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2020-12-16net/connector: Add const qualifier to cb_idGeoff Levand1-4/+4
The connector driver never modifies any cb_id passed to it, so add a const qualifier to those arguments so callers can declare their struct cb_id as a constant object. Fixes build warnings like these when passing a constant struct cb_id: warning: passing argument 1 of ‘cn_add_callback’ discards ‘const’ qualifier from pointer target Signed-off-by: Geoff Levand <geoff@infradead.org> Link: https://lore.kernel.org/r/a9e49c9e-67fa-16e7-0a6b-72f6bd30c58a@infradead.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-15/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-22drivers, connector: convert cn_callback_entry.refcnt from atomic_t to refcount_tElena Reshetova1-2/+2
atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable cn_callback_entry.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook <keescook@chromium.org> Reviewed-by: David Windsor <dwindsor@gmail.com> Reviewed-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-07-17drivers: connector: fixed coding style issuesValentin Ilie1-5/+7
V2: Replaced assignment in if statement. Fixed coding style issues. Signed-off-by: Valentin Ilie <valentin.ilie@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-31connector: convert to synchronous netlink message processingPatrick McHardy1-41/+17
Commits 01a16b21 (netlink: kill eff_cap from struct netlink_skb_parms) and c53fa1ed (netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms) removed some members from struct netlink_skb_parms that depend on the current context, all netlink users are now required to do synchronous message processing. connector however queues received messages and processes them in a work queue, which is not valid anymore. This patch converts connector to do synchronous message processing by invoking the registered callback handler directly from the netlink receive function. In order to avoid invoking the callback with connector locks held, a reference count is added to struct cn_callback_entry, the reference is taken when finding a matching callback entry on the device's queue_list and released after the callback handler has been invoked. Signed-off-by: Patrick McHardy <kaber@trash.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-24connector: Convert char *name to const char *nameJoe Perches1-3/+4
Allow more const declarations. Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-25connector: remove lazy workqueue creationTejun Heo1-67/+8
Commit 1a5645bc (connector: create connector workqueue only while needed once) implements lazy workqueue creation for connector workqueue. With cmwq now in place, lazy workqueue creation doesn't make much sense while adding a lot of complexity. Remove it and allocate an ordered workqueue during initialization. This also removes a call to flush_scheduled_work() which is deprecated and scheduled to be removed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02connector: Removed the destruct_data callback since it is always kfree_skb()Philipp Reisner1-2/+2
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02connector: Provide the sender's credentials to the callbackPhilipp Reisner1-3/+4
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-02connector: Keep the skb in cn_callback_dataPhilipp Reisner1-1/+2
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-24Merge branch 'master' of ↵David S. Miller1-1/+1
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/wireless/iwmc3200wifi/netdev.c net/wireless/scan.c
2009-07-21connector: maintainer/mail update.Evgeniy Polyakov1-1/+1
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-17connector: make callback argument type explicitMike Frysinger1-2/+5
The connector documentation states that the argument to the callback function is always a pointer to a struct cn_msg, but rather than encode it in the API itself, it uses a void pointer everywhere. This doesn't make much sense to encode the pointer in documentation as it prevents proper C type checking from occurring and can easily allow people to use the wrong pointer type. So convert the argument type to an explicit struct cn_msg pointer. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-03connector: create connector workqueue only while needed onceFrederic Weisbecker1-11/+69
The netlink connector uses its own workqueue to relay the datas sent from userspace to the appropriate callback. If you launch the test from Documentation/connector and change it a bit to send a high flow of data, you will see thousands of events coming to the "cqueue" workqueue by looking at the workqueue tracer. This flow of events can be sent very quickly. So, to not encumber the kevent workqueue and delay other jobs, the "cqueue" workqueue should remain. But this workqueue is pointless most of the time, it will always be created (assuming you have built it of course) although only developpers with specific needs will use it. So avoid this "most of the time useless task", this patch proposes to create this workqueue only when needed once. The first jobs to be sent to connector callbacks will be sent to kevent while the "cqueue" thread creation will be scheduled to kevent too. The following jobs will continue to be scheduled to keventd until the cqueue workqueue is created, and then the rest of the jobs will continue to perform as usual, through this dedicated workqueue. Each time I tested this patch, only the first event was sent to keventd, the rest has been sent to cqueue which have been created quickly. Also, this patch fixes some trailing whitespaces on the connector files. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-03-24connector: convert to single-threaded workqueueEvgeniy Polyakov1-1/+1
From: Evgeniy Polyakov <johnpol@2ka.mipt.ru> We don't need one cqueue thread for each CPU. cqueue is used for receiving userspace datagrams, which are very rare and thus will happily live with a single queue. Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-29[CONNECTOR]: Cleanup struct cn_callback_entryLi Zefan1-1/+0
- 'cb' is a fake struct member. In a previous patch struct cn_callback was renamed to cn_callback_id, so 'cb' should have been deleted at that time. - 'nls' isn't used and is redundant, we can retrieve this data through cn_callback_entry.pdev->nls. - 'seq' and 'group' should be u32, as they are declared to be u32 in other places. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-29[CONNECTOR]: Cleanup struct cn_queue_devLi Zefan1-1/+0
Struct member netlink_groups is never used, and I don't see how it can be useful. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-09[CONNECTOR]: Don't touch queue dev after decrement of ref count.Li Zefan1-1/+1
cn_queue_free_callback() will touch 'dev'(i.e. cbq->pdev), so it should be called before atomic_dec(&dev->refcnt). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-18[CONNECTOR]: Replace delayed work with usual work queue.Evgeniy Polyakov1-3/+2
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-22WorkStruct: make allyesconfigDavid Howells1-3/+5
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-06-18[CONNECTOR]: Fix warning in cn_queue.cAndreas Schwab1-1/+1
cn_queue.c:130: warning: value computed is not used There is no point in testing the atomic value if the result is thrown away. From Evgeniy: It was created to put implicit smp barrier, but it is not needed there. Signed-off-by: Andreas Schwab <schwab@suse.de> Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-27[CONNECTOR]: async connector mode.Evgeniy Polyakov1-13/+19
If input message rate from userspace is too high, do not drop them, but try to deliver using work queue allocation. Failing there is some kind of congestion control. It also removes warn_on on this condition, which scares people. Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-12[NET]: Add netlink connector.Evgeniy Polyakov1-0/+173
Kernel connector - new userspace <-> kernel space easy to use communication module which implements easy to use bidirectional message bus using netlink as it's backend. Connector was created to eliminate complex skb handling both in send and receive message bus direction. Connector driver adds possibility to connect various agents using as one of it's backends netlink based network. One must register callback and identifier. When driver receives special netlink message with appropriate identifier, appropriate callback will be called. From the userspace point of view it's quite straightforward: socket(); bind(); send(); recv(); But if kernelspace want to use full power of such connections, driver writer must create special sockets, must know about struct sk_buff handling... Connector allows any kernelspace agents to use netlink based networking for inter-process communication in a significantly easier way: int cn_add_callback(struct cb_id *id, char *name, void (*callback) (void *)); void cn_netlink_send(struct cn_msg *msg, u32 __groups, int gfp_mask); struct cb_id { __u32 idx; __u32 val; }; idx and val are unique identifiers which must be registered in connector.h for in-kernel usage. void (*callback) (void *) - is a callback function which will be called when message with above idx.val will be received by connector core. Using connector completely hides low-level transport layer from it's users. Connector uses new netlink ability to have many groups in one socket. [ Incorporating many cleanups and fixes by myself and Andrew Morton -DaveM ] Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: David S. Miller <davem@davemloft.net>