This corrects issues in IPv6 header handling that sometimes resulted
in an endless loop.
Signed-off-by: Etan Kissling <etan_kissling@xxxxxxxxx>
---
v2: Updated loop condition to be consistent with the implementation
ipv6_skip_exthdr() in the Linux kernel.
v3: Re-allow fetching extension headers using 'target' parameter.
src/extra/ipv6.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
diff --git a/src/extra/ipv6.c b/src/extra/ipv6.c
index 42c5e25..88cd77b 100644
--- a/src/extra/ipv6.c
+++ b/src/extra/ipv6.c
@@ -67,10 +67,19 @@ int nfq_ip6_set_transport_header(struct pkt_buff *pktb, struct ip6_hdr *ip6h,
uint8_t nexthdr = ip6h->ip6_nxt;
uint8_t *cur = (uint8_t *)ip6h + sizeof(struct ip6_hdr);
- while (nexthdr != target) {
+ while (nexthdr == IPPROTO_HOPOPTS ||
+ nexthdr == IPPROTO_ROUTING ||
+ nexthdr == IPPROTO_FRAGMENT ||
+ nexthdr == IPPROTO_AH ||
+ nexthdr == IPPROTO_NONE ||
+ nexthdr == IPPROTO_DSTOPTS) {
struct ip6_ext *ip6_ext;
uint32_t hdrlen;
+ /* Extension header was requested, we're done. */
+ if (nexthdr == target)
+ break;
+
/* No more extensions, we're done. */
if (nexthdr == IPPROTO_NONE) {
cur = NULL;
@@ -107,11 +116,13 @@ int nfq_ip6_set_transport_header(struct pkt_buff *pktb, struct ip6_hdr *ip6h,
} else if (nexthdr == IPPROTO_AH)
hdrlen = (ip6_ext->ip6e_len + 2) << 2;
else
- hdrlen = ip6_ext->ip6e_len;
+ hdrlen = (ip6_ext->ip6e_len + 1) << 3;
nexthdr = ip6_ext->ip6e_nxt;
cur += hdrlen;
}
+ if (nexthdr != target)
+ cur = NULL;
pktb->transport_header = cur;
return cur ? 1 : 0;
}
--
2.21.1 (Apple Git-122.3)
