diff options
| author | Patrick McHardy <kaber@trash.net> | 2008-04-12 18:35:41 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-04-12 18:35:41 -0700 |
| commit | 028b027524b162eef90839a92ba4b8bddf23e06c (patch) | |
| tree | 5c128717f73ff6fb93c361cfae6961267ed52082 /net/dccp | |
| parent | ae1b6a31b1f9ef2c7ba5ef89799f210a9ba6937c (diff) | |
| download | lwn-028b027524b162eef90839a92ba4b8bddf23e06c.tar.gz lwn-028b027524b162eef90839a92ba4b8bddf23e06c.zip | |
[DCCP]: Fix skb->cb conflicts with IP
dev_queue_xmit() and the other IP output functions expect to get a skb
with clear or properly initialized skb->cb. Unlike TCP and UDP, the
dccp_skb_cb doesn't contain a struct inet_skb_parm at the beginning,
so the DCCP-specific data is interpreted by the IP output functions.
This can cause false negatives for the conditional POST_ROUTING hook
invocation, making the packet bypass the hook.
Add a inet_skb_parm/inet6_skb_parm union to the beginning of
dccp_skb_cb to avoid clashes. Also add a BUILD_BUG_ON to make
sure it fits in the cb.
[ Combined with patch from Gerrit Renker to remove two now unnecessary
memsets of IPCB(skb)->opt ]
Signed-off-by: Patrick McHardy <kaber@trash.net>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/dccp')
| -rw-r--r-- | net/dccp/dccp.h | 6 | ||||
| -rw-r--r-- | net/dccp/ipv4.c | 1 | ||||
| -rw-r--r-- | net/dccp/output.c | 1 | ||||
| -rw-r--r-- | net/dccp/proto.c | 3 |
4 files changed, 9 insertions, 2 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h index 287a62bc2e0f..ba2ef94a2302 100644 --- a/net/dccp/dccp.h +++ b/net/dccp/dccp.h @@ -325,6 +325,12 @@ static inline int dccp_bad_service_code(const struct sock *sk, * This is used for transmission as well as for reception. */ struct dccp_skb_cb { + union { + struct inet_skb_parm h4; +#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) + struct inet6_skb_parm h6; +#endif + } header; __u8 dccpd_type:4; __u8 dccpd_ccval:4; __u8 dccpd_reset_code, diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 474075adbde4..b33704415555 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -489,7 +489,6 @@ static int dccp_v4_send_response(struct sock *sk, struct request_sock *req, dh->dccph_checksum = dccp_v4_csum_finish(skb, ireq->loc_addr, ireq->rmt_addr); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); err = ip_build_and_send_pkt(skb, sk, ireq->loc_addr, ireq->rmt_addr, ireq->opt); diff --git a/net/dccp/output.c b/net/dccp/output.c index 3b763db3d863..3d7d628d870d 100644 --- a/net/dccp/output.c +++ b/net/dccp/output.c @@ -126,7 +126,6 @@ static int dccp_transmit_skb(struct sock *sk, struct sk_buff *skb) DCCP_INC_STATS(DCCP_MIB_OUTSEGS); - memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt)); err = icsk->icsk_af_ops->queue_xmit(skb, 0); return net_xmit_eval(err); } diff --git a/net/dccp/proto.c b/net/dccp/proto.c index e3f5d37b84be..c91d3c1fd30d 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -1057,6 +1057,9 @@ static int __init dccp_init(void) int ehash_order, bhash_order, i; int rc = -ENOBUFS; + BUILD_BUG_ON(sizeof(struct dccp_skb_cb) > + FIELD_SIZEOF(struct sk_buff, cb)); + dccp_hashinfo.bind_bucket_cachep = kmem_cache_create("dccp_bind_bucket", sizeof(struct inet_bind_bucket), 0, |