xref: /freebsd/sys/netinet/tcp_lro.c (revision 9c1c02093b90ae49745a174eb26ea85dd1990eec)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 __FBSDID("$FreeBSD$");
37 
38 #include "opt_inet.h"
39 #include "opt_inet6.h"
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/malloc.h>
45 #include <sys/mbuf.h>
46 #include <sys/socket.h>
47 #include <sys/socketvar.h>
48 #include <sys/sockbuf.h>
49 #include <sys/sysctl.h>
50 
51 #include <net/if.h>
52 #include <net/if_var.h>
53 #include <net/ethernet.h>
54 #include <net/bpf.h>
55 #include <net/vnet.h>
56 
57 #include <netinet/in_systm.h>
58 #include <netinet/in.h>
59 #include <netinet/ip6.h>
60 #include <netinet/ip.h>
61 #include <netinet/ip_var.h>
62 #include <netinet/in_pcb.h>
63 #include <netinet6/in6_pcb.h>
64 #include <netinet/tcp.h>
65 #include <netinet/tcp_seq.h>
66 #include <netinet/tcp_lro.h>
67 #include <netinet/tcp_var.h>
68 #include <netinet/tcpip.h>
69 #include <netinet/tcp_hpts.h>
70 #include <netinet/tcp_log_buf.h>
71 #include <netinet/udp.h>
72 #include <netinet6/ip6_var.h>
73 
74 #include <machine/in_cksum.h>
75 
76 static MALLOC_DEFINE(M_LRO, "LRO", "LRO control structures");
77 
78 #define	TCP_LRO_TS_OPTION \
79     ntohl((TCPOPT_NOP << 24) | (TCPOPT_NOP << 16) | \
80 	  (TCPOPT_TIMESTAMP << 8) | TCPOLEN_TIMESTAMP)
81 
82 static void	tcp_lro_rx_done(struct lro_ctrl *lc);
83 static int	tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m,
84 		    uint32_t csum, bool use_hash);
85 
86 #ifdef TCPHPTS
87 static bool	do_bpf_strip_and_compress(struct inpcb *, struct lro_ctrl *,
88 		struct lro_entry *, struct mbuf **, struct mbuf **, struct mbuf **, bool *, bool);
89 
90 #endif
91 
92 SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
93     "TCP LRO");
94 
95 static long tcplro_stacks_wanting_mbufq;
96 counter_u64_t tcp_inp_lro_direct_queue;
97 counter_u64_t tcp_inp_lro_wokeup_queue;
98 counter_u64_t tcp_inp_lro_compressed;
99 counter_u64_t tcp_inp_lro_locks_taken;
100 counter_u64_t tcp_extra_mbuf;
101 counter_u64_t tcp_would_have_but;
102 counter_u64_t tcp_comp_total;
103 counter_u64_t tcp_uncomp_total;
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 interrups in a row on the same CPU that will make us declare an 'affinity' cpu?");
114 
115 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, fullqueue, CTLFLAG_RD,
116     &tcp_inp_lro_direct_queue, "Number of lro's fully queued to transport");
117 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, wokeup, CTLFLAG_RD,
118     &tcp_inp_lro_wokeup_queue, "Number of lro's where we woke up transport via hpts");
119 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, compressed, CTLFLAG_RD,
120     &tcp_inp_lro_compressed, "Number of lro's compressed and sent to transport");
121 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, lockcnt, CTLFLAG_RD,
122     &tcp_inp_lro_locks_taken, "Number of lro's inp_wlocks taken");
123 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, extra_mbuf, CTLFLAG_RD,
124     &tcp_extra_mbuf, "Number of times we had an extra compressed ack dropped into the tp");
125 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, would_have_but, CTLFLAG_RD,
126     &tcp_would_have_but, "Number of times we would have had an extra compressed, but mget failed");
127 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, with_m_ackcmp, CTLFLAG_RD,
128     &tcp_comp_total, "Number of mbufs queued with M_ACKCMP flags set");
129 SYSCTL_COUNTER_U64(_net_inet_tcp_lro, OID_AUTO, without_m_ackcmp, CTLFLAG_RD,
130     &tcp_uncomp_total, "Number of mbufs queued without M_ACKCMP");
131 
132 void
133 tcp_lro_reg_mbufq(void)
134 {
135 	atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, 1);
136 }
137 
138 void
139 tcp_lro_dereg_mbufq(void)
140 {
141 	atomic_fetchadd_long(&tcplro_stacks_wanting_mbufq, -1);
142 }
143 
144 static __inline void
145 tcp_lro_active_insert(struct lro_ctrl *lc, struct lro_head *bucket,
146     struct lro_entry *le)
147 {
148 
149 	LIST_INSERT_HEAD(&lc->lro_active, le, next);
150 	LIST_INSERT_HEAD(bucket, le, hash_next);
151 }
152 
153 static __inline void
154 tcp_lro_active_remove(struct lro_entry *le)
155 {
156 
157 	LIST_REMOVE(le, next);		/* active list */
158 	LIST_REMOVE(le, hash_next);	/* hash bucket */
159 }
160 
161 int
162 tcp_lro_init(struct lro_ctrl *lc)
163 {
164 	return (tcp_lro_init_args(lc, NULL, tcp_lro_entries, 0));
165 }
166 
167 int
168 tcp_lro_init_args(struct lro_ctrl *lc, struct ifnet *ifp,
169     unsigned lro_entries, unsigned lro_mbufs)
170 {
171 	struct lro_entry *le;
172 	size_t size;
173 	unsigned i, elements;
174 
175 	lc->lro_bad_csum = 0;
176 	lc->lro_queued = 0;
177 	lc->lro_flushed = 0;
178 	lc->lro_mbuf_count = 0;
179 	lc->lro_mbuf_max = lro_mbufs;
180 	lc->lro_cnt = lro_entries;
181 	lc->lro_ackcnt_lim = TCP_LRO_ACKCNT_MAX;
182 	lc->lro_length_lim = TCP_LRO_LENGTH_MAX;
183 	lc->ifp = ifp;
184 	LIST_INIT(&lc->lro_free);
185 	LIST_INIT(&lc->lro_active);
186 
187 	/* create hash table to accelerate entry lookup */
188 	if (lro_entries > lro_mbufs)
189 		elements = lro_entries;
190 	else
191 		elements = lro_mbufs;
192 	lc->lro_hash = phashinit_flags(elements, M_LRO, &lc->lro_hashsz,
193 	    HASH_NOWAIT);
194 	if (lc->lro_hash == NULL) {
195 		memset(lc, 0, sizeof(*lc));
196 		return (ENOMEM);
197 	}
198 
199 	/* compute size to allocate */
200 	size = (lro_mbufs * sizeof(struct lro_mbuf_sort)) +
201 	    (lro_entries * sizeof(*le));
202 	lc->lro_mbuf_data = (struct lro_mbuf_sort *)
203 	    malloc(size, M_LRO, M_NOWAIT | M_ZERO);
204 
205 	/* check for out of memory */
206 	if (lc->lro_mbuf_data == NULL) {
207 		free(lc->lro_hash, M_LRO);
208 		memset(lc, 0, sizeof(*lc));
209 		return (ENOMEM);
210 	}
211 	/* compute offset for LRO entries */
212 	le = (struct lro_entry *)
213 	    (lc->lro_mbuf_data + lro_mbufs);
214 
215 	/* setup linked list */
216 	for (i = 0; i != lro_entries; i++)
217 		LIST_INSERT_HEAD(&lc->lro_free, le + i, next);
218 
219 	return (0);
220 }
221 
222 struct vxlan_header {
223 	uint32_t	vxlh_flags;
224 	uint32_t	vxlh_vni;
225 };
226 
227 static inline void *
228 tcp_lro_low_level_parser(void *ptr, struct lro_parser *parser, bool update_data, bool is_vxlan)
229 {
230 	const struct ether_vlan_header *eh;
231 	void *old;
232 	uint16_t eth_type;
233 
234 	if (update_data)
235 		memset(parser, 0, sizeof(*parser));
236 
237 	old = ptr;
238 
239 	if (is_vxlan) {
240 		const struct vxlan_header *vxh;
241 		vxh = ptr;
242 		ptr = (uint8_t *)ptr + sizeof(*vxh);
243 		if (update_data) {
244 			parser->data.vxlan_vni =
245 			    vxh->vxlh_vni & htonl(0xffffff00);
246 		}
247 	}
248 
249 	eh = ptr;
250 	if (__predict_false(eh->evl_encap_proto == htons(ETHERTYPE_VLAN))) {
251 		eth_type = eh->evl_proto;
252 		if (update_data) {
253 			/* strip priority and keep VLAN ID only */
254 			parser->data.vlan_id = eh->evl_tag & htons(EVL_VLID_MASK);
255 		}
256 		/* advance to next header */
257 		ptr = (uint8_t *)ptr + ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN;
258 	} else {
259 		eth_type = eh->evl_encap_proto;
260 		/* advance to next header */
261 		ptr = (uint8_t *)ptr + ETHER_HDR_LEN;
262 	}
263 
264 	switch (eth_type) {
265 #ifdef INET
266 	case htons(ETHERTYPE_IP):
267 		parser->ip4 = ptr;
268 		/* Ensure there are no IPv4 options. */
269 		if ((parser->ip4->ip_hl << 2) != sizeof (*parser->ip4))
270 			break;
271 		/* .. and the packet is not fragmented. */
272 		if (parser->ip4->ip_off & htons(IP_MF|IP_OFFMASK))
273 			break;
274 		ptr = (uint8_t *)ptr + (parser->ip4->ip_hl << 2);
275 		if (update_data) {
276 			parser->data.s_addr.v4 = parser->ip4->ip_src;
277 			parser->data.d_addr.v4 = parser->ip4->ip_dst;
278 		}
279 		switch (parser->ip4->ip_p) {
280 		case IPPROTO_UDP:
281 			parser->udp = ptr;
282 			if (update_data) {
283 				parser->data.lro_type = LRO_TYPE_IPV4_UDP;
284 				parser->data.s_port = parser->udp->uh_sport;
285 				parser->data.d_port = parser->udp->uh_dport;
286 			} else {
287 				MPASS(parser->data.lro_type == LRO_TYPE_IPV4_UDP);
288 			}
289 			ptr = ((uint8_t *)ptr + sizeof(*parser->udp));
290 			parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
291 			return (ptr);
292 		case IPPROTO_TCP:
293 			parser->tcp = ptr;
294 			if (update_data) {
295 				parser->data.lro_type = LRO_TYPE_IPV4_TCP;
296 				parser->data.s_port = parser->tcp->th_sport;
297 				parser->data.d_port = parser->tcp->th_dport;
298 			} else {
299 				MPASS(parser->data.lro_type == LRO_TYPE_IPV4_TCP);
300 			}
301 			ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
302 			parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
303 			return (ptr);
304 		default:
305 			break;
306 		}
307 		break;
308 #endif
309 #ifdef INET6
310 	case htons(ETHERTYPE_IPV6):
311 		parser->ip6 = ptr;
312 		ptr = (uint8_t *)ptr + sizeof(*parser->ip6);
313 		if (update_data) {
314 			parser->data.s_addr.v6 = parser->ip6->ip6_src;
315 			parser->data.d_addr.v6 = parser->ip6->ip6_dst;
316 		}
317 		switch (parser->ip6->ip6_nxt) {
318 		case IPPROTO_UDP:
319 			parser->udp = ptr;
320 			if (update_data) {
321 				parser->data.lro_type = LRO_TYPE_IPV6_UDP;
322 				parser->data.s_port = parser->udp->uh_sport;
323 				parser->data.d_port = parser->udp->uh_dport;
324 			} else {
325 				MPASS(parser->data.lro_type == LRO_TYPE_IPV6_UDP);
326 			}
327 			ptr = (uint8_t *)ptr + sizeof(*parser->udp);
328 			parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
329 			return (ptr);
330 		case IPPROTO_TCP:
331 			parser->tcp = ptr;
332 			if (update_data) {
333 				parser->data.lro_type = LRO_TYPE_IPV6_TCP;
334 				parser->data.s_port = parser->tcp->th_sport;
335 				parser->data.d_port = parser->tcp->th_dport;
336 			} else {
337 				MPASS(parser->data.lro_type == LRO_TYPE_IPV6_TCP);
338 			}
339 			ptr = (uint8_t *)ptr + (parser->tcp->th_off << 2);
340 			parser->total_hdr_len = (uint8_t *)ptr - (uint8_t *)old;
341 			return (ptr);
342 		default:
343 			break;
344 		}
345 		break;
346 #endif
347 	default:
348 		break;
349 	}
350 	/* Invalid packet - cannot parse */
351 	return (NULL);
352 }
353 
354 static const int vxlan_csum = CSUM_INNER_L3_CALC | CSUM_INNER_L3_VALID |
355     CSUM_INNER_L4_CALC | CSUM_INNER_L4_VALID;
356 
357 static inline struct lro_parser *
358 tcp_lro_parser(struct mbuf *m, struct lro_parser *po, struct lro_parser *pi, bool update_data)
359 {
360 	void *data_ptr;
361 
362 	/* Try to parse outer headers first. */
363 	data_ptr = tcp_lro_low_level_parser(m->m_data, po, update_data, false);
364 	if (data_ptr == NULL || po->total_hdr_len > m->m_len)
365 		return (NULL);
366 
367 	if (update_data) {
368 		/* Store VLAN ID, if any. */
369 		if (__predict_false(m->m_flags & M_VLANTAG)) {
370 			po->data.vlan_id =
371 			    htons(m->m_pkthdr.ether_vtag) & htons(EVL_VLID_MASK);
372 		}
373 	}
374 
375 	switch (po->data.lro_type) {
376 	case LRO_TYPE_IPV4_UDP:
377 	case LRO_TYPE_IPV6_UDP:
378 		/* Check for VXLAN headers. */
379 		if ((m->m_pkthdr.csum_flags & vxlan_csum) != vxlan_csum)
380 			break;
381 
382 		/* Try to parse inner headers. */
383 		data_ptr = tcp_lro_low_level_parser(data_ptr, pi, update_data, true);
384 		if (data_ptr == NULL || pi->total_hdr_len > m->m_len)
385 			break;
386 
387 		/* Verify supported header types. */
388 		switch (pi->data.lro_type) {
389 		case LRO_TYPE_IPV4_TCP:
390 		case LRO_TYPE_IPV6_TCP:
391 			return (pi);
392 		default:
393 			break;
394 		}
395 		break;
396 	case LRO_TYPE_IPV4_TCP:
397 	case LRO_TYPE_IPV6_TCP:
398 		if (update_data)
399 			memset(pi, 0, sizeof(*pi));
400 		return (po);
401 	default:
402 		break;
403 	}
404 	return (NULL);
405 }
406 
407 static inline int
408 tcp_lro_trim_mbuf_chain(struct mbuf *m, const struct lro_parser *po)
409 {
410 	int len;
411 
412 	switch (po->data.lro_type) {
413 #ifdef INET
414 	case LRO_TYPE_IPV4_TCP:
415 		len = ((uint8_t *)po->ip4 - (uint8_t *)m->m_data) +
416 		    ntohs(po->ip4->ip_len);
417 		break;
418 #endif
419 #ifdef INET6
420 	case LRO_TYPE_IPV6_TCP:
421 		len = ((uint8_t *)po->ip6 - (uint8_t *)m->m_data) +
422 		    ntohs(po->ip6->ip6_plen) + sizeof(*po->ip6);
423 		break;
424 #endif
425 	default:
426 		return (TCP_LRO_CANNOT);
427 	}
428 
429 	/*
430 	 * If the frame is padded beyond the end of the IP packet,
431 	 * then trim the extra bytes off:
432 	 */
433 	if (__predict_true(m->m_pkthdr.len == len)) {
434 		return (0);
435 	} else if (m->m_pkthdr.len > len) {
436 		m_adj(m, len - m->m_pkthdr.len);
437 		return (0);
438 	}
439 	return (TCP_LRO_CANNOT);
440 }
441 
442 static struct tcphdr *
443 tcp_lro_get_th(struct mbuf *m)
444 {
445 	return ((struct tcphdr *)((uint8_t *)m->m_data + m->m_pkthdr.lro_tcp_h_off));
446 }
447 
448 static void
449 lro_free_mbuf_chain(struct mbuf *m)
450 {
451 	struct mbuf *save;
452 
453 	while (m) {
454 		save = m->m_nextpkt;
455 		m->m_nextpkt = NULL;
456 		m_freem(m);
457 		m = save;
458 	}
459 }
460 
461 void
462 tcp_lro_free(struct lro_ctrl *lc)
463 {
464 	struct lro_entry *le;
465 	unsigned x;
466 
467 	/* reset LRO free list */
468 	LIST_INIT(&lc->lro_free);
469 
470 	/* free active mbufs, if any */
471 	while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
472 		tcp_lro_active_remove(le);
473 		lro_free_mbuf_chain(le->m_head);
474 	}
475 
476 	/* free hash table */
477 	free(lc->lro_hash, M_LRO);
478 	lc->lro_hash = NULL;
479 	lc->lro_hashsz = 0;
480 
481 	/* free mbuf array, if any */
482 	for (x = 0; x != lc->lro_mbuf_count; x++)
483 		m_freem(lc->lro_mbuf_data[x].mb);
484 	lc->lro_mbuf_count = 0;
485 
486 	/* free allocated memory, if any */
487 	free(lc->lro_mbuf_data, M_LRO);
488 	lc->lro_mbuf_data = NULL;
489 }
490 
491 static uint16_t
492 tcp_lro_rx_csum_tcphdr(const struct tcphdr *th)
493 {
494 	const uint16_t *ptr;
495 	uint32_t csum;
496 	uint16_t len;
497 
498 	csum = -th->th_sum;	/* exclude checksum field */
499 	len = th->th_off;
500 	ptr = (const uint16_t *)th;
501 	while (len--) {
502 		csum += *ptr;
503 		ptr++;
504 		csum += *ptr;
505 		ptr++;
506 	}
507 	while (csum > 0xffff)
508 		csum = (csum >> 16) + (csum & 0xffff);
509 
510 	return (csum);
511 }
512 
513 static uint16_t
514 tcp_lro_rx_csum_data(const struct lro_parser *pa, uint16_t tcp_csum)
515 {
516 	uint32_t c;
517 	uint16_t cs;
518 
519 	c = tcp_csum;
520 
521 	switch (pa->data.lro_type) {
522 #ifdef INET6
523 	case LRO_TYPE_IPV6_TCP:
524 		/* Compute full pseudo IPv6 header checksum. */
525 		cs = in6_cksum_pseudo(pa->ip6, ntohs(pa->ip6->ip6_plen), pa->ip6->ip6_nxt, 0);
526 		break;
527 #endif
528 #ifdef INET
529 	case LRO_TYPE_IPV4_TCP:
530 		/* Compute full pseudo IPv4 header checsum. */
531 		cs = in_addword(ntohs(pa->ip4->ip_len) - sizeof(*pa->ip4), IPPROTO_TCP);
532 		cs = in_pseudo(pa->ip4->ip_src.s_addr, pa->ip4->ip_dst.s_addr, htons(cs));
533 		break;
534 #endif
535 	default:
536 		cs = 0;		/* Keep compiler happy. */
537 		break;
538 	}
539 
540 	/* Complement checksum. */
541 	cs = ~cs;
542 	c += cs;
543 
544 	/* Remove TCP header checksum. */
545 	cs = ~tcp_lro_rx_csum_tcphdr(pa->tcp);
546 	c += cs;
547 
548 	/* Compute checksum remainder. */
549 	while (c > 0xffff)
550 		c = (c >> 16) + (c & 0xffff);
551 
552 	return (c);
553 }
554 
555 static void
556 tcp_lro_rx_done(struct lro_ctrl *lc)
557 {
558 	struct lro_entry *le;
559 
560 	while ((le = LIST_FIRST(&lc->lro_active)) != NULL) {
561 		tcp_lro_active_remove(le);
562 		tcp_lro_flush(lc, le);
563 	}
564 }
565 
566 void
567 tcp_lro_flush_inactive(struct lro_ctrl *lc, const struct timeval *timeout)
568 {
569 	struct lro_entry *le, *le_tmp;
570 	uint64_t now, tov;
571 	struct bintime bt;
572 
573 	if (LIST_EMPTY(&lc->lro_active))
574 		return;
575 
576 	/* get timeout time and current time in ns */
577 	binuptime(&bt);
578 	now = bintime2ns(&bt);
579 	tov = ((timeout->tv_sec * 1000000000) + (timeout->tv_usec * 1000));
580 	LIST_FOREACH_SAFE(le, &lc->lro_active, next, le_tmp) {
581 		if (now >= (bintime2ns(&le->alloc_time) + tov)) {
582 			tcp_lro_active_remove(le);
583 			tcp_lro_flush(lc, le);
584 		}
585 	}
586 }
587 
588 #ifdef INET
589 static int
590 tcp_lro_rx_ipv4(struct lro_ctrl *lc, struct mbuf *m, struct ip *ip4)
591 {
592 	uint16_t csum;
593 
594 	/* Legacy IP has a header checksum that needs to be correct. */
595 	if (m->m_pkthdr.csum_flags & CSUM_IP_CHECKED) {
596 		if (__predict_false((m->m_pkthdr.csum_flags & CSUM_IP_VALID) == 0)) {
597 			lc->lro_bad_csum++;
598 			return (TCP_LRO_CANNOT);
599 		}
600 	} else {
601 		csum = in_cksum_hdr(ip4);
602 		if (__predict_false(csum != 0)) {
603 			lc->lro_bad_csum++;
604 			return (TCP_LRO_CANNOT);
605 		}
606 	}
607 	return (0);
608 }
609 #endif
610 
611 #ifdef TCPHPTS
612 static void
613 tcp_lro_log(struct tcpcb *tp, const struct lro_ctrl *lc,
614     const struct lro_entry *le, const struct mbuf *m,
615     int frm, int32_t tcp_data_len, uint32_t th_seq,
616     uint32_t th_ack, uint16_t th_win)
617 {
618 	if (tp->t_logstate != TCP_LOG_STATE_OFF) {
619 		union tcp_log_stackspecific log;
620 		struct timeval tv, btv;
621 		uint32_t cts;
622 
623 		cts = tcp_get_usecs(&tv);
624 		memset(&log, 0, sizeof(union tcp_log_stackspecific));
625 		log.u_bbr.flex8 = frm;
626 		log.u_bbr.flex1 = tcp_data_len;
627 		if (m)
628 			log.u_bbr.flex2 = m->m_pkthdr.len;
629 		else
630 			log.u_bbr.flex2 = 0;
631 		log.u_bbr.flex3 = le->m_head->m_pkthdr.lro_nsegs;
632 		log.u_bbr.flex4 = le->m_head->m_pkthdr.lro_tcp_d_len;
633 		if (le->m_head) {
634 			log.u_bbr.flex5 = le->m_head->m_pkthdr.len;
635 			log.u_bbr.delRate = le->m_head->m_flags;
636 			log.u_bbr.rttProp = le->m_head->m_pkthdr.rcv_tstmp;
637 		}
638 		log.u_bbr.inflight = th_seq;
639 		log.u_bbr.delivered = th_ack;
640 		log.u_bbr.timeStamp = cts;
641 		log.u_bbr.epoch = le->next_seq;
642 		log.u_bbr.lt_epoch = le->ack_seq;
643 		log.u_bbr.pacing_gain = th_win;
644 		log.u_bbr.cwnd_gain = le->window;
645 		log.u_bbr.lost = curcpu;
646 		log.u_bbr.cur_del_rate = (uintptr_t)m;
647 		log.u_bbr.bw_inuse = (uintptr_t)le->m_head;
648 		bintime2timeval(&lc->lro_last_queue_time, &btv);
649 		log.u_bbr.flex6 = tcp_tv_to_usectick(&btv);
650 		log.u_bbr.flex7 = le->compressed;
651 		log.u_bbr.pacing_gain = le->uncompressed;
652 		if (in_epoch(net_epoch_preempt))
653 			log.u_bbr.inhpts = 1;
654 		else
655 			log.u_bbr.inhpts = 0;
656 		TCP_LOG_EVENTP(tp, NULL,
657 			       &tp->t_inpcb->inp_socket->so_rcv,
658 			       &tp->t_inpcb->inp_socket->so_snd,
659 			       TCP_LOG_LRO, 0,
660 			       0, &log, false, &tv);
661 	}
662 }
663 #endif
664 
665 static inline void
666 tcp_lro_assign_and_checksum_16(uint16_t *ptr, uint16_t value, uint16_t *psum)
667 {
668 	uint32_t csum;
669 
670 	csum = 0xffff - *ptr + value;
671 	while (csum > 0xffff)
672 		csum = (csum >> 16) + (csum & 0xffff);
673 	*ptr = value;
674 	*psum = csum;
675 }
676 
677 static uint16_t
678 tcp_lro_update_checksum(const struct lro_parser *pa, const struct lro_entry *le,
679     uint16_t payload_len, uint16_t delta_sum)
680 {
681 	uint32_t csum;
682 	uint16_t tlen;
683 	uint16_t temp[5] = {};
684 
685 	switch (pa->data.lro_type) {
686 	case LRO_TYPE_IPV4_TCP:
687 		/* Compute new IPv4 length. */
688 		tlen = (pa->ip4->ip_hl << 2) + (pa->tcp->th_off << 2) + payload_len;
689 		tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
690 
691 		/* Subtract delta from current IPv4 checksum. */
692 		csum = pa->ip4->ip_sum + 0xffff - temp[0];
693 		while (csum > 0xffff)
694 			csum = (csum >> 16) + (csum & 0xffff);
695 		tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
696 		goto update_tcp_header;
697 
698 	case LRO_TYPE_IPV6_TCP:
699 		/* Compute new IPv6 length. */
700 		tlen = (pa->tcp->th_off << 2) + payload_len;
701 		tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
702 		goto update_tcp_header;
703 
704 	case LRO_TYPE_IPV4_UDP:
705 		/* Compute new IPv4 length. */
706 		tlen = (pa->ip4->ip_hl << 2) + sizeof(*pa->udp) + payload_len;
707 		tcp_lro_assign_and_checksum_16(&pa->ip4->ip_len, htons(tlen), &temp[0]);
708 
709 		/* Subtract delta from current IPv4 checksum. */
710 		csum = pa->ip4->ip_sum + 0xffff - temp[0];
711 		while (csum > 0xffff)
712 			csum = (csum >> 16) + (csum & 0xffff);
713 		tcp_lro_assign_and_checksum_16(&pa->ip4->ip_sum, csum, &temp[1]);
714 		goto update_udp_header;
715 
716 	case LRO_TYPE_IPV6_UDP:
717 		/* Compute new IPv6 length. */
718 		tlen = sizeof(*pa->udp) + payload_len;
719 		tcp_lro_assign_and_checksum_16(&pa->ip6->ip6_plen, htons(tlen), &temp[0]);
720 		goto update_udp_header;
721 
722 	default:
723 		return (0);
724 	}
725 
726 update_tcp_header:
727 	/* Compute current TCP header checksum. */
728 	temp[2] = tcp_lro_rx_csum_tcphdr(pa->tcp);
729 
730 	/* Incorporate the latest ACK into the TCP header. */
731 	pa->tcp->th_ack = le->ack_seq;
732 	pa->tcp->th_win = le->window;
733 
734 	/* Incorporate latest timestamp into the TCP header. */
735 	if (le->timestamp != 0) {
736 		uint32_t *ts_ptr;
737 
738 		ts_ptr = (uint32_t *)(pa->tcp + 1);
739 		ts_ptr[1] = htonl(le->tsval);
740 		ts_ptr[2] = le->tsecr;
741 	}
742 
743 	/* Compute new TCP header checksum. */
744 	temp[3] = tcp_lro_rx_csum_tcphdr(pa->tcp);
745 
746 	/* Compute new TCP checksum. */
747 	csum = pa->tcp->th_sum + 0xffff - delta_sum +
748 	    0xffff - temp[0] + 0xffff - temp[3] + temp[2];
749 	while (csum > 0xffff)
750 		csum = (csum >> 16) + (csum & 0xffff);
751 
752 	/* Assign new TCP checksum. */
753 	tcp_lro_assign_and_checksum_16(&pa->tcp->th_sum, csum, &temp[4]);
754 
755 	/* Compute all modififications affecting next checksum. */
756 	csum = temp[0] + temp[1] + 0xffff - temp[2] +
757 	    temp[3] + temp[4] + delta_sum;
758 	while (csum > 0xffff)
759 		csum = (csum >> 16) + (csum & 0xffff);
760 
761 	/* Return delta checksum to next stage, if any. */
762 	return (csum);
763 
764 update_udp_header:
765 	tlen = sizeof(*pa->udp) + payload_len;
766 	/* Assign new UDP length and compute checksum delta. */
767 	tcp_lro_assign_and_checksum_16(&pa->udp->uh_ulen, htons(tlen), &temp[2]);
768 
769 	/* Check if there is a UDP checksum. */
770 	if (__predict_false(pa->udp->uh_sum != 0)) {
771 		/* Compute new UDP checksum. */
772 		csum = pa->udp->uh_sum + 0xffff - delta_sum +
773 		    0xffff - temp[0] + 0xffff - temp[2];
774 		while (csum > 0xffff)
775 			csum = (csum >> 16) + (csum & 0xffff);
776 		/* Assign new UDP checksum. */
777 		tcp_lro_assign_and_checksum_16(&pa->udp->uh_sum, csum, &temp[3]);
778 	}
779 
780 	/* Compute all modififications affecting next checksum. */
781 	csum = temp[0] + temp[1] + temp[2] + temp[3] + delta_sum;
782 	while (csum > 0xffff)
783 		csum = (csum >> 16) + (csum & 0xffff);
784 
785 	/* Return delta checksum to next stage, if any. */
786 	return (csum);
787 }
788 
789 static void
790 tcp_flush_out_entry(struct lro_ctrl *lc, struct lro_entry *le)
791 {
792 	/* Check if we need to recompute any checksums. */
793 	if (le->m_head->m_pkthdr.lro_nsegs > 1) {
794 		uint16_t csum;
795 
796 		switch (le->inner.data.lro_type) {
797 		case LRO_TYPE_IPV4_TCP:
798 			csum = tcp_lro_update_checksum(&le->inner, le,
799 			    le->m_head->m_pkthdr.lro_tcp_d_len,
800 			    le->m_head->m_pkthdr.lro_tcp_d_csum);
801 			csum = tcp_lro_update_checksum(&le->outer, NULL,
802 			    le->m_head->m_pkthdr.lro_tcp_d_len +
803 			    le->inner.total_hdr_len, csum);
804 			le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
805 			    CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
806 			le->m_head->m_pkthdr.csum_data = 0xffff;
807 			break;
808 		case LRO_TYPE_IPV6_TCP:
809 			csum = tcp_lro_update_checksum(&le->inner, le,
810 			    le->m_head->m_pkthdr.lro_tcp_d_len,
811 			    le->m_head->m_pkthdr.lro_tcp_d_csum);
812 			csum = tcp_lro_update_checksum(&le->outer, NULL,
813 			    le->m_head->m_pkthdr.lro_tcp_d_len +
814 			    le->inner.total_hdr_len, csum);
815 			le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
816 			    CSUM_PSEUDO_HDR;
817 			le->m_head->m_pkthdr.csum_data = 0xffff;
818 			break;
819 		case LRO_TYPE_NONE:
820 			switch (le->outer.data.lro_type) {
821 			case LRO_TYPE_IPV4_TCP:
822 				csum = tcp_lro_update_checksum(&le->outer, le,
823 				    le->m_head->m_pkthdr.lro_tcp_d_len,
824 				    le->m_head->m_pkthdr.lro_tcp_d_csum);
825 				le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
826 				    CSUM_PSEUDO_HDR | CSUM_IP_CHECKED | CSUM_IP_VALID;
827 				le->m_head->m_pkthdr.csum_data = 0xffff;
828 				break;
829 			case LRO_TYPE_IPV6_TCP:
830 				csum = tcp_lro_update_checksum(&le->outer, le,
831 				    le->m_head->m_pkthdr.lro_tcp_d_len,
832 				    le->m_head->m_pkthdr.lro_tcp_d_csum);
833 				le->m_head->m_pkthdr.csum_flags = CSUM_DATA_VALID |
834 				    CSUM_PSEUDO_HDR;
835 				le->m_head->m_pkthdr.csum_data = 0xffff;
836 				break;
837 			default:
838 				break;
839 			}
840 			break;
841 		default:
842 			break;
843 		}
844 	}
845 
846 	/*
847 	 * Break any chain, this is not set to NULL on the singleton
848 	 * case m_nextpkt points to m_head. Other case set them
849 	 * m_nextpkt to NULL in push_and_replace.
850 	 */
851 	le->m_head->m_nextpkt = NULL;
852 	lc->lro_queued += le->m_head->m_pkthdr.lro_nsegs;
853 	(*lc->ifp->if_input)(lc->ifp, le->m_head);
854 }
855 
856 static void
857 tcp_set_entry_to_mbuf(struct lro_ctrl *lc, struct lro_entry *le,
858     struct mbuf *m, struct tcphdr *th)
859 {
860 	uint32_t *ts_ptr;
861 	uint16_t tcp_data_len;
862 	uint16_t tcp_opt_len;
863 
864 	ts_ptr = (uint32_t *)(th + 1);
865 	tcp_opt_len = (th->th_off << 2);
866 	tcp_opt_len -= sizeof(*th);
867 
868 	/* Check if there is a timestamp option. */
869 	if (tcp_opt_len == 0 ||
870 	    __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
871 	    *ts_ptr != TCP_LRO_TS_OPTION)) {
872 		/* We failed to find the timestamp option. */
873 		le->timestamp = 0;
874 	} else {
875 		le->timestamp = 1;
876 		le->tsval = ntohl(*(ts_ptr + 1));
877 		le->tsecr = *(ts_ptr + 2);
878 	}
879 
880 	tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
881 
882 	/* Pull out TCP sequence numbers and window size. */
883 	le->next_seq = ntohl(th->th_seq) + tcp_data_len;
884 	le->ack_seq = th->th_ack;
885 	le->window = th->th_win;
886 
887 	/* Setup new data pointers. */
888 	le->m_head = m;
889 	le->m_tail = m_last(m);
890 }
891 
892 static void
893 tcp_push_and_replace(struct lro_ctrl *lc, struct lro_entry *le, struct mbuf *m)
894 {
895 	struct lro_parser *pa;
896 
897 	/*
898 	 * Push up the stack of the current entry
899 	 * and replace it with "m".
900 	 */
901 	struct mbuf *msave;
902 
903 	/* Grab off the next and save it */
904 	msave = le->m_head->m_nextpkt;
905 	le->m_head->m_nextpkt = NULL;
906 
907 	/* Now push out the old entry */
908 	tcp_flush_out_entry(lc, le);
909 
910 	/* Re-parse new header, should not fail. */
911 	pa = tcp_lro_parser(m, &le->outer, &le->inner, false);
912 	KASSERT(pa != NULL,
913 	    ("tcp_push_and_replace: LRO parser failed on m=%p\n", m));
914 
915 	/*
916 	 * Now to replace the data properly in the entry
917 	 * we have to reset the TCP header and
918 	 * other fields.
919 	 */
920 	tcp_set_entry_to_mbuf(lc, le, m, pa->tcp);
921 
922 	/* Restore the next list */
923 	m->m_nextpkt = msave;
924 }
925 
926 static void
927 tcp_lro_mbuf_append_pkthdr(struct mbuf *m, const struct mbuf *p)
928 {
929 	uint32_t csum;
930 
931 	if (m->m_pkthdr.lro_nsegs == 1) {
932 		/* Compute relative checksum. */
933 		csum = p->m_pkthdr.lro_tcp_d_csum;
934 	} else {
935 		/* Merge TCP data checksums. */
936 		csum = (uint32_t)m->m_pkthdr.lro_tcp_d_csum +
937 		    (uint32_t)p->m_pkthdr.lro_tcp_d_csum;
938 		while (csum > 0xffff)
939 			csum = (csum >> 16) + (csum & 0xffff);
940 	}
941 
942 	/* Update various counters. */
943 	m->m_pkthdr.len += p->m_pkthdr.lro_tcp_d_len;
944 	m->m_pkthdr.lro_tcp_d_csum = csum;
945 	m->m_pkthdr.lro_tcp_d_len += p->m_pkthdr.lro_tcp_d_len;
946 	m->m_pkthdr.lro_nsegs += p->m_pkthdr.lro_nsegs;
947 }
948 
949 static void
950 tcp_lro_condense(struct lro_ctrl *lc, struct lro_entry *le)
951 {
952 	/*
953 	 * Walk through the mbuf chain we
954 	 * have on tap and compress/condense
955 	 * as required.
956 	 */
957 	uint32_t *ts_ptr;
958 	struct mbuf *m;
959 	struct tcphdr *th;
960 	uint32_t tcp_data_len_total;
961 	uint32_t tcp_data_seg_total;
962 	uint16_t tcp_data_len;
963 	uint16_t tcp_opt_len;
964 
965 	/*
966 	 * First we must check the lead (m_head)
967 	 * we must make sure that it is *not*
968 	 * something that should be sent up
969 	 * right away (sack etc).
970 	 */
971 again:
972 	m = le->m_head->m_nextpkt;
973 	if (m == NULL) {
974 		/* Just one left. */
975 		return;
976 	}
977 
978 	th = tcp_lro_get_th(m);
979 	tcp_opt_len = (th->th_off << 2);
980 	tcp_opt_len -= sizeof(*th);
981 	ts_ptr = (uint32_t *)(th + 1);
982 
983 	if (tcp_opt_len != 0 && __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
984 	    *ts_ptr != TCP_LRO_TS_OPTION)) {
985 		/*
986 		 * Its not the timestamp. We can't
987 		 * use this guy as the head.
988 		 */
989 		le->m_head->m_nextpkt = m->m_nextpkt;
990 		tcp_push_and_replace(lc, le, m);
991 		goto again;
992 	}
993 	if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
994 		/*
995 		 * Make sure that previously seen segements/ACKs are delivered
996 		 * before this segment, e.g. FIN.
997 		 */
998 		le->m_head->m_nextpkt = m->m_nextpkt;
999 		tcp_push_and_replace(lc, le, m);
1000 		goto again;
1001 	}
1002 	while((m = le->m_head->m_nextpkt) != NULL) {
1003 		/*
1004 		 * condense m into le, first
1005 		 * pull m out of the list.
1006 		 */
1007 		le->m_head->m_nextpkt = m->m_nextpkt;
1008 		m->m_nextpkt = NULL;
1009 		/* Setup my data */
1010 		tcp_data_len = m->m_pkthdr.lro_tcp_d_len;
1011 		th = tcp_lro_get_th(m);
1012 		ts_ptr = (uint32_t *)(th + 1);
1013 		tcp_opt_len = (th->th_off << 2);
1014 		tcp_opt_len -= sizeof(*th);
1015 		tcp_data_len_total = le->m_head->m_pkthdr.lro_tcp_d_len + tcp_data_len;
1016 		tcp_data_seg_total = le->m_head->m_pkthdr.lro_nsegs + m->m_pkthdr.lro_nsegs;
1017 
1018 		if (tcp_data_seg_total >= lc->lro_ackcnt_lim ||
1019 		    tcp_data_len_total >= lc->lro_length_lim) {
1020 			/* Flush now if appending will result in overflow. */
1021 			tcp_push_and_replace(lc, le, m);
1022 			goto again;
1023 		}
1024 		if (tcp_opt_len != 0 &&
1025 		    __predict_false(tcp_opt_len != TCPOLEN_TSTAMP_APPA ||
1026 		    *ts_ptr != TCP_LRO_TS_OPTION)) {
1027 			/*
1028 			 * Maybe a sack in the new one? We need to
1029 			 * start all over after flushing the
1030 			 * current le. We will go up to the beginning
1031 			 * and flush it (calling the replace again possibly
1032 			 * or just returning).
1033 			 */
1034 			tcp_push_and_replace(lc, le, m);
1035 			goto again;
1036 		}
1037 		if ((th->th_flags & ~(TH_ACK | TH_PUSH)) != 0) {
1038 			tcp_push_and_replace(lc, le, m);
1039 			goto again;
1040 		}
1041 		if (tcp_opt_len != 0) {
1042 			uint32_t tsval = ntohl(*(ts_ptr + 1));
1043 			/* Make sure timestamp values are increasing. */
1044 			if (TSTMP_GT(le->tsval, tsval))  {
1045 				tcp_push_and_replace(lc, le, m);
1046 				goto again;
1047 			}
1048 			le->tsval = tsval;
1049 			le->tsecr = *(ts_ptr + 2);
1050 		}
1051 		/* Try to append the new segment. */
1052 		if (__predict_false(ntohl(th->th_seq) != le->next_seq ||
1053 				    (tcp_data_len == 0 &&
1054 				     le->ack_seq == th->th_ack &&
1055 				     le->window == th->th_win))) {
1056 			/* Out of order packet or duplicate ACK. */
1057 			tcp_push_and_replace(lc, le, m);
1058 			goto again;
1059 		}
1060 		if (tcp_data_len != 0 ||
1061 		    SEQ_GT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1062 			le->next_seq += tcp_data_len;
1063 			le->ack_seq = th->th_ack;
1064 			le->window = th->th_win;
1065 		} else if (th->th_ack == le->ack_seq) {
1066 			le->window = WIN_MAX(le->window, th->th_win);
1067 		}
1068 
1069 		if (tcp_data_len == 0) {
1070 			m_freem(m);
1071 			continue;
1072 		}
1073 
1074 		/* Merge TCP data checksum and length to head mbuf. */
1075 		tcp_lro_mbuf_append_pkthdr(le->m_head, m);
1076 
1077 		/*
1078 		 * Adjust the mbuf so that m_data points to the first byte of
1079 		 * the ULP payload.  Adjust the mbuf to avoid complications and
1080 		 * append new segment to existing mbuf chain.
1081 		 */
1082 		m_adj(m, m->m_pkthdr.len - tcp_data_len);
1083 		m_demote_pkthdr(m);
1084 		le->m_tail->m_next = m;
1085 		le->m_tail = m_last(m);
1086 	}
1087 }
1088 
1089 #ifdef TCPHPTS
1090 static void
1091 tcp_queue_pkts(struct inpcb *inp, struct tcpcb *tp, struct lro_entry *le)
1092 {
1093 	INP_WLOCK_ASSERT(inp);
1094 	if (tp->t_in_pkt == NULL) {
1095 		/* Nothing yet there */
1096 		tp->t_in_pkt = le->m_head;
1097 		tp->t_tail_pkt = le->m_last_mbuf;
1098 	} else {
1099 		/* Already some there */
1100 		tp->t_tail_pkt->m_nextpkt = le->m_head;
1101 		tp->t_tail_pkt = le->m_last_mbuf;
1102 	}
1103 	le->m_head = NULL;
1104 	le->m_last_mbuf = NULL;
1105 }
1106 
1107 static struct mbuf *
1108 tcp_lro_get_last_if_ackcmp(struct lro_ctrl *lc, struct lro_entry *le,
1109     struct inpcb *inp, int32_t *new_m)
1110 {
1111 	struct tcpcb *tp;
1112 	struct mbuf *m;
1113 
1114 	tp = intotcpcb(inp);
1115 	if (__predict_false(tp == NULL))
1116 		return (NULL);
1117 
1118 	/* Look at the last mbuf if any in queue */
1119 	m = tp->t_tail_pkt;
1120 	if (m != NULL && (m->m_flags & M_ACKCMP) != 0) {
1121 		if (M_TRAILINGSPACE(m) >= sizeof(struct tcp_ackent)) {
1122 			tcp_lro_log(tp, lc, le, NULL, 23, 0, 0, 0, 0);
1123 			*new_m = 0;
1124 			counter_u64_add(tcp_extra_mbuf, 1);
1125 			return (m);
1126 		} else {
1127 			/* Mark we ran out of space */
1128 			inp->inp_flags2 |= INP_MBUF_L_ACKS;
1129 		}
1130 	}
1131 	/* Decide mbuf size. */
1132 	if (inp->inp_flags2 & INP_MBUF_L_ACKS)
1133 		m = m_getcl(M_NOWAIT, MT_DATA, M_ACKCMP | M_PKTHDR);
1134 	else
1135 		m = m_gethdr(M_NOWAIT, MT_DATA);
1136 
1137 	if (__predict_false(m == NULL)) {
1138 		counter_u64_add(tcp_would_have_but, 1);
1139 		return (NULL);
1140 	}
1141 	counter_u64_add(tcp_comp_total, 1);
1142 	m->m_flags |= M_ACKCMP;
1143 	*new_m = 1;
1144 	return (m);
1145 }
1146 
1147 static struct inpcb *
1148 tcp_lro_lookup(struct ifnet *ifp, struct lro_parser *pa)
1149 {
1150 	struct inpcb *inp;
1151 
1152 	NET_EPOCH_ASSERT();
1153 
1154 	switch (pa->data.lro_type) {
1155 #ifdef INET6
1156 	case LRO_TYPE_IPV6_TCP:
1157 		inp = in6_pcblookup(&V_tcbinfo,
1158 		    &pa->data.s_addr.v6,
1159 		    pa->data.s_port,
1160 		    &pa->data.d_addr.v6,
1161 		    pa->data.d_port,
1162 		    INPLOOKUP_WLOCKPCB,
1163 		    ifp);
1164 		break;
1165 #endif
1166 #ifdef INET
1167 	case LRO_TYPE_IPV4_TCP:
1168 		inp = in_pcblookup(&V_tcbinfo,
1169 		    pa->data.s_addr.v4,
1170 		    pa->data.s_port,
1171 		    pa->data.d_addr.v4,
1172 		    pa->data.d_port,
1173 		    INPLOOKUP_WLOCKPCB,
1174 		    ifp);
1175 		break;
1176 #endif
1177 	default:
1178 		inp = NULL;
1179 		break;
1180 	}
1181 	return (inp);
1182 }
1183 
1184 static inline bool
1185 tcp_lro_ack_valid(struct mbuf *m, struct tcphdr *th, uint32_t **ppts, bool *other_opts)
1186 {
1187 	/*
1188 	 * This function returns two bits of valuable information.
1189 	 * a) Is what is present capable of being ack-compressed,
1190 	 *    we can ack-compress if there is no options or just
1191 	 *    a timestamp option, and of course the th_flags must
1192 	 *    be correct as well.
1193 	 * b) Our other options present such as SACK. This is
1194 	 *    used to determine if we want to wakeup or not.
1195 	 */
1196 	bool ret = true;
1197 
1198 	switch (th->th_off << 2) {
1199 	case (sizeof(*th) + TCPOLEN_TSTAMP_APPA):
1200 		*ppts = (uint32_t *)(th + 1);
1201 		/* Check if we have only one timestamp option. */
1202 		if (**ppts == TCP_LRO_TS_OPTION)
1203 			*other_opts = false;
1204 		else {
1205 			*other_opts = true;
1206 			ret = false;
1207 		}
1208 		break;
1209 	case (sizeof(*th)):
1210 		/* No options. */
1211 		*ppts = NULL;
1212 		*other_opts = false;
1213 		break;
1214 	default:
1215 		*ppts = NULL;
1216 		*other_opts = true;
1217 		ret = false;
1218 		break;
1219 	}
1220 	/* For ACKCMP we only accept ACK, PUSH, ECE and CWR. */
1221 	if ((th->th_flags & ~(TH_ACK | TH_PUSH | TH_ECE | TH_CWR)) != 0)
1222 		ret = false;
1223 	/* If it has data on it we cannot compress it */
1224 	if (m->m_pkthdr.lro_tcp_d_len)
1225 		ret = false;
1226 
1227 	/* ACK flag must be set. */
1228 	if (!(th->th_flags & TH_ACK))
1229 		ret = false;
1230 	return (ret);
1231 }
1232 
1233 static int
1234 tcp_lro_flush_tcphpts(struct lro_ctrl *lc, struct lro_entry *le)
1235 {
1236 	struct inpcb *inp;
1237 	struct tcpcb *tp;
1238 	struct mbuf **pp, *cmp, *mv_to;
1239 	bool bpf_req, should_wake;
1240 
1241 	/* Check if packet doesn't belongs to our network interface. */
1242 	if ((tcplro_stacks_wanting_mbufq == 0) ||
1243 	    (le->outer.data.vlan_id != 0) ||
1244 	    (le->inner.data.lro_type != LRO_TYPE_NONE))
1245 		return (TCP_LRO_CANNOT);
1246 
1247 #ifdef INET6
1248 	/*
1249 	 * Be proactive about unspecified IPv6 address in source. As
1250 	 * we use all-zero to indicate unbounded/unconnected pcb,
1251 	 * unspecified IPv6 address can be used to confuse us.
1252 	 *
1253 	 * Note that packets with unspecified IPv6 destination is
1254 	 * already dropped in ip6_input.
1255 	 */
1256 	if (__predict_false(le->outer.data.lro_type == LRO_TYPE_IPV6_TCP &&
1257 	    IN6_IS_ADDR_UNSPECIFIED(&le->outer.data.s_addr.v6)))
1258 		return (TCP_LRO_CANNOT);
1259 
1260 	if (__predict_false(le->inner.data.lro_type == LRO_TYPE_IPV6_TCP &&
1261 	    IN6_IS_ADDR_UNSPECIFIED(&le->inner.data.s_addr.v6)))
1262 		return (TCP_LRO_CANNOT);
1263 #endif
1264 	/* Lookup inp, if any. */
1265 	inp = tcp_lro_lookup(lc->ifp,
1266 	    (le->inner.data.lro_type == LRO_TYPE_NONE) ? &le->outer : &le->inner);
1267 	if (inp == NULL)
1268 		return (TCP_LRO_CANNOT);
1269 
1270 	counter_u64_add(tcp_inp_lro_locks_taken, 1);
1271 
1272 	/* Get TCP control structure. */
1273 	tp = intotcpcb(inp);
1274 
1275 	/* Check if the inp is dead, Jim. */
1276 	if (tp == NULL ||
1277 	    (inp->inp_flags & (INP_DROPPED | INP_TIMEWAIT)) ||
1278 	    (inp->inp_flags2 & INP_FREED)) {
1279 		INP_WUNLOCK(inp);
1280 		return (TCP_LRO_CANNOT);
1281 	}
1282 	if ((inp->inp_irq_cpu_set == 0)  && (lc->lro_cpu_is_set == 1)) {
1283 		inp->inp_irq_cpu = lc->lro_last_cpu;
1284 		inp->inp_irq_cpu_set = 1;
1285 	}
1286 	/* Check if the transport doesn't support the needed optimizations. */
1287 	if ((inp->inp_flags2 & (INP_SUPPORTS_MBUFQ | INP_MBUF_ACKCMP)) == 0) {
1288 		INP_WUNLOCK(inp);
1289 		return (TCP_LRO_CANNOT);
1290 	}
1291 
1292 	if (inp->inp_flags2 & INP_MBUF_QUEUE_READY)
1293 		should_wake = false;
1294 	else
1295 		should_wake = true;
1296 	/* Check if packets should be tapped to BPF. */
1297 	bpf_req = bpf_peers_present(lc->ifp->if_bpf);
1298 
1299 	/* Strip and compress all the incoming packets. */
1300 	cmp = NULL;
1301 	for (pp = &le->m_head; *pp != NULL; ) {
1302 		mv_to = NULL;
1303 		if (do_bpf_strip_and_compress(inp, lc, le, pp,
1304 			 &cmp, &mv_to, &should_wake, bpf_req ) == false) {
1305 			/* Advance to next mbuf. */
1306 			pp = &(*pp)->m_nextpkt;
1307 		} else if (mv_to != NULL) {
1308 			/* We are asked to move pp up */
1309 			pp = &mv_to->m_nextpkt;
1310 		}
1311 	}
1312 	/* Update "m_last_mbuf", if any. */
1313 	if (pp == &le->m_head)
1314 		le->m_last_mbuf = *pp;
1315 	else
1316 		le->m_last_mbuf = __containerof(pp, struct mbuf, m_nextpkt);
1317 
1318 	/* Check if any data mbufs left. */
1319 	if (le->m_head != NULL) {
1320 		counter_u64_add(tcp_inp_lro_direct_queue, 1);
1321 		tcp_lro_log(tp, lc, le, NULL, 22, 1,
1322 			    inp->inp_flags2, inp->inp_in_input, 1);
1323 		tcp_queue_pkts(inp, tp, le);
1324 	}
1325 	if (should_wake) {
1326 		/* Wakeup */
1327 		counter_u64_add(tcp_inp_lro_wokeup_queue, 1);
1328 		if ((*tp->t_fb->tfb_do_queued_segments)(inp->inp_socket, tp, 0))
1329 			inp = NULL;
1330 	}
1331 	if (inp != NULL)
1332 		INP_WUNLOCK(inp);
1333 	return (0);	/* Success. */
1334 }
1335 #endif
1336 
1337 void
1338 tcp_lro_flush(struct lro_ctrl *lc, struct lro_entry *le)
1339 {
1340 	/* Only optimise if there are multiple packets waiting. */
1341 #ifdef TCPHPTS
1342 	int error;
1343 
1344 	CURVNET_SET(lc->ifp->if_vnet);
1345 	error = tcp_lro_flush_tcphpts(lc, le);
1346 	CURVNET_RESTORE();
1347 	if (error != 0) {
1348 #endif
1349 		tcp_lro_condense(lc, le);
1350 		tcp_flush_out_entry(lc, le);
1351 #ifdef TCPHPTS
1352 	}
1353 #endif
1354 	lc->lro_flushed++;
1355 	bzero(le, sizeof(*le));
1356 	LIST_INSERT_HEAD(&lc->lro_free, le, next);
1357 }
1358 
1359 #ifdef HAVE_INLINE_FLSLL
1360 #define	tcp_lro_msb_64(x) (1ULL << (flsll(x) - 1))
1361 #else
1362 static inline uint64_t
1363 tcp_lro_msb_64(uint64_t x)
1364 {
1365 	x |= (x >> 1);
1366 	x |= (x >> 2);
1367 	x |= (x >> 4);
1368 	x |= (x >> 8);
1369 	x |= (x >> 16);
1370 	x |= (x >> 32);
1371 	return (x & ~(x >> 1));
1372 }
1373 #endif
1374 
1375 /*
1376  * The tcp_lro_sort() routine is comparable to qsort(), except it has
1377  * a worst case complexity limit of O(MIN(N,64)*N), where N is the
1378  * number of elements to sort and 64 is the number of sequence bits
1379  * available. The algorithm is bit-slicing the 64-bit sequence number,
1380  * sorting one bit at a time from the most significant bit until the
1381  * least significant one, skipping the constant bits. This is
1382  * typically called a radix sort.
1383  */
1384 static void
1385 tcp_lro_sort(struct lro_mbuf_sort *parray, uint32_t size)
1386 {
1387 	struct lro_mbuf_sort temp;
1388 	uint64_t ones;
1389 	uint64_t zeros;
1390 	uint32_t x;
1391 	uint32_t y;
1392 
1393 repeat:
1394 	/* for small arrays insertion sort is faster */
1395 	if (size <= 12) {
1396 		for (x = 1; x < size; x++) {
1397 			temp = parray[x];
1398 			for (y = x; y > 0 && temp.seq < parray[y - 1].seq; y--)
1399 				parray[y] = parray[y - 1];
1400 			parray[y] = temp;
1401 		}
1402 		return;
1403 	}
1404 
1405 	/* compute sequence bits which are constant */
1406 	ones = 0;
1407 	zeros = 0;
1408 	for (x = 0; x != size; x++) {
1409 		ones |= parray[x].seq;
1410 		zeros |= ~parray[x].seq;
1411 	}
1412 
1413 	/* compute bits which are not constant into "ones" */
1414 	ones &= zeros;
1415 	if (ones == 0)
1416 		return;
1417 
1418 	/* pick the most significant bit which is not constant */
1419 	ones = tcp_lro_msb_64(ones);
1420 
1421 	/*
1422 	 * Move entries having cleared sequence bits to the beginning
1423 	 * of the array:
1424 	 */
1425 	for (x = y = 0; y != size; y++) {
1426 		/* skip set bits */
1427 		if (parray[y].seq & ones)
1428 			continue;
1429 		/* swap entries */
1430 		temp = parray[x];
1431 		parray[x] = parray[y];
1432 		parray[y] = temp;
1433 		x++;
1434 	}
1435 
1436 	KASSERT(x != 0 && x != size, ("Memory is corrupted\n"));
1437 
1438 	/* sort zeros */
1439 	tcp_lro_sort(parray, x);
1440 
1441 	/* sort ones */
1442 	parray += x;
1443 	size -= x;
1444 	goto repeat;
1445 }
1446 
1447 void
1448 tcp_lro_flush_all(struct lro_ctrl *lc)
1449 {
1450 	uint64_t seq;
1451 	uint64_t nseq;
1452 	unsigned x;
1453 
1454 	/* check if no mbufs to flush */
1455 	if (lc->lro_mbuf_count == 0)
1456 		goto done;
1457 	if (lc->lro_cpu_is_set == 0) {
1458 		if (lc->lro_last_cpu == curcpu) {
1459 			lc->lro_cnt_of_same_cpu++;
1460 			/* Have we reached the threshold to declare a cpu? */
1461 			if (lc->lro_cnt_of_same_cpu > tcp_lro_cpu_set_thresh)
1462 				lc->lro_cpu_is_set = 1;
1463 		} else {
1464 			lc->lro_last_cpu = curcpu;
1465 			lc->lro_cnt_of_same_cpu = 0;
1466 		}
1467 	}
1468 	CURVNET_SET(lc->ifp->if_vnet);
1469 
1470 	/* get current time */
1471 	binuptime(&lc->lro_last_queue_time);
1472 
1473 	/* sort all mbufs according to stream */
1474 	tcp_lro_sort(lc->lro_mbuf_data, lc->lro_mbuf_count);
1475 
1476 	/* input data into LRO engine, stream by stream */
1477 	seq = 0;
1478 	for (x = 0; x != lc->lro_mbuf_count; x++) {
1479 		struct mbuf *mb;
1480 
1481 		/* get mbuf */
1482 		mb = lc->lro_mbuf_data[x].mb;
1483 
1484 		/* get sequence number, masking away the packet index */
1485 		nseq = lc->lro_mbuf_data[x].seq & (-1ULL << 24);
1486 
1487 		/* check for new stream */
1488 		if (seq != nseq) {
1489 			seq = nseq;
1490 
1491 			/* flush active streams */
1492 			tcp_lro_rx_done(lc);
1493 		}
1494 
1495 		/* add packet to LRO engine */
1496 		if (tcp_lro_rx_common(lc, mb, 0, false) != 0) {
1497 			/* input packet to network layer */
1498 			(*lc->ifp->if_input)(lc->ifp, mb);
1499 			lc->lro_queued++;
1500 			lc->lro_flushed++;
1501 		}
1502 	}
1503 	CURVNET_RESTORE();
1504 done:
1505 	/* flush active streams */
1506 	tcp_lro_rx_done(lc);
1507 
1508 #ifdef TCPHPTS
1509 	tcp_run_hpts();
1510 #endif
1511 	lc->lro_mbuf_count = 0;
1512 }
1513 
1514 #ifdef TCPHPTS
1515 static void
1516 build_ack_entry(struct tcp_ackent *ae, struct tcphdr *th, struct mbuf *m,
1517     uint32_t *ts_ptr, uint16_t iptos)
1518 {
1519 	/*
1520 	 * Given a TCP ACK, summarize it down into the small TCP ACK
1521 	 * entry.
1522 	 */
1523 	ae->timestamp = m->m_pkthdr.rcv_tstmp;
1524 	if (m->m_flags & M_TSTMP_LRO)
1525 		ae->flags = TSTMP_LRO;
1526 	else if (m->m_flags & M_TSTMP)
1527 		ae->flags = TSTMP_HDWR;
1528 	ae->seq = ntohl(th->th_seq);
1529 	ae->ack = ntohl(th->th_ack);
1530 	ae->flags |= th->th_flags;
1531 	if (ts_ptr != NULL) {
1532 		ae->ts_value = ntohl(ts_ptr[1]);
1533 		ae->ts_echo = ntohl(ts_ptr[2]);
1534 		ae->flags |= HAS_TSTMP;
1535 	}
1536 	ae->win = ntohs(th->th_win);
1537 	ae->codepoint = iptos;
1538 }
1539 
1540 /*
1541  * Do BPF tap for either ACK_CMP packets or MBUF QUEUE type packets
1542  * and strip all, but the IPv4/IPv6 header.
1543  */
1544 static bool
1545 do_bpf_strip_and_compress(struct inpcb *inp, struct lro_ctrl *lc,
1546     struct lro_entry *le, struct mbuf **pp, struct mbuf **cmp, struct mbuf **mv_to,
1547     bool *should_wake, bool bpf_req)
1548 {
1549 	union {
1550 		void *ptr;
1551 		struct ip *ip4;
1552 		struct ip6_hdr *ip6;
1553 	} l3;
1554 	struct mbuf *m;
1555 	struct mbuf *nm;
1556 	struct tcphdr *th;
1557 	struct tcp_ackent *ack_ent;
1558 	uint32_t *ts_ptr;
1559 	int32_t n_mbuf;
1560 	bool other_opts, can_compress;
1561 	uint16_t lro_type;
1562 	uint16_t iptos;
1563 	int tcp_hdr_offset;
1564 	int idx;
1565 
1566 	/* Get current mbuf. */
1567 	m = *pp;
1568 
1569 	/* Let the BPF see the packet */
1570 	if (__predict_false(bpf_req))
1571 		ETHER_BPF_MTAP(lc->ifp, m);
1572 
1573 	tcp_hdr_offset = m->m_pkthdr.lro_tcp_h_off;
1574 	lro_type = le->inner.data.lro_type;
1575 	switch (lro_type) {
1576 	case LRO_TYPE_NONE:
1577 		lro_type = le->outer.data.lro_type;
1578 		switch (lro_type) {
1579 		case LRO_TYPE_IPV4_TCP:
1580 			tcp_hdr_offset -= sizeof(*le->outer.ip4);
1581 			m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1582 			break;
1583 		case LRO_TYPE_IPV6_TCP:
1584 			tcp_hdr_offset -= sizeof(*le->outer.ip6);
1585 			m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1586 			break;
1587 		default:
1588 			goto compressed;
1589 		}
1590 		break;
1591 	case LRO_TYPE_IPV4_TCP:
1592 		tcp_hdr_offset -= sizeof(*le->outer.ip4);
1593 		m->m_pkthdr.lro_etype = ETHERTYPE_IP;
1594 		break;
1595 	case LRO_TYPE_IPV6_TCP:
1596 		tcp_hdr_offset -= sizeof(*le->outer.ip6);
1597 		m->m_pkthdr.lro_etype = ETHERTYPE_IPV6;
1598 		break;
1599 	default:
1600 		goto compressed;
1601 	}
1602 
1603 	MPASS(tcp_hdr_offset >= 0);
1604 
1605 	m_adj(m, tcp_hdr_offset);
1606 	m->m_flags |= M_LRO_EHDRSTRP;
1607 	m->m_flags &= ~M_ACKCMP;
1608 	m->m_pkthdr.lro_tcp_h_off -= tcp_hdr_offset;
1609 
1610 	th = tcp_lro_get_th(m);
1611 
1612 	th->th_sum = 0;		/* TCP checksum is valid. */
1613 
1614 	/* Check if ACK can be compressed */
1615 	can_compress = tcp_lro_ack_valid(m, th, &ts_ptr, &other_opts);
1616 
1617 	/* Now lets look at the should wake states */
1618 	if ((other_opts == true) &&
1619 	    ((inp->inp_flags2 & INP_DONT_SACK_QUEUE) == 0)) {
1620 		/*
1621 		 * If there are other options (SACK?) and the
1622 		 * tcp endpoint has not expressly told us it does
1623 		 * not care about SACKS, then we should wake up.
1624 		 */
1625 		*should_wake = true;
1626 	}
1627 	/* Is the ack compressable? */
1628 	if (can_compress == false)
1629 		goto done;
1630 	/* Does the TCP endpoint support ACK compression? */
1631 	if ((inp->inp_flags2 & INP_MBUF_ACKCMP) == 0)
1632 		goto done;
1633 
1634 	/* Lets get the TOS/traffic class field */
1635 	l3.ptr = mtod(m, void *);
1636 	switch (lro_type) {
1637 	case LRO_TYPE_IPV4_TCP:
1638 		iptos = l3.ip4->ip_tos;
1639 		break;
1640 	case LRO_TYPE_IPV6_TCP:
1641 		iptos = IPV6_TRAFFIC_CLASS(l3.ip6);
1642 		break;
1643 	default:
1644 		iptos = 0;	/* Keep compiler happy. */
1645 		break;
1646 	}
1647 	/* Now lets get space if we don't have some already */
1648 	if (*cmp == NULL) {
1649 new_one:
1650 		nm = tcp_lro_get_last_if_ackcmp(lc, le, inp, &n_mbuf);
1651 		if (__predict_false(nm == NULL))
1652 			goto done;
1653 		*cmp = nm;
1654 		if (n_mbuf) {
1655 			/*
1656 			 *  Link in the new cmp ack to our in-order place,
1657 			 * first set our cmp ack's next to where we are.
1658 			 */
1659 			nm->m_nextpkt = m;
1660 			(*pp) = nm;
1661 			/*
1662 			 * Set it up so mv_to is advanced to our
1663 			 * compressed ack. This way the caller can
1664 			 * advance pp to the right place.
1665 			 */
1666 			*mv_to = nm;
1667 			/*
1668 			 * Advance it here locally as well.
1669 			 */
1670 			pp = &nm->m_nextpkt;
1671 		}
1672 	} else {
1673 		/* We have one already we are working on */
1674 		nm = *cmp;
1675 		if (M_TRAILINGSPACE(nm) < sizeof(struct tcp_ackent)) {
1676 			/* We ran out of space */
1677 			inp->inp_flags2 |= INP_MBUF_L_ACKS;
1678 			goto new_one;
1679 		}
1680 	}
1681 	MPASS(M_TRAILINGSPACE(nm) >= sizeof(struct tcp_ackent));
1682 	counter_u64_add(tcp_inp_lro_compressed, 1);
1683 	le->compressed++;
1684 	/* We can add in to the one on the tail */
1685 	ack_ent = mtod(nm, struct tcp_ackent *);
1686 	idx = (nm->m_len / sizeof(struct tcp_ackent));
1687 	build_ack_entry(&ack_ent[idx], th, m, ts_ptr, iptos);
1688 
1689 	/* Bump the size of both pkt-hdr and len */
1690 	nm->m_len += sizeof(struct tcp_ackent);
1691 	nm->m_pkthdr.len += sizeof(struct tcp_ackent);
1692 compressed:
1693 	/* Advance to next mbuf before freeing. */
1694 	*pp = m->m_nextpkt;
1695 	m->m_nextpkt = NULL;
1696 	m_freem(m);
1697 	return (true);
1698 done:
1699 	counter_u64_add(tcp_uncomp_total, 1);
1700 	le->uncompressed++;
1701 	return (false);
1702 }
1703 #endif
1704 
1705 static struct lro_head *
1706 tcp_lro_rx_get_bucket(struct lro_ctrl *lc, struct mbuf *m, struct lro_parser *parser)
1707 {
1708 	u_long hash;
1709 
1710 	if (M_HASHTYPE_ISHASH(m)) {
1711 		hash = m->m_pkthdr.flowid;
1712 	} else {
1713 		for (unsigned i = hash = 0; i != LRO_RAW_ADDRESS_MAX; i++)
1714 			hash += parser->data.raw[i];
1715 	}
1716 	return (&lc->lro_hash[hash % lc->lro_hashsz]);
1717 }
1718 
1719 static int
1720 tcp_lro_rx_common(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum, bool use_hash)
1721 {
1722 	struct lro_parser pi;	/* inner address data */
1723 	struct lro_parser po;	/* outer address data */
1724 	struct lro_parser *pa;	/* current parser for TCP stream */
1725 	struct lro_entry *le;
1726 	struct lro_head *bucket;
1727 	struct tcphdr *th;
1728 	int tcp_data_len;
1729 	int tcp_opt_len;
1730 	int error;
1731 	uint16_t tcp_data_sum;
1732 
1733 #ifdef INET
1734 	/* Quickly decide if packet cannot be LRO'ed */
1735 	if (__predict_false(V_ipforwarding != 0))
1736 		return (TCP_LRO_CANNOT);
1737 #endif
1738 #ifdef INET6
1739 	/* Quickly decide if packet cannot be LRO'ed */
1740 	if (__predict_false(V_ip6_forwarding != 0))
1741 		return (TCP_LRO_CANNOT);
1742 #endif
1743 
1744 	/* We expect a contiguous header [eh, ip, tcp]. */
1745 	pa = tcp_lro_parser(m, &po, &pi, true);
1746 	if (__predict_false(pa == NULL))
1747 		return (TCP_LRO_NOT_SUPPORTED);
1748 
1749 	/* We don't expect any padding. */
1750 	error = tcp_lro_trim_mbuf_chain(m, pa);
1751 	if (__predict_false(error != 0))
1752 		return (error);
1753 
1754 #ifdef INET
1755 	switch (pa->data.lro_type) {
1756 	case LRO_TYPE_IPV4_TCP:
1757 		error = tcp_lro_rx_ipv4(lc, m, pa->ip4);
1758 		if (__predict_false(error != 0))
1759 			return (error);
1760 		break;
1761 	default:
1762 		break;
1763 	}
1764 #endif
1765 	/* If no hardware or arrival stamp on the packet add timestamp */
1766 	if ((m->m_flags & (M_TSTMP_LRO | M_TSTMP)) == 0) {
1767 		m->m_pkthdr.rcv_tstmp = bintime2ns(&lc->lro_last_queue_time);
1768 		m->m_flags |= M_TSTMP_LRO;
1769 	}
1770 
1771 	/* Get pointer to TCP header. */
1772 	th = pa->tcp;
1773 
1774 	/* Don't process SYN packets. */
1775 	if (__predict_false(th->th_flags & TH_SYN))
1776 		return (TCP_LRO_CANNOT);
1777 
1778 	/* Get total TCP header length and compute payload length. */
1779 	tcp_opt_len = (th->th_off << 2);
1780 	tcp_data_len = m->m_pkthdr.len - ((uint8_t *)th -
1781 	    (uint8_t *)m->m_data) - tcp_opt_len;
1782 	tcp_opt_len -= sizeof(*th);
1783 
1784 	/* Don't process invalid TCP headers. */
1785 	if (__predict_false(tcp_opt_len < 0 || tcp_data_len < 0))
1786 		return (TCP_LRO_CANNOT);
1787 
1788 	/* Compute TCP data only checksum. */
1789 	if (tcp_data_len == 0)
1790 		tcp_data_sum = 0;	/* no data, no checksum */
1791 	else if (__predict_false(csum != 0))
1792 		tcp_data_sum = tcp_lro_rx_csum_data(pa, ~csum);
1793 	else
1794 		tcp_data_sum = tcp_lro_rx_csum_data(pa, ~th->th_sum);
1795 
1796 	/* Save TCP info in mbuf. */
1797 	m->m_nextpkt = NULL;
1798 	m->m_pkthdr.rcvif = lc->ifp;
1799 	m->m_pkthdr.lro_tcp_d_csum = tcp_data_sum;
1800 	m->m_pkthdr.lro_tcp_d_len = tcp_data_len;
1801 	m->m_pkthdr.lro_tcp_h_off = ((uint8_t *)th - (uint8_t *)m->m_data);
1802 	m->m_pkthdr.lro_nsegs = 1;
1803 
1804 	/* Get hash bucket. */
1805 	if (!use_hash) {
1806 		bucket = &lc->lro_hash[0];
1807 	} else {
1808 		bucket = tcp_lro_rx_get_bucket(lc, m, pa);
1809 	}
1810 
1811 	/* Try to find a matching previous segment. */
1812 	LIST_FOREACH(le, bucket, hash_next) {
1813 		/* Compare addresses and ports. */
1814 		if (lro_address_compare(&po.data, &le->outer.data) == false ||
1815 		    lro_address_compare(&pi.data, &le->inner.data) == false)
1816 			continue;
1817 
1818 		/* Check if no data and old ACK. */
1819 		if (tcp_data_len == 0 &&
1820 		    SEQ_LT(ntohl(th->th_ack), ntohl(le->ack_seq))) {
1821 			m_freem(m);
1822 			return (0);
1823 		}
1824 
1825 		/* Mark "m" in the last spot. */
1826 		le->m_last_mbuf->m_nextpkt = m;
1827 		/* Now set the tail to "m". */
1828 		le->m_last_mbuf = m;
1829 		return (0);
1830 	}
1831 
1832 	/* Try to find an empty slot. */
1833 	if (LIST_EMPTY(&lc->lro_free))
1834 		return (TCP_LRO_NO_ENTRIES);
1835 
1836 	/* Start a new segment chain. */
1837 	le = LIST_FIRST(&lc->lro_free);
1838 	LIST_REMOVE(le, next);
1839 	tcp_lro_active_insert(lc, bucket, le);
1840 
1841 	/* Make sure the headers are set. */
1842 	le->inner = pi;
1843 	le->outer = po;
1844 
1845 	/* Store time this entry was allocated. */
1846 	le->alloc_time = lc->lro_last_queue_time;
1847 
1848 	tcp_set_entry_to_mbuf(lc, le, m, th);
1849 
1850 	/* Now set the tail to "m". */
1851 	le->m_last_mbuf = m;
1852 
1853 	return (0);
1854 }
1855 
1856 int
1857 tcp_lro_rx(struct lro_ctrl *lc, struct mbuf *m, uint32_t csum)
1858 {
1859 	int error;
1860 
1861 	/* get current time */
1862 	binuptime(&lc->lro_last_queue_time);
1863 
1864 	CURVNET_SET(lc->ifp->if_vnet);
1865 	error = tcp_lro_rx_common(lc, m, csum, true);
1866 	CURVNET_RESTORE();
1867 
1868 	return (error);
1869 }
1870 
1871 void
1872 tcp_lro_queue_mbuf(struct lro_ctrl *lc, struct mbuf *mb)
1873 {
1874 	/* sanity checks */
1875 	if (__predict_false(lc->ifp == NULL || lc->lro_mbuf_data == NULL ||
1876 	    lc->lro_mbuf_max == 0)) {
1877 		/* packet drop */
1878 		m_freem(mb);
1879 		return;
1880 	}
1881 
1882 	/* check if packet is not LRO capable */
1883 	if (__predict_false(mb->m_pkthdr.csum_flags == 0 ||
1884 	    (lc->ifp->if_capenable & IFCAP_LRO) == 0)) {
1885 		/* input packet to network layer */
1886 		(*lc->ifp->if_input) (lc->ifp, mb);
1887 		return;
1888 	}
1889 
1890 	/* create sequence number */
1891 	lc->lro_mbuf_data[lc->lro_mbuf_count].seq =
1892 	    (((uint64_t)M_HASHTYPE_GET(mb)) << 56) |
1893 	    (((uint64_t)mb->m_pkthdr.flowid) << 24) |
1894 	    ((uint64_t)lc->lro_mbuf_count);
1895 
1896 	/* enter mbuf */
1897 	lc->lro_mbuf_data[lc->lro_mbuf_count].mb = mb;
1898 
1899 	/* flush if array is full */
1900 	if (__predict_false(++lc->lro_mbuf_count == lc->lro_mbuf_max))
1901 		tcp_lro_flush_all(lc);
1902 }
1903 
1904 /* end */
1905