From 9b1c1ef13b35fa35051b635ca9fbda39fe6bbc70 Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 24 Jun 2019 16:01:08 +0200 Subject: ipv6: constify rt6_nexthop() There is no functional change in this patch, it only prepares the next one. rt6_nexthop() will be used by ip6_dst_lookup_neigh(), which uses const variables. Signed-off-by: Nicolas Dichtel Reported-by: kbuild test robot Acked-by: Nick Desaulniers Signed-off-by: David S. Miller --- net/bluetooth/6lowpan.c | 4 ++-- net/ipv6/ip6_output.c | 2 +- net/netfilter/nf_flow_table_ip.c | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'net') diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c index 19d27bee285e..1555b0c6f7ec 100644 --- a/net/bluetooth/6lowpan.c +++ b/net/bluetooth/6lowpan.c @@ -160,10 +160,10 @@ static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, struct in6_addr *daddr, struct sk_buff *skb) { - struct lowpan_peer *peer; - struct in6_addr *nexthop; struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); int count = atomic_read(&dev->peer_count); + const struct in6_addr *nexthop; + struct lowpan_peer *peer; BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index 834475717110..21efcd02f337 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -59,8 +59,8 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * { struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; + const struct in6_addr *nexthop; struct neighbour *neigh; - struct in6_addr *nexthop; int ret; if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { diff --git a/net/netfilter/nf_flow_table_ip.c b/net/netfilter/nf_flow_table_ip.c index 241317473114..cdfc33517e85 100644 --- a/net/netfilter/nf_flow_table_ip.c +++ b/net/netfilter/nf_flow_table_ip.c @@ -439,9 +439,9 @@ nf_flow_offload_ipv6_hook(void *priv, struct sk_buff *skb, struct nf_flowtable *flow_table = priv; struct flow_offload_tuple tuple = {}; enum flow_offload_tuple_dir dir; + const struct in6_addr *nexthop; struct flow_offload *flow; struct net_device *outdev; - struct in6_addr *nexthop; struct ipv6hdr *ip6h; struct rt6_info *rt; -- cgit From 2c6b55f45d53420d8310d41310e0e2cd41fe073f Mon Sep 17 00:00:00 2001 From: Nicolas Dichtel Date: Mon, 24 Jun 2019 16:01:09 +0200 Subject: ipv6: fix neighbour resolution with raw socket The scenario is the following: the user uses a raw socket to send an ipv6 packet, destinated to a not-connected network, and specify a connected nh. Here is the corresponding python script to reproduce this scenario: import socket IPPROTO_RAW = 255 send_s = socket.socket(socket.AF_INET6, socket.SOCK_RAW, IPPROTO_RAW) # scapy # p = IPv6(src='fd00:100::1', dst='fd00:200::fa')/ICMPv6EchoRequest() # str(p) req = b'`\x00\x00\x00\x00\x08:@\xfd\x00\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xfd\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xfa\x80\x00\x81\xc0\x00\x00\x00\x00' send_s.sendto(req, ('fd00:175::2', 0, 0, 0)) fd00:175::/64 is a connected route and fd00:200::fa is not a connected host. With this scenario, the kernel starts by sending a NS to resolve fd00:175::2. When it receives the NA, it flushes its queue and try to send the initial packet. But instead of sending it, it sends another NS to resolve fd00:200::fa, which obvioulsy fails, thus the packet is dropped. If the user sends again the packet, it now uses the right nh (fd00:175::2). The problem is that ip6_dst_lookup_neigh() uses the rt6i_gateway, which is :: because the associated route is a connected route, thus it uses the dst addr of the packet. Let's use rt6_nexthop() to choose the right nh. Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller --- net/ipv6/route.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'net') diff --git a/net/ipv6/route.c b/net/ipv6/route.c index aade636c6be6..97a843cf164c 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -218,7 +218,8 @@ static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst, { const struct rt6_info *rt = container_of(dst, struct rt6_info, dst); - return ip6_neigh_lookup(&rt->rt6i_gateway, dst->dev, skb, daddr); + return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any), + dst->dev, skb, daddr); } static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr) -- cgit