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Linux 4.13.16
[linux/fpc-iii.git] / net / core / flow_dissector.c
blobfc5fc4594c908049c5141858338848c8d12eb0d5
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/ip.h>
8 #include <net/ipv6.h>
9 #include <net/gre.h>
10 #include <net/pptp.h>
11 #include <linux/igmp.h>
12 #include <linux/icmp.h>
13 #include <linux/sctp.h>
14 #include <linux/dccp.h>
15 #include <linux/if_tunnel.h>
16 #include <linux/if_pppox.h>
17 #include <linux/ppp_defs.h>
18 #include <linux/stddef.h>
19 #include <linux/if_ether.h>
20 #include <linux/mpls.h>
21 #include <linux/tcp.h>
22 #include <net/flow_dissector.h>
23 #include <scsi/fc/fc_fcoe.h>
24
25 static void dissector_set_key(struct flow_dissector *flow_dissector,
26 enum flow_dissector_key_id key_id)
27 {
28 flow_dissector->used_keys |= (1 << key_id);
29 }
30
31 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
32 const struct flow_dissector_key *key,
33 unsigned int key_count)
34 {
35 unsigned int i;
36
37 memset(flow_dissector, 0, sizeof(*flow_dissector));
38
39 for (i = 0; i < key_count; i++, key++) {
40 /* User should make sure that every key target offset is withing
41 * boundaries of unsigned short.
42 */
43 BUG_ON(key->offset > USHRT_MAX);
44 BUG_ON(dissector_uses_key(flow_dissector,
45 key->key_id));
46
47 dissector_set_key(flow_dissector, key->key_id);
48 flow_dissector->offset[key->key_id] = key->offset;
49 }
50
51 /* Ensure that the dissector always includes control and basic key.
52 * That way we are able to avoid handling lack of these in fast path.
53 */
54 BUG_ON(!dissector_uses_key(flow_dissector,
55 FLOW_DISSECTOR_KEY_CONTROL));
56 BUG_ON(!dissector_uses_key(flow_dissector,
57 FLOW_DISSECTOR_KEY_BASIC));
58 }
59 EXPORT_SYMBOL(skb_flow_dissector_init);
60
61 /**
62 * skb_flow_get_be16 - extract be16 entity
63 * @skb: sk_buff to extract from
64 * @poff: offset to extract at
65 * @data: raw buffer pointer to the packet
66 * @hlen: packet header length
67 *
68 * The function will try to retrieve a be32 entity at
69 * offset poff
70 */
71 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
72 void *data, int hlen)
73 {
74 __be16 *u, _u;
75
76 u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
77 if (u)
78 return *u;
79
80 return 0;
81 }
82
83 /**
84 * __skb_flow_get_ports - extract the upper layer ports and return them
85 * @skb: sk_buff to extract the ports from
86 * @thoff: transport header offset
87 * @ip_proto: protocol for which to get port offset
88 * @data: raw buffer pointer to the packet, if NULL use skb->data
89 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
90 *
91 * The function will try to retrieve the ports at offset thoff + poff where poff
92 * is the protocol port offset returned from proto_ports_offset
93 */
94 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
95 void *data, int hlen)
96 {
97 int poff = proto_ports_offset(ip_proto);
98
99 if (!data) {
100 data = skb->data;
101 hlen = skb_headlen(skb);
102 }
103
104 if (poff >= 0) {
105 __be32 *ports, _ports;
106
107 ports = __skb_header_pointer(skb, thoff + poff,
108 sizeof(_ports), data, hlen, &_ports);
109 if (ports)
110 return *ports;
111 }
112
113 return 0;
114 }
115 EXPORT_SYMBOL(__skb_flow_get_ports);
116
117 enum flow_dissect_ret {
118 FLOW_DISSECT_RET_OUT_GOOD,
119 FLOW_DISSECT_RET_OUT_BAD,
120 FLOW_DISSECT_RET_OUT_PROTO_AGAIN,
121 };
122
123 static enum flow_dissect_ret
124 __skb_flow_dissect_mpls(const struct sk_buff *skb,
125 struct flow_dissector *flow_dissector,
126 void *target_container, void *data, int nhoff, int hlen)
127 {
128 struct flow_dissector_key_keyid *key_keyid;
129 struct mpls_label *hdr, _hdr[2];
130 u32 entry, label;
131
132 if (!dissector_uses_key(flow_dissector,
133 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
134 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
135 return FLOW_DISSECT_RET_OUT_GOOD;
136
137 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
138 hlen, &_hdr);
139 if (!hdr)
140 return FLOW_DISSECT_RET_OUT_BAD;
141
142 entry = ntohl(hdr[0].entry);
143 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
144
145 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
146 struct flow_dissector_key_mpls *key_mpls;
147
148 key_mpls = skb_flow_dissector_target(flow_dissector,
149 FLOW_DISSECTOR_KEY_MPLS,
150 target_container);
151 key_mpls->mpls_label = label;
152 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
153 >> MPLS_LS_TTL_SHIFT;
154 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
155 >> MPLS_LS_TC_SHIFT;
156 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
157 >> MPLS_LS_S_SHIFT;
158 }
159
160 if (label == MPLS_LABEL_ENTROPY) {
161 key_keyid = skb_flow_dissector_target(flow_dissector,
162 FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
163 target_container);
164 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
165 }
166 return FLOW_DISSECT_RET_OUT_GOOD;
167 }
168
169 static enum flow_dissect_ret
170 __skb_flow_dissect_arp(const struct sk_buff *skb,
171 struct flow_dissector *flow_dissector,
172 void *target_container, void *data, int nhoff, int hlen)
173 {
174 struct flow_dissector_key_arp *key_arp;
175 struct {
176 unsigned char ar_sha[ETH_ALEN];
177 unsigned char ar_sip[4];
178 unsigned char ar_tha[ETH_ALEN];
179 unsigned char ar_tip[4];
180 } *arp_eth, _arp_eth;
181 const struct arphdr *arp;
182 struct arphdr _arp;
183
184 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
185 return FLOW_DISSECT_RET_OUT_GOOD;
186
187 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
188 hlen, &_arp);
189 if (!arp)
190 return FLOW_DISSECT_RET_OUT_BAD;
191
192 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
193 arp->ar_pro != htons(ETH_P_IP) ||
194 arp->ar_hln != ETH_ALEN ||
195 arp->ar_pln != 4 ||
196 (arp->ar_op != htons(ARPOP_REPLY) &&
197 arp->ar_op != htons(ARPOP_REQUEST)))
198 return FLOW_DISSECT_RET_OUT_BAD;
199
200 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
201 sizeof(_arp_eth), data,
202 hlen, &_arp_eth);
203 if (!arp_eth)
204 return FLOW_DISSECT_RET_OUT_BAD;
205
206 key_arp = skb_flow_dissector_target(flow_dissector,
207 FLOW_DISSECTOR_KEY_ARP,
208 target_container);
209
210 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
211 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
212
213 /* Only store the lower byte of the opcode;
214 * this covers ARPOP_REPLY and ARPOP_REQUEST.
215 */
216 key_arp->op = ntohs(arp->ar_op) & 0xff;
217
218 ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
219 ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
220
221 return FLOW_DISSECT_RET_OUT_GOOD;
222 }
223
224 static enum flow_dissect_ret
225 __skb_flow_dissect_gre(const struct sk_buff *skb,
226 struct flow_dissector_key_control *key_control,
227 struct flow_dissector *flow_dissector,
228 void *target_container, void *data,
229 __be16 *p_proto, int *p_nhoff, int *p_hlen,
230 unsigned int flags)
231 {
232 struct flow_dissector_key_keyid *key_keyid;
233 struct gre_base_hdr *hdr, _hdr;
234 int offset = 0;
235 u16 gre_ver;
236
237 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
238 data, *p_hlen, &_hdr);
239 if (!hdr)
240 return FLOW_DISSECT_RET_OUT_BAD;
241
242 /* Only look inside GRE without routing */
243 if (hdr->flags & GRE_ROUTING)
244 return FLOW_DISSECT_RET_OUT_GOOD;
245
246 /* Only look inside GRE for version 0 and 1 */
247 gre_ver = ntohs(hdr->flags & GRE_VERSION);
248 if (gre_ver > 1)
249 return FLOW_DISSECT_RET_OUT_GOOD;
250
251 *p_proto = hdr->protocol;
252 if (gre_ver) {
253 /* Version1 must be PPTP, and check the flags */
254 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
255 return FLOW_DISSECT_RET_OUT_GOOD;
256 }
257
258 offset += sizeof(struct gre_base_hdr);
259
260 if (hdr->flags & GRE_CSUM)
261 offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
262 sizeof(((struct gre_full_hdr *) 0)->reserved1);
263
264 if (hdr->flags & GRE_KEY) {
265 const __be32 *keyid;
266 __be32 _keyid;
267
268 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
269 sizeof(_keyid),
270 data, *p_hlen, &_keyid);
271 if (!keyid)
272 return FLOW_DISSECT_RET_OUT_BAD;
273
274 if (dissector_uses_key(flow_dissector,
275 FLOW_DISSECTOR_KEY_GRE_KEYID)) {
276 key_keyid = skb_flow_dissector_target(flow_dissector,
277 FLOW_DISSECTOR_KEY_GRE_KEYID,
278 target_container);
279 if (gre_ver == 0)
280 key_keyid->keyid = *keyid;
281 else
282 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
283 }
284 offset += sizeof(((struct gre_full_hdr *) 0)->key);
285 }
286
287 if (hdr->flags & GRE_SEQ)
288 offset += sizeof(((struct pptp_gre_header *) 0)->seq);
289
290 if (gre_ver == 0) {
291 if (*p_proto == htons(ETH_P_TEB)) {
292 const struct ethhdr *eth;
293 struct ethhdr _eth;
294
295 eth = __skb_header_pointer(skb, *p_nhoff + offset,
296 sizeof(_eth),
297 data, *p_hlen, &_eth);
298 if (!eth)
299 return FLOW_DISSECT_RET_OUT_BAD;
300 *p_proto = eth->h_proto;
301 offset += sizeof(*eth);
302
303 /* Cap headers that we access via pointers at the
304 * end of the Ethernet header as our maximum alignment
305 * at that point is only 2 bytes.
306 */
307 if (NET_IP_ALIGN)
308 *p_hlen = *p_nhoff + offset;
309 }
310 } else { /* version 1, must be PPTP */
311 u8 _ppp_hdr[PPP_HDRLEN];
312 u8 *ppp_hdr;
313
314 if (hdr->flags & GRE_ACK)
315 offset += sizeof(((struct pptp_gre_header *) 0)->ack);
316
317 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
318 sizeof(_ppp_hdr),
319 data, *p_hlen, _ppp_hdr);
320 if (!ppp_hdr)
321 return FLOW_DISSECT_RET_OUT_BAD;
322
323 switch (PPP_PROTOCOL(ppp_hdr)) {
324 case PPP_IP:
325 *p_proto = htons(ETH_P_IP);
326 break;
327 case PPP_IPV6:
328 *p_proto = htons(ETH_P_IPV6);
329 break;
330 default:
331 /* Could probably catch some more like MPLS */
332 break;
333 }
334
335 offset += PPP_HDRLEN;
336 }
337
338 *p_nhoff += offset;
339 key_control->flags |= FLOW_DIS_ENCAPSULATION;
340 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
341 return FLOW_DISSECT_RET_OUT_GOOD;
342
343 return FLOW_DISSECT_RET_OUT_PROTO_AGAIN;
344 }
345
346 static void
347 __skb_flow_dissect_tcp(const struct sk_buff *skb,
348 struct flow_dissector *flow_dissector,
349 void *target_container, void *data, int thoff, int hlen)
350 {
351 struct flow_dissector_key_tcp *key_tcp;
352 struct tcphdr *th, _th;
353
354 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
355 return;
356
357 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
358 if (!th)
359 return;
360
361 if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
362 return;
363
364 key_tcp = skb_flow_dissector_target(flow_dissector,
365 FLOW_DISSECTOR_KEY_TCP,
366 target_container);
367 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
368 }
369
370 static void
371 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
372 struct flow_dissector *flow_dissector,
373 void *target_container, void *data, const struct iphdr *iph)
374 {
375 struct flow_dissector_key_ip *key_ip;
376
377 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
378 return;
379
380 key_ip = skb_flow_dissector_target(flow_dissector,
381 FLOW_DISSECTOR_KEY_IP,
382 target_container);
383 key_ip->tos = iph->tos;
384 key_ip->ttl = iph->ttl;
385 }
386
387 static void
388 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
389 struct flow_dissector *flow_dissector,
390 void *target_container, void *data, const struct ipv6hdr *iph)
391 {
392 struct flow_dissector_key_ip *key_ip;
393
394 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
395 return;
396
397 key_ip = skb_flow_dissector_target(flow_dissector,
398 FLOW_DISSECTOR_KEY_IP,
399 target_container);
400 key_ip->tos = ipv6_get_dsfield(iph);
401 key_ip->ttl = iph->hop_limit;
402 }
403
404 /**
405 * __skb_flow_dissect - extract the flow_keys struct and return it
406 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
407 * @flow_dissector: list of keys to dissect
408 * @target_container: target structure to put dissected values into
409 * @data: raw buffer pointer to the packet, if NULL use skb->data
410 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
411 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
412 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
413 *
414 * The function will try to retrieve individual keys into target specified
415 * by flow_dissector from either the skbuff or a raw buffer specified by the
416 * rest parameters.
417 *
418 * Caller must take care of zeroing target container memory.
419 */
420 bool __skb_flow_dissect(const struct sk_buff *skb,
421 struct flow_dissector *flow_dissector,
422 void *target_container,
423 void *data, __be16 proto, int nhoff, int hlen,
424 unsigned int flags)
425 {
426 struct flow_dissector_key_control *key_control;
427 struct flow_dissector_key_basic *key_basic;
428 struct flow_dissector_key_addrs *key_addrs;
429 struct flow_dissector_key_ports *key_ports;
430 struct flow_dissector_key_icmp *key_icmp;
431 struct flow_dissector_key_tags *key_tags;
432 struct flow_dissector_key_vlan *key_vlan;
433 bool skip_vlan = false;
434 u8 ip_proto = 0;
435 bool ret;
436
437 if (!data) {
438 data = skb->data;
439 proto = skb_vlan_tag_present(skb) ?
440 skb->vlan_proto : skb->protocol;
441 nhoff = skb_network_offset(skb);
442 hlen = skb_headlen(skb);
443 }
444
445 /* It is ensured by skb_flow_dissector_init() that control key will
446 * be always present.
447 */
448 key_control = skb_flow_dissector_target(flow_dissector,
449 FLOW_DISSECTOR_KEY_CONTROL,
450 target_container);
451
452 /* It is ensured by skb_flow_dissector_init() that basic key will
453 * be always present.
454 */
455 key_basic = skb_flow_dissector_target(flow_dissector,
456 FLOW_DISSECTOR_KEY_BASIC,
457 target_container);
458
459 if (dissector_uses_key(flow_dissector,
460 FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
461 struct ethhdr *eth = eth_hdr(skb);
462 struct flow_dissector_key_eth_addrs *key_eth_addrs;
463
464 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
465 FLOW_DISSECTOR_KEY_ETH_ADDRS,
466 target_container);
467 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
468 }
469
470 proto_again:
471 switch (proto) {
472 case htons(ETH_P_IP): {
473 const struct iphdr *iph;
474 struct iphdr _iph;
475 ip:
476 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
477 if (!iph || iph->ihl < 5)
478 goto out_bad;
479 nhoff += iph->ihl * 4;
480
481 ip_proto = iph->protocol;
482
483 if (dissector_uses_key(flow_dissector,
484 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
485 key_addrs = skb_flow_dissector_target(flow_dissector,
486 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
487 target_container);
488
489 memcpy(&key_addrs->v4addrs, &iph->saddr,
490 sizeof(key_addrs->v4addrs));
491 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
492 }
493
494 if (ip_is_fragment(iph)) {
495 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
496
497 if (iph->frag_off & htons(IP_OFFSET)) {
498 goto out_good;
499 } else {
500 key_control->flags |= FLOW_DIS_FIRST_FRAG;
501 if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
502 goto out_good;
503 }
504 }
505
506 __skb_flow_dissect_ipv4(skb, flow_dissector,
507 target_container, data, iph);
508
509 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
510 goto out_good;
511
512 break;
513 }
514 case htons(ETH_P_IPV6): {
515 const struct ipv6hdr *iph;
516 struct ipv6hdr _iph;
517
518 ipv6:
519 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
520 if (!iph)
521 goto out_bad;
522
523 ip_proto = iph->nexthdr;
524 nhoff += sizeof(struct ipv6hdr);
525
526 if (dissector_uses_key(flow_dissector,
527 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
528 key_addrs = skb_flow_dissector_target(flow_dissector,
529 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
530 target_container);
531
532 memcpy(&key_addrs->v6addrs, &iph->saddr,
533 sizeof(key_addrs->v6addrs));
534 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
535 }
536
537 if ((dissector_uses_key(flow_dissector,
538 FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
539 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
540 ip6_flowlabel(iph)) {
541 __be32 flow_label = ip6_flowlabel(iph);
542
543 if (dissector_uses_key(flow_dissector,
544 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
545 key_tags = skb_flow_dissector_target(flow_dissector,
546 FLOW_DISSECTOR_KEY_FLOW_LABEL,
547 target_container);
548 key_tags->flow_label = ntohl(flow_label);
549 }
550 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
551 goto out_good;
552 }
553
554 __skb_flow_dissect_ipv6(skb, flow_dissector,
555 target_container, data, iph);
556
557 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
558 goto out_good;
559
560 break;
561 }
562 case htons(ETH_P_8021AD):
563 case htons(ETH_P_8021Q): {
564 const struct vlan_hdr *vlan;
565 struct vlan_hdr _vlan;
566 bool vlan_tag_present = skb && skb_vlan_tag_present(skb);
567
568 if (vlan_tag_present)
569 proto = skb->protocol;
570
571 if (!vlan_tag_present || eth_type_vlan(skb->protocol)) {
572 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
573 data, hlen, &_vlan);
574 if (!vlan)
575 goto out_bad;
576 proto = vlan->h_vlan_encapsulated_proto;
577 nhoff += sizeof(*vlan);
578 if (skip_vlan)
579 goto proto_again;
580 }
581
582 skip_vlan = true;
583 if (dissector_uses_key(flow_dissector,
584 FLOW_DISSECTOR_KEY_VLAN)) {
585 key_vlan = skb_flow_dissector_target(flow_dissector,
586 FLOW_DISSECTOR_KEY_VLAN,
587 target_container);
588
589 if (vlan_tag_present) {
590 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
591 key_vlan->vlan_priority =
592 (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
593 } else {
594 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
595 VLAN_VID_MASK;
596 key_vlan->vlan_priority =
597 (ntohs(vlan->h_vlan_TCI) &
598 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
599 }
600 }
601
602 goto proto_again;
603 }
604 case htons(ETH_P_PPP_SES): {
605 struct {
606 struct pppoe_hdr hdr;
607 __be16 proto;
608 } *hdr, _hdr;
609 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
610 if (!hdr)
611 goto out_bad;
612 proto = hdr->proto;
613 nhoff += PPPOE_SES_HLEN;
614 switch (proto) {
615 case htons(PPP_IP):
616 goto ip;
617 case htons(PPP_IPV6):
618 goto ipv6;
619 default:
620 goto out_bad;
621 }
622 }
623 case htons(ETH_P_TIPC): {
624 struct {
625 __be32 pre[3];
626 __be32 srcnode;
627 } *hdr, _hdr;
628 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
629 if (!hdr)
630 goto out_bad;
631
632 if (dissector_uses_key(flow_dissector,
633 FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
634 key_addrs = skb_flow_dissector_target(flow_dissector,
635 FLOW_DISSECTOR_KEY_TIPC_ADDRS,
636 target_container);
637 key_addrs->tipcaddrs.srcnode = hdr->srcnode;
638 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
639 }
640 goto out_good;
641 }
642
643 case htons(ETH_P_MPLS_UC):
644 case htons(ETH_P_MPLS_MC):
645 mpls:
646 switch (__skb_flow_dissect_mpls(skb, flow_dissector,
647 target_container, data,
648 nhoff, hlen)) {
649 case FLOW_DISSECT_RET_OUT_GOOD:
650 goto out_good;
651 case FLOW_DISSECT_RET_OUT_BAD:
652 default:
653 goto out_bad;
654 }
655 case htons(ETH_P_FCOE):
656 if ((hlen - nhoff) < FCOE_HEADER_LEN)
657 goto out_bad;
658
659 nhoff += FCOE_HEADER_LEN;
660 goto out_good;
661
662 case htons(ETH_P_ARP):
663 case htons(ETH_P_RARP):
664 switch (__skb_flow_dissect_arp(skb, flow_dissector,
665 target_container, data,
666 nhoff, hlen)) {
667 case FLOW_DISSECT_RET_OUT_GOOD:
668 goto out_good;
669 case FLOW_DISSECT_RET_OUT_BAD:
670 default:
671 goto out_bad;
672 }
673 default:
674 goto out_bad;
675 }
676
677 ip_proto_again:
678 switch (ip_proto) {
679 case IPPROTO_GRE:
680 switch (__skb_flow_dissect_gre(skb, key_control, flow_dissector,
681 target_container, data,
682 &proto, &nhoff, &hlen, flags)) {
683 case FLOW_DISSECT_RET_OUT_GOOD:
684 goto out_good;
685 case FLOW_DISSECT_RET_OUT_BAD:
686 goto out_bad;
687 case FLOW_DISSECT_RET_OUT_PROTO_AGAIN:
688 goto proto_again;
689 }
690 case NEXTHDR_HOP:
691 case NEXTHDR_ROUTING:
692 case NEXTHDR_DEST: {
693 u8 _opthdr[2], *opthdr;
694
695 if (proto != htons(ETH_P_IPV6))
696 break;
697
698 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
699 data, hlen, &_opthdr);
700 if (!opthdr)
701 goto out_bad;
702
703 ip_proto = opthdr[0];
704 nhoff += (opthdr[1] + 1) << 3;
705
706 goto ip_proto_again;
707 }
708 case NEXTHDR_FRAGMENT: {
709 struct frag_hdr _fh, *fh;
710
711 if (proto != htons(ETH_P_IPV6))
712 break;
713
714 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
715 data, hlen, &_fh);
716
717 if (!fh)
718 goto out_bad;
719
720 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
721
722 nhoff += sizeof(_fh);
723 ip_proto = fh->nexthdr;
724
725 if (!(fh->frag_off & htons(IP6_OFFSET))) {
726 key_control->flags |= FLOW_DIS_FIRST_FRAG;
727 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
728 goto ip_proto_again;
729 }
730 goto out_good;
731 }
732 case IPPROTO_IPIP:
733 proto = htons(ETH_P_IP);
734
735 key_control->flags |= FLOW_DIS_ENCAPSULATION;
736 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
737 goto out_good;
738
739 goto ip;
740 case IPPROTO_IPV6:
741 proto = htons(ETH_P_IPV6);
742
743 key_control->flags |= FLOW_DIS_ENCAPSULATION;
744 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
745 goto out_good;
746
747 goto ipv6;
748 case IPPROTO_MPLS:
749 proto = htons(ETH_P_MPLS_UC);
750 goto mpls;
751 case IPPROTO_TCP:
752 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
753 data, nhoff, hlen);
754 break;
755 default:
756 break;
757 }
758
759 if (dissector_uses_key(flow_dissector,
760 FLOW_DISSECTOR_KEY_PORTS)) {
761 key_ports = skb_flow_dissector_target(flow_dissector,
762 FLOW_DISSECTOR_KEY_PORTS,
763 target_container);
764 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
765 data, hlen);
766 }
767
768 if (dissector_uses_key(flow_dissector,
769 FLOW_DISSECTOR_KEY_ICMP)) {
770 key_icmp = skb_flow_dissector_target(flow_dissector,
771 FLOW_DISSECTOR_KEY_ICMP,
772 target_container);
773 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
774 }
775
776 out_good:
777 ret = true;
778
779 key_control->thoff = (u16)nhoff;
780 out:
781 key_basic->n_proto = proto;
782 key_basic->ip_proto = ip_proto;
783
784 return ret;
785
786 out_bad:
787 ret = false;
788 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
789 goto out;
790 }
791 EXPORT_SYMBOL(__skb_flow_dissect);
792
793 static u32 hashrnd __read_mostly;
794 static __always_inline void __flow_hash_secret_init(void)
795 {
796 net_get_random_once(&hashrnd, sizeof(hashrnd));
797 }
798
799 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
800 u32 keyval)
801 {
802 return jhash2(words, length, keyval);
803 }
804
805 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
806 {
807 const void *p = flow;
808
809 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
810 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
811 }
812
813 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
814 {
815 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
816 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
817 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
818 sizeof(*flow) - sizeof(flow->addrs));
819
820 switch (flow->control.addr_type) {
821 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
822 diff -= sizeof(flow->addrs.v4addrs);
823 break;
824 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
825 diff -= sizeof(flow->addrs.v6addrs);
826 break;
827 case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
828 diff -= sizeof(flow->addrs.tipcaddrs);
829 break;
830 }
831 return (sizeof(*flow) - diff) / sizeof(u32);
832 }
833
834 __be32 flow_get_u32_src(const struct flow_keys *flow)
835 {
836 switch (flow->control.addr_type) {
837 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
838 return flow->addrs.v4addrs.src;
839 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
840 return (__force __be32)ipv6_addr_hash(
841 &flow->addrs.v6addrs.src);
842 case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
843 return flow->addrs.tipcaddrs.srcnode;
844 default:
845 return 0;
846 }
847 }
848 EXPORT_SYMBOL(flow_get_u32_src);
849
850 __be32 flow_get_u32_dst(const struct flow_keys *flow)
851 {
852 switch (flow->control.addr_type) {
853 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
854 return flow->addrs.v4addrs.dst;
855 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
856 return (__force __be32)ipv6_addr_hash(
857 &flow->addrs.v6addrs.dst);
858 default:
859 return 0;
860 }
861 }
862 EXPORT_SYMBOL(flow_get_u32_dst);
863
864 static inline void __flow_hash_consistentify(struct flow_keys *keys)
865 {
866 int addr_diff, i;
867
868 switch (keys->control.addr_type) {
869 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
870 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
871 (__force u32)keys->addrs.v4addrs.src;
872 if ((addr_diff < 0) ||
873 (addr_diff == 0 &&
874 ((__force u16)keys->ports.dst <
875 (__force u16)keys->ports.src))) {
876 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
877 swap(keys->ports.src, keys->ports.dst);
878 }
879 break;
880 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
881 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
882 &keys->addrs.v6addrs.src,
883 sizeof(keys->addrs.v6addrs.dst));
884 if ((addr_diff < 0) ||
885 (addr_diff == 0 &&
886 ((__force u16)keys->ports.dst <
887 (__force u16)keys->ports.src))) {
888 for (i = 0; i < 4; i++)
889 swap(keys->addrs.v6addrs.src.s6_addr32[i],
890 keys->addrs.v6addrs.dst.s6_addr32[i]);
891 swap(keys->ports.src, keys->ports.dst);
892 }
893 break;
894 }
895 }
896
897 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
898 {
899 u32 hash;
900
901 __flow_hash_consistentify(keys);
902
903 hash = __flow_hash_words(flow_keys_hash_start(keys),
904 flow_keys_hash_length(keys), keyval);
905 if (!hash)
906 hash = 1;
907
908 return hash;
909 }
910
911 u32 flow_hash_from_keys(struct flow_keys *keys)
912 {
913 __flow_hash_secret_init();
914 return __flow_hash_from_keys(keys, hashrnd);
915 }
916 EXPORT_SYMBOL(flow_hash_from_keys);
917
918 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
919 struct flow_keys *keys, u32 keyval)
920 {
921 skb_flow_dissect_flow_keys(skb, keys,
922 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
923
924 return __flow_hash_from_keys(keys, keyval);
925 }
926
927 struct _flow_keys_digest_data {
928 __be16 n_proto;
929 u8 ip_proto;
930 u8 padding;
931 __be32 ports;
932 __be32 src;
933 __be32 dst;
934 };
935
936 void make_flow_keys_digest(struct flow_keys_digest *digest,
937 const struct flow_keys *flow)
938 {
939 struct _flow_keys_digest_data *data =
940 (struct _flow_keys_digest_data *)digest;
941
942 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
943
944 memset(digest, 0, sizeof(*digest));
945
946 data->n_proto = flow->basic.n_proto;
947 data->ip_proto = flow->basic.ip_proto;
948 data->ports = flow->ports.ports;
949 data->src = flow->addrs.v4addrs.src;
950 data->dst = flow->addrs.v4addrs.dst;
951 }
952 EXPORT_SYMBOL(make_flow_keys_digest);
953
954 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
955
956 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
957 {
958 struct flow_keys keys;
959
960 __flow_hash_secret_init();
961
962 memset(&keys, 0, sizeof(keys));
963 __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
964 NULL, 0, 0, 0,
965 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
966
967 return __flow_hash_from_keys(&keys, hashrnd);
968 }
969 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
970
971 /**
972 * __skb_get_hash: calculate a flow hash
973 * @skb: sk_buff to calculate flow hash from
974 *
975 * This function calculates a flow hash based on src/dst addresses
976 * and src/dst port numbers. Sets hash in skb to non-zero hash value
977 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
978 * if hash is a canonical 4-tuple hash over transport ports.
979 */
980 void __skb_get_hash(struct sk_buff *skb)
981 {
982 struct flow_keys keys;
983 u32 hash;
984
985 __flow_hash_secret_init();
986
987 hash = ___skb_get_hash(skb, &keys, hashrnd);
988
989 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
990 }
991 EXPORT_SYMBOL(__skb_get_hash);
992
993 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
994 {
995 struct flow_keys keys;
996
997 return ___skb_get_hash(skb, &keys, perturb);
998 }
999 EXPORT_SYMBOL(skb_get_hash_perturb);
1000
1001 __u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
1002 {
1003 struct flow_keys keys;
1004
1005 memset(&keys, 0, sizeof(keys));
1006
1007 memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
1008 sizeof(keys.addrs.v6addrs.src));
1009 memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
1010 sizeof(keys.addrs.v6addrs.dst));
1011 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1012 keys.ports.src = fl6->fl6_sport;
1013 keys.ports.dst = fl6->fl6_dport;
1014 keys.keyid.keyid = fl6->fl6_gre_key;
1015 keys.tags.flow_label = (__force u32)fl6->flowlabel;
1016 keys.basic.ip_proto = fl6->flowi6_proto;
1017
1018 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
1019 flow_keys_have_l4(&keys));
1020
1021 return skb->hash;
1022 }
1023 EXPORT_SYMBOL(__skb_get_hash_flowi6);
1024
1025 __u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
1026 {
1027 struct flow_keys keys;
1028
1029 memset(&keys, 0, sizeof(keys));
1030
1031 keys.addrs.v4addrs.src = fl4->saddr;
1032 keys.addrs.v4addrs.dst = fl4->daddr;
1033 keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1034 keys.ports.src = fl4->fl4_sport;
1035 keys.ports.dst = fl4->fl4_dport;
1036 keys.keyid.keyid = fl4->fl4_gre_key;
1037 keys.basic.ip_proto = fl4->flowi4_proto;
1038
1039 __skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
1040 flow_keys_have_l4(&keys));
1041
1042 return skb->hash;
1043 }
1044 EXPORT_SYMBOL(__skb_get_hash_flowi4);
1045
1046 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1047 const struct flow_keys *keys, int hlen)
1048 {
1049 u32 poff = keys->control.thoff;
1050
1051 /* skip L4 headers for fragments after the first */
1052 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1053 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1054 return poff;
1055
1056 switch (keys->basic.ip_proto) {
1057 case IPPROTO_TCP: {
1058 /* access doff as u8 to avoid unaligned access */
1059 const u8 *doff;
1060 u8 _doff;
1061
1062 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1063 data, hlen, &_doff);
1064 if (!doff)
1065 return poff;
1066
1067 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1068 break;
1069 }
1070 case IPPROTO_UDP:
1071 case IPPROTO_UDPLITE:
1072 poff += sizeof(struct udphdr);
1073 break;
1074 /* For the rest, we do not really care about header
1075 * extensions at this point for now.
1076 */
1077 case IPPROTO_ICMP:
1078 poff += sizeof(struct icmphdr);
1079 break;
1080 case IPPROTO_ICMPV6:
1081 poff += sizeof(struct icmp6hdr);
1082 break;
1083 case IPPROTO_IGMP:
1084 poff += sizeof(struct igmphdr);
1085 break;
1086 case IPPROTO_DCCP:
1087 poff += sizeof(struct dccp_hdr);
1088 break;
1089 case IPPROTO_SCTP:
1090 poff += sizeof(struct sctphdr);
1091 break;
1092 }
1093
1094 return poff;
1095 }
1096
1097 /**
1098 * skb_get_poff - get the offset to the payload
1099 * @skb: sk_buff to get the payload offset from
1100 *
1101 * The function will get the offset to the payload as far as it could
1102 * be dissected. The main user is currently BPF, so that we can dynamically
1103 * truncate packets without needing to push actual payload to the user
1104 * space and can analyze headers only, instead.
1105 */
1106 u32 skb_get_poff(const struct sk_buff *skb)
1107 {
1108 struct flow_keys keys;
1109
1110 if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
1111 return 0;
1112
1113 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1114 }
1115
1116 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1117 {
1118 memset(keys, 0, sizeof(*keys));
1119
1120 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1121 sizeof(keys->addrs.v6addrs.src));
1122 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1123 sizeof(keys->addrs.v6addrs.dst));
1124 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1125 keys->ports.src = fl6->fl6_sport;
1126 keys->ports.dst = fl6->fl6_dport;
1127 keys->keyid.keyid = fl6->fl6_gre_key;
1128 keys->tags.flow_label = (__force u32)fl6->flowlabel;
1129 keys->basic.ip_proto = fl6->flowi6_proto;
1130
1131 return flow_hash_from_keys(keys);
1132 }
1133 EXPORT_SYMBOL(__get_hash_from_flowi6);
1134
1135 __u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
1136 {
1137 memset(keys, 0, sizeof(*keys));
1138
1139 keys->addrs.v4addrs.src = fl4->saddr;
1140 keys->addrs.v4addrs.dst = fl4->daddr;
1141 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1142 keys->ports.src = fl4->fl4_sport;
1143 keys->ports.dst = fl4->fl4_dport;
1144 keys->keyid.keyid = fl4->fl4_gre_key;
1145 keys->basic.ip_proto = fl4->flowi4_proto;
1146
1147 return flow_hash_from_keys(keys);
1148 }
1149 EXPORT_SYMBOL(__get_hash_from_flowi4);
1150
1151 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1152 {
1153 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1154 .offset = offsetof(struct flow_keys, control),
1155 },
1156 {
1157 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1158 .offset = offsetof(struct flow_keys, basic),
1159 },
1160 {
1161 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1162 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1163 },
1164 {
1165 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1166 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1167 },
1168 {
1169 .key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
1170 .offset = offsetof(struct flow_keys, addrs.tipcaddrs),
1171 },
1172 {
1173 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1174 .offset = offsetof(struct flow_keys, ports),
1175 },
1176 {
1177 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1178 .offset = offsetof(struct flow_keys, vlan),
1179 },
1180 {
1181 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1182 .offset = offsetof(struct flow_keys, tags),
1183 },
1184 {
1185 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1186 .offset = offsetof(struct flow_keys, keyid),
1187 },
1188 };
1189
1190 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1191 {
1192 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1193 .offset = offsetof(struct flow_keys, control),
1194 },
1195 {
1196 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1197 .offset = offsetof(struct flow_keys, basic),
1198 },
1199 {
1200 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1201 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1202 },
1203 {
1204 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1205 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1206 },
1207 {
1208 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1209 .offset = offsetof(struct flow_keys, ports),
1210 },
1211 };
1212
1213 static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
1214 {
1215 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1216 .offset = offsetof(struct flow_keys, control),
1217 },
1218 {
1219 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1220 .offset = offsetof(struct flow_keys, basic),
1221 },
1222 };
1223
1224 struct flow_dissector flow_keys_dissector __read_mostly;
1225 EXPORT_SYMBOL(flow_keys_dissector);
1226
1227 struct flow_dissector flow_keys_buf_dissector __read_mostly;
1228
1229 static int __init init_default_flow_dissectors(void)
1230 {
1231 skb_flow_dissector_init(&flow_keys_dissector,
1232 flow_keys_dissector_keys,
1233 ARRAY_SIZE(flow_keys_dissector_keys));
1234 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1235 flow_keys_dissector_symmetric_keys,
1236 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1237 skb_flow_dissector_init(&flow_keys_buf_dissector,
1238 flow_keys_buf_dissector_keys,
1239 ARRAY_SIZE(flow_keys_buf_dissector_keys));
1240 return 0;
1241 }
1242
1243 core_initcall(init_default_flow_dissectors);
Linux with added FPC-III support