From a4611d3b74b56658438ad1de4737a61a46be0fc0 Mon Sep 17 00:00:00 2001 From: Bernhard Thaler Date: Sat, 30 May 2015 15:29:38 +0200 Subject: [PATCH] netfilter: bridge: re-order check_hbh_len() Prepare check_hbh_len() to be called from newly introduced br_validate_ipv6() in next commit. Signed-off-by: Bernhard Thaler Signed-off-by: Pablo Neira Ayuso --- net/bridge/br_netfilter.c | 111 +++++++++++++++++++------------------- 1 file changed, 56 insertions(+), 55 deletions(-) diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 962d5f867f62..d201ea4440c9 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -264,6 +264,62 @@ drop: return -1; } +/* We only check the length. A bridge shouldn't do any hop-by-hop stuff + * anyway + */ +static int check_hbh_len(struct sk_buff *skb) +{ + unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1); + u32 pkt_len; + const unsigned char *nh = skb_network_header(skb); + int off = raw - nh; + int len = (raw[1] + 1) << 3; + + if ((raw + len) - skb->data > skb_headlen(skb)) + goto bad; + + off += 2; + len -= 2; + + while (len > 0) { + int optlen = nh[off + 1] + 2; + + switch (nh[off]) { + case IPV6_TLV_PAD1: + optlen = 1; + break; + + case IPV6_TLV_PADN: + break; + + case IPV6_TLV_JUMBO: + if (nh[off + 1] != 4 || (off & 3) != 2) + goto bad; + pkt_len = ntohl(*(__be32 *)(nh + off + 2)); + if (pkt_len <= IPV6_MAXPLEN || + ipv6_hdr(skb)->payload_len) + goto bad; + if (pkt_len > skb->len - sizeof(struct ipv6hdr)) + goto bad; + if (pskb_trim_rcsum(skb, + pkt_len + sizeof(struct ipv6hdr))) + goto bad; + nh = skb_network_header(skb); + break; + default: + if (optlen > len) + goto bad; + break; + } + off += optlen; + len -= optlen; + } + if (len == 0) + return 0; +bad: + return -1; +} + static void nf_bridge_update_protocol(struct sk_buff *skb) { switch (skb->nf_bridge->orig_proto) { @@ -549,61 +605,6 @@ static struct net_device *setup_pre_routing(struct sk_buff *skb) return skb->dev; } -/* We only check the length. A bridge shouldn't do any hop-by-hop stuff anyway */ -static int check_hbh_len(struct sk_buff *skb) -{ - unsigned char *raw = (u8 *)(ipv6_hdr(skb) + 1); - u32 pkt_len; - const unsigned char *nh = skb_network_header(skb); - int off = raw - nh; - int len = (raw[1] + 1) << 3; - - if ((raw + len) - skb->data > skb_headlen(skb)) - goto bad; - - off += 2; - len -= 2; - - while (len > 0) { - int optlen = nh[off + 1] + 2; - - switch (nh[off]) { - case IPV6_TLV_PAD1: - optlen = 1; - break; - - case IPV6_TLV_PADN: - break; - - case IPV6_TLV_JUMBO: - if (nh[off + 1] != 4 || (off & 3) != 2) - goto bad; - pkt_len = ntohl(*(__be32 *) (nh + off + 2)); - if (pkt_len <= IPV6_MAXPLEN || - ipv6_hdr(skb)->payload_len) - goto bad; - if (pkt_len > skb->len - sizeof(struct ipv6hdr)) - goto bad; - if (pskb_trim_rcsum(skb, - pkt_len + sizeof(struct ipv6hdr))) - goto bad; - nh = skb_network_header(skb); - break; - default: - if (optlen > len) - goto bad; - break; - } - off += optlen; - len -= optlen; - } - if (len == 0) - return 0; -bad: - return -1; - -} - /* Replicate the checks that IPv6 does on packet reception and pass the packet * to ip6tables, which doesn't support NAT, so things are fairly simple. */ static unsigned int br_nf_pre_routing_ipv6(const struct nf_hook_ops *ops, -- 2.20.1