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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 u64 tid;
42 struct {
43 u64 tid;
44 u16 flow;
45 } v0;
46 struct {
47 u32 i_tei;
48 u32 o_tei;
49 } v1;
50 } u;
51 u8 gtp_version;
52 u16 af;
53
54 struct in_addr ms_addr_ip4;
55 struct in_addr peer_addr_ip4;
56
57 struct sock *sk;
58 struct net_device *dev;
59
60 atomic_t tx_seq;
61 struct rcu_head rcu_head;
62};
63
64
65struct gtp_dev {
66 struct list_head list;
67
68 struct sock *sk0;
69 struct sock *sk1u;
70
71 struct net_device *dev;
72
73 unsigned int role;
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 void pdp_context_delete(struct pdp_ctx *pctx);
88
89static inline u32 gtp0_hashfn(u64 tid)
90{
91 u32 *tid32 = (u32 *) &tid;
92 return jhash_2words(tid32[0], tid32[1], gtp_h_initval);
93}
94
95static inline u32 gtp1u_hashfn(u32 tid)
96{
97 return jhash_1word(tid, gtp_h_initval);
98}
99
100static inline u32 ipv4_hashfn(__be32 ip)
101{
102 return jhash_1word((__force u32)ip, gtp_h_initval);
103}
104
105
106static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid)
107{
108 struct hlist_head *head;
109 struct pdp_ctx *pdp;
110
111 head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size];
112
113 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
114 if (pdp->gtp_version == GTP_V0 &&
115 pdp->u.v0.tid == tid)
116 return pdp;
117 }
118 return NULL;
119}
120
121
122static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid)
123{
124 struct hlist_head *head;
125 struct pdp_ctx *pdp;
126
127 head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size];
128
129 hlist_for_each_entry_rcu(pdp, head, hlist_tid) {
130 if (pdp->gtp_version == GTP_V1 &&
131 pdp->u.v1.i_tei == tid)
132 return pdp;
133 }
134 return NULL;
135}
136
137
138static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr)
139{
140 struct hlist_head *head;
141 struct pdp_ctx *pdp;
142
143 head = >p->addr_hash[ipv4_hashfn(ms_addr) % gtp->hash_size];
144
145 hlist_for_each_entry_rcu(pdp, head, hlist_addr) {
146 if (pdp->af == AF_INET &&
147 pdp->ms_addr_ip4.s_addr == ms_addr)
148 return pdp;
149 }
150
151 return NULL;
152}
153
154static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx,
155 unsigned int hdrlen, unsigned int role)
156{
157 struct iphdr *iph;
158
159 if (!pskb_may_pull(skb, hdrlen + sizeof(struct iphdr)))
160 return false;
161
162 iph = (struct iphdr *)(skb->data + hdrlen);
163
164 if (role == GTP_ROLE_SGSN)
165 return iph->daddr == pctx->ms_addr_ip4.s_addr;
166 else
167 return iph->saddr == pctx->ms_addr_ip4.s_addr;
168}
169
170
171
172
173static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx,
174 unsigned int hdrlen, unsigned int role)
175{
176 switch (ntohs(skb->protocol)) {
177 case ETH_P_IP:
178 return gtp_check_ms_ipv4(skb, pctx, hdrlen, role);
179 }
180 return false;
181}
182
183static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb,
184 unsigned int hdrlen, unsigned int role)
185{
186 struct pcpu_sw_netstats *stats;
187
188 if (!gtp_check_ms(skb, pctx, hdrlen, role)) {
189 netdev_dbg(pctx->dev, "No PDP ctx for this MS\n");
190 return 1;
191 }
192
193
194 if (iptunnel_pull_header(skb, hdrlen, skb->protocol,
195 !net_eq(sock_net(pctx->sk), dev_net(pctx->dev))))
196 return -1;
197
198 netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n");
199
200
201
202
203
204 skb_reset_network_header(skb);
205
206 skb->dev = pctx->dev;
207
208 stats = this_cpu_ptr(pctx->dev->tstats);
209 u64_stats_update_begin(&stats->syncp);
210 stats->rx_packets++;
211 stats->rx_bytes += skb->len;
212 u64_stats_update_end(&stats->syncp);
213
214 netif_rx(skb);
215 return 0;
216}
217
218
219static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
220{
221 unsigned int hdrlen = sizeof(struct udphdr) +
222 sizeof(struct gtp0_header);
223 struct gtp0_header *gtp0;
224 struct pdp_ctx *pctx;
225
226 if (!pskb_may_pull(skb, hdrlen))
227 return -1;
228
229 gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr));
230
231 if ((gtp0->flags >> 5) != GTP_V0)
232 return 1;
233
234 if (gtp0->type != GTP_TPDU)
235 return 1;
236
237 pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid));
238 if (!pctx) {
239 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
240 return 1;
241 }
242
243 return gtp_rx(pctx, skb, hdrlen, gtp->role);
244}
245
246static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb)
247{
248 unsigned int hdrlen = sizeof(struct udphdr) +
249 sizeof(struct gtp1_header);
250 struct gtp1_header *gtp1;
251 struct pdp_ctx *pctx;
252
253 if (!pskb_may_pull(skb, hdrlen))
254 return -1;
255
256 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
257
258 if ((gtp1->flags >> 5) != GTP_V1)
259 return 1;
260
261 if (gtp1->type != GTP_TPDU)
262 return 1;
263
264
265
266
267
268
269
270 if (gtp1->flags & GTP1_F_MASK)
271 hdrlen += 4;
272
273
274 if (!pskb_may_pull(skb, hdrlen))
275 return -1;
276
277 gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr));
278
279 pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid));
280 if (!pctx) {
281 netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n", skb);
282 return 1;
283 }
284
285 return gtp_rx(pctx, skb, hdrlen, gtp->role);
286}
287
288static void __gtp_encap_destroy(struct sock *sk)
289{
290 struct gtp_dev *gtp;
291
292 lock_sock(sk);
293 gtp = sk->sk_user_data;
294 if (gtp) {
295 if (gtp->sk0 == sk)
296 gtp->sk0 = NULL;
297 else
298 gtp->sk1u = NULL;
299 udp_sk(sk)->encap_type = 0;
300 rcu_assign_sk_user_data(sk, NULL);
301 sock_put(sk);
302 }
303 release_sock(sk);
304}
305
306static void gtp_encap_destroy(struct sock *sk)
307{
308 rtnl_lock();
309 __gtp_encap_destroy(sk);
310 rtnl_unlock();
311}
312
313static void gtp_encap_disable_sock(struct sock *sk)
314{
315 if (!sk)
316 return;
317
318 __gtp_encap_destroy(sk);
319}
320
321static void gtp_encap_disable(struct gtp_dev *gtp)
322{
323 gtp_encap_disable_sock(gtp->sk0);
324 gtp_encap_disable_sock(gtp->sk1u);
325}
326
327
328
329
330static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb)
331{
332 struct gtp_dev *gtp;
333 int ret = 0;
334
335 gtp = rcu_dereference_sk_user_data(sk);
336 if (!gtp)
337 return 1;
338
339 netdev_dbg(gtp->dev, "encap_recv sk=%p\n", sk);
340
341 switch (udp_sk(sk)->encap_type) {
342 case UDP_ENCAP_GTP0:
343 netdev_dbg(gtp->dev, "received GTP0 packet\n");
344 ret = gtp0_udp_encap_recv(gtp, skb);
345 break;
346 case UDP_ENCAP_GTP1U:
347 netdev_dbg(gtp->dev, "received GTP1U packet\n");
348 ret = gtp1u_udp_encap_recv(gtp, skb);
349 break;
350 default:
351 ret = -1;
352 }
353
354 switch (ret) {
355 case 1:
356 netdev_dbg(gtp->dev, "pass up to the process\n");
357 break;
358 case 0:
359 break;
360 case -1:
361 netdev_dbg(gtp->dev, "GTP packet has been dropped\n");
362 kfree_skb(skb);
363 ret = 0;
364 break;
365 }
366
367 return ret;
368}
369
370static int gtp_dev_init(struct net_device *dev)
371{
372 struct gtp_dev *gtp = netdev_priv(dev);
373
374 gtp->dev = dev;
375
376 dev->tstats = netdev_alloc_pcpu_stats(struct pcpu_sw_netstats);
377 if (!dev->tstats)
378 return -ENOMEM;
379
380 return 0;
381}
382
383static void gtp_dev_uninit(struct net_device *dev)
384{
385 struct gtp_dev *gtp = netdev_priv(dev);
386
387 gtp_encap_disable(gtp);
388 free_percpu(dev->tstats);
389}
390
391static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4,
392 const struct sock *sk,
393 __be32 daddr)
394{
395 memset(fl4, 0, sizeof(*fl4));
396 fl4->flowi4_oif = sk->sk_bound_dev_if;
397 fl4->daddr = daddr;
398 fl4->saddr = inet_sk(sk)->inet_saddr;
399 fl4->flowi4_tos = RT_CONN_FLAGS(sk);
400 fl4->flowi4_proto = sk->sk_protocol;
401
402 return ip_route_output_key(sock_net(sk), fl4);
403}
404
405static inline void gtp0_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
406{
407 int payload_len = skb->len;
408 struct gtp0_header *gtp0;
409
410 gtp0 = skb_push(skb, sizeof(*gtp0));
411
412 gtp0->flags = 0x1e;
413 gtp0->type = GTP_TPDU;
414 gtp0->length = htons(payload_len);
415 gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff);
416 gtp0->flow = htons(pctx->u.v0.flow);
417 gtp0->number = 0xff;
418 gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff;
419 gtp0->tid = cpu_to_be64(pctx->u.v0.tid);
420}
421
422static inline void gtp1_push_header(struct sk_buff *skb, struct pdp_ctx *pctx)
423{
424 int payload_len = skb->len;
425 struct gtp1_header *gtp1;
426
427 gtp1 = skb_push(skb, sizeof(*gtp1));
428
429
430
431
432
433
434
435 gtp1->flags = 0x30;
436 gtp1->type = GTP_TPDU;
437 gtp1->length = htons(payload_len);
438 gtp1->tid = htonl(pctx->u.v1.o_tei);
439
440
441
442
443}
444
445struct gtp_pktinfo {
446 struct sock *sk;
447 struct iphdr *iph;
448 struct flowi4 fl4;
449 struct rtable *rt;
450 struct pdp_ctx *pctx;
451 struct net_device *dev;
452 __be16 gtph_port;
453};
454
455static void gtp_push_header(struct sk_buff *skb, struct gtp_pktinfo *pktinfo)
456{
457 switch (pktinfo->pctx->gtp_version) {
458 case GTP_V0:
459 pktinfo->gtph_port = htons(GTP0_PORT);
460 gtp0_push_header(skb, pktinfo->pctx);
461 break;
462 case GTP_V1:
463 pktinfo->gtph_port = htons(GTP1U_PORT);
464 gtp1_push_header(skb, pktinfo->pctx);
465 break;
466 }
467}
468
469static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo,
470 struct sock *sk, struct iphdr *iph,
471 struct pdp_ctx *pctx, struct rtable *rt,
472 struct flowi4 *fl4,
473 struct net_device *dev)
474{
475 pktinfo->sk = sk;
476 pktinfo->iph = iph;
477 pktinfo->pctx = pctx;
478 pktinfo->rt = rt;
479 pktinfo->fl4 = *fl4;
480 pktinfo->dev = dev;
481}
482
483static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev,
484 struct gtp_pktinfo *pktinfo)
485{
486 struct gtp_dev *gtp = netdev_priv(dev);
487 struct pdp_ctx *pctx;
488 struct rtable *rt;
489 struct flowi4 fl4;
490 struct iphdr *iph;
491 __be16 df;
492 int mtu;
493
494
495
496
497 iph = ip_hdr(skb);
498 if (gtp->role == GTP_ROLE_SGSN)
499 pctx = ipv4_pdp_find(gtp, iph->saddr);
500 else
501 pctx = ipv4_pdp_find(gtp, iph->daddr);
502
503 if (!pctx) {
504 netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n",
505 &iph->daddr);
506 return -ENOENT;
507 }
508 netdev_dbg(dev, "found PDP context %p\n", pctx);
509
510 rt = ip4_route_output_gtp(&fl4, pctx->sk, pctx->peer_addr_ip4.s_addr);
511 if (IS_ERR(rt)) {
512 netdev_dbg(dev, "no route to SSGN %pI4\n",
513 &pctx->peer_addr_ip4.s_addr);
514 dev->stats.tx_carrier_errors++;
515 goto err;
516 }
517
518 if (rt->dst.dev == dev) {
519 netdev_dbg(dev, "circular route to SSGN %pI4\n",
520 &pctx->peer_addr_ip4.s_addr);
521 dev->stats.collisions++;
522 goto err_rt;
523 }
524
525 skb_dst_drop(skb);
526
527
528 df = iph->frag_off;
529 if (df) {
530 mtu = dst_mtu(&rt->dst) - dev->hard_header_len -
531 sizeof(struct iphdr) - sizeof(struct udphdr);
532 switch (pctx->gtp_version) {
533 case GTP_V0:
534 mtu -= sizeof(struct gtp0_header);
535 break;
536 case GTP_V1:
537 mtu -= sizeof(struct gtp1_header);
538 break;
539 }
540 } else {
541 mtu = dst_mtu(&rt->dst);
542 }
543
544 rt->dst.ops->update_pmtu(&rt->dst, NULL, skb, mtu);
545
546 if (!skb_is_gso(skb) && (iph->frag_off & htons(IP_DF)) &&
547 mtu < ntohs(iph->tot_len)) {
548 netdev_dbg(dev, "packet too big, fragmentation needed\n");
549 memset(IPCB(skb), 0, sizeof(*IPCB(skb)));
550 icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
551 htonl(mtu));
552 goto err_rt;
553 }
554
555 gtp_set_pktinfo_ipv4(pktinfo, pctx->sk, iph, pctx, rt, &fl4, dev);
556 gtp_push_header(skb, pktinfo);
557
558 return 0;
559err_rt:
560 ip_rt_put(rt);
561err:
562 return -EBADMSG;
563}
564
565static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev)
566{
567 unsigned int proto = ntohs(skb->protocol);
568 struct gtp_pktinfo pktinfo;
569 int err;
570
571
572 if (skb_cow_head(skb, dev->needed_headroom))
573 goto tx_err;
574
575 skb_reset_inner_headers(skb);
576
577
578 rcu_read_lock();
579 switch (proto) {
580 case ETH_P_IP:
581 err = gtp_build_skb_ip4(skb, dev, &pktinfo);
582 break;
583 default:
584 err = -EOPNOTSUPP;
585 break;
586 }
587 rcu_read_unlock();
588
589 if (err < 0)
590 goto tx_err;
591
592 switch (proto) {
593 case ETH_P_IP:
594 netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n",
595 &pktinfo.iph->saddr, &pktinfo.iph->daddr);
596 udp_tunnel_xmit_skb(pktinfo.rt, pktinfo.sk, skb,
597 pktinfo.fl4.saddr, pktinfo.fl4.daddr,
598 pktinfo.iph->tos,
599 ip4_dst_hoplimit(&pktinfo.rt->dst),
600 0,
601 pktinfo.gtph_port, pktinfo.gtph_port,
602 true, false);
603 break;
604 }
605
606 return NETDEV_TX_OK;
607tx_err:
608 dev->stats.tx_errors++;
609 dev_kfree_skb(skb);
610 return NETDEV_TX_OK;
611}
612
613static const struct net_device_ops gtp_netdev_ops = {
614 .ndo_init = gtp_dev_init,
615 .ndo_uninit = gtp_dev_uninit,
616 .ndo_start_xmit = gtp_dev_xmit,
617 .ndo_get_stats64 = ip_tunnel_get_stats64,
618};
619
620static void gtp_link_setup(struct net_device *dev)
621{
622 dev->netdev_ops = >p_netdev_ops;
623 dev->needs_free_netdev = true;
624
625 dev->hard_header_len = 0;
626 dev->addr_len = 0;
627
628
629 dev->type = ARPHRD_NONE;
630 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
631
632 dev->priv_flags |= IFF_NO_QUEUE;
633 dev->features |= NETIF_F_LLTX;
634 netif_keep_dst(dev);
635
636
637 dev->needed_headroom = LL_MAX_HEADER +
638 sizeof(struct iphdr) +
639 sizeof(struct udphdr) +
640 sizeof(struct gtp0_header);
641}
642
643static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize);
644static void gtp_hashtable_free(struct gtp_dev *gtp);
645static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]);
646
647static int gtp_newlink(struct net *src_net, struct net_device *dev,
648 struct nlattr *tb[], struct nlattr *data[],
649 struct netlink_ext_ack *extack)
650{
651 struct gtp_dev *gtp;
652 struct gtp_net *gn;
653 int hashsize, err;
654
655 if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1])
656 return -EINVAL;
657
658 gtp = netdev_priv(dev);
659
660 err = gtp_encap_enable(gtp, data);
661 if (err < 0)
662 return err;
663
664 if (!data[IFLA_GTP_PDP_HASHSIZE])
665 hashsize = 1024;
666 else
667 hashsize = nla_get_u32(data[IFLA_GTP_PDP_HASHSIZE]);
668
669 err = gtp_hashtable_new(gtp, hashsize);
670 if (err < 0)
671 goto out_encap;
672
673 err = register_netdevice(dev);
674 if (err < 0) {
675 netdev_dbg(dev, "failed to register new netdev %d\n", err);
676 goto out_hashtable;
677 }
678
679 gn = net_generic(dev_net(dev), gtp_net_id);
680 list_add_rcu(>p->list, &gn->gtp_dev_list);
681
682 netdev_dbg(dev, "registered new GTP interface\n");
683
684 return 0;
685
686out_hashtable:
687 gtp_hashtable_free(gtp);
688out_encap:
689 gtp_encap_disable(gtp);
690 return err;
691}
692
693static void gtp_dellink(struct net_device *dev, struct list_head *head)
694{
695 struct gtp_dev *gtp = netdev_priv(dev);
696
697 gtp_hashtable_free(gtp);
698 list_del_rcu(>p->list);
699 unregister_netdevice_queue(dev, head);
700}
701
702static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = {
703 [IFLA_GTP_FD0] = { .type = NLA_U32 },
704 [IFLA_GTP_FD1] = { .type = NLA_U32 },
705 [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 },
706 [IFLA_GTP_ROLE] = { .type = NLA_U32 },
707};
708
709static int gtp_validate(struct nlattr *tb[], struct nlattr *data[],
710 struct netlink_ext_ack *extack)
711{
712 if (!data)
713 return -EINVAL;
714
715 return 0;
716}
717
718static size_t gtp_get_size(const struct net_device *dev)
719{
720 return nla_total_size(sizeof(__u32));
721}
722
723static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev)
724{
725 struct gtp_dev *gtp = netdev_priv(dev);
726
727 if (nla_put_u32(skb, IFLA_GTP_PDP_HASHSIZE, gtp->hash_size))
728 goto nla_put_failure;
729
730 return 0;
731
732nla_put_failure:
733 return -EMSGSIZE;
734}
735
736static struct rtnl_link_ops gtp_link_ops __read_mostly = {
737 .kind = "gtp",
738 .maxtype = IFLA_GTP_MAX,
739 .policy = gtp_policy,
740 .priv_size = sizeof(struct gtp_dev),
741 .setup = gtp_link_setup,
742 .validate = gtp_validate,
743 .newlink = gtp_newlink,
744 .dellink = gtp_dellink,
745 .get_size = gtp_get_size,
746 .fill_info = gtp_fill_info,
747};
748
749static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize)
750{
751 int i;
752
753 gtp->addr_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
754 GFP_KERNEL);
755 if (gtp->addr_hash == NULL)
756 return -ENOMEM;
757
758 gtp->tid_hash = kmalloc_array(hsize, sizeof(struct hlist_head),
759 GFP_KERNEL);
760 if (gtp->tid_hash == NULL)
761 goto err1;
762
763 gtp->hash_size = hsize;
764
765 for (i = 0; i < hsize; i++) {
766 INIT_HLIST_HEAD(>p->addr_hash[i]);
767 INIT_HLIST_HEAD(>p->tid_hash[i]);
768 }
769 return 0;
770err1:
771 kfree(gtp->addr_hash);
772 return -ENOMEM;
773}
774
775static void gtp_hashtable_free(struct gtp_dev *gtp)
776{
777 struct pdp_ctx *pctx;
778 int i;
779
780 for (i = 0; i < gtp->hash_size; i++)
781 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid)
782 pdp_context_delete(pctx);
783
784 synchronize_rcu();
785 kfree(gtp->addr_hash);
786 kfree(gtp->tid_hash);
787}
788
789static struct sock *gtp_encap_enable_socket(int fd, int type,
790 struct gtp_dev *gtp)
791{
792 struct udp_tunnel_sock_cfg tuncfg = {NULL};
793 struct socket *sock;
794 struct sock *sk;
795 int err;
796
797 pr_debug("enable gtp on %d, %d\n", fd, type);
798
799 sock = sockfd_lookup(fd, &err);
800 if (!sock) {
801 pr_debug("gtp socket fd=%d not found\n", fd);
802 return NULL;
803 }
804
805 if (sock->sk->sk_protocol != IPPROTO_UDP) {
806 pr_debug("socket fd=%d not UDP\n", fd);
807 sk = ERR_PTR(-EINVAL);
808 goto out_sock;
809 }
810
811 lock_sock(sock->sk);
812 if (sock->sk->sk_user_data) {
813 sk = ERR_PTR(-EBUSY);
814 goto out_sock;
815 }
816
817 sk = sock->sk;
818 sock_hold(sk);
819
820 tuncfg.sk_user_data = gtp;
821 tuncfg.encap_type = type;
822 tuncfg.encap_rcv = gtp_encap_recv;
823 tuncfg.encap_destroy = gtp_encap_destroy;
824
825 setup_udp_tunnel_sock(sock_net(sock->sk), sock, &tuncfg);
826
827out_sock:
828 release_sock(sock->sk);
829 sockfd_put(sock);
830 return sk;
831}
832
833static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[])
834{
835 struct sock *sk1u = NULL;
836 struct sock *sk0 = NULL;
837 unsigned int role = GTP_ROLE_GGSN;
838
839 if (data[IFLA_GTP_FD0]) {
840 u32 fd0 = nla_get_u32(data[IFLA_GTP_FD0]);
841
842 sk0 = gtp_encap_enable_socket(fd0, UDP_ENCAP_GTP0, gtp);
843 if (IS_ERR(sk0))
844 return PTR_ERR(sk0);
845 }
846
847 if (data[IFLA_GTP_FD1]) {
848 u32 fd1 = nla_get_u32(data[IFLA_GTP_FD1]);
849
850 sk1u = gtp_encap_enable_socket(fd1, UDP_ENCAP_GTP1U, gtp);
851 if (IS_ERR(sk1u)) {
852 if (sk0)
853 gtp_encap_disable_sock(sk0);
854 return PTR_ERR(sk1u);
855 }
856 }
857
858 if (data[IFLA_GTP_ROLE]) {
859 role = nla_get_u32(data[IFLA_GTP_ROLE]);
860 if (role > GTP_ROLE_SGSN) {
861 if (sk0)
862 gtp_encap_disable_sock(sk0);
863 if (sk1u)
864 gtp_encap_disable_sock(sk1u);
865 return -EINVAL;
866 }
867 }
868
869 gtp->sk0 = sk0;
870 gtp->sk1u = sk1u;
871 gtp->role = role;
872
873 return 0;
874}
875
876static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[])
877{
878 struct gtp_dev *gtp = NULL;
879 struct net_device *dev;
880 struct net *net;
881
882
883
884
885 if (nla[GTPA_NET_NS_FD])
886 net = get_net_ns_by_fd(nla_get_u32(nla[GTPA_NET_NS_FD]));
887 else
888 net = get_net(src_net);
889
890 if (IS_ERR(net))
891 return NULL;
892
893
894 dev = dev_get_by_index_rcu(net, nla_get_u32(nla[GTPA_LINK]));
895 if (dev && dev->netdev_ops == >p_netdev_ops)
896 gtp = netdev_priv(dev);
897
898 put_net(net);
899 return gtp;
900}
901
902static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info)
903{
904 pctx->gtp_version = nla_get_u32(info->attrs[GTPA_VERSION]);
905 pctx->af = AF_INET;
906 pctx->peer_addr_ip4.s_addr =
907 nla_get_be32(info->attrs[GTPA_PEER_ADDRESS]);
908 pctx->ms_addr_ip4.s_addr =
909 nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
910
911 switch (pctx->gtp_version) {
912 case GTP_V0:
913
914
915
916
917 pctx->u.v0.tid = nla_get_u64(info->attrs[GTPA_TID]);
918 pctx->u.v0.flow = nla_get_u16(info->attrs[GTPA_FLOW]);
919 break;
920 case GTP_V1:
921 pctx->u.v1.i_tei = nla_get_u32(info->attrs[GTPA_I_TEI]);
922 pctx->u.v1.o_tei = nla_get_u32(info->attrs[GTPA_O_TEI]);
923 break;
924 default:
925 break;
926 }
927}
928
929static int ipv4_pdp_add(struct gtp_dev *gtp, struct sock *sk,
930 struct genl_info *info)
931{
932 struct net_device *dev = gtp->dev;
933 u32 hash_ms, hash_tid = 0;
934 struct pdp_ctx *pctx;
935 bool found = false;
936 __be32 ms_addr;
937
938 ms_addr = nla_get_be32(info->attrs[GTPA_MS_ADDRESS]);
939 hash_ms = ipv4_hashfn(ms_addr) % gtp->hash_size;
940
941 hlist_for_each_entry_rcu(pctx, >p->addr_hash[hash_ms], hlist_addr) {
942 if (pctx->ms_addr_ip4.s_addr == ms_addr) {
943 found = true;
944 break;
945 }
946 }
947
948 if (found) {
949 if (info->nlhdr->nlmsg_flags & NLM_F_EXCL)
950 return -EEXIST;
951 if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE)
952 return -EOPNOTSUPP;
953
954 ipv4_pdp_fill(pctx, info);
955
956 if (pctx->gtp_version == GTP_V0)
957 netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n",
958 pctx->u.v0.tid, pctx);
959 else if (pctx->gtp_version == GTP_V1)
960 netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n",
961 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
962
963 return 0;
964
965 }
966
967 pctx = kmalloc(sizeof(*pctx), GFP_ATOMIC);
968 if (pctx == NULL)
969 return -ENOMEM;
970
971 sock_hold(sk);
972 pctx->sk = sk;
973 pctx->dev = gtp->dev;
974 ipv4_pdp_fill(pctx, info);
975 atomic_set(&pctx->tx_seq, 0);
976
977 switch (pctx->gtp_version) {
978 case GTP_V0:
979
980
981
982
983
984 hash_tid = gtp0_hashfn(pctx->u.v0.tid) % gtp->hash_size;
985 break;
986 case GTP_V1:
987 hash_tid = gtp1u_hashfn(pctx->u.v1.i_tei) % gtp->hash_size;
988 break;
989 }
990
991 hlist_add_head_rcu(&pctx->hlist_addr, >p->addr_hash[hash_ms]);
992 hlist_add_head_rcu(&pctx->hlist_tid, >p->tid_hash[hash_tid]);
993
994 switch (pctx->gtp_version) {
995 case GTP_V0:
996 netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
997 pctx->u.v0.tid, &pctx->peer_addr_ip4,
998 &pctx->ms_addr_ip4, pctx);
999 break;
1000 case GTP_V1:
1001 netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n",
1002 pctx->u.v1.i_tei, pctx->u.v1.o_tei,
1003 &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx);
1004 break;
1005 }
1006
1007 return 0;
1008}
1009
1010static void pdp_context_free(struct rcu_head *head)
1011{
1012 struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head);
1013
1014 sock_put(pctx->sk);
1015 kfree(pctx);
1016}
1017
1018static void pdp_context_delete(struct pdp_ctx *pctx)
1019{
1020 hlist_del_rcu(&pctx->hlist_tid);
1021 hlist_del_rcu(&pctx->hlist_addr);
1022 call_rcu(&pctx->rcu_head, pdp_context_free);
1023}
1024
1025static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info)
1026{
1027 unsigned int version;
1028 struct gtp_dev *gtp;
1029 struct sock *sk;
1030 int err;
1031
1032 if (!info->attrs[GTPA_VERSION] ||
1033 !info->attrs[GTPA_LINK] ||
1034 !info->attrs[GTPA_PEER_ADDRESS] ||
1035 !info->attrs[GTPA_MS_ADDRESS])
1036 return -EINVAL;
1037
1038 version = nla_get_u32(info->attrs[GTPA_VERSION]);
1039
1040 switch (version) {
1041 case GTP_V0:
1042 if (!info->attrs[GTPA_TID] ||
1043 !info->attrs[GTPA_FLOW])
1044 return -EINVAL;
1045 break;
1046 case GTP_V1:
1047 if (!info->attrs[GTPA_I_TEI] ||
1048 !info->attrs[GTPA_O_TEI])
1049 return -EINVAL;
1050 break;
1051
1052 default:
1053 return -EINVAL;
1054 }
1055
1056 rtnl_lock();
1057 rcu_read_lock();
1058
1059 gtp = gtp_find_dev(sock_net(skb->sk), info->attrs);
1060 if (!gtp) {
1061 err = -ENODEV;
1062 goto out_unlock;
1063 }
1064
1065 if (version == GTP_V0)
1066 sk = gtp->sk0;
1067 else if (version == GTP_V1)
1068 sk = gtp->sk1u;
1069 else
1070 sk = NULL;
1071
1072 if (!sk) {
1073 err = -ENODEV;
1074 goto out_unlock;
1075 }
1076
1077 err = ipv4_pdp_add(gtp, sk, info);
1078
1079out_unlock:
1080 rcu_read_unlock();
1081 rtnl_unlock();
1082 return err;
1083}
1084
1085static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net,
1086 struct nlattr *nla[])
1087{
1088 struct gtp_dev *gtp;
1089
1090 gtp = gtp_find_dev(net, nla);
1091 if (!gtp)
1092 return ERR_PTR(-ENODEV);
1093
1094 if (nla[GTPA_MS_ADDRESS]) {
1095 __be32 ip = nla_get_be32(nla[GTPA_MS_ADDRESS]);
1096
1097 return ipv4_pdp_find(gtp, ip);
1098 } else if (nla[GTPA_VERSION]) {
1099 u32 gtp_version = nla_get_u32(nla[GTPA_VERSION]);
1100
1101 if (gtp_version == GTP_V0 && nla[GTPA_TID])
1102 return gtp0_pdp_find(gtp, nla_get_u64(nla[GTPA_TID]));
1103 else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI])
1104 return gtp1_pdp_find(gtp, nla_get_u32(nla[GTPA_I_TEI]));
1105 }
1106
1107 return ERR_PTR(-EINVAL);
1108}
1109
1110static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[])
1111{
1112 struct pdp_ctx *pctx;
1113
1114 if (nla[GTPA_LINK])
1115 pctx = gtp_find_pdp_by_link(net, nla);
1116 else
1117 pctx = ERR_PTR(-EINVAL);
1118
1119 if (!pctx)
1120 pctx = ERR_PTR(-ENOENT);
1121
1122 return pctx;
1123}
1124
1125static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info)
1126{
1127 struct pdp_ctx *pctx;
1128 int err = 0;
1129
1130 if (!info->attrs[GTPA_VERSION])
1131 return -EINVAL;
1132
1133 rcu_read_lock();
1134
1135 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1136 if (IS_ERR(pctx)) {
1137 err = PTR_ERR(pctx);
1138 goto out_unlock;
1139 }
1140
1141 if (pctx->gtp_version == GTP_V0)
1142 netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n",
1143 pctx->u.v0.tid, pctx);
1144 else if (pctx->gtp_version == GTP_V1)
1145 netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n",
1146 pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx);
1147
1148 pdp_context_delete(pctx);
1149
1150out_unlock:
1151 rcu_read_unlock();
1152 return err;
1153}
1154
1155static struct genl_family gtp_genl_family;
1156
1157static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq,
1158 u32 type, struct pdp_ctx *pctx)
1159{
1160 void *genlh;
1161
1162 genlh = genlmsg_put(skb, snd_portid, snd_seq, >p_genl_family, 0,
1163 type);
1164 if (genlh == NULL)
1165 goto nlmsg_failure;
1166
1167 if (nla_put_u32(skb, GTPA_VERSION, pctx->gtp_version) ||
1168 nla_put_be32(skb, GTPA_PEER_ADDRESS, pctx->peer_addr_ip4.s_addr) ||
1169 nla_put_be32(skb, GTPA_MS_ADDRESS, pctx->ms_addr_ip4.s_addr))
1170 goto nla_put_failure;
1171
1172 switch (pctx->gtp_version) {
1173 case GTP_V0:
1174 if (nla_put_u64_64bit(skb, GTPA_TID, pctx->u.v0.tid, GTPA_PAD) ||
1175 nla_put_u16(skb, GTPA_FLOW, pctx->u.v0.flow))
1176 goto nla_put_failure;
1177 break;
1178 case GTP_V1:
1179 if (nla_put_u32(skb, GTPA_I_TEI, pctx->u.v1.i_tei) ||
1180 nla_put_u32(skb, GTPA_O_TEI, pctx->u.v1.o_tei))
1181 goto nla_put_failure;
1182 break;
1183 }
1184 genlmsg_end(skb, genlh);
1185 return 0;
1186
1187nlmsg_failure:
1188nla_put_failure:
1189 genlmsg_cancel(skb, genlh);
1190 return -EMSGSIZE;
1191}
1192
1193static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info)
1194{
1195 struct pdp_ctx *pctx = NULL;
1196 struct sk_buff *skb2;
1197 int err;
1198
1199 if (!info->attrs[GTPA_VERSION])
1200 return -EINVAL;
1201
1202 rcu_read_lock();
1203
1204 pctx = gtp_find_pdp(sock_net(skb->sk), info->attrs);
1205 if (IS_ERR(pctx)) {
1206 err = PTR_ERR(pctx);
1207 goto err_unlock;
1208 }
1209
1210 skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC);
1211 if (skb2 == NULL) {
1212 err = -ENOMEM;
1213 goto err_unlock;
1214 }
1215
1216 err = gtp_genl_fill_info(skb2, NETLINK_CB(skb).portid,
1217 info->snd_seq, info->nlhdr->nlmsg_type, pctx);
1218 if (err < 0)
1219 goto err_unlock_free;
1220
1221 rcu_read_unlock();
1222 return genlmsg_unicast(genl_info_net(info), skb2, info->snd_portid);
1223
1224err_unlock_free:
1225 kfree_skb(skb2);
1226err_unlock:
1227 rcu_read_unlock();
1228 return err;
1229}
1230
1231static int gtp_genl_dump_pdp(struct sk_buff *skb,
1232 struct netlink_callback *cb)
1233{
1234 struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp;
1235 struct net *net = sock_net(skb->sk);
1236 struct gtp_net *gn = net_generic(net, gtp_net_id);
1237 unsigned long tid = cb->args[1];
1238 int i, k = cb->args[0], ret;
1239 struct pdp_ctx *pctx;
1240
1241 if (cb->args[4])
1242 return 0;
1243
1244 list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) {
1245 if (last_gtp && last_gtp != gtp)
1246 continue;
1247 else
1248 last_gtp = NULL;
1249
1250 for (i = k; i < gtp->hash_size; i++) {
1251 hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) {
1252 if (tid && tid != pctx->u.tid)
1253 continue;
1254 else
1255 tid = 0;
1256
1257 ret = gtp_genl_fill_info(skb,
1258 NETLINK_CB(cb->skb).portid,
1259 cb->nlh->nlmsg_seq,
1260 cb->nlh->nlmsg_type, pctx);
1261 if (ret < 0) {
1262 cb->args[0] = i;
1263 cb->args[1] = pctx->u.tid;
1264 cb->args[2] = (unsigned long)gtp;
1265 goto out;
1266 }
1267 }
1268 }
1269 }
1270 cb->args[4] = 1;
1271out:
1272 return skb->len;
1273}
1274
1275static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = {
1276 [GTPA_LINK] = { .type = NLA_U32, },
1277 [GTPA_VERSION] = { .type = NLA_U32, },
1278 [GTPA_TID] = { .type = NLA_U64, },
1279 [GTPA_PEER_ADDRESS] = { .type = NLA_U32, },
1280 [GTPA_MS_ADDRESS] = { .type = NLA_U32, },
1281 [GTPA_FLOW] = { .type = NLA_U16, },
1282 [GTPA_NET_NS_FD] = { .type = NLA_U32, },
1283 [GTPA_I_TEI] = { .type = NLA_U32, },
1284 [GTPA_O_TEI] = { .type = NLA_U32, },
1285};
1286
1287static const struct genl_ops gtp_genl_ops[] = {
1288 {
1289 .cmd = GTP_CMD_NEWPDP,
1290 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1291 .doit = gtp_genl_new_pdp,
1292 .flags = GENL_ADMIN_PERM,
1293 },
1294 {
1295 .cmd = GTP_CMD_DELPDP,
1296 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1297 .doit = gtp_genl_del_pdp,
1298 .flags = GENL_ADMIN_PERM,
1299 },
1300 {
1301 .cmd = GTP_CMD_GETPDP,
1302 .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
1303 .doit = gtp_genl_get_pdp,
1304 .dumpit = gtp_genl_dump_pdp,
1305 .flags = GENL_ADMIN_PERM,
1306 },
1307};
1308
1309static struct genl_family gtp_genl_family __ro_after_init = {
1310 .name = "gtp",
1311 .version = 0,
1312 .hdrsize = 0,
1313 .maxattr = GTPA_MAX,
1314 .policy = gtp_genl_policy,
1315 .netnsok = true,
1316 .module = THIS_MODULE,
1317 .ops = gtp_genl_ops,
1318 .n_ops = ARRAY_SIZE(gtp_genl_ops),
1319};
1320
1321static int __net_init gtp_net_init(struct net *net)
1322{
1323 struct gtp_net *gn = net_generic(net, gtp_net_id);
1324
1325 INIT_LIST_HEAD(&gn->gtp_dev_list);
1326 return 0;
1327}
1328
1329static void __net_exit gtp_net_exit(struct net *net)
1330{
1331 struct gtp_net *gn = net_generic(net, gtp_net_id);
1332 struct gtp_dev *gtp;
1333 LIST_HEAD(list);
1334
1335 rtnl_lock();
1336 list_for_each_entry(gtp, &gn->gtp_dev_list, list)
1337 gtp_dellink(gtp->dev, &list);
1338
1339 unregister_netdevice_many(&list);
1340 rtnl_unlock();
1341}
1342
1343static struct pernet_operations gtp_net_ops = {
1344 .init = gtp_net_init,
1345 .exit = gtp_net_exit,
1346 .id = >p_net_id,
1347 .size = sizeof(struct gtp_net),
1348};
1349
1350static int __init gtp_init(void)
1351{
1352 int err;
1353
1354 get_random_bytes(>p_h_initval, sizeof(gtp_h_initval));
1355
1356 err = rtnl_link_register(>p_link_ops);
1357 if (err < 0)
1358 goto error_out;
1359
1360 err = genl_register_family(>p_genl_family);
1361 if (err < 0)
1362 goto unreg_rtnl_link;
1363
1364 err = register_pernet_subsys(>p_net_ops);
1365 if (err < 0)
1366 goto unreg_genl_family;
1367
1368 pr_info("GTP module loaded (pdp ctx size %zd bytes)\n",
1369 sizeof(struct pdp_ctx));
1370 return 0;
1371
1372unreg_genl_family:
1373 genl_unregister_family(>p_genl_family);
1374unreg_rtnl_link:
1375 rtnl_link_unregister(>p_link_ops);
1376error_out:
1377 pr_err("error loading GTP module loaded\n");
1378 return err;
1379}
1380late_initcall(gtp_init);
1381
1382static void __exit gtp_fini(void)
1383{
1384 genl_unregister_family(>p_genl_family);
1385 rtnl_link_unregister(>p_link_ops);
1386 unregister_pernet_subsys(>p_net_ops);
1387
1388 pr_info("GTP module unloaded\n");
1389}
1390module_exit(gtp_fini);
1391
1392MODULE_LICENSE("GPL");
1393MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>");
1394MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic");
1395MODULE_ALIAS_RTNL_LINK("gtp");
1396MODULE_ALIAS_GENL_FAMILY("gtp");
1397
