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
ovs_flow_used_time(unsigned long flow_jiffies)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
ovs_flow_stats_update(struct sw_flow * flow,__be16 tcp_flags,const struct sk_buff * skb)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. */
ovs_flow_stats_get(const struct sw_flow * flow,struct ovs_flow_stats * ovs_stats,unsigned long * used,__be16 * tcp_flags)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. */
ovs_flow_stats_clear(struct sw_flow * flow)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
check_header(struct sk_buff * skb,int len)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
arphdr_ok(struct sk_buff * skb)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
check_iphdr(struct sk_buff * skb)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
tcphdr_ok(struct sk_buff * skb)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
udphdr_ok(struct sk_buff * skb)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
sctphdr_ok(struct sk_buff * skb)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
icmphdr_ok(struct sk_buff * skb)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 */
get_ipv6_ext_hdrs(struct sk_buff * skb,struct ipv6hdr * nh,u16 * ext_hdrs)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
parse_ipv6hdr(struct sk_buff * skb,struct sw_flow_key * key)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
icmp6hdr_ok(struct sk_buff * skb)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 */
parse_vlan_tag(struct sk_buff * skb,struct vlan_head * key_vh,bool untag_vlan)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
clear_vlan(struct sw_flow_key * key)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
parse_vlan(struct sk_buff * skb,struct sw_flow_key * key)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
parse_ethertype(struct sk_buff * skb)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
parse_icmpv6(struct sk_buff * skb,struct sw_flow_key * key,int nh_len)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
parse_nsh(struct sk_buff * skb,struct sw_flow_key * key)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 */
key_extract_l3l4(struct sk_buff * skb,struct sw_flow_key * key)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 */
key_extract(struct sk_buff * skb,struct sw_flow_key * key)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 */
ovs_flow_key_update_l3l4(struct sk_buff * skb,struct sw_flow_key * key)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
ovs_flow_key_update(struct sk_buff * skb,struct sw_flow_key * key)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
key_extract_mac_proto(struct sk_buff * skb)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
ovs_flow_key_extract(const struct ip_tunnel_info * tun_info,struct sk_buff * skb,struct sw_flow_key * key)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
ovs_flow_key_extract_userspace(struct net * net,const struct nlattr * attr,struct sk_buff * skb,struct sw_flow_key * key,bool log)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