s4-messaging: fixed the removal of messaging sockets in child tasks

when a child task exits we were firing a destructor on any inherited
messaging contexts, which could trigger a removal of the parents
message socket and messaging database entry.

This adds a new auto_remove flag to imessaging_init(), and exposes the
cleanup code for use by the stream service.

Pair-Programmed-With: Andrew Bartlett <abartlet@samba.org>

Autobuild-User: Andrew Tridgell <tridge@samba.org>
Autobuild-Date: Fri Jul 22 08:09:06 CEST 2011 on sn-devel-104

diff --git a/source4/lib/messaging/messaging.c b/source4/lib/messaging/messaging.c
index 484f22b2ee2a43312214fa80565ed385656c18a6..ccc60032a6a0626dbfad5f98dee2a029f5bd633d 100644 (file)
--- a/source4/lib/messaging/messaging.c
+++ b/source4/lib/messaging/messaging.c
@@ -541,10 +541,11 @@ NTSTATUS imessaging_send_ptr(struct imessaging_context *msg, struct server_id se
 
 
 /*
-  destroy the messaging context
+  remove our messaging socket and database entry
 */
-static int imessaging_destructor(struct imessaging_context *msg)
+int imessaging_cleanup(struct imessaging_context *msg)
 {
+       DEBUG(5,("imessaging: cleaning up %s\n", msg->path));
        unlink(msg->path);
        while (msg->names && msg->names[0]) {
                irpc_remove_name(msg, msg->names[0]);
@@ -554,11 +555,17 @@ static int imessaging_destructor(struct imessaging_context *msg)
 
 /*
   create the listening socket and setup the dispatcher
+
+  use temporary=true when you want a destructor to remove the
+  associated messaging socket and database entry on talloc free. Don't
+  use this in processes that may fork and a child may talloc free this
+  memory
 */
 struct imessaging_context *imessaging_init(TALLOC_CTX *mem_ctx,
-                                        const char *dir,
-                                        struct server_id server_id, 
-                                        struct tevent_context *ev)
+                                          const char *dir,
+                                          struct server_id server_id,
+                                          struct tevent_context *ev,
+                                          bool auto_remove)
 {
        struct imessaging_context *msg;
        NTSTATUS status;
@@ -622,7 +629,9 @@ struct imessaging_context *imessaging_init(TALLOC_CTX *mem_ctx,
                                       EVENT_FD_READ, imessaging_handler, msg);
        tevent_fd_set_auto_close(msg->event.fde);
 
-       talloc_set_destructor(msg, imessaging_destructor);
+       if (auto_remove) {
+               talloc_set_destructor(msg, imessaging_cleanup);
+       }
        
        imessaging_register(msg, NULL, MSG_PING, ping_message);
        imessaging_register(msg, NULL, MSG_IRPC, irpc_handler);
@@ -641,7 +650,7 @@ struct imessaging_context *imessaging_client_init(TALLOC_CTX *mem_ctx,
        struct server_id id;
        ZERO_STRUCT(id);
        id.pid = random() % 0x10000000;
-       return imessaging_init(mem_ctx, dir, id, ev);
+       return imessaging_init(mem_ctx, dir, id, ev, true);
 }
 /*
   a list of registered irpc server functions

diff --git a/source4/lib/messaging/messaging.h b/source4/lib/messaging/messaging.h
index eb8a8abc79553fc16d16a213267a95bc547308b2..e51590fe74a327794be05783c2eb533ee4cf94e1 100644 (file)
--- a/source4/lib/messaging/messaging.h
+++ b/source4/lib/messaging/messaging.h
@@ -54,9 +54,11 @@ NTSTATUS imessaging_register(struct imessaging_context *msg, void *private_data,
 NTSTATUS imessaging_register_tmp(struct imessaging_context *msg, void *private_data,
                                msg_callback_t fn, uint32_t *msg_type);
 struct imessaging_context *imessaging_init(TALLOC_CTX *mem_ctx,
-                                        const char *dir,
-                                        struct server_id server_id,
-                                        struct tevent_context *ev);
+                                          const char *dir,
+                                          struct server_id server_id,
+                                          struct tevent_context *ev,
+                                          bool auto_remove);
+int imessaging_cleanup(struct imessaging_context *msg);
 struct imessaging_context *imessaging_client_init(TALLOC_CTX *mem_ctx,
                                         const char *dir,
                                         struct tevent_context *ev);

diff --git a/source4/lib/messaging/pymessaging.c b/source4/lib/messaging/pymessaging.c
index cafd45beae33804e39fa4d6a122e9cb411d94987..4f90db59f2db7bac565b8c48ca65a21a9e4358d5 100644 (file)
--- a/source4/lib/messaging/pymessaging.c
+++ b/source4/lib/messaging/pymessaging.c
@@ -96,13 +96,13 @@ static PyObject *py_imessaging_connect(PyTypeObject *self, PyObject *args, PyObj
                        return NULL;
 
                ret->msg_ctx = imessaging_init(ret->mem_ctx,
-                                           imessaging_path,
-                                           server_id,
-                                           ev);
+                                              imessaging_path,
+                                              server_id,
+                                              ev, true);
        } else {
                ret->msg_ctx = imessaging_client_init(ret->mem_ctx,
-                                           imessaging_path,
-                                           ev);
+                                                     imessaging_path,
+                                                     ev);
        }
 
        if (ret->msg_ctx == NULL) {

diff --git a/source4/lib/messaging/tests/irpc.c b/source4/lib/messaging/tests/irpc.c
index cfa2bcb91e1e282513b5a613b56b5004a93a9031..554a7efa99732afef7544e33b25f9b859ec899d7 100644 (file)
--- a/source4/lib/messaging/tests/irpc.c
+++ b/source4/lib/messaging/tests/irpc.c
@@ -249,14 +249,14 @@ static bool irpc_setup(struct torture_context *tctx, void **_data)
                       imessaging_init(tctx,
                                      lpcfg_imessaging_path(tctx, tctx->lp_ctx),
                                      cluster_id(0, MSG_ID1),
-                                     data->ev),
+                                     data->ev, true),
                       "Failed to init first messaging context");
 
        torture_assert(tctx, data->msg_ctx2 = 
                       imessaging_init(tctx,
                                      lpcfg_imessaging_path(tctx, tctx->lp_ctx),
                                      cluster_id(0, MSG_ID2), 
-                                     data->ev),
+                                     data->ev, true),
                       "Failed to init second messaging context");
 
        /* register the server side function */

diff --git a/source4/lib/messaging/tests/messaging.c b/source4/lib/messaging/tests/messaging.c
index 38c34fc52ee328c98de9b626e67b6a8fd0643637..c5d37953d05c5fd23f6c0d7eac4216bbb2b9c434 100644 (file)
--- a/source4/lib/messaging/tests/messaging.c
+++ b/source4/lib/messaging/tests/messaging.c
@@ -72,8 +72,8 @@ static bool test_ping_speed(struct torture_context *tctx)
        ev = tctx->ev;
 
        msg_server_ctx = imessaging_init(tctx,
-                                       lpcfg_imessaging_path(tctx, tctx->lp_ctx), cluster_id(0, 1),
-                                       ev);
+                                        lpcfg_imessaging_path(tctx, tctx->lp_ctx), cluster_id(0, 1),
+                                        ev, true);
        
        torture_assert(tctx, msg_server_ctx != NULL, "Failed to init ping messaging context");
                
@@ -81,9 +81,9 @@ static bool test_ping_speed(struct torture_context *tctx)
        imessaging_register_tmp(msg_server_ctx, tctx, exit_message, &msg_exit);
 
        msg_client_ctx = imessaging_init(tctx,
-                                       lpcfg_imessaging_path(tctx, tctx->lp_ctx),
-                                       cluster_id(0, 2), 
-                                       ev);
+                                        lpcfg_imessaging_path(tctx, tctx->lp_ctx),
+                                        cluster_id(0, 2),
+                                        ev, true);
 
        torture_assert(tctx, msg_client_ctx != NULL, 
                       "msg_client_ctx imessaging_init() failed");

diff --git a/source4/smbd/server.c b/source4/smbd/server.c
index b0f683ba93f7ed718d18df5a01756736c8da5db2..ba8f8227a931db7e775879c9739492b2c6c2a713 100644 (file)
--- a/source4/smbd/server.c
+++ b/source4/smbd/server.c
@@ -220,8 +220,8 @@ static NTSTATUS setup_parent_messaging(struct tevent_context *event_ctx,
        NTSTATUS status;
 
        msg = imessaging_init(talloc_autofree_context(),
-                            lpcfg_imessaging_path(event_ctx, lp_ctx),
-                            cluster_id(0, SAMBA_PARENT_TASKID), event_ctx);
+                             lpcfg_imessaging_path(event_ctx, lp_ctx),
+                             cluster_id(0, SAMBA_PARENT_TASKID), event_ctx, false);
        NT_STATUS_HAVE_NO_MEMORY(msg);
 
        irpc_add_name(msg, "samba");

diff --git a/source4/smbd/service_stream.c b/source4/smbd/service_stream.c
index 6e65122063b253cd275eb3576955801b409237c6..28159f4f00d0021100180550aa345765fba135e1 100644 (file)
--- a/source4/smbd/service_stream.c
+++ b/source4/smbd/service_stream.c
@@ -77,6 +77,7 @@ void stream_terminate_connection(struct stream_connection *srv_conn, const char
 
        talloc_free(srv_conn->event.fde);
        srv_conn->event.fde = NULL;
+       imessaging_cleanup(srv_conn->msg_ctx);
        model_ops->terminate(event_ctx, srv_conn->lp_ctx, reason);
        talloc_free(srv_conn);
 }
@@ -188,8 +189,8 @@ static void stream_new_connection(struct tevent_context *ev,
 
        /* setup to receive internal messages on this connection */
        srv_conn->msg_ctx = imessaging_init(srv_conn,
-                                          lpcfg_imessaging_path(srv_conn, lp_ctx),
-                                          srv_conn->server_id, ev);
+                                           lpcfg_imessaging_path(srv_conn, lp_ctx),
+                                           srv_conn->server_id, ev, false);
        if (!srv_conn->msg_ctx) {
                stream_terminate_connection(srv_conn, "imessaging_init() failed");
                return;

diff --git a/source4/smbd/service_task.c b/source4/smbd/service_task.c
index 32c44cf6603fc688037ccd8dcdf846376e2dfdda..f68805fde032a5147a6868fbcc803c19cf9a1421 100644 (file)
--- a/source4/smbd/service_task.c
+++ b/source4/smbd/service_task.c
@@ -79,9 +79,9 @@ static void task_server_callback(struct tevent_context *event_ctx,
        task->lp_ctx = lp_ctx;
 
        task->msg_ctx = imessaging_init(task,
-                                      lpcfg_imessaging_path(task, task->lp_ctx),
-                                      task->server_id, 
-                                      task->event_ctx);
+                                       lpcfg_imessaging_path(task, task->lp_ctx),
+                                       task->server_id,
+                                       task->event_ctx, false);
        if (!task->msg_ctx) {
                task_server_terminate(task, "imessaging_init() failed", true);
                return;