| /* A Media Gateway Control Protocol Media Gateway: RFC 3435 */ |
| /* IuUP Core Network side protocol handling, minimal implementation */ |
| |
| /* |
| * (C) 2018 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Neels Hofmeyr <neels@hofmeyr.de> |
| * |
| * 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. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU Affero General Public License for more details. |
| * |
| * You should have received a copy of the GNU Affero General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| * |
| */ |
| |
| #include <talloc.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <arpa/inet.h> |
| |
| #include <osmocom/core/utils.h> |
| #include <osmocom/core/logging.h> |
| #include <osmocom/core/msgb.h> |
| |
| #include <osmocom/netif/rtp.h> |
| |
| #include <osmocom/mgcp/iuup_cn_node.h> |
| #include <osmocom/mgcp/iuup_protocol.h> |
| |
| #include <osmocom/mgcp/debug.h> |
| |
| #define LOG_IUUP_CN(cn, level, fmt, args...) \ |
| LOGP(DIUUP, level, "(%s) " fmt, (cn)->name, ## args) |
| |
| struct osmo_iuup_cn { |
| struct osmo_iuup_cn_cfg cfg; |
| char *name; |
| uint8_t next_frame_nr; |
| int rtp_payload_type; |
| }; |
| |
| struct osmo_iuup_cn *osmo_iuup_cn_init(void *ctx, struct osmo_iuup_cn_cfg *cfg, |
| const char *name_fmt, ...) |
| { |
| va_list ap; |
| struct osmo_iuup_cn *cn = talloc_zero(ctx, struct osmo_iuup_cn); |
| OSMO_ASSERT(cn); |
| |
| cn->cfg = *cfg; |
| |
| if (!name_fmt) |
| name_fmt = "-"; |
| |
| va_start(ap, name_fmt); |
| cn->name = talloc_vasprintf(cn, name_fmt, ap); |
| va_end(ap); |
| |
| LOGP(DIUUP, LOGL_INFO, "(%s) Initializing IuUP node\n", cn->name); |
| |
| if (!osmo_identifier_valid(cn->name)) { |
| LOGP(DIUUP, LOGL_ERROR, "Attempting to set illegal id for IuUP CN instance: %s\n", |
| osmo_quote_str(cn->name, -1)); |
| talloc_free(cn); |
| return NULL; |
| } |
| |
| return cn; |
| } |
| |
| void osmo_iuup_cn_free(struct osmo_iuup_cn *cn) |
| { |
| talloc_free(cn); |
| } |
| |
| static int rx_data(struct osmo_iuup_cn *cn, struct msgb *pdu, |
| struct osmo_iuup_hdr_data *hdr) |
| { |
| /* Remove the IuUP bit from the middle of the buffer by writing the RTP header forward. */ |
| /* And append AMR 12.2k header "0xf03c". - AD HOC fix */ |
| unsigned int pre_hdr_len = ((uint8_t*)hdr) - pdu->data; |
| memmove(pdu->data + sizeof(*hdr) - 2, pdu->data, pre_hdr_len); |
| ((uint8_t*)hdr)[2] = 0xf0; |
| ((uint8_t*)hdr)[3] = 0x3c; |
| msgb_pull(pdu, sizeof(*hdr) - 2); |
| |
| LOGP(DIUUP, LOGL_DEBUG, "(%s) IuUP stripping IuUP header from RTP data\n", cn->name); |
| cn->cfg.rx_payload(pdu, cn->cfg.node_priv); |
| |
| return 0; |
| } |
| |
| static int tx_init_ack(struct osmo_iuup_cn *cn, struct msgb *src_pdu) |
| { |
| /* Send Initialization Ack PDU back to the sender */ |
| int rc; |
| struct msgb *ack = msgb_alloc(4096, "IuUP Initialization Ack"); |
| OSMO_ASSERT(ack); |
| ack->dst = src_pdu->dst; |
| |
| /* Just copy the RTP header that was sent... TODO: tweak some RTP values?? */ |
| memcpy(msgb_put(ack, sizeof(struct rtp_hdr)), src_pdu->data, sizeof(struct rtp_hdr)); |
| |
| osmo_iuup_make_init_ack(ack); |
| |
| LOGP(DIUUP, LOGL_DEBUG, "(%s) Sending Initialization ACK %p\n", cn->name, cn->cfg.node_priv); |
| rc = cn->cfg.tx_msg(ack, cn->cfg.node_priv); |
| msgb_free(ack); |
| return rc; |
| } |
| |
| static int rx_control(struct osmo_iuup_cn *cn, struct msgb *pdu, |
| struct osmo_iuup_hdr_ctrl *hdr) |
| { |
| switch (hdr->procedure) { |
| case OSMO_IUUP_PROC_INITIALIZATION: |
| switch (hdr->ack_nack) { |
| case OSMO_IUUP_ACKNACK_PROCEDURE: |
| LOGP(DIUUP, LOGL_INFO, "(%s) Rx IuUP Initialization, sending ACK\n", cn->name); |
| cn->rtp_payload_type = ((struct rtp_hdr*)pdu->data)->payload_type; |
| return tx_init_ack(cn, pdu); |
| |
| default: |
| LOGP(DIUUP, LOGL_DEBUG, "(%s) Rx IuUP Initialization, unhandled ack_nack = %d\n", |
| cn->name, hdr->ack_nack); |
| break; |
| } |
| /* Continue to log "unexpected procedure" below. */ |
| break; |
| |
| case OSMO_IUUP_PROC_ERROR_EVENT: |
| { |
| union osmo_iuup_hdr_ctrl_payload *p = (void*)hdr->payload; |
| LOGP(DIUUP, LOGL_ERROR, |
| "(%s) Rx IuUP Error Event: distance=%u, cause=%u=\"%s\"\n", |
| cn->name, p->error_event.error_distance, p->error_event.error_cause, |
| osmo_iuup_error_cause_name(p->error_event.error_cause)); |
| return 0; |
| } |
| |
| default: |
| break; |
| } |
| LOG_IUUP_CN(cn, LOGL_ERROR, |
| "Rx control PDU with unexpected procedure: 0x%x acknack=0x%x\n", |
| hdr->procedure, hdr->ack_nack); |
| return -EINVAL; |
| } |
| |
| /* Feed a received PDU to the IuUP CN node. This function takes ownership of the msgb, it must not be |
| * freed by the caller. */ |
| int osmo_iuup_cn_rx_pdu(struct osmo_iuup_cn *cn, struct msgb *pdu) |
| { |
| struct osmo_iuup_hdr_ctrl *is_ctrl; |
| struct osmo_iuup_hdr_data *is_data; |
| int rc; |
| |
| rc = osmo_iuup_classify(true, cn->name, pdu, &is_ctrl, &is_data); |
| if (rc) |
| return rc; |
| |
| if (is_ctrl) |
| return rx_control(cn, pdu, is_ctrl); |
| if (is_data) |
| return rx_data(cn, pdu, is_data); |
| return rc; |
| } |
| |
| static uint8_t next_frame_nr(struct osmo_iuup_cn *cn) |
| { |
| uint8_t frame_nr = cn->next_frame_nr; |
| cn->next_frame_nr = (frame_nr + 1) & 0x0f; |
| return frame_nr; |
| } |
| |
| /* Send this RTP packet to the IuUP peer: add IuUP header and call the tx_msg() to transmit the resulting |
| * message to the IuUP peer. |
| * Returns 0 on success, negative on error. */ |
| int osmo_iuup_cn_tx_payload(struct osmo_iuup_cn *cn, struct msgb *pdu) |
| { |
| struct rtp_hdr *rtp_was, *rtp; |
| struct osmo_iuup_hdr_data *iuup_hdr; |
| |
| /* Splice an IuUP header in between RTP header and payload data */ |
| rtp_was = (void*)pdu->data; |
| |
| /* copy the RTP header part backwards by the size needed for the IuUP header */ |
| /* also strips 2 bytes from the front of RTP payload - AMR header - AD HOC fix */ |
| rtp = (void*)msgb_push(pdu, sizeof(*iuup_hdr) - 2); |
| memmove(rtp, rtp_was, sizeof(*rtp)); |
| |
| /* Send the same payload type to the peer (erm...) */ |
| rtp->payload_type = cn->rtp_payload_type; |
| |
| iuup_hdr = (void*)rtp->data; |
| |
| *iuup_hdr = (struct osmo_iuup_hdr_data){ |
| .pdu_type = OSMO_IUUP_PDU_DATA_WITH_CRC, |
| .frame_nr = next_frame_nr(cn), |
| .frame_good = OSMO_IUUP_FRAME_GOOD, |
| }; |
| |
| osmo_iuup_set_checksums((uint8_t*)iuup_hdr, pdu->tail - (uint8_t*)iuup_hdr); |
| LOGP(DIUUP, LOGL_DEBUG, "(%s) IuUP inserting IuUP header in RTP data (frame nr %u)\n", |
| cn->name, iuup_hdr->frame_nr); |
| |
| return cn->cfg.tx_msg(pdu, cn->cfg.node_priv); |
| } |