Support translating ICMP errors.
When receiving ICMPv6 messages from IPv6-only nodes, use
255.0.0.<ttl> as a fake IPv4 source address. It's better than
nothing.
Bug: 8276725
Change-Id: Iae93f75764cb9cd875af9bb5f1862a0dce2c2fa7
diff --git a/clatd.c b/clatd.c
index a914f02..063026d 100644
--- a/clatd.c
+++ b/clatd.c
@@ -317,12 +317,16 @@
struct tun_pi tun_targ;
char iphdr[sizeof(struct ip6_hdr)];
char transporthdr[MAX_TCP_HDR];
+ char icmp_iphdr[sizeof(struct ip6_hdr)];
+ char icmp_transporthdr[MAX_TCP_HDR];
// iovec of the packets we'll send. This gets passed down to the translation functions.
clat_packet out = {
{ &tun_targ, sizeof(tun_targ) }, // Tunnel header.
{ iphdr, 0 }, // IP header.
{ transporthdr, 0 }, // Transport layer header.
+ { icmp_iphdr, 0 }, // ICMP error inner IP header.
+ { icmp_transporthdr, 0 }, // ICMP error transport layer header.
{ NULL, 0 }, // Payload. No buffer, it's a pointer to the original payload.
};