Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1470 insertions, 0 deletions

diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
new file mode 100644
index 000000000..da860a680
--- /dev/null
+++ b/net/core/flow_dissector.c
@@ -0,0 +1,1470 @@
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/export.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <linux/if_vlan.h>
+#include <net/dsa.h>
+#include <net/dst_metadata.h>
+#include <net/ip.h>
+#include <net/ipv6.h>
+#include <net/gre.h>
+#include <net/pptp.h>
+#include <net/tipc.h>
+#include <linux/igmp.h>
+#include <linux/icmp.h>
+#include <linux/sctp.h>
+#include <linux/dccp.h>
+#include <linux/if_tunnel.h>
+#include <linux/if_pppox.h>
+#include <linux/ppp_defs.h>
+#include <linux/stddef.h>
+#include <linux/if_ether.h>
+#include <linux/mpls.h>
+#include <linux/tcp.h>
+#include <net/flow_dissector.h>
+#include <scsi/fc/fc_fcoe.h>
+#include <uapi/linux/batadv_packet.h>
+
+static void dissector_set_key(struct flow_dissector *flow_dissector,
+			      enum flow_dissector_key_id key_id)
+{
+	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);
+		BUG_ON(dissector_uses_key(flow_dissector,
+					  key->key_id));
+
+		dissector_set_key(flow_dissector, key->key_id);
+		flow_dissector->offset[key->key_id] = key->offset;
+	}
+
+	/* Ensure that the dissector always includes control and basic key.
+	 * That way we are able to avoid handling lack of these in fast path.
+	 */
+	BUG_ON(!dissector_uses_key(flow_dissector,
+				   FLOW_DISSECTOR_KEY_CONTROL));
+	BUG_ON(!dissector_uses_key(flow_dissector,
+				   FLOW_DISSECTOR_KEY_BASIC));
+}
+EXPORT_SYMBOL(skb_flow_dissector_init);
+
+/**
+ * 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
+ */
+static __be16 skb_flow_get_be16(const struct sk_buff *skb, int poff,
+				void *data, int hlen)
+{
+	__be16 *u, _u;
+
+	u = __skb_header_pointer(skb, poff, sizeof(_u), data, hlen, &_u);
+	if (u)
+		return *u;
+
+	return 0;
+}
+
+/**
+ * __skb_flow_get_ports - extract the upper layer ports and return them
+ * @skb: sk_buff to extract the ports from
+ * @thoff: transport header offset
+ * @ip_proto: protocol for which to get port offset
+ * @data: raw buffer pointer to the packet, if NULL use skb->data
+ * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
+ *
+ * The function will try to retrieve the ports at offset thoff + poff where poff
+ * is the protocol port offset returned from proto_ports_offset
+ */
+__be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
+			    void *data, int hlen)
+{
+	int poff = proto_ports_offset(ip_proto);
+
+	if (!data) {
+		data = skb->data;
+		hlen = skb_headlen(skb);
+	}
+
+	if (poff >= 0) {
+		__be32 *ports, _ports;
+
+		ports = __skb_header_pointer(skb, thoff + poff,
+					     sizeof(_ports), data, hlen, &_ports);
+		if (ports)
+			return *ports;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(__skb_flow_get_ports);
+
+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;
+}
+
+void
+skb_flow_dissect_tunnel_info(const struct sk_buff *skb,
+			     struct flow_dissector *flow_dissector,
+			     void *target_container)
+{
+	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) &&
+	    !dissector_uses_key(flow_dissector,
+				FLOW_DISSECTOR_KEY_ENC_IP) &&
+	    !dissector_uses_key(flow_dissector,
+				FLOW_DISSECTOR_KEY_ENC_OPTS))
+		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;
+	}
+
+	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_IP)) {
+		struct flow_dissector_key_ip *ip;
+
+		ip = skb_flow_dissector_target(flow_dissector,
+					       FLOW_DISSECTOR_KEY_ENC_IP,
+					       target_container);
+		ip->tos = key->tos;
+		ip->ttl = key->ttl;
+	}
+
+	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_ENC_OPTS)) {
+		struct flow_dissector_key_enc_opts *enc_opt;
+
+		enc_opt = skb_flow_dissector_target(flow_dissector,
+						    FLOW_DISSECTOR_KEY_ENC_OPTS,
+						    target_container);
+
+		if (info->options_len) {
+			enc_opt->len = info->options_len;
+			ip_tunnel_info_opts_get(enc_opt->data, info);
+			enc_opt->dst_opt_type = info->key.tun_flags &
+						TUNNEL_OPTIONS_PRESENT;
+		}
+	}
+}
+EXPORT_SYMBOL(skb_flow_dissect_tunnel_info);
+
+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];
+	u32 entry, label;
+
+	if (!dissector_uses_key(flow_dissector,
+				FLOW_DISSECTOR_KEY_MPLS_ENTROPY) &&
+	    !dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_MPLS))
+		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;
+
+	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) {
+		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;
+}
+
+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;
+	struct arphdr _arp;
+
+	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;
+}
+
+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;
+
+	return FLOW_DISSECT_RET_PROTO_AGAIN;
+}
+
+/**
+ * __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;
+}
+
+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));
+}
+
+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;
+}
+
+/* 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);
+}
+
+/**
+ * __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
+ * @flow_dissector: list of keys to dissect
+ * @target_container: target structure to put dissected values into
+ * @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)
+ *
+ * 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.
+ */
+bool __skb_flow_dissect(const struct sk_buff *skb,
+			struct flow_dissector *flow_dissector,
+			void *target_container,
+			void *data, __be16 proto, int nhoff, int hlen,
+			unsigned int flags)
+{
+	struct flow_dissector_key_control *key_control;
+	struct flow_dissector_key_basic *key_basic;
+	struct flow_dissector_key_addrs *key_addrs;
+	struct flow_dissector_key_ports *key_ports;
+	struct flow_dissector_key_icmp *key_icmp;
+	struct flow_dissector_key_tags *key_tags;
+	struct flow_dissector_key_vlan *key_vlan;
+	enum flow_dissect_ret fdret;
+	enum flow_dissector_key_id dissector_vlan = FLOW_DISSECTOR_KEY_MAX;
+	int num_hdrs = 0;
+	u8 ip_proto = 0;
+	bool ret;
+
+	if (!data) {
+		data = skb->data;
+		proto = skb_vlan_tag_present(skb) ?
+			 skb->vlan_proto : skb->protocol;
+		nhoff = skb_network_offset(skb);
+		hlen = skb_headlen(skb);
+#if IS_ENABLED(CONFIG_NET_DSA)
+		if (unlikely(skb->dev && netdev_uses_dsa(skb->dev) &&
+			     proto == htons(ETH_P_XDSA))) {
+			const struct dsa_device_ops *ops;
+			int offset = 0;
+
+			ops = skb->dev->dsa_ptr->tag_ops;
+			if (ops->flow_dissect &&
+			    !ops->flow_dissect(skb, &proto, &offset)) {
+				hlen -= offset;
+				nhoff += offset;
+			}
+		}
+#endif
+	}
+
+	/* 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);
+
+	/* 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);
+
+	if (dissector_uses_key(flow_dissector,
+			       FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
+		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));
+	}
+
+proto_again:
+	fdret = FLOW_DISSECT_RET_CONTINUE;
+
+	switch (proto) {
+	case htons(ETH_P_IP): {
+		const struct iphdr *iph;
+		struct iphdr _iph;
+
+		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
+		if (!iph || iph->ihl < 5) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		nhoff += iph->ihl * 4;
+
+		ip_proto = iph->protocol;
+
+		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.src, &iph->saddr,
+			       sizeof(key_addrs->v4addrs.src));
+			memcpy(&key_addrs->v4addrs.dst, &iph->daddr,
+			       sizeof(key_addrs->v4addrs.dst));
+			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+		}
+
+		if (ip_is_fragment(iph)) {
+			key_control->flags |= FLOW_DIS_IS_FRAGMENT;
+
+			if (iph->frag_off & htons(IP_OFFSET)) {
+				fdret = FLOW_DISSECT_RET_OUT_GOOD;
+				break;
+			} else {
+				key_control->flags |= FLOW_DIS_FIRST_FRAG;
+				if (!(flags &
+				      FLOW_DISSECTOR_F_PARSE_1ST_FRAG)) {
+					fdret = FLOW_DISSECT_RET_OUT_GOOD;
+					break;
+				}
+			}
+		}
+
+		__skb_flow_dissect_ipv4(skb, flow_dissector,
+					target_container, data, iph);
+
+		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3) {
+			fdret = FLOW_DISSECT_RET_OUT_GOOD;
+			break;
+		}
+
+		break;
+	}
+	case htons(ETH_P_IPV6): {
+		const struct ipv6hdr *iph;
+		struct ipv6hdr _iph;
+
+		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
+		if (!iph) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		ip_proto = iph->nexthdr;
+		nhoff += sizeof(struct ipv6hdr);
+
+		if (dissector_uses_key(flow_dissector,
+				       FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
+			key_addrs = skb_flow_dissector_target(flow_dissector,
+							      FLOW_DISSECTOR_KEY_IPV6_ADDRS,
+							      target_container);
+
+			memcpy(&key_addrs->v6addrs.src, &iph->saddr,
+			       sizeof(key_addrs->v6addrs.src));
+			memcpy(&key_addrs->v6addrs.dst, &iph->daddr,
+			       sizeof(key_addrs->v6addrs.dst));
+			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+		}
+
+		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);
+
+			if (dissector_uses_key(flow_dissector,
+					       FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
+				key_tags = skb_flow_dissector_target(flow_dissector,
+								     FLOW_DISSECTOR_KEY_FLOW_LABEL,
+								     target_container);
+				key_tags->flow_label = ntohl(flow_label);
+			}
+			if (flags & FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL) {
+				fdret = FLOW_DISSECT_RET_OUT_GOOD;
+				break;
+			}
+		}
+
+		__skb_flow_dissect_ipv6(skb, flow_dissector,
+					target_container, data, iph);
+
+		if (flags & FLOW_DISSECTOR_F_STOP_AT_L3)
+			fdret = FLOW_DISSECT_RET_OUT_GOOD;
+
+		break;
+	}
+	case htons(ETH_P_8021AD):
+	case htons(ETH_P_8021Q): {
+		const struct vlan_hdr *vlan = NULL;
+		struct vlan_hdr _vlan;
+		__be16 saved_vlan_tpid = proto;
+
+		if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
+		    skb && skb_vlan_tag_present(skb)) {
+			proto = skb->protocol;
+		} else {
+			vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
+						    data, hlen, &_vlan);
+			if (!vlan) {
+				fdret = FLOW_DISSECT_RET_OUT_BAD;
+				break;
+			}
+
+			proto = vlan->h_vlan_encapsulated_proto;
+			nhoff += sizeof(*vlan);
+		}
+
+		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)) {
+			key_vlan = skb_flow_dissector_target(flow_dissector,
+							     dissector_vlan,
+							     target_container);
+
+			if (!vlan) {
+				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) &
+					VLAN_VID_MASK;
+				key_vlan->vlan_priority =
+					(ntohs(vlan->h_vlan_TCI) &
+					 VLAN_PRIO_MASK) >> VLAN_PRIO_SHIFT;
+			}
+			key_vlan->vlan_tpid = saved_vlan_tpid;
+			key_vlan->vlan_eth_type = proto;
+		}
+
+		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+		break;
+	}
+	case htons(ETH_P_PPP_SES): {
+		struct {
+			struct pppoe_hdr hdr;
+			__be16 proto;
+		} *hdr, _hdr;
+		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
+		if (!hdr) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		proto = hdr->proto;
+		nhoff += PPPOE_SES_HLEN;
+		switch (proto) {
+		case htons(PPP_IP):
+			proto = htons(ETH_P_IP);
+			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+			break;
+		case htons(PPP_IPV6):
+			proto = htons(ETH_P_IPV6);
+			fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+			break;
+		default:
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+		break;
+	}
+	case htons(ETH_P_TIPC): {
+		struct tipc_basic_hdr *hdr, _hdr;
+
+		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr),
+					   data, hlen, &_hdr);
+		if (!hdr) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		if (dissector_uses_key(flow_dissector,
+				       FLOW_DISSECTOR_KEY_TIPC)) {
+			key_addrs = skb_flow_dissector_target(flow_dissector,
+							      FLOW_DISSECTOR_KEY_TIPC,
+							      target_container);
+			key_addrs->tipckey.key = tipc_hdr_rps_key(hdr);
+			key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC;
+		}
+		fdret = FLOW_DISSECT_RET_OUT_GOOD;
+		break;
+	}
+
+	case htons(ETH_P_MPLS_UC):
+	case htons(ETH_P_MPLS_MC):
+		fdret = __skb_flow_dissect_mpls(skb, flow_dissector,
+						target_container, data,
+						nhoff, hlen);
+		break;
+	case htons(ETH_P_FCOE):
+		if ((hlen - nhoff) < FCOE_HEADER_LEN) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		nhoff += FCOE_HEADER_LEN;
+		fdret = FLOW_DISSECT_RET_OUT_GOOD;
+		break;
+
+	case htons(ETH_P_ARP):
+	case htons(ETH_P_RARP):
+		fdret = __skb_flow_dissect_arp(skb, flow_dissector,
+					       target_container, data,
+					       nhoff, hlen);
+		break;
+
+	case htons(ETH_P_BATMAN):
+		fdret = __skb_flow_dissect_batadv(skb, key_control, data,
+						  &proto, &nhoff, hlen, flags);
+		break;
+
+	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:
+		if (skb_flow_dissect_allowed(&num_hdrs))
+			goto proto_again;
+		goto out_good;
+	case FLOW_DISSECT_RET_CONTINUE:
+	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
+		break;
+	case FLOW_DISSECT_RET_OUT_BAD:
+	default:
+		goto out_bad;
+	}
+
+ip_proto_again:
+	fdret = FLOW_DISSECT_RET_CONTINUE;
+
+	switch (ip_proto) {
+	case IPPROTO_GRE:
+		fdret = __skb_flow_dissect_gre(skb, key_control, flow_dissector,
+					       target_container, data,
+					       &proto, &nhoff, &hlen, flags);
+		break;
+
+	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);
+		if (!opthdr) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		ip_proto = opthdr[0];
+		nhoff += (opthdr[1] + 1) << 3;
+
+		fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
+		break;
+	}
+	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);
+
+		if (!fh) {
+			fdret = FLOW_DISSECT_RET_OUT_BAD;
+			break;
+		}
+
+		key_control->flags |= FLOW_DIS_IS_FRAGMENT;
+
+		nhoff += sizeof(_fh);
+		ip_proto = fh->nexthdr;
+
+		if (!(fh->frag_off & htons(IP6_OFFSET))) {
+			key_control->flags |= FLOW_DIS_FIRST_FRAG;
+			if (flags & FLOW_DISSECTOR_F_PARSE_1ST_FRAG) {
+				fdret = FLOW_DISSECT_RET_IPPROTO_AGAIN;
+				break;
+			}
+		}
+
+		fdret = FLOW_DISSECT_RET_OUT_GOOD;
+		break;
+	}
+	case IPPROTO_IPIP:
+		proto = htons(ETH_P_IP);
+
+		key_control->flags |= FLOW_DIS_ENCAPSULATION;
+		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
+			fdret = FLOW_DISSECT_RET_OUT_GOOD;
+			break;
+		}
+
+		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+		break;
+
+	case IPPROTO_IPV6:
+		proto = htons(ETH_P_IPV6);
+
+		key_control->flags |= FLOW_DIS_ENCAPSULATION;
+		if (flags & FLOW_DISSECTOR_F_STOP_AT_ENCAP) {
+			fdret = FLOW_DISSECT_RET_OUT_GOOD;
+			break;
+		}
+
+		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+		break;
+
+
+	case IPPROTO_MPLS:
+		proto = htons(ETH_P_MPLS_UC);
+		fdret = FLOW_DISSECT_RET_PROTO_AGAIN;
+		break;
+
+	case IPPROTO_TCP:
+		__skb_flow_dissect_tcp(skb, flow_dissector, target_container,
+				       data, nhoff, hlen);
+		break;
+
+	default:
+		break;
+	}
+
+	if (dissector_uses_key(flow_dissector, FLOW_DISSECTOR_KEY_PORTS) &&
+	    !(key_control->flags & FLOW_DIS_IS_FRAGMENT)) {
+		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);
+	}
+
+	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);
+	}
+
+	/* Process result of IP proto processing */
+	switch (fdret) {
+	case FLOW_DISSECT_RET_PROTO_AGAIN:
+		if (skb_flow_dissect_allowed(&num_hdrs))
+			goto proto_again;
+		break;
+	case FLOW_DISSECT_RET_IPPROTO_AGAIN:
+		if (skb_flow_dissect_allowed(&num_hdrs))
+			goto ip_proto_again;
+		break;
+	case FLOW_DISSECT_RET_OUT_GOOD:
+	case FLOW_DISSECT_RET_CONTINUE:
+		break;
+	case FLOW_DISSECT_RET_OUT_BAD:
+	default:
+		goto out_bad;
+	}
+
+out_good:
+	ret = true;
+
+out:
+	key_control->thoff = min_t(u16, nhoff, skb ? skb->len : hlen);
+	key_basic->n_proto = proto;
+	key_basic->ip_proto = ip_proto;
+
+	return ret;
+
+out_bad:
+	ret = false;
+	goto out;
+}
+EXPORT_SYMBOL(__skb_flow_dissect);
+
+static siphash_key_t hashrnd __read_mostly;
+static __always_inline void __flow_hash_secret_init(void)
+{
+	net_get_random_once(&hashrnd, sizeof(hashrnd));
+}
+
+static const void *flow_keys_hash_start(const struct flow_keys *flow)
+{
+	BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % SIPHASH_ALIGNMENT);
+	return &flow->FLOW_KEYS_HASH_START_FIELD;
+}
+
+static inline size_t flow_keys_hash_length(const struct flow_keys *flow)
+{
+	size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
+	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;
+	case FLOW_DISSECTOR_KEY_TIPC:
+		diff -= sizeof(flow->addrs.tipckey);
+		break;
+	}
+	return sizeof(*flow) - diff;
+}
+
+__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);
+	case FLOW_DISSECTOR_KEY_TIPC:
+		return flow->addrs.tipckey.key;
+	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;
+	}
+}
+
+static inline u32 __flow_hash_from_keys(struct flow_keys *keys,
+					const siphash_key_t *keyval)
+{
+	u32 hash;
+
+	__flow_hash_consistentify(keys);
+
+	hash = siphash(flow_keys_hash_start(keys),
+		       flow_keys_hash_length(keys), keyval);
+	if (!hash)
+		hash = 1;
+
+	return hash;
+}
+
+u32 flow_hash_from_keys(struct flow_keys *keys)
+{
+	__flow_hash_secret_init();
+	return __flow_hash_from_keys(keys, &hashrnd);
+}
+EXPORT_SYMBOL(flow_hash_from_keys);
+
+static inline u32 ___skb_get_hash(const struct sk_buff *skb,
+				  struct flow_keys *keys,
+				  const siphash_key_t *keyval)
+{
+	skb_flow_dissect_flow_keys(skb, keys,
+				   FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL);
+
+	return __flow_hash_from_keys(keys, keyval);
+}
+
+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));
+
+	data->n_proto = flow->basic.n_proto;
+	data->ip_proto = flow->basic.ip_proto;
+	data->ports = flow->ports.ports;
+	data->src = flow->addrs.v4addrs.src;
+	data->dst = flow->addrs.v4addrs.dst;
+}
+EXPORT_SYMBOL(make_flow_keys_digest);
+
+static struct flow_dissector flow_keys_dissector_symmetric __read_mostly;
+
+u32 __skb_get_hash_symmetric(const struct sk_buff *skb)
+{
+	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);
+
+/**
+ * __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
+ * 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
+ * if hash is a canonical 4-tuple hash over transport ports.
+ */
+void __skb_get_hash(struct sk_buff *skb)
+{
+	struct flow_keys keys;
+	u32 hash;
+
+	__flow_hash_secret_init();
+
+	hash = ___skb_get_hash(skb, &keys, &hashrnd);
+
+	__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
+}
+EXPORT_SYMBOL(__skb_get_hash);
+
+__u32 skb_get_hash_perturb(const struct sk_buff *skb,
+			   const siphash_key_t *perturb)
+{
+	struct flow_keys keys;
+
+	return ___skb_get_hash(skb, &keys, perturb);
+}
+EXPORT_SYMBOL(skb_get_hash_perturb);
+
+u32 __skb_get_poff(const struct sk_buff *skb, void *data,
+		   const struct flow_keys_basic *keys, int hlen)
+{
+	u32 poff = keys->control.thoff;
+
+	/* 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;
+
+	switch (keys->basic.ip_proto) {
+	case IPPROTO_TCP: {
+		/* access doff as u8 to avoid unaligned access */
+		const u8 *doff;
+		u8 _doff;
+
+		doff = __skb_header_pointer(skb, poff + 12, sizeof(_doff),
+					    data, hlen, &_doff);
+		if (!doff)
+			return poff;
+
+		poff += max_t(u32, sizeof(struct tcphdr), (*doff & 0xF0) >> 2);
+		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;
+}
+
+/**
+ * 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
+ * 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)
+{
+	struct flow_keys_basic keys;
+
+	if (!skb_flow_dissect_flow_keys_basic(skb, &keys, NULL, 0, 0, 0, 0))
+		return 0;
+
+	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
+}
+
+__u32 __get_hash_from_flowi6(const struct flowi6 *fl6, struct flow_keys *keys)
+{
+	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;
+	keys->tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
+	keys->basic.ip_proto = fl6->flowi6_proto;
+
+	return flow_hash_from_keys(keys);
+}
+EXPORT_SYMBOL(__get_hash_from_flowi6);
+
+static const struct flow_dissector_key flow_keys_dissector_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_TIPC,
+		.offset = offsetof(struct flow_keys, addrs.tipckey),
+	},
+	{
+		.key_id = FLOW_DISSECTOR_KEY_PORTS,
+		.offset = offsetof(struct flow_keys, ports),
+	},
+	{
+		.key_id = FLOW_DISSECTOR_KEY_VLAN,
+		.offset = offsetof(struct flow_keys, vlan),
+	},
+	{
+		.key_id = FLOW_DISSECTOR_KEY_FLOW_LABEL,
+		.offset = offsetof(struct flow_keys, tags),
+	},
+	{
+		.key_id = FLOW_DISSECTOR_KEY_GRE_KEYID,
+		.offset = offsetof(struct flow_keys, keyid),
+	},
+};
+
+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),
+	},
+};
+
+static const struct flow_dissector_key flow_keys_basic_dissector_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),
+	},
+};
+
+struct flow_dissector flow_keys_dissector __read_mostly;
+EXPORT_SYMBOL(flow_keys_dissector);
+
+struct flow_dissector flow_keys_basic_dissector __read_mostly;
+EXPORT_SYMBOL(flow_keys_basic_dissector);
+
+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));
+	skb_flow_dissector_init(&flow_keys_dissector_symmetric,
+				flow_keys_dissector_symmetric_keys,
+				ARRAY_SIZE(flow_keys_dissector_symmetric_keys));
+	skb_flow_dissector_init(&flow_keys_basic_dissector,
+				flow_keys_basic_dissector_keys,
+				ARRAY_SIZE(flow_keys_basic_dissector_keys));
+	return 0;
+}
+
+core_initcall(init_default_flow_dissectors);