xref: /openbmc/linux/drivers/net/bareudp.c (revision b03afaa8)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Bareudp: UDP  tunnel encasulation for different Payload types like
3  * MPLS, NSH, IP, etc.
4  * Copyright (c) 2019 Nokia, Inc.
5  * Authors:  Martin Varghese, <martin.varghese@nokia.com>
6  */
7 
8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
9 
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/etherdevice.h>
13 #include <linux/hash.h>
14 #include <net/dst_metadata.h>
15 #include <net/gro_cells.h>
16 #include <net/rtnetlink.h>
17 #include <net/protocol.h>
18 #include <net/ip6_tunnel.h>
19 #include <net/ip_tunnels.h>
20 #include <net/udp_tunnel.h>
21 #include <net/bareudp.h>
22 
23 #define BAREUDP_BASE_HLEN sizeof(struct udphdr)
24 #define BAREUDP_IPV4_HLEN (sizeof(struct iphdr) + \
25 			   sizeof(struct udphdr))
26 #define BAREUDP_IPV6_HLEN (sizeof(struct ipv6hdr) + \
27 			   sizeof(struct udphdr))
28 
29 static bool log_ecn_error = true;
30 module_param(log_ecn_error, bool, 0644);
31 MODULE_PARM_DESC(log_ecn_error, "Log packets received with corrupted ECN");
32 
33 /* per-network namespace private data for this module */
34 
35 static unsigned int bareudp_net_id;
36 
37 struct bareudp_net {
38 	struct list_head        bareudp_list;
39 };
40 
41 /* Pseudo network device */
42 struct bareudp_dev {
43 	struct net         *net;        /* netns for packet i/o */
44 	struct net_device  *dev;        /* netdev for bareudp tunnel */
45 	__be16		   ethertype;
46 	__be16             port;
47 	u16	           sport_min;
48 	bool               multi_proto_mode;
49 	struct socket      __rcu *sock;
50 	struct list_head   next;        /* bareudp node  on namespace list */
51 	struct gro_cells   gro_cells;
52 };
53 
54 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
55 {
56 	struct metadata_dst *tun_dst = NULL;
57 	struct pcpu_sw_netstats *stats;
58 	struct bareudp_dev *bareudp;
59 	unsigned short family;
60 	unsigned int len;
61 	__be16 proto;
62 	void *oiph;
63 	int err;
64 
65 	bareudp = rcu_dereference_sk_user_data(sk);
66 	if (!bareudp)
67 		goto drop;
68 
69 	if (skb->protocol ==  htons(ETH_P_IP))
70 		family = AF_INET;
71 	else
72 		family = AF_INET6;
73 
74 	if (bareudp->ethertype == htons(ETH_P_IP)) {
75 		struct iphdr *iphdr;
76 
77 		iphdr = (struct iphdr *)(skb->data + BAREUDP_BASE_HLEN);
78 		if (iphdr->version == 4) {
79 			proto = bareudp->ethertype;
80 		} else if (bareudp->multi_proto_mode && (iphdr->version == 6)) {
81 			proto = htons(ETH_P_IPV6);
82 		} else {
83 			bareudp->dev->stats.rx_dropped++;
84 			goto drop;
85 		}
86 	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
87 		struct iphdr *tunnel_hdr;
88 
89 		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
90 		if (tunnel_hdr->version == 4) {
91 			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
92 				proto = bareudp->ethertype;
93 			} else if (bareudp->multi_proto_mode &&
94 				   ipv4_is_multicast(tunnel_hdr->daddr)) {
95 				proto = htons(ETH_P_MPLS_MC);
96 			} else {
97 				bareudp->dev->stats.rx_dropped++;
98 				goto drop;
99 			}
100 		} else {
101 			int addr_type;
102 			struct ipv6hdr *tunnel_hdr_v6;
103 
104 			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
105 			addr_type =
106 			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
107 			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
108 				proto = bareudp->ethertype;
109 			} else if (bareudp->multi_proto_mode &&
110 				   (addr_type & IPV6_ADDR_MULTICAST)) {
111 				proto = htons(ETH_P_MPLS_MC);
112 			} else {
113 				bareudp->dev->stats.rx_dropped++;
114 				goto drop;
115 			}
116 		}
117 	} else {
118 		proto = bareudp->ethertype;
119 	}
120 
121 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
122 				 proto,
123 				 !net_eq(bareudp->net,
124 				 dev_net(bareudp->dev)))) {
125 		bareudp->dev->stats.rx_dropped++;
126 		goto drop;
127 	}
128 	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
129 	if (!tun_dst) {
130 		bareudp->dev->stats.rx_dropped++;
131 		goto drop;
132 	}
133 	skb_dst_set(skb, &tun_dst->dst);
134 	skb->dev = bareudp->dev;
135 	oiph = skb_network_header(skb);
136 	skb_reset_network_header(skb);
137 
138 	if (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
139 		err = IP_ECN_decapsulate(oiph, skb);
140 	else
141 		err = IP6_ECN_decapsulate(oiph, skb);
142 
143 	if (unlikely(err)) {
144 		if (log_ecn_error) {
145 			if  (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
146 				net_info_ratelimited("non-ECT from %pI4 "
147 						     "with TOS=%#x\n",
148 						     &((struct iphdr *)oiph)->saddr,
149 						     ((struct iphdr *)oiph)->tos);
150 			else
151 				net_info_ratelimited("non-ECT from %pI6\n",
152 						     &((struct ipv6hdr *)oiph)->saddr);
153 		}
154 		if (err > 1) {
155 			++bareudp->dev->stats.rx_frame_errors;
156 			++bareudp->dev->stats.rx_errors;
157 			goto drop;
158 		}
159 	}
160 
161 	len = skb->len;
162 	err = gro_cells_receive(&bareudp->gro_cells, skb);
163 	if (likely(err == NET_RX_SUCCESS)) {
164 		stats = this_cpu_ptr(bareudp->dev->tstats);
165 		u64_stats_update_begin(&stats->syncp);
166 		stats->rx_packets++;
167 		stats->rx_bytes += len;
168 		u64_stats_update_end(&stats->syncp);
169 	}
170 	return 0;
171 drop:
172 	/* Consume bad packet */
173 	kfree_skb(skb);
174 
175 	return 0;
176 }
177 
178 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
179 {
180 	return 0;
181 }
182 
183 static int bareudp_init(struct net_device *dev)
184 {
185 	struct bareudp_dev *bareudp = netdev_priv(dev);
186 	int err;
187 
188 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
189 	if (!dev->tstats)
190 		return -ENOMEM;
191 
192 	err = gro_cells_init(&bareudp->gro_cells, dev);
193 	if (err) {
194 		free_percpu(dev->tstats);
195 		return err;
196 	}
197 	return 0;
198 }
199 
200 static void bareudp_uninit(struct net_device *dev)
201 {
202 	struct bareudp_dev *bareudp = netdev_priv(dev);
203 
204 	gro_cells_destroy(&bareudp->gro_cells);
205 	free_percpu(dev->tstats);
206 }
207 
208 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
209 {
210 	struct udp_port_cfg udp_conf;
211 	struct socket *sock;
212 	int err;
213 
214 	memset(&udp_conf, 0, sizeof(udp_conf));
215 #if IS_ENABLED(CONFIG_IPV6)
216 	udp_conf.family = AF_INET6;
217 #else
218 	udp_conf.family = AF_INET;
219 #endif
220 	udp_conf.local_udp_port = port;
221 	/* Open UDP socket */
222 	err = udp_sock_create(net, &udp_conf, &sock);
223 	if (err < 0)
224 		return ERR_PTR(err);
225 
226 	return sock;
227 }
228 
229 /* Create new listen socket if needed */
230 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
231 {
232 	struct udp_tunnel_sock_cfg tunnel_cfg;
233 	struct socket *sock;
234 
235 	sock = bareudp_create_sock(bareudp->net, port);
236 	if (IS_ERR(sock))
237 		return PTR_ERR(sock);
238 
239 	/* Mark socket as an encapsulation socket */
240 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
241 	tunnel_cfg.sk_user_data = bareudp;
242 	tunnel_cfg.encap_type = 1;
243 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
244 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
245 	tunnel_cfg.encap_destroy = NULL;
246 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
247 
248 	/* As the setup_udp_tunnel_sock does not call udp_encap_enable if the
249 	 * socket type is v6 an explicit call to udp_encap_enable is needed.
250 	 */
251 	if (sock->sk->sk_family == AF_INET6)
252 		udp_encap_enable();
253 
254 	rcu_assign_pointer(bareudp->sock, sock);
255 	return 0;
256 }
257 
258 static int bareudp_open(struct net_device *dev)
259 {
260 	struct bareudp_dev *bareudp = netdev_priv(dev);
261 	int ret = 0;
262 
263 	ret =  bareudp_socket_create(bareudp, bareudp->port);
264 	return ret;
265 }
266 
267 static void bareudp_sock_release(struct bareudp_dev *bareudp)
268 {
269 	struct socket *sock;
270 
271 	sock = bareudp->sock;
272 	rcu_assign_pointer(bareudp->sock, NULL);
273 	synchronize_net();
274 	udp_tunnel_sock_release(sock);
275 }
276 
277 static int bareudp_stop(struct net_device *dev)
278 {
279 	struct bareudp_dev *bareudp = netdev_priv(dev);
280 
281 	bareudp_sock_release(bareudp);
282 	return 0;
283 }
284 
285 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
286 			    struct bareudp_dev *bareudp,
287 			    const struct ip_tunnel_info *info)
288 {
289 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
290 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
291 	struct socket *sock = rcu_dereference(bareudp->sock);
292 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
293 	const struct ip_tunnel_key *key = &info->key;
294 	struct rtable *rt;
295 	__be16 sport, df;
296 	int min_headroom;
297 	__u8 tos, ttl;
298 	__be32 saddr;
299 	int err;
300 
301 	if (!sock)
302 		return -ESHUTDOWN;
303 
304 	rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr, info,
305 				    IPPROTO_UDP, use_cache);
306 
307 	if (IS_ERR(rt))
308 		return PTR_ERR(rt);
309 
310 	skb_tunnel_check_pmtu(skb, &rt->dst,
311 			      BAREUDP_IPV4_HLEN + info->options_len);
312 
313 	sport = udp_flow_src_port(bareudp->net, skb,
314 				  bareudp->sport_min, USHRT_MAX,
315 				  true);
316 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
317 	ttl = key->ttl;
318 	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
319 	skb_scrub_packet(skb, xnet);
320 
321 	err = -ENOSPC;
322 	if (!skb_pull(skb, skb_network_offset(skb)))
323 		goto free_dst;
324 
325 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
326 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
327 
328 	err = skb_cow_head(skb, min_headroom);
329 	if (unlikely(err))
330 		goto free_dst;
331 
332 	err = udp_tunnel_handle_offloads(skb, udp_sum);
333 	if (err)
334 		goto free_dst;
335 
336 	skb_set_inner_protocol(skb, bareudp->ethertype);
337 	udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
338 			    tos, ttl, df, sport, bareudp->port,
339 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
340 			    !(info->key.tun_flags & TUNNEL_CSUM));
341 	return 0;
342 
343 free_dst:
344 	dst_release(&rt->dst);
345 	return err;
346 }
347 
348 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
349 			     struct bareudp_dev *bareudp,
350 			     const struct ip_tunnel_info *info)
351 {
352 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
353 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
354 	struct socket *sock  = rcu_dereference(bareudp->sock);
355 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
356 	const struct ip_tunnel_key *key = &info->key;
357 	struct dst_entry *dst = NULL;
358 	struct in6_addr saddr, daddr;
359 	int min_headroom;
360 	__u8 prio, ttl;
361 	__be16 sport;
362 	int err;
363 
364 	if (!sock)
365 		return -ESHUTDOWN;
366 
367 	dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock, &saddr, info,
368 				    IPPROTO_UDP, use_cache);
369 	if (IS_ERR(dst))
370 		return PTR_ERR(dst);
371 
372 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len);
373 
374 	sport = udp_flow_src_port(bareudp->net, skb,
375 				  bareudp->sport_min, USHRT_MAX,
376 				  true);
377 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
378 	ttl = key->ttl;
379 
380 	skb_scrub_packet(skb, xnet);
381 
382 	err = -ENOSPC;
383 	if (!skb_pull(skb, skb_network_offset(skb)))
384 		goto free_dst;
385 
386 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
387 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
388 
389 	err = skb_cow_head(skb, min_headroom);
390 	if (unlikely(err))
391 		goto free_dst;
392 
393 	err = udp_tunnel_handle_offloads(skb, udp_sum);
394 	if (err)
395 		goto free_dst;
396 
397 	daddr = info->key.u.ipv6.dst;
398 	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
399 			     &saddr, &daddr, prio, ttl,
400 			     info->key.label, sport, bareudp->port,
401 			     !(info->key.tun_flags & TUNNEL_CSUM));
402 	return 0;
403 
404 free_dst:
405 	dst_release(dst);
406 	return err;
407 }
408 
409 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
410 {
411 	struct bareudp_dev *bareudp = netdev_priv(dev);
412 	struct ip_tunnel_info *info = NULL;
413 	int err;
414 
415 	if (skb->protocol != bareudp->ethertype) {
416 		if (!bareudp->multi_proto_mode ||
417 		    (skb->protocol !=  htons(ETH_P_MPLS_MC) &&
418 		     skb->protocol !=  htons(ETH_P_IPV6))) {
419 			err = -EINVAL;
420 			goto tx_error;
421 		}
422 	}
423 
424 	info = skb_tunnel_info(skb);
425 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
426 		err = -EINVAL;
427 		goto tx_error;
428 	}
429 
430 	rcu_read_lock();
431 	if (IS_ENABLED(CONFIG_IPV6) && info->mode & IP_TUNNEL_INFO_IPV6)
432 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
433 	else
434 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
435 
436 	rcu_read_unlock();
437 
438 	if (likely(!err))
439 		return NETDEV_TX_OK;
440 tx_error:
441 	dev_kfree_skb(skb);
442 
443 	if (err == -ELOOP)
444 		dev->stats.collisions++;
445 	else if (err == -ENETUNREACH)
446 		dev->stats.tx_carrier_errors++;
447 
448 	dev->stats.tx_errors++;
449 	return NETDEV_TX_OK;
450 }
451 
452 static int bareudp_fill_metadata_dst(struct net_device *dev,
453 				     struct sk_buff *skb)
454 {
455 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
456 	struct bareudp_dev *bareudp = netdev_priv(dev);
457 	bool use_cache;
458 
459 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
460 
461 	if (!IS_ENABLED(CONFIG_IPV6) || ip_tunnel_info_af(info) == AF_INET) {
462 		struct rtable *rt;
463 		__be32 saddr;
464 
465 		rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr,
466 					    info, IPPROTO_UDP, use_cache);
467 		if (IS_ERR(rt))
468 			return PTR_ERR(rt);
469 
470 		ip_rt_put(rt);
471 		info->key.u.ipv4.src = saddr;
472 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
473 		struct dst_entry *dst;
474 		struct in6_addr saddr;
475 		struct socket *sock = rcu_dereference(bareudp->sock);
476 
477 		dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock,
478 					    &saddr, info, IPPROTO_UDP,
479 					    use_cache);
480 		if (IS_ERR(dst))
481 			return PTR_ERR(dst);
482 
483 		dst_release(dst);
484 		info->key.u.ipv6.src = saddr;
485 	} else {
486 		return -EINVAL;
487 	}
488 
489 	info->key.tp_src = udp_flow_src_port(bareudp->net, skb,
490 					     bareudp->sport_min,
491 			USHRT_MAX, true);
492 	info->key.tp_dst = bareudp->port;
493 	return 0;
494 }
495 
496 static const struct net_device_ops bareudp_netdev_ops = {
497 	.ndo_init               = bareudp_init,
498 	.ndo_uninit             = bareudp_uninit,
499 	.ndo_open               = bareudp_open,
500 	.ndo_stop               = bareudp_stop,
501 	.ndo_start_xmit         = bareudp_xmit,
502 	.ndo_get_stats64        = ip_tunnel_get_stats64,
503 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
504 };
505 
506 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
507 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
508 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
509 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
510 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
511 };
512 
513 /* Info for udev, that this is a virtual tunnel endpoint */
514 static struct device_type bareudp_type = {
515 	.name = "bareudp",
516 };
517 
518 /* Initialize the device structure. */
519 static void bareudp_setup(struct net_device *dev)
520 {
521 	dev->netdev_ops = &bareudp_netdev_ops;
522 	dev->needs_free_netdev = true;
523 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
524 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
525 	dev->features    |= NETIF_F_RXCSUM;
526 	dev->features    |= NETIF_F_GSO_SOFTWARE;
527 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
528 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
529 	dev->hard_header_len = 0;
530 	dev->addr_len = 0;
531 	dev->mtu = ETH_DATA_LEN;
532 	dev->min_mtu = IPV4_MIN_MTU;
533 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
534 	dev->type = ARPHRD_NONE;
535 	netif_keep_dst(dev);
536 	dev->priv_flags |= IFF_NO_QUEUE;
537 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
538 }
539 
540 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
541 			    struct netlink_ext_ack *extack)
542 {
543 	if (!data) {
544 		NL_SET_ERR_MSG(extack,
545 			       "Not enough attributes provided to perform the operation");
546 		return -EINVAL;
547 	}
548 	return 0;
549 }
550 
551 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
552 			struct netlink_ext_ack *extack)
553 {
554 	memset(conf, 0, sizeof(*conf));
555 
556 	if (!data[IFLA_BAREUDP_PORT]) {
557 		NL_SET_ERR_MSG(extack, "port not specified");
558 		return -EINVAL;
559 	}
560 	if (!data[IFLA_BAREUDP_ETHERTYPE]) {
561 		NL_SET_ERR_MSG(extack, "ethertype not specified");
562 		return -EINVAL;
563 	}
564 
565 	if (data[IFLA_BAREUDP_PORT])
566 		conf->port =  nla_get_u16(data[IFLA_BAREUDP_PORT]);
567 
568 	if (data[IFLA_BAREUDP_ETHERTYPE])
569 		conf->ethertype =  nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
570 
571 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
572 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
573 
574 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
575 		conf->multi_proto_mode = true;
576 
577 	return 0;
578 }
579 
580 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
581 					    const struct bareudp_conf *conf)
582 {
583 	struct bareudp_dev *bareudp, *t = NULL;
584 
585 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
586 		if (conf->port == bareudp->port)
587 			t = bareudp;
588 	}
589 	return t;
590 }
591 
592 static int bareudp_configure(struct net *net, struct net_device *dev,
593 			     struct bareudp_conf *conf)
594 {
595 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
596 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
597 	int err;
598 
599 	bareudp->net = net;
600 	bareudp->dev = dev;
601 	t = bareudp_find_dev(bn, conf);
602 	if (t)
603 		return -EBUSY;
604 
605 	if (conf->multi_proto_mode &&
606 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
607 	     conf->ethertype != htons(ETH_P_IP)))
608 		return -EINVAL;
609 
610 	bareudp->port = conf->port;
611 	bareudp->ethertype = conf->ethertype;
612 	bareudp->sport_min = conf->sport_min;
613 	bareudp->multi_proto_mode = conf->multi_proto_mode;
614 
615 	err = register_netdevice(dev);
616 	if (err)
617 		return err;
618 
619 	list_add(&bareudp->next, &bn->bareudp_list);
620 	return 0;
621 }
622 
623 static int bareudp_link_config(struct net_device *dev,
624 			       struct nlattr *tb[])
625 {
626 	int err;
627 
628 	if (tb[IFLA_MTU]) {
629 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
630 		if (err)
631 			return err;
632 	}
633 	return 0;
634 }
635 
636 static int bareudp_newlink(struct net *net, struct net_device *dev,
637 			   struct nlattr *tb[], struct nlattr *data[],
638 			   struct netlink_ext_ack *extack)
639 {
640 	struct bareudp_conf conf;
641 	int err;
642 
643 	err = bareudp2info(data, &conf, extack);
644 	if (err)
645 		return err;
646 
647 	err = bareudp_configure(net, dev, &conf);
648 	if (err)
649 		return err;
650 
651 	err = bareudp_link_config(dev, tb);
652 	if (err)
653 		return err;
654 
655 	return 0;
656 }
657 
658 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
659 {
660 	struct bareudp_dev *bareudp = netdev_priv(dev);
661 
662 	list_del(&bareudp->next);
663 	unregister_netdevice_queue(dev, head);
664 }
665 
666 static size_t bareudp_get_size(const struct net_device *dev)
667 {
668 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
669 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
670 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
671 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
672 		0;
673 }
674 
675 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
676 {
677 	struct bareudp_dev *bareudp = netdev_priv(dev);
678 
679 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
680 		goto nla_put_failure;
681 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
682 		goto nla_put_failure;
683 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
684 		goto nla_put_failure;
685 	if (bareudp->multi_proto_mode &&
686 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
687 		goto nla_put_failure;
688 
689 	return 0;
690 
691 nla_put_failure:
692 	return -EMSGSIZE;
693 }
694 
695 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
696 	.kind           = "bareudp",
697 	.maxtype        = IFLA_BAREUDP_MAX,
698 	.policy         = bareudp_policy,
699 	.priv_size      = sizeof(struct bareudp_dev),
700 	.setup          = bareudp_setup,
701 	.validate       = bareudp_validate,
702 	.newlink        = bareudp_newlink,
703 	.dellink        = bareudp_dellink,
704 	.get_size       = bareudp_get_size,
705 	.fill_info      = bareudp_fill_info,
706 };
707 
708 struct net_device *bareudp_dev_create(struct net *net, const char *name,
709 				      u8 name_assign_type,
710 				      struct bareudp_conf *conf)
711 {
712 	struct nlattr *tb[IFLA_MAX + 1];
713 	struct net_device *dev;
714 	LIST_HEAD(list_kill);
715 	int err;
716 
717 	memset(tb, 0, sizeof(tb));
718 	dev = rtnl_create_link(net, name, name_assign_type,
719 			       &bareudp_link_ops, tb, NULL);
720 	if (IS_ERR(dev))
721 		return dev;
722 
723 	err = bareudp_configure(net, dev, conf);
724 	if (err) {
725 		free_netdev(dev);
726 		return ERR_PTR(err);
727 	}
728 	err = dev_set_mtu(dev, IP_MAX_MTU - BAREUDP_BASE_HLEN);
729 	if (err)
730 		goto err;
731 
732 	err = rtnl_configure_link(dev, NULL);
733 	if (err < 0)
734 		goto err;
735 
736 	return dev;
737 err:
738 	bareudp_dellink(dev, &list_kill);
739 	unregister_netdevice_many(&list_kill);
740 	return ERR_PTR(err);
741 }
742 EXPORT_SYMBOL_GPL(bareudp_dev_create);
743 
744 static __net_init int bareudp_init_net(struct net *net)
745 {
746 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
747 
748 	INIT_LIST_HEAD(&bn->bareudp_list);
749 	return 0;
750 }
751 
752 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
753 {
754 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
755 	struct bareudp_dev *bareudp, *next;
756 
757 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
758 		unregister_netdevice_queue(bareudp->dev, head);
759 }
760 
761 static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
762 {
763 	struct net *net;
764 	LIST_HEAD(list);
765 
766 	rtnl_lock();
767 	list_for_each_entry(net, net_list, exit_list)
768 		bareudp_destroy_tunnels(net, &list);
769 
770 	/* unregister the devices gathered above */
771 	unregister_netdevice_many(&list);
772 	rtnl_unlock();
773 }
774 
775 static struct pernet_operations bareudp_net_ops = {
776 	.init = bareudp_init_net,
777 	.exit_batch = bareudp_exit_batch_net,
778 	.id   = &bareudp_net_id,
779 	.size = sizeof(struct bareudp_net),
780 };
781 
782 static int __init bareudp_init_module(void)
783 {
784 	int rc;
785 
786 	rc = register_pernet_subsys(&bareudp_net_ops);
787 	if (rc)
788 		goto out1;
789 
790 	rc = rtnl_link_register(&bareudp_link_ops);
791 	if (rc)
792 		goto out2;
793 
794 	return 0;
795 out2:
796 	unregister_pernet_subsys(&bareudp_net_ops);
797 out1:
798 	return rc;
799 }
800 late_initcall(bareudp_init_module);
801 
802 static void __exit bareudp_cleanup_module(void)
803 {
804 	rtnl_link_unregister(&bareudp_link_ops);
805 	unregister_pernet_subsys(&bareudp_net_ops);
806 }
807 module_exit(bareudp_cleanup_module);
808 
809 MODULE_ALIAS_RTNL_LINK("bareudp");
810 MODULE_LICENSE("GPL");
811 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
812 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
813