1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060
3 *
4 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
5 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
6 *
7 * Author: Harald Welte <hwelte@sysmocom.de>
8 * Pablo Neira Ayuso <pablo@netfilter.org>
9 * Andreas Schultz <aschultz@travelping.com>
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/udp.h>
17 #include <linux/rculist.h>
18 #include <linux/jhash.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/net.h>
21 #include <linux/file.h>
22 #include <linux/gtp.h>
23
24 #include <net/net_namespace.h>
25 #include <net/protocol.h>
26 #include <net/ip.h>
27 #include <net/udp.h>
28 #include <net/udp_tunnel.h>
29 #include <net/icmp.h>
30 #include <net/xfrm.h>
31 #include <net/genetlink.h>
32 #include <net/netns/generic.h>
33 #include <net/gtp.h>
34
35 /* An active session for the subscriber. */
36 struct pdp_ctx {
37 struct hlist_node hlist_tid;
38 struct hlist_node hlist_addr;
39
40 union {
41 struct {
42 u64 tid;
43 u16 flow;
44 } v0;
45 struct {
46 u32 i_tei;
47 u32 o_tei;
48 } v1;
49 } u;
50 u8 gtp_version;
51 u16 af;
52
53 struct in_addr ms_addr_ip4;
54 struct in_addr peer_addr_ip4;
55
56 struct sock *sk;
57 struct net_device *dev;
58
59 atomic_t tx_seq;
60 struct rcu_head rcu_head;
61 };
62
63 /* One instance of the GTP device. */
64 struct gtp_dev {
65 struct list_head list;
66
67 struct sock *sk0;
68 struct sock *sk1u;
69 u8 sk_created;
70
71 struct net_device *dev;
72 struct net *net;
73
74 unsigned int role;
75 unsigned int hash_size;
76 struct hlist_head *tid_hash;
77 struct hlist_head *addr_hash;
78
79 u8 restart_count;
80 };
81
82 struct echo_info {
83 struct in_addr ms_addr_ip4;
84 struct in_addr peer_addr_ip4;
85 u8 gtp_version;
86 };
87
88 static unsigned int gtp_net_id __read_mostly;
89
90 struct gtp_net {
91 struct list_head gtp_dev_list;
92 };
93
94 static u32 gtp_h_initval;
95
96 static struct genl_family gtp_genl_family;
97
98 enum gtp_multicast_groups {
99 GTP_GENL_MCGRP,
100 };
101
102 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
103 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
104 };
105
106 static void pdp_context_delete(struct pdp_ctx *pctx);
107
gtp0_hashfn(u64 tid)108 static inline u32 gtp0_hashfn(u64 tid)
109 {
110 u32 *tid32 = (u32 *) &tid;
111 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
112 }
113
gtp1u_hashfn(u32 tid)114 static inline u32 gtp1u_hashfn(u32 tid)
115 {
116 return jhash_1word(tid, gtp_h_initval);
117 }
118
ipv4_hashfn(__be32 ip)119 static inline u32 ipv4_hashfn(__be32 ip)
120 {
121 return jhash_1word((__force u32)ip, gtp_h_initval);
122 }
123
124 /* Resolve a PDP context structure based on the 64bit TID. */
gtp0_pdp_find(struct gtp_dev * gtp,u64 tid)125 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
126 {
127 struct hlist_head *head;
128 struct pdp_ctx *pdp;
129
130 head = >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. */
gtp1_pdp_find(struct gtp_dev * gtp,u32 tid)141 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
142 {
143 struct hlist_head *head;
144 struct pdp_ctx *pdp;
145
146 head = >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. */
ipv4_pdp_find(struct gtp_dev * gtp,__be32 ms_addr)157 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
158 {
159 struct hlist_head *head;
160 struct pdp_ctx *pdp;
161
162 head = >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
gtp_check_ms_ipv4(struct sk_buff * skb,struct pdp_ctx * pctx,unsigned int hdrlen,unsigned int role)173 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
174 unsigned int hdrlen, unsigned int role)
175 {
176 struct iphdr *iph;
177
178 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
179 return false;
180
181 iph = (struct iphdr *)(skb->data + hdrlen);
182
183 if (role == GTP_ROLE_SGSN)
184 return iph->daddr == pctx->ms_addr_ip4.s_addr;
185 else
186 return iph->saddr == pctx->ms_addr_ip4.s_addr;
187 }
188
189 /* Check if the inner IP address in this packet is assigned to any
190 * existing mobile subscriber.
191 */
gtp_check_ms(struct sk_buff * skb,struct pdp_ctx * pctx,unsigned int hdrlen,unsigned int role)192 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
193 unsigned int hdrlen, unsigned int role)
194 {
195 switch (ntohs(skb->protocol)) {
196 case ETH_P_IP:
197 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
198 }
199 return false;
200 }
201
gtp_rx(struct pdp_ctx * pctx,struct sk_buff * skb,unsigned int hdrlen,unsigned int role)202 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
203 unsigned int hdrlen, unsigned int role)
204 {
205 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
206 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
207 return 1;
208 }
209
210 /* Get rid of the GTP + UDP headers. */
211 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
212 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev)))) {
213 pctx->dev->stats.rx_length_errors++;
214 goto err;
215 }
216
217 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
218
219 /* Now that the UDP and the GTP header have been removed, set up the
220 * new network header. This is required by the upper layer to
221 * calculate the transport header.
222 */
223 skb_reset_network_header(skb);
224 skb_reset_mac_header(skb);
225
226 skb->dev = pctx->dev;
227
228 dev_sw_netstats_rx_add(pctx->dev, skb->len);
229
230 __netif_rx(skb);
231 return 0;
232
233 err:
234 pctx->dev->stats.rx_dropped++;
235 return -1;
236 }
237
ip4_route_output_gtp(struct flowi4 * fl4,const struct sock * sk,__be32 daddr,__be32 saddr)238 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
239 const struct sock *sk,
240 __be32 daddr, __be32 saddr)
241 {
242 memset(fl4, 0, sizeof(*fl4));
243 fl4->flowi4_oif = sk->sk_bound_dev_if;
244 fl4->daddr = daddr;
245 fl4->saddr = saddr;
246 fl4->flowi4_tos = ip_sock_rt_tos(sk);
247 fl4->flowi4_scope = ip_sock_rt_scope(sk);
248 fl4->flowi4_proto = sk->sk_protocol;
249
250 return ip_route_output_key(sock_net(sk), fl4);
251 }
252
253 /* GSM TS 09.60. 7.3
254 * In all Path Management messages:
255 * - TID: is not used and shall be set to 0.
256 * - Flow Label is not used and shall be set to 0
257 * In signalling messages:
258 * - number: this field is not yet used in signalling messages.
259 * It shall be set to 255 by the sender and shall be ignored
260 * by the receiver
261 * Returns true if the echo req was correct, false otherwise.
262 */
gtp0_validate_echo_hdr(struct gtp0_header * gtp0)263 static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0)
264 {
265 return !(gtp0->tid || (gtp0->flags ^ 0x1e) ||
266 gtp0->number != 0xff || gtp0->flow);
267 }
268
269 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
gtp0_build_echo_msg(struct gtp0_header * hdr,__u8 msg_type)270 static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type)
271 {
272 int len_pkt, len_hdr;
273
274 hdr->flags = 0x1e; /* v0, GTP-non-prime. */
275 hdr->type = msg_type;
276 /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID
277 * are not used and shall be set to 0.
278 */
279 hdr->flow = 0;
280 hdr->tid = 0;
281 hdr->number = 0xff;
282 hdr->spare[0] = 0xff;
283 hdr->spare[1] = 0xff;
284 hdr->spare[2] = 0xff;
285
286 len_pkt = sizeof(struct gtp0_packet);
287 len_hdr = sizeof(struct gtp0_header);
288
289 if (msg_type == GTP_ECHO_RSP)
290 hdr->length = htons(len_pkt - len_hdr);
291 else
292 hdr->length = 0;
293 }
294
gtp0_send_echo_resp(struct gtp_dev * gtp,struct sk_buff * skb)295 static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
296 {
297 struct gtp0_packet *gtp_pkt;
298 struct gtp0_header *gtp0;
299 struct rtable *rt;
300 struct flowi4 fl4;
301 struct iphdr *iph;
302 __be16 seq;
303
304 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
305
306 if (!gtp0_validate_echo_hdr(gtp0))
307 return -1;
308
309 seq = gtp0->seq;
310
311 /* pull GTP and UDP headers */
312 skb_pull_data(skb, sizeof(struct gtp0_header) + sizeof(struct udphdr));
313
314 gtp_pkt = skb_push(skb, sizeof(struct gtp0_packet));
315 memset(gtp_pkt, 0, sizeof(struct gtp0_packet));
316
317 gtp0_build_echo_msg(>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
gtp_genl_fill_echo(struct sk_buff * skb,u32 snd_portid,u32 snd_seq,int flags,u32 type,struct echo_info echo)352 static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
353 int flags, u32 type, struct echo_info echo)
354 {
355 void *genlh;
356
357 genlh = genlmsg_put(skb, snd_portid, snd_seq, >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
370 failure:
371 genlmsg_cancel(skb, genlh);
372 return -EMSGSIZE;
373 }
374
gtp0_handle_echo_resp(struct gtp_dev * gtp,struct sk_buff * skb)375 static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
376 {
377 struct gtp0_header *gtp0;
378 struct echo_info echo;
379 struct sk_buff *msg;
380 struct iphdr *iph;
381 int ret;
382
383 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
384
385 if (!gtp0_validate_echo_hdr(gtp0))
386 return -1;
387
388 iph = ip_hdr(skb);
389 echo.ms_addr_ip4.s_addr = iph->daddr;
390 echo.peer_addr_ip4.s_addr = iph->saddr;
391 echo.gtp_version = GTP_V0;
392
393 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
394 if (!msg)
395 return -ENOMEM;
396
397 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
398 if (ret < 0) {
399 nlmsg_free(msg);
400 return ret;
401 }
402
403 return genlmsg_multicast_netns(>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. */
gtp0_udp_encap_recv(struct gtp_dev * gtp,struct sk_buff * skb)408 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
409 {
410 unsigned int hdrlen = sizeof(struct udphdr) +
411 sizeof(struct gtp0_header);
412 struct gtp0_header *gtp0;
413 struct pdp_ctx *pctx;
414
415 if (!pskb_may_pull(skb, hdrlen))
416 return -1;
417
418 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
419
420 if ((gtp0->flags >> 5) != GTP_V0)
421 return 1;
422
423 /* If the sockets were created in kernel, it means that
424 * there is no daemon running in userspace which would
425 * handle echo request.
426 */
427 if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created)
428 return gtp0_send_echo_resp(gtp, skb);
429
430 if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created)
431 return gtp0_handle_echo_resp(gtp, skb);
432
433 if (gtp0->type != GTP_TPDU)
434 return 1;
435
436 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
437 if (!pctx) {
438 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
439 return 1;
440 }
441
442 return gtp_rx(pctx, skb, hdrlen, gtp->role);
443 }
444
445 /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */
gtp1u_build_echo_msg(struct gtp1_header_long * hdr,__u8 msg_type)446 static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type)
447 {
448 int len_pkt, len_hdr;
449
450 /* S flag must be set to 1 */
451 hdr->flags = 0x32; /* v1, GTP-non-prime. */
452 hdr->type = msg_type;
453 /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */
454 hdr->tid = 0;
455
456 /* seq, npdu and next should be counted to the length of the GTP packet
457 * that's why szie of gtp1_header should be subtracted,
458 * not size of gtp1_header_long.
459 */
460
461 len_hdr = sizeof(struct gtp1_header);
462
463 if (msg_type == GTP_ECHO_RSP) {
464 len_pkt = sizeof(struct gtp1u_packet);
465 hdr->length = htons(len_pkt - len_hdr);
466 } else {
467 /* GTP_ECHO_REQ does not carry GTP Information Element,
468 * the why gtp1_header_long is used here.
469 */
470 len_pkt = sizeof(struct gtp1_header_long);
471 hdr->length = htons(len_pkt - len_hdr);
472 }
473 }
474
gtp1u_send_echo_resp(struct gtp_dev * gtp,struct sk_buff * skb)475 static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
476 {
477 struct gtp1_header_long *gtp1u;
478 struct gtp1u_packet *gtp_pkt;
479 struct rtable *rt;
480 struct flowi4 fl4;
481 struct iphdr *iph;
482
483 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
484
485 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
486 * Error Indication and Supported Extension Headers Notification
487 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
488 */
489 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
490 return -1;
491
492 /* pull GTP and UDP headers */
493 skb_pull_data(skb,
494 sizeof(struct gtp1_header_long) + sizeof(struct udphdr));
495
496 gtp_pkt = skb_push(skb, sizeof(struct gtp1u_packet));
497 memset(gtp_pkt, 0, sizeof(struct gtp1u_packet));
498
499 gtp1u_build_echo_msg(>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
gtp1u_handle_echo_resp(struct gtp_dev * gtp,struct sk_buff * skb)534 static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb)
535 {
536 struct gtp1_header_long *gtp1u;
537 struct echo_info echo;
538 struct sk_buff *msg;
539 struct iphdr *iph;
540 int ret;
541
542 gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr));
543
544 /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response,
545 * Error Indication and Supported Extension Headers Notification
546 * messages, the S flag shall be set to 1 and TEID shall be set to 0.
547 */
548 if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid)
549 return -1;
550
551 iph = ip_hdr(skb);
552 echo.ms_addr_ip4.s_addr = iph->daddr;
553 echo.peer_addr_ip4.s_addr = iph->saddr;
554 echo.gtp_version = GTP_V1;
555
556 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
557 if (!msg)
558 return -ENOMEM;
559
560 ret = gtp_genl_fill_echo(msg, 0, 0, 0, GTP_CMD_ECHOREQ, echo);
561 if (ret < 0) {
562 nlmsg_free(msg);
563 return ret;
564 }
565
566 return genlmsg_multicast_netns(>p_genl_family, dev_net(gtp->dev),
567 msg, 0, GTP_GENL_MCGRP, GFP_ATOMIC);
568 }
569
gtp1u_udp_encap_recv(struct gtp_dev * gtp,struct sk_buff * skb)570 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
571 {
572 unsigned int hdrlen = sizeof(struct udphdr) +
573 sizeof(struct gtp1_header);
574 struct gtp1_header *gtp1;
575 struct pdp_ctx *pctx;
576
577 if (!pskb_may_pull(skb, hdrlen))
578 return -1;
579
580 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
581
582 if ((gtp1->flags >> 5) != GTP_V1)
583 return 1;
584
585 /* If the sockets were created in kernel, it means that
586 * there is no daemon running in userspace which would
587 * handle echo request.
588 */
589 if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created)
590 return gtp1u_send_echo_resp(gtp, skb);
591
592 if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created)
593 return gtp1u_handle_echo_resp(gtp, skb);
594
595 if (gtp1->type != GTP_TPDU)
596 return 1;
597
598 /* From 29.060: "This field shall be present if and only if any one or
599 * more of the S, PN and E flags are set.".
600 *
601 * If any of the bit is set, then the remaining ones also have to be
602 * set.
603 */
604 if (gtp1->flags & GTP1_F_MASK)
605 hdrlen += 4;
606
607 /* Make sure the header is larger enough, including extensions. */
608 if (!pskb_may_pull(skb, hdrlen))
609 return -1;
610
611 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
612
613 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
614 if (!pctx) {
615 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
616 return 1;
617 }
618
619 return gtp_rx(pctx, skb, hdrlen, gtp->role);
620 }
621
__gtp_encap_destroy(struct sock * sk)622 static void __gtp_encap_destroy(struct sock *sk)
623 {
624 struct gtp_dev *gtp;
625
626 lock_sock(sk);
627 gtp = sk->sk_user_data;
628 if (gtp) {
629 if (gtp->sk0 == sk)
630 gtp->sk0 = NULL;
631 else
632 gtp->sk1u = NULL;
633 WRITE_ONCE(udp_sk(sk)->encap_type, 0);
634 rcu_assign_sk_user_data(sk, NULL);
635 release_sock(sk);
636 sock_put(sk);
637 return;
638 }
639 release_sock(sk);
640 }
641
gtp_encap_destroy(struct sock * sk)642 static void gtp_encap_destroy(struct sock *sk)
643 {
644 rtnl_lock();
645 __gtp_encap_destroy(sk);
646 rtnl_unlock();
647 }
648
gtp_encap_disable_sock(struct sock * sk)649 static void gtp_encap_disable_sock(struct sock *sk)
650 {
651 if (!sk)
652 return;
653
654 __gtp_encap_destroy(sk);
655 }
656
gtp_encap_disable(struct gtp_dev * gtp)657 static void gtp_encap_disable(struct gtp_dev *gtp)
658 {
659 if (gtp->sk_created) {
660 udp_tunnel_sock_release(gtp->sk0->sk_socket);
661 udp_tunnel_sock_release(gtp->sk1u->sk_socket);
662 gtp->sk_created = false;
663 gtp->sk0 = NULL;
664 gtp->sk1u = NULL;
665 } else {
666 gtp_encap_disable_sock(gtp->sk0);
667 gtp_encap_disable_sock(gtp->sk1u);
668 }
669 }
670
671 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
672 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
673 */
gtp_encap_recv(struct sock * sk,struct sk_buff * skb)674 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
675 {
676 struct gtp_dev *gtp;
677 int ret = 0;
678
679 gtp = rcu_dereference_sk_user_data(sk);
680 if (!gtp)
681 return 1;
682
683 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
684
685 switch (READ_ONCE(udp_sk(sk)->encap_type)) {
686 case UDP_ENCAP_GTP0:
687 netdev_dbg(gtp->dev, "received GTP0 packet\n");
688 ret = gtp0_udp_encap_recv(gtp, skb);
689 break;
690 case UDP_ENCAP_GTP1U:
691 netdev_dbg(gtp->dev, "received GTP1U packet\n");
692 ret = gtp1u_udp_encap_recv(gtp, skb);
693 break;
694 default:
695 ret = -1; /* Shouldn't happen. */
696 }
697
698 switch (ret) {
699 case 1:
700 netdev_dbg(gtp->dev, "pass up to the process\n");
701 break;
702 case 0:
703 break;
704 case -1:
705 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
706 kfree_skb(skb);
707 ret = 0;
708 break;
709 }
710
711 return ret;
712 }
713
gtp_dev_init(struct net_device * dev)714 static 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
gtp_dev_uninit(struct net_device * dev)727 static 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
gtp0_push_header(struct sk_buff * skb,struct pdp_ctx * pctx)735 static 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
gtp1_push_header(struct sk_buff * skb,struct pdp_ctx * pctx)752 static 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
775 struct 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
gtp_push_header(struct sk_buff * skb,struct gtp_pktinfo * pktinfo)785 static 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
gtp_set_pktinfo_ipv4(struct gtp_pktinfo * pktinfo,struct sock * sk,struct iphdr * iph,struct pdp_ctx * pctx,struct rtable * rt,struct flowi4 * fl4,struct net_device * dev)799 static 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
gtp_build_skb_ip4(struct sk_buff * skb,struct net_device * dev,struct gtp_pktinfo * pktinfo)813 static 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;
888 err_rt:
889 ip_rt_put(rt);
890 err:
891 return -EBADMSG;
892 }
893
gtp_dev_xmit(struct sk_buff * skb,struct net_device * dev)894 static 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;
938 tx_err:
939 dev->stats.tx_errors++;
940 dev_kfree_skb(skb);
941 return NETDEV_TX_OK;
942 }
943
944 static 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
951 static const struct device_type gtp_type = {
952 .name = "gtp",
953 };
954
gtp_link_setup(struct net_device * dev)955 static 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
980 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
981 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
982
gtp_destructor(struct net_device * dev)983 static 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
gtp_create_sock(int type,struct gtp_dev * gtp)991 static 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
gtp_create_sockets(struct gtp_dev * gtp,struct nlattr * data[])1023 static 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
gtp_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1045 static 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
1103 out_encap:
1104 gtp_encap_disable(gtp);
1105 out_hashtable:
1106 kfree(gtp->addr_hash);
1107 kfree(gtp->tid_hash);
1108 return err;
1109 }
1110
gtp_dellink(struct net_device * dev,struct list_head * head)1111 static void gtp_dellink(struct net_device *dev, struct list_head *head)
1112 {
1113 struct gtp_dev *gtp = netdev_priv(dev);
1114 struct hlist_node *next;
1115 struct pdp_ctx *pctx;
1116 int i;
1117
1118 for (i = 0; i < gtp->hash_size; i++)
1119 hlist_for_each_entry_safe(pctx, next, >p->tid_hash[i], hlist_tid)
1120 pdp_context_delete(pctx);
1121
1122 list_del_rcu(>p->list);
1123 unregister_netdevice_queue(dev, head);
1124 }
1125
1126 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
1127 [IFLA_GTP_FD0] = { .type = NLA_U32 },
1128 [IFLA_GTP_FD1] = { .type = NLA_U32 },
1129 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
1130 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
1131 [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 },
1132 [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 },
1133 };
1134
gtp_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)1135 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
1136 struct netlink_ext_ack *extack)
1137 {
1138 if (!data)
1139 return -EINVAL;
1140
1141 return 0;
1142 }
1143
gtp_get_size(const struct net_device * dev)1144 static size_t gtp_get_size(const struct net_device *dev)
1145 {
1146 return nla_total_size(sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */
1147 nla_total_size(sizeof(__u32)) + /* IFLA_GTP_ROLE */
1148 nla_total_size(sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */
1149 }
1150
gtp_fill_info(struct sk_buff * skb,const struct net_device * dev)1151 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
1152 {
1153 struct gtp_dev *gtp = netdev_priv(dev);
1154
1155 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
1156 goto nla_put_failure;
1157 if (nla_put_u32(skb, IFLA_GTP_ROLE, gtp->role))
1158 goto nla_put_failure;
1159 if (nla_put_u8(skb, IFLA_GTP_RESTART_COUNT, gtp->restart_count))
1160 goto nla_put_failure;
1161
1162 return 0;
1163
1164 nla_put_failure:
1165 return -EMSGSIZE;
1166 }
1167
1168 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
1169 .kind = "gtp",
1170 .maxtype = IFLA_GTP_MAX,
1171 .policy = gtp_policy,
1172 .priv_size = sizeof(struct gtp_dev),
1173 .setup = gtp_link_setup,
1174 .validate = gtp_validate,
1175 .newlink = gtp_newlink,
1176 .dellink = gtp_dellink,
1177 .get_size = gtp_get_size,
1178 .fill_info = gtp_fill_info,
1179 };
1180
gtp_hashtable_new(struct gtp_dev * gtp,int hsize)1181 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
1182 {
1183 int i;
1184
1185 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1186 GFP_KERNEL | __GFP_NOWARN);
1187 if (gtp->addr_hash == NULL)
1188 return -ENOMEM;
1189
1190 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
1191 GFP_KERNEL | __GFP_NOWARN);
1192 if (gtp->tid_hash == NULL)
1193 goto err1;
1194
1195 gtp->hash_size = hsize;
1196
1197 for (i = 0; i < hsize; i++) {
1198 INIT_HLIST_HEAD(>p->addr_hash[i]);
1199 INIT_HLIST_HEAD(>p->tid_hash[i]);
1200 }
1201 return 0;
1202 err1:
1203 kfree(gtp->addr_hash);
1204 return -ENOMEM;
1205 }
1206
gtp_encap_enable_socket(int fd,int type,struct gtp_dev * gtp)1207 static struct sock *gtp_encap_enable_socket(int fd, int type,
1208 struct gtp_dev *gtp)
1209 {
1210 struct udp_tunnel_sock_cfg tuncfg = {NULL};
1211 struct socket *sock;
1212 struct sock *sk;
1213 int err;
1214
1215 pr_debug("enable gtp on %d, %d\n", fd, type);
1216
1217 sock = sockfd_lookup(fd, &err);
1218 if (!sock) {
1219 pr_debug("gtp socket fd=%d not found\n", fd);
1220 return NULL;
1221 }
1222
1223 sk = sock->sk;
1224 if (sk->sk_protocol != IPPROTO_UDP ||
1225 sk->sk_type != SOCK_DGRAM ||
1226 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
1227 pr_debug("socket fd=%d not UDP\n", fd);
1228 sk = ERR_PTR(-EINVAL);
1229 goto out_sock;
1230 }
1231
1232 lock_sock(sk);
1233 if (sk->sk_user_data) {
1234 sk = ERR_PTR(-EBUSY);
1235 goto out_rel_sock;
1236 }
1237
1238 sock_hold(sk);
1239
1240 tuncfg.sk_user_data = gtp;
1241 tuncfg.encap_type = type;
1242 tuncfg.encap_rcv = gtp_encap_recv;
1243 tuncfg.encap_destroy = gtp_encap_destroy;
1244
1245 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
1246
1247 out_rel_sock:
1248 release_sock(sock->sk);
1249 out_sock:
1250 sockfd_put(sock);
1251 return sk;
1252 }
1253
gtp_encap_enable(struct gtp_dev * gtp,struct nlattr * data[])1254 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
1255 {
1256 struct sock *sk1u = NULL;
1257 struct sock *sk0 = NULL;
1258
1259 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
1260 return -EINVAL;
1261
1262 if (data[IFLA_GTP_FD0]) {
1263 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
1264
1265 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
1266 if (IS_ERR(sk0))
1267 return PTR_ERR(sk0);
1268 }
1269
1270 if (data[IFLA_GTP_FD1]) {
1271 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
1272
1273 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
1274 if (IS_ERR(sk1u)) {
1275 gtp_encap_disable_sock(sk0);
1276 return PTR_ERR(sk1u);
1277 }
1278 }
1279
1280 gtp->sk0 = sk0;
1281 gtp->sk1u = sk1u;
1282
1283 return 0;
1284 }
1285
gtp_find_dev(struct net * src_net,struct nlattr * nla[])1286 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
1287 {
1288 struct gtp_dev *gtp = NULL;
1289 struct net_device *dev;
1290 struct net *net;
1291
1292 /* Examine the link attributes and figure out which network namespace
1293 * we are talking about.
1294 */
1295 if (nla[GTPA_NET_NS_FD])
1296 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
1297 else
1298 net = get_net(src_net);
1299
1300 if (IS_ERR(net))
1301 return NULL;
1302
1303 /* Check if there's an existing gtpX device to configure */
1304 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
1305 if (dev && dev->netdev_ops == >p_netdev_ops)
1306 gtp = netdev_priv(dev);
1307
1308 put_net(net);
1309 return gtp;
1310 }
1311
ipv4_pdp_fill(struct pdp_ctx * pctx,struct genl_info * info)1312 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
1313 {
1314 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1315 pctx->af = AF_INET;
1316 pctx->peer_addr_ip4.s_addr =
1317 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1318 pctx->ms_addr_ip4.s_addr =
1319 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1320
1321 switch (pctx->gtp_version) {
1322 case GTP_V0:
1323 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
1324 * label needs to be the same for uplink and downlink packets,
1325 * so let's annotate this.
1326 */
1327 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
1328 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
1329 break;
1330 case GTP_V1:
1331 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
1332 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
1333 break;
1334 default:
1335 break;
1336 }
1337 }
1338
gtp_pdp_add(struct gtp_dev * gtp,struct sock * sk,struct genl_info * info)1339 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
1340 struct genl_info *info)
1341 {
1342 struct pdp_ctx *pctx, *pctx_tid = NULL;
1343 struct net_device *dev = gtp->dev;
1344 u32 hash_ms, hash_tid = 0;
1345 unsigned int version;
1346 bool found = false;
1347 __be32 ms_addr;
1348
1349 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1350 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
1351 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1352
1353 pctx = ipv4_pdp_find(gtp, ms_addr);
1354 if (pctx)
1355 found = true;
1356 if (version == GTP_V0)
1357 pctx_tid = gtp0_pdp_find(gtp,
1358 nla_get_u64(info->attrs[GTPA_TID]));
1359 else if (version == GTP_V1)
1360 pctx_tid = gtp1_pdp_find(gtp,
1361 nla_get_u32(info->attrs[GTPA_I_TEI]));
1362 if (pctx_tid)
1363 found = true;
1364
1365 if (found) {
1366 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
1367 return ERR_PTR(-EEXIST);
1368 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
1369 return ERR_PTR(-EOPNOTSUPP);
1370
1371 if (pctx && pctx_tid)
1372 return ERR_PTR(-EEXIST);
1373 if (!pctx)
1374 pctx = pctx_tid;
1375
1376 ipv4_pdp_fill(pctx, info);
1377
1378 if (pctx->gtp_version == GTP_V0)
1379 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
1380 pctx->u.v0.tid, pctx);
1381 else if (pctx->gtp_version == GTP_V1)
1382 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
1383 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1384
1385 return pctx;
1386
1387 }
1388
1389 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
1390 if (pctx == NULL)
1391 return ERR_PTR(-ENOMEM);
1392
1393 sock_hold(sk);
1394 pctx->sk = sk;
1395 pctx->dev = gtp->dev;
1396 ipv4_pdp_fill(pctx, info);
1397 atomic_set(&pctx->tx_seq, 0);
1398
1399 switch (pctx->gtp_version) {
1400 case GTP_V0:
1401 /* TS 09.60: "The flow label identifies unambiguously a GTP
1402 * flow.". We use the tid for this instead, I cannot find a
1403 * situation in which this doesn't unambiguosly identify the
1404 * PDP context.
1405 */
1406 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
1407 break;
1408 case GTP_V1:
1409 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1410 break;
1411 }
1412
1413 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
1414 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1415
1416 switch (pctx->gtp_version) {
1417 case GTP_V0:
1418 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1419 pctx->u.v0.tid, &pctx->peer_addr_ip4,
1420 &pctx->ms_addr_ip4, pctx);
1421 break;
1422 case GTP_V1:
1423 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1424 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1425 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1426 break;
1427 }
1428
1429 return pctx;
1430 }
1431
pdp_context_free(struct rcu_head * head)1432 static void pdp_context_free(struct rcu_head *head)
1433 {
1434 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1435
1436 sock_put(pctx->sk);
1437 kfree(pctx);
1438 }
1439
pdp_context_delete(struct pdp_ctx * pctx)1440 static void pdp_context_delete(struct pdp_ctx *pctx)
1441 {
1442 hlist_del_rcu(&pctx->hlist_tid);
1443 hlist_del_rcu(&pctx->hlist_addr);
1444 call_rcu(&pctx->rcu_head, pdp_context_free);
1445 }
1446
1447 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1448
gtp_genl_new_pdp(struct sk_buff * skb,struct genl_info * info)1449 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1450 {
1451 unsigned int version;
1452 struct pdp_ctx *pctx;
1453 struct gtp_dev *gtp;
1454 struct sock *sk;
1455 int err;
1456
1457 if (!info->attrs[GTPA_VERSION] ||
1458 !info->attrs[GTPA_LINK] ||
1459 !info->attrs[GTPA_PEER_ADDRESS] ||
1460 !info->attrs[GTPA_MS_ADDRESS])
1461 return -EINVAL;
1462
1463 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1464
1465 switch (version) {
1466 case GTP_V0:
1467 if (!info->attrs[GTPA_TID] ||
1468 !info->attrs[GTPA_FLOW])
1469 return -EINVAL;
1470 break;
1471 case GTP_V1:
1472 if (!info->attrs[GTPA_I_TEI] ||
1473 !info->attrs[GTPA_O_TEI])
1474 return -EINVAL;
1475 break;
1476
1477 default:
1478 return -EINVAL;
1479 }
1480
1481 rtnl_lock();
1482
1483 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1484 if (!gtp) {
1485 err = -ENODEV;
1486 goto out_unlock;
1487 }
1488
1489 if (version == GTP_V0)
1490 sk = gtp->sk0;
1491 else if (version == GTP_V1)
1492 sk = gtp->sk1u;
1493 else
1494 sk = NULL;
1495
1496 if (!sk) {
1497 err = -ENODEV;
1498 goto out_unlock;
1499 }
1500
1501 pctx = gtp_pdp_add(gtp, sk, info);
1502 if (IS_ERR(pctx)) {
1503 err = PTR_ERR(pctx);
1504 } else {
1505 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1506 err = 0;
1507 }
1508
1509 out_unlock:
1510 rtnl_unlock();
1511 return err;
1512 }
1513
gtp_find_pdp_by_link(struct net * net,struct nlattr * nla[])1514 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1515 struct nlattr *nla[])
1516 {
1517 struct gtp_dev *gtp;
1518
1519 gtp = gtp_find_dev(net, nla);
1520 if (!gtp)
1521 return ERR_PTR(-ENODEV);
1522
1523 if (nla[GTPA_MS_ADDRESS]) {
1524 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1525
1526 return ipv4_pdp_find(gtp, ip);
1527 } else if (nla[GTPA_VERSION]) {
1528 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1529
1530 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1531 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1532 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1533 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1534 }
1535
1536 return ERR_PTR(-EINVAL);
1537 }
1538
gtp_find_pdp(struct net * net,struct nlattr * nla[])1539 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1540 {
1541 struct pdp_ctx *pctx;
1542
1543 if (nla[GTPA_LINK])
1544 pctx = gtp_find_pdp_by_link(net, nla);
1545 else
1546 pctx = ERR_PTR(-EINVAL);
1547
1548 if (!pctx)
1549 pctx = ERR_PTR(-ENOENT);
1550
1551 return pctx;
1552 }
1553
gtp_genl_del_pdp(struct sk_buff * skb,struct genl_info * info)1554 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1555 {
1556 struct pdp_ctx *pctx;
1557 int err = 0;
1558
1559 if (!info->attrs[GTPA_VERSION])
1560 return -EINVAL;
1561
1562 rcu_read_lock();
1563
1564 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1565 if (IS_ERR(pctx)) {
1566 err = PTR_ERR(pctx);
1567 goto out_unlock;
1568 }
1569
1570 if (pctx->gtp_version == GTP_V0)
1571 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1572 pctx->u.v0.tid, pctx);
1573 else if (pctx->gtp_version == GTP_V1)
1574 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1575 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1576
1577 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1578 pdp_context_delete(pctx);
1579
1580 out_unlock:
1581 rcu_read_unlock();
1582 return err;
1583 }
1584
gtp_genl_fill_info(struct sk_buff * skb,u32 snd_portid,u32 snd_seq,int flags,u32 type,struct pdp_ctx * pctx)1585 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1586 int flags, u32 type, struct pdp_ctx *pctx)
1587 {
1588 void *genlh;
1589
1590 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
1591 type);
1592 if (genlh == NULL)
1593 goto nlmsg_failure;
1594
1595 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1596 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1597 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1598 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1599 goto nla_put_failure;
1600
1601 switch (pctx->gtp_version) {
1602 case GTP_V0:
1603 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1604 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1605 goto nla_put_failure;
1606 break;
1607 case GTP_V1:
1608 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1609 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1610 goto nla_put_failure;
1611 break;
1612 }
1613 genlmsg_end(skb, genlh);
1614 return 0;
1615
1616 nlmsg_failure:
1617 nla_put_failure:
1618 genlmsg_cancel(skb, genlh);
1619 return -EMSGSIZE;
1620 }
1621
gtp_tunnel_notify(struct pdp_ctx * pctx,u8 cmd,gfp_t allocation)1622 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1623 {
1624 struct sk_buff *msg;
1625 int ret;
1626
1627 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1628 if (!msg)
1629 return -ENOMEM;
1630
1631 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1632 if (ret < 0) {
1633 nlmsg_free(msg);
1634 return ret;
1635 }
1636
1637 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg,
1638 0, GTP_GENL_MCGRP, GFP_ATOMIC);
1639 return ret;
1640 }
1641
gtp_genl_get_pdp(struct sk_buff * skb,struct genl_info * info)1642 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1643 {
1644 struct pdp_ctx *pctx = NULL;
1645 struct sk_buff *skb2;
1646 int err;
1647
1648 if (!info->attrs[GTPA_VERSION])
1649 return -EINVAL;
1650
1651 rcu_read_lock();
1652
1653 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1654 if (IS_ERR(pctx)) {
1655 err = PTR_ERR(pctx);
1656 goto err_unlock;
1657 }
1658
1659 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1660 if (skb2 == NULL) {
1661 err = -ENOMEM;
1662 goto err_unlock;
1663 }
1664
1665 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1666 0, info->nlhdr->nlmsg_type, pctx);
1667 if (err < 0)
1668 goto err_unlock_free;
1669
1670 rcu_read_unlock();
1671 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1672
1673 err_unlock_free:
1674 kfree_skb(skb2);
1675 err_unlock:
1676 rcu_read_unlock();
1677 return err;
1678 }
1679
gtp_genl_dump_pdp(struct sk_buff * skb,struct netlink_callback * cb)1680 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1681 struct netlink_callback *cb)
1682 {
1683 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1684 int i, j, bucket = cb->args[0], skip = cb->args[1];
1685 struct net *net = sock_net(skb->sk);
1686 struct pdp_ctx *pctx;
1687 struct gtp_net *gn;
1688
1689 gn = net_generic(net, gtp_net_id);
1690
1691 if (cb->args[4])
1692 return 0;
1693
1694 rcu_read_lock();
1695 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1696 if (last_gtp && last_gtp != gtp)
1697 continue;
1698 else
1699 last_gtp = NULL;
1700
1701 for (i = bucket; i < gtp->hash_size; i++) {
1702 j = 0;
1703 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
1704 hlist_tid) {
1705 if (j >= skip &&
1706 gtp_genl_fill_info(skb,
1707 NETLINK_CB(cb->skb).portid,
1708 cb->nlh->nlmsg_seq,
1709 NLM_F_MULTI,
1710 cb->nlh->nlmsg_type, pctx)) {
1711 cb->args[0] = i;
1712 cb->args[1] = j;
1713 cb->args[2] = (unsigned long)gtp;
1714 goto out;
1715 }
1716 j++;
1717 }
1718 skip = 0;
1719 }
1720 bucket = 0;
1721 }
1722 cb->args[4] = 1;
1723 out:
1724 rcu_read_unlock();
1725 return skb->len;
1726 }
1727
gtp_genl_send_echo_req(struct sk_buff * skb,struct genl_info * info)1728 static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info)
1729 {
1730 struct sk_buff *skb_to_send;
1731 __be32 src_ip, dst_ip;
1732 unsigned int version;
1733 struct gtp_dev *gtp;
1734 struct flowi4 fl4;
1735 struct rtable *rt;
1736 struct sock *sk;
1737 __be16 port;
1738 int len;
1739
1740 if (!info->attrs[GTPA_VERSION] ||
1741 !info->attrs[GTPA_LINK] ||
1742 !info->attrs[GTPA_PEER_ADDRESS] ||
1743 !info->attrs[GTPA_MS_ADDRESS])
1744 return -EINVAL;
1745
1746 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1747 dst_ip = nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
1748 src_ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1749
1750 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1751 if (!gtp)
1752 return -ENODEV;
1753
1754 if (!gtp->sk_created)
1755 return -EOPNOTSUPP;
1756 if (!(gtp->dev->flags & IFF_UP))
1757 return -ENETDOWN;
1758
1759 if (version == GTP_V0) {
1760 struct gtp0_header *gtp0_h;
1761
1762 len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) +
1763 sizeof(struct iphdr) + sizeof(struct udphdr);
1764
1765 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1766 if (!skb_to_send)
1767 return -ENOMEM;
1768
1769 sk = gtp->sk0;
1770 port = htons(GTP0_PORT);
1771
1772 gtp0_h = skb_push(skb_to_send, sizeof(struct gtp0_header));
1773 memset(gtp0_h, 0, sizeof(struct gtp0_header));
1774 gtp0_build_echo_msg(gtp0_h, GTP_ECHO_REQ);
1775 } else if (version == GTP_V1) {
1776 struct gtp1_header_long *gtp1u_h;
1777
1778 len = LL_RESERVED_SPACE(gtp->dev) +
1779 sizeof(struct gtp1_header_long) +
1780 sizeof(struct iphdr) + sizeof(struct udphdr);
1781
1782 skb_to_send = netdev_alloc_skb_ip_align(gtp->dev, len);
1783 if (!skb_to_send)
1784 return -ENOMEM;
1785
1786 sk = gtp->sk1u;
1787 port = htons(GTP1U_PORT);
1788
1789 gtp1u_h = skb_push(skb_to_send,
1790 sizeof(struct gtp1_header_long));
1791 memset(gtp1u_h, 0, sizeof(struct gtp1_header_long));
1792 gtp1u_build_echo_msg(gtp1u_h, GTP_ECHO_REQ);
1793 } else {
1794 return -ENODEV;
1795 }
1796
1797 rt = ip4_route_output_gtp(&fl4, sk, dst_ip, src_ip);
1798 if (IS_ERR(rt)) {
1799 netdev_dbg(gtp->dev, "no route for echo request to %pI4\n",
1800 &dst_ip);
1801 kfree_skb(skb_to_send);
1802 return -ENODEV;
1803 }
1804
1805 udp_tunnel_xmit_skb(rt, sk, skb_to_send,
1806 fl4.saddr, fl4.daddr,
1807 fl4.flowi4_tos,
1808 ip4_dst_hoplimit(&rt->dst),
1809 0,
1810 port, port,
1811 !net_eq(sock_net(sk),
1812 dev_net(gtp->dev)),
1813 false);
1814 return 0;
1815 }
1816
1817 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1818 [GTPA_LINK] = { .type = NLA_U32, },
1819 [GTPA_VERSION] = { .type = NLA_U32, },
1820 [GTPA_TID] = { .type = NLA_U64, },
1821 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1822 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1823 [GTPA_FLOW] = { .type = NLA_U16, },
1824 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1825 [GTPA_I_TEI] = { .type = NLA_U32, },
1826 [GTPA_O_TEI] = { .type = NLA_U32, },
1827 };
1828
1829 static const struct genl_small_ops gtp_genl_ops[] = {
1830 {
1831 .cmd = GTP_CMD_NEWPDP,
1832 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1833 .doit = gtp_genl_new_pdp,
1834 .flags = GENL_ADMIN_PERM,
1835 },
1836 {
1837 .cmd = GTP_CMD_DELPDP,
1838 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1839 .doit = gtp_genl_del_pdp,
1840 .flags = GENL_ADMIN_PERM,
1841 },
1842 {
1843 .cmd = GTP_CMD_GETPDP,
1844 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1845 .doit = gtp_genl_get_pdp,
1846 .dumpit = gtp_genl_dump_pdp,
1847 .flags = GENL_ADMIN_PERM,
1848 },
1849 {
1850 .cmd = GTP_CMD_ECHOREQ,
1851 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1852 .doit = gtp_genl_send_echo_req,
1853 .flags = GENL_ADMIN_PERM,
1854 },
1855 };
1856
1857 static struct genl_family gtp_genl_family __ro_after_init = {
1858 .name = "gtp",
1859 .version = 0,
1860 .hdrsize = 0,
1861 .maxattr = GTPA_MAX,
1862 .policy = gtp_genl_policy,
1863 .netnsok = true,
1864 .module = THIS_MODULE,
1865 .small_ops = gtp_genl_ops,
1866 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
1867 .resv_start_op = GTP_CMD_ECHOREQ + 1,
1868 .mcgrps = gtp_genl_mcgrps,
1869 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
1870 };
1871
gtp_net_init(struct net * net)1872 static int __net_init gtp_net_init(struct net *net)
1873 {
1874 struct gtp_net *gn = net_generic(net, gtp_net_id);
1875
1876 INIT_LIST_HEAD(&gn->gtp_dev_list);
1877 return 0;
1878 }
1879
gtp_net_exit(struct net * net)1880 static void __net_exit gtp_net_exit(struct net *net)
1881 {
1882 struct gtp_net *gn = net_generic(net, gtp_net_id);
1883 struct gtp_dev *gtp;
1884 LIST_HEAD(list);
1885
1886 rtnl_lock();
1887 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1888 gtp_dellink(gtp->dev, &list);
1889
1890 unregister_netdevice_many(&list);
1891 rtnl_unlock();
1892 }
1893
1894 static struct pernet_operations gtp_net_ops = {
1895 .init = gtp_net_init,
1896 .exit = gtp_net_exit,
1897 .id = >p_net_id,
1898 .size = sizeof(struct gtp_net),
1899 };
1900
gtp_init(void)1901 static int __init gtp_init(void)
1902 {
1903 int err;
1904
1905 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1906
1907 err = register_pernet_subsys(>p_net_ops);
1908 if (err < 0)
1909 goto error_out;
1910
1911 err = rtnl_link_register(>p_link_ops);
1912 if (err < 0)
1913 goto unreg_pernet_subsys;
1914
1915 err = genl_register_family(>p_genl_family);
1916 if (err < 0)
1917 goto unreg_rtnl_link;
1918
1919 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1920 sizeof(struct pdp_ctx));
1921 return 0;
1922
1923 unreg_rtnl_link:
1924 rtnl_link_unregister(>p_link_ops);
1925 unreg_pernet_subsys:
1926 unregister_pernet_subsys(>p_net_ops);
1927 error_out:
1928 pr_err("error loading GTP module loaded\n");
1929 return err;
1930 }
1931 late_initcall(gtp_init);
1932
gtp_fini(void)1933 static void __exit gtp_fini(void)
1934 {
1935 genl_unregister_family(>p_genl_family);
1936 rtnl_link_unregister(>p_link_ops);
1937 unregister_pernet_subsys(>p_net_ops);
1938
1939 pr_info("GTP module unloaded\n");
1940 }
1941 module_exit(gtp_fini);
1942
1943 MODULE_LICENSE("GPL");
1944 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1945 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1946 MODULE_ALIAS_RTNL_LINK("gtp");
1947 MODULE_ALIAS_GENL_FAMILY("gtp");
1948