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mirror of git://git.gnupg.org/gnupg.git synced 2024-12-23 10:29:58 +01:00
gnupg/g13/backend.c
Werner Koch 18e5dd7b03
Replace all calls to stat by gnupg_stat.
* common/sysutils.c (gnupg_stat): New.
* common/sysutils.h: Include sys/stat.h.
--

Yet another wrapper for Unicode support on Windows.

GnuPG-bug-id: 5098
Signed-off-by: Werner Koch <wk@gnupg.org>
2020-10-20 16:38:06 +02:00

297 lines
7.0 KiB
C

/* backend.c - Dispatcher to the various backends.
* Copyright (C) 2009 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG 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 3 of the License, or
* (at your option) any later version.
*
* GnuPG 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, see <https://www.gnu.org/licenses/>.
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sys/stat.h>
#include "g13.h"
#include "../common/i18n.h"
#include "../common/sysutils.h"
#include "keyblob.h"
#include "backend.h"
#include "be-encfs.h"
#include "be-truecrypt.h"
#include "be-dmcrypt.h"
#include "call-syshelp.h"
#define no_such_backend(a) _no_such_backend ((a), __func__)
static gpg_error_t
_no_such_backend (int conttype, const char *func)
{
log_error ("invalid backend %d given in %s - this is most likely a bug\n",
conttype, func);
return gpg_error (GPG_ERR_INTERNAL);
}
/* Parse NAME and return the corresponding content type. If the name
is not known, a error message is printed and zero returned. If
NAME is NULL the supported backend types are listed and 0 is
returned. */
int
be_parse_conttype_name (const char *name)
{
static struct { const char *name; int conttype; } names[] = {
{ "encfs", CONTTYPE_ENCFS },
{ "dm-crypt", CONTTYPE_DM_CRYPT }
};
int i;
if (!name)
{
log_info ("Known backend types:\n");
for (i=0; i < DIM (names); i++)
log_info (" %s\n", names[i].name);
return 0;
}
for (i=0; i < DIM (names); i++)
{
if (!strcmp (names[i].name, name))
return names[i].conttype;
}
log_error ("invalid backend type '%s' given\n", name);
return 0;
}
/* Return true if CONTTYPE is supported by us. */
int
be_is_supported_conttype (int conttype)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
case CONTTYPE_DM_CRYPT:
return 1;
default:
return 0;
}
}
/* Create a lock file for the container FNAME and store the lock at
* R_LOCK and return 0. On error return an error code and store NULL
* at R_LOCK. */
gpg_error_t
be_take_lock_for_create (ctrl_t ctrl, const char *fname, dotlock_t *r_lock)
{
gpg_error_t err;
dotlock_t lock = NULL;
struct stat sb;
*r_lock = NULL;
/* A DM-crypt container requires special treatment by using the
syshelper functions. */
if (ctrl->conttype == CONTTYPE_DM_CRYPT)
{
/* */
err = call_syshelp_set_device (ctrl, fname);
goto leave;
}
/* A quick check to see that no container with that name already
exists. */
if (!gnupg_access (fname, F_OK))
{
err = gpg_error (GPG_ERR_EEXIST);
goto leave;
}
/* Take a lock and proceed with the creation. If there is a lock we
immediately return an error because for creation it does not make
sense to wait. */
lock = dotlock_create (fname, 0);
if (!lock)
{
err = gpg_error_from_syserror ();
goto leave;
}
if (dotlock_take (lock, 0))
{
err = gpg_error_from_syserror ();
goto leave;
}
/* Check again that the file does not exist. */
err = gnupg_stat (fname, &sb)? 0 : gpg_error (GPG_ERR_EEXIST);
leave:
if (!err)
{
*r_lock = lock;
lock = NULL;
}
dotlock_destroy (lock);
return err;
}
/* If the backend requires a separate file or directory for the
container, return its name by computing it from FNAME which gives
the g13 filename. The new file name is allocated and stored at
R_NAME, if this is expected to be a directory true is stored at
R_ISDIR. If no detached name is expected or an error occurs NULL
is stored at R_NAME. The function returns 0 on success or an error
code. */
gpg_error_t
be_get_detached_name (int conttype, const char *fname,
char **r_name, int *r_isdir)
{
*r_name = NULL;
*r_isdir = 0;
switch (conttype)
{
case CONTTYPE_ENCFS:
return be_encfs_get_detached_name (fname, r_name, r_isdir);
case CONTTYPE_DM_CRYPT:
return 0;
default:
return no_such_backend (conttype);
}
}
gpg_error_t
be_create_new_keys (int conttype, membuf_t *mb)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
return be_encfs_create_new_keys (mb);
case CONTTYPE_TRUECRYPT:
return be_truecrypt_create_new_keys (mb);
case CONTTYPE_DM_CRYPT:
return 0;
default:
return no_such_backend (conttype);
}
}
/* Dispatcher to the backend's create function. */
gpg_error_t
be_create_container (ctrl_t ctrl, int conttype,
const char *fname, int fd, tupledesc_t tuples,
unsigned int *r_id)
{
(void)fd; /* Not yet used. */
switch (conttype)
{
case CONTTYPE_ENCFS:
return be_encfs_create_container (ctrl, fname, tuples, r_id);
case CONTTYPE_DM_CRYPT:
return be_dmcrypt_create_container (ctrl);
default:
return no_such_backend (conttype);
}
}
/* Dispatcher to the backend's mount function. */
gpg_error_t
be_mount_container (ctrl_t ctrl, int conttype,
const char *fname, const char *mountpoint,
tupledesc_t tuples, unsigned int *r_id)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
return be_encfs_mount_container (ctrl, fname, mountpoint, tuples, r_id);
case CONTTYPE_DM_CRYPT:
return be_dmcrypt_mount_container (ctrl, fname, mountpoint, tuples);
default:
return no_such_backend (conttype);
}
}
/* Dispatcher to the backend's umount function. */
gpg_error_t
be_umount_container (ctrl_t ctrl, int conttype, const char *fname)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
return gpg_error (GPG_ERR_NOT_SUPPORTED);
case CONTTYPE_DM_CRYPT:
return be_dmcrypt_umount_container (ctrl, fname);
default:
return no_such_backend (conttype);
}
}
/* Dispatcher to the backend's suspend function. */
gpg_error_t
be_suspend_container (ctrl_t ctrl, int conttype, const char *fname)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
return gpg_error (GPG_ERR_NOT_SUPPORTED);
case CONTTYPE_DM_CRYPT:
return be_dmcrypt_suspend_container (ctrl, fname);
default:
return no_such_backend (conttype);
}
}
/* Dispatcher to the backend's resume function. */
gpg_error_t
be_resume_container (ctrl_t ctrl, int conttype, const char *fname,
tupledesc_t tuples)
{
switch (conttype)
{
case CONTTYPE_ENCFS:
return gpg_error (GPG_ERR_NOT_SUPPORTED);
case CONTTYPE_DM_CRYPT:
return be_dmcrypt_resume_container (ctrl, fname, tuples);
default:
return no_such_backend (conttype);
}
}