 8e690ffdbc
			
		
	
	
	8e690ffdbc
	
	
	
		
			
			net/core/flow_dissector.c: In function ‘__skb_flow_dissect’: net/core/flow_dissector.c:132: warning: ‘ip_proto’ may be used uninitialized in this function Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Tom Herbert <tom@herbertland.com> Signed-off-by: David S. Miller <davem@davemloft.net>
		
			
				
	
	
		
			758 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			758 lines
		
	
	
	
		
			19 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
| #include <linux/kernel.h>
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| #include <linux/skbuff.h>
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| #include <linux/export.h>
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| #include <linux/ip.h>
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| #include <linux/ipv6.h>
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| #include <linux/if_vlan.h>
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| #include <net/ip.h>
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| #include <net/ipv6.h>
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| #include <linux/igmp.h>
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| #include <linux/icmp.h>
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| #include <linux/sctp.h>
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| #include <linux/dccp.h>
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| #include <linux/if_tunnel.h>
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| #include <linux/if_pppox.h>
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| #include <linux/ppp_defs.h>
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| #include <linux/stddef.h>
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| #include <linux/if_ether.h>
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| #include <linux/mpls.h>
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| #include <net/flow_dissector.h>
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| #include <scsi/fc/fc_fcoe.h>
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| 
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| static bool skb_flow_dissector_uses_key(struct flow_dissector *flow_dissector,
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| 					enum flow_dissector_key_id key_id)
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| {
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| 	return flow_dissector->used_keys & (1 << key_id);
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| }
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| 
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| static void skb_flow_dissector_set_key(struct flow_dissector *flow_dissector,
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| 				       enum flow_dissector_key_id key_id)
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| {
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| 	flow_dissector->used_keys |= (1 << key_id);
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| }
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| 
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| static void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
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| 				       enum flow_dissector_key_id key_id,
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| 				       void *target_container)
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| {
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| 	return ((char *) target_container) + flow_dissector->offset[key_id];
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| }
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| 
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| void skb_flow_dissector_init(struct flow_dissector *flow_dissector,
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| 			     const struct flow_dissector_key *key,
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| 			     unsigned int key_count)
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| {
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| 	unsigned int i;
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| 
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| 	memset(flow_dissector, 0, sizeof(*flow_dissector));
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| 
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| 	for (i = 0; i < key_count; i++, key++) {
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| 		/* User should make sure that every key target offset is withing
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| 		 * boundaries of unsigned short.
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| 		 */
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| 		BUG_ON(key->offset > USHRT_MAX);
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| 		BUG_ON(skb_flow_dissector_uses_key(flow_dissector,
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| 						   key->key_id));
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| 
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| 		skb_flow_dissector_set_key(flow_dissector, key->key_id);
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| 		flow_dissector->offset[key->key_id] = key->offset;
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| 	}
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| 
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| 	/* Ensure that the dissector always includes control and basic key.
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| 	 * That way we are able to avoid handling lack of these in fast path.
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| 	 */
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| 	BUG_ON(!skb_flow_dissector_uses_key(flow_dissector,
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| 					    FLOW_DISSECTOR_KEY_CONTROL));
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| 	BUG_ON(!skb_flow_dissector_uses_key(flow_dissector,
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| 					    FLOW_DISSECTOR_KEY_BASIC));
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| }
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| EXPORT_SYMBOL(skb_flow_dissector_init);
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| 
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| /**
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|  * __skb_flow_get_ports - extract the upper layer ports and return them
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|  * @skb: sk_buff to extract the ports from
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|  * @thoff: transport header offset
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|  * @ip_proto: protocol for which to get port offset
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|  * @data: raw buffer pointer to the packet, if NULL use skb->data
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|  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
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|  *
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|  * The function will try to retrieve the ports at offset thoff + poff where poff
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|  * is the protocol port offset returned from proto_ports_offset
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|  */
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| __be32 __skb_flow_get_ports(const struct sk_buff *skb, int thoff, u8 ip_proto,
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| 			    void *data, int hlen)
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| {
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| 	int poff = proto_ports_offset(ip_proto);
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| 
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| 	if (!data) {
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| 		data = skb->data;
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| 		hlen = skb_headlen(skb);
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| 	}
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| 
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| 	if (poff >= 0) {
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| 		__be32 *ports, _ports;
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| 
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| 		ports = __skb_header_pointer(skb, thoff + poff,
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| 					     sizeof(_ports), data, hlen, &_ports);
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| 		if (ports)
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| 			return *ports;
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| 	}
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| 
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| 	return 0;
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| }
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| EXPORT_SYMBOL(__skb_flow_get_ports);
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| 
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| /**
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|  * __skb_flow_dissect - extract the flow_keys struct and return it
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|  * @skb: sk_buff to extract the flow from, can be NULL if the rest are specified
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|  * @flow_dissector: list of keys to dissect
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|  * @target_container: target structure to put dissected values into
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|  * @data: raw buffer pointer to the packet, if NULL use skb->data
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|  * @proto: protocol for which to get the flow, if @data is NULL use skb->protocol
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|  * @nhoff: network header offset, if @data is NULL use skb_network_offset(skb)
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|  * @hlen: packet header length, if @data is NULL use skb_headlen(skb)
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|  *
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|  * The function will try to retrieve individual keys into target specified
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|  * by flow_dissector from either the skbuff or a raw buffer specified by the
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|  * rest parameters.
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|  *
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|  * Caller must take care of zeroing target container memory.
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|  */
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| bool __skb_flow_dissect(const struct sk_buff *skb,
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| 			struct flow_dissector *flow_dissector,
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| 			void *target_container,
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| 			void *data, __be16 proto, int nhoff, int hlen)
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| {
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| 	struct flow_dissector_key_control *key_control;
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| 	struct flow_dissector_key_basic *key_basic;
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| 	struct flow_dissector_key_addrs *key_addrs;
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| 	struct flow_dissector_key_ports *key_ports;
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| 	struct flow_dissector_key_tags *key_tags;
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| 	struct flow_dissector_key_keyid *key_keyid;
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| 	u8 ip_proto = 0;
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| 
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| 	if (!data) {
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| 		data = skb->data;
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| 		proto = skb->protocol;
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| 		nhoff = skb_network_offset(skb);
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| 		hlen = skb_headlen(skb);
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| 	}
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| 
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| 	/* It is ensured by skb_flow_dissector_init() that control key will
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| 	 * be always present.
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| 	 */
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| 	key_control = skb_flow_dissector_target(flow_dissector,
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| 						FLOW_DISSECTOR_KEY_CONTROL,
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| 						target_container);
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| 
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| 	/* It is ensured by skb_flow_dissector_init() that basic key will
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| 	 * be always present.
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| 	 */
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| 	key_basic = skb_flow_dissector_target(flow_dissector,
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| 					      FLOW_DISSECTOR_KEY_BASIC,
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| 					      target_container);
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| 
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| 	if (skb_flow_dissector_uses_key(flow_dissector,
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| 					FLOW_DISSECTOR_KEY_ETH_ADDRS)) {
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| 		struct ethhdr *eth = eth_hdr(skb);
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| 		struct flow_dissector_key_eth_addrs *key_eth_addrs;
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| 
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| 		key_eth_addrs = skb_flow_dissector_target(flow_dissector,
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| 							  FLOW_DISSECTOR_KEY_ETH_ADDRS,
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| 							  target_container);
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| 		memcpy(key_eth_addrs, ð->h_dest, sizeof(*key_eth_addrs));
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| 	}
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| 
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| again:
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| 	switch (proto) {
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| 	case htons(ETH_P_IP): {
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| 		const struct iphdr *iph;
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| 		struct iphdr _iph;
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| ip:
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| 		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
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| 		if (!iph || iph->ihl < 5)
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| 			return false;
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| 		nhoff += iph->ihl * 4;
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| 
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| 		ip_proto = iph->protocol;
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| 		if (ip_is_fragment(iph))
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| 			ip_proto = 0;
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| 
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| 		if (!skb_flow_dissector_uses_key(flow_dissector,
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| 						 FLOW_DISSECTOR_KEY_IPV4_ADDRS))
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| 			break;
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| 
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| 		key_addrs = skb_flow_dissector_target(flow_dissector,
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| 			      FLOW_DISSECTOR_KEY_IPV4_ADDRS, target_container);
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| 		memcpy(&key_addrs->v4addrs, &iph->saddr,
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| 		       sizeof(key_addrs->v4addrs));
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| 		key_control->addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
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| 		break;
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| 	}
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| 	case htons(ETH_P_IPV6): {
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| 		const struct ipv6hdr *iph;
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| 		struct ipv6hdr _iph;
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| 		__be32 flow_label;
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| 
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| ipv6:
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| 		iph = __skb_header_pointer(skb, nhoff, sizeof(_iph), data, hlen, &_iph);
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| 		if (!iph)
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| 			return false;
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| 
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| 		ip_proto = iph->nexthdr;
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| 		nhoff += sizeof(struct ipv6hdr);
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| 
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| 		if (skb_flow_dissector_uses_key(flow_dissector,
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| 						FLOW_DISSECTOR_KEY_IPV6_ADDRS)) {
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| 			struct flow_dissector_key_ipv6_addrs *key_ipv6_addrs;
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| 
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| 			key_ipv6_addrs = skb_flow_dissector_target(flow_dissector,
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| 								   FLOW_DISSECTOR_KEY_IPV6_ADDRS,
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| 								   target_container);
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| 
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| 			memcpy(key_ipv6_addrs, &iph->saddr, sizeof(*key_ipv6_addrs));
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| 			key_control->addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
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| 		}
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| 
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| 		flow_label = ip6_flowlabel(iph);
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| 		if (flow_label) {
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| 			if (skb_flow_dissector_uses_key(flow_dissector,
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| 				FLOW_DISSECTOR_KEY_FLOW_LABEL)) {
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| 				key_tags = skb_flow_dissector_target(flow_dissector,
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| 								     FLOW_DISSECTOR_KEY_FLOW_LABEL,
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| 								     target_container);
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| 				key_tags->flow_label = ntohl(flow_label);
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| 			}
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| 		}
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| 
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| 		break;
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| 	}
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| 	case htons(ETH_P_8021AD):
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| 	case htons(ETH_P_8021Q): {
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| 		const struct vlan_hdr *vlan;
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| 		struct vlan_hdr _vlan;
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| 
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| 		vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan), data, hlen, &_vlan);
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| 		if (!vlan)
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| 			return false;
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| 
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| 		if (skb_flow_dissector_uses_key(flow_dissector,
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| 						FLOW_DISSECTOR_KEY_VLANID)) {
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| 			key_tags = skb_flow_dissector_target(flow_dissector,
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| 							     FLOW_DISSECTOR_KEY_VLANID,
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| 							     target_container);
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| 
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| 			key_tags->vlan_id = skb_vlan_tag_get_id(skb);
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| 		}
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| 
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| 		proto = vlan->h_vlan_encapsulated_proto;
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| 		nhoff += sizeof(*vlan);
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| 		goto again;
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| 	}
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| 	case htons(ETH_P_PPP_SES): {
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| 		struct {
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| 			struct pppoe_hdr hdr;
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| 			__be16 proto;
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| 		} *hdr, _hdr;
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| 		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
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| 		if (!hdr)
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| 			return false;
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| 		proto = hdr->proto;
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| 		nhoff += PPPOE_SES_HLEN;
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| 		switch (proto) {
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| 		case htons(PPP_IP):
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| 			goto ip;
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| 		case htons(PPP_IPV6):
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| 			goto ipv6;
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| 		default:
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| 			return false;
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| 		}
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| 	}
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| 	case htons(ETH_P_TIPC): {
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| 		struct {
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| 			__be32 pre[3];
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| 			__be32 srcnode;
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| 		} *hdr, _hdr;
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| 		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
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| 		if (!hdr)
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| 			return false;
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| 		key_basic->n_proto = proto;
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| 		key_control->thoff = (u16)nhoff;
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| 
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| 		if (skb_flow_dissector_uses_key(flow_dissector,
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| 						FLOW_DISSECTOR_KEY_TIPC_ADDRS)) {
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| 			key_addrs = skb_flow_dissector_target(flow_dissector,
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| 							      FLOW_DISSECTOR_KEY_TIPC_ADDRS,
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| 							      target_container);
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| 			key_addrs->tipcaddrs.srcnode = hdr->srcnode;
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| 			key_control->addr_type = FLOW_DISSECTOR_KEY_TIPC_ADDRS;
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| 		}
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| 		return true;
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| 	}
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| 
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| 	case htons(ETH_P_MPLS_UC):
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| 	case htons(ETH_P_MPLS_MC): {
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| 		struct mpls_label *hdr, _hdr[2];
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| mpls:
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| 		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data,
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| 					   hlen, &_hdr);
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| 		if (!hdr)
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| 			return false;
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| 
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| 		if ((ntohl(hdr[0].entry) & MPLS_LS_LABEL_MASK) >>
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| 		     MPLS_LS_LABEL_SHIFT == MPLS_LABEL_ENTROPY) {
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| 			if (skb_flow_dissector_uses_key(flow_dissector,
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| 							FLOW_DISSECTOR_KEY_MPLS_ENTROPY)) {
 | |
| 				key_keyid = skb_flow_dissector_target(flow_dissector,
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| 								      FLOW_DISSECTOR_KEY_MPLS_ENTROPY,
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| 								      target_container);
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| 				key_keyid->keyid = hdr[1].entry &
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| 					htonl(MPLS_LS_LABEL_MASK);
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| 			}
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| 
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| 			key_basic->n_proto = proto;
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| 			key_basic->ip_proto = ip_proto;
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| 			key_control->thoff = (u16)nhoff;
 | |
| 
 | |
| 			return true;
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| 		}
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| 
 | |
| 		return true;
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| 	}
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| 
 | |
| 	case htons(ETH_P_FCOE):
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| 		key_control->thoff = (u16)(nhoff + FCOE_HEADER_LEN);
 | |
| 		/* fall through */
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| 	default:
 | |
| 		return false;
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| 	}
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| 
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| ip_proto_again:
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| 	switch (ip_proto) {
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| 	case IPPROTO_GRE: {
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| 		struct gre_hdr {
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| 			__be16 flags;
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| 			__be16 proto;
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| 		} *hdr, _hdr;
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| 
 | |
| 		hdr = __skb_header_pointer(skb, nhoff, sizeof(_hdr), data, hlen, &_hdr);
 | |
| 		if (!hdr)
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| 			return false;
 | |
| 		/*
 | |
| 		 * Only look inside GRE if version zero and no
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| 		 * routing
 | |
| 		 */
 | |
| 		if (hdr->flags & (GRE_VERSION | GRE_ROUTING))
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| 			break;
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| 
 | |
| 		proto = hdr->proto;
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| 		nhoff += 4;
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| 		if (hdr->flags & GRE_CSUM)
 | |
| 			nhoff += 4;
 | |
| 		if (hdr->flags & GRE_KEY) {
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| 			const __be32 *keyid;
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| 			__be32 _keyid;
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| 
 | |
| 			keyid = __skb_header_pointer(skb, nhoff, sizeof(_keyid),
 | |
| 						     data, hlen, &_keyid);
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| 
 | |
| 			if (!keyid)
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| 				return false;
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| 
 | |
| 			if (skb_flow_dissector_uses_key(flow_dissector,
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| 							FLOW_DISSECTOR_KEY_GRE_KEYID)) {
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| 				key_keyid = skb_flow_dissector_target(flow_dissector,
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| 								      FLOW_DISSECTOR_KEY_GRE_KEYID,
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| 								      target_container);
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| 				key_keyid->keyid = *keyid;
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| 			}
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| 			nhoff += 4;
 | |
| 		}
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| 		if (hdr->flags & GRE_SEQ)
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| 			nhoff += 4;
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| 		if (proto == htons(ETH_P_TEB)) {
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| 			const struct ethhdr *eth;
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| 			struct ethhdr _eth;
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| 
 | |
| 			eth = __skb_header_pointer(skb, nhoff,
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| 						   sizeof(_eth),
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| 						   data, hlen, &_eth);
 | |
| 			if (!eth)
 | |
| 				return false;
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| 			proto = eth->h_proto;
 | |
| 			nhoff += sizeof(*eth);
 | |
| 		}
 | |
| 		goto again;
 | |
| 	}
 | |
| 	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)
 | |
| 			return false;
 | |
| 
 | |
| 		ip_proto = opthdr[0];
 | |
| 		nhoff += (opthdr[1] + 1) << 3;
 | |
| 
 | |
| 		goto ip_proto_again;
 | |
| 	}
 | |
| 	case IPPROTO_IPIP:
 | |
| 		proto = htons(ETH_P_IP);
 | |
| 		goto ip;
 | |
| 	case IPPROTO_IPV6:
 | |
| 		proto = htons(ETH_P_IPV6);
 | |
| 		goto ipv6;
 | |
| 	case IPPROTO_MPLS:
 | |
| 		proto = htons(ETH_P_MPLS_UC);
 | |
| 		goto mpls;
 | |
| 	default:
 | |
| 		break;
 | |
| 	}
 | |
| 
 | |
| 	key_basic->n_proto = proto;
 | |
| 	key_basic->ip_proto = ip_proto;
 | |
| 	key_control->thoff = (u16)nhoff;
 | |
| 
 | |
| 	if (skb_flow_dissector_uses_key(flow_dissector,
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| 					FLOW_DISSECTOR_KEY_PORTS)) {
 | |
| 		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);
 | |
| 	}
 | |
| 
 | |
| 	return true;
 | |
| }
 | |
| EXPORT_SYMBOL(__skb_flow_dissect);
 | |
| 
 | |
| static u32 hashrnd __read_mostly;
 | |
| static __always_inline void __flow_hash_secret_init(void)
 | |
| {
 | |
| 	net_get_random_once(&hashrnd, sizeof(hashrnd));
 | |
| }
 | |
| 
 | |
| static __always_inline u32 __flow_hash_words(u32 *words, u32 length, u32 keyval)
 | |
| {
 | |
| 	return jhash2(words, length, keyval);
 | |
| }
 | |
| 
 | |
| static inline void *flow_keys_hash_start(struct flow_keys *flow)
 | |
| {
 | |
| 	BUILD_BUG_ON(FLOW_KEYS_HASH_OFFSET % sizeof(u32));
 | |
| 	return (void *)flow + FLOW_KEYS_HASH_OFFSET;
 | |
| }
 | |
| 
 | |
| static inline size_t flow_keys_hash_length(struct flow_keys *flow)
 | |
| {
 | |
| 	size_t diff = FLOW_KEYS_HASH_OFFSET + sizeof(flow->addrs);
 | |
| 	BUILD_BUG_ON((sizeof(*flow) - FLOW_KEYS_HASH_OFFSET) % sizeof(u32));
 | |
| 	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_ADDRS:
 | |
| 		diff -= sizeof(flow->addrs.tipcaddrs);
 | |
| 		break;
 | |
| 	}
 | |
| 	return (sizeof(*flow) - diff) / sizeof(u32);
 | |
| }
 | |
| 
 | |
| __be32 flow_get_u32_src(const struct flow_keys *flow)
 | |
| {
 | |
| 	switch (flow->control.addr_type) {
 | |
| 	case FLOW_DISSECTOR_KEY_IPV4_ADDRS:
 | |
| 		return flow->addrs.v4addrs.src;
 | |
| 	case FLOW_DISSECTOR_KEY_IPV6_ADDRS:
 | |
| 		return (__force __be32)ipv6_addr_hash(
 | |
| 			&flow->addrs.v6addrs.src);
 | |
| 	case FLOW_DISSECTOR_KEY_TIPC_ADDRS:
 | |
| 		return flow->addrs.tipcaddrs.srcnode;
 | |
| 	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, u32 keyval)
 | |
| {
 | |
| 	u32 hash;
 | |
| 
 | |
| 	__flow_hash_consistentify(keys);
 | |
| 
 | |
| 	hash = __flow_hash_words((u32 *)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, u32 keyval)
 | |
| {
 | |
| 	if (!skb_flow_dissect_flow_keys(skb, keys))
 | |
| 		return 0;
 | |
| 
 | |
| 	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);
 | |
| 
 | |
| /**
 | |
|  * __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);
 | |
| 	if (!hash)
 | |
| 		return;
 | |
| 	if (keys.ports.ports)
 | |
| 		skb->l4_hash = 1;
 | |
| 	skb->sw_hash = 1;
 | |
| 	skb->hash = hash;
 | |
| }
 | |
| EXPORT_SYMBOL(__skb_get_hash);
 | |
| 
 | |
| __u32 skb_get_hash_perturb(const struct sk_buff *skb, u32 perturb)
 | |
| {
 | |
| 	struct flow_keys keys;
 | |
| 
 | |
| 	return ___skb_get_hash(skb, &keys, perturb);
 | |
| }
 | |
| EXPORT_SYMBOL(skb_get_hash_perturb);
 | |
| 
 | |
| u32 __skb_get_poff(const struct sk_buff *skb, void *data,
 | |
| 		   const struct flow_keys *keys, int hlen)
 | |
| {
 | |
| 	u32 poff = keys->control.thoff;
 | |
| 
 | |
| 	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 keys;
 | |
| 
 | |
| 	if (!skb_flow_dissect_flow_keys(skb, &keys))
 | |
| 		return 0;
 | |
| 
 | |
| 	return __skb_get_poff(skb, skb->data, &keys, skb_headlen(skb));
 | |
| }
 | |
| 
 | |
| 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_ADDRS,
 | |
| 		.offset = offsetof(struct flow_keys, addrs.tipcaddrs),
 | |
| 	},
 | |
| 	{
 | |
| 		.key_id = FLOW_DISSECTOR_KEY_PORTS,
 | |
| 		.offset = offsetof(struct flow_keys, ports),
 | |
| 	},
 | |
| 	{
 | |
| 		.key_id = FLOW_DISSECTOR_KEY_VLANID,
 | |
| 		.offset = offsetof(struct flow_keys, tags),
 | |
| 	},
 | |
| 	{
 | |
| 		.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_buf_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_buf_dissector __read_mostly;
 | |
| 
 | |
| 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_buf_dissector,
 | |
| 				flow_keys_buf_dissector_keys,
 | |
| 				ARRAY_SIZE(flow_keys_buf_dissector_keys));
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| late_initcall_sync(init_default_flow_dissectors);
 |