r514: added a context pointer to the samdb interface, as suggested by

metze. Also added a reference count so that a client can close the
connection handle and still used a derived domain handle.
(This used to be commit b1cd98188d6f1f8236f5dbc7a3605a39ae27fb73)

2 files changed, 138 insertions, 43 deletions

diff --git a/source4/rpc_server/samr/dcesrv_samr.c b/source4/rpc_server/samr/dcesrv_samr.c
index af716e5cef..0b443a7078 100644
--- a/source4/rpc_server/samr/dcesrv_samr.c
+++ b/source4/rpc_server/samr/dcesrv_samr.c
@@ -39,6 +39,8 @@ enum samr_handle {
   state asscoiated with a samr_Connect*() operation
 */
 struct samr_connect_state {
+	int reference_count;
+	void *sam_ctx;
 	TALLOC_CTX *mem_ctx;
 	uint32 access_mask;
 };
@@ -47,6 +49,9 @@ struct samr_connect_state {
   state associated with a samr_OpenDomain() operation
 */
 struct samr_domain_state {
+	struct samr_connect_state *connect_state;
+	int reference_count;
+	void *sam_ctx;
 	TALLOC_CTX *mem_ctx;
 	uint32 access_mask;
 	const char *domain_sid;
@@ -57,6 +62,8 @@ struct samr_domain_state {
   state associated with a open user handle
 */
 struct samr_user_state {
+	struct samr_domain_state *domain_state;
+	void *sam_ctx;
 	TALLOC_CTX *mem_ctx;
 	uint32 access_mask;
 	const char *user_sid;
@@ -65,12 +72,24 @@ struct samr_user_state {
 
 
 /*
+  destroy connection state
+*/
+static void samr_Connect_close(struct samr_connect_state *state)
+{
+	state->reference_count--;
+	if (state->reference_count == 0) {
+		samdb_close(state->sam_ctx);
+		talloc_destroy(state->mem_ctx);
+	}
+}
+
+/*
   destroy an open connection. This closes the database connection
 */
 static void samr_Connect_destroy(struct dcesrv_connection *conn, struct dcesrv_handle *h)
 {
 	struct samr_connect_state *state = h->data;
-	talloc_destroy(state->mem_ctx);
+	samr_Connect_close(state);
 }
 
 /* 
@@ -99,7 +118,8 @@ static NTSTATUS samr_Connect(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem
 	state->mem_ctx = connect_mem_ctx;
 
 	/* make sure the sam database is accessible */
-	if (samdb_connect() != 0) {
+	state->sam_ctx = samdb_connect();
+	if (state->sam_ctx == NULL) {
 		talloc_destroy(state->mem_ctx);
 		return NT_STATUS_INVALID_SYSTEM_SERVICE;
 	}
@@ -113,6 +133,7 @@ static NTSTATUS samr_Connect(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem
 	handle->data = state;
 	handle->destroy = samr_Connect_destroy;
 
+	state->reference_count = 1;
 	state->access_mask = r->in.access_mask;
 	*r->out.handle = handle->wire_handle;
 
@@ -183,6 +204,7 @@ static NTSTATUS samr_Shutdown(struct dcesrv_call_state *dce_call, TALLOC_CTX *me
 static NTSTATUS samr_LookupDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
 				  struct samr_LookupDomain *r)
 {
+	struct samr_connect_state *state;
 	struct dcesrv_handle *h;
 	struct dom_sid2 *sid;
 	const char *sidstr;
@@ -191,13 +213,16 @@ static NTSTATUS samr_LookupDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX
 
 	DCESRV_CHECK_HANDLE(h);
 
+	state = h->data;
+
 	r->out.sid = NULL;
 
 	if (r->in.domain->name == NULL) {
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 
-	sidstr = samdb_search_string(mem_ctx, "objectSid",
+	sidstr = samdb_search_string(state->sam_ctx,
+				     mem_ctx, "objectSid",
 				     "(&(name=%s)(objectclass=domain))",
 				     r->in.domain->name);
 	if (sidstr == NULL) {
@@ -225,6 +250,7 @@ static NTSTATUS samr_LookupDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX
 static NTSTATUS samr_EnumDomains(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
 				 struct samr_EnumDomains *r)
 {
+	struct samr_connect_state *state;
 	struct dcesrv_handle *h;
 	struct samr_SamArray *array;
 	char **domains;
@@ -234,11 +260,14 @@ static NTSTATUS samr_EnumDomains(struct dcesrv_call_state *dce_call, TALLOC_CTX
 
 	DCESRV_CHECK_HANDLE(h);
 
+	state = h->data;
+
 	*r->out.resume_handle = 0;
 	r->out.sam = NULL;
 	r->out.num_entries = 0;
 
-	count = samdb_search_string_multiple(mem_ctx, &domains, 
+	count = samdb_search_string_multiple(state->sam_ctx,
+					     mem_ctx, &domains, 
 					     "name", "(objectclass=domain)");
 	if (count == -1) {
 		DEBUG(1,("samdb: no domains found in EnumDomains\n"));
@@ -286,7 +315,11 @@ static NTSTATUS samr_EnumDomains(struct dcesrv_call_state *dce_call, TALLOC_CTX
 static void samr_Domain_destroy(struct dcesrv_connection *conn, struct dcesrv_handle *h)
 {
 	struct samr_domain_state *state = h->data;
-	talloc_destroy(state->mem_ctx);
+	state->reference_count--;
+	if (state->reference_count == 0) {
+		samr_Connect_close(state->connect_state);
+		talloc_destroy(state->mem_ctx);
+	}
 }
 
 /* 
@@ -297,18 +330,22 @@ static NTSTATUS samr_OpenDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX *
 {
 	struct dcesrv_handle *h_conn, *h_domain;
 	char *sidstr, *domain_name;
+	struct samr_connect_state *c_state;
 	struct samr_domain_state *state;
 	TALLOC_CTX *mem_ctx2;
 
 	h_conn = dcesrv_handle_fetch(dce_call->conn, r->in.handle, SAMR_HANDLE_CONNECT);
 	DCESRV_CHECK_HANDLE(h_conn);
 
+	c_state = h_conn->data;
+
 	sidstr = dom_sid_string(mem_ctx, r->in.sid);
 	if (sidstr == NULL) {
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 
-	domain_name = samdb_search_string(mem_ctx, "name",
+	domain_name = samdb_search_string(c_state->sam_ctx,
+					  mem_ctx, "name",
 					  "(&(objectSid=%s)(objectclass=domain))", 
 					  sidstr);
 	if (domain_name == NULL) {
@@ -326,6 +363,9 @@ static NTSTATUS samr_OpenDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX *
 		return NT_STATUS_NO_MEMORY;
 	}
 
+	state->reference_count = 1;
+	state->connect_state = c_state;
+	state->sam_ctx = c_state->sam_ctx;
 	state->mem_ctx = mem_ctx2;
 	state->domain_sid = talloc_steal(mem_ctx, mem_ctx2, sidstr);
 	state->domain_name = talloc_steal(mem_ctx, mem_ctx2, domain_name);
@@ -337,6 +377,7 @@ static NTSTATUS samr_OpenDomain(struct dcesrv_call_state *dce_call, TALLOC_CTX *
 		return NT_STATUS_NO_MEMORY;
 	}
 
+	c_state->reference_count++;
 	h_domain->data = state;
 	h_domain->destroy = samr_Domain_destroy;
 	*r->out.domain_handle = h_domain->wire_handle;
@@ -391,13 +432,29 @@ static NTSTATUS samr_EnumDomainGroups(struct dcesrv_call_state *dce_call, TALLOC
 static NTSTATUS samr_CreateUser2(struct dcesrv_call_state *dce_call, TALLOC_CTX *mem_ctx,
 				 struct samr_CreateUser2 *r)
 {
+	struct samr_domain_state *d_state;
 	struct samr_user_state *state;
 	struct dcesrv_handle *h = dcesrv_handle_fetch(dce_call->conn, 
 						      r->in.handle, 
 						      SAMR_HANDLE_DOMAIN);
+	const char *name;
+
 	DCESRV_CHECK_HANDLE(h);
 
+	d_state = h->data;
+
+	if (r->in.username->name == NULL) {
+		return NT_STATUS_INVALID_PARAMETER;
+	}
+
 	/* check if the user already exists */
+	name = samdb_search_string(d_state->sam_ctx, mem_ctx, "name",
+				   "(&(name=%s)(objectclass=user))",
+				   r->in.username->name);
+	if (name != NULL) {
+		return NT_STATUS_USER_EXISTS;
+	}
+
 	/* read the default user template */
 	/* allocate a rid */
 	/* create a ldb_message for the user */
@@ -863,27 +920,37 @@ static NTSTATUS samr_GetDomPwInfo(struct dcesrv_call_state *dce_call, TALLOC_CTX
 	struct ldb_message **msgs;
 	int ret;
 	char * const attrs[] = {"minPwdLength", "pwdProperties", NULL };
+	void *sam_ctx;
 
 	if (r->in.name == NULL || r->in.name->name == NULL) {
 		return NT_STATUS_NO_SUCH_DOMAIN;
 	}
 
-	ret = samdb_search(mem_ctx, &msgs, attrs, 
+	sam_ctx = samdb_connect();
+	if (sam_ctx == NULL) {
+		return NT_STATUS_INVALID_SYSTEM_SERVICE;
+	}
+
+	ret = samdb_search(sam_ctx, 
+			   mem_ctx, &msgs, attrs, 
 			   "(&(name=%s)(objectclass=domain))",
 			   r->in.name->name);
 	if (ret <= 0) {
+		samdb_close(sam_ctx);
 		return NT_STATUS_NO_SUCH_DOMAIN;
 	}
 	if (ret > 1) {
-		samdb_search_free(mem_ctx, msgs);
+		samdb_search_free(sam_ctx, mem_ctx, msgs);
+		samdb_close(sam_ctx);
 		return NT_STATUS_INTERNAL_DB_CORRUPTION;
 	}
 
 	r->out.info.min_pwd_len         = samdb_result_uint(msgs[0], "minPwdLength", 0);
 	r->out.info.password_properties = samdb_result_uint(msgs[0], "pwdProperties", 1);
 
-	samdb_search_free(mem_ctx, msgs);
+	samdb_search_free(sam_ctx, mem_ctx, msgs);
 
+	samdb_close(sam_ctx);
 	return NT_STATUS_OK;
 }
 
diff --git a/source4/rpc_server/samr/samdb.c b/source4/rpc_server/samr/samdb.c
index c0e0d12a7b..d384c6ada7 100644
--- a/source4/rpc_server/samr/samdb.c
+++ b/source4/rpc_server/samr/samdb.c
@@ -22,15 +22,10 @@
 
 #include "includes.h"
 
+struct samdb_context {
+	struct ldb_context *ldb;
+};
 
-/*
-  the way that unix fcntl locking works forces us to have a static ldb
-  handle here rather than a much more sensible approach of having the
-  ldb handle as part of the samr_Connect() pipe state. Otherwise we
-  would try to open the ldb more than once, and tdb would rightly
-  refuse the second open due to the broken nature of unix locking.
-*/
-static struct ldb_context *sam_db;
 
 /*
   this is used to catch debug messages from ldb
@@ -49,22 +44,48 @@ void samdb_debug(void *context, enum ldb_debug_level level, const char *fmt, va_
 
 /*
   connect to the SAM database
-  return 0 on success, -1 on failure
+  return an opaque context pointer on success, or NULL on failure
  */
-int samdb_connect(void)
+void *samdb_connect(void)
 {
-	if (sam_db != NULL) {
-		return 0;
+	struct samdb_context *ctx;
+	/*
+	  the way that unix fcntl locking works forces us to have a
+	  static ldb handle here rather than a much more sensible
+	  approach of having the ldb handle as part of the
+	  samr_Connect() pipe state. Otherwise we would try to open
+	  the ldb more than once, and tdb would rightly refuse the
+	  second open due to the broken nature of unix locking.
+	*/
+	static struct ldb_context *static_sam_db;
+
+	if (static_sam_db == NULL) {
+		static_sam_db = ldb_connect(lp_sam_url(), 0, NULL);
+		if (static_sam_db == NULL) {
+			return NULL;
+		}
 	}
-	sam_db = ldb_connect(lp_sam_url(), 0, NULL);
 
-	if (sam_db == NULL) {
-		return -1;
+	ldb_set_debug(static_sam_db, samdb_debug, NULL);
+
+	ctx = malloc_p(struct samdb_context);
+	if (!ctx) {
+		errno = ENOMEM;
+		return NULL;
 	}
 
-	ldb_set_debug(sam_db, samdb_debug, NULL);
+	ctx->ldb = static_sam_db;
+
+	return ctx;
+}
 
-	return 0;
+/* close a connection to the sam */
+void samdb_close(void *ctx)
+{
+	struct samdb_context *sam_ctx = ctx;
+	/* we don't actually close due to broken posix locking semantics */
+	sam_ctx->ldb = NULL;
+	free(sam_ctx);
 }
 
 /*
@@ -78,12 +99,14 @@ static void *samdb_alloc(void *context, void *ptr, size_t size)
 /*
   search the sam for the specified attributes - va_list varient
 */
-int samdb_search_v(TALLOC_CTX *mem_ctx,
+int samdb_search_v(void *ctx, 
+		   TALLOC_CTX *mem_ctx,
 		   struct ldb_message ***res,
 		   char * const *attrs,
 		   const char *format, 
 		   va_list ap)
 {
+	struct samdb_context *sam_ctx = ctx;
 	char *expr = NULL;
 	int count;
 
@@ -92,9 +115,9 @@ int samdb_search_v(TALLOC_CTX *mem_ctx,
 		return -1;
 	}
 
-	ldb_set_alloc(sam_db, samdb_alloc, mem_ctx);
+	ldb_set_alloc(sam_ctx->ldb, samdb_alloc, mem_ctx);
 
-	count = ldb_search(sam_db, NULL, LDB_SCOPE_SUBTREE, expr, attrs, res);
+	count = ldb_search(sam_ctx->ldb, NULL, LDB_SCOPE_SUBTREE, expr, attrs, res);
 
 	free(expr);
 
@@ -105,7 +128,8 @@ int samdb_search_v(TALLOC_CTX *mem_ctx,
 /*
   search the sam for the specified attributes - varargs varient
 */
-int samdb_search(TALLOC_CTX *mem_ctx, 
+int samdb_search(void *ctx,
+		 TALLOC_CTX *mem_ctx, 
 		 struct ldb_message ***res,
 		 char * const *attrs,
 		 const char *format, ...)
@@ -114,7 +138,7 @@ int samdb_search(TALLOC_CTX *mem_ctx,
 	int count;
 
 	va_start(ap, format);
-	count = samdb_search_v(mem_ctx, res, attrs, format, ap);
+	count = samdb_search_v(ctx, mem_ctx, res, attrs, format, ap);
 	va_end(ap);
 
 	return count;
@@ -123,17 +147,20 @@ int samdb_search(TALLOC_CTX *mem_ctx,
 /*
   free up a search result
 */
-int samdb_search_free(TALLOC_CTX *mem_ctx, struct ldb_message **res)
+int samdb_search_free(void *ctx,
+		      TALLOC_CTX *mem_ctx, struct ldb_message **res)
 {
-	ldb_set_alloc(sam_db, samdb_alloc, mem_ctx);
-	return ldb_search_free(sam_db, res);
+	struct samdb_context *sam_ctx = ctx;
+	ldb_set_alloc(sam_ctx->ldb, samdb_alloc, mem_ctx);
+	return ldb_search_free(sam_ctx->ldb, res);
 }
 				 
 
 /*
   search the sam for a single string attribute in exactly 1 record
 */
-char *samdb_search_string(TALLOC_CTX *mem_ctx,
+char *samdb_search_string(void *ctx,
+			  TALLOC_CTX *mem_ctx,
 			  const char *attr_name,
 			  const char *format, ...)
 {
@@ -144,7 +171,7 @@ char *samdb_search_string(TALLOC_CTX *mem_ctx,
 	char *str = NULL;
 
 	va_start(ap, format);
-	count = samdb_search_v(mem_ctx, &res, attrs, format, ap);
+	count = samdb_search_v(ctx, mem_ctx, &res, attrs, format, ap);
 	va_end(ap);
 
 	if (count == 0) {
@@ -158,7 +185,7 @@ char *samdb_search_string(TALLOC_CTX *mem_ctx,
 	    res[0]->elements[0].values[0].data == NULL) {
 		DEBUG(1,("samdb: search for %s %s not single valued\n", 
 			 attr_name, format));
-		samdb_search_free(mem_ctx, res);
+		samdb_search_free(ctx, mem_ctx, res);
 		return NULL;
 	}
 
@@ -166,7 +193,7 @@ char *samdb_search_string(TALLOC_CTX *mem_ctx,
 			     res[0]->elements[0].values[0].data,
 			     res[0]->elements[0].values[0].length);
 
-	samdb_search_free(mem_ctx, res);
+	samdb_search_free(ctx, mem_ctx, res);
 
 	return str;
 }
@@ -176,7 +203,8 @@ char *samdb_search_string(TALLOC_CTX *mem_ctx,
   search the sam for multipe records each giving a single string attribute
   return the number of matches, or -1 on error
 */
-int samdb_search_string_multiple(TALLOC_CTX *mem_ctx,
+int samdb_search_string_multiple(void *ctx,
+				 TALLOC_CTX *mem_ctx,
 				 char ***strs,
 				 const char *attr_name,
 				 const char *format, ...)
@@ -187,7 +215,7 @@ int samdb_search_string_multiple(TALLOC_CTX *mem_ctx,
 	struct ldb_message **res = NULL;
 
 	va_start(ap, format);
-	count = samdb_search_v(mem_ctx, &res, attrs, format, ap);
+	count = samdb_search_v(ctx, mem_ctx, &res, attrs, format, ap);
 	va_end(ap);
 
 	if (count <= 0) {
@@ -201,14 +229,14 @@ int samdb_search_string_multiple(TALLOC_CTX *mem_ctx,
 		    res[i]->elements[0].values[0].data == NULL) {
 			DEBUG(1,("samdb: search for %s %s not single valued\n", 
 				 attr_name, format));
-			samdb_search_free(mem_ctx, res);
+			samdb_search_free(ctx, mem_ctx, res);
 			return -1;
 		}
 	}
 
 	*strs = talloc_array_p(mem_ctx, char *, count+1);
 	if (! *strs) {
-		samdb_search_free(mem_ctx, res);
+		samdb_search_free(ctx, mem_ctx, res);
 		return -1;
 	}
 
@@ -219,7 +247,7 @@ int samdb_search_string_multiple(TALLOC_CTX *mem_ctx,
 	}
 	(*strs)[count] = NULL;
 
-	samdb_search_free(mem_ctx, res);
+	samdb_search_free(ctx, mem_ctx, res);
 
 	return count;
 }