make a more recent snapshot of ldb available to interested

people. Note that I decided to make it LGPL.

ldb is not finished yet, but enough of it is there for people to get
an idea of what it does, and quite a few simple tests work
(This used to be commit dc6f41f9e777d37f883303ddef0d96840d80f78e)

4 files changed, 1167 insertions, 0 deletions

diff --git a/source4/lib/ldb/common/ldb.c b/source4/lib/ldb/common/ldb.c
new file mode 100644
index 0000000000..90b77e1e7f
--- /dev/null
+++ b/source4/lib/ldb/common/ldb.c
@@ -0,0 +1,129 @@
+/* 
+   ldb database library
+
+   Copyright (C) Andrew Tridgell  2004
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library 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 of the License, or (at your option) any later version.
+
+   This library 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
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb core API
+ *
+ *  Description: core API routines interfacing to ldb backends
+ *
+ *  Author: Andrew Tridgell
+ */
+
+#include "includes.h"
+
+/* 
+ connect to a database. The URL can either be one of the following forms
+   ldb://path
+   ldapi://path
+
+   flags is made up of LDB_FLG_*
+
+   the options are passed uninterpreted to the backend, and are
+   backend specific
+*/
+struct ldb_context *ldb_connect(const char *url, unsigned int flags,
+				const char *options[])
+{
+
+	if (strncmp(url, "tdb:", 4) == 0) {
+		return ltdb_connect(url, flags, options);
+	}
+
+	if (strncmp(url, "ldap", 4) == 0) {
+		return lldb_connect(url, flags, options);
+	}
+
+	errno = EINVAL;
+	return NULL;
+}
+
+/*
+  close the connection to the database
+*/
+int ldb_close(struct ldb_context *ldb)
+{
+	return ldb->ops->close(ldb);
+}
+
+
+/*
+  search the database given a LDAP-like search expression
+
+  return the number of records found, or -1 on error
+*/
+int ldb_search(struct ldb_context *ldb, 
+	       const char *base,
+	       enum ldb_scope scope,
+	       const char *expression,
+	       const char *attrs[], struct ldb_message ***res)
+{
+	return ldb->ops->search(ldb, base, scope, expression, attrs, res);
+}
+
+/* 
+   free a set of messages returned by ldb_search
+*/
+int ldb_search_free(struct ldb_context *ldb, struct ldb_message **msgs)
+{
+	return ldb->ops->search_free(ldb, msgs);
+}
+
+
+/*
+  add a record to the database. Will fail if a record with the given class and key
+  already exists
+*/
+int ldb_add(struct ldb_context *ldb, 
+	    const struct ldb_message *message)
+{
+	return ldb->ops->add(ldb, message);
+}
+
+/*
+  modify the specified attributes of a record
+*/
+int ldb_modify(struct ldb_context *ldb, 
+	       const struct ldb_message *message)
+{
+	return ldb->ops->modify(ldb, message);
+}
+
+
+/*
+  delete a record from the database
+*/
+int ldb_delete(struct ldb_context *ldb, const char *dn)
+{
+	return ldb->ops->delete(ldb, dn);
+}
+
+/*
+  return extended error information 
+*/
+const char *ldb_errstring(struct ldb_context *ldb)
+{
+	return ldb->ops->errstring(ldb);
+}
diff --git a/source4/lib/ldb/common/ldb_ldif.c b/source4/lib/ldb/common/ldb_ldif.c
new file mode 100644
index 0000000000..198c984823
--- /dev/null
+++ b/source4/lib/ldb/common/ldb_ldif.c
@@ -0,0 +1,476 @@
+/* 
+   ldb database library
+
+   Copyright (C) Andrew Tridgell  2004
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library 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 of the License, or (at your option) any later version.
+
+   This library 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
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldif routines
+ *
+ *  Description: ldif pack/unpack routines
+ *
+ *  Author: Andrew Tridgell
+ */
+
+#include "includes.h"
+
+
+/*
+  this base64 decoder was taken from jitterbug (written by tridge).
+  we might need to replace it with a new version
+*/
+static int base64_decode(char *s)
+{
+	const char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+	int bit_offset, byte_offset, idx, i, n;
+	unsigned char *d = (unsigned char *)s;
+	char *p;
+
+	n=i=0;
+
+	while (*s && (p=strchr(b64,*s))) {
+		idx = (int)(p - b64);
+		byte_offset = (i*6)/8;
+		bit_offset = (i*6)%8;
+		d[byte_offset] &= ~((1<<(8-bit_offset))-1);
+		if (bit_offset < 3) {
+			d[byte_offset] |= (idx << (2-bit_offset));
+			n = byte_offset+1;
+		} else {
+			d[byte_offset] |= (idx >> (bit_offset-2));
+			d[byte_offset+1] = 0;
+			d[byte_offset+1] |= (idx << (8-(bit_offset-2))) & 0xFF;
+			n = byte_offset+2;
+		}
+		s++; i++;
+	}
+
+	if (*s && !p) {
+		/* the only termination allowed */
+		if (*s != '=') {
+			return -1;
+		}
+	}
+
+	/* null terminate */
+	d[n] = 0;
+	return n;
+}
+
+
+/*
+  encode as base64
+  caller frees
+*/
+char *ldb_base64_encode(const char *buf, int len)
+{
+	const char *b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+	int bit_offset, byte_offset, idx, i;
+	unsigned char *d = (unsigned char *)buf;
+	int bytes = (len*8 + 5)/6;
+	char *out;
+
+	out = malloc(bytes+2);
+	if (!out) return NULL;
+
+	for (i=0;i<bytes;i++) {
+		byte_offset = (i*6)/8;
+		bit_offset = (i*6)%8;
+		if (bit_offset < 3) {
+			idx = (d[byte_offset] >> (2-bit_offset)) & 0x3F;
+		} else {
+			idx = (d[byte_offset] << (bit_offset-2)) & 0x3F;
+			if (byte_offset+1 < len) {
+				idx |= (d[byte_offset+1] >> (8-(bit_offset-2)));
+			}
+		}
+		out[i] = b64[idx];
+	}
+
+	out[i++] = '=';
+	out[i] = 0;
+
+	return out;
+}
+
+/*
+  see if a buffer should be base64 encoded
+*/
+int ldb_should_b64_encode(const struct ldb_val *val)
+{
+	int i;
+	unsigned char *p = val->data;
+
+	if (val->length == 0 || p[0] == ' ' || p[0] == ':') {
+		return 1;
+	}
+
+	for (i=0; i<val->length; i++) {
+		if (!isprint(p[i]) || p[i] == '\n') {
+			return 1;
+		}
+	}
+	return 0;
+}
+
+/* this macro is used to handle the return checking on fprintf_fn() */
+#define CHECK_RET do { if (ret < 0) return ret; total += ret; } while (0)
+
+/*
+  write a line folded string onto a file
+*/
+static int fold_string(int (*fprintf_fn)(void *, const char *, ...), void *private,
+			const char *buf, size_t length, int start_pos)
+{
+	int i;
+	int total=0, ret;
+
+	for (i=0;i<length;i++) {
+		ret = fprintf_fn(private, "%c", buf[i]);
+		CHECK_RET;
+		if (i != (length-1) && (i + start_pos) % 77 == 0) {
+			ret = fprintf_fn(private, "\n ");
+			CHECK_RET;
+		}
+	}
+
+	return total;
+}
+
+/*
+  encode as base64 to a file
+*/
+static int base64_encode_f(int (*fprintf_fn)(void *, const char *, ...), void *private,
+			   const char *buf, int len, int start_pos)
+{
+	char *b = ldb_base64_encode(buf, len);
+	int ret;
+
+	if (!b) {
+		return -1;
+	}
+
+	ret = fold_string(fprintf_fn, private, b, strlen(b), start_pos);
+
+	free(b);
+	return ret;
+}
+
+/*
+  write to ldif, using a caller supplied write method
+*/
+int ldif_write(int (*fprintf_fn)(void *, const char *, ...), 
+	       void *private,
+	       const struct ldb_message *msg)
+{
+	int i;
+	int total=0, ret;
+
+	ret = fprintf_fn(private, "dn: %s\n", msg->dn);
+	CHECK_RET;
+
+	for (i=0;i<msg->num_elements;i++) {
+		if (ldb_should_b64_encode(&msg->elements[i].value)) {
+			ret = fprintf_fn(private, "%s:: ", msg->elements[i].name);
+			CHECK_RET;
+			ret = base64_encode_f(fprintf_fn, private, 
+					      msg->elements[i].value.data, 
+					      msg->elements[i].value.length,
+					      strlen(msg->elements[i].name)+3);
+			CHECK_RET;
+			ret = fprintf_fn(private, "\n");
+			CHECK_RET;
+		} else {
+			ret = fprintf_fn(private, "%s: ", msg->elements[i].name);
+			CHECK_RET;
+			ret = fold_string(fprintf_fn, private,
+					  msg->elements[i].value.data,
+					  msg->elements[i].value.length,
+					  strlen(msg->elements[i].name)+2);
+			CHECK_RET;
+			ret = fprintf_fn(private, "\n");
+			CHECK_RET;
+		}
+	}
+	ret = fprintf_fn(private,"\n");
+	CHECK_RET;
+
+	return total;
+}
+
+#undef CHECK_RET
+
+
+/*
+  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(int (*fgetc_fn)(void *), void *private)
+{
+	size_t alloc_size=0, chunk_size = 0;
+	char *chunk = NULL;
+	int c;
+	int in_comment = 0;
+
+	while ((c = fgetc_fn(private)) != EOF) {
+		if (chunk_size == alloc_size) {
+			char *c2;
+			alloc_size += 1024;
+			c2 = realloc_p(chunk, char, alloc_size);
+			if (!c2) {
+				free(chunk);
+				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;
+	}
+
+	return chunk;
+}
+
+
+/* simple ldif attribute parser */
+static int next_attr(char **s, char **attr, struct ldb_val *value)
+{
+	char *p;
+	int base64_encoded = 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) {
+		int len = base64_decode(value->data);
+		if (len == -1) {
+			/* it wasn't valid base64 data */
+			return -1;
+		}
+		value->length = len;
+	}
+
+	return 0;
+}
+
+
+/*
+  free a message from a ldif_read
+*/
+void ldif_read_free(struct ldb_message *msg)
+{
+	if (msg->elements) free(msg->elements);
+	if (msg->private) free(msg->private);
+	free(msg);
+}
+
+/*
+ read from a LDIF source, creating a ldb_message
+*/
+struct ldb_message *ldif_read(int (*fgetc_fn)(void *), void *private)
+{
+	struct ldb_message *msg;
+	char *attr=NULL, *chunk=NULL, *s;
+	struct ldb_val value;
+
+	value.data = NULL;
+
+	msg = malloc_p(struct ldb_message);
+	if (!msg) return NULL;
+
+	msg->dn = NULL;
+	msg->elements = NULL;
+	msg->num_elements = 0;
+	msg->private = NULL;
+
+	chunk = next_chunk(fgetc_fn, private);
+	if (!chunk) {
+		goto failed;
+	}
+
+	msg->private = chunk;
+	s = chunk;
+
+	if (next_attr(&s, &attr, &value) != 0) {
+		goto failed;
+	}
+	
+	/* first line must be a dn */
+	if (strcmp(attr, "dn") != 0) {
+		fprintf(stderr, "First line must be a dn not '%s'\n", attr);
+		goto failed;
+	}
+
+	msg->dn = value.data;
+
+	while (next_attr(&s, &attr, &value) == 0) {
+		msg->elements = realloc_p(msg->elements, 
+					  struct ldb_message_element, 
+					  msg->num_elements+1);
+		if (!msg->elements) {
+			goto failed;
+		}
+		msg->elements[msg->num_elements].flags = 0;
+		msg->elements[msg->num_elements].name = attr;
+		msg->elements[msg->num_elements].value = value;
+		msg->num_elements++;
+	}
+
+	return msg;
+
+failed:
+	if (msg) ldif_read_free(msg);
+	return NULL;
+}
+
+
+
+/*
+  a wrapper around ldif_read() for reading from FILE*
+*/
+struct ldif_read_file_state {
+	FILE *f;
+};
+
+static int fgetc_file(void *private)
+{
+	struct ldif_read_file_state *state = private;
+	return fgetc(state->f);
+}
+
+struct ldb_message *ldif_read_file(FILE *f)
+{
+	struct ldif_read_file_state state;
+	state.f = f;
+	return ldif_read(fgetc_file, &state);
+}
+
+
+/*
+  a wrapper around ldif_read() for reading from const char*
+*/
+struct ldif_read_string_state {
+	const char *s;
+};
+
+static int fgetc_string(void *private)
+{
+	struct ldif_read_string_state *state = private;
+	if (state->s[0] != 0) {
+		return *state->s++;
+	}
+	return EOF;
+}
+
+struct ldb_message *ldif_read_string(const char *s)
+{
+	struct ldif_read_string_state state;
+	state.s = s;
+	return ldif_read(fgetc_string, &state);
+}
+
+
+/*
+  wrapper around ldif_write() for a file
+*/
+struct ldif_write_file_state {
+	FILE *f;
+};
+
+static int fprintf_file(void *private, const char *fmt, ...)
+{
+	struct ldif_write_file_state *state = private;
+	int ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vfprintf(state->f, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+int ldif_write_file(FILE *f, const struct ldb_message *msg)
+{
+	struct ldif_write_file_state state;
+	state.f = f;
+	return ldif_write(fprintf_file, &state, msg);
+}
diff --git a/source4/lib/ldb/common/ldb_parse.c b/source4/lib/ldb/common/ldb_parse.c
new file mode 100644
index 0000000000..4f8d469e6c
--- /dev/null
+++ b/source4/lib/ldb/common/ldb_parse.c
@@ -0,0 +1,460 @@
+/* 
+   ldb database library
+
+   Copyright (C) Andrew Tridgell  2004
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library 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 of the License, or (at your option) any later version.
+
+   This library 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
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb expression parsing
+ *
+ *  Description: parse LDAP-like search expressions
+ *
+ *  Author: Andrew Tridgell
+ */
+
+/*
+  TODO:
+      - add RFC2254 binary string handling
+      - possibly add ~=, <= and >= handling
+      - expand the test suite
+      - add better parse error handling
+
+*/
+
+#include "includes.h"
+
+
+/*
+a filter is defined by:
+               <filter> ::= '(' <filtercomp> ')'
+               <filtercomp> ::= <and> | <or> | <not> | <simple>
+               <and> ::= '&' <filterlist>
+               <or> ::= '|' <filterlist>
+               <not> ::= '!' <filter>
+               <filterlist> ::= <filter> | <filter> <filterlist>
+               <simple> ::= <attributetype> <filtertype> <attributevalue>
+               <filtertype> ::= '=' | '~=' | '<=' | '>='
+*/
+
+/*
+  return next token element. Caller frees
+*/
+static char *ldb_parse_lex(const char **s)
+{
+	const char *p = *s;
+	char *ret;
+
+	while (isspace(*p)) {
+		p++;
+	}
+	*s = p;
+
+	if (*p == 0) {
+		return NULL;
+	}
+
+	if (strchr("()&|=!", *p)) {
+		(*s) = p+1;
+		ret = strndup(p, 1);
+		if (!ret) {
+			errno = ENOMEM;
+		}
+		return ret;
+	}
+
+	while (*p && (isalnum(*p) || !strchr("()&|=!", *p))) {
+		p++;
+	}
+
+	if (p == *s) {
+		return NULL;
+	}
+
+	ret = strndup(*s, p - *s);
+	if (!ret) {
+		errno = ENOMEM;
+	}
+
+	*s = p;
+
+	return ret;
+}
+
+/*
+  find a matching close brace in a string
+*/
+static const char *match_brace(const char *s)
+{
+	unsigned int count = 0;
+	while (*s && (count != 0 || *s != ')')) {
+		if (*s == '(') {
+			count++;
+		}
+		if (*s == ')') {
+			count--;
+		}
+		s++;
+	}
+	if (! *s) {
+		return NULL;
+	}
+	return s;
+}
+
+
+static struct ldb_parse_tree *ldb_parse_filter(const char **s);
+
+/*
+  <simple> ::= <attributetype> <filtertype> <attributevalue>
+*/
+static struct ldb_parse_tree *ldb_parse_simple(const char *s)
+{
+	char *eq, *val, *l;
+	struct ldb_parse_tree *ret;
+
+	l = ldb_parse_lex(&s);
+	if (!l) {
+		fprintf(stderr, "Unexpected end of expression\n");
+		return NULL;
+	}
+
+	if (strchr("()&|=", *l)) {
+		fprintf(stderr, "Unexpected token '%s'\n", l);
+		free(l);
+		return NULL;
+	}
+
+	eq = ldb_parse_lex(&s);
+	if (!eq || strcmp(eq, "=") != 0) {
+		fprintf(stderr, "Expected '='\n");
+		free(l);
+		if (eq) free(eq);
+		return NULL;
+	}
+	free(eq);
+
+	val = ldb_parse_lex(&s);
+	if (val && strchr("()&|=", *val)) {
+		fprintf(stderr, "Unexpected token '%s'\n", val);
+		free(l);
+		if (val) free(val);
+		return NULL;
+	}
+	
+	ret = malloc_p(struct ldb_parse_tree);
+	if (!ret) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	ret->operation = LDB_OP_SIMPLE;
+	ret->u.simple.attr = l;
+	ret->u.simple.value.data = val;
+	ret->u.simple.value.length = val?strlen(val):0;
+
+	return ret;
+}
+
+
+/*
+  parse a filterlist
+  <and> ::= '&' <filterlist>
+  <or> ::= '|' <filterlist>
+  <filterlist> ::= <filter> | <filter> <filterlist>
+*/
+static struct ldb_parse_tree *ldb_parse_filterlist(enum ldb_parse_op op, const char *s)
+{
+	struct ldb_parse_tree *ret, *next;
+
+	ret = malloc_p(struct ldb_parse_tree);
+	if (!ret) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	ret->operation = op;
+	ret->u.list.num_elements = 1;
+	ret->u.list.elements = malloc_p(struct ldb_parse_tree *);
+	if (!ret->u.list.elements) {
+		errno = ENOMEM;
+		free(ret);
+		return NULL;
+	}
+
+	ret->u.list.elements[0] = ldb_parse_filter(&s);
+	if (!ret->u.list.elements[0]) {
+		free(ret->u.list.elements);
+		free(ret);
+		return NULL;
+	}
+
+	while (isspace(*s)) s++;
+
+	while (*s && (next = ldb_parse_filter(&s))) {
+		struct ldb_parse_tree **e;
+		e = realloc_p(ret->u.list.elements, 
+			      struct ldb_parse_tree *, 
+			      ret->u.list.num_elements+1);
+		if (!e) {
+			errno = ENOMEM;
+			ldb_parse_tree_free(next);
+			ldb_parse_tree_free(ret);
+			return NULL;
+		}
+		ret->u.list.elements = e;
+		ret->u.list.elements[ret->u.list.num_elements] = next;
+		ret->u.list.num_elements++;
+		while (isspace(*s)) s++;
+	}
+
+	return ret;
+}
+
+
+/*
+  <not> ::= '!' <filter>
+*/
+static struct ldb_parse_tree *ldb_parse_not(const char *s)
+{
+	struct ldb_parse_tree *ret;
+
+	ret = malloc_p(struct ldb_parse_tree);
+	if (!ret) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	ret->operation = LDB_OP_NOT;
+	ret->u.not.child = ldb_parse_filter(&s);
+	if (!ret->u.not.child) {
+		free(ret);
+		return NULL;
+	}
+
+	return ret;
+}
+
+/*
+  parse a filtercomp
+  <filtercomp> ::= <and> | <or> | <not> | <simple>
+*/
+static struct ldb_parse_tree *ldb_parse_filtercomp(const char *s)
+{
+	while (isspace(*s)) s++;
+
+	switch (*s) {
+	case '&':
+		return ldb_parse_filterlist(LDB_OP_AND, s+1);
+
+	case '|':
+		return ldb_parse_filterlist(LDB_OP_OR, s+1);
+
+	case '!':
+		return ldb_parse_not(s+1);
+
+	case '(':
+	case ')':
+		fprintf(stderr, "Unexpected token '%c'\n", *s);
+		return NULL;
+	}
+
+	return ldb_parse_simple(s);
+}
+
+
+/*
+  <filter> ::= '(' <filtercomp> ')'
+*/
+static struct ldb_parse_tree *ldb_parse_filter(const char **s)
+{
+	char *l, *s2;
+	const char *p, *p2;
+	struct ldb_parse_tree *ret;
+
+	l = ldb_parse_lex(s);
+	if (!l) {
+		fprintf(stderr, "Unexpected end of expression\n");
+		return NULL;
+	}
+
+	if (strcmp(l, "(") != 0) {
+		free(l);
+		fprintf(stderr, "Expected '('\n");
+		return NULL;
+	}
+	free(l);
+
+	p = match_brace(*s);
+	if (!p) {
+		fprintf(stderr, "Parse error - mismatched braces\n");
+		return NULL;
+	}
+	p2 = p + 1;
+
+	s2 = strndup(*s, p - *s);
+	if (!s2) {
+		errno = ENOMEM;
+		return NULL;
+	}
+
+	ret = ldb_parse_filtercomp(s2);
+	free(s2);
+
+	*s = p2;
+
+	return ret;
+}
+
+
+/*
+  main parser entry point. Takes a search string and returns a parse tree
+
+  expression ::= <simple> | <filter>
+*/
+struct ldb_parse_tree *ldb_parse_tree(const char *s)
+{
+	while (isspace(*s)) s++;
+
+	if (*s == '(') {
+		return ldb_parse_filter(&s);
+	}
+
+	return ldb_parse_simple(s);
+}
+
+/*
+  free a parse tree returned from ldb_parse_tree()
+*/
+void ldb_parse_tree_free(struct ldb_parse_tree *tree)
+{
+	int i;
+
+	switch (tree->operation) {
+	case LDB_OP_SIMPLE:
+		free(tree->u.simple.attr);
+		if (tree->u.simple.value.data) free(tree->u.simple.value.data);
+		break;
+
+	case LDB_OP_AND:
+	case LDB_OP_OR:
+		for (i=0;i<tree->u.list.num_elements;i++) {
+			ldb_parse_tree_free(tree->u.list.elements[i]);
+		}
+		if (tree->u.list.elements) free(tree->u.list.elements);
+		break;
+
+	case LDB_OP_NOT:
+		ldb_parse_tree_free(tree->u.not.child);
+		break;
+	}
+
+	free(tree);
+}
+
+#if TEST_PROGRAM
+/*
+  return a string representation of a parse tree
+  used for debugging
+*/
+static char *tree_string(struct ldb_parse_tree *tree)
+{
+	char *s = NULL;
+	char *s1, *s2;
+	int i;
+
+	switch (tree->operation) {
+	case LDB_OP_SIMPLE:
+		asprintf(&s, "( %s = \"%s\" )", tree->u.simple.attr, 
+			 (char *)tree->u.simple.value.data);
+		break;
+
+	case LDB_OP_AND:
+	case LDB_OP_OR:
+		asprintf(&s, "( %c", tree->operation==LDB_OP_AND?'&':'|');
+		if (!s) return NULL;
+
+		for (i=0;i<tree->u.list.num_elements;i++) {
+			s1 = tree_string(tree->u.list.elements[i]);
+			if (!s1) {
+				free(s);
+				return NULL;
+			}
+			asprintf(&s2, "%s %s", s, s1);
+			free(s);
+			free(s1);
+			s = s2;
+		}
+		if (!s) {
+			return NULL;
+		}
+		asprintf(&s2, "%s )", s);
+		free(s);
+		s = s2;
+		break;
+
+	case LDB_OP_NOT:
+		s1 = tree_string(tree->u.not.child);
+		asprintf(&s, "( ! %s )", s1);
+		free(s1);
+		break;
+	}
+	return s;
+}
+
+
+/*
+  print a tree
+ */
+static void print_tree(struct ldb_parse_tree *tree)
+{
+	char *s = tree_string(tree);
+	printf("%s\n", s);
+	free(s);
+}
+
+
+ int main(void)
+{
+	char line[1000];
+	int ret = 0;
+
+	while (fgets(line, sizeof(line)-1, stdin)) {
+		struct ldb_parse_tree *tree;
+
+		if (line[strlen(line)-1] == '\n') {
+			line[strlen(line)-1] = 0;
+		}
+		tree = ldb_parse_tree(line);
+		if (!tree) {
+			fprintf(stderr, "Failed to parse\n");
+			ret = 1;
+			continue;
+		}
+		print_tree(tree);
+		ldb_parse_tree_free(tree);
+	}
+	
+	return ret;
+}
+#endif /* TEST_PROGRAM */
+
diff --git a/source4/lib/ldb/common/util.c b/source4/lib/ldb/common/util.c
new file mode 100644
index 0000000000..d198a1ad92
--- /dev/null
+++ b/source4/lib/ldb/common/util.c
@@ -0,0 +1,102 @@
+/* 
+   ldb database library
+
+   Copyright (C) Andrew Tridgell  2004
+
+     ** NOTE! The following LGPL license applies to the ldb
+     ** library. This does NOT imply that all of Samba is released
+     ** under the LGPL
+   
+   This library 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 of the License, or (at your option) any later version.
+
+   This library 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
+*/
+
+/*
+ *  Name: ldb
+ *
+ *  Component: ldb utility functions
+ *
+ *  Description: miscellanous utility functions for ldb
+ *
+ *  Author: Andrew Tridgell
+ */
+
+#include "includes.h"
+
+
+#define MAX_MALLOC_SIZE 0x7fffffff
+
+/*
+  realloc an array, checking for integer overflow in the array size
+*/
+void *realloc_array(void *ptr, size_t el_size, unsigned count)
+{
+	if (count == 0 ||
+	    count >= MAX_MALLOC_SIZE/el_size) {
+		return NULL;
+	}
+	if (!ptr) {
+		return malloc(el_size * count);
+	}
+	return realloc(ptr, el_size * count);
+}
+
+
+/*
+  find an element in a list, using the given comparison function and
+  assuming that the list is already sorted using comp_fn
+
+  return -1 if not found, or the index of the first occurance of needle if found
+*/
+int list_find(const void *needle, 
+	      const void *base, size_t nmemb, size_t size, comparison_fn_t comp_fn)
+{
+	const char *base_p = base;
+	size_t min_i, max_i, test_i;
+
+	if (nmemb == 0) {
+		return -1;
+	}
+
+	min_i = 0;
+	max_i = nmemb-1;
+
+	while (min_i < max_i) {
+		size_t test_t;
+		int r;
+
+		test_i = (min_i + max_i) / 2;
+		r = comp_fn(needle, *(void **)(base_p + (size * test_i)));
+		if (r == 0) {
+			/* scan back for first element */
+			while (test_t > 0 &&
+			       comp_fn(needle, *(void **)(base_p + (size * (test_i-1)))) == 0) {
+				test_i--;
+			}
+			return test_i;
+		}
+		if (r == -1) {
+			max_i = test_i - 1;
+		}
+		if (r == 1) {
+			min_i = test_i + 1;
+		}
+	}
+
+	if (comp_fn(needle, *(void **)(base_p + (size * min_i))) == 0) {
+		return min_i;
+	}
+
+	return -1;
+}