OpenBSC October 2009

openbsc@lists.osmocom.org

25 participants
64 discussions

official ip.access wireshark Abis/IP dissector

by Harald Welte

Hi! Quite some time ago (must be 2-3 months ago), I have officially inquired at ip.access about the source code of their wireshark modifications, as per the GNU GPL. It took them some time, but they eventually responded recently. Today I finally received a CD-ROM with the source code. I've uploaded it to the OpenBSC wiki, and it is now available from http://openbsc.gnumonks.org/trac/attachment/wiki/nanoBTS/wireshark-1.0.6ipa… Had I known earlier that ip.access has actually written a GPL licensed dissector, many hours (rather days/weeks) of reverse engineering time would have been saved. I have not yet had time to review it thoroughly, though I plan to merge/port the interesting bits of it with my dissectors for A-bis OML and ip.access RSL extensions and eventually submit it to wireshark mainline. If you use this source code, please don't just simply take it and push it to upstream wireshark, as that would conflict with the patches that we have in openbsc git at the moment. Have fun with it, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

15 years, 10 months

nanoBTS Multi-TRX configuration?

by Harald Welte

Hi! Does anyone on this list have experience with nanoBTS Multi-TRX configurations? I've built a TIB cable (10pin RJ69 to 10pin, 1:1 wiring, i.e. pin1 is pin1 on the other plug, pin2 is pin 2, etc.) and connected the two BTS. When I power them up simultaneously, they still come up as two individual BTS with each their own unit ID. I've tried to set the unit ID to something like 1801/0/0 on the first one, and 1801/1/0 on the second. However, any non-zero TRX ID of the unit ID is rejected by the BTS. Any hint how I can make them behave like one BTS with two TRX is appreciated. I'm expecting only one OML Link but of course two RSL links (one for each TRX). Thanks in advance, Harald -- - Harald Welte <laforge(a)gnumonks.org> http://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)

15 years, 10 months

(no subject)

by Andreas.Eversberg

hi, i am no shure if i already sent this mail, but i can't find it anywhere. this fixes the delay of audio caused by stalling of the openbsc process. the use of 'usleep(100000)' for slowing down transmission to nanoBTS is replaced by the tx-delay timer. i did this on bs11 code, so i did it the same way. it actually queues frames for transmission not nanoBTS. on transmission a timer is started and when this timer expires, the next frame in the queue is transmitted (timer restarted) until the queue is empty. regards andreas

15 years, 10 months

Running an licensed experimental GSM network at 26c3

by Bjoern Heller

Hello everyone, I just want to ask, if there is a general interest in operating a licensed GSM-Network at the chaos congress. Is there anything planned for 26c3 (openBSC desk etc.)? Maybe there is a good chance to get a temp. license for the 900 GSM band from BNetzA. I had little time in the past year to work on openBSC, but in the coming months there will be more time for fun ;) Best regards Bjoern - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Björn Heller Jabber: tec(a)jabber.hellercom.de

15 years, 10 months

nanoBTS 140 is working now

by Philipp Hug

Hi everyone, Thanks to some hints from Sylvain my nanoBTS 140 is working now. We found the following problems: * Software Activation request is not complete ( it needs to contain tag + FILE_ID and FILE_VERSION). See patch sent by Sylvain. * It's relevant which Software is activated, but our logic to always use the first SW Description record works most of the time because the nanoBTS will move the software that was activated the last time to the first position. So maybe we need hard-code which software to prefer for activation or we put some warnings in the wiki. What's left is that after some time the BTRS reports an error and goes to Disabled state, but I have to investigate that more. Philipp

15 years, 10 months

[PATCH] Support for mobile-originated USSD - working demonstration (*#100# to get own number) Signed-off-by: Mike Haben <michael.haben@btinternet.com>

by Mike Haben

--- openbsc/include/openbsc/gsm_04_80.h | 19 +++- openbsc/src/gsm_04_80.c | 252 +++++++++++++++++++++-------------- openbsc/src/ussd.c | 15 ++- 3 files changed, 180 insertions(+), 106 deletions(-) mode change 100644 => 100755 openbsc/include/openbsc/ussd.h mode change 100644 => 100755 openbsc/src/gsm_04_08.c mode change 100644 => 100755 openbsc/src/ussd.c diff --git a/openbsc/include/openbsc/gsm_04_80.h b/openbsc/include/openbsc/gsm_04_80.h index d16a876..43b5b74 100755 --- a/openbsc/include/openbsc/gsm_04_80.h +++ b/openbsc/include/openbsc/gsm_04_80.h @@ -3,8 +3,25 @@ #include <openbsc/msgb.h> +/* GSM TS 04.80 definitions (Supplementary Services specification, Formats and coding */ +/* Section 3.6.5 */ +#define GSM_0480_SEQUENCE_TAG 0x30 +#define GSM_0480_SET_TAG 0x31 + +/* ASN.1 type-tags */ +#define ASN1_BOOLEAN_TAG 0x01 +#define ASN1_INTEGER_TAG 0x02 +#define ASN1_BIT_STRING_TAG 0x03 +#define ASN1_OCTET_STRING_TAG 0x04 +#define ASN1_NULL_TYPE_TAG 0x05 +#define ASN1_OBJECT_ID_TAG 0x06 +#define ASN1_UTF8_STRING_TAG 0x0C +#define ASN1_PRINTABLE_STRING_TAG 0x13 +#define ASN1_IA5_STRING_TAG 0x16 +#define ASN1_UNICODE_STRING_TAG 0x1E + char* gsm0480_rcv_ussd(struct msgb *msg); int gsm0480_send_ussd_response(struct msgb *msg, const char* response_text); -int gsm0480_send_ussd_error(struct msgb *msg); +int gsm0480_send_ussd_reject(struct msgb *msg); #endif diff --git a/openbsc/include/openbsc/ussd.h b/openbsc/include/openbsc/ussd.h old mode 100644 new mode 100755 diff --git a/openbsc/src/gsm_04_08.c b/openbsc/src/gsm_04_08.c old mode 100644 new mode 100755 diff --git a/openbsc/src/gsm_04_80.c b/openbsc/src/gsm_04_80.c index c2c2a86..a6dffa8 100755 --- a/openbsc/src/gsm_04_80.c +++ b/openbsc/src/gsm_04_80.c @@ -39,26 +39,63 @@ /* GSM TS 04.80 definitions (Supplementary Services specification, Formats and coding */ /* Section 3.4 */ -#define GSM0480_MTYPE_RELEASE_COMPLETE 0x2A -#define GSM0480_MTYPE_FACILITY 0x3A -#define GSM0480_MTYPE_REGISTER 0x3B +#define GSM0480_MTYPE_RELEASE_COMPLETE 0x2A +#define GSM0480_MTYPE_FACILITY 0x3A +#define GSM0480_MTYPE_REGISTER 0x3B /* Section 3.5 */ -#define GSM0480_IE_FACILITY 0x1C -#define GSM0480_IE_SS_VERSION 0x7F +#define GSM0480_IE_FACILITY 0x1C +#define GSM0480_IE_SS_VERSION 0x7F /* Section 3.6.2 */ -#define GSM0480_CTYPE_INVOKE 0xA1 -#define GSM0480_CTYPE_RETURN_RESULT 0xA2 -#define GSM0480_CTYPE_RETURN_ERROR 0xA3 -#define GSM0480_CTYPE_REJECT 0xA4 +#define GSM0480_CTYPE_INVOKE 0xA1 +#define GSM0480_CTYPE_RETURN_RESULT 0xA2 +#define GSM0480_CTYPE_RETURN_ERROR 0xA3 +#define GSM0480_CTYPE_REJECT 0xA4 /* Section 3.6.3 */ -#define GSM0480_COMPIDTAG_INVOKE_ID 0x02 -#define GSM0480_COMPIDTAG_LINKED_ID 0x80 +#define GSM0480_COMPIDTAG_INVOKE_ID 0x02 +#define GSM0480_COMPIDTAG_LINKED_ID 0x80 /* Section 3.6.4 */ -#define GSM0480_OPERATION_CODE 0x02 +#define GSM0480_OPERATION_CODE 0x02 + +/* Section 3.6.6 */ +#define GSM_0480_ERROR_CODE_TAG 0x02 + +/* Section 3.6.7 */ +/* Table 3.13 */ +#define GSM_0480_PROBLEM_CODE_TAG_GENERAL 0x80 +#define GSM_0480_PROBLEM_CODE_TAG_INVOKE 0x81 +#define GSM_0480_PROBLEM_CODE_TAG_RETURN_RESULT 0x82 +#define GSM_0480_PROBLEM_CODE_TAG_RETURN_ERROR 0x83 + +/* Table 3.14 */ +#define GSM_0480_GEN_PROB_CODE_UNRECOGNISED 0x00 +#define GSM_0480_GEN_PROB_CODE_MISTYPED 0x01 +#define GSM_0480_GEN_PROB_CODE_BAD_STRUCTURE 0x02 + +/* Table 3.15 */ +#define GSM_0480_INVOKE_PROB_CODE_DUPLICATE_INVOKE_ID 0x00 +#define GSM_0480_INVOKE_PROB_CODE_UNRECOGNISED_OPERATION 0x01 +#define GSM_0480_INVOKE_PROB_CODE_MISTYPED_PARAMETER 0x02 +#define GSM_0480_INVOKE_PROB_CODE_RESOURCE_LIMITATION 0x03 +#define GSM_0480_INVOKE_PROB_CODE_INITIATING_RELEASE 0x04 +#define GSM_0480_INVOKE_PROB_CODE_UNRECOGNISED_LINKED_ID 0x05 +#define GSM_0480_INVOKE_PROB_CODE_UNEXPECTED_LINKED_RESPONSE 0x06 +#define GSM_0480_INVOKE_PROB_CODE_UNEXPECTED_LINKED_OPERATION 0x07 + +/* Table 3.16 */ +#define GSM_0480_RESULT_PROB_CODE_UNRECOGNISED_INVOKE_ID 0x00 +#define GSM_0480_RESULT_PROB_CODE_RETURN_RESULT_UNEXPECTED 0x01 +#define GSM_0480_RESULT_PROB_CODE_MISTYPED_PARAMETER 0x02 + +/* Table 3.17 */ +#define GSM_0480_ERROR_PROB_CODE_UNRECOGNISED_INVOKE_ID 0x00 +#define GSM_0480_ERROR_PROB_CODE_RETURN_ERROR_UNEXPECTED 0x01 +#define GSM_0480_ERROR_PROB_CODE_UNRECOGNISED_ERROR 0x02 +#define GSM_0480_ERROR_PROB_CODE_UNEXPECTED_ERROR 0x03 +#define GSM_0480_ERROR_PROB_CODE_MISTYPED_PARAMETER 0x04 /* Section 4.5 */ #define GSM0480_OP_CODE_REGISTER_SS 0x0A @@ -105,11 +142,13 @@ #define GSM0480_ERR_CODE_MAX_MPTY_PARTICIPANTS 0x7E #define GSM0480_ERR_CODE_RESOURCES_NOT_AVAILABLE 0x7F -static char ussd_string_buff[256]; +static char ussd_string_buff[32]; +static u_int8_t last_transaction_id; +static u_int8_t last_invoke_id; /* Forward declarations */ -static int parse_ussd(u_int8_t *ussd, u_int8_t length); -static int parse_ussd_information_elements(u_int8_t *ussd_ie, u_int8_t length); +static int parse_ussd(u_int8_t *ussd); +static int parse_ussd_information_elements(u_int8_t *ussd_ie); static int parse_facility_ie(u_int8_t *facility_ie, u_int8_t length); static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length); static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length); @@ -117,34 +156,26 @@ static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length); /* Receive a mobile-originated USSD message and return the decoded text */ char* gsm0480_rcv_ussd(struct msgb *msg) { - int rc = 1; - u_int8_t tag; - u_int8_t length; - u_int8_t offset = 2; // don't yet understand the first 2 bytes, so ignore them for now + int rc = 0; + u_int8_t* parse_ptr = msgb_l3(msg); - DEBUGP(DMM, "USSD %s\n", hexdump(msg->data, msg->len)); // preliminary! Just see what we're receiving... +// DEBUGP(DMM, "USSD %s\n", hexdump(msg->data, msg->len)); // temporary, just see what we're receiving... memset(ussd_string_buff, 0, sizeof(ussd_string_buff)); - do + if((*parse_ptr & 0x0F) == GSM48_PDISC_NC_SS) { - tag = msg->data[offset]; - length = msg->data[offset+1]; - if((msg->data[offset+2] & 0x0f) == GSM48_PDISC_NC_SS) // not sure if this is correct??? - rc &= parse_ussd(&(msg->data[offset+3]), length-3); - offset += (length+2); + last_transaction_id = *parse_ptr & 0xF0; + rc = parse_ussd(parse_ptr + 1); } - while(offset < msg->len); - if(rc) - DEBUGP(DMM, "USSD received OK, response not yet implemented\n"); - else + if(!rc) DEBUGP(DMM, "Error occurred while parsing received USSD!\n"); return ussd_string_buff; } -static int parse_ussd(u_int8_t *ussd, u_int8_t length) +static int parse_ussd(u_int8_t *ussd) { int rc = 1; u_int8_t msg_type = ussd[0] & 0xBF; // message-type - section 3.4 @@ -152,10 +183,11 @@ static int parse_ussd(u_int8_t *ussd, u_int8_t length) switch(msg_type) { case GSM0480_MTYPE_RELEASE_COMPLETE: DEBUGP(DMM, "USS Release Complete\n"); // could also parse out the optional Cause/Facility data + ussd_string_buff[0] = 0xFF; break; case GSM0480_MTYPE_REGISTER: case GSM0480_MTYPE_FACILITY: - rc &= parse_ussd_information_elements(ussd+1, length-1); + rc &= parse_ussd_information_elements(ussd+1); break; default: fprintf(stderr, "Unknown GSM 04.80 message-type field 0x%02x\n", @@ -167,34 +199,26 @@ static int parse_ussd(u_int8_t *ussd, u_int8_t length) return rc; } -static int parse_ussd_information_elements(u_int8_t *ussd_ie, u_int8_t length) +static int parse_ussd_information_elements(u_int8_t *ussd_ie) { - int rc = 1; - u_int8_t offset = 0; + int rc; - do - { - u_int8_t iei = ussd_ie[offset]; // Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 - u_int8_t iei_length = ussd_ie[offset+1]; - switch(iei) { - case GSM48_IE_CAUSE: - break; - case GSM0480_IE_FACILITY: - rc &= parse_facility_ie(ussd_ie+2, iei_length); - break; - case GSM0480_IE_SS_VERSION: - break; - default: - fprintf(stderr, "Unhandled GSM 04.08 or 04.80 Information Element Identifier 0x%02x\n", - iei); - rc = 0; - break; - } - - - offset += (iei_length+2); + u_int8_t iei = ussd_ie[0]; // Information Element Identifier - table 3.2 & GSM 04.08 section 10.5 + u_int8_t iei_length = ussd_ie[1]; + switch(iei) { + case GSM48_IE_CAUSE: + break; + case GSM0480_IE_FACILITY: + rc = parse_facility_ie(ussd_ie+2, iei_length); + break; + case GSM0480_IE_SS_VERSION: + break; + default: + fprintf(stderr, "Unhandled GSM 04.08 or 04.80 Information Element Identifier 0x%02x\n", + iei); + rc = 0; + break; } - while(offset < length); return rc; } @@ -243,6 +267,7 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length) invoke_data[0]); } u_int8_t offset = invoke_data[1] + 2; + last_invoke_id = invoke_data[2]; if(invoke_data[offset] == GSM0480_COMPIDTAG_LINKED_ID) // optional part offset += invoke_data[offset+1] + 2; // skip over it @@ -252,7 +277,7 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length) u_int8_t operation_code = invoke_data[offset+2]; switch(operation_code) { case GSM0480_OP_CODE_PROCESS_USS_REQ: - rc = parse_process_uss_req(invoke_data + 3, length - 3); + rc = parse_process_uss_req(invoke_data + offset + 3, length - offset - 3); break; default: fprintf(stderr, "GSM 04.80 operation code 0x%02x is not yet handled\n", @@ -275,75 +300,100 @@ static int parse_ss_invoke(u_int8_t *invoke_data, u_int8_t length) static int parse_process_uss_req(u_int8_t *uss_req_data, u_int8_t length) { int rc = 1; + int num_chars; u_int8_t dcs; - /* FIXME: properly parse out the initial tag and length, then the data-coding scheme and finally the text - - following piece of code uses hard-coded offsets into the data */ - dcs = uss_req_data[7]; - DEBUGP(DMM, "Data coding scheme = 0x%2.2X\n", dcs); // temporary - - int num_7_bit_chars = (uss_req_data[9] * 8) / 7; - gsm_7bit_decode(ussd_string_buff, &(uss_req_data[10]), num_7_bit_chars); +// DEBUGP(DMM, "USSD request params %s\n", hexdump(uss_req_data, length)); + /* FIXME: most phones send USSD text as a 7-bit encoded octet string; the following code + also handles the case of plain ASCII text (IA5String), but other encodings might be used */ + if(uss_req_data[0] == GSM_0480_SEQUENCE_TAG) + { + if(uss_req_data[2] == ASN1_OCTET_STRING_TAG) + { + dcs = uss_req_data[4]; +// DEBUGP(DMM, "Data coding scheme = 0x%2.2X\n", dcs); + if((dcs == 0x0F) && (uss_req_data[5] == ASN1_OCTET_STRING_TAG)) + { + num_chars = (uss_req_data[6] * 8) / 7; + gsm_7bit_decode(ussd_string_buff, &(uss_req_data[7]), num_chars); + } + } + } + else if(uss_req_data[0] == ASN1_IA5_STRING_TAG) + { + num_chars = uss_req_data[1]; + memcpy(ussd_string_buff, &(uss_req_data[2]), num_chars); + } return rc; } -/* !!! Not yet complete or even partly working, causes a test phone to reboot! */ int gsm0480_send_ussd_response(struct msgb *in_msg, const char* response_text) { struct msgb *msg = gsm48_msgb_alloc(); struct gsm48_hdr *gh; - struct gsm_network *net = in_msg->lchan->ts->trx->bts->network; u_int8_t *ptr8; - int response_len, response_pad; + int response_len; + response_len = strlen(response_text); + + msg->bts_link = in_msg->bts_link; msg->lchan = in_msg->lchan; gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); - gh->proto_discr = GSM48_PDISC_NC_SS; - gh->msg_type = GSM0480_MTYPE_FACILITY; - -/* FIXME: Need to add lots of stuff here to build up a valid USSD - - GSM0480_IE_FACILITY, GSM0480_CTYPE_INVOKE(?), GSM0480_COMPIDTAG_INVOKE_ID, - GSM0480_OPERATION_CODE, GSM0480_OP_CODE_PROCESS_USS_REQ(?) */ - - response_len = (strlen(response_text)*7)/8; - response_pad = (8 - strlen(net->name_long)*7)%8; - if (response_pad > 0) - response_len++; - /* 10.5.3.5a */ - ptr8 = msgb_put(msg, 19); + gh->proto_discr = GSM48_PDISC_NC_SS | last_transaction_id | 0x80; // TI direction = 1 + gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE; + + ptr8 = msgb_put(msg, 14); ptr8[0] = GSM0480_IE_FACILITY; - ptr8[1] = response_len + 17; + ptr8[1] = response_len + 12; ptr8[2] = GSM0480_CTYPE_RETURN_RESULT; - ptr8[3] = response_len + 15; + ptr8[3] = response_len + 10; ptr8[4] = GSM0480_COMPIDTAG_INVOKE_ID; ptr8[5] = 1; - ptr8[6] = 0x80; // invoke-ID -128 - ptr8[7] = 0x30; // don't yet understand where this comes from - ptr8[8] = response_len + 10; + ptr8[6] = last_invoke_id; + ptr8[7] = GSM_0480_SEQUENCE_TAG; + ptr8[8] = response_len + 5; ptr8[9] = GSM0480_OPERATION_CODE; ptr8[10] = 1; - ptr8[11] = GSM0480_OP_CODE_PROCESS_USS_REQ; - ptr8[12] = 0x30; // don't yet understand where this comes from - ptr8[13] = response_len + 5; - ptr8[14] = 0x04; // indicates DCS to follow - ptr8[15] = 1; // length of DCS - ptr8[16] = 0x0F; // DCS - ptr8[17] = 0x04; // indicates string to follow - ptr8[18] = response_len; + ptr8[11] = GSM0480_OP_CODE_PROCESS_USS_DATA; + ptr8[12] = ASN1_IA5_STRING_TAG; + ptr8[13] = response_len; ptr8 = msgb_put(msg, response_len); - gsm_7bit_encode(ptr8, response_text); + memcpy(ptr8, response_text, response_len); - DEBUGP(DMM, "USSD response %s\n", hexdump(msg->data, msg->len)); // preliminary! Just see what we're sending... +// DEBUGP(DMM, "USSD response %s\n", hexdump(msg->data, msg->len)); // temporary, just to see what we're sending back - return -EINVAL; /* Temporary */ -// return gsm48_sendmsg(msg, NULL); + return gsm48_sendmsg(msg, NULL); } -/* !!! Not yet complete or even partly working */ -int gsm0480_send_ussd_error(struct msgb *in_msg) +int gsm0480_send_ussd_reject(struct msgb *in_msg) { - return -EINVAL; + struct msgb *msg = gsm48_msgb_alloc(); + struct gsm48_hdr *gh; + u_int8_t *ptr8; + + msg->bts_link = in_msg->bts_link; + msg->lchan = in_msg->lchan; + + gh = (struct gsm48_hdr *) msgb_put(msg, sizeof(*gh)); + gh->proto_discr = GSM48_PDISC_NC_SS | last_transaction_id | 0x80; // TI direction = 1 + gh->msg_type = GSM0480_MTYPE_RELEASE_COMPLETE; + + ptr8 = msgb_put(msg, 10); + ptr8[0] = GSM0480_IE_FACILITY; + ptr8[1] = 8; + ptr8[2] = GSM0480_CTYPE_REJECT; + ptr8[3] = 6; + ptr8[4] = GSM0480_COMPIDTAG_INVOKE_ID; + ptr8[5] = 1; + ptr8[6] = last_invoke_id; + ptr8[7] = GSM_0480_PROBLEM_CODE_TAG_GENERAL; + ptr8[8] = 1; + ptr8[9] = GSM_0480_GEN_PROB_CODE_UNRECOGNISED; + +// DEBUGP(DMM, "USSD reject %s\n", hexdump(msg->data, msg->len)); // temporary, just to see what we're sending back + + return gsm48_sendmsg(msg, NULL); } diff --git a/openbsc/src/ussd.c b/openbsc/src/ussd.c old mode 100644 new mode 100755 index 26b4686..761a0e7 --- a/openbsc/src/ussd.c +++ b/openbsc/src/ussd.c @@ -1,4 +1,4 @@ -/* Handler for mobile-originated USSDs */ +/* Network-specific handling of mobile-originated USSDs. */ /* (C) 2008-2009 by Harald Welte <laforge(a)gnumonks.org> * (C) 2008, 2009 by Holger Hans Peter Freyther <zecke(a)selfish.org> @@ -31,13 +31,17 @@ #include <openbsc/gsm_subscriber.h> #include <openbsc/debug.h> -#define USSD_TEXT_OWN_NUMBER "*#100#" +const char USSD_TEXT_OWN_NUMBER[] = "*#100#"; static int send_own_number(struct msgb *msg); int handle_rcv_ussd(struct msgb *msg) { char* ussd_text_rcvd = gsm0480_rcv_ussd(msg); + + if(ussd_text_rcvd[0] == 0xFF) // Release-Complete + return 0; + DEBUGP(DMM, "Received USSD text %s\n", ussd_text_rcvd); // show text payload entered on MS if(strstr(USSD_TEXT_OWN_NUMBER, ussd_text_rcvd) != NULL) @@ -48,12 +52,15 @@ int handle_rcv_ussd(struct msgb *msg) else { DEBUGP(DMM, "Unhandled USSD %s\n", ussd_text_rcvd); - return gsm0480_send_ussd_error(msg); + return gsm0480_send_ussd_reject(msg); } } static int send_own_number(struct msgb *msg) { + char response_string[] = "Your extension is xxxxx"; + char* own_number = msg->lchan->subscr->extension; - return gsm0480_send_ussd_response(msg, own_number); + memcpy(response_string + 18, own_number, 5); + return gsm0480_send_ussd_response(msg, response_string); } -- 1.6.0.4 --------------040900030502000202050609--

15 years, 10 months

audio support for application interface with nanoBTS

by Andreas.Eversberg

hi, here is the patch to support audio exchange between application interface and nanoBTS. the patch changes the audio format from TRAU frame format to RTP payload format on the application interface. also the BS11 TRAU frame is converted to/from RTP payload format (inside trau_mux.c), so an application does not have to care about what BTS is used. here is the format as defined by RFC: (just fyi) first byte has the magic value of 0xd0 plus four upper bits of the LARc[0] element as lower bits. second byte has the lower two bits of the LARc[0] element as upper bits and the upper bits of LARc[1] element as lower bits. third byte has the lower four bits of LARc[1] element as upper bits and so on... this format can directly be transcoded with the open source lossy gsm codec. the rtp_proxy.c now parses RTP frames and generates them. for easier code, i just mirrored the received RTCP frames back to the nanoBTS, mangled of yourse. (oops, maybe i need to change some synchronization source identifiers.) i think there is no problem with that right now. because RFC requires special synchronization source (ssrc) generation, i added md5 code and the (funny) random number generator. (see rtp_proxy.c random32()) as soon as the patch is applied, i will also check in linux-call-router modification for the new audio frame format. note that this code is just quickly tested, it works with both BS11 and nanoBTS and should not crash on corrupt or extended RTP data. the delay of audio data sent to nanoBTS was > 0.5 seconds. i think this is too much. maybe it is because i seamlessly increment the timestamp value in the RTP frame, even if the application dropps (delays) frames. regards, andreas

15 years, 11 months

AW: md5 / randomness (Re: audio support for application interfacewith nanoBTS)

by Andreas.Eversberg

On Sunday 04 October 2009 13:51:29 Harald Welte wrote: > one further note on the missing md5 file: > > As it seems it is only used to generate a pseudo-random 32bit value > for use in the SSRC: I'd rather not introduce a copy of MD5 for that. > > There are two options to take: > > 1) simply use the same [not very random] method as we use for the TMSI > > 2) introduce a dependency to openssl and use that. Given that nanoBTS > also support OML/RSL over SSL/TLS, I think sooner or later we will > have to add that dependency anyway. hi, i think that very good random is not required. in our case we don't have large scale RTP conferences with thousands of sources. we have to choose a random number that just differs from the one selected by nanoBTS. (the RTP session will fail afer some seconds when using same SSRC.) andreas

15 years, 11 months

[PATCH] abis_nm: Fix ACTIVATE SW parameters

by Sylvain Munaut

From: Sylvain Munaut <tnt(a)246tNt.com> The previous code only sent the FILE_ID tag data part, but according to the GSM 12.21 spec, section 8.3.6, the full SW Description 'object' must be sent so that includes the NM_ATT_SW_DESCR tag, the whole FILE_ID and the whole FILE_VERSION (including tags & length fields). Note that functionnaly on a nanoBTS 139 I couldn't see any difference ... whatever I send in there it works ... Signed-off-by: Sylvain Munaut <tnt(a)246tNt.com> --- openbsc/src/abis_nm.c | 13 ++++++++++--- 1 files changed, 10 insertions(+), 3 deletions(-) diff --git a/openbsc/src/abis_nm.c b/openbsc/src/abis_nm.c index 35ed8db..a450452 100755 --- a/openbsc/src/abis_nm.c +++ b/openbsc/src/abis_nm.c @@ -857,6 +857,7 @@ static int abis_nm_rx_sw_act_req(struct msgb *mb) const u_int8_t *sw_config; int sw_config_len; int file_id_len; + int file_ver_len; int nack = 0; int ret; @@ -889,18 +890,24 @@ static int abis_nm_rx_sw_act_req(struct msgb *mb) if (sw_config[0] != NM_ATT_SW_DESCR) DEBUGP(DNM, "SW_DESCR attribute identifier not found!\n"); + if (sw_config[1] != NM_ATT_FILE_ID) DEBUGP(DNM, "FILE_ID attribute identifier not found!\n"); file_id_len = sw_config[2] * 256 + sw_config[3]; + if (sw_config[4+file_id_len] != NM_ATT_FILE_VERSION) + DEBUGP(DNM, "FILE_VERSION attribute identifier not found!\n"); + file_ver_len = sw_config[5+file_id_len] * 256 + sw_config[6+file_id_len]; + /* Assumes first SW file in list is the one to be activated */ - /* sw_config + 4 to skip over 2 attribute ID bytes and 16-bit length field */ + /* The +7 in length is to account for the 3 tags and 2 length fields */ + /* (see GSM 12.21 - 9.4.{62,18,19} for details */ return ipacc_sw_activate(mb->trx->bts, foh->obj_class, foh->obj_inst.bts_nr, foh->obj_inst.trx_nr, foh->obj_inst.ts_nr, - sw_config + 4, - file_id_len); + sw_config, + 7 + file_id_len + file_ver_len); } /* Receive a CHANGE_ADM_STATE_ACK, parse the TLV and update local state */ -- 1.6.4

15 years, 11 months

AW: audio support for application interface with nanoBTS

by Andreas.Eversberg

> One thing I noted immediately: The newly-introduced md5c.c file is missing from your diff. Can you please re-submit with that file? Thanks. >(in case you work with git, first 'git add' the file, then 'git diff HEAD', if all your changes are not yet committed) ok, again a corrected verion of the rtp.patch (hopefully complete)

15 years, 11 months

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OpenBSC October 2009