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 35782caaa68b4c193b6873f370d9590110ed1a4a..43cb1af6196a1aa0b64cf3e7efd4ad115ae0347c 100644 (file)
--- 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")) {