udp: Add udp_sock_create for UDP tunnels to open listener socket

Added udp_tunnel.c which can contain some common functions for UDP
tunnels. The first function in this is udp_sock_create which is used
to open the listener port for a UDP tunnel.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Tom Herbert 2014-07-13 19:49:37 -07:00 committed by David S. Miller
parent 39b1c29b7b
commit 8024e02879
4 changed files with 137 additions and 0 deletions

32
include/net/udp_tunnel.h Normal file
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@ -0,0 +1,32 @@
#ifndef __NET_UDP_TUNNEL_H
#define __NET_UDP_TUNNEL_H
struct udp_port_cfg {
u8 family;
/* Used only for kernel-created sockets */
union {
struct in_addr local_ip;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr local_ip6;
#endif
};
union {
struct in_addr peer_ip;
#if IS_ENABLED(CONFIG_IPV6)
struct in6_addr peer_ip6;
#endif
};
__be16 local_udp_port;
__be16 peer_udp_port;
unsigned int use_udp_checksums:1,
use_udp6_tx_checksums:1,
use_udp6_rx_checksums:1;
};
int udp_sock_create(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp);
#endif

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@ -307,6 +307,10 @@ config NET_IPVTI
the notion of a secure tunnel for IPSEC and then use routing protocol
on top.
config NET_UDP_TUNNEL
tristate
default n
config INET_AH
tristate "IP: AH transformation"
select XFRM_ALGO

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@ -22,6 +22,7 @@ obj-$(CONFIG_NET_IPIP) += ipip.o
gre-y := gre_demux.o
obj-$(CONFIG_NET_IPGRE_DEMUX) += gre.o
obj-$(CONFIG_NET_IPGRE) += ip_gre.o
obj-$(CONFIG_NET_UDP_TUNNEL) += udp_tunnel.o
obj-$(CONFIG_NET_IPVTI) += ip_vti.o
obj-$(CONFIG_SYN_COOKIES) += syncookies.o
obj-$(CONFIG_INET_AH) += ah4.o

100
net/ipv4/udp_tunnel.c Normal file
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@ -0,0 +1,100 @@
#include <linux/module.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/udp.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
#include <net/net_namespace.h>
int udp_sock_create(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp)
{
int err = -EINVAL;
struct socket *sock = NULL;
#if IS_ENABLED(CONFIG_IPV6)
if (cfg->family == AF_INET6) {
struct sockaddr_in6 udp6_addr;
err = sock_create_kern(AF_INET6, SOCK_DGRAM, 0, &sock);
if (err < 0)
goto error;
sk_change_net(sock->sk, net);
udp6_addr.sin6_family = AF_INET6;
memcpy(&udp6_addr.sin6_addr, &cfg->local_ip6,
sizeof(udp6_addr.sin6_addr));
udp6_addr.sin6_port = cfg->local_udp_port;
err = kernel_bind(sock, (struct sockaddr *)&udp6_addr,
sizeof(udp6_addr));
if (err < 0)
goto error;
if (cfg->peer_udp_port) {
udp6_addr.sin6_family = AF_INET6;
memcpy(&udp6_addr.sin6_addr, &cfg->peer_ip6,
sizeof(udp6_addr.sin6_addr));
udp6_addr.sin6_port = cfg->peer_udp_port;
err = kernel_connect(sock,
(struct sockaddr *)&udp6_addr,
sizeof(udp6_addr), 0);
}
if (err < 0)
goto error;
udp_set_no_check6_tx(sock->sk, !cfg->use_udp6_tx_checksums);
udp_set_no_check6_rx(sock->sk, !cfg->use_udp6_rx_checksums);
} else
#endif
if (cfg->family == AF_INET) {
struct sockaddr_in udp_addr;
err = sock_create_kern(AF_INET, SOCK_DGRAM, 0, &sock);
if (err < 0)
goto error;
sk_change_net(sock->sk, net);
udp_addr.sin_family = AF_INET;
udp_addr.sin_addr = cfg->local_ip;
udp_addr.sin_port = cfg->local_udp_port;
err = kernel_bind(sock, (struct sockaddr *)&udp_addr,
sizeof(udp_addr));
if (err < 0)
goto error;
if (cfg->peer_udp_port) {
udp_addr.sin_family = AF_INET;
udp_addr.sin_addr = cfg->peer_ip;
udp_addr.sin_port = cfg->peer_udp_port;
err = kernel_connect(sock,
(struct sockaddr *)&udp_addr,
sizeof(udp_addr), 0);
if (err < 0)
goto error;
}
sock->sk->sk_no_check_tx = !cfg->use_udp_checksums;
} else {
return -EPFNOSUPPORT;
}
*sockp = sock;
return 0;
error:
if (sock) {
kernel_sock_shutdown(sock, SHUT_RDWR);
sk_release_kernel(sock->sk);
}
*sockp = NULL;
return err;
}
EXPORT_SYMBOL(udp_sock_create);
MODULE_LICENSE("GPL");