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WIP V110 

Change-Id: I5716bd6fd0201ee7a7a29e72f775972cd374082f
This commit is contained in:
Harald Welte 2023-03-14 20:33:51 +01:00
parent 43c61db980
commit a700be4f14
1 changed files with 330 additions and 0 deletions
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330
src/isdn/v110.c
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@ -30,6 +30,8 @@
#include <errno.h>
#include <osmocom/core/bits.h>
#include <osmocom/core/utils.h>
#include <osmocom/core/fsm.h>
#include <osmocom/isdn/v110.h>
@ -581,3 +583,331 @@ int osmo_v110_sync_ra1_ir_to_user(enum osmo_v100_sync_ra1_rate rate, ubit_t *d_o
return osmo_v110_sync_ra1_def[rate].adapt_ir_to_user(d_out, out_len, fr);
}
/*********************************************************************************
* V.110 TERMINAL ADAPTER FSMs
*********************************************************************************/
enum v110_ta_state {
V110_TA_S_IDLE_READY, /* Idle (or ready) state */
V110_TA_S_CON_TA_LINE, /* Connect TA to line state */
V110_TA_S_DATA_TRANSFER, /* Data transfer state */
V110_TA_S_RESYNCING, /* Re-synchronizing state */
};
enum v110_ta_event {
V110_TA_E_RX_FRAME_IND, /* Received V.110 frame indication */
V110_TA_E_TX_FRAME_RTS, /* V.110 frame Ready-to-send indication */
};
static const struct value_string v110_ta_event_names[] = {
{ V110_TA_E_RX_FRAME_IND, "RX_FRAME_IND" },
{ V110_TA_E_TX_FRAME_RTS, "TX_FRAME_RTS" },
{ 0, NULL }
};
enum v110_ta_tx_d_bit_mode {
V110_TA_TX_FRAME_ALL_ONE,
V110_TA_TX_FRAME_ALL_ZERO,
V110_TA_TX_FRAME_FROM_DTE,
};
struct v110_ta_state {
/* V.24 status flags shared between DTE (user) and DCE (TA, us) */
v24_flagmask v24_flags;
struct {
/* is end-to-end flow-control enabled or not? */
bool end_to_end_flowctrl;
/* synchronous user rate */
enum osmo_v100_sync_ra1_rate rate;
} cfg;
struct {
/* what kind of D-bits to transmit in V.110 frames */
enum v110_ta_tx_d_bit_mode d_bit_mode;
/* what to put in S-bits of transmitted V.110 frames (true = ON) */
bool s_bits;
/* what to put in X-bits of transmitted V.110 frames (true = OFF) */
bool x_bits;
/* what to put in E-bits of transmitted V.110 frames */
ubit_t e_bits[MAX_E_BITS];
} tx;
struct {
enum v11o_ta_tx_d_bit_mode bit_mode;
} rx;
};
/* build one V.110 frame to transmit */
static void v110_ta_build_frame(struct osmo_v110_decoded_frame *out, struct osmo_fsm_inst *fi)
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
/* D-bits */
switch (ts->tx.d_bit_mode) {
case V110_TA_TX_FRAME_ALL_ONE:
memset(out->d_bits, 1, sizeof(out->d_bits));
break;
case V110_TA_TX_FRAME_ALL_ZERO:
memset(out->d_bits, 0, sizeof(out->d_bits));
break;
case V110_TA_TX_FRAME_FROM_DTE:
//FIXME: retrieve user bits */
rc = osmo_v110_sync_ra1_user_to_ir(ts->cfg.rate, out, user_bits, num_user_bits);
OSMO_ASSERT(rc == 0);
break;
};
/* E-bits */
memcpy(out->e_bits, ts->tx.e_bits, sizeof(out->e_bits));
/* S-bits */
if (ts->tx.s_bits == true)
memset(out->s_bits, 0, sizeof(out->s_bits));
else
memset(out->s_bits, 1, sizeof(out->s_bits));
/* X-bits */
if (ts->tx.x_bits == true)
memset(out->x_bits, 0, sizeof(out->x_bits));
else
memset(out->x_bits, 1, sizeof(out->x_bits));
}
static void v24_flags_updated(struct osmo_fsm_inst *fi)
{
/* FIXME: somehow notify the USART about it */
}
/* ITU-T V.110 Section 7.1.1 */
static void v110fsm_ta_idle_ready_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state);
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
/* E4 .. E7 bits (lower 3 bits are generated by v110 frame encoder) */
memset(ts->tx.e_bits+3, 1, 4);
ts->user_data_cunk_bitlen = osmo_v110_sync_ra1_get_user_data_chunk_bitlen(ts->cfg.rate);
/* 7.1.1.2 During the idle (or ready) state the TA will transmit continuous binary 1s into the B-channel */
/* 7.1.1.3 During the idle (or ready) state the TA (DCE) will transmit the following toward the DTE: * */
/* - 104: continuous binary 1*/
ts->rx.bit_mode = V110_TA_TX_FRAME_ALL_ONE;
/* - 107, 106, 109 = OFF */
V24_FLAGMASK_SET_OFF(ts->v24_flags, OSMO_V24_C_106);
V24_FLAGMASK_SET_OFF(ts->v24_flags, OSMO_V24_C_107);
V24_FLAGMASK_SET_OFF(ts->v24_flags, OSMO_V24_C_109);
v24_flags_updated(fi);
}
/* ITU-T V.110 Section 7.1.1 */
static void v110fsm_ta_idle_ready(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
const struct osmo_v110_decoded_frame *fr = NULL;
int rc;
switch (event) {
case V110_TA_E_RX_FRAME_IND:
fr = data;
rc = osmo_v110_sync_ra1_ir_to_user(ts->cfg.rate, d_out, out_len, fr);
break;
case V110_TA_E_TX_FRAME_RTS:
/* transmit continuous binary 1 to B channels */
break;
case V110_TA_E_SWITCH_TO_DATA_MODE:
/* When the TA is to be switched to the data mode, circuit 108 must be ON */
if (V24_FLAGMASK_IS_ON(ts->v24_flags, OSMO_V24_C_108_2)) {
/* 7.12.2: Start timer T1 when switching to CON_TA_LINE */
osmo_fsm_inst_state_chg(fi, V110_TA_S_CON_TA_LINE, 10, 1);
}
break;
default:
OSMO_ASSERT(0);
}
}
/* ITU-t V.110 Section 7.1.2 */
static void v110fsm_ta_connect_to_line_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state);
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
/* frame sync pattern as per 5.1.3.1 / 5.2.1 */
FIXME
/* data bits: binary 1 */
ts->tx.d_bit_mode = V110_TA_TX_FRAME_ALL_ONE;
/* S = OFF, X = OFF (ON = binary 0; OFF = binary 1) */
ts->tx.s_bits = false;
ts->tx.x_bits = false;
/* onenter: T1 has been started */
OSMO_ASSERT(fi->T = 1);
}
static bool all_bits_are(const ubit_t *in, ubit_t cmp, size_t in_len)
{
for (unsigned int i = 0; i < in_len; i++) {
if (in[i] != cmp)
return false;
}
return true;
}
#define ARRAY_ALL_BITS_ONE(arr) all_bits_are((arr), 1, sizeof(arr))
#define ARRAY_ALL_BITS_ZERO(arr) all_bits_are((arr), 0, sizeof(arr))
/* ITU-t V.110 Section 7.1.2 */
static void v110fsm_ta_connect_ta_to_line(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
struct osmo_v110_decoded_frame *fr = NULL;
switch (event) {
case V110_TA_E_RX_FRAME_IND:
fr = data;
if (ARRAY_ALL_BITS_ZERO(fr->s_bits) && ARRAY_ALL_BITS_ZERO(fr->x_bits)) {
/* 7.1.2.4 When the receiver recognizes that the status of bits S and X are in the ON
* condition, it will perform the following functions: */
/* a) Turn ON circuit 107 toward the DTE and stop timer T1. */
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_107);
/* b) Then, circuit 103 may be connected to the data bits in the frame; however, the
* DTE must maintain a binary 1 condition on circuit 103 until circuit 106 is turned
* ON in the next portion of the sequence. */
/* c) Turn ON circuit 109 and connect the data bits to circuit 104. */
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_109);
/* d) After an interval of N bits (see 6.3), it will turn ON circuit 106. */
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_106);
v24_flags_updated(fi);
/* Circuit 106 transitioning from OFF to ON will cause the transmitted data to
* transition from binary 1 to the data mode. */
osmo_fsm_inst_state_chg(fi, V110_TA_S_DATA_XFER, 0, 0);
rc = osmo_v110_sync_ra1_ir_to_user(ts->cfg.rate, d_out, out_len, fr);
}
break;
case V110_TA_E_TX_FRAME_RTS:
fr = data;
v110_ta_build_frame(fr, fi);
break;
case V110_TA_E_RX_SYNC_IND:
/* 7.1.2.3 When the receiver recognizes the frame synchronization pattern, it causes the S-
* and X-bits in the transmitted frames to be turned ON (provided that circuit 108 is ON). */
if (V24_FLAGMASK_IS_ON(ts->v24_flags, OSMO_V24_C_108_2)) {
ts->tx.s_bits = true;
ts->tx.x_bits = true;
}
break;
default:
OSMO_ASSERT(0);
}
}
/* ITU-t V.110 Section 7.1.3 */
static void v110fsm_ta_data_transfer_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
ts->tx.d_bit_mode = V110_TA_TX_FRAME_FROM_DTE;
/* 7.1.3.1 a): 105, 107, 108/1, 108/2 and 109 are in the ON condition */
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_105);
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_107);
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_108_1);
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_108_2);
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_109);
/* 7.1.3.1 c): 133 (when implemented) and 106 are in the ON condition unless local out-of-band
flow control is being used, either or both circuits may be in the ON or the OFF condition. */
if (!ts->cfg.end_to_end_flowctrl) {
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_133);
V24_FLAGMASK_SET_ON(ts->v24_flags, OSMO_V24_C_106);
}
v24_flags_updated(fi);
/* 7.1.3.2 While in the data transfer state, the following status bit conditions exist: */
/* a) status bits S in both directions are in the ON condition; */
ts->tx.s_bits = true;
/* b) status bits X in both directions are in the ON condition unless end-to-end flow control is
being used, in which case status bit X in either or both directions may be in the ON or the OFF
condition. */
if (!ts->cfg.end_to_end_flowctrl) {
ts->tx.x_bits = true;
}
}
/* ITU-t V.110 Section 7.1.3 */
static void v110fsm_ta_data_transfer(struct osmo_fsm_inst *fi, uint32_t event, void *data)
{
struct v110_ta_state *ts = (struct v110_ta_state *) fi->priv;
struct osmo_v110_decoded_frame *fr = NULL;
switch (event) {
case V110_TA_E_RX_V24_STATUS_CHG:
/* 7.1.4.1 At the completion of the data transfer phase, the local DTE will indicate a
* disconnect request by turning OFF circuit 108 */
if (V24_FLAGMASK_IS_OFF(ts->v24_flags, OSMO_V24_C_108_2)) {
/* a) the status bits S in the frame toward ISDN will turn OFF, status bits X are kept ON */
ts->tx.s_bits = false;
/* b) circuit 106 will be turned OFF */
V24_FLAGMASK_SET_OFF(ts->v24_flags, OSMO_V24_C_106);
v24_flags_updated(fi);
/* c) the data bits in the frame will be set to binary 0. */
ts->tx.d_bit_mode = V110_TA_TX_FRAME_ALL_ZERO;
/* to guard against the failure of the remote TA to respond to the disconnect request,
* the local TA may start a timer T2 (suggested value 5 s) which is stopped by the
* reception or transmission of any D-channel clearing message (DISCONNECT, RELEASE,
* RELEASE COMPLETE) */
osmo_fsm_inst_state_chg(fi, V110_TA_S_WAIT_DISC_CONF, 5, 2);
}
break;
case V110_TA_E_TX_FRAME_RTS:
fr = data;
v110_ta_build_frame(fr, fi);
break;
case V110_TA_E_RX_FRAME_IND:
fr = data;
rc = osmo_v110_sync_ra1_ir_to_user(ts->cfg.rate, d_out, out_len, fr);
break;
default:
OSMO_ASSERT(0);
}
}
static int v110_ta_timer_cb(struct osmo_fsm_inst *fi)
{
switch (fi->T) {
case 1: /* T1: wait for sync pattern */
break;
case 2: /* T2: wait for response to disconnect */
break;
}
}
static const struct osmo_fsm_state v110_ta_states[] = {
[V110_TA_S_IDLE_READY] = {
.name = "IDLE_READY",
.in_event_mask = S(V110_TA_E_TX_FRAME_RTS),
.out_state_mask = S(V110_TA_S_CON_TA_LINE),
.action = v110fsm_ta_idle_ready,
.ontenter = v110fsm_ta_idle_ready_onenter,
},
[V110_TA_S_CON_TA_LINE] = {
.name = "CONNECT_TA_TO_LINE",
.in_event_mask = S(V110_TA_E_TX_FRAME_RTS),
.out_state_mask = S(V110_TA_S_IDLE_READY) |
S(V110_TA_S_DATA_TRANSFER),
.action = v110fsm_ta_connect_ta_to_line,
.ontenter = v110fsm_ta_connect_ta_to_line_onenter,
},
[V110_TA_S_DATA_TRANSFER] = {
.name = "DATA_TRANSFER",
.in_event_mask = ,
.out_state_mask = ,
.action = v110fsm_ta_data_transfer,
.onenter = v110fsm_ta_data_transfer_onenter,
},
};
static struct osmo_fsm osmo_v110_ta_fsm = {
.name = "V110-TA",
.states = v110_ta_states,
.num_states = ARRAY_SIZE(v110_ta_states),
.allstate_event_mask = FIXME,
.allstate_action = FIXME,
.timer_cb = v110_ta_timer_cb,
.log_subsys = FIXME,
.event_names = v110_ta_event_names,
};