diff --git a/include/osmocom/bsc_nat/Makefile.am b/include/osmocom/bsc_nat/Makefile.am index 90f44a7..76aada0 100644 --- a/include/osmocom/bsc_nat/Makefile.am +++ b/include/osmocom/bsc_nat/Makefile.am @@ -1,6 +1,7 @@ noinst_HEADERS = \ bsc_nat.h \ bsc_nat_fsm.h \ + bssap.h \ logging.h \ vty.h \ $(NULL) diff --git a/include/osmocom/bsc_nat/bssap.h b/include/osmocom/bsc_nat/bssap.h new file mode 100644 index 0000000..996cb69 --- /dev/null +++ b/include/osmocom/bsc_nat/bssap.h @@ -0,0 +1,25 @@ +/* (C) 2022 by sysmocom - s.f.m.c. GmbH + * Author: Oliver Smith + * 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 . + * + */ + +#pragma once + +#include + +int bssap_handle_udt(struct bsc_nat_sccp_inst *sccp_inst, struct osmo_sccp_addr *addr, struct msgb *msgb, + unsigned int length); diff --git a/src/osmo-bsc-nat/Makefile.am b/src/osmo-bsc-nat/Makefile.am index 6a759cb..445c098 100644 --- a/src/osmo-bsc-nat/Makefile.am +++ b/src/osmo-bsc-nat/Makefile.am @@ -27,6 +27,7 @@ bin_PROGRAMS = \ osmo_bsc_nat_SOURCES = \ bsc_nat.c \ bsc_nat_fsm.c \ + bssap.c \ logging.c \ main.c \ vty.c \ diff --git a/src/osmo-bsc-nat/bsc_nat_fsm.c b/src/osmo-bsc-nat/bsc_nat_fsm.c index 4ce60ce..0c36607 100644 --- a/src/osmo-bsc-nat/bsc_nat_fsm.c +++ b/src/osmo-bsc-nat/bsc_nat_fsm.c @@ -27,6 +27,7 @@ #include #include #include +#include #include #define DEFAULT_PC_RAN "0.23.1" /* same as default for OsmoMSC */ @@ -299,6 +300,10 @@ static int sccp_sap_up_ran(struct osmo_prim_hdr *oph, void *scu) case OSMO_PRIM(OSMO_SCU_PRIM_N_UNITDATA, PRIM_OP_INDICATION): /* connection-less data received */ + rc = bssap_handle_udt(sccp_inst, &prim->u.unitdata.calling_addr, oph->msg, msgb_l2len(oph->msg)); + + /* FIXME: don't forward this to the MSC anymore, as soon as the + * BSCNAT is able to do the RESET to MSC by itself. */ addr = &prim->u.unitdata.calling_addr; if (sccp_sap_get_peer_addr_out(sccp_inst, addr, &peer_addr_out) < 0) @@ -314,7 +319,6 @@ static int sccp_sap_up_ran(struct osmo_prim_hdr *oph, void *scu) &peer_addr_out, oph->msg->data, msgb_length(oph->msg)); - rc = 0; break; default: diff --git a/src/osmo-bsc-nat/bssap.c b/src/osmo-bsc-nat/bssap.c new file mode 100644 index 0000000..c054db6 --- /dev/null +++ b/src/osmo-bsc-nat/bssap.c @@ -0,0 +1,98 @@ +/* (C) 2022 by sysmocom - s.f.m.c. GmbH + * Author: Oliver Smith + * 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 "config.h" +#include +#include +#include +#include +#include +#include + +static int bssap_ran_handle_reset(struct osmo_sccp_addr *addr, struct msgb *msg, unsigned int length) +{ + struct bsc_nat_sccp_inst *sccp_inst = g_bsc_nat->ran; + + LOGP(DMAIN, LOGL_NOTICE, "Rx RESET from %s\n", bsc_nat_print_addr(sccp_inst, addr)); + + LOGP(DMAIN, LOGL_NOTICE, "Tx RESET ACK to %s\n", bsc_nat_print_addr(sccp_inst, addr)); + msg = gsm0808_create_reset_ack(); + return osmo_sccp_tx_unitdata_msg(sccp_inst->scu, &sccp_inst->addr, addr, msg); +} + +static int bssap_ran_rcvmsg_udt(struct osmo_sccp_addr *addr, struct msgb *msg, unsigned int length) +{ + int ret = 0; + + switch (msg->l3h[0]) { + case BSS_MAP_MSG_RESET: + ret = bssap_ran_handle_reset(addr, msg, length); + break; + default: + LOGP(DMAIN, LOGL_NOTICE, "Unimplemented BSSMAP UDT %s\n", gsm0808_bssap_name(msg->l3h[0])); + break; + } + + return ret; +} + +static int bssap_rcvmsg_udt(struct bsc_nat_sccp_inst *sccp_inst, struct osmo_sccp_addr *addr, struct msgb *msg, + unsigned int length) +{ + if (length < 1) { + LOGP(DMAIN, LOGL_ERROR, "Not enough room: %u\n", length); + return -1; + } + + LOGP(DMAIN, LOGL_NOTICE, "Rx UDT BSSMAP %s\n", gsm0808_bssap_name(msg->l3h[0])); + + /* NOTE: bssap_cn_rcvmsg_udt() will be added in a future patch */ + return bssap_ran_rcvmsg_udt(addr, msg, length); +} + +int bssap_handle_udt(struct bsc_nat_sccp_inst *sccp_inst, struct osmo_sccp_addr *addr, struct msgb *msgb, + unsigned int length) +{ + struct bssmap_header *bs; + int rc = -1; + + LOGP(DMAIN, LOGL_DEBUG, "Rx UDT: %s\n", osmo_hexdump(msgb->l2h, length)); + + if (length < sizeof(*bs)) { + LOGP(DMAIN, LOGL_ERROR, "The header is too short\n"); + return -1; + } + + bs = (struct bssmap_header *)msgb->l2h; + if (bs->length < length - sizeof(*bs)) { + LOGP(DMAIN, LOGL_ERROR, "Failed to parse BSSMAP header\n"); + return -1; + } + + switch (bs->type) { + case BSSAP_MSG_BSS_MANAGEMENT: + msgb->l3h = &msgb->l2h[sizeof(*bs)]; + rc = bssap_rcvmsg_udt(sccp_inst, addr, msgb, length - sizeof(*bs)); + break; + default: + LOGP(DMAIN, LOGL_NOTICE, "Unimplemented msg type: %s\n", gsm0808_bssap_name(bs->type)); + } + + return rc; +}