<p>laforge <strong>submitted</strong> this change.</p><p><a href="https://gerrit.osmocom.org/c/libosmocore/+/21458">View Change</a></p><div style="white-space:pre-wrap">Approvals:
laforge: Looks good to me, approved
pespin: Looks good to me, but someone else must approve
Jenkins Builder: Verified
</div><pre style="font-family: monospace,monospace; white-space: pre-wrap;">gprs_ns2_fr: Monitor the kernel net-device link state<br><br>We use the newly-introduced libmnl integration of libosmocore in order<br>to receive netlink events from the kernel on link state changes.<br><br>If one of "our" interfaces changed link state, we report this in the log<br>and also store it within the "bind".<br><br>Change-Id: I779556991bfc88b7751b2be17bb81c329cfb9e01<br>---<br>M src/gb/gprs_ns2_fr.c<br>1 file changed, 125 insertions(+), 2 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/src/gb/gprs_ns2_fr.c b/src/gb/gprs_ns2_fr.c</span><br><span>index 47d3a5d..3cf44ef 100644</span><br><span>--- a/src/gb/gprs_ns2_fr.c</span><br><span>+++ b/src/gb/gprs_ns2_fr.c</span><br><span>@@ -50,8 +50,10 @@</span><br><span> #include <osmocom/core/select.h></span><br><span> #include <osmocom/core/socket.h></span><br><span> #include <osmocom/core/talloc.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <osmocom/core/mnl.h></span><br><span> #include <osmocom/gprs/gprs_ns2.h></span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+#include "config.h"</span><br><span> #include "common_vty.h"</span><br><span> #include "gprs_ns2_internal.h"</span><br><span> </span><br><span>@@ -81,6 +83,7 @@</span><br><span> struct osmo_fd fd;</span><br><span> char netif[IF_NAMESIZE];</span><br><span> struct osmo_fr_link *link;</span><br><span style="color: hsl(120, 100%, 40%);">+ bool if_running;</span><br><span> };</span><br><span> </span><br><span> struct priv_vc {</span><br><span>@@ -112,8 +115,8 @@</span><br><span> priv = bind->priv;</span><br><span> fr_link = priv->link;</span><br><span> </span><br><span style="color: hsl(0, 100%, 40%);">- vty_out(vty, "FR bind: %s, role: %s%s", priv->netif,</span><br><span style="color: hsl(0, 100%, 40%);">- osmo_fr_role_str(fr_link->role), VTY_NEWLINE);</span><br><span style="color: hsl(120, 100%, 40%);">+ vty_out(vty, "FR bind: %s, role: %s, link: %s%s", priv->netif,</span><br><span style="color: hsl(120, 100%, 40%);">+ osmo_fr_role_str(fr_link->role), priv->if_running ? "UP" : "DOWN", VTY_NEWLINE);</span><br><span> </span><br><span> llist_for_each_entry(nsvc, &bind->nsvc, blist) {</span><br><span> vty_out(vty, " NSVCI %05u: %s%s", nsvc->nsvci, gprs_ns2_ll_str(nsvc), VTY_NEWLINE);</span><br><span>@@ -334,6 +337,116 @@</span><br><span> return fd;</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+#ifdef ENABLE_LIBMNL</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+#include <osmocom/core/mnl.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <linux/if.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <linux/if_link.h></span><br><span style="color: hsl(120, 100%, 40%);">+#include <linux/rtnetlink.h></span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+#ifndef ARPHRD_FRAD</span><br><span style="color: hsl(120, 100%, 40%);">+#define ARPHRD_FRAD 770</span><br><span style="color: hsl(120, 100%, 40%);">+#endif</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+/* validate the netlink attributes */</span><br><span style="color: hsl(120, 100%, 40%);">+static int data_attr_cb(const struct nlattr *attr, void *data)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct nlattr **tb = data;</span><br><span style="color: hsl(120, 100%, 40%);">+ int type = mnl_attr_get_type(attr);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mnl_attr_type_valid(attr, IFLA_MAX) < 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_OK;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ switch (type) {</span><br><span style="color: hsl(120, 100%, 40%);">+ case IFLA_MTU:</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mnl_attr_validate(attr, MNL_TYPE_U32) < 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_ERROR;</span><br><span style="color: hsl(120, 100%, 40%);">+ break;</span><br><span style="color: hsl(120, 100%, 40%);">+ case IFLA_IFNAME:</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mnl_attr_validate(attr, MNL_TYPE_STRING) < 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_ERROR;</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%);">+ tb[type] = attr;</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_OK;</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%);">+/* find the bind for the netdev (if any) */</span><br><span style="color: hsl(120, 100%, 40%);">+static struct gprs_ns2_vc_bind *bind4netdev(struct gprs_ns2_inst *nsi, const char *ifname)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gprs_ns2_vc_bind *bind;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ llist_for_each_entry(bind, &nsi->binding, list) {</span><br><span style="color: hsl(120, 100%, 40%);">+ struct priv_bind *bpriv = bind->priv;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!strcmp(bpriv->netif, ifname))</span><br><span style="color: hsl(120, 100%, 40%);">+ return bind;</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 NULL;</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%);">+/* handle a single netlink message received via libmnl */</span><br><span style="color: hsl(120, 100%, 40%);">+static int linkmon_mnl_cb(const struct nlmsghdr *nlh, void *data)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ struct osmo_mnl *omnl = data;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gprs_ns2_vc_bind *bind;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct nlattr *tb[IFLA_MAX+1] = {};</span><br><span style="color: hsl(120, 100%, 40%);">+ struct ifinfomsg *ifm = mnl_nlmsg_get_payload(nlh);</span><br><span style="color: hsl(120, 100%, 40%);">+ struct gprs_ns2_inst *nsi;</span><br><span style="color: hsl(120, 100%, 40%);">+ const char *ifname;</span><br><span style="color: hsl(120, 100%, 40%);">+ bool if_running;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(omnl);</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(ifm);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ nsi = omnl->priv;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (ifm->ifi_type != ARPHRD_FRAD)</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_OK;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ mnl_attr_parse(nlh, sizeof(*ifm), data_attr_cb, tb);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!tb[IFLA_IFNAME])</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_OK;</span><br><span style="color: hsl(120, 100%, 40%);">+ ifname = mnl_attr_get_str(tb[IFLA_IFNAME]);</span><br><span style="color: hsl(120, 100%, 40%);">+ if_running = !!(ifm->ifi_flags & IFF_RUNNING);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ bind = bind4netdev(nsi, ifname);</span><br><span style="color: hsl(120, 100%, 40%);">+ if (bind) {</span><br><span style="color: hsl(120, 100%, 40%);">+ struct priv_bind *bpriv = bind->priv;</span><br><span style="color: hsl(120, 100%, 40%);">+ if (bpriv->if_running != if_running) {</span><br><span style="color: hsl(120, 100%, 40%);">+ /* update running state */</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DLNS, LOGL_NOTICE, "FR net-device '%s': Physical link state changed: %s\n",</span><br><span style="color: hsl(120, 100%, 40%);">+ ifname, if_running ? "UP" : "DOWN");</span><br><span style="color: hsl(120, 100%, 40%);">+ bpriv->if_running = if_running;</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%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ return MNL_CB_OK;</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%);">+/* trigger one initial dump of all link information */</span><br><span style="color: hsl(120, 100%, 40%);">+static void linkmon_initial_dump(struct osmo_mnl *omnl)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ char buf[MNL_SOCKET_BUFFER_SIZE];</span><br><span style="color: hsl(120, 100%, 40%);">+ struct nlmsghdr *nlh = mnl_nlmsg_put_header(buf);</span><br><span style="color: hsl(120, 100%, 40%);">+ struct rtgenmsg *rt;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ nlh->nlmsg_type = RTM_GETLINK;</span><br><span style="color: hsl(120, 100%, 40%);">+ nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;</span><br><span style="color: hsl(120, 100%, 40%);">+ nlh->nlmsg_seq = time(NULL);</span><br><span style="color: hsl(120, 100%, 40%);">+ rt = mnl_nlmsg_put_extra_header(nlh, sizeof(struct rtgenmsg));</span><br><span style="color: hsl(120, 100%, 40%);">+ rt->rtgen_family = AF_PACKET;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ if (mnl_socket_sendto(omnl->mnls, nlh, nlh->nlmsg_len) < 0) {</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DLNS, LOGL_ERROR, "linkmon: Cannot send rtnetlink message: %s\n", strerror(errno));</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%);">+ /* the response[s] will be handled just like the events */</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+#endif /* LIBMNL */</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! Create a new bind for NS over FR.</span><br><span> * \param[in] nsi NS instance in which to create the bind</span><br><span> * \param[in] netif Network interface to bind to</span><br><span>@@ -401,6 +514,16 @@</span><br><span> INIT_LLIST_HEAD(&bind->nsvc);</span><br><span> llist_add(&bind->list, &nsi->binding);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+#ifdef ENABLE_LIBMNL</span><br><span style="color: hsl(120, 100%, 40%);">+ if (!nsi->linkmon_mnl)</span><br><span style="color: hsl(120, 100%, 40%);">+ nsi->linkmon_mnl = osmo_mnl_init(nsi, NETLINK_ROUTE, RTMGRP_LINK, linkmon_mnl_cb, nsi);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* we get a new full dump after every bind. which is a bit excessive. But that's just once</span><br><span style="color: hsl(120, 100%, 40%);">+ * at start-up, so we can get away with it */</span><br><span style="color: hsl(120, 100%, 40%);">+ if (nsi->linkmon_mnl)</span><br><span style="color: hsl(120, 100%, 40%);">+ linkmon_initial_dump(nsi->linkmon_mnl);</span><br><span style="color: hsl(120, 100%, 40%);">+#endif</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> return rc;</span><br><span> </span><br><span> err_fd:</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/libosmocore/+/21458">change 21458</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/+/21458"/><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: I779556991bfc88b7751b2be17bb81c329cfb9e01 </div>
<div style="display:none"> Gerrit-Change-Number: 21458 </div>
<div style="display:none"> Gerrit-PatchSet: 6 </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: laforge <laforge@osmocom.org> </div>
<div style="display:none"> Gerrit-Reviewer: pespin <pespin@sysmocom.de> </div>
<div style="display:none"> Gerrit-MessageType: merged </div>