xref: /openbmc/linux/drivers/net/gtp.c (revision ae213c44)
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		peer_addr_ip4;
60 
61 	struct sock		*sk;
62 	struct net_device       *dev;
63 
64 	atomic_t		tx_seq;
65 	struct rcu_head		rcu_head;
66 };
67 
68 /* One instance of the GTP device. */
69 struct gtp_dev {
70 	struct list_head	list;
71 
72 	struct sock		*sk0;
73 	struct sock		*sk1u;
74 
75 	struct net_device	*dev;
76 
77 	unsigned int		role;
78 	unsigned int		hash_size;
79 	struct hlist_head	*tid_hash;
80 	struct hlist_head	*addr_hash;
81 };
82 
83 static unsigned int gtp_net_id __read_mostly;
84 
85 struct gtp_net {
86 	struct list_head gtp_dev_list;
87 };
88 
89 static u32 gtp_h_initval;
90 
91 static void pdp_context_delete(struct pdp_ctx *pctx);
92 
93 static inline u32 gtp0_hashfn(u64 tid)
94 {
95 	u32 *tid32 = (u32 *) &tid;
96 	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
97 }
98 
99 static inline u32 gtp1u_hashfn(u32 tid)
100 {
101 	return jhash_1word(tid, gtp_h_initval);
102 }
103 
104 static inline u32 ipv4_hashfn(__be32 ip)
105 {
106 	return jhash_1word((__force u32)ip, gtp_h_initval);
107 }
108 
109 /* Resolve a PDP context structure based on the 64bit TID. */
110 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
111 {
112 	struct hlist_head *head;
113 	struct pdp_ctx *pdp;
114 
115 	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
116 
117 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
118 		if (pdp->gtp_version == GTP_V0 &&
119 		    pdp->u.v0.tid == tid)
120 			return pdp;
121 	}
122 	return NULL;
123 }
124 
125 /* Resolve a PDP context structure based on the 32bit TEI. */
126 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
127 {
128 	struct hlist_head *head;
129 	struct pdp_ctx *pdp;
130 
131 	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
132 
133 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
134 		if (pdp->gtp_version == GTP_V1 &&
135 		    pdp->u.v1.i_tei == tid)
136 			return pdp;
137 	}
138 	return NULL;
139 }
140 
141 /* Resolve a PDP context based on IPv4 address of MS. */
142 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
143 {
144 	struct hlist_head *head;
145 	struct pdp_ctx *pdp;
146 
147 	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
148 
149 	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
150 		if (pdp->af == AF_INET &&
151 		    pdp->ms_addr_ip4.s_addr == ms_addr)
152 			return pdp;
153 	}
154 
155 	return NULL;
156 }
157 
158 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
159 				  unsigned int hdrlen, unsigned int role)
160 {
161 	struct iphdr *iph;
162 
163 	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
164 		return false;
165 
166 	iph = (struct iphdr *)(skb->data + hdrlen);
167 
168 	if (role == GTP_ROLE_SGSN)
169 		return iph->daddr == pctx->ms_addr_ip4.s_addr;
170 	else
171 		return iph->saddr == pctx->ms_addr_ip4.s_addr;
172 }
173 
174 /* Check if the inner IP address in this packet is assigned to any
175  * existing mobile subscriber.
176  */
177 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
178 			     unsigned int hdrlen, unsigned int role)
179 {
180 	switch (ntohs(skb->protocol)) {
181 	case ETH_P_IP:
182 		return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
183 	}
184 	return false;
185 }
186 
187 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
188 			unsigned int hdrlen, unsigned int role)
189 {
190 	struct pcpu_sw_netstats *stats;
191 
192 	if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
193 		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
194 		return 1;
195 	}
196 
197 	/* Get rid of the GTP + UDP headers. */
198 	if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
199 				 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
200 		return -1;
201 
202 	netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
203 
204 	/* Now that the UDP and the GTP header have been removed, set up the
205 	 * new network header. This is required by the upper layer to
206 	 * calculate the transport header.
207 	 */
208 	skb_reset_network_header(skb);
209 
210 	skb->dev = pctx->dev;
211 
212 	stats = this_cpu_ptr(pctx->dev->tstats);
213 	u64_stats_update_begin(&stats->syncp);
214 	stats->rx_packets++;
215 	stats->rx_bytes += skb->len;
216 	u64_stats_update_end(&stats->syncp);
217 
218 	netif_rx(skb);
219 	return 0;
220 }
221 
222 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
223 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
224 {
225 	unsigned int hdrlen = sizeof(struct udphdr) +
226 			      sizeof(struct gtp0_header);
227 	struct gtp0_header *gtp0;
228 	struct pdp_ctx *pctx;
229 
230 	if (!pskb_may_pull(skb, hdrlen))
231 		return -1;
232 
233 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
234 
235 	if ((gtp0->flags >> 5) != GTP_V0)
236 		return 1;
237 
238 	if (gtp0->type != GTP_TPDU)
239 		return 1;
240 
241 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
242 	if (!pctx) {
243 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
244 		return 1;
245 	}
246 
247 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
248 }
249 
250 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
251 {
252 	unsigned int hdrlen = sizeof(struct udphdr) +
253 			      sizeof(struct gtp1_header);
254 	struct gtp1_header *gtp1;
255 	struct pdp_ctx *pctx;
256 
257 	if (!pskb_may_pull(skb, hdrlen))
258 		return -1;
259 
260 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
261 
262 	if ((gtp1->flags >> 5) != GTP_V1)
263 		return 1;
264 
265 	if (gtp1->type != GTP_TPDU)
266 		return 1;
267 
268 	/* From 29.060: "This field shall be present if and only if any one or
269 	 * more of the S, PN and E flags are set.".
270 	 *
271 	 * If any of the bit is set, then the remaining ones also have to be
272 	 * set.
273 	 */
274 	if (gtp1->flags & GTP1_F_MASK)
275 		hdrlen += 4;
276 
277 	/* Make sure the header is larger enough, including extensions. */
278 	if (!pskb_may_pull(skb, hdrlen))
279 		return -1;
280 
281 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
282 
283 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
284 	if (!pctx) {
285 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
286 		return 1;
287 	}
288 
289 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
290 }
291 
292 static void gtp_encap_destroy(struct sock *sk)
293 {
294 	struct gtp_dev *gtp;
295 
296 	gtp = rcu_dereference_sk_user_data(sk);
297 	if (gtp) {
298 		udp_sk(sk)->encap_type = 0;
299 		rcu_assign_sk_user_data(sk, NULL);
300 		sock_put(sk);
301 	}
302 }
303 
304 static void gtp_encap_disable_sock(struct sock *sk)
305 {
306 	if (!sk)
307 		return;
308 
309 	gtp_encap_destroy(sk);
310 }
311 
312 static void gtp_encap_disable(struct gtp_dev *gtp)
313 {
314 	gtp_encap_disable_sock(gtp->sk0);
315 	gtp_encap_disable_sock(gtp->sk1u);
316 }
317 
318 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
319  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
320  */
321 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
322 {
323 	struct gtp_dev *gtp;
324 	int ret = 0;
325 
326 	gtp = rcu_dereference_sk_user_data(sk);
327 	if (!gtp)
328 		return 1;
329 
330 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
331 
332 	switch (udp_sk(sk)->encap_type) {
333 	case UDP_ENCAP_GTP0:
334 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
335 		ret = gtp0_udp_encap_recv(gtp, skb);
336 		break;
337 	case UDP_ENCAP_GTP1U:
338 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
339 		ret = gtp1u_udp_encap_recv(gtp, skb);
340 		break;
341 	default:
342 		ret = -1; /* Shouldn't happen. */
343 	}
344 
345 	switch (ret) {
346 	case 1:
347 		netdev_dbg(gtp->dev, "pass up to the process\n");
348 		break;
349 	case 0:
350 		break;
351 	case -1:
352 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
353 		kfree_skb(skb);
354 		ret = 0;
355 		break;
356 	}
357 
358 	return ret;
359 }
360 
361 static int gtp_dev_init(struct net_device *dev)
362 {
363 	struct gtp_dev *gtp = netdev_priv(dev);
364 
365 	gtp->dev = dev;
366 
367 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
368 	if (!dev->tstats)
369 		return -ENOMEM;
370 
371 	return 0;
372 }
373 
374 static void gtp_dev_uninit(struct net_device *dev)
375 {
376 	struct gtp_dev *gtp = netdev_priv(dev);
377 
378 	gtp_encap_disable(gtp);
379 	free_percpu(dev->tstats);
380 }
381 
382 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
383 					   const struct sock *sk,
384 					   __be32 daddr)
385 {
386 	memset(fl4, 0, sizeof(*fl4));
387 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
388 	fl4->daddr		= daddr;
389 	fl4->saddr		= inet_sk(sk)->inet_saddr;
390 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
391 	fl4->flowi4_proto	= sk->sk_protocol;
392 
393 	return ip_route_output_key(sock_net(sk), fl4);
394 }
395 
396 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
397 {
398 	int payload_len = skb->len;
399 	struct gtp0_header *gtp0;
400 
401 	gtp0 = skb_push(skb, sizeof(*gtp0));
402 
403 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
404 	gtp0->type	= GTP_TPDU;
405 	gtp0->length	= htons(payload_len);
406 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
407 	gtp0->flow	= htons(pctx->u.v0.flow);
408 	gtp0->number	= 0xff;
409 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
410 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
411 }
412 
413 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
414 {
415 	int payload_len = skb->len;
416 	struct gtp1_header *gtp1;
417 
418 	gtp1 = skb_push(skb, sizeof(*gtp1));
419 
420 	/* Bits    8  7  6  5  4  3  2	1
421 	 *	  +--+--+--+--+--+--+--+--+
422 	 *	  |version |PT| 0| E| S|PN|
423 	 *	  +--+--+--+--+--+--+--+--+
424 	 *	    0  0  1  1	1  0  0  0
425 	 */
426 	gtp1->flags	= 0x30; /* v1, GTP-non-prime. */
427 	gtp1->type	= GTP_TPDU;
428 	gtp1->length	= htons(payload_len);
429 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
430 
431 	/* TODO: Suppport for extension header, sequence number and N-PDU.
432 	 *	 Update the length field if any of them is available.
433 	 */
434 }
435 
436 struct gtp_pktinfo {
437 	struct sock		*sk;
438 	struct iphdr		*iph;
439 	struct flowi4		fl4;
440 	struct rtable		*rt;
441 	struct pdp_ctx		*pctx;
442 	struct net_device	*dev;
443 	__be16			gtph_port;
444 };
445 
446 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
447 {
448 	switch (pktinfo->pctx->gtp_version) {
449 	case GTP_V0:
450 		pktinfo->gtph_port = htons(GTP0_PORT);
451 		gtp0_push_header(skb, pktinfo->pctx);
452 		break;
453 	case GTP_V1:
454 		pktinfo->gtph_port = htons(GTP1U_PORT);
455 		gtp1_push_header(skb, pktinfo->pctx);
456 		break;
457 	}
458 }
459 
460 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
461 					struct sock *sk, struct iphdr *iph,
462 					struct pdp_ctx *pctx, struct rtable *rt,
463 					struct flowi4 *fl4,
464 					struct net_device *dev)
465 {
466 	pktinfo->sk	= sk;
467 	pktinfo->iph	= iph;
468 	pktinfo->pctx	= pctx;
469 	pktinfo->rt	= rt;
470 	pktinfo->fl4	= *fl4;
471 	pktinfo->dev	= dev;
472 }
473 
474 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
475 			     struct gtp_pktinfo *pktinfo)
476 {
477 	struct gtp_dev *gtp = netdev_priv(dev);
478 	struct pdp_ctx *pctx;
479 	struct rtable *rt;
480 	struct flowi4 fl4;
481 	struct iphdr *iph;
482 	__be16 df;
483 	int mtu;
484 
485 	/* Read the IP destination address and resolve the PDP context.
486 	 * Prepend PDP header with TEI/TID from PDP ctx.
487 	 */
488 	iph = ip_hdr(skb);
489 	if (gtp->role == GTP_ROLE_SGSN)
490 		pctx = ipv4_pdp_find(gtp, iph->saddr);
491 	else
492 		pctx = ipv4_pdp_find(gtp, iph->daddr);
493 
494 	if (!pctx) {
495 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
496 			   &iph->daddr);
497 		return -ENOENT;
498 	}
499 	netdev_dbg(dev, "found PDP context %p\n", pctx);
500 
501 	rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
502 	if (IS_ERR(rt)) {
503 		netdev_dbg(dev, "no route to SSGN %pI4\n",
504 			   &pctx->peer_addr_ip4.s_addr);
505 		dev->stats.tx_carrier_errors++;
506 		goto err;
507 	}
508 
509 	if (rt->dst.dev == dev) {
510 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
511 			   &pctx->peer_addr_ip4.s_addr);
512 		dev->stats.collisions++;
513 		goto err_rt;
514 	}
515 
516 	skb_dst_drop(skb);
517 
518 	/* This is similar to tnl_update_pmtu(). */
519 	df = iph->frag_off;
520 	if (df) {
521 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
522 			sizeof(struct iphdr) - sizeof(struct udphdr);
523 		switch (pctx->gtp_version) {
524 		case GTP_V0:
525 			mtu -= sizeof(struct gtp0_header);
526 			break;
527 		case GTP_V1:
528 			mtu -= sizeof(struct gtp1_header);
529 			break;
530 		}
531 	} else {
532 		mtu = dst_mtu(&rt->dst);
533 	}
534 
535 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
536 
537 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
538 	    mtu < ntohs(iph->tot_len)) {
539 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
540 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
541 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
542 			  htonl(mtu));
543 		goto err_rt;
544 	}
545 
546 	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
547 	gtp_push_header(skb, pktinfo);
548 
549 	return 0;
550 err_rt:
551 	ip_rt_put(rt);
552 err:
553 	return -EBADMSG;
554 }
555 
556 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
557 {
558 	unsigned int proto = ntohs(skb->protocol);
559 	struct gtp_pktinfo pktinfo;
560 	int err;
561 
562 	/* Ensure there is sufficient headroom. */
563 	if (skb_cow_head(skb, dev->needed_headroom))
564 		goto tx_err;
565 
566 	skb_reset_inner_headers(skb);
567 
568 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
569 	rcu_read_lock();
570 	switch (proto) {
571 	case ETH_P_IP:
572 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
573 		break;
574 	default:
575 		err = -EOPNOTSUPP;
576 		break;
577 	}
578 	rcu_read_unlock();
579 
580 	if (err < 0)
581 		goto tx_err;
582 
583 	switch (proto) {
584 	case ETH_P_IP:
585 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
586 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
587 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
588 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
589 				    pktinfo.iph->tos,
590 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
591 				    0,
592 				    pktinfo.gtph_port, pktinfo.gtph_port,
593 				    true, false);
594 		break;
595 	}
596 
597 	return NETDEV_TX_OK;
598 tx_err:
599 	dev->stats.tx_errors++;
600 	dev_kfree_skb(skb);
601 	return NETDEV_TX_OK;
602 }
603 
604 static const struct net_device_ops gtp_netdev_ops = {
605 	.ndo_init		= gtp_dev_init,
606 	.ndo_uninit		= gtp_dev_uninit,
607 	.ndo_start_xmit		= gtp_dev_xmit,
608 	.ndo_get_stats64	= ip_tunnel_get_stats64,
609 };
610 
611 static void gtp_link_setup(struct net_device *dev)
612 {
613 	dev->netdev_ops		= &gtp_netdev_ops;
614 	dev->needs_free_netdev	= true;
615 
616 	dev->hard_header_len = 0;
617 	dev->addr_len = 0;
618 
619 	/* Zero header length. */
620 	dev->type = ARPHRD_NONE;
621 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
622 
623 	dev->priv_flags	|= IFF_NO_QUEUE;
624 	dev->features	|= NETIF_F_LLTX;
625 	netif_keep_dst(dev);
626 
627 	/* Assume largest header, ie. GTPv0. */
628 	dev->needed_headroom	= LL_MAX_HEADER +
629 				  sizeof(struct iphdr) +
630 				  sizeof(struct udphdr) +
631 				  sizeof(struct gtp0_header);
632 }
633 
634 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
635 static void gtp_hashtable_free(struct gtp_dev *gtp);
636 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
637 
638 static int gtp_newlink(struct net *src_net, struct net_device *dev,
639 		       struct nlattr *tb[], struct nlattr *data[],
640 		       struct netlink_ext_ack *extack)
641 {
642 	struct gtp_dev *gtp;
643 	struct gtp_net *gn;
644 	int hashsize, err;
645 
646 	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
647 		return -EINVAL;
648 
649 	gtp = netdev_priv(dev);
650 
651 	err = gtp_encap_enable(gtp, data);
652 	if (err < 0)
653 		return err;
654 
655 	if (!data[IFLA_GTP_PDP_HASHSIZE])
656 		hashsize = 1024;
657 	else
658 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
659 
660 	err = gtp_hashtable_new(gtp, hashsize);
661 	if (err < 0)
662 		goto out_encap;
663 
664 	err = register_netdevice(dev);
665 	if (err < 0) {
666 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
667 		goto out_hashtable;
668 	}
669 
670 	gn = net_generic(dev_net(dev), gtp_net_id);
671 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
672 
673 	netdev_dbg(dev, "registered new GTP interface\n");
674 
675 	return 0;
676 
677 out_hashtable:
678 	gtp_hashtable_free(gtp);
679 out_encap:
680 	gtp_encap_disable(gtp);
681 	return err;
682 }
683 
684 static void gtp_dellink(struct net_device *dev, struct list_head *head)
685 {
686 	struct gtp_dev *gtp = netdev_priv(dev);
687 
688 	gtp_encap_disable(gtp);
689 	gtp_hashtable_free(gtp);
690 	list_del_rcu(&gtp->list);
691 	unregister_netdevice_queue(dev, head);
692 }
693 
694 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
695 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
696 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
697 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
698 	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
699 };
700 
701 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
702 			struct netlink_ext_ack *extack)
703 {
704 	if (!data)
705 		return -EINVAL;
706 
707 	return 0;
708 }
709 
710 static size_t gtp_get_size(const struct net_device *dev)
711 {
712 	return nla_total_size(sizeof(__u32));	/* IFLA_GTP_PDP_HASHSIZE */
713 }
714 
715 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
716 {
717 	struct gtp_dev *gtp = netdev_priv(dev);
718 
719 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
720 		goto nla_put_failure;
721 
722 	return 0;
723 
724 nla_put_failure:
725 	return -EMSGSIZE;
726 }
727 
728 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
729 	.kind		= "gtp",
730 	.maxtype	= IFLA_GTP_MAX,
731 	.policy		= gtp_policy,
732 	.priv_size	= sizeof(struct gtp_dev),
733 	.setup		= gtp_link_setup,
734 	.validate	= gtp_validate,
735 	.newlink	= gtp_newlink,
736 	.dellink	= gtp_dellink,
737 	.get_size	= gtp_get_size,
738 	.fill_info	= gtp_fill_info,
739 };
740 
741 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
742 {
743 	int i;
744 
745 	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
746 				       GFP_KERNEL);
747 	if (gtp->addr_hash == NULL)
748 		return -ENOMEM;
749 
750 	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
751 				      GFP_KERNEL);
752 	if (gtp->tid_hash == NULL)
753 		goto err1;
754 
755 	gtp->hash_size = hsize;
756 
757 	for (i = 0; i < hsize; i++) {
758 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
759 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
760 	}
761 	return 0;
762 err1:
763 	kfree(gtp->addr_hash);
764 	return -ENOMEM;
765 }
766 
767 static void gtp_hashtable_free(struct gtp_dev *gtp)
768 {
769 	struct pdp_ctx *pctx;
770 	int i;
771 
772 	for (i = 0; i < gtp->hash_size; i++)
773 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
774 			pdp_context_delete(pctx);
775 
776 	synchronize_rcu();
777 	kfree(gtp->addr_hash);
778 	kfree(gtp->tid_hash);
779 }
780 
781 static struct sock *gtp_encap_enable_socket(int fd, int type,
782 					    struct gtp_dev *gtp)
783 {
784 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
785 	struct socket *sock;
786 	struct sock *sk;
787 	int err;
788 
789 	pr_debug("enable gtp on %d, %d\n", fd, type);
790 
791 	sock = sockfd_lookup(fd, &err);
792 	if (!sock) {
793 		pr_debug("gtp socket fd=%d not found\n", fd);
794 		return NULL;
795 	}
796 
797 	if (sock->sk->sk_protocol != IPPROTO_UDP) {
798 		pr_debug("socket fd=%d not UDP\n", fd);
799 		sk = ERR_PTR(-EINVAL);
800 		goto out_sock;
801 	}
802 
803 	if (rcu_dereference_sk_user_data(sock->sk)) {
804 		sk = ERR_PTR(-EBUSY);
805 		goto out_sock;
806 	}
807 
808 	sk = sock->sk;
809 	sock_hold(sk);
810 
811 	tuncfg.sk_user_data = gtp;
812 	tuncfg.encap_type = type;
813 	tuncfg.encap_rcv = gtp_encap_recv;
814 	tuncfg.encap_destroy = gtp_encap_destroy;
815 
816 	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
817 
818 out_sock:
819 	sockfd_put(sock);
820 	return sk;
821 }
822 
823 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
824 {
825 	struct sock *sk1u = NULL;
826 	struct sock *sk0 = NULL;
827 	unsigned int role = GTP_ROLE_GGSN;
828 
829 	if (data[IFLA_GTP_FD0]) {
830 		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
831 
832 		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
833 		if (IS_ERR(sk0))
834 			return PTR_ERR(sk0);
835 	}
836 
837 	if (data[IFLA_GTP_FD1]) {
838 		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
839 
840 		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
841 		if (IS_ERR(sk1u)) {
842 			if (sk0)
843 				gtp_encap_disable_sock(sk0);
844 			return PTR_ERR(sk1u);
845 		}
846 	}
847 
848 	if (data[IFLA_GTP_ROLE]) {
849 		role = nla_get_u32(data[IFLA_GTP_ROLE]);
850 		if (role > GTP_ROLE_SGSN)
851 			return -EINVAL;
852 	}
853 
854 	gtp->sk0 = sk0;
855 	gtp->sk1u = sk1u;
856 	gtp->role = role;
857 
858 	return 0;
859 }
860 
861 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
862 {
863 	struct gtp_dev *gtp = NULL;
864 	struct net_device *dev;
865 	struct net *net;
866 
867 	/* Examine the link attributes and figure out which network namespace
868 	 * we are talking about.
869 	 */
870 	if (nla[GTPA_NET_NS_FD])
871 		net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
872 	else
873 		net = get_net(src_net);
874 
875 	if (IS_ERR(net))
876 		return NULL;
877 
878 	/* Check if there's an existing gtpX device to configure */
879 	dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
880 	if (dev && dev->netdev_ops == &gtp_netdev_ops)
881 		gtp = netdev_priv(dev);
882 
883 	put_net(net);
884 	return gtp;
885 }
886 
887 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
888 {
889 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
890 	pctx->af = AF_INET;
891 	pctx->peer_addr_ip4.s_addr =
892 		nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
893 	pctx->ms_addr_ip4.s_addr =
894 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
895 
896 	switch (pctx->gtp_version) {
897 	case GTP_V0:
898 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
899 		 * label needs to be the same for uplink and downlink packets,
900 		 * so let's annotate this.
901 		 */
902 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
903 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
904 		break;
905 	case GTP_V1:
906 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
907 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
908 		break;
909 	default:
910 		break;
911 	}
912 }
913 
914 static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
915 			struct genl_info *info)
916 {
917 	struct net_device *dev = gtp->dev;
918 	u32 hash_ms, hash_tid = 0;
919 	struct pdp_ctx *pctx;
920 	bool found = false;
921 	__be32 ms_addr;
922 
923 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
924 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
925 
926 	hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
927 		if (pctx->ms_addr_ip4.s_addr == ms_addr) {
928 			found = true;
929 			break;
930 		}
931 	}
932 
933 	if (found) {
934 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
935 			return -EEXIST;
936 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
937 			return -EOPNOTSUPP;
938 
939 		ipv4_pdp_fill(pctx, info);
940 
941 		if (pctx->gtp_version == GTP_V0)
942 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
943 				   pctx->u.v0.tid, pctx);
944 		else if (pctx->gtp_version == GTP_V1)
945 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
946 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
947 
948 		return 0;
949 
950 	}
951 
952 	pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
953 	if (pctx == NULL)
954 		return -ENOMEM;
955 
956 	sock_hold(sk);
957 	pctx->sk = sk;
958 	pctx->dev = gtp->dev;
959 	ipv4_pdp_fill(pctx, info);
960 	atomic_set(&pctx->tx_seq, 0);
961 
962 	switch (pctx->gtp_version) {
963 	case GTP_V0:
964 		/* TS 09.60: "The flow label identifies unambiguously a GTP
965 		 * flow.". We use the tid for this instead, I cannot find a
966 		 * situation in which this doesn't unambiguosly identify the
967 		 * PDP context.
968 		 */
969 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
970 		break;
971 	case GTP_V1:
972 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
973 		break;
974 	}
975 
976 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
977 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
978 
979 	switch (pctx->gtp_version) {
980 	case GTP_V0:
981 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
982 			   pctx->u.v0.tid, &pctx->peer_addr_ip4,
983 			   &pctx->ms_addr_ip4, pctx);
984 		break;
985 	case GTP_V1:
986 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
987 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
988 			   &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
989 		break;
990 	}
991 
992 	return 0;
993 }
994 
995 static void pdp_context_free(struct rcu_head *head)
996 {
997 	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
998 
999 	sock_put(pctx->sk);
1000 	kfree(pctx);
1001 }
1002 
1003 static void pdp_context_delete(struct pdp_ctx *pctx)
1004 {
1005 	hlist_del_rcu(&pctx->hlist_tid);
1006 	hlist_del_rcu(&pctx->hlist_addr);
1007 	call_rcu(&pctx->rcu_head, pdp_context_free);
1008 }
1009 
1010 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1011 {
1012 	unsigned int version;
1013 	struct gtp_dev *gtp;
1014 	struct sock *sk;
1015 	int err;
1016 
1017 	if (!info->attrs[GTPA_VERSION] ||
1018 	    !info->attrs[GTPA_LINK] ||
1019 	    !info->attrs[GTPA_PEER_ADDRESS] ||
1020 	    !info->attrs[GTPA_MS_ADDRESS])
1021 		return -EINVAL;
1022 
1023 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1024 
1025 	switch (version) {
1026 	case GTP_V0:
1027 		if (!info->attrs[GTPA_TID] ||
1028 		    !info->attrs[GTPA_FLOW])
1029 			return -EINVAL;
1030 		break;
1031 	case GTP_V1:
1032 		if (!info->attrs[GTPA_I_TEI] ||
1033 		    !info->attrs[GTPA_O_TEI])
1034 			return -EINVAL;
1035 		break;
1036 
1037 	default:
1038 		return -EINVAL;
1039 	}
1040 
1041 	rcu_read_lock();
1042 
1043 	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1044 	if (!gtp) {
1045 		err = -ENODEV;
1046 		goto out_unlock;
1047 	}
1048 
1049 	if (version == GTP_V0)
1050 		sk = gtp->sk0;
1051 	else if (version == GTP_V1)
1052 		sk = gtp->sk1u;
1053 	else
1054 		sk = NULL;
1055 
1056 	if (!sk) {
1057 		err = -ENODEV;
1058 		goto out_unlock;
1059 	}
1060 
1061 	err = ipv4_pdp_add(gtp, sk, info);
1062 
1063 out_unlock:
1064 	rcu_read_unlock();
1065 	return err;
1066 }
1067 
1068 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1069 					    struct nlattr *nla[])
1070 {
1071 	struct gtp_dev *gtp;
1072 
1073 	gtp = gtp_find_dev(net, nla);
1074 	if (!gtp)
1075 		return ERR_PTR(-ENODEV);
1076 
1077 	if (nla[GTPA_MS_ADDRESS]) {
1078 		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1079 
1080 		return ipv4_pdp_find(gtp, ip);
1081 	} else if (nla[GTPA_VERSION]) {
1082 		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1083 
1084 		if (gtp_version == GTP_V0 && nla[GTPA_TID])
1085 			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1086 		else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1087 			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1088 	}
1089 
1090 	return ERR_PTR(-EINVAL);
1091 }
1092 
1093 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1094 {
1095 	struct pdp_ctx *pctx;
1096 
1097 	if (nla[GTPA_LINK])
1098 		pctx = gtp_find_pdp_by_link(net, nla);
1099 	else
1100 		pctx = ERR_PTR(-EINVAL);
1101 
1102 	if (!pctx)
1103 		pctx = ERR_PTR(-ENOENT);
1104 
1105 	return pctx;
1106 }
1107 
1108 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1109 {
1110 	struct pdp_ctx *pctx;
1111 	int err = 0;
1112 
1113 	if (!info->attrs[GTPA_VERSION])
1114 		return -EINVAL;
1115 
1116 	rcu_read_lock();
1117 
1118 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1119 	if (IS_ERR(pctx)) {
1120 		err = PTR_ERR(pctx);
1121 		goto out_unlock;
1122 	}
1123 
1124 	if (pctx->gtp_version == GTP_V0)
1125 		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1126 			   pctx->u.v0.tid, pctx);
1127 	else if (pctx->gtp_version == GTP_V1)
1128 		netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1129 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1130 
1131 	pdp_context_delete(pctx);
1132 
1133 out_unlock:
1134 	rcu_read_unlock();
1135 	return err;
1136 }
1137 
1138 static struct genl_family gtp_genl_family;
1139 
1140 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1141 			      u32 type, struct pdp_ctx *pctx)
1142 {
1143 	void *genlh;
1144 
1145 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
1146 			    type);
1147 	if (genlh == NULL)
1148 		goto nlmsg_failure;
1149 
1150 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1151 	    nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1152 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1153 		goto nla_put_failure;
1154 
1155 	switch (pctx->gtp_version) {
1156 	case GTP_V0:
1157 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1158 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1159 			goto nla_put_failure;
1160 		break;
1161 	case GTP_V1:
1162 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1163 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1164 			goto nla_put_failure;
1165 		break;
1166 	}
1167 	genlmsg_end(skb, genlh);
1168 	return 0;
1169 
1170 nlmsg_failure:
1171 nla_put_failure:
1172 	genlmsg_cancel(skb, genlh);
1173 	return -EMSGSIZE;
1174 }
1175 
1176 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1177 {
1178 	struct pdp_ctx *pctx = NULL;
1179 	struct sk_buff *skb2;
1180 	int err;
1181 
1182 	if (!info->attrs[GTPA_VERSION])
1183 		return -EINVAL;
1184 
1185 	rcu_read_lock();
1186 
1187 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1188 	if (IS_ERR(pctx)) {
1189 		err = PTR_ERR(pctx);
1190 		goto err_unlock;
1191 	}
1192 
1193 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1194 	if (skb2 == NULL) {
1195 		err = -ENOMEM;
1196 		goto err_unlock;
1197 	}
1198 
1199 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1200 				 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1201 	if (err < 0)
1202 		goto err_unlock_free;
1203 
1204 	rcu_read_unlock();
1205 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1206 
1207 err_unlock_free:
1208 	kfree_skb(skb2);
1209 err_unlock:
1210 	rcu_read_unlock();
1211 	return err;
1212 }
1213 
1214 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1215 				struct netlink_callback *cb)
1216 {
1217 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1218 	struct net *net = sock_net(skb->sk);
1219 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1220 	unsigned long tid = cb->args[1];
1221 	int i, k = cb->args[0], ret;
1222 	struct pdp_ctx *pctx;
1223 
1224 	if (cb->args[4])
1225 		return 0;
1226 
1227 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1228 		if (last_gtp && last_gtp != gtp)
1229 			continue;
1230 		else
1231 			last_gtp = NULL;
1232 
1233 		for (i = k; i < gtp->hash_size; i++) {
1234 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
1235 				if (tid && tid != pctx->u.tid)
1236 					continue;
1237 				else
1238 					tid = 0;
1239 
1240 				ret = gtp_genl_fill_info(skb,
1241 							 NETLINK_CB(cb->skb).portid,
1242 							 cb->nlh->nlmsg_seq,
1243 							 cb->nlh->nlmsg_type, pctx);
1244 				if (ret < 0) {
1245 					cb->args[0] = i;
1246 					cb->args[1] = pctx->u.tid;
1247 					cb->args[2] = (unsigned long)gtp;
1248 					goto out;
1249 				}
1250 			}
1251 		}
1252 	}
1253 	cb->args[4] = 1;
1254 out:
1255 	return skb->len;
1256 }
1257 
1258 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1259 	[GTPA_LINK]		= { .type = NLA_U32, },
1260 	[GTPA_VERSION]		= { .type = NLA_U32, },
1261 	[GTPA_TID]		= { .type = NLA_U64, },
1262 	[GTPA_PEER_ADDRESS]	= { .type = NLA_U32, },
1263 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1264 	[GTPA_FLOW]		= { .type = NLA_U16, },
1265 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1266 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1267 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1268 };
1269 
1270 static const struct genl_ops gtp_genl_ops[] = {
1271 	{
1272 		.cmd = GTP_CMD_NEWPDP,
1273 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1274 		.doit = gtp_genl_new_pdp,
1275 		.flags = GENL_ADMIN_PERM,
1276 	},
1277 	{
1278 		.cmd = GTP_CMD_DELPDP,
1279 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1280 		.doit = gtp_genl_del_pdp,
1281 		.flags = GENL_ADMIN_PERM,
1282 	},
1283 	{
1284 		.cmd = GTP_CMD_GETPDP,
1285 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1286 		.doit = gtp_genl_get_pdp,
1287 		.dumpit = gtp_genl_dump_pdp,
1288 		.flags = GENL_ADMIN_PERM,
1289 	},
1290 };
1291 
1292 static struct genl_family gtp_genl_family __ro_after_init = {
1293 	.name		= "gtp",
1294 	.version	= 0,
1295 	.hdrsize	= 0,
1296 	.maxattr	= GTPA_MAX,
1297 	.policy = gtp_genl_policy,
1298 	.netnsok	= true,
1299 	.module		= THIS_MODULE,
1300 	.ops		= gtp_genl_ops,
1301 	.n_ops		= ARRAY_SIZE(gtp_genl_ops),
1302 };
1303 
1304 static int __net_init gtp_net_init(struct net *net)
1305 {
1306 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1307 
1308 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1309 	return 0;
1310 }
1311 
1312 static void __net_exit gtp_net_exit(struct net *net)
1313 {
1314 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1315 	struct gtp_dev *gtp;
1316 	LIST_HEAD(list);
1317 
1318 	rtnl_lock();
1319 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1320 		gtp_dellink(gtp->dev, &list);
1321 
1322 	unregister_netdevice_many(&list);
1323 	rtnl_unlock();
1324 }
1325 
1326 static struct pernet_operations gtp_net_ops = {
1327 	.init	= gtp_net_init,
1328 	.exit	= gtp_net_exit,
1329 	.id	= &gtp_net_id,
1330 	.size	= sizeof(struct gtp_net),
1331 };
1332 
1333 static int __init gtp_init(void)
1334 {
1335 	int err;
1336 
1337 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1338 
1339 	err = rtnl_link_register(&gtp_link_ops);
1340 	if (err < 0)
1341 		goto error_out;
1342 
1343 	err = genl_register_family(&gtp_genl_family);
1344 	if (err < 0)
1345 		goto unreg_rtnl_link;
1346 
1347 	err = register_pernet_subsys(&gtp_net_ops);
1348 	if (err < 0)
1349 		goto unreg_genl_family;
1350 
1351 	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1352 		sizeof(struct pdp_ctx));
1353 	return 0;
1354 
1355 unreg_genl_family:
1356 	genl_unregister_family(&gtp_genl_family);
1357 unreg_rtnl_link:
1358 	rtnl_link_unregister(&gtp_link_ops);
1359 error_out:
1360 	pr_err("error loading GTP module loaded\n");
1361 	return err;
1362 }
1363 late_initcall(gtp_init);
1364 
1365 static void __exit gtp_fini(void)
1366 {
1367 	unregister_pernet_subsys(&gtp_net_ops);
1368 	genl_unregister_family(&gtp_genl_family);
1369 	rtnl_link_unregister(&gtp_link_ops);
1370 
1371 	pr_info("GTP module unloaded\n");
1372 }
1373 module_exit(gtp_fini);
1374 
1375 MODULE_LICENSE("GPL");
1376 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1377 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1378 MODULE_ALIAS_RTNL_LINK("gtp");
1379 MODULE_ALIAS_GENL_FAMILY("gtp");
1380