<p>laforge <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/21922">View Change</a></p><div style="white-space:pre-wrap">Approvals:
Jenkins Builder: Verified
laforge: Looks good to me, approved
Objections:
fixeria: I would prefer this is not merged as is
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">sysinfo.c: Fix SI4 GPRS patching which overwrote CBCH IE<br><br>In Change-Id I1fd513ea03297918d15d4b28ed454f9b6dd6ebfa we introduced<br>patching of SI4 to indicate GPRS presence in terms of PCU connection<br>status. Unfortauntely this didn't account for optional IEs being<br>present in SI4, and hence overwrote any CBCH related information<br>elements, if present.<br><br>This in turn meant that since the above-mentioned commit, you could<br>have either a GPRS-capable, network, or a Cell Broadcast capable one.<br><br>Change-Id: I0ee0cf736e2fb74a6759a68101f699b4ec2ef54e<br>Related: OS#3075<br>---<br>M include/osmo-bts/bts.h<br>M src/common/rsl.c<br>M src/common/sysinfo.c<br>3 files changed, 43 insertions(+), 9 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmo-bts/bts.h b/include/osmo-bts/bts.h</span><br><span>index 2edc20e..6d8b570 100644</span><br><span>--- a/include/osmo-bts/bts.h</span><br><span>+++ b/include/osmo-bts/bts.h</span><br><span>@@ -377,6 +377,7 @@</span><br><span> uint8_t *bts_sysinfo_get(struct gsm_bts *bts, const struct gsm_time *g_time);</span><br><span> void regenerate_si3_restoctets(struct gsm_bts *bts);</span><br><span> void regenerate_si4_restoctets(struct gsm_bts *bts);</span><br><span style="color: hsl(120, 100%, 40%);">+int get_si4_ro_offset(const uint8_t *si4_buf);</span><br><span> uint8_t *lchan_sacch_get(struct gsm_lchan *lchan);</span><br><span> int lchan_init_lapdm(struct gsm_lchan *lchan);</span><br><span> </span><br><span>diff --git a/src/common/rsl.c b/src/common/rsl.c</span><br><span>index ef23039..8e27e77 100644</span><br><span>--- a/src/common/rsl.c</span><br><span>+++ b/src/common/rsl.c</span><br><span>@@ -380,13 +380,16 @@</span><br><span> regenerate_si3_restoctets(bts);</span><br><span> } else if (SYSINFO_TYPE_4 == osmo_si) {</span><br><span> /* decode original SI4 Rest Octets as sent by BSC */</span><br><span style="color: hsl(0, 100%, 40%);">- const uint8_t *si4_ro_buf = (uint8_t *) GSM_BTS_SI(bts, osmo_si);</span><br><span style="color: hsl(0, 100%, 40%);">- si4_ro_buf += offsetof(struct gsm48_system_information_type_4, data);</span><br><span style="color: hsl(0, 100%, 40%);">- osmo_gsm48_rest_octets_si4_decode(&bts->si4_ro_decoded, si4_ro_buf,</span><br><span style="color: hsl(0, 100%, 40%);">- GSM_MACBLOCK_LEN - offsetof(struct gsm48_system_information_type_4, data));</span><br><span style="color: hsl(0, 100%, 40%);">- /* patch out GPRS indicator from binary if PCU is not connected; will be enabled</span><br><span style="color: hsl(0, 100%, 40%);">- * after PCU connects */</span><br><span style="color: hsl(0, 100%, 40%);">- regenerate_si4_restoctets(bts);</span><br><span style="color: hsl(120, 100%, 40%);">+ const uint8_t *si4 = (uint8_t *) GSM_BTS_SI(bts, osmo_si);</span><br><span style="color: hsl(120, 100%, 40%);">+ int si4_ro_offset = get_si4_ro_offset(si4);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (si4_ro_offset < GSM_MACBLOCK_LEN) {</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_gsm48_rest_octets_si4_decode(&bts->si4_ro_decoded,</span><br><span style="color: hsl(120, 100%, 40%);">+ si4 + si4_ro_offset,</span><br><span style="color: hsl(120, 100%, 40%);">+ GSM_MACBLOCK_LEN - si4_ro_offset);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* patch out GPRS indicator from binary if PCU is not connected; will be</span><br><span style="color: hsl(120, 100%, 40%);">+ * enabled after PCU connects */</span><br><span style="color: hsl(120, 100%, 40%);">+ regenerate_si4_restoctets(bts);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> }</span><br><span> </span><br><span> if (SYSINFO_TYPE_13 == osmo_si)</span><br><span>diff --git a/src/common/sysinfo.c b/src/common/sysinfo.c</span><br><span>index f3deb0d..9eea539 100644</span><br><span>--- a/src/common/sysinfo.c</span><br><span>+++ b/src/common/sysinfo.c</span><br><span>@@ -1,4 +1,4 @@</span><br><span style="color: hsl(0, 100%, 40%);">-/* (C) 2011-2019 by Harald Welte <laforge@gnumonks.org></span><br><span style="color: hsl(120, 100%, 40%);">+/* (C) 2011-2020 by Harald Welte <laforge@gnumonks.org></span><br><span> *</span><br><span> * All Rights Reserved</span><br><span> *</span><br><span>@@ -18,6 +18,7 @@</span><br><span> */</span><br><span> </span><br><span> #include <stdint.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <errno.h></span><br><span> </span><br><span> #include <osmocom/gsm/gsm_utils.h></span><br><span> #include <osmocom/gsm/sysinfo.h></span><br><span>@@ -212,11 +213,34 @@</span><br><span> osmo_gsm48_rest_octets_si3_encode(si3_buf + si3_size, &si3ro_tmp);</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/* get the offset of the SI4 rest octets */</span><br><span style="color: hsl(120, 100%, 40%);">+int get_si4_ro_offset(const uint8_t *si4_buf)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct gsm48_system_information_type_4 *si4 =</span><br><span style="color: hsl(120, 100%, 40%);">+ (const struct gsm48_system_information_type_4 *) si4_buf;</span><br><span style="color: hsl(120, 100%, 40%);">+ int si4_size;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* start with the length of the mandatory part */</span><br><span style="color: hsl(120, 100%, 40%);">+ si4_size = offsetof(struct gsm48_system_information_type_4, data);</span><br><span style="color: hsl(120, 100%, 40%);">+ /* then add optional parts, if any */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (si4->data[0] == GSM48_IE_CBCH_CHAN_DESC) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* fixed 4-byte TV IE, see Table 9.1.36.1 of TS 44.018 */</span><br><span style="color: hsl(120, 100%, 40%);">+ si4_size += 4;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (si4->data[4] == GSM48_IE_CBCH_MOB_AL)</span><br><span style="color: hsl(120, 100%, 40%);">+ si4_size += TLV_GROSS_LEN(si4->data[5]);</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (si4_size >= GSM_MACBLOCK_LEN)</span><br><span style="color: hsl(120, 100%, 40%);">+ return -EINVAL;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return si4_size;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* re-generate SI4 restoctets with GPRS indicator depending on the PCU socket connection state */</span><br><span> void regenerate_si4_restoctets(struct gsm_bts *bts)</span><br><span> {</span><br><span> uint8_t *si4_buf = GSM_BTS_SI(bts, SYSINFO_TYPE_4);</span><br><span style="color: hsl(0, 100%, 40%);">- size_t si4_size = offsetof(struct gsm48_system_information_type_4, data);</span><br><span style="color: hsl(120, 100%, 40%);">+ size_t si4_size;</span><br><span> struct osmo_gsm48_si_ro_info si4ro_tmp;</span><br><span> </span><br><span> /* If BSC has never set SI4, there's nothing to patch */</span><br><span>@@ -227,6 +251,12 @@</span><br><span> if (!bts->si4_ro_decoded.gprs_ind.present)</span><br><span> return;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ si4_size = get_si4_ro_offset(si4_buf);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (si4_size < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DPCU, LOGL_ERROR, "Cannot parse SI4, hence not patching GPRS indicator\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ return;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Create a temporary copy and patch that, if no PCU is around */</span><br><span> si4ro_tmp = bts->si4_ro_decoded;</span><br><span> if (!pcu_connected()) {</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/21922">change 21922</a>. 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<div style="display:none"> Gerrit-Project: osmo-bts </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I0ee0cf736e2fb74a6759a68101f699b4ec2ef54e </div>
<div style="display:none"> Gerrit-Change-Number: 21922 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: Jenkins Builder </div>
<div style="display:none"> Gerrit-Reviewer: daniel <dwillmann@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: fixeria <vyanitskiy@sysmocom.de> </div>
<div style="display:none"> Gerrit-Reviewer: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>