/*

  File: __acl_to_any_text.c

  Copyright (C) 1999, 2000

  Andreas Gruenbacher, <a.gruenbacher@bestbits.at>

  This program is free software; you can redistribute it and/or

  modify it under the terms of the GNU Lesser General Public

  License as published by the Free Software Foundation; either

  version 2.1 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

  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public

  License along with this library; if not, write to the Free Software

  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

*/

#include "config.h"

#include <stdio.h>

#include <errno.h>

#include <string.h>

#include <pwd.h>

#include <grp.h>

#include "libacl.h"

#include "misc.h"

static ssize_t acl_entry_to_any_str(const acl_entry_t entry_d, char *text_p,

				    ssize_t size, const acl_entry_t mask_d,

				    const char *prefix, int options);

static ssize_t snprint_uint(char *text_p, ssize_t size, unsigned int i);

static const char *user_name(uid_t uid);

static const char *group_name(gid_t uid);

char *

__acl_to_any_text(acl_t acl, ssize_t *len_p, const char *prefix,

		  char separator, const char *suffix, int options)

{

	acl_obj *acl_obj_p = ext2int(acl, acl);

	ssize_t size, len = 0, entry_len = 0,

		suffix_len = suffix ? strlen(suffix) : 0;

	string_obj *string_obj_p, *tmp;

	acl_entry_obj *entry_obj_p, *mask_obj_p = NULL;

	if (!acl_obj_p)

		return NULL;

	size = acl->a_used * 15 + 1;

	string_obj_p = new_var_obj_p(string, size);

	if (!string_obj_p)

		return NULL;

	if (options & (TEXT_SOME_EFFECTIVE|TEXT_ALL_EFFECTIVE)) {

		/* fetch the ACL_MASK entry */

		FOREACH_ACL_ENTRY(entry_obj_p, acl_obj_p) {

			if (entry_obj_p->etag == ACL_MASK) {

				mask_obj_p = entry_obj_p;

				break;

			}

		}

	}

	FOREACH_ACL_ENTRY(entry_obj_p, acl_obj_p) {

	repeat:

		entry_len = acl_entry_to_any_str(int2ext(entry_obj_p),

		                                 string_obj_p->sstr + len,

						 size-len,

						 int2ext(mask_obj_p),

						 prefix,

						 options);

		if (entry_len < 0)

			goto fail;

		else if (len + entry_len + suffix_len + 1 > size) {

			while (len + entry_len + suffix_len + 1 > size)

				size <<= 1;

			tmp = realloc_var_obj_p(string, string_obj_p, size);

			if (tmp == NULL)

				goto fail;

			string_obj_p = tmp;

			goto repeat;

		} else

			len += entry_len;

		string_obj_p->sstr[len] = separator;

		len++;

	}

	if (len)

		len--;

	if (len && suffix) {

		strcpy(string_obj_p->sstr + len, suffix);

		len += suffix_len;

	} else

		string_obj_p->sstr[len] = '\0';

	if (len_p)

		*len_p = len;

	return (char *)int2ext(string_obj_p);

fail:

	free_obj_p(string_obj_p);

	return NULL;

}

#define ADVANCE(x) \

	text_p += (x); \

	size -= (x); \

	if (size < 0) \

		size = 0;

#define ABBREV(s, str_len) \

	if (options & TEXT_ABBREVIATE) { \

		if (size > 0) \

			text_p[0] = *(s); \

		if (size > 1) \

			text_p[1] = ':'; \

		ADVANCE(2); \

	} else { \

		strncpy(text_p, (s), size); \

		ADVANCE(str_len); \

	}

#define EFFECTIVE_STR		"#effective:"

static ssize_t

acl_entry_to_any_str(const acl_entry_t entry_d, char *text_p, ssize_t size,

	const acl_entry_t mask_d, const char *prefix, int options)

{

	#define TABS 4

	static const char *tabs = "\t\t\t\t";

	acl_entry_obj *entry_obj_p = ext2int(acl_entry, entry_d);

	acl_entry_obj *mask_obj_p = NULL;

	permset_t effective;

	acl_tag_t type;

	ssize_t x;

	const char *orig_text_p = text_p, *str;

	if (!entry_obj_p)

		return -1;

	if (mask_d) {

		mask_obj_p = ext2int(acl_entry, mask_d);

		if (!mask_obj_p)

			return -1;

	}

	if (text_p == NULL)

		size = 0;

	if (prefix) {

		strncpy(text_p, prefix, size);

		ADVANCE(strlen(prefix));

	}

	type = entry_obj_p->etag;

	switch (type) {

		case ACL_USER_OBJ:  /* owner */

			mask_obj_p = NULL;

			/* fall through */

		case ACL_USER:  /* additional user */

			ABBREV("user:", 5);

			if (type == ACL_USER) {

				if (options & TEXT_NUMERIC_IDS)

					str = NULL;

				else

					str = __acl_quote(user_name(

						entry_obj_p->eid.qid), ":, \t\n\r");

				if (str != NULL) {

					strncpy(text_p, str, size);

					ADVANCE(strlen(str));

				} else {

					x = snprint_uint(text_p, size,

					             entry_obj_p->eid.qid);

					ADVANCE(x);

				}

			}

			if (size > 0)

				*text_p = ':';

			ADVANCE(1);

			break;

		case ACL_GROUP_OBJ:  /* owning group */

		case ACL_GROUP:  /* additional group */

			ABBREV("group:", 6);

			if (type == ACL_GROUP) {

				if (options & TEXT_NUMERIC_IDS)

					str = NULL;

				else

					str = __acl_quote(group_name(

						entry_obj_p->eid.qid), ":, \t\n\r");

				if (str != NULL) {

					strncpy(text_p, str, size);

					ADVANCE(strlen(str));

				} else {

					x = snprint_uint(text_p, size,

					             entry_obj_p->eid.qid);

					ADVANCE(x);

				}

			}

			if (size > 0)

				*text_p = ':';

			ADVANCE(1);

			break;

		case ACL_MASK:  /* acl mask */

			mask_obj_p = NULL;

			ABBREV("mask:", 5);

			if (size > 0)

				*text_p = ':';

			ADVANCE(1);

			break;

		case ACL_OTHER:  /* other users */

			mask_obj_p = NULL;

			/* fall through */

			ABBREV("other:", 6);

			if (size > 0)

				*text_p = ':';

			ADVANCE(1);

			break;

		default:

			return 0;

	}

	switch ((size >= 3) ? 3 : size) {

		case 3:

			text_p[2] = (entry_obj_p->eperm.sperm &

			             ACL_EXECUTE) ? 'x' : '-'; 

			/* fall through */

		case 2:

			text_p[1] = (entry_obj_p->eperm.sperm &

			             ACL_WRITE) ? 'w' : '-'; 

			/* fall through */

		case 1:

			text_p[0] = (entry_obj_p->eperm.sperm &

			             ACL_READ) ? 'r' : '-'; 

			break;

	}

	ADVANCE(3);

	if (mask_obj_p &&

	    (options & (TEXT_SOME_EFFECTIVE|TEXT_ALL_EFFECTIVE))) {

		mask_obj_p = ext2int(acl_entry, mask_d);

		if (!mask_obj_p)

			return -1;

		effective = entry_obj_p->eperm.sperm &

		                 mask_obj_p->eperm.sperm;

		if (effective != entry_obj_p->eperm.sperm ||

		    options & TEXT_ALL_EFFECTIVE) {

			x = (options & TEXT_SMART_INDENT) ?

				((text_p - orig_text_p)/8) : TABS-1;

			/* use at least one tab for indentation */

			if (x > (TABS-1))

				x = (TABS-1);

			strncpy(text_p, tabs+x, size);

			ADVANCE(TABS-x);

			strncpy(text_p, EFFECTIVE_STR, size);

			ADVANCE(sizeof(EFFECTIVE_STR)-1);

			switch ((size >= 3) ? 3 : size) {

				case 3:

					text_p[2] = (effective &

						     ACL_EXECUTE) ? 'x' : '-'; 

					/* fall through */

				case 2:

					text_p[1] = (effective &

						     ACL_WRITE) ? 'w' : '-'; 

					/* fall through */

				case 1:

					text_p[0] = (effective &

						     ACL_READ) ? 'r' : '-'; 

					break;

			}

			ADVANCE(3);

		}

	}

	/* zero-terminate string (but don't count '\0' character) */

	if (size > 0)

		*text_p = '\0';

	return (text_p - orig_text_p);  /* total size required, excluding

	                                   final NULL character. */

}

#undef ADVANCE

/*

  This function is equivalent to the proposed changes to snprintf:

    snprintf(text_p, size, "%u", i)

  (The current snprintf returns -1 if the buffer is too small; the proposal

   is to return the number of characters that would be required. See the

   snprintf manual page.)

*/

static ssize_t

snprint_uint(char *text_p, ssize_t size, unsigned int i)

{

	unsigned int tmp = i;

	int digits = 1;

	unsigned int factor = 1;

	while ((tmp /= 10) != 0) {

		digits++;

		factor *= 10;

	}

	if (size && (i == 0)) {

		*text_p++ = '0';

	} else {

		while (size > 0 && factor > 0) {

			*text_p++ = '0' + (i / factor);

			size--;

			i %= factor;

			factor /= 10;

		}

	}

	if (size)

		*text_p = '\0';

	return digits;

}

static const char *

user_name(uid_t uid)

{

	struct passwd *passwd = getpwuid(uid);

	if (passwd != NULL)

		return passwd->pw_name;

	else

		return NULL;

}

static const char *

group_name(gid_t gid)

{

	struct group *group = getgrgid(gid);

	if (group != NULL)

		return group->gr_name;

	else

		return NULL;

}