There was a mess in the way how we store unlimited value for memory
limits and how we handled values provided by user. Internally there
were two possible ways how to store unlimited value: as 0 value or as
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED. Because we chose to store memory
limits as unsigned long long, we cannot use -1 to represent unlimited.
It's much easier for us to say that everything greater than
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED means unlimited and leave 0 as valid
value despite that it makes no sense to set limit to 0.
Remove unnecessary function virCompareLimitUlong. The update of test
is to prevent the 0 to be miss-used as unlimited in future.
Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1146539
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
The first one is to truncate the memory limit to
VIR_DOMAIN_MEMORY_PARAM_UNLIMITED if the value is greater and the second
one is to decide whether the memory limit is set or not, unlimited means
that it's not set.
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Some code paths have special logic depending on the page size
reported by sysconf, which in turn affects the test results.
We must mock this so tests always have a consistent page size.
Since not only systemd can do this (we'll be doing it as well few
patches later), change 'systemd' to 'caller' and fix LISTEN_FDS to
LISTEN_PID where applicable.
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
Introduce a new function to parse the provided scsi_host parent address
and unique_id value in order to find the /sys/class/scsi_host directory
which will allow a stable SCSI host address
Add a test to scsihosttest to lookup the host# name by using the PCI address
and unique_id value
Introduce a new function to read the current scsi_host entry and return
the value found in the 'unique_id' file.
Add a 'scsihosttest' test (similar to the fchosttest, but incorporating some
of the concepts of the mocked pci test library) in order to read the
unique_id file like would be found in the /sys/class/scsi_host tree.
SO_REUSEADDR on Windows is actually akin to SO_REUSEPORT
on Linux/BSD. ie it allows 2 apps to listen to the same
port at once. Thus we must not set it on Win32 platforms
See http://msdn.microsoft.com/en-us/library/windows/desktop/ms740621.aspx
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The future QEMU capabilities cache needs to be able to invalidate
itself if the libvirtd binary or any loadable modules are changed
on disk. Record the 'ctime' value for these binaries and provide
helper APIs to query it. This approach assumes that if libvirt.so
is changed, then libvirtd will also change, which should usually
be the case with libtool's wrapper scripts that cause libvirtd to
get re-linked
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
On my Fedora 20 box with mingw cross-compiler, the build failed with:
../../src/rpc/virnetclient.c: In function 'virNetClientSetTLSSession':
../../src/rpc/virnetclient.c:745:14: error: unused variable 'oldmask' [-Werror=unused-variable]
sigset_t oldmask, blockedsigs;
^
I traced it to the fact that mingw64-winpthreads installs a header
that does #define pthread_sigmask(...) 0, which means any argument
only ever passed to pthread_sigmask is reported as unused. This
patch works around the compilation failure, with behavior no worse
than what mingw already gives us regarding the function being a
no-op.
* configure.ac (pthread_sigmask): Probe for broken mingw macro.
* src/util/virutil.h (pthread_sigmask): Rewrite to something that
avoids unused variables.
Signed-off-by: Eric Blake <eblake@redhat.com>
We already have stubs for getuid, geteuid, getgid but
not for getegid. Something in gnulib already does a
check for it during configure, so we already have the
HAVE_GETEGID macro defined.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Care must be taken accessing env variables when running
setuid. Introduce a virGetEnvAllowSUID for env vars which
are safe to use in a setuid environment, and another
virGetEnvBlockSUID for vars which are not safe. Also add
a virIsSUID helper method for any other non-env var code
to use.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
The helper function virCompareLimitUlong compares limit values,
where value of 0 is equal to unlimited. If the latter parameter is 0,
it should return -1 instead of 1, hence the user can only set hard_limit when
swap_hard_limit currently is unlimited.
Worse, all callers pass 2 64-bit values, but on 32-bit platforms,
the second argument was silently truncated to 32 bits, which
could lead to incorrect computations.
Signed-off-by: Bing Bu Cao <mars@linux.vnet.ibm.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
This function is needed for virt-login-shell. Also modify virGirUserDirectory
to use the new function, to simplify the code.
Signed-off-by: Eric Blake <eblake@redhat.com>
Parsing 'user:group' is useful even outside the DAC security driver,
so expose the most abstract function which has no DAC security driver
bits in itself.
https://bugzilla.redhat.com/show_bug.cgi?id=964358
POSIX states that multi-threaded apps should not use functions
that are not async-signal-safe between fork and exec, yet we
were using getpwuid_r and initgroups. Although rare, it is
possible to hit deadlock in the child, when it tries to grab
a mutex that was already held by another thread in the parent.
I actually hit this deadlock when testing multiple domains
being started in parallel with a command hook, with the following
backtrace in the child:
Thread 1 (Thread 0x7fd56bbf2700 (LWP 3212)):
#0 __lll_lock_wait ()
at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:136
#1 0x00007fd5761e7388 in _L_lock_854 () from /lib64/libpthread.so.0
#2 0x00007fd5761e7257 in __pthread_mutex_lock (mutex=0x7fd56be00360)
at pthread_mutex_lock.c:61
#3 0x00007fd56bbf9fc5 in _nss_files_getpwuid_r (uid=0, result=0x7fd56bbf0c70,
buffer=0x7fd55c2a65f0 "", buflen=1024, errnop=0x7fd56bbf25b8)
at nss_files/files-pwd.c:40
#4 0x00007fd575aeff1d in __getpwuid_r (uid=0, resbuf=0x7fd56bbf0c70,
buffer=0x7fd55c2a65f0 "", buflen=1024, result=0x7fd56bbf0cb0)
at ../nss/getXXbyYY_r.c:253
#5 0x00007fd578aebafc in virSetUIDGID (uid=0, gid=0) at util/virutil.c:1031
#6 0x00007fd578aebf43 in virSetUIDGIDWithCaps (uid=0, gid=0, capBits=0,
clearExistingCaps=true) at util/virutil.c:1388
#7 0x00007fd578a9a20b in virExec (cmd=0x7fd55c231f10) at util/vircommand.c:654
#8 0x00007fd578a9dfa2 in virCommandRunAsync (cmd=0x7fd55c231f10, pid=0x0)
at util/vircommand.c:2247
#9 0x00007fd578a9d74e in virCommandRun (cmd=0x7fd55c231f10, exitstatus=0x0)
at util/vircommand.c:2100
#10 0x00007fd56326fde5 in qemuProcessStart (conn=0x7fd53c000df0,
driver=0x7fd55c0dc4f0, vm=0x7fd54800b100, migrateFrom=0x0, stdin_fd=-1,
stdin_path=0x0, snapshot=0x0, vmop=VIR_NETDEV_VPORT_PROFILE_OP_CREATE,
flags=1) at qemu/qemu_process.c:3694
...
The solution is to split the work of getpwuid_r/initgroups into the
unsafe portions (getgrouplist, called pre-fork) and safe portions
(setgroups, called post-fork).
* src/util/virutil.h (virSetUIDGID, virSetUIDGIDWithCaps): Adjust
signature.
* src/util/virutil.c (virSetUIDGID): Add parameters.
(virSetUIDGIDWithCaps): Adjust clients.
* src/util/vircommand.c (virExec): Likewise.
* src/util/virfile.c (virFileAccessibleAs, virFileOpenForked)
(virDirCreate): Likewise.
* src/security/security_dac.c (virSecurityDACSetProcessLabel):
Likewise.
* src/lxc/lxc_container.c (lxcContainerSetID): Likewise.
* configure.ac (AC_CHECK_FUNCS_ONCE): Check for setgroups, not
initgroups.
Signed-off-by: Eric Blake <eblake@redhat.com>
Since neither getpwuid_r() nor initgroups() are safe to call in
between fork and exec (they obtain a mutex, but if some other
thread in the parent also held the mutex at the time of the fork,
the child will deadlock), we have to split out the functionality
that is unsafe. At least glibc's initgroups() uses getgrouplist
under the hood, so the ideal split is to expose getgrouplist for
use before a fork. Gnulib already gives us a nice wrapper via
mgetgroups; we wrap it once more to look up by uid instead of name.
* bootstrap.conf (gnulib_modules): Add mgetgroups.
* src/util/virutil.h (virGetGroupList): New declaration.
* src/util/virutil.c (virGetGroupList): New function.
* src/libvirt_private.syms (virutil.h): Export it.
Signed-off-by: Eric Blake <eblake@redhat.com>
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.
Currently the virGetHostname() API has a bogus virConnectPtr
parameter. This is because virtualization drivers directly
reference this API in their virDriverPtr tables, tieing its
API design to the public virConnectGetHostname API design.
This also causes problems for access control checks since
these must only be done for invocations from the public
API, not internal invocation.
Remove the bogus virConnectPtr parameter, and make each
hypervisor driver provide a dedicated function for the
driver API impl. This will allow access control checks
to be easily inserted later.
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
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.
Refactoring done in 19c6ad9ac7 didn't
correctly take into account the order cgroup limit modification needs to
be done in. This resulted into errors when decreasing the limits.
The operations need to take place in this order:
decrease hard limit
change swap hard limit
or
change swap hard limit
increase hard limit
This patch also fixes the check if the hard_limit is less than
swap_hard_limit to print better error messages. For this purpose I
introduced a helper function virCompareLimitUlong to compare limit
values where value of 0 is equal to unlimited. Additionally the check is
now applied also when the user does not provide all of the tunables
through the API and in that case the currently set values are used.
This patch resolves:
https://bugzilla.redhat.com/show_bug.cgi?id=950478
This finds the parent for vHBA by iterating over all the HBA
which supports vport_ops capability on the host, and return
the first one which is online, not saturated (vports in use
is less than max_vports).
The helper iterates over sysfs, to find out the matched scsi host
name by comparing the wwnn,wwpn pair. It will be used by checkPool
and refreshPool of storage scsi backend. New helper getAdapterName
is introduced in storage_backend_scsi.c, which uses the new util
helper virGetFCHostNameByWWN to get the fc_host adapter name.
This abstracts nodeDeviceVportCreateDelete as an util function
virManageVport, which can be further used by later storage patches
(to support persistent vHBA, I don't want to create the vHBA
using the public API, which is not good).
This adds two util functions (virIsCapableFCHost and virIsCapableVport),
and rename helper check_fc_host_linux as detect_scsi_host_caps,
check_capable_vport_linux is removed, as it's abstracted to the util
function virIsCapableVport. detect_scsi_host_caps nows detect both
the fc_host and vport_ops capabilities. "stat(2)" is replaced with
"access(2)" for saving.
* src/util/virutil.h:
- Declare virIsCapableFCHost and virIsCapableVport
* src/util/virutil.c:
- Implement virIsCapableFCHost and virIsCapableVport
* src/node_device/node_device_linux_sysfs.c:
- Remove check_capable_vport_linux
- Rename check_fc_host_linux as detect_scsi_host_caps, and refactor
it a bit to detect both fc_host and vport_os capabilities
* src/node_device/node_device_driver.h:
- Change/remove the related declarations
* src/node_device/node_device_udev.c: (Use detect_scsi_host_caps)
* src/node_device/node_device_hal.c: (Likewise)
* src/node_device/node_device_driver.c (Likewise)
"open_wwn_file" in node_device_linux_sysfs.c is redundant, on one
hand it duplicates work of virFileReadAll, on the other hand, it's
waste to use a function for it, as there is no other users of it.
So I don't see why the file opening work cannot be done in
"read_wwn_linux".
"read_wwn_linux" can be abstracted as an util function. As what all
it does is to read the sysfs entry.
So this patch removes "open_wwn_file", and abstract "read_wwn_linux"
as an util function "virReadFCHost" (a more general name, because
after changes, it can read each of the fc_host entry now).
* src/util/virutil.h: (Declare virReadFCHost)
* src/util/virutil.c: (Implement virReadFCHost)
* src/node_device/node_device_linux_sysfs.c: (Remove open_wwn_file,
and read_wwn_linux)
src/node_device/node_device_driver.h: (Remove the declaration of
read_wwn_linux, and the related macros)
src/libvirt_private.syms: (Export virReadFCHost)
My commit 7a2e845a86 (and its
prerequisites) managed to effectively ignore the
clear_emulator_capabilities setting in qemu.conf (visible in the code
as the VIR_EXEC_CLEAR_CAPS flag when qemu is being exec'ed), with the
result that the capabilities are always cleared regardless of the
qemu.conf setting. This patch fixes it by passing the flag through to
virSetUIDGIDWithCaps(), which uses it to decide whether or not to
clear existing capabilities before adding in those that were
requested.
Note that the existing capabilities are *always* cleared if the new
process is going to run as non-root, since the whole point of running
non-root is to have the capabilities removed (it's still possible to
maintain individual capabilities as needed using the capBits argument
though).
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").
Way back when I started making changes for Coverity messages my first set
were to a bunch of CHECKED_RETURN errors. In particular virAsprintf() had
a few callers that Coverity noted didn't check their return (although some
did check if the buffer being printed to was NULL or not).
It was suggested at the time as a further patch an ATTRIBUTE_RETURN_CHECK
should be added to virAsprintf(), see:
https://www.redhat.com/archives/libvir-list/2013-January/msg00120.html
This patch does that and fixes a few more instances not found by Coverity
that failed the check.
"virGetDeviceID" could be used across the sources, but it doesn't
relate with this series, and could be done later.
* src/util/virutil.h: (Declare virGetDeviceID, and
vir{Get,Set}DeviceUnprivSGIO)
* src/util/virutil.c: (Implement virGetDeviceID and
vir{Get,Set}DeviceUnprivSGIO)
* src/libvirt_private.syms: Export private symbols of upper helpers
