xref: /linux/drivers/net/gtp.c (revision b6ebbac51bedf9e98e837688bc838f400196da5e)
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		*net;
73 	struct net_device	*dev;
74 
75 	unsigned int		hash_size;
76 	struct hlist_head	*tid_hash;
77 	struct hlist_head	*addr_hash;
78 };
79 
80 static int gtp_net_id __read_mostly;
81 
82 struct gtp_net {
83 	struct list_head gtp_dev_list;
84 };
85 
86 static u32 gtp_h_initval;
87 
88 static inline u32 gtp0_hashfn(u64 tid)
89 {
90 	u32 *tid32 = (u32 *) &tid;
91 	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
92 }
93 
94 static inline u32 gtp1u_hashfn(u32 tid)
95 {
96 	return jhash_1word(tid, gtp_h_initval);
97 }
98 
99 static inline u32 ipv4_hashfn(__be32 ip)
100 {
101 	return jhash_1word((__force u32)ip, gtp_h_initval);
102 }
103 
104 /* Resolve a PDP context structure based on the 64bit TID. */
105 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
106 {
107 	struct hlist_head *head;
108 	struct pdp_ctx *pdp;
109 
110 	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
111 
112 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
113 		if (pdp->gtp_version == GTP_V0 &&
114 		    pdp->u.v0.tid == tid)
115 			return pdp;
116 	}
117 	return NULL;
118 }
119 
120 /* Resolve a PDP context structure based on the 32bit TEI. */
121 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
122 {
123 	struct hlist_head *head;
124 	struct pdp_ctx *pdp;
125 
126 	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
127 
128 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
129 		if (pdp->gtp_version == GTP_V1 &&
130 		    pdp->u.v1.i_tei == tid)
131 			return pdp;
132 	}
133 	return NULL;
134 }
135 
136 /* Resolve a PDP context based on IPv4 address of MS. */
137 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
138 {
139 	struct hlist_head *head;
140 	struct pdp_ctx *pdp;
141 
142 	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
143 
144 	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
145 		if (pdp->af == AF_INET &&
146 		    pdp->ms_addr_ip4.s_addr == ms_addr)
147 			return pdp;
148 	}
149 
150 	return NULL;
151 }
152 
153 static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
154 				  unsigned int hdrlen)
155 {
156 	struct iphdr *iph;
157 
158 	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
159 		return false;
160 
161 	iph = (struct iphdr *)(skb->data + hdrlen + sizeof(struct iphdr));
162 
163 	return iph->saddr != pctx->ms_addr_ip4.s_addr;
164 }
165 
166 /* Check if the inner IP source address in this packet is assigned to any
167  * existing mobile subscriber.
168  */
169 static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
170 			     unsigned int hdrlen)
171 {
172 	switch (ntohs(skb->protocol)) {
173 	case ETH_P_IP:
174 		return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
175 	}
176 	return false;
177 }
178 
179 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
180 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
181 			       bool xnet)
182 {
183 	unsigned int hdrlen = sizeof(struct udphdr) +
184 			      sizeof(struct gtp0_header);
185 	struct gtp0_header *gtp0;
186 	struct pdp_ctx *pctx;
187 	int ret = 0;
188 
189 	if (!pskb_may_pull(skb, hdrlen))
190 		return -1;
191 
192 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
193 
194 	if ((gtp0->flags >> 5) != GTP_V0)
195 		return 1;
196 
197 	if (gtp0->type != GTP_TPDU)
198 		return 1;
199 
200 	rcu_read_lock();
201 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
202 	if (!pctx) {
203 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
204 		ret = -1;
205 		goto out_rcu;
206 	}
207 
208 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
209 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
210 		ret = -1;
211 		goto out_rcu;
212 	}
213 	rcu_read_unlock();
214 
215 	/* Get rid of the GTP + UDP headers. */
216 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
217 out_rcu:
218 	rcu_read_unlock();
219 	return ret;
220 }
221 
222 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
223 				bool xnet)
224 {
225 	unsigned int hdrlen = sizeof(struct udphdr) +
226 			      sizeof(struct gtp1_header);
227 	struct gtp1_header *gtp1;
228 	struct pdp_ctx *pctx;
229 	int ret = 0;
230 
231 	if (!pskb_may_pull(skb, hdrlen))
232 		return -1;
233 
234 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
235 
236 	if ((gtp1->flags >> 5) != GTP_V1)
237 		return 1;
238 
239 	if (gtp1->type != GTP_TPDU)
240 		return 1;
241 
242 	/* From 29.060: "This field shall be present if and only if any one or
243 	 * more of the S, PN and E flags are set.".
244 	 *
245 	 * If any of the bit is set, then the remaining ones also have to be
246 	 * set.
247 	 */
248 	if (gtp1->flags & GTP1_F_MASK)
249 		hdrlen += 4;
250 
251 	/* Make sure the header is larger enough, including extensions. */
252 	if (!pskb_may_pull(skb, hdrlen))
253 		return -1;
254 
255 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
256 
257 	rcu_read_lock();
258 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
259 	if (!pctx) {
260 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
261 		ret = -1;
262 		goto out_rcu;
263 	}
264 
265 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
266 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
267 		ret = -1;
268 		goto out_rcu;
269 	}
270 	rcu_read_unlock();
271 
272 	/* Get rid of the GTP + UDP headers. */
273 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
274 out_rcu:
275 	rcu_read_unlock();
276 	return ret;
277 }
278 
279 static void gtp_encap_disable(struct gtp_dev *gtp)
280 {
281 	if (gtp->sock0 && gtp->sock0->sk) {
282 		udp_sk(gtp->sock0->sk)->encap_type = 0;
283 		rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
284 	}
285 	if (gtp->sock1u && gtp->sock1u->sk) {
286 		udp_sk(gtp->sock1u->sk)->encap_type = 0;
287 		rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
288 	}
289 
290 	gtp->sock0 = NULL;
291 	gtp->sock1u = NULL;
292 }
293 
294 static void gtp_encap_destroy(struct sock *sk)
295 {
296 	struct gtp_dev *gtp;
297 
298 	gtp = rcu_dereference_sk_user_data(sk);
299 	if (gtp)
300 		gtp_encap_disable(gtp);
301 }
302 
303 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
304  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
305  */
306 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
307 {
308 	struct pcpu_sw_netstats *stats;
309 	struct gtp_dev *gtp;
310 	bool xnet;
311 	int ret;
312 
313 	gtp = rcu_dereference_sk_user_data(sk);
314 	if (!gtp)
315 		return 1;
316 
317 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
318 
319 	xnet = !net_eq(gtp->net, dev_net(gtp->dev));
320 
321 	switch (udp_sk(sk)->encap_type) {
322 	case UDP_ENCAP_GTP0:
323 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
324 		ret = gtp0_udp_encap_recv(gtp, skb, xnet);
325 		break;
326 	case UDP_ENCAP_GTP1U:
327 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
328 		ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
329 		break;
330 	default:
331 		ret = -1; /* Shouldn't happen. */
332 	}
333 
334 	switch (ret) {
335 	case 1:
336 		netdev_dbg(gtp->dev, "pass up to the process\n");
337 		return 1;
338 	case 0:
339 		netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
340 		break;
341 	case -1:
342 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
343 		kfree_skb(skb);
344 		return 0;
345 	}
346 
347 	/* Now that the UDP and the GTP header have been removed, set up the
348 	 * new network header. This is required by the upper layer to
349 	 * calculate the transport header.
350 	 */
351 	skb_reset_network_header(skb);
352 
353 	skb->dev = gtp->dev;
354 
355 	stats = this_cpu_ptr(gtp->dev->tstats);
356 	u64_stats_update_begin(&stats->syncp);
357 	stats->rx_packets++;
358 	stats->rx_bytes += skb->len;
359 	u64_stats_update_end(&stats->syncp);
360 
361 	netif_rx(skb);
362 
363 	return 0;
364 }
365 
366 static int gtp_dev_init(struct net_device *dev)
367 {
368 	struct gtp_dev *gtp = netdev_priv(dev);
369 
370 	gtp->dev = dev;
371 
372 	dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
373 	if (!dev->tstats)
374 		return -ENOMEM;
375 
376 	return 0;
377 }
378 
379 static void gtp_dev_uninit(struct net_device *dev)
380 {
381 	struct gtp_dev *gtp = netdev_priv(dev);
382 
383 	gtp_encap_disable(gtp);
384 	free_percpu(dev->tstats);
385 }
386 
387 static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
388 					   const struct sock *sk, __be32 daddr)
389 {
390 	memset(fl4, 0, sizeof(*fl4));
391 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
392 	fl4->daddr		= daddr;
393 	fl4->saddr		= inet_sk(sk)->inet_saddr;
394 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
395 	fl4->flowi4_proto	= sk->sk_protocol;
396 
397 	return ip_route_output_key(net, fl4);
398 }
399 
400 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
401 {
402 	int payload_len = skb->len;
403 	struct gtp0_header *gtp0;
404 
405 	gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
406 
407 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
408 	gtp0->type	= GTP_TPDU;
409 	gtp0->length	= htons(payload_len);
410 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
411 	gtp0->flow	= htons(pctx->u.v0.flow);
412 	gtp0->number	= 0xff;
413 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
414 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
415 }
416 
417 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
418 {
419 	int payload_len = skb->len;
420 	struct gtp1_header *gtp1;
421 
422 	gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
423 
424 	/* Bits    8  7  6  5  4  3  2	1
425 	 *	  +--+--+--+--+--+--+--+--+
426 	 *	  |version |PT| 1| E| S|PN|
427 	 *	  +--+--+--+--+--+--+--+--+
428 	 *	    0  0  1  1	1  0  0  0
429 	 */
430 	gtp1->flags	= 0x38; /* v1, GTP-non-prime. */
431 	gtp1->type	= GTP_TPDU;
432 	gtp1->length	= htons(payload_len);
433 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
434 
435 	/* TODO: Suppport for extension header, sequence number and N-PDU.
436 	 *	 Update the length field if any of them is available.
437 	 */
438 }
439 
440 struct gtp_pktinfo {
441 	struct sock		*sk;
442 	struct iphdr		*iph;
443 	struct flowi4		fl4;
444 	struct rtable		*rt;
445 	struct pdp_ctx		*pctx;
446 	struct net_device	*dev;
447 	__be16			gtph_port;
448 };
449 
450 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
451 {
452 	switch (pktinfo->pctx->gtp_version) {
453 	case GTP_V0:
454 		pktinfo->gtph_port = htons(GTP0_PORT);
455 		gtp0_push_header(skb, pktinfo->pctx);
456 		break;
457 	case GTP_V1:
458 		pktinfo->gtph_port = htons(GTP1U_PORT);
459 		gtp1_push_header(skb, pktinfo->pctx);
460 		break;
461 	}
462 }
463 
464 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
465 					struct sock *sk, struct iphdr *iph,
466 					struct pdp_ctx *pctx, struct rtable *rt,
467 					struct flowi4 *fl4,
468 					struct net_device *dev)
469 {
470 	pktinfo->sk	= sk;
471 	pktinfo->iph	= iph;
472 	pktinfo->pctx	= pctx;
473 	pktinfo->rt	= rt;
474 	pktinfo->fl4	= *fl4;
475 	pktinfo->dev	= dev;
476 }
477 
478 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
479 			     struct gtp_pktinfo *pktinfo)
480 {
481 	struct gtp_dev *gtp = netdev_priv(dev);
482 	struct pdp_ctx *pctx;
483 	struct rtable *rt;
484 	struct flowi4 fl4;
485 	struct iphdr *iph;
486 	struct sock *sk;
487 	__be16 df;
488 	int mtu;
489 
490 	/* Read the IP destination address and resolve the PDP context.
491 	 * Prepend PDP header with TEI/TID from PDP ctx.
492 	 */
493 	iph = ip_hdr(skb);
494 	pctx = ipv4_pdp_find(gtp, iph->daddr);
495 	if (!pctx) {
496 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
497 			   &iph->daddr);
498 		return -ENOENT;
499 	}
500 	netdev_dbg(dev, "found PDP context %p\n", pctx);
501 
502 	switch (pctx->gtp_version) {
503 	case GTP_V0:
504 		if (gtp->sock0)
505 			sk = gtp->sock0->sk;
506 		else
507 			sk = NULL;
508 		break;
509 	case GTP_V1:
510 		if (gtp->sock1u)
511 			sk = gtp->sock1u->sk;
512 		else
513 			sk = NULL;
514 		break;
515 	default:
516 		return -ENOENT;
517 	}
518 
519 	if (!sk) {
520 		netdev_dbg(dev, "no userspace socket is available, skip\n");
521 		return -ENOENT;
522 	}
523 
524 	rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
525 				  pctx->sgsn_addr_ip4.s_addr);
526 	if (IS_ERR(rt)) {
527 		netdev_dbg(dev, "no route to SSGN %pI4\n",
528 			   &pctx->sgsn_addr_ip4.s_addr);
529 		dev->stats.tx_carrier_errors++;
530 		goto err;
531 	}
532 
533 	if (rt->dst.dev == dev) {
534 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
535 			   &pctx->sgsn_addr_ip4.s_addr);
536 		dev->stats.collisions++;
537 		goto err_rt;
538 	}
539 
540 	skb_dst_drop(skb);
541 
542 	/* This is similar to tnl_update_pmtu(). */
543 	df = iph->frag_off;
544 	if (df) {
545 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
546 			sizeof(struct iphdr) - sizeof(struct udphdr);
547 		switch (pctx->gtp_version) {
548 		case GTP_V0:
549 			mtu -= sizeof(struct gtp0_header);
550 			break;
551 		case GTP_V1:
552 			mtu -= sizeof(struct gtp1_header);
553 			break;
554 		}
555 	} else {
556 		mtu = dst_mtu(&rt->dst);
557 	}
558 
559 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
560 
561 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
562 	    mtu < ntohs(iph->tot_len)) {
563 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
564 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
565 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
566 			  htonl(mtu));
567 		goto err_rt;
568 	}
569 
570 	gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
571 	gtp_push_header(skb, pktinfo);
572 
573 	return 0;
574 err_rt:
575 	ip_rt_put(rt);
576 err:
577 	return -EBADMSG;
578 }
579 
580 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
581 {
582 	unsigned int proto = ntohs(skb->protocol);
583 	struct gtp_pktinfo pktinfo;
584 	int err;
585 
586 	/* Ensure there is sufficient headroom. */
587 	if (skb_cow_head(skb, dev->needed_headroom))
588 		goto tx_err;
589 
590 	skb_reset_inner_headers(skb);
591 
592 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
593 	rcu_read_lock();
594 	switch (proto) {
595 	case ETH_P_IP:
596 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
597 		break;
598 	default:
599 		err = -EOPNOTSUPP;
600 		break;
601 	}
602 	rcu_read_unlock();
603 
604 	if (err < 0)
605 		goto tx_err;
606 
607 	switch (proto) {
608 	case ETH_P_IP:
609 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
610 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
611 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
612 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
613 				    pktinfo.iph->tos,
614 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
615 				    htons(IP_DF),
616 				    pktinfo.gtph_port, pktinfo.gtph_port,
617 				    true, false);
618 		break;
619 	}
620 
621 	return NETDEV_TX_OK;
622 tx_err:
623 	dev->stats.tx_errors++;
624 	dev_kfree_skb(skb);
625 	return NETDEV_TX_OK;
626 }
627 
628 static const struct net_device_ops gtp_netdev_ops = {
629 	.ndo_init		= gtp_dev_init,
630 	.ndo_uninit		= gtp_dev_uninit,
631 	.ndo_start_xmit		= gtp_dev_xmit,
632 	.ndo_get_stats64	= ip_tunnel_get_stats64,
633 };
634 
635 static void gtp_link_setup(struct net_device *dev)
636 {
637 	dev->netdev_ops		= &gtp_netdev_ops;
638 	dev->destructor		= free_netdev;
639 
640 	dev->hard_header_len = 0;
641 	dev->addr_len = 0;
642 
643 	/* Zero header length. */
644 	dev->type = ARPHRD_NONE;
645 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
646 
647 	dev->priv_flags	|= IFF_NO_QUEUE;
648 	dev->features	|= NETIF_F_LLTX;
649 	netif_keep_dst(dev);
650 
651 	/* Assume largest header, ie. GTPv0. */
652 	dev->needed_headroom	= LL_MAX_HEADER +
653 				  sizeof(struct iphdr) +
654 				  sizeof(struct udphdr) +
655 				  sizeof(struct gtp0_header);
656 }
657 
658 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
659 static void gtp_hashtable_free(struct gtp_dev *gtp);
660 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
661 			    int fd_gtp0, int fd_gtp1, struct net *src_net);
662 
663 static int gtp_newlink(struct net *src_net, struct net_device *dev,
664 			struct nlattr *tb[], struct nlattr *data[])
665 {
666 	int hashsize, err, fd0, fd1;
667 	struct gtp_dev *gtp;
668 	struct gtp_net *gn;
669 
670 	if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
671 		return -EINVAL;
672 
673 	gtp = netdev_priv(dev);
674 
675 	fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
676 	fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
677 
678 	err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net);
679 	if (err < 0)
680 		goto out_err;
681 
682 	if (!data[IFLA_GTP_PDP_HASHSIZE])
683 		hashsize = 1024;
684 	else
685 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
686 
687 	err = gtp_hashtable_new(gtp, hashsize);
688 	if (err < 0)
689 		goto out_encap;
690 
691 	err = register_netdevice(dev);
692 	if (err < 0) {
693 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
694 		goto out_hashtable;
695 	}
696 
697 	gn = net_generic(dev_net(dev), gtp_net_id);
698 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
699 
700 	netdev_dbg(dev, "registered new GTP interface\n");
701 
702 	return 0;
703 
704 out_hashtable:
705 	gtp_hashtable_free(gtp);
706 out_encap:
707 	gtp_encap_disable(gtp);
708 out_err:
709 	return err;
710 }
711 
712 static void gtp_dellink(struct net_device *dev, struct list_head *head)
713 {
714 	struct gtp_dev *gtp = netdev_priv(dev);
715 
716 	gtp_encap_disable(gtp);
717 	gtp_hashtable_free(gtp);
718 	list_del_rcu(&gtp->list);
719 	unregister_netdevice_queue(dev, head);
720 }
721 
722 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
723 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
724 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
725 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
726 };
727 
728 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
729 {
730 	if (!data)
731 		return -EINVAL;
732 
733 	return 0;
734 }
735 
736 static size_t gtp_get_size(const struct net_device *dev)
737 {
738 	return nla_total_size(sizeof(__u32));	/* IFLA_GTP_PDP_HASHSIZE */
739 }
740 
741 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
742 {
743 	struct gtp_dev *gtp = netdev_priv(dev);
744 
745 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
746 		goto nla_put_failure;
747 
748 	return 0;
749 
750 nla_put_failure:
751 	return -EMSGSIZE;
752 }
753 
754 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
755 	.kind		= "gtp",
756 	.maxtype	= IFLA_GTP_MAX,
757 	.policy		= gtp_policy,
758 	.priv_size	= sizeof(struct gtp_dev),
759 	.setup		= gtp_link_setup,
760 	.validate	= gtp_validate,
761 	.newlink	= gtp_newlink,
762 	.dellink	= gtp_dellink,
763 	.get_size	= gtp_get_size,
764 	.fill_info	= gtp_fill_info,
765 };
766 
767 static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[])
768 {
769 	struct net *net;
770 
771 	/* Examine the link attributes and figure out which network namespace
772 	 * we are talking about.
773 	 */
774 	if (tb[GTPA_NET_NS_FD])
775 		net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));
776 	else
777 		net = get_net(src_net);
778 
779 	return net;
780 }
781 
782 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
783 {
784 	int i;
785 
786 	gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
787 	if (gtp->addr_hash == NULL)
788 		return -ENOMEM;
789 
790 	gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
791 	if (gtp->tid_hash == NULL)
792 		goto err1;
793 
794 	gtp->hash_size = hsize;
795 
796 	for (i = 0; i < hsize; i++) {
797 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
798 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
799 	}
800 	return 0;
801 err1:
802 	kfree(gtp->addr_hash);
803 	return -ENOMEM;
804 }
805 
806 static void gtp_hashtable_free(struct gtp_dev *gtp)
807 {
808 	struct pdp_ctx *pctx;
809 	int i;
810 
811 	for (i = 0; i < gtp->hash_size; i++) {
812 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
813 			hlist_del_rcu(&pctx->hlist_tid);
814 			hlist_del_rcu(&pctx->hlist_addr);
815 			kfree_rcu(pctx, rcu_head);
816 		}
817 	}
818 	synchronize_rcu();
819 	kfree(gtp->addr_hash);
820 	kfree(gtp->tid_hash);
821 }
822 
823 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
824 			    int fd_gtp0, int fd_gtp1, struct net *src_net)
825 {
826 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
827 	struct socket *sock0, *sock1u;
828 	int err;
829 
830 	netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
831 
832 	sock0 = sockfd_lookup(fd_gtp0, &err);
833 	if (sock0 == NULL) {
834 		netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
835 		return -ENOENT;
836 	}
837 
838 	if (sock0->sk->sk_protocol != IPPROTO_UDP) {
839 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
840 		err = -EINVAL;
841 		goto err1;
842 	}
843 
844 	sock1u = sockfd_lookup(fd_gtp1, &err);
845 	if (sock1u == NULL) {
846 		netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
847 		err = -ENOENT;
848 		goto err1;
849 	}
850 
851 	if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
852 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
853 		err = -EINVAL;
854 		goto err2;
855 	}
856 
857 	netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
858 
859 	gtp->sock0 = sock0;
860 	gtp->sock1u = sock1u;
861 	gtp->net = src_net;
862 
863 	tuncfg.sk_user_data = gtp;
864 	tuncfg.encap_rcv = gtp_encap_recv;
865 	tuncfg.encap_destroy = gtp_encap_destroy;
866 
867 	tuncfg.encap_type = UDP_ENCAP_GTP0;
868 	setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
869 
870 	tuncfg.encap_type = UDP_ENCAP_GTP1U;
871 	setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
872 
873 	err = 0;
874 err2:
875 	sockfd_put(sock1u);
876 err1:
877 	sockfd_put(sock0);
878 	return err;
879 }
880 
881 static struct net_device *gtp_find_dev(struct net *net, int ifindex)
882 {
883 	struct gtp_net *gn = net_generic(net, gtp_net_id);
884 	struct gtp_dev *gtp;
885 
886 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
887 		if (ifindex == gtp->dev->ifindex)
888 			return gtp->dev;
889 	}
890 	return NULL;
891 }
892 
893 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
894 {
895 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
896 	pctx->af = AF_INET;
897 	pctx->sgsn_addr_ip4.s_addr =
898 		nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
899 	pctx->ms_addr_ip4.s_addr =
900 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
901 
902 	switch (pctx->gtp_version) {
903 	case GTP_V0:
904 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
905 		 * label needs to be the same for uplink and downlink packets,
906 		 * so let's annotate this.
907 		 */
908 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
909 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
910 		break;
911 	case GTP_V1:
912 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
913 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
914 		break;
915 	default:
916 		break;
917 	}
918 }
919 
920 static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
921 {
922 	struct gtp_dev *gtp = netdev_priv(dev);
923 	u32 hash_ms, hash_tid = 0;
924 	struct pdp_ctx *pctx;
925 	bool found = false;
926 	__be32 ms_addr;
927 
928 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
929 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
930 
931 	hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
932 		if (pctx->ms_addr_ip4.s_addr == ms_addr) {
933 			found = true;
934 			break;
935 		}
936 	}
937 
938 	if (found) {
939 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
940 			return -EEXIST;
941 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
942 			return -EOPNOTSUPP;
943 
944 		ipv4_pdp_fill(pctx, info);
945 
946 		if (pctx->gtp_version == GTP_V0)
947 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
948 				   pctx->u.v0.tid, pctx);
949 		else if (pctx->gtp_version == GTP_V1)
950 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
951 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
952 
953 		return 0;
954 
955 	}
956 
957 	pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
958 	if (pctx == NULL)
959 		return -ENOMEM;
960 
961 	ipv4_pdp_fill(pctx, info);
962 	atomic_set(&pctx->tx_seq, 0);
963 
964 	switch (pctx->gtp_version) {
965 	case GTP_V0:
966 		/* TS 09.60: "The flow label identifies unambiguously a GTP
967 		 * flow.". We use the tid for this instead, I cannot find a
968 		 * situation in which this doesn't unambiguosly identify the
969 		 * PDP context.
970 		 */
971 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
972 		break;
973 	case GTP_V1:
974 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
975 		break;
976 	}
977 
978 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
979 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
980 
981 	switch (pctx->gtp_version) {
982 	case GTP_V0:
983 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
984 			   pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
985 			   &pctx->ms_addr_ip4, pctx);
986 		break;
987 	case GTP_V1:
988 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
989 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
990 			   &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
991 		break;
992 	}
993 
994 	return 0;
995 }
996 
997 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
998 {
999 	struct net_device *dev;
1000 	struct net *net;
1001 
1002 	if (!info->attrs[GTPA_VERSION] ||
1003 	    !info->attrs[GTPA_LINK] ||
1004 	    !info->attrs[GTPA_SGSN_ADDRESS] ||
1005 	    !info->attrs[GTPA_MS_ADDRESS])
1006 		return -EINVAL;
1007 
1008 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1009 	case GTP_V0:
1010 		if (!info->attrs[GTPA_TID] ||
1011 		    !info->attrs[GTPA_FLOW])
1012 			return -EINVAL;
1013 		break;
1014 	case GTP_V1:
1015 		if (!info->attrs[GTPA_I_TEI] ||
1016 		    !info->attrs[GTPA_O_TEI])
1017 			return -EINVAL;
1018 		break;
1019 
1020 	default:
1021 		return -EINVAL;
1022 	}
1023 
1024 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1025 	if (IS_ERR(net))
1026 		return PTR_ERR(net);
1027 
1028 	/* Check if there's an existing gtpX device to configure */
1029 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1030 	if (dev == NULL) {
1031 		put_net(net);
1032 		return -ENODEV;
1033 	}
1034 	put_net(net);
1035 
1036 	return ipv4_pdp_add(dev, info);
1037 }
1038 
1039 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1040 {
1041 	struct net_device *dev;
1042 	struct pdp_ctx *pctx;
1043 	struct gtp_dev *gtp;
1044 	struct net *net;
1045 
1046 	if (!info->attrs[GTPA_VERSION] ||
1047 	    !info->attrs[GTPA_LINK])
1048 		return -EINVAL;
1049 
1050 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1051 	if (IS_ERR(net))
1052 		return PTR_ERR(net);
1053 
1054 	/* Check if there's an existing gtpX device to configure */
1055 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1056 	if (dev == NULL) {
1057 		put_net(net);
1058 		return -ENODEV;
1059 	}
1060 	put_net(net);
1061 
1062 	gtp = netdev_priv(dev);
1063 
1064 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1065 	case GTP_V0:
1066 		if (!info->attrs[GTPA_TID])
1067 			return -EINVAL;
1068 		pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
1069 		break;
1070 	case GTP_V1:
1071 		if (!info->attrs[GTPA_I_TEI])
1072 			return -EINVAL;
1073 		pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
1074 		break;
1075 
1076 	default:
1077 		return -EINVAL;
1078 	}
1079 
1080 	if (pctx == NULL)
1081 		return -ENOENT;
1082 
1083 	if (pctx->gtp_version == GTP_V0)
1084 		netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1085 			   pctx->u.v0.tid, pctx);
1086 	else if (pctx->gtp_version == GTP_V1)
1087 		netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1088 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1089 
1090 	hlist_del_rcu(&pctx->hlist_tid);
1091 	hlist_del_rcu(&pctx->hlist_addr);
1092 	kfree_rcu(pctx, rcu_head);
1093 
1094 	return 0;
1095 }
1096 
1097 static struct genl_family gtp_genl_family = {
1098 	.id		= GENL_ID_GENERATE,
1099 	.name		= "gtp",
1100 	.version	= 0,
1101 	.hdrsize	= 0,
1102 	.maxattr	= GTPA_MAX,
1103 	.netnsok	= true,
1104 };
1105 
1106 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1107 			      u32 type, struct pdp_ctx *pctx)
1108 {
1109 	void *genlh;
1110 
1111 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
1112 			    type);
1113 	if (genlh == NULL)
1114 		goto nlmsg_failure;
1115 
1116 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1117 	    nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) ||
1118 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1119 		goto nla_put_failure;
1120 
1121 	switch (pctx->gtp_version) {
1122 	case GTP_V0:
1123 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1124 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1125 			goto nla_put_failure;
1126 		break;
1127 	case GTP_V1:
1128 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1129 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1130 			goto nla_put_failure;
1131 		break;
1132 	}
1133 	genlmsg_end(skb, genlh);
1134 	return 0;
1135 
1136 nlmsg_failure:
1137 nla_put_failure:
1138 	genlmsg_cancel(skb, genlh);
1139 	return -EMSGSIZE;
1140 }
1141 
1142 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1143 {
1144 	struct pdp_ctx *pctx = NULL;
1145 	struct net_device *dev;
1146 	struct sk_buff *skb2;
1147 	struct gtp_dev *gtp;
1148 	u32 gtp_version;
1149 	struct net *net;
1150 	int err;
1151 
1152 	if (!info->attrs[GTPA_VERSION] ||
1153 	    !info->attrs[GTPA_LINK])
1154 		return -EINVAL;
1155 
1156 	gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1157 	switch (gtp_version) {
1158 	case GTP_V0:
1159 	case GTP_V1:
1160 		break;
1161 	default:
1162 		return -EINVAL;
1163 	}
1164 
1165 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1166 	if (IS_ERR(net))
1167 		return PTR_ERR(net);
1168 
1169 	/* Check if there's an existing gtpX device to configure */
1170 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1171 	if (dev == NULL) {
1172 		put_net(net);
1173 		return -ENODEV;
1174 	}
1175 	put_net(net);
1176 
1177 	gtp = netdev_priv(dev);
1178 
1179 	rcu_read_lock();
1180 	if (gtp_version == GTP_V0 &&
1181 	    info->attrs[GTPA_TID]) {
1182 		u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
1183 
1184 		pctx = gtp0_pdp_find(gtp, tid);
1185 	} else if (gtp_version == GTP_V1 &&
1186 		 info->attrs[GTPA_I_TEI]) {
1187 		u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
1188 
1189 		pctx = gtp1_pdp_find(gtp, tid);
1190 	} else if (info->attrs[GTPA_MS_ADDRESS]) {
1191 		__be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1192 
1193 		pctx = ipv4_pdp_find(gtp, ip);
1194 	}
1195 
1196 	if (pctx == NULL) {
1197 		err = -ENOENT;
1198 		goto err_unlock;
1199 	}
1200 
1201 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1202 	if (skb2 == NULL) {
1203 		err = -ENOMEM;
1204 		goto err_unlock;
1205 	}
1206 
1207 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1208 				 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1209 	if (err < 0)
1210 		goto err_unlock_free;
1211 
1212 	rcu_read_unlock();
1213 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1214 
1215 err_unlock_free:
1216 	kfree_skb(skb2);
1217 err_unlock:
1218 	rcu_read_unlock();
1219 	return err;
1220 }
1221 
1222 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1223 				struct netlink_callback *cb)
1224 {
1225 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1226 	struct net *net = sock_net(skb->sk);
1227 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1228 	unsigned long tid = cb->args[1];
1229 	int i, k = cb->args[0], ret;
1230 	struct pdp_ctx *pctx;
1231 
1232 	if (cb->args[4])
1233 		return 0;
1234 
1235 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1236 		if (last_gtp && last_gtp != gtp)
1237 			continue;
1238 		else
1239 			last_gtp = NULL;
1240 
1241 		for (i = k; i < gtp->hash_size; i++) {
1242 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
1243 				if (tid && tid != pctx->u.tid)
1244 					continue;
1245 				else
1246 					tid = 0;
1247 
1248 				ret = gtp_genl_fill_info(skb,
1249 							 NETLINK_CB(cb->skb).portid,
1250 							 cb->nlh->nlmsg_seq,
1251 							 cb->nlh->nlmsg_type, pctx);
1252 				if (ret < 0) {
1253 					cb->args[0] = i;
1254 					cb->args[1] = pctx->u.tid;
1255 					cb->args[2] = (unsigned long)gtp;
1256 					goto out;
1257 				}
1258 			}
1259 		}
1260 	}
1261 	cb->args[4] = 1;
1262 out:
1263 	return skb->len;
1264 }
1265 
1266 static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1267 	[GTPA_LINK]		= { .type = NLA_U32, },
1268 	[GTPA_VERSION]		= { .type = NLA_U32, },
1269 	[GTPA_TID]		= { .type = NLA_U64, },
1270 	[GTPA_SGSN_ADDRESS]	= { .type = NLA_U32, },
1271 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1272 	[GTPA_FLOW]		= { .type = NLA_U16, },
1273 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1274 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1275 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1276 };
1277 
1278 static const struct genl_ops gtp_genl_ops[] = {
1279 	{
1280 		.cmd = GTP_CMD_NEWPDP,
1281 		.doit = gtp_genl_new_pdp,
1282 		.policy = gtp_genl_policy,
1283 		.flags = GENL_ADMIN_PERM,
1284 	},
1285 	{
1286 		.cmd = GTP_CMD_DELPDP,
1287 		.doit = gtp_genl_del_pdp,
1288 		.policy = gtp_genl_policy,
1289 		.flags = GENL_ADMIN_PERM,
1290 	},
1291 	{
1292 		.cmd = GTP_CMD_GETPDP,
1293 		.doit = gtp_genl_get_pdp,
1294 		.dumpit = gtp_genl_dump_pdp,
1295 		.policy = gtp_genl_policy,
1296 		.flags = GENL_ADMIN_PERM,
1297 	},
1298 };
1299 
1300 static int __net_init gtp_net_init(struct net *net)
1301 {
1302 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1303 
1304 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1305 	return 0;
1306 }
1307 
1308 static void __net_exit gtp_net_exit(struct net *net)
1309 {
1310 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1311 	struct gtp_dev *gtp;
1312 	LIST_HEAD(list);
1313 
1314 	rtnl_lock();
1315 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1316 		gtp_dellink(gtp->dev, &list);
1317 
1318 	unregister_netdevice_many(&list);
1319 	rtnl_unlock();
1320 }
1321 
1322 static struct pernet_operations gtp_net_ops = {
1323 	.init	= gtp_net_init,
1324 	.exit	= gtp_net_exit,
1325 	.id	= &gtp_net_id,
1326 	.size	= sizeof(struct gtp_net),
1327 };
1328 
1329 static int __init gtp_init(void)
1330 {
1331 	int err;
1332 
1333 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1334 
1335 	err = rtnl_link_register(&gtp_link_ops);
1336 	if (err < 0)
1337 		goto error_out;
1338 
1339 	err = genl_register_family_with_ops(&gtp_genl_family, gtp_genl_ops);
1340 	if (err < 0)
1341 		goto unreg_rtnl_link;
1342 
1343 	err = register_pernet_subsys(&gtp_net_ops);
1344 	if (err < 0)
1345 		goto unreg_genl_family;
1346 
1347 	pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n",
1348 		sizeof(struct pdp_ctx));
1349 	return 0;
1350 
1351 unreg_genl_family:
1352 	genl_unregister_family(&gtp_genl_family);
1353 unreg_rtnl_link:
1354 	rtnl_link_unregister(&gtp_link_ops);
1355 error_out:
1356 	pr_err("error loading GTP module loaded\n");
1357 	return err;
1358 }
1359 late_initcall(gtp_init);
1360 
1361 static void __exit gtp_fini(void)
1362 {
1363 	unregister_pernet_subsys(&gtp_net_ops);
1364 	genl_unregister_family(&gtp_genl_family);
1365 	rtnl_link_unregister(&gtp_link_ops);
1366 
1367 	pr_info("GTP module unloaded\n");
1368 }
1369 module_exit(gtp_fini);
1370 
1371 MODULE_LICENSE("GPL");
1372 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1373 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1374 MODULE_ALIAS_RTNL_LINK("gtp");
1375