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 "opt_inet.h"
36 #include "opt_inet6.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/kernel.h>
41 #include <sys/malloc.h>
42 #include <sys/mbuf.h>
43 #include <sys/socket.h>
44 #include <sys/socketvar.h>
45 #include <sys/sockbuf.h>
46 #include <sys/sysctl.h>
47 #include <sys/hash.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 void (*tcp_hpts_softclock)(void);
94
95 counter_u64_t tcp_inp_lro_direct_queue;
96 counter_u64_t tcp_inp_lro_wokeup_queue;
97 counter_u64_t tcp_inp_lro_compressed;
98 counter_u64_t tcp_inp_lro_locks_taken;
99 counter_u64_t tcp_extra_mbuf;
100 counter_u64_t tcp_would_have_but;
101 counter_u64_t tcp_comp_total;
102 counter_u64_t tcp_uncomp_total;
103 counter_u64_t tcp_bad_csums;
104
105 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
106 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
107 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
108 "default number of LRO entries");
109
110 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
111 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
112 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
113 "Number of interrupts in a row on the same CPU that will make us declare an 'affinity' cpu?");
114
115 static uint32_t tcp_less_accurate_lro_ts = 0;
116 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_less_accurate,
117 CTLFLAG_MPSAFE, &tcp_less_accurate_lro_ts, 0,
118 "Do we trade off efficency by doing less timestamp operations for time accuracy?");
119
120 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
121 &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
122 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
123 &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
124 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
125 &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
126 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
127 &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
128 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
129 &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
130 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
131 &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
132 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
133 &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
134 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
135 &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
136 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lro_badcsum, CTLFLAG_RD,
137 &tcp_bad_csums, "Number of packets that the common code saw with bad csums");
138
139 void
tcp_lro_reg_mbufq(void)140 tcp_lro_reg_mbufq(void)
141 {
142 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
143 }
144
145 void
tcp_lro_dereg_mbufq(void)146 tcp_lro_dereg_mbufq(void)
147 {
148 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
149 }
150
151 static __inline void
tcp_lro_active_insert(struct lro_ctrl * lc,struct lro_head * bucket,struct lro_entry * le)152 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
153 struct lro_entry *le)
154 {
155
156 LIST_INSERT_HEAD(&lc->lro_active, le, next);
157 LIST_INSERT_HEAD(bucket, le, hash_next);
158 }
159
160 static __inline void
tcp_lro_active_remove(struct lro_entry * le)161 tcp_lro_active_remove(struct lro_entry *le)
162 {
163
164 LIST_REMOVE(le, next); /* active list */
165 LIST_REMOVE(le, hash_next); /* hash bucket */
166 }
167
168 int
tcp_lro_init(struct lro_ctrl * lc)169 tcp_lro_init(struct lro_ctrl *lc)
170 {
171 return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
172 }
173
174 int
tcp_lro_init_args(struct lro_ctrl * lc,struct ifnet * ifp,unsigned lro_entries,unsigned lro_mbufs)175 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
176 unsigned lro_entries, unsigned lro_mbufs)
177 {
178 struct lro_entry *le;
179 size_t size;
180 unsigned i;
181
182 lc->lro_bad_csum = 0;
183 lc->lro_queued = 0;
184 lc->lro_flushed = 0;
185 lc->lro_mbuf_count = 0;
186 lc->lro_mbuf_max = lro_mbufs;
187 lc->lro_cnt = lro_entries;
188 lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
189 lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
190 lc->ifp = ifp;
191 LIST_INIT(&lc->lro_free);
192 LIST_INIT(&lc->lro_active);
193
194 /* Create hash table to accelerate entry lookup. */
195 struct hashalloc_args ha = {
196 .size = lro_entries,
197 .mtype = M_LRO,
198 .mflags = M_NOWAIT,
199 .type = HASH_TYPE_PRIME,
200 };
201 lc->lro_hash = hashalloc(&ha);
202 if (lc->lro_hash == NULL) {
203 memset(lc, 0, sizeof(*lc));
204 return (ENOMEM);
205 }
206 lc->lro_hashsz = ha.size;
207
208 /* compute size to allocate */
209 size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
210 (lro_entries * sizeof(*le));
211 lc->lro_mbuf_data = (struct lro_mbuf_sort *)
212 malloc(size, M_LRO, M_NOWAIT | M_ZERO);
213
214 /* check for out of memory */
215 if (lc->lro_mbuf_data == NULL) {
216 struct hashalloc_args ha = {
217 .size = lc->lro_hashsz,
218 .mtype = M_LRO,
219 };
220 hashfree(lc->lro_hash, &ha);
221 memset(lc, 0, sizeof(*lc));
222 return (ENOMEM);
223 }
224 /* compute offset for LRO entries */
225 le = (struct lro_entry *)
226 (lc->lro_mbuf_data + lro_mbufs);
227
228 /* setup linked list */
229 for (i = 0; i != lro_entries; i++)
230 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
231
232 return (0);
233 }
234
235 struct vxlan_header {
236 uint32_t vxlh_flags;
237 uint32_t vxlh_vni;
238 };
239
240 static inline void *
tcp_lro_low_level_parser(void * ptr,struct lro_parser * parser,bool update_data,bool is_vxlan,int mlen)241 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan, int mlen)
242 {
243 const struct ether_vlan_header *eh;
244 void *old;
245 uint16_t eth_type;
246
247 if (update_data)
248 memset(parser, 0, sizeof(*parser));
249
250 old = ptr;
251
252 if (is_vxlan) {
253 const struct vxlan_header *vxh;
254 vxh = ptr;
255 ptr = (uint8_t *)ptr + sizeof(*vxh);
256 if (update_data) {
257 parser->data.vxlan_vni =
258 vxh->vxlh_vni & htonl(0xffffff00);
259 }
260 }
261
262 eh = ptr;
263 if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
264 eth_type = eh->evl_proto;
265 if (update_data) {
266 /* strip priority and keep VLAN ID only */
267 parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
268 }
269 /* advance to next header */
270 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
271 mlen -= (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
272 } else {
273 eth_type = eh->evl_encap_proto;
274 /* advance to next header */
275 mlen -= ETHER_HDR_LEN;
276 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
277 }
278 if (__predict_false(mlen <= 0))
279 return (NULL);
280 switch (eth_type) {
281 #ifdef INET
282 case htons(ETHERTYPE_IP):
283 parser->ip4 = ptr;
284 if (__predict_false(mlen < sizeof(struct ip)))
285 return (NULL);
286 /* Ensure there are no IPv4 options. */
287 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
288 break;
289 /* .. and the packet is not fragmented. */
290 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
291 break;
292 /* .. and the packet has valid src/dst addrs */
293 if (__predict_false(parser->ip4->ip_src.s_addr == INADDR_ANY ||
294 parser->ip4->ip_dst.s_addr == INADDR_ANY))
295 break;
296 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
297 mlen -= sizeof(struct ip);
298 if (update_data) {
299 parser->data.s_addr.v4 = parser->ip4->ip_src;
300 parser->data.d_addr.v4 = parser->ip4->ip_dst;
301 }
302 switch (parser->ip4->ip_p) {
303 case IPPROTO_UDP:
304 if (__predict_false(mlen < sizeof(struct udphdr)))
305 return (NULL);
306 parser->udp = ptr;
307 if (update_data) {
308 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
309 parser->data.s_port = parser->udp->uh_sport;
310 parser->data.d_port = parser->udp->uh_dport;
311 } else {
312 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
313 }
314 ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
315 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
316 return (ptr);
317 case IPPROTO_TCP:
318 parser->tcp = ptr;
319 if (__predict_false(mlen < sizeof(struct tcphdr)))
320 return (NULL);
321 if (update_data) {
322 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
323 parser->data.s_port = parser->tcp->th_sport;
324 parser->data.d_port = parser->tcp->th_dport;
325 } else {
326 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
327 }
328 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
329 return (NULL);
330 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
331 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
332 return (ptr);
333 default:
334 break;
335 }
336 break;
337 #endif
338 #ifdef INET6
339 case htons(ETHERTYPE_IPV6):
340 parser->ip6 = ptr;
341 if (__predict_false(mlen < sizeof(struct ip6_hdr)))
342 return (NULL);
343 /* Ensure the packet has valid src/dst addrs */
344 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_src) ||
345 IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_dst)))
346 return (NULL);
347 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
348 if (update_data) {
349 parser->data.s_addr.v6 = parser->ip6->ip6_src;
350 parser->data.d_addr.v6 = parser->ip6->ip6_dst;
351 }
352 mlen -= sizeof(struct ip6_hdr);
353 switch (parser->ip6->ip6_nxt) {
354 case IPPROTO_UDP:
355 if (__predict_false(mlen < sizeof(struct udphdr)))
356 return (NULL);
357 parser->udp = ptr;
358 if (update_data) {
359 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
360 parser->data.s_port = parser->udp->uh_sport;
361 parser->data.d_port = parser->udp->uh_dport;
362 } else {
363 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
364 }
365 ptr = (uint8_t *)ptr + sizeof(*parser->udp);
366 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
367 return (ptr);
368 case IPPROTO_TCP:
369 if (__predict_false(mlen < sizeof(struct tcphdr)))
370 return (NULL);
371 parser->tcp = ptr;
372 if (update_data) {
373 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
374 parser->data.s_port = parser->tcp->th_sport;
375 parser->data.d_port = parser->tcp->th_dport;
376 } else {
377 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
378 }
379 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
380 return (NULL);
381 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
382 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
383 return (ptr);
384 default:
385 break;
386 }
387 break;
388 #endif
389 default:
390 break;
391 }
392 /* Invalid packet - cannot parse */
393 return (NULL);
394 }
395
396 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
397 CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
398
399 static inline struct lro_parser *
tcp_lro_parser(struct mbuf * m,struct lro_parser * po,struct lro_parser * pi,bool update_data)400 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
401 {
402 void *data_ptr;
403
404 /* Try to parse outer headers first. */
405 data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false, m->m_len);
406 if (data_ptr == NULL || po->total_hdr_len > m->m_len)
407 return (NULL);
408
409 if (update_data) {
410 /* Store VLAN ID, if any. */
411 if (__predict_false(m->m_flags & M_VLANTAG)) {
412 po->data.vlan_id =
413 htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
414 }
415 /* Store decrypted flag, if any. */
416 if (__predict_false((m->m_pkthdr.csum_flags &
417 CSUM_TLS_MASK) == CSUM_TLS_DECRYPTED))
418 po->data.lro_flags |= LRO_FLAG_DECRYPTED;
419 }
420
421 switch (po->data.lro_type) {
422 case LRO_TYPE_IPV4_UDP:
423 case LRO_TYPE_IPV6_UDP:
424 /* Check for VXLAN headers. */
425 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
426 break;
427
428 /* Try to parse inner headers. */
429 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true,
430 (m->m_len - ((caddr_t)data_ptr - m->m_data)));
431 if (data_ptr == NULL || (pi->total_hdr_len + po->total_hdr_len) > m->m_len)
432 break;
433
434 /* Verify supported header types. */
435 switch (pi->data.lro_type) {
436 case LRO_TYPE_IPV4_TCP:
437 case LRO_TYPE_IPV6_TCP:
438 return (pi);
439 default:
440 break;
441 }
442 break;
443 case LRO_TYPE_IPV4_TCP:
444 case LRO_TYPE_IPV6_TCP:
445 if (update_data)
446 memset(pi, 0, sizeof(*pi));
447 return (po);
448 default:
449 break;
450 }
451 return (NULL);
452 }
453
454 static inline int
tcp_lro_trim_mbuf_chain(struct mbuf * m,const struct lro_parser * po)455 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
456 {
457 int len;
458
459 switch (po->data.lro_type) {
460 #ifdef INET
461 case LRO_TYPE_IPV4_TCP:
462 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
463 ntohs(po->ip4->ip_len);
464 break;
465 #endif
466 #ifdef INET6
467 case LRO_TYPE_IPV6_TCP:
468 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
469 ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
470 break;
471 #endif
472 default:
473 return (TCP_LRO_CANNOT);
474 }
475
476 /*
477 * If the frame is padded beyond the end of the IP packet,
478 * then trim the extra bytes off:
479 */
480 if (__predict_true(m->m_pkthdr.len == len)) {
481 return (0);
482 } else if (m->m_pkthdr.len > len) {
483 m_adj(m, len - m->m_pkthdr.len);
484 return (0);
485 }
486 return (TCP_LRO_CANNOT);
487 }
488
489 static void
lro_free_mbuf_chain(struct mbuf * m)490 lro_free_mbuf_chain(struct mbuf *m)
491 {
492 struct mbuf *save;
493
494 while (m) {
495 save = m->m_nextpkt;
496 m->m_nextpkt = NULL;
497 m_freem(m);
498 m = save;
499 }
500 }
501
502 void
tcp_lro_free(struct lro_ctrl * lc)503 tcp_lro_free(struct lro_ctrl *lc)
504 {
505 struct lro_entry *le;
506 unsigned x;
507
508 /* reset LRO free list */
509 LIST_INIT(&lc->lro_free);
510
511 /* free active mbufs, if any */
512 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
513 tcp_lro_active_remove(le);
514 lro_free_mbuf_chain(le->m_head);
515 }
516
517 struct hashalloc_args ha = {
518 .size = lc->lro_hashsz,
519 .mtype = M_LRO,
520 };
521 hashfree(lc->lro_hash, &ha);
522 lc->lro_hash = NULL;
523 lc->lro_hashsz = 0;
524
525 /* free mbuf array, if any */
526 for (x = 0; x != lc->lro_mbuf_count; x++)
527 m_freem(lc->lro_mbuf_data[x].mb);
528 lc->lro_mbuf_count = 0;
529
530 /* free allocated memory, if any */
531 free(lc->lro_mbuf_data, M_LRO);
532 lc->lro_mbuf_data = NULL;
533 }
534
535 static uint16_t
tcp_lro_rx_csum_tcphdr(const struct tcphdr * th)536 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
537 {
538 const uint16_t *ptr;
539 uint32_t csum;
540 uint16_t len;
541
542 csum = -th->th_sum; /* exclude checksum field */
543 len = th->th_off;
544 ptr = (const uint16_t *)th;
545 while (len--) {
546 csum += *ptr;
547 ptr++;
548 csum += *ptr;
549 ptr++;
550 }
551 while (csum > 0xffff)
552 csum = (csum >> 16) + (csum & 0xffff);
553
554 return (csum);
555 }
556
557 static uint16_t
tcp_lro_rx_csum_data(const struct lro_parser * pa,uint16_t tcp_csum)558 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
559 {
560 uint32_t c;
561 uint16_t cs;
562
563 c = tcp_csum;
564
565 switch (pa->data.lro_type) {
566 #ifdef INET6
567 case LRO_TYPE_IPV6_TCP:
568 /* Compute full pseudo IPv6 header checksum. */
569 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
570 break;
571 #endif
572 #ifdef INET
573 case LRO_TYPE_IPV4_TCP:
574 /* Compute full pseudo IPv4 header checsum. */
575 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
576 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
577 break;
578 #endif
579 default:
580 cs = 0; /* Keep compiler happy. */
581 break;
582 }
583
584 /* Complement checksum. */
585 cs = ~cs;
586 c += cs;
587
588 /* Remove TCP header checksum. */
589 cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
590 c += cs;
591
592 /* Compute checksum remainder. */
593 while (c > 0xffff)
594 c = (c >> 16) + (c & 0xffff);
595
596 return (c);
597 }
598
599 static void
tcp_lro_rx_done(struct lro_ctrl * lc)600 tcp_lro_rx_done(struct lro_ctrl *lc)
601 {
602 struct lro_entry *le;
603
604 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
605 tcp_lro_active_remove(le);
606 tcp_lro_flush(lc, le);
607 }
608 }
609
610 static void
tcp_lro_flush_active(struct lro_ctrl * lc)611 tcp_lro_flush_active(struct lro_ctrl *lc)
612 {
613 struct lro_entry *le, *le_tmp;
614
615 /*
616 * Walk through the list of le entries, and
617 * any one that does have packets flush. This
618 * is called because we have an inbound packet
619 * (e.g. SYN) that has to have all others flushed
620 * in front of it. Note we have to do the remove
621 * because tcp_lro_flush() assumes that the entry
622 * is being freed. This is ok it will just get
623 * reallocated again like it was new.
624 */
625 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
626 if (le->m_head != NULL) {
627 tcp_lro_active_remove(le);
628 tcp_lro_flush(lc, le);
629 }
630 }
631 }
632
633 void
tcp_lro_flush_inactive(struct lro_ctrl * lc,const struct timeval * timeout)634 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
635 {
636 struct lro_entry *le, *le_tmp;
637 uint64_t now, tov;
638 struct bintime bt;
639
640 NET_EPOCH_ASSERT();
641 if (LIST_EMPTY(&lc->lro_active))
642 return;
643
644 /* get timeout time and current time in ns */
645 binuptime(&bt);
646 now = bintime2ns(&bt);
647 tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
648 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
649 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
650 tcp_lro_active_remove(le);
651 tcp_lro_flush(lc, le);
652 }
653 }
654 }
655
656 #ifdef INET
657 static int
tcp_lro_rx_ipv4(struct lro_ctrl * lc,struct mbuf * m,struct ip * ip4)658 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
659 {
660 uint16_t csum;
661
662 /* Legacy IP has a header checksum that needs to be correct. */
663 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
664 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
665 lc->lro_bad_csum++;
666 return (TCP_LRO_CANNOT);
667 }
668 } else {
669 csum = in_cksum_hdr(ip4);
670 if (__predict_false(csum != 0)) {
671 lc->lro_bad_csum++;
672 return (TCP_LRO_CANNOT);
673 }
674 }
675 return (0);
676 }
677 #endif
678
679 static inline void
tcp_lro_assign_and_checksum_16(uint16_t * ptr,uint16_t value,uint16_t * psum)680 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
681 {
682 uint32_t csum;
683
684 csum = 0xffff - *ptr + value;
685 while (csum > 0xffff)
686 csum = (csum >> 16) + (csum & 0xffff);
687 *ptr = value;
688 *psum = csum;
689 }
690
691 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)692 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
693 uint16_t payload_len, uint16_t delta_sum)
694 {
695 uint32_t csum;
696 uint16_t tlen;
697 uint16_t temp[5] = {};
698
699 switch (pa->data.lro_type) {
700 case LRO_TYPE_IPV4_TCP:
701 /* Compute new IPv4 length. */
702 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
703 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
704
705 /* Subtract delta from current IPv4 checksum. */
706 csum = pa->ip4->ip_sum + 0xffff - temp[0];
707 while (csum > 0xffff)
708 csum = (csum >> 16) + (csum & 0xffff);
709 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
710 goto update_tcp_header;
711
712 case LRO_TYPE_IPV6_TCP:
713 /* Compute new IPv6 length. */
714 tlen = (pa->tcp->th_off << 2) + payload_len;
715 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
716 goto update_tcp_header;
717
718 case LRO_TYPE_IPV4_UDP:
719 /* Compute new IPv4 length. */
720 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
721 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
722
723 /* Subtract delta from current IPv4 checksum. */
724 csum = pa->ip4->ip_sum + 0xffff - temp[0];
725 while (csum > 0xffff)
726 csum = (csum >> 16) + (csum & 0xffff);
727 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
728 goto update_udp_header;
729
730 case LRO_TYPE_IPV6_UDP:
731 /* Compute new IPv6 length. */
732 tlen = sizeof(*pa->udp) + payload_len;
733 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
734 goto update_udp_header;
735
736 default:
737 return (0);
738 }
739
740 update_tcp_header:
741 /* Compute current TCP header checksum. */
742 temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
743
744 /* Incorporate the latest ACK into the TCP header. */
745 pa->tcp->th_ack = le->ack_seq;
746 pa->tcp->th_win = le->window;
747
748 /* Incorporate latest timestamp into the TCP header. */
749 if (le->timestamp != 0) {
750 uint32_t *ts_ptr;
751
752 ts_ptr = (uint32_t *)(pa->tcp + 1);
753 ts_ptr[1] = htonl(le->tsval);
754 ts_ptr[2] = le->tsecr;
755 }
756
757 /* Compute new TCP header checksum. */
758 temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
759
760 /* Compute new TCP checksum. */
761 csum = pa->tcp->th_sum + 0xffff - delta_sum +
762 0xffff - temp[0] + 0xffff - temp[3] + temp[2];
763 while (csum > 0xffff)
764 csum = (csum >> 16) + (csum & 0xffff);
765
766 /* Assign new TCP checksum. */
767 tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
768
769 /* Compute all modififications affecting next checksum. */
770 csum = temp[0] + temp[1] + 0xffff - temp[2] +
771 temp[3] + temp[4] + delta_sum;
772 while (csum > 0xffff)
773 csum = (csum >> 16) + (csum & 0xffff);
774
775 /* Return delta checksum to next stage, if any. */
776 return (csum);
777
778 update_udp_header:
779 tlen = sizeof(*pa->udp) + payload_len;
780 /* Assign new UDP length and compute checksum delta. */
781 tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
782
783 /* Check if there is a UDP checksum. */
784 if (__predict_false(pa->udp->uh_sum != 0)) {
785 /* Compute new UDP checksum. */
786 csum = pa->udp->uh_sum + 0xffff - delta_sum +
787 0xffff - temp[0] + 0xffff - temp[2];
788 while (csum > 0xffff)
789 csum = (csum >> 16) + (csum & 0xffff);
790 /* Assign new UDP checksum. */
791 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
792 }
793
794 /* Compute all modififications affecting next checksum. */
795 csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
796 while (csum > 0xffff)
797 csum = (csum >> 16) + (csum & 0xffff);
798
799 /* Return delta checksum to next stage, if any. */
800 return (csum);
801 }
802
803 static void
tcp_flush_out_entry(struct lro_ctrl * lc,struct lro_entry * le)804 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
805 {
806 /* Check if we need to recompute any checksums. */
807 if (le->needs_merge) {
808 uint16_t csum;
809
810 switch (le->inner.data.lro_type) {
811 case LRO_TYPE_IPV4_TCP:
812 csum = tcp_lro_update_checksum(&le->inner, le,
813 le->m_head->m_pkthdr.lro_tcp_d_len,
814 le->m_head->m_pkthdr.lro_tcp_d_csum);
815 csum = tcp_lro_update_checksum(&le->outer, NULL,
816 le->m_head->m_pkthdr.lro_tcp_d_len +
817 le->inner.total_hdr_len, csum);
818 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
819 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
820 le->m_head->m_pkthdr.csum_data = 0xffff;
821 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
822 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
823 break;
824 case LRO_TYPE_IPV6_TCP:
825 csum = tcp_lro_update_checksum(&le->inner, le,
826 le->m_head->m_pkthdr.lro_tcp_d_len,
827 le->m_head->m_pkthdr.lro_tcp_d_csum);
828 csum = tcp_lro_update_checksum(&le->outer, NULL,
829 le->m_head->m_pkthdr.lro_tcp_d_len +
830 le->inner.total_hdr_len, csum);
831 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
832 CSUM_PSEUDO_HDR;
833 le->m_head->m_pkthdr.csum_data = 0xffff;
834 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
835 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
836 break;
837 case LRO_TYPE_NONE:
838 switch (le->outer.data.lro_type) {
839 case LRO_TYPE_IPV4_TCP:
840 csum = tcp_lro_update_checksum(&le->outer, le,
841 le->m_head->m_pkthdr.lro_tcp_d_len,
842 le->m_head->m_pkthdr.lro_tcp_d_csum);
843 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
844 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
845 le->m_head->m_pkthdr.csum_data = 0xffff;
846 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
847 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
848 break;
849 case LRO_TYPE_IPV6_TCP:
850 csum = tcp_lro_update_checksum(&le->outer, le,
851 le->m_head->m_pkthdr.lro_tcp_d_len,
852 le->m_head->m_pkthdr.lro_tcp_d_csum);
853 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
854 CSUM_PSEUDO_HDR;
855 le->m_head->m_pkthdr.csum_data = 0xffff;
856 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
857 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
858 break;
859 default:
860 break;
861 }
862 break;
863 default:
864 break;
865 }
866 }
867
868 /*
869 * Break any chain, this is not set to NULL on the singleton
870 * case m_nextpkt points to m_head. Other case set them
871 * m_nextpkt to NULL in push_and_replace.
872 */
873 le->m_head->m_nextpkt = NULL;
874 lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
875 (*lc->ifp->if_input)(lc->ifp, le->m_head);
876 }
877
878 static void
tcp_set_entry_to_mbuf(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m,struct tcphdr * th)879 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
880 struct mbuf *m, struct tcphdr *th)
881 {
882 uint32_t *ts_ptr;
883 uint16_t tcp_data_len;
884 uint16_t tcp_opt_len;
885
886 ts_ptr = (uint32_t *)(th + 1);
887 tcp_opt_len = (th->th_off << 2);
888 tcp_opt_len -= sizeof(*th);
889
890 /* Check if there is a timestamp option. */
891 if (tcp_opt_len == 0 ||
892 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
893 *ts_ptr != TCP_LRO_TS_OPTION)) {
894 /* We failed to find the timestamp option. */
895 le->timestamp = 0;
896 } else {
897 le->timestamp = 1;
898 le->tsval = ntohl(*(ts_ptr + 1));
899 le->tsecr = *(ts_ptr + 2);
900 }
901
902 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
903
904 /* Pull out TCP sequence numbers and window size. */
905 le->next_seq = ntohl(th->th_seq) + tcp_data_len;
906 le->ack_seq = th->th_ack;
907 le->window = th->th_win;
908 le->flags = tcp_get_flags(th);
909 le->needs_merge = 0;
910
911 /* Setup new data pointers. */
912 le->m_head = m;
913 le->m_tail = m_last(m);
914 }
915
916 static void
tcp_push_and_replace(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m)917 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
918 {
919 struct lro_parser *pa;
920
921 /*
922 * Push up the stack of the current entry
923 * and replace it with "m".
924 */
925 struct mbuf *msave;
926
927 /* Grab off the next and save it */
928 msave = le->m_head->m_nextpkt;
929 le->m_head->m_nextpkt = NULL;
930
931 /* Now push out the old entry */
932 tcp_flush_out_entry(lc, le);
933
934 /* Re-parse new header, should not fail. */
935 pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
936 KASSERT(pa != NULL,
937 ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
938
939 /*
940 * Now to replace the data properly in the entry
941 * we have to reset the TCP header and
942 * other fields.
943 */
944 tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
945
946 /* Restore the next list */
947 m->m_nextpkt = msave;
948 }
949
950 static void
tcp_lro_mbuf_append_pkthdr(struct lro_entry * le,const struct mbuf * p)951 tcp_lro_mbuf_append_pkthdr(struct lro_entry *le, const struct mbuf *p)
952 {
953 struct mbuf *m;
954 uint32_t csum;
955
956 m = le->m_head;
957 if (m->m_pkthdr.lro_nsegs == 1) {
958 /* Compute relative checksum. */
959 csum = p->m_pkthdr.lro_tcp_d_csum;
960 } else {
961 /* Merge TCP data checksums. */
962 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
963 (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
964 while (csum > 0xffff)
965 csum = (csum >> 16) + (csum & 0xffff);
966 }
967
968 /* Update various counters. */
969 m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
970 m->m_pkthdr.lro_tcp_d_csum = csum;
971 m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
972 m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
973 le->needs_merge = 1;
974 }
975
976 static void
tcp_lro_condense(struct lro_ctrl * lc,struct lro_entry * le)977 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
978 {
979 /*
980 * Walk through the mbuf chain we
981 * have on tap and compress/condense
982 * as required.
983 */
984 uint32_t *ts_ptr;
985 struct mbuf *m;
986 struct tcphdr *th;
987 uint32_t tcp_data_len_total;
988 uint32_t tcp_data_seg_total;
989 uint16_t tcp_data_len;
990 uint16_t tcp_opt_len;
991
992 /*
993 * First we must check the lead (m_head)
994 * we must make sure that it is *not*
995 * something that should be sent up
996 * right away (sack etc).
997 */
998 again:
999 m = le->m_head->m_nextpkt;
1000 if (m == NULL) {
1001 /* Just one left. */
1002 return;
1003 }
1004
1005 th = tcp_lro_get_th(m);
1006 tcp_opt_len = (th->th_off << 2);
1007 tcp_opt_len -= sizeof(*th);
1008 ts_ptr = (uint32_t *)(th + 1);
1009
1010 if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1011 *ts_ptr != TCP_LRO_TS_OPTION)) {
1012 /*
1013 * Its not the timestamp. We can't
1014 * use this guy as the head.
1015 */
1016 le->m_head->m_nextpkt = m->m_nextpkt;
1017 tcp_push_and_replace(lc, le, m);
1018 goto again;
1019 }
1020 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1021 /*
1022 * Make sure that previously seen segments/ACKs are delivered
1023 * before this segment, e.g. FIN.
1024 */
1025 le->m_head->m_nextpkt = m->m_nextpkt;
1026 tcp_push_and_replace(lc, le, m);
1027 goto again;
1028 }
1029 while((m = le->m_head->m_nextpkt) != NULL) {
1030 /*
1031 * condense m into le, first
1032 * pull m out of the list.
1033 */
1034 le->m_head->m_nextpkt = m->m_nextpkt;
1035 m->m_nextpkt = NULL;
1036 /* Setup my data */
1037 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1038 th = tcp_lro_get_th(m);
1039 ts_ptr = (uint32_t *)(th + 1);
1040 tcp_opt_len = (th->th_off << 2);
1041 tcp_opt_len -= sizeof(*th);
1042 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1043 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1044
1045 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1046 tcp_data_len_total >= lc->lro_length_lim) {
1047 /* Flush now if appending will result in overflow. */
1048 tcp_push_and_replace(lc, le, m);
1049 goto again;
1050 }
1051 if (tcp_opt_len != 0 &&
1052 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1053 *ts_ptr != TCP_LRO_TS_OPTION)) {
1054 /*
1055 * Maybe a sack in the new one? We need to
1056 * start all over after flushing the
1057 * current le. We will go up to the beginning
1058 * and flush it (calling the replace again possibly
1059 * or just returning).
1060 */
1061 tcp_push_and_replace(lc, le, m);
1062 goto again;
1063 }
1064 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1065 tcp_push_and_replace(lc, le, m);
1066 goto again;
1067 }
1068 if (tcp_opt_len != 0) {
1069 uint32_t tsval = ntohl(*(ts_ptr + 1));
1070 /* Make sure timestamp values are increasing. */
1071 if (TSTMP_GT(le->tsval, tsval)) {
1072 tcp_push_and_replace(lc, le, m);
1073 goto again;
1074 }
1075 le->tsval = tsval;
1076 le->tsecr = *(ts_ptr + 2);
1077 }
1078 /* Try to append the new segment. */
1079 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1080 ((tcp_get_flags(th) & TH_ACK) !=
1081 (le->flags & TH_ACK)) ||
1082 (tcp_data_len == 0 &&
1083 le->ack_seq == th->th_ack &&
1084 le->window == th->th_win))) {
1085 /* Out of order packet, non-ACK + ACK or dup ACK. */
1086 tcp_push_and_replace(lc, le, m);
1087 goto again;
1088 }
1089 if (tcp_data_len != 0 ||
1090 SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1091 le->next_seq += tcp_data_len;
1092 le->ack_seq = th->th_ack;
1093 le->window = th->th_win;
1094 le->needs_merge = 1;
1095 } else if (th->th_ack == le->ack_seq) {
1096 if (WIN_GT(th->th_win, le->window)) {
1097 le->window = th->th_win;
1098 le->needs_merge = 1;
1099 }
1100 }
1101
1102 if (tcp_data_len == 0) {
1103 m_freem(m);
1104 continue;
1105 }
1106
1107 /* Merge TCP data checksum and length to head mbuf. */
1108 tcp_lro_mbuf_append_pkthdr(le, m);
1109
1110 /*
1111 * Adjust the mbuf so that m_data points to the first byte of
1112 * the ULP payload. Adjust the mbuf to avoid complications and
1113 * append new segment to existing mbuf chain.
1114 */
1115 m_adj(m, m->m_pkthdr.len - tcp_data_len);
1116 m_demote_pkthdr(m);
1117 le->m_tail->m_next = m;
1118 le->m_tail = m_last(m);
1119 }
1120 }
1121
1122 static void
tcp_lro_flush(struct lro_ctrl * lc,struct lro_entry * le)1123 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1124 {
1125
1126 /* Only optimise if there are multiple packets waiting. */
1127 NET_EPOCH_ASSERT();
1128 if (tcp_lro_flush_tcphpts == NULL ||
1129 tcp_lro_flush_tcphpts(lc, le) != 0) {
1130 tcp_lro_condense(lc, le);
1131 tcp_flush_out_entry(lc, le);
1132 }
1133 lc->lro_flushed++;
1134 bzero(le, sizeof(*le));
1135 LIST_INSERT_HEAD(&lc->lro_free, le, next);
1136 }
1137
1138 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1139
1140 /*
1141 * The tcp_lro_sort() routine is comparable to qsort(), except it has
1142 * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1143 * number of elements to sort and 64 is the number of sequence bits
1144 * available. The algorithm is bit-slicing the 64-bit sequence number,
1145 * sorting one bit at a time from the most significant bit until the
1146 * least significant one, skipping the constant bits. This is
1147 * typically called a radix sort.
1148 */
1149 static void
tcp_lro_sort(struct lro_mbuf_sort * parray,uint32_t size)1150 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1151 {
1152 struct lro_mbuf_sort temp;
1153 uint64_t ones;
1154 uint64_t zeros;
1155 uint32_t x;
1156 uint32_t y;
1157
1158 repeat:
1159 /* for small arrays insertion sort is faster */
1160 if (size <= 12) {
1161 for (x = 1; x < size; x++) {
1162 temp = parray[x];
1163 for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1164 parray[y] = parray[y - 1];
1165 parray[y] = temp;
1166 }
1167 return;
1168 }
1169
1170 /* compute sequence bits which are constant */
1171 ones = 0;
1172 zeros = 0;
1173 for (x = 0; x != size; x++) {
1174 ones |= parray[x].seq;
1175 zeros |= ~parray[x].seq;
1176 }
1177
1178 /* compute bits which are not constant into "ones" */
1179 ones &= zeros;
1180 if (ones == 0)
1181 return;
1182
1183 /* pick the most significant bit which is not constant */
1184 ones = tcp_lro_msb_64(ones);
1185
1186 /*
1187 * Move entries having cleared sequence bits to the beginning
1188 * of the array:
1189 */
1190 for (x = y = 0; y != size; y++) {
1191 /* skip set bits */
1192 if (parray[y].seq & ones)
1193 continue;
1194 /* swap entries */
1195 temp = parray[x];
1196 parray[x] = parray[y];
1197 parray[y] = temp;
1198 x++;
1199 }
1200
1201 KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1202
1203 /* sort zeros */
1204 tcp_lro_sort(parray, x);
1205
1206 /* sort ones */
1207 parray += x;
1208 size -= x;
1209 goto repeat;
1210 }
1211
1212 void
tcp_lro_flush_all(struct lro_ctrl * lc)1213 tcp_lro_flush_all(struct lro_ctrl *lc)
1214 {
1215 uint64_t seq;
1216 uint64_t nseq;
1217 unsigned x;
1218
1219 NET_EPOCH_ASSERT();
1220 /* check if no mbufs to flush */
1221 if (lc->lro_mbuf_count == 0)
1222 goto done;
1223 if (lc->lro_cpu_is_set == 0) {
1224 if (lc->lro_last_cpu == curcpu) {
1225 lc->lro_cnt_of_same_cpu++;
1226 /* Have we reached the threshold to declare a cpu? */
1227 if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1228 lc->lro_cpu_is_set = 1;
1229 } else {
1230 lc->lro_last_cpu = curcpu;
1231 lc->lro_cnt_of_same_cpu = 0;
1232 }
1233 }
1234 CURVNET_SET(lc->ifp->if_vnet);
1235
1236 /* get current time */
1237 binuptime(&lc->lro_last_queue_time);
1238
1239 /* sort all mbufs according to stream */
1240 tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1241
1242 /* input data into LRO engine, stream by stream */
1243 seq = 0;
1244 for (x = 0; x != lc->lro_mbuf_count; x++) {
1245 struct mbuf *mb;
1246
1247 /* get mbuf */
1248 mb = lc->lro_mbuf_data[x].mb;
1249
1250 /* get sequence number, masking away the packet index */
1251 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1252
1253 /* check for new stream */
1254 if (seq != nseq) {
1255 seq = nseq;
1256
1257 /* flush active streams */
1258 tcp_lro_rx_done(lc);
1259 }
1260
1261 /* add packet to LRO engine */
1262 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1263 /* Flush anything we have acummulated */
1264 tcp_lro_flush_active(lc);
1265 /* input packet to network layer */
1266 (*lc->ifp->if_input)(lc->ifp, mb);
1267 lc->lro_queued++;
1268 lc->lro_flushed++;
1269 }
1270 }
1271 CURVNET_RESTORE();
1272 done:
1273 /* flush active streams */
1274 tcp_lro_rx_done(lc);
1275 if (tcp_hpts_softclock != NULL)
1276 tcp_hpts_softclock();
1277 lc->lro_mbuf_count = 0;
1278 }
1279
1280 static struct lro_head *
tcp_lro_rx_get_bucket(struct lro_ctrl * lc,struct mbuf * m,struct lro_parser * parser)1281 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1282 {
1283 u_long hash;
1284
1285 if (M_HASHTYPE_ISHASH(m)) {
1286 hash = m->m_pkthdr.flowid;
1287 } else {
1288 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1289 hash += parser->data.raw[i];
1290 }
1291 return (&lc->lro_hash[hash % lc->lro_hashsz]);
1292 }
1293
1294 static int
tcp_lro_rx_common(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum,bool use_hash)1295 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1296 {
1297 struct lro_parser pi; /* inner address data */
1298 struct lro_parser po; /* outer address data */
1299 struct lro_parser *pa; /* current parser for TCP stream */
1300 struct lro_entry *le;
1301 struct lro_head *bucket;
1302 struct tcphdr *th;
1303 int tcp_data_len;
1304 int tcp_opt_len;
1305 int error;
1306 uint16_t tcp_data_sum;
1307
1308 /* We expect a contiguous header [eh, ip, tcp]. */
1309 pa = tcp_lro_parser(m, &po, &pi, true);
1310 if (__predict_false(pa == NULL))
1311 return (TCP_LRO_NOT_SUPPORTED);
1312
1313 /* We don't expect any padding. */
1314 error = tcp_lro_trim_mbuf_chain(m, pa);
1315 if (__predict_false(error != 0))
1316 return (error);
1317
1318 #ifdef INET
1319 switch (pa->data.lro_type) {
1320 case LRO_TYPE_IPV4_TCP:
1321 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1322 if (__predict_false(error != 0))
1323 return (error);
1324 break;
1325 default:
1326 break;
1327 }
1328 #endif
1329 /* If no hardware or arrival stamp on the packet add timestamp */
1330 if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1331 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1332 m->m_flags |= M_TSTMP_LRO;
1333 }
1334
1335 /* Get pointer to TCP header. */
1336 th = pa->tcp;
1337
1338 /* Don't process SYN packets. */
1339 if (__predict_false(tcp_get_flags(th) & TH_SYN))
1340 return (TCP_LRO_CANNOT);
1341
1342 /* Get total TCP header length and compute payload length. */
1343 tcp_opt_len = (th->th_off << 2);
1344 tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1345 (uint8_t *)m->m_data) - tcp_opt_len;
1346 tcp_opt_len -= sizeof(*th);
1347
1348 /* Don't process invalid TCP headers. */
1349 if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1350 return (TCP_LRO_CANNOT);
1351
1352 /* Compute TCP data only checksum. */
1353 if (tcp_data_len == 0)
1354 tcp_data_sum = 0; /* no data, no checksum */
1355 else if (__predict_false(csum != 0))
1356 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1357 else
1358 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1359
1360 /* Save TCP info in mbuf. */
1361 m->m_nextpkt = NULL;
1362 m->m_pkthdr.rcvif = lc->ifp;
1363 m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1364 m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1365 m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1366 m->m_pkthdr.lro_nsegs = 1;
1367
1368 /* Get hash bucket. */
1369 if (!use_hash) {
1370 bucket = &lc->lro_hash[0];
1371 } else {
1372 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1373 }
1374
1375 /* Try to find a matching previous segment. */
1376 LIST_FOREACH(le, bucket, hash_next) {
1377 /* Compare addresses and ports. */
1378 if (lro_address_compare(&po.data, &le->outer.data) == false ||
1379 lro_address_compare(&pi.data, &le->inner.data) == false)
1380 continue;
1381
1382 /* Check if no data and old ACK. */
1383 if (tcp_data_len == 0 &&
1384 SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1385 m_freem(m);
1386 return (0);
1387 }
1388
1389 /* Mark "m" in the last spot. */
1390 le->m_last_mbuf->m_nextpkt = m;
1391 /* Now set the tail to "m". */
1392 le->m_last_mbuf = m;
1393 return (0);
1394 }
1395
1396 /* Try to find an empty slot. */
1397 if (LIST_EMPTY(&lc->lro_free))
1398 return (TCP_LRO_NO_ENTRIES);
1399
1400 /* Start a new segment chain. */
1401 le = LIST_FIRST(&lc->lro_free);
1402 LIST_REMOVE(le, next);
1403 tcp_lro_active_insert(lc, bucket, le);
1404
1405 /* Make sure the headers are set. */
1406 le->inner = pi;
1407 le->outer = po;
1408
1409 /* Store time this entry was allocated. */
1410 le->alloc_time = lc->lro_last_queue_time;
1411
1412 tcp_set_entry_to_mbuf(lc, le, m, th);
1413
1414 /* Now set the tail to "m". */
1415 le->m_last_mbuf = m;
1416
1417 return (0);
1418 }
1419
1420 int
tcp_lro_rx(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum)1421 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1422 {
1423 int error;
1424
1425 CURVNET_SET(lc->ifp->if_vnet);
1426 #ifdef INET
1427 /* Quickly decide if packet cannot be LRO'ed */
1428 if (__predict_false(V_ipforwarding != 0)) {
1429 CURVNET_RESTORE();
1430 return (TCP_LRO_CANNOT);
1431 }
1432 #endif
1433 #ifdef INET6
1434 /* Quickly decide if packet cannot be LRO'ed */
1435 if (__predict_false(V_ip6_forwarding != 0)) {
1436 CURVNET_RESTORE();
1437 return (TCP_LRO_CANNOT);
1438 }
1439 #endif
1440
1441 if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1442 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1443 (m->m_pkthdr.csum_data != 0xffff)) {
1444 /*
1445 * The checksum either did not have hardware offload
1446 * or it was a bad checksum. We can't LRO such
1447 * a packet.
1448 */
1449 counter_u64_add(tcp_bad_csums, 1);
1450 CURVNET_RESTORE();
1451 return (TCP_LRO_CANNOT);
1452 }
1453
1454 /* get current time */
1455 binuptime(&lc->lro_last_queue_time);
1456 error = tcp_lro_rx_common(lc, m, csum, true);
1457 if (__predict_false(error != 0)) {
1458 /*
1459 * Flush anything we have acummulated
1460 * ahead of this packet that can't
1461 * be LRO'd. This preserves order.
1462 */
1463 tcp_lro_flush_active(lc);
1464 }
1465 CURVNET_RESTORE();
1466
1467 return (error);
1468 }
1469
1470 void
tcp_lro_queue_mbuf(struct lro_ctrl * lc,struct mbuf * mb)1471 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
1472 {
1473 NET_EPOCH_ASSERT();
1474 /* sanity checks */
1475 if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
1476 lc->lro_mbuf_max == 0)) {
1477 /* packet drop */
1478 m_freem(mb);
1479 return;
1480 }
1481
1482 CURVNET_SET(lc->ifp->if_vnet);
1483 #ifdef INET
1484 /* Quickly decide if packet cannot be LRO'ed */
1485 if (__predict_false(V_ipforwarding != 0)) {
1486 /* input packet to network layer */
1487 CURVNET_RESTORE();
1488 (*lc->ifp->if_input) (lc->ifp, mb);
1489 return;
1490 }
1491 #endif
1492 #ifdef INET6
1493 /* Quickly decide if packet cannot be LRO'ed */
1494 if (__predict_false(V_ip6_forwarding != 0)) {
1495 /* input packet to network layer */
1496 CURVNET_RESTORE();
1497 (*lc->ifp->if_input) (lc->ifp, mb);
1498 return;
1499 }
1500 #endif
1501 CURVNET_RESTORE();
1502 /* check if packet is not LRO capable */
1503 if (__predict_false((lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
1504 /* input packet to network layer */
1505 (*lc->ifp->if_input) (lc->ifp, mb);
1506 return;
1507 }
1508
1509 if (((mb->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1510 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1511 (mb->m_pkthdr.csum_data != 0xffff)) {
1512 /*
1513 * The checksum either did not have hardware offload
1514 * or it was a bad checksum. We can't LRO such
1515 * a packet.
1516 */
1517 counter_u64_add(tcp_bad_csums, 1);
1518 (*lc->ifp->if_input) (lc->ifp, mb);
1519 return;
1520 }
1521
1522 /* If no hardware or arrival stamp on the packet add timestamp */
1523 if ((tcplro_stacks_wanting_mbufq > 0) &&
1524 (tcp_less_accurate_lro_ts == 0) &&
1525 ((mb->m_flags & M_TSTMP) == 0)) {
1526 /* Add in an LRO time since no hardware */
1527 binuptime(&lc->lro_last_queue_time);
1528 mb->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1529 mb->m_flags |= M_TSTMP_LRO;
1530 }
1531
1532 /* create sequence number */
1533 lc->lro_mbuf_data[lc->lro_mbuf_count].seq = lc->lro_mbuf_count;
1534 if (M_HASHTYPE_ISHASH(mb))
1535 lc->lro_mbuf_data[lc->lro_mbuf_count].seq |=
1536 (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
1537 (((uint64_t)mb->m_pkthdr.flowid) << 24);
1538
1539 /* enter mbuf */
1540 lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
1541
1542 /* flush if array is full */
1543 if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
1544 tcp_lro_flush_all(lc);
1545 }
1546
1547 /* end */
1548