/*
   Unix SMB/CIFS implementation.
   client file operations
   Copyright (C) Andrew Tridgell 1994-1998
   Copyright (C) Jeremy Allison 2001-2002
   Copyright (C) James Myers 2003

   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 "includes.h"
#include "libcli/smb/smb_common.h"
#include "system/filesys.h"
#include "lib/param/loadparm.h"

const char *smb_protocol_types_string(enum protocol_types protocol)
{
	switch (protocol) {
	case PROTOCOL_DEFAULT:
		return "DEFAULT";
	case PROTOCOL_NONE:
		return "NONE";
	case PROTOCOL_CORE:
		return "CORE";
	case PROTOCOL_COREPLUS:
		return "COREPLUS";
	case PROTOCOL_LANMAN1:
		return "LANMAN1";
	case PROTOCOL_LANMAN2:
		return "LANMAN2";
	case PROTOCOL_NT1:
		return "NT1";
	case PROTOCOL_SMB2_02:
		return "SMB2_02";
	case PROTOCOL_SMB2_10:
		return "SMB2_10";
	case PROTOCOL_SMB2_22:
		return "SMB2_22";
	case PROTOCOL_SMB2_24:
		return "SMB2_24";
	case PROTOCOL_SMB3_00:
		return "SMB3_00";
	case PROTOCOL_SMB3_02:
		return "SMB3_02";
	case PROTOCOL_SMB3_10:
		return "SMB3_10";
	case PROTOCOL_SMB3_11:
		return "SMB3_11";
	}

	return "Invalid protocol_types value";
}

/**
 Return a string representing a CIFS attribute for a file.
**/
char *attrib_string(TALLOC_CTX *mem_ctx, uint32_t attrib)
{
	size_t i, len;
	const struct {
		char c;
		uint16_t attr;
	} attr_strs[] = {
		{'V', FILE_ATTRIBUTE_VOLUME},
		{'D', FILE_ATTRIBUTE_DIRECTORY},
		{'A', FILE_ATTRIBUTE_ARCHIVE},
		{'H', FILE_ATTRIBUTE_HIDDEN},
		{'S', FILE_ATTRIBUTE_SYSTEM},
		{'N', FILE_ATTRIBUTE_NORMAL},
		{'R', FILE_ATTRIBUTE_READONLY},
		{'d', FILE_ATTRIBUTE_DEVICE},
		{'t', FILE_ATTRIBUTE_TEMPORARY},
		{'s', FILE_ATTRIBUTE_SPARSE},
		{'r', FILE_ATTRIBUTE_REPARSE_POINT},
		{'c', FILE_ATTRIBUTE_COMPRESSED},
		{'o', FILE_ATTRIBUTE_OFFLINE},
		{'n', FILE_ATTRIBUTE_NONINDEXED},
		{'e', FILE_ATTRIBUTE_ENCRYPTED}
	};
	char *ret;

	ret = talloc_array(mem_ctx, char, ARRAY_SIZE(attr_strs)+1);
	if (!ret) {
		return NULL;
	}

	for (len=i=0; i<ARRAY_SIZE(attr_strs); i++) {
		if (attrib & attr_strs[i].attr) {
			ret[len++] = attr_strs[i].c;
		}
	}

	ret[len] = 0;

	talloc_set_name_const(ret, ret);

	return ret;
}

/****************************************************************************
 Map standard UNIX permissions onto wire representations.
****************************************************************************/

uint32_t unix_perms_to_wire(mode_t perms)
{
        unsigned int ret = 0;

        ret |= ((perms & S_IXOTH) ?  UNIX_X_OTH : 0);
        ret |= ((perms & S_IWOTH) ?  UNIX_W_OTH : 0);
        ret |= ((perms & S_IROTH) ?  UNIX_R_OTH : 0);
        ret |= ((perms & S_IXGRP) ?  UNIX_X_GRP : 0);
        ret |= ((perms & S_IWGRP) ?  UNIX_W_GRP : 0);
        ret |= ((perms & S_IRGRP) ?  UNIX_R_GRP : 0);
        ret |= ((perms & S_IXUSR) ?  UNIX_X_USR : 0);
        ret |= ((perms & S_IWUSR) ?  UNIX_W_USR : 0);
        ret |= ((perms & S_IRUSR) ?  UNIX_R_USR : 0);
#ifdef S_ISVTX
        ret |= ((perms & S_ISVTX) ?  UNIX_STICKY : 0);
#endif
#ifdef S_ISGID
        ret |= ((perms & S_ISGID) ?  UNIX_SET_GID : 0);
#endif
#ifdef S_ISUID
        ret |= ((perms & S_ISUID) ?  UNIX_SET_UID : 0);
#endif
        return ret;
}

/****************************************************************************
 Map wire permissions to standard UNIX.
****************************************************************************/

mode_t wire_perms_to_unix(uint32_t perms)
{
        mode_t ret = (mode_t)0;

        ret |= ((perms & UNIX_X_OTH) ? S_IXOTH : 0);
        ret |= ((perms & UNIX_W_OTH) ? S_IWOTH : 0);
        ret |= ((perms & UNIX_R_OTH) ? S_IROTH : 0);
        ret |= ((perms & UNIX_X_GRP) ? S_IXGRP : 0);
        ret |= ((perms & UNIX_W_GRP) ? S_IWGRP : 0);
        ret |= ((perms & UNIX_R_GRP) ? S_IRGRP : 0);
        ret |= ((perms & UNIX_X_USR) ? S_IXUSR : 0);
        ret |= ((perms & UNIX_W_USR) ? S_IWUSR : 0);
        ret |= ((perms & UNIX_R_USR) ? S_IRUSR : 0);
#ifdef S_ISVTX
        ret |= ((perms & UNIX_STICKY) ? S_ISVTX : 0);
#endif
#ifdef S_ISGID
        ret |= ((perms & UNIX_SET_GID) ? S_ISGID : 0);
#endif
#ifdef S_ISUID
        ret |= ((perms & UNIX_SET_UID) ? S_ISUID : 0);
#endif
        return ret;
}

/****************************************************************************
 Return the file type from the wire filetype for UNIX extensions.
****************************************************************************/

mode_t unix_filetype_from_wire(uint32_t wire_type)
{
	switch (wire_type) {
		case UNIX_TYPE_FILE:
			return S_IFREG;
		case UNIX_TYPE_DIR:
			return S_IFDIR;
#ifdef S_IFLNK
		case UNIX_TYPE_SYMLINK:
			return S_IFLNK;
#endif
#ifdef S_IFCHR
		case UNIX_TYPE_CHARDEV:
			return S_IFCHR;
#endif
#ifdef S_IFBLK
		case UNIX_TYPE_BLKDEV:
			return S_IFBLK;
#endif
#ifdef S_IFIFO
		case UNIX_TYPE_FIFO:
			return S_IFIFO;
#endif
#ifdef S_IFSOCK
		case UNIX_TYPE_SOCKET:
			return S_IFSOCK;
#endif
		default:
			return (mode_t)0;
	}
}

bool smb_buffer_oob(uint32_t bufsize, uint32_t offset, uint32_t length)
{
	if ((offset + length < offset) || (offset + length < length)) {
		/* wrap */
		return true;
	}
	if ((offset > bufsize) || (offset + length > bufsize)) {
		/* overflow */
		return true;
	}
	return false;
}

/***********************************************************
 Common function for pushing stings, used by smb_bytes_push_str()
 and trans_bytes_push_str(). Only difference is the align_odd
 parameter setting.
***********************************************************/

static uint8_t *internal_bytes_push_str(uint8_t *buf, bool ucs2,
					const char *str, size_t str_len,
					bool align_odd,
					size_t *pconverted_size)
{
	TALLOC_CTX *frame = talloc_stackframe();
	size_t buflen;
	char *converted;
	size_t converted_size;

	/*
	 * This check prevents us from
	 * (re)alloc buf on a NULL TALLOC_CTX.
	 */
	if (buf == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}

	buflen = talloc_get_size(buf);

	if (ucs2 &&
	    ((align_odd && (buflen % 2 == 0)) ||
	     (!align_odd && (buflen % 2 == 1)))) {
		/*
		 * We're pushing into an SMB buffer, align odd
		 */
		buf = talloc_realloc(NULL, buf, uint8_t, buflen + 1);
		if (buf == NULL) {
			TALLOC_FREE(frame);
			return NULL;
		}
		buf[buflen] = '\0';
		buflen += 1;
	}

	if (!convert_string_talloc(frame, CH_UNIX,
				   ucs2 ? CH_UTF16LE : CH_DOS,
				   str, str_len, &converted,
				   &converted_size)) {
		TALLOC_FREE(frame);
		return NULL;
	}

	buf = talloc_realloc(NULL, buf, uint8_t,
			     buflen + converted_size);
	if (buf == NULL) {
		TALLOC_FREE(frame);
		return NULL;
	}

	memcpy(buf + buflen, converted, converted_size);

	TALLOC_FREE(converted);

	if (pconverted_size) {
		*pconverted_size = converted_size;
	}

	TALLOC_FREE(frame);
	return buf;
}

/***********************************************************
 Push a string into an SMB buffer, with odd byte alignment
 if it's a UCS2 string.
***********************************************************/

uint8_t *smb_bytes_push_str(uint8_t *buf, bool ucs2,
			    const char *str, size_t str_len,
			    size_t *pconverted_size)
{
	return internal_bytes_push_str(buf, ucs2, str, str_len,
				       true, pconverted_size);
}

uint8_t *smb_bytes_push_bytes(uint8_t *buf, uint8_t prefix,
			      const uint8_t *bytes, size_t num_bytes)
{
	size_t buflen;

	/*
	 * This check prevents us from
	 * (re)alloc buf on a NULL TALLOC_CTX.
	 */
	if (buf == NULL) {
		return NULL;
	}
	buflen = talloc_get_size(buf);

	buf = talloc_realloc(NULL, buf, uint8_t,
			     buflen + 1 + num_bytes);
	if (buf == NULL) {
		return NULL;
	}
	buf[buflen] = prefix;
	memcpy(&buf[buflen+1], bytes, num_bytes);
	return buf;
}

/***********************************************************
 Same as smb_bytes_push_str(), but without the odd byte
 align for ucs2 (we're pushing into a param or data block).
 static for now, although this will probably change when
 other modules use async trans calls.
***********************************************************/

uint8_t *trans2_bytes_push_str(uint8_t *buf, bool ucs2,
			       const char *str, size_t str_len,
			       size_t *pconverted_size)
{
	return internal_bytes_push_str(buf, ucs2, str, str_len,
				       false, pconverted_size);
}

uint8_t *trans2_bytes_push_bytes(uint8_t *buf,
				 const uint8_t *bytes, size_t num_bytes)
{
	size_t buflen;

	if (buf == NULL) {
		return NULL;
	}
	buflen = talloc_get_size(buf);

	buf = talloc_realloc(NULL, buf, uint8_t,
			     buflen + num_bytes);
	if (buf == NULL) {
		return NULL;
	}
	memcpy(&buf[buflen], bytes, num_bytes);
	return buf;
}

static NTSTATUS internal_bytes_pull_str(TALLOC_CTX *mem_ctx, char **_str,
					bool ucs2, bool align_odd,
					const uint8_t *buf, size_t buf_len,
					const uint8_t *position,
					size_t *p_consumed)
{
	size_t pad = 0;
	size_t offset;
	char *str = NULL;
	size_t str_len = 0;
	bool ok;

	*_str = NULL;
	if (p_consumed != NULL) {
		*p_consumed = 0;
	}

	if (position < buf) {
		return NT_STATUS_INTERNAL_ERROR;
	}

	offset = PTR_DIFF(position, buf);
	if (offset > buf_len) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}

	if (ucs2 &&
	    ((align_odd && (offset % 2 == 0)) ||
	     (!align_odd && (offset % 2 == 1)))) {
		pad += 1;
		offset += 1;
	}

	if (offset > buf_len) {
		return NT_STATUS_BUFFER_TOO_SMALL;
	}

	buf_len -= offset;
	buf += offset;

	if (ucs2) {
		buf_len = utf16_len_n(buf, buf_len);
	} else {
		size_t tmp = strnlen((const char *)buf, buf_len);
		if (tmp < buf_len) {
			tmp += 1;
		}
		buf_len = tmp;
	}

	ok = convert_string_talloc(mem_ctx,
				   ucs2 ? CH_UTF16LE : CH_DOS,
				   CH_UNIX,
				   buf, buf_len,
				   &str, &str_len);
	if (!ok) {
		return map_nt_error_from_unix_common(errno);
	}

	if (p_consumed != NULL) {
		*p_consumed = buf_len + pad;
	}
	*_str = str;
	return NT_STATUS_OK;
}

NTSTATUS smb_bytes_pull_str(TALLOC_CTX *mem_ctx, char **_str, bool ucs2,
			    const uint8_t *buf, size_t buf_len,
			    const uint8_t *position,
			    size_t *_consumed)
{
	return internal_bytes_pull_str(mem_ctx, _str, ucs2, true,
				       buf, buf_len, position, _consumed);
}

/**
 * @brief Translate SMB signing settings as string to an enum.
 *
 * @param[in]  str  The string to translate.
 *
 * @return A corresponding enum @smb_signing_setting tranlated from the string.
 */
enum smb_signing_setting smb_signing_setting_translate(const char *str)
{
	enum smb_signing_setting signing_state = SMB_SIGNING_REQUIRED;
	int32_t val = lpcfg_parse_enum_vals("client signing", str);

	if (val != INT32_MIN) {
		signing_state = val;
	}

	return signing_state;
}

/**
 * @brief Translate SMB encryption settings as string to an enum.
 *
 * @param[in]  str  The string to translate.
 *
 * @return A corresponding enum @smb_encryption_setting tranlated from the
 *         string.
 */
enum smb_encryption_setting smb_encryption_setting_translate(const char *str)
{
	enum smb_encryption_setting encryption_state = SMB_ENCRYPTION_REQUIRED;
	int32_t val = lpcfg_parse_enum_vals("client smb encrypt", str);

	if (val != INT32_MIN) {
		encryption_state = val;
	}

	return encryption_state;
}