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l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups

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For connected sockets, __l2tp_ip{,6}_bind_lookup() needs to check the
remote IP when looking for a matching socket. Otherwise a connected
socket can receive traffic not originating from its peer.

Drop l2tp_ip_bind_lookup() and l2tp_ip6_bind_lookup() instead of
updating their prototype, as these functions aren't used.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Guillaume Nault 2016-12-30 19:48:20 +01:00 committed by David S. Miller
parent 97b84fd6d9
commit a9b2dff80b
2 changed files with 12 additions and 27 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

19
net/l2tp/l2tp_ip.c
View File

@ -47,7 +47,8 @@ static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk)
return (struct l2tp_ip_sock *)sk;
}
static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,
__be32 raddr, int dif, u32 tunnel_id)
{
struct sock *sk;
@ -61,6 +62,7 @@ static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif
if ((l2tp->conn_id == tunnel_id) &&
net_eq(sock_net(sk), net) &&
!(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&
(!inet->inet_daddr || !raddr || inet->inet_daddr == raddr) &&
(!sk->sk_bound_dev_if || !dif ||
sk->sk_bound_dev_if == dif))
goto found;
@ -71,15 +73,6 @@ found:
return sk;
}
static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)
{
struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);
if (sk)
sock_hold(sk);
return sk;
}
/* When processing receive frames, there are two cases to
* consider. Data frames consist of a non-zero session-id and an
* optional cookie. Control frames consist of a regular L2TP header
@ -183,8 +176,8 @@ pass_up:
struct iphdr *iph = (struct iphdr *) skb_network_header(skb);
read_lock_bh(&l2tp_ip_lock);
sk = __l2tp_ip_bind_lookup(net, iph->daddr, inet_iif(skb),
tunnel_id);
sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,
inet_iif(skb), tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip_lock);
goto discard;
@ -280,7 +273,7 @@ static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
inet->inet_saddr = 0; /* Use device */
write_lock_bh(&l2tp_ip_lock);
if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,
if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,
sk->sk_bound_dev_if, addr->l2tp_conn_id)) {
write_unlock_bh(&l2tp_ip_lock);
ret = -EADDRINUSE;

20
net/l2tp/l2tp_ip6.c
View File

@ -59,12 +59,14 @@ static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
struct in6_addr *laddr,
const struct in6_addr *raddr,
int dif, u32 tunnel_id)
{
struct sock *sk;
sk_for_each_bound(sk, &l2tp_ip6_bind_table) {
const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk);
const struct in6_addr *sk_raddr = &sk->sk_v6_daddr;
struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
if (l2tp == NULL)
@ -73,6 +75,7 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
if ((l2tp->conn_id == tunnel_id) &&
net_eq(sock_net(sk), net) &&
(!sk_laddr || ipv6_addr_any(sk_laddr) || ipv6_addr_equal(sk_laddr, laddr)) &&
(!raddr || ipv6_addr_any(sk_raddr) || ipv6_addr_equal(sk_raddr, raddr)) &&
(!sk->sk_bound_dev_if || !dif ||
sk->sk_bound_dev_if == dif))
goto found;
@ -83,17 +86,6 @@ found:
return sk;
}
static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,
struct in6_addr *laddr,
int dif, u32 tunnel_id)
{
struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);
if (sk)
sock_hold(sk);
return sk;
}
/* When processing receive frames, there are two cases to
* consider. Data frames consist of a non-zero session-id and an
* optional cookie. Control frames consist of a regular L2TP header
@ -197,8 +189,8 @@ pass_up:
struct ipv6hdr *iph = ipv6_hdr(skb);
read_lock_bh(&l2tp_ip6_lock);
sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, inet6_iif(skb),
tunnel_id);
sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr,
inet6_iif(skb), tunnel_id);
if (!sk) {
read_unlock_bh(&l2tp_ip6_lock);
goto discard;
@ -330,7 +322,7 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
rcu_read_unlock();
write_lock_bh(&l2tp_ip6_lock);
if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if,
if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if,
addr->l2tp_conn_id)) {
write_unlock_bh(&l2tp_ip6_lock);
err = -EADDRINUSE;