[TCP]: struct tcp_sack_block annotations

Some of the instances of tcp_sack_block are host-endian, some - net-endian.
Define struct tcp_sack_block_wire identical to struct tcp_sack_block
with u32 replaced with __be32; annotate uses of tcp_sack_block replacing
net-endian ones with tcp_sack_block_wire.  Change is obviously safe since
for cc(1) __be32 is typedefed to u32.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 7 insertions, 2 deletions

diff --git a/include/linux/tcp.h b/include/linux/tcp.h
index 543f06371840..9632aa866de4 100644
--- a/include/linux/tcp.h
+++ b/include/linux/tcp.h
@@ -166,6 +166,11 @@ struct tcp_info
 #include <net/inet_timewait_sock.h>
 
 /* This defines a selective acknowledgement block. */
+struct tcp_sack_block_wire {
+        __be32  start_seq;
+        __be32  end_seq;
+};
+
 struct tcp_sack_block {
         __u32   start_seq;
         __u32   end_seq;
diff --git a/net/ipv4/netfilter/ip_nat_helper.c b/net/ipv4/netfilter/ip_nat_helper.c
index 7f6a75984f6c..e9c5187ea5b2 100644
--- a/net/ipv4/netfilter/ip_nat_helper.c
+++ b/net/ipv4/netfilter/ip_nat_helper.c
@@ -283,7 +283,7 @@ sack_adjust(struct sk_buff *skb,
             struct ip_nat_seq *natseq)
 {
         while (sackoff < sackend) {
-                struct tcp_sack_block *sack;
+                struct tcp_sack_block_wire *sack;
                 u_int32_t new_start_seq, new_end_seq;
 
                 sack = (void *)skb->data + sackoff;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b3def0df14fb..46984ffd73cd 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -935,7 +935,7 @@ tcp_sacktag_write_queue(struct sock *sk, struct sk_buff *ack_skb, u32 prior_snd_
         const struct inet_connection_sock *icsk = inet_csk(sk);
         struct tcp_sock *tp = tcp_sk(sk);
         unsigned char *ptr = ack_skb->h.raw + TCP_SKB_CB(ack_skb)->sacked;
-        struct tcp_sack_block *sp = (struct tcp_sack_block *)(ptr+2);
+        struct tcp_sack_block_wire *sp = (struct tcp_sack_block_wire *)(ptr+2);
         int num_sacks = (ptr[1] - TCPOLEN_SACK_BASE)>>3;
         int reord = tp->packets_out;
         int prior_fackets;