- 根目录:
- net
- tipc
- udp_media.c
/* net/tipc/udp_media.c: IP bearer support for TIPC
*
* Copyright (c) 2015, Ericsson AB
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/socket.h>
#include <linux/ip.h>
#include <linux/udp.h>
#include <linux/inet.h>
#include <linux/inetdevice.h>
#include <linux/igmp.h>
#include <linux/kernel.h>
#include <linux/workqueue.h>
#include <linux/list.h>
#include <net/sock.h>
#include <net/ip.h>
#include <net/udp_tunnel.h>
#include <net/addrconf.h>
#include <linux/tipc_netlink.h>
#include "core.h"
#include "bearer.h"
/* IANA assigned UDP port */
#define UDP_PORT_DEFAULT 6118
static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
[TIPC_NLA_UDP_UNSPEC] = {.type = NLA_UNSPEC},
[TIPC_NLA_UDP_LOCAL] = {.type = NLA_BINARY,
.len = sizeof(struct sockaddr_storage)},
[TIPC_NLA_UDP_REMOTE] = {.type = NLA_BINARY,
.len = sizeof(struct sockaddr_storage)},
};
/**
* struct udp_media_addr - IP/UDP addressing information
*
* This is the bearer level originating address used in neighbor discovery
* messages, and all fields should be in network byte order
*/
struct udp_media_addr {
__be16 proto;
__be16 udp_port;
union {
struct in_addr ipv4;
struct in6_addr ipv6;
};
};
/**
* struct udp_bearer - ip/udp bearer data structure
* @bearer: associated generic tipc bearer
* @ubsock: bearer associated socket
* @ifindex: local address scope
* @work: used to schedule deferred work on a bearer
*/
struct udp_bearer {
struct tipc_bearer __rcu *bearer;
struct socket *ubsock;
u32 ifindex;
struct work_struct work;
};
/* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
struct udp_media_addr *ua)
{
memset(addr, 0, sizeof(struct tipc_media_addr));
addr->media_id = TIPC_MEDIA_TYPE_UDP;
memcpy(addr->value, ua, sizeof(struct udp_media_addr));
if (ntohs(ua->proto) == ETH_P_IP) {
if (ipv4_is_multicast(ua->ipv4.s_addr))
addr->broadcast = 1;
} else if (ntohs(ua->proto) == ETH_P_IPV6) {
if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
addr->broadcast = 1;
} else {
pr_err("Invalid UDP media address\n");
}
}
/* tipc_udp_addr2str - convert ip/udp address to string */
static int tipc_udp_addr2str(struct tipc_media_addr *a, char *buf, int size)
{
struct udp_media_addr *ua = (struct udp_media_addr *)&a->value;
if (ntohs(ua->proto) == ETH_P_IP)
snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
else if (ntohs(ua->proto) == ETH_P_IPV6)
snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
else
pr_err("Invalid UDP media address\n");
return 0;
}
/* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
static int tipc_udp_msg2addr(struct tipc_bearer *b, struct tipc_media_addr *a,
char *msg)
{
struct udp_media_addr *ua;
ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
return -EINVAL;
tipc_udp_media_addr_set(a, ua);
return 0;
}
/* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
static int tipc_udp_addr2msg(char *msg, struct tipc_media_addr *a)
{
memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
sizeof(struct udp_media_addr));
return 0;
}
/* tipc_send_msg - enqueue a send request */
static int tipc_udp_send_msg(struct net *net, struct sk_buff *skb,
struct tipc_bearer *b,
struct tipc_media_addr *dest)
{
int ttl, err = 0;
struct udp_bearer *ub;
struct udp_media_addr *dst = (struct udp_media_addr *)&dest->value;
struct udp_media_addr *src = (struct udp_media_addr *)&b->addr.value;
struct sk_buff *clone;
struct rtable *rt;
clone = skb_clone(skb, GFP_ATOMIC);
skb_set_inner_protocol(clone, htons(ETH_P_TIPC));
ub = rcu_dereference_rtnl(b->media_ptr);
if (!ub) {
err = -ENODEV;
goto tx_error;
}
if (dst->proto == htons(ETH_P_IP)) {
struct flowi4 fl = {
.daddr = dst->ipv4.s_addr,
.saddr = src->ipv4.s_addr,
.flowi4_mark = clone->mark,
.flowi4_proto = IPPROTO_UDP
};
rt = ip_route_output_key(net, &fl);
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
goto tx_error;
}
ttl = ip4_dst_hoplimit(&rt->dst);
err = udp_tunnel_xmit_skb(rt, ub->ubsock->sk, clone,
src->ipv4.s_addr,
dst->ipv4.s_addr, 0, ttl, 0,
src->udp_port, dst->udp_port,
false, true);
if (err < 0) {
ip_rt_put(rt);
goto tx_error;
}
#if IS_ENABLED(CONFIG_IPV6)
} else {
struct dst_entry *ndst;
struct flowi6 fl6 = {
.flowi6_oif = ub->ifindex,
.daddr = dst->ipv6,
.saddr = src->ipv6,
.flowi6_proto = IPPROTO_UDP
};
err = ipv6_stub->ipv6_dst_lookup(ub->ubsock->sk, &ndst, &fl6);
if (err)
goto tx_error;
ttl = ip6_dst_hoplimit(ndst);
err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, clone,
ndst->dev, &src->ipv6,
&dst->ipv6, 0, ttl, src->udp_port,
dst->udp_port, false);
#endif
}
return err;
tx_error:
kfree_skb(clone);
return err;
}
/* tipc_udp_recv - read data from bearer socket */
static int tipc_udp_recv(struct sock *sk, struct sk_buff *skb)
{
struct udp_bearer *ub;
struct tipc_bearer *b;
ub = rcu_dereference_sk_user_data(sk);
if (!ub) {
pr_err_ratelimited("Failed to get UDP bearer reference");
kfree_skb(skb);
return 0;
}
skb_pull(skb, sizeof(struct udphdr));
rcu_read_lock();
b = rcu_dereference_rtnl(ub->bearer);
if (b) {
tipc_rcv(sock_net(sk), skb, b);
rcu_read_unlock();
return 0;
}
rcu_read_unlock();
kfree_skb(skb);
return 0;
}
static int enable_mcast(struct udp_bearer *ub, struct udp_media_addr *remote)
{
int err = 0;
struct ip_mreqn mreqn;
struct sock *sk = ub->ubsock->sk;
if (ntohs(remote->proto) == ETH_P_IP) {
if (!ipv4_is_multicast(remote->ipv4.s_addr))
return 0;
mreqn.imr_multiaddr = remote->ipv4;
mreqn.imr_ifindex = ub->ifindex;
err = ip_mc_join_group(sk, &mreqn);
#if IS_ENABLED(CONFIG_IPV6)
} else {
if (!ipv6_addr_is_multicast(&remote->ipv6))
return 0;
err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
&remote->ipv6);
#endif
}
return err;
}
/**
* parse_options - build local/remote addresses from configuration
* @attrs: netlink config data
* @ub: UDP bearer instance
* @local: local bearer IP address/port
* @remote: peer or multicast IP/port
*/
static int parse_options(struct nlattr *attrs[], struct udp_bearer *ub,
struct udp_media_addr *local,
struct udp_media_addr *remote)
{
struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
struct sockaddr_storage *sa_local, *sa_remote;
if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
goto err;
if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
attrs[TIPC_NLA_BEARER_UDP_OPTS],
tipc_nl_udp_policy))
goto err;
if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
} else {
err:
pr_err("Invalid UDP bearer configuration");
return -EINVAL;
}
if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
struct sockaddr_in *ip4;
ip4 = (struct sockaddr_in *)sa_local;
local->proto = htons(ETH_P_IP);
local->udp_port = ip4->sin_port;
local->ipv4.s_addr = ip4->sin_addr.s_addr;
ip4 = (struct sockaddr_in *)sa_remote;
remote->proto = htons(ETH_P_IP);
remote->udp_port = ip4->sin_port;
remote->ipv4.s_addr = ip4->sin_addr.s_addr;
return 0;
#if IS_ENABLED(CONFIG_IPV6)
} else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
struct sockaddr_in6 *ip6;
ip6 = (struct sockaddr_in6 *)sa_local;
local->proto = htons(ETH_P_IPV6);
local->udp_port = ip6->sin6_port;
local->ipv6 = ip6->sin6_addr;
ub->ifindex = ip6->sin6_scope_id;
ip6 = (struct sockaddr_in6 *)sa_remote;
remote->proto = htons(ETH_P_IPV6);
remote->udp_port = ip6->sin6_port;
remote->ipv6 = ip6->sin6_addr;
return 0;
#endif
}
return -EADDRNOTAVAIL;
}
/**
* tipc_udp_enable - callback to create a new udp bearer instance
* @net: network namespace
* @b: pointer to generic tipc_bearer
* @attrs: netlink bearer configuration
*
* validate the bearer parameters and initialize the udp bearer
* rtnl_lock should be held
*/
static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
struct nlattr *attrs[])
{
int err = -EINVAL;
struct udp_bearer *ub;
struct udp_media_addr *remote;
struct udp_media_addr local = {0};
struct udp_port_cfg udp_conf = {0};
struct udp_tunnel_sock_cfg tuncfg = {NULL};
ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
if (!ub)
return -ENOMEM;
remote = (struct udp_media_addr *)&b->bcast_addr.value;
memset(remote, 0, sizeof(struct udp_media_addr));
err = parse_options(attrs, ub, &local, remote);
if (err)
goto err;
b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
b->bcast_addr.broadcast = 1;
rcu_assign_pointer(b->media_ptr, ub);
rcu_assign_pointer(ub->bearer, b);
tipc_udp_media_addr_set(&b->addr, &local);
if (local.proto == htons(ETH_P_IP)) {
struct net_device *dev;
dev = __ip_dev_find(net, local.ipv4.s_addr, false);
if (!dev) {
err = -ENODEV;
goto err;
}
udp_conf.family = AF_INET;
udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
udp_conf.use_udp_checksums = false;
ub->ifindex = dev->ifindex;
b->mtu = dev->mtu - sizeof(struct iphdr)
- sizeof(struct udphdr);
#if IS_ENABLED(CONFIG_IPV6)
} else if (local.proto == htons(ETH_P_IPV6)) {
udp_conf.family = AF_INET6;
udp_conf.use_udp6_tx_checksums = true;
udp_conf.use_udp6_rx_checksums = true;
udp_conf.local_ip6 = in6addr_any;
b->mtu = 1280;
#endif
} else {
err = -EAFNOSUPPORT;
goto err;
}
udp_conf.local_udp_port = local.udp_port;
err = udp_sock_create(net, &udp_conf, &ub->ubsock);
if (err)
goto err;
tuncfg.sk_user_data = ub;
tuncfg.encap_type = 1;
tuncfg.encap_rcv = tipc_udp_recv;
tuncfg.encap_destroy = NULL;
setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
if (enable_mcast(ub, remote))
goto err;
return 0;
err:
kfree(ub);
return err;
}
/* cleanup_bearer - break the socket/bearer association */
static void cleanup_bearer(struct work_struct *work)
{
struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
if (ub->ubsock)
udp_tunnel_sock_release(ub->ubsock);
synchronize_net();
kfree(ub);
}
/* tipc_udp_disable - detach bearer from socket */
static void tipc_udp_disable(struct tipc_bearer *b)
{
struct udp_bearer *ub;
ub = rcu_dereference_rtnl(b->media_ptr);
if (!ub) {
pr_err("UDP bearer instance not found\n");
return;
}
if (ub->ubsock)
sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
RCU_INIT_POINTER(b->media_ptr, NULL);
RCU_INIT_POINTER(ub->bearer, NULL);
/* sock_release need to be done outside of rtnl lock */
INIT_WORK(&ub->work, cleanup_bearer);
schedule_work(&ub->work);
}
struct tipc_media udp_media_info = {
.send_msg = tipc_udp_send_msg,
.enable_media = tipc_udp_enable,
.disable_media = tipc_udp_disable,
.addr2str = tipc_udp_addr2str,
.addr2msg = tipc_udp_addr2msg,
.msg2addr = tipc_udp_msg2addr,
.priority = TIPC_DEF_LINK_PRI,
.tolerance = TIPC_DEF_LINK_TOL,
.window = TIPC_DEF_LINK_WIN,
.type_id = TIPC_MEDIA_TYPE_UDP,
.hwaddr_len = 0,
.name = "udp"
};