[PATCH v2 6/9] ipv6: sr: add calls to verify and insert HMAC signatures

[David Lebrun]

This patch enables the verification of the HMAC signature for transiting
SR-enabled packets, and its insertion on encapsulated/injected SRH.

Signed-off-by: David Lebrun <david.leb...@uclouvain.be>
---
 net/ipv6/exthdrs.c       | 10 ++++++++++
 net/ipv6/seg6_iptunnel.c | 18 ++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index cf9f338..9b63932 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -48,6 +48,9 @@
 #include <net/xfrm.h>
 #endif
 #include <linux/seg6.h>
+#ifdef CONFIG_IPV6_SEG6_HMAC
+#include <net/seg6_hmac.h>
+#endif
 
 #include <linux/uaccess.h>
 
@@ -358,6 +361,13 @@ static int ipv6_srh_rcv(struct sk_buff *skb)
                return -1;
        }
 
+#ifdef CONFIG_IPV6_SEG6_HMAC
+       if (!seg6_hmac_validate_skb(skb)) {
+               kfree_skb(skb);
+               return -1;
+       }
+#endif
+
 looped_back:
        if (hdr->segments_left > 0) {
                if (hdr->nexthdr != NEXTHDR_IPV6 && hdr->segments_left == 1 &&
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c
index caae8ab..2c53991 100644
--- a/net/ipv6/seg6_iptunnel.c
+++ b/net/ipv6/seg6_iptunnel.c
@@ -126,6 +126,14 @@ static int seg6_do_srh_encap(struct sk_buff *skb, struct 
ipv6_sr_hdr *osrh)
        hdr->daddr = isrh->segments[isrh->first_segment];
        set_tun_src(net, skb->dev, &hdr->daddr, &hdr->saddr);
 
+#ifdef CONFIG_IPV6_SEG6_HMAC
+       if (sr_has_hmac(isrh)) {
+               err = seg6_push_hmac(net, &hdr->saddr, isrh);
+               if (unlikely(err))
+                       return err;
+       }
+#endif
+
        skb_postpush_rcsum(skb, hdr, tot_len);
 
        return 0;
@@ -167,6 +175,16 @@ static int seg6_do_srh_inline(struct sk_buff *skb, struct 
ipv6_sr_hdr *osrh)
        isrh->segments[0] = hdr->daddr;
        hdr->daddr = isrh->segments[isrh->first_segment];
 
+#ifdef CONFIG_IPV6_SEG6_HMAC
+       if (sr_has_hmac(isrh)) {
+               struct net *net = dev_net(skb_dst(skb)->dev);
+
+               err = seg6_push_hmac(net, &hdr->saddr, isrh);
+               if (unlikely(err))
+                       return err;
+       }
+#endif
+
        skb_postpush_rcsum(skb, hdr, sizeof(struct ipv6hdr) + hdrlen);
 
        return 0;
-- 
2.7.3