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/* libguestfs - the guestfsd daemon
* Copyright (C) 2009-2012 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 <fcntl.h>
#include <sys/stat.h>
#include "guestfs_protocol.h"
#include "daemon.h"
#include "actions.h"
GUESTFSD_EXT_CMD(str_file, file);
GUESTFSD_EXT_CMD(str_zcat, zcat);
GUESTFSD_EXT_CMD(str_bzcat, bzcat);
int
do_touch (const char *path)
{
int fd;
int r;
struct stat buf;
/* RHBZ#582484: Restrict touch to regular files. It's also OK
* here if the file does not exist, since we will create it.
*
* XXX Coverity flags this as a time-of-check to time-of-use race
* condition, particularly in the libguestfs live case. Not clear
* how to fix this yet, since unconditionally opening the file can
* cause a hang, so you have to somehow check it first before you
* open it.
*/
CHROOT_IN;
r = lstat (path, &buf);
CHROOT_OUT;
if (r == -1) {
if (errno != ENOENT) {
reply_with_perror ("lstat: %s", path);
return -1;
}
} else {
if (! S_ISREG (buf.st_mode)) {
reply_with_error ("%s: touch can only be used on a regular files", path);
return -1;
}
}
CHROOT_IN;
fd = open (path, O_WRONLY|O_CREAT|O_NOCTTY|O_CLOEXEC, 0666);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return -1;
}
r = futimens (fd, NULL);
if (r == -1) {
reply_with_perror ("futimens: %s", path);
close (fd);
return -1;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", path);
return -1;
}
return 0;
}
int
do_rm (const char *path)
{
int r;
CHROOT_IN;
r = unlink (path);
CHROOT_OUT;
if (r == -1) {
reply_with_perror ("%s", path);
return -1;
}
return 0;
}
int
do_rm_f (const char *path)
{
int r;
CHROOT_IN;
r = unlink (path);
CHROOT_OUT;
/* Ignore ENOENT. */
if (r == -1 && errno != ENOENT) {
reply_with_perror ("%s", path);
return -1;
}
return 0;
}
int
do_chmod (int mode, const char *path)
{
int r;
if (mode < 0) {
reply_with_error ("%s: mode is negative", path);
return -1;
}
CHROOT_IN;
r = chmod (path, mode);
CHROOT_OUT;
if (r == -1) {
reply_with_perror ("%s: 0%o", path, mode);
return -1;
}
return 0;
}
int
do_chown (int owner, int group, const char *path)
{
int r;
CHROOT_IN;
r = chown (path, owner, group);
CHROOT_OUT;
if (r == -1) {
reply_with_perror ("%s: %d.%d", path, owner, group);
return -1;
}
return 0;
}
int
do_lchown (int owner, int group, const char *path)
{
int r;
CHROOT_IN;
r = lchown (path, owner, group);
CHROOT_OUT;
if (r == -1) {
reply_with_perror ("%s: %d.%d", path, owner, group);
return -1;
}
return 0;
}
int
do_write_file (const char *path, const char *content, int size)
{
int fd;
/* This call is deprecated, and it has a broken interface. New code
* should use the 'guestfs_write' call instead. Because we used an
* XDR string type, 'content' cannot contain ASCII NUL and 'size'
* must never be longer than the string. We must check this to
* ensure random stuff from XDR or daemon memory isn't written to
* the file (RHBZ#597135).
*/
if (size < 0) {
reply_with_error ("size cannot be negative");
return -1;
}
/* Note content_len must be small because of the limits on protocol
* message size.
*/
int content_len = (int) strlen (content);
if (size == 0)
size = content_len;
else if (size > content_len) {
reply_with_error ("size parameter is larger than string content");
return -1;
}
CHROOT_IN;
fd = open (path, O_WRONLY|O_TRUNC|O_CREAT|O_NOCTTY|O_CLOEXEC, 0666);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return -1;
}
if (xwrite (fd, content, size) == -1) {
reply_with_perror ("write");
close (fd);
return -1;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", path);
return -1;
}
return 0;
}
int
do_internal_write (const char *path, const char *content, size_t size)
{
int fd;
CHROOT_IN;
fd = open (path, O_WRONLY|O_TRUNC|O_CREAT|O_NOCTTY|O_CLOEXEC, 0666);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return -1;
}
if (xwrite (fd, content, size) == -1) {
reply_with_perror ("write");
close (fd);
return -1;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", path);
return -1;
}
return 0;
}
int
do_internal_write_append (const char *path, const char *content, size_t size)
{
int fd;
CHROOT_IN;
fd = open (path, O_WRONLY|O_APPEND|O_CREAT|O_NOCTTY|O_CLOEXEC, 0666);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return -1;
}
if (xwrite (fd, content, size) == -1) {
reply_with_perror ("write");
close (fd);
return -1;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", path);
return -1;
}
return 0;
}
static char *
pread_fd (int fd, int count, int64_t offset, size_t *size_r,
const char *display_path)
{
ssize_t r;
char *buf;
if (count < 0) {
reply_with_error ("count is negative");
close (fd);
return NULL;
}
if (offset < 0) {
reply_with_error ("offset is negative");
close (fd);
return NULL;
}
/* The actual limit on messages is smaller than this. This check
* just limits the amount of memory we'll try and allocate in the
* function. If the message is larger than the real limit, that
* will be caught later when we try to serialize the message.
*/
if (count >= GUESTFS_MESSAGE_MAX) {
reply_with_error ("%s: count is too large for the protocol, use smaller reads", display_path);
close (fd);
return NULL;
}
buf = malloc (count);
if (buf == NULL) {
reply_with_perror ("malloc");
close (fd);
return NULL;
}
r = pread (fd, buf, count, offset);
if (r == -1) {
reply_with_perror ("pread: %s", display_path);
close (fd);
free (buf);
return NULL;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", display_path);
free (buf);
return NULL;
}
/* Mustn't touch *size_r until we are sure that we won't return any
* error (RHBZ#589039).
*/
*size_r = r;
return buf;
}
char *
do_pread (const char *path, int count, int64_t offset, size_t *size_r)
{
int fd;
CHROOT_IN;
fd = open (path, O_RDONLY|O_CLOEXEC);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return NULL;
}
return pread_fd (fd, count, offset, size_r, path);
}
char *
do_pread_device (const char *device, int count, int64_t offset, size_t *size_r)
{
int fd = open (device, O_RDONLY|O_CLOEXEC);
if (fd == -1) {
reply_with_perror ("open: %s", device);
return NULL;
}
return pread_fd (fd, count, offset, size_r, device);
}
static int
pwrite_fd (int fd, const char *content, size_t size, int64_t offset,
const char *display_path)
{
ssize_t r;
r = pwrite (fd, content, size, offset);
if (r == -1) {
reply_with_perror ("pwrite: %s", display_path);
close (fd);
return -1;
}
if (close (fd) == -1) {
reply_with_perror ("close: %s", display_path);
return -1;
}
return r;
}
int
do_pwrite (const char *path, const char *content, size_t size, int64_t offset)
{
int fd;
if (offset < 0) {
reply_with_error ("offset is negative");
return -1;
}
CHROOT_IN;
fd = open (path, O_WRONLY|O_CLOEXEC);
CHROOT_OUT;
if (fd == -1) {
reply_with_perror ("open: %s", path);
return -1;
}
return pwrite_fd (fd, content, size, offset, path);
}
int
do_pwrite_device (const char *device, const char *content, size_t size,
int64_t offset)
{
if (offset < 0) {
reply_with_error ("offset is negative");
return -1;
}
int fd = open (device, O_WRONLY|O_CLOEXEC);
if (fd == -1) {
reply_with_perror ("open: %s", device);
return -1;
}
return pwrite_fd (fd, content, size, offset, device);
}
/* This runs the 'file' command. */
char *
do_file (const char *path)
{
char *buf = NULL;
const char *display_path = path;
int is_dev = STRPREFIX (path, "/dev/");
if (!is_dev) {
buf = sysroot_path (path);
if (!buf) {
reply_with_perror ("malloc");
return NULL;
}
path = buf;
/* For non-dev, check this is a regular file, else just return the
* file type as a string (RHBZ#582484).
*/
struct stat statbuf;
if (lstat (path, &statbuf) == -1) {
reply_with_perror ("lstat: %s", display_path);
free (buf);
return NULL;
}
if (! S_ISREG (statbuf.st_mode)) {
char *ret;
free (buf);
if (S_ISDIR (statbuf.st_mode))
ret = strdup ("directory");
else if (S_ISCHR (statbuf.st_mode))
ret = strdup ("character device");
else if (S_ISBLK (statbuf.st_mode))
ret = strdup ("block device");
else if (S_ISFIFO (statbuf.st_mode))
ret = strdup ("FIFO");
else if (S_ISLNK (statbuf.st_mode))
ret = strdup ("symbolic link");
else if (S_ISSOCK (statbuf.st_mode))
ret = strdup ("socket");
else
ret = strdup ("unknown, not regular file");
if (ret == NULL)
reply_with_perror ("strdup");
return ret;
}
}
/* Which flags to use? For /dev paths, follow links because
* /dev/VG/LV is a symbolic link.
*/
const char *flags = is_dev ? "-zbsL" : "-zb";
char *out, *err;
int r = command (&out, &err, str_file, flags, path, NULL);
free (buf);
if (r == -1) {
free (out);
reply_with_error ("%s: %s", display_path, err);
free (err);
return NULL;
}
free (err);
/* We need to remove the trailing \n from output of file(1). */
size_t len = strlen (out);
if (len > 0 && out[len-1] == '\n')
out[len-1] = '\0';
return out; /* caller frees */
}
/* zcat | file */
char *
do_zfile (const char *method, const char *path)
{
size_t len;
const char *zcat;
char *cmd;
FILE *fp;
char line[256];
if (STREQ (method, "gzip") || STREQ (method, "compress"))
zcat = str_zcat;
else if (STREQ (method, "bzip2"))
zcat = str_bzcat;
else {
reply_with_error ("unknown method");
return NULL;
}
if (asprintf_nowarn (&cmd, "%s %R | file -bsL -", zcat, path) == -1) {
reply_with_perror ("asprintf");
return NULL;
}
if (verbose)
fprintf (stderr, "%s\n", cmd);
fp = popen (cmd, "r");
if (fp == NULL) {
reply_with_perror ("%s", cmd);
free (cmd);
return NULL;
}
free (cmd);
if (fgets (line, sizeof line, fp) == NULL) {
reply_with_perror ("fgets");
fclose (fp);
return NULL;
}
if (fclose (fp) == -1) {
reply_with_perror ("fclose");
return NULL;
}
len = strlen (line);
if (len > 0 && line[len-1] == '\n')
line[len-1] = '\0';
return strdup (line);
}
int64_t
do_filesize (const char *path)
{
int r;
struct stat buf;
CHROOT_IN;
r = stat (path, &buf); /* follow symlinks */
CHROOT_OUT;
if (r == -1) {
reply_with_perror ("%s", path);
return -1;
}
return buf.st_size;
}
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