X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=src%2Flaunch.c;h=e5bca56e8d3572c34a35fc602ca3fe2797912dc7;hp=9deb0cfa68f54593b5f5c95014d3625def78350c;hb=06fef60db5c7a96cb59aa92c4708e10333345e90;hpb=4b753c62089be663ac722e4a875bb061d259e87d

diff --git a/src/launch.c b/src/launch.c
index 9deb0cf..e5bca56 100644
--- a/src/launch.c
+++ b/src/launch.c
@@ -63,14 +63,12 @@
 
 #include "c-ctype.h"
 #include "glthread/lock.h"
-#include "ignore-value.h"
 
 #include "guestfs.h"
 #include "guestfs-internal.h"
 #include "guestfs-internal-actions.h"
 #include "guestfs_protocol.h"
 
-static int check_peer_euid (guestfs_h *g, int sock, uid_t *rtn);
 static int qemu_supports (guestfs_h *g, const char *option);
 
 /* Add a string to the current command line. */
@@ -134,64 +132,108 @@ guestfs__config (guestfs_h *g,
   return 0;
 }
 
-int
-guestfs__add_drive_with_if (guestfs_h *g, const char *filename,
-                            const char *drive_if)
+/* cache=off improves reliability in the event of a host crash.
+ *
+ * However this option causes qemu to try to open the file with
+ * O_DIRECT.  This fails on some filesystem types (notably tmpfs).
+ * So we check if we can open the file with or without O_DIRECT,
+ * and use cache=off (or not) accordingly.
+ */
+static int
+test_cache_off (guestfs_h *g, const char *filename)
 {
-  size_t len = strlen (filename) + 64;
-  char buf[len];
-
-  if (strchr (filename, ',') != NULL) {
-    error (g, _("filename cannot contain ',' (comma) character"));
-    return -1;
+  int fd = open (filename, O_RDONLY|O_DIRECT);
+  if (fd >= 0) {
+    close (fd);
+    return 1;
   }
 
-  /* cache=off improves reliability in the event of a host crash.
-   *
-   * However this option causes qemu to try to open the file with
-   * O_DIRECT.  This fails on some filesystem types (notably tmpfs).
-   * So we check if we can open the file with or without O_DIRECT,
-   * and use cache=off (or not) accordingly.
-   *
-   * This test also checks for the presence of the file, which
-   * is a documented semantic of this interface.
-   */
-  int fd = open (filename, O_RDONLY|O_DIRECT);
+  fd = open (filename, O_RDONLY);
   if (fd >= 0) {
     close (fd);
-    snprintf (buf, len, "file=%s,cache=off,if=%s", filename, drive_if);
-  } else {
-    fd = open (filename, O_RDONLY);
-    if (fd >= 0) {
-      close (fd);
-      snprintf (buf, len, "file=%s,if=%s", filename, drive_if);
-    } else {
-      perrorf (g, "%s", filename);
-      return -1;
-    }
+    return 0;
   }
 
-  return guestfs__config (g, "-drive", buf);
+  perrorf (g, "%s", filename);
+  return -1;
+}
+
+/* Check string parameter matches ^[-_[:alnum:]]+$ (in C locale). */
+static int
+valid_format_iface (const char *str)
+{
+  size_t len = strlen (str);
+
+  if (len == 0)
+    return 0;
+
+  while (len > 0) {
+    char c = *str++;
+    len--;
+    if (c != '-' && c != '_' && !c_isalnum (c))
+      return 0;
+  }
+  return 1;
 }
 
 int
-guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename,
-                               const char *drive_if)
+guestfs__add_drive_opts (guestfs_h *g, const char *filename,
+                         const struct guestfs_add_drive_opts_argv *optargs)
 {
+  int readonly;
+  const char *format;
+  const char *iface;
+
   if (strchr (filename, ',') != NULL) {
     error (g, _("filename cannot contain ',' (comma) character"));
     return -1;
   }
 
-  if (access (filename, F_OK) == -1) {
-    perrorf (g, "%s", filename);
+  readonly = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK
+             ? optargs->readonly : 0;
+  format = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_FORMAT_BITMASK
+           ? optargs->format : NULL;
+  iface = optargs->bitmask & GUESTFS_ADD_DRIVE_OPTS_IFACE_BITMASK
+          ? optargs->iface : DRIVE_IF;
+
+  if (format && !valid_format_iface (format)) {
+    error (g, _("%s parameter is empty or contains disallowed characters"),
+           "format");
+    return -1;
+  }
+  if (!valid_format_iface (iface)) {
+    error (g, _("%s parameter is empty or contains disallowed characters"),
+           "iface");
     return -1;
   }
 
-  size_t len = strlen (filename) + 64;
+  /* For writable files, see if we can use cache=off.  This also
+   * checks for the existence of the file.  For readonly we have
+   * to do the check explicitly.
+   */
+  int use_cache_off = readonly ? 0 : test_cache_off (g, filename);
+  if (use_cache_off == -1)
+    return -1;
+
+  if (readonly) {
+    if (access (filename, F_OK) == -1) {
+      perrorf (g, "%s", filename);
+      return -1;
+    }
+  }
+
+  /* Construct the final -drive parameter. */
+  size_t len = 64 + strlen (filename) + strlen (iface);
+  if (format) len += strlen (format);
   char buf[len];
 
-  snprintf (buf, len, "file=%s,snapshot=on,if=%s", filename, drive_if);
+  snprintf (buf, len, "file=%s%s%s%s%s,if=%s",
+            filename,
+            readonly ? ",snapshot=on" : "",
+            use_cache_off ? ",cache=off" : "",
+            format ? ",format=" : "",
+            format ? format : "",
+            iface);
 
   return guestfs__config (g, "-drive", buf);
 }
@@ -199,13 +241,48 @@ guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename,
 int
 guestfs__add_drive (guestfs_h *g, const char *filename)
 {
-  return guestfs__add_drive_with_if (g, filename, DRIVE_IF);
+  struct guestfs_add_drive_opts_argv optargs = {
+    .bitmask = 0,
+  };
+
+  return guestfs__add_drive_opts (g, filename, &optargs);
 }
 
 int
 guestfs__add_drive_ro (guestfs_h *g, const char *filename)
 {
-  return guestfs__add_drive_ro_with_if (g, filename, DRIVE_IF);
+  struct guestfs_add_drive_opts_argv optargs = {
+    .bitmask = GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK,
+    .readonly = 1,
+  };
+
+  return guestfs__add_drive_opts (g, filename, &optargs);
+}
+
+int
+guestfs__add_drive_with_if (guestfs_h *g, const char *filename,
+                            const char *iface)
+{
+  struct guestfs_add_drive_opts_argv optargs = {
+    .bitmask = GUESTFS_ADD_DRIVE_OPTS_IFACE_BITMASK,
+    .iface = iface,
+  };
+
+  return guestfs__add_drive_opts (g, filename, &optargs);
+}
+
+int
+guestfs__add_drive_ro_with_if (guestfs_h *g, const char *filename,
+                               const char *iface)
+{
+  struct guestfs_add_drive_opts_argv optargs = {
+    .bitmask = GUESTFS_ADD_DRIVE_OPTS_IFACE_BITMASK
+             | GUESTFS_ADD_DRIVE_OPTS_READONLY_BITMASK,
+    .iface = iface,
+    .readonly = 1,
+  };
+
+  return guestfs__add_drive_opts (g, filename, &optargs);
 }
 
 int
@@ -224,54 +301,14 @@ guestfs__add_cdrom (guestfs_h *g, const char *filename)
   return guestfs__config (g, "-cdrom", filename);
 }
 
-/* Returns true iff file is contained in dir. */
-static int
-dir_contains_file (const char *dir, const char *file)
-{
-  int dirlen = strlen (dir);
-  int filelen = strlen (file);
-  int len = dirlen+filelen+2;
-  char path[len];
-
-  snprintf (path, len, "%s/%s", dir, file);
-  return access (path, F_OK) == 0;
-}
-
-/* Returns true iff every listed file is contained in 'dir'. */
-static int
-dir_contains_files (const char *dir, ...)
-{
-  va_list args;
-  const char *file;
-
-  va_start (args, dir);
-  while ((file = va_arg (args, const char *)) != NULL) {
-    if (!dir_contains_file (dir, file)) {
-      va_end (args);
-      return 0;
-    }
-  }
-  va_end (args);
-  return 1;
-}
-
-static int build_supermin_appliance (guestfs_h *g, const char *path, char **kernel, char **initrd);
 static int is_openable (guestfs_h *g, const char *path, int flags);
-static void print_cmdline (guestfs_h *g);
-
-static const char *kernel_name = "vmlinuz." REPO "." host_cpu;
-static const char *initrd_name = "initramfs." REPO "." host_cpu ".img";
 
 int
 guestfs__launch (guestfs_h *g)
 {
-  int r, pmore;
-  size_t len;
+  int r;
   int wfd[2], rfd[2];
   int tries;
-  char *path, *pelem, *pend;
-  char *kernel = NULL, *initrd = NULL;
-  int null_vmchannel_sock;
   char unixsock[256];
   struct sockaddr_un addr;
 
@@ -291,10 +328,7 @@ guestfs__launch (guestfs_h *g)
 
   /* Make the temporary directory. */
   if (!g->tmpdir) {
-    const char *tmpdir = guestfs___tmpdir ();
-    char dir_template[strlen (tmpdir) + 32];
-    sprintf (dir_template, "%s/libguestfsXXXXXX", 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);
@@ -302,101 +336,17 @@ guestfs__launch (guestfs_h *g)
     }
   }
 
-  /* Allow anyone to read the temporary directory.  There are no
-   * secrets in the kernel or initrd files.  The socket in this
+  /* Allow anyone to read the temporary directory.  The socket in this
    * directory won't be readable but anyone can see it exists if they
    * want. (RHBZ#610880).
    */
   if (chmod (g->tmpdir, 0755) == -1)
     fprintf (stderr, "chmod: %s: %m (ignored)\n", g->tmpdir);
 
-  /* First search g->path for the supermin appliance, and try to
-   * synthesize a kernel and initrd from that.  If it fails, we
-   * try the path search again looking for a backup ordinary
-   * appliance.
-   */
-  pelem = path = safe_strdup (g, g->path);
-  do {
-    pend = strchrnul (pelem, ':');
-    pmore = *pend == ':';
-    *pend = '\0';
-    len = pend - pelem;
-
-    /* Empty element of "." means cwd. */
-    if (len == 0 || (len == 1 && *pelem == '.')) {
-      if (g->verbose)
-        fprintf (stderr,
-                 "looking for supermin appliance in current directory\n");
-      if (dir_contains_files (".",
-                              "supermin.d", "kmod.whitelist", NULL)) {
-        if (build_supermin_appliance (g, ".", &kernel, &initrd) == -1)
-          return -1;
-        break;
-      }
-    }
-    /* Look at <path>/supermin* etc. */
-    else {
-      if (g->verbose)
-        fprintf (stderr, "looking for supermin appliance in %s\n", pelem);
-
-      if (dir_contains_files (pelem,
-                              "supermin.d", "kmod.whitelist", NULL)) {
-        if (build_supermin_appliance (g, pelem, &kernel, &initrd) == -1)
-          return -1;
-        break;
-      }
-    }
-
-    pelem = pend + 1;
-  } while (pmore);
-
-  free (path);
-
-  if (kernel == NULL || initrd == NULL) {
-    /* Search g->path for the kernel and initrd. */
-    pelem = path = safe_strdup (g, g->path);
-    do {
-      pend = strchrnul (pelem, ':');
-      pmore = *pend == ':';
-      *pend = '\0';
-      len = pend - pelem;
-
-      /* Empty element or "." means cwd. */
-      if (len == 0 || (len == 1 && *pelem == '.')) {
-        if (g->verbose)
-          fprintf (stderr,
-                   "looking for appliance in current directory\n");
-        if (dir_contains_files (".", kernel_name, initrd_name, NULL)) {
-          kernel = safe_strdup (g, kernel_name);
-          initrd = safe_strdup (g, initrd_name);
-          break;
-        }
-      }
-      /* Look at <path>/kernel etc. */
-      else {
-        if (g->verbose)
-          fprintf (stderr, "looking for appliance in %s\n", pelem);
-
-        if (dir_contains_files (pelem, kernel_name, initrd_name, NULL)) {
-          kernel = safe_malloc (g, len + strlen (kernel_name) + 2);
-          initrd = safe_malloc (g, len + strlen (initrd_name) + 2);
-          sprintf (kernel, "%s/%s", pelem, kernel_name);
-          sprintf (initrd, "%s/%s", pelem, initrd_name);
-          break;
-        }
-      }
-
-      pelem = pend + 1;
-    } while (pmore);
-
-    free (path);
-  }
-
-  if (kernel == NULL || initrd == NULL) {
-    error (g, _("cannot find %s or %s on LIBGUESTFS_PATH (current path = %s)"),
-           kernel_name, initrd_name, g->path);
-    goto cleanup0;
-  }
+  /* Locate and/or build the appliance. */
+  char *kernel = NULL, *initrd = NULL, *appliance = NULL;
+  if (guestfs___build_appliance (g, &kernel, &initrd, &appliance) == -1)
+    return -1;
 
   if (g->verbose)
     guestfs___print_timestamped_message (g, "begin testing qemu features");
@@ -405,53 +355,35 @@ guestfs__launch (guestfs_h *g)
   if (qemu_supports (g, NULL) == -1)
     goto cleanup0;
 
-  /* Choose which vmchannel implementation to use. */
-  if (CAN_CHECK_PEER_EUID && qemu_supports (g, "-net user")) {
-    /* The "null vmchannel" implementation.  Requires SLIRP (user mode
-     * networking in qemu) but no other vmchannel support.  The daemon
-     * will connect back to a random port number on localhost.
-     */
-    struct sockaddr_in addr;
-    socklen_t addrlen = sizeof addr;
+  /* Using virtio-serial, we need to create a local Unix domain socket
+   * for qemu to connect to.
+   */
+  snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir);
+  unlink (unixsock);
 
-    g->sock = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP);
-    if (g->sock == -1) {
-      perrorf (g, "socket");
-      goto cleanup0;
-    }
-    addr.sin_family = AF_INET;
-    addr.sin_port = htons (0);
-    addr.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
-    if (bind (g->sock, (struct sockaddr *) &addr, addrlen) == -1) {
-      perrorf (g, "bind");
-      goto cleanup0;
-    }
+  g->sock = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (g->sock == -1) {
+    perrorf (g, "socket");
+    goto cleanup0;
+  }
 
-    if (listen (g->sock, 256) == -1) {
-      perrorf (g, "listen");
-      goto cleanup0;
-    }
+  if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
+    perrorf (g, "fcntl");
+    goto cleanup0;
+  }
 
-    if (getsockname (g->sock, (struct sockaddr *) &addr, &addrlen) == -1) {
-      perrorf (g, "getsockname");
-      goto cleanup0;
-    }
+  addr.sun_family = AF_UNIX;
+  strncpy (addr.sun_path, unixsock, UNIX_PATH_MAX);
+  addr.sun_path[UNIX_PATH_MAX-1] = '\0';
 
-    if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
-      perrorf (g, "fcntl");
-      goto cleanup0;
-    }
+  if (bind (g->sock, &addr, sizeof addr) == -1) {
+    perrorf (g, "bind");
+    goto cleanup0;
+  }
 
-    null_vmchannel_sock = ntohs (addr.sin_port);
-    if (g->verbose)
-      fprintf (stderr, "null_vmchannel_sock = %d\n", null_vmchannel_sock);
-  } else {
-    /* Using some vmchannel impl.  We need to create a local Unix
-     * domain socket for qemu to use.
-     */
-    snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir);
-    unlink (unixsock);
-    null_vmchannel_sock = 0;
+  if (listen (g->sock, 1) == -1) {
+    perrorf (g, "listen");
+    goto cleanup0;
   }
 
   if (!g->direct) {
@@ -478,13 +410,15 @@ guestfs__launch (guestfs_h *g)
 
   if (r == 0) {			/* Child (qemu). */
     char buf[256];
-    const char *vmchannel = NULL;
 
     /* Set up the full command line.  Do this in the subprocess so we
      * don't need to worry about cleaning up.
      */
     g->cmdline[0] = g->qemu;
 
+    if (qemu_supports (g, "-nodefconfig"))
+      add_cmdline (g, "-nodefconfig");
+
     /* qemu sometimes needs this option to enable hardware
      * virtualization, but some versions of 'qemu-kvm' will use KVM
      * regardless (even where this option appears in the help text).
@@ -513,8 +447,6 @@ guestfs__launch (guestfs_h *g)
       add_cmdline (g, "-nodefaults");
 
     add_cmdline (g, "-nographic");
-    add_cmdline (g, "-serial");
-    add_cmdline (g, "stdio");
 
     snprintf (buf, sizeof buf, "%d", g->memsize);
     add_cmdline (g, "-m");
@@ -530,65 +462,38 @@ guestfs__launch (guestfs_h *g)
     if (qemu_supports (g, "-rtc-td-hack"))
       add_cmdline (g, "-rtc-td-hack");
 
-    /* If qemu has SLIRP (user mode network) enabled then we can get
-     * away with "no vmchannel", where we just connect back to a random
-     * host port.
-     */
-    if (null_vmchannel_sock) {
-      add_cmdline (g, "-net");
-      add_cmdline (g, "user,vlan=0,net=" NETWORK);
-
-      snprintf (buf, sizeof buf,
-                "guestfs_vmchannel=tcp:" ROUTER ":%d",
-                null_vmchannel_sock);
-      vmchannel = strdup (buf);
-    }
-
-    /* New-style -net user,guestfwd=... syntax for guestfwd.  See:
-     *
-     * http://git.savannah.gnu.org/cgit/qemu.git/commit/?id=c92ef6a22d3c71538fcc48fb61ad353f7ba03b62
-     *
-     * The original suggested format doesn't work, see:
-     *
-     * http://lists.gnu.org/archive/html/qemu-devel/2009-07/msg01654.html
-     *
-     * However Gerd Hoffman privately suggested to me using -chardev
-     * instead, which does work.
-     */
-    else if (qemu_supports (g, "-chardev") && qemu_supports (g, "guestfwd")) {
-      snprintf (buf, sizeof buf,
-                "socket,id=guestfsvmc,path=%s,server,nowait", unixsock);
-
-      add_cmdline (g, "-chardev");
-      add_cmdline (g, buf);
-
-      snprintf (buf, sizeof buf,
-                "user,vlan=0,net=" NETWORK ","
-                "guestfwd=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT
-                "-chardev:guestfsvmc");
-
-      add_cmdline (g, "-net");
-      add_cmdline (g, buf);
-
-      vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT;
-    }
+    /* Create the virtio serial bus. */
+    add_cmdline (g, "-device");
+    add_cmdline (g, "virtio-serial");
 
-    /* Not guestfwd.  HOPEFULLY this qemu uses the older -net channel
-     * syntax, or if not then we'll get a quick failure.
+#if 0
+    /* Use virtio-console (a variant form of virtio-serial) for the
+     * guest's serial console.
      */
-    else {
-      snprintf (buf, sizeof buf,
-                "channel," GUESTFWD_PORT ":unix:%s,server,nowait", unixsock);
-
-      add_cmdline (g, "-net");
-      add_cmdline (g, buf);
-      add_cmdline (g, "-net");
-      add_cmdline (g, "user,vlan=0,net=" NETWORK);
+    add_cmdline (g, "-chardev");
+    add_cmdline (g, "stdio,id=console");
+    add_cmdline (g, "-device");
+    add_cmdline (g, "virtconsole,chardev=console,name=org.libguestfs.console.0");
+#else
+    /* When the above works ...  until then: */
+    add_cmdline (g, "-serial");
+    add_cmdline (g, "stdio");
+#endif
 
-      vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT;
+    /* Set up virtio-serial for the communications channel. */
+    add_cmdline (g, "-chardev");
+    snprintf (buf, sizeof buf, "socket,path=%s,id=channel0", unixsock);
+    add_cmdline (g, buf);
+    add_cmdline (g, "-device");
+    add_cmdline (g, "virtserialport,chardev=channel0,name=org.libguestfs.channel.0");
+
+    /* Enable user networking. */
+    if (g->enable_network) {
+      add_cmdline (g, "-netdev");
+      add_cmdline (g, "user,id=usernet,net=169.254.0.0/16");
+      add_cmdline (g, "-device");
+      add_cmdline (g, NET_IF ",netdev=usernet");
     }
-    add_cmdline (g, "-net");
-    add_cmdline (g, "nic,model=" NET_IF ",vlan=0");
 
 #define LINUX_CMDLINE							\
     "panic=1 "         /* force kernel to panic if daemon exits */	\
@@ -603,29 +508,44 @@ guestfs__launch (guestfs_h *g)
     snprintf (buf, sizeof buf,
               LINUX_CMDLINE
               "%s "             /* (selinux) */
-              "%s "             /* (vmchannel) */
               "%s "             /* (verbose) */
               "TERM=%s "        /* (TERM environment variable) */
               "%s",             /* (append) */
               g->selinux ? "selinux=1 enforcing=0" : "selinux=0",
-              vmchannel ? vmchannel : "",
               g->verbose ? "guestfs_verbose=1" : "",
               getenv ("TERM") ? : "linux",
               g->append ? g->append : "");
 
     add_cmdline (g, "-kernel");
-    add_cmdline (g, (char *) kernel);
+    add_cmdline (g, kernel);
     add_cmdline (g, "-initrd");
-    add_cmdline (g, (char *) initrd);
+    add_cmdline (g, initrd);
     add_cmdline (g, "-append");
     add_cmdline (g, buf);
 
+    /* Add the ext2 appliance drive (last of all). */
+    if (appliance) {
+      const char *cachemode = "";
+      if (qemu_supports (g, "cache=")) {
+        if (qemu_supports (g, "unsafe"))
+          cachemode = ",cache=unsafe";
+        else if (qemu_supports (g, "writeback"))
+          cachemode = ",cache=writeback";
+      }
+
+      char buf2[PATH_MAX + 64];
+      add_cmdline (g, "-drive");
+      snprintf (buf2, sizeof buf2, "file=%s,snapshot=on,if=" DRIVE_IF "%s",
+                appliance, cachemode);
+      add_cmdline (g, buf2);
+    }
+
     /* Finish off the command line. */
     incr_cmdline_size (g);
     g->cmdline[g->cmdline_size-1] = NULL;
 
     if (g->verbose)
-      print_cmdline (g);
+      guestfs___print_timestamped_argv (g, (const char **)g->cmdline);
 
     if (!g->direct) {
       /* Set up stdin, stdout. */
@@ -667,6 +587,8 @@ guestfs__launch (guestfs_h *g)
   kernel = NULL;
   free (initrd);
   initrd = NULL;
+  free (appliance);
+  appliance = NULL;
 
   /* Fork the recovery process off which will kill qemu if the parent
    * process fails to do so (eg. if the parent segfaults).
@@ -732,90 +654,23 @@ guestfs__launch (guestfs_h *g)
     }
   }
 
-  if (null_vmchannel_sock) {
-    int sock = -1;
-    uid_t uid;
-
-    /* Null vmchannel implementation: We listen on g->sock for a
-     * connection.  The connection could come from any local process
-     * so we must check it comes from the appliance (or at least
-     * from our UID) for security reasons.
-     */
-    while (sock == -1) {
-      sock = guestfs___accept_from_daemon (g);
-      if (sock == -1)
-        goto cleanup1;
-
-      if (check_peer_euid (g, sock, &uid) == -1)
-        goto cleanup1;
-      if (uid != geteuid ()) {
-        fprintf (stderr,
-                 "libguestfs: warning: unexpected connection from UID %d to port %d\n",
-                 uid, null_vmchannel_sock);
-        close (sock);
-        sock = -1;
-        continue;
-      }
-    }
-
-    if (fcntl (sock, F_SETFL, O_NONBLOCK) == -1) {
-      perrorf (g, "fcntl");
-      goto cleanup1;
-    }
-
-    close (g->sock);
-    g->sock = sock;
-  } else {
-    /* Other vmchannel.  Open the Unix socket.
-     *
-     * The vmchannel implementation that got merged with qemu sucks in
-     * a number of ways.  Both ends do connect(2), which means that no
-     * one knows what, if anything, is connected to the other end, or
-     * if it becomes disconnected.  Even worse, we have to wait some
-     * indeterminate time for qemu to create the socket and connect to
-     * it (which happens very early in qemu's start-up), so any code
-     * that uses vmchannel is inherently racy.  Hence this silly loop.
-     */
-    g->sock = socket (AF_UNIX, SOCK_STREAM, 0);
-    if (g->sock == -1) {
-      perrorf (g, "socket");
-      goto cleanup1;
-    }
+  g->state = LAUNCHING;
 
-    if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
-      perrorf (g, "fcntl");
-      goto cleanup1;
-    }
+  /* Wait for qemu to start and to connect back to us via
+   * virtio-serial and send the GUESTFS_LAUNCH_FLAG message.
+   */
+  r = guestfs___accept_from_daemon (g);
+  if (r == -1)
+    goto cleanup1;
 
-    addr.sun_family = AF_UNIX;
-    strncpy (addr.sun_path, unixsock, UNIX_PATH_MAX);
-    addr.sun_path[UNIX_PATH_MAX-1] = '\0';
-
-    tries = 100;
-    /* Always sleep at least once to give qemu a small chance to start up. */
-    usleep (10000);
-    while (tries > 0) {
-      r = connect (g->sock, (struct sockaddr *) &addr, sizeof addr);
-      if ((r == -1 && errno == EINPROGRESS) || r == 0)
-        goto connected;
-
-      if (errno != ENOENT)
-        perrorf (g, "connect");
-      tries--;
-      usleep (100000);
-    }
+  close (g->sock); /* Close the listening socket. */
+  g->sock = r; /* This is the accepted data socket. */
 
-    error (g, _("failed to connect to vmchannel socket"));
+  if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
+    perrorf (g, "fcntl");
     goto cleanup1;
-
-  connected: ;
   }
 
-  g->state = LAUNCHING;
-
-  /* Wait for qemu to start and to connect back to us via vmchannel and
-   * send the GUESTFS_LAUNCH_FLAG message.
-   */
   uint32_t size;
   void *buf = NULL;
   r = guestfs___recv_from_daemon (g, &size, &buf);
@@ -866,11 +721,15 @@ guestfs__launch (guestfs_h *g)
   g->state = CONFIG;
   free (kernel);
   free (initrd);
+  free (appliance);
   return -1;
 }
 
+/* Return the location of the tmpdir (eg. "/tmp") and allow users
+ * to override it at runtime using $TMPDIR.
+ */
 const char *
-guestfs___tmpdir (void)
+guestfs_tmpdir (void)
 {
   const char *tmpdir;
 
@@ -886,26 +745,41 @@ guestfs___tmpdir (void)
   return tmpdir;
 }
 
-/* This function is used to print the qemu command line before it gets
- * executed, when in verbose mode.
+/* Compute Y - X and return the result in milliseconds.
+ * Approximately the same as this code:
+ * http://www.mpp.mpg.de/~huber/util/timevaldiff.c
  */
-static void
-print_cmdline (guestfs_h *g)
+static int64_t
+timeval_diff (const struct timeval *x, const struct timeval *y)
+{
+  int64_t msec;
+
+  msec = (y->tv_sec - x->tv_sec) * 1000;
+  msec += (y->tv_usec - x->tv_usec) / 1000;
+  return msec;
+}
+
+void
+guestfs___print_timestamped_argv (guestfs_h *g, const char * argv[])
 {
   int i = 0;
   int needs_quote;
 
-  while (g->cmdline[i]) {
-    if (g->cmdline[i][0] == '-') /* -option starts a new line */
+  struct timeval tv;
+  gettimeofday (&tv, NULL);
+  fprintf (stderr, "[%05" PRIi64 "ms] ", timeval_diff (&g->launch_t, &tv));
+
+  while (argv[i]) {
+    if (argv[i][0] == '-') /* -option starts a new line */
       fprintf (stderr, " \\\n   ");
 
     if (i > 0) fputc (' ', stderr);
 
     /* Does it need shell quoting?  This only deals with simple cases. */
-    needs_quote = strcspn (g->cmdline[i], " ") != strlen (g->cmdline[i]);
+    needs_quote = strcspn (argv[i], " ") != strlen (argv[i]);
 
     if (needs_quote) fputc ('\'', stderr);
-    fprintf (stderr, "%s", g->cmdline[i]);
+    fprintf (stderr, "%s", argv[i]);
     if (needs_quote) fputc ('\'', stderr);
     i++;
   }
@@ -913,74 +787,6 @@ print_cmdline (guestfs_h *g)
   fputc ('\n', stderr);
 }
 
-/* This function does the hard work of building the supermin appliance
- * on the fly.  'path' is the directory containing the control files.
- * 'kernel' and 'initrd' are where we will return the names of the
- * kernel and initrd (only initrd is built).  The work is done by
- * an external script.  We just tell it where to put the result.
- */
-static int
-build_supermin_appliance (guestfs_h *g, const char *path,
-                          char **kernel, char **initrd)
-{
-  char cmd[4096];
-  int r, len;
-
-  if (g->verbose)
-    print_timestamped_message (g, "begin building supermin appliance");
-
-  len = strlen (g->tmpdir);
-  *kernel = safe_malloc (g, len + 8);
-  snprintf (*kernel, len+8, "%s/kernel", g->tmpdir);
-  *initrd = safe_malloc (g, len + 8);
-  snprintf (*initrd, len+8, "%s/initrd", g->tmpdir);
-
-  /* Set a sensible umask in the subprocess, so kernel and initrd
-   * output files are world-readable (RHBZ#610880).
-   */
-  snprintf (cmd, sizeof cmd,
-            "umask 0002; "
-            "febootstrap-supermin-helper%s "
-            "-k '%s/kmod.whitelist' "
-            "'%s/supermin.d' "
-            host_cpu " "
-            "%s %s",
-            g->verbose ? " --verbose" : "",
-            path,
-            path,
-            *kernel, *initrd);
-  if (g->verbose)
-    print_timestamped_message (g, "%s", cmd);
-
-  r = system (cmd);
-  if (r == -1 || WEXITSTATUS(r) != 0) {
-    error (g, _("external command failed: %s"), cmd);
-    free (*kernel);
-    free (*initrd);
-    *kernel = *initrd = NULL;
-    return -1;
-  }
-
-  if (g->verbose)
-    print_timestamped_message (g, "finished building supermin appliance");
-
-  return 0;
-}
-
-/* Compute Y - X and return the result in milliseconds.
- * Approximately the same as this code:
- * http://www.mpp.mpg.de/~huber/util/timevaldiff.c
- */
-static int64_t
-timeval_diff (const struct timeval *x, const struct timeval *y)
-{
-  int64_t msec;
-
-  msec = (y->tv_sec - x->tv_sec) * 1000;
-  msec += (y->tv_usec - x->tv_usec) / 1000;
-  return msec;
-}
-
 void
 guestfs___print_timestamped_message (guestfs_h *g, const char *fs, ...)
 {
@@ -1038,7 +844,7 @@ test_qemu (guestfs_h *g)
     goto error;
 
   snprintf (cmd, sizeof cmd, "LC_ALL=C '%s' -nographic -version 2>/dev/null",
-	    g->qemu);
+            g->qemu);
 
   fp = popen (cmd, "r");
   if (fp) {
@@ -1112,90 +918,6 @@ is_openable (guestfs_h *g, const char *path, int flags)
   return 1;
 }
 
-/* Check the peer effective UID for a TCP socket.  Ideally we'd like
- * SO_PEERCRED for a loopback TCP socket.  This isn't possible on
- * Linux (but it is on Solaris!) so we read /proc/net/tcp instead.
- */
-static int
-check_peer_euid (guestfs_h *g, int sock, uid_t *rtn)
-{
-#if CAN_CHECK_PEER_EUID
-  struct sockaddr_in peer;
-  socklen_t addrlen = sizeof peer;
-
-  if (getpeername (sock, (struct sockaddr *) &peer, &addrlen) == -1) {
-    perrorf (g, "getpeername");
-    return -1;
-  }
-
-  if (peer.sin_family != AF_INET ||
-      ntohl (peer.sin_addr.s_addr) != INADDR_LOOPBACK) {
-    error (g, "check_peer_euid: unexpected connection from non-IPv4, non-loopback peer (family = %d, addr = %s)",
-           peer.sin_family, inet_ntoa (peer.sin_addr));
-    return -1;
-  }
-
-  struct sockaddr_in our;
-  addrlen = sizeof our;
-  if (getsockname (sock, (struct sockaddr *) &our, &addrlen) == -1) {
-    perrorf (g, "getsockname");
-    return -1;
-  }
-
-  FILE *fp = fopen ("/proc/net/tcp", "r");
-  if (fp == NULL) {
-    perrorf (g, "/proc/net/tcp");
-    return -1;
-  }
-
-  char line[256];
-  if (fgets (line, sizeof line, fp) == NULL) { /* Drop first line. */
-    error (g, "unexpected end of file in /proc/net/tcp");
-    fclose (fp);
-    return -1;
-  }
-
-  while (fgets (line, sizeof line, fp) != NULL) {
-    unsigned line_our_addr, line_our_port, line_peer_addr, line_peer_port;
-    int dummy0, dummy1, dummy2, dummy3, dummy4, dummy5, dummy6;
-    int line_uid;
-
-    if (sscanf (line, "%d:%08X:%04X %08X:%04X %02X %08X:%08X %02X:%08X %08X %d",
-                &dummy0,
-                &line_our_addr, &line_our_port,
-                &line_peer_addr, &line_peer_port,
-                &dummy1, &dummy2, &dummy3, &dummy4, &dummy5, &dummy6,
-                &line_uid) == 12) {
-      /* Note about /proc/net/tcp: local_address and rem_address are
-       * always in network byte order.  However the port part is
-       * always in host byte order.
-       *
-       * The sockname and peername that we got above are in network
-       * byte order.  So we have to byte swap the port but not the
-       * address part.
-       */
-      if (line_our_addr == our.sin_addr.s_addr &&
-          line_our_port == ntohs (our.sin_port) &&
-          line_peer_addr == peer.sin_addr.s_addr &&
-          line_peer_port == ntohs (peer.sin_port)) {
-        *rtn = line_uid;
-        fclose (fp);
-        return 0;
-      }
-    }
-  }
-
-  error (g, "check_peer_euid: no matching TCP connection found in /proc/net/tcp");
-  fclose (fp);
-  return -1;
-#else /* !CAN_CHECK_PEER_EUID */
-  /* This function exists but should never be called in this
-   * configuration.
-   */
-  abort ();
-#endif /* !CAN_CHECK_PEER_EUID */
-}
-
 /* You had to call this function after launch in versions <= 1.0.70,
  * but it is now a no-op.
  */