pespin has uploaded this change for review.
mgw: Split CRCX 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_create_con() and easily
spot the logic.
The logic based on force_realloc is split so that code modifying the
object is moved to the later update step.
Change-Id: I639ad0a25a0af4a4637045ca8bf61e436a789426
---
M src/libosmo-mgcp/mgcp_protocol.c
1 file changed, 108 insertions(+), 80 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/36/39736/1
diff --git a/src/libosmo-mgcp/mgcp_protocol.c b/src/libosmo-mgcp/mgcp_protocol.c
index 49a4e83..0e0f9dd 100644
--- a/src/libosmo-mgcp/mgcp_protocol.c
+++ b/src/libosmo-mgcp/mgcp_protocol.c
@@ -567,6 +567,87 @@
return 534;
}
+/* Read-only checks for parsed CRCX request.
+ * Returns negative MGCP error code on failure, 0 on scucess. */
+static int validate_parsed_crcx(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_crcx_ctr_group;
+
+ /* Check parameters */
+ if (!hpars->callid) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR,
+ "CRCX: insufficient parameters, missing callid\n");
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_MISSING_CALLID));
+ return -516;
+ }
+
+ if (hpars->mode == MGCP_CONN_NONE) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR,
+ "CRCX: insufficient parameters, invalid mode\n");
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_INVALID_MODE));
+ return -517;
+ }
+
+ /* It is illegal to send a connection identifier
+ * together with a CRCX, the MGW will assign the
+ * connection identifier by itself on CRCX */
+ if (hpars->connid) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: 'I: %s' not expected!\n", hpars->connid);
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_BAD_ACTION));
+ return -523;
+ }
+
+ /* Reject osmux if disabled by config */
+ if (trunk->cfg->osmux.usage == OSMUX_USAGE_OFF &&
+ hpars->remote_osmux_cid != MGCP_PARSE_HDR_PARS_OSMUX_CID_UNSET) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: Request with Osmux but it is disabled by config!\n");
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_NO_OSMUX));
+ return -511;
+ }
+ /* Reject non-osmux if required by config */
+ if (trunk->cfg->osmux.usage == OSMUX_USAGE_ONLY &&
+ hpars->remote_osmux_cid == MGCP_PARSE_HDR_PARS_OSMUX_CID_UNSET) {
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: Request without Osmux but it is required by config!\n");
+ return -517;
+ }
+
+ /* Read-only checks here, force_realloc case done out of there afterwards.*/
+ if (!trunk->force_realloc) {
+ /* Check if we are able to accept the creation of another connection */
+ if (mgcp_endp_is_full(endp)) {
+ /* There is no more room for a connection, leave
+ * everything as it is and return with an error */
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: endpoint full, max. %d connections allowed!\n",
+ endp->type->max_conns);
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_LIMIT_EXCEEDED));
+ return -540;
+ }
+
+ /* Check if this endpoint already serves a call, if so, check if the
+ * callids match up so that we are sure that this is our call.
+ * Do check only if endpoint was (or is by current CRCX) configured
+ * to explicitly ignore it ("X-Osmo-IGN: C").
+ */
+ if (endp->callid &&
+ !((endp->x_osmo_ign | hpars->x_osmo_ign) & MGCP_X_OSMO_IGN_CALLID) &&
+ mgcp_verify_call_id(endp, hpars->callid)) {
+ /* This is not our call, leave everything as it is and
+ * return with an error. */
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: already seized by other call (%s)\n",
+ endp->callid);
+ rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_UNKNOWN_CALLID));
+ return -400;
+ }
+ }
+
+ /* Everything fine, continue */
+ return 0;
+}
+
/* CRCX command handler, processes the received command */
static struct msgb *handle_create_con(struct mgcp_request_data *rq)
{
@@ -589,6 +670,7 @@
return create_err_response(rq->cfg, NULL, 502, "CRCX", pdata->trans);
}
+ /* rq->trunk is available (non-null) from here on. */
rate_ctrs = trunk->ratectr.mgcp_crcx_ctr_group;
/* we must have a free ep */
@@ -617,30 +699,6 @@
return create_err_response(rq->trunk, NULL, -rc, "CRCX", pdata->trans);
}
- /* Check parameters */
- if (!hpars->callid) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "CRCX: insufficient parameters, missing callid\n");
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_MISSING_CALLID));
- return create_err_response(endp, endp, 516, "CRCX", pdata->trans);
- }
-
- if (hpars->mode == MGCP_CONN_NONE) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "CRCX: insufficient parameters, invalid mode\n");
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_INVALID_MODE));
- return create_err_response(endp, endp, 517, "CRCX", pdata->trans);
- }
-
- /* It is illegal to send a connection identifier
- * together with a CRCX, the MGW will assign the
- * connection identifier by itself on CRCX */
- if (hpars->connid) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: 'I: %s' not expected!\n", hpars->connid);
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_BAD_ACTION));
- return create_err_response(endp, endp, 523, "CRCX", pdata->trans);
- }
-
/* Parse SDP if found: */
if (hpars->have_sdp) {
rc = mgcp_parse_sdp_data(pdata);
@@ -650,67 +708,37 @@
}
}
- /* Reject osmux if disabled by config */
- if (trunk->cfg->osmux.usage == OSMUX_USAGE_OFF &&
- hpars->remote_osmux_cid != MGCP_PARSE_HDR_PARS_OSMUX_CID_UNSET) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: Request with Osmux but it is disabled by config!\n");
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_NO_OSMUX));
- return create_err_response(endp, endp, 511, "CRCX", pdata->trans);
- }
- /* Reject non-osmux if required by config */
- if (trunk->cfg->osmux.usage == OSMUX_USAGE_ONLY &&
- hpars->remote_osmux_cid == MGCP_PARSE_HDR_PARS_OSMUX_CID_UNSET) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: Request without Osmux but it is required by config!\n");
- return create_err_response(endp, endp, 517, "CRCX", pdata->trans);
- }
-
- /* Check if we are able to accept the creation of another connection */
- if (mgcp_endp_is_full(endp)) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "CRCX: endpoint full, max. %i connections allowed!\n",
- endp->type->max_conns);
- if (trunk->force_realloc) {
- /* There is no more room for a connection, make some
- * room by blindly tossing the oldest of the two two
- * connections */
- mgcp_endp_free_conn_oldest(endp);
- OSMO_ASSERT(!mgcp_endp_is_full(endp));
- } else {
- /* There is no more room for a connection, leave
- * everything as it is and return with an error */
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_LIMIT_EXCEEDED));
- return create_err_response(endp, endp, 540, "CRCX", pdata->trans);
- }
- }
-
- /* Check if this endpoint already serves a call, if so, check if the
- * callids match up so that we are sure that this is our call.
- * Do check only if endpoint was (or is by current CRCX) configured
- * to explicitly ignore it ("X-Osmo-IGN: C").
- */
- if (endp->callid &&
- !((endp->x_osmo_ign | hpars->x_osmo_ign) & MGCP_X_OSMO_IGN_CALLID) &&
- mgcp_verify_call_id(endp, hpars->callid)) {
- LOGPENDP(endp, DLMGCP, LOGL_ERROR,
- "CRCX: already seized by other call (%s)\n",
- endp->callid);
- if (trunk->force_realloc)
- /* This is not our call, toss everything by releasing
- * the entire endpoint. (rude!) */
- mgcp_endp_release(endp);
- else {
- /* This is not our call, leave everything as it is and
- * return with an error. */
- rate_ctr_inc(rate_ctr_group_get_ctr(rate_ctrs, MGCP_CRCX_FAIL_UNKNOWN_CALLID));
- return create_err_response(endp, endp, 400, "CRCX", pdata->trans);
- }
- }
+ rc = validate_parsed_crcx(rq);
+ if (rc < 0)
+ return create_err_response(endp, endp, -rc, "CRCX", pdata->trans);
/*******************************************************************
* Allocate and update endpoint and conn.
- * From here on below we start updating endpoing and creating conn:
+ * From here on below we start updating endpoint and creating conn:
*******************************************************************/
+ if (trunk->force_realloc) {
+ /* Check if we are able to accept the creation of another connection */
+ if (mgcp_endp_is_full(endp)) {
+ /* There is no more room for a connection, make some
+ * room by blindly tossing the oldest of the two two
+ * connections */
+ LOGPENDP(endp, DLMGCP, LOGL_ERROR, "CRCX: endpoint full, max. %d connections allowed!\n",
+ endp->type->max_conns);
+ mgcp_endp_free_conn_oldest(endp);
+ OSMO_ASSERT(!mgcp_endp_is_full(endp));
+ }
+
+ /* Check if this endpoint already serves a call and then check if the callids match up */
+ if (endp->callid &&
+ !((endp->x_osmo_ign | hpars->x_osmo_ign) & MGCP_X_OSMO_IGN_CALLID) &&
+ mgcp_verify_call_id(endp, hpars->callid)) {
+ /* This is not our call, toss everything by releasing
+ * the entire endpoint. (rude!) */
+ mgcp_endp_release(endp);
+ }
+ }
+
/* Update endp->x_osmo_ign: */
endp->x_osmo_ign |= hpars->x_osmo_ign;
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