From 7b1311807f3d3eb8bef3ccc53127838b3bea3771 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Tue, 20 Oct 2015 10:28:45 +0200 Subject: [PATCH] ipv4: implement support for NOPREFIXROUTE ifa flag for ipv4 address Currently adding a new ipv4 address always cause the creation of the related network route, with default metric. When a host has multiple interfaces on the same network, multiple routes with the same metric are created. If the userspace wants to set specific metric on each routes, i.e. giving better metric to ethernet links in respect to Wi-Fi ones, the network routes must be deleted and recreated, which is error-prone. This patch implements the support for IFA_F_NOPREFIXROUTE for ipv4 address. When an address is added with such flag set, no associated network route is created, no network route is deleted when said IP is gone and it's up to the user space manage such route. Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller --- net/ipv4/fib_frontend.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index d7c2bb0c4f65..e786873c89f2 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -867,9 +867,10 @@ void fib_add_ifaddr(struct in_ifaddr *ifa) if (!ipv4_is_zeronet(prefix) && !(ifa->ifa_flags & IFA_F_SECONDARY) && (prefix != addr || ifa->ifa_prefixlen < 32)) { - fib_magic(RTM_NEWROUTE, - dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, - prefix, ifa->ifa_prefixlen, prim); + if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) + fib_magic(RTM_NEWROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + prefix, ifa->ifa_prefixlen, prim); /* Add network specific broadcasts, when it takes a sense */ if (ifa->ifa_prefixlen < 31) { @@ -914,9 +915,10 @@ void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) } } else if (!ipv4_is_zeronet(any) && (any != ifa->ifa_local || ifa->ifa_prefixlen < 32)) { - fib_magic(RTM_DELROUTE, - dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, - any, ifa->ifa_prefixlen, prim); + if (!(ifa->ifa_flags & IFA_F_NOPREFIXROUTE)) + fib_magic(RTM_DELROUTE, + dev->flags & IFF_LOOPBACK ? RTN_LOCAL : RTN_UNICAST, + any, ifa->ifa_prefixlen, prim); subnet = 1; } -- 2.20.1