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
dissector_set_key(struct flow_dissector * flow_dissector,enum flow_dissector_key_id key_id)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
skb_flow_dissector_init(struct flow_dissector * flow_dissector,const struct flow_dissector_key * key,unsigned int key_count)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
skb_flow_dissector_prog_query(const union bpf_attr * attr,union bpf_attr __user * uattr)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
skb_flow_dissector_bpf_prog_attach(const union bpf_attr * attr,struct bpf_prog * prog)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
skb_flow_dissector_bpf_prog_detach(const union bpf_attr * attr)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 */
skb_flow_get_be16(const struct sk_buff * skb,int poff,void * data,int hlen)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 */
__skb_flow_get_ports(const struct sk_buff * skb,int thoff,u8 ip_proto,void * data,int hlen)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
skb_flow_dissect_meta(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container)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
skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,struct flow_dissector * flow_dissector,void * target_container)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
skb_flow_dissect_ct(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,u16 * ctinfo_map,size_t mapsize)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
skb_flow_dissect_tunnel_info(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container)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
__skb_flow_dissect_mpls(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,int nhoff,int hlen)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
__skb_flow_dissect_arp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,int nhoff,int hlen)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
__skb_flow_dissect_gre(const struct sk_buff * skb,struct flow_dissector_key_control * key_control,struct flow_dissector * flow_dissector,void * target_container,void * data,__be16 * p_proto,int * p_nhoff,int * p_hlen,unsigned int flags)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
__skb_flow_dissect_batadv(const struct sk_buff * skb,struct flow_dissector_key_control * key_control,void * data,__be16 * p_proto,int * p_nhoff,int hlen,unsigned int flags)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
__skb_flow_dissect_tcp(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,int thoff,int hlen)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
__skb_flow_dissect_ipv4(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,const struct iphdr * iph)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
__skb_flow_dissect_ipv6(const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,const struct ipv6hdr * iph)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
skb_flow_dissect_allowed(int * num_hdrs)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
__skb_flow_bpf_to_target(const struct bpf_flow_keys * flow_keys,struct flow_dissector * flow_dissector,void * target_container)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
bpf_flow_dissect(struct bpf_prog * prog,struct bpf_flow_dissector * ctx,__be16 proto,int nhoff,int hlen,unsigned int flags)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 */
__skb_flow_dissect(const struct net * net,const struct sk_buff * skb,struct flow_dissector * flow_dissector,void * target_container,void * data,__be16 proto,int nhoff,int hlen,unsigned int flags)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, ð->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 siphash_key_t hashrnd __read_mostly;
__flow_hash_secret_init(void)1354 static __always_inline void __flow_hash_secret_init(void)
1355 {
1356 net_get_random_once(&hashrnd, sizeof(hashrnd));
1357 }
1358
flow_keys_hash_start(const struct flow_keys * flow)1359 static const void *flow_keys_hash_start(const struct flow_keys *flow)
1360 {
1361 BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1362 return &flow->FLOW_KEYS_HASH_START_FIELD;
1363 }
1364
flow_keys_hash_length(const struct flow_keys * flow)1365 static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1366 {
1367 size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
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;
1383 }
1384
flow_get_u32_src(const struct flow_keys * flow)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
flow_get_u32_dst(const struct flow_keys * flow)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
__flow_hash_consistentify(struct flow_keys * keys)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
__flow_hash_from_keys(struct flow_keys * keys,const siphash_key_t * keyval)1448 static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1449 const siphash_key_t *keyval)
1450 {
1451 u32 hash;
1452
1453 __flow_hash_consistentify(keys);
1454
1455 hash = siphash(flow_keys_hash_start(keys),
1456 flow_keys_hash_length(keys), keyval);
1457 if (!hash)
1458 hash = 1;
1459
1460 return hash;
1461 }
1462
flow_hash_from_keys(struct flow_keys * keys)1463 u32 flow_hash_from_keys(struct flow_keys *keys)
1464 {
1465 __flow_hash_secret_init();
1466 return __flow_hash_from_keys(keys, &hashrnd);
1467 }
1468 EXPORT_SYMBOL(flow_hash_from_keys);
1469
___skb_get_hash(const struct sk_buff * skb,struct flow_keys * keys,const siphash_key_t * keyval)1470 static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1471 struct flow_keys *keys,
1472 const siphash_key_t *keyval)
1473 {
1474 skb_flow_dissect_flow_keys(skb, keys,
1475 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1476
1477 return __flow_hash_from_keys(keys, keyval);
1478 }
1479
1480 struct _flow_keys_digest_data {
1481 __be16 n_proto;
1482 u8 ip_proto;
1483 u8 padding;
1484 __be32 ports;
1485 __be32 src;
1486 __be32 dst;
1487 };
1488
make_flow_keys_digest(struct flow_keys_digest * digest,const struct flow_keys * flow)1489 void make_flow_keys_digest(struct flow_keys_digest *digest,
1490 const struct flow_keys *flow)
1491 {
1492 struct _flow_keys_digest_data *data =
1493 (struct _flow_keys_digest_data *)digest;
1494
1495 BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1496
1497 memset(digest, 0, sizeof(*digest));
1498
1499 data->n_proto = flow->basic.n_proto;
1500 data->ip_proto = flow->basic.ip_proto;
1501 data->ports = flow->ports.ports;
1502 data->src = flow->addrs.v4addrs.src;
1503 data->dst = flow->addrs.v4addrs.dst;
1504 }
1505 EXPORT_SYMBOL(make_flow_keys_digest);
1506
1507 static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1508
__skb_get_hash_symmetric(const struct sk_buff * skb)1509 u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1510 {
1511 struct flow_keys keys;
1512
1513 __flow_hash_secret_init();
1514
1515 memset(&keys, 0, sizeof(keys));
1516 __skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1517 &keys, NULL, 0, 0, 0,
1518 FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1519
1520 return __flow_hash_from_keys(&keys, &hashrnd);
1521 }
1522 EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1523
1524 /**
1525 * __skb_get_hash: calculate a flow hash
1526 * @skb: sk_buff to calculate flow hash from
1527 *
1528 * This function calculates a flow hash based on src/dst addresses
1529 * and src/dst port numbers. Sets hash in skb to non-zero hash value
1530 * on success, zero indicates no valid hash. Also, sets l4_hash in skb
1531 * if hash is a canonical 4-tuple hash over transport ports.
1532 */
__skb_get_hash(struct sk_buff * skb)1533 void __skb_get_hash(struct sk_buff *skb)
1534 {
1535 struct flow_keys keys;
1536 u32 hash;
1537
1538 __flow_hash_secret_init();
1539
1540 hash = ___skb_get_hash(skb, &keys, &hashrnd);
1541
1542 __skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1543 }
1544 EXPORT_SYMBOL(__skb_get_hash);
1545
skb_get_hash_perturb(const struct sk_buff * skb,const siphash_key_t * perturb)1546 __u32 skb_get_hash_perturb(const struct sk_buff *skb,
1547 const siphash_key_t *perturb)
1548 {
1549 struct flow_keys keys;
1550
1551 return ___skb_get_hash(skb, &keys, perturb);
1552 }
1553 EXPORT_SYMBOL(skb_get_hash_perturb);
1554
__skb_get_poff(const struct sk_buff * skb,void * data,const struct flow_keys_basic * keys,int hlen)1555 u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1556 const struct flow_keys_basic *keys, int hlen)
1557 {
1558 u32 poff = keys->control.thoff;
1559
1560 /* skip L4 headers for fragments after the first */
1561 if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1562 !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1563 return poff;
1564
1565 switch (keys->basic.ip_proto) {
1566 case IPPROTO_TCP: {
1567 /* access doff as u8 to avoid unaligned access */
1568 const u8 *doff;
1569 u8 _doff;
1570
1571 doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1572 data, hlen, &_doff);
1573 if (!doff)
1574 return poff;
1575
1576 poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1577 break;
1578 }
1579 case IPPROTO_UDP:
1580 case IPPROTO_UDPLITE:
1581 poff += sizeof(struct udphdr);
1582 break;
1583 /* For the rest, we do not really care about header
1584 * extensions at this point for now.
1585 */
1586 case IPPROTO_ICMP:
1587 poff += sizeof(struct icmphdr);
1588 break;
1589 case IPPROTO_ICMPV6:
1590 poff += sizeof(struct icmp6hdr);
1591 break;
1592 case IPPROTO_IGMP:
1593 poff += sizeof(struct igmphdr);
1594 break;
1595 case IPPROTO_DCCP:
1596 poff += sizeof(struct dccp_hdr);
1597 break;
1598 case IPPROTO_SCTP:
1599 poff += sizeof(struct sctphdr);
1600 break;
1601 }
1602
1603 return poff;
1604 }
1605
1606 /**
1607 * skb_get_poff - get the offset to the payload
1608 * @skb: sk_buff to get the payload offset from
1609 *
1610 * The function will get the offset to the payload as far as it could
1611 * be dissected. The main user is currently BPF, so that we can dynamically
1612 * truncate packets without needing to push actual payload to the user
1613 * space and can analyze headers only, instead.
1614 */
skb_get_poff(const struct sk_buff * skb)1615 u32 skb_get_poff(const struct sk_buff *skb)
1616 {
1617 struct flow_keys_basic keys;
1618
1619 if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1620 NULL, 0, 0, 0, 0))
1621 return 0;
1622
1623 return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1624 }
1625
__get_hash_from_flowi6(const struct flowi6 * fl6,struct flow_keys * keys)1626 __u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1627 {
1628 memset(keys, 0, sizeof(*keys));
1629
1630 memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1631 sizeof(keys->addrs.v6addrs.src));
1632 memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1633 sizeof(keys->addrs.v6addrs.dst));
1634 keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1635 keys->ports.src = fl6->fl6_sport;
1636 keys->ports.dst = fl6->fl6_dport;
1637 keys->keyid.keyid = fl6->fl6_gre_key;
1638 keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1639 keys->basic.ip_proto = fl6->flowi6_proto;
1640
1641 return flow_hash_from_keys(keys);
1642 }
1643 EXPORT_SYMBOL(__get_hash_from_flowi6);
1644
1645 static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1646 {
1647 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1648 .offset = offsetof(struct flow_keys, control),
1649 },
1650 {
1651 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1652 .offset = offsetof(struct flow_keys, basic),
1653 },
1654 {
1655 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1656 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1657 },
1658 {
1659 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1660 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1661 },
1662 {
1663 .key_id = FLOW_DISSECTOR_KEY_TIPC,
1664 .offset = offsetof(struct flow_keys, addrs.tipckey),
1665 },
1666 {
1667 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1668 .offset = offsetof(struct flow_keys, ports),
1669 },
1670 {
1671 .key_id = FLOW_DISSECTOR_KEY_VLAN,
1672 .offset = offsetof(struct flow_keys, vlan),
1673 },
1674 {
1675 .key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1676 .offset = offsetof(struct flow_keys, tags),
1677 },
1678 {
1679 .key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1680 .offset = offsetof(struct flow_keys, keyid),
1681 },
1682 };
1683
1684 static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1685 {
1686 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1687 .offset = offsetof(struct flow_keys, control),
1688 },
1689 {
1690 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1691 .offset = offsetof(struct flow_keys, basic),
1692 },
1693 {
1694 .key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1695 .offset = offsetof(struct flow_keys, addrs.v4addrs),
1696 },
1697 {
1698 .key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1699 .offset = offsetof(struct flow_keys, addrs.v6addrs),
1700 },
1701 {
1702 .key_id = FLOW_DISSECTOR_KEY_PORTS,
1703 .offset = offsetof(struct flow_keys, ports),
1704 },
1705 };
1706
1707 static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1708 {
1709 .key_id = FLOW_DISSECTOR_KEY_CONTROL,
1710 .offset = offsetof(struct flow_keys, control),
1711 },
1712 {
1713 .key_id = FLOW_DISSECTOR_KEY_BASIC,
1714 .offset = offsetof(struct flow_keys, basic),
1715 },
1716 };
1717
1718 struct flow_dissector flow_keys_dissector __read_mostly;
1719 EXPORT_SYMBOL(flow_keys_dissector);
1720
1721 struct flow_dissector flow_keys_basic_dissector __read_mostly;
1722 EXPORT_SYMBOL(flow_keys_basic_dissector);
1723
init_default_flow_dissectors(void)1724 static int __init init_default_flow_dissectors(void)
1725 {
1726 skb_flow_dissector_init(&flow_keys_dissector,
1727 flow_keys_dissector_keys,
1728 ARRAY_SIZE(flow_keys_dissector_keys));
1729 skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1730 flow_keys_dissector_symmetric_keys,
1731 ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1732 skb_flow_dissector_init(&flow_keys_basic_dissector,
1733 flow_keys_basic_dissector_keys,
1734 ARRAY_SIZE(flow_keys_basic_dissector_keys));
1735 return 0;
1736 }
1737
1738 core_initcall(init_default_flow_dissectors);
1739
