[PATCH 4/4] netfilter: bridge: rename br_parse_ip_options and delete unneeded code

[PATCH 4/4] netfilter: bridge: rename br_parse_ip_options and delete unneeded code

[Bernhard Thaler]

br_parse_ip_options() does not parse any IP options, it validates IP
packets as a whole and the function name is misleading.

Rename it and delete unneeded assignment of iph variable.

Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
---
 net/bridge/br_netfilter.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 0e129fb..2d73565 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -198,7 +198,7 @@ static inline void nf_bridge_save_header(struct sk_buff *skb)
  * expected format
  */
 
-static int br_parse_ip_options(struct sk_buff *skb)
+static int br_validate_ipv4(struct sk_buff *skb)
 {
 	const struct iphdr *iph;
 	struct net_device *dev = skb->dev;
@@ -300,7 +300,7 @@ bad:
 	return -1;
 }
 
-/* Equivalent to br_parse_ip_options for IPv6 */
+/* Equivalent to br_validate_ipv4 for IPv6 */
 static int br_validate_ipv6(struct sk_buff *skb)
 {
 	const struct ipv6hdr *hdr;
@@ -718,7 +718,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
 
 	nf_bridge_pull_encap_header_rcsum(skb);
 
-	if (br_parse_ip_options(skb))
+	if (br_validate_ipv4(skb))
 		return NF_DROP;
 
 	nf_bridge_put(skb->nf_bridge);
@@ -819,7 +819,7 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
 		nf_bridge->mask |= BRNF_PKT_TYPE;
 	}
 
-	if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
+	if (pf == NFPROTO_IPV4 && br_validate_ipv4(skb))
 		return NF_DROP;
 
 	/* The physdev module checks on this */
@@ -914,7 +914,7 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb)
 	 * boundaries by preserving frag_list rather than refragmenting.
 	 */
 	if (skb->protocol == htons(ETH_P_IP)) {
-		if (br_parse_ip_options(skb))
+		if (br_validate_ipv4(skb))
 			/* Drop invalid packet */
 			return NF_DROP;
 		IPCB(skb)->frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
-- 
1.7.10.4

Re: [PATCH 4/4] netfilter: bridge: rename br_parse_ip_options and delete unneeded code

[Florian Westphal]

Bernhard Thaler <bernhard.thaler@wvnet.at> wrote:
> br_parse_ip_options() does not parse any IP options, it validates IP
> packets as a whole and the function name is misleading.

Right.
> Rename it and delete unneeded assignment of iph variable.

?

I don't see any change in this regard.

[PATCHv2 4/4] netfilter: bridge: rename br_parse_ip_options and delete unneeded code

[Bernhard Thaler]

br_parse_ip_options() does not parse any IP options, it validates IP
packets as a whole and the function name is misleading.

Rename br_parse_ip_options() and delete unneeded double assignment
of iph variable.

Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
---

v2
* first patch did not contain statement removing double iph variable
  assignment

 net/bridge/br_netfilter.c |   11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c
index 0e129fb..fbc206a 100644
--- a/net/bridge/br_netfilter.c
+++ b/net/bridge/br_netfilter.c
@@ -198,7 +198,7 @@ static inline void nf_bridge_save_header(struct sk_buff *skb)
  * expected format
  */
 
-static int br_parse_ip_options(struct sk_buff *skb)
+static int br_validate_ipv4(struct sk_buff *skb)
 {
 	const struct iphdr *iph;
 	struct net_device *dev = skb->dev;
@@ -216,7 +216,6 @@ static int br_parse_ip_options(struct sk_buff *skb)
 	if (!pskb_may_pull(skb, iph->ihl*4))
 		goto inhdr_error;
 
-	iph = ip_hdr(skb);
 	if (unlikely(ip_fast_csum((u8 *)iph, iph->ihl)))
 		goto inhdr_error;
 
@@ -300,7 +299,7 @@ bad:
 	return -1;
 }
 
-/* Equivalent to br_parse_ip_options for IPv6 */
+/* Equivalent to br_validate_ipv4 for IPv6 */
 static int br_validate_ipv6(struct sk_buff *skb)
 {
 	const struct ipv6hdr *hdr;
@@ -718,7 +717,7 @@ static unsigned int br_nf_pre_routing(const struct nf_hook_ops *ops,
 
 	nf_bridge_pull_encap_header_rcsum(skb);
 
-	if (br_parse_ip_options(skb))
+	if (br_validate_ipv4(skb))
 		return NF_DROP;
 
 	nf_bridge_put(skb->nf_bridge);
@@ -819,7 +818,7 @@ static unsigned int br_nf_forward_ip(const struct nf_hook_ops *ops,
 		nf_bridge->mask |= BRNF_PKT_TYPE;
 	}
 
-	if (pf == NFPROTO_IPV4 && br_parse_ip_options(skb))
+	if (pf == NFPROTO_IPV4 && br_validate_ipv4(skb))
 		return NF_DROP;
 
 	/* The physdev module checks on this */
@@ -914,7 +913,7 @@ static int br_nf_dev_queue_xmit(struct sk_buff *skb)
 	 * boundaries by preserving frag_list rather than refragmenting.
 	 */
 	if (skb->protocol == htons(ETH_P_IP)) {
-		if (br_parse_ip_options(skb))
+		if (br_validate_ipv4(skb))
 			/* Drop invalid packet */
 			return NF_DROP;
 		IPCB(skb)->frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size;
-- 
1.7.10.4

Re: [PATCHv2 4/4] netfilter: bridge: rename br_parse_ip_options and delete unneeded code

[Florian Westphal]

Bernhard Thaler <bernhard.thaler@wvnet.at> wrote:
> br_parse_ip_options() does not parse any IP options, it validates IP
> packets as a whole and the function name is misleading.
> 
> Rename br_parse_ip_options() and delete unneeded double assignment
> of iph variable.
> 
> Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
> ---
> @@ -216,7 +216,6 @@ static int br_parse_ip_options(struct sk_buff *skb)
>  	if (!pskb_may_pull(skb, iph->ihl*4))
>  		goto inhdr_error;
>  
> -	iph = ip_hdr(skb);

pskb_may_pull() might invalidate the network header, we have to refetch
iph because of this.