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 <linux/filter.h>
   9#include <net/dsa.h>
  10#include <net/dst_metadata.h>
  11#include <net/ip.h>
  12#include <net/ipv6.h>
  13#include <net/gre.h>
  14#include <net/pptp.h>
  15#include <net/tipc.h>
  16#include <linux/igmp.h>
  17#include <linux/icmp.h>
  18#include <linux/sctp.h>
  19#include <linux/dccp.h>
  20#include <linux/if_tunnel.h>
  21#include <linux/if_pppox.h>
  22#include <linux/ppp_defs.h>
  23#include <linux/stddef.h>
  24#include <linux/if_ether.h>
  25#include <linux/if_hsr.h>
  26#include <linux/mpls.h>
  27#include <linux/tcp.h>
  28#include <linux/ptp_classify.h>
  29#include <net/flow_dissector.h>
 
  30#include <scsi/fc/fc_fcoe.h>
  31#include <uapi/linux/batadv_packet.h>
  32#include <linux/bpf.h>
  33#if IS_ENABLED(CONFIG_NF_CONNTRACK)
  34#include <net/netfilter/nf_conntrack_core.h>
  35#include <net/netfilter/nf_conntrack_labels.h>
  36#endif
  37#include <linux/bpf-netns.h>
  38
  39static void dissector_set_key(struct flow_dissector *flow_dissector,
  40			      enum flow_dissector_key_id key_id)
  41{
  42	flow_dissector->used_keys |= (1 << key_id);
  43}
  44
  45void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
  46			     const struct flow_dissector_key *key,
  47			     unsigned int key_count)
  48{
  49	unsigned int i;
  50
  51	memset(flow_dissector, 0, sizeof(*flow_dissector));
  52
  53	for (i = 0; i < key_count; i++, key++) {
  54		/* User should make sure that every key target offset is within
  55		 * boundaries of unsigned short.
  56		 */
  57		BUG_ON(key->offset > USHRT_MAX);
  58		BUG_ON(dissector_uses_key(flow_dissector,
  59					  key->key_id));
  60
  61		dissector_set_key(flow_dissector, key->key_id);
  62		flow_dissector->offset[key->key_id] = key->offset;
  63	}
  64
  65	/* Ensure that the dissector always includes control and basic key.
  66	 * That way we are able to avoid handling lack of these in fast path.
  67	 */
  68	BUG_ON(!dissector_uses_key(flow_dissector,
  69				   FLOW_DISSECTOR_KEY_CONTROL));
  70	BUG_ON(!dissector_uses_key(flow_dissector,
  71				   FLOW_DISSECTOR_KEY_BASIC));
  72}
  73EXPORT_SYMBOL(skb_flow_dissector_init);
  74
  75#ifdef CONFIG_BPF_SYSCALL
  76int flow_dissector_bpf_prog_attach_check(struct net *net,
  77					 struct bpf_prog *prog)
  78{
  79	enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
  80
  81	if (net == &init_net) {
  82		/* BPF flow dissector in the root namespace overrides
  83		 * any per-net-namespace one. When attaching to root,
  84		 * make sure we don't have any BPF program attached
  85		 * to the non-root namespaces.
  86		 */
  87		struct net *ns;
  88
  89		for_each_net(ns) {
  90			if (ns == &init_net)
  91				continue;
  92			if (rcu_access_pointer(ns->bpf.run_array[type]))
  93				return -EEXIST;
  94		}
  95	} else {
  96		/* Make sure root flow dissector is not attached
  97		 * when attaching to the non-root namespace.
  98		 */
  99		if (rcu_access_pointer(init_net.bpf.run_array[type]))
 100			return -EEXIST;
 101	}
 102
 103	return 0;
 104}
 105#endif /* CONFIG_BPF_SYSCALL */
 106
 107/**
 108 * __skb_flow_get_ports - extract the upper layer ports and return them
 109 * @skb: sk_buff to extract the ports from
 110 * @thoff: transport header offset
 111 * @ip_proto: protocol for which to get port offset
 112 * @data: raw buffer pointer to the packet, if NULL use skb->data
 113 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 114 *
 115 * The function will try to retrieve the ports at offset thoff + poff where poff
 116 * is the protocol port offset returned from proto_ports_offset
 117 */
 118__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
 119			    const void *data, int hlen)
 120{
 121	int poff = proto_ports_offset(ip_proto);
 122
 123	if (!data) {
 124		data = skb->data;
 125		hlen = skb_headlen(skb);
 126	}
 127
 128	if (poff >= 0) {
 129		__be32 *ports, _ports;
 130
 131		ports = __skb_header_pointer(skb, thoff + poff,
 132					     sizeof(_ports), data, hlen, &_ports);
 133		if (ports)
 134			return *ports;
 135	}
 136
 137	return 0;
 138}
 139EXPORT_SYMBOL(__skb_flow_get_ports);
 140
 141static bool icmp_has_id(u8 type)
 142{
 143	switch (type) {
 144	case ICMP_ECHO:
 145	case ICMP_ECHOREPLY:
 146	case ICMP_TIMESTAMP:
 147	case ICMP_TIMESTAMPREPLY:
 148	case ICMPV6_ECHO_REQUEST:
 149	case ICMPV6_ECHO_REPLY:
 150		return true;
 151	}
 152
 153	return false;
 154}
 155
 156/**
 157 * skb_flow_get_icmp_tci - extract ICMP(6) Type, Code and Identifier fields
 158 * @skb: sk_buff to extract from
 159 * @key_icmp: struct flow_dissector_key_icmp to fill
 160 * @data: raw buffer pointer to the packet
 161 * @thoff: offset to extract at
 162 * @hlen: packet header length
 163 */
 164void skb_flow_get_icmp_tci(const struct sk_buff *skb,
 165			   struct flow_dissector_key_icmp *key_icmp,
 166			   const void *data, int thoff, int hlen)
 167{
 168	struct icmphdr *ih, _ih;
 169
 170	ih = __skb_header_pointer(skb, thoff, sizeof(_ih), data, hlen, &_ih);
 171	if (!ih)
 172		return;
 173
 174	key_icmp->type = ih->type;
 175	key_icmp->code = ih->code;
 176
 177	/* As we use 0 to signal that the Id field is not present,
 178	 * avoid confusion with packets without such field
 179	 */
 180	if (icmp_has_id(ih->type))
 181		key_icmp->id = ih->un.echo.id ? ntohs(ih->un.echo.id) : 1;
 182	else
 183		key_icmp->id = 0;
 184}
 185EXPORT_SYMBOL(skb_flow_get_icmp_tci);
 186
 187/* If FLOW_DISSECTOR_KEY_ICMP is set, dissect an ICMP packet
 188 * using skb_flow_get_icmp_tci().
 189 */
 190static void __skb_flow_dissect_icmp(const struct sk_buff *skb,
 191				    struct flow_dissector *flow_dissector,
 192				    void *target_container, const void *data,
 193				    int thoff, int hlen)
 194{
 195	struct flow_dissector_key_icmp *key_icmp;
 196
 197	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ICMP))
 198		return;
 199
 200	key_icmp = skb_flow_dissector_target(flow_dissector,
 201					     FLOW_DISSECTOR_KEY_ICMP,
 202					     target_container);
 203
 204	skb_flow_get_icmp_tci(skb, key_icmp, data, thoff, hlen);
 205}
 206
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 207static void __skb_flow_dissect_l2tpv3(const struct sk_buff *skb,
 208				      struct flow_dissector *flow_dissector,
 209				      void *target_container, const void *data,
 210				      int nhoff, int hlen)
 211{
 212	struct flow_dissector_key_l2tpv3 *key_l2tpv3;
 213	struct {
 214		__be32 session_id;
 215	} *hdr, _hdr;
 216
 217	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_L2TPV3))
 218		return;
 219
 220	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 221	if (!hdr)
 222		return;
 223
 224	key_l2tpv3 = skb_flow_dissector_target(flow_dissector,
 225					       FLOW_DISSECTOR_KEY_L2TPV3,
 226					       target_container);
 227
 228	key_l2tpv3->session_id = hdr->session_id;
 229}
 230
 231void skb_flow_dissect_meta(const struct sk_buff *skb,
 232			   struct flow_dissector *flow_dissector,
 233			   void *target_container)
 234{
 235	struct flow_dissector_key_meta *meta;
 236
 237	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_META))
 238		return;
 239
 240	meta = skb_flow_dissector_target(flow_dissector,
 241					 FLOW_DISSECTOR_KEY_META,
 242					 target_container);
 243	meta->ingress_ifindex = skb->skb_iif;
 
 
 
 
 
 
 
 
 
 244}
 245EXPORT_SYMBOL(skb_flow_dissect_meta);
 246
 247static void
 248skb_flow_dissect_set_enc_addr_type(enum flow_dissector_key_id type,
 249				   struct flow_dissector *flow_dissector,
 250				   void *target_container)
 251{
 252	struct flow_dissector_key_control *ctrl;
 253
 254	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_CONTROL))
 255		return;
 256
 257	ctrl = skb_flow_dissector_target(flow_dissector,
 258					 FLOW_DISSECTOR_KEY_ENC_CONTROL,
 259					 target_container);
 260	ctrl->addr_type = type;
 261}
 262
 263void
 264skb_flow_dissect_ct(const struct sk_buff *skb,
 265		    struct flow_dissector *flow_dissector,
 266		    void *target_container, u16 *ctinfo_map,
 267		    size_t mapsize, bool post_ct, u16 zone)
 268{
 269#if IS_ENABLED(CONFIG_NF_CONNTRACK)
 270	struct flow_dissector_key_ct *key;
 271	enum ip_conntrack_info ctinfo;
 272	struct nf_conn_labels *cl;
 273	struct nf_conn *ct;
 274
 275	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_CT))
 276		return;
 277
 278	ct = nf_ct_get(skb, &ctinfo);
 279	if (!ct && !post_ct)
 280		return;
 281
 282	key = skb_flow_dissector_target(flow_dissector,
 283					FLOW_DISSECTOR_KEY_CT,
 284					target_container);
 285
 286	if (!ct) {
 287		key->ct_state = TCA_FLOWER_KEY_CT_FLAGS_TRACKED |
 288				TCA_FLOWER_KEY_CT_FLAGS_INVALID;
 289		key->ct_zone = zone;
 290		return;
 291	}
 292
 293	if (ctinfo < mapsize)
 294		key->ct_state = ctinfo_map[ctinfo];
 295#if IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)
 296	key->ct_zone = ct->zone.id;
 297#endif
 298#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
 299	key->ct_mark = READ_ONCE(ct->mark);
 300#endif
 301
 302	cl = nf_ct_labels_find(ct);
 303	if (cl)
 304		memcpy(key->ct_labels, cl->bits, sizeof(key->ct_labels));
 305#endif /* CONFIG_NF_CONNTRACK */
 306}
 307EXPORT_SYMBOL(skb_flow_dissect_ct);
 308
 309void
 310skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
 311			     struct flow_dissector *flow_dissector,
 312			     void *target_container)
 313{
 314	struct ip_tunnel_info *info;
 315	struct ip_tunnel_key *key;
 316
 317	/* A quick check to see if there might be something to do. */
 318	if (!dissector_uses_key(flow_dissector,
 319				FLOW_DISSECTOR_KEY_ENC_KEYID) &&
 320	    !dissector_uses_key(flow_dissector,
 321				FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS) &&
 322	    !dissector_uses_key(flow_dissector,
 323				FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS) &&
 324	    !dissector_uses_key(flow_dissector,
 325				FLOW_DISSECTOR_KEY_ENC_CONTROL) &&
 326	    !dissector_uses_key(flow_dissector,
 327				FLOW_DISSECTOR_KEY_ENC_PORTS) &&
 328	    !dissector_uses_key(flow_dissector,
 329				FLOW_DISSECTOR_KEY_ENC_IP) &&
 330	    !dissector_uses_key(flow_dissector,
 331				FLOW_DISSECTOR_KEY_ENC_OPTS))
 332		return;
 333
 334	info = skb_tunnel_info(skb);
 335	if (!info)
 336		return;
 337
 338	key = &info->key;
 339
 340	switch (ip_tunnel_info_af(info)) {
 341	case AF_INET:
 342		skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 343						   flow_dissector,
 344						   target_container);
 345		if (dissector_uses_key(flow_dissector,
 346				       FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS)) {
 347			struct flow_dissector_key_ipv4_addrs *ipv4;
 348
 349			ipv4 = skb_flow_dissector_target(flow_dissector,
 350							 FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS,
 351							 target_container);
 352			ipv4->src = key->u.ipv4.src;
 353			ipv4->dst = key->u.ipv4.dst;
 354		}
 355		break;
 356	case AF_INET6:
 357		skb_flow_dissect_set_enc_addr_type(FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 358						   flow_dissector,
 359						   target_container);
 360		if (dissector_uses_key(flow_dissector,
 361				       FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS)) {
 362			struct flow_dissector_key_ipv6_addrs *ipv6;
 363
 364			ipv6 = skb_flow_dissector_target(flow_dissector,
 365							 FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS,
 366							 target_container);
 367			ipv6->src = key->u.ipv6.src;
 368			ipv6->dst = key->u.ipv6.dst;
 369		}
 370		break;
 371	}
 372
 373	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_KEYID)) {
 374		struct flow_dissector_key_keyid *keyid;
 375
 376		keyid = skb_flow_dissector_target(flow_dissector,
 377						  FLOW_DISSECTOR_KEY_ENC_KEYID,
 378						  target_container);
 379		keyid->keyid = tunnel_id_to_key32(key->tun_id);
 380	}
 381
 382	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_PORTS)) {
 383		struct flow_dissector_key_ports *tp;
 384
 385		tp = skb_flow_dissector_target(flow_dissector,
 386					       FLOW_DISSECTOR_KEY_ENC_PORTS,
 387					       target_container);
 388		tp->src = key->tp_src;
 389		tp->dst = key->tp_dst;
 390	}
 391
 392	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
 393		struct flow_dissector_key_ip *ip;
 394
 395		ip = skb_flow_dissector_target(flow_dissector,
 396					       FLOW_DISSECTOR_KEY_ENC_IP,
 397					       target_container);
 398		ip->tos = key->tos;
 399		ip->ttl = key->ttl;
 400	}
 401
 402	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
 403		struct flow_dissector_key_enc_opts *enc_opt;
 404
 405		enc_opt = skb_flow_dissector_target(flow_dissector,
 406						    FLOW_DISSECTOR_KEY_ENC_OPTS,
 407						    target_container);
 408
 409		if (info->options_len) {
 410			enc_opt->len = info->options_len;
 411			ip_tunnel_info_opts_get(enc_opt->data, info);
 412			enc_opt->dst_opt_type = info->key.tun_flags &
 413						TUNNEL_OPTIONS_PRESENT;
 414		}
 415	}
 416}
 417EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
 418
 419void skb_flow_dissect_hash(const struct sk_buff *skb,
 420			   struct flow_dissector *flow_dissector,
 421			   void *target_container)
 422{
 423	struct flow_dissector_key_hash *key;
 424
 425	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_HASH))
 426		return;
 427
 428	key = skb_flow_dissector_target(flow_dissector,
 429					FLOW_DISSECTOR_KEY_HASH,
 430					target_container);
 431
 432	key->hash = skb_get_hash_raw(skb);
 433}
 434EXPORT_SYMBOL(skb_flow_dissect_hash);
 435
 436static enum flow_dissect_ret
 437__skb_flow_dissect_mpls(const struct sk_buff *skb,
 438			struct flow_dissector *flow_dissector,
 439			void *target_container, const void *data, int nhoff,
 440			int hlen, int lse_index, bool *entropy_label)
 441{
 442	struct mpls_label *hdr, _hdr;
 443	u32 entry, label, bos;
 444
 445	if (!dissector_uses_key(flow_dissector,
 446				FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
 447	    !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
 448		return FLOW_DISSECT_RET_OUT_GOOD;
 449
 450	if (lse_index >= FLOW_DIS_MPLS_MAX)
 451		return FLOW_DISSECT_RET_OUT_GOOD;
 452
 453	hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
 454				   hlen, &_hdr);
 455	if (!hdr)
 456		return FLOW_DISSECT_RET_OUT_BAD;
 457
 458	entry = ntohl(hdr->entry);
 459	label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
 460	bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
 461
 462	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS)) {
 463		struct flow_dissector_key_mpls *key_mpls;
 464		struct flow_dissector_mpls_lse *lse;
 465
 466		key_mpls = skb_flow_dissector_target(flow_dissector,
 467						     FLOW_DISSECTOR_KEY_MPLS,
 468						     target_container);
 469		lse = &key_mpls->ls[lse_index];
 470
 471		lse->mpls_ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
 472		lse->mpls_bos = bos;
 473		lse->mpls_tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
 474		lse->mpls_label = label;
 475		dissector_set_mpls_lse(key_mpls, lse_index);
 476	}
 477
 478	if (*entropy_label &&
 479	    dissector_uses_key(flow_dissector,
 480			       FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 481		struct flow_dissector_key_keyid *key_keyid;
 482
 483		key_keyid = skb_flow_dissector_target(flow_dissector,
 484						      FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
 485						      target_container);
 486		key_keyid->keyid = cpu_to_be32(label);
 487	}
 488
 489	*entropy_label = label == MPLS_LABEL_ENTROPY;
 490
 491	return bos ? FLOW_DISSECT_RET_OUT_GOOD : FLOW_DISSECT_RET_PROTO_AGAIN;
 492}
 493
 494static enum flow_dissect_ret
 495__skb_flow_dissect_arp(const struct sk_buff *skb,
 496		       struct flow_dissector *flow_dissector,
 497		       void *target_container, const void *data,
 498		       int nhoff, int hlen)
 499{
 500	struct flow_dissector_key_arp *key_arp;
 501	struct {
 502		unsigned char ar_sha[ETH_ALEN];
 503		unsigned char ar_sip[4];
 504		unsigned char ar_tha[ETH_ALEN];
 505		unsigned char ar_tip[4];
 506	} *arp_eth, _arp_eth;
 507	const struct arphdr *arp;
 508	struct arphdr _arp;
 509
 510	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ARP))
 511		return FLOW_DISSECT_RET_OUT_GOOD;
 512
 513	arp = __skb_header_pointer(skb, nhoff, sizeof(_arp), data,
 514				   hlen, &_arp);
 515	if (!arp)
 516		return FLOW_DISSECT_RET_OUT_BAD;
 517
 518	if (arp->ar_hrd != htons(ARPHRD_ETHER) ||
 519	    arp->ar_pro != htons(ETH_P_IP) ||
 520	    arp->ar_hln != ETH_ALEN ||
 521	    arp->ar_pln != 4 ||
 522	    (arp->ar_op != htons(ARPOP_REPLY) &&
 523	     arp->ar_op != htons(ARPOP_REQUEST)))
 524		return FLOW_DISSECT_RET_OUT_BAD;
 525
 526	arp_eth = __skb_header_pointer(skb, nhoff + sizeof(_arp),
 527				       sizeof(_arp_eth), data,
 528				       hlen, &_arp_eth);
 529	if (!arp_eth)
 530		return FLOW_DISSECT_RET_OUT_BAD;
 531
 532	key_arp = skb_flow_dissector_target(flow_dissector,
 533					    FLOW_DISSECTOR_KEY_ARP,
 534					    target_container);
 535
 536	memcpy(&key_arp->sip, arp_eth->ar_sip, sizeof(key_arp->sip));
 537	memcpy(&key_arp->tip, arp_eth->ar_tip, sizeof(key_arp->tip));
 538
 539	/* Only store the lower byte of the opcode;
 540	 * this covers ARPOP_REPLY and ARPOP_REQUEST.
 541	 */
 542	key_arp->op = ntohs(arp->ar_op) & 0xff;
 543
 544	ether_addr_copy(key_arp->sha, arp_eth->ar_sha);
 545	ether_addr_copy(key_arp->tha, arp_eth->ar_tha);
 546
 547	return FLOW_DISSECT_RET_OUT_GOOD;
 548}
 549
 550static enum flow_dissect_ret
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 551__skb_flow_dissect_gre(const struct sk_buff *skb,
 552		       struct flow_dissector_key_control *key_control,
 553		       struct flow_dissector *flow_dissector,
 554		       void *target_container, const void *data,
 555		       __be16 *p_proto, int *p_nhoff, int *p_hlen,
 556		       unsigned int flags)
 557{
 558	struct flow_dissector_key_keyid *key_keyid;
 559	struct gre_base_hdr *hdr, _hdr;
 560	int offset = 0;
 561	u16 gre_ver;
 562
 563	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr),
 564				   data, *p_hlen, &_hdr);
 565	if (!hdr)
 566		return FLOW_DISSECT_RET_OUT_BAD;
 567
 568	/* Only look inside GRE without routing */
 569	if (hdr->flags & GRE_ROUTING)
 570		return FLOW_DISSECT_RET_OUT_GOOD;
 571
 572	/* Only look inside GRE for version 0 and 1 */
 573	gre_ver = ntohs(hdr->flags & GRE_VERSION);
 574	if (gre_ver > 1)
 575		return FLOW_DISSECT_RET_OUT_GOOD;
 576
 577	*p_proto = hdr->protocol;
 578	if (gre_ver) {
 579		/* Version1 must be PPTP, and check the flags */
 580		if (!(*p_proto == GRE_PROTO_PPP && (hdr->flags & GRE_KEY)))
 581			return FLOW_DISSECT_RET_OUT_GOOD;
 582	}
 583
 584	offset += sizeof(struct gre_base_hdr);
 585
 586	if (hdr->flags & GRE_CSUM)
 587		offset += sizeof_field(struct gre_full_hdr, csum) +
 588			  sizeof_field(struct gre_full_hdr, reserved1);
 589
 590	if (hdr->flags & GRE_KEY) {
 591		const __be32 *keyid;
 592		__be32 _keyid;
 593
 594		keyid = __skb_header_pointer(skb, *p_nhoff + offset,
 595					     sizeof(_keyid),
 596					     data, *p_hlen, &_keyid);
 597		if (!keyid)
 598			return FLOW_DISSECT_RET_OUT_BAD;
 599
 600		if (dissector_uses_key(flow_dissector,
 601				       FLOW_DISSECTOR_KEY_GRE_KEYID)) {
 602			key_keyid = skb_flow_dissector_target(flow_dissector,
 603							      FLOW_DISSECTOR_KEY_GRE_KEYID,
 604							      target_container);
 605			if (gre_ver == 0)
 606				key_keyid->keyid = *keyid;
 607			else
 608				key_keyid->keyid = *keyid & GRE_PPTP_KEY_MASK;
 609		}
 610		offset += sizeof_field(struct gre_full_hdr, key);
 611	}
 612
 613	if (hdr->flags & GRE_SEQ)
 614		offset += sizeof_field(struct pptp_gre_header, seq);
 615
 616	if (gre_ver == 0) {
 617		if (*p_proto == htons(ETH_P_TEB)) {
 618			const struct ethhdr *eth;
 619			struct ethhdr _eth;
 620
 621			eth = __skb_header_pointer(skb, *p_nhoff + offset,
 622						   sizeof(_eth),
 623						   data, *p_hlen, &_eth);
 624			if (!eth)
 625				return FLOW_DISSECT_RET_OUT_BAD;
 626			*p_proto = eth->h_proto;
 627			offset += sizeof(*eth);
 628
 629			/* Cap headers that we access via pointers at the
 630			 * end of the Ethernet header as our maximum alignment
 631			 * at that point is only 2 bytes.
 632			 */
 633			if (NET_IP_ALIGN)
 634				*p_hlen = *p_nhoff + offset;
 635		}
 636	} else { /* version 1, must be PPTP */
 637		u8 _ppp_hdr[PPP_HDRLEN];
 638		u8 *ppp_hdr;
 639
 640		if (hdr->flags & GRE_ACK)
 641			offset += sizeof_field(struct pptp_gre_header, ack);
 642
 643		ppp_hdr = __skb_header_pointer(skb, *p_nhoff + offset,
 644					       sizeof(_ppp_hdr),
 645					       data, *p_hlen, _ppp_hdr);
 646		if (!ppp_hdr)
 647			return FLOW_DISSECT_RET_OUT_BAD;
 648
 649		switch (PPP_PROTOCOL(ppp_hdr)) {
 650		case PPP_IP:
 651			*p_proto = htons(ETH_P_IP);
 652			break;
 653		case PPP_IPV6:
 654			*p_proto = htons(ETH_P_IPV6);
 655			break;
 656		default:
 657			/* Could probably catch some more like MPLS */
 658			break;
 659		}
 660
 661		offset += PPP_HDRLEN;
 662	}
 663
 664	*p_nhoff += offset;
 665	key_control->flags |= FLOW_DIS_ENCAPSULATION;
 666	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 667		return FLOW_DISSECT_RET_OUT_GOOD;
 668
 669	return FLOW_DISSECT_RET_PROTO_AGAIN;
 670}
 671
 672/**
 673 * __skb_flow_dissect_batadv() - dissect batman-adv header
 674 * @skb: sk_buff to with the batman-adv header
 675 * @key_control: flow dissectors control key
 676 * @data: raw buffer pointer to the packet, if NULL use skb->data
 677 * @p_proto: pointer used to update the protocol to process next
 678 * @p_nhoff: pointer used to update inner network header offset
 679 * @hlen: packet header length
 680 * @flags: any combination of FLOW_DISSECTOR_F_*
 681 *
 682 * ETH_P_BATMAN packets are tried to be dissected. Only
 683 * &struct batadv_unicast packets are actually processed because they contain an
 684 * inner ethernet header and are usually followed by actual network header. This
 685 * allows the flow dissector to continue processing the packet.
 686 *
 687 * Return: FLOW_DISSECT_RET_PROTO_AGAIN when &struct batadv_unicast was found,
 688 *  FLOW_DISSECT_RET_OUT_GOOD when dissector should stop after encapsulation,
 689 *  otherwise FLOW_DISSECT_RET_OUT_BAD
 690 */
 691static enum flow_dissect_ret
 692__skb_flow_dissect_batadv(const struct sk_buff *skb,
 693			  struct flow_dissector_key_control *key_control,
 694			  const void *data, __be16 *p_proto, int *p_nhoff,
 695			  int hlen, unsigned int flags)
 696{
 697	struct {
 698		struct batadv_unicast_packet batadv_unicast;
 699		struct ethhdr eth;
 700	} *hdr, _hdr;
 701
 702	hdr = __skb_header_pointer(skb, *p_nhoff, sizeof(_hdr), data, hlen,
 703				   &_hdr);
 704	if (!hdr)
 705		return FLOW_DISSECT_RET_OUT_BAD;
 706
 707	if (hdr->batadv_unicast.version != BATADV_COMPAT_VERSION)
 708		return FLOW_DISSECT_RET_OUT_BAD;
 709
 710	if (hdr->batadv_unicast.packet_type != BATADV_UNICAST)
 711		return FLOW_DISSECT_RET_OUT_BAD;
 712
 713	*p_proto = hdr->eth.h_proto;
 714	*p_nhoff += sizeof(*hdr);
 715
 716	key_control->flags |= FLOW_DIS_ENCAPSULATION;
 717	if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP)
 718		return FLOW_DISSECT_RET_OUT_GOOD;
 719
 720	return FLOW_DISSECT_RET_PROTO_AGAIN;
 721}
 722
 723static void
 724__skb_flow_dissect_tcp(const struct sk_buff *skb,
 725		       struct flow_dissector *flow_dissector,
 726		       void *target_container, const void *data,
 727		       int thoff, int hlen)
 728{
 729	struct flow_dissector_key_tcp *key_tcp;
 730	struct tcphdr *th, _th;
 731
 732	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_TCP))
 733		return;
 734
 735	th = __skb_header_pointer(skb, thoff, sizeof(_th), data, hlen, &_th);
 736	if (!th)
 737		return;
 738
 739	if (unlikely(__tcp_hdrlen(th) < sizeof(_th)))
 740		return;
 741
 742	key_tcp = skb_flow_dissector_target(flow_dissector,
 743					    FLOW_DISSECTOR_KEY_TCP,
 744					    target_container);
 745	key_tcp->flags = (*(__be16 *) &tcp_flag_word(th) & htons(0x0FFF));
 746}
 747
 748static void
 749__skb_flow_dissect_ports(const struct sk_buff *skb,
 750			 struct flow_dissector *flow_dissector,
 751			 void *target_container, const void *data,
 752			 int nhoff, u8 ip_proto, int hlen)
 753{
 754	enum flow_dissector_key_id dissector_ports = FLOW_DISSECTOR_KEY_MAX;
 755	struct flow_dissector_key_ports *key_ports;
 756
 757	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 758		dissector_ports = FLOW_DISSECTOR_KEY_PORTS;
 759	else if (dissector_uses_key(flow_dissector,
 760				    FLOW_DISSECTOR_KEY_PORTS_RANGE))
 761		dissector_ports = FLOW_DISSECTOR_KEY_PORTS_RANGE;
 762
 763	if (dissector_ports == FLOW_DISSECTOR_KEY_MAX)
 764		return;
 765
 766	key_ports = skb_flow_dissector_target(flow_dissector,
 767					      dissector_ports,
 768					      target_container);
 769	key_ports->ports = __skb_flow_get_ports(skb, nhoff, ip_proto,
 770						data, hlen);
 771}
 772
 773static void
 774__skb_flow_dissect_ipv4(const struct sk_buff *skb,
 775			struct flow_dissector *flow_dissector,
 776			void *target_container, const void *data,
 777			const struct iphdr *iph)
 778{
 779	struct flow_dissector_key_ip *key_ip;
 780
 781	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 782		return;
 783
 784	key_ip = skb_flow_dissector_target(flow_dissector,
 785					   FLOW_DISSECTOR_KEY_IP,
 786					   target_container);
 787	key_ip->tos = iph->tos;
 788	key_ip->ttl = iph->ttl;
 789}
 790
 791static void
 792__skb_flow_dissect_ipv6(const struct sk_buff *skb,
 793			struct flow_dissector *flow_dissector,
 794			void *target_container, const void *data,
 795			const struct ipv6hdr *iph)
 796{
 797	struct flow_dissector_key_ip *key_ip;
 798
 799	if (!dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IP))
 800		return;
 801
 802	key_ip = skb_flow_dissector_target(flow_dissector,
 803					   FLOW_DISSECTOR_KEY_IP,
 804					   target_container);
 805	key_ip->tos = ipv6_get_dsfield(iph);
 806	key_ip->ttl = iph->hop_limit;
 807}
 808
 809/* Maximum number of protocol headers that can be parsed in
 810 * __skb_flow_dissect
 811 */
 812#define MAX_FLOW_DISSECT_HDRS	15
 813
 814static bool skb_flow_dissect_allowed(int *num_hdrs)
 815{
 816	++*num_hdrs;
 817
 818	return (*num_hdrs <= MAX_FLOW_DISSECT_HDRS);
 819}
 820
 821static void __skb_flow_bpf_to_target(const struct bpf_flow_keys *flow_keys,
 822				     struct flow_dissector *flow_dissector,
 823				     void *target_container)
 824{
 825	struct flow_dissector_key_ports *key_ports = NULL;
 826	struct flow_dissector_key_control *key_control;
 827	struct flow_dissector_key_basic *key_basic;
 828	struct flow_dissector_key_addrs *key_addrs;
 829	struct flow_dissector_key_tags *key_tags;
 830
 831	key_control = skb_flow_dissector_target(flow_dissector,
 832						FLOW_DISSECTOR_KEY_CONTROL,
 833						target_container);
 834	key_control->thoff = flow_keys->thoff;
 835	if (flow_keys->is_frag)
 836		key_control->flags |= FLOW_DIS_IS_FRAGMENT;
 837	if (flow_keys->is_first_frag)
 838		key_control->flags |= FLOW_DIS_FIRST_FRAG;
 839	if (flow_keys->is_encap)
 840		key_control->flags |= FLOW_DIS_ENCAPSULATION;
 841
 842	key_basic = skb_flow_dissector_target(flow_dissector,
 843					      FLOW_DISSECTOR_KEY_BASIC,
 844					      target_container);
 845	key_basic->n_proto = flow_keys->n_proto;
 846	key_basic->ip_proto = flow_keys->ip_proto;
 847
 848	if (flow_keys->addr_proto == ETH_P_IP &&
 849	    dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
 850		key_addrs = skb_flow_dissector_target(flow_dissector,
 851						      FLOW_DISSECTOR_KEY_IPV4_ADDRS,
 852						      target_container);
 853		key_addrs->v4addrs.src = flow_keys->ipv4_src;
 854		key_addrs->v4addrs.dst = flow_keys->ipv4_dst;
 855		key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
 856	} else if (flow_keys->addr_proto == ETH_P_IPV6 &&
 857		   dissector_uses_key(flow_dissector,
 858				      FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
 859		key_addrs = skb_flow_dissector_target(flow_dissector,
 860						      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
 861						      target_container);
 862		memcpy(&key_addrs->v6addrs.src, &flow_keys->ipv6_src,
 863		       sizeof(key_addrs->v6addrs.src));
 864		memcpy(&key_addrs->v6addrs.dst, &flow_keys->ipv6_dst,
 865		       sizeof(key_addrs->v6addrs.dst));
 866		key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 867	}
 868
 869	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS))
 870		key_ports = skb_flow_dissector_target(flow_dissector,
 871						      FLOW_DISSECTOR_KEY_PORTS,
 872						      target_container);
 873	else if (dissector_uses_key(flow_dissector,
 874				    FLOW_DISSECTOR_KEY_PORTS_RANGE))
 875		key_ports = skb_flow_dissector_target(flow_dissector,
 876						      FLOW_DISSECTOR_KEY_PORTS_RANGE,
 877						      target_container);
 878
 879	if (key_ports) {
 880		key_ports->src = flow_keys->sport;
 881		key_ports->dst = flow_keys->dport;
 882	}
 883
 884	if (dissector_uses_key(flow_dissector,
 885			       FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
 886		key_tags = skb_flow_dissector_target(flow_dissector,
 887						     FLOW_DISSECTOR_KEY_FLOW_LABEL,
 888						     target_container);
 889		key_tags->flow_label = ntohl(flow_keys->flow_label);
 890	}
 891}
 892
 893u32 bpf_flow_dissect(struct bpf_prog *prog, struct bpf_flow_dissector *ctx,
 894		     __be16 proto, int nhoff, int hlen, unsigned int flags)
 895{
 896	struct bpf_flow_keys *flow_keys = ctx->flow_keys;
 897	u32 result;
 898
 899	/* Pass parameters to the BPF program */
 900	memset(flow_keys, 0, sizeof(*flow_keys));
 901	flow_keys->n_proto = proto;
 902	flow_keys->nhoff = nhoff;
 903	flow_keys->thoff = flow_keys->nhoff;
 904
 905	BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_PARSE_1ST_FRAG !=
 906		     (int)FLOW_DISSECTOR_F_PARSE_1ST_FRAG);
 907	BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL !=
 908		     (int)FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
 909	BUILD_BUG_ON((int)BPF_FLOW_DISSECTOR_F_STOP_AT_ENCAP !=
 910		     (int)FLOW_DISSECTOR_F_STOP_AT_ENCAP);
 911	flow_keys->flags = flags;
 912
 913	result = bpf_prog_run_pin_on_cpu(prog, ctx);
 914
 915	flow_keys->nhoff = clamp_t(u16, flow_keys->nhoff, nhoff, hlen);
 916	flow_keys->thoff = clamp_t(u16, flow_keys->thoff,
 917				   flow_keys->nhoff, hlen);
 918
 919	return result;
 920}
 921
 922static bool is_pppoe_ses_hdr_valid(const struct pppoe_hdr *hdr)
 923{
 924	return hdr->ver == 1 && hdr->type == 1 && hdr->code == 0;
 925}
 926
 927/**
 928 * __skb_flow_dissect - extract the flow_keys struct and return it
 929 * @net: associated network namespace, derived from @skb if NULL
 930 * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
 931 * @flow_dissector: list of keys to dissect
 932 * @target_container: target structure to put dissected values into
 933 * @data: raw buffer pointer to the packet, if NULL use skb->data
 934 * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
 935 * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
 936 * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
 937 * @flags: flags that control the dissection process, e.g.
 938 *         FLOW_DISSECTOR_F_STOP_AT_ENCAP.
 939 *
 940 * The function will try to retrieve individual keys into target specified
 941 * by flow_dissector from either the skbuff or a raw buffer specified by the
 942 * rest parameters.
 943 *
 944 * Caller must take care of zeroing target container memory.
 945 */
 946bool __skb_flow_dissect(const struct net *net,
 947			const struct sk_buff *skb,
 948			struct flow_dissector *flow_dissector,
 949			void *target_container, const void *data,
 950			__be16 proto, int nhoff, int hlen, unsigned int flags)
 951{
 952	struct flow_dissector_key_control *key_control;
 953	struct flow_dissector_key_basic *key_basic;
 954	struct flow_dissector_key_addrs *key_addrs;
 955	struct flow_dissector_key_tags *key_tags;
 956	struct flow_dissector_key_vlan *key_vlan;
 957	enum flow_dissect_ret fdret;
 958	enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
 959	bool mpls_el = false;
 960	int mpls_lse = 0;
 961	int num_hdrs = 0;
 962	u8 ip_proto = 0;
 963	bool ret;
 964
 965	if (!data) {
 966		data = skb->data;
 967		proto = skb_vlan_tag_present(skb) ?
 968			 skb->vlan_proto : skb->protocol;
 969		nhoff = skb_network_offset(skb);
 970		hlen = skb_headlen(skb);
 971#if IS_ENABLED(CONFIG_NET_DSA)
 972		if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
 973			     proto == htons(ETH_P_XDSA))) {
 974			struct metadata_dst *md_dst = skb_metadata_dst(skb);
 975			const struct dsa_device_ops *ops;
 976			int offset = 0;
 977
 978			ops = skb->dev->dsa_ptr->tag_ops;
 979			/* Only DSA header taggers break flow dissection */
 980			if (ops->needed_headroom &&
 981			    (!md_dst || md_dst->type != METADATA_HW_PORT_MUX)) {
 982				if (ops->flow_dissect)
 983					ops->flow_dissect(skb, &proto, &offset);
 984				else
 985					dsa_tag_generic_flow_dissect(skb,
 986								     &proto,
 987								     &offset);
 988				hlen -= offset;
 989				nhoff += offset;
 990			}
 991		}
 992#endif
 993	}
 994
 995	/* It is ensured by skb_flow_dissector_init() that control key will
 996	 * be always present.
 997	 */
 998	key_control = skb_flow_dissector_target(flow_dissector,
 999						FLOW_DISSECTOR_KEY_CONTROL,
1000						target_container);
1001
1002	/* It is ensured by skb_flow_dissector_init() that basic key will
1003	 * be always present.
1004	 */
1005	key_basic = skb_flow_dissector_target(flow_dissector,
1006					      FLOW_DISSECTOR_KEY_BASIC,
1007					      target_container);
1008
1009	if (skb) {
1010		if (!net) {
1011			if (skb->dev)
1012				net = dev_net(skb->dev);
1013			else if (skb->sk)
1014				net = sock_net(skb->sk);
1015		}
1016	}
1017
1018	WARN_ON_ONCE(!net);
1019	if (net) {
1020		enum netns_bpf_attach_type type = NETNS_BPF_FLOW_DISSECTOR;
1021		struct bpf_prog_array *run_array;
1022
1023		rcu_read_lock();
1024		run_array = rcu_dereference(init_net.bpf.run_array[type]);
1025		if (!run_array)
1026			run_array = rcu_dereference(net->bpf.run_array[type]);
1027
1028		if (run_array) {
1029			struct bpf_flow_keys flow_keys;
1030			struct bpf_flow_dissector ctx = {
1031				.flow_keys = &flow_keys,
1032				.data = data,
1033				.data_end = data + hlen,
1034			};
1035			__be16 n_proto = proto;
1036			struct bpf_prog *prog;
1037			u32 result;
1038
1039			if (skb) {
1040				ctx.skb = skb;
1041				/* we can't use 'proto' in the skb case
1042				 * because it might be set to skb->vlan_proto
1043				 * which has been pulled from the data
1044				 */
1045				n_proto = skb->protocol;
1046			}
1047
1048			prog = READ_ONCE(run_array->items[0].prog);
1049			result = bpf_flow_dissect(prog, &ctx, n_proto, nhoff,
1050						  hlen, flags);
1051			if (result == BPF_FLOW_DISSECTOR_CONTINUE)
1052				goto dissect_continue;
1053			__skb_flow_bpf_to_target(&flow_keys, flow_dissector,
1054						 target_container);
1055			rcu_read_unlock();
1056			return result == BPF_OK;
1057		}
1058dissect_continue:
1059		rcu_read_unlock();
1060	}
1061
1062	if (dissector_uses_key(flow_dissector,
1063			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
1064		struct ethhdr *eth = eth_hdr(skb);
1065		struct flow_dissector_key_eth_addrs *key_eth_addrs;
1066
1067		key_eth_addrs = skb_flow_dissector_target(flow_dissector,
1068							  FLOW_DISSECTOR_KEY_ETH_ADDRS,
1069							  target_container);
1070		memcpy(key_eth_addrs, eth, sizeof(*key_eth_addrs));
1071	}
1072
1073	if (dissector_uses_key(flow_dissector,
1074			       FLOW_DISSECTOR_KEY_NUM_OF_VLANS)) {
1075		struct flow_dissector_key_num_of_vlans *key_num_of_vlans;
1076
1077		key_num_of_vlans = skb_flow_dissector_target(flow_dissector,
1078							     FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1079							     target_container);
1080		key_num_of_vlans->num_of_vlans = 0;
1081	}
1082
1083proto_again:
1084	fdret = FLOW_DISSECT_RET_CONTINUE;
1085
1086	switch (proto) {
1087	case htons(ETH_P_IP): {
1088		const struct iphdr *iph;
1089		struct iphdr _iph;
1090
1091		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1092		if (!iph || iph->ihl < 5) {
1093			fdret = FLOW_DISSECT_RET_OUT_BAD;
1094			break;
1095		}
1096
1097		nhoff += iph->ihl * 4;
1098
1099		ip_proto = iph->protocol;
1100
1101		if (dissector_uses_key(flow_dissector,
1102				       FLOW_DISSECTOR_KEY_IPV4_ADDRS)) {
1103			key_addrs = skb_flow_dissector_target(flow_dissector,
1104							      FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1105							      target_container);
1106
1107			memcpy(&key_addrs->v4addrs.src, &iph->saddr,
1108			       sizeof(key_addrs->v4addrs.src));
1109			memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
1110			       sizeof(key_addrs->v4addrs.dst));
1111			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
1112		}
1113
1114		__skb_flow_dissect_ipv4(skb, flow_dissector,
1115					target_container, data, iph);
1116
1117		if (ip_is_fragment(iph)) {
1118			key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1119
1120			if (iph->frag_off & htons(IP_OFFSET)) {
1121				fdret = FLOW_DISSECT_RET_OUT_GOOD;
1122				break;
1123			} else {
1124				key_control->flags |= FLOW_DIS_FIRST_FRAG;
1125				if (!(flags &
1126				      FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
1127					fdret = FLOW_DISSECT_RET_OUT_GOOD;
1128					break;
1129				}
1130			}
1131		}
1132
1133		break;
1134	}
1135	case htons(ETH_P_IPV6): {
1136		const struct ipv6hdr *iph;
1137		struct ipv6hdr _iph;
1138
1139		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
1140		if (!iph) {
1141			fdret = FLOW_DISSECT_RET_OUT_BAD;
1142			break;
1143		}
1144
1145		ip_proto = iph->nexthdr;
1146		nhoff += sizeof(struct ipv6hdr);
1147
1148		if (dissector_uses_key(flow_dissector,
1149				       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
1150			key_addrs = skb_flow_dissector_target(flow_dissector,
1151							      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1152							      target_container);
1153
1154			memcpy(&key_addrs->v6addrs.src, &iph->saddr,
1155			       sizeof(key_addrs->v6addrs.src));
1156			memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
1157			       sizeof(key_addrs->v6addrs.dst));
1158			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1159		}
1160
1161		if ((dissector_uses_key(flow_dissector,
1162					FLOW_DISSECTOR_KEY_FLOW_LABEL) ||
1163		     (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL)) &&
1164		    ip6_flowlabel(iph)) {
1165			__be32 flow_label = ip6_flowlabel(iph);
1166
1167			if (dissector_uses_key(flow_dissector,
1168					       FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
1169				key_tags = skb_flow_dissector_target(flow_dissector,
1170								     FLOW_DISSECTOR_KEY_FLOW_LABEL,
1171								     target_container);
1172				key_tags->flow_label = ntohl(flow_label);
1173			}
1174			if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
1175				fdret = FLOW_DISSECT_RET_OUT_GOOD;
1176				break;
1177			}
1178		}
1179
1180		__skb_flow_dissect_ipv6(skb, flow_dissector,
1181					target_container, data, iph);
1182
1183		break;
1184	}
1185	case htons(ETH_P_8021AD):
1186	case htons(ETH_P_8021Q): {
1187		const struct vlan_hdr *vlan = NULL;
1188		struct vlan_hdr _vlan;
1189		__be16 saved_vlan_tpid = proto;
1190
1191		if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
1192		    skb && skb_vlan_tag_present(skb)) {
1193			proto = skb->protocol;
1194		} else {
1195			vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
1196						    data, hlen, &_vlan);
1197			if (!vlan) {
1198				fdret = FLOW_DISSECT_RET_OUT_BAD;
1199				break;
1200			}
1201
1202			proto = vlan->h_vlan_encapsulated_proto;
1203			nhoff += sizeof(*vlan);
1204		}
1205
1206		if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_NUM_OF_VLANS) &&
1207		    !(key_control->flags & FLOW_DIS_ENCAPSULATION)) {
1208			struct flow_dissector_key_num_of_vlans *key_nvs;
1209
1210			key_nvs = skb_flow_dissector_target(flow_dissector,
1211							    FLOW_DISSECTOR_KEY_NUM_OF_VLANS,
1212							    target_container);
1213			key_nvs->num_of_vlans++;
1214		}
1215
1216		if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX) {
1217			dissector_vlan = FLOW_DISSECTOR_KEY_VLAN;
1218		} else if (dissector_vlan == FLOW_DISSECTOR_KEY_VLAN) {
1219			dissector_vlan = FLOW_DISSECTOR_KEY_CVLAN;
1220		} else {
1221			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1222			break;
1223		}
1224
1225		if (dissector_uses_key(flow_dissector, dissector_vlan)) {
1226			key_vlan = skb_flow_dissector_target(flow_dissector,
1227							     dissector_vlan,
1228							     target_container);
1229
1230			if (!vlan) {
1231				key_vlan->vlan_id = skb_vlan_tag_get_id(skb);
1232				key_vlan->vlan_priority = skb_vlan_tag_get_prio(skb);
1233			} else {
1234				key_vlan->vlan_id = ntohs(vlan->h_vlan_TCI) &
1235					VLAN_VID_MASK;
1236				key_vlan->vlan_priority =
1237					(ntohs(vlan->h_vlan_TCI) &
1238					 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
1239			}
1240			key_vlan->vlan_tpid = saved_vlan_tpid;
1241			key_vlan->vlan_eth_type = proto;
1242		}
1243
1244		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1245		break;
1246	}
1247	case htons(ETH_P_PPP_SES): {
1248		struct {
1249			struct pppoe_hdr hdr;
1250			__be16 proto;
1251		} *hdr, _hdr;
1252		u16 ppp_proto;
1253
1254		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
1255		if (!hdr) {
1256			fdret = FLOW_DISSECT_RET_OUT_BAD;
1257			break;
1258		}
1259
1260		if (!is_pppoe_ses_hdr_valid(&hdr->hdr)) {
1261			fdret = FLOW_DISSECT_RET_OUT_BAD;
1262			break;
1263		}
1264
1265		/* least significant bit of the most significant octet
1266		 * indicates if protocol field was compressed
1267		 */
1268		ppp_proto = ntohs(hdr->proto);
1269		if (ppp_proto & 0x0100) {
1270			ppp_proto = ppp_proto >> 8;
1271			nhoff += PPPOE_SES_HLEN - 1;
1272		} else {
1273			nhoff += PPPOE_SES_HLEN;
1274		}
1275
1276		if (ppp_proto == PPP_IP) {
1277			proto = htons(ETH_P_IP);
1278			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1279		} else if (ppp_proto == PPP_IPV6) {
1280			proto = htons(ETH_P_IPV6);
1281			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1282		} else if (ppp_proto == PPP_MPLS_UC) {
1283			proto = htons(ETH_P_MPLS_UC);
1284			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1285		} else if (ppp_proto == PPP_MPLS_MC) {
1286			proto = htons(ETH_P_MPLS_MC);
1287			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1288		} else if (ppp_proto_is_valid(ppp_proto)) {
1289			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1290		} else {
1291			fdret = FLOW_DISSECT_RET_OUT_BAD;
1292			break;
1293		}
1294
1295		if (dissector_uses_key(flow_dissector,
1296				       FLOW_DISSECTOR_KEY_PPPOE)) {
1297			struct flow_dissector_key_pppoe *key_pppoe;
1298
1299			key_pppoe = skb_flow_dissector_target(flow_dissector,
1300							      FLOW_DISSECTOR_KEY_PPPOE,
1301							      target_container);
1302			key_pppoe->session_id = hdr->hdr.sid;
1303			key_pppoe->ppp_proto = htons(ppp_proto);
1304			key_pppoe->type = htons(ETH_P_PPP_SES);
1305		}
1306		break;
1307	}
1308	case htons(ETH_P_TIPC): {
1309		struct tipc_basic_hdr *hdr, _hdr;
1310
1311		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
1312					   data, hlen, &_hdr);
1313		if (!hdr) {
1314			fdret = FLOW_DISSECT_RET_OUT_BAD;
1315			break;
1316		}
1317
1318		if (dissector_uses_key(flow_dissector,
1319				       FLOW_DISSECTOR_KEY_TIPC)) {
1320			key_addrs = skb_flow_dissector_target(flow_dissector,
1321							      FLOW_DISSECTOR_KEY_TIPC,
1322							      target_container);
1323			key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
1324			key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
1325		}
1326		fdret = FLOW_DISSECT_RET_OUT_GOOD;
1327		break;
1328	}
1329
1330	case htons(ETH_P_MPLS_UC):
1331	case htons(ETH_P_MPLS_MC):
1332		fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
1333						target_container, data,
1334						nhoff, hlen, mpls_lse,
1335						&mpls_el);
1336		nhoff += sizeof(struct mpls_label);
1337		mpls_lse++;
1338		break;
1339	case htons(ETH_P_FCOE):
1340		if ((hlen - nhoff) < FCOE_HEADER_LEN) {
1341			fdret = FLOW_DISSECT_RET_OUT_BAD;
1342			break;
1343		}
1344
1345		nhoff += FCOE_HEADER_LEN;
1346		fdret = FLOW_DISSECT_RET_OUT_GOOD;
1347		break;
1348
1349	case htons(ETH_P_ARP):
1350	case htons(ETH_P_RARP):
1351		fdret = __skb_flow_dissect_arp(skb, flow_dissector,
1352					       target_container, data,
1353					       nhoff, hlen);
1354		break;
1355
1356	case htons(ETH_P_BATMAN):
1357		fdret = __skb_flow_dissect_batadv(skb, key_control, data,
1358						  &proto, &nhoff, hlen, flags);
1359		break;
1360
1361	case htons(ETH_P_1588): {
1362		struct ptp_header *hdr, _hdr;
1363
1364		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
1365					   hlen, &_hdr);
1366		if (!hdr) {
1367			fdret = FLOW_DISSECT_RET_OUT_BAD;
1368			break;
1369		}
1370
1371		nhoff += ntohs(hdr->message_length);
1372		fdret = FLOW_DISSECT_RET_OUT_GOOD;
1373		break;
1374	}
1375
1376	case htons(ETH_P_PRP):
1377	case htons(ETH_P_HSR): {
1378		struct hsr_tag *hdr, _hdr;
1379
1380		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen,
1381					   &_hdr);
1382		if (!hdr) {
1383			fdret = FLOW_DISSECT_RET_OUT_BAD;
1384			break;
1385		}
1386
1387		proto = hdr->encap_proto;
1388		nhoff += HSR_HLEN;
1389		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1390		break;
1391	}
1392
 
 
 
 
 
 
1393	default:
1394		fdret = FLOW_DISSECT_RET_OUT_BAD;
1395		break;
1396	}
1397
1398	/* Process result of proto processing */
1399	switch (fdret) {
1400	case FLOW_DISSECT_RET_OUT_GOOD:
1401		goto out_good;
1402	case FLOW_DISSECT_RET_PROTO_AGAIN:
1403		if (skb_flow_dissect_allowed(&num_hdrs))
1404			goto proto_again;
1405		goto out_good;
1406	case FLOW_DISSECT_RET_CONTINUE:
1407	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1408		break;
1409	case FLOW_DISSECT_RET_OUT_BAD:
1410	default:
1411		goto out_bad;
1412	}
1413
1414ip_proto_again:
1415	fdret = FLOW_DISSECT_RET_CONTINUE;
1416
1417	switch (ip_proto) {
1418	case IPPROTO_GRE:
1419		if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1420			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1421			break;
1422		}
1423
1424		fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
1425					       target_container, data,
1426					       &proto, &nhoff, &hlen, flags);
1427		break;
1428
1429	case NEXTHDR_HOP:
1430	case NEXTHDR_ROUTING:
1431	case NEXTHDR_DEST: {
1432		u8 _opthdr[2], *opthdr;
1433
1434		if (proto != htons(ETH_P_IPV6))
1435			break;
1436
1437		opthdr = __skb_header_pointer(skb, nhoff, sizeof(_opthdr),
1438					      data, hlen, &_opthdr);
1439		if (!opthdr) {
1440			fdret = FLOW_DISSECT_RET_OUT_BAD;
1441			break;
1442		}
1443
1444		ip_proto = opthdr[0];
1445		nhoff += (opthdr[1] + 1) << 3;
1446
1447		fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1448		break;
1449	}
1450	case NEXTHDR_FRAGMENT: {
1451		struct frag_hdr _fh, *fh;
1452
1453		if (proto != htons(ETH_P_IPV6))
1454			break;
1455
1456		fh = __skb_header_pointer(skb, nhoff, sizeof(_fh),
1457					  data, hlen, &_fh);
1458
1459		if (!fh) {
1460			fdret = FLOW_DISSECT_RET_OUT_BAD;
1461			break;
1462		}
1463
1464		key_control->flags |= FLOW_DIS_IS_FRAGMENT;
1465
1466		nhoff += sizeof(_fh);
1467		ip_proto = fh->nexthdr;
1468
1469		if (!(fh->frag_off & htons(IP6_OFFSET))) {
1470			key_control->flags |= FLOW_DIS_FIRST_FRAG;
1471			if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
1472				fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
1473				break;
1474			}
1475		}
1476
1477		fdret = FLOW_DISSECT_RET_OUT_GOOD;
1478		break;
1479	}
1480	case IPPROTO_IPIP:
1481		if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1482			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1483			break;
1484		}
1485
1486		proto = htons(ETH_P_IP);
1487
1488		key_control->flags |= FLOW_DIS_ENCAPSULATION;
1489		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1490			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1491			break;
1492		}
1493
1494		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1495		break;
1496
1497	case IPPROTO_IPV6:
1498		if (flags & FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP) {
1499			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1500			break;
1501		}
1502
1503		proto = htons(ETH_P_IPV6);
1504
1505		key_control->flags |= FLOW_DIS_ENCAPSULATION;
1506		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
1507			fdret = FLOW_DISSECT_RET_OUT_GOOD;
1508			break;
1509		}
1510
1511		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1512		break;
1513
1514
1515	case IPPROTO_MPLS:
1516		proto = htons(ETH_P_MPLS_UC);
1517		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
1518		break;
1519
1520	case IPPROTO_TCP:
1521		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
1522				       data, nhoff, hlen);
1523		break;
1524
1525	case IPPROTO_ICMP:
1526	case IPPROTO_ICMPV6:
1527		__skb_flow_dissect_icmp(skb, flow_dissector, target_container,
1528					data, nhoff, hlen);
1529		break;
1530	case IPPROTO_L2TP:
1531		__skb_flow_dissect_l2tpv3(skb, flow_dissector, target_container,
1532					  data, nhoff, hlen);
1533		break;
1534
 
 
 
 
 
 
 
1535	default:
1536		break;
1537	}
1538
1539	if (!(key_control->flags & FLOW_DIS_IS_FRAGMENT))
1540		__skb_flow_dissect_ports(skb, flow_dissector, target_container,
1541					 data, nhoff, ip_proto, hlen);
1542
1543	/* Process result of IP proto processing */
1544	switch (fdret) {
1545	case FLOW_DISSECT_RET_PROTO_AGAIN:
1546		if (skb_flow_dissect_allowed(&num_hdrs))
1547			goto proto_again;
1548		break;
1549	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
1550		if (skb_flow_dissect_allowed(&num_hdrs))
1551			goto ip_proto_again;
1552		break;
1553	case FLOW_DISSECT_RET_OUT_GOOD:
1554	case FLOW_DISSECT_RET_CONTINUE:
1555		break;
1556	case FLOW_DISSECT_RET_OUT_BAD:
1557	default:
1558		goto out_bad;
1559	}
1560
1561out_good:
1562	ret = true;
1563
1564out:
1565	key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
1566	key_basic->n_proto = proto;
1567	key_basic->ip_proto = ip_proto;
1568
1569	return ret;
1570
1571out_bad:
1572	ret = false;
1573	goto out;
1574}
1575EXPORT_SYMBOL(__skb_flow_dissect);
1576
1577static siphash_aligned_key_t hashrnd;
1578static __always_inline void __flow_hash_secret_init(void)
1579{
1580	net_get_random_once(&hashrnd, sizeof(hashrnd));
1581}
1582
1583static const void *flow_keys_hash_start(const struct flow_keys *flow)
1584{
1585	BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
1586	return &flow->FLOW_KEYS_HASH_START_FIELD;
1587}
1588
1589static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
1590{
1591	size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
1592
1593	BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
1594
1595	switch (flow->control.addr_type) {
1596	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1597		diff -= sizeof(flow->addrs.v4addrs);
1598		break;
1599	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1600		diff -= sizeof(flow->addrs.v6addrs);
1601		break;
1602	case FLOW_DISSECTOR_KEY_TIPC:
1603		diff -= sizeof(flow->addrs.tipckey);
1604		break;
1605	}
1606	return sizeof(*flow) - diff;
1607}
1608
1609__be32 flow_get_u32_src(const struct flow_keys *flow)
1610{
1611	switch (flow->control.addr_type) {
1612	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1613		return flow->addrs.v4addrs.src;
1614	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1615		return (__force __be32)ipv6_addr_hash(
1616			&flow->addrs.v6addrs.src);
1617	case FLOW_DISSECTOR_KEY_TIPC:
1618		return flow->addrs.tipckey.key;
1619	default:
1620		return 0;
1621	}
1622}
1623EXPORT_SYMBOL(flow_get_u32_src);
1624
1625__be32 flow_get_u32_dst(const struct flow_keys *flow)
1626{
1627	switch (flow->control.addr_type) {
1628	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1629		return flow->addrs.v4addrs.dst;
1630	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1631		return (__force __be32)ipv6_addr_hash(
1632			&flow->addrs.v6addrs.dst);
1633	default:
1634		return 0;
1635	}
1636}
1637EXPORT_SYMBOL(flow_get_u32_dst);
1638
1639/* Sort the source and destination IP and the ports,
1640 * to have consistent hash within the two directions
1641 */
1642static inline void __flow_hash_consistentify(struct flow_keys *keys)
1643{
1644	int addr_diff, i;
1645
1646	switch (keys->control.addr_type) {
1647	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
1648		if ((__force u32)keys->addrs.v4addrs.dst <
1649		    (__force u32)keys->addrs.v4addrs.src)
1650			swap(keys->addrs.v4addrs.src, keys->addrs.v4addrs.dst);
1651
1652		if ((__force u16)keys->ports.dst <
1653		    (__force u16)keys->ports.src) {
1654			swap(keys->ports.src, keys->ports.dst);
1655		}
1656		break;
1657	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
1658		addr_diff = memcmp(&keys->addrs.v6addrs.dst,
1659				   &keys->addrs.v6addrs.src,
1660				   sizeof(keys->addrs.v6addrs.dst));
1661		if (addr_diff < 0) {
1662			for (i = 0; i < 4; i++)
1663				swap(keys->addrs.v6addrs.src.s6_addr32[i],
1664				     keys->addrs.v6addrs.dst.s6_addr32[i]);
1665		}
1666		if ((__force u16)keys->ports.dst <
1667		    (__force u16)keys->ports.src) {
1668			swap(keys->ports.src, keys->ports.dst);
1669		}
1670		break;
1671	}
1672}
1673
1674static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
1675					const siphash_key_t *keyval)
1676{
1677	u32 hash;
1678
1679	__flow_hash_consistentify(keys);
1680
1681	hash = siphash(flow_keys_hash_start(keys),
1682		       flow_keys_hash_length(keys), keyval);
1683	if (!hash)
1684		hash = 1;
1685
1686	return hash;
1687}
1688
1689u32 flow_hash_from_keys(struct flow_keys *keys)
1690{
1691	__flow_hash_secret_init();
1692	return __flow_hash_from_keys(keys, &hashrnd);
1693}
1694EXPORT_SYMBOL(flow_hash_from_keys);
1695
1696static inline u32 ___skb_get_hash(const struct sk_buff *skb,
1697				  struct flow_keys *keys,
1698				  const siphash_key_t *keyval)
1699{
1700	skb_flow_dissect_flow_keys(skb, keys,
1701				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1702
1703	return __flow_hash_from_keys(keys, keyval);
1704}
1705
1706struct _flow_keys_digest_data {
1707	__be16	n_proto;
1708	u8	ip_proto;
1709	u8	padding;
1710	__be32	ports;
1711	__be32	src;
1712	__be32	dst;
1713};
1714
1715void make_flow_keys_digest(struct flow_keys_digest *digest,
1716			   const struct flow_keys *flow)
1717{
1718	struct _flow_keys_digest_data *data =
1719	    (struct _flow_keys_digest_data *)digest;
1720
1721	BUILD_BUG_ON(sizeof(*data) > sizeof(*digest));
1722
1723	memset(digest, 0, sizeof(*digest));
1724
1725	data->n_proto = flow->basic.n_proto;
1726	data->ip_proto = flow->basic.ip_proto;
1727	data->ports = flow->ports.ports;
1728	data->src = flow->addrs.v4addrs.src;
1729	data->dst = flow->addrs.v4addrs.dst;
1730}
1731EXPORT_SYMBOL(make_flow_keys_digest);
1732
1733static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
1734
1735u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
1736{
1737	struct flow_keys keys;
1738
1739	__flow_hash_secret_init();
1740
1741	memset(&keys, 0, sizeof(keys));
1742	__skb_flow_dissect(NULL, skb, &flow_keys_dissector_symmetric,
1743			   &keys, NULL, 0, 0, 0,
1744			   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
1745
1746	return __flow_hash_from_keys(&keys, &hashrnd);
1747}
1748EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
1749
1750/**
1751 * __skb_get_hash: calculate a flow hash
1752 * @skb: sk_buff to calculate flow hash from
1753 *
1754 * This function calculates a flow hash based on src/dst addresses
1755 * and src/dst port numbers.  Sets hash in skb to non-zero hash value
1756 * on success, zero indicates no valid hash.  Also, sets l4_hash in skb
1757 * if hash is a canonical 4-tuple hash over transport ports.
1758 */
1759void __skb_get_hash(struct sk_buff *skb)
1760{
1761	struct flow_keys keys;
1762	u32 hash;
1763
1764	__flow_hash_secret_init();
1765
1766	hash = ___skb_get_hash(skb, &keys, &hashrnd);
1767
1768	__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
1769}
1770EXPORT_SYMBOL(__skb_get_hash);
1771
1772__u32 skb_get_hash_perturb(const struct sk_buff *skb,
1773			   const siphash_key_t *perturb)
1774{
1775	struct flow_keys keys;
1776
1777	return ___skb_get_hash(skb, &keys, perturb);
1778}
1779EXPORT_SYMBOL(skb_get_hash_perturb);
1780
1781u32 __skb_get_poff(const struct sk_buff *skb, const void *data,
1782		   const struct flow_keys_basic *keys, int hlen)
1783{
1784	u32 poff = keys->control.thoff;
1785
1786	/* skip L4 headers for fragments after the first */
1787	if ((keys->control.flags & FLOW_DIS_IS_FRAGMENT) &&
1788	    !(keys->control.flags & FLOW_DIS_FIRST_FRAG))
1789		return poff;
1790
1791	switch (keys->basic.ip_proto) {
1792	case IPPROTO_TCP: {
1793		/* access doff as u8 to avoid unaligned access */
1794		const u8 *doff;
1795		u8 _doff;
1796
1797		doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
1798					    data, hlen, &_doff);
1799		if (!doff)
1800			return poff;
1801
1802		poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
1803		break;
1804	}
1805	case IPPROTO_UDP:
1806	case IPPROTO_UDPLITE:
1807		poff += sizeof(struct udphdr);
1808		break;
1809	/* For the rest, we do not really care about header
1810	 * extensions at this point for now.
1811	 */
1812	case IPPROTO_ICMP:
1813		poff += sizeof(struct icmphdr);
1814		break;
1815	case IPPROTO_ICMPV6:
1816		poff += sizeof(struct icmp6hdr);
1817		break;
1818	case IPPROTO_IGMP:
1819		poff += sizeof(struct igmphdr);
1820		break;
1821	case IPPROTO_DCCP:
1822		poff += sizeof(struct dccp_hdr);
1823		break;
1824	case IPPROTO_SCTP:
1825		poff += sizeof(struct sctphdr);
1826		break;
1827	}
1828
1829	return poff;
1830}
1831
1832/**
1833 * skb_get_poff - get the offset to the payload
1834 * @skb: sk_buff to get the payload offset from
1835 *
1836 * The function will get the offset to the payload as far as it could
1837 * be dissected.  The main user is currently BPF, so that we can dynamically
1838 * truncate packets without needing to push actual payload to the user
1839 * space and can analyze headers only, instead.
1840 */
1841u32 skb_get_poff(const struct sk_buff *skb)
1842{
1843	struct flow_keys_basic keys;
1844
1845	if (!skb_flow_dissect_flow_keys_basic(NULL, skb, &keys,
1846					      NULL, 0, 0, 0, 0))
1847		return 0;
1848
1849	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
1850}
1851
1852__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
1853{
1854	memset(keys, 0, sizeof(*keys));
1855
1856	memcpy(&keys->addrs.v6addrs.src, &fl6->saddr,
1857	    sizeof(keys->addrs.v6addrs.src));
1858	memcpy(&keys->addrs.v6addrs.dst, &fl6->daddr,
1859	    sizeof(keys->addrs.v6addrs.dst));
1860	keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
1861	keys->ports.src = fl6->fl6_sport;
1862	keys->ports.dst = fl6->fl6_dport;
1863	keys->keyid.keyid = fl6->fl6_gre_key;
1864	keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
1865	keys->basic.ip_proto = fl6->flowi6_proto;
1866
1867	return flow_hash_from_keys(keys);
1868}
1869EXPORT_SYMBOL(__get_hash_from_flowi6);
1870
1871static const struct flow_dissector_key flow_keys_dissector_keys[] = {
1872	{
1873		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
1874		.offset = offsetof(struct flow_keys, control),
1875	},
1876	{
1877		.key_id = FLOW_DISSECTOR_KEY_BASIC,
1878		.offset = offsetof(struct flow_keys, basic),
1879	},
1880	{
1881		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1882		.offset = offsetof(struct flow_keys, addrs.v4addrs),
1883	},
1884	{
1885		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1886		.offset = offsetof(struct flow_keys, addrs.v6addrs),
1887	},
1888	{
1889		.key_id = FLOW_DISSECTOR_KEY_TIPC,
1890		.offset = offsetof(struct flow_keys, addrs.tipckey),
1891	},
1892	{
1893		.key_id = FLOW_DISSECTOR_KEY_PORTS,
1894		.offset = offsetof(struct flow_keys, ports),
1895	},
1896	{
1897		.key_id = FLOW_DISSECTOR_KEY_VLAN,
1898		.offset = offsetof(struct flow_keys, vlan),
1899	},
1900	{
1901		.key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
1902		.offset = offsetof(struct flow_keys, tags),
1903	},
1904	{
1905		.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
1906		.offset = offsetof(struct flow_keys, keyid),
1907	},
1908};
1909
1910static const struct flow_dissector_key flow_keys_dissector_symmetric_keys[] = {
1911	{
1912		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
1913		.offset = offsetof(struct flow_keys, control),
1914	},
1915	{
1916		.key_id = FLOW_DISSECTOR_KEY_BASIC,
1917		.offset = offsetof(struct flow_keys, basic),
1918	},
1919	{
1920		.key_id = FLOW_DISSECTOR_KEY_IPV4_ADDRS,
1921		.offset = offsetof(struct flow_keys, addrs.v4addrs),
1922	},
1923	{
1924		.key_id = FLOW_DISSECTOR_KEY_IPV6_ADDRS,
1925		.offset = offsetof(struct flow_keys, addrs.v6addrs),
1926	},
1927	{
1928		.key_id = FLOW_DISSECTOR_KEY_PORTS,
1929		.offset = offsetof(struct flow_keys, ports),
1930	},
1931};
1932
1933static const struct flow_dissector_key flow_keys_basic_dissector_keys[] = {
1934	{
1935		.key_id = FLOW_DISSECTOR_KEY_CONTROL,
1936		.offset = offsetof(struct flow_keys, control),
1937	},
1938	{
1939		.key_id = FLOW_DISSECTOR_KEY_BASIC,
1940		.offset = offsetof(struct flow_keys, basic),
1941	},
1942};
1943
1944struct flow_dissector flow_keys_dissector __read_mostly;
1945EXPORT_SYMBOL(flow_keys_dissector);
1946
1947struct flow_dissector flow_keys_basic_dissector __read_mostly;
1948EXPORT_SYMBOL(flow_keys_basic_dissector);
1949
1950static int __init init_default_flow_dissectors(void)
1951{
1952	skb_flow_dissector_init(&flow_keys_dissector,
1953				flow_keys_dissector_keys,
1954				ARRAY_SIZE(flow_keys_dissector_keys));
1955	skb_flow_dissector_init(&flow_keys_dissector_symmetric,
1956				flow_keys_dissector_symmetric_keys,
1957				ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
1958	skb_flow_dissector_init(&flow_keys_basic_dissector,
1959				flow_keys_basic_dissector_keys,
1960				ARRAY_SIZE(flow_keys_basic_dissector_keys));
1961	return 0;
1962}
1963core_initcall(init_default_flow_dissectors);