7 Mar
2025
7 Mar
'25
4:53 p.m.
pespin has uploaded this change for review. (
https://gerrit.osmocom.org/c/osmo-mgw/+/39738?usp=email )
Change subject: mgw: Split MDCX read-only validations into its own function
......................................................................
mgw: Split MDCX read-only validations into its own function
The SDP parsing is moved to a step beforehand, so that validation of
full message can be done in a subsequent step. That validation step is
moved into a function to give some air to handle_modify_con() and easily
spot the logic.
Change-Id: I469413dbe89cc4795deb50d76b434655cba9b776
---
M src/libosmo-mgcp/mgcp_protocol.c
1 file changed, 47 insertions(+), 26 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/38/39738/1
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index ef0aad4..79a647a 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -849,6 +849,48 @@
return create_err_response(endp, endp, error_code, "CRCX", pdata->trans);
}
+/* Read-only checks for parsed MDCX request.
+ * Returns negative MGCP error code on failure, 0 on scucess. */
+static int validate_parsed_mdcx(struct mgcp_request_data *rq)
+{
+ struct mgcp_parse_data *pdata = rq->pdata;
+ struct mgcp_trunk *trunk = rq->trunk;
+ struct mgcp_endpoint *endp = rq->endp;
+ struct mgcp_parse_hdr_pars *hpars = &pdata->hpars;
+ struct rate_ctr_group *rate_ctrs = trunk->ratectr.mgcp_mdcx_ctr_group;
+ int error_code;
+
+ if (mgcp_endp_num_conns(endp) <= 0) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR,
+ "MDCX: endpoint is not holding a connection.\n");
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_NO_CONN));
+ return -400;
+ }
+
+ /* If a CallID is provided during MDCX, validate (unless endp was explicitly configured
to ignore
+ * it through "X-Osmo-IGN: C") that it matches the one previously set. */
+ if (hpars->callid &&
+ !(endp->x_osmo_ign & MGCP_X_OSMO_IGN_CALLID) &&
+ mgcp_verify_call_id(endp, hpars->callid) < 0) {
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_INVALID_CALLID));
+ return -516;
+ }
+
+ if (!hpars->connid) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR,
+ "MDCX: insufficient parameters, missing ci (connectionIdentifier)\n");
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_NO_CONNID));
+ return -515;
+ }
+ if ((error_code = mgcp_verify_ci(endp, hpars->connid)) != 0) {
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_INVALID_CONNID));
+ return -error_code;
+ }
+
+ /* Everything fine, continue */
+ return 0;
+}
+
/* MDCX command handler, processes the received command */
static struct msgb *handle_modify_con(struct mgcp_request_data *rq)
{
@@ -870,7 +912,7 @@
LOGP(DLMGCP, LOGL_ERROR, "MDCX: Not allowed in 'null' endpoint!\n");
return create_err_response(rq->cfg, NULL, 502, "MDCX", pdata->trans);
}
-
+ /* rq->trunk is available (non-null) from here on. */
rate_ctrs = trunk->ratectr.mgcp_mdcx_ctr_group;
/* Prohibit wildcarded requests */
@@ -886,36 +928,11 @@
LOGPENDP(endp, DLMGCP, LOGL_ERROR, "MDCX: selected endpoint not
available!\n");
return create_err_response(rq->trunk, NULL, 501, "MDCX",
pdata->trans);
}
- if (mgcp_endp_num_conns(endp) <= 0) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "MDCX: endpoint is not holding a connection.\n");
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_NO_CONN));
- return create_err_response(endp, endp, 400, "MDCX", pdata->trans);
- }
rc = mgcp_parse_hdr_pars(pdata);
if (rc < 0)
return create_err_response(rq->trunk, NULL, -rc, "MDCX",
pdata->trans);
- /* If a CallID is provided during MDCX, validate (unless endp was explicitly configured
to ignore it
- * through "X-Osmo-IGN: C") that it matches the one previously set. */
- if (hpars->callid &&
- !(endp->x_osmo_ign & MGCP_X_OSMO_IGN_CALLID) &&
- mgcp_verify_call_id(endp, hpars->callid) < 0) {
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_INVALID_CALLID));
- return create_err_response(endp, endp, 516, "MDCX", pdata->trans);
- }
-
- if (!hpars->connid) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "MDCX: insufficient parameters, missing ci (connectionIdentifier)\n");
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_NO_CONNID));
- return create_err_response(endp, endp, 515, "MDCX", pdata->trans);
- } else if ((error_code = mgcp_verify_ci(endp, hpars->connid)) != 0) {
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_INVALID_CONNID));
- return create_err_response(endp, endp, error_code, "MDCX", pdata->trans);
- }
-
/* Parse SDP if found: */
if (hpars->have_sdp) {
rc = mgcp_parse_sdp_data(pdata);
@@ -926,6 +943,10 @@
}
}
+ rc = validate_parsed_mdcx(rq);
+ if (rc < 0)
+ return create_err_response(rq->trunk, NULL, -rc, "MDCX",
pdata->trans);
+
conn = mgcp_endp_get_conn(endp, hpars->connid);
if (!conn) {
rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_MDCX_FAIL_CONN_NOT_FOUND));
--
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Gerrit-MessageType: newchange
Gerrit-Project: osmo-mgw
Gerrit-Branch: master
Gerrit-Change-Id: I469413dbe89cc4795deb50d76b434655cba9b776
Gerrit-Change-Number: 39738
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin(a)sysmocom.de>