From a75819461ec7c7d8468498362f9104637ff7c9e9 Mon Sep 17 00:00:00 2001
From: Rozhuk Ivan <rozhuk.im@gmail.com>
Date: Wed, 23 Jun 2021 10:20:10 -0600
Subject: [PATCH] devctl: add ADDR_ADD and ADDR_DEL devctl event for IFNET

Add devd event on network iface address add/remove.  Can be used to
automate actions on any address change.

Reviewed by:		imp@ (and minor style tweaks)
Sponsored by:		Netflix
Differential Revision:	https://reviews.freebsd.org/D30840
---
 sbin/devd/devd.conf.5 |  4 ++++
 sys/net/route.c       | 29 +++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/sbin/devd/devd.conf.5 b/sbin/devd/devd.conf.5
index 56e2df684f32..f6579ac3f20f 100644
--- a/sbin/devd/devd.conf.5
+++ b/sbin/devd/devd.conf.5
@@ -469,6 +469,10 @@ The network interface is attached to the system.
 The network interface is detached from the system.
 .It Li IFNET Ta Em inet Ta Li RENAME Ta
 The network interface is renamed.
+.It Li IFNET Ta Em inet Ta Li ADDR_ADD Ta
+The network interface address added.
+.It Li IFNET Ta Em inet Ta Li ADDR_DEL Ta
+The network interface address removed.
 .El
 .Pp
 .Bl -column "System" "Subsystem" "1234567" -compact
diff --git a/sys/net/route.c b/sys/net/route.c
index 2416aa9a983f..4f7eb6f64210 100644
--- a/sys/net/route.c
+++ b/sys/net/route.c
@@ -50,6 +50,7 @@
 #include <sys/syslog.h>
 #include <sys/sysproto.h>
 #include <sys/proc.h>
+#include <sys/devctl.h>
 #include <sys/domain.h>
 #include <sys/eventhandler.h>
 #include <sys/kernel.h>
@@ -67,6 +68,7 @@
 
 #include <netinet/in.h>
 #include <netinet/ip_mroute.h>
+#include <netinet6/in6_var.h>
 
 VNET_PCPUSTAT_DEFINE(struct rtstat, rtstat);
 
@@ -685,6 +687,10 @@ rt_maskedcopy(struct sockaddr *src, struct sockaddr *dst, struct sockaddr *netma
 int
 rt_addrmsg(int cmd, struct ifaddr *ifa, int fibnum)
 {
+#if defined(INET) || defined(INET6)
+	struct sockaddr *sa = ifa->ifa_addr;
+	struct ifnet *ifp = ifa->ifa_ifp;
+#endif
 
 	KASSERT(cmd == RTM_ADD || cmd == RTM_DELETE,
 	    ("unexpected cmd %d", cmd));
@@ -693,6 +699,29 @@ rt_addrmsg(int cmd, struct ifaddr *ifa, int fibnum)
 
 	EVENTHANDLER_DIRECT_INVOKE(rt_addrmsg, ifa, cmd);
 
+#ifdef INET
+	if (sa->sa_family == AF_INET) {
+		char addrstr[INET_ADDRSTRLEN];
+		char strbuf[INET_ADDRSTRLEN + 12];
+
+		inet_ntoa_r(((struct sockaddr_in *)sa)->sin_addr, addrstr);
+		snprintf(strbuf, sizeof(strbuf), "address=%s", addrstr);
+		devctl_notify("IFNET", ifp->if_xname,
+		    (cmd == RTM_ADD) ? "ADDR_ADD" : "ADDR_DEL", strbuf);
+	}
+#endif
+#ifdef INET6
+	if (sa->sa_family == AF_INET6) {
+		char addrstr[INET6_ADDRSTRLEN];
+		char strbuf[INET6_ADDRSTRLEN + 12];
+
+		ip6_sprintf(addrstr, IFA_IN6(ifa));
+		snprintf(strbuf, sizeof(strbuf), "address=%s", addrstr);
+		devctl_notify("IFNET", ifp->if_xname,
+		    (cmd == RTM_ADD) ? "ADDR_ADD" : "ADDR_DEL", strbuf);
+	}
+#endif
+
 	if (V_rt_add_addr_allfibs)
 		fibnum = RT_ALL_FIBS;
 	return (rtsock_addrmsg(cmd, ifa, fibnum));