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);