tipc: add ip/udp media type

The ip/udp bearer can be configured in a point-to-point
mode by specifying both local and remote ip/hostname,
or it can be enabled in multicast mode, where links are
established to all tipc nodes that have joined the same
multicast group. The multicast IP address is generated
based on the TIPC network ID, but can be overridden by
using another multicast address as remote ip.

Signed-off-by: Erik Hugne <erik.hugne@ericsson.com>
Reviewed-by: Jon Maloy <jon.maloy@ericsson.com>
Reviewed-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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 000000000000..0d10001db40d
--- /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"
+};