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Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...
[drm/drm-misc.git] / drivers / net / gtp.c
blob89a996ad8cd016e12a42e0f49f4624b40f3549cd
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. */
37 struct 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. */
71 struct 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
89 struct 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
101 static unsigned int gtp_net_id __read_mostly;
102
103 struct gtp_net {
104 struct list_head gtp_dev_list;
105 };
106
107 static u32 gtp_h_initval;
108
109 static struct genl_family gtp_genl_family;
110
111 enum gtp_multicast_groups {
112 GTP_GENL_MCGRP,
113 };
114
115 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
116 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
117 };
118
119 static void pdp_context_delete(struct pdp_ctx *pctx);
120
121 static 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
127 static inline u32 gtp1u_hashfn(u32 tid)
128 {
129 return jhash_1word(tid, gtp_h_initval);
130 }
131
132 static inline u32 ipv4_hashfn(__be32 ip)
133 {
134 return jhash_1word((__force u32)ip, gtp_h_initval);
135 }
136
137 static 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. */
144 static 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 = &gtp->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. */
161 static 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 = &gtp->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. */
178 static 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 = &gtp->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 */
205 static 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
212 static 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 = &gtp->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
229 static 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
245 static 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 */
272 static 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
285 static 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
309 static 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
340 err:
341 pctx->dev->stats.rx_dropped++;
342 return -1;
343 }
344
345 static 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
360 static 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 */
391 static 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 */
398 static 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
423 static 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
452 static 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(&gtp_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
494 static 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, &gtp_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
512 failure:
513 genlmsg_cancel(skb, genlh);
514 return -EMSGSIZE;
515 }
516
517 static 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
526 static 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(&gtp_genl_family, dev_net(gtp->dev),
557 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
558 }
559
560 static 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. */
576 static 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 */
621 static 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
650 static 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(&gtp_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
709 static 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(&gtp_genl_family, dev_net(gtp->dev),
742 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
743 }
744
745 static 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
782 static 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
845 static 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
865 static void gtp_encap_destroy(struct sock *sk)
866 {
867 rtnl_lock();
868 __gtp_encap_destroy(sk);
869 rtnl_unlock();
870 }
871
872 static void gtp_encap_disable_sock(struct sock *sk)
873 {
874 if (!sk)
875 return;
876
877 __gtp_encap_destroy(sk);
878 }
879
880 static 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 */
897 static 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
937 static 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
944 static 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
961 static 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
984 struct 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
1000 static 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
1014 static 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
1028 static 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
1042 static 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;
1100 err_rt:
1101 ip_rt_put(rt);
1102 err:
1103 return -EBADMSG;
1104 }
1105
1106 static 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;
1157 err_rt:
1158 dst_release(dst);
1159 err:
1160 return -EBADMSG;
1161 }
1162
1163 static 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
1212 static 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
1262 static 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;
1323 tx_err:
1324 dev->stats.tx_errors++;
1325 dev_kfree_skb(skb);
1326 return NETDEV_TX_OK;
1327 }
1328
1329 static const struct net_device_ops gtp_netdev_ops = {
1330 .ndo_uninit = gtp_dev_uninit,
1331 .ndo_start_xmit = gtp_dev_xmit,
1332 };
1333
1334 static 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
1341 static void gtp_link_setup(struct net_device *dev)
1342 {
1343 struct gtp_dev *gtp = netdev_priv(dev);
1344
1345 dev->netdev_ops = &gtp_netdev_ops;
1346 dev->needs_free_netdev = true;
1347 SET_NETDEV_DEVTYPE(dev, &gtp_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
1366 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
1367 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
1368
1369 static 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
1377 static 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
1398 static 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
1437 static 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
1463 static 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(dev_net(dev), gtp_net_id);
1528 list_add_rcu(&gtp->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
1535 out_encap:
1536 gtp_encap_disable(gtp);
1537 out_hashtable:
1538 kfree(gtp->addr_hash);
1539 kfree(gtp->tid_hash);
1540 return err;
1541 }
1542
1543 static 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, &gtp->tid_hash[i], hlist_tid)
1552 pdp_context_delete(pctx);
1553
1554 list_del_rcu(&gtp->list);
1555 unregister_netdevice_queue(dev, head);
1556 }
1557
1558 static 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
1569 static 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
1578 static 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
1585 static 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
1598 nla_put_failure:
1599 return -EMSGSIZE;
1600 }
1601
1602 static 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
1615 static 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(&gtp->addr_hash[i]);
1633 INIT_HLIST_HEAD(&gtp->tid_hash[i]);
1634 }
1635 return 0;
1636 err1:
1637 kfree(gtp->addr_hash);
1638 return -ENOMEM;
1639 }
1640
1641 static 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
1687 out_rel_sock:
1688 release_sock(sock->sk);
1689 out_sock:
1690 sockfd_put(sock);
1691 return sk;
1692 }
1693
1694 static 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
1737 static 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 == &gtp_netdev_ops)
1757 gtp = netdev_priv(dev);
1758
1759 put_net(net);
1760 return gtp;
1761 }
1762
1763 static 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
1785 static 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
1795 static 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
1803 static 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
1816 static 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, &gtp->addr_hash[hash_ms]);
1963 hlist_add_head_rcu(&pctx->hlist_tid, &gtp->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
1981 static 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
1989 static 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
1996 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1997
1998 static 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
2056 out_unlock:
2057 rtnl_unlock();
2058 return err;
2059 }
2060
2061 static 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
2106 static 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
2121 static 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
2147 out_unlock:
2148 rcu_read_unlock();
2149 return err;
2150 }
2151
2152 static 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, &gtp_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
2204 nlmsg_failure:
2205 nla_put_failure:
2206 genlmsg_cancel(skb, genlh);
2207 return -EMSGSIZE;
2208 }
2209
2210 static 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(&gtp_genl_family, dev_net(pctx->dev), msg,
2226 0, GTP_GENL_MCGRP, GFP_ATOMIC);
2227 return ret;
2228 }
2229
2230 static 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
2261 err_unlock_free:
2262 kfree_skb(skb2);
2263 err_unlock:
2264 rcu_read_unlock();
2265 return err;
2266 }
2267
2268 static 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 pdp_ctx *pctx;
2275 struct gtp_net *gn;
2276
2277 gn = net_generic(net, gtp_net_id);
2278
2279 if (cb->args[4])
2280 return 0;
2281
2282 rcu_read_lock();
2283 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
2284 if (last_gtp && last_gtp != gtp)
2285 continue;
2286 else
2287 last_gtp = NULL;
2288
2289 for (i = bucket; i < gtp->hash_size; i++) {
2290 j = 0;
2291 hlist_for_each_entry_rcu(pctx, &gtp->tid_hash[i],
2292 hlist_tid) {
2293 if (j >= skip &&
2294 gtp_genl_fill_info(skb,
2295 NETLINK_CB(cb->skb).portid,
2296 cb->nlh->nlmsg_seq,
2297 NLM_F_MULTI,
2298 cb->nlh->nlmsg_type, pctx)) {
2299 cb->args[0] = i;
2300 cb->args[1] = j;
2301 cb->args[2] = (unsigned long)gtp;
2302 goto out;
2303 }
2304 j++;
2305 }
2306 skip = 0;
2307 }
2308 bucket = 0;
2309 }
2310 cb->args[4] = 1;
2311 out:
2312 rcu_read_unlock();
2313 return skb->len;
2314 }
2315
2316 static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
2317 {
2318 struct sk_buff *skb_to_send;
2319 __be32 src_ip, dst_ip;
2320 unsigned int version;
2321 struct gtp_dev *gtp;
2322 struct flowi4 fl4;
2323 struct rtable *rt;
2324 struct sock *sk;
2325 __be16 port;
2326 int len;
2327
2328 if (!info->attrs[GTPA_VERSION] ||
2329 !info->attrs[GTPA_LINK] ||
2330 !info->attrs[GTPA_PEER_ADDRESS] ||
2331 !info->attrs[GTPA_MS_ADDRESS])
2332 return -EINVAL;
2333
2334 version = nla_get_u32(info->attrs[GTPA_VERSION]);
2335 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
2336 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
2337
2338 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
2339 if (!gtp)
2340 return -ENODEV;
2341
2342 if (!gtp->sk_created)
2343 return -EOPNOTSUPP;
2344 if (!(gtp->dev->flags & IFF_UP))
2345 return -ENETDOWN;
2346
2347 if (version == GTP_V0) {
2348 struct gtp0_header *gtp0_h;
2349
2350 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
2351 sizeof(struct iphdr) + sizeof(struct udphdr);
2352
2353 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2354 if (!skb_to_send)
2355 return -ENOMEM;
2356
2357 sk = gtp->sk0;
2358 port = htons(GTP0_PORT);
2359
2360 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
2361 memset(gtp0_h, 0, sizeof(struct gtp0_header));
2362 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
2363 } else if (version == GTP_V1) {
2364 struct gtp1_header_long *gtp1u_h;
2365
2366 len = LL_RESERVED_SPACE(gtp->dev) +
2367 sizeof(struct gtp1_header_long) +
2368 sizeof(struct iphdr) + sizeof(struct udphdr);
2369
2370 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
2371 if (!skb_to_send)
2372 return -ENOMEM;
2373
2374 sk = gtp->sk1u;
2375 port = htons(GTP1U_PORT);
2376
2377 gtp1u_h = skb_push(skb_to_send,
2378 sizeof(struct gtp1_header_long));
2379 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
2380 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
2381 } else {
2382 return -ENODEV;
2383 }
2384
2385 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
2386 if (IS_ERR(rt)) {
2387 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
2388 &dst_ip);
2389 kfree_skb(skb_to_send);
2390 return -ENODEV;
2391 }
2392
2393 udp_tunnel_xmit_skb(rt, sk, skb_to_send,
2394 fl4.saddr, fl4.daddr,
2395 fl4.flowi4_tos,
2396 ip4_dst_hoplimit(&rt->dst),
2397 0,
2398 port, port,
2399 !net_eq(sock_net(sk),
2400 dev_net(gtp->dev)),
2401 false);
2402 return 0;
2403 }
2404
2405 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
2406 [GTPA_LINK] = { .type = NLA_U32, },
2407 [GTPA_VERSION] = { .type = NLA_U32, },
2408 [GTPA_TID] = { .type = NLA_U64, },
2409 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
2410 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
2411 [GTPA_FLOW] = { .type = NLA_U16, },
2412 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
2413 [GTPA_I_TEI] = { .type = NLA_U32, },
2414 [GTPA_O_TEI] = { .type = NLA_U32, },
2415 [GTPA_PEER_ADDR6] = { .len = sizeof(struct in6_addr), },
2416 [GTPA_MS_ADDR6] = { .len = sizeof(struct in6_addr), },
2417 [GTPA_FAMILY] = { .type = NLA_U8, },
2418 };
2419
2420 static const struct genl_small_ops gtp_genl_ops[] = {
2421 {
2422 .cmd = GTP_CMD_NEWPDP,
2423 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2424 .doit = gtp_genl_new_pdp,
2425 .flags = GENL_ADMIN_PERM,
2426 },
2427 {
2428 .cmd = GTP_CMD_DELPDP,
2429 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2430 .doit = gtp_genl_del_pdp,
2431 .flags = GENL_ADMIN_PERM,
2432 },
2433 {
2434 .cmd = GTP_CMD_GETPDP,
2435 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2436 .doit = gtp_genl_get_pdp,
2437 .dumpit = gtp_genl_dump_pdp,
2438 .flags = GENL_ADMIN_PERM,
2439 },
2440 {
2441 .cmd = GTP_CMD_ECHOREQ,
2442 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2443 .doit = gtp_genl_send_echo_req,
2444 .flags = GENL_ADMIN_PERM,
2445 },
2446 };
2447
2448 static struct genl_family gtp_genl_family __ro_after_init = {
2449 .name = "gtp",
2450 .version = 0,
2451 .hdrsize = 0,
2452 .maxattr = GTPA_MAX,
2453 .policy = gtp_genl_policy,
2454 .netnsok = true,
2455 .module = THIS_MODULE,
2456 .small_ops = gtp_genl_ops,
2457 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
2458 .resv_start_op = GTP_CMD_ECHOREQ + 1,
2459 .mcgrps = gtp_genl_mcgrps,
2460 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
2461 };
2462
2463 static int __net_init gtp_net_init(struct net *net)
2464 {
2465 struct gtp_net *gn = net_generic(net, gtp_net_id);
2466
2467 INIT_LIST_HEAD(&gn->gtp_dev_list);
2468 return 0;
2469 }
2470
2471 static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list,
2472 struct list_head *dev_to_kill)
2473 {
2474 struct net *net;
2475
2476 list_for_each_entry(net, net_list, exit_list) {
2477 struct gtp_net *gn = net_generic(net, gtp_net_id);
2478 struct gtp_dev *gtp;
2479
2480 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
2481 gtp_dellink(gtp->dev, dev_to_kill);
2482 }
2483 }
2484
2485 static struct pernet_operations gtp_net_ops = {
2486 .init = gtp_net_init,
2487 .exit_batch_rtnl = gtp_net_exit_batch_rtnl,
2488 .id = &gtp_net_id,
2489 .size = sizeof(struct gtp_net),
2490 };
2491
2492 static int __init gtp_init(void)
2493 {
2494 int err;
2495
2496 get_random_bytes(&gtp_h_initval, sizeof(gtp_h_initval));
2497
2498 err = register_pernet_subsys(&gtp_net_ops);
2499 if (err < 0)
2500 goto error_out;
2501
2502 err = rtnl_link_register(&gtp_link_ops);
2503 if (err < 0)
2504 goto unreg_pernet_subsys;
2505
2506 err = genl_register_family(&gtp_genl_family);
2507 if (err < 0)
2508 goto unreg_rtnl_link;
2509
2510 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
2511 sizeof(struct pdp_ctx));
2512 return 0;
2513
2514 unreg_rtnl_link:
2515 rtnl_link_unregister(&gtp_link_ops);
2516 unreg_pernet_subsys:
2517 unregister_pernet_subsys(&gtp_net_ops);
2518 error_out:
2519 pr_err("error loading GTP module loaded\n");
2520 return err;
2521 }
2522 late_initcall(gtp_init);
2523
2524 static void __exit gtp_fini(void)
2525 {
2526 genl_unregister_family(&gtp_genl_family);
2527 rtnl_link_unregister(&gtp_link_ops);
2528 unregister_pernet_subsys(&gtp_net_ops);
2529
2530 pr_info("GTP module unloaded\n");
2531 }
2532 module_exit(gtp_fini);
2533
2534 MODULE_LICENSE("GPL");
2535 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
2536 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
2537 MODULE_ALIAS_RTNL_LINK("gtp");
2538 MODULE_ALIAS_GENL_FAMILY("gtp");
Kernel DRM miscellaneous fixes and cross-tree changes