1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2007, Myricom Inc.
5 * Copyright (c) 2008, Intel Corporation.
6 * Copyright (c) 2012 The FreeBSD Foundation
7 * Copyright (c) 2016-2021 Mellanox Technologies.
8 * All rights reserved.
9 *
10 * Portions of this software were developed by Bjoern Zeeb
11 * under sponsorship from the FreeBSD Foundation.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #include <sys/cdefs.h>
36 #include "opt_inet.h"
37 #include "opt_inet6.h"
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/mbuf.h>
44 #include <sys/socket.h>
45 #include <sys/socketvar.h>
46 #include <sys/sockbuf.h>
47 #include <sys/sysctl.h>
48
49 #include <net/if.h>
50 #include <net/if_var.h>
51 #include <net/ethernet.h>
52 #include <net/bpf.h>
53 #include <net/vnet.h>
54 #include <net/if_dl.h>
55 #include <net/if_media.h>
56 #include <net/if_private.h>
57 #include <net/if_types.h>
58 #include <net/infiniband.h>
59 #include <net/if_lagg.h>
60
61 #include <netinet/in_systm.h>
62 #include <netinet/in.h>
63 #include <netinet/ip6.h>
64 #include <netinet/ip.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/in_pcb.h>
67 #include <netinet6/in6_pcb.h>
68 #include <netinet/tcp.h>
69 #include <netinet/tcp_seq.h>
70 #include <netinet/tcp_lro.h>
71 #include <netinet/tcp_var.h>
72 #include <netinet/tcpip.h>
73 #include <netinet/tcp_hpts.h>
74 #include <netinet/tcp_log_buf.h>
75 #include <netinet/tcp_fsm.h>
76 #include <netinet/udp.h>
77 #include <netinet6/ip6_var.h>
78
79 #include <machine/in_cksum.h>
80
81 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
82
83 static void tcp_lro_rx_done(struct lro_ctrl *lc);
84 static int tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m,
85 uint32_t csum, bool use_hash);
86 static void tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le);
87
88 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
89 "TCP LRO");
90
91 long tcplro_stacks_wanting_mbufq;
92 int (*tcp_lro_flush_tcphpts)(struct lro_ctrl *lc, struct lro_entry *le);
93
94 counter_u64_t tcp_inp_lro_direct_queue;
95 counter_u64_t tcp_inp_lro_wokeup_queue;
96 counter_u64_t tcp_inp_lro_compressed;
97 counter_u64_t tcp_inp_lro_locks_taken;
98 counter_u64_t tcp_extra_mbuf;
99 counter_u64_t tcp_would_have_but;
100 counter_u64_t tcp_comp_total;
101 counter_u64_t tcp_uncomp_total;
102 counter_u64_t tcp_bad_csums;
103
104 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
105 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
106 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
107 "default number of LRO entries");
108
109 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
110 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
111 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
112 "Number of interrupts in a row on the same CPU that will make us declare an 'affinity' cpu?");
113
114 static uint32_t tcp_less_accurate_lro_ts = 0;
115 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_less_accurate,
116 CTLFLAG_MPSAFE, &tcp_less_accurate_lro_ts, 0,
117 "Do we trade off efficency by doing less timestamp operations for time accuracy?");
118
119 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
120 &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
121 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
122 &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
123 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
124 &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
125 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
126 &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
127 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
128 &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
129 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
130 &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
131 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
132 &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
133 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
134 &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
135 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lro_badcsum, CTLFLAG_RD,
136 &tcp_bad_csums, "Number of packets that the common code saw with bad csums");
137
138 void
tcp_lro_reg_mbufq(void)139 tcp_lro_reg_mbufq(void)
140 {
141 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
142 }
143
144 void
tcp_lro_dereg_mbufq(void)145 tcp_lro_dereg_mbufq(void)
146 {
147 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
148 }
149
150 static __inline void
tcp_lro_active_insert(struct lro_ctrl * lc,struct lro_head * bucket,struct lro_entry * le)151 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
152 struct lro_entry *le)
153 {
154
155 LIST_INSERT_HEAD(&lc->lro_active, le, next);
156 LIST_INSERT_HEAD(bucket, le, hash_next);
157 }
158
159 static __inline void
tcp_lro_active_remove(struct lro_entry * le)160 tcp_lro_active_remove(struct lro_entry *le)
161 {
162
163 LIST_REMOVE(le, next); /* active list */
164 LIST_REMOVE(le, hash_next); /* hash bucket */
165 }
166
167 int
tcp_lro_init(struct lro_ctrl * lc)168 tcp_lro_init(struct lro_ctrl *lc)
169 {
170 return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
171 }
172
173 int
tcp_lro_init_args(struct lro_ctrl * lc,struct ifnet * ifp,unsigned lro_entries,unsigned lro_mbufs)174 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
175 unsigned lro_entries, unsigned lro_mbufs)
176 {
177 struct lro_entry *le;
178 size_t size;
179 unsigned i;
180
181 lc->lro_bad_csum = 0;
182 lc->lro_queued = 0;
183 lc->lro_flushed = 0;
184 lc->lro_mbuf_count = 0;
185 lc->lro_mbuf_max = lro_mbufs;
186 lc->lro_cnt = lro_entries;
187 lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
188 lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
189 lc->ifp = ifp;
190 LIST_INIT(&lc->lro_free);
191 LIST_INIT(&lc->lro_active);
192
193 /* create hash table to accelerate entry lookup */
194 lc->lro_hash = phashinit_flags(lro_entries, M_LRO, &lc->lro_hashsz,
195 HASH_NOWAIT);
196 if (lc->lro_hash == NULL) {
197 memset(lc, 0, sizeof(*lc));
198 return (ENOMEM);
199 }
200
201 /* compute size to allocate */
202 size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
203 (lro_entries * sizeof(*le));
204 lc->lro_mbuf_data = (struct lro_mbuf_sort *)
205 malloc(size, M_LRO, M_NOWAIT | M_ZERO);
206
207 /* check for out of memory */
208 if (lc->lro_mbuf_data == NULL) {
209 free(lc->lro_hash, M_LRO);
210 memset(lc, 0, sizeof(*lc));
211 return (ENOMEM);
212 }
213 /* compute offset for LRO entries */
214 le = (struct lro_entry *)
215 (lc->lro_mbuf_data + lro_mbufs);
216
217 /* setup linked list */
218 for (i = 0; i != lro_entries; i++)
219 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
220
221 return (0);
222 }
223
224 struct vxlan_header {
225 uint32_t vxlh_flags;
226 uint32_t vxlh_vni;
227 };
228
229 static inline void *
tcp_lro_low_level_parser(void * ptr,struct lro_parser * parser,bool update_data,bool is_vxlan,int mlen)230 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan, int mlen)
231 {
232 const struct ether_vlan_header *eh;
233 void *old;
234 uint16_t eth_type;
235
236 if (update_data)
237 memset(parser, 0, sizeof(*parser));
238
239 old = ptr;
240
241 if (is_vxlan) {
242 const struct vxlan_header *vxh;
243 vxh = ptr;
244 ptr = (uint8_t *)ptr + sizeof(*vxh);
245 if (update_data) {
246 parser->data.vxlan_vni =
247 vxh->vxlh_vni & htonl(0xffffff00);
248 }
249 }
250
251 eh = ptr;
252 if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
253 eth_type = eh->evl_proto;
254 if (update_data) {
255 /* strip priority and keep VLAN ID only */
256 parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
257 }
258 /* advance to next header */
259 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
260 mlen -= (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
261 } else {
262 eth_type = eh->evl_encap_proto;
263 /* advance to next header */
264 mlen -= ETHER_HDR_LEN;
265 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
266 }
267 if (__predict_false(mlen <= 0))
268 return (NULL);
269 switch (eth_type) {
270 #ifdef INET
271 case htons(ETHERTYPE_IP):
272 parser->ip4 = ptr;
273 if (__predict_false(mlen < sizeof(struct ip)))
274 return (NULL);
275 /* Ensure there are no IPv4 options. */
276 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
277 break;
278 /* .. and the packet is not fragmented. */
279 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
280 break;
281 /* .. and the packet has valid src/dst addrs */
282 if (__predict_false(parser->ip4->ip_src.s_addr == INADDR_ANY ||
283 parser->ip4->ip_dst.s_addr == INADDR_ANY))
284 break;
285 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
286 mlen -= sizeof(struct ip);
287 if (update_data) {
288 parser->data.s_addr.v4 = parser->ip4->ip_src;
289 parser->data.d_addr.v4 = parser->ip4->ip_dst;
290 }
291 switch (parser->ip4->ip_p) {
292 case IPPROTO_UDP:
293 if (__predict_false(mlen < sizeof(struct udphdr)))
294 return (NULL);
295 parser->udp = ptr;
296 if (update_data) {
297 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
298 parser->data.s_port = parser->udp->uh_sport;
299 parser->data.d_port = parser->udp->uh_dport;
300 } else {
301 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
302 }
303 ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
304 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
305 return (ptr);
306 case IPPROTO_TCP:
307 parser->tcp = ptr;
308 if (__predict_false(mlen < sizeof(struct tcphdr)))
309 return (NULL);
310 if (update_data) {
311 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
312 parser->data.s_port = parser->tcp->th_sport;
313 parser->data.d_port = parser->tcp->th_dport;
314 } else {
315 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
316 }
317 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
318 return (NULL);
319 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
320 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
321 return (ptr);
322 default:
323 break;
324 }
325 break;
326 #endif
327 #ifdef INET6
328 case htons(ETHERTYPE_IPV6):
329 parser->ip6 = ptr;
330 if (__predict_false(mlen < sizeof(struct ip6_hdr)))
331 return (NULL);
332 /* Ensure the packet has valid src/dst addrs */
333 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_src) ||
334 IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_dst)))
335 return (NULL);
336 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
337 if (update_data) {
338 parser->data.s_addr.v6 = parser->ip6->ip6_src;
339 parser->data.d_addr.v6 = parser->ip6->ip6_dst;
340 }
341 mlen -= sizeof(struct ip6_hdr);
342 switch (parser->ip6->ip6_nxt) {
343 case IPPROTO_UDP:
344 if (__predict_false(mlen < sizeof(struct udphdr)))
345 return (NULL);
346 parser->udp = ptr;
347 if (update_data) {
348 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
349 parser->data.s_port = parser->udp->uh_sport;
350 parser->data.d_port = parser->udp->uh_dport;
351 } else {
352 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
353 }
354 ptr = (uint8_t *)ptr + sizeof(*parser->udp);
355 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
356 return (ptr);
357 case IPPROTO_TCP:
358 if (__predict_false(mlen < sizeof(struct tcphdr)))
359 return (NULL);
360 parser->tcp = ptr;
361 if (update_data) {
362 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
363 parser->data.s_port = parser->tcp->th_sport;
364 parser->data.d_port = parser->tcp->th_dport;
365 } else {
366 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
367 }
368 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
369 return (NULL);
370 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
371 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
372 return (ptr);
373 default:
374 break;
375 }
376 break;
377 #endif
378 default:
379 break;
380 }
381 /* Invalid packet - cannot parse */
382 return (NULL);
383 }
384
385 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
386 CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
387
388 static inline struct lro_parser *
tcp_lro_parser(struct mbuf * m,struct lro_parser * po,struct lro_parser * pi,bool update_data)389 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
390 {
391 void *data_ptr;
392
393 /* Try to parse outer headers first. */
394 data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false, m->m_len);
395 if (data_ptr == NULL || po->total_hdr_len > m->m_len)
396 return (NULL);
397
398 if (update_data) {
399 /* Store VLAN ID, if any. */
400 if (__predict_false(m->m_flags & M_VLANTAG)) {
401 po->data.vlan_id =
402 htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
403 }
404 /* Store decrypted flag, if any. */
405 if (__predict_false((m->m_pkthdr.csum_flags &
406 CSUM_TLS_MASK) == CSUM_TLS_DECRYPTED))
407 po->data.lro_flags |= LRO_FLAG_DECRYPTED;
408 }
409
410 switch (po->data.lro_type) {
411 case LRO_TYPE_IPV4_UDP:
412 case LRO_TYPE_IPV6_UDP:
413 /* Check for VXLAN headers. */
414 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
415 break;
416
417 /* Try to parse inner headers. */
418 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true,
419 (m->m_len - ((caddr_t)data_ptr - m->m_data)));
420 if (data_ptr == NULL || (pi->total_hdr_len + po->total_hdr_len) > m->m_len)
421 break;
422
423 /* Verify supported header types. */
424 switch (pi->data.lro_type) {
425 case LRO_TYPE_IPV4_TCP:
426 case LRO_TYPE_IPV6_TCP:
427 return (pi);
428 default:
429 break;
430 }
431 break;
432 case LRO_TYPE_IPV4_TCP:
433 case LRO_TYPE_IPV6_TCP:
434 if (update_data)
435 memset(pi, 0, sizeof(*pi));
436 return (po);
437 default:
438 break;
439 }
440 return (NULL);
441 }
442
443 static inline int
tcp_lro_trim_mbuf_chain(struct mbuf * m,const struct lro_parser * po)444 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
445 {
446 int len;
447
448 switch (po->data.lro_type) {
449 #ifdef INET
450 case LRO_TYPE_IPV4_TCP:
451 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
452 ntohs(po->ip4->ip_len);
453 break;
454 #endif
455 #ifdef INET6
456 case LRO_TYPE_IPV6_TCP:
457 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
458 ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
459 break;
460 #endif
461 default:
462 return (TCP_LRO_CANNOT);
463 }
464
465 /*
466 * If the frame is padded beyond the end of the IP packet,
467 * then trim the extra bytes off:
468 */
469 if (__predict_true(m->m_pkthdr.len == len)) {
470 return (0);
471 } else if (m->m_pkthdr.len > len) {
472 m_adj(m, len - m->m_pkthdr.len);
473 return (0);
474 }
475 return (TCP_LRO_CANNOT);
476 }
477
478 static void
lro_free_mbuf_chain(struct mbuf * m)479 lro_free_mbuf_chain(struct mbuf *m)
480 {
481 struct mbuf *save;
482
483 while (m) {
484 save = m->m_nextpkt;
485 m->m_nextpkt = NULL;
486 m_freem(m);
487 m = save;
488 }
489 }
490
491 void
tcp_lro_free(struct lro_ctrl * lc)492 tcp_lro_free(struct lro_ctrl *lc)
493 {
494 struct lro_entry *le;
495 unsigned x;
496
497 /* reset LRO free list */
498 LIST_INIT(&lc->lro_free);
499
500 /* free active mbufs, if any */
501 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
502 tcp_lro_active_remove(le);
503 lro_free_mbuf_chain(le->m_head);
504 }
505
506 /* free hash table */
507 free(lc->lro_hash, M_LRO);
508 lc->lro_hash = NULL;
509 lc->lro_hashsz = 0;
510
511 /* free mbuf array, if any */
512 for (x = 0; x != lc->lro_mbuf_count; x++)
513 m_freem(lc->lro_mbuf_data[x].mb);
514 lc->lro_mbuf_count = 0;
515
516 /* free allocated memory, if any */
517 free(lc->lro_mbuf_data, M_LRO);
518 lc->lro_mbuf_data = NULL;
519 }
520
521 static uint16_t
tcp_lro_rx_csum_tcphdr(const struct tcphdr * th)522 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
523 {
524 const uint16_t *ptr;
525 uint32_t csum;
526 uint16_t len;
527
528 csum = -th->th_sum; /* exclude checksum field */
529 len = th->th_off;
530 ptr = (const uint16_t *)th;
531 while (len--) {
532 csum += *ptr;
533 ptr++;
534 csum += *ptr;
535 ptr++;
536 }
537 while (csum > 0xffff)
538 csum = (csum >> 16) + (csum & 0xffff);
539
540 return (csum);
541 }
542
543 static uint16_t
tcp_lro_rx_csum_data(const struct lro_parser * pa,uint16_t tcp_csum)544 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
545 {
546 uint32_t c;
547 uint16_t cs;
548
549 c = tcp_csum;
550
551 switch (pa->data.lro_type) {
552 #ifdef INET6
553 case LRO_TYPE_IPV6_TCP:
554 /* Compute full pseudo IPv6 header checksum. */
555 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
556 break;
557 #endif
558 #ifdef INET
559 case LRO_TYPE_IPV4_TCP:
560 /* Compute full pseudo IPv4 header checsum. */
561 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
562 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
563 break;
564 #endif
565 default:
566 cs = 0; /* Keep compiler happy. */
567 break;
568 }
569
570 /* Complement checksum. */
571 cs = ~cs;
572 c += cs;
573
574 /* Remove TCP header checksum. */
575 cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
576 c += cs;
577
578 /* Compute checksum remainder. */
579 while (c > 0xffff)
580 c = (c >> 16) + (c & 0xffff);
581
582 return (c);
583 }
584
585 static void
tcp_lro_rx_done(struct lro_ctrl * lc)586 tcp_lro_rx_done(struct lro_ctrl *lc)
587 {
588 struct lro_entry *le;
589
590 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
591 tcp_lro_active_remove(le);
592 tcp_lro_flush(lc, le);
593 }
594 }
595
596 static void
tcp_lro_flush_active(struct lro_ctrl * lc)597 tcp_lro_flush_active(struct lro_ctrl *lc)
598 {
599 struct lro_entry *le, *le_tmp;
600
601 /*
602 * Walk through the list of le entries, and
603 * any one that does have packets flush. This
604 * is called because we have an inbound packet
605 * (e.g. SYN) that has to have all others flushed
606 * in front of it. Note we have to do the remove
607 * because tcp_lro_flush() assumes that the entry
608 * is being freed. This is ok it will just get
609 * reallocated again like it was new.
610 */
611 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
612 if (le->m_head != NULL) {
613 tcp_lro_active_remove(le);
614 tcp_lro_flush(lc, le);
615 }
616 }
617 }
618
619 void
tcp_lro_flush_inactive(struct lro_ctrl * lc,const struct timeval * timeout)620 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
621 {
622 struct lro_entry *le, *le_tmp;
623 uint64_t now, tov;
624 struct bintime bt;
625
626 NET_EPOCH_ASSERT();
627 if (LIST_EMPTY(&lc->lro_active))
628 return;
629
630 /* get timeout time and current time in ns */
631 binuptime(&bt);
632 now = bintime2ns(&bt);
633 tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
634 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
635 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
636 tcp_lro_active_remove(le);
637 tcp_lro_flush(lc, le);
638 }
639 }
640 }
641
642 #ifdef INET
643 static int
tcp_lro_rx_ipv4(struct lro_ctrl * lc,struct mbuf * m,struct ip * ip4)644 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
645 {
646 uint16_t csum;
647
648 /* Legacy IP has a header checksum that needs to be correct. */
649 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
650 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
651 lc->lro_bad_csum++;
652 return (TCP_LRO_CANNOT);
653 }
654 } else {
655 csum = in_cksum_hdr(ip4);
656 if (__predict_false(csum != 0)) {
657 lc->lro_bad_csum++;
658 return (TCP_LRO_CANNOT);
659 }
660 }
661 return (0);
662 }
663 #endif
664
665 static inline void
tcp_lro_assign_and_checksum_16(uint16_t * ptr,uint16_t value,uint16_t * psum)666 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
667 {
668 uint32_t csum;
669
670 csum = 0xffff - *ptr + value;
671 while (csum > 0xffff)
672 csum = (csum >> 16) + (csum & 0xffff);
673 *ptr = value;
674 *psum = csum;
675 }
676
677 static uint16_t
tcp_lro_update_checksum(const struct lro_parser * pa,const struct lro_entry * le,uint16_t payload_len,uint16_t delta_sum)678 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
679 uint16_t payload_len, uint16_t delta_sum)
680 {
681 uint32_t csum;
682 uint16_t tlen;
683 uint16_t temp[5] = {};
684
685 switch (pa->data.lro_type) {
686 case LRO_TYPE_IPV4_TCP:
687 /* Compute new IPv4 length. */
688 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
689 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
690
691 /* Subtract delta from current IPv4 checksum. */
692 csum = pa->ip4->ip_sum + 0xffff - temp[0];
693 while (csum > 0xffff)
694 csum = (csum >> 16) + (csum & 0xffff);
695 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
696 goto update_tcp_header;
697
698 case LRO_TYPE_IPV6_TCP:
699 /* Compute new IPv6 length. */
700 tlen = (pa->tcp->th_off << 2) + payload_len;
701 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
702 goto update_tcp_header;
703
704 case LRO_TYPE_IPV4_UDP:
705 /* Compute new IPv4 length. */
706 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
707 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
708
709 /* Subtract delta from current IPv4 checksum. */
710 csum = pa->ip4->ip_sum + 0xffff - temp[0];
711 while (csum > 0xffff)
712 csum = (csum >> 16) + (csum & 0xffff);
713 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
714 goto update_udp_header;
715
716 case LRO_TYPE_IPV6_UDP:
717 /* Compute new IPv6 length. */
718 tlen = sizeof(*pa->udp) + payload_len;
719 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
720 goto update_udp_header;
721
722 default:
723 return (0);
724 }
725
726 update_tcp_header:
727 /* Compute current TCP header checksum. */
728 temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
729
730 /* Incorporate the latest ACK into the TCP header. */
731 pa->tcp->th_ack = le->ack_seq;
732 pa->tcp->th_win = le->window;
733
734 /* Incorporate latest timestamp into the TCP header. */
735 if (le->timestamp != 0) {
736 uint32_t *ts_ptr;
737
738 ts_ptr = (uint32_t *)(pa->tcp + 1);
739 ts_ptr[1] = htonl(le->tsval);
740 ts_ptr[2] = le->tsecr;
741 }
742
743 /* Compute new TCP header checksum. */
744 temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
745
746 /* Compute new TCP checksum. */
747 csum = pa->tcp->th_sum + 0xffff - delta_sum +
748 0xffff - temp[0] + 0xffff - temp[3] + temp[2];
749 while (csum > 0xffff)
750 csum = (csum >> 16) + (csum & 0xffff);
751
752 /* Assign new TCP checksum. */
753 tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
754
755 /* Compute all modififications affecting next checksum. */
756 csum = temp[0] + temp[1] + 0xffff - temp[2] +
757 temp[3] + temp[4] + delta_sum;
758 while (csum > 0xffff)
759 csum = (csum >> 16) + (csum & 0xffff);
760
761 /* Return delta checksum to next stage, if any. */
762 return (csum);
763
764 update_udp_header:
765 tlen = sizeof(*pa->udp) + payload_len;
766 /* Assign new UDP length and compute checksum delta. */
767 tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
768
769 /* Check if there is a UDP checksum. */
770 if (__predict_false(pa->udp->uh_sum != 0)) {
771 /* Compute new UDP checksum. */
772 csum = pa->udp->uh_sum + 0xffff - delta_sum +
773 0xffff - temp[0] + 0xffff - temp[2];
774 while (csum > 0xffff)
775 csum = (csum >> 16) + (csum & 0xffff);
776 /* Assign new UDP checksum. */
777 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
778 }
779
780 /* Compute all modififications affecting next checksum. */
781 csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
782 while (csum > 0xffff)
783 csum = (csum >> 16) + (csum & 0xffff);
784
785 /* Return delta checksum to next stage, if any. */
786 return (csum);
787 }
788
789 static void
tcp_flush_out_entry(struct lro_ctrl * lc,struct lro_entry * le)790 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
791 {
792 /* Check if we need to recompute any checksums. */
793 if (le->needs_merge) {
794 uint16_t csum;
795
796 switch (le->inner.data.lro_type) {
797 case LRO_TYPE_IPV4_TCP:
798 csum = tcp_lro_update_checksum(&le->inner, le,
799 le->m_head->m_pkthdr.lro_tcp_d_len,
800 le->m_head->m_pkthdr.lro_tcp_d_csum);
801 csum = tcp_lro_update_checksum(&le->outer, NULL,
802 le->m_head->m_pkthdr.lro_tcp_d_len +
803 le->inner.total_hdr_len, csum);
804 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
805 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
806 le->m_head->m_pkthdr.csum_data = 0xffff;
807 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
808 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
809 break;
810 case LRO_TYPE_IPV6_TCP:
811 csum = tcp_lro_update_checksum(&le->inner, le,
812 le->m_head->m_pkthdr.lro_tcp_d_len,
813 le->m_head->m_pkthdr.lro_tcp_d_csum);
814 csum = tcp_lro_update_checksum(&le->outer, NULL,
815 le->m_head->m_pkthdr.lro_tcp_d_len +
816 le->inner.total_hdr_len, csum);
817 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
818 CSUM_PSEUDO_HDR;
819 le->m_head->m_pkthdr.csum_data = 0xffff;
820 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
821 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
822 break;
823 case LRO_TYPE_NONE:
824 switch (le->outer.data.lro_type) {
825 case LRO_TYPE_IPV4_TCP:
826 csum = tcp_lro_update_checksum(&le->outer, le,
827 le->m_head->m_pkthdr.lro_tcp_d_len,
828 le->m_head->m_pkthdr.lro_tcp_d_csum);
829 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
830 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
831 le->m_head->m_pkthdr.csum_data = 0xffff;
832 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
833 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
834 break;
835 case LRO_TYPE_IPV6_TCP:
836 csum = tcp_lro_update_checksum(&le->outer, le,
837 le->m_head->m_pkthdr.lro_tcp_d_len,
838 le->m_head->m_pkthdr.lro_tcp_d_csum);
839 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
840 CSUM_PSEUDO_HDR;
841 le->m_head->m_pkthdr.csum_data = 0xffff;
842 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
843 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
844 break;
845 default:
846 break;
847 }
848 break;
849 default:
850 break;
851 }
852 }
853
854 /*
855 * Break any chain, this is not set to NULL on the singleton
856 * case m_nextpkt points to m_head. Other case set them
857 * m_nextpkt to NULL in push_and_replace.
858 */
859 le->m_head->m_nextpkt = NULL;
860 lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
861 (*lc->ifp->if_input)(lc->ifp, le->m_head);
862 }
863
864 static void
tcp_set_entry_to_mbuf(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m,struct tcphdr * th)865 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
866 struct mbuf *m, struct tcphdr *th)
867 {
868 uint32_t *ts_ptr;
869 uint16_t tcp_data_len;
870 uint16_t tcp_opt_len;
871
872 ts_ptr = (uint32_t *)(th + 1);
873 tcp_opt_len = (th->th_off << 2);
874 tcp_opt_len -= sizeof(*th);
875
876 /* Check if there is a timestamp option. */
877 if (tcp_opt_len == 0 ||
878 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
879 *ts_ptr != TCP_LRO_TS_OPTION)) {
880 /* We failed to find the timestamp option. */
881 le->timestamp = 0;
882 } else {
883 le->timestamp = 1;
884 le->tsval = ntohl(*(ts_ptr + 1));
885 le->tsecr = *(ts_ptr + 2);
886 }
887
888 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
889
890 /* Pull out TCP sequence numbers and window size. */
891 le->next_seq = ntohl(th->th_seq) + tcp_data_len;
892 le->ack_seq = th->th_ack;
893 le->window = th->th_win;
894 le->flags = tcp_get_flags(th);
895 le->needs_merge = 0;
896
897 /* Setup new data pointers. */
898 le->m_head = m;
899 le->m_tail = m_last(m);
900 }
901
902 static void
tcp_push_and_replace(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m)903 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
904 {
905 struct lro_parser *pa;
906
907 /*
908 * Push up the stack of the current entry
909 * and replace it with "m".
910 */
911 struct mbuf *msave;
912
913 /* Grab off the next and save it */
914 msave = le->m_head->m_nextpkt;
915 le->m_head->m_nextpkt = NULL;
916
917 /* Now push out the old entry */
918 tcp_flush_out_entry(lc, le);
919
920 /* Re-parse new header, should not fail. */
921 pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
922 KASSERT(pa != NULL,
923 ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
924
925 /*
926 * Now to replace the data properly in the entry
927 * we have to reset the TCP header and
928 * other fields.
929 */
930 tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
931
932 /* Restore the next list */
933 m->m_nextpkt = msave;
934 }
935
936 static void
tcp_lro_mbuf_append_pkthdr(struct lro_entry * le,const struct mbuf * p)937 tcp_lro_mbuf_append_pkthdr(struct lro_entry *le, const struct mbuf *p)
938 {
939 struct mbuf *m;
940 uint32_t csum;
941
942 m = le->m_head;
943 if (m->m_pkthdr.lro_nsegs == 1) {
944 /* Compute relative checksum. */
945 csum = p->m_pkthdr.lro_tcp_d_csum;
946 } else {
947 /* Merge TCP data checksums. */
948 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
949 (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
950 while (csum > 0xffff)
951 csum = (csum >> 16) + (csum & 0xffff);
952 }
953
954 /* Update various counters. */
955 m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
956 m->m_pkthdr.lro_tcp_d_csum = csum;
957 m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
958 m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
959 le->needs_merge = 1;
960 }
961
962 static void
tcp_lro_condense(struct lro_ctrl * lc,struct lro_entry * le)963 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
964 {
965 /*
966 * Walk through the mbuf chain we
967 * have on tap and compress/condense
968 * as required.
969 */
970 uint32_t *ts_ptr;
971 struct mbuf *m;
972 struct tcphdr *th;
973 uint32_t tcp_data_len_total;
974 uint32_t tcp_data_seg_total;
975 uint16_t tcp_data_len;
976 uint16_t tcp_opt_len;
977
978 /*
979 * First we must check the lead (m_head)
980 * we must make sure that it is *not*
981 * something that should be sent up
982 * right away (sack etc).
983 */
984 again:
985 m = le->m_head->m_nextpkt;
986 if (m == NULL) {
987 /* Just one left. */
988 return;
989 }
990
991 th = tcp_lro_get_th(m);
992 tcp_opt_len = (th->th_off << 2);
993 tcp_opt_len -= sizeof(*th);
994 ts_ptr = (uint32_t *)(th + 1);
995
996 if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
997 *ts_ptr != TCP_LRO_TS_OPTION)) {
998 /*
999 * Its not the timestamp. We can't
1000 * use this guy as the head.
1001 */
1002 le->m_head->m_nextpkt = m->m_nextpkt;
1003 tcp_push_and_replace(lc, le, m);
1004 goto again;
1005 }
1006 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1007 /*
1008 * Make sure that previously seen segments/ACKs are delivered
1009 * before this segment, e.g. FIN.
1010 */
1011 le->m_head->m_nextpkt = m->m_nextpkt;
1012 tcp_push_and_replace(lc, le, m);
1013 goto again;
1014 }
1015 while((m = le->m_head->m_nextpkt) != NULL) {
1016 /*
1017 * condense m into le, first
1018 * pull m out of the list.
1019 */
1020 le->m_head->m_nextpkt = m->m_nextpkt;
1021 m->m_nextpkt = NULL;
1022 /* Setup my data */
1023 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1024 th = tcp_lro_get_th(m);
1025 ts_ptr = (uint32_t *)(th + 1);
1026 tcp_opt_len = (th->th_off << 2);
1027 tcp_opt_len -= sizeof(*th);
1028 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1029 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1030
1031 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1032 tcp_data_len_total >= lc->lro_length_lim) {
1033 /* Flush now if appending will result in overflow. */
1034 tcp_push_and_replace(lc, le, m);
1035 goto again;
1036 }
1037 if (tcp_opt_len != 0 &&
1038 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1039 *ts_ptr != TCP_LRO_TS_OPTION)) {
1040 /*
1041 * Maybe a sack in the new one? We need to
1042 * start all over after flushing the
1043 * current le. We will go up to the beginning
1044 * and flush it (calling the replace again possibly
1045 * or just returning).
1046 */
1047 tcp_push_and_replace(lc, le, m);
1048 goto again;
1049 }
1050 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1051 tcp_push_and_replace(lc, le, m);
1052 goto again;
1053 }
1054 if (tcp_opt_len != 0) {
1055 uint32_t tsval = ntohl(*(ts_ptr + 1));
1056 /* Make sure timestamp values are increasing. */
1057 if (TSTMP_GT(le->tsval, tsval)) {
1058 tcp_push_and_replace(lc, le, m);
1059 goto again;
1060 }
1061 le->tsval = tsval;
1062 le->tsecr = *(ts_ptr + 2);
1063 }
1064 /* Try to append the new segment. */
1065 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1066 ((tcp_get_flags(th) & TH_ACK) !=
1067 (le->flags & TH_ACK)) ||
1068 (tcp_data_len == 0 &&
1069 le->ack_seq == th->th_ack &&
1070 le->window == th->th_win))) {
1071 /* Out of order packet, non-ACK + ACK or dup ACK. */
1072 tcp_push_and_replace(lc, le, m);
1073 goto again;
1074 }
1075 if (tcp_data_len != 0 ||
1076 SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1077 le->next_seq += tcp_data_len;
1078 le->ack_seq = th->th_ack;
1079 le->window = th->th_win;
1080 le->needs_merge = 1;
1081 } else if (th->th_ack == le->ack_seq) {
1082 if (WIN_GT(th->th_win, le->window)) {
1083 le->window = th->th_win;
1084 le->needs_merge = 1;
1085 }
1086 }
1087
1088 if (tcp_data_len == 0) {
1089 m_freem(m);
1090 continue;
1091 }
1092
1093 /* Merge TCP data checksum and length to head mbuf. */
1094 tcp_lro_mbuf_append_pkthdr(le, m);
1095
1096 /*
1097 * Adjust the mbuf so that m_data points to the first byte of
1098 * the ULP payload. Adjust the mbuf to avoid complications and
1099 * append new segment to existing mbuf chain.
1100 */
1101 m_adj(m, m->m_pkthdr.len - tcp_data_len);
1102 m_demote_pkthdr(m);
1103 le->m_tail->m_next = m;
1104 le->m_tail = m_last(m);
1105 }
1106 }
1107
1108 static void
tcp_lro_flush(struct lro_ctrl * lc,struct lro_entry * le)1109 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1110 {
1111
1112 /* Only optimise if there are multiple packets waiting. */
1113 NET_EPOCH_ASSERT();
1114 if (tcp_lro_flush_tcphpts == NULL ||
1115 tcp_lro_flush_tcphpts(lc, le) != 0) {
1116 tcp_lro_condense(lc, le);
1117 tcp_flush_out_entry(lc, le);
1118 }
1119 lc->lro_flushed++;
1120 bzero(le, sizeof(*le));
1121 LIST_INSERT_HEAD(&lc->lro_free, le, next);
1122 }
1123
1124 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1125
1126 /*
1127 * The tcp_lro_sort() routine is comparable to qsort(), except it has
1128 * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1129 * number of elements to sort and 64 is the number of sequence bits
1130 * available. The algorithm is bit-slicing the 64-bit sequence number,
1131 * sorting one bit at a time from the most significant bit until the
1132 * least significant one, skipping the constant bits. This is
1133 * typically called a radix sort.
1134 */
1135 static void
tcp_lro_sort(struct lro_mbuf_sort * parray,uint32_t size)1136 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1137 {
1138 struct lro_mbuf_sort temp;
1139 uint64_t ones;
1140 uint64_t zeros;
1141 uint32_t x;
1142 uint32_t y;
1143
1144 repeat:
1145 /* for small arrays insertion sort is faster */
1146 if (size <= 12) {
1147 for (x = 1; x < size; x++) {
1148 temp = parray[x];
1149 for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1150 parray[y] = parray[y - 1];
1151 parray[y] = temp;
1152 }
1153 return;
1154 }
1155
1156 /* compute sequence bits which are constant */
1157 ones = 0;
1158 zeros = 0;
1159 for (x = 0; x != size; x++) {
1160 ones |= parray[x].seq;
1161 zeros |= ~parray[x].seq;
1162 }
1163
1164 /* compute bits which are not constant into "ones" */
1165 ones &= zeros;
1166 if (ones == 0)
1167 return;
1168
1169 /* pick the most significant bit which is not constant */
1170 ones = tcp_lro_msb_64(ones);
1171
1172 /*
1173 * Move entries having cleared sequence bits to the beginning
1174 * of the array:
1175 */
1176 for (x = y = 0; y != size; y++) {
1177 /* skip set bits */
1178 if (parray[y].seq & ones)
1179 continue;
1180 /* swap entries */
1181 temp = parray[x];
1182 parray[x] = parray[y];
1183 parray[y] = temp;
1184 x++;
1185 }
1186
1187 KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1188
1189 /* sort zeros */
1190 tcp_lro_sort(parray, x);
1191
1192 /* sort ones */
1193 parray += x;
1194 size -= x;
1195 goto repeat;
1196 }
1197
1198 void
tcp_lro_flush_all(struct lro_ctrl * lc)1199 tcp_lro_flush_all(struct lro_ctrl *lc)
1200 {
1201 uint64_t seq;
1202 uint64_t nseq;
1203 unsigned x;
1204
1205 NET_EPOCH_ASSERT();
1206 /* check if no mbufs to flush */
1207 if (lc->lro_mbuf_count == 0)
1208 goto done;
1209 if (lc->lro_cpu_is_set == 0) {
1210 if (lc->lro_last_cpu == curcpu) {
1211 lc->lro_cnt_of_same_cpu++;
1212 /* Have we reached the threshold to declare a cpu? */
1213 if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1214 lc->lro_cpu_is_set = 1;
1215 } else {
1216 lc->lro_last_cpu = curcpu;
1217 lc->lro_cnt_of_same_cpu = 0;
1218 }
1219 }
1220 CURVNET_SET(lc->ifp->if_vnet);
1221
1222 /* get current time */
1223 binuptime(&lc->lro_last_queue_time);
1224
1225 /* sort all mbufs according to stream */
1226 tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1227
1228 /* input data into LRO engine, stream by stream */
1229 seq = 0;
1230 for (x = 0; x != lc->lro_mbuf_count; x++) {
1231 struct mbuf *mb;
1232
1233 /* get mbuf */
1234 mb = lc->lro_mbuf_data[x].mb;
1235
1236 /* get sequence number, masking away the packet index */
1237 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1238
1239 /* check for new stream */
1240 if (seq != nseq) {
1241 seq = nseq;
1242
1243 /* flush active streams */
1244 tcp_lro_rx_done(lc);
1245 }
1246
1247 /* add packet to LRO engine */
1248 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1249 /* Flush anything we have acummulated */
1250 tcp_lro_flush_active(lc);
1251 /* input packet to network layer */
1252 (*lc->ifp->if_input)(lc->ifp, mb);
1253 lc->lro_queued++;
1254 lc->lro_flushed++;
1255 }
1256 }
1257 CURVNET_RESTORE();
1258 done:
1259 /* flush active streams */
1260 tcp_lro_rx_done(lc);
1261 tcp_hpts_softclock();
1262 lc->lro_mbuf_count = 0;
1263 }
1264
1265 static struct lro_head *
tcp_lro_rx_get_bucket(struct lro_ctrl * lc,struct mbuf * m,struct lro_parser * parser)1266 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1267 {
1268 u_long hash;
1269
1270 if (M_HASHTYPE_ISHASH(m)) {
1271 hash = m->m_pkthdr.flowid;
1272 } else {
1273 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1274 hash += parser->data.raw[i];
1275 }
1276 return (&lc->lro_hash[hash % lc->lro_hashsz]);
1277 }
1278
1279 static int
tcp_lro_rx_common(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum,bool use_hash)1280 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1281 {
1282 struct lro_parser pi; /* inner address data */
1283 struct lro_parser po; /* outer address data */
1284 struct lro_parser *pa; /* current parser for TCP stream */
1285 struct lro_entry *le;
1286 struct lro_head *bucket;
1287 struct tcphdr *th;
1288 int tcp_data_len;
1289 int tcp_opt_len;
1290 int error;
1291 uint16_t tcp_data_sum;
1292
1293 #ifdef INET
1294 /* Quickly decide if packet cannot be LRO'ed */
1295 if (__predict_false(V_ipforwarding != 0))
1296 return (TCP_LRO_CANNOT);
1297 #endif
1298 #ifdef INET6
1299 /* Quickly decide if packet cannot be LRO'ed */
1300 if (__predict_false(V_ip6_forwarding != 0))
1301 return (TCP_LRO_CANNOT);
1302 #endif
1303 if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1304 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1305 (m->m_pkthdr.csum_data != 0xffff)) {
1306 /*
1307 * The checksum either did not have hardware offload
1308 * or it was a bad checksum. We can't LRO such
1309 * a packet.
1310 */
1311 counter_u64_add(tcp_bad_csums, 1);
1312 return (TCP_LRO_CANNOT);
1313 }
1314 /* We expect a contiguous header [eh, ip, tcp]. */
1315 pa = tcp_lro_parser(m, &po, &pi, true);
1316 if (__predict_false(pa == NULL))
1317 return (TCP_LRO_NOT_SUPPORTED);
1318
1319 /* We don't expect any padding. */
1320 error = tcp_lro_trim_mbuf_chain(m, pa);
1321 if (__predict_false(error != 0))
1322 return (error);
1323
1324 #ifdef INET
1325 switch (pa->data.lro_type) {
1326 case LRO_TYPE_IPV4_TCP:
1327 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1328 if (__predict_false(error != 0))
1329 return (error);
1330 break;
1331 default:
1332 break;
1333 }
1334 #endif
1335 /* If no hardware or arrival stamp on the packet add timestamp */
1336 if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1337 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1338 m->m_flags |= M_TSTMP_LRO;
1339 }
1340
1341 /* Get pointer to TCP header. */
1342 th = pa->tcp;
1343
1344 /* Don't process SYN packets. */
1345 if (__predict_false(tcp_get_flags(th) & TH_SYN))
1346 return (TCP_LRO_CANNOT);
1347
1348 /* Get total TCP header length and compute payload length. */
1349 tcp_opt_len = (th->th_off << 2);
1350 tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1351 (uint8_t *)m->m_data) - tcp_opt_len;
1352 tcp_opt_len -= sizeof(*th);
1353
1354 /* Don't process invalid TCP headers. */
1355 if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1356 return (TCP_LRO_CANNOT);
1357
1358 /* Compute TCP data only checksum. */
1359 if (tcp_data_len == 0)
1360 tcp_data_sum = 0; /* no data, no checksum */
1361 else if (__predict_false(csum != 0))
1362 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1363 else
1364 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1365
1366 /* Save TCP info in mbuf. */
1367 m->m_nextpkt = NULL;
1368 m->m_pkthdr.rcvif = lc->ifp;
1369 m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1370 m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1371 m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1372 m->m_pkthdr.lro_nsegs = 1;
1373
1374 /* Get hash bucket. */
1375 if (!use_hash) {
1376 bucket = &lc->lro_hash[0];
1377 } else {
1378 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1379 }
1380
1381 /* Try to find a matching previous segment. */
1382 LIST_FOREACH(le, bucket, hash_next) {
1383 /* Compare addresses and ports. */
1384 if (lro_address_compare(&po.data, &le->outer.data) == false ||
1385 lro_address_compare(&pi.data, &le->inner.data) == false)
1386 continue;
1387
1388 /* Check if no data and old ACK. */
1389 if (tcp_data_len == 0 &&
1390 SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1391 m_freem(m);
1392 return (0);
1393 }
1394
1395 /* Mark "m" in the last spot. */
1396 le->m_last_mbuf->m_nextpkt = m;
1397 /* Now set the tail to "m". */
1398 le->m_last_mbuf = m;
1399 return (0);
1400 }
1401
1402 /* Try to find an empty slot. */
1403 if (LIST_EMPTY(&lc->lro_free))
1404 return (TCP_LRO_NO_ENTRIES);
1405
1406 /* Start a new segment chain. */
1407 le = LIST_FIRST(&lc->lro_free);
1408 LIST_REMOVE(le, next);
1409 tcp_lro_active_insert(lc, bucket, le);
1410
1411 /* Make sure the headers are set. */
1412 le->inner = pi;
1413 le->outer = po;
1414
1415 /* Store time this entry was allocated. */
1416 le->alloc_time = lc->lro_last_queue_time;
1417
1418 tcp_set_entry_to_mbuf(lc, le, m, th);
1419
1420 /* Now set the tail to "m". */
1421 le->m_last_mbuf = m;
1422
1423 return (0);
1424 }
1425
1426 int
tcp_lro_rx(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum)1427 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1428 {
1429 int error;
1430
1431 if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1432 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1433 (m->m_pkthdr.csum_data != 0xffff)) {
1434 /*
1435 * The checksum either did not have hardware offload
1436 * or it was a bad checksum. We can't LRO such
1437 * a packet.
1438 */
1439 counter_u64_add(tcp_bad_csums, 1);
1440 return (TCP_LRO_CANNOT);
1441 }
1442 /* get current time */
1443 binuptime(&lc->lro_last_queue_time);
1444 CURVNET_SET(lc->ifp->if_vnet);
1445 error = tcp_lro_rx_common(lc, m, csum, true);
1446 if (__predict_false(error != 0)) {
1447 /*
1448 * Flush anything we have acummulated
1449 * ahead of this packet that can't
1450 * be LRO'd. This preserves order.
1451 */
1452 tcp_lro_flush_active(lc);
1453 }
1454 CURVNET_RESTORE();
1455
1456 return (error);
1457 }
1458
1459 void
tcp_lro_queue_mbuf(struct lro_ctrl * lc,struct mbuf * mb)1460 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
1461 {
1462 NET_EPOCH_ASSERT();
1463 /* sanity checks */
1464 if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
1465 lc->lro_mbuf_max == 0)) {
1466 /* packet drop */
1467 m_freem(mb);
1468 return;
1469 }
1470
1471 /* check if packet is not LRO capable */
1472 if (__predict_false((lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
1473 /* input packet to network layer */
1474 (*lc->ifp->if_input) (lc->ifp, mb);
1475 return;
1476 }
1477
1478 /* If no hardware or arrival stamp on the packet add timestamp */
1479 if ((tcplro_stacks_wanting_mbufq > 0) &&
1480 (tcp_less_accurate_lro_ts == 0) &&
1481 ((mb->m_flags & M_TSTMP) == 0)) {
1482 /* Add in an LRO time since no hardware */
1483 binuptime(&lc->lro_last_queue_time);
1484 mb->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1485 mb->m_flags |= M_TSTMP_LRO;
1486 }
1487
1488 /* create sequence number */
1489 lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
1490 (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
1491 (((uint64_t)mb->m_pkthdr.flowid) << 24) |
1492 ((uint64_t)lc->lro_mbuf_count);
1493
1494 /* enter mbuf */
1495 lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
1496
1497 /* flush if array is full */
1498 if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
1499 tcp_lro_flush_all(lc);
1500 }
1501
1502 /* end */
1503