- const char *tmpdir;
- char dir_template[PATH_MAX];
- int r, pmore;
- size_t len;
- int wfd[2], rfd[2];
- int tries;
- char *path, *pelem, *pend;
- char *kernel = NULL, *initrd = NULL;
- char unixsock[256];
- struct sockaddr_un addr;
-
-#ifdef P_tmpdir
- tmpdir = P_tmpdir;
-#else
- tmpdir = "/tmp";
-#endif
-
- tmpdir = getenv ("TMPDIR") ? : tmpdir;
- snprintf (dir_template, sizeof dir_template, "%s/libguestfsXXXXXX", tmpdir);
-
- /* Configured? */
- if (!g->cmdline) {
- error (g, _("you must call guestfs_add_drive before guestfs_launch"));
- return -1;
- }
-
- if (g->state != CONFIG) {
- error (g, _("qemu has already been launched"));
- return -1;
- }
-
- /* Make the temporary directory. */
- if (!g->tmpdir) {
- g->tmpdir = safe_strdup (g, dir_template);
- if (mkdtemp (g->tmpdir) == NULL) {
- perrorf (g, _("%s: cannot create temporary directory"), dir_template);
- goto cleanup0;
- }
- }
-
- /* 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_name, supermin_hostfiles_name,
- "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_name, supermin_hostfiles_name,
- "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;
- }
-
- /* Get qemu help text and version. */
- if (test_qemu (g) == -1)
- goto cleanup0;
-
- /* Make the vmchannel socket. */
- snprintf (unixsock, sizeof unixsock, "%s/sock", g->tmpdir);
- unlink (unixsock);
-
- if (pipe (wfd) == -1 || pipe (rfd) == -1) {
- perrorf (g, "pipe");
- goto cleanup0;
- }
-
- r = fork ();
- if (r == -1) {
- perrorf (g, "fork");
- close (wfd[0]);
- close (wfd[1]);
- close (rfd[0]);
- close (rfd[1]);
- goto cleanup0;
- }
-
- if (r == 0) { /* Child (qemu). */
- char buf[256];
-
- /* 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;
-
- snprintf (buf, sizeof buf, "%d", g->memsize);
- add_cmdline (g, "-m");
- add_cmdline (g, buf);
-
- add_cmdline (g, "-no-reboot"); /* Force exit instead of reboot on panic */
- add_cmdline (g, "-nographic");
- add_cmdline (g, "-serial");
- add_cmdline (g, "stdio");
-
- /* These options recommended by KVM developers to improve reliability. */
- if (qemu_supports (g, "-no-hpet"))
- add_cmdline (g, "-no-hpet");
-
- if (qemu_supports (g, "-rtc-td-hack"))
- add_cmdline (g, "-rtc-td-hack");
-
- if (qemu_supports (g, "-chardev") && qemu_supports (g, "guestfwd")) {
- /* 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.
- */
- 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=10.0.2.0/8,"
- "guestfwd=tcp:%s:%d-chardev:guestfsvmc",
- GUESTFWD_ADDR, GUESTFWD_PORT);
-
- add_cmdline (g, "-net");
- add_cmdline (g, buf);
- } else {
- /* Not guestfwd. HOPEFULLY this qemu uses the older -net channel
- * syntax, or if not then we'll get a quick failure.
- */
- snprintf (buf, sizeof buf,
- "channel,%d:unix:%s,server,nowait", GUESTFWD_PORT, unixsock);
-
- add_cmdline (g, "-net");
- add_cmdline (g, buf);
- add_cmdline (g, "-net");
- add_cmdline (g, "user,vlan=0,net=10.0.2.0/8");
- }
- 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 */ \
- "console=ttyS0 " /* serial console */ \
- "udevtimeout=300 " /* good for very slow systems (RHBZ#480319) */ \
- "noapic " /* workaround for RHBZ#502058 - ok if not SMP */ \
- "acpi=off " /* we don't need ACPI, turn it off */ \
- "cgroup_disable=memory " /* saves us about 5 MB of RAM */
-
- /* Linux kernel command line. */
- snprintf (buf, sizeof buf,
- LINUX_CMDLINE
- "%s" /* (selinux) */
- "%s" /* (verbose) */
- "%s", /* (append) */
- g->selinux ? "selinux=1 enforcing=0 " : "selinux=0 ",
- g->verbose ? "guestfs_verbose=1 " : " ",
- g->append ? g->append : "");
-
- add_cmdline (g, "-kernel");
- add_cmdline (g, (char *) kernel);
- add_cmdline (g, "-initrd");
- add_cmdline (g, (char *) initrd);
- add_cmdline (g, "-append");
- add_cmdline (g, buf);
-
- /* Finish off the command line. */
- incr_cmdline_size (g);
- g->cmdline[g->cmdline_size-1] = NULL;
-
- if (g->verbose)
- print_cmdline (g);
-
- /* Set up stdin, stdout. */
- close (0);
- close (1);
- close (wfd[1]);
- close (rfd[0]);
-
- if (dup (wfd[0]) == -1) {
- dup_failed:
- perror ("dup failed");
- _exit (1);
- }
- if (dup (rfd[1]) == -1)
- goto dup_failed;
-
- close (wfd[0]);
- close (rfd[1]);
-
-#if 0
- /* Set up a new process group, so we can signal this process
- * and all subprocesses (eg. if qemu is really a shell script).
- */
- setpgid (0, 0);
-#endif
-
- execv (g->qemu, g->cmdline); /* Run qemu. */
- perror (g->qemu);
- _exit (1);
- }
-
- /* Parent (library). */
- g->pid = r;
-
- free (kernel);
- kernel = NULL;
- free (initrd);
- initrd = NULL;
-
- /* Fork the recovery process off which will kill qemu if the parent
- * process fails to do so (eg. if the parent segfaults).
- */
- r = fork ();
- if (r == 0) {
- pid_t qemu_pid = g->pid;
- pid_t parent_pid = getppid ();
-
- /* Writing to argv is hideously complicated and error prone. See:
- * http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/backend/utils/misc/ps_status.c?rev=1.33.2.1;content-type=text%2Fplain
- */
-
- /* Loop around waiting for one or both of the other processes to
- * disappear. It's fair to say this is very hairy. The PIDs that
- * we are looking at might be reused by another process. We are
- * effectively polling. Is the cure worse than the disease?
- */
- for (;;) {
- if (kill (qemu_pid, 0) == -1) /* qemu's gone away, we aren't needed */
- _exit (0);
- if (kill (parent_pid, 0) == -1) {
- /* Parent's gone away, qemu still around, so kill qemu. */
- kill (qemu_pid, 9);
- _exit (0);
- }
- sleep (2);
- }
- }
-
- /* Don't worry, if the fork failed, this will be -1. The recovery
- * process isn't essential.
- */
- g->recoverypid = r;
-
- /* Start the clock ... */
- time (&g->start_t);
-
- /* Close the other ends of the pipe. */
- close (wfd[0]);
- close (rfd[1]);
-
- if (fcntl (wfd[1], F_SETFL, O_NONBLOCK) == -1 ||
- fcntl (rfd[0], F_SETFL, O_NONBLOCK) == -1) {
- perrorf (g, "fcntl");
- goto cleanup1;
- }
-
- g->fd[0] = wfd[1]; /* stdin of child */
- g->fd[1] = rfd[0]; /* stdout of child */
-
- /* 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;
- }
-
- if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
- perrorf (g, "fcntl");
- goto cleanup2;
- }
-
- 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);
- }
-
- error (g, _("failed to connect to vmchannel socket"));
- goto cleanup2;
-
- 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 = recv_from_daemon (g, &size, &buf);
- free (buf);
-
- if (r == -1) return -1;
-
- if (size != GUESTFS_LAUNCH_FLAG) {
- error (g, _("guestfs_launch failed, see earlier error messages"));
- goto cleanup2;
- }
-
- /* This is possible in some really strange situations, such as
- * guestfsd starts up OK but then qemu immediately exits. Check for
- * it because the caller is probably expecting to be able to send
- * commands after this function returns.
- */
- if (g->state != READY) {
- error (g, _("qemu launched and contacted daemon, but state != READY"));
- goto cleanup2;
- }
-