mgcp: permit wildcarded endpoint assignment (CRCX)
The mgcp protocol in general allows wildcarded endpoints on CRCX.
osmo-mgw does not support this feature yet.
- when the endpoint name contains a wildcard character, search
a free endpoint automatically
- return the resulting endpoint name in the parameter section of
the mgcp response
- add parsing support for the returned endpoint names
- Be more concious about the parameters that are returned with
each response. Do not unnecessarily attach known parameters.
Return the connection ID only on CRCX commands. Only return
the endpoint ID on CRCX commands that are wildcarded.
Change-Id: Iebc95043569191b6f5fbc8fe266b13fcfcab2e48
related: OS#2631
diff --git a/src/libosmo-mgcp-client/mgcp_client.c b/src/libosmo-mgcp-client/mgcp_client.c
index 116baf3..a394f3b 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -146,8 +146,6 @@
/* Mark the end of the comment */
*end = '\0';
r->body = end + 1;
- if (r->body[0] == '\n')
- r->body ++;
return 0;
response_parse_failure:
@@ -247,6 +245,10 @@
OSMO_ASSERT(r->body);
char *data = mgcp_find_section_end(r->body);
+ /* Warning: This function performs a destructive parsing on r->body.
+ * Since this function is called at the very end of the persing
+ * process, destructive parsing is acceptable. */
+
if (!data) {
LOGP(DLMGCP, LOGL_ERROR,
"MGCP response: cannot find start of parameters\n");
@@ -282,21 +284,29 @@
return 0;
}
-/* Parse a line like "I: 0cedfd5a19542d197af9afe5231f1d61" */
-static int mgcp_parse_conn_id(struct mgcp_response *r, const char *line)
+/* Parse a line like "X: something" */
+static int mgcp_parse_head_param(char *result, unsigned int result_len,
+ char label, const char *line)
{
+ char label_string[4];
+
+ /* Detect empty parameters */
if (strlen(line) < 4)
goto response_parse_failure;
- if (memcmp("I: ", line, 3) != 0)
+ /* Check if the label matches */
+ snprintf(label_string, sizeof(label_string), "%c: ", label);
+ if (memcmp(label_string, line, 3) != 0)
goto response_parse_failure;
- osmo_strlcpy(r->head.conn_id, line + 3, sizeof(r->head.conn_id));
+ /* Copy payload part of the string to destinations (the label string
+ * is always 3 chars long) */
+ osmo_strlcpy(result, line + 3, result_len);
return 0;
response_parse_failure:
LOGP(DLMGCP, LOGL_ERROR,
- "Failed to parse MGCP response (connectionIdentifier)\n");
+ "Failed to parse MGCP response (parameter label: %c)\n", label);
return -EINVAL;
}
@@ -306,18 +316,37 @@
char *line;
int rc = 0;
OSMO_ASSERT(r->body);
- char *data = r->body;
- char *data_end = mgcp_find_section_end(r->body);
+ char *data;
+ char *data_ptr;
+ char *data_end;
- /* Protect SDP body, for_each_non_empty_line() will
- * only parse until it hits \0 mark. */
+ /* Since this functions performs a destructive parsing, we create a
+ * local copy of the body data */
+ data = talloc_zero_size(NULL, strlen(r->body)+1);
+ OSMO_ASSERT(data);
+ data_ptr = data;
+ osmo_strlcpy(data, r->body, strlen(r->body));
+
+ /* If there is an SDP body attached, prevent for_each_non_empty_line()
+ * into running in there, we are not yet interested in the parameters
+ * stored there. */
+ data_end = mgcp_find_section_end(data);
if (data_end)
*data_end = '\0';
- for_each_non_empty_line(line, data) {
+ for_each_non_empty_line(line, data_ptr) {
switch (line[0]) {
+ case 'Z':
+ rc = mgcp_parse_head_param(r->head.endpoint,
+ sizeof(r->head.endpoint),
+ 'Z', line);
+ if (rc)
+ goto exit;
+ break;
case 'I':
- rc = mgcp_parse_conn_id(r, line);
+ rc = mgcp_parse_head_param(r->head.conn_id,
+ sizeof(r->head.conn_id),
+ 'I', line);
if (rc)
goto exit;
break;
@@ -327,10 +356,7 @@
}
}
exit:
- /* Restore original state */
- if (data_end)
- *data_end = '\n';
-
+ talloc_free(data);
return rc;
}