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| author | dhartmei <dhartmei@FreeBSD.org> | 2004-12-05 12:15:43 +0000 |
|---|---|---|
| committer | dhartmei <dhartmei@FreeBSD.org> | 2004-12-05 12:15:43 +0000 |
| commit | de7cd2f92a8a77a8466253d93705bf9b492b88c2 (patch) | |
| tree | 48682094be636526bcf16fa40bcec268d1158e77 /sys/contrib | |
| parent | 68bef2dca52d3201b5d429a1ae55e7936877c49a (diff) | |
| download | FreeBSD-src-de7cd2f92a8a77a8466253d93705bf9b492b88c2.zip FreeBSD-src-de7cd2f92a8a77a8466253d93705bf9b492b88c2.tar.gz | |
IPv6 packets can contain headers (like options) before the TCP/UDP/ICMP6
header. pf finds the first TCP/UDP/ICMP6 header to filter by traversing
the header chain. In the case where headers are skipped, the protocol
checksum verification used the wrong length (included the skipped headers),
leading to incorrectly mismatching checksums. Such IPv6 packets with
headers were silently dropped.
Discovered by: Bernhard Schmidt
MFC after: 1 week
Diffstat (limited to 'sys/contrib')
| -rw-r--r-- | sys/contrib/pf/net/pf.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/sys/contrib/pf/net/pf.c b/sys/contrib/pf/net/pf.c index d29be54..99958c7 100644 --- a/sys/contrib/pf/net/pf.c +++ b/sys/contrib/pf/net/pf.c @@ -6334,7 +6334,8 @@ pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0) goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, - ntohs(h->ip6_plen), IPPROTO_TCP, AF_INET6)) { + ntohs(h->ip6_plen) - (off - sizeof(struct ip6_hdr)), + IPPROTO_TCP, AF_INET6)) { action = PF_DROP; goto done; } @@ -6372,7 +6373,8 @@ pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0) goto done; } if (dir == PF_IN && uh.uh_sum && pf_check_proto_cksum(m, - off, ntohs(h->ip6_plen), IPPROTO_UDP, AF_INET6)) { + off, ntohs(h->ip6_plen) - (off - sizeof(struct ip6_hdr)), + IPPROTO_UDP, AF_INET6)) { action = PF_DROP; goto done; } @@ -6411,7 +6413,8 @@ pf_test6(int dir, struct ifnet *ifp, struct mbuf **m0) goto done; } if (dir == PF_IN && pf_check_proto_cksum(m, off, - ntohs(h->ip6_plen), IPPROTO_ICMPV6, AF_INET6)) { + ntohs(h->ip6_plen) - (off - sizeof(struct ip6_hdr)), + IPPROTO_ICMPV6, AF_INET6)) { action = PF_DROP; goto done; } |
