From: Eric Dumazet <edumazet@google.com>
Date: Fri, 29 May 2015 12:37:49 +0000 (-0700)
Subject: ss: do not bindly dump two families
X-Git-Tag: v4.1.0~8
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=518af1e0b14cdc8eeac4db313767f5d1dfd1fce1;p=thirdparty%2Fiproute2.git

ss: do not bindly dump two families

ss currently dumps IPv4 sockets, then IPv6 sockets from the kernel,
even if -4 or -6 option was given. Filtering in user space then has to
drop all sockets of wrong family. Such a waste of time...

Before :

$ time ss -tn -4 | wc -l
251659

real	0m1.241s
user	0m0.423s
sys	0m0.806s

After:

$ time ss -tn -4 | wc -l
251672

real	0m0.779s
user	0m0.412s
sys	0m0.386s

Signed-off-by: Eric Dumazet <edumazet@google.com>
---

diff --git a/misc/ss.c b/misc/ss.c
index 68bffe289..1f4a30f7b 100644
--- a/misc/ss.c
+++ b/misc/ss.c
@@ -2199,6 +2199,8 @@ static int inet_show_netlink(struct filter *f, FILE *dump_fp, int protocol)
 		return -1;
 	rth.dump = MAGIC_SEQ;
 	rth.dump_fp = dump_fp;
+	if (preferred_family == PF_INET6)
+		family = PF_INET6;
 
 again:
 	if ((err = sockdiag_send(family, rth.fd, protocol, f)))
@@ -2211,7 +2213,7 @@ again:
 		}
 		goto Exit;
 	}
-	if (family == PF_INET) {
+	if (family == PF_INET && preferred_family != PF_INET) {
 		family = PF_INET6;
 		goto again;
 	}