Files
libguestfs/daemon/available.c
Richard W.M. Jones d5a8f82887 Use 'const' for stack integers where possible.
May improve optimization possibilities in a few cases.
2016-07-26 10:43:45 +01:00

145 lines
3.4 KiB
C

/* 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 "c-ctype.h"
#include "ignore-value.h"
#include "guestfs_protocol.h"
#include "daemon.h"
#include "actions.h"
#include "optgroups.h"
GUESTFSD_EXT_CMD(str_grep, grep);
GUESTFSD_EXT_CMD(str_modprobe, modprobe);
int
do_internal_feature_available (const char *group)
{
size_t i;
for (i = 0; optgroups[i].group != NULL; ++i) {
if (STREQ (group, optgroups[i].group)) {
const int av = optgroups[i].available ();
return av ? 0 : 1;
}
}
/* Unknown group */
return 2;
}
char **
do_available_all_groups (void)
{
size_t i;
CLEANUP_FREE_STRINGSBUF DECLARE_STRINGSBUF (groups);
for (i = 0; optgroups[i].group != NULL; ++i) {
if (add_string (&groups, optgroups[i].group) == -1)
return NULL;
}
if (end_stringsbuf (&groups) == -1)
return NULL;
return take_stringsbuf (&groups); /* caller frees */
}
/* Search for filesystem in /proc/filesystems, ignoring "nodev". */
static int
test_proc_filesystems (const char *filesystem)
{
CLEANUP_FREE char *regex = NULL;
CLEANUP_FREE char *err = NULL;
int r;
if (asprintf (&regex, "^[[:space:]]*%s$", filesystem) == -1) {
perror ("asprintf");
return -1;
}
r = commandr (NULL, &err, str_grep, regex, "/proc/filesystems", NULL);
if (r == -1 || r >= 2) {
fprintf (stderr, "grep /proc/filesystems: %s", err);
return -1;
}
return r == 0;
}
/* Do modprobe, ignore any errors. */
static void
modprobe (const char *module)
{
ignore_value (command (NULL, NULL, str_modprobe, module, NULL));
}
/* Internal function for testing if a filesystem is available. Note
* this must not call reply_with_error functions.
*/
int
filesystem_available (const char *filesystem)
{
int r;
r = test_proc_filesystems (filesystem);
if (r == -1 || r > 0)
return r;
/* Not found: try to modprobe the module, then test again. */
if (optgroup_linuxmodules_available ()) {
modprobe (filesystem);
r = test_proc_filesystems (filesystem);
if (r == -1)
return -1;
}
return r;
}
int
do_filesystem_available (const char *filesystem)
{
size_t i;
const size_t len = strlen (filesystem);
int r;
for (i = 0; i < len; ++i) {
if (!c_isalnum (filesystem[i]) && filesystem[i] != '_') {
reply_with_error ("filesystem name contains non-alphanumeric characters");
return -1;
}
}
r = filesystem_available (filesystem);
if (r == -1) {
reply_with_error ("error testing for filesystem availability; "
"enable verbose mode and look at preceding output");
return -1;
}
return r;
}