1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | #include <linux/kernel.h> |
3 | #include <linux/skbuff.h> |
4 | #include <linux/export.h> |
5 | #include <linux/ip.h> |
6 | #include <linux/ipv6.h> |
7 | #include <linux/if_vlan.h> |
8 | #include <linux/filter.h> |
9 | #include <net/dsa.h> |
10 | #include <net/dst_metadata.h> |
11 | #include <net/ip.h> |
12 | #include <net/ipv6.h> |
13 | #include <net/gre.h> |
14 | #include <net/pptp.h> |
15 | #include <net/tipc.h> |
16 | #include <linux/igmp.h> |
17 | #include <linux/icmp.h> |
18 | #include <linux/sctp.h> |
19 | #include <linux/dccp.h> |
20 | #include <linux/if_tunnel.h> |
21 | #include <linux/if_pppox.h> |
22 | #include <linux/ppp_defs.h> |
23 | #include <linux/stddef.h> |
24 | #include <linux/if_ether.h> |
25 | #include <linux/if_hsr.h> |
26 | #include <linux/mpls.h> |
27 | #include <linux/tcp.h> |
28 | #include <linux/ptp_classify.h> |
29 | #include <net/flow_dissector.h> |
30 | #include <net/pkt_cls.h> |
31 | #include <scsi/fc/fc_fcoe.h> |
32 | #include <uapi/linux/batadv_packet.h> |
33 | #include <linux/bpf.h> |
34 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
35 | #include <net/netfilter/nf_conntrack_core.h> |
36 | #include <net/netfilter/nf_conntrack_labels.h> |
37 | #endif |
38 | #include <linux/bpf-netns.h> |
39 | |
40 | static void dissector_set_key(struct flow_dissector *flow_dissector, |
41 | enum flow_dissector_key_id key_id) |
42 | { |
43 | flow_dissector->used_keys |= (1ULL << key_id); |
44 | } |
45 | |
46 | void skb_flow_dissector_init(struct flow_dissector *flow_dissector, |
47 | const struct flow_dissector_key *key, |
48 | unsigned int key_count) |
49 | { |
50 | unsigned int i; |
51 | |
52 | memset(flow_dissector, 0, sizeof(*flow_dissector)); |
53 | |
54 | for (i = 0; i < key_count; i++, key++) { |
55 | /* User should make sure that every key target offset is within |
56 | * boundaries of unsigned short. |
57 | */ |
58 | BUG_ON(key->offset > USHRT_MAX); |
59 | BUG_ON(dissector_uses_key(flow_dissector, |
60 | key->key_id)); |
61 | |
62 | dissector_set_key(flow_dissector, key_id: key->key_id); |
63 | flow_dissector->offset[key->key_id] = key->offset; |
64 | } |
65 | |
66 | /* Ensure that the dissector always includes control and basic key. |
67 | * That way we are able to avoid handling lack of these in fast path. |
68 | */ |
69 | BUG_ON(!dissector_uses_key(flow_dissector, |
70 | FLOW_DISSECTOR_KEY_CONTROL)); |
71 | BUG_ON(!dissector_uses_key(flow_dissector, |
72 | FLOW_DISSECTOR_KEY_BASIC)); |
73 | } |
74 | EXPORT_SYMBOL(skb_flow_dissector_init); |
75 | |
76 | #ifdef CONFIG_BPF_SYSCALL |
77 | int flow_dissector_bpf_prog_attach_check(struct net *net, |
78 | struct bpf_prog *prog) |
79 | { |
80 | enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; |
81 | |
82 | if (net == &init_net) { |
83 | /* BPF flow dissector in the root namespace overrides |
84 | * any per-net-namespace one. When attaching to root, |
85 | * make sure we don't have any BPF program attached |
86 | * to the non-root namespaces. |
87 | */ |
88 | struct net *ns; |
89 | |
90 | for_each_net(ns) { |
91 | if (ns == &init_net) |
92 | continue; |
93 | if (rcu_access_pointer(ns->bpf.run_array[type])) |
94 | return -EEXIST; |
95 | } |
96 | } else { |
97 | /* Make sure root flow dissector is not attached |
98 | * when attaching to the non-root namespace. |
99 | */ |
100 | if (rcu_access_pointer(init_net.bpf.run_array[type])) |
101 | return -EEXIST; |
102 | } |
103 | |
104 | return 0; |
105 | } |
106 | #endif /* CONFIG_BPF_SYSCALL */ |
107 | |
108 | /** |
109 | * __skb_flow_get_ports - extract the upper layer ports and return them |
110 | * @skb: sk_buff to extract the ports from |
111 | * @thoff: transport header offset |
112 | * @ip_proto: protocol for which to get port offset |
113 | * @data: raw buffer pointer to the packet, if NULL use skb->data |
114 | * @hlen: packet header length, if @data is NULL use skb_headlen(skb) |
115 | * |
116 | * The function will try to retrieve the ports at offset thoff + poff where poff |
117 | * is the protocol port offset returned from proto_ports_offset |
118 | */ |
119 | __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto, |
120 | const void *data, int hlen) |
121 | { |
122 | int poff = proto_ports_offset(proto: ip_proto); |
123 | |
124 | if (!data) { |
125 | data = skb->data; |
126 | hlen = skb_headlen(skb); |
127 | } |
128 | |
129 | if (poff >= 0) { |
130 | __be32 *ports, _ports; |
131 | |
132 | ports = __skb_header_pointer(skb, offset: thoff + poff, |
133 | len: sizeof(_ports), data, hlen, buffer: &_ports); |
134 | if (ports) |
135 | return *ports; |
136 | } |
137 | |
138 | return 0; |
139 | } |
140 | EXPORT_SYMBOL(__skb_flow_get_ports); |
141 | |
142 | static bool icmp_has_id(u8 type) |
143 | { |
144 | switch (type) { |
145 | case ICMP_ECHO: |
146 | case ICMP_ECHOREPLY: |
147 | case ICMP_TIMESTAMP: |
148 | case ICMP_TIMESTAMPREPLY: |
149 | case ICMPV6_ECHO_REQUEST: |
150 | case ICMPV6_ECHO_REPLY: |
151 | return true; |
152 | } |
153 | |
154 | return false; |
155 | } |
156 | |
157 | /** |
158 | * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields |
159 | * @skb: sk_buff to extract from |
160 | * @key_icmp: struct flow_dissector_key_icmp to fill |
161 | * @data: raw buffer pointer to the packet |
162 | * @thoff: offset to extract at |
163 | * @hlen: packet header length |
164 | */ |
165 | void skb_flow_get_icmp_tci(const struct sk_buff *skb, |
166 | struct flow_dissector_key_icmp *key_icmp, |
167 | const void *data, int thoff, int hlen) |
168 | { |
169 | struct icmphdr *ih, _ih; |
170 | |
171 | ih = __skb_header_pointer(skb, offset: thoff, len: sizeof(_ih), data, hlen, buffer: &_ih); |
172 | if (!ih) |
173 | return; |
174 | |
175 | key_icmp->type = ih->type; |
176 | key_icmp->code = ih->code; |
177 | |
178 | /* As we use 0 to signal that the Id field is not present, |
179 | * avoid confusion with packets without such field |
180 | */ |
181 | if (icmp_has_id(type: ih->type)) |
182 | key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1; |
183 | else |
184 | key_icmp->id = 0; |
185 | } |
186 | EXPORT_SYMBOL(skb_flow_get_icmp_tci); |
187 | |
188 | /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet |
189 | * using skb_flow_get_icmp_tci(). |
190 | */ |
191 | static void __skb_flow_dissect_icmp(const struct sk_buff *skb, |
192 | struct flow_dissector *flow_dissector, |
193 | void *target_container, const void *data, |
194 | int thoff, int hlen) |
195 | { |
196 | struct flow_dissector_key_icmp *key_icmp; |
197 | |
198 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ICMP)) |
199 | return; |
200 | |
201 | key_icmp = skb_flow_dissector_target(flow_dissector, |
202 | key_id: FLOW_DISSECTOR_KEY_ICMP, |
203 | target_container); |
204 | |
205 | skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen); |
206 | } |
207 | |
208 | static void __skb_flow_dissect_ah(const struct sk_buff *skb, |
209 | struct flow_dissector *flow_dissector, |
210 | void *target_container, const void *data, |
211 | int nhoff, int hlen) |
212 | { |
213 | struct flow_dissector_key_ipsec *key_ah; |
214 | struct ip_auth_hdr _hdr, *hdr; |
215 | |
216 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_IPSEC)) |
217 | return; |
218 | |
219 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, hlen, buffer: &_hdr); |
220 | if (!hdr) |
221 | return; |
222 | |
223 | key_ah = skb_flow_dissector_target(flow_dissector, |
224 | key_id: FLOW_DISSECTOR_KEY_IPSEC, |
225 | target_container); |
226 | |
227 | key_ah->spi = hdr->spi; |
228 | } |
229 | |
230 | static void __skb_flow_dissect_esp(const struct sk_buff *skb, |
231 | struct flow_dissector *flow_dissector, |
232 | void *target_container, const void *data, |
233 | int nhoff, int hlen) |
234 | { |
235 | struct flow_dissector_key_ipsec *key_esp; |
236 | struct ip_esp_hdr _hdr, *hdr; |
237 | |
238 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_IPSEC)) |
239 | return; |
240 | |
241 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, hlen, buffer: &_hdr); |
242 | if (!hdr) |
243 | return; |
244 | |
245 | key_esp = skb_flow_dissector_target(flow_dissector, |
246 | key_id: FLOW_DISSECTOR_KEY_IPSEC, |
247 | target_container); |
248 | |
249 | key_esp->spi = hdr->spi; |
250 | } |
251 | |
252 | static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb, |
253 | struct flow_dissector *flow_dissector, |
254 | void *target_container, const void *data, |
255 | int nhoff, int hlen) |
256 | { |
257 | struct flow_dissector_key_l2tpv3 *key_l2tpv3; |
258 | struct { |
259 | __be32 session_id; |
260 | } *hdr, _hdr; |
261 | |
262 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_L2TPV3)) |
263 | return; |
264 | |
265 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, hlen, buffer: &_hdr); |
266 | if (!hdr) |
267 | return; |
268 | |
269 | key_l2tpv3 = skb_flow_dissector_target(flow_dissector, |
270 | key_id: FLOW_DISSECTOR_KEY_L2TPV3, |
271 | target_container); |
272 | |
273 | key_l2tpv3->session_id = hdr->session_id; |
274 | } |
275 | |
276 | void skb_flow_dissect_meta(const struct sk_buff *skb, |
277 | struct flow_dissector *flow_dissector, |
278 | void *target_container) |
279 | { |
280 | struct flow_dissector_key_meta *meta; |
281 | |
282 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_META)) |
283 | return; |
284 | |
285 | meta = skb_flow_dissector_target(flow_dissector, |
286 | key_id: FLOW_DISSECTOR_KEY_META, |
287 | target_container); |
288 | meta->ingress_ifindex = skb->skb_iif; |
289 | #if IS_ENABLED(CONFIG_NET_TC_SKB_EXT) |
290 | if (tc_skb_ext_tc_enabled()) { |
291 | struct tc_skb_ext *ext; |
292 | |
293 | ext = skb_ext_find(skb, id: TC_SKB_EXT); |
294 | if (ext) |
295 | meta->l2_miss = ext->l2_miss; |
296 | } |
297 | #endif |
298 | } |
299 | EXPORT_SYMBOL(skb_flow_dissect_meta); |
300 | |
301 | static void |
302 | skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type, |
303 | struct flow_dissector *flow_dissector, |
304 | void *target_container) |
305 | { |
306 | struct flow_dissector_key_control *ctrl; |
307 | |
308 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ENC_CONTROL)) |
309 | return; |
310 | |
311 | ctrl = skb_flow_dissector_target(flow_dissector, |
312 | key_id: FLOW_DISSECTOR_KEY_ENC_CONTROL, |
313 | target_container); |
314 | ctrl->addr_type = type; |
315 | } |
316 | |
317 | void |
318 | skb_flow_dissect_ct(const struct sk_buff *skb, |
319 | struct flow_dissector *flow_dissector, |
320 | void *target_container, u16 *ctinfo_map, |
321 | size_t mapsize, bool post_ct, u16 zone) |
322 | { |
323 | #if IS_ENABLED(CONFIG_NF_CONNTRACK) |
324 | struct flow_dissector_key_ct *key; |
325 | enum ip_conntrack_info ctinfo; |
326 | struct nf_conn_labels *cl; |
327 | struct nf_conn *ct; |
328 | |
329 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_CT)) |
330 | return; |
331 | |
332 | ct = nf_ct_get(skb, ctinfo: &ctinfo); |
333 | if (!ct && !post_ct) |
334 | return; |
335 | |
336 | key = skb_flow_dissector_target(flow_dissector, |
337 | key_id: FLOW_DISSECTOR_KEY_CT, |
338 | target_container); |
339 | |
340 | if (!ct) { |
341 | key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED | |
342 | TCA_FLOWER_KEY_CT_FLAGS_INVALID; |
343 | key->ct_zone = zone; |
344 | return; |
345 | } |
346 | |
347 | if (ctinfo < mapsize) |
348 | key->ct_state = ctinfo_map[ctinfo]; |
349 | #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) |
350 | key->ct_zone = ct->zone.id; |
351 | #endif |
352 | #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) |
353 | key->ct_mark = READ_ONCE(ct->mark); |
354 | #endif |
355 | |
356 | cl = nf_ct_labels_find(ct); |
357 | if (cl) |
358 | memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels)); |
359 | #endif /* CONFIG_NF_CONNTRACK */ |
360 | } |
361 | EXPORT_SYMBOL(skb_flow_dissect_ct); |
362 | |
363 | void |
364 | skb_flow_dissect_tunnel_info(const struct sk_buff *skb, |
365 | struct flow_dissector *flow_dissector, |
366 | void *target_container) |
367 | { |
368 | struct ip_tunnel_info *info; |
369 | struct ip_tunnel_key *key; |
370 | |
371 | /* A quick check to see if there might be something to do. */ |
372 | if (!dissector_uses_key(flow_dissector, |
373 | key_id: FLOW_DISSECTOR_KEY_ENC_KEYID) && |
374 | !dissector_uses_key(flow_dissector, |
375 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) && |
376 | !dissector_uses_key(flow_dissector, |
377 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) && |
378 | !dissector_uses_key(flow_dissector, |
379 | key_id: FLOW_DISSECTOR_KEY_ENC_CONTROL) && |
380 | !dissector_uses_key(flow_dissector, |
381 | key_id: FLOW_DISSECTOR_KEY_ENC_PORTS) && |
382 | !dissector_uses_key(flow_dissector, |
383 | key_id: FLOW_DISSECTOR_KEY_ENC_IP) && |
384 | !dissector_uses_key(flow_dissector, |
385 | key_id: FLOW_DISSECTOR_KEY_ENC_OPTS)) |
386 | return; |
387 | |
388 | info = skb_tunnel_info(skb); |
389 | if (!info) |
390 | return; |
391 | |
392 | key = &info->key; |
393 | |
394 | switch (ip_tunnel_info_af(tun_info: info)) { |
395 | case AF_INET: |
396 | skb_flow_dissect_set_enc_addr_type(type: FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
397 | flow_dissector, |
398 | target_container); |
399 | if (dissector_uses_key(flow_dissector, |
400 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) { |
401 | struct flow_dissector_key_ipv4_addrs *ipv4; |
402 | |
403 | ipv4 = skb_flow_dissector_target(flow_dissector, |
404 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, |
405 | target_container); |
406 | ipv4->src = key->u.ipv4.src; |
407 | ipv4->dst = key->u.ipv4.dst; |
408 | } |
409 | break; |
410 | case AF_INET6: |
411 | skb_flow_dissect_set_enc_addr_type(type: FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
412 | flow_dissector, |
413 | target_container); |
414 | if (dissector_uses_key(flow_dissector, |
415 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) { |
416 | struct flow_dissector_key_ipv6_addrs *ipv6; |
417 | |
418 | ipv6 = skb_flow_dissector_target(flow_dissector, |
419 | key_id: FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, |
420 | target_container); |
421 | ipv6->src = key->u.ipv6.src; |
422 | ipv6->dst = key->u.ipv6.dst; |
423 | } |
424 | break; |
425 | } |
426 | |
427 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ENC_KEYID)) { |
428 | struct flow_dissector_key_keyid *keyid; |
429 | |
430 | keyid = skb_flow_dissector_target(flow_dissector, |
431 | key_id: FLOW_DISSECTOR_KEY_ENC_KEYID, |
432 | target_container); |
433 | keyid->keyid = tunnel_id_to_key32(tun_id: key->tun_id); |
434 | } |
435 | |
436 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ENC_PORTS)) { |
437 | struct flow_dissector_key_ports *tp; |
438 | |
439 | tp = skb_flow_dissector_target(flow_dissector, |
440 | key_id: FLOW_DISSECTOR_KEY_ENC_PORTS, |
441 | target_container); |
442 | tp->src = key->tp_src; |
443 | tp->dst = key->tp_dst; |
444 | } |
445 | |
446 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ENC_IP)) { |
447 | struct flow_dissector_key_ip *ip; |
448 | |
449 | ip = skb_flow_dissector_target(flow_dissector, |
450 | key_id: FLOW_DISSECTOR_KEY_ENC_IP, |
451 | target_container); |
452 | ip->tos = key->tos; |
453 | ip->ttl = key->ttl; |
454 | } |
455 | |
456 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ENC_OPTS)) { |
457 | struct flow_dissector_key_enc_opts *enc_opt; |
458 | |
459 | enc_opt = skb_flow_dissector_target(flow_dissector, |
460 | key_id: FLOW_DISSECTOR_KEY_ENC_OPTS, |
461 | target_container); |
462 | |
463 | if (info->options_len) { |
464 | enc_opt->len = info->options_len; |
465 | ip_tunnel_info_opts_get(to: enc_opt->data, info); |
466 | enc_opt->dst_opt_type = info->key.tun_flags & |
467 | TUNNEL_OPTIONS_PRESENT; |
468 | } |
469 | } |
470 | } |
471 | EXPORT_SYMBOL(skb_flow_dissect_tunnel_info); |
472 | |
473 | void skb_flow_dissect_hash(const struct sk_buff *skb, |
474 | struct flow_dissector *flow_dissector, |
475 | void *target_container) |
476 | { |
477 | struct flow_dissector_key_hash *key; |
478 | |
479 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_HASH)) |
480 | return; |
481 | |
482 | key = skb_flow_dissector_target(flow_dissector, |
483 | key_id: FLOW_DISSECTOR_KEY_HASH, |
484 | target_container); |
485 | |
486 | key->hash = skb_get_hash_raw(skb); |
487 | } |
488 | EXPORT_SYMBOL(skb_flow_dissect_hash); |
489 | |
490 | static enum flow_dissect_ret |
491 | __skb_flow_dissect_mpls(const struct sk_buff *skb, |
492 | struct flow_dissector *flow_dissector, |
493 | void *target_container, const void *data, int nhoff, |
494 | int hlen, int lse_index, bool *entropy_label) |
495 | { |
496 | struct mpls_label *hdr, _hdr; |
497 | u32 entry, label, bos; |
498 | |
499 | if (!dissector_uses_key(flow_dissector, |
500 | key_id: FLOW_DISSECTOR_KEY_MPLS_ENTROPY) && |
501 | !dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_MPLS)) |
502 | return FLOW_DISSECT_RET_OUT_GOOD; |
503 | |
504 | if (lse_index >= FLOW_DIS_MPLS_MAX) |
505 | return FLOW_DISSECT_RET_OUT_GOOD; |
506 | |
507 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, |
508 | hlen, buffer: &_hdr); |
509 | if (!hdr) |
510 | return FLOW_DISSECT_RET_OUT_BAD; |
511 | |
512 | entry = ntohl(hdr->entry); |
513 | label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT; |
514 | bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT; |
515 | |
516 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_MPLS)) { |
517 | struct flow_dissector_key_mpls *key_mpls; |
518 | struct flow_dissector_mpls_lse *lse; |
519 | |
520 | key_mpls = skb_flow_dissector_target(flow_dissector, |
521 | key_id: FLOW_DISSECTOR_KEY_MPLS, |
522 | target_container); |
523 | lse = &key_mpls->ls[lse_index]; |
524 | |
525 | lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT; |
526 | lse->mpls_bos = bos; |
527 | lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT; |
528 | lse->mpls_label = label; |
529 | dissector_set_mpls_lse(mpls: key_mpls, lse_index); |
530 | } |
531 | |
532 | if (*entropy_label && |
533 | dissector_uses_key(flow_dissector, |
534 | key_id: FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) { |
535 | struct flow_dissector_key_keyid *key_keyid; |
536 | |
537 | key_keyid = skb_flow_dissector_target(flow_dissector, |
538 | key_id: FLOW_DISSECTOR_KEY_MPLS_ENTROPY, |
539 | target_container); |
540 | key_keyid->keyid = cpu_to_be32(label); |
541 | } |
542 | |
543 | *entropy_label = label == MPLS_LABEL_ENTROPY; |
544 | |
545 | return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN; |
546 | } |
547 | |
548 | static enum flow_dissect_ret |
549 | __skb_flow_dissect_arp(const struct sk_buff *skb, |
550 | struct flow_dissector *flow_dissector, |
551 | void *target_container, const void *data, |
552 | int nhoff, int hlen) |
553 | { |
554 | struct flow_dissector_key_arp *key_arp; |
555 | struct { |
556 | unsigned char ar_sha[ETH_ALEN]; |
557 | unsigned char ar_sip[4]; |
558 | unsigned char ar_tha[ETH_ALEN]; |
559 | unsigned char ar_tip[4]; |
560 | } *arp_eth, _arp_eth; |
561 | const struct arphdr *arp; |
562 | struct arphdr _arp; |
563 | |
564 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_ARP)) |
565 | return FLOW_DISSECT_RET_OUT_GOOD; |
566 | |
567 | arp = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_arp), data, |
568 | hlen, buffer: &_arp); |
569 | if (!arp) |
570 | return FLOW_DISSECT_RET_OUT_BAD; |
571 | |
572 | if (arp->ar_hrd != htons(ARPHRD_ETHER) || |
573 | arp->ar_pro != htons(ETH_P_IP) || |
574 | arp->ar_hln != ETH_ALEN || |
575 | arp->ar_pln != 4 || |
576 | (arp->ar_op != htons(ARPOP_REPLY) && |
577 | arp->ar_op != htons(ARPOP_REQUEST))) |
578 | return FLOW_DISSECT_RET_OUT_BAD; |
579 | |
580 | arp_eth = __skb_header_pointer(skb, offset: nhoff + sizeof(_arp), |
581 | len: sizeof(_arp_eth), data, |
582 | hlen, buffer: &_arp_eth); |
583 | if (!arp_eth) |
584 | return FLOW_DISSECT_RET_OUT_BAD; |
585 | |
586 | key_arp = skb_flow_dissector_target(flow_dissector, |
587 | key_id: FLOW_DISSECTOR_KEY_ARP, |
588 | target_container); |
589 | |
590 | memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip)); |
591 | memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip)); |
592 | |
593 | /* Only store the lower byte of the opcode; |
594 | * this covers ARPOP_REPLY and ARPOP_REQUEST. |
595 | */ |
596 | key_arp->op = ntohs(arp->ar_op) & 0xff; |
597 | |
598 | ether_addr_copy(dst: key_arp->sha, src: arp_eth->ar_sha); |
599 | ether_addr_copy(dst: key_arp->tha, src: arp_eth->ar_tha); |
600 | |
601 | return FLOW_DISSECT_RET_OUT_GOOD; |
602 | } |
603 | |
604 | static enum flow_dissect_ret |
605 | __skb_flow_dissect_cfm(const struct sk_buff *skb, |
606 | struct flow_dissector *flow_dissector, |
607 | void *target_container, const void *data, |
608 | int nhoff, int hlen) |
609 | { |
610 | struct flow_dissector_key_cfm *key, *hdr, _hdr; |
611 | |
612 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_CFM)) |
613 | return FLOW_DISSECT_RET_OUT_GOOD; |
614 | |
615 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(*key), data, hlen, buffer: &_hdr); |
616 | if (!hdr) |
617 | return FLOW_DISSECT_RET_OUT_BAD; |
618 | |
619 | key = skb_flow_dissector_target(flow_dissector, key_id: FLOW_DISSECTOR_KEY_CFM, |
620 | target_container); |
621 | |
622 | key->mdl_ver = hdr->mdl_ver; |
623 | key->opcode = hdr->opcode; |
624 | |
625 | return FLOW_DISSECT_RET_OUT_GOOD; |
626 | } |
627 | |
628 | static enum flow_dissect_ret |
629 | __skb_flow_dissect_gre(const struct sk_buff *skb, |
630 | struct flow_dissector_key_control *key_control, |
631 | struct flow_dissector *flow_dissector, |
632 | void *target_container, const void *data, |
633 | __be16 *p_proto, int *p_nhoff, int *p_hlen, |
634 | unsigned int flags) |
635 | { |
636 | struct flow_dissector_key_keyid *key_keyid; |
637 | struct gre_base_hdr *hdr, _hdr; |
638 | int offset = 0; |
639 | u16 gre_ver; |
640 | |
641 | hdr = __skb_header_pointer(skb, offset: *p_nhoff, len: sizeof(_hdr), |
642 | data, hlen: *p_hlen, buffer: &_hdr); |
643 | if (!hdr) |
644 | return FLOW_DISSECT_RET_OUT_BAD; |
645 | |
646 | /* Only look inside GRE without routing */ |
647 | if (hdr->flags & GRE_ROUTING) |
648 | return FLOW_DISSECT_RET_OUT_GOOD; |
649 | |
650 | /* Only look inside GRE for version 0 and 1 */ |
651 | gre_ver = ntohs(hdr->flags & GRE_VERSION); |
652 | if (gre_ver > 1) |
653 | return FLOW_DISSECT_RET_OUT_GOOD; |
654 | |
655 | *p_proto = hdr->protocol; |
656 | if (gre_ver) { |
657 | /* Version1 must be PPTP, and check the flags */ |
658 | if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY))) |
659 | return FLOW_DISSECT_RET_OUT_GOOD; |
660 | } |
661 | |
662 | offset += sizeof(struct gre_base_hdr); |
663 | |
664 | if (hdr->flags & GRE_CSUM) |
665 | offset += sizeof_field(struct gre_full_hdr, csum) + |
666 | sizeof_field(struct gre_full_hdr, reserved1); |
667 | |
668 | if (hdr->flags & GRE_KEY) { |
669 | const __be32 *keyid; |
670 | __be32 _keyid; |
671 | |
672 | keyid = __skb_header_pointer(skb, offset: *p_nhoff + offset, |
673 | len: sizeof(_keyid), |
674 | data, hlen: *p_hlen, buffer: &_keyid); |
675 | if (!keyid) |
676 | return FLOW_DISSECT_RET_OUT_BAD; |
677 | |
678 | if (dissector_uses_key(flow_dissector, |
679 | key_id: FLOW_DISSECTOR_KEY_GRE_KEYID)) { |
680 | key_keyid = skb_flow_dissector_target(flow_dissector, |
681 | key_id: FLOW_DISSECTOR_KEY_GRE_KEYID, |
682 | target_container); |
683 | if (gre_ver == 0) |
684 | key_keyid->keyid = *keyid; |
685 | else |
686 | key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK; |
687 | } |
688 | offset += sizeof_field(struct gre_full_hdr, key); |
689 | } |
690 | |
691 | if (hdr->flags & GRE_SEQ) |
692 | offset += sizeof_field(struct pptp_gre_header, seq); |
693 | |
694 | if (gre_ver == 0) { |
695 | if (*p_proto == htons(ETH_P_TEB)) { |
696 | const struct ethhdr *eth; |
697 | struct ethhdr _eth; |
698 | |
699 | eth = __skb_header_pointer(skb, offset: *p_nhoff + offset, |
700 | len: sizeof(_eth), |
701 | data, hlen: *p_hlen, buffer: &_eth); |
702 | if (!eth) |
703 | return FLOW_DISSECT_RET_OUT_BAD; |
704 | *p_proto = eth->h_proto; |
705 | offset += sizeof(*eth); |
706 | |
707 | /* Cap headers that we access via pointers at the |
708 | * end of the Ethernet header as our maximum alignment |
709 | * at that point is only 2 bytes. |
710 | */ |
711 | if (NET_IP_ALIGN) |
712 | *p_hlen = *p_nhoff + offset; |
713 | } |
714 | } else { /* version 1, must be PPTP */ |
715 | u8 _ppp_hdr[PPP_HDRLEN]; |
716 | u8 *ppp_hdr; |
717 | |
718 | if (hdr->flags & GRE_ACK) |
719 | offset += sizeof_field(struct pptp_gre_header, ack); |
720 | |
721 | ppp_hdr = __skb_header_pointer(skb, offset: *p_nhoff + offset, |
722 | len: sizeof(_ppp_hdr), |
723 | data, hlen: *p_hlen, buffer: _ppp_hdr); |
724 | if (!ppp_hdr) |
725 | return FLOW_DISSECT_RET_OUT_BAD; |
726 | |
727 | switch (PPP_PROTOCOL(ppp_hdr)) { |
728 | case PPP_IP: |
729 | *p_proto = htons(ETH_P_IP); |
730 | break; |
731 | case PPP_IPV6: |
732 | *p_proto = htons(ETH_P_IPV6); |
733 | break; |
734 | default: |
735 | /* Could probably catch some more like MPLS */ |
736 | break; |
737 | } |
738 | |
739 | offset += PPP_HDRLEN; |
740 | } |
741 | |
742 | *p_nhoff += offset; |
743 | key_control->flags |= FLOW_DIS_ENCAPSULATION; |
744 | if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) |
745 | return FLOW_DISSECT_RET_OUT_GOOD; |
746 | |
747 | return FLOW_DISSECT_RET_PROTO_AGAIN; |
748 | } |
749 | |
750 | /** |
751 | * __skb_flow_dissect_batadv() - dissect batman-adv header |
752 | * @skb: sk_buff to with the batman-adv header |
753 | * @key_control: flow dissectors control key |
754 | * @data: raw buffer pointer to the packet, if NULL use skb->data |
755 | * @p_proto: pointer used to update the protocol to process next |
756 | * @p_nhoff: pointer used to update inner network header offset |
757 | * @hlen: packet header length |
758 | * @flags: any combination of FLOW_DISSECTOR_F_* |
759 | * |
760 | * ETH_P_BATMAN packets are tried to be dissected. Only |
761 | * &struct batadv_unicast packets are actually processed because they contain an |
762 | * inner ethernet header and are usually followed by actual network header. This |
763 | * allows the flow dissector to continue processing the packet. |
764 | * |
765 | * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found, |
766 | * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation, |
767 | * otherwise FLOW_DISSECT_RET_OUT_BAD |
768 | */ |
769 | static enum flow_dissect_ret |
770 | __skb_flow_dissect_batadv(const struct sk_buff *skb, |
771 | struct flow_dissector_key_control *key_control, |
772 | const void *data, __be16 *p_proto, int *p_nhoff, |
773 | int hlen, unsigned int flags) |
774 | { |
775 | struct { |
776 | struct batadv_unicast_packet batadv_unicast; |
777 | struct ethhdr eth; |
778 | } *hdr, _hdr; |
779 | |
780 | hdr = __skb_header_pointer(skb, offset: *p_nhoff, len: sizeof(_hdr), data, hlen, |
781 | buffer: &_hdr); |
782 | if (!hdr) |
783 | return FLOW_DISSECT_RET_OUT_BAD; |
784 | |
785 | if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION) |
786 | return FLOW_DISSECT_RET_OUT_BAD; |
787 | |
788 | if (hdr->batadv_unicast.packet_type != BATADV_UNICAST) |
789 | return FLOW_DISSECT_RET_OUT_BAD; |
790 | |
791 | *p_proto = hdr->eth.h_proto; |
792 | *p_nhoff += sizeof(*hdr); |
793 | |
794 | key_control->flags |= FLOW_DIS_ENCAPSULATION; |
795 | if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) |
796 | return FLOW_DISSECT_RET_OUT_GOOD; |
797 | |
798 | return FLOW_DISSECT_RET_PROTO_AGAIN; |
799 | } |
800 | |
801 | static void |
802 | __skb_flow_dissect_tcp(const struct sk_buff *skb, |
803 | struct flow_dissector *flow_dissector, |
804 | void *target_container, const void *data, |
805 | int thoff, int hlen) |
806 | { |
807 | struct flow_dissector_key_tcp *key_tcp; |
808 | struct tcphdr *th, _th; |
809 | |
810 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_TCP)) |
811 | return; |
812 | |
813 | th = __skb_header_pointer(skb, offset: thoff, len: sizeof(_th), data, hlen, buffer: &_th); |
814 | if (!th) |
815 | return; |
816 | |
817 | if (unlikely(__tcp_hdrlen(th) < sizeof(_th))) |
818 | return; |
819 | |
820 | key_tcp = skb_flow_dissector_target(flow_dissector, |
821 | key_id: FLOW_DISSECTOR_KEY_TCP, |
822 | target_container); |
823 | key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF)); |
824 | } |
825 | |
826 | static void |
827 | __skb_flow_dissect_ports(const struct sk_buff *skb, |
828 | struct flow_dissector *flow_dissector, |
829 | void *target_container, const void *data, |
830 | int nhoff, u8 ip_proto, int hlen) |
831 | { |
832 | enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX; |
833 | struct flow_dissector_key_ports *key_ports; |
834 | |
835 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_PORTS)) |
836 | dissector_ports = FLOW_DISSECTOR_KEY_PORTS; |
837 | else if (dissector_uses_key(flow_dissector, |
838 | key_id: FLOW_DISSECTOR_KEY_PORTS_RANGE)) |
839 | dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE; |
840 | |
841 | if (dissector_ports == FLOW_DISSECTOR_KEY_MAX) |
842 | return; |
843 | |
844 | key_ports = skb_flow_dissector_target(flow_dissector, |
845 | key_id: dissector_ports, |
846 | target_container); |
847 | key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto, |
848 | data, hlen); |
849 | } |
850 | |
851 | static void |
852 | __skb_flow_dissect_ipv4(const struct sk_buff *skb, |
853 | struct flow_dissector *flow_dissector, |
854 | void *target_container, const void *data, |
855 | const struct iphdr *iph) |
856 | { |
857 | struct flow_dissector_key_ip *key_ip; |
858 | |
859 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_IP)) |
860 | return; |
861 | |
862 | key_ip = skb_flow_dissector_target(flow_dissector, |
863 | key_id: FLOW_DISSECTOR_KEY_IP, |
864 | target_container); |
865 | key_ip->tos = iph->tos; |
866 | key_ip->ttl = iph->ttl; |
867 | } |
868 | |
869 | static void |
870 | __skb_flow_dissect_ipv6(const struct sk_buff *skb, |
871 | struct flow_dissector *flow_dissector, |
872 | void *target_container, const void *data, |
873 | const struct ipv6hdr *iph) |
874 | { |
875 | struct flow_dissector_key_ip *key_ip; |
876 | |
877 | if (!dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_IP)) |
878 | return; |
879 | |
880 | key_ip = skb_flow_dissector_target(flow_dissector, |
881 | key_id: FLOW_DISSECTOR_KEY_IP, |
882 | target_container); |
883 | key_ip->tos = ipv6_get_dsfield(ipv6h: iph); |
884 | key_ip->ttl = iph->hop_limit; |
885 | } |
886 | |
887 | /* Maximum number of protocol headers that can be parsed in |
888 | * __skb_flow_dissect |
889 | */ |
890 | #define MAX_FLOW_DISSECT_HDRS 15 |
891 | |
892 | static bool skb_flow_dissect_allowed(int *num_hdrs) |
893 | { |
894 | ++*num_hdrs; |
895 | |
896 | return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS); |
897 | } |
898 | |
899 | static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys, |
900 | struct flow_dissector *flow_dissector, |
901 | void *target_container) |
902 | { |
903 | struct flow_dissector_key_ports *key_ports = NULL; |
904 | struct flow_dissector_key_control *key_control; |
905 | struct flow_dissector_key_basic *key_basic; |
906 | struct flow_dissector_key_addrs *key_addrs; |
907 | struct flow_dissector_key_tags *key_tags; |
908 | |
909 | key_control = skb_flow_dissector_target(flow_dissector, |
910 | key_id: FLOW_DISSECTOR_KEY_CONTROL, |
911 | target_container); |
912 | key_control->thoff = flow_keys->thoff; |
913 | if (flow_keys->is_frag) |
914 | key_control->flags |= FLOW_DIS_IS_FRAGMENT; |
915 | if (flow_keys->is_first_frag) |
916 | key_control->flags |= FLOW_DIS_FIRST_FRAG; |
917 | if (flow_keys->is_encap) |
918 | key_control->flags |= FLOW_DIS_ENCAPSULATION; |
919 | |
920 | key_basic = skb_flow_dissector_target(flow_dissector, |
921 | key_id: FLOW_DISSECTOR_KEY_BASIC, |
922 | target_container); |
923 | key_basic->n_proto = flow_keys->n_proto; |
924 | key_basic->ip_proto = flow_keys->ip_proto; |
925 | |
926 | if (flow_keys->addr_proto == ETH_P_IP && |
927 | dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { |
928 | key_addrs = skb_flow_dissector_target(flow_dissector, |
929 | key_id: FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
930 | target_container); |
931 | key_addrs->v4addrs.src = flow_keys->ipv4_src; |
932 | key_addrs->v4addrs.dst = flow_keys->ipv4_dst; |
933 | key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; |
934 | } else if (flow_keys->addr_proto == ETH_P_IPV6 && |
935 | dissector_uses_key(flow_dissector, |
936 | key_id: FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { |
937 | key_addrs = skb_flow_dissector_target(flow_dissector, |
938 | key_id: FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
939 | target_container); |
940 | memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src, |
941 | sizeof(key_addrs->v6addrs.src)); |
942 | memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst, |
943 | sizeof(key_addrs->v6addrs.dst)); |
944 | key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
945 | } |
946 | |
947 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_PORTS)) |
948 | key_ports = skb_flow_dissector_target(flow_dissector, |
949 | key_id: FLOW_DISSECTOR_KEY_PORTS, |
950 | target_container); |
951 | else if (dissector_uses_key(flow_dissector, |
952 | key_id: FLOW_DISSECTOR_KEY_PORTS_RANGE)) |
953 | key_ports = skb_flow_dissector_target(flow_dissector, |
954 | key_id: FLOW_DISSECTOR_KEY_PORTS_RANGE, |
955 | target_container); |
956 | |
957 | if (key_ports) { |
958 | key_ports->src = flow_keys->sport; |
959 | key_ports->dst = flow_keys->dport; |
960 | } |
961 | |
962 | if (dissector_uses_key(flow_dissector, |
963 | key_id: FLOW_DISSECTOR_KEY_FLOW_LABEL)) { |
964 | key_tags = skb_flow_dissector_target(flow_dissector, |
965 | key_id: FLOW_DISSECTOR_KEY_FLOW_LABEL, |
966 | target_container); |
967 | key_tags->flow_label = ntohl(flow_keys->flow_label); |
968 | } |
969 | } |
970 | |
971 | u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx, |
972 | __be16 proto, int nhoff, int hlen, unsigned int flags) |
973 | { |
974 | struct bpf_flow_keys *flow_keys = ctx->flow_keys; |
975 | u32 result; |
976 | |
977 | /* Pass parameters to the BPF program */ |
978 | memset(flow_keys, 0, sizeof(*flow_keys)); |
979 | flow_keys->n_proto = proto; |
980 | flow_keys->nhoff = nhoff; |
981 | flow_keys->thoff = flow_keys->nhoff; |
982 | |
983 | BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG != |
984 | (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG); |
985 | BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL != |
986 | (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); |
987 | BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP != |
988 | (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP); |
989 | flow_keys->flags = flags; |
990 | |
991 | result = bpf_prog_run_pin_on_cpu(prog, ctx); |
992 | |
993 | flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen); |
994 | flow_keys->thoff = clamp_t(u16, flow_keys->thoff, |
995 | flow_keys->nhoff, hlen); |
996 | |
997 | return result; |
998 | } |
999 | |
1000 | static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr) |
1001 | { |
1002 | return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0; |
1003 | } |
1004 | |
1005 | /** |
1006 | * __skb_flow_dissect - extract the flow_keys struct and return it |
1007 | * @net: associated network namespace, derived from @skb if NULL |
1008 | * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified |
1009 | * @flow_dissector: list of keys to dissect |
1010 | * @target_container: target structure to put dissected values into |
1011 | * @data: raw buffer pointer to the packet, if NULL use skb->data |
1012 | * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol |
1013 | * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb) |
1014 | * @hlen: packet header length, if @data is NULL use skb_headlen(skb) |
1015 | * @flags: flags that control the dissection process, e.g. |
1016 | * FLOW_DISSECTOR_F_STOP_AT_ENCAP. |
1017 | * |
1018 | * The function will try to retrieve individual keys into target specified |
1019 | * by flow_dissector from either the skbuff or a raw buffer specified by the |
1020 | * rest parameters. |
1021 | * |
1022 | * Caller must take care of zeroing target container memory. |
1023 | */ |
1024 | bool __skb_flow_dissect(const struct net *net, |
1025 | const struct sk_buff *skb, |
1026 | struct flow_dissector *flow_dissector, |
1027 | void *target_container, const void *data, |
1028 | __be16 proto, int nhoff, int hlen, unsigned int flags) |
1029 | { |
1030 | struct flow_dissector_key_control *key_control; |
1031 | struct flow_dissector_key_basic *key_basic; |
1032 | struct flow_dissector_key_addrs *key_addrs; |
1033 | struct flow_dissector_key_tags *key_tags; |
1034 | struct flow_dissector_key_vlan *key_vlan; |
1035 | enum flow_dissect_ret fdret; |
1036 | enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX; |
1037 | bool mpls_el = false; |
1038 | int mpls_lse = 0; |
1039 | int num_hdrs = 0; |
1040 | u8 ip_proto = 0; |
1041 | bool ret; |
1042 | |
1043 | if (!data) { |
1044 | data = skb->data; |
1045 | proto = skb_vlan_tag_present(skb) ? |
1046 | skb->vlan_proto : skb->protocol; |
1047 | nhoff = skb_network_offset(skb); |
1048 | hlen = skb_headlen(skb); |
1049 | #if IS_ENABLED(CONFIG_NET_DSA) |
1050 | if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) && |
1051 | proto == htons(ETH_P_XDSA))) { |
1052 | struct metadata_dst *md_dst = skb_metadata_dst(skb); |
1053 | const struct dsa_device_ops *ops; |
1054 | int offset = 0; |
1055 | |
1056 | ops = skb->dev->dsa_ptr->tag_ops; |
1057 | /* Only DSA header taggers break flow dissection */ |
1058 | if (ops->needed_headroom && |
1059 | (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) { |
1060 | if (ops->flow_dissect) |
1061 | ops->flow_dissect(skb, &proto, &offset); |
1062 | else |
1063 | dsa_tag_generic_flow_dissect(skb, |
1064 | proto: &proto, |
1065 | offset: &offset); |
1066 | hlen -= offset; |
1067 | nhoff += offset; |
1068 | } |
1069 | } |
1070 | #endif |
1071 | } |
1072 | |
1073 | /* It is ensured by skb_flow_dissector_init() that control key will |
1074 | * be always present. |
1075 | */ |
1076 | key_control = skb_flow_dissector_target(flow_dissector, |
1077 | key_id: FLOW_DISSECTOR_KEY_CONTROL, |
1078 | target_container); |
1079 | |
1080 | /* It is ensured by skb_flow_dissector_init() that basic key will |
1081 | * be always present. |
1082 | */ |
1083 | key_basic = skb_flow_dissector_target(flow_dissector, |
1084 | key_id: FLOW_DISSECTOR_KEY_BASIC, |
1085 | target_container); |
1086 | |
1087 | if (skb) { |
1088 | if (!net) { |
1089 | if (skb->dev) |
1090 | net = dev_net(dev: skb->dev); |
1091 | else if (skb->sk) |
1092 | net = sock_net(sk: skb->sk); |
1093 | } |
1094 | } |
1095 | |
1096 | WARN_ON_ONCE(!net); |
1097 | if (net) { |
1098 | enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR; |
1099 | struct bpf_prog_array *run_array; |
1100 | |
1101 | rcu_read_lock(); |
1102 | run_array = rcu_dereference(init_net.bpf.run_array[type]); |
1103 | if (!run_array) |
1104 | run_array = rcu_dereference(net->bpf.run_array[type]); |
1105 | |
1106 | if (run_array) { |
1107 | struct bpf_flow_keys flow_keys; |
1108 | struct bpf_flow_dissector ctx = { |
1109 | .flow_keys = &flow_keys, |
1110 | .data = data, |
1111 | .data_end = data + hlen, |
1112 | }; |
1113 | __be16 n_proto = proto; |
1114 | struct bpf_prog *prog; |
1115 | u32 result; |
1116 | |
1117 | if (skb) { |
1118 | ctx.skb = skb; |
1119 | /* we can't use 'proto' in the skb case |
1120 | * because it might be set to skb->vlan_proto |
1121 | * which has been pulled from the data |
1122 | */ |
1123 | n_proto = skb->protocol; |
1124 | } |
1125 | |
1126 | prog = READ_ONCE(run_array->items[0].prog); |
1127 | result = bpf_flow_dissect(prog, ctx: &ctx, proto: n_proto, nhoff, |
1128 | hlen, flags); |
1129 | if (result == BPF_FLOW_DISSECTOR_CONTINUE) |
1130 | goto dissect_continue; |
1131 | __skb_flow_bpf_to_target(flow_keys: &flow_keys, flow_dissector, |
1132 | target_container); |
1133 | rcu_read_unlock(); |
1134 | return result == BPF_OK; |
1135 | } |
1136 | dissect_continue: |
1137 | rcu_read_unlock(); |
1138 | } |
1139 | |
1140 | if (dissector_uses_key(flow_dissector, |
1141 | key_id: FLOW_DISSECTOR_KEY_ETH_ADDRS)) { |
1142 | struct ethhdr *eth = eth_hdr(skb); |
1143 | struct flow_dissector_key_eth_addrs *key_eth_addrs; |
1144 | |
1145 | key_eth_addrs = skb_flow_dissector_target(flow_dissector, |
1146 | key_id: FLOW_DISSECTOR_KEY_ETH_ADDRS, |
1147 | target_container); |
1148 | memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs)); |
1149 | } |
1150 | |
1151 | if (dissector_uses_key(flow_dissector, |
1152 | key_id: FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) { |
1153 | struct flow_dissector_key_num_of_vlans *key_num_of_vlans; |
1154 | |
1155 | key_num_of_vlans = skb_flow_dissector_target(flow_dissector, |
1156 | key_id: FLOW_DISSECTOR_KEY_NUM_OF_VLANS, |
1157 | target_container); |
1158 | key_num_of_vlans->num_of_vlans = 0; |
1159 | } |
1160 | |
1161 | proto_again: |
1162 | fdret = FLOW_DISSECT_RET_CONTINUE; |
1163 | |
1164 | switch (proto) { |
1165 | case htons(ETH_P_IP): { |
1166 | const struct iphdr *iph; |
1167 | struct iphdr _iph; |
1168 | |
1169 | iph = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_iph), data, hlen, buffer: &_iph); |
1170 | if (!iph || iph->ihl < 5) { |
1171 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1172 | break; |
1173 | } |
1174 | |
1175 | nhoff += iph->ihl * 4; |
1176 | |
1177 | ip_proto = iph->protocol; |
1178 | |
1179 | if (dissector_uses_key(flow_dissector, |
1180 | key_id: FLOW_DISSECTOR_KEY_IPV4_ADDRS)) { |
1181 | key_addrs = skb_flow_dissector_target(flow_dissector, |
1182 | key_id: FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
1183 | target_container); |
1184 | |
1185 | memcpy(&key_addrs->v4addrs.src, &iph->saddr, |
1186 | sizeof(key_addrs->v4addrs.src)); |
1187 | memcpy(&key_addrs->v4addrs.dst, &iph->daddr, |
1188 | sizeof(key_addrs->v4addrs.dst)); |
1189 | key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; |
1190 | } |
1191 | |
1192 | __skb_flow_dissect_ipv4(skb, flow_dissector, |
1193 | target_container, data, iph); |
1194 | |
1195 | if (ip_is_fragment(iph)) { |
1196 | key_control->flags |= FLOW_DIS_IS_FRAGMENT; |
1197 | |
1198 | if (iph->frag_off & htons(IP_OFFSET)) { |
1199 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1200 | break; |
1201 | } else { |
1202 | key_control->flags |= FLOW_DIS_FIRST_FRAG; |
1203 | if (!(flags & |
1204 | FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) { |
1205 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1206 | break; |
1207 | } |
1208 | } |
1209 | } |
1210 | |
1211 | break; |
1212 | } |
1213 | case htons(ETH_P_IPV6): { |
1214 | const struct ipv6hdr *iph; |
1215 | struct ipv6hdr _iph; |
1216 | |
1217 | iph = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_iph), data, hlen, buffer: &_iph); |
1218 | if (!iph) { |
1219 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1220 | break; |
1221 | } |
1222 | |
1223 | ip_proto = iph->nexthdr; |
1224 | nhoff += sizeof(struct ipv6hdr); |
1225 | |
1226 | if (dissector_uses_key(flow_dissector, |
1227 | key_id: FLOW_DISSECTOR_KEY_IPV6_ADDRS)) { |
1228 | key_addrs = skb_flow_dissector_target(flow_dissector, |
1229 | key_id: FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
1230 | target_container); |
1231 | |
1232 | memcpy(&key_addrs->v6addrs.src, &iph->saddr, |
1233 | sizeof(key_addrs->v6addrs.src)); |
1234 | memcpy(&key_addrs->v6addrs.dst, &iph->daddr, |
1235 | sizeof(key_addrs->v6addrs.dst)); |
1236 | key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
1237 | } |
1238 | |
1239 | if ((dissector_uses_key(flow_dissector, |
1240 | key_id: FLOW_DISSECTOR_KEY_FLOW_LABEL) || |
1241 | (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) && |
1242 | ip6_flowlabel(hdr: iph)) { |
1243 | __be32 flow_label = ip6_flowlabel(hdr: iph); |
1244 | |
1245 | if (dissector_uses_key(flow_dissector, |
1246 | key_id: FLOW_DISSECTOR_KEY_FLOW_LABEL)) { |
1247 | key_tags = skb_flow_dissector_target(flow_dissector, |
1248 | key_id: FLOW_DISSECTOR_KEY_FLOW_LABEL, |
1249 | target_container); |
1250 | key_tags->flow_label = ntohl(flow_label); |
1251 | } |
1252 | if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) { |
1253 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1254 | break; |
1255 | } |
1256 | } |
1257 | |
1258 | __skb_flow_dissect_ipv6(skb, flow_dissector, |
1259 | target_container, data, iph); |
1260 | |
1261 | break; |
1262 | } |
1263 | case htons(ETH_P_8021AD): |
1264 | case htons(ETH_P_8021Q): { |
1265 | const struct vlan_hdr *vlan = NULL; |
1266 | struct vlan_hdr _vlan; |
1267 | __be16 saved_vlan_tpid = proto; |
1268 | |
1269 | if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX && |
1270 | skb && skb_vlan_tag_present(skb)) { |
1271 | proto = skb->protocol; |
1272 | } else { |
1273 | vlan = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_vlan), |
1274 | data, hlen, buffer: &_vlan); |
1275 | if (!vlan) { |
1276 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1277 | break; |
1278 | } |
1279 | |
1280 | proto = vlan->h_vlan_encapsulated_proto; |
1281 | nhoff += sizeof(*vlan); |
1282 | } |
1283 | |
1284 | if (dissector_uses_key(flow_dissector, key_id: FLOW_DISSECTOR_KEY_NUM_OF_VLANS) && |
1285 | !(key_control->flags & FLOW_DIS_ENCAPSULATION)) { |
1286 | struct flow_dissector_key_num_of_vlans *key_nvs; |
1287 | |
1288 | key_nvs = skb_flow_dissector_target(flow_dissector, |
1289 | key_id: FLOW_DISSECTOR_KEY_NUM_OF_VLANS, |
1290 | target_container); |
1291 | key_nvs->num_of_vlans++; |
1292 | } |
1293 | |
1294 | if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) { |
1295 | dissector_vlan = FLOW_DISSECTOR_KEY_VLAN; |
1296 | } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) { |
1297 | dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN; |
1298 | } else { |
1299 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1300 | break; |
1301 | } |
1302 | |
1303 | if (dissector_uses_key(flow_dissector, key_id: dissector_vlan)) { |
1304 | key_vlan = skb_flow_dissector_target(flow_dissector, |
1305 | key_id: dissector_vlan, |
1306 | target_container); |
1307 | |
1308 | if (!vlan) { |
1309 | key_vlan->vlan_id = skb_vlan_tag_get_id(skb); |
1310 | key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb); |
1311 | } else { |
1312 | key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) & |
1313 | VLAN_VID_MASK; |
1314 | key_vlan->vlan_priority = |
1315 | (ntohs(vlan->h_vlan_TCI) & |
1316 | VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT; |
1317 | } |
1318 | key_vlan->vlan_tpid = saved_vlan_tpid; |
1319 | key_vlan->vlan_eth_type = proto; |
1320 | } |
1321 | |
1322 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1323 | break; |
1324 | } |
1325 | case htons(ETH_P_PPP_SES): { |
1326 | struct { |
1327 | struct pppoe_hdr hdr; |
1328 | __be16 proto; |
1329 | } *hdr, _hdr; |
1330 | u16 ppp_proto; |
1331 | |
1332 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, hlen, buffer: &_hdr); |
1333 | if (!hdr) { |
1334 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1335 | break; |
1336 | } |
1337 | |
1338 | if (!is_pppoe_ses_hdr_valid(hdr: &hdr->hdr)) { |
1339 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1340 | break; |
1341 | } |
1342 | |
1343 | /* least significant bit of the most significant octet |
1344 | * indicates if protocol field was compressed |
1345 | */ |
1346 | ppp_proto = ntohs(hdr->proto); |
1347 | if (ppp_proto & 0x0100) { |
1348 | ppp_proto = ppp_proto >> 8; |
1349 | nhoff += PPPOE_SES_HLEN - 1; |
1350 | } else { |
1351 | nhoff += PPPOE_SES_HLEN; |
1352 | } |
1353 | |
1354 | if (ppp_proto == PPP_IP) { |
1355 | proto = htons(ETH_P_IP); |
1356 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1357 | } else if (ppp_proto == PPP_IPV6) { |
1358 | proto = htons(ETH_P_IPV6); |
1359 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1360 | } else if (ppp_proto == PPP_MPLS_UC) { |
1361 | proto = htons(ETH_P_MPLS_UC); |
1362 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1363 | } else if (ppp_proto == PPP_MPLS_MC) { |
1364 | proto = htons(ETH_P_MPLS_MC); |
1365 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1366 | } else if (ppp_proto_is_valid(proto: ppp_proto)) { |
1367 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1368 | } else { |
1369 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1370 | break; |
1371 | } |
1372 | |
1373 | if (dissector_uses_key(flow_dissector, |
1374 | key_id: FLOW_DISSECTOR_KEY_PPPOE)) { |
1375 | struct flow_dissector_key_pppoe *key_pppoe; |
1376 | |
1377 | key_pppoe = skb_flow_dissector_target(flow_dissector, |
1378 | key_id: FLOW_DISSECTOR_KEY_PPPOE, |
1379 | target_container); |
1380 | key_pppoe->session_id = hdr->hdr.sid; |
1381 | key_pppoe->ppp_proto = htons(ppp_proto); |
1382 | key_pppoe->type = htons(ETH_P_PPP_SES); |
1383 | } |
1384 | break; |
1385 | } |
1386 | case htons(ETH_P_TIPC): { |
1387 | struct tipc_basic_hdr *hdr, _hdr; |
1388 | |
1389 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), |
1390 | data, hlen, buffer: &_hdr); |
1391 | if (!hdr) { |
1392 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1393 | break; |
1394 | } |
1395 | |
1396 | if (dissector_uses_key(flow_dissector, |
1397 | key_id: FLOW_DISSECTOR_KEY_TIPC)) { |
1398 | key_addrs = skb_flow_dissector_target(flow_dissector, |
1399 | key_id: FLOW_DISSECTOR_KEY_TIPC, |
1400 | target_container); |
1401 | key_addrs->tipckey.key = tipc_hdr_rps_key(hdr); |
1402 | key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC; |
1403 | } |
1404 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1405 | break; |
1406 | } |
1407 | |
1408 | case htons(ETH_P_MPLS_UC): |
1409 | case htons(ETH_P_MPLS_MC): |
1410 | fdret = __skb_flow_dissect_mpls(skb, flow_dissector, |
1411 | target_container, data, |
1412 | nhoff, hlen, lse_index: mpls_lse, |
1413 | entropy_label: &mpls_el); |
1414 | nhoff += sizeof(struct mpls_label); |
1415 | mpls_lse++; |
1416 | break; |
1417 | case htons(ETH_P_FCOE): |
1418 | if ((hlen - nhoff) < FCOE_HEADER_LEN) { |
1419 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1420 | break; |
1421 | } |
1422 | |
1423 | nhoff += FCOE_HEADER_LEN; |
1424 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1425 | break; |
1426 | |
1427 | case htons(ETH_P_ARP): |
1428 | case htons(ETH_P_RARP): |
1429 | fdret = __skb_flow_dissect_arp(skb, flow_dissector, |
1430 | target_container, data, |
1431 | nhoff, hlen); |
1432 | break; |
1433 | |
1434 | case htons(ETH_P_BATMAN): |
1435 | fdret = __skb_flow_dissect_batadv(skb, key_control, data, |
1436 | p_proto: &proto, p_nhoff: &nhoff, hlen, flags); |
1437 | break; |
1438 | |
1439 | case htons(ETH_P_1588): { |
1440 | struct ptp_header *hdr, _hdr; |
1441 | |
1442 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, |
1443 | hlen, buffer: &_hdr); |
1444 | if (!hdr) { |
1445 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1446 | break; |
1447 | } |
1448 | |
1449 | nhoff += sizeof(struct ptp_header); |
1450 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1451 | break; |
1452 | } |
1453 | |
1454 | case htons(ETH_P_PRP): |
1455 | case htons(ETH_P_HSR): { |
1456 | struct hsr_tag *hdr, _hdr; |
1457 | |
1458 | hdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_hdr), data, hlen, |
1459 | buffer: &_hdr); |
1460 | if (!hdr) { |
1461 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1462 | break; |
1463 | } |
1464 | |
1465 | proto = hdr->encap_proto; |
1466 | nhoff += HSR_HLEN; |
1467 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1468 | break; |
1469 | } |
1470 | |
1471 | case htons(ETH_P_CFM): |
1472 | fdret = __skb_flow_dissect_cfm(skb, flow_dissector, |
1473 | target_container, data, |
1474 | nhoff, hlen); |
1475 | break; |
1476 | |
1477 | default: |
1478 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1479 | break; |
1480 | } |
1481 | |
1482 | /* Process result of proto processing */ |
1483 | switch (fdret) { |
1484 | case FLOW_DISSECT_RET_OUT_GOOD: |
1485 | goto out_good; |
1486 | case FLOW_DISSECT_RET_PROTO_AGAIN: |
1487 | if (skb_flow_dissect_allowed(num_hdrs: &num_hdrs)) |
1488 | goto proto_again; |
1489 | goto out_good; |
1490 | case FLOW_DISSECT_RET_CONTINUE: |
1491 | case FLOW_DISSECT_RET_IPPROTO_AGAIN: |
1492 | break; |
1493 | case FLOW_DISSECT_RET_OUT_BAD: |
1494 | default: |
1495 | goto out_bad; |
1496 | } |
1497 | |
1498 | ip_proto_again: |
1499 | fdret = FLOW_DISSECT_RET_CONTINUE; |
1500 | |
1501 | switch (ip_proto) { |
1502 | case IPPROTO_GRE: |
1503 | if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { |
1504 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1505 | break; |
1506 | } |
1507 | |
1508 | fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector, |
1509 | target_container, data, |
1510 | p_proto: &proto, p_nhoff: &nhoff, p_hlen: &hlen, flags); |
1511 | break; |
1512 | |
1513 | case NEXTHDR_HOP: |
1514 | case NEXTHDR_ROUTING: |
1515 | case NEXTHDR_DEST: { |
1516 | u8 _opthdr[2], *opthdr; |
1517 | |
1518 | if (proto != htons(ETH_P_IPV6)) |
1519 | break; |
1520 | |
1521 | opthdr = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_opthdr), |
1522 | data, hlen, buffer: &_opthdr); |
1523 | if (!opthdr) { |
1524 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1525 | break; |
1526 | } |
1527 | |
1528 | ip_proto = opthdr[0]; |
1529 | nhoff += (opthdr[1] + 1) << 3; |
1530 | |
1531 | fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; |
1532 | break; |
1533 | } |
1534 | case NEXTHDR_FRAGMENT: { |
1535 | struct frag_hdr _fh, *fh; |
1536 | |
1537 | if (proto != htons(ETH_P_IPV6)) |
1538 | break; |
1539 | |
1540 | fh = __skb_header_pointer(skb, offset: nhoff, len: sizeof(_fh), |
1541 | data, hlen, buffer: &_fh); |
1542 | |
1543 | if (!fh) { |
1544 | fdret = FLOW_DISSECT_RET_OUT_BAD; |
1545 | break; |
1546 | } |
1547 | |
1548 | key_control->flags |= FLOW_DIS_IS_FRAGMENT; |
1549 | |
1550 | nhoff += sizeof(_fh); |
1551 | ip_proto = fh->nexthdr; |
1552 | |
1553 | if (!(fh->frag_off & htons(IP6_OFFSET))) { |
1554 | key_control->flags |= FLOW_DIS_FIRST_FRAG; |
1555 | if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) { |
1556 | fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN; |
1557 | break; |
1558 | } |
1559 | } |
1560 | |
1561 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1562 | break; |
1563 | } |
1564 | case IPPROTO_IPIP: |
1565 | if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { |
1566 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1567 | break; |
1568 | } |
1569 | |
1570 | proto = htons(ETH_P_IP); |
1571 | |
1572 | key_control->flags |= FLOW_DIS_ENCAPSULATION; |
1573 | if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { |
1574 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1575 | break; |
1576 | } |
1577 | |
1578 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1579 | break; |
1580 | |
1581 | case IPPROTO_IPV6: |
1582 | if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) { |
1583 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1584 | break; |
1585 | } |
1586 | |
1587 | proto = htons(ETH_P_IPV6); |
1588 | |
1589 | key_control->flags |= FLOW_DIS_ENCAPSULATION; |
1590 | if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) { |
1591 | fdret = FLOW_DISSECT_RET_OUT_GOOD; |
1592 | break; |
1593 | } |
1594 | |
1595 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1596 | break; |
1597 | |
1598 | |
1599 | case IPPROTO_MPLS: |
1600 | proto = htons(ETH_P_MPLS_UC); |
1601 | fdret = FLOW_DISSECT_RET_PROTO_AGAIN; |
1602 | break; |
1603 | |
1604 | case IPPROTO_TCP: |
1605 | __skb_flow_dissect_tcp(skb, flow_dissector, target_container, |
1606 | data, thoff: nhoff, hlen); |
1607 | break; |
1608 | |
1609 | case IPPROTO_ICMP: |
1610 | case IPPROTO_ICMPV6: |
1611 | __skb_flow_dissect_icmp(skb, flow_dissector, target_container, |
1612 | data, thoff: nhoff, hlen); |
1613 | break; |
1614 | case IPPROTO_L2TP: |
1615 | __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container, |
1616 | data, nhoff, hlen); |
1617 | break; |
1618 | case IPPROTO_ESP: |
1619 | __skb_flow_dissect_esp(skb, flow_dissector, target_container, |
1620 | data, nhoff, hlen); |
1621 | break; |
1622 | case IPPROTO_AH: |
1623 | __skb_flow_dissect_ah(skb, flow_dissector, target_container, |
1624 | data, nhoff, hlen); |
1625 | break; |
1626 | default: |
1627 | break; |
1628 | } |
1629 | |
1630 | if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT)) |
1631 | __skb_flow_dissect_ports(skb, flow_dissector, target_container, |
1632 | data, nhoff, ip_proto, hlen); |
1633 | |
1634 | /* Process result of IP proto processing */ |
1635 | switch (fdret) { |
1636 | case FLOW_DISSECT_RET_PROTO_AGAIN: |
1637 | if (skb_flow_dissect_allowed(num_hdrs: &num_hdrs)) |
1638 | goto proto_again; |
1639 | break; |
1640 | case FLOW_DISSECT_RET_IPPROTO_AGAIN: |
1641 | if (skb_flow_dissect_allowed(num_hdrs: &num_hdrs)) |
1642 | goto ip_proto_again; |
1643 | break; |
1644 | case FLOW_DISSECT_RET_OUT_GOOD: |
1645 | case FLOW_DISSECT_RET_CONTINUE: |
1646 | break; |
1647 | case FLOW_DISSECT_RET_OUT_BAD: |
1648 | default: |
1649 | goto out_bad; |
1650 | } |
1651 | |
1652 | out_good: |
1653 | ret = true; |
1654 | |
1655 | out: |
1656 | key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen); |
1657 | key_basic->n_proto = proto; |
1658 | key_basic->ip_proto = ip_proto; |
1659 | |
1660 | return ret; |
1661 | |
1662 | out_bad: |
1663 | ret = false; |
1664 | goto out; |
1665 | } |
1666 | EXPORT_SYMBOL(__skb_flow_dissect); |
1667 | |
1668 | static siphash_aligned_key_t hashrnd; |
1669 | static __always_inline void __flow_hash_secret_init(void) |
1670 | { |
1671 | net_get_random_once(&hashrnd, sizeof(hashrnd)); |
1672 | } |
1673 | |
1674 | static const void *flow_keys_hash_start(const struct flow_keys *flow) |
1675 | { |
1676 | BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT); |
1677 | return &flow->FLOW_KEYS_HASH_START_FIELD; |
1678 | } |
1679 | |
1680 | static inline size_t flow_keys_hash_length(const struct flow_keys *flow) |
1681 | { |
1682 | size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs); |
1683 | |
1684 | BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32)); |
1685 | |
1686 | switch (flow->control.addr_type) { |
1687 | case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
1688 | diff -= sizeof(flow->addrs.v4addrs); |
1689 | break; |
1690 | case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
1691 | diff -= sizeof(flow->addrs.v6addrs); |
1692 | break; |
1693 | case FLOW_DISSECTOR_KEY_TIPC: |
1694 | diff -= sizeof(flow->addrs.tipckey); |
1695 | break; |
1696 | } |
1697 | return sizeof(*flow) - diff; |
1698 | } |
1699 | |
1700 | __be32 flow_get_u32_src(const struct flow_keys *flow) |
1701 | { |
1702 | switch (flow->control.addr_type) { |
1703 | case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
1704 | return flow->addrs.v4addrs.src; |
1705 | case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
1706 | return (__force __be32)ipv6_addr_hash( |
1707 | a: &flow->addrs.v6addrs.src); |
1708 | case FLOW_DISSECTOR_KEY_TIPC: |
1709 | return flow->addrs.tipckey.key; |
1710 | default: |
1711 | return 0; |
1712 | } |
1713 | } |
1714 | EXPORT_SYMBOL(flow_get_u32_src); |
1715 | |
1716 | __be32 flow_get_u32_dst(const struct flow_keys *flow) |
1717 | { |
1718 | switch (flow->control.addr_type) { |
1719 | case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
1720 | return flow->addrs.v4addrs.dst; |
1721 | case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
1722 | return (__force __be32)ipv6_addr_hash( |
1723 | a: &flow->addrs.v6addrs.dst); |
1724 | default: |
1725 | return 0; |
1726 | } |
1727 | } |
1728 | EXPORT_SYMBOL(flow_get_u32_dst); |
1729 | |
1730 | /* Sort the source and destination IP and the ports, |
1731 | * to have consistent hash within the two directions |
1732 | */ |
1733 | static inline void __flow_hash_consistentify(struct flow_keys *keys) |
1734 | { |
1735 | int addr_diff, i; |
1736 | |
1737 | switch (keys->control.addr_type) { |
1738 | case FLOW_DISSECTOR_KEY_IPV4_ADDRS: |
1739 | if ((__force u32)keys->addrs.v4addrs.dst < |
1740 | (__force u32)keys->addrs.v4addrs.src) |
1741 | swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst); |
1742 | |
1743 | if ((__force u16)keys->ports.dst < |
1744 | (__force u16)keys->ports.src) { |
1745 | swap(keys->ports.src, keys->ports.dst); |
1746 | } |
1747 | break; |
1748 | case FLOW_DISSECTOR_KEY_IPV6_ADDRS: |
1749 | addr_diff = memcmp(p: &keys->addrs.v6addrs.dst, |
1750 | q: &keys->addrs.v6addrs.src, |
1751 | size: sizeof(keys->addrs.v6addrs.dst)); |
1752 | if (addr_diff < 0) { |
1753 | for (i = 0; i < 4; i++) |
1754 | swap(keys->addrs.v6addrs.src.s6_addr32[i], |
1755 | keys->addrs.v6addrs.dst.s6_addr32[i]); |
1756 | } |
1757 | if ((__force u16)keys->ports.dst < |
1758 | (__force u16)keys->ports.src) { |
1759 | swap(keys->ports.src, keys->ports.dst); |
1760 | } |
1761 | break; |
1762 | } |
1763 | } |
1764 | |
1765 | static inline u32 __flow_hash_from_keys(struct flow_keys *keys, |
1766 | const siphash_key_t *keyval) |
1767 | { |
1768 | u32 hash; |
1769 | |
1770 | __flow_hash_consistentify(keys); |
1771 | |
1772 | hash = siphash(data: flow_keys_hash_start(flow: keys), |
1773 | len: flow_keys_hash_length(flow: keys), key: keyval); |
1774 | if (!hash) |
1775 | hash = 1; |
1776 | |
1777 | return hash; |
1778 | } |
1779 | |
1780 | u32 flow_hash_from_keys(struct flow_keys *keys) |
1781 | { |
1782 | __flow_hash_secret_init(); |
1783 | return __flow_hash_from_keys(keys, keyval: &hashrnd); |
1784 | } |
1785 | EXPORT_SYMBOL(flow_hash_from_keys); |
1786 | |
1787 | static inline u32 ___skb_get_hash(const struct sk_buff *skb, |
1788 | struct flow_keys *keys, |
1789 | const siphash_key_t *keyval) |
1790 | { |
1791 | skb_flow_dissect_flow_keys(skb, flow: keys, |
1792 | FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL); |
1793 | |
1794 | return __flow_hash_from_keys(keys, keyval); |
1795 | } |
1796 | |
1797 | struct _flow_keys_digest_data { |
1798 | __be16 n_proto; |
1799 | u8 ip_proto; |
1800 | u8 padding; |
1801 | __be32 ports; |
1802 | __be32 src; |
1803 | __be32 dst; |
1804 | }; |
1805 | |
1806 | void make_flow_keys_digest(struct flow_keys_digest *digest, |
1807 | const struct flow_keys *flow) |
1808 | { |
1809 | struct _flow_keys_digest_data *data = |
1810 | (struct _flow_keys_digest_data *)digest; |
1811 | |
1812 | BUILD_BUG_ON(sizeof(*data) > sizeof(*digest)); |
1813 | |
1814 | memset(digest, 0, sizeof(*digest)); |
1815 | |
1816 | data->n_proto = flow->basic.n_proto; |
1817 | data->ip_proto = flow->basic.ip_proto; |
1818 | data->ports = flow->ports.ports; |
1819 | data->src = flow->addrs.v4addrs.src; |
1820 | data->dst = flow->addrs.v4addrs.dst; |
1821 | } |
1822 | EXPORT_SYMBOL(make_flow_keys_digest); |
1823 | |
1824 | static struct flow_dissector flow_keys_dissector_symmetric __read_mostly; |
1825 | |
1826 | u32 __skb_get_hash_symmetric(const struct sk_buff *skb) |
1827 | { |
1828 | struct flow_keys keys; |
1829 | |
1830 | __flow_hash_secret_init(); |
1831 | |
1832 | memset(&keys, 0, sizeof(keys)); |
1833 | __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric, |
1834 | &keys, NULL, 0, 0, 0, 0); |
1835 | |
1836 | return __flow_hash_from_keys(keys: &keys, keyval: &hashrnd); |
1837 | } |
1838 | EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric); |
1839 | |
1840 | /** |
1841 | * __skb_get_hash: calculate a flow hash |
1842 | * @skb: sk_buff to calculate flow hash from |
1843 | * |
1844 | * This function calculates a flow hash based on src/dst addresses |
1845 | * and src/dst port numbers. Sets hash in skb to non-zero hash value |
1846 | * on success, zero indicates no valid hash. Also, sets l4_hash in skb |
1847 | * if hash is a canonical 4-tuple hash over transport ports. |
1848 | */ |
1849 | void __skb_get_hash(struct sk_buff *skb) |
1850 | { |
1851 | struct flow_keys keys; |
1852 | u32 hash; |
1853 | |
1854 | __flow_hash_secret_init(); |
1855 | |
1856 | hash = ___skb_get_hash(skb, keys: &keys, keyval: &hashrnd); |
1857 | |
1858 | __skb_set_sw_hash(skb, hash, is_l4: flow_keys_have_l4(keys: &keys)); |
1859 | } |
1860 | EXPORT_SYMBOL(__skb_get_hash); |
1861 | |
1862 | __u32 skb_get_hash_perturb(const struct sk_buff *skb, |
1863 | const siphash_key_t *perturb) |
1864 | { |
1865 | struct flow_keys keys; |
1866 | |
1867 | return ___skb_get_hash(skb, keys: &keys, keyval: perturb); |
1868 | } |
1869 | EXPORT_SYMBOL(skb_get_hash_perturb); |
1870 | |
1871 | u32 __skb_get_poff(const struct sk_buff *skb, const void *data, |
1872 | const struct flow_keys_basic *keys, int hlen) |
1873 | { |
1874 | u32 poff = keys->control.thoff; |
1875 | |
1876 | /* skip L4 headers for fragments after the first */ |
1877 | if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) && |
1878 | !(keys->control.flags & FLOW_DIS_FIRST_FRAG)) |
1879 | return poff; |
1880 | |
1881 | switch (keys->basic.ip_proto) { |
1882 | case IPPROTO_TCP: { |
1883 | /* access doff as u8 to avoid unaligned access */ |
1884 | const u8 *doff; |
1885 | u8 _doff; |
1886 | |
1887 | doff = __skb_header_pointer(skb, offset: poff + 12, len: sizeof(_doff), |
1888 | data, hlen, buffer: &_doff); |
1889 | if (!doff) |
1890 | return poff; |
1891 | |
1892 | poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2); |
1893 | break; |
1894 | } |
1895 | case IPPROTO_UDP: |
1896 | case IPPROTO_UDPLITE: |
1897 | poff += sizeof(struct udphdr); |
1898 | break; |
1899 | /* For the rest, we do not really care about header |
1900 | * extensions at this point for now. |
1901 | */ |
1902 | case IPPROTO_ICMP: |
1903 | poff += sizeof(struct icmphdr); |
1904 | break; |
1905 | case IPPROTO_ICMPV6: |
1906 | poff += sizeof(struct icmp6hdr); |
1907 | break; |
1908 | case IPPROTO_IGMP: |
1909 | poff += sizeof(struct igmphdr); |
1910 | break; |
1911 | case IPPROTO_DCCP: |
1912 | poff += sizeof(struct dccp_hdr); |
1913 | break; |
1914 | case IPPROTO_SCTP: |
1915 | poff += sizeof(struct sctphdr); |
1916 | break; |
1917 | } |
1918 | |
1919 | return poff; |
1920 | } |
1921 | |
1922 | /** |
1923 | * skb_get_poff - get the offset to the payload |
1924 | * @skb: sk_buff to get the payload offset from |
1925 | * |
1926 | * The function will get the offset to the payload as far as it could |
1927 | * be dissected. The main user is currently BPF, so that we can dynamically |
1928 | * truncate packets without needing to push actual payload to the user |
1929 | * space and can analyze headers only, instead. |
1930 | */ |
1931 | u32 skb_get_poff(const struct sk_buff *skb) |
1932 | { |
1933 | struct flow_keys_basic keys; |
1934 | |
1935 | if (!skb_flow_dissect_flow_keys_basic(NULL, skb, flow: &keys, |
1936 | NULL, proto: 0, nhoff: 0, hlen: 0, flags: 0)) |
1937 | return 0; |
1938 | |
1939 | return __skb_get_poff(skb, data: skb->data, keys: &keys, hlen: skb_headlen(skb)); |
1940 | } |
1941 | |
1942 | __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys) |
1943 | { |
1944 | memset(keys, 0, sizeof(*keys)); |
1945 | |
1946 | memcpy(&keys->addrs.v6addrs.src, &fl6->saddr, |
1947 | sizeof(keys->addrs.v6addrs.src)); |
1948 | memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr, |
1949 | sizeof(keys->addrs.v6addrs.dst)); |
1950 | keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
1951 | keys->ports.src = fl6->fl6_sport; |
1952 | keys->ports.dst = fl6->fl6_dport; |
1953 | keys->keyid.keyid = fl6->fl6_gre_key; |
1954 | keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); |
1955 | keys->basic.ip_proto = fl6->flowi6_proto; |
1956 | |
1957 | return flow_hash_from_keys(keys); |
1958 | } |
1959 | EXPORT_SYMBOL(__get_hash_from_flowi6); |
1960 | |
1961 | static const struct flow_dissector_key flow_keys_dissector_keys[] = { |
1962 | { |
1963 | .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
1964 | .offset = offsetof(struct flow_keys, control), |
1965 | }, |
1966 | { |
1967 | .key_id = FLOW_DISSECTOR_KEY_BASIC, |
1968 | .offset = offsetof(struct flow_keys, basic), |
1969 | }, |
1970 | { |
1971 | .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
1972 | .offset = offsetof(struct flow_keys, addrs.v4addrs), |
1973 | }, |
1974 | { |
1975 | .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
1976 | .offset = offsetof(struct flow_keys, addrs.v6addrs), |
1977 | }, |
1978 | { |
1979 | .key_id = FLOW_DISSECTOR_KEY_TIPC, |
1980 | .offset = offsetof(struct flow_keys, addrs.tipckey), |
1981 | }, |
1982 | { |
1983 | .key_id = FLOW_DISSECTOR_KEY_PORTS, |
1984 | .offset = offsetof(struct flow_keys, ports), |
1985 | }, |
1986 | { |
1987 | .key_id = FLOW_DISSECTOR_KEY_VLAN, |
1988 | .offset = offsetof(struct flow_keys, vlan), |
1989 | }, |
1990 | { |
1991 | .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL, |
1992 | .offset = offsetof(struct flow_keys, tags), |
1993 | }, |
1994 | { |
1995 | .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID, |
1996 | .offset = offsetof(struct flow_keys, keyid), |
1997 | }, |
1998 | }; |
1999 | |
2000 | static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = { |
2001 | { |
2002 | .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
2003 | .offset = offsetof(struct flow_keys, control), |
2004 | }, |
2005 | { |
2006 | .key_id = FLOW_DISSECTOR_KEY_BASIC, |
2007 | .offset = offsetof(struct flow_keys, basic), |
2008 | }, |
2009 | { |
2010 | .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS, |
2011 | .offset = offsetof(struct flow_keys, addrs.v4addrs), |
2012 | }, |
2013 | { |
2014 | .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS, |
2015 | .offset = offsetof(struct flow_keys, addrs.v6addrs), |
2016 | }, |
2017 | { |
2018 | .key_id = FLOW_DISSECTOR_KEY_PORTS, |
2019 | .offset = offsetof(struct flow_keys, ports), |
2020 | }, |
2021 | }; |
2022 | |
2023 | static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = { |
2024 | { |
2025 | .key_id = FLOW_DISSECTOR_KEY_CONTROL, |
2026 | .offset = offsetof(struct flow_keys, control), |
2027 | }, |
2028 | { |
2029 | .key_id = FLOW_DISSECTOR_KEY_BASIC, |
2030 | .offset = offsetof(struct flow_keys, basic), |
2031 | }, |
2032 | }; |
2033 | |
2034 | struct flow_dissector flow_keys_dissector __read_mostly; |
2035 | EXPORT_SYMBOL(flow_keys_dissector); |
2036 | |
2037 | struct flow_dissector flow_keys_basic_dissector __read_mostly; |
2038 | EXPORT_SYMBOL(flow_keys_basic_dissector); |
2039 | |
2040 | static int __init init_default_flow_dissectors(void) |
2041 | { |
2042 | skb_flow_dissector_init(&flow_keys_dissector, |
2043 | flow_keys_dissector_keys, |
2044 | ARRAY_SIZE(flow_keys_dissector_keys)); |
2045 | skb_flow_dissector_init(&flow_keys_dissector_symmetric, |
2046 | flow_keys_dissector_symmetric_keys, |
2047 | ARRAY_SIZE(flow_keys_dissector_symmetric_keys)); |
2048 | skb_flow_dissector_init(&flow_keys_basic_dissector, |
2049 | flow_keys_basic_dissector_keys, |
2050 | ARRAY_SIZE(flow_keys_basic_dissector_keys)); |
2051 | return 0; |
2052 | } |
2053 | core_initcall(init_default_flow_dissectors); |
2054 | |