xref: /linux/net/openvswitch/flow.c (revision 5c35a02c545a7bbe77f3a1ae337d9e29beed079b)
1 /*
2  * Copyright (c) 2007-2014 Nicira, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program; if not, write to the Free Software
15  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
16  * 02110-1301, USA
17  */
18 
19 #include <linux/uaccess.h>
20 #include <linux/netdevice.h>
21 #include <linux/etherdevice.h>
22 #include <linux/if_ether.h>
23 #include <linux/if_vlan.h>
24 #include <net/llc_pdu.h>
25 #include <linux/kernel.h>
26 #include <linux/jhash.h>
27 #include <linux/jiffies.h>
28 #include <linux/llc.h>
29 #include <linux/module.h>
30 #include <linux/in.h>
31 #include <linux/rcupdate.h>
32 #include <linux/cpumask.h>
33 #include <linux/if_arp.h>
34 #include <linux/ip.h>
35 #include <linux/ipv6.h>
36 #include <linux/mpls.h>
37 #include <linux/sctp.h>
38 #include <linux/smp.h>
39 #include <linux/tcp.h>
40 #include <linux/udp.h>
41 #include <linux/icmp.h>
42 #include <linux/icmpv6.h>
43 #include <linux/rculist.h>
44 #include <net/ip.h>
45 #include <net/ip_tunnels.h>
46 #include <net/ipv6.h>
47 #include <net/mpls.h>
48 #include <net/ndisc.h>
49 #include <net/nsh.h>
50 
51 #include "conntrack.h"
52 #include "datapath.h"
53 #include "flow.h"
54 #include "flow_netlink.h"
55 #include "vport.h"
56 
57 u64 ovs_flow_used_time(unsigned long flow_jiffies)
58 {
59 	struct timespec64 cur_ts;
60 	u64 cur_ms, idle_ms;
61 
62 	ktime_get_ts64(&cur_ts);
63 	idle_ms = jiffies_to_msecs(jiffies - flow_jiffies);
64 	cur_ms = (u64)(u32)cur_ts.tv_sec * MSEC_PER_SEC +
65 		 cur_ts.tv_nsec / NSEC_PER_MSEC;
66 
67 	return cur_ms - idle_ms;
68 }
69 
70 #define TCP_FLAGS_BE16(tp) (*(__be16 *)&tcp_flag_word(tp) & htons(0x0FFF))
71 
72 void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags,
73 			   const struct sk_buff *skb)
74 {
75 	struct flow_stats *stats;
76 	unsigned int cpu = smp_processor_id();
77 	int len = skb->len + (skb_vlan_tag_present(skb) ? VLAN_HLEN : 0);
78 
79 	stats = rcu_dereference(flow->stats[cpu]);
80 
81 	/* Check if already have CPU-specific stats. */
82 	if (likely(stats)) {
83 		spin_lock(&stats->lock);
84 		/* Mark if we write on the pre-allocated stats. */
85 		if (cpu == 0 && unlikely(flow->stats_last_writer != cpu))
86 			flow->stats_last_writer = cpu;
87 	} else {
88 		stats = rcu_dereference(flow->stats[0]); /* Pre-allocated. */
89 		spin_lock(&stats->lock);
90 
91 		/* If the current CPU is the only writer on the
92 		 * pre-allocated stats keep using them.
93 		 */
94 		if (unlikely(flow->stats_last_writer != cpu)) {
95 			/* A previous locker may have already allocated the
96 			 * stats, so we need to check again.  If CPU-specific
97 			 * stats were already allocated, we update the pre-
98 			 * allocated stats as we have already locked them.
99 			 */
100 			if (likely(flow->stats_last_writer != -1) &&
101 			    likely(!rcu_access_pointer(flow->stats[cpu]))) {
102 				/* Try to allocate CPU-specific stats. */
103 				struct flow_stats *new_stats;
104 
105 				new_stats =
106 					kmem_cache_alloc_node(flow_stats_cache,
107 							      GFP_NOWAIT |
108 							      __GFP_THISNODE |
109 							      __GFP_NOWARN |
110 							      __GFP_NOMEMALLOC,
111 							      numa_node_id());
112 				if (likely(new_stats)) {
113 					new_stats->used = jiffies;
114 					new_stats->packet_count = 1;
115 					new_stats->byte_count = len;
116 					new_stats->tcp_flags = tcp_flags;
117 					spin_lock_init(&new_stats->lock);
118 
119 					rcu_assign_pointer(flow->stats[cpu],
120 							   new_stats);
121 					cpumask_set_cpu(cpu, &flow->cpu_used_mask);
122 					goto unlock;
123 				}
124 			}
125 			flow->stats_last_writer = cpu;
126 		}
127 	}
128 
129 	stats->used = jiffies;
130 	stats->packet_count++;
131 	stats->byte_count += len;
132 	stats->tcp_flags |= tcp_flags;
133 unlock:
134 	spin_unlock(&stats->lock);
135 }
136 
137 /* Must be called with rcu_read_lock or ovs_mutex. */
138 void ovs_flow_stats_get(const struct sw_flow *flow,
139 			struct ovs_flow_stats *ovs_stats,
140 			unsigned long *used, __be16 *tcp_flags)
141 {
142 	int cpu;
143 
144 	*used = 0;
145 	*tcp_flags = 0;
146 	memset(ovs_stats, 0, sizeof(*ovs_stats));
147 
148 	/* We open code this to make sure cpu 0 is always considered */
149 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
150 		struct flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);
151 
152 		if (stats) {
153 			/* Local CPU may write on non-local stats, so we must
154 			 * block bottom-halves here.
155 			 */
156 			spin_lock_bh(&stats->lock);
157 			if (!*used || time_after(stats->used, *used))
158 				*used = stats->used;
159 			*tcp_flags |= stats->tcp_flags;
160 			ovs_stats->n_packets += stats->packet_count;
161 			ovs_stats->n_bytes += stats->byte_count;
162 			spin_unlock_bh(&stats->lock);
163 		}
164 	}
165 }
166 
167 /* Called with ovs_mutex. */
168 void ovs_flow_stats_clear(struct sw_flow *flow)
169 {
170 	int cpu;
171 
172 	/* We open code this to make sure cpu 0 is always considered */
173 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
174 		struct flow_stats *stats = ovsl_dereference(flow->stats[cpu]);
175 
176 		if (stats) {
177 			spin_lock_bh(&stats->lock);
178 			stats->used = 0;
179 			stats->packet_count = 0;
180 			stats->byte_count = 0;
181 			stats->tcp_flags = 0;
182 			spin_unlock_bh(&stats->lock);
183 		}
184 	}
185 }
186 
187 static int check_header(struct sk_buff *skb, int len)
188 {
189 	if (unlikely(skb->len < len))
190 		return -EINVAL;
191 	if (unlikely(!pskb_may_pull(skb, len)))
192 		return -ENOMEM;
193 	return 0;
194 }
195 
196 static bool arphdr_ok(struct sk_buff *skb)
197 {
198 	return pskb_may_pull(skb, skb_network_offset(skb) +
199 				  sizeof(struct arp_eth_header));
200 }
201 
202 static int check_iphdr(struct sk_buff *skb)
203 {
204 	unsigned int nh_ofs = skb_network_offset(skb);
205 	unsigned int ip_len;
206 	int err;
207 
208 	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
209 	if (unlikely(err))
210 		return err;
211 
212 	ip_len = ip_hdrlen(skb);
213 	if (unlikely(ip_len < sizeof(struct iphdr) ||
214 		     skb->len < nh_ofs + ip_len))
215 		return -EINVAL;
216 
217 	skb_set_transport_header(skb, nh_ofs + ip_len);
218 	return 0;
219 }
220 
221 static bool tcphdr_ok(struct sk_buff *skb)
222 {
223 	int th_ofs = skb_transport_offset(skb);
224 	int tcp_len;
225 
226 	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
227 		return false;
228 
229 	tcp_len = tcp_hdrlen(skb);
230 	if (unlikely(tcp_len < sizeof(struct tcphdr) ||
231 		     skb->len < th_ofs + tcp_len))
232 		return false;
233 
234 	return true;
235 }
236 
237 static bool udphdr_ok(struct sk_buff *skb)
238 {
239 	return pskb_may_pull(skb, skb_transport_offset(skb) +
240 				  sizeof(struct udphdr));
241 }
242 
243 static bool sctphdr_ok(struct sk_buff *skb)
244 {
245 	return pskb_may_pull(skb, skb_transport_offset(skb) +
246 				  sizeof(struct sctphdr));
247 }
248 
249 static bool icmphdr_ok(struct sk_buff *skb)
250 {
251 	return pskb_may_pull(skb, skb_transport_offset(skb) +
252 				  sizeof(struct icmphdr));
253 }
254 
255 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
256 {
257 	unsigned int nh_ofs = skb_network_offset(skb);
258 	unsigned int nh_len;
259 	int payload_ofs;
260 	struct ipv6hdr *nh;
261 	uint8_t nexthdr;
262 	__be16 frag_off;
263 	int err;
264 
265 	err = check_header(skb, nh_ofs + sizeof(*nh));
266 	if (unlikely(err))
267 		return err;
268 
269 	nh = ipv6_hdr(skb);
270 	nexthdr = nh->nexthdr;
271 	payload_ofs = (u8 *)(nh + 1) - skb->data;
272 
273 	key->ip.proto = NEXTHDR_NONE;
274 	key->ip.tos = ipv6_get_dsfield(nh);
275 	key->ip.ttl = nh->hop_limit;
276 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
277 	key->ipv6.addr.src = nh->saddr;
278 	key->ipv6.addr.dst = nh->daddr;
279 
280 	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
281 
282 	if (frag_off) {
283 		if (frag_off & htons(~0x7))
284 			key->ip.frag = OVS_FRAG_TYPE_LATER;
285 		else
286 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
287 	} else {
288 		key->ip.frag = OVS_FRAG_TYPE_NONE;
289 	}
290 
291 	/* Delayed handling of error in ipv6_skip_exthdr() as it
292 	 * always sets frag_off to a valid value which may be
293 	 * used to set key->ip.frag above.
294 	 */
295 	if (unlikely(payload_ofs < 0))
296 		return -EPROTO;
297 
298 	nh_len = payload_ofs - nh_ofs;
299 	skb_set_transport_header(skb, nh_ofs + nh_len);
300 	key->ip.proto = nexthdr;
301 	return nh_len;
302 }
303 
304 static bool icmp6hdr_ok(struct sk_buff *skb)
305 {
306 	return pskb_may_pull(skb, skb_transport_offset(skb) +
307 				  sizeof(struct icmp6hdr));
308 }
309 
310 /**
311  * Parse vlan tag from vlan header.
312  * Returns ERROR on memory error.
313  * Returns 0 if it encounters a non-vlan or incomplete packet.
314  * Returns 1 after successfully parsing vlan tag.
315  */
316 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
317 			  bool untag_vlan)
318 {
319 	struct vlan_head *vh = (struct vlan_head *)skb->data;
320 
321 	if (likely(!eth_type_vlan(vh->tpid)))
322 		return 0;
323 
324 	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
325 		return 0;
326 
327 	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
328 				 sizeof(__be16))))
329 		return -ENOMEM;
330 
331 	vh = (struct vlan_head *)skb->data;
332 	key_vh->tci = vh->tci | htons(VLAN_TAG_PRESENT);
333 	key_vh->tpid = vh->tpid;
334 
335 	if (unlikely(untag_vlan)) {
336 		int offset = skb->data - skb_mac_header(skb);
337 		u16 tci;
338 		int err;
339 
340 		__skb_push(skb, offset);
341 		err = __skb_vlan_pop(skb, &tci);
342 		__skb_pull(skb, offset);
343 		if (err)
344 			return err;
345 		__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
346 	} else {
347 		__skb_pull(skb, sizeof(struct vlan_head));
348 	}
349 	return 1;
350 }
351 
352 static void clear_vlan(struct sw_flow_key *key)
353 {
354 	key->eth.vlan.tci = 0;
355 	key->eth.vlan.tpid = 0;
356 	key->eth.cvlan.tci = 0;
357 	key->eth.cvlan.tpid = 0;
358 }
359 
360 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
361 {
362 	int res;
363 
364 	if (skb_vlan_tag_present(skb)) {
365 		key->eth.vlan.tci = htons(skb->vlan_tci);
366 		key->eth.vlan.tpid = skb->vlan_proto;
367 	} else {
368 		/* Parse outer vlan tag in the non-accelerated case. */
369 		res = parse_vlan_tag(skb, &key->eth.vlan, true);
370 		if (res <= 0)
371 			return res;
372 	}
373 
374 	/* Parse inner vlan tag. */
375 	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
376 	if (res <= 0)
377 		return res;
378 
379 	return 0;
380 }
381 
382 static __be16 parse_ethertype(struct sk_buff *skb)
383 {
384 	struct llc_snap_hdr {
385 		u8  dsap;  /* Always 0xAA */
386 		u8  ssap;  /* Always 0xAA */
387 		u8  ctrl;
388 		u8  oui[3];
389 		__be16 ethertype;
390 	};
391 	struct llc_snap_hdr *llc;
392 	__be16 proto;
393 
394 	proto = *(__be16 *) skb->data;
395 	__skb_pull(skb, sizeof(__be16));
396 
397 	if (eth_proto_is_802_3(proto))
398 		return proto;
399 
400 	if (skb->len < sizeof(struct llc_snap_hdr))
401 		return htons(ETH_P_802_2);
402 
403 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
404 		return htons(0);
405 
406 	llc = (struct llc_snap_hdr *) skb->data;
407 	if (llc->dsap != LLC_SAP_SNAP ||
408 	    llc->ssap != LLC_SAP_SNAP ||
409 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
410 		return htons(ETH_P_802_2);
411 
412 	__skb_pull(skb, sizeof(struct llc_snap_hdr));
413 
414 	if (eth_proto_is_802_3(llc->ethertype))
415 		return llc->ethertype;
416 
417 	return htons(ETH_P_802_2);
418 }
419 
420 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
421 			int nh_len)
422 {
423 	struct icmp6hdr *icmp = icmp6_hdr(skb);
424 
425 	/* The ICMPv6 type and code fields use the 16-bit transport port
426 	 * fields, so we need to store them in 16-bit network byte order.
427 	 */
428 	key->tp.src = htons(icmp->icmp6_type);
429 	key->tp.dst = htons(icmp->icmp6_code);
430 	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));
431 
432 	if (icmp->icmp6_code == 0 &&
433 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
434 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
435 		int icmp_len = skb->len - skb_transport_offset(skb);
436 		struct nd_msg *nd;
437 		int offset;
438 
439 		/* In order to process neighbor discovery options, we need the
440 		 * entire packet.
441 		 */
442 		if (unlikely(icmp_len < sizeof(*nd)))
443 			return 0;
444 
445 		if (unlikely(skb_linearize(skb)))
446 			return -ENOMEM;
447 
448 		nd = (struct nd_msg *)skb_transport_header(skb);
449 		key->ipv6.nd.target = nd->target;
450 
451 		icmp_len -= sizeof(*nd);
452 		offset = 0;
453 		while (icmp_len >= 8) {
454 			struct nd_opt_hdr *nd_opt =
455 				 (struct nd_opt_hdr *)(nd->opt + offset);
456 			int opt_len = nd_opt->nd_opt_len * 8;
457 
458 			if (unlikely(!opt_len || opt_len > icmp_len))
459 				return 0;
460 
461 			/* Store the link layer address if the appropriate
462 			 * option is provided.  It is considered an error if
463 			 * the same link layer option is specified twice.
464 			 */
465 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
466 			    && opt_len == 8) {
467 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
468 					goto invalid;
469 				ether_addr_copy(key->ipv6.nd.sll,
470 						&nd->opt[offset+sizeof(*nd_opt)]);
471 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
472 				   && opt_len == 8) {
473 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
474 					goto invalid;
475 				ether_addr_copy(key->ipv6.nd.tll,
476 						&nd->opt[offset+sizeof(*nd_opt)]);
477 			}
478 
479 			icmp_len -= opt_len;
480 			offset += opt_len;
481 		}
482 	}
483 
484 	return 0;
485 
486 invalid:
487 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
488 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
489 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
490 
491 	return 0;
492 }
493 
494 static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
495 {
496 	struct nshhdr *nh;
497 	unsigned int nh_ofs = skb_network_offset(skb);
498 	u8 version, length;
499 	int err;
500 
501 	err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
502 	if (unlikely(err))
503 		return err;
504 
505 	nh = nsh_hdr(skb);
506 	version = nsh_get_ver(nh);
507 	length = nsh_hdr_len(nh);
508 
509 	if (version != 0)
510 		return -EINVAL;
511 
512 	err = check_header(skb, nh_ofs + length);
513 	if (unlikely(err))
514 		return err;
515 
516 	nh = nsh_hdr(skb);
517 	key->nsh.base.flags = nsh_get_flags(nh);
518 	key->nsh.base.ttl = nsh_get_ttl(nh);
519 	key->nsh.base.mdtype = nh->mdtype;
520 	key->nsh.base.np = nh->np;
521 	key->nsh.base.path_hdr = nh->path_hdr;
522 	switch (key->nsh.base.mdtype) {
523 	case NSH_M_TYPE1:
524 		if (length != NSH_M_TYPE1_LEN)
525 			return -EINVAL;
526 		memcpy(key->nsh.context, nh->md1.context,
527 		       sizeof(nh->md1));
528 		break;
529 	case NSH_M_TYPE2:
530 		memset(key->nsh.context, 0,
531 		       sizeof(nh->md1));
532 		break;
533 	default:
534 		return -EINVAL;
535 	}
536 
537 	return 0;
538 }
539 
540 /**
541  * key_extract - extracts a flow key from an Ethernet frame.
542  * @skb: sk_buff that contains the frame, with skb->data pointing to the
543  * Ethernet header
544  * @key: output flow key
545  *
546  * The caller must ensure that skb->len >= ETH_HLEN.
547  *
548  * Returns 0 if successful, otherwise a negative errno value.
549  *
550  * Initializes @skb header fields as follows:
551  *
552  *    - skb->mac_header: the L2 header.
553  *
554  *    - skb->network_header: just past the L2 header, or just past the
555  *      VLAN header, to the first byte of the L2 payload.
556  *
557  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
558  *      on output, then just past the IP header, if one is present and
559  *      of a correct length, otherwise the same as skb->network_header.
560  *      For other key->eth.type values it is left untouched.
561  *
562  *    - skb->protocol: the type of the data starting at skb->network_header.
563  *      Equals to key->eth.type.
564  */
565 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
566 {
567 	int error;
568 	struct ethhdr *eth;
569 
570 	/* Flags are always used as part of stats */
571 	key->tp.flags = 0;
572 
573 	skb_reset_mac_header(skb);
574 
575 	/* Link layer. */
576 	clear_vlan(key);
577 	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
578 		if (unlikely(eth_type_vlan(skb->protocol)))
579 			return -EINVAL;
580 
581 		skb_reset_network_header(skb);
582 		key->eth.type = skb->protocol;
583 	} else {
584 		eth = eth_hdr(skb);
585 		ether_addr_copy(key->eth.src, eth->h_source);
586 		ether_addr_copy(key->eth.dst, eth->h_dest);
587 
588 		__skb_pull(skb, 2 * ETH_ALEN);
589 		/* We are going to push all headers that we pull, so no need to
590 		* update skb->csum here.
591 		*/
592 
593 		if (unlikely(parse_vlan(skb, key)))
594 			return -ENOMEM;
595 
596 		key->eth.type = parse_ethertype(skb);
597 		if (unlikely(key->eth.type == htons(0)))
598 			return -ENOMEM;
599 
600 		/* Multiple tagged packets need to retain TPID to satisfy
601 		 * skb_vlan_pop(), which will later shift the ethertype into
602 		 * skb->protocol.
603 		 */
604 		if (key->eth.cvlan.tci & htons(VLAN_TAG_PRESENT))
605 			skb->protocol = key->eth.cvlan.tpid;
606 		else
607 			skb->protocol = key->eth.type;
608 
609 		skb_reset_network_header(skb);
610 		__skb_push(skb, skb->data - skb_mac_header(skb));
611 	}
612 	skb_reset_mac_len(skb);
613 
614 	/* Network layer. */
615 	if (key->eth.type == htons(ETH_P_IP)) {
616 		struct iphdr *nh;
617 		__be16 offset;
618 
619 		error = check_iphdr(skb);
620 		if (unlikely(error)) {
621 			memset(&key->ip, 0, sizeof(key->ip));
622 			memset(&key->ipv4, 0, sizeof(key->ipv4));
623 			if (error == -EINVAL) {
624 				skb->transport_header = skb->network_header;
625 				error = 0;
626 			}
627 			return error;
628 		}
629 
630 		nh = ip_hdr(skb);
631 		key->ipv4.addr.src = nh->saddr;
632 		key->ipv4.addr.dst = nh->daddr;
633 
634 		key->ip.proto = nh->protocol;
635 		key->ip.tos = nh->tos;
636 		key->ip.ttl = nh->ttl;
637 
638 		offset = nh->frag_off & htons(IP_OFFSET);
639 		if (offset) {
640 			key->ip.frag = OVS_FRAG_TYPE_LATER;
641 			return 0;
642 		}
643 		if (nh->frag_off & htons(IP_MF) ||
644 			skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
645 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
646 		else
647 			key->ip.frag = OVS_FRAG_TYPE_NONE;
648 
649 		/* Transport layer. */
650 		if (key->ip.proto == IPPROTO_TCP) {
651 			if (tcphdr_ok(skb)) {
652 				struct tcphdr *tcp = tcp_hdr(skb);
653 				key->tp.src = tcp->source;
654 				key->tp.dst = tcp->dest;
655 				key->tp.flags = TCP_FLAGS_BE16(tcp);
656 			} else {
657 				memset(&key->tp, 0, sizeof(key->tp));
658 			}
659 
660 		} else if (key->ip.proto == IPPROTO_UDP) {
661 			if (udphdr_ok(skb)) {
662 				struct udphdr *udp = udp_hdr(skb);
663 				key->tp.src = udp->source;
664 				key->tp.dst = udp->dest;
665 			} else {
666 				memset(&key->tp, 0, sizeof(key->tp));
667 			}
668 		} else if (key->ip.proto == IPPROTO_SCTP) {
669 			if (sctphdr_ok(skb)) {
670 				struct sctphdr *sctp = sctp_hdr(skb);
671 				key->tp.src = sctp->source;
672 				key->tp.dst = sctp->dest;
673 			} else {
674 				memset(&key->tp, 0, sizeof(key->tp));
675 			}
676 		} else if (key->ip.proto == IPPROTO_ICMP) {
677 			if (icmphdr_ok(skb)) {
678 				struct icmphdr *icmp = icmp_hdr(skb);
679 				/* The ICMP type and code fields use the 16-bit
680 				 * transport port fields, so we need to store
681 				 * them in 16-bit network byte order. */
682 				key->tp.src = htons(icmp->type);
683 				key->tp.dst = htons(icmp->code);
684 			} else {
685 				memset(&key->tp, 0, sizeof(key->tp));
686 			}
687 		}
688 
689 	} else if (key->eth.type == htons(ETH_P_ARP) ||
690 		   key->eth.type == htons(ETH_P_RARP)) {
691 		struct arp_eth_header *arp;
692 		bool arp_available = arphdr_ok(skb);
693 
694 		arp = (struct arp_eth_header *)skb_network_header(skb);
695 
696 		if (arp_available &&
697 		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
698 		    arp->ar_pro == htons(ETH_P_IP) &&
699 		    arp->ar_hln == ETH_ALEN &&
700 		    arp->ar_pln == 4) {
701 
702 			/* We only match on the lower 8 bits of the opcode. */
703 			if (ntohs(arp->ar_op) <= 0xff)
704 				key->ip.proto = ntohs(arp->ar_op);
705 			else
706 				key->ip.proto = 0;
707 
708 			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
709 			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
710 			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
711 			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
712 		} else {
713 			memset(&key->ip, 0, sizeof(key->ip));
714 			memset(&key->ipv4, 0, sizeof(key->ipv4));
715 		}
716 	} else if (eth_p_mpls(key->eth.type)) {
717 		size_t stack_len = MPLS_HLEN;
718 
719 		skb_set_inner_network_header(skb, skb->mac_len);
720 		while (1) {
721 			__be32 lse;
722 
723 			error = check_header(skb, skb->mac_len + stack_len);
724 			if (unlikely(error))
725 				return 0;
726 
727 			memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
728 
729 			if (stack_len == MPLS_HLEN)
730 				memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);
731 
732 			skb_set_inner_network_header(skb, skb->mac_len + stack_len);
733 			if (lse & htonl(MPLS_LS_S_MASK))
734 				break;
735 
736 			stack_len += MPLS_HLEN;
737 		}
738 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
739 		int nh_len;             /* IPv6 Header + Extensions */
740 
741 		nh_len = parse_ipv6hdr(skb, key);
742 		if (unlikely(nh_len < 0)) {
743 			switch (nh_len) {
744 			case -EINVAL:
745 				memset(&key->ip, 0, sizeof(key->ip));
746 				memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
747 				/* fall-through */
748 			case -EPROTO:
749 				skb->transport_header = skb->network_header;
750 				error = 0;
751 				break;
752 			default:
753 				error = nh_len;
754 			}
755 			return error;
756 		}
757 
758 		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
759 			return 0;
760 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
761 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
762 
763 		/* Transport layer. */
764 		if (key->ip.proto == NEXTHDR_TCP) {
765 			if (tcphdr_ok(skb)) {
766 				struct tcphdr *tcp = tcp_hdr(skb);
767 				key->tp.src = tcp->source;
768 				key->tp.dst = tcp->dest;
769 				key->tp.flags = TCP_FLAGS_BE16(tcp);
770 			} else {
771 				memset(&key->tp, 0, sizeof(key->tp));
772 			}
773 		} else if (key->ip.proto == NEXTHDR_UDP) {
774 			if (udphdr_ok(skb)) {
775 				struct udphdr *udp = udp_hdr(skb);
776 				key->tp.src = udp->source;
777 				key->tp.dst = udp->dest;
778 			} else {
779 				memset(&key->tp, 0, sizeof(key->tp));
780 			}
781 		} else if (key->ip.proto == NEXTHDR_SCTP) {
782 			if (sctphdr_ok(skb)) {
783 				struct sctphdr *sctp = sctp_hdr(skb);
784 				key->tp.src = sctp->source;
785 				key->tp.dst = sctp->dest;
786 			} else {
787 				memset(&key->tp, 0, sizeof(key->tp));
788 			}
789 		} else if (key->ip.proto == NEXTHDR_ICMP) {
790 			if (icmp6hdr_ok(skb)) {
791 				error = parse_icmpv6(skb, key, nh_len);
792 				if (error)
793 					return error;
794 			} else {
795 				memset(&key->tp, 0, sizeof(key->tp));
796 			}
797 		}
798 	} else if (key->eth.type == htons(ETH_P_NSH)) {
799 		error = parse_nsh(skb, key);
800 		if (error)
801 			return error;
802 	}
803 	return 0;
804 }
805 
806 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
807 {
808 	int res;
809 
810 	res = key_extract(skb, key);
811 	if (!res)
812 		key->mac_proto &= ~SW_FLOW_KEY_INVALID;
813 
814 	return res;
815 }
816 
817 static int key_extract_mac_proto(struct sk_buff *skb)
818 {
819 	switch (skb->dev->type) {
820 	case ARPHRD_ETHER:
821 		return MAC_PROTO_ETHERNET;
822 	case ARPHRD_NONE:
823 		if (skb->protocol == htons(ETH_P_TEB))
824 			return MAC_PROTO_ETHERNET;
825 		return MAC_PROTO_NONE;
826 	}
827 	WARN_ON_ONCE(1);
828 	return -EINVAL;
829 }
830 
831 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
832 			 struct sk_buff *skb, struct sw_flow_key *key)
833 {
834 	int res, err;
835 
836 	/* Extract metadata from packet. */
837 	if (tun_info) {
838 		key->tun_proto = ip_tunnel_info_af(tun_info);
839 		memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
840 
841 		if (tun_info->options_len) {
842 			BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
843 						   8)) - 1
844 					> sizeof(key->tun_opts));
845 
846 			ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
847 						tun_info);
848 			key->tun_opts_len = tun_info->options_len;
849 		} else {
850 			key->tun_opts_len = 0;
851 		}
852 	} else  {
853 		key->tun_proto = 0;
854 		key->tun_opts_len = 0;
855 		memset(&key->tun_key, 0, sizeof(key->tun_key));
856 	}
857 
858 	key->phy.priority = skb->priority;
859 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
860 	key->phy.skb_mark = skb->mark;
861 	key->ovs_flow_hash = 0;
862 	res = key_extract_mac_proto(skb);
863 	if (res < 0)
864 		return res;
865 	key->mac_proto = res;
866 	key->recirc_id = 0;
867 
868 	err = key_extract(skb, key);
869 	if (!err)
870 		ovs_ct_fill_key(skb, key);   /* Must be after key_extract(). */
871 	return err;
872 }
873 
874 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
875 				   struct sk_buff *skb,
876 				   struct sw_flow_key *key, bool log)
877 {
878 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
879 	u64 attrs = 0;
880 	int err;
881 
882 	err = parse_flow_nlattrs(attr, a, &attrs, log);
883 	if (err)
884 		return -EINVAL;
885 
886 	/* Extract metadata from netlink attributes. */
887 	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
888 	if (err)
889 		return err;
890 
891 	/* key_extract assumes that skb->protocol is set-up for
892 	 * layer 3 packets which is the case for other callers,
893 	 * in particular packets received from the network stack.
894 	 * Here the correct value can be set from the metadata
895 	 * extracted above.
896 	 * For L2 packet key eth type would be zero. skb protocol
897 	 * would be set to correct value later during key-extact.
898 	 */
899 
900 	skb->protocol = key->eth.type;
901 	err = key_extract(skb, key);
902 	if (err)
903 		return err;
904 
905 	/* Check that we have conntrack original direction tuple metadata only
906 	 * for packets for which it makes sense.  Otherwise the key may be
907 	 * corrupted due to overlapping key fields.
908 	 */
909 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
910 	    key->eth.type != htons(ETH_P_IP))
911 		return -EINVAL;
912 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
913 	    (key->eth.type != htons(ETH_P_IPV6) ||
914 	     sw_flow_key_is_nd(key)))
915 		return -EINVAL;
916 
917 	return 0;
918 }
919