From 1b05c4b50edbddbdde715c4a7350629819f6655e Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Tue, 25 Sep 2012 07:03:40 +0000 Subject: [PATCH] ipv6: raw: fix icmpv6_filter() icmpv6_filter() should not modify its input, or else its caller would need to recompute ipv6_hdr() if skb->head is reallocated. Use skb_header_pointer() instead of pskb_may_pull() and change the prototype to make clear both sk and skb are const. Also, if icmpv6 header cannot be found, do not deliver the packet, as we do in IPv4. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv6/raw.c | 21 ++++++++++----------- 1 file changed, 10 insertions(+), 11 deletions(-) diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index ef0579d5bca6..4a5f78b50495 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -107,21 +107,20 @@ found: * 0 - deliver * 1 - block */ -static __inline__ int icmpv6_filter(struct sock *sk, struct sk_buff *skb) +static int icmpv6_filter(const struct sock *sk, const struct sk_buff *skb) { - struct icmp6hdr *icmph; - struct raw6_sock *rp = raw6_sk(sk); + struct icmp6hdr *_hdr; + const struct icmp6hdr *hdr; - if (pskb_may_pull(skb, sizeof(struct icmp6hdr))) { - __u32 *data = &rp->filter.data[0]; - int bit_nr; + hdr = skb_header_pointer(skb, skb_transport_offset(skb), + sizeof(_hdr), &_hdr); + if (hdr) { + const __u32 *data = &raw6_sk(sk)->filter.data[0]; + unsigned int type = hdr->icmp6_type; - icmph = (struct icmp6hdr *) skb->data; - bit_nr = icmph->icmp6_type; - - return (data[bit_nr >> 5] & (1 << (bit_nr & 31))) != 0; + return (data[type >> 5] & (1U << (type & 31))) != 0; } - return 0; + return 1; } #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE)