Add user control of the permissions that are set on the shared mem files

Signed-off-by: Angus Salkeld <asalkeld@redhat.com>

include/qb/qbipcs.h

@@ -117,6 +117,8 @@ struct qb_ipcs_poll_handlers {
  * The type of checks you should do are authentication, service availabilty
  * or process resource constraints.
  * @return 0 to accept or -errno to indicate a failure (sent back to the client)
+ *
+ * @note you can call qb_ipcs_connection_auth_set() within this function.
  */
 typedef int32_t (*qb_ipcs_connection_accept_fn) (qb_ipcs_connection_t *c,
 						 uid_t uid, gid_t gid);
@@ -377,6 +379,23 @@ qb_ipcs_connection_t * qb_ipcs_connection_first_get(qb_ipcs_service_t* pt);
 qb_ipcs_connection_t * qb_ipcs_connection_next_get(qb_ipcs_service_t* pt,
 						   qb_ipcs_connection_t *current);
 
+/**
+ * Set the permissions on and shared memory files so that both processes can
+ * read and write to them.
+ *
+ * @param conn connection instance
+ * @param uid the user id to set.
+ * @param gid the group id to set.
+ * @param mode the mode to set.
+ *
+ * @see chmod() chown()
+ * @note this must be called within the qb_ipcs_connection_accept_fn()
+ * callback.
+ */
+void qb_ipcs_connection_auth_set(qb_ipcs_connection_t *conn, uid_t uid,
+				 gid_t gid, mode_t mode);
+
+
 /* *INDENT-OFF* */
 #ifdef __cplusplus
 }

include/qb/qbrb.h

@@ -285,6 +285,14 @@ qb_ringbuffer_t *qb_rb_create_from_file(int32_t fd, uint32_t flags);
  */
 int32_t qb_rb_chown(qb_ringbuffer_t * rb, uid_t owner, gid_t group);
 
+/**
+ * Like 'chmod' it changes the mode of the ringbuffers resources.
+ * @param mode mode to change to
+ * @param rb ringbuffer instance
+ * @retval 0 == ok
+ * @retval -errno for error
+ */
+int32_t qb_rb_chmod(qb_ringbuffer_t * rb, mode_t mode);
 
 /* *INDENT-OFF* */
 #ifdef __cplusplus

lib/ipc_int.h

@@ -156,12 +156,19 @@ enum qb_ipcs_connection_state {
 
 #define CONNECTION_DESCRIPTION (16)
 
+struct qb_ipcs_connection_auth {
+	uid_t uid;
+	gid_t gid;
+	mode_t mode;
+};
+
 struct qb_ipcs_connection {
 	enum qb_ipcs_connection_state state;
 	int32_t refcount;
 	pid_t pid;
 	uid_t euid;
 	gid_t egid;
+	struct qb_ipcs_connection_auth auth;
 	struct qb_ipc_one_way setup;
 	struct qb_ipc_one_way request;
 	struct qb_ipc_one_way response;

lib/ipc_shm.c

@@ -233,6 +233,40 @@ qb_ipcs_shm_disconnect(struct qb_ipcs_connection *c)
 	}
 }
 
+static int32_t
+qb_ipcs_shm_rb_open(struct qb_ipcs_connection *c,
+		    struct qb_ipc_one_way *ow,
+		    const char *rb_name)
+{
+	int32_t res = 0;
+
+	ow->u.shm.rb = qb_rb_open(rb_name,
+				  ow->max_msg_size,
+				  QB_RB_FLAG_CREATE |
+				  QB_RB_FLAG_SHARED_PROCESS,
+				  sizeof(int32_t));
+	if (ow->u.shm.rb == NULL) {
+		res = -errno;
+		qb_util_perror(LOG_ERR, "qb_rb_open:%s", rb_name);
+		return res;
+	}
+	res = qb_rb_chown(ow->u.shm.rb, c->auth.uid, c->auth.gid);
+	if (res != 0) {
+		qb_util_perror(LOG_ERR, "qb_rb_chown:%s", rb_name);
+		goto cleanup;
+	}
+	res = qb_rb_chmod(ow->u.shm.rb, c->auth.mode);
+	if (res != 0) {
+		qb_util_perror(LOG_ERR, "qb_rb_chmod:%s", rb_name);
+		goto cleanup;
+	}
+	return res;
+
+cleanup:
+	qb_rb_close(ow->u.shm.rb);
+	return res;
+}
+
 static int32_t
 qb_ipcs_shm_connect(struct qb_ipcs_service *s,
 		    struct qb_ipcs_connection *c,
@@ -249,59 +283,27 @@ qb_ipcs_shm_connect(struct qb_ipcs_service *s,
 	snprintf(r->event, NAME_MAX, "%s-event-%s",
 		 s->name, c->description);
 
-	c->request.u.shm.rb = qb_rb_open(r->request,
-					 c->request.max_msg_size,
-					 QB_RB_FLAG_CREATE |
-					 QB_RB_FLAG_SHARED_PROCESS,
-					 sizeof(int32_t));
-	if (c->request.u.shm.rb == NULL) {
-		res = -errno;
-		qb_util_perror(LOG_ERR, "qb_rb_open:%s", r->request);
-		goto cleanup;
-	}
-	res = qb_rb_chown(c->request.u.shm.rb, c->euid, c->egid);
+	res = qb_ipcs_shm_rb_open(c, &c->request,
+				  r->request);
 	if (res != 0) {
-		qb_util_perror(LOG_ERR, "qb_rb_chown:%s", r->request);
 		goto cleanup;
 	}
 
-	c->response.u.shm.rb = qb_rb_open(r->response,
-					  c->response.max_msg_size,
-					  QB_RB_FLAG_CREATE |
-					  QB_RB_FLAG_SHARED_PROCESS, 0);
-	if (c->response.u.shm.rb == NULL) {
-		res = -errno;
-		qb_util_perror(LOG_ERR, "qb_rb_open:%s", r->response);
-		goto cleanup_request;
-	}
-	res = qb_rb_chown(c->response.u.shm.rb, c->euid, c->egid);
+	res = qb_ipcs_shm_rb_open(c, &c->response,
+				  r->response);
 	if (res != 0) {
-		qb_util_perror(LOG_ERR, "qb_rb_chown:%s", r->response);
 		goto cleanup_request;
 	}
 
-	c->event.u.shm.rb = qb_rb_open(r->event,
-				       c->event.max_msg_size,
-				       QB_RB_FLAG_CREATE |
-				       QB_RB_FLAG_SHARED_PROCESS, 0);
-
-	if (c->event.u.shm.rb == NULL) {
-		res = -errno;
-		qb_util_perror(LOG_ERR, "qb_rb_open:%s", r->event);
-		goto cleanup_request_response;
-	}
-	res = qb_rb_chown(c->event.u.shm.rb, c->euid, c->egid);
+	res = qb_ipcs_shm_rb_open(c, &c->event,
+				  r->event);
 	if (res != 0) {
-		qb_util_perror(LOG_ERR, "qb_rb_chown:%s", r->event);
-		goto cleanup_all;
+		goto cleanup_request_response;
 	}
 
 	r->hdr.error = 0;
 	return 0;
 
-cleanup_all:
-	qb_rb_close(c->event.u.shm.rb);
-
 cleanup_request_response:
 	qb_rb_close(c->request.u.shm.rb);
 

lib/ipc_us.c

@@ -615,8 +615,9 @@ handle_new_connection(struct qb_ipcs_service *s,
 	c->response.max_msg_size = req->max_msg_size;
 	c->event.max_msg_size = req->max_msg_size;
 	c->pid = ugp->pid;
-	c->euid = ugp->uid;
-	c->egid = ugp->gid;
+	c->auth.uid = c->euid = ugp->uid;
+	c->auth.gid = c->egid = ugp->gid;
+	c->auth.mode = 0600;
 	c->stats.client_pid = ugp->pid;
 	snprintf(c->description, CONNECTION_DESCRIPTION,
 		 "%d-%d-%d", s->pid, ugp->pid,
@@ -949,12 +950,19 @@ qb_ipcs_us_connect(struct qb_ipcs_service *s,
 	}
 	(void)strlcpy(r->request, path, PATH_MAX);
 	(void)strlcpy(c->request.u.us.shared_file_name, r->request, NAME_MAX);
-	res = chown(r->request, c->euid, c->egid);
+	res = chown(r->request, c->auth.uid, c->auth.gid);
 	if (res != 0) {
 		/* ignore res, this is just for the compiler warnings.
 		 */
 		res = 0;
 	}
+	res = chmod(r->request, c->auth.mode);
+	if (res != 0) {
+		/* ignore res, this is just for the compiler warnings.
+		*/
+		res = 0;
+	}
+
 	shm_ptr = mmap(0, SHM_CONTROL_SIZE,
 		       PROT_READ | PROT_WRITE, MAP_SHARED, fd_hdr, 0);
 

lib/ipcs.c

@@ -864,3 +864,14 @@ qb_ipcs_stats_get(struct qb_ipcs_service * s,
 	}
 	return 0;
 }
+
+void
+qb_ipcs_connection_auth_set(qb_ipcs_connection_t *c, uid_t uid,
+			    gid_t gid, mode_t mode)
+{
+	if (c) {
+		c->auth.uid = uid;
+		c->auth.gid = gid;
+		c->auth.mode = mode;
+	}
+}

lib/ringbuffer.c

@@ -769,3 +769,22 @@ qb_rb_chown(struct qb_ringbuffer_s * rb, uid_t owner, gid_t group)
 	}
 	return 0;
 }
+
+int32_t
+qb_rb_chmod(qb_ringbuffer_t * rb, mode_t mode)
+{
+	int32_t res;
+
+	if (rb == NULL) {
+		return -EINVAL;
+	}
+	res = chmod(rb->shared_hdr->data_path, mode);
+	if (res < 0) {
+		return -errno;
+	}
+	res = chmod(rb->shared_hdr->hdr_path, mode);
+	if (res < 0) {
+		return -errno;
+	}
+	return 0;
+}