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.aspxSigned-off-by: NDaniel P. Berrange <berrange@redhat.com>

In making the conversion to the new API, I fixed a couple bugs:
virSCSIDeviceGetSgName would leak memory if a directory
unexpectedly contained multiple entries;
virNetDevTapGetRealDeviceName could report a spurious error
from a stale errno inherited before starting the readdir search.

The decision on whether to store the result of virDirRead into
a variable is based on whether the end of the loop falls through
to cleanup code automatically.  In some cases, we have loops that
are documented to return NULL on failure, and which raise an
error on most failure paths but not in the case where the directory
was unexpectedly empty; it may be worth a followup patch to
explicitly report an error if readdir was successful but the
directory was empty, so that a NULL return always has an error set.

* src/util/vircgroup.c (virCgroupRemoveRecursively): Use new
interface.
(virCgroupKillRecursiveInternal, virCgroupSetOwner): Report
readdir failures.
* src/util/virfile.c (virFileLoopDeviceOpenSearch)
(virFileNBDDeviceFindUnused, virFileDeleteTree): Use new
interface.
* src/util/virnetdevtap.c (virNetDevTapGetRealDeviceName):
Properly check readdir errors.
* src/util/virpci.c (virPCIDeviceIterDevices)
(virPCIDeviceFileIterate, virPCIGetNetName): Report readdir
failures.
(virPCIDeviceAddressIOMMUGroupIterate): Use new interface.
* src/util/virscsi.c (virSCSIDeviceGetSgName): Report readdir
failures, and avoid memory leak.
(virSCSIDeviceGetDevName): Report readdir failures.
* src/util/virusb.c (virUSBDeviceSearch): Report readdir
failures.
* src/util/virutil.c (virGetFCHostNameByWWN)
(virFindFCHostCapableVport): Report readdir failures.
Signed-off-by: NEric Blake <eblake@redhat.com>

Signed-off-by: NMartin Kletzander <mkletzan@redhat.com>

Any source file which calls the logging APIs now needs
to have a VIR_LOG_INIT("source.name") declaration at
the start of the file. This provides a static variable
of the virLogSource type.
Signed-off-by: NDaniel 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: NDaniel P. Berrange <berrange@redhat.com>

The return value of virGetFCHostNameByWWN is a strdup'ed string.
Also add comments to declare that the caller should take care of
freeing it.

The use of getenv is typically insecure, and we want people
to use our wrappers, to force them to think about setuid
needs.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

Unconditional use of getenv is not secure in setuid env.
While not all libvirt code runs in a setuid env (since
much of it only exists inside libvirtd) this is not always
clear to developers. So make all the code paranoid, even
if it only ever runs inside libvirtd.
Signed-off-by: NDaniel 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: NDaniel 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: NBing Bu Cao <mars@linux.vnet.ibm.com>
Signed-off-by: NEric Blake <eblake@redhat.com>

Semantics of the libvirt helper are more clear. This change also allows
to clean up some pieces of code.

When virGetUserEnt() and virGetGroupEnt() fail due to the uid or gid not
existing on the machine they'll print a message like:

$ virsh -c vbox:///session list
error: failed to connect to the hypervisor
error: Failed to find user record for uid '32655': Success

The success at the end is a bit confusing. This changes it to:

$ virsh -c vbox:///session list
error: failed to connect to the hypervisor
error: Failed to find user record for uid '32655'

Commit 3d0e3c1a reintroduced a problem previously squelched in
commit 7e5aa78d.  Add a syntax check this time around.

util/virutil.c: In function 'virGetGroupList':
util/virutil.c:1015: error: 'for' loop initial declaration used outside C99 mode

* cfg.mk (sc_prohibit_loop_var_decl): New rule.
* src/util/virutil.c (virGetGroupList): Fix offender.
Signed-off-by: NEric Blake <eblake@redhat.com>

The change from initgroups to virGetGroupList/setgroups in
cab36cfe71ba83b71e536ba5c98e596f02b697b0 dropped the primary group from
processes group list iff the passed in group to virGetGroupList differs
from the user's primary group.

So always include the primary group to bring back the old behaviour.

Debian has the kvm group as primary group but uses
libvirt-qemu:libvirt-qemu as user:group to run the kvm process so
without this change the /dev/kvm is inaccessible.

This function is needed for virt-login-shell.  Also modify virGirUserDirectory
to use the new function, to simplify the code.
Signed-off-by: NEric Blake <eblake@redhat.com>

On platforms without decent group support, the build failed:

Cannot export virGetGroupList: symbol not defined
./.libs/libvirt_security_manager.a(libvirt_security_manager_la-security_dac.o): In function `virSecurityDACPreFork':
/home/eblake/libvirt-tmp/build/src/../../src/security/security_dac.c:248: undefined reference to `virGetGroupList'
collect2: error: ld returned 1 exit status

* src/util/virutil.c (virGetGroupList): Provide dummy implementation.
Signed-off-by: NEric 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: NEric 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: NEric Blake <eblake@redhat.com>

A future patch needs to look up pw_gid; but it is wasteful
to crawl through getpwuid_r twice for two separate pieces
of information, and annoying to copy that much boilerplate
code for doing the crawl.  The current internal-only
virGetUserEnt is also a rather awkward interface; it's easier
to just design it to let callers request multiple pieces of
data as needed from one traversal.

And while at it, I noticed that virGetXDGDirectory could deref
NULL if the getpwuid_r lookup fails.

* src/util/virutil.c (virGetUserEnt): Alter signature.
(virGetUserDirectory, virGetXDGDirectory, virGetUserName): Adjust
callers.
Signed-off-by: NEric Blake <eblake@redhat.com>

Convert the type of loop iterators named 'i', 'j', k',
'ii', 'jj', 'kk', to be 'size_t' instead of 'int' or
'unsigned int', also santizing 'ii', 'jj', 'kk' to use
the normal 'i', 'j', 'k' naming
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

When creating a virtual FC HBA with virsh/libvirt API, an error message
will be returned: "error: Node device not found",
also the 'nodedev-dumpxml' shows wrong information of wwpn & wwnn
for the new created device.

Signed-off-by: xschen@tnsoft.com.cn

This reverts f90af691 which switched wwpn & wwwn in the wrong place.

https://www.kernel.org/doc/Documentation/scsi/scsi_fc_transport.txt

In the first if case, virGetUserEnt() isn't necessary so don't bother
calling it before determining we need it.

Found with 'git grep "= 1"'.

Compilation for mingw failed:

../../src/util/virutil.c: In function 'virGetWin32DirectoryRoot':
../../src/util/virutil.c:1094:9: error: unused variable 'ret' [-Werror=unused-variable]

* src/util/virutil.c (virGetWin32DirectoryRoot): Silence compiler
warning.
Signed-off-by: NEric Blake <eblake@redhat.com>

stdlib.h header file needed for getenv was only transitively included
through libdevmapper.h.

The helper works for default sysfs_prefix, but for user specified
prefix, it doesn't work. (Detected when writing test cases. A later
patch will add the test cases for fc_host).

The returned result is something like "host5" acutally.

Function name with "aIsB" generally means its return value is
in Bi-state (true/false).

In case of the caller can pass a "prefix" (or "sysfs_prefix")
without the trailing slash, and Unix-Like system always eats
up the redundant "slash" in the filepath, let's add it explicitly.

Which refactored the old code, and introduced new helper
virIsCapableVport, but the path for checking with access() is not
correctly constructed.

Introduced by commit 244ce462, which refactored the helper for wwn
reading, however, it forgot to change the old "strndup" and "sizeof(buf)",
"sizeof(buf)" operates on the fixed length array ("buf") in the old code,
but now "buf" is a pointer.

Before the fix:

% virsh nodedev-dumpxml scsi_host5
<device>
  <name>scsi_host5</name>
  <parent>pci_0000_04_00_1</parent>
  <capability type='scsi_host'>
    <host>5</host>
    <capability type='fc_host'>
      <wwnn>2001001b</wwnn>
      <wwpn>2101001b</wwpn>
      <fabric_wwn>2001000d</fabric_wwn>
    </capability>
  </capability>
</device>

With the fix:

% virsh nodedev-dumpxml scsi_host5
<device>
  <name>scsi_host5</name>
  <parent>pci_0000_04_00_1</parent>
  <capability type='scsi_host'>
    <host>5</host>
    <capability type='fc_host'>
      <wwnn>0x2001001b32a9da4e</wwnn>
      <wwpn>0x2101001b32a9da4e</wwpn>
      <fabric_wwn>0x2001000dec9877c1</fabric_wwn>
    </capability>
  </capability>
</device>

Commit bfe7721d introduced a regression, but only on platforms
like FreeBSD that lack posix_fallocate and where mmap serves as
a nice fallback for safezero.

util/virfile.c: In function 'safezero':
util/virfile.c:837: error: 'PROT_READ' undeclared (first use in this function)

* src/util/virutil.c (includes): Move use of <sys/mman.h>...
* src/util/virfile.c (includes): ...to the file that uses mmap.
Signed-off-by: NEric 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.