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.
21 #define _BSD_SOURCE /* for daemon(3) */
27 #include <rpc/types.h>
31 #include <sys/param.h>
32 #include <sys/select.h>
33 #include <sys/types.h>
41 static void usage (void);
43 /* Also in guestfs.c */
44 #define VMCHANNEL_PORT "6666"
45 #define VMCHANNEL_ADDR "10.0.2.4"
50 main (int argc, char *argv[])
52 static const char *options = "fh:p:?";
53 static struct option long_options[] = {
54 { "foreground", 0, 0, 'f' },
55 { "help", 0, 0, '?' },
56 { "host", 1, 0, 'h' },
57 { "port", 1, 0, 'p' },
62 const char *host = NULL;
63 const char *port = NULL;
68 struct addrinfo *res, *rr;
69 struct addrinfo hints;
75 c = getopt_long (argc, argv, options, long_options, NULL);
96 fprintf (stderr, "guestfsd: unexpected command line option 0x%x\n", c);
106 /* If host and port aren't set yet, try /proc/cmdline. */
107 if (!host || !port) {
108 fp = fopen ("/proc/cmdline", "r");
110 perror ("/proc/cmdline");
113 n = fread (buf, 1, sizeof buf - 1, fp);
117 /* Set the verbose flag. Not quite right because this will only
118 * set the flag if host and port aren't set on the command line.
119 * Don't worry about this for now. (XXX)
121 verbose = strstr (buf, "guestfs_verbose=1") != NULL;
123 printf ("verbose daemon enabled\n");
125 p = strstr (buf, "guestfs=");
129 p2 = strchr (p, ':');
133 r = strcspn (p2, " \n");
141 /* Can't parse /proc/cmdline, so use built-in defaults. */
142 if (!host || !port) {
143 host = VMCHANNEL_ADDR;
144 port = VMCHANNEL_PORT;
147 /* Make sure SIGPIPE doesn't kill us. */
148 memset (&sa, 0, sizeof sa);
149 sa.sa_handler = SIG_IGN;
151 if (sigaction (SIGPIPE, &sa, NULL) == -1)
152 perror ("sigaction SIGPIPE"); /* but try to continue anyway ... */
154 /* Set up a basic environment. After we are called by /init the
155 * environment is essentially empty.
156 * https://bugzilla.redhat.com/show_bug.cgi?id=502074#c5
158 setenv ("PATH", "/usr/bin:/bin", 1);
159 setenv ("SHELL", "/bin/sh", 1);
160 setenv ("LANG", "C", 1);
162 /* Resolve the hostname. */
163 memset (&hints, 0, sizeof hints);
164 hints.ai_socktype = SOCK_STREAM;
165 hints.ai_flags = AI_ADDRCONFIG;
166 r = getaddrinfo (host, port, &hints, &res);
168 fprintf (stderr, "%s:%s: %s\n", host, port, gai_strerror (r));
172 /* Connect to the given TCP socket. */
174 for (rr = res; rr != NULL; rr = rr->ai_next) {
175 sock = socket (rr->ai_family, rr->ai_socktype, rr->ai_protocol);
177 if (connect (sock, rr->ai_addr, rr->ai_addrlen) == 0)
188 fprintf (stderr, "connection to %s:%s failed\n", host, port);
192 /* Send the magic length message which indicates that
193 * userspace is up inside the guest.
195 len = GUESTFS_LAUNCH_FLAG;
196 xdrmem_create (&xdr, buf, sizeof buf, XDR_ENCODE);
197 if (!xdr_uint32_t (&xdr, &len)) {
198 fprintf (stderr, "xdr_uint32_t failed\n");
202 (void) xwrite (sock, buf, xdr_getpos (&xdr));
206 /* Fork into the background. */
208 if (daemon (0, 1) == -1) {
214 /* Enter the main loop, reading and performing actions. */
221 xwrite (int sock, const void *buf, size_t len)
226 r = write (sock, buf, len);
239 xread (int sock, void *buf, size_t len)
244 r = read (sock, buf, len);
250 fprintf (stderr, "read: unexpected end of file on fd %d\n", sock);
263 fprintf (stderr, "guestfsd [-f] [-h host -p port]\n");
267 add_string (char ***argv, int *size, int *alloc, const char *str)
272 if (*size >= *alloc) {
274 new_argv = realloc (*argv, *alloc * sizeof (char *));
275 if (new_argv == NULL) {
276 reply_with_perror ("realloc");
277 free_strings (*argv);
284 new_str = strdup (str);
285 if (new_str == NULL) {
286 reply_with_perror ("strdup");
287 free_strings (*argv);
292 (*argv)[*size] = new_str;
299 count_strings (char * const* const argv)
303 for (argc = 0; argv[argc] != NULL; ++argc)
309 compare (const void *vp1, const void *vp2)
311 char * const *p1 = (char * const *) vp1;
312 char * const *p2 = (char * const *) vp2;
313 return strcmp (*p1, *p2);
317 sort_strings (char **argv, int len)
319 qsort (argv, len, sizeof (char *), compare);
323 free_strings (char **argv)
327 for (argc = 0; argv[argc] != NULL; ++argc)
333 free_stringslen (char **argv, int len)
337 for (i = 0; i < len; ++i)
342 /* This is a more sane version of 'system(3)' for running external
343 * commands. It uses fork/execvp, so we don't need to worry about
344 * quoting of parameters, and it allows us to capture any error
345 * messages in a buffer.
348 command (char **stdoutput, char **stderror, const char *name, ...)
355 /* Collect the command line arguments into an array. */
357 argv = malloc (sizeof (char *) * i);
362 argv[0] = (char *) name;
365 va_start (args, name);
367 while ((s = va_arg (args, char *)) != NULL) {
368 p = realloc (argv, sizeof (char *) * (++i));
382 r = commandv (stdoutput, stderror, argv);
384 /* NB: Mustn't free the strings which are on the stack. */
390 /* Same as 'command', but we allow the status code from the
391 * subcommand to be non-zero, and return that status code.
392 * We still return -1 if there was some other error.
395 commandr (char **stdoutput, char **stderror, const char *name, ...)
402 /* Collect the command line arguments into an array. */
404 argv = malloc (sizeof (char *) * i);
409 argv[0] = (char *) name;
412 va_start (args, name);
414 while ((s = va_arg (args, char *)) != NULL) {
415 p = realloc (argv, sizeof (char *) * (++i));
429 r = commandrv (stdoutput, stderror, argv);
431 /* NB: Mustn't free the strings which are on the stack. */
437 /* Same as 'command', but passing an argv. */
439 commandv (char **stdoutput, char **stderror, char * const* const argv)
443 r = commandrv (stdoutput, stderror, argv);
451 commandrv (char **stdoutput, char **stderror, char * const* const argv)
453 int so_size = 0, se_size = 0;
454 int so_fd[2], se_fd[2];
460 if (stdoutput) *stdoutput = NULL;
461 if (stderror) *stderror = NULL;
464 printf ("%s", argv[0]);
465 for (i = 1; argv[i] != NULL; ++i)
466 printf (" %s", argv[i]);
470 if (pipe (so_fd) == -1 || pipe (se_fd) == -1) {
485 if (pid == 0) { /* Child process. */
494 execvp (argv[0], argv);
499 /* Parent process. */
504 FD_SET (so_fd[0], &rset);
505 FD_SET (se_fd[0], &rset);
510 r = select (MAX (so_fd[0], se_fd[0]) + 1, &rset2, NULL, NULL, NULL);
514 if (stdoutput) free (*stdoutput);
515 if (stderror) free (*stderror);
518 waitpid (pid, NULL, 0);
522 if (FD_ISSET (so_fd[0], &rset2)) { /* something on stdout */
523 r = read (so_fd[0], buf, sizeof buf);
528 if (r == 0) { FD_CLR (so_fd[0], &rset); quit++; }
530 if (r > 0 && stdoutput) {
532 p = realloc (*stdoutput, so_size);
538 memcpy (*stdoutput + so_size - r, buf, r);
542 if (FD_ISSET (se_fd[0], &rset2)) { /* something on stderr */
543 r = read (se_fd[0], buf, sizeof buf);
548 if (r == 0) { FD_CLR (se_fd[0], &rset); quit++; }
550 if (r > 0 && stderror) {
552 p = realloc (*stderror, se_size);
558 memcpy (*stderror + se_size - r, buf, r);
566 /* Make sure the output buffers are \0-terminated. Also remove any
567 * trailing \n characters from the error buffer (not from stdout).
570 *stdoutput = realloc (*stdoutput, so_size+1);
571 if (*stdoutput == NULL) {
575 (*stdoutput)[so_size] = '\0';
578 *stderror = realloc (*stderror, se_size+1);
579 if (*stderror == NULL) {
583 (*stderror)[se_size] = '\0';
585 while (se_size >= 0 && (*stderror)[se_size] == '\n')
586 (*stderror)[se_size--] = '\0';
590 /* Get the exit status of the command. */
591 waitpid (pid, &r, 0);
594 return WEXITSTATUS (r);
599 /* Split an output string into a NULL-terminated list of lines.
600 * Typically this is used where we have run an external command
601 * which has printed out a list of things, and we want to return
604 * The corner cases here are quite tricky. Note in particular:
608 * "a\nb" -> ["a"; "b"]
609 * "a\nb\n" -> ["a"; "b"]
610 * "a\nb\n\n" -> ["a"; "b"; ""]
612 * The original string is written over and destroyed by this
613 * function (which is usually OK because it's the 'out' string
614 * from command()). You can free the original string, because
615 * add_string() strdups the strings.
618 split_lines (char *str)
621 int size = 0, alloc = 0;
624 if (strcmp (str, "") == 0)
629 /* Empty last line? */
633 pend = strchr (p, '\n');
639 if (add_string (&lines, &size, &alloc, p) == -1) {
647 if (add_string (&lines, &size, &alloc, NULL) == -1)
653 /* Quote 'in' for the shell, and write max len-1 bytes to out. The
654 * result will be NUL-terminated, even if it is truncated.
656 * Returns number of bytes needed, so if result >= len then the buffer
657 * should have been longer.
659 * XXX This doesn't quote \n correctly (but is still safe).
662 shell_quote (char *out, int len, const char *in)
664 #define SAFE(c) (isalnum((c)) || \
665 (c) == '/' || (c) == '-' || (c) == '_' || (c) == '.')
667 int outlen = strlen (in);
669 /* Calculate how much output space this really needs. */
670 for (i = 0; in[i]; ++i)
671 if (!SAFE (in[i])) outlen++;
673 /* Now copy the string, but only up to len-1 bytes. */
674 for (i = 0, j = 0; in[i]; ++i) {
675 int is_safe = SAFE (in[i]);
677 /* Enough space left to write this character? */
678 if (j >= len-1 || (!is_safe && j >= len-2))
681 if (!is_safe) out[j++] = '\\';
690 /* Perform device name translation. Don't call this directly -
691 * use the IS_DEVICE macro.
693 * See guestfs(3) for the algorithm.
696 device_name_translation (char *device, const char *func)
700 if (stat (device, &statbuf) == -1) {
701 /* If the name begins with "/dev/sd" then try the alternatives. */
702 if (strncmp (device, "/dev/sd", 7) != 0)
705 device[5] = 'h'; /* /dev/hd (old IDE driver) */
706 if (stat (device, &statbuf) == 0)
709 device[5] = 'v'; /* /dev/vd (for virtio devices) */
710 if (stat (device, &statbuf) == 0)
713 device[5] = 's'; /* Restore original device name. */
716 reply_with_perror ("%s: %s", func, device);