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