Commit Graph

12309 Commits

Author SHA1 Message Date
Jim Fehlig
567779e51a libxl: Fix setting of disk backend
The libxl driver was setting the backend field of libxl_device_disk
structure to LIBXL_DISK_BACKEND_TAP when the driver element of disk
configuration was not specified.  This needlessly forces the use of
blktap driver, which may not be loaded in dom0

https://bugzilla.redhat.com/show_bug.cgi?id=912488

Ian Campbell suggested that LIBXL_DISK_BACKEND_UNKNOWN is a better
default in this case

https://www.redhat.com/archives/libvir-list/2013-February/msg01126.html
2013-02-20 14:52:10 -07:00
John Ferlan
2bff35d5bb Remove a couple of misplaced VIR_FREE 2013-02-20 12:43:00 -05:00
Michal Privoznik
0eeedf52e7 qemu: Run lzop with '--ignore-warn'
Currently, if lzop decompression binary produces a warning, it
doesn't exit with zero status but 2 instead. Terrifying, but
true. However, warnings may be ignored using '--ignore-warn'
command line argument.  Moreover, in which case, the exit status
will be zero.
2013-02-20 18:10:01 +01:00
Sergey Fionov
1d8193ee8a Fix memory leak in virNetClientIOWriteMessage
Commit 18937c3ae0 introduced the
memory leak when client->msg.fds is copied to thecall->msg
and then never freed.
2013-02-20 17:56:35 +01:00
Osier Yang
d0172d2b1b qemu: Remove the shared disk entry if the operation is ejecting or updating
For both AttachDevice and UpdateDevice APIs, if the disk device
is 'cdrom' or 'floppy', the operations could be ejecting, updating,
and inserting. For either ejecting or updating, the shared disk
entry of the original disk src has to be removed, because it's
not useful anymore.

And since the original disk def will be changed, new disk def passed
as argument will be free'ed in qemuDomainChangeEjectableMedia, so
we need to copy the orignal disk def before
qemuDomainChangeEjectableMedia, to use it for qemuRemoveSharedDisk.
2013-02-21 00:31:24 +08:00
Osier Yang
0db7ff59cc qemu: Move the shared disk adding and sgio setting prior to attaching
The disk def could be free'ed by qemuDomainChangeEjectableMedia,
which can thus cause crash if we reference the disk pointer. On
the other hand, we have to remove the added shared disk entry from
the table on error codepath.
2013-02-21 00:31:24 +08:00
Osier Yang
d0e4b76204 qemu: Update shared disk table when reconnecting qemu process 2013-02-21 00:31:24 +08:00
Osier Yang
a4504ac184 qemu: Record names of domain which uses the shared disk in hash table
The hash entry is changed from "ref" to {ref, @domains}. With this, the
caller can simply call qemuRemoveSharedDisk, without afraid of removing
the entry belongs to other domains. qemuProcessStart will obviously
benifit from it on error codepath (which calls qemuProcessStop to do
the cleanup).
2013-02-21 00:31:24 +08:00
Osier Yang
371df778eb qemu: Merge qemuCheckSharedDisk into qemuAddSharedDisk
Based on moving various checking into qemuAddSharedDisk, this
avoids the caller using it in wrong ways. Also this adds two
new checking for qemuCheckSharedDisk (disk device not 'lun'
and kernel doesn't support unpriv_sgio simply returns 0).
2013-02-21 00:31:24 +08:00
Osier Yang
dab878a861 qemu: Add checking in helpers for sgio setting
This moves the various checking into the helpers, to avoid the
callers missing the checking.
2013-02-21 00:31:24 +08:00
Eric Blake
6ea7b3e8d1 maint: enforce private symbol section sorting
Automating a sorting check is the only way to ensure we don't
regress.  Suggested by Dan Berrange.

* src/check-symsorting.pl (check_sorting): Add a parameter,
validate that groups are in order, and that files exist.
* src/Makefile.am (check-symsorting): Adjust caller.
* src/libvirt_private.syms: Fix typo.
* src/libvirt_linux.syms: Fix file name.
* src/libvirt_vmx.syms: Likewise.
* src/libvirt_xenxs.syms: Likewise.
* src/libvirt_sasl.syms: Likewise.
* src/libvirt_libssh2.syms: Likewise.
* src/libvirt_esx.syms: Mention file name.
* src/libvirt_openvz.syms: Likewise.
2013-02-20 08:27:03 -07:00
Jiri Denemark
69660042fb qemu: Do not ignore mandatory features in migration cookie
Due to "feature"/"features" nasty typo, any features marked as mandatory
by one side of a migration are silently considered optional by the other
side. The following is the code that formats mandatory features in
migration cookie:

    for (i = 0 ; i < QEMU_MIGRATION_COOKIE_FLAG_LAST ; i++) {
        if (mig->flagsMandatory & (1 << i))
            virBufferAsprintf(buf, "  <feature name='%s'/>\n",
                              qemuMigrationCookieFlagTypeToString(i));
    }
2013-02-20 15:24:01 +01:00
Ján Tomko
bc28e56b35 qemu: switch PCI address alocation to use virDevicePCIAddress
Some functions were using virDomainDeviceInfo where virDevicePCIAddress
would suffice. Some were only using integers for slots and functions,
assuming the bus numbers are always 0.

Switch from virDomainDeviceInfoPtr to virDevicePCIAddressPtr:
qemuPCIAddressAsString
qemuDomainPCIAddressCheckSlot
qemuDomainPCIAddressReserveAddr
qemuDomainPCIAddressReleaseAddr

Switch from int slot to virDevicePCIAddressPtr:
qemuDomainPCIAddressReserveSlot
qemuDomainPCIAddressReleaseSlot
qemuDomainPCIAddressGetNextSlot

Deleted functions (they would take the same parameters
as ReserveAddr/ReleaseAddr do now.)
qemuDomainPCIAddressReserveFunction
qemuDomainPCIAddressReleaseFunction
2013-02-20 13:57:59 +01:00
Guannan Ren
dd71fa110a virsh: distinguish errors between missing argument and wrong option
Specifying ':' to suppress the error messages printed by getopt().
Then, distinguish the two types of errors.

Before:
 # virsh -c
   virsh: option requires an argument -- 'c'
   error: unsupported option '-?'. See --help.

After:
 # virsh -c
   error: option '-c' requires an argument

 # virsh -x
   error: unsupported option '-x'. See --help.
2013-02-20 10:14:25 +08:00
Eric Blake
f190a636e5 maint: sort private syms to reflect recent header renames
Purely mechanical (roughly, s/\n/~/; s/~~/\n/; sort by line;
s/~/\n/)

* src/libvirt_private.syms: Sort sections by header file name.
2013-02-19 14:59:05 -07:00
Eric Blake
8a256f3cb4 maint: fix header file owners of private symbols
Recent renames were not reflected into the comments of
libvirt_private.syms; furthermore, since we mix private headers from
several directories into this file, knowing where the file lives
can be helpful.

* src/libvirt_private.sym: Reflect recent names.
2013-02-19 14:59:05 -07:00
Natanael Copa
bac8b2ca09 net: use structs for address and port ranges
We pass over the address/port start/end values many times so we put
them in structs.

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine Stump <laine@laine.org>
2013-02-19 14:42:18 -05:00
Natanael Copa
1716e7a6c5 net: add support for specifying port range for forward mode nat
Let users set the port range to be used for forward mode NAT:

...
  <forward mode='nat'>
    <nat>
      <port start='1024' end='65535'/>
    </nat>
  </forward>
...

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine Stump <laine@laine.org>
2013-02-19 14:42:18 -05:00
Natanael Copa
905629f47e net: support set public ip range for forward mode nat
Support setting which public ip to use for NAT via attribute
address in subelement <nat> in <forward>:

...
  <forward mode='nat'>
      <address start='1.2.3.4' end='1.2.3.10'/>
  </forward>
...

This will construct an iptables line using:

  '-j SNAT --to-source <start>-<end>'

instead of:

  '-j MASQUERADE'

Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Laine Stump <laine@laine.org>
2013-02-19 14:42:18 -05:00
Jiri Denemark
5d6f636764 qemu: Use atomic ops for driver->nactive 2013-02-19 19:11:23 +01:00
Jiri Denemark
921af42980 rpc: Avoid deadlock when closing client connection
We need to drop the server lock before calling virObjectUnlock(client)
since in case we had the last reference to the client, its dispose
callback would be called and that could possibly try to lock the server
and cause a deadlock. This is exactly what happens when there is only
one QEMU domain running and it is marked to be autodestroyed when the
connection dies. This results in qemuProcessAutoDestroy ->
qemuProcessStop -> virNetServerRemoveShutdownInhibition call sequence,
where the last function locks the server.
2013-02-19 10:52:37 +01:00
Jiri Denemark
ee1d6d91d1 Avoid resetting errors in virTypedParamsFree
The function does not report any errors so there should be no need too
reset an existing error first. Moreover, virTypedParamsFree is mostly
called in cleanup phase where it has the potential to reset any useful
reported earlier.
2013-02-19 10:52:37 +01:00
Jiri Denemark
ada9e157a2 virsh: Always print capacity unit
It doesn't make sense to print the unit (B) only with Ki, Mi, ...
prefixes. Even those poor bytes under 1 KiB are still bytes :-)
2013-02-19 10:52:37 +01:00
Eric Blake
e086deda3c build: force correct gcc syntax for attribute_nonnull
Gcc lets you do:

int ATTRIBUTE_NONNULL(1) foo(void *param);
int foo(void *param) ATTRIBUTE_NONNULL(1);
int ATTRIBUTE_NONNULL(1) foo(void *param) { ... }

but chokes on:

int foo(void *param) ATTRIBUTE_NONNULL(1) { ... }

However, since commit eefb881, we have intentionally been disabling
ATTRIBUTE_NONNULL because of lame gcc handling of the attribute (that
is, gcc doesn't do decent warning reporting, then compiles code that
mysteriously fails if you break the contract of the attribute, which
is surprisingly easy to do), leaving it on only for Coverity (which
does a much better job of improved static analysis when the attribute
is present).

But completely eliding the macro makes it too easy to write code that
uses the fourth syntax option, if you aren't using Coverity.  So this
patch forces us to avoid syntax errors, even when not using the
attribute under gcc.  It also documents WHY we disable the warning
under gcc, rather than forcing you to find the commit log.

* src/internal.h (ATTRIBUTE_NONNULL): Expand to empty attribute,
rather than nothing, when on gcc.
2013-02-18 14:17:40 -07:00
Guido Günther
272be1a840 qemu: pass "-1" as uid/gid for unprivileged qemu
so we don't try to change uid/git to 0 when probing capabilities.
2013-02-18 12:08:38 -06:00
Doug Goldstein
41046256fe Add capabilities bit for -no-kvm-pit-reinjection
The conversion to qemuCaps dropped the ability with qemu{,-kvm} 1.2 and
newer to set the lost tick policy for the PIT. While the
-no-kvm-pit-reinjection option is depreacated, it is still supported at
least through 1.4, it is better to not lose the functionality.
2013-02-18 12:03:52 -06:00
Doug Goldstein
5eb621fcb3 interface: fix udev backend use after free
udevIfaceListAllInterface() used the udev_device after it had its ref
count decremented which results in a use after free issue.
2013-02-18 08:59:23 -06:00
Doug Goldstein
24cf110e48 Add autogenerated lxc_protocol.[ch] to gitignore
/src/lxc/lxc_protocol.[ch] is autogenerated so add it to .gitignore
2013-02-18 08:57:57 -06:00
John Ferlan
676688b69b security: Remove unnecessary checks for mgr == NULL
Coverity found the DACGenLabel was checking for mgr == NULL after a
possible dereference; however, in order to get into the function the
virSecurityManagerGenLabel would have already dereferenced sec_managers[i]
so the check was unnecessary. Same check is made in SELinuxGenSecurityLabel.
2013-02-16 07:44:35 -05:00
John Ferlan
1d816219eb virsh: Resolve possible NULL dereference
Coverity found that commit '41b5e845' had a possible NULL dereference on
arg->data processing
2013-02-16 07:44:35 -05:00
John Ferlan
277aaeeebf vircommand: Remove unnecessary sa_assert
Changes from commit '3178df9a' removed the need for the sa_assert(infd).
2013-02-16 07:44:35 -05:00
John Ferlan
11a1181260 commandtest: Resolve some coverity resource leaks 2013-02-16 07:44:35 -05:00
John Ferlan
e2f1fc5220 drivermodule: Ignore coverity warning about leaked_storage 2013-02-16 07:44:34 -05:00
Stefan Berger
b7d00de2bd Fix libvirt upgrade path when nwfilter is used
Between revision 65fb9d49 and before this patch, an upgrade of libvirt while
VMs are running and instantiating iptables filtering rules due to nwfilter
rules, may leave stray iptables rules behind when shutting VMs down.
Left-over iptables rules may look like this:

Chain FP-vnet0 (1 references)
target     prot opt source               destination         
DROP       tcp  --  0.0.0.0/0            0.0.0.0/0            tcp spt:122
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           

[...]

Chain libvirt-out (1 references)
target     prot opt source               destination         
FO-vnet0   all  --  0.0.0.0/0            0.0.0.0/0           [goto]  PHYSDEV match --physdev-out vnet0



The reason is that the recent nwfilter code only removed filtering rules in
the libvirt-out chain that contain the --physdev-is-bridged parameter.
Older rules didn't match and were not removed.

Note that the user-defined chain FO-vnet0 could not be removed due to the
reference from the rule in libvirt-out.

Often the work around may be done through

service iptables restart
kill -SIGHUP $(pidof libvirtd)

This patch now also removes older libvirt versions' iptables rules.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
2013-02-15 21:33:37 -05:00
Eric Blake
a18452d0d2 storage: test backing chain traversal
Testing our backing chain handling will make it much easier to
ensure that we avoid issues in the future.  If only I had written
this test before I first caused several regressions...

* tests/virstoragetest.c: New test.
* tests/Makefile.am (test_programs): Build it.
* .gitignore: Ignore new files.
2013-02-15 16:07:01 -07:00
Eric Blake
d1333dd0fb storage: don't follow backing chain symlinks too eagerly
If you have a qcow2 file /path1/to/file pointed to by symlink
/path2/symlink, and pass qemu /path2/symlink, then qemu treats
a relative backing file in the qcow2 metadata as being relative
to /path2, not /path1/to.  Yes, this means that it is possible
to create a qcow2 file where the choice of WHICH directory and
symlink you access its contents from will then determine WHICH
backing file (if any) you actually find; the results can be
rather screwy, but we have to match what qemu does.

Libvirt and qemu default to creating absolute backing file
names, so most users don't hit this.  But at least VDSM uses
symlinks and relative backing names alongside the
--reuse-external flags to libvirt snapshot operations, with the
result that libvirt was failing to follow the intended chain of
backing files, and then backing files were not granted the
necessary sVirt permissions to be opened by qemu.

See https://bugzilla.redhat.com/show_bug.cgi?id=903248 for
more gory details.  This fixes a regression introduced in
commit 8250783.

I tested this patch by creating the following chain:

ls /home/eblake/Downloads/Fedora.iso # raw file for base
cd /var/lib/libvirt/images
qemu-img create -f qcow2 \
  -obacking_file=/home/eblake/Downloads/Fedora.iso,backing_fmt=raw one
mkdir sub
cd sub
ln -s ../one onelink
qemu-img create -f qcow2 \
  -obacking_file=../sub/onelink,backing_fmt=qcow2 two
mv two ..
ln -s ../two twolink
qemu-img create -f qcow2 \
  -obacking_file=../sub/twolink,backing_fmt=qcow2 three
mv three ..
ln -s ../three threelink

then pointing my domain at /var/lib/libvirt/images/sub/threelink.
Prior to this patch, I got complaints about missing backing
files; afterwards, I was able to verify that the backing chain
(and hence DAC and SELinux relabels) of the entire chain worked.

* src/util/virstoragefile.h (_virStorageFileMetadata): Add
directory member.
* src/util/virstoragefile.c (absolutePathFromBaseFile): Drop,
replaced by...
(virFindBackingFile): ...better function.
(virStorageFileGetMetadataInternal): Add an argument.
(virStorageFileGetMetadataFromFD, virStorageFileChainLookup)
(virStorageFileGetMetadata): Update callers.
2013-02-15 16:07:01 -07:00
Eric Blake
2485f92153 storage: refactor metadata lookup
Prior to this patch, we had the callchains:
external users
  \-> virStorageFileGetMetadataFromFD
      \-> virStorageFileGetMetadataFromBuf
virStorageFileGetMetadataRecurse
  \-> virStorageFileGetMetadataFromFD
      \-> virStorageFileGetMetadataFromBuf

However, a future patch wants to add an additional parameter to
the bottom of the chain, for use by virStorageFileGetMetadataRecurse,
without affecting existing external callers.  Since there is only a
single caller of the internal function, we can repurpose it to fit
our needs, with this patch giving us:

external users
  \-> virStorageFileGetMetadataFromFD
      \-> virStorageFileGetMetadataInternal
virStorageFileGetMetadataRecurse /
  \-> virStorageFileGetMetadataInternal

* src/util/virstoragefile.c (virStorageFileGetMetadataFromFD):
Move most of the guts...
(virStorageFileGetMetadataFromBuf): ...here, and rename...
(virStorageFileGetMetadataInternal): ...to this.
(virStorageFileGetMetadataRecurse): Use internal helper.
2013-02-15 16:07:00 -07:00
Eric Blake
b7df4f92d6 storage: prepare for refactoring
virStorageFileGetMetadataFromFD is the only caller of
virStorageFileGetMetadataFromBuf; and it doesn't care about the
difference between a return of 0 (total success) or 1
(metadata was inconsistent, but pointer was populated as best
as possible); only about a return of -1 (could not read metadata
or out of memory).  Changing the return type, and normalizing
the variable names used, will make merging the functions easier
in the next commit.

* src/util/virstoragefile.c (virStorageFileGetMetadataFromBuf):
Change return value, and rename some variables.
(virStorageFileGetMetadataFromFD): Rename some variables.
2013-02-15 16:07:00 -07:00
Eric Blake
5e4946d4d9 storage: rearrange functions
No semantic change; done so the next patch doesn't need a forward
declaration of a static function.

* src/util/virstoragefile.c (virStorageFileProbeFormatFromBuf):
Hoist earlier.
2013-02-15 16:07:00 -07:00
Eric Blake
c51c3e45d5 build: more mingw fixes
More mingw build failures:

  CCLD     libvirt-lxc.la
/usr/lib64/gcc/i686-w64-mingw32/4.7.2/../../../../i686-w64-mingw32/bin/ld: cannot find libvirt_lxc.def: No such file or directory

  CC       virportallocatortest-virportallocatortest.o
../../tests/virportallocatortest.c: In function 'main':
../../tests/virportallocatortest.c:195:1: error: implicit declaration of function 'setenv' [-Werror=implicit-function-declaration]

* src/Makefile.am (GENERATED_SYM_FILES): Also generate
libvirt_lxc.def.
* bootstrap.conf (gnulib_modules): Import setenv.
2013-02-15 15:45:52 -07:00
Eric Blake
660db5bf72 build: fix mingw build
Commits 2025356 and ba72cb12 introduced typos.

* src/util/virpci.c (virPCIIsVirtualFunction) [!__linux__]: Fix
function name.
* src/util/virutil.c (virGetDeviceID): Fix attribute spelling.
2013-02-15 15:05:25 -07:00
Eric Blake
ec2cc0f860 build: fix vircommand build on mingw
CC       libvirt_util_la-vircommand.lo
../../src/util/vircommand.c:2358:1: error: 'virCommandHandshakeChild' defined but not used [-Werror=unused-function]

The function is only implemented inside #ifndef WIN32.

* src/util/vircommand.c (virCommandHandshakeChild): Hoist earlier,
so that win32 build doesn't hit an unused forward declaration.
2013-02-15 13:16:46 -07:00
Eric Blake
ec8a2d0327 regex: gnulib guarantees that we have regex support
No need to use HAVE_REGEX_H - our use of gnulib guarantees that
the header exists and works, regardless of platform.  Similarly,
we can unconditionally assume a compiling <sys/wait.h> (although
the mingw version of this header is not full-featured).

* src/storage/storage_backend.c: Drop useless conditional.
* tests/testutils.c: Likewise.
2013-02-15 13:01:23 -07:00
Jiri Denemark
2e5d7798df vbox: Don't overwrite errors returned by virDomainDeviceDefParse 2013-02-14 09:05:36 +01:00
Laine Stump
7a2e845a86 util: maintain caps when running command with uid != 0
virCommand was previously calling virSetUIDGID() to change the uid and
gid of the child process, then separately calling
virSetCapabilities(). This did not work if the desired uid was != 0,
since a setuid to anything other than 0 normally clears all
capabilities bits.

The solution is to use the new virSetUIDGIDWithCaps(), sending it the
uid, gid, and capabilities bits. This will get the new process setup
properly.

Since the static functions virSetCapabilities() and
virClearCapabilities are no longer called, they have been removed.

NOTE: When combined with "filecap $path-to-qemu sys_rawio", this patch
will make CAP_SYS_RAWIO (which is required for passthrough of generic
scsi commands to a guest - see commits e8daeeb, 177db08, 397e6a7, and
74e0349) be retained by qemu when necessary. Apparently that
capability has been broken for non-root qemu ever since it was
originally added.
2013-02-13 16:11:16 -05:00
Laine Stump
e11451f42e util: virSetUIDGIDWithCaps - change uid while keeping caps
Normally when a process' uid is changed to non-0, all the capabilities
bits are cleared, even those explicitly set with calls to
capng_update()/capng_apply() made immediately before setuid. And
*after* the process' uid has been changed, it no longer has the
necessary privileges to add capabilities back to the process.

In order to set a non-0 uid while still maintaining any capabilities
bits, it is necessary to either call capng_change_id() (which
unfortunately doesn't currently call initgroups to setup auxiliary
group membership), or to perform the small amount of calisthenics
contained in the new utility function virSetUIDGIDWithCaps().

Another very important difference between the capabilities
setting/clearing in virSetUIDGIDWithCaps() and virCommand's
virSetCapabilities() (which it will replace in the next patch) is that
the new function properly clears the capabilities bounding set, so it
will not be possible for a child process to set any new
capabilities.

A short description of what is done by virSetUIDGIDWithCaps():

1) clear all capabilities then set all those desired by the caller (in
capBits) plus CAP_SETGID, CAP_SETUID, and CAP_SETPCAP (which is needed
to change the capabilities bounding set).

2) call prctl(), telling it that we want to maintain current
capabilities across an upcoming setuid().

3) switch to the new uid/gid

4) again call prctl(), telling it we will no longer want capabilities
maintained if this process does another setuid().

5) clear the capabilities that we added to allow us to
setuid/setgid/change the bounding set (unless they were also requested
by the caller via the virCommand API).

Because the modification/maintaining of capabilities is intermingled
with setting the uid, this is necessarily done in a single function,
rather than having two independent functions.

Note that, due to the way that effective capabilities are computed (at
time of execve) for a process that has uid != 0, the *file*
capabilities of the binary being executed must also have the desired
capabilities bit(s) set (see "man 7 capabilities"). This can be done
with the "filecap" command. (e.g. "filecap /usr/bin/qemu-kvm sys_rawio").
2013-02-13 16:11:16 -05:00
Laine Stump
c0e3e685cd util: drop capabilities immediately after changing uid/gid of child
This is an interim measure to make sure everything still works in this
order. The next step will be to perform capabilities drop and
setuid/gid as a single operation (which is the only way to keep any
capabilities when switching to a non-root uid).
2013-02-13 16:11:16 -05:00
Laine Stump
0345c7281b qemu: let virCommand set child process security labels/uid/gid
The qemu driver had been calling virSecurityManagerSetProcessLabel()
from a "pre-exec hook" function that is run after the child is forked,
but before exec'ing qemu. This is problematic because the uid and gid
of the child are set by the security driver, but capabilities are
dropped by virCommand - such separation doesn't work; the two
operations must be done together or the capabilities do not transfer
properly to the child process.

This patch switches to using virSecurityManagerSetChildProcessLabel(),
which is called prior to virCommandRun() (rather than being called
*during* virCommandrun() by the hook function), and doesn't set the
UID/GID/security label directly, but instead merely informs virCommand
what it should set them all to when the time is appropriate.

This lets virCommand choose to do the uid/gid and caps dropping all at
the same time if it wants (it does *want* to, but isn't doing so yet;
that's for an upcoming patch).
2013-02-13 16:11:16 -05:00
Laine Stump
7bf1aa0b9b security: add new virSecurityManagerSetChildProcessLabel API
The existing virSecurityManagerSetProcessLabel() API is designed so
that it must be called after forking the child process, but before
exec'ing the child. Due to the way the virCommand API works, that
means it needs to be put in a "hook" function that virCommand is told
to call out to at that time.

Setting the child process label is a basic enough need when executing
any process that virCommand should have a method of doing that. But
virCommand must be told what label to set, and only the security
driver knows the answer to that question.

The new virSecurityManagerSet*Child*ProcessLabel() API is the way to
transfer the knowledge about what label to set from the security
driver to the virCommand object. It is given a virCommandPtr, and each
security driver calls the appropriate virCommand* API to tell
virCommand what to do between fork and exec.

1) in the case of the DAC security driver, it calls
virCommandSetUID/GID() to set a uid and gid that must be set for the
child process.

2) for the SELinux security driver, it calls
virCommandSetSELinuxLabel() to save a copy of the char* that will be
sent to setexeccon_raw() *after forking the child process*.

3) for the AppArmor security drivers, it calls
virCommandSetAppArmorProfile() to save a copy of the char* that will
be sent to aa_change_profile() *after forking the child process*.

With this new API in place, we will be able to remove
virSecurityManagerSetProcessLabel() from any virCommand pre-exec
hooks.

(Unfortunately, the LXC driver uses clone() rather than virCommand, so
it can't take advantage of this new security driver API, meaning that
we need to keep around the older virSecurityManagerSetProcessLabel(),
at least for now.)
2013-02-13 16:11:16 -05:00
Laine Stump
6c3f3d0d89 util: add security label setting to virCommand
virCommand gets two new APIs: virCommandSetSELinuxLabel() and
virCommandSetAppArmorProfile(), which both save a copy of a
null-terminated string in the virCommand. During virCommandRun, if the
string is non-NULL and we've been compiled with AppArmor and/or
SELinux security driver support, the appropriate security library
function is called for the child process, using the string that was
previously set. In the case of SELinux, setexeccon_raw() is called,
and for AppArmor, aa_change_profile() is called.

This functionality has been added so that users of virCommand can use
the upcoming virSecurityManagerSetChildProcessLabel() prior to running
a child process, rather than needing to setup a hook function to be
called (and in turn call virSecurityManagerSetProcessLabel()) *during*
the setup of the child process.
2013-02-13 16:11:15 -05:00