ndp: Use tap_icmp6_send() helper

We send ICMPv6 packets to the guest from both icmp.c and from ndp.c.  The
case in ndp() manually constructs L2 and IPv6 headers, unlike the version
in icmp.c which uses the tap_icmp6_send() helper from tap.c  Now that we've
broaded the parameters of tap_icmp6_send() we can use it in ndp() as well
saving some duplicated logic.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

1 files changed, 4 insertions, 17 deletions

diff --git a/ndp.c b/ndp.c
index f96b4b7..80e1f19 100644
--- a/ndp.c
+++ b/ndp.c
@@ -47,6 +47,7 @@
  */
 int ndp(struct ctx *c, const struct icmp6hdr *ih, const struct in6_addr *saddr)
 {
+	const struct in6_addr *rsaddr; /* src addr for reply */
 	char buf[BUFSIZ] = { 0 };
 	struct ipv6hdr *ip6hr;
 	struct icmp6hdr *ihr;
@@ -180,26 +181,12 @@ dns_done:
 	else
 		c->ip6.addr_seen = *saddr;
 
-	ip6hr->daddr = *saddr;
 	if (IN6_IS_ADDR_LINKLOCAL(&c->ip6.gw))
-		ip6hr->saddr = c->ip6.gw;
+		rsaddr = &c->ip6.gw;
 	else
-		ip6hr->saddr = c->ip6.addr_ll;
+		rsaddr = &c->ip6.addr_ll;
 
-	ip6hr->payload_len = htons(sizeof(*ihr) + len);
-	csum_icmp6(ihr, &ip6hr->saddr, &ip6hr->daddr, ihr + 1, len);
-
-	ip6hr->version = 6;
-	ip6hr->nexthdr = IPPROTO_ICMPV6;
-	ip6hr->hop_limit = 255;
-
-	len += sizeof(*ehr) + sizeof(*ip6hr) + sizeof(*ihr);
-	memcpy(ehr->h_dest, c->mac_guest, ETH_ALEN);
-	memcpy(ehr->h_source, c->mac, ETH_ALEN);
-	ehr->h_proto = htons(ETH_P_IPV6);
-
-	if (tap_send(c, ehr, len) < 0)
-		perror("NDP: send");
+	tap_icmp6_send(c, rsaddr, saddr, ihr, len + sizeof(*ihr));
 
 	return 1;
 }