xref: /xnu-10063.141.1/bsd/skywalk/nexus/netif/nx_netif_gso.c (revision d8b80295118ef25ac3a784134bcf95cd8e88109f)
1 /*
2  * Copyright (c) 2020-2022 Apple Inc. All rights reserved.
3  *
4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5  *
6  * This file contains Original Code and/or Modifications of Original Code
7  * as defined in and that are subject to the Apple Public Source License
8  * Version 2.0 (the 'License'). You may not use this file except in
9  * compliance with the License. The rights granted to you under the License
10  * may not be used to create, or enable the creation or redistribution of,
11  * unlawful or unlicensed copies of an Apple operating system, or to
12  * circumvent, violate, or enable the circumvention or violation of, any
13  * terms of an Apple operating system software license agreement.
14  *
15  * Please obtain a copy of the License at
16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
17  *
18  * The Original Code and all software distributed under the License are
19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23  * Please see the License for the specific language governing rights and
24  * limitations under the License.
25  *
26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27  */
28 
29 /*
30  * Copyright (C) 2014, Stefano Garzarella - Universita` di Pisa.
31  * All rights reserved.
32  *
33  * Redistribution and use in source and binary forms, with or without
34  * modification, are permitted provided that the following conditions
35  * are met:
36  *   1. Redistributions of source code must retain the above copyright
37  *      notice, this list of conditions and the following disclaimer.
38  *   2. Redistributions in binary form must reproduce the above copyright
39  *      notice, this list of conditions and the following disclaimer in the
40  *      documentation and/or other materials provided with the distribution.
41  *
42  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
43  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
44  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
45  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
46  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
47  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
48  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
49  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
50  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
51  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
52  * SUCH DAMAGE.
53  */
54 
55 #include <sys/param.h>
56 #include <sys/kernel.h>
57 #include <sys/types.h>
58 #include <sys/systm.h>
59 #include <sys/mbuf.h>
60 #include <sys/socket.h>
61 #include <sys/sysctl.h>
62 #include <sys/malloc.h>
63 
64 #include <netinet/in.h>
65 #include <netinet/ip_var.h>
66 #include <netinet/ip.h>
67 #include <netinet/tcp.h>
68 #include <netinet/tcpip.h>
69 #include <netinet/ip6.h>
70 #include <netinet6/ip6_var.h>
71 
72 #include <net/if.h>
73 #include <net/if_var.h>
74 #include <net/ethernet.h>
75 #include <net/pktap.h>
76 #include <skywalk/os_skywalk_private.h>
77 #include <skywalk/nexus/netif/nx_netif.h>
78 
79 #define CSUM_GSO_MASK    0x00300000
80 #define CSUM_GSO_OFFSET  20
81 #define CSUM_TO_GSO(x) ((x & CSUM_GSO_MASK) >> CSUM_GSO_OFFSET)
82 
83 enum netif_gso_type {
84 	GSO_NONE,
85 	GSO_TCP4,
86 	GSO_TCP6,
87 	GSO_END_OF_TYPE
88 };
89 
90 uint32_t netif_chain_enqueue = 1;
91 #if (DEVELOPMENT || DEBUG)
92 SYSCTL_UINT(_kern_skywalk_netif, OID_AUTO, chain_enqueue,
93     CTLFLAG_RW | CTLFLAG_LOCKED, &netif_chain_enqueue, 0,
94     "netif chain enqueue");
95 #endif /* (DEVELOPMENT || DEBUG) */
96 
97 /*
98  * Array of function pointers that execute GSO depending on packet type
99  */
100 int (*netif_gso_functions[GSO_END_OF_TYPE]) (struct ifnet*, struct mbuf*);
101 
102 /*
103  * Structure that contains the state during the TCP segmentation
104  */
105 struct netif_gso_ip_tcp_state {
106 	void (*update)(struct netif_gso_ip_tcp_state*,
107 	    struct __kern_packet *pkt, uint8_t *baddr);
108 	void (*internal)(struct netif_gso_ip_tcp_state*, uint32_t partial,
109 	    uint16_t payload_len, uint32_t *csum_flags);
110 	union {
111 		struct ip *ip;
112 		struct ip6_hdr *ip6;
113 	} hdr;
114 	int af;
115 	struct tcphdr *tcp;
116 	struct kern_pbufpool *pp;
117 	uint32_t psuedo_hdr_csum;
118 	uint32_t tcp_seq;
119 	uint16_t hlen;
120 	uint16_t mss;
121 	uint16_t ip_id;
122 	uint8_t mac_hlen;
123 	uint8_t ip_hlen;
124 	uint8_t tcp_hlen;
125 	boolean_t copy_data_sum;
126 };
127 
128 static inline uint8_t
netif_gso_get_frame_header_len(struct mbuf * m,uint8_t * hlen)129 netif_gso_get_frame_header_len(struct mbuf *m, uint8_t *hlen)
130 {
131 	uint64_t len;
132 	char *ph = m->m_pkthdr.pkt_hdr;
133 
134 	if (__improbable(m_pktlen(m) == 0 || ph == NULL ||
135 	    ph < (char *)m->m_data)) {
136 		return ERANGE;
137 	}
138 	len = (ph - m_mtod_current(m));
139 	if (__improbable(len > UINT8_MAX)) {
140 		return ERANGE;
141 	}
142 	*hlen = (uint8_t)len;
143 	return 0;
144 }
145 
146 static inline int
netif_gso_check_netif_active(struct ifnet * ifp,struct mbuf * m,struct kern_pbufpool ** pp)147 netif_gso_check_netif_active(struct ifnet *ifp, struct mbuf *m,
148     struct kern_pbufpool **pp)
149 {
150 	struct __kern_channel_ring *kring;
151 	struct nx_netif *nif = NA(ifp)->nifna_netif;
152 	struct netif_stats *nifs = &nif->nif_stats;
153 	struct kern_nexus *nx = nif->nif_nx;
154 	struct nexus_adapter *hwna = nx_port_get_na(nx, NEXUS_PORT_NET_IF_DEV);
155 	uint32_t sc_idx = MBUF_SCIDX(m_get_service_class(m));
156 
157 	if (__improbable(!NA_IS_ACTIVE(hwna))) {
158 		STATS_INC(nifs, NETIF_STATS_DROP_NA_INACTIVE);
159 		SK_DF(SK_VERB_NETIF,
160 		    "\"%s\" (0x%llx) not in skywalk mode anymore",
161 		    hwna->na_name, SK_KVA(hwna));
162 		return ENXIO;
163 	}
164 
165 	VERIFY(sc_idx < KPKT_SC_MAX_CLASSES);
166 	kring = &hwna->na_tx_rings[hwna->na_kring_svc_lut[sc_idx]];
167 	if (__improbable(KR_DROP(kring))) {
168 		STATS_INC(nifs, NETIF_STATS_DROP_KRDROP_MODE);
169 		SK_DF(SK_VERB_NETIF,
170 		    "kr \"%s\" (0x%llx) krflags 0x%b or %s in drop mode",
171 		    kring->ckr_name, SK_KVA(kring), kring->ckr_flags,
172 		    CKRF_BITS, ifp->if_xname);
173 		return ENXIO;
174 	}
175 	*pp = kring->ckr_pp;
176 	return 0;
177 }
178 
179 static inline boolean_t
netif_chain_enqueue_enabled(struct ifnet * ifp)180 netif_chain_enqueue_enabled(struct ifnet *ifp)
181 {
182 	return netif_chain_enqueue != 0 && ifp->if_output_netem == NULL &&
183 	       (ifp->if_eflags & IFEF_ENQUEUE_MULTI) == 0;
184 }
185 
186 static inline int
netif_gso_send(struct ifnet * ifp,struct __kern_packet * head,struct __kern_packet * tail,uint32_t count,uint32_t bytes)187 netif_gso_send(struct ifnet *ifp, struct __kern_packet *head,
188     struct __kern_packet *tail, uint32_t count, uint32_t bytes)
189 {
190 	struct nx_netif *nif = NA(ifp)->nifna_netif;
191 	struct netif_stats *nifs = &nif->nif_stats;
192 	struct netif_qset *qset = NULL;
193 	uint64_t qset_id = 0;
194 	int error = 0;
195 	boolean_t dropped;
196 
197 	if (NX_LLINK_PROV(nif->nif_nx) &&
198 	    ifp->if_traffic_rule_count > 0 &&
199 	    nxctl_inet_traffic_rule_find_qset_id_with_pkt(ifp->if_xname,
200 	    head, &qset_id) == 0) {
201 		qset = nx_netif_find_qset(nif, qset_id);
202 		ASSERT(qset != NULL);
203 	}
204 	if (netif_chain_enqueue_enabled(ifp)) {
205 		dropped = false;
206 		if (qset != NULL) {
207 			head->pkt_qset_idx = qset->nqs_idx;
208 			error = ifnet_enqueue_ifcq_pkt_chain(ifp, qset->nqs_ifcq,
209 			    head, tail, count, bytes, false, &dropped);
210 		} else {
211 			error = ifnet_enqueue_pkt_chain(ifp, head, tail,
212 			    count, bytes, false, &dropped);
213 		}
214 		if (__improbable(dropped)) {
215 			STATS_ADD(nifs, NETIF_STATS_TX_DROP_ENQ_AQM, count);
216 			STATS_ADD(nifs, NETIF_STATS_DROP, count);
217 		}
218 	} else {
219 		struct __kern_packet *pkt = head, *next;
220 		uint32_t c = 0, b = 0;
221 
222 		while (pkt != NULL) {
223 			int err;
224 
225 			next = pkt->pkt_nextpkt;
226 			pkt->pkt_nextpkt = NULL;
227 			c++;
228 			b += pkt->pkt_length;
229 
230 			dropped = false;
231 			if (qset != NULL) {
232 				pkt->pkt_qset_idx = qset->nqs_idx;
233 				err = ifnet_enqueue_ifcq_pkt(ifp, qset->nqs_ifcq,
234 				    pkt, false, &dropped);
235 			} else {
236 				err = ifnet_enqueue_pkt(ifp, pkt, false, &dropped);
237 			}
238 			if (error == 0 && __improbable(err != 0)) {
239 				error = err;
240 			}
241 			if (__improbable(dropped)) {
242 				STATS_INC(nifs, NETIF_STATS_TX_DROP_ENQ_AQM);
243 				STATS_INC(nifs, NETIF_STATS_DROP);
244 			}
245 			pkt = next;
246 		}
247 		ASSERT(c == count);
248 		ASSERT(b == bytes);
249 	}
250 	if (qset != NULL) {
251 		nx_netif_qset_release(&qset);
252 	}
253 	netif_transmit(ifp, NETIF_XMIT_FLAG_HOST);
254 	return error;
255 }
256 
257 /*
258  * Segment and transmit a queue of packets which fit the given mss + hdr_len.
259  * m points to mbuf chain to be segmented.
260  * This function splits the payload (m-> m_pkthdr.len - hdr_len)
261  * into segments of length MSS bytes and then copy the first hdr_len bytes
262  * from m at the top of each segment.
263  */
264 static inline int
netif_gso_tcp_segment_mbuf(struct mbuf * m,struct ifnet * ifp,struct netif_gso_ip_tcp_state * state,struct kern_pbufpool * pp)265 netif_gso_tcp_segment_mbuf(struct mbuf *m, struct ifnet *ifp,
266     struct netif_gso_ip_tcp_state *state, struct kern_pbufpool *pp)
267 {
268 	uuid_t euuid;
269 	struct pktq pktq_alloc, pktq_seg;
270 	uint64_t timestamp = 0;
271 	uint64_t pflags;
272 	int error = 0;
273 	uint32_t policy_id;
274 	uint32_t skip_policy_id;
275 	uint32_t svc_class;
276 	uint32_t n, n_pkts, n_bytes;
277 	int32_t off = 0, total_len = m->m_pkthdr.len;
278 	uint8_t tx_headroom = (uint8_t)ifp->if_tx_headroom;
279 	struct netif_stats *nifs = &NA(ifp)->nifna_netif->nif_stats;
280 	struct __kern_packet *pkt_chain_head, *pkt_chain_tail;
281 	uint16_t mss = state->mss;
282 	bool skip_pktap;
283 
284 	VERIFY(total_len > state->hlen);
285 	VERIFY(((tx_headroom + state->mac_hlen) & 0x1) == 0);
286 	VERIFY((tx_headroom + state->hlen + mss) <= PP_BUF_SIZE_DEF(pp));
287 
288 	KPKTQ_INIT(&pktq_alloc);
289 	KPKTQ_INIT(&pktq_seg);
290 	/* batch allocate enough packets */
291 	n_pkts = (uint32_t)(SK_ROUNDUP((total_len - state->hlen), mss) / mss);
292 	error = pp_alloc_pktq(pp, 1, &pktq_alloc, n_pkts, NULL,
293 	    NULL, SKMEM_NOSLEEP);
294 	if (__improbable(error != 0)) {
295 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NOMEM);
296 		SK_ERR("failed to alloc %u pkts", n_pkts);
297 		pp_free_pktq(&pktq_alloc);
298 		error = ENOBUFS;
299 		goto done;
300 	}
301 
302 	ASSERT(m->m_pkthdr.pkt_proto == IPPROTO_TCP);
303 	ASSERT((m->m_flags & M_BCAST) == 0);
304 	ASSERT((m->m_flags & M_MCAST) == 0);
305 	ASSERT(((m->m_pkthdr.pkt_flags & PKTF_TX_COMPL_TS_REQ) == 0));
306 	pflags = m->m_pkthdr.pkt_flags & PKT_F_COMMON_MASK;
307 	pflags |= PKTF_START_SEQ;
308 	(void) mbuf_get_timestamp(m, &timestamp, NULL);
309 	necp_get_app_uuid_from_packet(m, euuid);
310 	policy_id = necp_get_policy_id_from_packet(m);
311 	skip_policy_id = necp_get_skip_policy_id_from_packet(m);
312 	svc_class = m_get_service_class(m);
313 	skip_pktap = (m->m_pkthdr.pkt_flags & PKTF_SKIP_PKTAP) != 0 ||
314 	    pktap_total_tap_count == 0;
315 
316 	for (n = 1, off = state->hlen; off < total_len; off += mss, n++) {
317 		uint8_t *baddr, *baddr0;
318 		uint32_t partial = 0;
319 		struct __kern_packet *pkt;
320 
321 		KPKTQ_DEQUEUE(&pktq_alloc, pkt);
322 		ASSERT(pkt != NULL);
323 
324 		/* get buffer address from packet */
325 		MD_BUFLET_ADDR_ABS(pkt, baddr0);
326 		baddr = baddr0;
327 		baddr += tx_headroom;
328 
329 		/*
330 		 * Copy the link-layer, IP and TCP header from the
331 		 * original packet.
332 		 */
333 		m_copydata(m, 0, state->hlen, baddr);
334 		baddr += state->hlen;
335 
336 		/*
337 		 * Copy the payload from original packet and
338 		 * compute partial checksum on the payload.
339 		 */
340 		if (off + mss > total_len) {
341 			/* if last segment is less than mss */
342 			mss = (uint16_t)(total_len - off);
343 		}
344 		if (state->copy_data_sum) {
345 			partial = m_copydata_sum(m, off, mss, baddr, 0, NULL);
346 		} else {
347 			m_copydata(m, off, mss, baddr);
348 		}
349 
350 		/*
351 		 * update packet metadata
352 		 */
353 		pkt->pkt_headroom = tx_headroom;
354 		pkt->pkt_l2_len = state->mac_hlen;
355 		pkt->pkt_link_flags = 0;
356 		pkt->pkt_csum_flags = 0;
357 		pkt->pkt_csum_tx_start_off = 0;
358 		pkt->pkt_csum_tx_stuff_off = 0;
359 		uuid_copy(pkt->pkt_policy_euuid, euuid);
360 		pkt->pkt_policy_id = policy_id;
361 		pkt->pkt_skip_policy_id = skip_policy_id;
362 		pkt->pkt_timestamp = timestamp;
363 		pkt->pkt_svc_class = svc_class;
364 		pkt->pkt_pflags |= pflags;
365 		pkt->pkt_flowsrc_type = m->m_pkthdr.pkt_flowsrc;
366 		pkt->pkt_flow_token = m->m_pkthdr.pkt_flowid;
367 		pkt->pkt_comp_gencnt = m->m_pkthdr.comp_gencnt;
368 		pkt->pkt_flow_ip_proto = IPPROTO_TCP;
369 		pkt->pkt_transport_protocol = IPPROTO_TCP;
370 		pkt->pkt_flow_tcp_seq = htonl(state->tcp_seq);
371 
372 		state->update(state, pkt, baddr0);
373 		/*
374 		 * FIN or PUSH flags if present will be set only on the last
375 		 * segment.
376 		 */
377 		if (n != n_pkts) {
378 			state->tcp->th_flags &= ~(TH_FIN | TH_PUSH);
379 		}
380 		/*
381 		 * CWR flag if present is set only on the first segment
382 		 * and cleared on the subsequent segments.
383 		 */
384 		if (n != 1) {
385 			state->tcp->th_flags &= ~TH_CWR;
386 			state->tcp->th_seq = htonl(state->tcp_seq);
387 		}
388 		ASSERT(state->tcp->th_seq == pkt->pkt_flow_tcp_seq);
389 		state->internal(state, partial, mss, &pkt->pkt_csum_flags);
390 		METADATA_ADJUST_LEN(pkt, state->hlen + mss, tx_headroom);
391 		VERIFY(__packet_finalize(SK_PKT2PH(pkt)) == 0);
392 		KPKTQ_ENQUEUE(&pktq_seg, pkt);
393 		if (!skip_pktap) {
394 			nx_netif_pktap_output(ifp, state->af, pkt);
395 		}
396 	}
397 	ASSERT(off == total_len);
398 	STATS_ADD(nifs, NETIF_STATS_GSO_SEG, n_pkts);
399 
400 	/* ifnet_enqueue_pkt_chain() consumes the packet chain */
401 	pkt_chain_head = KPKTQ_FIRST(&pktq_seg);
402 	pkt_chain_tail = KPKTQ_LAST(&pktq_seg);
403 	KPKTQ_INIT(&pktq_seg);
404 	n_bytes = total_len + (state->hlen * (n_pkts - 1));
405 
406 	error = netif_gso_send(ifp, pkt_chain_head, pkt_chain_tail,
407 	    n_pkts, n_bytes);
408 
409 done:
410 	KPKTQ_FINI(&pktq_alloc);
411 	return error;
412 }
413 
414 /*
415  * Update the pointers to TCP and IPv4 headers
416  */
417 static void
netif_gso_ipv4_tcp_update(struct netif_gso_ip_tcp_state * state,struct __kern_packet * pkt,uint8_t * baddr)418 netif_gso_ipv4_tcp_update(struct netif_gso_ip_tcp_state *state,
419     struct __kern_packet *pkt, uint8_t *baddr)
420 {
421 	state->hdr.ip = (struct ip *)(void *)(baddr + pkt->pkt_headroom +
422 	    pkt->pkt_l2_len);
423 	state->tcp = (struct tcphdr *)(void *)((caddr_t)(state->hdr.ip) +
424 	    state->ip_hlen);
425 }
426 
427 /*
428  * Finalize the TCP and IPv4 headers
429  */
430 static void
netif_gso_ipv4_tcp_internal(struct netif_gso_ip_tcp_state * state,uint32_t partial,uint16_t payload_len,uint32_t * csum_flags __unused)431 netif_gso_ipv4_tcp_internal(struct netif_gso_ip_tcp_state *state,
432     uint32_t partial, uint16_t payload_len, uint32_t *csum_flags __unused)
433 {
434 	/*
435 	 * Update IP header
436 	 */
437 	state->hdr.ip->ip_id = htons((state->ip_id)++);
438 	state->hdr.ip->ip_len = htons(state->ip_hlen + state->tcp_hlen +
439 	    payload_len);
440 	/*
441 	 * IP header checksum
442 	 */
443 	state->hdr.ip->ip_sum = 0;
444 	state->hdr.ip->ip_sum = inet_cksum_buffer(state->hdr.ip, 0, 0,
445 	    state->ip_hlen);
446 	/*
447 	 * TCP Checksum
448 	 */
449 	state->tcp->th_sum = 0;
450 	partial = __packet_cksum(state->tcp, state->tcp_hlen, partial);
451 	partial += htons(state->tcp_hlen + IPPROTO_TCP + payload_len);
452 	partial += state->psuedo_hdr_csum;
453 	ADDCARRY(partial);
454 	state->tcp->th_sum = ~(uint16_t)partial;
455 	/*
456 	 * Update tcp sequence number in gso state
457 	 */
458 	state->tcp_seq += payload_len;
459 }
460 
461 static void
netif_gso_ipv4_tcp_internal_nosum(struct netif_gso_ip_tcp_state * state,uint32_t partial __unused,uint16_t payload_len __unused,uint32_t * csum_flags)462 netif_gso_ipv4_tcp_internal_nosum(struct netif_gso_ip_tcp_state *state,
463     uint32_t partial __unused, uint16_t payload_len __unused,
464     uint32_t *csum_flags)
465 {
466 	/*
467 	 * Update IP header
468 	 */
469 	state->hdr.ip->ip_id = htons((state->ip_id)++);
470 	state->hdr.ip->ip_len = htons(state->ip_hlen + state->tcp_hlen +
471 	    payload_len);
472 	/*
473 	 * Update tcp sequence number in gso state
474 	 */
475 	state->tcp_seq += payload_len;
476 
477 	/* offload csum to hardware */
478 	*csum_flags |= PACKET_CSUM_IP | PACKET_CSUM_TCP;
479 }
480 
481 /*
482  * Updates the pointers to TCP and IPv6 headers
483  */
484 static void
netif_gso_ipv6_tcp_update(struct netif_gso_ip_tcp_state * state,struct __kern_packet * pkt,uint8_t * baddr)485 netif_gso_ipv6_tcp_update(struct netif_gso_ip_tcp_state *state,
486     struct __kern_packet *pkt, uint8_t *baddr)
487 {
488 	state->hdr.ip6 = (struct ip6_hdr *)(baddr + pkt->pkt_headroom +
489 	    pkt->pkt_l2_len);
490 	state->tcp = (struct tcphdr *)(void *)((caddr_t)(state->hdr.ip6) +
491 	    state->ip_hlen);
492 }
493 
494 /*
495  * Finalize the TCP and IPv6 headers
496  */
497 static void
netif_gso_ipv6_tcp_internal_nosum(struct netif_gso_ip_tcp_state * state,uint32_t partial __unused,uint16_t payload_len __unused,uint32_t * csum_flags)498 netif_gso_ipv6_tcp_internal_nosum(struct netif_gso_ip_tcp_state *state,
499     uint32_t partial __unused, uint16_t payload_len __unused,
500     uint32_t *csum_flags)
501 {
502 	/*
503 	 * Update IP header
504 	 */
505 	state->hdr.ip6->ip6_plen = htons(state->tcp_hlen + payload_len);
506 
507 	/*
508 	 * Update tcp sequence number
509 	 */
510 	state->tcp_seq += payload_len;
511 
512 	/* offload csum to hardware */
513 	*csum_flags |= PACKET_CSUM_TCPIPV6;
514 }
515 
516 /*
517  * Finalize the TCP and IPv6 headers
518  */
519 static void
netif_gso_ipv6_tcp_internal(struct netif_gso_ip_tcp_state * state,uint32_t partial,uint16_t payload_len,uint32_t * csum_flags __unused)520 netif_gso_ipv6_tcp_internal(struct netif_gso_ip_tcp_state *state,
521     uint32_t partial, uint16_t payload_len, uint32_t *csum_flags __unused)
522 {
523 	/*
524 	 * Update IP header
525 	 */
526 	state->hdr.ip6->ip6_plen = htons(state->tcp_hlen + payload_len);
527 	/*
528 	 * TCP Checksum
529 	 */
530 	state->tcp->th_sum = 0;
531 	partial = __packet_cksum(state->tcp, state->tcp_hlen, partial);
532 	partial += htonl(state->tcp_hlen + IPPROTO_TCP + payload_len);
533 	partial += state->psuedo_hdr_csum;
534 	ADDCARRY(partial);
535 	state->tcp->th_sum = ~(uint16_t)partial;
536 	/*
537 	 * Update tcp sequence number
538 	 */
539 	state->tcp_seq += payload_len;
540 }
541 
542 /*
543  * Init the state during the TCP segmentation
544  */
545 static inline void
netif_gso_ip_tcp_init_state(struct netif_gso_ip_tcp_state * state,struct mbuf * m,uint8_t mac_hlen,uint8_t ip_hlen,bool isipv6,ifnet_t ifp)546 netif_gso_ip_tcp_init_state(struct netif_gso_ip_tcp_state *state,
547     struct mbuf *m, uint8_t mac_hlen, uint8_t ip_hlen, bool isipv6, ifnet_t ifp)
548 {
549 	if (isipv6) {
550 		state->af = AF_INET6;
551 		state->hdr.ip6 = (struct ip6_hdr *)(mtod(m, uint8_t *) +
552 		    mac_hlen);
553 		/* should be atleast 16 bit aligned */
554 		VERIFY(((uintptr_t)state->hdr.ip6 & (uintptr_t)0x1) == 0);
555 		state->tcp = (struct tcphdr *)(void *)((caddr_t)
556 		    (state->hdr.ip6) + ip_hlen);
557 		state->update = netif_gso_ipv6_tcp_update;
558 		if (ifp->if_hwassist & IFNET_CSUM_TCPIPV6) {
559 			state->internal = netif_gso_ipv6_tcp_internal_nosum;
560 			state->copy_data_sum = false;
561 		} else {
562 			state->internal = netif_gso_ipv6_tcp_internal;
563 			state->copy_data_sum = true;
564 		}
565 		state->psuedo_hdr_csum = in6_pseudo(&state->hdr.ip6->ip6_src,
566 		    &state->hdr.ip6->ip6_dst, 0);
567 	} else {
568 		struct in_addr ip_src, ip_dst;
569 
570 		state->af = AF_INET;
571 		state->hdr.ip = (struct ip *)(void *)(mtod(m, uint8_t *) +
572 		    mac_hlen);
573 		/* should be atleast 16 bit aligned */
574 		VERIFY(((uintptr_t)state->hdr.ip & (uintptr_t)0x1) == 0);
575 		state->ip_id = ntohs(state->hdr.ip->ip_id);
576 		state->tcp = (struct tcphdr *)(void *)((caddr_t)
577 		    (state->hdr.ip) + ip_hlen);
578 		state->update = netif_gso_ipv4_tcp_update;
579 		if ((ifp->if_hwassist & (IFNET_CSUM_IP | IFNET_CSUM_TCP)) ==
580 		    (IFNET_CSUM_IP | IFNET_CSUM_TCP)) {
581 			state->internal = netif_gso_ipv4_tcp_internal_nosum;
582 			state->copy_data_sum = false;
583 		} else {
584 			state->internal = netif_gso_ipv4_tcp_internal;
585 			state->copy_data_sum = true;
586 		}
587 		bcopy(&state->hdr.ip->ip_src, &ip_src, sizeof(ip_src));
588 		bcopy(&state->hdr.ip->ip_dst, &ip_dst, sizeof(ip_dst));
589 		state->psuedo_hdr_csum = in_pseudo(ip_src.s_addr,
590 		    ip_dst.s_addr, 0);
591 	}
592 
593 	state->mac_hlen = mac_hlen;
594 	state->ip_hlen = ip_hlen;
595 	state->tcp_hlen = (uint8_t)(state->tcp->th_off << 2);
596 	state->hlen = mac_hlen + ip_hlen + state->tcp_hlen;
597 	VERIFY(m->m_pkthdr.tso_segsz != 0);
598 	state->mss = (uint16_t)m->m_pkthdr.tso_segsz;
599 	state->tcp_seq = ntohl(state->tcp->th_seq);
600 }
601 
602 /*
603  * GSO on TCP/IPv4
604  */
605 static int
netif_gso_ipv4_tcp(struct ifnet * ifp,struct mbuf * m)606 netif_gso_ipv4_tcp(struct ifnet *ifp, struct mbuf *m)
607 {
608 	struct ip *ip;
609 	struct kern_pbufpool *pp = NULL;
610 	struct netif_gso_ip_tcp_state state;
611 	uint16_t hlen;
612 	uint8_t ip_hlen;
613 	uint8_t mac_hlen;
614 	struct netif_stats *nifs = &NA(ifp)->nifna_netif->nif_stats;
615 	boolean_t pkt_dropped = false;
616 	int error;
617 
618 	STATS_INC(nifs, NETIF_STATS_GSO_PKT);
619 	if (__improbable(m->m_pkthdr.pkt_proto != IPPROTO_TCP)) {
620 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NONTCP);
621 		error = ENOTSUP;
622 		pkt_dropped = true;
623 		goto done;
624 	}
625 
626 	error = netif_gso_check_netif_active(ifp, m, &pp);
627 	if (__improbable(error != 0)) {
628 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NA_INACTIVE);
629 		error = ENXIO;
630 		pkt_dropped = true;
631 		goto done;
632 	}
633 
634 	error = netif_gso_get_frame_header_len(m, &mac_hlen);
635 	if (__improbable(error != 0)) {
636 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_BADLEN);
637 		pkt_dropped = true;
638 		goto done;
639 	}
640 
641 	hlen = mac_hlen + sizeof(struct ip);
642 	if (__improbable(m->m_len < hlen)) {
643 		m = m_pullup(m, hlen);
644 		if (m == NULL) {
645 			STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NOMEM);
646 			error = ENOBUFS;
647 			pkt_dropped = true;
648 			goto done;
649 		}
650 	}
651 	ip = (struct ip *)(void *)(mtod(m, uint8_t *) + mac_hlen);
652 	ip_hlen = (uint8_t)(ip->ip_hl << 2);
653 	hlen = mac_hlen + ip_hlen + sizeof(struct tcphdr);
654 	if (__improbable(m->m_len < hlen)) {
655 		m = m_pullup(m, hlen);
656 		if (m == NULL) {
657 			STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NOMEM);
658 			error = ENOBUFS;
659 			pkt_dropped = true;
660 			goto done;
661 		}
662 	}
663 	netif_gso_ip_tcp_init_state(&state, m, mac_hlen, ip_hlen, false, ifp);
664 	error = netif_gso_tcp_segment_mbuf(m, ifp, &state, pp);
665 done:
666 	m_freem(m);
667 	if (__improbable(pkt_dropped)) {
668 		STATS_INC(nifs, NETIF_STATS_DROP);
669 	}
670 	return error;
671 }
672 
673 /*
674  * GSO on TCP/IPv6
675  */
676 static int
netif_gso_ipv6_tcp(struct ifnet * ifp,struct mbuf * m)677 netif_gso_ipv6_tcp(struct ifnet *ifp, struct mbuf *m)
678 {
679 	struct ip6_hdr *ip6;
680 	struct kern_pbufpool *pp = NULL;
681 	struct netif_gso_ip_tcp_state state;
682 	int lasthdr_off;
683 	uint16_t hlen;
684 	uint8_t ip_hlen;
685 	uint8_t mac_hlen;
686 	struct netif_stats *nifs = &NA(ifp)->nifna_netif->nif_stats;
687 	boolean_t pkt_dropped = false;
688 	int error;
689 
690 	STATS_INC(nifs, NETIF_STATS_GSO_PKT);
691 	if (__improbable(m->m_pkthdr.pkt_proto != IPPROTO_TCP)) {
692 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NONTCP);
693 		error = ENOTSUP;
694 		pkt_dropped = true;
695 		goto done;
696 	}
697 
698 	error = netif_gso_check_netif_active(ifp, m, &pp);
699 	if (__improbable(error != 0)) {
700 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NA_INACTIVE);
701 		error = ENXIO;
702 		pkt_dropped = true;
703 		goto done;
704 	}
705 
706 	error = netif_gso_get_frame_header_len(m, &mac_hlen);
707 	if (__improbable(error != 0)) {
708 		STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_BADLEN);
709 		pkt_dropped = true;
710 		goto done;
711 	}
712 
713 	hlen = mac_hlen + sizeof(struct ip6_hdr);
714 	if (__improbable(m->m_len < hlen)) {
715 		m = m_pullup(m, hlen);
716 		if (m == NULL) {
717 			STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NOMEM);
718 			error = ENOBUFS;
719 			pkt_dropped = true;
720 			goto done;
721 		}
722 	}
723 	ip6 = (struct ip6_hdr *)(mtod(m, uint8_t *) + mac_hlen);
724 	lasthdr_off = ip6_lasthdr(m, mac_hlen, IPPROTO_IPV6, NULL) - mac_hlen;
725 	VERIFY(lasthdr_off <= UINT8_MAX);
726 	ip_hlen = (uint8_t)lasthdr_off;
727 	hlen = mac_hlen + ip_hlen + sizeof(struct tcphdr);
728 	if (__improbable(m->m_len < hlen)) {
729 		m = m_pullup(m, hlen);
730 		if (m == NULL) {
731 			STATS_INC(nifs, NETIF_STATS_GSO_PKT_DROP_NOMEM);
732 			error = ENOBUFS;
733 			pkt_dropped = true;
734 			goto done;
735 		}
736 	}
737 	netif_gso_ip_tcp_init_state(&state, m, mac_hlen, ip_hlen, true, ifp);
738 	error = netif_gso_tcp_segment_mbuf(m, ifp, &state, pp);
739 done:
740 	m_freem(m);
741 	if (__improbable(pkt_dropped)) {
742 		STATS_INC(nifs, NETIF_STATS_DROP);
743 	}
744 	return error;
745 }
746 
747 int
netif_gso_dispatch(struct ifnet * ifp,struct mbuf * m)748 netif_gso_dispatch(struct ifnet *ifp, struct mbuf *m)
749 {
750 	int gso_flags;
751 
752 	ASSERT(m->m_nextpkt == NULL);
753 	gso_flags = CSUM_TO_GSO(m->m_pkthdr.csum_flags);
754 	VERIFY(gso_flags < GSO_END_OF_TYPE);
755 	return netif_gso_functions[gso_flags](ifp, m);
756 }
757 
758 void
netif_gso_init(void)759 netif_gso_init(void)
760 {
761 	_CASSERT(CSUM_TO_GSO(~(CSUM_TSO_IPV4 | CSUM_TSO_IPV6)) == GSO_NONE);
762 	_CASSERT(CSUM_TO_GSO(CSUM_TSO_IPV4) == GSO_TCP4);
763 	_CASSERT(CSUM_TO_GSO(CSUM_TSO_IPV6) == GSO_TCP6);
764 	netif_gso_functions[GSO_NONE] = nx_netif_host_output;
765 	netif_gso_functions[GSO_TCP4] = netif_gso_ipv4_tcp;
766 	netif_gso_functions[GSO_TCP6] = netif_gso_ipv6_tcp;
767 }
768 
769 void
netif_gso_fini(void)770 netif_gso_fini(void)
771 {
772 	netif_gso_functions[GSO_NONE] = NULL;
773 	netif_gso_functions[GSO_TCP4] = NULL;
774 	netif_gso_functions[GSO_TCP6] = NULL;
775 }
776