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