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path: root/include/linux/connector.h
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2023-12-19netlink: introduce typedef for filter functionJiri Pirko1-2/+1
Make the code using filter function a bit nicer by consolidating the filter function arguments using typedef. Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-07-23connector/cn_proc: Add filtering to fix some bugsAnjali Kulkarni1-1/+7
The current proc connector code has the foll. bugs - if there are more than one listeners for the proc connector messages, and one of them deregisters for listening using PROC_CN_MCAST_IGNORE, they will still get all proc connector messages, as long as there is another listener. Another issue is if one client calls PROC_CN_MCAST_LISTEN, and another one calls PROC_CN_MCAST_IGNORE, then both will end up not getting any messages. This patch adds filtering and drops packet if client has sent PROC_CN_MCAST_IGNORE. This data is stored in the client socket's sk_user_data. In addition, we only increment or decrement proc_event_num_listeners once per client. This fixes the above issues. cn_release is the release function added for NETLINK_CONNECTOR. It uses the newly added netlink_release function added to netlink_sock. It will free sk_user_data. Signed-off-by: Anjali Kulkarni <anjali.k.kulkarni@oracle.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-01-21connector: fix a kernel-doc markupMauro Carvalho Chehab1-1/+1
A function has a different name between their prototype and its kernel-doc markup. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Link: https://lore.kernel.org/r/889cfb141a98ae06d5bc79b744786ec2e8f92d93.1610610937.git.mchehab+huawei@kernel.org Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-12-16net/connector: Add const qualifier to cb_idGeoff Levand1-5/+5
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>
2019-07-21connector: remove redundant input callback from cn_devVasily Averin1-1/+0
A small cleanup: this callback is never used. Originally fixed by Stanislav Kinsburskiy <skinsbursky@virtuozzo.com> for OpenVZ7 bug OVZ-6877 cc: stanislav.kinsburskiy@gmail.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-15docs: connector: convert to ReST and rename to connector.rstMauro Carvalho Chehab1-1/+62
As it has some function definitions, move them to connector.h. The remaining conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner1-14/+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>
2014-05-27connector: allow multiple messages to be sent in one packetDavid Fries1-0/+1
This increases the amount of bundling to reduce the number of packets sent. For the one wire use there can be multiple struct w1_netlink_cmd in a struct w1_netlink_msg and multiple of those in struct cn_msg, and with this change multiple of those in a struct nlmsghdr, and at each level the len identifies there being multiple of the next. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-07connector: add portid to unicast in addition to broadcastingDavid Fries1-1/+1
This allows replying only to the requestor portid while still supporting broadcasting. Pass 0 to portid for the previous behavior. Signed-off-by: David Fries <David@Fries.net> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells1-55/+1
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com>
2012-02-02drivers: hv: kvp: Add/cleanup connector definesK. Y. Srinivasan1-0/+1
The current KVP code carries some private connector related defines. Update connector.h to have all the KVP defines. As part of this patch get rid of some unused defines. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2011-08-25MAINTAINERS: Evgeniy has movedEvgeniy Polyakov1-1/+1
Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma1-1/+1
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-07Connector: Set the CN_NETLINK_USERS correctlyK. Y. Srinivasan1-1/+1
The CN_NETLINK_USERS must be set to the highest valid index +1. Thanks to Evgeniy for pointing this out. Signed-off-by: K. Y. Srinivasan <kys@microsoft.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Cc: stable <stable@kernel.org> [.39] Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2011-03-30connector: convert to synchronous netlink message processingPatrick McHardy1-13/+3
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>
2011-02-23connector: Convert char *name to const char *nameJoe Perches1-3/+6
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>
2011-01-20Connector: Add an index to support key/value pair (KVP) functionalityKy Srinivasan1-1/+2
Added a connector index to support key value/pair (KVP) functionality for Linux guests hosted on a HyperV platform. Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-24connector: remove lazy workqueue creationTejun Heo1-8/+0
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>
2010-02-02connector: Delete buggy notification code.Evgeniy Polyakov1-32/+0
On Tue, Feb 02, 2010 at 02:57:14PM -0800, Greg KH (gregkh@suse.de) wrote: > > There are at least two ways to fix it: using a big cannon and a small > > one. The former way is to disable notification registration, since it is > > not used by anyone at all. Second way is to check whether calling > > process is root and its destination group is -1 (kind of priveledged > > one) before command is dispatched to workqueue. > > Well if no one is using it, removing it makes the most sense, right? > > No objection from me, care to make up a patch either way for this? Getting it is not used, let's drop support for notifications about (un)registered events from connector. Another option was to check credentials on receiving, but we can always restore it without bugs if needed, but genetlink has a wider code base and none complained, that userspace can not get notification when some other clients were (un)registered. Kudos for Sebastian Krahmer <krahmer@suse.de>, who found a bug in the code. Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-25drbd: moved CN_IDX_DRBD and CN_VAL_DRBD to the right filePhilipp Reisner1-0/+2
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com> Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
2009-10-02connector: Removed the destruct_data callback since it is always kfree_skb()Philipp Reisner1-3/+0
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/+3
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 Reisner1-2/+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>
2009-07-17connector: make callback argument type explicitMike Frysinger1-3/+3
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>
2009-06-22dm raid1: add userspace logJonthan Brassow1-1/+3
This patch contains a device-mapper mirror log module that forwards requests to userspace for processing. The structures used for communication between kernel and userspace are located in include/linux/dm-log-userspace.h. Due to the frequency, diversity, and 2-way communication nature of the exchanges between kernel and userspace, 'connector' was chosen as the interface for communication. The first log implementations written in userspace - "clustered-disk" and "clustered-core" - support clustered shared storage. A userspace daemon (in the LVM2 source code repository) uses openAIS/corosync to process requests in an ordered fashion with the rest of the nodes in the cluster so as to prevent log state corruption. Other implementations with no association to LVM or openAIS/corosync, are certainly possible. (Imagine if two machines are writing to the same region of a mirror. They would both mark the region dirty, but you need a cluster-aware entity that can handle properly marking the region clean when they are done. Otherwise, you might clear the region when the first machine is done, not the second.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2009-04-03Staging: dst: core files.Evgeniy Polyakov1-1/+3
This patch contains DST core files, which introduce block layer, connector and sysfs registration glue and main headers. Connector is used for the configuration of the node (its type, address, device name and so on). Sysfs provides bits of information about running devices in the following format: +/* + * DST sysfs tree for device called 'storage': + * + * /sys/bus/dst/devices/storage/ + * /sys/bus/dst/devices/storage/type : 192.168.4.80:1025 + * /sys/bus/dst/devices/storage/size : 800 + * /sys/bus/dst/devices/storage/name : storage + */ DST header contains structure definitions and protocol command description. Signed-off-by: Evgeniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-02-02connector: create connector workqueue only while needed onceFrederic Weisbecker1-0/+8
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>
2009-01-15include of <linux/types.h> is preferred over <asm/types.h>Jaswinder Singh Rajput1-1/+1
Impact: fix 15 make headers_check warnings: include of <linux/types.h> is preferred over <asm/types.h> Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30connector: add a BlackBoard user to connectorJerome Arbez-Gindre1-1/+2
Add a BlackBoard user to connector. BlackBoard is part of the TSP GPL sampling framework (http://savannah.nongnu.org/p/tsp) [akpm@linux-foundation.org: add comment] Signed-off-by: Jerome Arbez-Gindre <jeromearbezgindre@gmail.com> Acked-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-26CONNECTOR: make cn_already_initialized staticLi Zefan1-2/+0
It is used in connector.c only, so make it static. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28[CONNECTOR]: Cleanup struct cn_callback_entryLi Zefan1-3/+1
- '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>
2008-01-28[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>
2007-10-16uvesafb: add connector entriesMichal Januszewski1-2/+3
Add connector idx and val constants for v86d and uvesafb. Signed-off-by: Michal Januszewski <spock@gentoo.org> Signed-off-by: Antonino Daplas <adaplas@gmail.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-16connector: change connector's max message sizeMichal Januszewski1-1/+1
Change the maximum message size to 16k to allow transfers of VBE data blocks from userspace. Signed-off-by: Michal Januszewski <spock@gentoo.org> Signed-off-by: Antonino Daplas <adaplas@gmail.com> Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-10-10[NET]: make netlink user -> kernel interface synchroniousDenis V. Lunev1-1/+1
This patch make processing netlink user -> kernel messages synchronious. This change was inspired by the talk with Alexey Kuznetsov about current netlink messages processing. He says that he was badly wrong when introduced asynchronious user -> kernel communication. The call netlink_unicast is the only path to send message to the kernel netlink socket. But, unfortunately, it is also used to send data to the user. Before this change the user message has been attached to the socket queue and sk->sk_data_ready was called. The process has been blocked until all pending messages were processed. The bad thing is that this processing may occur in the arbitrary process context. This patch changes nlk->data_ready callback to get 1 skb and force packet processing right in the netlink_unicast. Kernel -> user path in netlink_unicast remains untouched. EINTR processing for in netlink_run_queue was changed. It forces rtnl_lock drop, but the process remains in the cycle until the message will be fully processed. So, there is no need to use this kludges now. Signed-off-by: Denis V. Lunev <den@openvz.org> Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-12-18[CONNECTOR]: Replace delayed work with usual work queue.Evgeniy Polyakov1-1/+1
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2006-11-22WorkStruct: make allyesconfigDavid Howells1-2/+2
Fix up for make allyesconfig. Signed-Off-By: David Howells <dhowells@redhat.com>
2006-06-22[PATCH] w1: Move w1-connector definitions into linux/include/connector.hEvgeniy Polyakov1-1/+4
Signed-off-by: Evgeniy Polyakov <johnpol@2ka.mipt.ru> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2005-11-10[CIFS] Reserve upcall IDX value for CIFS with connector header and addSteve French1-0/+2
Kconfig option for CIFS upcall. Signed-off-by: Steve French <sfrench@us.ibm.com>
2005-11-07[PATCH] Process Events ConnectorMatt Helsley1-0/+6
This patch adds a connector that reports fork, exec, id change, and exit events for all processes to userspace. It replaces the fork_advisor patch that ELSA is currently using. Applications that may find these events useful include accounting/auditing (e.g. ELSA), system activity monitoring (e.g. top), security, and resource management (e.g. CKRM). Signed-off-by: Matt Helsley <matthltc@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-08[PATCH] gfp flags annotations - part 1Al Viro1-1/+1
- added typedef unsigned int __nocast gfp_t; - replaced __nocast uses for gfp flags with gfp_t - it gives exactly the same warnings as far as sparse is concerned, doesn't change generated code (from gcc point of view we replaced unsigned int with typedef) and documents what's going on far better. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-10-04[CONNECTOR]: fix sparse gfp nocast warningsRandy Dunlap1-1/+1
Fix implicit nocast warnings in connector code: drivers/connector/connector.c:102:24: warning: implicit cast to nocast type drivers/connector/connector.c:114:45: warning: implicit cast to nocast type Signed-off-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-26[CONNECTOR]: async connector mode.Evgeniy Polyakov1-6/+15
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>
2005-09-11[NET]: Add netlink connector.Evgeniy Polyakov1-0/+158
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>