From 172acef486103313963e3f1b5190300f8f877339 Mon Sep 17 00:00:00 2001
From: Michal Privoznik <mprivozn@redhat.com>
Date: Thu, 12 Mar 2015 14:28:15 +0100
Subject: [PATCH] network_driver: Use accessor for dnsmasqCaps

This is not an immutable pointer and can change during lifetime.
Therefore, in order to drop network driver lock, we must use an
internal accessor which does not lock the network driver yet, but
it will soon. Now it merely returns an referenced object.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
---
 src/network/bridge_driver.c | 42 +++++++++++++++++++++++++++++++------
 1 file changed, 36 insertions(+), 6 deletions(-)

diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 6ff453961a..863eeac6b6 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -106,6 +106,27 @@ static void networkDriverUnlock(virNetworkDriverStatePtr driver)
     virMutexUnlock(&driver->lock);
 }
 
+static dnsmasqCapsPtr
+networkGetDnsmasqCaps(virNetworkDriverStatePtr driver)
+{
+    dnsmasqCapsPtr ret;
+    ret = virObjectRef(driver->dnsmasqCaps);
+    return ret;
+}
+
+static int
+networkDnsmasqCapsRefresh(virNetworkDriverStatePtr driver)
+{
+    dnsmasqCapsPtr caps;
+
+    if (!(caps = dnsmasqCapsNewFromBinary(DNSMASQ)))
+        return -1;
+
+    virObjectUnref(driver->dnsmasqCaps);
+    driver->dnsmasqCaps = caps;
+    return 0;
+}
+
 static int networkStateCleanup(void);
 
 static int networkStartNetwork(virNetworkDriverStatePtr driver,
@@ -364,6 +385,7 @@ networkUpdateState(virNetworkObjPtr obj,
                    void *opaque)
 {
     virNetworkDriverStatePtr driver = opaque;
+    dnsmasqCapsPtr dnsmasq_caps = networkGetDnsmasqCaps(driver);
     int ret = -1;
 
     virObjectLock(obj);
@@ -408,7 +430,7 @@ networkUpdateState(virNetworkObjPtr obj,
         ignore_value(virPidFileReadIfAlive(driver->pidDir,
                                            obj->def->name,
                                            &obj->dnsmasqPid,
-                                           dnsmasqCapsGetBinaryPath(driver->dnsmasqCaps)));
+                                           dnsmasqCapsGetBinaryPath(dnsmasq_caps)));
         radvdpidbase = networkRadvdPidfileBasename(obj->def->name);
         if (!radvdpidbase)
             goto cleanup;
@@ -422,6 +444,7 @@ networkUpdateState(virNetworkObjPtr obj,
     ret = 0;
  cleanup:
     virObjectUnlock(obj);
+    virObjectUnref(dnsmasq_caps);
     return ret;
 }
 
@@ -1284,6 +1307,7 @@ networkBuildDhcpDaemonCommandLine(virNetworkDriverStatePtr driver,
                                   char *pidfile,
                                   dnsmasqContext *dctx)
 {
+    dnsmasqCapsPtr dnsmasq_caps = networkGetDnsmasqCaps(driver);
     virCommandPtr cmd = NULL;
     int ret = -1;
     char *configfile = NULL;
@@ -1293,7 +1317,7 @@ networkBuildDhcpDaemonCommandLine(virNetworkDriverStatePtr driver,
     network->dnsmasqPid = -1;
 
     if (networkDnsmasqConfContents(network, pidfile, &configstr,
-                                   dctx, driver->dnsmasqCaps) < 0)
+                                   dctx, dnsmasq_caps) < 0)
         goto cleanup;
     if (!configstr)
         goto cleanup;
@@ -1316,7 +1340,7 @@ networkBuildDhcpDaemonCommandLine(virNetworkDriverStatePtr driver,
                                                   LIBEXECDIR)))
         goto cleanup;
 
-    cmd = virCommandNew(dnsmasqCapsGetBinaryPath(driver->dnsmasqCaps));
+    cmd = virCommandNew(dnsmasqCapsGetBinaryPath(dnsmasq_caps));
     virCommandAddArgFormat(cmd, "--conf-file=%s", configfile);
     /* Libvirt gains full control of leases database */
     virCommandAddArgFormat(cmd, "--leasefile-ro");
@@ -1326,6 +1350,7 @@ networkBuildDhcpDaemonCommandLine(virNetworkDriverStatePtr driver,
     *cmdout = cmd;
     ret = 0;
  cleanup:
+    virObjectUnref(dnsmasq_caps);
     VIR_FREE(configfile);
     VIR_FREE(configstr);
     VIR_FREE(leaseshelper_path);
@@ -1369,7 +1394,7 @@ networkStartDhcpDaemon(virNetworkDriverStatePtr driver,
     if (dctx == NULL)
         goto cleanup;
 
-    if (dnsmasqCapsRefresh(&driver->dnsmasqCaps, NULL) < 0)
+    if (networkDnsmasqCapsRefresh(driver) < 0)
         goto cleanup;
 
     ret = networkBuildDhcpDaemonCommandLine(driver, network, &cmd, pidfile, dctx);
@@ -1623,6 +1648,7 @@ static int
 networkStartRadvd(virNetworkDriverStatePtr driver,
                   virNetworkObjPtr network)
 {
+    dnsmasqCapsPtr dnsmasq_caps = networkGetDnsmasqCaps(driver);
     char *pidfile = NULL;
     char *radvdpidbase = NULL;
     char *configfile = NULL;
@@ -1632,7 +1658,7 @@ networkStartRadvd(virNetworkDriverStatePtr driver,
     network->radvdPid = -1;
 
     /* Is dnsmasq handling RA? */
-    if (DNSMASQ_RA_SUPPORT(driver->dnsmasqCaps)) {
+    if (DNSMASQ_RA_SUPPORT(dnsmasq_caps)) {
         ret = 0;
         goto cleanup;
     }
@@ -1698,6 +1724,7 @@ networkStartRadvd(virNetworkDriverStatePtr driver,
 
     ret = 0;
  cleanup:
+    virObjectUnref(dnsmasq_caps);
     virCommandFree(cmd);
     VIR_FREE(configfile);
     VIR_FREE(radvdpidbase);
@@ -1709,10 +1736,12 @@ static int
 networkRefreshRadvd(virNetworkDriverStatePtr driver,
                     virNetworkObjPtr network)
 {
+    dnsmasqCapsPtr dnsmasq_caps = networkGetDnsmasqCaps(driver);
     char *radvdpidbase;
 
     /* Is dnsmasq handling RA? */
-    if (DNSMASQ_RA_SUPPORT(driver->dnsmasqCaps)) {
+    if (DNSMASQ_RA_SUPPORT(dnsmasq_caps)) {
+        virObjectUnref(dnsmasq_caps);
         if (network->radvdPid <= 0)
             return 0;
         /* radvd should not be running but in case it is */
@@ -1726,6 +1755,7 @@ networkRefreshRadvd(virNetworkDriverStatePtr driver,
         network->radvdPid = -1;
         return 0;
     }
+    virObjectUnref(dnsmasq_caps);
 
     /* if there's no running radvd, just start it */
     if (network->radvdPid <= 0 || (kill(network->radvdPid, 0) < 0))