From f19008e676366c44e9241af57f331b6c6edf9552 Mon Sep 17 00:00:00 2001 From: Jason Baron Date: Mon, 10 Aug 2020 13:38:39 -0400 Subject: tcp: correct read of TFO keys on big endian systems When TFO keys are read back on big endian systems either via the global sysctl interface or via getsockopt() using TCP_FASTOPEN_KEY, the values don't match what was written. For example, on s390x: # echo "1-2-3-4" > /proc/sys/net/ipv4/tcp_fastopen_key # cat /proc/sys/net/ipv4/tcp_fastopen_key 02000000-01000000-04000000-03000000 Instead of: # cat /proc/sys/net/ipv4/tcp_fastopen_key 00000001-00000002-00000003-00000004 Fix this by converting to the correct endianness on read. This was reported by Colin Ian King when running the 'tcp_fastopen_backup_key' net selftest on s390x, which depends on the read value matching what was written. I've confirmed that the test now passes on big and little endian systems. Signed-off-by: Jason Baron Fixes: 438ac88009bc ("net: fastopen: robustness and endianness fixes for SipHash") Cc: Ard Biesheuvel Cc: Eric Dumazet Reported-and-tested-by: Colin Ian King Signed-off-by: David S. Miller --- include/net/tcp.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/net/tcp.h') diff --git a/include/net/tcp.h b/include/net/tcp.h index dbf5c791a6eb..eab6c7510b5b 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1672,6 +1672,8 @@ void tcp_fastopen_destroy_cipher(struct sock *sk); void tcp_fastopen_ctx_destroy(struct net *net); int tcp_fastopen_reset_cipher(struct net *net, struct sock *sk, void *primary_key, void *backup_key); +int tcp_fastopen_get_cipher(struct net *net, struct inet_connection_sock *icsk, + u64 *key); void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb); struct sock *tcp_try_fastopen(struct sock *sk, struct sk_buff *skb, struct request_sock *req, -- cgit v1.2.3