1 #include <linux/kernel.h>
2 #include <linux/skbuff.h>
3 #include <linux/export.h>
5 #include <linux/ipv6.h>
6 #include <linux/if_vlan.h>
8 #include <net/dst_metadata.h>
14 #include <linux/igmp.h>
15 #include <linux/icmp.h>
16 #include <linux/sctp.h>
17 #include <linux/dccp.h>
18 #include <linux/if_tunnel.h>
19 #include <linux/if_pppox.h>
20 #include <linux/ppp_defs.h>
21 #include <linux/stddef.h>
22 #include <linux/if_ether.h>
23 #include <linux/mpls.h>
24 #include <linux/tcp.h>
25 #include <net/flow_dissector.h>
26 #include <scsi/fc/fc_fcoe.h>
27 #include <uapi/linux/batadv_packet.h>
28 #include <linux/bpf.h>
30 static DEFINE_MUTEX(flow_dissector_mutex);
32 static void dissector_set_key(struct flow_dissector *flow_dissector,
33 enum flow_dissector_key_id key_id)
35 flow_dissector->used_keys |= (1 << key_id);
38 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
39 const struct flow_dissector_key *key,
40 unsigned int key_count)
44 memset(flow_dissector, 0, sizeof(*flow_dissector));
46 for (i = 0; i < key_count; i++, key++) {
47 /* User should make sure that every key target offset is withing
48 * boundaries of unsigned short.
50 BUG_ON(key->offset > USHRT_MAX);
51 BUG_ON(dissector_uses_key(flow_dissector,
54 dissector_set_key(flow_dissector, key->key_id);
55 flow_dissector->offset[key->key_id] = key->offset;
58 /* Ensure that the dissector always includes control and basic key.
59 * That way we are able to avoid handling lack of these in fast path.
61 BUG_ON(!dissector_uses_key(flow_dissector,
62 FLOW_DISSECTOR_KEY_CONTROL));
63 BUG_ON(!dissector_uses_key(flow_dissector,
64 FLOW_DISSECTOR_KEY_BASIC));
66 EXPORT_SYMBOL(skb_flow_dissector_init);
68 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
69 struct bpf_prog *prog)
71 struct bpf_prog *attached;
74 net = current->nsproxy->net_ns;
75 mutex_lock(&flow_dissector_mutex);
76 attached = rcu_dereference_protected(net->flow_dissector_prog,
77 lockdep_is_held(&flow_dissector_mutex));
79 /* Only one BPF program can be attached at a time */
80 mutex_unlock(&flow_dissector_mutex);
83 rcu_assign_pointer(net->flow_dissector_prog, prog);
84 mutex_unlock(&flow_dissector_mutex);
88 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
90 struct bpf_prog *attached;
93 net = current->nsproxy->net_ns;
94 mutex_lock(&flow_dissector_mutex);
95 attached = rcu_dereference_protected(net->flow_dissector_prog,
96 lockdep_is_held(&flow_dissector_mutex));
98 mutex_unlock(&flow_dissector_mutex);
101 bpf_prog_put(attached);
102 RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
103 mutex_unlock(&flow_dissector_mutex);
107 * skb_flow_get_be16 - extract be16 entity
108 * @skb: sk_buff to extract from
109 * @poff: offset to extract at
110 * @data: raw buffer pointer to the packet
111 * @hlen: packet header length
113 * The function will try to retrieve a be32 entity at
116 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
117 void *data, int hlen)
121 u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
129 * __skb_flow_get_ports - extract the upper layer ports and return them
130 * @skb: sk_buff to extract the ports from
131 * @thoff: transport header offset
132 * @ip_proto: protocol for which to get port offset
133 * @data: raw buffer pointer to the packet, if NULL use skb->data
134 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
136 * The function will try to retrieve the ports at offset thoff + poff where poff
137 * is the protocol port offset returned from proto_ports_offset
139 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
140 void *data, int hlen)
142 int poff = proto_ports_offset(ip_proto);
146 hlen = skb_headlen(skb);
150 __be32 *ports, _ports;
152 ports = __skb_header_pointer(skb, thoff + poff,
153 sizeof(_ports), data, hlen, &_ports);
160 EXPORT_SYMBOL(__skb_flow_get_ports);
163 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
164 struct flow_dissector *flow_dissector,
165 void *target_container)
167 struct flow_dissector_key_control *ctrl;
169 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
172 ctrl = skb_flow_dissector_target(flow_dissector,
173 FLOW_DISSECTOR_KEY_ENC_CONTROL,
175 ctrl->addr_type = type;
179 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
180 struct flow_dissector *flow_dissector,
181 void *target_container)
183 struct ip_tunnel_info *info;
184 struct ip_tunnel_key *key;
186 /* A quick check to see if there might be something to do. */
187 if (!dissector_uses_key(flow_dissector,
188 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
189 !dissector_uses_key(flow_dissector,
190 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
191 !dissector_uses_key(flow_dissector,
192 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
193 !dissector_uses_key(flow_dissector,
194 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
195 !dissector_uses_key(flow_dissector,
196 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
197 !dissector_uses_key(flow_dissector,
198 FLOW_DISSECTOR_KEY_ENC_IP) &&
199 !dissector_uses_key(flow_dissector,
200 FLOW_DISSECTOR_KEY_ENC_OPTS))
203 info = skb_tunnel_info(skb);
209 switch (ip_tunnel_info_af(info)) {
211 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
214 if (dissector_uses_key(flow_dissector,
215 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
216 struct flow_dissector_key_ipv4_addrs *ipv4;
218 ipv4 = skb_flow_dissector_target(flow_dissector,
219 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
221 ipv4->src = key->u.ipv4.src;
222 ipv4->dst = key->u.ipv4.dst;
226 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
229 if (dissector_uses_key(flow_dissector,
230 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
231 struct flow_dissector_key_ipv6_addrs *ipv6;
233 ipv6 = skb_flow_dissector_target(flow_dissector,
234 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
236 ipv6->src = key->u.ipv6.src;
237 ipv6->dst = key->u.ipv6.dst;
242 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
243 struct flow_dissector_key_keyid *keyid;
245 keyid = skb_flow_dissector_target(flow_dissector,
246 FLOW_DISSECTOR_KEY_ENC_KEYID,
248 keyid->keyid = tunnel_id_to_key32(key->tun_id);
251 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
252 struct flow_dissector_key_ports *tp;
254 tp = skb_flow_dissector_target(flow_dissector,
255 FLOW_DISSECTOR_KEY_ENC_PORTS,
257 tp->src = key->tp_src;
258 tp->dst = key->tp_dst;
261 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
262 struct flow_dissector_key_ip *ip;
264 ip = skb_flow_dissector_target(flow_dissector,
265 FLOW_DISSECTOR_KEY_ENC_IP,
271 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
272 struct flow_dissector_key_enc_opts *enc_opt;
274 enc_opt = skb_flow_dissector_target(flow_dissector,
275 FLOW_DISSECTOR_KEY_ENC_OPTS,
278 if (info->options_len) {
279 enc_opt->len = info->options_len;
280 ip_tunnel_info_opts_get(enc_opt->data, info);
281 enc_opt->dst_opt_type = info->key.tun_flags &
282 TUNNEL_OPTIONS_PRESENT;
286 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
288 static enum flow_dissect_ret
289 __skb_flow_dissect_mpls(const struct sk_buff *skb,
290 struct flow_dissector *flow_dissector,
291 void *target_container, void *data, int nhoff, int hlen)
293 struct flow_dissector_key_keyid *key_keyid;
294 struct mpls_label *hdr, _hdr[2];
297 if (!dissector_uses_key(flow_dissector,
298 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
299 !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
300 return FLOW_DISSECT_RET_OUT_GOOD;
302 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
305 return FLOW_DISSECT_RET_OUT_BAD;
307 entry = ntohl(hdr[0].entry);
308 label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
310 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
311 struct flow_dissector_key_mpls *key_mpls;
313 key_mpls = skb_flow_dissector_target(flow_dissector,
314 FLOW_DISSECTOR_KEY_MPLS,
316 key_mpls->mpls_label = label;
317 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
318 >> MPLS_LS_TTL_SHIFT;
319 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
321 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
325 if (label == MPLS_LABEL_ENTROPY) {
326 key_keyid = skb_flow_dissector_target(flow_dissector,
327 FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
329 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
331 return FLOW_DISSECT_RET_OUT_GOOD;
334 static enum flow_dissect_ret
335 __skb_flow_dissect_arp(const struct sk_buff *skb,
336 struct flow_dissector *flow_dissector,
337 void *target_container, void *data, int nhoff, int hlen)
339 struct flow_dissector_key_arp *key_arp;
341 unsigned char ar_sha[ETH_ALEN];
342 unsigned char ar_sip[4];
343 unsigned char ar_tha[ETH_ALEN];
344 unsigned char ar_tip[4];
345 } *arp_eth, _arp_eth;
346 const struct arphdr *arp;
349 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
350 return FLOW_DISSECT_RET_OUT_GOOD;
352 arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
355 return FLOW_DISSECT_RET_OUT_BAD;
357 if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
358 arp->ar_pro != htons(ETH_P_IP) ||
359 arp->ar_hln != ETH_ALEN ||
361 (arp->ar_op != htons(ARPOP_REPLY) &&
362 arp->ar_op != htons(ARPOP_REQUEST)))
363 return FLOW_DISSECT_RET_OUT_BAD;
365 arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
366 sizeof(_arp_eth), data,
369 return FLOW_DISSECT_RET_OUT_BAD;
371 key_arp = skb_flow_dissector_target(flow_dissector,
372 FLOW_DISSECTOR_KEY_ARP,
375 memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
376 memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
378 /* Only store the lower byte of the opcode;
379 * this covers ARPOP_REPLY and ARPOP_REQUEST.
381 key_arp->op = ntohs(arp->ar_op) & 0xff;
383 ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
384 ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
386 return FLOW_DISSECT_RET_OUT_GOOD;
389 static enum flow_dissect_ret
390 __skb_flow_dissect_gre(const struct sk_buff *skb,
391 struct flow_dissector_key_control *key_control,
392 struct flow_dissector *flow_dissector,
393 void *target_container, void *data,
394 __be16 *p_proto, int *p_nhoff, int *p_hlen,
397 struct flow_dissector_key_keyid *key_keyid;
398 struct gre_base_hdr *hdr, _hdr;
402 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
403 data, *p_hlen, &_hdr);
405 return FLOW_DISSECT_RET_OUT_BAD;
407 /* Only look inside GRE without routing */
408 if (hdr->flags & GRE_ROUTING)
409 return FLOW_DISSECT_RET_OUT_GOOD;
411 /* Only look inside GRE for version 0 and 1 */
412 gre_ver = ntohs(hdr->flags & GRE_VERSION);
414 return FLOW_DISSECT_RET_OUT_GOOD;
416 *p_proto = hdr->protocol;
418 /* Version1 must be PPTP, and check the flags */
419 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
420 return FLOW_DISSECT_RET_OUT_GOOD;
423 offset += sizeof(struct gre_base_hdr);
425 if (hdr->flags & GRE_CSUM)
426 offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
427 FIELD_SIZEOF(struct gre_full_hdr, reserved1);
429 if (hdr->flags & GRE_KEY) {
433 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
435 data, *p_hlen, &_keyid);
437 return FLOW_DISSECT_RET_OUT_BAD;
439 if (dissector_uses_key(flow_dissector,
440 FLOW_DISSECTOR_KEY_GRE_KEYID)) {
441 key_keyid = skb_flow_dissector_target(flow_dissector,
442 FLOW_DISSECTOR_KEY_GRE_KEYID,
445 key_keyid->keyid = *keyid;
447 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
449 offset += FIELD_SIZEOF(struct gre_full_hdr, key);
452 if (hdr->flags & GRE_SEQ)
453 offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
456 if (*p_proto == htons(ETH_P_TEB)) {
457 const struct ethhdr *eth;
460 eth = __skb_header_pointer(skb, *p_nhoff + offset,
462 data, *p_hlen, &_eth);
464 return FLOW_DISSECT_RET_OUT_BAD;
465 *p_proto = eth->h_proto;
466 offset += sizeof(*eth);
468 /* Cap headers that we access via pointers at the
469 * end of the Ethernet header as our maximum alignment
470 * at that point is only 2 bytes.
473 *p_hlen = *p_nhoff + offset;
475 } else { /* version 1, must be PPTP */
476 u8 _ppp_hdr[PPP_HDRLEN];
479 if (hdr->flags & GRE_ACK)
480 offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
482 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
484 data, *p_hlen, _ppp_hdr);
486 return FLOW_DISSECT_RET_OUT_BAD;
488 switch (PPP_PROTOCOL(ppp_hdr)) {
490 *p_proto = htons(ETH_P_IP);
493 *p_proto = htons(ETH_P_IPV6);
496 /* Could probably catch some more like MPLS */
500 offset += PPP_HDRLEN;
504 key_control->flags |= FLOW_DIS_ENCAPSULATION;
505 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
506 return FLOW_DISSECT_RET_OUT_GOOD;
508 return FLOW_DISSECT_RET_PROTO_AGAIN;
512 * __skb_flow_dissect_batadv() - dissect batman-adv header
513 * @skb: sk_buff to with the batman-adv header
514 * @key_control: flow dissectors control key
515 * @data: raw buffer pointer to the packet, if NULL use skb->data
516 * @p_proto: pointer used to update the protocol to process next
517 * @p_nhoff: pointer used to update inner network header offset
518 * @hlen: packet header length
519 * @flags: any combination of FLOW_DISSECTOR_F_*
521 * ETH_P_BATMAN packets are tried to be dissected. Only
522 * &struct batadv_unicast packets are actually processed because they contain an
523 * inner ethernet header and are usually followed by actual network header. This
524 * allows the flow dissector to continue processing the packet.
526 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
527 * FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
528 * otherwise FLOW_DISSECT_RET_OUT_BAD
530 static enum flow_dissect_ret
531 __skb_flow_dissect_batadv(const struct sk_buff *skb,
532 struct flow_dissector_key_control *key_control,
533 void *data, __be16 *p_proto, int *p_nhoff, int hlen,
537 struct batadv_unicast_packet batadv_unicast;
541 hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
544 return FLOW_DISSECT_RET_OUT_BAD;
546 if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
547 return FLOW_DISSECT_RET_OUT_BAD;
549 if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
550 return FLOW_DISSECT_RET_OUT_BAD;
552 *p_proto = hdr->eth.h_proto;
553 *p_nhoff += sizeof(*hdr);
555 key_control->flags |= FLOW_DIS_ENCAPSULATION;
556 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
557 return FLOW_DISSECT_RET_OUT_GOOD;
559 return FLOW_DISSECT_RET_PROTO_AGAIN;
563 __skb_flow_dissect_tcp(const struct sk_buff *skb,
564 struct flow_dissector *flow_dissector,
565 void *target_container, void *data, int thoff, int hlen)
567 struct flow_dissector_key_tcp *key_tcp;
568 struct tcphdr *th, _th;
570 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
573 th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
577 if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
580 key_tcp = skb_flow_dissector_target(flow_dissector,
581 FLOW_DISSECTOR_KEY_TCP,
583 key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
587 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
588 struct flow_dissector *flow_dissector,
589 void *target_container, void *data, const struct iphdr *iph)
591 struct flow_dissector_key_ip *key_ip;
593 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
596 key_ip = skb_flow_dissector_target(flow_dissector,
597 FLOW_DISSECTOR_KEY_IP,
599 key_ip->tos = iph->tos;
600 key_ip->ttl = iph->ttl;
604 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
605 struct flow_dissector *flow_dissector,
606 void *target_container, void *data, const struct ipv6hdr *iph)
608 struct flow_dissector_key_ip *key_ip;
610 if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
613 key_ip = skb_flow_dissector_target(flow_dissector,
614 FLOW_DISSECTOR_KEY_IP,
616 key_ip->tos = ipv6_get_dsfield(iph);
617 key_ip->ttl = iph->hop_limit;
620 /* Maximum number of protocol headers that can be parsed in
623 #define MAX_FLOW_DISSECT_HDRS 15
625 static bool skb_flow_dissect_allowed(int *num_hdrs)
629 return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
632 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
633 struct flow_dissector *flow_dissector,
634 void *target_container)
636 struct flow_dissector_key_control *key_control;
637 struct flow_dissector_key_basic *key_basic;
638 struct flow_dissector_key_addrs *key_addrs;
639 struct flow_dissector_key_ports *key_ports;
641 key_control = skb_flow_dissector_target(flow_dissector,
642 FLOW_DISSECTOR_KEY_CONTROL,
644 key_control->thoff = flow_keys->thoff;
645 if (flow_keys->is_frag)
646 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
647 if (flow_keys->is_first_frag)
648 key_control->flags |= FLOW_DIS_FIRST_FRAG;
649 if (flow_keys->is_encap)
650 key_control->flags |= FLOW_DIS_ENCAPSULATION;
652 key_basic = skb_flow_dissector_target(flow_dissector,
653 FLOW_DISSECTOR_KEY_BASIC,
655 key_basic->n_proto = flow_keys->n_proto;
656 key_basic->ip_proto = flow_keys->ip_proto;
658 if (flow_keys->addr_proto == ETH_P_IP &&
659 dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
660 key_addrs = skb_flow_dissector_target(flow_dissector,
661 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
663 key_addrs->v4addrs.src = flow_keys->ipv4_src;
664 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
665 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
666 } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
667 dissector_uses_key(flow_dissector,
668 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
669 key_addrs = skb_flow_dissector_target(flow_dissector,
670 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
672 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
673 sizeof(key_addrs->v6addrs));
674 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
677 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
678 key_ports = skb_flow_dissector_target(flow_dissector,
679 FLOW_DISSECTOR_KEY_PORTS,
681 key_ports->src = flow_keys->sport;
682 key_ports->dst = flow_keys->dport;
687 * __skb_flow_dissect - extract the flow_keys struct and return it
688 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
689 * @flow_dissector: list of keys to dissect
690 * @target_container: target structure to put dissected values into
691 * @data: raw buffer pointer to the packet, if NULL use skb->data
692 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
693 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
694 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
696 * The function will try to retrieve individual keys into target specified
697 * by flow_dissector from either the skbuff or a raw buffer specified by the
700 * Caller must take care of zeroing target container memory.
702 bool __skb_flow_dissect(const struct sk_buff *skb,
703 struct flow_dissector *flow_dissector,
704 void *target_container,
705 void *data, __be16 proto, int nhoff, int hlen,
708 struct flow_dissector_key_control *key_control;
709 struct flow_dissector_key_basic *key_basic;
710 struct flow_dissector_key_addrs *key_addrs;
711 struct flow_dissector_key_ports *key_ports;
712 struct flow_dissector_key_icmp *key_icmp;
713 struct flow_dissector_key_tags *key_tags;
714 struct flow_dissector_key_vlan *key_vlan;
715 enum flow_dissect_ret fdret;
716 enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
717 struct bpf_prog *attached = NULL;
724 proto = skb_vlan_tag_present(skb) ?
725 skb->vlan_proto : skb->protocol;
726 nhoff = skb_network_offset(skb);
727 hlen = skb_headlen(skb);
728 #if IS_ENABLED(CONFIG_NET_DSA)
729 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
730 const struct dsa_device_ops *ops;
733 ops = skb->dev->dsa_ptr->tag_ops;
734 if (ops->flow_dissect &&
735 !ops->flow_dissect(skb, &proto, &offset)) {
743 /* It is ensured by skb_flow_dissector_init() that control key will
746 key_control = skb_flow_dissector_target(flow_dissector,
747 FLOW_DISSECTOR_KEY_CONTROL,
750 /* It is ensured by skb_flow_dissector_init() that basic key will
753 key_basic = skb_flow_dissector_target(flow_dissector,
754 FLOW_DISSECTOR_KEY_BASIC,
760 attached = rcu_dereference(dev_net(skb->dev)->flow_dissector_prog);
762 attached = rcu_dereference(sock_net(skb->sk)->flow_dissector_prog);
767 /* Note that even though the const qualifier is discarded
768 * throughout the execution of the BPF program, all changes(the
769 * control block) are reverted after the BPF program returns.
770 * Therefore, __skb_flow_dissect does not alter the skb.
772 struct bpf_flow_keys flow_keys = {};
773 struct bpf_skb_data_end cb_saved;
774 struct bpf_skb_data_end *cb;
777 cb = (struct bpf_skb_data_end *)skb->cb;
779 /* Save Control Block */
780 memcpy(&cb_saved, cb, sizeof(cb_saved));
781 memset(cb, 0, sizeof(cb_saved));
783 /* Pass parameters to the BPF program */
784 cb->qdisc_cb.flow_keys = &flow_keys;
785 flow_keys.nhoff = nhoff;
787 bpf_compute_data_pointers((struct sk_buff *)skb);
788 result = BPF_PROG_RUN(attached, skb);
791 memcpy(cb, &cb_saved, sizeof(cb_saved));
793 __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
795 key_control->thoff = min_t(u16, key_control->thoff, skb->len);
797 return result == BPF_OK;
801 if (dissector_uses_key(flow_dissector,
802 FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
803 struct ethhdr *eth = eth_hdr(skb);
804 struct flow_dissector_key_eth_addrs *key_eth_addrs;
806 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
807 FLOW_DISSECTOR_KEY_ETH_ADDRS,
809 memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
813 fdret = FLOW_DISSECT_RET_CONTINUE;
816 case htons(ETH_P_IP): {
817 const struct iphdr *iph;
820 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
821 if (!iph || iph->ihl < 5) {
822 fdret = FLOW_DISSECT_RET_OUT_BAD;
826 nhoff += iph->ihl * 4;
828 ip_proto = iph->protocol;
830 if (dissector_uses_key(flow_dissector,
831 FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
832 key_addrs = skb_flow_dissector_target(flow_dissector,
833 FLOW_DISSECTOR_KEY_IPV4_ADDRS,
836 memcpy(&key_addrs->v4addrs, &iph->saddr,
837 sizeof(key_addrs->v4addrs));
838 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
841 if (ip_is_fragment(iph)) {
842 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
844 if (iph->frag_off & htons(IP_OFFSET)) {
845 fdret = FLOW_DISSECT_RET_OUT_GOOD;
848 key_control->flags |= FLOW_DIS_FIRST_FRAG;
850 FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
851 fdret = FLOW_DISSECT_RET_OUT_GOOD;
857 __skb_flow_dissect_ipv4(skb, flow_dissector,
858 target_container, data, iph);
860 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
861 fdret = FLOW_DISSECT_RET_OUT_GOOD;
867 case htons(ETH_P_IPV6): {
868 const struct ipv6hdr *iph;
871 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
873 fdret = FLOW_DISSECT_RET_OUT_BAD;
877 ip_proto = iph->nexthdr;
878 nhoff += sizeof(struct ipv6hdr);
880 if (dissector_uses_key(flow_dissector,
881 FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
882 key_addrs = skb_flow_dissector_target(flow_dissector,
883 FLOW_DISSECTOR_KEY_IPV6_ADDRS,
886 memcpy(&key_addrs->v6addrs, &iph->saddr,
887 sizeof(key_addrs->v6addrs));
888 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
891 if ((dissector_uses_key(flow_dissector,
892 FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
893 (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
894 ip6_flowlabel(iph)) {
895 __be32 flow_label = ip6_flowlabel(iph);
897 if (dissector_uses_key(flow_dissector,
898 FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
899 key_tags = skb_flow_dissector_target(flow_dissector,
900 FLOW_DISSECTOR_KEY_FLOW_LABEL,
902 key_tags->flow_label = ntohl(flow_label);
904 if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
905 fdret = FLOW_DISSECT_RET_OUT_GOOD;
910 __skb_flow_dissect_ipv6(skb, flow_dissector,
911 target_container, data, iph);
913 if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
914 fdret = FLOW_DISSECT_RET_OUT_GOOD;
918 case htons(ETH_P_8021AD):
919 case htons(ETH_P_8021Q): {
920 const struct vlan_hdr *vlan = NULL;
921 struct vlan_hdr _vlan;
922 __be16 saved_vlan_tpid = proto;
924 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
925 skb && skb_vlan_tag_present(skb)) {
926 proto = skb->protocol;
928 vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
931 fdret = FLOW_DISSECT_RET_OUT_BAD;
935 proto = vlan->h_vlan_encapsulated_proto;
936 nhoff += sizeof(*vlan);
939 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
940 dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
941 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
942 dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
944 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
948 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
949 key_vlan = skb_flow_dissector_target(flow_dissector,
954 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
955 key_vlan->vlan_priority =
956 (skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
958 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
960 key_vlan->vlan_priority =
961 (ntohs(vlan->h_vlan_TCI) &
962 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
964 key_vlan->vlan_tpid = saved_vlan_tpid;
967 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
970 case htons(ETH_P_PPP_SES): {
972 struct pppoe_hdr hdr;
975 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
977 fdret = FLOW_DISSECT_RET_OUT_BAD;
982 nhoff += PPPOE_SES_HLEN;
985 proto = htons(ETH_P_IP);
986 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
988 case htons(PPP_IPV6):
989 proto = htons(ETH_P_IPV6);
990 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
993 fdret = FLOW_DISSECT_RET_OUT_BAD;
998 case htons(ETH_P_TIPC): {
999 struct tipc_basic_hdr *hdr, _hdr;
1001 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1004 fdret = FLOW_DISSECT_RET_OUT_BAD;
1008 if (dissector_uses_key(flow_dissector,
1009 FLOW_DISSECTOR_KEY_TIPC)) {
1010 key_addrs = skb_flow_dissector_target(flow_dissector,
1011 FLOW_DISSECTOR_KEY_TIPC,
1013 key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1014 key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1016 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1020 case htons(ETH_P_MPLS_UC):
1021 case htons(ETH_P_MPLS_MC):
1022 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1023 target_container, data,
1026 case htons(ETH_P_FCOE):
1027 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1028 fdret = FLOW_DISSECT_RET_OUT_BAD;
1032 nhoff += FCOE_HEADER_LEN;
1033 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1036 case htons(ETH_P_ARP):
1037 case htons(ETH_P_RARP):
1038 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1039 target_container, data,
1043 case htons(ETH_P_BATMAN):
1044 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1045 &proto, &nhoff, hlen, flags);
1049 fdret = FLOW_DISSECT_RET_OUT_BAD;
1053 /* Process result of proto processing */
1055 case FLOW_DISSECT_RET_OUT_GOOD:
1057 case FLOW_DISSECT_RET_PROTO_AGAIN:
1058 if (skb_flow_dissect_allowed(&num_hdrs))
1061 case FLOW_DISSECT_RET_CONTINUE:
1062 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1064 case FLOW_DISSECT_RET_OUT_BAD:
1070 fdret = FLOW_DISSECT_RET_CONTINUE;
1074 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1075 target_container, data,
1076 &proto, &nhoff, &hlen, flags);
1080 case NEXTHDR_ROUTING:
1081 case NEXTHDR_DEST: {
1082 u8 _opthdr[2], *opthdr;
1084 if (proto != htons(ETH_P_IPV6))
1087 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1088 data, hlen, &_opthdr);
1090 fdret = FLOW_DISSECT_RET_OUT_BAD;
1094 ip_proto = opthdr[0];
1095 nhoff += (opthdr[1] + 1) << 3;
1097 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1100 case NEXTHDR_FRAGMENT: {
1101 struct frag_hdr _fh, *fh;
1103 if (proto != htons(ETH_P_IPV6))
1106 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1110 fdret = FLOW_DISSECT_RET_OUT_BAD;
1114 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1116 nhoff += sizeof(_fh);
1117 ip_proto = fh->nexthdr;
1119 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1120 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1121 if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1122 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1127 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1131 proto = htons(ETH_P_IP);
1133 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1134 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1135 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1139 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1143 proto = htons(ETH_P_IPV6);
1145 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1146 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1147 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1151 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1156 proto = htons(ETH_P_MPLS_UC);
1157 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1161 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1169 if (dissector_uses_key(flow_dissector,
1170 FLOW_DISSECTOR_KEY_PORTS)) {
1171 key_ports = skb_flow_dissector_target(flow_dissector,
1172 FLOW_DISSECTOR_KEY_PORTS,
1174 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1178 if (dissector_uses_key(flow_dissector,
1179 FLOW_DISSECTOR_KEY_ICMP)) {
1180 key_icmp = skb_flow_dissector_target(flow_dissector,
1181 FLOW_DISSECTOR_KEY_ICMP,
1183 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1186 /* Process result of IP proto processing */
1188 case FLOW_DISSECT_RET_PROTO_AGAIN:
1189 if (skb_flow_dissect_allowed(&num_hdrs))
1192 case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1193 if (skb_flow_dissect_allowed(&num_hdrs))
1194 goto ip_proto_again;
1196 case FLOW_DISSECT_RET_OUT_GOOD:
1197 case FLOW_DISSECT_RET_CONTINUE:
1199 case FLOW_DISSECT_RET_OUT_BAD:
1208 key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1209 key_basic->n_proto = proto;
1210 key_basic->ip_proto = ip_proto;
1218 EXPORT_SYMBOL(__skb_flow_dissect);
1220 static u32 hashrnd __read_mostly;
1221 static __always_inline void __flow_hash_secret_init(void)
1223 net_get_random_once(&hashrnd, sizeof(hashrnd));
1226 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1229 return jhash2(words, length, keyval);
1232 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1234 const void *p = flow;
1236 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1237 return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1240 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1242 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1243 BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1244 BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1245 sizeof(*flow) - sizeof(flow->addrs));
1247 switch (flow->control.addr_type) {
1248 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1249 diff -= sizeof(flow->addrs.v4addrs);
1251 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1252 diff -= sizeof(flow->addrs.v6addrs);
1254 case FLOW_DISSECTOR_KEY_TIPC:
1255 diff -= sizeof(flow->addrs.tipckey);
1258 return (sizeof(*flow) - diff) / sizeof(u32);
1261 __be32 flow_get_u32_src(const struct flow_keys *flow)
1263 switch (flow->control.addr_type) {
1264 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1265 return flow->addrs.v4addrs.src;
1266 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1267 return (__force __be32)ipv6_addr_hash(
1268 &flow->addrs.v6addrs.src);
1269 case FLOW_DISSECTOR_KEY_TIPC:
1270 return flow->addrs.tipckey.key;
1275 EXPORT_SYMBOL(flow_get_u32_src);
1277 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1279 switch (flow->control.addr_type) {
1280 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1281 return flow->addrs.v4addrs.dst;
1282 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1283 return (__force __be32)ipv6_addr_hash(
1284 &flow->addrs.v6addrs.dst);
1289 EXPORT_SYMBOL(flow_get_u32_dst);
1291 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1295 switch (keys->control.addr_type) {
1296 case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1297 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1298 (__force u32)keys->addrs.v4addrs.src;
1299 if ((addr_diff < 0) ||
1301 ((__force u16)keys->ports.dst <
1302 (__force u16)keys->ports.src))) {
1303 swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1304 swap(keys->ports.src, keys->ports.dst);
1307 case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1308 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1309 &keys->addrs.v6addrs.src,
1310 sizeof(keys->addrs.v6addrs.dst));
1311 if ((addr_diff < 0) ||
1313 ((__force u16)keys->ports.dst <
1314 (__force u16)keys->ports.src))) {
1315 for (i = 0; i < 4; i++)
1316 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1317 keys->addrs.v6addrs.dst.s6_addr32[i]);
1318 swap(keys->ports.src, keys->ports.dst);
1324 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1328 __flow_hash_consistentify(keys);
1330 hash = __flow_hash_words(flow_keys_hash_start(keys),
1331 flow_keys_hash_length(keys), keyval);
1338 u32 flow_hash_from_keys(struct flow_keys *keys)
1340 __flow_hash_secret_init();
1341 return __flow_hash_from_keys(keys, hashrnd);
1343 EXPORT_SYMBOL(flow_hash_from_keys);
1345 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1346 struct flow_keys *keys, u32 keyval)
1348 skb_flow_dissect_flow_keys(skb, keys,
1349 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1351 return __flow_hash_from_keys(keys, keyval);
1354 struct _flow_keys_digest_data {
1363 void make_flow_keys_digest(struct flow_keys_digest *digest,
1364 const struct flow_keys *flow)
1366 struct _flow_keys_digest_data *data =
1367 (struct _flow_keys_digest_data *)digest;
1369 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1371 memset(digest, 0, sizeof(*digest));
1373 data->n_proto = flow->basic.n_proto;
1374 data->ip_proto = flow->basic.ip_proto;
1375 data->ports = flow->ports.ports;
1376 data->src = flow->addrs.v4addrs.src;
1377 data->dst = flow->addrs.v4addrs.dst;
1379 EXPORT_SYMBOL(make_flow_keys_digest);
1381 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1383 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1385 struct flow_keys keys;
1387 __flow_hash_secret_init();
1389 memset(&keys, 0, sizeof(keys));
1390 __skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
1392 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1394 return __flow_hash_from_keys(&keys, hashrnd);
1396 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1399 * __skb_get_hash: calculate a flow hash
1400 * @skb: sk_buff to calculate flow hash from
1402 * This function calculates a flow hash based on src/dst addresses
1403 * and src/dst port numbers. Sets hash in skb to non-zero hash value
1404 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
1405 * if hash is a canonical 4-tuple hash over transport ports.
1407 void __skb_get_hash(struct sk_buff *skb)
1409 struct flow_keys keys;
1412 __flow_hash_secret_init();
1414 hash = ___skb_get_hash(skb, &keys, hashrnd);
1416 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1418 EXPORT_SYMBOL(__skb_get_hash);
1420 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1422 struct flow_keys keys;
1424 return ___skb_get_hash(skb, &keys, perturb);
1426 EXPORT_SYMBOL(skb_get_hash_perturb);
1428 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1429 const struct flow_keys_basic *keys, int hlen)
1431 u32 poff = keys->control.thoff;
1433 /* skip L4 headers for fragments after the first */
1434 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1435 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1438 switch (keys->basic.ip_proto) {
1440 /* access doff as u8 to avoid unaligned access */
1444 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1445 data, hlen, &_doff);
1449 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1453 case IPPROTO_UDPLITE:
1454 poff += sizeof(struct udphdr);
1456 /* For the rest, we do not really care about header
1457 * extensions at this point for now.
1460 poff += sizeof(struct icmphdr);
1462 case IPPROTO_ICMPV6:
1463 poff += sizeof(struct icmp6hdr);
1466 poff += sizeof(struct igmphdr);
1469 poff += sizeof(struct dccp_hdr);
1472 poff += sizeof(struct sctphdr);
1480 * skb_get_poff - get the offset to the payload
1481 * @skb: sk_buff to get the payload offset from
1483 * The function will get the offset to the payload as far as it could
1484 * be dissected. The main user is currently BPF, so that we can dynamically
1485 * truncate packets without needing to push actual payload to the user
1486 * space and can analyze headers only, instead.
1488 u32 skb_get_poff(const struct sk_buff *skb)
1490 struct flow_keys_basic keys;
1492 if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1495 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1498 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1500 memset(keys, 0, sizeof(*keys));
1502 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1503 sizeof(keys->addrs.v6addrs.src));
1504 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1505 sizeof(keys->addrs.v6addrs.dst));
1506 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1507 keys->ports.src = fl6->fl6_sport;
1508 keys->ports.dst = fl6->fl6_dport;
1509 keys->keyid.keyid = fl6->fl6_gre_key;
1510 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1511 keys->basic.ip_proto = fl6->flowi6_proto;
1513 return flow_hash_from_keys(keys);
1515 EXPORT_SYMBOL(__get_hash_from_flowi6);
1517 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1519 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1520 .offset = offsetof(struct flow_keys, control),
1523 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1524 .offset = offsetof(struct flow_keys, basic),
1527 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1528 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1531 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1532 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1535 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1536 .offset = offsetof(struct flow_keys, addrs.tipckey),
1539 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1540 .offset = offsetof(struct flow_keys, ports),
1543 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1544 .offset = offsetof(struct flow_keys, vlan),
1547 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1548 .offset = offsetof(struct flow_keys, tags),
1551 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1552 .offset = offsetof(struct flow_keys, keyid),
1556 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1558 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1559 .offset = offsetof(struct flow_keys, control),
1562 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1563 .offset = offsetof(struct flow_keys, basic),
1566 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1567 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1570 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1571 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1574 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1575 .offset = offsetof(struct flow_keys, ports),
1579 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1581 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1582 .offset = offsetof(struct flow_keys, control),
1585 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1586 .offset = offsetof(struct flow_keys, basic),
1590 struct flow_dissector flow_keys_dissector __read_mostly;
1591 EXPORT_SYMBOL(flow_keys_dissector);
1593 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1594 EXPORT_SYMBOL(flow_keys_basic_dissector);
1596 static int __init init_default_flow_dissectors(void)
1598 skb_flow_dissector_init(&flow_keys_dissector,
1599 flow_keys_dissector_keys,
1600 ARRAY_SIZE(flow_keys_dissector_keys));
1601 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1602 flow_keys_dissector_symmetric_keys,
1603 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1604 skb_flow_dissector_init(&flow_keys_basic_dissector,
1605 flow_keys_basic_dissector_keys,
1606 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1610 core_initcall(init_default_flow_dissectors);