30 Mar
2023
30 Mar
'23
6:29 p.m.
neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-mgw/+/32163
)
Change subject: client: allow passing and receiving full SDP to/from MGW
......................................................................
client: allow passing and receiving full SDP to/from MGW
Clients can continue to use the current way of providing the information
contained in the SDP part.
A client may also decide to directly provide an SDP string. That may be
useful to send a list of payload types with mixed fmtp (e.g. two
entries, one for AMR OA and one for AMR BE) or any other custom SDP that
is not possible to be represented with the previous structure of struct
mgcp_conn_peer:
struct sdp_msg sdp = {};
sdp_audio_codecs_add(&sdp.audio_codecs, 96, "AMR", 8000,
"octet-align=1");
sdp_audio_codecs_add(&sdp.audio_codecs, 97, "AMR", 8000,
"octet-align=0");
struct mgcp_conn_peer verb_info = { ... };
sdp_msg_to_sdp_str_buf(verb_info.sdp, sizeof(verb_info.sdp), &sdp);
osmo_mgcpc_ep_ci_request(my_ci, MGCP_VERB_MDCX, &verb_info,...);
(TODO: sdp_msg, sdp_audio_codecs_add() and sdp_msg_to_sdp_str_buf() so
far only exists in osmo-msc.git)
If no SDP is present in the passed verb_info, the SDP part is composed
as before from the mgcp_conn_peer members addr, port, ptime, ptmap,
param. If an SDP string is present in the passed verb_info, ignore the
data in the individual members, and directly pass the given SDP string
instead -- the caller does not need to pass both the individual members
and SDP, either one suffices.
A client can read the full SDP response from the MGW, again for example
to accurately parse a list with mixed fmtp for AMR like above, like
this:
/* Handling successful event after osmo_mgcpc_ep_ci_request(my_fi, my_notify_event): */
const struct mgcp_conn_peer *response_info = osmo_mgcpc_ep_ci_get_rtp_info(ci);
struct sdp_msg sdp;
sdp_msg_from_sdp_str(&sdp, response_info->sdp);
for (int i = 0; i < sdp.audio_codecs.count; i++)
printf("PT %u = %s %s",
sdp.audio_codecs.codec[i].payload_type,
sdp.audio_codecs.codec[i].subtype_name,
sdp.audio_codecs.codec[i].fmtp);
Related: OS#5723
Change-Id: Ib26b4d24546a9a9af65d4313fdf87cdeff9cbc22
---
M include/osmocom/mgcp_client/mgcp_client.h
M include/osmocom/mgcp_client/mgcp_client_fsm.h
M src/libosmo-mgcp-client/mgcp_client.c
M src/libosmo-mgcp-client/mgcp_client_fsm.c
4 files changed, 83 insertions(+), 2 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-mgw refs/changes/63/32163/1
diff --git a/include/osmocom/mgcp_client/mgcp_client.h
b/include/osmocom/mgcp_client/mgcp_client.h
index 0fb5dee..c185971 100644
--- a/include/osmocom/mgcp_client/mgcp_client.h
+++ b/include/osmocom/mgcp_client/mgcp_client.h
@@ -83,6 +83,7 @@
};
struct mgcp_response {
+ /* The complete MGCP + SDP response. See also 'sdp' below. */
char *body;
struct mgcp_response_head head;
uint16_t audio_port;
@@ -92,6 +93,8 @@
unsigned int codecs_len;
struct ptmap ptmap[MGCP_MAX_CODECS];
unsigned int ptmap_len;
+ /* Start of the SDP part of 'body'. */
+ char *sdp;
};
enum mgcp_verb {
@@ -131,6 +134,8 @@
int x_osmo_osmux_cid; /* -1 is wildcard */
bool param_present;
struct mgcp_codec_param param;
+
+ char sdp[1024];
};
void mgcp_client_conf_init(struct mgcp_client_conf *conf);
diff --git a/include/osmocom/mgcp_client/mgcp_client_fsm.h
b/include/osmocom/mgcp_client/mgcp_client_fsm.h
index ade4f49..de68e70 100644
--- a/include/osmocom/mgcp_client/mgcp_client_fsm.h
+++ b/include/osmocom/mgcp_client/mgcp_client_fsm.h
@@ -61,6 +61,8 @@
* mgcp_common.h */
bool param_present;
struct mgcp_codec_param param;
+
+ char sdp[1024];
};
struct osmo_fsm_inst *mgcp_conn_create(struct mgcp_client *mgcp, struct osmo_fsm_inst
*parent_fi, uint32_t parent_term_evt,
diff --git a/src/libosmo-mgcp-client/mgcp_client.c
b/src/libosmo-mgcp-client/mgcp_client.c
index fb4c17a..85421a2 100644
--- a/src/libosmo-mgcp-client/mgcp_client.c
+++ b/src/libosmo-mgcp-client/mgcp_client.c
@@ -493,6 +493,7 @@
rc = 0;
goto exit;
}
+ r->sdp = data_ptr;
/* data_ptr now points to the beginning of the section-end-marker;
for_each_non_empty_line()
* skips any \r and \n characters for free, so we don't need to skip the marker. */
@@ -1183,6 +1184,13 @@
/* Add separator to mark the beginning of the SDP block */
MSGB_PRINTF_OR_RET(msg, "\r\n");
+ if (mgcp_msg->sdp[0] != '\0') {
+ /* The caller provided a full SDP string, no need to compose SDP. */
+ MSGB_PRINTF_OR_RET(msg, "%s", mgcp_msg->sdp);
+ return 0;
+ }
+ /* The caller did not provide a full SDP section, compose SDP string from the mgcp_msg
members. */
+
/* Add SDP protocol version */
MSGB_PRINTF_OR_RET(msg, "v=0\r\n");
@@ -1365,8 +1373,9 @@
/* Using SDP makes sense when a valid IP/Port combination is specifiec,
* if we do not know this information yet, we fall back to LCO */
- if (mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_IP
- && mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_PORT)
+ if (((mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_IP)
+ && (mgcp_msg->presence & MGCP_MSG_PRESENCE_AUDIO_PORT))
+ || mgcp_msg->sdp[0] != '\0')
use_sdp = true;
/* Add local connection options (LCO) */
diff --git a/src/libosmo-mgcp-client/mgcp_client_fsm.c
b/src/libosmo-mgcp-client/mgcp_client_fsm.c
index 660f0ad..4a33df5 100644
--- a/src/libosmo-mgcp-client/mgcp_client_fsm.c
+++ b/src/libosmo-mgcp-client/mgcp_client_fsm.c
@@ -140,6 +140,9 @@
mgcp_msg->audio_ip = info->addr;
mgcp_msg->audio_port = info->port;
mgcp_msg->conn_mode = MGCP_CONN_RECV_SEND;
+
+ if (info->sdp[0] != '\0')
+ OSMO_STRLCPY_ARRAY(mgcp_msg->sdp, info->sdp);
}
static void set_conn_mode(struct mgcp_msg *mgcp_msg, struct mgcp_conn_peer *peer)
@@ -179,6 +182,9 @@
mgcp_msg.presence |= MGCP_MSG_PRESENCE_X_OSMO_OSMUX_CID;
}
+ if (mgcp_ctx->conn_peer_local.sdp[0] != '\0')
+ OSMO_STRLCPY_ARRAY(mgcp_msg.sdp, mgcp_ctx->conn_peer_local.sdp);
+
/* Note: We take the endpoint and the call_id from the remote
* connection info, because we can be confident that the
* information there is valid. For the local info, we explicitly
@@ -319,6 +325,9 @@
return;
}
+ if (r->sdp && r->sdp[0] != '\0')
+ OSMO_STRLCPY_ARRAY(mgcp_ctx->conn_peer_remote.sdp, r->sdp);
+
mgcp_ctx->conn_peer_remote.call_id = mgcp_ctx->conn_peer_local.call_id;
osmo_fsm_inst_dispatch(fi, EV_CRCX_RESP, mgcp_ctx);
@@ -426,6 +435,9 @@
osmo_strlcpy(mgcp_ctx->conn_peer_remote.addr, r->audio_ip,
sizeof(mgcp_ctx->conn_peer_remote.addr));
mgcp_ctx->conn_peer_remote.port = r->audio_port;
+ if (r->sdp && r->sdp[0] != '\0')
+ OSMO_STRLCPY_ARRAY(mgcp_ctx->conn_peer_remote.sdp, r->sdp);
+
osmo_fsm_inst_dispatch(fi, EV_MDCX_RESP, mgcp_ctx);
}
--
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Gerrit-Project: osmo-mgw
Gerrit-Branch: master
Gerrit-Change-Id: Ib26b4d24546a9a9af65d4313fdf87cdeff9cbc22
Gerrit-Change-Number: 32163
Gerrit-PatchSet: 1
Gerrit-Owner: neels <nhofmeyr(a)sysmocom.de>
Gerrit-MessageType: newchange