Split of L1 interface to be used with OpenBTS or sysmo-BTS
The OpenBTS socket functions are moved from main to pcu_l1_if.cpp.
New sysmo_l1_if.cpp is introduced. It used special unix socket interface
to connect to sysmo-BTS. This is required to access CCCH/RACH and info
about cell layout. Traffic is also forwarded via this interface, but
it direct access of L1 baseband DSP will be added soon.
In order to handle ready-to-send requests above l1_if, the transmit
queue (for downlink blocks) is moved to gprs_rlcmac.cpp.
The TBF instance additionally holds TRX and TS info, but this is only
a hack currently. TBF instance requires more details about allocated
ressources in the future.
diff --git a/src/sysmo_l1_if.cpp b/src/sysmo_l1_if.cpp
new file mode 100644
index 0000000..09a3149
--- /dev/null
+++ b/src/sysmo_l1_if.cpp
@@ -0,0 +1,562 @@
+/* sysmo_l1_if.cpp
+ *
+ * Copyright (C) 2012 Andreas Eversberg <jolly@eversberg.eu>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <assert.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+extern "C" {
+#include <osmocom/core/talloc.h>
+#include <osmocom/core/select.h>
+#include <osmocom/core/msgb.h>
+}
+
+#include <gprs_rlcmac.h>
+#include <pcu_l1_if.h>
+#include <gprs_debug.h>
+#include "../../osmo-bts/include/osmo-bts/pcuif_proto.h"
+
+static int pcu_sock_send(struct msgb *msg);
+static void pcu_sock_timeout(void *_priv);
+
+struct pcu_l1if_bts pcu_l1if_bts;
+
+// Variable for storage current FN.
+int frame_number;
+
+int get_current_fn()
+{
+ return frame_number;
+}
+
+void set_current_fn(int fn)
+{
+ frame_number = fn;
+}
+
+/*
+ * PCU messages
+ */
+
+struct msgb *pcu_msgb_alloc(uint8_t msg_type, uint8_t bts_nr)
+{
+ struct msgb *msg;
+ struct gsm_pcu_if *pcu_prim;
+
+ msg = msgb_alloc(sizeof(struct gsm_pcu_if), "pcu_sock_tx");
+ if (!msg)
+ return NULL;
+ msgb_put(msg, sizeof(struct gsm_pcu_if));
+ pcu_prim = (struct gsm_pcu_if *) msg->data;
+ pcu_prim->msg_type = msg_type;
+ pcu_prim->bts_nr = bts_nr;
+
+ return msg;
+}
+
+static int pcu_tx_act_req(uint8_t trx, uint8_t ts, uint8_t activate)
+{
+ struct msgb *msg;
+ struct gsm_pcu_if *pcu_prim;
+ struct gsm_pcu_if_act_req *act_req;
+
+ LOGP(DL1IF, LOGL_INFO, "Sending %s request: trx=%d ts=%d\n",
+ (activate) ? "activate" : "deactivate", trx, ts);
+
+ msg = pcu_msgb_alloc(PCU_IF_MSG_ACT_REQ, 0);
+ if (!msg)
+ return -ENOMEM;
+ pcu_prim = (struct gsm_pcu_if *) msg->data;
+ act_req = &pcu_prim->u.act_req;
+ act_req->activate = activate;
+ act_req->trx_nr = trx;
+ act_req->ts_nr = ts;
+
+ return pcu_sock_send(msg);
+}
+
+static int pcu_tx_data_req(uint8_t trx, uint8_t ts, uint8_t sapi,
+ uint16_t arfcn, uint32_t fn, uint8_t block_nr, uint8_t *data,
+ uint8_t len)
+{
+ struct msgb *msg;
+ struct gsm_pcu_if *pcu_prim;
+ struct gsm_pcu_if_data *data_req;
+
+ LOGP(DL1IF, LOGL_DEBUG, "Sending data request: trx=%d ts=%d sapi=%d "
+ "arfcn=%d fn=%d block=%d data=%s\n", trx, ts, sapi, arfcn, fn,
+ block_nr, osmo_hexdump(data, len));
+
+ msg = pcu_msgb_alloc(PCU_IF_MSG_DATA_REQ, 0);
+ if (!msg)
+ return -ENOMEM;
+ pcu_prim = (struct gsm_pcu_if *) msg->data;
+ data_req = &pcu_prim->u.data_req;
+
+ data_req->sapi = sapi;
+ data_req->fn = fn;
+ data_req->arfcn = arfcn;
+ data_req->trx_nr = trx;
+ data_req->ts_nr = ts;
+ data_req->block_nr = block_nr;
+ memcpy(data_req->data, data, len);
+ data_req->len = len;
+
+ return pcu_sock_send(msg);
+}
+
+void pcu_l1if_tx_pdtch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn,
+ uint32_t fn, uint8_t block_nr)
+{
+ pcu_tx_data_req(trx, ts, PCU_IF_SAPI_PDTCH, arfcn, fn, block_nr,
+ msg->data, msg->len);
+ msgb_free(msg);
+}
+
+void pcu_l1if_tx_ptcch(msgb *msg, uint8_t trx, uint8_t ts, uint16_t arfcn,
+ uint32_t fn, uint8_t block_nr)
+{
+ pcu_tx_data_req(trx, ts, PCU_IF_SAPI_PTCCH, arfcn, fn, block_nr,
+ msg->data, msg->len);
+ msgb_free(msg);
+}
+
+void pcu_l1if_tx_agch(bitvec * block, int len)
+{
+ uint8_t data[24]; /* prefix PLEN */
+
+ /* FIXME: why does OpenBTS has no PLEN and no fill in message? */
+ bitvec_pack(block, data + 1);
+ data[0] = (len << 2) | 0x01;
+ pcu_tx_data_req(0, 0, PCU_IF_SAPI_AGCH, 0, 0, 0, data, 23);
+}
+
+static void pcu_l1if_tx_bcch(uint8_t *data, int len)
+{
+ pcu_tx_data_req(0, 0, PCU_IF_SAPI_BCCH, 0, 0, 0, data, len);
+}
+
+static int pcu_rx_data_ind(struct gsm_pcu_if_data *data_ind)
+{
+ int rc = 0;
+ bitvec *block;
+
+ LOGP(DL1IF, LOGL_DEBUG, "Data indication received: sapi=%d arfcn=%d "
+ "block=%d data=%s\n", data_ind->sapi,
+ data_ind->arfcn, data_ind->block_nr,
+ osmo_hexdump(data_ind->data, data_ind->len));
+
+ switch (data_ind->sapi) {
+ case PCU_IF_SAPI_PDTCH:
+ block = bitvec_alloc(data_ind->len);
+ if (!block) {
+ rc = -ENOMEM;
+ break;
+ }
+ bitvec_unpack(block, data_ind->data);
+ gprs_rlcmac_rcv_block(block);
+ bitvec_free(block);
+ break;
+ default:
+ LOGP(DL1IF, LOGL_ERROR, "Received PCU data indication with "
+ "unsupported sapi %d\n", data_ind->sapi);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+static int pcu_rx_rts_req(struct gsm_pcu_if_rts_req *rts_req)
+{
+ int rc = 0;
+
+ LOGP(DL1IF, LOGL_DEBUG, "RTS request received: trx=%d ts=%d sapi=%d "
+ "arfcn=%d fn=%d block=%d\n", rts_req->trx_nr, rts_req->ts_nr,
+ rts_req->sapi, rts_req->arfcn, rts_req->fn, rts_req->block_nr);
+
+ switch (rts_req->sapi) {
+ case PCU_IF_SAPI_PDTCH:
+ gprs_rlcmac_rcv_rts_block(rts_req->trx_nr, rts_req->ts_nr,
+ rts_req->arfcn, rts_req->fn, rts_req->block_nr);
+ break;
+ case PCU_IF_SAPI_PTCCH:
+ /* FIXME */
+ {
+ struct msgb *msg = msgb_alloc(23, "l1_prim");
+ memset(msgb_put(msg, 23), 0x2b, 23);
+ pcu_l1if_tx_ptcch(msg, rts_req->trx_nr, rts_req->ts_nr,
+ rts_req->arfcn, rts_req->fn, rts_req->block_nr);
+ }
+ break;
+ default:
+ LOGP(DL1IF, LOGL_ERROR, "Received PCU RTS request with "
+ "unsupported sapi %d\n", rts_req->sapi);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+static int pcu_rx_rach_ind(struct gsm_pcu_if_rach_ind *rach_ind)
+{
+ int rc = 0;
+
+ LOGP(DL1IF, LOGL_INFO, "RACH request received: sapi=%d "
+ "qta=%d, ra=%d, fn=%d\n", rach_ind->sapi, rach_ind->qta,
+ rach_ind->ra, rach_ind->fn);
+
+ switch (rach_ind->sapi) {
+ case PCU_IF_SAPI_RACH:
+ rc = gprs_rlcmac_rcv_rach(rach_ind->ra, rach_ind->fn,
+ rach_ind->qta);
+ break;
+ default:
+ LOGP(DL1IF, LOGL_ERROR, "Received PCU rach request with "
+ "unsupported sapi %d\n", rach_ind->sapi);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+static int pcu_rx_info_ind(struct gsm_pcu_if_info_ind *info_ind)
+{
+ int rc = 0;
+ int trx, ts;
+// uint8_t si13[23];
+
+ LOGP(DL1IF, LOGL_INFO, "Info indication received:\n");
+
+ if (!(info_ind->flags & PCU_IF_FLAG_ACTIVE)) {
+ LOGP(DL1IF, LOGL_NOTICE, "BTS not available\n");
+ return 0;
+ }
+ LOGP(DL1IF, LOGL_INFO, "BTS available\n");
+
+ for (trx = 0; trx < 8; trx++) {
+ pcu_l1if_bts.trx[trx].arfcn = info_ind->trx[trx].arfcn;
+ for (ts = 0; ts < 8; ts++) {
+ if ((info_ind->trx[trx].pdch_mask & (1 << ts))) {
+ /* FIXME: activate dynamically at RLCMAC */
+ if (!pcu_l1if_bts.trx[trx].ts[ts].enable)
+ pcu_tx_act_req(trx, ts, 1);
+ pcu_l1if_bts.trx[trx].ts[ts].enable = 1;
+ pcu_l1if_bts.trx[trx].ts[ts].tsc =
+ info_ind->trx[trx].tsc[ts];
+ LOGP(DL1IF, LOGL_INFO, "PDCH: trx=%d ts=%d\n",
+ trx, ts);
+ } else {
+ if (pcu_l1if_bts.trx[trx].ts[ts].enable)
+ pcu_tx_act_req(trx, ts, 0);
+ pcu_l1if_bts.trx[trx].ts[ts].enable = 0;
+ }
+ }
+ }
+
+#warning FIXME: RAC
+// rc = generate_si13(si13, 0 /* rac */);
+// printf("rc=%d\n", rc);
+// pcu_l1if_tx_bcch(si13, 23);
+
+ return rc;
+}
+
+static int pcu_rx(uint8_t msg_type, struct gsm_pcu_if *pcu_prim)
+{
+ int rc = 0;
+
+ switch (msg_type) {
+ case PCU_IF_MSG_DATA_IND:
+ rc = pcu_rx_data_ind(&pcu_prim->u.data_ind);
+ break;
+ case PCU_IF_MSG_RTS_REQ:
+ rc = pcu_rx_rts_req(&pcu_prim->u.rts_req);
+ break;
+ case PCU_IF_MSG_RACH_IND:
+ rc = pcu_rx_rach_ind(&pcu_prim->u.rach_ind);
+ break;
+ case PCU_IF_MSG_INFO_IND:
+ rc = pcu_rx_info_ind(&pcu_prim->u.info_ind);
+ break;
+ default:
+ LOGP(DL1IF, LOGL_ERROR, "Received unknwon PCU msg type %d\n",
+ msg_type);
+ rc = -EINVAL;
+ }
+
+ return rc;
+}
+
+/*
+ * SYSMO-PCU socket functions
+ */
+
+struct pcu_sock_state {
+ struct osmo_fd conn_bfd; /* fd for connection to lcr */
+ struct osmo_timer_list timer; /* socket connect retry timer */
+ struct llist_head upqueue; /* queue for sending messages */
+} *pcu_sock_state = NULL;
+
+static int pcu_sock_send(struct msgb *msg)
+{
+ struct pcu_sock_state *state = pcu_sock_state;
+ struct osmo_fd *conn_bfd;
+
+ if (!state) {
+ LOGP(DL1IF, LOGL_NOTICE, "PCU socket not created, dropping "
+ "message\n");
+ return -EINVAL;
+ }
+ conn_bfd = &state->conn_bfd;
+ if (conn_bfd->fd <= 0) {
+ LOGP(DL1IF, LOGL_NOTICE, "PCU socket not connected, dropping "
+ "message\n");
+ return -EIO;
+ }
+ msgb_enqueue(&state->upqueue, msg);
+ conn_bfd->when |= BSC_FD_WRITE;
+
+ return 0;
+}
+
+static void pcu_sock_close(struct pcu_sock_state *state)
+{
+ struct osmo_fd *bfd = &state->conn_bfd;
+
+ LOGP(DL1IF, LOGL_NOTICE, "PCU socket has LOST connection\n");
+
+ close(bfd->fd);
+ bfd->fd = -1;
+ osmo_fd_unregister(bfd);
+
+ /* flush the queue */
+ while (!llist_empty(&state->upqueue)) {
+ struct msgb *msg = msgb_dequeue(&state->upqueue);
+ msgb_free(msg);
+ }
+
+ /* disable all slots */
+ memset(&pcu_l1if_bts, 0, sizeof(pcu_l1if_bts));
+
+ state->timer.cb = pcu_sock_timeout;
+ osmo_timer_schedule(&state->timer, 5, 0);
+}
+
+static int pcu_sock_read(struct osmo_fd *bfd)
+{
+ struct pcu_sock_state *state = (struct pcu_sock_state *)bfd->data;
+ struct gsm_pcu_if *pcu_prim;
+ struct msgb *msg;
+ int rc;
+
+ msg = msgb_alloc(sizeof(*pcu_prim), "pcu_sock_rx");
+ if (!msg)
+ return -ENOMEM;
+
+ pcu_prim = (struct gsm_pcu_if *) msg->tail;
+
+ rc = recv(bfd->fd, msg->tail, msgb_tailroom(msg), 0);
+ if (rc == 0)
+ goto close;
+
+ if (rc < 0) {
+ if (errno == EAGAIN)
+ return 0;
+ goto close;
+ }
+
+ rc = pcu_rx(pcu_prim->msg_type, pcu_prim);
+
+ /* as we always synchronously process the message in pcu_rx() and
+ * its callbacks, we can free the message here. */
+ msgb_free(msg);
+
+ return rc;
+
+close:
+ msgb_free(msg);
+ pcu_sock_close(state);
+ return -1;
+}
+
+static int pcu_sock_write(struct osmo_fd *bfd)
+{
+ struct pcu_sock_state *state = (struct pcu_sock_state *)bfd->data;
+ int rc;
+
+ while (!llist_empty(&state->upqueue)) {
+ struct msgb *msg, *msg2;
+ struct gsm_pcu_if *pcu_prim;
+
+ /* peek at the beginning of the queue */
+ msg = llist_entry(state->upqueue.next, struct msgb, list);
+ pcu_prim = (struct gsm_pcu_if *)msg->data;
+
+ bfd->when &= ~BSC_FD_WRITE;
+
+ /* bug hunter 8-): maybe someone forgot msgb_put(...) ? */
+ if (!msgb_length(msg)) {
+ LOGP(DL1IF, LOGL_ERROR, "message type (%d) with ZERO "
+ "bytes!\n", pcu_prim->msg_type);
+ goto dontsend;
+ }
+
+ /* try to send it over the socket */
+ rc = write(bfd->fd, msgb_data(msg), msgb_length(msg));
+ if (rc == 0)
+ goto close;
+ if (rc < 0) {
+ if (errno == EAGAIN) {
+ bfd->when |= BSC_FD_WRITE;
+ break;
+ }
+ goto close;
+ }
+
+dontsend:
+ /* _after_ we send it, we can deueue */
+ msg2 = msgb_dequeue(&state->upqueue);
+ assert(msg == msg2);
+ msgb_free(msg);
+ }
+ return 0;
+
+close:
+ pcu_sock_close(state);
+
+ return -1;
+}
+
+static int pcu_sock_cb(struct osmo_fd *bfd, unsigned int flags)
+{
+ int rc = 0;
+
+ if (flags & BSC_FD_READ)
+ rc = pcu_sock_read(bfd);
+ if (rc < 0)
+ return rc;
+
+ if (flags & BSC_FD_WRITE)
+ rc = pcu_sock_write(bfd);
+
+ return rc;
+}
+
+int pcu_l1if_open(void)
+{
+ struct pcu_sock_state *state;
+ struct osmo_fd *bfd;
+ struct sockaddr_un local;
+ unsigned int namelen;
+ int rc;
+
+ memset(&pcu_l1if_bts, 0, sizeof(pcu_l1if_bts));
+
+ state = pcu_sock_state;
+ if (!state) {
+ state = talloc_zero(NULL, struct pcu_sock_state);
+ if (!state)
+ return -ENOMEM;
+ INIT_LLIST_HEAD(&state->upqueue);
+ }
+
+ bfd = &state->conn_bfd;
+
+ bfd->fd = socket(AF_UNIX, SOCK_SEQPACKET, 0);
+ if (bfd->fd < 0) {
+ LOGP(DL1IF, LOGL_ERROR, "Failed to create PCU-SYSMO socket.\n");
+ talloc_free(state);
+ return -1;
+ }
+
+ local.sun_family = AF_UNIX;
+ strncpy(local.sun_path, "/tmp/pcu_bts", sizeof(local.sun_path));
+ local.sun_path[sizeof(local.sun_path) - 1] = '\0';
+
+ /* we use the same magic that X11 uses in Xtranssock.c for
+ * calculating the proper length of the sockaddr */
+#if defined(BSD44SOCKETS) || defined(__UNIXWARE__)
+ local.sun_len = strlen(local.sun_path);
+#endif
+#if defined(BSD44SOCKETS) || defined(SUN_LEN)
+ namelen = SUN_LEN(&local);
+#else
+ namelen = strlen(local.sun_path) +
+ offsetof(struct sockaddr_un, sun_path);
+#endif
+ rc = connect(bfd->fd, (struct sockaddr *) &local, namelen);
+ if (rc != 0) {
+ LOGP(DL1IF, LOGL_ERROR, "Failed to Connect the PCU-SYSMO "
+ "socket, delaying... '%s'\n", local.sun_path);
+ close(bfd->fd);
+ bfd->fd = -1;
+ state->timer.cb = pcu_sock_timeout;
+ osmo_timer_schedule(&state->timer, 5, 0);
+ return -1;
+ }
+
+ bfd->when = BSC_FD_READ;
+ bfd->cb = pcu_sock_cb;
+ bfd->data = state;
+
+ rc = osmo_fd_register(bfd);
+ if (rc < 0) {
+ LOGP(DL1IF, LOGL_ERROR, "Could not register PCU fd: %d\n", rc);
+ close(bfd->fd);
+ talloc_free(state);
+ return rc;
+ }
+
+ LOGP(DL1IF, LOGL_NOTICE, "PCU-SYSMO socket has been connected\n");
+
+ pcu_sock_state = state;
+
+ return 0;
+}
+
+void pcu_l1if_close(void)
+{
+ struct pcu_sock_state *state = pcu_sock_state;
+ struct osmo_fd *bfd;
+
+ if (!state)
+ return;
+
+ if (osmo_timer_pending(&state->timer))
+ osmo_timer_del(&state->timer);
+
+ bfd = &state->conn_bfd;
+ if (bfd->fd > 0)
+ pcu_sock_close(state);
+ talloc_free(state);
+ pcu_sock_state = NULL;
+}
+
+static void pcu_sock_timeout(void *_priv)
+{
+ pcu_l1if_open();
+}
+
+
+
+