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.
43 #if ENABLE_DEBUG_COMMAND
46 char * (*f) (const char *subcmd, int argc, char *const *const argv);
49 static char *debug_help (const char *subcmd, int argc, char *const *const argv);
50 static char *debug_env (const char *subcmd, int argc, char *const *const argv);
51 static char *debug_fds (const char *subcmd, int argc, char *const *const argv);
52 static char *debug_ls (const char *subcmd, int argc, char *const *const argv);
53 static char *debug_ll (const char *subcmd, int argc, char *const *const argv);
54 static char *debug_segv (const char *subcmd, int argc, char *const *const argv);
55 static char *debug_sh (const char *subcmd, int argc, char *const *const argv);
56 static char *debug_core_pattern (const char *subcmd, int argc, char *const *const argv);
58 static struct cmd cmds[] = {
59 { "help", debug_help },
60 { "core_pattern", debug_core_pattern },
65 { "segv", debug_segv },
71 #if ! ENABLE_DEBUG_COMMAND
72 # define MAYBE_UNUSED ATTRIBUTE_UNUSED
74 # define MAYBE_UNUSED /* empty */
78 do_debug (const char *subcmd MAYBE_UNUSED, char *const *argv MAYBE_UNUSED)
80 #if ENABLE_DEBUG_COMMAND
83 for (i = argc = 0; argv[i] != NULL; ++i)
86 for (i = 0; cmds[i].cmd != NULL; ++i) {
87 if (STRCASEEQ (subcmd, cmds[i].cmd))
88 return cmds[i].f (subcmd, argc, argv);
91 reply_with_error ("use 'debug help' to list the supported commands");
94 reply_with_error ("guestfsd was not configured with --enable-debug-command");
99 #if ENABLE_DEBUG_COMMAND
101 debug_help (const char *subcmd, int argc, char *const *const argv)
106 r = strdup ("Commands supported:");
108 reply_with_perror ("strdup");
113 for (i = 0; cmds[i].cmd != NULL; ++i) {
114 len += strlen (cmds[i].cmd) + 1; /* space + new command */
115 p = realloc (r, len + 1); /* +1 for the final NUL */
117 reply_with_perror ("realloc");
124 strcat (r, cmds[i].cmd);
132 debug_fds (const char *subcmd, int argc, char *const *const argv)
140 char fname[256], link[256];
143 fp = open_memstream (&out, &size);
145 reply_with_perror ("open_memstream");
149 dir = opendir ("/proc/self/fd");
151 reply_with_perror ("opendir: /proc/self/fd");
156 while ((d = readdir (dir)) != NULL) {
157 if (STREQ (d->d_name, ".") || STREQ (d->d_name, ".."))
160 snprintf (fname, sizeof fname, "/proc/self/fd/%s", d->d_name);
162 r = lstat (fname, &statbuf);
164 reply_with_perror ("stat: %s", fname);
171 if (S_ISLNK (statbuf.st_mode)) {
172 r = readlink (fname, link, sizeof link - 1);
174 reply_with_perror ("readline: %s", fname);
182 fprintf (fp, "%2s %s\n", d->d_name, link);
184 fprintf (fp, "%2s 0%o\n", d->d_name, statbuf.st_mode);
189 if (closedir (dir) == -1) {
190 reply_with_perror ("closedir");
198 /* Force a segfault in the daemon. */
200 debug_segv (const char *subcmd, int argc, char *const *const argv)
206 /* Run an arbitrary shell command using /bin/sh from the appliance.
208 * Note this is somewhat different from the ordinary guestfs_sh command
209 * because it's not using the guest shell, and is not chrooted.
212 debug_sh (const char *subcmd, int argc, char *const *const argv)
215 reply_with_error ("sh: expecting a command to run");
222 /* guestfish splits the parameter(s) into a list of strings,
223 * and we have to reassemble them here. Not ideal. XXX
225 for (i = len = 0; i < argc; ++i)
226 len += strlen (argv[i]) + 1;
229 reply_with_perror ("malloc");
232 for (i = j = 0; i < argc; ++i) {
233 len = strlen (argv[i]);
234 memcpy (&cmd[j], argv[i], len);
241 /* Set up some environment variables. */
242 setenv ("root", sysroot, 1);
243 if (access ("/sys/block/sda", F_OK) == 0)
244 setenv ("sd", "sd", 1);
245 else if (access ("/sys/block/hda", F_OK) == 0)
246 setenv ("sd", "hd", 1);
247 else if (access ("/sys/block/vda", F_OK) == 0)
248 setenv ("sd", "vd", 1);
251 int r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
252 "/bin/sh", "-c", cmd, NULL);
256 reply_with_error ("%s", err);
264 /* Print the environment that commands get (by running external printenv). */
266 debug_env (const char *subcmd, int argc, char *const *const argv)
271 r = command (&out, &err, "printenv", NULL);
273 reply_with_error ("printenv: %s", err);
284 /* List files in the appliance. */
286 debug_ls (const char *subcmd, int argc, char *const *const argv)
288 int len = count_strings (argv);
289 const char *cargv[len+3];
294 for (i = 0; i < len; ++i)
295 cargv[2+i] = argv[i];
301 r = commandv (&out, &err, (void *) cargv);
303 reply_with_error ("ls: %s", err);
314 /* List files in the appliance. */
316 debug_ll (const char *subcmd, int argc, char *const *const argv)
318 int len = count_strings (argv);
319 const char *cargv[len+3];
324 for (i = 0; i < len; ++i)
325 cargv[2+i] = argv[i];
331 r = commandv (&out, &err, (void *) cargv);
333 reply_with_error ("ll: %s", err);
344 /* Enable core dumping to the given core pattern.
345 * Note that this pattern is relative to any chroot of the process which
346 * crashes. This means that if you want to write the core file to the guest's
347 * storage the pattern must start with /sysroot only if the command which
348 * crashes doesn't chroot.
351 debug_core_pattern (const char *subcmd, int argc, char *const *const argv)
354 reply_with_error ("core_pattern: expecting a core pattern");
358 const char *pattern = argv[0];
359 const size_t pattern_len = strlen(pattern);
361 #define CORE_PATTERN "/proc/sys/kernel/core_pattern"
362 int fd = open (CORE_PATTERN, O_WRONLY);
364 reply_with_perror ("open: " CORE_PATTERN);
367 if (write (fd, pattern, pattern_len) < (ssize_t) pattern_len) {
368 reply_with_perror ("write: " CORE_PATTERN);
371 if (close (fd) == -1) {
372 reply_with_perror ("close: " CORE_PATTERN);
376 struct rlimit limit = {
377 .rlim_cur = RLIM_INFINITY,
378 .rlim_max = RLIM_INFINITY
380 if (setrlimit (RLIMIT_CORE, &limit) == -1) {
381 reply_with_perror ("setrlimit (RLIMIT_CORE)");
385 char *ret = strdup ("ok");
387 reply_with_perror ("strdup");
394 #endif /* ENABLE_DEBUG_COMMAND */
396 #if ENABLE_DEBUG_COMMAND
398 write_cb (void *fd_ptr, const void *buf, size_t len)
400 int fd = *(int *)fd_ptr;
401 return xwrite (fd, buf, len);
405 /* Has one FileIn parameter. */
407 do_debug_upload (const char *filename MAYBE_UNUSED, int mode MAYBE_UNUSED)
409 #if ENABLE_DEBUG_COMMAND
410 /* Not chrooted - this command lets you upload a file to anywhere
413 int fd = open (filename, O_WRONLY|O_CREAT|O_TRUNC|O_NOCTTY, mode);
419 reply_with_perror ("%s", filename);
423 int r = receive_file (write_cb, &fd);
424 if (r == -1) { /* write error */
428 reply_with_error ("write error: %s", filename);
432 if (r == -2) { /* cancellation from library */
434 /* Do NOT send any error. */
438 if (close (fd) == -1) {
440 if (r == -1) /* if r == 0, file transfer ended already */
443 reply_with_perror ("close: %s", filename);
449 reply_with_error ("guestfsd was not configured with --enable-debug-command");