xref: /openbmc/linux/net/openvswitch/flow.c (revision 9aa2cba7)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2007-2014 Nicira, Inc.
4  */
5 
6 #include <linux/uaccess.h>
7 #include <linux/netdevice.h>
8 #include <linux/etherdevice.h>
9 #include <linux/if_ether.h>
10 #include <linux/if_vlan.h>
11 #include <net/llc_pdu.h>
12 #include <linux/kernel.h>
13 #include <linux/jhash.h>
14 #include <linux/jiffies.h>
15 #include <linux/llc.h>
16 #include <linux/module.h>
17 #include <linux/in.h>
18 #include <linux/rcupdate.h>
19 #include <linux/cpumask.h>
20 #include <linux/if_arp.h>
21 #include <linux/ip.h>
22 #include <linux/ipv6.h>
23 #include <linux/mpls.h>
24 #include <linux/sctp.h>
25 #include <linux/smp.h>
26 #include <linux/tcp.h>
27 #include <linux/udp.h>
28 #include <linux/icmp.h>
29 #include <linux/icmpv6.h>
30 #include <linux/rculist.h>
31 #include <net/ip.h>
32 #include <net/ip_tunnels.h>
33 #include <net/ipv6.h>
34 #include <net/mpls.h>
35 #include <net/ndisc.h>
36 #include <net/nsh.h>
37 #include <net/pkt_cls.h>
38 #include <net/netfilter/nf_conntrack_zones.h>
39 
40 #include "conntrack.h"
41 #include "datapath.h"
42 #include "flow.h"
43 #include "flow_netlink.h"
44 #include "vport.h"
45 
46 u64 ovs_flow_used_time(unsigned long flow_jiffies)
47 {
48 	struct timespec64 cur_ts;
49 	u64 cur_ms, idle_ms;
50 
51 	ktime_get_ts64(&cur_ts);
52 	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
53 	cur_ms = (u64)(u32)cur_ts.tv_sec * MSEC_PER_SEC +
54 		 cur_ts.tv_nsec / NSEC_PER_MSEC;
55 
56 	return cur_ms - idle_ms;
57 }
58 
59 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))
60 
61 void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags,
62 			   const struct sk_buff *skb)
63 {
64 	struct sw_flow_stats *stats;
65 	unsigned int cpu = smp_processor_id();
66 	int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
67 
68 	stats = rcu_dereference(flow->stats[cpu]);
69 
70 	/* Check if already have CPU-specific stats. */
71 	if (likely(stats)) {
72 		spin_lock(&stats->lock);
73 		/* Mark if we write on the pre-allocated stats. */
74 		if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
75 			flow->stats_last_writer = cpu;
76 	} else {
77 		stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
78 		spin_lock(&stats->lock);
79 
80 		/* If the current CPU is the only writer on the
81 		 * pre-allocated stats keep using them.
82 		 */
83 		if (unlikely(flow->stats_last_writer != cpu)) {
84 			/* A previous locker may have already allocated the
85 			 * stats, so we need to check again.  If CPU-specific
86 			 * stats were already allocated, we update the pre-
87 			 * allocated stats as we have already locked them.
88 			 */
89 			if (likely(flow->stats_last_writer != -1) &&
90 			    likely(!rcu_access_pointer(flow->stats[cpu]))) {
91 				/* Try to allocate CPU-specific stats. */
92 				struct sw_flow_stats *new_stats;
93 
94 				new_stats =
95 					kmem_cache_alloc_node(flow_stats_cache,
96 							      GFP_NOWAIT |
97 							      __GFP_THISNODE |
98 							      __GFP_NOWARN |
99 							      __GFP_NOMEMALLOC,
100 							      numa_node_id());
101 				if (likely(new_stats)) {
102 					new_stats->used = jiffies;
103 					new_stats->packet_count = 1;
104 					new_stats->byte_count = len;
105 					new_stats->tcp_flags = tcp_flags;
106 					spin_lock_init(&new_stats->lock);
107 
108 					rcu_assign_pointer(flow->stats[cpu],
109 							   new_stats);
110 					cpumask_set_cpu(cpu,
111 							flow->cpu_used_mask);
112 					goto unlock;
113 				}
114 			}
115 			flow->stats_last_writer = cpu;
116 		}
117 	}
118 
119 	stats->used = jiffies;
120 	stats->packet_count++;
121 	stats->byte_count += len;
122 	stats->tcp_flags |= tcp_flags;
123 unlock:
124 	spin_unlock(&stats->lock);
125 }
126 
127 /* Must be called with rcu_read_lock or ovs_mutex. */
128 void ovs_flow_stats_get(const struct sw_flow *flow,
129 			struct ovs_flow_stats *ovs_stats,
130 			unsigned long *used, __be16 *tcp_flags)
131 {
132 	int cpu;
133 
134 	*used = 0;
135 	*tcp_flags = 0;
136 	memset(ovs_stats, 0, sizeof(*ovs_stats));
137 
138 	/* We open code this to make sure cpu 0 is always considered */
139 	for (cpu = 0; cpu < nr_cpu_ids;
140 	     cpu = cpumask_next(cpu, flow->cpu_used_mask)) {
141 		struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);
142 
143 		if (stats) {
144 			/* Local CPU may write on non-local stats, so we must
145 			 * block bottom-halves here.
146 			 */
147 			spin_lock_bh(&stats->lock);
148 			if (!*used || time_after(stats->used, *used))
149 				*used = stats->used;
150 			*tcp_flags |= stats->tcp_flags;
151 			ovs_stats->n_packets += stats->packet_count;
152 			ovs_stats->n_bytes += stats->byte_count;
153 			spin_unlock_bh(&stats->lock);
154 		}
155 	}
156 }
157 
158 /* Called with ovs_mutex. */
159 void ovs_flow_stats_clear(struct sw_flow *flow)
160 {
161 	int cpu;
162 
163 	/* We open code this to make sure cpu 0 is always considered */
164 	for (cpu = 0; cpu < nr_cpu_ids;
165 	     cpu = cpumask_next(cpu, flow->cpu_used_mask)) {
166 		struct sw_flow_stats *stats = ovsl_dereference(flow->stats[cpu]);
167 
168 		if (stats) {
169 			spin_lock_bh(&stats->lock);
170 			stats->used = 0;
171 			stats->packet_count = 0;
172 			stats->byte_count = 0;
173 			stats->tcp_flags = 0;
174 			spin_unlock_bh(&stats->lock);
175 		}
176 	}
177 }
178 
179 static int check_header(struct sk_buff *skb, int len)
180 {
181 	if (unlikely(skb->len < len))
182 		return -EINVAL;
183 	if (unlikely(!pskb_may_pull(skb, len)))
184 		return -ENOMEM;
185 	return 0;
186 }
187 
188 static bool arphdr_ok(struct sk_buff *skb)
189 {
190 	return pskb_may_pull(skb, skb_network_offset(skb) +
191 				  sizeof(struct arp_eth_header));
192 }
193 
194 static int check_iphdr(struct sk_buff *skb)
195 {
196 	unsigned int nh_ofs = skb_network_offset(skb);
197 	unsigned int ip_len;
198 	int err;
199 
200 	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
201 	if (unlikely(err))
202 		return err;
203 
204 	ip_len = ip_hdrlen(skb);
205 	if (unlikely(ip_len < sizeof(struct iphdr) ||
206 		     skb->len < nh_ofs + ip_len))
207 		return -EINVAL;
208 
209 	skb_set_transport_header(skb, nh_ofs + ip_len);
210 	return 0;
211 }
212 
213 static bool tcphdr_ok(struct sk_buff *skb)
214 {
215 	int th_ofs = skb_transport_offset(skb);
216 	int tcp_len;
217 
218 	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
219 		return false;
220 
221 	tcp_len = tcp_hdrlen(skb);
222 	if (unlikely(tcp_len < sizeof(struct tcphdr) ||
223 		     skb->len < th_ofs + tcp_len))
224 		return false;
225 
226 	return true;
227 }
228 
229 static bool udphdr_ok(struct sk_buff *skb)
230 {
231 	return pskb_may_pull(skb, skb_transport_offset(skb) +
232 				  sizeof(struct udphdr));
233 }
234 
235 static bool sctphdr_ok(struct sk_buff *skb)
236 {
237 	return pskb_may_pull(skb, skb_transport_offset(skb) +
238 				  sizeof(struct sctphdr));
239 }
240 
241 static bool icmphdr_ok(struct sk_buff *skb)
242 {
243 	return pskb_may_pull(skb, skb_transport_offset(skb) +
244 				  sizeof(struct icmphdr));
245 }
246 
247 /**
248  * get_ipv6_ext_hdrs() - Parses packet and sets IPv6 extension header flags.
249  *
250  * @skb: buffer where extension header data starts in packet
251  * @nh: ipv6 header
252  * @ext_hdrs: flags are stored here
253  *
254  * OFPIEH12_UNREP is set if more than one of a given IPv6 extension header
255  * is unexpectedly encountered. (Two destination options headers may be
256  * expected and would not cause this bit to be set.)
257  *
258  * OFPIEH12_UNSEQ is set if IPv6 extension headers were not in the order
259  * preferred (but not required) by RFC 2460:
260  *
261  * When more than one extension header is used in the same packet, it is
262  * recommended that those headers appear in the following order:
263  *      IPv6 header
264  *      Hop-by-Hop Options header
265  *      Destination Options header
266  *      Routing header
267  *      Fragment header
268  *      Authentication header
269  *      Encapsulating Security Payload header
270  *      Destination Options header
271  *      upper-layer header
272  */
273 static void get_ipv6_ext_hdrs(struct sk_buff *skb, struct ipv6hdr *nh,
274 			      u16 *ext_hdrs)
275 {
276 	u8 next_type = nh->nexthdr;
277 	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
278 	int dest_options_header_count = 0;
279 
280 	*ext_hdrs = 0;
281 
282 	while (ipv6_ext_hdr(next_type)) {
283 		struct ipv6_opt_hdr _hdr, *hp;
284 
285 		switch (next_type) {
286 		case IPPROTO_NONE:
287 			*ext_hdrs |= OFPIEH12_NONEXT;
288 			/* stop parsing */
289 			return;
290 
291 		case IPPROTO_ESP:
292 			if (*ext_hdrs & OFPIEH12_ESP)
293 				*ext_hdrs |= OFPIEH12_UNREP;
294 			if ((*ext_hdrs & ~(OFPIEH12_HOP | OFPIEH12_DEST |
295 					   OFPIEH12_ROUTER | IPPROTO_FRAGMENT |
296 					   OFPIEH12_AUTH | OFPIEH12_UNREP)) ||
297 			    dest_options_header_count >= 2) {
298 				*ext_hdrs |= OFPIEH12_UNSEQ;
299 			}
300 			*ext_hdrs |= OFPIEH12_ESP;
301 			break;
302 
303 		case IPPROTO_AH:
304 			if (*ext_hdrs & OFPIEH12_AUTH)
305 				*ext_hdrs |= OFPIEH12_UNREP;
306 			if ((*ext_hdrs &
307 			     ~(OFPIEH12_HOP | OFPIEH12_DEST | OFPIEH12_ROUTER |
308 			       IPPROTO_FRAGMENT | OFPIEH12_UNREP)) ||
309 			    dest_options_header_count >= 2) {
310 				*ext_hdrs |= OFPIEH12_UNSEQ;
311 			}
312 			*ext_hdrs |= OFPIEH12_AUTH;
313 			break;
314 
315 		case IPPROTO_DSTOPTS:
316 			if (dest_options_header_count == 0) {
317 				if (*ext_hdrs &
318 				    ~(OFPIEH12_HOP | OFPIEH12_UNREP))
319 					*ext_hdrs |= OFPIEH12_UNSEQ;
320 				*ext_hdrs |= OFPIEH12_DEST;
321 			} else if (dest_options_header_count == 1) {
322 				if (*ext_hdrs &
323 				    ~(OFPIEH12_HOP | OFPIEH12_DEST |
324 				      OFPIEH12_ROUTER | OFPIEH12_FRAG |
325 				      OFPIEH12_AUTH | OFPIEH12_ESP |
326 				      OFPIEH12_UNREP)) {
327 					*ext_hdrs |= OFPIEH12_UNSEQ;
328 				}
329 			} else {
330 				*ext_hdrs |= OFPIEH12_UNREP;
331 			}
332 			dest_options_header_count++;
333 			break;
334 
335 		case IPPROTO_FRAGMENT:
336 			if (*ext_hdrs & OFPIEH12_FRAG)
337 				*ext_hdrs |= OFPIEH12_UNREP;
338 			if ((*ext_hdrs & ~(OFPIEH12_HOP |
339 					   OFPIEH12_DEST |
340 					   OFPIEH12_ROUTER |
341 					   OFPIEH12_UNREP)) ||
342 			    dest_options_header_count >= 2) {
343 				*ext_hdrs |= OFPIEH12_UNSEQ;
344 			}
345 			*ext_hdrs |= OFPIEH12_FRAG;
346 			break;
347 
348 		case IPPROTO_ROUTING:
349 			if (*ext_hdrs & OFPIEH12_ROUTER)
350 				*ext_hdrs |= OFPIEH12_UNREP;
351 			if ((*ext_hdrs & ~(OFPIEH12_HOP |
352 					   OFPIEH12_DEST |
353 					   OFPIEH12_UNREP)) ||
354 			    dest_options_header_count >= 2) {
355 				*ext_hdrs |= OFPIEH12_UNSEQ;
356 			}
357 			*ext_hdrs |= OFPIEH12_ROUTER;
358 			break;
359 
360 		case IPPROTO_HOPOPTS:
361 			if (*ext_hdrs & OFPIEH12_HOP)
362 				*ext_hdrs |= OFPIEH12_UNREP;
363 			/* OFPIEH12_HOP is set to 1 if a hop-by-hop IPv6
364 			 * extension header is present as the first
365 			 * extension header in the packet.
366 			 */
367 			if (*ext_hdrs == 0)
368 				*ext_hdrs |= OFPIEH12_HOP;
369 			else
370 				*ext_hdrs |= OFPIEH12_UNSEQ;
371 			break;
372 
373 		default:
374 			return;
375 		}
376 
377 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
378 		if (!hp)
379 			break;
380 		next_type = hp->nexthdr;
381 		start += ipv6_optlen(hp);
382 	}
383 }
384 
385 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
386 {
387 	unsigned short frag_off;
388 	unsigned int payload_ofs = 0;
389 	unsigned int nh_ofs = skb_network_offset(skb);
390 	unsigned int nh_len;
391 	struct ipv6hdr *nh;
392 	int err, nexthdr, flags = 0;
393 
394 	err = check_header(skb, nh_ofs + sizeof(*nh));
395 	if (unlikely(err))
396 		return err;
397 
398 	nh = ipv6_hdr(skb);
399 
400 	get_ipv6_ext_hdrs(skb, nh, &key->ipv6.exthdrs);
401 
402 	key->ip.proto = NEXTHDR_NONE;
403 	key->ip.tos = ipv6_get_dsfield(nh);
404 	key->ip.ttl = nh->hop_limit;
405 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
406 	key->ipv6.addr.src = nh->saddr;
407 	key->ipv6.addr.dst = nh->daddr;
408 
409 	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
410 	if (flags & IP6_FH_F_FRAG) {
411 		if (frag_off) {
412 			key->ip.frag = OVS_FRAG_TYPE_LATER;
413 			key->ip.proto = NEXTHDR_FRAGMENT;
414 			return 0;
415 		}
416 		key->ip.frag = OVS_FRAG_TYPE_FIRST;
417 	} else {
418 		key->ip.frag = OVS_FRAG_TYPE_NONE;
419 	}
420 
421 	/* Delayed handling of error in ipv6_find_hdr() as it
422 	 * always sets flags and frag_off to a valid value which may be
423 	 * used to set key->ip.frag above.
424 	 */
425 	if (unlikely(nexthdr < 0))
426 		return -EPROTO;
427 
428 	nh_len = payload_ofs - nh_ofs;
429 	skb_set_transport_header(skb, nh_ofs + nh_len);
430 	key->ip.proto = nexthdr;
431 	return nh_len;
432 }
433 
434 static bool icmp6hdr_ok(struct sk_buff *skb)
435 {
436 	return pskb_may_pull(skb, skb_transport_offset(skb) +
437 				  sizeof(struct icmp6hdr));
438 }
439 
440 /**
441  * parse_vlan_tag - Parse vlan tag from vlan header.
442  * @skb: skb containing frame to parse
443  * @key_vh: pointer to parsed vlan tag
444  * @untag_vlan: should the vlan header be removed from the frame
445  *
446  * Return: ERROR on memory error.
447  * %0 if it encounters a non-vlan or incomplete packet.
448  * %1 after successfully parsing vlan tag.
449  */
450 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
451 			  bool untag_vlan)
452 {
453 	struct vlan_head *vh = (struct vlan_head *)skb->data;
454 
455 	if (likely(!eth_type_vlan(vh->tpid)))
456 		return 0;
457 
458 	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
459 		return 0;
460 
461 	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
462 				 sizeof(__be16))))
463 		return -ENOMEM;
464 
465 	vh = (struct vlan_head *)skb->data;
466 	key_vh->tci = vh->tci | htons(VLAN_CFI_MASK);
467 	key_vh->tpid = vh->tpid;
468 
469 	if (unlikely(untag_vlan)) {
470 		int offset = skb->data - skb_mac_header(skb);
471 		u16 tci;
472 		int err;
473 
474 		__skb_push(skb, offset);
475 		err = __skb_vlan_pop(skb, &tci);
476 		__skb_pull(skb, offset);
477 		if (err)
478 			return err;
479 		__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
480 	} else {
481 		__skb_pull(skb, sizeof(struct vlan_head));
482 	}
483 	return 1;
484 }
485 
486 static void clear_vlan(struct sw_flow_key *key)
487 {
488 	key->eth.vlan.tci = 0;
489 	key->eth.vlan.tpid = 0;
490 	key->eth.cvlan.tci = 0;
491 	key->eth.cvlan.tpid = 0;
492 }
493 
494 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
495 {
496 	int res;
497 
498 	if (skb_vlan_tag_present(skb)) {
499 		key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK);
500 		key->eth.vlan.tpid = skb->vlan_proto;
501 	} else {
502 		/* Parse outer vlan tag in the non-accelerated case. */
503 		res = parse_vlan_tag(skb, &key->eth.vlan, true);
504 		if (res <= 0)
505 			return res;
506 	}
507 
508 	/* Parse inner vlan tag. */
509 	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
510 	if (res <= 0)
511 		return res;
512 
513 	return 0;
514 }
515 
516 static __be16 parse_ethertype(struct sk_buff *skb)
517 {
518 	struct llc_snap_hdr {
519 		u8  dsap;  /* Always 0xAA */
520 		u8  ssap;  /* Always 0xAA */
521 		u8  ctrl;
522 		u8  oui[3];
523 		__be16 ethertype;
524 	};
525 	struct llc_snap_hdr *llc;
526 	__be16 proto;
527 
528 	proto = *(__be16 *) skb->data;
529 	__skb_pull(skb, sizeof(__be16));
530 
531 	if (eth_proto_is_802_3(proto))
532 		return proto;
533 
534 	if (skb->len < sizeof(struct llc_snap_hdr))
535 		return htons(ETH_P_802_2);
536 
537 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
538 		return htons(0);
539 
540 	llc = (struct llc_snap_hdr *) skb->data;
541 	if (llc->dsap != LLC_SAP_SNAP ||
542 	    llc->ssap != LLC_SAP_SNAP ||
543 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
544 		return htons(ETH_P_802_2);
545 
546 	__skb_pull(skb, sizeof(struct llc_snap_hdr));
547 
548 	if (eth_proto_is_802_3(llc->ethertype))
549 		return llc->ethertype;
550 
551 	return htons(ETH_P_802_2);
552 }
553 
554 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
555 			int nh_len)
556 {
557 	struct icmp6hdr *icmp = icmp6_hdr(skb);
558 
559 	/* The ICMPv6 type and code fields use the 16-bit transport port
560 	 * fields, so we need to store them in 16-bit network byte order.
561 	 */
562 	key->tp.src = htons(icmp->icmp6_type);
563 	key->tp.dst = htons(icmp->icmp6_code);
564 	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));
565 
566 	if (icmp->icmp6_code == 0 &&
567 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
568 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
569 		int icmp_len = skb->len - skb_transport_offset(skb);
570 		struct nd_msg *nd;
571 		int offset;
572 
573 		/* In order to process neighbor discovery options, we need the
574 		 * entire packet.
575 		 */
576 		if (unlikely(icmp_len < sizeof(*nd)))
577 			return 0;
578 
579 		if (unlikely(skb_linearize(skb)))
580 			return -ENOMEM;
581 
582 		nd = (struct nd_msg *)skb_transport_header(skb);
583 		key->ipv6.nd.target = nd->target;
584 
585 		icmp_len -= sizeof(*nd);
586 		offset = 0;
587 		while (icmp_len >= 8) {
588 			struct nd_opt_hdr *nd_opt =
589 				 (struct nd_opt_hdr *)(nd->opt + offset);
590 			int opt_len = nd_opt->nd_opt_len * 8;
591 
592 			if (unlikely(!opt_len || opt_len > icmp_len))
593 				return 0;
594 
595 			/* Store the link layer address if the appropriate
596 			 * option is provided.  It is considered an error if
597 			 * the same link layer option is specified twice.
598 			 */
599 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
600 			    && opt_len == 8) {
601 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
602 					goto invalid;
603 				ether_addr_copy(key->ipv6.nd.sll,
604 						&nd->opt[offset+sizeof(*nd_opt)]);
605 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
606 				   && opt_len == 8) {
607 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
608 					goto invalid;
609 				ether_addr_copy(key->ipv6.nd.tll,
610 						&nd->opt[offset+sizeof(*nd_opt)]);
611 			}
612 
613 			icmp_len -= opt_len;
614 			offset += opt_len;
615 		}
616 	}
617 
618 	return 0;
619 
620 invalid:
621 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
622 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
623 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
624 
625 	return 0;
626 }
627 
628 static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
629 {
630 	struct nshhdr *nh;
631 	unsigned int nh_ofs = skb_network_offset(skb);
632 	u8 version, length;
633 	int err;
634 
635 	err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
636 	if (unlikely(err))
637 		return err;
638 
639 	nh = nsh_hdr(skb);
640 	version = nsh_get_ver(nh);
641 	length = nsh_hdr_len(nh);
642 
643 	if (version != 0)
644 		return -EINVAL;
645 
646 	err = check_header(skb, nh_ofs + length);
647 	if (unlikely(err))
648 		return err;
649 
650 	nh = nsh_hdr(skb);
651 	key->nsh.base.flags = nsh_get_flags(nh);
652 	key->nsh.base.ttl = nsh_get_ttl(nh);
653 	key->nsh.base.mdtype = nh->mdtype;
654 	key->nsh.base.np = nh->np;
655 	key->nsh.base.path_hdr = nh->path_hdr;
656 	switch (key->nsh.base.mdtype) {
657 	case NSH_M_TYPE1:
658 		if (length != NSH_M_TYPE1_LEN)
659 			return -EINVAL;
660 		memcpy(key->nsh.context, nh->md1.context,
661 		       sizeof(nh->md1));
662 		break;
663 	case NSH_M_TYPE2:
664 		memset(key->nsh.context, 0,
665 		       sizeof(nh->md1));
666 		break;
667 	default:
668 		return -EINVAL;
669 	}
670 
671 	return 0;
672 }
673 
674 /**
675  * key_extract_l3l4 - extracts L3/L4 header information.
676  * @skb: sk_buff that contains the frame, with skb->data pointing to the
677  *       L3 header
678  * @key: output flow key
679  *
680  * Return: %0 if successful, otherwise a negative errno value.
681  */
682 static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
683 {
684 	int error;
685 
686 	/* Network layer. */
687 	if (key->eth.type == htons(ETH_P_IP)) {
688 		struct iphdr *nh;
689 		__be16 offset;
690 
691 		error = check_iphdr(skb);
692 		if (unlikely(error)) {
693 			memset(&key->ip, 0, sizeof(key->ip));
694 			memset(&key->ipv4, 0, sizeof(key->ipv4));
695 			if (error == -EINVAL) {
696 				skb->transport_header = skb->network_header;
697 				error = 0;
698 			}
699 			return error;
700 		}
701 
702 		nh = ip_hdr(skb);
703 		key->ipv4.addr.src = nh->saddr;
704 		key->ipv4.addr.dst = nh->daddr;
705 
706 		key->ip.proto = nh->protocol;
707 		key->ip.tos = nh->tos;
708 		key->ip.ttl = nh->ttl;
709 
710 		offset = nh->frag_off & htons(IP_OFFSET);
711 		if (offset) {
712 			key->ip.frag = OVS_FRAG_TYPE_LATER;
713 			memset(&key->tp, 0, sizeof(key->tp));
714 			return 0;
715 		}
716 		if (nh->frag_off & htons(IP_MF) ||
717 			skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
718 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
719 		else
720 			key->ip.frag = OVS_FRAG_TYPE_NONE;
721 
722 		/* Transport layer. */
723 		if (key->ip.proto == IPPROTO_TCP) {
724 			if (tcphdr_ok(skb)) {
725 				struct tcphdr *tcp = tcp_hdr(skb);
726 				key->tp.src = tcp->source;
727 				key->tp.dst = tcp->dest;
728 				key->tp.flags = TCP_FLAGS_BE16(tcp);
729 			} else {
730 				memset(&key->tp, 0, sizeof(key->tp));
731 			}
732 
733 		} else if (key->ip.proto == IPPROTO_UDP) {
734 			if (udphdr_ok(skb)) {
735 				struct udphdr *udp = udp_hdr(skb);
736 				key->tp.src = udp->source;
737 				key->tp.dst = udp->dest;
738 			} else {
739 				memset(&key->tp, 0, sizeof(key->tp));
740 			}
741 		} else if (key->ip.proto == IPPROTO_SCTP) {
742 			if (sctphdr_ok(skb)) {
743 				struct sctphdr *sctp = sctp_hdr(skb);
744 				key->tp.src = sctp->source;
745 				key->tp.dst = sctp->dest;
746 			} else {
747 				memset(&key->tp, 0, sizeof(key->tp));
748 			}
749 		} else if (key->ip.proto == IPPROTO_ICMP) {
750 			if (icmphdr_ok(skb)) {
751 				struct icmphdr *icmp = icmp_hdr(skb);
752 				/* The ICMP type and code fields use the 16-bit
753 				 * transport port fields, so we need to store
754 				 * them in 16-bit network byte order. */
755 				key->tp.src = htons(icmp->type);
756 				key->tp.dst = htons(icmp->code);
757 			} else {
758 				memset(&key->tp, 0, sizeof(key->tp));
759 			}
760 		}
761 
762 	} else if (key->eth.type == htons(ETH_P_ARP) ||
763 		   key->eth.type == htons(ETH_P_RARP)) {
764 		struct arp_eth_header *arp;
765 		bool arp_available = arphdr_ok(skb);
766 
767 		arp = (struct arp_eth_header *)skb_network_header(skb);
768 
769 		if (arp_available &&
770 		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
771 		    arp->ar_pro == htons(ETH_P_IP) &&
772 		    arp->ar_hln == ETH_ALEN &&
773 		    arp->ar_pln == 4) {
774 
775 			/* We only match on the lower 8 bits of the opcode. */
776 			if (ntohs(arp->ar_op) <= 0xff)
777 				key->ip.proto = ntohs(arp->ar_op);
778 			else
779 				key->ip.proto = 0;
780 
781 			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
782 			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
783 			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
784 			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
785 		} else {
786 			memset(&key->ip, 0, sizeof(key->ip));
787 			memset(&key->ipv4, 0, sizeof(key->ipv4));
788 		}
789 	} else if (eth_p_mpls(key->eth.type)) {
790 		u8 label_count = 1;
791 
792 		memset(&key->mpls, 0, sizeof(key->mpls));
793 		skb_set_inner_network_header(skb, skb->mac_len);
794 		while (1) {
795 			__be32 lse;
796 
797 			error = check_header(skb, skb->mac_len +
798 					     label_count * MPLS_HLEN);
799 			if (unlikely(error))
800 				return 0;
801 
802 			memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
803 
804 			if (label_count <= MPLS_LABEL_DEPTH)
805 				memcpy(&key->mpls.lse[label_count - 1], &lse,
806 				       MPLS_HLEN);
807 
808 			skb_set_inner_network_header(skb, skb->mac_len +
809 						     label_count * MPLS_HLEN);
810 			if (lse & htonl(MPLS_LS_S_MASK))
811 				break;
812 
813 			label_count++;
814 		}
815 		if (label_count > MPLS_LABEL_DEPTH)
816 			label_count = MPLS_LABEL_DEPTH;
817 
818 		key->mpls.num_labels_mask = GENMASK(label_count - 1, 0);
819 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
820 		int nh_len;             /* IPv6 Header + Extensions */
821 
822 		nh_len = parse_ipv6hdr(skb, key);
823 		if (unlikely(nh_len < 0)) {
824 			switch (nh_len) {
825 			case -EINVAL:
826 				memset(&key->ip, 0, sizeof(key->ip));
827 				memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
828 				fallthrough;
829 			case -EPROTO:
830 				skb->transport_header = skb->network_header;
831 				error = 0;
832 				break;
833 			default:
834 				error = nh_len;
835 			}
836 			return error;
837 		}
838 
839 		if (key->ip.frag == OVS_FRAG_TYPE_LATER) {
840 			memset(&key->tp, 0, sizeof(key->tp));
841 			return 0;
842 		}
843 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
844 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
845 
846 		/* Transport layer. */
847 		if (key->ip.proto == NEXTHDR_TCP) {
848 			if (tcphdr_ok(skb)) {
849 				struct tcphdr *tcp = tcp_hdr(skb);
850 				key->tp.src = tcp->source;
851 				key->tp.dst = tcp->dest;
852 				key->tp.flags = TCP_FLAGS_BE16(tcp);
853 			} else {
854 				memset(&key->tp, 0, sizeof(key->tp));
855 			}
856 		} else if (key->ip.proto == NEXTHDR_UDP) {
857 			if (udphdr_ok(skb)) {
858 				struct udphdr *udp = udp_hdr(skb);
859 				key->tp.src = udp->source;
860 				key->tp.dst = udp->dest;
861 			} else {
862 				memset(&key->tp, 0, sizeof(key->tp));
863 			}
864 		} else if (key->ip.proto == NEXTHDR_SCTP) {
865 			if (sctphdr_ok(skb)) {
866 				struct sctphdr *sctp = sctp_hdr(skb);
867 				key->tp.src = sctp->source;
868 				key->tp.dst = sctp->dest;
869 			} else {
870 				memset(&key->tp, 0, sizeof(key->tp));
871 			}
872 		} else if (key->ip.proto == NEXTHDR_ICMP) {
873 			if (icmp6hdr_ok(skb)) {
874 				error = parse_icmpv6(skb, key, nh_len);
875 				if (error)
876 					return error;
877 			} else {
878 				memset(&key->tp, 0, sizeof(key->tp));
879 			}
880 		}
881 	} else if (key->eth.type == htons(ETH_P_NSH)) {
882 		error = parse_nsh(skb, key);
883 		if (error)
884 			return error;
885 	}
886 	return 0;
887 }
888 
889 /**
890  * key_extract - extracts a flow key from an Ethernet frame.
891  * @skb: sk_buff that contains the frame, with skb->data pointing to the
892  * Ethernet header
893  * @key: output flow key
894  *
895  * The caller must ensure that skb->len >= ETH_HLEN.
896  *
897  * Initializes @skb header fields as follows:
898  *
899  *    - skb->mac_header: the L2 header.
900  *
901  *    - skb->network_header: just past the L2 header, or just past the
902  *      VLAN header, to the first byte of the L2 payload.
903  *
904  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
905  *      on output, then just past the IP header, if one is present and
906  *      of a correct length, otherwise the same as skb->network_header.
907  *      For other key->eth.type values it is left untouched.
908  *
909  *    - skb->protocol: the type of the data starting at skb->network_header.
910  *      Equals to key->eth.type.
911  *
912  * Return: %0 if successful, otherwise a negative errno value.
913  */
914 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
915 {
916 	struct ethhdr *eth;
917 
918 	/* Flags are always used as part of stats */
919 	key->tp.flags = 0;
920 
921 	skb_reset_mac_header(skb);
922 
923 	/* Link layer. */
924 	clear_vlan(key);
925 	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
926 		if (unlikely(eth_type_vlan(skb->protocol)))
927 			return -EINVAL;
928 
929 		skb_reset_network_header(skb);
930 		key->eth.type = skb->protocol;
931 	} else {
932 		eth = eth_hdr(skb);
933 		ether_addr_copy(key->eth.src, eth->h_source);
934 		ether_addr_copy(key->eth.dst, eth->h_dest);
935 
936 		__skb_pull(skb, 2 * ETH_ALEN);
937 		/* We are going to push all headers that we pull, so no need to
938 		 * update skb->csum here.
939 		 */
940 
941 		if (unlikely(parse_vlan(skb, key)))
942 			return -ENOMEM;
943 
944 		key->eth.type = parse_ethertype(skb);
945 		if (unlikely(key->eth.type == htons(0)))
946 			return -ENOMEM;
947 
948 		/* Multiple tagged packets need to retain TPID to satisfy
949 		 * skb_vlan_pop(), which will later shift the ethertype into
950 		 * skb->protocol.
951 		 */
952 		if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK))
953 			skb->protocol = key->eth.cvlan.tpid;
954 		else
955 			skb->protocol = key->eth.type;
956 
957 		skb_reset_network_header(skb);
958 		__skb_push(skb, skb->data - skb_mac_header(skb));
959 	}
960 
961 	skb_reset_mac_len(skb);
962 
963 	/* Fill out L3/L4 key info, if any */
964 	return key_extract_l3l4(skb, key);
965 }
966 
967 /* In the case of conntrack fragment handling it expects L3 headers,
968  * add a helper.
969  */
970 int ovs_flow_key_update_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
971 {
972 	return key_extract_l3l4(skb, key);
973 }
974 
975 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
976 {
977 	int res;
978 
979 	res = key_extract(skb, key);
980 	if (!res)
981 		key->mac_proto &= ~SW_FLOW_KEY_INVALID;
982 
983 	return res;
984 }
985 
986 static int key_extract_mac_proto(struct sk_buff *skb)
987 {
988 	switch (skb->dev->type) {
989 	case ARPHRD_ETHER:
990 		return MAC_PROTO_ETHERNET;
991 	case ARPHRD_NONE:
992 		if (skb->protocol == htons(ETH_P_TEB))
993 			return MAC_PROTO_ETHERNET;
994 		return MAC_PROTO_NONE;
995 	}
996 	WARN_ON_ONCE(1);
997 	return -EINVAL;
998 }
999 
1000 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
1001 			 struct sk_buff *skb, struct sw_flow_key *key)
1002 {
1003 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1004 	struct tc_skb_ext *tc_ext;
1005 #endif
1006 	bool post_ct = false, post_ct_snat = false, post_ct_dnat = false;
1007 	int res, err;
1008 	u16 zone = 0;
1009 
1010 	/* Extract metadata from packet. */
1011 	if (tun_info) {
1012 		key->tun_proto = ip_tunnel_info_af(tun_info);
1013 		memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
1014 
1015 		if (tun_info->options_len) {
1016 			BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
1017 						   8)) - 1
1018 					> sizeof(key->tun_opts));
1019 
1020 			ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
1021 						tun_info);
1022 			key->tun_opts_len = tun_info->options_len;
1023 		} else {
1024 			key->tun_opts_len = 0;
1025 		}
1026 	} else  {
1027 		key->tun_proto = 0;
1028 		key->tun_opts_len = 0;
1029 		memset(&key->tun_key, 0, sizeof(key->tun_key));
1030 	}
1031 
1032 	key->phy.priority = skb->priority;
1033 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
1034 	key->phy.skb_mark = skb->mark;
1035 	key->ovs_flow_hash = 0;
1036 	res = key_extract_mac_proto(skb);
1037 	if (res < 0)
1038 		return res;
1039 	key->mac_proto = res;
1040 
1041 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1042 	if (tc_skb_ext_tc_enabled()) {
1043 		tc_ext = skb_ext_find(skb, TC_SKB_EXT);
1044 		key->recirc_id = tc_ext && !tc_ext->act_miss ?
1045 				 tc_ext->chain : 0;
1046 		OVS_CB(skb)->mru = tc_ext ? tc_ext->mru : 0;
1047 		post_ct = tc_ext ? tc_ext->post_ct : false;
1048 		post_ct_snat = post_ct ? tc_ext->post_ct_snat : false;
1049 		post_ct_dnat = post_ct ? tc_ext->post_ct_dnat : false;
1050 		zone = post_ct ? tc_ext->zone : 0;
1051 	} else {
1052 		key->recirc_id = 0;
1053 	}
1054 #else
1055 	key->recirc_id = 0;
1056 #endif
1057 
1058 	err = key_extract(skb, key);
1059 	if (!err) {
1060 		ovs_ct_fill_key(skb, key, post_ct);   /* Must be after key_extract(). */
1061 		if (post_ct) {
1062 			if (!skb_get_nfct(skb)) {
1063 				key->ct_zone = zone;
1064 			} else {
1065 				if (!post_ct_dnat)
1066 					key->ct_state &= ~OVS_CS_F_DST_NAT;
1067 				if (!post_ct_snat)
1068 					key->ct_state &= ~OVS_CS_F_SRC_NAT;
1069 			}
1070 		}
1071 	}
1072 	return err;
1073 }
1074 
1075 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
1076 				   struct sk_buff *skb,
1077 				   struct sw_flow_key *key, bool log)
1078 {
1079 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
1080 	u64 attrs = 0;
1081 	int err;
1082 
1083 	err = parse_flow_nlattrs(attr, a, &attrs, log);
1084 	if (err)
1085 		return -EINVAL;
1086 
1087 	/* Extract metadata from netlink attributes. */
1088 	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
1089 	if (err)
1090 		return err;
1091 
1092 	/* key_extract assumes that skb->protocol is set-up for
1093 	 * layer 3 packets which is the case for other callers,
1094 	 * in particular packets received from the network stack.
1095 	 * Here the correct value can be set from the metadata
1096 	 * extracted above.
1097 	 * For L2 packet key eth type would be zero. skb protocol
1098 	 * would be set to correct value later during key-extact.
1099 	 */
1100 
1101 	skb->protocol = key->eth.type;
1102 	err = key_extract(skb, key);
1103 	if (err)
1104 		return err;
1105 
1106 	/* Check that we have conntrack original direction tuple metadata only
1107 	 * for packets for which it makes sense.  Otherwise the key may be
1108 	 * corrupted due to overlapping key fields.
1109 	 */
1110 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
1111 	    key->eth.type != htons(ETH_P_IP))
1112 		return -EINVAL;
1113 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
1114 	    (key->eth.type != htons(ETH_P_IPV6) ||
1115 	     sw_flow_key_is_nd(key)))
1116 		return -EINVAL;
1117 
1118 	return 0;
1119 }
1120