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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 
bareudp_udp_encap_recv(struct sock * sk,struct sk_buff * skb)54 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
55 {
56 	struct metadata_dst *tun_dst = NULL;
57 	struct bareudp_dev *bareudp;
58 	unsigned short family;
59 	unsigned int len;
60 	__be16 proto;
61 	void *oiph;
62 	int err;
63 
64 	bareudp = rcu_dereference_sk_user_data(sk);
65 	if (!bareudp)
66 		goto drop;
67 
68 	if (skb->protocol ==  htons(ETH_P_IP))
69 		family = AF_INET;
70 	else
71 		family = AF_INET6;
72 
73 	if (bareudp->ethertype == htons(ETH_P_IP)) {
74 		__u8 ipversion;
75 
76 		if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
77 				  sizeof(ipversion))) {
78 			bareudp->dev->stats.rx_dropped++;
79 			goto drop;
80 		}
81 		ipversion >>= 4;
82 
83 		if (ipversion == 4) {
84 			proto = htons(ETH_P_IP);
85 		} else if (ipversion == 6 && bareudp->multi_proto_mode) {
86 			proto = htons(ETH_P_IPV6);
87 		} else {
88 			bareudp->dev->stats.rx_dropped++;
89 			goto drop;
90 		}
91 	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
92 		struct iphdr *tunnel_hdr;
93 
94 		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
95 		if (tunnel_hdr->version == 4) {
96 			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
97 				proto = bareudp->ethertype;
98 			} else if (bareudp->multi_proto_mode &&
99 				   ipv4_is_multicast(tunnel_hdr->daddr)) {
100 				proto = htons(ETH_P_MPLS_MC);
101 			} else {
102 				bareudp->dev->stats.rx_dropped++;
103 				goto drop;
104 			}
105 		} else {
106 			int addr_type;
107 			struct ipv6hdr *tunnel_hdr_v6;
108 
109 			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
110 			addr_type =
111 			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
112 			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
113 				proto = bareudp->ethertype;
114 			} else if (bareudp->multi_proto_mode &&
115 				   (addr_type & IPV6_ADDR_MULTICAST)) {
116 				proto = htons(ETH_P_MPLS_MC);
117 			} else {
118 				bareudp->dev->stats.rx_dropped++;
119 				goto drop;
120 			}
121 		}
122 	} else {
123 		proto = bareudp->ethertype;
124 	}
125 
126 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
127 				 proto,
128 				 !net_eq(bareudp->net,
129 				 dev_net(bareudp->dev)))) {
130 		bareudp->dev->stats.rx_dropped++;
131 		goto drop;
132 	}
133 	tun_dst = udp_tun_rx_dst(skb, family, TUNNEL_KEY, 0, 0);
134 	if (!tun_dst) {
135 		bareudp->dev->stats.rx_dropped++;
136 		goto drop;
137 	}
138 	skb_dst_set(skb, &tun_dst->dst);
139 	skb->dev = bareudp->dev;
140 	oiph = skb_network_header(skb);
141 	skb_reset_network_header(skb);
142 
143 	if (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
144 		err = IP_ECN_decapsulate(oiph, skb);
145 	else
146 		err = IP6_ECN_decapsulate(oiph, skb);
147 
148 	if (unlikely(err)) {
149 		if (log_ecn_error) {
150 			if  (!IS_ENABLED(CONFIG_IPV6) || family == AF_INET)
151 				net_info_ratelimited("non-ECT from %pI4 "
152 						     "with TOS=%#x\n",
153 						     &((struct iphdr *)oiph)->saddr,
154 						     ((struct iphdr *)oiph)->tos);
155 			else
156 				net_info_ratelimited("non-ECT from %pI6\n",
157 						     &((struct ipv6hdr *)oiph)->saddr);
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 		dev_sw_netstats_rx_add(bareudp->dev, len);
170 
171 	return 0;
172 drop:
173 	/* Consume bad packet */
174 	kfree_skb(skb);
175 
176 	return 0;
177 }
178 
bareudp_err_lookup(struct sock * sk,struct sk_buff * skb)179 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
180 {
181 	return 0;
182 }
183 
bareudp_init(struct net_device * dev)184 static int bareudp_init(struct net_device *dev)
185 {
186 	struct bareudp_dev *bareudp = netdev_priv(dev);
187 	int err;
188 
189 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
190 	if (!dev->tstats)
191 		return -ENOMEM;
192 
193 	err = gro_cells_init(&bareudp->gro_cells, dev);
194 	if (err) {
195 		free_percpu(dev->tstats);
196 		return err;
197 	}
198 	return 0;
199 }
200 
bareudp_uninit(struct net_device * dev)201 static void bareudp_uninit(struct net_device *dev)
202 {
203 	struct bareudp_dev *bareudp = netdev_priv(dev);
204 
205 	gro_cells_destroy(&bareudp->gro_cells);
206 	free_percpu(dev->tstats);
207 }
208 
bareudp_create_sock(struct net * net,__be16 port)209 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
210 {
211 	struct udp_port_cfg udp_conf;
212 	struct socket *sock;
213 	int err;
214 
215 	memset(&udp_conf, 0, sizeof(udp_conf));
216 #if IS_ENABLED(CONFIG_IPV6)
217 	udp_conf.family = AF_INET6;
218 #else
219 	udp_conf.family = AF_INET;
220 #endif
221 	udp_conf.local_udp_port = port;
222 	/* Open UDP socket */
223 	err = udp_sock_create(net, &udp_conf, &sock);
224 	if (err < 0)
225 		return ERR_PTR(err);
226 
227 	return sock;
228 }
229 
230 /* Create new listen socket if needed */
bareudp_socket_create(struct bareudp_dev * bareudp,__be16 port)231 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
232 {
233 	struct udp_tunnel_sock_cfg tunnel_cfg;
234 	struct socket *sock;
235 
236 	sock = bareudp_create_sock(bareudp->net, port);
237 	if (IS_ERR(sock))
238 		return PTR_ERR(sock);
239 
240 	/* Mark socket as an encapsulation socket */
241 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
242 	tunnel_cfg.sk_user_data = bareudp;
243 	tunnel_cfg.encap_type = 1;
244 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
245 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
246 	tunnel_cfg.encap_destroy = NULL;
247 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
248 
249 	/* As the setup_udp_tunnel_sock does not call udp_encap_enable if the
250 	 * socket type is v6 an explicit call to udp_encap_enable is needed.
251 	 */
252 	if (sock->sk->sk_family == AF_INET6)
253 		udp_encap_enable();
254 
255 	rcu_assign_pointer(bareudp->sock, sock);
256 	return 0;
257 }
258 
bareudp_open(struct net_device * dev)259 static int bareudp_open(struct net_device *dev)
260 {
261 	struct bareudp_dev *bareudp = netdev_priv(dev);
262 	int ret = 0;
263 
264 	ret =  bareudp_socket_create(bareudp, bareudp->port);
265 	return ret;
266 }
267 
bareudp_sock_release(struct bareudp_dev * bareudp)268 static void bareudp_sock_release(struct bareudp_dev *bareudp)
269 {
270 	struct socket *sock;
271 
272 	sock = bareudp->sock;
273 	rcu_assign_pointer(bareudp->sock, NULL);
274 	synchronize_net();
275 	udp_tunnel_sock_release(sock);
276 }
277 
bareudp_stop(struct net_device * dev)278 static int bareudp_stop(struct net_device *dev)
279 {
280 	struct bareudp_dev *bareudp = netdev_priv(dev);
281 
282 	bareudp_sock_release(bareudp);
283 	return 0;
284 }
285 
bareudp_xmit_skb(struct sk_buff * skb,struct net_device * dev,struct bareudp_dev * bareudp,const struct ip_tunnel_info * info)286 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
287 			    struct bareudp_dev *bareudp,
288 			    const struct ip_tunnel_info *info)
289 {
290 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
291 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
292 	struct socket *sock = rcu_dereference(bareudp->sock);
293 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
294 	const struct ip_tunnel_key *key = &info->key;
295 	struct rtable *rt;
296 	__be16 sport, df;
297 	int min_headroom;
298 	__u8 tos, ttl;
299 	__be32 saddr;
300 	int err;
301 
302 	if (!sock)
303 		return -ESHUTDOWN;
304 
305 	rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr, info,
306 				    IPPROTO_UDP, use_cache);
307 
308 	if (IS_ERR(rt))
309 		return PTR_ERR(rt);
310 
311 	skb_tunnel_check_pmtu(skb, &rt->dst,
312 			      BAREUDP_IPV4_HLEN + info->options_len, false);
313 
314 	sport = udp_flow_src_port(bareudp->net, skb,
315 				  bareudp->sport_min, USHRT_MAX,
316 				  true);
317 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
318 	ttl = key->ttl;
319 	df = key->tun_flags & TUNNEL_DONT_FRAGMENT ? htons(IP_DF) : 0;
320 	skb_scrub_packet(skb, xnet);
321 
322 	err = -ENOSPC;
323 	if (!skb_pull(skb, skb_network_offset(skb)))
324 		goto free_dst;
325 
326 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
327 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
328 
329 	err = skb_cow_head(skb, min_headroom);
330 	if (unlikely(err))
331 		goto free_dst;
332 
333 	err = udp_tunnel_handle_offloads(skb, udp_sum);
334 	if (err)
335 		goto free_dst;
336 
337 	skb_set_inner_protocol(skb, bareudp->ethertype);
338 	udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
339 			    tos, ttl, df, sport, bareudp->port,
340 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
341 			    !(info->key.tun_flags & TUNNEL_CSUM));
342 	return 0;
343 
344 free_dst:
345 	dst_release(&rt->dst);
346 	return err;
347 }
348 
bareudp6_xmit_skb(struct sk_buff * skb,struct net_device * dev,struct bareudp_dev * bareudp,const struct ip_tunnel_info * info)349 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
350 			     struct bareudp_dev *bareudp,
351 			     const struct ip_tunnel_info *info)
352 {
353 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
354 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
355 	struct socket *sock  = rcu_dereference(bareudp->sock);
356 	bool udp_sum = !!(info->key.tun_flags & TUNNEL_CSUM);
357 	const struct ip_tunnel_key *key = &info->key;
358 	struct dst_entry *dst = NULL;
359 	struct in6_addr saddr, daddr;
360 	int min_headroom;
361 	__u8 prio, ttl;
362 	__be16 sport;
363 	int err;
364 
365 	if (!sock)
366 		return -ESHUTDOWN;
367 
368 	dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock, &saddr, info,
369 				    IPPROTO_UDP, use_cache);
370 	if (IS_ERR(dst))
371 		return PTR_ERR(dst);
372 
373 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
374 			      false);
375 
376 	sport = udp_flow_src_port(bareudp->net, skb,
377 				  bareudp->sport_min, USHRT_MAX,
378 				  true);
379 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
380 	ttl = key->ttl;
381 
382 	skb_scrub_packet(skb, xnet);
383 
384 	err = -ENOSPC;
385 	if (!skb_pull(skb, skb_network_offset(skb)))
386 		goto free_dst;
387 
388 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
389 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
390 
391 	err = skb_cow_head(skb, min_headroom);
392 	if (unlikely(err))
393 		goto free_dst;
394 
395 	err = udp_tunnel_handle_offloads(skb, udp_sum);
396 	if (err)
397 		goto free_dst;
398 
399 	daddr = info->key.u.ipv6.dst;
400 	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
401 			     &saddr, &daddr, prio, ttl,
402 			     info->key.label, sport, bareudp->port,
403 			     !(info->key.tun_flags & TUNNEL_CSUM));
404 	return 0;
405 
406 free_dst:
407 	dst_release(dst);
408 	return err;
409 }
410 
bareudp_proto_valid(struct bareudp_dev * bareudp,__be16 proto)411 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
412 {
413 	if (bareudp->ethertype == proto)
414 		return true;
415 
416 	if (!bareudp->multi_proto_mode)
417 		return false;
418 
419 	if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
420 	    proto == htons(ETH_P_MPLS_MC))
421 		return true;
422 
423 	if (bareudp->ethertype == htons(ETH_P_IP) &&
424 	    proto == htons(ETH_P_IPV6))
425 		return true;
426 
427 	return false;
428 }
429 
bareudp_xmit(struct sk_buff * skb,struct net_device * dev)430 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
431 {
432 	struct bareudp_dev *bareudp = netdev_priv(dev);
433 	struct ip_tunnel_info *info = NULL;
434 	int err;
435 
436 	if (!bareudp_proto_valid(bareudp, skb->protocol)) {
437 		err = -EINVAL;
438 		goto tx_error;
439 	}
440 
441 	info = skb_tunnel_info(skb);
442 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
443 		err = -EINVAL;
444 		goto tx_error;
445 	}
446 
447 	rcu_read_lock();
448 	if (IS_ENABLED(CONFIG_IPV6) && info->mode & IP_TUNNEL_INFO_IPV6)
449 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
450 	else
451 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
452 
453 	rcu_read_unlock();
454 
455 	if (likely(!err))
456 		return NETDEV_TX_OK;
457 tx_error:
458 	dev_kfree_skb(skb);
459 
460 	if (err == -ELOOP)
461 		dev->stats.collisions++;
462 	else if (err == -ENETUNREACH)
463 		dev->stats.tx_carrier_errors++;
464 
465 	dev->stats.tx_errors++;
466 	return NETDEV_TX_OK;
467 }
468 
bareudp_fill_metadata_dst(struct net_device * dev,struct sk_buff * skb)469 static int bareudp_fill_metadata_dst(struct net_device *dev,
470 				     struct sk_buff *skb)
471 {
472 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
473 	struct bareudp_dev *bareudp = netdev_priv(dev);
474 	bool use_cache;
475 
476 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
477 
478 	if (!IS_ENABLED(CONFIG_IPV6) || ip_tunnel_info_af(info) == AF_INET) {
479 		struct rtable *rt;
480 		__be32 saddr;
481 
482 		rt = ip_route_output_tunnel(skb, dev, bareudp->net, &saddr,
483 					    info, IPPROTO_UDP, use_cache);
484 		if (IS_ERR(rt))
485 			return PTR_ERR(rt);
486 
487 		ip_rt_put(rt);
488 		info->key.u.ipv4.src = saddr;
489 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
490 		struct dst_entry *dst;
491 		struct in6_addr saddr;
492 		struct socket *sock = rcu_dereference(bareudp->sock);
493 
494 		dst = ip6_dst_lookup_tunnel(skb, dev, bareudp->net, sock,
495 					    &saddr, info, IPPROTO_UDP,
496 					    use_cache);
497 		if (IS_ERR(dst))
498 			return PTR_ERR(dst);
499 
500 		dst_release(dst);
501 		info->key.u.ipv6.src = saddr;
502 	} else {
503 		return -EINVAL;
504 	}
505 
506 	info->key.tp_src = udp_flow_src_port(bareudp->net, skb,
507 					     bareudp->sport_min,
508 			USHRT_MAX, true);
509 	info->key.tp_dst = bareudp->port;
510 	return 0;
511 }
512 
513 static const struct net_device_ops bareudp_netdev_ops = {
514 	.ndo_init               = bareudp_init,
515 	.ndo_uninit             = bareudp_uninit,
516 	.ndo_open               = bareudp_open,
517 	.ndo_stop               = bareudp_stop,
518 	.ndo_start_xmit         = bareudp_xmit,
519 	.ndo_get_stats64        = ip_tunnel_get_stats64,
520 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
521 };
522 
523 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
524 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
525 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
526 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
527 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
528 };
529 
530 /* Info for udev, that this is a virtual tunnel endpoint */
531 static struct device_type bareudp_type = {
532 	.name = "bareudp",
533 };
534 
535 /* Initialize the device structure. */
bareudp_setup(struct net_device * dev)536 static void bareudp_setup(struct net_device *dev)
537 {
538 	dev->netdev_ops = &bareudp_netdev_ops;
539 	dev->needs_free_netdev = true;
540 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
541 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM;
542 	dev->features    |= NETIF_F_RXCSUM;
543 	dev->features    |= NETIF_F_LLTX;
544 	dev->features    |= NETIF_F_GSO_SOFTWARE;
545 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_RXCSUM;
546 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
547 	dev->hard_header_len = 0;
548 	dev->addr_len = 0;
549 	dev->mtu = ETH_DATA_LEN;
550 	dev->min_mtu = IPV4_MIN_MTU;
551 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
552 	dev->type = ARPHRD_NONE;
553 	netif_keep_dst(dev);
554 	dev->priv_flags |= IFF_NO_QUEUE;
555 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
556 }
557 
bareudp_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)558 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
559 			    struct netlink_ext_ack *extack)
560 {
561 	if (!data) {
562 		NL_SET_ERR_MSG(extack,
563 			       "Not enough attributes provided to perform the operation");
564 		return -EINVAL;
565 	}
566 	return 0;
567 }
568 
bareudp2info(struct nlattr * data[],struct bareudp_conf * conf,struct netlink_ext_ack * extack)569 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
570 			struct netlink_ext_ack *extack)
571 {
572 	memset(conf, 0, sizeof(*conf));
573 
574 	if (!data[IFLA_BAREUDP_PORT]) {
575 		NL_SET_ERR_MSG(extack, "port not specified");
576 		return -EINVAL;
577 	}
578 	if (!data[IFLA_BAREUDP_ETHERTYPE]) {
579 		NL_SET_ERR_MSG(extack, "ethertype not specified");
580 		return -EINVAL;
581 	}
582 
583 	if (data[IFLA_BAREUDP_PORT])
584 		conf->port =  nla_get_u16(data[IFLA_BAREUDP_PORT]);
585 
586 	if (data[IFLA_BAREUDP_ETHERTYPE])
587 		conf->ethertype =  nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
588 
589 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
590 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
591 
592 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
593 		conf->multi_proto_mode = true;
594 
595 	return 0;
596 }
597 
bareudp_find_dev(struct bareudp_net * bn,const struct bareudp_conf * conf)598 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
599 					    const struct bareudp_conf *conf)
600 {
601 	struct bareudp_dev *bareudp, *t = NULL;
602 
603 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
604 		if (conf->port == bareudp->port)
605 			t = bareudp;
606 	}
607 	return t;
608 }
609 
bareudp_configure(struct net * net,struct net_device * dev,struct bareudp_conf * conf)610 static int bareudp_configure(struct net *net, struct net_device *dev,
611 			     struct bareudp_conf *conf)
612 {
613 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
614 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
615 	int err;
616 
617 	bareudp->net = net;
618 	bareudp->dev = dev;
619 	t = bareudp_find_dev(bn, conf);
620 	if (t)
621 		return -EBUSY;
622 
623 	if (conf->multi_proto_mode &&
624 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
625 	     conf->ethertype != htons(ETH_P_IP)))
626 		return -EINVAL;
627 
628 	bareudp->port = conf->port;
629 	bareudp->ethertype = conf->ethertype;
630 	bareudp->sport_min = conf->sport_min;
631 	bareudp->multi_proto_mode = conf->multi_proto_mode;
632 
633 	err = register_netdevice(dev);
634 	if (err)
635 		return err;
636 
637 	list_add(&bareudp->next, &bn->bareudp_list);
638 	return 0;
639 }
640 
bareudp_link_config(struct net_device * dev,struct nlattr * tb[])641 static int bareudp_link_config(struct net_device *dev,
642 			       struct nlattr *tb[])
643 {
644 	int err;
645 
646 	if (tb[IFLA_MTU]) {
647 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
648 		if (err)
649 			return err;
650 	}
651 	return 0;
652 }
653 
bareudp_dellink(struct net_device * dev,struct list_head * head)654 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
655 {
656 	struct bareudp_dev *bareudp = netdev_priv(dev);
657 
658 	list_del(&bareudp->next);
659 	unregister_netdevice_queue(dev, head);
660 }
661 
bareudp_newlink(struct net * net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)662 static int bareudp_newlink(struct net *net, struct net_device *dev,
663 			   struct nlattr *tb[], struct nlattr *data[],
664 			   struct netlink_ext_ack *extack)
665 {
666 	struct bareudp_conf conf;
667 	LIST_HEAD(list_kill);
668 	int err;
669 
670 	err = bareudp2info(data, &conf, extack);
671 	if (err)
672 		return err;
673 
674 	err = bareudp_configure(net, dev, &conf);
675 	if (err)
676 		return err;
677 
678 	err = bareudp_link_config(dev, tb);
679 	if (err)
680 		goto err_unconfig;
681 
682 	return 0;
683 
684 err_unconfig:
685 	bareudp_dellink(dev, &list_kill);
686 	unregister_netdevice_many(&list_kill);
687 	return err;
688 }
689 
bareudp_get_size(const struct net_device * dev)690 static size_t bareudp_get_size(const struct net_device *dev)
691 {
692 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
693 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
694 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
695 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
696 		0;
697 }
698 
bareudp_fill_info(struct sk_buff * skb,const struct net_device * dev)699 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
700 {
701 	struct bareudp_dev *bareudp = netdev_priv(dev);
702 
703 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
704 		goto nla_put_failure;
705 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
706 		goto nla_put_failure;
707 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
708 		goto nla_put_failure;
709 	if (bareudp->multi_proto_mode &&
710 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
711 		goto nla_put_failure;
712 
713 	return 0;
714 
715 nla_put_failure:
716 	return -EMSGSIZE;
717 }
718 
719 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
720 	.kind           = "bareudp",
721 	.maxtype        = IFLA_BAREUDP_MAX,
722 	.policy         = bareudp_policy,
723 	.priv_size      = sizeof(struct bareudp_dev),
724 	.setup          = bareudp_setup,
725 	.validate       = bareudp_validate,
726 	.newlink        = bareudp_newlink,
727 	.dellink        = bareudp_dellink,
728 	.get_size       = bareudp_get_size,
729 	.fill_info      = bareudp_fill_info,
730 };
731 
bareudp_dev_create(struct net * net,const char * name,u8 name_assign_type,struct bareudp_conf * conf)732 struct net_device *bareudp_dev_create(struct net *net, const char *name,
733 				      u8 name_assign_type,
734 				      struct bareudp_conf *conf)
735 {
736 	struct nlattr *tb[IFLA_MAX + 1];
737 	struct net_device *dev;
738 	LIST_HEAD(list_kill);
739 	int err;
740 
741 	memset(tb, 0, sizeof(tb));
742 	dev = rtnl_create_link(net, name, name_assign_type,
743 			       &bareudp_link_ops, tb, NULL);
744 	if (IS_ERR(dev))
745 		return dev;
746 
747 	err = bareudp_configure(net, dev, conf);
748 	if (err) {
749 		free_netdev(dev);
750 		return ERR_PTR(err);
751 	}
752 	err = dev_set_mtu(dev, IP_MAX_MTU - BAREUDP_BASE_HLEN);
753 	if (err)
754 		goto err;
755 
756 	err = rtnl_configure_link(dev, NULL);
757 	if (err < 0)
758 		goto err;
759 
760 	return dev;
761 err:
762 	bareudp_dellink(dev, &list_kill);
763 	unregister_netdevice_many(&list_kill);
764 	return ERR_PTR(err);
765 }
766 EXPORT_SYMBOL_GPL(bareudp_dev_create);
767 
bareudp_init_net(struct net * net)768 static __net_init int bareudp_init_net(struct net *net)
769 {
770 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
771 
772 	INIT_LIST_HEAD(&bn->bareudp_list);
773 	return 0;
774 }
775 
bareudp_destroy_tunnels(struct net * net,struct list_head * head)776 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
777 {
778 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
779 	struct bareudp_dev *bareudp, *next;
780 
781 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
782 		unregister_netdevice_queue(bareudp->dev, head);
783 }
784 
bareudp_exit_batch_net(struct list_head * net_list)785 static void __net_exit bareudp_exit_batch_net(struct list_head *net_list)
786 {
787 	struct net *net;
788 	LIST_HEAD(list);
789 
790 	rtnl_lock();
791 	list_for_each_entry(net, net_list, exit_list)
792 		bareudp_destroy_tunnels(net, &list);
793 
794 	/* unregister the devices gathered above */
795 	unregister_netdevice_many(&list);
796 	rtnl_unlock();
797 }
798 
799 static struct pernet_operations bareudp_net_ops = {
800 	.init = bareudp_init_net,
801 	.exit_batch = bareudp_exit_batch_net,
802 	.id   = &bareudp_net_id,
803 	.size = sizeof(struct bareudp_net),
804 };
805 
bareudp_init_module(void)806 static int __init bareudp_init_module(void)
807 {
808 	int rc;
809 
810 	rc = register_pernet_subsys(&bareudp_net_ops);
811 	if (rc)
812 		goto out1;
813 
814 	rc = rtnl_link_register(&bareudp_link_ops);
815 	if (rc)
816 		goto out2;
817 
818 	return 0;
819 out2:
820 	unregister_pernet_subsys(&bareudp_net_ops);
821 out1:
822 	return rc;
823 }
824 late_initcall(bareudp_init_module);
825 
bareudp_cleanup_module(void)826 static void __exit bareudp_cleanup_module(void)
827 {
828 	rtnl_link_unregister(&bareudp_link_ops);
829 	unregister_pernet_subsys(&bareudp_net_ops);
830 }
831 module_exit(bareudp_cleanup_module);
832 
833 MODULE_ALIAS_RTNL_LINK("bareudp");
834 MODULE_LICENSE("GPL");
835 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
836 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
837