xref: /linux/drivers/net/gtp.c (revision 07214013578b156d0fda288a0311d353ea149674)
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 	u8			sk_created;
70 
71 	struct net_device	*dev;
72 	struct net		*net;
73 
74 	unsigned int		role;
75 	unsigned int		hash_size;
76 	struct hlist_head	*tid_hash;
77 	struct hlist_head	*addr_hash;
78 
79 	u8			restart_count;
80 };
81 
82 struct echo_info {
83 	struct in_addr		ms_addr_ip4;
84 	struct in_addr		peer_addr_ip4;
85 	u8			gtp_version;
86 };
87 
88 static unsigned int gtp_net_id __read_mostly;
89 
90 struct gtp_net {
91 	struct list_head gtp_dev_list;
92 };
93 
94 static u32 gtp_h_initval;
95 
96 static struct genl_family gtp_genl_family;
97 
98 enum gtp_multicast_groups {
99 	GTP_GENL_MCGRP,
100 };
101 
102 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
103 	[GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
104 };
105 
106 static void pdp_context_delete(struct pdp_ctx *pctx);
107 
108 static inline u32 gtp0_hashfn(u64 tid)
109 {
110 	u32 *tid32 = (u32 *) &tid;
111 	return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
112 }
113 
114 static inline u32 gtp1u_hashfn(u32 tid)
115 {
116 	return jhash_1word(tid, gtp_h_initval);
117 }
118 
119 static inline u32 ipv4_hashfn(__be32 ip)
120 {
121 	return jhash_1word((__force u32)ip, gtp_h_initval);
122 }
123 
124 /* Resolve a PDP context structure based on the 64bit TID. */
125 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
126 {
127 	struct hlist_head *head;
128 	struct pdp_ctx *pdp;
129 
130 	head = &gtp->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
131 
132 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
133 		if (pdp->gtp_version == GTP_V0 &&
134 		    pdp->u.v0.tid == tid)
135 			return pdp;
136 	}
137 	return NULL;
138 }
139 
140 /* Resolve a PDP context structure based on the 32bit TEI. */
141 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
142 {
143 	struct hlist_head *head;
144 	struct pdp_ctx *pdp;
145 
146 	head = &gtp->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
147 
148 	hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
149 		if (pdp->gtp_version == GTP_V1 &&
150 		    pdp->u.v1.i_tei == tid)
151 			return pdp;
152 	}
153 	return NULL;
154 }
155 
156 /* Resolve a PDP context based on IPv4 address of MS. */
157 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
158 {
159 	struct hlist_head *head;
160 	struct pdp_ctx *pdp;
161 
162 	head = &gtp->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
163 
164 	hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
165 		if (pdp->af == AF_INET &&
166 		    pdp->ms_addr_ip4.s_addr == ms_addr)
167 			return pdp;
168 	}
169 
170 	return NULL;
171 }
172 
173 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
174 				  unsigned int hdrlen, unsigned int role)
175 {
176 	struct iphdr *iph;
177 
178 	if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
179 		return false;
180 
181 	iph = (struct iphdr *)(skb->data + hdrlen);
182 
183 	if (role == GTP_ROLE_SGSN)
184 		return iph->daddr == pctx->ms_addr_ip4.s_addr;
185 	else
186 		return iph->saddr == pctx->ms_addr_ip4.s_addr;
187 }
188 
189 /* Check if the inner IP address in this packet is assigned to any
190  * existing mobile subscriber.
191  */
192 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
193 			     unsigned int hdrlen, unsigned int role)
194 {
195 	switch (ntohs(skb->protocol)) {
196 	case ETH_P_IP:
197 		return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
198 	}
199 	return false;
200 }
201 
202 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
203 			unsigned int hdrlen, unsigned int role)
204 {
205 	if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
206 		netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
207 		return 1;
208 	}
209 
210 	/* Get rid of the GTP + UDP headers. */
211 	if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
212 			 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
213 		pctx->dev->stats.rx_length_errors++;
214 		goto err;
215 	}
216 
217 	netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
218 
219 	/* Now that the UDP and the GTP header have been removed, set up the
220 	 * new network header. This is required by the upper layer to
221 	 * calculate the transport header.
222 	 */
223 	skb_reset_network_header(skb);
224 	skb_reset_mac_header(skb);
225 
226 	skb->dev = pctx->dev;
227 
228 	dev_sw_netstats_rx_add(pctx->dev, skb->len);
229 
230 	__netif_rx(skb);
231 	return 0;
232 
233 err:
234 	pctx->dev->stats.rx_dropped++;
235 	return -1;
236 }
237 
238 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
239 					   const struct sock *sk,
240 					   __be32 daddr, __be32 saddr)
241 {
242 	memset(fl4, 0, sizeof(*fl4));
243 	fl4->flowi4_oif		= sk->sk_bound_dev_if;
244 	fl4->daddr		= daddr;
245 	fl4->saddr		= saddr;
246 	fl4->flowi4_tos		= ip_sock_rt_tos(sk);
247 	fl4->flowi4_scope	= ip_sock_rt_scope(sk);
248 	fl4->flowi4_proto	= sk->sk_protocol;
249 
250 	return ip_route_output_key(sock_net(sk), fl4);
251 }
252 
253 /* GSM TS 09.60. 7.3
254  * In all Path Management messages:
255  * - TID: is not used and shall be set to 0.
256  * - Flow Label is not used and shall be set to 0
257  * In signalling messages:
258  * - number: this field is not yet used in signalling messages.
259  *   It shall be set to 255 by the sender and shall be ignored
260  *   by the receiver
261  * Returns true if the echo req was correct, false otherwise.
262  */
263 static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0)
264 {
265 	return !(gtp0->tid || (gtp0->flags ^ 0x1e) ||
266 		gtp0->number != 0xff || gtp0->flow);
267 }
268 
269 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
270 static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type)
271 {
272 	int len_pkt, len_hdr;
273 
274 	hdr->flags = 0x1e; /* v0, GTP-non-prime. */
275 	hdr->type = msg_type;
276 	/* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID
277 	 * are not used and shall be set to 0.
278 	 */
279 	hdr->flow = 0;
280 	hdr->tid = 0;
281 	hdr->number = 0xff;
282 	hdr->spare[0] = 0xff;
283 	hdr->spare[1] = 0xff;
284 	hdr->spare[2] = 0xff;
285 
286 	len_pkt = sizeof(struct gtp0_packet);
287 	len_hdr = sizeof(struct gtp0_header);
288 
289 	if (msg_type == GTP_ECHO_RSP)
290 		hdr->length = htons(len_pkt - len_hdr);
291 	else
292 		hdr->length = 0;
293 }
294 
295 static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
296 {
297 	struct gtp0_packet *gtp_pkt;
298 	struct gtp0_header *gtp0;
299 	struct rtable *rt;
300 	struct flowi4 fl4;
301 	struct iphdr *iph;
302 	__be16 seq;
303 
304 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
305 
306 	if (!gtp0_validate_echo_hdr(gtp0))
307 		return -1;
308 
309 	seq = gtp0->seq;
310 
311 	/* pull GTP and UDP headers */
312 	skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr));
313 
314 	gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet));
315 	memset(gtp_pkt, 0, sizeof(struct gtp0_packet));
316 
317 	gtp0_build_echo_msg(&gtp_pkt->gtp0_h, GTP_ECHO_RSP);
318 
319 	/* GSM TS 09.60. 7.3 The Sequence Number in a signalling response
320 	 * message shall be copied from the signalling request message
321 	 * that the GSN is replying to.
322 	 */
323 	gtp_pkt->gtp0_h.seq = seq;
324 
325 	gtp_pkt->ie.tag = GTPIE_RECOVERY;
326 	gtp_pkt->ie.val = gtp->restart_count;
327 
328 	iph = ip_hdr(skb);
329 
330 	/* find route to the sender,
331 	 * src address becomes dst address and vice versa.
332 	 */
333 	rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr);
334 	if (IS_ERR(rt)) {
335 		netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
336 			   &iph->saddr);
337 		return -1;
338 	}
339 
340 	udp_tunnel_xmit_skb(rt, gtp->sk0, skb,
341 			    fl4.saddr, fl4.daddr,
342 			    iph->tos,
343 			    ip4_dst_hoplimit(&rt->dst),
344 			    0,
345 			    htons(GTP0_PORT), htons(GTP0_PORT),
346 			    !net_eq(sock_net(gtp->sk1u),
347 				    dev_net(gtp->dev)),
348 			    false);
349 	return 0;
350 }
351 
352 static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
353 			      int flags, u32 type, struct echo_info echo)
354 {
355 	void *genlh;
356 
357 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
358 			    type);
359 	if (!genlh)
360 		goto failure;
361 
362 	if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) ||
363 	    nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer_addr_ip4.s_addr) ||
364 	    nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms_addr_ip4.s_addr))
365 		goto failure;
366 
367 	genlmsg_end(skb, genlh);
368 	return 0;
369 
370 failure:
371 	genlmsg_cancel(skb, genlh);
372 	return -EMSGSIZE;
373 }
374 
375 static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
376 {
377 	struct gtp0_header *gtp0;
378 	struct echo_info echo;
379 	struct sk_buff *msg;
380 	struct iphdr *iph;
381 	int ret;
382 
383 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
384 
385 	if (!gtp0_validate_echo_hdr(gtp0))
386 		return -1;
387 
388 	iph = ip_hdr(skb);
389 	echo.ms_addr_ip4.s_addr = iph->daddr;
390 	echo.peer_addr_ip4.s_addr = iph->saddr;
391 	echo.gtp_version = GTP_V0;
392 
393 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
394 	if (!msg)
395 		return -ENOMEM;
396 
397 	ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
398 	if (ret < 0) {
399 		nlmsg_free(msg);
400 		return ret;
401 	}
402 
403 	return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
404 				       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
405 }
406 
407 /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
408 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
409 {
410 	unsigned int hdrlen = sizeof(struct udphdr) +
411 			      sizeof(struct gtp0_header);
412 	struct gtp0_header *gtp0;
413 	struct pdp_ctx *pctx;
414 
415 	if (!pskb_may_pull(skb, hdrlen))
416 		return -1;
417 
418 	gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
419 
420 	if ((gtp0->flags >> 5) != GTP_V0)
421 		return 1;
422 
423 	/* If the sockets were created in kernel, it means that
424 	 * there is no daemon running in userspace which would
425 	 * handle echo request.
426 	 */
427 	if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
428 		return gtp0_send_echo_resp(gtp, skb);
429 
430 	if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created)
431 		return gtp0_handle_echo_resp(gtp, skb);
432 
433 	if (gtp0->type != GTP_TPDU)
434 		return 1;
435 
436 	pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
437 	if (!pctx) {
438 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
439 		return 1;
440 	}
441 
442 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
443 }
444 
445 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
446 static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type)
447 {
448 	int len_pkt, len_hdr;
449 
450 	/* S flag must be set to 1 */
451 	hdr->flags = 0x32; /* v1, GTP-non-prime. */
452 	hdr->type = msg_type;
453 	/* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */
454 	hdr->tid = 0;
455 
456 	/* seq, npdu and next should be counted to the length of the GTP packet
457 	 * that's why szie of gtp1_header should be subtracted,
458 	 * not size of gtp1_header_long.
459 	 */
460 
461 	len_hdr = sizeof(struct gtp1_header);
462 
463 	if (msg_type == GTP_ECHO_RSP) {
464 		len_pkt = sizeof(struct gtp1u_packet);
465 		hdr->length = htons(len_pkt - len_hdr);
466 	} else {
467 		/* GTP_ECHO_REQ does not carry GTP Information Element,
468 		 * the why gtp1_header_long is used here.
469 		 */
470 		len_pkt = sizeof(struct gtp1_header_long);
471 		hdr->length = htons(len_pkt - len_hdr);
472 	}
473 }
474 
475 static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
476 {
477 	struct gtp1_header_long *gtp1u;
478 	struct gtp1u_packet *gtp_pkt;
479 	struct rtable *rt;
480 	struct flowi4 fl4;
481 	struct iphdr *iph;
482 
483 	gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
484 
485 	/* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
486 	 * Error Indication and Supported Extension Headers Notification
487 	 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
488 	 */
489 	if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
490 		return -1;
491 
492 	/* pull GTP and UDP headers */
493 	skb_pull_data(skb,
494 		      sizeof(struct gtp1_header_long) + sizeof(struct udphdr));
495 
496 	gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet));
497 	memset(gtp_pkt, 0, sizeof(struct gtp1u_packet));
498 
499 	gtp1u_build_echo_msg(&gtp_pkt->gtp1u_h, GTP_ECHO_RSP);
500 
501 	/* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the
502 	 * Recovery information element shall not be used, i.e. it shall
503 	 * be set to zero by the sender and shall be ignored by the receiver.
504 	 * The Recovery information element is mandatory due to backwards
505 	 * compatibility reasons.
506 	 */
507 	gtp_pkt->ie.tag = GTPIE_RECOVERY;
508 	gtp_pkt->ie.val = 0;
509 
510 	iph = ip_hdr(skb);
511 
512 	/* find route to the sender,
513 	 * src address becomes dst address and vice versa.
514 	 */
515 	rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr);
516 	if (IS_ERR(rt)) {
517 		netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
518 			   &iph->saddr);
519 		return -1;
520 	}
521 
522 	udp_tunnel_xmit_skb(rt, gtp->sk1u, skb,
523 			    fl4.saddr, fl4.daddr,
524 			    iph->tos,
525 			    ip4_dst_hoplimit(&rt->dst),
526 			    0,
527 			    htons(GTP1U_PORT), htons(GTP1U_PORT),
528 			    !net_eq(sock_net(gtp->sk1u),
529 				    dev_net(gtp->dev)),
530 			    false);
531 	return 0;
532 }
533 
534 static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
535 {
536 	struct gtp1_header_long *gtp1u;
537 	struct echo_info echo;
538 	struct sk_buff *msg;
539 	struct iphdr *iph;
540 	int ret;
541 
542 	gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
543 
544 	/* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
545 	 * Error Indication and Supported Extension Headers Notification
546 	 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
547 	 */
548 	if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
549 		return -1;
550 
551 	iph = ip_hdr(skb);
552 	echo.ms_addr_ip4.s_addr = iph->daddr;
553 	echo.peer_addr_ip4.s_addr = iph->saddr;
554 	echo.gtp_version = GTP_V1;
555 
556 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
557 	if (!msg)
558 		return -ENOMEM;
559 
560 	ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
561 	if (ret < 0) {
562 		nlmsg_free(msg);
563 		return ret;
564 	}
565 
566 	return genlmsg_multicast_netns(&gtp_genl_family, dev_net(gtp->dev),
567 				       msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
568 }
569 
570 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
571 {
572 	unsigned int hdrlen = sizeof(struct udphdr) +
573 			      sizeof(struct gtp1_header);
574 	struct gtp1_header *gtp1;
575 	struct pdp_ctx *pctx;
576 
577 	if (!pskb_may_pull(skb, hdrlen))
578 		return -1;
579 
580 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
581 
582 	if ((gtp1->flags >> 5) != GTP_V1)
583 		return 1;
584 
585 	/* If the sockets were created in kernel, it means that
586 	 * there is no daemon running in userspace which would
587 	 * handle echo request.
588 	 */
589 	if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)
590 		return gtp1u_send_echo_resp(gtp, skb);
591 
592 	if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created)
593 		return gtp1u_handle_echo_resp(gtp, skb);
594 
595 	if (gtp1->type != GTP_TPDU)
596 		return 1;
597 
598 	/* From 29.060: "This field shall be present if and only if any one or
599 	 * more of the S, PN and E flags are set.".
600 	 *
601 	 * If any of the bit is set, then the remaining ones also have to be
602 	 * set.
603 	 */
604 	if (gtp1->flags & GTP1_F_MASK)
605 		hdrlen += 4;
606 
607 	/* Make sure the header is larger enough, including extensions. */
608 	if (!pskb_may_pull(skb, hdrlen))
609 		return -1;
610 
611 	gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
612 
613 	pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
614 	if (!pctx) {
615 		netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
616 		return 1;
617 	}
618 
619 	return gtp_rx(pctx, skb, hdrlen, gtp->role);
620 }
621 
622 static void __gtp_encap_destroy(struct sock *sk)
623 {
624 	struct gtp_dev *gtp;
625 
626 	lock_sock(sk);
627 	gtp = sk->sk_user_data;
628 	if (gtp) {
629 		if (gtp->sk0 == sk)
630 			gtp->sk0 = NULL;
631 		else
632 			gtp->sk1u = NULL;
633 		WRITE_ONCE(udp_sk(sk)->encap_type, 0);
634 		rcu_assign_sk_user_data(sk, NULL);
635 		release_sock(sk);
636 		sock_put(sk);
637 		return;
638 	}
639 	release_sock(sk);
640 }
641 
642 static void gtp_encap_destroy(struct sock *sk)
643 {
644 	rtnl_lock();
645 	__gtp_encap_destroy(sk);
646 	rtnl_unlock();
647 }
648 
649 static void gtp_encap_disable_sock(struct sock *sk)
650 {
651 	if (!sk)
652 		return;
653 
654 	__gtp_encap_destroy(sk);
655 }
656 
657 static void gtp_encap_disable(struct gtp_dev *gtp)
658 {
659 	if (gtp->sk_created) {
660 		udp_tunnel_sock_release(gtp->sk0->sk_socket);
661 		udp_tunnel_sock_release(gtp->sk1u->sk_socket);
662 		gtp->sk_created = false;
663 		gtp->sk0 = NULL;
664 		gtp->sk1u = NULL;
665 	} else {
666 		gtp_encap_disable_sock(gtp->sk0);
667 		gtp_encap_disable_sock(gtp->sk1u);
668 	}
669 }
670 
671 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
672  * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
673  */
674 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
675 {
676 	struct gtp_dev *gtp;
677 	int ret = 0;
678 
679 	gtp = rcu_dereference_sk_user_data(sk);
680 	if (!gtp)
681 		return 1;
682 
683 	netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
684 
685 	switch (READ_ONCE(udp_sk(sk)->encap_type)) {
686 	case UDP_ENCAP_GTP0:
687 		netdev_dbg(gtp->dev, "received GTP0 packet\n");
688 		ret = gtp0_udp_encap_recv(gtp, skb);
689 		break;
690 	case UDP_ENCAP_GTP1U:
691 		netdev_dbg(gtp->dev, "received GTP1U packet\n");
692 		ret = gtp1u_udp_encap_recv(gtp, skb);
693 		break;
694 	default:
695 		ret = -1; /* Shouldn't happen. */
696 	}
697 
698 	switch (ret) {
699 	case 1:
700 		netdev_dbg(gtp->dev, "pass up to the process\n");
701 		break;
702 	case 0:
703 		break;
704 	case -1:
705 		netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
706 		kfree_skb(skb);
707 		ret = 0;
708 		break;
709 	}
710 
711 	return ret;
712 }
713 
714 static void gtp_dev_uninit(struct net_device *dev)
715 {
716 	struct gtp_dev *gtp = netdev_priv(dev);
717 
718 	gtp_encap_disable(gtp);
719 }
720 
721 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
722 {
723 	int payload_len = skb->len;
724 	struct gtp0_header *gtp0;
725 
726 	gtp0 = skb_push(skb, sizeof(*gtp0));
727 
728 	gtp0->flags	= 0x1e; /* v0, GTP-non-prime. */
729 	gtp0->type	= GTP_TPDU;
730 	gtp0->length	= htons(payload_len);
731 	gtp0->seq	= htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
732 	gtp0->flow	= htons(pctx->u.v0.flow);
733 	gtp0->number	= 0xff;
734 	gtp0->spare[0]	= gtp0->spare[1] = gtp0->spare[2] = 0xff;
735 	gtp0->tid	= cpu_to_be64(pctx->u.v0.tid);
736 }
737 
738 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
739 {
740 	int payload_len = skb->len;
741 	struct gtp1_header *gtp1;
742 
743 	gtp1 = skb_push(skb, sizeof(*gtp1));
744 
745 	/* Bits    8  7  6  5  4  3  2	1
746 	 *	  +--+--+--+--+--+--+--+--+
747 	 *	  |version |PT| 0| E| S|PN|
748 	 *	  +--+--+--+--+--+--+--+--+
749 	 *	    0  0  1  1	1  0  0  0
750 	 */
751 	gtp1->flags	= 0x30; /* v1, GTP-non-prime. */
752 	gtp1->type	= GTP_TPDU;
753 	gtp1->length	= htons(payload_len);
754 	gtp1->tid	= htonl(pctx->u.v1.o_tei);
755 
756 	/* TODO: Support for extension header, sequence number and N-PDU.
757 	 *	 Update the length field if any of them is available.
758 	 */
759 }
760 
761 struct gtp_pktinfo {
762 	struct sock		*sk;
763 	struct iphdr		*iph;
764 	struct flowi4		fl4;
765 	struct rtable		*rt;
766 	struct pdp_ctx		*pctx;
767 	struct net_device	*dev;
768 	__be16			gtph_port;
769 };
770 
771 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
772 {
773 	switch (pktinfo->pctx->gtp_version) {
774 	case GTP_V0:
775 		pktinfo->gtph_port = htons(GTP0_PORT);
776 		gtp0_push_header(skb, pktinfo->pctx);
777 		break;
778 	case GTP_V1:
779 		pktinfo->gtph_port = htons(GTP1U_PORT);
780 		gtp1_push_header(skb, pktinfo->pctx);
781 		break;
782 	}
783 }
784 
785 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
786 					struct sock *sk, struct iphdr *iph,
787 					struct pdp_ctx *pctx, struct rtable *rt,
788 					struct flowi4 *fl4,
789 					struct net_device *dev)
790 {
791 	pktinfo->sk	= sk;
792 	pktinfo->iph	= iph;
793 	pktinfo->pctx	= pctx;
794 	pktinfo->rt	= rt;
795 	pktinfo->fl4	= *fl4;
796 	pktinfo->dev	= dev;
797 }
798 
799 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
800 			     struct gtp_pktinfo *pktinfo)
801 {
802 	struct gtp_dev *gtp = netdev_priv(dev);
803 	struct pdp_ctx *pctx;
804 	struct rtable *rt;
805 	struct flowi4 fl4;
806 	struct iphdr *iph;
807 	__be16 df;
808 	int mtu;
809 
810 	/* Read the IP destination address and resolve the PDP context.
811 	 * Prepend PDP header with TEI/TID from PDP ctx.
812 	 */
813 	iph = ip_hdr(skb);
814 	if (gtp->role == GTP_ROLE_SGSN)
815 		pctx = ipv4_pdp_find(gtp, iph->saddr);
816 	else
817 		pctx = ipv4_pdp_find(gtp, iph->daddr);
818 
819 	if (!pctx) {
820 		netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
821 			   &iph->daddr);
822 		return -ENOENT;
823 	}
824 	netdev_dbg(dev, "found PDP context %p\n", pctx);
825 
826 	rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr,
827 				  inet_sk(pctx->sk)->inet_saddr);
828 	if (IS_ERR(rt)) {
829 		netdev_dbg(dev, "no route to SSGN %pI4\n",
830 			   &pctx->peer_addr_ip4.s_addr);
831 		dev->stats.tx_carrier_errors++;
832 		goto err;
833 	}
834 
835 	if (rt->dst.dev == dev) {
836 		netdev_dbg(dev, "circular route to SSGN %pI4\n",
837 			   &pctx->peer_addr_ip4.s_addr);
838 		dev->stats.collisions++;
839 		goto err_rt;
840 	}
841 
842 	/* This is similar to tnl_update_pmtu(). */
843 	df = iph->frag_off;
844 	if (df) {
845 		mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
846 			sizeof(struct iphdr) - sizeof(struct udphdr);
847 		switch (pctx->gtp_version) {
848 		case GTP_V0:
849 			mtu -= sizeof(struct gtp0_header);
850 			break;
851 		case GTP_V1:
852 			mtu -= sizeof(struct gtp1_header);
853 			break;
854 		}
855 	} else {
856 		mtu = dst_mtu(&rt->dst);
857 	}
858 
859 	skb_dst_update_pmtu_no_confirm(skb, mtu);
860 
861 	if (iph->frag_off & htons(IP_DF) &&
862 	    ((!skb_is_gso(skb) && skb->len > mtu) ||
863 	     (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
864 		netdev_dbg(dev, "packet too big, fragmentation needed\n");
865 		icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
866 			      htonl(mtu));
867 		goto err_rt;
868 	}
869 
870 	gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
871 	gtp_push_header(skb, pktinfo);
872 
873 	return 0;
874 err_rt:
875 	ip_rt_put(rt);
876 err:
877 	return -EBADMSG;
878 }
879 
880 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
881 {
882 	unsigned int proto = ntohs(skb->protocol);
883 	struct gtp_pktinfo pktinfo;
884 	int err;
885 
886 	/* Ensure there is sufficient headroom. */
887 	if (skb_cow_head(skb, dev->needed_headroom))
888 		goto tx_err;
889 
890 	skb_reset_inner_headers(skb);
891 
892 	/* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
893 	rcu_read_lock();
894 	switch (proto) {
895 	case ETH_P_IP:
896 		err = gtp_build_skb_ip4(skb, dev, &pktinfo);
897 		break;
898 	default:
899 		err = -EOPNOTSUPP;
900 		break;
901 	}
902 	rcu_read_unlock();
903 
904 	if (err < 0)
905 		goto tx_err;
906 
907 	switch (proto) {
908 	case ETH_P_IP:
909 		netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
910 			   &pktinfo.iph->saddr, &pktinfo.iph->daddr);
911 		udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
912 				    pktinfo.fl4.saddr, pktinfo.fl4.daddr,
913 				    pktinfo.iph->tos,
914 				    ip4_dst_hoplimit(&pktinfo.rt->dst),
915 				    0,
916 				    pktinfo.gtph_port, pktinfo.gtph_port,
917 				    !net_eq(sock_net(pktinfo.pctx->sk),
918 					    dev_net(dev)),
919 				    false);
920 		break;
921 	}
922 
923 	return NETDEV_TX_OK;
924 tx_err:
925 	dev->stats.tx_errors++;
926 	dev_kfree_skb(skb);
927 	return NETDEV_TX_OK;
928 }
929 
930 static const struct net_device_ops gtp_netdev_ops = {
931 	.ndo_uninit		= gtp_dev_uninit,
932 	.ndo_start_xmit		= gtp_dev_xmit,
933 };
934 
935 static const struct device_type gtp_type = {
936 	.name = "gtp",
937 };
938 
939 static void gtp_link_setup(struct net_device *dev)
940 {
941 	unsigned int max_gtp_header_len = sizeof(struct iphdr) +
942 					  sizeof(struct udphdr) +
943 					  sizeof(struct gtp0_header);
944 	struct gtp_dev *gtp = netdev_priv(dev);
945 
946 	dev->netdev_ops		= &gtp_netdev_ops;
947 	dev->needs_free_netdev	= true;
948 	SET_NETDEV_DEVTYPE(dev, &gtp_type);
949 
950 	dev->hard_header_len = 0;
951 	dev->addr_len = 0;
952 	dev->mtu = ETH_DATA_LEN - max_gtp_header_len;
953 
954 	/* Zero header length. */
955 	dev->type = ARPHRD_NONE;
956 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
957 
958 	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
959 	dev->priv_flags	|= IFF_NO_QUEUE;
960 	dev->features	|= NETIF_F_LLTX;
961 	netif_keep_dst(dev);
962 
963 	dev->needed_headroom	= LL_MAX_HEADER + max_gtp_header_len;
964 	gtp->dev = dev;
965 }
966 
967 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
968 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
969 
970 static void gtp_destructor(struct net_device *dev)
971 {
972 	struct gtp_dev *gtp = netdev_priv(dev);
973 
974 	kfree(gtp->addr_hash);
975 	kfree(gtp->tid_hash);
976 }
977 
978 static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp)
979 {
980 	struct udp_tunnel_sock_cfg tuncfg = {};
981 	struct udp_port_cfg udp_conf = {
982 		.local_ip.s_addr	= htonl(INADDR_ANY),
983 		.family			= AF_INET,
984 	};
985 	struct net *net = gtp->net;
986 	struct socket *sock;
987 	int err;
988 
989 	if (type == UDP_ENCAP_GTP0)
990 		udp_conf.local_udp_port = htons(GTP0_PORT);
991 	else if (type == UDP_ENCAP_GTP1U)
992 		udp_conf.local_udp_port = htons(GTP1U_PORT);
993 	else
994 		return ERR_PTR(-EINVAL);
995 
996 	err = udp_sock_create(net, &udp_conf, &sock);
997 	if (err)
998 		return ERR_PTR(err);
999 
1000 	tuncfg.sk_user_data = gtp;
1001 	tuncfg.encap_type = type;
1002 	tuncfg.encap_rcv = gtp_encap_recv;
1003 	tuncfg.encap_destroy = NULL;
1004 
1005 	setup_udp_tunnel_sock(net, sock, &tuncfg);
1006 
1007 	return sock->sk;
1008 }
1009 
1010 static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[])
1011 {
1012 	struct sock *sk1u = NULL;
1013 	struct sock *sk0 = NULL;
1014 
1015 	sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp);
1016 	if (IS_ERR(sk0))
1017 		return PTR_ERR(sk0);
1018 
1019 	sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp);
1020 	if (IS_ERR(sk1u)) {
1021 		udp_tunnel_sock_release(sk0->sk_socket);
1022 		return PTR_ERR(sk1u);
1023 	}
1024 
1025 	gtp->sk_created = true;
1026 	gtp->sk0 = sk0;
1027 	gtp->sk1u = sk1u;
1028 
1029 	return 0;
1030 }
1031 
1032 static int gtp_newlink(struct net *src_net, struct net_device *dev,
1033 		       struct nlattr *tb[], struct nlattr *data[],
1034 		       struct netlink_ext_ack *extack)
1035 {
1036 	unsigned int role = GTP_ROLE_GGSN;
1037 	struct gtp_dev *gtp;
1038 	struct gtp_net *gn;
1039 	int hashsize, err;
1040 
1041 	gtp = netdev_priv(dev);
1042 
1043 	if (!data[IFLA_GTP_PDP_HASHSIZE]) {
1044 		hashsize = 1024;
1045 	} else {
1046 		hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
1047 		if (!hashsize)
1048 			hashsize = 1024;
1049 	}
1050 
1051 	if (data[IFLA_GTP_ROLE]) {
1052 		role = nla_get_u32(data[IFLA_GTP_ROLE]);
1053 		if (role > GTP_ROLE_SGSN)
1054 			return -EINVAL;
1055 	}
1056 	gtp->role = role;
1057 
1058 	if (!data[IFLA_GTP_RESTART_COUNT])
1059 		gtp->restart_count = 0;
1060 	else
1061 		gtp->restart_count = nla_get_u8(data[IFLA_GTP_RESTART_COUNT]);
1062 
1063 	gtp->net = src_net;
1064 
1065 	err = gtp_hashtable_new(gtp, hashsize);
1066 	if (err < 0)
1067 		return err;
1068 
1069 	if (data[IFLA_GTP_CREATE_SOCKETS])
1070 		err = gtp_create_sockets(gtp, data);
1071 	else
1072 		err = gtp_encap_enable(gtp, data);
1073 	if (err < 0)
1074 		goto out_hashtable;
1075 
1076 	err = register_netdevice(dev);
1077 	if (err < 0) {
1078 		netdev_dbg(dev, "failed to register new netdev %d\n", err);
1079 		goto out_encap;
1080 	}
1081 
1082 	gn = net_generic(dev_net(dev), gtp_net_id);
1083 	list_add_rcu(&gtp->list, &gn->gtp_dev_list);
1084 	dev->priv_destructor = gtp_destructor;
1085 
1086 	netdev_dbg(dev, "registered new GTP interface\n");
1087 
1088 	return 0;
1089 
1090 out_encap:
1091 	gtp_encap_disable(gtp);
1092 out_hashtable:
1093 	kfree(gtp->addr_hash);
1094 	kfree(gtp->tid_hash);
1095 	return err;
1096 }
1097 
1098 static void gtp_dellink(struct net_device *dev, struct list_head *head)
1099 {
1100 	struct gtp_dev *gtp = netdev_priv(dev);
1101 	struct hlist_node *next;
1102 	struct pdp_ctx *pctx;
1103 	int i;
1104 
1105 	for (i = 0; i < gtp->hash_size; i++)
1106 		hlist_for_each_entry_safe(pctx, next, &gtp->tid_hash[i], hlist_tid)
1107 			pdp_context_delete(pctx);
1108 
1109 	list_del_rcu(&gtp->list);
1110 	unregister_netdevice_queue(dev, head);
1111 }
1112 
1113 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
1114 	[IFLA_GTP_FD0]			= { .type = NLA_U32 },
1115 	[IFLA_GTP_FD1]			= { .type = NLA_U32 },
1116 	[IFLA_GTP_PDP_HASHSIZE]		= { .type = NLA_U32 },
1117 	[IFLA_GTP_ROLE]			= { .type = NLA_U32 },
1118 	[IFLA_GTP_CREATE_SOCKETS]	= { .type = NLA_U8 },
1119 	[IFLA_GTP_RESTART_COUNT]	= { .type = NLA_U8 },
1120 };
1121 
1122 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
1123 			struct netlink_ext_ack *extack)
1124 {
1125 	if (!data)
1126 		return -EINVAL;
1127 
1128 	return 0;
1129 }
1130 
1131 static size_t gtp_get_size(const struct net_device *dev)
1132 {
1133 	return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
1134 		nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
1135 		nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
1136 }
1137 
1138 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
1139 {
1140 	struct gtp_dev *gtp = netdev_priv(dev);
1141 
1142 	if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
1143 		goto nla_put_failure;
1144 	if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
1145 		goto nla_put_failure;
1146 	if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
1147 		goto nla_put_failure;
1148 
1149 	return 0;
1150 
1151 nla_put_failure:
1152 	return -EMSGSIZE;
1153 }
1154 
1155 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
1156 	.kind		= "gtp",
1157 	.maxtype	= IFLA_GTP_MAX,
1158 	.policy		= gtp_policy,
1159 	.priv_size	= sizeof(struct gtp_dev),
1160 	.setup		= gtp_link_setup,
1161 	.validate	= gtp_validate,
1162 	.newlink	= gtp_newlink,
1163 	.dellink	= gtp_dellink,
1164 	.get_size	= gtp_get_size,
1165 	.fill_info	= gtp_fill_info,
1166 };
1167 
1168 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
1169 {
1170 	int i;
1171 
1172 	gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1173 				       GFP_KERNEL | __GFP_NOWARN);
1174 	if (gtp->addr_hash == NULL)
1175 		return -ENOMEM;
1176 
1177 	gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1178 				      GFP_KERNEL | __GFP_NOWARN);
1179 	if (gtp->tid_hash == NULL)
1180 		goto err1;
1181 
1182 	gtp->hash_size = hsize;
1183 
1184 	for (i = 0; i < hsize; i++) {
1185 		INIT_HLIST_HEAD(&gtp->addr_hash[i]);
1186 		INIT_HLIST_HEAD(&gtp->tid_hash[i]);
1187 	}
1188 	return 0;
1189 err1:
1190 	kfree(gtp->addr_hash);
1191 	return -ENOMEM;
1192 }
1193 
1194 static struct sock *gtp_encap_enable_socket(int fd, int type,
1195 					    struct gtp_dev *gtp)
1196 {
1197 	struct udp_tunnel_sock_cfg tuncfg = {NULL};
1198 	struct socket *sock;
1199 	struct sock *sk;
1200 	int err;
1201 
1202 	pr_debug("enable gtp on %d, %d\n", fd, type);
1203 
1204 	sock = sockfd_lookup(fd, &err);
1205 	if (!sock) {
1206 		pr_debug("gtp socket fd=%d not found\n", fd);
1207 		return NULL;
1208 	}
1209 
1210 	sk = sock->sk;
1211 	if (sk->sk_protocol != IPPROTO_UDP ||
1212 	    sk->sk_type != SOCK_DGRAM ||
1213 	    (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
1214 		pr_debug("socket fd=%d not UDP\n", fd);
1215 		sk = ERR_PTR(-EINVAL);
1216 		goto out_sock;
1217 	}
1218 
1219 	lock_sock(sk);
1220 	if (sk->sk_user_data) {
1221 		sk = ERR_PTR(-EBUSY);
1222 		goto out_rel_sock;
1223 	}
1224 
1225 	sock_hold(sk);
1226 
1227 	tuncfg.sk_user_data = gtp;
1228 	tuncfg.encap_type = type;
1229 	tuncfg.encap_rcv = gtp_encap_recv;
1230 	tuncfg.encap_destroy = gtp_encap_destroy;
1231 
1232 	setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
1233 
1234 out_rel_sock:
1235 	release_sock(sock->sk);
1236 out_sock:
1237 	sockfd_put(sock);
1238 	return sk;
1239 }
1240 
1241 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
1242 {
1243 	struct sock *sk1u = NULL;
1244 	struct sock *sk0 = NULL;
1245 
1246 	if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
1247 		return -EINVAL;
1248 
1249 	if (data[IFLA_GTP_FD0]) {
1250 		u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
1251 
1252 		sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
1253 		if (IS_ERR(sk0))
1254 			return PTR_ERR(sk0);
1255 	}
1256 
1257 	if (data[IFLA_GTP_FD1]) {
1258 		u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
1259 
1260 		sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
1261 		if (IS_ERR(sk1u)) {
1262 			gtp_encap_disable_sock(sk0);
1263 			return PTR_ERR(sk1u);
1264 		}
1265 	}
1266 
1267 	gtp->sk0 = sk0;
1268 	gtp->sk1u = sk1u;
1269 
1270 	return 0;
1271 }
1272 
1273 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
1274 {
1275 	struct gtp_dev *gtp = NULL;
1276 	struct net_device *dev;
1277 	struct net *net;
1278 
1279 	/* Examine the link attributes and figure out which network namespace
1280 	 * we are talking about.
1281 	 */
1282 	if (nla[GTPA_NET_NS_FD])
1283 		net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
1284 	else
1285 		net = get_net(src_net);
1286 
1287 	if (IS_ERR(net))
1288 		return NULL;
1289 
1290 	/* Check if there's an existing gtpX device to configure */
1291 	dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
1292 	if (dev && dev->netdev_ops == &gtp_netdev_ops)
1293 		gtp = netdev_priv(dev);
1294 
1295 	put_net(net);
1296 	return gtp;
1297 }
1298 
1299 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1300 {
1301 	pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1302 	pctx->af = AF_INET;
1303 	pctx->peer_addr_ip4.s_addr =
1304 		nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1305 	pctx->ms_addr_ip4.s_addr =
1306 		nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1307 
1308 	switch (pctx->gtp_version) {
1309 	case GTP_V0:
1310 		/* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
1311 		 * label needs to be the same for uplink and downlink packets,
1312 		 * so let's annotate this.
1313 		 */
1314 		pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
1315 		pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
1316 		break;
1317 	case GTP_V1:
1318 		pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
1319 		pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
1320 		break;
1321 	default:
1322 		break;
1323 	}
1324 }
1325 
1326 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
1327 				   struct genl_info *info)
1328 {
1329 	struct pdp_ctx *pctx, *pctx_tid = NULL;
1330 	struct net_device *dev = gtp->dev;
1331 	u32 hash_ms, hash_tid = 0;
1332 	unsigned int version;
1333 	bool found = false;
1334 	__be32 ms_addr;
1335 
1336 	ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1337 	hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
1338 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1339 
1340 	pctx = ipv4_pdp_find(gtp, ms_addr);
1341 	if (pctx)
1342 		found = true;
1343 	if (version == GTP_V0)
1344 		pctx_tid = gtp0_pdp_find(gtp,
1345 					 nla_get_u64(info->attrs[GTPA_TID]));
1346 	else if (version == GTP_V1)
1347 		pctx_tid = gtp1_pdp_find(gtp,
1348 					 nla_get_u32(info->attrs[GTPA_I_TEI]));
1349 	if (pctx_tid)
1350 		found = true;
1351 
1352 	if (found) {
1353 		if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
1354 			return ERR_PTR(-EEXIST);
1355 		if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
1356 			return ERR_PTR(-EOPNOTSUPP);
1357 
1358 		if (pctx && pctx_tid)
1359 			return ERR_PTR(-EEXIST);
1360 		if (!pctx)
1361 			pctx = pctx_tid;
1362 
1363 		ipv4_pdp_fill(pctx, info);
1364 
1365 		if (pctx->gtp_version == GTP_V0)
1366 			netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
1367 				   pctx->u.v0.tid, pctx);
1368 		else if (pctx->gtp_version == GTP_V1)
1369 			netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
1370 				   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1371 
1372 		return pctx;
1373 
1374 	}
1375 
1376 	pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
1377 	if (pctx == NULL)
1378 		return ERR_PTR(-ENOMEM);
1379 
1380 	sock_hold(sk);
1381 	pctx->sk = sk;
1382 	pctx->dev = gtp->dev;
1383 	ipv4_pdp_fill(pctx, info);
1384 	atomic_set(&pctx->tx_seq, 0);
1385 
1386 	switch (pctx->gtp_version) {
1387 	case GTP_V0:
1388 		/* TS 09.60: "The flow label identifies unambiguously a GTP
1389 		 * flow.". We use the tid for this instead, I cannot find a
1390 		 * situation in which this doesn't unambiguosly identify the
1391 		 * PDP context.
1392 		 */
1393 		hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1394 		break;
1395 	case GTP_V1:
1396 		hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1397 		break;
1398 	}
1399 
1400 	hlist_add_head_rcu(&pctx->hlist_addr, &gtp->addr_hash[hash_ms]);
1401 	hlist_add_head_rcu(&pctx->hlist_tid, &gtp->tid_hash[hash_tid]);
1402 
1403 	switch (pctx->gtp_version) {
1404 	case GTP_V0:
1405 		netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1406 			   pctx->u.v0.tid, &pctx->peer_addr_ip4,
1407 			   &pctx->ms_addr_ip4, pctx);
1408 		break;
1409 	case GTP_V1:
1410 		netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1411 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1412 			   &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1413 		break;
1414 	}
1415 
1416 	return pctx;
1417 }
1418 
1419 static void pdp_context_free(struct rcu_head *head)
1420 {
1421 	struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1422 
1423 	sock_put(pctx->sk);
1424 	kfree(pctx);
1425 }
1426 
1427 static void pdp_context_delete(struct pdp_ctx *pctx)
1428 {
1429 	hlist_del_rcu(&pctx->hlist_tid);
1430 	hlist_del_rcu(&pctx->hlist_addr);
1431 	call_rcu(&pctx->rcu_head, pdp_context_free);
1432 }
1433 
1434 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1435 
1436 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1437 {
1438 	unsigned int version;
1439 	struct pdp_ctx *pctx;
1440 	struct gtp_dev *gtp;
1441 	struct sock *sk;
1442 	int err;
1443 
1444 	if (!info->attrs[GTPA_VERSION] ||
1445 	    !info->attrs[GTPA_LINK] ||
1446 	    !info->attrs[GTPA_PEER_ADDRESS] ||
1447 	    !info->attrs[GTPA_MS_ADDRESS])
1448 		return -EINVAL;
1449 
1450 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1451 
1452 	switch (version) {
1453 	case GTP_V0:
1454 		if (!info->attrs[GTPA_TID] ||
1455 		    !info->attrs[GTPA_FLOW])
1456 			return -EINVAL;
1457 		break;
1458 	case GTP_V1:
1459 		if (!info->attrs[GTPA_I_TEI] ||
1460 		    !info->attrs[GTPA_O_TEI])
1461 			return -EINVAL;
1462 		break;
1463 
1464 	default:
1465 		return -EINVAL;
1466 	}
1467 
1468 	rtnl_lock();
1469 
1470 	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1471 	if (!gtp) {
1472 		err = -ENODEV;
1473 		goto out_unlock;
1474 	}
1475 
1476 	if (version == GTP_V0)
1477 		sk = gtp->sk0;
1478 	else if (version == GTP_V1)
1479 		sk = gtp->sk1u;
1480 	else
1481 		sk = NULL;
1482 
1483 	if (!sk) {
1484 		err = -ENODEV;
1485 		goto out_unlock;
1486 	}
1487 
1488 	pctx = gtp_pdp_add(gtp, sk, info);
1489 	if (IS_ERR(pctx)) {
1490 		err = PTR_ERR(pctx);
1491 	} else {
1492 		gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1493 		err = 0;
1494 	}
1495 
1496 out_unlock:
1497 	rtnl_unlock();
1498 	return err;
1499 }
1500 
1501 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1502 					    struct nlattr *nla[])
1503 {
1504 	struct gtp_dev *gtp;
1505 
1506 	gtp = gtp_find_dev(net, nla);
1507 	if (!gtp)
1508 		return ERR_PTR(-ENODEV);
1509 
1510 	if (nla[GTPA_MS_ADDRESS]) {
1511 		__be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1512 
1513 		return ipv4_pdp_find(gtp, ip);
1514 	} else if (nla[GTPA_VERSION]) {
1515 		u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1516 
1517 		if (gtp_version == GTP_V0 && nla[GTPA_TID])
1518 			return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1519 		else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1520 			return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1521 	}
1522 
1523 	return ERR_PTR(-EINVAL);
1524 }
1525 
1526 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1527 {
1528 	struct pdp_ctx *pctx;
1529 
1530 	if (nla[GTPA_LINK])
1531 		pctx = gtp_find_pdp_by_link(net, nla);
1532 	else
1533 		pctx = ERR_PTR(-EINVAL);
1534 
1535 	if (!pctx)
1536 		pctx = ERR_PTR(-ENOENT);
1537 
1538 	return pctx;
1539 }
1540 
1541 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1542 {
1543 	struct pdp_ctx *pctx;
1544 	int err = 0;
1545 
1546 	if (!info->attrs[GTPA_VERSION])
1547 		return -EINVAL;
1548 
1549 	rcu_read_lock();
1550 
1551 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1552 	if (IS_ERR(pctx)) {
1553 		err = PTR_ERR(pctx);
1554 		goto out_unlock;
1555 	}
1556 
1557 	if (pctx->gtp_version == GTP_V0)
1558 		netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1559 			   pctx->u.v0.tid, pctx);
1560 	else if (pctx->gtp_version == GTP_V1)
1561 		netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1562 			   pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1563 
1564 	gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1565 	pdp_context_delete(pctx);
1566 
1567 out_unlock:
1568 	rcu_read_unlock();
1569 	return err;
1570 }
1571 
1572 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1573 			      int flags, u32 type, struct pdp_ctx *pctx)
1574 {
1575 	void *genlh;
1576 
1577 	genlh = genlmsg_put(skb, snd_portid, snd_seq, &gtp_genl_family, flags,
1578 			    type);
1579 	if (genlh == NULL)
1580 		goto nlmsg_failure;
1581 
1582 	if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1583 	    nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1584 	    nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1585 	    nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1586 		goto nla_put_failure;
1587 
1588 	switch (pctx->gtp_version) {
1589 	case GTP_V0:
1590 		if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1591 		    nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1592 			goto nla_put_failure;
1593 		break;
1594 	case GTP_V1:
1595 		if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1596 		    nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1597 			goto nla_put_failure;
1598 		break;
1599 	}
1600 	genlmsg_end(skb, genlh);
1601 	return 0;
1602 
1603 nlmsg_failure:
1604 nla_put_failure:
1605 	genlmsg_cancel(skb, genlh);
1606 	return -EMSGSIZE;
1607 }
1608 
1609 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1610 {
1611 	struct sk_buff *msg;
1612 	int ret;
1613 
1614 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1615 	if (!msg)
1616 		return -ENOMEM;
1617 
1618 	ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1619 	if (ret < 0) {
1620 		nlmsg_free(msg);
1621 		return ret;
1622 	}
1623 
1624 	ret = genlmsg_multicast_netns(&gtp_genl_family, dev_net(pctx->dev), msg,
1625 				      0, GTP_GENL_MCGRP, GFP_ATOMIC);
1626 	return ret;
1627 }
1628 
1629 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1630 {
1631 	struct pdp_ctx *pctx = NULL;
1632 	struct sk_buff *skb2;
1633 	int err;
1634 
1635 	if (!info->attrs[GTPA_VERSION])
1636 		return -EINVAL;
1637 
1638 	rcu_read_lock();
1639 
1640 	pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1641 	if (IS_ERR(pctx)) {
1642 		err = PTR_ERR(pctx);
1643 		goto err_unlock;
1644 	}
1645 
1646 	skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1647 	if (skb2 == NULL) {
1648 		err = -ENOMEM;
1649 		goto err_unlock;
1650 	}
1651 
1652 	err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1653 				 0, info->nlhdr->nlmsg_type, pctx);
1654 	if (err < 0)
1655 		goto err_unlock_free;
1656 
1657 	rcu_read_unlock();
1658 	return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1659 
1660 err_unlock_free:
1661 	kfree_skb(skb2);
1662 err_unlock:
1663 	rcu_read_unlock();
1664 	return err;
1665 }
1666 
1667 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1668 				struct netlink_callback *cb)
1669 {
1670 	struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1671 	int i, j, bucket = cb->args[0], skip = cb->args[1];
1672 	struct net *net = sock_net(skb->sk);
1673 	struct pdp_ctx *pctx;
1674 	struct gtp_net *gn;
1675 
1676 	gn = net_generic(net, gtp_net_id);
1677 
1678 	if (cb->args[4])
1679 		return 0;
1680 
1681 	rcu_read_lock();
1682 	list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1683 		if (last_gtp && last_gtp != gtp)
1684 			continue;
1685 		else
1686 			last_gtp = NULL;
1687 
1688 		for (i = bucket; i < gtp->hash_size; i++) {
1689 			j = 0;
1690 			hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
1691 						 hlist_tid) {
1692 				if (j >= skip &&
1693 				    gtp_genl_fill_info(skb,
1694 					    NETLINK_CB(cb->skb).portid,
1695 					    cb->nlh->nlmsg_seq,
1696 					    NLM_F_MULTI,
1697 					    cb->nlh->nlmsg_type, pctx)) {
1698 					cb->args[0] = i;
1699 					cb->args[1] = j;
1700 					cb->args[2] = (unsigned long)gtp;
1701 					goto out;
1702 				}
1703 				j++;
1704 			}
1705 			skip = 0;
1706 		}
1707 		bucket = 0;
1708 	}
1709 	cb->args[4] = 1;
1710 out:
1711 	rcu_read_unlock();
1712 	return skb->len;
1713 }
1714 
1715 static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
1716 {
1717 	struct sk_buff *skb_to_send;
1718 	__be32 src_ip, dst_ip;
1719 	unsigned int version;
1720 	struct gtp_dev *gtp;
1721 	struct flowi4 fl4;
1722 	struct rtable *rt;
1723 	struct sock *sk;
1724 	__be16 port;
1725 	int len;
1726 
1727 	if (!info->attrs[GTPA_VERSION] ||
1728 	    !info->attrs[GTPA_LINK] ||
1729 	    !info->attrs[GTPA_PEER_ADDRESS] ||
1730 	    !info->attrs[GTPA_MS_ADDRESS])
1731 		return -EINVAL;
1732 
1733 	version = nla_get_u32(info->attrs[GTPA_VERSION]);
1734 	dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1735 	src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1736 
1737 	gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1738 	if (!gtp)
1739 		return -ENODEV;
1740 
1741 	if (!gtp->sk_created)
1742 		return -EOPNOTSUPP;
1743 	if (!(gtp->dev->flags & IFF_UP))
1744 		return -ENETDOWN;
1745 
1746 	if (version == GTP_V0) {
1747 		struct gtp0_header *gtp0_h;
1748 
1749 		len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
1750 			sizeof(struct iphdr) + sizeof(struct udphdr);
1751 
1752 		skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1753 		if (!skb_to_send)
1754 			return -ENOMEM;
1755 
1756 		sk = gtp->sk0;
1757 		port = htons(GTP0_PORT);
1758 
1759 		gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
1760 		memset(gtp0_h, 0, sizeof(struct gtp0_header));
1761 		gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
1762 	} else if (version == GTP_V1) {
1763 		struct gtp1_header_long *gtp1u_h;
1764 
1765 		len = LL_RESERVED_SPACE(gtp->dev) +
1766 			sizeof(struct gtp1_header_long) +
1767 			sizeof(struct iphdr) + sizeof(struct udphdr);
1768 
1769 		skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1770 		if (!skb_to_send)
1771 			return -ENOMEM;
1772 
1773 		sk = gtp->sk1u;
1774 		port = htons(GTP1U_PORT);
1775 
1776 		gtp1u_h = skb_push(skb_to_send,
1777 				   sizeof(struct gtp1_header_long));
1778 		memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
1779 		gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
1780 	} else {
1781 		return -ENODEV;
1782 	}
1783 
1784 	rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
1785 	if (IS_ERR(rt)) {
1786 		netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
1787 			   &dst_ip);
1788 		kfree_skb(skb_to_send);
1789 		return -ENODEV;
1790 	}
1791 
1792 	udp_tunnel_xmit_skb(rt, sk, skb_to_send,
1793 			    fl4.saddr, fl4.daddr,
1794 			    fl4.flowi4_tos,
1795 			    ip4_dst_hoplimit(&rt->dst),
1796 			    0,
1797 			    port, port,
1798 			    !net_eq(sock_net(sk),
1799 				    dev_net(gtp->dev)),
1800 			    false);
1801 	return 0;
1802 }
1803 
1804 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1805 	[GTPA_LINK]		= { .type = NLA_U32, },
1806 	[GTPA_VERSION]		= { .type = NLA_U32, },
1807 	[GTPA_TID]		= { .type = NLA_U64, },
1808 	[GTPA_PEER_ADDRESS]	= { .type = NLA_U32, },
1809 	[GTPA_MS_ADDRESS]	= { .type = NLA_U32, },
1810 	[GTPA_FLOW]		= { .type = NLA_U16, },
1811 	[GTPA_NET_NS_FD]	= { .type = NLA_U32, },
1812 	[GTPA_I_TEI]		= { .type = NLA_U32, },
1813 	[GTPA_O_TEI]		= { .type = NLA_U32, },
1814 };
1815 
1816 static const struct genl_small_ops gtp_genl_ops[] = {
1817 	{
1818 		.cmd = GTP_CMD_NEWPDP,
1819 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1820 		.doit = gtp_genl_new_pdp,
1821 		.flags = GENL_ADMIN_PERM,
1822 	},
1823 	{
1824 		.cmd = GTP_CMD_DELPDP,
1825 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1826 		.doit = gtp_genl_del_pdp,
1827 		.flags = GENL_ADMIN_PERM,
1828 	},
1829 	{
1830 		.cmd = GTP_CMD_GETPDP,
1831 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1832 		.doit = gtp_genl_get_pdp,
1833 		.dumpit = gtp_genl_dump_pdp,
1834 		.flags = GENL_ADMIN_PERM,
1835 	},
1836 	{
1837 		.cmd = GTP_CMD_ECHOREQ,
1838 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1839 		.doit = gtp_genl_send_echo_req,
1840 		.flags = GENL_ADMIN_PERM,
1841 	},
1842 };
1843 
1844 static struct genl_family gtp_genl_family __ro_after_init = {
1845 	.name		= "gtp",
1846 	.version	= 0,
1847 	.hdrsize	= 0,
1848 	.maxattr	= GTPA_MAX,
1849 	.policy = gtp_genl_policy,
1850 	.netnsok	= true,
1851 	.module		= THIS_MODULE,
1852 	.small_ops	= gtp_genl_ops,
1853 	.n_small_ops	= ARRAY_SIZE(gtp_genl_ops),
1854 	.resv_start_op	= GTP_CMD_ECHOREQ + 1,
1855 	.mcgrps		= gtp_genl_mcgrps,
1856 	.n_mcgrps	= ARRAY_SIZE(gtp_genl_mcgrps),
1857 };
1858 
1859 static int __net_init gtp_net_init(struct net *net)
1860 {
1861 	struct gtp_net *gn = net_generic(net, gtp_net_id);
1862 
1863 	INIT_LIST_HEAD(&gn->gtp_dev_list);
1864 	return 0;
1865 }
1866 
1867 static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list,
1868 					       struct list_head *dev_to_kill)
1869 {
1870 	struct net *net;
1871 
1872 	list_for_each_entry(net, net_list, exit_list) {
1873 		struct gtp_net *gn = net_generic(net, gtp_net_id);
1874 		struct gtp_dev *gtp;
1875 
1876 		list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1877 			gtp_dellink(gtp->dev, dev_to_kill);
1878 	}
1879 }
1880 
1881 static struct pernet_operations gtp_net_ops = {
1882 	.init	= gtp_net_init,
1883 	.exit_batch_rtnl = gtp_net_exit_batch_rtnl,
1884 	.id	= &gtp_net_id,
1885 	.size	= sizeof(struct gtp_net),
1886 };
1887 
1888 static int __init gtp_init(void)
1889 {
1890 	int err;
1891 
1892 	get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
1893 
1894 	err = register_pernet_subsys(&gtp_net_ops);
1895 	if (err < 0)
1896 		goto error_out;
1897 
1898 	err = rtnl_link_register(&gtp_link_ops);
1899 	if (err < 0)
1900 		goto unreg_pernet_subsys;
1901 
1902 	err = genl_register_family(&gtp_genl_family);
1903 	if (err < 0)
1904 		goto unreg_rtnl_link;
1905 
1906 	pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1907 		sizeof(struct pdp_ctx));
1908 	return 0;
1909 
1910 unreg_rtnl_link:
1911 	rtnl_link_unregister(&gtp_link_ops);
1912 unreg_pernet_subsys:
1913 	unregister_pernet_subsys(&gtp_net_ops);
1914 error_out:
1915 	pr_err("error loading GTP module loaded\n");
1916 	return err;
1917 }
1918 late_initcall(gtp_init);
1919 
1920 static void __exit gtp_fini(void)
1921 {
1922 	genl_unregister_family(&gtp_genl_family);
1923 	rtnl_link_unregister(&gtp_link_ops);
1924 	unregister_pernet_subsys(&gtp_net_ops);
1925 
1926 	pr_info("GTP module unloaded\n");
1927 }
1928 module_exit(gtp_fini);
1929 
1930 MODULE_LICENSE("GPL");
1931 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1932 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1933 MODULE_ALIAS_RTNL_LINK("gtp");
1934 MODULE_ALIAS_GENL_FAMILY("gtp");
1935