flow_dissector.c 56 KB

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