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path: root/include/linux/sysctl.h
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2012-11-18sysctl: Pass useful parameters to sysctl permissionsEric W. Biederman
- Current is implicitly avaiable so passing current->nsproxy isn't useful. - The ctl_table_header is needed to find how the sysctl table is connected to the rest of sysctl. - ctl_table_root is avaiable in the ctl_table_header so no need to it. With these changes it becomes possible to write a version of net_sysctl_permission that takes into account the network namespace of the sysctl table, an important feature in extending the user namespace. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-10-13UAPI: (Scripted) Disintegrate include/linuxDavid Howells
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>
2012-01-24sysctl: Add register_sysctl for normal sysctl usersEric W. Biederman
The plan is to convert all callers of register_sysctl_table and register_sysctl_paths to register_sysctl. The interface to register_sysctl is enough nicer this should make the callers a bit more readable. Additionally after the conversion the 230 lines of backwards compatibility can be removed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Index sysctl directories with rbtrees.Eric W. Biederman
One of the most important jobs of sysctl is to export network stack tunables. Several of those tunables are per network device. In several instances people are running with 1000+ network devices in there network stacks, which makes the simple per directory linked list in sysctl a scaling bottleneck. Replace O(N^2) sysctl insertion and lookup times with O(NlogN) by using an rbtree to index the sysctl directories. Benchmark before: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Benchmark after: make-dummies 0 999 -> 0.074s rmmod dummy -> 0.070s make-dummies 0 9999 -> 3.4s rmmod dummy -> 0.44s Benchmark after (without dev_snmp6): make-dummies 0 9999 -> 0.75s rmmod dummy -> 0.44s make-dummies 0 99999 -> 11s rmmod dummy -> 4.3s At 10,000 dummy devices the bottleneck becomes the time to add and remove the files under /proc/sys/net/dev_snmp6. I have commented out the code that adds and removes files under /proc/sys/net/dev_snmp6 and taken measurments of creating and destroying 100,000 dummies to verify the sysctl continues to scale. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Make the header lists per directory.Eric W. Biederman
Slightly enhance efficiency and clarity of the code by making the header list per directory instead of per set. Benchmark before: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s Benchmark after: make-dummies 0 999 -> 0.32s rmmod dummy -> 0.12s make-dummies 0 9999 -> 1m17s rmmod dummy -> 17s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Modify __register_sysctl_paths to take a set instead of a root and ↵Eric W. Biederman
an nsproxy An nsproxy argument here has always been awkard and now the nsproxy argument is completely unnecessary so remove it, replacing it with the set we want the registered tables to show up in. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Replace root_list with links between sysctl_table_sets.Eric W. Biederman
Piecing together directories by looking first in one directory tree, than in another directory tree and finally in a third directory tree makes it hard to verify that some directory entries are not multiply defined and makes it hard to create efficient implementations the sysctl filesystem. Replace the sysctl wide list of roots with autogenerated links from the core sysctl directory tree to the other sysctl directory trees. This simplifies sysctl directory reading and lookups as now only entries in a single sysctl directory tree need to be considered. Benchmark before: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.63s rmmod dummy -> 0.12s make-dummies 0 9999 -> 2m35s rmmod dummy -> 18s The slowdown is caused by the lookups used in insert_headers and put_links to see if we need to add links or remove links. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Stop requiring explicit management of sysctl directoriesEric W. Biederman
Simplify the code and the sysctl semantics by autogenerating sysctl directories when a sysctl table is registered that needs the directories and autodeleting the directories when there are no more sysctl tables registered that need them. Autogenerating directories keeps sysctl tables from depending on each other, removing all of the arcane register/unregister ordering constraints and makes it impossible to get the order wrong when reigsering and unregistering sysctl tables. Autogenerating directories yields one unique entity that dentries can point to, retaining the current effective use of the dcache. Add struct ctl_dir as the type of these new autogenerated directories. The attached_by and attached_to fields in ctl_table_header are removed as they are no longer needed. The child field in ctl_table is no longer needed by the core of the sysctl code. ctl_table.child can be removed once all of the existing users have been updated. Benchmark before: make-dummies 0 999 -> 0.7s rmmod dummy -> 0.07s make-dummies 0 9999 -> 1m10s rmmod dummy -> 0.4s Benchmark after: make-dummies 0 999 -> 0.44s rmmod dummy -> 0.065s make-dummies 0 9999 -> 1m36s rmmod dummy -> 0.4s Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Add a root pointer to ctl_table_setEric W. Biederman
Add a ctl_table_root pointer to ctl_table set so it is easy to go from a ctl_table_set to a ctl_table_root. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Initial support for auto-unregistering sysctl tables.Eric W. Biederman
Add nreg to ctl_table_header. When nreg drops to 0 the ctl_table_header will be unregistered. Factor out drop_sysctl_table from unregister_sysctl_table, and add the logic for decrementing nreg. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Remove the now unused ctl_table parent field.Eric W. Biederman
While useful at one time for selinux and the sysctl sanity checks those users no longer use the parent field and we can safely remove it. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmil.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: register only tables of sysctl filesEric W. Biederman
Split the registration of a complex ctl_table array which may have arbitrary numbers of directories (->child != NULL) and tables of files into a series of simpler registrations that only register tables of files. Graphically: register('dir', { + file-a + file-b + subdir1 + file-c + subdir2 + file-d + file-e }) is transformed into: wrapper->subheaders[0] = register('dir', {file1-a, file1-b}) wrapper->subheaders[1] = register('dir/subdir1', {file-c}) wrapper->subheaders[2] = register('dir/subdir2', {file-d, file-e}) return wrapper This guarantees that __register_sysctl_table will only see a simple ctl_table array with all entries having (->child == NULL). Care was taken to pass the original simple ctl_table arrays to __register_sysctl_table whenever possible. This change is derived from a similar patch written by Lucrian Grijincu. Inspired-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Add support for register sysctl tables with a normal cstring path.Eric W. Biederman
Make __register_sysctl_table the core sysctl registration operation and make it take a char * string as path. Now that binary paths have been banished into the real of backwards compatibility in kernel/binary_sysctl.c where they can be safely ignored there is no longer a need to use struct ctl_path to represent path names when registering ctl_tables. Start the transition to using normal char * strings to represent pathnames when registering sysctl tables. Normal strings are easier to deal with both in the internal sysctl implementation and for programmers registering sysctl tables. __register_sysctl_paths is turned into a backwards compatibility wrapper that converts a ctl_path array into a normal char * string. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Remove the unnecessary sysctl_set parent concept.Eric W. Biederman
In sysctl_net register the two networking roots in the proper order. In register_sysctl walk the sysctl sets in the reverse order of the sysctl roots. Remove parent from ctl_table_set and setup_sysctl_set as it is no longer needed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Implement retire_sysctl_setEric W. Biederman
This adds a small helper retire_sysctl_set to remove the intimate knowledge about the how a sysctl_set is implemented from net/sysct_net.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Move the implementation into fs/proc/proc_sysctl.cEric W. Biederman
Move the core sysctl code from kernel/sysctl.c and kernel/sysctl_check.c into fs/proc/proc_sysctl.c. Currently sysctl maintenance is hampered by the sysctl implementation being split across 3 files with artificial layering between them. Consolidate the entire sysctl implementation into 1 file so that it is easier to see what is going on and hopefully allowing for simpler maintenance. For functions that are now only used in fs/proc/proc_sysctl.c remove their declarations from sysctl.h and make them static in fs/proc/proc_sysctl.c Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Register the base sysctl table like any other sysctl table.Eric W. Biederman
Simplify the code by treating the base sysctl table like any other sysctl table and register it with register_sysctl_table. To ensure this table is registered early enough to avoid problems call sysctl_init from proc_sys_init. Rename sysctl_net.c:sysctl_init() to net_sysctl_init() to avoid name conflicts now that kernel/sysctl.c:sysctl_init() is no longer static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-24sysctl: Consolidate !CONFIG_SYSCTL handlingEric W. Biederman
- In sysctl.h move functions only available if CONFIG_SYSCL is defined inside of #ifdef CONFIG_SYSCTL - Move the stub function definitions for !CONFIG_SYSCTL into sysctl.h and make them static inlines. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2012-01-03sysctl: use umode_t for table permissionsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-11-02sysctl: add support for poll()Lucas De Marchi
Adding support for poll() in sysctl fs allows userspace to receive notifications of changes in sysctl entries. This adds a infrastructure to allow files in sysctl fs to be pollable and implements it for hostname and domainname. [akpm@linux-foundation.org: s/declare/define/ for definitions] Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi> Cc: Greg KH <gregkh@suse.de> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-03ipv4: NET_IPV4_ROUTE_GC_INTERVAL removalVasily Averin
removing obsoleted sysctl, ip_rt_gc_interval variable no longer used since 2.6.38 Signed-off-by: Vasily Averin <vvs@sw.ru> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-09sysctl: the include of rcupdate.h is only needed in the kernelStephen Rothwell
Fixes this build-check error: include/linux/sysctl.h:28: included file 'linux/rcupdate.h' is not exported Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-08unfuck proc_sysctl ->d_compare()Al Viro
a) struct inode is not going to be freed under ->d_compare(); however, the thing PROC_I(inode)->sysctl points to just might. Fortunately, it's enough to make freeing that sucker delayed, provided that we don't step on its ->unregistering, clear the pointer to it in PROC_I(inode) before dropping the reference and check if it's NULL in ->d_compare(). b) I'm not sure that we *can* walk into NULL inode here (we recheck dentry->seq between verifying that it's still hashed / fetching dentry->d_inode and passing it to ->d_compare() and there's no negative hashed dentries in /proc/sys/*), but if we can walk into that, we really should not have ->d_compare() return 0 on it! Said that, I really suspect that this check can be simply killed. Nick? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-15sysctl: add proc_do_large_bitmapOctavian Purdila
The new function can be used to read/write large bitmaps via /proc. A comma separated range format is used for compact output and input (e.g. 1,3-4,10-10). Writing into the file will first reset the bitmap then update it based on the given input. Signed-off-by: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: WANG Cong <amwang@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16net neigh: Decouple per interface neighbour table controls from binary sysctlsEric W. Biederman
Stop computing the number of neighbour table settings we have by counting the number of binary sysctls. This behaviour was silly and meant that we could not add another neighbour table setting without also adding another binary sysctl. Don't pass the binary sysctl path for neighour table entries into neigh_sysctl_register. These parameters are no longer used and so are just dead code. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-16net ipv4: Decouple ipv4 interface parameters from binary sysctl numbersEric W. Biederman
Stop using the binary sysctl enumeartion in sysctl.h as an index into a per interface array. This leads to unnecessary binary sysctl number allocation, and a fragility in data structure and implementation because of unnecessary coupling. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2010-01-10Merge branch 'master' of ↵David S. Miller
master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/benet/be_cmds.h include/linux/sysctl.h
2010-01-07net: RFC3069, private VLAN proxy arp supportJesper Dangaard Brouer
This is to be used together with switch technologies, like RFC3069, that where the individual ports are not allowed to communicate with each other, but they are allowed to talk to the upstream router. As described in RFC 3069, it is possible to allow these hosts to communicate through the upstream router by proxy_arp'ing. This patch basically allow proxy arp replies back to the same interface (from which the ARP request/solicitation was received). Tunable per device via proc "proxy_arp_pvlan": /proc/sys/net/ipv4/conf/*/proxy_arp_pvlan This switch technology is known by different vendor names: - In RFC 3069 it is called VLAN Aggregation. - Cisco and Allied Telesyn call it Private VLAN. - Hewlett-Packard call it Source-Port filtering or port-isolation. - Ericsson call it MAC-Forced Forwarding (RFC Draft). Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-25net: restore ip source validationJamal Hadi Salim
when using policy routing and the skb mark: there are cases where a back path validation requires us to use a different routing table for src ip validation than the one used for mapping ingress dst ip. One such a case is transparent proxying where we pretend to be the destination system and therefore the local table is used for incoming packets but possibly a main table would be used on outbound. Make the default behavior to allow the above and if users need to turn on the symmetry via sysctl src_valid_mark Signed-off-by: Jamal Hadi Salim <hadi@cyberus.ca> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-12-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
2009-12-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1815 commits) mac80211: fix reorder buffer release iwmc3200wifi: Enable wimax core through module parameter iwmc3200wifi: Add wifi-wimax coexistence mode as a module parameter iwmc3200wifi: Coex table command does not expect a response iwmc3200wifi: Update wiwi priority table iwlwifi: driver version track kernel version iwlwifi: indicate uCode type when fail dump error/event log iwl3945: remove duplicated event logging code b43: fix two warnings ipw2100: fix rebooting hang with driver loaded cfg80211: indent regulatory messages with spaces iwmc3200wifi: fix NULL pointer dereference in pmkid update mac80211: Fix TX status reporting for injected data frames ath9k: enable 2GHz band only if the device supports it airo: Fix integer overflow warning rt2x00: Fix padding bug on L2PAD devices. WE: Fix set events not propagated b43legacy: avoid PPC fault during resume b43: avoid PPC fault during resume tcp: fix a timewait refcnt race ... Fix up conflicts due to sysctl cleanups (dead sysctl_check code and CTL_UNNUMBERED removed) in kernel/sysctl_check.c net/ipv4/sysctl_net_ipv4.c net/ipv6/addrconf.c net/sctp/sysctl.c
2009-12-04sysctl: add missing commentsThadeu Lima de Souza Cascardo
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-12-03ipv4 05/05: add sysctl to accept packets with local source addressesPatrick McHardy
commit 8ec1e0ebe26087bfc5c0394ada5feb5758014fc8 Author: Patrick McHardy <kaber@trash.net> Date: Thu Dec 3 12:16:35 2009 +0100 ipv4: add sysctl to accept packets with local source addresses Change fib_validate_source() to accept packets with a local source address when the "accept_local" sysctl is set for the incoming inet device. Combined with the previous patches, this allows to communicate between multiple local interfaces over the wire. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-18sysctl: Remove CTL_NONE and CTL_UNNUMBEREDEric W. Biederman
Now that the sysctl structures no longer have a ctl_name field there is no reason to retain the definitions for CTL_NONE and CTL_UNNUMBERED, or to explain their historic usage. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-18sysctl: kill dead ctl_handler definitions.Eric W. Biederman
When removing the sysctl strategy routines I overlooked their definitions in sysctl.h. So remove those unnecessary definitions now. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-12sysctl: Remove the last of the generic binary sysctl supportEric W. Biederman
Now that all of the users stopped using ctl_name and strategy it is safe to remove the fields from struct ctl_table, and it is safe to remove the stub strategy routines as well. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-11sysctl: Don't look at ctl_name and strategy in the generic codeEric W. Biederman
The ctl_name and strategy fields are unused, now that sys_sysctl is a compatibility wrapper around /proc/sys. No longer looking at them in the generic code is effectively what we are doing now and provides the guarantee that during further cleanups we can just remove references to those fields and everything will work ok. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-11-06sysctl: Make do_sysctl staticEric W. Biederman
Now that all of the architectures use compat_sys_sysctl do_sysctl can become static. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
2009-09-24sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan
It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-02-01net: add ARP notify option for devicesStephen Hemminger
This adds another inet device option to enable gratuitous ARP when device is brought up or address change. This is handy for clusters or virtualization. Signed-off-by: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-16sysctl: simplify ->strategyAlexey Dobriyan
name and nlen parameters passed to ->strategy hook are unused, remove them. In general ->strategy hook should know what it's doing, and don't do something tricky for which, say, pointer to original userspace array may be needed (name). Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> [ networking bits ] Cc: Ralf Baechle <ralf@linux-mips.org> Cc: David Howells <dhowells@redhat.com> Cc: Matt Mackall <mpm@selenic.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26[PATCH] sanitize proc_sysctlAl Viro
* keep references to ctl_table_head and ctl_table in /proc/sys inodes * grab the former during operations, use the latter for access to entry if that succeeds * have ->d_compare() check if table should be seen for one who does lookup; that allows us to avoid flipping inodes - if we have the same name resolve to different things, we'll just keep several dentries and ->d_compare() will reject the wrong ones. * have ->lookup() and ->readdir() scan the table of our inode first, then walk all ctl_table_header and scan ->attached_by for those that are attached to our directory. * implement ->getattr(). * get rid of insane amounts of tree-walking * get rid of the need to know dentry in ->permission() and of the contortions induced by that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] sysctl: keep track of tree relationshipsAl Viro
In a sense, that's the heart of the series. It's based on the following property of the trees we are actually asked to add: they can be split into stem that is already covered by registered trees and crown that is entirely new. IOW, if a/b and a/c/d are introduced by our tree, then a/c is also introduced by it. That allows to associate tree and table entry with each node in the union; while directory nodes might be covered by many trees, only one will cover the node by its crown. And that will allow much saner logics for /proc/sys in the next patches. This patch introduces the data structures needed to keep track of that. When adding a sysctl table, we find a "parent" one. Which is to say, find the deepest node on its stem that already is present in one of the tables from our table set or its ancestor sets. That table will be our parent and that node in it - attachment point. Add our table to list anchored in parent, have it refer the parent and contents of attachment point. Also remember where its crown lives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] allow delayed freeing of ctl_table_headerAl Viro
Refcount the sucker; instead of freeing it by the end of unregistration just drop the refcount and free only when it hits zero. Make sure that we _always_ make ->unregistering non-NULL in start_unregistering(). That allows anybody to get a reference to such puppy, preventing its freeing and reuse. It does *not* block unregistration. Anybody who holds such a reference can * try to grab a "use" reference (ctl_head_grab()); that will succeeds if and only if it hadn't entered unregistration yet. If it succeeds, we can use it in all normal ways until we release the "use" reference (with ctl_head_finish()). Note that this relies on having ->unregistering become non-NULL in all cases when one starts to unregister the sucker. * keep pointers to ctl_table entries; they *can* be freed if the entire thing is unregistered. However, if ctl_head_grab() succeeds, we know that unregistration had not happened (and will not happen until ctl_head_finish()) and such pointers can be used safely. IOW, now we can have inodes under /proc/sys keep references to ctl_table entries, protecting them with references to ctl_table_header and grabbing the latter for the duration of operations that require access to ctl_table. That won't cause deadlocks, since unregistration will not be stopped by mere keeping a reference to ctl_table_header. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] beginning of sysctl cleanup - ctl_table_setAl Viro
New object: set of sysctls [currently - root and per-net-ns]. Contains: pointer to parent set, list of tables and "should I see this set?" method (->is_seen(set)). Current lists of tables are subsumed by that; net-ns contains such a beast. ->lookup() for ctl_table_root returns pointer to ctl_table_set instead of that to ->list of that ctl_table_set. [folded compile fixes by rdd for configs without sysctl] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-29sysctl: add the ->permissions callback on the ctl_table_rootPavel Emelyanov
When reading from/writing to some table, a root, which this table came from, may affect this table's permissions, depending on who is working with the table. The core hunk is at the bottom of this patch. All the rest is just pushing the ctl_table_root argument up to the sysctl_perm() function. This will be mostly (only?) used in the net sysctls. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29sysctl: clean from unneeded extern and forward declarationsPavel Emelyanov
The do_sysctl_strategy isn't used outside kernel/sysctl.c, so this can be static and without a prototype in header. Besides, move this one and parse_table() above their callers and drop the forward declarations of the latter call. One more "besides" - fix two checkpatch warnings: space before a ( and an extra space at the end of a line. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: David S. Miller <davem@davemloft.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@sw.ru> Cc: Denis V. Lunev <den@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29include/linux/sysctl.h: remove empty #elseAdrian Bunk
Remove an empty #else. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05capabilities: introduce per-process capability bounding setSerge E. Hallyn
The capability bounding set is a set beyond which capabilities cannot grow. Currently cap_bset is per-system. It can be manipulated through sysctl, but only init can add capabilities. Root can remove capabilities. By default it includes all caps except CAP_SETPCAP. This patch makes the bounding set per-process when file capabilities are enabled. It is inherited at fork from parent. Noone can add elements, CAP_SETPCAP is required to remove them. One example use of this is to start a safer container. For instance, until device namespaces or per-container device whitelists are introduced, it is best to take CAP_MKNOD away from a container. The bounding set will not affect pP and pE immediately. It will only affect pP' and pE' after subsequent exec()s. It also does not affect pI, and exec() does not constrain pI'. So to really start a shell with no way of regain CAP_MKNOD, you would do prctl(PR_CAPBSET_DROP, CAP_MKNOD); cap_t cap = cap_get_proc(); cap_value_t caparray[1]; caparray[0] = CAP_MKNOD; cap_set_flag(cap, CAP_INHERITABLE, 1, caparray, CAP_DROP); cap_set_proc(cap); cap_free(cap); The following test program will get and set the bounding set (but not pI). For instance ./bset get (lists capabilities in bset) ./bset drop cap_net_raw (starts shell with new bset) (use capset, setuid binary, or binary with file capabilities to try to increase caps) ************************************************************ cap_bound.c ************************************************************ #include <sys/prctl.h> #include <linux/capability.h> #include <sys/types.h> #include <unistd.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #ifndef PR_CAPBSET_READ #define PR_CAPBSET_READ 23 #endif #ifndef PR_CAPBSET_DROP #define PR_CAPBSET_DROP 24 #endif int usage(char *me) { printf("Usage: %s get\n", me); printf(" %s drop <capability>\n", me); return 1; } #define numcaps 32 char *captable[numcaps] = { "cap_chown", "cap_dac_override", "cap_dac_read_search", "cap_fowner", "cap_fsetid", "cap_kill", "cap_setgid", "cap_setuid", "cap_setpcap", "cap_linux_immutable", "cap_net_bind_service", "cap_net_broadcast", "cap_net_admin", "cap_net_raw", "cap_ipc_lock", "cap_ipc_owner", "cap_sys_module", "cap_sys_rawio", "cap_sys_chroot", "cap_sys_ptrace", "cap_sys_pacct", "cap_sys_admin", "cap_sys_boot", "cap_sys_nice", "cap_sys_resource", "cap_sys_time", "cap_sys_tty_config", "cap_mknod", "cap_lease", "cap_audit_write", "cap_audit_control", "cap_setfcap" }; int getbcap(void) { int comma=0; unsigned long i; int ret; printf("i know of %d capabilities\n", numcaps); printf("capability bounding set:"); for (i=0; i<numcaps; i++) { ret = prctl(PR_CAPBSET_READ, i); if (ret < 0) perror("prctl"); else if (ret==1) printf("%s%s", (comma++) ? ", " : " ", captable[i]); } printf("\n"); return 0; } int capdrop(char *str) { unsigned long i; int found=0; for (i=0; i<numcaps; i++) { if (strcmp(captable[i], str) == 0) { found=1; break; } } if (!found) return 1; if (prctl(PR_CAPBSET_DROP, i)) { perror("prctl"); return 1; } return 0; } int main(int argc, char *argv[]) { if (argc<2) return usage(argv[0]); if (strcmp(argv[1], "get")==0) return getbcap(); if (strcmp(argv[1], "drop")!=0 || argc<3) return usage(argv[0]); if (capdrop(argv[2])) { printf("unknown capability\n"); return 1; } return execl("/bin/bash", "/bin/bash", NULL); } ************************************************************ [serue@us.ibm.com: fix typo] Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Signed-off-by: Andrew G. Morgan <morgan@kernel.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: James Morris <jmorris@namei.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Casey Schaufler <casey@schaufler-ca.com>a Signed-off-by: "Serge E. Hallyn" <serue@us.ibm.com> Tested-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-01-31[IPV4] route cache: Introduce rt_genid for smooth cache invalidationEric Dumazet
Current ip route cache implementation is not suited to large caches. We can consume a lot of CPU when cache must be invalidated, since we currently need to evict all cache entries, and this eviction is sometimes asynchronous. min_delay & max_delay can somewhat control this asynchronism behavior, but whole thing is a kludge, regularly triggering infamous soft lockup messages. When entries are still in use, this also consumes a lot of ram, filling dst_garbage.list. A better scheme is to use a generation identifier on each entry, so that cache invalidation can be performed by changing the table identifier, without having to scan all entries. No more delayed flushing, no more stalling when secret_interval expires. Invalidated entries will then be freed at GC time (controled by ip_rt_gc_timeout or stress), or when an invalidated entry is found in a chain when an insert is done. Thus we keep a normal equilibrium. This patch : - renames rt_hash_rnd to rt_genid (and makes it an atomic_t) - Adds a new rt_genid field to 'struct rtable' (filling a hole on 64bit) - Checks entry->rt_genid at appropriate places :