flow_dissector.c 37.6 KB
Newer Older
1
#include <linux/kernel.h>
E
Eric Dumazet 已提交
2
#include <linux/skbuff.h>
3
#include <linux/export.h>
E
Eric Dumazet 已提交
4 5 6
#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/if_vlan.h>
7
#include <net/dsa.h>
S
Simon Horman 已提交
8
#include <net/dst_metadata.h>
E
Eric Dumazet 已提交
9
#include <net/ip.h>
E
Eric Dumazet 已提交
10
#include <net/ipv6.h>
11 12
#include <net/gre.h>
#include <net/pptp.h>
13
#include <net/tipc.h>
14 15 16 17
#include <linux/igmp.h>
#include <linux/icmp.h>
#include <linux/sctp.h>
#include <linux/dccp.h>
E
Eric Dumazet 已提交
18 19 20
#include <linux/if_tunnel.h>
#include <linux/if_pppox.h>
#include <linux/ppp_defs.h>
21
#include <linux/stddef.h>
22
#include <linux/if_ether.h>
23
#include <linux/mpls.h>
24
#include <linux/tcp.h>
25
#include <net/flow_dissector.h>
26
#include <scsi/fc/fc_fcoe.h>
27
#include <uapi/linux/batadv_packet.h>
E
Eric Dumazet 已提交
28

29 30
static void dissector_set_key(struct flow_dissector *flow_dissector,
			      enum flow_dissector_key_id key_id)
31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47
{
	flow_dissector->used_keys |= (1 << key_id);
}

void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
			     const struct flow_dissector_key *key,
			     unsigned int key_count)
{
	unsigned int i;

	memset(flow_dissector, 0, sizeof(*flow_dissector));

	for (i = 0; i < key_count; i++, key++) {
		/* User should make sure that every key target offset is withing
		 * boundaries of unsigned short.
		 */
		BUG_ON(key->offset > USHRT_MAX);
48 49
		BUG_ON(dissector_uses_key(flow_dissector,
					  key->key_id));
50

51
		dissector_set_key(flow_dissector, key->key_id);
52 53 54
		flow_dissector->offset[key->key_id] = key->offset;
	}

55 56
	/* Ensure that the dissector always includes control and basic key.
	 * That way we are able to avoid handling lack of these in fast path.
57
	 */
58 59 60 61
	BUG_ON(!dissector_uses_key(flow_dissector,
				   FLOW_DISSECTOR_KEY_CONTROL));
	BUG_ON(!dissector_uses_key(flow_dissector,
				   FLOW_DISSECTOR_KEY_BASIC));
62 63 64
}
EXPORT_SYMBOL(skb_flow_dissector_init);

S
Simon Horman 已提交
65 66 67 68 69 70 71 72 73 74
/**
 * skb_flow_get_be16 - extract be16 entity
 * @skb: sk_buff to extract from
 * @poff: offset to extract at
 * @data: raw buffer pointer to the packet
 * @hlen: packet header length
 *
 * The function will try to retrieve a be32 entity at
 * offset poff
 */
75 76
static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
				void *data, int hlen)
S
Simon Horman 已提交
77 78 79 80 81 82 83 84 85 86
{
	__be16 *u, _u;

	u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
	if (u)
		return *u;

	return 0;
}

87
/**
88 89
 * __skb_flow_get_ports - extract the upper layer ports and return them
 * @skb: sk_buff to extract the ports from
90 91
 * @thoff: transport header offset
 * @ip_proto: protocol for which to get port offset
92 93
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
94 95 96 97
 *
 * The function will try to retrieve the ports at offset thoff + poff where poff
 * is the protocol port offset returned from proto_ports_offset
 */
98 99
__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
			    void *data, int hlen)
100 101 102
{
	int poff = proto_ports_offset(ip_proto);

103 104 105 106 107
	if (!data) {
		data = skb->data;
		hlen = skb_headlen(skb);
	}

108 109 110
	if (poff >= 0) {
		__be32 *ports, _ports;

111 112
		ports = __skb_header_pointer(skb, thoff + poff,
					     sizeof(_ports), data, hlen, &_ports);
113 114 115 116 117 118
		if (ports)
			return *ports;
	}

	return 0;
}
119
EXPORT_SYMBOL(__skb_flow_get_ports);
120

S
Simon Horman 已提交
121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136
static void
skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
				   struct flow_dissector *flow_dissector,
				   void *target_container)
{
	struct flow_dissector_key_control *ctrl;

	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
		return;

	ctrl = skb_flow_dissector_target(flow_dissector,
					 FLOW_DISSECTOR_KEY_ENC_CONTROL,
					 target_container);
	ctrl->addr_type = type;
}

137 138 139 140
void
skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
			     struct flow_dissector *flow_dissector,
			     void *target_container)
S
Simon Horman 已提交
141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215
{
	struct ip_tunnel_info *info;
	struct ip_tunnel_key *key;

	/* A quick check to see if there might be something to do. */
	if (!dissector_uses_key(flow_dissector,
				FLOW_DISSECTOR_KEY_ENC_KEYID) &&
	    !dissector_uses_key(flow_dissector,
				FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
	    !dissector_uses_key(flow_dissector,
				FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
	    !dissector_uses_key(flow_dissector,
				FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
	    !dissector_uses_key(flow_dissector,
				FLOW_DISSECTOR_KEY_ENC_PORTS))
		return;

	info = skb_tunnel_info(skb);
	if (!info)
		return;

	key = &info->key;

	switch (ip_tunnel_info_af(info)) {
	case AF_INET:
		skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
						   flow_dissector,
						   target_container);
		if (dissector_uses_key(flow_dissector,
				       FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
			struct flow_dissector_key_ipv4_addrs *ipv4;

			ipv4 = skb_flow_dissector_target(flow_dissector,
							 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
							 target_container);
			ipv4->src = key->u.ipv4.src;
			ipv4->dst = key->u.ipv4.dst;
		}
		break;
	case AF_INET6:
		skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
						   flow_dissector,
						   target_container);
		if (dissector_uses_key(flow_dissector,
				       FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
			struct flow_dissector_key_ipv6_addrs *ipv6;

			ipv6 = skb_flow_dissector_target(flow_dissector,
							 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
							 target_container);
			ipv6->src = key->u.ipv6.src;
			ipv6->dst = key->u.ipv6.dst;
		}
		break;
	}

	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
		struct flow_dissector_key_keyid *keyid;

		keyid = skb_flow_dissector_target(flow_dissector,
						  FLOW_DISSECTOR_KEY_ENC_KEYID,
						  target_container);
		keyid->keyid = tunnel_id_to_key32(key->tun_id);
	}

	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
		struct flow_dissector_key_ports *tp;

		tp = skb_flow_dissector_target(flow_dissector,
					       FLOW_DISSECTOR_KEY_ENC_PORTS,
					       target_container);
		tp->src = key->tp_src;
		tp->dst = key->tp_dst;
	}
}
216
EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
S
Simon Horman 已提交
217

218 219 220 221 222 223 224
static enum flow_dissect_ret
__skb_flow_dissect_mpls(const struct sk_buff *skb,
			struct flow_dissector *flow_dissector,
			void *target_container, void *data, int nhoff, int hlen)
{
	struct flow_dissector_key_keyid *key_keyid;
	struct mpls_label *hdr, _hdr[2];
225
	u32 entry, label;
226 227

	if (!dissector_uses_key(flow_dissector,
228 229
				FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
	    !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
230 231 232 233 234 235 236
		return FLOW_DISSECT_RET_OUT_GOOD;

	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
				   hlen, &_hdr);
	if (!hdr)
		return FLOW_DISSECT_RET_OUT_BAD;

237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255
	entry = ntohl(hdr[0].entry);
	label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;

	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
		struct flow_dissector_key_mpls *key_mpls;

		key_mpls = skb_flow_dissector_target(flow_dissector,
						     FLOW_DISSECTOR_KEY_MPLS,
						     target_container);
		key_mpls->mpls_label = label;
		key_mpls->mpls_ttl = (entry & MPLS_LS_TTL_MASK)
					>> MPLS_LS_TTL_SHIFT;
		key_mpls->mpls_tc = (entry & MPLS_LS_TC_MASK)
					>> MPLS_LS_TC_SHIFT;
		key_mpls->mpls_bos = (entry & MPLS_LS_S_MASK)
					>> MPLS_LS_S_SHIFT;
	}

	if (label == MPLS_LABEL_ENTROPY) {
256 257 258 259 260 261 262 263
		key_keyid = skb_flow_dissector_target(flow_dissector,
						      FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
						      target_container);
		key_keyid->keyid = hdr[1].entry & htonl(MPLS_LS_LABEL_MASK);
	}
	return FLOW_DISSECT_RET_OUT_GOOD;
}

264 265 266 267 268 269 270 271 272 273 274 275 276
static enum flow_dissect_ret
__skb_flow_dissect_arp(const struct sk_buff *skb,
		       struct flow_dissector *flow_dissector,
		       void *target_container, void *data, int nhoff, int hlen)
{
	struct flow_dissector_key_arp *key_arp;
	struct {
		unsigned char ar_sha[ETH_ALEN];
		unsigned char ar_sip[4];
		unsigned char ar_tha[ETH_ALEN];
		unsigned char ar_tip[4];
	} *arp_eth, _arp_eth;
	const struct arphdr *arp;
277
	struct arphdr _arp;
278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318

	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
		return FLOW_DISSECT_RET_OUT_GOOD;

	arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
				   hlen, &_arp);
	if (!arp)
		return FLOW_DISSECT_RET_OUT_BAD;

	if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
	    arp->ar_pro != htons(ETH_P_IP) ||
	    arp->ar_hln != ETH_ALEN ||
	    arp->ar_pln != 4 ||
	    (arp->ar_op != htons(ARPOP_REPLY) &&
	     arp->ar_op != htons(ARPOP_REQUEST)))
		return FLOW_DISSECT_RET_OUT_BAD;

	arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
				       sizeof(_arp_eth), data,
				       hlen, &_arp_eth);
	if (!arp_eth)
		return FLOW_DISSECT_RET_OUT_BAD;

	key_arp = skb_flow_dissector_target(flow_dissector,
					    FLOW_DISSECTOR_KEY_ARP,
					    target_container);

	memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
	memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));

	/* Only store the lower byte of the opcode;
	 * this covers ARPOP_REPLY and ARPOP_REQUEST.
	 */
	key_arp->op = ntohs(arp->ar_op) & 0xff;

	ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
	ether_addr_copy(key_arp->tha, arp_eth->ar_tha);

	return FLOW_DISSECT_RET_OUT_GOOD;
}

319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437
static enum flow_dissect_ret
__skb_flow_dissect_gre(const struct sk_buff *skb,
		       struct flow_dissector_key_control *key_control,
		       struct flow_dissector *flow_dissector,
		       void *target_container, void *data,
		       __be16 *p_proto, int *p_nhoff, int *p_hlen,
		       unsigned int flags)
{
	struct flow_dissector_key_keyid *key_keyid;
	struct gre_base_hdr *hdr, _hdr;
	int offset = 0;
	u16 gre_ver;

	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
				   data, *p_hlen, &_hdr);
	if (!hdr)
		return FLOW_DISSECT_RET_OUT_BAD;

	/* Only look inside GRE without routing */
	if (hdr->flags & GRE_ROUTING)
		return FLOW_DISSECT_RET_OUT_GOOD;

	/* Only look inside GRE for version 0 and 1 */
	gre_ver = ntohs(hdr->flags & GRE_VERSION);
	if (gre_ver > 1)
		return FLOW_DISSECT_RET_OUT_GOOD;

	*p_proto = hdr->protocol;
	if (gre_ver) {
		/* Version1 must be PPTP, and check the flags */
		if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
			return FLOW_DISSECT_RET_OUT_GOOD;
	}

	offset += sizeof(struct gre_base_hdr);

	if (hdr->flags & GRE_CSUM)
		offset += sizeof(((struct gre_full_hdr *) 0)->csum) +
			  sizeof(((struct gre_full_hdr *) 0)->reserved1);

	if (hdr->flags & GRE_KEY) {
		const __be32 *keyid;
		__be32 _keyid;

		keyid = __skb_header_pointer(skb, *p_nhoff + offset,
					     sizeof(_keyid),
					     data, *p_hlen, &_keyid);
		if (!keyid)
			return FLOW_DISSECT_RET_OUT_BAD;

		if (dissector_uses_key(flow_dissector,
				       FLOW_DISSECTOR_KEY_GRE_KEYID)) {
			key_keyid = skb_flow_dissector_target(flow_dissector,
							      FLOW_DISSECTOR_KEY_GRE_KEYID,
							      target_container);
			if (gre_ver == 0)
				key_keyid->keyid = *keyid;
			else
				key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
		}
		offset += sizeof(((struct gre_full_hdr *) 0)->key);
	}

	if (hdr->flags & GRE_SEQ)
		offset += sizeof(((struct pptp_gre_header *) 0)->seq);

	if (gre_ver == 0) {
		if (*p_proto == htons(ETH_P_TEB)) {
			const struct ethhdr *eth;
			struct ethhdr _eth;

			eth = __skb_header_pointer(skb, *p_nhoff + offset,
						   sizeof(_eth),
						   data, *p_hlen, &_eth);
			if (!eth)
				return FLOW_DISSECT_RET_OUT_BAD;
			*p_proto = eth->h_proto;
			offset += sizeof(*eth);

			/* Cap headers that we access via pointers at the
			 * end of the Ethernet header as our maximum alignment
			 * at that point is only 2 bytes.
			 */
			if (NET_IP_ALIGN)
				*p_hlen = *p_nhoff + offset;
		}
	} else { /* version 1, must be PPTP */
		u8 _ppp_hdr[PPP_HDRLEN];
		u8 *ppp_hdr;

		if (hdr->flags & GRE_ACK)
			offset += sizeof(((struct pptp_gre_header *) 0)->ack);

		ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
					       sizeof(_ppp_hdr),
					       data, *p_hlen, _ppp_hdr);
		if (!ppp_hdr)
			return FLOW_DISSECT_RET_OUT_BAD;

		switch (PPP_PROTOCOL(ppp_hdr)) {
		case PPP_IP:
			*p_proto = htons(ETH_P_IP);
			break;
		case PPP_IPV6:
			*p_proto = htons(ETH_P_IPV6);
			break;
		default:
			/* Could probably catch some more like MPLS */
			break;
		}

		offset += PPP_HDRLEN;
	}

	*p_nhoff += offset;
	key_control->flags |= FLOW_DIS_ENCAPSULATION;
	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
		return FLOW_DISSECT_RET_OUT_GOOD;

438
	return FLOW_DISSECT_RET_PROTO_AGAIN;
439 440
}

441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491
/**
 * __skb_flow_dissect_batadv() - dissect batman-adv header
 * @skb: sk_buff to with the batman-adv header
 * @key_control: flow dissectors control key
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @p_proto: pointer used to update the protocol to process next
 * @p_nhoff: pointer used to update inner network header offset
 * @hlen: packet header length
 * @flags: any combination of FLOW_DISSECTOR_F_*
 *
 * ETH_P_BATMAN packets are tried to be dissected. Only
 * &struct batadv_unicast packets are actually processed because they contain an
 * inner ethernet header and are usually followed by actual network header. This
 * allows the flow dissector to continue processing the packet.
 *
 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 *  otherwise FLOW_DISSECT_RET_OUT_BAD
 */
static enum flow_dissect_ret
__skb_flow_dissect_batadv(const struct sk_buff *skb,
			  struct flow_dissector_key_control *key_control,
			  void *data, __be16 *p_proto, int *p_nhoff, int hlen,
			  unsigned int flags)
{
	struct {
		struct batadv_unicast_packet batadv_unicast;
		struct ethhdr eth;
	} *hdr, _hdr;

	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
				   &_hdr);
	if (!hdr)
		return FLOW_DISSECT_RET_OUT_BAD;

	if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
		return FLOW_DISSECT_RET_OUT_BAD;

	if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
		return FLOW_DISSECT_RET_OUT_BAD;

	*p_proto = hdr->eth.h_proto;
	*p_nhoff += sizeof(*hdr);

	key_control->flags |= FLOW_DIS_ENCAPSULATION;
	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
		return FLOW_DISSECT_RET_OUT_GOOD;

	return FLOW_DISSECT_RET_PROTO_AGAIN;
}

492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515
static void
__skb_flow_dissect_tcp(const struct sk_buff *skb,
		       struct flow_dissector *flow_dissector,
		       void *target_container, void *data, int thoff, int hlen)
{
	struct flow_dissector_key_tcp *key_tcp;
	struct tcphdr *th, _th;

	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
		return;

	th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
	if (!th)
		return;

	if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
		return;

	key_tcp = skb_flow_dissector_target(flow_dissector,
					    FLOW_DISSECTOR_KEY_TCP,
					    target_container);
	key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
}

516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549
static void
__skb_flow_dissect_ipv4(const struct sk_buff *skb,
			struct flow_dissector *flow_dissector,
			void *target_container, void *data, const struct iphdr *iph)
{
	struct flow_dissector_key_ip *key_ip;

	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
		return;

	key_ip = skb_flow_dissector_target(flow_dissector,
					   FLOW_DISSECTOR_KEY_IP,
					   target_container);
	key_ip->tos = iph->tos;
	key_ip->ttl = iph->ttl;
}

static void
__skb_flow_dissect_ipv6(const struct sk_buff *skb,
			struct flow_dissector *flow_dissector,
			void *target_container, void *data, const struct ipv6hdr *iph)
{
	struct flow_dissector_key_ip *key_ip;

	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
		return;

	key_ip = skb_flow_dissector_target(flow_dissector,
					   FLOW_DISSECTOR_KEY_IP,
					   target_container);
	key_ip->tos = ipv6_get_dsfield(iph);
	key_ip->ttl = iph->hop_limit;
}

550 551 552 553 554 555 556 557 558 559 560 561
/* Maximum number of protocol headers that can be parsed in
 * __skb_flow_dissect
 */
#define MAX_FLOW_DISSECT_HDRS	15

static bool skb_flow_dissect_allowed(int *num_hdrs)
{
	++*num_hdrs;

	return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
}

562 563 564
/**
 * __skb_flow_dissect - extract the flow_keys struct and return it
 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
565 566
 * @flow_dissector: list of keys to dissect
 * @target_container: target structure to put dissected values into
567 568 569 570 571
 * @data: raw buffer pointer to the packet, if NULL use skb->data
 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 *
572 573 574 575 576
 * The function will try to retrieve individual keys into target specified
 * by flow_dissector from either the skbuff or a raw buffer specified by the
 * rest parameters.
 *
 * Caller must take care of zeroing target container memory.
577
 */
578 579 580
bool __skb_flow_dissect(const struct sk_buff *skb,
			struct flow_dissector *flow_dissector,
			void *target_container,
581 582
			void *data, __be16 proto, int nhoff, int hlen,
			unsigned int flags)
E
Eric Dumazet 已提交
583
{
584
	struct flow_dissector_key_control *key_control;
585 586 587
	struct flow_dissector_key_basic *key_basic;
	struct flow_dissector_key_addrs *key_addrs;
	struct flow_dissector_key_ports *key_ports;
S
Simon Horman 已提交
588
	struct flow_dissector_key_icmp *key_icmp;
T
Tom Herbert 已提交
589
	struct flow_dissector_key_tags *key_tags;
590
	struct flow_dissector_key_vlan *key_vlan;
591
	enum flow_dissect_ret fdret;
592
	enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
593
	int num_hdrs = 0;
594
	u8 ip_proto = 0;
595
	bool ret;
E
Eric Dumazet 已提交
596

597 598
	if (!data) {
		data = skb->data;
599 600
		proto = skb_vlan_tag_present(skb) ?
			 skb->vlan_proto : skb->protocol;
601
		nhoff = skb_network_offset(skb);
602
		hlen = skb_headlen(skb);
603
#if IS_ENABLED(CONFIG_NET_DSA)
604
		if (unlikely(skb->dev && netdev_uses_dsa(skb->dev))) {
605 606 607 608 609 610 611 612 613 614
			const struct dsa_device_ops *ops;
			int offset;

			ops = skb->dev->dsa_ptr->tag_ops;
			if (ops->flow_dissect &&
			    !ops->flow_dissect(skb, &proto, &offset)) {
				hlen -= offset;
				nhoff += offset;
			}
		}
615
#endif
616 617
	}

618 619 620 621 622 623 624
	/* It is ensured by skb_flow_dissector_init() that control key will
	 * be always present.
	 */
	key_control = skb_flow_dissector_target(flow_dissector,
						FLOW_DISSECTOR_KEY_CONTROL,
						target_container);

625 626 627 628 629 630
	/* It is ensured by skb_flow_dissector_init() that basic key will
	 * be always present.
	 */
	key_basic = skb_flow_dissector_target(flow_dissector,
					      FLOW_DISSECTOR_KEY_BASIC,
					      target_container);
E
Eric Dumazet 已提交
631

632 633
	if (dissector_uses_key(flow_dissector,
			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
634 635 636 637 638 639 640 641 642
		struct ethhdr *eth = eth_hdr(skb);
		struct flow_dissector_key_eth_addrs *key_eth_addrs;

		key_eth_addrs = skb_flow_dissector_target(flow_dissector,
							  FLOW_DISSECTOR_KEY_ETH_ADDRS,
							  target_container);
		memcpy(key_eth_addrs, &eth->h_dest, sizeof(*key_eth_addrs));
	}

643
proto_again:
644 645
	fdret = FLOW_DISSECT_RET_CONTINUE;

E
Eric Dumazet 已提交
646
	switch (proto) {
647
	case htons(ETH_P_IP): {
E
Eric Dumazet 已提交
648 649
		const struct iphdr *iph;
		struct iphdr _iph;
650

651
		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
652 653 654 655 656
		if (!iph || iph->ihl < 5) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}

657
		nhoff += iph->ihl * 4;
E
Eric Dumazet 已提交
658

659 660
		ip_proto = iph->protocol;

661 662 663 664 665 666 667 668 669 670
		if (dissector_uses_key(flow_dissector,
				       FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
			key_addrs = skb_flow_dissector_target(flow_dissector,
							      FLOW_DISSECTOR_KEY_IPV4_ADDRS,
							      target_container);

			memcpy(&key_addrs->v4addrs, &iph->saddr,
			       sizeof(key_addrs->v4addrs));
			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
		}
671 672

		if (ip_is_fragment(iph)) {
673
			key_control->flags |= FLOW_DIS_IS_FRAGMENT;
674 675

			if (iph->frag_off & htons(IP_OFFSET)) {
676 677
				fdret = FLOW_DISSECT_RET_OUT_GOOD;
				break;
678
			} else {
679
				key_control->flags |= FLOW_DIS_FIRST_FRAG;
680 681 682 683 684
				if (!(flags &
				      FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
					fdret = FLOW_DISSECT_RET_OUT_GOOD;
					break;
				}
685 686 687
			}
		}

688 689 690
		__skb_flow_dissect_ipv4(skb, flow_dissector,
					target_container, data, iph);

691 692 693 694
		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
			fdret = FLOW_DISSECT_RET_OUT_GOOD;
			break;
		}
695

E
Eric Dumazet 已提交
696 697
		break;
	}
698
	case htons(ETH_P_IPV6): {
E
Eric Dumazet 已提交
699 700
		const struct ipv6hdr *iph;
		struct ipv6hdr _iph;
701

702
		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
703 704 705 706
		if (!iph) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}
E
Eric Dumazet 已提交
707 708 709

		ip_proto = iph->nexthdr;
		nhoff += sizeof(struct ipv6hdr);
710

711 712
		if (dissector_uses_key(flow_dissector,
				       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
713 714 715
			key_addrs = skb_flow_dissector_target(flow_dissector,
							      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
							      target_container);
716

717 718
			memcpy(&key_addrs->v6addrs, &iph->saddr,
			       sizeof(key_addrs->v6addrs));
719
			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
720
		}
721

722 723 724 725 726 727
		if ((dissector_uses_key(flow_dissector,
					FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
		     (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
		    ip6_flowlabel(iph)) {
			__be32 flow_label = ip6_flowlabel(iph);

728 729
			if (dissector_uses_key(flow_dissector,
					       FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
730 731 732 733
				key_tags = skb_flow_dissector_target(flow_dissector,
								     FLOW_DISSECTOR_KEY_FLOW_LABEL,
								     target_container);
				key_tags->flow_label = ntohl(flow_label);
734
			}
735 736 737 738
			if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
				fdret = FLOW_DISSECT_RET_OUT_GOOD;
				break;
			}
739 740
		}

741 742 743
		__skb_flow_dissect_ipv6(skb, flow_dissector,
					target_container, data, iph);

744
		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
745
			fdret = FLOW_DISSECT_RET_OUT_GOOD;
746

E
Eric Dumazet 已提交
747 748
		break;
	}
749 750
	case htons(ETH_P_8021AD):
	case htons(ETH_P_8021Q): {
751
		const struct vlan_hdr *vlan = NULL;
752
		struct vlan_hdr _vlan;
753
		__be16 saved_vlan_tpid = proto;
E
Eric Dumazet 已提交
754

755 756
		if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
		    skb && skb_vlan_tag_present(skb)) {
757
			proto = skb->protocol;
758
		} else {
759 760
			vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
						    data, hlen, &_vlan);
761 762 763 764 765
			if (!vlan) {
				fdret = FLOW_DISSECT_RET_OUT_BAD;
				break;
			}

766 767 768
			proto = vlan->h_vlan_encapsulated_proto;
			nhoff += sizeof(*vlan);
		}
E
Eric Dumazet 已提交
769

770 771 772 773 774 775 776 777 778 779
		if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
			dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
		} else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
			dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
		} else {
			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
			break;
		}

		if (dissector_uses_key(flow_dissector, dissector_vlan)) {
780
			key_vlan = skb_flow_dissector_target(flow_dissector,
781
							     dissector_vlan,
T
Tom Herbert 已提交
782 783
							     target_container);

784
			if (!vlan) {
785 786 787 788 789
				key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
				key_vlan->vlan_priority =
					(skb_vlan_tag_get_prio(skb) >> VLAN_PRIO_SHIFT);
			} else {
				key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
790
					VLAN_VID_MASK;
791 792 793 794
				key_vlan->vlan_priority =
					(ntohs(vlan->h_vlan_TCI) &
					 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
			}
795
			key_vlan->vlan_tpid = saved_vlan_tpid;
T
Tom Herbert 已提交
796 797
		}

798 799
		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
		break;
E
Eric Dumazet 已提交
800
	}
801
	case htons(ETH_P_PPP_SES): {
E
Eric Dumazet 已提交
802 803 804 805
		struct {
			struct pppoe_hdr hdr;
			__be16 proto;
		} *hdr, _hdr;
806
		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
807 808 809 810 811
		if (!hdr) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}

E
Eric Dumazet 已提交
812 813 814
		proto = hdr->proto;
		nhoff += PPPOE_SES_HLEN;
		switch (proto) {
815
		case htons(PPP_IP):
816 817 818
			proto = htons(ETH_P_IP);
			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
			break;
819
		case htons(PPP_IPV6):
820 821 822
			proto = htons(ETH_P_IPV6);
			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
			break;
E
Eric Dumazet 已提交
823
		default:
824 825
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
E
Eric Dumazet 已提交
826
		}
827
		break;
E
Eric Dumazet 已提交
828
	}
E
Erik Hugne 已提交
829
	case htons(ETH_P_TIPC): {
830 831 832 833
		struct tipc_basic_hdr *hdr, _hdr;

		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
					   data, hlen, &_hdr);
834 835 836 837
		if (!hdr) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}
838

839
		if (dissector_uses_key(flow_dissector,
840
				       FLOW_DISSECTOR_KEY_TIPC)) {
841
			key_addrs = skb_flow_dissector_target(flow_dissector,
842
							      FLOW_DISSECTOR_KEY_TIPC,
843
							      target_container);
844 845
			key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
			key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
846
		}
847 848
		fdret = FLOW_DISSECT_RET_OUT_GOOD;
		break;
E
Erik Hugne 已提交
849
	}
850 851

	case htons(ETH_P_MPLS_UC):
852
	case htons(ETH_P_MPLS_MC):
853
		fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
854
						target_container, data,
855 856
						nhoff, hlen);
		break;
857
	case htons(ETH_P_FCOE):
858 859 860 861
		if ((hlen - nhoff) < FCOE_HEADER_LEN) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}
862 863

		nhoff += FCOE_HEADER_LEN;
864 865
		fdret = FLOW_DISSECT_RET_OUT_GOOD;
		break;
S
Simon Horman 已提交
866 867

	case htons(ETH_P_ARP):
868
	case htons(ETH_P_RARP):
869
		fdret = __skb_flow_dissect_arp(skb, flow_dissector,
870
					       target_container, data,
871 872 873
					       nhoff, hlen);
		break;

874 875 876 877 878
	case htons(ETH_P_BATMAN):
		fdret = __skb_flow_dissect_batadv(skb, key_control, data,
						  &proto, &nhoff, hlen, flags);
		break;

879 880 881 882 883 884 885 886 887 888
	default:
		fdret = FLOW_DISSECT_RET_OUT_BAD;
		break;
	}

	/* Process result of proto processing */
	switch (fdret) {
	case FLOW_DISSECT_RET_OUT_GOOD:
		goto out_good;
	case FLOW_DISSECT_RET_PROTO_AGAIN:
889 890 891
		if (skb_flow_dissect_allowed(&num_hdrs))
			goto proto_again;
		goto out_good;
892 893 894 895
	case FLOW_DISSECT_RET_CONTINUE:
	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
		break;
	case FLOW_DISSECT_RET_OUT_BAD:
E
Eric Dumazet 已提交
896
	default:
897
		goto out_bad;
E
Eric Dumazet 已提交
898 899
	}

900
ip_proto_again:
901 902
	fdret = FLOW_DISSECT_RET_CONTINUE;

E
Eric Dumazet 已提交
903
	switch (ip_proto) {
904
	case IPPROTO_GRE:
905
		fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
906
					       target_container, data,
907 908 909
					       &proto, &nhoff, &hlen, flags);
		break;

910 911 912 913 914 915 916 917 918 919
	case NEXTHDR_HOP:
	case NEXTHDR_ROUTING:
	case NEXTHDR_DEST: {
		u8 _opthdr[2], *opthdr;

		if (proto != htons(ETH_P_IPV6))
			break;

		opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
					      data, hlen, &_opthdr);
920 921 922 923
		if (!opthdr) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}
924

925 926
		ip_proto = opthdr[0];
		nhoff += (opthdr[1] + 1) << 3;
927

928 929
		fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
		break;
930
	}
931 932 933 934 935 936 937 938 939
	case NEXTHDR_FRAGMENT: {
		struct frag_hdr _fh, *fh;

		if (proto != htons(ETH_P_IPV6))
			break;

		fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
					  data, hlen, &_fh);

940 941 942 943
		if (!fh) {
			fdret = FLOW_DISSECT_RET_OUT_BAD;
			break;
		}
944

945
		key_control->flags |= FLOW_DIS_IS_FRAGMENT;
946 947

		nhoff += sizeof(_fh);
948
		ip_proto = fh->nexthdr;
949 950

		if (!(fh->frag_off & htons(IP6_OFFSET))) {
951
			key_control->flags |= FLOW_DIS_FIRST_FRAG;
952 953 954 955
			if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
				fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
				break;
			}
956
		}
957 958 959

		fdret = FLOW_DISSECT_RET_OUT_GOOD;
		break;
960
	}
E
Eric Dumazet 已提交
961
	case IPPROTO_IPIP:
T
Tom Herbert 已提交
962
		proto = htons(ETH_P_IP);
963

964
		key_control->flags |= FLOW_DIS_ENCAPSULATION;
965 966 967 968 969 970 971
		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
			fdret = FLOW_DISSECT_RET_OUT_GOOD;
			break;
		}

		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
		break;
972

973 974
	case IPPROTO_IPV6:
		proto = htons(ETH_P_IPV6);
975

976
		key_control->flags |= FLOW_DIS_ENCAPSULATION;
977 978 979 980 981 982 983 984
		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
			fdret = FLOW_DISSECT_RET_OUT_GOOD;
			break;
		}

		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
		break;

985

986 987
	case IPPROTO_MPLS:
		proto = htons(ETH_P_MPLS_UC);
988 989 990
		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
		break;

991 992 993 994
	case IPPROTO_TCP:
		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
				       data, nhoff, hlen);
		break;
995

E
Eric Dumazet 已提交
996 997 998 999
	default:
		break;
	}

1000 1001
	if (dissector_uses_key(flow_dissector,
			       FLOW_DISSECTOR_KEY_PORTS)) {
1002 1003 1004 1005 1006 1007
		key_ports = skb_flow_dissector_target(flow_dissector,
						      FLOW_DISSECTOR_KEY_PORTS,
						      target_container);
		key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
							data, hlen);
	}
1008

S
Simon Horman 已提交
1009 1010 1011 1012 1013 1014 1015 1016
	if (dissector_uses_key(flow_dissector,
			       FLOW_DISSECTOR_KEY_ICMP)) {
		key_icmp = skb_flow_dissector_target(flow_dissector,
						     FLOW_DISSECTOR_KEY_ICMP,
						     target_container);
		key_icmp->icmp = skb_flow_get_be16(skb, nhoff, data, hlen);
	}

1017 1018 1019
	/* Process result of IP proto processing */
	switch (fdret) {
	case FLOW_DISSECT_RET_PROTO_AGAIN:
1020 1021 1022
		if (skb_flow_dissect_allowed(&num_hdrs))
			goto proto_again;
		break;
1023
	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1024 1025 1026
		if (skb_flow_dissect_allowed(&num_hdrs))
			goto ip_proto_again;
		break;
1027 1028 1029 1030 1031 1032 1033 1034
	case FLOW_DISSECT_RET_OUT_GOOD:
	case FLOW_DISSECT_RET_CONTINUE:
		break;
	case FLOW_DISSECT_RET_OUT_BAD:
	default:
		goto out_bad;
	}

1035 1036 1037
out_good:
	ret = true;

1038
out:
1039
	key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1040 1041 1042 1043
	key_basic->n_proto = proto;
	key_basic->ip_proto = ip_proto;

	return ret;
1044 1045 1046 1047

out_bad:
	ret = false;
	goto out;
E
Eric Dumazet 已提交
1048
}
1049
EXPORT_SYMBOL(__skb_flow_dissect);
1050 1051

static u32 hashrnd __read_mostly;
1052 1053 1054 1055 1056
static __always_inline void __flow_hash_secret_init(void)
{
	net_get_random_once(&hashrnd, sizeof(hashrnd));
}

1057 1058
static __always_inline u32 __flow_hash_words(const u32 *words, u32 length,
					     u32 keyval)
1059 1060 1061 1062
{
	return jhash2(words, length, keyval);
}

1063
static inline const u32 *flow_keys_hash_start(const struct flow_keys *flow)
1064
{
1065 1066
	const void *p = flow;

1067
	BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
1068
	return (const u32 *)(p + FLOW_KEYS_HASH_OFFSET);
1069 1070
}

1071
static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1072
{
1073
	size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1074
	BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1075 1076 1077 1078 1079 1080 1081 1082 1083 1084
	BUILD_BUG_ON(offsetof(typeof(*flow), addrs) !=
		     sizeof(*flow) - sizeof(flow->addrs));

	switch (flow->control.addr_type) {
	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
		diff -= sizeof(flow->addrs.v4addrs);
		break;
	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
		diff -= sizeof(flow->addrs.v6addrs);
		break;
1085 1086
	case FLOW_DISSECTOR_KEY_TIPC:
		diff -= sizeof(flow->addrs.tipckey);
T
Tom Herbert 已提交
1087
		break;
1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099
	}
	return (sizeof(*flow) - diff) / sizeof(u32);
}

__be32 flow_get_u32_src(const struct flow_keys *flow)
{
	switch (flow->control.addr_type) {
	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
		return flow->addrs.v4addrs.src;
	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
		return (__force __be32)ipv6_addr_hash(
			&flow->addrs.v6addrs.src);
1100 1101
	case FLOW_DISSECTOR_KEY_TIPC:
		return flow->addrs.tipckey.key;
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152
	default:
		return 0;
	}
}
EXPORT_SYMBOL(flow_get_u32_src);

__be32 flow_get_u32_dst(const struct flow_keys *flow)
{
	switch (flow->control.addr_type) {
	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
		return flow->addrs.v4addrs.dst;
	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
		return (__force __be32)ipv6_addr_hash(
			&flow->addrs.v6addrs.dst);
	default:
		return 0;
	}
}
EXPORT_SYMBOL(flow_get_u32_dst);

static inline void __flow_hash_consistentify(struct flow_keys *keys)
{
	int addr_diff, i;

	switch (keys->control.addr_type) {
	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
		addr_diff = (__force u32)keys->addrs.v4addrs.dst -
			    (__force u32)keys->addrs.v4addrs.src;
		if ((addr_diff < 0) ||
		    (addr_diff == 0 &&
		     ((__force u16)keys->ports.dst <
		      (__force u16)keys->ports.src))) {
			swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
			swap(keys->ports.src, keys->ports.dst);
		}
		break;
	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
		addr_diff = memcmp(&keys->addrs.v6addrs.dst,
				   &keys->addrs.v6addrs.src,
				   sizeof(keys->addrs.v6addrs.dst));
		if ((addr_diff < 0) ||
		    (addr_diff == 0 &&
		     ((__force u16)keys->ports.dst <
		      (__force u16)keys->ports.src))) {
			for (i = 0; i < 4; i++)
				swap(keys->addrs.v6addrs.src.s6_addr32[i],
				     keys->addrs.v6addrs.dst.s6_addr32[i]);
			swap(keys->ports.src, keys->ports.dst);
		}
		break;
	}
1153 1154
}

T
Tom Herbert 已提交
1155
static inline u32 __flow_hash_from_keys(struct flow_keys *keys, u32 keyval)
1156 1157 1158
{
	u32 hash;

1159
	__flow_hash_consistentify(keys);
1160

1161
	hash = __flow_hash_words(flow_keys_hash_start(keys),
1162
				 flow_keys_hash_length(keys), keyval);
1163 1164 1165 1166 1167 1168 1169 1170
	if (!hash)
		hash = 1;

	return hash;
}

u32 flow_hash_from_keys(struct flow_keys *keys)
{
T
Tom Herbert 已提交
1171 1172
	__flow_hash_secret_init();
	return __flow_hash_from_keys(keys, hashrnd);
1173 1174 1175
}
EXPORT_SYMBOL(flow_hash_from_keys);

T
Tom Herbert 已提交
1176 1177 1178
static inline u32 ___skb_get_hash(const struct sk_buff *skb,
				  struct flow_keys *keys, u32 keyval)
{
1179 1180
	skb_flow_dissect_flow_keys(skb, keys,
				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
T
Tom Herbert 已提交
1181 1182 1183 1184

	return __flow_hash_from_keys(keys, keyval);
}

T
Tom Herbert 已提交
1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203
struct _flow_keys_digest_data {
	__be16	n_proto;
	u8	ip_proto;
	u8	padding;
	__be32	ports;
	__be32	src;
	__be32	dst;
};

void make_flow_keys_digest(struct flow_keys_digest *digest,
			   const struct flow_keys *flow)
{
	struct _flow_keys_digest_data *data =
	    (struct _flow_keys_digest_data *)digest;

	BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));

	memset(digest, 0, sizeof(*digest));

1204 1205 1206
	data->n_proto = flow->basic.n_proto;
	data->ip_proto = flow->basic.ip_proto;
	data->ports = flow->ports.ports;
1207 1208
	data->src = flow->addrs.v4addrs.src;
	data->dst = flow->addrs.v4addrs.dst;
T
Tom Herbert 已提交
1209 1210 1211
}
EXPORT_SYMBOL(make_flow_keys_digest);

1212 1213
static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;

1214
u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228
{
	struct flow_keys keys;

	__flow_hash_secret_init();

	memset(&keys, 0, sizeof(keys));
	__skb_flow_dissect(skb, &flow_keys_dissector_symmetric, &keys,
			   NULL, 0, 0, 0,
			   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);

	return __flow_hash_from_keys(&keys, hashrnd);
}
EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);

1229 1230 1231 1232 1233
/**
 * __skb_get_hash: calculate a flow hash
 * @skb: sk_buff to calculate flow hash from
 *
 * This function calculates a flow hash based on src/dst addresses
1234 1235
 * and src/dst port numbers.  Sets hash in skb to non-zero hash value
 * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1236 1237
 * if hash is a canonical 4-tuple hash over transport ports.
 */
1238
void __skb_get_hash(struct sk_buff *skb)
1239 1240
{
	struct flow_keys keys;
1241
	u32 hash;
1242

T
Tom Herbert 已提交
1243 1244
	__flow_hash_secret_init();

1245 1246 1247
	hash = ___skb_get_hash(skb, &keys, hashrnd);

	__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1248
}
1249
EXPORT_SYMBOL(__skb_get_hash);
1250

T
Tom Herbert 已提交
1251 1252 1253 1254 1255 1256 1257 1258
__u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
{
	struct flow_keys keys;

	return ___skb_get_hash(skb, &keys, perturb);
}
EXPORT_SYMBOL(skb_get_hash_perturb);

1259
u32 __skb_get_poff(const struct sk_buff *skb, void *data,
1260
		   const struct flow_keys_basic *keys, int hlen)
1261
{
1262
	u32 poff = keys->control.thoff;
1263

1264 1265 1266 1267 1268
	/* skip L4 headers for fragments after the first */
	if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
	    !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
		return poff;

1269
	switch (keys->basic.ip_proto) {
1270
	case IPPROTO_TCP: {
1271 1272 1273
		/* access doff as u8 to avoid unaligned access */
		const u8 *doff;
		u8 _doff;
1274

1275 1276 1277
		doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
					    data, hlen, &_doff);
		if (!doff)
1278 1279
			return poff;

1280
		poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309
		break;
	}
	case IPPROTO_UDP:
	case IPPROTO_UDPLITE:
		poff += sizeof(struct udphdr);
		break;
	/* For the rest, we do not really care about header
	 * extensions at this point for now.
	 */
	case IPPROTO_ICMP:
		poff += sizeof(struct icmphdr);
		break;
	case IPPROTO_ICMPV6:
		poff += sizeof(struct icmp6hdr);
		break;
	case IPPROTO_IGMP:
		poff += sizeof(struct igmphdr);
		break;
	case IPPROTO_DCCP:
		poff += sizeof(struct dccp_hdr);
		break;
	case IPPROTO_SCTP:
		poff += sizeof(struct sctphdr);
		break;
	}

	return poff;
}

1310 1311 1312 1313 1314 1315
/**
 * skb_get_poff - get the offset to the payload
 * @skb: sk_buff to get the payload offset from
 *
 * The function will get the offset to the payload as far as it could
 * be dissected.  The main user is currently BPF, so that we can dynamically
1316 1317 1318 1319 1320
 * truncate packets without needing to push actual payload to the user
 * space and can analyze headers only, instead.
 */
u32 skb_get_poff(const struct sk_buff *skb)
{
1321
	struct flow_keys_basic keys;
1322

1323
	if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
1324 1325 1326 1327
		return 0;

	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
}
1328

1329
__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340
{
	memset(keys, 0, sizeof(*keys));

	memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
	    sizeof(keys->addrs.v6addrs.src));
	memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
	    sizeof(keys->addrs.v6addrs.dst));
	keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
	keys->ports.src = fl6->fl6_sport;
	keys->ports.dst = fl6->fl6_dport;
	keys->keyid.keyid = fl6->fl6_gre_key;
1341
	keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1342 1343 1344 1345 1346 1347
	keys->basic.ip_proto = fl6->flowi6_proto;

	return flow_hash_from_keys(keys);
}
EXPORT_SYMBOL(__get_hash_from_flowi6);

1348
static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1349 1350 1351 1352
	{
		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
		.offset = offsetof(struct flow_keys, control),
	},
1353 1354 1355 1356 1357 1358
	{
		.key_id = FLOW_DISSECTOR_KEY_BASIC,
		.offset = offsetof(struct flow_keys, basic),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1359 1360 1361 1362 1363
		.offset = offsetof(struct flow_keys, addrs.v4addrs),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
		.offset = offsetof(struct flow_keys, addrs.v6addrs),
1364
	},
T
Tom Herbert 已提交
1365
	{
1366 1367
		.key_id = FLOW_DISSECTOR_KEY_TIPC,
		.offset = offsetof(struct flow_keys, addrs.tipckey),
T
Tom Herbert 已提交
1368
	},
1369 1370 1371 1372
	{
		.key_id = FLOW_DISSECTOR_KEY_PORTS,
		.offset = offsetof(struct flow_keys, ports),
	},
T
Tom Herbert 已提交
1373
	{
1374 1375
		.key_id = FLOW_DISSECTOR_KEY_VLAN,
		.offset = offsetof(struct flow_keys, vlan),
T
Tom Herbert 已提交
1376
	},
1377 1378 1379 1380
	{
		.key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
		.offset = offsetof(struct flow_keys, tags),
	},
T
Tom Herbert 已提交
1381 1382 1383 1384
	{
		.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
		.offset = offsetof(struct flow_keys, keyid),
	},
1385 1386
};

1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409
static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
	{
		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
		.offset = offsetof(struct flow_keys, control),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_BASIC,
		.offset = offsetof(struct flow_keys, basic),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
		.offset = offsetof(struct flow_keys, addrs.v4addrs),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
		.offset = offsetof(struct flow_keys, addrs.v6addrs),
	},
	{
		.key_id = FLOW_DISSECTOR_KEY_PORTS,
		.offset = offsetof(struct flow_keys, ports),
	},
};

1410
static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1411 1412 1413 1414
	{
		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
		.offset = offsetof(struct flow_keys, control),
	},
1415 1416 1417 1418 1419 1420 1421 1422 1423
	{
		.key_id = FLOW_DISSECTOR_KEY_BASIC,
		.offset = offsetof(struct flow_keys, basic),
	},
};

struct flow_dissector flow_keys_dissector __read_mostly;
EXPORT_SYMBOL(flow_keys_dissector);

1424 1425
struct flow_dissector flow_keys_basic_dissector __read_mostly;
EXPORT_SYMBOL(flow_keys_basic_dissector);
1426 1427 1428 1429 1430 1431

static int __init init_default_flow_dissectors(void)
{
	skb_flow_dissector_init(&flow_keys_dissector,
				flow_keys_dissector_keys,
				ARRAY_SIZE(flow_keys_dissector_keys));
1432 1433 1434
	skb_flow_dissector_init(&flow_keys_dissector_symmetric,
				flow_keys_dissector_symmetric_keys,
				ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1435 1436 1437
	skb_flow_dissector_init(&flow_keys_basic_dissector,
				flow_keys_basic_dissector_keys,
				ARRAY_SIZE(flow_keys_basic_dissector_keys));
1438 1439 1440
	return 0;
}

1441
core_initcall(init_default_flow_dissectors);