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.
29 #include <arpa/inet.h>
31 #include <l1a_l23_interface.h>
33 #include <osmocore/timer.h>
34 #include <osmocore/msgb.h>
35 #include <osmocore/tlv.h>
36 #include <osmocore/gsm_utils.h>
37 #include <osmocore/protocol/gsm_04_08.h>
38 #include <osmocore/protocol/gsm_08_58.h>
39 #include <osmocore/rsl.h>
41 #include <osmocom/l1ctl.h>
42 #include <osmocom/osmocom_data.h>
43 #include <osmocom/lapdm.h>
44 #include <osmocom/debug.h>
45 #include <osmocom/gsmtap_util.h>
47 static struct msgb *osmo_l1_alloc(uint8_t msg_type)
49 struct l1ctl_hdr *l1h;
50 struct msgb *msg = msgb_alloc_headroom(256, 4, "osmo_l1");
53 fprintf(stderr, "Failed to allocate memory.\n");
57 msg->l1h = msgb_put(msg, sizeof(*l1h));
58 l1h = (struct l1ctl_hdr *) msg->l1h;
59 l1h->msg_type = msg_type;
65 static int osmo_make_band_arfcn(struct osmocom_ms *ms)
67 /* TODO: Include the band */
71 static int rx_l1_ccch_resp(struct osmocom_ms *ms, struct msgb *msg)
73 struct l1ctl_info_dl *dl;
74 struct l1ctl_sync_new_ccch_resp *sb;
77 if (msgb_l3len(msg) < sizeof(*sb)) {
78 fprintf(stderr, "MSG too short for CCCH RESP: %u\n", msgb_l3len(msg));
82 dl = (struct l1ctl_info_dl *) msg->l1h;
83 sb = (struct l1ctl_sync_new_ccch_resp *) dl->payload;
85 gsm_fn2gsmtime(&tm, ntohl(dl->frame_nr));
86 printf("SCH: SNR: %u TDMA: (%.4u/%.2u/%.2u) bsic: %d\n",
87 dl->snr, tm.t1, tm.t2, tm.t3, sb->bsic);
92 char *chan_nr2string(uint8_t chan_nr)
95 uint8_t cbits = chan_nr >> 3;
100 sprintf(str, "TCH/F");
101 else if ((cbits & 0x1e) == 0x02)
102 sprintf(str, "TCH/H(%u)", cbits & 0x01);
103 else if ((cbits & 0x1c) == 0x04)
104 sprintf(str, "SDCCH/4(%u)", cbits & 0x03);
105 else if ((cbits & 0x18) == 0x08)
106 sprintf(str, "SDCCH/8(%u)", cbits & 0x07);
107 else if (cbits == 0x10)
108 sprintf(str, "BCCH");
109 else if (cbits == 0x11)
110 sprintf(str, "RACH");
111 else if (cbits == 0x12)
112 sprintf(str, "PCH/AGCH");
114 sprintf(str, "UNKNOWN");
119 /* Receive L1CTL_DATA_IND (Data Indication from L1) */
120 static int rx_ph_data_ind(struct osmocom_ms *ms, struct msgb *msg)
122 struct l1ctl_info_dl *dl, dl_cpy;
123 struct l1ctl_data_ind *ccch;
124 struct lapdm_entity *le;
125 uint8_t chan_type, chan_ts, chan_ss;
126 uint8_t gsmtap_chan_type;
129 if (msgb_l3len(msg) < sizeof(*ccch)) {
130 fprintf(stderr, "MSG too short Data Ind: %u\n", msgb_l3len(msg));
134 dl = (struct l1ctl_info_dl *) msg->l1h;
135 msg->l2h = dl->payload;
136 ccch = (struct l1ctl_data_ind *) msg->l2h;
138 gsm_fn2gsmtime(&tm, ntohl(dl->frame_nr));
139 rsl_dec_chan_nr(dl->chan_nr, &chan_type, &chan_ss, &chan_ts);
140 printf("%s (%.4u/%.2u/%.2u) %s\n",
141 chan_nr2string(dl->chan_nr), tm.t1, tm.t2, tm.t3,
142 hexdump(ccch->data, sizeof(ccch->data)));
144 /* send CCCH data via GSMTAP */
145 gsmtap_chan_type = chantype_rsl2gsmtap(chan_type, dl->link_id);
146 gsmtap_sendmsg(dl->band_arfcn, chan_ts, gsmtap_chan_type, chan_ss,
147 tm.fn, dl->rx_level-110, dl->snr, ccch->data, sizeof(ccch->data));
149 /* determine LAPDm entity based on SACCH or not */
150 if (dl->link_id & 0x40)
151 le = &ms->lapdm_acch;
153 le = &ms->lapdm_dcch;
154 /* make local stack copy of l1ctl_info_dl, as LAPDm will overwrite skb hdr */
155 memcpy(&dl_cpy, dl, sizeof(dl_cpy));
157 /* pull the L1 header from the msgb */
158 msgb_pull(msg, msg->l2h - (msg->l1h-sizeof(struct l1ctl_hdr)));
161 /* send it up into LAPDm */
162 l2_ph_data_ind(msg, le, &dl_cpy);
167 /* Transmit L1CTL_DATA_REQ */
168 int tx_ph_data_req(struct osmocom_ms *ms, struct msgb *msg,
169 uint8_t chan_nr, uint8_t link_id)
171 struct l1ctl_hdr *l1h;
172 struct l1ctl_info_ul *l1i_ul;
173 uint8_t chan_type, chan_ts, chan_ss;
174 uint8_t gsmtap_chan_type;
176 printf("tx_ph_data_req(%s)\n", hexdump(msg->l2h, msgb_l2len(msg)));
178 if (msgb_l2len(msg) > 23) {
179 printf("L1 cannot handle message length > 23 (%u)\n", msgb_l2len(msg));
182 } else if (msgb_l2len(msg) < 23)
183 printf("L1 message length < 23 (%u) doesn't seem right!\n", msgb_l2len(msg));
185 /* send copy via GSMTAP */
186 rsl_dec_chan_nr(chan_nr, &chan_type, &chan_ss, &chan_ts);
187 gsmtap_chan_type = chantype_rsl2gsmtap(chan_type, link_id);
188 gsmtap_sendmsg(0|0x4000, chan_ts, gsmtap_chan_type, chan_ss,
189 0, 127, 255, msg->l2h, msgb_l2len(msg));
191 /* prepend uplink info header */
192 l1i_ul = (struct l1ctl_info_ul *) msgb_push(msg, sizeof(*l1i_ul));
194 l1i_ul->chan_nr = chan_nr;
195 l1i_ul->link_id = link_id;
197 /* FIXME: where to get this from? */
198 l1i_ul->tx_power = 0;
200 /* prepend l1 header */
201 msg->l1h = msgb_push(msg, sizeof(*l1h));
202 l1h = (struct l1ctl_hdr *) msg->l1h;
203 l1h->msg_type = L1CTL_DATA_REQ;
205 return osmo_send_l1(ms, msg);
208 /* Receive L1CTL_RESET */
209 static int rx_l1_reset(struct osmocom_ms *ms)
212 struct l1ctl_sync_new_ccch_req *req;
214 msg = osmo_l1_alloc(L1CTL_NEW_CCCH_REQ);
218 printf("Layer1 Reset.\n");
219 req = (struct l1ctl_sync_new_ccch_req *) msgb_put(msg, sizeof(*req));
220 req->band_arfcn = osmo_make_band_arfcn(ms);
222 return osmo_send_l1(ms, msg);
225 /* Transmit L1CTL_RACH_REQ */
226 int tx_ph_rach_req(struct osmocom_ms *ms)
229 struct l1ctl_info_ul *ul;
230 struct l1ctl_rach_req *req;
231 static uint8_t i = 0;
233 msg = osmo_l1_alloc(L1CTL_RACH_REQ);
237 printf("RACH Req.\n");
238 ul = (struct l1ctl_info_ul *) msgb_put(msg, sizeof(*ul));
239 req = (struct l1ctl_rach_req *) msgb_put(msg, sizeof(*req));
242 return osmo_send_l1(ms, msg);
245 /* Transmit L1CTL_DM_EST_REQ */
246 int tx_ph_dm_est_req(struct osmocom_ms *ms, uint16_t band_arfcn, uint8_t chan_nr)
249 struct l1ctl_info_ul *ul;
250 struct l1ctl_dm_est_req *req;
252 msg = osmo_l1_alloc(L1CTL_DM_EST_REQ);
256 printf("Tx Dedic.Mode Est Req (arfcn=%u, chan_nr=0x%02x)\n",
257 band_arfcn, chan_nr);
258 ul = (struct l1ctl_info_ul *) msgb_put(msg, sizeof(*ul));
259 ul->chan_nr = chan_nr;
261 ul->tx_power = 0; /* FIXME: initial TX power */
262 req = (struct l1ctl_dm_est_req *) msgb_put(msg, sizeof(*req));
263 req->band_arfcn = band_arfcn;
265 return osmo_send_l1(ms, msg);
268 /* Receive incoming data from L1 using L1CTL format */
269 int l1ctl_recv(struct osmocom_ms *ms, struct msgb *msg)
272 struct l1ctl_hdr *l1h;
273 struct l1ctl_info_dl *dl;
275 if (msgb_l2len(msg) < sizeof(*dl)) {
276 fprintf(stderr, "Short Layer2 message: %u\n", msgb_l2len(msg));
280 l1h = (struct l1ctl_info_dl *) msg->l1h;
282 /* move the l1 header pointer to point _BEHIND_ l1ctl_hdr,
283 as the l1ctl header is of no interest to subsequent code */
284 msg->l1h = l1h->data;
286 switch (l1h->msg_type) {
287 case L1CTL_NEW_CCCH_RESP:
288 rc = rx_l1_ccch_resp(ms, msg);
291 rc = rx_ph_data_ind(ms, msg);
294 rc = rx_l1_reset(ms);
297 fprintf(stderr, "Unknown MSG: %u\n", l1h->msg_type);