1 /* Layer1 control code, talking L1CTL protocol with L1 on the phone */
3 /* (C) 2010 by Holger Hans Peter Freyther <zecke@selfish.org>
4 * (C) 2010 by Harald Welte <laforge@gnumonks.org>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
28 #include <l1a_l23_interface.h>
30 #include <osmocore/timer.h>
31 #include <osmocore/msgb.h>
32 #include <osmocore/tlv.h>
33 #include <osmocore/protocol/gsm_04_08.h>
34 #include <osmocore/protocol/gsm_08_58.h>
36 #include <osmocom/l1ctl.h>
37 #include <osmocom/osmocom_data.h>
38 #include <osmocom/lapdm.h>
39 #include <osmocom/debug.h>
41 #include "gsmtap_util.h"
43 static struct msgb *osmo_l1_alloc(uint8_t msg_type)
45 struct l1ctl_info_ul *ul;
46 struct msgb *msg = msgb_alloc_headroom(256, 4, "osmo_l1");
49 fprintf(stderr, "Failed to allocate memory.\n");
53 msg->l1h = msgb_put(msg, sizeof(*ul));
54 ul = (struct l1ctl_info_ul *) msg->l1h;
55 ul->msg_type = msg_type;
61 static int osmo_make_band_arfcn(struct osmocom_ms *ms)
63 /* TODO: Include the band */
67 static int rx_l1_ccch_resp(struct osmocom_ms *ms, struct msgb *msg)
69 struct l1ctl_info_dl *dl;
70 struct l1ctl_sync_new_ccch_resp *sb;
72 if (msgb_l3len(msg) < sizeof(*sb)) {
73 fprintf(stderr, "MSG too short for CCCH RESP: %u\n", msgb_l3len(msg));
77 dl = (struct l1ctl_info_dl *) msg->l1h;
78 sb = (struct l1ctl_sync_new_ccch_resp *) msg->l2h;
80 printf("SCH: SNR: %u TDMA: (%.4u/%.2u/%.2u) bsic: %d\n",
81 dl->snr[0], dl->time.t1, dl->time.t2, dl->time.t3, sb->bsic);
86 char *chan_nr2string(uint8_t chan_nr)
89 uint8_t cbits = chan_nr >> 3;
94 sprintf(str, "TCH/F");
95 else if ((cbits & 0x1e) == 0x02)
96 sprintf(str, "TCH/H(%u)", cbits & 0x01);
97 else if ((cbits & 0x1c) == 0x04)
98 sprintf(str, "SDCCH/4(%u)", cbits & 0x03);
99 else if ((cbits & 0x18) == 0x08)
100 sprintf(str, "SDCCH/8(%u)", cbits & 0x07);
101 else if (cbits == 0x10)
102 sprintf(str, "BCCH");
103 else if (cbits == 0x11)
104 sprintf(str, "RACH");
105 else if (cbits == 0x12)
106 sprintf(str, "PCH/AGCH");
108 sprintf(str, "UNKNOWN");
113 /* Receive L1CTL_DATA_IND (Data Indication from L1) */
114 static int rx_ph_data_ind(struct osmocom_ms *ms, struct msgb *msg)
116 struct l1ctl_info_dl *dl, dl_cpy;
117 struct l1ctl_data_ind *ccch;
118 struct lapdm_entity *le;
120 if (msgb_l3len(msg) < sizeof(*ccch)) {
121 fprintf(stderr, "MSG too short Data Ind: %u\n", msgb_l3len(msg));
125 dl = (struct l1ctl_info_dl *) msg->l1h;
126 ccch = (struct l1ctl_data_ind *) msg->l2h;
127 printf("%s (%.4u/%.2u/%.2u) %s\n",
128 chan_nr2string(dl->chan_nr), dl->time.t1, dl->time.t2,
129 dl->time.t3, hexdump(ccch->data, sizeof(ccch->data)));
131 /* send CCCH data via GSMTAP */
132 gsmtap_sendmsg(dl->chan_nr & 0x07, dl->band_arfcn, dl->time.fn, ccch->data,
135 /* determine LAPDm entity based on SACCH or not */
136 if (dl->link_id & 0x40)
137 le = &ms->lapdm_acch;
139 le = &ms->lapdm_dcch;
140 /* make local stack copy of l1ctl_info_dl, as LAPDm will overwrite skb hdr */
141 memcpy(&dl_cpy, dl, sizeof(dl_cpy));
143 /* pull the L1 header from the msgb */
144 msgb_pull(msg, msg->l2h - msg->l1h);
147 /* send it up into LAPDm */
148 l2_ph_data_ind(msg, le, &dl_cpy);
153 /* Transmit L1CTL_DATA_REQ */
154 int tx_ph_data_req(struct osmocom_ms *ms, struct msgb *msg,
155 uint8_t chan_nr, uint8_t link_id)
157 struct l1ctl_info_ul *l1i_ul;
159 printf("tx_ph_data_req(%s)\n", hexdump(msg->l2h, msgb_l2len(msg)));
161 if (msgb_l2len(msg) > 23) {
162 printf("L1 cannot handle message length > 23 (%u)\n", msgb_l2len(msg));
165 } else if (msgb_l2len(msg) < 23)
166 printf("L1 message length < 23 (%u) doesn't seem right!\n", msgb_l2len(msg));
168 /* prepend uplink info header */
169 printf("sizeof(struct l1ctl_info_ul)=%lu\n", sizeof(*l1i_ul));
170 msg->l1h = msgb_push(msg, sizeof(*l1i_ul));
171 l1i_ul = (struct l1ctl_info_ul *) msg->l1h;
173 l1i_ul->msg_type = L1CTL_DATA_REQ;
175 l1i_ul->chan_nr = chan_nr;
176 l1i_ul->link_id = link_id;
178 /* FIXME: where to get this from? */
179 l1i_ul->tx_power = 0;
181 return osmo_send_l1(ms, msg);
184 /* Receive L1CTL_RESET */
185 static int rx_l1_reset(struct osmocom_ms *ms)
188 struct l1ctl_sync_new_ccch_req *req;
190 msg = osmo_l1_alloc(L1CTL_NEW_CCCH_REQ);
194 printf("Layer1 Reset.\n");
195 req = (struct l1ctl_sync_new_ccch_req *) msgb_put(msg, sizeof(*req));
196 req->band_arfcn = osmo_make_band_arfcn(ms);
198 return osmo_send_l1(ms, msg);
201 /* Transmit L1CTL_RACH_REQ */
202 int tx_ph_rach_req(struct osmocom_ms *ms)
205 struct l1ctl_rach_req *req;
206 static uint8_t i = 0;
208 msg = osmo_l1_alloc(L1CTL_RACH_REQ);
212 printf("RACH Req.\n");
213 req = (struct l1ctl_rach_req *) msgb_put(msg, sizeof(*req));
216 return osmo_send_l1(ms, msg);
219 /* Transmit L1CTL_DM_EST_REQ */
220 int tx_ph_dm_est_req(struct osmocom_ms *ms, uint16_t band_arfcn, uint8_t chan_nr)
223 struct l1ctl_info_ul *ul;
224 struct l1ctl_dm_est_req *req;
226 msg = osmo_l1_alloc(L1CTL_DM_EST_REQ);
230 printf("Tx Dedic.Mode Est Req (arfcn=%u, chan_nr=0x%02x)\n",
231 band_arfcn, chan_nr);
232 ul = (struct l1ctl_info_ul *) msg->l1h;
233 ul->chan_nr = chan_nr;
235 ul->tx_power = 0; /* FIXME: initial TX power */
236 req = (struct l1ctl_dm_est_req *) msgb_put(msg, sizeof(*req));
237 req->band_arfcn = band_arfcn;
239 return osmo_send_l1(ms, msg);
243 /* Receive incoming data from L1 using L1CTL format */
244 int l1ctl_recv(struct osmocom_ms *ms, struct msgb *msg)
247 struct l1ctl_info_dl *dl;
249 if (msgb_l2len(msg) < sizeof(*dl)) {
250 fprintf(stderr, "Short Layer2 message: %u\n", msgb_l2len(msg));
254 dl = (struct l1ctl_info_dl *) msg->l1h;
255 msg->l2h = &msg->l1h[0] + sizeof(*dl);
257 switch (dl->msg_type) {
258 case L1CTL_NEW_CCCH_RESP:
259 rc = rx_l1_ccch_resp(ms, msg);
262 rc = rx_ph_data_ind(ms, msg);
265 rc = rx_l1_reset(ms);
268 fprintf(stderr, "Unknown MSG: %u\n", dl->msg_type);