[deliverable/linux.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"

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

#define UDP_MIN_HEADROOM        28

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 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;
		}
		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->udp_port,
				    dst->udp_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, src->udp_port,
					   dst->udp_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]) {
		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(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"
	51
	52	/* IANA assigned UDP port */
	53	#define UDP_PORT_DEFAULT 6118
	54
e5356794 JPM	55	#define UDP_MIN_HEADROOM 28
e5356794 JPM	56
d0f91938 EH	57	static const struct nla_policy tipc_nl_udp_policy[TIPC_NLA_UDP_MAX + 1] = {
	58	[TIPC_NLA_UDP_UNSPEC] = {.type = NLA_UNSPEC},
	59	[TIPC_NLA_UDP_LOCAL] = {.type = NLA_BINARY,
	60	.len = sizeof(struct sockaddr_storage)},
	61	[TIPC_NLA_UDP_REMOTE] = {.type = NLA_BINARY,
	62	.len = sizeof(struct sockaddr_storage)},
	63	};
	64
	65	/**
	66	* struct udp_media_addr - IP/UDP addressing information
	67	*
	68	* This is the bearer level originating address used in neighbor discovery
	69	* messages, and all fields should be in network byte order
	70	*/
	71	struct udp_media_addr {
	72	__be16 proto;
	73	__be16 udp_port;
	74	union {
	75	struct in_addr ipv4;
	76	struct in6_addr ipv6;
	77	};
	78	};
	79
	80	/**
	81	* struct udp_bearer - ip/udp bearer data structure
	82	* @bearer: associated generic tipc bearer
	83	* @ubsock: bearer associated socket
	84	* @ifindex: local address scope
	85	* @work: used to schedule deferred work on a bearer
	86	*/
	87	struct udp_bearer {
	88	struct tipc_bearer __rcu *bearer;
	89	struct socket *ubsock;
	90	u32 ifindex;
	91	struct work_struct work;
	92	};
	93
	94	/* udp_media_addr_set - convert a ip/udp address to a TIPC media address */
	95	static void tipc_udp_media_addr_set(struct tipc_media_addr *addr,
	96	struct udp_media_addr *ua)
	97	{
	98	memset(addr, 0, sizeof(struct tipc_media_addr));
	99	addr->media_id = TIPC_MEDIA_TYPE_UDP;
	100	memcpy(addr->value, ua, sizeof(struct udp_media_addr));
	101	if (ntohs(ua->proto) == ETH_P_IP) {
	102	if (ipv4_is_multicast(ua->ipv4.s_addr))
	103	addr->broadcast = 1;
	104	} else if (ntohs(ua->proto) == ETH_P_IPV6) {
	105	if (ipv6_addr_type(&ua->ipv6) & IPV6_ADDR_MULTICAST)
	106	addr->broadcast = 1;
	107	} else {
	108	pr_err("Invalid UDP media address\n");
	109	}
	110	}
	111
	112	/* tipc_udp_addr2str - convert ip/udp address to string */
	113	static int tipc_udp_addr2str(struct tipc_media_addr a, char buf, int size)
	114	{
	115	struct udp_media_addr ua = (struct udp_media_addr )&a->value;
	116
	117	if (ntohs(ua->proto) == ETH_P_IP)
	118	snprintf(buf, size, "%pI4:%u", &ua->ipv4, ntohs(ua->udp_port));
	119	else if (ntohs(ua->proto) == ETH_P_IPV6)
	120	snprintf(buf, size, "%pI6:%u", &ua->ipv6, ntohs(ua->udp_port));
121	else
122	pr_err("Invalid UDP media address\n");
123	return 0;
124	}
125
126	/* tipc_udp_msg2addr - extract an ip/udp address from a TIPC ndisc message */
127	static int tipc_udp_msg2addr(struct tipc_bearer b, struct tipc_media_addr a,
128	char *msg)
129	{
130	struct udp_media_addr *ua;
131
132	ua = (struct udp_media_addr *) (msg + TIPC_MEDIA_ADDR_OFFSET);
133	if (msg[TIPC_MEDIA_TYPE_OFFSET] != TIPC_MEDIA_TYPE_UDP)
134	return -EINVAL;
135	tipc_udp_media_addr_set(a, ua);
136	return 0;
137	}
138
139	/* tipc_udp_addr2msg - write an ip/udp address to a TIPC ndisc message */
140	static int tipc_udp_addr2msg(char msg, struct tipc_media_addr a)
141	{
142	memset(msg, 0, TIPC_MEDIA_INFO_SIZE);
143	msg[TIPC_MEDIA_TYPE_OFFSET] = TIPC_MEDIA_TYPE_UDP;
144	memcpy(msg + TIPC_MEDIA_ADDR_OFFSET, a->value,
145	sizeof(struct udp_media_addr));
146	return 0;
147	}
148
149	/* tipc_send_msg - enqueue a send request */
150	static int tipc_udp_send_msg(struct net net, struct sk_buff skb,
151	struct tipc_bearer *b,
152	struct tipc_media_addr *dest)
153	{
154	int ttl, err = 0;
155	struct udp_bearer *ub;
156	struct udp_media_addr dst = (struct udp_media_addr )&dest->value;
157	struct udp_media_addr src = (struct udp_media_addr )&b->addr.value;
d0f91938 EH	158	struct rtable *rt;
d0f91938 EH	159
7098356b YX	160	if (skb_headroom(skb) < UDP_MIN_HEADROOM) {
	161	err = pskb_expand_head(skb, UDP_MIN_HEADROOM, 0, GFP_ATOMIC);
	162	if (err)
	163	goto tx_error;
	164	}
e5356794	165
7214bcf8	166	skb_set_inner_protocol(skb, htons(ETH_P_TIPC));
d0f91938 EH	167	ub = rcu_dereference_rtnl(b->media_ptr);
	168	if (!ub) {
	169	err = -ENODEV;
	170	goto tx_error;
	171	}
4fee6be8	172	if (dst->proto == htons(ETH_P_IP)) {
d0f91938 EH	173	struct flowi4 fl = {
	174	.daddr = dst->ipv4.s_addr,
	175	.saddr = src->ipv4.s_addr,
7214bcf8	176	.flowi4_mark = skb->mark,
d0f91938 EH	177	.flowi4_proto = IPPROTO_UDP
	178	};
	179	rt = ip_route_output_key(net, &fl);
	180	if (IS_ERR(rt)) {
	181	err = PTR_ERR(rt);
	182	goto tx_error;
	183	}
	184	ttl = ip4_dst_hoplimit(&rt->dst);
039f5062 PS	185	udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
	186	dst->ipv4.s_addr, 0, ttl, 0, src->udp_port,
	187	dst->udp_port, false, true);
d0f91938 EH	188	#if IS_ENABLED(CONFIG_IPV6)
	189	} else {
	190	struct dst_entry *ndst;
	191	struct flowi6 fl6 = {
	192	.flowi6_oif = ub->ifindex,
	193	.daddr = dst->ipv6,
	194	.saddr = src->ipv6,
	195	.flowi6_proto = IPPROTO_UDP
	196	};
343d60aa RP	197	err = ipv6_stub->ipv6_dst_lookup(net, ub->ubsock->sk, &ndst,
343d60aa RP	198	&fl6);
d0f91938 EH	199	if (err)
	200	goto tx_error;
	201	ttl = ip6_dst_hoplimit(ndst);
7214bcf8	202	err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
79b16aad	203	ndst->dev, &src->ipv6,
d0f91938 EH	204	&dst->ipv6, 0, ttl, src->udp_port,
	205	dst->udp_port, false);
	206	#endif
	207	}
	208	return err;
	209
	210	tx_error:
7214bcf8	211	kfree_skb(skb);
d0f91938 EH	212	return err;
	213	}
	214
	215	/* tipc_udp_recv - read data from bearer socket */
	216	static int tipc_udp_recv(struct sock sk, struct sk_buff skb)
	217	{
	218	struct udp_bearer *ub;
	219	struct tipc_bearer *b;
	220
	221	ub = rcu_dereference_sk_user_data(sk);
	222	if (!ub) {
	223	pr_err_ratelimited("Failed to get UDP bearer reference");
	224	kfree_skb(skb);
	225	return 0;
	226	}
	227
	228	skb_pull(skb, sizeof(struct udphdr));
	229	rcu_read_lock();
	230	b = rcu_dereference_rtnl(ub->bearer);
	231
	232	if (b) {
	233	tipc_rcv(sock_net(sk), skb, b);
	234	rcu_read_unlock();
	235	return 0;
	236	}
	237	rcu_read_unlock();
	238	kfree_skb(skb);
	239	return 0;
	240	}
	241
	242	static int enable_mcast(struct udp_bearer ub, struct udp_media_addr remote)
	243	{
	244	int err = 0;
	245	struct ip_mreqn mreqn;
	246	struct sock *sk = ub->ubsock->sk;
	247
	248	if (ntohs(remote->proto) == ETH_P_IP) {
	249	if (!ipv4_is_multicast(remote->ipv4.s_addr))
	250	return 0;
	251	mreqn.imr_multiaddr = remote->ipv4;
	252	mreqn.imr_ifindex = ub->ifindex;
54ff9ef3	253	err = ip_mc_join_group(sk, &mreqn);
446981e5	254	#if IS_ENABLED(CONFIG_IPV6)
d0f91938 EH	255	} else {
	256	if (!ipv6_addr_is_multicast(&remote->ipv6))
	257	return 0;
446981e5 MRL	258	err = ipv6_stub->ipv6_sock_mc_join(sk, ub->ifindex,
	259	&remote->ipv6);
	260	#endif
d0f91938 EH	261	}
	262	return err;
	263	}
	264
	265	/**
	266	* parse_options - build local/remote addresses from configuration
	267	* @attrs: netlink config data
	268	* @ub: UDP bearer instance
	269	* @local: local bearer IP address/port
	270	* @remote: peer or multicast IP/port
	271	*/
	272	static int parse_options(struct nlattr attrs[], struct udp_bearer ub,
	273	struct udp_media_addr *local,
	274	struct udp_media_addr *remote)
	275	{
	276	struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
	277	struct sockaddr_storage sa_local, sa_remote;
	278
	279	if (!attrs[TIPC_NLA_BEARER_UDP_OPTS])
	280	goto err;
	281	if (nla_parse_nested(opts, TIPC_NLA_UDP_MAX,
	282	attrs[TIPC_NLA_BEARER_UDP_OPTS],
	283	tipc_nl_udp_policy))
	284	goto err;
	285	if (opts[TIPC_NLA_UDP_LOCAL] && opts[TIPC_NLA_UDP_REMOTE]) {
	286	sa_local = nla_data(opts[TIPC_NLA_UDP_LOCAL]);
	287	sa_remote = nla_data(opts[TIPC_NLA_UDP_REMOTE]);
	288	} else {
	289	err:
	290	pr_err("Invalid UDP bearer configuration");
	291	return -EINVAL;
	292	}
	293	if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET) {
	294	struct sockaddr_in *ip4;
	295
	296	ip4 = (struct sockaddr_in *)sa_local;
	297	local->proto = htons(ETH_P_IP);
	298	local->udp_port = ip4->sin_port;
	299	local->ipv4.s_addr = ip4->sin_addr.s_addr;
	300
	301	ip4 = (struct sockaddr_in *)sa_remote;
	302	remote->proto = htons(ETH_P_IP);
	303	remote->udp_port = ip4->sin_port;
	304	remote->ipv4.s_addr = ip4->sin_addr.s_addr;
	305	return 0;
	306
	307	#if IS_ENABLED(CONFIG_IPV6)
	308	} else if ((sa_local->ss_family & sa_remote->ss_family) == AF_INET6) {
	309	struct sockaddr_in6 *ip6;
	310
	311	ip6 = (struct sockaddr_in6 *)sa_local;
	312	local->proto = htons(ETH_P_IPV6);
	313	local->udp_port = ip6->sin6_port;
	314	local->ipv6 = ip6->sin6_addr;
	315	ub->ifindex = ip6->sin6_scope_id;
	316
	317	ip6 = (struct sockaddr_in6 *)sa_remote;
	318	remote->proto = htons(ETH_P_IPV6);
	319	remote->udp_port = ip6->sin6_port;
	320	remote->ipv6 = ip6->sin6_addr;
	321	return 0;
	322	#endif
	323	}
	324	return -EADDRNOTAVAIL;
325	}
326
327	/**
328	* tipc_udp_enable - callback to create a new udp bearer instance
329	* @net: network namespace
330	* @b: pointer to generic tipc_bearer
331	* @attrs: netlink bearer configuration
332	*
333	* validate the bearer parameters and initialize the udp bearer
334	* rtnl_lock should be held
335	*/
336	static int tipc_udp_enable(struct net net, struct tipc_bearer b,
337	struct nlattr *attrs[])
338	{
339	int err = -EINVAL;
340	struct udp_bearer *ub;
341	struct udp_media_addr *remote;
342	struct udp_media_addr local = {0};
343	struct udp_port_cfg udp_conf = {0};
4fee6be8	344	struct udp_tunnel_sock_cfg tuncfg = {NULL};
d0f91938 EH	345
	346	ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
	347	if (!ub)
	348	return -ENOMEM;
	349
	350	remote = (struct udp_media_addr *)&b->bcast_addr.value;
	351	memset(remote, 0, sizeof(struct udp_media_addr));
	352	err = parse_options(attrs, ub, &local, remote);
	353	if (err)
	354	goto err;
	355
	356	b->bcast_addr.media_id = TIPC_MEDIA_TYPE_UDP;
	357	b->bcast_addr.broadcast = 1;
	358	rcu_assign_pointer(b->media_ptr, ub);
	359	rcu_assign_pointer(ub->bearer, b);
	360	tipc_udp_media_addr_set(&b->addr, &local);
4fee6be8	361	if (local.proto == htons(ETH_P_IP)) {
d0f91938 EH	362	struct net_device *dev;
	363
	364	dev = __ip_dev_find(net, local.ipv4.s_addr, false);
	365	if (!dev) {
	366	err = -ENODEV;
	367	goto err;
	368	}
	369	udp_conf.family = AF_INET;
	370	udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
	371	udp_conf.use_udp_checksums = false;
	372	ub->ifindex = dev->ifindex;
	373	b->mtu = dev->mtu - sizeof(struct iphdr)
	374	- sizeof(struct udphdr);
	375	#if IS_ENABLED(CONFIG_IPV6)
4fee6be8	376	} else if (local.proto == htons(ETH_P_IPV6)) {
d0f91938 EH	377	udp_conf.family = AF_INET6;
	378	udp_conf.use_udp6_tx_checksums = true;
	379	udp_conf.use_udp6_rx_checksums = true;
	380	udp_conf.local_ip6 = in6addr_any;
	381	b->mtu = 1280;
	382	#endif
	383	} else {
	384	err = -EAFNOSUPPORT;
	385	goto err;
	386	}
	387	udp_conf.local_udp_port = local.udp_port;
	388	err = udp_sock_create(net, &udp_conf, &ub->ubsock);
	389	if (err)
	390	goto err;
	391	tuncfg.sk_user_data = ub;
	392	tuncfg.encap_type = 1;
	393	tuncfg.encap_rcv = tipc_udp_recv;
	394	tuncfg.encap_destroy = NULL;
	395	setup_udp_tunnel_sock(net, ub->ubsock, &tuncfg);
	396
	397	if (enable_mcast(ub, remote))
	398	goto err;
	399	return 0;
	400	err:
	401	kfree(ub);
	402	return err;
	403	}
	404
	405	/* cleanup_bearer - break the socket/bearer association */
	406	static void cleanup_bearer(struct work_struct *work)
	407	{
	408	struct udp_bearer *ub = container_of(work, struct udp_bearer, work);
	409
	410	if (ub->ubsock)
	411	udp_tunnel_sock_release(ub->ubsock);
	412	synchronize_net();
	413	kfree(ub);
	414	}
	415
	416	/* tipc_udp_disable - detach bearer from socket */
	417	static void tipc_udp_disable(struct tipc_bearer *b)
	418	{
	419	struct udp_bearer *ub;
	420
	421	ub = rcu_dereference_rtnl(b->media_ptr);
	422	if (!ub) {
	423	pr_err("UDP bearer instance not found\n");
	424	return;
	425	}
	426	if (ub->ubsock)
	427	sock_set_flag(ub->ubsock->sk, SOCK_DEAD);
d0f91938 EH	428	RCU_INIT_POINTER(ub->bearer, NULL);
	429
	430	/* sock_release need to be done outside of rtnl lock */
	431	INIT_WORK(&ub->work, cleanup_bearer);
	432	schedule_work(&ub->work);
	433	}
	434
	435	struct tipc_media udp_media_info = {
	436	.send_msg = tipc_udp_send_msg,
	437	.enable_media = tipc_udp_enable,
	438	.disable_media = tipc_udp_disable,
	439	.addr2str = tipc_udp_addr2str,
	440	.addr2msg = tipc_udp_addr2msg,
	441	.msg2addr = tipc_udp_msg2addr,
	442	.priority = TIPC_DEF_LINK_PRI,
	443	.tolerance = TIPC_DEF_LINK_TOL,
	444	.window = TIPC_DEF_LINK_WIN,
	445	.type_id = TIPC_MEDIA_TYPE_UDP,
	446	.hwaddr_len = 0,
	447	.name = "udp"
	448	};