xref: /openbmc/linux/drivers/net/gtp.c (revision 0936cdfb)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060
3  *
4  * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
5  * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
6  *
7  * Author: Harald Welte <hwelte@sysmocom.de>
8  *	   Pablo Neira Ayuso <pablo@netfilter.org>
9  *	   Andreas Schultz <aschultz@travelping.com>
10  */
11 
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13 
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/udp.h>
17 #include <linux/rculist.h>
18 #include <linux/jhash.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/net.h>
21 #include <linux/file.h>
22 #include <linux/gtp.h>
23 
24 #include <net/net_namespace.h>
25 #include <net/protocol.h>
26 #include <net/ip.h>
27 #include <net/udp.h>
28 #include <net/udp_tunnel.h>
29 #include <net/icmp.h>
30 #include <net/xfrm.h>
31 #include <net/genetlink.h>
32 #include <net/netns/generic.h>
33 #include <net/gtp.h>
34 
35 /* An active session for the subscriber. */
36 struct pdp_ctx {
37 	struct hlist_node	hlist_tid;
38 	struct hlist_node	hlist_addr;
39 
40 	union {
41 		struct {
42 			u64	tid;
43 			u16	flow;
44 		} v0;
45 		struct {
46 			u32	i_tei;
47 			u32	o_tei;
48 		} v1;
49 	} u;
50 	u8			gtp_version;
51 	u16			af;
52 
53 	struct in_addr		ms_addr_ip4;
54 	struct in_addr		peer_addr_ip4;
55 
56 	struct sock		*sk;
57 	struct net_device       *dev;
58 
59 	atomic_t		tx_seq;
60 	struct rcu_head		rcu_head;
61 };
62 
63 /* One instance of the GTP device. */
64 struct gtp_dev {
65 	struct list_head	list;
66 
67 	struct sock		*sk0;
68 	struct sock		*sk1u;
69 
70 	struct net_device	*dev;
71 
72 	unsigned int		role;
73 	unsigned int		hash_size;
74 	struct hlist_head	*tid_hash;
75 	struct hlist_head	*addr_hash;
76 };
77 
78 static unsigned int gtp_net_id __read_mostly;
79 
80 struct gtp_net {
81 	struct list_head gtp_dev_list;
82 };
83 
84 static u32 gtp_h_initval;
85 
86 static void pdp_context_delete(struct pdp_ctx *pctx);
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_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
154 				  unsigned int hdrlen, unsigned int role)
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);
162 
163 	if (role == GTP_ROLE_SGSN)
164 		return iph->daddr == pctx->ms_addr_ip4.s_addr;
165 	else
166 		return iph->saddr == pctx->ms_addr_ip4.s_addr;
167 }
168 
169 /* Check if the inner IP address in this packet is assigned to any
170  * existing mobile subscriber.
171  */
172 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
173 			     unsigned int hdrlen, unsigned int role)
174 {
175 	switch (ntohs(skb->protocol)) {
176 	case ETH_P_IP:
177 		return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
178 	}
179 	return false;
180 }
181 
182 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
183 			unsigned int hdrlen, unsigned int role)
184 {
185 	struct pcpu_sw_netstats *stats;
186 
187 	if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
188 		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
189 		return 1;
190 	}
191 
192 	/* Get rid of the GTP + UDP headers. */
193 	if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
194 				 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
195 		return -1;
196 
197 	netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
198 
199 	/* Now that the UDP and the GTP header have been removed, set up the
200 	 * new network header. This is required by the upper layer to
201 	 * calculate the transport header.
202 	 */
203 	skb_reset_network_header(skb);
204 
205 	skb->dev = pctx->dev;
206 
207 	stats = this_cpu_ptr(pctx->dev->tstats);
208 	u64_stats_update_begin(&stats->syncp);
209 	stats->rx_packets++;
210 	stats->rx_bytes += skb->len;
211 	u64_stats_update_end(&stats->syncp);
212 
213 	netif_rx(skb);
214 	return 0;
215 }
216 
217 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
218 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
219 {
220 	unsigned int hdrlen = sizeof(struct udphdr) +
221 			      sizeof(struct gtp0_header);
222 	struct gtp0_header *gtp0;
223 	struct pdp_ctx *pctx;
224 
225 	if (!pskb_may_pull(skb, hdrlen))
226 		return -1;
227 
228 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
229 
230 	if ((gtp0->flags >> 5) != GTP_V0)
231 		return 1;
232 
233 	if (gtp0->type != GTP_TPDU)
234 		return 1;
235 
236 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
237 	if (!pctx) {
238 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
239 		return 1;
240 	}
241 
242 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
243 }
244 
245 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
246 {
247 	unsigned int hdrlen = sizeof(struct udphdr) +
248 			      sizeof(struct gtp1_header);
249 	struct gtp1_header *gtp1;
250 	struct pdp_ctx *pctx;
251 
252 	if (!pskb_may_pull(skb, hdrlen))
253 		return -1;
254 
255 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
256 
257 	if ((gtp1->flags >> 5) != GTP_V1)
258 		return 1;
259 
260 	if (gtp1->type != GTP_TPDU)
261 		return 1;
262 
263 	/* From 29.060: "This field shall be present if and only if any one or
264 	 * more of the S, PN and E flags are set.".
265 	 *
266 	 * If any of the bit is set, then the remaining ones also have to be
267 	 * set.
268 	 */
269 	if (gtp1->flags & GTP1_F_MASK)
270 		hdrlen += 4;
271 
272 	/* Make sure the header is larger enough, including extensions. */
273 	if (!pskb_may_pull(skb, hdrlen))
274 		return -1;
275 
276 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
277 
278 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
279 	if (!pctx) {
280 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
281 		return 1;
282 	}
283 
284 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
285 }
286 
287 static void __gtp_encap_destroy(struct sock *sk)
288 {
289 	struct gtp_dev *gtp;
290 
291 	lock_sock(sk);
292 	gtp = sk->sk_user_data;
293 	if (gtp) {
294 		if (gtp->sk0 == sk)
295 			gtp->sk0 = NULL;
296 		else
297 			gtp->sk1u = NULL;
298 		udp_sk(sk)->encap_type = 0;
299 		rcu_assign_sk_user_data(sk, NULL);
300 		sock_put(sk);
301 	}
302 	release_sock(sk);
303 }
304 
305 static void gtp_encap_destroy(struct sock *sk)
306 {
307 	rtnl_lock();
308 	__gtp_encap_destroy(sk);
309 	rtnl_unlock();
310 }
311 
312 static void gtp_encap_disable_sock(struct sock *sk)
313 {
314 	if (!sk)
315 		return;
316 
317 	__gtp_encap_destroy(sk);
318 }
319 
320 static void gtp_encap_disable(struct gtp_dev *gtp)
321 {
322 	gtp_encap_disable_sock(gtp->sk0);
323 	gtp_encap_disable_sock(gtp->sk1u);
324 }
325 
326 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
327  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
328  */
329 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
330 {
331 	struct gtp_dev *gtp;
332 	int ret = 0;
333 
334 	gtp = rcu_dereference_sk_user_data(sk);
335 	if (!gtp)
336 		return 1;
337 
338 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
339 
340 	switch (udp_sk(sk)->encap_type) {
341 	case UDP_ENCAP_GTP0:
342 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
343 		ret = gtp0_udp_encap_recv(gtp, skb);
344 		break;
345 	case UDP_ENCAP_GTP1U:
346 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
347 		ret = gtp1u_udp_encap_recv(gtp, skb);
348 		break;
349 	default:
350 		ret = -1; /* Shouldn't happen. */
351 	}
352 
353 	switch (ret) {
354 	case 1:
355 		netdev_dbg(gtp->dev, "pass up to the process\n");
356 		break;
357 	case 0:
358 		break;
359 	case -1:
360 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
361 		kfree_skb(skb);
362 		ret = 0;
363 		break;
364 	}
365 
366 	return ret;
367 }
368 
369 static int gtp_dev_init(struct net_device *dev)
370 {
371 	struct gtp_dev *gtp = netdev_priv(dev);
372 
373 	gtp->dev = dev;
374 
375 	dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
376 	if (!dev->tstats)
377 		return -ENOMEM;
378 
379 	return 0;
380 }
381 
382 static void gtp_dev_uninit(struct net_device *dev)
383 {
384 	struct gtp_dev *gtp = netdev_priv(dev);
385 
386 	gtp_encap_disable(gtp);
387 	free_percpu(dev->tstats);
388 }
389 
390 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
391 					   const struct sock *sk,
392 					   __be32 daddr)
393 {
394 	memset(fl4, 0, sizeof(*fl4));
395 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
396 	fl4->daddr		= daddr;
397 	fl4->saddr		= inet_sk(sk)->inet_saddr;
398 	fl4->flowi4_tos		= RT_CONN_FLAGS(sk);
399 	fl4->flowi4_proto	= sk->sk_protocol;
400 
401 	return ip_route_output_key(sock_net(sk), fl4);
402 }
403 
404 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
405 {
406 	int payload_len = skb->len;
407 	struct gtp0_header *gtp0;
408 
409 	gtp0 = skb_push(skb, sizeof(*gtp0));
410 
411 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
412 	gtp0->type	= GTP_TPDU;
413 	gtp0->length	= htons(payload_len);
414 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
415 	gtp0->flow	= htons(pctx->u.v0.flow);
416 	gtp0->number	= 0xff;
417 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
418 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
419 }
420 
421 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
422 {
423 	int payload_len = skb->len;
424 	struct gtp1_header *gtp1;
425 
426 	gtp1 = skb_push(skb, sizeof(*gtp1));
427 
428 	/* Bits    8  7  6  5  4  3  2	1
429 	 *	  +--+--+--+--+--+--+--+--+
430 	 *	  |version |PT| 0| E| S|PN|
431 	 *	  +--+--+--+--+--+--+--+--+
432 	 *	    0  0  1  1	1  0  0  0
433 	 */
434 	gtp1->flags	= 0x30; /* v1, GTP-non-prime. */
435 	gtp1->type	= GTP_TPDU;
436 	gtp1->length	= htons(payload_len);
437 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
438 
439 	/* TODO: Suppport for extension header, sequence number and N-PDU.
440 	 *	 Update the length field if any of them is available.
441 	 */
442 }
443 
444 struct gtp_pktinfo {
445 	struct sock		*sk;
446 	struct iphdr		*iph;
447 	struct flowi4		fl4;
448 	struct rtable		*rt;
449 	struct pdp_ctx		*pctx;
450 	struct net_device	*dev;
451 	__be16			gtph_port;
452 };
453 
454 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
455 {
456 	switch (pktinfo->pctx->gtp_version) {
457 	case GTP_V0:
458 		pktinfo->gtph_port = htons(GTP0_PORT);
459 		gtp0_push_header(skb, pktinfo->pctx);
460 		break;
461 	case GTP_V1:
462 		pktinfo->gtph_port = htons(GTP1U_PORT);
463 		gtp1_push_header(skb, pktinfo->pctx);
464 		break;
465 	}
466 }
467 
468 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
469 					struct sock *sk, struct iphdr *iph,
470 					struct pdp_ctx *pctx, struct rtable *rt,
471 					struct flowi4 *fl4,
472 					struct net_device *dev)
473 {
474 	pktinfo->sk	= sk;
475 	pktinfo->iph	= iph;
476 	pktinfo->pctx	= pctx;
477 	pktinfo->rt	= rt;
478 	pktinfo->fl4	= *fl4;
479 	pktinfo->dev	= dev;
480 }
481 
482 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
483 			     struct gtp_pktinfo *pktinfo)
484 {
485 	struct gtp_dev *gtp = netdev_priv(dev);
486 	struct pdp_ctx *pctx;
487 	struct rtable *rt;
488 	struct flowi4 fl4;
489 	struct iphdr *iph;
490 	__be16 df;
491 	int mtu;
492 
493 	/* Read the IP destination address and resolve the PDP context.
494 	 * Prepend PDP header with TEI/TID from PDP ctx.
495 	 */
496 	iph = ip_hdr(skb);
497 	if (gtp->role == GTP_ROLE_SGSN)
498 		pctx = ipv4_pdp_find(gtp, iph->saddr);
499 	else
500 		pctx = ipv4_pdp_find(gtp, iph->daddr);
501 
502 	if (!pctx) {
503 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
504 			   &iph->daddr);
505 		return -ENOENT;
506 	}
507 	netdev_dbg(dev, "found PDP context %p\n", pctx);
508 
509 	rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
510 	if (IS_ERR(rt)) {
511 		netdev_dbg(dev, "no route to SSGN %pI4\n",
512 			   &pctx->peer_addr_ip4.s_addr);
513 		dev->stats.tx_carrier_errors++;
514 		goto err;
515 	}
516 
517 	if (rt->dst.dev == dev) {
518 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
519 			   &pctx->peer_addr_ip4.s_addr);
520 		dev->stats.collisions++;
521 		goto err_rt;
522 	}
523 
524 	skb_dst_drop(skb);
525 
526 	/* This is similar to tnl_update_pmtu(). */
527 	df = iph->frag_off;
528 	if (df) {
529 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
530 			sizeof(struct iphdr) - sizeof(struct udphdr);
531 		switch (pctx->gtp_version) {
532 		case GTP_V0:
533 			mtu -= sizeof(struct gtp0_header);
534 			break;
535 		case GTP_V1:
536 			mtu -= sizeof(struct gtp1_header);
537 			break;
538 		}
539 	} else {
540 		mtu = dst_mtu(&rt->dst);
541 	}
542 
543 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
544 
545 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
546 	    mtu < ntohs(iph->tot_len)) {
547 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
548 		memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
549 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
550 			      htonl(mtu));
551 		goto err_rt;
552 	}
553 
554 	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
555 	gtp_push_header(skb, pktinfo);
556 
557 	return 0;
558 err_rt:
559 	ip_rt_put(rt);
560 err:
561 	return -EBADMSG;
562 }
563 
564 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
565 {
566 	unsigned int proto = ntohs(skb->protocol);
567 	struct gtp_pktinfo pktinfo;
568 	int err;
569 
570 	/* Ensure there is sufficient headroom. */
571 	if (skb_cow_head(skb, dev->needed_headroom))
572 		goto tx_err;
573 
574 	skb_reset_inner_headers(skb);
575 
576 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
577 	rcu_read_lock();
578 	switch (proto) {
579 	case ETH_P_IP:
580 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
581 		break;
582 	default:
583 		err = -EOPNOTSUPP;
584 		break;
585 	}
586 	rcu_read_unlock();
587 
588 	if (err < 0)
589 		goto tx_err;
590 
591 	switch (proto) {
592 	case ETH_P_IP:
593 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
594 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
595 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
596 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
597 				    pktinfo.iph->tos,
598 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
599 				    0,
600 				    pktinfo.gtph_port, pktinfo.gtph_port,
601 				    true, false);
602 		break;
603 	}
604 
605 	return NETDEV_TX_OK;
606 tx_err:
607 	dev->stats.tx_errors++;
608 	dev_kfree_skb(skb);
609 	return NETDEV_TX_OK;
610 }
611 
612 static const struct net_device_ops gtp_netdev_ops = {
613 	.ndo_init		= gtp_dev_init,
614 	.ndo_uninit		= gtp_dev_uninit,
615 	.ndo_start_xmit		= gtp_dev_xmit,
616 	.ndo_get_stats64	= ip_tunnel_get_stats64,
617 };
618 
619 static void gtp_link_setup(struct net_device *dev)
620 {
621 	dev->netdev_ops		= &gtp_netdev_ops;
622 	dev->needs_free_netdev	= true;
623 
624 	dev->hard_header_len = 0;
625 	dev->addr_len = 0;
626 
627 	/* Zero header length. */
628 	dev->type = ARPHRD_NONE;
629 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
630 
631 	dev->priv_flags	|= IFF_NO_QUEUE;
632 	dev->features	|= NETIF_F_LLTX;
633 	netif_keep_dst(dev);
634 
635 	/* Assume largest header, ie. GTPv0. */
636 	dev->needed_headroom	= LL_MAX_HEADER +
637 				  sizeof(struct iphdr) +
638 				  sizeof(struct udphdr) +
639 				  sizeof(struct gtp0_header);
640 }
641 
642 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
643 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
644 
645 static void gtp_destructor(struct net_device *dev)
646 {
647 	struct gtp_dev *gtp = netdev_priv(dev);
648 
649 	kfree(gtp->addr_hash);
650 	kfree(gtp->tid_hash);
651 }
652 
653 static int gtp_newlink(struct net *src_net, struct net_device *dev,
654 		       struct nlattr *tb[], struct nlattr *data[],
655 		       struct netlink_ext_ack *extack)
656 {
657 	struct gtp_dev *gtp;
658 	struct gtp_net *gn;
659 	int hashsize, err;
660 
661 	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
662 		return -EINVAL;
663 
664 	gtp = netdev_priv(dev);
665 
666 	err = gtp_encap_enable(gtp, data);
667 	if (err < 0)
668 		return err;
669 
670 	if (!data[IFLA_GTP_PDP_HASHSIZE]) {
671 		hashsize = 1024;
672 	} else {
673 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
674 		if (!hashsize)
675 			hashsize = 1024;
676 	}
677 
678 	err = gtp_hashtable_new(gtp, hashsize);
679 	if (err < 0)
680 		goto out_encap;
681 
682 	err = register_netdevice(dev);
683 	if (err < 0) {
684 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
685 		goto out_hashtable;
686 	}
687 
688 	gn = net_generic(dev_net(dev), gtp_net_id);
689 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
690 	dev->priv_destructor = gtp_destructor;
691 
692 	netdev_dbg(dev, "registered new GTP interface\n");
693 
694 	return 0;
695 
696 out_hashtable:
697 	kfree(gtp->addr_hash);
698 	kfree(gtp->tid_hash);
699 out_encap:
700 	gtp_encap_disable(gtp);
701 	return err;
702 }
703 
704 static void gtp_dellink(struct net_device *dev, struct list_head *head)
705 {
706 	struct gtp_dev *gtp = netdev_priv(dev);
707 	struct pdp_ctx *pctx;
708 	int i;
709 
710 	for (i = 0; i < gtp->hash_size; i++)
711 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
712 			pdp_context_delete(pctx);
713 
714 	list_del_rcu(&gtp->list);
715 	unregister_netdevice_queue(dev, head);
716 }
717 
718 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
719 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
720 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
721 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
722 	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
723 };
724 
725 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
726 			struct netlink_ext_ack *extack)
727 {
728 	if (!data)
729 		return -EINVAL;
730 
731 	return 0;
732 }
733 
734 static size_t gtp_get_size(const struct net_device *dev)
735 {
736 	return nla_total_size(sizeof(__u32));	/* IFLA_GTP_PDP_HASHSIZE */
737 }
738 
739 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
740 {
741 	struct gtp_dev *gtp = netdev_priv(dev);
742 
743 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
744 		goto nla_put_failure;
745 
746 	return 0;
747 
748 nla_put_failure:
749 	return -EMSGSIZE;
750 }
751 
752 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
753 	.kind		= "gtp",
754 	.maxtype	= IFLA_GTP_MAX,
755 	.policy		= gtp_policy,
756 	.priv_size	= sizeof(struct gtp_dev),
757 	.setup		= gtp_link_setup,
758 	.validate	= gtp_validate,
759 	.newlink	= gtp_newlink,
760 	.dellink	= gtp_dellink,
761 	.get_size	= gtp_get_size,
762 	.fill_info	= gtp_fill_info,
763 };
764 
765 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
766 {
767 	int i;
768 
769 	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
770 				       GFP_KERNEL | __GFP_NOWARN);
771 	if (gtp->addr_hash == NULL)
772 		return -ENOMEM;
773 
774 	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
775 				      GFP_KERNEL | __GFP_NOWARN);
776 	if (gtp->tid_hash == NULL)
777 		goto err1;
778 
779 	gtp->hash_size = hsize;
780 
781 	for (i = 0; i < hsize; i++) {
782 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
783 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
784 	}
785 	return 0;
786 err1:
787 	kfree(gtp->addr_hash);
788 	return -ENOMEM;
789 }
790 
791 static struct sock *gtp_encap_enable_socket(int fd, int type,
792 					    struct gtp_dev *gtp)
793 {
794 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
795 	struct socket *sock;
796 	struct sock *sk;
797 	int err;
798 
799 	pr_debug("enable gtp on %d, %d\n", fd, type);
800 
801 	sock = sockfd_lookup(fd, &err);
802 	if (!sock) {
803 		pr_debug("gtp socket fd=%d not found\n", fd);
804 		return NULL;
805 	}
806 
807 	sk = sock->sk;
808 	if (sk->sk_protocol != IPPROTO_UDP ||
809 	    sk->sk_type != SOCK_DGRAM ||
810 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
811 		pr_debug("socket fd=%d not UDP\n", fd);
812 		sk = ERR_PTR(-EINVAL);
813 		goto out_sock;
814 	}
815 
816 	lock_sock(sk);
817 	if (sk->sk_user_data) {
818 		sk = ERR_PTR(-EBUSY);
819 		goto out_rel_sock;
820 	}
821 
822 	sock_hold(sk);
823 
824 	tuncfg.sk_user_data = gtp;
825 	tuncfg.encap_type = type;
826 	tuncfg.encap_rcv = gtp_encap_recv;
827 	tuncfg.encap_destroy = gtp_encap_destroy;
828 
829 	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
830 
831 out_rel_sock:
832 	release_sock(sock->sk);
833 out_sock:
834 	sockfd_put(sock);
835 	return sk;
836 }
837 
838 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
839 {
840 	struct sock *sk1u = NULL;
841 	struct sock *sk0 = NULL;
842 	unsigned int role = GTP_ROLE_GGSN;
843 
844 	if (data[IFLA_GTP_FD0]) {
845 		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
846 
847 		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
848 		if (IS_ERR(sk0))
849 			return PTR_ERR(sk0);
850 	}
851 
852 	if (data[IFLA_GTP_FD1]) {
853 		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
854 
855 		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
856 		if (IS_ERR(sk1u)) {
857 			gtp_encap_disable_sock(sk0);
858 			return PTR_ERR(sk1u);
859 		}
860 	}
861 
862 	if (data[IFLA_GTP_ROLE]) {
863 		role = nla_get_u32(data[IFLA_GTP_ROLE]);
864 		if (role > GTP_ROLE_SGSN) {
865 			gtp_encap_disable_sock(sk0);
866 			gtp_encap_disable_sock(sk1u);
867 			return -EINVAL;
868 		}
869 	}
870 
871 	gtp->sk0 = sk0;
872 	gtp->sk1u = sk1u;
873 	gtp->role = role;
874 
875 	return 0;
876 }
877 
878 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
879 {
880 	struct gtp_dev *gtp = NULL;
881 	struct net_device *dev;
882 	struct net *net;
883 
884 	/* Examine the link attributes and figure out which network namespace
885 	 * we are talking about.
886 	 */
887 	if (nla[GTPA_NET_NS_FD])
888 		net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
889 	else
890 		net = get_net(src_net);
891 
892 	if (IS_ERR(net))
893 		return NULL;
894 
895 	/* Check if there's an existing gtpX device to configure */
896 	dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
897 	if (dev && dev->netdev_ops == &gtp_netdev_ops)
898 		gtp = netdev_priv(dev);
899 
900 	put_net(net);
901 	return gtp;
902 }
903 
904 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
905 {
906 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
907 	pctx->af = AF_INET;
908 	pctx->peer_addr_ip4.s_addr =
909 		nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
910 	pctx->ms_addr_ip4.s_addr =
911 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
912 
913 	switch (pctx->gtp_version) {
914 	case GTP_V0:
915 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
916 		 * label needs to be the same for uplink and downlink packets,
917 		 * so let's annotate this.
918 		 */
919 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
920 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
921 		break;
922 	case GTP_V1:
923 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
924 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
925 		break;
926 	default:
927 		break;
928 	}
929 }
930 
931 static int gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
932 		       struct genl_info *info)
933 {
934 	struct pdp_ctx *pctx, *pctx_tid = NULL;
935 	struct net_device *dev = gtp->dev;
936 	u32 hash_ms, hash_tid = 0;
937 	unsigned int version;
938 	bool found = false;
939 	__be32 ms_addr;
940 
941 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
942 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
943 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
944 
945 	pctx = ipv4_pdp_find(gtp, ms_addr);
946 	if (pctx)
947 		found = true;
948 	if (version == GTP_V0)
949 		pctx_tid = gtp0_pdp_find(gtp,
950 					 nla_get_u64(info->attrs[GTPA_TID]));
951 	else if (version == GTP_V1)
952 		pctx_tid = gtp1_pdp_find(gtp,
953 					 nla_get_u32(info->attrs[GTPA_I_TEI]));
954 	if (pctx_tid)
955 		found = true;
956 
957 	if (found) {
958 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
959 			return -EEXIST;
960 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
961 			return -EOPNOTSUPP;
962 
963 		if (pctx && pctx_tid)
964 			return -EEXIST;
965 		if (!pctx)
966 			pctx = pctx_tid;
967 
968 		ipv4_pdp_fill(pctx, info);
969 
970 		if (pctx->gtp_version == GTP_V0)
971 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
972 				   pctx->u.v0.tid, pctx);
973 		else if (pctx->gtp_version == GTP_V1)
974 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
975 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
976 
977 		return 0;
978 
979 	}
980 
981 	pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
982 	if (pctx == NULL)
983 		return -ENOMEM;
984 
985 	sock_hold(sk);
986 	pctx->sk = sk;
987 	pctx->dev = gtp->dev;
988 	ipv4_pdp_fill(pctx, info);
989 	atomic_set(&pctx->tx_seq, 0);
990 
991 	switch (pctx->gtp_version) {
992 	case GTP_V0:
993 		/* TS 09.60: "The flow label identifies unambiguously a GTP
994 		 * flow.". We use the tid for this instead, I cannot find a
995 		 * situation in which this doesn't unambiguosly identify the
996 		 * PDP context.
997 		 */
998 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
999 		break;
1000 	case GTP_V1:
1001 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1002 		break;
1003 	}
1004 
1005 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
1006 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
1007 
1008 	switch (pctx->gtp_version) {
1009 	case GTP_V0:
1010 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1011 			   pctx->u.v0.tid, &pctx->peer_addr_ip4,
1012 			   &pctx->ms_addr_ip4, pctx);
1013 		break;
1014 	case GTP_V1:
1015 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1016 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1017 			   &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1018 		break;
1019 	}
1020 
1021 	return 0;
1022 }
1023 
1024 static void pdp_context_free(struct rcu_head *head)
1025 {
1026 	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1027 
1028 	sock_put(pctx->sk);
1029 	kfree(pctx);
1030 }
1031 
1032 static void pdp_context_delete(struct pdp_ctx *pctx)
1033 {
1034 	hlist_del_rcu(&pctx->hlist_tid);
1035 	hlist_del_rcu(&pctx->hlist_addr);
1036 	call_rcu(&pctx->rcu_head, pdp_context_free);
1037 }
1038 
1039 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1040 {
1041 	unsigned int version;
1042 	struct gtp_dev *gtp;
1043 	struct sock *sk;
1044 	int err;
1045 
1046 	if (!info->attrs[GTPA_VERSION] ||
1047 	    !info->attrs[GTPA_LINK] ||
1048 	    !info->attrs[GTPA_PEER_ADDRESS] ||
1049 	    !info->attrs[GTPA_MS_ADDRESS])
1050 		return -EINVAL;
1051 
1052 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1053 
1054 	switch (version) {
1055 	case GTP_V0:
1056 		if (!info->attrs[GTPA_TID] ||
1057 		    !info->attrs[GTPA_FLOW])
1058 			return -EINVAL;
1059 		break;
1060 	case GTP_V1:
1061 		if (!info->attrs[GTPA_I_TEI] ||
1062 		    !info->attrs[GTPA_O_TEI])
1063 			return -EINVAL;
1064 		break;
1065 
1066 	default:
1067 		return -EINVAL;
1068 	}
1069 
1070 	rtnl_lock();
1071 	rcu_read_lock();
1072 
1073 	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1074 	if (!gtp) {
1075 		err = -ENODEV;
1076 		goto out_unlock;
1077 	}
1078 
1079 	if (version == GTP_V0)
1080 		sk = gtp->sk0;
1081 	else if (version == GTP_V1)
1082 		sk = gtp->sk1u;
1083 	else
1084 		sk = NULL;
1085 
1086 	if (!sk) {
1087 		err = -ENODEV;
1088 		goto out_unlock;
1089 	}
1090 
1091 	err = gtp_pdp_add(gtp, sk, info);
1092 
1093 out_unlock:
1094 	rcu_read_unlock();
1095 	rtnl_unlock();
1096 	return err;
1097 }
1098 
1099 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1100 					    struct nlattr *nla[])
1101 {
1102 	struct gtp_dev *gtp;
1103 
1104 	gtp = gtp_find_dev(net, nla);
1105 	if (!gtp)
1106 		return ERR_PTR(-ENODEV);
1107 
1108 	if (nla[GTPA_MS_ADDRESS]) {
1109 		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1110 
1111 		return ipv4_pdp_find(gtp, ip);
1112 	} else if (nla[GTPA_VERSION]) {
1113 		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1114 
1115 		if (gtp_version == GTP_V0 && nla[GTPA_TID])
1116 			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1117 		else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1118 			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1119 	}
1120 
1121 	return ERR_PTR(-EINVAL);
1122 }
1123 
1124 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1125 {
1126 	struct pdp_ctx *pctx;
1127 
1128 	if (nla[GTPA_LINK])
1129 		pctx = gtp_find_pdp_by_link(net, nla);
1130 	else
1131 		pctx = ERR_PTR(-EINVAL);
1132 
1133 	if (!pctx)
1134 		pctx = ERR_PTR(-ENOENT);
1135 
1136 	return pctx;
1137 }
1138 
1139 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1140 {
1141 	struct pdp_ctx *pctx;
1142 	int err = 0;
1143 
1144 	if (!info->attrs[GTPA_VERSION])
1145 		return -EINVAL;
1146 
1147 	rcu_read_lock();
1148 
1149 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1150 	if (IS_ERR(pctx)) {
1151 		err = PTR_ERR(pctx);
1152 		goto out_unlock;
1153 	}
1154 
1155 	if (pctx->gtp_version == GTP_V0)
1156 		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1157 			   pctx->u.v0.tid, pctx);
1158 	else if (pctx->gtp_version == GTP_V1)
1159 		netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1160 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1161 
1162 	pdp_context_delete(pctx);
1163 
1164 out_unlock:
1165 	rcu_read_unlock();
1166 	return err;
1167 }
1168 
1169 static struct genl_family gtp_genl_family;
1170 
1171 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1172 			      int flags, u32 type, struct pdp_ctx *pctx)
1173 {
1174 	void *genlh;
1175 
1176 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
1177 			    type);
1178 	if (genlh == NULL)
1179 		goto nlmsg_failure;
1180 
1181 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1182 	    nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1183 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1184 		goto nla_put_failure;
1185 
1186 	switch (pctx->gtp_version) {
1187 	case GTP_V0:
1188 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1189 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1190 			goto nla_put_failure;
1191 		break;
1192 	case GTP_V1:
1193 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1194 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1195 			goto nla_put_failure;
1196 		break;
1197 	}
1198 	genlmsg_end(skb, genlh);
1199 	return 0;
1200 
1201 nlmsg_failure:
1202 nla_put_failure:
1203 	genlmsg_cancel(skb, genlh);
1204 	return -EMSGSIZE;
1205 }
1206 
1207 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1208 {
1209 	struct pdp_ctx *pctx = NULL;
1210 	struct sk_buff *skb2;
1211 	int err;
1212 
1213 	if (!info->attrs[GTPA_VERSION])
1214 		return -EINVAL;
1215 
1216 	rcu_read_lock();
1217 
1218 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1219 	if (IS_ERR(pctx)) {
1220 		err = PTR_ERR(pctx);
1221 		goto err_unlock;
1222 	}
1223 
1224 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1225 	if (skb2 == NULL) {
1226 		err = -ENOMEM;
1227 		goto err_unlock;
1228 	}
1229 
1230 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1231 				 0, info->nlhdr->nlmsg_type, pctx);
1232 	if (err < 0)
1233 		goto err_unlock_free;
1234 
1235 	rcu_read_unlock();
1236 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1237 
1238 err_unlock_free:
1239 	kfree_skb(skb2);
1240 err_unlock:
1241 	rcu_read_unlock();
1242 	return err;
1243 }
1244 
1245 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1246 				struct netlink_callback *cb)
1247 {
1248 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1249 	int i, j, bucket = cb->args[0], skip = cb->args[1];
1250 	struct net *net = sock_net(skb->sk);
1251 	struct pdp_ctx *pctx;
1252 	struct gtp_net *gn;
1253 
1254 	gn = net_generic(net, gtp_net_id);
1255 
1256 	if (cb->args[4])
1257 		return 0;
1258 
1259 	rcu_read_lock();
1260 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1261 		if (last_gtp && last_gtp != gtp)
1262 			continue;
1263 		else
1264 			last_gtp = NULL;
1265 
1266 		for (i = bucket; i < gtp->hash_size; i++) {
1267 			j = 0;
1268 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
1269 						 hlist_tid) {
1270 				if (j >= skip &&
1271 				    gtp_genl_fill_info(skb,
1272 					    NETLINK_CB(cb->skb).portid,
1273 					    cb->nlh->nlmsg_seq,
1274 					    NLM_F_MULTI,
1275 					    cb->nlh->nlmsg_type, pctx)) {
1276 					cb->args[0] = i;
1277 					cb->args[1] = j;
1278 					cb->args[2] = (unsigned long)gtp;
1279 					goto out;
1280 				}
1281 				j++;
1282 			}
1283 			skip = 0;
1284 		}
1285 		bucket = 0;
1286 	}
1287 	cb->args[4] = 1;
1288 out:
1289 	rcu_read_unlock();
1290 	return skb->len;
1291 }
1292 
1293 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1294 	[GTPA_LINK]		= { .type = NLA_U32, },
1295 	[GTPA_VERSION]		= { .type = NLA_U32, },
1296 	[GTPA_TID]		= { .type = NLA_U64, },
1297 	[GTPA_PEER_ADDRESS]	= { .type = NLA_U32, },
1298 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1299 	[GTPA_FLOW]		= { .type = NLA_U16, },
1300 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1301 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1302 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1303 };
1304 
1305 static const struct genl_ops gtp_genl_ops[] = {
1306 	{
1307 		.cmd = GTP_CMD_NEWPDP,
1308 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1309 		.doit = gtp_genl_new_pdp,
1310 		.flags = GENL_ADMIN_PERM,
1311 	},
1312 	{
1313 		.cmd = GTP_CMD_DELPDP,
1314 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1315 		.doit = gtp_genl_del_pdp,
1316 		.flags = GENL_ADMIN_PERM,
1317 	},
1318 	{
1319 		.cmd = GTP_CMD_GETPDP,
1320 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1321 		.doit = gtp_genl_get_pdp,
1322 		.dumpit = gtp_genl_dump_pdp,
1323 		.flags = GENL_ADMIN_PERM,
1324 	},
1325 };
1326 
1327 static struct genl_family gtp_genl_family __ro_after_init = {
1328 	.name		= "gtp",
1329 	.version	= 0,
1330 	.hdrsize	= 0,
1331 	.maxattr	= GTPA_MAX,
1332 	.policy = gtp_genl_policy,
1333 	.netnsok	= true,
1334 	.module		= THIS_MODULE,
1335 	.ops		= gtp_genl_ops,
1336 	.n_ops		= ARRAY_SIZE(gtp_genl_ops),
1337 };
1338 
1339 static int __net_init gtp_net_init(struct net *net)
1340 {
1341 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1342 
1343 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1344 	return 0;
1345 }
1346 
1347 static void __net_exit gtp_net_exit(struct net *net)
1348 {
1349 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1350 	struct gtp_dev *gtp;
1351 	LIST_HEAD(list);
1352 
1353 	rtnl_lock();
1354 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1355 		gtp_dellink(gtp->dev, &list);
1356 
1357 	unregister_netdevice_many(&list);
1358 	rtnl_unlock();
1359 }
1360 
1361 static struct pernet_operations gtp_net_ops = {
1362 	.init	= gtp_net_init,
1363 	.exit	= gtp_net_exit,
1364 	.id	= &gtp_net_id,
1365 	.size	= sizeof(struct gtp_net),
1366 };
1367 
1368 static int __init gtp_init(void)
1369 {
1370 	int err;
1371 
1372 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1373 
1374 	err = rtnl_link_register(&gtp_link_ops);
1375 	if (err < 0)
1376 		goto error_out;
1377 
1378 	err = genl_register_family(&gtp_genl_family);
1379 	if (err < 0)
1380 		goto unreg_rtnl_link;
1381 
1382 	err = register_pernet_subsys(&gtp_net_ops);
1383 	if (err < 0)
1384 		goto unreg_genl_family;
1385 
1386 	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1387 		sizeof(struct pdp_ctx));
1388 	return 0;
1389 
1390 unreg_genl_family:
1391 	genl_unregister_family(&gtp_genl_family);
1392 unreg_rtnl_link:
1393 	rtnl_link_unregister(&gtp_link_ops);
1394 error_out:
1395 	pr_err("error loading GTP module loaded\n");
1396 	return err;
1397 }
1398 late_initcall(gtp_init);
1399 
1400 static void __exit gtp_fini(void)
1401 {
1402 	genl_unregister_family(&gtp_genl_family);
1403 	rtnl_link_unregister(&gtp_link_ops);
1404 	unregister_pernet_subsys(&gtp_net_ops);
1405 
1406 	pr_info("GTP module unloaded\n");
1407 }
1408 module_exit(gtp_fini);
1409 
1410 MODULE_LICENSE("GPL");
1411 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1412 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1413 MODULE_ALIAS_RTNL_LINK("gtp");
1414 MODULE_ALIAS_GENL_FAMILY("gtp");
1415