s4:ldb: add infrastructure for extended dn handlers

This introduces a new set of pluggable syntax, for use on the
extended DN, and uses them when parsing the DN.

If the DN appears to be in the extended form, we no longer return the
full DN 'as is', but only return the normal part from
ldb_dn_get_linearized().

When validating/parsing the DN we validate not only the format of the
DN, but also the contents of the GUID or SID (to ensure they are
plausable).

We also have functions to set and get the extended components on the DN.

For now, extended_dn_get_linearized() returns a newly constructed and
allocated string each time.

Signed-off-by: Stefan Metzmacher <metze@samba.org>

2 files changed, 442 insertions, 58 deletions

diff --git a/source4/lib/ldb/common/ldb_attributes.c b/source4/lib/ldb/common/ldb_attributes.c
index 747f241781..48f9e11caf 100644
--- a/source4/lib/ldb/common/ldb_attributes.c
+++ b/source4/lib/ldb/common/ldb_attributes.c
@@ -225,3 +225,50 @@ int ldb_setup_wellknown_attributes(struct ldb_context *ldb)
 	return LDB_SUCCESS;
 }
 
+
+/*
+  add a extended dn syntax to the ldb_schema
+*/
+int ldb_dn_extended_add_syntax(struct ldb_context *ldb, 
+			       unsigned flags,
+			       const struct ldb_dn_extended_syntax *syntax)
+{
+	int n;
+	struct ldb_dn_extended_syntax *a;
+
+	if (!syntax) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	n = ldb->schema.num_dn_extended_syntax + 1;
+
+	a = talloc_realloc(ldb, ldb->schema.dn_extended_syntax,
+			   struct ldb_dn_extended_syntax, n);
+
+	if (!a) {
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+
+	a[ldb->schema.num_dn_extended_syntax] = *syntax;
+	ldb->schema.dn_extended_syntax = a;
+
+	ldb->schema.num_dn_extended_syntax = n;
+
+	return 0;
+}
+
+/*
+  return the extended dn syntax for a given name
+*/
+const struct ldb_dn_extended_syntax *ldb_dn_extended_syntax_by_name(struct ldb_context *ldb,
+								    const char *name)
+{
+	int i;
+	for (i=0; i < ldb->schema.num_dn_extended_syntax; i++) {
+		if (ldb_attr_cmp(ldb->schema.dn_extended_syntax[i].name, name) == 0) {
+			return &ldb->schema.dn_extended_syntax[i];
+		}
+	}
+	return NULL;
+}
+
diff --git a/source4/lib/ldb/common/ldb_dn.c b/source4/lib/ldb/common/ldb_dn.c
index e36aea4e69..13c01f4e70 100644
--- a/source4/lib/ldb/common/ldb_dn.c
+++ b/source4/lib/ldb/common/ldb_dn.c
@@ -52,6 +52,12 @@ struct ldb_dn_component {
 	struct ldb_val cf_value;
 };
 
+struct ldb_dn_extended_component {
+
+	char *name;
+	struct ldb_val value;
+};
+
 struct ldb_dn {
 
 	struct ldb_context *ldb;
@@ -63,11 +69,14 @@ struct ldb_dn {
 	bool valid_case;
 
 	char *linearized;
+	char *extended_linearized;
 	char *casefold;
 
 	unsigned int comp_num;
 	struct ldb_dn_component *components;
 
+	unsigned int extended_comp_num;
+	struct ldb_dn_extended_component *extended_components;
 };
 
 /* strdn may be NULL */
@@ -85,28 +94,34 @@ struct ldb_dn *ldb_dn_from_ldb_val(void *mem_ctx, struct ldb_context *ldb, const
 	if (strdn->data && strdn->length) {
 		if (strdn->data[0] == '@') {
 			dn->special = true;
+		} 
+		dn->extended_linearized = talloc_strndup(dn, (const char *)strdn->data, strdn->length);
+		LDB_DN_NULL_FAILED(dn->extended_linearized);
+	
+		if (strdn->data[0] == '<') {
+			const char *p_save, *p = dn->extended_linearized;
+			do {
+				p_save = p;
+				p = strstr(p, ">;");
+				if (p) {
+					p = p + 2;
+				}
+			} while (p);
+			
+			if (p_save == dn->extended_linearized) {
+				dn->linearized = talloc_strdup(dn, "");
+			} else {
+				dn->linearized = talloc_strdup(dn, p_save);
+			}
+			LDB_DN_NULL_FAILED(dn->linearized);
+		} else {
+			dn->linearized = dn->extended_linearized;
+			dn->extended_linearized = NULL;
 		}
-		if (strdn->length >= 6 && strncasecmp((const char *)strdn->data, "<GUID=", 6) == 0) {
-			/* this is special DN returned when the
-			 * exploded_dn control is used */
-			dn->special = true;
-			/* FIXME: add a GUID string to ldb_dn structure */
-		} else if (strdn->length >= 5 && strncasecmp((const char *)strdn->data, "<SID=", 5) == 0) {
-			/* this is special DN returned when the
-			 * exploded_dn control is used */
-			dn->special = true;
-			/* FIXME: add a SID string to ldb_dn structure */
-		} else if (strdn->length >= 8 && strncasecmp((const char *)strdn->data, "<WKGUID=", 8) == 0) {
-			/* this is special DN returned when the
-			 * exploded_dn control is used */
-			dn->special = true;
-			/* FIXME: add a WKGUID string to ldb_dn structure */
-		}
-		dn->linearized = talloc_strndup(dn, (const char *)strdn->data, strdn->length);
 	} else {
 		dn->linearized = talloc_strdup(dn, "");
+		LDB_DN_NULL_FAILED(dn->linearized);
 	}
-	LDB_DN_NULL_FAILED(dn->linearized);
 
 	return dn;
 
@@ -126,47 +141,21 @@ struct ldb_dn *ldb_dn_new(void *mem_ctx, struct ldb_context *ldb, const char *st
 
 struct ldb_dn *ldb_dn_new_fmt(void *mem_ctx, struct ldb_context *ldb, const char *new_fmt, ...)
 {
-	struct ldb_dn *dn;
 	char *strdn;
 	va_list ap;
 
 	if ( (! mem_ctx) || (! ldb)) return NULL;
 
-	dn = talloc_zero(mem_ctx, struct ldb_dn);
-	LDB_DN_NULL_FAILED(dn);
-
-	dn->ldb = ldb;
-
 	va_start(ap, new_fmt);
-	strdn = talloc_vasprintf(dn, new_fmt, ap);
+	strdn = talloc_vasprintf(mem_ctx, new_fmt, ap);
 	va_end(ap);
-	LDB_DN_NULL_FAILED(strdn);
-
-	if (strdn[0] == '@') {
-		dn->special = true;
-	}
-	if (strncasecmp(strdn, "<GUID=", 6) == 0) {
-		/* this is special DN returned when the
-		 * exploded_dn control is used */
-		dn->special = true;
-		/* FIXME: add a GUID string to ldb_dn structure */
-	} else if (strncasecmp(strdn, "<SID=", 5) == 0) {
-		/* this is special DN returned when the
-		 * exploded_dn control is used */
-		dn->special = true;
-		/* FIXME: add a SID string to ldb_dn structure */
-	} else if (strncasecmp(strdn, "<WKGUID=", 8) == 0) {
-		/* this is special DN returned when the
-		 * exploded_dn control is used */
-		dn->special = true;
-		/* FIXME: add a WKGUID string to ldb_dn structure */
-	}
-	dn->linearized = strdn;
 
-	return dn;
-
-failed:
-	talloc_free(dn);
+	if (strdn) {
+		struct ldb_dn *dn = ldb_dn_new(mem_ctx, ldb, strdn);
+		talloc_free(strdn);
+		return dn;
+	}
+	
 	return NULL;
 }
 
@@ -235,15 +224,19 @@ char *ldb_dn_escape_value(void *mem_ctx, struct ldb_val value)
 */
 static bool ldb_dn_explode(struct ldb_dn *dn)
 {
-	char *p, *data, *d, *dt, *t;
+	char *p, *ex_name, *ex_value, *data, *d, *dt, *t;
 	bool trim = false;
+	bool in_extended = false;
+	bool in_ex_name = false;
+	bool in_ex_value = false;
 	bool in_attr = false;
 	bool in_value = false;
 	bool in_quote = false;
 	bool is_oid = false;
 	bool escape = false;
 	unsigned x;
-	int l;
+	int l, ret;
+	char *parse_dn;
 
 	if ( ! dn || dn->invalid) return false;
 
@@ -251,12 +244,18 @@ static bool ldb_dn_explode(struct ldb_dn *dn)
 		return true;
 	}
 
-	if ( ! dn->linearized) {
+	if (dn->extended_linearized) {
+		parse_dn = dn->extended_linearized;
+	} else {
+		parse_dn = dn->linearized;
+	}
+
+	if ( ! parse_dn ) {
 		return false;
 	}
 
 	/* Empty DNs */
-	if (dn->linearized[0] == '\0') {
+	if (parse_dn[0] == '\0') {
 		return true;
 	}
 
@@ -268,6 +267,9 @@ static bool ldb_dn_explode(struct ldb_dn *dn)
 	/* make sure we free this if alloced previously before replacing */
 	talloc_free(dn->components);
 
+	talloc_free(dn->extended_components);
+	dn->extended_components = NULL;
+
 	/* in the common case we have 3 or more components */
 	/* make sure all components are zeroed, other functions depend on this */
 	dn->components = talloc_zero_array(dn, struct ldb_dn_component, 3);
@@ -277,19 +279,109 @@ static bool ldb_dn_explode(struct ldb_dn *dn)
 	dn->comp_num = 0;
 
 	/* Components data space is allocated here once */
-	data = talloc_array(dn->components, char, strlen(dn->linearized) + 1);
+	data = talloc_array(dn->components, char, strlen(parse_dn) + 1);
 	if (!data) {
 		return false;
 	}
 
-	p = dn->linearized;
-	in_attr = true;
+	p = parse_dn;
+	in_extended = true;
+	in_ex_name = false;
+	in_ex_value = false;
 	trim = true;
 	t = NULL;
 	d = dt = data;
 
 	while (*p) {
+		if (in_extended) {
+
+			if (!in_ex_name && !in_ex_value) {
+
+				if (p[0] == '<') {
+					p++;
+					ex_name = d;
+					in_ex_name = true;
+					continue;
+				} else if (p[0] == '\0') {
+					p++;
+					continue;
+				} else {
+					in_extended = false;
+					in_attr = true;
+					dt = d;
+
+					continue;
+				}
+			}
+			
+			if (in_ex_name && *p == '=') {
+				*d++ = '\0';
+				p++;
+				ex_value = d;
+				in_ex_name = false;
+				in_ex_value = true;
+				continue;
+			}
+
+			if (in_ex_value && *p == '>') {
+				const struct ldb_dn_extended_syntax *extended_syntax;
+				struct ldb_val ex_val = {
+					.data = ex_value,
+					.length = d - ex_value
+				};
+					
+				*d++ = '\0';
+				p++;
+				in_ex_value = false;
+
+				/* Process name and ex_value */
+
+				dn->extended_components = talloc_realloc(dn,
+									 dn->extended_components,
+									 struct ldb_dn_extended_component,
+									 dn->extended_comp_num + 1);
+				if ( ! dn->extended_components) {
+					/* ouch ! */
+					goto failed;
+				}
+
+				extended_syntax = ldb_dn_extended_syntax_by_name(dn->ldb, ex_name);
+				if (!extended_syntax) {
+					/* We don't know about this type of extended DN */
+					goto failed;
+				}
+
+				dn->extended_components[dn->extended_comp_num].name = talloc_strdup(dn->extended_components, ex_name);
+				if (!dn->extended_components[dn->extended_comp_num].name) {
+					/* ouch */
+					goto failed;
+				}
+				ret = extended_syntax->read_fn(dn->ldb, dn->extended_components,
+							       &ex_val, &dn->extended_components[dn->extended_comp_num].value);
+				if (ret != LDB_SUCCESS) {
+					dn->invalid = true;
+					goto failed;
+				}
+
+				dn->extended_comp_num++;
 
+				if (*p == '\0') {
+					/* We have reached the end (extended component only)! */
+					talloc_free(data);
+					return true;
+
+				} else if (*p == ';') {
+					p++;
+					continue;
+				} else {
+					dn->invalid = true;
+					goto failed;
+				}
+			}
+
+			*d++ = *p++;
+			continue;
+		}
 		if (in_attr) {
 			if (trim) {
 				if (*p == ' ') {
@@ -315,6 +407,7 @@ static bool ldb_dn_explode(struct ldb_dn *dn)
 					goto failed;
 				}
 				
+				/* Copy this character across from parse_dn, now we have trimmed out spaces */
 				*d++ = *p++;
 				continue;
 			}
@@ -339,6 +432,7 @@ static bool ldb_dn_explode(struct ldb_dn *dn)
 				trim = true;
 				l = 0;
 
+				/* Terminate this string in d (which is a copy of parse_dn with spaces trimmed) */
 				*d++ = '\0';
 				dn->components[dn->comp_num].name = talloc_strdup(dn->components, dt);
 				if ( ! dn->components[dn->comp_num].name) {
@@ -614,6 +708,74 @@ const char *ldb_dn_get_linearized(struct ldb_dn *dn)
 	return dn->linearized;
 }
 
+char *ldb_dn_get_extended_linearized(void *mem_ctx, struct ldb_dn *dn, int mode)
+{
+	const char *linearized = ldb_dn_get_linearized(dn);
+	char *p;
+	int i;
+
+	if (!linearized) {
+		return NULL;
+	}
+
+	if (!ldb_dn_has_extended(dn)) {
+		return talloc_strdup(mem_ctx, linearized);
+	}
+	
+	if (!ldb_dn_validate(dn)) {
+		return NULL;
+	}
+
+	for (i=0; i < dn->extended_comp_num; i++) {
+		struct ldb_val val;
+		int ret;
+		const struct ldb_dn_extended_syntax *extended_syntax;
+		const char *name = dn->extended_components[i].name;
+		
+		extended_syntax = ldb_dn_extended_syntax_by_name(dn->ldb, name);
+
+		if (mode == 1) {
+			ret = extended_syntax->write_clear_fn(dn->ldb, mem_ctx,
+							      &dn->extended_components[i].value,
+							      &val);
+		} else if (mode == 0) {
+			ret = extended_syntax->write_hex_fn(dn->ldb, mem_ctx,
+							      &dn->extended_components[i].value,
+							      &val);
+		} else {
+			ret = -1;
+		}
+
+		if (ret != LDB_SUCCESS) {
+			return NULL;
+		}
+
+		if (i == 0) {
+			p = talloc_asprintf(mem_ctx, "<%s=%s>", dn->extended_components[i].name, val.data);
+		} else {
+			p = talloc_asprintf_append(p, ";<%s=%s>",  dn->extended_components[i].name, val.data);
+		}
+
+		talloc_free(val.data);
+
+		if (!p) {
+			return NULL;
+		}
+	}
+
+	if (dn->extended_comp_num && *linearized) {
+		p = talloc_asprintf_append(p, ";%s", linearized);
+	}
+
+	if (!p) {
+		return NULL;
+	}
+
+	return p;
+}
+
+
+
 char *ldb_dn_alloc_linearized(void *mem_ctx, struct ldb_dn *dn)
 {
 	return talloc_strdup(mem_ctx, ldb_dn_get_linearized(dn));
@@ -909,6 +1071,30 @@ static struct ldb_dn_component ldb_dn_copy_component(void *mem_ctx, struct ldb_d
 	return dst;
 }
 
+static struct ldb_dn_extended_component ldb_dn_extended_copy_component(void *mem_ctx, struct ldb_dn_extended_component *src)
+{
+	struct ldb_dn_extended_component dst;
+
+	memset(&dst, 0, sizeof(dst));
+
+	if (src == NULL) {
+		return dst;
+	}
+
+	dst.value = ldb_val_dup(mem_ctx, &(src->value));
+	if (dst.value.data == NULL) {
+		return dst;
+	}
+
+	dst.name = talloc_strdup(mem_ctx, src->name);
+	if (dst.name == NULL) {
+		LDB_FREE(dst.value.data);
+		return dst;
+	}
+
+	return dst;
+}
+
 struct ldb_dn *ldb_dn_copy(void *mem_ctx, struct ldb_dn *dn)
 {
 	struct ldb_dn *new_dn;
@@ -942,6 +1128,24 @@ struct ldb_dn *ldb_dn_copy(void *mem_ctx, struct ldb_dn *dn)
 		}
 	}
 
+	if (dn->extended_components) {
+		int i;
+
+		new_dn->extended_components = talloc_zero_array(new_dn, struct ldb_dn_extended_component, dn->extended_comp_num);
+		if ( ! new_dn->extended_components) {
+			talloc_free(new_dn);
+			return NULL;
+		}
+
+		for (i = 0; i < dn->extended_comp_num; i++) {
+			new_dn->extended_components[i] = ldb_dn_extended_copy_component(new_dn->extended_components, &dn->extended_components[i]);
+			if ( ! new_dn->extended_components[i].value.data) {
+				talloc_free(new_dn);
+				return NULL;
+			}
+		}
+	}
+
 	if (dn->casefold) {
 		new_dn->casefold = talloc_strdup(new_dn, dn->casefold);
 		if ( ! new_dn->casefold) {
@@ -958,6 +1162,14 @@ struct ldb_dn *ldb_dn_copy(void *mem_ctx, struct ldb_dn *dn)
 		}
 	}
 
+	if (dn->extended_linearized) {
+		new_dn->extended_linearized = talloc_strdup(new_dn, dn->extended_linearized);
+		if ( ! new_dn->extended_linearized) {
+			talloc_free(new_dn);
+			return NULL;
+		}
+	}
+
 	return new_dn;
 }
 
@@ -1037,6 +1249,13 @@ bool ldb_dn_add_base(struct ldb_dn *dn, struct ldb_dn *base)
 		dn->linearized = t;
 	}
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	if (dn->extended_linearized) {
+		LDB_FREE(dn->extended_linearized);
+	}
+
+	LDB_FREE(dn->extended_components);
+	dn->extended_comp_num = 0;
 	return true;
 }
 
@@ -1149,6 +1368,12 @@ bool ldb_dn_add_child(struct ldb_dn *dn, struct ldb_dn *child)
 		dn->linearized = t;
 	}
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	LDB_FREE(dn->extended_linearized);
+
+	LDB_FREE(dn->extended_components);
+	dn->extended_comp_num = 0;
+
 	return true;
 }
 
@@ -1218,6 +1443,12 @@ bool ldb_dn_remove_base_components(struct ldb_dn *dn, unsigned int num)
 	LDB_FREE(dn->casefold);
 	LDB_FREE(dn->linearized);
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	LDB_FREE(dn->extended_linearized);
+
+	LDB_FREE(dn->extended_components);
+	dn->extended_comp_num = 0;
+
 	return true;
 }
 
@@ -1256,6 +1487,11 @@ bool ldb_dn_remove_child_components(struct ldb_dn *dn, unsigned int num)
 	LDB_FREE(dn->casefold);
 	LDB_FREE(dn->linearized);
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	LDB_FREE(dn->extended_linearized);
+
+	LDB_FREE(dn->extended_components);
+	dn->extended_comp_num = 0;
 	return true;
 }
 
@@ -1273,6 +1509,11 @@ struct ldb_dn *ldb_dn_get_parent(void *mem_ctx, struct ldb_dn *dn)
 		return NULL;
 	}
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	LDB_FREE(dn->extended_linearized);
+
+	LDB_FREE(dn->extended_components);
+	dn->extended_comp_num = 0;
 	return new_dn;
 }
 
@@ -1434,9 +1675,97 @@ int ldb_dn_set_component(struct ldb_dn *dn, int num, const char *name, const str
 	LDB_FREE(dn->casefold);
 	LDB_FREE(dn->linearized);
 
+	/* Wipe the extended_linearized DN, as the GUID and SID are almost certainly no longer valid */
+	LDB_FREE(dn->extended_linearized);
+
+	dn->extended_comp_num = 0;
+	LDB_FREE(dn->extended_components);
 	return LDB_SUCCESS;
 }
 
+const struct ldb_val *ldb_dn_get_extended_component(struct ldb_dn *dn, const char *name)
+{
+	int i;
+	if ( ! ldb_dn_validate(dn)) {
+		return NULL;
+	}
+	for (i=0; i < dn->extended_comp_num; i++) {
+		if (ldb_attr_cmp(dn->extended_components[i].name, name) == 0) {
+			return &dn->extended_components[i].value;
+		}
+	}
+	return NULL;
+}
+
+int ldb_dn_set_extended_component(struct ldb_dn *dn, const char *name, const struct ldb_val *val)
+{
+	struct ldb_dn_extended_component *p;
+	int i;
+				
+	if ( ! ldb_dn_validate(dn)) {
+		return LDB_ERR_OTHER;
+	}
+
+	for (i=0; i < dn->extended_comp_num; i++) {
+		if (ldb_attr_cmp(dn->extended_components[i].name, name) == 0) {
+			if (val) {
+				dn->extended_components[i].value = ldb_val_dup(dn->extended_components, val);
+
+				dn->extended_components[i].name = talloc_strdup(dn->extended_components, name);
+				if (!dn->extended_components[i].name || !dn->extended_components[i].value.data) {
+					dn->invalid = true;
+					return LDB_ERR_OPERATIONS_ERROR;
+				}
+	
+			} else {
+				if (i != (dn->extended_comp_num - 1)) {
+					memmove(&dn->extended_components[i], &dn->extended_components[i+1],
+						((dn->extended_comp_num-1) - i)*sizeof(*dn->extended_components));
+				}
+				dn->extended_comp_num--;
+				
+				dn->extended_components = talloc_realloc(dn,
+						   dn->extended_components,
+						   struct ldb_dn_extended_component,
+						   dn->extended_comp_num);
+				if (!dn->extended_components) {
+					dn->invalid = true;
+					return LDB_ERR_OPERATIONS_ERROR;
+				}
+				return 0;
+			}
+		}
+	}
+
+	p = dn->extended_components
+		= talloc_realloc(dn,
+				 dn->extended_components,
+				 struct ldb_dn_extended_component,
+				 dn->extended_comp_num + 1);
+	if (!dn->extended_components) {
+		dn->invalid = true;
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	
+	p[dn->extended_comp_num].value = ldb_val_dup(dn->extended_components, val);
+	p[dn->extended_comp_num].name = talloc_strdup(p, name);
+	
+	if (!dn->extended_components[i].name || !dn->extended_components[i].value.data) {
+		dn->invalid = true;
+		return LDB_ERR_OPERATIONS_ERROR;
+	}
+	dn->extended_components = p;
+	dn->extended_comp_num++;
+	
+	return 0;
+}
+
+void ldb_dn_remove_extended_components(struct ldb_dn *dn)
+{
+	dn->extended_comp_num = 0;
+	LDB_FREE(dn->extended_components);	
+}
+
 bool ldb_dn_is_valid(struct ldb_dn *dn)
 {
 	if ( ! dn) return false;
@@ -1449,6 +1778,13 @@ bool ldb_dn_is_special(struct ldb_dn *dn)
 	return dn->special;
 }
 
+bool ldb_dn_has_extended(struct ldb_dn *dn)
+{
+	if ( ! dn || dn->invalid) return false;
+	if (dn->extended_linearized && (dn->extended_linearized[0] == '<')) return true;
+	return dn->extended_comp_num != 0;
+}
+
 bool ldb_dn_check_special(struct ldb_dn *dn, const char *check)
 {
 	if ( ! dn || dn->invalid) return false;
@@ -1458,6 +1794,7 @@ bool ldb_dn_check_special(struct ldb_dn *dn, const char *check)
 bool ldb_dn_is_null(struct ldb_dn *dn)
 {
 	if ( ! dn || dn->invalid) return false;
+	if (ldb_dn_has_extended(dn)) return false;
 	if (dn->linearized && (dn->linearized[0] == '\0')) return true;
 	return false;
 }