From: Ying Xue Date: Sun, 20 Jan 2013 22:30:09 +0000 (+0100) Subject: tipc: byte-based overload control on socket receive queue X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=aba79f332f46ca8529f3e62a9fc2926c8fe75e44;p=linux-beck.git tipc: byte-based overload control on socket receive queue Change overload control to be purely byte-based, using sk->sk_rmem_alloc as byte counter, and compare it to a calculated upper limit for the socket receive queue. For all connection messages, irrespective of message importance, the overload limit is set to a constant value (i.e, 67MB). This limit should normally never be reached because of the lower limit used by the flow control algorithm, and is there only as a last resort in case a faulty peer doesn't respect the send window limit. For datagram messages, message importance is taken into account when calculating the overload limit. The calculation is based on sk->sk_rcvbuf, and is hence configurable via the socket option SO_RCVBUF. Cc: Neil Horman Signed-off-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: Paul Gortmaker --- diff --git a/net/tipc/socket.c b/net/tipc/socket.c index f6ceecd44749..cbe2f6ecf07a 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -43,7 +43,8 @@ #define SS_LISTENING -1 /* socket is listening */ #define SS_READY -2 /* socket is connectionless */ -#define OVERLOAD_LIMIT_BASE 10000 +#define CONN_OVERLOAD_LIMIT ((TIPC_FLOW_CONTROL_WIN * 2 + 1) * \ + SKB_TRUESIZE(TIPC_MAX_USER_MSG_SIZE)) #define CONN_TIMEOUT_DEFAULT 8000 /* default connect timeout = 8s */ struct tipc_sock { @@ -202,7 +203,6 @@ static int tipc_create(struct net *net, struct socket *sock, int protocol, sock_init_data(sock, sk); sk->sk_backlog_rcv = backlog_rcv; - sk->sk_rcvbuf = TIPC_FLOW_CONTROL_WIN * 2 * TIPC_MAX_USER_MSG_SIZE * 2; sk->sk_data_ready = tipc_data_ready; sk->sk_write_space = tipc_write_space; tipc_sk(sk)->p = tp_ptr; @@ -1141,34 +1141,6 @@ static void tipc_data_ready(struct sock *sk, int len) rcu_read_unlock(); } -/** - * rx_queue_full - determine if receive queue can accept another message - * @msg: message to be added to queue - * @queue_size: current size of queue - * @base: nominal maximum size of queue - * - * Returns 1 if queue is unable to accept message, 0 otherwise - */ -static int rx_queue_full(struct tipc_msg *msg, u32 queue_size, u32 base) -{ - u32 threshold; - u32 imp = msg_importance(msg); - - if (imp == TIPC_LOW_IMPORTANCE) - threshold = base; - else if (imp == TIPC_MEDIUM_IMPORTANCE) - threshold = base * 2; - else if (imp == TIPC_HIGH_IMPORTANCE) - threshold = base * 100; - else - return 0; - - if (msg_connected(msg)) - threshold *= 4; - - return queue_size >= threshold; -} - /** * filter_connect - Handle all incoming messages for a connection-based socket * @tsock: TIPC socket @@ -1246,6 +1218,36 @@ static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf) return retval; } +/** + * rcvbuf_limit - get proper overload limit of socket receive queue + * @sk: socket + * @buf: message + * + * For all connection oriented messages, irrespective of importance, + * the default overload value (i.e. 67MB) is set as limit. + * + * For all connectionless messages, by default new queue limits are + * as belows: + * + * TIPC_LOW_IMPORTANCE (5MB) + * TIPC_MEDIUM_IMPORTANCE (10MB) + * TIPC_HIGH_IMPORTANCE (20MB) + * TIPC_CRITICAL_IMPORTANCE (40MB) + * + * Returns overload limit according to corresponding message importance + */ +static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf) +{ + struct tipc_msg *msg = buf_msg(buf); + unsigned int limit; + + if (msg_connected(msg)) + limit = CONN_OVERLOAD_LIMIT; + else + limit = sk->sk_rcvbuf << (msg_importance(msg) + 5); + return limit; +} + /** * filter_rcv - validate incoming message * @sk: socket @@ -1262,7 +1264,7 @@ 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; + unsigned int limit = rcvbuf_limit(sk, buf); u32 res = TIPC_OK; /* Reject message if it is wrong sort of message for socket */ @@ -1279,15 +1281,13 @@ static u32 filter_rcv(struct sock *sk, struct sk_buff *buf) } /* Reject message if there isn't room to queue it */ - recv_q_len = skb_queue_len(&sk->sk_receive_queue); - if (unlikely(recv_q_len >= (OVERLOAD_LIMIT_BASE / 2))) { - if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE / 2)) - return TIPC_ERR_OVERLOAD; - } + if (sk_rmem_alloc_get(sk) + buf->truesize >= limit) + return TIPC_ERR_OVERLOAD; - /* Enqueue message (finally!) */ + /* Enqueue message */ TIPC_SKB_CB(buf)->handle = 0; __skb_queue_tail(&sk->sk_receive_queue, buf); + skb_set_owner_r(buf, sk); sk->sk_data_ready(sk, 0); return TIPC_OK; @@ -1336,7 +1336,7 @@ static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf) if (!sock_owned_by_user(sk)) { res = filter_rcv(sk, buf); } else { - if (sk_add_backlog(sk, buf, sk->sk_rcvbuf)) + if (sk_add_backlog(sk, buf, rcvbuf_limit(sk, buf))) res = TIPC_ERR_OVERLOAD; else res = TIPC_OK; @@ -1570,6 +1570,7 @@ static int accept(struct socket *sock, struct socket *new_sock, int flags) } else { __skb_dequeue(&sk->sk_receive_queue); __skb_queue_head(&new_sk->sk_receive_queue, buf); + skb_set_owner_r(buf, new_sk); } release_sock(new_sk);