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
87 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
88 "TCP LRO");
89
90 long tcplro_stacks_wanting_mbufq;
91 int (*tcp_lro_flush_tcphpts)(struct lro_ctrl *lc, struct lro_entry *le);
92
93 counter_u64_t tcp_inp_lro_direct_queue;
94 counter_u64_t tcp_inp_lro_wokeup_queue;
95 counter_u64_t tcp_inp_lro_compressed;
96 counter_u64_t tcp_inp_lro_locks_taken;
97 counter_u64_t tcp_extra_mbuf;
98 counter_u64_t tcp_would_have_but;
99 counter_u64_t tcp_comp_total;
100 counter_u64_t tcp_uncomp_total;
101 counter_u64_t tcp_bad_csums;
102
103 static unsigned tcp_lro_entries = TCP_LRO_ENTRIES;
104 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
105 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
106 "default number of LRO entries");
107
108 static uint32_t tcp_lro_cpu_set_thresh = TCP_LRO_CPU_DECLARATION_THRESH;
109 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_cpu_threshold,
110 CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_cpu_set_thresh, 0,
111 "Number of interrupts in a row on the same CPU that will make us declare an 'affinity' cpu?");
112
113 static uint32_t tcp_less_accurate_lro_ts = 0;
114 SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, lro_less_accurate,
115 CTLFLAG_MPSAFE, &tcp_less_accurate_lro_ts, 0,
116 "Do we trade off efficency by doing less timestamp operations for time accuracy?");
117
118 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
119 &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
120 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
121 &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
122 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
123 &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
124 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
125 &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
126 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
127 &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
128 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
129 &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
130 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
131 &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
132 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
133 &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
134 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lro_badcsum, CTLFLAG_RD,
135 &tcp_bad_csums, "Number of packets that the common code saw with bad csums");
136
137 void
tcp_lro_reg_mbufq(void)138 tcp_lro_reg_mbufq(void)
139 {
140 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
141 }
142
143 void
tcp_lro_dereg_mbufq(void)144 tcp_lro_dereg_mbufq(void)
145 {
146 atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
147 }
148
149 static __inline void
tcp_lro_active_insert(struct lro_ctrl * lc,struct lro_head * bucket,struct lro_entry * le)150 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
151 struct lro_entry *le)
152 {
153
154 LIST_INSERT_HEAD(&lc->lro_active, le, next);
155 LIST_INSERT_HEAD(bucket, le, hash_next);
156 }
157
158 static __inline void
tcp_lro_active_remove(struct lro_entry * le)159 tcp_lro_active_remove(struct lro_entry *le)
160 {
161
162 LIST_REMOVE(le, next); /* active list */
163 LIST_REMOVE(le, hash_next); /* hash bucket */
164 }
165
166 int
tcp_lro_init(struct lro_ctrl * lc)167 tcp_lro_init(struct lro_ctrl *lc)
168 {
169 return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
170 }
171
172 int
tcp_lro_init_args(struct lro_ctrl * lc,struct ifnet * ifp,unsigned lro_entries,unsigned lro_mbufs)173 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
174 unsigned lro_entries, unsigned lro_mbufs)
175 {
176 struct lro_entry *le;
177 size_t size;
178 unsigned i, elements;
179
180 lc->lro_bad_csum = 0;
181 lc->lro_queued = 0;
182 lc->lro_flushed = 0;
183 lc->lro_mbuf_count = 0;
184 lc->lro_mbuf_max = lro_mbufs;
185 lc->lro_cnt = lro_entries;
186 lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
187 lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
188 lc->ifp = ifp;
189 LIST_INIT(&lc->lro_free);
190 LIST_INIT(&lc->lro_active);
191
192 /* create hash table to accelerate entry lookup */
193 if (lro_entries > lro_mbufs)
194 elements = lro_entries;
195 else
196 elements = lro_mbufs;
197 lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
198 HASH_NOWAIT);
199 if (lc->lro_hash == NULL) {
200 memset(lc, 0, sizeof(*lc));
201 return (ENOMEM);
202 }
203
204 /* compute size to allocate */
205 size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
206 (lro_entries * sizeof(*le));
207 lc->lro_mbuf_data = (struct lro_mbuf_sort *)
208 malloc(size, M_LRO, M_NOWAIT | M_ZERO);
209
210 /* check for out of memory */
211 if (lc->lro_mbuf_data == NULL) {
212 free(lc->lro_hash, M_LRO);
213 memset(lc, 0, sizeof(*lc));
214 return (ENOMEM);
215 }
216 /* compute offset for LRO entries */
217 le = (struct lro_entry *)
218 (lc->lro_mbuf_data + lro_mbufs);
219
220 /* setup linked list */
221 for (i = 0; i != lro_entries; i++)
222 LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
223
224 return (0);
225 }
226
227 struct vxlan_header {
228 uint32_t vxlh_flags;
229 uint32_t vxlh_vni;
230 };
231
232 static inline void *
tcp_lro_low_level_parser(void * ptr,struct lro_parser * parser,bool update_data,bool is_vxlan,int mlen)233 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan, int mlen)
234 {
235 const struct ether_vlan_header *eh;
236 void *old;
237 uint16_t eth_type;
238
239 if (update_data)
240 memset(parser, 0, sizeof(*parser));
241
242 old = ptr;
243
244 if (is_vxlan) {
245 const struct vxlan_header *vxh;
246 vxh = ptr;
247 ptr = (uint8_t *)ptr + sizeof(*vxh);
248 if (update_data) {
249 parser->data.vxlan_vni =
250 vxh->vxlh_vni & htonl(0xffffff00);
251 }
252 }
253
254 eh = ptr;
255 if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
256 eth_type = eh->evl_proto;
257 if (update_data) {
258 /* strip priority and keep VLAN ID only */
259 parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
260 }
261 /* advance to next header */
262 ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
263 mlen -= (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
264 } else {
265 eth_type = eh->evl_encap_proto;
266 /* advance to next header */
267 mlen -= ETHER_HDR_LEN;
268 ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
269 }
270 if (__predict_false(mlen <= 0))
271 return (NULL);
272 switch (eth_type) {
273 #ifdef INET
274 case htons(ETHERTYPE_IP):
275 parser->ip4 = ptr;
276 if (__predict_false(mlen < sizeof(struct ip)))
277 return (NULL);
278 /* Ensure there are no IPv4 options. */
279 if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
280 break;
281 /* .. and the packet is not fragmented. */
282 if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
283 break;
284 /* .. and the packet has valid src/dst addrs */
285 if (__predict_false(parser->ip4->ip_src.s_addr == INADDR_ANY ||
286 parser->ip4->ip_dst.s_addr == INADDR_ANY))
287 break;
288 ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
289 mlen -= sizeof(struct ip);
290 if (update_data) {
291 parser->data.s_addr.v4 = parser->ip4->ip_src;
292 parser->data.d_addr.v4 = parser->ip4->ip_dst;
293 }
294 switch (parser->ip4->ip_p) {
295 case IPPROTO_UDP:
296 if (__predict_false(mlen < sizeof(struct udphdr)))
297 return (NULL);
298 parser->udp = ptr;
299 if (update_data) {
300 parser->data.lro_type = LRO_TYPE_IPV4_UDP;
301 parser->data.s_port = parser->udp->uh_sport;
302 parser->data.d_port = parser->udp->uh_dport;
303 } else {
304 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
305 }
306 ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
307 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
308 return (ptr);
309 case IPPROTO_TCP:
310 parser->tcp = ptr;
311 if (__predict_false(mlen < sizeof(struct tcphdr)))
312 return (NULL);
313 if (update_data) {
314 parser->data.lro_type = LRO_TYPE_IPV4_TCP;
315 parser->data.s_port = parser->tcp->th_sport;
316 parser->data.d_port = parser->tcp->th_dport;
317 } else {
318 MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
319 }
320 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
321 return (NULL);
322 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
323 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
324 return (ptr);
325 default:
326 break;
327 }
328 break;
329 #endif
330 #ifdef INET6
331 case htons(ETHERTYPE_IPV6):
332 parser->ip6 = ptr;
333 if (__predict_false(mlen < sizeof(struct ip6_hdr)))
334 return (NULL);
335 /* Ensure the packet has valid src/dst addrs */
336 if (__predict_false(IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_src) ||
337 IN6_IS_ADDR_UNSPECIFIED(&parser->ip6->ip6_dst)))
338 return (NULL);
339 ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
340 if (update_data) {
341 parser->data.s_addr.v6 = parser->ip6->ip6_src;
342 parser->data.d_addr.v6 = parser->ip6->ip6_dst;
343 }
344 mlen -= sizeof(struct ip6_hdr);
345 switch (parser->ip6->ip6_nxt) {
346 case IPPROTO_UDP:
347 if (__predict_false(mlen < sizeof(struct udphdr)))
348 return (NULL);
349 parser->udp = ptr;
350 if (update_data) {
351 parser->data.lro_type = LRO_TYPE_IPV6_UDP;
352 parser->data.s_port = parser->udp->uh_sport;
353 parser->data.d_port = parser->udp->uh_dport;
354 } else {
355 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
356 }
357 ptr = (uint8_t *)ptr + sizeof(*parser->udp);
358 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
359 return (ptr);
360 case IPPROTO_TCP:
361 if (__predict_false(mlen < sizeof(struct tcphdr)))
362 return (NULL);
363 parser->tcp = ptr;
364 if (update_data) {
365 parser->data.lro_type = LRO_TYPE_IPV6_TCP;
366 parser->data.s_port = parser->tcp->th_sport;
367 parser->data.d_port = parser->tcp->th_dport;
368 } else {
369 MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
370 }
371 if (__predict_false(mlen < (parser->tcp->th_off << 2)))
372 return (NULL);
373 ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
374 parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
375 return (ptr);
376 default:
377 break;
378 }
379 break;
380 #endif
381 default:
382 break;
383 }
384 /* Invalid packet - cannot parse */
385 return (NULL);
386 }
387
388 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
389 CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
390
391 static inline struct lro_parser *
tcp_lro_parser(struct mbuf * m,struct lro_parser * po,struct lro_parser * pi,bool update_data)392 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
393 {
394 void *data_ptr;
395
396 /* Try to parse outer headers first. */
397 data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false, m->m_len);
398 if (data_ptr == NULL || po->total_hdr_len > m->m_len)
399 return (NULL);
400
401 if (update_data) {
402 /* Store VLAN ID, if any. */
403 if (__predict_false(m->m_flags & M_VLANTAG)) {
404 po->data.vlan_id =
405 htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
406 }
407 /* Store decrypted flag, if any. */
408 if (__predict_false((m->m_pkthdr.csum_flags &
409 CSUM_TLS_MASK) == CSUM_TLS_DECRYPTED))
410 po->data.lro_flags |= LRO_FLAG_DECRYPTED;
411 }
412
413 switch (po->data.lro_type) {
414 case LRO_TYPE_IPV4_UDP:
415 case LRO_TYPE_IPV6_UDP:
416 /* Check for VXLAN headers. */
417 if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
418 break;
419
420 /* Try to parse inner headers. */
421 data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true,
422 (m->m_len - ((caddr_t)data_ptr - m->m_data)));
423 if (data_ptr == NULL || (pi->total_hdr_len + po->total_hdr_len) > m->m_len)
424 break;
425
426 /* Verify supported header types. */
427 switch (pi->data.lro_type) {
428 case LRO_TYPE_IPV4_TCP:
429 case LRO_TYPE_IPV6_TCP:
430 return (pi);
431 default:
432 break;
433 }
434 break;
435 case LRO_TYPE_IPV4_TCP:
436 case LRO_TYPE_IPV6_TCP:
437 if (update_data)
438 memset(pi, 0, sizeof(*pi));
439 return (po);
440 default:
441 break;
442 }
443 return (NULL);
444 }
445
446 static inline int
tcp_lro_trim_mbuf_chain(struct mbuf * m,const struct lro_parser * po)447 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
448 {
449 int len;
450
451 switch (po->data.lro_type) {
452 #ifdef INET
453 case LRO_TYPE_IPV4_TCP:
454 len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
455 ntohs(po->ip4->ip_len);
456 break;
457 #endif
458 #ifdef INET6
459 case LRO_TYPE_IPV6_TCP:
460 len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
461 ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
462 break;
463 #endif
464 default:
465 return (TCP_LRO_CANNOT);
466 }
467
468 /*
469 * If the frame is padded beyond the end of the IP packet,
470 * then trim the extra bytes off:
471 */
472 if (__predict_true(m->m_pkthdr.len == len)) {
473 return (0);
474 } else if (m->m_pkthdr.len > len) {
475 m_adj(m, len - m->m_pkthdr.len);
476 return (0);
477 }
478 return (TCP_LRO_CANNOT);
479 }
480
481 static void
lro_free_mbuf_chain(struct mbuf * m)482 lro_free_mbuf_chain(struct mbuf *m)
483 {
484 struct mbuf *save;
485
486 while (m) {
487 save = m->m_nextpkt;
488 m->m_nextpkt = NULL;
489 m_freem(m);
490 m = save;
491 }
492 }
493
494 void
tcp_lro_free(struct lro_ctrl * lc)495 tcp_lro_free(struct lro_ctrl *lc)
496 {
497 struct lro_entry *le;
498 unsigned x;
499
500 /* reset LRO free list */
501 LIST_INIT(&lc->lro_free);
502
503 /* free active mbufs, if any */
504 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
505 tcp_lro_active_remove(le);
506 lro_free_mbuf_chain(le->m_head);
507 }
508
509 /* free hash table */
510 free(lc->lro_hash, M_LRO);
511 lc->lro_hash = NULL;
512 lc->lro_hashsz = 0;
513
514 /* free mbuf array, if any */
515 for (x = 0; x != lc->lro_mbuf_count; x++)
516 m_freem(lc->lro_mbuf_data[x].mb);
517 lc->lro_mbuf_count = 0;
518
519 /* free allocated memory, if any */
520 free(lc->lro_mbuf_data, M_LRO);
521 lc->lro_mbuf_data = NULL;
522 }
523
524 static uint16_t
tcp_lro_rx_csum_tcphdr(const struct tcphdr * th)525 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
526 {
527 const uint16_t *ptr;
528 uint32_t csum;
529 uint16_t len;
530
531 csum = -th->th_sum; /* exclude checksum field */
532 len = th->th_off;
533 ptr = (const uint16_t *)th;
534 while (len--) {
535 csum += *ptr;
536 ptr++;
537 csum += *ptr;
538 ptr++;
539 }
540 while (csum > 0xffff)
541 csum = (csum >> 16) + (csum & 0xffff);
542
543 return (csum);
544 }
545
546 static uint16_t
tcp_lro_rx_csum_data(const struct lro_parser * pa,uint16_t tcp_csum)547 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
548 {
549 uint32_t c;
550 uint16_t cs;
551
552 c = tcp_csum;
553
554 switch (pa->data.lro_type) {
555 #ifdef INET6
556 case LRO_TYPE_IPV6_TCP:
557 /* Compute full pseudo IPv6 header checksum. */
558 cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
559 break;
560 #endif
561 #ifdef INET
562 case LRO_TYPE_IPV4_TCP:
563 /* Compute full pseudo IPv4 header checsum. */
564 cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
565 cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
566 break;
567 #endif
568 default:
569 cs = 0; /* Keep compiler happy. */
570 break;
571 }
572
573 /* Complement checksum. */
574 cs = ~cs;
575 c += cs;
576
577 /* Remove TCP header checksum. */
578 cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
579 c += cs;
580
581 /* Compute checksum remainder. */
582 while (c > 0xffff)
583 c = (c >> 16) + (c & 0xffff);
584
585 return (c);
586 }
587
588 static void
tcp_lro_rx_done(struct lro_ctrl * lc)589 tcp_lro_rx_done(struct lro_ctrl *lc)
590 {
591 struct lro_entry *le;
592
593 while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
594 tcp_lro_active_remove(le);
595 tcp_lro_flush(lc, le);
596 }
597 }
598
599 static void
tcp_lro_flush_active(struct lro_ctrl * lc)600 tcp_lro_flush_active(struct lro_ctrl *lc)
601 {
602 struct lro_entry *le;
603
604 /*
605 * Walk through the list of le entries, and
606 * any one that does have packets flush. This
607 * is called because we have an inbound packet
608 * (e.g. SYN) that has to have all others flushed
609 * in front of it. Note we have to do the remove
610 * because tcp_lro_flush() assumes that the entry
611 * is being freed. This is ok it will just get
612 * reallocated again like it was new.
613 */
614 LIST_FOREACH(le, &lc->lro_active, next) {
615 if (le->m_head != NULL) {
616 tcp_lro_active_remove(le);
617 tcp_lro_flush(lc, le);
618 }
619 }
620 }
621
622 void
tcp_lro_flush_inactive(struct lro_ctrl * lc,const struct timeval * timeout)623 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
624 {
625 struct lro_entry *le, *le_tmp;
626 uint64_t now, tov;
627 struct bintime bt;
628
629 NET_EPOCH_ASSERT();
630 if (LIST_EMPTY(&lc->lro_active))
631 return;
632
633 /* get timeout time and current time in ns */
634 binuptime(&bt);
635 now = bintime2ns(&bt);
636 tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
637 LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
638 if (now >= (bintime2ns(&le->alloc_time) + tov)) {
639 tcp_lro_active_remove(le);
640 tcp_lro_flush(lc, le);
641 }
642 }
643 }
644
645 #ifdef INET
646 static int
tcp_lro_rx_ipv4(struct lro_ctrl * lc,struct mbuf * m,struct ip * ip4)647 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
648 {
649 uint16_t csum;
650
651 /* Legacy IP has a header checksum that needs to be correct. */
652 if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
653 if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
654 lc->lro_bad_csum++;
655 return (TCP_LRO_CANNOT);
656 }
657 } else {
658 csum = in_cksum_hdr(ip4);
659 if (__predict_false(csum != 0)) {
660 lc->lro_bad_csum++;
661 return (TCP_LRO_CANNOT);
662 }
663 }
664 return (0);
665 }
666 #endif
667
668 static inline void
tcp_lro_assign_and_checksum_16(uint16_t * ptr,uint16_t value,uint16_t * psum)669 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
670 {
671 uint32_t csum;
672
673 csum = 0xffff - *ptr + value;
674 while (csum > 0xffff)
675 csum = (csum >> 16) + (csum & 0xffff);
676 *ptr = value;
677 *psum = csum;
678 }
679
680 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)681 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
682 uint16_t payload_len, uint16_t delta_sum)
683 {
684 uint32_t csum;
685 uint16_t tlen;
686 uint16_t temp[5] = {};
687
688 switch (pa->data.lro_type) {
689 case LRO_TYPE_IPV4_TCP:
690 /* Compute new IPv4 length. */
691 tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
692 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
693
694 /* Subtract delta from current IPv4 checksum. */
695 csum = pa->ip4->ip_sum + 0xffff - temp[0];
696 while (csum > 0xffff)
697 csum = (csum >> 16) + (csum & 0xffff);
698 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
699 goto update_tcp_header;
700
701 case LRO_TYPE_IPV6_TCP:
702 /* Compute new IPv6 length. */
703 tlen = (pa->tcp->th_off << 2) + payload_len;
704 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
705 goto update_tcp_header;
706
707 case LRO_TYPE_IPV4_UDP:
708 /* Compute new IPv4 length. */
709 tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
710 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
711
712 /* Subtract delta from current IPv4 checksum. */
713 csum = pa->ip4->ip_sum + 0xffff - temp[0];
714 while (csum > 0xffff)
715 csum = (csum >> 16) + (csum & 0xffff);
716 tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
717 goto update_udp_header;
718
719 case LRO_TYPE_IPV6_UDP:
720 /* Compute new IPv6 length. */
721 tlen = sizeof(*pa->udp) + payload_len;
722 tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
723 goto update_udp_header;
724
725 default:
726 return (0);
727 }
728
729 update_tcp_header:
730 /* Compute current TCP header checksum. */
731 temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
732
733 /* Incorporate the latest ACK into the TCP header. */
734 pa->tcp->th_ack = le->ack_seq;
735 pa->tcp->th_win = le->window;
736
737 /* Incorporate latest timestamp into the TCP header. */
738 if (le->timestamp != 0) {
739 uint32_t *ts_ptr;
740
741 ts_ptr = (uint32_t *)(pa->tcp + 1);
742 ts_ptr[1] = htonl(le->tsval);
743 ts_ptr[2] = le->tsecr;
744 }
745
746 /* Compute new TCP header checksum. */
747 temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
748
749 /* Compute new TCP checksum. */
750 csum = pa->tcp->th_sum + 0xffff - delta_sum +
751 0xffff - temp[0] + 0xffff - temp[3] + temp[2];
752 while (csum > 0xffff)
753 csum = (csum >> 16) + (csum & 0xffff);
754
755 /* Assign new TCP checksum. */
756 tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
757
758 /* Compute all modififications affecting next checksum. */
759 csum = temp[0] + temp[1] + 0xffff - temp[2] +
760 temp[3] + temp[4] + delta_sum;
761 while (csum > 0xffff)
762 csum = (csum >> 16) + (csum & 0xffff);
763
764 /* Return delta checksum to next stage, if any. */
765 return (csum);
766
767 update_udp_header:
768 tlen = sizeof(*pa->udp) + payload_len;
769 /* Assign new UDP length and compute checksum delta. */
770 tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
771
772 /* Check if there is a UDP checksum. */
773 if (__predict_false(pa->udp->uh_sum != 0)) {
774 /* Compute new UDP checksum. */
775 csum = pa->udp->uh_sum + 0xffff - delta_sum +
776 0xffff - temp[0] + 0xffff - temp[2];
777 while (csum > 0xffff)
778 csum = (csum >> 16) + (csum & 0xffff);
779 /* Assign new UDP checksum. */
780 tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
781 }
782
783 /* Compute all modififications affecting next checksum. */
784 csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
785 while (csum > 0xffff)
786 csum = (csum >> 16) + (csum & 0xffff);
787
788 /* Return delta checksum to next stage, if any. */
789 return (csum);
790 }
791
792 static void
tcp_flush_out_entry(struct lro_ctrl * lc,struct lro_entry * le)793 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
794 {
795 /* Check if we need to recompute any checksums. */
796 if (le->needs_merge) {
797 uint16_t csum;
798
799 switch (le->inner.data.lro_type) {
800 case LRO_TYPE_IPV4_TCP:
801 csum = tcp_lro_update_checksum(&le->inner, le,
802 le->m_head->m_pkthdr.lro_tcp_d_len,
803 le->m_head->m_pkthdr.lro_tcp_d_csum);
804 csum = tcp_lro_update_checksum(&le->outer, NULL,
805 le->m_head->m_pkthdr.lro_tcp_d_len +
806 le->inner.total_hdr_len, csum);
807 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
808 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
809 le->m_head->m_pkthdr.csum_data = 0xffff;
810 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
811 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
812 break;
813 case LRO_TYPE_IPV6_TCP:
814 csum = tcp_lro_update_checksum(&le->inner, le,
815 le->m_head->m_pkthdr.lro_tcp_d_len,
816 le->m_head->m_pkthdr.lro_tcp_d_csum);
817 csum = tcp_lro_update_checksum(&le->outer, NULL,
818 le->m_head->m_pkthdr.lro_tcp_d_len +
819 le->inner.total_hdr_len, csum);
820 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
821 CSUM_PSEUDO_HDR;
822 le->m_head->m_pkthdr.csum_data = 0xffff;
823 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
824 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
825 break;
826 case LRO_TYPE_NONE:
827 switch (le->outer.data.lro_type) {
828 case LRO_TYPE_IPV4_TCP:
829 csum = tcp_lro_update_checksum(&le->outer, le,
830 le->m_head->m_pkthdr.lro_tcp_d_len,
831 le->m_head->m_pkthdr.lro_tcp_d_csum);
832 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
833 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
834 le->m_head->m_pkthdr.csum_data = 0xffff;
835 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
836 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
837 break;
838 case LRO_TYPE_IPV6_TCP:
839 csum = tcp_lro_update_checksum(&le->outer, le,
840 le->m_head->m_pkthdr.lro_tcp_d_len,
841 le->m_head->m_pkthdr.lro_tcp_d_csum);
842 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
843 CSUM_PSEUDO_HDR;
844 le->m_head->m_pkthdr.csum_data = 0xffff;
845 if (__predict_false(le->outer.data.lro_flags & LRO_FLAG_DECRYPTED))
846 le->m_head->m_pkthdr.csum_flags |= CSUM_TLS_DECRYPTED;
847 break;
848 default:
849 break;
850 }
851 break;
852 default:
853 break;
854 }
855 }
856
857 /*
858 * Break any chain, this is not set to NULL on the singleton
859 * case m_nextpkt points to m_head. Other case set them
860 * m_nextpkt to NULL in push_and_replace.
861 */
862 le->m_head->m_nextpkt = NULL;
863 lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
864 (*lc->ifp->if_input)(lc->ifp, le->m_head);
865 }
866
867 static void
tcp_set_entry_to_mbuf(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m,struct tcphdr * th)868 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
869 struct mbuf *m, struct tcphdr *th)
870 {
871 uint32_t *ts_ptr;
872 uint16_t tcp_data_len;
873 uint16_t tcp_opt_len;
874
875 ts_ptr = (uint32_t *)(th + 1);
876 tcp_opt_len = (th->th_off << 2);
877 tcp_opt_len -= sizeof(*th);
878
879 /* Check if there is a timestamp option. */
880 if (tcp_opt_len == 0 ||
881 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
882 *ts_ptr != TCP_LRO_TS_OPTION)) {
883 /* We failed to find the timestamp option. */
884 le->timestamp = 0;
885 } else {
886 le->timestamp = 1;
887 le->tsval = ntohl(*(ts_ptr + 1));
888 le->tsecr = *(ts_ptr + 2);
889 }
890
891 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
892
893 /* Pull out TCP sequence numbers and window size. */
894 le->next_seq = ntohl(th->th_seq) + tcp_data_len;
895 le->ack_seq = th->th_ack;
896 le->window = th->th_win;
897 le->flags = tcp_get_flags(th);
898 le->needs_merge = 0;
899
900 /* Setup new data pointers. */
901 le->m_head = m;
902 le->m_tail = m_last(m);
903 }
904
905 static void
tcp_push_and_replace(struct lro_ctrl * lc,struct lro_entry * le,struct mbuf * m)906 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
907 {
908 struct lro_parser *pa;
909
910 /*
911 * Push up the stack of the current entry
912 * and replace it with "m".
913 */
914 struct mbuf *msave;
915
916 /* Grab off the next and save it */
917 msave = le->m_head->m_nextpkt;
918 le->m_head->m_nextpkt = NULL;
919
920 /* Now push out the old entry */
921 tcp_flush_out_entry(lc, le);
922
923 /* Re-parse new header, should not fail. */
924 pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
925 KASSERT(pa != NULL,
926 ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
927
928 /*
929 * Now to replace the data properly in the entry
930 * we have to reset the TCP header and
931 * other fields.
932 */
933 tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
934
935 /* Restore the next list */
936 m->m_nextpkt = msave;
937 }
938
939 static void
tcp_lro_mbuf_append_pkthdr(struct lro_entry * le,const struct mbuf * p)940 tcp_lro_mbuf_append_pkthdr(struct lro_entry *le, const struct mbuf *p)
941 {
942 struct mbuf *m;
943 uint32_t csum;
944
945 m = le->m_head;
946 if (m->m_pkthdr.lro_nsegs == 1) {
947 /* Compute relative checksum. */
948 csum = p->m_pkthdr.lro_tcp_d_csum;
949 } else {
950 /* Merge TCP data checksums. */
951 csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
952 (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
953 while (csum > 0xffff)
954 csum = (csum >> 16) + (csum & 0xffff);
955 }
956
957 /* Update various counters. */
958 m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
959 m->m_pkthdr.lro_tcp_d_csum = csum;
960 m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
961 m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
962 le->needs_merge = 1;
963 }
964
965 static void
tcp_lro_condense(struct lro_ctrl * lc,struct lro_entry * le)966 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
967 {
968 /*
969 * Walk through the mbuf chain we
970 * have on tap and compress/condense
971 * as required.
972 */
973 uint32_t *ts_ptr;
974 struct mbuf *m;
975 struct tcphdr *th;
976 uint32_t tcp_data_len_total;
977 uint32_t tcp_data_seg_total;
978 uint16_t tcp_data_len;
979 uint16_t tcp_opt_len;
980
981 /*
982 * First we must check the lead (m_head)
983 * we must make sure that it is *not*
984 * something that should be sent up
985 * right away (sack etc).
986 */
987 again:
988 m = le->m_head->m_nextpkt;
989 if (m == NULL) {
990 /* Just one left. */
991 return;
992 }
993
994 th = tcp_lro_get_th(m);
995 tcp_opt_len = (th->th_off << 2);
996 tcp_opt_len -= sizeof(*th);
997 ts_ptr = (uint32_t *)(th + 1);
998
999 if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1000 *ts_ptr != TCP_LRO_TS_OPTION)) {
1001 /*
1002 * Its not the timestamp. We can't
1003 * use this guy as the head.
1004 */
1005 le->m_head->m_nextpkt = m->m_nextpkt;
1006 tcp_push_and_replace(lc, le, m);
1007 goto again;
1008 }
1009 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1010 /*
1011 * Make sure that previously seen segments/ACKs are delivered
1012 * before this segment, e.g. FIN.
1013 */
1014 le->m_head->m_nextpkt = m->m_nextpkt;
1015 tcp_push_and_replace(lc, le, m);
1016 goto again;
1017 }
1018 while((m = le->m_head->m_nextpkt) != NULL) {
1019 /*
1020 * condense m into le, first
1021 * pull m out of the list.
1022 */
1023 le->m_head->m_nextpkt = m->m_nextpkt;
1024 m->m_nextpkt = NULL;
1025 /* Setup my data */
1026 tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1027 th = tcp_lro_get_th(m);
1028 ts_ptr = (uint32_t *)(th + 1);
1029 tcp_opt_len = (th->th_off << 2);
1030 tcp_opt_len -= sizeof(*th);
1031 tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1032 tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1033
1034 if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1035 tcp_data_len_total >= lc->lro_length_lim) {
1036 /* Flush now if appending will result in overflow. */
1037 tcp_push_and_replace(lc, le, m);
1038 goto again;
1039 }
1040 if (tcp_opt_len != 0 &&
1041 __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1042 *ts_ptr != TCP_LRO_TS_OPTION)) {
1043 /*
1044 * Maybe a sack in the new one? We need to
1045 * start all over after flushing the
1046 * current le. We will go up to the beginning
1047 * and flush it (calling the replace again possibly
1048 * or just returning).
1049 */
1050 tcp_push_and_replace(lc, le, m);
1051 goto again;
1052 }
1053 if ((tcp_get_flags(th) & ~(TH_ACK | TH_PUSH)) != 0) {
1054 tcp_push_and_replace(lc, le, m);
1055 goto again;
1056 }
1057 if (tcp_opt_len != 0) {
1058 uint32_t tsval = ntohl(*(ts_ptr + 1));
1059 /* Make sure timestamp values are increasing. */
1060 if (TSTMP_GT(le->tsval, tsval)) {
1061 tcp_push_and_replace(lc, le, m);
1062 goto again;
1063 }
1064 le->tsval = tsval;
1065 le->tsecr = *(ts_ptr + 2);
1066 }
1067 /* Try to append the new segment. */
1068 if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1069 ((tcp_get_flags(th) & TH_ACK) !=
1070 (le->flags & TH_ACK)) ||
1071 (tcp_data_len == 0 &&
1072 le->ack_seq == th->th_ack &&
1073 le->window == th->th_win))) {
1074 /* Out of order packet, non-ACK + ACK or dup ACK. */
1075 tcp_push_and_replace(lc, le, m);
1076 goto again;
1077 }
1078 if (tcp_data_len != 0 ||
1079 SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1080 le->next_seq += tcp_data_len;
1081 le->ack_seq = th->th_ack;
1082 le->window = th->th_win;
1083 le->needs_merge = 1;
1084 } else if (th->th_ack == le->ack_seq) {
1085 if (WIN_GT(th->th_win, le->window)) {
1086 le->window = th->th_win;
1087 le->needs_merge = 1;
1088 }
1089 }
1090
1091 if (tcp_data_len == 0) {
1092 m_freem(m);
1093 continue;
1094 }
1095
1096 /* Merge TCP data checksum and length to head mbuf. */
1097 tcp_lro_mbuf_append_pkthdr(le, m);
1098
1099 /*
1100 * Adjust the mbuf so that m_data points to the first byte of
1101 * the ULP payload. Adjust the mbuf to avoid complications and
1102 * append new segment to existing mbuf chain.
1103 */
1104 m_adj(m, m->m_pkthdr.len - tcp_data_len);
1105 m_demote_pkthdr(m);
1106 le->m_tail->m_next = m;
1107 le->m_tail = m_last(m);
1108 }
1109 }
1110
1111 void
tcp_lro_flush(struct lro_ctrl * lc,struct lro_entry * le)1112 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1113 {
1114
1115 /* Only optimise if there are multiple packets waiting. */
1116 NET_EPOCH_ASSERT();
1117 if (tcp_lro_flush_tcphpts == NULL ||
1118 tcp_lro_flush_tcphpts(lc, le) != 0) {
1119 tcp_lro_condense(lc, le);
1120 tcp_flush_out_entry(lc, le);
1121 }
1122 lc->lro_flushed++;
1123 bzero(le, sizeof(*le));
1124 LIST_INSERT_HEAD(&lc->lro_free, le, next);
1125 }
1126
1127 #define tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1128
1129 /*
1130 * The tcp_lro_sort() routine is comparable to qsort(), except it has
1131 * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1132 * number of elements to sort and 64 is the number of sequence bits
1133 * available. The algorithm is bit-slicing the 64-bit sequence number,
1134 * sorting one bit at a time from the most significant bit until the
1135 * least significant one, skipping the constant bits. This is
1136 * typically called a radix sort.
1137 */
1138 static void
tcp_lro_sort(struct lro_mbuf_sort * parray,uint32_t size)1139 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1140 {
1141 struct lro_mbuf_sort temp;
1142 uint64_t ones;
1143 uint64_t zeros;
1144 uint32_t x;
1145 uint32_t y;
1146
1147 repeat:
1148 /* for small arrays insertion sort is faster */
1149 if (size <= 12) {
1150 for (x = 1; x < size; x++) {
1151 temp = parray[x];
1152 for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1153 parray[y] = parray[y - 1];
1154 parray[y] = temp;
1155 }
1156 return;
1157 }
1158
1159 /* compute sequence bits which are constant */
1160 ones = 0;
1161 zeros = 0;
1162 for (x = 0; x != size; x++) {
1163 ones |= parray[x].seq;
1164 zeros |= ~parray[x].seq;
1165 }
1166
1167 /* compute bits which are not constant into "ones" */
1168 ones &= zeros;
1169 if (ones == 0)
1170 return;
1171
1172 /* pick the most significant bit which is not constant */
1173 ones = tcp_lro_msb_64(ones);
1174
1175 /*
1176 * Move entries having cleared sequence bits to the beginning
1177 * of the array:
1178 */
1179 for (x = y = 0; y != size; y++) {
1180 /* skip set bits */
1181 if (parray[y].seq & ones)
1182 continue;
1183 /* swap entries */
1184 temp = parray[x];
1185 parray[x] = parray[y];
1186 parray[y] = temp;
1187 x++;
1188 }
1189
1190 KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1191
1192 /* sort zeros */
1193 tcp_lro_sort(parray, x);
1194
1195 /* sort ones */
1196 parray += x;
1197 size -= x;
1198 goto repeat;
1199 }
1200
1201 void
tcp_lro_flush_all(struct lro_ctrl * lc)1202 tcp_lro_flush_all(struct lro_ctrl *lc)
1203 {
1204 uint64_t seq;
1205 uint64_t nseq;
1206 unsigned x;
1207
1208 NET_EPOCH_ASSERT();
1209 /* check if no mbufs to flush */
1210 if (lc->lro_mbuf_count == 0)
1211 goto done;
1212 if (lc->lro_cpu_is_set == 0) {
1213 if (lc->lro_last_cpu == curcpu) {
1214 lc->lro_cnt_of_same_cpu++;
1215 /* Have we reached the threshold to declare a cpu? */
1216 if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1217 lc->lro_cpu_is_set = 1;
1218 } else {
1219 lc->lro_last_cpu = curcpu;
1220 lc->lro_cnt_of_same_cpu = 0;
1221 }
1222 }
1223 CURVNET_SET(lc->ifp->if_vnet);
1224
1225 /* get current time */
1226 binuptime(&lc->lro_last_queue_time);
1227
1228 /* sort all mbufs according to stream */
1229 tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1230
1231 /* input data into LRO engine, stream by stream */
1232 seq = 0;
1233 for (x = 0; x != lc->lro_mbuf_count; x++) {
1234 struct mbuf *mb;
1235
1236 /* get mbuf */
1237 mb = lc->lro_mbuf_data[x].mb;
1238
1239 /* get sequence number, masking away the packet index */
1240 nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1241
1242 /* check for new stream */
1243 if (seq != nseq) {
1244 seq = nseq;
1245
1246 /* flush active streams */
1247 tcp_lro_rx_done(lc);
1248 }
1249
1250 /* add packet to LRO engine */
1251 if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1252 /* Flush anything we have acummulated */
1253 tcp_lro_flush_active(lc);
1254 /* input packet to network layer */
1255 (*lc->ifp->if_input)(lc->ifp, mb);
1256 lc->lro_queued++;
1257 lc->lro_flushed++;
1258 }
1259 }
1260 CURVNET_RESTORE();
1261 done:
1262 /* flush active streams */
1263 tcp_lro_rx_done(lc);
1264 tcp_hpts_softclock();
1265 lc->lro_mbuf_count = 0;
1266 }
1267
1268 static struct lro_head *
tcp_lro_rx_get_bucket(struct lro_ctrl * lc,struct mbuf * m,struct lro_parser * parser)1269 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1270 {
1271 u_long hash;
1272
1273 if (M_HASHTYPE_ISHASH(m)) {
1274 hash = m->m_pkthdr.flowid;
1275 } else {
1276 for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1277 hash += parser->data.raw[i];
1278 }
1279 return (&lc->lro_hash[hash % lc->lro_hashsz]);
1280 }
1281
1282 static int
tcp_lro_rx_common(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum,bool use_hash)1283 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1284 {
1285 struct lro_parser pi; /* inner address data */
1286 struct lro_parser po; /* outer address data */
1287 struct lro_parser *pa; /* current parser for TCP stream */
1288 struct lro_entry *le;
1289 struct lro_head *bucket;
1290 struct tcphdr *th;
1291 int tcp_data_len;
1292 int tcp_opt_len;
1293 int error;
1294 uint16_t tcp_data_sum;
1295
1296 #ifdef INET
1297 /* Quickly decide if packet cannot be LRO'ed */
1298 if (__predict_false(V_ipforwarding != 0))
1299 return (TCP_LRO_CANNOT);
1300 #endif
1301 #ifdef INET6
1302 /* Quickly decide if packet cannot be LRO'ed */
1303 if (__predict_false(V_ip6_forwarding != 0))
1304 return (TCP_LRO_CANNOT);
1305 #endif
1306 if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1307 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1308 (m->m_pkthdr.csum_data != 0xffff)) {
1309 /*
1310 * The checksum either did not have hardware offload
1311 * or it was a bad checksum. We can't LRO such
1312 * a packet.
1313 */
1314 counter_u64_add(tcp_bad_csums, 1);
1315 return (TCP_LRO_CANNOT);
1316 }
1317 /* We expect a contiguous header [eh, ip, tcp]. */
1318 pa = tcp_lro_parser(m, &po, &pi, true);
1319 if (__predict_false(pa == NULL))
1320 return (TCP_LRO_NOT_SUPPORTED);
1321
1322 /* We don't expect any padding. */
1323 error = tcp_lro_trim_mbuf_chain(m, pa);
1324 if (__predict_false(error != 0))
1325 return (error);
1326
1327 #ifdef INET
1328 switch (pa->data.lro_type) {
1329 case LRO_TYPE_IPV4_TCP:
1330 error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1331 if (__predict_false(error != 0))
1332 return (error);
1333 break;
1334 default:
1335 break;
1336 }
1337 #endif
1338 /* If no hardware or arrival stamp on the packet add timestamp */
1339 if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1340 m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1341 m->m_flags |= M_TSTMP_LRO;
1342 }
1343
1344 /* Get pointer to TCP header. */
1345 th = pa->tcp;
1346
1347 /* Don't process SYN packets. */
1348 if (__predict_false(tcp_get_flags(th) & TH_SYN))
1349 return (TCP_LRO_CANNOT);
1350
1351 /* Get total TCP header length and compute payload length. */
1352 tcp_opt_len = (th->th_off << 2);
1353 tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1354 (uint8_t *)m->m_data) - tcp_opt_len;
1355 tcp_opt_len -= sizeof(*th);
1356
1357 /* Don't process invalid TCP headers. */
1358 if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1359 return (TCP_LRO_CANNOT);
1360
1361 /* Compute TCP data only checksum. */
1362 if (tcp_data_len == 0)
1363 tcp_data_sum = 0; /* no data, no checksum */
1364 else if (__predict_false(csum != 0))
1365 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1366 else
1367 tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1368
1369 /* Save TCP info in mbuf. */
1370 m->m_nextpkt = NULL;
1371 m->m_pkthdr.rcvif = lc->ifp;
1372 m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1373 m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1374 m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1375 m->m_pkthdr.lro_nsegs = 1;
1376
1377 /* Get hash bucket. */
1378 if (!use_hash) {
1379 bucket = &lc->lro_hash[0];
1380 } else {
1381 bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1382 }
1383
1384 /* Try to find a matching previous segment. */
1385 LIST_FOREACH(le, bucket, hash_next) {
1386 /* Compare addresses and ports. */
1387 if (lro_address_compare(&po.data, &le->outer.data) == false ||
1388 lro_address_compare(&pi.data, &le->inner.data) == false)
1389 continue;
1390
1391 /* Check if no data and old ACK. */
1392 if (tcp_data_len == 0 &&
1393 SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1394 m_freem(m);
1395 return (0);
1396 }
1397
1398 /* Mark "m" in the last spot. */
1399 le->m_last_mbuf->m_nextpkt = m;
1400 /* Now set the tail to "m". */
1401 le->m_last_mbuf = m;
1402 return (0);
1403 }
1404
1405 /* Try to find an empty slot. */
1406 if (LIST_EMPTY(&lc->lro_free))
1407 return (TCP_LRO_NO_ENTRIES);
1408
1409 /* Start a new segment chain. */
1410 le = LIST_FIRST(&lc->lro_free);
1411 LIST_REMOVE(le, next);
1412 tcp_lro_active_insert(lc, bucket, le);
1413
1414 /* Make sure the headers are set. */
1415 le->inner = pi;
1416 le->outer = po;
1417
1418 /* Store time this entry was allocated. */
1419 le->alloc_time = lc->lro_last_queue_time;
1420
1421 tcp_set_entry_to_mbuf(lc, le, m, th);
1422
1423 /* Now set the tail to "m". */
1424 le->m_last_mbuf = m;
1425
1426 return (0);
1427 }
1428
1429 int
tcp_lro_rx(struct lro_ctrl * lc,struct mbuf * m,uint32_t csum)1430 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1431 {
1432 int error;
1433
1434 if (((m->m_pkthdr.csum_flags & (CSUM_DATA_VALID | CSUM_PSEUDO_HDR)) !=
1435 ((CSUM_DATA_VALID | CSUM_PSEUDO_HDR))) ||
1436 (m->m_pkthdr.csum_data != 0xffff)) {
1437 /*
1438 * The checksum either did not have hardware offload
1439 * or it was a bad checksum. We can't LRO such
1440 * a packet.
1441 */
1442 counter_u64_add(tcp_bad_csums, 1);
1443 return (TCP_LRO_CANNOT);
1444 }
1445 /* get current time */
1446 binuptime(&lc->lro_last_queue_time);
1447 CURVNET_SET(lc->ifp->if_vnet);
1448 error = tcp_lro_rx_common(lc, m, csum, true);
1449 if (__predict_false(error != 0)) {
1450 /*
1451 * Flush anything we have acummulated
1452 * ahead of this packet that can't
1453 * be LRO'd. This preserves order.
1454 */
1455 tcp_lro_flush_active(lc);
1456 }
1457 CURVNET_RESTORE();
1458
1459 return (error);
1460 }
1461
1462 void
tcp_lro_queue_mbuf(struct lro_ctrl * lc,struct mbuf * mb)1463 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
1464 {
1465 NET_EPOCH_ASSERT();
1466 /* sanity checks */
1467 if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
1468 lc->lro_mbuf_max == 0)) {
1469 /* packet drop */
1470 m_freem(mb);
1471 return;
1472 }
1473
1474 /* check if packet is not LRO capable */
1475 if (__predict_false((lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
1476 /* input packet to network layer */
1477 (*lc->ifp->if_input) (lc->ifp, mb);
1478 return;
1479 }
1480
1481 /* If no hardware or arrival stamp on the packet add timestamp */
1482 if ((tcplro_stacks_wanting_mbufq > 0) &&
1483 (tcp_less_accurate_lro_ts == 0) &&
1484 ((mb->m_flags & M_TSTMP) == 0)) {
1485 /* Add in an LRO time since no hardware */
1486 binuptime(&lc->lro_last_queue_time);
1487 mb->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1488 mb->m_flags |= M_TSTMP_LRO;
1489 }
1490
1491 /* create sequence number */
1492 lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
1493 (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
1494 (((uint64_t)mb->m_pkthdr.flowid) << 24) |
1495 ((uint64_t)lc->lro_mbuf_count);
1496
1497 /* enter mbuf */
1498 lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
1499
1500 /* flush if array is full */
1501 if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
1502 tcp_lro_flush_all(lc);
1503 }
1504
1505 /* end */
1506