/* Code to manage MSC RAN connections over IuCS interface */ /* * (C) 2016,2017 by sysmocom s.f.m.c. GmbH * * Author: Neels Hofmeyr * * All Rights Reserved * * 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 . * */ #include #include #include #include #include #include #include #include #include #include "../../bscconfig.h" #ifdef BUILD_IU #include extern struct msgb *ranap_new_msg_rab_assign_voice(uint8_t rab_id, uint32_t rtp_ip, uint16_t rtp_port, bool use_x213_nsap); #else #include #endif /* BUILD_IU */ /* For A-interface see libbsc/bsc_api.c subscr_con_allocate() */ static struct ran_conn *ran_conn_allocate_iu(struct gsm_network *network, struct ranap_ue_conn_ctx *ue, uint16_t lac) { struct ran_conn *conn; DEBUGP(DIUCS, "Allocating IuCS RAN conn: lac %d, conn_id %" PRIx32 "\n", lac, ue->conn_id); conn = ran_conn_alloc(network, OSMO_RAT_UTRAN_IU, lac); if (!conn) return NULL; conn->iu.ue_ctx = ue; conn->iu.ue_ctx->rab_assign_addr_enc = network->iu.rab_assign_addr_enc; return conn; } static int same_ue_conn(struct ranap_ue_conn_ctx *a, struct ranap_ue_conn_ctx *b) { if (a == b) return 1; return (a->conn_id == b->conn_id); } static inline void log_subscribers(struct gsm_network *network) { if (!log_check_level(DIUCS, LOGL_DEBUG)) return; struct ran_conn *conn; int i = 0; llist_for_each_entry(conn, &network->ran_conns, entry) { DEBUGP(DIUCS, "%3d: %s", i, vlr_subscr_name(conn->vsub)); switch (conn->via_ran) { case OSMO_RAT_UTRAN_IU: DEBUGPC(DIUCS, " Iu"); if (conn->iu.ue_ctx) { DEBUGPC(DIUCS, " conn_id %d", conn->iu.ue_ctx->conn_id ); } break; case OSMO_RAT_GERAN_A: DEBUGPC(DIUCS, " A"); /* TODO log A-interface connection details */ break; case OSMO_RAT_UNKNOWN: DEBUGPC(DIUCS, " ?"); break; default: DEBUGPC(DIUCS, " invalid"); break; } DEBUGPC(DIUCS, "\n"); i++; } DEBUGP(DIUCS, "subscribers registered: %d\n", i); } /* Return an existing IuCS RAN connection record for the given * connection IDs, or return NULL if not found. */ struct ran_conn *ran_conn_lookup_iu( struct gsm_network *network, struct ranap_ue_conn_ctx *ue) { struct ran_conn *conn; DEBUGP(DIUCS, "Looking for IuCS subscriber: conn_id %" PRIx32 "\n", ue->conn_id); log_subscribers(network); llist_for_each_entry(conn, &network->ran_conns, entry) { if (conn->via_ran != OSMO_RAT_UTRAN_IU) continue; if (!same_ue_conn(conn->iu.ue_ctx, ue)) continue; DEBUGP(DIUCS, "Found IuCS subscriber for conn_id %" PRIx32 "\n", ue->conn_id); return conn; } DEBUGP(DIUCS, "No IuCS subscriber found for conn_id %" PRIx32 "\n", ue->conn_id); return NULL; } /* Receive MM/CC/... message from IuCS (SCCP user SAP). * msg->dst must reference a struct ranap_ue_conn_ctx, which identifies the peer that * sent the msg. * * For A-interface see libbsc/bsc_api.c gsm0408_rcvmsg(). */ int gsm0408_rcvmsg_iucs(struct gsm_network *network, struct msgb *msg, uint16_t *lac) { struct ranap_ue_conn_ctx *ue_ctx; struct ran_conn *conn; ue_ctx = (struct ranap_ue_conn_ctx*)msg->dst; /* TODO: are there message types that could allow us to skip this * search? */ conn = ran_conn_lookup_iu(network, ue_ctx); if (conn && lac && (conn->lac != *lac)) { LOGP(DIUCS, LOGL_ERROR, "IuCS subscriber has changed LAC" " within the same connection, discarding connection:" " %s from LAC %d to %d\n", vlr_subscr_name(conn->vsub), conn->lac, *lac); /* Deallocate conn with previous LAC */ ran_conn_close(conn, GSM_CAUSE_INV_MAND_INFO); /* At this point we could be tolerant and allocate a new * connection, but changing the LAC within the same connection * is shifty. Rather cancel everything. */ return -1; } if (conn) { /* Make sure we don't receive RR over IuCS; otherwise all * messages handled by gsm0408_dispatch() are of interest (CC, * MM, SMS, NS_SS, maybe even MM_GPRS and SM_GPRS). */ struct gsm48_hdr *gh = msgb_l3(msg); uint8_t pdisc = gh->proto_discr & 0x0f; OSMO_ASSERT(pdisc != GSM48_PDISC_RR); ran_conn_dtap(conn, msg); } else { /* allocate a new connection */ if (!lac) { LOGP(DIUCS, LOGL_ERROR, "New IuCS subscriber" " but no LAC available. Expecting an InitialUE" " message containing a LAI IE." " Dropping connection.\n"); return -1; } conn = ran_conn_allocate_iu(network, ue_ctx, *lac); if (!conn) abort(); /* ownership of conn hereby goes to the MSC: */ ran_conn_compl_l3(conn, msg, 0); } return 0; } int iu_rab_act_cs(struct gsm_trans *trans) { struct ran_conn *conn; struct msgb *msg; bool use_x213_nsap; uint32_t conn_id; struct ranap_ue_conn_ctx *uectx; uint8_t rab_id; uint32_t rtp_ip; uint16_t rtp_port; conn = trans->conn; uectx = conn->iu.ue_ctx; rab_id = conn->iu.rab_id; rtp_ip = osmo_htonl(inet_addr(conn->rtp.local_addr_ran)); rtp_port = conn->rtp.local_port_ran; conn_id = uectx->conn_id; if (rtp_ip == INADDR_NONE) { LOGP(DIUCS, LOGL_DEBUG, "Assigning RAB: conn_id=%u, rab_id=%d, invalid RTP IP-Address\n", conn_id, rab_id); return -EINVAL; } if (rtp_port == 0) { LOGP(DIUCS, LOGL_DEBUG, "Assigning RAB: conn_id=%u, rab_id=%d, invalid RTP Port\n", conn_id, rab_id); return -EINVAL; } use_x213_nsap = (uectx->rab_assign_addr_enc == RANAP_NSAP_ADDR_ENC_X213); LOGP(DIUCS, LOGL_DEBUG, "Assigning RAB: conn_id=%u, rab_id=%d, rtp=%x:%u, use_x213_nsap=%d\n", conn_id, rab_id, rtp_ip, rtp_port, use_x213_nsap); msg = ranap_new_msg_rab_assign_voice(rab_id, rtp_ip, rtp_port, use_x213_nsap); msg->l2h = msg->data; if (ranap_iu_rab_act(uectx, msg)) LOGP(DIUCS, LOGL_ERROR, "Failed to send RAB Assignment: conn_id=%d rab_id=%d rtp=%x:%u\n", conn_id, rab_id, rtp_ip, rtp_port); return 0; } uint32_t iu_get_conn_id(const struct ranap_ue_conn_ctx *ue) { return ue->conn_id; }