xref: /openbmc/linux/drivers/net/bareudp.c (revision da60fbe7)
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 
129 	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
130 	if (!tun_dst) {
131 		bareudp->dev->stats.rx_dropped++;
132 		goto drop;
133 	}
134 	skb_dst_set(skb, &tun_dst->dst);
135 	skb->dev = bareudp->dev;
136 	oiph = skb_network_header(skb);
137 	skb_reset_network_header(skb);
138 
139 	if (family == AF_INET)
140 		err = IP_ECN_decapsulate(oiph, skb);
141 #if IS_ENABLED(CONFIG_IPV6)
142 	else
143 		err = IP6_ECN_decapsulate(oiph, skb);
144 #endif
145 
146 	if (unlikely(err)) {
147 		if (log_ecn_error) {
148 			if  (family == AF_INET)
149 				net_info_ratelimited("non-ECT from %pI4 "
150 						     "with TOS=%#x\n",
151 						     &((struct iphdr *)oiph)->saddr,
152 						     ((struct iphdr *)oiph)->tos);
153 #if IS_ENABLED(CONFIG_IPV6)
154 			else
155 				net_info_ratelimited("non-ECT from %pI6\n",
156 						     &((struct ipv6hdr *)oiph)->saddr);
157 #endif
158 		}
159 		if (err > 1) {
160 			++bareudp->dev->stats.rx_frame_errors;
161 			++bareudp->dev->stats.rx_errors;
162 			goto drop;
163 		}
164 	}
165 
166 	len = skb->len;
167 	err = gro_cells_receive(&bareudp->gro_cells, skb);
168 	if (likely(err == NET_RX_SUCCESS)) {
169 		stats = this_cpu_ptr(bareudp->dev->tstats);
170 		u64_stats_update_begin(&stats->syncp);
171 		stats->rx_packets++;
172 		stats->rx_bytes += len;
173 		u64_stats_update_end(&stats->syncp);
174 	}
175 	return 0;
176 drop:
177 	/* Consume bad packet */
178 	kfree_skb(skb);
179 
180 	return 0;
181 }
182 
183 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
184 {
185 	return 0;
186 }
187 
188 static int bareudp_init(struct net_device *dev)
189 {
190 	struct bareudp_dev *bareudp = netdev_priv(dev);
191 	int err;
192 
193 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
194 	if (!dev->tstats)
195 		return -ENOMEM;
196 
197 	err = gro_cells_init(&bareudp->gro_cells, dev);
198 	if (err) {
199 		free_percpu(dev->tstats);
200 		return err;
201 	}
202 	return 0;
203 }
204 
205 static void bareudp_uninit(struct net_device *dev)
206 {
207 	struct bareudp_dev *bareudp = netdev_priv(dev);
208 
209 	gro_cells_destroy(&bareudp->gro_cells);
210 	free_percpu(dev->tstats);
211 }
212 
213 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
214 {
215 	struct udp_port_cfg udp_conf;
216 	struct socket *sock;
217 	int err;
218 
219 	memset(&udp_conf, 0, sizeof(udp_conf));
220 #if IS_ENABLED(CONFIG_IPV6)
221 	udp_conf.family = AF_INET6;
222 #else
223 	udp_conf.family = AF_INET;
224 #endif
225 	udp_conf.local_udp_port = port;
226 	/* Open UDP socket */
227 	err = udp_sock_create(net, &udp_conf, &sock);
228 	if (err < 0)
229 		return ERR_PTR(err);
230 
231 	return sock;
232 }
233 
234 /* Create new listen socket if needed */
235 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
236 {
237 	struct udp_tunnel_sock_cfg tunnel_cfg;
238 	struct socket *sock;
239 
240 	sock = bareudp_create_sock(bareudp->net, port);
241 	if (IS_ERR(sock))
242 		return PTR_ERR(sock);
243 
244 	/* Mark socket as an encapsulation socket */
245 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
246 	tunnel_cfg.sk_user_data = bareudp;
247 	tunnel_cfg.encap_type = 1;
248 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
249 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
250 	tunnel_cfg.encap_destroy = NULL;
251 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
252 
253 	if (sock->sk->sk_family == AF_INET6)
254 		udp_encap_enable();
255 
256 	rcu_assign_pointer(bareudp->sock, sock);
257 	return 0;
258 }
259 
260 static int bareudp_open(struct net_device *dev)
261 {
262 	struct bareudp_dev *bareudp = netdev_priv(dev);
263 	int ret = 0;
264 
265 	ret =  bareudp_socket_create(bareudp, bareudp->port);
266 	return ret;
267 }
268 
269 static void bareudp_sock_release(struct bareudp_dev *bareudp)
270 {
271 	struct socket *sock;
272 
273 	sock = bareudp->sock;
274 	rcu_assign_pointer(bareudp->sock, NULL);
275 	synchronize_net();
276 	udp_tunnel_sock_release(sock);
277 }
278 
279 static int bareudp_stop(struct net_device *dev)
280 {
281 	struct bareudp_dev *bareudp = netdev_priv(dev);
282 
283 	bareudp_sock_release(bareudp);
284 	return 0;
285 }
286 
287 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
288 			    struct bareudp_dev *bareudp,
289 			    const struct ip_tunnel_info *info)
290 {
291 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
292 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
293 	struct socket *sock = rcu_dereference(bareudp->sock);
294 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
295 	const struct ip_tunnel_key *key = &info->key;
296 	struct rtable *rt;
297 	__be16 sport, df;
298 	int min_headroom;
299 	__u8 tos, ttl;
300 	__be32 saddr;
301 	int err;
302 
303 	if (!sock)
304 		return -ESHUTDOWN;
305 
306 	rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr, info,
307 				    IPPROTO_UDP, use_cache);
308 
309 	if (IS_ERR(rt))
310 		return PTR_ERR(rt);
311 
312 	skb_tunnel_check_pmtu(skb, &rt->dst,
313 			      BAREUDP_IPV4_HLEN + info->options_len);
314 
315 	sport = udp_flow_src_port(bareudp->net, skb,
316 				  bareudp->sport_min, USHRT_MAX,
317 				  true);
318 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
319 	ttl = key->ttl;
320 	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
321 	skb_scrub_packet(skb, xnet);
322 
323 	err = -ENOSPC;
324 	if (!skb_pull(skb, skb_network_offset(skb)))
325 		goto free_dst;
326 
327 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
328 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
329 
330 	err = skb_cow_head(skb, min_headroom);
331 	if (unlikely(err))
332 		goto free_dst;
333 
334 	err = udp_tunnel_handle_offloads(skb, udp_sum);
335 	if (err)
336 		goto free_dst;
337 
338 	skb_set_inner_protocol(skb, bareudp->ethertype);
339 	udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
340 			    tos, ttl, df, sport, bareudp->port,
341 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
342 			    !(info->key.tun_flags & TUNNEL_CSUM));
343 	return 0;
344 
345 free_dst:
346 	dst_release(&rt->dst);
347 	return err;
348 }
349 
350 #if IS_ENABLED(CONFIG_IPV6)
351 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
352 			     struct bareudp_dev *bareudp,
353 			     const struct ip_tunnel_info *info)
354 {
355 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
356 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
357 	struct socket *sock  = rcu_dereference(bareudp->sock);
358 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
359 	const struct ip_tunnel_key *key = &info->key;
360 	struct dst_entry *dst = NULL;
361 	struct in6_addr saddr, daddr;
362 	int min_headroom;
363 	__u8 prio, ttl;
364 	__be16 sport;
365 	int err;
366 
367 	if (!sock)
368 		return -ESHUTDOWN;
369 
370 	dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock, &saddr, info,
371 				    IPPROTO_UDP, use_cache);
372 	if (IS_ERR(dst))
373 		return PTR_ERR(dst);
374 
375 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len);
376 
377 	sport = udp_flow_src_port(bareudp->net, skb,
378 				  bareudp->sport_min, USHRT_MAX,
379 				  true);
380 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
381 	ttl = key->ttl;
382 
383 	skb_scrub_packet(skb, xnet);
384 
385 	err = -ENOSPC;
386 	if (!skb_pull(skb, skb_network_offset(skb)))
387 		goto free_dst;
388 
389 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
390 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
391 
392 	err = skb_cow_head(skb, min_headroom);
393 	if (unlikely(err))
394 		goto free_dst;
395 
396 	err = udp_tunnel_handle_offloads(skb, udp_sum);
397 	if (err)
398 		goto free_dst;
399 
400 	daddr = info->key.u.ipv6.dst;
401 	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
402 			     &saddr, &daddr, prio, ttl,
403 			     info->key.label, sport, bareudp->port,
404 			     !(info->key.tun_flags & TUNNEL_CSUM));
405 	return 0;
406 
407 free_dst:
408 	dst_release(dst);
409 	return err;
410 }
411 #endif
412 
413 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
414 {
415 	struct bareudp_dev *bareudp = netdev_priv(dev);
416 	struct ip_tunnel_info *info = NULL;
417 	int err;
418 
419 	if (skb->protocol != bareudp->ethertype) {
420 		if (!bareudp->multi_proto_mode ||
421 		    (skb->protocol !=  htons(ETH_P_MPLS_MC) &&
422 		     skb->protocol !=  htons(ETH_P_IPV6))) {
423 			err = -EINVAL;
424 			goto tx_error;
425 		}
426 	}
427 
428 	info = skb_tunnel_info(skb);
429 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
430 		err = -EINVAL;
431 		goto tx_error;
432 	}
433 
434 	rcu_read_lock();
435 #if IS_ENABLED(CONFIG_IPV6)
436 	if (info->mode & IP_TUNNEL_INFO_IPV6)
437 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
438 	else
439 #endif
440 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
441 
442 	rcu_read_unlock();
443 
444 	if (likely(!err))
445 		return NETDEV_TX_OK;
446 tx_error:
447 	dev_kfree_skb(skb);
448 
449 	if (err == -ELOOP)
450 		dev->stats.collisions++;
451 	else if (err == -ENETUNREACH)
452 		dev->stats.tx_carrier_errors++;
453 
454 	dev->stats.tx_errors++;
455 	return NETDEV_TX_OK;
456 }
457 
458 static int bareudp_fill_metadata_dst(struct net_device *dev,
459 				     struct sk_buff *skb)
460 {
461 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
462 	struct bareudp_dev *bareudp = netdev_priv(dev);
463 	bool use_cache;
464 
465 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
466 
467 	if (ip_tunnel_info_af(info) == AF_INET) {
468 		struct rtable *rt;
469 		__be32 saddr;
470 
471 		rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr,
472 					    info, IPPROTO_UDP, use_cache);
473 		if (IS_ERR(rt))
474 			return PTR_ERR(rt);
475 
476 		ip_rt_put(rt);
477 		info->key.u.ipv4.src = saddr;
478 #if IS_ENABLED(CONFIG_IPV6)
479 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
480 		struct dst_entry *dst;
481 		struct in6_addr saddr;
482 		struct socket *sock = rcu_dereference(bareudp->sock);
483 
484 		dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock,
485 					    &saddr, info, IPPROTO_UDP,
486 					    use_cache);
487 		if (IS_ERR(dst))
488 			return PTR_ERR(dst);
489 
490 		dst_release(dst);
491 		info->key.u.ipv6.src = saddr;
492 #endif
493 	} else {
494 		return -EINVAL;
495 	}
496 
497 	info->key.tp_src = udp_flow_src_port(bareudp->net, skb,
498 					     bareudp->sport_min,
499 			USHRT_MAX, true);
500 	info->key.tp_dst = bareudp->port;
501 	return 0;
502 }
503 
504 static const struct net_device_ops bareudp_netdev_ops = {
505 	.ndo_init               = bareudp_init,
506 	.ndo_uninit             = bareudp_uninit,
507 	.ndo_open               = bareudp_open,
508 	.ndo_stop               = bareudp_stop,
509 	.ndo_start_xmit         = bareudp_xmit,
510 	.ndo_get_stats64        = ip_tunnel_get_stats64,
511 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
512 };
513 
514 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
515 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
516 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
517 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
518 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
519 };
520 
521 /* Info for udev, that this is a virtual tunnel endpoint */
522 static struct device_type bareudp_type = {
523 	.name = "bareudp",
524 };
525 
526 /* Initialize the device structure. */
527 static void bareudp_setup(struct net_device *dev)
528 {
529 	dev->netdev_ops = &bareudp_netdev_ops;
530 	dev->needs_free_netdev = true;
531 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
532 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
533 	dev->features    |= NETIF_F_RXCSUM;
534 	dev->features    |= NETIF_F_GSO_SOFTWARE;
535 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
536 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
537 	dev->hard_header_len = 0;
538 	dev->addr_len = 0;
539 	dev->mtu = ETH_DATA_LEN;
540 	dev->min_mtu = IPV4_MIN_MTU;
541 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
542 	dev->type = ARPHRD_NONE;
543 	netif_keep_dst(dev);
544 	dev->priv_flags |= IFF_NO_QUEUE;
545 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
546 }
547 
548 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
549 			    struct netlink_ext_ack *extack)
550 {
551 	if (!data) {
552 		NL_SET_ERR_MSG(extack,
553 			       "Not enough attributes provided to perform the operation");
554 		return -EINVAL;
555 	}
556 	return 0;
557 }
558 
559 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf)
560 {
561 	if (!data[IFLA_BAREUDP_PORT] || !data[IFLA_BAREUDP_ETHERTYPE])
562 		return -EINVAL;
563 
564 	if (data[IFLA_BAREUDP_PORT])
565 		conf->port =  nla_get_u16(data[IFLA_BAREUDP_PORT]);
566 
567 	if (data[IFLA_BAREUDP_ETHERTYPE])
568 		conf->ethertype =  nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
569 
570 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
571 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
572 
573 	return 0;
574 }
575 
576 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
577 					    const struct bareudp_conf *conf)
578 {
579 	struct bareudp_dev *bareudp, *t = NULL;
580 
581 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
582 		if (conf->port == bareudp->port)
583 			t = bareudp;
584 	}
585 	return t;
586 }
587 
588 static int bareudp_configure(struct net *net, struct net_device *dev,
589 			     struct bareudp_conf *conf)
590 {
591 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
592 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
593 	int err;
594 
595 	bareudp->net = net;
596 	bareudp->dev = dev;
597 	t = bareudp_find_dev(bn, conf);
598 	if (t)
599 		return -EBUSY;
600 
601 	if (conf->multi_proto_mode &&
602 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
603 	     conf->ethertype != htons(ETH_P_IP)))
604 		return -EINVAL;
605 
606 	bareudp->port = conf->port;
607 	bareudp->ethertype = conf->ethertype;
608 	bareudp->sport_min = conf->sport_min;
609 	bareudp->multi_proto_mode = conf->multi_proto_mode;
610 	err = register_netdevice(dev);
611 	if (err)
612 		return err;
613 
614 	list_add(&bareudp->next, &bn->bareudp_list);
615 	return 0;
616 }
617 
618 static int bareudp_link_config(struct net_device *dev,
619 			       struct nlattr *tb[])
620 {
621 	int err;
622 
623 	if (tb[IFLA_MTU]) {
624 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
625 		if (err)
626 			return err;
627 	}
628 	return 0;
629 }
630 
631 static int bareudp_newlink(struct net *net, struct net_device *dev,
632 			   struct nlattr *tb[], struct nlattr *data[],
633 			   struct netlink_ext_ack *extack)
634 {
635 	struct bareudp_conf conf;
636 	int err;
637 
638 	err = bareudp2info(data, &conf);
639 	if (err)
640 		return err;
641 
642 	err = bareudp_configure(net, dev, &conf);
643 	if (err)
644 		return err;
645 
646 	err = bareudp_link_config(dev, tb);
647 	if (err)
648 		return err;
649 
650 	return 0;
651 }
652 
653 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
654 {
655 	struct bareudp_dev *bareudp = netdev_priv(dev);
656 
657 	list_del(&bareudp->next);
658 	unregister_netdevice_queue(dev, head);
659 }
660 
661 static size_t bareudp_get_size(const struct net_device *dev)
662 {
663 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
664 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
665 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
666 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
667 		0;
668 }
669 
670 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
671 {
672 	struct bareudp_dev *bareudp = netdev_priv(dev);
673 
674 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
675 		goto nla_put_failure;
676 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
677 		goto nla_put_failure;
678 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
679 		goto nla_put_failure;
680 	if (bareudp->multi_proto_mode &&
681 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
682 		goto nla_put_failure;
683 
684 	return 0;
685 
686 nla_put_failure:
687 	return -EMSGSIZE;
688 }
689 
690 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
691 	.kind           = "bareudp",
692 	.maxtype        = IFLA_BAREUDP_MAX,
693 	.policy         = bareudp_policy,
694 	.priv_size      = sizeof(struct bareudp_dev),
695 	.setup          = bareudp_setup,
696 	.validate       = bareudp_validate,
697 	.newlink        = bareudp_newlink,
698 	.dellink        = bareudp_dellink,
699 	.get_size       = bareudp_get_size,
700 	.fill_info      = bareudp_fill_info,
701 };
702 
703 struct net_device *bareudp_dev_create(struct net *net, const char *name,
704 				      u8 name_assign_type,
705 				      struct bareudp_conf *conf)
706 {
707 	struct nlattr *tb[IFLA_MAX + 1];
708 	struct net_device *dev;
709 	LIST_HEAD(list_kill);
710 	int err;
711 
712 	memset(tb, 0, sizeof(tb));
713 	dev = rtnl_create_link(net, name, name_assign_type,
714 			       &bareudp_link_ops, tb, NULL);
715 	if (IS_ERR(dev))
716 		return dev;
717 
718 	err = bareudp_configure(net, dev, conf);
719 	if (err) {
720 		free_netdev(dev);
721 		return ERR_PTR(err);
722 	}
723 	err = dev_set_mtu(dev, IP_MAX_MTU - BAREUDP_BASE_HLEN);
724 	if (err)
725 		goto err;
726 
727 	err = rtnl_configure_link(dev, NULL);
728 	if (err < 0)
729 		goto err;
730 
731 	return dev;
732 err:
733 	bareudp_dellink(dev, &list_kill);
734 	unregister_netdevice_many(&list_kill);
735 	return ERR_PTR(err);
736 }
737 EXPORT_SYMBOL_GPL(bareudp_dev_create);
738 
739 static __net_init int bareudp_init_net(struct net *net)
740 {
741 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
742 
743 	INIT_LIST_HEAD(&bn->bareudp_list);
744 	return 0;
745 }
746 
747 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
748 {
749 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
750 	struct bareudp_dev *bareudp, *next;
751 
752 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
753 		unregister_netdevice_queue(bareudp->dev, head);
754 }
755 
756 static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
757 {
758 	struct net *net;
759 	LIST_HEAD(list);
760 
761 	rtnl_lock();
762 	list_for_each_entry(net, net_list, exit_list)
763 		bareudp_destroy_tunnels(net, &list);
764 
765 	/* unregister the devices gathered above */
766 	unregister_netdevice_many(&list);
767 	rtnl_unlock();
768 }
769 
770 static struct pernet_operations bareudp_net_ops = {
771 	.init = bareudp_init_net,
772 	.exit_batch = bareudp_exit_batch_net,
773 	.id   = &bareudp_net_id,
774 	.size = sizeof(struct bareudp_net),
775 };
776 
777 static int __init bareudp_init_module(void)
778 {
779 	int rc;
780 
781 	rc = register_pernet_subsys(&bareudp_net_ops);
782 	if (rc)
783 		goto out1;
784 
785 	rc = rtnl_link_register(&bareudp_link_ops);
786 	if (rc)
787 		goto out2;
788 
789 	return 0;
790 out2:
791 	unregister_pernet_subsys(&bareudp_net_ops);
792 out1:
793 	return rc;
794 }
795 late_initcall(bareudp_init_module);
796 
797 static void __exit bareudp_cleanup_module(void)
798 {
799 	rtnl_link_unregister(&bareudp_link_ops);
800 	unregister_pernet_subsys(&bareudp_net_ops);
801 }
802 module_exit(bareudp_cleanup_module);
803 
804 MODULE_LICENSE("GPL");
805 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
806 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
807