1 files changed, 442 insertions, 0 deletions

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
new file mode 100644
index 0000000..0d10001
--- /dev/null
+++ b/net/tipc/udp_media.c
@@ -0,0 +1,442 @@
+/* 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 <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 (htons(dst->proto) == 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, 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 = ip6_dst_lookup(ub->ubsock->sk, &ndst, &fl6);
+		if (err)
+			goto tx_error;
+		ttl = ip6_dst_hoplimit(ndst);
+		err = udp_tunnel6_xmit_skb(ndst, 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);
+	} else {
+		if (!ipv6_addr_is_multicast(&remote->ipv6))
+			return 0;
+		err = __ipv6_sock_mc_join(sk, ub->ifindex, &remote->ipv6);
+	}
+	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 = {0};
+
+	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 (htons(local.proto) == 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 (htons(local.proto) == 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"
+};