ipv6: Fix RTM_GETROUTE's interpretation of RTA_IIF to be consistent with ipv4

In IPv4, if an RTA_IIF attribute is specified within an RTM_GETROUTE
message, then a route is searched as if a packet was received on the
specified 'iif' interface.

However in IPv6, RTA_IIF is not interpreted in the same way:
'inet6_rtm_getroute()' always calls 'ip6_route_output()', regardless the
RTA_IIF attribute.

As a result, in IPv6 there's no way to use RTM_GETROUTE in order to look
for a route as if a packet was received on a specific interface.

Fix 'inet6_rtm_getroute()' so that RTA_IIF is interpreted as "lookup a
route as if a packet was received on the specified interface", similar
to IPv4's 'inet_rtm_getroute()' interpretation.

Reported-by: Ami Koren <amikoren@yahoo.com>
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Shmulik Ladkani 2012-04-01 04:03:45 +00:00 committed by David S. Miller
parent cdaf0b835d
commit 72331bc0cd

View file

@ -881,6 +881,16 @@ static struct rt6_info *ip6_pol_route_input(struct net *net, struct fib6_table *
return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, flags);
}
static struct dst_entry *ip6_route_input_lookup(struct net *net,
struct net_device *dev,
struct flowi6 *fl6, int flags)
{
if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
flags |= RT6_LOOKUP_F_IFACE;
return fib6_rule_lookup(net, fl6, flags, ip6_pol_route_input);
}
void ip6_route_input(struct sk_buff *skb)
{
const struct ipv6hdr *iph = ipv6_hdr(skb);
@ -895,10 +905,7 @@ void ip6_route_input(struct sk_buff *skb)
.flowi6_proto = iph->nexthdr,
};
if (rt6_need_strict(&iph->daddr) && skb->dev->type != ARPHRD_PIMREG)
flags |= RT6_LOOKUP_F_IFACE;
skb_dst_set(skb, fib6_rule_lookup(net, &fl6, flags, ip6_pol_route_input));
skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags));
}
static struct rt6_info *ip6_pol_route_output(struct net *net, struct fib6_table *table,
@ -2537,7 +2544,7 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
struct sk_buff *skb;
struct rtmsg *rtm;
struct flowi6 fl6;
int err, iif = 0;
int err, iif = 0, oif = 0;
err = nlmsg_parse(nlh, sizeof(*rtm), tb, RTA_MAX, rtm_ipv6_policy);
if (err < 0)
@ -2564,15 +2571,29 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
iif = nla_get_u32(tb[RTA_IIF]);
if (tb[RTA_OIF])
fl6.flowi6_oif = nla_get_u32(tb[RTA_OIF]);
oif = nla_get_u32(tb[RTA_OIF]);
if (iif) {
struct net_device *dev;
int flags = 0;
dev = __dev_get_by_index(net, iif);
if (!dev) {
err = -ENODEV;
goto errout;
}
fl6.flowi6_iif = iif;
if (!ipv6_addr_any(&fl6.saddr))
flags |= RT6_LOOKUP_F_HAS_SADDR;
rt = (struct rt6_info *)ip6_route_input_lookup(net, dev, &fl6,
flags);
} else {
fl6.flowi6_oif = oif;
rt = (struct rt6_info *)ip6_route_output(net, NULL, &fl6);
}
skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
@ -2587,7 +2608,6 @@ static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr* nlh, void
skb_reset_mac_header(skb);
skb_reserve(skb, MAX_HEADER + sizeof(struct ipv6hdr));
rt = (struct rt6_info*) ip6_route_output(net, NULL, &fl6);
skb_dst_set(skb, &rt->dst);
err = rt6_fill_node(net, skb, rt, &fl6.daddr, &fl6.saddr, iif,