1 /*-
2 * Copyright (c) 2007, Myricom Inc.
3 * Copyright (c) 2008, Intel Corporation.
4 * Copyright (c) 2012 The FreeBSD Foundation
5 * Copyright (c) 2016 Mellanox Technologies.
6 * All rights reserved.
7 *
8 * Portions of this software were developed by Bjoern Zeeb
9 * under sponsorship from the FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35
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/sysctl.h>
46
47 #include <net/if.h>
48 #include <net/if_var.h>
49 #include <net/ethernet.h>
50 #include <net/vnet.h>
51
52 #include <netinet/in_systm.h>
53 #include <netinet/in.h>
54 #include <netinet/ip6.h>
55 #include <netinet/ip.h>
56 #include <netinet/ip_var.h>
57 #include <netinet/tcp.h>
58 #include <netinet/tcp_seq.h>
59 #include <netinet/tcp_lro.h>
60 #include <netinet/tcp_var.h>
61
62 #include <netinet6/ip6_var.h>
63
64 #include <machine/in_cksum.h>
65
66 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
67
68 #define TCP_LRO_UPDATE_CSUM 1
69 #ifndef TCP_LRO_UPDATE_CSUM
70 #define TCP_LRO_INVALID_CSUM 0x0000
71 #endif
72
73 static void tcp_lro_rx_done(struct lro_ctrl *lc);
74
75 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
76 "TCP LRO");
77
78 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
79 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
80 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
81 "default number of LRO entries");
82
83 static __inline void
tcp_lro_active_insert(struct lro_ctrl * lc,struct lro_entry * le)84 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_entry *le)
85 {
86
87 LIST_INSERT_HEAD(&lc->lro_active, le, next);
88 }
89
90 static __inline void
tcp_lro_active_remove(struct lro_entry * le)91 tcp_lro_active_remove(struct lro_entry *le)
92 {
93
94 LIST_REMOVE(le, next);
95 }
96
97 int
tcp_lro_init(struct lro_ctrl * lc)98 tcp_lro_init(struct lro_ctrl *lc)
99 {
100 return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
101 }
102
103 int
tcp_lro_init_args(struct lro_ctrl * lc,struct ifnet * ifp,unsigned lro_entries,unsigned lro_mbufs)104 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
105 unsigned lro_entries, unsigned lro_mbufs)
106 {
107 struct lro_entry *le;
108 size_t size;
109 unsigned i;
110
111 lc->lro_bad_csum = 0;
112 lc->lro_queued = 0;
113 lc->lro_flushed = 0;
114 lc->lro_mbuf_count = 0;
115 lc->lro_mbuf_max = lro_mbufs;
116 lc->lro_cnt = lro_entries;
117 lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
118 lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
119 lc->ifp = ifp;
120 LIST_INIT(&lc->lro_free);
121 LIST_INIT(&lc->lro_active);
122
123 /* compute size to allocate */
124 size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
125 (lro_entries * sizeof(*le));
126 lc->lro_mbuf_data = (struct lro_mbuf_sort *)
127 malloc(size, M_LRO, M_NOWAIT | M_ZERO);
128
129 /* check for out of memory */
130 if (lc->lro_mbuf_data == NULL) {
131 memset(lc, 0, sizeof(*lc));
132 return (ENOMEM);
133 }
134 /* compute offset for LRO entries */
135 le = (struct lro_entry *)
136 (lc->lro_mbuf_data + lro_mbufs);
137
138 /* setup linked list */
139 for (i = 0; i != lro_entries; i++)
140 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
141
142 return (0);
143 }
144
145 void
tcp_lro_free(struct lro_ctrl * lc)146 tcp_lro_free(struct lro_ctrl *lc)
147 {
148 struct lro_entry *le;
149 unsigned x;
150
151 /* reset LRO free list */
152 LIST_INIT(&lc->lro_free);
153
154 /* free active mbufs, if any */
155 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
156 tcp_lro_active_remove(le);
157 m_freem(le->m_head);
158 }
159
160 /* free mbuf array, if any */
161 for (x = 0; x != lc->lro_mbuf_count; x++)
162 m_freem(lc->lro_mbuf_data[x].mb);
163 lc->lro_mbuf_count = 0;
164
165 /* free allocated memory, if any */
166 free(lc->lro_mbuf_data, M_LRO);
167 lc->lro_mbuf_data = NULL;
168 }
169
170 #ifdef TCP_LRO_UPDATE_CSUM
171 static uint16_t
tcp_lro_csum_th(struct tcphdr * th)172 tcp_lro_csum_th(struct tcphdr *th)
173 {
174 uint32_t ch;
175 uint16_t *p, l;
176
177 ch = th->th_sum = 0x0000;
178 l = th->th_off;
179 p = (uint16_t *)th;
180 while (l > 0) {
181 ch += *p;
182 p++;
183 ch += *p;
184 p++;
185 l--;
186 }
187 while (ch > 0xffff)
188 ch = (ch >> 16) + (ch & 0xffff);
189
190 return (ch & 0xffff);
191 }
192
193 static uint16_t
tcp_lro_rx_csum_fixup(struct lro_entry * le,void * l3hdr,struct tcphdr * th,uint16_t tcp_data_len,uint16_t csum)194 tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th,
195 uint16_t tcp_data_len, uint16_t csum)
196 {
197 uint32_t c;
198 uint16_t cs;
199
200 c = csum;
201
202 /* Remove length from checksum. */
203 switch (le->eh_type) {
204 #ifdef INET6
205 case ETHERTYPE_IPV6:
206 {
207 struct ip6_hdr *ip6;
208
209 ip6 = (struct ip6_hdr *)l3hdr;
210 if (le->append_cnt == 0)
211 cs = ip6->ip6_plen;
212 else {
213 uint32_t cx;
214
215 cx = ntohs(ip6->ip6_plen);
216 cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0);
217 }
218 break;
219 }
220 #endif
221 #ifdef INET
222 case ETHERTYPE_IP:
223 {
224 struct ip *ip4;
225
226 ip4 = (struct ip *)l3hdr;
227 if (le->append_cnt == 0)
228 cs = ip4->ip_len;
229 else {
230 cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4),
231 IPPROTO_TCP);
232 cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr,
233 htons(cs));
234 }
235 break;
236 }
237 #endif
238 default:
239 cs = 0; /* Keep compiler happy. */
240 }
241
242 cs = ~cs;
243 c += cs;
244
245 /* Remove TCP header csum. */
246 cs = ~tcp_lro_csum_th(th);
247 c += cs;
248 while (c > 0xffff)
249 c = (c >> 16) + (c & 0xffff);
250
251 return (c & 0xffff);
252 }
253 #endif
254
255 static void
tcp_lro_rx_done(struct lro_ctrl * lc)256 tcp_lro_rx_done(struct lro_ctrl *lc)
257 {
258 struct lro_entry *le;
259
260 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
261 tcp_lro_active_remove(le);
262 tcp_lro_flush(lc, le);
263 }
264 }
265
266 void
tcp_lro_flush_inactive(struct lro_ctrl * lc,const struct timeval * timeout)267 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
268 {
269 struct lro_entry *le, *le_tmp;
270 struct timeval tv;
271
272 if (LIST_EMPTY(&lc->lro_active))
273 return;
274
275 getmicrotime(&tv);
276 timevalsub(&tv, timeout);
277 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
278 if (timevalcmp(&tv, &le->mtime, >=)) {
279 tcp_lro_active_remove(le);
280 tcp_lro_flush(lc, le);
281 }
282 }
283 }
284
285 void
tcp_lro_flush(struct lro_ctrl * lc,struct lro_entry * le)286 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
287 {
288
289 if (le->append_cnt > 0) {
290 struct tcphdr *th;
291 uint16_t p_len;
292
293 p_len = htons(le->p_len);
294 switch (le->eh_type) {
295 #ifdef INET6
296 case ETHERTYPE_IPV6:
297 {
298 struct ip6_hdr *ip6;
299
300 ip6 = le->le_ip6;
301 ip6->ip6_plen = p_len;
302 th = (struct tcphdr *)(ip6 + 1);
303 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
304 CSUM_PSEUDO_HDR;
305 le->p_len += ETHER_HDR_LEN + sizeof(*ip6);
306 break;
307 }
308 #endif
309 #ifdef INET
310 case ETHERTYPE_IP:
311 {
312 struct ip *ip4;
313 #ifdef TCP_LRO_UPDATE_CSUM
314 uint32_t cl;
315 uint16_t c;
316 #endif
317
318 ip4 = le->le_ip4;
319 #ifdef TCP_LRO_UPDATE_CSUM
320 /* Fix IP header checksum for new length. */
321 c = ~ip4->ip_sum;
322 cl = c;
323 c = ~ip4->ip_len;
324 cl += c + p_len;
325 while (cl > 0xffff)
326 cl = (cl >> 16) + (cl & 0xffff);
327 c = cl;
328 ip4->ip_sum = ~c;
329 #else
330 ip4->ip_sum = TCP_LRO_INVALID_CSUM;
331 #endif
332 ip4->ip_len = p_len;
333 th = (struct tcphdr *)(ip4 + 1);
334 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
335 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
336 le->p_len += ETHER_HDR_LEN;
337 break;
338 }
339 #endif
340 default:
341 th = NULL; /* Keep compiler happy. */
342 }
343 le->m_head->m_pkthdr.csum_data = 0xffff;
344 le->m_head->m_pkthdr.len = le->p_len;
345
346 /* Incorporate the latest ACK into the TCP header. */
347 th->th_ack = le->ack_seq;
348 th->th_win = le->window;
349 /* Incorporate latest timestamp into the TCP header. */
350 if (le->timestamp != 0) {
351 uint32_t *ts_ptr;
352
353 ts_ptr = (uint32_t *)(th + 1);
354 ts_ptr[1] = htonl(le->tsval);
355 ts_ptr[2] = le->tsecr;
356 }
357 #ifdef TCP_LRO_UPDATE_CSUM
358 /* Update the TCP header checksum. */
359 le->ulp_csum += p_len;
360 le->ulp_csum += tcp_lro_csum_th(th);
361 while (le->ulp_csum > 0xffff)
362 le->ulp_csum = (le->ulp_csum >> 16) +
363 (le->ulp_csum & 0xffff);
364 th->th_sum = (le->ulp_csum & 0xffff);
365 th->th_sum = ~th->th_sum;
366 #else
367 th->th_sum = TCP_LRO_INVALID_CSUM;
368 #endif
369 }
370
371 (*lc->ifp->if_input)(lc->ifp, le->m_head);
372 lc->lro_queued += le->append_cnt + 1;
373 lc->lro_flushed++;
374 bzero(le, sizeof(*le));
375 LIST_INSERT_HEAD(&lc->lro_free, le, next);
376 }
377
378 #ifdef HAVE_INLINE_FLSLL
379 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
380 #else
381 static inline uint64_t
tcp_lro_msb_64(uint64_t x)382 tcp_lro_msb_64(uint64_t x)
383 {
384 x |= (x >> 1);
385 x |= (x >> 2);
386 x |= (x >> 4);
387 x |= (x >> 8);
388 x |= (x >> 16);
389 x |= (x >> 32);
390 return (x & ~(x >> 1));
391 }
392 #endif
393
394 /*
395 * The tcp_lro_sort() routine is comparable to qsort(), except it has
396 * a worst case complexity limit of O(MIN(N,64)*N), where N is the
397 * number of elements to sort and 64 is the number of sequence bits
398 * available. The algorithm is bit-slicing the 64-bit sequence number,
399 * sorting one bit at a time from the most significant bit until the
400 * least significant one, skipping the constant bits. This is
401 * typically called a radix sort.
402 */
403 static void
tcp_lro_sort(struct lro_mbuf_sort * parray,uint32_t size)404 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
405 {
406 struct lro_mbuf_sort temp;
407 uint64_t ones;
408 uint64_t zeros;
409 uint32_t x;
410 uint32_t y;
411
412 repeat:
413 /* for small arrays insertion sort is faster */
414 if (size <= 12) {
415 for (x = 1; x < size; x++) {
416 temp = parray[x];
417 for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
418 parray[y] = parray[y - 1];
419 parray[y] = temp;
420 }
421 return;
422 }
423
424 /* compute sequence bits which are constant */
425 ones = 0;
426 zeros = 0;
427 for (x = 0; x != size; x++) {
428 ones |= parray[x].seq;
429 zeros |= ~parray[x].seq;
430 }
431
432 /* compute bits which are not constant into "ones" */
433 ones &= zeros;
434 if (ones == 0)
435 return;
436
437 /* pick the most significant bit which is not constant */
438 ones = tcp_lro_msb_64(ones);
439
440 /*
441 * Move entries having cleared sequence bits to the beginning
442 * of the array:
443 */
444 for (x = y = 0; y != size; y++) {
445 /* skip set bits */
446 if (parray[y].seq & ones)
447 continue;
448 /* swap entries */
449 temp = parray[x];
450 parray[x] = parray[y];
451 parray[y] = temp;
452 x++;
453 }
454
455 KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
456
457 /* sort zeros */
458 tcp_lro_sort(parray, x);
459
460 /* sort ones */
461 parray += x;
462 size -= x;
463 goto repeat;
464 }
465
466 void
tcp_lro_flush_all(struct lro_ctrl * lc)467 tcp_lro_flush_all(struct lro_ctrl *lc)
468 {
469 uint64_t seq;
470 uint64_t nseq;
471 unsigned x;
472
473 /* check if no mbufs to flush */
474 if (lc->lro_mbuf_count == 0)
475 goto done;
476
477 /* sort all mbufs according to stream */
478 tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
479
480 /* input data into LRO engine, stream by stream */
481 seq = 0;
482 for (x = 0; x != lc->lro_mbuf_count; x++) {
483 struct mbuf *mb;
484
485 /* get mbuf */
486 mb = lc->lro_mbuf_data[x].mb;
487
488 /* get sequence number, masking away the packet index */
489 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
490
491 /* check for new stream */
492 if (seq != nseq) {
493 seq = nseq;
494
495 /* flush active streams */
496 tcp_lro_rx_done(lc);
497 }
498
499 /* add packet to LRO engine */
500 if (tcp_lro_rx(lc, mb, 0) != 0) {
501 /* input packet to network layer */
502 (*lc->ifp->if_input)(lc->ifp, mb);
503 lc->lro_queued++;
504 lc->lro_flushed++;
505 }
506 }
507 done:
508 /* flush active streams */
509 tcp_lro_rx_done(lc);
510
511 lc->lro_mbuf_count = 0;
512 }
513
514 #ifdef INET6
515 static int
tcp_lro_rx_ipv6(struct lro_ctrl * lc,struct mbuf * m,struct ip6_hdr * ip6,struct tcphdr ** th)516 tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6,
517 struct tcphdr **th)
518 {
519
520 /* XXX-BZ we should check the flow-label. */
521
522 /* XXX-BZ We do not yet support ext. hdrs. */
523 if (ip6->ip6_nxt != IPPROTO_TCP)
524 return (TCP_LRO_NOT_SUPPORTED);
525
526 /* Find the TCP header. */
527 *th = (struct tcphdr *)(ip6 + 1);
528
529 return (0);
530 }
531 #endif
532
533 #ifdef INET
534 static int
tcp_lro_rx_ipv4(struct lro_ctrl * lc,struct mbuf * m,struct ip * ip4,struct tcphdr ** th)535 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4,
536 struct tcphdr **th)
537 {
538 int csum_flags;
539 uint16_t csum;
540
541 if (ip4->ip_p != IPPROTO_TCP)
542 return (TCP_LRO_NOT_SUPPORTED);
543
544 /* Ensure there are no options. */
545 if ((ip4->ip_hl << 2) != sizeof (*ip4))
546 return (TCP_LRO_CANNOT);
547
548 /* .. and the packet is not fragmented. */
549 if (ip4->ip_off & htons(IP_MF|IP_OFFMASK))
550 return (TCP_LRO_CANNOT);
551
552 /* Legacy IP has a header checksum that needs to be correct. */
553 csum_flags = m->m_pkthdr.csum_flags;
554 if (csum_flags & CSUM_IP_CHECKED) {
555 if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) {
556 lc->lro_bad_csum++;
557 return (TCP_LRO_CANNOT);
558 }
559 } else {
560 csum = in_cksum_hdr(ip4);
561 if (__predict_false((csum) != 0)) {
562 lc->lro_bad_csum++;
563 return (TCP_LRO_CANNOT);
564 }
565 }
566
567 /* Find the TCP header (we assured there are no IP options). */
568 *th = (struct tcphdr *)(ip4 + 1);
569
570 return (0);
571 }
572 #endif
573
574 int
tcp_lro_rx(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum)575 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
576 {
577 struct lro_entry *le;
578 struct ether_header *eh;
579 #ifdef INET6
580 struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */
581 #endif
582 #ifdef INET
583 struct ip *ip4 = NULL; /* Keep compiler happy. */
584 #endif
585 struct tcphdr *th;
586 void *l3hdr = NULL; /* Keep compiler happy. */
587 uint32_t *ts_ptr;
588 tcp_seq seq;
589 int error, ip_len, l;
590 uint16_t eh_type, tcp_data_len;
591 int force_flush = 0;
592
593 /* We expect a contiguous header [eh, ip, tcp]. */
594
595 eh = mtod(m, struct ether_header *);
596 eh_type = ntohs(eh->ether_type);
597 switch (eh_type) {
598 #ifdef INET6
599 case ETHERTYPE_IPV6:
600 {
601 CURVNET_SET(lc->ifp->if_vnet);
602 if (V_ip6_forwarding != 0) {
603 /* XXX-BZ stats but changing lro_ctrl is a problem. */
604 CURVNET_RESTORE();
605 return (TCP_LRO_CANNOT);
606 }
607 CURVNET_RESTORE();
608 l3hdr = ip6 = (struct ip6_hdr *)(eh + 1);
609 error = tcp_lro_rx_ipv6(lc, m, ip6, &th);
610 if (error != 0)
611 return (error);
612 tcp_data_len = ntohs(ip6->ip6_plen);
613 ip_len = sizeof(*ip6) + tcp_data_len;
614 break;
615 }
616 #endif
617 #ifdef INET
618 case ETHERTYPE_IP:
619 {
620 CURVNET_SET(lc->ifp->if_vnet);
621 if (V_ipforwarding != 0) {
622 /* XXX-BZ stats but changing lro_ctrl is a problem. */
623 CURVNET_RESTORE();
624 return (TCP_LRO_CANNOT);
625 }
626 CURVNET_RESTORE();
627 l3hdr = ip4 = (struct ip *)(eh + 1);
628 error = tcp_lro_rx_ipv4(lc, m, ip4, &th);
629 if (error != 0)
630 return (error);
631 ip_len = ntohs(ip4->ip_len);
632 tcp_data_len = ip_len - sizeof(*ip4);
633 break;
634 }
635 #endif
636 /* XXX-BZ what happens in case of VLAN(s)? */
637 default:
638 return (TCP_LRO_NOT_SUPPORTED);
639 }
640
641 /*
642 * If the frame is padded beyond the end of the IP packet, then we must
643 * trim the extra bytes off.
644 */
645 l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len);
646 if (l != 0) {
647 if (l < 0)
648 /* Truncated packet. */
649 return (TCP_LRO_CANNOT);
650
651 m_adj(m, -l);
652 }
653
654 /*
655 * Check TCP header constraints.
656 */
657 /* Ensure no bits set besides ACK or PSH. */
658 if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
659 if (th->th_flags & TH_SYN)
660 return (TCP_LRO_CANNOT);
661 /*
662 * Make sure that previously seen segements/ACKs are delivered
663 * before this segement, e.g. FIN.
664 */
665 force_flush = 1;
666 }
667
668 /* XXX-BZ We lose a ACK|PUSH flag concatenating multiple segments. */
669 /* XXX-BZ Ideally we'd flush on PUSH? */
670
671 /*
672 * Check for timestamps.
673 * Since the only option we handle are timestamps, we only have to
674 * handle the simple case of aligned timestamps.
675 */
676 l = (th->th_off << 2);
677 tcp_data_len -= l;
678 l -= sizeof(*th);
679 ts_ptr = (uint32_t *)(th + 1);
680 if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) ||
681 (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16|
682 TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP)))) {
683 /*
684 * Make sure that previously seen segements/ACKs are delivered
685 * before this segement.
686 */
687 force_flush = 1;
688 }
689
690 /* If the driver did not pass in the checksum, set it now. */
691 if (csum == 0x0000)
692 csum = th->th_sum;
693
694 seq = ntohl(th->th_seq);
695
696 /* Try to find a matching previous segment. */
697 LIST_FOREACH(le, &lc->lro_active, next) {
698 if (le->eh_type != eh_type)
699 continue;
700 if (le->source_port != th->th_sport ||
701 le->dest_port != th->th_dport)
702 continue;
703 switch (eh_type) {
704 #ifdef INET6
705 case ETHERTYPE_IPV6:
706 if (bcmp(&le->source_ip6, &ip6->ip6_src,
707 sizeof(struct in6_addr)) != 0 ||
708 bcmp(&le->dest_ip6, &ip6->ip6_dst,
709 sizeof(struct in6_addr)) != 0)
710 continue;
711 break;
712 #endif
713 #ifdef INET
714 case ETHERTYPE_IP:
715 if (le->source_ip4 != ip4->ip_src.s_addr ||
716 le->dest_ip4 != ip4->ip_dst.s_addr)
717 continue;
718 break;
719 #endif
720 }
721
722 if (force_flush) {
723 /* Timestamps mismatch; this is a FIN, etc */
724 tcp_lro_active_remove(le);
725 tcp_lro_flush(lc, le);
726 return (TCP_LRO_CANNOT);
727 }
728
729 /* Flush now if appending will result in overflow. */
730 if (le->p_len > (lc->lro_length_lim - tcp_data_len)) {
731 tcp_lro_active_remove(le);
732 tcp_lro_flush(lc, le);
733 break;
734 }
735
736 /* Try to append the new segment. */
737 if (__predict_false(seq != le->next_seq ||
738 (tcp_data_len == 0 &&
739 le->ack_seq == th->th_ack &&
740 le->window == th->th_win))) {
741 /* Out of order packet or duplicate ACK. */
742 tcp_lro_active_remove(le);
743 tcp_lro_flush(lc, le);
744 return (TCP_LRO_CANNOT);
745 }
746
747 if (l != 0) {
748 uint32_t tsval = ntohl(*(ts_ptr + 1));
749 /* Make sure timestamp values are increasing. */
750 /* XXX-BZ flip and use TSTMP_GEQ macro for this? */
751 if (__predict_false(le->tsval > tsval ||
752 *(ts_ptr + 2) == 0))
753 return (TCP_LRO_CANNOT);
754 le->tsval = tsval;
755 le->tsecr = *(ts_ptr + 2);
756 }
757 if (tcp_data_len || SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
758 le->next_seq += tcp_data_len;
759 le->ack_seq = th->th_ack;
760 le->window = th->th_win;
761 le->append_cnt++;
762 } else if (th->th_ack == le->ack_seq) {
763 le->window = WIN_MAX(le->window, th->th_win);
764 le->append_cnt++;
765 } else {
766 /* no data and old ack */
767 le->append_cnt++;
768 m_freem(m);
769 return (0);
770 }
771 #ifdef TCP_LRO_UPDATE_CSUM
772 le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th,
773 tcp_data_len, ~csum);
774 #endif
775
776 if (tcp_data_len == 0) {
777 m_freem(m);
778 /*
779 * Flush this LRO entry, if this ACK should not
780 * be further delayed.
781 */
782 if (le->append_cnt >= lc->lro_ackcnt_lim) {
783 tcp_lro_active_remove(le);
784 tcp_lro_flush(lc, le);
785 }
786 return (0);
787 }
788
789 le->p_len += tcp_data_len;
790
791 /*
792 * Adjust the mbuf so that m_data points to the first byte of
793 * the ULP payload. Adjust the mbuf to avoid complications and
794 * append new segment to existing mbuf chain.
795 */
796 m_adj(m, m->m_pkthdr.len - tcp_data_len);
797 m_demote_pkthdr(m);
798
799 le->m_tail->m_next = m;
800 le->m_tail = m_last(m);
801
802 /*
803 * If a possible next full length packet would cause an
804 * overflow, pro-actively flush now.
805 */
806 if (le->p_len > (lc->lro_length_lim - lc->ifp->if_mtu)) {
807 tcp_lro_active_remove(le);
808 tcp_lro_flush(lc, le);
809 } else
810 getmicrotime(&le->mtime);
811
812 return (0);
813 }
814
815 if (force_flush) {
816 /*
817 * Nothing to flush, but this segment can not be further
818 * aggregated/delayed.
819 */
820 return (TCP_LRO_CANNOT);
821 }
822
823 /* Try to find an empty slot. */
824 if (LIST_EMPTY(&lc->lro_free))
825 return (TCP_LRO_NO_ENTRIES);
826
827 /* Start a new segment chain. */
828 le = LIST_FIRST(&lc->lro_free);
829 LIST_REMOVE(le, next);
830 tcp_lro_active_insert(lc, le);
831 getmicrotime(&le->mtime);
832
833 /* Start filling in details. */
834 switch (eh_type) {
835 #ifdef INET6
836 case ETHERTYPE_IPV6:
837 le->le_ip6 = ip6;
838 le->source_ip6 = ip6->ip6_src;
839 le->dest_ip6 = ip6->ip6_dst;
840 le->eh_type = eh_type;
841 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6);
842 break;
843 #endif
844 #ifdef INET
845 case ETHERTYPE_IP:
846 le->le_ip4 = ip4;
847 le->source_ip4 = ip4->ip_src.s_addr;
848 le->dest_ip4 = ip4->ip_dst.s_addr;
849 le->eh_type = eh_type;
850 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN;
851 break;
852 #endif
853 }
854 le->source_port = th->th_sport;
855 le->dest_port = th->th_dport;
856
857 le->next_seq = seq + tcp_data_len;
858 le->ack_seq = th->th_ack;
859 le->window = th->th_win;
860 if (l != 0) {
861 le->timestamp = 1;
862 le->tsval = ntohl(*(ts_ptr + 1));
863 le->tsecr = *(ts_ptr + 2);
864 }
865
866 #ifdef TCP_LRO_UPDATE_CSUM
867 /*
868 * Do not touch the csum of the first packet. However save the
869 * "adjusted" checksum of just the source and destination addresses,
870 * the next header and the TCP payload. The length and TCP header
871 * parts may change, so we remove those from the saved checksum and
872 * re-add with final values on tcp_lro_flush() if needed.
873 */
874 KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n",
875 __func__, le, le->ulp_csum));
876
877 le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len,
878 ~csum);
879 th->th_sum = csum; /* Restore checksum on first packet. */
880 #endif
881
882 le->m_head = m;
883 le->m_tail = m_last(m);
884
885 return (0);
886 }
887
888 void
tcp_lro_queue_mbuf(struct lro_ctrl * lc,struct mbuf * mb)889 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
890 {
891 /* sanity checks */
892 if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
893 lc->lro_mbuf_max == 0)) {
894 /* packet drop */
895 m_freem(mb);
896 return;
897 }
898
899 /* check if packet is not LRO capable */
900 if (__predict_false(mb->m_pkthdr.csum_flags == 0 ||
901 (lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
902
903 /* input packet to network layer */
904 (*lc->ifp->if_input) (lc->ifp, mb);
905 return;
906 }
907
908 /* create sequence number */
909 lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
910 (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
911 (((uint64_t)mb->m_pkthdr.flowid) << 24) |
912 ((uint64_t)lc->lro_mbuf_count);
913
914 /* enter mbuf */
915 lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
916
917 /* flush if array is full */
918 if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
919 tcp_lro_flush_all(lc);
920 }
921
922 /* end */
923