xref: /linux/drivers/net/bareudp.c (revision 0678df8271820bcf8fb4f877129f05d68a237de4)
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 struct bareudp_conf {
42 	__be16 ethertype;
43 	__be16 port;
44 	u16 sport_min;
45 	bool multi_proto_mode;
46 };
47 
48 /* Pseudo network device */
49 struct bareudp_dev {
50 	struct net         *net;        /* netns for packet i/o */
51 	struct net_device  *dev;        /* netdev for bareudp tunnel */
52 	__be16		   ethertype;
53 	__be16             port;
54 	u16	           sport_min;
55 	bool               multi_proto_mode;
56 	struct socket      __rcu *sock;
57 	struct list_head   next;        /* bareudp node  on namespace list */
58 	struct gro_cells   gro_cells;
59 };
60 
61 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
62 {
63 	struct metadata_dst *tun_dst = NULL;
64 	struct bareudp_dev *bareudp;
65 	unsigned short family;
66 	unsigned int len;
67 	__be16 proto;
68 	void *oiph;
69 	int err;
70 
71 	bareudp = rcu_dereference_sk_user_data(sk);
72 	if (!bareudp)
73 		goto drop;
74 
75 	if (skb->protocol ==  htons(ETH_P_IP))
76 		family = AF_INET;
77 	else
78 		family = AF_INET6;
79 
80 	if (bareudp->ethertype == htons(ETH_P_IP)) {
81 		__u8 ipversion;
82 
83 		if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
84 				  sizeof(ipversion))) {
85 			bareudp->dev->stats.rx_dropped++;
86 			goto drop;
87 		}
88 		ipversion >>= 4;
89 
90 		if (ipversion == 4) {
91 			proto = htons(ETH_P_IP);
92 		} else if (ipversion == 6 && bareudp->multi_proto_mode) {
93 			proto = htons(ETH_P_IPV6);
94 		} else {
95 			bareudp->dev->stats.rx_dropped++;
96 			goto drop;
97 		}
98 	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
99 		struct iphdr *tunnel_hdr;
100 
101 		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
102 		if (tunnel_hdr->version == 4) {
103 			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
104 				proto = bareudp->ethertype;
105 			} else if (bareudp->multi_proto_mode &&
106 				   ipv4_is_multicast(tunnel_hdr->daddr)) {
107 				proto = htons(ETH_P_MPLS_MC);
108 			} else {
109 				bareudp->dev->stats.rx_dropped++;
110 				goto drop;
111 			}
112 		} else {
113 			int addr_type;
114 			struct ipv6hdr *tunnel_hdr_v6;
115 
116 			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
117 			addr_type =
118 			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
119 			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
120 				proto = bareudp->ethertype;
121 			} else if (bareudp->multi_proto_mode &&
122 				   (addr_type & IPV6_ADDR_MULTICAST)) {
123 				proto = htons(ETH_P_MPLS_MC);
124 			} else {
125 				bareudp->dev->stats.rx_dropped++;
126 				goto drop;
127 			}
128 		}
129 	} else {
130 		proto = bareudp->ethertype;
131 	}
132 
133 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
134 				 proto,
135 				 !net_eq(bareudp->net,
136 				 dev_net(bareudp->dev)))) {
137 		bareudp->dev->stats.rx_dropped++;
138 		goto drop;
139 	}
140 	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
141 	if (!tun_dst) {
142 		bareudp->dev->stats.rx_dropped++;
143 		goto drop;
144 	}
145 	skb_dst_set(skb, &tun_dst->dst);
146 	skb->dev = bareudp->dev;
147 	oiph = skb_network_header(skb);
148 	skb_reset_network_header(skb);
149 	skb_reset_mac_header(skb);
150 
151 	if (!ipv6_mod_enabled() || family == AF_INET)
152 		err = IP_ECN_decapsulate(oiph, skb);
153 	else
154 		err = IP6_ECN_decapsulate(oiph, skb);
155 
156 	if (unlikely(err)) {
157 		if (log_ecn_error) {
158 			if  (!ipv6_mod_enabled() || family == AF_INET)
159 				net_info_ratelimited("non-ECT from %pI4 "
160 						     "with TOS=%#x\n",
161 						     &((struct iphdr *)oiph)->saddr,
162 						     ((struct iphdr *)oiph)->tos);
163 			else
164 				net_info_ratelimited("non-ECT from %pI6\n",
165 						     &((struct ipv6hdr *)oiph)->saddr);
166 		}
167 		if (err > 1) {
168 			++bareudp->dev->stats.rx_frame_errors;
169 			++bareudp->dev->stats.rx_errors;
170 			goto drop;
171 		}
172 	}
173 
174 	len = skb->len;
175 	err = gro_cells_receive(&bareudp->gro_cells, skb);
176 	if (likely(err == NET_RX_SUCCESS))
177 		dev_sw_netstats_rx_add(bareudp->dev, len);
178 
179 	return 0;
180 drop:
181 	/* Consume bad packet */
182 	kfree_skb(skb);
183 
184 	return 0;
185 }
186 
187 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
188 {
189 	return 0;
190 }
191 
192 static int bareudp_init(struct net_device *dev)
193 {
194 	struct bareudp_dev *bareudp = netdev_priv(dev);
195 	int err;
196 
197 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
198 	if (!dev->tstats)
199 		return -ENOMEM;
200 
201 	err = gro_cells_init(&bareudp->gro_cells, dev);
202 	if (err) {
203 		free_percpu(dev->tstats);
204 		return err;
205 	}
206 	return 0;
207 }
208 
209 static void bareudp_uninit(struct net_device *dev)
210 {
211 	struct bareudp_dev *bareudp = netdev_priv(dev);
212 
213 	gro_cells_destroy(&bareudp->gro_cells);
214 	free_percpu(dev->tstats);
215 }
216 
217 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
218 {
219 	struct udp_port_cfg udp_conf;
220 	struct socket *sock;
221 	int err;
222 
223 	memset(&udp_conf, 0, sizeof(udp_conf));
224 
225 	if (ipv6_mod_enabled())
226 		udp_conf.family = AF_INET6;
227 	else
228 		udp_conf.family = AF_INET;
229 
230 	udp_conf.local_udp_port = port;
231 	/* Open UDP socket */
232 	err = udp_sock_create(net, &udp_conf, &sock);
233 	if (err < 0)
234 		return ERR_PTR(err);
235 
236 	udp_allow_gso(sock->sk);
237 	return sock;
238 }
239 
240 /* Create new listen socket if needed */
241 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
242 {
243 	struct udp_tunnel_sock_cfg tunnel_cfg;
244 	struct socket *sock;
245 
246 	sock = bareudp_create_sock(bareudp->net, port);
247 	if (IS_ERR(sock))
248 		return PTR_ERR(sock);
249 
250 	/* Mark socket as an encapsulation socket */
251 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
252 	tunnel_cfg.sk_user_data = bareudp;
253 	tunnel_cfg.encap_type = 1;
254 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
255 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
256 	tunnel_cfg.encap_destroy = NULL;
257 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
258 
259 	rcu_assign_pointer(bareudp->sock, sock);
260 	return 0;
261 }
262 
263 static int bareudp_open(struct net_device *dev)
264 {
265 	struct bareudp_dev *bareudp = netdev_priv(dev);
266 	int ret = 0;
267 
268 	ret =  bareudp_socket_create(bareudp, bareudp->port);
269 	return ret;
270 }
271 
272 static void bareudp_sock_release(struct bareudp_dev *bareudp)
273 {
274 	struct socket *sock;
275 
276 	sock = bareudp->sock;
277 	rcu_assign_pointer(bareudp->sock, NULL);
278 	synchronize_net();
279 	udp_tunnel_sock_release(sock);
280 }
281 
282 static int bareudp_stop(struct net_device *dev)
283 {
284 	struct bareudp_dev *bareudp = netdev_priv(dev);
285 
286 	bareudp_sock_release(bareudp);
287 	return 0;
288 }
289 
290 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
291 			    struct bareudp_dev *bareudp,
292 			    const struct ip_tunnel_info *info)
293 {
294 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
295 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
296 	struct socket *sock = rcu_dereference(bareudp->sock);
297 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
298 	const struct ip_tunnel_key *key = &info->key;
299 	struct rtable *rt;
300 	__be16 sport, df;
301 	int min_headroom;
302 	__u8 tos, ttl;
303 	__be32 saddr;
304 	int err;
305 
306 	if (!sock)
307 		return -ESHUTDOWN;
308 
309 	sport = udp_flow_src_port(bareudp->net, skb,
310 				  bareudp->sport_min, USHRT_MAX,
311 				  true);
312 	rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
313 				   sport, bareudp->port, key->tos,
314 				   use_cache ?
315 				   (struct dst_cache *)&info->dst_cache : NULL);
316 
317 	if (IS_ERR(rt))
318 		return PTR_ERR(rt);
319 
320 	skb_tunnel_check_pmtu(skb, &rt->dst,
321 			      BAREUDP_IPV4_HLEN + info->options_len, false);
322 
323 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
324 	ttl = key->ttl;
325 	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
326 	skb_scrub_packet(skb, xnet);
327 
328 	err = -ENOSPC;
329 	if (!skb_pull(skb, skb_network_offset(skb)))
330 		goto free_dst;
331 
332 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
333 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
334 
335 	err = skb_cow_head(skb, min_headroom);
336 	if (unlikely(err))
337 		goto free_dst;
338 
339 	err = udp_tunnel_handle_offloads(skb, udp_sum);
340 	if (err)
341 		goto free_dst;
342 
343 	skb_set_inner_protocol(skb, bareudp->ethertype);
344 	udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
345 			    tos, ttl, df, sport, bareudp->port,
346 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
347 			    !(info->key.tun_flags & TUNNEL_CSUM));
348 	return 0;
349 
350 free_dst:
351 	dst_release(&rt->dst);
352 	return err;
353 }
354 
355 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
356 			     struct bareudp_dev *bareudp,
357 			     const struct ip_tunnel_info *info)
358 {
359 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
360 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
361 	struct socket *sock  = rcu_dereference(bareudp->sock);
362 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
363 	const struct ip_tunnel_key *key = &info->key;
364 	struct dst_entry *dst = NULL;
365 	struct in6_addr saddr, daddr;
366 	int min_headroom;
367 	__u8 prio, ttl;
368 	__be16 sport;
369 	int err;
370 
371 	if (!sock)
372 		return -ESHUTDOWN;
373 
374 	sport = udp_flow_src_port(bareudp->net, skb,
375 				  bareudp->sport_min, USHRT_MAX,
376 				  true);
377 	dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, 0, &saddr,
378 				     key, sport, bareudp->port, key->tos,
379 				     use_cache ?
380 				     (struct dst_cache *) &info->dst_cache : NULL);
381 	if (IS_ERR(dst))
382 		return PTR_ERR(dst);
383 
384 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
385 			      false);
386 
387 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
388 	ttl = key->ttl;
389 
390 	skb_scrub_packet(skb, xnet);
391 
392 	err = -ENOSPC;
393 	if (!skb_pull(skb, skb_network_offset(skb)))
394 		goto free_dst;
395 
396 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
397 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
398 
399 	err = skb_cow_head(skb, min_headroom);
400 	if (unlikely(err))
401 		goto free_dst;
402 
403 	err = udp_tunnel_handle_offloads(skb, udp_sum);
404 	if (err)
405 		goto free_dst;
406 
407 	daddr = info->key.u.ipv6.dst;
408 	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
409 			     &saddr, &daddr, prio, ttl,
410 			     info->key.label, sport, bareudp->port,
411 			     !(info->key.tun_flags & TUNNEL_CSUM));
412 	return 0;
413 
414 free_dst:
415 	dst_release(dst);
416 	return err;
417 }
418 
419 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
420 {
421 	if (bareudp->ethertype == proto)
422 		return true;
423 
424 	if (!bareudp->multi_proto_mode)
425 		return false;
426 
427 	if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
428 	    proto == htons(ETH_P_MPLS_MC))
429 		return true;
430 
431 	if (bareudp->ethertype == htons(ETH_P_IP) &&
432 	    proto == htons(ETH_P_IPV6))
433 		return true;
434 
435 	return false;
436 }
437 
438 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
439 {
440 	struct bareudp_dev *bareudp = netdev_priv(dev);
441 	struct ip_tunnel_info *info = NULL;
442 	int err;
443 
444 	if (!bareudp_proto_valid(bareudp, skb->protocol)) {
445 		err = -EINVAL;
446 		goto tx_error;
447 	}
448 
449 	info = skb_tunnel_info(skb);
450 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
451 		err = -EINVAL;
452 		goto tx_error;
453 	}
454 
455 	rcu_read_lock();
456 	if (ipv6_mod_enabled() && info->mode & IP_TUNNEL_INFO_IPV6)
457 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
458 	else
459 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
460 
461 	rcu_read_unlock();
462 
463 	if (likely(!err))
464 		return NETDEV_TX_OK;
465 tx_error:
466 	dev_kfree_skb(skb);
467 
468 	if (err == -ELOOP)
469 		dev->stats.collisions++;
470 	else if (err == -ENETUNREACH)
471 		dev->stats.tx_carrier_errors++;
472 
473 	dev->stats.tx_errors++;
474 	return NETDEV_TX_OK;
475 }
476 
477 static int bareudp_fill_metadata_dst(struct net_device *dev,
478 				     struct sk_buff *skb)
479 {
480 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
481 	struct bareudp_dev *bareudp = netdev_priv(dev);
482 	bool use_cache;
483 	__be16 sport;
484 
485 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
486 	sport = udp_flow_src_port(bareudp->net, skb,
487 				  bareudp->sport_min, USHRT_MAX,
488 				  true);
489 
490 	if (!ipv6_mod_enabled() || ip_tunnel_info_af(info) == AF_INET) {
491 		struct rtable *rt;
492 		__be32 saddr;
493 
494 		rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
495 					   &info->key, sport, bareudp->port,
496 					   info->key.tos,
497 					   use_cache ? &info->dst_cache : NULL);
498 		if (IS_ERR(rt))
499 			return PTR_ERR(rt);
500 
501 		ip_rt_put(rt);
502 		info->key.u.ipv4.src = saddr;
503 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
504 		struct dst_entry *dst;
505 		struct in6_addr saddr;
506 		struct socket *sock = rcu_dereference(bareudp->sock);
507 
508 		dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
509 					     0, &saddr, &info->key,
510 					     sport, bareudp->port, info->key.tos,
511 					     use_cache ? &info->dst_cache : NULL);
512 		if (IS_ERR(dst))
513 			return PTR_ERR(dst);
514 
515 		dst_release(dst);
516 		info->key.u.ipv6.src = saddr;
517 	} else {
518 		return -EINVAL;
519 	}
520 
521 	info->key.tp_src = sport;
522 	info->key.tp_dst = bareudp->port;
523 	return 0;
524 }
525 
526 static const struct net_device_ops bareudp_netdev_ops = {
527 	.ndo_init               = bareudp_init,
528 	.ndo_uninit             = bareudp_uninit,
529 	.ndo_open               = bareudp_open,
530 	.ndo_stop               = bareudp_stop,
531 	.ndo_start_xmit         = bareudp_xmit,
532 	.ndo_get_stats64        = dev_get_tstats64,
533 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
534 };
535 
536 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
537 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
538 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
539 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
540 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
541 };
542 
543 /* Info for udev, that this is a virtual tunnel endpoint */
544 static const struct device_type bareudp_type = {
545 	.name = "bareudp",
546 };
547 
548 /* Initialize the device structure. */
549 static void bareudp_setup(struct net_device *dev)
550 {
551 	dev->netdev_ops = &bareudp_netdev_ops;
552 	dev->needs_free_netdev = true;
553 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
554 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
555 	dev->features    |= NETIF_F_RXCSUM;
556 	dev->features    |= NETIF_F_LLTX;
557 	dev->features    |= NETIF_F_GSO_SOFTWARE;
558 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
559 	dev->hw_features |= NETIF_F_RXCSUM;
560 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
561 	dev->hard_header_len = 0;
562 	dev->addr_len = 0;
563 	dev->mtu = ETH_DATA_LEN;
564 	dev->min_mtu = IPV4_MIN_MTU;
565 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
566 	dev->type = ARPHRD_NONE;
567 	netif_keep_dst(dev);
568 	dev->priv_flags |= IFF_NO_QUEUE;
569 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
570 }
571 
572 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
573 			    struct netlink_ext_ack *extack)
574 {
575 	if (!data) {
576 		NL_SET_ERR_MSG(extack,
577 			       "Not enough attributes provided to perform the operation");
578 		return -EINVAL;
579 	}
580 	return 0;
581 }
582 
583 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
584 			struct netlink_ext_ack *extack)
585 {
586 	memset(conf, 0, sizeof(*conf));
587 
588 	if (!data[IFLA_BAREUDP_PORT]) {
589 		NL_SET_ERR_MSG(extack, "port not specified");
590 		return -EINVAL;
591 	}
592 	if (!data[IFLA_BAREUDP_ETHERTYPE]) {
593 		NL_SET_ERR_MSG(extack, "ethertype not specified");
594 		return -EINVAL;
595 	}
596 
597 	conf->port = nla_get_u16(data[IFLA_BAREUDP_PORT]);
598 	conf->ethertype = nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
599 
600 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
601 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
602 
603 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
604 		conf->multi_proto_mode = true;
605 
606 	return 0;
607 }
608 
609 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
610 					    const struct bareudp_conf *conf)
611 {
612 	struct bareudp_dev *bareudp, *t = NULL;
613 
614 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
615 		if (conf->port == bareudp->port)
616 			t = bareudp;
617 	}
618 	return t;
619 }
620 
621 static int bareudp_configure(struct net *net, struct net_device *dev,
622 			     struct bareudp_conf *conf,
623 			     struct netlink_ext_ack *extack)
624 {
625 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
626 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
627 	int err;
628 
629 	bareudp->net = net;
630 	bareudp->dev = dev;
631 	t = bareudp_find_dev(bn, conf);
632 	if (t) {
633 		NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
634 		return -EBUSY;
635 	}
636 
637 	if (conf->multi_proto_mode &&
638 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
639 	     conf->ethertype != htons(ETH_P_IP))) {
640 		NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
641 		return -EINVAL;
642 	}
643 
644 	bareudp->port = conf->port;
645 	bareudp->ethertype = conf->ethertype;
646 	bareudp->sport_min = conf->sport_min;
647 	bareudp->multi_proto_mode = conf->multi_proto_mode;
648 
649 	err = register_netdevice(dev);
650 	if (err)
651 		return err;
652 
653 	list_add(&bareudp->next, &bn->bareudp_list);
654 	return 0;
655 }
656 
657 static int bareudp_link_config(struct net_device *dev,
658 			       struct nlattr *tb[])
659 {
660 	int err;
661 
662 	if (tb[IFLA_MTU]) {
663 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
664 		if (err)
665 			return err;
666 	}
667 	return 0;
668 }
669 
670 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
671 {
672 	struct bareudp_dev *bareudp = netdev_priv(dev);
673 
674 	list_del(&bareudp->next);
675 	unregister_netdevice_queue(dev, head);
676 }
677 
678 static int bareudp_newlink(struct net *net, struct net_device *dev,
679 			   struct nlattr *tb[], struct nlattr *data[],
680 			   struct netlink_ext_ack *extack)
681 {
682 	struct bareudp_conf conf;
683 	int err;
684 
685 	err = bareudp2info(data, &conf, extack);
686 	if (err)
687 		return err;
688 
689 	err = bareudp_configure(net, dev, &conf, extack);
690 	if (err)
691 		return err;
692 
693 	err = bareudp_link_config(dev, tb);
694 	if (err)
695 		goto err_unconfig;
696 
697 	return 0;
698 
699 err_unconfig:
700 	bareudp_dellink(dev, NULL);
701 	return err;
702 }
703 
704 static size_t bareudp_get_size(const struct net_device *dev)
705 {
706 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
707 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
708 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
709 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
710 		0;
711 }
712 
713 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
714 {
715 	struct bareudp_dev *bareudp = netdev_priv(dev);
716 
717 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
718 		goto nla_put_failure;
719 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
720 		goto nla_put_failure;
721 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
722 		goto nla_put_failure;
723 	if (bareudp->multi_proto_mode &&
724 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
725 		goto nla_put_failure;
726 
727 	return 0;
728 
729 nla_put_failure:
730 	return -EMSGSIZE;
731 }
732 
733 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
734 	.kind           = "bareudp",
735 	.maxtype        = IFLA_BAREUDP_MAX,
736 	.policy         = bareudp_policy,
737 	.priv_size      = sizeof(struct bareudp_dev),
738 	.setup          = bareudp_setup,
739 	.validate       = bareudp_validate,
740 	.newlink        = bareudp_newlink,
741 	.dellink        = bareudp_dellink,
742 	.get_size       = bareudp_get_size,
743 	.fill_info      = bareudp_fill_info,
744 };
745 
746 static __net_init int bareudp_init_net(struct net *net)
747 {
748 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
749 
750 	INIT_LIST_HEAD(&bn->bareudp_list);
751 	return 0;
752 }
753 
754 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
755 {
756 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
757 	struct bareudp_dev *bareudp, *next;
758 
759 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
760 		unregister_netdevice_queue(bareudp->dev, head);
761 }
762 
763 static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
764 {
765 	struct net *net;
766 	LIST_HEAD(list);
767 
768 	rtnl_lock();
769 	list_for_each_entry(net, net_list, exit_list)
770 		bareudp_destroy_tunnels(net, &list);
771 
772 	/* unregister the devices gathered above */
773 	unregister_netdevice_many(&list);
774 	rtnl_unlock();
775 }
776 
777 static struct pernet_operations bareudp_net_ops = {
778 	.init = bareudp_init_net,
779 	.exit_batch = bareudp_exit_batch_net,
780 	.id   = &bareudp_net_id,
781 	.size = sizeof(struct bareudp_net),
782 };
783 
784 static int __init bareudp_init_module(void)
785 {
786 	int rc;
787 
788 	rc = register_pernet_subsys(&bareudp_net_ops);
789 	if (rc)
790 		goto out1;
791 
792 	rc = rtnl_link_register(&bareudp_link_ops);
793 	if (rc)
794 		goto out2;
795 
796 	return 0;
797 out2:
798 	unregister_pernet_subsys(&bareudp_net_ops);
799 out1:
800 	return rc;
801 }
802 late_initcall(bareudp_init_module);
803 
804 static void __exit bareudp_cleanup_module(void)
805 {
806 	rtnl_link_unregister(&bareudp_link_ops);
807 	unregister_pernet_subsys(&bareudp_net_ops);
808 }
809 module_exit(bareudp_cleanup_module);
810 
811 MODULE_ALIAS_RTNL_LINK("bareudp");
812 MODULE_LICENSE("GPL");
813 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
814 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
815