<p>lynxis lazus has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/22343">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">gprs_ns2: inform the NS user (BSSGP) about the MTU of a NSE<br><br>The BSSGP need to know the MTU of the BSSGP layer.<br>The MTU can be 0 if the NSE doesn't contain any NSVC.<br>Every status indication will contain the mtu value.<br>The MTU in the status indication contain the maximum transfer<br>unit of a BSSGP message. From NS side the maximum SDU.<br><br>Change-Id: I5016b295db6185ec131d83089cf6c806e34ef1b6<br>---<br>M include/osmocom/gprs/gprs_ns2.h<br>M src/gb/gprs_ns2.c<br>M src/gb/gprs_ns2_fr.c<br>M src/gb/gprs_ns2_frgre.c<br>M src/gb/gprs_ns2_internal.h<br>M src/gb/gprs_ns2_udp.c<br>6 files changed, 65 insertions(+), 0 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/43/22343/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmocom/gprs/gprs_ns2.h b/include/osmocom/gprs/gprs_ns2.h</span><br><span>index 1b20298..cf2f86c 100644</span><br><span>--- a/include/osmocom/gprs/gprs_ns2.h</span><br><span>+++ b/include/osmocom/gprs/gprs_ns2.h</span><br><span>@@ -135,6 +135,8 @@</span><br><span> /* Only true on the first time it's available.</span><br><span> * Allow the BSSGP layer to reset persistent NSE */</span><br><span> bool first;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* MTU of a BSSGP PDU. It's the lowest MTU of all (alive & dead) NSVCs */</span><br><span style="color: hsl(120, 100%, 40%);">+ int mtu;</span><br><span> } status;</span><br><span> } u;</span><br><span> };</span><br><span>diff --git a/src/gb/gprs_ns2.c b/src/gb/gprs_ns2.c</span><br><span>index 0c1d564..87cb0ad 100644</span><br><span>--- a/src/gb/gprs_ns2.c</span><br><span>+++ b/src/gb/gprs_ns2.c</span><br><span>@@ -474,6 +474,7 @@</span><br><span> nsp.u.status.transfer = ns2_count_transfer_cap(nse, bvci);</span><br><span> nsp.u.status.first = nse->first;</span><br><span> nsp.u.status.persistent = nse->persistent;</span><br><span style="color: hsl(120, 100%, 40%);">+ nsp.u.status.mtu = nse->mtu - 4; /* 1b NS PDU type, 1b NS SDU control, 2b BVCI */</span><br><span> if (nsvc)</span><br><span> nsp.u.status.nsvc = gprs_ns2_ll_str_buf(nsvc_str, sizeof(nsvc_str), nsvc);</span><br><span> </span><br><span>@@ -519,6 +520,7 @@</span><br><span> </span><br><span> llist_add(&nsvc->list, &nse->nsvc);</span><br><span> llist_add(&nsvc->blist, &bind->nsvc);</span><br><span style="color: hsl(120, 100%, 40%);">+ ns2_nse_update_mtu(nse);</span><br><span> </span><br><span> return nsvc;</span><br><span> </span><br><span>@@ -717,6 +719,7 @@</span><br><span> nse->nsei = nsei;</span><br><span> nse->nsi = nsi;</span><br><span> nse->first = true;</span><br><span style="color: hsl(120, 100%, 40%);">+ nse->mtu = 0;</span><br><span> llist_add(&nse->list, &nsi->nse);</span><br><span> INIT_LLIST_HEAD(&nse->nsvc);</span><br><span> </span><br><span>@@ -1316,6 +1319,26 @@</span><br><span> array[i] = bind;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+void ns2_nse_update_mtu(struct gprs_ns2_nse *nse)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gprs_ns2_vc *nsvc;</span><br><span style="color: hsl(120, 100%, 40%);">+ int mtu = 0;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (llist_empty(&nse->nsvc)) {</span><br><span style="color: hsl(120, 100%, 40%);">+ nse->mtu = 0;</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 style="color: hsl(120, 100%, 40%);">+ llist_for_each_entry(nsvc, &nse->nsvc, list) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mtu == 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ mtu = nsvc->bind->mtu;</span><br><span style="color: hsl(120, 100%, 40%);">+ else if (mtu > nsvc->bind->mtu)</span><br><span style="color: hsl(120, 100%, 40%);">+ mtu = nsvc->bind->mtu;</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%);">+ nse->mtu = mtu;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! calculate the transfer capabilities for a nse</span><br><span> * \param nse the nse to count the transfer capability</span><br><span> * \param bvci a bvci - unused</span><br><span>diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c</span><br><span>index 274ed96..00efd8a 100644</span><br><span>--- a/src/gb/gprs_ns2_fr.c</span><br><span>+++ b/src/gb/gprs_ns2_fr.c</span><br><span>@@ -592,6 +592,9 @@</span><br><span> bind->free_vc = free_vc;</span><br><span> bind->dump_vty = dump_vty;</span><br><span> bind->nsi = nsi;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* 48.016 ยง 6.1.4.2 default maximum information field size of 1600 octets</span><br><span style="color: hsl(120, 100%, 40%);">+ * FR has 2 byte header */</span><br><span style="color: hsl(120, 100%, 40%);">+ bind->mtu = 1600 - 2;</span><br><span> priv = bind->priv = talloc_zero(bind, struct priv_bind);</span><br><span> if (!priv) {</span><br><span> rc = -ENOSPC;</span><br><span>diff --git a/src/gb/gprs_ns2_frgre.c b/src/gb/gprs_ns2_frgre.c</span><br><span>index 2812e12..1529b48 100644</span><br><span>--- a/src/gb/gprs_ns2_frgre.c</span><br><span>+++ b/src/gb/gprs_ns2_frgre.c</span><br><span>@@ -568,6 +568,8 @@</span><br><span> bind->send_vc = frgre_vc_sendmsg;</span><br><span> bind->free_vc = free_vc;</span><br><span> bind->nsi = nsi;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* TODO: update mtu similiar to UDP - GRE header */</span><br><span style="color: hsl(120, 100%, 40%);">+ bind->mtu = 1500;</span><br><span> </span><br><span> priv = bind->priv = talloc_zero(bind, struct priv_bind);</span><br><span> if (!priv) {</span><br><span>diff --git a/src/gb/gprs_ns2_internal.h b/src/gb/gprs_ns2_internal.h</span><br><span>index af8c5f0..42499db 100644</span><br><span>--- a/src/gb/gprs_ns2_internal.h</span><br><span>+++ b/src/gb/gprs_ns2_internal.h</span><br><span>@@ -167,6 +167,9 @@</span><br><span> </span><br><span> /*! sum of all the signalling weight of _active_ NS-VCs */</span><br><span> uint32_t sum_sig_weight;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /*! MTU of a NS PDU. This is the lowest MTU of all NSVCs */</span><br><span style="color: hsl(120, 100%, 40%);">+ int mtu;</span><br><span> };</span><br><span> </span><br><span> /*! Structure representing a single NS-VC */</span><br><span>@@ -232,6 +235,9 @@</span><br><span> /*! transfer capability in mbit */</span><br><span> int transfer_capability;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /*! MTU of a NS PDU on this bind. */</span><br><span style="color: hsl(120, 100%, 40%);">+ int mtu;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! which link-layer are we based on? */</span><br><span> enum gprs_ns2_ll ll;</span><br><span> </span><br><span>@@ -276,6 +282,7 @@</span><br><span> uint16_t bvci,</span><br><span> enum gprs_ns2_affecting_cause cause);</span><br><span> void ns2_nse_notify_alive(struct gprs_ns2_vc *nsvc, bool alive);</span><br><span style="color: hsl(120, 100%, 40%);">+void ns2_nse_update_mtu(struct gprs_ns2_nse *nse);</span><br><span> </span><br><span> /* message */</span><br><span> int gprs_ns2_validate(struct gprs_ns2_vc *nsvc,</span><br><span>diff --git a/src/gb/gprs_ns2_udp.c b/src/gb/gprs_ns2_udp.c</span><br><span>index 8bfa184..c468015 100644</span><br><span>--- a/src/gb/gprs_ns2_udp.c</span><br><span>+++ b/src/gb/gprs_ns2_udp.c</span><br><span>@@ -111,6 +111,32 @@</span><br><span> }</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+#define SIZE_IPV4_HEADER 20</span><br><span style="color: hsl(120, 100%, 40%);">+#define SIZE_IPV6_HEADER 23</span><br><span style="color: hsl(120, 100%, 40%);">+#define SIZE_UDP_HEADER 8</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+static void update_mtu(struct gprs_ns2_vc_bind *bind) {</span><br><span style="color: hsl(120, 100%, 40%);">+ struct priv_bind *priv;</span><br><span style="color: hsl(120, 100%, 40%);">+ /* TODO: replace 1500 (default ethernet mtu) with interface mtu */</span><br><span style="color: hsl(120, 100%, 40%);">+ int mtu = 1500;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(gprs_ns2_is_ip_bind(bind));</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ priv = bind->priv;</span><br><span style="color: hsl(120, 100%, 40%);">+ switch (priv->addr.u.sa.sa_family) {</span><br><span style="color: hsl(120, 100%, 40%);">+ case AF_INET:</span><br><span style="color: hsl(120, 100%, 40%);">+ mtu -= SIZE_IPV4_HEADER + SIZE_UDP_HEADER;</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ case AF_INET6:</span><br><span style="color: hsl(120, 100%, 40%);">+ mtu -= SIZE_IPV6_HEADER + SIZE_UDP_HEADER;</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ default:</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</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%);">+ bind->mtu = mtu;</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> </span><br><span> /*! Find a NS-VC by its remote socket address.</span><br><span> * \param[in] bind in which to search</span><br><span>@@ -382,6 +408,8 @@</span><br><span> dscp, rc, errno);</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ update_mtu(bind);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> llist_add(&bind->list, &nsi->binding);</span><br><span> if (result)</span><br><span> *result = bind;</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/22343">change 22343</a>. To unsubscribe, or for help writing mail filters, visit <a href="https://gerrit.osmocom.org/settings">settings</a>.</p><div itemscope itemtype="http://schema.org/EmailMessage"><div itemscope itemprop="action" itemtype="http://schema.org/ViewAction"><link itemprop="url" href="https://gerrit.osmocom.org/c/libosmocore/+/22343"/><meta itemprop="name" content="View Change"/></div></div>
<div style="display:none"> Gerrit-Project: libosmocore </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: I5016b295db6185ec131d83089cf6c806e34ef1b6 </div>
<div style="display:none"> Gerrit-Change-Number: 22343 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: lynxis lazus <lynxis@fe80.eu> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>