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  1#include <linux/kernel.h>
  2#include <linux/skbuff.h>
  3#include <linux/export.h>
  4#include <linux/ip.h>
  5#include <linux/ipv6.h>
  6#include <linux/if_vlan.h>
  7#include <net/ip.h>
  8#include <net/ipv6.h>
  9#include <linux/igmp.h>
 10#include <linux/icmp.h>
 11#include <linux/sctp.h>
 12#include <linux/dccp.h>
 13#include <linux/if_tunnel.h>
 14#include <linux/if_pppox.h>
 15#include <linux/ppp_defs.h>
 16#include <linux/stddef.h>
 17#include <linux/if_ether.h>
 18#include <linux/mpls.h>
 19#include <net/flow_dissector.h>
 20#include <scsi/fc/fc_fcoe.h>
 21
 22static void dissector_set_key(struct flow_dissector *flow_dissector,
 23			      enum flow_dissector_key_id key_id)
 24{
 25	flow_dissector->used_keys |= (1 << key_id);
 26}
 27
 28void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
 29			     const struct flow_dissector_key *key,
 30			     unsigned int key_count)
 31{
 32	unsigned int i;
 33
 34	memset(flow_dissector, 0, sizeof(*flow_dissector));
 35
 36	for (i = 0; i < key_count; i++, key++) {
 37		/* User should make sure that every key target offset is withing
 38		 * boundaries of unsigned short.
 39		 */
 40		BUG_ON(key->offset > USHRT_MAX);
 41		BUG_ON(dissector_uses_key(flow_dissector,
 42					  key->key_id));
 43
 44		dissector_set_key(flow_dissector, key->key_id);
 45		flow_dissector->offset[key->key_id] = key->offset;
 46	}
 47
 48	/* Ensure that the dissector always includes control and basic key.
 49	 * That way we are able to avoid handling lack of these in fast path.
 50	 */
 51	BUG_ON(!dissector_uses_key(flow_dissector,
 52				   FLOW_DISSECTOR_KEY_CONTROL));
 53	BUG_ON(!dissector_uses_key(flow_dissector,
 54				   FLOW_DISSECTOR_KEY_BASIC));
 55}
 56EXPORT_SYMBOL(skb_flow_dissector_init);
 57
 58/**
 59 * __skb_flow_get_ports - extract the upper layer ports and return them
 60 * @skb: sk_buff to extract the ports from
 61 * @thoff: transport header offset
 62 * @ip_proto: protocol for which to get port offset
 63 * @data: raw buffer pointer to the packet, if NULL use skb->data
 64 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 65 *
 66 * The function will try to retrieve the ports at offset thoff + poff where poff
 67 * is the protocol port offset returned from proto_ports_offset
 68 */
 69__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 70			    void *data, int hlen)
 71{
 72	int poff = proto_ports_offset(ip_proto);
 73
 74	if (!data) {
 75		data = skb->data;
 76		hlen = skb_headlen(skb);
 77	}
 78
 79	if (poff >= 0) {
 80		__be32 *ports, _ports;
 81
 82		ports = __skb_header_pointer(skb, thoff + poff,
 83					     sizeof(_ports), data, hlen, &_ports);
 84		if (ports)
 85			return *ports;
 86	}
 87
 88	return 0;
 89}
 90EXPORT_SYMBOL(__skb_flow_get_ports);
 91
 92/**
 93 * __skb_flow_dissect - extract the flow_keys struct and return it
 94 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 95 * @flow_dissector: list of keys to dissect
 96 * @target_container: target structure to put dissected values into
 97 * @data: raw buffer pointer to the packet, if NULL use skb->data
 98 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 99 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
100 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
101 *
102 * The function will try to retrieve individual keys into target specified
103 * by flow_dissector from either the skbuff or a raw buffer specified by the
104 * rest parameters.
105 *
106 * Caller must take care of zeroing target container memory.
107 */
108bool __skb_flow_dissect(const struct sk_buff *skb,
109			struct flow_dissector *flow_dissector,
110			void *target_container,
111			void *data, __be16 proto, int nhoff, int hlen,
112			unsigned int flags)
113{
114	struct flow_dissector_key_control *key_control;
115	struct flow_dissector_key_basic *key_basic;
116	struct flow_dissector_key_addrs *key_addrs;
117	struct flow_dissector_key_ports *key_ports;
118	struct flow_dissector_key_tags *key_tags;
119	struct flow_dissector_key_keyid *key_keyid;
120	u8 ip_proto = 0;
121	bool ret = false;
122
123	if (!data) {
124		data = skb->data;
125		proto = skb->protocol;
126		nhoff = skb_network_offset(skb);
127		hlen = skb_headlen(skb);
128	}
129
130	/* It is ensured by skb_flow_dissector_init() that control key will
131	 * be always present.
132	 */
133	key_control = skb_flow_dissector_target(flow_dissector,
134						FLOW_DISSECTOR_KEY_CONTROL,
135						target_container);
136
137	/* It is ensured by skb_flow_dissector_init() that basic key will
138	 * be always present.
139	 */
140	key_basic = skb_flow_dissector_target(flow_dissector,
141					      FLOW_DISSECTOR_KEY_BASIC,
142					      target_container);
143
144	if (dissector_uses_key(flow_dissector,
145			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
146		struct ethhdr *eth = eth_hdr(skb);
147		struct flow_dissector_key_eth_addrs *key_eth_addrs;
148
149		key_eth_addrs = skb_flow_dissector_target(flow_dissector,
150							  FLOW_DISSECTOR_KEY_ETH_ADDRS,
151							  target_container);
152		memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
153	}
154
155again:
156	switch (proto) {
157	case htons(ETH_P_IP): {
158		const struct iphdr *iph;
159		struct iphdr _iph;
160ip:
161		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
162		if (!iph || iph->ihl < 5)
163			goto out_bad;
164		nhoff += iph->ihl * 4;
165
166		ip_proto = iph->protocol;
167
168		if (dissector_uses_key(flow_dissector,
169				       FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
170			key_addrs = skb_flow_dissector_target(flow_dissector,
171							      FLOW_DISSECTOR_KEY_IPV4_ADDRS,
172							      target_container);
173
174			memcpy(&key_addrs->v4addrs, &iph->saddr,
175			       sizeof(key_addrs->v4addrs));
176			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
177		}
178
179		if (ip_is_fragment(iph)) {
180			key_control->flags |= FLOW_DIS_IS_FRAGMENT;
181
182			if (iph->frag_off & htons(IP_OFFSET)) {
183				goto out_good;
184			} else {
185				key_control->flags |= FLOW_DIS_FIRST_FRAG;
186				if (!(flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG))
187					goto out_good;
188			}
189		}
190
191		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
192			goto out_good;
193
194		break;
195	}
196	case htons(ETH_P_IPV6): {
197		const struct ipv6hdr *iph;
198		struct ipv6hdr _iph;
199
200ipv6:
201		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
202		if (!iph)
203			goto out_bad;
204
205		ip_proto = iph->nexthdr;
206		nhoff += sizeof(struct ipv6hdr);
207
208		if (dissector_uses_key(flow_dissector,
209				       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
210			key_addrs = skb_flow_dissector_target(flow_dissector,
211							      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
212							      target_container);
213
214			memcpy(&key_addrs->v6addrs, &iph->saddr,
215			       sizeof(key_addrs->v6addrs));
216			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
217		}
218
219		if ((dissector_uses_key(flow_dissector,
220					FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
221		     (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
222		    ip6_flowlabel(iph)) {
223			__be32 flow_label = ip6_flowlabel(iph);
224
225			if (dissector_uses_key(flow_dissector,
226					       FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
227				key_tags = skb_flow_dissector_target(flow_dissector,
228								     FLOW_DISSECTOR_KEY_FLOW_LABEL,
229								     target_container);
230				key_tags->flow_label = ntohl(flow_label);
231			}
232			if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)
233				goto out_good;
234		}
235
236		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
237			goto out_good;
238
239		break;
240	}
241	case htons(ETH_P_8021AD):
242	case htons(ETH_P_8021Q): {
243		const struct vlan_hdr *vlan;
244		struct vlan_hdr _vlan;
245
246		vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
247		if (!vlan)
248			goto out_bad;
249
250		if (dissector_uses_key(flow_dissector,
251				       FLOW_DISSECTOR_KEY_VLANID)) {
252			key_tags = skb_flow_dissector_target(flow_dissector,
253							     FLOW_DISSECTOR_KEY_VLANID,
254							     target_container);
255
256			key_tags->vlan_id = skb_vlan_tag_get_id(skb);
257		}
258
259		proto = vlan->h_vlan_encapsulated_proto;
260		nhoff += sizeof(*vlan);
261		goto again;
262	}
263	case htons(ETH_P_PPP_SES): {
264		struct {
265			struct pppoe_hdr hdr;
266			__be16 proto;
267		} *hdr, _hdr;
268		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
269		if (!hdr)
270			goto out_bad;
271		proto = hdr->proto;
272		nhoff += PPPOE_SES_HLEN;
273		switch (proto) {
274		case htons(PPP_IP):
275			goto ip;
276		case htons(PPP_IPV6):
277			goto ipv6;
278		default:
279			goto out_bad;
280		}
281	}
282	case htons(ETH_P_TIPC): {
283		struct {
284			__be32 pre[3];
285			__be32 srcnode;
286		} *hdr, _hdr;
287		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
288		if (!hdr)
289			goto out_bad;
290
291		if (dissector_uses_key(flow_dissector,
292				       FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
293			key_addrs = skb_flow_dissector_target(flow_dissector,
294							      FLOW_DISSECTOR_KEY_TIPC_ADDRS,
295							      target_container);
296			key_addrs->tipcaddrs.srcnode = hdr->srcnode;
297			key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
298		}
299		goto out_good;
300	}
301
302	case htons(ETH_P_MPLS_UC):
303	case htons(ETH_P_MPLS_MC): {
304		struct mpls_label *hdr, _hdr[2];
305mpls:
306		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
307					   hlen, &_hdr);
308		if (!hdr)
309			goto out_bad;
310
311		if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
312		     MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
313			if (dissector_uses_key(flow_dissector,
314					       FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
315				key_keyid = skb_flow_dissector_target(flow_dissector,
316								      FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
317								      target_container);
318				key_keyid->keyid = hdr[1].entry &
319					htonl(MPLS_LS_LABEL_MASK);
320			}
321
322			goto out_good;
323		}
324
325		goto out_good;
326	}
327
328	case htons(ETH_P_FCOE):
329		if ((hlen - nhoff) < FCOE_HEADER_LEN)
330			goto out_bad;
331
332		nhoff += FCOE_HEADER_LEN;
333		goto out_good;
334	default:
335		goto out_bad;
336	}
337
338ip_proto_again:
339	switch (ip_proto) {
340	case IPPROTO_GRE: {
341		struct gre_hdr {
342			__be16 flags;
343			__be16 proto;
344		} *hdr, _hdr;
345
346		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
347		if (!hdr)
348			goto out_bad;
349		/*
350		 * Only look inside GRE if version zero and no
351		 * routing
352		 */
353		if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
354			break;
355
356		proto = hdr->proto;
357		nhoff += 4;
358		if (hdr->flags & GRE_CSUM)
359			nhoff += 4;
360		if (hdr->flags & GRE_KEY) {
361			const __be32 *keyid;
362			__be32 _keyid;
363
364			keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
365						     data, hlen, &_keyid);
366
367			if (!keyid)
368				goto out_bad;
369
370			if (dissector_uses_key(flow_dissector,
371					       FLOW_DISSECTOR_KEY_GRE_KEYID)) {
372				key_keyid = skb_flow_dissector_target(flow_dissector,
373								      FLOW_DISSECTOR_KEY_GRE_KEYID,
374								      target_container);
375				key_keyid->keyid = *keyid;
376			}
377			nhoff += 4;
378		}
379		if (hdr->flags & GRE_SEQ)
380			nhoff += 4;
381		if (proto == htons(ETH_P_TEB)) {
382			const struct ethhdr *eth;
383			struct ethhdr _eth;
384
385			eth = __skb_header_pointer(skb, nhoff,
386						   sizeof(_eth),
387						   data, hlen, &_eth);
388			if (!eth)
389				goto out_bad;
390			proto = eth->h_proto;
391			nhoff += sizeof(*eth);
392
393			/* Cap headers that we access via pointers at the
394			 * end of the Ethernet header as our maximum alignment
395			 * at that point is only 2 bytes.
396			 */
397			if (NET_IP_ALIGN)
398				hlen = nhoff;
399		}
400
401		key_control->flags |= FLOW_DIS_ENCAPSULATION;
402		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
403			goto out_good;
404
405		goto again;
406	}
407	case NEXTHDR_HOP:
408	case NEXTHDR_ROUTING:
409	case NEXTHDR_DEST: {
410		u8 _opthdr[2], *opthdr;
411
412		if (proto != htons(ETH_P_IPV6))
413			break;
414
415		opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
416					      data, hlen, &_opthdr);
417		if (!opthdr)
418			goto out_bad;
419
420		ip_proto = opthdr[0];
421		nhoff += (opthdr[1] + 1) << 3;
422
423		goto ip_proto_again;
424	}
425	case NEXTHDR_FRAGMENT: {
426		struct frag_hdr _fh, *fh;
427
428		if (proto != htons(ETH_P_IPV6))
429			break;
430
431		fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
432					  data, hlen, &_fh);
433
434		if (!fh)
435			goto out_bad;
436
437		key_control->flags |= FLOW_DIS_IS_FRAGMENT;
438
439		nhoff += sizeof(_fh);
440		ip_proto = fh->nexthdr;
441
442		if (!(fh->frag_off & htons(IP6_OFFSET))) {
443			key_control->flags |= FLOW_DIS_FIRST_FRAG;
444			if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG)
445				goto ip_proto_again;
446		}
447		goto out_good;
448	}
449	case IPPROTO_IPIP:
450		proto = htons(ETH_P_IP);
451
452		key_control->flags |= FLOW_DIS_ENCAPSULATION;
453		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
454			goto out_good;
455
456		goto ip;
457	case IPPROTO_IPV6:
458		proto = htons(ETH_P_IPV6);
459
460		key_control->flags |= FLOW_DIS_ENCAPSULATION;
461		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
462			goto out_good;
463
464		goto ipv6;
465	case IPPROTO_MPLS:
466		proto = htons(ETH_P_MPLS_UC);
467		goto mpls;
468	default:
469		break;
470	}
471
472	if (dissector_uses_key(flow_dissector,
473			       FLOW_DISSECTOR_KEY_PORTS)) {
474		key_ports = skb_flow_dissector_target(flow_dissector,
475						      FLOW_DISSECTOR_KEY_PORTS,
476						      target_container);
477		key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
478							data, hlen);
479	}
480
481out_good:
482	ret = true;
483
484out_bad:
485	key_basic->n_proto = proto;
486	key_basic->ip_proto = ip_proto;
487	key_control->thoff = (u16)nhoff;
488
489	return ret;
490}
491EXPORT_SYMBOL(__skb_flow_dissect);
492
493static u32 hashrnd __read_mostly;
494static __always_inline void __flow_hash_secret_init(void)
495{
496	net_get_random_once(&hashrnd, sizeof(hashrnd));
497}
498
499static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
500					     u32 keyval)
501{
502	return jhash2(words, length, keyval);
503}
504
505static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
506{
507	const void *p = flow;
508
509	BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
510	return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
511}
512
513static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
514{
515	size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
516	BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
517	BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
518		     sizeof(*flow) - sizeof(flow->addrs));
519
520	switch (flow->control.addr_type) {
521	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
522		diff -= sizeof(flow->addrs.v4addrs);
523		break;
524	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
525		diff -= sizeof(flow->addrs.v6addrs);
526		break;
527	case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
528		diff -= sizeof(flow->addrs.tipcaddrs);
529		break;
530	}
531	return (sizeof(*flow) - diff) / sizeof(u32);
532}
533
534__be32 flow_get_u32_src(const struct flow_keys *flow)
535{
536	switch (flow->control.addr_type) {
537	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
538		return flow->addrs.v4addrs.src;
539	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
540		return (__force __be32)ipv6_addr_hash(
541			&flow->addrs.v6addrs.src);
542	case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
543		return flow->addrs.tipcaddrs.srcnode;
544	default:
545		return 0;
546	}
547}
548EXPORT_SYMBOL(flow_get_u32_src);
549
550__be32 flow_get_u32_dst(const struct flow_keys *flow)
551{
552	switch (flow->control.addr_type) {
553	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
554		return flow->addrs.v4addrs.dst;
555	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
556		return (__force __be32)ipv6_addr_hash(
557			&flow->addrs.v6addrs.dst);
558	default:
559		return 0;
560	}
561}
562EXPORT_SYMBOL(flow_get_u32_dst);
563
564static inline void __flow_hash_consistentify(struct flow_keys *keys)
565{
566	int addr_diff, i;
567
568	switch (keys->control.addr_type) {
569	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
570		addr_diff = (__force u32)keys->addrs.v4addrs.dst -
571			    (__force u32)keys->addrs.v4addrs.src;
572		if ((addr_diff < 0) ||
573		    (addr_diff == 0 &&
574		     ((__force u16)keys->ports.dst <
575		      (__force u16)keys->ports.src))) {
576			swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
577			swap(keys->ports.src, keys->ports.dst);
578		}
579		break;
580	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
581		addr_diff = memcmp(&keys->addrs.v6addrs.dst,
582				   &keys->addrs.v6addrs.src,
583				   sizeof(keys->addrs.v6addrs.dst));
584		if ((addr_diff < 0) ||
585		    (addr_diff == 0 &&
586		     ((__force u16)keys->ports.dst <
587		      (__force u16)keys->ports.src))) {
588			for (i = 0; i < 4; i++)
589				swap(keys->addrs.v6addrs.src.s6_addr32[i],
590				     keys->addrs.v6addrs.dst.s6_addr32[i]);
591			swap(keys->ports.src, keys->ports.dst);
592		}
593		break;
594	}
595}
596
597static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
598{
599	u32 hash;
600
601	__flow_hash_consistentify(keys);
602
603	hash = __flow_hash_words(flow_keys_hash_start(keys),
604				 flow_keys_hash_length(keys), keyval);
605	if (!hash)
606		hash = 1;
607
608	return hash;
609}
610
611u32 flow_hash_from_keys(struct flow_keys *keys)
612{
613	__flow_hash_secret_init();
614	return __flow_hash_from_keys(keys, hashrnd);
615}
616EXPORT_SYMBOL(flow_hash_from_keys);
617
618static inline u32 ___skb_get_hash(const struct sk_buff *skb,
619				  struct flow_keys *keys, u32 keyval)
620{
621	skb_flow_dissect_flow_keys(skb, keys,
622				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
623
624	return __flow_hash_from_keys(keys, keyval);
625}
626
627struct _flow_keys_digest_data {
628	__be16	n_proto;
629	u8	ip_proto;
630	u8	padding;
631	__be32	ports;
632	__be32	src;
633	__be32	dst;
634};
635
636void make_flow_keys_digest(struct flow_keys_digest *digest,
637			   const struct flow_keys *flow)
638{
639	struct _flow_keys_digest_data *data =
640	    (struct _flow_keys_digest_data *)digest;
641
642	BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
643
644	memset(digest, 0, sizeof(*digest));
645
646	data->n_proto = flow->basic.n_proto;
647	data->ip_proto = flow->basic.ip_proto;
648	data->ports = flow->ports.ports;
649	data->src = flow->addrs.v4addrs.src;
650	data->dst = flow->addrs.v4addrs.dst;
651}
652EXPORT_SYMBOL(make_flow_keys_digest);
653
654/**
655 * __skb_get_hash: calculate a flow hash
656 * @skb: sk_buff to calculate flow hash from
657 *
658 * This function calculates a flow hash based on src/dst addresses
659 * and src/dst port numbers.  Sets hash in skb to non-zero hash value
660 * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
661 * if hash is a canonical 4-tuple hash over transport ports.
662 */
663void __skb_get_hash(struct sk_buff *skb)
664{
665	struct flow_keys keys;
666
667	__flow_hash_secret_init();
668
669	__skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
670			  flow_keys_have_l4(&keys));
671}
672EXPORT_SYMBOL(__skb_get_hash);
673
674__u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
675{
676	struct flow_keys keys;
677
678	return ___skb_get_hash(skb, &keys, perturb);
679}
680EXPORT_SYMBOL(skb_get_hash_perturb);
681
682__u32 __skb_get_hash_flowi6(struct sk_buff *skb, const struct flowi6 *fl6)
683{
684	struct flow_keys keys;
685
686	memset(&keys, 0, sizeof(keys));
687
688	memcpy(&keys.addrs.v6addrs.src, &fl6->saddr,
689	       sizeof(keys.addrs.v6addrs.src));
690	memcpy(&keys.addrs.v6addrs.dst, &fl6->daddr,
691	       sizeof(keys.addrs.v6addrs.dst));
692	keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
693	keys.ports.src = fl6->fl6_sport;
694	keys.ports.dst = fl6->fl6_dport;
695	keys.keyid.keyid = fl6->fl6_gre_key;
696	keys.tags.flow_label = (__force u32)fl6->flowlabel;
697	keys.basic.ip_proto = fl6->flowi6_proto;
698
699	__skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
700			  flow_keys_have_l4(&keys));
701
702	return skb->hash;
703}
704EXPORT_SYMBOL(__skb_get_hash_flowi6);
705
706__u32 __skb_get_hash_flowi4(struct sk_buff *skb, const struct flowi4 *fl4)
707{
708	struct flow_keys keys;
709
710	memset(&keys, 0, sizeof(keys));
711
712	keys.addrs.v4addrs.src = fl4->saddr;
713	keys.addrs.v4addrs.dst = fl4->daddr;
714	keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
715	keys.ports.src = fl4->fl4_sport;
716	keys.ports.dst = fl4->fl4_dport;
717	keys.keyid.keyid = fl4->fl4_gre_key;
718	keys.basic.ip_proto = fl4->flowi4_proto;
719
720	__skb_set_sw_hash(skb, flow_hash_from_keys(&keys),
721			  flow_keys_have_l4(&keys));
722
723	return skb->hash;
724}
725EXPORT_SYMBOL(__skb_get_hash_flowi4);
726
727u32 __skb_get_poff(const struct sk_buff *skb, void *data,
728		   const struct flow_keys *keys, int hlen)
729{
730	u32 poff = keys->control.thoff;
731
732	/* skip L4 headers for fragments after the first */
733	if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
734	    !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
735		return poff;
736
737	switch (keys->basic.ip_proto) {
738	case IPPROTO_TCP: {
739		/* access doff as u8 to avoid unaligned access */
740		const u8 *doff;
741		u8 _doff;
742
743		doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
744					    data, hlen, &_doff);
745		if (!doff)
746			return poff;
747
748		poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
749		break;
750	}
751	case IPPROTO_UDP:
752	case IPPROTO_UDPLITE:
753		poff += sizeof(struct udphdr);
754		break;
755	/* For the rest, we do not really care about header
756	 * extensions at this point for now.
757	 */
758	case IPPROTO_ICMP:
759		poff += sizeof(struct icmphdr);
760		break;
761	case IPPROTO_ICMPV6:
762		poff += sizeof(struct icmp6hdr);
763		break;
764	case IPPROTO_IGMP:
765		poff += sizeof(struct igmphdr);
766		break;
767	case IPPROTO_DCCP:
768		poff += sizeof(struct dccp_hdr);
769		break;
770	case IPPROTO_SCTP:
771		poff += sizeof(struct sctphdr);
772		break;
773	}
774
775	return poff;
776}
777
778/**
779 * skb_get_poff - get the offset to the payload
780 * @skb: sk_buff to get the payload offset from
781 *
782 * The function will get the offset to the payload as far as it could
783 * be dissected.  The main user is currently BPF, so that we can dynamically
784 * truncate packets without needing to push actual payload to the user
785 * space and can analyze headers only, instead.
786 */
787u32 skb_get_poff(const struct sk_buff *skb)
788{
789	struct flow_keys keys;
790
791	if (!skb_flow_dissect_flow_keys(skb, &keys, 0))
792		return 0;
793
794	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
795}
796
797__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
798{
799	memset(keys, 0, sizeof(*keys));
800
801	memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
802	    sizeof(keys->addrs.v6addrs.src));
803	memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
804	    sizeof(keys->addrs.v6addrs.dst));
805	keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
806	keys->ports.src = fl6->fl6_sport;
807	keys->ports.dst = fl6->fl6_dport;
808	keys->keyid.keyid = fl6->fl6_gre_key;
809	keys->tags.flow_label = (__force u32)fl6->flowlabel;
810	keys->basic.ip_proto = fl6->flowi6_proto;
811
812	return flow_hash_from_keys(keys);
813}
814EXPORT_SYMBOL(__get_hash_from_flowi6);
815
816__u32 __get_hash_from_flowi4(const struct flowi4 *fl4, struct flow_keys *keys)
817{
818	memset(keys, 0, sizeof(*keys));
819
820	keys->addrs.v4addrs.src = fl4->saddr;
821	keys->addrs.v4addrs.dst = fl4->daddr;
822	keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
823	keys->ports.src = fl4->fl4_sport;
824	keys->ports.dst = fl4->fl4_dport;
825	keys->keyid.keyid = fl4->fl4_gre_key;
826	keys->basic.ip_proto = fl4->flowi4_proto;
827
828	return flow_hash_from_keys(keys);
829}
830EXPORT_SYMBOL(__get_hash_from_flowi4);
831
832static const struct flow_dissector_key flow_keys_dissector_keys[] = {
833	{
834		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
835		.offset = offsetof(struct flow_keys, control),
836	},
837	{
838		.key_id = FLOW_DISSECTOR_KEY_BASIC,
839		.offset = offsetof(struct flow_keys, basic),
840	},
841	{
842		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
843		.offset = offsetof(struct flow_keys, addrs.v4addrs),
844	},
845	{
846		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
847		.offset = offsetof(struct flow_keys, addrs.v6addrs),
848	},
849	{
850		.key_id = FLOW_DISSECTOR_KEY_TIPC_ADDRS,
851		.offset = offsetof(struct flow_keys, addrs.tipcaddrs),
852	},
853	{
854		.key_id = FLOW_DISSECTOR_KEY_PORTS,
855		.offset = offsetof(struct flow_keys, ports),
856	},
857	{
858		.key_id = FLOW_DISSECTOR_KEY_VLANID,
859		.offset = offsetof(struct flow_keys, tags),
860	},
861	{
862		.key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
863		.offset = offsetof(struct flow_keys, tags),
864	},
865	{
866		.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
867		.offset = offsetof(struct flow_keys, keyid),
868	},
869};
870
871static const struct flow_dissector_key flow_keys_buf_dissector_keys[] = {
872	{
873		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
874		.offset = offsetof(struct flow_keys, control),
875	},
876	{
877		.key_id = FLOW_DISSECTOR_KEY_BASIC,
878		.offset = offsetof(struct flow_keys, basic),
879	},
880};
881
882struct flow_dissector flow_keys_dissector __read_mostly;
883EXPORT_SYMBOL(flow_keys_dissector);
884
885struct flow_dissector flow_keys_buf_dissector __read_mostly;
886
887static int __init init_default_flow_dissectors(void)
888{
889	skb_flow_dissector_init(&flow_keys_dissector,
890				flow_keys_dissector_keys,
891				ARRAY_SIZE(flow_keys_dissector_keys));
892	skb_flow_dissector_init(&flow_keys_buf_dissector,
893				flow_keys_buf_dissector_keys,
894				ARRAY_SIZE(flow_keys_buf_dissector_keys));
895	return 0;
896}
897
898late_initcall_sync(init_default_flow_dissectors);
   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
  35static DEFINE_MUTEX(flow_dissector_mutex);
  36
  37static 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
  43void 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}
  71EXPORT_SYMBOL(skb_flow_dissector_init);
  72
  73int 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
 112int 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
 132int 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 */
 160static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
 161				void *data, int hlen)
 162{
 163	__be16 *u, _u;
 164
 165	u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
 166	if (u)
 167		return *u;
 168
 169	return 0;
 170}
 171
 172/**
 173 * __skb_flow_get_ports - extract the upper layer ports and return them
 174 * @skb: sk_buff to extract the ports from
 175 * @thoff: transport header offset
 176 * @ip_proto: protocol for which to get port offset
 177 * @data: raw buffer pointer to the packet, if NULL use skb->data
 178 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 179 *
 180 * The function will try to retrieve the ports at offset thoff + poff where poff
 181 * is the protocol port offset returned from proto_ports_offset
 182 */
 183__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 184			    void *data, int hlen)
 185{
 186	int poff = proto_ports_offset(ip_proto);
 187
 188	if (!data) {
 189		data = skb->data;
 190		hlen = skb_headlen(skb);
 191	}
 192
 193	if (poff >= 0) {
 194		__be32 *ports, _ports;
 195
 196		ports = __skb_header_pointer(skb, thoff + poff,
 197					     sizeof(_ports), data, hlen, &_ports);
 198		if (ports)
 199			return *ports;
 200	}
 201
 202	return 0;
 203}
 204EXPORT_SYMBOL(__skb_flow_get_ports);
 205
 206void 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}
 220EXPORT_SYMBOL(skb_flow_dissect_meta);
 221
 222static void
 223skb_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
 238void
 239skb_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}
 276EXPORT_SYMBOL(skb_flow_dissect_ct);
 277
 278void
 279skb_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}
 386EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 387
 388static enum flow_dissect_ret
 389__skb_flow_dissect_mpls(const struct sk_buff *skb,
 390			struct flow_dissector *flow_dissector,
 391			void *target_container, void *data, int nhoff, int hlen)
 392{
 393	struct flow_dissector_key_keyid *key_keyid;
 394	struct mpls_label *hdr, _hdr[2];
 395	u32 entry, label;
 396
 397	if (!dissector_uses_key(flow_dissector,
 398				FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 399	    !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 400		return FLOW_DISSECT_RET_OUT_GOOD;
 401
 402	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 403				   hlen, &_hdr);
 404	if (!hdr)
 405		return FLOW_DISSECT_RET_OUT_BAD;
 406
 407	entry = ntohl(hdr[0].entry);
 408	label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 409
 410	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 411		struct flow_dissector_key_mpls *key_mpls;
 412
 413		key_mpls = skb_flow_dissector_target(flow_dissector,
 414						     FLOW_DISSECTOR_KEY_MPLS,
 415						     target_container);
 416		key_mpls->mpls_label = label;
 417		key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
 418					>> MPLS_LS_TTL_SHIFT;
 419		key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
 420					>> MPLS_LS_TC_SHIFT;
 421		key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
 422					>> MPLS_LS_S_SHIFT;
 423	}
 424
 425	if (label == MPLS_LABEL_ENTROPY) {
 426		key_keyid = skb_flow_dissector_target(flow_dissector,
 427						      FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 428						      target_container);
 429		key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
 430	}
 431	return FLOW_DISSECT_RET_OUT_GOOD;
 432}
 433
 434static enum flow_dissect_ret
 435__skb_flow_dissect_arp(const struct sk_buff *skb,
 436		       struct flow_dissector *flow_dissector,
 437		       void *target_container, void *data, int nhoff, int hlen)
 438{
 439	struct flow_dissector_key_arp *key_arp;
 440	struct {
 441		unsigned char ar_sha[ETH_ALEN];
 442		unsigned char ar_sip[4];
 443		unsigned char ar_tha[ETH_ALEN];
 444		unsigned char ar_tip[4];
 445	} *arp_eth, _arp_eth;
 446	const struct arphdr *arp;
 447	struct arphdr _arp;
 448
 449	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 450		return FLOW_DISSECT_RET_OUT_GOOD;
 451
 452	arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 453				   hlen, &_arp);
 454	if (!arp)
 455		return FLOW_DISSECT_RET_OUT_BAD;
 456
 457	if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 458	    arp->ar_pro != htons(ETH_P_IP) ||
 459	    arp->ar_hln != ETH_ALEN ||
 460	    arp->ar_pln != 4 ||
 461	    (arp->ar_op != htons(ARPOP_REPLY) &&
 462	     arp->ar_op != htons(ARPOP_REQUEST)))
 463		return FLOW_DISSECT_RET_OUT_BAD;
 464
 465	arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 466				       sizeof(_arp_eth), data,
 467				       hlen, &_arp_eth);
 468	if (!arp_eth)
 469		return FLOW_DISSECT_RET_OUT_BAD;
 470
 471	key_arp = skb_flow_dissector_target(flow_dissector,
 472					    FLOW_DISSECTOR_KEY_ARP,
 473					    target_container);
 474
 475	memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 476	memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 477
 478	/* Only store the lower byte of the opcode;
 479	 * this covers ARPOP_REPLY and ARPOP_REQUEST.
 480	 */
 481	key_arp->op = ntohs(arp->ar_op) & 0xff;
 482
 483	ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 484	ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 485
 486	return FLOW_DISSECT_RET_OUT_GOOD;
 487}
 488
 489static enum flow_dissect_ret
 490__skb_flow_dissect_gre(const struct sk_buff *skb,
 491		       struct flow_dissector_key_control *key_control,
 492		       struct flow_dissector *flow_dissector,
 493		       void *target_container, void *data,
 494		       __be16 *p_proto, int *p_nhoff, int *p_hlen,
 495		       unsigned int flags)
 496{
 497	struct flow_dissector_key_keyid *key_keyid;
 498	struct gre_base_hdr *hdr, _hdr;
 499	int offset = 0;
 500	u16 gre_ver;
 501
 502	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 503				   data, *p_hlen, &_hdr);
 504	if (!hdr)
 505		return FLOW_DISSECT_RET_OUT_BAD;
 506
 507	/* Only look inside GRE without routing */
 508	if (hdr->flags & GRE_ROUTING)
 509		return FLOW_DISSECT_RET_OUT_GOOD;
 510
 511	/* Only look inside GRE for version 0 and 1 */
 512	gre_ver = ntohs(hdr->flags & GRE_VERSION);
 513	if (gre_ver > 1)
 514		return FLOW_DISSECT_RET_OUT_GOOD;
 515
 516	*p_proto = hdr->protocol;
 517	if (gre_ver) {
 518		/* Version1 must be PPTP, and check the flags */
 519		if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 520			return FLOW_DISSECT_RET_OUT_GOOD;
 521	}
 522
 523	offset += sizeof(struct gre_base_hdr);
 524
 525	if (hdr->flags & GRE_CSUM)
 526		offset += FIELD_SIZEOF(struct gre_full_hdr, csum) +
 527			  FIELD_SIZEOF(struct gre_full_hdr, reserved1);
 528
 529	if (hdr->flags & GRE_KEY) {
 530		const __be32 *keyid;
 531		__be32 _keyid;
 532
 533		keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 534					     sizeof(_keyid),
 535					     data, *p_hlen, &_keyid);
 536		if (!keyid)
 537			return FLOW_DISSECT_RET_OUT_BAD;
 538
 539		if (dissector_uses_key(flow_dissector,
 540				       FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 541			key_keyid = skb_flow_dissector_target(flow_dissector,
 542							      FLOW_DISSECTOR_KEY_GRE_KEYID,
 543							      target_container);
 544			if (gre_ver == 0)
 545				key_keyid->keyid = *keyid;
 546			else
 547				key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 548		}
 549		offset += FIELD_SIZEOF(struct gre_full_hdr, key);
 550	}
 551
 552	if (hdr->flags & GRE_SEQ)
 553		offset += FIELD_SIZEOF(struct pptp_gre_header, seq);
 554
 555	if (gre_ver == 0) {
 556		if (*p_proto == htons(ETH_P_TEB)) {
 557			const struct ethhdr *eth;
 558			struct ethhdr _eth;
 559
 560			eth = __skb_header_pointer(skb, *p_nhoff + offset,
 561						   sizeof(_eth),
 562						   data, *p_hlen, &_eth);
 563			if (!eth)
 564				return FLOW_DISSECT_RET_OUT_BAD;
 565			*p_proto = eth->h_proto;
 566			offset += sizeof(*eth);
 567
 568			/* Cap headers that we access via pointers at the
 569			 * end of the Ethernet header as our maximum alignment
 570			 * at that point is only 2 bytes.
 571			 */
 572			if (NET_IP_ALIGN)
 573				*p_hlen = *p_nhoff + offset;
 574		}
 575	} else { /* version 1, must be PPTP */
 576		u8 _ppp_hdr[PPP_HDRLEN];
 577		u8 *ppp_hdr;
 578
 579		if (hdr->flags & GRE_ACK)
 580			offset += FIELD_SIZEOF(struct pptp_gre_header, ack);
 581
 582		ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 583					       sizeof(_ppp_hdr),
 584					       data, *p_hlen, _ppp_hdr);
 585		if (!ppp_hdr)
 586			return FLOW_DISSECT_RET_OUT_BAD;
 587
 588		switch (PPP_PROTOCOL(ppp_hdr)) {
 589		case PPP_IP:
 590			*p_proto = htons(ETH_P_IP);
 591			break;
 592		case PPP_IPV6:
 593			*p_proto = htons(ETH_P_IPV6);
 594			break;
 595		default:
 596			/* Could probably catch some more like MPLS */
 597			break;
 598		}
 599
 600		offset += PPP_HDRLEN;
 601	}
 602
 603	*p_nhoff += offset;
 604	key_control->flags |= FLOW_DIS_ENCAPSULATION;
 605	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 606		return FLOW_DISSECT_RET_OUT_GOOD;
 607
 608	return FLOW_DISSECT_RET_PROTO_AGAIN;
 609}
 610
 611/**
 612 * __skb_flow_dissect_batadv() - dissect batman-adv header
 613 * @skb: sk_buff to with the batman-adv header
 614 * @key_control: flow dissectors control key
 615 * @data: raw buffer pointer to the packet, if NULL use skb->data
 616 * @p_proto: pointer used to update the protocol to process next
 617 * @p_nhoff: pointer used to update inner network header offset
 618 * @hlen: packet header length
 619 * @flags: any combination of FLOW_DISSECTOR_F_*
 620 *
 621 * ETH_P_BATMAN packets are tried to be dissected. Only
 622 * &struct batadv_unicast packets are actually processed because they contain an
 623 * inner ethernet header and are usually followed by actual network header. This
 624 * allows the flow dissector to continue processing the packet.
 625 *
 626 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 627 *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 628 *  otherwise FLOW_DISSECT_RET_OUT_BAD
 629 */
 630static enum flow_dissect_ret
 631__skb_flow_dissect_batadv(const struct sk_buff *skb,
 632			  struct flow_dissector_key_control *key_control,
 633			  void *data, __be16 *p_proto, int *p_nhoff, int hlen,
 634			  unsigned int flags)
 635{
 636	struct {
 637		struct batadv_unicast_packet batadv_unicast;
 638		struct ethhdr eth;
 639	} *hdr, _hdr;
 640
 641	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 642				   &_hdr);
 643	if (!hdr)
 644		return FLOW_DISSECT_RET_OUT_BAD;
 645
 646	if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 647		return FLOW_DISSECT_RET_OUT_BAD;
 648
 649	if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 650		return FLOW_DISSECT_RET_OUT_BAD;
 651
 652	*p_proto = hdr->eth.h_proto;
 653	*p_nhoff += sizeof(*hdr);
 654
 655	key_control->flags |= FLOW_DIS_ENCAPSULATION;
 656	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 657		return FLOW_DISSECT_RET_OUT_GOOD;
 658
 659	return FLOW_DISSECT_RET_PROTO_AGAIN;
 660}
 661
 662static void
 663__skb_flow_dissect_tcp(const struct sk_buff *skb,
 664		       struct flow_dissector *flow_dissector,
 665		       void *target_container, void *data, int thoff, int hlen)
 666{
 667	struct flow_dissector_key_tcp *key_tcp;
 668	struct tcphdr *th, _th;
 669
 670	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 671		return;
 672
 673	th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 674	if (!th)
 675		return;
 676
 677	if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 678		return;
 679
 680	key_tcp = skb_flow_dissector_target(flow_dissector,
 681					    FLOW_DISSECTOR_KEY_TCP,
 682					    target_container);
 683	key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 684}
 685
 686static void
 687__skb_flow_dissect_ipv4(const struct sk_buff *skb,
 688			struct flow_dissector *flow_dissector,
 689			void *target_container, void *data, const struct iphdr *iph)
 690{
 691	struct flow_dissector_key_ip *key_ip;
 692
 693	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 694		return;
 695
 696	key_ip = skb_flow_dissector_target(flow_dissector,
 697					   FLOW_DISSECTOR_KEY_IP,
 698					   target_container);
 699	key_ip->tos = iph->tos;
 700	key_ip->ttl = iph->ttl;
 701}
 702
 703static void
 704__skb_flow_dissect_ipv6(const struct sk_buff *skb,
 705			struct flow_dissector *flow_dissector,
 706			void *target_container, void *data, const struct ipv6hdr *iph)
 707{
 708	struct flow_dissector_key_ip *key_ip;
 709
 710	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 711		return;
 712
 713	key_ip = skb_flow_dissector_target(flow_dissector,
 714					   FLOW_DISSECTOR_KEY_IP,
 715					   target_container);
 716	key_ip->tos = ipv6_get_dsfield(iph);
 717	key_ip->ttl = iph->hop_limit;
 718}
 719
 720/* Maximum number of protocol headers that can be parsed in
 721 * __skb_flow_dissect
 722 */
 723#define MAX_FLOW_DISSECT_HDRS	15
 724
 725static bool skb_flow_dissect_allowed(int *num_hdrs)
 726{
 727	++*num_hdrs;
 728
 729	return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 730}
 731
 732static 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
 795bool 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 */
 845bool __skb_flow_dissect(const struct net *net,
 846			const struct sk_buff *skb,
 847			struct flow_dissector *flow_dissector,
 848			void *target_container,
 849			void *data, __be16 proto, int nhoff, int hlen,
 850			unsigned int flags)
 851{
 852	struct flow_dissector_key_control *key_control;
 853	struct flow_dissector_key_basic *key_basic;
 854	struct flow_dissector_key_addrs *key_addrs;
 855	struct flow_dissector_key_ports *key_ports;
 856	struct flow_dissector_key_icmp *key_icmp;
 857	struct flow_dissector_key_tags *key_tags;
 858	struct flow_dissector_key_vlan *key_vlan;
 859	struct bpf_prog *attached = NULL;
 860	enum flow_dissect_ret fdret;
 861	enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
 862	int num_hdrs = 0;
 863	u8 ip_proto = 0;
 864	bool ret;
 865
 866	if (!data) {
 867		data = skb->data;
 868		proto = skb_vlan_tag_present(skb) ?
 869			 skb->vlan_proto : skb->protocol;
 870		nhoff = skb_network_offset(skb);
 871		hlen = skb_headlen(skb);
 872#if IS_ENABLED(CONFIG_NET_DSA)
 873		if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
 874			const struct dsa_device_ops *ops;
 875			int offset;
 876
 877			ops = skb->dev->dsa_ptr->tag_ops;
 878			if (ops->flow_dissect &&
 879			    !ops->flow_dissect(skb, &proto, &offset)) {
 880				hlen -= offset;
 881				nhoff += offset;
 882			}
 883		}
 884#endif
 885	}
 886
 887	/* It is ensured by skb_flow_dissector_init() that control key will
 888	 * be always present.
 889	 */
 890	key_control = skb_flow_dissector_target(flow_dissector,
 891						FLOW_DISSECTOR_KEY_CONTROL,
 892						target_container);
 893
 894	/* It is ensured by skb_flow_dissector_init() that basic key will
 895	 * be always present.
 896	 */
 897	key_basic = skb_flow_dissector_target(flow_dissector,
 898					      FLOW_DISSECTOR_KEY_BASIC,
 899					      target_container);
 900
 901	if (skb) {
 902		if (!net) {
 903			if (skb->dev)
 904				net = dev_net(skb->dev);
 905			else if (skb->sk)
 906				net = sock_net(skb->sk);
 907		}
 908	}
 909
 910	WARN_ON_ONCE(!net);
 911	if (net) {
 912		rcu_read_lock();
 913		attached = rcu_dereference(net->flow_dissector_prog);
 914
 915		if (attached) {
 916			struct bpf_flow_keys flow_keys;
 917			struct bpf_flow_dissector ctx = {
 918				.flow_keys = &flow_keys,
 919				.data = data,
 920				.data_end = data + hlen,
 921			};
 922			__be16 n_proto = proto;
 923
 924			if (skb) {
 925				ctx.skb = skb;
 926				/* we can't use 'proto' in the skb case
 927				 * because it might be set to skb->vlan_proto
 928				 * which has been pulled from the data
 929				 */
 930				n_proto = skb->protocol;
 931			}
 932
 933			ret = bpf_flow_dissect(attached, &ctx, n_proto, nhoff,
 934					       hlen, flags);
 935			__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
 936						 target_container);
 937			rcu_read_unlock();
 938			return ret;
 939		}
 940		rcu_read_unlock();
 941	}
 942
 943	if (dissector_uses_key(flow_dissector,
 944			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
 945		struct ethhdr *eth = eth_hdr(skb);
 946		struct flow_dissector_key_eth_addrs *key_eth_addrs;
 947
 948		key_eth_addrs = skb_flow_dissector_target(flow_dissector,
 949							  FLOW_DISSECTOR_KEY_ETH_ADDRS,
 950							  target_container);
 951		memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
 952	}
 953
 954proto_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
1202ip_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
1337out_good:
1338	ret = true;
1339
1340out:
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
1347out_bad:
1348	ret = false;
1349	goto out;
1350}
1351EXPORT_SYMBOL(__skb_flow_dissect);
1352
1353static siphash_key_t hashrnd __read_mostly;
1354static __always_inline void __flow_hash_secret_init(void)
1355{
1356	net_get_random_once(&hashrnd, sizeof(hashrnd));
1357}
1358
1359static 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
1365static 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
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}
1399EXPORT_SYMBOL(flow_get_u32_src);
1400
1401__be32 flow_get_u32_dst(const struct flow_keys *flow)
1402{
1403	switch (flow->control.addr_type) {
1404	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1405		return flow->addrs.v4addrs.dst;
1406	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1407		return (__force __be32)ipv6_addr_hash(
1408			&flow->addrs.v6addrs.dst);
1409	default:
1410		return 0;
1411	}
1412}
1413EXPORT_SYMBOL(flow_get_u32_dst);
1414
1415static 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
1448static 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
1463u32 flow_hash_from_keys(struct flow_keys *keys)
1464{
1465	__flow_hash_secret_init();
1466	return __flow_hash_from_keys(keys, &hashrnd);
1467}
1468EXPORT_SYMBOL(flow_hash_from_keys);
1469
1470static 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
1480struct _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
1489void 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}
1505EXPORT_SYMBOL(make_flow_keys_digest);
1506
1507static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1508
1509u32 __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}
1522EXPORT_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 */
1533void __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}
1544EXPORT_SYMBOL(__skb_get_hash);
1545
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}
1553EXPORT_SYMBOL(skb_get_hash_perturb);
1554
1555u32 __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 */
1615u32 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
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}
1643EXPORT_SYMBOL(__get_hash_from_flowi6);
1644
1645static 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
1684static 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
1707static 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
1718struct flow_dissector flow_keys_dissector __read_mostly;
1719EXPORT_SYMBOL(flow_keys_dissector);
1720
1721struct flow_dissector flow_keys_basic_dissector __read_mostly;
1722EXPORT_SYMBOL(flow_keys_basic_dissector);
1723
1724static 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
1738core_initcall(init_default_flow_dissectors);