2 * Copyright (c) 2007, Myricom Inc.
3 * Copyright (c) 2008, Intel Corporation.
4 * Copyright (c) 2012 The FreeBSD Foundation
7 * Portions of this software were developed by Bjoern Zeeb
8 * under sponsorship from the FreeBSD Foundation.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
36 #include "opt_inet6.h"
38 #include <sys/param.h>
39 #include <sys/systm.h>
41 #include <sys/kernel.h>
42 #include <sys/socket.h>
45 #include <net/if_var.h>
46 #include <net/ethernet.h>
49 #include <netinet/in_systm.h>
50 #include <netinet/in.h>
51 #include <netinet/ip6.h>
52 #include <netinet/ip.h>
53 #include <netinet/ip_var.h>
54 #include <netinet/tcp.h>
55 #include <netinet/tcp_lro.h>
57 #include <netinet6/ip6_var.h>
59 #include <machine/in_cksum.h>
62 #define LRO_ENTRIES 8 /* # of LRO entries per RX queue. */
65 #define TCP_LRO_UPDATE_CSUM 1
66 #ifndef TCP_LRO_UPDATE_CSUM
67 #define TCP_LRO_INVALID_CSUM 0x0000
71 tcp_lro_init(struct lro_ctrl *lc)
80 SLIST_INIT(&lc->lro_free);
81 SLIST_INIT(&lc->lro_active);
84 for (i = 0; i < LRO_ENTRIES; i++) {
85 le = (struct lro_entry *)malloc(sizeof(*le), M_DEVBUF,
93 SLIST_INSERT_HEAD(&lc->lro_free, le, next);
100 tcp_lro_free(struct lro_ctrl *lc)
102 struct lro_entry *le;
104 while (!SLIST_EMPTY(&lc->lro_free)) {
105 le = SLIST_FIRST(&lc->lro_free);
106 SLIST_REMOVE_HEAD(&lc->lro_free, next);
111 #ifdef TCP_LRO_UPDATE_CSUM
113 tcp_lro_csum_th(struct tcphdr *th)
118 ch = th->th_sum = 0x0000;
129 ch = (ch >> 16) + (ch & 0xffff);
131 return (ch & 0xffff);
135 tcp_lro_rx_csum_fixup(struct lro_entry *le, void *l3hdr, struct tcphdr *th,
136 uint16_t tcp_data_len, uint16_t csum)
143 /* Remove length from checksum. */
144 switch (le->eh_type) {
150 ip6 = (struct ip6_hdr *)l3hdr;
151 if (le->append_cnt == 0)
156 cx = ntohs(ip6->ip6_plen);
157 cs = in6_cksum_pseudo(ip6, cx, ip6->ip6_nxt, 0);
167 ip4 = (struct ip *)l3hdr;
168 if (le->append_cnt == 0)
171 cs = in_addword(ntohs(ip4->ip_len) - sizeof(*ip4),
173 cs = in_pseudo(ip4->ip_src.s_addr, ip4->ip_dst.s_addr,
180 cs = 0; /* Keep compiler happy. */
186 /* Remove TCP header csum. */
187 cs = ~tcp_lro_csum_th(th);
190 c = (c >> 16) + (c & 0xffff);
197 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
200 if (le->append_cnt > 0) {
204 p_len = htons(le->p_len);
205 switch (le->eh_type) {
212 ip6->ip6_plen = p_len;
213 th = (struct tcphdr *)(ip6 + 1);
214 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
216 le->p_len += ETHER_HDR_LEN + sizeof(*ip6);
224 #ifdef TCP_LRO_UPDATE_CSUM
230 #ifdef TCP_LRO_UPDATE_CSUM
231 /* Fix IP header checksum for new length. */
237 cl = (cl >> 16) + (cl & 0xffff);
241 ip4->ip_sum = TCP_LRO_INVALID_CSUM;
244 th = (struct tcphdr *)(ip4 + 1);
245 le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
246 CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
247 le->p_len += ETHER_HDR_LEN;
252 th = NULL; /* Keep compiler happy. */
254 le->m_head->m_pkthdr.csum_data = 0xffff;
255 le->m_head->m_pkthdr.len = le->p_len;
257 /* Incorporate the latest ACK into the TCP header. */
258 th->th_ack = le->ack_seq;
259 th->th_win = le->window;
260 /* Incorporate latest timestamp into the TCP header. */
261 if (le->timestamp != 0) {
264 ts_ptr = (uint32_t *)(th + 1);
265 ts_ptr[1] = htonl(le->tsval);
266 ts_ptr[2] = le->tsecr;
268 #ifdef TCP_LRO_UPDATE_CSUM
269 /* Update the TCP header checksum. */
270 le->ulp_csum += p_len;
271 le->ulp_csum += tcp_lro_csum_th(th);
272 while (le->ulp_csum > 0xffff)
273 le->ulp_csum = (le->ulp_csum >> 16) +
274 (le->ulp_csum & 0xffff);
275 th->th_sum = (le->ulp_csum & 0xffff);
276 th->th_sum = ~th->th_sum;
278 th->th_sum = TCP_LRO_INVALID_CSUM;
282 (*lc->ifp->if_input)(lc->ifp, le->m_head);
283 lc->lro_queued += le->append_cnt + 1;
285 bzero(le, sizeof(*le));
286 SLIST_INSERT_HEAD(&lc->lro_free, le, next);
291 tcp_lro_rx_ipv6(struct lro_ctrl *lc, struct mbuf *m, struct ip6_hdr *ip6,
295 /* XXX-BZ we should check the flow-label. */
297 /* XXX-BZ We do not yet support ext. hdrs. */
298 if (ip6->ip6_nxt != IPPROTO_TCP)
299 return (TCP_LRO_NOT_SUPPORTED);
301 /* Find the TCP header. */
302 *th = (struct tcphdr *)(ip6 + 1);
310 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4,
316 if (ip4->ip_p != IPPROTO_TCP)
317 return (TCP_LRO_NOT_SUPPORTED);
319 /* Ensure there are no options. */
320 if ((ip4->ip_hl << 2) != sizeof (*ip4))
321 return (TCP_LRO_CANNOT);
323 /* .. and the packet is not fragmented. */
324 if (ip4->ip_off & htons(IP_MF|IP_OFFMASK))
325 return (TCP_LRO_CANNOT);
327 /* Legacy IP has a header checksum that needs to be correct. */
328 csum_flags = m->m_pkthdr.csum_flags;
329 if (csum_flags & CSUM_IP_CHECKED) {
330 if (__predict_false((csum_flags & CSUM_IP_VALID) == 0)) {
332 return (TCP_LRO_CANNOT);
335 csum = in_cksum_hdr(ip4);
336 if (__predict_false((csum ^ 0xffff) != 0)) {
338 return (TCP_LRO_CANNOT);
342 /* Find the TCP header (we assured there are no IP options). */
343 *th = (struct tcphdr *)(ip4 + 1);
350 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
352 struct lro_entry *le;
353 struct ether_header *eh;
355 struct ip6_hdr *ip6 = NULL; /* Keep compiler happy. */
358 struct ip *ip4 = NULL; /* Keep compiler happy. */
361 void *l3hdr = NULL; /* Keep compiler happy. */
364 int error, ip_len, l;
365 uint16_t eh_type, tcp_data_len;
367 /* We expect a contiguous header [eh, ip, tcp]. */
369 eh = mtod(m, struct ether_header *);
370 eh_type = ntohs(eh->ether_type);
375 CURVNET_SET(lc->ifp->if_vnet);
376 if (V_ip6_forwarding != 0) {
377 /* XXX-BZ stats but changing lro_ctrl is a problem. */
379 return (TCP_LRO_CANNOT);
382 l3hdr = ip6 = (struct ip6_hdr *)(eh + 1);
383 error = tcp_lro_rx_ipv6(lc, m, ip6, &th);
386 tcp_data_len = ntohs(ip6->ip6_plen);
387 ip_len = sizeof(*ip6) + tcp_data_len;
394 CURVNET_SET(lc->ifp->if_vnet);
395 if (V_ipforwarding != 0) {
396 /* XXX-BZ stats but changing lro_ctrl is a problem. */
398 return (TCP_LRO_CANNOT);
401 l3hdr = ip4 = (struct ip *)(eh + 1);
402 error = tcp_lro_rx_ipv4(lc, m, ip4, &th);
405 ip_len = ntohs(ip4->ip_len);
406 tcp_data_len = ip_len - sizeof(*ip4);
410 /* XXX-BZ what happens in case of VLAN(s)? */
412 return (TCP_LRO_NOT_SUPPORTED);
416 * If the frame is padded beyond the end of the IP packet, then we must
417 * trim the extra bytes off.
419 l = m->m_pkthdr.len - (ETHER_HDR_LEN + ip_len);
422 /* Truncated packet. */
423 return (TCP_LRO_CANNOT);
429 * Check TCP header constraints.
431 /* Ensure no bits set besides ACK or PSH. */
432 if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0)
433 return (TCP_LRO_CANNOT);
435 /* XXX-BZ We lose a AKC|PUSH flag concatinating multiple segments. */
436 /* XXX-BZ Ideally we'd flush on PUSH? */
439 * Check for timestamps.
440 * Since the only option we handle are timestamps, we only have to
441 * handle the simple case of aligned timestamps.
443 l = (th->th_off << 2);
446 ts_ptr = (uint32_t *)(th + 1);
447 if (l != 0 && (__predict_false(l != TCPOLEN_TSTAMP_APPA) ||
448 (*ts_ptr != ntohl(TCPOPT_NOP<<24|TCPOPT_NOP<<16|
449 TCPOPT_TIMESTAMP<<8|TCPOLEN_TIMESTAMP))))
450 return (TCP_LRO_CANNOT);
452 /* If the driver did not pass in the checksum, set it now. */
456 seq = ntohl(th->th_seq);
458 /* Try to find a matching previous segment. */
459 SLIST_FOREACH(le, &lc->lro_active, next) {
460 if (le->eh_type != eh_type)
462 if (le->source_port != th->th_sport ||
463 le->dest_port != th->th_dport)
468 if (bcmp(&le->source_ip6, &ip6->ip6_src,
469 sizeof(struct in6_addr)) != 0 ||
470 bcmp(&le->dest_ip6, &ip6->ip6_dst,
471 sizeof(struct in6_addr)) != 0)
477 if (le->source_ip4 != ip4->ip_src.s_addr ||
478 le->dest_ip4 != ip4->ip_dst.s_addr)
484 /* Flush now if appending will result in overflow. */
485 if (le->p_len > (65535 - tcp_data_len)) {
486 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next);
487 tcp_lro_flush(lc, le);
491 /* Try to append the new segment. */
492 if (__predict_false(seq != le->next_seq ||
493 (tcp_data_len == 0 && le->ack_seq == th->th_ack))) {
494 /* Out of order packet or duplicate ACK. */
495 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next);
496 tcp_lro_flush(lc, le);
497 return (TCP_LRO_CANNOT);
501 uint32_t tsval = ntohl(*(ts_ptr + 1));
502 /* Make sure timestamp values are increasing. */
503 /* XXX-BZ flip and use TSTMP_GEQ macro for this? */
504 if (__predict_false(le->tsval > tsval ||
506 return (TCP_LRO_CANNOT);
508 le->tsecr = *(ts_ptr + 2);
511 le->next_seq += tcp_data_len;
512 le->ack_seq = th->th_ack;
513 le->window = th->th_win;
516 #ifdef TCP_LRO_UPDATE_CSUM
517 le->ulp_csum += tcp_lro_rx_csum_fixup(le, l3hdr, th,
518 tcp_data_len, ~csum);
521 if (tcp_data_len == 0) {
526 le->p_len += tcp_data_len;
529 * Adjust the mbuf so that m_data points to the first byte of
530 * the ULP payload. Adjust the mbuf to avoid complications and
531 * append new segment to existing mbuf chain.
533 m_adj(m, m->m_pkthdr.len - tcp_data_len);
534 m->m_flags &= ~M_PKTHDR;
536 le->m_tail->m_next = m;
537 le->m_tail = m_last(m);
540 * If a possible next full length packet would cause an
541 * overflow, pro-actively flush now.
543 if (le->p_len > (65535 - lc->ifp->if_mtu)) {
544 SLIST_REMOVE(&lc->lro_active, le, lro_entry, next);
545 tcp_lro_flush(lc, le);
551 /* Try to find an empty slot. */
552 if (SLIST_EMPTY(&lc->lro_free))
553 return (TCP_LRO_CANNOT);
555 /* Start a new segment chain. */
556 le = SLIST_FIRST(&lc->lro_free);
557 SLIST_REMOVE_HEAD(&lc->lro_free, next);
558 SLIST_INSERT_HEAD(&lc->lro_active, le, next);
560 /* Start filling in details. */
565 le->source_ip6 = ip6->ip6_src;
566 le->dest_ip6 = ip6->ip6_dst;
567 le->eh_type = eh_type;
568 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN - sizeof(*ip6);
574 le->source_ip4 = ip4->ip_src.s_addr;
575 le->dest_ip4 = ip4->ip_dst.s_addr;
576 le->eh_type = eh_type;
577 le->p_len = m->m_pkthdr.len - ETHER_HDR_LEN;
581 le->source_port = th->th_sport;
582 le->dest_port = th->th_dport;
584 le->next_seq = seq + tcp_data_len;
585 le->ack_seq = th->th_ack;
586 le->window = th->th_win;
589 le->tsval = ntohl(*(ts_ptr + 1));
590 le->tsecr = *(ts_ptr + 2);
593 #ifdef TCP_LRO_UPDATE_CSUM
595 * Do not touch the csum of the first packet. However save the
596 * "adjusted" checksum of just the source and destination addresses,
597 * the next header and the TCP payload. The length and TCP header
598 * parts may change, so we remove those from the saved checksum and
599 * re-add with final values on tcp_lro_flush() if needed.
601 KASSERT(le->ulp_csum == 0, ("%s: le=%p le->ulp_csum=0x%04x\n",
602 __func__, le, le->ulp_csum));
604 le->ulp_csum = tcp_lro_rx_csum_fixup(le, l3hdr, th, tcp_data_len,
606 th->th_sum = csum; /* Restore checksum on first packet. */
610 le->m_tail = m_last(m);