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-rw-r--r--src/osmo-bts-virtual/l1_if.c160
-rw-r--r--src/osmo-bts-virtual/scheduler_virtbts.c62
2 files changed, 170 insertions, 52 deletions
diff --git a/src/osmo-bts-virtual/l1_if.c b/src/osmo-bts-virtual/l1_if.c
index e663767e..2de50822 100644
--- a/src/osmo-bts-virtual/l1_if.c
+++ b/src/osmo-bts-virtual/l1_if.c
@@ -28,6 +28,7 @@
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/gsmtap.h>
#include <osmocom/gsm/protocol/gsm_08_58.h>
+#include <osmocom/gsm/rsl.h>
#include <osmo-bts/logging.h>
#include <osmo-bts/bts.h>
@@ -42,6 +43,82 @@
#include "virtual_um.h"
+extern int vbts_sched_start(struct gsm_bts *bts);
+
+/*! \brief convert GSMTAP channel type to RSL channel number
+ * \param[in] gsmtap_chantype GSMTAP channel type
+ * \param[out] rsl_chantype rsl channel type
+ * \param[out] rsl_chantype rsl link id
+ *
+ * Mapping from gsmtap channel:
+ * GSMTAP_CHANNEL_UNKNOWN * 0x00
+ * GSMTAP_CHANNEL_BCCH * 0x01
+ * GSMTAP_CHANNEL_CCCH * 0x02
+ * GSMTAP_CHANNEL_RACH * 0x03
+ * GSMTAP_CHANNEL_AGCH * 0x04
+ * GSMTAP_CHANNEL_PCH * 0x05
+ * GSMTAP_CHANNEL_SDCCH * 0x06
+ * GSMTAP_CHANNEL_SDCCH4 * 0x07
+ * GSMTAP_CHANNEL_SDCCH8 * 0x08
+ * GSMTAP_CHANNEL_TCH_F * 0x09
+ * GSMTAP_CHANNEL_TCH_H * 0x0a
+ * GSMTAP_CHANNEL_PACCH * 0x0b
+ * GSMTAP_CHANNEL_CBCH52 * 0x0c
+ * GSMTAP_CHANNEL_PDCH * 0x0d
+ * GSMTAP_CHANNEL_PTCCH * 0x0e
+ * GSMTAP_CHANNEL_CBCH51 * 0x0f
+ * to rsl channel type:
+ * RSL_CHAN_NR_MASK * 0xf8
+ * RSL_CHAN_NR_1 * * 0x08
+ * RSL_CHAN_Bm_ACCHs * 0x08
+ * RSL_CHAN_Lm_ACCHs * 0x10
+ * RSL_CHAN_SDCCH4_ACCH * 0x20
+ * RSL_CHAN_SDCCH8_ACCH * 0x40
+ * RSL_CHAN_BCCH * * 0x80
+ * RSL_CHAN_RACH * * 0x88
+ * RSL_CHAN_PCH_AGCH * 0x90
+ * RSL_CHAN_OSMO_PDCH * 0xc0
+ * and logical channel link id:
+ * LID_SACCH * * 0x40
+ * LID_DEDIC * * 0x00
+ *
+ * TODO: move this to a library used by both ms and bts virt um
+ */
+void chantype_gsmtap2rsl(uint8_t gsmtap_chantype, uint8_t *rsl_chantype, uint8_t *link_id)
+{
+ // switch case with removed acch flag
+ switch (gsmtap_chantype & ~GSMTAP_CHANNEL_ACCH & 0xff) {
+ case GSMTAP_CHANNEL_TCH_F: // TCH/F, FACCH/F
+ *rsl_chantype = RSL_CHAN_Bm_ACCHs;
+ break;
+ case GSMTAP_CHANNEL_TCH_H: // TCH/H, FACCH/H
+ *rsl_chantype = RSL_CHAN_Lm_ACCHs;
+ break;
+ case GSMTAP_CHANNEL_SDCCH4: // SDCCH/4
+ *rsl_chantype = RSL_CHAN_SDCCH4_ACCH;
+ break;
+ case GSMTAP_CHANNEL_SDCCH8: // SDCCH/8
+ *rsl_chantype = RSL_CHAN_SDCCH8_ACCH;
+ break;
+ case GSMTAP_CHANNEL_BCCH: // BCCH
+ *rsl_chantype = RSL_CHAN_BCCH;
+ break;
+ case GSMTAP_CHANNEL_RACH: // RACH
+ *rsl_chantype = RSL_CHAN_RACH;
+ break;
+ case GSMTAP_CHANNEL_PCH: // PCH
+ case GSMTAP_CHANNEL_AGCH: // AGCH
+ *rsl_chantype = RSL_CHAN_PCH_AGCH;
+ break;
+ case GSMTAP_CHANNEL_PDCH:
+ *rsl_chantype = GSMTAP_CHANNEL_PDCH;
+ break;
+ }
+
+ *link_id = gsmtap_chantype & GSMTAP_CHANNEL_ACCH ? LID_SACCH : LID_DEDIC;
+
+}
+
/**
* Callback to handle incoming messages from the MS.
* The incoming message should be GSM_TAP encapsulated.
@@ -49,46 +126,81 @@
*/
static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
{
- struct gsmtap_hdr *gh;
- struct osmo_phsap_prim l1sap;
+ struct gsmtap_hdr *gh = msgb_l1(msg);
+ uint32_t fn = ntohl(gh->frame_number); // frame number of the rcv msg
+ uint16_t arfcn = ntohs(gh->arfcn); // arfcn of the cell we currently camp on
+ uint8_t gsmtap_chantype = gh->sub_type; // gsmtap channel type
+ uint8_t signal_dbm = gh->signal_dbm; // signal strength, 63 is best
+ uint8_t snr = gh->snr_db; // signal noise ratio, 63 is best
+ uint8_t subslot = gh->sub_slot; // multiframe subslot to send msg in (tch -> 0-26, bcch/ccch -> 0-51)
+ uint8_t timeslot = gh->timeslot; // tdma timeslot to send in (0-7)
+ uint8_t rsl_chantype; // rsl chan type (8.58, 9.3.1)
+ uint8_t link_id; // rsl link id tells if this is an ssociated or dedicated link
+ uint8_t chan_nr; // encoded rsl channel type, timeslot and mf subslot
struct phy_link *plink = (struct phy_link *)vui->priv;
// TODO: is there more than one physical instance? Where do i get the corresponding pinst number? Maybe gsmtap_hdr->antenna?
struct phy_instance *pinst = phy_instance_by_num(plink, 0);
+ struct l1sched_trx *l1t = &pinst->u.virt.sched;
+ struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, timeslot);
+ struct osmo_phsap_prim l1sap;
memset(&l1sap, 0, sizeof(l1sap));
- msg->l1h = msgb_data(msg);
+ // get rid of l1 gsmtap hdr
msg->l2h = msgb_pull(msg, sizeof(*gh));
- gh = msgb_l1(msg);
- switch (gh->sub_type) {
- case GSMTAP_CHANNEL_RACH:
+ // convert gsmtap chan to rsl chan and link id
+ chantype_gsmtap2rsl(gsmtap_chantype, &rsl_chantype, &link_id);
+ chan_nr = rsl_enc_chan_nr(rsl_chantype, subslot, timeslot);
+ // switch case with removed acch flag
+ switch (gsmtap_chantype & ~GSMTAP_CHANNEL_ACCH & 0xff) {
+ case GSMTAP_CHANNEL_RACH:
// generate primitive for upper layer
+ // see 04.08 - 3.3.1.3.1: the IMMEDIATE_ASSIGNMENT coming back from the network has to be
+ // sent with the same ra reference as in the CHANNEL_REQUEST that was received
osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_PH_RACH,
PRIM_OP_INDICATION,
msg);
- l1sap.u.rach_ind.chan_nr = RSL_CHAN_RACH;
- // get the random access content
- l1sap.u.rach_ind.ra = msgb_pull_u8(msg);
- l1sap.u.rach_ind.fn = ntohl(gh->frame_number);
+
+ l1sap.u.rach_ind.chan_nr = chan_nr;
+ // TODO: why is ra her 16bits long instead of 8 like in the reference 04.08 - 9.1.8 - Channel request?
+ l1sap.u.rach_ind.ra = msgb_pull_u8(msg); // directly after gh hdr comes ra
+ l1sap.u.rach_ind.acc_delay = 0; // probably not used in virt um
+ l1sap.u.rach_ind.is_11bit = 0; // We dont use that
+ l1sap.u.rach_ind.fn = fn;
+ l1sap.u.rach_ind.burst_type = GSM_L1_BURST_TYPE_NONE; // FIXME: what comes here
break;
- case GSMTAP_CHANNEL_SDCCH:
case GSMTAP_CHANNEL_SDCCH4:
+ // TODO: check if separate handling is needed
case GSMTAP_CHANNEL_SDCCH8:
- // TODO: implement channel handling
- break;
+ // TODO: check if separate handling is needed
case GSMTAP_CHANNEL_TCH_F:
- // TODO: implement channel handling
- break;
+ // TODO: check if separate handling is needed
case GSMTAP_CHANNEL_TCH_H:
- // TODO: implement channel handling
+ // check if associated control flag is set
+ if(gsmtap_chantype & GSMTAP_CHANNEL_ACCH) {
+ // TODO: check if handling is different for ACCH
+ // TODO: does FACCH need special handling?
+ }
+ osmo_prim_init(&l1sap.oph, SAP_GSM_PH, PRIM_PH_DATA,
+ PRIM_OP_INDICATION, msg);
+
+ l1sap.u.data.chan_nr = chan_nr;
+ l1sap.u.data.link_id = link_id;
+ l1sap.u.data.fn = fn;
+ l1sap.u.data.rssi = 0; // Radio Signal Strength Indicator. Best -> 0.
+ l1sap.u.data.ber10k = 0; // Bit Error Rate in 0.01%. Best -> 0.
+ l1sap.u.data.ta_offs_qbits = 0; // Burst time of arrival in quarter bits. Probably used for Timing Advance calc. Best -> 0.
+ l1sap.u.data.lqual_cb = 10 * signal_dbm; // Link quality in centiBel = 10 * db.
+ l1sap.u.data.pdch_presence_info = PRES_INFO_UNKNOWN;
break;
case GSMTAP_CHANNEL_AGCH:
case GSMTAP_CHANNEL_PCH:
case GSMTAP_CHANNEL_BCCH:
LOGP(LOGL_NOTICE, DL1P,
- "Ignore incoming msg - channel type downlink only!");
+ "Ignore incoming msg - channel type downlink only!\n");
goto nomessage;
+ case GSMTAP_CHANNEL_SDCCH:
case GSMTAP_CHANNEL_CCCH:
case GSMTAP_CHANNEL_PACCH:
case GSMTAP_CHANNEL_PDCH:
@@ -96,21 +208,21 @@ static void virt_um_rcv_cb(struct virt_um_inst *vui, struct msgb *msg)
case GSMTAP_CHANNEL_CBCH51:
case GSMTAP_CHANNEL_CBCH52:
LOGP(LOGL_NOTICE, DL1P,
- "Ignore incoming msg - channel type not supported!");
+ "Ignore incoming msg - channel type not supported!\n");
goto nomessage;
default:
LOGP(LOGL_NOTICE, DL1P,
- "Ignore incoming msg - channel type unknown.");
+ "Ignore incoming msg - channel type unknown.\n");
goto nomessage;
}
- /* forward primitive */
+ /* forward primitive, forwarded msg will not be freed */
l1sap_up(pinst->trx, &l1sap);
- DEBUGP(DL1P, "Message forwarded to layer 2.");
+ DEBUGP(DL1P, "Message forwarded to layer 2.\n");
return;
// handle memory deallocation
- nomessage: free(msg);
+ nomessage: talloc_free(msg);
}
/* called by common part once OML link is established */
@@ -333,9 +445,9 @@ int bts_model_l1sap_down(struct gsm_bts_trx *trx, struct osmo_phsap_prim *l1sap)
break;
}
/* activate dedicated channel */
- trx_sched_set_lchan(sched, chan_nr, 0x00, 1);
+ trx_sched_set_lchan(sched, chan_nr, LID_DEDIC, 1);
/* activate associated channel */
- trx_sched_set_lchan(sched, chan_nr, 0x40, 1);
+ trx_sched_set_lchan(sched, chan_nr, LID_SACCH, 1);
/* set mode */
trx_sched_set_mode(sched, chan_nr,
lchan->rsl_cmode,
diff --git a/src/osmo-bts-virtual/scheduler_virtbts.c b/src/osmo-bts-virtual/scheduler_virtbts.c
index 1e9630e0..9d4a211a 100644
--- a/src/osmo-bts-virtual/scheduler_virtbts.c
+++ b/src/osmo-bts-virtual/scheduler_virtbts.c
@@ -44,50 +44,57 @@
#include "virtual_um.h"
-extern void *tall_bts_ctx;
-
/**
* Send a message over the virtual um interface.
* This will at first wrap the msg with a gsmtap header and then write it to the declared multicast socket.
+ * TODO: we might want to remove unused argument uint8_t tn
*/
static void tx_to_virt_um(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
enum trx_chan_type chan, struct msgb *msg)
{
const struct trx_chan_desc *chdesc = &trx_chan_desc[chan];
- uint8_t chan_type, timeslot, subslot, signal_dbm, signal_snr;
- rsl_dec_chan_nr(chdesc->chan_nr, &chan_type, &subslot, &timeslot);
- if (chan_type == RSL_CHAN_PCH_AGCH) {
- if (L1SAP_FN2CCCHBLOCK(fn) >= 1) {
- chan_type = GSMTAP_CHANNEL_PCH;
- } else {
- chan_type = GSMTAP_CHANNEL_AGCH;
- }
+ struct msgb *outmsg; // msg to send with gsmtap header prepended
+ uint16_t arfcn = l1t->trx->arfcn; // arfcn of the tranceiver the message is send with
+ uint8_t signal_dbm = 63; // signal strength, 63 is best
+ uint8_t snr = 63; // signal noise ratio, 63 is best
+ uint8_t *data = msgb_l2(msg); // data to transmit (whole message without l1 header)
+ uint8_t data_len = msgb_l2len(msg); // length of data
+ uint8_t rsl_chantype; // rsl chan type (8.58, 9.3.1)
+ uint8_t subslot; // multiframe subslot to send msg in (tch -> 0-26, bcch/ccch -> 0-51)
+ uint8_t timeslot; // tdma timeslot to send in (0-7)
+ uint8_t gsmtap_chantype; // the gsmtap channel
+
+ rsl_dec_chan_nr(chdesc->chan_nr, &rsl_chantype, &subslot, &timeslot);
+ // in osmocom, agch is only sent on ccch block 0. no idea why. this seems to cause false gsmtap channel types for agch and pch.
+ if (rsl_chantype == RSL_CHAN_PCH_AGCH && L1SAP_FN2CCCHBLOCK(fn) == 0) {
+ gsmtap_chantype = GSMTAP_CHANNEL_PCH;
} else {
- chan_type = chantype_rsl2gsmtap(chan_type, chdesc->link_id); // the logical channel type
+ gsmtap_chantype = chantype_rsl2gsmtap(rsl_chantype,
+ chdesc->link_id); // the logical channel type
}
- //uint8_t timeslot = tn; // indicates the physical channel
- //uint8_t subslot = 0; // indicates the logical channel subslot on the physical channel FIXME: calculate
- signal_dbm = 63; // the signal strength is not needed in virt phy
- signal_snr = 40; // the signal to noice ratio is not needed in virt phy
- uint8_t *data = msgb_l2(msg); // data bits to transmit (whole message without l1 header)
- uint8_t data_len = msgb_l2len(msg);
- struct msgb *outmsg;
+
+ outmsg = gsmtap_makemsg(l1t->trx->arfcn, timeslot, gsmtap_chantype,
+ subslot, fn, signal_dbm, snr, data, data_len);
// TODO: encrypt and encode message data
- outmsg = gsmtap_makemsg(l1t->trx->arfcn, timeslot, chan_type, subslot,
- fn, signal_dbm, signal_snr, data, data_len);
if (outmsg) {
struct phy_instance *pinst = trx_phy_instance(l1t->trx);
- struct virt_um_inst *virt_um = pinst->phy_link->u.virt.virt_um;
- if (virt_um_write_msg(virt_um, outmsg) == -1) {
- struct gsmtap_hdr *gh = (struct gsmtap_hdr *)msgb_data(
- outmsg);
+ struct gsmtap_hdr *gh = msgb_data(outmsg);
+ if (virt_um_write_msg(pinst->phy_link->u.virt.virt_um, outmsg)
+ == -1) {
LOGP(DL1C, LOGL_ERROR,
- "Message could not be written to virtual UM! arfcn = %u gsmtap_chan=%u fn=%u ts=%u\n",
- gh->arfcn, gh->type, gh->frame_number,
- gh->timeslot);
+ "Gsmtap msg could not send to virt um - (arfcn=%u, type=%u, subtype=%u, timeslot=%u, subslot=%u)\n",
+ gh->arfcn, gh->type, gh->sub_type,
+ gh->timeslot, gh->sub_slot);
+ } else {
+ DEBUGP(DL1C,
+ "Sending gsmtap msg to virt um - (arfcn=%u, type=%u, subtype=%u, timeslot=%u, subslot=%u)\n",
+ gh->arfcn, gh->type, gh->sub_type,
+ gh->timeslot, gh->sub_slot);
}
+ } else {
+ LOGP(DL1C, LOGL_ERROR, "Gsmtap msg could not be created!\n");
}
/* free message */
@@ -128,7 +135,6 @@ ubit_t *tx_data_fn(struct l1sched_trx *l1t, uint8_t tn, uint32_t fn,
return NULL;
/* get mac block from queue */
- // what queue is that and who does fill it?
msg = _sched_dequeue_prim(l1t, tn, fn, chan);
if (msg)
goto got_msg;
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-26 22:53:18 +0000