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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
36struct pdp_ctx {
37 struct hlist_node hlist_tid;
38 struct hlist_node hlist_addr;
39
40 union {
41 struct {
42 u64 tid;
43 u16 flow;
44 } v0;
45 struct {
46 u32 i_tei;
47 u32 o_tei;
48 } v1;
49 } u;
50 u8 gtp_version;
51 u16 af;
52
53 struct in_addr ms_addr_ip4;
54 struct in_addr peer_addr_ip4;
55
56 struct sock *sk;
57 struct net_device *dev;
58
59 atomic_t tx_seq;
60 struct rcu_head rcu_head;
61};
62
63
64struct 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
78static unsigned int gtp_net_id __read_mostly;
79
80struct gtp_net {
81 struct list_head gtp_dev_list;
82};
83
84static u32 gtp_h_initval;
85
86static void pdp_context_delete(struct pdp_ctx *pctx);
87
88static 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
94static inline u32 gtp1u_hashfn(u32 tid)
95{
96 return jhash_1word(tid, gtp_h_initval);
97}
98
99static inline u32 ipv4_hashfn(__be32 ip)
100{
101 return jhash_1word((__force u32)ip, gtp_h_initval);
102}
103
104
105static 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
121static 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
137static 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
153static 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
170
171
172static 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
182static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
183 unsigned int hdrlen, unsigned int role)
184{
185 struct pcpu_sw_netstats *stats;
186
187 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
188 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
189 return 1;
190 }
191
192
193 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
194 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
195 return -1;
196
197 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
198
199
200
201
202
203 skb_reset_network_header(skb);
204
205 skb->dev = pctx->dev;
206
207 stats = this_cpu_ptr(pctx->dev->tstats);
208 u64_stats_update_begin(&stats->syncp);
209 stats->rx_packets++;
210 stats->rx_bytes += skb->len;
211 u64_stats_update_end(&stats->syncp);
212
213 netif_rx(skb);
214 return 0;
215}
216
217
218static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
219{
220 unsigned int hdrlen = sizeof(struct udphdr) +
221 sizeof(struct gtp0_header);
222 struct gtp0_header *gtp0;
223 struct pdp_ctx *pctx;
224
225 if (!pskb_may_pull(skb, hdrlen))
226 return -1;
227
228 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
229
230 if ((gtp0->flags >> 5) != GTP_V0)
231 return 1;
232
233 if (gtp0->type != GTP_TPDU)
234 return 1;
235
236 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
237 if (!pctx) {
238 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
239 return 1;
240 }
241
242 return gtp_rx(pctx, skb, hdrlen, gtp->role);
243}
244
245static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
246{
247 unsigned int hdrlen = sizeof(struct udphdr) +
248 sizeof(struct gtp1_header);
249 struct gtp1_header *gtp1;
250 struct pdp_ctx *pctx;
251
252 if (!pskb_may_pull(skb, hdrlen))
253 return -1;
254
255 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
256
257 if ((gtp1->flags >> 5) != GTP_V1)
258 return 1;
259
260 if (gtp1->type != GTP_TPDU)
261 return 1;
262
263
264
265
266
267
268
269 if (gtp1->flags & GTP1_F_MASK)
270 hdrlen += 4;
271
272
273 if (!pskb_may_pull(skb, hdrlen))
274 return -1;
275
276 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
277
278 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
279 if (!pctx) {
280 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
281 return 1;
282 }
283
284 return gtp_rx(pctx, skb, hdrlen, gtp->role);
285}
286
287static void __gtp_encap_destroy(struct sock *sk)
288{
289 struct gtp_dev *gtp;
290
291 lock_sock(sk);
292 gtp = sk->sk_user_data;
293 if (gtp) {
294 if (gtp->sk0 == sk)
295 gtp->sk0 = NULL;
296 else
297 gtp->sk1u = NULL;
298 udp_sk(sk)->encap_type = 0;
299 rcu_assign_sk_user_data(sk, NULL);
300 sock_put(sk);
301 }
302 release_sock(sk);
303}
304
305static void gtp_encap_destroy(struct sock *sk)
306{
307 rtnl_lock();
308 __gtp_encap_destroy(sk);
309 rtnl_unlock();
310}
311
312static void gtp_encap_disable_sock(struct sock *sk)
313{
314 if (!sk)
315 return;
316
317 __gtp_encap_destroy(sk);
318}
319
320static void gtp_encap_disable(struct gtp_dev *gtp)
321{
322 gtp_encap_disable_sock(gtp->sk0);
323 gtp_encap_disable_sock(gtp->sk1u);
324}
325
326
327
328
329static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
330{
331 struct gtp_dev *gtp;
332 int ret = 0;
333
334 gtp = rcu_dereference_sk_user_data(sk);
335 if (!gtp)
336 return 1;
337
338 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
339
340 switch (udp_sk(sk)->encap_type) {
341 case UDP_ENCAP_GTP0:
342 netdev_dbg(gtp->dev, "received GTP0 packet\n");
343 ret = gtp0_udp_encap_recv(gtp, skb);
344 break;
345 case UDP_ENCAP_GTP1U:
346 netdev_dbg(gtp->dev, "received GTP1U packet\n");
347 ret = gtp1u_udp_encap_recv(gtp, skb);
348 break;
349 default:
350 ret = -1;
351 }
352
353 switch (ret) {
354 case 1:
355 netdev_dbg(gtp->dev, "pass up to the process\n");
356 break;
357 case 0:
358 break;
359 case -1:
360 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
361 kfree_skb(skb);
362 ret = 0;
363 break;
364 }
365
366 return ret;
367}
368
369static int gtp_dev_init(struct net_device *dev)
370{
371 struct gtp_dev *gtp = netdev_priv(dev);
372
373 gtp->dev = dev;
374
375 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
376 if (!dev->tstats)
377 return -ENOMEM;
378
379 return 0;
380}
381
382static void gtp_dev_uninit(struct net_device *dev)
383{
384 struct gtp_dev *gtp = netdev_priv(dev);
385
386 gtp_encap_disable(gtp);
387 free_percpu(dev->tstats);
388}
389
390static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
391 const struct sock *sk,
392 __be32 daddr)
393{
394 memset(fl4, 0, sizeof(*fl4));
395 fl4->flowi4_oif = sk->sk_bound_dev_if;
396 fl4->daddr = daddr;
397 fl4->saddr = inet_sk(sk)->inet_saddr;
398 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
399 fl4->flowi4_proto = sk->sk_protocol;
400
401 return ip_route_output_key(sock_net(sk), fl4);
402}
403
404static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
405{
406 int payload_len = skb->len;
407 struct gtp0_header *gtp0;
408
409 gtp0 = skb_push(skb, sizeof(*gtp0));
410
411 gtp0->flags = 0x1e;
412 gtp0->type = GTP_TPDU;
413 gtp0->length = htons(payload_len);
414 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
415 gtp0->flow = htons(pctx->u.v0.flow);
416 gtp0->number = 0xff;
417 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
418 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
419}
420
421static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
422{
423 int payload_len = skb->len;
424 struct gtp1_header *gtp1;
425
426 gtp1 = skb_push(skb, sizeof(*gtp1));
427
428
429
430
431
432
433
434 gtp1->flags = 0x30;
435 gtp1->type = GTP_TPDU;
436 gtp1->length = htons(payload_len);
437 gtp1->tid = htonl(pctx->u.v1.o_tei);
438
439
440
441
442}
443
444struct gtp_pktinfo {
445 struct sock *sk;
446 struct iphdr *iph;
447 struct flowi4 fl4;
448 struct rtable *rt;
449 struct pdp_ctx *pctx;
450 struct net_device *dev;
451 __be16 gtph_port;
452};
453
454static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
455{
456 switch (pktinfo->pctx->gtp_version) {
457 case GTP_V0:
458 pktinfo->gtph_port = htons(GTP0_PORT);
459 gtp0_push_header(skb, pktinfo->pctx);
460 break;
461 case GTP_V1:
462 pktinfo->gtph_port = htons(GTP1U_PORT);
463 gtp1_push_header(skb, pktinfo->pctx);
464 break;
465 }
466}
467
468static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
469 struct sock *sk, struct iphdr *iph,
470 struct pdp_ctx *pctx, struct rtable *rt,
471 struct flowi4 *fl4,
472 struct net_device *dev)
473{
474 pktinfo->sk = sk;
475 pktinfo->iph = iph;
476 pktinfo->pctx = pctx;
477 pktinfo->rt = rt;
478 pktinfo->fl4 = *fl4;
479 pktinfo->dev = dev;
480}
481
482static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
483 struct gtp_pktinfo *pktinfo)
484{
485 struct gtp_dev *gtp = netdev_priv(dev);
486 struct pdp_ctx *pctx;
487 struct rtable *rt;
488 struct flowi4 fl4;
489 struct iphdr *iph;
490 __be16 df;
491 int mtu;
492
493
494
495
496 iph = ip_hdr(skb);
497 if (gtp->role == GTP_ROLE_SGSN)
498 pctx = ipv4_pdp_find(gtp, iph->saddr);
499 else
500 pctx = ipv4_pdp_find(gtp, iph->daddr);
501
502 if (!pctx) {
503 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
504 &iph->daddr);
505 return -ENOENT;
506 }
507 netdev_dbg(dev, "found PDP context %p\n", pctx);
508
509 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
510 if (IS_ERR(rt)) {
511 netdev_dbg(dev, "no route to SSGN %pI4\n",
512 &pctx->peer_addr_ip4.s_addr);
513 dev->stats.tx_carrier_errors++;
514 goto err;
515 }
516
517 if (rt->dst.dev == dev) {
518 netdev_dbg(dev, "circular route to SSGN %pI4\n",
519 &pctx->peer_addr_ip4.s_addr);
520 dev->stats.collisions++;
521 goto err_rt;
522 }
523
524 skb_dst_drop(skb);
525
526
527 df = iph->frag_off;
528 if (df) {
529 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
530 sizeof(struct iphdr) - sizeof(struct udphdr);
531 switch (pctx->gtp_version) {
532 case GTP_V0:
533 mtu -= sizeof(struct gtp0_header);
534 break;
535 case GTP_V1:
536 mtu -= sizeof(struct gtp1_header);
537 break;
538 }
539 } else {
540 mtu = dst_mtu(&rt->dst);
541 }
542
543 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu, false);
544
545 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
546 mtu < ntohs(iph->tot_len)) {
547 netdev_dbg(dev, "packet too big, fragmentation needed\n");
548 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
549 icmp_ndo_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
550 htonl(mtu));
551 goto err_rt;
552 }
553
554 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
555 gtp_push_header(skb, pktinfo);
556
557 return 0;
558err_rt:
559 ip_rt_put(rt);
560err:
561 return -EBADMSG;
562}
563
564static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
565{
566 unsigned int proto = ntohs(skb->protocol);
567 struct gtp_pktinfo pktinfo;
568 int err;
569
570
571 if (skb_cow_head(skb, dev->needed_headroom))
572 goto tx_err;
573
574 skb_reset_inner_headers(skb);
575
576
577 rcu_read_lock();
578 switch (proto) {
579 case ETH_P_IP:
580 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
581 break;
582 default:
583 err = -EOPNOTSUPP;
584 break;
585 }
586 rcu_read_unlock();
587
588 if (err < 0)
589 goto tx_err;
590
591 switch (proto) {
592 case ETH_P_IP:
593 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
594 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
595 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
596 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
597 pktinfo.iph->tos,
598 ip4_dst_hoplimit(&pktinfo.rt->dst),
599 0,
600 pktinfo.gtph_port, pktinfo.gtph_port,
601 true, false);
602 break;
603 }
604
605 return NETDEV_TX_OK;
606tx_err:
607 dev->stats.tx_errors++;
608 dev_kfree_skb(skb);
609 return NETDEV_TX_OK;
610}
611
612static const struct net_device_ops gtp_netdev_ops = {
613 .ndo_init = gtp_dev_init,
614 .ndo_uninit = gtp_dev_uninit,
615 .ndo_start_xmit = gtp_dev_xmit,
616 .ndo_get_stats64 = ip_tunnel_get_stats64,
617};
618
619static void gtp_link_setup(struct net_device *dev)
620{
621 dev->netdev_ops = >p_netdev_ops;
622 dev->needs_free_netdev = true;
623
624 dev->hard_header_len = 0;
625 dev->addr_len = 0;
626
627
628 dev->type = ARPHRD_NONE;
629 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
630
631 dev->priv_flags |= IFF_NO_QUEUE;
632 dev->features |= NETIF_F_LLTX;
633 netif_keep_dst(dev);
634
635
636 dev->needed_headroom = LL_MAX_HEADER +
637 sizeof(struct iphdr) +
638 sizeof(struct udphdr) +
639 sizeof(struct gtp0_header);
640}
641
642static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
643static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
644
645static void gtp_destructor(struct net_device *dev)
646{
647 struct gtp_dev *gtp = netdev_priv(dev);
648
649 kfree(gtp->addr_hash);
650 kfree(gtp->tid_hash);
651}
652
653static int gtp_newlink(struct net *src_net, struct net_device *dev,
654 struct nlattr *tb[], struct nlattr *data[],
655 struct netlink_ext_ack *extack)
656{
657 struct gtp_dev *gtp;
658 struct gtp_net *gn;
659 int hashsize, err;
660
661 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
662 return -EINVAL;
663
664 gtp = netdev_priv(dev);
665
666 err = gtp_encap_enable(gtp, data);
667 if (err < 0)
668 return err;
669
670 if (!data[IFLA_GTP_PDP_HASHSIZE]) {
671 hashsize = 1024;
672 } else {
673 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
674 if (!hashsize)
675 hashsize = 1024;
676 }
677
678 err = gtp_hashtable_new(gtp, hashsize);
679 if (err < 0)
680 goto out_encap;
681
682 err = register_netdevice(dev);
683 if (err < 0) {
684 netdev_dbg(dev, "failed to register new netdev %d\n", err);
685 goto out_hashtable;
686 }
687
688 gn = net_generic(dev_net(dev), gtp_net_id);
689 list_add_rcu(>p->list, &gn->gtp_dev_list);
690 dev->priv_destructor = gtp_destructor;
691
692 netdev_dbg(dev, "registered new GTP interface\n");
693
694 return 0;
695
696out_hashtable:
697 kfree(gtp->addr_hash);
698 kfree(gtp->tid_hash);
699out_encap:
700 gtp_encap_disable(gtp);
701 return err;
702}
703
704static void gtp_dellink(struct net_device *dev, struct list_head *head)
705{
706 struct gtp_dev *gtp = netdev_priv(dev);
707 struct pdp_ctx *pctx;
708 int i;
709
710 for (i = 0; i < gtp->hash_size; i++)
711 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
712 pdp_context_delete(pctx);
713
714 list_del_rcu(>p->list);
715 unregister_netdevice_queue(dev, head);
716}
717
718static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
719 [IFLA_GTP_FD0] = { .type = NLA_U32 },
720 [IFLA_GTP_FD1] = { .type = NLA_U32 },
721 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
722 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
723};
724
725static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
726 struct netlink_ext_ack *extack)
727{
728 if (!data)
729 return -EINVAL;
730
731 return 0;
732}
733
734static size_t gtp_get_size(const struct net_device *dev)
735{
736 return nla_total_size(sizeof(__u32));
737}
738
739static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
740{
741 struct gtp_dev *gtp = netdev_priv(dev);
742
743 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
744 goto nla_put_failure;
745
746 return 0;
747
748nla_put_failure:
749 return -EMSGSIZE;
750}
751
752static struct rtnl_link_ops gtp_link_ops __read_mostly = {
753 .kind = "gtp",
754 .maxtype = IFLA_GTP_MAX,
755 .policy = gtp_policy,
756 .priv_size = sizeof(struct gtp_dev),
757 .setup = gtp_link_setup,
758 .validate = gtp_validate,
759 .newlink = gtp_newlink,
760 .dellink = gtp_dellink,
761 .get_size = gtp_get_size,
762 .fill_info = gtp_fill_info,
763};
764
765static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
766{
767 int i;
768
769 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
770 GFP_KERNEL | __GFP_NOWARN);
771 if (gtp->addr_hash == NULL)
772 return -ENOMEM;
773
774 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
775 GFP_KERNEL | __GFP_NOWARN);
776 if (gtp->tid_hash == NULL)
777 goto err1;
778
779 gtp->hash_size = hsize;
780
781 for (i = 0; i < hsize; i++) {
782 INIT_HLIST_HEAD(>p->addr_hash[i]);
783 INIT_HLIST_HEAD(>p->tid_hash[i]);
784 }
785 return 0;
786err1:
787 kfree(gtp->addr_hash);
788 return -ENOMEM;
789}
790
791static struct sock *gtp_encap_enable_socket(int fd, int type,
792 struct gtp_dev *gtp)
793{
794 struct udp_tunnel_sock_cfg tuncfg = {NULL};
795 struct socket *sock;
796 struct sock *sk;
797 int err;
798
799 pr_debug("enable gtp on %d, %d\n", fd, type);
800
801 sock = sockfd_lookup(fd, &err);
802 if (!sock) {
803 pr_debug("gtp socket fd=%d not found\n", fd);
804 return NULL;
805 }
806
807 sk = sock->sk;
808 if (sk->sk_protocol != IPPROTO_UDP ||
809 sk->sk_type != SOCK_DGRAM ||
810 (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) {
811 pr_debug("socket fd=%d not UDP\n", fd);
812 sk = ERR_PTR(-EINVAL);
813 goto out_sock;
814 }
815
816 lock_sock(sk);
817 if (sk->sk_user_data) {
818 sk = ERR_PTR(-EBUSY);
819 goto out_rel_sock;
820 }
821
822 sock_hold(sk);
823
824 tuncfg.sk_user_data = gtp;
825 tuncfg.encap_type = type;
826 tuncfg.encap_rcv = gtp_encap_recv;
827 tuncfg.encap_destroy = gtp_encap_destroy;
828
829 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
830
831out_rel_sock:
832 release_sock(sock->sk);
833out_sock:
834 sockfd_put(sock);
835 return sk;
836}
837
838static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
839{
840 struct sock *sk1u = NULL;
841 struct sock *sk0 = NULL;
842 unsigned int role = GTP_ROLE_GGSN;
843
844 if (data[IFLA_GTP_FD0]) {
845 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
846
847 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
848 if (IS_ERR(sk0))
849 return PTR_ERR(sk0);
850 }
851
852 if (data[IFLA_GTP_FD1]) {
853 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
854
855 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
856 if (IS_ERR(sk1u)) {
857 gtp_encap_disable_sock(sk0);
858 return PTR_ERR(sk1u);
859 }
860 }
861
862 if (data[IFLA_GTP_ROLE]) {
863 role = nla_get_u32(data[IFLA_GTP_ROLE]);
864 if (role > GTP_ROLE_SGSN) {
865 gtp_encap_disable_sock(sk0);
866 gtp_encap_disable_sock(sk1u);
867 return -EINVAL;
868 }
869 }
870
871 gtp->sk0 = sk0;
872 gtp->sk1u = sk1u;
873 gtp->role = role;
874
875 return 0;
876}
877
878static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
879{
880 struct gtp_dev *gtp = NULL;
881 struct net_device *dev;
882 struct net *net;
883
884
885
886
887 if (nla[GTPA_NET_NS_FD])
888 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
889 else
890 net = get_net(src_net);
891
892 if (IS_ERR(net))
893 return NULL;
894
895
896 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
897 if (dev && dev->netdev_ops == >p_netdev_ops)
898 gtp = netdev_priv(dev);
899
900 put_net(net);
901 return gtp;
902}
903
904static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
905{
906 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
907 pctx->af = AF_INET;
908 pctx->peer_addr_ip4.s_addr =
909 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
910 pctx->ms_addr_ip4.s_addr =
911 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
912
913 switch (pctx->gtp_version) {
914 case GTP_V0:
915
916
917
918
919 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
920 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
921 break;
922 case GTP_V1:
923 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
924 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
925 break;
926 default:
927 break;
928 }
929}
930
931static int gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk,
932 struct genl_info *info)
933{
934 struct pdp_ctx *pctx, *pctx_tid = NULL;
935 struct net_device *dev = gtp->dev;
936 u32 hash_ms, hash_tid = 0;
937 unsigned int version;
938 bool found = false;
939 __be32 ms_addr;
940
941 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
942 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
943 version = nla_get_u32(info->attrs[GTPA_VERSION]);
944
945 pctx = ipv4_pdp_find(gtp, ms_addr);
946 if (pctx)
947 found = true;
948 if (version == GTP_V0)
949 pctx_tid = gtp0_pdp_find(gtp,
950 nla_get_u64(info->attrs[GTPA_TID]));
951 else if (version == GTP_V1)
952 pctx_tid = gtp1_pdp_find(gtp,
953 nla_get_u32(info->attrs[GTPA_I_TEI]));
954 if (pctx_tid)
955 found = true;
956
957 if (found) {
958 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
959 return -EEXIST;
960 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
961 return -EOPNOTSUPP;
962
963 if (pctx && pctx_tid)
964 return -EEXIST;
965 if (!pctx)
966 pctx = pctx_tid;
967
968 ipv4_pdp_fill(pctx, info);
969
970 if (pctx->gtp_version == GTP_V0)
971 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
972 pctx->u.v0.tid, pctx);
973 else if (pctx->gtp_version == GTP_V1)
974 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
975 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
976
977 return 0;
978
979 }
980
981 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
982 if (pctx == NULL)
983 return -ENOMEM;
984
985 sock_hold(sk);
986 pctx->sk = sk;
987 pctx->dev = gtp->dev;
988 ipv4_pdp_fill(pctx, info);
989 atomic_set(&pctx->tx_seq, 0);
990
991 switch (pctx->gtp_version) {
992 case GTP_V0:
993
994
995
996
997
998 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
999 break;
1000 case GTP_V1:
1001 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
1002 break;
1003 }
1004
1005 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
1006 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
1007
1008 switch (pctx->gtp_version) {
1009 case GTP_V0:
1010 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1011 pctx->u.v0.tid, &pctx->peer_addr_ip4,
1012 &pctx->ms_addr_ip4, pctx);
1013 break;
1014 case GTP_V1:
1015 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1016 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1017 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1018 break;
1019 }
1020
1021 return 0;
1022}
1023
1024static void pdp_context_free(struct rcu_head *head)
1025{
1026 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1027
1028 sock_put(pctx->sk);
1029 kfree(pctx);
1030}
1031
1032static void pdp_context_delete(struct pdp_ctx *pctx)
1033{
1034 hlist_del_rcu(&pctx->hlist_tid);
1035 hlist_del_rcu(&pctx->hlist_addr);
1036 call_rcu(&pctx->rcu_head, pdp_context_free);
1037}
1038
1039static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1040{
1041 unsigned int version;
1042 struct gtp_dev *gtp;
1043 struct sock *sk;
1044 int err;
1045
1046 if (!info->attrs[GTPA_VERSION] ||
1047 !info->attrs[GTPA_LINK] ||
1048 !info->attrs[GTPA_PEER_ADDRESS] ||
1049 !info->attrs[GTPA_MS_ADDRESS])
1050 return -EINVAL;
1051
1052 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1053
1054 switch (version) {
1055 case GTP_V0:
1056 if (!info->attrs[GTPA_TID] ||
1057 !info->attrs[GTPA_FLOW])
1058 return -EINVAL;
1059 break;
1060 case GTP_V1:
1061 if (!info->attrs[GTPA_I_TEI] ||
1062 !info->attrs[GTPA_O_TEI])
1063 return -EINVAL;
1064 break;
1065
1066 default:
1067 return -EINVAL;
1068 }
1069
1070 rtnl_lock();
1071 rcu_read_lock();
1072
1073 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1074 if (!gtp) {
1075 err = -ENODEV;
1076 goto out_unlock;
1077 }
1078
1079 if (version == GTP_V0)
1080 sk = gtp->sk0;
1081 else if (version == GTP_V1)
1082 sk = gtp->sk1u;
1083 else
1084 sk = NULL;
1085
1086 if (!sk) {
1087 err = -ENODEV;
1088 goto out_unlock;
1089 }
1090
1091 err = gtp_pdp_add(gtp, sk, info);
1092
1093out_unlock:
1094 rcu_read_unlock();
1095 rtnl_unlock();
1096 return err;
1097}
1098
1099static 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
1124static 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
1139static 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 pdp_context_delete(pctx);
1163
1164out_unlock:
1165 rcu_read_unlock();
1166 return err;
1167}
1168
1169static struct genl_family gtp_genl_family;
1170
1171static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1172 int flags, u32 type, struct pdp_ctx *pctx)
1173{
1174 void *genlh;
1175
1176 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, flags,
1177 type);
1178 if (genlh == NULL)
1179 goto nlmsg_failure;
1180
1181 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1182 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1183 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1184 goto nla_put_failure;
1185
1186 switch (pctx->gtp_version) {
1187 case GTP_V0:
1188 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1189 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1190 goto nla_put_failure;
1191 break;
1192 case GTP_V1:
1193 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1194 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1195 goto nla_put_failure;
1196 break;
1197 }
1198 genlmsg_end(skb, genlh);
1199 return 0;
1200
1201nlmsg_failure:
1202nla_put_failure:
1203 genlmsg_cancel(skb, genlh);
1204 return -EMSGSIZE;
1205}
1206
1207static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1208{
1209 struct pdp_ctx *pctx = NULL;
1210 struct sk_buff *skb2;
1211 int err;
1212
1213 if (!info->attrs[GTPA_VERSION])
1214 return -EINVAL;
1215
1216 rcu_read_lock();
1217
1218 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1219 if (IS_ERR(pctx)) {
1220 err = PTR_ERR(pctx);
1221 goto err_unlock;
1222 }
1223
1224 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1225 if (skb2 == NULL) {
1226 err = -ENOMEM;
1227 goto err_unlock;
1228 }
1229
1230 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid, info->snd_seq,
1231 0, info->nlhdr->nlmsg_type, pctx);
1232 if (err < 0)
1233 goto err_unlock_free;
1234
1235 rcu_read_unlock();
1236 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1237
1238err_unlock_free:
1239 kfree_skb(skb2);
1240err_unlock:
1241 rcu_read_unlock();
1242 return err;
1243}
1244
1245static int gtp_genl_dump_pdp(struct sk_buff *skb,
1246 struct netlink_callback *cb)
1247{
1248 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1249 int i, j, bucket = cb->args[0], skip = cb->args[1];
1250 struct net *net = sock_net(skb->sk);
1251 struct pdp_ctx *pctx;
1252 struct gtp_net *gn;
1253
1254 gn = net_generic(net, gtp_net_id);
1255
1256 if (cb->args[4])
1257 return 0;
1258
1259 rcu_read_lock();
1260 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1261 if (last_gtp && last_gtp != gtp)
1262 continue;
1263 else
1264 last_gtp = NULL;
1265
1266 for (i = bucket; i < gtp->hash_size; i++) {
1267 j = 0;
1268 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i],
1269 hlist_tid) {
1270 if (j >= skip &&
1271 gtp_genl_fill_info(skb,
1272 NETLINK_CB(cb->skb).portid,
1273 cb->nlh->nlmsg_seq,
1274 NLM_F_MULTI,
1275 cb->nlh->nlmsg_type, pctx)) {
1276 cb->args[0] = i;
1277 cb->args[1] = j;
1278 cb->args[2] = (unsigned long)gtp;
1279 goto out;
1280 }
1281 j++;
1282 }
1283 skip = 0;
1284 }
1285 bucket = 0;
1286 }
1287 cb->args[4] = 1;
1288out:
1289 rcu_read_unlock();
1290 return skb->len;
1291}
1292
1293static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1294 [GTPA_LINK] = { .type = NLA_U32, },
1295 [GTPA_VERSION] = { .type = NLA_U32, },
1296 [GTPA_TID] = { .type = NLA_U64, },
1297 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1298 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1299 [GTPA_FLOW] = { .type = NLA_U16, },
1300 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1301 [GTPA_I_TEI] = { .type = NLA_U32, },
1302 [GTPA_O_TEI] = { .type = NLA_U32, },
1303};
1304
1305static const struct genl_ops gtp_genl_ops[] = {
1306 {
1307 .cmd = GTP_CMD_NEWPDP,
1308 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1309 .doit = gtp_genl_new_pdp,
1310 .flags = GENL_ADMIN_PERM,
1311 },
1312 {
1313 .cmd = GTP_CMD_DELPDP,
1314 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1315 .doit = gtp_genl_del_pdp,
1316 .flags = GENL_ADMIN_PERM,
1317 },
1318 {
1319 .cmd = GTP_CMD_GETPDP,
1320 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1321 .doit = gtp_genl_get_pdp,
1322 .dumpit = gtp_genl_dump_pdp,
1323 .flags = GENL_ADMIN_PERM,
1324 },
1325};
1326
1327static struct genl_family gtp_genl_family __ro_after_init = {
1328 .name = "gtp",
1329 .version = 0,
1330 .hdrsize = 0,
1331 .maxattr = GTPA_MAX,
1332 .policy = gtp_genl_policy,
1333 .netnsok = true,
1334 .module = THIS_MODULE,
1335 .ops = gtp_genl_ops,
1336 .n_ops = ARRAY_SIZE(gtp_genl_ops),
1337};
1338
1339static int __net_init gtp_net_init(struct net *net)
1340{
1341 struct gtp_net *gn = net_generic(net, gtp_net_id);
1342
1343 INIT_LIST_HEAD(&gn->gtp_dev_list);
1344 return 0;
1345}
1346
1347static void __net_exit gtp_net_exit(struct net *net)
1348{
1349 struct gtp_net *gn = net_generic(net, gtp_net_id);
1350 struct gtp_dev *gtp;
1351 LIST_HEAD(list);
1352
1353 rtnl_lock();
1354 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1355 gtp_dellink(gtp->dev, &list);
1356
1357 unregister_netdevice_many(&list);
1358 rtnl_unlock();
1359}
1360
1361static struct pernet_operations gtp_net_ops = {
1362 .init = gtp_net_init,
1363 .exit = gtp_net_exit,
1364 .id = >p_net_id,
1365 .size = sizeof(struct gtp_net),
1366};
1367
1368static int __init gtp_init(void)
1369{
1370 int err;
1371
1372 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1373
1374 err = rtnl_link_register(>p_link_ops);
1375 if (err < 0)
1376 goto error_out;
1377
1378 err = genl_register_family(>p_genl_family);
1379 if (err < 0)
1380 goto unreg_rtnl_link;
1381
1382 err = register_pernet_subsys(>p_net_ops);
1383 if (err < 0)
1384 goto unreg_genl_family;
1385
1386 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1387 sizeof(struct pdp_ctx));
1388 return 0;
1389
1390unreg_genl_family:
1391 genl_unregister_family(>p_genl_family);
1392unreg_rtnl_link:
1393 rtnl_link_unregister(>p_link_ops);
1394error_out:
1395 pr_err("error loading GTP module loaded\n");
1396 return err;
1397}
1398late_initcall(gtp_init);
1399
1400static void __exit gtp_fini(void)
1401{
1402 genl_unregister_family(>p_genl_family);
1403 rtnl_link_unregister(>p_link_ops);
1404 unregister_pernet_subsys(>p_net_ops);
1405
1406 pr_info("GTP module unloaded\n");
1407}
1408module_exit(gtp_fini);
1409
1410MODULE_LICENSE("GPL");
1411MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1412MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1413MODULE_ALIAS_RTNL_LINK("gtp");
1414MODULE_ALIAS_GENL_FAMILY("gtp");
1415
