- 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
- 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>
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>
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>
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>
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>
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>
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>
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>
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>
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>
* 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
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>
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>
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>
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>
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>
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>
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>
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>
* 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>
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>
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>
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>
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>
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>
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>
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 :
Eric W. Biederman