bpf/flow_dissector: pass input flags to BPF flow dissector program
[linux-2.6-microblaze.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         bpf_prog_put(attached);
146         RCU_INIT_POINTER(net->flow_dissector_prog, NULL);
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
741         key_control = skb_flow_dissector_target(flow_dissector,
742                                                 FLOW_DISSECTOR_KEY_CONTROL,
743                                                 target_container);
744         key_control->thoff = flow_keys->thoff;
745         if (flow_keys->is_frag)
746                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
747         if (flow_keys->is_first_frag)
748                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
749         if (flow_keys->is_encap)
750                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
751
752         key_basic = skb_flow_dissector_target(flow_dissector,
753                                               FLOW_DISSECTOR_KEY_BASIC,
754                                               target_container);
755         key_basic->n_proto = flow_keys->n_proto;
756         key_basic->ip_proto = flow_keys->ip_proto;
757
758         if (flow_keys->addr_proto == ETH_P_IP &&
759             dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
760                 key_addrs = skb_flow_dissector_target(flow_dissector,
761                                                       FLOW_DISSECTOR_KEY_IPV4_ADDRS,
762                                                       target_container);
763                 key_addrs->v4addrs.src = flow_keys->ipv4_src;
764                 key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
765                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
766         } else if (flow_keys->addr_proto == ETH_P_IPV6 &&
767                    dissector_uses_key(flow_dissector,
768                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
769                 key_addrs = skb_flow_dissector_target(flow_dissector,
770                                                       FLOW_DISSECTOR_KEY_IPV6_ADDRS,
771                                                       target_container);
772                 memcpy(&key_addrs->v6addrs, &flow_keys->ipv6_src,
773                        sizeof(key_addrs->v6addrs));
774                 key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
775         }
776
777         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS)) {
778                 key_ports = skb_flow_dissector_target(flow_dissector,
779                                                       FLOW_DISSECTOR_KEY_PORTS,
780                                                       target_container);
781                 key_ports->src = flow_keys->sport;
782                 key_ports->dst = flow_keys->dport;
783         }
784 }
785
786 bool bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
787                       __be16 proto, int nhoff, int hlen, unsigned int flags)
788 {
789         struct bpf_flow_keys *flow_keys = ctx->flow_keys;
790         u32 result;
791
792         /* Pass parameters to the BPF program */
793         memset(flow_keys, 0, sizeof(*flow_keys));
794         flow_keys->n_proto = proto;
795         flow_keys->nhoff = nhoff;
796         flow_keys->thoff = flow_keys->nhoff;
797
798         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
799                      (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
800         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
801                      (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
802         BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
803                      (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
804         flow_keys->flags = flags;
805
806         preempt_disable();
807         result = BPF_PROG_RUN(prog, ctx);
808         preempt_enable();
809
810         flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
811         flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
812                                    flow_keys->nhoff, hlen);
813
814         return result == BPF_OK;
815 }
816
817 /**
818  * __skb_flow_dissect - extract the flow_keys struct and return it
819  * @net: associated network namespace, derived from @skb if NULL
820  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
821  * @flow_dissector: list of keys to dissect
822  * @target_container: target structure to put dissected values into
823  * @data: raw buffer pointer to the packet, if NULL use skb->data
824  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
825  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
826  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
827  * @flags: flags that control the dissection process, e.g.
828  *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
829  *
830  * The function will try to retrieve individual keys into target specified
831  * by flow_dissector from either the skbuff or a raw buffer specified by the
832  * rest parameters.
833  *
834  * Caller must take care of zeroing target container memory.
835  */
836 bool __skb_flow_dissect(const struct net *net,
837                         const struct sk_buff *skb,
838                         struct flow_dissector *flow_dissector,
839                         void *target_container,
840                         void *data, __be16 proto, int nhoff, int hlen,
841                         unsigned int flags)
842 {
843         struct flow_dissector_key_control *key_control;
844         struct flow_dissector_key_basic *key_basic;
845         struct flow_dissector_key_addrs *key_addrs;
846         struct flow_dissector_key_ports *key_ports;
847         struct flow_dissector_key_icmp *key_icmp;
848         struct flow_dissector_key_tags *key_tags;
849         struct flow_dissector_key_vlan *key_vlan;
850         struct bpf_prog *attached = NULL;
851         enum flow_dissect_ret fdret;
852         enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
853         int num_hdrs = 0;
854         u8 ip_proto = 0;
855         bool ret;
856
857         if (!data) {
858                 data = skb->data;
859                 proto = skb_vlan_tag_present(skb) ?
860                          skb->vlan_proto : skb->protocol;
861                 nhoff = skb_network_offset(skb);
862                 hlen = skb_headlen(skb);
863 #if IS_ENABLED(CONFIG_NET_DSA)
864                 if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
865                         const struct dsa_device_ops *ops;
866                         int offset;
867
868                         ops = skb->dev->dsa_ptr->tag_ops;
869                         if (ops->flow_dissect &&
870                             !ops->flow_dissect(skb, &proto, &offset)) {
871                                 hlen -= offset;
872                                 nhoff += offset;
873                         }
874                 }
875 #endif
876         }
877
878         /* It is ensured by skb_flow_dissector_init() that control key will
879          * be always present.
880          */
881         key_control = skb_flow_dissector_target(flow_dissector,
882                                                 FLOW_DISSECTOR_KEY_CONTROL,
883                                                 target_container);
884
885         /* It is ensured by skb_flow_dissector_init() that basic key will
886          * be always present.
887          */
888         key_basic = skb_flow_dissector_target(flow_dissector,
889                                               FLOW_DISSECTOR_KEY_BASIC,
890                                               target_container);
891
892         if (skb) {
893                 if (!net) {
894                         if (skb->dev)
895                                 net = dev_net(skb->dev);
896                         else if (skb->sk)
897                                 net = sock_net(skb->sk);
898                 }
899         }
900
901         WARN_ON_ONCE(!net);
902         if (net) {
903                 rcu_read_lock();
904                 attached = rcu_dereference(net->flow_dissector_prog);
905
906                 if (attached) {
907                         struct bpf_flow_keys flow_keys;
908                         struct bpf_flow_dissector ctx = {
909                                 .flow_keys = &flow_keys,
910                                 .data = data,
911                                 .data_end = data + hlen,
912                         };
913                         __be16 n_proto = proto;
914
915                         if (skb) {
916                                 ctx.skb = skb;
917                                 /* we can't use 'proto' in the skb case
918                                  * because it might be set to skb->vlan_proto
919                                  * which has been pulled from the data
920                                  */
921                                 n_proto = skb->protocol;
922                         }
923
924                         ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
925                                                hlen, flags);
926                         __skb_flow_bpf_to_target(&flow_keys, flow_dissector,
927                                                  target_container);
928                         rcu_read_unlock();
929                         return ret;
930                 }
931                 rcu_read_unlock();
932         }
933
934         if (dissector_uses_key(flow_dissector,
935                                FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
936                 struct ethhdr *eth = eth_hdr(skb);
937                 struct flow_dissector_key_eth_addrs *key_eth_addrs;
938
939                 key_eth_addrs = skb_flow_dissector_target(flow_dissector,
940                                                           FLOW_DISSECTOR_KEY_ETH_ADDRS,
941                                                           target_container);
942                 memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
943         }
944
945 proto_again:
946         fdret = FLOW_DISSECT_RET_CONTINUE;
947
948         switch (proto) {
949         case htons(ETH_P_IP): {
950                 const struct iphdr *iph;
951                 struct iphdr _iph;
952
953                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
954                 if (!iph || iph->ihl < 5) {
955                         fdret = FLOW_DISSECT_RET_OUT_BAD;
956                         break;
957                 }
958
959                 nhoff += iph->ihl * 4;
960
961                 ip_proto = iph->protocol;
962
963                 if (dissector_uses_key(flow_dissector,
964                                        FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
965                         key_addrs = skb_flow_dissector_target(flow_dissector,
966                                                               FLOW_DISSECTOR_KEY_IPV4_ADDRS,
967                                                               target_container);
968
969                         memcpy(&key_addrs->v4addrs, &iph->saddr,
970                                sizeof(key_addrs->v4addrs));
971                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
972                 }
973
974                 if (ip_is_fragment(iph)) {
975                         key_control->flags |= FLOW_DIS_IS_FRAGMENT;
976
977                         if (iph->frag_off & htons(IP_OFFSET)) {
978                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
979                                 break;
980                         } else {
981                                 key_control->flags |= FLOW_DIS_FIRST_FRAG;
982                                 if (!(flags &
983                                       FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
984                                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
985                                         break;
986                                 }
987                         }
988                 }
989
990                 __skb_flow_dissect_ipv4(skb, flow_dissector,
991                                         target_container, data, iph);
992
993                 break;
994         }
995         case htons(ETH_P_IPV6): {
996                 const struct ipv6hdr *iph;
997                 struct ipv6hdr _iph;
998
999                 iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1000                 if (!iph) {
1001                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1002                         break;
1003                 }
1004
1005                 ip_proto = iph->nexthdr;
1006                 nhoff += sizeof(struct ipv6hdr);
1007
1008                 if (dissector_uses_key(flow_dissector,
1009                                        FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1010                         key_addrs = skb_flow_dissector_target(flow_dissector,
1011                                                               FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1012                                                               target_container);
1013
1014                         memcpy(&key_addrs->v6addrs, &iph->saddr,
1015                                sizeof(key_addrs->v6addrs));
1016                         key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1017                 }
1018
1019                 if ((dissector_uses_key(flow_dissector,
1020                                         FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1021                      (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1022                     ip6_flowlabel(iph)) {
1023                         __be32 flow_label = ip6_flowlabel(iph);
1024
1025                         if (dissector_uses_key(flow_dissector,
1026                                                FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1027                                 key_tags = skb_flow_dissector_target(flow_dissector,
1028                                                                      FLOW_DISSECTOR_KEY_FLOW_LABEL,
1029                                                                      target_container);
1030                                 key_tags->flow_label = ntohl(flow_label);
1031                         }
1032                         if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1033                                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1034                                 break;
1035                         }
1036                 }
1037
1038                 __skb_flow_dissect_ipv6(skb, flow_dissector,
1039                                         target_container, data, iph);
1040
1041                 break;
1042         }
1043         case htons(ETH_P_8021AD):
1044         case htons(ETH_P_8021Q): {
1045                 const struct vlan_hdr *vlan = NULL;
1046                 struct vlan_hdr _vlan;
1047                 __be16 saved_vlan_tpid = proto;
1048
1049                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1050                     skb && skb_vlan_tag_present(skb)) {
1051                         proto = skb->protocol;
1052                 } else {
1053                         vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1054                                                     data, hlen, &_vlan);
1055                         if (!vlan) {
1056                                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1057                                 break;
1058                         }
1059
1060                         proto = vlan->h_vlan_encapsulated_proto;
1061                         nhoff += sizeof(*vlan);
1062                 }
1063
1064                 if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1065                         dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1066                 } else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1067                         dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1068                 } else {
1069                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1070                         break;
1071                 }
1072
1073                 if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1074                         key_vlan = skb_flow_dissector_target(flow_dissector,
1075                                                              dissector_vlan,
1076                                                              target_container);
1077
1078                         if (!vlan) {
1079                                 key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1080                                 key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1081                         } else {
1082                                 key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1083                                         VLAN_VID_MASK;
1084                                 key_vlan->vlan_priority =
1085                                         (ntohs(vlan->h_vlan_TCI) &
1086                                          VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1087                         }
1088                         key_vlan->vlan_tpid = saved_vlan_tpid;
1089                 }
1090
1091                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1092                 break;
1093         }
1094         case htons(ETH_P_PPP_SES): {
1095                 struct {
1096                         struct pppoe_hdr hdr;
1097                         __be16 proto;
1098                 } *hdr, _hdr;
1099                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1100                 if (!hdr) {
1101                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1102                         break;
1103                 }
1104
1105                 proto = hdr->proto;
1106                 nhoff += PPPOE_SES_HLEN;
1107                 switch (proto) {
1108                 case htons(PPP_IP):
1109                         proto = htons(ETH_P_IP);
1110                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1111                         break;
1112                 case htons(PPP_IPV6):
1113                         proto = htons(ETH_P_IPV6);
1114                         fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1115                         break;
1116                 default:
1117                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1118                         break;
1119                 }
1120                 break;
1121         }
1122         case htons(ETH_P_TIPC): {
1123                 struct tipc_basic_hdr *hdr, _hdr;
1124
1125                 hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1126                                            data, hlen, &_hdr);
1127                 if (!hdr) {
1128                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1129                         break;
1130                 }
1131
1132                 if (dissector_uses_key(flow_dissector,
1133                                        FLOW_DISSECTOR_KEY_TIPC)) {
1134                         key_addrs = skb_flow_dissector_target(flow_dissector,
1135                                                               FLOW_DISSECTOR_KEY_TIPC,
1136                                                               target_container);
1137                         key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1138                         key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1139                 }
1140                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1141                 break;
1142         }
1143
1144         case htons(ETH_P_MPLS_UC):
1145         case htons(ETH_P_MPLS_MC):
1146                 fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1147                                                 target_container, data,
1148                                                 nhoff, hlen);
1149                 break;
1150         case htons(ETH_P_FCOE):
1151                 if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1152                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1153                         break;
1154                 }
1155
1156                 nhoff += FCOE_HEADER_LEN;
1157                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1158                 break;
1159
1160         case htons(ETH_P_ARP):
1161         case htons(ETH_P_RARP):
1162                 fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1163                                                target_container, data,
1164                                                nhoff, hlen);
1165                 break;
1166
1167         case htons(ETH_P_BATMAN):
1168                 fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1169                                                   &proto, &nhoff, hlen, flags);
1170                 break;
1171
1172         default:
1173                 fdret = FLOW_DISSECT_RET_OUT_BAD;
1174                 break;
1175         }
1176
1177         /* Process result of proto processing */
1178         switch (fdret) {
1179         case FLOW_DISSECT_RET_OUT_GOOD:
1180                 goto out_good;
1181         case FLOW_DISSECT_RET_PROTO_AGAIN:
1182                 if (skb_flow_dissect_allowed(&num_hdrs))
1183                         goto proto_again;
1184                 goto out_good;
1185         case FLOW_DISSECT_RET_CONTINUE:
1186         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1187                 break;
1188         case FLOW_DISSECT_RET_OUT_BAD:
1189         default:
1190                 goto out_bad;
1191         }
1192
1193 ip_proto_again:
1194         fdret = FLOW_DISSECT_RET_CONTINUE;
1195
1196         switch (ip_proto) {
1197         case IPPROTO_GRE:
1198                 fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1199                                                target_container, data,
1200                                                &proto, &nhoff, &hlen, flags);
1201                 break;
1202
1203         case NEXTHDR_HOP:
1204         case NEXTHDR_ROUTING:
1205         case NEXTHDR_DEST: {
1206                 u8 _opthdr[2], *opthdr;
1207
1208                 if (proto != htons(ETH_P_IPV6))
1209                         break;
1210
1211                 opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1212                                               data, hlen, &_opthdr);
1213                 if (!opthdr) {
1214                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1215                         break;
1216                 }
1217
1218                 ip_proto = opthdr[0];
1219                 nhoff += (opthdr[1] + 1) << 3;
1220
1221                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1222                 break;
1223         }
1224         case NEXTHDR_FRAGMENT: {
1225                 struct frag_hdr _fh, *fh;
1226
1227                 if (proto != htons(ETH_P_IPV6))
1228                         break;
1229
1230                 fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1231                                           data, hlen, &_fh);
1232
1233                 if (!fh) {
1234                         fdret = FLOW_DISSECT_RET_OUT_BAD;
1235                         break;
1236                 }
1237
1238                 key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1239
1240                 nhoff += sizeof(_fh);
1241                 ip_proto = fh->nexthdr;
1242
1243                 if (!(fh->frag_off & htons(IP6_OFFSET))) {
1244                         key_control->flags |= FLOW_DIS_FIRST_FRAG;
1245                         if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1246                                 fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1247                                 break;
1248                         }
1249                 }
1250
1251                 fdret = FLOW_DISSECT_RET_OUT_GOOD;
1252                 break;
1253         }
1254         case IPPROTO_IPIP:
1255                 proto = htons(ETH_P_IP);
1256
1257                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1258                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1259                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1260                         break;
1261                 }
1262
1263                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1264                 break;
1265
1266         case IPPROTO_IPV6:
1267                 proto = htons(ETH_P_IPV6);
1268
1269                 key_control->flags |= FLOW_DIS_ENCAPSULATION;
1270                 if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1271                         fdret = FLOW_DISSECT_RET_OUT_GOOD;
1272                         break;
1273                 }
1274
1275                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1276                 break;
1277
1278
1279         case IPPROTO_MPLS:
1280                 proto = htons(ETH_P_MPLS_UC);
1281                 fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1282                 break;
1283
1284         case IPPROTO_TCP:
1285                 __skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1286                                        data, nhoff, hlen);
1287                 break;
1288
1289         default:
1290                 break;
1291         }
1292
1293         if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
1294             !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
1295                 key_ports = skb_flow_dissector_target(flow_dissector,
1296                                                       FLOW_DISSECTOR_KEY_PORTS,
1297                                                       target_container);
1298                 key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
1299                                                         data, hlen);
1300         }
1301
1302         if (dissector_uses_key(flow_dissector,
1303                                FLOW_DISSECTOR_KEY_ICMP)) {
1304                 key_icmp = skb_flow_dissector_target(flow_dissector,
1305                                                      FLOW_DISSECTOR_KEY_ICMP,
1306                                                      target_container);
1307                 key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
1308         }
1309
1310         /* Process result of IP proto processing */
1311         switch (fdret) {
1312         case FLOW_DISSECT_RET_PROTO_AGAIN:
1313                 if (skb_flow_dissect_allowed(&num_hdrs))
1314                         goto proto_again;
1315                 break;
1316         case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1317                 if (skb_flow_dissect_allowed(&num_hdrs))
1318                         goto ip_proto_again;
1319                 break;
1320         case FLOW_DISSECT_RET_OUT_GOOD:
1321         case FLOW_DISSECT_RET_CONTINUE:
1322                 break;
1323         case FLOW_DISSECT_RET_OUT_BAD:
1324         default:
1325                 goto out_bad;
1326         }
1327
1328 out_good:
1329         ret = true;
1330
1331 out:
1332         key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1333         key_basic->n_proto = proto;
1334         key_basic->ip_proto = ip_proto;
1335
1336         return ret;
1337
1338 out_bad:
1339         ret = false;
1340         goto out;
1341 }
1342 EXPORT_SYMBOL(__skb_flow_dissect);
1343
1344 static u32 hashrnd __read_mostly;
1345 static __always_inline void __flow_hash_secret_init(void)
1346 {
1347         net_get_random_once(&hashrnd, sizeof(hashrnd));
1348 }
1349
1350 static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
1351                                              u32 keyval)
1352 {
1353         return jhash2(words, length, keyval);
1354 }
1355
1356 static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1357 {
1358         const void *p = flow;
1359
1360         BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1361         return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1362 }
1363
1364 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1365 {
1366         size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1367         BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1368         BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
1369                      sizeof(*flow) - sizeof(flow->addrs));
1370
1371         switch (flow->control.addr_type) {
1372         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1373                 diff -= sizeof(flow->addrs.v4addrs);
1374                 break;
1375         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1376                 diff -= sizeof(flow->addrs.v6addrs);
1377                 break;
1378         case FLOW_DISSECTOR_KEY_TIPC:
1379                 diff -= sizeof(flow->addrs.tipckey);
1380                 break;
1381         }
1382         return (sizeof(*flow) - diff) / sizeof(u32);
1383 }
1384
1385 __be32 flow_get_u32_src(const struct flow_keys *flow)
1386 {
1387         switch (flow->control.addr_type) {
1388         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1389                 return flow->addrs.v4addrs.src;
1390         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1391                 return (__force __be32)ipv6_addr_hash(
1392                         &flow->addrs.v6addrs.src);
1393         case FLOW_DISSECTOR_KEY_TIPC:
1394                 return flow->addrs.tipckey.key;
1395         default:
1396                 return 0;
1397         }
1398 }
1399 EXPORT_SYMBOL(flow_get_u32_src);
1400
1401 __be32 flow_get_u32_dst(const struct flow_keys *flow)
1402 {
1403         switch (flow->control.addr_type) {
1404         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1405                 return flow->addrs.v4addrs.dst;
1406         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1407                 return (__force __be32)ipv6_addr_hash(
1408                         &flow->addrs.v6addrs.dst);
1409         default:
1410                 return 0;
1411         }
1412 }
1413 EXPORT_SYMBOL(flow_get_u32_dst);
1414
1415 static inline void __flow_hash_consistentify(struct flow_keys *keys)
1416 {
1417         int addr_diff, i;
1418
1419         switch (keys->control.addr_type) {
1420         case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1421                 addr_diff = (__force u32)keys->addrs.v4addrs.dst -
1422                             (__force u32)keys->addrs.v4addrs.src;
1423                 if ((addr_diff < 0) ||
1424                     (addr_diff == 0 &&
1425                      ((__force u16)keys->ports.dst <
1426                       (__force u16)keys->ports.src))) {
1427                         swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1428                         swap(keys->ports.src, keys->ports.dst);
1429                 }
1430                 break;
1431         case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1432                 addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1433                                    &keys->addrs.v6addrs.src,
1434                                    sizeof(keys->addrs.v6addrs.dst));
1435                 if ((addr_diff < 0) ||
1436                     (addr_diff == 0 &&
1437                      ((__force u16)keys->ports.dst <
1438                       (__force u16)keys->ports.src))) {
1439                         for (i = 0; i < 4; i++)
1440                                 swap(keys->addrs.v6addrs.src.s6_addr32[i],
1441                                      keys->addrs.v6addrs.dst.s6_addr32[i]);
1442                         swap(keys->ports.src, keys->ports.dst);
1443                 }
1444                 break;
1445         }
1446 }
1447
1448 static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1449 {
1450         u32 hash;
1451
1452         __flow_hash_consistentify(keys);
1453
1454         hash = __flow_hash_words(flow_keys_hash_start(keys),
1455                                  flow_keys_hash_length(keys), keyval);
1456         if (!hash)
1457                 hash = 1;
1458
1459         return hash;
1460 }
1461
1462 u32 flow_hash_from_keys(struct flow_keys *keys)
1463 {
1464         __flow_hash_secret_init();
1465         return __flow_hash_from_keys(keys, hashrnd);
1466 }
1467 EXPORT_SYMBOL(flow_hash_from_keys);
1468
1469 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1470                                   struct flow_keys *keys, u32 keyval)
1471 {
1472         skb_flow_dissect_flow_keys(skb, keys,
1473                                    FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1474
1475         return __flow_hash_from_keys(keys, keyval);
1476 }
1477
1478 struct _flow_keys_digest_data {
1479         __be16  n_proto;
1480         u8      ip_proto;
1481         u8      padding;
1482         __be32  ports;
1483         __be32  src;
1484         __be32  dst;
1485 };
1486
1487 void make_flow_keys_digest(struct flow_keys_digest *digest,
1488                            const struct flow_keys *flow)
1489 {
1490         struct _flow_keys_digest_data *data =
1491             (struct _flow_keys_digest_data *)digest;
1492
1493         BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1494
1495         memset(digest, 0, sizeof(*digest));
1496
1497         data->n_proto = flow->basic.n_proto;
1498         data->ip_proto = flow->basic.ip_proto;
1499         data->ports = flow->ports.ports;
1500         data->src = flow->addrs.v4addrs.src;
1501         data->dst = flow->addrs.v4addrs.dst;
1502 }
1503 EXPORT_SYMBOL(make_flow_keys_digest);
1504
1505 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1506
1507 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1508 {
1509         struct flow_keys keys;
1510
1511         __flow_hash_secret_init();
1512
1513         memset(&keys, 0, sizeof(keys));
1514         __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1515                            &keys, NULL, 0, 0, 0,
1516                            FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1517
1518         return __flow_hash_from_keys(&keys, hashrnd);
1519 }
1520 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1521
1522 /**
1523  * __skb_get_hash: calculate a flow hash
1524  * @skb: sk_buff to calculate flow hash from
1525  *
1526  * This function calculates a flow hash based on src/dst addresses
1527  * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1528  * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1529  * if hash is a canonical 4-tuple hash over transport ports.
1530  */
1531 void __skb_get_hash(struct sk_buff *skb)
1532 {
1533         struct flow_keys keys;
1534         u32 hash;
1535
1536         __flow_hash_secret_init();
1537
1538         hash = ___skb_get_hash(skb, &keys, hashrnd);
1539
1540         __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1541 }
1542 EXPORT_SYMBOL(__skb_get_hash);
1543
1544 __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
1545 {
1546         struct flow_keys keys;
1547
1548         return ___skb_get_hash(skb, &keys, perturb);
1549 }
1550 EXPORT_SYMBOL(skb_get_hash_perturb);
1551
1552 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1553                    const struct flow_keys_basic *keys, int hlen)
1554 {
1555         u32 poff = keys->control.thoff;
1556
1557         /* skip L4 headers for fragments after the first */
1558         if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1559             !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1560                 return poff;
1561
1562         switch (keys->basic.ip_proto) {
1563         case IPPROTO_TCP: {
1564                 /* access doff as u8 to avoid unaligned access */
1565                 const u8 *doff;
1566                 u8 _doff;
1567
1568                 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1569                                             data, hlen, &_doff);
1570                 if (!doff)
1571                         return poff;
1572
1573                 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1574                 break;
1575         }
1576         case IPPROTO_UDP:
1577         case IPPROTO_UDPLITE:
1578                 poff += sizeof(struct udphdr);
1579                 break;
1580         /* For the rest, we do not really care about header
1581          * extensions at this point for now.
1582          */
1583         case IPPROTO_ICMP:
1584                 poff += sizeof(struct icmphdr);
1585                 break;
1586         case IPPROTO_ICMPV6:
1587                 poff += sizeof(struct icmp6hdr);
1588                 break;
1589         case IPPROTO_IGMP:
1590                 poff += sizeof(struct igmphdr);
1591                 break;
1592         case IPPROTO_DCCP:
1593                 poff += sizeof(struct dccp_hdr);
1594                 break;
1595         case IPPROTO_SCTP:
1596                 poff += sizeof(struct sctphdr);
1597                 break;
1598         }
1599
1600         return poff;
1601 }
1602
1603 /**
1604  * skb_get_poff - get the offset to the payload
1605  * @skb: sk_buff to get the payload offset from
1606  *
1607  * The function will get the offset to the payload as far as it could
1608  * be dissected.  The main user is currently BPF, so that we can dynamically
1609  * truncate packets without needing to push actual payload to the user
1610  * space and can analyze headers only, instead.
1611  */
1612 u32 skb_get_poff(const struct sk_buff *skb)
1613 {
1614         struct flow_keys_basic keys;
1615
1616         if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1617                                               NULL, 0, 0, 0, 0))
1618                 return 0;
1619
1620         return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1621 }
1622
1623 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1624 {
1625         memset(keys, 0, sizeof(*keys));
1626
1627         memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1628             sizeof(keys->addrs.v6addrs.src));
1629         memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1630             sizeof(keys->addrs.v6addrs.dst));
1631         keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1632         keys->ports.src = fl6->fl6_sport;
1633         keys->ports.dst = fl6->fl6_dport;
1634         keys->keyid.keyid = fl6->fl6_gre_key;
1635         keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1636         keys->basic.ip_proto = fl6->flowi6_proto;
1637
1638         return flow_hash_from_keys(keys);
1639 }
1640 EXPORT_SYMBOL(__get_hash_from_flowi6);
1641
1642 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1643         {
1644                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1645                 .offset = offsetof(struct flow_keys, control),
1646         },
1647         {
1648                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1649                 .offset = offsetof(struct flow_keys, basic),
1650         },
1651         {
1652                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1653                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1654         },
1655         {
1656                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1657                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1658         },
1659         {
1660                 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1661                 .offset = offsetof(struct flow_keys, addrs.tipckey),
1662         },
1663         {
1664                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1665                 .offset = offsetof(struct flow_keys, ports),
1666         },
1667         {
1668                 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1669                 .offset = offsetof(struct flow_keys, vlan),
1670         },
1671         {
1672                 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1673                 .offset = offsetof(struct flow_keys, tags),
1674         },
1675         {
1676                 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1677                 .offset = offsetof(struct flow_keys, keyid),
1678         },
1679 };
1680
1681 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1682         {
1683                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1684                 .offset = offsetof(struct flow_keys, control),
1685         },
1686         {
1687                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1688                 .offset = offsetof(struct flow_keys, basic),
1689         },
1690         {
1691                 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1692                 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1693         },
1694         {
1695                 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1696                 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1697         },
1698         {
1699                 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1700                 .offset = offsetof(struct flow_keys, ports),
1701         },
1702 };
1703
1704 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1705         {
1706                 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1707                 .offset = offsetof(struct flow_keys, control),
1708         },
1709         {
1710                 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1711                 .offset = offsetof(struct flow_keys, basic),
1712         },
1713 };
1714
1715 struct flow_dissector flow_keys_dissector __read_mostly;
1716 EXPORT_SYMBOL(flow_keys_dissector);
1717
1718 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1719 EXPORT_SYMBOL(flow_keys_basic_dissector);
1720
1721 static int __init init_default_flow_dissectors(void)
1722 {
1723         skb_flow_dissector_init(&flow_keys_dissector,
1724                                 flow_keys_dissector_keys,
1725                                 ARRAY_SIZE(flow_keys_dissector_keys));
1726         skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1727                                 flow_keys_dissector_symmetric_keys,
1728                                 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1729         skb_flow_dissector_init(&flow_keys_basic_dissector,
1730                                 flow_keys_basic_dissector_keys,
1731                                 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1732         return 0;
1733 }
1734
1735 core_initcall(init_default_flow_dissectors);