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16#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
17
18#include <linux/module.h>
19#include <linux/skbuff.h>
20#include <linux/udp.h>
21#include <linux/rculist.h>
22#include <linux/jhash.h>
23#include <linux/if_tunnel.h>
24#include <linux/net.h>
25#include <linux/file.h>
26#include <linux/gtp.h>
27
28#include <net/net_namespace.h>
29#include <net/protocol.h>
30#include <net/ip.h>
31#include <net/udp.h>
32#include <net/udp_tunnel.h>
33#include <net/icmp.h>
34#include <net/xfrm.h>
35#include <net/genetlink.h>
36#include <net/netns/generic.h>
37#include <net/gtp.h>
38
39
40struct pdp_ctx {
41 struct hlist_node hlist_tid;
42 struct hlist_node hlist_addr;
43
44 union {
45 u64 tid;
46 struct {
47 u64 tid;
48 u16 flow;
49 } v0;
50 struct {
51 u32 i_tei;
52 u32 o_tei;
53 } v1;
54 } u;
55 u8 gtp_version;
56 u16 af;
57
58 struct in_addr ms_addr_ip4;
59 struct in_addr sgsn_addr_ip4;
60
61 atomic_t tx_seq;
62 struct rcu_head rcu_head;
63};
64
65
66struct gtp_dev {
67 struct list_head list;
68
69 struct socket *sock0;
70 struct socket *sock1u;
71
72 struct net_device *dev;
73
74 unsigned int hash_size;
75 struct hlist_head *tid_hash;
76 struct hlist_head *addr_hash;
77};
78
79static unsigned int gtp_net_id __read_mostly;
80
81struct gtp_net {
82 struct list_head gtp_dev_list;
83};
84
85static u32 gtp_h_initval;
86
87static inline u32 gtp0_hashfn(u64 tid)
88{
89 u32 *tid32 = (u32 *) &tid;
90 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
91}
92
93static inline u32 gtp1u_hashfn(u32 tid)
94{
95 return jhash_1word(tid, gtp_h_initval);
96}
97
98static inline u32 ipv4_hashfn(__be32 ip)
99{
100 return jhash_1word((__force u32)ip, gtp_h_initval);
101}
102
103
104static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
105{
106 struct hlist_head *head;
107 struct pdp_ctx *pdp;
108
109 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
110
111 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
112 if (pdp->gtp_version == GTP_V0 &&
113 pdp->u.v0.tid == tid)
114 return pdp;
115 }
116 return NULL;
117}
118
119
120static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
121{
122 struct hlist_head *head;
123 struct pdp_ctx *pdp;
124
125 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
126
127 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
128 if (pdp->gtp_version == GTP_V1 &&
129 pdp->u.v1.i_tei == tid)
130 return pdp;
131 }
132 return NULL;
133}
134
135
136static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
137{
138 struct hlist_head *head;
139 struct pdp_ctx *pdp;
140
141 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
142
143 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
144 if (pdp->af == AF_INET &&
145 pdp->ms_addr_ip4.s_addr == ms_addr)
146 return pdp;
147 }
148
149 return NULL;
150}
151
152static bool gtp_check_src_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
153 unsigned int hdrlen)
154{
155 struct iphdr *iph;
156
157 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
158 return false;
159
160 iph = (struct iphdr *)(skb->data + hdrlen);
161
162 return iph->saddr == pctx->ms_addr_ip4.s_addr;
163}
164
165
166
167
168static bool gtp_check_src_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
169 unsigned int hdrlen)
170{
171 switch (ntohs(skb->protocol)) {
172 case ETH_P_IP:
173 return gtp_check_src_ms_ipv4(skb, pctx, hdrlen);
174 }
175 return false;
176}
177
178
179static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
180 bool xnet)
181{
182 unsigned int hdrlen = sizeof(struct udphdr) +
183 sizeof(struct gtp0_header);
184 struct gtp0_header *gtp0;
185 struct pdp_ctx *pctx;
186 int ret = 0;
187
188 if (!pskb_may_pull(skb, hdrlen))
189 return -1;
190
191 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
192
193 if ((gtp0->flags >> 5) != GTP_V0)
194 return 1;
195
196 if (gtp0->type != GTP_TPDU)
197 return 1;
198
199 rcu_read_lock();
200 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
201 if (!pctx) {
202 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
203 ret = -1;
204 goto out_rcu;
205 }
206
207 if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
208 netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
209 ret = -1;
210 goto out_rcu;
211 }
212 rcu_read_unlock();
213
214
215 return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
216out_rcu:
217 rcu_read_unlock();
218 return ret;
219}
220
221static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb,
222 bool xnet)
223{
224 unsigned int hdrlen = sizeof(struct udphdr) +
225 sizeof(struct gtp1_header);
226 struct gtp1_header *gtp1;
227 struct pdp_ctx *pctx;
228 int ret = 0;
229
230 if (!pskb_may_pull(skb, hdrlen))
231 return -1;
232
233 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
234
235 if ((gtp1->flags >> 5) != GTP_V1)
236 return 1;
237
238 if (gtp1->type != GTP_TPDU)
239 return 1;
240
241
242
243
244
245
246
247 if (gtp1->flags & GTP1_F_MASK)
248 hdrlen += 4;
249
250
251 if (!pskb_may_pull(skb, hdrlen))
252 return -1;
253
254 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
255
256 rcu_read_lock();
257 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
258 if (!pctx) {
259 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
260 ret = -1;
261 goto out_rcu;
262 }
263
264 if (!gtp_check_src_ms(skb, pctx, hdrlen)) {
265 netdev_dbg(gtp->dev, "No PDP ctx for this MS\n");
266 ret = -1;
267 goto out_rcu;
268 }
269 rcu_read_unlock();
270
271
272 return iptunnel_pull_header(skb, hdrlen, skb->protocol, xnet);
273out_rcu:
274 rcu_read_unlock();
275 return ret;
276}
277
278static void gtp_encap_disable(struct gtp_dev *gtp)
279{
280 if (gtp->sock0 && gtp->sock0->sk) {
281 udp_sk(gtp->sock0->sk)->encap_type = 0;
282 rcu_assign_sk_user_data(gtp->sock0->sk, NULL);
283 }
284 if (gtp->sock1u && gtp->sock1u->sk) {
285 udp_sk(gtp->sock1u->sk)->encap_type = 0;
286 rcu_assign_sk_user_data(gtp->sock1u->sk, NULL);
287 }
288
289 gtp->sock0 = NULL;
290 gtp->sock1u = NULL;
291}
292
293static void gtp_encap_destroy(struct sock *sk)
294{
295 struct gtp_dev *gtp;
296
297 gtp = rcu_dereference_sk_user_data(sk);
298 if (gtp)
299 gtp_encap_disable(gtp);
300}
301
302
303
304
305static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
306{
307 struct pcpu_sw_netstats *stats;
308 struct gtp_dev *gtp;
309 bool xnet;
310 int ret;
311
312 gtp = rcu_dereference_sk_user_data(sk);
313 if (!gtp)
314 return 1;
315
316 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
317
318 xnet = !net_eq(sock_net(sk), dev_net(gtp->dev));
319
320 switch (udp_sk(sk)->encap_type) {
321 case UDP_ENCAP_GTP0:
322 netdev_dbg(gtp->dev, "received GTP0 packet\n");
323 ret = gtp0_udp_encap_recv(gtp, skb, xnet);
324 break;
325 case UDP_ENCAP_GTP1U:
326 netdev_dbg(gtp->dev, "received GTP1U packet\n");
327 ret = gtp1u_udp_encap_recv(gtp, skb, xnet);
328 break;
329 default:
330 ret = -1;
331 }
332
333 switch (ret) {
334 case 1:
335 netdev_dbg(gtp->dev, "pass up to the process\n");
336 return 1;
337 case 0:
338 netdev_dbg(gtp->dev, "forwarding packet from GGSN to uplink\n");
339 break;
340 case -1:
341 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
342 kfree_skb(skb);
343 return 0;
344 }
345
346
347
348
349
350 skb_reset_network_header(skb);
351
352 skb->dev = gtp->dev;
353
354 stats = this_cpu_ptr(gtp->dev->tstats);
355 u64_stats_update_begin(&stats->syncp);
356 stats->rx_packets++;
357 stats->rx_bytes += skb->len;
358 u64_stats_update_end(&stats->syncp);
359
360 netif_rx(skb);
361
362 return 0;
363}
364
365static int gtp_dev_init(struct net_device *dev)
366{
367 struct gtp_dev *gtp = netdev_priv(dev);
368
369 gtp->dev = dev;
370
371 dev->tstats = alloc_percpu(struct pcpu_sw_netstats);
372 if (!dev->tstats)
373 return -ENOMEM;
374
375 return 0;
376}
377
378static void gtp_dev_uninit(struct net_device *dev)
379{
380 struct gtp_dev *gtp = netdev_priv(dev);
381
382 gtp_encap_disable(gtp);
383 free_percpu(dev->tstats);
384}
385
386static struct rtable *ip4_route_output_gtp(struct net *net, struct flowi4 *fl4,
387 const struct sock *sk, __be32 daddr)
388{
389 memset(fl4, 0, sizeof(*fl4));
390 fl4->flowi4_oif = sk->sk_bound_dev_if;
391 fl4->daddr = daddr;
392 fl4->saddr = inet_sk(sk)->inet_saddr;
393 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
394 fl4->flowi4_proto = sk->sk_protocol;
395
396 return ip_route_output_key(net, fl4);
397}
398
399static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
400{
401 int payload_len = skb->len;
402 struct gtp0_header *gtp0;
403
404 gtp0 = (struct gtp0_header *) skb_push(skb, sizeof(*gtp0));
405
406 gtp0->flags = 0x1e;
407 gtp0->type = GTP_TPDU;
408 gtp0->length = htons(payload_len);
409 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
410 gtp0->flow = htons(pctx->u.v0.flow);
411 gtp0->number = 0xff;
412 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
413 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
414}
415
416static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
417{
418 int payload_len = skb->len;
419 struct gtp1_header *gtp1;
420
421 gtp1 = (struct gtp1_header *) skb_push(skb, sizeof(*gtp1));
422
423
424
425
426
427
428
429 gtp1->flags = 0x30;
430 gtp1->type = GTP_TPDU;
431 gtp1->length = htons(payload_len);
432 gtp1->tid = htonl(pctx->u.v1.o_tei);
433
434
435
436
437}
438
439struct gtp_pktinfo {
440 struct sock *sk;
441 struct iphdr *iph;
442 struct flowi4 fl4;
443 struct rtable *rt;
444 struct pdp_ctx *pctx;
445 struct net_device *dev;
446 __be16 gtph_port;
447};
448
449static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
450{
451 switch (pktinfo->pctx->gtp_version) {
452 case GTP_V0:
453 pktinfo->gtph_port = htons(GTP0_PORT);
454 gtp0_push_header(skb, pktinfo->pctx);
455 break;
456 case GTP_V1:
457 pktinfo->gtph_port = htons(GTP1U_PORT);
458 gtp1_push_header(skb, pktinfo->pctx);
459 break;
460 }
461}
462
463static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
464 struct sock *sk, struct iphdr *iph,
465 struct pdp_ctx *pctx, struct rtable *rt,
466 struct flowi4 *fl4,
467 struct net_device *dev)
468{
469 pktinfo->sk = sk;
470 pktinfo->iph = iph;
471 pktinfo->pctx = pctx;
472 pktinfo->rt = rt;
473 pktinfo->fl4 = *fl4;
474 pktinfo->dev = dev;
475}
476
477static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
478 struct gtp_pktinfo *pktinfo)
479{
480 struct gtp_dev *gtp = netdev_priv(dev);
481 struct pdp_ctx *pctx;
482 struct rtable *rt;
483 struct flowi4 fl4;
484 struct iphdr *iph;
485 struct sock *sk;
486 __be16 df;
487 int mtu;
488
489
490
491
492 iph = ip_hdr(skb);
493 pctx = ipv4_pdp_find(gtp, iph->daddr);
494 if (!pctx) {
495 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
496 &iph->daddr);
497 return -ENOENT;
498 }
499 netdev_dbg(dev, "found PDP context %p\n", pctx);
500
501 switch (pctx->gtp_version) {
502 case GTP_V0:
503 if (gtp->sock0)
504 sk = gtp->sock0->sk;
505 else
506 sk = NULL;
507 break;
508 case GTP_V1:
509 if (gtp->sock1u)
510 sk = gtp->sock1u->sk;
511 else
512 sk = NULL;
513 break;
514 default:
515 return -ENOENT;
516 }
517
518 if (!sk) {
519 netdev_dbg(dev, "no userspace socket is available, skip\n");
520 return -ENOENT;
521 }
522
523 rt = ip4_route_output_gtp(sock_net(sk), &fl4, gtp->sock0->sk,
524 pctx->sgsn_addr_ip4.s_addr);
525 if (IS_ERR(rt)) {
526 netdev_dbg(dev, "no route to SSGN %pI4\n",
527 &pctx->sgsn_addr_ip4.s_addr);
528 dev->stats.tx_carrier_errors++;
529 goto err;
530 }
531
532 if (rt->dst.dev == dev) {
533 netdev_dbg(dev, "circular route to SSGN %pI4\n",
534 &pctx->sgsn_addr_ip4.s_addr);
535 dev->stats.collisions++;
536 goto err_rt;
537 }
538
539 skb_dst_drop(skb);
540
541
542 df = iph->frag_off;
543 if (df) {
544 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
545 sizeof(struct iphdr) - sizeof(struct udphdr);
546 switch (pctx->gtp_version) {
547 case GTP_V0:
548 mtu -= sizeof(struct gtp0_header);
549 break;
550 case GTP_V1:
551 mtu -= sizeof(struct gtp1_header);
552 break;
553 }
554 } else {
555 mtu = dst_mtu(&rt->dst);
556 }
557
558 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
559
560 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
561 mtu < ntohs(iph->tot_len)) {
562 netdev_dbg(dev, "packet too big, fragmentation needed\n");
563 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
564 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
565 htonl(mtu));
566 goto err_rt;
567 }
568
569 gtp_set_pktinfo_ipv4(pktinfo, sk, iph, pctx, rt, &fl4, dev);
570 gtp_push_header(skb, pktinfo);
571
572 return 0;
573err_rt:
574 ip_rt_put(rt);
575err:
576 return -EBADMSG;
577}
578
579static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
580{
581 unsigned int proto = ntohs(skb->protocol);
582 struct gtp_pktinfo pktinfo;
583 int err;
584
585
586 if (skb_cow_head(skb, dev->needed_headroom))
587 goto tx_err;
588
589 skb_reset_inner_headers(skb);
590
591
592 rcu_read_lock();
593 switch (proto) {
594 case ETH_P_IP:
595 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
596 break;
597 default:
598 err = -EOPNOTSUPP;
599 break;
600 }
601 rcu_read_unlock();
602
603 if (err < 0)
604 goto tx_err;
605
606 switch (proto) {
607 case ETH_P_IP:
608 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
609 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
610 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
611 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
612 pktinfo.iph->tos,
613 ip4_dst_hoplimit(&pktinfo.rt->dst),
614 0,
615 pktinfo.gtph_port, pktinfo.gtph_port,
616 true, false);
617 break;
618 }
619
620 return NETDEV_TX_OK;
621tx_err:
622 dev->stats.tx_errors++;
623 dev_kfree_skb(skb);
624 return NETDEV_TX_OK;
625}
626
627static const struct net_device_ops gtp_netdev_ops = {
628 .ndo_init = gtp_dev_init,
629 .ndo_uninit = gtp_dev_uninit,
630 .ndo_start_xmit = gtp_dev_xmit,
631 .ndo_get_stats64 = ip_tunnel_get_stats64,
632};
633
634static void gtp_link_setup(struct net_device *dev)
635{
636 dev->netdev_ops = >p_netdev_ops;
637 dev->destructor = free_netdev;
638
639 dev->hard_header_len = 0;
640 dev->addr_len = 0;
641
642
643 dev->type = ARPHRD_NONE;
644 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
645
646 dev->priv_flags |= IFF_NO_QUEUE;
647 dev->features |= NETIF_F_LLTX;
648 netif_keep_dst(dev);
649
650
651 dev->needed_headroom = LL_MAX_HEADER +
652 sizeof(struct iphdr) +
653 sizeof(struct udphdr) +
654 sizeof(struct gtp0_header);
655}
656
657static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
658static void gtp_hashtable_free(struct gtp_dev *gtp);
659static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
660 int fd_gtp0, int fd_gtp1);
661
662static int gtp_newlink(struct net *src_net, struct net_device *dev,
663 struct nlattr *tb[], struct nlattr *data[])
664{
665 int hashsize, err, fd0, fd1;
666 struct gtp_dev *gtp;
667 struct gtp_net *gn;
668
669 if (!data[IFLA_GTP_FD0] || !data[IFLA_GTP_FD1])
670 return -EINVAL;
671
672 gtp = netdev_priv(dev);
673
674 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
675 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
676
677 err = gtp_encap_enable(dev, gtp, fd0, fd1);
678 if (err < 0)
679 goto out_err;
680
681 if (!data[IFLA_GTP_PDP_HASHSIZE])
682 hashsize = 1024;
683 else
684 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
685
686 err = gtp_hashtable_new(gtp, hashsize);
687 if (err < 0)
688 goto out_encap;
689
690 err = register_netdevice(dev);
691 if (err < 0) {
692 netdev_dbg(dev, "failed to register new netdev %d\n", err);
693 goto out_hashtable;
694 }
695
696 gn = net_generic(dev_net(dev), gtp_net_id);
697 list_add_rcu(>p->list, &gn->gtp_dev_list);
698
699 netdev_dbg(dev, "registered new GTP interface\n");
700
701 return 0;
702
703out_hashtable:
704 gtp_hashtable_free(gtp);
705out_encap:
706 gtp_encap_disable(gtp);
707out_err:
708 return err;
709}
710
711static void gtp_dellink(struct net_device *dev, struct list_head *head)
712{
713 struct gtp_dev *gtp = netdev_priv(dev);
714
715 gtp_encap_disable(gtp);
716 gtp_hashtable_free(gtp);
717 list_del_rcu(>p->list);
718 unregister_netdevice_queue(dev, head);
719}
720
721static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
722 [IFLA_GTP_FD0] = { .type = NLA_U32 },
723 [IFLA_GTP_FD1] = { .type = NLA_U32 },
724 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
725};
726
727static int gtp_validate(struct nlattr *tb[], struct nlattr *data[])
728{
729 if (!data)
730 return -EINVAL;
731
732 return 0;
733}
734
735static size_t gtp_get_size(const struct net_device *dev)
736{
737 return nla_total_size(sizeof(__u32));
738}
739
740static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
741{
742 struct gtp_dev *gtp = netdev_priv(dev);
743
744 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
745 goto nla_put_failure;
746
747 return 0;
748
749nla_put_failure:
750 return -EMSGSIZE;
751}
752
753static struct rtnl_link_ops gtp_link_ops __read_mostly = {
754 .kind = "gtp",
755 .maxtype = IFLA_GTP_MAX,
756 .policy = gtp_policy,
757 .priv_size = sizeof(struct gtp_dev),
758 .setup = gtp_link_setup,
759 .validate = gtp_validate,
760 .newlink = gtp_newlink,
761 .dellink = gtp_dellink,
762 .get_size = gtp_get_size,
763 .fill_info = gtp_fill_info,
764};
765
766static struct net *gtp_genl_get_net(struct net *src_net, struct nlattr *tb[])
767{
768 struct net *net;
769
770
771
772
773 if (tb[GTPA_NET_NS_FD])
774 net = get_net_ns_by_fd(nla_get_u32(tb[GTPA_NET_NS_FD]));
775 else
776 net = get_net(src_net);
777
778 return net;
779}
780
781static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
782{
783 int i;
784
785 gtp->addr_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
786 if (gtp->addr_hash == NULL)
787 return -ENOMEM;
788
789 gtp->tid_hash = kmalloc(sizeof(struct hlist_head) * hsize, GFP_KERNEL);
790 if (gtp->tid_hash == NULL)
791 goto err1;
792
793 gtp->hash_size = hsize;
794
795 for (i = 0; i < hsize; i++) {
796 INIT_HLIST_HEAD(>p->addr_hash[i]);
797 INIT_HLIST_HEAD(>p->tid_hash[i]);
798 }
799 return 0;
800err1:
801 kfree(gtp->addr_hash);
802 return -ENOMEM;
803}
804
805static void gtp_hashtable_free(struct gtp_dev *gtp)
806{
807 struct pdp_ctx *pctx;
808 int i;
809
810 for (i = 0; i < gtp->hash_size; i++) {
811 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
812 hlist_del_rcu(&pctx->hlist_tid);
813 hlist_del_rcu(&pctx->hlist_addr);
814 kfree_rcu(pctx, rcu_head);
815 }
816 }
817 synchronize_rcu();
818 kfree(gtp->addr_hash);
819 kfree(gtp->tid_hash);
820}
821
822static int gtp_encap_enable(struct net_device *dev, struct gtp_dev *gtp,
823 int fd_gtp0, int fd_gtp1)
824{
825 struct udp_tunnel_sock_cfg tuncfg = {NULL};
826 struct socket *sock0, *sock1u;
827 int err;
828
829 netdev_dbg(dev, "enable gtp on %d, %d\n", fd_gtp0, fd_gtp1);
830
831 sock0 = sockfd_lookup(fd_gtp0, &err);
832 if (sock0 == NULL) {
833 netdev_dbg(dev, "socket fd=%d not found (gtp0)\n", fd_gtp0);
834 return -ENOENT;
835 }
836
837 if (sock0->sk->sk_protocol != IPPROTO_UDP) {
838 netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp0);
839 err = -EINVAL;
840 goto err1;
841 }
842
843 sock1u = sockfd_lookup(fd_gtp1, &err);
844 if (sock1u == NULL) {
845 netdev_dbg(dev, "socket fd=%d not found (gtp1u)\n", fd_gtp1);
846 err = -ENOENT;
847 goto err1;
848 }
849
850 if (sock1u->sk->sk_protocol != IPPROTO_UDP) {
851 netdev_dbg(dev, "socket fd=%d not UDP\n", fd_gtp1);
852 err = -EINVAL;
853 goto err2;
854 }
855
856 netdev_dbg(dev, "enable gtp on %p, %p\n", sock0, sock1u);
857
858 gtp->sock0 = sock0;
859 gtp->sock1u = sock1u;
860
861 tuncfg.sk_user_data = gtp;
862 tuncfg.encap_rcv = gtp_encap_recv;
863 tuncfg.encap_destroy = gtp_encap_destroy;
864
865 tuncfg.encap_type = UDP_ENCAP_GTP0;
866 setup_udp_tunnel_sock(sock_net(gtp->sock0->sk), gtp->sock0, &tuncfg);
867
868 tuncfg.encap_type = UDP_ENCAP_GTP1U;
869 setup_udp_tunnel_sock(sock_net(gtp->sock1u->sk), gtp->sock1u, &tuncfg);
870
871 err = 0;
872err2:
873 sockfd_put(sock1u);
874err1:
875 sockfd_put(sock0);
876 return err;
877}
878
879static struct net_device *gtp_find_dev(struct net *net, int ifindex)
880{
881 struct gtp_net *gn = net_generic(net, gtp_net_id);
882 struct gtp_dev *gtp;
883
884 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
885 if (ifindex == gtp->dev->ifindex)
886 return gtp->dev;
887 }
888 return NULL;
889}
890
891static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
892{
893 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
894 pctx->af = AF_INET;
895 pctx->sgsn_addr_ip4.s_addr =
896 nla_get_be32(info->attrs[GTPA_SGSN_ADDRESS]);
897 pctx->ms_addr_ip4.s_addr =
898 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
899
900 switch (pctx->gtp_version) {
901 case GTP_V0:
902
903
904
905
906 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
907 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
908 break;
909 case GTP_V1:
910 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
911 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
912 break;
913 default:
914 break;
915 }
916}
917
918static int ipv4_pdp_add(struct net_device *dev, struct genl_info *info)
919{
920 struct gtp_dev *gtp = netdev_priv(dev);
921 u32 hash_ms, hash_tid = 0;
922 struct pdp_ctx *pctx;
923 bool found = false;
924 __be32 ms_addr;
925
926 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
927 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
928
929 hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) {
930 if (pctx->ms_addr_ip4.s_addr == ms_addr) {
931 found = true;
932 break;
933 }
934 }
935
936 if (found) {
937 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
938 return -EEXIST;
939 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
940 return -EOPNOTSUPP;
941
942 ipv4_pdp_fill(pctx, info);
943
944 if (pctx->gtp_version == GTP_V0)
945 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
946 pctx->u.v0.tid, pctx);
947 else if (pctx->gtp_version == GTP_V1)
948 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
949 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
950
951 return 0;
952
953 }
954
955 pctx = kmalloc(sizeof(struct pdp_ctx), GFP_KERNEL);
956 if (pctx == NULL)
957 return -ENOMEM;
958
959 ipv4_pdp_fill(pctx, info);
960 atomic_set(&pctx->tx_seq, 0);
961
962 switch (pctx->gtp_version) {
963 case GTP_V0:
964
965
966
967
968
969 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
970 break;
971 case GTP_V1:
972 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
973 break;
974 }
975
976 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
977 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
978
979 switch (pctx->gtp_version) {
980 case GTP_V0:
981 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
982 pctx->u.v0.tid, &pctx->sgsn_addr_ip4,
983 &pctx->ms_addr_ip4, pctx);
984 break;
985 case GTP_V1:
986 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
987 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
988 &pctx->sgsn_addr_ip4, &pctx->ms_addr_ip4, pctx);
989 break;
990 }
991
992 return 0;
993}
994
995static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
996{
997 struct net_device *dev;
998 struct net *net;
999
1000 if (!info->attrs[GTPA_VERSION] ||
1001 !info->attrs[GTPA_LINK] ||
1002 !info->attrs[GTPA_SGSN_ADDRESS] ||
1003 !info->attrs[GTPA_MS_ADDRESS])
1004 return -EINVAL;
1005
1006 switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1007 case GTP_V0:
1008 if (!info->attrs[GTPA_TID] ||
1009 !info->attrs[GTPA_FLOW])
1010 return -EINVAL;
1011 break;
1012 case GTP_V1:
1013 if (!info->attrs[GTPA_I_TEI] ||
1014 !info->attrs[GTPA_O_TEI])
1015 return -EINVAL;
1016 break;
1017
1018 default:
1019 return -EINVAL;
1020 }
1021
1022 net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1023 if (IS_ERR(net))
1024 return PTR_ERR(net);
1025
1026
1027 dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1028 if (dev == NULL) {
1029 put_net(net);
1030 return -ENODEV;
1031 }
1032 put_net(net);
1033
1034 return ipv4_pdp_add(dev, info);
1035}
1036
1037static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1038{
1039 struct net_device *dev;
1040 struct pdp_ctx *pctx;
1041 struct gtp_dev *gtp;
1042 struct net *net;
1043
1044 if (!info->attrs[GTPA_VERSION] ||
1045 !info->attrs[GTPA_LINK])
1046 return -EINVAL;
1047
1048 net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1049 if (IS_ERR(net))
1050 return PTR_ERR(net);
1051
1052
1053 dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1054 if (dev == NULL) {
1055 put_net(net);
1056 return -ENODEV;
1057 }
1058 put_net(net);
1059
1060 gtp = netdev_priv(dev);
1061
1062 switch (nla_get_u32(info->attrs[GTPA_VERSION])) {
1063 case GTP_V0:
1064 if (!info->attrs[GTPA_TID])
1065 return -EINVAL;
1066 pctx = gtp0_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_TID]));
1067 break;
1068 case GTP_V1:
1069 if (!info->attrs[GTPA_I_TEI])
1070 return -EINVAL;
1071 pctx = gtp1_pdp_find(gtp, nla_get_u64(info->attrs[GTPA_I_TEI]));
1072 break;
1073
1074 default:
1075 return -EINVAL;
1076 }
1077
1078 if (pctx == NULL)
1079 return -ENOENT;
1080
1081 if (pctx->gtp_version == GTP_V0)
1082 netdev_dbg(dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1083 pctx->u.v0.tid, pctx);
1084 else if (pctx->gtp_version == GTP_V1)
1085 netdev_dbg(dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1086 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1087
1088 hlist_del_rcu(&pctx->hlist_tid);
1089 hlist_del_rcu(&pctx->hlist_addr);
1090 kfree_rcu(pctx, rcu_head);
1091
1092 return 0;
1093}
1094
1095static struct genl_family gtp_genl_family;
1096
1097static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1098 u32 type, struct pdp_ctx *pctx)
1099{
1100 void *genlh;
1101
1102 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0,
1103 type);
1104 if (genlh == NULL)
1105 goto nlmsg_failure;
1106
1107 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1108 nla_put_be32(skb, GTPA_SGSN_ADDRESS, pctx->sgsn_addr_ip4.s_addr) ||
1109 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1110 goto nla_put_failure;
1111
1112 switch (pctx->gtp_version) {
1113 case GTP_V0:
1114 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1115 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1116 goto nla_put_failure;
1117 break;
1118 case GTP_V1:
1119 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1120 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1121 goto nla_put_failure;
1122 break;
1123 }
1124 genlmsg_end(skb, genlh);
1125 return 0;
1126
1127nlmsg_failure:
1128nla_put_failure:
1129 genlmsg_cancel(skb, genlh);
1130 return -EMSGSIZE;
1131}
1132
1133static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1134{
1135 struct pdp_ctx *pctx = NULL;
1136 struct net_device *dev;
1137 struct sk_buff *skb2;
1138 struct gtp_dev *gtp;
1139 u32 gtp_version;
1140 struct net *net;
1141 int err;
1142
1143 if (!info->attrs[GTPA_VERSION] ||
1144 !info->attrs[GTPA_LINK])
1145 return -EINVAL;
1146
1147 gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
1148 switch (gtp_version) {
1149 case GTP_V0:
1150 case GTP_V1:
1151 break;
1152 default:
1153 return -EINVAL;
1154 }
1155
1156 net = gtp_genl_get_net(sock_net(skb->sk), info->attrs);
1157 if (IS_ERR(net))
1158 return PTR_ERR(net);
1159
1160
1161 dev = gtp_find_dev(net, nla_get_u32(info->attrs[GTPA_LINK]));
1162 if (dev == NULL) {
1163 put_net(net);
1164 return -ENODEV;
1165 }
1166 put_net(net);
1167
1168 gtp = netdev_priv(dev);
1169
1170 rcu_read_lock();
1171 if (gtp_version == GTP_V0 &&
1172 info->attrs[GTPA_TID]) {
1173 u64 tid = nla_get_u64(info->attrs[GTPA_TID]);
1174
1175 pctx = gtp0_pdp_find(gtp, tid);
1176 } else if (gtp_version == GTP_V1 &&
1177 info->attrs[GTPA_I_TEI]) {
1178 u32 tid = nla_get_u32(info->attrs[GTPA_I_TEI]);
1179
1180 pctx = gtp1_pdp_find(gtp, tid);
1181 } else if (info->attrs[GTPA_MS_ADDRESS]) {
1182 __be32 ip = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
1183
1184 pctx = ipv4_pdp_find(gtp, ip);
1185 }
1186
1187 if (pctx == NULL) {
1188 err = -ENOENT;
1189 goto err_unlock;
1190 }
1191
1192 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1193 if (skb2 == NULL) {
1194 err = -ENOMEM;
1195 goto err_unlock;
1196 }
1197
1198 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1199 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1200 if (err < 0)
1201 goto err_unlock_free;
1202
1203 rcu_read_unlock();
1204 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1205
1206err_unlock_free:
1207 kfree_skb(skb2);
1208err_unlock:
1209 rcu_read_unlock();
1210 return err;
1211}
1212
1213static int gtp_genl_dump_pdp(struct sk_buff *skb,
1214 struct netlink_callback *cb)
1215{
1216 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1217 struct net *net = sock_net(skb->sk);
1218 struct gtp_net *gn = net_generic(net, gtp_net_id);
1219 unsigned long tid = cb->args[1];
1220 int i, k = cb->args[0], ret;
1221 struct pdp_ctx *pctx;
1222
1223 if (cb->args[4])
1224 return 0;
1225
1226 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1227 if (last_gtp && last_gtp != gtp)
1228 continue;
1229 else
1230 last_gtp = NULL;
1231
1232 for (i = k; i < gtp->hash_size; i++) {
1233 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
1234 if (tid && tid != pctx->u.tid)
1235 continue;
1236 else
1237 tid = 0;
1238
1239 ret = gtp_genl_fill_info(skb,
1240 NETLINK_CB(cb->skb).portid,
1241 cb->nlh->nlmsg_seq,
1242 cb->nlh->nlmsg_type, pctx);
1243 if (ret < 0) {
1244 cb->args[0] = i;
1245 cb->args[1] = pctx->u.tid;
1246 cb->args[2] = (unsigned long)gtp;
1247 goto out;
1248 }
1249 }
1250 }
1251 }
1252 cb->args[4] = 1;
1253out:
1254 return skb->len;
1255}
1256
1257static struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1258 [GTPA_LINK] = { .type = NLA_U32, },
1259 [GTPA_VERSION] = { .type = NLA_U32, },
1260 [GTPA_TID] = { .type = NLA_U64, },
1261 [GTPA_SGSN_ADDRESS] = { .type = NLA_U32, },
1262 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1263 [GTPA_FLOW] = { .type = NLA_U16, },
1264 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1265 [GTPA_I_TEI] = { .type = NLA_U32, },
1266 [GTPA_O_TEI] = { .type = NLA_U32, },
1267};
1268
1269static const struct genl_ops gtp_genl_ops[] = {
1270 {
1271 .cmd = GTP_CMD_NEWPDP,
1272 .doit = gtp_genl_new_pdp,
1273 .policy = gtp_genl_policy,
1274 .flags = GENL_ADMIN_PERM,
1275 },
1276 {
1277 .cmd = GTP_CMD_DELPDP,
1278 .doit = gtp_genl_del_pdp,
1279 .policy = gtp_genl_policy,
1280 .flags = GENL_ADMIN_PERM,
1281 },
1282 {
1283 .cmd = GTP_CMD_GETPDP,
1284 .doit = gtp_genl_get_pdp,
1285 .dumpit = gtp_genl_dump_pdp,
1286 .policy = gtp_genl_policy,
1287 .flags = GENL_ADMIN_PERM,
1288 },
1289};
1290
1291static struct genl_family gtp_genl_family __ro_after_init = {
1292 .name = "gtp",
1293 .version = 0,
1294 .hdrsize = 0,
1295 .maxattr = GTPA_MAX,
1296 .netnsok = true,
1297 .module = THIS_MODULE,
1298 .ops = gtp_genl_ops,
1299 .n_ops = ARRAY_SIZE(gtp_genl_ops),
1300};
1301
1302static int __net_init gtp_net_init(struct net *net)
1303{
1304 struct gtp_net *gn = net_generic(net, gtp_net_id);
1305
1306 INIT_LIST_HEAD(&gn->gtp_dev_list);
1307 return 0;
1308}
1309
1310static void __net_exit gtp_net_exit(struct net *net)
1311{
1312 struct gtp_net *gn = net_generic(net, gtp_net_id);
1313 struct gtp_dev *gtp;
1314 LIST_HEAD(list);
1315
1316 rtnl_lock();
1317 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1318 gtp_dellink(gtp->dev, &list);
1319
1320 unregister_netdevice_many(&list);
1321 rtnl_unlock();
1322}
1323
1324static struct pernet_operations gtp_net_ops = {
1325 .init = gtp_net_init,
1326 .exit = gtp_net_exit,
1327 .id = >p_net_id,
1328 .size = sizeof(struct gtp_net),
1329};
1330
1331static int __init gtp_init(void)
1332{
1333 int err;
1334
1335 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1336
1337 err = rtnl_link_register(>p_link_ops);
1338 if (err < 0)
1339 goto error_out;
1340
1341 err = genl_register_family(>p_genl_family);
1342 if (err < 0)
1343 goto unreg_rtnl_link;
1344
1345 err = register_pernet_subsys(>p_net_ops);
1346 if (err < 0)
1347 goto unreg_genl_family;
1348
1349 pr_info("GTP module loaded (pdp ctx size %Zd bytes)\n",
1350 sizeof(struct pdp_ctx));
1351 return 0;
1352
1353unreg_genl_family:
1354 genl_unregister_family(>p_genl_family);
1355unreg_rtnl_link:
1356 rtnl_link_unregister(>p_link_ops);
1357error_out:
1358 pr_err("error loading GTP module loaded\n");
1359 return err;
1360}
1361late_initcall(gtp_init);
1362
1363static void __exit gtp_fini(void)
1364{
1365 unregister_pernet_subsys(>p_net_ops);
1366 genl_unregister_family(>p_genl_family);
1367 rtnl_link_unregister(>p_link_ops);
1368
1369 pr_info("GTP module unloaded\n");
1370}
1371module_exit(gtp_fini);
1372
1373MODULE_LICENSE("GPL");
1374MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1375MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1376MODULE_ALIAS_RTNL_LINK("gtp");
1377MODULE_ALIAS_GENL_FAMILY("gtp");
1378
