From: Vincent Bernat <vincent@bernat.im>
Date: Sat, 14 Jan 2017 10:51:58 +0000 (+0100)
Subject: netlink: by default, don't change netlink buffer size
X-Git-Tag: 0.9.6~3^2~1
X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Flldpd.git;a=commitdiff_plain;h=48292d82efbdb3236b540f876df55ae779a3511d

netlink: by default, don't change netlink buffer size

We can't really guess what the current maximum is. On my system, the
default max is quite low (~200k). We don't want everybody to get a
warning. Also, only warn people if we got a smaller size that we
requested.
---

diff --git a/configure.ac b/configure.ac
index b871f94b..2e81f5b5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -348,8 +348,8 @@ lldp_ARG_WITH([lldpd-ctl-socket], [Path to socket for communication with lldpd],
 lldp_ARG_WITH([lldpd-pid-file], [Path to lldpd PID file], [${runstatedir}/lldpd.pid])
 
 # Netlink
-lldp_ARG_WITH_UNQUOTED([netlink-max-receive-bufsize], [Netlink maximum receive buffer size], [4*1024*1024])
-lldp_ARG_WITH_UNQUOTED([netlink-receive-bufsize], [Netlink initial receive buffer size], [256*1024])
+lldp_ARG_WITH_UNQUOTED([netlink-max-receive-bufsize], [Netlink maximum receive buffer size], [1024*1024])
+lldp_ARG_WITH_UNQUOTED([netlink-receive-bufsize], [Netlink initial receive buffer size], [0])
 lldp_ARG_WITH_UNQUOTED([netlink-send-bufsize], [Netlink send buffer size], [0])
 
 # CDP/FDP/EDP/SONMP
diff --git a/src/daemon/netlink.c b/src/daemon/netlink.c
index 7d7814e6..ba726a4d 100644
--- a/src/daemon/netlink.c
+++ b/src/daemon/netlink.c
@@ -67,7 +67,7 @@ netlink_socket_set_buffer_sizes(int s, int sndbuf, int rcvbuf)
 		if (getsockopt(s, SOL_SOCKET, SO_SNDBUF, &got, &size) < 0) {
 			log_warn("netlink", "unable to get SO_SNDBUF");
 		} else {
-			if (got != sndbuf)
+			if (got < sndbuf)
 				log_warnx("netlink", "tried to set SO_SNDBUF to '%d' "
 				    "but got '%d'", sndbuf, got);
 		}
@@ -77,7 +77,7 @@ netlink_socket_set_buffer_sizes(int s, int sndbuf, int rcvbuf)
 		if (getsockopt(s, SOL_SOCKET, SO_RCVBUF, &got, &size) < 0) {
 			log_warn("netlink", "unable to get SO_RCVBUF");
 		} else {
-			if (got != rcvbuf)
+			if (got < rcvbuf)
 				log_warnx("netlink", "tried to set SO_RCVBUF to '%d' "
 				    "but got '%d'", rcvbuf, got);
 		}
@@ -113,8 +113,8 @@ netlink_socket_double_buffer_sizes(int s, int max)
 			log_warn("netlink", "unable to get SO_RCVBUF");
 			return -1;
 		}
-		if (got != current) {
-			log_warn("netlink", "tried to set SO_RCVBUF to '%d' "
+		if (got < current) {
+			log_warnx("netlink", "tried to set SO_RCVBUF to '%d' "
 			    "but got '%d'", current, got);
 			return 1; /* Assume we got the maximum */
 		}