src/host/layer23/src/misc/layer3.c

   1 #include <stdint.h>
   2 #include <errno.h>
   3 #include <stdio.h>
   4
   5 #include <osmocore/msgb.h>
   6 #include <osmocore/rsl.h>
   7 #include <osmocore/tlv.h>
   8 #include <osmocore/gsm48_ie.h>
   9 #include <osmocore/protocol/gsm_04_08.h>
  10
  11 #include <osmocom/bb/common/logging.h>
  12 #include <osmocom/bb/common/lapdm.h>
  13 #include <osmocom/bb/misc/rslms.h>
  14 #include <osmocom/bb/misc/layer3.h>
  15 #include <osmocom/bb/common/osmocom_data.h>
  16 #include <osmocom/bb/common/l1ctl.h>
  17
  18 static struct {
  19         int has_si1;
  20         int ccch_mode;
  21         int ccch_enabled;
  22         int rach_count;
  23         struct gsm_sysinfo_freq cell_arfcns[1024];
  24 } app_state;
  25
  26
  27 static void dump_bcch(struct osmocom_ms *ms, uint8_t tc, const uint8_t *data)
  28 {
  29         struct gsm48_system_information_type_header *si_hdr;
  30         si_hdr = (struct gsm48_system_information_type_header *) data;
  31
  32         /* GSM 05.02 §6.3.1.3 Mapping of BCCH data */
  33         switch (si_hdr->system_information) {
  34         case GSM48_MT_RR_SYSINFO_1:
  35                 fprintf(stderr, "\tSI1");
  36 #ifdef BCCH_TC_CHECK
  37                 if (tc != 0)
  38                         fprintf(stderr, " on wrong TC");
  39 #endif
  40                 if (!app_state.has_si1) {
  41                         struct gsm48_system_information_type_1 *si1 =
  42                                 (struct gsm48_system_information_type_1 *)data;
  43
  44                         gsm48_decode_freq_list(&app_state.cell_arfcns,
  45                                                si1->cell_channel_description,
  46                                                sizeof(si1->cell_channel_description),
  47                                                0xff, 0x01);
  48
  49                         app_state.has_si1 = 1;
  50                 }
  51                 break;
  52         case GSM48_MT_RR_SYSINFO_2:
  53                 fprintf(stderr, "\tSI2");
  54 #ifdef BCCH_TC_CHECK
  55                 if (tc != 1)
  56                         fprintf(stderr, " on wrong TC");
  57 #endif
  58                 break;
  59         case GSM48_MT_RR_SYSINFO_3:
  60                 fprintf(stderr, "\tSI3");
  61 #ifdef BCCH_TC_CHECK
  62                 if (tc != 2 && tc != 6)
  63                         fprintf(stderr, " on wrong TC");
  64 #endif
  65                 if (app_state.ccch_mode == CCCH_MODE_NONE) {
  66                         struct gsm48_system_information_type_3 *si3 =
  67                                 (struct gsm48_system_information_type_3 *)data;
  68
  69                         if (si3->control_channel_desc.ccch_conf == RSL_BCCH_CCCH_CONF_1_C)
  70                                 app_state.ccch_mode = CCCH_MODE_COMBINED;
  71                         else
  72                                 app_state.ccch_mode = CCCH_MODE_NON_COMBINED;
  73
  74                         l1ctl_tx_ccch_mode_req(ms, app_state.ccch_mode);
  75                 }
  76                 break;
  77         case GSM48_MT_RR_SYSINFO_4:
  78                 fprintf(stderr, "\tSI4");
  79 #ifdef BCCH_TC_CHECK
  80                 if (tc != 3 && tc != 7)
  81                         fprintf(stderr, " on wrong TC");
  82 #endif
  83                 break;
  84         case GSM48_MT_RR_SYSINFO_5:
  85                 fprintf(stderr, "\tSI5");
  86                 break;
  87         case GSM48_MT_RR_SYSINFO_6:
  88                 fprintf(stderr, "\tSI6");
  89                 break;
  90         case GSM48_MT_RR_SYSINFO_7:
  91                 fprintf(stderr, "\tSI7");
  92 #ifdef BCCH_TC_CHECK
  93                 if (tc != 7)
  94                         fprintf(stderr, " on wrong TC");
  95 #endif
  96                 break;
  97         case GSM48_MT_RR_SYSINFO_8:
  98                 fprintf(stderr, "\tSI8");
  99 #ifdef BCCH_TC_CHECK
 100                 if (tc != 3)
 101                         fprintf(stderr, " on wrong TC");
 102 #endif
 103                 break;
 104         case GSM48_MT_RR_SYSINFO_9:
 105                 fprintf(stderr, "\tSI9");
 106 #ifdef BCCH_TC_CHECK
 107                 if (tc != 4)
 108                         fprintf(stderr, " on wrong TC");
 109 #endif
 110                 break;
 111         case GSM48_MT_RR_SYSINFO_13:
 112                 fprintf(stderr, "\tSI13");
 113 #ifdef BCCH_TC_CHECK
 114                 if (tc != 4 && tc != 0)
 115                         fprintf(stderr, " on wrong TC");
 116 #endif
 117                 break;
 118         case GSM48_MT_RR_SYSINFO_16:
 119                 fprintf(stderr, "\tSI16");
 120 #ifdef BCCH_TC_CHECK
 121                 if (tc != 6)
 122                         fprintf(stderr, " on wrong TC");
 123 #endif
 124                 break;
 125         case GSM48_MT_RR_SYSINFO_17:
 126                 fprintf(stderr, "\tSI17");
 127 #ifdef BCCH_TC_CHECK
 128                 if (tc != 2)
 129                         fprintf(stderr, " on wrong TC");
 130 #endif
 131                 break;
 132         case GSM48_MT_RR_SYSINFO_2bis:
 133                 fprintf(stderr, "\tSI2bis");
 134 #ifdef BCCH_TC_CHECK
 135                 if (tc != 5)
 136                         fprintf(stderr, " on wrong TC");
 137 #endif
 138                 break;
 139         case GSM48_MT_RR_SYSINFO_2ter:
 140                 fprintf(stderr, "\tSI2ter");
 141 #ifdef BCCH_TC_CHECK
 142                 if (tc != 5 && tc != 4)
 143                         fprintf(stderr, " on wrong TC");
 144 #endif
 145                 break;
 146         case GSM48_MT_RR_SYSINFO_5bis:
 147                 fprintf(stderr, "\tSI5bis");
 148                 break;
 149         case GSM48_MT_RR_SYSINFO_5ter:
 150                 fprintf(stderr, "\tSI5ter");
 151                 break;
 152         default:
 153                 fprintf(stderr, "\tUnknown SI");
 154                 break;
 155         };
 156
 157         fprintf(stderr, "\n");
 158 }
 159
 160
 161 /* send location updating request * (as part of RSLms EST IND /
 162    LAPDm SABME) */
 163 static int gsm48_tx_loc_upd_req(struct osmocom_ms *ms, uint8_t chan_nr)
 164 {
 165         struct msgb *msg = msgb_alloc_headroom(256, 16, "loc_upd_req");
 166         struct gsm48_hdr *gh;
 167         struct gsm48_loc_upd_req *lu_r;
 168
 169         DEBUGP(DMM, "chan_nr=%u\n", chan_nr);
 170
 171         msg->l3h = msgb_put(msg, sizeof(*gh));
 172         gh = (struct gsm48_hdr *) msg->l3h;
 173         gh->proto_discr = GSM48_PDISC_MM;
 174         gh->msg_type = GSM48_MT_MM_LOC_UPD_REQUEST;
 175         lu_r = (struct gsm48_loc_upd_req *) msgb_put(msg, sizeof(*lu_r));
 176         lu_r->type = GSM48_LUPD_IMSI_ATT;
 177         lu_r->key_seq = 0;
 178         /* FIXME: set LAI and CM1 */
 179         /* FIXME: set MI */
 180         lu_r->mi_len = 0;
 181
 182         return rslms_tx_rll_req_l3(ms, RSL_MT_EST_REQ, chan_nr, 0, msg);
 183 }
 184
 185 static int gsm48_rx_imm_ass(struct msgb *msg, struct osmocom_ms *ms)
 186 {
 187         struct gsm48_imm_ass *ia = msgb_l3(msg);
 188         uint8_t ch_type, ch_subch, ch_ts;
 189         int rv;
 190
 191         /* Discard packet TBF assignement */
 192         if (ia->page_mode & 0xf0)
 193                 return 0;
 194
 195         /* FIXME: compare RA and GSM time with when we sent RACH req */
 196
 197         rsl_dec_chan_nr(ia->chan_desc.chan_nr, &ch_type, &ch_subch, &ch_ts);
 198
 199         if (!ia->chan_desc.h0.h) {
 200                 /* Non-hopping */
 201                 uint16_t arfcn;
 202
 203                 arfcn = ia->chan_desc.h0.arfcn_low | (ia->chan_desc.h0.arfcn_high << 8);
 204
 205                 DEBUGP(DRR, "GSM48 IMM ASS (ra=0x%02x, chan_nr=0x%02x, "
 206                         "ARFCN=%u, TS=%u, SS=%u, TSC=%u) ", ia->req_ref.ra,
 207                         ia->chan_desc.chan_nr, arfcn, ch_ts, ch_subch,
 208                         ia->chan_desc.h0.tsc);
 209
 210                 /* request L1 to go to dedicated mode on assigned channel */
 211                 rv = l1ctl_tx_dm_est_req_h0(ms,
 212                         arfcn, ia->chan_desc.chan_nr, ia->chan_desc.h0.tsc);
 213         } else {
 214                 /* Hopping */
 215                 uint8_t maio, hsn, ma_len;
 216                 uint16_t ma[64], arfcn;
 217                 int i, j, k;
 218
 219                 hsn = ia->chan_desc.h1.hsn;
 220                 maio = ia->chan_desc.h1.maio_low | (ia->chan_desc.h1.maio_high << 2);
 221
 222                 DEBUGP(DRR, "GSM48 IMM ASS (ra=0x%02x, chan_nr=0x%02x, "
 223                         "HSN=%u, MAIO=%u, TS=%u, SS=%u, TSC=%u) ", ia->req_ref.ra,
 224                         ia->chan_desc.chan_nr, hsn, maio, ch_ts, ch_subch,
 225                         ia->chan_desc.h1.tsc);
 226
 227                 /* decode mobile allocation */
 228                 ma_len = 0;
 229                 for (i=1, j=0; i<=1024; i++) {
 230                         arfcn = i & 1023;
 231                         if (app_state.cell_arfcns[arfcn].mask & 0x01) {
 232                                 k = ia->mob_alloc_len - (j>>3) - 1;
 233                                 if (ia->mob_alloc[k] & (1 << (j&7))) {
 234                                         ma[ma_len++] = arfcn;
 235                                 }
 236                                 j++;
 237                         }
 238                 }
 239
 240                 /* request L1 to go to dedicated mode on assigned channel */
 241                 rv = l1ctl_tx_dm_est_req_h1(ms,
 242                         maio, hsn, ma, ma_len,
 243                         ia->chan_desc.chan_nr, ia->chan_desc.h1.tsc);
 244         }
 245
 246         DEBUGPC(DRR, "\n");
 247
 248         rv = gsm48_tx_loc_upd_req(ms, ia->chan_desc.chan_nr);
 249
 250         return rv;
 251 }
 252
 253 int gsm48_rx_ccch(struct msgb *msg, struct osmocom_ms *ms)
 254 {
 255         struct gsm48_system_information_type_header *sih = msgb_l3(msg);
 256         int rc = 0;
 257
 258         if (sih->rr_protocol_discriminator != GSM48_PDISC_RR)
 259                 LOGP(DRR, LOGL_ERROR, "PCH pdisc != RR\n");
 260
 261         switch (sih->system_information) {
 262         case GSM48_MT_RR_PAG_REQ_1:
 263         case GSM48_MT_RR_PAG_REQ_2:
 264         case GSM48_MT_RR_PAG_REQ_3:
 265                 /* FIXME: implement decoding of paging request */
 266                 break;
 267         case GSM48_MT_RR_IMM_ASS:
 268                 rc = gsm48_rx_imm_ass(msg, ms);
 269                 break;
 270         default:
 271                 LOGP(DRR, LOGL_NOTICE, "unknown PCH/AGCH type 0x%02x\n",
 272                         sih->system_information);
 273                 rc = -EINVAL;
 274         }
 275
 276         return rc;
 277 }
 278
 279 int gsm48_rx_bcch(struct msgb *msg, struct osmocom_ms *ms)
 280 {
 281         /* FIXME: we have lost the gsm frame time until here, need to store it
 282          * in some msgb context */
 283         //dump_bcch(dl->time.tc, ccch->data);
 284         dump_bcch(ms, 0, msg->l3h);
 285
 286         /* Req channel logic */
 287         if (app_state.ccch_enabled && (app_state.rach_count < 2)) {
 288                 l1ctl_tx_rach_req(ms, app_state.rach_count,
 289                         app_state.ccch_mode == CCCH_MODE_COMBINED ? 27 : 51, 0);
 290                 app_state.rach_count++;
 291         }
 292
 293         return 0;
 294 }
 295
 296 void layer3_app_reset(void)
 297 {
 298         /* Reset state */
 299         app_state.has_si1 = 0;
 300         app_state.ccch_mode = CCCH_MODE_NONE;
 301         app_state.ccch_enabled = 0;
 302         app_state.rach_count = 0;
 303
 304         memset(&app_state.cell_arfcns, 0x00, sizeof(app_state.cell_arfcns));
 305 }
 306