This patch simply adds support for specifying a "not_oif" device in
flowi4 and flowi6 lookups, that will find a matching route that _isn't_
via the specified device.
Signed-off-by: Jason A. Donenfeld <ja...@zx2c4.com>
---
include/net/flow.h | 3 +++
net/ipv4/fib_trie.c | 2 ++
net/ipv6/route.c | 6 +++++-
3 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/net/flow.h b/include/net/flow.h
index 83969ee..29967ad 100644
--- a/include/net/flow.h
+++ b/include/net/flow.h
@@ -26,6 +26,7 @@ struct flowi_tunnel {
struct flowi_common {
int flowic_oif;
+ int flowic_not_oif;
int flowic_iif;
__u32 flowic_mark;
__u8 flowic_tos;
@@ -67,6 +68,7 @@ union flowi_uli {
struct flowi4 {
struct flowi_common __fl_common;
#define flowi4_oif __fl_common.flowic_oif
+#define flowi4_not_oif __fl_common.flowic_not_oif
#define flowi4_iif __fl_common.flowic_iif
#define flowi4_mark __fl_common.flowic_mark
#define flowi4_tos __fl_common.flowic_tos
@@ -125,6 +127,7 @@ static inline void flowi4_update_output(struct flowi4 *fl4,
int oif, __u8 tos,
struct flowi6 {
struct flowi_common __fl_common;
#define flowi6_oif __fl_common.flowic_oif
+#define flowi6_not_oif __fl_common.flowic_not_oif
#define flowi6_iif __fl_common.flowic_iif
#define flowi6_mark __fl_common.flowic_mark
#define flowi6_tos __fl_common.flowic_tos
diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 7aea0cc..d03e991 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1429,6 +1429,8 @@ found:
flp->flowi4_oif != nh->nh_oif)
continue;
}
+ if (flp->flowi4_not_oif && flp->flowi4_not_oif ==
nh->nh_oif)
+ continue;
if (!(fib_flags & FIB_LOOKUP_NOREF))
atomic_inc(&fi->fib_clntref);
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 3c8834b..2a793b5 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -467,6 +467,7 @@ static inline struct rt6_info *rt6_device_match(struct net
*net,
struct rt6_info *rt,
const struct in6_addr
*saddr,
int oif,
+ int not_oif,
int flags)
{
struct rt6_info *local = NULL;
@@ -478,6 +479,9 @@ static inline struct rt6_info *rt6_device_match(struct net
*net,
for (sprt = rt; sprt; sprt = sprt->dst.rt6_next) {
struct net_device *dev = sprt->dst.dev;
+ if (not_oif && dev->ifindex == not_oif)
+ continue;
+
if (oif) {
if (dev->ifindex == oif)
return sprt;
@@ -856,7 +860,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net
*net,
fn = fib6_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
rt = fn->leaf;
- rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif, flags);
+ rt = rt6_device_match(net, rt, &fl6->saddr, fl6->flowi6_oif,
fl6->flowi6_not_oif, flags);
if (rt->rt6i_nsiblings && fl6->flowi6_oif == 0)
rt = rt6_multipath_select(rt, fl6, fl6->flowi6_oif, flags);
if (rt == net->ipv6.ip6_null_entry) {
--
2.7.0
