sbus: Add the sbus_request_parse_or_finish() method

Some DBus types returned from dbus_message_get_args() require memory
to be released when done. We automatically attach these to the talloc
struct sbus_request memory context in this function.

This accepts varargs similar to dbus_message_get_args(), which are
rather awkward. However instead of reworking them completely, future
generated marshalling code will replace most uses of these varargs.

If parsing the dbus message fails, then it responds to the DBus caller
with an appropriate error such as o.f.D.Error.InvalidArgs. In these
cases (ie: when it returns FALSE) the sbus_request is finished.

Migrated some, but not all, uses of dbus_message_get_args() to the
new function. Some instances have uncommon semantics such as terminating
the connection upon failure to parse a message.

Reviewed-by: Jakub Hrozek <jhrozek@redhat.com>
Reviewed-by: Pavel Březina <pbrezina@redhat.com>
Reviewed-by: Lukáš Slebodník <lslebodn@redhat.com>

2 files changed, 27 insertions, 64 deletions

diff --git a/src/providers/data_provider_be.c b/src/providers/data_provider_be.c
index 6c0a82360..0957bedc0 100644
--- a/src/providers/data_provider_be.c
+++ b/src/providers/data_provider_be.c
@@ -564,7 +564,6 @@ static int be_get_subdomains(struct sbus_request *dbus_req, void *user_data)
     struct be_subdom_req *req;
     struct be_req *be_req = NULL;
     struct be_client *becli;
-    DBusError dbus_error;
     dbus_bool_t force;
     char *domain_hint;
     dbus_uint16_t err_maj;
@@ -575,17 +574,11 @@ static int be_get_subdomains(struct sbus_request *dbus_req, void *user_data)
     becli = talloc_get_type(user_data, struct be_client);
     if (!becli) return EINVAL;
 
-    dbus_error_init(&dbus_error);
-
-    ret = dbus_message_get_args(dbus_req->message, &dbus_error,
-                                DBUS_TYPE_BOOLEAN, &force,
-                                DBUS_TYPE_STRING, &domain_hint,
-                                DBUS_TYPE_INVALID);
-    if (!ret) {
-        DEBUG(SSSDBG_CRIT_FAILURE,"Failed, to parse message!\n");
-        if (dbus_error_is_set(&dbus_error)) dbus_error_free(&dbus_error);
-        return EIO;
-    }
+    if (!sbus_request_parse_or_finish(dbus_req,
+                                      DBUS_TYPE_BOOLEAN, &force,
+                                      DBUS_TYPE_STRING, &domain_hint,
+                                      DBUS_TYPE_INVALID))
+        return EOK; /* handled */
 
     /* return an error if corresponding backend target is not configured */
     if (becli->bectx->bet_info[BET_SUBDOMAINS].bet_ops == NULL) {
@@ -1042,7 +1035,6 @@ static int be_get_account_info(struct sbus_request *dbus_req, void *user_data)
     struct be_acct_req *req;
     struct be_req *be_req;
     struct be_client *becli;
-    DBusError dbus_error;
     uint32_t type;
     char *filter;
     char *domain;
@@ -1057,19 +1049,13 @@ static int be_get_account_info(struct sbus_request *dbus_req, void *user_data)
     becli = talloc_get_type(user_data, struct be_client);
     if (!becli) return EINVAL;
 
-    dbus_error_init(&dbus_error);
-
-    ret = dbus_message_get_args(dbus_req->message, &dbus_error,
-                                DBUS_TYPE_UINT32, &type,
-                                DBUS_TYPE_UINT32, &attr_type,
-                                DBUS_TYPE_STRING, &filter,
-                                DBUS_TYPE_STRING, &domain,
-                                DBUS_TYPE_INVALID);
-    if (!ret) {
-        DEBUG(SSSDBG_CRIT_FAILURE,"Failed, to parse message!\n");
-        if (dbus_error_is_set(&dbus_error)) dbus_error_free(&dbus_error);
-        return EIO;
-    }
+    if (!sbus_request_parse_or_finish(dbus_req,
+                                      DBUS_TYPE_UINT32, &type,
+                                      DBUS_TYPE_UINT32, &attr_type,
+                                      DBUS_TYPE_STRING, &filter,
+                                      DBUS_TYPE_STRING, &domain,
+                                      DBUS_TYPE_INVALID))
+        return EOK; /* handled */
 
     DEBUG(SSSDBG_CONF_SETTINGS,
           "Got request for [%u][%d][%s]\n", type, attr_type, filter);
@@ -1613,7 +1599,6 @@ static void be_autofs_handler_callback(struct be_req *req,
 
 static int be_autofs_handler(struct sbus_request *dbus_req, void *user_data)
 {
-    DBusError dbus_error;
     struct be_client *be_cli = NULL;
     struct be_req *be_req = NULL;
     struct be_autofs_req *be_autofs_req = NULL;
@@ -1633,17 +1618,11 @@ static int be_autofs_handler(struct sbus_request *dbus_req, void *user_data)
         return EINVAL;
     }
 
-    dbus_error_init(&dbus_error);
-
-    ret = dbus_message_get_args(dbus_req->message, &dbus_error,
-                                DBUS_TYPE_UINT32, &type,
-                                DBUS_TYPE_STRING, &filter,
-                                DBUS_TYPE_INVALID);
-    if (!ret) {
-        DEBUG(SSSDBG_CRIT_FAILURE, "Failed, to parse message!\n");
-        if (dbus_error_is_set(&dbus_error)) dbus_error_free(&dbus_error);
-        return EIO;
-    }
+    if (!sbus_request_parse_or_finish(dbus_req,
+                                      DBUS_TYPE_UINT32, &type,
+                                      DBUS_TYPE_STRING, &filter,
+                                      DBUS_TYPE_INVALID))
+        return EOK; /* handled */
 
     /* If we are offline and fast reply was requested
      * return offline immediately
@@ -1817,7 +1796,6 @@ static int be_host_handler(struct sbus_request *dbus_req, void *user_data)
     struct be_host_req *req;
     struct be_req *be_req;
     struct be_client *becli;
-    DBusError dbus_error;
     uint32_t flags;
     char *filter;
     int ret;
@@ -1830,17 +1808,11 @@ static int be_host_handler(struct sbus_request *dbus_req, void *user_data)
     becli = talloc_get_type(user_data, struct be_client);
     if (!becli) return EINVAL;
 
-    dbus_error_init(&dbus_error);
-
-    ret = dbus_message_get_args(dbus_req->message, &dbus_error,
-                                DBUS_TYPE_UINT32, &flags,
-                                DBUS_TYPE_STRING, &filter,
-                                DBUS_TYPE_INVALID);
-    if (!ret) {
-        DEBUG(SSSDBG_CRIT_FAILURE, "Failed, to parse message!\n");
-        if (dbus_error_is_set(&dbus_error)) dbus_error_free(&dbus_error);
-        return EIO;
-    }
+    if (!sbus_request_parse_or_finish(dbus_req,
+                                      DBUS_TYPE_UINT32, &flags,
+                                      DBUS_TYPE_STRING, &filter,
+                                      DBUS_TYPE_INVALID))
+        return EOK; /* request finished */
 
     DEBUG(SSSDBG_TRACE_LIBS,
           "Got request for [%u][%s]\n", flags, filter);
diff --git a/src/providers/proxy/proxy_init.c b/src/providers/proxy/proxy_init.c
index 0206ec15b..dd1b75826 100644
--- a/src/providers/proxy/proxy_init.c
+++ b/src/providers/proxy/proxy_init.c
@@ -397,10 +397,8 @@ static int client_registration(struct sbus_request *dbus_req, void *data)
     dbus_uint16_t version = DATA_PROVIDER_VERSION;
     struct sbus_connection *conn;
     struct proxy_client *proxy_cli;
-    DBusError dbus_error;
     dbus_uint16_t cli_ver;
     uint32_t cli_id;
-    dbus_bool_t dbret;
     int hret;
     hash_key_t key;
     hash_value_t value;
@@ -421,19 +419,12 @@ static int client_registration(struct sbus_request *dbus_req, void *data)
           "Cancel proxy client ID timeout [%p]\n", proxy_cli->timeout);
     talloc_zfree(proxy_cli->timeout);
 
-    dbus_error_init(&dbus_error);
-
-    dbret = dbus_message_get_args(dbus_req->message, &dbus_error,
-                                  DBUS_TYPE_UINT16, &cli_ver,
-                                  DBUS_TYPE_UINT32, &cli_id,
-                                  DBUS_TYPE_INVALID);
-    if (!dbret) {
-        DEBUG(SSSDBG_CRIT_FAILURE,
-              "Failed to parse message, killing connection\n");
-        if (dbus_error_is_set(&dbus_error)) dbus_error_free(&dbus_error);
+    if (!sbus_request_parse_or_finish(dbus_req,
+                                      DBUS_TYPE_UINT16, &cli_ver,
+                                      DBUS_TYPE_UINT32, &cli_id,
+                                      DBUS_TYPE_INVALID)) {
         sbus_disconnect(conn);
-        /* FIXME: should we just talloc_zfree(conn) ? */
-        return EIO;
+        return EOK; /* handled */
     }
 
     DEBUG(SSSDBG_FUNC_DATA, "Proxy client [%"PRIu32"] connected\n", cli_id);