Merge tag 'fixes-2023-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt...
[linux-block.git] / net / core / flow_dissector.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 #include <linux/kernel.h>
3 #include <linux/skbuff.h>
4 #include <linux/export.h>
5 #include <linux/ip.h>
6 #include <linux/ipv6.h>
7 #include <linux/if_vlan.h>
8 #include <linux/filter.h>
9 #include <net/dsa.h>
10 #include <net/dst_metadata.h>
11 #include <net/ip.h>
12 #include <net/ipv6.h>
13 #include <net/gre.h>
14 #include <net/pptp.h>
15 #include <net/tipc.h>
16 #include <linux/igmp.h>
17 #include <linux/icmp.h>
18 #include <linux/sctp.h>
19 #include <linux/dccp.h>
20 #include <linux/if_tunnel.h>
21 #include <linux/if_pppox.h>
22 #include <linux/ppp_defs.h>
23 #include <linux/stddef.h>
24 #include <linux/if_ether.h>
25 #include <linux/if_hsr.h>
26 #include <linux/mpls.h>
27 #include <linux/tcp.h>
28 #include <linux/ptp_classify.h>
29 #include <net/flow_dissector.h>
30 #include <scsi/fc/fc_fcoe.h>
31 #include <uapi/linux/batadv_packet.h>
32 #include <linux/bpf.h>
33 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
34 #include <net/netfilter/nf_conntrack_core.h>
35 #include <net/netfilter/nf_conntrack_labels.h>
36 #endif
37 #include <linux/bpf-netns.h>
38
39 static void dissector_set_key(struct flow_dissector *flow_dissector,
40                               enum flow_dissector_key_id key_id)
41 {
42         flow_dissector->used_keys |= (1 << key_id);
43 }
44
45 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
46                              const struct flow_dissector_key *key,
47                              unsigned int key_count)
48 {
49         unsigned int i;
50
51         memset(flow_dissector, 0, sizeof(*flow_dissector));
52
53         for (i = 0; i < key_count; i++, key++) {
54                 /* User should make sure that every key target offset is within
55                  * boundaries of unsigned short.
56                  */
57                 BUG_ON(key->offset > USHRT_MAX);
58                 BUG_ON(dissector_uses_key(flow_dissector,
59                                           key->key_id));
60
61                 dissector_set_key(flow_dissector, key->key_id);
62                 flow_dissector->offset[key->key_id] = key->offset;
63         }
64
65         /* Ensure that the dissector always includes control and basic key.
66          * That way we are able to avoid handling lack of these in fast path.
67          */
68         BUG_ON(!dissector_uses_key(flow_dissector,
69                                    FLOW_DISSECTOR_KEY_CONTROL));
70         BUG_ON(!dissector_uses_key(flow_dissector,
71                                    FLOW_DISSECTOR_KEY_BASIC));
72 }
73 EXPORT_SYMBOL(skb_flow_dissector_init);
74
75 #ifdef CONFIG_BPF_SYSCALL
76 int flow_dissector_bpf_prog_attach_check(struct net *net,
77                                          struct bpf_prog *prog)
78 {
79         enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
80
81         if (net == &init_net) {
82                 /* BPF flow dissector in the root namespace overrides
83                  * any per-net-namespace one. When attaching to root,
84                  * make sure we don't have any BPF program attached
85                  * to the non-root namespaces.
86                  */
87                 struct net *ns;
88
89                 for_each_net(ns) {
90                         if (ns == &init_net)
91                                 continue;
92                         if (rcu_access_pointer(ns->bpf.run_array[type]))
93                                 return -EEXIST;
94                 }
95         } else {
96                 /* Make sure root flow dissector is not attached
97                  * when attaching to the non-root namespace.
98                  */
99                 if (rcu_access_pointer(init_net.bpf.run_array[type]))
100                         return -EEXIST;
101         }
102
103         return 0;
104 }
105 #endif /* CONFIG_BPF_SYSCALL */
106
107 /**
108  * __skb_flow_get_ports - extract the upper layer ports and return them
109  * @skb: sk_buff to extract the ports from
110  * @thoff: transport header offset
111  * @ip_proto: protocol for which to get port offset
112  * @data: raw buffer pointer to the packet, if NULL use skb->data
113  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
114  *
115  * The function will try to retrieve the ports at offset thoff + poff where poff
116  * is the protocol port offset returned from proto_ports_offset
117  */
118 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
119                             const void *data, int hlen)
120 {
121         int poff = proto_ports_offset(ip_proto);
122
123         if (!data) {
124                 data = skb->data;
125                 hlen = skb_headlen(skb);
126         }
127
128         if (poff >= 0) {
129                 __be32 *ports, _ports;
130
131                 ports = __skb_header_pointer(skb, thoff + poff,
132                                              sizeof(_ports), data, hlen, &_ports);
133                 if (ports)
134                         return *ports;
135         }
136
137         return 0;
138 }
139 EXPORT_SYMBOL(__skb_flow_get_ports);
140
141 static bool icmp_has_id(u8 type)
142 {
143         switch (type) {
144         case ICMP_ECHO:
145         case ICMP_ECHOREPLY:
146         case ICMP_TIMESTAMP:
147         case ICMP_TIMESTAMPREPLY:
148         case ICMPV6_ECHO_REQUEST:
149         case ICMPV6_ECHO_REPLY:
150                 return true;
151         }
152
153         return false;
154 }
155
156 /**
157  * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
158  * @skb: sk_buff to extract from
159  * @key_icmp: struct flow_dissector_key_icmp to fill
160  * @data: raw buffer pointer to the packet
161  * @thoff: offset to extract at
162  * @hlen: packet header length
163  */
164 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
165                            struct flow_dissector_key_icmp *key_icmp,
166                            const void *data, int thoff, int hlen)
167 {
168         struct icmphdr *ih, _ih;
169
170         ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
171         if (!ih)
172                 return;
173
174         key_icmp->type = ih->type;
175         key_icmp->code = ih->code;
176
177         /* As we use 0 to signal that the Id field is not present,
178          * avoid confusion with packets without such field
179          */
180         if (icmp_has_id(ih->type))
181                 key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1;
182         else
183                 key_icmp->id = 0;
184 }
185 EXPORT_SYMBOL(skb_flow_get_icmp_tci);
186
187 /* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
188  * using skb_flow_get_icmp_tci().
189  */
190 static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
191                                     struct flow_dissector *flow_dissector,
192                                     void *target_container, const void *data,
193                                     int thoff, int hlen)
194 {
195         struct flow_dissector_key_icmp *key_icmp;
196
197         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
198                 return;
199
200         key_icmp = skb_flow_dissector_target(flow_dissector,
201                                              FLOW_DISSECTOR_KEY_ICMP,
202                                              target_container);
203
204         skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
205 }
206
207 static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb,
208                                       struct flow_dissector *flow_dissector,
209                                       void *target_container, const void *data,
210                                       int nhoff, int hlen)
211 {
212         struct flow_dissector_key_l2tpv3 *key_l2tpv3;
213         struct {
214                 __be32 session_id;
215         } *hdr, _hdr;
216
217         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3))
218                 return;
219
220         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
221         if (!hdr)
222                 return;
223
224         key_l2tpv3 = skb_flow_dissector_target(flow_dissector,
225                                                FLOW_DISSECTOR_KEY_L2TPV3,
226                                                target_container);
227
228         key_l2tpv3->session_id = hdr->session_id;
229 }
230
231 void skb_flow_dissect_meta(const struct sk_buff *skb,
232                            struct flow_dissector *flow_dissector,
233                            void *target_container)
234 {
235         struct flow_dissector_key_meta *meta;
236
237         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
238                 return;
239
240         meta = skb_flow_dissector_target(flow_dissector,
241                                          FLOW_DISSECTOR_KEY_META,
242                                          target_container);
243         meta->ingress_ifindex = skb->skb_iif;
244 }
245 EXPORT_SYMBOL(skb_flow_dissect_meta);
246
247 static void
248 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
249                                    struct flow_dissector *flow_dissector,
250                                    void *target_container)
251 {
252         struct flow_dissector_key_control *ctrl;
253
254         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
255                 return;
256
257         ctrl = skb_flow_dissector_target(flow_dissector,
258                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
259                                          target_container);
260         ctrl->addr_type = type;
261 }
262
263 void
264 skb_flow_dissect_ct(const struct sk_buff *skb,
265                     struct flow_dissector *flow_dissector,
266                     void *target_container, u16 *ctinfo_map,
267                     size_t mapsize, bool post_ct, u16 zone)
268 {
269 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
270         struct flow_dissector_key_ct *key;
271         enum ip_conntrack_info ctinfo;
272         struct nf_conn_labels *cl;
273         struct nf_conn *ct;
274
275         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
276                 return;
277
278         ct = nf_ct_get(skb, &ctinfo);
279         if (!ct && !post_ct)
280                 return;
281
282         key = skb_flow_dissector_target(flow_dissector,
283                                         FLOW_DISSECTOR_KEY_CT,
284                                         target_container);
285
286         if (!ct) {
287                 key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED |
288                                 TCA_FLOWER_KEY_CT_FLAGS_INVALID;
289                 key->ct_zone = zone;
290                 return;
291         }
292
293         if (ctinfo < mapsize)
294                 key->ct_state = ctinfo_map[ctinfo];
295 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
296         key->ct_zone = ct->zone.id;
297 #endif
298 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
299         key->ct_mark = READ_ONCE(ct->mark);
300 #endif
301
302         cl = nf_ct_labels_find(ct);
303         if (cl)
304                 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
305 #endif /* CONFIG_NF_CONNTRACK */
306 }
307 EXPORT_SYMBOL(skb_flow_dissect_ct);
308
309 void
310 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
311                              struct flow_dissector *flow_dissector,
312                              void *target_container)
313 {
314         struct ip_tunnel_info *info;
315         struct ip_tunnel_key *key;
316
317         /* A quick check to see if there might be something to do. */
318         if (!dissector_uses_key(flow_dissector,
319                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
320             !dissector_uses_key(flow_dissector,
321                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
322             !dissector_uses_key(flow_dissector,
323                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
324             !dissector_uses_key(flow_dissector,
325                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
326             !dissector_uses_key(flow_dissector,
327                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
328             !dissector_uses_key(flow_dissector,
329                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
330             !dissector_uses_key(flow_dissector,
331                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
332                 return;
333
334         info = skb_tunnel_info(skb);
335         if (!info)
336                 return;
337
338         key = &info->key;
339
340         switch (ip_tunnel_info_af(info)) {
341         case AF_INET:
342                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
343                                                    flow_dissector,
344                                                    target_container);
345                 if (dissector_uses_key(flow_dissector,
346                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
347                         struct flow_dissector_key_ipv4_addrs *ipv4;
348
349                         ipv4 = skb_flow_dissector_target(flow_dissector,
350                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
351                                                          target_container);
352                         ipv4->src = key->u.ipv4.src;
353                         ipv4->dst = key->u.ipv4.dst;
354                 }
355                 break;
356         case AF_INET6:
357                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
358                                                    flow_dissector,
359                                                    target_container);
360                 if (dissector_uses_key(flow_dissector,
361                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
362                         struct flow_dissector_key_ipv6_addrs *ipv6;
363
364                         ipv6 = skb_flow_dissector_target(flow_dissector,
365                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
366                                                          target_container);
367                         ipv6->src = key->u.ipv6.src;
368                         ipv6->dst = key->u.ipv6.dst;
369                 }
370                 break;
371         }
372
373         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
374                 struct flow_dissector_key_keyid *keyid;
375
376                 keyid = skb_flow_dissector_target(flow_dissector,
377                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
378                                                   target_container);
379                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
380         }
381
382         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
383                 struct flow_dissector_key_ports *tp;
384
385                 tp = skb_flow_dissector_target(flow_dissector,
386                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
387                                                target_container);
388                 tp->src = key->tp_src;
389                 tp->dst = key->tp_dst;
390         }
391
392         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
393                 struct flow_dissector_key_ip *ip;
394
395                 ip = skb_flow_dissector_target(flow_dissector,
396                                                FLOW_DISSECTOR_KEY_ENC_IP,
397                                                target_container);
398                 ip->tos = key->tos;
399                 ip->ttl = key->ttl;
400         }
401
402         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
403                 struct flow_dissector_key_enc_opts *enc_opt;
404
405                 enc_opt = skb_flow_dissector_target(flow_dissector,
406                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
407                                                     target_container);
408
409                 if (info->options_len) {
410                         enc_opt->len = info->options_len;
411                         ip_tunnel_info_opts_get(enc_opt->data, info);
412                         enc_opt->dst_opt_type = info->key.tun_flags &
413                                                 TUNNEL_OPTIONS_PRESENT;
414                 }
415         }
416 }
417 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
418
419 void skb_flow_dissect_hash(const struct sk_buff *skb,
420                            struct flow_dissector *flow_dissector,
421                            void *target_container)
422 {
423         struct flow_dissector_key_hash *key;
424
425         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
426                 return;
427
428         key = skb_flow_dissector_target(flow_dissector,
429                                         FLOW_DISSECTOR_KEY_HASH,
430                                         target_container);
431
432         key->hash = skb_get_hash_raw(skb);
433 }
434 EXPORT_SYMBOL(skb_flow_dissect_hash);
435
436 static enum flow_dissect_ret
437 __skb_flow_dissect_mpls(const struct sk_buff *skb,
438                         struct flow_dissector *flow_dissector,
439                         void *target_container, const void *data, int nhoff,
440                         int hlen, int lse_index, bool *entropy_label)
441 {
442         struct mpls_label *hdr, _hdr;
443         u32 entry, label, bos;
444
445         if (!dissector_uses_key(flow_dissector,
446                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
447             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
448                 return FLOW_DISSECT_RET_OUT_GOOD;
449
450         if (lse_index >= FLOW_DIS_MPLS_MAX)
451                 return FLOW_DISSECT_RET_OUT_GOOD;
452
453         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
454                                    hlen, &_hdr);
455         if (!hdr)
456                 return FLOW_DISSECT_RET_OUT_BAD;
457
458         entry = ntohl(hdr->entry);
459         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
460         bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
461
462         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
463                 struct flow_dissector_key_mpls *key_mpls;
464                 struct flow_dissector_mpls_lse *lse;
465
466                 key_mpls = skb_flow_dissector_target(flow_dissector,
467                                                      FLOW_DISSECTOR_KEY_MPLS,
468                                                      target_container);
469                 lse = &key_mpls->ls[lse_index];
470
471                 lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
472                 lse->mpls_bos = bos;
473                 lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
474                 lse->mpls_label = label;
475                 dissector_set_mpls_lse(key_mpls, lse_index);
476         }
477
478         if (*entropy_label &&
479             dissector_uses_key(flow_dissector,
480                                FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
481                 struct flow_dissector_key_keyid *key_keyid;
482
483                 key_keyid = skb_flow_dissector_target(flow_dissector,
484                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
485                                                       target_container);
486                 key_keyid->keyid = cpu_to_be32(label);
487         }
488
489         *entropy_label = label == MPLS_LABEL_ENTROPY;
490
491         return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
492 }
493
494 static enum flow_dissect_ret
495 __skb_flow_dissect_arp(const struct sk_buff *skb,
496                        struct flow_dissector *flow_dissector,
497                        void *target_container, const void *data,
498                        int nhoff, int hlen)
499 {
500         struct flow_dissector_key_arp *key_arp;
501         struct {
502                 unsigned char ar_sha[ETH_ALEN];
503                 unsigned char ar_sip[4];
504                 unsigned char ar_tha[ETH_ALEN];
505                 unsigned char ar_tip[4];
506         } *arp_eth, _arp_eth;
507         const struct arphdr *arp;
508         struct arphdr _arp;
509
510         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
511                 return FLOW_DISSECT_RET_OUT_GOOD;
512
513         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
514                                    hlen, &_arp);
515         if (!arp)
516                 return FLOW_DISSECT_RET_OUT_BAD;
517
518         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
519             arp->ar_pro != htons(ETH_P_IP) ||
520             arp->ar_hln != ETH_ALEN ||
521             arp->ar_pln != 4 ||
522             (arp->ar_op != htons(ARPOP_REPLY) &&
523              arp->ar_op != htons(ARPOP_REQUEST)))
524                 return FLOW_DISSECT_RET_OUT_BAD;
525
526         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
527                                        sizeof(_arp_eth), data,
528                                        hlen, &_arp_eth);
529         if (!arp_eth)
530                 return FLOW_DISSECT_RET_OUT_BAD;
531
532         key_arp = skb_flow_dissector_target(flow_dissector,
533                                             FLOW_DISSECTOR_KEY_ARP,
534                                             target_container);
535
536         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
537         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
538
539         /* Only store the lower byte of the opcode;
540          * this covers ARPOP_REPLY and ARPOP_REQUEST.
541          */
542         key_arp->op = ntohs(arp->ar_op) & 0xff;
543
544         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
545         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
546
547         return FLOW_DISSECT_RET_OUT_GOOD;
548 }
549
550 static enum flow_dissect_ret
551 __skb_flow_dissect_gre(const struct sk_buff *skb,
552                        struct flow_dissector_key_control *key_control,
553                        struct flow_dissector *flow_dissector,
554                        void *target_container, const void *data,
555                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
556                        unsigned int flags)
557 {
558         struct flow_dissector_key_keyid *key_keyid;
559         struct gre_base_hdr *hdr, _hdr;
560         int offset = 0;
561         u16 gre_ver;
562
563         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
564                                    data, *p_hlen, &_hdr);
565         if (!hdr)
566                 return FLOW_DISSECT_RET_OUT_BAD;
567
568         /* Only look inside GRE without routing */
569         if (hdr->flags & GRE_ROUTING)
570                 return FLOW_DISSECT_RET_OUT_GOOD;
571
572         /* Only look inside GRE for version 0 and 1 */
573         gre_ver = ntohs(hdr->flags & GRE_VERSION);
574         if (gre_ver > 1)
575                 return FLOW_DISSECT_RET_OUT_GOOD;
576
577         *p_proto = hdr->protocol;
578         if (gre_ver) {
579                 /* Version1 must be PPTP, and check the flags */
580                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
581                         return FLOW_DISSECT_RET_OUT_GOOD;
582         }
583
584         offset += sizeof(struct gre_base_hdr);
585
586         if (hdr->flags & GRE_CSUM)
587                 offset += sizeof_field(struct gre_full_hdr, csum) +
588                           sizeof_field(struct gre_full_hdr, reserved1);
589
590         if (hdr->flags & GRE_KEY) {
591                 const __be32 *keyid;
592                 __be32 _keyid;
593
594                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
595                                              sizeof(_keyid),
596                                              data, *p_hlen, &_keyid);
597                 if (!keyid)
598                         return FLOW_DISSECT_RET_OUT_BAD;
599
600                 if (dissector_uses_key(flow_dissector,
601                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
602                         key_keyid = skb_flow_dissector_target(flow_dissector,
603                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
604                                                               target_container);
605                         if (gre_ver == 0)
606                                 key_keyid->keyid = *keyid;
607                         else
608                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
609                 }
610                 offset += sizeof_field(struct gre_full_hdr, key);
611         }
612
613         if (hdr->flags & GRE_SEQ)
614                 offset += sizeof_field(struct pptp_gre_header, seq);
615
616         if (gre_ver == 0) {
617                 if (*p_proto == htons(ETH_P_TEB)) {
618                         const struct ethhdr *eth;
619                         struct ethhdr _eth;
620
621                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
622                                                    sizeof(_eth),
623                                                    data, *p_hlen, &_eth);
624                         if (!eth)
625                                 return FLOW_DISSECT_RET_OUT_BAD;
626                         *p_proto = eth->h_proto;
627                         offset += sizeof(*eth);
628
629                         /* Cap headers that we access via pointers at the
630                          * end of the Ethernet header as our maximum alignment
631                          * at that point is only 2 bytes.
632                          */
633                         if (NET_IP_ALIGN)
634                                 *p_hlen = *p_nhoff + offset;
635                 }
636         } else { /* version 1, must be PPTP */
637                 u8 _ppp_hdr[PPP_HDRLEN];
638                 u8 *ppp_hdr;
639
640                 if (hdr->flags & GRE_ACK)
641                         offset += sizeof_field(struct pptp_gre_header, ack);
642
643                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
644                                                sizeof(_ppp_hdr),
645                                                data, *p_hlen, _ppp_hdr);
646                 if (!ppp_hdr)
647                         return FLOW_DISSECT_RET_OUT_BAD;
648
649                 switch (PPP_PROTOCOL(ppp_hdr)) {
650                 case PPP_IP:
651                         *p_proto = htons(ETH_P_IP);
652                         break;
653                 case PPP_IPV6:
654                         *p_proto = htons(ETH_P_IPV6);
655                         break;
656                 default:
657                         /* Could probably catch some more like MPLS */
658                         break;
659                 }
660
661                 offset += PPP_HDRLEN;
662         }
663
664         *p_nhoff += offset;
665         key_control->flags |= FLOW_DIS_ENCAPSULATION;
666         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
667                 return FLOW_DISSECT_RET_OUT_GOOD;
668
669         return FLOW_DISSECT_RET_PROTO_AGAIN;
670 }
671
672 /**
673  * __skb_flow_dissect_batadv() - dissect batman-adv header
674  * @skb: sk_buff to with the batman-adv header
675  * @key_control: flow dissectors control key
676  * @data: raw buffer pointer to the packet, if NULL use skb->data
677  * @p_proto: pointer used to update the protocol to process next
678  * @p_nhoff: pointer used to update inner network header offset
679  * @hlen: packet header length
680  * @flags: any combination of FLOW_DISSECTOR_F_*
681  *
682  * ETH_P_BATMAN packets are tried to be dissected. Only
683  * &struct batadv_unicast packets are actually processed because they contain an
684  * inner ethernet header and are usually followed by actual network header. This
685  * allows the flow dissector to continue processing the packet.
686  *
687  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
688  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
689  *  otherwise FLOW_DISSECT_RET_OUT_BAD
690  */
691 static enum flow_dissect_ret
692 __skb_flow_dissect_batadv(const struct sk_buff *skb,
693                           struct flow_dissector_key_control *key_control,
694                           const void *data, __be16 *p_proto, int *p_nhoff,
695                           int hlen, unsigned int flags)
696 {
697         struct {
698                 struct batadv_unicast_packet batadv_unicast;
699                 struct ethhdr eth;
700         } *hdr, _hdr;
701
702         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
703                                    &_hdr);
704         if (!hdr)
705                 return FLOW_DISSECT_RET_OUT_BAD;
706
707         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
708                 return FLOW_DISSECT_RET_OUT_BAD;
709
710         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
711                 return FLOW_DISSECT_RET_OUT_BAD;
712
713         *p_proto = hdr->eth.h_proto;
714         *p_nhoff += sizeof(*hdr);
715
716         key_control->flags |= FLOW_DIS_ENCAPSULATION;
717         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
718                 return FLOW_DISSECT_RET_OUT_GOOD;
719
720         return FLOW_DISSECT_RET_PROTO_AGAIN;
721 }
722
723 static void
724 __skb_flow_dissect_tcp(const struct sk_buff *skb,
725                        struct flow_dissector *flow_dissector,
726                        void *target_container, const void *data,
727                        int thoff, int hlen)
728 {
729         struct flow_dissector_key_tcp *key_tcp;
730         struct tcphdr *th, _th;
731
732         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
733                 return;
734
735         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
736         if (!th)
737                 return;
738
739         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
740                 return;
741
742         key_tcp = skb_flow_dissector_target(flow_dissector,
743                                             FLOW_DISSECTOR_KEY_TCP,
744                                             target_container);
745         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
746 }
747
748 static void
749 __skb_flow_dissect_ports(const struct sk_buff *skb,
750                          struct flow_dissector *flow_dissector,
751                          void *target_container, const void *data,
752                          int nhoff, u8 ip_proto, int hlen)
753 {
754         enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX;
755         struct flow_dissector_key_ports *key_ports;
756
757         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
758                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS;
759         else if (dissector_uses_key(flow_dissector,
760                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
761                 dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
762
763         if (dissector_ports == FLOW_DISSECTOR_KEY_MAX)
764                 return;
765
766         key_ports = skb_flow_dissector_target(flow_dissector,
767                                               dissector_ports,
768                                               target_container);
769         key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
770                                                 data, hlen);
771 }
772
773 static void
774 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
775                         struct flow_dissector *flow_dissector,
776                         void *target_container, const void *data,
777                         const struct iphdr *iph)
778 {
779         struct flow_dissector_key_ip *key_ip;
780
781         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
782                 return;
783
784         key_ip = skb_flow_dissector_target(flow_dissector,
785                                            FLOW_DISSECTOR_KEY_IP,
786                                            target_container);
787         key_ip->tos = iph->tos;
788         key_ip->ttl = iph->ttl;
789 }
790
791 static void
792 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
793                         struct flow_dissector *flow_dissector,
794                         void *target_container, const void *data,
795                         const struct ipv6hdr *iph)
796 {
797         struct flow_dissector_key_ip *key_ip;
798
799         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
800                 return;
801
802         key_ip = skb_flow_dissector_target(flow_dissector,
803                                            FLOW_DISSECTOR_KEY_IP,
804                                            target_container);
805         key_ip->tos = ipv6_get_dsfield(iph);
806         key_ip->ttl = iph->hop_limit;
807 }
808
809 /* Maximum number of protocol headers that can be parsed in
810  * __skb_flow_dissect
811  */
812 #define MAX_FLOW_DISSECT_HDRS   15
813
814 static bool skb_flow_dissect_allowed(int *num_hdrs)
815 {
816         ++*num_hdrs;
817
818         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
819 }
820
821 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
822                                      struct flow_dissector *flow_dissector,
823                                      void *target_container)
824 {
825         struct flow_dissector_key_ports *key_ports = NULL;
826         struct flow_dissector_key_control *key_control;
827         struct flow_dissector_key_basic *key_basic;
828         struct flow_dissector_key_addrs *key_addrs;
829         struct flow_dissector_key_tags *key_tags;
830
831         key_control = skb_flow_dissector_target(flow_dissector,
832                                                 FLOW_DISSECTOR_KEY_CONTROL,
833                                                 target_container);
834         key_control->thoff = flow_keys->thoff;
835         if (flow_keys->is_frag)
836                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
837         if (flow_keys->is_first_frag)
838                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
839         if (flow_keys->is_encap)
840                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
841
842         key_basic = skb_flow_dissector_target(flow_dissector,
843                                               FLOW_DISSECTOR_KEY_BASIC,
844                                               target_container);
845         key_basic->n_proto = flow_keys->n_proto;
846         key_basic->ip_proto = flow_keys->ip_proto;
847
848         if (flow_keys->addr_proto == ETH_P_IP &&
849             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
850                 key_addrs = skb_flow_dissector_target(flow_dissector,
851                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
852                                                       target_container);
853                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
854                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
855                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
856         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
857                    dissector_uses_key(flow_dissector,
858                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
859                 key_addrs = skb_flow_dissector_target(flow_dissector,
860                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
861                                                       target_container);
862                 memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src,
863                        sizeof(key_addrs->v6addrs.src));
864                 memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst,
865                        sizeof(key_addrs->v6addrs.dst));
866                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
867         }
868
869         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
870                 key_ports = skb_flow_dissector_target(flow_dissector,
871                                                       FLOW_DISSECTOR_KEY_PORTS,
872                                                       target_container);
873         else if (dissector_uses_key(flow_dissector,
874                                     FLOW_DISSECTOR_KEY_PORTS_RANGE))
875                 key_ports = skb_flow_dissector_target(flow_dissector,
876                                                       FLOW_DISSECTOR_KEY_PORTS_RANGE,
877                                                       target_container);
878
879         if (key_ports) {
880                 key_ports->src = flow_keys->sport;
881                 key_ports->dst = flow_keys->dport;
882         }
883
884         if (dissector_uses_key(flow_dissector,
885                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
886                 key_tags = skb_flow_dissector_target(flow_dissector,
887                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
888                                                      target_container);
889                 key_tags->flow_label = ntohl(flow_keys->flow_label);
890         }
891 }
892
893 u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
894                      __be16 proto, int nhoff, int hlen, unsigned int flags)
895 {
896         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
897         u32 result;
898
899         /* Pass parameters to the BPF program */
900         memset(flow_keys, 0, sizeof(*flow_keys));
901         flow_keys->n_proto = proto;
902         flow_keys->nhoff = nhoff;
903         flow_keys->thoff = flow_keys->nhoff;
904
905         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
906                      (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
907         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
908                      (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
909         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
910                      (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
911         flow_keys->flags = flags;
912
913         result = bpf_prog_run_pin_on_cpu(prog, ctx);
914
915         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
916         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
917                                    flow_keys->nhoff, hlen);
918
919         return result;
920 }
921
922 static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
923 {
924         return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0;
925 }
926
927 /**
928  * __skb_flow_dissect - extract the flow_keys struct and return it
929  * @net: associated network namespace, derived from @skb if NULL
930  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
931  * @flow_dissector: list of keys to dissect
932  * @target_container: target structure to put dissected values into
933  * @data: raw buffer pointer to the packet, if NULL use skb->data
934  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
935  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
936  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
937  * @flags: flags that control the dissection process, e.g.
938  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
939  *
940  * The function will try to retrieve individual keys into target specified
941  * by flow_dissector from either the skbuff or a raw buffer specified by the
942  * rest parameters.
943  *
944  * Caller must take care of zeroing target container memory.
945  */
946 bool __skb_flow_dissect(const struct net *net,
947                         const struct sk_buff *skb,
948                         struct flow_dissector *flow_dissector,
949                         void *target_container, const void *data,
950                         __be16 proto, int nhoff, int hlen, unsigned int flags)
951 {
952         struct flow_dissector_key_control *key_control;
953         struct flow_dissector_key_basic *key_basic;
954         struct flow_dissector_key_addrs *key_addrs;
955         struct flow_dissector_key_tags *key_tags;
956         struct flow_dissector_key_vlan *key_vlan;
957         enum flow_dissect_ret fdret;
958         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
959         bool mpls_el = false;
960         int mpls_lse = 0;
961         int num_hdrs = 0;
962         u8 ip_proto = 0;
963         bool ret;
964
965         if (!data) {
966                 data = skb->data;
967                 proto = skb_vlan_tag_present(skb) ?
968                          skb->vlan_proto : skb->protocol;
969                 nhoff = skb_network_offset(skb);
970                 hlen = skb_headlen(skb);
971 #if IS_ENABLED(CONFIG_NET_DSA)
972                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
973                              proto == htons(ETH_P_XDSA))) {
974                         struct metadata_dst *md_dst = skb_metadata_dst(skb);
975                         const struct dsa_device_ops *ops;
976                         int offset = 0;
977
978                         ops = skb->dev->dsa_ptr->tag_ops;
979                         /* Only DSA header taggers break flow dissection */
980                         if (ops->needed_headroom &&
981                             (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
982                                 if (ops->flow_dissect)
983                                         ops->flow_dissect(skb, &proto, &offset);
984                                 else
985                                         dsa_tag_generic_flow_dissect(skb,
986                                                                      &proto,
987                                                                      &offset);
988                                 hlen -= offset;
989                                 nhoff += offset;
990                         }
991                 }
992 #endif
993         }
994
995         /* It is ensured by skb_flow_dissector_init() that control key will
996          * be always present.
997          */
998         key_control = skb_flow_dissector_target(flow_dissector,
999                                                 FLOW_DISSECTOR_KEY_CONTROL,
1000                                                 target_container);
1001
1002         /* It is ensured by skb_flow_dissector_init() that basic key will
1003          * be always present.
1004          */
1005         key_basic = skb_flow_dissector_target(flow_dissector,
1006                                               FLOW_DISSECTOR_KEY_BASIC,
1007                                               target_container);
1008
1009         if (skb) {
1010                 if (!net) {
1011                         if (skb->dev)
1012                                 net = dev_net(skb->dev);
1013                         else if (skb->sk)
1014                                 net = sock_net(skb->sk);
1015                 }
1016         }
1017
1018         WARN_ON_ONCE(!net);
1019         if (net) {
1020                 enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
1021                 struct bpf_prog_array *run_array;
1022
1023                 rcu_read_lock();
1024                 run_array = rcu_dereference(init_net.bpf.run_array[type]);
1025                 if (!run_array)
1026                         run_array = rcu_dereference(net->bpf.run_array[type]);
1027
1028                 if (run_array) {
1029                         struct bpf_flow_keys flow_keys;
1030                         struct bpf_flow_dissector ctx = {
1031                                 .flow_keys = &flow_keys,
1032                                 .data = data,
1033                                 .data_end = data + hlen,
1034                         };
1035                         __be16 n_proto = proto;
1036                         struct bpf_prog *prog;
1037                         u32 result;
1038
1039                         if (skb) {
1040                                 ctx.skb = skb;
1041                                 /* we can't use 'proto' in the skb case
1042                                  * because it might be set to skb->vlan_proto
1043                                  * which has been pulled from the data
1044                                  */
1045                                 n_proto = skb->protocol;
1046                         }
1047
1048                         prog = READ_ONCE(run_array->items[0].prog);
1049                         result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
1050                                                   hlen, flags);
1051                         if (result == BPF_FLOW_DISSECTOR_CONTINUE)
1052                                 goto dissect_continue;
1053                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1054                                                  target_container);
1055                         rcu_read_unlock();
1056                         return result == BPF_OK;
1057                 }
1058 dissect_continue:
1059                 rcu_read_unlock();
1060         }
1061
1062         if (dissector_uses_key(flow_dissector,
1063                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1064                 struct ethhdr *eth = eth_hdr(skb);
1065                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
1066
1067                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1068                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
1069                                                           target_container);
1070                 memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs));
1071         }
1072
1073         if (dissector_uses_key(flow_dissector,
1074                                FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
1075                 struct flow_dissector_key_num_of_vlans *key_num_of_vlans;
1076
1077                 key_num_of_vlans = skb_flow_dissector_target(flow_dissector,
1078                                                              FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1079                                                              target_container);
1080                 key_num_of_vlans->num_of_vlans = 0;
1081         }
1082
1083 proto_again:
1084         fdret = FLOW_DISSECT_RET_CONTINUE;
1085
1086         switch (proto) {
1087         case htons(ETH_P_IP): {
1088                 const struct iphdr *iph;
1089                 struct iphdr _iph;
1090
1091                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1092                 if (!iph || iph->ihl < 5) {
1093                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1094                         break;
1095                 }
1096
1097                 nhoff += iph->ihl * 4;
1098
1099                 ip_proto = iph->protocol;
1100
1101                 if (dissector_uses_key(flow_dissector,
1102                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1103                         key_addrs = skb_flow_dissector_target(flow_dissector,
1104                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1105                                                               target_container);
1106
1107                         memcpy(&key_addrs->v4addrs.src, &iph->saddr,
1108                                sizeof(key_addrs->v4addrs.src));
1109                         memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
1110                                sizeof(key_addrs->v4addrs.dst));
1111                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1112                 }
1113
1114                 __skb_flow_dissect_ipv4(skb, flow_dissector,
1115                                         target_container, data, iph);
1116
1117                 if (ip_is_fragment(iph)) {
1118                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1119
1120                         if (iph->frag_off & htons(IP_OFFSET)) {
1121                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1122                                 break;
1123                         } else {
1124                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
1125                                 if (!(flags &
1126                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1127                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1128                                         break;
1129                                 }
1130                         }
1131                 }
1132
1133                 break;
1134         }
1135         case htons(ETH_P_IPV6): {
1136                 const struct ipv6hdr *iph;
1137                 struct ipv6hdr _iph;
1138
1139                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1140                 if (!iph) {
1141                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1142                         break;
1143                 }
1144
1145                 ip_proto = iph->nexthdr;
1146                 nhoff += sizeof(struct ipv6hdr);
1147
1148                 if (dissector_uses_key(flow_dissector,
1149                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1150                         key_addrs = skb_flow_dissector_target(flow_dissector,
1151                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1152                                                               target_container);
1153
1154                         memcpy(&key_addrs->v6addrs.src, &iph->saddr,
1155                                sizeof(key_addrs->v6addrs.src));
1156                         memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
1157                                sizeof(key_addrs->v6addrs.dst));
1158                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1159                 }
1160
1161                 if ((dissector_uses_key(flow_dissector,
1162                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1163                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1164                     ip6_flowlabel(iph)) {
1165                         __be32 flow_label = ip6_flowlabel(iph);
1166
1167                         if (dissector_uses_key(flow_dissector,
1168                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1169                                 key_tags = skb_flow_dissector_target(flow_dissector,
1170                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1171                                                                      target_container);
1172                                 key_tags->flow_label = ntohl(flow_label);
1173                         }
1174                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1175                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1176                                 break;
1177                         }
1178                 }
1179
1180                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1181                                         target_container, data, iph);
1182
1183                 break;
1184         }
1185         case htons(ETH_P_8021AD):
1186         case htons(ETH_P_8021Q): {
1187                 const struct vlan_hdr *vlan = NULL;
1188                 struct vlan_hdr _vlan;
1189                 __be16 saved_vlan_tpid = proto;
1190
1191                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1192                     skb && skb_vlan_tag_present(skb)) {
1193                         proto = skb->protocol;
1194                 } else {
1195                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1196                                                     data, hlen, &_vlan);
1197                         if (!vlan) {
1198                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1199                                 break;
1200                         }
1201
1202                         proto = vlan->h_vlan_encapsulated_proto;
1203                         nhoff += sizeof(*vlan);
1204                 }
1205
1206                 if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
1207                     !(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
1208                         struct flow_dissector_key_num_of_vlans *key_nvs;
1209
1210                         key_nvs = skb_flow_dissector_target(flow_dissector,
1211                                                             FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1212                                                             target_container);
1213                         key_nvs->num_of_vlans++;
1214                 }
1215
1216                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1217                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1218                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1219                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1220                 } else {
1221                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1222                         break;
1223                 }
1224
1225                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1226                         key_vlan = skb_flow_dissector_target(flow_dissector,
1227                                                              dissector_vlan,
1228                                                              target_container);
1229
1230                         if (!vlan) {
1231                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1232                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1233                         } else {
1234                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1235                                         VLAN_VID_MASK;
1236                                 key_vlan->vlan_priority =
1237                                         (ntohs(vlan->h_vlan_TCI) &
1238                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1239                         }
1240                         key_vlan->vlan_tpid = saved_vlan_tpid;
1241                         key_vlan->vlan_eth_type = proto;
1242                 }
1243
1244                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1245                 break;
1246         }
1247         case htons(ETH_P_PPP_SES): {
1248                 struct {
1249                         struct pppoe_hdr hdr;
1250                         __be16 proto;
1251                 } *hdr, _hdr;
1252                 u16 ppp_proto;
1253
1254                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1255                 if (!hdr) {
1256                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1257                         break;
1258                 }
1259
1260                 if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) {
1261                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1262                         break;
1263                 }
1264
1265                 /* least significant bit of the most significant octet
1266                  * indicates if protocol field was compressed
1267                  */
1268                 ppp_proto = ntohs(hdr->proto);
1269                 if (ppp_proto & 0x0100) {
1270                         ppp_proto = ppp_proto >> 8;
1271                         nhoff += PPPOE_SES_HLEN - 1;
1272                 } else {
1273                         nhoff += PPPOE_SES_HLEN;
1274                 }
1275
1276                 if (ppp_proto == PPP_IP) {
1277                         proto = htons(ETH_P_IP);
1278                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1279                 } else if (ppp_proto == PPP_IPV6) {
1280                         proto = htons(ETH_P_IPV6);
1281                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1282                 } else if (ppp_proto == PPP_MPLS_UC) {
1283                         proto = htons(ETH_P_MPLS_UC);
1284                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1285                 } else if (ppp_proto == PPP_MPLS_MC) {
1286                         proto = htons(ETH_P_MPLS_MC);
1287                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1288                 } else if (ppp_proto_is_valid(ppp_proto)) {
1289                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1290                 } else {
1291                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1292                         break;
1293                 }
1294
1295                 if (dissector_uses_key(flow_dissector,
1296                                        FLOW_DISSECTOR_KEY_PPPOE)) {
1297                         struct flow_dissector_key_pppoe *key_pppoe;
1298
1299                         key_pppoe = skb_flow_dissector_target(flow_dissector,
1300                                                               FLOW_DISSECTOR_KEY_PPPOE,
1301                                                               target_container);
1302                         key_pppoe->session_id = hdr->hdr.sid;
1303                         key_pppoe->ppp_proto = htons(ppp_proto);
1304                         key_pppoe->type = htons(ETH_P_PPP_SES);
1305                 }
1306                 break;
1307         }
1308         case htons(ETH_P_TIPC): {
1309                 struct tipc_basic_hdr *hdr, _hdr;
1310
1311                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1312                                            data, hlen, &_hdr);
1313                 if (!hdr) {
1314                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1315                         break;
1316                 }
1317
1318                 if (dissector_uses_key(flow_dissector,
1319                                        FLOW_DISSECTOR_KEY_TIPC)) {
1320                         key_addrs = skb_flow_dissector_target(flow_dissector,
1321                                                               FLOW_DISSECTOR_KEY_TIPC,
1322                                                               target_container);
1323                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1324                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1325                 }
1326                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1327                 break;
1328         }
1329
1330         case htons(ETH_P_MPLS_UC):
1331         case htons(ETH_P_MPLS_MC):
1332                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1333                                                 target_container, data,
1334                                                 nhoff, hlen, mpls_lse,
1335                                                 &mpls_el);
1336                 nhoff += sizeof(struct mpls_label);
1337                 mpls_lse++;
1338                 break;
1339         case htons(ETH_P_FCOE):
1340                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1341                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1342                         break;
1343                 }
1344
1345                 nhoff += FCOE_HEADER_LEN;
1346                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1347                 break;
1348
1349         case htons(ETH_P_ARP):
1350         case htons(ETH_P_RARP):
1351                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1352                                                target_container, data,
1353                                                nhoff, hlen);
1354                 break;
1355
1356         case htons(ETH_P_BATMAN):
1357                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1358                                                   &proto, &nhoff, hlen, flags);
1359                 break;
1360
1361         case htons(ETH_P_1588): {
1362                 struct ptp_header *hdr, _hdr;
1363
1364                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
1365                                            hlen, &_hdr);
1366                 if (!hdr) {
1367                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1368                         break;
1369                 }
1370
1371                 nhoff += ntohs(hdr->message_length);
1372                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1373                 break;
1374         }
1375
1376         case htons(ETH_P_PRP):
1377         case htons(ETH_P_HSR): {
1378                 struct hsr_tag *hdr, _hdr;
1379
1380                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen,
1381                                            &_hdr);
1382                 if (!hdr) {
1383                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1384                         break;
1385                 }
1386
1387                 proto = hdr->encap_proto;
1388                 nhoff += HSR_HLEN;
1389                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1390                 break;
1391         }
1392
1393         default:
1394                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1395                 break;
1396         }
1397
1398         /* Process result of proto processing */
1399         switch (fdret) {
1400         case FLOW_DISSECT_RET_OUT_GOOD:
1401                 goto out_good;
1402         case FLOW_DISSECT_RET_PROTO_AGAIN:
1403                 if (skb_flow_dissect_allowed(&num_hdrs))
1404                         goto proto_again;
1405                 goto out_good;
1406         case FLOW_DISSECT_RET_CONTINUE:
1407         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1408                 break;
1409         case FLOW_DISSECT_RET_OUT_BAD:
1410         default:
1411                 goto out_bad;
1412         }
1413
1414 ip_proto_again:
1415         fdret = FLOW_DISSECT_RET_CONTINUE;
1416
1417         switch (ip_proto) {
1418         case IPPROTO_GRE:
1419                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1420                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1421                         break;
1422                 }
1423
1424                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1425                                                target_container, data,
1426                                                &proto, &nhoff, &hlen, flags);
1427                 break;
1428
1429         case NEXTHDR_HOP:
1430         case NEXTHDR_ROUTING:
1431         case NEXTHDR_DEST: {
1432                 u8 _opthdr[2], *opthdr;
1433
1434                 if (proto != htons(ETH_P_IPV6))
1435                         break;
1436
1437                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1438                                               data, hlen, &_opthdr);
1439                 if (!opthdr) {
1440                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1441                         break;
1442                 }
1443
1444                 ip_proto = opthdr[0];
1445                 nhoff += (opthdr[1] + 1) << 3;
1446
1447                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1448                 break;
1449         }
1450         case NEXTHDR_FRAGMENT: {
1451                 struct frag_hdr _fh, *fh;
1452
1453                 if (proto != htons(ETH_P_IPV6))
1454                         break;
1455
1456                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1457                                           data, hlen, &_fh);
1458
1459                 if (!fh) {
1460                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1461                         break;
1462                 }
1463
1464                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1465
1466                 nhoff += sizeof(_fh);
1467                 ip_proto = fh->nexthdr;
1468
1469                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1470                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1471                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1472                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1473                                 break;
1474                         }
1475                 }
1476
1477                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1478                 break;
1479         }
1480         case IPPROTO_IPIP:
1481                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1482                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1483                         break;
1484                 }
1485
1486                 proto = htons(ETH_P_IP);
1487
1488                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1489                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1490                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1491                         break;
1492                 }
1493
1494                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1495                 break;
1496
1497         case IPPROTO_IPV6:
1498                 if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1499                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1500                         break;
1501                 }
1502
1503                 proto = htons(ETH_P_IPV6);
1504
1505                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1506                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1507                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1508                         break;
1509                 }
1510
1511                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1512                 break;
1513
1514
1515         case IPPROTO_MPLS:
1516                 proto = htons(ETH_P_MPLS_UC);
1517                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1518                 break;
1519
1520         case IPPROTO_TCP:
1521                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1522                                        data, nhoff, hlen);
1523                 break;
1524
1525         case IPPROTO_ICMP:
1526         case IPPROTO_ICMPV6:
1527                 __skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1528                                         data, nhoff, hlen);
1529                 break;
1530         case IPPROTO_L2TP:
1531                 __skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,
1532                                           data, nhoff, hlen);
1533                 break;
1534
1535         default:
1536                 break;
1537         }
1538
1539         if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1540                 __skb_flow_dissect_ports(skb, flow_dissector, target_container,
1541                                          data, nhoff, ip_proto, hlen);
1542
1543         /* Process result of IP proto processing */
1544         switch (fdret) {
1545         case FLOW_DISSECT_RET_PROTO_AGAIN:
1546                 if (skb_flow_dissect_allowed(&num_hdrs))
1547                         goto proto_again;
1548                 break;
1549         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1550                 if (skb_flow_dissect_allowed(&num_hdrs))
1551                         goto ip_proto_again;
1552                 break;
1553         case FLOW_DISSECT_RET_OUT_GOOD:
1554         case FLOW_DISSECT_RET_CONTINUE:
1555                 break;
1556         case FLOW_DISSECT_RET_OUT_BAD:
1557         default:
1558                 goto out_bad;
1559         }
1560
1561 out_good:
1562         ret = true;
1563
1564 out:
1565         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1566         key_basic->n_proto = proto;
1567         key_basic->ip_proto = ip_proto;
1568
1569         return ret;
1570
1571 out_bad:
1572         ret = false;
1573         goto out;
1574 }
1575 EXPORT_SYMBOL(__skb_flow_dissect);
1576
1577 static siphash_aligned_key_t hashrnd;
1578 static __always_inline void __flow_hash_secret_init(void)
1579 {
1580         net_get_random_once(&hashrnd, sizeof(hashrnd));
1581 }
1582
1583 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1584 {
1585         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1586         return &flow->FLOW_KEYS_HASH_START_FIELD;
1587 }
1588
1589 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1590 {
1591         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1592
1593         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1594
1595         switch (flow->control.addr_type) {
1596         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1597                 diff -= sizeof(flow->addrs.v4addrs);
1598                 break;
1599         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1600                 diff -= sizeof(flow->addrs.v6addrs);
1601                 break;
1602         case FLOW_DISSECTOR_KEY_TIPC:
1603                 diff -= sizeof(flow->addrs.tipckey);
1604                 break;
1605         }
1606         return sizeof(*flow) - diff;
1607 }
1608
1609 __be32 flow_get_u32_src(const struct flow_keys *flow)
1610 {
1611         switch (flow->control.addr_type) {
1612         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1613                 return flow->addrs.v4addrs.src;
1614         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1615                 return (__force __be32)ipv6_addr_hash(
1616                         &flow->addrs.v6addrs.src);
1617         case FLOW_DISSECTOR_KEY_TIPC:
1618                 return flow->addrs.tipckey.key;
1619         default:
1620                 return 0;
1621         }
1622 }
1623 EXPORT_SYMBOL(flow_get_u32_src);
1624
1625 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1626 {
1627         switch (flow->control.addr_type) {
1628         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1629                 return flow->addrs.v4addrs.dst;
1630         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1631                 return (__force __be32)ipv6_addr_hash(
1632                         &flow->addrs.v6addrs.dst);
1633         default:
1634                 return 0;
1635         }
1636 }
1637 EXPORT_SYMBOL(flow_get_u32_dst);
1638
1639 /* Sort the source and destination IP and the ports,
1640  * to have consistent hash within the two directions
1641  */
1642 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1643 {
1644         int addr_diff, i;
1645
1646         switch (keys->control.addr_type) {
1647         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1648                 if ((__force u32)keys->addrs.v4addrs.dst <
1649                     (__force u32)keys->addrs.v4addrs.src)
1650                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1651
1652                 if ((__force u16)keys->ports.dst <
1653                     (__force u16)keys->ports.src) {
1654                         swap(keys->ports.src, keys->ports.dst);
1655                 }
1656                 break;
1657         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1658                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1659                                    &keys->addrs.v6addrs.src,
1660                                    sizeof(keys->addrs.v6addrs.dst));
1661                 if (addr_diff < 0) {
1662                         for (i = 0; i < 4; i++)
1663                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1664                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1665                 }
1666                 if ((__force u16)keys->ports.dst <
1667                     (__force u16)keys->ports.src) {
1668                         swap(keys->ports.src, keys->ports.dst);
1669                 }
1670                 break;
1671         }
1672 }
1673
1674 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1675                                         const siphash_key_t *keyval)
1676 {
1677         u32 hash;
1678
1679         __flow_hash_consistentify(keys);
1680
1681         hash = siphash(flow_keys_hash_start(keys),
1682                        flow_keys_hash_length(keys), keyval);
1683         if (!hash)
1684                 hash = 1;
1685
1686         return hash;
1687 }
1688
1689 u32 flow_hash_from_keys(struct flow_keys *keys)
1690 {
1691         __flow_hash_secret_init();
1692         return __flow_hash_from_keys(keys, &hashrnd);
1693 }
1694 EXPORT_SYMBOL(flow_hash_from_keys);
1695
1696 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1697                                   struct flow_keys *keys,
1698                                   const siphash_key_t *keyval)
1699 {
1700         skb_flow_dissect_flow_keys(skb, keys,
1701                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1702
1703         return __flow_hash_from_keys(keys, keyval);
1704 }
1705
1706 struct _flow_keys_digest_data {
1707         __be16  n_proto;
1708         u8      ip_proto;
1709         u8      padding;
1710         __be32  ports;
1711         __be32  src;
1712         __be32  dst;
1713 };
1714
1715 void make_flow_keys_digest(struct flow_keys_digest *digest,
1716                            const struct flow_keys *flow)
1717 {
1718         struct _flow_keys_digest_data *data =
1719             (struct _flow_keys_digest_data *)digest;
1720
1721         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1722
1723         memset(digest, 0, sizeof(*digest));
1724
1725         data->n_proto = flow->basic.n_proto;
1726         data->ip_proto = flow->basic.ip_proto;
1727         data->ports = flow->ports.ports;
1728         data->src = flow->addrs.v4addrs.src;
1729         data->dst = flow->addrs.v4addrs.dst;
1730 }
1731 EXPORT_SYMBOL(make_flow_keys_digest);
1732
1733 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1734
1735 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1736 {
1737         struct flow_keys keys;
1738
1739         __flow_hash_secret_init();
1740
1741         memset(&keys, 0, sizeof(keys));
1742         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1743                            &keys, NULL, 0, 0, 0,
1744                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1745
1746         return __flow_hash_from_keys(&keys, &hashrnd);
1747 }
1748 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1749
1750 /**
1751  * __skb_get_hash: calculate a flow hash
1752  * @skb: sk_buff to calculate flow hash from
1753  *
1754  * This function calculates a flow hash based on src/dst addresses
1755  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1756  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1757  * if hash is a canonical 4-tuple hash over transport ports.
1758  */
1759 void __skb_get_hash(struct sk_buff *skb)
1760 {
1761         struct flow_keys keys;
1762         u32 hash;
1763
1764         __flow_hash_secret_init();
1765
1766         hash = ___skb_get_hash(skb, &keys, &hashrnd);
1767
1768         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1769 }
1770 EXPORT_SYMBOL(__skb_get_hash);
1771
1772 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1773                            const siphash_key_t *perturb)
1774 {
1775         struct flow_keys keys;
1776
1777         return ___skb_get_hash(skb, &keys, perturb);
1778 }
1779 EXPORT_SYMBOL(skb_get_hash_perturb);
1780
1781 u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1782                    const struct flow_keys_basic *keys, int hlen)
1783 {
1784         u32 poff = keys->control.thoff;
1785
1786         /* skip L4 headers for fragments after the first */
1787         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1788             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1789                 return poff;
1790
1791         switch (keys->basic.ip_proto) {
1792         case IPPROTO_TCP: {
1793                 /* access doff as u8 to avoid unaligned access */
1794                 const u8 *doff;
1795                 u8 _doff;
1796
1797                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1798                                             data, hlen, &_doff);
1799                 if (!doff)
1800                         return poff;
1801
1802                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1803                 break;
1804         }
1805         case IPPROTO_UDP:
1806         case IPPROTO_UDPLITE:
1807                 poff += sizeof(struct udphdr);
1808                 break;
1809         /* For the rest, we do not really care about header
1810          * extensions at this point for now.
1811          */
1812         case IPPROTO_ICMP:
1813                 poff += sizeof(struct icmphdr);
1814                 break;
1815         case IPPROTO_ICMPV6:
1816                 poff += sizeof(struct icmp6hdr);
1817                 break;
1818         case IPPROTO_IGMP:
1819                 poff += sizeof(struct igmphdr);
1820                 break;
1821         case IPPROTO_DCCP:
1822                 poff += sizeof(struct dccp_hdr);
1823                 break;
1824         case IPPROTO_SCTP:
1825                 poff += sizeof(struct sctphdr);
1826                 break;
1827         }
1828
1829         return poff;
1830 }
1831
1832 /**
1833  * skb_get_poff - get the offset to the payload
1834  * @skb: sk_buff to get the payload offset from
1835  *
1836  * The function will get the offset to the payload as far as it could
1837  * be dissected.  The main user is currently BPF, so that we can dynamically
1838  * truncate packets without needing to push actual payload to the user
1839  * space and can analyze headers only, instead.
1840  */
1841 u32 skb_get_poff(const struct sk_buff *skb)
1842 {
1843         struct flow_keys_basic keys;
1844
1845         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1846                                               NULL, 0, 0, 0, 0))
1847                 return 0;
1848
1849         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1850 }
1851
1852 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1853 {
1854         memset(keys, 0, sizeof(*keys));
1855
1856         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1857             sizeof(keys->addrs.v6addrs.src));
1858         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1859             sizeof(keys->addrs.v6addrs.dst));
1860         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1861         keys->ports.src = fl6->fl6_sport;
1862         keys->ports.dst = fl6->fl6_dport;
1863         keys->keyid.keyid = fl6->fl6_gre_key;
1864         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1865         keys->basic.ip_proto = fl6->flowi6_proto;
1866
1867         return flow_hash_from_keys(keys);
1868 }
1869 EXPORT_SYMBOL(__get_hash_from_flowi6);
1870
1871 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1872         {
1873                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1874                 .offset = offsetof(struct flow_keys, control),
1875         },
1876         {
1877                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1878                 .offset = offsetof(struct flow_keys, basic),
1879         },
1880         {
1881                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1882                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1883         },
1884         {
1885                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1886                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1887         },
1888         {
1889                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1890                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1891         },
1892         {
1893                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1894                 .offset = offsetof(struct flow_keys, ports),
1895         },
1896         {
1897                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1898                 .offset = offsetof(struct flow_keys, vlan),
1899         },
1900         {
1901                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1902                 .offset = offsetof(struct flow_keys, tags),
1903         },
1904         {
1905                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1906                 .offset = offsetof(struct flow_keys, keyid),
1907         },
1908 };
1909
1910 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1911         {
1912                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1913                 .offset = offsetof(struct flow_keys, control),
1914         },
1915         {
1916                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1917                 .offset = offsetof(struct flow_keys, basic),
1918         },
1919         {
1920                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1921                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1922         },
1923         {
1924                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1925                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1926         },
1927         {
1928                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1929                 .offset = offsetof(struct flow_keys, ports),
1930         },
1931 };
1932
1933 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1934         {
1935                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1936                 .offset = offsetof(struct flow_keys, control),
1937         },
1938         {
1939                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1940                 .offset = offsetof(struct flow_keys, basic),
1941         },
1942 };
1943
1944 struct flow_dissector flow_keys_dissector __read_mostly;
1945 EXPORT_SYMBOL(flow_keys_dissector);
1946
1947 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1948 EXPORT_SYMBOL(flow_keys_basic_dissector);
1949
1950 static int __init init_default_flow_dissectors(void)
1951 {
1952         skb_flow_dissector_init(&flow_keys_dissector,
1953                                 flow_keys_dissector_keys,
1954                                 ARRAY_SIZE(flow_keys_dissector_keys));
1955         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1956                                 flow_keys_dissector_symmetric_keys,
1957                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1958         skb_flow_dissector_init(&flow_keys_basic_dissector,
1959                                 flow_keys_basic_dissector_keys,
1960                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1961         return 0;
1962 }
1963 core_initcall(init_default_flow_dissectors);