[libvirt] [PATCH v4 3/3] virsh: Add support for text based polkit authentication
https://bugzilla.redhat.com/show_bug.cgi?id=872166
When the login session doesn't have an ssh -X type display agent in
order for libvirtd to run the polkit session authentication, attempts
to run 'virsh -c qemu:///system list' from an unauthorized user (or one
that isn't part of the libvirt /etc/group) will fail with the following
error from libvirtd:
error: authentication unavailable: no polkit agent available to
authenticate action 'org.libvirt.unix.manage'
In order to handle the local authentication, we will use the new
virPolkitAgentCreate API in order to create a text based authentication
agent for our non readonly session to authenticate with.
The new code will execute in a loop allowing 5 failures to authenticate
before failing out.
With this patch in place, the following occurs:
$ virsh -c qemu:///system list
==== AUTHENTICATING FOR org.libvirt.unix.manage ===
System policy prevents management of local virtualized systems
Authenticating as: Some User (SUser)
Password:
==== AUTHENTICATION COMPLETE ===
Id Name State
----------------------------------------------------
1 somedomain running
$
Signed-off-by: John Ferlan <jferlan(a)redhat.com>
---
tools/virsh.c | 38 ++++++++++++++++++++++++++++++++++----
tools/virsh.h | 1 +
2 files changed, 35 insertions(+), 4 deletions(-)
diff --git a/tools/virsh.c b/tools/virsh.c
index eb84dd0..72446be 100644
--- a/tools/virsh.c
+++ b/tools/virsh.c
@@ -143,6 +143,8 @@ virshConnect(vshControl *ctl, const char *uri, bool readonly)
int interval = 5; /* Default */
int count = 6; /* Default */
bool keepalive_forced = false;
+ virPolkitAgentPtr pkagent = NULL;
+ int authfail = 0;
if (ctl->keepalive_interval >= 0) {
interval = ctl->keepalive_interval;
@@ -153,10 +155,35 @@ virshConnect(vshControl *ctl, const char *uri, bool readonly)
keepalive_forced = true;
}
- c = virConnectOpenAuth(uri, virConnectAuthPtrDefault,
- readonly ? VIR_CONNECT_RO : 0);
+ do {
+ virErrorPtr err;
+
+ if ((c = virConnectOpenAuth(uri, virConnectAuthPtrDefault,
+ readonly ? VIR_CONNECT_RO : 0)))
+ break;
+
+ if (readonly)
+ goto cleanup;
+
+ err = virGetLastError();
+ if (err && err->domain == VIR_FROM_POLKIT &&
+ err->code == VIR_ERR_AUTH_UNAVAILABLE) {
+ if (!(pkagent = virPolkitAgentCreate()))
+ goto cleanup;
+ } else if (err && err->domain == VIR_FROM_POLKIT &&
+ err->code == VIR_ERR_AUTH_FAILED) {
+ authfail++;
+ } else {
+ goto cleanup;
+ }
+ virResetLastError();
+ /* Failure to authenticate 5 times should be enough.
+ * No sense prolonging the agony.
+ */
+ } while (authfail < 5);
+
if (!c)
- return NULL;
+ goto cleanup;
if (interval > 0 &&
virConnectSetKeepAlive(c, interval, count) != 0) {
@@ -165,12 +192,15 @@ virshConnect(vshControl *ctl, const char *uri, bool readonly)
_("Cannot setup keepalive on connection "
"as requested, disconnecting"));
virConnectClose(c);
- return NULL;
+ c = NULL;
+ goto cleanup;
}
vshDebug(ctl, VSH_ERR_INFO, "%s",
_("Failed to setup keepalive on connection\n"));
}
+ cleanup:
+ virPolkitAgentDestroy(pkagent);
return c;
}
diff --git a/tools/virsh.h b/tools/virsh.h
index 8b5e5ba..fd552bb 100644
--- a/tools/virsh.h
+++ b/tools/virsh.h
@@ -36,6 +36,7 @@
# include "internal.h"
# include "virerror.h"
# include "virthread.h"
+# include "virpolkit.h"
# include "vsh.h"
# define VIRSH_PROMPT_RW "virsh # "
--
2.5.0