All callers already initialise ->flowi4_scope with RT_SCOPE_UNIVERSE, either by manual field assignment, memset(0) of the whole structure or implicit structure initialisation of on-stack variables (RT_SCOPE_UNIVERSE actually equals 0). Therefore, we don't need to always initialise ->flowi4_scope in ip_rt_fix_tos(). We only need to reduce the scope to RT_SCOPE_LINK when the special RTO_ONLINK flag is present in the tos. This will allow some code simplification, like removing ip_rt_fix_tos(). Also, the long term idea is to remove RTO_ONLINK entirely by properly initialising ->flowi4_scope, instead of overloading ->flowi4_tos with a special flag. Eventually, this will allow to convert ->flowi4_tos to dscp_t. Signed-off-by: Guillaume Nault <gnault@xxxxxxxxxx> --- It's important for the correctness of this patch that all callers initialise ->flowi4_scope to 0 (in one way or another). Auditing all of them is long, although each case is pretty trivial. If it helps, I can send a patch series that converts implicit initialisation of ->flowi4_scope with an explicit assignment to RT_SCOPE_UNIVERSE. This would also have the advantage of making it clear to future readers that ->flowi4_scope _has_ to be initialised. I haven't sent such patch series to not overwhelm reviewers with trivial and not technically-required changes (there are 40+ places to modify, scattered over 30+ different files). But if anyone prefers explicit initialisation everywhere, then just let me know and I'll send such patches. --- net/ipv4/route.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv4/route.c b/net/ipv4/route.c index e839d424b861..d8f82c0ac132 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -503,8 +503,8 @@ static void ip_rt_fix_tos(struct flowi4 *fl4) __u8 tos = RT_FL_TOS(fl4); fl4->flowi4_tos = tos & IPTOS_RT_MASK; - fl4->flowi4_scope = tos & RTO_ONLINK ? - RT_SCOPE_LINK : RT_SCOPE_UNIVERSE; + if (tos & RTO_ONLINK) + fl4->flowi4_scope = RT_SCOPE_LINK; } static void __build_flow_key(const struct net *net, struct flowi4 *fl4, -- 2.21.3
