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tipc: change socket buffer overflow control to respect sk_rcvbuf

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As per feedback from the netdev community, we change the buffer
overflow protection algorithm in receiving sockets so that it
always respects the nominal upper limit set in sk_rcvbuf.

Instead of scaling up from a small sk_rcvbuf value, which leads to
violation of the configured sk_rcvbuf limit, we now calculate the
weighted per-message limit by scaling down from a much bigger value,
still in the same field, according to the importance priority of the
received message.

To allow for administrative tunability of the socket receive buffer
size, we create a tipc_rmem sysctl variable to allow the user to
configure an even bigger value via sysctl command.  It is a size of
three (min/default/max) to be consistent with things like tcp_rmem.

By default, the value initialized in tipc_rmem[1] is equal to the
receive socket size needed by a TIPC_CRITICAL_IMPORTANCE message.
This value is also set as the default value of sk_rcvbuf.

Originally-by: Jon Maloy <jon.maloy@ericsson.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
[Ying: added sysctl variation to Jon's original patch]
Signed-off-by: Ying Xue <ying.xue@windriver.com>
[PG: don't compile sysctl.c if not config'd; add Documentation]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ying Xue
2013-06-17 10:54:37 -04:00
committed by David S. Miller
parent 8941bbcd57
commit cc79dd1ba9
7 changed files with 112 additions and 12 deletions
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19
net/tipc/socket.c
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@ -43,8 +43,6 @@
#define SS_LISTENING -1 /* socket is listening */
#define SS_READY -2 /* socket is connectionless */
#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 {
@ -203,6 +201,7 @@ 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 = sysctl_tipc_rmem[1];
sk->sk_data_ready = tipc_data_ready;
sk->sk_write_space = tipc_write_space;
tipc_sk(sk)->p = tp_ptr;
@ -1233,10 +1232,10 @@ static u32 filter_connect(struct tipc_sock *tsock, struct sk_buff **buf)
* 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)
* TIPC_LOW_IMPORTANCE (4 MB)
* TIPC_MEDIUM_IMPORTANCE (8 MB)
* TIPC_HIGH_IMPORTANCE (16 MB)
* TIPC_CRITICAL_IMPORTANCE (32 MB)
*
* Returns overload limit according to corresponding message importance
*/
@ -1246,9 +1245,10 @@ static unsigned int rcvbuf_limit(struct sock *sk, struct sk_buff *buf)
unsigned int limit;
if (msg_connected(msg))
limit = CONN_OVERLOAD_LIMIT;
limit = sysctl_tipc_rmem[2];
else
limit = sk->sk_rcvbuf << (msg_importance(msg) + 5);
limit = sk->sk_rcvbuf >> TIPC_CRITICAL_IMPORTANCE <<
msg_importance(msg);
return limit;
}
@ -1847,7 +1847,8 @@ static const struct net_proto_family tipc_family_ops = {
static struct proto tipc_proto = {
.name = "TIPC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct tipc_sock)
.obj_size = sizeof(struct tipc_sock),
.sysctl_rmem = sysctl_tipc_rmem
};
/**