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authorNicolas Dichtel <nicolas.dichtel@6wind.com>2014-12-22 18:22:48 +0100
committerDavid S. Miller <davem@davemloft.net>2014-12-22 16:48:01 -0500
commit2dc49d1680b534877fd20cce52557ea542bb06b6 (patch)
tree888c8e5c7d12add3684c02010d1ef3902a35a4f5 /net/ipv6/tcp_ipv6.c
parent5ad24def21b205a8e91925cd276b0a794b5ace82 (diff)
tcp6: don't move IP6CB before xfrm6_policy_check()
When xfrm6_policy_check() is used, _decode_session6() is called after some intermediate functions. This function uses IP6CB(), thus TCP_SKB_CB() must be prepared after the call of xfrm6_policy_check(). Before this patch, scenarii with IPv6 + TCP + IPsec Transport are broken. Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Reported-by: Huaibin Wang <huaibin.wang@6wind.com> Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/tcp_ipv6.c')
-rw-r--r--net/ipv6/tcp_ipv6.c45
1 files changed, 29 insertions, 16 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 5ff87805258e..9c0b54e87b47 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1387,6 +1387,28 @@ ipv6_pktoptions:
return 0;
}
+static void tcp_v6_fill_cb(struct sk_buff *skb, const struct ipv6hdr *hdr,
+ const struct tcphdr *th)
+{
+ /* This is tricky: we move IP6CB at its correct location into
+ * TCP_SKB_CB(). It must be done after xfrm6_policy_check(), because
+ * _decode_session6() uses IP6CB().
+ * barrier() makes sure compiler won't play aliasing games.
+ */
+ memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
+ sizeof(struct inet6_skb_parm));
+ barrier();
+
+ TCP_SKB_CB(skb)->seq = ntohl(th->seq);
+ TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
+ skb->len - th->doff*4);
+ TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
+ TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
+ TCP_SKB_CB(skb)->tcp_tw_isn = 0;
+ TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
+ TCP_SKB_CB(skb)->sacked = 0;
+}
+
static int tcp_v6_rcv(struct sk_buff *skb)
{
const struct tcphdr *th;
@@ -1418,24 +1440,9 @@ static int tcp_v6_rcv(struct sk_buff *skb)
th = tcp_hdr(skb);
hdr = ipv6_hdr(skb);
- /* This is tricky : We move IPCB at its correct location into TCP_SKB_CB()
- * barrier() makes sure compiler wont play fool^Waliasing games.
- */
- memmove(&TCP_SKB_CB(skb)->header.h6, IP6CB(skb),
- sizeof(struct inet6_skb_parm));
- barrier();
-
- TCP_SKB_CB(skb)->seq = ntohl(th->seq);
- TCP_SKB_CB(skb)->end_seq = (TCP_SKB_CB(skb)->seq + th->syn + th->fin +
- skb->len - th->doff*4);
- TCP_SKB_CB(skb)->ack_seq = ntohl(th->ack_seq);
- TCP_SKB_CB(skb)->tcp_flags = tcp_flag_byte(th);
- TCP_SKB_CB(skb)->tcp_tw_isn = 0;
- TCP_SKB_CB(skb)->ip_dsfield = ipv6_get_dsfield(hdr);
- TCP_SKB_CB(skb)->sacked = 0;
sk = __inet6_lookup_skb(&tcp_hashinfo, skb, th->source, th->dest,
- tcp_v6_iif(skb));
+ inet6_iif(skb));
if (!sk)
goto no_tcp_socket;
@@ -1451,6 +1458,8 @@ process:
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto discard_and_relse;
+ tcp_v6_fill_cb(skb, hdr, th);
+
#ifdef CONFIG_TCP_MD5SIG
if (tcp_v6_inbound_md5_hash(sk, skb))
goto discard_and_relse;
@@ -1482,6 +1491,8 @@ no_tcp_socket:
if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
goto discard_it;
+ tcp_v6_fill_cb(skb, hdr, th);
+
if (skb->len < (th->doff<<2) || tcp_checksum_complete(skb)) {
csum_error:
TCP_INC_STATS_BH(net, TCP_MIB_CSUMERRORS);
@@ -1505,6 +1516,8 @@ do_time_wait:
goto discard_it;
}
+ tcp_v6_fill_cb(skb, hdr, th);
+
if (skb->len < (th->doff<<2)) {
inet_twsk_put(inet_twsk(sk));
goto bad_packet;

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