From: Roy Marples <roy@marples.name>
Date: Wed, 5 Apr 2017 15:31:16 +0000 (+0100)
Subject: if-bsd: support ROUTE_MSGFILTER socket option
X-Git-Tag: v7.0.0-beta3~41
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ca6b99c30b71d49e5f3b3d8dafee83021bad178c;p=thirdparty%2Fdhcpcd.git

if-bsd: support ROUTE_MSGFILTER socket option

This reduces needless context switching just to discard route(4)
message types we're not interested in.
---

diff --git a/src/if-bsd.c b/src/if-bsd.c
index 504811db..eeb5a4b4 100644
--- a/src/if-bsd.c
+++ b/src/if-bsd.c
@@ -120,6 +120,9 @@ int
 if_opensockets_os(struct dhcpcd_ctx *ctx)
 {
 	struct priv *priv;
+#ifdef ROUTE_MSGFILTER
+	unsigned int msgfilter;
+#endif
 
 	if ((priv = malloc(sizeof(*priv))) == NULL)
 		return -1;
@@ -137,6 +140,25 @@ if_opensockets_os(struct dhcpcd_ctx *ctx)
 #define SOCK_FLAGS	(SOCK_CLOEXEC | SOCK_NONBLOCK)
 	ctx->link_fd = xsocket(PF_ROUTE, SOCK_RAW | SOCK_FLAGS, AF_UNSPEC);
 #undef SOCK_FLAGS
+
+#ifdef ROUTE_MSGFILTER
+	msgfilter = ROUTE_FILTER(RTM_IFINFO)
+#ifdef RTM_IFANNOUNCE
+	    | ROUTE_FILTER(RTM_IFANNOUNCE)
+#endif
+	    | ROUTE_FILTER(RTM_ADD)
+	    | ROUTE_FILTER(RTM_CHANGE)
+	    | ROUTE_FILTER(RTM_DELETE)
+#ifdef RTM_CHGADDR
+	    | ROUTE_FILTER(RTM_CHGADDR)
+#endif
+	    | ROUTE_FILTER(RTM_DELADDR)
+	    | ROUTE_FILTER(RTM_NEWADDR);
+	if (setsockopt(ctx->link_fd, PF_ROUTE, ROUTE_MSGFILTER,
+	    &msgfilter, sizeof(msgfilter)) == -1)
+		syslog(LOG_ERR, "ROUTE_MSGFILTER: %m");
+#endif
+
 	return ctx->link_fd == -1 ? -1 : 0;
 }