1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* GTP according to GSM TS 09.60 / 3GPP TS 29.060
3 *
4 * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH
5 * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org>
6 *
7 * Author: Harald Welte <hwelte@sysmocom.de>
8 * Pablo Neira Ayuso <pablo@netfilter.org>
9 * Andreas Schultz <aschultz@travelping.com>
10 */
11
12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
13
14 #include <linux/module.h>
15 #include <linux/skbuff.h>
16 #include <linux/udp.h>
17 #include <linux/rculist.h>
18 #include <linux/jhash.h>
19 #include <linux/if_tunnel.h>
20 #include <linux/net.h>
21 #include <linux/file.h>
22 #include <linux/gtp.h>
23
24 #include <net/net_namespace.h>
25 #include <net/protocol.h>
26 #include <net/ip.h>
27 #include <net/udp.h>
28 #include <net/udp_tunnel.h>
29 #include <net/icmp.h>
30 #include <net/xfrm.h>
31 #include <net/genetlink.h>
32 #include <net/netns/generic.h>
33 #include <net/gtp.h>
34
35 /* An active session for the subscriber. */
36 struct pdp_ctx {
37 struct hlist_node hlist_tid;
38 struct hlist_node hlist_addr;
39
40 union {
41 struct {
42 u64 tid;
43 u16 flow;
44 } v0;
45 struct {
46 u32 i_tei;
47 u32 o_tei;
48 } v1;
49 } u;
50 u8 gtp_version;
51 u16 af;
52
53 struct in_addr ms_addr_ip4;
54 struct in_addr peer_addr_ip4;
55
56 struct sock *sk;
57 struct net_device *dev;
58
59 atomic_t tx_seq;
60 struct rcu_head rcu_head;
61 };
62
63 /* One instance of the GTP device. */
64 struct gtp_dev {
65 struct list_head list;
66
67 struct sock *sk0;
68 struct sock *sk1u;
69
70 struct net_device *dev;
71
72 unsigned int role;
73 unsigned int hash_size;
74 struct hlist_head *tid_hash;
75 struct hlist_head *addr_hash;
76 };
77
78 static unsigned int gtp_net_id __read_mostly;
79
80 struct gtp_net {
81 struct list_head gtp_dev_list;
82 };
83
84 static u32 gtp_h_initval;
85
86 static void pdp_context_delete(struct pdp_ctx *pctx);
87
gtp0_hashfn(u64 tid)88 static inline u32 gtp0_hashfn(u64 tid)
89 {
90 u32 *tid32 = (u32 *) &tid;
91 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
92 }
93
gtp1u_hashfn(u32 tid)94 static inline u32 gtp1u_hashfn(u32 tid)
95 {
96 return jhash_1word(tid, gtp_h_initval);
97 }
98
ipv4_hashfn(__be32 ip)99 static inline u32 ipv4_hashfn(__be32 ip)
100 {
101 return jhash_1word((__force u32)ip, gtp_h_initval);
102 }
103
104 /* Resolve a PDP context structure based on the 64bit TID. */
gtp0_pdp_find(struct gtp_dev * gtp,u64 tid)105 static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
106 {
107 struct hlist_head *head;
108 struct pdp_ctx *pdp;
109
110 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
111
112 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
113 if (pdp->gtp_version == GTP_V0 &&
114 pdp->u.v0.tid == tid)
115 return pdp;
116 }
117 return NULL;
118 }
119
120 /* Resolve a PDP context structure based on the 32bit TEI. */
gtp1_pdp_find(struct gtp_dev * gtp,u32 tid)121 static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
122 {
123 struct hlist_head *head;
124 struct pdp_ctx *pdp;
125
126 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
127
128 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
129 if (pdp->gtp_version == GTP_V1 &&
130 pdp->u.v1.i_tei == tid)
131 return pdp;
132 }
133 return NULL;
134 }
135
136 /* Resolve a PDP context based on IPv4 address of MS. */
ipv4_pdp_find(struct gtp_dev * gtp,__be32 ms_addr)137 static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
138 {
139 struct hlist_head *head;
140 struct pdp_ctx *pdp;
141
142 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
143
144 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
145 if (pdp->af == AF_INET &&
146 pdp->ms_addr_ip4.s_addr == ms_addr)
147 return pdp;
148 }
149
150 return NULL;
151 }
152
gtp_check_ms_ipv4(struct sk_buff * skb,struct pdp_ctx * pctx,unsigned int hdrlen,unsigned int role)153 static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
154 unsigned int hdrlen, unsigned int role)
155 {
156 struct iphdr *iph;
157
158 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
159 return false;
160
161 iph = (struct iphdr *)(skb->data + hdrlen);
162
163 if (role == GTP_ROLE_SGSN)
164 return iph->daddr == pctx->ms_addr_ip4.s_addr;
165 else
166 return iph->saddr == pctx->ms_addr_ip4.s_addr;
167 }
168
169 /* Check if the inner IP address in this packet is assigned to any
170 * existing mobile subscriber.
171 */
gtp_check_ms(struct sk_buff * skb,struct pdp_ctx * pctx,unsigned int hdrlen,unsigned int role)172 static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
173 unsigned int hdrlen, unsigned int role)
174 {
175 switch (ntohs(skb->protocol)) {
176 case ETH_P_IP:
177 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
178 }
179 return false;
180 }
181
gtp_rx(struct pdp_ctx * pctx,struct sk_buff * skb,unsigned int hdrlen,unsigned int role)182 static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
183 unsigned int hdrlen, unsigned int role)
184 {
185 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
186 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
187 return 1;
188 }
189
190 /* Get rid of the GTP + UDP headers. */
191 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
192 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
193 return -1;
194
195 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
196
197 /* Now that the UDP and the GTP header have been removed, set up the
198 * new network header. This is required by the upper layer to
199 * calculate the transport header.
200 */
201 skb_reset_network_header(skb);
202
203 skb->dev = pctx->dev;
204
205 dev_sw_netstats_rx_add(pctx->dev, skb->len);
206
207 netif_rx(skb);
208 return 0;
209 }
210
211 /* 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)212 static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
213 {
214 unsigned int hdrlen = sizeof(struct udphdr) +
215 sizeof(struct gtp0_header);
216 struct gtp0_header *gtp0;
217 struct pdp_ctx *pctx;
218
219 if (!pskb_may_pull(skb, hdrlen))
220 return -1;
221
222 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
223
224 if ((gtp0->flags >> 5) != GTP_V0)
225 return 1;
226
227 if (gtp0->type != GTP_TPDU)
228 return 1;
229
230 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
231 if (!pctx) {
232 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
233 return 1;
234 }
235
236 return gtp_rx(pctx, skb, hdrlen, gtp->role);
237 }
238
gtp1u_udp_encap_recv(struct gtp_dev * gtp,struct sk_buff * skb)239 static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
240 {
241 unsigned int hdrlen = sizeof(struct udphdr) +
242 sizeof(struct gtp1_header);
243 struct gtp1_header *gtp1;
244 struct pdp_ctx *pctx;
245
246 if (!pskb_may_pull(skb, hdrlen))
247 return -1;
248
249 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
250
251 if ((gtp1->flags >> 5) != GTP_V1)
252 return 1;
253
254 if (gtp1->type != GTP_TPDU)
255 return 1;
256
257 /* From 29.060: "This field shall be present if and only if any one or
258 * more of the S, PN and E flags are set.".
259 *
260 * If any of the bit is set, then the remaining ones also have to be
261 * set.
262 */
263 if (gtp1->flags & GTP1_F_MASK)
264 hdrlen += 4;
265
266 /* Make sure the header is larger enough, including extensions. */
267 if (!pskb_may_pull(skb, hdrlen))
268 return -1;
269
270 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
271
272 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
273 if (!pctx) {
274 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
275 return 1;
276 }
277
278 return gtp_rx(pctx, skb, hdrlen, gtp->role);
279 }
280
__gtp_encap_destroy(struct sock * sk)281 static void __gtp_encap_destroy(struct sock *sk)
282 {
283 struct gtp_dev *gtp;
284
285 lock_sock(sk);
286 gtp = sk->sk_user_data;
287 if (gtp) {
288 if (gtp->sk0 == sk)
289 gtp->sk0 = NULL;
290 else
291 gtp->sk1u = NULL;
292 udp_sk(sk)->encap_type = 0;
293 rcu_assign_sk_user_data(sk, NULL);
294 sock_put(sk);
295 }
296 release_sock(sk);
297 }
298
gtp_encap_destroy(struct sock * sk)299 static void gtp_encap_destroy(struct sock *sk)
300 {
301 rtnl_lock();
302 __gtp_encap_destroy(sk);
303 rtnl_unlock();
304 }
305
gtp_encap_disable_sock(struct sock * sk)306 static void gtp_encap_disable_sock(struct sock *sk)
307 {
308 if (!sk)
309 return;
310
311 __gtp_encap_destroy(sk);
312 }
313
gtp_encap_disable(struct gtp_dev * gtp)314 static void gtp_encap_disable(struct gtp_dev *gtp)
315 {
316 gtp_encap_disable_sock(gtp->sk0);
317 gtp_encap_disable_sock(gtp->sk1u);
318 }
319
320 /* UDP encapsulation receive handler. See net/ipv4/udp.c.
321 * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket.
322 */
gtp_encap_recv(struct sock * sk,struct sk_buff * skb)323 static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
324 {
325 struct gtp_dev *gtp;
326 int ret = 0;
327
328 gtp = rcu_dereference_sk_user_data(sk);
329 if (!gtp)
330 return 1;
331
332 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
333
334 switch (udp_sk(sk)->encap_type) {
335 case UDP_ENCAP_GTP0:
336 netdev_dbg(gtp->dev, "received GTP0 packet\n");
337 ret = gtp0_udp_encap_recv(gtp, skb);
338 break;
339 case UDP_ENCAP_GTP1U:
340 netdev_dbg(gtp->dev, "received GTP1U packet\n");
341 ret = gtp1u_udp_encap_recv(gtp, skb);
342 break;
343 default:
344 ret = -1; /* Shouldn't happen. */
345 }
346
347 switch (ret) {
348 case 1:
349 netdev_dbg(gtp->dev, "pass up to the process\n");
350 break;
351 case 0:
352 break;
353 case -1:
354 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
355 kfree_skb(skb);
356 ret = 0;
357 break;
358 }
359
360 return ret;
361 }
362
gtp_dev_init(struct net_device * dev)363 static int gtp_dev_init(struct net_device *dev)
364 {
365 struct gtp_dev *gtp = netdev_priv(dev);
366
367 gtp->dev = dev;
368
369 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
370 if (!dev->tstats)
371 return -ENOMEM;
372
373 return 0;
374 }
375
gtp_dev_uninit(struct net_device * dev)376 static void gtp_dev_uninit(struct net_device *dev)
377 {
378 struct gtp_dev *gtp = netdev_priv(dev);
379
380 gtp_encap_disable(gtp);
381 free_percpu(dev->tstats);
382 }
383
ip4_route_output_gtp(struct flowi4 * fl4,const struct sock * sk,__be32 daddr)384 static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
385 const struct sock *sk,
386 __be32 daddr)
387 {
388 memset(fl4, 0, sizeof(*fl4));
389 fl4->flowi4_oif = sk->sk_bound_dev_if;
390 fl4->daddr = daddr;
391 fl4->saddr = inet_sk(sk)->inet_saddr;
392 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
393 fl4->flowi4_proto = sk->sk_protocol;
394
395 return ip_route_output_key(sock_net(sk), fl4);
396 }
397
gtp0_push_header(struct sk_buff * skb,struct pdp_ctx * pctx)398 static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
399 {
400 int payload_len = skb->len;
401 struct gtp0_header *gtp0;
402
403 gtp0 = skb_push(skb, sizeof(*gtp0));
404
405 gtp0->flags = 0x1e; /* v0, GTP-non-prime. */
406 gtp0->type = GTP_TPDU;
407 gtp0->length = htons(payload_len);
408 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
409 gtp0->flow = htons(pctx->u.v0.flow);
410 gtp0->number = 0xff;
411 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
412 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
413 }
414
gtp1_push_header(struct sk_buff * skb,struct pdp_ctx * pctx)415 static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
416 {
417 int payload_len = skb->len;
418 struct gtp1_header *gtp1;
419
420 gtp1 = skb_push(skb, sizeof(*gtp1));
421
422 /* Bits 8 7 6 5 4 3 2 1
423 * +--+--+--+--+--+--+--+--+
424 * |version |PT| 0| E| S|PN|
425 * +--+--+--+--+--+--+--+--+
426 * 0 0 1 1 1 0 0 0
427 */
428 gtp1->flags = 0x30; /* v1, GTP-non-prime. */
429 gtp1->type = GTP_TPDU;
430 gtp1->length = htons(payload_len);
431 gtp1->tid = htonl(pctx->u.v1.o_tei);
432
433 /* TODO: Suppport for extension header, sequence number and N-PDU.
434 * Update the length field if any of them is available.
435 */
436 }
437
438 struct gtp_pktinfo {
439 struct sock *sk;
440 struct iphdr *iph;
441 struct flowi4 fl4;
442 struct rtable *rt;
443 struct pdp_ctx *pctx;
444 struct net_device *dev;
445 __be16 gtph_port;
446 };
447
gtp_push_header(struct sk_buff * skb,struct gtp_pktinfo * pktinfo)448 static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
449 {
450 switch (pktinfo->pctx->gtp_version) {
451 case GTP_V0:
452 pktinfo->gtph_port = htons(GTP0_PORT);
453 gtp0_push_header(skb, pktinfo->pctx);
454 break;
455 case GTP_V1:
456 pktinfo->gtph_port = htons(GTP1U_PORT);
457 gtp1_push_header(skb, pktinfo->pctx);
458 break;
459 }
460 }
461
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)462 static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
463 struct sock *sk, struct iphdr *iph,
464 struct pdp_ctx *pctx, struct rtable *rt,
465 struct flowi4 *fl4,
466 struct net_device *dev)
467 {
468 pktinfo->sk = sk;
469 pktinfo->iph = iph;
470 pktinfo->pctx = pctx;
471 pktinfo->rt = rt;
472 pktinfo->fl4 = *fl4;
473 pktinfo->dev = dev;
474 }
475
gtp_build_skb_ip4(struct sk_buff * skb,struct net_device * dev,struct gtp_pktinfo * pktinfo)476 static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
477 struct gtp_pktinfo *pktinfo)
478 {
479 struct gtp_dev *gtp = netdev_priv(dev);
480 struct pdp_ctx *pctx;
481 struct rtable *rt;
482 struct flowi4 fl4;
483 struct iphdr *iph;
484 __be16 df;
485 int mtu;
486
487 /* Read the IP destination address and resolve the PDP context.
488 * Prepend PDP header with TEI/TID from PDP ctx.
489 */
490 iph = ip_hdr(skb);
491 if (gtp->role == GTP_ROLE_SGSN)
492 pctx = ipv4_pdp_find(gtp, iph->saddr);
493 else
494 pctx = ipv4_pdp_find(gtp, iph->daddr);
495
496 if (!pctx) {
497 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
498 &iph->daddr);
499 return -ENOENT;
500 }
501 netdev_dbg(dev, "found PDP context %p\n", pctx);
502
503 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
504 if (IS_ERR(rt)) {
505 netdev_dbg(dev, "no route to SSGN %pI4\n",
506 &pctx->peer_addr_ip4.s_addr);
507 dev->stats.tx_carrier_errors++;
508 goto err;
509 }
510
511 if (rt->dst.dev == dev) {
512 netdev_dbg(dev, "circular route to SSGN %pI4\n",
513 &pctx->peer_addr_ip4.s_addr);
514 dev->stats.collisions++;
515 goto err_rt;
516 }
517
518 skb_dst_drop(skb);
519
520 /* This is similar to tnl_update_pmtu(). */
521 df = iph->frag_off;
522 if (df) {
523 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
524 sizeof(struct iphdr) - sizeof(struct udphdr);
525 switch (pctx->gtp_version) {
526 case GTP_V0:
527 mtu -= sizeof(struct gtp0_header);
528 break;
529 case GTP_V1:
530 mtu -= sizeof(struct gtp1_header);
531 break;
532 }
533 } else {
534 mtu = dst_mtu(&rt->dst);
535 }
536
537 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
538
539 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
540 mtu < ntohs(iph->tot_len)) {
541 netdev_dbg(dev, "packet too big, fragmentation needed\n");
542 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
543 htonl(mtu));
544 goto err_rt;
545 }
546
547 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
548 gtp_push_header(skb, pktinfo);
549
550 return 0;
551 err_rt:
552 ip_rt_put(rt);
553 err:
554 return -EBADMSG;
555 }
556
gtp_dev_xmit(struct sk_buff * skb,struct net_device * dev)557 static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
558 {
559 unsigned int proto = ntohs(skb->protocol);
560 struct gtp_pktinfo pktinfo;
561 int err;
562
563 /* Ensure there is sufficient headroom. */
564 if (skb_cow_head(skb, dev->needed_headroom))
565 goto tx_err;
566
567 skb_reset_inner_headers(skb);
568
569 /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */
570 rcu_read_lock();
571 switch (proto) {
572 case ETH_P_IP:
573 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
574 break;
575 default:
576 err = -EOPNOTSUPP;
577 break;
578 }
579 rcu_read_unlock();
580
581 if (err < 0)
582 goto tx_err;
583
584 switch (proto) {
585 case ETH_P_IP:
586 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
587 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
588 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
589 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
590 pktinfo.iph->tos,
591 ip4_dst_hoplimit(&pktinfo.rt->dst),
592 0,
593 pktinfo.gtph_port, pktinfo.gtph_port,
594 true, false);
595 break;
596 }
597
598 return NETDEV_TX_OK;
599 tx_err:
600 dev->stats.tx_errors++;
601 dev_kfree_skb(skb);
602 return NETDEV_TX_OK;
603 }
604
605 static const struct net_device_ops gtp_netdev_ops = {
606 .ndo_init = gtp_dev_init,
607 .ndo_uninit = gtp_dev_uninit,
608 .ndo_start_xmit = gtp_dev_xmit,
609 .ndo_get_stats64 = ip_tunnel_get_stats64,
610 };
611
gtp_link_setup(struct net_device * dev)612 static void gtp_link_setup(struct net_device *dev)
613 {
614 dev->netdev_ops = >p_netdev_ops;
615 dev->needs_free_netdev = true;
616
617 dev->hard_header_len = 0;
618 dev->addr_len = 0;
619
620 /* Zero header length. */
621 dev->type = ARPHRD_NONE;
622 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
623
624 dev->priv_flags |= IFF_NO_QUEUE;
625 dev->features |= NETIF_F_LLTX;
626 netif_keep_dst(dev);
627
628 /* Assume largest header, ie. GTPv0. */
629 dev->needed_headroom = LL_MAX_HEADER +
630 sizeof(struct iphdr) +
631 sizeof(struct udphdr) +
632 sizeof(struct gtp0_header);
633 }
634
635 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
636 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
637
gtp_destructor(struct net_device * dev)638 static void gtp_destructor(struct net_device *dev)
639 {
640 struct gtp_dev *gtp = netdev_priv(dev);
641
642 kfree(gtp->addr_hash);
643 kfree(gtp->tid_hash);
644 }
645
gtp_newlink(struct net * src_net,struct net_device * dev,struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)646 static int gtp_newlink(struct net *src_net, struct net_device *dev,
647 struct nlattr *tb[], struct nlattr *data[],
648 struct netlink_ext_ack *extack)
649 {
650 struct gtp_dev *gtp;
651 struct gtp_net *gn;
652 int hashsize, err;
653
654 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
655 return -EINVAL;
656
657 gtp = netdev_priv(dev);
658
659 if (!data[IFLA_GTP_PDP_HASHSIZE]) {
660 hashsize = 1024;
661 } else {
662 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
663 if (!hashsize)
664 hashsize = 1024;
665 }
666
667 err = gtp_hashtable_new(gtp, hashsize);
668 if (err < 0)
669 return err;
670
671 err = gtp_encap_enable(gtp, data);
672 if (err < 0)
673 goto out_hashtable;
674
675 err = register_netdevice(dev);
676 if (err < 0) {
677 netdev_dbg(dev, "failed to register new netdev %d\n", err);
678 goto out_encap;
679 }
680
681 gn = net_generic(dev_net(dev), gtp_net_id);
682 list_add_rcu(>p->list, &gn->gtp_dev_list);
683 dev->priv_destructor = gtp_destructor;
684
685 netdev_dbg(dev, "registered new GTP interface\n");
686
687 return 0;
688
689 out_encap:
690 gtp_encap_disable(gtp);
691 out_hashtable:
692 kfree(gtp->addr_hash);
693 kfree(gtp->tid_hash);
694 return err;
695 }
696
gtp_dellink(struct net_device * dev,struct list_head * head)697 static void gtp_dellink(struct net_device *dev, struct list_head *head)
698 {
699 struct gtp_dev *gtp = netdev_priv(dev);
700 struct pdp_ctx *pctx;
701 int i;
702
703 for (i = 0; i < gtp->hash_size; i++)
704 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
705 pdp_context_delete(pctx);
706
707 list_del_rcu(>p->list);
708 unregister_netdevice_queue(dev, head);
709 }
710
711 static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
712 [IFLA_GTP_FD0] = { .type = NLA_U32 },
713 [IFLA_GTP_FD1] = { .type = NLA_U32 },
714 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
715 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
716 };
717
gtp_validate(struct nlattr * tb[],struct nlattr * data[],struct netlink_ext_ack * extack)718 static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
719 struct netlink_ext_ack *extack)
720 {
721 if (!data)
722 return -EINVAL;
723
724 return 0;
725 }
726
gtp_get_size(const struct net_device * dev)727 static size_t gtp_get_size(const struct net_device *dev)
728 {
729 return nla_total_size(sizeof(__u32)); /* IFLA_GTP_PDP_HASHSIZE */
730 }
731
gtp_fill_info(struct sk_buff * skb,const struct net_device * dev)732 static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
733 {
734 struct gtp_dev *gtp = netdev_priv(dev);
735
736 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
737 goto nla_put_failure;
738
739 return 0;
740
741 nla_put_failure:
742 return -EMSGSIZE;
743 }
744
745 static struct rtnl_link_ops gtp_link_ops __read_mostly = {
746 .kind = "gtp",
747 .maxtype = IFLA_GTP_MAX,
748 .policy = gtp_policy,
749 .priv_size = sizeof(struct gtp_dev),
750 .setup = gtp_link_setup,
751 .validate = gtp_validate,
752 .newlink = gtp_newlink,
753 .dellink = gtp_dellink,
754 .get_size = gtp_get_size,
755 .fill_info = gtp_fill_info,
756 };
757
gtp_hashtable_new(struct gtp_dev * gtp,int hsize)758 static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
759 {
760 int i;
761
762 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
763 GFP_KERNEL | __GFP_NOWARN);
764 if (gtp->addr_hash == NULL)
765 return -ENOMEM;
766
767 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
768 GFP_KERNEL | __GFP_NOWARN);
769 if (gtp->tid_hash == NULL)
770 goto err1;
771
772 gtp->hash_size = hsize;
773
774 for (i = 0; i < hsize; i++) {
775 INIT_HLIST_HEAD(>p->addr_hash[i]);
776 INIT_HLIST_HEAD(>p->tid_hash[i]);
777 }
778 return 0;
779 err1:
780 kfree(gtp->addr_hash);
781 return -ENOMEM;
782 }
783
gtp_encap_enable_socket(int fd,int type,struct gtp_dev * gtp)784 static struct sock *gtp_encap_enable_socket(int fd, int type,
785 struct gtp_dev *gtp)
786 {
787 struct udp_tunnel_sock_cfg tuncfg = {NULL};
788 struct socket *sock;
789 struct sock *sk;
790 int err;
791
792 pr_debug("enable gtp on %d, %d\n", fd, type);
793
794 sock = sockfd_lookup(fd, &err);
795 if (!sock) {
796 pr_debug("gtp socket fd=%d not found\n", fd);
797 return NULL;
798 }
799
800 sk = sock->sk;
801 if (sk->sk_protocol != IPPROTO_UDP ||
802 sk->sk_type != SOCK_DGRAM ||
803 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
804 pr_debug("socket fd=%d not UDP\n", fd);
805 sk = ERR_PTR(-EINVAL);
806 goto out_sock;
807 }
808
809 lock_sock(sk);
810 if (sk->sk_user_data) {
811 sk = ERR_PTR(-EBUSY);
812 goto out_rel_sock;
813 }
814
815 sock_hold(sk);
816
817 tuncfg.sk_user_data = gtp;
818 tuncfg.encap_type = type;
819 tuncfg.encap_rcv = gtp_encap_recv;
820 tuncfg.encap_destroy = gtp_encap_destroy;
821
822 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
823
824 out_rel_sock:
825 release_sock(sock->sk);
826 out_sock:
827 sockfd_put(sock);
828 return sk;
829 }
830
gtp_encap_enable(struct gtp_dev * gtp,struct nlattr * data[])831 static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
832 {
833 struct sock *sk1u = NULL;
834 struct sock *sk0 = NULL;
835 unsigned int role = GTP_ROLE_GGSN;
836
837 if (data[IFLA_GTP_FD0]) {
838 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
839
840 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
841 if (IS_ERR(sk0))
842 return PTR_ERR(sk0);
843 }
844
845 if (data[IFLA_GTP_FD1]) {
846 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
847
848 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
849 if (IS_ERR(sk1u)) {
850 gtp_encap_disable_sock(sk0);
851 return PTR_ERR(sk1u);
852 }
853 }
854
855 if (data[IFLA_GTP_ROLE]) {
856 role = nla_get_u32(data[IFLA_GTP_ROLE]);
857 if (role > GTP_ROLE_SGSN) {
858 gtp_encap_disable_sock(sk0);
859 gtp_encap_disable_sock(sk1u);
860 return -EINVAL;
861 }
862 }
863
864 gtp->sk0 = sk0;
865 gtp->sk1u = sk1u;
866 gtp->role = role;
867
868 return 0;
869 }
870
gtp_find_dev(struct net * src_net,struct nlattr * nla[])871 static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
872 {
873 struct gtp_dev *gtp = NULL;
874 struct net_device *dev;
875 struct net *net;
876
877 /* Examine the link attributes and figure out which network namespace
878 * we are talking about.
879 */
880 if (nla[GTPA_NET_NS_FD])
881 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
882 else
883 net = get_net(src_net);
884
885 if (IS_ERR(net))
886 return NULL;
887
888 /* Check if there's an existing gtpX device to configure */
889 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
890 if (dev && dev->netdev_ops == >p_netdev_ops)
891 gtp = netdev_priv(dev);
892
893 put_net(net);
894 return gtp;
895 }
896
ipv4_pdp_fill(struct pdp_ctx * pctx,struct genl_info * info)897 static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
898 {
899 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
900 pctx->af = AF_INET;
901 pctx->peer_addr_ip4.s_addr =
902 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
903 pctx->ms_addr_ip4.s_addr =
904 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
905
906 switch (pctx->gtp_version) {
907 case GTP_V0:
908 /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow
909 * label needs to be the same for uplink and downlink packets,
910 * so let's annotate this.
911 */
912 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
913 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
914 break;
915 case GTP_V1:
916 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
917 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
918 break;
919 default:
920 break;
921 }
922 }
923
gtp_pdp_add(struct gtp_dev * gtp,struct sock * sk,struct genl_info * info)924 static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
925 struct genl_info *info)
926 {
927 struct pdp_ctx *pctx, *pctx_tid = NULL;
928 struct net_device *dev = gtp->dev;
929 u32 hash_ms, hash_tid = 0;
930 unsigned int version;
931 bool found = false;
932 __be32 ms_addr;
933
934 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
935 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
936 version = nla_get_u32(info->attrs[GTPA_VERSION]);
937
938 pctx = ipv4_pdp_find(gtp, ms_addr);
939 if (pctx)
940 found = true;
941 if (version == GTP_V0)
942 pctx_tid = gtp0_pdp_find(gtp,
943 nla_get_u64(info->attrs[GTPA_TID]));
944 else if (version == GTP_V1)
945 pctx_tid = gtp1_pdp_find(gtp,
946 nla_get_u32(info->attrs[GTPA_I_TEI]));
947 if (pctx_tid)
948 found = true;
949
950 if (found) {
951 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
952 return ERR_PTR(-EEXIST);
953 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
954 return ERR_PTR(-EOPNOTSUPP);
955
956 if (pctx && pctx_tid)
957 return ERR_PTR(-EEXIST);
958 if (!pctx)
959 pctx = pctx_tid;
960
961 ipv4_pdp_fill(pctx, info);
962
963 if (pctx->gtp_version == GTP_V0)
964 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
965 pctx->u.v0.tid, pctx);
966 else if (pctx->gtp_version == GTP_V1)
967 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
968 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
969
970 return pctx;
971
972 }
973
974 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
975 if (pctx == NULL)
976 return ERR_PTR(-ENOMEM);
977
978 sock_hold(sk);
979 pctx->sk = sk;
980 pctx->dev = gtp->dev;
981 ipv4_pdp_fill(pctx, info);
982 atomic_set(&pctx->tx_seq, 0);
983
984 switch (pctx->gtp_version) {
985 case GTP_V0:
986 /* TS 09.60: "The flow label identifies unambiguously a GTP
987 * flow.". We use the tid for this instead, I cannot find a
988 * situation in which this doesn't unambiguosly identify the
989 * PDP context.
990 */
991 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
992 break;
993 case GTP_V1:
994 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
995 break;
996 }
997
998 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
999 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1000
1001 switch (pctx->gtp_version) {
1002 case GTP_V0:
1003 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1004 pctx->u.v0.tid, &pctx->peer_addr_ip4,
1005 &pctx->ms_addr_ip4, pctx);
1006 break;
1007 case GTP_V1:
1008 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1009 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1010 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1011 break;
1012 }
1013
1014 return pctx;
1015 }
1016
pdp_context_free(struct rcu_head * head)1017 static void pdp_context_free(struct rcu_head *head)
1018 {
1019 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1020
1021 sock_put(pctx->sk);
1022 kfree(pctx);
1023 }
1024
pdp_context_delete(struct pdp_ctx * pctx)1025 static void pdp_context_delete(struct pdp_ctx *pctx)
1026 {
1027 hlist_del_rcu(&pctx->hlist_tid);
1028 hlist_del_rcu(&pctx->hlist_addr);
1029 call_rcu(&pctx->rcu_head, pdp_context_free);
1030 }
1031
1032 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation);
1033
gtp_genl_new_pdp(struct sk_buff * skb,struct genl_info * info)1034 static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1035 {
1036 unsigned int version;
1037 struct pdp_ctx *pctx;
1038 struct gtp_dev *gtp;
1039 struct sock *sk;
1040 int err;
1041
1042 if (!info->attrs[GTPA_VERSION] ||
1043 !info->attrs[GTPA_LINK] ||
1044 !info->attrs[GTPA_PEER_ADDRESS] ||
1045 !info->attrs[GTPA_MS_ADDRESS])
1046 return -EINVAL;
1047
1048 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1049
1050 switch (version) {
1051 case GTP_V0:
1052 if (!info->attrs[GTPA_TID] ||
1053 !info->attrs[GTPA_FLOW])
1054 return -EINVAL;
1055 break;
1056 case GTP_V1:
1057 if (!info->attrs[GTPA_I_TEI] ||
1058 !info->attrs[GTPA_O_TEI])
1059 return -EINVAL;
1060 break;
1061
1062 default:
1063 return -EINVAL;
1064 }
1065
1066 rtnl_lock();
1067
1068 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1069 if (!gtp) {
1070 err = -ENODEV;
1071 goto out_unlock;
1072 }
1073
1074 if (version == GTP_V0)
1075 sk = gtp->sk0;
1076 else if (version == GTP_V1)
1077 sk = gtp->sk1u;
1078 else
1079 sk = NULL;
1080
1081 if (!sk) {
1082 err = -ENODEV;
1083 goto out_unlock;
1084 }
1085
1086 pctx = gtp_pdp_add(gtp, sk, info);
1087 if (IS_ERR(pctx)) {
1088 err = PTR_ERR(pctx);
1089 } else {
1090 gtp_tunnel_notify(pctx, GTP_CMD_NEWPDP, GFP_KERNEL);
1091 err = 0;
1092 }
1093
1094 out_unlock:
1095 rtnl_unlock();
1096 return err;
1097 }
1098
gtp_find_pdp_by_link(struct net * net,struct nlattr * nla[])1099 static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1100 struct nlattr *nla[])
1101 {
1102 struct gtp_dev *gtp;
1103
1104 gtp = gtp_find_dev(net, nla);
1105 if (!gtp)
1106 return ERR_PTR(-ENODEV);
1107
1108 if (nla[GTPA_MS_ADDRESS]) {
1109 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1110
1111 return ipv4_pdp_find(gtp, ip);
1112 } else if (nla[GTPA_VERSION]) {
1113 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1114
1115 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1116 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1117 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1118 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1119 }
1120
1121 return ERR_PTR(-EINVAL);
1122 }
1123
gtp_find_pdp(struct net * net,struct nlattr * nla[])1124 static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1125 {
1126 struct pdp_ctx *pctx;
1127
1128 if (nla[GTPA_LINK])
1129 pctx = gtp_find_pdp_by_link(net, nla);
1130 else
1131 pctx = ERR_PTR(-EINVAL);
1132
1133 if (!pctx)
1134 pctx = ERR_PTR(-ENOENT);
1135
1136 return pctx;
1137 }
1138
gtp_genl_del_pdp(struct sk_buff * skb,struct genl_info * info)1139 static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1140 {
1141 struct pdp_ctx *pctx;
1142 int err = 0;
1143
1144 if (!info->attrs[GTPA_VERSION])
1145 return -EINVAL;
1146
1147 rcu_read_lock();
1148
1149 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1150 if (IS_ERR(pctx)) {
1151 err = PTR_ERR(pctx);
1152 goto out_unlock;
1153 }
1154
1155 if (pctx->gtp_version == GTP_V0)
1156 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1157 pctx->u.v0.tid, pctx);
1158 else if (pctx->gtp_version == GTP_V1)
1159 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1160 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1161
1162 gtp_tunnel_notify(pctx, GTP_CMD_DELPDP, GFP_ATOMIC);
1163 pdp_context_delete(pctx);
1164
1165 out_unlock:
1166 rcu_read_unlock();
1167 return err;
1168 }
1169
1170 static struct genl_family gtp_genl_family;
1171
1172 enum gtp_multicast_groups {
1173 GTP_GENL_MCGRP,
1174 };
1175
1176 static const struct genl_multicast_group gtp_genl_mcgrps[] = {
1177 [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME },
1178 };
1179
gtp_genl_fill_info(struct sk_buff * skb,u32 snd_portid,u32 snd_seq,int flags,u32 type,struct pdp_ctx * pctx)1180 static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1181 int flags, u32 type, struct pdp_ctx *pctx)
1182 {
1183 void *genlh;
1184
1185 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
1186 type);
1187 if (genlh == NULL)
1188 goto nlmsg_failure;
1189
1190 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1191 nla_put_u32(skb, GTPA_LINK, pctx->dev->ifindex) ||
1192 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1193 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1194 goto nla_put_failure;
1195
1196 switch (pctx->gtp_version) {
1197 case GTP_V0:
1198 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1199 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1200 goto nla_put_failure;
1201 break;
1202 case GTP_V1:
1203 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1204 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1205 goto nla_put_failure;
1206 break;
1207 }
1208 genlmsg_end(skb, genlh);
1209 return 0;
1210
1211 nlmsg_failure:
1212 nla_put_failure:
1213 genlmsg_cancel(skb, genlh);
1214 return -EMSGSIZE;
1215 }
1216
gtp_tunnel_notify(struct pdp_ctx * pctx,u8 cmd,gfp_t allocation)1217 static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation)
1218 {
1219 struct sk_buff *msg;
1220 int ret;
1221
1222 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, allocation);
1223 if (!msg)
1224 return -ENOMEM;
1225
1226 ret = gtp_genl_fill_info(msg, 0, 0, 0, cmd, pctx);
1227 if (ret < 0) {
1228 nlmsg_free(msg);
1229 return ret;
1230 }
1231
1232 ret = genlmsg_multicast_netns(>p_genl_family, dev_net(pctx->dev), msg,
1233 0, GTP_GENL_MCGRP, GFP_ATOMIC);
1234 return ret;
1235 }
1236
gtp_genl_get_pdp(struct sk_buff * skb,struct genl_info * info)1237 static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1238 {
1239 struct pdp_ctx *pctx = NULL;
1240 struct sk_buff *skb2;
1241 int err;
1242
1243 if (!info->attrs[GTPA_VERSION])
1244 return -EINVAL;
1245
1246 rcu_read_lock();
1247
1248 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1249 if (IS_ERR(pctx)) {
1250 err = PTR_ERR(pctx);
1251 goto err_unlock;
1252 }
1253
1254 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1255 if (skb2 == NULL) {
1256 err = -ENOMEM;
1257 goto err_unlock;
1258 }
1259
1260 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1261 0, info->nlhdr->nlmsg_type, pctx);
1262 if (err < 0)
1263 goto err_unlock_free;
1264
1265 rcu_read_unlock();
1266 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1267
1268 err_unlock_free:
1269 kfree_skb(skb2);
1270 err_unlock:
1271 rcu_read_unlock();
1272 return err;
1273 }
1274
gtp_genl_dump_pdp(struct sk_buff * skb,struct netlink_callback * cb)1275 static int gtp_genl_dump_pdp(struct sk_buff *skb,
1276 struct netlink_callback *cb)
1277 {
1278 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1279 int i, j, bucket = cb->args[0], skip = cb->args[1];
1280 struct net *net = sock_net(skb->sk);
1281 struct pdp_ctx *pctx;
1282 struct gtp_net *gn;
1283
1284 gn = net_generic(net, gtp_net_id);
1285
1286 if (cb->args[4])
1287 return 0;
1288
1289 rcu_read_lock();
1290 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1291 if (last_gtp && last_gtp != gtp)
1292 continue;
1293 else
1294 last_gtp = NULL;
1295
1296 for (i = bucket; i < gtp->hash_size; i++) {
1297 j = 0;
1298 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
1299 hlist_tid) {
1300 if (j >= skip &&
1301 gtp_genl_fill_info(skb,
1302 NETLINK_CB(cb->skb).portid,
1303 cb->nlh->nlmsg_seq,
1304 NLM_F_MULTI,
1305 cb->nlh->nlmsg_type, pctx)) {
1306 cb->args[0] = i;
1307 cb->args[1] = j;
1308 cb->args[2] = (unsigned long)gtp;
1309 goto out;
1310 }
1311 j++;
1312 }
1313 skip = 0;
1314 }
1315 bucket = 0;
1316 }
1317 cb->args[4] = 1;
1318 out:
1319 rcu_read_unlock();
1320 return skb->len;
1321 }
1322
1323 static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1324 [GTPA_LINK] = { .type = NLA_U32, },
1325 [GTPA_VERSION] = { .type = NLA_U32, },
1326 [GTPA_TID] = { .type = NLA_U64, },
1327 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1328 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1329 [GTPA_FLOW] = { .type = NLA_U16, },
1330 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1331 [GTPA_I_TEI] = { .type = NLA_U32, },
1332 [GTPA_O_TEI] = { .type = NLA_U32, },
1333 };
1334
1335 static const struct genl_small_ops gtp_genl_ops[] = {
1336 {
1337 .cmd = GTP_CMD_NEWPDP,
1338 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1339 .doit = gtp_genl_new_pdp,
1340 .flags = GENL_ADMIN_PERM,
1341 },
1342 {
1343 .cmd = GTP_CMD_DELPDP,
1344 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1345 .doit = gtp_genl_del_pdp,
1346 .flags = GENL_ADMIN_PERM,
1347 },
1348 {
1349 .cmd = GTP_CMD_GETPDP,
1350 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1351 .doit = gtp_genl_get_pdp,
1352 .dumpit = gtp_genl_dump_pdp,
1353 .flags = GENL_ADMIN_PERM,
1354 },
1355 };
1356
1357 static struct genl_family gtp_genl_family __ro_after_init = {
1358 .name = "gtp",
1359 .version = 0,
1360 .hdrsize = 0,
1361 .maxattr = GTPA_MAX,
1362 .policy = gtp_genl_policy,
1363 .netnsok = true,
1364 .module = THIS_MODULE,
1365 .small_ops = gtp_genl_ops,
1366 .n_small_ops = ARRAY_SIZE(gtp_genl_ops),
1367 .mcgrps = gtp_genl_mcgrps,
1368 .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps),
1369 };
1370
gtp_net_init(struct net * net)1371 static int __net_init gtp_net_init(struct net *net)
1372 {
1373 struct gtp_net *gn = net_generic(net, gtp_net_id);
1374
1375 INIT_LIST_HEAD(&gn->gtp_dev_list);
1376 return 0;
1377 }
1378
gtp_net_exit(struct net * net)1379 static void __net_exit gtp_net_exit(struct net *net)
1380 {
1381 struct gtp_net *gn = net_generic(net, gtp_net_id);
1382 struct gtp_dev *gtp;
1383 LIST_HEAD(list);
1384
1385 rtnl_lock();
1386 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1387 gtp_dellink(gtp->dev, &list);
1388
1389 unregister_netdevice_many(&list);
1390 rtnl_unlock();
1391 }
1392
1393 static struct pernet_operations gtp_net_ops = {
1394 .init = gtp_net_init,
1395 .exit = gtp_net_exit,
1396 .id = >p_net_id,
1397 .size = sizeof(struct gtp_net),
1398 };
1399
gtp_init(void)1400 static int __init gtp_init(void)
1401 {
1402 int err;
1403
1404 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1405
1406 err = rtnl_link_register(>p_link_ops);
1407 if (err < 0)
1408 goto error_out;
1409
1410 err = genl_register_family(>p_genl_family);
1411 if (err < 0)
1412 goto unreg_rtnl_link;
1413
1414 err = register_pernet_subsys(>p_net_ops);
1415 if (err < 0)
1416 goto unreg_genl_family;
1417
1418 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1419 sizeof(struct pdp_ctx));
1420 return 0;
1421
1422 unreg_genl_family:
1423 genl_unregister_family(>p_genl_family);
1424 unreg_rtnl_link:
1425 rtnl_link_unregister(>p_link_ops);
1426 error_out:
1427 pr_err("error loading GTP module loaded\n");
1428 return err;
1429 }
1430 late_initcall(gtp_init);
1431
gtp_fini(void)1432 static void __exit gtp_fini(void)
1433 {
1434 genl_unregister_family(>p_genl_family);
1435 rtnl_link_unregister(>p_link_ops);
1436 unregister_pernet_subsys(>p_net_ops);
1437
1438 pr_info("GTP module unloaded\n");
1439 }
1440 module_exit(gtp_fini);
1441
1442 MODULE_LICENSE("GPL");
1443 MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1444 MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1445 MODULE_ALIAS_RTNL_LINK("gtp");
1446 MODULE_ALIAS_GENL_FAMILY("gtp");
1447