isdn: Add V.110 encoder/decoder
V.110 defines a B-channel protocol for transmission of synchronous and
asynchronous serial data of V-series interfaces via terminal adapters
over ISDN.
Let's add (unoptimized but easy to debug) functions for encoding and
decoding of V.110 frames for various bit-rates.
Related: OS#1572
Change-Id: I1b5fd3847d3bfb0a0f763e0574893962ec699680
diff --git a/src/isdn/v110.c b/src/isdn/v110.c
new file mode 100644
index 0000000..4d13547
--- /dev/null
+++ b/src/isdn/v110.c
@@ -0,0 +1,582 @@
+/* V.110 frames according to ITU-T V.110
+ *
+ * This code implements the following functionality:
+ * - parsing/encoding of osmo_v110_decoded_frame from/to actual 80-bit V.110 frame
+ * - synchronous rate adapting of user bit rate to V.110 D-bits as per Table 6
+ *
+ * It is (at least initially) a very "naive" implementation, as it first and foremost
+ * aims to be functional and correct, rather than efficient in any way. Hence it
+ * operates on unpacked bits (ubit_t, 1 bit per byte), and has various intermediate
+ * representations and indirect function calls. If needed, a more optimized variant
+ * can always be developed later on.
+ */
+
+/* (C) 2022 by Harald Welte <laforge@osmocom.org>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdint.h>
+#include <errno.h>
+
+#include <osmocom/core/bits.h>
+
+#include <osmocom/isdn/v110.h>
+
+/*************************************************************************
+ * V.110 frame decoding/encoding (ubits <-> struct with D/S/X/E bits)
+ *************************************************************************/
+
+/*! Decode a 80-bit V.110 frame present as 80 ubits into a struct osmo_v110_decoded_frame.
+ * \param[out] fr caller-allocated output data structure, filled by this function
+ * \param[in] ra_bits One V.110 frame as 80 unpacked bits.
+ * \param[in] n_bits number of unpacked bits provided in ra_bits
+ * \returns 0 in case of success; negative on error. */
+int osmo_v110_decode_frame(struct osmo_v110_decoded_frame *fr, const ubit_t *ra_bits, size_t n_bits)
+{
+ if (n_bits < 80)
+ return -EINVAL;
+
+ /* X1 .. X2 */
+ fr->x_bits[0] = ra_bits[2 * 8 + 7];
+ fr->x_bits[1] = ra_bits[7 * 8 + 7];
+
+ /* S1, S3, S4, S6, S8, S9 */
+ fr->s_bits[0] = ra_bits[1 * 8 + 7];
+ fr->s_bits[2] = ra_bits[3 * 8 + 7];
+ fr->s_bits[3] = ra_bits[4 * 8 + 7];
+ fr->s_bits[5] = ra_bits[6 * 8 + 7];
+ fr->s_bits[7] = ra_bits[8 * 8 + 7];
+ fr->s_bits[8] = ra_bits[9 * 8 + 7];
+
+ /* E1 .. E7 */
+ memcpy(fr->e_bits, ra_bits + 5 * 8 + 1, 7);
+
+ /* D-bits */
+ memcpy(fr->d_bits + 0 * 6, ra_bits + 1 * 8 + 1, 6);
+ memcpy(fr->d_bits + 1 * 6, ra_bits + 2 * 8 + 1, 6);
+ memcpy(fr->d_bits + 2 * 6, ra_bits + 3 * 8 + 1, 6);
+ memcpy(fr->d_bits + 3 * 6, ra_bits + 4 * 8 + 1, 6);
+
+ memcpy(fr->d_bits + 4 * 6, ra_bits + 6 * 8 + 1, 6);
+ memcpy(fr->d_bits + 5 * 6, ra_bits + 7 * 8 + 1, 6);
+ memcpy(fr->d_bits + 6 * 6, ra_bits + 8 * 8 + 1, 6);
+ memcpy(fr->d_bits + 7 * 6, ra_bits + 9 * 8 + 1, 6);
+
+ return 0;
+}
+
+/*! Encode a struct osmo_v110_decoded_frame into an 80-bit V.110 frame as ubits.
+ * \param[out] ra_bits caller-provided output buffer at leat 80 ubits large
+ * \param[in] n_bits length of ra_bits. Must be at least 80.
+ * \param[in] input data structure
+ * \returns number of bits written to ra_bits */
+int osmo_v110_encode_frame(ubit_t *ra_bits, size_t n_bits, const struct osmo_v110_decoded_frame *fr)
+{
+ if (n_bits < 80)
+ return -ENOSPC;
+
+ /* alignment pattern */
+ memset(ra_bits+0, 0, 8);
+ for (int i = 1; i < 10; i++)
+ ra_bits[i*8] = 1;
+
+ /* X1 .. X2 */
+ ra_bits[2 * 8 + 7] = fr->x_bits[0];
+ ra_bits[7 * 8 + 7] = fr->x_bits[1];
+
+ /* S1, S3, S4, S6, S8, S9 */
+ ra_bits[1 * 8 + 7] = fr->s_bits[0];
+ ra_bits[3 * 8 + 7] = fr->s_bits[2];
+ ra_bits[4 * 8 + 7] = fr->s_bits[3];
+ ra_bits[6 * 8 + 7] = fr->s_bits[5];
+ ra_bits[8 * 8 + 7] = fr->s_bits[7];
+ ra_bits[9 * 8 + 7] = fr->s_bits[8];
+
+ /* E1 .. E7 */
+ memcpy(ra_bits + 5 * 8 + 1, fr->e_bits, 7);
+
+ /* D-bits */
+ memcpy(ra_bits + 1 * 8 + 1, fr->d_bits + 0 * 6, 6);
+ memcpy(ra_bits + 2 * 8 + 1, fr->d_bits + 1 * 6, 6);
+ memcpy(ra_bits + 3 * 8 + 1, fr->d_bits + 2 * 6, 6);
+ memcpy(ra_bits + 4 * 8 + 1, fr->d_bits + 3 * 6, 6);
+
+ memcpy(ra_bits + 6 * 8 + 1, fr->d_bits + 4 * 6, 6);
+ memcpy(ra_bits + 7 * 8 + 1, fr->d_bits + 5 * 6, 6);
+ memcpy(ra_bits + 8 * 8 + 1, fr->d_bits + 6 * 6, 6);
+ memcpy(ra_bits + 9 * 8 + 1, fr->d_bits + 7 * 6, 6);
+
+ return 10 * 8;
+}
+
+/*! Print a encoded V.110 frame in the same table-like structure as the spec.
+ * \param outf output FILE stream to which to dump
+ * \param[in] fr unpacked bits to dump
+ * \param[in] in_len length of unpacked bits available at fr. */
+void osmo_v110_ubit_dump(FILE *outf, const ubit_t *fr, size_t in_len)
+{
+ if (in_len < 80)
+ fprintf(outf, "short input data\n");
+
+ for (unsigned int octet = 0; octet < 10; octet++) {
+ fprintf(outf, "%d\t%d\t%d\t%d\t%d\t%d\t%d\t%d\n",
+ fr[octet * 8 + 0], fr[octet * 8 + 1], fr[octet * 8 + 2], fr[octet * 8 + 3],
+ fr[octet * 8 + 4], fr[octet * 8 + 5], fr[octet * 8 + 6], fr[octet * 8 + 7]);
+ }
+}
+
+/*************************************************************************
+ * RA1 synchronous rate adaptation
+ *************************************************************************/
+
+/* I actually couldn't find any reference as to the value of F(ill) bits */
+#define F 1
+
+/*! Adapt from 6 synchronous 600bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 6.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_600_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ if (in_len != 6)
+ return -EINVAL;
+
+ /* Table 6a / V.110 */
+ fr->e_bits[0] = 1;
+ fr->e_bits[1] = 0;
+ fr->e_bits[2] = 0;
+ for (int i = 0; i < 6; i++)
+ memset(fr->d_bits + i*8, d_in[i], 8);
+
+ return 0;
+}
+
+static int v110_adapt_IR8000_to_600(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ if (out_len < 6)
+ return -ENOSPC;
+
+ if (fr->e_bits[0] != 1 || fr->e_bits[1] != 0 || fr->e_bits[2] != 0)
+ return -EINVAL;
+
+ for (int i = 0; i < 6; i++) {
+ /* we only use one of the bits, not some kind of consistency check or majority vote */
+ d_out[i] = fr->d_bits[i*8];
+ }
+
+ return 6;
+}
+
+/*! Adapt from 12 synchronous 1200bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 12.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_1200_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ if (in_len != 12)
+ return -EINVAL;
+
+ /* Table 6b / V.110 */
+ fr->e_bits[0] = 0;
+ fr->e_bits[1] = 1;
+ fr->e_bits[2] = 0;
+ for (int i = 0; i < 12; i++)
+ memset(fr->d_bits + i*4, d_in[i], 4);
+
+ return 0;
+}
+
+static int v110_adapt_IR8000_to_1200(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ if (out_len < 12)
+ return -ENOSPC;
+
+ if (fr->e_bits[0] != 0 || fr->e_bits[1] != 1 || fr->e_bits[2] != 0)
+ return -EINVAL;
+
+ for (int i = 0; i < 12; i++) {
+ /* we only use one of the bits, not some kind of consistency check or majority vote */
+ d_out[i] = fr->d_bits[i*4];
+ }
+
+ return 12;
+}
+
+/*! Adapt from 24 synchronous 2400bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 24.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_2400_to_IR8000(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ if (in_len != 24)
+ return -EINVAL;
+
+ /* Table 6c / V.110 */
+ fr->e_bits[0] = 1;
+ fr->e_bits[1] = 1;
+ fr->e_bits[2] = 0;
+ for (int i = 0; i < 24; i++) {
+ fr->d_bits[i*2 + 0] = d_in[i];
+ fr->d_bits[i*2 + 1] = d_in[i];
+ }
+
+ return 0;
+}
+
+static int v110_adapt_IR8000_to_2400(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ if (out_len < 24)
+ return -ENOSPC;
+
+ if (fr->e_bits[1] != 1 || fr->e_bits[1] != 1 || fr->e_bits[2] != 0)
+ return -EINVAL;
+
+ for (int i = 0; i < 24; i++) {
+ /* we only use one of the bits, not some kind of consistency check or majority vote */
+ d_out[i] = fr->d_bits[i*2];
+ }
+
+ return 24;
+}
+
+/*! Adapt from 36 synchronous N x 3600bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 36.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx3600_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ int d_idx = 0;
+
+ if (in_len != 36)
+ return -EINVAL;
+
+ /* Table 6d / V.110 */
+ fr->e_bits[0] = 1;
+ fr->e_bits[1] = 0;
+ fr->e_bits[2] = 1;
+
+ memcpy(fr->d_bits + d_idx, d_in + 0, 10); d_idx += 10; /* D1..D10 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 10, 2); d_idx += 2; /* D11..D12 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 12, 2); d_idx += 2; /* D13..D14 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 14, 14); d_idx += 14; /* D15..D28 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 28, 2); d_idx += 2; /* D29..D30 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 30, 2); d_idx += 2; /* D31..D32 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 32, 4); d_idx += 4; /* D33..D36 */
+
+ OSMO_ASSERT(d_idx == 48);
+
+ return 0;
+}
+
+static int v110_adapt_IR_to_Nx3600(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ int d_idx = 0;
+
+ if (out_len < 36)
+ return -ENOSPC;
+
+ if (fr->e_bits[0] != 1 || fr->e_bits[1] != 0 || fr->e_bits[2] != 1)
+ return -EINVAL;
+
+ memcpy(d_out + 0, fr->d_bits + d_idx, 10); d_idx += 10; /* D1..D10 */
+ d_idx += 2;
+ memcpy(d_out + 10, fr->d_bits + d_idx, 2); d_idx += 2; /* D11..D12 */
+ d_idx += 2;
+ memcpy(d_out + 12, fr->d_bits + d_idx, 2); d_idx += 2; /* D13..D14 */
+ d_idx += 2;
+ memcpy(d_out + 14, fr->d_bits + d_idx, 14); d_idx += 14;/* D15..D28 */
+ d_idx += 2;
+ memcpy(d_out + 28, fr->d_bits + d_idx, 2); d_idx += 2; /* D29..D30 */
+ d_idx += 2;
+ memcpy(d_out + 30, fr->d_bits + d_idx, 2); d_idx += 2; /* D31..D32 */
+ d_idx += 2;
+ memcpy(d_out + 32, fr->d_bits + d_idx, 4); d_idx += 4; /* D33..D36 */
+
+ OSMO_ASSERT(d_idx == 48);
+
+ return 36;
+}
+
+
+/*! Adapt from 48 synchronous N x 4800bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 48.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx4800_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ if (in_len != 48)
+ return -EINVAL;
+
+ /* Table 6e / V.110 */
+ fr->e_bits[0] = 0;
+ fr->e_bits[1] = 1;
+ fr->e_bits[2] = 1;
+
+ memcpy(fr->d_bits, d_in, 48);
+
+ return 0;
+}
+
+static int v110_adapt_IR_to_Nx4800(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ if (out_len < 48)
+ return -ENOSPC;
+
+ if (fr->e_bits[0] != 0 || fr->e_bits[1] != 1 || fr->e_bits[2] != 1)
+ return -EINVAL;
+
+ memcpy(d_out, fr->d_bits, 48);
+
+ return 48;
+}
+
+/*! Adapt from 30 synchronous N x 12000bit/s input bits to a decoded V.110 frame.
+ * \param[out] fr caller-allocated output frame to which E+D bits are stored
+ * \param[in] d_in input user bits
+ * \param[in] in_len number of bits in d_in. Must be 30.
+ * \returns 0 on success; negative in case of error. */
+static int v110_adapt_Nx12000_to_IR(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len)
+{
+ int d_idx = 0;
+
+ if (in_len != 30)
+ return -EINVAL;
+
+ /* Table 6f / V.110 */
+ fr->e_bits[0] = 0;
+ fr->e_bits[1] = 0;
+ fr->e_bits[2] = 1;
+
+ memcpy(fr->d_bits + d_idx, d_in + 0, 10); d_idx += 10; /* D1..D10 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 10, 2); d_idx += 2; /* D11..D12 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 12, 2); d_idx += 2; /* D13..D14 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ fr->d_bits[d_idx++] = d_in[14]; /* D15 */
+ memset(fr->d_bits + d_idx, F, 3); d_idx += 3;
+ memcpy(fr->d_bits + d_idx, d_in + 15, 10); d_idx += 10; /* D16..D25 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 25, 2); d_idx += 2; /* D26..D27 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ memcpy(fr->d_bits + d_idx, d_in + 27, 2); d_idx += 2; /* D28..D29 */
+ memset(fr->d_bits + d_idx, F, 2); d_idx += 2;
+ fr->d_bits[d_idx++] = d_in[29]; /* D30 */
+ memset(fr->d_bits + d_idx, F, 3); d_idx += 3;
+
+ OSMO_ASSERT(d_idx == 48);
+
+ return 0;
+}
+
+static int v110_adapt_IR_to_Nx12000(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr)
+{
+ int d_idx = 0;
+
+ if (out_len < 30)
+ return -ENOSPC;
+
+ if (fr->e_bits[0] != 0 || fr->e_bits[1] != 0 || fr->e_bits[2] != 1)
+ return -EINVAL;
+
+ memcpy(d_out + 0, fr->d_bits + d_idx, 10); d_idx += 10; /* D1..D10 */
+ d_idx += 2;
+ memcpy(d_out + 10, fr->d_bits + d_idx, 2); d_idx += 2; /* D11..D12 */
+ d_idx += 2;
+ memcpy(d_out + 12, fr->d_bits + d_idx, 2); d_idx += 2; /* D13..D14 */
+ d_idx += 2;
+ d_out[14] = fr->d_bits[d_idx++]; /* D15 */
+ d_idx += 3;
+ memcpy(d_out + 15, fr->d_bits + d_idx, 10); d_idx += 10;/* D16..D25 */
+ d_idx += 2;
+ memcpy(d_out + 25, fr->d_bits + d_idx, 2); d_idx += 2; /* D26..D27 */
+ d_idx += 2;
+ memcpy(d_out + 27, fr->d_bits + d_idx, 2); d_idx += 2; /* D28..D29 */
+ d_idx += 2;
+ d_out[29] = fr->d_bits[d_idx++]; /* D30 */
+ d_idx += 3;
+
+ OSMO_ASSERT(d_idx == 48);
+
+ return 30;
+}
+
+/* definition of a synchronous V.110 RA1 rate adaptation. There is one for each supported tuple
+ * of user data rate and intermediate rate (IR). */
+struct osmo_v110_sync_ra1 {
+ unsigned int data_rate;
+ unsigned int intermediate_rate;
+ unsigned int user_data_chunk_bits;
+ /*! RA1 function in user bitrate -> intermediate rate direction */
+ int (*adapt_user_to_ir)(struct osmo_v110_decoded_frame *fr, const ubit_t *d_in, size_t in_len);
+ /*! RA1 function in intermediate rate -> user bitrate direction */
+ int (*adapt_ir_to_user)(ubit_t *d_out, size_t out_len, const struct osmo_v110_decoded_frame *fr);
+};
+
+/* all of the synchronous data signalling rates; see Table 1/V.110 */
+static const struct osmo_v110_sync_ra1 osmo_v110_sync_ra1_def[_NUM_OSMO_V110_SYNC_RA1] = {
+ [OSMO_V110_SYNC_RA1_600] = {
+ .data_rate = 600,
+ .intermediate_rate = 8000,
+ .user_data_chunk_bits = 6,
+ .adapt_user_to_ir = v110_adapt_600_to_IR8000,
+ .adapt_ir_to_user = v110_adapt_IR8000_to_600,
+ },
+ [OSMO_V110_SYNC_RA1_1200] = {
+ .data_rate = 1200,
+ .intermediate_rate = 8000,
+ .user_data_chunk_bits = 12,
+ .adapt_user_to_ir = v110_adapt_1200_to_IR8000,
+ .adapt_ir_to_user = v110_adapt_IR8000_to_1200,
+ },
+ [OSMO_V110_SYNC_RA1_2400] = {
+ .data_rate = 2400,
+ .intermediate_rate = 8000,
+ .user_data_chunk_bits = 24,
+ .adapt_user_to_ir = v110_adapt_2400_to_IR8000,
+ .adapt_ir_to_user = v110_adapt_IR8000_to_2400,
+ },
+ [OSMO_V110_SYNC_RA1_4800] = {
+ .data_rate = 4800,
+ .intermediate_rate = 8000,
+ .user_data_chunk_bits = 48,
+ .adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+ },
+ [OSMO_V110_SYNC_RA1_7200] = {
+ .data_rate = 7200,
+ .intermediate_rate = 16000,
+ .user_data_chunk_bits = 36,
+ .adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+ },
+ [OSMO_V110_SYNC_RA1_9600] = {
+ .data_rate = 9600,
+ .intermediate_rate = 16000,
+ .user_data_chunk_bits = 48,
+ .adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+ },
+ [OSMO_V110_SYNC_RA1_12000] = {
+ .data_rate = 12000,
+ .intermediate_rate = 32000,
+ .user_data_chunk_bits = 30,
+ .adapt_user_to_ir = v110_adapt_Nx12000_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx12000,
+ },
+ [OSMO_V110_SYNC_RA1_14400] = {
+ .data_rate = 14400,
+ .intermediate_rate = 32000,
+ .user_data_chunk_bits = 36,
+ .adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+ },
+ [OSMO_V110_SYNC_RA1_19200] = {
+ .data_rate = 19200,
+ .intermediate_rate = 32000,
+ .user_data_chunk_bits = 48,
+ .adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+ },
+ [OSMO_V110_SYNC_RA1_24000] = {
+ .data_rate = 24000,
+ .intermediate_rate = 64000,
+ .user_data_chunk_bits = 30,
+ .adapt_user_to_ir = v110_adapt_Nx12000_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx12000,
+ },
+ [OSMO_V110_SYNC_RA1_28800] = {
+ .data_rate = 28800,
+ .intermediate_rate = 64000,
+ .user_data_chunk_bits = 36,
+ .adapt_user_to_ir = v110_adapt_Nx3600_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx3600,
+ },
+ [OSMO_V110_SYNC_RA1_38400] = {
+ .data_rate = 38400,
+ .intermediate_rate = 64000,
+ .user_data_chunk_bits = 48,
+ .adapt_user_to_ir = v110_adapt_Nx4800_to_IR,
+ .adapt_ir_to_user = v110_adapt_IR_to_Nx4800,
+ },
+};
+
+/*! obtain the size (in number of bits) of the user data bits in one V.110
+ * frame for specified RA1 rate */
+int osmo_v110_sync_ra1_get_user_data_chunk_bitlen(enum osmo_v100_sync_ra1_rate rate)
+{
+ if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+ return -EINVAL;
+
+ return osmo_v110_sync_ra1_def[rate].user_data_chunk_bits;
+}
+
+/*! obtain the user data rate (in bits/s) for specified RA1 rate */
+int osmo_v110_sync_ra1_get_user_data_rate(enum osmo_v100_sync_ra1_rate rate)
+{
+ if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+ return -EINVAL;
+
+ return osmo_v110_sync_ra1_def[rate].data_rate;
+}
+
+/*! obtain the intermediate rate (in bits/s) for specified RA1 rate */
+int osmo_v110_sync_ra1_get_intermediate_rate(enum osmo_v100_sync_ra1_rate rate)
+{
+ if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+ return -EINVAL;
+
+ return osmo_v110_sync_ra1_def[rate].intermediate_rate;
+}
+
+/*! perform V.110 RA1 function in user rate -> intermediate rate direction.
+ * \param[in] rate specification of the user bitrate
+ * \param[out] fr caller-allocated output buffer for the [decoded] V.110 frame generated
+ * \param[in] d_in input user data (unpacked bits)
+ * \param[in] in_len length of user input data (in number of bits)
+ * \returns 0 on success; negative in case of error */
+int osmo_v110_sync_ra1_user_to_ir(enum osmo_v100_sync_ra1_rate rate, struct osmo_v110_decoded_frame *fr,
+ const ubit_t *d_in, size_t in_len)
+{
+ if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+ return -EINVAL;
+
+ return osmo_v110_sync_ra1_def[rate].adapt_user_to_ir(fr, d_in, in_len);
+}
+
+/*! perform V.110 RA1 function in intermediate rate -> user rate direction.
+ * \param[in] rate specification of the user bitrate
+ * \param[out] d_out caller-allocated output user data (unpacked bits)
+ * \param[out] out_len length of d_out output buffer
+ * \param[in] fr [decoded] V.110 frame used as input
+ * \returns number of unpacked bits written to d_out on success; negative in case of error */
+int osmo_v110_sync_ra1_ir_to_user(enum osmo_v100_sync_ra1_rate rate, ubit_t *d_out, size_t out_len,
+ const struct osmo_v110_decoded_frame *fr)
+{
+ if (rate < 0 || rate >= _NUM_OSMO_V110_SYNC_RA1)
+ return -EINVAL;
+
+ return osmo_v110_sync_ra1_def[rate].adapt_ir_to_user(d_out, out_len, fr);
+}