Merge branch 'readdir' (readdir speedup and sanity checking)
[linux-2.6-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 <net/dsa.h>
9 #include <net/dst_metadata.h>
10 #include <net/ip.h>
11 #include <net/ipv6.h>
12 #include <net/gre.h>
13 #include <net/pptp.h>
14 #include <net/tipc.h>
15 #include <linux/igmp.h>
16 #include <linux/icmp.h>
17 #include <linux/sctp.h>
18 #include <linux/dccp.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/if_pppox.h>
21 #include <linux/ppp_defs.h>
22 #include <linux/stddef.h>
23 #include <linux/if_ether.h>
24 #include <linux/mpls.h>
25 #include <linux/tcp.h>
26 #include <net/flow_dissector.h>
27 #include <scsi/fc/fc_fcoe.h>
28 #include <uapi/linux/batadv_packet.h>
29 #include <linux/bpf.h>
30 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
31 #include <net/netfilter/nf_conntrack_core.h>
32 #include <net/netfilter/nf_conntrack_labels.h>
33 #endif
34
35 static DEFINE_MUTEX(flow_dissector_mutex);
36
37 static void dissector_set_key(struct flow_dissector *flow_dissector,
38                               enum flow_dissector_key_id key_id)
39 {
40         flow_dissector->used_keys |= (1 << key_id);
41 }
42
43 void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
44                              const struct flow_dissector_key *key,
45                              unsigned int key_count)
46 {
47         unsigned int i;
48
49         memset(flow_dissector, 0, sizeof(*flow_dissector));
50
51         for (i = 0; i < key_count; i++, key++) {
52                 /* User should make sure that every key target offset is withing
53                  * boundaries of unsigned short.
54                  */
55                 BUG_ON(key->offset > USHRT_MAX);
56                 BUG_ON(dissector_uses_key(flow_dissector,
57                                           key->key_id));
58
59                 dissector_set_key(flow_dissector, key->key_id);
60                 flow_dissector->offset[key->key_id] = key->offset;
61         }
62
63         /* Ensure that the dissector always includes control and basic key.
64          * That way we are able to avoid handling lack of these in fast path.
65          */
66         BUG_ON(!dissector_uses_key(flow_dissector,
67                                    FLOW_DISSECTOR_KEY_CONTROL));
68         BUG_ON(!dissector_uses_key(flow_dissector,
69                                    FLOW_DISSECTOR_KEY_BASIC));
70 }
71 EXPORT_SYMBOL(skb_flow_dissector_init);
72
73 int skb_flow_dissector_prog_query(const union bpf_attr *attr,
74                                   union bpf_attr __user *uattr)
75 {
76         __u32 __user *prog_ids = u64_to_user_ptr(attr->query.prog_ids);
77         u32 prog_id, prog_cnt = 0, flags = 0;
78         struct bpf_prog *attached;
79         struct net *net;
80
81         if (attr->query.query_flags)
82                 return -EINVAL;
83
84         net = get_net_ns_by_fd(attr->query.target_fd);
85         if (IS_ERR(net))
86                 return PTR_ERR(net);
87
88         rcu_read_lock();
89         attached = rcu_dereference(net->flow_dissector_prog);
90         if (attached) {
91                 prog_cnt = 1;
92                 prog_id = attached->aux->id;
93         }
94         rcu_read_unlock();
95
96         put_net(net);
97
98         if (copy_to_user(&uattr->query.attach_flags, &flags, sizeof(flags)))
99                 return -EFAULT;
100         if (copy_to_user(&uattr->query.prog_cnt, &prog_cnt, sizeof(prog_cnt)))
101                 return -EFAULT;
102
103         if (!attr->query.prog_cnt || !prog_ids || !prog_cnt)
104                 return 0;
105
106         if (copy_to_user(prog_ids, &prog_id, sizeof(u32)))
107                 return -EFAULT;
108
109         return 0;
110 }
111
112 int skb_flow_dissector_bpf_prog_attach(const union bpf_attr *attr,
113                                        struct bpf_prog *prog)
114 {
115         struct bpf_prog *attached;
116         struct net *net;
117
118         net = current->nsproxy->net_ns;
119         mutex_lock(&flow_dissector_mutex);
120         attached = rcu_dereference_protected(net->flow_dissector_prog,
121                                              lockdep_is_held(&flow_dissector_mutex));
122         if (attached) {
123                 /* Only one BPF program can be attached at a time */
124                 mutex_unlock(&flow_dissector_mutex);
125                 return -EEXIST;
126         }
127         rcu_assign_pointer(net->flow_dissector_prog, prog);
128         mutex_unlock(&flow_dissector_mutex);
129         return 0;
130 }
131
132 int skb_flow_dissector_bpf_prog_detach(const union bpf_attr *attr)
133 {
134         struct bpf_prog *attached;
135         struct net *net;
136
137         net = current->nsproxy->net_ns;
138         mutex_lock(&flow_dissector_mutex);
139         attached = rcu_dereference_protected(net->flow_dissector_prog,
140                                              lockdep_is_held(&flow_dissector_mutex));
141         if (!attached) {
142                 mutex_unlock(&flow_dissector_mutex);
143                 return -ENOENT;
144         }
145         RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
146         bpf_prog_put(attached);
147         mutex_unlock(&flow_dissector_mutex);
148         return 0;
149 }
150 /**
151  * skb_flow_get_be16 - extract be16 entity
152  * @skb: sk_buff to extract from
153  * @poff: offset to extract at
154  * @data: raw buffer pointer to the packet
155  * @hlen: packet header length
156  *
157  * The function will try to retrieve a be32 entity at
158  * offset poff
159  */
160 static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
161                                 void *data, int hlen)
162 {
163         __be16 *u, _u;
164
165         u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
166         if (u)
167                 return *u;
168
169         return 0;
170 }
171
172 /**
173  * __skb_flow_get_ports - extract the upper layer ports and return them
174  * @skb: sk_buff to extract the ports from
175  * @thoff: transport header offset
176  * @ip_proto: protocol for which to get port offset
177  * @data: raw buffer pointer to the packet, if NULL use skb->data
178  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
179  *
180  * The function will try to retrieve the ports at offset thoff + poff where poff
181  * is the protocol port offset returned from proto_ports_offset
182  */
183 __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
184                             void *data, int hlen)
185 {
186         int poff = proto_ports_offset(ip_proto);
187
188         if (!data) {
189                 data = skb->data;
190                 hlen = skb_headlen(skb);
191         }
192
193         if (poff >= 0) {
194                 __be32 *ports, _ports;
195
196                 ports = __skb_header_pointer(skb, thoff + poff,
197                                              sizeof(_ports), data, hlen, &_ports);
198                 if (ports)
199                         return *ports;
200         }
201
202         return 0;
203 }
204 EXPORT_SYMBOL(__skb_flow_get_ports);
205
206 void skb_flow_dissect_meta(const struct sk_buff *skb,
207                            struct flow_dissector *flow_dissector,
208                            void *target_container)
209 {
210         struct flow_dissector_key_meta *meta;
211
212         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
213                 return;
214
215         meta = skb_flow_dissector_target(flow_dissector,
216                                          FLOW_DISSECTOR_KEY_META,
217                                          target_container);
218         meta->ingress_ifindex = skb->skb_iif;
219 }
220 EXPORT_SYMBOL(skb_flow_dissect_meta);
221
222 static void
223 skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
224                                    struct flow_dissector *flow_dissector,
225                                    void *target_container)
226 {
227         struct flow_dissector_key_control *ctrl;
228
229         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
230                 return;
231
232         ctrl = skb_flow_dissector_target(flow_dissector,
233                                          FLOW_DISSECTOR_KEY_ENC_CONTROL,
234                                          target_container);
235         ctrl->addr_type = type;
236 }
237
238 void
239 skb_flow_dissect_ct(const struct sk_buff *skb,
240                     struct flow_dissector *flow_dissector,
241                     void *target_container,
242                     u16 *ctinfo_map,
243                     size_t mapsize)
244 {
245 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
246         struct flow_dissector_key_ct *key;
247         enum ip_conntrack_info ctinfo;
248         struct nf_conn_labels *cl;
249         struct nf_conn *ct;
250
251         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
252                 return;
253
254         ct = nf_ct_get(skb, &ctinfo);
255         if (!ct)
256                 return;
257
258         key = skb_flow_dissector_target(flow_dissector,
259                                         FLOW_DISSECTOR_KEY_CT,
260                                         target_container);
261
262         if (ctinfo < mapsize)
263                 key->ct_state = ctinfo_map[ctinfo];
264 #if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
265         key->ct_zone = ct->zone.id;
266 #endif
267 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
268         key->ct_mark = ct->mark;
269 #endif
270
271         cl = nf_ct_labels_find(ct);
272         if (cl)
273                 memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
274 #endif /* CONFIG_NF_CONNTRACK */
275 }
276 EXPORT_SYMBOL(skb_flow_dissect_ct);
277
278 void
279 skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
280                              struct flow_dissector *flow_dissector,
281                              void *target_container)
282 {
283         struct ip_tunnel_info *info;
284         struct ip_tunnel_key *key;
285
286         /* A quick check to see if there might be something to do. */
287         if (!dissector_uses_key(flow_dissector,
288                                 FLOW_DISSECTOR_KEY_ENC_KEYID) &&
289             !dissector_uses_key(flow_dissector,
290                                 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
291             !dissector_uses_key(flow_dissector,
292                                 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
293             !dissector_uses_key(flow_dissector,
294                                 FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
295             !dissector_uses_key(flow_dissector,
296                                 FLOW_DISSECTOR_KEY_ENC_PORTS) &&
297             !dissector_uses_key(flow_dissector,
298                                 FLOW_DISSECTOR_KEY_ENC_IP) &&
299             !dissector_uses_key(flow_dissector,
300                                 FLOW_DISSECTOR_KEY_ENC_OPTS))
301                 return;
302
303         info = skb_tunnel_info(skb);
304         if (!info)
305                 return;
306
307         key = &info->key;
308
309         switch (ip_tunnel_info_af(info)) {
310         case AF_INET:
311                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
312                                                    flow_dissector,
313                                                    target_container);
314                 if (dissector_uses_key(flow_dissector,
315                                        FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
316                         struct flow_dissector_key_ipv4_addrs *ipv4;
317
318                         ipv4 = skb_flow_dissector_target(flow_dissector,
319                                                          FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
320                                                          target_container);
321                         ipv4->src = key->u.ipv4.src;
322                         ipv4->dst = key->u.ipv4.dst;
323                 }
324                 break;
325         case AF_INET6:
326                 skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
327                                                    flow_dissector,
328                                                    target_container);
329                 if (dissector_uses_key(flow_dissector,
330                                        FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
331                         struct flow_dissector_key_ipv6_addrs *ipv6;
332
333                         ipv6 = skb_flow_dissector_target(flow_dissector,
334                                                          FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
335                                                          target_container);
336                         ipv6->src = key->u.ipv6.src;
337                         ipv6->dst = key->u.ipv6.dst;
338                 }
339                 break;
340         }
341
342         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
343                 struct flow_dissector_key_keyid *keyid;
344
345                 keyid = skb_flow_dissector_target(flow_dissector,
346                                                   FLOW_DISSECTOR_KEY_ENC_KEYID,
347                                                   target_container);
348                 keyid->keyid = tunnel_id_to_key32(key->tun_id);
349         }
350
351         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
352                 struct flow_dissector_key_ports *tp;
353
354                 tp = skb_flow_dissector_target(flow_dissector,
355                                                FLOW_DISSECTOR_KEY_ENC_PORTS,
356                                                target_container);
357                 tp->src = key->tp_src;
358                 tp->dst = key->tp_dst;
359         }
360
361         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
362                 struct flow_dissector_key_ip *ip;
363
364                 ip = skb_flow_dissector_target(flow_dissector,
365                                                FLOW_DISSECTOR_KEY_ENC_IP,
366                                                target_container);
367                 ip->tos = key->tos;
368                 ip->ttl = key->ttl;
369         }
370
371         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
372                 struct flow_dissector_key_enc_opts *enc_opt;
373
374                 enc_opt = skb_flow_dissector_target(flow_dissector,
375                                                     FLOW_DISSECTOR_KEY_ENC_OPTS,
376                                                     target_container);
377
378                 if (info->options_len) {
379                         enc_opt->len = info->options_len;
380                         ip_tunnel_info_opts_get(enc_opt->data, info);
381                         enc_opt->dst_opt_type = info->key.tun_flags &
382                                                 TUNNEL_OPTIONS_PRESENT;
383                 }
384         }
385 }
386 EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
387
388 static enum flow_dissect_ret
389 __skb_flow_dissect_mpls(const struct sk_buff *skb,
390                         struct flow_dissector *flow_dissector,
391                         void *target_container, void *data, int nhoff, int hlen)
392 {
393         struct flow_dissector_key_keyid *key_keyid;
394         struct mpls_label *hdr, _hdr[2];
395         u32 entry, label;
396
397         if (!dissector_uses_key(flow_dissector,
398                                 FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
399             !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
400                 return FLOW_DISSECT_RET_OUT_GOOD;
401
402         hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
403                                    hlen, &_hdr);
404         if (!hdr)
405                 return FLOW_DISSECT_RET_OUT_BAD;
406
407         entry = ntohl(hdr[0].entry);
408         label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
409
410         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
411                 struct flow_dissector_key_mpls *key_mpls;
412
413                 key_mpls = skb_flow_dissector_target(flow_dissector,
414                                                      FLOW_DISSECTOR_KEY_MPLS,
415                                                      target_container);
416                 key_mpls->mpls_label = label;
417                 key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
418                                         >> MPLS_LS_TTL_SHIFT;
419                 key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
420                                         >> MPLS_LS_TC_SHIFT;
421                 key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
422                                         >> MPLS_LS_S_SHIFT;
423         }
424
425         if (label == MPLS_LABEL_ENTROPY) {
426                 key_keyid = skb_flow_dissector_target(flow_dissector,
427                                                       FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
428                                                       target_container);
429                 key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
430         }
431         return FLOW_DISSECT_RET_OUT_GOOD;
432 }
433
434 static enum flow_dissect_ret
435 __skb_flow_dissect_arp(const struct sk_buff *skb,
436                        struct flow_dissector *flow_dissector,
437                        void *target_container, void *data, int nhoff, int hlen)
438 {
439         struct flow_dissector_key_arp *key_arp;
440         struct {
441                 unsigned char ar_sha[ETH_ALEN];
442                 unsigned char ar_sip[4];
443                 unsigned char ar_tha[ETH_ALEN];
444                 unsigned char ar_tip[4];
445         } *arp_eth, _arp_eth;
446         const struct arphdr *arp;
447         struct arphdr _arp;
448
449         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
450                 return FLOW_DISSECT_RET_OUT_GOOD;
451
452         arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
453                                    hlen, &_arp);
454         if (!arp)
455                 return FLOW_DISSECT_RET_OUT_BAD;
456
457         if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
458             arp->ar_pro != htons(ETH_P_IP) ||
459             arp->ar_hln != ETH_ALEN ||
460             arp->ar_pln != 4 ||
461             (arp->ar_op != htons(ARPOP_REPLY) &&
462              arp->ar_op != htons(ARPOP_REQUEST)))
463                 return FLOW_DISSECT_RET_OUT_BAD;
464
465         arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
466                                        sizeof(_arp_eth), data,
467                                        hlen, &_arp_eth);
468         if (!arp_eth)
469                 return FLOW_DISSECT_RET_OUT_BAD;
470
471         key_arp = skb_flow_dissector_target(flow_dissector,
472                                             FLOW_DISSECTOR_KEY_ARP,
473                                             target_container);
474
475         memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
476         memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
477
478         /* Only store the lower byte of the opcode;
479          * this covers ARPOP_REPLY and ARPOP_REQUEST.
480          */
481         key_arp->op = ntohs(arp->ar_op) & 0xff;
482
483         ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
484         ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
485
486         return FLOW_DISSECT_RET_OUT_GOOD;
487 }
488
489 static enum flow_dissect_ret
490 __skb_flow_dissect_gre(const struct sk_buff *skb,
491                        struct flow_dissector_key_control *key_control,
492                        struct flow_dissector *flow_dissector,
493                        void *target_container, void *data,
494                        __be16 *p_proto, int *p_nhoff, int *p_hlen,
495                        unsigned int flags)
496 {
497         struct flow_dissector_key_keyid *key_keyid;
498         struct gre_base_hdr *hdr, _hdr;
499         int offset = 0;
500         u16 gre_ver;
501
502         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
503                                    data, *p_hlen, &_hdr);
504         if (!hdr)
505                 return FLOW_DISSECT_RET_OUT_BAD;
506
507         /* Only look inside GRE without routing */
508         if (hdr->flags & GRE_ROUTING)
509                 return FLOW_DISSECT_RET_OUT_GOOD;
510
511         /* Only look inside GRE for version 0 and 1 */
512         gre_ver = ntohs(hdr->flags & GRE_VERSION);
513         if (gre_ver > 1)
514                 return FLOW_DISSECT_RET_OUT_GOOD;
515
516         *p_proto = hdr->protocol;
517         if (gre_ver) {
518                 /* Version1 must be PPTP, and check the flags */
519                 if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
520                         return FLOW_DISSECT_RET_OUT_GOOD;
521         }
522
523         offset += sizeof(struct gre_base_hdr);
524
525         if (hdr->flags & GRE_CSUM)
526                 offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
527                           FIELD_SIZEOF(struct gre_full_hdr, reserved1);
528
529         if (hdr->flags & GRE_KEY) {
530                 const __be32 *keyid;
531                 __be32 _keyid;
532
533                 keyid = __skb_header_pointer(skb, *p_nhoff + offset,
534                                              sizeof(_keyid),
535                                              data, *p_hlen, &_keyid);
536                 if (!keyid)
537                         return FLOW_DISSECT_RET_OUT_BAD;
538
539                 if (dissector_uses_key(flow_dissector,
540                                        FLOW_DISSECTOR_KEY_GRE_KEYID)) {
541                         key_keyid = skb_flow_dissector_target(flow_dissector,
542                                                               FLOW_DISSECTOR_KEY_GRE_KEYID,
543                                                               target_container);
544                         if (gre_ver == 0)
545                                 key_keyid->keyid = *keyid;
546                         else
547                                 key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
548                 }
549                 offset += FIELD_SIZEOF(struct gre_full_hdr, key);
550         }
551
552         if (hdr->flags & GRE_SEQ)
553                 offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
554
555         if (gre_ver == 0) {
556                 if (*p_proto == htons(ETH_P_TEB)) {
557                         const struct ethhdr *eth;
558                         struct ethhdr _eth;
559
560                         eth = __skb_header_pointer(skb, *p_nhoff + offset,
561                                                    sizeof(_eth),
562                                                    data, *p_hlen, &_eth);
563                         if (!eth)
564                                 return FLOW_DISSECT_RET_OUT_BAD;
565                         *p_proto = eth->h_proto;
566                         offset += sizeof(*eth);
567
568                         /* Cap headers that we access via pointers at the
569                          * end of the Ethernet header as our maximum alignment
570                          * at that point is only 2 bytes.
571                          */
572                         if (NET_IP_ALIGN)
573                                 *p_hlen = *p_nhoff + offset;
574                 }
575         } else { /* version 1, must be PPTP */
576                 u8 _ppp_hdr[PPP_HDRLEN];
577                 u8 *ppp_hdr;
578
579                 if (hdr->flags & GRE_ACK)
580                         offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
581
582                 ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
583                                                sizeof(_ppp_hdr),
584                                                data, *p_hlen, _ppp_hdr);
585                 if (!ppp_hdr)
586                         return FLOW_DISSECT_RET_OUT_BAD;
587
588                 switch (PPP_PROTOCOL(ppp_hdr)) {
589                 case PPP_IP:
590                         *p_proto = htons(ETH_P_IP);
591                         break;
592                 case PPP_IPV6:
593                         *p_proto = htons(ETH_P_IPV6);
594                         break;
595                 default:
596                         /* Could probably catch some more like MPLS */
597                         break;
598                 }
599
600                 offset += PPP_HDRLEN;
601         }
602
603         *p_nhoff += offset;
604         key_control->flags |= FLOW_DIS_ENCAPSULATION;
605         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
606                 return FLOW_DISSECT_RET_OUT_GOOD;
607
608         return FLOW_DISSECT_RET_PROTO_AGAIN;
609 }
610
611 /**
612  * __skb_flow_dissect_batadv() - dissect batman-adv header
613  * @skb: sk_buff to with the batman-adv header
614  * @key_control: flow dissectors control key
615  * @data: raw buffer pointer to the packet, if NULL use skb->data
616  * @p_proto: pointer used to update the protocol to process next
617  * @p_nhoff: pointer used to update inner network header offset
618  * @hlen: packet header length
619  * @flags: any combination of FLOW_DISSECTOR_F_*
620  *
621  * ETH_P_BATMAN packets are tried to be dissected. Only
622  * &struct batadv_unicast packets are actually processed because they contain an
623  * inner ethernet header and are usually followed by actual network header. This
624  * allows the flow dissector to continue processing the packet.
625  *
626  * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
627  *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
628  *  otherwise FLOW_DISSECT_RET_OUT_BAD
629  */
630 static enum flow_dissect_ret
631 __skb_flow_dissect_batadv(const struct sk_buff *skb,
632                           struct flow_dissector_key_control *key_control,
633                           void *data, __be16 *p_proto, int *p_nhoff, int hlen,
634                           unsigned int flags)
635 {
636         struct {
637                 struct batadv_unicast_packet batadv_unicast;
638                 struct ethhdr eth;
639         } *hdr, _hdr;
640
641         hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
642                                    &_hdr);
643         if (!hdr)
644                 return FLOW_DISSECT_RET_OUT_BAD;
645
646         if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
647                 return FLOW_DISSECT_RET_OUT_BAD;
648
649         if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
650                 return FLOW_DISSECT_RET_OUT_BAD;
651
652         *p_proto = hdr->eth.h_proto;
653         *p_nhoff += sizeof(*hdr);
654
655         key_control->flags |= FLOW_DIS_ENCAPSULATION;
656         if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
657                 return FLOW_DISSECT_RET_OUT_GOOD;
658
659         return FLOW_DISSECT_RET_PROTO_AGAIN;
660 }
661
662 static void
663 __skb_flow_dissect_tcp(const struct sk_buff *skb,
664                        struct flow_dissector *flow_dissector,
665                        void *target_container, void *data, int thoff, int hlen)
666 {
667         struct flow_dissector_key_tcp *key_tcp;
668         struct tcphdr *th, _th;
669
670         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
671                 return;
672
673         th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
674         if (!th)
675                 return;
676
677         if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
678                 return;
679
680         key_tcp = skb_flow_dissector_target(flow_dissector,
681                                             FLOW_DISSECTOR_KEY_TCP,
682                                             target_container);
683         key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
684 }
685
686 static void
687 __skb_flow_dissect_ipv4(const struct sk_buff *skb,
688                         struct flow_dissector *flow_dissector,
689                         void *target_container, void *data, const struct iphdr *iph)
690 {
691         struct flow_dissector_key_ip *key_ip;
692
693         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
694                 return;
695
696         key_ip = skb_flow_dissector_target(flow_dissector,
697                                            FLOW_DISSECTOR_KEY_IP,
698                                            target_container);
699         key_ip->tos = iph->tos;
700         key_ip->ttl = iph->ttl;
701 }
702
703 static void
704 __skb_flow_dissect_ipv6(const struct sk_buff *skb,
705                         struct flow_dissector *flow_dissector,
706                         void *target_container, void *data, const struct ipv6hdr *iph)
707 {
708         struct flow_dissector_key_ip *key_ip;
709
710         if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
711                 return;
712
713         key_ip = skb_flow_dissector_target(flow_dissector,
714                                            FLOW_DISSECTOR_KEY_IP,
715                                            target_container);
716         key_ip->tos = ipv6_get_dsfield(iph);
717         key_ip->ttl = iph->hop_limit;
718 }
719
720 /* Maximum number of protocol headers that can be parsed in
721  * __skb_flow_dissect
722  */
723 #define MAX_FLOW_DISSECT_HDRS   15
724
725 static bool skb_flow_dissect_allowed(int *num_hdrs)
726 {
727         ++*num_hdrs;
728
729         return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
730 }
731
732 static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
733                                      struct flow_dissector *flow_dissector,
734                                      void *target_container)
735 {
736         struct flow_dissector_key_control *key_control;
737         struct flow_dissector_key_basic *key_basic;
738         struct flow_dissector_key_addrs *key_addrs;
739         struct flow_dissector_key_ports *key_ports;
740         struct flow_dissector_key_tags *key_tags;
741
742         key_control = skb_flow_dissector_target(flow_dissector,
743                                                 FLOW_DISSECTOR_KEY_CONTROL,
744                                                 target_container);
745         key_control->thoff = flow_keys->thoff;
746         if (flow_keys->is_frag)
747                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
748         if (flow_keys->is_first_frag)
749                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
750         if (flow_keys->is_encap)
751                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
752
753         key_basic = skb_flow_dissector_target(flow_dissector,
754                                               FLOW_DISSECTOR_KEY_BASIC,
755                                               target_container);
756         key_basic->n_proto = flow_keys->n_proto;
757         key_basic->ip_proto = flow_keys->ip_proto;
758
759         if (flow_keys->addr_proto == ETH_P_IP &&
760             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
761                 key_addrs = skb_flow_dissector_target(flow_dissector,
762                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
763                                                       target_container);
764                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
765                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
766                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
767         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
768                    dissector_uses_key(flow_dissector,
769                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
770                 key_addrs = skb_flow_dissector_target(flow_dissector,
771                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
772                                                       target_container);
773                 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
774                        sizeof(key_addrs->v6addrs));
775                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
776         }
777
778         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
779                 key_ports = skb_flow_dissector_target(flow_dissector,
780                                                       FLOW_DISSECTOR_KEY_PORTS,
781                                                       target_container);
782                 key_ports->src = flow_keys->sport;
783                 key_ports->dst = flow_keys->dport;
784         }
785
786         if (dissector_uses_key(flow_dissector,
787                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
788                 key_tags = skb_flow_dissector_target(flow_dissector,
789                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
790                                                      target_container);
791                 key_tags->flow_label = ntohl(flow_keys->flow_label);
792         }
793 }
794
795 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
796                       __be16 proto, int nhoff, int hlen, unsigned int flags)
797 {
798         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
799         u32 result;
800
801         /* Pass parameters to the BPF program */
802         memset(flow_keys, 0, sizeof(*flow_keys));
803         flow_keys->n_proto = proto;
804         flow_keys->nhoff = nhoff;
805         flow_keys->thoff = flow_keys->nhoff;
806
807         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
808                      (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
809         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
810                      (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
811         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
812                      (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
813         flow_keys->flags = flags;
814
815         preempt_disable();
816         result = BPF_PROG_RUN(prog, ctx);
817         preempt_enable();
818
819         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
820         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
821                                    flow_keys->nhoff, hlen);
822
823         return result == BPF_OK;
824 }
825
826 /**
827  * __skb_flow_dissect - extract the flow_keys struct and return it
828  * @net: associated network namespace, derived from @skb if NULL
829  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
830  * @flow_dissector: list of keys to dissect
831  * @target_container: target structure to put dissected values into
832  * @data: raw buffer pointer to the packet, if NULL use skb->data
833  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
834  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
835  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
836  * @flags: flags that control the dissection process, e.g.
837  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
838  *
839  * The function will try to retrieve individual keys into target specified
840  * by flow_dissector from either the skbuff or a raw buffer specified by the
841  * rest parameters.
842  *
843  * Caller must take care of zeroing target container memory.
844  */
845 bool __skb_flow_dissect(const struct net *net,
846                         const struct sk_buff *skb,
847                         struct flow_dissector *flow_dissector,
848                         void *target_container,
849                         void *data, __be16 proto, int nhoff, int hlen,
850                         unsigned int flags)
851 {
852         struct flow_dissector_key_control *key_control;
853         struct flow_dissector_key_basic *key_basic;
854         struct flow_dissector_key_addrs *key_addrs;
855         struct flow_dissector_key_ports *key_ports;
856         struct flow_dissector_key_icmp *key_icmp;
857         struct flow_dissector_key_tags *key_tags;
858         struct flow_dissector_key_vlan *key_vlan;
859         struct bpf_prog *attached = NULL;
860         enum flow_dissect_ret fdret;
861         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
862         int num_hdrs = 0;
863         u8 ip_proto = 0;
864         bool ret;
865
866         if (!data) {
867                 data = skb->data;
868                 proto = skb_vlan_tag_present(skb) ?
869                          skb->vlan_proto : skb->protocol;
870                 nhoff = skb_network_offset(skb);
871                 hlen = skb_headlen(skb);
872 #if IS_ENABLED(CONFIG_NET_DSA)
873                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
874                         const struct dsa_device_ops *ops;
875                         int offset;
876
877                         ops = skb->dev->dsa_ptr->tag_ops;
878                         if (ops->flow_dissect &&
879                             !ops->flow_dissect(skb, &proto, &offset)) {
880                                 hlen -= offset;
881                                 nhoff += offset;
882                         }
883                 }
884 #endif
885         }
886
887         /* It is ensured by skb_flow_dissector_init() that control key will
888          * be always present.
889          */
890         key_control = skb_flow_dissector_target(flow_dissector,
891                                                 FLOW_DISSECTOR_KEY_CONTROL,
892                                                 target_container);
893
894         /* It is ensured by skb_flow_dissector_init() that basic key will
895          * be always present.
896          */
897         key_basic = skb_flow_dissector_target(flow_dissector,
898                                               FLOW_DISSECTOR_KEY_BASIC,
899                                               target_container);
900
901         if (skb) {
902                 if (!net) {
903                         if (skb->dev)
904                                 net = dev_net(skb->dev);
905                         else if (skb->sk)
906                                 net = sock_net(skb->sk);
907                 }
908         }
909
910         WARN_ON_ONCE(!net);
911         if (net) {
912                 rcu_read_lock();
913                 attached = rcu_dereference(net->flow_dissector_prog);
914
915                 if (attached) {
916                         struct bpf_flow_keys flow_keys;
917                         struct bpf_flow_dissector ctx = {
918                                 .flow_keys = &flow_keys,
919                                 .data = data,
920                                 .data_end = data + hlen,
921                         };
922                         __be16 n_proto = proto;
923
924                         if (skb) {
925                                 ctx.skb = skb;
926                                 /* we can't use 'proto' in the skb case
927                                  * because it might be set to skb->vlan_proto
928                                  * which has been pulled from the data
929                                  */
930                                 n_proto = skb->protocol;
931                         }
932
933                         ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
934                                                hlen, flags);
935                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
936                                                  target_container);
937                         rcu_read_unlock();
938                         return ret;
939                 }
940                 rcu_read_unlock();
941         }
942
943         if (dissector_uses_key(flow_dissector,
944                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
945                 struct ethhdr *eth = eth_hdr(skb);
946                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
947
948                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
949                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
950                                                           target_container);
951                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
952         }
953
954 proto_again:
955         fdret = FLOW_DISSECT_RET_CONTINUE;
956
957         switch (proto) {
958         case htons(ETH_P_IP): {
959                 const struct iphdr *iph;
960                 struct iphdr _iph;
961
962                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
963                 if (!iph || iph->ihl < 5) {
964                         fdret = FLOW_DISSECT_RET_OUT_BAD;
965                         break;
966                 }
967
968                 nhoff += iph->ihl * 4;
969
970                 ip_proto = iph->protocol;
971
972                 if (dissector_uses_key(flow_dissector,
973                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
974                         key_addrs = skb_flow_dissector_target(flow_dissector,
975                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
976                                                               target_container);
977
978                         memcpy(&key_addrs->v4addrs, &iph->saddr,
979                                sizeof(key_addrs->v4addrs));
980                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
981                 }
982
983                 if (ip_is_fragment(iph)) {
984                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
985
986                         if (iph->frag_off & htons(IP_OFFSET)) {
987                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
988                                 break;
989                         } else {
990                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
991                                 if (!(flags &
992                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
993                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
994                                         break;
995                                 }
996                         }
997                 }
998
999                 __skb_flow_dissect_ipv4(skb, flow_dissector,
1000                                         target_container, data, iph);
1001
1002                 break;
1003         }
1004         case htons(ETH_P_IPV6): {
1005                 const struct ipv6hdr *iph;
1006                 struct ipv6hdr _iph;
1007
1008                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1009                 if (!iph) {
1010                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1011                         break;
1012                 }
1013
1014                 ip_proto = iph->nexthdr;
1015                 nhoff += sizeof(struct ipv6hdr);
1016
1017                 if (dissector_uses_key(flow_dissector,
1018                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1019                         key_addrs = skb_flow_dissector_target(flow_dissector,
1020                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1021                                                               target_container);
1022
1023                         memcpy(&key_addrs->v6addrs, &iph->saddr,
1024                                sizeof(key_addrs->v6addrs));
1025                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1026                 }
1027
1028                 if ((dissector_uses_key(flow_dissector,
1029                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1030                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1031                     ip6_flowlabel(iph)) {
1032                         __be32 flow_label = ip6_flowlabel(iph);
1033
1034                         if (dissector_uses_key(flow_dissector,
1035                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1036                                 key_tags = skb_flow_dissector_target(flow_dissector,
1037                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1038                                                                      target_container);
1039                                 key_tags->flow_label = ntohl(flow_label);
1040                         }
1041                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1042                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1043                                 break;
1044                         }
1045                 }
1046
1047                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1048                                         target_container, data, iph);
1049
1050                 break;
1051         }
1052         case htons(ETH_P_8021AD):
1053         case htons(ETH_P_8021Q): {
1054                 const struct vlan_hdr *vlan = NULL;
1055                 struct vlan_hdr _vlan;
1056                 __be16 saved_vlan_tpid = proto;
1057
1058                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1059                     skb && skb_vlan_tag_present(skb)) {
1060                         proto = skb->protocol;
1061                 } else {
1062                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1063                                                     data, hlen, &_vlan);
1064                         if (!vlan) {
1065                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1066                                 break;
1067                         }
1068
1069                         proto = vlan->h_vlan_encapsulated_proto;
1070                         nhoff += sizeof(*vlan);
1071                 }
1072
1073                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1074                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1075                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1076                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1077                 } else {
1078                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1079                         break;
1080                 }
1081
1082                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1083                         key_vlan = skb_flow_dissector_target(flow_dissector,
1084                                                              dissector_vlan,
1085                                                              target_container);
1086
1087                         if (!vlan) {
1088                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1089                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1090                         } else {
1091                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1092                                         VLAN_VID_MASK;
1093                                 key_vlan->vlan_priority =
1094                                         (ntohs(vlan->h_vlan_TCI) &
1095                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1096                         }
1097                         key_vlan->vlan_tpid = saved_vlan_tpid;
1098                 }
1099
1100                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1101                 break;
1102         }
1103         case htons(ETH_P_PPP_SES): {
1104                 struct {
1105                         struct pppoe_hdr hdr;
1106                         __be16 proto;
1107                 } *hdr, _hdr;
1108                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1109                 if (!hdr) {
1110                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1111                         break;
1112                 }
1113
1114                 proto = hdr->proto;
1115                 nhoff += PPPOE_SES_HLEN;
1116                 switch (proto) {
1117                 case htons(PPP_IP):
1118                         proto = htons(ETH_P_IP);
1119                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1120                         break;
1121                 case htons(PPP_IPV6):
1122                         proto = htons(ETH_P_IPV6);
1123                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1124                         break;
1125                 default:
1126                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1127                         break;
1128                 }
1129                 break;
1130         }
1131         case htons(ETH_P_TIPC): {
1132                 struct tipc_basic_hdr *hdr, _hdr;
1133
1134                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1135                                            data, hlen, &_hdr);
1136                 if (!hdr) {
1137                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1138                         break;
1139                 }
1140
1141                 if (dissector_uses_key(flow_dissector,
1142                                        FLOW_DISSECTOR_KEY_TIPC)) {
1143                         key_addrs = skb_flow_dissector_target(flow_dissector,
1144                                                               FLOW_DISSECTOR_KEY_TIPC,
1145                                                               target_container);
1146                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1147                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1148                 }
1149                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1150                 break;
1151         }
1152
1153         case htons(ETH_P_MPLS_UC):
1154         case htons(ETH_P_MPLS_MC):
1155                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1156                                                 target_container, data,
1157                                                 nhoff, hlen);
1158                 break;
1159         case htons(ETH_P_FCOE):
1160                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1161                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1162                         break;
1163                 }
1164
1165                 nhoff += FCOE_HEADER_LEN;
1166                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1167                 break;
1168
1169         case htons(ETH_P_ARP):
1170         case htons(ETH_P_RARP):
1171                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1172                                                target_container, data,
1173                                                nhoff, hlen);
1174                 break;
1175
1176         case htons(ETH_P_BATMAN):
1177                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1178                                                   &proto, &nhoff, hlen, flags);
1179                 break;
1180
1181         default:
1182                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1183                 break;
1184         }
1185
1186         /* Process result of proto processing */
1187         switch (fdret) {
1188         case FLOW_DISSECT_RET_OUT_GOOD:
1189                 goto out_good;
1190         case FLOW_DISSECT_RET_PROTO_AGAIN:
1191                 if (skb_flow_dissect_allowed(&num_hdrs))
1192                         goto proto_again;
1193                 goto out_good;
1194         case FLOW_DISSECT_RET_CONTINUE:
1195         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1196                 break;
1197         case FLOW_DISSECT_RET_OUT_BAD:
1198         default:
1199                 goto out_bad;
1200         }
1201
1202 ip_proto_again:
1203         fdret = FLOW_DISSECT_RET_CONTINUE;
1204
1205         switch (ip_proto) {
1206         case IPPROTO_GRE:
1207                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1208                                                target_container, data,
1209                                                &proto, &nhoff, &hlen, flags);
1210                 break;
1211
1212         case NEXTHDR_HOP:
1213         case NEXTHDR_ROUTING:
1214         case NEXTHDR_DEST: {
1215                 u8 _opthdr[2], *opthdr;
1216
1217                 if (proto != htons(ETH_P_IPV6))
1218                         break;
1219
1220                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1221                                               data, hlen, &_opthdr);
1222                 if (!opthdr) {
1223                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1224                         break;
1225                 }
1226
1227                 ip_proto = opthdr[0];
1228                 nhoff += (opthdr[1] + 1) << 3;
1229
1230                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1231                 break;
1232         }
1233         case NEXTHDR_FRAGMENT: {
1234                 struct frag_hdr _fh, *fh;
1235
1236                 if (proto != htons(ETH_P_IPV6))
1237                         break;
1238
1239                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1240                                           data, hlen, &_fh);
1241
1242                 if (!fh) {
1243                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1244                         break;
1245                 }
1246
1247                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1248
1249                 nhoff += sizeof(_fh);
1250                 ip_proto = fh->nexthdr;
1251
1252                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1253                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1254                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1255                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1256                                 break;
1257                         }
1258                 }
1259
1260                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1261                 break;
1262         }
1263         case IPPROTO_IPIP:
1264                 proto = htons(ETH_P_IP);
1265
1266                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1267                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1268                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1269                         break;
1270                 }
1271
1272                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1273                 break;
1274
1275         case IPPROTO_IPV6:
1276                 proto = htons(ETH_P_IPV6);
1277
1278                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1279                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1280                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1281                         break;
1282                 }
1283
1284                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1285                 break;
1286
1287
1288         case IPPROTO_MPLS:
1289                 proto = htons(ETH_P_MPLS_UC);
1290                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1291                 break;
1292
1293         case IPPROTO_TCP:
1294                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1295                                        data, nhoff, hlen);
1296                 break;
1297
1298         default:
1299                 break;
1300         }
1301
1302         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1303             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1304                 key_ports = skb_flow_dissector_target(flow_dissector,
1305                                                       FLOW_DISSECTOR_KEY_PORTS,
1306                                                       target_container);
1307                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1308                                                         data, hlen);
1309         }
1310
1311         if (dissector_uses_key(flow_dissector,
1312                                FLOW_DISSECTOR_KEY_ICMP)) {
1313                 key_icmp = skb_flow_dissector_target(flow_dissector,
1314                                                      FLOW_DISSECTOR_KEY_ICMP,
1315                                                      target_container);
1316                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1317         }
1318
1319         /* Process result of IP proto processing */
1320         switch (fdret) {
1321         case FLOW_DISSECT_RET_PROTO_AGAIN:
1322                 if (skb_flow_dissect_allowed(&num_hdrs))
1323                         goto proto_again;
1324                 break;
1325         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1326                 if (skb_flow_dissect_allowed(&num_hdrs))
1327                         goto ip_proto_again;
1328                 break;
1329         case FLOW_DISSECT_RET_OUT_GOOD:
1330         case FLOW_DISSECT_RET_CONTINUE:
1331                 break;
1332         case FLOW_DISSECT_RET_OUT_BAD:
1333         default:
1334                 goto out_bad;
1335         }
1336
1337 out_good:
1338         ret = true;
1339
1340 out:
1341         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1342         key_basic->n_proto = proto;
1343         key_basic->ip_proto = ip_proto;
1344
1345         return ret;
1346
1347 out_bad:
1348         ret = false;
1349         goto out;
1350 }
1351 EXPORT_SYMBOL(__skb_flow_dissect);
1352
1353 static u32 hashrnd __read_mostly;
1354 static __always_inline void __flow_hash_secret_init(void)
1355 {
1356         net_get_random_once(&hashrnd, sizeof(hashrnd));
1357 }
1358
1359 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1360                                              u32 keyval)
1361 {
1362         return jhash2(words, length, keyval);
1363 }
1364
1365 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1366 {
1367         const void *p = flow;
1368
1369         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1370         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1371 }
1372
1373 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1374 {
1375         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1376         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1377         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1378                      sizeof(*flow) - sizeof(flow->addrs));
1379
1380         switch (flow->control.addr_type) {
1381         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1382                 diff -= sizeof(flow->addrs.v4addrs);
1383                 break;
1384         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1385                 diff -= sizeof(flow->addrs.v6addrs);
1386                 break;
1387         case FLOW_DISSECTOR_KEY_TIPC:
1388                 diff -= sizeof(flow->addrs.tipckey);
1389                 break;
1390         }
1391         return (sizeof(*flow) - diff) / sizeof(u32);
1392 }
1393
1394 __be32 flow_get_u32_src(const struct flow_keys *flow)
1395 {
1396         switch (flow->control.addr_type) {
1397         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1398                 return flow->addrs.v4addrs.src;
1399         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1400                 return (__force __be32)ipv6_addr_hash(
1401                         &flow->addrs.v6addrs.src);
1402         case FLOW_DISSECTOR_KEY_TIPC:
1403                 return flow->addrs.tipckey.key;
1404         default:
1405                 return 0;
1406         }
1407 }
1408 EXPORT_SYMBOL(flow_get_u32_src);
1409
1410 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1411 {
1412         switch (flow->control.addr_type) {
1413         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1414                 return flow->addrs.v4addrs.dst;
1415         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1416                 return (__force __be32)ipv6_addr_hash(
1417                         &flow->addrs.v6addrs.dst);
1418         default:
1419                 return 0;
1420         }
1421 }
1422 EXPORT_SYMBOL(flow_get_u32_dst);
1423
1424 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1425 {
1426         int addr_diff, i;
1427
1428         switch (keys->control.addr_type) {
1429         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1430                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1431                             (__force u32)keys->addrs.v4addrs.src;
1432                 if ((addr_diff < 0) ||
1433                     (addr_diff == 0 &&
1434                      ((__force u16)keys->ports.dst <
1435                       (__force u16)keys->ports.src))) {
1436                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1437                         swap(keys->ports.src, keys->ports.dst);
1438                 }
1439                 break;
1440         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1441                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1442                                    &keys->addrs.v6addrs.src,
1443                                    sizeof(keys->addrs.v6addrs.dst));
1444                 if ((addr_diff < 0) ||
1445                     (addr_diff == 0 &&
1446                      ((__force u16)keys->ports.dst <
1447                       (__force u16)keys->ports.src))) {
1448                         for (i = 0; i < 4; i++)
1449                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1450                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1451                         swap(keys->ports.src, keys->ports.dst);
1452                 }
1453                 break;
1454         }
1455 }
1456
1457 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1458 {
1459         u32 hash;
1460
1461         __flow_hash_consistentify(keys);
1462
1463         hash = __flow_hash_words(flow_keys_hash_start(keys),
1464                                  flow_keys_hash_length(keys), keyval);
1465         if (!hash)
1466                 hash = 1;
1467
1468         return hash;
1469 }
1470
1471 u32 flow_hash_from_keys(struct flow_keys *keys)
1472 {
1473         __flow_hash_secret_init();
1474         return __flow_hash_from_keys(keys, hashrnd);
1475 }
1476 EXPORT_SYMBOL(flow_hash_from_keys);
1477
1478 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1479                                   struct flow_keys *keys, u32 keyval)
1480 {
1481         skb_flow_dissect_flow_keys(skb, keys,
1482                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1483
1484         return __flow_hash_from_keys(keys, keyval);
1485 }
1486
1487 struct _flow_keys_digest_data {
1488         __be16  n_proto;
1489         u8      ip_proto;
1490         u8      padding;
1491         __be32  ports;
1492         __be32  src;
1493         __be32  dst;
1494 };
1495
1496 void make_flow_keys_digest(struct flow_keys_digest *digest,
1497                            const struct flow_keys *flow)
1498 {
1499         struct _flow_keys_digest_data *data =
1500             (struct _flow_keys_digest_data *)digest;
1501
1502         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1503
1504         memset(digest, 0, sizeof(*digest));
1505
1506         data->n_proto = flow->basic.n_proto;
1507         data->ip_proto = flow->basic.ip_proto;
1508         data->ports = flow->ports.ports;
1509         data->src = flow->addrs.v4addrs.src;
1510         data->dst = flow->addrs.v4addrs.dst;
1511 }
1512 EXPORT_SYMBOL(make_flow_keys_digest);
1513
1514 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1515
1516 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1517 {
1518         struct flow_keys keys;
1519
1520         __flow_hash_secret_init();
1521
1522         memset(&keys, 0, sizeof(keys));
1523         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1524                            &keys, NULL, 0, 0, 0,
1525                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1526
1527         return __flow_hash_from_keys(&keys, hashrnd);
1528 }
1529 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1530
1531 /**
1532  * __skb_get_hash: calculate a flow hash
1533  * @skb: sk_buff to calculate flow hash from
1534  *
1535  * This function calculates a flow hash based on src/dst addresses
1536  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1537  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1538  * if hash is a canonical 4-tuple hash over transport ports.
1539  */
1540 void __skb_get_hash(struct sk_buff *skb)
1541 {
1542         struct flow_keys keys;
1543         u32 hash;
1544
1545         __flow_hash_secret_init();
1546
1547         hash = ___skb_get_hash(skb, &keys, hashrnd);
1548
1549         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1550 }
1551 EXPORT_SYMBOL(__skb_get_hash);
1552
1553 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1554 {
1555         struct flow_keys keys;
1556
1557         return ___skb_get_hash(skb, &keys, perturb);
1558 }
1559 EXPORT_SYMBOL(skb_get_hash_perturb);
1560
1561 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1562                    const struct flow_keys_basic *keys, int hlen)
1563 {
1564         u32 poff = keys->control.thoff;
1565
1566         /* skip L4 headers for fragments after the first */
1567         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1568             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1569                 return poff;
1570
1571         switch (keys->basic.ip_proto) {
1572         case IPPROTO_TCP: {
1573                 /* access doff as u8 to avoid unaligned access */
1574                 const u8 *doff;
1575                 u8 _doff;
1576
1577                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1578                                             data, hlen, &_doff);
1579                 if (!doff)
1580                         return poff;
1581
1582                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1583                 break;
1584         }
1585         case IPPROTO_UDP:
1586         case IPPROTO_UDPLITE:
1587                 poff += sizeof(struct udphdr);
1588                 break;
1589         /* For the rest, we do not really care about header
1590          * extensions at this point for now.
1591          */
1592         case IPPROTO_ICMP:
1593                 poff += sizeof(struct icmphdr);
1594                 break;
1595         case IPPROTO_ICMPV6:
1596                 poff += sizeof(struct icmp6hdr);
1597                 break;
1598         case IPPROTO_IGMP:
1599                 poff += sizeof(struct igmphdr);
1600                 break;
1601         case IPPROTO_DCCP:
1602                 poff += sizeof(struct dccp_hdr);
1603                 break;
1604         case IPPROTO_SCTP:
1605                 poff += sizeof(struct sctphdr);
1606                 break;
1607         }
1608
1609         return poff;
1610 }
1611
1612 /**
1613  * skb_get_poff - get the offset to the payload
1614  * @skb: sk_buff to get the payload offset from
1615  *
1616  * The function will get the offset to the payload as far as it could
1617  * be dissected.  The main user is currently BPF, so that we can dynamically
1618  * truncate packets without needing to push actual payload to the user
1619  * space and can analyze headers only, instead.
1620  */
1621 u32 skb_get_poff(const struct sk_buff *skb)
1622 {
1623         struct flow_keys_basic keys;
1624
1625         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1626                                               NULL, 0, 0, 0, 0))
1627                 return 0;
1628
1629         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1630 }
1631
1632 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1633 {
1634         memset(keys, 0, sizeof(*keys));
1635
1636         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1637             sizeof(keys->addrs.v6addrs.src));
1638         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1639             sizeof(keys->addrs.v6addrs.dst));
1640         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1641         keys->ports.src = fl6->fl6_sport;
1642         keys->ports.dst = fl6->fl6_dport;
1643         keys->keyid.keyid = fl6->fl6_gre_key;
1644         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1645         keys->basic.ip_proto = fl6->flowi6_proto;
1646
1647         return flow_hash_from_keys(keys);
1648 }
1649 EXPORT_SYMBOL(__get_hash_from_flowi6);
1650
1651 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1652         {
1653                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1654                 .offset = offsetof(struct flow_keys, control),
1655         },
1656         {
1657                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1658                 .offset = offsetof(struct flow_keys, basic),
1659         },
1660         {
1661                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1662                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1663         },
1664         {
1665                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1666                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1667         },
1668         {
1669                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1670                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1671         },
1672         {
1673                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1674                 .offset = offsetof(struct flow_keys, ports),
1675         },
1676         {
1677                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1678                 .offset = offsetof(struct flow_keys, vlan),
1679         },
1680         {
1681                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1682                 .offset = offsetof(struct flow_keys, tags),
1683         },
1684         {
1685                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1686                 .offset = offsetof(struct flow_keys, keyid),
1687         },
1688 };
1689
1690 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1691         {
1692                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1693                 .offset = offsetof(struct flow_keys, control),
1694         },
1695         {
1696                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1697                 .offset = offsetof(struct flow_keys, basic),
1698         },
1699         {
1700                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1701                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1702         },
1703         {
1704                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1705                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1706         },
1707         {
1708                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1709                 .offset = offsetof(struct flow_keys, ports),
1710         },
1711 };
1712
1713 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1714         {
1715                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1716                 .offset = offsetof(struct flow_keys, control),
1717         },
1718         {
1719                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1720                 .offset = offsetof(struct flow_keys, basic),
1721         },
1722 };
1723
1724 struct flow_dissector flow_keys_dissector __read_mostly;
1725 EXPORT_SYMBOL(flow_keys_dissector);
1726
1727 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1728 EXPORT_SYMBOL(flow_keys_basic_dissector);
1729
1730 static int __init init_default_flow_dissectors(void)
1731 {
1732         skb_flow_dissector_init(&flow_keys_dissector,
1733                                 flow_keys_dissector_keys,
1734                                 ARRAY_SIZE(flow_keys_dissector_keys));
1735         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1736                                 flow_keys_dissector_symmetric_keys,
1737                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1738         skb_flow_dissector_init(&flow_keys_basic_dissector,
1739                                 flow_keys_basic_dissector_keys,
1740                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1741         return 0;
1742 }
1743
1744 core_initcall(init_default_flow_dissectors);