mgcp-client: Introduce API mgcp_client_pool_config_write
It is not a good idea to use a personal write_config function for the
MGW node, since it's not meant to be a 1st level (top) node.
During write-config the node function will be called at an
implementation specific time (based on the order defined by the app in
the node type enum), so there's no real way to control that the output
of the MGW node will end up under the parent configured in
mgcp_client_pool_vty_init(). As mentioned the order can be tweaked based
on how the node enums are configured, installed, etc. but that's really
a nightmare, so let's better not rely on that.
Therefore, this patch introduces a new API which the users (apps such as
OsmoBSc and OsmoMSC) can use to write the config at the required time
(when writing its own parent node).
A hack is introduced internally to detect older versions of the users
which didn't call this function to still print stuff (up to to the app
if the order is correct).
Related: SYS#5987
Change-Id: I7a620cf47886d8ecab30ce369cf123d98ab842c5
diff --git a/TODO-RELEASE b/TODO-RELEASE
index 5fe3d53..3e10bf9 100644
--- a/TODO-RELEASE
+++ b/TODO-RELEASE
@@ -26,4 +26,4 @@
#library what description / commit summary line
libosmo-netif >1.2.0 OSMUX_DEFAULT_PORT, osmux_xfrm_output_*, osmux_xfrm_input_*
libosmocore >1.7.0 osmo_sockaddr_is_any()
-libmgcp-client NEW APIs mgcp_client_pool_member_...()
\ No newline at end of file
+libmgcp-client NEW APIs mgcp_client_pool_member_...(), mgcp_client_pool_config_write()
\ No newline at end of file
diff --git a/include/osmocom/mgcp_client/mgcp_client_pool.h b/include/osmocom/mgcp_client/mgcp_client_pool.h
index b547b78..46d7e90 100644
--- a/include/osmocom/mgcp_client/mgcp_client_pool.h
+++ b/include/osmocom/mgcp_client/mgcp_client_pool.h
@@ -9,6 +9,7 @@
struct mgcp_client_pool *mgcp_client_pool_alloc(void *talloc_ctx);
void mgcp_client_pool_vty_init(int parent_node, int mgw_node, const char *indent, struct mgcp_client_pool *pool);
+int mgcp_client_pool_config_write(struct vty *vty, const char *indent);
unsigned int mgcp_client_pool_connect(struct mgcp_client_pool *pool);
void mgcp_client_pool_register_single(struct mgcp_client_pool *pool, struct mgcp_client *mgcp_client);
diff --git a/src/libosmo-mgcp-client/mgcp_client_vty.c b/src/libosmo-mgcp-client/mgcp_client_vty.c
index 1672f97..b571fa0 100644
--- a/src/libosmo-mgcp-client/mgcp_client_vty.c
+++ b/src/libosmo-mgcp-client/mgcp_client_vty.c
@@ -330,18 +330,46 @@
vty_init_common(talloc_ctx, node);
}
+/* Deprecated, used for backward compatibility with older users which didn't call
+ * mgcp_client_pool_config_write(): */
+static bool mgcp_client_pool_config_write_called = false;
static int config_write_pool(struct vty *vty)
{
+ int rc;
+ if (mgcp_client_pool_config_write_called)
+ return CMD_SUCCESS;
+
+ rc = mgcp_client_pool_config_write(vty, NULL);
+ /* mgcp_client_pool_config_write sets this to true, let's reset it */
+ mgcp_client_pool_config_write_called = false;
+ return rc;
+}
+
+/*! Write out MGCP client config to VTY.
+ * \param[in] vty VTY to which we should print.
+ * \param[in] indent string used for indentation (e.g. " ").
+ If NULL, indentation passed during mgcp_client_pool_vty_init() will be used.
+ * \returns CMD_SUCCESS on success, CMD_WARNING on error */
+int mgcp_client_pool_config_write(struct vty *vty, const char *indent)
+{
struct mgcp_client_pool *pool = global_mgcp_client_pool;
struct mgcp_client_pool_member *pool_member;
- unsigned int indent_buf_len = strlen(pool->vty_indent) + 1 + 1;
- char *indent = talloc_zero_size(vty, indent_buf_len);
+ unsigned int subindent_buf_len;
+ char *subindent;
- snprintf(indent, indent_buf_len, "%s ", pool->vty_indent);
+ /* Tell internal node write function that the user supports calling proper API: */
+ mgcp_client_pool_config_write_called = true;
+
+ if (!indent)
+ indent = pool->vty_indent ? : "";
+ subindent_buf_len = strlen(indent) + 1 + 1;
+ subindent = talloc_zero_size(vty, subindent_buf_len);
+
+ snprintf(subindent, subindent_buf_len, "%s ", indent);
llist_for_each_entry(pool_member, &pool->member_list, list) {
- vty_out(vty, "%smgw %u%s", pool->vty_indent, pool_member->nr, VTY_NEWLINE);
- config_write(vty, indent, &pool_member->conf);
+ vty_out(vty, "%smgw %u%s", indent, pool_member->nr, VTY_NEWLINE);
+ config_write(vty, subindent, &pool_member->conf);
}
/* MGW pool API is supported by user (global_mgcp_client_pool is set
@@ -350,11 +378,11 @@
* replacing it, then output the single MGW converted to the new MGW
* pool VTY. */
if (llist_empty(&pool->member_list) && pool->mgcp_client_single) {
- vty_out(vty, "%smgw 0%s", pool->vty_indent, VTY_NEWLINE);
- config_write(vty, indent, global_mgcp_client_conf);
+ vty_out(vty, "%smgw 0%s", indent, VTY_NEWLINE);
+ config_write(vty, subindent, global_mgcp_client_conf);
}
- talloc_free(indent);
+ talloc_free(subindent);
return CMD_SUCCESS;
}
@@ -495,7 +523,8 @@
* (called once at startup by the application process).
* \param[in] parent_node identifier of the parent node on which the mgw node appears.
* \param[in] mgw_node identifier that should be used with the newly installed MGW node.
- * \param[in] indent indentation string to match the indentation in the VTY config
+ * \param[in] indent indentation string to match the indentation in the VTY config.
+ If NULL, it must be passed explicitly each time mgcp_client_pool_config_write() is called.
* \param[in] pool user provided memory to store the configured MGCP client (MGW) pool. */
void mgcp_client_pool_vty_init(int parent_node, int mgw_node, const char *indent, struct mgcp_client_pool *pool)
{
@@ -503,11 +532,12 @@
OSMO_ASSERT(pool);
/* Never allow this function to be called twice on the same pool */
- OSMO_ASSERT(!pool->vty_indent);
OSMO_ASSERT(!pool->vty_node);
- pool->vty_indent = talloc_strdup(pool, indent);
- OSMO_ASSERT(pool->vty_indent);
+ if (indent) {
+ pool->vty_indent = talloc_strdup(pool, indent);
+ OSMO_ASSERT(pool->vty_indent);
+ }
pool->vty_node = talloc_zero(pool, struct cmd_node);
OSMO_ASSERT(pool->vty_node);
pool->vty_node->node = mgw_node;
@@ -517,6 +547,9 @@
install_lib_element(parent_node, &cfg_mgw_cmd);
install_lib_element(parent_node, &cfg_no_mgw_cmd);
+ /* Note: config_write_pool is deprecated and user is expected to
+ * manually call mgcp_client_pool_config_write() when printing the VTY
+ * config */
install_node(pool->vty_node, config_write_pool);
vty_init_common(pool, mgw_node);