check the pid is > 0 before calling waitpid()

[libguestfs.git] / src / launch.c

diff --git a/src/launch.c b/src/launch.c
index a7a86b9..8de2857 100644 (file)
--- a/src/launch.c
+++ b/src/launch.c
@@ -70,6 +70,8 @@
 #include "guestfs-internal-actions.h"
 #include "guestfs_protocol.h"
 
+static int launch_appliance (guestfs_h *g);
+static int connect_unix_socket (guestfs_h *g, const char *sock);
 static int qemu_supports (guestfs_h *g, const char *option);
 
 /* Add a string to the current command line. */
@@ -350,32 +352,19 @@ static int is_openable (guestfs_h *g, const char *path, int flags);
 int
 guestfs__launch (guestfs_h *g)
 {
-  int r;
-  int wfd[2], rfd[2];
-  char unixsock[256];
-  struct sockaddr_un addr;
-
   /* Configured? */
-  if (!g->cmdline) {
-    error (g, _("you must call guestfs_add_drive before guestfs_launch"));
-    return -1;
-  }
-
   if (g->state != CONFIG) {
     error (g, _("the libguestfs handle has already been launched"));
     return -1;
   }
 
-  /* Start the clock ... */
-  gettimeofday (&g->launch_t, NULL);
-
   /* Make the temporary directory. */
   if (!g->tmpdir) {
     TMP_TEMPLATE_ON_STACK (dir_template);
     g->tmpdir = safe_strdup (g, dir_template);
     if (mkdtemp (g->tmpdir) == NULL) {
       perrorf (g, _("%s: cannot create temporary directory"), dir_template);
-      goto cleanup0;
+      return -1;
     }
   }
 
@@ -386,6 +375,38 @@ guestfs__launch (guestfs_h *g)
   if (chmod (g->tmpdir, 0755) == -1)
     fprintf (stderr, "chmod: %s: %m (ignored)\n", g->tmpdir);
 
+  /* Launch the appliance or attach to an existing daemon. */
+  switch (g->attach_method) {
+  case ATTACH_METHOD_APPLIANCE:
+    return launch_appliance (g);
+
+  case ATTACH_METHOD_UNIX:
+    return connect_unix_socket (g, g->attach_method_arg);
+
+  default:
+    abort ();
+  }
+}
+
+static int
+launch_appliance (guestfs_h *g)
+{
+  int r;
+  int wfd[2], rfd[2];
+  char unixsock[256];
+  struct sockaddr_un addr;
+
+  /* At present you must add drives before starting the appliance.  In
+   * future when we enable hotplugging you won't need to do this.
+   */
+  if (!g->cmdline) {
+    error (g, _("you must call guestfs_add_drive before guestfs_launch"));
+    return -1;
+  }
+
+  /* Start the clock ... */
+  gettimeofday (&g->launch_t, NULL);
+
   /* Locate and/or build the appliance. */
   char *kernel = NULL, *initrd = NULL, *appliance = NULL;
   if (guestfs___build_appliance (g, &kernel, &initrd, &appliance) == -1)
@@ -748,7 +769,7 @@ guestfs__launch (guestfs_h *g)
   }
   if (g->pid > 0) kill (g->pid, 9);
   if (g->recoverypid > 0) kill (g->recoverypid, 9);
-  waitpid (g->pid, NULL, 0);
+  if (g->pid > 0) waitpid (g->pid, NULL, 0);
   if (g->recoverypid > 0) waitpid (g->recoverypid, NULL, 0);
   g->fd[0] = -1;
   g->fd[1] = -1;
@@ -768,6 +789,78 @@ guestfs__launch (guestfs_h *g)
   return -1;
 }
 
+/* Alternate attach method: instead of launching the appliance,
+ * connect to an existing unix socket.
+ */
+static int
+connect_unix_socket (guestfs_h *g, const char *sockpath)
+{
+  int r;
+  struct sockaddr_un addr;
+
+  /* Start the clock ... */
+  gettimeofday (&g->launch_t, NULL);
+
+  /* Set these to nothing so we don't try to kill random processes or
+   * read from random file descriptors.
+   */
+  g->pid = 0;
+  g->recoverypid = 0;
+  g->fd[0] = -1;
+  g->fd[1] = -1;
+
+  if (g->verbose)
+    guestfs___print_timestamped_message (g, "connecting to %s", sockpath);
+
+  g->sock = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (g->sock == -1) {
+    perrorf (g, "socket");
+    return -1;
+  }
+
+  addr.sun_family = AF_UNIX;
+  strncpy (addr.sun_path, sockpath, UNIX_PATH_MAX);
+  addr.sun_path[UNIX_PATH_MAX-1] = '\0';
+
+  g->state = LAUNCHING;
+
+  if (connect (g->sock, &addr, sizeof addr) == -1) {
+    perrorf (g, "bind");
+    goto cleanup;
+  }
+
+  if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
+    perrorf (g, "fcntl");
+    goto cleanup;
+  }
+
+  uint32_t size;
+  void *buf = NULL;
+  r = guestfs___recv_from_daemon (g, &size, &buf);
+  free (buf);
+
+  if (r == -1) return -1;
+
+  if (size != GUESTFS_LAUNCH_FLAG) {
+    error (g, _("guestfs_launch failed, unexpected initial message from guestfsd"));
+    goto cleanup;
+  }
+
+  if (g->verbose)
+    guestfs___print_timestamped_message (g, "connected");
+
+  if (g->state != READY) {
+    error (g, _("contacted guestfsd, but state != READY"));
+    goto cleanup;
+  }
+
+  return 0;
+
+ cleanup:
+  close (g->sock);
+  return -1;
+}
+
 /* Return the location of the tmpdir (eg. "/tmp") and allow users
  * to override it at runtime using $TMPDIR.
  * http://www.pathname.com/fhs/pub/fhs-2.3.html#TMPTEMPORARYFILES