resolve: Make path to resolvconf(8) configurable

Prefer the configured command over finding it at the default location
over installing in the configured file.

References strongswan/strongswan#744

diff --git a/conf/plugins/resolve.opt b/conf/plugins/resolve.opt
index ce65eff9e1492cfd74121612abff0e3f3516db4e..089576102f25a62b7e91eb5b378e4fa598904dbb 100644 (file)
--- a/conf/plugins/resolve.opt
+++ b/conf/plugins/resolve.opt
@@ -1,5 +1,5 @@
 charon.plugins.resolve.file = /etc/resolv.conf
-       File where to add DNS server entries.
+       File where to add DNS server entries if not using resolvconf(8).
 
 charon.plugins.resolve.resolvconf.iface_prefix = lo.inet.ipsec.
        Prefix used for interface names sent to resolvconf(8).
@@ -9,3 +9,13 @@ charon.plugins.resolve.resolvconf.iface_prefix = lo.inet.ipsec.
        a valid interface name according to the rules defined by resolvconf.  Also,
        it should have a high priority according to the order defined in
        **interface-order**(5).
+
+charon.plugins.resolve.resolvconf.path = /sbin/resolvconf
+       Path/command for resolvconf(8).
+
+       Path/command for **resolvconf**(8). The command is executed by a shell, so
+       "resolvconf" will work if it's in $PATH of the daemon.
+
+       If not configured, **resolvconf**(8) will be used if found at the default
+       location.  Otherwise, the file in _charon.plugins.resolve.file_ will be
+       modfied directly.

diff --git a/src/libcharon/plugins/resolve/resolve_handler.c b/src/libcharon/plugins/resolve/resolve_handler.c
index 9b906fc05924356fcf45bc475f95b53e57dee799..391d0b276b03e0015df0d571389f6cafa928d8c3 100644 (file)
--- a/src/libcharon/plugins/resolve/resolve_handler.c
+++ b/src/libcharon/plugins/resolve/resolve_handler.c
@@ -50,9 +50,9 @@ struct private_resolve_handler_t {
        char *file;
 
        /**
-        * Use resolvconf instead of writing directly to resolv.conf
+        * Path/command for resolvconf(8)
         */
-       bool use_resolvconf;
+       char *resolvconf;
 
        /**
         * Prefix to be used for interface names sent to resolvconf
@@ -196,7 +196,7 @@ static bool invoke_resolvconf(private_resolve_handler_t *this, host_t *addr,
        /* we use the nameserver's IP address as part of the interface name to
         * make them unique */
        process = process_start_shell(NULL, install ? &in : NULL, &out, NULL,
-                                                       "2>&1 %s %s %s%H", RESOLVCONF_EXEC,
+                                                       "2>&1 %s %s %s%H", this->resolvconf,
                                                        install ? "-a" : "-d", this->iface_prefix, addr);
 
        if (!process)
@@ -295,7 +295,7 @@ METHOD(attribute_handler_t, handle, bool,
        this->mutex->lock(this->mutex);
        if (array_bsearch(this->servers, addr, dns_server_find, &found) == -1)
        {
-               if (this->use_resolvconf)
+               if (this->resolvconf)
                {
                        handled = invoke_resolvconf(this, addr, TRUE);
                }
@@ -362,7 +362,7 @@ METHOD(attribute_handler_t, release, void,
                }
                else
                {
-                       if (this->use_resolvconf)
+                       if (this->resolvconf)
                        {
                                invoke_resolvconf(this, addr, FALSE);
                        }
@@ -483,17 +483,28 @@ resolve_handler_t *resolve_handler_create()
                        .destroy = _destroy,
                },
                .mutex = mutex_create(MUTEX_TYPE_DEFAULT),
-               .file = lib->settings->get_str(lib->settings, "%s.plugins.resolve.file",
-                                                                          RESOLV_CONF, lib->ns),
+               .file = lib->settings->get_str(lib->settings,
+                                                               "%s.plugins.resolve.file", RESOLV_CONF, lib->ns),
+               .resolvconf = lib->settings->get_str(lib->settings,
+                                                               "%s.plugins.resolve.resolvconf.path",
+                                                               NULL, lib->ns),
+               .iface_prefix = lib->settings->get_str(lib->settings,
+                                                               "%s.plugins.resolve.resolvconf.iface_prefix",
+                                                               RESOLVCONF_PREFIX, lib->ns),
        );
 
-       if (stat(RESOLVCONF_EXEC, &st) == 0)
+       if (!this->resolvconf && stat(RESOLVCONF_EXEC, &st) == 0)
        {
-               this->use_resolvconf = TRUE;
-               this->iface_prefix = lib->settings->get_str(lib->settings,
-                                                               "%s.plugins.resolve.resolvconf.iface_prefix",
-                                                               RESOLVCONF_PREFIX, lib->ns);
+               this->resolvconf = RESOLVCONF_EXEC;
        }
 
+       if (this->resolvconf)
+       {
+               DBG1(DBG_CFG, "using '%s' to install DNS servers", this->resolvconf);
+       }
+       else
+       {
+               DBG1(DBG_CFG, "install DNS servers in '%s'", this->file);
+       }
        return &this->public;
 }