aboutgitcodebugslistschat
diff options
context:
space:
mode:
authorStefano Brivio <sbrivio@redhat.com>2021-05-21 11:14:52 +0200
committerStefano Brivio <sbrivio@redhat.com>2021-05-21 11:14:52 +0200
commit5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9 (patch)
tree661eaa9749d8588ab1f9dbf5c890e598a3adc7b2
parentad4a85c86056dbab773ba3e2823b51cf1d128245 (diff)
downloadpasst-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar.gz
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar.bz2
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar.lz
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar.xz
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.tar.zst
passt-5fd6db7751c4fd20a4a2415fdda8b09b5ce524f9.zip
ndp: Always answer neighbour solicitations with the requested target address
The guest might try to resolve hosts other than the main host namespace (i.e. the gateway) -- just recycle the target address from the request and resolve it to the MAC address of the gateway. Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
-rw-r--r--ndp.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/ndp.c b/ndp.c
index 40cfe93..1d2a2d3 100644
--- a/ndp.c
+++ b/ndp.c
@@ -48,6 +48,9 @@ int ndp(struct ctx *c, struct ethhdr *eh, size_t len)
char buf[BUFSIZ] = { 0 };
uint8_t proto, *p;
+ if (len < sizeof(*ehr) + sizeof(*ip6h) + sizeof(ih))
+ return 0;
+
ih = (struct icmp6hdr *)ipv6_l4hdr(ip6h, &proto);
if (!ih)
return -1;
@@ -61,6 +64,10 @@ int ndp(struct ctx *c, struct ethhdr *eh, size_t len)
ihr = (struct icmp6hdr *)(ip6hr + 1);
if (ih->icmp6_type == NS) {
+ if (len < sizeof(*ehr) + sizeof(*ip6h) + sizeof(ih) +
+ sizeof(struct in6_addr))
+ return -1;
+
info("NDP: received NS, sending NA");
ihr->icmp6_type = NA;
ihr->icmp6_code = 0;
@@ -69,10 +76,10 @@ int ndp(struct ctx *c, struct ethhdr *eh, size_t len)
ihr->icmp6_override = 1;
p = (unsigned char *)(ihr + 1);
- memcpy(p, &c->gw6, sizeof(c->gw6)); /* target address */
+ memcpy(p, ih + 1, sizeof(struct in6_addr)); /* target address */
p += 16;
- *p++ = 2; /* target ll */
- *p++ = 1; /* length */
+ *p++ = 2; /* target ll */
+ *p++ = 1; /* length */
memcpy(p, c->mac, ETH_ALEN);
p += 6;
} else if (ih->icmp6_type == RS) {