xref: /openbmc/linux/net/openvswitch/flow.c (revision e40573a4)
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, &flow->cpu_used_mask);
111 					goto unlock;
112 				}
113 			}
114 			flow->stats_last_writer = cpu;
115 		}
116 	}
117 
118 	stats->used = jiffies;
119 	stats->packet_count++;
120 	stats->byte_count += len;
121 	stats->tcp_flags |= tcp_flags;
122 unlock:
123 	spin_unlock(&stats->lock);
124 }
125 
126 /* Must be called with rcu_read_lock or ovs_mutex. */
127 void ovs_flow_stats_get(const struct sw_flow *flow,
128 			struct ovs_flow_stats *ovs_stats,
129 			unsigned long *used, __be16 *tcp_flags)
130 {
131 	int cpu;
132 
133 	*used = 0;
134 	*tcp_flags = 0;
135 	memset(ovs_stats, 0, sizeof(*ovs_stats));
136 
137 	/* We open code this to make sure cpu 0 is always considered */
138 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
139 		struct sw_flow_stats *stats = rcu_dereference_ovsl(flow->stats[cpu]);
140 
141 		if (stats) {
142 			/* Local CPU may write on non-local stats, so we must
143 			 * block bottom-halves here.
144 			 */
145 			spin_lock_bh(&stats->lock);
146 			if (!*used || time_after(stats->used, *used))
147 				*used = stats->used;
148 			*tcp_flags |= stats->tcp_flags;
149 			ovs_stats->n_packets += stats->packet_count;
150 			ovs_stats->n_bytes += stats->byte_count;
151 			spin_unlock_bh(&stats->lock);
152 		}
153 	}
154 }
155 
156 /* Called with ovs_mutex. */
157 void ovs_flow_stats_clear(struct sw_flow *flow)
158 {
159 	int cpu;
160 
161 	/* We open code this to make sure cpu 0 is always considered */
162 	for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
163 		struct sw_flow_stats *stats = ovsl_dereference(flow->stats[cpu]);
164 
165 		if (stats) {
166 			spin_lock_bh(&stats->lock);
167 			stats->used = 0;
168 			stats->packet_count = 0;
169 			stats->byte_count = 0;
170 			stats->tcp_flags = 0;
171 			spin_unlock_bh(&stats->lock);
172 		}
173 	}
174 }
175 
176 static int check_header(struct sk_buff *skb, int len)
177 {
178 	if (unlikely(skb->len < len))
179 		return -EINVAL;
180 	if (unlikely(!pskb_may_pull(skb, len)))
181 		return -ENOMEM;
182 	return 0;
183 }
184 
185 static bool arphdr_ok(struct sk_buff *skb)
186 {
187 	return pskb_may_pull(skb, skb_network_offset(skb) +
188 				  sizeof(struct arp_eth_header));
189 }
190 
191 static int check_iphdr(struct sk_buff *skb)
192 {
193 	unsigned int nh_ofs = skb_network_offset(skb);
194 	unsigned int ip_len;
195 	int err;
196 
197 	err = check_header(skb, nh_ofs + sizeof(struct iphdr));
198 	if (unlikely(err))
199 		return err;
200 
201 	ip_len = ip_hdrlen(skb);
202 	if (unlikely(ip_len < sizeof(struct iphdr) ||
203 		     skb->len < nh_ofs + ip_len))
204 		return -EINVAL;
205 
206 	skb_set_transport_header(skb, nh_ofs + ip_len);
207 	return 0;
208 }
209 
210 static bool tcphdr_ok(struct sk_buff *skb)
211 {
212 	int th_ofs = skb_transport_offset(skb);
213 	int tcp_len;
214 
215 	if (unlikely(!pskb_may_pull(skb, th_ofs + sizeof(struct tcphdr))))
216 		return false;
217 
218 	tcp_len = tcp_hdrlen(skb);
219 	if (unlikely(tcp_len < sizeof(struct tcphdr) ||
220 		     skb->len < th_ofs + tcp_len))
221 		return false;
222 
223 	return true;
224 }
225 
226 static bool udphdr_ok(struct sk_buff *skb)
227 {
228 	return pskb_may_pull(skb, skb_transport_offset(skb) +
229 				  sizeof(struct udphdr));
230 }
231 
232 static bool sctphdr_ok(struct sk_buff *skb)
233 {
234 	return pskb_may_pull(skb, skb_transport_offset(skb) +
235 				  sizeof(struct sctphdr));
236 }
237 
238 static bool icmphdr_ok(struct sk_buff *skb)
239 {
240 	return pskb_may_pull(skb, skb_transport_offset(skb) +
241 				  sizeof(struct icmphdr));
242 }
243 
244 /**
245  * get_ipv6_ext_hdrs() - Parses packet and sets IPv6 extension header flags.
246  *
247  * @skb: buffer where extension header data starts in packet
248  * @nh: ipv6 header
249  * @ext_hdrs: flags are stored here
250  *
251  * OFPIEH12_UNREP is set if more than one of a given IPv6 extension header
252  * is unexpectedly encountered. (Two destination options headers may be
253  * expected and would not cause this bit to be set.)
254  *
255  * OFPIEH12_UNSEQ is set if IPv6 extension headers were not in the order
256  * preferred (but not required) by RFC 2460:
257  *
258  * When more than one extension header is used in the same packet, it is
259  * recommended that those headers appear in the following order:
260  *      IPv6 header
261  *      Hop-by-Hop Options header
262  *      Destination Options header
263  *      Routing header
264  *      Fragment header
265  *      Authentication header
266  *      Encapsulating Security Payload header
267  *      Destination Options header
268  *      upper-layer header
269  */
270 static void get_ipv6_ext_hdrs(struct sk_buff *skb, struct ipv6hdr *nh,
271 			      u16 *ext_hdrs)
272 {
273 	u8 next_type = nh->nexthdr;
274 	unsigned int start = skb_network_offset(skb) + sizeof(struct ipv6hdr);
275 	int dest_options_header_count = 0;
276 
277 	*ext_hdrs = 0;
278 
279 	while (ipv6_ext_hdr(next_type)) {
280 		struct ipv6_opt_hdr _hdr, *hp;
281 
282 		switch (next_type) {
283 		case IPPROTO_NONE:
284 			*ext_hdrs |= OFPIEH12_NONEXT;
285 			/* stop parsing */
286 			return;
287 
288 		case IPPROTO_ESP:
289 			if (*ext_hdrs & OFPIEH12_ESP)
290 				*ext_hdrs |= OFPIEH12_UNREP;
291 			if ((*ext_hdrs & ~(OFPIEH12_HOP | OFPIEH12_DEST |
292 					   OFPIEH12_ROUTER | IPPROTO_FRAGMENT |
293 					   OFPIEH12_AUTH | OFPIEH12_UNREP)) ||
294 			    dest_options_header_count >= 2) {
295 				*ext_hdrs |= OFPIEH12_UNSEQ;
296 			}
297 			*ext_hdrs |= OFPIEH12_ESP;
298 			break;
299 
300 		case IPPROTO_AH:
301 			if (*ext_hdrs & OFPIEH12_AUTH)
302 				*ext_hdrs |= OFPIEH12_UNREP;
303 			if ((*ext_hdrs &
304 			     ~(OFPIEH12_HOP | OFPIEH12_DEST | OFPIEH12_ROUTER |
305 			       IPPROTO_FRAGMENT | OFPIEH12_UNREP)) ||
306 			    dest_options_header_count >= 2) {
307 				*ext_hdrs |= OFPIEH12_UNSEQ;
308 			}
309 			*ext_hdrs |= OFPIEH12_AUTH;
310 			break;
311 
312 		case IPPROTO_DSTOPTS:
313 			if (dest_options_header_count == 0) {
314 				if (*ext_hdrs &
315 				    ~(OFPIEH12_HOP | OFPIEH12_UNREP))
316 					*ext_hdrs |= OFPIEH12_UNSEQ;
317 				*ext_hdrs |= OFPIEH12_DEST;
318 			} else if (dest_options_header_count == 1) {
319 				if (*ext_hdrs &
320 				    ~(OFPIEH12_HOP | OFPIEH12_DEST |
321 				      OFPIEH12_ROUTER | OFPIEH12_FRAG |
322 				      OFPIEH12_AUTH | OFPIEH12_ESP |
323 				      OFPIEH12_UNREP)) {
324 					*ext_hdrs |= OFPIEH12_UNSEQ;
325 				}
326 			} else {
327 				*ext_hdrs |= OFPIEH12_UNREP;
328 			}
329 			dest_options_header_count++;
330 			break;
331 
332 		case IPPROTO_FRAGMENT:
333 			if (*ext_hdrs & OFPIEH12_FRAG)
334 				*ext_hdrs |= OFPIEH12_UNREP;
335 			if ((*ext_hdrs & ~(OFPIEH12_HOP |
336 					   OFPIEH12_DEST |
337 					   OFPIEH12_ROUTER |
338 					   OFPIEH12_UNREP)) ||
339 			    dest_options_header_count >= 2) {
340 				*ext_hdrs |= OFPIEH12_UNSEQ;
341 			}
342 			*ext_hdrs |= OFPIEH12_FRAG;
343 			break;
344 
345 		case IPPROTO_ROUTING:
346 			if (*ext_hdrs & OFPIEH12_ROUTER)
347 				*ext_hdrs |= OFPIEH12_UNREP;
348 			if ((*ext_hdrs & ~(OFPIEH12_HOP |
349 					   OFPIEH12_DEST |
350 					   OFPIEH12_UNREP)) ||
351 			    dest_options_header_count >= 2) {
352 				*ext_hdrs |= OFPIEH12_UNSEQ;
353 			}
354 			*ext_hdrs |= OFPIEH12_ROUTER;
355 			break;
356 
357 		case IPPROTO_HOPOPTS:
358 			if (*ext_hdrs & OFPIEH12_HOP)
359 				*ext_hdrs |= OFPIEH12_UNREP;
360 			/* OFPIEH12_HOP is set to 1 if a hop-by-hop IPv6
361 			 * extension header is present as the first
362 			 * extension header in the packet.
363 			 */
364 			if (*ext_hdrs == 0)
365 				*ext_hdrs |= OFPIEH12_HOP;
366 			else
367 				*ext_hdrs |= OFPIEH12_UNSEQ;
368 			break;
369 
370 		default:
371 			return;
372 		}
373 
374 		hp = skb_header_pointer(skb, start, sizeof(_hdr), &_hdr);
375 		if (!hp)
376 			break;
377 		next_type = hp->nexthdr;
378 		start += ipv6_optlen(hp);
379 	}
380 }
381 
382 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
383 {
384 	unsigned short frag_off;
385 	unsigned int payload_ofs = 0;
386 	unsigned int nh_ofs = skb_network_offset(skb);
387 	unsigned int nh_len;
388 	struct ipv6hdr *nh;
389 	int err, nexthdr, flags = 0;
390 
391 	err = check_header(skb, nh_ofs + sizeof(*nh));
392 	if (unlikely(err))
393 		return err;
394 
395 	nh = ipv6_hdr(skb);
396 
397 	get_ipv6_ext_hdrs(skb, nh, &key->ipv6.exthdrs);
398 
399 	key->ip.proto = NEXTHDR_NONE;
400 	key->ip.tos = ipv6_get_dsfield(nh);
401 	key->ip.ttl = nh->hop_limit;
402 	key->ipv6.label = *(__be32 *)nh & htonl(IPV6_FLOWINFO_FLOWLABEL);
403 	key->ipv6.addr.src = nh->saddr;
404 	key->ipv6.addr.dst = nh->daddr;
405 
406 	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
407 	if (flags & IP6_FH_F_FRAG) {
408 		if (frag_off) {
409 			key->ip.frag = OVS_FRAG_TYPE_LATER;
410 			key->ip.proto = NEXTHDR_FRAGMENT;
411 			return 0;
412 		}
413 		key->ip.frag = OVS_FRAG_TYPE_FIRST;
414 	} else {
415 		key->ip.frag = OVS_FRAG_TYPE_NONE;
416 	}
417 
418 	/* Delayed handling of error in ipv6_find_hdr() as it
419 	 * always sets flags and frag_off to a valid value which may be
420 	 * used to set key->ip.frag above.
421 	 */
422 	if (unlikely(nexthdr < 0))
423 		return -EPROTO;
424 
425 	nh_len = payload_ofs - nh_ofs;
426 	skb_set_transport_header(skb, nh_ofs + nh_len);
427 	key->ip.proto = nexthdr;
428 	return nh_len;
429 }
430 
431 static bool icmp6hdr_ok(struct sk_buff *skb)
432 {
433 	return pskb_may_pull(skb, skb_transport_offset(skb) +
434 				  sizeof(struct icmp6hdr));
435 }
436 
437 /**
438  * parse_vlan_tag - Parse vlan tag from vlan header.
439  * @skb: skb containing frame to parse
440  * @key_vh: pointer to parsed vlan tag
441  * @untag_vlan: should the vlan header be removed from the frame
442  *
443  * Return: ERROR on memory error.
444  * %0 if it encounters a non-vlan or incomplete packet.
445  * %1 after successfully parsing vlan tag.
446  */
447 static int parse_vlan_tag(struct sk_buff *skb, struct vlan_head *key_vh,
448 			  bool untag_vlan)
449 {
450 	struct vlan_head *vh = (struct vlan_head *)skb->data;
451 
452 	if (likely(!eth_type_vlan(vh->tpid)))
453 		return 0;
454 
455 	if (unlikely(skb->len < sizeof(struct vlan_head) + sizeof(__be16)))
456 		return 0;
457 
458 	if (unlikely(!pskb_may_pull(skb, sizeof(struct vlan_head) +
459 				 sizeof(__be16))))
460 		return -ENOMEM;
461 
462 	vh = (struct vlan_head *)skb->data;
463 	key_vh->tci = vh->tci | htons(VLAN_CFI_MASK);
464 	key_vh->tpid = vh->tpid;
465 
466 	if (unlikely(untag_vlan)) {
467 		int offset = skb->data - skb_mac_header(skb);
468 		u16 tci;
469 		int err;
470 
471 		__skb_push(skb, offset);
472 		err = __skb_vlan_pop(skb, &tci);
473 		__skb_pull(skb, offset);
474 		if (err)
475 			return err;
476 		__vlan_hwaccel_put_tag(skb, key_vh->tpid, tci);
477 	} else {
478 		__skb_pull(skb, sizeof(struct vlan_head));
479 	}
480 	return 1;
481 }
482 
483 static void clear_vlan(struct sw_flow_key *key)
484 {
485 	key->eth.vlan.tci = 0;
486 	key->eth.vlan.tpid = 0;
487 	key->eth.cvlan.tci = 0;
488 	key->eth.cvlan.tpid = 0;
489 }
490 
491 static int parse_vlan(struct sk_buff *skb, struct sw_flow_key *key)
492 {
493 	int res;
494 
495 	if (skb_vlan_tag_present(skb)) {
496 		key->eth.vlan.tci = htons(skb->vlan_tci) | htons(VLAN_CFI_MASK);
497 		key->eth.vlan.tpid = skb->vlan_proto;
498 	} else {
499 		/* Parse outer vlan tag in the non-accelerated case. */
500 		res = parse_vlan_tag(skb, &key->eth.vlan, true);
501 		if (res <= 0)
502 			return res;
503 	}
504 
505 	/* Parse inner vlan tag. */
506 	res = parse_vlan_tag(skb, &key->eth.cvlan, false);
507 	if (res <= 0)
508 		return res;
509 
510 	return 0;
511 }
512 
513 static __be16 parse_ethertype(struct sk_buff *skb)
514 {
515 	struct llc_snap_hdr {
516 		u8  dsap;  /* Always 0xAA */
517 		u8  ssap;  /* Always 0xAA */
518 		u8  ctrl;
519 		u8  oui[3];
520 		__be16 ethertype;
521 	};
522 	struct llc_snap_hdr *llc;
523 	__be16 proto;
524 
525 	proto = *(__be16 *) skb->data;
526 	__skb_pull(skb, sizeof(__be16));
527 
528 	if (eth_proto_is_802_3(proto))
529 		return proto;
530 
531 	if (skb->len < sizeof(struct llc_snap_hdr))
532 		return htons(ETH_P_802_2);
533 
534 	if (unlikely(!pskb_may_pull(skb, sizeof(struct llc_snap_hdr))))
535 		return htons(0);
536 
537 	llc = (struct llc_snap_hdr *) skb->data;
538 	if (llc->dsap != LLC_SAP_SNAP ||
539 	    llc->ssap != LLC_SAP_SNAP ||
540 	    (llc->oui[0] | llc->oui[1] | llc->oui[2]) != 0)
541 		return htons(ETH_P_802_2);
542 
543 	__skb_pull(skb, sizeof(struct llc_snap_hdr));
544 
545 	if (eth_proto_is_802_3(llc->ethertype))
546 		return llc->ethertype;
547 
548 	return htons(ETH_P_802_2);
549 }
550 
551 static int parse_icmpv6(struct sk_buff *skb, struct sw_flow_key *key,
552 			int nh_len)
553 {
554 	struct icmp6hdr *icmp = icmp6_hdr(skb);
555 
556 	/* The ICMPv6 type and code fields use the 16-bit transport port
557 	 * fields, so we need to store them in 16-bit network byte order.
558 	 */
559 	key->tp.src = htons(icmp->icmp6_type);
560 	key->tp.dst = htons(icmp->icmp6_code);
561 	memset(&key->ipv6.nd, 0, sizeof(key->ipv6.nd));
562 
563 	if (icmp->icmp6_code == 0 &&
564 	    (icmp->icmp6_type == NDISC_NEIGHBOUR_SOLICITATION ||
565 	     icmp->icmp6_type == NDISC_NEIGHBOUR_ADVERTISEMENT)) {
566 		int icmp_len = skb->len - skb_transport_offset(skb);
567 		struct nd_msg *nd;
568 		int offset;
569 
570 		/* In order to process neighbor discovery options, we need the
571 		 * entire packet.
572 		 */
573 		if (unlikely(icmp_len < sizeof(*nd)))
574 			return 0;
575 
576 		if (unlikely(skb_linearize(skb)))
577 			return -ENOMEM;
578 
579 		nd = (struct nd_msg *)skb_transport_header(skb);
580 		key->ipv6.nd.target = nd->target;
581 
582 		icmp_len -= sizeof(*nd);
583 		offset = 0;
584 		while (icmp_len >= 8) {
585 			struct nd_opt_hdr *nd_opt =
586 				 (struct nd_opt_hdr *)(nd->opt + offset);
587 			int opt_len = nd_opt->nd_opt_len * 8;
588 
589 			if (unlikely(!opt_len || opt_len > icmp_len))
590 				return 0;
591 
592 			/* Store the link layer address if the appropriate
593 			 * option is provided.  It is considered an error if
594 			 * the same link layer option is specified twice.
595 			 */
596 			if (nd_opt->nd_opt_type == ND_OPT_SOURCE_LL_ADDR
597 			    && opt_len == 8) {
598 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.sll)))
599 					goto invalid;
600 				ether_addr_copy(key->ipv6.nd.sll,
601 						&nd->opt[offset+sizeof(*nd_opt)]);
602 			} else if (nd_opt->nd_opt_type == ND_OPT_TARGET_LL_ADDR
603 				   && opt_len == 8) {
604 				if (unlikely(!is_zero_ether_addr(key->ipv6.nd.tll)))
605 					goto invalid;
606 				ether_addr_copy(key->ipv6.nd.tll,
607 						&nd->opt[offset+sizeof(*nd_opt)]);
608 			}
609 
610 			icmp_len -= opt_len;
611 			offset += opt_len;
612 		}
613 	}
614 
615 	return 0;
616 
617 invalid:
618 	memset(&key->ipv6.nd.target, 0, sizeof(key->ipv6.nd.target));
619 	memset(key->ipv6.nd.sll, 0, sizeof(key->ipv6.nd.sll));
620 	memset(key->ipv6.nd.tll, 0, sizeof(key->ipv6.nd.tll));
621 
622 	return 0;
623 }
624 
625 static int parse_nsh(struct sk_buff *skb, struct sw_flow_key *key)
626 {
627 	struct nshhdr *nh;
628 	unsigned int nh_ofs = skb_network_offset(skb);
629 	u8 version, length;
630 	int err;
631 
632 	err = check_header(skb, nh_ofs + NSH_BASE_HDR_LEN);
633 	if (unlikely(err))
634 		return err;
635 
636 	nh = nsh_hdr(skb);
637 	version = nsh_get_ver(nh);
638 	length = nsh_hdr_len(nh);
639 
640 	if (version != 0)
641 		return -EINVAL;
642 
643 	err = check_header(skb, nh_ofs + length);
644 	if (unlikely(err))
645 		return err;
646 
647 	nh = nsh_hdr(skb);
648 	key->nsh.base.flags = nsh_get_flags(nh);
649 	key->nsh.base.ttl = nsh_get_ttl(nh);
650 	key->nsh.base.mdtype = nh->mdtype;
651 	key->nsh.base.np = nh->np;
652 	key->nsh.base.path_hdr = nh->path_hdr;
653 	switch (key->nsh.base.mdtype) {
654 	case NSH_M_TYPE1:
655 		if (length != NSH_M_TYPE1_LEN)
656 			return -EINVAL;
657 		memcpy(key->nsh.context, nh->md1.context,
658 		       sizeof(nh->md1));
659 		break;
660 	case NSH_M_TYPE2:
661 		memset(key->nsh.context, 0,
662 		       sizeof(nh->md1));
663 		break;
664 	default:
665 		return -EINVAL;
666 	}
667 
668 	return 0;
669 }
670 
671 /**
672  * key_extract_l3l4 - extracts L3/L4 header information.
673  * @skb: sk_buff that contains the frame, with skb->data pointing to the
674  *       L3 header
675  * @key: output flow key
676  *
677  * Return: %0 if successful, otherwise a negative errno value.
678  */
679 static int key_extract_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
680 {
681 	int error;
682 
683 	/* Network layer. */
684 	if (key->eth.type == htons(ETH_P_IP)) {
685 		struct iphdr *nh;
686 		__be16 offset;
687 
688 		error = check_iphdr(skb);
689 		if (unlikely(error)) {
690 			memset(&key->ip, 0, sizeof(key->ip));
691 			memset(&key->ipv4, 0, sizeof(key->ipv4));
692 			if (error == -EINVAL) {
693 				skb->transport_header = skb->network_header;
694 				error = 0;
695 			}
696 			return error;
697 		}
698 
699 		nh = ip_hdr(skb);
700 		key->ipv4.addr.src = nh->saddr;
701 		key->ipv4.addr.dst = nh->daddr;
702 
703 		key->ip.proto = nh->protocol;
704 		key->ip.tos = nh->tos;
705 		key->ip.ttl = nh->ttl;
706 
707 		offset = nh->frag_off & htons(IP_OFFSET);
708 		if (offset) {
709 			key->ip.frag = OVS_FRAG_TYPE_LATER;
710 			memset(&key->tp, 0, sizeof(key->tp));
711 			return 0;
712 		}
713 		if (nh->frag_off & htons(IP_MF) ||
714 			skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
715 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
716 		else
717 			key->ip.frag = OVS_FRAG_TYPE_NONE;
718 
719 		/* Transport layer. */
720 		if (key->ip.proto == IPPROTO_TCP) {
721 			if (tcphdr_ok(skb)) {
722 				struct tcphdr *tcp = tcp_hdr(skb);
723 				key->tp.src = tcp->source;
724 				key->tp.dst = tcp->dest;
725 				key->tp.flags = TCP_FLAGS_BE16(tcp);
726 			} else {
727 				memset(&key->tp, 0, sizeof(key->tp));
728 			}
729 
730 		} else if (key->ip.proto == IPPROTO_UDP) {
731 			if (udphdr_ok(skb)) {
732 				struct udphdr *udp = udp_hdr(skb);
733 				key->tp.src = udp->source;
734 				key->tp.dst = udp->dest;
735 			} else {
736 				memset(&key->tp, 0, sizeof(key->tp));
737 			}
738 		} else if (key->ip.proto == IPPROTO_SCTP) {
739 			if (sctphdr_ok(skb)) {
740 				struct sctphdr *sctp = sctp_hdr(skb);
741 				key->tp.src = sctp->source;
742 				key->tp.dst = sctp->dest;
743 			} else {
744 				memset(&key->tp, 0, sizeof(key->tp));
745 			}
746 		} else if (key->ip.proto == IPPROTO_ICMP) {
747 			if (icmphdr_ok(skb)) {
748 				struct icmphdr *icmp = icmp_hdr(skb);
749 				/* The ICMP type and code fields use the 16-bit
750 				 * transport port fields, so we need to store
751 				 * them in 16-bit network byte order. */
752 				key->tp.src = htons(icmp->type);
753 				key->tp.dst = htons(icmp->code);
754 			} else {
755 				memset(&key->tp, 0, sizeof(key->tp));
756 			}
757 		}
758 
759 	} else if (key->eth.type == htons(ETH_P_ARP) ||
760 		   key->eth.type == htons(ETH_P_RARP)) {
761 		struct arp_eth_header *arp;
762 		bool arp_available = arphdr_ok(skb);
763 
764 		arp = (struct arp_eth_header *)skb_network_header(skb);
765 
766 		if (arp_available &&
767 		    arp->ar_hrd == htons(ARPHRD_ETHER) &&
768 		    arp->ar_pro == htons(ETH_P_IP) &&
769 		    arp->ar_hln == ETH_ALEN &&
770 		    arp->ar_pln == 4) {
771 
772 			/* We only match on the lower 8 bits of the opcode. */
773 			if (ntohs(arp->ar_op) <= 0xff)
774 				key->ip.proto = ntohs(arp->ar_op);
775 			else
776 				key->ip.proto = 0;
777 
778 			memcpy(&key->ipv4.addr.src, arp->ar_sip, sizeof(key->ipv4.addr.src));
779 			memcpy(&key->ipv4.addr.dst, arp->ar_tip, sizeof(key->ipv4.addr.dst));
780 			ether_addr_copy(key->ipv4.arp.sha, arp->ar_sha);
781 			ether_addr_copy(key->ipv4.arp.tha, arp->ar_tha);
782 		} else {
783 			memset(&key->ip, 0, sizeof(key->ip));
784 			memset(&key->ipv4, 0, sizeof(key->ipv4));
785 		}
786 	} else if (eth_p_mpls(key->eth.type)) {
787 		u8 label_count = 1;
788 
789 		memset(&key->mpls, 0, sizeof(key->mpls));
790 		skb_set_inner_network_header(skb, skb->mac_len);
791 		while (1) {
792 			__be32 lse;
793 
794 			error = check_header(skb, skb->mac_len +
795 					     label_count * MPLS_HLEN);
796 			if (unlikely(error))
797 				return 0;
798 
799 			memcpy(&lse, skb_inner_network_header(skb), MPLS_HLEN);
800 
801 			if (label_count <= MPLS_LABEL_DEPTH)
802 				memcpy(&key->mpls.lse[label_count - 1], &lse,
803 				       MPLS_HLEN);
804 
805 			skb_set_inner_network_header(skb, skb->mac_len +
806 						     label_count * MPLS_HLEN);
807 			if (lse & htonl(MPLS_LS_S_MASK))
808 				break;
809 
810 			label_count++;
811 		}
812 		if (label_count > MPLS_LABEL_DEPTH)
813 			label_count = MPLS_LABEL_DEPTH;
814 
815 		key->mpls.num_labels_mask = GENMASK(label_count - 1, 0);
816 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
817 		int nh_len;             /* IPv6 Header + Extensions */
818 
819 		nh_len = parse_ipv6hdr(skb, key);
820 		if (unlikely(nh_len < 0)) {
821 			switch (nh_len) {
822 			case -EINVAL:
823 				memset(&key->ip, 0, sizeof(key->ip));
824 				memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr));
825 				fallthrough;
826 			case -EPROTO:
827 				skb->transport_header = skb->network_header;
828 				error = 0;
829 				break;
830 			default:
831 				error = nh_len;
832 			}
833 			return error;
834 		}
835 
836 		if (key->ip.frag == OVS_FRAG_TYPE_LATER) {
837 			memset(&key->tp, 0, sizeof(key->tp));
838 			return 0;
839 		}
840 		if (skb_shinfo(skb)->gso_type & SKB_GSO_UDP)
841 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
842 
843 		/* Transport layer. */
844 		if (key->ip.proto == NEXTHDR_TCP) {
845 			if (tcphdr_ok(skb)) {
846 				struct tcphdr *tcp = tcp_hdr(skb);
847 				key->tp.src = tcp->source;
848 				key->tp.dst = tcp->dest;
849 				key->tp.flags = TCP_FLAGS_BE16(tcp);
850 			} else {
851 				memset(&key->tp, 0, sizeof(key->tp));
852 			}
853 		} else if (key->ip.proto == NEXTHDR_UDP) {
854 			if (udphdr_ok(skb)) {
855 				struct udphdr *udp = udp_hdr(skb);
856 				key->tp.src = udp->source;
857 				key->tp.dst = udp->dest;
858 			} else {
859 				memset(&key->tp, 0, sizeof(key->tp));
860 			}
861 		} else if (key->ip.proto == NEXTHDR_SCTP) {
862 			if (sctphdr_ok(skb)) {
863 				struct sctphdr *sctp = sctp_hdr(skb);
864 				key->tp.src = sctp->source;
865 				key->tp.dst = sctp->dest;
866 			} else {
867 				memset(&key->tp, 0, sizeof(key->tp));
868 			}
869 		} else if (key->ip.proto == NEXTHDR_ICMP) {
870 			if (icmp6hdr_ok(skb)) {
871 				error = parse_icmpv6(skb, key, nh_len);
872 				if (error)
873 					return error;
874 			} else {
875 				memset(&key->tp, 0, sizeof(key->tp));
876 			}
877 		}
878 	} else if (key->eth.type == htons(ETH_P_NSH)) {
879 		error = parse_nsh(skb, key);
880 		if (error)
881 			return error;
882 	}
883 	return 0;
884 }
885 
886 /**
887  * key_extract - extracts a flow key from an Ethernet frame.
888  * @skb: sk_buff that contains the frame, with skb->data pointing to the
889  * Ethernet header
890  * @key: output flow key
891  *
892  * The caller must ensure that skb->len >= ETH_HLEN.
893  *
894  * Initializes @skb header fields as follows:
895  *
896  *    - skb->mac_header: the L2 header.
897  *
898  *    - skb->network_header: just past the L2 header, or just past the
899  *      VLAN header, to the first byte of the L2 payload.
900  *
901  *    - skb->transport_header: If key->eth.type is ETH_P_IP or ETH_P_IPV6
902  *      on output, then just past the IP header, if one is present and
903  *      of a correct length, otherwise the same as skb->network_header.
904  *      For other key->eth.type values it is left untouched.
905  *
906  *    - skb->protocol: the type of the data starting at skb->network_header.
907  *      Equals to key->eth.type.
908  *
909  * Return: %0 if successful, otherwise a negative errno value.
910  */
911 static int key_extract(struct sk_buff *skb, struct sw_flow_key *key)
912 {
913 	struct ethhdr *eth;
914 
915 	/* Flags are always used as part of stats */
916 	key->tp.flags = 0;
917 
918 	skb_reset_mac_header(skb);
919 
920 	/* Link layer. */
921 	clear_vlan(key);
922 	if (ovs_key_mac_proto(key) == MAC_PROTO_NONE) {
923 		if (unlikely(eth_type_vlan(skb->protocol)))
924 			return -EINVAL;
925 
926 		skb_reset_network_header(skb);
927 		key->eth.type = skb->protocol;
928 	} else {
929 		eth = eth_hdr(skb);
930 		ether_addr_copy(key->eth.src, eth->h_source);
931 		ether_addr_copy(key->eth.dst, eth->h_dest);
932 
933 		__skb_pull(skb, 2 * ETH_ALEN);
934 		/* We are going to push all headers that we pull, so no need to
935 		 * update skb->csum here.
936 		 */
937 
938 		if (unlikely(parse_vlan(skb, key)))
939 			return -ENOMEM;
940 
941 		key->eth.type = parse_ethertype(skb);
942 		if (unlikely(key->eth.type == htons(0)))
943 			return -ENOMEM;
944 
945 		/* Multiple tagged packets need to retain TPID to satisfy
946 		 * skb_vlan_pop(), which will later shift the ethertype into
947 		 * skb->protocol.
948 		 */
949 		if (key->eth.cvlan.tci & htons(VLAN_CFI_MASK))
950 			skb->protocol = key->eth.cvlan.tpid;
951 		else
952 			skb->protocol = key->eth.type;
953 
954 		skb_reset_network_header(skb);
955 		__skb_push(skb, skb->data - skb_mac_header(skb));
956 	}
957 
958 	skb_reset_mac_len(skb);
959 
960 	/* Fill out L3/L4 key info, if any */
961 	return key_extract_l3l4(skb, key);
962 }
963 
964 /* In the case of conntrack fragment handling it expects L3 headers,
965  * add a helper.
966  */
967 int ovs_flow_key_update_l3l4(struct sk_buff *skb, struct sw_flow_key *key)
968 {
969 	return key_extract_l3l4(skb, key);
970 }
971 
972 int ovs_flow_key_update(struct sk_buff *skb, struct sw_flow_key *key)
973 {
974 	int res;
975 
976 	res = key_extract(skb, key);
977 	if (!res)
978 		key->mac_proto &= ~SW_FLOW_KEY_INVALID;
979 
980 	return res;
981 }
982 
983 static int key_extract_mac_proto(struct sk_buff *skb)
984 {
985 	switch (skb->dev->type) {
986 	case ARPHRD_ETHER:
987 		return MAC_PROTO_ETHERNET;
988 	case ARPHRD_NONE:
989 		if (skb->protocol == htons(ETH_P_TEB))
990 			return MAC_PROTO_ETHERNET;
991 		return MAC_PROTO_NONE;
992 	}
993 	WARN_ON_ONCE(1);
994 	return -EINVAL;
995 }
996 
997 int ovs_flow_key_extract(const struct ip_tunnel_info *tun_info,
998 			 struct sk_buff *skb, struct sw_flow_key *key)
999 {
1000 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1001 	struct tc_skb_ext *tc_ext;
1002 #endif
1003 	bool post_ct = false, post_ct_snat = false, post_ct_dnat = false;
1004 	int res, err;
1005 	u16 zone = 0;
1006 
1007 	/* Extract metadata from packet. */
1008 	if (tun_info) {
1009 		key->tun_proto = ip_tunnel_info_af(tun_info);
1010 		memcpy(&key->tun_key, &tun_info->key, sizeof(key->tun_key));
1011 
1012 		if (tun_info->options_len) {
1013 			BUILD_BUG_ON((1 << (sizeof(tun_info->options_len) *
1014 						   8)) - 1
1015 					> sizeof(key->tun_opts));
1016 
1017 			ip_tunnel_info_opts_get(TUN_METADATA_OPTS(key, tun_info->options_len),
1018 						tun_info);
1019 			key->tun_opts_len = tun_info->options_len;
1020 		} else {
1021 			key->tun_opts_len = 0;
1022 		}
1023 	} else  {
1024 		key->tun_proto = 0;
1025 		key->tun_opts_len = 0;
1026 		memset(&key->tun_key, 0, sizeof(key->tun_key));
1027 	}
1028 
1029 	key->phy.priority = skb->priority;
1030 	key->phy.in_port = OVS_CB(skb)->input_vport->port_no;
1031 	key->phy.skb_mark = skb->mark;
1032 	key->ovs_flow_hash = 0;
1033 	res = key_extract_mac_proto(skb);
1034 	if (res < 0)
1035 		return res;
1036 	key->mac_proto = res;
1037 
1038 #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
1039 	if (tc_skb_ext_tc_enabled()) {
1040 		tc_ext = skb_ext_find(skb, TC_SKB_EXT);
1041 		key->recirc_id = tc_ext ? tc_ext->chain : 0;
1042 		OVS_CB(skb)->mru = tc_ext ? tc_ext->mru : 0;
1043 		post_ct = tc_ext ? tc_ext->post_ct : false;
1044 		post_ct_snat = post_ct ? tc_ext->post_ct_snat : false;
1045 		post_ct_dnat = post_ct ? tc_ext->post_ct_dnat : false;
1046 		zone = post_ct ? tc_ext->zone : 0;
1047 	} else {
1048 		key->recirc_id = 0;
1049 	}
1050 #else
1051 	key->recirc_id = 0;
1052 #endif
1053 
1054 	err = key_extract(skb, key);
1055 	if (!err) {
1056 		ovs_ct_fill_key(skb, key, post_ct);   /* Must be after key_extract(). */
1057 		if (post_ct) {
1058 			if (!skb_get_nfct(skb)) {
1059 				key->ct_zone = zone;
1060 			} else {
1061 				if (!post_ct_dnat)
1062 					key->ct_state &= ~OVS_CS_F_DST_NAT;
1063 				if (!post_ct_snat)
1064 					key->ct_state &= ~OVS_CS_F_SRC_NAT;
1065 			}
1066 		}
1067 	}
1068 	return err;
1069 }
1070 
1071 int ovs_flow_key_extract_userspace(struct net *net, const struct nlattr *attr,
1072 				   struct sk_buff *skb,
1073 				   struct sw_flow_key *key, bool log)
1074 {
1075 	const struct nlattr *a[OVS_KEY_ATTR_MAX + 1];
1076 	u64 attrs = 0;
1077 	int err;
1078 
1079 	err = parse_flow_nlattrs(attr, a, &attrs, log);
1080 	if (err)
1081 		return -EINVAL;
1082 
1083 	/* Extract metadata from netlink attributes. */
1084 	err = ovs_nla_get_flow_metadata(net, a, attrs, key, log);
1085 	if (err)
1086 		return err;
1087 
1088 	/* key_extract assumes that skb->protocol is set-up for
1089 	 * layer 3 packets which is the case for other callers,
1090 	 * in particular packets received from the network stack.
1091 	 * Here the correct value can be set from the metadata
1092 	 * extracted above.
1093 	 * For L2 packet key eth type would be zero. skb protocol
1094 	 * would be set to correct value later during key-extact.
1095 	 */
1096 
1097 	skb->protocol = key->eth.type;
1098 	err = key_extract(skb, key);
1099 	if (err)
1100 		return err;
1101 
1102 	/* Check that we have conntrack original direction tuple metadata only
1103 	 * for packets for which it makes sense.  Otherwise the key may be
1104 	 * corrupted due to overlapping key fields.
1105 	 */
1106 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4) &&
1107 	    key->eth.type != htons(ETH_P_IP))
1108 		return -EINVAL;
1109 	if (attrs & (1 << OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6) &&
1110 	    (key->eth.type != htons(ETH_P_IPV6) ||
1111 	     sw_flow_key_is_nd(key)))
1112 		return -EINVAL;
1113 
1114 	return 0;
1115 }
1116