 0;
4457 if (time_delta &&
4458 ((oldest_delta < time_delta) || (oldest_set == 0))) {
4459 oldest_set = 1;
4460 oldest = i;
4461 oldest_delta = time_delta;
4462 }
4463 if (tcp_stale_entry_time && (time_delta >= tcp_stale_entry_time)) {
4464 /*
4465 * No sendfile in a our time-limit
4466 * time to purge it.
4467 */
4468 cnt_rm++;
4469 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE,
4470 time_delta, 0);
4471 tcp_req_free_a_slot(tp, ent);
4472 }
4473 }
4474 if ((cnt_rm == 0) && rm_oldest && oldest_set) {
4475 ent = &tp->t_tcpreq_info[oldest];
4476 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i], i, TCP_TRK_REQ_LOG_STALE,
4477 oldest_delta, 1);
4478 tcp_req_free_a_slot(tp, ent);
4479 }
4480 }
4481
4482 int
tcp_req_check_for_comp(struct tcpcb * tp,tcp_seq ack_point)4483 tcp_req_check_for_comp(struct tcpcb *tp, tcp_seq ack_point)
4484 {
4485 int i, ret = 0;
4486 struct tcp_sendfile_track *ent;
4487
4488 /* Clean up any old closed end requests that are now completed */
4489 if (tp->t_tcpreq_req == 0)
4490 return (0);
4491 if (tp->t_tcpreq_closed == 0)
4492 return (0);
4493 for (i = 0; i < MAX_TCP_TRK_REQ; i++) {
4494 ent = &tp->t_tcpreq_info[i];
4495 /* Skip empty ones */
4496 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY)
4497 continue;
4498 /* Skip open ones */
4499 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN)
4500 continue;
4501 if (SEQ_GEQ(ack_point, ent->end_seq)) {
4502 /* We are past it -- free it */
4503 tcp_req_log_req_info(tp, ent,
4504 i, TCP_TRK_REQ_LOG_FREED, 0, 0);
4505 tcp_req_free_a_slot(tp, ent);
4506 ret++;
4507 }
4508 }
4509 return (ret);
4510 }
4511
4512 int
tcp_req_is_entry_comp(struct tcpcb * tp,struct tcp_sendfile_track * ent,tcp_seq ack_point)4513 tcp_req_is_entry_comp(struct tcpcb *tp, struct tcp_sendfile_track *ent, tcp_seq ack_point)
4514 {
4515 if (tp->t_tcpreq_req == 0)
4516 return (-1);
4517 if (tp->t_tcpreq_closed == 0)
4518 return (-1);
4519 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY)
4520 return (-1);
4521 if (SEQ_GEQ(ack_point, ent->end_seq)) {
4522 return (1);
4523 }
4524 return (0);
4525 }
4526
4527 struct tcp_sendfile_track *
tcp_req_find_a_req_that_is_completed_by(struct tcpcb * tp,tcp_seq th_ack,int * ip)4528 tcp_req_find_a_req_that_is_completed_by(struct tcpcb *tp, tcp_seq th_ack, int *ip)
4529 {
4530 /*
4531 * Given an ack point (th_ack) walk through our entries and
4532 * return the first one found that th_ack goes past the
4533 * end_seq.
4534 */
4535 struct tcp_sendfile_track *ent;
4536 int i;
4537
4538 if (tp->t_tcpreq_req == 0) {
4539 /* none open */
4540 return (NULL);
4541 }
4542 for (i = 0; i < MAX_TCP_TRK_REQ; i++) {
4543 ent = &tp->t_tcpreq_info[i];
4544 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY)
4545 continue;
4546 if ((ent->flags & TCP_TRK_TRACK_FLG_OPEN) == 0) {
4547 if (SEQ_GEQ(th_ack, ent->end_seq)) {
4548 *ip = i;
4549 return (ent);
4550 }
4551 }
4552 }
4553 return (NULL);
4554 }
4555
4556 struct tcp_sendfile_track *
tcp_req_find_req_for_seq(struct tcpcb * tp,tcp_seq seq)4557 tcp_req_find_req_for_seq(struct tcpcb *tp, tcp_seq seq)
4558 {
4559 struct tcp_sendfile_track *ent;
4560 int i;
4561
4562 if (tp->t_tcpreq_req == 0) {
4563 /* none open */
4564 return (NULL);
4565 }
4566 for (i = 0; i < MAX_TCP_TRK_REQ; i++) {
4567 ent = &tp->t_tcpreq_info[i];
4568 tcp_req_log_req_info(tp, ent, i, TCP_TRK_REQ_LOG_SEARCH,
4569 (uint64_t)seq, 0);
4570 if (ent->flags == TCP_TRK_TRACK_FLG_EMPTY) {
4571 continue;
4572 }
4573 if (ent->flags & TCP_TRK_TRACK_FLG_OPEN) {
4574 /*
4575 * An open end request only needs to
4576 * match the beginning seq or be
4577 * all we have (once we keep going on
4578 * a open end request we may have a seq
4579 * wrap).
4580 */
4581 if ((SEQ_GEQ(seq, ent->start_seq)) ||
4582 (tp->t_tcpreq_closed == 0))
4583 return (ent);
4584 } else {
4585 /*
4586 * For this one we need to
4587 * be a bit more careful if its
4588 * completed at least.
4589 */
4590 if ((SEQ_GEQ(seq, ent->start_seq)) &&
4591 (SEQ_LT(seq, ent->end_seq))) {
4592 return (ent);
4593 }
4594 }
4595 }
4596 return (NULL);
4597 }
4598
4599 /* Should this be in its own file tcp_req.c ? */
4600 struct tcp_sendfile_track *
tcp_req_alloc_req_full(struct tcpcb * tp,struct tcp_snd_req * req,uint64_t ts,int rec_dups)4601 tcp_req_alloc_req_full(struct tcpcb *tp, struct tcp_snd_req *req, uint64_t ts, int rec_dups)
4602 {
4603 struct tcp_sendfile_track *fil;
4604 int i, allocated;
4605
4606 /* In case the stack does not check for completions do so now */
4607 tcp_req_check_for_comp(tp, tp->snd_una);
4608 /* Check for stale entries */
4609 if (tp->t_tcpreq_req)
4610 tcp_req_check_for_stale_entries(tp, ts,
4611 (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ));
4612 /* Check to see if this is a duplicate of one not started */
4613 if (tp->t_tcpreq_req) {
4614 for (i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) {
4615 fil = &tp->t_tcpreq_info[i];
4616 if ((fil->flags & TCP_TRK_TRACK_FLG_USED) == 0)
4617 continue;
4618 if ((fil->timestamp == req->timestamp) &&
4619 (fil->start == req->start) &&
4620 ((fil->flags & TCP_TRK_TRACK_FLG_OPEN) ||
4621 (fil->end == req->end))) {
4622 /*
4623 * We already have this request
4624 * and it has not been started with sendfile.
4625 * This probably means the user was returned
4626 * a 4xx of some sort and its going to age
4627 * out, lets not duplicate it.
4628 */
4629 return (fil);
4630 }
4631 }
4632 }
4633 /* Ok if there is no room at the inn we are in trouble */
4634 if (tp->t_tcpreq_req >= MAX_TCP_TRK_REQ) {
4635 tcp_trace_point(tp, TCP_TP_REQ_LOG_FAIL);
4636 for (i = 0; i < MAX_TCP_TRK_REQ; i++) {
4637 tcp_req_log_req_info(tp, &tp->t_tcpreq_info[i],
4638 i, TCP_TRK_REQ_LOG_ALLOCFAIL, 0, 0);
4639 }
4640 return (NULL);
4641 }
4642 for (i = 0, allocated = 0; i < MAX_TCP_TRK_REQ; i++) {
4643 fil = &tp->t_tcpreq_info[i];
4644 if (fil->flags == TCP_TRK_TRACK_FLG_EMPTY) {
4645 allocated = 1;
4646 fil->flags = TCP_TRK_TRACK_FLG_USED;
4647 fil->timestamp = req->timestamp;
4648 fil->playout_ms = req->playout_ms;
4649 fil->localtime = ts;
4650 fil->start = req->start;
4651 if (req->flags & TCP_LOG_HTTPD_RANGE_END) {
4652 fil->end = req->end;
4653 } else {
4654 fil->end = 0;
4655 fil->flags |= TCP_TRK_TRACK_FLG_OPEN;
4656 }
4657 /*
4658 * We can set the min boundaries to the TCP Sequence space,
4659 * but it might be found to be further up when sendfile
4660 * actually runs on this range (if it ever does).
4661 */
4662 fil->sbcc_at_s = tptosocket(tp)->so_snd.sb_ccc;
4663 fil->start_seq = tp->snd_una +
4664 tptosocket(tp)->so_snd.sb_ccc;
4665 if (req->flags & TCP_LOG_HTTPD_RANGE_END)
4666 fil->end_seq = (fil->start_seq + ((uint32_t)(fil->end - fil->start)));
4667 else
4668 fil->end_seq = 0;
4669 if (tptosocket(tp)->so_snd.sb_tls_info) {
4670 /*
4671 * This session is doing TLS. Take a swag guess
4672 * at the overhead.
4673 */
4674 fil->end_seq += tcp_estimate_tls_overhead(
4675 tptosocket(tp), (fil->end - fil->start));
4676 }
4677 tp->t_tcpreq_req++;
4678 if (fil->flags & TCP_TRK_TRACK_FLG_OPEN)
4679 tp->t_tcpreq_open++;
4680 else
4681 tp->t_tcpreq_closed++;
4682 tcp_req_log_req_info(tp, fil, i,
4683 TCP_TRK_REQ_LOG_NEW, 0, 0);
4684 break;
4685 } else
4686 fil = NULL;
4687 }
4688 return (fil);
4689 }
4690
4691 void
tcp_req_alloc_req(struct tcpcb * tp,union tcp_log_userdata * user,uint64_t ts)4692 tcp_req_alloc_req(struct tcpcb *tp, union tcp_log_userdata *user, uint64_t ts)
4693 {
4694 (void)tcp_req_alloc_req_full(tp, &user->tcp_req, ts, 1);
4695 }
4696 #endif
4697
4698 void
tcp_log_socket_option(struct tcpcb * tp,uint32_t option_num,uint32_t option_val,int err)4699 tcp_log_socket_option(struct tcpcb *tp, uint32_t option_num, uint32_t option_val, int err)
4700 {
4701 if (tcp_bblogging_on(tp)) {
4702 struct tcp_log_buffer *l;
4703
4704 l = tcp_log_event(tp, NULL,
4705 &tptosocket(tp)->so_rcv,
4706 &tptosocket(tp)->so_snd,
4707 TCP_LOG_SOCKET_OPT,
4708 err, 0, NULL, 1,
4709 NULL, NULL, 0, NULL);
4710 if (l) {
4711 l->tlb_flex1 = option_num;
4712 l->tlb_flex2 = option_val;
4713 }
4714 }
4715 }
4716
4717 uint32_t
tcp_get_srtt(struct tcpcb * tp,int granularity)4718 tcp_get_srtt(struct tcpcb *tp, int granularity)
4719 {
4720 uint32_t srtt;
4721
4722 KASSERT(granularity == TCP_TMR_GRANULARITY_USEC ||
4723 granularity == TCP_TMR_GRANULARITY_TICKS,
4724 ("%s: called with unexpected granularity %d", __func__,
4725 granularity));
4726
4727 srtt = tp->t_srtt;
4728
4729 /*
4730 * We only support two granularities. If the stored granularity
4731 * does not match the granularity requested by the caller,
4732 * convert the stored value to the requested unit of granularity.
4733 */
4734 if (tp->t_tmr_granularity != granularity) {
4735 if (granularity == TCP_TMR_GRANULARITY_USEC)
4736 srtt = TICKS_2_USEC(srtt);
4737 else
4738 srtt = USEC_2_TICKS(srtt);
4739 }
4740
4741 /*
4742 * If the srtt is stored with ticks granularity, we need to
4743 * unshift to get the actual value. We do this after the
4744 * conversion above (if one was necessary) in order to maximize
4745 * precision.
4746 */
4747 if (tp->t_tmr_granularity == TCP_TMR_GRANULARITY_TICKS)
4748 srtt = srtt >> TCP_RTT_SHIFT;
4749
4750 return (srtt);
4751 }
4752
4753 void
tcp_account_for_send(struct tcpcb * tp,uint32_t len,uint8_t is_rxt,uint8_t is_tlp,bool hw_tls)4754 tcp_account_for_send(struct tcpcb *tp, uint32_t len, uint8_t is_rxt,
4755 uint8_t is_tlp, bool hw_tls)
4756 {
4757
4758 if (is_tlp) {
4759 tp->t_sndtlppack++;
4760 tp->t_sndtlpbyte += len;
4761 }
4762 /* To get total bytes sent you must add t_snd_rxt_bytes to t_sndbytes */
4763 if (is_rxt)
4764 tp->t_snd_rxt_bytes += len;
4765 else
4766 tp->t_sndbytes += len;
4767
4768 #ifdef KERN_TLS
4769 if (hw_tls && is_rxt && len != 0) {
4770 uint64_t rexmit_percent;
4771
4772 rexmit_percent = (1000ULL * tp->t_snd_rxt_bytes) /
4773 (10ULL * (tp->t_snd_rxt_bytes + tp->t_sndbytes));
4774 if (rexmit_percent > ktls_ifnet_max_rexmit_pct)
4775 ktls_disable_ifnet(tp);
4776 }
4777 #endif
4778 }
4779