Make NM work for the DHCP case, at least (dcbw) (#461071).

This patch does two things:  (1) It makes sure that NM doesn't run more than
once, though we still need to figure out why it's being asked to start up
several times.  (2) Block the rest of the network configuration process from
running until after NM is up and we can talk to it.  This fixes the traceback
where nothing is providing the .services file.

We still need to investigate whether static network configuration works and
how the UI flows in error cases.

2 files changed, 94 insertions, 6 deletions

diff --git a/isys/iface.c b/isys/iface.c
index 7a995c42c..9bc55821e 100644
--- a/isys/iface.c
+++ b/isys/iface.c
@@ -444,13 +444,101 @@ int iface_have_in6_addr(struct in6_addr *addr6) {
     return _iface_have_valid_addr(addr6, AF_INET6, INET6_ADDRSTRLEN);
 }
 
+/* Check if NM is already running */
+int is_nm_running(DBusConnection *connection, int *running, char **error_str)
+{
+    DBusError error;
+    DBusMessage *message, *reply;
+    const char *nm_service = NM_DBUS_SERVICE;
+    dbus_bool_t alive = FALSE;
+
+    message = dbus_message_new_method_call("org.freedesktop.DBus",
+                                           "/org/freedesktop/DBus",
+                                           "org.freedesktop.DBus",
+                                           "NameHasOwner");
+    if (!message)
+        return 33;
+
+    if (!dbus_message_append_args(message,
+                                  DBUS_TYPE_STRING, &nm_service,
+                                  DBUS_TYPE_INVALID)) {
+        dbus_message_unref(message);
+        return 34;
+    }
+
+    dbus_error_init(&error);
+    reply = dbus_connection_send_with_reply_and_block(connection,
+                                                        message, 2000,
+                                                        &error);
+    if (!reply) {
+        if (dbus_error_is_set(&error)) {
+            *error_str = strdup(error.message);
+            dbus_error_free(&error);
+        }
+
+        dbus_message_unref(message);
+        return 35;
+    }
+
+    dbus_error_init(&error);
+    if (!dbus_message_get_args(reply, &error,
+                                DBUS_TYPE_BOOLEAN, &alive,
+                                DBUS_TYPE_INVALID)) {
+        if (dbus_error_is_set(&error)) {
+            *error_str = strdup(error.message);
+            dbus_error_free(&error);
+        }
+
+        dbus_message_unref(message);
+        dbus_message_unref(reply);
+        return 36;
+    }
+
+    *running = alive;
+
+    dbus_message_unref(message);
+    dbus_message_unref(reply);
+    return 0;
+}
+
+/*
+ * Wait for NetworkManager to appear on the system bus
+ */
+int wait_for_nm(DBusConnection *connection, char **error_str) {
+    int count = 0;
+
+    /* send message and block until a reply or error comes back */
+    while (count < 45) {
+        int running = 0, ret;
+
+        ret = is_nm_running(connection, &running, error_str);
+        if (ret != 0)
+            return ret;  /* error */
+        if (running)
+            return 0;  /* nm is alive */
+
+        sleep(1);
+        count++;
+    }
+
+    return 37;
+}
+
 /*
  * Start NetworkManager -- requires that you have already written out the
  * control files in /etc/sysconfig for the interface.
  */
-int iface_start_NetworkManager(void) {
-    int status;
+int iface_start_NetworkManager(DBusConnection *connection, char **error) {
     pid_t pid;
+    int ret, running = 0;
+    char *ignore = NULL;
+
+    ret = is_nm_running(connection, &running, &ignore);
+    if (ignore)
+        free(ignore);
+
+    if (ret == 0 && running)
+        return 0;  /* already running */
 
     /* Start NetworkManager */
     pid = fork();
@@ -473,9 +561,7 @@ int iface_start_NetworkManager(void) {
     } else if (pid == -1) {
         return 1;
     } else {
-        if (waitpid(pid, &status, 0) == -1) {
-            return 2;
-        }
+        return wait_for_nm(connection, error);
     }
 
     return 0;
diff --git a/isys/iface.h b/isys/iface.h
index 8dcb1900a..8785db2b3 100644
--- a/isys/iface.h
+++ b/isys/iface.h
@@ -27,6 +27,8 @@
 #include <netlink/cache.h>
 #include <netlink/socket.h>
 
+#include <dbus/dbus.h>
+
 /* Enumerated types used in iface.c as well as loader's network code */
 enum { IPUNUSED, IPV4, IPV6 };
 
@@ -154,7 +156,7 @@ int iface_have_in6_addr(struct in6_addr *addr6);
 /*
  * Start NetworkManager
  */
-int iface_start_NetworkManager(void);
+int iface_start_NetworkManager(DBusConnection *connection, char **error);
 
 /*
  * Set Maximum Transfer Unit (MTU) on specified interface