From: Robert Shearman <rs823p@att.com>
Date: Tue, 28 Nov 2017 11:16:21 +0000 (+0000)
Subject: gre: Fix ttl inherit option
X-Git-Tag: v4.15.0~91
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=079e67816e5f7e2970ee1caa8f6427214993d31a;p=thirdparty%2Fiproute2.git

gre: Fix ttl inherit option

Specifying "... ttl inherit" currently does nothing on a GRE link
modify since the previous ttl value is retrieved up front. Fix this by
explicitly setting ttl to 0 when "inherit" is specified for the
option, since 0 represents the semantics of inherit.

Signed-off-by: Robert Shearman <rs823p@att.com>
---

diff --git a/ip/link_gre.c b/ip/link_gre.c
index 35782caaa..43cb1af61 100644
--- a/ip/link_gre.c
+++ b/ip/link_gre.c
@@ -276,7 +276,8 @@ get_failed:
 				if (uval > 255)
 					invarg("TTL must be <= 255\n", *argv);
 				ttl = uval;
-			}
+			} else
+				ttl = 0;
 		} else if (!matches(*argv, "tos") ||
 			   !matches(*argv, "tclass") ||
 			   !matches(*argv, "dsfield")) {