OpenBSC

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4172 discussions

ip.access Abis-over-IP dissector now part of wireshark

by Harald Welte

Hi! JFYI: My dissector for the Abis-IP adaption layer of ip.access has been merged into wireshark (as of svn revision 29059). -- - 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)

16 years, 1 month

Cleanup some parsing in the mncc.c code

by Holger Freyther

Hey Harald, did you have this in mind when mentioning that the parsing of the data derived informations could be driven by a struct? z. From 594cf586dedaecfc5e755a6d0fc9ac69dc513e91 Mon Sep 17 00:00:00 2001 From: Holger Hans Peter Freyther <zecke(a)selfish.org> Date: Mon, 29 Jun 2009 17:21:37 +0200 Subject: [PATCH] Generic data derived informations parsing... Declare what elements to parse in a struct and then trigger the generic parsing routine. --- openbsc/src/msc_mncc.c | 211 ++++++++++++++++++++--------------------------- 1 files changed, 90 insertions(+), 121 deletions(-) diff --git a/openbsc/src/msc_mncc.c b/openbsc/src/msc_mncc.c index b54e184..5329fa1 100644 --- a/openbsc/src/msc_mncc.c +++ b/openbsc/src/msc_mncc.c @@ -112,6 +112,39 @@ static const char *cc_state_names[] = { "illegal state 31", }; +typedef int (*dd_decoder)(void* data, const u_int8_t *lv); + +struct dd_parser { + int information_element; + int mncc_field; + int offset; + dd_decoder decoder; +}; + +#define DECLARE_DECODER3(IE_NAME, M_NAME, name) \ + { .information_element = GSM48_IE_##IE_NAME, \ + .mncc_field = MNCC_F_##M_NAME, \ + .offset = offsetof(struct gsm_mncc, name), \ + .decoder = (dd_decoder)decode_##name, \ + } + + +#define DECLARE_DECODER(NAME, name) \ + DECLARE_DECODER3(NAME, NAME, name) + +static void parse_data_derived_information(struct dd_parser *parser, const int length, + struct tlv_parsed *tp, struct gsm_mncc *rel) +{ + int i; + + for (i = 0; i < length; ++i) { + if (TLVP_PRESENT(tp, parser[i].information_element)) { + rel->fields |= parser[i].mncc_field; + parser[i].decoder(rel + parser[i].offset, + TLVP_VAL(tp, parser[i].information_element)-1); + } + } +} static int mncc_handle_lchan_signal(unsigned int subsys, unsigned int signal, void *handler_data, void *signal_data) @@ -1420,31 +1453,15 @@ static int msc_cc_rx_disconnect(struct gsm_trans *trans, struct msgb *msg) memset(&disc, 0, sizeof(struct gsm_mncc)); disc.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_CAUSE, 0); - /* cause */ - if (TLVP_PRESENT(&tp, GSM48_IE_CAUSE)) { - disc.fields |= MNCC_F_CAUSE; - decode_cause(&disc.cause, - TLVP_VAL(&tp, GSM48_IE_CAUSE)-1); - } - /* facility */ - if (TLVP_PRESENT(&tp, GSM48_IE_FACILITY)) { - disc.fields |= MNCC_F_FACILITY; - decode_facility(&disc.facility, - TLVP_VAL(&tp, GSM48_IE_FACILITY)-1); - } - /* user-user */ - if (TLVP_PRESENT(&tp, GSM48_IE_USER_USER)) { - disc.fields |= MNCC_F_USERUSER; - decode_useruser(&disc.useruser, - TLVP_VAL(&tp, GSM48_IE_USER_USER)-1); - } - /* ss-version */ - if (TLVP_PRESENT(&tp, GSM48_IE_SS_VERS)) { - disc.fields |= MNCC_F_SSVERSION; - decode_ssversion(&disc.ssversion, - TLVP_VAL(&tp, GSM48_IE_SS_VERS)-1); - } + static struct dd_parser parser[] = { + DECLARE_DECODER(CAUSE, cause), + DECLARE_DECODER(FACILITY, facility), + DECLARE_DECODER3(USER_USER, USERUSER, useruser), + DECLARE_DECODER3(SS_VERS, SSVERSION, ssversion), + }; + + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &disc); return mncc_recvmsg(trans->network, trans, MNCC_DISC_IND, &disc); } @@ -1509,30 +1526,15 @@ static int msc_cc_rx_release(struct gsm_trans *trans, struct msgb *msg) memset(&rel, 0, sizeof(struct gsm_mncc)); rel.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, 0, 0); - /* cause */ - if (TLVP_PRESENT(&tp, GSM48_IE_CAUSE)) { - rel.fields |= MNCC_F_CAUSE; - decode_cause(&rel.cause, - TLVP_VAL(&tp, GSM48_IE_CAUSE)-1); - } - /* facility */ - if (TLVP_PRESENT(&tp, GSM48_IE_FACILITY)) { - rel.fields |= MNCC_F_FACILITY; - decode_facility(&rel.facility, - TLVP_VAL(&tp, GSM48_IE_FACILITY)-1); - } - /* user-user */ - if (TLVP_PRESENT(&tp, GSM48_IE_USER_USER)) { - rel.fields |= MNCC_F_USERUSER; - decode_useruser(&rel.useruser, - TLVP_VAL(&tp, GSM48_IE_USER_USER)-1); - } - /* ss-version */ - if (TLVP_PRESENT(&tp, GSM48_IE_SS_VERS)) { - rel.fields |= MNCC_F_SSVERSION; - decode_ssversion(&rel.ssversion, - TLVP_VAL(&tp, GSM48_IE_SS_VERS)-1); - } + + static struct dd_parser parser[] = { + DECLARE_DECODER(CAUSE, cause), + DECLARE_DECODER(FACILITY, facility), + DECLARE_DECODER3(USER_USER, USERUSER, useruser), + DECLARE_DECODER3(SS_VERS, SSVERSION, ssversion), + }; + + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &rel); if (trans->state == GSM_CSTATE_RELEASE_REQ) { /* release collision 5.4.5 */ @@ -1598,30 +1600,15 @@ static int msc_cc_rx_release_compl(struct gsm_trans *trans, struct msgb *msg) memset(&rel, 0, sizeof(struct gsm_mncc)); rel.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, 0, 0); - /* cause */ - if (TLVP_PRESENT(&tp, GSM48_IE_CAUSE)) { - rel.fields |= MNCC_F_CAUSE; - decode_cause(&rel.cause, - TLVP_VAL(&tp, GSM48_IE_CAUSE)-1); - } - /* facility */ - if (TLVP_PRESENT(&tp, GSM48_IE_FACILITY)) { - rel.fields |= MNCC_F_FACILITY; - decode_facility(&rel.facility, - TLVP_VAL(&tp, GSM48_IE_FACILITY)-1); - } - /* user-user */ - if (TLVP_PRESENT(&tp, GSM48_IE_USER_USER)) { - rel.fields |= MNCC_F_USERUSER; - decode_useruser(&rel.useruser, - TLVP_VAL(&tp, GSM48_IE_USER_USER)-1); - } - /* ss-version */ - if (TLVP_PRESENT(&tp, GSM48_IE_SS_VERS)) { - rel.fields |= MNCC_F_SSVERSION; - decode_ssversion(&rel.ssversion, - TLVP_VAL(&tp, GSM48_IE_SS_VERS)-1); - } + + static struct dd_parser parser[] = { + DECLARE_DECODER(CAUSE, cause), + DECLARE_DECODER(FACILITY, facility), + DECLARE_DECODER3(USER_USER, USERUSER, useruser), + DECLARE_DECODER3(SS_VERS, SSVERSION, ssversion), + }; + + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &rel); if (trans->callref) { switch (trans->state) { @@ -1684,19 +1671,13 @@ static int msc_cc_rx_facility(struct gsm_trans *trans, struct msgb *msg) memset(&fac, 0, sizeof(struct gsm_mncc)); fac.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_FACILITY, 0); - /* facility */ - if (TLVP_PRESENT(&tp, GSM48_IE_FACILITY)) { - fac.fields |= MNCC_F_FACILITY; - decode_facility(&fac.facility, - TLVP_VAL(&tp, GSM48_IE_FACILITY)-1); - } - /* ss-version */ - if (TLVP_PRESENT(&tp, GSM48_IE_SS_VERS)) { - fac.fields |= MNCC_F_SSVERSION; - decode_ssversion(&fac.ssversion, - TLVP_VAL(&tp, GSM48_IE_SS_VERS)-1); - } + static struct dd_parser parser[] = { + DECLARE_DECODER(FACILITY, facility), + DECLARE_DECODER3(SS_VERS, SSVERSION, ssversion), + }; + + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &fac); return mncc_recvmsg(trans->network, trans, MNCC_FACILITY_IND, &fac); } @@ -1807,12 +1788,11 @@ static int msc_cc_rx_start_dtmf(struct gsm_trans *trans, struct msgb *msg) dtmf.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, 0, 0); /* keypad facility */ - if (TLVP_PRESENT(&tp, GSM48_IE_KPD_FACILITY)) { - dtmf.fields |= MNCC_F_KEYPAD; - decode_keypad(&dtmf.keypad, - TLVP_VAL(&tp, GSM48_IE_KPD_FACILITY)-1); - } + static struct dd_parser parser[] = { + DECLARE_DECODER3(KPD_FACILITY, KEYPAD, keypad), + }; + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &dtmf); return mncc_recvmsg(trans->network, trans, MNCC_START_DTMF_IND, &dtmf); } @@ -1884,15 +1864,12 @@ static int msc_cc_rx_modify(struct gsm_trans *trans, struct msgb *msg) memset(&modify, 0, sizeof(struct gsm_mncc)); modify.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_BEARER_CAP, 0); - /* bearer capability */ - if (TLVP_PRESENT(&tp, GSM48_IE_BEARER_CAP)) { - modify.fields |= MNCC_F_BEARER_CAP; - decode_bearer_cap(&modify.bearer_cap, - TLVP_VAL(&tp, GSM48_IE_BEARER_CAP)-1); - } + static struct dd_parser parser[] = { + DECLARE_DECODER(BEARER_CAP, bearer_cap), + }; + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &modify); new_cc_state(trans, GSM_CSTATE_MO_ORIG_MODIFY); - return mncc_recvmsg(trans->network, trans, MNCC_MODIFY_IND, &modify); } @@ -1928,15 +1905,12 @@ static int msc_cc_rx_modify_complete(struct gsm_trans *trans, struct msgb *msg) memset(&modify, 0, sizeof(struct gsm_mncc)); modify.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_BEARER_CAP, 0); - /* bearer capability */ - if (TLVP_PRESENT(&tp, GSM48_IE_BEARER_CAP)) { - modify.fields |= MNCC_F_BEARER_CAP; - decode_bearer_cap(&modify.bearer_cap, - TLVP_VAL(&tp, GSM48_IE_BEARER_CAP)-1); - } + static struct dd_parser parser[] = { + DECLARE_DECODER(BEARER_CAP, bearer_cap), + }; + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &modify); new_cc_state(trans, GSM_CSTATE_ACTIVE); - return mncc_recvmsg(trans->network, trans, MNCC_MODIFY_CNF, &modify); } @@ -1970,19 +1944,13 @@ static int msc_cc_rx_modify_reject(struct gsm_trans *trans, struct msgb *msg) memset(&modify, 0, sizeof(struct gsm_mncc)); modify.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_BEARER_CAP, GSM48_IE_CAUSE); - /* bearer capability */ - if (TLVP_PRESENT(&tp, GSM48_IE_BEARER_CAP)) { - modify.fields |= GSM48_IE_BEARER_CAP; - decode_bearer_cap(&modify.bearer_cap, - TLVP_VAL(&tp, GSM48_IE_BEARER_CAP)-1); - } - /* cause */ - if (TLVP_PRESENT(&tp, GSM48_IE_CAUSE)) { - modify.fields |= MNCC_F_CAUSE; - decode_cause(&modify.cause, - TLVP_VAL(&tp, GSM48_IE_CAUSE)-1); - } + + static struct dd_parser parser[] = { + DECLARE_DECODER(BEARER_CAP, bearer_cap), + DECLARE_DECODER(CAUSE, cause), + }; + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &modify); new_cc_state(trans, GSM_CSTATE_ACTIVE); return mncc_recvmsg(trans->network, trans, MNCC_MODIFY_REJ, &modify); @@ -2070,12 +2038,13 @@ static int msc_cc_rx_userinfo(struct gsm_trans *trans, struct msgb *msg) memset(&user, 0, sizeof(struct gsm_mncc)); user.callref = trans->callref; tlv_parse(&tp, &rsl_att_tlvdef, gh->data, payload_len, GSM48_IE_USER_USER, 0); - /* user-user */ - if (TLVP_PRESENT(&tp, GSM48_IE_USER_USER)) { - user.fields |= MNCC_F_USERUSER; - decode_useruser(&user.useruser, - TLVP_VAL(&tp, GSM48_IE_USER_USER)-1); - } + + static struct dd_parser parser[] = { + DECLARE_DECODER3(USER_USER, USERUSER, useruser), + }; + + parse_data_derived_information(&parser[0], ARRAY_SIZE(parser), &tp, &user); + /* more data */ if (TLVP_PRESENT(&tp, GSM48_IE_MORE_DATA)) user.more = 1; -- 1.6.3.1

16 years, 1 month

CCCH

by Eric Cathelinaud

Hi everybody I just would like to be sure that the paging is only sent on TS0 with OpenBSC, that is to say PCH (which is on CCCH) is only sent on TS0. I read that it could be sent on more time slots (TS2, TS4 and TS6 also) in the GSM specifications. Is it the case in the soft or you just keep the normal multiplexage setting (TS0 only for CCCH+BCCH, 1 slot for dedicated channels and 6 slots for the traffic channels)? Thanks Eric Cathelinaud

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Dieter Spaar

Hello Nordin, On Tue, 07 Jul 2009 16:31:36 +0200, "Nordin" <bouchtaoui(a)gmail.com> wrote: > > But this means that your HTC needs more relevant GPRS settings before > deciding to register. So it than searches for altenatives, but since the > BA list is empty it starts all over again and the whole process repeats, > which might result in a long procedure before it gives up. This is what > it might could be the reason, I'm not sure. If the GPRS Indicator is set, SYSTEM INFORMATION 13 is needed to describe the GPRS properties. But SYSTEM INFORMATION 13 is not set yet (not possible for the BS-11 anyway) so the phone won't find it. Probably some phones don't care about it but some others insist to find it before going to register. This is probably one of the many places where there is no rule in the specification what should be done in such a situation so its up to the developer of the firmware (the phone could register and return an error only when GPRS is actually needed for a data connection). Of course I don't mean that the specification is incomplete, it just expects that certain things are done "right" (who would expect that people outside of the mobile phone industry play with a BTS ;-). Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Dieter Spaar

Hello Nordin, On Mon, 06 Jul 2009 12:00:27 +0200, "Nordin" <bouchtaoui(a)gmail.com> wrote: > > I tried the parameters as you suggested for SI 1 as well as SI3, but > with no success. But I'm still curious if someone else on the list > registered a PDA-like mobilephone (with GPRS support) to his BTS > (BS11/nanoBTS1800). If so, I would like to try out his/her SI's settings. > With the modification I have sent I can register a HTC Touch Pro to the BS11 and the nanoBTS 1800. If GPRS is set in SYSTEM INFORMATION 3, the phone will not register. The process is a bit unstable, if the phone is powered on, the location update works as expected, if I try to register manually, it sometime fails without actually communication with the BTS. I don't know the reason for this behaviour yet. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

16 years, 1 month

Git repository via HTTP (port 80)

by Nordin

Hello guys, I made a repository for the OpenBSC project, see: http://repo.or.cz/w/openbsc.git Now you can update/clone the project from http://repo.or.cz/r/openbsc.git, like this: git clone http://repo.or.cz/r/openbsc.git It will be updated every hour (mirror mode). I needed that because our firewall blocks the git port 9418. Thank you for the tip Holger Freyther :) If you have any questions, don't hestitate to ask.

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Dieter Spaar

Hello Nordin, On Fri, 03 Jul 2009 11:21:59 +0200, "Nordin" <bouchtaoui(a)gmail.com> wrote: > > Since we haven't done anything for GPRS support, this might be the > reason why a location update is not performed with bsc_hack. The problem you experience with the nanoBTS 1800 most certainly comes from an invalid System Information Type 1. It uses the bitmap type for the channel description which is only valid for GSM900. So all the phones should try to register with the BS-11 but for the nanoBTS 1800 phones which strictly confirm to the specification will ignore it and not try to register (there are some phones which don't care). You can try the "system_information" git branch from Harald, it will most certainly solve the problem. > P.S.: Is everybody on holiday...:) I guess the people are just busy... Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Nordin

I tried the parameters as you suggested for SI 1 as well as SI3, but with no success. But I'm still curious if someone else on the list registered a PDA-like mobilephone (with GPRS support) to his BTS (BS11/nanoBTS1800). If so, I would like to try out his/her SI's settings. I still don't have the latest version as at the moment our firewall doesn't allow to (I ask the networkadmin later for that).

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Dieter Spaar

Hello Nordin, On Fri, 03 Jul 2009 14:44:50 +0200, "Nordin" <bouchtaoui(a)gmail.com> wrote: > > I hope this will at least try to do a LOCATION UPDATE REQUEST. > But it suprises me that older mobilephones don't care about SI 1 (and > maybe more information on the BCCH) and just try to register whatever in > the BCCH is. I have further investigated the problem. Besides the fact that the channel allocation in SYSTEM INFORMATION 1 is not correct for GSM 1800, this is probably not the reason for the problem. Most certainly its just one wrong bit, the GPRS indicator in the SYSTEM INFORMATION 3 rest octets. The current setting is 0x80, 0x00, 0x00, 0x2B but it should be 0x80, 0x00, 0x08, 0x2B What might lead to some confusion is the meaning of "L" and "H" in the specification of CSN.1. For the rest octets the bit value is determined by a comparsion (XOR) to the padding byte 0x2B. So the value 0x08 above actually means "L" for the GPRS indicator, which means "No GPRS". Its seem that some phones are really sensible to this setting, some other GPRS capable phones just don't care and register to the network even if there is no GPRS. Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

16 years, 1 month

Re: OpenBSC with 2.5G or 3G mobile devices support? / Tested Phones

by Dieter Spaar

Hello Harald, On Sun, 5 Jul 2009 04:42:20 +0200, "Harald Welte" <laforge(a)gnumonks.org> wrote: > > where did you find this XOR? I just searched through 04.07 and 04.08 and > didn't find any indication thereof. Sure, the padding bit sequence ix 0x2b, so > all spare bits have to be padded with that. But where did you get the XOR > from? I started to search deeper because I was a bit confused how the Message Decoding Tool from Joachim Goeller interpreted the rest octets. I looked at some phone firmware how they do it and found it there. Later I also found a good explanation at http://csn1.info (they sell a tool which can be used to generate message parsing source code for various specifications). > Also, this would mean that if we put explicitly 0x2b into the padding of > our messages, then it would result in all-zero 0x00 on the air, since > > 0x2b xor 0x2b == 0x00 The XOR is actually only used for "L" and "H", basically it means that if a bit at an "L"/"H" position is different from the padding sequence, its an "H". At least this is how I understand it. > I'm now looking at an actual abis trace from a production cell with GPRS > enabled, and it has > > "0x80, 0x00, 0x80, 0x0b" Here is how I would interpret it according to GSM 04.08, 10.5.2.34: Selection Parameter: byte 0: 0x80 ^ 0x2B = 0xAB, (bit 7) -> H (15 bits for parameter follow) Power Offset: byte 2: 0x80 ^ 0x2B = 0xAB, (bit 7) -> H ( 2 bits for parameter follow) System Information 2ter Indicator: byte 2: 0x80 ^ 0x2B = 0xAB, (bit 4) -> L (has no parameters) Early Classmark Sending Control: byte 2: 0x80 ^ 0x2B = 0xAB, (bit 3) -> H (has no parameters) Scheduling if and where: byte 2: 0x80 ^ 0x2B = 0xAB, (bit 2) -> L GPRS Indicator: byte 2: 0x80 ^ 0x2B = 0xAB, (bit 1) -> H ( 4 bits for parameter follow) > During early start of the BTS, SI3 rest octets are set to > > "0x80, 0x00, 0x83, 0x2b" The only difference is that at this stage GPRS is not yet set: GPRS Indicator: byte 2: 0x83 ^ 0x2B = 0xA8, (bit 1) -> L Best regards, Dieter -- Dieter Spaar, Germany spaar(a)mirider.augusta.de

16 years, 1 month

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