linux/net/ipv4/udp_tunnel.c
Alexis Bauvin da5095d052 udp_tunnel: add config option to bind to a device
UDP tunnel sockets are always opened unbound to a specific device. This
patch allow the socket to be bound on a custom device, which
incidentally makes UDP tunnels VRF-aware if binding to an l3mdev.

Signed-off-by: Alexis Bauvin <abauvin@scaleway.com>
Reviewed-by: Amine Kherbouche <akherbouche@scaleway.com>
Tested-by: Amine Kherbouche <akherbouche@scaleway.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03 14:15:26 -08:00

235 lines
5.7 KiB
C

#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/dst_metadata.h>
#include <net/net_namespace.h>
#include <net/udp.h>
#include <net/udp_tunnel.h>
int udp_sock_create4(struct net *net, struct udp_port_cfg *cfg,
struct socket **sockp)
{
int err;
struct socket *sock = NULL;
struct sockaddr_in udp_addr;
err = sock_create_kern(net, AF_INET, SOCK_DGRAM, 0, &sock);
if (err < 0)
goto error;
if (cfg->bind_ifindex) {
struct net_device *dev;
dev = dev_get_by_index(net, cfg->bind_ifindex);
if (!dev) {
err = -ENODEV;
goto error;
}
err = kernel_setsockopt(sock, SOL_SOCKET, SO_BINDTODEVICE,
dev->name, strlen(dev->name) + 1);
dev_put(dev);
if (err < 0)
goto error;
}
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;
*sockp = sock;
return 0;
error:
if (sock) {
kernel_sock_shutdown(sock, SHUT_RDWR);
sock_release(sock);
}
*sockp = NULL;
return err;
}
EXPORT_SYMBOL(udp_sock_create4);
void setup_udp_tunnel_sock(struct net *net, struct socket *sock,
struct udp_tunnel_sock_cfg *cfg)
{
struct sock *sk = sock->sk;
/* Disable multicast loopback */
inet_sk(sk)->mc_loop = 0;
/* Enable CHECKSUM_UNNECESSARY to CHECKSUM_COMPLETE conversion */
inet_inc_convert_csum(sk);
rcu_assign_sk_user_data(sk, cfg->sk_user_data);
udp_sk(sk)->encap_type = cfg->encap_type;
udp_sk(sk)->encap_rcv = cfg->encap_rcv;
udp_sk(sk)->encap_err_lookup = cfg->encap_err_lookup;
udp_sk(sk)->encap_destroy = cfg->encap_destroy;
udp_sk(sk)->gro_receive = cfg->gro_receive;
udp_sk(sk)->gro_complete = cfg->gro_complete;
udp_tunnel_encap_enable(sock);
}
EXPORT_SYMBOL_GPL(setup_udp_tunnel_sock);
void udp_tunnel_push_rx_port(struct net_device *dev, struct socket *sock,
unsigned short type)
{
struct sock *sk = sock->sk;
struct udp_tunnel_info ti;
if (!dev->netdev_ops->ndo_udp_tunnel_add ||
!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
ti.type = type;
ti.sa_family = sk->sk_family;
ti.port = inet_sk(sk)->inet_sport;
dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
}
EXPORT_SYMBOL_GPL(udp_tunnel_push_rx_port);
void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
unsigned short type)
{
struct sock *sk = sock->sk;
struct udp_tunnel_info ti;
if (!dev->netdev_ops->ndo_udp_tunnel_del ||
!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
return;
ti.type = type;
ti.sa_family = sk->sk_family;
ti.port = inet_sk(sk)->inet_sport;
dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
}
EXPORT_SYMBOL_GPL(udp_tunnel_drop_rx_port);
/* Notify netdevs that UDP port started listening */
void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
{
struct sock *sk = sock->sk;
struct net *net = sock_net(sk);
struct udp_tunnel_info ti;
struct net_device *dev;
ti.type = type;
ti.sa_family = sk->sk_family;
ti.port = inet_sk(sk)->inet_sport;
rcu_read_lock();
for_each_netdev_rcu(net, dev) {
if (!dev->netdev_ops->ndo_udp_tunnel_add)
continue;
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
continue;
dev->netdev_ops->ndo_udp_tunnel_add(dev, &ti);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
/* Notify netdevs that UDP port is no more listening */
void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
{
struct sock *sk = sock->sk;
struct net *net = sock_net(sk);
struct udp_tunnel_info ti;
struct net_device *dev;
ti.type = type;
ti.sa_family = sk->sk_family;
ti.port = inet_sk(sk)->inet_sport;
rcu_read_lock();
for_each_netdev_rcu(net, dev) {
if (!dev->netdev_ops->ndo_udp_tunnel_del)
continue;
if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
continue;
dev->netdev_ops->ndo_udp_tunnel_del(dev, &ti);
}
rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
__be32 src, __be32 dst, __u8 tos, __u8 ttl,
__be16 df, __be16 src_port, __be16 dst_port,
bool xnet, bool nocheck)
{
struct udphdr *uh;
__skb_push(skb, sizeof(*uh));
skb_reset_transport_header(skb);
uh = udp_hdr(skb);
uh->dest = dst_port;
uh->source = src_port;
uh->len = htons(skb->len);
memset(&(IPCB(skb)->opt), 0, sizeof(IPCB(skb)->opt));
udp_set_csum(nocheck, skb, src, dst, skb->len);
iptunnel_xmit(sk, rt, skb, src, dst, IPPROTO_UDP, tos, ttl, df, xnet);
}
EXPORT_SYMBOL_GPL(udp_tunnel_xmit_skb);
void udp_tunnel_sock_release(struct socket *sock)
{
rcu_assign_sk_user_data(sock->sk, NULL);
kernel_sock_shutdown(sock, SHUT_RDWR);
sock_release(sock);
}
EXPORT_SYMBOL_GPL(udp_tunnel_sock_release);
struct metadata_dst *udp_tun_rx_dst(struct sk_buff *skb, unsigned short family,
__be16 flags, __be64 tunnel_id, int md_size)
{
struct metadata_dst *tun_dst;
struct ip_tunnel_info *info;
if (family == AF_INET)
tun_dst = ip_tun_rx_dst(skb, flags, tunnel_id, md_size);
else
tun_dst = ipv6_tun_rx_dst(skb, flags, tunnel_id, md_size);
if (!tun_dst)
return NULL;
info = &tun_dst->u.tun_info;
info->key.tp_src = udp_hdr(skb)->source;
info->key.tp_dst = udp_hdr(skb)->dest;
if (udp_hdr(skb)->check)
info->key.tun_flags |= TUNNEL_CSUM;
return tun_dst;
}
EXPORT_SYMBOL_GPL(udp_tun_rx_dst);
MODULE_LICENSE("GPL");