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/* virt-rescue
* Copyright (C) 2010-2012 Red Hat Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <inttypes.h>
#include <unistd.h>
#include <getopt.h>
#include <errno.h>
#include <locale.h>
#include <assert.h>
#include <libintl.h>
#include "ignore-value.h"
#include "progname.h"
#include "xvasprintf.h"
#include "guestfs.h"
#include "options.h"
static void add_scratch_disks (int n, struct drv **drvs);
static void do_suggestion (struct drv *drvs);
/* Currently open libguestfs handle. */
guestfs_h *g;
int read_only = 0;
int live = 0;
int verbose = 0;
int keys_from_stdin = 0;
int echo_keys = 0;
const char *libvirt_uri = NULL;
int inspector = 0;
static inline char *
bad_cast (char const *s)
{
return (char *) s;
}
static void __attribute__((noreturn))
usage (int status)
{
if (status != EXIT_SUCCESS)
fprintf (stderr, _("Try `%s --help' for more information.\n"),
program_name);
else {
fprintf (stdout,
_("%s: Run a rescue shell on a virtual machine\n"
"Copyright (C) 2009-2012 Red Hat Inc.\n"
"Usage:\n"
" %s [--options] -d domname\n"
" %s [--options] -a disk.img [-a disk.img ...]\n"
"Options:\n"
" -a|--add image Add image\n"
" --append kernelopts Append kernel options\n"
" -c|--connect uri Specify libvirt URI for -d option\n"
" -d|--domain guest Add disks from libvirt guest\n"
" --format[=raw|..] Force disk format for -a option\n"
" --help Display brief help\n"
" -m|--memsize MB Set memory size in megabytes\n"
" --network Enable network\n"
" -r|--ro Access read-only\n"
" --scratch[=N] Add scratch disk(s)\n"
" --selinux Enable SELinux\n"
" --smp N Enable SMP with N >= 2 virtual CPUs\n"
" --suggest Suggest mount commands for this guest\n"
" -v|--verbose Verbose messages\n"
" -V|--version Display version and exit\n"
" -w|--rw Mount read-write\n"
" -x Trace libguestfs API calls\n"
"For more information, see the manpage %s(1).\n"),
program_name, program_name, program_name,
program_name);
}
exit (status);
}
int
main (int argc, char *argv[])
{
/* Set global program name that is not polluted with libtool artifacts. */
set_program_name (argv[0]);
setlocale (LC_ALL, "");
bindtextdomain (PACKAGE, LOCALEBASEDIR);
textdomain (PACKAGE);
parse_config ();
enum { HELP_OPTION = CHAR_MAX + 1 };
static const char *options = "a:c:d:m:rvVx";
static const struct option long_options[] = {
{ "add", 1, 0, 'a' },
{ "append", 1, 0, 0 },
{ "connect", 1, 0, 'c' },
{ "domain", 1, 0, 'd' },
{ "format", 2, 0, 0 },
{ "help", 0, 0, HELP_OPTION },
{ "memsize", 1, 0, 'm' },
{ "network", 0, 0, 0 },
{ "ro", 0, 0, 'r' },
{ "rw", 0, 0, 'w' },
{ "scratch", 2, 0, 0 },
{ "selinux", 0, 0, 0 },
{ "smp", 1, 0, 0 },
{ "suggest", 0, 0, 0 },
{ "verbose", 0, 0, 'v' },
{ "version", 0, 0, 'V' },
{ 0, 0, 0, 0 }
};
struct drv *drvs = NULL;
struct drv *drv;
const char *format = NULL;
int c;
int option_index;
int network = 0;
const char *append = NULL;
char *append_full;
int memsize = 0;
int smp = 0;
int suggest = 0;
char *attach_method;
g = guestfs_create ();
if (g == NULL) {
fprintf (stderr, _("guestfs_create: failed to create handle\n"));
exit (EXIT_FAILURE);
}
argv[0] = bad_cast (program_name);
for (;;) {
c = getopt_long (argc, argv, options, long_options, &option_index);
if (c == -1) break;
switch (c) {
case 0: /* options which are long only */
if (STREQ (long_options[option_index].name, "selinux")) {
guestfs_set_selinux (g, 1);
} else if (STREQ (long_options[option_index].name, "append")) {
append = optarg;
} else if (STREQ (long_options[option_index].name, "network")) {
network = 1;
} else if (STREQ (long_options[option_index].name, "format")) {
if (!optarg || STREQ (optarg, ""))
format = NULL;
else
format = optarg;
} else if (STREQ (long_options[option_index].name, "smp")) {
if (sscanf (optarg, "%u", &smp) != 1) {
fprintf (stderr, _("%s: could not parse --smp parameter '%s'\n"),
program_name, optarg);
exit (EXIT_FAILURE);
}
if (smp < 1) {
fprintf (stderr, _("%s: --smp parameter '%s' should be >= 1\n"),
program_name, optarg);
exit (EXIT_FAILURE);
}
} else if (STREQ (long_options[option_index].name, "suggest")) {
suggest = 1;
} else if (STREQ (long_options[option_index].name, "scratch")) {
if (!optarg || STREQ (optarg, ""))
add_scratch_disks (1, &drvs);
else {
int n;
if (sscanf (optarg, "%d", &n) != 1) {
fprintf (stderr,
_("%s: could not parse --scratch parameter '%s'\n"),
program_name, optarg);
exit (EXIT_FAILURE);
}
if (n < 1) {
fprintf (stderr,
_("%s: --scratch parameter '%s' should be >= 1\n"),
program_name, optarg);
exit (EXIT_FAILURE);
}
add_scratch_disks (n, &drvs);
}
} else {
fprintf (stderr, _("%s: unknown long option: %s (%d)\n"),
program_name, long_options[option_index].name, option_index);
exit (EXIT_FAILURE);
}
break;
case 'a':
OPTION_a;
break;
case 'c':
OPTION_c;
break;
case 'd':
OPTION_d;
break;
case 'm':
if (sscanf (optarg, "%u", &memsize) != 1) {
fprintf (stderr, _("%s: could not parse memory size '%s'\n"),
program_name, optarg);
exit (EXIT_FAILURE);
}
break;
case 'r':
OPTION_r;
break;
case 'v':
OPTION_v;
break;
case 'V':
OPTION_V;
break;
case 'w':
OPTION_w;
break;
case 'x':
OPTION_x;
break;
case HELP_OPTION:
usage (EXIT_SUCCESS);
default:
usage (EXIT_FAILURE);
}
}
/* Old-style syntax? There were no -a or -d options in the old
* virt-rescue which is how we detect this.
*/
if (drvs == NULL) {
while (optind < argc) {
if (strchr (argv[optind], '/') ||
access (argv[optind], F_OK) == 0) { /* simulate -a option */
drv = calloc (1, sizeof (struct drv));
if (!drv) {
perror ("malloc");
exit (EXIT_FAILURE);
}
drv->type = drv_a;
drv->a.filename = argv[optind];
drv->next = drvs;
drvs = drv;
} else { /* simulate -d option */
drv = calloc (1, sizeof (struct drv));
if (!drv) {
perror ("malloc");
exit (EXIT_FAILURE);
}
drv->type = drv_d;
drv->d.guest = argv[optind];
drv->next = drvs;
drvs = drv;
}
optind++;
}
}
/* --suggest flag */
if (suggest) {
do_suggestion (drvs);
exit (EXIT_SUCCESS);
}
/* These are really constants, but they have to be variables for the
* options parsing code. Assert here that they have known-good
* values.
*/
assert (inspector == 0);
assert (keys_from_stdin == 0);
assert (echo_keys == 0);
assert (live == 0);
/* Must be no extra arguments on the command line. */
if (optind != argc)
usage (EXIT_FAILURE);
/* User must have specified some drives. */
if (drvs == NULL)
usage (EXIT_FAILURE);
/* Setting "direct mode" is required for the rescue appliance. */
guestfs_set_direct (g, 1);
/* The libvirt backend doesn't support direct mode. As a temporary
* workaround, force the appliance backend, but warn about it.
*/
attach_method = guestfs_get_attach_method (g);
if (attach_method) {
if (STREQ (attach_method, "libvirt") ||
STRPREFIX (attach_method, "libvirt:")) {
fprintf (stderr, _("%s: warning: virt-rescue doesn't work with the libvirt backend\n"
"at the moment. As a workaround, forcing attach-method = 'appliance'.\n"),
program_name);
guestfs_set_attach_method (g, "appliance");
}
free (attach_method);
}
/* Set other features. */
if (memsize > 0)
guestfs_set_memsize (g, memsize);
if (network)
guestfs_set_network (g, 1);
if (smp >= 1)
guestfs_set_smp (g, smp);
/* Kernel command line must include guestfs_rescue=1 (see
* appliance/init) as well as other options.
*/
append_full = xasprintf ("guestfs_rescue=1%s%s",
append ? " " : "",
append ? append : "");
guestfs_set_append (g, append_full);
free (append_full);
/* Add drives. */
add_drives (drvs, 'a');
/* Free up data structures, no longer needed after this point. */
free_drives (drvs);
/* Run the appliance. This won't return until the user quits the
* appliance.
*/
if (!verbose)
guestfs_set_error_handler (g, NULL, NULL);
/* We expect launch to fail, so ignore the return value, and don't
* bother with explicit guestfs_shutdown either.
*/
ignore_value (guestfs_launch (g));
guestfs_close (g);
exit (EXIT_SUCCESS);
}
static void suggest_filesystems (void);
static int
compare_keys_len (const void *p1, const void *p2)
{
const char *key1 = * (char * const *) p1;
const char *key2 = * (char * const *) p2;
return strlen (key1) - strlen (key2);
}
static size_t
count_strings (char *const *argv)
{
size_t i;
for (i = 0; argv[i]; ++i)
;
return i;
}
/* virt-rescue --suggest flag does a kind of inspection on the
* drives and suggests mount commands that you should use.
*/
static void
do_suggestion (struct drv *drvs)
{
char **roots;
size_t i, j;
char *type, *distro, *product_name;
int major, minor;
char **mps;
/* For inspection, force add_drives to add the drives read-only. */
read_only = 1;
/* Add drives. */
add_drives (drvs, 'a');
/* Free up data structures, no longer needed after this point. */
free_drives (drvs);
printf (_("Inspecting the virtual machine or disk image ...\n\n"));
fflush (stdout);
if (guestfs_launch (g) == -1)
exit (EXIT_FAILURE);
/* Don't use inspect_mount, since for virt-rescue we should allow
* arbitrary disks and disks with more than one OS on them. Let's
* do this using the basic API instead.
*/
roots = guestfs_inspect_os (g);
if (roots == NULL)
exit (EXIT_FAILURE);
if (roots[0] == NULL) {
suggest_filesystems ();
return;
}
printf (_("This disk contains one or more operating systems. You can use these mount\n"
"commands in virt-rescue (at the ><rescue> prompt) to mount the filesystems.\n\n"));
for (i = 0; roots[i] != NULL; ++i) {
type = guestfs_inspect_get_type (g, roots[i]);
distro = guestfs_inspect_get_distro (g, roots[i]);
product_name = guestfs_inspect_get_product_name (g, roots[i]);
major = guestfs_inspect_get_major_version (g, roots[i]);
minor = guestfs_inspect_get_minor_version (g, roots[i]);
printf (_("# %s is the root of a %s operating system\n"
"# type: %s, distro: %s, version: %d.%d\n"
"# %s\n\n"),
roots[i], type ? : "unknown",
type ? : "unknown", distro ? : "unknown", major, minor,
product_name ? : "");
mps = guestfs_inspect_get_mountpoints (g, roots[i]);
if (mps == NULL)
exit (EXIT_FAILURE);
/* Sort by key length, shortest key first, so that we end up
* mounting the filesystems in the correct order.
*/
qsort (mps, count_strings (mps) / 2, 2 * sizeof (char *),
compare_keys_len);
for (j = 0; mps[j] != NULL; j += 2) {
printf ("mount %s /sysroot%s\n", mps[j+1], mps[j]);
free (mps[j]);
free (mps[j+1]);
}
/* If it's Linux, print the bind-mounts. */
if (type && STREQ (type, "linux")) {
printf ("mount --bind /dev /sysroot/dev\n");
printf ("mount --bind /dev/pts /sysroot/dev/pts\n");
printf ("mount --bind /proc /sysroot/proc\n");
printf ("mount --bind /sys /sysroot/sys\n");
}
printf ("\n");
free (type);
free (distro);
free (product_name);
free (roots[i]);
}
free (roots);
}
/* Inspection failed, so it doesn't contain any OS that we recognise.
* However there might still be filesystems so print some suggestions
* for those.
*/
static void
suggest_filesystems (void)
{
char **fses;
size_t i;
fses = guestfs_list_filesystems (g);
if (fses == NULL)
exit (EXIT_FAILURE);
if (fses[0] == NULL) {
printf (_("This disk contains no filesystems that we recognize.\n\n"
"However you can still use virt-rescue on the disk image, to try to mount\n"
"filesystems that are not recognized by libguestfs, or to create partitions,\n"
"logical volumes and filesystems on a blank disk.\n"));
return;
}
printf (_("This disk contains one or more filesystems, but we don't recognize any\n"
"operating system. You can use these mount commands in virt-rescue (at the\n"
"><rescue> prompt) to mount these filesystems.\n\n"));
for (i = 0; fses[i] != NULL; i += 2) {
printf (_("# %s has type '%s'\n"), fses[i], fses[i+1]);
if (STRNEQ (fses[i+1], "swap") && STRNEQ (fses[i+1], "unknown"))
printf ("mount %s /sysroot\n", fses[i]);
printf ("\n");
free (fses[i]);
free (fses[i+1]);
}
free (fses);
}
struct scratch_disk {
struct scratch_disk *next;
char *filename;
};
static struct scratch_disk *scratch_disks = NULL;
static void unlink_scratch_disks (void);
static void add_scratch_disk (struct drv **drvs);
static void
add_scratch_disks (int n, struct drv **drvs)
{
while (n > 0) {
add_scratch_disk (drvs);
n--;
}
}
static void
add_scratch_disk (struct drv **drvs)
{
char filename_s[] = "/var/tmp/rescueXXXXXX";
int fd;
char *filename;
struct scratch_disk *sd;
struct drv *drv;
/* Create a temporary file, raw sparse format. */
fd = mkstemp (filename_s);
if (fd == -1) {
perror ("mkstemp: scratch disk");
exit (EXIT_FAILURE);
}
if (ftruncate (fd, 10737418240ULL) == -1) {
perror ("ftruncate: scratch disk");
exit (EXIT_FAILURE);
}
if (close (fd) == -1) {
perror ("close: scratch disk");
exit (EXIT_FAILURE);
}
filename = strdup (filename_s);
if (filename == NULL) {
perror ("malloc");
exit (EXIT_FAILURE);
}
/* Remember this scratch disk, so we can clean it up at exit. */
if (scratch_disks == NULL)
atexit (unlink_scratch_disks);
sd = malloc (sizeof (struct scratch_disk));
if (!sd) {
perror ("malloc");
exit (EXIT_FAILURE);
}
sd->filename = filename;
sd->next = scratch_disks;
scratch_disks = sd;
/* Add the scratch disk to the drives list. */
drv = calloc (1, sizeof (struct drv));
if (!drv) {
perror ("malloc");
exit (EXIT_FAILURE);
}
drv->type = drv_a;
drv->nr_drives = -1;
drv->a.filename = filename;
drv->a.format = "raw";
drv->next = *drvs;
*drvs = drv;
}
/* Called atexit to unlink the scratch disks. */
static void
unlink_scratch_disks (void)
{
while (scratch_disks) {
unlink (scratch_disks->filename);
free (scratch_disks->filename);
scratch_disks = scratch_disks->next;
}
}
/* The following was a nice idea, but in fact it doesn't work. This is
* because qemu has some (broken) pty emulation itself.
*/
#if 0
int fd_m, fd_s, r;
pid_t pid;
struct termios tsorig, tsnew;
/* Set up pty. */
fd_m = posix_openpt (O_RDWR);
if (fd_m == -1) {
perror ("posix_openpt");
exit (EXIT_FAILURE);
}
r = grantpt (fd_m);
if (r == -1) {
perror ("grantpt");
exit (EXIT_FAILURE);
}
r = unlockpt (fd_m);
if (r == -1) {
perror ("unlockpt");
exit (EXIT_FAILURE);
}
fd_s = open (ptsname (fd_m), O_RDWR);
if (fd_s == -1) {
perror ("open ptsname");
exit (EXIT_FAILURE);
}
pid = fork ();
if (pid == -1) {
perror ("fork");
exit (EXIT_FAILURE);
}
if (pid == 0) {
/* Child process. */
#if 1
/* Set raw mode. */
r = tcgetattr (fd_s, &tsorig);
tsnew = tsorig;
cfmakeraw (&tsnew);
tcsetattr (fd_s, TCSANOW, &tsnew);
#endif
/* Close the master side of pty and set slave side as
* stdin/stdout/stderr.
*/
close (fd_m);
close (0);
close (1);
close (2);
if (dup (fd_s) == -1 || dup (fd_s) == -1 || dup (fd_s) == -1) {
perror ("dup");
exit (EXIT_FAILURE);
}
close (fd_s);
#if 1
if (setsid () == -1)
perror ("warning: failed to setsid");
if (ioctl (0, TIOCSCTTY, 0) == -1)
perror ("warning: failed to TIOCSCTTY");
#endif
/* Run the appliance. This won't return until the user quits the
* appliance.
*/
guestfs_set_error_handler (g, NULL, NULL);
r = guestfs_launch (g);
/* launch() expects guestfsd to start. However, virt-rescue doesn't
* run guestfsd, so this will always fail with ECHILD when the
* appliance exits unexpectedly.
*/
if (errno != ECHILD) {
fprintf (stderr, "%s: %s\n", program_name, guestfs_last_error (g));
guestfs_close (g);
exit (EXIT_FAILURE);
}
guestfs_close (g);
_exit (EXIT_SUCCESS);
}
/* Parent process continues ... */
/* Close slave side of pty. */
close (fd_s);
/* Set raw mode. */
r = tcgetattr (fd_s, &tsorig);
tsnew = tsorig;
cfmakeraw (&tsnew);
tcsetattr (fd_s, TCSANOW, &tsnew);
/* Send input and output to master side of pty. */
r = multiplex (fd_m);
tcsetattr (fd_s, TCSANOW, &tsorig); /* Restore cooked mode. */
if (r == -1)
exit (EXIT_FAILURE);
if (waitpid (pid, &r, 0) == -1) {
perror ("waitpid");
exit (EXIT_FAILURE);
}
if (!WIFEXITED (r)) {
/* abnormal child exit */
fprintf (stderr, _("%s: unknown child exit status (%d)\n"),
program_name, r);
exit (EXIT_FAILURE);
}
else
exit (WEXITSTATUS (r)); /* normal exit, return child process's status */
}
/* Naive and simple multiplex function. */
static int
multiplex (int fd_m)
{
int r, eof_stdin = 0;
fd_set rfds, wfds;
char tobuf[BUFSIZ], frombuf[BUFSIZ]; /* to/from slave */
size_t tosize = 0, fromsize = 0;
ssize_t n;
size_t count;
long flags_0, flags_1, flags_fd_m;
flags_0 = fcntl (0, F_GETFL);
fcntl (0, F_SETFL, O_NONBLOCK | flags_0);
flags_1 = fcntl (0, F_GETFL);
fcntl (1, F_SETFL, O_NONBLOCK | flags_1);
flags_fd_m = fcntl (0, F_GETFL);
fcntl (fd_m, F_SETFL, O_NONBLOCK | flags_fd_m);
for (;;) {
FD_ZERO (&rfds);
FD_ZERO (&wfds);
/* Still space in to-buffer? If so, we can read from the user. */
if (!eof_stdin && tosize < BUFSIZ)
FD_SET (0, &rfds);
/* Still space in from-buffer? If so, we can read from the slave. */
if (fromsize < BUFSIZ)
FD_SET (fd_m, &rfds);
/* Content in to-buffer? If so, we want to write to the slave. */
if (tosize > 0)
FD_SET (fd_m, &wfds);
/* Content in from-buffer? If so, we want to write to the user. */
if (fromsize > 0)
FD_SET (1, &wfds);
r = select (fd_m+1, &rfds, &wfds, NULL, NULL);
if (r == -1) {
if (errno == EAGAIN || errno == EINTR)
continue;
perror ("select");
return -1;
}
/* Input from user: Put it in the to-buffer. */
if (FD_ISSET (0, &rfds)) {
count = BUFSIZ - tosize;
n = read (0, &tobuf[tosize], count);
if (n == -1) {
perror ("read");
return -1;
}
if (n == 0) { /* stdin was closed */
eof_stdin = 1;
/* This is what telnetd does ... */
tobuf[tosize] = '\004';
tosize += 1;
} else
tosize += n;
}
/* Input from slave: Put it in the from-buffer. */
if (FD_ISSET (fd_m, &rfds)) {
count = BUFSIZ - fromsize;
n = read (fd_m, &frombuf[fromsize], count);
if (n == -1) {
if (errno != EIO) /* EIO if slave process dies */
perror ("read");
break;
}
if (n == 0) /* slave closed the connection */
break;
fromsize += n;
}
/* Can write to user. */
if (FD_ISSET (1, &wfds)) {
n = write (1, frombuf, fromsize);
if (n == -1) {
perror ("write");
return -1;
}
memmove (frombuf, &frombuf[n], BUFSIZ - n);
fromsize -= n;
}
/* Can write to slave. */
if (FD_ISSET (fd_m, &wfds)) {
n = write (fd_m, tobuf, tosize);
if (n == -1) {
perror ("write");
return -1;
}
memmove (tobuf, &tobuf[n], BUFSIZ - n);
tosize -= n;
}
} /* for (;;) */
/* We end up here when slave has closed the connection. */
close (fd_m);
/* Restore blocking behaviour. */
fcntl (1, F_SETFL, flags_1);
/* Last chance to write out any remaining data in the buffers, but
* don't bother about errors.
*/
ignore_value (write (1, frombuf, fromsize));
return 0;
}
#endif
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