[ovs-dev] [PATCH/RFC] openvswitch: Retain parsed IPv6 header fields in flow on error skipping extension headers
Simon Horman
simon.horman at netronome.com
Fri Aug 14 01:30:13 UTC 2015
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 <simon.horman at netronome.com>
---
* Some consideration should be given to unwanted side effects of this patch
as it affects the handling of malformed packets.
Signed-off-by: Simon Horman <simon.horman at netronome.com>
---
net/openvswitch/flow.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 8db22ef73626..3c5336c5d4ea 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -271,8 +271,6 @@ 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))
@@ -283,6 +281,13 @@ 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 -EINVAL;
+
nh_len = payload_ofs - nh_ofs;
skb_set_transport_header(skb, nh_ofs + nh_len);
key->ip.proto = nexthdr;
@@ -622,8 +627,6 @@ 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) {
skb->transport_header = skb->network_header;
error = 0;
--
2.1.4
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