/* 
   Unix SMB/CIFS mplementation.
   LDAP protocol helper functions for SAMBA
   
   Copyright (C) Andrew Tridgell  2004
    
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
   
*/

#include "includes.h"

/****************************************************************************
 *
 * LDIF parser
 *
 * Shamelessly stolen and adapted from ldb.
 *
 ***************************************************************************/

/*
  pull a ldif chunk, which is defined as a piece of data ending in \n\n or EOF
  this routine removes any RFC2849 continuations and comments

  caller frees
*/
static char *next_chunk(TALLOC_CTX *mem_ctx,
			int (*fgetc_fn)(void *), void *private_data)
{
	size_t alloc_size=0, chunk_size = 0;
	char *chunk = NULL;
	int c;
	int in_comment = 0;

	while ((c = fgetc_fn(private_data)) != EOF) {
		if (chunk_size+1 >= alloc_size) {
			char *c2;
			alloc_size += 1024;
			c2 = talloc_realloc(mem_ctx, chunk, alloc_size);
			if (!c2) {
				errno = ENOMEM;
				return NULL;
			}
			chunk = c2;
		}

		if (in_comment) {
			if (c == '\n') {
				in_comment = 0;
			}
			continue;			
		}
		
		/* handle continuation lines - see RFC2849 */
		if (c == ' ' && chunk_size > 1 &&
		    chunk[chunk_size-1] == '\n') {
			chunk_size--;
			continue;
		}
		
		/* chunks are terminated by a double line-feed */
		if (c == '\n' && chunk_size > 0 &&
		    chunk[chunk_size-1] == '\n') {
			chunk[chunk_size-1] = 0;
			return chunk;
		}

		if (c == '#' &&
		    (chunk_size == 0 || chunk[chunk_size-1] == '\n')) {
			in_comment = 1;
			continue;
		}

		/* ignore leading blank lines */
		if (chunk_size == 0 && c == '\n') {
			continue;
		}

		chunk[chunk_size++] = c;
	}

	if (chunk) {
		chunk[chunk_size] = 0;
	}

	return chunk;
}

/* simple ldif attribute parser */
static int next_attr(char **s, const char **attr, struct ldap_val *value)
{
	char *p;
	int base64_encoded = 0;

	if (strncmp(*s, "-\n", 2) == 0) {
		value->length = 0;
		*attr = "-";
		*s += 2;
		return 0;
	}

	p = strchr(*s, ':');
	if (!p) {
		return -1;
	}

	*p++ = 0;

	if (*p == ':') {
		base64_encoded = 1;
		p++;
	}

	*attr = *s;

	while (isspace(*p)) {
		p++;
	}

	value->data = p;

	p = strchr(p, '\n');

	if (!p) {
		value->length = strlen((char *)value->data);
		*s = ((char *)value->data) + value->length;
	} else {
		value->length = p - (char *)value->data;
		*s = p+1;
		*p = 0;
	}

	if (base64_encoded) {
		DATA_BLOB blob = base64_decode_data_blob(value->data);
		memcpy(value->data, blob.data, blob.length);
		value->length = blob.length;
		((char *)value->data)[value->length] = '\0';
	}

	return 0;
}

BOOL add_value_to_attrib(TALLOC_CTX *mem_ctx, struct ldap_val *value,
			 struct ldap_attribute *attrib)
{
	attrib->values = talloc_realloc_p(mem_ctx, 
					  attrib->values,
					  DATA_BLOB,
					  attrib->num_values+1);
	if (attrib->values == NULL)
		return False;

	attrib->values[attrib->num_values] =
		data_blob_talloc(mem_ctx, value->data, value->length);
	attrib->num_values += 1;
	return True;
}

BOOL add_attrib_to_array_talloc(TALLOC_CTX *mem_ctx,
				       const struct ldap_attribute *attrib,
				       struct ldap_attribute **attribs,
				       int *num_attribs)
{
	*attribs = talloc_realloc_p(mem_ctx,
				    *attribs,
				    struct ldap_attribute,
				    *num_attribs+1);

	if (*attribs == NULL)
		return False;

	(*attribs)[*num_attribs] = *attrib;
	*num_attribs += 1;
	return True;
}

static BOOL fill_add_attributes(struct ldap_message *msg, char **chunk)
{
	struct ldap_AddRequest *r = &msg->r.AddRequest;
	const char *attr_name;
	struct ldap_val value;

	r->num_attributes = 0;
	r->attributes = NULL;

	while (next_attr(chunk, &attr_name, &value) == 0) {
		int i;
		struct ldap_attribute *attrib = NULL;
		
		for (i=0; i<r->num_attributes; i++) {
			if (strequal(r->attributes[i].name, attr_name)) {
				attrib = &r->attributes[i];
				break;
			}
		}

		if (attrib == NULL) {
			r->attributes = talloc_realloc_p(msg->mem_ctx,
							 r->attributes,
							 struct ldap_attribute,
							 r->num_attributes+1);
			if (r->attributes == NULL)
				return False;

			attrib = &(r->attributes[r->num_attributes]);
			r->num_attributes += 1;
			ZERO_STRUCTP(attrib);
			attrib->name = talloc_strdup(msg->mem_ctx,
						     attr_name);
		}

		if (!add_value_to_attrib(msg->mem_ctx, &value, attrib))
			return False;
	}
	return True;
}

BOOL add_mod_to_array_talloc(TALLOC_CTX *mem_ctx,
				    struct ldap_mod *mod,
				    struct ldap_mod **mods,
				    int *num_mods)
{
	*mods = talloc_realloc_p(mem_ctx, *mods, struct ldap_mod, (*num_mods)+1);

	if (*mods == NULL)
		return False;

	(*mods)[*num_mods] = *mod;
	*num_mods += 1;
	return True;
}

static BOOL fill_mods(struct ldap_message *msg, char **chunk)
{
	struct ldap_ModifyRequest *r = &msg->r.ModifyRequest;
	const char *attr_name;
	struct ldap_val value;

	r->num_mods = 0;
	r->mods = NULL;

	while (next_attr(chunk, &attr_name, &value) == 0) {

		struct ldap_mod mod;
		mod.type = LDAP_MODIFY_NONE;

		mod.attrib.name = talloc_strdup(msg->mem_ctx, value.data);

		if (strequal(attr_name, "add"))
			mod.type = LDAP_MODIFY_ADD;

		if (strequal(attr_name, "delete"))
			mod.type = LDAP_MODIFY_DELETE;

		if (strequal(attr_name, "replace"))
			mod.type = LDAP_MODIFY_REPLACE;

		if (mod.type == LDAP_MODIFY_NONE) {
			DEBUG(2, ("ldif modification type %s unsupported\n",
				  attr_name));
			return False;
		}

		mod.attrib.num_values = 0;
		mod.attrib.values = NULL;

		while (next_attr(chunk, &attr_name, &value) == 0) {
			if (strequal(attr_name, "-"))
				break;
			if (!strequal(attr_name, mod.attrib.name)) {
				DEBUG(3, ("attrib name %s does not "
					  "match %s\n", attr_name,
					  mod.attrib.name));
				return False;
			}
			if (!add_value_to_attrib(msg->mem_ctx, &value,
						 &mod.attrib)) {
				DEBUG(3, ("Could not add value\n"));
				return False;
			}
		}

		if (!add_mod_to_array_talloc(msg->mem_ctx, &mod, &r->mods,
					     &r->num_mods))
			return False;
	}

	return True;
}

/*
 read from a LDIF source, creating a ldap_message
*/
static struct ldap_message *ldif_read(int (*fgetc_fn)(void *),
				      void *private_data)
{
	struct ldap_message *msg;
	const char *attr=NULL;
	const char *dn;
	char *chunk=NULL, *s;
	struct ldap_val value;

	value.data = NULL;

	msg = new_ldap_message();
	if (msg == NULL)
		return NULL;

	chunk = next_chunk(msg->mem_ctx, fgetc_fn, private_data);
	if (!chunk) {
		goto failed;
	}

	s = chunk;

	if (next_attr(&s, &attr, &value) != 0) {
		goto failed;
	}
	
	/* first line must be a dn */
	if (!strequal(attr, "dn")) {
		DEBUG(5, ("Error: First line of ldif must be a dn not '%s'\n",
			  attr));
		goto failed;
	}

	dn = talloc_strdup(msg->mem_ctx, value.data);

	if (next_attr(&s, &attr, &value) != 0) {
		goto failed;
	}

	if (!strequal(attr, "changetype")) {
		DEBUG(5, ("Error: Second line of ldif must be a changetype "
			  "not '%s'\n",  attr));
		goto failed;
	}

	if (strequal(value.data, "delete")) {
		msg->type = LDAP_TAG_DeleteRequest;
		msg->r.DeleteRequest.dn = dn;
		return msg;
	}

	if (strequal(value.data, "add")) {
		msg->type = LDAP_TAG_AddRequest;

		msg->r.AddRequest.dn = dn;

		if (!fill_add_attributes(msg, &s))
			goto failed;

		return msg;
	}

	if (strequal(value.data, "modify")) {
		msg->type = LDAP_TAG_ModifyRequest;

		msg->r.ModifyRequest.dn = dn;

		if (!fill_mods(msg, &s))
			goto failed;

		return msg;
	}

	DEBUG(3, ("changetype %s not supported\n", (char *)value.data));

failed:
	destroy_ldap_message(msg);
	return NULL;
}

/*
  a wrapper around ldif_read() for reading from const char*
*/
struct ldif_read_string_state {
	const char *s;
};

static int fgetc_string(void *private_data)
{
	struct ldif_read_string_state *state = private_data;
	if (state->s[0] != 0) {
		return *state->s++;
	}
	return EOF;
}

struct ldap_message *ldap_ldif2msg(const char *s)
{
	struct ldif_read_string_state state;
	state.s = s;
	return ldif_read(fgetc_string, &state);
}