- 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;
- int null_vmchannel_sock;
- char unixsock[256];
- struct sockaddr_un addr;
-
- /* Start the clock ... */
- gettimeofday (&g->launch_t, NULL);
-
-#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;
- }
-
- if (g->verbose)
- print_timestamped_message (g, "begin testing qemu features");
-
- /* Get qemu help text and version. */
- 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;
-
- 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;
- }
-
- if (listen (g->sock, 256) == -1) {
- perrorf (g, "listen");
- goto cleanup0;
- }
-
- if (getsockname (g->sock, (struct sockaddr *) &addr, &addrlen) == -1) {
- perrorf (g, "getsockname");
- goto cleanup0;
- }
-
- if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
- perrorf (g, "fcntl");
- 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 (!g->direct) {
- if (pipe (wfd) == -1 || pipe (rfd) == -1) {
- perrorf (g, "pipe");
- goto cleanup0;
- }
- }
-
- if (g->verbose)
- print_timestamped_message (g, "finished testing qemu features");
-
- r = fork ();
- if (r == -1) {
- perrorf (g, "fork");
- if (!g->direct) {
- close (wfd[0]);
- close (wfd[1]);
- close (rfd[0]);
- close (rfd[1]);
- }
- goto cleanup0;
- }
-
- 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;
-
- /* 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).
- * It is rumoured that there are versions of qemu where supplying
- * this option when hardware virtualization is not available will
- * cause qemu to fail, so we we have to check at least that
- * /dev/kvm is openable. That's not reliable, since /dev/kvm
- * might be openable by qemu but not by us (think: SELinux) in
- * which case the user would not get hardware virtualization,
- * although at least shouldn't fail. A giant clusterfuck with the
- * qemu command line, again.
- */
- if (qemu_supports (g, "-enable-kvm") &&
- is_openable (g, "/dev/kvm", O_RDWR))
- add_cmdline (g, "-enable-kvm");
-
- /* Newer versions of qemu (from around 2009/12) changed the
- * behaviour of monitors so that an implicit '-monitor stdio' is
- * assumed if we are in -nographic mode and there is no other
- * -monitor option. Only a single stdio device is allowed, so
- * this broke the '-serial stdio' option. There is a new flag
- * called -nodefaults which gets rid of all this default crud, so
- * let's use that to avoid this and any future surprises.
- */
- if (qemu_supports (g, "-nodefaults"))
- 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");
- add_cmdline (g, buf);
-
- /* Force exit instead of reboot on panic */
- add_cmdline (g, "-no-reboot");
-
- /* 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 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=10.0.2.0/8");
-
- snprintf (buf, sizeof buf,
- "guestfs_vmchannel=tcp:10.0.2.2:%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=10.0.2.0/8,"
- "guestfwd=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT
- "-chardev:guestfsvmc");
-
- add_cmdline (g, "-net");
- add_cmdline (g, buf);
-
- vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT;
- }
-
- /* Not guestfwd. HOPEFULLY this qemu uses the older -net channel
- * syntax, or if not then we'll get a quick failure.
- */
- 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=10.0.2.0/8");
-
- vmchannel = "guestfs_vmchannel=tcp:" GUESTFWD_ADDR ":" GUESTFWD_PORT;
- }
- 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 */ \
- "printk.time=1 " /* display timestamp before kernel messages */ \
- "cgroup_disable=memory " /* saves us about 5 MB of RAM */
-
- /* Linux kernel command line. */
- snprintf (buf, sizeof buf,
- LINUX_CMDLINE
- "%s " /* (selinux) */
- "%s " /* (vmchannel) */
- "%s " /* (verbose) */
- "%s", /* (append) */
- g->selinux ? "selinux=1 enforcing=0" : "selinux=0",
- vmchannel ? vmchannel : "",
- 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);
-
- if (!g->direct) {
- /* 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 (EXIT_FAILURE);
- }
- 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
-
- setenv ("LC_ALL", "C", 1);
-
- execv (g->qemu, g->cmdline); /* Run qemu. */
- perror (g->qemu);
- _exit (EXIT_FAILURE);
- }
-
- /* 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).
- */
- g->recoverypid = -1;
- if (g->recovery_proc) {
- 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 (EXIT_SUCCESS);
- if (kill (parent_pid, 0) == -1) {
- /* Parent's gone away, qemu still around, so kill qemu. */
- kill (qemu_pid, 9);
- _exit (EXIT_SUCCESS);
- }
- sleep (2);
- }
- }
-
- /* Don't worry, if the fork failed, this will be -1. The recovery
- * process isn't essential.
- */
- g->recoverypid = r;
- }
-
- if (!g->direct) {
- /* 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 */
- } else {
- g->fd[0] = open ("/dev/null", O_RDWR);
- if (g->fd[0] == -1) {
- perrorf (g, "open /dev/null");
- goto cleanup1;
- }
- g->fd[1] = dup (g->fd[0]);
- if (g->fd[1] == -1) {
- perrorf (g, "dup");
- close (g->fd[0]);
- goto cleanup1;
- }
- }
-
- 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 = 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);
- 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;
- }
-
- if (fcntl (g->sock, F_SETFL, O_NONBLOCK) == -1) {
- perrorf (g, "fcntl");
- 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);
- }
-
- error (g, _("failed to connect to vmchannel socket"));
- goto cleanup1;
-
- connected: ;