From c30da497893718abc6cec4f1d34d35875200edee Mon Sep 17 00:00:00 2001 From: Simon Horman Date: Sat, 29 Aug 2015 09:02:21 +0900 Subject: [PATCH] openvswitch: retain parsed IPv6 header fields in flow on error skipping extension headers When an error occurs skipping IPv6 extension headers retain the already parsed IP protocol and IPv6 addresses in the flow. Also assume that the packet is not a fragment in the absence of information to the contrary; that is always use the frag_off value set by ipv6_skip_exthdr(). This allows matching on the IP protocol and IPv6 addresses of packets with malformed extension headers. Signed-off-by: Simon Horman Signed-off-by: David S. Miller --- net/openvswitch/flow.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 9760dc43bdb9..9db87331e211 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -272,8 +272,6 @@ static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) key->ipv6.addr.dst = nh->daddr; payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off); - if (unlikely(payload_ofs < 0)) - return -EINVAL; if (frag_off) { if (frag_off & htons(~0x7)) @@ -284,6 +282,13 @@ static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key) key->ip.frag = OVS_FRAG_TYPE_NONE; } + /* Delayed handling of error in ipv6_skip_exthdr() as it + * always sets frag_off to a valid value which may be + * used to set key->ip.frag above. + */ + if (unlikely(payload_ofs < 0)) + return -EPROTO; + nh_len = payload_ofs - nh_ofs; skb_set_transport_header(skb, nh_ofs + nh_len); key->ip.proto = nexthdr; @@ -623,12 +628,16 @@ static int key_extract(struct sk_buff *skb, struct sw_flow_key *key) nh_len = parse_ipv6hdr(skb, key); if (unlikely(nh_len < 0)) { - memset(&key->ip, 0, sizeof(key->ip)); - memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr)); - if (nh_len == -EINVAL) { + switch (nh_len) { + case -EINVAL: + memset(&key->ip, 0, sizeof(key->ip)); + memset(&key->ipv6.addr, 0, sizeof(key->ipv6.addr)); + /* fall-through */ + case -EPROTO: skb->transport_header = skb->network_header; error = 0; - } else { + break; + default: error = nh_len; } return error; -- 2.20.1