tcp repair: Fix unaligned access when repairing options (v2)

From: Pavel Emelyanov <[email protected]>

Don't pick __u8/__u16 values directly from raw pointers, but instead use an array of structures of code:value pairs. This is OK, since the buffer we take options from is not an skb memory, but a user-to-kernel one.

For those options which don't require any value now, require this to be zero (for potential future extension of this API).

v2: Changed tcp_repair_opt to use two __u32-s as spotted by David Laight.

---
 include/linux/tcp.h |    5 ++++
 net/ipv4/tcp.c      |   60 +++++++++++++++++---------------------------------
 2 files changed, 26 insertions(+), 39 deletions(-)

index 9865936..d0401d9 100644
@@ -111,6 +111,11 @@ enum {
 #define TCP_QUEUE_SEQ		21
 #define TCP_REPAIR_OPTIONS	22
 
+struct tcp_repair_opt {
+	__u32	opt_code;
+	__u32	opt_val;
+};
+
 enum {
 	TCP_NO_QUEUE,
 	TCP_RECV_QUEUE,

From: Pavel Emelyanov <[email protected]>
Date: Thu, 26 Apr 2012 13:43:04 +0400

Seems to have worked this time, applied :-)