From 7e6c131e1568dcc2033736739a9880dce1976886 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Thu, 29 Nov 2012 18:39:14 -0500 Subject: [PATCH] tipc: consolidate connection-oriented message reception in one function MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Handling of connection-related message reception is currently scattered around at different places in the code. This makes it harder to verify that things are handled correctly in all possible scenarios. So we consolidate the existing processing of connection-oriented message reception in a single routine. In the process, we convert the chain of if/else into a switch/case for improved readability. A cast on the socket_state in the switch is needed to avoid compile warnings on 32 bit, like "net/tipc/socket.c:1252:2: warning: case value ‘4294967295’ not in enumerated type". This happens because existing tipc code pseudo extends the default linux socket state values with: #define SS_LISTENING -1 /* socket is listening */ #define SS_READY -2 /* socket is connectionless */ It may make sense to add these as _positive_ values to the existing socket state enum list someday, vs. these already existing defines. Signed-off-by: Ying Xue Signed-off-by: Jon Maloy [PG: add cast to fix warning; remove returns from middle of switch] Signed-off-by: Paul Gortmaker --- net/tipc/socket.c | 75 ++++++++++++++++++++++++++++++++--------------- 1 file changed, 51 insertions(+), 24 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index b630f3839ca3..d16a6de32ea1 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1186,6 +1186,53 @@ static int rx_queue_full(struct tipc_msg *msg, u32 queue_size, u32 base) return queue_size >= threshold; } +/** + * filter_connect - Handle all incoming messages for a connection-based socket + * @tsock: TIPC socket + * @msg: message + * + * Returns TIPC error status code and socket error status code + * once it encounters some errors + */ +static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf) +{ + struct socket *sock = tsock->sk.sk_socket; + struct tipc_msg *msg = buf_msg(*buf); + u32 retval = TIPC_ERR_NO_PORT; + + if (msg_mcast(msg)) + return retval; + + switch ((int)sock->state) { + case SS_CONNECTED: + /* Accept only connection-based messages sent by peer */ + if (msg_connected(msg) && tipc_port_peer_msg(tsock->p, msg)) { + if (unlikely(msg_errcode(msg))) { + sock->state = SS_DISCONNECTING; + __tipc_disconnect(tsock->p); + } + retval = TIPC_OK; + } + break; + case SS_CONNECTING: + /* Accept only ACK or NACK message */ + if (msg_connected(msg) || (msg_errcode(msg))) + retval = TIPC_OK; + break; + case SS_LISTENING: + case SS_UNCONNECTED: + /* Accept only SYN message */ + if (!msg_connected(msg) && !(msg_errcode(msg))) + retval = TIPC_OK; + break; + case SS_DISCONNECTING: + break; + default: + pr_err("Unknown socket state %u\n", sock->state); + } + return retval; +} + /** * filter_rcv - validate incoming message * @sk: socket @@ -1203,6 +1250,7 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) struct socket *sock = sk->sk_socket; struct tipc_msg *msg = buf_msg(buf); u32 recv_q_len; + u32 res = TIPC_OK; /* Reject message if it is wrong sort of message for socket */ if (msg_type(msg) > TIPC_DIRECT_MSG) @@ -1212,24 +1260,9 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) if (msg_connected(msg)) return TIPC_ERR_NO_PORT; } else { - if (msg_mcast(msg)) - return TIPC_ERR_NO_PORT; - if (sock->state == SS_CONNECTED) { - if (!msg_connected(msg) || - !tipc_port_peer_msg(tipc_sk_port(sk), msg)) - return TIPC_ERR_NO_PORT; - } else if (sock->state == SS_CONNECTING) { - if (!msg_connected(msg) && (msg_errcode(msg) == 0)) - return TIPC_ERR_NO_PORT; - } else if (sock->state == SS_LISTENING) { - if (msg_connected(msg) || msg_errcode(msg)) - return TIPC_ERR_NO_PORT; - } else if (sock->state == SS_DISCONNECTING) { - return TIPC_ERR_NO_PORT; - } else /* (sock->state == SS_UNCONNECTED) */ { - if (msg_connected(msg) || msg_errcode(msg)) - return TIPC_ERR_NO_PORT; - } + res = filter_connect(tipc_sk(sk), &buf); + if (res != TIPC_OK || buf == NULL) + return res; } /* Reject message if there isn't room to queue it */ @@ -1243,12 +1276,6 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) TIPC_SKB_CB(buf)->handle = 0; __skb_queue_tail(&sk->sk_receive_queue, buf); - /* Initiate connection termination for an incoming 'FIN' */ - if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) { - sock->state = SS_DISCONNECTING; - __tipc_disconnect(tipc_sk_port(sk)); - } - sk->sk_data_ready(sk, 0); return TIPC_OK; } -- 2.20.1