Initial IuUP support using proper FSMs
Related: OS#1937
Depends: libosmocore Change-Id I63ee780b4aa162ea097410b234e73984000c0965
Change-Id: I6694a21480b25ab8f35d375295be6601ce38e31d
diff --git a/src/libosmo-mgcp/mgcp_iuup.c b/src/libosmo-mgcp/mgcp_iuup.c
new file mode 100644
index 0000000..5af481d
--- /dev/null
+++ b/src/libosmo-mgcp/mgcp_iuup.c
@@ -0,0 +1,720 @@
+/*
+ * (C) 2021 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ * All rights not specifically granted under this license are reserved.
+ *
+ * Author: Pau Espin Pedrol
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by the
+ * Free Software Foundation; either version 3 of the License, or (at your
+ * option) any later version.
+ */
+
+#include <stdint.h>
+
+#include <osmocom/core/byteswap.h>
+
+#include <osmocom/gsm/iuup.h>
+
+#include <osmocom/netif/rtp.h>
+#include <osmocom/netif/amr.h>
+
+#include <osmocom/mgcp/mgcp_conn.h>
+#include <osmocom/mgcp/mgcp_iuup.h>
+#include <osmocom/mgcp/mgcp_endp.h>
+#include <osmocom/mgcp/mgcp_codec.h>
+#include <osmocom/mgcp/mgcp_network.h>
+#include <osmocom/mgcp/debug.h>
+
+#define MGW_IUUP_MSGB_SIZE 4096
+
+static const struct osmo_iuup_rnl_config def_configure_req = {
+ .transparent = false,
+ .active = true,
+ .supported_versions_mask = 0x0003,
+ .num_rfci = 0,
+ .num_subflows = 0,
+ .IPTIs_present = false,
+ .t_init = { .t_ms = IUUP_TIMER_INIT_T_DEFAULT, .n_max = IUUP_TIMER_INIT_N_DEFAULT },
+ .t_ta = { .t_ms = IUUP_TIMER_TA_T_DEFAULT, .n_max = IUUP_TIMER_TA_N_DEFAULT },
+ .t_rc = { .t_ms = IUUP_TIMER_RC_T_DEFAULT, .n_max = IUUP_TIMER_RC_N_DEFAULT },
+};
+
+/* Find a destination connection. */
+static struct mgcp_conn *_find_dst_conn(struct mgcp_conn *conn)
+{
+ /* NOTE: This code path runs every time an RTP packet is received. The
+ * function mgcp_find_dst_conn() we use to determine the detination
+ * connection will iterate the connection list inside the endpoint.
+ * Since list iterations are quite costly, we will figure out the
+ * destination only once and use the optional private data pointer of
+ * the connection to cache the destination connection pointer. */
+
+ struct mgcp_conn *conn_dst;
+ if (!conn->priv) {
+ conn_dst = mgcp_find_dst_conn(conn);
+ conn->priv = conn_dst;
+ } else {
+ conn_dst = (struct mgcp_conn *)conn->priv;
+ }
+ return conn_dst;
+}
+
+/* Find RFCI containing all 0 sizes, -1 if not found. irp is an Initialization.ind prim */
+static int _find_rfci_no_data(struct osmo_iuup_rnl_prim *irp)
+{
+ int i;
+ /* Find RFCI containing NO_DATA: */
+ for (i = 0; i < irp->u.status.u.initialization.num_rfci; i++) {
+ int j;
+ bool is_no_data = true;
+ for (j = 0; j < irp->u.status.u.initialization.num_subflows; j++) {
+ if (irp->u.status.u.initialization.subflow_sizes[i][j]) {
+ is_no_data = false;
+ break;
+ }
+ }
+ if (is_no_data) {
+ return i;
+ }
+ }
+ return -1;
+}
+
+/* Lookup RFCI to use for specific AMR codec type. -1 if none found */
+static int8_t _conn_iuup_amr_ft_2_rfci(struct mgcp_conn_rtp *conn_rtp, uint8_t ft)
+{
+ int8_t i;
+ unsigned match_bytes = (unsigned)osmo_amr_bytes(ft);
+ struct osmo_iuup_rnl_prim *irp = conn_rtp->iuup.init_ind;
+ OSMO_ASSERT(irp);
+
+ /* TODO: cache this somehow */
+ for (i = 0; i < irp->u.status.u.initialization.num_rfci; i++) {
+ int j;
+ unsigned num_bits = 0;
+ for (j = 0; j < irp->u.status.u.initialization.num_subflows; j++)
+ num_bits += irp->u.status.u.initialization.subflow_sizes[i][j];
+ if (match_bytes == (num_bits + 7)/8)
+ return i;
+ }
+
+ return -1;
+}
+
+/* Helper function to configure IuUP layer FSM as Init-Passive, based on default config */
+static int _conn_iuup_configure_as_passive(struct mgcp_conn_rtp *conn_rtp)
+{
+ struct osmo_iuup_rnl_prim *irp;
+ int rc;
+
+ conn_rtp->iuup.active_init = false;
+
+ /* Tx CONFIG.req */
+ irp = osmo_iuup_rnl_prim_alloc(conn_rtp->conn, OSMO_IUUP_RNL_CONFIG, PRIM_OP_REQUEST, MGW_IUUP_MSGB_SIZE);
+ irp->u.config = def_configure_req;
+ irp->u.config.active = conn_rtp->iuup.active_init;
+ if ((rc = osmo_iuup_rnl_prim_down(conn_rtp->iuup.iui, irp)) == 0)
+ conn_rtp->iuup.configured = true;
+ else
+ LOG_CONN_RTP(conn_rtp, LOGL_ERROR, "Failed configuring IuUP layer\n");
+ return rc;
+}
+
+/* Helper function to configure IuUP layer FSM as Init-Active, based on received
+ * RNL Status-Init primitive from the sister IuUP connection we will bridge to. */
+static int _conn_iuup_configure_as_active(struct mgcp_conn_rtp *conn_rtp, struct osmo_iuup_rnl_prim *init_ind)
+{
+ struct osmo_iuup_rnl_prim *irp = init_ind;
+ struct osmo_iuup_rnl_prim *irp2;
+ struct msgb *msg;
+ bool prev_output_enabled;
+ int rc;
+
+ conn_rtp->iuup.active_init = true;
+
+ /* Find RFCI containing NO_DATA: */
+ conn_rtp->iuup.rfci_idx_no_data = _find_rfci_no_data(init_ind);
+
+ /* Copy over the rfci_idx_no_data, since we reuse the same subflow set: */
+ msg = msgb_copy_c(conn_rtp->conn, irp->oph.msg, "iuup-init-copy");
+ conn_rtp->iuup.init_ind = (struct osmo_iuup_rnl_prim *)msgb_data(msg);
+ conn_rtp->iuup.init_ind->oph.msg = msg;
+
+ /* Tx CONFIG.req */
+ irp2 = osmo_iuup_rnl_prim_alloc(conn_rtp->conn, OSMO_IUUP_RNL_CONFIG, PRIM_OP_REQUEST, MGW_IUUP_MSGB_SIZE);
+ irp2->u.config.transparent = false;
+ irp2->u.config.active = conn_rtp->iuup.active_init;
+ irp2->u.config.data_pdu_type = irp->u.status.u.initialization.data_pdu_type;
+ irp2->u.config.supported_versions_mask = def_configure_req.supported_versions_mask;
+ irp2->u.config.num_rfci = irp->u.status.u.initialization.num_rfci;
+ irp2->u.config.num_subflows = irp->u.status.u.initialization.num_subflows;
+ memcpy(irp2->u.config.subflow_sizes, irp->u.status.u.initialization.subflow_sizes,
+ IUUP_MAX_RFCIS * IUUP_MAX_SUBFLOWS * sizeof(irp2->u.config.subflow_sizes[0][0]));
+ irp2->u.config.IPTIs_present = irp->u.status.u.initialization.IPTIs_present;
+ if (irp->u.status.u.initialization.IPTIs_present)
+ memcpy(irp2->u.config.IPTIs, irp->u.status.u.initialization.IPTIs,
+ IUUP_MAX_RFCIS * sizeof(irp2->u.config.IPTIs[0]));
+ irp2->u.config.t_init = def_configure_req.t_init;
+ irp2->u.config.t_ta = def_configure_req.t_ta;
+ irp2->u.config.t_rc = def_configure_req.t_rc;
+
+ /* We need to force allowance of RTP containing Init-ACK back: */
+ prev_output_enabled = conn_rtp->end.output_enabled;
+ conn_rtp->end.output_enabled = true;
+
+ if ((rc = osmo_iuup_rnl_prim_down(conn_rtp->iuup.iui, irp2)) == 0)
+ conn_rtp->iuup.configured = true;
+ else
+ LOG_CONN_RTP(conn_rtp, LOGL_ERROR, "Failed configuring IuUP layer\n");
+
+ conn_rtp->end.output_enabled = prev_output_enabled;
+ return rc;
+}
+
+/* Helper function to push an RTP+IuUP pkt up to the IuUP layer FSM through the
+ * TNL primitive interface. */
+static int _conn_iuup_rtp_pl_up(struct mgcp_conn_rtp *conn_rtp, struct msgb *msg)
+{
+ /* Send RTP payload (IuUP) up the stack: */
+ struct osmo_iuup_tnl_prim *itp;
+ int rc;
+
+ msg->l2h = msgb_data(msg) + sizeof(struct rtp_hdr);
+
+ itp = osmo_iuup_tnl_prim_alloc(conn_rtp->conn, OSMO_IUUP_TNL_UNITDATA, PRIM_OP_INDICATION, MGW_IUUP_MSGB_SIZE);
+ itp->oph.msg->l2h = msgb_put(itp->oph.msg, msgb_l2len(msg));
+ memcpy(itp->oph.msg->l2h, msgb_l2(msg), msgb_l2len(msg));
+ if ((rc = osmo_iuup_tnl_prim_up(conn_rtp->iuup.iui, itp)) != 0) {
+ LOG_CONN_RTP(conn_rtp, LOGL_ERROR, "Failed passing IuUP-Init to IuUP layer\n");
+ }
+ return rc;
+}
+
+static int check_rtp_iuup(const struct mgcp_conn_rtp *conn_rtp, struct msgb *msg)
+{
+ size_t min_size = sizeof(struct rtp_hdr);
+ /* Check there's at least 2 bytes of RTP payload (IuUP header). This is
+ ** mainly to avoid 0-byte payload copy cases */
+ if (msgb_length(msg) < sizeof(struct rtp_hdr) + 2) {
+ LOG_CONN_RTP(conn_rtp, LOGL_ERROR, "RTP-IuUP packet too short (%u < %zu)\n",
+ msgb_length(msg), min_size);
+ return -1;
+ }
+ return 0;
+}
+
+/* Bridge received IuUP packet in conn_rtp_src to conn_rtp_dst, an IuUP sister
+ * conn in the endpoint. The function takes ownsership of the irp */
+static int bridge_iuup_to_iuup_peer(struct mgcp_conn_rtp *conn_rtp_src, struct mgcp_conn_rtp *conn_rtp_dst, struct osmo_iuup_rnl_prim *irp)
+{
+ int rc;
+
+ /* If we are not configured and we received bridged data, it means
+ * conn_rtp_src is already configured and INITed, and we can infer
+ * conn_rtp_src is Init-passive (RNC side), so conn_rtp_dst needs to be
+ * configured as INIT-active: */
+ if (!conn_rtp_dst->iuup.configured) {
+ OSMO_ASSERT(conn_rtp_src->iuup.init_ind);
+ rc = _conn_iuup_configure_as_active(conn_rtp_dst, conn_rtp_src->iuup.init_ind);
+ if (rc < 0) {
+ msgb_free(irp->oph.msg);
+ return rc;
+ }
+ }
+
+ /* We simply forward the msg, without freeing it: */
+ talloc_steal(conn_rtp_dst->conn, irp->oph.msg);
+ irp->oph.operation = PRIM_OP_REQUEST;
+ if ((rc = osmo_iuup_rnl_prim_down(conn_rtp_dst->iuup.iui, irp)) != 0)
+ LOG_CONN_RTP(conn_rtp_dst, LOGL_ERROR, "Failed Tx data down to IuUP layer\n");
+ return rc;
+}
+
+/* Bridge received IuUP packet in conn_rtp_src to conn_rtp_dst, an RTP (no IuUP)
+ * sister conn in the endpoint. The function takes ownsership of the irp */
+static int bridge_iuup_to_rtp_peer(struct mgcp_conn_rtp *conn_rtp_src, struct mgcp_conn_rtp *conn_rtp_dst, struct osmo_iuup_rnl_prim *irp)
+{
+ /* FIXME: We probably need transcoding here?! Or at least look up AMR modes and translate to related RFCI */
+ uint8_t frame_nr = irp->u.data.frame_nr;
+ uint8_t fqc = irp->u.data.fqc;
+ struct msgb *msg = irp->oph.msg;
+ ssize_t amr_length = 0;
+ int ft;
+ uint8_t *amr_data;
+ struct rtp_hdr *rtp_hdr;
+ struct amr_hdr *amr_hdr;
+ int rc;
+
+ ft = osmo_amr_bytes_to_ft(msgb_l3len(msg));
+ if (ft < 0) {
+ LOGPCONN(conn_rtp_src->conn, DRTP, LOGL_ERROR,
+ "Unknown AMR format for size %u\n", msgb_l3len(msg));
+ msgb_free(msg);
+ return ft;
+ }
+ msgb_pull_to_l3(msg);
+ LOGP(DLMGCP, LOGL_DEBUG, "Convert Iuup -> AMR: ft %d, len %d\n", ft, msgb_l3len(msg));
+
+ if (mgcp_codec_amr_is_octet_aligned(conn_rtp_dst->end.codec)) {
+ amr_hdr = (struct amr_hdr *) msgb_push(msg, sizeof(struct amr_hdr));
+ amr_hdr->cmr = 15; /* no change */
+ amr_hdr->f = 0;
+ amr_hdr->q = !fqc;
+ amr_hdr->ft = ft & 0xff;
+ amr_hdr->pad1 = 0;
+ amr_hdr->pad2 = 0;
+ } else {
+ OSMO_ASSERT(msgb_tailroom(msg) >= 2);
+ msgb_put(msg, 2);
+ osmo_amr_iuup_to_bwe(msgb_data(msg), msgb_length(msg) - 2, msgb_length(msg) + 2);
+ /* fill bwe header */
+ amr_data = msgb_data(msg);
+ /* CMR no change | follow bit | ft (3 of 4 bits) */
+ amr_data[0] = 15 << 4 | (0 << 3) | (ft >> 1);
+ amr_data[1] |= ((ft & 0x1) << 7) | (((!fqc) & 0x1) << 6);
+ amr_length = (osmo_amr_bits(ft) + 10 + 7) / 8;
+ msgb_trim(msg, amr_length);
+ }
+ rtp_hdr = (struct rtp_hdr *) msgb_push(msg, sizeof(*rtp_hdr));
+ *rtp_hdr = (struct rtp_hdr){
+ .csrc_count = 0,
+ .extension = 0,
+ .padding = 0,
+ .version = 0,
+ .payload_type = conn_rtp_dst->end.codec->payload_type,
+ .marker = 0,
+ .sequence = frame_nr,
+ .timestamp = 0,
+ .ssrc = 0
+ };
+
+ rc = mgcp_send(conn_rtp_dst->conn->endp, true, NULL, msg, conn_rtp_src, conn_rtp_dst);
+ msgb_free(msg);
+ return rc;
+}
+
+/* Handle RNL Data primitive received from the IuUP layer FSM: Bridge it to the
+ * sister connection in the endpoint: */
+static int _conn_iuup_rx_rnl_data(struct mgcp_conn_rtp *conn_rtp_src, struct osmo_iuup_rnl_prim *irp)
+{
+ struct mgcp_conn *conn_dst;
+ struct mgcp_conn_rtp *conn_rtp_dst;
+ int rc;
+
+ conn_dst = _find_dst_conn(conn_rtp_src->conn);
+
+ /* There is no destination conn, stop here */
+ if (!conn_dst) {
+ LOGPCONN(conn_rtp_src->conn, DRTP, LOGL_DEBUG,
+ "no connection to forward an incoming IuUP payload to\n");
+ rc = -1;
+ goto free_ret;
+ }
+
+ /* The destination conn is not an RTP/IuUP connection */
+ if (conn_dst->type != MGCP_CONN_TYPE_RTP) {
+ LOGPCONN(conn_rtp_src->conn, DRTP, LOGL_ERROR,
+ "unable to find suitable destination conn\n");
+ rc = -1;
+ goto free_ret;
+ }
+ conn_rtp_dst = &conn_dst->u.rtp;
+
+ switch (conn_rtp_dst->type) {
+ case MGCP_RTP_IUUP:
+ return bridge_iuup_to_iuup_peer(conn_rtp_src, conn_rtp_dst, irp);
+ case MGCP_RTP_DEFAULT:
+ return bridge_iuup_to_rtp_peer(conn_rtp_src, conn_rtp_dst, irp);
+ case MGCP_OSMUX_BSC:
+ case MGCP_OSMUX_BSC_NAT:
+ default:
+ LOGPCONN(conn_rtp_src->conn, DRTP, LOGL_ERROR,
+ "Forward of IuUP payload to RTP connection type %u not supported!\n",
+ conn_rtp_dst->type);
+ rc = 0;
+ }
+
+free_ret:
+ msgb_free(irp->oph.msg);
+ return rc;
+}
+
+/* Handle RNL Status-Init primitive received from the IuUP layer FSM.
+ * Potentially configure sister conn as IuUP Init-Active: */
+static int _conn_iuup_rx_rnl_status_init(struct mgcp_conn_rtp *conn_rtp_src, struct osmo_iuup_rnl_prim *irp)
+{
+ struct mgcp_conn *conn_dst;
+ struct mgcp_conn_rtp *conn_rtp_dst;
+ int rc = 0;
+ struct msgb *msg;
+
+ /* Find RFCI containing NO_DATA: */
+ conn_rtp_src->iuup.rfci_idx_no_data = _find_rfci_no_data(irp);
+
+ msg = msgb_copy_c(conn_rtp_src->conn, irp->oph.msg, "iuup-init-copy");
+ conn_rtp_src->iuup.init_ind = (struct osmo_iuup_rnl_prim *)msgb_data(msg);
+ conn_rtp_src->iuup.init_ind->oph.msg = msg;
+
+ conn_dst = _find_dst_conn(conn_rtp_src->conn);
+ /* If not yet there, peer will potentially be IuUP-Initialized later
+ * when we attempt to bridge audio towards it. See bridge_iuup_to_iuup_peer() */
+ if (!conn_dst)
+ return 0;
+ conn_rtp_dst = &conn_dst->u.rtp;
+ if (!mgcp_conn_rtp_is_iuup(conn_rtp_dst))
+ return 0; /* Nothing to do */
+
+ /* We received IuUP parameters on the peer (RNC), Init actively this conn (against CN): */
+ if (!conn_rtp_dst->iuup.configured)
+ rc = _conn_iuup_configure_as_active(conn_rtp_dst, irp);
+
+ return rc;
+}
+
+/* Handle RNL Status primitives received from the IuUP layer FSM: */
+static int _conn_iuup_rx_rnl_status(struct mgcp_conn_rtp *conn_rtp_src, struct osmo_iuup_rnl_prim *irp)
+{
+ int rc;
+
+ switch (irp->u.status.procedure) {
+ case IUUP_PROC_INIT:
+ rc = _conn_iuup_rx_rnl_status_init(conn_rtp_src, irp);
+ break;
+ case IUUP_PROC_RATE_CTRL:
+ case IUUP_PROC_TIME_ALIGN:
+ case IUUP_PROC_ERR_EVENT:
+ default:
+ LOG_CONN_RTP(conn_rtp_src, LOGL_ERROR,
+ "Received IuUP RNL STATUS procedure type %u not handled\n",
+ irp->u.status.procedure);
+ rc = 0;
+ }
+
+ return rc;
+}
+
+/* Received RNL primitive from the IuUP layer FSM containing IuUP Status or
+ * data. Continue pushing it up the stack, either IuUP Status or Data: */
+static int _conn_iuup_user_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
+{
+ struct mgcp_conn_rtp *conn_rtp_src = ctx;
+ struct osmo_iuup_rnl_prim *irp = (struct osmo_iuup_rnl_prim *)oph;
+ struct msgb *msg = oph->msg;
+ int rc;
+
+ switch (OSMO_PRIM_HDR(&irp->oph)) {
+ case OSMO_PRIM(OSMO_IUUP_RNL_DATA, PRIM_OP_INDICATION):
+ /* we pass ownsership of msg here: */
+ rc = _conn_iuup_rx_rnl_data(conn_rtp_src, irp);
+ break;
+ case OSMO_PRIM(OSMO_IUUP_RNL_STATUS, PRIM_OP_INDICATION):
+ rc = _conn_iuup_rx_rnl_status(conn_rtp_src, irp);
+ msgb_free(msg);
+ break;
+ default:
+ msgb_free(msg);
+ OSMO_ASSERT(false);
+ }
+
+ return rc;
+}
+
+/*! Send |RTP+IuUP| data down the stack of the specified destination connection.
+ * \param[in] endp associated endpoint (for configuration, logging).
+ * \param[in] buf buffer that contains the |RTP+IuUP| data.
+ * \param[in] len length of the buffer that contains the |RTP+IuUP| data.
+ * \param[in] conn_src associated source connection.
+ * \param[in] conn_dst associated destination connection.
+ * \returns 0 on success, -1 on ERROR. */
+static int mgcp_send_iuup(struct mgcp_endpoint *endp, struct msgb *msg,
+ struct mgcp_conn_rtp *conn_src, struct mgcp_conn_rtp *conn_dst)
+{
+ /*! When no destination connection is available (e.g. when only one
+ * connection in loopback mode exists), then the source connection
+ * shall be specified as destination connection */
+
+ struct mgcp_rtp_end *rtp_end;
+ struct mgcp_rtp_state *rtp_state;
+ char ipbuf[INET6_ADDRSTRLEN];
+ struct rtp_hdr *hdr = (struct rtp_hdr *)msgb_data(msg);
+ int buflen = msgb_length(msg);
+ char *dest_name;
+ int len;
+
+ OSMO_ASSERT(conn_src);
+ OSMO_ASSERT(conn_dst);
+
+ LOGPENDP(endp, DRTP, LOGL_DEBUG, "delivering IuUP packet...\n");
+
+ /* Note: In case of loopback configuration, both, the source and the
+ * destination will point to the same connection. */
+ rtp_end = &conn_dst->end;
+ rtp_state = &conn_src->state;
+ dest_name = conn_dst->conn->name;
+
+ /* Ensure we have an alternative SSRC in case we need it, see also
+ * gen_rtp_header() */
+ if (rtp_state->alt_rtp_tx_ssrc == 0)
+ rtp_state->alt_rtp_tx_ssrc = rand();
+
+ if (!rtp_end->output_enabled) {
+ rtpconn_rate_ctr_add(conn_dst, endp, RTP_DROPPED_PACKETS_CTR, 1);
+ LOGPENDP(endp, DRTP, LOGL_DEBUG,
+ "output disabled, drop to %s %s "
+ "rtp_port:%u rtcp_port:%u\n",
+ dest_name,
+ osmo_sockaddr_ntop(&rtp_end->addr.u.sa, ipbuf),
+ ntohs(rtp_end->rtp_port), ntohs(rtp_end->rtcp_port)
+ );
+ return 0;
+ }
+
+ /* Specs say, in IuUP, the RTP seqnum and timestamp should actually be
+ * ignored by the receiver, but still it's useful for debug purposes
+ * to set it. Moreover, it seems ip.access nano3g produces much worse
+ * audio output on the air side if timestamp is not set properly. */
+ hdr->timestamp = osmo_htonl(mgcp_get_current_ts(rtp_end->codec->rate));
+ hdr->sequence = osmo_htons(rtp_state->alt_rtp_tx_sequence);
+ hdr->ssrc = rtp_state->alt_rtp_tx_ssrc;
+
+ LOGPENDP(endp, DRTP, LOGL_DEBUG,
+ "process/send IuUP to %s %s rtp_port:%u rtcp_port:%u\n",
+ dest_name, osmo_sockaddr_ntop(&rtp_end->addr.u.sa, ipbuf),
+ ntohs(rtp_end->rtp_port), ntohs(rtp_end->rtcp_port));
+
+ /* Forward a copy of the RTP data to a debug ip/port */
+ forward_data_tap(rtp_end->rtp.fd, &conn_src->tap_out,
+ msg);
+
+ len = mgcp_udp_send(rtp_end->rtp.fd, &rtp_end->addr, rtp_end->rtp_port,
+ (char *)hdr, buflen);
+
+ if (len <= 0)
+ return len;
+
+ rtpconn_rate_ctr_add(conn_dst, endp, RTP_PACKETS_TX_CTR, 1);
+ rtpconn_rate_ctr_add(conn_dst, endp, RTP_OCTETS_TX_CTR, len);
+ rtp_state->alt_rtp_tx_sequence++;
+
+ return len;
+}
+
+/* Received TNL primitive from IuUP layer FSM, transmit it further down to the
+ * socket towards destination peer. */
+static int _conn_iuup_transport_prim_cb(struct osmo_prim_hdr *oph, void *ctx)
+{
+ struct mgcp_conn_rtp *conn_rtp_dst = ctx;
+ struct mgcp_conn *conn_dst = conn_rtp_dst->conn;
+ struct osmo_iuup_tnl_prim *itp = (struct osmo_iuup_tnl_prim *)oph;
+ struct mgcp_conn *conn_src;
+ struct msgb *msg;
+ struct rtp_hdr *rtph;
+
+ OSMO_ASSERT(OSMO_PRIM_HDR(&itp->oph) == OSMO_PRIM(OSMO_IUUP_TNL_UNITDATA, PRIM_OP_REQUEST));
+
+ msg = oph->msg;
+ talloc_steal(conn_rtp_dst->conn, msg);
+
+ msgb_pull_to_l2(msg);
+ rtph = (struct rtp_hdr *)msgb_push(msg, sizeof(*rtph));
+ /* TODO: fill rtph properly: */
+ *rtph = (struct rtp_hdr){
+ .csrc_count = 0,
+ .extension = 0,
+ .padding = 0,
+ .version = 2,
+ .payload_type = conn_rtp_dst->end.codec->payload_type,
+ .marker = 0,
+ .sequence = 0,
+ .timestamp = 0,
+ .ssrc = 0
+ };
+
+ /* The destination of the destination conn is the source conn, right? */
+ conn_src = _find_dst_conn(conn_dst);
+ if (!conn_src) {
+ LOG_CONN_RTP(conn_rtp_dst, LOGL_NOTICE,
+ "Couldn't find source conn for IuUP dst conn\n");
+ /* If there's no sister connection we are either still
+ * initializing (so we want to send back Init (ACK)), or we are
+ * probably in loopback mode anyway, so use dst as src. */
+ conn_src = conn_dst;
+ }
+
+ return mgcp_send_iuup(conn_dst->endp, msg, &conn_src->u.rtp, conn_rtp_dst);
+}
+
+/* Used to upgrade a regular RTP connection (MGCP_RTP_DEFAULT) to become a IuUP
+ * connection (MGCP_RTP_IUUP) */
+int mgcp_conn_iuup_init(struct mgcp_conn_rtp *conn_rtp)
+{
+ conn_rtp->type = MGCP_RTP_IUUP;
+ conn_rtp->iuup.iui = osmo_iuup_instance_alloc(conn_rtp->conn, conn_rtp->conn->id);
+ OSMO_ASSERT(conn_rtp->iuup.iui);
+ osmo_iuup_instance_set_user_prim_cb(conn_rtp->iuup.iui, _conn_iuup_user_prim_cb, conn_rtp);
+ osmo_iuup_instance_set_transport_prim_cb(conn_rtp->iuup.iui, _conn_iuup_transport_prim_cb, conn_rtp);
+ conn_rtp->iuup.rfci_idx_no_data = -1;
+ return 0;
+}
+
+/* Cleanup specific IuUP connection (MGCP_RTP_IUUP) state, allocated by mgcp_conn_iuup_init() */
+void mgcp_conn_iuup_cleanup(struct mgcp_conn_rtp *conn_rtp)
+{
+ osmo_iuup_instance_free(conn_rtp->iuup.iui);
+ conn_rtp->iuup.iui = NULL;
+}
+
+/* Received RTP+IuUP pkt from socket of conn_rtp_src, build a TNL primitive to
+ * push it further up the stack to the IuUP layer FSM to handle and/or bridge it */
+int mgcp_conn_iuup_dispatch_rtp(struct msgb *msg)
+{
+ struct osmo_rtp_msg_ctx *mc = OSMO_RTP_MSG_CTX(msg);
+ struct mgcp_conn_rtp *conn_rtp_src = mc->conn_src;
+ int rc = 0;
+ bool force_output_enabled = false;
+ bool prev_output_enabled;
+ struct osmo_sockaddr prev_rem_addr;
+ uint16_t prev_rem_rtp_port;
+
+ OSMO_ASSERT(mgcp_conn_rtp_is_iuup(conn_rtp_src));
+
+ if ((rc = check_rtp_iuup(conn_rtp_src, msg)) < 0)
+ goto free_ret;
+
+ if (!conn_rtp_src->iuup.configured) {
+ /* We received the first message without sending any, the peer is the active side (RNC). */
+ rc = _conn_iuup_configure_as_passive(conn_rtp_src);
+ if (rc < 0)
+ goto free_ret;
+ /* We need to force allowance of RTP containing Init-ACK back: */
+ prev_output_enabled = conn_rtp_src->end.output_enabled;
+ conn_rtp_src->end.output_enabled = true;
+ force_output_enabled = true;
+ /* Fill in the peer address so that we can send Init-ACK back: */
+ prev_rem_addr = conn_rtp_src->end.addr;
+ prev_rem_rtp_port = conn_rtp_src->end.rtp_port;
+ conn_rtp_src->end.addr = *mc->from_addr;
+ conn_rtp_src->end.rtp_port = htons(osmo_sockaddr_port(&mc->from_addr->u.sa));
+ }
+
+ rc = _conn_iuup_rtp_pl_up(conn_rtp_src, msg);
+
+ if (force_output_enabled) {
+ conn_rtp_src->end.output_enabled = prev_output_enabled;
+ conn_rtp_src->end.addr = prev_rem_addr;
+ conn_rtp_src->end.rtp_port = prev_rem_rtp_port;
+ }
+
+ return rc;
+free_ret:
+ msgb_free(msg);
+ return rc;
+}
+
+/* Build IuUP RNL Data primitive from msg containing an incoming RTP pkt from
+ * peer and send it down the IuUP layer towards the destination as IuUP/RTP: */
+int mgcp_conn_iuup_send_rtp(struct mgcp_conn_rtp *conn_src_rtp, struct mgcp_conn_rtp *conn_dest_rtp, struct msgb *msg)
+{
+ struct osmo_iuup_rnl_prim *irp;
+ struct rtp_hdr *rtph;
+ int rc = -1;
+ int iuup_length = 0;
+ int8_t rfci;
+
+ /* Tx RNL-DATA.req */
+ rtph = (struct rtp_hdr *)msgb_data(msg);
+ msgb_pull(msg, sizeof(*rtph));
+
+ /* FIXME: validate amr packets */
+ irp = osmo_iuup_rnl_prim_alloc(conn_dest_rtp->conn, OSMO_IUUP_RNL_DATA, PRIM_OP_REQUEST, MGW_IUUP_MSGB_SIZE);
+ irp->u.data.frame_nr = htons(rtph->sequence) % 16;
+
+ /* TODO: CMR handling & multiple frames handling */
+
+ if (strcmp(conn_src_rtp->end.codec->subtype_name, "AMR") != 0) {
+ LOG_CONN_RTP(conn_src_rtp, LOGL_ERROR,
+ "Bridge RTP=>IuUP: Bridging src codec %s to IuUP AMR not supported\n",
+ conn_src_rtp->end.codec->subtype_name);
+ goto free_ret;
+ }
+ if (mgcp_codec_amr_is_octet_aligned(conn_src_rtp->end.codec)) {
+ struct amr_hdr *amr_hdr = (struct amr_hdr *) msgb_data(msg);
+ if (msgb_length(msg) < (sizeof(*amr_hdr))) {
+ LOG_CONN_RTP(conn_src_rtp, LOGL_NOTICE,
+ "Bridge RTP=>IuUP: too short for AMR OA hdr (%u)\n", msgb_length(msg));
+ goto free_ret;
+ }
+ if (amr_hdr->ft >= AMR_FT_MAX) {
+ LOG_CONN_RTP(conn_src_rtp, LOGL_NOTICE, "Bridge RTP=>IuUP: wrong AMR OA ft=%u\n", amr_hdr->ft);
+ goto free_ret;
+ }
+ if ((rfci = _conn_iuup_amr_ft_2_rfci(conn_dest_rtp, amr_hdr->ft)) < 0) {
+ LOG_CONN_RTP(conn_dest_rtp, LOGL_NOTICE, "Bridge RTP=>IuUP: No RFCI found for AMR OA ft=%u\n", amr_hdr->ft);
+ goto free_ret;
+ }
+ irp->u.data.fqc = amr_hdr->q;
+ irp->u.data.rfci = rfci;
+ msgb_pull(msg, 2);
+ } else {
+ uint8_t *amr_bwe_hdr = (uint8_t *) msgb_data(msg);
+ int8_t ft;
+ if (msgb_length(msg) < 2) {
+ LOG_CONN_RTP(conn_src_rtp, LOGL_NOTICE,
+ "Bridge RTP=>IuUP: too short for AMR BE hdr (%u)\n", msgb_length(msg));
+ goto free_ret;
+ }
+ ft = ((amr_bwe_hdr[0] & 0x07) << 1) | ((amr_bwe_hdr[1] & 0x80) >> 7);
+ if (ft >= AMR_FT_MAX) {
+ LOG_CONN_RTP(conn_src_rtp, LOGL_NOTICE, "Bridge RTP=>IuUP: wrong AMR BE ft=%u\n", ft);
+ goto free_ret;
+ }
+ if ((rfci = _conn_iuup_amr_ft_2_rfci(conn_dest_rtp, ft)) < 0) {
+ LOG_CONN_RTP(conn_dest_rtp, LOGL_NOTICE, "Bridge RTP=>IuUP: No RFCI found for AMR BE ft=%u\n", ft);
+ goto free_ret;
+ }
+ irp->u.data.fqc = ((amr_bwe_hdr[1] & 0x40) >> 6);
+ irp->u.data.rfci = rfci;
+ rc = iuup_length = osmo_amr_bwe_to_iuup(msgb_data(msg), msgb_length(msg));
+ if (rc < 0) {
+ LOG_CONN_RTP(conn_dest_rtp, LOGL_ERROR, "Bridge RTP=>IuUP: Failed convert the RTP/AMR to IuUP payload\n");
+ return rc;
+ }
+ msgb_trim(msg, iuup_length);
+ }
+
+ irp->oph.msg->l3h = msgb_put(irp->oph.msg, msgb_length(msg));
+ memcpy(irp->oph.msg->l3h, msgb_data(msg), msgb_length(msg));
+ if ((rc = osmo_iuup_rnl_prim_down(conn_dest_rtp->iuup.iui, irp)) != 0)
+ LOG_CONN_RTP(conn_dest_rtp, LOGL_ERROR, "Bridge RTP=>IuUP: Failed Tx RTP payload down the IuUP layer\n");
+ return rc;
+
+free_ret:
+ msgb_free(irp->oph.msg);
+ return -1;
+}
+
+/* Build IuUP RNL Data primitive from msg containing dummy content and send it
+ * down the IuUP layer towards the destination as IuUP/RTP: */
+int mgcp_conn_iuup_send_dummy(struct mgcp_conn_rtp *conn_rtp)
+{
+ struct osmo_iuup_rnl_prim *irp;
+ int rc;
+
+ if (conn_rtp->iuup.rfci_idx_no_data == -1) {
+ LOG_CONN_RTP(conn_rtp, LOGL_NOTICE, "No RFCI NO_DATA found, unable to send dummy packet\n");
+ return -ENOTSUP;
+ }
+
+ irp = osmo_iuup_rnl_prim_alloc(conn_rtp->conn, OSMO_IUUP_RNL_DATA, PRIM_OP_REQUEST, MGW_IUUP_MSGB_SIZE);
+ irp->u.data.frame_nr = 0;
+ irp->u.data.fqc = IUUP_FQC_FRAME_GOOD;
+ irp->u.data.rfci = conn_rtp->iuup.rfci_idx_no_data;
+ irp->oph.msg->l3h = irp->oph.msg->tail;
+ if ((rc = osmo_iuup_rnl_prim_down(conn_rtp->iuup.iui, irp)) != 0) {
+ LOG_CONN_RTP(conn_rtp, LOGL_ERROR, "Failed Tx RTP dummy payload down the IuUP layer\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}