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Merge tag 'for-linus-20190112' of git://git.kernel.dk/linux-block
[mirror_ubuntu-eoan-kernel.git] / net / core / flow_dissector.c
1 #include <linux/kernel.h>
2 #include <linux/skbuff.h>
3 #include <linux/export.h>
4 #include <linux/ip.h>
5 #include <linux/ipv6.h>
6 #include <linux/if_vlan.h>
7 #include <net/dsa.h>
8 #include <net/dst_metadata.h>
9 #include <net/ip.h>
10 #include <net/ipv6.h>
11 #include <net/gre.h>
12 #include <net/pptp.h>
13 #include <net/tipc.h>
14 #include <linux/igmp.h>
15 #include <linux/icmp.h>
16 #include <linux/sctp.h>
17 #include <linux/dccp.h>
18 #include <linux/if_tunnel.h>
19 #include <linux/if_pppox.h>
20 #include <linux/ppp_defs.h>
21 #include <linux/stddef.h>
22 #include <linux/if_ether.h>
23 #include <linux/mpls.h>
24 #include <linux/tcp.h>
25 #include <net/flow_dissector.h>
26 #include <scsi/fc/fc_fcoe.h>
27 #include <uapi/linux/batadv_packet.h>
28 #include <linux/bpf.h>
29
30 static DEFINE_MUTEX(flow_dissector_mutex);
31
32 static void dissector_set_key(struct flow_dissector *flow_dissector,
33 enum flow_dissector_key_id key_id)
34 {
35 flow_dissector->used_keys |= (1 << key_id);
36 }
37
38 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
39 const struct flow_dissector_key *key,
40 unsigned int key_count)
41 {
42 unsigned int i;
43
44 memset(flow_dissector, 0, sizeof(*flow_dissector));
45
46 for (i = 0; i < key_count; i++, key++) {
47 /* User should make sure that every key target offset is withing
48 * boundaries of unsigned short.
49 */
50 BUG_ON(key->offset > USHRT_MAX);
51 BUG_ON(dissector_uses_key(flow_dissector,
52 key->key_id));
53
54 dissector_set_key(flow_dissector, key->key_id);
55 flow_dissector->offset[key->key_id] = key->offset;
56 }
57
58 /* Ensure that the dissector always includes control and basic key.
59 * That way we are able to avoid handling lack of these in fast path.
60 */
61 BUG_ON(!dissector_uses_key(flow_dissector,
62 FLOW_DISSECTOR_KEY_CONTROL));
63 BUG_ON(!dissector_uses_key(flow_dissector,
64 FLOW_DISSECTOR_KEY_BASIC));
65 }
66 EXPORT_SYMBOL(skb_flow_dissector_init);
67
68 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
69 struct bpf_prog *prog)
70 {
71 struct bpf_prog *attached;
72 struct net *net;
73
74 net = current->nsproxy->net_ns;
75 mutex_lock(&flow_dissector_mutex);
76 attached = rcu_dereference_protected(net->flow_dissector_prog,
77 lockdep_is_held(&flow_dissector_mutex));
78 if (attached) {
79 /* Only one BPF program can be attached at a time */
80 mutex_unlock(&flow_dissector_mutex);
81 return -EEXIST;
82 }
83 rcu_assign_pointer(net->flow_dissector_prog, prog);
84 mutex_unlock(&flow_dissector_mutex);
85 return 0;
86 }
87
88 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
89 {
90 struct bpf_prog *attached;
91 struct net *net;
92
93 net = current->nsproxy->net_ns;
94 mutex_lock(&flow_dissector_mutex);
95 attached = rcu_dereference_protected(net->flow_dissector_prog,
96 lockdep_is_held(&flow_dissector_mutex));
97 if (!attached) {
98 mutex_unlock(&flow_dissector_mutex);
99 return -ENOENT;
100 }
101 bpf_prog_put(attached);
102 RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
103 mutex_unlock(&flow_dissector_mutex);
104 return 0;
105 }
106 /**
107 * skb_flow_get_be16 - extract be16 entity
108 * @skb: sk_buff to extract from
109 * @poff: offset to extract at
110 * @data: raw buffer pointer to the packet
111 * @hlen: packet header length
112 *
113 * The function will try to retrieve a be32 entity at
114 * offset poff
115 */
116 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
117 void *data, int hlen)
118 {
119 __be16 *u, _u;
120
121 u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
122 if (u)
123 return *u;
124
125 return 0;
126 }
127
128 /**
129 * __skb_flow_get_ports - extract the upper layer ports and return them
130 * @skb: sk_buff to extract the ports from
131 * @thoff: transport header offset
132 * @ip_proto: protocol for which to get port offset
133 * @data: raw buffer pointer to the packet, if NULL use skb->data
134 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
135 *
136 * The function will try to retrieve the ports at offset thoff + poff where poff
137 * is the protocol port offset returned from proto_ports_offset
138 */
139 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
140 void *data, int hlen)
141 {
142 int poff = proto_ports_offset(ip_proto);
143
144 if (!data) {
145 data = skb->data;
146 hlen = skb_headlen(skb);
147 }
148
149 if (poff >= 0) {
150 __be32 *ports, _ports;
151
152 ports = __skb_header_pointer(skb, thoff + poff,
153 sizeof(_ports), data, hlen, &_ports);
154 if (ports)
155 return *ports;
156 }
157
158 return 0;
159 }
160 EXPORT_SYMBOL(__skb_flow_get_ports);
161
162 static void
163 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
164 struct flow_dissector *flow_dissector,
165 void *target_container)
166 {
167 struct flow_dissector_key_control *ctrl;
168
169 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
170 return;
171
172 ctrl = skb_flow_dissector_target(flow_dissector,
173 FLOW_DISSECTOR_KEY_ENC_CONTROL,
174 target_container);
175 ctrl->addr_type = type;
176 }
177
178 void
179 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
180 struct flow_dissector *flow_dissector,
181 void *target_container)
182 {
183 struct ip_tunnel_info *info;
184 struct ip_tunnel_key *key;
185
186 /* A quick check to see if there might be something to do. */
187 if (!dissector_uses_key(flow_dissector,
188 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
189 !dissector_uses_key(flow_dissector,
190 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
191 !dissector_uses_key(flow_dissector,
192 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
193 !dissector_uses_key(flow_dissector,
194 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
195 !dissector_uses_key(flow_dissector,
196 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
197 !dissector_uses_key(flow_dissector,
198 FLOW_DISSECTOR_KEY_ENC_IP) &&
199 !dissector_uses_key(flow_dissector,
200 FLOW_DISSECTOR_KEY_ENC_OPTS))
201 return;
202
203 info = skb_tunnel_info(skb);
204 if (!info)
205 return;
206
207 key = &info->key;
208
209 switch (ip_tunnel_info_af(info)) {
210 case AF_INET:
211 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
212 flow_dissector,
213 target_container);
214 if (dissector_uses_key(flow_dissector,
215 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
216 struct flow_dissector_key_ipv4_addrs *ipv4;
217
218 ipv4 = skb_flow_dissector_target(flow_dissector,
219 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
220 target_container);
221 ipv4->src = key->u.ipv4.src;
222 ipv4->dst = key->u.ipv4.dst;
223 }
224 break;
225 case AF_INET6:
226 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
227 flow_dissector,
228 target_container);
229 if (dissector_uses_key(flow_dissector,
230 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
231 struct flow_dissector_key_ipv6_addrs *ipv6;
232
233 ipv6 = skb_flow_dissector_target(flow_dissector,
234 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
235 target_container);
236 ipv6->src = key->u.ipv6.src;
237 ipv6->dst = key->u.ipv6.dst;
238 }
239 break;
240 }
241
242 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
243 struct flow_dissector_key_keyid *keyid;
244
245 keyid = skb_flow_dissector_target(flow_dissector,
246 FLOW_DISSECTOR_KEY_ENC_KEYID,
247 target_container);
248 keyid->keyid = tunnel_id_to_key32(key->tun_id);
249 }
250
251 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
252 struct flow_dissector_key_ports *tp;
253
254 tp = skb_flow_dissector_target(flow_dissector,
255 FLOW_DISSECTOR_KEY_ENC_PORTS,
256 target_container);
257 tp->src = key->tp_src;
258 tp->dst = key->tp_dst;
259 }
260
261 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
262 struct flow_dissector_key_ip *ip;
263
264 ip = skb_flow_dissector_target(flow_dissector,
265 FLOW_DISSECTOR_KEY_ENC_IP,
266 target_container);
267 ip->tos = key->tos;
268 ip->ttl = key->ttl;
269 }
270
271 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
272 struct flow_dissector_key_enc_opts *enc_opt;
273
274 enc_opt = skb_flow_dissector_target(flow_dissector,
275 FLOW_DISSECTOR_KEY_ENC_OPTS,
276 target_container);
277
278 if (info->options_len) {
279 enc_opt->len = info->options_len;
280 ip_tunnel_info_opts_get(enc_opt->data, info);
281 enc_opt->dst_opt_type = info->key.tun_flags &
282 TUNNEL_OPTIONS_PRESENT;
283 }
284 }
285 }
286 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
287
288 static enum flow_dissect_ret
289 __skb_flow_dissect_mpls(const struct sk_buff *skb,
290 struct flow_dissector *flow_dissector,
291 void *target_container, void *data, int nhoff, int hlen)
292 {
293 struct flow_dissector_key_keyid *key_keyid;
294 struct mpls_label *hdr, _hdr[2];
295 u32 entry, label;
296
297 if (!dissector_uses_key(flow_dissector,
298 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
299 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
300 return FLOW_DISSECT_RET_OUT_GOOD;
301
302 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
303 hlen, &_hdr);
304 if (!hdr)
305 return FLOW_DISSECT_RET_OUT_BAD;
306
307 entry = ntohl(hdr[0].entry);
308 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
309
310 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
311 struct flow_dissector_key_mpls *key_mpls;
312
313 key_mpls = skb_flow_dissector_target(flow_dissector,
314 FLOW_DISSECTOR_KEY_MPLS,
315 target_container);
316 key_mpls->mpls_label = label;
317 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
318 >> MPLS_LS_TTL_SHIFT;
319 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
320 >> MPLS_LS_TC_SHIFT;
321 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
322 >> MPLS_LS_S_SHIFT;
323 }
324
325 if (label == MPLS_LABEL_ENTROPY) {
326 key_keyid = skb_flow_dissector_target(flow_dissector,
327 FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
328 target_container);
329 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
330 }
331 return FLOW_DISSECT_RET_OUT_GOOD;
332 }
333
334 static enum flow_dissect_ret
335 __skb_flow_dissect_arp(const struct sk_buff *skb,
336 struct flow_dissector *flow_dissector,
337 void *target_container, void *data, int nhoff, int hlen)
338 {
339 struct flow_dissector_key_arp *key_arp;
340 struct {
341 unsigned char ar_sha[ETH_ALEN];
342 unsigned char ar_sip[4];
343 unsigned char ar_tha[ETH_ALEN];
344 unsigned char ar_tip[4];
345 } *arp_eth, _arp_eth;
346 const struct arphdr *arp;
347 struct arphdr _arp;
348
349 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
350 return FLOW_DISSECT_RET_OUT_GOOD;
351
352 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
353 hlen, &_arp);
354 if (!arp)
355 return FLOW_DISSECT_RET_OUT_BAD;
356
357 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
358 arp->ar_pro != htons(ETH_P_IP) ||
359 arp->ar_hln != ETH_ALEN ||
360 arp->ar_pln != 4 ||
361 (arp->ar_op != htons(ARPOP_REPLY) &&
362 arp->ar_op != htons(ARPOP_REQUEST)))
363 return FLOW_DISSECT_RET_OUT_BAD;
364
365 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
366 sizeof(_arp_eth), data,
367 hlen, &_arp_eth);
368 if (!arp_eth)
369 return FLOW_DISSECT_RET_OUT_BAD;
370
371 key_arp = skb_flow_dissector_target(flow_dissector,
372 FLOW_DISSECTOR_KEY_ARP,
373 target_container);
374
375 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
376 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
377
378 /* Only store the lower byte of the opcode;
379 * this covers ARPOP_REPLY and ARPOP_REQUEST.
380 */
381 key_arp->op = ntohs(arp->ar_op) & 0xff;
382
383 ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
384 ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
385
386 return FLOW_DISSECT_RET_OUT_GOOD;
387 }
388
389 static enum flow_dissect_ret
390 __skb_flow_dissect_gre(const struct sk_buff *skb,
391 struct flow_dissector_key_control *key_control,
392 struct flow_dissector *flow_dissector,
393 void *target_container, void *data,
394 __be16 *p_proto, int *p_nhoff, int *p_hlen,
395 unsigned int flags)
396 {
397 struct flow_dissector_key_keyid *key_keyid;
398 struct gre_base_hdr *hdr, _hdr;
399 int offset = 0;
400 u16 gre_ver;
401
402 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
403 data, *p_hlen, &_hdr);
404 if (!hdr)
405 return FLOW_DISSECT_RET_OUT_BAD;
406
407 /* Only look inside GRE without routing */
408 if (hdr->flags & GRE_ROUTING)
409 return FLOW_DISSECT_RET_OUT_GOOD;
410
411 /* Only look inside GRE for version 0 and 1 */
412 gre_ver = ntohs(hdr->flags & GRE_VERSION);
413 if (gre_ver > 1)
414 return FLOW_DISSECT_RET_OUT_GOOD;
415
416 *p_proto = hdr->protocol;
417 if (gre_ver) {
418 /* Version1 must be PPTP, and check the flags */
419 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
420 return FLOW_DISSECT_RET_OUT_GOOD;
421 }
422
423 offset += sizeof(struct gre_base_hdr);
424
425 if (hdr->flags & GRE_CSUM)
426 offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
427 FIELD_SIZEOF(struct gre_full_hdr, reserved1);
428
429 if (hdr->flags & GRE_KEY) {
430 const __be32 *keyid;
431 __be32 _keyid;
432
433 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
434 sizeof(_keyid),
435 data, *p_hlen, &_keyid);
436 if (!keyid)
437 return FLOW_DISSECT_RET_OUT_BAD;
438
439 if (dissector_uses_key(flow_dissector,
440 FLOW_DISSECTOR_KEY_GRE_KEYID)) {
441 key_keyid = skb_flow_dissector_target(flow_dissector,
442 FLOW_DISSECTOR_KEY_GRE_KEYID,
443 target_container);
444 if (gre_ver == 0)
445 key_keyid->keyid = *keyid;
446 else
447 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
448 }
449 offset += FIELD_SIZEOF(struct gre_full_hdr, key);
450 }
451
452 if (hdr->flags & GRE_SEQ)
453 offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
454
455 if (gre_ver == 0) {
456 if (*p_proto == htons(ETH_P_TEB)) {
457 const struct ethhdr *eth;
458 struct ethhdr _eth;
459
460 eth = __skb_header_pointer(skb, *p_nhoff + offset,
461 sizeof(_eth),
462 data, *p_hlen, &_eth);
463 if (!eth)
464 return FLOW_DISSECT_RET_OUT_BAD;
465 *p_proto = eth->h_proto;
466 offset += sizeof(*eth);
467
468 /* Cap headers that we access via pointers at the
469 * end of the Ethernet header as our maximum alignment
470 * at that point is only 2 bytes.
471 */
472 if (NET_IP_ALIGN)
473 *p_hlen = *p_nhoff + offset;
474 }
475 } else { /* version 1, must be PPTP */
476 u8 _ppp_hdr[PPP_HDRLEN];
477 u8 *ppp_hdr;
478
479 if (hdr->flags & GRE_ACK)
480 offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
481
482 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
483 sizeof(_ppp_hdr),
484 data, *p_hlen, _ppp_hdr);
485 if (!ppp_hdr)
486 return FLOW_DISSECT_RET_OUT_BAD;
487
488 switch (PPP_PROTOCOL(ppp_hdr)) {
489 case PPP_IP:
490 *p_proto = htons(ETH_P_IP);
491 break;
492 case PPP_IPV6:
493 *p_proto = htons(ETH_P_IPV6);
494 break;
495 default:
496 /* Could probably catch some more like MPLS */
497 break;
498 }
499
500 offset += PPP_HDRLEN;
501 }
502
503 *p_nhoff += offset;
504 key_control->flags |= FLOW_DIS_ENCAPSULATION;
505 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
506 return FLOW_DISSECT_RET_OUT_GOOD;
507
508 return FLOW_DISSECT_RET_PROTO_AGAIN;
509 }
510
511 /**
512 * __skb_flow_dissect_batadv() - dissect batman-adv header
513 * @skb: sk_buff to with the batman-adv header
514 * @key_control: flow dissectors control key
515 * @data: raw buffer pointer to the packet, if NULL use skb->data
516 * @p_proto: pointer used to update the protocol to process next
517 * @p_nhoff: pointer used to update inner network header offset
518 * @hlen: packet header length
519 * @flags: any combination of FLOW_DISSECTOR_F_*
520 *
521 * ETH_P_BATMAN packets are tried to be dissected. Only
522 * &struct batadv_unicast packets are actually processed because they contain an
523 * inner ethernet header and are usually followed by actual network header. This
524 * allows the flow dissector to continue processing the packet.
525 *
526 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
527 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
528 * otherwise FLOW_DISSECT_RET_OUT_BAD
529 */
530 static enum flow_dissect_ret
531 __skb_flow_dissect_batadv(const struct sk_buff *skb,
532 struct flow_dissector_key_control *key_control,
533 void *data, __be16 *p_proto, int *p_nhoff, int hlen,
534 unsigned int flags)
535 {
536 struct {
537 struct batadv_unicast_packet batadv_unicast;
538 struct ethhdr eth;
539 } *hdr, _hdr;
540
541 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
542 &_hdr);
543 if (!hdr)
544 return FLOW_DISSECT_RET_OUT_BAD;
545
546 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
547 return FLOW_DISSECT_RET_OUT_BAD;
548
549 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
550 return FLOW_DISSECT_RET_OUT_BAD;
551
552 *p_proto = hdr->eth.h_proto;
553 *p_nhoff += sizeof(*hdr);
554
555 key_control->flags |= FLOW_DIS_ENCAPSULATION;
556 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
557 return FLOW_DISSECT_RET_OUT_GOOD;
558
559 return FLOW_DISSECT_RET_PROTO_AGAIN;
560 }
561
562 static void
563 __skb_flow_dissect_tcp(const struct sk_buff *skb,
564 struct flow_dissector *flow_dissector,
565 void *target_container, void *data, int thoff, int hlen)
566 {
567 struct flow_dissector_key_tcp *key_tcp;
568 struct tcphdr *th, _th;
569
570 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
571 return;
572
573 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
574 if (!th)
575 return;
576
577 if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
578 return;
579
580 key_tcp = skb_flow_dissector_target(flow_dissector,
581 FLOW_DISSECTOR_KEY_TCP,
582 target_container);
583 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
584 }
585
586 static void
587 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
588 struct flow_dissector *flow_dissector,
589 void *target_container, void *data, const struct iphdr *iph)
590 {
591 struct flow_dissector_key_ip *key_ip;
592
593 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
594 return;
595
596 key_ip = skb_flow_dissector_target(flow_dissector,
597 FLOW_DISSECTOR_KEY_IP,
598 target_container);
599 key_ip->tos = iph->tos;
600 key_ip->ttl = iph->ttl;
601 }
602
603 static void
604 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
605 struct flow_dissector *flow_dissector,
606 void *target_container, void *data, const struct ipv6hdr *iph)
607 {
608 struct flow_dissector_key_ip *key_ip;
609
610 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
611 return;
612
613 key_ip = skb_flow_dissector_target(flow_dissector,
614 FLOW_DISSECTOR_KEY_IP,
615 target_container);
616 key_ip->tos = ipv6_get_dsfield(iph);
617 key_ip->ttl = iph->hop_limit;
618 }
619
620 /* Maximum number of protocol headers that can be parsed in
621 * __skb_flow_dissect
622 */
623 #define MAX_FLOW_DISSECT_HDRS 15
624
625 static bool skb_flow_dissect_allowed(int *num_hdrs)
626 {
627 ++*num_hdrs;
628
629 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
630 }
631
632 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
633 struct flow_dissector *flow_dissector,
634 void *target_container)
635 {
636 struct flow_dissector_key_control *key_control;
637 struct flow_dissector_key_basic *key_basic;
638 struct flow_dissector_key_addrs *key_addrs;
639 struct flow_dissector_key_ports *key_ports;
640
641 key_control = skb_flow_dissector_target(flow_dissector,
642 FLOW_DISSECTOR_KEY_CONTROL,
643 target_container);
644 key_control->thoff = flow_keys->thoff;
645 if (flow_keys->is_frag)
646 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
647 if (flow_keys->is_first_frag)
648 key_control->flags |= FLOW_DIS_FIRST_FRAG;
649 if (flow_keys->is_encap)
650 key_control->flags |= FLOW_DIS_ENCAPSULATION;
651
652 key_basic = skb_flow_dissector_target(flow_dissector,
653 FLOW_DISSECTOR_KEY_BASIC,
654 target_container);
655 key_basic->n_proto = flow_keys->n_proto;
656 key_basic->ip_proto = flow_keys->ip_proto;
657
658 if (flow_keys->addr_proto == ETH_P_IP &&
659 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
660 key_addrs = skb_flow_dissector_target(flow_dissector,
661 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
662 target_container);
663 key_addrs->v4addrs.src = flow_keys->ipv4_src;
664 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
665 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
666 } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
667 dissector_uses_key(flow_dissector,
668 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
669 key_addrs = skb_flow_dissector_target(flow_dissector,
670 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
671 target_container);
672 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
673 sizeof(key_addrs->v6addrs));
674 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
675 }
676
677 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
678 key_ports = skb_flow_dissector_target(flow_dissector,
679 FLOW_DISSECTOR_KEY_PORTS,
680 target_container);
681 key_ports->src = flow_keys->sport;
682 key_ports->dst = flow_keys->dport;
683 }
684 }
685
686 /**
687 * __skb_flow_dissect - extract the flow_keys struct and return it
688 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
689 * @flow_dissector: list of keys to dissect
690 * @target_container: target structure to put dissected values into
691 * @data: raw buffer pointer to the packet, if NULL use skb->data
692 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
693 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
694 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
695 *
696 * The function will try to retrieve individual keys into target specified
697 * by flow_dissector from either the skbuff or a raw buffer specified by the
698 * rest parameters.
699 *
700 * Caller must take care of zeroing target container memory.
701 */
702 bool __skb_flow_dissect(const struct sk_buff *skb,
703 struct flow_dissector *flow_dissector,
704 void *target_container,
705 void *data, __be16 proto, int nhoff, int hlen,
706 unsigned int flags)
707 {
708 struct flow_dissector_key_control *key_control;
709 struct flow_dissector_key_basic *key_basic;
710 struct flow_dissector_key_addrs *key_addrs;
711 struct flow_dissector_key_ports *key_ports;
712 struct flow_dissector_key_icmp *key_icmp;
713 struct flow_dissector_key_tags *key_tags;
714 struct flow_dissector_key_vlan *key_vlan;
715 enum flow_dissect_ret fdret;
716 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
717 struct bpf_prog *attached = NULL;
718 int num_hdrs = 0;
719 u8 ip_proto = 0;
720 bool ret;
721
722 if (!data) {
723 data = skb->data;
724 proto = skb_vlan_tag_present(skb) ?
725 skb->vlan_proto : skb->protocol;
726 nhoff = skb_network_offset(skb);
727 hlen = skb_headlen(skb);
728 #if IS_ENABLED(CONFIG_NET_DSA)
729 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
730 const struct dsa_device_ops *ops;
731 int offset;
732
733 ops = skb->dev->dsa_ptr->tag_ops;
734 if (ops->flow_dissect &&
735 !ops->flow_dissect(skb, &proto, &offset)) {
736 hlen -= offset;
737 nhoff += offset;
738 }
739 }
740 #endif
741 }
742
743 /* It is ensured by skb_flow_dissector_init() that control key will
744 * be always present.
745 */
746 key_control = skb_flow_dissector_target(flow_dissector,
747 FLOW_DISSECTOR_KEY_CONTROL,
748 target_container);
749
750 /* It is ensured by skb_flow_dissector_init() that basic key will
751 * be always present.
752 */
753 key_basic = skb_flow_dissector_target(flow_dissector,
754 FLOW_DISSECTOR_KEY_BASIC,
755 target_container);
756
757 rcu_read_lock();
758 if (skb) {
759 if (skb->dev)
760 attached = rcu_dereference(dev_net(skb->dev)->flow_dissector_prog);
761 else if (skb->sk)
762 attached = rcu_dereference(sock_net(skb->sk)->flow_dissector_prog);
763 else
764 WARN_ON_ONCE(1);
765 }
766 if (attached) {
767 /* Note that even though the const qualifier is discarded
768 * throughout the execution of the BPF program, all changes(the
769 * control block) are reverted after the BPF program returns.
770 * Therefore, __skb_flow_dissect does not alter the skb.
771 */
772 struct bpf_flow_keys flow_keys = {};
773 struct bpf_skb_data_end cb_saved;
774 struct bpf_skb_data_end *cb;
775 u32 result;
776
777 cb = (struct bpf_skb_data_end *)skb->cb;
778
779 /* Save Control Block */
780 memcpy(&cb_saved, cb, sizeof(cb_saved));
781 memset(cb, 0, sizeof(cb_saved));
782
783 /* Pass parameters to the BPF program */
784 cb->qdisc_cb.flow_keys = &flow_keys;
785 flow_keys.nhoff = nhoff;
786 flow_keys.thoff = nhoff;
787
788 bpf_compute_data_pointers((struct sk_buff *)skb);
789 result = BPF_PROG_RUN(attached, skb);
790
791 /* Restore state */
792 memcpy(cb, &cb_saved, sizeof(cb_saved));
793
794 flow_keys.nhoff = clamp_t(u16, flow_keys.nhoff, 0, skb->len);
795 flow_keys.thoff = clamp_t(u16, flow_keys.thoff,
796 flow_keys.nhoff, skb->len);
797
798 __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
799 target_container);
800 rcu_read_unlock();
801 return result == BPF_OK;
802 }
803 rcu_read_unlock();
804
805 if (dissector_uses_key(flow_dissector,
806 FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
807 struct ethhdr *eth = eth_hdr(skb);
808 struct flow_dissector_key_eth_addrs *key_eth_addrs;
809
810 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
811 FLOW_DISSECTOR_KEY_ETH_ADDRS,
812 target_container);
813 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
814 }
815
816 proto_again:
817 fdret = FLOW_DISSECT_RET_CONTINUE;
818
819 switch (proto) {
820 case htons(ETH_P_IP): {
821 const struct iphdr *iph;
822 struct iphdr _iph;
823
824 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
825 if (!iph || iph->ihl < 5) {
826 fdret = FLOW_DISSECT_RET_OUT_BAD;
827 break;
828 }
829
830 nhoff += iph->ihl * 4;
831
832 ip_proto = iph->protocol;
833
834 if (dissector_uses_key(flow_dissector,
835 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
836 key_addrs = skb_flow_dissector_target(flow_dissector,
837 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
838 target_container);
839
840 memcpy(&key_addrs->v4addrs, &iph->saddr,
841 sizeof(key_addrs->v4addrs));
842 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
843 }
844
845 if (ip_is_fragment(iph)) {
846 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
847
848 if (iph->frag_off & htons(IP_OFFSET)) {
849 fdret = FLOW_DISSECT_RET_OUT_GOOD;
850 break;
851 } else {
852 key_control->flags |= FLOW_DIS_FIRST_FRAG;
853 if (!(flags &
854 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
855 fdret = FLOW_DISSECT_RET_OUT_GOOD;
856 break;
857 }
858 }
859 }
860
861 __skb_flow_dissect_ipv4(skb, flow_dissector,
862 target_container, data, iph);
863
864 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
865 fdret = FLOW_DISSECT_RET_OUT_GOOD;
866 break;
867 }
868
869 break;
870 }
871 case htons(ETH_P_IPV6): {
872 const struct ipv6hdr *iph;
873 struct ipv6hdr _iph;
874
875 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
876 if (!iph) {
877 fdret = FLOW_DISSECT_RET_OUT_BAD;
878 break;
879 }
880
881 ip_proto = iph->nexthdr;
882 nhoff += sizeof(struct ipv6hdr);
883
884 if (dissector_uses_key(flow_dissector,
885 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
886 key_addrs = skb_flow_dissector_target(flow_dissector,
887 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
888 target_container);
889
890 memcpy(&key_addrs->v6addrs, &iph->saddr,
891 sizeof(key_addrs->v6addrs));
892 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
893 }
894
895 if ((dissector_uses_key(flow_dissector,
896 FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
897 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
898 ip6_flowlabel(iph)) {
899 __be32 flow_label = ip6_flowlabel(iph);
900
901 if (dissector_uses_key(flow_dissector,
902 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
903 key_tags = skb_flow_dissector_target(flow_dissector,
904 FLOW_DISSECTOR_KEY_FLOW_LABEL,
905 target_container);
906 key_tags->flow_label = ntohl(flow_label);
907 }
908 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
909 fdret = FLOW_DISSECT_RET_OUT_GOOD;
910 break;
911 }
912 }
913
914 __skb_flow_dissect_ipv6(skb, flow_dissector,
915 target_container, data, iph);
916
917 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
918 fdret = FLOW_DISSECT_RET_OUT_GOOD;
919
920 break;
921 }
922 case htons(ETH_P_8021AD):
923 case htons(ETH_P_8021Q): {
924 const struct vlan_hdr *vlan = NULL;
925 struct vlan_hdr _vlan;
926 __be16 saved_vlan_tpid = proto;
927
928 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
929 skb && skb_vlan_tag_present(skb)) {
930 proto = skb->protocol;
931 } else {
932 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
933 data, hlen, &_vlan);
934 if (!vlan) {
935 fdret = FLOW_DISSECT_RET_OUT_BAD;
936 break;
937 }
938
939 proto = vlan->h_vlan_encapsulated_proto;
940 nhoff += sizeof(*vlan);
941 }
942
943 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
944 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
945 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
946 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
947 } else {
948 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
949 break;
950 }
951
952 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
953 key_vlan = skb_flow_dissector_target(flow_dissector,
954 dissector_vlan,
955 target_container);
956
957 if (!vlan) {
958 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
959 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
960 } else {
961 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
962 VLAN_VID_MASK;
963 key_vlan->vlan_priority =
964 (ntohs(vlan->h_vlan_TCI) &
965 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
966 }
967 key_vlan->vlan_tpid = saved_vlan_tpid;
968 }
969
970 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
971 break;
972 }
973 case htons(ETH_P_PPP_SES): {
974 struct {
975 struct pppoe_hdr hdr;
976 __be16 proto;
977 } *hdr, _hdr;
978 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
979 if (!hdr) {
980 fdret = FLOW_DISSECT_RET_OUT_BAD;
981 break;
982 }
983
984 proto = hdr->proto;
985 nhoff += PPPOE_SES_HLEN;
986 switch (proto) {
987 case htons(PPP_IP):
988 proto = htons(ETH_P_IP);
989 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
990 break;
991 case htons(PPP_IPV6):
992 proto = htons(ETH_P_IPV6);
993 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
994 break;
995 default:
996 fdret = FLOW_DISSECT_RET_OUT_BAD;
997 break;
998 }
999 break;
1000 }
1001 case htons(ETH_P_TIPC): {
1002 struct tipc_basic_hdr *hdr, _hdr;
1003
1004 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1005 data, hlen, &_hdr);
1006 if (!hdr) {
1007 fdret = FLOW_DISSECT_RET_OUT_BAD;
1008 break;
1009 }
1010
1011 if (dissector_uses_key(flow_dissector,
1012 FLOW_DISSECTOR_KEY_TIPC)) {
1013 key_addrs = skb_flow_dissector_target(flow_dissector,
1014 FLOW_DISSECTOR_KEY_TIPC,
1015 target_container);
1016 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1017 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1018 }
1019 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1020 break;
1021 }
1022
1023 case htons(ETH_P_MPLS_UC):
1024 case htons(ETH_P_MPLS_MC):
1025 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1026 target_container, data,
1027 nhoff, hlen);
1028 break;
1029 case htons(ETH_P_FCOE):
1030 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1031 fdret = FLOW_DISSECT_RET_OUT_BAD;
1032 break;
1033 }
1034
1035 nhoff += FCOE_HEADER_LEN;
1036 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1037 break;
1038
1039 case htons(ETH_P_ARP):
1040 case htons(ETH_P_RARP):
1041 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1042 target_container, data,
1043 nhoff, hlen);
1044 break;
1045
1046 case htons(ETH_P_BATMAN):
1047 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1048 &proto, &nhoff, hlen, flags);
1049 break;
1050
1051 default:
1052 fdret = FLOW_DISSECT_RET_OUT_BAD;
1053 break;
1054 }
1055
1056 /* Process result of proto processing */
1057 switch (fdret) {
1058 case FLOW_DISSECT_RET_OUT_GOOD:
1059 goto out_good;
1060 case FLOW_DISSECT_RET_PROTO_AGAIN:
1061 if (skb_flow_dissect_allowed(&num_hdrs))
1062 goto proto_again;
1063 goto out_good;
1064 case FLOW_DISSECT_RET_CONTINUE:
1065 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1066 break;
1067 case FLOW_DISSECT_RET_OUT_BAD:
1068 default:
1069 goto out_bad;
1070 }
1071
1072 ip_proto_again:
1073 fdret = FLOW_DISSECT_RET_CONTINUE;
1074
1075 switch (ip_proto) {
1076 case IPPROTO_GRE:
1077 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1078 target_container, data,
1079 &proto, &nhoff, &hlen, flags);
1080 break;
1081
1082 case NEXTHDR_HOP:
1083 case NEXTHDR_ROUTING:
1084 case NEXTHDR_DEST: {
1085 u8 _opthdr[2], *opthdr;
1086
1087 if (proto != htons(ETH_P_IPV6))
1088 break;
1089
1090 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1091 data, hlen, &_opthdr);
1092 if (!opthdr) {
1093 fdret = FLOW_DISSECT_RET_OUT_BAD;
1094 break;
1095 }
1096
1097 ip_proto = opthdr[0];
1098 nhoff += (opthdr[1] + 1) << 3;
1099
1100 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1101 break;
1102 }
1103 case NEXTHDR_FRAGMENT: {
1104 struct frag_hdr _fh, *fh;
1105
1106 if (proto != htons(ETH_P_IPV6))
1107 break;
1108
1109 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1110 data, hlen, &_fh);
1111
1112 if (!fh) {
1113 fdret = FLOW_DISSECT_RET_OUT_BAD;
1114 break;
1115 }
1116
1117 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1118
1119 nhoff += sizeof(_fh);
1120 ip_proto = fh->nexthdr;
1121
1122 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1123 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1124 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1125 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1126 break;
1127 }
1128 }
1129
1130 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1131 break;
1132 }
1133 case IPPROTO_IPIP:
1134 proto = htons(ETH_P_IP);
1135
1136 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1137 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1138 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1139 break;
1140 }
1141
1142 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1143 break;
1144
1145 case IPPROTO_IPV6:
1146 proto = htons(ETH_P_IPV6);
1147
1148 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1149 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1150 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1151 break;
1152 }
1153
1154 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1155 break;
1156
1157
1158 case IPPROTO_MPLS:
1159 proto = htons(ETH_P_MPLS_UC);
1160 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1161 break;
1162
1163 case IPPROTO_TCP:
1164 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1165 data, nhoff, hlen);
1166 break;
1167
1168 default:
1169 break;
1170 }
1171
1172 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1173 !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1174 key_ports = skb_flow_dissector_target(flow_dissector,
1175 FLOW_DISSECTOR_KEY_PORTS,
1176 target_container);
1177 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1178 data, hlen);
1179 }
1180
1181 if (dissector_uses_key(flow_dissector,
1182 FLOW_DISSECTOR_KEY_ICMP)) {
1183 key_icmp = skb_flow_dissector_target(flow_dissector,
1184 FLOW_DISSECTOR_KEY_ICMP,
1185 target_container);
1186 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1187 }
1188
1189 /* Process result of IP proto processing */
1190 switch (fdret) {
1191 case FLOW_DISSECT_RET_PROTO_AGAIN:
1192 if (skb_flow_dissect_allowed(&num_hdrs))
1193 goto proto_again;
1194 break;
1195 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1196 if (skb_flow_dissect_allowed(&num_hdrs))
1197 goto ip_proto_again;
1198 break;
1199 case FLOW_DISSECT_RET_OUT_GOOD:
1200 case FLOW_DISSECT_RET_CONTINUE:
1201 break;
1202 case FLOW_DISSECT_RET_OUT_BAD:
1203 default:
1204 goto out_bad;
1205 }
1206
1207 out_good:
1208 ret = true;
1209
1210 out:
1211 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1212 key_basic->n_proto = proto;
1213 key_basic->ip_proto = ip_proto;
1214
1215 return ret;
1216
1217 out_bad:
1218 ret = false;
1219 goto out;
1220 }
1221 EXPORT_SYMBOL(__skb_flow_dissect);
1222
1223 static u32 hashrnd __read_mostly;
1224 static __always_inline void __flow_hash_secret_init(void)
1225 {
1226 net_get_random_once(&hashrnd, sizeof(hashrnd));
1227 }
1228
1229 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1230 u32 keyval)
1231 {
1232 return jhash2(words, length, keyval);
1233 }
1234
1235 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1236 {
1237 const void *p = flow;
1238
1239 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1240 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1241 }
1242
1243 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1244 {
1245 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1246 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1247 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1248 sizeof(*flow) - sizeof(flow->addrs));
1249
1250 switch (flow->control.addr_type) {
1251 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1252 diff -= sizeof(flow->addrs.v4addrs);
1253 break;
1254 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1255 diff -= sizeof(flow->addrs.v6addrs);
1256 break;
1257 case FLOW_DISSECTOR_KEY_TIPC:
1258 diff -= sizeof(flow->addrs.tipckey);
1259 break;
1260 }
1261 return (sizeof(*flow) - diff) / sizeof(u32);
1262 }
1263
1264 __be32 flow_get_u32_src(const struct flow_keys *flow)
1265 {
1266 switch (flow->control.addr_type) {
1267 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1268 return flow->addrs.v4addrs.src;
1269 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1270 return (__force __be32)ipv6_addr_hash(
1271 &flow->addrs.v6addrs.src);
1272 case FLOW_DISSECTOR_KEY_TIPC:
1273 return flow->addrs.tipckey.key;
1274 default:
1275 return 0;
1276 }
1277 }
1278 EXPORT_SYMBOL(flow_get_u32_src);
1279
1280 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1281 {
1282 switch (flow->control.addr_type) {
1283 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1284 return flow->addrs.v4addrs.dst;
1285 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1286 return (__force __be32)ipv6_addr_hash(
1287 &flow->addrs.v6addrs.dst);
1288 default:
1289 return 0;
1290 }
1291 }
1292 EXPORT_SYMBOL(flow_get_u32_dst);
1293
1294 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1295 {
1296 int addr_diff, i;
1297
1298 switch (keys->control.addr_type) {
1299 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1300 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1301 (__force u32)keys->addrs.v4addrs.src;
1302 if ((addr_diff < 0) ||
1303 (addr_diff == 0 &&
1304 ((__force u16)keys->ports.dst <
1305 (__force u16)keys->ports.src))) {
1306 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1307 swap(keys->ports.src, keys->ports.dst);
1308 }
1309 break;
1310 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1311 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1312 &keys->addrs.v6addrs.src,
1313 sizeof(keys->addrs.v6addrs.dst));
1314 if ((addr_diff < 0) ||
1315 (addr_diff == 0 &&
1316 ((__force u16)keys->ports.dst <
1317 (__force u16)keys->ports.src))) {
1318 for (i = 0; i < 4; i++)
1319 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1320 keys->addrs.v6addrs.dst.s6_addr32[i]);
1321 swap(keys->ports.src, keys->ports.dst);
1322 }
1323 break;
1324 }
1325 }
1326
1327 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1328 {
1329 u32 hash;
1330
1331 __flow_hash_consistentify(keys);
1332
1333 hash = __flow_hash_words(flow_keys_hash_start(keys),
1334 flow_keys_hash_length(keys), keyval);
1335 if (!hash)
1336 hash = 1;
1337
1338 return hash;
1339 }
1340
1341 u32 flow_hash_from_keys(struct flow_keys *keys)
1342 {
1343 __flow_hash_secret_init();
1344 return __flow_hash_from_keys(keys, hashrnd);
1345 }
1346 EXPORT_SYMBOL(flow_hash_from_keys);
1347
1348 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1349 struct flow_keys *keys, u32 keyval)
1350 {
1351 skb_flow_dissect_flow_keys(skb, keys,
1352 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1353
1354 return __flow_hash_from_keys(keys, keyval);
1355 }
1356
1357 struct _flow_keys_digest_data {
1358 __be16 n_proto;
1359 u8 ip_proto;
1360 u8 padding;
1361 __be32 ports;
1362 __be32 src;
1363 __be32 dst;
1364 };
1365
1366 void make_flow_keys_digest(struct flow_keys_digest *digest,
1367 const struct flow_keys *flow)
1368 {
1369 struct _flow_keys_digest_data *data =
1370 (struct _flow_keys_digest_data *)digest;
1371
1372 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1373
1374 memset(digest, 0, sizeof(*digest));
1375
1376 data->n_proto = flow->basic.n_proto;
1377 data->ip_proto = flow->basic.ip_proto;
1378 data->ports = flow->ports.ports;
1379 data->src = flow->addrs.v4addrs.src;
1380 data->dst = flow->addrs.v4addrs.dst;
1381 }
1382 EXPORT_SYMBOL(make_flow_keys_digest);
1383
1384 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1385
1386 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1387 {
1388 struct flow_keys keys;
1389
1390 __flow_hash_secret_init();
1391
1392 memset(&keys, 0, sizeof(keys));
1393 __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1394 NULL, 0, 0, 0,
1395 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1396
1397 return __flow_hash_from_keys(&keys, hashrnd);
1398 }
1399 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1400
1401 /**
1402 * __skb_get_hash: calculate a flow hash
1403 * @skb: sk_buff to calculate flow hash from
1404 *
1405 * This function calculates a flow hash based on src/dst addresses
1406 * and src/dst port numbers. Sets hash in skb to non-zero hash value
1407 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
1408 * if hash is a canonical 4-tuple hash over transport ports.
1409 */
1410 void __skb_get_hash(struct sk_buff *skb)
1411 {
1412 struct flow_keys keys;
1413 u32 hash;
1414
1415 __flow_hash_secret_init();
1416
1417 hash = ___skb_get_hash(skb, &keys, hashrnd);
1418
1419 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1420 }
1421 EXPORT_SYMBOL(__skb_get_hash);
1422
1423 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1424 {
1425 struct flow_keys keys;
1426
1427 return ___skb_get_hash(skb, &keys, perturb);
1428 }
1429 EXPORT_SYMBOL(skb_get_hash_perturb);
1430
1431 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1432 const struct flow_keys_basic *keys, int hlen)
1433 {
1434 u32 poff = keys->control.thoff;
1435
1436 /* skip L4 headers for fragments after the first */
1437 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1438 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1439 return poff;
1440
1441 switch (keys->basic.ip_proto) {
1442 case IPPROTO_TCP: {
1443 /* access doff as u8 to avoid unaligned access */
1444 const u8 *doff;
1445 u8 _doff;
1446
1447 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1448 data, hlen, &_doff);
1449 if (!doff)
1450 return poff;
1451
1452 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1453 break;
1454 }
1455 case IPPROTO_UDP:
1456 case IPPROTO_UDPLITE:
1457 poff += sizeof(struct udphdr);
1458 break;
1459 /* For the rest, we do not really care about header
1460 * extensions at this point for now.
1461 */
1462 case IPPROTO_ICMP:
1463 poff += sizeof(struct icmphdr);
1464 break;
1465 case IPPROTO_ICMPV6:
1466 poff += sizeof(struct icmp6hdr);
1467 break;
1468 case IPPROTO_IGMP:
1469 poff += sizeof(struct igmphdr);
1470 break;
1471 case IPPROTO_DCCP:
1472 poff += sizeof(struct dccp_hdr);
1473 break;
1474 case IPPROTO_SCTP:
1475 poff += sizeof(struct sctphdr);
1476 break;
1477 }
1478
1479 return poff;
1480 }
1481
1482 /**
1483 * skb_get_poff - get the offset to the payload
1484 * @skb: sk_buff to get the payload offset from
1485 *
1486 * The function will get the offset to the payload as far as it could
1487 * be dissected. The main user is currently BPF, so that we can dynamically
1488 * truncate packets without needing to push actual payload to the user
1489 * space and can analyze headers only, instead.
1490 */
1491 u32 skb_get_poff(const struct sk_buff *skb)
1492 {
1493 struct flow_keys_basic keys;
1494
1495 if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1496 return 0;
1497
1498 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1499 }
1500
1501 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1502 {
1503 memset(keys, 0, sizeof(*keys));
1504
1505 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1506 sizeof(keys->addrs.v6addrs.src));
1507 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1508 sizeof(keys->addrs.v6addrs.dst));
1509 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1510 keys->ports.src = fl6->fl6_sport;
1511 keys->ports.dst = fl6->fl6_dport;
1512 keys->keyid.keyid = fl6->fl6_gre_key;
1513 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1514 keys->basic.ip_proto = fl6->flowi6_proto;
1515
1516 return flow_hash_from_keys(keys);
1517 }
1518 EXPORT_SYMBOL(__get_hash_from_flowi6);
1519
1520 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1521 {
1522 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1523 .offset = offsetof(struct flow_keys, control),
1524 },
1525 {
1526 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1527 .offset = offsetof(struct flow_keys, basic),
1528 },
1529 {
1530 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1531 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1532 },
1533 {
1534 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1535 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1536 },
1537 {
1538 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1539 .offset = offsetof(struct flow_keys, addrs.tipckey),
1540 },
1541 {
1542 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1543 .offset = offsetof(struct flow_keys, ports),
1544 },
1545 {
1546 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1547 .offset = offsetof(struct flow_keys, vlan),
1548 },
1549 {
1550 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1551 .offset = offsetof(struct flow_keys, tags),
1552 },
1553 {
1554 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1555 .offset = offsetof(struct flow_keys, keyid),
1556 },
1557 };
1558
1559 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1560 {
1561 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1562 .offset = offsetof(struct flow_keys, control),
1563 },
1564 {
1565 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1566 .offset = offsetof(struct flow_keys, basic),
1567 },
1568 {
1569 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1570 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1571 },
1572 {
1573 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1574 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1575 },
1576 {
1577 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1578 .offset = offsetof(struct flow_keys, ports),
1579 },
1580 };
1581
1582 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1583 {
1584 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1585 .offset = offsetof(struct flow_keys, control),
1586 },
1587 {
1588 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1589 .offset = offsetof(struct flow_keys, basic),
1590 },
1591 };
1592
1593 struct flow_dissector flow_keys_dissector __read_mostly;
1594 EXPORT_SYMBOL(flow_keys_dissector);
1595
1596 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1597 EXPORT_SYMBOL(flow_keys_basic_dissector);
1598
1599 static int __init init_default_flow_dissectors(void)
1600 {
1601 skb_flow_dissector_init(&flow_keys_dissector,
1602 flow_keys_dissector_keys,
1603 ARRAY_SIZE(flow_keys_dissector_keys));
1604 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1605 flow_keys_dissector_symmetric_keys,
1606 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1607 skb_flow_dissector_init(&flow_keys_basic_dissector,
1608 flow_keys_basic_dissector_keys,
1609 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1610 return 0;
1611 }
1612
1613 core_initcall(init_default_flow_dissectors);
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