Decoding and encoding of FR and EFR TRAU frames are put into seperate functions. CRC check is done to detect bad EFR TRAU frames. The test case includes FR and EFR transcoding. EFR support was tested with Nokia InSite BTS and Siemens BS11. --- openbsc/configure.ac | 1 + openbsc/include/openbsc/mncc.h | 1 + openbsc/include/openbsc/trau_mux.h | 10 ++ openbsc/src/libmsc/gsm_04_08.c | 1 + openbsc/src/libtrau/trau_mux.c | 307 +++++++++++++++++++++++++++++------- openbsc/tests/Makefile.am | 2 +- openbsc/tests/testsuite.at | 6 + openbsc/tests/trau/Makefile.am | 17 ++ openbsc/tests/trau/trau_test.c | 82 ++++++++++ 9 files changed, 368 insertions(+), 59 deletions(-) create mode 100644 openbsc/tests/trau/Makefile.am create mode 100644 openbsc/tests/trau/trau_test.c diff --git a/openbsc/configure.ac b/openbsc/configure.ac index 081e416..fe99569 100644 --- a/openbsc/configure.ac +++ b/openbsc/configure.ac @@ -169,6 +169,7 @@ AC_OUTPUT( tests/si/Makefile tests/abis/Makefile tests/smpp/Makefile + tests/trau/Makefile doc/Makefile doc/examples/Makefile Makefile) diff --git a/openbsc/include/openbsc/mncc.h b/openbsc/include/openbsc/mncc.h index 4a99bb1..ffc247b 100644 --- a/openbsc/include/openbsc/mncc.h +++ b/openbsc/include/openbsc/mncc.h @@ -95,6 +95,7 @@ struct gsm_call { #define GSM_TCHF_FRAME 0x0300 #define GSM_TCHF_FRAME_EFR 0x0301 +#define GSM_TCHF_BAD_FRAME 0x03ff #define MNCC_SOCKET_HELLO 0x0400 diff --git a/openbsc/include/openbsc/trau_mux.h b/openbsc/include/openbsc/trau_mux.h index 667f623..d211d8d 100644 --- a/openbsc/include/openbsc/trau_mux.h +++ b/openbsc/include/openbsc/trau_mux.h @@ -56,3 +56,13 @@ int switch_trau_mux(struct gsm_lchan *old_lchan, struct gsm_lchan *new_lchan); /* callback invoked if we receive TRAU frames */ int subch_cb(struct subch_demux *dmx, int ch, uint8_t *data, int len, void *_priv); + +/* TRAU frame transcoding */ +struct msgb *trau_decode_fr(uint32_t callref, + const struct decoded_trau_frame *tf); +struct msgb *trau_decode_efr(uint32_t callref, + const struct decoded_trau_frame *tf); +void trau_encode_fr(struct decoded_trau_frame *tf, + const unsigned char *data); +void trau_encode_efr(struct decoded_trau_frame *tf, + const unsigned char *data); diff --git a/openbsc/src/libmsc/gsm_04_08.c b/openbsc/src/libmsc/gsm_04_08.c index 7a92e4d..2df27a0 100644 --- a/openbsc/src/libmsc/gsm_04_08.c +++ b/openbsc/src/libmsc/gsm_04_08.c @@ -2910,6 +2910,7 @@ int mncc_tx_to_cc(struct gsm_network *net, int msg_type, void *arg) case MNCC_FRAME_RECV: return tch_recv_mncc(net, data->callref, 1); case GSM_TCHF_FRAME: + case GSM_TCHF_FRAME_EFR: /* Find callref */ trans = trans_find_by_callref(net, data->callref); if (!trans) { diff --git a/openbsc/src/libtrau/trau_mux.c b/openbsc/src/libtrau/trau_mux.c index d25e78f..c73884b 100644 --- a/openbsc/src/libtrau/trau_mux.c +++ b/openbsc/src/libtrau/trau_mux.c @@ -31,6 +31,7 @@ #include <osmocom/core/talloc.h> #include <openbsc/trau_upqueue.h> #include <openbsc/transaction.h> +#include <osmocom/core/crcgen.h> /* this corresponds to the bit-lengths of the individual codec * parameters as indicated in Table 1.1 of TS 06.10 */ @@ -47,6 +48,53 @@ static const uint8_t gsm_fr_map[] = { 3, 3, 3, 3 }; + +/* + * EFR TRAU parity + * + * g(x) = x^3 + x^1 + 1 + */ +const struct osmo_crc8gen_code gsm0860_efr_crc3 = { + .bits = 3, + .poly = 0x3, + .init = 0x0, + .remainder = 0x7, +}; + +/* EFR parity bits */ +static inline void efr_parity_bits_1(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 0, 22); + memcpy(check_bits + 22 , d_bits + 24, 3); + check_bits[25] = d_bits[28]; +} + +static inline void efr_parity_bits_2(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 42, 10); + memcpy(check_bits + 10 , d_bits + 90, 2); +} + +static inline void efr_parity_bits_3(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 98, 5); + check_bits[5] = d_bits[104]; + memcpy(check_bits + 6 , d_bits + 143, 2); +} + +static inline void efr_parity_bits_4(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 151, 10); + memcpy(check_bits + 10 , d_bits + 199, 2); +} + +static inline void efr_parity_bits_5(ubit_t *check_bits, const ubit_t *d_bits) +{ + memcpy(check_bits + 0 , d_bits + 207, 5); + check_bits[5] = d_bits[213]; + memcpy(check_bits + 6 , d_bits + 252, 2); +} + struct map_entry { struct llist_head list; struct gsm_e1_subslot src, dst; @@ -159,7 +207,117 @@ lookup_trau_upqueue(const struct gsm_e1_subslot *src) return NULL; } -static const uint8_t c_bits_check[] = { 0, 0, 0, 1, 0 }; +static const uint8_t c_bits_check_fr[] = { 0, 0, 0, 1, 0 }; +static const uint8_t c_bits_check_efr[] = { 1, 1, 0, 1, 0 }; + +struct msgb *trau_decode_fr(uint32_t callref, + const struct decoded_trau_frame *tf) +{ + struct msgb *msg; + struct gsm_data_frame *frame; + unsigned char *data; + int i, j, k, l, o; + + msg = msgb_alloc(sizeof(struct gsm_data_frame) + 33, + "GSM-DATA"); + if (!msg) + return NULL; + + frame = (struct gsm_data_frame *)msg->data; + memset(frame, 0, sizeof(struct gsm_data_frame)); + data = frame->data; + data[0] = 0xd << 4; + /* reassemble d-bits */ + i = 0; /* counts bits */ + j = 4; /* counts output bits */ + k = gsm_fr_map[0]-1; /* current number bit in element */ + l = 0; /* counts element bits */ + o = 0; /* offset input bits */ + while (i < 260) { + data[j/8] |= (tf->d_bits[k+o] << (7-(j%8))); + if (--k < 0) { + o += gsm_fr_map[l]; + k = gsm_fr_map[++l]-1; + } + i++; + j++; + } + frame->msg_type = GSM_TCHF_FRAME; + frame->callref = callref; + msgb_put(msg, sizeof(struct gsm_data_frame) + 33); + + return msg; +} + +struct msgb *trau_decode_efr(uint32_t callref, + const struct decoded_trau_frame *tf) +{ + struct msgb *msg; + struct gsm_data_frame *frame; + unsigned char *data; + int i, j, rc; + ubit_t check_bits[26]; + + msg = msgb_alloc(sizeof(struct gsm_data_frame) + 31, + "GSM-DATA"); + if (!msg) + return NULL; + + frame = (struct gsm_data_frame *)msg->data; + memset(frame, 0, sizeof(struct gsm_data_frame)); + frame->msg_type = GSM_TCHF_FRAME_EFR; + frame->callref = callref; + msgb_put(msg, sizeof(struct gsm_data_frame) + 31); + + if (tf->c_bits[11]) /* BFI */ + goto bad_frame; + + data = frame->data; + data[0] = 0xc << 4; + /* reassemble d-bits */ + for (i = 1, j = 4; i < 39; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_1(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 26, + tf->d_bits + 39); + if (rc) + goto bad_frame; + for (i = 42, j = 42; i < 95; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_2(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 95); + if (rc) + goto bad_frame; + for (i = 98, j = 95; i < 148; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_3(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 148); + if (rc) + goto bad_frame; + for (i = 151, j = 145; i < 204; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_4(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 204); + if (rc) + goto bad_frame; + for (i = 207, j = 198; i < 257; i++, j++) + data[j/8] |= (tf->d_bits[i] << (7-(j%8))); + efr_parity_bits_5(check_bits, tf->d_bits); + rc = osmo_crc8gen_check_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 257); + if (rc) + goto bad_frame; + + return msg; + +bad_frame: + frame->msg_type = GSM_TCHF_BAD_FRAME; + + return msg; +} /* we get called by subchan_demux */ int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, @@ -178,45 +336,25 @@ int trau_mux_input(struct gsm_e1_subslot *src_e1_ss, return rc; if (!dst_e1_ss) { - struct msgb *msg; - struct gsm_data_frame *frame; - unsigned char *data; - int i, j, k, l, o; + struct msgb *msg = NULL; /* frame shall be sent to upqueue */ if (!(ue = lookup_trau_upqueue(src_e1_ss))) return -EINVAL; if (!ue->callref) return -EINVAL; - if (memcmp(tf.c_bits, c_bits_check, sizeof(c_bits_check))) + if (!memcmp(tf.c_bits, c_bits_check_fr, 5)) + msg = trau_decode_fr(ue->callref, &tf); + else if (!memcmp(tf.c_bits, c_bits_check_efr, 5)) + msg = trau_decode_efr(ue->callref, &tf); + else { DEBUGPC(DLMUX, "illegal trau (C1-C5) %s\n", - osmo_hexdump(tf.c_bits, sizeof(c_bits_check))); - msg = msgb_alloc(sizeof(struct gsm_data_frame) + 33, - "GSM-DATA"); + osmo_hexdump(tf.c_bits, 5)); + DEBUGPC(DLMUX, "test trau (C1-C5) %s\n", + osmo_hexdump(c_bits_check_efr, 5)); + return -EINVAL; + } if (!msg) return -ENOMEM; - - frame = (struct gsm_data_frame *)msg->data; - memset(frame, 0, sizeof(struct gsm_data_frame)); - data = frame->data; - data[0] = 0xd << 4; - /* reassemble d-bits */ - i = 0; /* counts bits */ - j = 4; /* counts output bits */ - k = gsm_fr_map[0]-1; /* current number bit in element */ - l = 0; /* counts element bits */ - o = 0; /* offset input bits */ - while (i < 260) { - data[j/8] |= (tf.d_bits[k+o] << (7-(j%8))); - if (--k < 0) { - o += gsm_fr_map[l]; - k = gsm_fr_map[++l]-1; - } - i++; - j++; - } - frame->msg_type = GSM_TCHF_FRAME; - frame->callref = ue->callref; - msgb_put(msg, sizeof(struct gsm_data_frame) + 33); trau_tx_to_mncc(ue->net, msg); return 0; @@ -276,13 +414,86 @@ int trau_recv_lchan(struct gsm_lchan *lchan, uint32_t callref) return 0; } +void trau_encode_fr(struct decoded_trau_frame *tf, + const unsigned char *data) +{ + int i, j, k, l, o; + + /* set c-bits and t-bits */ + tf->c_bits[0] = 1; + tf->c_bits[1] = 1; + tf->c_bits[2] = 1; + tf->c_bits[3] = 0; + tf->c_bits[4] = 0; + memset(&tf->c_bits[5], 0, 6); + memset(&tf->c_bits[11], 1, 10); + memset(&tf->t_bits[0], 1, 4); + /* reassemble d-bits */ + i = 0; /* counts bits */ + j = 4; /* counts input bits */ + k = gsm_fr_map[0]-1; /* current number bit in element */ + l = 0; /* counts element bits */ + o = 0; /* offset output bits */ + while (i < 260) { + tf->d_bits[k+o] = (data[j/8] >> (7-(j%8))) & 1; + if (--k < 0) { + o += gsm_fr_map[l]; + k = gsm_fr_map[++l]-1; + } + i++; + j++; + } +} + +void trau_encode_efr(struct decoded_trau_frame *tf, + const unsigned char *data) +{ + int i, j; + ubit_t check_bits[26]; + + /* set c-bits and t-bits */ + tf->c_bits[0] = 1; + tf->c_bits[1] = 1; + tf->c_bits[2] = 0; + tf->c_bits[3] = 1; + tf->c_bits[4] = 0; + memset(&tf->c_bits[5], 0, 6); + memset(&tf->c_bits[11], 1, 10); + memset(&tf->t_bits[0], 1, 4); + /* reassemble d-bits */ + tf->d_bits[0] = 1; + for (i = 1, j = 4; i < 39; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_1(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 26, + tf->d_bits + 39); + for (i = 42, j = 42; i < 95; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_2(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 95); + for (i = 98, j = 95; i < 148; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_3(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 148); + for (i = 151, j = 145; i < 204; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_4(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 12, + tf->d_bits + 204); + for (i = 207, j = 198; i < 257; i++, j++) + tf->d_bits[i] = (data[j/8] >> (7-(j%8))) & 1; + efr_parity_bits_5(check_bits, tf->d_bits); + osmo_crc8gen_set_bits(&gsm0860_efr_crc3, check_bits, 8, + tf->d_bits + 257); +} + int trau_send_frame(struct gsm_lchan *lchan, struct gsm_data_frame *frame) { uint8_t trau_bits_out[TRAU_FRAME_BITS]; struct gsm_e1_subslot *dst_e1_ss = &lchan->ts->e1_link; struct subch_mux *mx; - int i, j, k, l, o; - unsigned char *data = frame->data; struct decoded_trau_frame tf; mx = e1inp_get_mux(dst_e1_ss->e1_nr, dst_e1_ss->e1_ts); @@ -291,30 +502,10 @@ int trau_send_frame(struct gsm_lchan *lchan, struct gsm_data_frame *frame) switch (frame->msg_type) { case GSM_TCHF_FRAME: - /* set c-bits and t-bits */ - tf.c_bits[0] = 1; - tf.c_bits[1] = 1; - tf.c_bits[2] = 1; - tf.c_bits[3] = 0; - tf.c_bits[4] = 0; - memset(&tf.c_bits[5], 0, 6); - memset(&tf.c_bits[11], 1, 10); - memset(&tf.t_bits[0], 1, 4); - /* reassemble d-bits */ - i = 0; /* counts bits */ - j = 4; /* counts input bits */ - k = gsm_fr_map[0]-1; /* current number bit in element */ - l = 0; /* counts element bits */ - o = 0; /* offset output bits */ - while (i < 260) { - tf.d_bits[k+o] = (data[j/8] >> (7-(j%8))) & 1; - if (--k < 0) { - o += gsm_fr_map[l]; - k = gsm_fr_map[++l]-1; - } - i++; - j++; - } + trau_encode_fr(&tf, frame->data); + break; + case GSM_TCHF_FRAME_EFR: + trau_encode_efr(&tf, frame->data); break; default: DEBUGPC(DLMUX, "unsupported message type %d\n", diff --git a/openbsc/tests/Makefile.am b/openbsc/tests/Makefile.am index 7f51bfa..d4bb954 100644 --- a/openbsc/tests/Makefile.am +++ b/openbsc/tests/Makefile.am @@ -1,4 +1,4 @@ -SUBDIRS = gsm0408 db channel mgcp gprs si abis gbproxy +SUBDIRS = gsm0408 db channel mgcp gprs si abis gbproxy trau if BUILD_NAT SUBDIRS += bsc-nat bsc-nat-trie diff --git a/openbsc/tests/testsuite.at b/openbsc/tests/testsuite.at index 76110f5..652cfe9 100644 --- a/openbsc/tests/testsuite.at +++ b/openbsc/tests/testsuite.at @@ -81,3 +81,9 @@ AT_KEYWORDS([gbproxy]) cat $abs_srcdir/gbproxy/gbproxy_test.ok > expout AT_CHECK([$abs_top_builddir/tests/gbproxy/gbproxy_test], [], [expout], [ignore]) AT_CLEANUP + +AT_SETUP([trau]) +AT_KEYWORDS([trau]) +cat $abs_srcdir/trau/trau_test.ok > expout +AT_CHECK([$abs_top_builddir/tests/trau/trau_test], [], [expout], [ignore]) +AT_CLEANUP diff --git a/openbsc/tests/trau/Makefile.am b/openbsc/tests/trau/Makefile.am new file mode 100644 index 0000000..d4aa1c3 --- /dev/null +++ b/openbsc/tests/trau/Makefile.am @@ -0,0 +1,17 @@ +AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include +AM_CFLAGS=-Wall -ggdb3 $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) $(LIBOSMOABIS_CFLAGS) $(LIBSMPP34_CFLAGS) $(COVERAGE_CFLAGS) +AM_LDFLAGS = $(COVERAGE_LDFLAGS) + +EXTRA_DIST = trau_test.ok + +noinst_PROGRAMS = trau_test + +trau_test_SOURCES = trau_test.c +trau_test_LDADD = $(top_builddir)/src/libbsc/libbsc.a \ + $(top_builddir)/src/libmsc/libmsc.a \ + $(top_builddir)/src/libbsc/libbsc.a \ + $(top_builddir)/src/libtrau/libtrau.a \ + $(top_builddir)/src/libcommon/libcommon.a \ + $(LIBOSMOCORE_LIBS) $(LIBOSMOABIS_LIBS) \ + $(LIBOSMOGSM_LIBS) $(LIBSMPP34_LIBS) $(LIBOSMOVTY_LIBS) -ldl -ldbi + diff --git a/openbsc/tests/trau/trau_test.c b/openbsc/tests/trau/trau_test.c new file mode 100644 index 0000000..f8a48db --- /dev/null +++ b/openbsc/tests/trau/trau_test.c @@ -0,0 +1,82 @@ +/* (C) 2013 by Andreas Eversberg &lt;jolly(a)eversberg.eu&gt; + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU Affero General Public License as published by + * the Free Software Foundation; either version 3 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. + * + * You should have received a copy of the GNU Affero General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + * + */ + +#include <osmocom/abis/trau_frame.h> +#include <openbsc/trau_mux.h> +#include <osmocom/core/msgb.h> + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> + +void test_trau_fr_efr(unsigned char *data) +{ + struct decoded_trau_frame tf; + struct msgb *msg; + struct gsm_data_frame *frame; + + printf("Testing TRAU FR transcoding.\n"); + data[0] = 0xd0; + trau_encode_fr(&tf, data); + tf.c_bits[11] = 0; /* clear BFI */ + msg = trau_decode_fr(1, &tf); + OSMO_ASSERT(msg != NULL); + frame = (struct gsm_data_frame *)msg->data; + OSMO_ASSERT(frame->msg_type == GSM_TCHF_FRAME); + OSMO_ASSERT(!memcmp(frame->data, data, 33)); + msgb_free(msg); + + printf("Testing TRAU EFR transcoding.\n"); + data[0] = 0xc0; + trau_encode_efr(&tf, data); + OSMO_ASSERT(tf.d_bits[0] == 1); /* spare bit must be 1 */ + tf.c_bits[11] = 0; /* clear BFI */ + msg = trau_decode_efr(1, &tf); + OSMO_ASSERT(msg != NULL); + frame = (struct gsm_data_frame *)msg->data; + OSMO_ASSERT(frame->msg_type == GSM_TCHF_FRAME_EFR); + OSMO_ASSERT(!memcmp(frame->data, data, 31)); + + printf("Testing TRAU EFR decoding with CRC error.\n"); + tf.d_bits[0] = 0; /* spare bit must be included */ + msg = trau_decode_efr(1, &tf); + OSMO_ASSERT(msg != NULL); + frame = (struct gsm_data_frame *)msg->data; + OSMO_ASSERT(frame->msg_type == GSM_TCHF_BAD_FRAME); + msgb_free(msg); +} + +int main() +{ + unsigned char data[33]; + int i; + + memset(data, 0x00, sizeof(data)); + test_trau_fr_efr(data); + memset(data, 0xff, sizeof(data)); + test_trau_fr_efr(data); + srandom(42); + for (i = 0; i < sizeof(data); i++) + data[i] = random(); + test_trau_fr_efr(data); + printf("Done\n"); + return 0; +} + +/* stubs */ +void vty_out() {} -- 1.7.3.4