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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. */
36struct 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. */
64struct 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
82struct echo_info {
83 struct in_addr ms_addr_ip4;
84 struct in_addr peer_addr_ip4;
85 u8 gtp_version;
86};
87
88static unsigned int gtp_net_id __read_mostly;
89
90struct gtp_net {
91 struct list_head gtp_dev_list;
92};
93
94static u32 gtp_h_initval;
95
96static struct genl_family gtp_genl_family;
97
98enum gtp_multicast_groups {
99 GTP_GENL_MCGRP,
100};
101
102static const struct genl_multicast_group gtp_genl_mcgrps[] = {
103 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
104};
105
106static void pdp_context_delete(struct pdp_ctx *pctx);
107
108static 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
114static inline u32 gtp1u_hashfn(u32 tid)
115{
116 return jhash_1word(tid, gtp_h_initval);
117}
118
119static 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. */
125static 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 = >p->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. */
141static 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 = >p->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. */
157static 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 = >p->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
173static 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 */
192static 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
202static 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
233err:
234 pctx->dev->stats.rx_dropped++;
235 return -1;
236}
237
238static 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 */
263static 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 */
270static 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
295static 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(>p_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
352static 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, >p_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
370failure:
371 genlmsg_cancel(skb, genlh);
372 return -EMSGSIZE;
373}
374
375static 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(>p_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. */
408static 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 */
446static 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
475static 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(>p_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
534static 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(>p_genl_family, dev_net(gtp->dev),
567 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
568}
569
570static 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
622static 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
642static void gtp_encap_destroy(struct sock *sk)
643{
644 rtnl_lock();
645 __gtp_encap_destroy(sk);
646 rtnl_unlock();
647}
648
649static void gtp_encap_disable_sock(struct sock *sk)
650{
651 if (!sk)
652 return;
653
654 __gtp_encap_destroy(sk);
655}
656
657static 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 */
674static 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
714static int gtp_dev_init(struct net_device *dev)
715{
716 struct gtp_dev *gtp = netdev_priv(dev);
717
718 gtp->dev = dev;
719
720 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
721 if (!dev->tstats)
722 return -ENOMEM;
723
724 return 0;
725}
726
727static void gtp_dev_uninit(struct net_device *dev)
728{
729 struct gtp_dev *gtp = netdev_priv(dev);
730
731 gtp_encap_disable(gtp);
732 free_percpu(dev->tstats);
733}
734
735static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
736{
737 int payload_len = skb->len;
738 struct gtp0_header *gtp0;
739
740 gtp0 = skb_push(skb, sizeof(*gtp0));
741
742 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
743 gtp0->type = GTP_TPDU;
744 gtp0->length = htons(payload_len);
745 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
746 gtp0->flow = htons(pctx->u.v0.flow);
747 gtp0->number = 0xff;
748 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
749 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
750}
751
752static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
753{
754 int payload_len = skb->len;
755 struct gtp1_header *gtp1;
756
757 gtp1 = skb_push(skb, sizeof(*gtp1));
758
759 /* Bits 8 7 6 5 4 3 2 1
760 * +--+--+--+--+--+--+--+--+
761 * |version |PT| 0| E| S|PN|
762 * +--+--+--+--+--+--+--+--+
763 * 0 0 1 1 1 0 0 0
764 */
765 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
766 gtp1->type = GTP_TPDU;
767 gtp1->length = htons(payload_len);
768 gtp1->tid = htonl(pctx->u.v1.o_tei);
769
770 /* TODO: Support for extension header, sequence number and N-PDU.
771 * Update the length field if any of them is available.
772 */
773}
774
775struct gtp_pktinfo {
776 struct sock *sk;
777 struct iphdr *iph;
778 struct flowi4 fl4;
779 struct rtable *rt;
780 struct pdp_ctx *pctx;
781 struct net_device *dev;
782 __be16 gtph_port;
783};
784
785static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
786{
787 switch (pktinfo->pctx->gtp_version) {
788 case GTP_V0:
789 pktinfo->gtph_port = htons(GTP0_PORT);
790 gtp0_push_header(skb, pktinfo->pctx);
791 break;
792 case GTP_V1:
793 pktinfo->gtph_port = htons(GTP1U_PORT);
794 gtp1_push_header(skb, pktinfo->pctx);
795 break;
796 }
797}
798
799static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
800 struct sock *sk, struct iphdr *iph,
801 struct pdp_ctx *pctx, struct rtable *rt,
802 struct flowi4 *fl4,
803 struct net_device *dev)
804{
805 pktinfo->sk = sk;
806 pktinfo->iph = iph;
807 pktinfo->pctx = pctx;
808 pktinfo->rt = rt;
809 pktinfo->fl4 = *fl4;
810 pktinfo->dev = dev;
811}
812
813static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
814 struct gtp_pktinfo *pktinfo)
815{
816 struct gtp_dev *gtp = netdev_priv(dev);
817 struct pdp_ctx *pctx;
818 struct rtable *rt;
819 struct flowi4 fl4;
820 struct iphdr *iph;
821 __be16 df;
822 int mtu;
823
824 /* Read the IP destination address and resolve the PDP context.
825 * Prepend PDP header with TEI/TID from PDP ctx.
826 */
827 iph = ip_hdr(skb);
828 if (gtp->role == GTP_ROLE_SGSN)
829 pctx = ipv4_pdp_find(gtp, iph->saddr);
830 else
831 pctx = ipv4_pdp_find(gtp, iph->daddr);
832
833 if (!pctx) {
834 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
835 &iph->daddr);
836 return -ENOENT;
837 }
838 netdev_dbg(dev, "found PDP context %p\n", pctx);
839
840 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr,
841 inet_sk(pctx->sk)->inet_saddr);
842 if (IS_ERR(rt)) {
843 netdev_dbg(dev, "no route to SSGN %pI4\n",
844 &pctx->peer_addr_ip4.s_addr);
845 dev->stats.tx_carrier_errors++;
846 goto err;
847 }
848
849 if (rt->dst.dev == dev) {
850 netdev_dbg(dev, "circular route to SSGN %pI4\n",
851 &pctx->peer_addr_ip4.s_addr);
852 dev->stats.collisions++;
853 goto err_rt;
854 }
855
856 /* This is similar to tnl_update_pmtu(). */
857 df = iph->frag_off;
858 if (df) {
859 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
860 sizeof(struct iphdr) - sizeof(struct udphdr);
861 switch (pctx->gtp_version) {
862 case GTP_V0:
863 mtu -= sizeof(struct gtp0_header);
864 break;
865 case GTP_V1:
866 mtu -= sizeof(struct gtp1_header);
867 break;
868 }
869 } else {
870 mtu = dst_mtu(&rt->dst);
871 }
872
873 skb_dst_update_pmtu_no_confirm(skb, mtu);
874
875 if (iph->frag_off & htons(IP_DF) &&
876 ((!skb_is_gso(skb) && skb->len > mtu) ||
877 (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
878 netdev_dbg(dev, "packet too big, fragmentation needed\n");
879 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
880 htonl(mtu));
881 goto err_rt;
882 }
883
884 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
885 gtp_push_header(skb, pktinfo);
886
887 return 0;
888err_rt:
889 ip_rt_put(rt);
890err:
891 return -EBADMSG;
892}
893
894static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
895{
896 unsigned int proto = ntohs(skb->protocol);
897 struct gtp_pktinfo pktinfo;
898 int err;
899
900 /* Ensure there is sufficient headroom. */
901 if (skb_cow_head(skb, dev->needed_headroom))
902 goto tx_err;
903
904 skb_reset_inner_headers(skb);
905
906 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
907 rcu_read_lock();
908 switch (proto) {
909 case ETH_P_IP:
910 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
911 break;
912 default:
913 err = -EOPNOTSUPP;
914 break;
915 }
916 rcu_read_unlock();
917
918 if (err < 0)
919 goto tx_err;
920
921 switch (proto) {
922 case ETH_P_IP:
923 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
924 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
925 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
926 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
927 pktinfo.iph->tos,
928 ip4_dst_hoplimit(&pktinfo.rt->dst),
929 0,
930 pktinfo.gtph_port, pktinfo.gtph_port,
931 !net_eq(sock_net(pktinfo.pctx->sk),
932 dev_net(dev)),
933 false);
934 break;
935 }
936
937 return NETDEV_TX_OK;
938tx_err:
939 dev->stats.tx_errors++;
940 dev_kfree_skb(skb);
941 return NETDEV_TX_OK;
942}
943
944static const struct net_device_ops gtp_netdev_ops = {
945 .ndo_init = gtp_dev_init,
946 .ndo_uninit = gtp_dev_uninit,
947 .ndo_start_xmit = gtp_dev_xmit,
948 .ndo_get_stats64 = dev_get_tstats64,
949};
950
951static const struct device_type gtp_type = {
952 .name = "gtp",
953};
954
955static void gtp_link_setup(struct net_device *dev)
956{
957 unsigned int max_gtp_header_len = sizeof(struct iphdr) +
958 sizeof(struct udphdr) +
959 sizeof(struct gtp0_header);
960
961 dev->netdev_ops = >p_netdev_ops;
962 dev->needs_free_netdev = true;
963 SET_NETDEV_DEVTYPE(dev, >p_type);
964
965 dev->hard_header_len = 0;
966 dev->addr_len = 0;
967 dev->mtu = ETH_DATA_LEN - max_gtp_header_len;
968
969 /* Zero header length. */
970 dev->type = ARPHRD_NONE;
971 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
972
973 dev->priv_flags |= IFF_NO_QUEUE;
974 dev->features |= NETIF_F_LLTX;
975 netif_keep_dst(dev);
976
977 dev->needed_headroom = LL_MAX_HEADER + max_gtp_header_len;
978}
979
980static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
981static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
982
983static void gtp_destructor(struct net_device *dev)
984{
985 struct gtp_dev *gtp = netdev_priv(dev);
986
987 kfree(gtp->addr_hash);
988 kfree(gtp->tid_hash);
989}
990
991static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp)
992{
993 struct udp_tunnel_sock_cfg tuncfg = {};
994 struct udp_port_cfg udp_conf = {
995 .local_ip.s_addr = htonl(INADDR_ANY),
996 .family = AF_INET,
997 };
998 struct net *net = gtp->net;
999 struct socket *sock;
1000 int err;
1001
1002 if (type == UDP_ENCAP_GTP0)
1003 udp_conf.local_udp_port = htons(GTP0_PORT);
1004 else if (type == UDP_ENCAP_GTP1U)
1005 udp_conf.local_udp_port = htons(GTP1U_PORT);
1006 else
1007 return ERR_PTR(-EINVAL);
1008
1009 err = udp_sock_create(net, &udp_conf, &sock);
1010 if (err)
1011 return ERR_PTR(err);
1012
1013 tuncfg.sk_user_data = gtp;
1014 tuncfg.encap_type = type;
1015 tuncfg.encap_rcv = gtp_encap_recv;
1016 tuncfg.encap_destroy = NULL;
1017
1018 setup_udp_tunnel_sock(net, sock, &tuncfg);
1019
1020 return sock->sk;
1021}
1022
1023static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[])
1024{
1025 struct sock *sk1u = NULL;
1026 struct sock *sk0 = NULL;
1027
1028 sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp);
1029 if (IS_ERR(sk0))
1030 return PTR_ERR(sk0);
1031
1032 sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp);
1033 if (IS_ERR(sk1u)) {
1034 udp_tunnel_sock_release(sk0->sk_socket);
1035 return PTR_ERR(sk1u);
1036 }
1037
1038 gtp->sk_created = true;
1039 gtp->sk0 = sk0;
1040 gtp->sk1u = sk1u;
1041
1042 return 0;
1043}
1044
1045static int gtp_newlink(struct net *src_net, struct net_device *dev,
1046 struct nlattr *tb[], struct nlattr *data[],
1047 struct netlink_ext_ack *extack)
1048{
1049 unsigned int role = GTP_ROLE_GGSN;
1050 struct gtp_dev *gtp;
1051 struct gtp_net *gn;
1052 int hashsize, err;
1053
1054 gtp = netdev_priv(dev);
1055
1056 if (!data[IFLA_GTP_PDP_HASHSIZE]) {
1057 hashsize = 1024;
1058 } else {
1059 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
1060 if (!hashsize)
1061 hashsize = 1024;
1062 }
1063
1064 if (data[IFLA_GTP_ROLE]) {
1065 role = nla_get_u32(data[IFLA_GTP_ROLE]);
1066 if (role > GTP_ROLE_SGSN)
1067 return -EINVAL;
1068 }
1069 gtp->role = role;
1070
1071 if (!data[IFLA_GTP_RESTART_COUNT])
1072 gtp->restart_count = 0;
1073 else
1074 gtp->restart_count = nla_get_u8(data[IFLA_GTP_RESTART_COUNT]);
1075
1076 gtp->net = src_net;
1077
1078 err = gtp_hashtable_new(gtp, hashsize);
1079 if (err < 0)
1080 return err;
1081
1082 if (data[IFLA_GTP_CREATE_SOCKETS])
1083 err = gtp_create_sockets(gtp, data);
1084 else
1085 err = gtp_encap_enable(gtp, data);
1086 if (err < 0)
1087 goto out_hashtable;
1088
1089 err = register_netdevice(dev);
1090 if (err < 0) {
1091 netdev_dbg(dev, "failed to register new netdev %d\n", err);
1092 goto out_encap;
1093 }
1094
1095 gn = net_generic(dev_net(dev), gtp_net_id);
1096 list_add_rcu(>p->list, &gn->gtp_dev_list);
1097 dev->priv_destructor = gtp_destructor;
1098
1099 netdev_dbg(dev, "registered new GTP interface\n");
1100
1101 return 0;
1102
1103out_encap:
1104 gtp_encap_disable(gtp);
1105out_hashtable:
1106 kfree(gtp->addr_hash);
1107 kfree(gtp->tid_hash);
1108 return err;
1109}
1110
1111static void gtp_dellink(struct net_device *dev, struct list_head *head)
1112{
1113 struct gtp_dev *gtp = netdev_priv(dev);
1114 struct pdp_ctx *pctx;
1115 int i;
1116
1117 for (i = 0; i < gtp->hash_size; i++)
1118 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
1119 pdp_context_delete(pctx);
1120
1121 list_del_rcu(>p->list);
1122 unregister_netdevice_queue(dev, head);
1123}
1124
1125static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
1126 [IFLA_GTP_FD0] = { .type = NLA_U32 },
1127 [IFLA_GTP_FD1] = { .type = NLA_U32 },
1128 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
1129 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
1130 [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 },
1131 [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 },
1132};
1133
1134static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
1135 struct netlink_ext_ack *extack)
1136{
1137 if (!data)
1138 return -EINVAL;
1139
1140 return 0;
1141}
1142
1143static size_t gtp_get_size(const struct net_device *dev)
1144{
1145 return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
1146 nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
1147 nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
1148}
1149
1150static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
1151{
1152 struct gtp_dev *gtp = netdev_priv(dev);
1153
1154 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
1155 goto nla_put_failure;
1156 if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
1157 goto nla_put_failure;
1158 if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
1159 goto nla_put_failure;
1160
1161 return 0;
1162
1163nla_put_failure:
1164 return -EMSGSIZE;
1165}
1166
1167static struct rtnl_link_ops gtp_link_ops __read_mostly = {
1168 .kind = "gtp",
1169 .maxtype = IFLA_GTP_MAX,
1170 .policy = gtp_policy,
1171 .priv_size = sizeof(struct gtp_dev),
1172 .setup = gtp_link_setup,
1173 .validate = gtp_validate,
1174 .newlink = gtp_newlink,
1175 .dellink = gtp_dellink,
1176 .get_size = gtp_get_size,
1177 .fill_info = gtp_fill_info,
1178};
1179
1180static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
1181{
1182 int i;
1183
1184 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1185 GFP_KERNEL | __GFP_NOWARN);
1186 if (gtp->addr_hash == NULL)
1187 return -ENOMEM;
1188
1189 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1190 GFP_KERNEL | __GFP_NOWARN);
1191 if (gtp->tid_hash == NULL)
1192 goto err1;
1193
1194 gtp->hash_size = hsize;
1195
1196 for (i = 0; i < hsize; i++) {
1197 INIT_HLIST_HEAD(>p->addr_hash[i]);
1198 INIT_HLIST_HEAD(>p->tid_hash[i]);
1199 }
1200 return 0;
1201err1:
1202 kfree(gtp->addr_hash);
1203 return -ENOMEM;
1204}
1205
1206static struct sock *gtp_encap_enable_socket(int fd, int type,
1207 struct gtp_dev *gtp)
1208{
1209 struct udp_tunnel_sock_cfg tuncfg = {NULL};
1210 struct socket *sock;
1211 struct sock *sk;
1212 int err;
1213
1214 pr_debug("enable gtp on %d, %d\n", fd, type);
1215
1216 sock = sockfd_lookup(fd, &err);
1217 if (!sock) {
1218 pr_debug("gtp socket fd=%d not found\n", fd);
1219 return NULL;
1220 }
1221
1222 sk = sock->sk;
1223 if (sk->sk_protocol != IPPROTO_UDP ||
1224 sk->sk_type != SOCK_DGRAM ||
1225 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
1226 pr_debug("socket fd=%d not UDP\n", fd);
1227 sk = ERR_PTR(-EINVAL);
1228 goto out_sock;
1229 }
1230
1231 lock_sock(sk);
1232 if (sk->sk_user_data) {
1233 sk = ERR_PTR(-EBUSY);
1234 goto out_rel_sock;
1235 }
1236
1237 sock_hold(sk);
1238
1239 tuncfg.sk_user_data = gtp;
1240 tuncfg.encap_type = type;
1241 tuncfg.encap_rcv = gtp_encap_recv;
1242 tuncfg.encap_destroy = gtp_encap_destroy;
1243
1244 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
1245
1246out_rel_sock:
1247 release_sock(sock->sk);
1248out_sock:
1249 sockfd_put(sock);
1250 return sk;
1251}
1252
1253static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
1254{
1255 struct sock *sk1u = NULL;
1256 struct sock *sk0 = NULL;
1257
1258 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
1259 return -EINVAL;
1260
1261 if (data[IFLA_GTP_FD0]) {
1262 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
1263
1264 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
1265 if (IS_ERR(sk0))
1266 return PTR_ERR(sk0);
1267 }
1268
1269 if (data[IFLA_GTP_FD1]) {
1270 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
1271
1272 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
1273 if (IS_ERR(sk1u)) {
1274 gtp_encap_disable_sock(sk0);
1275 return PTR_ERR(sk1u);
1276 }
1277 }
1278
1279 gtp->sk0 = sk0;
1280 gtp->sk1u = sk1u;
1281
1282 return 0;
1283}
1284
1285static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
1286{
1287 struct gtp_dev *gtp = NULL;
1288 struct net_device *dev;
1289 struct net *net;
1290
1291 /* Examine the link attributes and figure out which network namespace
1292 * we are talking about.
1293 */
1294 if (nla[GTPA_NET_NS_FD])
1295 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
1296 else
1297 net = get_net(src_net);
1298
1299 if (IS_ERR(net))
1300 return NULL;
1301
1302 /* Check if there's an existing gtpX device to configure */
1303 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
1304 if (dev && dev->netdev_ops == >p_netdev_ops)
1305 gtp = netdev_priv(dev);
1306
1307 put_net(net);
1308 return gtp;
1309}
1310
1311static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1312{
1313 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1314 pctx->af = AF_INET;
1315 pctx->peer_addr_ip4.s_addr =
1316 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1317 pctx->ms_addr_ip4.s_addr =
1318 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1319
1320 switch (pctx->gtp_version) {
1321 case GTP_V0:
1322 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
1323 * label needs to be the same for uplink and downlink packets,
1324 * so let's annotate this.
1325 */
1326 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
1327 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
1328 break;
1329 case GTP_V1:
1330 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
1331 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
1332 break;
1333 default:
1334 break;
1335 }
1336}
1337
1338static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
1339 struct genl_info *info)
1340{
1341 struct pdp_ctx *pctx, *pctx_tid = NULL;
1342 struct net_device *dev = gtp->dev;
1343 u32 hash_ms, hash_tid = 0;
1344 unsigned int version;
1345 bool found = false;
1346 __be32 ms_addr;
1347
1348 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1349 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
1350 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1351
1352 pctx = ipv4_pdp_find(gtp, ms_addr);
1353 if (pctx)
1354 found = true;
1355 if (version == GTP_V0)
1356 pctx_tid = gtp0_pdp_find(gtp,
1357 nla_get_u64(info->attrs[GTPA_TID]));
1358 else if (version == GTP_V1)
1359 pctx_tid = gtp1_pdp_find(gtp,
1360 nla_get_u32(info->attrs[GTPA_I_TEI]));
1361 if (pctx_tid)
1362 found = true;
1363
1364 if (found) {
1365 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
1366 return ERR_PTR(-EEXIST);
1367 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
1368 return ERR_PTR(-EOPNOTSUPP);
1369
1370 if (pctx && pctx_tid)
1371 return ERR_PTR(-EEXIST);
1372 if (!pctx)
1373 pctx = pctx_tid;
1374
1375 ipv4_pdp_fill(pctx, info);
1376
1377 if (pctx->gtp_version == GTP_V0)
1378 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
1379 pctx->u.v0.tid, pctx);
1380 else if (pctx->gtp_version == GTP_V1)
1381 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
1382 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1383
1384 return pctx;
1385
1386 }
1387
1388 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
1389 if (pctx == NULL)
1390 return ERR_PTR(-ENOMEM);
1391
1392 sock_hold(sk);
1393 pctx->sk = sk;
1394 pctx->dev = gtp->dev;
1395 ipv4_pdp_fill(pctx, info);
1396 atomic_set(&pctx->tx_seq, 0);
1397
1398 switch (pctx->gtp_version) {
1399 case GTP_V0:
1400 /* TS 09.60: "The flow label identifies unambiguously a GTP
1401 * flow.". We use the tid for this instead, I cannot find a
1402 * situation in which this doesn't unambiguosly identify the
1403 * PDP context.
1404 */
1405 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1406 break;
1407 case GTP_V1:
1408 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1409 break;
1410 }
1411
1412 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
1413 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1414
1415 switch (pctx->gtp_version) {
1416 case GTP_V0:
1417 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1418 pctx->u.v0.tid, &pctx->peer_addr_ip4,
1419 &pctx->ms_addr_ip4, pctx);
1420 break;
1421 case GTP_V1:
1422 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1423 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1424 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1425 break;
1426 }
1427
1428 return pctx;
1429}
1430
1431static void pdp_context_free(struct rcu_head *head)
1432{
1433 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1434
1435 sock_put(pctx->sk);
1436 kfree(pctx);
1437}
1438
1439static void pdp_context_delete(struct pdp_ctx *pctx)
1440{
1441 hlist_del_rcu(&pctx->hlist_tid);
1442 hlist_del_rcu(&pctx->hlist_addr);
1443 call_rcu(&pctx->rcu_head, pdp_context_free);
1444}
1445
1446static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1447
1448static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1449{
1450 unsigned int version;
1451 struct pdp_ctx *pctx;
1452 struct gtp_dev *gtp;
1453 struct sock *sk;
1454 int err;
1455
1456 if (!info->attrs[GTPA_VERSION] ||
1457 !info->attrs[GTPA_LINK] ||
1458 !info->attrs[GTPA_PEER_ADDRESS] ||
1459 !info->attrs[GTPA_MS_ADDRESS])
1460 return -EINVAL;
1461
1462 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1463
1464 switch (version) {
1465 case GTP_V0:
1466 if (!info->attrs[GTPA_TID] ||
1467 !info->attrs[GTPA_FLOW])
1468 return -EINVAL;
1469 break;
1470 case GTP_V1:
1471 if (!info->attrs[GTPA_I_TEI] ||
1472 !info->attrs[GTPA_O_TEI])
1473 return -EINVAL;
1474 break;
1475
1476 default:
1477 return -EINVAL;
1478 }
1479
1480 rtnl_lock();
1481
1482 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1483 if (!gtp) {
1484 err = -ENODEV;
1485 goto out_unlock;
1486 }
1487
1488 if (version == GTP_V0)
1489 sk = gtp->sk0;
1490 else if (version == GTP_V1)
1491 sk = gtp->sk1u;
1492 else
1493 sk = NULL;
1494
1495 if (!sk) {
1496 err = -ENODEV;
1497 goto out_unlock;
1498 }
1499
1500 pctx = gtp_pdp_add(gtp, sk, info);
1501 if (IS_ERR(pctx)) {
1502 err = PTR_ERR(pctx);
1503 } else {
1504 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1505 err = 0;
1506 }
1507
1508out_unlock:
1509 rtnl_unlock();
1510 return err;
1511}
1512
1513static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1514 struct nlattr *nla[])
1515{
1516 struct gtp_dev *gtp;
1517
1518 gtp = gtp_find_dev(net, nla);
1519 if (!gtp)
1520 return ERR_PTR(-ENODEV);
1521
1522 if (nla[GTPA_MS_ADDRESS]) {
1523 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1524
1525 return ipv4_pdp_find(gtp, ip);
1526 } else if (nla[GTPA_VERSION]) {
1527 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1528
1529 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1530 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1531 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1532 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1533 }
1534
1535 return ERR_PTR(-EINVAL);
1536}
1537
1538static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1539{
1540 struct pdp_ctx *pctx;
1541
1542 if (nla[GTPA_LINK])
1543 pctx = gtp_find_pdp_by_link(net, nla);
1544 else
1545 pctx = ERR_PTR(-EINVAL);
1546
1547 if (!pctx)
1548 pctx = ERR_PTR(-ENOENT);
1549
1550 return pctx;
1551}
1552
1553static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1554{
1555 struct pdp_ctx *pctx;
1556 int err = 0;
1557
1558 if (!info->attrs[GTPA_VERSION])
1559 return -EINVAL;
1560
1561 rcu_read_lock();
1562
1563 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1564 if (IS_ERR(pctx)) {
1565 err = PTR_ERR(pctx);
1566 goto out_unlock;
1567 }
1568
1569 if (pctx->gtp_version == GTP_V0)
1570 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1571 pctx->u.v0.tid, pctx);
1572 else if (pctx->gtp_version == GTP_V1)
1573 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1574 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1575
1576 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1577 pdp_context_delete(pctx);
1578
1579out_unlock:
1580 rcu_read_unlock();
1581 return err;
1582}
1583
1584static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1585 int flags, u32 type, struct pdp_ctx *pctx)
1586{
1587 void *genlh;
1588
1589 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
1590 type);
1591 if (genlh == NULL)
1592 goto nlmsg_failure;
1593
1594 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1595 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1596 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1597 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1598 goto nla_put_failure;
1599
1600 switch (pctx->gtp_version) {
1601 case GTP_V0:
1602 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1603 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1604 goto nla_put_failure;
1605 break;
1606 case GTP_V1:
1607 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1608 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1609 goto nla_put_failure;
1610 break;
1611 }
1612 genlmsg_end(skb, genlh);
1613 return 0;
1614
1615nlmsg_failure:
1616nla_put_failure:
1617 genlmsg_cancel(skb, genlh);
1618 return -EMSGSIZE;
1619}
1620
1621static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1622{
1623 struct sk_buff *msg;
1624 int ret;
1625
1626 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1627 if (!msg)
1628 return -ENOMEM;
1629
1630 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1631 if (ret < 0) {
1632 nlmsg_free(msg);
1633 return ret;
1634 }
1635
1636 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg,
1637 0, GTP_GENL_MCGRP, GFP_ATOMIC);
1638 return ret;
1639}
1640
1641static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1642{
1643 struct pdp_ctx *pctx = NULL;
1644 struct sk_buff *skb2;
1645 int err;
1646
1647 if (!info->attrs[GTPA_VERSION])
1648 return -EINVAL;
1649
1650 rcu_read_lock();
1651
1652 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1653 if (IS_ERR(pctx)) {
1654 err = PTR_ERR(pctx);
1655 goto err_unlock;
1656 }
1657
1658 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1659 if (skb2 == NULL) {
1660 err = -ENOMEM;
1661 goto err_unlock;
1662 }
1663
1664 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1665 0, info->nlhdr->nlmsg_type, pctx);
1666 if (err < 0)
1667 goto err_unlock_free;
1668
1669 rcu_read_unlock();
1670 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1671
1672err_unlock_free:
1673 kfree_skb(skb2);
1674err_unlock:
1675 rcu_read_unlock();
1676 return err;
1677}
1678
1679static int gtp_genl_dump_pdp(struct sk_buff *skb,
1680 struct netlink_callback *cb)
1681{
1682 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1683 int i, j, bucket = cb->args[0], skip = cb->args[1];
1684 struct net *net = sock_net(skb->sk);
1685 struct pdp_ctx *pctx;
1686 struct gtp_net *gn;
1687
1688 gn = net_generic(net, gtp_net_id);
1689
1690 if (cb->args[4])
1691 return 0;
1692
1693 rcu_read_lock();
1694 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1695 if (last_gtp && last_gtp != gtp)
1696 continue;
1697 else
1698 last_gtp = NULL;
1699
1700 for (i = bucket; i < gtp->hash_size; i++) {
1701 j = 0;
1702 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
1703 hlist_tid) {
1704 if (j >= skip &&
1705 gtp_genl_fill_info(skb,
1706 NETLINK_CB(cb->skb).portid,
1707 cb->nlh->nlmsg_seq,
1708 NLM_F_MULTI,
1709 cb->nlh->nlmsg_type, pctx)) {
1710 cb->args[0] = i;
1711 cb->args[1] = j;
1712 cb->args[2] = (unsigned long)gtp;
1713 goto out;
1714 }
1715 j++;
1716 }
1717 skip = 0;
1718 }
1719 bucket = 0;
1720 }
1721 cb->args[4] = 1;
1722out:
1723 rcu_read_unlock();
1724 return skb->len;
1725}
1726
1727static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
1728{
1729 struct sk_buff *skb_to_send;
1730 __be32 src_ip, dst_ip;
1731 unsigned int version;
1732 struct gtp_dev *gtp;
1733 struct flowi4 fl4;
1734 struct rtable *rt;
1735 struct sock *sk;
1736 __be16 port;
1737 int len;
1738
1739 if (!info->attrs[GTPA_VERSION] ||
1740 !info->attrs[GTPA_LINK] ||
1741 !info->attrs[GTPA_PEER_ADDRESS] ||
1742 !info->attrs[GTPA_MS_ADDRESS])
1743 return -EINVAL;
1744
1745 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1746 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1747 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1748
1749 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1750 if (!gtp)
1751 return -ENODEV;
1752
1753 if (!gtp->sk_created)
1754 return -EOPNOTSUPP;
1755 if (!(gtp->dev->flags & IFF_UP))
1756 return -ENETDOWN;
1757
1758 if (version == GTP_V0) {
1759 struct gtp0_header *gtp0_h;
1760
1761 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
1762 sizeof(struct iphdr) + sizeof(struct udphdr);
1763
1764 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1765 if (!skb_to_send)
1766 return -ENOMEM;
1767
1768 sk = gtp->sk0;
1769 port = htons(GTP0_PORT);
1770
1771 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
1772 memset(gtp0_h, 0, sizeof(struct gtp0_header));
1773 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
1774 } else if (version == GTP_V1) {
1775 struct gtp1_header_long *gtp1u_h;
1776
1777 len = LL_RESERVED_SPACE(gtp->dev) +
1778 sizeof(struct gtp1_header_long) +
1779 sizeof(struct iphdr) + sizeof(struct udphdr);
1780
1781 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1782 if (!skb_to_send)
1783 return -ENOMEM;
1784
1785 sk = gtp->sk1u;
1786 port = htons(GTP1U_PORT);
1787
1788 gtp1u_h = skb_push(skb_to_send,
1789 sizeof(struct gtp1_header_long));
1790 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
1791 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
1792 } else {
1793 return -ENODEV;
1794 }
1795
1796 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
1797 if (IS_ERR(rt)) {
1798 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
1799 &dst_ip);
1800 kfree_skb(skb_to_send);
1801 return -ENODEV;
1802 }
1803
1804 udp_tunnel_xmit_skb(rt, sk, skb_to_send,
1805 fl4.saddr, fl4.daddr,
1806 fl4.flowi4_tos,
1807 ip4_dst_hoplimit(&rt->dst),
1808 0,
1809 port, port,
1810 !net_eq(sock_net(sk),
1811 dev_net(gtp->dev)),
1812 false);
1813 return 0;
1814}
1815
1816static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1817 [GTPA_LINK] = { .type = NLA_U32, },
1818 [GTPA_VERSION] = { .type = NLA_U32, },
1819 [GTPA_TID] = { .type = NLA_U64, },
1820 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1821 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1822 [GTPA_FLOW] = { .type = NLA_U16, },
1823 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1824 [GTPA_I_TEI] = { .type = NLA_U32, },
1825 [GTPA_O_TEI] = { .type = NLA_U32, },
1826};
1827
1828static const struct genl_small_ops gtp_genl_ops[] = {
1829 {
1830 .cmd = GTP_CMD_NEWPDP,
1831 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1832 .doit = gtp_genl_new_pdp,
1833 .flags = GENL_ADMIN_PERM,
1834 },
1835 {
1836 .cmd = GTP_CMD_DELPDP,
1837 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1838 .doit = gtp_genl_del_pdp,
1839 .flags = GENL_ADMIN_PERM,
1840 },
1841 {
1842 .cmd = GTP_CMD_GETPDP,
1843 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1844 .doit = gtp_genl_get_pdp,
1845 .dumpit = gtp_genl_dump_pdp,
1846 .flags = GENL_ADMIN_PERM,
1847 },
1848 {
1849 .cmd = GTP_CMD_ECHOREQ,
1850 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1851 .doit = gtp_genl_send_echo_req,
1852 .flags = GENL_ADMIN_PERM,
1853 },
1854};
1855
1856static struct genl_family gtp_genl_family __ro_after_init = {
1857 .name = "gtp",
1858 .version = 0,
1859 .hdrsize = 0,
1860 .maxattr = GTPA_MAX,
1861 .policy = gtp_genl_policy,
1862 .netnsok = true,
1863 .module = THIS_MODULE,
1864 .small_ops = gtp_genl_ops,
1865 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
1866 .resv_start_op = GTP_CMD_ECHOREQ + 1,
1867 .mcgrps = gtp_genl_mcgrps,
1868 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
1869};
1870
1871static int __net_init gtp_net_init(struct net *net)
1872{
1873 struct gtp_net *gn = net_generic(net, gtp_net_id);
1874
1875 INIT_LIST_HEAD(&gn->gtp_dev_list);
1876 return 0;
1877}
1878
1879static void __net_exit gtp_net_exit(struct net *net)
1880{
1881 struct gtp_net *gn = net_generic(net, gtp_net_id);
1882 struct gtp_dev *gtp;
1883 LIST_HEAD(list);
1884
1885 rtnl_lock();
1886 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1887 gtp_dellink(gtp->dev, &list);
1888
1889 unregister_netdevice_many(&list);
1890 rtnl_unlock();
1891}
1892
1893static struct pernet_operations gtp_net_ops = {
1894 .init = gtp_net_init,
1895 .exit = gtp_net_exit,
1896 .id = >p_net_id,
1897 .size = sizeof(struct gtp_net),
1898};
1899
1900static int __init gtp_init(void)
1901{
1902 int err;
1903
1904 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1905
1906 err = register_pernet_subsys(>p_net_ops);
1907 if (err < 0)
1908 goto error_out;
1909
1910 err = rtnl_link_register(>p_link_ops);
1911 if (err < 0)
1912 goto unreg_pernet_subsys;
1913
1914 err = genl_register_family(>p_genl_family);
1915 if (err < 0)
1916 goto unreg_rtnl_link;
1917
1918 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1919 sizeof(struct pdp_ctx));
1920 return 0;
1921
1922unreg_rtnl_link:
1923 rtnl_link_unregister(>p_link_ops);
1924unreg_pernet_subsys:
1925 unregister_pernet_subsys(>p_net_ops);
1926error_out:
1927 pr_err("error loading GTP module loaded\n");
1928 return err;
1929}
1930late_initcall(gtp_init);
1931
1932static void __exit gtp_fini(void)
1933{
1934 genl_unregister_family(>p_genl_family);
1935 rtnl_link_unregister(>p_link_ops);
1936 unregister_pernet_subsys(>p_net_ops);
1937
1938 pr_info("GTP module unloaded\n");
1939}
1940module_exit(gtp_fini);
1941
1942MODULE_LICENSE("GPL");
1943MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1944MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1945MODULE_ALIAS_RTNL_LINK("gtp");
1946MODULE_ALIAS_GENL_FAMILY("gtp");
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/ipv6.h>
28#include <net/udp.h>
29#include <net/udp_tunnel.h>
30#include <net/icmp.h>
31#include <net/xfrm.h>
32#include <net/genetlink.h>
33#include <net/netns/generic.h>
34#include <net/gtp.h>
35
36/* An active session for the subscriber. */
37struct pdp_ctx {
38 struct hlist_node hlist_tid;
39 struct hlist_node hlist_addr;
40
41 union {
42 struct {
43 u64 tid;
44 u16 flow;
45 } v0;
46 struct {
47 u32 i_tei;
48 u32 o_tei;
49 } v1;
50 } u;
51 u8 gtp_version;
52 u16 af;
53
54 union {
55 struct in_addr addr;
56 struct in6_addr addr6;
57 } ms;
58 union {
59 struct in_addr addr;
60 struct in6_addr addr6;
61 } peer;
62
63 struct sock *sk;
64 struct net_device *dev;
65
66 atomic_t tx_seq;
67 struct rcu_head rcu_head;
68};
69
70/* One instance of the GTP device. */
71struct gtp_dev {
72 struct list_head list;
73
74 struct sock *sk0;
75 struct sock *sk1u;
76 u8 sk_created;
77
78 struct net_device *dev;
79 struct net *net;
80
81 unsigned int role;
82 unsigned int hash_size;
83 struct hlist_head *tid_hash;
84 struct hlist_head *addr_hash;
85
86 u8 restart_count;
87};
88
89struct echo_info {
90 u16 af;
91 u8 gtp_version;
92
93 union {
94 struct in_addr addr;
95 } ms;
96 union {
97 struct in_addr addr;
98 } peer;
99};
100
101static unsigned int gtp_net_id __read_mostly;
102
103struct gtp_net {
104 struct list_head gtp_dev_list;
105};
106
107static u32 gtp_h_initval;
108
109static struct genl_family gtp_genl_family;
110
111enum gtp_multicast_groups {
112 GTP_GENL_MCGRP,
113};
114
115static const struct genl_multicast_group gtp_genl_mcgrps[] = {
116 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
117};
118
119static void pdp_context_delete(struct pdp_ctx *pctx);
120
121static inline u32 gtp0_hashfn(u64 tid)
122{
123 u32 *tid32 = (u32 *) &tid;
124 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
125}
126
127static inline u32 gtp1u_hashfn(u32 tid)
128{
129 return jhash_1word(tid, gtp_h_initval);
130}
131
132static inline u32 ipv4_hashfn(__be32 ip)
133{
134 return jhash_1word((__force u32)ip, gtp_h_initval);
135}
136
137static u32 ipv6_hashfn(const struct in6_addr *ip6)
138{
139 return jhash_2words((__force u32)ip6->s6_addr32[0],
140 (__force u32)ip6->s6_addr32[1], gtp_h_initval);
141}
142
143/* Resolve a PDP context structure based on the 64bit TID. */
144static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid, u16 family)
145{
146 struct hlist_head *head;
147 struct pdp_ctx *pdp;
148
149 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
150
151 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
152 if (pdp->af == family &&
153 pdp->gtp_version == GTP_V0 &&
154 pdp->u.v0.tid == tid)
155 return pdp;
156 }
157 return NULL;
158}
159
160/* Resolve a PDP context structure based on the 32bit TEI. */
161static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid, u16 family)
162{
163 struct hlist_head *head;
164 struct pdp_ctx *pdp;
165
166 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
167
168 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
169 if (pdp->af == family &&
170 pdp->gtp_version == GTP_V1 &&
171 pdp->u.v1.i_tei == tid)
172 return pdp;
173 }
174 return NULL;
175}
176
177/* Resolve a PDP context based on IPv4 address of MS. */
178static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
179{
180 struct hlist_head *head;
181 struct pdp_ctx *pdp;
182
183 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
184
185 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
186 if (pdp->af == AF_INET &&
187 pdp->ms.addr.s_addr == ms_addr)
188 return pdp;
189 }
190
191 return NULL;
192}
193
194/* 3GPP TS 29.060: PDN Connection: the association between a MS represented by
195 * [...] one IPv6 *prefix* and a PDN represented by an APN.
196 *
197 * Then, 3GPP TS 29.061, Section 11.2.1.3 says: The size of the prefix shall be
198 * according to the maximum prefix length for a global IPv6 address as
199 * specified in the IPv6 Addressing Architecture, see RFC 4291.
200 *
201 * Finally, RFC 4291 section 2.5.4 states: All Global Unicast addresses other
202 * than those that start with binary 000 have a 64-bit interface ID field
203 * (i.e., n + m = 64).
204 */
205static bool ipv6_pdp_addr_equal(const struct in6_addr *a,
206 const struct in6_addr *b)
207{
208 return a->s6_addr32[0] == b->s6_addr32[0] &&
209 a->s6_addr32[1] == b->s6_addr32[1];
210}
211
212static struct pdp_ctx *ipv6_pdp_find(struct gtp_dev *gtp,
213 const struct in6_addr *ms_addr)
214{
215 struct hlist_head *head;
216 struct pdp_ctx *pdp;
217
218 head = >p->addr_hash[ipv6_hashfn(ms_addr) % gtp->hash_size];
219
220 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
221 if (pdp->af == AF_INET6 &&
222 ipv6_pdp_addr_equal(&pdp->ms.addr6, ms_addr))
223 return pdp;
224 }
225
226 return NULL;
227}
228
229static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
230 unsigned int hdrlen, unsigned int role)
231{
232 struct iphdr *iph;
233
234 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
235 return false;
236
237 iph = (struct iphdr *)(skb->data + hdrlen);
238
239 if (role == GTP_ROLE_SGSN)
240 return iph->daddr == pctx->ms.addr.s_addr;
241 else
242 return iph->saddr == pctx->ms.addr.s_addr;
243}
244
245static bool gtp_check_ms_ipv6(struct sk_buff *skb, struct pdp_ctx *pctx,
246 unsigned int hdrlen, unsigned int role)
247{
248 struct ipv6hdr *ip6h;
249 int ret;
250
251 if (!pskb_may_pull(skb, hdrlen + sizeof(struct ipv6hdr)))
252 return false;
253
254 ip6h = (struct ipv6hdr *)(skb->data + hdrlen);
255
256 if ((ipv6_addr_type(&ip6h->saddr) & IPV6_ADDR_LINKLOCAL) ||
257 (ipv6_addr_type(&ip6h->daddr) & IPV6_ADDR_LINKLOCAL))
258 return false;
259
260 if (role == GTP_ROLE_SGSN) {
261 ret = ipv6_pdp_addr_equal(&ip6h->daddr, &pctx->ms.addr6);
262 } else {
263 ret = ipv6_pdp_addr_equal(&ip6h->saddr, &pctx->ms.addr6);
264 }
265
266 return ret;
267}
268
269/* Check if the inner IP address in this packet is assigned to any
270 * existing mobile subscriber.
271 */
272static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
273 unsigned int hdrlen, unsigned int role,
274 __u16 inner_proto)
275{
276 switch (inner_proto) {
277 case ETH_P_IP:
278 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
279 case ETH_P_IPV6:
280 return gtp_check_ms_ipv6(skb, pctx, hdrlen, role);
281 }
282 return false;
283}
284
285static int gtp_inner_proto(struct sk_buff *skb, unsigned int hdrlen,
286 __u16 *inner_proto)
287{
288 __u8 *ip_version, _ip_version;
289
290 ip_version = skb_header_pointer(skb, hdrlen, sizeof(*ip_version),
291 &_ip_version);
292 if (!ip_version)
293 return -1;
294
295 switch (*ip_version & 0xf0) {
296 case 0x40:
297 *inner_proto = ETH_P_IP;
298 break;
299 case 0x60:
300 *inner_proto = ETH_P_IPV6;
301 break;
302 default:
303 return -1;
304 }
305
306 return 0;
307}
308
309static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
310 unsigned int hdrlen, unsigned int role, __u16 inner_proto)
311{
312 if (!gtp_check_ms(skb, pctx, hdrlen, role, inner_proto)) {
313 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
314 return 1;
315 }
316
317 /* Get rid of the GTP + UDP headers. */
318 if (iptunnel_pull_header(skb, hdrlen, htons(inner_proto),
319 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
320 pctx->dev->stats.rx_length_errors++;
321 goto err;
322 }
323
324 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
325
326 /* Now that the UDP and the GTP header have been removed, set up the
327 * new network header. This is required by the upper layer to
328 * calculate the transport header.
329 */
330 skb_reset_network_header(skb);
331 skb_reset_mac_header(skb);
332
333 skb->dev = pctx->dev;
334
335 dev_sw_netstats_rx_add(pctx->dev, skb->len);
336
337 __netif_rx(skb);
338 return 0;
339
340err:
341 pctx->dev->stats.rx_dropped++;
342 return -1;
343}
344
345static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
346 const struct sock *sk,
347 __be32 daddr, __be32 saddr)
348{
349 memset(fl4, 0, sizeof(*fl4));
350 fl4->flowi4_oif = sk->sk_bound_dev_if;
351 fl4->daddr = daddr;
352 fl4->saddr = saddr;
353 fl4->flowi4_tos = ip_sock_rt_tos(sk);
354 fl4->flowi4_scope = ip_sock_rt_scope(sk);
355 fl4->flowi4_proto = sk->sk_protocol;
356
357 return ip_route_output_key(sock_net(sk), fl4);
358}
359
360static struct rt6_info *ip6_route_output_gtp(struct net *net,
361 struct flowi6 *fl6,
362 const struct sock *sk,
363 const struct in6_addr *daddr,
364 struct in6_addr *saddr)
365{
366 struct dst_entry *dst;
367
368 memset(fl6, 0, sizeof(*fl6));
369 fl6->flowi6_oif = sk->sk_bound_dev_if;
370 fl6->daddr = *daddr;
371 fl6->saddr = *saddr;
372 fl6->flowi6_proto = sk->sk_protocol;
373
374 dst = ipv6_stub->ipv6_dst_lookup_flow(net, sk, fl6, NULL);
375 if (IS_ERR(dst))
376 return ERR_PTR(-ENETUNREACH);
377
378 return (struct rt6_info *)dst;
379}
380
381/* GSM TS 09.60. 7.3
382 * In all Path Management messages:
383 * - TID: is not used and shall be set to 0.
384 * - Flow Label is not used and shall be set to 0
385 * In signalling messages:
386 * - number: this field is not yet used in signalling messages.
387 * It shall be set to 255 by the sender and shall be ignored
388 * by the receiver
389 * Returns true if the echo req was correct, false otherwise.
390 */
391static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0)
392{
393 return !(gtp0->tid || (gtp0->flags ^ 0x1e) ||
394 gtp0->number != 0xff || gtp0->flow);
395}
396
397/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
398static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type)
399{
400 int len_pkt, len_hdr;
401
402 hdr->flags = 0x1e; /* v0, GTP-non-prime. */
403 hdr->type = msg_type;
404 /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID
405 * are not used and shall be set to 0.
406 */
407 hdr->flow = 0;
408 hdr->tid = 0;
409 hdr->number = 0xff;
410 hdr->spare[0] = 0xff;
411 hdr->spare[1] = 0xff;
412 hdr->spare[2] = 0xff;
413
414 len_pkt = sizeof(struct gtp0_packet);
415 len_hdr = sizeof(struct gtp0_header);
416
417 if (msg_type == GTP_ECHO_RSP)
418 hdr->length = htons(len_pkt - len_hdr);
419 else
420 hdr->length = 0;
421}
422
423static int gtp0_send_echo_resp_ip(struct gtp_dev *gtp, struct sk_buff *skb)
424{
425 struct iphdr *iph = ip_hdr(skb);
426 struct flowi4 fl4;
427 struct rtable *rt;
428
429 /* find route to the sender,
430 * src address becomes dst address and vice versa.
431 */
432 rt = ip4_route_output_gtp(&fl4, gtp->sk0, iph->saddr, iph->daddr);
433 if (IS_ERR(rt)) {
434 netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
435 &iph->saddr);
436 return -1;
437 }
438
439 udp_tunnel_xmit_skb(rt, gtp->sk0, skb,
440 fl4.saddr, fl4.daddr,
441 iph->tos,
442 ip4_dst_hoplimit(&rt->dst),
443 0,
444 htons(GTP0_PORT), htons(GTP0_PORT),
445 !net_eq(sock_net(gtp->sk1u),
446 dev_net(gtp->dev)),
447 false);
448
449 return 0;
450}
451
452static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
453{
454 struct gtp0_packet *gtp_pkt;
455 struct gtp0_header *gtp0;
456 __be16 seq;
457
458 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
459
460 if (!gtp0_validate_echo_hdr(gtp0))
461 return -1;
462
463 seq = gtp0->seq;
464
465 /* pull GTP and UDP headers */
466 skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr));
467
468 gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet));
469 memset(gtp_pkt, 0, sizeof(struct gtp0_packet));
470
471 gtp0_build_echo_msg(>p_pkt->gtp0_h, GTP_ECHO_RSP);
472
473 /* GSM TS 09.60. 7.3 The Sequence Number in a signalling response
474 * message shall be copied from the signalling request message
475 * that the GSN is replying to.
476 */
477 gtp_pkt->gtp0_h.seq = seq;
478
479 gtp_pkt->ie.tag = GTPIE_RECOVERY;
480 gtp_pkt->ie.val = gtp->restart_count;
481
482 switch (gtp->sk0->sk_family) {
483 case AF_INET:
484 if (gtp0_send_echo_resp_ip(gtp, skb) < 0)
485 return -1;
486 break;
487 case AF_INET6:
488 return -1;
489 }
490
491 return 0;
492}
493
494static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
495 int flags, u32 type, struct echo_info echo)
496{
497 void *genlh;
498
499 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
500 type);
501 if (!genlh)
502 goto failure;
503
504 if (nla_put_u32(skb, GTPA_VERSION, echo.gtp_version) ||
505 nla_put_be32(skb, GTPA_PEER_ADDRESS, echo.peer.addr.s_addr) ||
506 nla_put_be32(skb, GTPA_MS_ADDRESS, echo.ms.addr.s_addr))
507 goto failure;
508
509 genlmsg_end(skb, genlh);
510 return 0;
511
512failure:
513 genlmsg_cancel(skb, genlh);
514 return -EMSGSIZE;
515}
516
517static void gtp0_handle_echo_resp_ip(struct sk_buff *skb, struct echo_info *echo)
518{
519 struct iphdr *iph = ip_hdr(skb);
520
521 echo->ms.addr.s_addr = iph->daddr;
522 echo->peer.addr.s_addr = iph->saddr;
523 echo->gtp_version = GTP_V0;
524}
525
526static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
527{
528 struct gtp0_header *gtp0;
529 struct echo_info echo;
530 struct sk_buff *msg;
531 int ret;
532
533 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
534
535 if (!gtp0_validate_echo_hdr(gtp0))
536 return -1;
537
538 switch (gtp->sk0->sk_family) {
539 case AF_INET:
540 gtp0_handle_echo_resp_ip(skb, &echo);
541 break;
542 case AF_INET6:
543 return -1;
544 }
545
546 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
547 if (!msg)
548 return -ENOMEM;
549
550 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
551 if (ret < 0) {
552 nlmsg_free(msg);
553 return ret;
554 }
555
556 return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev),
557 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
558}
559
560static int gtp_proto_to_family(__u16 proto)
561{
562 switch (proto) {
563 case ETH_P_IP:
564 return AF_INET;
565 case ETH_P_IPV6:
566 return AF_INET6;
567 default:
568 WARN_ON_ONCE(1);
569 break;
570 }
571
572 return AF_UNSPEC;
573}
574
575/* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */
576static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
577{
578 unsigned int hdrlen = sizeof(struct udphdr) +
579 sizeof(struct gtp0_header);
580 struct gtp0_header *gtp0;
581 struct pdp_ctx *pctx;
582 __u16 inner_proto;
583
584 if (!pskb_may_pull(skb, hdrlen))
585 return -1;
586
587 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
588
589 if ((gtp0->flags >> 5) != GTP_V0)
590 return 1;
591
592 /* If the sockets were created in kernel, it means that
593 * there is no daemon running in userspace which would
594 * handle echo request.
595 */
596 if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
597 return gtp0_send_echo_resp(gtp, skb);
598
599 if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created)
600 return gtp0_handle_echo_resp(gtp, skb);
601
602 if (gtp0->type != GTP_TPDU)
603 return 1;
604
605 if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
606 netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
607 return -1;
608 }
609
610 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid),
611 gtp_proto_to_family(inner_proto));
612 if (!pctx) {
613 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
614 return 1;
615 }
616
617 return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
618}
619
620/* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
621static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type)
622{
623 int len_pkt, len_hdr;
624
625 /* S flag must be set to 1 */
626 hdr->flags = 0x32; /* v1, GTP-non-prime. */
627 hdr->type = msg_type;
628 /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */
629 hdr->tid = 0;
630
631 /* seq, npdu and next should be counted to the length of the GTP packet
632 * that's why szie of gtp1_header should be subtracted,
633 * not size of gtp1_header_long.
634 */
635
636 len_hdr = sizeof(struct gtp1_header);
637
638 if (msg_type == GTP_ECHO_RSP) {
639 len_pkt = sizeof(struct gtp1u_packet);
640 hdr->length = htons(len_pkt - len_hdr);
641 } else {
642 /* GTP_ECHO_REQ does not carry GTP Information Element,
643 * the why gtp1_header_long is used here.
644 */
645 len_pkt = sizeof(struct gtp1_header_long);
646 hdr->length = htons(len_pkt - len_hdr);
647 }
648}
649
650static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
651{
652 struct gtp1_header_long *gtp1u;
653 struct gtp1u_packet *gtp_pkt;
654 struct rtable *rt;
655 struct flowi4 fl4;
656 struct iphdr *iph;
657
658 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
659
660 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
661 * Error Indication and Supported Extension Headers Notification
662 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
663 */
664 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
665 return -1;
666
667 /* pull GTP and UDP headers */
668 skb_pull_data(skb,
669 sizeof(struct gtp1_header_long) + sizeof(struct udphdr));
670
671 gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet));
672 memset(gtp_pkt, 0, sizeof(struct gtp1u_packet));
673
674 gtp1u_build_echo_msg(>p_pkt->gtp1u_h, GTP_ECHO_RSP);
675
676 /* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the
677 * Recovery information element shall not be used, i.e. it shall
678 * be set to zero by the sender and shall be ignored by the receiver.
679 * The Recovery information element is mandatory due to backwards
680 * compatibility reasons.
681 */
682 gtp_pkt->ie.tag = GTPIE_RECOVERY;
683 gtp_pkt->ie.val = 0;
684
685 iph = ip_hdr(skb);
686
687 /* find route to the sender,
688 * src address becomes dst address and vice versa.
689 */
690 rt = ip4_route_output_gtp(&fl4, gtp->sk1u, iph->saddr, iph->daddr);
691 if (IS_ERR(rt)) {
692 netdev_dbg(gtp->dev, "no route for echo response from %pI4\n",
693 &iph->saddr);
694 return -1;
695 }
696
697 udp_tunnel_xmit_skb(rt, gtp->sk1u, skb,
698 fl4.saddr, fl4.daddr,
699 iph->tos,
700 ip4_dst_hoplimit(&rt->dst),
701 0,
702 htons(GTP1U_PORT), htons(GTP1U_PORT),
703 !net_eq(sock_net(gtp->sk1u),
704 dev_net(gtp->dev)),
705 false);
706 return 0;
707}
708
709static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
710{
711 struct gtp1_header_long *gtp1u;
712 struct echo_info echo;
713 struct sk_buff *msg;
714 struct iphdr *iph;
715 int ret;
716
717 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
718
719 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
720 * Error Indication and Supported Extension Headers Notification
721 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
722 */
723 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
724 return -1;
725
726 iph = ip_hdr(skb);
727 echo.ms.addr.s_addr = iph->daddr;
728 echo.peer.addr.s_addr = iph->saddr;
729 echo.gtp_version = GTP_V1;
730
731 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
732 if (!msg)
733 return -ENOMEM;
734
735 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
736 if (ret < 0) {
737 nlmsg_free(msg);
738 return ret;
739 }
740
741 return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev),
742 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
743}
744
745static int gtp_parse_exthdrs(struct sk_buff *skb, unsigned int *hdrlen)
746{
747 struct gtp_ext_hdr *gtp_exthdr, _gtp_exthdr;
748 unsigned int offset = *hdrlen;
749 __u8 *next_type, _next_type;
750
751 /* From 29.060: "The Extension Header Length field specifies the length
752 * of the particular Extension header in 4 octets units."
753 *
754 * This length field includes length field size itself (1 byte),
755 * payload (variable length) and next type (1 byte). The extension
756 * header is aligned to to 4 bytes.
757 */
758
759 do {
760 gtp_exthdr = skb_header_pointer(skb, offset, sizeof(*gtp_exthdr),
761 &_gtp_exthdr);
762 if (!gtp_exthdr || !gtp_exthdr->len)
763 return -1;
764
765 offset += gtp_exthdr->len * 4;
766
767 /* From 29.060: "If no such Header follows, then the value of
768 * the Next Extension Header Type shall be 0."
769 */
770 next_type = skb_header_pointer(skb, offset - 1,
771 sizeof(_next_type), &_next_type);
772 if (!next_type)
773 return -1;
774
775 } while (*next_type != 0);
776
777 *hdrlen = offset;
778
779 return 0;
780}
781
782static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
783{
784 unsigned int hdrlen = sizeof(struct udphdr) +
785 sizeof(struct gtp1_header);
786 struct gtp1_header *gtp1;
787 struct pdp_ctx *pctx;
788 __u16 inner_proto;
789
790 if (!pskb_may_pull(skb, hdrlen))
791 return -1;
792
793 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
794
795 if ((gtp1->flags >> 5) != GTP_V1)
796 return 1;
797
798 /* If the sockets were created in kernel, it means that
799 * there is no daemon running in userspace which would
800 * handle echo request.
801 */
802 if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)
803 return gtp1u_send_echo_resp(gtp, skb);
804
805 if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created)
806 return gtp1u_handle_echo_resp(gtp, skb);
807
808 if (gtp1->type != GTP_TPDU)
809 return 1;
810
811 /* From 29.060: "This field shall be present if and only if any one or
812 * more of the S, PN and E flags are set.".
813 *
814 * If any of the bit is set, then the remaining ones also have to be
815 * set.
816 */
817 if (gtp1->flags & GTP1_F_MASK)
818 hdrlen += 4;
819
820 /* Make sure the header is larger enough, including extensions. */
821 if (!pskb_may_pull(skb, hdrlen))
822 return -1;
823
824 if (gtp_inner_proto(skb, hdrlen, &inner_proto) < 0) {
825 netdev_dbg(gtp->dev, "GTP packet does not encapsulate an IP packet\n");
826 return -1;
827 }
828
829 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
830
831 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid),
832 gtp_proto_to_family(inner_proto));
833 if (!pctx) {
834 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
835 return 1;
836 }
837
838 if (gtp1->flags & GTP1_F_EXTHDR &&
839 gtp_parse_exthdrs(skb, &hdrlen) < 0)
840 return -1;
841
842 return gtp_rx(pctx, skb, hdrlen, gtp->role, inner_proto);
843}
844
845static void __gtp_encap_destroy(struct sock *sk)
846{
847 struct gtp_dev *gtp;
848
849 lock_sock(sk);
850 gtp = sk->sk_user_data;
851 if (gtp) {
852 if (gtp->sk0 == sk)
853 gtp->sk0 = NULL;
854 else
855 gtp->sk1u = NULL;
856 WRITE_ONCE(udp_sk(sk)->encap_type, 0);
857 rcu_assign_sk_user_data(sk, NULL);
858 release_sock(sk);
859 sock_put(sk);
860 return;
861 }
862 release_sock(sk);
863}
864
865static void gtp_encap_destroy(struct sock *sk)
866{
867 rtnl_lock();
868 __gtp_encap_destroy(sk);
869 rtnl_unlock();
870}
871
872static void gtp_encap_disable_sock(struct sock *sk)
873{
874 if (!sk)
875 return;
876
877 __gtp_encap_destroy(sk);
878}
879
880static void gtp_encap_disable(struct gtp_dev *gtp)
881{
882 if (gtp->sk_created) {
883 udp_tunnel_sock_release(gtp->sk0->sk_socket);
884 udp_tunnel_sock_release(gtp->sk1u->sk_socket);
885 gtp->sk_created = false;
886 gtp->sk0 = NULL;
887 gtp->sk1u = NULL;
888 } else {
889 gtp_encap_disable_sock(gtp->sk0);
890 gtp_encap_disable_sock(gtp->sk1u);
891 }
892}
893
894/* UDP encapsulation receive handler. See net/ipv4/udp.c.
895 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
896 */
897static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
898{
899 struct gtp_dev *gtp;
900 int ret = 0;
901
902 gtp = rcu_dereference_sk_user_data(sk);
903 if (!gtp)
904 return 1;
905
906 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
907
908 switch (READ_ONCE(udp_sk(sk)->encap_type)) {
909 case UDP_ENCAP_GTP0:
910 netdev_dbg(gtp->dev, "received GTP0 packet\n");
911 ret = gtp0_udp_encap_recv(gtp, skb);
912 break;
913 case UDP_ENCAP_GTP1U:
914 netdev_dbg(gtp->dev, "received GTP1U packet\n");
915 ret = gtp1u_udp_encap_recv(gtp, skb);
916 break;
917 default:
918 ret = -1; /* Shouldn't happen. */
919 }
920
921 switch (ret) {
922 case 1:
923 netdev_dbg(gtp->dev, "pass up to the process\n");
924 break;
925 case 0:
926 break;
927 case -1:
928 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
929 kfree_skb(skb);
930 ret = 0;
931 break;
932 }
933
934 return ret;
935}
936
937static void gtp_dev_uninit(struct net_device *dev)
938{
939 struct gtp_dev *gtp = netdev_priv(dev);
940
941 gtp_encap_disable(gtp);
942}
943
944static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
945{
946 int payload_len = skb->len;
947 struct gtp0_header *gtp0;
948
949 gtp0 = skb_push(skb, sizeof(*gtp0));
950
951 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
952 gtp0->type = GTP_TPDU;
953 gtp0->length = htons(payload_len);
954 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
955 gtp0->flow = htons(pctx->u.v0.flow);
956 gtp0->number = 0xff;
957 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
958 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
959}
960
961static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
962{
963 int payload_len = skb->len;
964 struct gtp1_header *gtp1;
965
966 gtp1 = skb_push(skb, sizeof(*gtp1));
967
968 /* Bits 8 7 6 5 4 3 2 1
969 * +--+--+--+--+--+--+--+--+
970 * |version |PT| 0| E| S|PN|
971 * +--+--+--+--+--+--+--+--+
972 * 0 0 1 1 1 0 0 0
973 */
974 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
975 gtp1->type = GTP_TPDU;
976 gtp1->length = htons(payload_len);
977 gtp1->tid = htonl(pctx->u.v1.o_tei);
978
979 /* TODO: Support for extension header, sequence number and N-PDU.
980 * Update the length field if any of them is available.
981 */
982}
983
984struct gtp_pktinfo {
985 struct sock *sk;
986 union {
987 struct flowi4 fl4;
988 struct flowi6 fl6;
989 };
990 union {
991 struct rtable *rt;
992 struct rt6_info *rt6;
993 };
994 struct pdp_ctx *pctx;
995 struct net_device *dev;
996 __u8 tos;
997 __be16 gtph_port;
998};
999
1000static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
1001{
1002 switch (pktinfo->pctx->gtp_version) {
1003 case GTP_V0:
1004 pktinfo->gtph_port = htons(GTP0_PORT);
1005 gtp0_push_header(skb, pktinfo->pctx);
1006 break;
1007 case GTP_V1:
1008 pktinfo->gtph_port = htons(GTP1U_PORT);
1009 gtp1_push_header(skb, pktinfo->pctx);
1010 break;
1011 }
1012}
1013
1014static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
1015 struct sock *sk, __u8 tos,
1016 struct pdp_ctx *pctx, struct rtable *rt,
1017 struct flowi4 *fl4,
1018 struct net_device *dev)
1019{
1020 pktinfo->sk = sk;
1021 pktinfo->tos = tos;
1022 pktinfo->pctx = pctx;
1023 pktinfo->rt = rt;
1024 pktinfo->fl4 = *fl4;
1025 pktinfo->dev = dev;
1026}
1027
1028static void gtp_set_pktinfo_ipv6(struct gtp_pktinfo *pktinfo,
1029 struct sock *sk, __u8 tos,
1030 struct pdp_ctx *pctx, struct rt6_info *rt6,
1031 struct flowi6 *fl6,
1032 struct net_device *dev)
1033{
1034 pktinfo->sk = sk;
1035 pktinfo->tos = tos;
1036 pktinfo->pctx = pctx;
1037 pktinfo->rt6 = rt6;
1038 pktinfo->fl6 = *fl6;
1039 pktinfo->dev = dev;
1040}
1041
1042static int gtp_build_skb_outer_ip4(struct sk_buff *skb, struct net_device *dev,
1043 struct gtp_pktinfo *pktinfo,
1044 struct pdp_ctx *pctx, __u8 tos,
1045 __be16 frag_off)
1046{
1047 struct rtable *rt;
1048 struct flowi4 fl4;
1049 __be16 df;
1050 int mtu;
1051
1052 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer.addr.s_addr,
1053 inet_sk(pctx->sk)->inet_saddr);
1054 if (IS_ERR(rt)) {
1055 netdev_dbg(dev, "no route to SSGN %pI4\n",
1056 &pctx->peer.addr.s_addr);
1057 dev->stats.tx_carrier_errors++;
1058 goto err;
1059 }
1060
1061 if (rt->dst.dev == dev) {
1062 netdev_dbg(dev, "circular route to SSGN %pI4\n",
1063 &pctx->peer.addr.s_addr);
1064 dev->stats.collisions++;
1065 goto err_rt;
1066 }
1067
1068 /* This is similar to tnl_update_pmtu(). */
1069 df = frag_off;
1070 if (df) {
1071 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
1072 sizeof(struct iphdr) - sizeof(struct udphdr);
1073 switch (pctx->gtp_version) {
1074 case GTP_V0:
1075 mtu -= sizeof(struct gtp0_header);
1076 break;
1077 case GTP_V1:
1078 mtu -= sizeof(struct gtp1_header);
1079 break;
1080 }
1081 } else {
1082 mtu = dst_mtu(&rt->dst);
1083 }
1084
1085 skb_dst_update_pmtu_no_confirm(skb, mtu);
1086
1087 if (frag_off & htons(IP_DF) &&
1088 ((!skb_is_gso(skb) && skb->len > mtu) ||
1089 (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) {
1090 netdev_dbg(dev, "packet too big, fragmentation needed\n");
1091 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
1092 htonl(mtu));
1093 goto err_rt;
1094 }
1095
1096 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, tos, pctx, rt, &fl4, dev);
1097 gtp_push_header(skb, pktinfo);
1098
1099 return 0;
1100err_rt:
1101 ip_rt_put(rt);
1102err:
1103 return -EBADMSG;
1104}
1105
1106static int gtp_build_skb_outer_ip6(struct net *net, struct sk_buff *skb,
1107 struct net_device *dev,
1108 struct gtp_pktinfo *pktinfo,
1109 struct pdp_ctx *pctx, __u8 tos)
1110{
1111 struct dst_entry *dst;
1112 struct rt6_info *rt;
1113 struct flowi6 fl6;
1114 int mtu;
1115
1116 rt = ip6_route_output_gtp(net, &fl6, pctx->sk, &pctx->peer.addr6,
1117 &inet6_sk(pctx->sk)->saddr);
1118 if (IS_ERR(rt)) {
1119 netdev_dbg(dev, "no route to SSGN %pI6\n",
1120 &pctx->peer.addr6);
1121 dev->stats.tx_carrier_errors++;
1122 goto err;
1123 }
1124 dst = &rt->dst;
1125
1126 if (rt->dst.dev == dev) {
1127 netdev_dbg(dev, "circular route to SSGN %pI6\n",
1128 &pctx->peer.addr6);
1129 dev->stats.collisions++;
1130 goto err_rt;
1131 }
1132
1133 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
1134 sizeof(struct ipv6hdr) - sizeof(struct udphdr);
1135 switch (pctx->gtp_version) {
1136 case GTP_V0:
1137 mtu -= sizeof(struct gtp0_header);
1138 break;
1139 case GTP_V1:
1140 mtu -= sizeof(struct gtp1_header);
1141 break;
1142 }
1143
1144 skb_dst_update_pmtu_no_confirm(skb, mtu);
1145
1146 if ((!skb_is_gso(skb) && skb->len > mtu) ||
1147 (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu))) {
1148 netdev_dbg(dev, "packet too big, fragmentation needed\n");
1149 icmpv6_ndo_send(skb, ICMPV6_PKT_TOOBIG, 0, mtu);
1150 goto err_rt;
1151 }
1152
1153 gtp_set_pktinfo_ipv6(pktinfo, pctx->sk, tos, pctx, rt, &fl6, dev);
1154 gtp_push_header(skb, pktinfo);
1155
1156 return 0;
1157err_rt:
1158 dst_release(dst);
1159err:
1160 return -EBADMSG;
1161}
1162
1163static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
1164 struct gtp_pktinfo *pktinfo)
1165{
1166 struct gtp_dev *gtp = netdev_priv(dev);
1167 struct net *net = gtp->net;
1168 struct pdp_ctx *pctx;
1169 struct iphdr *iph;
1170 int ret;
1171
1172 /* Read the IP destination address and resolve the PDP context.
1173 * Prepend PDP header with TEI/TID from PDP ctx.
1174 */
1175 iph = ip_hdr(skb);
1176 if (gtp->role == GTP_ROLE_SGSN)
1177 pctx = ipv4_pdp_find(gtp, iph->saddr);
1178 else
1179 pctx = ipv4_pdp_find(gtp, iph->daddr);
1180
1181 if (!pctx) {
1182 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
1183 &iph->daddr);
1184 return -ENOENT;
1185 }
1186 netdev_dbg(dev, "found PDP context %p\n", pctx);
1187
1188 switch (pctx->sk->sk_family) {
1189 case AF_INET:
1190 ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx,
1191 iph->tos, iph->frag_off);
1192 break;
1193 case AF_INET6:
1194 ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx,
1195 iph->tos);
1196 break;
1197 default:
1198 ret = -1;
1199 WARN_ON_ONCE(1);
1200 break;
1201 }
1202
1203 if (ret < 0)
1204 return ret;
1205
1206 netdev_dbg(dev, "gtp -> IP src: %pI4 dst: %pI4\n",
1207 &iph->saddr, &iph->daddr);
1208
1209 return 0;
1210}
1211
1212static int gtp_build_skb_ip6(struct sk_buff *skb, struct net_device *dev,
1213 struct gtp_pktinfo *pktinfo)
1214{
1215 struct gtp_dev *gtp = netdev_priv(dev);
1216 struct net *net = gtp->net;
1217 struct pdp_ctx *pctx;
1218 struct ipv6hdr *ip6h;
1219 __u8 tos;
1220 int ret;
1221
1222 /* Read the IP destination address and resolve the PDP context.
1223 * Prepend PDP header with TEI/TID from PDP ctx.
1224 */
1225 ip6h = ipv6_hdr(skb);
1226 if (gtp->role == GTP_ROLE_SGSN)
1227 pctx = ipv6_pdp_find(gtp, &ip6h->saddr);
1228 else
1229 pctx = ipv6_pdp_find(gtp, &ip6h->daddr);
1230
1231 if (!pctx) {
1232 netdev_dbg(dev, "no PDP ctx found for %pI6, skip\n",
1233 &ip6h->daddr);
1234 return -ENOENT;
1235 }
1236 netdev_dbg(dev, "found PDP context %p\n", pctx);
1237
1238 tos = ipv6_get_dsfield(ip6h);
1239
1240 switch (pctx->sk->sk_family) {
1241 case AF_INET:
1242 ret = gtp_build_skb_outer_ip4(skb, dev, pktinfo, pctx, tos, 0);
1243 break;
1244 case AF_INET6:
1245 ret = gtp_build_skb_outer_ip6(net, skb, dev, pktinfo, pctx, tos);
1246 break;
1247 default:
1248 ret = -1;
1249 WARN_ON_ONCE(1);
1250 break;
1251 }
1252
1253 if (ret < 0)
1254 return ret;
1255
1256 netdev_dbg(dev, "gtp -> IP src: %pI6 dst: %pI6\n",
1257 &ip6h->saddr, &ip6h->daddr);
1258
1259 return 0;
1260}
1261
1262static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
1263{
1264 unsigned int proto = ntohs(skb->protocol);
1265 struct gtp_pktinfo pktinfo;
1266 int err;
1267
1268 /* Ensure there is sufficient headroom. */
1269 if (skb_cow_head(skb, dev->needed_headroom))
1270 goto tx_err;
1271
1272 if (!pskb_inet_may_pull(skb))
1273 goto tx_err;
1274
1275 skb_reset_inner_headers(skb);
1276
1277 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
1278 rcu_read_lock();
1279 switch (proto) {
1280 case ETH_P_IP:
1281 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
1282 break;
1283 case ETH_P_IPV6:
1284 err = gtp_build_skb_ip6(skb, dev, &pktinfo);
1285 break;
1286 default:
1287 err = -EOPNOTSUPP;
1288 break;
1289 }
1290 rcu_read_unlock();
1291
1292 if (err < 0)
1293 goto tx_err;
1294
1295 switch (pktinfo.pctx->sk->sk_family) {
1296 case AF_INET:
1297 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
1298 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
1299 pktinfo.tos,
1300 ip4_dst_hoplimit(&pktinfo.rt->dst),
1301 0,
1302 pktinfo.gtph_port, pktinfo.gtph_port,
1303 !net_eq(sock_net(pktinfo.pctx->sk),
1304 dev_net(dev)),
1305 false);
1306 break;
1307 case AF_INET6:
1308#if IS_ENABLED(CONFIG_IPV6)
1309 udp_tunnel6_xmit_skb(&pktinfo.rt6->dst, pktinfo.sk, skb, dev,
1310 &pktinfo.fl6.saddr, &pktinfo.fl6.daddr,
1311 pktinfo.tos,
1312 ip6_dst_hoplimit(&pktinfo.rt->dst),
1313 0,
1314 pktinfo.gtph_port, pktinfo.gtph_port,
1315 false);
1316#else
1317 goto tx_err;
1318#endif
1319 break;
1320 }
1321
1322 return NETDEV_TX_OK;
1323tx_err:
1324 dev->stats.tx_errors++;
1325 dev_kfree_skb(skb);
1326 return NETDEV_TX_OK;
1327}
1328
1329static const struct net_device_ops gtp_netdev_ops = {
1330 .ndo_uninit = gtp_dev_uninit,
1331 .ndo_start_xmit = gtp_dev_xmit,
1332};
1333
1334static const struct device_type gtp_type = {
1335 .name = "gtp",
1336};
1337
1338#define GTP_TH_MAXLEN (sizeof(struct udphdr) + sizeof(struct gtp0_header))
1339#define GTP_IPV4_MAXLEN (sizeof(struct iphdr) + GTP_TH_MAXLEN)
1340
1341static void gtp_link_setup(struct net_device *dev)
1342{
1343 struct gtp_dev *gtp = netdev_priv(dev);
1344
1345 dev->netdev_ops = >p_netdev_ops;
1346 dev->needs_free_netdev = true;
1347 SET_NETDEV_DEVTYPE(dev, >p_type);
1348
1349 dev->hard_header_len = 0;
1350 dev->addr_len = 0;
1351 dev->mtu = ETH_DATA_LEN - GTP_IPV4_MAXLEN;
1352
1353 /* Zero header length. */
1354 dev->type = ARPHRD_NONE;
1355 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
1356
1357 dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
1358 dev->priv_flags |= IFF_NO_QUEUE;
1359 dev->lltx = true;
1360 netif_keep_dst(dev);
1361
1362 dev->needed_headroom = LL_MAX_HEADER + GTP_IPV4_MAXLEN;
1363 gtp->dev = dev;
1364}
1365
1366static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
1367static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
1368
1369static void gtp_destructor(struct net_device *dev)
1370{
1371 struct gtp_dev *gtp = netdev_priv(dev);
1372
1373 kfree(gtp->addr_hash);
1374 kfree(gtp->tid_hash);
1375}
1376
1377static int gtp_sock_udp_config(struct udp_port_cfg *udp_conf,
1378 const struct nlattr *nla, int family)
1379{
1380 udp_conf->family = family;
1381
1382 switch (udp_conf->family) {
1383 case AF_INET:
1384 udp_conf->local_ip.s_addr = nla_get_be32(nla);
1385 break;
1386#if IS_ENABLED(CONFIG_IPV6)
1387 case AF_INET6:
1388 udp_conf->local_ip6 = nla_get_in6_addr(nla);
1389 break;
1390#endif
1391 default:
1392 return -EOPNOTSUPP;
1393 }
1394
1395 return 0;
1396}
1397
1398static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp,
1399 const struct nlattr *nla, int family)
1400{
1401 struct udp_tunnel_sock_cfg tuncfg = {};
1402 struct udp_port_cfg udp_conf = {};
1403 struct net *net = gtp->net;
1404 struct socket *sock;
1405 int err;
1406
1407 if (nla) {
1408 err = gtp_sock_udp_config(&udp_conf, nla, family);
1409 if (err < 0)
1410 return ERR_PTR(err);
1411 } else {
1412 udp_conf.local_ip.s_addr = htonl(INADDR_ANY);
1413 udp_conf.family = AF_INET;
1414 }
1415
1416 if (type == UDP_ENCAP_GTP0)
1417 udp_conf.local_udp_port = htons(GTP0_PORT);
1418 else if (type == UDP_ENCAP_GTP1U)
1419 udp_conf.local_udp_port = htons(GTP1U_PORT);
1420 else
1421 return ERR_PTR(-EINVAL);
1422
1423 err = udp_sock_create(net, &udp_conf, &sock);
1424 if (err)
1425 return ERR_PTR(err);
1426
1427 tuncfg.sk_user_data = gtp;
1428 tuncfg.encap_type = type;
1429 tuncfg.encap_rcv = gtp_encap_recv;
1430 tuncfg.encap_destroy = NULL;
1431
1432 setup_udp_tunnel_sock(net, sock, &tuncfg);
1433
1434 return sock->sk;
1435}
1436
1437static int gtp_create_sockets(struct gtp_dev *gtp, const struct nlattr *nla,
1438 int family)
1439{
1440 struct sock *sk1u;
1441 struct sock *sk0;
1442
1443 sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp, nla, family);
1444 if (IS_ERR(sk0))
1445 return PTR_ERR(sk0);
1446
1447 sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp, nla, family);
1448 if (IS_ERR(sk1u)) {
1449 udp_tunnel_sock_release(sk0->sk_socket);
1450 return PTR_ERR(sk1u);
1451 }
1452
1453 gtp->sk_created = true;
1454 gtp->sk0 = sk0;
1455 gtp->sk1u = sk1u;
1456
1457 return 0;
1458}
1459
1460#define GTP_TH_MAXLEN (sizeof(struct udphdr) + sizeof(struct gtp0_header))
1461#define GTP_IPV6_MAXLEN (sizeof(struct ipv6hdr) + GTP_TH_MAXLEN)
1462
1463static int gtp_newlink(struct net *src_net, struct net_device *dev,
1464 struct nlattr *tb[], struct nlattr *data[],
1465 struct netlink_ext_ack *extack)
1466{
1467 unsigned int role = GTP_ROLE_GGSN;
1468 struct gtp_dev *gtp;
1469 struct gtp_net *gn;
1470 int hashsize, err;
1471
1472#if !IS_ENABLED(CONFIG_IPV6)
1473 if (data[IFLA_GTP_LOCAL6])
1474 return -EAFNOSUPPORT;
1475#endif
1476
1477 gtp = netdev_priv(dev);
1478
1479 if (!data[IFLA_GTP_PDP_HASHSIZE]) {
1480 hashsize = 1024;
1481 } else {
1482 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
1483 if (!hashsize)
1484 hashsize = 1024;
1485 }
1486
1487 if (data[IFLA_GTP_ROLE]) {
1488 role = nla_get_u32(data[IFLA_GTP_ROLE]);
1489 if (role > GTP_ROLE_SGSN)
1490 return -EINVAL;
1491 }
1492 gtp->role = role;
1493
1494 gtp->restart_count = nla_get_u8_default(data[IFLA_GTP_RESTART_COUNT],
1495 0);
1496
1497 gtp->net = src_net;
1498
1499 err = gtp_hashtable_new(gtp, hashsize);
1500 if (err < 0)
1501 return err;
1502
1503 if (data[IFLA_GTP_CREATE_SOCKETS]) {
1504 if (data[IFLA_GTP_LOCAL6])
1505 err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL6], AF_INET6);
1506 else
1507 err = gtp_create_sockets(gtp, data[IFLA_GTP_LOCAL], AF_INET);
1508 } else {
1509 err = gtp_encap_enable(gtp, data);
1510 }
1511
1512 if (err < 0)
1513 goto out_hashtable;
1514
1515 if ((gtp->sk0 && gtp->sk0->sk_family == AF_INET6) ||
1516 (gtp->sk1u && gtp->sk1u->sk_family == AF_INET6)) {
1517 dev->mtu = ETH_DATA_LEN - GTP_IPV6_MAXLEN;
1518 dev->needed_headroom = LL_MAX_HEADER + GTP_IPV6_MAXLEN;
1519 }
1520
1521 err = register_netdevice(dev);
1522 if (err < 0) {
1523 netdev_dbg(dev, "failed to register new netdev %d\n", err);
1524 goto out_encap;
1525 }
1526
1527 gn = net_generic(src_net, gtp_net_id);
1528 list_add(>p->list, &gn->gtp_dev_list);
1529 dev->priv_destructor = gtp_destructor;
1530
1531 netdev_dbg(dev, "registered new GTP interface\n");
1532
1533 return 0;
1534
1535out_encap:
1536 gtp_encap_disable(gtp);
1537out_hashtable:
1538 kfree(gtp->addr_hash);
1539 kfree(gtp->tid_hash);
1540 return err;
1541}
1542
1543static void gtp_dellink(struct net_device *dev, struct list_head *head)
1544{
1545 struct gtp_dev *gtp = netdev_priv(dev);
1546 struct hlist_node *next;
1547 struct pdp_ctx *pctx;
1548 int i;
1549
1550 for (i = 0; i < gtp->hash_size; i++)
1551 hlist_for_each_entry_safe(pctx, next, >p->tid_hash[i], hlist_tid)
1552 pdp_context_delete(pctx);
1553
1554 list_del(>p->list);
1555 unregister_netdevice_queue(dev, head);
1556}
1557
1558static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
1559 [IFLA_GTP_FD0] = { .type = NLA_U32 },
1560 [IFLA_GTP_FD1] = { .type = NLA_U32 },
1561 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
1562 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
1563 [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 },
1564 [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 },
1565 [IFLA_GTP_LOCAL] = { .type = NLA_U32 },
1566 [IFLA_GTP_LOCAL6] = { .len = sizeof(struct in6_addr) },
1567};
1568
1569static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
1570 struct netlink_ext_ack *extack)
1571{
1572 if (!data)
1573 return -EINVAL;
1574
1575 return 0;
1576}
1577
1578static size_t gtp_get_size(const struct net_device *dev)
1579{
1580 return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
1581 nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
1582 nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
1583}
1584
1585static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
1586{
1587 struct gtp_dev *gtp = netdev_priv(dev);
1588
1589 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
1590 goto nla_put_failure;
1591 if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
1592 goto nla_put_failure;
1593 if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
1594 goto nla_put_failure;
1595
1596 return 0;
1597
1598nla_put_failure:
1599 return -EMSGSIZE;
1600}
1601
1602static struct rtnl_link_ops gtp_link_ops __read_mostly = {
1603 .kind = "gtp",
1604 .maxtype = IFLA_GTP_MAX,
1605 .policy = gtp_policy,
1606 .priv_size = sizeof(struct gtp_dev),
1607 .setup = gtp_link_setup,
1608 .validate = gtp_validate,
1609 .newlink = gtp_newlink,
1610 .dellink = gtp_dellink,
1611 .get_size = gtp_get_size,
1612 .fill_info = gtp_fill_info,
1613};
1614
1615static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
1616{
1617 int i;
1618
1619 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1620 GFP_KERNEL | __GFP_NOWARN);
1621 if (gtp->addr_hash == NULL)
1622 return -ENOMEM;
1623
1624 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1625 GFP_KERNEL | __GFP_NOWARN);
1626 if (gtp->tid_hash == NULL)
1627 goto err1;
1628
1629 gtp->hash_size = hsize;
1630
1631 for (i = 0; i < hsize; i++) {
1632 INIT_HLIST_HEAD(>p->addr_hash[i]);
1633 INIT_HLIST_HEAD(>p->tid_hash[i]);
1634 }
1635 return 0;
1636err1:
1637 kfree(gtp->addr_hash);
1638 return -ENOMEM;
1639}
1640
1641static struct sock *gtp_encap_enable_socket(int fd, int type,
1642 struct gtp_dev *gtp)
1643{
1644 struct udp_tunnel_sock_cfg tuncfg = {NULL};
1645 struct socket *sock;
1646 struct sock *sk;
1647 int err;
1648
1649 pr_debug("enable gtp on %d, %d\n", fd, type);
1650
1651 sock = sockfd_lookup(fd, &err);
1652 if (!sock) {
1653 pr_debug("gtp socket fd=%d not found\n", fd);
1654 return ERR_PTR(err);
1655 }
1656
1657 sk = sock->sk;
1658 if (sk->sk_protocol != IPPROTO_UDP ||
1659 sk->sk_type != SOCK_DGRAM ||
1660 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
1661 pr_debug("socket fd=%d not UDP\n", fd);
1662 sk = ERR_PTR(-EINVAL);
1663 goto out_sock;
1664 }
1665
1666 if (sk->sk_family == AF_INET6 &&
1667 !sk->sk_ipv6only) {
1668 sk = ERR_PTR(-EADDRNOTAVAIL);
1669 goto out_sock;
1670 }
1671
1672 lock_sock(sk);
1673 if (sk->sk_user_data) {
1674 sk = ERR_PTR(-EBUSY);
1675 goto out_rel_sock;
1676 }
1677
1678 sock_hold(sk);
1679
1680 tuncfg.sk_user_data = gtp;
1681 tuncfg.encap_type = type;
1682 tuncfg.encap_rcv = gtp_encap_recv;
1683 tuncfg.encap_destroy = gtp_encap_destroy;
1684
1685 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
1686
1687out_rel_sock:
1688 release_sock(sock->sk);
1689out_sock:
1690 sockfd_put(sock);
1691 return sk;
1692}
1693
1694static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
1695{
1696 struct sock *sk1u = NULL;
1697 struct sock *sk0 = NULL;
1698
1699 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
1700 return -EINVAL;
1701
1702 if (data[IFLA_GTP_FD0]) {
1703 int fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
1704
1705 if (fd0 >= 0) {
1706 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
1707 if (IS_ERR(sk0))
1708 return PTR_ERR(sk0);
1709 }
1710 }
1711
1712 if (data[IFLA_GTP_FD1]) {
1713 int fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
1714
1715 if (fd1 >= 0) {
1716 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
1717 if (IS_ERR(sk1u)) {
1718 gtp_encap_disable_sock(sk0);
1719 return PTR_ERR(sk1u);
1720 }
1721 }
1722 }
1723
1724 gtp->sk0 = sk0;
1725 gtp->sk1u = sk1u;
1726
1727 if (sk0 && sk1u &&
1728 sk0->sk_family != sk1u->sk_family) {
1729 gtp_encap_disable_sock(sk0);
1730 gtp_encap_disable_sock(sk1u);
1731 return -EINVAL;
1732 }
1733
1734 return 0;
1735}
1736
1737static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
1738{
1739 struct gtp_dev *gtp = NULL;
1740 struct net_device *dev;
1741 struct net *net;
1742
1743 /* Examine the link attributes and figure out which network namespace
1744 * we are talking about.
1745 */
1746 if (nla[GTPA_NET_NS_FD])
1747 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
1748 else
1749 net = get_net(src_net);
1750
1751 if (IS_ERR(net))
1752 return NULL;
1753
1754 /* Check if there's an existing gtpX device to configure */
1755 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
1756 if (dev && dev->netdev_ops == >p_netdev_ops)
1757 gtp = netdev_priv(dev);
1758
1759 put_net(net);
1760 return gtp;
1761}
1762
1763static void gtp_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1764{
1765 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1766
1767 switch (pctx->gtp_version) {
1768 case GTP_V0:
1769 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
1770 * label needs to be the same for uplink and downlink packets,
1771 * so let's annotate this.
1772 */
1773 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
1774 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
1775 break;
1776 case GTP_V1:
1777 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
1778 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
1779 break;
1780 default:
1781 break;
1782 }
1783}
1784
1785static void ip_pdp_peer_fill(struct pdp_ctx *pctx, struct genl_info *info)
1786{
1787 if (info->attrs[GTPA_PEER_ADDRESS]) {
1788 pctx->peer.addr.s_addr =
1789 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1790 } else if (info->attrs[GTPA_PEER_ADDR6]) {
1791 pctx->peer.addr6 = nla_get_in6_addr(info->attrs[GTPA_PEER_ADDR6]);
1792 }
1793}
1794
1795static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1796{
1797 ip_pdp_peer_fill(pctx, info);
1798 pctx->ms.addr.s_addr =
1799 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1800 gtp_pdp_fill(pctx, info);
1801}
1802
1803static bool ipv6_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1804{
1805 ip_pdp_peer_fill(pctx, info);
1806 pctx->ms.addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
1807 if (pctx->ms.addr6.s6_addr32[2] ||
1808 pctx->ms.addr6.s6_addr32[3])
1809 return false;
1810
1811 gtp_pdp_fill(pctx, info);
1812
1813 return true;
1814}
1815
1816static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
1817 struct genl_info *info)
1818{
1819 struct pdp_ctx *pctx, *pctx_tid = NULL;
1820 struct net_device *dev = gtp->dev;
1821 u32 hash_ms, hash_tid = 0;
1822 struct in6_addr ms_addr6;
1823 unsigned int version;
1824 bool found = false;
1825 __be32 ms_addr;
1826 int family;
1827
1828 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1829
1830 family = nla_get_u8_default(info->attrs[GTPA_FAMILY], AF_INET);
1831
1832#if !IS_ENABLED(CONFIG_IPV6)
1833 if (family == AF_INET6)
1834 return ERR_PTR(-EAFNOSUPPORT);
1835#endif
1836 if (!info->attrs[GTPA_PEER_ADDRESS] &&
1837 !info->attrs[GTPA_PEER_ADDR6])
1838 return ERR_PTR(-EINVAL);
1839
1840 if ((info->attrs[GTPA_PEER_ADDRESS] &&
1841 sk->sk_family == AF_INET6) ||
1842 (info->attrs[GTPA_PEER_ADDR6] &&
1843 sk->sk_family == AF_INET))
1844 return ERR_PTR(-EAFNOSUPPORT);
1845
1846 switch (family) {
1847 case AF_INET:
1848 if (!info->attrs[GTPA_MS_ADDRESS] ||
1849 info->attrs[GTPA_MS_ADDR6])
1850 return ERR_PTR(-EINVAL);
1851
1852 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1853 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
1854 pctx = ipv4_pdp_find(gtp, ms_addr);
1855 break;
1856 case AF_INET6:
1857 if (!info->attrs[GTPA_MS_ADDR6] ||
1858 info->attrs[GTPA_MS_ADDRESS])
1859 return ERR_PTR(-EINVAL);
1860
1861 ms_addr6 = nla_get_in6_addr(info->attrs[GTPA_MS_ADDR6]);
1862 hash_ms = ipv6_hashfn(&ms_addr6) % gtp->hash_size;
1863 pctx = ipv6_pdp_find(gtp, &ms_addr6);
1864 break;
1865 default:
1866 return ERR_PTR(-EAFNOSUPPORT);
1867 }
1868 if (pctx)
1869 found = true;
1870 if (version == GTP_V0)
1871 pctx_tid = gtp0_pdp_find(gtp,
1872 nla_get_u64(info->attrs[GTPA_TID]),
1873 family);
1874 else if (version == GTP_V1)
1875 pctx_tid = gtp1_pdp_find(gtp,
1876 nla_get_u32(info->attrs[GTPA_I_TEI]),
1877 family);
1878 if (pctx_tid)
1879 found = true;
1880
1881 if (found) {
1882 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
1883 return ERR_PTR(-EEXIST);
1884 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
1885 return ERR_PTR(-EOPNOTSUPP);
1886
1887 if (pctx && pctx_tid)
1888 return ERR_PTR(-EEXIST);
1889 if (!pctx)
1890 pctx = pctx_tid;
1891
1892 switch (pctx->af) {
1893 case AF_INET:
1894 ipv4_pdp_fill(pctx, info);
1895 break;
1896 case AF_INET6:
1897 if (!ipv6_pdp_fill(pctx, info))
1898 return ERR_PTR(-EADDRNOTAVAIL);
1899 break;
1900 }
1901
1902 if (pctx->gtp_version == GTP_V0)
1903 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
1904 pctx->u.v0.tid, pctx);
1905 else if (pctx->gtp_version == GTP_V1)
1906 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
1907 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1908
1909 return pctx;
1910
1911 }
1912
1913 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
1914 if (pctx == NULL)
1915 return ERR_PTR(-ENOMEM);
1916
1917 sock_hold(sk);
1918 pctx->sk = sk;
1919 pctx->dev = gtp->dev;
1920 pctx->af = family;
1921
1922 switch (pctx->af) {
1923 case AF_INET:
1924 if (!info->attrs[GTPA_MS_ADDRESS]) {
1925 sock_put(sk);
1926 kfree(pctx);
1927 return ERR_PTR(-EINVAL);
1928 }
1929
1930 ipv4_pdp_fill(pctx, info);
1931 break;
1932 case AF_INET6:
1933 if (!info->attrs[GTPA_MS_ADDR6]) {
1934 sock_put(sk);
1935 kfree(pctx);
1936 return ERR_PTR(-EINVAL);
1937 }
1938
1939 if (!ipv6_pdp_fill(pctx, info)) {
1940 sock_put(sk);
1941 kfree(pctx);
1942 return ERR_PTR(-EADDRNOTAVAIL);
1943 }
1944 break;
1945 }
1946 atomic_set(&pctx->tx_seq, 0);
1947
1948 switch (pctx->gtp_version) {
1949 case GTP_V0:
1950 /* TS 09.60: "The flow label identifies unambiguously a GTP
1951 * flow.". We use the tid for this instead, I cannot find a
1952 * situation in which this doesn't unambiguosly identify the
1953 * PDP context.
1954 */
1955 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1956 break;
1957 case GTP_V1:
1958 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1959 break;
1960 }
1961
1962 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
1963 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1964
1965 switch (pctx->gtp_version) {
1966 case GTP_V0:
1967 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1968 pctx->u.v0.tid, &pctx->peer.addr,
1969 &pctx->ms.addr, pctx);
1970 break;
1971 case GTP_V1:
1972 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1973 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1974 &pctx->peer.addr, &pctx->ms.addr, pctx);
1975 break;
1976 }
1977
1978 return pctx;
1979}
1980
1981static void pdp_context_free(struct rcu_head *head)
1982{
1983 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1984
1985 sock_put(pctx->sk);
1986 kfree(pctx);
1987}
1988
1989static void pdp_context_delete(struct pdp_ctx *pctx)
1990{
1991 hlist_del_rcu(&pctx->hlist_tid);
1992 hlist_del_rcu(&pctx->hlist_addr);
1993 call_rcu(&pctx->rcu_head, pdp_context_free);
1994}
1995
1996static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1997
1998static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1999{
2000 unsigned int version;
2001 struct pdp_ctx *pctx;
2002 struct gtp_dev *gtp;
2003 struct sock *sk;
2004 int err;
2005
2006 if (!info->attrs[GTPA_VERSION] ||
2007 !info->attrs[GTPA_LINK])
2008 return -EINVAL;
2009
2010 version = nla_get_u32(info->attrs[GTPA_VERSION]);
2011
2012 switch (version) {
2013 case GTP_V0:
2014 if (!info->attrs[GTPA_TID] ||
2015 !info->attrs[GTPA_FLOW])
2016 return -EINVAL;
2017 break;
2018 case GTP_V1:
2019 if (!info->attrs[GTPA_I_TEI] ||
2020 !info->attrs[GTPA_O_TEI])
2021 return -EINVAL;
2022 break;
2023
2024 default:
2025 return -EINVAL;
2026 }
2027
2028 rtnl_lock();
2029
2030 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
2031 if (!gtp) {
2032 err = -ENODEV;
2033 goto out_unlock;
2034 }
2035
2036 if (version == GTP_V0)
2037 sk = gtp->sk0;
2038 else if (version == GTP_V1)
2039 sk = gtp->sk1u;
2040 else
2041 sk = NULL;
2042
2043 if (!sk) {
2044 err = -ENODEV;
2045 goto out_unlock;
2046 }
2047
2048 pctx = gtp_pdp_add(gtp, sk, info);
2049 if (IS_ERR(pctx)) {
2050 err = PTR_ERR(pctx);
2051 } else {
2052 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
2053 err = 0;
2054 }
2055
2056out_unlock:
2057 rtnl_unlock();
2058 return err;
2059}
2060
2061static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
2062 struct nlattr *nla[])
2063{
2064 struct gtp_dev *gtp;
2065 int family;
2066
2067 family = nla_get_u8_default(nla[GTPA_FAMILY], AF_INET);
2068
2069 gtp = gtp_find_dev(net, nla);
2070 if (!gtp)
2071 return ERR_PTR(-ENODEV);
2072
2073 if (nla[GTPA_MS_ADDRESS]) {
2074 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
2075
2076 if (family != AF_INET)
2077 return ERR_PTR(-EINVAL);
2078
2079 return ipv4_pdp_find(gtp, ip);
2080 } else if (nla[GTPA_MS_ADDR6]) {
2081 struct in6_addr addr = nla_get_in6_addr(nla[GTPA_MS_ADDR6]);
2082
2083 if (family != AF_INET6)
2084 return ERR_PTR(-EINVAL);
2085
2086 if (addr.s6_addr32[2] ||
2087 addr.s6_addr32[3])
2088 return ERR_PTR(-EADDRNOTAVAIL);
2089
2090 return ipv6_pdp_find(gtp, &addr);
2091 } else if (nla[GTPA_VERSION]) {
2092 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
2093
2094 if (gtp_version == GTP_V0 && nla[GTPA_TID]) {
2095 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]),
2096 family);
2097 } else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) {
2098 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]),
2099 family);
2100 }
2101 }
2102
2103 return ERR_PTR(-EINVAL);
2104}
2105
2106static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
2107{
2108 struct pdp_ctx *pctx;
2109
2110 if (nla[GTPA_LINK])
2111 pctx = gtp_find_pdp_by_link(net, nla);
2112 else
2113 pctx = ERR_PTR(-EINVAL);
2114
2115 if (!pctx)
2116 pctx = ERR_PTR(-ENOENT);
2117
2118 return pctx;
2119}
2120
2121static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
2122{
2123 struct pdp_ctx *pctx;
2124 int err = 0;
2125
2126 if (!info->attrs[GTPA_VERSION])
2127 return -EINVAL;
2128
2129 rcu_read_lock();
2130
2131 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
2132 if (IS_ERR(pctx)) {
2133 err = PTR_ERR(pctx);
2134 goto out_unlock;
2135 }
2136
2137 if (pctx->gtp_version == GTP_V0)
2138 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
2139 pctx->u.v0.tid, pctx);
2140 else if (pctx->gtp_version == GTP_V1)
2141 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
2142 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
2143
2144 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
2145 pdp_context_delete(pctx);
2146
2147out_unlock:
2148 rcu_read_unlock();
2149 return err;
2150}
2151
2152static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
2153 int flags, u32 type, struct pdp_ctx *pctx)
2154{
2155 void *genlh;
2156
2157 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
2158 type);
2159 if (genlh == NULL)
2160 goto nlmsg_failure;
2161
2162 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
2163 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
2164 nla_put_u8(skb, GTPA_FAMILY, pctx->af))
2165 goto nla_put_failure;
2166
2167 switch (pctx->af) {
2168 case AF_INET:
2169 if (nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms.addr.s_addr))
2170 goto nla_put_failure;
2171 break;
2172 case AF_INET6:
2173 if (nla_put_in6_addr(skb, GTPA_MS_ADDR6, &pctx->ms.addr6))
2174 goto nla_put_failure;
2175 break;
2176 }
2177
2178 switch (pctx->sk->sk_family) {
2179 case AF_INET:
2180 if (nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer.addr.s_addr))
2181 goto nla_put_failure;
2182 break;
2183 case AF_INET6:
2184 if (nla_put_in6_addr(skb, GTPA_PEER_ADDR6, &pctx->peer.addr6))
2185 goto nla_put_failure;
2186 break;
2187 }
2188
2189 switch (pctx->gtp_version) {
2190 case GTP_V0:
2191 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
2192 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
2193 goto nla_put_failure;
2194 break;
2195 case GTP_V1:
2196 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
2197 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
2198 goto nla_put_failure;
2199 break;
2200 }
2201 genlmsg_end(skb, genlh);
2202 return 0;
2203
2204nlmsg_failure:
2205nla_put_failure:
2206 genlmsg_cancel(skb, genlh);
2207 return -EMSGSIZE;
2208}
2209
2210static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
2211{
2212 struct sk_buff *msg;
2213 int ret;
2214
2215 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
2216 if (!msg)
2217 return -ENOMEM;
2218
2219 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
2220 if (ret < 0) {
2221 nlmsg_free(msg);
2222 return ret;
2223 }
2224
2225 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg,
2226 0, GTP_GENL_MCGRP, GFP_ATOMIC);
2227 return ret;
2228}
2229
2230static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
2231{
2232 struct pdp_ctx *pctx = NULL;
2233 struct sk_buff *skb2;
2234 int err;
2235
2236 if (!info->attrs[GTPA_VERSION])
2237 return -EINVAL;
2238
2239 rcu_read_lock();
2240
2241 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
2242 if (IS_ERR(pctx)) {
2243 err = PTR_ERR(pctx);
2244 goto err_unlock;
2245 }
2246
2247 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
2248 if (skb2 == NULL) {
2249 err = -ENOMEM;
2250 goto err_unlock;
2251 }
2252
2253 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
2254 0, info->nlhdr->nlmsg_type, pctx);
2255 if (err < 0)
2256 goto err_unlock_free;
2257
2258 rcu_read_unlock();
2259 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
2260
2261err_unlock_free:
2262 kfree_skb(skb2);
2263err_unlock:
2264 rcu_read_unlock();
2265 return err;
2266}
2267
2268static int gtp_genl_dump_pdp(struct sk_buff *skb,
2269 struct netlink_callback *cb)
2270{
2271 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
2272 int i, j, bucket = cb->args[0], skip = cb->args[1];
2273 struct net *net = sock_net(skb->sk);
2274 struct net_device *dev;
2275 struct pdp_ctx *pctx;
2276
2277 if (cb->args[4])
2278 return 0;
2279
2280 rcu_read_lock();
2281 for_each_netdev_rcu(net, dev) {
2282 if (dev->rtnl_link_ops != >p_link_ops)
2283 continue;
2284
2285 gtp = netdev_priv(dev);
2286
2287 if (last_gtp && last_gtp != gtp)
2288 continue;
2289 else
2290 last_gtp = NULL;
2291
2292 for (i = bucket; i < gtp->hash_size; i++) {
2293 j = 0;
2294 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
2295 hlist_tid) {
2296 if (j >= skip &&
2297 gtp_genl_fill_info(skb,
2298 NETLINK_CB(cb->skb).portid,
2299 cb->nlh->nlmsg_seq,
2300 NLM_F_MULTI,
2301 cb->nlh->nlmsg_type, pctx)) {
2302 cb->args[0] = i;
2303 cb->args[1] = j;
2304 cb->args[2] = (unsigned long)gtp;
2305 goto out;
2306 }
2307 j++;
2308 }
2309 skip = 0;
2310 }
2311 bucket = 0;
2312 }
2313 cb->args[4] = 1;
2314out:
2315 rcu_read_unlock();
2316 return skb->len;
2317}
2318
2319static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
2320{
2321 struct sk_buff *skb_to_send;
2322 __be32 src_ip, dst_ip;
2323 unsigned int version;
2324 struct gtp_dev *gtp;
2325 struct flowi4 fl4;
2326 struct rtable *rt;
2327 struct sock *sk;
2328 __be16 port;
2329 int len;
2330
2331 if (!info->attrs[GTPA_VERSION] ||
2332 !info->attrs[GTPA_LINK] ||
2333 !info->attrs[GTPA_PEER_ADDRESS] ||
2334 !info->attrs[GTPA_MS_ADDRESS])
2335 return -EINVAL;
2336
2337 version = nla_get_u32(info->attrs[GTPA_VERSION]);
2338 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
2339 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
2340
2341 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
2342 if (!gtp)
2343 return -ENODEV;
2344
2345 if (!gtp->sk_created)
2346 return -EOPNOTSUPP;
2347 if (!(gtp->dev->flags & IFF_UP))
2348 return -ENETDOWN;
2349
2350 if (version == GTP_V0) {
2351 struct gtp0_header *gtp0_h;
2352
2353 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
2354 sizeof(struct iphdr) + sizeof(struct udphdr);
2355
2356 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2357 if (!skb_to_send)
2358 return -ENOMEM;
2359
2360 sk = gtp->sk0;
2361 port = htons(GTP0_PORT);
2362
2363 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
2364 memset(gtp0_h, 0, sizeof(struct gtp0_header));
2365 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
2366 } else if (version == GTP_V1) {
2367 struct gtp1_header_long *gtp1u_h;
2368
2369 len = LL_RESERVED_SPACE(gtp->dev) +
2370 sizeof(struct gtp1_header_long) +
2371 sizeof(struct iphdr) + sizeof(struct udphdr);
2372
2373 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2374 if (!skb_to_send)
2375 return -ENOMEM;
2376
2377 sk = gtp->sk1u;
2378 port = htons(GTP1U_PORT);
2379
2380 gtp1u_h = skb_push(skb_to_send,
2381 sizeof(struct gtp1_header_long));
2382 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
2383 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
2384 } else {
2385 return -ENODEV;
2386 }
2387
2388 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
2389 if (IS_ERR(rt)) {
2390 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
2391 &dst_ip);
2392 kfree_skb(skb_to_send);
2393 return -ENODEV;
2394 }
2395
2396 udp_tunnel_xmit_skb(rt, sk, skb_to_send,
2397 fl4.saddr, fl4.daddr,
2398 fl4.flowi4_tos,
2399 ip4_dst_hoplimit(&rt->dst),
2400 0,
2401 port, port,
2402 !net_eq(sock_net(sk),
2403 dev_net(gtp->dev)),
2404 false);
2405 return 0;
2406}
2407
2408static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
2409 [GTPA_LINK] = { .type = NLA_U32, },
2410 [GTPA_VERSION] = { .type = NLA_U32, },
2411 [GTPA_TID] = { .type = NLA_U64, },
2412 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
2413 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
2414 [GTPA_FLOW] = { .type = NLA_U16, },
2415 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
2416 [GTPA_I_TEI] = { .type = NLA_U32, },
2417 [GTPA_O_TEI] = { .type = NLA_U32, },
2418 [GTPA_PEER_ADDR6] = { .len = sizeof(struct in6_addr), },
2419 [GTPA_MS_ADDR6] = { .len = sizeof(struct in6_addr), },
2420 [GTPA_FAMILY] = { .type = NLA_U8, },
2421};
2422
2423static const struct genl_small_ops gtp_genl_ops[] = {
2424 {
2425 .cmd = GTP_CMD_NEWPDP,
2426 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2427 .doit = gtp_genl_new_pdp,
2428 .flags = GENL_ADMIN_PERM,
2429 },
2430 {
2431 .cmd = GTP_CMD_DELPDP,
2432 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2433 .doit = gtp_genl_del_pdp,
2434 .flags = GENL_ADMIN_PERM,
2435 },
2436 {
2437 .cmd = GTP_CMD_GETPDP,
2438 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2439 .doit = gtp_genl_get_pdp,
2440 .dumpit = gtp_genl_dump_pdp,
2441 .flags = GENL_ADMIN_PERM,
2442 },
2443 {
2444 .cmd = GTP_CMD_ECHOREQ,
2445 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2446 .doit = gtp_genl_send_echo_req,
2447 .flags = GENL_ADMIN_PERM,
2448 },
2449};
2450
2451static struct genl_family gtp_genl_family __ro_after_init = {
2452 .name = "gtp",
2453 .version = 0,
2454 .hdrsize = 0,
2455 .maxattr = GTPA_MAX,
2456 .policy = gtp_genl_policy,
2457 .netnsok = true,
2458 .module = THIS_MODULE,
2459 .small_ops = gtp_genl_ops,
2460 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
2461 .resv_start_op = GTP_CMD_ECHOREQ + 1,
2462 .mcgrps = gtp_genl_mcgrps,
2463 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
2464};
2465
2466static int __net_init gtp_net_init(struct net *net)
2467{
2468 struct gtp_net *gn = net_generic(net, gtp_net_id);
2469
2470 INIT_LIST_HEAD(&gn->gtp_dev_list);
2471 return 0;
2472}
2473
2474static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list,
2475 struct list_head *dev_to_kill)
2476{
2477 struct net *net;
2478
2479 list_for_each_entry(net, net_list, exit_list) {
2480 struct gtp_net *gn = net_generic(net, gtp_net_id);
2481 struct gtp_dev *gtp, *gtp_next;
2482
2483 list_for_each_entry_safe(gtp, gtp_next, &gn->gtp_dev_list, list)
2484 gtp_dellink(gtp->dev, dev_to_kill);
2485 }
2486}
2487
2488static struct pernet_operations gtp_net_ops = {
2489 .init = gtp_net_init,
2490 .exit_batch_rtnl = gtp_net_exit_batch_rtnl,
2491 .id = >p_net_id,
2492 .size = sizeof(struct gtp_net),
2493};
2494
2495static int __init gtp_init(void)
2496{
2497 int err;
2498
2499 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
2500
2501 err = register_pernet_subsys(>p_net_ops);
2502 if (err < 0)
2503 goto error_out;
2504
2505 err = rtnl_link_register(>p_link_ops);
2506 if (err < 0)
2507 goto unreg_pernet_subsys;
2508
2509 err = genl_register_family(>p_genl_family);
2510 if (err < 0)
2511 goto unreg_rtnl_link;
2512
2513 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
2514 sizeof(struct pdp_ctx));
2515 return 0;
2516
2517unreg_rtnl_link:
2518 rtnl_link_unregister(>p_link_ops);
2519unreg_pernet_subsys:
2520 unregister_pernet_subsys(>p_net_ops);
2521error_out:
2522 pr_err("error loading GTP module loaded\n");
2523 return err;
2524}
2525late_initcall(gtp_init);
2526
2527static void __exit gtp_fini(void)
2528{
2529 genl_unregister_family(>p_genl_family);
2530 rtnl_link_unregister(>p_link_ops);
2531 unregister_pernet_subsys(>p_net_ops);
2532
2533 pr_info("GTP module unloaded\n");
2534}
2535module_exit(gtp_fini);
2536
2537MODULE_LICENSE("GPL");
2538MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
2539MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
2540MODULE_ALIAS_RTNL_LINK("gtp");
2541MODULE_ALIAS_GENL_FAMILY("gtp");