[mirror_ubuntu-bionic-kernel.git] / 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"
#include "netlink.h"

/* IANA assigned UDP port */
#define UDP_PORT_DEFAULT	6118

#define UDP_MIN_HEADROOM        48

/**
 * 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	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->port));
	else if (ntohs(ua->proto) == ETH_P_IPV6)
		snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->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 rtable *rt;

	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
		err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
		if (err)
			goto tx_error;
	}

	skb_set_inner_protocol(skb, 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 = skb->mark,
			.flowi4_proto = IPPROTO_UDP
		};
		rt = ip_route_output_key(net, &fl);
		if (IS_ERR(rt)) {
			err = PTR_ERR(rt);
			goto tx_error;
		}

		skb->dev = rt->dst.dev;
		ttl = ip4_dst_hoplimit(&rt->dst);
		udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
				    dst->ipv4.s_addr, 0, ttl, 0, src->port,
				    dst->port, false, true);
#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(net, ub->ubsock->sk, &ndst,
						 &fl6);
		if (err)
			goto tx_error;
		ttl = ip6_dst_hoplimit(ndst);
		err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
					   ndst->dev, &src->ipv6,
					   &dst->ipv6, 0, ttl, 0, src->port,
					   dst->port, false);
#endif
	}
	return err;

tx_error:
	kfree_skb(skb);
	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]) {
		nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL],
			   sizeof(sa_local));
		nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE],
			   sizeof(sa_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->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->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) {
		int atype;
		struct sockaddr_in6 *ip6;

		ip6 = (struct sockaddr_in6 *)&sa_local;
		atype = ipv6_addr_type(&ip6->sin6_addr);
		if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id)
			return -EINVAL;

		local->proto = htons(ETH_P_IPV6);
		local->port = ip6->sin6_port;
		memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
		ub->ifindex = ip6->sin6_scope_id;

		ip6 = (struct sockaddr_in6 *)&sa_remote;
		remote->proto = htons(ETH_P_IPV6);
		remote->port = ip6->sin6_port;
		memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_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.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);

	err = enable_mcast(ub, remote);
	if (err)
		goto err;
	return 0;
err:
	if (ub->ubsock)
		udp_tunnel_sock_release(ub->ubsock);
	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(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"
};
Commit	Line	Data
d0f91938 EH	1	/* net/tipc/udp_media.c: IP bearer support for TIPC
	2	*
	3	* Copyright (c) 2015, Ericsson AB
	4	* All rights reserved.
	5	*
	6	* Redistribution and use in source and binary forms, with or without
	7	* modification, are permitted provided that the following conditions are met:
	8	*
	9	* 1. Redistributions of source code must retain the above copyright
	10	* notice, this list of conditions and the following disclaimer.
	11	* 2. Redistributions in binary form must reproduce the above copyright
	12	* notice, this list of conditions and the following disclaimer in the
	13	* documentation and/or other materials provided with the distribution.
	14	* 3. Neither the names of the copyright holders nor the names of its
	15	* contributors may be used to endorse or promote products derived from
	16	* this software without specific prior written permission.
	17	*
	18	* Alternatively, this software may be distributed under the terms of the
	19	* GNU General Public License ("GPL") version 2 as published by the Free
	20	* Software Foundation.
	21	*
	22	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	23	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	25	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	26	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	27	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	28	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	29	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	30	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	31	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
	32	* POSSIBILITY OF SUCH DAMAGE.
	33	*/
	34
	35	#include <linux/socket.h>
	36	#include <linux/ip.h>
	37	#include <linux/udp.h>
	38	#include <linux/inet.h>
	39	#include <linux/inetdevice.h>
	40	#include <linux/igmp.h>
	41	#include <linux/kernel.h>
	42	#include <linux/workqueue.h>
	43	#include <linux/list.h>
	44	#include <net/sock.h>
	45	#include <net/ip.h>
	46	#include <net/udp_tunnel.h>
446981e5	47	#include <net/addrconf.h>
d0f91938 EH	48	#include <linux/tipc_netlink.h>
	49	#include "core.h"
	50	#include "bearer.h"
49cc66ea	51	#include "netlink.h"
d0f91938 EH	52
	53	/* IANA assigned UDP port */
	54	#define UDP_PORT_DEFAULT 6118
	55
9bd160bf	56	#define UDP_MIN_HEADROOM 48
e5356794	57
d0f91938 EH	58	/**
	59	* struct udp_media_addr - IP/UDP addressing information
	60	*
	61	* This is the bearer level originating address used in neighbor discovery
	62	* messages, and all fields should be in network byte order
	63	*/
	64	struct udp_media_addr {
	65	__be16 proto;
bc3a334c	66	__be16 port;
d0f91938 EH	67	union {
	68	struct in_addr ipv4;
	69	struct in6_addr ipv6;
	70	};
	71	};
	72
	73	/**
	74	* struct udp_bearer - ip/udp bearer data structure
	75	* @bearer: associated generic tipc bearer
	76	* @ubsock: bearer associated socket
	77	* @ifindex: local address scope
	78	* @work: used to schedule deferred work on a bearer
	79	*/
	80	struct udp_bearer {
	81	struct tipc_bearer __rcu *bearer;
	82	struct socket *ubsock;
	83	u32 ifindex;
	84	struct work_struct work;
	85	};
	86
	87	/* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
	88	static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
	89	struct udp_media_addr *ua)
	90	{
	91	memset(addr, 0, sizeof(struct tipc_media_addr));
	92	addr->media_id = TIPC_MEDIA_TYPE_UDP;
	93	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
	94	if (ntohs(ua->proto) == ETH_P_IP) {
	95	if (ipv4_is_multicast(ua->ipv4.s_addr))
	96	addr->broadcast = 1;
	97	} else if (ntohs(ua->proto) == ETH_P_IPV6) {
	98	if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
	99	addr->broadcast = 1;
	100	} else {
	101	pr_err("Invalid UDP media address\n");
	102	}
	103	}
	104
	105	/* tipc_udp_addr2str - convert ip/udp address to string */
	106	static int tipc_udp_addr2str(struct tipc_media_addr a, char buf, int size)
	107	{
	108	struct udp_media_addr ua = (struct udp_media_addr )&a->value;
	109
	110	if (ntohs(ua->proto) == ETH_P_IP)
bc3a334c	111	snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->port));
d0f91938	112	else if (ntohs(ua->proto) == ETH_P_IPV6)
bc3a334c	113	snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->port));
d0f91938 EH	114	else
	115	pr_err("Invalid UDP media address\n");
	116	return 0;
	117	}
	118
	119	/* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
	120	static int tipc_udp_msg2addr(struct tipc_bearer b, struct tipc_media_addr a,
	121	char *msg)
	122	{
	123	struct udp_media_addr *ua;
	124
	125	ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
	126	if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
	127	return -EINVAL;
	128	tipc_udp_media_addr_set(a, ua);
	129	return 0;
	130	}
	131
	132	/* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
	133	static int tipc_udp_addr2msg(char msg, struct tipc_media_addr a)
	134	{
	135	memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
	136	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
	137	memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
	138	sizeof(struct udp_media_addr));
	139	return 0;
	140	}
	141
	142	/* tipc_send_msg - enqueue a send request */
	143	static int tipc_udp_send_msg(struct net net, struct sk_buff skb,
	144	struct tipc_bearer *b,
	145	struct tipc_media_addr *dest)
	146	{
	147	int ttl, err = 0;
	148	struct udp_bearer *ub;
	149	struct udp_media_addr dst = (struct udp_media_addr )&dest->value;
	150	struct udp_media_addr src = (struct udp_media_addr )&b->addr.value;
d0f91938 EH	151	struct rtable *rt;
d0f91938 EH	152
7098356b YX	153	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
	154	err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
	155	if (err)
	156	goto tx_error;
	157	}
e5356794	158
7214bcf8	159	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
d0f91938 EH	160	ub = rcu_dereference_rtnl(b->media_ptr);
	161	if (!ub) {
	162	err = -ENODEV;
	163	goto tx_error;
	164	}
4fee6be8	165	if (dst->proto == htons(ETH_P_IP)) {
d0f91938 EH	166	struct flowi4 fl = {
	167	.daddr = dst->ipv4.s_addr,
	168	.saddr = src->ipv4.s_addr,
7214bcf8	169	.flowi4_mark = skb->mark,
d0f91938 EH	170	.flowi4_proto = IPPROTO_UDP
	171	};
	172	rt = ip_route_output_key(net, &fl);
	173	if (IS_ERR(rt)) {
	174	err = PTR_ERR(rt);
	175	goto tx_error;
	176	}
9b300960 RA	177
9b300960 RA	178	skb->dev = rt->dst.dev;
d0f91938	179	ttl = ip4_dst_hoplimit(&rt->dst);
039f5062	180	udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
bc3a334c RA	181	dst->ipv4.s_addr, 0, ttl, 0, src->port,
bc3a334c RA	182	dst->port, false, true);
d0f91938 EH	183	#if IS_ENABLED(CONFIG_IPV6)
	184	} else {
	185	struct dst_entry *ndst;
	186	struct flowi6 fl6 = {
	187	.flowi6_oif = ub->ifindex,
	188	.daddr = dst->ipv6,
	189	.saddr = src->ipv6,
	190	.flowi6_proto = IPPROTO_UDP
	191	};
343d60aa RP	192	err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
343d60aa RP	193	&fl6);
d0f91938 EH	194	if (err)
	195	goto tx_error;
	196	ttl = ip6_dst_hoplimit(ndst);
7214bcf8	197	err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
79b16aad	198	ndst->dev, &src->ipv6,
bc3a334c RA	199	&dst->ipv6, 0, ttl, 0, src->port,
bc3a334c RA	200	dst->port, false);
d0f91938 EH	201	#endif
	202	}
	203	return err;
	204
	205	tx_error:
7214bcf8	206	kfree_skb(skb);
d0f91938 EH	207	return err;
	208	}
	209
	210	/* tipc_udp_recv - read data from bearer socket */
	211	static int tipc_udp_recv(struct sock sk, struct sk_buff skb)
	212	{
	213	struct udp_bearer *ub;
	214	struct tipc_bearer *b;
	215
	216	ub = rcu_dereference_sk_user_data(sk);
	217	if (!ub) {
	218	pr_err_ratelimited("Failed to get UDP bearer reference");
	219	kfree_skb(skb);
	220	return 0;
	221	}
	222
	223	skb_pull(skb, sizeof(struct udphdr));
	224	rcu_read_lock();
	225	b = rcu_dereference_rtnl(ub->bearer);
	226
	227	if (b) {
	228	tipc_rcv(sock_net(sk), skb, b);
	229	rcu_read_unlock();
	230	return 0;
	231	}
	232	rcu_read_unlock();
	233	kfree_skb(skb);
	234	return 0;
	235	}
	236
	237	static int enable_mcast(struct udp_bearer ub, struct udp_media_addr remote)
	238	{
	239	int err = 0;
	240	struct ip_mreqn mreqn;
	241	struct sock *sk = ub->ubsock->sk;
	242
	243	if (ntohs(remote->proto) == ETH_P_IP) {
	244	if (!ipv4_is_multicast(remote->ipv4.s_addr))
	245	return 0;
	246	mreqn.imr_multiaddr = remote->ipv4;
	247	mreqn.imr_ifindex = ub->ifindex;
54ff9ef3	248	err = ip_mc_join_group(sk, &mreqn);
446981e5	249	#if IS_ENABLED(CONFIG_IPV6)
d0f91938 EH	250	} else {
	251	if (!ipv6_addr_is_multicast(&remote->ipv6))
	252	return 0;
446981e5 MRL	253	err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
	254	&remote->ipv6);
	255	#endif
d0f91938 EH	256	}
	257	return err;
	258	}
	259
	260	/**
	261	* parse_options - build local/remote addresses from configuration
	262	* @attrs: netlink config data
	263	* @ub: UDP bearer instance
	264	* @local: local bearer IP address/port
	265	* @remote: peer or multicast IP/port
	266	*/
	267	static int parse_options(struct nlattr attrs[], struct udp_bearer ub,
	268	struct udp_media_addr *local,
	269	struct udp_media_addr *remote)
	270	{
	271	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
ddb37125	272	struct sockaddr_storage sa_local, sa_remote;
d0f91938 EH	273
	274	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
	275	goto err;
	276	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
	277	attrs[TIPC_NLA_BEARER_UDP_OPTS],
	278	tipc_nl_udp_policy))
	279	goto err;
	280	if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
ddb37125 RA	281	nla_memcpy(&sa_local, opts[TIPC_NLA_UDP_LOCAL],
	282	sizeof(sa_local));
	283	nla_memcpy(&sa_remote, opts[TIPC_NLA_UDP_REMOTE],
	284	sizeof(sa_remote));
d0f91938 EH	285	} else {
	286	err:
	287	pr_err("Invalid UDP bearer configuration");
	288	return -EINVAL;
	289	}
ddb37125	290	if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET) {
d0f91938 EH	291	struct sockaddr_in *ip4;
d0f91938 EH	292
ddb37125	293	ip4 = (struct sockaddr_in *)&sa_local;
d0f91938	294	local->proto = htons(ETH_P_IP);
bc3a334c	295	local->port = ip4->sin_port;
d0f91938 EH	296	local->ipv4.s_addr = ip4->sin_addr.s_addr;
d0f91938 EH	297
ddb37125	298	ip4 = (struct sockaddr_in *)&sa_remote;
d0f91938	299	remote->proto = htons(ETH_P_IP);
bc3a334c	300	remote->port = ip4->sin_port;
d0f91938 EH	301	remote->ipv4.s_addr = ip4->sin_addr.s_addr;
	302	return 0;
	303
	304	#if IS_ENABLED(CONFIG_IPV6)
ddb37125	305	} else if ((sa_local.ss_family & sa_remote.ss_family) == AF_INET6) {
34f65dbb	306	int atype;
d0f91938 EH	307	struct sockaddr_in6 *ip6;
d0f91938 EH	308
ddb37125	309	ip6 = (struct sockaddr_in6 *)&sa_local;
34f65dbb RA	310	atype = ipv6_addr_type(&ip6->sin6_addr);
	311	if (__ipv6_addr_needs_scope_id(atype) && !ip6->sin6_scope_id)
	312	return -EINVAL;
	313
d0f91938	314	local->proto = htons(ETH_P_IPV6);
bc3a334c	315	local->port = ip6->sin6_port;
ddb37125	316	memcpy(&local->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
d0f91938 EH	317	ub->ifindex = ip6->sin6_scope_id;
d0f91938 EH	318
ddb37125	319	ip6 = (struct sockaddr_in6 *)&sa_remote;
d0f91938	320	remote->proto = htons(ETH_P_IPV6);
bc3a334c	321	remote->port = ip6->sin6_port;
ddb37125	322	memcpy(&remote->ipv6, &ip6->sin6_addr, sizeof(struct in6_addr));
d0f91938 EH	323	return 0;
	324	#endif
	325	}
	326	return -EADDRNOTAVAIL;
	327	}
	328
	329	/**
	330	* tipc_udp_enable - callback to create a new udp bearer instance
	331	* @net: network namespace
	332	* @b: pointer to generic tipc_bearer
	333	* @attrs: netlink bearer configuration
	334	*
	335	* validate the bearer parameters and initialize the udp bearer
	336	* rtnl_lock should be held
	337	*/
	338	static int tipc_udp_enable(struct net net, struct tipc_bearer b,
	339	struct nlattr *attrs[])
	340	{
	341	int err = -EINVAL;
	342	struct udp_bearer *ub;
	343	struct udp_media_addr *remote;
	344	struct udp_media_addr local = {0};
	345	struct udp_port_cfg udp_conf = {0};
4fee6be8	346	struct udp_tunnel_sock_cfg tuncfg = {NULL};
d0f91938 EH	347
	348	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
	349	if (!ub)
	350	return -ENOMEM;
	351
	352	remote = (struct udp_media_addr *)&b->bcast_addr.value;
	353	memset(remote, 0, sizeof(struct udp_media_addr));
	354	err = parse_options(attrs, ub, &local, remote);
	355	if (err)
	356	goto err;
	357
	358	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
	359	b->bcast_addr.broadcast = 1;
	360	rcu_assign_pointer(b->media_ptr, ub);
	361	rcu_assign_pointer(ub->bearer, b);
	362	tipc_udp_media_addr_set(&b->addr, &local);
4fee6be8	363	if (local.proto == htons(ETH_P_IP)) {
d0f91938 EH	364	struct net_device *dev;
	365
	366	dev = __ip_dev_find(net, local.ipv4.s_addr, false);
	367	if (!dev) {
	368	err = -ENODEV;
	369	goto err;
	370	}
	371	udp_conf.family = AF_INET;
	372	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
	373	udp_conf.use_udp_checksums = false;
	374	ub->ifindex = dev->ifindex;
	375	b->mtu = dev->mtu - sizeof(struct iphdr)
	376	- sizeof(struct udphdr);
	377	#if IS_ENABLED(CONFIG_IPV6)
4fee6be8	378	} else if (local.proto == htons(ETH_P_IPV6)) {
d0f91938 EH	379	udp_conf.family = AF_INET6;
	380	udp_conf.use_udp6_tx_checksums = true;
	381	udp_conf.use_udp6_rx_checksums = true;
	382	udp_conf.local_ip6 = in6addr_any;
	383	b->mtu = 1280;
	384	#endif
	385	} else {
	386	err = -EAFNOSUPPORT;
	387	goto err;
	388	}
bc3a334c	389	udp_conf.local_udp_port = local.port;
d0f91938 EH	390	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
	391	if (err)
	392	goto err;
	393	tuncfg.sk_user_data = ub;
	394	tuncfg.encap_type = 1;
	395	tuncfg.encap_rcv = tipc_udp_recv;
	396	tuncfg.encap_destroy = NULL;
	397	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
	398
a5de125d WY	399	err = enable_mcast(ub, remote);
a5de125d WY	400	if (err)
d0f91938 EH	401	goto err;
	402	return 0;
	403	err:
a5de125d WY	404	if (ub->ubsock)
a5de125d WY	405	udp_tunnel_sock_release(ub->ubsock);
d0f91938 EH	406	kfree(ub);
	407	return err;
	408	}
	409
	410	/* cleanup_bearer - break the socket/bearer association */
	411	static void cleanup_bearer(struct work_struct *work)
	412	{
	413	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
	414
	415	if (ub->ubsock)
	416	udp_tunnel_sock_release(ub->ubsock);
	417	synchronize_net();
	418	kfree(ub);
	419	}
	420
	421	/* tipc_udp_disable - detach bearer from socket */
	422	static void tipc_udp_disable(struct tipc_bearer *b)
	423	{
	424	struct udp_bearer *ub;
	425
	426	ub = rcu_dereference_rtnl(b->media_ptr);
	427	if (!ub) {
	428	pr_err("UDP bearer instance not found\n");
	429	return;
	430	}
	431	if (ub->ubsock)
	432	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
d0f91938 EH	433	RCU_INIT_POINTER(ub->bearer, NULL);
	434
	435	/* sock_release need to be done outside of rtnl lock */
	436	INIT_WORK(&ub->work, cleanup_bearer);
	437	schedule_work(&ub->work);
	438	}
	439
	440	struct tipc_media udp_media_info = {
	441	.send_msg = tipc_udp_send_msg,
	442	.enable_media = tipc_udp_enable,
	443	.disable_media = tipc_udp_disable,
	444	.addr2str = tipc_udp_addr2str,
	445	.addr2msg = tipc_udp_addr2msg,
	446	.msg2addr = tipc_udp_msg2addr,
	447	.priority = TIPC_DEF_LINK_PRI,
	448	.tolerance = TIPC_DEF_LINK_TOL,
	449	.window = TIPC_DEF_LINK_WIN,
	450	.type_id = TIPC_MEDIA_TYPE_UDP,
	451	.hwaddr_len = 0,
	452	.name = "udp"
	453	};