Don't insist on getting a DBus address via env

It doesn't seem to be actually used anywhere in the code? The daemon
code already does the sensible thing and just uses library functions to
say "connect to system bus". The only use case for such a setup I could
see would be testing, but there's no test harness that makes use of
this.

Change-Id: I1098fdc33980e2f065a09bd9c0b698b5f5977d53

src/main.c

@@ -23,12 +23,12 @@
  * capability.
  *
  * Usage:
- *  - SAVE mode: DBUS_SESSION_BUS_ADDRESS=<dbus address> conntrack_migrator 2 <dbus_helper_id> <num_ip_addresses> <space separated ip address list>
- *  - LOAD mode: DBUS_SESSION_BUS_ADDRESS=<dbus address> conntrack_migrator 1 <dbus_helper_id>
+ *  - SAVE mode: conntrack_migrator 2 <dbus_helper_id> <num_ip_addresses> <space separated ip address list>
+ *  - LOAD mode: conntrack_migrator 1 <dbus_helper_id>
  *
  *  eg:
- *  - SAVE mode: DBUS_SESSION_BUS_ADDRESS=unix:abstract=/abc,guid=def conntrack_migrator 2 helper1 2 1.1.1.1 2.2.2.2
- *  - LOAD mode: DBUS_SESSION_BUS_ADDRESS=unix:abstract=/abc,guid=def conntrack_migrator 1 helper1
+ *  - SAVE mode: conntrack_migrator 2 helper1 2 1.1.1.1 2.2.2.2
+ *  - LOAD mode: conntrack_migrator 1 helper1
  */
 
 #define _GNU_SOURCE
@@ -334,8 +334,6 @@ dmain(int argc, char *argv[])
     set_log_level(lmct_conf.log_lvl);
 
     LOG(INFO, "%s: Starting in mode %s", __func__, mode_to_string[mode]);
-    LOG(INFO, "%s: dbus address %s", __func__,
-        getenv("DBUS_SYSTEM_BUS_ADDRESS"));
     LOG(INFO, "%s: helper id: %s", __func__, helper_id);
     LOG(INFO, "%s: Maximum CT entries migratable: %d", __func__,
         lmct_conf.max_entries_to_migrate);
@@ -392,12 +390,9 @@ err_usage(void)
 {
     errx(EXIT_FAILURE,
         "Usage:\n"
-        "SAVE mode: DBUS_SYSTEM_BUS_ADDRESS=<dbus address> "
-        "conntrack_migrator 2 <dbus_helper_id> <num_ip_addresses> "
+        "SAVE mode: conntrack_migrator 2 <dbus_helper_id> <num_ip_addresses> "
         "<space separated ip address list>\n"
-        "LOAD mode: DBUS_SYSTEM_BUS_ADDRESS=<dbus address> "
-        "conntrack_migrator 1 <dbus_helper_id>\n"
-        "NOTE: DBUS_SYSTEM_BUS_ADDRESS env variable should be set.\n");
+        "LOAD mode: conntrack_migrator 1 <dbus_helper_id>\n");
 }
 
 /**
@@ -415,19 +410,6 @@ check_mode(int mode)
     }
 }
 
-/**
- * Checks if the DBUS_SYSTEM_BUS_ADDRESS env variable is set.
- */
-static void
-check_dbus_address_env(void)
-{
-    const char *dbus_address = getenv("DBUS_SYSTEM_BUS_ADDRESS");
-    if (dbus_address == NULL || strcmp(dbus_address, "") == 0) {
-        errx(EXIT_FAILURE, "DBUS_SYSTEM_BUS_ADDRESS environment variable not "
-                "set\n");
-    }
-}
-
 /**
  * Performs checks on args when started in save mode.
  *
@@ -464,8 +446,7 @@ check_save_mode_args(int argc, char *argv[])
  *
  * Checks performed:
  * 1. Mode is vaild
- * 2. DBUS_SYSTEM_BUS_ADDRESS env is set
- * 3. SAVE mode has proper arguments
+ * 2. SAVE mode has proper arguments
  *
  * Args:
  *   @argc num of arguemnts
@@ -480,8 +461,6 @@ check_args(int argc, char *argv[])
         err_usage();
     }
 
-    check_dbus_address_env();
-
     mode = atoi(argv[MODE_ARG_INDEX]);
     check_mode(mode);