OpenBSC February 2014

openbsc@lists.osmocom.org

20 participants
31 discussions

TOMORROW: Osmocom Berlin User Group meeting
by dexter 26 Feb '14

26 Feb '14

Hi All. It's time Again! This is the announcement for the next Osmocom Berlin meeting. Tomorrow, 8pm @ CCC Berlin, Marienstr. 11, 10117 Berlin There is no formal presentation scheduled for this meeting. If you are interested to show up, feel free to do so. There is no registration required. The meeting is free as in "free beer", despite no actual free beer being around. I am looking forward to see you there! regards. Philipp

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[PATCH] db: use WAL journaling mode for higher concurrency
by Alexey Shamrin 22 Feb '14

22 Feb '14

SQLite uses DELETE journaling mode by default. It became a problem on a real-world, actively used network (several hundred subscribers, several thousands SMS per day). Some location updates and SMS delivery marks were not getting written because database file was locked: 2013-12-13_07:26:10.10665 <0002> gsm_subscriber.c:362 Subscriber 334020422525672 ATTACHED LAC=3 2013-12-13_07:26:10.10668 <000d> db.c:170 DBI: 5: database is locked 2013-12-13_07:26:10.10865 <000d> db.c:969 Failed to update Subscriber (by IMSI). Switching to WAL mode fixed the problem. WAL journaling mode is persistent; it stays in effect after closing and reopening the database. WAL mode database requires SQLite >= 3.7.0. All credit belongs Ivan Kluchnikov who diagnosed and fixed this issue. --- openbsc/src/libmsc/db.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) diff --git a/openbsc/src/libmsc/db.c b/openbsc/src/libmsc/db.c index e720c78..3a989d4 100644 --- a/openbsc/src/libmsc/db.c +++ b/openbsc/src/libmsc/db.c @@ -232,11 +232,18 @@ static int db_configure(void) dbi_result result; result = dbi_conn_query(conn, + "PRAGMA journal_mode = WAL"); + if (!result) + LOGP(DDB, LOGL_NOTICE, "Warning: failed to set journal_mode = WAL.\n"); + else + dbi_result_free(result); + + result = dbi_conn_query(conn, "PRAGMA synchronous = FULL"); if (!result) return -EINVAL; - dbi_result_free(result); + return 0; } -- 1.7.7.5 (Apple Git-26)

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[PATCH 1/5] bts/vty: Use new vty_install_default() function, adjust prompts
by Jacob Erlbeck 22 Feb '14

22 Feb '14

This patch removes the local 'end' and 'exit' implementations (which aren't used anyway) and uses the generic ones provided by libosmocore instead, which are enabled automatically when vty_install_default() is used. The prompt strings are modified to match those in libosmocore/openbsc. Ticket: OW#952 Sponsored-by: On-Waves ehf --- src/common/vty.c | 39 ++++----------------------------------- 1 file changed, 4 insertions(+), 35 deletions(-) diff --git a/src/common/vty.c b/src/common/vty.c index 5eddc8d..d818f3f 100644 --- a/src/common/vty.c +++ b/src/common/vty.c @@ -71,37 +71,6 @@ int bts_vty_is_config_node(struct vty *vty, int node) } } -gDEFUN(ournode_exit, ournode_exit_cmd, "exit", - "Exit current node, go down to provious node") -{ - switch (vty->node) { - case TRX_NODE: - vty->node = BTS_NODE; - { - struct gsm_bts_trx *trx = vty->index; - vty->index = trx->bts; - } - break; - default: - break; - } - return CMD_SUCCESS; -} - -gDEFUN(ournode_end, ournode_end_cmd, "end", - "End current mode and change to enable mode") -{ - switch (vty->node) { - default: - vty_config_unlock(vty); - vty->node = ENABLE_NODE; - vty->index = NULL; - vty->index_sub = NULL; - break; - } - return CMD_SUCCESS; -} - static const char osmobts_copyright[] = "Copyright (C) 2010, 2011 by Harald Welte, Andreas Eversberg and On-Waves\r\n" "License AGPLv3+: GNU AGPL version 3 or later <http://gnu.org/licenses/agpl-3.0.html>\r\n" @@ -140,13 +109,13 @@ struct gsm_bts *gsm_bts_num(struct gsm_network *net, int num) static struct cmd_node bts_node = { BTS_NODE, - "%s(bts)#", + "%s(config-bts)# ", 1, }; static struct cmd_node trx_node = { TRX_NODE, - "%s(trx)#", + "%s(config-bts-trx)# ", 1, }; @@ -509,7 +478,7 @@ int bts_vty_init(const struct log_info *cat) install_node(&bts_node, config_write_bts); install_element(CONFIG_NODE, &cfg_bts_cmd); - install_default(BTS_NODE); + vty_install_default(BTS_NODE); install_element(BTS_NODE, &cfg_bts_unit_id_cmd); install_element(BTS_NODE, &cfg_bts_oml_ip_cmd); install_element(BTS_NODE, &cfg_bts_rtp_bind_ip_cmd); @@ -523,7 +492,7 @@ int bts_vty_init(const struct log_info *cat) /* add and link to TRX config node */ install_element(BTS_NODE, &cfg_bts_trx_cmd); install_node(&trx_node, config_write_dummy); - install_default(TRX_NODE); + vty_install_default(TRX_NODE); install_element(ENABLE_NODE, &bts_t_t_l_jitter_buf_cmd); -- 1.7.9.5

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LAPDm code issues (ladpm.c)
by Jacob Erlbeck 21 Feb '14

21 Feb '14

Hi LAPDm guys, while I was digging into the LAPDm code to find out, why a broken SABM message is sent on a SAPI3 establish SACCH request during an active call (leading to a delay of 3s between RSL EST request and response), I stumbled over the following: The initial SABM message (not the retransmitted one after T200) has a non-zero length and ends with 3 bytes that have been taken from the end of the RSL EST REQ message. The MS does not answer to this. Interestingly the second SABM message that gets sent after T200 (2s) has a length field of 0 and no trailing garbage. The difference lies in the way the msgb is handled. In rslms_rx_rll_est_req() the msg buffer passed from RSL is being used. In the case of IPA, the l2h is prepended by the 3 byte IPA header. Since all code in lapdm.c that handles RSL message seem to assume, that msg->data == msg->l2h, length computation is done based on that assumption in some places. In addition, msgb_pull() is used in a way that would also lead to undefined results in this case, e.g. in msgb_pull_l2h() just the difference between l2h and l3h is pulled from the beginning (msg->data). The main difficulty to find this, was that much msgb handling is done by manual access to the msgb fields. I'd really favor the use of the predefined macros/inlines instead of meddling around with the fields. I've added a function msgb_pull_to_l3() to msgb.h which just skips over everything in front of l3 (and therefore invalidates l2h and l1h) and replaced all calls to msgb_pull_l2h() by calls to msgb_pull_to_l3(). In addition, I replaced manual l3 length adjustment by calls to msgb_trim(). That alone fixed the SABM issue described above. See the jerlbeck/fixes/lapd-sms branch for details. But AFAICS there is still something to do: - The remaining msgb_pull() need to be checked (at least the one in l2_ph_data_ind() looks suspicious to me. - L3 length computation should be done with the macros, how it is done in lapdm_send_ph_data_req() is broken. - Why does lapd_msg_ctx have a length field that is not used? - ladp_test.c should be extended to check other execution paths, too. I've tried it for dummy packets and I didn't get it working without failing assertions (see below) - How l2/data/.. in a msg are expected to be used/set should be documented somewhere. - It should be clarified, whether all abis driver should reset the msg to start with l2. Cheers Jacob ====== The following patch still breaks the assertions, at least changing the l3len computation in lapdm_send_ph_data_req() influences but doesn't fix it. --- a/tests/lapd/lapd_test.c +++ b/tests/lapd/lapd_test.c @@ -123,8 +123,10 @@ static struct msgb *create_empty_msg(void) static struct msgb *create_dummy_data_req(void) { struct msgb *msg; + const int dummy_l1len = 3; msg = msgb_from_array(dummy1, sizeof(dummy1)); + msgb_push(msg, dummy_l1len); rsl_rll_push_l3(msg, RSL_MT_DATA_REQ, 0, 0, 1); return msg; }

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[PATCH 1/3] bsc_init: Check BTS configuration, BTS should not use duplicate ARFCNs
by Ivan Kluchnikov 21 Feb '14

21 Feb '14

--- openbsc/src/libbsc/bsc_init.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/openbsc/src/libbsc/bsc_init.c b/openbsc/src/libbsc/bsc_init.c index 8fd72cf..cd5ee58 100644 --- a/openbsc/src/libbsc/bsc_init.c +++ b/openbsc/src/libbsc/bsc_init.c @@ -351,6 +351,8 @@ static int inp_sig_cb(unsigned int subsys, unsigned int signal, static int bootstrap_bts(struct gsm_bts *bts) { int i, n; + struct gsm_bts_trx *cur_trx; + struct gsm_bts_trx *trx; if (bts->model->start && !bts->model->started) { int ret = bts->model->start(bts->network); @@ -394,6 +396,17 @@ static int bootstrap_bts(struct gsm_bts *bts) return -EINVAL; } + llist_for_each_entry(cur_trx, &bts->trx_list, list) { + llist_for_each_entry(trx, &bts->trx_list, list) { + if ((cur_trx->arfcn == trx->arfcn) && (cur_trx->nr != trx->nr)) { + LOGP(DNM, LOGL_ERROR, "BTS should not use duplicate ARFCNs. " + "Duplicate ARFCN = %d BTS = %d TRX = %d TRX = %d\n", + trx->arfcn, bts->nr, cur_trx->nr, trx->nr); + return -EINVAL; + } + } + } + if (bts->network->auth_policy == GSM_AUTH_POLICY_ACCEPT_ALL && !bts->si_common.rach_control.cell_bar) LOGP(DNM, LOGL_ERROR, "\nWARNING: You are running an 'accept-all' " -- 1.7.9.5

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[PATCH] rsl: Implement handling of rsl Delete Ind message
by Ivan Kluchnikov 18 Feb '14

18 Feb '14

If bsc receives Delete_Ind message from bts, bsc should release allocated channel, which was specified in dropped imm_assign message. --- openbsc/src/libbsc/abis_rsl.c | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/openbsc/src/libbsc/abis_rsl.c b/openbsc/src/libbsc/abis_rsl.c index f53ba84..ed6d8cd 100644 --- a/openbsc/src/libbsc/abis_rsl.c +++ b/openbsc/src/libbsc/abis_rsl.c @@ -1539,6 +1539,41 @@ static int rsl_rx_ccch_load(struct msgb *msg) return 0; } +/* CCCH overloaded, IMM_ASSIGN was dropped */ +static int rsl_rx_delete_ind(struct gsm_bts_trx *trx, struct msgb *msg) +{ + struct abis_rsl_dchan_hdr *rqd_hdr = msgb_l2(msg); + struct gsm48_imm_ass *ia; + struct gsm_lchan *lchan; + struct gsm_bts_trx *cur_trx; + uint8_t chan_nr; + uint16_t arfcn; + + /* bts didn't send IMM_ASSIGN, so we should release allocated channel */ + if (msgb_l2len(msg) != MACBLOCK_SIZE + 6) + return -EIO; + + ia = (struct gsm48_imm_ass *) (rqd_hdr->data + 2); + + if (ia->msg_type == GSM48_MT_RR_IMM_ASS) { + chan_nr = ia->chan_desc.chan_nr; + arfcn = ia->chan_desc.h0.arfcn_high; + arfcn = (arfcn << 8) | ia->chan_desc.h0.arfcn_low; + llist_for_each_entry(cur_trx, &trx->bts->trx_list, list) { + if (cur_trx->arfcn == arfcn) { + lchan = lchan_lookup(cur_trx, chan_nr); + if (!lchan) + return -EINVAL; + if (lchan->state != LCHAN_S_ACTIVE) + return -EINVAL; + rsl_direct_rf_release(lchan); + } + } + } + + return 0; +} + static int abis_rsl_rx_cchan(struct msgb *msg) { struct e1inp_sign_link *sign_link = msg->dst; @@ -1558,6 +1593,8 @@ static int abis_rsl_rx_cchan(struct msgb *msg) break; case RSL_MT_DELETE_IND: /* CCCH overloaded, IMM_ASSIGN was dropped */ + rc = rsl_rx_delete_ind(sign_link->trx, msg); + break; case RSL_MT_CBCH_LOAD_IND: /* current load on the CBCH */ LOGP(DRSL, LOGL_NOTICE, "Unimplemented Abis RSL TRX message " -- 1.7.9.5

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OsmoDevCon participation
by Ciaby 18 Feb '14

18 Feb '14

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hi everybody, I know that's a bit late, but... I'm part of the Rhizomatica project, we're currently building a GSM/SIP hybrid network in Mexico. I'll be around Europe at the time of the conference, and I was wondering if there is still space available to attend. I'm not a developer of Osmocom, but we're patching OpenBSC here and there to make it fit our platform. I could come and present what is the current status, the code we wrote to manage the network from a user perspective, and where we're going in the near future. Could that be of any interest to the Osmocom crew? Cheers Ciaby -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF4EAREKAAYFAlMCef8ACgkQC30ZhxNccpHkggD+M4Sn1Zakc+1oDilvm0dkfY3P 2LidV/BIiTM7P/rgXmEA/29U6I+BhvqIyFcj0ICdZkJoB66aYc70Zk5VOhtv/92f =tvJk -----END PGP SIGNATURE-----

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Docker container for OpenBSC in NITB mode
by Alexey Shamrin 18 Feb '14

18 Feb '14

Hi all, I've recently played with Docker [1] and OpenBSC (osmo-nitb). The result is osmonitb-docker: https://github.com/shamrin/osmonitb-docker What you can do with it? You can use it to hack on OpenBSC under Mac or even Windows (there's Vagrant+VirtualBox config). Or you can try to streamline deployment and testing on production hardware. I've tested it under Mac working together with Fairwaves UmSITE hardware (running OsmoBTS). SMS and phone calls all work. Does it make sense to submit osmonitb-docker as a patch to OpenBSC? Quick start, under real or virtual Ubuntu 12.04, with Docker installed: git clone https://github.com/shamrin/osmonitb-docker.git cd osmonitb-docker docker build -rm -t shamrin/osmonitb . docker run -v $HOME/db:/var/db -i -t -p 3002:3002 -p 3003:3003 -p 30000:30000/udp -p 30001:30001/udp -p 30002:30002/udp -p 30003:30003/udp -p 30004:30004/udp -p 30005:30005/udp -p 30006:30006/udp shamrin/osmonitb start-nitb -i 10.0.0.10 GSM1800 10 20 (replace last 4 arguments as necessary) [1]: https://www.docker.io/ Alexey

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[PATCH] rsl/si: Fix resetting bits in bts->si_valid
by Jacob Erlbeck 15 Feb '14

15 Feb '14

Use 'var &= ~(1 << x)' to reset bits instead of 'var &= (1 << x)'. Sponsored-by: On-Waves ehf --- src/common/rsl.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/common/rsl.c b/src/common/rsl.c index 8b7702b..b7dc2b5 100644 --- a/src/common/rsl.c +++ b/src/common/rsl.c @@ -331,7 +331,7 @@ static int rsl_rx_bcch_info(struct gsm_bts_trx *trx, struct msgb *msg) LOGP(DRSL, LOGL_INFO, " Rx RSL BCCH INFO (SI%s)\n", get_value_string(osmo_sitype_strs, osmo_si)); } else { - bts->si_valid &= (1 << osmo_si); + bts->si_valid &= ~(1 << osmo_si); LOGP(DRSL, LOGL_INFO, " RX RSL Disabling BCCH INFO (SI%s)\n", get_value_string(osmo_sitype_strs, osmo_si)); } @@ -445,7 +445,7 @@ static int rsl_rx_sacch_fill(struct gsm_bts_trx *trx, struct msgb *msg) LOGP(DRSL, LOGL_INFO, " Rx RSL SACCH FILLING (SI%s)\n", get_value_string(osmo_sitype_strs, osmo_si)); } else { - bts->si_valid &= (1 << osmo_si); + bts->si_valid &= ~(1 << osmo_si); LOGP(DRSL, LOGL_INFO, " Rx RSL Disabling SACCH FILLING (SI%s)\n", get_value_string(osmo_sitype_strs, osmo_si)); } -- 1.7.9.5

2 2

Unbounded AGCH queue in OsmoBTS
by Alexander Chemeris 13 Feb '14

13 Feb '14

Hi all, We're moving this discussion to the mailing list, as it seems it is more generic and complex than we've thought initially. The issue arose when I started doing load testing of the OsmoTRX transceiver and disabled all gating in it. As a result, all incoming noise was processed as valid Normal Bursts and Access Bursts and sent up to OsmoBTS. This leads to a situation, similar to a RACH flood, when there are more RACH requests coming, than a BTS could reasonably process. And this leads to an unbounded increase of the AGCH queue in the BTS - it consumes a few Mb per minute. I think that this is the root cause of the issue we've seen at a Netherlands festival installation, when 20K phones suddenly started connecting to our station after official networks went down. When the amount of RACH requests exceeded available CCCH capacity (took <5 seconds), mobile phones stopped answering out IMM.ASS messages. Hypothesis is that the AGCH queue became so long, requests were sent too late for a phone to receive it. And thus no phones answered to our IMM.ASS messages. Unfortunately, I wasn't able to collect enough data to check this hypothesis during that time and we don't have another big festival on hands atm. An attached is a quick fix for the unbounded queue growth. It uses a hardcoded value for the maximum queue length, which is fine for our load testing, but not flexible enough for the real life usage. We should make the AGCH queue long enough to keep high performance. At the same time, it must not exceed MS timeout or _all_ IMM.ASS messages will miss their target MS's. We could make this parameter user-configurable on a BTS side, but it seems more reasonable to automatically calculate it, depending on the channel combination and timeout values. But this should be done on the BSC side. So the questions are: 1) what is a good way to calculate it? 2) should we configure this queue length over OML, or move the queue from BTS to BSC? -- Regards, Alexander Chemeris. CEO, Fairwaves LLC / ООО УмРадио http://fairwaves.ru

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OpenBSC February 2014