diff options
| author | Andy Zhou <azhou@nicira.com> | 2015-05-15 23:15:37 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-05-19 06:15:39 +0200 |
| commit | 49d16b23cd1e61c028ee088c5a64e9ac6a9c6147 (patch) | |
| tree | 446c416b396c4561bd5616f6fba2ef52c43c8d06 /net/bridge | |
| parent | IPv4: skip ICMP for bridge contrack users when defrag expires (diff) | |
| download | linux-49d16b23cd1e61c028ee088c5a64e9ac6a9c6147.tar.xz linux-49d16b23cd1e61c028ee088c5a64e9ac6a9c6147.zip | |
bridge_netfilter: No ICMP packet on IPv4 fragmentation error
When bridge netfilter re-fragments an IP packet for output, all
packets that can not be re-fragmented to their original input size
should be silently discarded.
However, current bridge netfilter output path generates an ICMP packet
with 'size exceeded MTU' message for such packets, this is a bug.
This patch refactors the ip_fragment() API to allow two separate
use cases. The bridge netfilter user case will not
send ICMP, the routing output will, as before.
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/bridge')
| -rw-r--r-- | net/bridge/br_netfilter.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/net/bridge/br_netfilter.c b/net/bridge/br_netfilter.c index 2b0e8bb49944..1d2eb32d8270 100644 --- a/net/bridge/br_netfilter.c +++ b/net/bridge/br_netfilter.c @@ -853,6 +853,25 @@ static int br_nf_push_frag_xmit(struct sock *sk, struct sk_buff *skb) return br_dev_queue_push_xmit(sk, skb); } +static int br_nf_ip_fragment(struct sock *sk, struct sk_buff *skb, + int (*output)(struct sock *, struct sk_buff *)) +{ + unsigned int mtu = ip_skb_dst_mtu(skb); + struct iphdr *iph = ip_hdr(skb); + struct rtable *rt = skb_rtable(skb); + struct net_device *dev = rt->dst.dev; + + if (unlikely(((iph->frag_off & htons(IP_DF)) && !skb->ignore_df) || + (IPCB(skb)->frag_max_size && + IPCB(skb)->frag_max_size > mtu))) { + IP_INC_STATS(dev_net(dev), IPSTATS_MIB_FRAGFAILS); + kfree_skb(skb); + return -EMSGSIZE; + } + + return ip_do_fragment(sk, skb, output); +} + static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb) { int ret; @@ -886,7 +905,7 @@ static int br_nf_dev_queue_xmit(struct sock *sk, struct sk_buff *skb) skb_copy_from_linear_data_offset(skb, -data->size, data->mac, data->size); - ret = ip_fragment(sk, skb, br_nf_push_frag_xmit); + ret = br_nf_ip_fragment(sk, skb, br_nf_push_frag_xmit); } else { nf_bridge_info_free(skb); ret = br_dev_queue_push_xmit(sk, skb); |