From 6f21c96a78b835259546d8f3fb4edff0f651d478 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 29 Jan 2016 12:30:19 +0100 Subject: [PATCH] ipv6: enforce flowi6_oif usage in ip6_dst_lookup_tail() The current implementation of ip6_dst_lookup_tail basically ignore the egress ifindex match: if the saddr is set, ip6_route_output() purposefully ignores flowi6_oif, due to the commit d46a9d678e4c ("net: ipv6: Dont add RT6_LOOKUP_F_IFACE flag if saddr set"), if the saddr is 'any' the first route lookup in ip6_dst_lookup_tail fails, but upon failure a second lookup will be performed with saddr set, thus ignoring the ifindex constraint. This commit adds an output route lookup function variant, which allows the caller to specify lookup flags, and modify ip6_dst_lookup_tail() to enforce the ifindex match on the second lookup via said helper. ip6_route_output() becames now a static inline function build on top of ip6_route_output_flags(); as a side effect, out-of-tree modules need now a GPL license to access the output route lookup functionality. Signed-off-by: Paolo Abeni Acked-by: Hannes Frederic Sowa Acked-by: David Ahern Signed-off-by: David S. Miller --- include/net/ip6_route.h | 12 ++++++++++-- net/ipv6/ip6_output.c | 6 +++++- net/ipv6/route.c | 7 +++---- 3 files changed, 18 insertions(+), 7 deletions(-) diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h index 877f682989b8..295d291269e2 100644 --- a/include/net/ip6_route.h +++ b/include/net/ip6_route.h @@ -64,8 +64,16 @@ static inline bool rt6_need_strict(const struct in6_addr *daddr) void ip6_route_input(struct sk_buff *skb); -struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk, - struct flowi6 *fl6); +struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, + struct flowi6 *fl6, int flags); + +static inline struct dst_entry *ip6_route_output(struct net *net, + const struct sock *sk, + struct flowi6 *fl6) +{ + return ip6_route_output_flags(net, sk, fl6, 0); +} + struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, int flags); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 23de98f976d5..a163102f1803 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -909,6 +909,7 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, struct rt6_info *rt; #endif int err; + int flags = 0; /* The correct way to handle this would be to do * ip6_route_get_saddr, and then ip6_route_output; however, @@ -940,10 +941,13 @@ static int ip6_dst_lookup_tail(struct net *net, const struct sock *sk, dst_release(*dst); *dst = NULL; } + + if (fl6->flowi6_oif) + flags |= RT6_LOOKUP_F_IFACE; } if (!*dst) - *dst = ip6_route_output(net, sk, fl6); + *dst = ip6_route_output_flags(net, sk, fl6, flags); err = (*dst)->error; if (err) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 3c8834bc822d..ed446639219c 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1183,11 +1183,10 @@ static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, flags); } -struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk, - struct flowi6 *fl6) +struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk, + struct flowi6 *fl6, int flags) { struct dst_entry *dst; - int flags = 0; bool any_src; dst = l3mdev_rt6_dst_by_oif(net, fl6); @@ -1208,7 +1207,7 @@ struct dst_entry *ip6_route_output(struct net *net, const struct sock *sk, return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_output); } -EXPORT_SYMBOL(ip6_route_output); +EXPORT_SYMBOL_GPL(ip6_route_output_flags); struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) { -- GitLab