From: Roy Marples <roy@marples.name>
Date: Sun, 4 Nov 2018 13:01:15 +0000 (+0000)
Subject: Linux: Use NETLINK_BROADCAST_ERROR
X-Git-Tag: v7.1.0~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c1e95fbbdc8b2f0b795c7750c7f477223113621b;p=thirdparty%2Fdhcpcd.git

Linux: Use NETLINK_BROADCAST_ERROR

This should allow dhcpcd to detect overflow on netlink, just
like NetBSD and OpenBSD.
---

diff --git a/src/if-linux.c b/src/if-linux.c
index abd4cd52..b5f7983d 100644
--- a/src/if-linux.c
+++ b/src/if-linux.c
@@ -294,6 +294,9 @@ if_opensockets_os(struct dhcpcd_ctx *ctx)
 	struct priv *priv;
 	struct sockaddr_nl snl;
 	socklen_t len;
+#ifdef NETLINK_BROADCAST_ERROR
+	int on = 1;
+#endif
 
 	/* Open the link socket first so it gets pid() for the socket.
 	 * Then open our persistent route socket so we get a unique
@@ -311,6 +314,10 @@ if_opensockets_os(struct dhcpcd_ctx *ctx)
 	ctx->link_fd = _open_link_socket(&snl, NETLINK_ROUTE);
 	if (ctx->link_fd == -1)
 		return -1;
+#ifdef NETLINK_BROADCAST_ERROR
+	setsockopt(ctx->link_fd, SOL_NETLINK, NETLINK_BROADCAST_ERROR,
+	    &on, sizeof(on));
+#endif
 
 	if ((priv = calloc(1, sizeof(*priv))) == NULL)
 		return -1;