mirrors/libguestfs
1
0
Fork 0
mirror of https://github.com/libguestfs/libguestfs.git synced 2026-03-22 07:03:38 +00:00
Code Issues Packages Projects Releases Wiki Activity

debian: Warn if /dev/kvm is 0660 and user is not in the KVM group.

Browse Source 
On Debian, /dev/kvm is mode 0660 and group kvm, so users need to add
themselves to the kvm group otherwise things are going to be very slow
(this is Debian bug 640328).
This commit is contained in:
Richard W.M. Jones
2013-10-11 13:24:59 +01:00
parent 92e1864913
commit ff738d1480
1 changed files with 64 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

64
src/launch-direct.c
View File

@@ -28,9 +28,11 @@
#include <fcntl.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <signal.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <grp.h>
#include <pcre.h>
@@ -155,6 +157,66 @@ add_cmdline_shell_unquoted (guestfs_h *g, struct stringsbuf *sb,
}
}
/* On Debian, /dev/kvm is mode 0660 and group kvm, so users need to
* add themselves to the kvm group otherwise things are going to be
* very slow (this is Debian bug 640328). Warn about this.
*/
static void
debian_kvm_warning (guestfs_h *g)
{
#ifdef __linux__
uid_t euid = geteuid ();
gid_t egid = getegid ();
struct stat statbuf;
gid_t kvm_group;
CLEANUP_FREE gid_t *groups = NULL;
int ngroups;
size_t i;
/* Doesn't apply if running as root. */
if (euid == 0)
return;
if (stat ("/dev/kvm", &statbuf) == -1)
return;
if ((statbuf.st_mode & 0777) != 0660)
return;
/* They might be running libguestfs as root or have chowned /dev/kvm, so: */
if (geteuid () == statbuf.st_uid)
return;
kvm_group = statbuf.st_gid;
/* Is the current process a member of the KVM group? */
if (egid == kvm_group)
return;
ngroups = getgroups (0, NULL);
if (ngroups > 0) {
groups = safe_malloc (g, ngroups * sizeof (gid_t));
if (getgroups (ngroups, groups) == -1) {
warning (g, "getgroups: %m (ignored)");
return;
}
for (i = 0; i < (size_t) ngroups; ++i) {
if (groups[i] == kvm_group)
return;
}
}
/* No, so emit the warning. Note that \n characters cannot appear
* in warnings.
*/
warning (g,
_("current user is not a member of the KVM group (group ID %d). "
"This user cannot access /dev/kvm, so libguestfs may run very slowly. "
"It is recommended that you 'chmod 0666 /dev/kvm' or add the current user "
"to the KVM group (you might need to log out and log in again)."),
(int) kvm_group);
#endif /* __linux__ */
}
static int
launch_direct (guestfs_h *g, void *datav, const char *arg)
{
@@ -185,6 +247,8 @@ launch_direct (guestfs_h *g, void *datav, const char *arg)
return -1;
}
debian_kvm_warning (g);
guestfs___launch_send_progress (g, 0);
TRACE0 (launch_build_appliance_start);