From: Stanislav Fomichev <stfomichev@gmail.com>
Date: Tue, 27 May 2025 21:55:06 +0000 (-0700)
Subject: ip: support setting multiple features
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=98c04e53cb3e44feb2c4f2543e02801819d825fb;p=thirdparty%2Fiproute2.git

ip: support setting multiple features

Commit a043bea75002 ("ip route: add support for TCP usec TS") added
support for tcp_usec_ts but the existing code was not adjusted
to handle multiple features in the same invocation:

$ ip route add .. dev .. features tcp_usec_ts ecn
Error: either "to" is duplicate, or "ecn" is garbage.

The code exits the while loop as soon as it encounters any feature,
make it more flexible. Tested with the following:

$ ip route add .. dev .. features tcp_usec_ts ecn
$ ip route add .. dev .. features tcp_usec_ts ecn quickack 1

Cc: Stephen Hemminger <stephen@networkplumber.org>
Fixes: a043bea75002 ("ip route: add support for TCP usec TS")
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
---

diff --git a/ip/iproute.c b/ip/iproute.c
index 0e2c171f..c2538894 100644
--- a/ip/iproute.c
+++ b/ip/iproute.c
@@ -1134,6 +1134,27 @@ static int parse_nexthops(struct nlmsghdr *n, struct rtmsg *r,
 	return 0;
 }
 
+static unsigned int parse_features(int *argcp, char ***argvp)
+{
+	unsigned int features = 0;
+	char **argv = *argvp;
+	int argc = *argcp;
+
+	while (++argv, --argc > 0) {
+		if (strcmp(*argv, "ecn") == 0) {
+			features |= RTAX_FEATURE_ECN;
+		} else if (strcmp(*argv, "tcp_usec_ts") == 0) {
+			features |= RTAX_FEATURE_TCP_USEC_TS;
+		} else {
+			break;
+		}
+	}
+
+	*argcp = argc;
+	*argvp = argv;
+	return features;
+}
+
 static int iproute_modify(int cmd, unsigned int flags, int argc, char **argv)
 {
 	struct {
@@ -1374,17 +1395,14 @@ static int iproute_modify(int cmd, unsigned int flags, int argc, char **argv)
 		} else if (matches(*argv, "features") == 0) {
 			unsigned int features = 0;
 
-			while (argc > 0) {
-				NEXT_ARG();
+			features = parse_features(&argc, &argv);
+			if (!features)
+				invarg("\"features\" value not valid\n", *argv);
 
-				if (strcmp(*argv, "ecn") == 0)
-					features |= RTAX_FEATURE_ECN;
-				else if (strcmp(*argv, "tcp_usec_ts") == 0)
-					features |= RTAX_FEATURE_TCP_USEC_TS;
-				else
-					invarg("\"features\" value not valid\n", *argv);
-				break;
-			}
+			/* parse_features stops at the first feature it can't
+			 * parse, rewind one argument back.
+			 */
+			PREV_ARG();
 
 			rta_addattr32(mxrta, sizeof(mxbuf),
 				      RTAX_FEATURES, features);