xref: /openbmc/linux/net/openvswitch/flow.c (revision 176f011b)
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 short frag_off;
258 	unsigned int payload_ofs = 0;
259 	unsigned int nh_ofs = skb_network_offset(skb);
260 	unsigned int nh_len;
261 	struct ipv6hdr *nh;
262 	int err, nexthdr, flags = 0;
263 
264 	err = check_header(skb, nh_ofs + sizeof(*nh));
265 	if (unlikely(err))
266 		return err;
267 
268 	nh = ipv6_hdr(skb);
269 
270 	key->ip.proto = NEXTHDR_NONE;
271 	key->ip.tos = ipv6_get_dsfield(nh);
272 	key->ip.ttl = nh->hop_limit;
273 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
274 	key->ipv6.addr.src = nh->saddr;
275 	key->ipv6.addr.dst = nh->daddr;
276 
277 	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
278 	if (flags & IP6_FH_F_FRAG) {
279 		if (frag_off) {
280 			key->ip.frag = OVS_FRAG_TYPE_LATER;
281 			key->ip.proto = nexthdr;
282 			return 0;
283 		}
284 		key->ip.frag = OVS_FRAG_TYPE_FIRST;
285 	} else {
286 		key->ip.frag = OVS_FRAG_TYPE_NONE;
287 	}
288 
289 	/* Delayed handling of error in ipv6_find_hdr() as it
290 	 * always sets flags and frag_off to a valid value which may be
291 	 * used to set key->ip.frag above.
292 	 */
293 	if (unlikely(nexthdr < 0))
294 		return -EPROTO;
295 
296 	nh_len = payload_ofs - nh_ofs;
297 	skb_set_transport_header(skb, nh_ofs + nh_len);
298 	key->ip.proto = nexthdr;
299 	return nh_len;
300 }
301 
302 static bool icmp6hdr_ok(struct sk_buff *skb)
303 {
304 	return pskb_may_pull(skb, skb_transport_offset(skb) +
305 				  sizeof(struct icmp6hdr));
306 }
307 
308 /**
309  * Parse vlan tag from vlan header.
310  * Returns ERROR on memory error.
311  * Returns 0 if it encounters a non-vlan or incomplete packet.
312  * Returns 1 after successfully parsing vlan tag.
313  */
314 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
315 			  bool untag_vlan)
316 {
317 	struct vlan_head *vh = (struct vlan_head *)skb->data;
318 
319 	if (likely(!eth_type_vlan(vh->tpid)))
320 		return 0;
321 
322 	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
323 		return 0;
324 
325 	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
326 				 sizeof(__be16))))
327 		return -ENOMEM;
328 
329 	vh = (struct vlan_head *)skb->data;
330 	key_vh->tci = vh->tci | htons(VLAN_CFI_MASK);
331 	key_vh->tpid = vh->tpid;
332 
333 	if (unlikely(untag_vlan)) {
334 		int offset = skb->data - skb_mac_header(skb);
335 		u16 tci;
336 		int err;
337 
338 		__skb_push(skb, offset);
339 		err = __skb_vlan_pop(skb, &tci);
340 		__skb_pull(skb, offset);
341 		if (err)
342 			return err;
343 		__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
344 	} else {
345 		__skb_pull(skb, sizeof(struct vlan_head));
346 	}
347 	return 1;
348 }
349 
350 static void clear_vlan(struct sw_flow_key *key)
351 {
352 	key->eth.vlan.tci = 0;
353 	key->eth.vlan.tpid = 0;
354 	key->eth.cvlan.tci = 0;
355 	key->eth.cvlan.tpid = 0;
356 }
357 
358 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
359 {
360 	int res;
361 
362 	if (skb_vlan_tag_present(skb)) {
363 		key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK);
364 		key->eth.vlan.tpid = skb->vlan_proto;
365 	} else {
366 		/* Parse outer vlan tag in the non-accelerated case. */
367 		res = parse_vlan_tag(skb, &key->eth.vlan, true);
368 		if (res <= 0)
369 			return res;
370 	}
371 
372 	/* Parse inner vlan tag. */
373 	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
374 	if (res <= 0)
375 		return res;
376 
377 	return 0;
378 }
379 
380 static __be16 parse_ethertype(struct sk_buff *skb)
381 {
382 	struct llc_snap_hdr {
383 		u8  dsap;  /* Always 0xAA */
384 		u8  ssap;  /* Always 0xAA */
385 		u8  ctrl;
386 		u8  oui[3];
387 		__be16 ethertype;
388 	};
389 	struct llc_snap_hdr *llc;
390 	__be16 proto;
391 
392 	proto = *(__be16 *) skb->data;
393 	__skb_pull(skb, sizeof(__be16));
394 
395 	if (eth_proto_is_802_3(proto))
396 		return proto;
397 
398 	if (skb->len < sizeof(struct llc_snap_hdr))
399 		return htons(ETH_P_802_2);
400 
401 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
402 		return htons(0);
403 
404 	llc = (struct llc_snap_hdr *) skb->data;
405 	if (llc->dsap != LLC_SAP_SNAP ||
406 	    llc->ssap != LLC_SAP_SNAP ||
407 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
408 		return htons(ETH_P_802_2);
409 
410 	__skb_pull(skb, sizeof(struct llc_snap_hdr));
411 
412 	if (eth_proto_is_802_3(llc->ethertype))
413 		return llc->ethertype;
414 
415 	return htons(ETH_P_802_2);
416 }
417 
418 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
419 			int nh_len)
420 {
421 	struct icmp6hdr *icmp = icmp6_hdr(skb);
422 
423 	/* The ICMPv6 type and code fields use the 16-bit transport port
424 	 * fields, so we need to store them in 16-bit network byte order.
425 	 */
426 	key->tp.src = htons(icmp->icmp6_type);
427 	key->tp.dst = htons(icmp->icmp6_code);
428 	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));
429 
430 	if (icmp->icmp6_code == 0 &&
431 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
432 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
433 		int icmp_len = skb->len - skb_transport_offset(skb);
434 		struct nd_msg *nd;
435 		int offset;
436 
437 		/* In order to process neighbor discovery options, we need the
438 		 * entire packet.
439 		 */
440 		if (unlikely(icmp_len < sizeof(*nd)))
441 			return 0;
442 
443 		if (unlikely(skb_linearize(skb)))
444 			return -ENOMEM;
445 
446 		nd = (struct nd_msg *)skb_transport_header(skb);
447 		key->ipv6.nd.target = nd->target;
448 
449 		icmp_len -= sizeof(*nd);
450 		offset = 0;
451 		while (icmp_len >= 8) {
452 			struct nd_opt_hdr *nd_opt =
453 				 (struct nd_opt_hdr *)(nd->opt + offset);
454 			int opt_len = nd_opt->nd_opt_len * 8;
455 
456 			if (unlikely(!opt_len || opt_len > icmp_len))
457 				return 0;
458 
459 			/* Store the link layer address if the appropriate
460 			 * option is provided.  It is considered an error if
461 			 * the same link layer option is specified twice.
462 			 */
463 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
464 			    && opt_len == 8) {
465 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
466 					goto invalid;
467 				ether_addr_copy(key->ipv6.nd.sll,
468 						&nd->opt[offset+sizeof(*nd_opt)]);
469 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
470 				   && opt_len == 8) {
471 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
472 					goto invalid;
473 				ether_addr_copy(key->ipv6.nd.tll,
474 						&nd->opt[offset+sizeof(*nd_opt)]);
475 			}
476 
477 			icmp_len -= opt_len;
478 			offset += opt_len;
479 		}
480 	}
481 
482 	return 0;
483 
484 invalid:
485 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
486 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
487 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
488 
489 	return 0;
490 }
491 
492 static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
493 {
494 	struct nshhdr *nh;
495 	unsigned int nh_ofs = skb_network_offset(skb);
496 	u8 version, length;
497 	int err;
498 
499 	err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
500 	if (unlikely(err))
501 		return err;
502 
503 	nh = nsh_hdr(skb);
504 	version = nsh_get_ver(nh);
505 	length = nsh_hdr_len(nh);
506 
507 	if (version != 0)
508 		return -EINVAL;
509 
510 	err = check_header(skb, nh_ofs + length);
511 	if (unlikely(err))
512 		return err;
513 
514 	nh = nsh_hdr(skb);
515 	key->nsh.base.flags = nsh_get_flags(nh);
516 	key->nsh.base.ttl = nsh_get_ttl(nh);
517 	key->nsh.base.mdtype = nh->mdtype;
518 	key->nsh.base.np = nh->np;
519 	key->nsh.base.path_hdr = nh->path_hdr;
520 	switch (key->nsh.base.mdtype) {
521 	case NSH_M_TYPE1:
522 		if (length != NSH_M_TYPE1_LEN)
523 			return -EINVAL;
524 		memcpy(key->nsh.context, nh->md1.context,
525 		       sizeof(nh->md1));
526 		break;
527 	case NSH_M_TYPE2:
528 		memset(key->nsh.context, 0,
529 		       sizeof(nh->md1));
530 		break;
531 	default:
532 		return -EINVAL;
533 	}
534 
535 	return 0;
536 }
537 
538 /**
539  * key_extract - extracts a flow key from an Ethernet frame.
540  * @skb: sk_buff that contains the frame, with skb->data pointing to the
541  * Ethernet header
542  * @key: output flow key
543  *
544  * The caller must ensure that skb->len >= ETH_HLEN.
545  *
546  * Returns 0 if successful, otherwise a negative errno value.
547  *
548  * Initializes @skb header fields as follows:
549  *
550  *    - skb->mac_header: the L2 header.
551  *
552  *    - skb->network_header: just past the L2 header, or just past the
553  *      VLAN header, to the first byte of the L2 payload.
554  *
555  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
556  *      on output, then just past the IP header, if one is present and
557  *      of a correct length, otherwise the same as skb->network_header.
558  *      For other key->eth.type values it is left untouched.
559  *
560  *    - skb->protocol: the type of the data starting at skb->network_header.
561  *      Equals to key->eth.type.
562  */
563 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
564 {
565 	int error;
566 	struct ethhdr *eth;
567 
568 	/* Flags are always used as part of stats */
569 	key->tp.flags = 0;
570 
571 	skb_reset_mac_header(skb);
572 
573 	/* Link layer. */
574 	clear_vlan(key);
575 	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
576 		if (unlikely(eth_type_vlan(skb->protocol)))
577 			return -EINVAL;
578 
579 		skb_reset_network_header(skb);
580 		key->eth.type = skb->protocol;
581 	} else {
582 		eth = eth_hdr(skb);
583 		ether_addr_copy(key->eth.src, eth->h_source);
584 		ether_addr_copy(key->eth.dst, eth->h_dest);
585 
586 		__skb_pull(skb, 2 * ETH_ALEN);
587 		/* We are going to push all headers that we pull, so no need to
588 		* update skb->csum here.
589 		*/
590 
591 		if (unlikely(parse_vlan(skb, key)))
592 			return -ENOMEM;
593 
594 		key->eth.type = parse_ethertype(skb);
595 		if (unlikely(key->eth.type == htons(0)))
596 			return -ENOMEM;
597 
598 		/* Multiple tagged packets need to retain TPID to satisfy
599 		 * skb_vlan_pop(), which will later shift the ethertype into
600 		 * skb->protocol.
601 		 */
602 		if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK))
603 			skb->protocol = key->eth.cvlan.tpid;
604 		else
605 			skb->protocol = key->eth.type;
606 
607 		skb_reset_network_header(skb);
608 		__skb_push(skb, skb->data - skb_mac_header(skb));
609 	}
610 	skb_reset_mac_len(skb);
611 
612 	/* Network layer. */
613 	if (key->eth.type == htons(ETH_P_IP)) {
614 		struct iphdr *nh;
615 		__be16 offset;
616 
617 		error = check_iphdr(skb);
618 		if (unlikely(error)) {
619 			memset(&key->ip, 0, sizeof(key->ip));
620 			memset(&key->ipv4, 0, sizeof(key->ipv4));
621 			if (error == -EINVAL) {
622 				skb->transport_header = skb->network_header;
623 				error = 0;
624 			}
625 			return error;
626 		}
627 
628 		nh = ip_hdr(skb);
629 		key->ipv4.addr.src = nh->saddr;
630 		key->ipv4.addr.dst = nh->daddr;
631 
632 		key->ip.proto = nh->protocol;
633 		key->ip.tos = nh->tos;
634 		key->ip.ttl = nh->ttl;
635 
636 		offset = nh->frag_off & htons(IP_OFFSET);
637 		if (offset) {
638 			key->ip.frag = OVS_FRAG_TYPE_LATER;
639 			return 0;
640 		}
641 		if (nh->frag_off & htons(IP_MF) ||
642 			skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
643 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
644 		else
645 			key->ip.frag = OVS_FRAG_TYPE_NONE;
646 
647 		/* Transport layer. */
648 		if (key->ip.proto == IPPROTO_TCP) {
649 			if (tcphdr_ok(skb)) {
650 				struct tcphdr *tcp = tcp_hdr(skb);
651 				key->tp.src = tcp->source;
652 				key->tp.dst = tcp->dest;
653 				key->tp.flags = TCP_FLAGS_BE16(tcp);
654 			} else {
655 				memset(&key->tp, 0, sizeof(key->tp));
656 			}
657 
658 		} else if (key->ip.proto == IPPROTO_UDP) {
659 			if (udphdr_ok(skb)) {
660 				struct udphdr *udp = udp_hdr(skb);
661 				key->tp.src = udp->source;
662 				key->tp.dst = udp->dest;
663 			} else {
664 				memset(&key->tp, 0, sizeof(key->tp));
665 			}
666 		} else if (key->ip.proto == IPPROTO_SCTP) {
667 			if (sctphdr_ok(skb)) {
668 				struct sctphdr *sctp = sctp_hdr(skb);
669 				key->tp.src = sctp->source;
670 				key->tp.dst = sctp->dest;
671 			} else {
672 				memset(&key->tp, 0, sizeof(key->tp));
673 			}
674 		} else if (key->ip.proto == IPPROTO_ICMP) {
675 			if (icmphdr_ok(skb)) {
676 				struct icmphdr *icmp = icmp_hdr(skb);
677 				/* The ICMP type and code fields use the 16-bit
678 				 * transport port fields, so we need to store
679 				 * them in 16-bit network byte order. */
680 				key->tp.src = htons(icmp->type);
681 				key->tp.dst = htons(icmp->code);
682 			} else {
683 				memset(&key->tp, 0, sizeof(key->tp));
684 			}
685 		}
686 
687 	} else if (key->eth.type == htons(ETH_P_ARP) ||
688 		   key->eth.type == htons(ETH_P_RARP)) {
689 		struct arp_eth_header *arp;
690 		bool arp_available = arphdr_ok(skb);
691 
692 		arp = (struct arp_eth_header *)skb_network_header(skb);
693 
694 		if (arp_available &&
695 		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
696 		    arp->ar_pro == htons(ETH_P_IP) &&
697 		    arp->ar_hln == ETH_ALEN &&
698 		    arp->ar_pln == 4) {
699 
700 			/* We only match on the lower 8 bits of the opcode. */
701 			if (ntohs(arp->ar_op) <= 0xff)
702 				key->ip.proto = ntohs(arp->ar_op);
703 			else
704 				key->ip.proto = 0;
705 
706 			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
707 			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
708 			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
709 			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
710 		} else {
711 			memset(&key->ip, 0, sizeof(key->ip));
712 			memset(&key->ipv4, 0, sizeof(key->ipv4));
713 		}
714 	} else if (eth_p_mpls(key->eth.type)) {
715 		size_t stack_len = MPLS_HLEN;
716 
717 		skb_set_inner_network_header(skb, skb->mac_len);
718 		while (1) {
719 			__be32 lse;
720 
721 			error = check_header(skb, skb->mac_len + stack_len);
722 			if (unlikely(error))
723 				return 0;
724 
725 			memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
726 
727 			if (stack_len == MPLS_HLEN)
728 				memcpy(&key->mpls.top_lse, &lse, MPLS_HLEN);
729 
730 			skb_set_inner_network_header(skb, skb->mac_len + stack_len);
731 			if (lse & htonl(MPLS_LS_S_MASK))
732 				break;
733 
734 			stack_len += MPLS_HLEN;
735 		}
736 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
737 		int nh_len;             /* IPv6 Header + Extensions */
738 
739 		nh_len = parse_ipv6hdr(skb, key);
740 		if (unlikely(nh_len < 0)) {
741 			switch (nh_len) {
742 			case -EINVAL:
743 				memset(&key->ip, 0, sizeof(key->ip));
744 				memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
745 				/* fall-through */
746 			case -EPROTO:
747 				skb->transport_header = skb->network_header;
748 				error = 0;
749 				break;
750 			default:
751 				error = nh_len;
752 			}
753 			return error;
754 		}
755 
756 		if (key->ip.frag == OVS_FRAG_TYPE_LATER)
757 			return 0;
758 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
759 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
760 
761 		/* Transport layer. */
762 		if (key->ip.proto == NEXTHDR_TCP) {
763 			if (tcphdr_ok(skb)) {
764 				struct tcphdr *tcp = tcp_hdr(skb);
765 				key->tp.src = tcp->source;
766 				key->tp.dst = tcp->dest;
767 				key->tp.flags = TCP_FLAGS_BE16(tcp);
768 			} else {
769 				memset(&key->tp, 0, sizeof(key->tp));
770 			}
771 		} else if (key->ip.proto == NEXTHDR_UDP) {
772 			if (udphdr_ok(skb)) {
773 				struct udphdr *udp = udp_hdr(skb);
774 				key->tp.src = udp->source;
775 				key->tp.dst = udp->dest;
776 			} else {
777 				memset(&key->tp, 0, sizeof(key->tp));
778 			}
779 		} else if (key->ip.proto == NEXTHDR_SCTP) {
780 			if (sctphdr_ok(skb)) {
781 				struct sctphdr *sctp = sctp_hdr(skb);
782 				key->tp.src = sctp->source;
783 				key->tp.dst = sctp->dest;
784 			} else {
785 				memset(&key->tp, 0, sizeof(key->tp));
786 			}
787 		} else if (key->ip.proto == NEXTHDR_ICMP) {
788 			if (icmp6hdr_ok(skb)) {
789 				error = parse_icmpv6(skb, key, nh_len);
790 				if (error)
791 					return error;
792 			} else {
793 				memset(&key->tp, 0, sizeof(key->tp));
794 			}
795 		}
796 	} else if (key->eth.type == htons(ETH_P_NSH)) {
797 		error = parse_nsh(skb, key);
798 		if (error)
799 			return error;
800 	}
801 	return 0;
802 }
803 
804 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
805 {
806 	int res;
807 
808 	res = key_extract(skb, key);
809 	if (!res)
810 		key->mac_proto &= ~SW_FLOW_KEY_INVALID;
811 
812 	return res;
813 }
814 
815 static int key_extract_mac_proto(struct sk_buff *skb)
816 {
817 	switch (skb->dev->type) {
818 	case ARPHRD_ETHER:
819 		return MAC_PROTO_ETHERNET;
820 	case ARPHRD_NONE:
821 		if (skb->protocol == htons(ETH_P_TEB))
822 			return MAC_PROTO_ETHERNET;
823 		return MAC_PROTO_NONE;
824 	}
825 	WARN_ON_ONCE(1);
826 	return -EINVAL;
827 }
828 
829 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
830 			 struct sk_buff *skb, struct sw_flow_key *key)
831 {
832 	int res, err;
833 
834 	/* Extract metadata from packet. */
835 	if (tun_info) {
836 		key->tun_proto = ip_tunnel_info_af(tun_info);
837 		memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
838 
839 		if (tun_info->options_len) {
840 			BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
841 						   8)) - 1
842 					> sizeof(key->tun_opts));
843 
844 			ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
845 						tun_info);
846 			key->tun_opts_len = tun_info->options_len;
847 		} else {
848 			key->tun_opts_len = 0;
849 		}
850 	} else  {
851 		key->tun_proto = 0;
852 		key->tun_opts_len = 0;
853 		memset(&key->tun_key, 0, sizeof(key->tun_key));
854 	}
855 
856 	key->phy.priority = skb->priority;
857 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
858 	key->phy.skb_mark = skb->mark;
859 	key->ovs_flow_hash = 0;
860 	res = key_extract_mac_proto(skb);
861 	if (res < 0)
862 		return res;
863 	key->mac_proto = res;
864 	key->recirc_id = 0;
865 
866 	err = key_extract(skb, key);
867 	if (!err)
868 		ovs_ct_fill_key(skb, key);   /* Must be after key_extract(). */
869 	return err;
870 }
871 
872 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
873 				   struct sk_buff *skb,
874 				   struct sw_flow_key *key, bool log)
875 {
876 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
877 	u64 attrs = 0;
878 	int err;
879 
880 	err = parse_flow_nlattrs(attr, a, &attrs, log);
881 	if (err)
882 		return -EINVAL;
883 
884 	/* Extract metadata from netlink attributes. */
885 	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
886 	if (err)
887 		return err;
888 
889 	/* key_extract assumes that skb->protocol is set-up for
890 	 * layer 3 packets which is the case for other callers,
891 	 * in particular packets received from the network stack.
892 	 * Here the correct value can be set from the metadata
893 	 * extracted above.
894 	 * For L2 packet key eth type would be zero. skb protocol
895 	 * would be set to correct value later during key-extact.
896 	 */
897 
898 	skb->protocol = key->eth.type;
899 	err = key_extract(skb, key);
900 	if (err)
901 		return err;
902 
903 	/* Check that we have conntrack original direction tuple metadata only
904 	 * for packets for which it makes sense.  Otherwise the key may be
905 	 * corrupted due to overlapping key fields.
906 	 */
907 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
908 	    key->eth.type != htons(ETH_P_IP))
909 		return -EINVAL;
910 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
911 	    (key->eth.type != htons(ETH_P_IPV6) ||
912 	     sw_flow_key_is_nd(key)))
913 		return -EINVAL;
914 
915 	return 0;
916 }
917