xref: /openbmc/linux/drivers/net/gtp.c (revision f7af616c)
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 	if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
186 		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
187 		return 1;
188 	}
189 
190 	/* Get rid of the GTP + UDP headers. */
191 	if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
192 			 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
193 		pctx->dev->stats.rx_length_errors++;
194 		goto err;
195 	}
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 	dev_sw_netstats_rx_add(pctx->dev, skb->len);
208 
209 	netif_rx(skb);
210 	return 0;
211 
212 err:
213 	pctx->dev->stats.rx_dropped++;
214 	return -1;
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: Support 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 	/* This is similar to tnl_update_pmtu(). */
525 	df = iph->frag_off;
526 	if (df) {
527 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
528 			sizeof(struct iphdr) - sizeof(struct udphdr);
529 		switch (pctx->gtp_version) {
530 		case GTP_V0:
531 			mtu -= sizeof(struct gtp0_header);
532 			break;
533 		case GTP_V1:
534 			mtu -= sizeof(struct gtp1_header);
535 			break;
536 		}
537 	} else {
538 		mtu = dst_mtu(&rt->dst);
539 	}
540 
541 	rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
542 
543 	if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
544 	    mtu < ntohs(iph->tot_len)) {
545 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
546 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
547 			      htonl(mtu));
548 		goto err_rt;
549 	}
550 
551 	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
552 	gtp_push_header(skb, pktinfo);
553 
554 	return 0;
555 err_rt:
556 	ip_rt_put(rt);
557 err:
558 	return -EBADMSG;
559 }
560 
561 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
562 {
563 	unsigned int proto = ntohs(skb->protocol);
564 	struct gtp_pktinfo pktinfo;
565 	int err;
566 
567 	/* Ensure there is sufficient headroom. */
568 	if (skb_cow_head(skb, dev->needed_headroom))
569 		goto tx_err;
570 
571 	skb_reset_inner_headers(skb);
572 
573 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
574 	rcu_read_lock();
575 	switch (proto) {
576 	case ETH_P_IP:
577 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
578 		break;
579 	default:
580 		err = -EOPNOTSUPP;
581 		break;
582 	}
583 	rcu_read_unlock();
584 
585 	if (err < 0)
586 		goto tx_err;
587 
588 	switch (proto) {
589 	case ETH_P_IP:
590 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
591 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
592 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
593 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
594 				    pktinfo.iph->tos,
595 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
596 				    0,
597 				    pktinfo.gtph_port, pktinfo.gtph_port,
598 				    !net_eq(sock_net(pktinfo.pctx->sk),
599 					    dev_net(dev)),
600 				    false);
601 		break;
602 	}
603 
604 	return NETDEV_TX_OK;
605 tx_err:
606 	dev->stats.tx_errors++;
607 	dev_kfree_skb(skb);
608 	return NETDEV_TX_OK;
609 }
610 
611 static const struct net_device_ops gtp_netdev_ops = {
612 	.ndo_init		= gtp_dev_init,
613 	.ndo_uninit		= gtp_dev_uninit,
614 	.ndo_start_xmit		= gtp_dev_xmit,
615 	.ndo_get_stats64	= dev_get_tstats64,
616 };
617 
618 static const struct device_type gtp_type = {
619 	.name = "gtp",
620 };
621 
622 static void gtp_link_setup(struct net_device *dev)
623 {
624 	unsigned int max_gtp_header_len = sizeof(struct iphdr) +
625 					  sizeof(struct udphdr) +
626 					  sizeof(struct gtp0_header);
627 
628 	dev->netdev_ops		= &gtp_netdev_ops;
629 	dev->needs_free_netdev	= true;
630 	SET_NETDEV_DEVTYPE(dev, &gtp_type);
631 
632 	dev->hard_header_len = 0;
633 	dev->addr_len = 0;
634 	dev->mtu = ETH_DATA_LEN - max_gtp_header_len;
635 
636 	/* Zero header length. */
637 	dev->type = ARPHRD_NONE;
638 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
639 
640 	dev->priv_flags	|= IFF_NO_QUEUE;
641 	dev->features	|= NETIF_F_LLTX;
642 	netif_keep_dst(dev);
643 
644 	dev->needed_headroom	= LL_MAX_HEADER + max_gtp_header_len;
645 }
646 
647 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
648 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
649 
650 static void gtp_destructor(struct net_device *dev)
651 {
652 	struct gtp_dev *gtp = netdev_priv(dev);
653 
654 	kfree(gtp->addr_hash);
655 	kfree(gtp->tid_hash);
656 }
657 
658 static int gtp_newlink(struct net *src_net, struct net_device *dev,
659 		       struct nlattr *tb[], struct nlattr *data[],
660 		       struct netlink_ext_ack *extack)
661 {
662 	struct gtp_dev *gtp;
663 	struct gtp_net *gn;
664 	int hashsize, err;
665 
666 	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
667 		return -EINVAL;
668 
669 	gtp = netdev_priv(dev);
670 
671 	if (!data[IFLA_GTP_PDP_HASHSIZE]) {
672 		hashsize = 1024;
673 	} else {
674 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
675 		if (!hashsize)
676 			hashsize = 1024;
677 	}
678 
679 	err = gtp_hashtable_new(gtp, hashsize);
680 	if (err < 0)
681 		return err;
682 
683 	err = gtp_encap_enable(gtp, data);
684 	if (err < 0)
685 		goto out_hashtable;
686 
687 	err = register_netdevice(dev);
688 	if (err < 0) {
689 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
690 		goto out_encap;
691 	}
692 
693 	gn = net_generic(dev_net(dev), gtp_net_id);
694 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
695 	dev->priv_destructor = gtp_destructor;
696 
697 	netdev_dbg(dev, "registered new GTP interface\n");
698 
699 	return 0;
700 
701 out_encap:
702 	gtp_encap_disable(gtp);
703 out_hashtable:
704 	kfree(gtp->addr_hash);
705 	kfree(gtp->tid_hash);
706 	return err;
707 }
708 
709 static void gtp_dellink(struct net_device *dev, struct list_head *head)
710 {
711 	struct gtp_dev *gtp = netdev_priv(dev);
712 	struct pdp_ctx *pctx;
713 	int i;
714 
715 	for (i = 0; i < gtp->hash_size; i++)
716 		hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i], hlist_tid)
717 			pdp_context_delete(pctx);
718 
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 	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
728 };
729 
730 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
731 			struct netlink_ext_ack *extack)
732 {
733 	if (!data)
734 		return -EINVAL;
735 
736 	return 0;
737 }
738 
739 static size_t gtp_get_size(const struct net_device *dev)
740 {
741 	return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
742 		nla_total_size(sizeof(__u32)); /* IFLA_GTP_ROLE */
743 }
744 
745 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
746 {
747 	struct gtp_dev *gtp = netdev_priv(dev);
748 
749 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
750 		goto nla_put_failure;
751 	if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
752 		goto nla_put_failure;
753 
754 	return 0;
755 
756 nla_put_failure:
757 	return -EMSGSIZE;
758 }
759 
760 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
761 	.kind		= "gtp",
762 	.maxtype	= IFLA_GTP_MAX,
763 	.policy		= gtp_policy,
764 	.priv_size	= sizeof(struct gtp_dev),
765 	.setup		= gtp_link_setup,
766 	.validate	= gtp_validate,
767 	.newlink	= gtp_newlink,
768 	.dellink	= gtp_dellink,
769 	.get_size	= gtp_get_size,
770 	.fill_info	= gtp_fill_info,
771 };
772 
773 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
774 {
775 	int i;
776 
777 	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
778 				       GFP_KERNEL | __GFP_NOWARN);
779 	if (gtp->addr_hash == NULL)
780 		return -ENOMEM;
781 
782 	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
783 				      GFP_KERNEL | __GFP_NOWARN);
784 	if (gtp->tid_hash == NULL)
785 		goto err1;
786 
787 	gtp->hash_size = hsize;
788 
789 	for (i = 0; i < hsize; i++) {
790 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
791 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
792 	}
793 	return 0;
794 err1:
795 	kfree(gtp->addr_hash);
796 	return -ENOMEM;
797 }
798 
799 static struct sock *gtp_encap_enable_socket(int fd, int type,
800 					    struct gtp_dev *gtp)
801 {
802 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
803 	struct socket *sock;
804 	struct sock *sk;
805 	int err;
806 
807 	pr_debug("enable gtp on %d, %d\n", fd, type);
808 
809 	sock = sockfd_lookup(fd, &err);
810 	if (!sock) {
811 		pr_debug("gtp socket fd=%d not found\n", fd);
812 		return NULL;
813 	}
814 
815 	sk = sock->sk;
816 	if (sk->sk_protocol != IPPROTO_UDP ||
817 	    sk->sk_type != SOCK_DGRAM ||
818 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
819 		pr_debug("socket fd=%d not UDP\n", fd);
820 		sk = ERR_PTR(-EINVAL);
821 		goto out_sock;
822 	}
823 
824 	lock_sock(sk);
825 	if (sk->sk_user_data) {
826 		sk = ERR_PTR(-EBUSY);
827 		goto out_rel_sock;
828 	}
829 
830 	sock_hold(sk);
831 
832 	tuncfg.sk_user_data = gtp;
833 	tuncfg.encap_type = type;
834 	tuncfg.encap_rcv = gtp_encap_recv;
835 	tuncfg.encap_destroy = gtp_encap_destroy;
836 
837 	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
838 
839 out_rel_sock:
840 	release_sock(sock->sk);
841 out_sock:
842 	sockfd_put(sock);
843 	return sk;
844 }
845 
846 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
847 {
848 	struct sock *sk1u = NULL;
849 	struct sock *sk0 = NULL;
850 	unsigned int role = GTP_ROLE_GGSN;
851 
852 	if (data[IFLA_GTP_FD0]) {
853 		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
854 
855 		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
856 		if (IS_ERR(sk0))
857 			return PTR_ERR(sk0);
858 	}
859 
860 	if (data[IFLA_GTP_FD1]) {
861 		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
862 
863 		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
864 		if (IS_ERR(sk1u)) {
865 			gtp_encap_disable_sock(sk0);
866 			return PTR_ERR(sk1u);
867 		}
868 	}
869 
870 	if (data[IFLA_GTP_ROLE]) {
871 		role = nla_get_u32(data[IFLA_GTP_ROLE]);
872 		if (role > GTP_ROLE_SGSN) {
873 			gtp_encap_disable_sock(sk0);
874 			gtp_encap_disable_sock(sk1u);
875 			return -EINVAL;
876 		}
877 	}
878 
879 	gtp->sk0 = sk0;
880 	gtp->sk1u = sk1u;
881 	gtp->role = role;
882 
883 	return 0;
884 }
885 
886 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
887 {
888 	struct gtp_dev *gtp = NULL;
889 	struct net_device *dev;
890 	struct net *net;
891 
892 	/* Examine the link attributes and figure out which network namespace
893 	 * we are talking about.
894 	 */
895 	if (nla[GTPA_NET_NS_FD])
896 		net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
897 	else
898 		net = get_net(src_net);
899 
900 	if (IS_ERR(net))
901 		return NULL;
902 
903 	/* Check if there's an existing gtpX device to configure */
904 	dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
905 	if (dev && dev->netdev_ops == &gtp_netdev_ops)
906 		gtp = netdev_priv(dev);
907 
908 	put_net(net);
909 	return gtp;
910 }
911 
912 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
913 {
914 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
915 	pctx->af = AF_INET;
916 	pctx->peer_addr_ip4.s_addr =
917 		nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
918 	pctx->ms_addr_ip4.s_addr =
919 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
920 
921 	switch (pctx->gtp_version) {
922 	case GTP_V0:
923 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
924 		 * label needs to be the same for uplink and downlink packets,
925 		 * so let's annotate this.
926 		 */
927 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
928 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
929 		break;
930 	case GTP_V1:
931 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
932 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
933 		break;
934 	default:
935 		break;
936 	}
937 }
938 
939 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
940 				   struct genl_info *info)
941 {
942 	struct pdp_ctx *pctx, *pctx_tid = NULL;
943 	struct net_device *dev = gtp->dev;
944 	u32 hash_ms, hash_tid = 0;
945 	unsigned int version;
946 	bool found = false;
947 	__be32 ms_addr;
948 
949 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
950 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
951 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
952 
953 	pctx = ipv4_pdp_find(gtp, ms_addr);
954 	if (pctx)
955 		found = true;
956 	if (version == GTP_V0)
957 		pctx_tid = gtp0_pdp_find(gtp,
958 					 nla_get_u64(info->attrs[GTPA_TID]));
959 	else if (version == GTP_V1)
960 		pctx_tid = gtp1_pdp_find(gtp,
961 					 nla_get_u32(info->attrs[GTPA_I_TEI]));
962 	if (pctx_tid)
963 		found = true;
964 
965 	if (found) {
966 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
967 			return ERR_PTR(-EEXIST);
968 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
969 			return ERR_PTR(-EOPNOTSUPP);
970 
971 		if (pctx && pctx_tid)
972 			return ERR_PTR(-EEXIST);
973 		if (!pctx)
974 			pctx = pctx_tid;
975 
976 		ipv4_pdp_fill(pctx, info);
977 
978 		if (pctx->gtp_version == GTP_V0)
979 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
980 				   pctx->u.v0.tid, pctx);
981 		else if (pctx->gtp_version == GTP_V1)
982 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
983 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
984 
985 		return pctx;
986 
987 	}
988 
989 	pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
990 	if (pctx == NULL)
991 		return ERR_PTR(-ENOMEM);
992 
993 	sock_hold(sk);
994 	pctx->sk = sk;
995 	pctx->dev = gtp->dev;
996 	ipv4_pdp_fill(pctx, info);
997 	atomic_set(&pctx->tx_seq, 0);
998 
999 	switch (pctx->gtp_version) {
1000 	case GTP_V0:
1001 		/* TS 09.60: "The flow label identifies unambiguously a GTP
1002 		 * flow.". We use the tid for this instead, I cannot find a
1003 		 * situation in which this doesn't unambiguosly identify the
1004 		 * PDP context.
1005 		 */
1006 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1007 		break;
1008 	case GTP_V1:
1009 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1010 		break;
1011 	}
1012 
1013 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
1014 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
1015 
1016 	switch (pctx->gtp_version) {
1017 	case GTP_V0:
1018 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1019 			   pctx->u.v0.tid, &pctx->peer_addr_ip4,
1020 			   &pctx->ms_addr_ip4, pctx);
1021 		break;
1022 	case GTP_V1:
1023 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1024 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1025 			   &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1026 		break;
1027 	}
1028 
1029 	return pctx;
1030 }
1031 
1032 static void pdp_context_free(struct rcu_head *head)
1033 {
1034 	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1035 
1036 	sock_put(pctx->sk);
1037 	kfree(pctx);
1038 }
1039 
1040 static void pdp_context_delete(struct pdp_ctx *pctx)
1041 {
1042 	hlist_del_rcu(&pctx->hlist_tid);
1043 	hlist_del_rcu(&pctx->hlist_addr);
1044 	call_rcu(&pctx->rcu_head, pdp_context_free);
1045 }
1046 
1047 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1048 
1049 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1050 {
1051 	unsigned int version;
1052 	struct pdp_ctx *pctx;
1053 	struct gtp_dev *gtp;
1054 	struct sock *sk;
1055 	int err;
1056 
1057 	if (!info->attrs[GTPA_VERSION] ||
1058 	    !info->attrs[GTPA_LINK] ||
1059 	    !info->attrs[GTPA_PEER_ADDRESS] ||
1060 	    !info->attrs[GTPA_MS_ADDRESS])
1061 		return -EINVAL;
1062 
1063 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1064 
1065 	switch (version) {
1066 	case GTP_V0:
1067 		if (!info->attrs[GTPA_TID] ||
1068 		    !info->attrs[GTPA_FLOW])
1069 			return -EINVAL;
1070 		break;
1071 	case GTP_V1:
1072 		if (!info->attrs[GTPA_I_TEI] ||
1073 		    !info->attrs[GTPA_O_TEI])
1074 			return -EINVAL;
1075 		break;
1076 
1077 	default:
1078 		return -EINVAL;
1079 	}
1080 
1081 	rtnl_lock();
1082 
1083 	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1084 	if (!gtp) {
1085 		err = -ENODEV;
1086 		goto out_unlock;
1087 	}
1088 
1089 	if (version == GTP_V0)
1090 		sk = gtp->sk0;
1091 	else if (version == GTP_V1)
1092 		sk = gtp->sk1u;
1093 	else
1094 		sk = NULL;
1095 
1096 	if (!sk) {
1097 		err = -ENODEV;
1098 		goto out_unlock;
1099 	}
1100 
1101 	pctx = gtp_pdp_add(gtp, sk, info);
1102 	if (IS_ERR(pctx)) {
1103 		err = PTR_ERR(pctx);
1104 	} else {
1105 		gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1106 		err = 0;
1107 	}
1108 
1109 out_unlock:
1110 	rtnl_unlock();
1111 	return err;
1112 }
1113 
1114 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1115 					    struct nlattr *nla[])
1116 {
1117 	struct gtp_dev *gtp;
1118 
1119 	gtp = gtp_find_dev(net, nla);
1120 	if (!gtp)
1121 		return ERR_PTR(-ENODEV);
1122 
1123 	if (nla[GTPA_MS_ADDRESS]) {
1124 		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1125 
1126 		return ipv4_pdp_find(gtp, ip);
1127 	} else if (nla[GTPA_VERSION]) {
1128 		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1129 
1130 		if (gtp_version == GTP_V0 && nla[GTPA_TID])
1131 			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1132 		else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1133 			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1134 	}
1135 
1136 	return ERR_PTR(-EINVAL);
1137 }
1138 
1139 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1140 {
1141 	struct pdp_ctx *pctx;
1142 
1143 	if (nla[GTPA_LINK])
1144 		pctx = gtp_find_pdp_by_link(net, nla);
1145 	else
1146 		pctx = ERR_PTR(-EINVAL);
1147 
1148 	if (!pctx)
1149 		pctx = ERR_PTR(-ENOENT);
1150 
1151 	return pctx;
1152 }
1153 
1154 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1155 {
1156 	struct pdp_ctx *pctx;
1157 	int err = 0;
1158 
1159 	if (!info->attrs[GTPA_VERSION])
1160 		return -EINVAL;
1161 
1162 	rcu_read_lock();
1163 
1164 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1165 	if (IS_ERR(pctx)) {
1166 		err = PTR_ERR(pctx);
1167 		goto out_unlock;
1168 	}
1169 
1170 	if (pctx->gtp_version == GTP_V0)
1171 		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1172 			   pctx->u.v0.tid, pctx);
1173 	else if (pctx->gtp_version == GTP_V1)
1174 		netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1175 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1176 
1177 	gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1178 	pdp_context_delete(pctx);
1179 
1180 out_unlock:
1181 	rcu_read_unlock();
1182 	return err;
1183 }
1184 
1185 static struct genl_family gtp_genl_family;
1186 
1187 enum gtp_multicast_groups {
1188 	GTP_GENL_MCGRP,
1189 };
1190 
1191 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
1192 	[GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
1193 };
1194 
1195 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1196 			      int flags, u32 type, struct pdp_ctx *pctx)
1197 {
1198 	void *genlh;
1199 
1200 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
1201 			    type);
1202 	if (genlh == NULL)
1203 		goto nlmsg_failure;
1204 
1205 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1206 	    nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1207 	    nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1208 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1209 		goto nla_put_failure;
1210 
1211 	switch (pctx->gtp_version) {
1212 	case GTP_V0:
1213 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1214 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1215 			goto nla_put_failure;
1216 		break;
1217 	case GTP_V1:
1218 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1219 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1220 			goto nla_put_failure;
1221 		break;
1222 	}
1223 	genlmsg_end(skb, genlh);
1224 	return 0;
1225 
1226 nlmsg_failure:
1227 nla_put_failure:
1228 	genlmsg_cancel(skb, genlh);
1229 	return -EMSGSIZE;
1230 }
1231 
1232 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1233 {
1234 	struct sk_buff *msg;
1235 	int ret;
1236 
1237 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1238 	if (!msg)
1239 		return -ENOMEM;
1240 
1241 	ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1242 	if (ret < 0) {
1243 		nlmsg_free(msg);
1244 		return ret;
1245 	}
1246 
1247 	ret = genlmsg_multicast_netns(&gtp_genl_family, dev_net(pctx->dev), msg,
1248 				      0, GTP_GENL_MCGRP, GFP_ATOMIC);
1249 	return ret;
1250 }
1251 
1252 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1253 {
1254 	struct pdp_ctx *pctx = NULL;
1255 	struct sk_buff *skb2;
1256 	int err;
1257 
1258 	if (!info->attrs[GTPA_VERSION])
1259 		return -EINVAL;
1260 
1261 	rcu_read_lock();
1262 
1263 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1264 	if (IS_ERR(pctx)) {
1265 		err = PTR_ERR(pctx);
1266 		goto err_unlock;
1267 	}
1268 
1269 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1270 	if (skb2 == NULL) {
1271 		err = -ENOMEM;
1272 		goto err_unlock;
1273 	}
1274 
1275 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1276 				 0, info->nlhdr->nlmsg_type, pctx);
1277 	if (err < 0)
1278 		goto err_unlock_free;
1279 
1280 	rcu_read_unlock();
1281 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1282 
1283 err_unlock_free:
1284 	kfree_skb(skb2);
1285 err_unlock:
1286 	rcu_read_unlock();
1287 	return err;
1288 }
1289 
1290 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1291 				struct netlink_callback *cb)
1292 {
1293 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1294 	int i, j, bucket = cb->args[0], skip = cb->args[1];
1295 	struct net *net = sock_net(skb->sk);
1296 	struct pdp_ctx *pctx;
1297 	struct gtp_net *gn;
1298 
1299 	gn = net_generic(net, gtp_net_id);
1300 
1301 	if (cb->args[4])
1302 		return 0;
1303 
1304 	rcu_read_lock();
1305 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1306 		if (last_gtp && last_gtp != gtp)
1307 			continue;
1308 		else
1309 			last_gtp = NULL;
1310 
1311 		for (i = bucket; i < gtp->hash_size; i++) {
1312 			j = 0;
1313 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
1314 						 hlist_tid) {
1315 				if (j >= skip &&
1316 				    gtp_genl_fill_info(skb,
1317 					    NETLINK_CB(cb->skb).portid,
1318 					    cb->nlh->nlmsg_seq,
1319 					    NLM_F_MULTI,
1320 					    cb->nlh->nlmsg_type, pctx)) {
1321 					cb->args[0] = i;
1322 					cb->args[1] = j;
1323 					cb->args[2] = (unsigned long)gtp;
1324 					goto out;
1325 				}
1326 				j++;
1327 			}
1328 			skip = 0;
1329 		}
1330 		bucket = 0;
1331 	}
1332 	cb->args[4] = 1;
1333 out:
1334 	rcu_read_unlock();
1335 	return skb->len;
1336 }
1337 
1338 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1339 	[GTPA_LINK]		= { .type = NLA_U32, },
1340 	[GTPA_VERSION]		= { .type = NLA_U32, },
1341 	[GTPA_TID]		= { .type = NLA_U64, },
1342 	[GTPA_PEER_ADDRESS]	= { .type = NLA_U32, },
1343 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1344 	[GTPA_FLOW]		= { .type = NLA_U16, },
1345 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1346 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1347 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1348 };
1349 
1350 static const struct genl_small_ops gtp_genl_ops[] = {
1351 	{
1352 		.cmd = GTP_CMD_NEWPDP,
1353 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1354 		.doit = gtp_genl_new_pdp,
1355 		.flags = GENL_ADMIN_PERM,
1356 	},
1357 	{
1358 		.cmd = GTP_CMD_DELPDP,
1359 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1360 		.doit = gtp_genl_del_pdp,
1361 		.flags = GENL_ADMIN_PERM,
1362 	},
1363 	{
1364 		.cmd = GTP_CMD_GETPDP,
1365 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1366 		.doit = gtp_genl_get_pdp,
1367 		.dumpit = gtp_genl_dump_pdp,
1368 		.flags = GENL_ADMIN_PERM,
1369 	},
1370 };
1371 
1372 static struct genl_family gtp_genl_family __ro_after_init = {
1373 	.name		= "gtp",
1374 	.version	= 0,
1375 	.hdrsize	= 0,
1376 	.maxattr	= GTPA_MAX,
1377 	.policy = gtp_genl_policy,
1378 	.netnsok	= true,
1379 	.module		= THIS_MODULE,
1380 	.small_ops	= gtp_genl_ops,
1381 	.n_small_ops	= ARRAY_SIZE(gtp_genl_ops),
1382 	.mcgrps		= gtp_genl_mcgrps,
1383 	.n_mcgrps	= ARRAY_SIZE(gtp_genl_mcgrps),
1384 };
1385 
1386 static int __net_init gtp_net_init(struct net *net)
1387 {
1388 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1389 
1390 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1391 	return 0;
1392 }
1393 
1394 static void __net_exit gtp_net_exit(struct net *net)
1395 {
1396 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1397 	struct gtp_dev *gtp;
1398 	LIST_HEAD(list);
1399 
1400 	rtnl_lock();
1401 	list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1402 		gtp_dellink(gtp->dev, &list);
1403 
1404 	unregister_netdevice_many(&list);
1405 	rtnl_unlock();
1406 }
1407 
1408 static struct pernet_operations gtp_net_ops = {
1409 	.init	= gtp_net_init,
1410 	.exit	= gtp_net_exit,
1411 	.id	= &gtp_net_id,
1412 	.size	= sizeof(struct gtp_net),
1413 };
1414 
1415 static int __init gtp_init(void)
1416 {
1417 	int err;
1418 
1419 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1420 
1421 	err = rtnl_link_register(&gtp_link_ops);
1422 	if (err < 0)
1423 		goto error_out;
1424 
1425 	err = genl_register_family(&gtp_genl_family);
1426 	if (err < 0)
1427 		goto unreg_rtnl_link;
1428 
1429 	err = register_pernet_subsys(&gtp_net_ops);
1430 	if (err < 0)
1431 		goto unreg_genl_family;
1432 
1433 	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1434 		sizeof(struct pdp_ctx));
1435 	return 0;
1436 
1437 unreg_genl_family:
1438 	genl_unregister_family(&gtp_genl_family);
1439 unreg_rtnl_link:
1440 	rtnl_link_unregister(&gtp_link_ops);
1441 error_out:
1442 	pr_err("error loading GTP module loaded\n");
1443 	return err;
1444 }
1445 late_initcall(gtp_init);
1446 
1447 static void __exit gtp_fini(void)
1448 {
1449 	genl_unregister_family(&gtp_genl_family);
1450 	rtnl_link_unregister(&gtp_link_ops);
1451 	unregister_pernet_subsys(&gtp_net_ops);
1452 
1453 	pr_info("GTP module unloaded\n");
1454 }
1455 module_exit(gtp_fini);
1456 
1457 MODULE_LICENSE("GPL");
1458 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1459 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1460 MODULE_ALIAS_RTNL_LINK("gtp");
1461 MODULE_ALIAS_GENL_FAMILY("gtp");
1462