To not introduce more redundant code, helpers are added for
both "selinux", "dac", and "apparmor" backends.
Signed-off-by: NHan Cheng <hanc.fnst@cn.fujitsu.com>
Signed-off-by: NOsier Yang <jyang@redhat>

v2.5 - v3:
  * Splitted from 8/10 of v2.5
  * Don't forget the other backends (DAC, and apparmor)

These all existed before virfile.c was created, and for some reason
weren't moved.

This is mostly straightfoward, although the syntax rule prohibiting
write() had to be changed to have an exception for virfile.c instead
of virutil.c.

This movement pointed out that there is a function called
virBuildPath(), and another almost identical function called
virFileBuildPath(). They really should be a single function, which
I'll take care of as soon as I figure out what the arglist should look
like.

The source code base needs to be adapted as well. Some files
include virutil.h just for the string related functions (here,
the include is substituted to match the new file), some include
virutil.h without any need (here, the include is removed), and
some require both.

If virPCIDeviceGetVFIOGroupDev() failed,
virSecurity*(Set|Restore)HostdevLabel() would fail to free a
virPCIDevice that had been allocated.

These leaks were all introduced (by me) very recently, in commit
f0bd70a9.

This isn't strictly speaking a bugfix, but I realized I'd gotten a bit
too verbose when I chose the names for
VIR_DOMAIN_HOSTDEV_PCI_BACKEND_TYPE_*. This shortens them all a bit.

Legacy kvm style pci device assignment requires changes to the
labelling of several sysfs files for each device, but for vfio device
assignment, the only thing that needs to be relabelled/chowned is the
"group" device for the group that contains the device to be assigned.

There will soon be other items related to pci hostdevs that need to be
in the same part of the hostdevsubsys union as the pci address (which
is currently a single member called "pci". This patch replaces the
single member named pci with a struct named pci that contains a single
member named "addr".

Signed-off-by: NStefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: NCorey Bryant <coreyb@linux.vnet.ibm.com>
Tested-by: NCorey Bryant <coreyb@linux.vnet.ibm.com>

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.

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.)

Rename all the usbDeviceXXX and usbXXXDevice APIs to have a
fixed virUSBDevice name prefix

Rename all the pciDeviceXXX and pciXXXDevice APIs to have a
fixed virPCIDevice name prefix

When LXC labels USB devices during hotplug, it is running in
host context, so it needs to pass in a vroot path to the
container root.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

The libvirt coding standard is to use 'function(...args...)'
instead of 'function (...args...)'. A non-trivial number of
places did not follow this rule and are fixed in this patch.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Reported by Michal Privoznik.

* src/security/security_dac.c (virSecurityDACGenLabel): Use
correct format.

Fixes a build failure on cygwin:
cc1: warnings being treated as errors
security/security_dac.c: In function 'virSecurityDACSetProcessLabel':
security/security_dac.c:862:5: error: format '%u' expects type 'unsigned int', but argument 7 has type 'uid_t' [-Wformat]
security/security_dac.c:862:5: error: format '%u' expects type 'unsigned int', but argument 8 has type 'gid_t' [-Wformat]

* src/security/security_dac.c (virSecurityDACSetProcessLabel)
(virSecurityDACGenLabel): Use proper casts.

We used to walk the backing file chain at least twice per disk,
once to set up cgroup device whitelisting, and once to set up
security labeling.  Rather than walk the chain every iteration,
which possibly includes calls to fork() in order to open root-squashed
NFS files, we can exploit the cache of the previous patch.

* src/conf/domain_conf.h (virDomainDiskDefForeachPath): Alter
signature.
* src/conf/domain_conf.c (virDomainDiskDefForeachPath): Require caller
to supply backing chain via disk, if recursion is desired.
* src/security/security_dac.c
(virSecurityDACSetSecurityImageLabel): Adjust caller.
* src/security/security_selinux.c
(virSecuritySELinuxSetSecurityImageLabel): Likewise.
* src/security/virt-aa-helper.c (get_files): Likewise.
* src/qemu/qemu_cgroup.c (qemuSetupDiskCgroup)
(qemuTeardownDiskCgroup): Likewise.
(qemuSetupCgroup): Pre-populate chain.

BZ:https://bugzilla.redhat.com/show_bug.cgi?id=851981
When using macvtap, a character device gets first created by
kernel with name /dev/tapN, its selinux context is:
system_u:object_r:device_t:s0

Shortly, when udev gets notification when new file is created
in /dev, it will then jump in and relabel this file back to the
expected default context:
system_u:object_r:tun_tap_device_t:s0

There is a time gap happened.
Sometimes, it will have migration failed, AVC error message:
type=AVC msg=audit(1349858424.233:42507): avc:  denied  { read write } for
pid=19926 comm="qemu-kvm" path="/dev/tap33" dev=devtmpfs ino=131524
scontext=unconfined_u:system_r:svirt_t:s0:c598,c908
tcontext=system_u:object_r:device_t:s0 tclass=chr_file

This patch will label the tapfd device before qemu process starts:
system_u:object_r:tun_tap_device_t:MCS(MCS from seclabel->label)

All USB device lookup functions emit an error when they cannot find the
requested device. With this patch, their caller can choose if a missing
device is an error or normal condition.

The functions virGetUserID and virGetGroupID are now able to parse
user/group names and IDs in a similar way to coreutils' chown. So, user
and group parsing in security_dac can be simplified.

The DAC driver is missing parsing of group and user names for DAC labels
and currently just parses uid and gid. This patch extends it to support
names, so the following security label definition is now valid:

  <seclabel type='static' model='dac' relabel='yes'>
      <label>qemu:qemu</label>
      <imagelabel>qemu:qemu</imagelabel>
  </seclabel>

When it tries to parse an owner or a group, it first tries to resolve it as
a name, if it fails or it's an invalid user/group name then it tries to
parse it as an UID or GID. A leading '+' can also be used for both owner and
group to force it to be parsed as IDs, so the following example is also
valid:

  <seclabel type='static' model='dac' relabel='yes'>
      <label>+101:+101</label>
      <imagelabel>+101:+101</imagelabel>
  </seclabel>

This ensures that UID 101 and GUI 101 will be used instead of an user or
group named "101".

https://www.gnu.org/licenses/gpl-howto.html recommends that
the 'If not, see <url>.' phrase be a separate sentence.

* tests/securityselinuxhelper.c: Remove doubled line.
* tests/securityselinuxtest.c: Likewise.
* globally: s/;  If/.  If/

The DAC security driver silently ignored errors when parsing the DAC
label and used default values instead.

With a domain containing the following label definition:

<seclabel type='static' model='dac' relabel='yes'>
  <label>sdfklsdjlfjklsdjkl</label>
</seclabel>

the domain would start normaly but the disk images would be still owned
by root and no error was displayed.

This patch changes the behavior if the parsing of the label fails (note
that a not present label is not a failure and in this case the default
label should be used) the error isn't masked but is raised that causes
the domain start to fail with a descriptive error message:

virsh #  start tr
error: Failed to start domain tr
error: internal error invalid argument: failed to parse DAC seclabel
'sdfklsdjlfjklsdjkl' for domain 'tr'

I also changed the error code to "invalid argument" from "internal
error" and tweaked the various error messages to contain correct and
useful information.

* src/security/security_dac.c: remove useless dead code.
Signed-off-by: NAlex Jia <ajia@redhat.com>

As in the previous commit, images are also chowned to uninitialised
uid and gid if the label is not present.

When starting a machine the DAC security driver tries to set the UID and
GID of the newly spawned process. This worked as desired if the desired
label was set. When the label was missing a logical bug in
virSecurityDACGenLabel() caused that uninitialised values were used as
uid and gid for the new process.

With this patch, default values (from qemu driver configuration)
are used if the label is not found.

When no DAC "label" was requested for a domain the DAC manager tried to
strdup a NULL string causing a segfault.

The DAC security driver uses the virStrToLong_ui function to
parse the uid/gid out of the seclabel string. This works on
Linux where 'uid_t' is an unsigned int, but on Mingw32 it is
just an 'int'. This causes compiler warnings about signed/
unsigned int pointer mis-match.

To avoid this, use explicit 'unsigned int ouruid' local
vars to pass into virStrToLong_ui, and then simply assign
to the 'uid_t' type after parsing
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

These changes make the security drivers able to find and handle the
correct security label information when more than one label is
available. They also update the DAC driver to be used as an usual
security driver.
Signed-off-by: NMarcelo Cerri <mhcerri@linux.vnet.ibm.com>