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>
35 static DEFINE_MUTEX(flow_dissector_mutex);
37 static void dissector_set_key(struct flow_dissector *flow_dissector,
38 enum flow_dissector_key_id key_id)
40 flow_dissector->used_keys |= (1 << key_id);
43 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
44 const struct flow_dissector_key *key,
45 unsigned int key_count)
49 memset(flow_dissector, 0, sizeof(*flow_dissector));
51 for (i = 0; i < key_count; i++, key++) {
52 /* User should make sure that every key target offset is withing
53 * boundaries of unsigned short.
55 BUG_ON(key->offset > USHRT_MAX);
56 BUG_ON(dissector_uses_key(flow_dissector,
59 dissector_set_key(flow_dissector, key->key_id);
60 flow_dissector->offset[key->key_id] = key->offset;
63 /* Ensure that the dissector always includes control and basic key.
64 * That way we are able to avoid handling lack of these in fast path.
66 BUG_ON(!dissector_uses_key(flow_dissector,
67 FLOW_DISSECTOR_KEY_CONTROL));
68 BUG_ON(!dissector_uses_key(flow_dissector,
69 FLOW_DISSECTOR_KEY_BASIC));
71 EXPORT_SYMBOL(skb_flow_dissector_init);
73 int skb_flow_dissector_prog_query(const union bpf_attr *attr,
74 union bpf_attr __user *uattr)
76 __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
77 u32 prog_id, prog_cnt = 0, flags = 0;
78 struct bpf_prog *attached;
81 if (attr->query.query_flags)
84 net = get_net_ns_by_fd(attr->query.target_fd);
89 attached = rcu_dereference(net->flow_dissector_prog);
92 prog_id = attached->aux->id;
98 if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
100 if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
103 if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
106 if (copy_to_user(prog_ids, &prog_id, sizeof(u32)))
112 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
113 struct bpf_prog *prog)
115 struct bpf_prog *attached;
119 net = current->nsproxy->net_ns;
120 mutex_lock(&flow_dissector_mutex);
122 if (net == &init_net) {
123 /* BPF flow dissector in the root namespace overrides
124 * any per-net-namespace one. When attaching to root,
125 * make sure we don't have any BPF program attached
126 * to the non-root namespaces.
133 if (rcu_access_pointer(ns->flow_dissector_prog)) {
139 /* Make sure root flow dissector is not attached
140 * when attaching to the non-root namespace.
142 if (rcu_access_pointer(init_net.flow_dissector_prog)) {
148 attached = rcu_dereference_protected(net->flow_dissector_prog,
149 lockdep_is_held(&flow_dissector_mutex));
150 if (attached == prog) {
151 /* The same program cannot be attached twice */
155 rcu_assign_pointer(net->flow_dissector_prog, prog);
157 bpf_prog_put(attached);
159 mutex_unlock(&flow_dissector_mutex);
163 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
165 struct bpf_prog *attached;
168 net = current->nsproxy->net_ns;
169 mutex_lock(&flow_dissector_mutex);
170 attached = rcu_dereference_protected(net->flow_dissector_prog,
171 lockdep_is_held(&flow_dissector_mutex));
173 mutex_unlock(&flow_dissector_mutex);
176 RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
177 bpf_prog_put(attached);
178 mutex_unlock(&flow_dissector_mutex);
183 * __skb_flow_get_ports - extract the upper layer ports and return them
184 * @skb: sk_buff to extract the ports from
185 * @thoff: transport header offset
186 * @ip_proto: protocol for which to get port offset
187 * @data: raw buffer pointer to the packet, if NULL use skb->data
188 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
190 * The function will try to retrieve the ports at offset thoff + poff where poff
191 * is the protocol port offset returned from proto_ports_offset
193 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
194 void *data, int hlen)
196 int poff = proto_ports_offset(ip_proto);
200 hlen = skb_headlen(skb);
204 __be32 *ports, _ports;
206 ports = __skb_header_pointer(skb, thoff + poff,
207 sizeof(_ports), data, hlen, &_ports);
214 EXPORT_SYMBOL(__skb_flow_get_ports);
216 static bool icmp_has_id(u8 type)
222 case ICMP_TIMESTAMPREPLY:
223 case ICMPV6_ECHO_REQUEST:
224 case ICMPV6_ECHO_REPLY:
232 * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
233 * @skb: sk_buff to extract from
234 * @key_icmp: struct flow_dissector_key_icmp to fill
235 * @data: raw buffer pointer to the packet
236 * @toff: offset to extract at
237 * @hlen: packet header length
239 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
240 struct flow_dissector_key_icmp *key_icmp,
241 void *data, int thoff, int hlen)
243 struct icmphdr *ih, _ih;
245 ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
249 key_icmp->type = ih->type;
250 key_icmp->code = ih->code;
252 /* As we use 0 to signal that the Id field is not present,
253 * avoid confusion with packets without such field
255 if (icmp_has_id(ih->type))
256 key_icmp->id = ih->un.echo.id ? : 1;
260 EXPORT_SYMBOL(skb_flow_get_icmp_tci);
262 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
263 * using skb_flow_get_icmp_tci().
265 static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
266 struct flow_dissector *flow_dissector,
267 void *target_container,
268 void *data, int thoff, int hlen)
270 struct flow_dissector_key_icmp *key_icmp;
272 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
275 key_icmp = skb_flow_dissector_target(flow_dissector,
276 FLOW_DISSECTOR_KEY_ICMP,
279 skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
282 void skb_flow_dissect_meta(const struct sk_buff *skb,
283 struct flow_dissector *flow_dissector,
284 void *target_container)
286 struct flow_dissector_key_meta *meta;
288 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
291 meta = skb_flow_dissector_target(flow_dissector,
292 FLOW_DISSECTOR_KEY_META,
294 meta->ingress_ifindex = skb->skb_iif;
296 EXPORT_SYMBOL(skb_flow_dissect_meta);
299 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
300 struct flow_dissector *flow_dissector,
301 void *target_container)
303 struct flow_dissector_key_control *ctrl;
305 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
308 ctrl = skb_flow_dissector_target(flow_dissector,
309 FLOW_DISSECTOR_KEY_ENC_CONTROL,
311 ctrl->addr_type = type;
315 skb_flow_dissect_ct(const struct sk_buff *skb,
316 struct flow_dissector *flow_dissector,
317 void *target_container,
321 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
322 struct flow_dissector_key_ct *key;
323 enum ip_conntrack_info ctinfo;
324 struct nf_conn_labels *cl;
327 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
330 ct = nf_ct_get(skb, &ctinfo);
334 key = skb_flow_dissector_target(flow_dissector,
335 FLOW_DISSECTOR_KEY_CT,
338 if (ctinfo < mapsize)
339 key->ct_state = ctinfo_map[ctinfo];
340 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
341 key->ct_zone = ct->zone.id;
343 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
344 key->ct_mark = ct->mark;
347 cl = nf_ct_labels_find(ct);
349 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
350 #endif /* CONFIG_NF_CONNTRACK */
352 EXPORT_SYMBOL(skb_flow_dissect_ct);
355 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
356 struct flow_dissector *flow_dissector,
357 void *target_container)
359 struct ip_tunnel_info *info;
360 struct ip_tunnel_key *key;
362 /* A quick check to see if there might be something to do. */
363 if (!dissector_uses_key(flow_dissector,
364 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
365 !dissector_uses_key(flow_dissector,
366 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
367 !dissector_uses_key(flow_dissector,
368 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
369 !dissector_uses_key(flow_dissector,
370 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
371 !dissector_uses_key(flow_dissector,
372 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
373 !dissector_uses_key(flow_dissector,
374 FLOW_DISSECTOR_KEY_ENC_IP) &&
375 !dissector_uses_key(flow_dissector,
376 FLOW_DISSECTOR_KEY_ENC_OPTS))
379 info = skb_tunnel_info(skb);
385 switch (ip_tunnel_info_af(info)) {
387 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
390 if (dissector_uses_key(flow_dissector,
391 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
392 struct flow_dissector_key_ipv4_addrs *ipv4;
394 ipv4 = skb_flow_dissector_target(flow_dissector,
395 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
397 ipv4->src = key->u.ipv4.src;
398 ipv4->dst = key->u.ipv4.dst;
402 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
405 if (dissector_uses_key(flow_dissector,
406 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
407 struct flow_dissector_key_ipv6_addrs *ipv6;
409 ipv6 = skb_flow_dissector_target(flow_dissector,
410 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
412 ipv6->src = key->u.ipv6.src;
413 ipv6->dst = key->u.ipv6.dst;
418 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
419 struct flow_dissector_key_keyid *keyid;
421 keyid = skb_flow_dissector_target(flow_dissector,
422 FLOW_DISSECTOR_KEY_ENC_KEYID,
424 keyid->keyid = tunnel_id_to_key32(key->tun_id);
427 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
428 struct flow_dissector_key_ports *tp;
430 tp = skb_flow_dissector_target(flow_dissector,
431 FLOW_DISSECTOR_KEY_ENC_PORTS,
433 tp->src = key->tp_src;
434 tp->dst = key->tp_dst;
437 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
438 struct flow_dissector_key_ip *ip;
440 ip = skb_flow_dissector_target(flow_dissector,
441 FLOW_DISSECTOR_KEY_ENC_IP,
447 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
448 struct flow_dissector_key_enc_opts *enc_opt;
450 enc_opt = skb_flow_dissector_target(flow_dissector,
451 FLOW_DISSECTOR_KEY_ENC_OPTS,
454 if (info->options_len) {
455 enc_opt->len = info->options_len;
456 ip_tunnel_info_opts_get(enc_opt->data, info);
457 enc_opt->dst_opt_type = info->key.tun_flags &
458 TUNNEL_OPTIONS_PRESENT;
462 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
464 static enum flow_dissect_ret
465 __skb_flow_dissect_mpls(const struct sk_buff *skb,
466 struct flow_dissector *flow_dissector,
467 void *target_container, void *data, int nhoff, int hlen)
469 struct flow_dissector_key_keyid *key_keyid;
470 struct mpls_label *hdr, _hdr[2];
473 if (!dissector_uses_key(flow_dissector,
474 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
475 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
476 return FLOW_DISSECT_RET_OUT_GOOD;
478 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
481 return FLOW_DISSECT_RET_OUT_BAD;
483 entry = ntohl(hdr[0].entry);
484 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
486 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
487 struct flow_dissector_key_mpls *key_mpls;
489 key_mpls = skb_flow_dissector_target(flow_dissector,
490 FLOW_DISSECTOR_KEY_MPLS,
492 key_mpls->mpls_label = label;
493 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
494 >> MPLS_LS_TTL_SHIFT;
495 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
497 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
501 if (label == MPLS_LABEL_ENTROPY) {
502 key_keyid = skb_flow_dissector_target(flow_dissector,
503 FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
505 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
507 return FLOW_DISSECT_RET_OUT_GOOD;
510 static enum flow_dissect_ret
511 __skb_flow_dissect_arp(const struct sk_buff *skb,
512 struct flow_dissector *flow_dissector,
513 void *target_container, void *data, int nhoff, int hlen)
515 struct flow_dissector_key_arp *key_arp;
517 unsigned char ar_sha[ETH_ALEN];
518 unsigned char ar_sip[4];
519 unsigned char ar_tha[ETH_ALEN];
520 unsigned char ar_tip[4];
521 } *arp_eth, _arp_eth;
522 const struct arphdr *arp;
525 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
526 return FLOW_DISSECT_RET_OUT_GOOD;
528 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
531 return FLOW_DISSECT_RET_OUT_BAD;
533 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
534 arp->ar_pro != htons(ETH_P_IP) ||
535 arp->ar_hln != ETH_ALEN ||
537 (arp->ar_op != htons(ARPOP_REPLY) &&
538 arp->ar_op != htons(ARPOP_REQUEST)))
539 return FLOW_DISSECT_RET_OUT_BAD;
541 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
542 sizeof(_arp_eth), data,
545 return FLOW_DISSECT_RET_OUT_BAD;
547 key_arp = skb_flow_dissector_target(flow_dissector,
548 FLOW_DISSECTOR_KEY_ARP,
551 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
552 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
554 /* Only store the lower byte of the opcode;
555 * this covers ARPOP_REPLY and ARPOP_REQUEST.
557 key_arp->op = ntohs(arp->ar_op) & 0xff;
559 ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
560 ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
562 return FLOW_DISSECT_RET_OUT_GOOD;
565 static enum flow_dissect_ret
566 __skb_flow_dissect_gre(const struct sk_buff *skb,
567 struct flow_dissector_key_control *key_control,
568 struct flow_dissector *flow_dissector,
569 void *target_container, void *data,
570 __be16 *p_proto, int *p_nhoff, int *p_hlen,
573 struct flow_dissector_key_keyid *key_keyid;
574 struct gre_base_hdr *hdr, _hdr;
578 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
579 data, *p_hlen, &_hdr);
581 return FLOW_DISSECT_RET_OUT_BAD;
583 /* Only look inside GRE without routing */
584 if (hdr->flags & GRE_ROUTING)
585 return FLOW_DISSECT_RET_OUT_GOOD;
587 /* Only look inside GRE for version 0 and 1 */
588 gre_ver = ntohs(hdr->flags & GRE_VERSION);
590 return FLOW_DISSECT_RET_OUT_GOOD;
592 *p_proto = hdr->protocol;
594 /* Version1 must be PPTP, and check the flags */
595 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
596 return FLOW_DISSECT_RET_OUT_GOOD;
599 offset += sizeof(struct gre_base_hdr);
601 if (hdr->flags & GRE_CSUM)
602 offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
603 FIELD_SIZEOF(struct gre_full_hdr, reserved1);
605 if (hdr->flags & GRE_KEY) {
609 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
611 data, *p_hlen, &_keyid);
613 return FLOW_DISSECT_RET_OUT_BAD;
615 if (dissector_uses_key(flow_dissector,
616 FLOW_DISSECTOR_KEY_GRE_KEYID)) {
617 key_keyid = skb_flow_dissector_target(flow_dissector,
618 FLOW_DISSECTOR_KEY_GRE_KEYID,
621 key_keyid->keyid = *keyid;
623 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
625 offset += FIELD_SIZEOF(struct gre_full_hdr, key);
628 if (hdr->flags & GRE_SEQ)
629 offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
632 if (*p_proto == htons(ETH_P_TEB)) {
633 const struct ethhdr *eth;
636 eth = __skb_header_pointer(skb, *p_nhoff + offset,
638 data, *p_hlen, &_eth);
640 return FLOW_DISSECT_RET_OUT_BAD;
641 *p_proto = eth->h_proto;
642 offset += sizeof(*eth);
644 /* Cap headers that we access via pointers at the
645 * end of the Ethernet header as our maximum alignment
646 * at that point is only 2 bytes.
649 *p_hlen = *p_nhoff + offset;
651 } else { /* version 1, must be PPTP */
652 u8 _ppp_hdr[PPP_HDRLEN];
655 if (hdr->flags & GRE_ACK)
656 offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
658 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
660 data, *p_hlen, _ppp_hdr);
662 return FLOW_DISSECT_RET_OUT_BAD;
664 switch (PPP_PROTOCOL(ppp_hdr)) {
666 *p_proto = htons(ETH_P_IP);
669 *p_proto = htons(ETH_P_IPV6);
672 /* Could probably catch some more like MPLS */
676 offset += PPP_HDRLEN;
680 key_control->flags |= FLOW_DIS_ENCAPSULATION;
681 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
682 return FLOW_DISSECT_RET_OUT_GOOD;
684 return FLOW_DISSECT_RET_PROTO_AGAIN;
688 * __skb_flow_dissect_batadv() - dissect batman-adv header
689 * @skb: sk_buff to with the batman-adv header
690 * @key_control: flow dissectors control key
691 * @data: raw buffer pointer to the packet, if NULL use skb->data
692 * @p_proto: pointer used to update the protocol to process next
693 * @p_nhoff: pointer used to update inner network header offset
694 * @hlen: packet header length
695 * @flags: any combination of FLOW_DISSECTOR_F_*
697 * ETH_P_BATMAN packets are tried to be dissected. Only
698 * &struct batadv_unicast packets are actually processed because they contain an
699 * inner ethernet header and are usually followed by actual network header. This
700 * allows the flow dissector to continue processing the packet.
702 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
703 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
704 * otherwise FLOW_DISSECT_RET_OUT_BAD
706 static enum flow_dissect_ret
707 __skb_flow_dissect_batadv(const struct sk_buff *skb,
708 struct flow_dissector_key_control *key_control,
709 void *data, __be16 *p_proto, int *p_nhoff, int hlen,
713 struct batadv_unicast_packet batadv_unicast;
717 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
720 return FLOW_DISSECT_RET_OUT_BAD;
722 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
723 return FLOW_DISSECT_RET_OUT_BAD;
725 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
726 return FLOW_DISSECT_RET_OUT_BAD;
728 *p_proto = hdr->eth.h_proto;
729 *p_nhoff += sizeof(*hdr);
731 key_control->flags |= FLOW_DIS_ENCAPSULATION;
732 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
733 return FLOW_DISSECT_RET_OUT_GOOD;
735 return FLOW_DISSECT_RET_PROTO_AGAIN;
739 __skb_flow_dissect_tcp(const struct sk_buff *skb,
740 struct flow_dissector *flow_dissector,
741 void *target_container, void *data, int thoff, int hlen)
743 struct flow_dissector_key_tcp *key_tcp;
744 struct tcphdr *th, _th;
746 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
749 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
753 if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
756 key_tcp = skb_flow_dissector_target(flow_dissector,
757 FLOW_DISSECTOR_KEY_TCP,
759 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
763 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
764 struct flow_dissector *flow_dissector,
765 void *target_container, void *data, const struct iphdr *iph)
767 struct flow_dissector_key_ip *key_ip;
769 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
772 key_ip = skb_flow_dissector_target(flow_dissector,
773 FLOW_DISSECTOR_KEY_IP,
775 key_ip->tos = iph->tos;
776 key_ip->ttl = iph->ttl;
780 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
781 struct flow_dissector *flow_dissector,
782 void *target_container, void *data, const struct ipv6hdr *iph)
784 struct flow_dissector_key_ip *key_ip;
786 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
789 key_ip = skb_flow_dissector_target(flow_dissector,
790 FLOW_DISSECTOR_KEY_IP,
792 key_ip->tos = ipv6_get_dsfield(iph);
793 key_ip->ttl = iph->hop_limit;
796 /* Maximum number of protocol headers that can be parsed in
799 #define MAX_FLOW_DISSECT_HDRS 15
801 static bool skb_flow_dissect_allowed(int *num_hdrs)
805 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
808 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
809 struct flow_dissector *flow_dissector,
810 void *target_container)
812 struct flow_dissector_key_control *key_control;
813 struct flow_dissector_key_basic *key_basic;
814 struct flow_dissector_key_addrs *key_addrs;
815 struct flow_dissector_key_ports *key_ports;
816 struct flow_dissector_key_tags *key_tags;
818 key_control = skb_flow_dissector_target(flow_dissector,
819 FLOW_DISSECTOR_KEY_CONTROL,
821 key_control->thoff = flow_keys->thoff;
822 if (flow_keys->is_frag)
823 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
824 if (flow_keys->is_first_frag)
825 key_control->flags |= FLOW_DIS_FIRST_FRAG;
826 if (flow_keys->is_encap)
827 key_control->flags |= FLOW_DIS_ENCAPSULATION;
829 key_basic = skb_flow_dissector_target(flow_dissector,
830 FLOW_DISSECTOR_KEY_BASIC,
832 key_basic->n_proto = flow_keys->n_proto;
833 key_basic->ip_proto = flow_keys->ip_proto;
835 if (flow_keys->addr_proto == ETH_P_IP &&
836 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
837 key_addrs = skb_flow_dissector_target(flow_dissector,
838 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
840 key_addrs->v4addrs.src = flow_keys->ipv4_src;
841 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
842 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
843 } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
844 dissector_uses_key(flow_dissector,
845 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
846 key_addrs = skb_flow_dissector_target(flow_dissector,
847 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
849 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
850 sizeof(key_addrs->v6addrs));
851 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
854 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
855 key_ports = skb_flow_dissector_target(flow_dissector,
856 FLOW_DISSECTOR_KEY_PORTS,
858 key_ports->src = flow_keys->sport;
859 key_ports->dst = flow_keys->dport;
862 if (dissector_uses_key(flow_dissector,
863 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
864 key_tags = skb_flow_dissector_target(flow_dissector,
865 FLOW_DISSECTOR_KEY_FLOW_LABEL,
867 key_tags->flow_label = ntohl(flow_keys->flow_label);
871 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
872 __be16 proto, int nhoff, int hlen, unsigned int flags)
874 struct bpf_flow_keys *flow_keys = ctx->flow_keys;
877 /* Pass parameters to the BPF program */
878 memset(flow_keys, 0, sizeof(*flow_keys));
879 flow_keys->n_proto = proto;
880 flow_keys->nhoff = nhoff;
881 flow_keys->thoff = flow_keys->nhoff;
883 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
884 (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
885 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
886 (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
887 BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
888 (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
889 flow_keys->flags = flags;
892 result = BPF_PROG_RUN(prog, ctx);
895 flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
896 flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
897 flow_keys->nhoff, hlen);
899 return result == BPF_OK;
903 * __skb_flow_dissect - extract the flow_keys struct and return it
904 * @net: associated network namespace, derived from @skb if NULL
905 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
906 * @flow_dissector: list of keys to dissect
907 * @target_container: target structure to put dissected values into
908 * @data: raw buffer pointer to the packet, if NULL use skb->data
909 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
910 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
911 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
912 * @flags: flags that control the dissection process, e.g.
913 * FLOW_DISSECTOR_F_STOP_AT_ENCAP.
915 * The function will try to retrieve individual keys into target specified
916 * by flow_dissector from either the skbuff or a raw buffer specified by the
919 * Caller must take care of zeroing target container memory.
921 bool __skb_flow_dissect(const struct net *net,
922 const struct sk_buff *skb,
923 struct flow_dissector *flow_dissector,
924 void *target_container,
925 void *data, __be16 proto, int nhoff, int hlen,
928 struct flow_dissector_key_control *key_control;
929 struct flow_dissector_key_basic *key_basic;
930 struct flow_dissector_key_addrs *key_addrs;
931 struct flow_dissector_key_ports *key_ports;
932 struct flow_dissector_key_tags *key_tags;
933 struct flow_dissector_key_vlan *key_vlan;
934 struct bpf_prog *attached = NULL;
935 enum flow_dissect_ret fdret;
936 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
943 proto = skb_vlan_tag_present(skb) ?
944 skb->vlan_proto : skb->protocol;
945 nhoff = skb_network_offset(skb);
946 hlen = skb_headlen(skb);
947 #if IS_ENABLED(CONFIG_NET_DSA)
948 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
949 const struct dsa_device_ops *ops;
952 ops = skb->dev->dsa_ptr->tag_ops;
953 if (ops->flow_dissect &&
954 !ops->flow_dissect(skb, &proto, &offset)) {
962 /* It is ensured by skb_flow_dissector_init() that control key will
965 key_control = skb_flow_dissector_target(flow_dissector,
966 FLOW_DISSECTOR_KEY_CONTROL,
969 /* It is ensured by skb_flow_dissector_init() that basic key will
972 key_basic = skb_flow_dissector_target(flow_dissector,
973 FLOW_DISSECTOR_KEY_BASIC,
979 net = dev_net(skb->dev);
981 net = sock_net(skb->sk);
988 attached = rcu_dereference(init_net.flow_dissector_prog);
991 attached = rcu_dereference(net->flow_dissector_prog);
994 struct bpf_flow_keys flow_keys;
995 struct bpf_flow_dissector ctx = {
996 .flow_keys = &flow_keys,
998 .data_end = data + hlen,
1000 __be16 n_proto = proto;
1004 /* we can't use 'proto' in the skb case
1005 * because it might be set to skb->vlan_proto
1006 * which has been pulled from the data
1008 n_proto = skb->protocol;
1011 ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
1013 __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1021 if (dissector_uses_key(flow_dissector,
1022 FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1023 struct ethhdr *eth = eth_hdr(skb);
1024 struct flow_dissector_key_eth_addrs *key_eth_addrs;
1026 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1027 FLOW_DISSECTOR_KEY_ETH_ADDRS,
1029 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
1033 fdret = FLOW_DISSECT_RET_CONTINUE;
1036 case htons(ETH_P_IP): {
1037 const struct iphdr *iph;
1040 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1041 if (!iph || iph->ihl < 5) {
1042 fdret = FLOW_DISSECT_RET_OUT_BAD;
1046 nhoff += iph->ihl * 4;
1048 ip_proto = iph->protocol;
1050 if (dissector_uses_key(flow_dissector,
1051 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1052 key_addrs = skb_flow_dissector_target(flow_dissector,
1053 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1056 memcpy(&key_addrs->v4addrs, &iph->saddr,
1057 sizeof(key_addrs->v4addrs));
1058 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1061 if (ip_is_fragment(iph)) {
1062 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1064 if (iph->frag_off & htons(IP_OFFSET)) {
1065 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1068 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1070 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1071 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1077 __skb_flow_dissect_ipv4(skb, flow_dissector,
1078 target_container, data, iph);
1082 case htons(ETH_P_IPV6): {
1083 const struct ipv6hdr *iph;
1084 struct ipv6hdr _iph;
1086 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1088 fdret = FLOW_DISSECT_RET_OUT_BAD;
1092 ip_proto = iph->nexthdr;
1093 nhoff += sizeof(struct ipv6hdr);
1095 if (dissector_uses_key(flow_dissector,
1096 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1097 key_addrs = skb_flow_dissector_target(flow_dissector,
1098 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1101 memcpy(&key_addrs->v6addrs, &iph->saddr,
1102 sizeof(key_addrs->v6addrs));
1103 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1106 if ((dissector_uses_key(flow_dissector,
1107 FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1108 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1109 ip6_flowlabel(iph)) {
1110 __be32 flow_label = ip6_flowlabel(iph);
1112 if (dissector_uses_key(flow_dissector,
1113 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1114 key_tags = skb_flow_dissector_target(flow_dissector,
1115 FLOW_DISSECTOR_KEY_FLOW_LABEL,
1117 key_tags->flow_label = ntohl(flow_label);
1119 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1120 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1125 __skb_flow_dissect_ipv6(skb, flow_dissector,
1126 target_container, data, iph);
1130 case htons(ETH_P_8021AD):
1131 case htons(ETH_P_8021Q): {
1132 const struct vlan_hdr *vlan = NULL;
1133 struct vlan_hdr _vlan;
1134 __be16 saved_vlan_tpid = proto;
1136 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1137 skb && skb_vlan_tag_present(skb)) {
1138 proto = skb->protocol;
1140 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1141 data, hlen, &_vlan);
1143 fdret = FLOW_DISSECT_RET_OUT_BAD;
1147 proto = vlan->h_vlan_encapsulated_proto;
1148 nhoff += sizeof(*vlan);
1151 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1152 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1153 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1154 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1156 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1160 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1161 key_vlan = skb_flow_dissector_target(flow_dissector,
1166 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1167 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1169 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1171 key_vlan->vlan_priority =
1172 (ntohs(vlan->h_vlan_TCI) &
1173 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1175 key_vlan->vlan_tpid = saved_vlan_tpid;
1178 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1181 case htons(ETH_P_PPP_SES): {
1183 struct pppoe_hdr hdr;
1186 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1188 fdret = FLOW_DISSECT_RET_OUT_BAD;
1193 nhoff += PPPOE_SES_HLEN;
1196 proto = htons(ETH_P_IP);
1197 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1199 case htons(PPP_IPV6):
1200 proto = htons(ETH_P_IPV6);
1201 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1204 fdret = FLOW_DISSECT_RET_OUT_BAD;
1209 case htons(ETH_P_TIPC): {
1210 struct tipc_basic_hdr *hdr, _hdr;
1212 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1215 fdret = FLOW_DISSECT_RET_OUT_BAD;
1219 if (dissector_uses_key(flow_dissector,
1220 FLOW_DISSECTOR_KEY_TIPC)) {
1221 key_addrs = skb_flow_dissector_target(flow_dissector,
1222 FLOW_DISSECTOR_KEY_TIPC,
1224 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1225 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1227 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1231 case htons(ETH_P_MPLS_UC):
1232 case htons(ETH_P_MPLS_MC):
1233 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1234 target_container, data,
1237 case htons(ETH_P_FCOE):
1238 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1239 fdret = FLOW_DISSECT_RET_OUT_BAD;
1243 nhoff += FCOE_HEADER_LEN;
1244 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1247 case htons(ETH_P_ARP):
1248 case htons(ETH_P_RARP):
1249 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1250 target_container, data,
1254 case htons(ETH_P_BATMAN):
1255 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1256 &proto, &nhoff, hlen, flags);
1260 fdret = FLOW_DISSECT_RET_OUT_BAD;
1264 /* Process result of proto processing */
1266 case FLOW_DISSECT_RET_OUT_GOOD:
1268 case FLOW_DISSECT_RET_PROTO_AGAIN:
1269 if (skb_flow_dissect_allowed(&num_hdrs))
1272 case FLOW_DISSECT_RET_CONTINUE:
1273 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1275 case FLOW_DISSECT_RET_OUT_BAD:
1281 fdret = FLOW_DISSECT_RET_CONTINUE;
1285 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1286 target_container, data,
1287 &proto, &nhoff, &hlen, flags);
1291 case NEXTHDR_ROUTING:
1292 case NEXTHDR_DEST: {
1293 u8 _opthdr[2], *opthdr;
1295 if (proto != htons(ETH_P_IPV6))
1298 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1299 data, hlen, &_opthdr);
1301 fdret = FLOW_DISSECT_RET_OUT_BAD;
1305 ip_proto = opthdr[0];
1306 nhoff += (opthdr[1] + 1) << 3;
1308 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1311 case NEXTHDR_FRAGMENT: {
1312 struct frag_hdr _fh, *fh;
1314 if (proto != htons(ETH_P_IPV6))
1317 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1321 fdret = FLOW_DISSECT_RET_OUT_BAD;
1325 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1327 nhoff += sizeof(_fh);
1328 ip_proto = fh->nexthdr;
1330 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1331 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1332 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1333 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1338 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1342 proto = htons(ETH_P_IP);
1344 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1345 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1346 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1350 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1354 proto = htons(ETH_P_IPV6);
1356 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1357 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1358 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1362 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1367 proto = htons(ETH_P_MPLS_UC);
1368 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1372 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1377 case IPPROTO_ICMPV6:
1378 __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1386 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1387 !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1388 key_ports = skb_flow_dissector_target(flow_dissector,
1389 FLOW_DISSECTOR_KEY_PORTS,
1391 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1395 /* Process result of IP proto processing */
1397 case FLOW_DISSECT_RET_PROTO_AGAIN:
1398 if (skb_flow_dissect_allowed(&num_hdrs))
1401 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1402 if (skb_flow_dissect_allowed(&num_hdrs))
1403 goto ip_proto_again;
1405 case FLOW_DISSECT_RET_OUT_GOOD:
1406 case FLOW_DISSECT_RET_CONTINUE:
1408 case FLOW_DISSECT_RET_OUT_BAD:
1417 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1418 key_basic->n_proto = proto;
1419 key_basic->ip_proto = ip_proto;
1427 EXPORT_SYMBOL(__skb_flow_dissect);
1429 static siphash_key_t hashrnd __read_mostly;
1430 static __always_inline void __flow_hash_secret_init(void)
1432 net_get_random_once(&hashrnd, sizeof(hashrnd));
1435 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1437 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1438 return &flow->FLOW_KEYS_HASH_START_FIELD;
1441 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1443 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1445 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1447 switch (flow->control.addr_type) {
1448 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1449 diff -= sizeof(flow->addrs.v4addrs);
1451 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1452 diff -= sizeof(flow->addrs.v6addrs);
1454 case FLOW_DISSECTOR_KEY_TIPC:
1455 diff -= sizeof(flow->addrs.tipckey);
1458 return sizeof(*flow) - diff;
1461 __be32 flow_get_u32_src(const struct flow_keys *flow)
1463 switch (flow->control.addr_type) {
1464 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1465 return flow->addrs.v4addrs.src;
1466 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1467 return (__force __be32)ipv6_addr_hash(
1468 &flow->addrs.v6addrs.src);
1469 case FLOW_DISSECTOR_KEY_TIPC:
1470 return flow->addrs.tipckey.key;
1475 EXPORT_SYMBOL(flow_get_u32_src);
1477 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1479 switch (flow->control.addr_type) {
1480 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1481 return flow->addrs.v4addrs.dst;
1482 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1483 return (__force __be32)ipv6_addr_hash(
1484 &flow->addrs.v6addrs.dst);
1489 EXPORT_SYMBOL(flow_get_u32_dst);
1491 /* Sort the source and destination IP (and the ports if the IP are the same),
1492 * to have consistent hash within the two directions
1494 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1498 switch (keys->control.addr_type) {
1499 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1500 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1501 (__force u32)keys->addrs.v4addrs.src;
1502 if ((addr_diff < 0) ||
1504 ((__force u16)keys->ports.dst <
1505 (__force u16)keys->ports.src))) {
1506 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1507 swap(keys->ports.src, keys->ports.dst);
1510 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1511 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1512 &keys->addrs.v6addrs.src,
1513 sizeof(keys->addrs.v6addrs.dst));
1514 if ((addr_diff < 0) ||
1516 ((__force u16)keys->ports.dst <
1517 (__force u16)keys->ports.src))) {
1518 for (i = 0; i < 4; i++)
1519 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1520 keys->addrs.v6addrs.dst.s6_addr32[i]);
1521 swap(keys->ports.src, keys->ports.dst);
1527 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1528 const siphash_key_t *keyval)
1532 __flow_hash_consistentify(keys);
1534 hash = siphash(flow_keys_hash_start(keys),
1535 flow_keys_hash_length(keys), keyval);
1542 u32 flow_hash_from_keys(struct flow_keys *keys)
1544 __flow_hash_secret_init();
1545 return __flow_hash_from_keys(keys, &hashrnd);
1547 EXPORT_SYMBOL(flow_hash_from_keys);
1549 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1550 struct flow_keys *keys,
1551 const siphash_key_t *keyval)
1553 skb_flow_dissect_flow_keys(skb, keys,
1554 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1556 return __flow_hash_from_keys(keys, keyval);
1559 struct _flow_keys_digest_data {
1568 void make_flow_keys_digest(struct flow_keys_digest *digest,
1569 const struct flow_keys *flow)
1571 struct _flow_keys_digest_data *data =
1572 (struct _flow_keys_digest_data *)digest;
1574 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1576 memset(digest, 0, sizeof(*digest));
1578 data->n_proto = flow->basic.n_proto;
1579 data->ip_proto = flow->basic.ip_proto;
1580 data->ports = flow->ports.ports;
1581 data->src = flow->addrs.v4addrs.src;
1582 data->dst = flow->addrs.v4addrs.dst;
1584 EXPORT_SYMBOL(make_flow_keys_digest);
1586 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1588 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1590 struct flow_keys keys;
1592 __flow_hash_secret_init();
1594 memset(&keys, 0, sizeof(keys));
1595 __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1596 &keys, NULL, 0, 0, 0,
1597 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1599 return __flow_hash_from_keys(&keys, &hashrnd);
1601 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1604 * __skb_get_hash: calculate a flow hash
1605 * @skb: sk_buff to calculate flow hash from
1607 * This function calculates a flow hash based on src/dst addresses
1608 * and src/dst port numbers. Sets hash in skb to non-zero hash value
1609 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
1610 * if hash is a canonical 4-tuple hash over transport ports.
1612 void __skb_get_hash(struct sk_buff *skb)
1614 struct flow_keys keys;
1617 __flow_hash_secret_init();
1619 hash = ___skb_get_hash(skb, &keys, &hashrnd);
1621 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1623 EXPORT_SYMBOL(__skb_get_hash);
1625 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1626 const siphash_key_t *perturb)
1628 struct flow_keys keys;
1630 return ___skb_get_hash(skb, &keys, perturb);
1632 EXPORT_SYMBOL(skb_get_hash_perturb);
1634 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1635 const struct flow_keys_basic *keys, int hlen)
1637 u32 poff = keys->control.thoff;
1639 /* skip L4 headers for fragments after the first */
1640 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1641 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1644 switch (keys->basic.ip_proto) {
1646 /* access doff as u8 to avoid unaligned access */
1650 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1651 data, hlen, &_doff);
1655 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1659 case IPPROTO_UDPLITE:
1660 poff += sizeof(struct udphdr);
1662 /* For the rest, we do not really care about header
1663 * extensions at this point for now.
1666 poff += sizeof(struct icmphdr);
1668 case IPPROTO_ICMPV6:
1669 poff += sizeof(struct icmp6hdr);
1672 poff += sizeof(struct igmphdr);
1675 poff += sizeof(struct dccp_hdr);
1678 poff += sizeof(struct sctphdr);
1686 * skb_get_poff - get the offset to the payload
1687 * @skb: sk_buff to get the payload offset from
1689 * The function will get the offset to the payload as far as it could
1690 * be dissected. The main user is currently BPF, so that we can dynamically
1691 * truncate packets without needing to push actual payload to the user
1692 * space and can analyze headers only, instead.
1694 u32 skb_get_poff(const struct sk_buff *skb)
1696 struct flow_keys_basic keys;
1698 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1702 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1705 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1707 memset(keys, 0, sizeof(*keys));
1709 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1710 sizeof(keys->addrs.v6addrs.src));
1711 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1712 sizeof(keys->addrs.v6addrs.dst));
1713 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1714 keys->ports.src = fl6->fl6_sport;
1715 keys->ports.dst = fl6->fl6_dport;
1716 keys->keyid.keyid = fl6->fl6_gre_key;
1717 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1718 keys->basic.ip_proto = fl6->flowi6_proto;
1720 return flow_hash_from_keys(keys);
1722 EXPORT_SYMBOL(__get_hash_from_flowi6);
1724 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1726 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1727 .offset = offsetof(struct flow_keys, control),
1730 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1731 .offset = offsetof(struct flow_keys, basic),
1734 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1735 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1738 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1739 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1742 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1743 .offset = offsetof(struct flow_keys, addrs.tipckey),
1746 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1747 .offset = offsetof(struct flow_keys, ports),
1750 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1751 .offset = offsetof(struct flow_keys, vlan),
1754 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1755 .offset = offsetof(struct flow_keys, tags),
1758 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1759 .offset = offsetof(struct flow_keys, keyid),
1763 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1765 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1766 .offset = offsetof(struct flow_keys, control),
1769 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1770 .offset = offsetof(struct flow_keys, basic),
1773 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1774 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1777 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1778 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1781 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1782 .offset = offsetof(struct flow_keys, ports),
1786 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1788 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1789 .offset = offsetof(struct flow_keys, control),
1792 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1793 .offset = offsetof(struct flow_keys, basic),
1797 struct flow_dissector flow_keys_dissector __read_mostly;
1798 EXPORT_SYMBOL(flow_keys_dissector);
1800 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1801 EXPORT_SYMBOL(flow_keys_basic_dissector);
1803 static int __init init_default_flow_dissectors(void)
1805 skb_flow_dissector_init(&flow_keys_dissector,
1806 flow_keys_dissector_keys,
1807 ARRAY_SIZE(flow_keys_dissector_keys));
1808 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1809 flow_keys_dissector_symmetric_keys,
1810 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1811 skb_flow_dissector_init(&flow_keys_basic_dissector,
1812 flow_keys_basic_dissector_keys,
1813 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1817 core_initcall(init_default_flow_dissectors);