Merge branch 'seg6-next'

Julien Massonneau says:

====================
SRv6: SRH processing improvements

Add support for IPv4 decapsulation in ipv6_srh_rcv() and
ignore routing header with segments left equal to 0 for
seg6local actions that doesn't perfom decapsulation.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6.h

@@ -30,6 +30,7 @@
  */
 
 #define NEXTHDR_HOP		0	/* Hop-by-hop option header. */
+#define NEXTHDR_IPV4		4	/* IPv4 in IPv6 */
 #define NEXTHDR_TCP		6	/* TCP segment. */
 #define NEXTHDR_UDP		17	/* UDP message. */
 #define NEXTHDR_IPV6		41	/* IPv6 in IPv6 */

net/ipv6/exthdrs.c

@@ -381,7 +381,7 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
 
 looped_back:
 	if (hdr->segments_left == 0) {
-		if (hdr->nexthdr == NEXTHDR_IPV6) {
+		if (hdr->nexthdr == NEXTHDR_IPV6 || hdr->nexthdr == NEXTHDR_IPV4) {
 			int offset = (hdr->hdrlen + 1) << 3;
 
 			skb_postpull_rcsum(skb, skb_network_header(skb),
@@ -397,7 +397,8 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
 			skb_reset_network_header(skb);
 			skb_reset_transport_header(skb);
 			skb->encapsulation = 0;
-
+			if (hdr->nexthdr == NEXTHDR_IPV4)
+				skb->protocol = htons(ETH_P_IP);
 			__skb_tunnel_rx(skb, skb->dev, net);
 
 			netif_rx(skb);

net/ipv6/seg6_local.c

@@ -119,12 +119,12 @@ static struct seg6_local_lwt *seg6_local_lwtunnel(struct lwtunnel_state *lwt)
 	return (struct seg6_local_lwt *)lwt->data;
 }
 
-static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb)
+static struct ipv6_sr_hdr *get_srh(struct sk_buff *skb, int flags)
 {
 	struct ipv6_sr_hdr *srh;
 	int len, srhoff = 0;
 
-	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, NULL) < 0)
+	if (ipv6_find_hdr(skb, &srhoff, IPPROTO_ROUTING, NULL, &flags) < 0)
 		return NULL;
 
 	if (!pskb_may_pull(skb, srhoff + sizeof(*srh)))
@@ -152,13 +152,10 @@ static struct ipv6_sr_hdr *get_and_validate_srh(struct sk_buff *skb)
 {
 	struct ipv6_sr_hdr *srh;
 
-	srh = get_srh(skb);
+	srh = get_srh(skb, IP6_FH_F_SKIP_RH);
 	if (!srh)
 		return NULL;
 
-	if (srh->segments_left == 0)
-		return NULL;
-
 #ifdef CONFIG_IPV6_SEG6_HMAC
 	if (!seg6_hmac_validate_skb(skb))
 		return NULL;
@@ -172,7 +169,7 @@ static bool decap_and_validate(struct sk_buff *skb, int proto)
 	struct ipv6_sr_hdr *srh;
 	unsigned int off = 0;
 
-	srh = get_srh(skb);
+	srh = get_srh(skb, 0);
 	if (srh && srh->segments_left > 0)
 		return false;