1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/skbuff.h>
4 #include <linux/export.h>
6 #include <linux/ipv6.h>
7 #include <linux/if_vlan.h>
9 #include <net/dst_metadata.h>
15 #include <linux/igmp.h>
16 #include <linux/icmp.h>
17 #include <linux/sctp.h>
18 #include <linux/dccp.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/if_pppox.h>
21 #include <linux/ppp_defs.h>
22 #include <linux/stddef.h>
23 #include <linux/if_ether.h>
24 #include <linux/mpls.h>
25 #include <linux/tcp.h>
26 #include <net/flow_dissector.h>
27 #include <scsi/fc/fc_fcoe.h>
28 #include <uapi/linux/batadv_packet.h>
29 #include <linux/bpf.h>
30 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
31 #include <net/netfilter/nf_conntrack_core.h>
32 #include <net/netfilter/nf_conntrack_labels.h>
34 #include <linux/bpf-netns.h>
36 static void dissector_set_key(struct flow_dissector *flow_dissector,
37 enum flow_dissector_key_id key_id)
39 flow_dissector->used_keys |= (1 << key_id);
42 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
43 const struct flow_dissector_key *key,
44 unsigned int key_count)
48 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 withing
52 * boundaries of unsigned short.
54 BUG_ON(key->offset > USHRT_MAX);
55 BUG_ON(dissector_uses_key(flow_dissector,
58 dissector_set_key(flow_dissector, key->key_id);
59 flow_dissector->offset[key->key_id] = key->offset;
62 /* Ensure that the dissector always includes control and basic key.
63 * That way we are able to avoid handling lack of these in fast path.
65 BUG_ON(!dissector_uses_key(flow_dissector,
66 FLOW_DISSECTOR_KEY_CONTROL));
67 BUG_ON(!dissector_uses_key(flow_dissector,
68 FLOW_DISSECTOR_KEY_BASIC));
70 EXPORT_SYMBOL(skb_flow_dissector_init);
72 #ifdef CONFIG_BPF_SYSCALL
73 int flow_dissector_bpf_prog_attach_check(struct net *net,
74 struct bpf_prog *prog)
76 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
78 if (net == &init_net) {
79 /* BPF flow dissector in the root namespace overrides
80 * any per-net-namespace one. When attaching to root,
81 * make sure we don't have any BPF program attached
82 * to the non-root namespaces.
89 if (rcu_access_pointer(ns->bpf.run_array[type]))
93 /* Make sure root flow dissector is not attached
94 * when attaching to the non-root namespace.
96 if (rcu_access_pointer(init_net.bpf.run_array[type]))
102 #endif /* CONFIG_BPF_SYSCALL */
105 * __skb_flow_get_ports - extract the upper layer ports and return them
106 * @skb: sk_buff to extract the ports from
107 * @thoff: transport header offset
108 * @ip_proto: protocol for which to get port offset
109 * @data: raw buffer pointer to the packet, if NULL use skb->data
110 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
112 * The function will try to retrieve the ports at offset thoff + poff where poff
113 * is the protocol port offset returned from proto_ports_offset
115 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
116 void *data, int hlen)
118 int poff = proto_ports_offset(ip_proto);
122 hlen = skb_headlen(skb);
126 __be32 *ports, _ports;
128 ports = __skb_header_pointer(skb, thoff + poff,
129 sizeof(_ports), data, hlen, &_ports);
136 EXPORT_SYMBOL(__skb_flow_get_ports);
138 static bool icmp_has_id(u8 type)
144 case ICMP_TIMESTAMPREPLY:
145 case ICMPV6_ECHO_REQUEST:
146 case ICMPV6_ECHO_REPLY:
154 * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
155 * @skb: sk_buff to extract from
156 * @key_icmp: struct flow_dissector_key_icmp to fill
157 * @data: raw buffer pointer to the packet
158 * @thoff: offset to extract at
159 * @hlen: packet header length
161 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
162 struct flow_dissector_key_icmp *key_icmp,
163 void *data, int thoff, int hlen)
165 struct icmphdr *ih, _ih;
167 ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
171 key_icmp->type = ih->type;
172 key_icmp->code = ih->code;
174 /* As we use 0 to signal that the Id field is not present,
175 * avoid confusion with packets without such field
177 if (icmp_has_id(ih->type))
178 key_icmp->id = ih->un.echo.id ? : 1;
182 EXPORT_SYMBOL(skb_flow_get_icmp_tci);
184 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
185 * using skb_flow_get_icmp_tci().
187 static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
188 struct flow_dissector *flow_dissector,
189 void *target_container,
190 void *data, int thoff, int hlen)
192 struct flow_dissector_key_icmp *key_icmp;
194 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
197 key_icmp = skb_flow_dissector_target(flow_dissector,
198 FLOW_DISSECTOR_KEY_ICMP,
201 skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
204 void skb_flow_dissect_meta(const struct sk_buff *skb,
205 struct flow_dissector *flow_dissector,
206 void *target_container)
208 struct flow_dissector_key_meta *meta;
210 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
213 meta = skb_flow_dissector_target(flow_dissector,
214 FLOW_DISSECTOR_KEY_META,
216 meta->ingress_ifindex = skb->skb_iif;
218 EXPORT_SYMBOL(skb_flow_dissect_meta);
221 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
222 struct flow_dissector *flow_dissector,
223 void *target_container)
225 struct flow_dissector_key_control *ctrl;
227 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
230 ctrl = skb_flow_dissector_target(flow_dissector,
231 FLOW_DISSECTOR_KEY_ENC_CONTROL,
233 ctrl->addr_type = type;
237 skb_flow_dissect_ct(const struct sk_buff *skb,
238 struct flow_dissector *flow_dissector,
239 void *target_container,
243 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
244 struct flow_dissector_key_ct *key;
245 enum ip_conntrack_info ctinfo;
246 struct nf_conn_labels *cl;
249 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
252 ct = nf_ct_get(skb, &ctinfo);
256 key = skb_flow_dissector_target(flow_dissector,
257 FLOW_DISSECTOR_KEY_CT,
260 if (ctinfo < mapsize)
261 key->ct_state = ctinfo_map[ctinfo];
262 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
263 key->ct_zone = ct->zone.id;
265 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
266 key->ct_mark = ct->mark;
269 cl = nf_ct_labels_find(ct);
271 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
272 #endif /* CONFIG_NF_CONNTRACK */
274 EXPORT_SYMBOL(skb_flow_dissect_ct);
277 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
278 struct flow_dissector *flow_dissector,
279 void *target_container)
281 struct ip_tunnel_info *info;
282 struct ip_tunnel_key *key;
284 /* A quick check to see if there might be something to do. */
285 if (!dissector_uses_key(flow_dissector,
286 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
287 !dissector_uses_key(flow_dissector,
288 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
289 !dissector_uses_key(flow_dissector,
290 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
291 !dissector_uses_key(flow_dissector,
292 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
293 !dissector_uses_key(flow_dissector,
294 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
295 !dissector_uses_key(flow_dissector,
296 FLOW_DISSECTOR_KEY_ENC_IP) &&
297 !dissector_uses_key(flow_dissector,
298 FLOW_DISSECTOR_KEY_ENC_OPTS))
301 info = skb_tunnel_info(skb);
307 switch (ip_tunnel_info_af(info)) {
309 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
312 if (dissector_uses_key(flow_dissector,
313 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
314 struct flow_dissector_key_ipv4_addrs *ipv4;
316 ipv4 = skb_flow_dissector_target(flow_dissector,
317 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
319 ipv4->src = key->u.ipv4.src;
320 ipv4->dst = key->u.ipv4.dst;
324 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
327 if (dissector_uses_key(flow_dissector,
328 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
329 struct flow_dissector_key_ipv6_addrs *ipv6;
331 ipv6 = skb_flow_dissector_target(flow_dissector,
332 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
334 ipv6->src = key->u.ipv6.src;
335 ipv6->dst = key->u.ipv6.dst;
340 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
341 struct flow_dissector_key_keyid *keyid;
343 keyid = skb_flow_dissector_target(flow_dissector,
344 FLOW_DISSECTOR_KEY_ENC_KEYID,
346 keyid->keyid = tunnel_id_to_key32(key->tun_id);
349 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
350 struct flow_dissector_key_ports *tp;
352 tp = skb_flow_dissector_target(flow_dissector,
353 FLOW_DISSECTOR_KEY_ENC_PORTS,
355 tp->src = key->tp_src;
356 tp->dst = key->tp_dst;
359 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
360 struct flow_dissector_key_ip *ip;
362 ip = skb_flow_dissector_target(flow_dissector,
363 FLOW_DISSECTOR_KEY_ENC_IP,
369 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
370 struct flow_dissector_key_enc_opts *enc_opt;
372 enc_opt = skb_flow_dissector_target(flow_dissector,
373 FLOW_DISSECTOR_KEY_ENC_OPTS,
376 if (info->options_len) {
377 enc_opt->len = info->options_len;
378 ip_tunnel_info_opts_get(enc_opt->data, info);
379 enc_opt->dst_opt_type = info->key.tun_flags &
380 TUNNEL_OPTIONS_PRESENT;
384 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
386 void skb_flow_dissect_hash(const struct sk_buff *skb,
387 struct flow_dissector *flow_dissector,
388 void *target_container)
390 struct flow_dissector_key_hash *key;
392 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
395 key = skb_flow_dissector_target(flow_dissector,
396 FLOW_DISSECTOR_KEY_HASH,
399 key->hash = skb_get_hash_raw(skb);
401 EXPORT_SYMBOL(skb_flow_dissect_hash);
403 static enum flow_dissect_ret
404 __skb_flow_dissect_mpls(const struct sk_buff *skb,
405 struct flow_dissector *flow_dissector,
406 void *target_container, void *data, int nhoff, int hlen,
407 int lse_index, bool *entropy_label)
409 struct mpls_label *hdr, _hdr;
410 u32 entry, label, bos;
412 if (!dissector_uses_key(flow_dissector,
413 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
414 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
415 return FLOW_DISSECT_RET_OUT_GOOD;
417 if (lse_index >= FLOW_DIS_MPLS_MAX)
418 return FLOW_DISSECT_RET_OUT_GOOD;
420 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
423 return FLOW_DISSECT_RET_OUT_BAD;
425 entry = ntohl(hdr->entry);
426 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
427 bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
429 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
430 struct flow_dissector_key_mpls *key_mpls;
431 struct flow_dissector_mpls_lse *lse;
433 key_mpls = skb_flow_dissector_target(flow_dissector,
434 FLOW_DISSECTOR_KEY_MPLS,
436 lse = &key_mpls->ls[lse_index];
438 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
440 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
441 lse->mpls_label = label;
442 dissector_set_mpls_lse(key_mpls, lse_index);
445 if (*entropy_label &&
446 dissector_uses_key(flow_dissector,
447 FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
448 struct flow_dissector_key_keyid *key_keyid;
450 key_keyid = skb_flow_dissector_target(flow_dissector,
451 FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
453 key_keyid->keyid = cpu_to_be32(label);
456 *entropy_label = label == MPLS_LABEL_ENTROPY;
458 return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
461 static enum flow_dissect_ret
462 __skb_flow_dissect_arp(const struct sk_buff *skb,
463 struct flow_dissector *flow_dissector,
464 void *target_container, void *data, int nhoff, int hlen)
466 struct flow_dissector_key_arp *key_arp;
468 unsigned char ar_sha[ETH_ALEN];
469 unsigned char ar_sip[4];
470 unsigned char ar_tha[ETH_ALEN];
471 unsigned char ar_tip[4];
472 } *arp_eth, _arp_eth;
473 const struct arphdr *arp;
476 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
477 return FLOW_DISSECT_RET_OUT_GOOD;
479 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
482 return FLOW_DISSECT_RET_OUT_BAD;
484 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
485 arp->ar_pro != htons(ETH_P_IP) ||
486 arp->ar_hln != ETH_ALEN ||
488 (arp->ar_op != htons(ARPOP_REPLY) &&
489 arp->ar_op != htons(ARPOP_REQUEST)))
490 return FLOW_DISSECT_RET_OUT_BAD;
492 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
493 sizeof(_arp_eth), data,
496 return FLOW_DISSECT_RET_OUT_BAD;
498 key_arp = skb_flow_dissector_target(flow_dissector,
499 FLOW_DISSECTOR_KEY_ARP,
502 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
503 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
505 /* Only store the lower byte of the opcode;
506 * this covers ARPOP_REPLY and ARPOP_REQUEST.
508 key_arp->op = ntohs(arp->ar_op) & 0xff;
510 ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
511 ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
513 return FLOW_DISSECT_RET_OUT_GOOD;
516 static enum flow_dissect_ret
517 __skb_flow_dissect_gre(const struct sk_buff *skb,
518 struct flow_dissector_key_control *key_control,
519 struct flow_dissector *flow_dissector,
520 void *target_container, void *data,
521 __be16 *p_proto, int *p_nhoff, int *p_hlen,
524 struct flow_dissector_key_keyid *key_keyid;
525 struct gre_base_hdr *hdr, _hdr;
529 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
530 data, *p_hlen, &_hdr);
532 return FLOW_DISSECT_RET_OUT_BAD;
534 /* Only look inside GRE without routing */
535 if (hdr->flags & GRE_ROUTING)
536 return FLOW_DISSECT_RET_OUT_GOOD;
538 /* Only look inside GRE for version 0 and 1 */
539 gre_ver = ntohs(hdr->flags & GRE_VERSION);
541 return FLOW_DISSECT_RET_OUT_GOOD;
543 *p_proto = hdr->protocol;
545 /* Version1 must be PPTP, and check the flags */
546 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
547 return FLOW_DISSECT_RET_OUT_GOOD;
550 offset += sizeof(struct gre_base_hdr);
552 if (hdr->flags & GRE_CSUM)
553 offset += sizeof_field(struct gre_full_hdr, csum) +
554 sizeof_field(struct gre_full_hdr, reserved1);
556 if (hdr->flags & GRE_KEY) {
560 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
562 data, *p_hlen, &_keyid);
564 return FLOW_DISSECT_RET_OUT_BAD;
566 if (dissector_uses_key(flow_dissector,
567 FLOW_DISSECTOR_KEY_GRE_KEYID)) {
568 key_keyid = skb_flow_dissector_target(flow_dissector,
569 FLOW_DISSECTOR_KEY_GRE_KEYID,
572 key_keyid->keyid = *keyid;
574 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
576 offset += sizeof_field(struct gre_full_hdr, key);
579 if (hdr->flags & GRE_SEQ)
580 offset += sizeof_field(struct pptp_gre_header, seq);
583 if (*p_proto == htons(ETH_P_TEB)) {
584 const struct ethhdr *eth;
587 eth = __skb_header_pointer(skb, *p_nhoff + offset,
589 data, *p_hlen, &_eth);
591 return FLOW_DISSECT_RET_OUT_BAD;
592 *p_proto = eth->h_proto;
593 offset += sizeof(*eth);
595 /* Cap headers that we access via pointers at the
596 * end of the Ethernet header as our maximum alignment
597 * at that point is only 2 bytes.
600 *p_hlen = *p_nhoff + offset;
602 } else { /* version 1, must be PPTP */
603 u8 _ppp_hdr[PPP_HDRLEN];
606 if (hdr->flags & GRE_ACK)
607 offset += sizeof_field(struct pptp_gre_header, ack);
609 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
611 data, *p_hlen, _ppp_hdr);
613 return FLOW_DISSECT_RET_OUT_BAD;
615 switch (PPP_PROTOCOL(ppp_hdr)) {
617 *p_proto = htons(ETH_P_IP);
620 *p_proto = htons(ETH_P_IPV6);
623 /* Could probably catch some more like MPLS */
627 offset += PPP_HDRLEN;
631 key_control->flags |= FLOW_DIS_ENCAPSULATION;
632 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
633 return FLOW_DISSECT_RET_OUT_GOOD;
635 return FLOW_DISSECT_RET_PROTO_AGAIN;
639 * __skb_flow_dissect_batadv() - dissect batman-adv header
640 * @skb: sk_buff to with the batman-adv header
641 * @key_control: flow dissectors control key
642 * @data: raw buffer pointer to the packet, if NULL use skb->data
643 * @p_proto: pointer used to update the protocol to process next
644 * @p_nhoff: pointer used to update inner network header offset
645 * @hlen: packet header length
646 * @flags: any combination of FLOW_DISSECTOR_F_*
648 * ETH_P_BATMAN packets are tried to be dissected. Only
649 * &struct batadv_unicast packets are actually processed because they contain an
650 * inner ethernet header and are usually followed by actual network header. This
651 * allows the flow dissector to continue processing the packet.
653 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
654 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
655 * otherwise FLOW_DISSECT_RET_OUT_BAD
657 static enum flow_dissect_ret
658 __skb_flow_dissect_batadv(const struct sk_buff *skb,
659 struct flow_dissector_key_control *key_control,
660 void *data, __be16 *p_proto, int *p_nhoff, int hlen,
664 struct batadv_unicast_packet batadv_unicast;
668 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
671 return FLOW_DISSECT_RET_OUT_BAD;
673 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
674 return FLOW_DISSECT_RET_OUT_BAD;
676 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
677 return FLOW_DISSECT_RET_OUT_BAD;
679 *p_proto = hdr->eth.h_proto;
680 *p_nhoff += sizeof(*hdr);
682 key_control->flags |= FLOW_DIS_ENCAPSULATION;
683 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
684 return FLOW_DISSECT_RET_OUT_GOOD;
686 return FLOW_DISSECT_RET_PROTO_AGAIN;
690 __skb_flow_dissect_tcp(const struct sk_buff *skb,
691 struct flow_dissector *flow_dissector,
692 void *target_container, void *data, int thoff, int hlen)
694 struct flow_dissector_key_tcp *key_tcp;
695 struct tcphdr *th, _th;
697 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
700 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
704 if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
707 key_tcp = skb_flow_dissector_target(flow_dissector,
708 FLOW_DISSECTOR_KEY_TCP,
710 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
714 __skb_flow_dissect_ports(const struct sk_buff *skb,
715 struct flow_dissector *flow_dissector,
716 void *target_container, void *data, int nhoff,
717 u8 ip_proto, int hlen)
719 enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX;
720 struct flow_dissector_key_ports *key_ports;
722 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
723 dissector_ports = FLOW_DISSECTOR_KEY_PORTS;
724 else if (dissector_uses_key(flow_dissector,
725 FLOW_DISSECTOR_KEY_PORTS_RANGE))
726 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
728 if (dissector_ports == FLOW_DISSECTOR_KEY_MAX)
731 key_ports = skb_flow_dissector_target(flow_dissector,
734 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
739 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
740 struct flow_dissector *flow_dissector,
741 void *target_container, void *data, const struct iphdr *iph)
743 struct flow_dissector_key_ip *key_ip;
745 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
748 key_ip = skb_flow_dissector_target(flow_dissector,
749 FLOW_DISSECTOR_KEY_IP,
751 key_ip->tos = iph->tos;
752 key_ip->ttl = iph->ttl;
756 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
757 struct flow_dissector *flow_dissector,
758 void *target_container, void *data, const struct ipv6hdr *iph)
760 struct flow_dissector_key_ip *key_ip;
762 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
765 key_ip = skb_flow_dissector_target(flow_dissector,
766 FLOW_DISSECTOR_KEY_IP,
768 key_ip->tos = ipv6_get_dsfield(iph);
769 key_ip->ttl = iph->hop_limit;
772 /* Maximum number of protocol headers that can be parsed in
775 #define MAX_FLOW_DISSECT_HDRS 15
777 static bool skb_flow_dissect_allowed(int *num_hdrs)
781 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
784 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
785 struct flow_dissector *flow_dissector,
786 void *target_container)
788 struct flow_dissector_key_ports *key_ports = NULL;
789 struct flow_dissector_key_control *key_control;
790 struct flow_dissector_key_basic *key_basic;
791 struct flow_dissector_key_addrs *key_addrs;
792 struct flow_dissector_key_tags *key_tags;
794 key_control = skb_flow_dissector_target(flow_dissector,
795 FLOW_DISSECTOR_KEY_CONTROL,
797 key_control->thoff = flow_keys->thoff;
798 if (flow_keys->is_frag)
799 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
800 if (flow_keys->is_first_frag)
801 key_control->flags |= FLOW_DIS_FIRST_FRAG;
802 if (flow_keys->is_encap)
803 key_control->flags |= FLOW_DIS_ENCAPSULATION;
805 key_basic = skb_flow_dissector_target(flow_dissector,
806 FLOW_DISSECTOR_KEY_BASIC,
808 key_basic->n_proto = flow_keys->n_proto;
809 key_basic->ip_proto = flow_keys->ip_proto;
811 if (flow_keys->addr_proto == ETH_P_IP &&
812 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
813 key_addrs = skb_flow_dissector_target(flow_dissector,
814 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
816 key_addrs->v4addrs.src = flow_keys->ipv4_src;
817 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
818 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
819 } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
820 dissector_uses_key(flow_dissector,
821 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
822 key_addrs = skb_flow_dissector_target(flow_dissector,
823 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
825 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
826 sizeof(key_addrs->v6addrs));
827 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
830 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
831 key_ports = skb_flow_dissector_target(flow_dissector,
832 FLOW_DISSECTOR_KEY_PORTS,
834 else if (dissector_uses_key(flow_dissector,
835 FLOW_DISSECTOR_KEY_PORTS_RANGE))
836 key_ports = skb_flow_dissector_target(flow_dissector,
837 FLOW_DISSECTOR_KEY_PORTS_RANGE,
841 key_ports->src = flow_keys->sport;
842 key_ports->dst = flow_keys->dport;
845 if (dissector_uses_key(flow_dissector,
846 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
847 key_tags = skb_flow_dissector_target(flow_dissector,
848 FLOW_DISSECTOR_KEY_FLOW_LABEL,
850 key_tags->flow_label = ntohl(flow_keys->flow_label);
854 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
855 __be16 proto, int nhoff, int hlen, unsigned int flags)
857 struct bpf_flow_keys *flow_keys = ctx->flow_keys;
860 /* Pass parameters to the BPF program */
861 memset(flow_keys, 0, sizeof(*flow_keys));
862 flow_keys->n_proto = proto;
863 flow_keys->nhoff = nhoff;
864 flow_keys->thoff = flow_keys->nhoff;
866 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
867 (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
868 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
869 (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
870 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
871 (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
872 flow_keys->flags = flags;
874 result = bpf_prog_run_pin_on_cpu(prog, ctx);
876 flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
877 flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
878 flow_keys->nhoff, hlen);
880 return result == BPF_OK;
884 * __skb_flow_dissect - extract the flow_keys struct and return it
885 * @net: associated network namespace, derived from @skb if NULL
886 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
887 * @flow_dissector: list of keys to dissect
888 * @target_container: target structure to put dissected values into
889 * @data: raw buffer pointer to the packet, if NULL use skb->data
890 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
891 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
892 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
893 * @flags: flags that control the dissection process, e.g.
894 * FLOW_DISSECTOR_F_STOP_AT_ENCAP.
896 * The function will try to retrieve individual keys into target specified
897 * by flow_dissector from either the skbuff or a raw buffer specified by the
900 * Caller must take care of zeroing target container memory.
902 bool __skb_flow_dissect(const struct net *net,
903 const struct sk_buff *skb,
904 struct flow_dissector *flow_dissector,
905 void *target_container,
906 void *data, __be16 proto, int nhoff, int hlen,
909 struct flow_dissector_key_control *key_control;
910 struct flow_dissector_key_basic *key_basic;
911 struct flow_dissector_key_addrs *key_addrs;
912 struct flow_dissector_key_tags *key_tags;
913 struct flow_dissector_key_vlan *key_vlan;
914 enum flow_dissect_ret fdret;
915 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
916 bool mpls_el = false;
924 proto = skb_vlan_tag_present(skb) ?
925 skb->vlan_proto : skb->protocol;
926 nhoff = skb_network_offset(skb);
927 hlen = skb_headlen(skb);
928 #if IS_ENABLED(CONFIG_NET_DSA)
929 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
930 proto == htons(ETH_P_XDSA))) {
931 const struct dsa_device_ops *ops;
934 ops = skb->dev->dsa_ptr->tag_ops;
935 if (ops->flow_dissect &&
936 !ops->flow_dissect(skb, &proto, &offset)) {
944 /* It is ensured by skb_flow_dissector_init() that control key will
947 key_control = skb_flow_dissector_target(flow_dissector,
948 FLOW_DISSECTOR_KEY_CONTROL,
951 /* It is ensured by skb_flow_dissector_init() that basic key will
954 key_basic = skb_flow_dissector_target(flow_dissector,
955 FLOW_DISSECTOR_KEY_BASIC,
961 net = dev_net(skb->dev);
963 net = sock_net(skb->sk);
969 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
970 struct bpf_prog_array *run_array;
973 run_array = rcu_dereference(init_net.bpf.run_array[type]);
975 run_array = rcu_dereference(net->bpf.run_array[type]);
978 struct bpf_flow_keys flow_keys;
979 struct bpf_flow_dissector ctx = {
980 .flow_keys = &flow_keys,
982 .data_end = data + hlen,
984 __be16 n_proto = proto;
985 struct bpf_prog *prog;
989 /* we can't use 'proto' in the skb case
990 * because it might be set to skb->vlan_proto
991 * which has been pulled from the data
993 n_proto = skb->protocol;
996 prog = READ_ONCE(run_array->items[0].prog);
997 ret = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
999 __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1007 if (dissector_uses_key(flow_dissector,
1008 FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1009 struct ethhdr *eth = eth_hdr(skb);
1010 struct flow_dissector_key_eth_addrs *key_eth_addrs;
1012 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1013 FLOW_DISSECTOR_KEY_ETH_ADDRS,
1015 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
1019 fdret = FLOW_DISSECT_RET_CONTINUE;
1022 case htons(ETH_P_IP): {
1023 const struct iphdr *iph;
1026 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1027 if (!iph || iph->ihl < 5) {
1028 fdret = FLOW_DISSECT_RET_OUT_BAD;
1032 nhoff += iph->ihl * 4;
1034 ip_proto = iph->protocol;
1036 if (dissector_uses_key(flow_dissector,
1037 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1038 key_addrs = skb_flow_dissector_target(flow_dissector,
1039 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1042 memcpy(&key_addrs->v4addrs, &iph->saddr,
1043 sizeof(key_addrs->v4addrs));
1044 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1047 if (ip_is_fragment(iph)) {
1048 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1050 if (iph->frag_off & htons(IP_OFFSET)) {
1051 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1054 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1056 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1057 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1063 __skb_flow_dissect_ipv4(skb, flow_dissector,
1064 target_container, data, iph);
1068 case htons(ETH_P_IPV6): {
1069 const struct ipv6hdr *iph;
1070 struct ipv6hdr _iph;
1072 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1074 fdret = FLOW_DISSECT_RET_OUT_BAD;
1078 ip_proto = iph->nexthdr;
1079 nhoff += sizeof(struct ipv6hdr);
1081 if (dissector_uses_key(flow_dissector,
1082 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1083 key_addrs = skb_flow_dissector_target(flow_dissector,
1084 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1087 memcpy(&key_addrs->v6addrs, &iph->saddr,
1088 sizeof(key_addrs->v6addrs));
1089 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1092 if ((dissector_uses_key(flow_dissector,
1093 FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1094 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1095 ip6_flowlabel(iph)) {
1096 __be32 flow_label = ip6_flowlabel(iph);
1098 if (dissector_uses_key(flow_dissector,
1099 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1100 key_tags = skb_flow_dissector_target(flow_dissector,
1101 FLOW_DISSECTOR_KEY_FLOW_LABEL,
1103 key_tags->flow_label = ntohl(flow_label);
1105 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1106 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1111 __skb_flow_dissect_ipv6(skb, flow_dissector,
1112 target_container, data, iph);
1116 case htons(ETH_P_8021AD):
1117 case htons(ETH_P_8021Q): {
1118 const struct vlan_hdr *vlan = NULL;
1119 struct vlan_hdr _vlan;
1120 __be16 saved_vlan_tpid = proto;
1122 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1123 skb && skb_vlan_tag_present(skb)) {
1124 proto = skb->protocol;
1126 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1127 data, hlen, &_vlan);
1129 fdret = FLOW_DISSECT_RET_OUT_BAD;
1133 proto = vlan->h_vlan_encapsulated_proto;
1134 nhoff += sizeof(*vlan);
1137 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1138 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1139 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1140 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1142 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1146 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1147 key_vlan = skb_flow_dissector_target(flow_dissector,
1152 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1153 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1155 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1157 key_vlan->vlan_priority =
1158 (ntohs(vlan->h_vlan_TCI) &
1159 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1161 key_vlan->vlan_tpid = saved_vlan_tpid;
1164 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1167 case htons(ETH_P_PPP_SES): {
1169 struct pppoe_hdr hdr;
1172 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1174 fdret = FLOW_DISSECT_RET_OUT_BAD;
1179 nhoff += PPPOE_SES_HLEN;
1182 proto = htons(ETH_P_IP);
1183 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1185 case htons(PPP_IPV6):
1186 proto = htons(ETH_P_IPV6);
1187 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1190 fdret = FLOW_DISSECT_RET_OUT_BAD;
1195 case htons(ETH_P_TIPC): {
1196 struct tipc_basic_hdr *hdr, _hdr;
1198 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1201 fdret = FLOW_DISSECT_RET_OUT_BAD;
1205 if (dissector_uses_key(flow_dissector,
1206 FLOW_DISSECTOR_KEY_TIPC)) {
1207 key_addrs = skb_flow_dissector_target(flow_dissector,
1208 FLOW_DISSECTOR_KEY_TIPC,
1210 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1211 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1213 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1217 case htons(ETH_P_MPLS_UC):
1218 case htons(ETH_P_MPLS_MC):
1219 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1220 target_container, data,
1221 nhoff, hlen, mpls_lse,
1223 nhoff += sizeof(struct mpls_label);
1226 case htons(ETH_P_FCOE):
1227 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1228 fdret = FLOW_DISSECT_RET_OUT_BAD;
1232 nhoff += FCOE_HEADER_LEN;
1233 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1236 case htons(ETH_P_ARP):
1237 case htons(ETH_P_RARP):
1238 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1239 target_container, data,
1243 case htons(ETH_P_BATMAN):
1244 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1245 &proto, &nhoff, hlen, flags);
1249 fdret = FLOW_DISSECT_RET_OUT_BAD;
1253 /* Process result of proto processing */
1255 case FLOW_DISSECT_RET_OUT_GOOD:
1257 case FLOW_DISSECT_RET_PROTO_AGAIN:
1258 if (skb_flow_dissect_allowed(&num_hdrs))
1261 case FLOW_DISSECT_RET_CONTINUE:
1262 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1264 case FLOW_DISSECT_RET_OUT_BAD:
1270 fdret = FLOW_DISSECT_RET_CONTINUE;
1274 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1275 target_container, data,
1276 &proto, &nhoff, &hlen, flags);
1280 case NEXTHDR_ROUTING:
1281 case NEXTHDR_DEST: {
1282 u8 _opthdr[2], *opthdr;
1284 if (proto != htons(ETH_P_IPV6))
1287 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1288 data, hlen, &_opthdr);
1290 fdret = FLOW_DISSECT_RET_OUT_BAD;
1294 ip_proto = opthdr[0];
1295 nhoff += (opthdr[1] + 1) << 3;
1297 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1300 case NEXTHDR_FRAGMENT: {
1301 struct frag_hdr _fh, *fh;
1303 if (proto != htons(ETH_P_IPV6))
1306 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1310 fdret = FLOW_DISSECT_RET_OUT_BAD;
1314 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1316 nhoff += sizeof(_fh);
1317 ip_proto = fh->nexthdr;
1319 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1320 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1321 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1322 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1327 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1331 proto = htons(ETH_P_IP);
1333 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1334 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1335 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1339 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1343 proto = htons(ETH_P_IPV6);
1345 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1346 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1347 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1351 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1356 proto = htons(ETH_P_MPLS_UC);
1357 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1361 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1366 case IPPROTO_ICMPV6:
1367 __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1375 if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1376 __skb_flow_dissect_ports(skb, flow_dissector, target_container,
1377 data, nhoff, ip_proto, hlen);
1379 /* Process result of IP proto processing */
1381 case FLOW_DISSECT_RET_PROTO_AGAIN:
1382 if (skb_flow_dissect_allowed(&num_hdrs))
1385 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1386 if (skb_flow_dissect_allowed(&num_hdrs))
1387 goto ip_proto_again;
1389 case FLOW_DISSECT_RET_OUT_GOOD:
1390 case FLOW_DISSECT_RET_CONTINUE:
1392 case FLOW_DISSECT_RET_OUT_BAD:
1401 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1402 key_basic->n_proto = proto;
1403 key_basic->ip_proto = ip_proto;
1411 EXPORT_SYMBOL(__skb_flow_dissect);
1413 static siphash_key_t hashrnd __read_mostly;
1414 static __always_inline void __flow_hash_secret_init(void)
1416 net_get_random_once(&hashrnd, sizeof(hashrnd));
1419 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1421 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1422 return &flow->FLOW_KEYS_HASH_START_FIELD;
1425 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1427 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1429 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1431 switch (flow->control.addr_type) {
1432 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1433 diff -= sizeof(flow->addrs.v4addrs);
1435 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1436 diff -= sizeof(flow->addrs.v6addrs);
1438 case FLOW_DISSECTOR_KEY_TIPC:
1439 diff -= sizeof(flow->addrs.tipckey);
1442 return sizeof(*flow) - diff;
1445 __be32 flow_get_u32_src(const struct flow_keys *flow)
1447 switch (flow->control.addr_type) {
1448 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1449 return flow->addrs.v4addrs.src;
1450 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1451 return (__force __be32)ipv6_addr_hash(
1452 &flow->addrs.v6addrs.src);
1453 case FLOW_DISSECTOR_KEY_TIPC:
1454 return flow->addrs.tipckey.key;
1459 EXPORT_SYMBOL(flow_get_u32_src);
1461 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1463 switch (flow->control.addr_type) {
1464 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1465 return flow->addrs.v4addrs.dst;
1466 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1467 return (__force __be32)ipv6_addr_hash(
1468 &flow->addrs.v6addrs.dst);
1473 EXPORT_SYMBOL(flow_get_u32_dst);
1475 /* Sort the source and destination IP (and the ports if the IP are the same),
1476 * to have consistent hash within the two directions
1478 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1482 switch (keys->control.addr_type) {
1483 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1484 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1485 (__force u32)keys->addrs.v4addrs.src;
1486 if ((addr_diff < 0) ||
1488 ((__force u16)keys->ports.dst <
1489 (__force u16)keys->ports.src))) {
1490 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1491 swap(keys->ports.src, keys->ports.dst);
1494 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1495 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1496 &keys->addrs.v6addrs.src,
1497 sizeof(keys->addrs.v6addrs.dst));
1498 if ((addr_diff < 0) ||
1500 ((__force u16)keys->ports.dst <
1501 (__force u16)keys->ports.src))) {
1502 for (i = 0; i < 4; i++)
1503 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1504 keys->addrs.v6addrs.dst.s6_addr32[i]);
1505 swap(keys->ports.src, keys->ports.dst);
1511 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1512 const siphash_key_t *keyval)
1516 __flow_hash_consistentify(keys);
1518 hash = siphash(flow_keys_hash_start(keys),
1519 flow_keys_hash_length(keys), keyval);
1526 u32 flow_hash_from_keys(struct flow_keys *keys)
1528 __flow_hash_secret_init();
1529 return __flow_hash_from_keys(keys, &hashrnd);
1531 EXPORT_SYMBOL(flow_hash_from_keys);
1533 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1534 struct flow_keys *keys,
1535 const siphash_key_t *keyval)
1537 skb_flow_dissect_flow_keys(skb, keys,
1538 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1540 return __flow_hash_from_keys(keys, keyval);
1543 struct _flow_keys_digest_data {
1552 void make_flow_keys_digest(struct flow_keys_digest *digest,
1553 const struct flow_keys *flow)
1555 struct _flow_keys_digest_data *data =
1556 (struct _flow_keys_digest_data *)digest;
1558 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1560 memset(digest, 0, sizeof(*digest));
1562 data->n_proto = flow->basic.n_proto;
1563 data->ip_proto = flow->basic.ip_proto;
1564 data->ports = flow->ports.ports;
1565 data->src = flow->addrs.v4addrs.src;
1566 data->dst = flow->addrs.v4addrs.dst;
1568 EXPORT_SYMBOL(make_flow_keys_digest);
1570 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1572 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1574 struct flow_keys keys;
1576 __flow_hash_secret_init();
1578 memset(&keys, 0, sizeof(keys));
1579 __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1580 &keys, NULL, 0, 0, 0,
1581 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1583 return __flow_hash_from_keys(&keys, &hashrnd);
1585 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1588 * __skb_get_hash: calculate a flow hash
1589 * @skb: sk_buff to calculate flow hash from
1591 * This function calculates a flow hash based on src/dst addresses
1592 * and src/dst port numbers. Sets hash in skb to non-zero hash value
1593 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
1594 * if hash is a canonical 4-tuple hash over transport ports.
1596 void __skb_get_hash(struct sk_buff *skb)
1598 struct flow_keys keys;
1601 __flow_hash_secret_init();
1603 hash = ___skb_get_hash(skb, &keys, &hashrnd);
1605 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1607 EXPORT_SYMBOL(__skb_get_hash);
1609 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1610 const siphash_key_t *perturb)
1612 struct flow_keys keys;
1614 return ___skb_get_hash(skb, &keys, perturb);
1616 EXPORT_SYMBOL(skb_get_hash_perturb);
1618 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1619 const struct flow_keys_basic *keys, int hlen)
1621 u32 poff = keys->control.thoff;
1623 /* skip L4 headers for fragments after the first */
1624 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1625 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1628 switch (keys->basic.ip_proto) {
1630 /* access doff as u8 to avoid unaligned access */
1634 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1635 data, hlen, &_doff);
1639 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1643 case IPPROTO_UDPLITE:
1644 poff += sizeof(struct udphdr);
1646 /* For the rest, we do not really care about header
1647 * extensions at this point for now.
1650 poff += sizeof(struct icmphdr);
1652 case IPPROTO_ICMPV6:
1653 poff += sizeof(struct icmp6hdr);
1656 poff += sizeof(struct igmphdr);
1659 poff += sizeof(struct dccp_hdr);
1662 poff += sizeof(struct sctphdr);
1670 * skb_get_poff - get the offset to the payload
1671 * @skb: sk_buff to get the payload offset from
1673 * The function will get the offset to the payload as far as it could
1674 * be dissected. The main user is currently BPF, so that we can dynamically
1675 * truncate packets without needing to push actual payload to the user
1676 * space and can analyze headers only, instead.
1678 u32 skb_get_poff(const struct sk_buff *skb)
1680 struct flow_keys_basic keys;
1682 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1686 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1689 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1691 memset(keys, 0, sizeof(*keys));
1693 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1694 sizeof(keys->addrs.v6addrs.src));
1695 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1696 sizeof(keys->addrs.v6addrs.dst));
1697 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1698 keys->ports.src = fl6->fl6_sport;
1699 keys->ports.dst = fl6->fl6_dport;
1700 keys->keyid.keyid = fl6->fl6_gre_key;
1701 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1702 keys->basic.ip_proto = fl6->flowi6_proto;
1704 return flow_hash_from_keys(keys);
1706 EXPORT_SYMBOL(__get_hash_from_flowi6);
1708 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1710 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1711 .offset = offsetof(struct flow_keys, control),
1714 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1715 .offset = offsetof(struct flow_keys, basic),
1718 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1719 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1722 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1723 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1726 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1727 .offset = offsetof(struct flow_keys, addrs.tipckey),
1730 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1731 .offset = offsetof(struct flow_keys, ports),
1734 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1735 .offset = offsetof(struct flow_keys, vlan),
1738 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1739 .offset = offsetof(struct flow_keys, tags),
1742 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1743 .offset = offsetof(struct flow_keys, keyid),
1747 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1749 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1750 .offset = offsetof(struct flow_keys, control),
1753 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1754 .offset = offsetof(struct flow_keys, basic),
1757 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1758 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1761 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1762 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1765 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1766 .offset = offsetof(struct flow_keys, ports),
1770 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1772 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1773 .offset = offsetof(struct flow_keys, control),
1776 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1777 .offset = offsetof(struct flow_keys, basic),
1781 struct flow_dissector flow_keys_dissector __read_mostly;
1782 EXPORT_SYMBOL(flow_keys_dissector);
1784 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1785 EXPORT_SYMBOL(flow_keys_basic_dissector);
1787 static int __init init_default_flow_dissectors(void)
1789 skb_flow_dissector_init(&flow_keys_dissector,
1790 flow_keys_dissector_keys,
1791 ARRAY_SIZE(flow_keys_dissector_keys));
1792 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1793 flow_keys_dissector_symmetric_keys,
1794 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1795 skb_flow_dissector_init(&flow_keys_basic_dissector,
1796 flow_keys_basic_dissector_keys,
1797 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1800 core_initcall(init_default_flow_dissectors);