From cc79dd1ba9c1021c2ac6ae200a65ec38ee8db351 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 17 Jun 2013 10:54:37 -0400 Subject: tipc: change socket buffer overflow control to respect sk_rcvbuf 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 Cc: Neil Horman Cc: Jon Maloy [Ying: added sysctl variation to Jon's original patch] Signed-off-by: Ying Xue [PG: don't compile sysctl.c if not config'd; add Documentation] Signed-off-by: Paul Gortmaker Signed-off-by: David S. Miller --- net/tipc/core.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'net/tipc/core.h') diff --git a/net/tipc/core.h b/net/tipc/core.h index 0207db04179a..fe7f2b7c19fe 100644 --- a/net/tipc/core.h +++ b/net/tipc/core.h @@ -80,6 +80,7 @@ extern u32 tipc_own_addr __read_mostly; extern int tipc_max_ports __read_mostly; extern int tipc_net_id __read_mostly; extern int tipc_remote_management __read_mostly; +extern int sysctl_tipc_rmem[3] __read_mostly; /* * Other global variables @@ -97,6 +98,14 @@ extern void tipc_netlink_stop(void); extern int tipc_socket_init(void); extern void tipc_socket_stop(void); +#ifdef CONFIG_SYSCTL +extern int tipc_register_sysctl(void); +extern void tipc_unregister_sysctl(void); +#else +#define tipc_register_sysctl() 0 +#define tipc_unregister_sysctl() +#endif + /* * TIPC timer and signal code */ -- cgit v1.2.3 From c5fa7b3cf3cb22e4ac60485fc2dc187fe012910f Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Mon, 17 Jun 2013 10:54:39 -0400 Subject: tipc: introduce new TIPC server infrastructure TIPC has two internal servers, one providing a subscription service for topology events, and another providing the configuration interface. These servers have previously been running in BH context, accessing the TIPC-port (aka native) API directly. Apart from these servers, even the TIPC socket implementation is partially built on this API. As this API may simultaneously be called via different paths and in different contexts, a complex and costly lock policiy is required in order to protect TIPC internal resources. To eliminate the need for this complex lock policiy, we introduce a new, generic service API that uses kernel sockets for message passing instead of the native API. Once the toplogy and configuration servers are converted to use this new service, all code pertaining to the native API can be removed. This entails a significant reduction in code amount and complexity, and opens up for a complete rework of the locking policy in TIPC. The new service also solves another problem: As the current topology server works in BH context, it cannot easily be blocked when sending of events fails due to congestion. In such cases events may have to be silently dropped, something that is unacceptable. Therefore, the new service keeps a dedicated outbound queue receiving messages from BH context. Once messages are inserted into this queue, we will immediately schedule a work from a special workqueue. This way, messages/events from the topology server are in reality sent in process context, and the server can block if necessary. Analogously, there is a new workqueue for receiving messages. Once a notification about an arriving message is received in BH context, we schedule a work from the receive workqueue to do the job of receiving the message in process context. As both sending and receive messages are now finished in processes, subscribed events cannot be dropped any more. As of this commit, this new server infrastructure is built, but not actually yet called by the existing TIPC code, but since the conversion changes required in order to use it are significant, the addition is kept here as a separate commit. Signed-off-by: Ying Xue Signed-off-by: Jon Maloy Signed-off-by: Paul Gortmaker Signed-off-by: David S. Miller --- net/tipc/core.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/tipc/core.h') diff --git a/net/tipc/core.h b/net/tipc/core.h index fe7f2b7c19fe..be72f8cebc53 100644 --- a/net/tipc/core.h +++ b/net/tipc/core.h @@ -1,8 +1,8 @@ /* * net/tipc/core.h: Include file for TIPC global declarations * - * Copyright (c) 2005-2006, Ericsson AB - * Copyright (c) 2005-2007, 2010-2011, Wind River Systems + * Copyright (c) 2005-2006, 2013 Ericsson AB + * Copyright (c) 2005-2007, 2010-2013, Wind River Systems * All rights reserved. * * Redistribution and use in source and binary forms, with or without @@ -97,6 +97,10 @@ extern int tipc_netlink_start(void); extern void tipc_netlink_stop(void); extern int tipc_socket_init(void); extern void tipc_socket_stop(void); +extern int tipc_sock_create_local(int type, struct socket **res); +extern void tipc_sock_release_local(struct socket *sock); +extern int tipc_sock_accept_local(struct socket *sock, + struct socket **newsock, int flags); #ifdef CONFIG_SYSCTL extern int tipc_register_sysctl(void); -- cgit v1.2.3