From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 25 Aug 2021 11:29:45 +0000 (+0200)
Subject: libnetlink: fix netlink buffer space handling
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=9622264cf92691f18ae9222b0a4c9db95af5d80d;p=project%2Fustp.git

libnetlink: fix netlink buffer space handling

Significantly increaese buffer size in order to avoid missing events
Do not stop polling socket after running out of buffer space

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

diff --git a/libnetlink.c b/libnetlink.c
index 477e1a2..5c5523d 100644
--- a/libnetlink.c
+++ b/libnetlink.c
@@ -27,7 +27,7 @@
 #include "libnetlink.h"
 
 #ifndef DEFAULT_RTNL_BUFSIZE
-#define DEFAULT_RTNL_BUFSIZE	256 * 1024
+#define DEFAULT_RTNL_BUFSIZE	4 * 1024 * 1024
 #endif
 
 #ifndef RTNL_SND_BUFSIZE
@@ -48,6 +48,7 @@ int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
 	socklen_t addr_len;
 	int sndbuf = RTNL_SND_BUFSIZE;
 	int rcvbuf = RTNL_RCV_BUFSIZE;
+	int yes = 1;
 
 	memset(rth, 0, sizeof(*rth));
 
@@ -69,6 +70,9 @@ int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
 		return -1;
 	}
 
+	if (setsockopt(rth->fd, SOL_NETLINK, NETLINK_NO_ENOBUFS, &yes, sizeof(yes)) < 0)
+		ERROR("NETLINK_NO_EBUFS");
+
 	memset(&rth->local, 0, sizeof(rth->local));
 	rth->local.nl_family = AF_NETLINK;
 	rth->local.nl_groups = subscriptions;