net/ipv6/udp: UDP encapsulation: introduce encap_rcv hook into IPv6

Now that the sematics of udpv6_queue_rcv_skb() match IPv4's
udp_queue_rcv_skb(), introduce the UDP encap_rcv() hook for IPv6.

Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Benjamin LaHaise 2012-04-27 08:24:08 +00:00 committed by David S. Miller
parent cb80ef463d
commit d7f3f62167
2 changed files with 42 additions and 0 deletions

View File

@ -268,4 +268,7 @@ extern int udp4_ufo_send_check(struct sk_buff *skb);
extern struct sk_buff *udp4_ufo_fragment(struct sk_buff *skb,
netdev_features_t features);
extern void udp_encap_enable(void);
#if IS_ENABLED(CONFIG_IPV6)
extern void udpv6_encap_enable(void);
#endif
#endif /* _UDP_H */

View File

@ -525,6 +525,14 @@ static __inline__ void udpv6_err(struct sk_buff *skb,
__udp6_lib_err(skb, opt, type, code, offset, info, &udp_table);
}
static struct static_key udpv6_encap_needed __read_mostly;
void udpv6_encap_enable(void)
{
if (!static_key_enabled(&udpv6_encap_needed))
static_key_slow_inc(&udpv6_encap_needed);
}
EXPORT_SYMBOL(udpv6_encap_enable);
int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
struct udp_sock *up = udp_sk(sk);
@ -534,6 +542,37 @@ int udpv6_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
if (!xfrm6_policy_check(sk, XFRM_POLICY_IN, skb))
goto drop;
if (static_key_false(&udpv6_encap_needed) && up->encap_type) {
int (*encap_rcv)(struct sock *sk, struct sk_buff *skb);
/*
* This is an encapsulation socket so pass the skb to
* the socket's udp_encap_rcv() hook. Otherwise, just
* fall through and pass this up the UDP socket.
* up->encap_rcv() returns the following value:
* =0 if skb was successfully passed to the encap
* handler or was discarded by it.
* >0 if skb should be passed on to UDP.
* <0 if skb should be resubmitted as proto -N
*/
/* if we're overly short, let UDP handle it */
encap_rcv = ACCESS_ONCE(up->encap_rcv);
if (skb->len > sizeof(struct udphdr) && encap_rcv != NULL) {
int ret;
ret = encap_rcv(sk, skb);
if (ret <= 0) {
UDP_INC_STATS_BH(sock_net(sk),
UDP_MIB_INDATAGRAMS,
is_udplite);
return -ret;
}
}
/* FALLTHROUGH -- it's a UDP Packet */
}
/*
* UDP-Lite specific tests, ignored on UDP sockets (see net/ipv4/udp.c).
*/