1
0
mirror of https://github.com/samba-team/samba.git synced 2024-12-23 17:34:34 +03:00
samba-mirror/libcli/smb/reparse_symlink.c
Volker Lendecke e7516fa988 libsmb: Factor out reparse_buffer_marshall from symlink_reparse_buffer_marshall()
Make it easier to play with reparse points

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
2022-11-22 18:27:33 +00:00

267 lines
6.0 KiB
C

/*
* Unix SMB/CIFS implementation.
*
* Implementation of
* http://msdn.microsoft.com/en-us/library/cc232006%28v=PROT.13%29.aspx
*
* Copyright (C) Volker Lendecke 2011
*
* 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 3 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, see <http://www.gnu.org/licenses/>.
*/
#include "replace.h"
#include "reparse_symlink.h"
#include "lib/util/charset/charset.h"
#include "lib/util/byteorder.h"
#include "libcli/smb/smb_constants.h"
#include "libcli/smb/smb_util.h"
#include "lib/util/debug.h"
ssize_t reparse_buffer_marshall(
uint32_t reparse_tag,
uint16_t reserved,
const struct iovec *iov,
int iovlen,
uint8_t *buf,
size_t buflen)
{
ssize_t reparse_data_length = iov_buflen(iov, iovlen);
size_t needed;
if (reparse_data_length == -1) {
return -1;
}
if (reparse_data_length > UINT16_MAX) {
return -1;
}
needed = reparse_data_length + 8;
if (needed < reparse_data_length) {
return -1;
}
if (buflen >= needed) {
PUSH_LE_U32(buf, 0, reparse_tag);
PUSH_LE_U16(buf, 4, reparse_data_length);
PUSH_LE_U16(buf, 6, reserved);
iov_buf(iov, iovlen, buf+8, buflen-8);
}
return needed;
}
bool symlink_reparse_buffer_marshall(
const char *substitute,
const char *printname,
uint16_t unparsed_path_length,
uint32_t flags,
TALLOC_CTX *mem_ctx,
uint8_t **pdst,
size_t *pdstlen)
{
uint8_t sbuf[12];
struct iovec iov[3];
uint8_t *dst = NULL;
ssize_t dst_len;
uint8_t *subst_utf16 = NULL;
uint8_t *print_utf16 = NULL;
size_t subst_len = 0;
size_t print_len = 0;
bool ret = false;
bool ok;
if (substitute == NULL) {
return false;
}
if (printname == NULL) {
printname = substitute;
}
iov[0] = (struct iovec) { .iov_base = sbuf, .iov_len = sizeof(sbuf), };
ok = convert_string_talloc(
mem_ctx,
CH_UNIX,
CH_UTF16,
substitute,
strlen(substitute),
&subst_utf16,
&subst_len);
if (!ok) {
goto fail;
}
if (subst_len > UINT16_MAX) {
goto fail;
}
iov[1] = (struct iovec) {
.iov_base = subst_utf16, .iov_len = subst_len,
};
ok = convert_string_talloc(
mem_ctx,
CH_UNIX,
CH_UTF16,
printname,
strlen(printname),
&print_utf16,
&print_len);
if (!ok) {
goto fail;
}
if (print_len > UINT16_MAX) {
goto fail;
}
iov[2] = (struct iovec) {
.iov_base = print_utf16, .iov_len = print_len,
};
PUSH_LE_U16(sbuf, 0, 0); /* SubstituteNameOffset */
PUSH_LE_U16(sbuf, 2, subst_len); /* SubstituteNameLength */
PUSH_LE_U16(sbuf, 4, subst_len); /* PrintNameOffset */
PUSH_LE_U16(sbuf, 6, print_len); /* PrintNameLength */
PUSH_LE_U32(sbuf, 8, flags); /* Flags */
dst_len = reparse_buffer_marshall(
IO_REPARSE_TAG_SYMLINK,
unparsed_path_length,
iov,
ARRAY_SIZE(iov),
NULL,
0);
if (dst_len == -1) {
goto fail;
}
dst = talloc_array(mem_ctx, uint8_t, dst_len);
if (dst == NULL) {
goto fail;
}
reparse_buffer_marshall(
IO_REPARSE_TAG_SYMLINK,
unparsed_path_length,
iov,
ARRAY_SIZE(iov),
dst,
dst_len);
*pdst = dst;
*pdstlen = dst_len;
ret = true;
fail:
TALLOC_FREE(subst_utf16);
TALLOC_FREE(print_utf16);
return ret;
}
struct symlink_reparse_struct *symlink_reparse_buffer_parse(
TALLOC_CTX *mem_ctx, const uint8_t *src, size_t srclen)
{
struct symlink_reparse_struct *result = NULL;
uint16_t reparse_data_length;
uint16_t substitute_name_offset, substitute_name_length;
uint16_t print_name_offset, print_name_length;
bool ok;
if (srclen < 20) {
DBG_DEBUG("srclen = %zu, expected >= 20\n", srclen);
goto fail;
}
if (IVAL(src, 0) != IO_REPARSE_TAG_SYMLINK) {
DBG_DEBUG("Got ReparseTag %8.8x, expected %8.8x\n",
IVAL(src, 0),
IO_REPARSE_TAG_SYMLINK);
goto fail;
}
reparse_data_length = SVAL(src, 4);
substitute_name_offset = SVAL(src, 8);
substitute_name_length = SVAL(src, 10);
print_name_offset = SVAL(src, 12);
print_name_length = SVAL(src, 14);
if (reparse_data_length < 12) {
DBG_DEBUG("reparse_data_length = %"PRIu16", expected >= 12\n",
reparse_data_length);
goto fail;
}
if (smb_buffer_oob(srclen - 8, reparse_data_length, 0)) {
DBG_DEBUG("reparse_data_length (%"PRIu16") too large for "
"src_len (%zu)\n",
reparse_data_length,
srclen);
goto fail;
}
if (smb_buffer_oob(reparse_data_length - 12, substitute_name_offset,
substitute_name_length)) {
DBG_DEBUG("substitute_name (%"PRIu16"/%"PRIu16") does not fit "
"in reparse_data_length (%"PRIu16")\n",
substitute_name_offset,
substitute_name_length,
reparse_data_length - 12);
goto fail;
}
if (smb_buffer_oob(reparse_data_length - 12, print_name_offset,
print_name_length)) {
DBG_DEBUG("print_name (%"PRIu16"/%"PRIu16") does not fit in "
"reparse_data_length (%"PRIu16")\n",
print_name_offset,
print_name_length,
reparse_data_length - 12);
goto fail;
}
result = talloc_zero(mem_ctx, struct symlink_reparse_struct);
if (result == NULL) {
DBG_DEBUG("talloc failed\n");
goto fail;
}
ok = convert_string_talloc(
result,
CH_UTF16,
CH_UNIX,
src + 20 + substitute_name_offset,
substitute_name_length,
&result->substitute_name,
NULL);
if (!ok) {
DBG_DEBUG("convert_string_talloc for substitute_name "
"failed\n");
goto fail;
}
ok = convert_string_talloc(
result,
CH_UTF16,
CH_UNIX,
src + 20 + print_name_offset,
print_name_length,
&result->print_name,
NULL);
if (!ok) {
DBG_DEBUG("convert_string_talloc for print_name failed\n");
goto fail;
}
result->unparsed_path_length = SVAL(src, 6);
result->flags = IVAL(src, 16);
return result;
fail:
TALLOC_FREE(result);
return NULL;
}