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Commit 32d99d0b authored by David Lebrun's avatar David Lebrun Committed by David S. Miller
Browse files

ipv6: sr: add support for ip4ip6 encapsulation 



This patch enables the SRv6 encapsulation mode to carry an IPv4 payload.
All the infrastructure was already present, I just had to add a parameter
to seg6_do_srh_encap() to specify the inner packet protocol, and perform
some additional checks.

Usage example:
ip route add 1.2.3.4 encap seg6 mode encap segs fc00::1,fc00::2 dev eth0

Signed-off-by: default avatarDavid Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 3fd87127

include/net/seg6.h

+2 −1
Original line number Diff line number Diff line
@@ -60,7 +60,8 @@ extern int seg6_local_init(void); 
extern void seg6_local_exit(void);



extern bool seg6_validate_srh(struct ipv6_sr_hdr *srh, int len);

extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);

extern int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh,

			     int proto);

extern int seg6_do_srh_inline(struct sk_buff *skb, struct ipv6_sr_hdr *osrh);



#endif

net/ipv6/seg6_iptunnel.c

+37 −10
Original line number Diff line number Diff line
@@ -91,7 +91,7 @@ static void set_tun_src(struct net *net, struct net_device *dev, 
}



/* encapsulate an IPv6 packet within an outer IPv6 header with a given SRH */

int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh)

int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh, int proto)

{

	struct net *net = dev_net(skb_dst(skb)->dev);

	struct ipv6hdr *hdr, *inner_hdr;
@@ -116,15 +116,22 @@ int seg6_do_srh_encap(struct sk_buff *skb, struct ipv6_sr_hdr *osrh) 
	 * hlim will be decremented in ip6_forward() afterwards and

	 * decapsulation will overwrite inner hlim with outer hlim

	 */



	if (skb->protocol == htons(ETH_P_IPV6)) {

		ip6_flow_hdr(hdr, ip6_tclass(ip6_flowinfo(inner_hdr)),

			     ip6_flowlabel(inner_hdr));

		hdr->hop_limit = inner_hdr->hop_limit;

	} else {

		ip6_flow_hdr(hdr, 0, 0);

		hdr->hop_limit = ip6_dst_hoplimit(skb_dst(skb));

	}



	hdr->nexthdr = NEXTHDR_ROUTING;



	isrh = (void *)hdr + sizeof(*hdr);

	memcpy(isrh, osrh, hdrlen);



	isrh->nexthdr = NEXTHDR_IPV6;

	isrh->nexthdr = proto;



	hdr->daddr = isrh->segments[isrh->first_segment];

	set_tun_src(net, skb->dev, &hdr->daddr, &hdr->saddr);
@@ -199,7 +206,7 @@ static int seg6_do_srh(struct sk_buff *skb) 
{

	struct dst_entry *dst = skb_dst(skb);

	struct seg6_iptunnel_encap *tinfo;

	int err = 0;

	int proto, err = 0;



	tinfo = seg6_encap_lwtunnel(dst->lwtstate);
@@ -210,17 +217,31 @@ static int seg6_do_srh(struct sk_buff *skb) 


	switch (tinfo->mode) {

	case SEG6_IPTUN_MODE_INLINE:

		if (skb->protocol != htons(ETH_P_IPV6))

			return -EINVAL;



		err = seg6_do_srh_inline(skb, tinfo->srh);

		if (err)

			return err;



		skb_reset_inner_headers(skb);

		break;

	case SEG6_IPTUN_MODE_ENCAP:

		err = seg6_do_srh_encap(skb, tinfo->srh);

		break;

	}

		if (skb->protocol == htons(ETH_P_IPV6))

			proto = IPPROTO_IPV6;

		else if (skb->protocol == htons(ETH_P_IP))

			proto = IPPROTO_IPIP;

		else

			return -EINVAL;



		err = seg6_do_srh_encap(skb, tinfo->srh, proto);

		if (err)

			return err;



		skb->protocol = htons(ETH_P_IPV6);

		break;

	}



	ipv6_hdr(skb)->payload_len = htons(skb->len - sizeof(struct ipv6hdr));

	skb_set_transport_header(skb, sizeof(struct ipv6hdr));
@@ -334,6 +355,9 @@ static int seg6_build_state(struct nlattr *nla, 
	struct seg6_lwt *slwt;

	int err;



	if (family != AF_INET && family != AF_INET6)

		return -EINVAL;



	err = nla_parse_nested(tb, SEG6_IPTUNNEL_MAX, nla,

			       seg6_iptunnel_policy, extack);
@@ -356,6 +380,9 @@ static int seg6_build_state(struct nlattr *nla, 


	switch (tuninfo->mode) {

	case SEG6_IPTUN_MODE_INLINE:

		if (family != AF_INET6)

			return -EINVAL;



		break;

	case SEG6_IPTUN_MODE_ENCAP:

		break;

net/ipv6/seg6_local.c

+1 −1
Original line number Diff line number Diff line
@@ -290,7 +290,7 @@ static int input_action_end_b6_encap(struct sk_buff *skb, 
	skb_reset_inner_headers(skb);

	skb->encapsulation = 1;



	err = seg6_do_srh_encap(skb, slwt->srh);

	err = seg6_do_srh_encap(skb, slwt->srh, IPPROTO_IPV6);

	if (err)

		goto drop;