xref: /linux/drivers/net/gtp.c (revision 95db3b255fde4e830e5f8cc011eb404023f669d4)
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/version.h>
20 #include <linux/skbuff.h>
21 #include <linux/udp.h>
22 #include <linux/rculist.h>
23 #include <linux/jhash.h>
24 #include <linux/if_tunnel.h>
25 #include <linux/net.h>
26 #include <linux/file.h>
27 #include <linux/gtp.h>
28 
29 #include <net/net_namespace.h>
30 #include <net/protocol.h>
31 #include <net/ip.h>
32 #include <net/udp.h>
33 #include <net/udp_tunnel.h>
34 #include <net/icmp.h>
35 #include <net/xfrm.h>
36 #include <net/genetlink.h>
37 #include <net/netns/generic.h>
38 #include <net/gtp.h>
39 
40 /* An active session for the subscriber. */
41 struct pdp_ctx {
42 	struct hlist_node	hlist_tid;
43 	struct hlist_node	hlist_addr;
44 
45 	union {
46 		u64		tid;
47 		struct {
48 			u64	tid;
49 			u16	flow;
50 		} v0;
51 		struct {
52 			u32	i_tei;
53 			u32	o_tei;
54 		} v1;
55 	} u;
56 	u8			gtp_version;
57 	u16			af;
58 
59 	struct in_addr		ms_addr_ip4;
60 	struct in_addr		sgsn_addr_ip4;
61 
62 	atomic_t		tx_seq;
63 	struct rcu_head		rcu_head;
64 };
65 
66 /* One instance of the GTP device. */
67 struct gtp_dev {
68 	struct list_head	list;
69 
70 	struct socket		*sock0;
71 	struct socket		*sock1u;
72 
73 	struct net		*net;
74 	struct net_device	*dev;
75 
76 	unsigned int		hash_size;
77 	struct hlist_head	*tid_hash;
78 	struct hlist_head	*addr_hash;
79 };
80 
81 static int gtp_net_id __read_mostly;
82 
83 struct gtp_net {
84 	struct list_head gtp_dev_list;
85 };
86 
87 static u32 gtp_h_initval;
88 
89 static inline u32 gtp0_hashfn(u64 tid)
90 {
91 	u32 *tid32 = (u32 *) &tid;
92 	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
93 }
94 
95 static inline u32 gtp1u_hashfn(u32 tid)
96 {
97 	return jhash_1word(tid, gtp_h_initval);
98 }
99 
100 static inline u32 ipv4_hashfn(__be32 ip)
101 {
102 	return jhash_1word((__force u32)ip, gtp_h_initval);
103 }
104 
105 /* Resolve a PDP context structure based on the 64bit TID. */
106 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
107 {
108 	struct hlist_head *head;
109 	struct pdp_ctx *pdp;
110 
111 	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
112 
113 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
114 		if (pdp->gtp_version == GTP_V0 &&
115 		    pdp->u.v0.tid == tid)
116 			return pdp;
117 	}
118 	return NULL;
119 }
120 
121 /* Resolve a PDP context structure based on the 32bit TEI. */
122 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
123 {
124 	struct hlist_head *head;
125 	struct pdp_ctx *pdp;
126 
127 	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
128 
129 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
130 		if (pdp->gtp_version == GTP_V1 &&
131 		    pdp->u.v1.i_tei == tid)
132 			return pdp;
133 	}
134 	return NULL;
135 }
136 
137 /* Resolve a PDP context based on IPv4 address of MS. */
138 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
139 {
140 	struct hlist_head *head;
141 	struct pdp_ctx *pdp;
142 
143 	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
144 
145 	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
146 		if (pdp->af == AF_INET &&
147 		    pdp->ms_addr_ip4.s_addr == ms_addr)
148 			return pdp;
149 	}
150 
151 	return NULL;
152 }
153 
154 static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
155 				  unsigned int hdrlen)
156 {
157 	struct iphdr *iph;
158 
159 	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
160 		return false;
161 
162 	iph = (struct iphdr *)(skb->data + hdrlen + sizeof(struct iphdr));
163 
164 	return iph->saddr != pctx->ms_addr_ip4.s_addr;
165 }
166 
167 /* Check if the inner IP source address in this packet is assigned to any
168  * existing mobile subscriber.
169  */
170 static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
171 			     unsigned int hdrlen)
172 {
173 	switch (ntohs(skb->protocol)) {
174 	case ETH_P_IP:
175 		return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
176 	}
177 	return false;
178 }
179 
180 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
181 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
182 			       bool xnet)
183 {
184 	unsigned int hdrlen = sizeof(struct udphdr) +
185 			      sizeof(struct gtp0_header);
186 	struct gtp0_header *gtp0;
187 	struct pdp_ctx *pctx;
188 	int ret = 0;
189 
190 	if (!pskb_may_pull(skb, hdrlen))
191 		return -1;
192 
193 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
194 
195 	if ((gtp0->flags >> 5) != GTP_V0)
196 		return 1;
197 
198 	if (gtp0->type != GTP_TPDU)
199 		return 1;
200 
201 	rcu_read_lock();
202 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
203 	if (!pctx) {
204 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
205 		ret = -1;
206 		goto out_rcu;
207 	}
208 
209 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
210 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
211 		ret = -1;
212 		goto out_rcu;
213 	}
214 	rcu_read_unlock();
215 
216 	/* Get rid of the GTP + UDP headers. */
217 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
218 out_rcu:
219 	rcu_read_unlock();
220 	return ret;
221 }
222 
223 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
224 				bool xnet)
225 {
226 	unsigned int hdrlen = sizeof(struct udphdr) +
227 			      sizeof(struct gtp1_header);
228 	struct gtp1_header *gtp1;
229 	struct pdp_ctx *pctx;
230 	int ret = 0;
231 
232 	if (!pskb_may_pull(skb, hdrlen))
233 		return -1;
234 
235 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
236 
237 	if ((gtp1->flags >> 5) != GTP_V1)
238 		return 1;
239 
240 	if (gtp1->type != GTP_TPDU)
241 		return 1;
242 
243 	/* From 29.060: "This field shall be present if and only if any one or
244 	 * more of the S, PN and E flags are set.".
245 	 *
246 	 * If any of the bit is set, then the remaining ones also have to be
247 	 * set.
248 	 */
249 	if (gtp1->flags & GTP1_F_MASK)
250 		hdrlen += 4;
251 
252 	/* Make sure the header is larger enough, including extensions. */
253 	if (!pskb_may_pull(skb, hdrlen))
254 		return -1;
255 
256 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
257 
258 	rcu_read_lock();
259 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
260 	if (!pctx) {
261 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
262 		ret = -1;
263 		goto out_rcu;
264 	}
265 
266 	if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
267 		netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
268 		ret = -1;
269 		goto out_rcu;
270 	}
271 	rcu_read_unlock();
272 
273 	/* Get rid of the GTP + UDP headers. */
274 	return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
275 out_rcu:
276 	rcu_read_unlock();
277 	return ret;
278 }
279 
280 static void gtp_encap_disable(struct gtp_dev *gtp)
281 {
282 	if (gtp->sock0 && gtp->sock0->sk) {
283 		udp_sk(gtp->sock0->sk)->encap_type = 0;
284 		rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
285 	}
286 	if (gtp->sock1u && gtp->sock1u->sk) {
287 		udp_sk(gtp->sock1u->sk)->encap_type = 0;
288 		rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
289 	}
290 
291 	gtp->sock0 = NULL;
292 	gtp->sock1u = NULL;
293 }
294 
295 static void gtp_encap_destroy(struct sock *sk)
296 {
297 	struct gtp_dev *gtp;
298 
299 	gtp = rcu_dereference_sk_user_data(sk);
300 	if (gtp)
301 		gtp_encap_disable(gtp);
302 }
303 
304 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
305  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
306  */
307 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
308 {
309 	struct pcpu_sw_netstats *stats;
310 	struct gtp_dev *gtp;
311 	bool xnet;
312 	int ret;
313 
314 	gtp = rcu_dereference_sk_user_data(sk);
315 	if (!gtp)
316 		return 1;
317 
318 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
319 
320 	xnet = !net_eq(gtp->net, dev_net(gtp->dev));
321 
322 	switch (udp_sk(sk)->encap_type) {
323 	case UDP_ENCAP_GTP0:
324 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
325 		ret = gtp0_udp_encap_recv(gtp, skb, xnet);
326 		break;
327 	case UDP_ENCAP_GTP1U:
328 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
329 		ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
330 		break;
331 	default:
332 		ret = -1; /* Shouldn't happen. */
333 	}
334 
335 	switch (ret) {
336 	case 1:
337 		netdev_dbg(gtp->dev, "pass up to the process\n");
338 		return 1;
339 	case 0:
340 		netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
341 		break;
342 	case -1:
343 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
344 		kfree_skb(skb);
345 		return 0;
346 	}
347 
348 	/* Now that the UDP and the GTP header have been removed, set up the
349 	 * new network header. This is required by the upper layer to
350 	 * calculate the transport header.
351 	 */
352 	skb_reset_network_header(skb);
353 
354 	skb->dev = gtp->dev;
355 
356 	stats = this_cpu_ptr(gtp->dev->tstats);
357 	u64_stats_update_begin(&stats->syncp);
358 	stats->rx_packets++;
359 	stats->rx_bytes += skb->len;
360 	u64_stats_update_end(&stats->syncp);
361 
362 	netif_rx(skb);
363 
364 	return 0;
365 }
366 
367 static int gtp_dev_init(struct net_device *dev)
368 {
369 	struct gtp_dev *gtp = netdev_priv(dev);
370 
371 	gtp->dev = dev;
372 
373 	dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
374 	if (!dev->tstats)
375 		return -ENOMEM;
376 
377 	return 0;
378 }
379 
380 static void gtp_dev_uninit(struct net_device *dev)
381 {
382 	struct gtp_dev *gtp = netdev_priv(dev);
383 
384 	gtp_encap_disable(gtp);
385 	free_percpu(dev->tstats);
386 }
387 
388 static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
389 					   const struct sock *sk, __be32 daddr)
390 {
391 	memset(fl4, 0, sizeof(*fl4));
392 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
393 	fl4->daddr		= daddr;
394 	fl4->saddr		= inet_sk(sk)->inet_saddr;
395 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
396 	fl4->flowi4_proto	= sk->sk_protocol;
397 
398 	return ip_route_output_key(net, fl4);
399 }
400 
401 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
402 {
403 	int payload_len = skb->len;
404 	struct gtp0_header *gtp0;
405 
406 	gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
407 
408 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
409 	gtp0->type	= GTP_TPDU;
410 	gtp0->length	= htons(payload_len);
411 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
412 	gtp0->flow	= htons(pctx->u.v0.flow);
413 	gtp0->number	= 0xff;
414 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
415 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
416 }
417 
418 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
419 {
420 	int payload_len = skb->len;
421 	struct gtp1_header *gtp1;
422 
423 	gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
424 
425 	/* Bits    8  7  6  5  4  3  2	1
426 	 *	  +--+--+--+--+--+--+--+--+
427 	 *	  |version |PT| 1| E| S|PN|
428 	 *	  +--+--+--+--+--+--+--+--+
429 	 *	    0  0  1  1	1  0  0  0
430 	 */
431 	gtp1->flags	= 0x38; /* v1, GTP-non-prime. */
432 	gtp1->type	= GTP_TPDU;
433 	gtp1->length	= htons(payload_len);
434 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
435 
436 	/* TODO: Suppport for extension header, sequence number and N-PDU.
437 	 *	 Update the length field if any of them is available.
438 	 */
439 }
440 
441 struct gtp_pktinfo {
442 	struct sock		*sk;
443 	struct iphdr		*iph;
444 	struct flowi4		fl4;
445 	struct rtable		*rt;
446 	struct pdp_ctx		*pctx;
447 	struct net_device	*dev;
448 	__be16			gtph_port;
449 };
450 
451 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
452 {
453 	switch (pktinfo->pctx->gtp_version) {
454 	case GTP_V0:
455 		pktinfo->gtph_port = htons(GTP0_PORT);
456 		gtp0_push_header(skb, pktinfo->pctx);
457 		break;
458 	case GTP_V1:
459 		pktinfo->gtph_port = htons(GTP1U_PORT);
460 		gtp1_push_header(skb, pktinfo->pctx);
461 		break;
462 	}
463 }
464 
465 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
466 					struct sock *sk, struct iphdr *iph,
467 					struct pdp_ctx *pctx, struct rtable *rt,
468 					struct flowi4 *fl4,
469 					struct net_device *dev)
470 {
471 	pktinfo->sk	= sk;
472 	pktinfo->iph	= iph;
473 	pktinfo->pctx	= pctx;
474 	pktinfo->rt	= rt;
475 	pktinfo->fl4	= *fl4;
476 	pktinfo->dev	= dev;
477 }
478 
479 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
480 			     struct gtp_pktinfo *pktinfo)
481 {
482 	struct gtp_dev *gtp = netdev_priv(dev);
483 	struct pdp_ctx *pctx;
484 	struct rtable *rt;
485 	struct flowi4 fl4;
486 	struct iphdr *iph;
487 	struct sock *sk;
488 	__be16 df;
489 	int mtu;
490 
491 	/* Read the IP destination address and resolve the PDP context.
492 	 * Prepend PDP header with TEI/TID from PDP ctx.
493 	 */
494 	iph = ip_hdr(skb);
495 	pctx = ipv4_pdp_find(gtp, iph->daddr);
496 	if (!pctx) {
497 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
498 			   &iph->daddr);
499 		return -ENOENT;
500 	}
501 	netdev_dbg(dev, "found PDP context %p\n", pctx);
502 
503 	switch (pctx->gtp_version) {
504 	case GTP_V0:
505 		if (gtp->sock0)
506 			sk = gtp->sock0->sk;
507 		else
508 			sk = NULL;
509 		break;
510 	case GTP_V1:
511 		if (gtp->sock1u)
512 			sk = gtp->sock1u->sk;
513 		else
514 			sk = NULL;
515 		break;
516 	default:
517 		return -ENOENT;
518 	}
519 
520 	if (!sk) {
521 		netdev_dbg(dev, "no userspace socket is available, skip\n");
522 		return -ENOENT;
523 	}
524 
525 	rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
526 				  pctx->sgsn_addr_ip4.s_addr);
527 	if (IS_ERR(rt)) {
528 		netdev_dbg(dev, "no route to SSGN %pI4\n",
529 			   &pctx->sgsn_addr_ip4.s_addr);
530 		dev->stats.tx_carrier_errors++;
531 		goto err;
532 	}
533 
534 	if (rt->dst.dev == dev) {
535 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
536 			   &pctx->sgsn_addr_ip4.s_addr);
537 		dev->stats.collisions++;
538 		goto err_rt;
539 	}
540 
541 	skb_dst_drop(skb);
542 
543 	/* This is similar to tnl_update_pmtu(). */
544 	df = iph->frag_off;
545 	if (df) {
546 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
547 			sizeof(struct iphdr) - sizeof(struct udphdr);
548 		switch (pctx->gtp_version) {
549 		case GTP_V0:
550 			mtu -= sizeof(struct gtp0_header);
551 			break;
552 		case GTP_V1:
553 			mtu -= sizeof(struct gtp1_header);
554 			break;
555 		}
556 	} else {
557 		mtu = dst_mtu(&rt->dst);
558 	}
559 
560 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
561 
562 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
563 	    mtu < ntohs(iph->tot_len)) {
564 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
565 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
566 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
567 			  htonl(mtu));
568 		goto err_rt;
569 	}
570 
571 	gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
572 	gtp_push_header(skb, pktinfo);
573 
574 	return 0;
575 err_rt:
576 	ip_rt_put(rt);
577 err:
578 	return -EBADMSG;
579 }
580 
581 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
582 {
583 	unsigned int proto = ntohs(skb->protocol);
584 	struct gtp_pktinfo pktinfo;
585 	int err;
586 
587 	/* Ensure there is sufficient headroom. */
588 	if (skb_cow_head(skb, dev->needed_headroom))
589 		goto tx_err;
590 
591 	skb_reset_inner_headers(skb);
592 
593 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
594 	rcu_read_lock();
595 	switch (proto) {
596 	case ETH_P_IP:
597 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
598 		break;
599 	default:
600 		err = -EOPNOTSUPP;
601 		break;
602 	}
603 	rcu_read_unlock();
604 
605 	if (err < 0)
606 		goto tx_err;
607 
608 	switch (proto) {
609 	case ETH_P_IP:
610 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
611 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
612 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
613 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
614 				    pktinfo.iph->tos,
615 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
616 				    htons(IP_DF),
617 				    pktinfo.gtph_port, pktinfo.gtph_port,
618 				    true, false);
619 		break;
620 	}
621 
622 	return NETDEV_TX_OK;
623 tx_err:
624 	dev->stats.tx_errors++;
625 	dev_kfree_skb(skb);
626 	return NETDEV_TX_OK;
627 }
628 
629 static const struct net_device_ops gtp_netdev_ops = {
630 	.ndo_init		= gtp_dev_init,
631 	.ndo_uninit		= gtp_dev_uninit,
632 	.ndo_start_xmit		= gtp_dev_xmit,
633 	.ndo_get_stats64	= ip_tunnel_get_stats64,
634 };
635 
636 static void gtp_link_setup(struct net_device *dev)
637 {
638 	dev->netdev_ops		= &gtp_netdev_ops;
639 	dev->destructor		= free_netdev;
640 
641 	dev->hard_header_len = 0;
642 	dev->addr_len = 0;
643 
644 	/* Zero header length. */
645 	dev->type = ARPHRD_NONE;
646 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
647 
648 	dev->priv_flags	|= IFF_NO_QUEUE;
649 	dev->features	|= NETIF_F_LLTX;
650 	netif_keep_dst(dev);
651 
652 	/* Assume largest header, ie. GTPv0. */
653 	dev->needed_headroom	= LL_MAX_HEADER +
654 				  sizeof(struct iphdr) +
655 				  sizeof(struct udphdr) +
656 				  sizeof(struct gtp0_header);
657 }
658 
659 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
660 static void gtp_hashtable_free(struct gtp_dev *gtp);
661 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
662 			    int fd_gtp0, int fd_gtp1, struct net *src_net);
663 
664 static int gtp_newlink(struct net *src_net, struct net_device *dev,
665 			struct nlattr *tb[], struct nlattr *data[])
666 {
667 	int hashsize, err, fd0, fd1;
668 	struct gtp_dev *gtp;
669 	struct gtp_net *gn;
670 
671 	if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
672 		return -EINVAL;
673 
674 	gtp = netdev_priv(dev);
675 
676 	fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
677 	fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
678 
679 	err = gtp_encap_enable(dev, gtp, fd0, fd1, src_net);
680 	if (err < 0)
681 		goto out_err;
682 
683 	if (!data[IFLA_GTP_PDP_HASHSIZE])
684 		hashsize = 1024;
685 	else
686 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
687 
688 	err = gtp_hashtable_new(gtp, hashsize);
689 	if (err < 0)
690 		goto out_encap;
691 
692 	err = register_netdevice(dev);
693 	if (err < 0) {
694 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
695 		goto out_hashtable;
696 	}
697 
698 	gn = net_generic(dev_net(dev), gtp_net_id);
699 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
700 
701 	netdev_dbg(dev, "registered new GTP interface\n");
702 
703 	return 0;
704 
705 out_hashtable:
706 	gtp_hashtable_free(gtp);
707 out_encap:
708 	gtp_encap_disable(gtp);
709 out_err:
710 	return err;
711 }
712 
713 static void gtp_dellink(struct net_device *dev, struct list_head *head)
714 {
715 	struct gtp_dev *gtp = netdev_priv(dev);
716 
717 	gtp_encap_disable(gtp);
718 	gtp_hashtable_free(gtp);
719 	list_del_rcu(&gtp->list);
720 	unregister_netdevice_queue(dev, head);
721 }
722 
723 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
724 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
725 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
726 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
727 };
728 
729 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
730 {
731 	if (!data)
732 		return -EINVAL;
733 
734 	return 0;
735 }
736 
737 static size_t gtp_get_size(const struct net_device *dev)
738 {
739 	return nla_total_size(sizeof(__u32));	/* IFLA_GTP_PDP_HASHSIZE */
740 }
741 
742 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
743 {
744 	struct gtp_dev *gtp = netdev_priv(dev);
745 
746 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
747 		goto nla_put_failure;
748 
749 	return 0;
750 
751 nla_put_failure:
752 	return -EMSGSIZE;
753 }
754 
755 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
756 	.kind		= "gtp",
757 	.maxtype	= IFLA_GTP_MAX,
758 	.policy		= gtp_policy,
759 	.priv_size	= sizeof(struct gtp_dev),
760 	.setup		= gtp_link_setup,
761 	.validate	= gtp_validate,
762 	.newlink	= gtp_newlink,
763 	.dellink	= gtp_dellink,
764 	.get_size	= gtp_get_size,
765 	.fill_info	= gtp_fill_info,
766 };
767 
768 static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[])
769 {
770 	struct net *net;
771 
772 	/* Examine the link attributes and figure out which network namespace
773 	 * we are talking about.
774 	 */
775 	if (tb[GTPA_NET_NS_FD])
776 		net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));
777 	else
778 		net = get_net(src_net);
779 
780 	return net;
781 }
782 
783 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
784 {
785 	int i;
786 
787 	gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
788 	if (gtp->addr_hash == NULL)
789 		return -ENOMEM;
790 
791 	gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
792 	if (gtp->tid_hash == NULL)
793 		goto err1;
794 
795 	gtp->hash_size = hsize;
796 
797 	for (i = 0; i < hsize; i++) {
798 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
799 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
800 	}
801 	return 0;
802 err1:
803 	kfree(gtp->addr_hash);
804 	return -ENOMEM;
805 }
806 
807 static void gtp_hashtable_free(struct gtp_dev *gtp)
808 {
809 	struct pdp_ctx *pctx;
810 	int i;
811 
812 	for (i = 0; i < gtp->hash_size; i++) {
813 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
814 			hlist_del_rcu(&pctx->hlist_tid);
815 			hlist_del_rcu(&pctx->hlist_addr);
816 			kfree_rcu(pctx, rcu_head);
817 		}
818 	}
819 	synchronize_rcu();
820 	kfree(gtp->addr_hash);
821 	kfree(gtp->tid_hash);
822 }
823 
824 static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
825 			    int fd_gtp0, int fd_gtp1, struct net *src_net)
826 {
827 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
828 	struct socket *sock0, *sock1u;
829 	int err;
830 
831 	netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
832 
833 	sock0 = sockfd_lookup(fd_gtp0, &err);
834 	if (sock0 == NULL) {
835 		netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
836 		return -ENOENT;
837 	}
838 
839 	if (sock0->sk->sk_protocol != IPPROTO_UDP) {
840 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
841 		err = -EINVAL;
842 		goto err1;
843 	}
844 
845 	sock1u = sockfd_lookup(fd_gtp1, &err);
846 	if (sock1u == NULL) {
847 		netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
848 		err = -ENOENT;
849 		goto err1;
850 	}
851 
852 	if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
853 		netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
854 		err = -EINVAL;
855 		goto err2;
856 	}
857 
858 	netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
859 
860 	gtp->sock0 = sock0;
861 	gtp->sock1u = sock1u;
862 	gtp->net = src_net;
863 
864 	tuncfg.sk_user_data = gtp;
865 	tuncfg.encap_rcv = gtp_encap_recv;
866 	tuncfg.encap_destroy = gtp_encap_destroy;
867 
868 	tuncfg.encap_type = UDP_ENCAP_GTP0;
869 	setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
870 
871 	tuncfg.encap_type = UDP_ENCAP_GTP1U;
872 	setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
873 
874 	err = 0;
875 err2:
876 	sockfd_put(sock1u);
877 err1:
878 	sockfd_put(sock0);
879 	return err;
880 }
881 
882 static struct net_device *gtp_find_dev(struct net *net, int ifindex)
883 {
884 	struct gtp_net *gn = net_generic(net, gtp_net_id);
885 	struct gtp_dev *gtp;
886 
887 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
888 		if (ifindex == gtp->dev->ifindex)
889 			return gtp->dev;
890 	}
891 	return NULL;
892 }
893 
894 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
895 {
896 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
897 	pctx->af = AF_INET;
898 	pctx->sgsn_addr_ip4.s_addr =
899 		nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
900 	pctx->ms_addr_ip4.s_addr =
901 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
902 
903 	switch (pctx->gtp_version) {
904 	case GTP_V0:
905 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
906 		 * label needs to be the same for uplink and downlink packets,
907 		 * so let's annotate this.
908 		 */
909 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
910 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
911 		break;
912 	case GTP_V1:
913 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
914 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
915 		break;
916 	default:
917 		break;
918 	}
919 }
920 
921 static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
922 {
923 	struct gtp_dev *gtp = netdev_priv(dev);
924 	u32 hash_ms, hash_tid = 0;
925 	struct pdp_ctx *pctx;
926 	bool found = false;
927 	__be32 ms_addr;
928 
929 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
930 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
931 
932 	hlist_for_each_entry_rcu(pctx, &gtp->addr_hash[hash_ms], hlist_addr) {
933 		if (pctx->ms_addr_ip4.s_addr == ms_addr) {
934 			found = true;
935 			break;
936 		}
937 	}
938 
939 	if (found) {
940 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
941 			return -EEXIST;
942 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
943 			return -EOPNOTSUPP;
944 
945 		ipv4_pdp_fill(pctx, info);
946 
947 		if (pctx->gtp_version == GTP_V0)
948 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
949 				   pctx->u.v0.tid, pctx);
950 		else if (pctx->gtp_version == GTP_V1)
951 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
952 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
953 
954 		return 0;
955 
956 	}
957 
958 	pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
959 	if (pctx == NULL)
960 		return -ENOMEM;
961 
962 	ipv4_pdp_fill(pctx, info);
963 	atomic_set(&pctx->tx_seq, 0);
964 
965 	switch (pctx->gtp_version) {
966 	case GTP_V0:
967 		/* TS 09.60: "The flow label identifies unambiguously a GTP
968 		 * flow.". We use the tid for this instead, I cannot find a
969 		 * situation in which this doesn't unambiguosly identify the
970 		 * PDP context.
971 		 */
972 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
973 		break;
974 	case GTP_V1:
975 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
976 		break;
977 	}
978 
979 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
980 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
981 
982 	switch (pctx->gtp_version) {
983 	case GTP_V0:
984 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
985 			   pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
986 			   &pctx->ms_addr_ip4, pctx);
987 		break;
988 	case GTP_V1:
989 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
990 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
991 			   &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
992 		break;
993 	}
994 
995 	return 0;
996 }
997 
998 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
999 {
1000 	struct net_device *dev;
1001 	struct net *net;
1002 
1003 	if (!info->attrs[GTPA_VERSION] ||
1004 	    !info->attrs[GTPA_LINK] ||
1005 	    !info->attrs[GTPA_SGSN_ADDRESS] ||
1006 	    !info->attrs[GTPA_MS_ADDRESS])
1007 		return -EINVAL;
1008 
1009 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1010 	case GTP_V0:
1011 		if (!info->attrs[GTPA_TID] ||
1012 		    !info->attrs[GTPA_FLOW])
1013 			return -EINVAL;
1014 		break;
1015 	case GTP_V1:
1016 		if (!info->attrs[GTPA_I_TEI] ||
1017 		    !info->attrs[GTPA_O_TEI])
1018 			return -EINVAL;
1019 		break;
1020 
1021 	default:
1022 		return -EINVAL;
1023 	}
1024 
1025 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1026 	if (IS_ERR(net))
1027 		return PTR_ERR(net);
1028 
1029 	/* Check if there's an existing gtpX device to configure */
1030 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1031 	if (dev == NULL) {
1032 		put_net(net);
1033 		return -ENODEV;
1034 	}
1035 	put_net(net);
1036 
1037 	return ipv4_pdp_add(dev, info);
1038 }
1039 
1040 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1041 {
1042 	struct net_device *dev;
1043 	struct pdp_ctx *pctx;
1044 	struct gtp_dev *gtp;
1045 	struct net *net;
1046 
1047 	if (!info->attrs[GTPA_VERSION] ||
1048 	    !info->attrs[GTPA_LINK])
1049 		return -EINVAL;
1050 
1051 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1052 	if (IS_ERR(net))
1053 		return PTR_ERR(net);
1054 
1055 	/* Check if there's an existing gtpX device to configure */
1056 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1057 	if (dev == NULL) {
1058 		put_net(net);
1059 		return -ENODEV;
1060 	}
1061 	put_net(net);
1062 
1063 	gtp = netdev_priv(dev);
1064 
1065 	switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1066 	case GTP_V0:
1067 		if (!info->attrs[GTPA_TID])
1068 			return -EINVAL;
1069 		pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
1070 		break;
1071 	case GTP_V1:
1072 		if (!info->attrs[GTPA_I_TEI])
1073 			return -EINVAL;
1074 		pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
1075 		break;
1076 
1077 	default:
1078 		return -EINVAL;
1079 	}
1080 
1081 	if (pctx == NULL)
1082 		return -ENOENT;
1083 
1084 	if (pctx->gtp_version == GTP_V0)
1085 		netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1086 			   pctx->u.v0.tid, pctx);
1087 	else if (pctx->gtp_version == GTP_V1)
1088 		netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1089 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1090 
1091 	hlist_del_rcu(&pctx->hlist_tid);
1092 	hlist_del_rcu(&pctx->hlist_addr);
1093 	kfree_rcu(pctx, rcu_head);
1094 
1095 	return 0;
1096 }
1097 
1098 static struct genl_family gtp_genl_family = {
1099 	.id		= GENL_ID_GENERATE,
1100 	.name		= "gtp",
1101 	.version	= 0,
1102 	.hdrsize	= 0,
1103 	.maxattr	= GTPA_MAX,
1104 	.netnsok	= true,
1105 };
1106 
1107 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1108 			      u32 type, struct pdp_ctx *pctx)
1109 {
1110 	void *genlh;
1111 
1112 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, 0,
1113 			    type);
1114 	if (genlh == NULL)
1115 		goto nlmsg_failure;
1116 
1117 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1118 	    nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) ||
1119 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1120 		goto nla_put_failure;
1121 
1122 	switch (pctx->gtp_version) {
1123 	case GTP_V0:
1124 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1125 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1126 			goto nla_put_failure;
1127 		break;
1128 	case GTP_V1:
1129 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1130 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1131 			goto nla_put_failure;
1132 		break;
1133 	}
1134 	genlmsg_end(skb, genlh);
1135 	return 0;
1136 
1137 nlmsg_failure:
1138 nla_put_failure:
1139 	genlmsg_cancel(skb, genlh);
1140 	return -EMSGSIZE;
1141 }
1142 
1143 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1144 {
1145 	struct pdp_ctx *pctx = NULL;
1146 	struct net_device *dev;
1147 	struct sk_buff *skb2;
1148 	struct gtp_dev *gtp;
1149 	u32 gtp_version;
1150 	struct net *net;
1151 	int err;
1152 
1153 	if (!info->attrs[GTPA_VERSION] ||
1154 	    !info->attrs[GTPA_LINK])
1155 		return -EINVAL;
1156 
1157 	gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1158 	switch (gtp_version) {
1159 	case GTP_V0:
1160 	case GTP_V1:
1161 		break;
1162 	default:
1163 		return -EINVAL;
1164 	}
1165 
1166 	net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1167 	if (IS_ERR(net))
1168 		return PTR_ERR(net);
1169 
1170 	/* Check if there's an existing gtpX device to configure */
1171 	dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1172 	if (dev == NULL) {
1173 		put_net(net);
1174 		return -ENODEV;
1175 	}
1176 	put_net(net);
1177 
1178 	gtp = netdev_priv(dev);
1179 
1180 	rcu_read_lock();
1181 	if (gtp_version == GTP_V0 &&
1182 	    info->attrs[GTPA_TID]) {
1183 		u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
1184 
1185 		pctx = gtp0_pdp_find(gtp, tid);
1186 	} else if (gtp_version == GTP_V1 &&
1187 		 info->attrs[GTPA_I_TEI]) {
1188 		u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
1189 
1190 		pctx = gtp1_pdp_find(gtp, tid);
1191 	} else if (info->attrs[GTPA_MS_ADDRESS]) {
1192 		__be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1193 
1194 		pctx = ipv4_pdp_find(gtp, ip);
1195 	}
1196 
1197 	if (pctx == NULL) {
1198 		err = -ENOENT;
1199 		goto err_unlock;
1200 	}
1201 
1202 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1203 	if (skb2 == NULL) {
1204 		err = -ENOMEM;
1205 		goto err_unlock;
1206 	}
1207 
1208 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1209 				 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1210 	if (err < 0)
1211 		goto err_unlock_free;
1212 
1213 	rcu_read_unlock();
1214 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1215 
1216 err_unlock_free:
1217 	kfree_skb(skb2);
1218 err_unlock:
1219 	rcu_read_unlock();
1220 	return err;
1221 }
1222 
1223 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1224 				struct netlink_callback *cb)
1225 {
1226 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1227 	struct net *net = sock_net(skb->sk);
1228 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1229 	unsigned long tid = cb->args[1];
1230 	int i, k = cb->args[0], ret;
1231 	struct pdp_ctx *pctx;
1232 
1233 	if (cb->args[4])
1234 		return 0;
1235 
1236 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1237 		if (last_gtp && last_gtp != gtp)
1238 			continue;
1239 		else
1240 			last_gtp = NULL;
1241 
1242 		for (i = k; i < gtp->hash_size; i++) {
1243 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid) {
1244 				if (tid && tid != pctx->u.tid)
1245 					continue;
1246 				else
1247 					tid = 0;
1248 
1249 				ret = gtp_genl_fill_info(skb,
1250 							 NETLINK_CB(cb->skb).portid,
1251 							 cb->nlh->nlmsg_seq,
1252 							 cb->nlh->nlmsg_type, pctx);
1253 				if (ret < 0) {
1254 					cb->args[0] = i;
1255 					cb->args[1] = pctx->u.tid;
1256 					cb->args[2] = (unsigned long)gtp;
1257 					goto out;
1258 				}
1259 			}
1260 		}
1261 	}
1262 	cb->args[4] = 1;
1263 out:
1264 	return skb->len;
1265 }
1266 
1267 static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1268 	[GTPA_LINK]		= { .type = NLA_U32, },
1269 	[GTPA_VERSION]		= { .type = NLA_U32, },
1270 	[GTPA_TID]		= { .type = NLA_U64, },
1271 	[GTPA_SGSN_ADDRESS]	= { .type = NLA_U32, },
1272 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1273 	[GTPA_FLOW]		= { .type = NLA_U16, },
1274 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1275 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1276 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1277 };
1278 
1279 static const struct genl_ops gtp_genl_ops[] = {
1280 	{
1281 		.cmd = GTP_CMD_NEWPDP,
1282 		.doit = gtp_genl_new_pdp,
1283 		.policy = gtp_genl_policy,
1284 		.flags = GENL_ADMIN_PERM,
1285 	},
1286 	{
1287 		.cmd = GTP_CMD_DELPDP,
1288 		.doit = gtp_genl_del_pdp,
1289 		.policy = gtp_genl_policy,
1290 		.flags = GENL_ADMIN_PERM,
1291 	},
1292 	{
1293 		.cmd = GTP_CMD_GETPDP,
1294 		.doit = gtp_genl_get_pdp,
1295 		.dumpit = gtp_genl_dump_pdp,
1296 		.policy = gtp_genl_policy,
1297 		.flags = GENL_ADMIN_PERM,
1298 	},
1299 };
1300 
1301 static int __net_init gtp_net_init(struct net *net)
1302 {
1303 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1304 
1305 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1306 	return 0;
1307 }
1308 
1309 static void __net_exit gtp_net_exit(struct net *net)
1310 {
1311 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1312 	struct gtp_dev *gtp;
1313 	LIST_HEAD(list);
1314 
1315 	rtnl_lock();
1316 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1317 		gtp_dellink(gtp->dev, &list);
1318 
1319 	unregister_netdevice_many(&list);
1320 	rtnl_unlock();
1321 }
1322 
1323 static struct pernet_operations gtp_net_ops = {
1324 	.init	= gtp_net_init,
1325 	.exit	= gtp_net_exit,
1326 	.id	= &gtp_net_id,
1327 	.size	= sizeof(struct gtp_net),
1328 };
1329 
1330 static int __init gtp_init(void)
1331 {
1332 	int err;
1333 
1334 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1335 
1336 	err = rtnl_link_register(&gtp_link_ops);
1337 	if (err < 0)
1338 		goto error_out;
1339 
1340 	err = genl_register_family_with_ops(&gtp_genl_family, gtp_genl_ops);
1341 	if (err < 0)
1342 		goto unreg_rtnl_link;
1343 
1344 	err = register_pernet_subsys(&gtp_net_ops);
1345 	if (err < 0)
1346 		goto unreg_genl_family;
1347 
1348 	pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n",
1349 		sizeof(struct pdp_ctx));
1350 	return 0;
1351 
1352 unreg_genl_family:
1353 	genl_unregister_family(&gtp_genl_family);
1354 unreg_rtnl_link:
1355 	rtnl_link_unregister(&gtp_link_ops);
1356 error_out:
1357 	pr_err("error loading GTP module loaded\n");
1358 	return err;
1359 }
1360 late_initcall(gtp_init);
1361 
1362 static void __exit gtp_fini(void)
1363 {
1364 	unregister_pernet_subsys(&gtp_net_ops);
1365 	genl_unregister_family(&gtp_genl_family);
1366 	rtnl_link_unregister(&gtp_link_ops);
1367 
1368 	pr_info("GTP module unloaded\n");
1369 }
1370 module_exit(gtp_fini);
1371 
1372 MODULE_LICENSE("GPL");
1373 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1374 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1375 MODULE_ALIAS_RTNL_LINK("gtp");
1376