[PATCH net-next v2] openvswitch: Derive IP protocol number for IPv6 later frags

[PATCH net-next v2] openvswitch: Derive IP protocol number for IPv6 later frags

[Yi-Hung Wei]

Currently, OVS only parses the IP protocol number for the first
IPv6 fragment, but sets the IP protocol number for the later fragments
to be NEXTHDF_FRAGMENT.  This patch tries to derive the IP protocol
number for the IPV6 later frags so that we can match that.

Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
---
 net/openvswitch/flow.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c
index 56b8e7167790..35966da84769 100644
--- a/net/openvswitch/flow.c
+++ b/net/openvswitch/flow.c
@@ -254,21 +254,18 @@ static bool icmphdr_ok(struct sk_buff *skb)
 
 static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 {
+	unsigned short frag_off;
+	unsigned int payload_ofs = 0;
 	unsigned int nh_ofs = skb_network_offset(skb);
 	unsigned int nh_len;
-	int payload_ofs;
 	struct ipv6hdr *nh;
-	uint8_t nexthdr;
-	__be16 frag_off;
-	int err;
+	int err, nexthdr, flags = 0;
 
 	err = check_header(skb, nh_ofs + sizeof(*nh));
 	if (unlikely(err))
 		return err;
 
 	nh = ipv6_hdr(skb);
-	nexthdr = nh->nexthdr;
-	payload_ofs = (u8 *)(nh + 1) - skb->data;
 
 	key->ip.proto = NEXTHDR_NONE;
 	key->ip.tos = ipv6_get_dsfield(nh);
@@ -277,10 +274,9 @@ static int parse_ipv6hdr(struct sk_buff *skb, struct sw_flow_key *key)
 	key->ipv6.addr.src = nh->saddr;
 	key->ipv6.addr.dst = nh->daddr;
 
-	payload_ofs = ipv6_skip_exthdr(skb, payload_ofs, &nexthdr, &frag_off);
-
-	if (frag_off) {
-		if (frag_off & htons(~0x7))
+	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
+	if (flags & IP6_FH_F_FRAG) {
+		if (frag_off)
 			key->ip.frag = OVS_FRAG_TYPE_LATER;
 		else
 			key->ip.frag = OVS_FRAG_TYPE_FIRST;
@@ -288,11 +284,11 @@ 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
+	/* Delayed handling of error in ipv6_find_hdr() as it
+	 * always sets flags and frag_off to a valid value which may be
 	 * used to set key->ip.frag above.
 	 */
-	if (unlikely(payload_ofs < 0))
+	if (unlikely(nexthdr < 0))
 		return -EPROTO;
 
 	nh_len = payload_ofs - nh_ofs;
-- 
2.7.4

Re: [PATCH net-next v2] openvswitch: Derive IP protocol number for IPv6 later frags

[Pravin Shelar]

On Tue, Sep 4, 2018 at 3:37 PM Yi-Hung Wei <yihung.wei@gmail.com> wrote:
>
> Currently, OVS only parses the IP protocol number for the first
> IPv6 fragment, but sets the IP protocol number for the later fragments
> to be NEXTHDF_FRAGMENT.  This patch tries to derive the IP protocol
> number for the IPV6 later frags so that we can match that.
>
> Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>
Acked-by: Pravin B Shelar <pshelar@ovn.org>

Thanks.

Re: [PATCH net-next v2] openvswitch: Derive IP protocol number for IPv6 later frags

[David Miller]

From: Yi-Hung Wei <yihung.wei@gmail.com>
Date: Tue,  4 Sep 2018 15:33:41 -0700

> Currently, OVS only parses the IP protocol number for the first
> IPv6 fragment, but sets the IP protocol number for the later fragments
> to be NEXTHDF_FRAGMENT.  This patch tries to derive the IP protocol
> number for the IPV6 later frags so that we can match that.
> 
> Signed-off-by: Yi-Hung Wei <yihung.wei@gmail.com>

Applied.