1 /* libguestfs - the guestfsd daemon
2 * Copyright (C) 2009 Red Hat Inc.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <sys/types.h>
29 #include <sys/resource.h>
31 #include "../src/guestfs_protocol.h"
35 /* This command exposes debugging information, internals and
36 * status. There is no comprehensive documentation for this
37 * command. You have to look at the source code in this file
38 * to find out what you can do.
40 * Commands always output a freeform string.
42 * Since libguestfs 1.5.7, the debug command has been enabled
43 * by default for all builds (previously you had to enable it
44 * in configure). This command is not part of the stable ABI
45 * and may change at any time.
50 char * (*f) (const char *subcmd, int argc, char *const *const argv);
53 static char *debug_help (const char *subcmd, int argc, char *const *const argv);
54 static char *debug_env (const char *subcmd, int argc, char *const *const argv);
55 static char *debug_fds (const char *subcmd, int argc, char *const *const argv);
56 static char *debug_ls (const char *subcmd, int argc, char *const *const argv);
57 static char *debug_ll (const char *subcmd, int argc, char *const *const argv);
58 static char *debug_segv (const char *subcmd, int argc, char *const *const argv);
59 static char *debug_sh (const char *subcmd, int argc, char *const *const argv);
60 static char *debug_core_pattern (const char *subcmd, int argc, char *const *const argv);
62 static struct cmd cmds[] = {
63 { "help", debug_help },
64 { "core_pattern", debug_core_pattern },
69 { "segv", debug_segv },
75 do_debug (const char *subcmd, char *const *argv)
79 for (i = argc = 0; argv[i] != NULL; ++i)
82 for (i = 0; cmds[i].cmd != NULL; ++i) {
83 if (STRCASEEQ (subcmd, cmds[i].cmd))
84 return cmds[i].f (subcmd, argc, argv);
87 reply_with_error ("use 'debug help' to list the supported commands");
92 debug_help (const char *subcmd, int argc, char *const *const argv)
97 r = strdup ("Commands supported:");
99 reply_with_perror ("strdup");
104 for (i = 0; cmds[i].cmd != NULL; ++i) {
105 len += strlen (cmds[i].cmd) + 1; /* space + new command */
106 p = realloc (r, len + 1); /* +1 for the final NUL */
108 reply_with_perror ("realloc");
115 strcat (r, cmds[i].cmd);
123 debug_fds (const char *subcmd, int argc, char *const *const argv)
131 char fname[256], link[256];
134 fp = open_memstream (&out, &size);
136 reply_with_perror ("open_memstream");
140 dir = opendir ("/proc/self/fd");
142 reply_with_perror ("opendir: /proc/self/fd");
147 while ((d = readdir (dir)) != NULL) {
148 if (STREQ (d->d_name, ".") || STREQ (d->d_name, ".."))
151 snprintf (fname, sizeof fname, "/proc/self/fd/%s", d->d_name);
153 r = lstat (fname, &statbuf);
155 reply_with_perror ("stat: %s", fname);
162 if (S_ISLNK (statbuf.st_mode)) {
163 r = readlink (fname, link, sizeof link - 1);
165 reply_with_perror ("readline: %s", fname);
173 fprintf (fp, "%2s %s\n", d->d_name, link);
175 fprintf (fp, "%2s 0%o\n", d->d_name, statbuf.st_mode);
180 if (closedir (dir) == -1) {
181 reply_with_perror ("closedir");
189 /* Force a segfault in the daemon. */
191 debug_segv (const char *subcmd, int argc, char *const *const argv)
197 /* Run an arbitrary shell command using /bin/sh from the appliance.
199 * Note this is somewhat different from the ordinary guestfs_sh command
200 * because it's not using the guest shell, and is not chrooted.
203 debug_sh (const char *subcmd, int argc, char *const *const argv)
206 reply_with_error ("sh: expecting a command to run");
213 /* guestfish splits the parameter(s) into a list of strings,
214 * and we have to reassemble them here. Not ideal. XXX
216 for (i = len = 0; i < argc; ++i)
217 len += strlen (argv[i]) + 1;
220 reply_with_perror ("malloc");
223 for (i = j = 0; i < argc; ++i) {
224 len = strlen (argv[i]);
225 memcpy (&cmd[j], argv[i], len);
232 /* Set up some environment variables. */
233 setenv ("root", sysroot, 1);
234 if (access ("/sys/block/sda", F_OK) == 0)
235 setenv ("sd", "sd", 1);
236 else if (access ("/sys/block/hda", F_OK) == 0)
237 setenv ("sd", "hd", 1);
238 else if (access ("/sys/block/vda", F_OK) == 0)
239 setenv ("sd", "vd", 1);
242 int r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
243 "/bin/sh", "-c", cmd, NULL);
247 reply_with_error ("%s", err);
255 /* Print the environment that commands get (by running external printenv). */
257 debug_env (const char *subcmd, int argc, char *const *const argv)
262 r = command (&out, &err, "printenv", NULL);
264 reply_with_error ("printenv: %s", err);
275 /* List files in the appliance. */
277 debug_ls (const char *subcmd, int argc, char *const *const argv)
279 int len = count_strings (argv);
280 const char *cargv[len+3];
285 for (i = 0; i < len; ++i)
286 cargv[2+i] = argv[i];
292 r = commandv (&out, &err, (void *) cargv);
294 reply_with_error ("ls: %s", err);
305 /* List files in the appliance. */
307 debug_ll (const char *subcmd, int argc, char *const *const argv)
309 int len = count_strings (argv);
310 const char *cargv[len+3];
315 for (i = 0; i < len; ++i)
316 cargv[2+i] = argv[i];
322 r = commandv (&out, &err, (void *) cargv);
324 reply_with_error ("ll: %s", err);
335 /* Enable core dumping to the given core pattern.
336 * Note that this pattern is relative to any chroot of the process which
337 * crashes. This means that if you want to write the core file to the guest's
338 * storage the pattern must start with /sysroot only if the command which
339 * crashes doesn't chroot.
342 debug_core_pattern (const char *subcmd, int argc, char *const *const argv)
345 reply_with_error ("core_pattern: expecting a core pattern");
349 const char *pattern = argv[0];
350 const size_t pattern_len = strlen(pattern);
352 #define CORE_PATTERN "/proc/sys/kernel/core_pattern"
353 int fd = open (CORE_PATTERN, O_WRONLY);
355 reply_with_perror ("open: " CORE_PATTERN);
358 if (write (fd, pattern, pattern_len) < (ssize_t) pattern_len) {
359 reply_with_perror ("write: " CORE_PATTERN);
362 if (close (fd) == -1) {
363 reply_with_perror ("close: " CORE_PATTERN);
367 struct rlimit limit = {
368 .rlim_cur = RLIM_INFINITY,
369 .rlim_max = RLIM_INFINITY
371 if (setrlimit (RLIMIT_CORE, &limit) == -1) {
372 reply_with_perror ("setrlimit (RLIMIT_CORE)");
376 char *ret = strdup ("ok");
378 reply_with_perror ("strdup");
386 write_cb (void *fd_ptr, const void *buf, size_t len)
388 int fd = *(int *)fd_ptr;
389 return xwrite (fd, buf, len);
392 /* Has one FileIn parameter. */
394 do_debug_upload (const char *filename, int mode)
396 /* Not chrooted - this command lets you upload a file to anywhere
399 int fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, mode);
405 reply_with_perror ("%s", filename);
409 int r = receive_file (write_cb, &fd);
410 if (r == -1) { /* write error */
414 reply_with_error ("write error: %s", filename);
418 if (r == -2) { /* cancellation from library */
420 /* Do NOT send any error. */
424 if (close (fd) == -1) {
426 if (r == -1) /* if r == 0, file transfer ended already */
429 reply_with_perror ("close: %s", filename);