diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index bca51a351b0e..27ce13ece510 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2790,16 +2790,24 @@ static int do_tcp_setsockopt(struct sock *sk, int level, return err; } case TCP_FASTOPEN_KEY: { - __u8 key[TCP_FASTOPEN_KEY_LENGTH]; + __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH]; + __u8 *backup_key = NULL; - if (optlen != sizeof(key)) + /* Allow a backup key as well to facilitate key rotation + * First key is the active one. + */ + if (optlen != TCP_FASTOPEN_KEY_LENGTH && + optlen != TCP_FASTOPEN_KEY_BUF_LENGTH) return -EINVAL; if (copy_from_user(key, optval, optlen)) return -EFAULT; - return tcp_fastopen_reset_cipher(net, sk, key, NULL, - sizeof(key)); + if (optlen == TCP_FASTOPEN_KEY_BUF_LENGTH) + backup_key = key + TCP_FASTOPEN_KEY_LENGTH; + + return tcp_fastopen_reset_cipher(net, sk, key, backup_key, + TCP_FASTOPEN_KEY_LENGTH); } default: /* fallthru */ @@ -3453,21 +3461,23 @@ static int do_tcp_getsockopt(struct sock *sk, int level, return 0; case TCP_FASTOPEN_KEY: { - __u8 key[TCP_FASTOPEN_KEY_LENGTH]; + __u8 key[TCP_FASTOPEN_KEY_BUF_LENGTH]; struct tcp_fastopen_context *ctx; + unsigned int key_len = 0; if (get_user(len, optlen)) return -EFAULT; rcu_read_lock(); ctx = rcu_dereference(icsk->icsk_accept_queue.fastopenq.ctx); - if (ctx) - memcpy(key, ctx->key, sizeof(key)); - else - len = 0; + if (ctx) { + key_len = tcp_fastopen_context_len(ctx) * + TCP_FASTOPEN_KEY_LENGTH; + memcpy(&key[0], &ctx->key[0], key_len); + } rcu_read_unlock(); - len = min_t(unsigned int, len, sizeof(key)); + len = min_t(unsigned int, len, key_len); if (put_user(len, optlen)) return -EFAULT; if (copy_to_user(optval, key, len))