system-linux: Set ignore-df flag on GRE tunnels

mbilker · mbilker · commit c31645bbca01 · 2025-02-09T00:25:06.000Z
This is required to make `gretap` fragment packets according to https://bugzilla.kernel.org/show_bug.cgi?id=14837 Signed-off-by: Matthew Bilker <me@mbilker.us>
diff --git a/system-linux.c b/system-linux.c
@@ -4019,6 +4019,7 @@ static int system_add_gre_tunnel(const char *name, const char *kind,
 			ttl = 64;
 
 		nla_put_u8(nlm, IFLA_GRE_PMTUDISC, set_df ? 1 : 0);
+		nla_put_u8(nlm, IFLA_GRE_IGNORE_DF, set_df ? 0 : 1);
 
 		nla_put_u8(nlm, IFLA_GRE_TOS, tos);
 	}

Original file line number	Diff line number	Diff line change
`@@ -4019,6 +4019,7 @@ static int system_add_gre_tunnel(const char name, const char kind,`
`4019`	`4019`	`ttl = 64;`
`4020`	`4020`
`4021`	`4021`	`nla_put_u8(nlm, IFLA_GRE_PMTUDISC, set_df ? 1 : 0);`
	`4022`	`+ nla_put_u8(nlm, IFLA_GRE_IGNORE_DF, set_df ? 0 : 1);`
`4022`	`4023`
`4023`	`4024`	`nla_put_u8(nlm, IFLA_GRE_TOS, tos);`
`4024`	`4025`	`}`