xref: /linux/drivers/net/bareudp.c (revision 9410645520e9b820069761f3450ef6661418e279)
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 
bareudp_udp_encap_recv(struct sock * sk,struct sk_buff * skb)61 static int bareudp_udp_encap_recv(struct sock *sk, struct sk_buff *skb)
62 {
63 	struct metadata_dst *tun_dst = NULL;
64 	IP_TUNNEL_DECLARE_FLAGS(key) = { };
65 	struct bareudp_dev *bareudp;
66 	unsigned short family;
67 	unsigned int len;
68 	__be16 proto;
69 	void *oiph;
70 	int err;
71 	int nh;
72 
73 	bareudp = rcu_dereference_sk_user_data(sk);
74 	if (!bareudp)
75 		goto drop;
76 
77 	if (skb->protocol ==  htons(ETH_P_IP))
78 		family = AF_INET;
79 	else
80 		family = AF_INET6;
81 
82 	if (bareudp->ethertype == htons(ETH_P_IP)) {
83 		__u8 ipversion;
84 
85 		if (skb_copy_bits(skb, BAREUDP_BASE_HLEN, &ipversion,
86 				  sizeof(ipversion))) {
87 			DEV_STATS_INC(bareudp->dev, rx_dropped);
88 			goto drop;
89 		}
90 		ipversion >>= 4;
91 
92 		if (ipversion == 4) {
93 			proto = htons(ETH_P_IP);
94 		} else if (ipversion == 6 && bareudp->multi_proto_mode) {
95 			proto = htons(ETH_P_IPV6);
96 		} else {
97 			DEV_STATS_INC(bareudp->dev, rx_dropped);
98 			goto drop;
99 		}
100 	} else if (bareudp->ethertype == htons(ETH_P_MPLS_UC)) {
101 		struct iphdr *tunnel_hdr;
102 
103 		tunnel_hdr = (struct iphdr *)skb_network_header(skb);
104 		if (tunnel_hdr->version == 4) {
105 			if (!ipv4_is_multicast(tunnel_hdr->daddr)) {
106 				proto = bareudp->ethertype;
107 			} else if (bareudp->multi_proto_mode &&
108 				   ipv4_is_multicast(tunnel_hdr->daddr)) {
109 				proto = htons(ETH_P_MPLS_MC);
110 			} else {
111 				DEV_STATS_INC(bareudp->dev, rx_dropped);
112 				goto drop;
113 			}
114 		} else {
115 			int addr_type;
116 			struct ipv6hdr *tunnel_hdr_v6;
117 
118 			tunnel_hdr_v6 = (struct ipv6hdr *)skb_network_header(skb);
119 			addr_type =
120 			ipv6_addr_type((struct in6_addr *)&tunnel_hdr_v6->daddr);
121 			if (!(addr_type & IPV6_ADDR_MULTICAST)) {
122 				proto = bareudp->ethertype;
123 			} else if (bareudp->multi_proto_mode &&
124 				   (addr_type & IPV6_ADDR_MULTICAST)) {
125 				proto = htons(ETH_P_MPLS_MC);
126 			} else {
127 				DEV_STATS_INC(bareudp->dev, rx_dropped);
128 				goto drop;
129 			}
130 		}
131 	} else {
132 		proto = bareudp->ethertype;
133 	}
134 
135 	if (iptunnel_pull_header(skb, BAREUDP_BASE_HLEN,
136 				 proto,
137 				 !net_eq(bareudp->net,
138 				 dev_net(bareudp->dev)))) {
139 		DEV_STATS_INC(bareudp->dev, rx_dropped);
140 		goto drop;
141 	}
142 
143 	__set_bit(IP_TUNNEL_KEY_BIT, key);
144 
145 	tun_dst = udp_tun_rx_dst(skb, family, key, 0, 0);
146 	if (!tun_dst) {
147 		DEV_STATS_INC(bareudp->dev, rx_dropped);
148 		goto drop;
149 	}
150 	skb_dst_set(skb, &tun_dst->dst);
151 	skb->dev = bareudp->dev;
152 	skb_reset_mac_header(skb);
153 
154 	/* Save offset of outer header relative to skb->head,
155 	 * because we are going to reset the network header to the inner header
156 	 * and might change skb->head.
157 	 */
158 	nh = skb_network_header(skb) - skb->head;
159 
160 	skb_reset_network_header(skb);
161 
162 	if (!pskb_inet_may_pull(skb)) {
163 		DEV_STATS_INC(bareudp->dev, rx_length_errors);
164 		DEV_STATS_INC(bareudp->dev, rx_errors);
165 		goto drop;
166 	}
167 
168 	/* Get the outer header. */
169 	oiph = skb->head + nh;
170 
171 	if (!ipv6_mod_enabled() || family == AF_INET)
172 		err = IP_ECN_decapsulate(oiph, skb);
173 	else
174 		err = IP6_ECN_decapsulate(oiph, skb);
175 
176 	if (unlikely(err)) {
177 		if (log_ecn_error) {
178 			if  (!ipv6_mod_enabled() || family == AF_INET)
179 				net_info_ratelimited("non-ECT from %pI4 "
180 						     "with TOS=%#x\n",
181 						     &((struct iphdr *)oiph)->saddr,
182 						     ((struct iphdr *)oiph)->tos);
183 			else
184 				net_info_ratelimited("non-ECT from %pI6\n",
185 						     &((struct ipv6hdr *)oiph)->saddr);
186 		}
187 		if (err > 1) {
188 			DEV_STATS_INC(bareudp->dev, rx_frame_errors);
189 			DEV_STATS_INC(bareudp->dev, rx_errors);
190 			goto drop;
191 		}
192 	}
193 
194 	len = skb->len;
195 	err = gro_cells_receive(&bareudp->gro_cells, skb);
196 	if (likely(err == NET_RX_SUCCESS))
197 		dev_sw_netstats_rx_add(bareudp->dev, len);
198 
199 	return 0;
200 drop:
201 	/* Consume bad packet */
202 	kfree_skb(skb);
203 
204 	return 0;
205 }
206 
bareudp_err_lookup(struct sock * sk,struct sk_buff * skb)207 static int bareudp_err_lookup(struct sock *sk, struct sk_buff *skb)
208 {
209 	return 0;
210 }
211 
bareudp_init(struct net_device * dev)212 static int bareudp_init(struct net_device *dev)
213 {
214 	struct bareudp_dev *bareudp = netdev_priv(dev);
215 	int err;
216 
217 	err = gro_cells_init(&bareudp->gro_cells, dev);
218 	if (err)
219 		return err;
220 
221 	return 0;
222 }
223 
bareudp_uninit(struct net_device * dev)224 static void bareudp_uninit(struct net_device *dev)
225 {
226 	struct bareudp_dev *bareudp = netdev_priv(dev);
227 
228 	gro_cells_destroy(&bareudp->gro_cells);
229 }
230 
bareudp_create_sock(struct net * net,__be16 port)231 static struct socket *bareudp_create_sock(struct net *net, __be16 port)
232 {
233 	struct udp_port_cfg udp_conf;
234 	struct socket *sock;
235 	int err;
236 
237 	memset(&udp_conf, 0, sizeof(udp_conf));
238 
239 	if (ipv6_mod_enabled())
240 		udp_conf.family = AF_INET6;
241 	else
242 		udp_conf.family = AF_INET;
243 
244 	udp_conf.local_udp_port = port;
245 	/* Open UDP socket */
246 	err = udp_sock_create(net, &udp_conf, &sock);
247 	if (err < 0)
248 		return ERR_PTR(err);
249 
250 	udp_allow_gso(sock->sk);
251 	return sock;
252 }
253 
254 /* Create new listen socket if needed */
bareudp_socket_create(struct bareudp_dev * bareudp,__be16 port)255 static int bareudp_socket_create(struct bareudp_dev *bareudp, __be16 port)
256 {
257 	struct udp_tunnel_sock_cfg tunnel_cfg;
258 	struct socket *sock;
259 
260 	sock = bareudp_create_sock(bareudp->net, port);
261 	if (IS_ERR(sock))
262 		return PTR_ERR(sock);
263 
264 	/* Mark socket as an encapsulation socket */
265 	memset(&tunnel_cfg, 0, sizeof(tunnel_cfg));
266 	tunnel_cfg.sk_user_data = bareudp;
267 	tunnel_cfg.encap_type = 1;
268 	tunnel_cfg.encap_rcv = bareudp_udp_encap_recv;
269 	tunnel_cfg.encap_err_lookup = bareudp_err_lookup;
270 	tunnel_cfg.encap_destroy = NULL;
271 	setup_udp_tunnel_sock(bareudp->net, sock, &tunnel_cfg);
272 
273 	rcu_assign_pointer(bareudp->sock, sock);
274 	return 0;
275 }
276 
bareudp_open(struct net_device * dev)277 static int bareudp_open(struct net_device *dev)
278 {
279 	struct bareudp_dev *bareudp = netdev_priv(dev);
280 	int ret = 0;
281 
282 	ret =  bareudp_socket_create(bareudp, bareudp->port);
283 	return ret;
284 }
285 
bareudp_sock_release(struct bareudp_dev * bareudp)286 static void bareudp_sock_release(struct bareudp_dev *bareudp)
287 {
288 	struct socket *sock;
289 
290 	sock = bareudp->sock;
291 	rcu_assign_pointer(bareudp->sock, NULL);
292 	synchronize_net();
293 	udp_tunnel_sock_release(sock);
294 }
295 
bareudp_stop(struct net_device * dev)296 static int bareudp_stop(struct net_device *dev)
297 {
298 	struct bareudp_dev *bareudp = netdev_priv(dev);
299 
300 	bareudp_sock_release(bareudp);
301 	return 0;
302 }
303 
bareudp_xmit_skb(struct sk_buff * skb,struct net_device * dev,struct bareudp_dev * bareudp,const struct ip_tunnel_info * info)304 static int bareudp_xmit_skb(struct sk_buff *skb, struct net_device *dev,
305 			    struct bareudp_dev *bareudp,
306 			    const struct ip_tunnel_info *info)
307 {
308 	bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
309 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
310 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
311 	struct socket *sock = rcu_dereference(bareudp->sock);
312 	const struct ip_tunnel_key *key = &info->key;
313 	struct rtable *rt;
314 	__be16 sport, df;
315 	int min_headroom;
316 	__u8 tos, ttl;
317 	__be32 saddr;
318 	int err;
319 
320 	if (!skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
321 		return -EINVAL;
322 
323 	if (!sock)
324 		return -ESHUTDOWN;
325 
326 	sport = udp_flow_src_port(bareudp->net, skb,
327 				  bareudp->sport_min, USHRT_MAX,
328 				  true);
329 	rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr, &info->key,
330 				   sport, bareudp->port, key->tos,
331 				   use_cache ?
332 				   (struct dst_cache *)&info->dst_cache : NULL);
333 
334 	if (IS_ERR(rt))
335 		return PTR_ERR(rt);
336 
337 	skb_tunnel_check_pmtu(skb, &rt->dst,
338 			      BAREUDP_IPV4_HLEN + info->options_len, false);
339 
340 	tos = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
341 	ttl = key->ttl;
342 	df = test_bit(IP_TUNNEL_DONT_FRAGMENT_BIT, key->tun_flags) ?
343 	     htons(IP_DF) : 0;
344 	skb_scrub_packet(skb, xnet);
345 
346 	err = -ENOSPC;
347 	if (!skb_pull(skb, skb_network_offset(skb)))
348 		goto free_dst;
349 
350 	min_headroom = LL_RESERVED_SPACE(rt->dst.dev) + rt->dst.header_len +
351 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct iphdr);
352 
353 	err = skb_cow_head(skb, min_headroom);
354 	if (unlikely(err))
355 		goto free_dst;
356 
357 	err = udp_tunnel_handle_offloads(skb, udp_sum);
358 	if (err)
359 		goto free_dst;
360 
361 	skb_set_inner_protocol(skb, bareudp->ethertype);
362 	udp_tunnel_xmit_skb(rt, sock->sk, skb, saddr, info->key.u.ipv4.dst,
363 			    tos, ttl, df, sport, bareudp->port,
364 			    !net_eq(bareudp->net, dev_net(bareudp->dev)),
365 			    !test_bit(IP_TUNNEL_CSUM_BIT,
366 				      info->key.tun_flags));
367 	return 0;
368 
369 free_dst:
370 	dst_release(&rt->dst);
371 	return err;
372 }
373 
bareudp6_xmit_skb(struct sk_buff * skb,struct net_device * dev,struct bareudp_dev * bareudp,const struct ip_tunnel_info * info)374 static int bareudp6_xmit_skb(struct sk_buff *skb, struct net_device *dev,
375 			     struct bareudp_dev *bareudp,
376 			     const struct ip_tunnel_info *info)
377 {
378 	bool udp_sum = test_bit(IP_TUNNEL_CSUM_BIT, info->key.tun_flags);
379 	bool xnet = !net_eq(bareudp->net, dev_net(bareudp->dev));
380 	bool use_cache = ip_tunnel_dst_cache_usable(skb, info);
381 	struct socket *sock  = rcu_dereference(bareudp->sock);
382 	const struct ip_tunnel_key *key = &info->key;
383 	struct dst_entry *dst = NULL;
384 	struct in6_addr saddr, daddr;
385 	int min_headroom;
386 	__u8 prio, ttl;
387 	__be16 sport;
388 	int err;
389 
390 	if (!skb_vlan_inet_prepare(skb, skb->protocol != htons(ETH_P_TEB)))
391 		return -EINVAL;
392 
393 	if (!sock)
394 		return -ESHUTDOWN;
395 
396 	sport = udp_flow_src_port(bareudp->net, skb,
397 				  bareudp->sport_min, USHRT_MAX,
398 				  true);
399 	dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock, 0, &saddr,
400 				     key, sport, bareudp->port, key->tos,
401 				     use_cache ?
402 				     (struct dst_cache *) &info->dst_cache : NULL);
403 	if (IS_ERR(dst))
404 		return PTR_ERR(dst);
405 
406 	skb_tunnel_check_pmtu(skb, dst, BAREUDP_IPV6_HLEN + info->options_len,
407 			      false);
408 
409 	prio = ip_tunnel_ecn_encap(key->tos, ip_hdr(skb), skb);
410 	ttl = key->ttl;
411 
412 	skb_scrub_packet(skb, xnet);
413 
414 	err = -ENOSPC;
415 	if (!skb_pull(skb, skb_network_offset(skb)))
416 		goto free_dst;
417 
418 	min_headroom = LL_RESERVED_SPACE(dst->dev) + dst->header_len +
419 		BAREUDP_BASE_HLEN + info->options_len + sizeof(struct ipv6hdr);
420 
421 	err = skb_cow_head(skb, min_headroom);
422 	if (unlikely(err))
423 		goto free_dst;
424 
425 	err = udp_tunnel_handle_offloads(skb, udp_sum);
426 	if (err)
427 		goto free_dst;
428 
429 	daddr = info->key.u.ipv6.dst;
430 	udp_tunnel6_xmit_skb(dst, sock->sk, skb, dev,
431 			     &saddr, &daddr, prio, ttl,
432 			     info->key.label, sport, bareudp->port,
433 			     !test_bit(IP_TUNNEL_CSUM_BIT,
434 				       info->key.tun_flags));
435 	return 0;
436 
437 free_dst:
438 	dst_release(dst);
439 	return err;
440 }
441 
bareudp_proto_valid(struct bareudp_dev * bareudp,__be16 proto)442 static bool bareudp_proto_valid(struct bareudp_dev *bareudp, __be16 proto)
443 {
444 	if (bareudp->ethertype == proto)
445 		return true;
446 
447 	if (!bareudp->multi_proto_mode)
448 		return false;
449 
450 	if (bareudp->ethertype == htons(ETH_P_MPLS_UC) &&
451 	    proto == htons(ETH_P_MPLS_MC))
452 		return true;
453 
454 	if (bareudp->ethertype == htons(ETH_P_IP) &&
455 	    proto == htons(ETH_P_IPV6))
456 		return true;
457 
458 	return false;
459 }
460 
bareudp_xmit(struct sk_buff * skb,struct net_device * dev)461 static netdev_tx_t bareudp_xmit(struct sk_buff *skb, struct net_device *dev)
462 {
463 	struct bareudp_dev *bareudp = netdev_priv(dev);
464 	struct ip_tunnel_info *info = NULL;
465 	int err;
466 
467 	if (!bareudp_proto_valid(bareudp, skb->protocol)) {
468 		err = -EINVAL;
469 		goto tx_error;
470 	}
471 
472 	info = skb_tunnel_info(skb);
473 	if (unlikely(!info || !(info->mode & IP_TUNNEL_INFO_TX))) {
474 		err = -EINVAL;
475 		goto tx_error;
476 	}
477 
478 	rcu_read_lock();
479 	if (ipv6_mod_enabled() && info->mode & IP_TUNNEL_INFO_IPV6)
480 		err = bareudp6_xmit_skb(skb, dev, bareudp, info);
481 	else
482 		err = bareudp_xmit_skb(skb, dev, bareudp, info);
483 
484 	rcu_read_unlock();
485 
486 	if (likely(!err))
487 		return NETDEV_TX_OK;
488 tx_error:
489 	dev_kfree_skb(skb);
490 
491 	if (err == -ELOOP)
492 		DEV_STATS_INC(dev, collisions);
493 	else if (err == -ENETUNREACH)
494 		DEV_STATS_INC(dev, tx_carrier_errors);
495 
496 	DEV_STATS_INC(dev, tx_errors);
497 	return NETDEV_TX_OK;
498 }
499 
bareudp_fill_metadata_dst(struct net_device * dev,struct sk_buff * skb)500 static int bareudp_fill_metadata_dst(struct net_device *dev,
501 				     struct sk_buff *skb)
502 {
503 	struct ip_tunnel_info *info = skb_tunnel_info(skb);
504 	struct bareudp_dev *bareudp = netdev_priv(dev);
505 	bool use_cache;
506 	__be16 sport;
507 
508 	use_cache = ip_tunnel_dst_cache_usable(skb, info);
509 	sport = udp_flow_src_port(bareudp->net, skb,
510 				  bareudp->sport_min, USHRT_MAX,
511 				  true);
512 
513 	if (!ipv6_mod_enabled() || ip_tunnel_info_af(info) == AF_INET) {
514 		struct rtable *rt;
515 		__be32 saddr;
516 
517 		rt = udp_tunnel_dst_lookup(skb, dev, bareudp->net, 0, &saddr,
518 					   &info->key, sport, bareudp->port,
519 					   info->key.tos,
520 					   use_cache ? &info->dst_cache : NULL);
521 		if (IS_ERR(rt))
522 			return PTR_ERR(rt);
523 
524 		ip_rt_put(rt);
525 		info->key.u.ipv4.src = saddr;
526 	} else if (ip_tunnel_info_af(info) == AF_INET6) {
527 		struct dst_entry *dst;
528 		struct in6_addr saddr;
529 		struct socket *sock = rcu_dereference(bareudp->sock);
530 
531 		dst = udp_tunnel6_dst_lookup(skb, dev, bareudp->net, sock,
532 					     0, &saddr, &info->key,
533 					     sport, bareudp->port, info->key.tos,
534 					     use_cache ? &info->dst_cache : NULL);
535 		if (IS_ERR(dst))
536 			return PTR_ERR(dst);
537 
538 		dst_release(dst);
539 		info->key.u.ipv6.src = saddr;
540 	} else {
541 		return -EINVAL;
542 	}
543 
544 	info->key.tp_src = sport;
545 	info->key.tp_dst = bareudp->port;
546 	return 0;
547 }
548 
549 static const struct net_device_ops bareudp_netdev_ops = {
550 	.ndo_init               = bareudp_init,
551 	.ndo_uninit             = bareudp_uninit,
552 	.ndo_open               = bareudp_open,
553 	.ndo_stop               = bareudp_stop,
554 	.ndo_start_xmit         = bareudp_xmit,
555 	.ndo_fill_metadata_dst  = bareudp_fill_metadata_dst,
556 };
557 
558 static const struct nla_policy bareudp_policy[IFLA_BAREUDP_MAX + 1] = {
559 	[IFLA_BAREUDP_PORT]                = { .type = NLA_U16 },
560 	[IFLA_BAREUDP_ETHERTYPE]	   = { .type = NLA_U16 },
561 	[IFLA_BAREUDP_SRCPORT_MIN]         = { .type = NLA_U16 },
562 	[IFLA_BAREUDP_MULTIPROTO_MODE]     = { .type = NLA_FLAG },
563 };
564 
565 /* Info for udev, that this is a virtual tunnel endpoint */
566 static const struct device_type bareudp_type = {
567 	.name = "bareudp",
568 };
569 
570 /* Initialize the device structure. */
bareudp_setup(struct net_device * dev)571 static void bareudp_setup(struct net_device *dev)
572 {
573 	dev->netdev_ops = &bareudp_netdev_ops;
574 	dev->needs_free_netdev = true;
575 	SET_NETDEV_DEVTYPE(dev, &bareudp_type);
576 	dev->features    |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
577 	dev->features    |= NETIF_F_RXCSUM;
578 	dev->features    |= NETIF_F_GSO_SOFTWARE;
579 	dev->hw_features |= NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_FRAGLIST;
580 	dev->hw_features |= NETIF_F_RXCSUM;
581 	dev->hw_features |= NETIF_F_GSO_SOFTWARE;
582 	dev->hard_header_len = 0;
583 	dev->addr_len = 0;
584 	dev->mtu = ETH_DATA_LEN;
585 	dev->min_mtu = IPV4_MIN_MTU;
586 	dev->max_mtu = IP_MAX_MTU - BAREUDP_BASE_HLEN;
587 	dev->type = ARPHRD_NONE;
588 	netif_keep_dst(dev);
589 	dev->priv_flags |= IFF_NO_QUEUE;
590 	dev->lltx = true;
591 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
592 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
593 }
594 
bareudp_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)595 static int bareudp_validate(struct nlattr *tb[], struct nlattr *data[],
596 			    struct netlink_ext_ack *extack)
597 {
598 	if (!data) {
599 		NL_SET_ERR_MSG(extack,
600 			       "Not enough attributes provided to perform the operation");
601 		return -EINVAL;
602 	}
603 	return 0;
604 }
605 
bareudp2info(struct nlattr * data[],struct bareudp_conf * conf,struct netlink_ext_ack * extack)606 static int bareudp2info(struct nlattr *data[], struct bareudp_conf *conf,
607 			struct netlink_ext_ack *extack)
608 {
609 	memset(conf, 0, sizeof(*conf));
610 
611 	if (!data[IFLA_BAREUDP_PORT]) {
612 		NL_SET_ERR_MSG(extack, "port not specified");
613 		return -EINVAL;
614 	}
615 	if (!data[IFLA_BAREUDP_ETHERTYPE]) {
616 		NL_SET_ERR_MSG(extack, "ethertype not specified");
617 		return -EINVAL;
618 	}
619 
620 	conf->port = nla_get_u16(data[IFLA_BAREUDP_PORT]);
621 	conf->ethertype = nla_get_u16(data[IFLA_BAREUDP_ETHERTYPE]);
622 
623 	if (data[IFLA_BAREUDP_SRCPORT_MIN])
624 		conf->sport_min =  nla_get_u16(data[IFLA_BAREUDP_SRCPORT_MIN]);
625 
626 	if (data[IFLA_BAREUDP_MULTIPROTO_MODE])
627 		conf->multi_proto_mode = true;
628 
629 	return 0;
630 }
631 
bareudp_find_dev(struct bareudp_net * bn,const struct bareudp_conf * conf)632 static struct bareudp_dev *bareudp_find_dev(struct bareudp_net *bn,
633 					    const struct bareudp_conf *conf)
634 {
635 	struct bareudp_dev *bareudp, *t = NULL;
636 
637 	list_for_each_entry(bareudp, &bn->bareudp_list, next) {
638 		if (conf->port == bareudp->port)
639 			t = bareudp;
640 	}
641 	return t;
642 }
643 
bareudp_configure(struct net * net,struct net_device * dev,struct bareudp_conf * conf,struct netlink_ext_ack * extack)644 static int bareudp_configure(struct net *net, struct net_device *dev,
645 			     struct bareudp_conf *conf,
646 			     struct netlink_ext_ack *extack)
647 {
648 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
649 	struct bareudp_dev *t, *bareudp = netdev_priv(dev);
650 	int err;
651 
652 	bareudp->net = net;
653 	bareudp->dev = dev;
654 	t = bareudp_find_dev(bn, conf);
655 	if (t) {
656 		NL_SET_ERR_MSG(extack, "Another bareudp device using the same port already exists");
657 		return -EBUSY;
658 	}
659 
660 	if (conf->multi_proto_mode &&
661 	    (conf->ethertype != htons(ETH_P_MPLS_UC) &&
662 	     conf->ethertype != htons(ETH_P_IP))) {
663 		NL_SET_ERR_MSG(extack, "Cannot set multiproto mode for this ethertype (only IPv4 and unicast MPLS are supported)");
664 		return -EINVAL;
665 	}
666 
667 	bareudp->port = conf->port;
668 	bareudp->ethertype = conf->ethertype;
669 	bareudp->sport_min = conf->sport_min;
670 	bareudp->multi_proto_mode = conf->multi_proto_mode;
671 
672 	err = register_netdevice(dev);
673 	if (err)
674 		return err;
675 
676 	list_add(&bareudp->next, &bn->bareudp_list);
677 	return 0;
678 }
679 
bareudp_link_config(struct net_device * dev,struct nlattr * tb[])680 static int bareudp_link_config(struct net_device *dev,
681 			       struct nlattr *tb[])
682 {
683 	int err;
684 
685 	if (tb[IFLA_MTU]) {
686 		err = dev_set_mtu(dev, nla_get_u32(tb[IFLA_MTU]));
687 		if (err)
688 			return err;
689 	}
690 	return 0;
691 }
692 
bareudp_dellink(struct net_device * dev,struct list_head * head)693 static void bareudp_dellink(struct net_device *dev, struct list_head *head)
694 {
695 	struct bareudp_dev *bareudp = netdev_priv(dev);
696 
697 	list_del(&bareudp->next);
698 	unregister_netdevice_queue(dev, head);
699 }
700 
bareudp_newlink(struct net * net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)701 static int bareudp_newlink(struct net *net, struct net_device *dev,
702 			   struct nlattr *tb[], struct nlattr *data[],
703 			   struct netlink_ext_ack *extack)
704 {
705 	struct bareudp_conf conf;
706 	int err;
707 
708 	err = bareudp2info(data, &conf, extack);
709 	if (err)
710 		return err;
711 
712 	err = bareudp_configure(net, dev, &conf, extack);
713 	if (err)
714 		return err;
715 
716 	err = bareudp_link_config(dev, tb);
717 	if (err)
718 		goto err_unconfig;
719 
720 	return 0;
721 
722 err_unconfig:
723 	bareudp_dellink(dev, NULL);
724 	return err;
725 }
726 
bareudp_get_size(const struct net_device * dev)727 static size_t bareudp_get_size(const struct net_device *dev)
728 {
729 	return  nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_PORT */
730 		nla_total_size(sizeof(__be16)) +  /* IFLA_BAREUDP_ETHERTYPE */
731 		nla_total_size(sizeof(__u16))  +  /* IFLA_BAREUDP_SRCPORT_MIN */
732 		nla_total_size(0)              +  /* IFLA_BAREUDP_MULTIPROTO_MODE */
733 		0;
734 }
735 
bareudp_fill_info(struct sk_buff * skb,const struct net_device * dev)736 static int bareudp_fill_info(struct sk_buff *skb, const struct net_device *dev)
737 {
738 	struct bareudp_dev *bareudp = netdev_priv(dev);
739 
740 	if (nla_put_be16(skb, IFLA_BAREUDP_PORT, bareudp->port))
741 		goto nla_put_failure;
742 	if (nla_put_be16(skb, IFLA_BAREUDP_ETHERTYPE, bareudp->ethertype))
743 		goto nla_put_failure;
744 	if (nla_put_u16(skb, IFLA_BAREUDP_SRCPORT_MIN, bareudp->sport_min))
745 		goto nla_put_failure;
746 	if (bareudp->multi_proto_mode &&
747 	    nla_put_flag(skb, IFLA_BAREUDP_MULTIPROTO_MODE))
748 		goto nla_put_failure;
749 
750 	return 0;
751 
752 nla_put_failure:
753 	return -EMSGSIZE;
754 }
755 
756 static struct rtnl_link_ops bareudp_link_ops __read_mostly = {
757 	.kind           = "bareudp",
758 	.maxtype        = IFLA_BAREUDP_MAX,
759 	.policy         = bareudp_policy,
760 	.priv_size      = sizeof(struct bareudp_dev),
761 	.setup          = bareudp_setup,
762 	.validate       = bareudp_validate,
763 	.newlink        = bareudp_newlink,
764 	.dellink        = bareudp_dellink,
765 	.get_size       = bareudp_get_size,
766 	.fill_info      = bareudp_fill_info,
767 };
768 
bareudp_init_net(struct net * net)769 static __net_init int bareudp_init_net(struct net *net)
770 {
771 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
772 
773 	INIT_LIST_HEAD(&bn->bareudp_list);
774 	return 0;
775 }
776 
bareudp_destroy_tunnels(struct net * net,struct list_head * head)777 static void bareudp_destroy_tunnels(struct net *net, struct list_head *head)
778 {
779 	struct bareudp_net *bn = net_generic(net, bareudp_net_id);
780 	struct bareudp_dev *bareudp, *next;
781 
782 	list_for_each_entry_safe(bareudp, next, &bn->bareudp_list, next)
783 		unregister_netdevice_queue(bareudp->dev, head);
784 }
785 
bareudp_exit_batch_rtnl(struct list_head * net_list,struct list_head * dev_kill_list)786 static void __net_exit bareudp_exit_batch_rtnl(struct list_head *net_list,
787 					       struct list_head *dev_kill_list)
788 {
789 	struct net *net;
790 
791 	list_for_each_entry(net, net_list, exit_list)
792 		bareudp_destroy_tunnels(net, dev_kill_list);
793 }
794 
795 static struct pernet_operations bareudp_net_ops = {
796 	.init = bareudp_init_net,
797 	.exit_batch_rtnl = bareudp_exit_batch_rtnl,
798 	.id   = &bareudp_net_id,
799 	.size = sizeof(struct bareudp_net),
800 };
801 
bareudp_init_module(void)802 static int __init bareudp_init_module(void)
803 {
804 	int rc;
805 
806 	rc = register_pernet_subsys(&bareudp_net_ops);
807 	if (rc)
808 		goto out1;
809 
810 	rc = rtnl_link_register(&bareudp_link_ops);
811 	if (rc)
812 		goto out2;
813 
814 	return 0;
815 out2:
816 	unregister_pernet_subsys(&bareudp_net_ops);
817 out1:
818 	return rc;
819 }
820 late_initcall(bareudp_init_module);
821 
bareudp_cleanup_module(void)822 static void __exit bareudp_cleanup_module(void)
823 {
824 	rtnl_link_unregister(&bareudp_link_ops);
825 	unregister_pernet_subsys(&bareudp_net_ops);
826 }
827 module_exit(bareudp_cleanup_module);
828 
829 MODULE_ALIAS_RTNL_LINK("bareudp");
830 MODULE_LICENSE("GPL");
831 MODULE_AUTHOR("Martin Varghese <martin.varghese@nokia.com>");
832 MODULE_DESCRIPTION("Interface driver for UDP encapsulated traffic");
833