<p>neels has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bsc/+/18766">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">MSC pooling: implement NAS node selection by NRI from TMSI<br><br>If applicable, choose MSC from NRI, extracted from TMSI MI.<br><br>Change-Id: Ifbdea197b26e88751a391c8a80c41f04e7d5e047<br>---<br>M src/osmo-bsc/gsm_08_08.c<br>1 file changed, 43 insertions(+), 4 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/66/18766/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/osmo-bsc/gsm_08_08.c b/src/osmo-bsc/gsm_08_08.c</span><br><span>index a5f7493..0707c65 100644</span><br><span>--- a/src/osmo-bsc/gsm_08_08.c</span><br><span>+++ b/src/osmo-bsc/gsm_08_08.c</span><br><span>@@ -33,6 +33,7 @@</span><br><span> #include <osmocom/gsm/gsm0808.h></span><br><span> #include <osmocom/gsm/mncc.h></span><br><span> #include <osmocom/gsm/gsm48.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <osmocom/gsm/gsm23236.h></span><br><span> </span><br><span> #include <osmocom/bsc/osmo_bsc_sigtran.h></span><br><span> </span><br><span>@@ -152,6 +153,8 @@</span><br><span> uint8_t round_robin_next_nr;</span><br><span> struct bsc_subscr *subscr;</span><br><span> bool is_emerg = false;</span><br><span style="color: hsl(120, 100%, 40%);">+ int16_t nri_v = -1;</span><br><span style="color: hsl(120, 100%, 40%);">+ bool is_null_nri = false;</span><br><span> </span><br><span> if (msgb_l3len(msg) < sizeof(*gh)) {</span><br><span> LOGP(DRSL, LOGL_ERROR, "There is no GSM48 header here.\n");</span><br><span>@@ -186,16 +189,45 @@</span><br><span> }</span><br><span> }</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* TODO: extract NRI from MI */</span><br><span style="color: hsl(120, 100%, 40%);">+#define LOG_NRI(LOGLEVEL, FORMAT, ARGS...) \</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DMSC, LOGLEVEL, "%s NRI(%d)=0x%x=%d: " FORMAT, osmo_mobile_identity_to_str_c(OTC_SELECT, &mi), \</span><br><span style="color: hsl(120, 100%, 40%);">+ net->nri_bitlen, nri_v, nri_v, ##ARGS)</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Extract NRI bits from TMSI, possibly indicating which MSC is responsible */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mi.type == GSM_MI_TYPE_TMSI) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (osmo_tmsi_nri_v_get(&nri_v, mi.tmsi, net->nri_bitlen)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DMSC, LOGL_ERROR, "Unable to retrieve NRI from TMSI, nri_bitlen == %u\n", net->nri_bitlen);</span><br><span style="color: hsl(120, 100%, 40%);">+ nri_v = -1;</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ is_null_nri = osmo_nri_v_matches_ranges(nri_v, net->null_nri_ranges);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (is_null_nri)</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_NRI(LOGL_DEBUG, "this is a NULL-NRI\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span> /* Iterate MSCs to find one that matches the extracted NRI, and the next round-robin target for the case no NRI</span><br><span> * match is found. */</span><br><span> round_robin_next_nr = (is_emerg ? net->mscs_round_robin_next_emerg_nr : net->mscs_round_robin_next_nr);</span><br><span> llist_for_each_entry(msc, &net->mscs, entry) {</span><br><span style="color: hsl(0, 100%, 40%);">- if (!is_msc_usable(msc, is_emerg))</span><br><span style="color: hsl(0, 100%, 40%);">- continue;</span><br><span style="color: hsl(120, 100%, 40%);">+ bool nri_matches_msc = (nri_v >= 0 && osmo_nri_v_matches_ranges(nri_v, msc->nri_ranges));</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- /* TODO: return msc when extracted NRI matches this MSC */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!is_msc_usable(msc, is_emerg)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (nri_matches_msc)</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_NRI(LOGL_DEBUG, "matches msc %d, but this MSC is currently not connected\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ msc->nr);</span><br><span style="color: hsl(120, 100%, 40%);">+ continue;</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%);">+ /* Return MSC if it matches this NRI, with some debug logging. */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (nri_matches_msc) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (is_null_nri) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_NRI(LOGL_DEBUG, "matches msc %d, but this NRI is also configured as NULL-NRI\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ msc->nr);</span><br><span style="color: hsl(120, 100%, 40%);">+ } else {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_NRI(LOGL_DEBUG, "matches msc %d\n", msc->nr);</span><br><span style="color: hsl(120, 100%, 40%);">+ return msc;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span> </span><br><span> /* Figure out the next round-robin MSC. The MSCs may appear unsorted in net->mscs. Make sure to linearly</span><br><span> * round robin the MSCs by number: pick the lowest msc->nr >= round_robin_next_nr, and also remember the</span><br><span>@@ -207,6 +239,9 @@</span><br><span> msc_round_robin_next = msc;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ if (nri_v >= 0 && !is_null_nri)</span><br><span style="color: hsl(120, 100%, 40%);">+ LOG_NRI(LOGL_DEBUG, "No MSC found for this NRI, doing round-robin\n");</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* No dedicated MSC found. Choose by round-robin.</span><br><span> * If msc_round_robin_next is NULL, there are either no more MSCs at/after mscs_round_robin_next_nr, or none of</span><br><span> * them are usable -- wrap to the start. */</span><br><span>@@ -217,12 +252,16 @@</span><br><span> return NULL;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DMSC, LOGL_DEBUG, "New subscriber %s: MSC round-robin selects msc %d\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_mobile_identity_to_str_c(OTC_SELECT, &mi), msc_target->nr);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* An MSC was picked by round-robin, so update the next round-robin nr to pick */</span><br><span> if (is_emerg)</span><br><span> net->mscs_round_robin_next_emerg_nr = msc_target->nr + 1;</span><br><span> else</span><br><span> net->mscs_round_robin_next_nr = msc_target->nr + 1;</span><br><span> return msc_target;</span><br><span style="color: hsl(120, 100%, 40%);">+#undef LOG_NRI</span><br><span> }</span><br><span> </span><br><span> static int handle_page_resp(struct gsm_subscriber_connection *conn, struct msgb *msg)</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bsc/+/18766">change 18766</a>. 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<div style="display:none"> Gerrit-Project: osmo-bsc </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: Ifbdea197b26e88751a391c8a80c41f04e7d5e047 </div>
<div style="display:none"> Gerrit-Change-Number: 18766 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: neels <nhofmeyr@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>