xref: /openbmc/linux/drivers/net/gtp.c (revision 4f6cce39)
1 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060
2  *
3  * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
4  * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
5  *
6  * Author: Harald Welte <hwelte@sysmocom.de>
7  *	   Pablo Neira Ayuso <pablo@netfilter.org>
8  *	   Andreas Schultz <aschultz@travelping.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * as published by the Free Software Foundation; either version
13  * 2 of the License, or (at your option) any later version.
14  */
15 
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17 
18 #include <linux/module.h>
19 #include <linux/skbuff.h>
20 #include <linux/udp.h>
21 #include <linux/rculist.h>
22 #include <linux/jhash.h>
23 #include <linux/if_tunnel.h>
24 #include <linux/net.h>
25 #include <linux/file.h>
26 #include <linux/gtp.h>
27 
28 #include <net/net_namespace.h>
29 #include <net/protocol.h>
30 #include <net/ip.h>
31 #include <net/udp.h>
32 #include <net/udp_tunnel.h>
33 #include <net/icmp.h>
34 #include <net/xfrm.h>
35 #include <net/genetlink.h>
36 #include <net/netns/generic.h>
37 #include <net/gtp.h>
38 
39 /* An active session for the subscriber. */
40 struct pdp_ctx {
41 	struct hlist_node	hlist_tid;
42 	struct hlist_node	hlist_addr;
43 
44 	union {
45 		u64		tid;
46 		struct {
47 			u64	tid;
48 			u16	flow;
49 		} v0;
50 		struct {
51 			u32	i_tei;
52 			u32	o_tei;
53 		} v1;
54 	} u;
55 	u8			gtp_version;
56 	u16			af;
57 
58 	struct in_addr		ms_addr_ip4;
59 	struct in_addr		sgsn_addr_ip4;
60 
61 	atomic_t		tx_seq;
62 	struct rcu_head		rcu_head;
63 };
64 
65 /* One instance of the GTP device. */
66 struct gtp_dev {
67 	struct list_head	list;
68 
69 	struct socket		*sock0;
70 	struct socket		*sock1u;
71 
72 	struct net_device	*dev;
73 
74 	unsigned int		hash_size;
75 	struct hlist_head	*tid_hash;
76 	struct hlist_head	*addr_hash;
77 };
78 
79 static unsigned int gtp_net_id __read_mostly;
80 
81 struct gtp_net {
82 	struct list_head gtp_dev_list;
83 };
84 
85 static u32 gtp_h_initval;
86 
87 static inline u32 gtp0_hashfn(u64 tid)
88 {
89 	u32 *tid32 = (u32 *) &tid;
90 	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
91 }
92 
93 static inline u32 gtp1u_hashfn(u32 tid)
94 {
95 	return jhash_1word(tid, gtp_h_initval);
96 }
97 
98 static inline u32 ipv4_hashfn(__be32 ip)
99 {
100 	return jhash_1word((__force u32)ip, gtp_h_initval);
101 }
102 
103 /* Resolve a PDP context structure based on the 64bit TID. */
104 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
105 {
106 	struct hlist_head *head;
107 	struct pdp_ctx *pdp;
108 
109 	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
110 
111 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
112 		if (pdp->gtp_version == GTP_V0 &&
113 		    pdp->u.v0.tid == tid)
114 			return pdp;
115 	}
116 	return NULL;
117 }
118 
119 /* Resolve a PDP context structure based on the 32bit TEI. */
120 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
121 {
122 	struct hlist_head *head;
123 	struct pdp_ctx *pdp;
124 
125 	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
126 
127 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
128 		if (pdp->gtp_version == GTP_V1 &&
129 		    pdp->u.v1.i_tei == tid)
130 			return pdp;
131 	}
132 	return NULL;
133 }
134 
135 /* Resolve a PDP context based on IPv4 address of MS. */
136 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
137 {
138 	struct hlist_head *head;
139 	struct pdp_ctx *pdp;
140 
141 	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
142 
143 	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
144 		if (pdp->af == AF_INET &&
145 		    pdp->ms_addr_ip4.s_addr == ms_addr)
146 			return pdp;
147 	}
148 
149 	return NULL;
150 }
151 
152 static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
153 				  unsigned int hdrlen)
154 {
155 	struct iphdr *iph;
156 
157 	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
158 		return false;
159 
160 	iph = (struct iphdr *)(skb->data + hdrlen);
161 
162 	return iph->saddr == pctx->ms_addr_ip4.s_addr;
163 }
164 
165 /* Check if the inner IP source address in this packet is assigned to any
166  * existing mobile subscriber.
167  */
168 static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
169 			     unsigned int hdrlen)
170 {
171 	switch (ntohs(skb->protocol)) {
172 	case ETH_P_IP:
173 		return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
174 	}
175 	return false;
176 }
177 
178 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
179 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
180 			       bool xnet)
181 {
182 	unsigned int hdrlen = sizeof(struct udphdr) +
183 			      sizeof(struct gtp0_header);
184 	struct gtp0_header *gtp0;
185 	struct pdp_ctx *pctx;
186 
187 	if (!pskb_may_pull(skb, hdrlen))
188 		return -1;
189 
190 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
191 
192 	if ((gtp0->flags >> 5) != GTP_V0)
193 		return 1;
194 
195 	if (gtp0->type != GTP_TPDU)
196 		return 1;
197 
198 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
199 	if (!pctx) {
200 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
201 		return 1;
202 	}
203 
204 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
205 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
206 		return 1;
207 	}
208 
209 	/* Get rid of the GTP + UDP headers. */
210 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
211 }
212 
213 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
214 				bool xnet)
215 {
216 	unsigned int hdrlen = sizeof(struct udphdr) +
217 			      sizeof(struct gtp1_header);
218 	struct gtp1_header *gtp1;
219 	struct pdp_ctx *pctx;
220 
221 	if (!pskb_may_pull(skb, hdrlen))
222 		return -1;
223 
224 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
225 
226 	if ((gtp1->flags >> 5) != GTP_V1)
227 		return 1;
228 
229 	if (gtp1->type != GTP_TPDU)
230 		return 1;
231 
232 	/* From 29.060: "This field shall be present if and only if any one or
233 	 * more of the S, PN and E flags are set.".
234 	 *
235 	 * If any of the bit is set, then the remaining ones also have to be
236 	 * set.
237 	 */
238 	if (gtp1->flags & GTP1_F_MASK)
239 		hdrlen += 4;
240 
241 	/* Make sure the header is larger enough, including extensions. */
242 	if (!pskb_may_pull(skb, hdrlen))
243 		return -1;
244 
245 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
246 
247 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
248 	if (!pctx) {
249 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
250 		return 1;
251 	}
252 
253 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
254 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
255 		return 1;
256 	}
257 
258 	/* Get rid of the GTP + UDP headers. */
259 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
260 }
261 
262 static void gtp_encap_disable(struct gtp_dev *gtp)
263 {
264 	if (gtp->sock0 && gtp->sock0->sk) {
265 		udp_sk(gtp->sock0->sk)->encap_type = 0;
266 		rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
267 	}
268 	if (gtp->sock1u && gtp->sock1u->sk) {
269 		udp_sk(gtp->sock1u->sk)->encap_type = 0;
270 		rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
271 	}
272 
273 	gtp->sock0 = NULL;
274 	gtp->sock1u = NULL;
275 }
276 
277 static void gtp_encap_destroy(struct sock *sk)
278 {
279 	struct gtp_dev *gtp;
280 
281 	gtp = rcu_dereference_sk_user_data(sk);
282 	if (gtp)
283 		gtp_encap_disable(gtp);
284 }
285 
286 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
287  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
288  */
289 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
290 {
291 	struct pcpu_sw_netstats *stats;
292 	struct gtp_dev *gtp;
293 	bool xnet;
294 	int ret;
295 
296 	gtp = rcu_dereference_sk_user_data(sk);
297 	if (!gtp)
298 		return 1;
299 
300 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
301 
302 	xnet = !net_eq(sock_net(sk), dev_net(gtp->dev));
303 
304 	switch (udp_sk(sk)->encap_type) {
305 	case UDP_ENCAP_GTP0:
306 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
307 		ret = gtp0_udp_encap_recv(gtp, skb, xnet);
308 		break;
309 	case UDP_ENCAP_GTP1U:
310 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
311 		ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
312 		break;
313 	default:
314 		ret = -1; /* Shouldn't happen. */
315 	}
316 
317 	switch (ret) {
318 	case 1:
319 		netdev_dbg(gtp->dev, "pass up to the process\n");
320 		return 1;
321 	case 0:
322 		netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
323 		break;
324 	case -1:
325 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
326 		kfree_skb(skb);
327 		return 0;
328 	}
329 
330 	/* Now that the UDP and the GTP header have been removed, set up the
331 	 * new network header. This is required by the upper layer to
332 	 * calculate the transport header.
333 	 */
334 	skb_reset_network_header(skb);
335 
336 	skb->dev = gtp->dev;
337 
338 	stats = this_cpu_ptr(gtp->dev->tstats);
339 	u64_stats_update_begin(&stats->syncp);
340 	stats->rx_packets++;
341 	stats->rx_bytes += skb->len;
342 	u64_stats_update_end(&stats->syncp);
343 
344 	netif_rx(skb);
345 
346 	return 0;
347 }
348 
349 static int gtp_dev_init(struct net_device *dev)
350 {
351 	struct gtp_dev *gtp = netdev_priv(dev);
352 
353 	gtp->dev = dev;
354 
355 	dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
356 	if (!dev->tstats)
357 		return -ENOMEM;
358 
359 	return 0;
360 }
361 
362 static void gtp_dev_uninit(struct net_device *dev)
363 {
364 	struct gtp_dev *gtp = netdev_priv(dev);
365 
366 	gtp_encap_disable(gtp);
367 	free_percpu(dev->tstats);
368 }
369 
370 static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
371 					   const struct sock *sk, __be32 daddr)
372 {
373 	memset(fl4, 0, sizeof(*fl4));
374 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
375 	fl4->daddr		= daddr;
376 	fl4->saddr		= inet_sk(sk)->inet_saddr;
377 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
378 	fl4->flowi4_proto	= sk->sk_protocol;
379 
380 	return ip_route_output_key(net, fl4);
381 }
382 
383 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
384 {
385 	int payload_len = skb->len;
386 	struct gtp0_header *gtp0;
387 
388 	gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
389 
390 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
391 	gtp0->type	= GTP_TPDU;
392 	gtp0->length	= htons(payload_len);
393 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
394 	gtp0->flow	= htons(pctx->u.v0.flow);
395 	gtp0->number	= 0xff;
396 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
397 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
398 }
399 
400 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
401 {
402 	int payload_len = skb->len;
403 	struct gtp1_header *gtp1;
404 
405 	gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
406 
407 	/* Bits    8  7  6  5  4  3  2	1
408 	 *	  +--+--+--+--+--+--+--+--+
409 	 *	  |version |PT| 0| E| S|PN|
410 	 *	  +--+--+--+--+--+--+--+--+
411 	 *	    0  0  1  1	1  0  0  0
412 	 */
413 	gtp1->flags	= 0x30; /* v1, GTP-non-prime. */
414 	gtp1->type	= GTP_TPDU;
415 	gtp1->length	= htons(payload_len);
416 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
417 
418 	/* TODO: Suppport for extension header, sequence number and N-PDU.
419 	 *	 Update the length field if any of them is available.
420 	 */
421 }
422 
423 struct gtp_pktinfo {
424 	struct sock		*sk;
425 	struct iphdr		*iph;
426 	struct flowi4		fl4;
427 	struct rtable		*rt;
428 	struct pdp_ctx		*pctx;
429 	struct net_device	*dev;
430 	__be16			gtph_port;
431 };
432 
433 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
434 {
435 	switch (pktinfo->pctx->gtp_version) {
436 	case GTP_V0:
437 		pktinfo->gtph_port = htons(GTP0_PORT);
438 		gtp0_push_header(skb, pktinfo->pctx);
439 		break;
440 	case GTP_V1:
441 		pktinfo->gtph_port = htons(GTP1U_PORT);
442 		gtp1_push_header(skb, pktinfo->pctx);
443 		break;
444 	}
445 }
446 
447 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
448 					struct sock *sk, struct iphdr *iph,
449 					struct pdp_ctx *pctx, struct rtable *rt,
450 					struct flowi4 *fl4,
451 					struct net_device *dev)
452 {
453 	pktinfo->sk	= sk;
454 	pktinfo->iph	= iph;
455 	pktinfo->pctx	= pctx;
456 	pktinfo->rt	= rt;
457 	pktinfo->fl4	= *fl4;
458 	pktinfo->dev	= dev;
459 }
460 
461 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
462 			     struct gtp_pktinfo *pktinfo)
463 {
464 	struct gtp_dev *gtp = netdev_priv(dev);
465 	struct pdp_ctx *pctx;
466 	struct rtable *rt;
467 	struct flowi4 fl4;
468 	struct iphdr *iph;
469 	struct sock *sk;
470 	__be16 df;
471 	int mtu;
472 
473 	/* Read the IP destination address and resolve the PDP context.
474 	 * Prepend PDP header with TEI/TID from PDP ctx.
475 	 */
476 	iph = ip_hdr(skb);
477 	pctx = ipv4_pdp_find(gtp, iph->daddr);
478 	if (!pctx) {
479 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
480 			   &iph->daddr);
481 		return -ENOENT;
482 	}
483 	netdev_dbg(dev, "found PDP context %p\n", pctx);
484 
485 	switch (pctx->gtp_version) {
486 	case GTP_V0:
487 		if (gtp->sock0)
488 			sk = gtp->sock0->sk;
489 		else
490 			sk = NULL;
491 		break;
492 	case GTP_V1:
493 		if (gtp->sock1u)
494 			sk = gtp->sock1u->sk;
495 		else
496 			sk = NULL;
497 		break;
498 	default:
499 		return -ENOENT;
500 	}
501 
502 	if (!sk) {
503 		netdev_dbg(dev, "no userspace socket is available, skip\n");
504 		return -ENOENT;
505 	}
506 
507 	rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
508 				  pctx->sgsn_addr_ip4.s_addr);
509 	if (IS_ERR(rt)) {
510 		netdev_dbg(dev, "no route to SSGN %pI4\n",
511 			   &pctx->sgsn_addr_ip4.s_addr);
512 		dev->stats.tx_carrier_errors++;
513 		goto err;
514 	}
515 
516 	if (rt->dst.dev == dev) {
517 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
518 			   &pctx->sgsn_addr_ip4.s_addr);
519 		dev->stats.collisions++;
520 		goto err_rt;
521 	}
522 
523 	skb_dst_drop(skb);
524 
525 	/* This is similar to tnl_update_pmtu(). */
526 	df = iph->frag_off;
527 	if (df) {
528 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
529 			sizeof(struct iphdr) - sizeof(struct udphdr);
530 		switch (pctx->gtp_version) {
531 		case GTP_V0:
532 			mtu -= sizeof(struct gtp0_header);
533 			break;
534 		case GTP_V1:
535 			mtu -= sizeof(struct gtp1_header);
536 			break;
537 		}
538 	} else {
539 		mtu = dst_mtu(&rt->dst);
540 	}
541 
542 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
543 
544 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
545 	    mtu < ntohs(iph->tot_len)) {
546 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
547 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
548 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
549 			  htonl(mtu));
550 		goto err_rt;
551 	}
552 
553 	gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
554 	gtp_push_header(skb, pktinfo);
555 
556 	return 0;
557 err_rt:
558 	ip_rt_put(rt);
559 err:
560 	return -EBADMSG;
561 }
562 
563 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
564 {
565 	unsigned int proto = ntohs(skb->protocol);
566 	struct gtp_pktinfo pktinfo;
567 	int err;
568 
569 	/* Ensure there is sufficient headroom. */
570 	if (skb_cow_head(skb, dev->needed_headroom))
571 		goto tx_err;
572 
573 	skb_reset_inner_headers(skb);
574 
575 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
576 	rcu_read_lock();
577 	switch (proto) {
578 	case ETH_P_IP:
579 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
580 		break;
581 	default:
582 		err = -EOPNOTSUPP;
583 		break;
584 	}
585 	rcu_read_unlock();
586 
587 	if (err < 0)
588 		goto tx_err;
589 
590 	switch (proto) {
591 	case ETH_P_IP:
592 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
593 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
594 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
595 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
596 				    pktinfo.iph->tos,
597 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
598 				    0,
599 				    pktinfo.gtph_port, pktinfo.gtph_port,
600 				    true, false);
601 		break;
602 	}
603 
604 	return NETDEV_TX_OK;
605 tx_err:
606 	dev->stats.tx_errors++;
607 	dev_kfree_skb(skb);
608 	return NETDEV_TX_OK;
609 }
610 
611 static const struct net_device_ops gtp_netdev_ops = {
612 	.ndo_init		= gtp_dev_init,
613 	.ndo_uninit		= gtp_dev_uninit,
614 	.ndo_start_xmit		= gtp_dev_xmit,
615 	.ndo_get_stats64	= ip_tunnel_get_stats64,
616 };
617 
618 static void gtp_link_setup(struct net_device *dev)
619 {
620 	dev->netdev_ops		= &gtp_netdev_ops;
621 	dev->destructor		= free_netdev;
622 
623 	dev->hard_header_len = 0;
624 	dev->addr_len = 0;
625 
626 	/* Zero header length. */
627 	dev->type = ARPHRD_NONE;
628 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
629 
630 	dev->priv_flags	|= IFF_NO_QUEUE;
631 	dev->features	|= NETIF_F_LLTX;
632 	netif_keep_dst(dev);
633 
634 	/* Assume largest header, ie. GTPv0. */
635 	dev->needed_headroom	= LL_MAX_HEADER +
636 				  sizeof(struct iphdr) +
637 				  sizeof(struct udphdr) +
638 				  sizeof(struct gtp0_header);
639 }
640 
641 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
642 static void gtp_hashtable_free(struct gtp_dev *gtp);
643 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
644 			    int fd_gtp0, int fd_gtp1);
645 
646 static int gtp_newlink(struct net *src_net, struct net_device *dev,
647 			struct nlattr *tb[], struct nlattr *data[])
648 {
649 	int hashsize, err, fd0, fd1;
650 	struct gtp_dev *gtp;
651 	struct gtp_net *gn;
652 
653 	if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
654 		return -EINVAL;
655 
656 	gtp = netdev_priv(dev);
657 
658 	fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
659 	fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
660 
661 	err = gtp_encap_enable(dev, gtp, fd0, fd1);
662 	if (err < 0)
663 		goto out_err;
664 
665 	if (!data[IFLA_GTP_PDP_HASHSIZE])
666 		hashsize = 1024;
667 	else
668 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
669 
670 	err = gtp_hashtable_new(gtp, hashsize);
671 	if (err < 0)
672 		goto out_encap;
673 
674 	err = register_netdevice(dev);
675 	if (err < 0) {
676 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
677 		goto out_hashtable;
678 	}
679 
680 	gn = net_generic(dev_net(dev), gtp_net_id);
681 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
682 
683 	netdev_dbg(dev, "registered new GTP interface\n");
684 
685 	return 0;
686 
687 out_hashtable:
688 	gtp_hashtable_free(gtp);
689 out_encap:
690 	gtp_encap_disable(gtp);
691 out_err:
692 	return err;
693 }
694 
695 static void gtp_dellink(struct net_device *dev, struct list_head *head)
696 {
697 	struct gtp_dev *gtp = netdev_priv(dev);
698 
699 	gtp_encap_disable(gtp);
700 	gtp_hashtable_free(gtp);
701 	list_del_rcu(&gtp->list);
702 	unregister_netdevice_queue(dev, head);
703 }
704 
705 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
706 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
707 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
708 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
709 };
710 
711 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
712 {
713 	if (!data)
714 		return -EINVAL;
715 
716 	return 0;
717 }
718 
719 static size_t gtp_get_size(const struct net_device *dev)
720 {
721 	return nla_total_size(sizeof(__u32));	/* IFLA_GTP_PDP_HASHSIZE */
722 }
723 
724 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
725 {
726 	struct gtp_dev *gtp = netdev_priv(dev);
727 
728 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
729 		goto nla_put_failure;
730 
731 	return 0;
732 
733 nla_put_failure:
734 	return -EMSGSIZE;
735 }
736 
737 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
738 	.kind		= "gtp",
739 	.maxtype	= IFLA_GTP_MAX,
740 	.policy		= gtp_policy,
741 	.priv_size	= sizeof(struct gtp_dev),
742 	.setup		= gtp_link_setup,
743 	.validate	= gtp_validate,
744 	.newlink	= gtp_newlink,
745 	.dellink	= gtp_dellink,
746 	.get_size	= gtp_get_size,
747 	.fill_info	= gtp_fill_info,
748 };
749 
750 static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[])
751 {
752 	struct net *net;
753 
754 	/* Examine the link attributes and figure out which network namespace
755 	 * we are talking about.
756 	 */
757 	if (tb[GTPA_NET_NS_FD])
758 		net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));
759 	else
760 		net = get_net(src_net);
761 
762 	return net;
763 }
764 
765 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
766 {
767 	int i;
768 
769 	gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
770 	if (gtp->addr_hash == NULL)
771 		return -ENOMEM;
772 
773 	gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
774 	if (gtp->tid_hash == NULL)
775 		goto err1;
776 
777 	gtp->hash_size = hsize;
778 
779 	for (i = 0; i < hsize; i++) {
780 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
781 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
782 	}
783 	return 0;
784 err1:
785 	kfree(gtp->addr_hash);
786 	return -ENOMEM;
787 }
788 
789 static void gtp_hashtable_free(struct gtp_dev *gtp)
790 {
791 	struct pdp_ctx *pctx;
792 	int i;
793 
794 	for (i = 0; i < gtp->hash_size; i++) {
795 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
796 			hlist_del_rcu(&pctx->hlist_tid);
797 			hlist_del_rcu(&pctx->hlist_addr);
798 			kfree_rcu(pctx, rcu_head);
799 		}
800 	}
801 	synchronize_rcu();
802 	kfree(gtp->addr_hash);
803 	kfree(gtp->tid_hash);
804 }
805 
806 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
807 			    int fd_gtp0, int fd_gtp1)
808 {
809 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
810 	struct socket *sock0, *sock1u;
811 	int err;
812 
813 	netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
814 
815 	sock0 = sockfd_lookup(fd_gtp0, &err);
816 	if (sock0 == NULL) {
817 		netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
818 		return -ENOENT;
819 	}
820 
821 	if (sock0->sk->sk_protocol != IPPROTO_UDP) {
822 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
823 		err = -EINVAL;
824 		goto err1;
825 	}
826 
827 	sock1u = sockfd_lookup(fd_gtp1, &err);
828 	if (sock1u == NULL) {
829 		netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
830 		err = -ENOENT;
831 		goto err1;
832 	}
833 
834 	if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
835 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
836 		err = -EINVAL;
837 		goto err2;
838 	}
839 
840 	netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
841 
842 	gtp->sock0 = sock0;
843 	gtp->sock1u = sock1u;
844 
845 	tuncfg.sk_user_data = gtp;
846 	tuncfg.encap_rcv = gtp_encap_recv;
847 	tuncfg.encap_destroy = gtp_encap_destroy;
848 
849 	tuncfg.encap_type = UDP_ENCAP_GTP0;
850 	setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
851 
852 	tuncfg.encap_type = UDP_ENCAP_GTP1U;
853 	setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
854 
855 	err = 0;
856 err2:
857 	sockfd_put(sock1u);
858 err1:
859 	sockfd_put(sock0);
860 	return err;
861 }
862 
863 static struct net_device *gtp_find_dev(struct net *net, int ifindex)
864 {
865 	struct gtp_net *gn = net_generic(net, gtp_net_id);
866 	struct gtp_dev *gtp;
867 
868 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
869 		if (ifindex == gtp->dev->ifindex)
870 			return gtp->dev;
871 	}
872 	return NULL;
873 }
874 
875 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
876 {
877 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
878 	pctx->af = AF_INET;
879 	pctx->sgsn_addr_ip4.s_addr =
880 		nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
881 	pctx->ms_addr_ip4.s_addr =
882 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
883 
884 	switch (pctx->gtp_version) {
885 	case GTP_V0:
886 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
887 		 * label needs to be the same for uplink and downlink packets,
888 		 * so let's annotate this.
889 		 */
890 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
891 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
892 		break;
893 	case GTP_V1:
894 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
895 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
896 		break;
897 	default:
898 		break;
899 	}
900 }
901 
902 static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
903 {
904 	struct gtp_dev *gtp = netdev_priv(dev);
905 	u32 hash_ms, hash_tid = 0;
906 	struct pdp_ctx *pctx;
907 	bool found = false;
908 	__be32 ms_addr;
909 
910 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
911 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
912 
913 	hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
914 		if (pctx->ms_addr_ip4.s_addr == ms_addr) {
915 			found = true;
916 			break;
917 		}
918 	}
919 
920 	if (found) {
921 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
922 			return -EEXIST;
923 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
924 			return -EOPNOTSUPP;
925 
926 		ipv4_pdp_fill(pctx, info);
927 
928 		if (pctx->gtp_version == GTP_V0)
929 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
930 				   pctx->u.v0.tid, pctx);
931 		else if (pctx->gtp_version == GTP_V1)
932 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
933 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
934 
935 		return 0;
936 
937 	}
938 
939 	pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
940 	if (pctx == NULL)
941 		return -ENOMEM;
942 
943 	ipv4_pdp_fill(pctx, info);
944 	atomic_set(&pctx->tx_seq, 0);
945 
946 	switch (pctx->gtp_version) {
947 	case GTP_V0:
948 		/* TS 09.60: "The flow label identifies unambiguously a GTP
949 		 * flow.". We use the tid for this instead, I cannot find a
950 		 * situation in which this doesn't unambiguosly identify the
951 		 * PDP context.
952 		 */
953 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
954 		break;
955 	case GTP_V1:
956 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
957 		break;
958 	}
959 
960 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
961 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
962 
963 	switch (pctx->gtp_version) {
964 	case GTP_V0:
965 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
966 			   pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
967 			   &pctx->ms_addr_ip4, pctx);
968 		break;
969 	case GTP_V1:
970 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
971 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
972 			   &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
973 		break;
974 	}
975 
976 	return 0;
977 }
978 
979 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
980 {
981 	struct net_device *dev;
982 	struct net *net;
983 
984 	if (!info->attrs[GTPA_VERSION] ||
985 	    !info->attrs[GTPA_LINK] ||
986 	    !info->attrs[GTPA_SGSN_ADDRESS] ||
987 	    !info->attrs[GTPA_MS_ADDRESS])
988 		return -EINVAL;
989 
990 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
991 	case GTP_V0:
992 		if (!info->attrs[GTPA_TID] ||
993 		    !info->attrs[GTPA_FLOW])
994 			return -EINVAL;
995 		break;
996 	case GTP_V1:
997 		if (!info->attrs[GTPA_I_TEI] ||
998 		    !info->attrs[GTPA_O_TEI])
999 			return -EINVAL;
1000 		break;
1001 
1002 	default:
1003 		return -EINVAL;
1004 	}
1005 
1006 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1007 	if (IS_ERR(net))
1008 		return PTR_ERR(net);
1009 
1010 	/* Check if there's an existing gtpX device to configure */
1011 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1012 	if (dev == NULL) {
1013 		put_net(net);
1014 		return -ENODEV;
1015 	}
1016 	put_net(net);
1017 
1018 	return ipv4_pdp_add(dev, info);
1019 }
1020 
1021 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1022 {
1023 	struct net_device *dev;
1024 	struct pdp_ctx *pctx;
1025 	struct gtp_dev *gtp;
1026 	struct net *net;
1027 
1028 	if (!info->attrs[GTPA_VERSION] ||
1029 	    !info->attrs[GTPA_LINK])
1030 		return -EINVAL;
1031 
1032 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1033 	if (IS_ERR(net))
1034 		return PTR_ERR(net);
1035 
1036 	/* Check if there's an existing gtpX device to configure */
1037 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1038 	if (dev == NULL) {
1039 		put_net(net);
1040 		return -ENODEV;
1041 	}
1042 	put_net(net);
1043 
1044 	gtp = netdev_priv(dev);
1045 
1046 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1047 	case GTP_V0:
1048 		if (!info->attrs[GTPA_TID])
1049 			return -EINVAL;
1050 		pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
1051 		break;
1052 	case GTP_V1:
1053 		if (!info->attrs[GTPA_I_TEI])
1054 			return -EINVAL;
1055 		pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
1056 		break;
1057 
1058 	default:
1059 		return -EINVAL;
1060 	}
1061 
1062 	if (pctx == NULL)
1063 		return -ENOENT;
1064 
1065 	if (pctx->gtp_version == GTP_V0)
1066 		netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1067 			   pctx->u.v0.tid, pctx);
1068 	else if (pctx->gtp_version == GTP_V1)
1069 		netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1070 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1071 
1072 	hlist_del_rcu(&pctx->hlist_tid);
1073 	hlist_del_rcu(&pctx->hlist_addr);
1074 	kfree_rcu(pctx, rcu_head);
1075 
1076 	return 0;
1077 }
1078 
1079 static struct genl_family gtp_genl_family;
1080 
1081 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1082 			      u32 type, struct pdp_ctx *pctx)
1083 {
1084 	void *genlh;
1085 
1086 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
1087 			    type);
1088 	if (genlh == NULL)
1089 		goto nlmsg_failure;
1090 
1091 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1092 	    nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) ||
1093 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1094 		goto nla_put_failure;
1095 
1096 	switch (pctx->gtp_version) {
1097 	case GTP_V0:
1098 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1099 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1100 			goto nla_put_failure;
1101 		break;
1102 	case GTP_V1:
1103 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1104 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1105 			goto nla_put_failure;
1106 		break;
1107 	}
1108 	genlmsg_end(skb, genlh);
1109 	return 0;
1110 
1111 nlmsg_failure:
1112 nla_put_failure:
1113 	genlmsg_cancel(skb, genlh);
1114 	return -EMSGSIZE;
1115 }
1116 
1117 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1118 {
1119 	struct pdp_ctx *pctx = NULL;
1120 	struct net_device *dev;
1121 	struct sk_buff *skb2;
1122 	struct gtp_dev *gtp;
1123 	u32 gtp_version;
1124 	struct net *net;
1125 	int err;
1126 
1127 	if (!info->attrs[GTPA_VERSION] ||
1128 	    !info->attrs[GTPA_LINK])
1129 		return -EINVAL;
1130 
1131 	gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1132 	switch (gtp_version) {
1133 	case GTP_V0:
1134 	case GTP_V1:
1135 		break;
1136 	default:
1137 		return -EINVAL;
1138 	}
1139 
1140 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1141 	if (IS_ERR(net))
1142 		return PTR_ERR(net);
1143 
1144 	/* Check if there's an existing gtpX device to configure */
1145 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1146 	if (dev == NULL) {
1147 		put_net(net);
1148 		return -ENODEV;
1149 	}
1150 	put_net(net);
1151 
1152 	gtp = netdev_priv(dev);
1153 
1154 	rcu_read_lock();
1155 	if (gtp_version == GTP_V0 &&
1156 	    info->attrs[GTPA_TID]) {
1157 		u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
1158 
1159 		pctx = gtp0_pdp_find(gtp, tid);
1160 	} else if (gtp_version == GTP_V1 &&
1161 		 info->attrs[GTPA_I_TEI]) {
1162 		u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
1163 
1164 		pctx = gtp1_pdp_find(gtp, tid);
1165 	} else if (info->attrs[GTPA_MS_ADDRESS]) {
1166 		__be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1167 
1168 		pctx = ipv4_pdp_find(gtp, ip);
1169 	}
1170 
1171 	if (pctx == NULL) {
1172 		err = -ENOENT;
1173 		goto err_unlock;
1174 	}
1175 
1176 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1177 	if (skb2 == NULL) {
1178 		err = -ENOMEM;
1179 		goto err_unlock;
1180 	}
1181 
1182 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1183 				 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1184 	if (err < 0)
1185 		goto err_unlock_free;
1186 
1187 	rcu_read_unlock();
1188 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1189 
1190 err_unlock_free:
1191 	kfree_skb(skb2);
1192 err_unlock:
1193 	rcu_read_unlock();
1194 	return err;
1195 }
1196 
1197 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1198 				struct netlink_callback *cb)
1199 {
1200 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1201 	struct net *net = sock_net(skb->sk);
1202 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1203 	unsigned long tid = cb->args[1];
1204 	int i, k = cb->args[0], ret;
1205 	struct pdp_ctx *pctx;
1206 
1207 	if (cb->args[4])
1208 		return 0;
1209 
1210 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1211 		if (last_gtp && last_gtp != gtp)
1212 			continue;
1213 		else
1214 			last_gtp = NULL;
1215 
1216 		for (i = k; i < gtp->hash_size; i++) {
1217 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
1218 				if (tid && tid != pctx->u.tid)
1219 					continue;
1220 				else
1221 					tid = 0;
1222 
1223 				ret = gtp_genl_fill_info(skb,
1224 							 NETLINK_CB(cb->skb).portid,
1225 							 cb->nlh->nlmsg_seq,
1226 							 cb->nlh->nlmsg_type, pctx);
1227 				if (ret < 0) {
1228 					cb->args[0] = i;
1229 					cb->args[1] = pctx->u.tid;
1230 					cb->args[2] = (unsigned long)gtp;
1231 					goto out;
1232 				}
1233 			}
1234 		}
1235 	}
1236 	cb->args[4] = 1;
1237 out:
1238 	return skb->len;
1239 }
1240 
1241 static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1242 	[GTPA_LINK]		= { .type = NLA_U32, },
1243 	[GTPA_VERSION]		= { .type = NLA_U32, },
1244 	[GTPA_TID]		= { .type = NLA_U64, },
1245 	[GTPA_SGSN_ADDRESS]	= { .type = NLA_U32, },
1246 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1247 	[GTPA_FLOW]		= { .type = NLA_U16, },
1248 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1249 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1250 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1251 };
1252 
1253 static const struct genl_ops gtp_genl_ops[] = {
1254 	{
1255 		.cmd = GTP_CMD_NEWPDP,
1256 		.doit = gtp_genl_new_pdp,
1257 		.policy = gtp_genl_policy,
1258 		.flags = GENL_ADMIN_PERM,
1259 	},
1260 	{
1261 		.cmd = GTP_CMD_DELPDP,
1262 		.doit = gtp_genl_del_pdp,
1263 		.policy = gtp_genl_policy,
1264 		.flags = GENL_ADMIN_PERM,
1265 	},
1266 	{
1267 		.cmd = GTP_CMD_GETPDP,
1268 		.doit = gtp_genl_get_pdp,
1269 		.dumpit = gtp_genl_dump_pdp,
1270 		.policy = gtp_genl_policy,
1271 		.flags = GENL_ADMIN_PERM,
1272 	},
1273 };
1274 
1275 static struct genl_family gtp_genl_family __ro_after_init = {
1276 	.name		= "gtp",
1277 	.version	= 0,
1278 	.hdrsize	= 0,
1279 	.maxattr	= GTPA_MAX,
1280 	.netnsok	= true,
1281 	.module		= THIS_MODULE,
1282 	.ops		= gtp_genl_ops,
1283 	.n_ops		= ARRAY_SIZE(gtp_genl_ops),
1284 };
1285 
1286 static int __net_init gtp_net_init(struct net *net)
1287 {
1288 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1289 
1290 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1291 	return 0;
1292 }
1293 
1294 static void __net_exit gtp_net_exit(struct net *net)
1295 {
1296 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1297 	struct gtp_dev *gtp;
1298 	LIST_HEAD(list);
1299 
1300 	rtnl_lock();
1301 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1302 		gtp_dellink(gtp->dev, &list);
1303 
1304 	unregister_netdevice_many(&list);
1305 	rtnl_unlock();
1306 }
1307 
1308 static struct pernet_operations gtp_net_ops = {
1309 	.init	= gtp_net_init,
1310 	.exit	= gtp_net_exit,
1311 	.id	= &gtp_net_id,
1312 	.size	= sizeof(struct gtp_net),
1313 };
1314 
1315 static int __init gtp_init(void)
1316 {
1317 	int err;
1318 
1319 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1320 
1321 	err = rtnl_link_register(&gtp_link_ops);
1322 	if (err < 0)
1323 		goto error_out;
1324 
1325 	err = genl_register_family(&gtp_genl_family);
1326 	if (err < 0)
1327 		goto unreg_rtnl_link;
1328 
1329 	err = register_pernet_subsys(&gtp_net_ops);
1330 	if (err < 0)
1331 		goto unreg_genl_family;
1332 
1333 	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1334 		sizeof(struct pdp_ctx));
1335 	return 0;
1336 
1337 unreg_genl_family:
1338 	genl_unregister_family(&gtp_genl_family);
1339 unreg_rtnl_link:
1340 	rtnl_link_unregister(&gtp_link_ops);
1341 error_out:
1342 	pr_err("error loading GTP module loaded\n");
1343 	return err;
1344 }
1345 late_initcall(gtp_init);
1346 
1347 static void __exit gtp_fini(void)
1348 {
1349 	unregister_pernet_subsys(&gtp_net_ops);
1350 	genl_unregister_family(&gtp_genl_family);
1351 	rtnl_link_unregister(&gtp_link_ops);
1352 
1353 	pr_info("GTP module unloaded\n");
1354 }
1355 module_exit(gtp_fini);
1356 
1357 MODULE_LICENSE("GPL");
1358 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1359 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1360 MODULE_ALIAS_RTNL_LINK("gtp");
1361 MODULE_ALIAS_GENL_FAMILY("gtp");
1362