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/* libguestfs - the guestfsd daemon
* Copyright (C) 2009 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 <unistd.h>
#include <limits.h>
#include "daemon.h"
#include "actions.h"
static char *
get_blkid_tag (const char *device, const char *tag)
{
char *out, *err;
int r;
r = commandr (&out, &err,
"blkid",
/* Adding -c option kills all caching, even on RHEL 5. */
"-c", "/dev/null",
"-o", "value", "-s", tag, device, NULL);
if (r != 0 && r != 2) {
if (r >= 0)
reply_with_error ("%s: %s (blkid returned %d)", device, err, r);
else
reply_with_error ("%s: %s", device, err);
free (out);
free (err);
return NULL;
}
free (err);
if (r == 2) { /* means UUID etc not found */
free (out);
out = strdup ("");
if (out == NULL)
reply_with_perror ("strdup");
return out;
}
/* Trim trailing \n if present. */
size_t len = strlen (out);
if (len > 0 && out[len-1] == '\n')
out[len-1] = '\0';
return out; /* caller frees */
}
char *
do_vfs_type (const char *device)
{
return get_blkid_tag (device, "TYPE");
}
char *
do_vfs_label (const char *device)
{
return get_blkid_tag (device, "LABEL");
}
char *
do_vfs_uuid (const char *device)
{
return get_blkid_tag (device, "UUID");
}
/* RHEL5 blkid doesn't have the -p (low-level probing) option and the
* -i(I/O limits) option so we must test for these options the first
* time the function is called.
*
* Debian 6 has -p but not -i.
*/
static int
test_blkid_p_i_opt (void)
{
int r;
char *err;
r = commandr (NULL, &err, "blkid", "-p", "/dev/null", NULL);
if (r == -1) {
/* This means we couldn't run the blkid command at all. */
command_failed:
reply_with_error ("could not run 'blkid' command: %s", err);
free (err);
return -1;
}
if (strstr (err, "invalid option --")) {
free (err);
return 0;
}
free (err);
r = commandr (NULL, &err, "blkid", "-i", NULL);
if (r == -1)
goto command_failed;
if (strstr (err, "invalid option --")) {
free (err);
return 0;
}
free (err);
/* We have both options. */
return 1;
}
static char **
blkid_with_p_i_opt (const char *device)
{
size_t i;
int r;
char *out = NULL, *err = NULL;
char **lines = NULL;
DECLARE_STRINGSBUF (ret);
r = command (&out, &err, "blkid", "-c", "/dev/null",
"-p", "-i", "-o", "export", device, NULL);
if (r == -1) {
reply_with_error ("%s", err);
goto error;
}
/* Split the command output into lines */
lines = split_lines (out);
if (lines == NULL)
goto error;
/* Parse the output of blkid -p -i -o export:
* UUID=b6d83437-c6b4-4bf0-8381-ef3fc3578590
* VERSION=1.0
* TYPE=ext2
* USAGE=filesystem
* MINIMUM_IO_SIZE=512
* PHYSICAL_SECTOR_SIZE=512
* LOGICAL_SECTOR_SIZE=512
* PART_ENTRY_SCHEME=dos
* PART_ENTRY_TYPE=0x83
* PART_ENTRY_NUMBER=6
* PART_ENTRY_OFFSET=642875153
* PART_ENTRY_SIZE=104857600
* PART_ENTRY_DISK=8:0
*/
for (i = 0; lines[i] != NULL; ++i) {
char *line = lines[i];
/* Skip blank lines (shouldn't happen) */
if (line[0] == '\0') continue;
/* Split the line in 2 at the equals sign */
char *eq = strchr (line, '=');
if (eq) {
*eq = '\0'; eq++;
/* Add the key/value pair to the output */
if (add_string (&ret, line) == -1 ||
add_string (&ret, eq) == -1) goto error;
} else {
fprintf (stderr, "blkid: unexpected blkid output ignored: %s", line);
}
}
if (end_stringsbuf (&ret) == -1) goto error;
free (out);
free (err);
free_strings (lines);
return ret.argv;
error:
free (out);
free (err);
if (lines)
free_strings (lines);
if (ret.argv)
free_strings (ret.argv);
return NULL;
}
static char **
blkid_without_p_i_opt(const char *device)
{
char *s;
DECLARE_STRINGSBUF (ret);
if (add_string (&ret, "TYPE") == -1) goto error;
s = get_blkid_tag (device, "TYPE");
if (s == NULL) goto error;
if (add_string (&ret, s) == -1)
goto error;
if (add_string (&ret, "LABEL") == -1) goto error;
s = get_blkid_tag (device, "LABEL");
if (s == NULL) goto error;
if (add_string (&ret, s) == -1)
goto error;
if (add_string (&ret, "UUID") == -1) goto error;
s = get_blkid_tag (device, "UUID");
if (s == NULL) goto error;
if (add_string (&ret, s) == -1)
goto error;
if (end_stringsbuf (&ret) == -1) goto error;
return ret.argv;
error:
if (ret.argv)
free_strings (ret.argv);
return NULL;
}
char **
do_blkid (const char *device)
{
static int blkid_has_p_i_opt = -1;
if (blkid_has_p_i_opt == -1) {
blkid_has_p_i_opt = test_blkid_p_i_opt ();
if (blkid_has_p_i_opt == -1)
return NULL;
}
if (blkid_has_p_i_opt)
return blkid_with_p_i_opt (device);
else
return blkid_without_p_i_opt (device);
}
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