Commit 72331bc0 authored by Shmulik Ladkani's avatar Shmulik Ladkani Committed by David S. Miller
Browse files

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: default avatarAmi Koren <amikoren@yahoo.com>
Signed-off-by: default avatarShmulik Ladkani <shmulik.ladkani@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cdaf0b83

net/ipv6/route.c

+27 −7
Original line number Diff line number Diff line
@@ -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,

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