1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* GTP according to GSM TS 09.60 / 3GPP TS 29.060 |
3 | * |
4 | * (C) 2012-2014 by sysmocom - s.f.m.c. GmbH |
5 | * (C) 2016 by Pablo Neira Ayuso <pablo@netfilter.org> |
6 | * |
7 | * Author: Harald Welte <hwelte@sysmocom.de> |
8 | * Pablo Neira Ayuso <pablo@netfilter.org> |
9 | * Andreas Schultz <aschultz@travelping.com> |
10 | */ |
11 | |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | |
14 | #include <linux/module.h> |
15 | #include <linux/skbuff.h> |
16 | #include <linux/udp.h> |
17 | #include <linux/rculist.h> |
18 | #include <linux/jhash.h> |
19 | #include <linux/if_tunnel.h> |
20 | #include <linux/net.h> |
21 | #include <linux/file.h> |
22 | #include <linux/gtp.h> |
23 | |
24 | #include <net/net_namespace.h> |
25 | #include <net/protocol.h> |
26 | #include <net/ip.h> |
27 | #include <net/udp.h> |
28 | #include <net/udp_tunnel.h> |
29 | #include <net/icmp.h> |
30 | #include <net/xfrm.h> |
31 | #include <net/genetlink.h> |
32 | #include <net/netns/generic.h> |
33 | #include <net/gtp.h> |
34 | |
35 | /* An active session for the subscriber. */ |
36 | struct pdp_ctx { |
37 | struct hlist_node hlist_tid; |
38 | struct hlist_node hlist_addr; |
39 | |
40 | union { |
41 | struct { |
42 | u64 tid; |
43 | u16 flow; |
44 | } v0; |
45 | struct { |
46 | u32 i_tei; |
47 | u32 o_tei; |
48 | } v1; |
49 | } u; |
50 | u8 gtp_version; |
51 | u16 af; |
52 | |
53 | struct in_addr ms_addr_ip4; |
54 | struct in_addr peer_addr_ip4; |
55 | |
56 | struct sock *sk; |
57 | struct net_device *dev; |
58 | |
59 | atomic_t tx_seq; |
60 | struct rcu_head rcu_head; |
61 | }; |
62 | |
63 | /* One instance of the GTP device. */ |
64 | struct gtp_dev { |
65 | struct list_head list; |
66 | |
67 | struct sock *sk0; |
68 | struct sock *sk1u; |
69 | u8 sk_created; |
70 | |
71 | struct net_device *dev; |
72 | struct net *net; |
73 | |
74 | unsigned int role; |
75 | unsigned int hash_size; |
76 | struct hlist_head *tid_hash; |
77 | struct hlist_head *addr_hash; |
78 | |
79 | u8 restart_count; |
80 | }; |
81 | |
82 | struct echo_info { |
83 | struct in_addr ms_addr_ip4; |
84 | struct in_addr peer_addr_ip4; |
85 | u8 gtp_version; |
86 | }; |
87 | |
88 | static unsigned int gtp_net_id __read_mostly; |
89 | |
90 | struct gtp_net { |
91 | struct list_head gtp_dev_list; |
92 | }; |
93 | |
94 | static u32 gtp_h_initval; |
95 | |
96 | static struct genl_family gtp_genl_family; |
97 | |
98 | enum gtp_multicast_groups { |
99 | GTP_GENL_MCGRP, |
100 | }; |
101 | |
102 | static const struct genl_multicast_group gtp_genl_mcgrps[] = { |
103 | [GTP_GENL_MCGRP] = { .name = GTP_GENL_MCGRP_NAME }, |
104 | }; |
105 | |
106 | static void pdp_context_delete(struct pdp_ctx *pctx); |
107 | |
108 | static inline u32 gtp0_hashfn(u64 tid) |
109 | { |
110 | u32 *tid32 = (u32 *) &tid; |
111 | return jhash_2words(a: tid32[0], b: tid32[1], initval: gtp_h_initval); |
112 | } |
113 | |
114 | static inline u32 gtp1u_hashfn(u32 tid) |
115 | { |
116 | return jhash_1word(a: tid, initval: gtp_h_initval); |
117 | } |
118 | |
119 | static inline u32 ipv4_hashfn(__be32 ip) |
120 | { |
121 | return jhash_1word(a: (__force u32)ip, initval: gtp_h_initval); |
122 | } |
123 | |
124 | /* Resolve a PDP context structure based on the 64bit TID. */ |
125 | static struct pdp_ctx *gtp0_pdp_find(struct gtp_dev *gtp, u64 tid) |
126 | { |
127 | struct hlist_head *head; |
128 | struct pdp_ctx *pdp; |
129 | |
130 | head = >p->tid_hash[gtp0_hashfn(tid) % gtp->hash_size]; |
131 | |
132 | hlist_for_each_entry_rcu(pdp, head, hlist_tid) { |
133 | if (pdp->gtp_version == GTP_V0 && |
134 | pdp->u.v0.tid == tid) |
135 | return pdp; |
136 | } |
137 | return NULL; |
138 | } |
139 | |
140 | /* Resolve a PDP context structure based on the 32bit TEI. */ |
141 | static struct pdp_ctx *gtp1_pdp_find(struct gtp_dev *gtp, u32 tid) |
142 | { |
143 | struct hlist_head *head; |
144 | struct pdp_ctx *pdp; |
145 | |
146 | head = >p->tid_hash[gtp1u_hashfn(tid) % gtp->hash_size]; |
147 | |
148 | hlist_for_each_entry_rcu(pdp, head, hlist_tid) { |
149 | if (pdp->gtp_version == GTP_V1 && |
150 | pdp->u.v1.i_tei == tid) |
151 | return pdp; |
152 | } |
153 | return NULL; |
154 | } |
155 | |
156 | /* Resolve a PDP context based on IPv4 address of MS. */ |
157 | static struct pdp_ctx *ipv4_pdp_find(struct gtp_dev *gtp, __be32 ms_addr) |
158 | { |
159 | struct hlist_head *head; |
160 | struct pdp_ctx *pdp; |
161 | |
162 | head = >p->addr_hash[ipv4_hashfn(ip: ms_addr) % gtp->hash_size]; |
163 | |
164 | hlist_for_each_entry_rcu(pdp, head, hlist_addr) { |
165 | if (pdp->af == AF_INET && |
166 | pdp->ms_addr_ip4.s_addr == ms_addr) |
167 | return pdp; |
168 | } |
169 | |
170 | return NULL; |
171 | } |
172 | |
173 | static bool gtp_check_ms_ipv4(struct sk_buff *skb, struct pdp_ctx *pctx, |
174 | unsigned int hdrlen, unsigned int role) |
175 | { |
176 | struct iphdr *iph; |
177 | |
178 | if (!pskb_may_pull(skb, len: hdrlen + sizeof(struct iphdr))) |
179 | return false; |
180 | |
181 | iph = (struct iphdr *)(skb->data + hdrlen); |
182 | |
183 | if (role == GTP_ROLE_SGSN) |
184 | return iph->daddr == pctx->ms_addr_ip4.s_addr; |
185 | else |
186 | return iph->saddr == pctx->ms_addr_ip4.s_addr; |
187 | } |
188 | |
189 | /* Check if the inner IP address in this packet is assigned to any |
190 | * existing mobile subscriber. |
191 | */ |
192 | static bool gtp_check_ms(struct sk_buff *skb, struct pdp_ctx *pctx, |
193 | unsigned int hdrlen, unsigned int role) |
194 | { |
195 | switch (ntohs(skb->protocol)) { |
196 | case ETH_P_IP: |
197 | return gtp_check_ms_ipv4(skb, pctx, hdrlen, role); |
198 | } |
199 | return false; |
200 | } |
201 | |
202 | static int gtp_rx(struct pdp_ctx *pctx, struct sk_buff *skb, |
203 | unsigned int hdrlen, unsigned int role) |
204 | { |
205 | if (!gtp_check_ms(skb, pctx, hdrlen, role)) { |
206 | netdev_dbg(pctx->dev, "No PDP ctx for this MS\n" ); |
207 | return 1; |
208 | } |
209 | |
210 | /* Get rid of the GTP + UDP headers. */ |
211 | if (iptunnel_pull_header(skb, hdr_len: hdrlen, inner_proto: skb->protocol, |
212 | xnet: !net_eq(net1: sock_net(sk: pctx->sk), net2: dev_net(dev: pctx->dev)))) { |
213 | pctx->dev->stats.rx_length_errors++; |
214 | goto err; |
215 | } |
216 | |
217 | netdev_dbg(pctx->dev, "forwarding packet from GGSN to uplink\n" ); |
218 | |
219 | /* Now that the UDP and the GTP header have been removed, set up the |
220 | * new network header. This is required by the upper layer to |
221 | * calculate the transport header. |
222 | */ |
223 | skb_reset_network_header(skb); |
224 | skb_reset_mac_header(skb); |
225 | |
226 | skb->dev = pctx->dev; |
227 | |
228 | dev_sw_netstats_rx_add(dev: pctx->dev, len: skb->len); |
229 | |
230 | __netif_rx(skb); |
231 | return 0; |
232 | |
233 | err: |
234 | pctx->dev->stats.rx_dropped++; |
235 | return -1; |
236 | } |
237 | |
238 | static struct rtable *ip4_route_output_gtp(struct flowi4 *fl4, |
239 | const struct sock *sk, |
240 | __be32 daddr, __be32 saddr) |
241 | { |
242 | memset(fl4, 0, sizeof(*fl4)); |
243 | fl4->flowi4_oif = sk->sk_bound_dev_if; |
244 | fl4->daddr = daddr; |
245 | fl4->saddr = saddr; |
246 | fl4->flowi4_tos = ip_sock_rt_tos(sk); |
247 | fl4->flowi4_scope = ip_sock_rt_scope(sk); |
248 | fl4->flowi4_proto = sk->sk_protocol; |
249 | |
250 | return ip_route_output_key(net: sock_net(sk), flp: fl4); |
251 | } |
252 | |
253 | /* GSM TS 09.60. 7.3 |
254 | * In all Path Management messages: |
255 | * - TID: is not used and shall be set to 0. |
256 | * - Flow Label is not used and shall be set to 0 |
257 | * In signalling messages: |
258 | * - number: this field is not yet used in signalling messages. |
259 | * It shall be set to 255 by the sender and shall be ignored |
260 | * by the receiver |
261 | * Returns true if the echo req was correct, false otherwise. |
262 | */ |
263 | static bool gtp0_validate_echo_hdr(struct gtp0_header *gtp0) |
264 | { |
265 | return !(gtp0->tid || (gtp0->flags ^ 0x1e) || |
266 | gtp0->number != 0xff || gtp0->flow); |
267 | } |
268 | |
269 | /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ |
270 | static void gtp0_build_echo_msg(struct gtp0_header *hdr, __u8 msg_type) |
271 | { |
272 | int len_pkt, len_hdr; |
273 | |
274 | hdr->flags = 0x1e; /* v0, GTP-non-prime. */ |
275 | hdr->type = msg_type; |
276 | /* GSM TS 09.60. 7.3 In all Path Management Flow Label and TID |
277 | * are not used and shall be set to 0. |
278 | */ |
279 | hdr->flow = 0; |
280 | hdr->tid = 0; |
281 | hdr->number = 0xff; |
282 | hdr->spare[0] = 0xff; |
283 | hdr->spare[1] = 0xff; |
284 | hdr->spare[2] = 0xff; |
285 | |
286 | len_pkt = sizeof(struct gtp0_packet); |
287 | len_hdr = sizeof(struct gtp0_header); |
288 | |
289 | if (msg_type == GTP_ECHO_RSP) |
290 | hdr->length = htons(len_pkt - len_hdr); |
291 | else |
292 | hdr->length = 0; |
293 | } |
294 | |
295 | static int gtp0_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) |
296 | { |
297 | struct gtp0_packet *gtp_pkt; |
298 | struct gtp0_header *gtp0; |
299 | struct rtable *rt; |
300 | struct flowi4 fl4; |
301 | struct iphdr *iph; |
302 | __be16 seq; |
303 | |
304 | gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); |
305 | |
306 | if (!gtp0_validate_echo_hdr(gtp0)) |
307 | return -1; |
308 | |
309 | seq = gtp0->seq; |
310 | |
311 | /* pull GTP and UDP headers */ |
312 | skb_pull_data(skb, len: sizeof(struct gtp0_header) + sizeof(struct udphdr)); |
313 | |
314 | gtp_pkt = skb_push(skb, len: sizeof(struct gtp0_packet)); |
315 | memset(gtp_pkt, 0, sizeof(struct gtp0_packet)); |
316 | |
317 | gtp0_build_echo_msg(hdr: >p_pkt->gtp0_h, GTP_ECHO_RSP); |
318 | |
319 | /* GSM TS 09.60. 7.3 The Sequence Number in a signalling response |
320 | * message shall be copied from the signalling request message |
321 | * that the GSN is replying to. |
322 | */ |
323 | gtp_pkt->gtp0_h.seq = seq; |
324 | |
325 | gtp_pkt->ie.tag = GTPIE_RECOVERY; |
326 | gtp_pkt->ie.val = gtp->restart_count; |
327 | |
328 | iph = ip_hdr(skb); |
329 | |
330 | /* find route to the sender, |
331 | * src address becomes dst address and vice versa. |
332 | */ |
333 | rt = ip4_route_output_gtp(fl4: &fl4, sk: gtp->sk0, daddr: iph->saddr, saddr: iph->daddr); |
334 | if (IS_ERR(ptr: rt)) { |
335 | netdev_dbg(gtp->dev, "no route for echo response from %pI4\n" , |
336 | &iph->saddr); |
337 | return -1; |
338 | } |
339 | |
340 | udp_tunnel_xmit_skb(rt, sk: gtp->sk0, skb, |
341 | src: fl4.saddr, dst: fl4.daddr, |
342 | tos: iph->tos, |
343 | ttl: ip4_dst_hoplimit(dst: &rt->dst), |
344 | df: 0, |
345 | htons(GTP0_PORT), htons(GTP0_PORT), |
346 | xnet: !net_eq(net1: sock_net(sk: gtp->sk1u), |
347 | net2: dev_net(dev: gtp->dev)), |
348 | nocheck: false); |
349 | return 0; |
350 | } |
351 | |
352 | static int gtp_genl_fill_echo(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, |
353 | int flags, u32 type, struct echo_info echo) |
354 | { |
355 | void *genlh; |
356 | |
357 | genlh = genlmsg_put(skb, portid: snd_portid, seq: snd_seq, family: >p_genl_family, flags, |
358 | cmd: type); |
359 | if (!genlh) |
360 | goto failure; |
361 | |
362 | if (nla_put_u32(skb, attrtype: GTPA_VERSION, value: echo.gtp_version) || |
363 | nla_put_be32(skb, attrtype: GTPA_PEER_ADDRESS, value: echo.peer_addr_ip4.s_addr) || |
364 | nla_put_be32(skb, attrtype: GTPA_MS_ADDRESS, value: echo.ms_addr_ip4.s_addr)) |
365 | goto failure; |
366 | |
367 | genlmsg_end(skb, hdr: genlh); |
368 | return 0; |
369 | |
370 | failure: |
371 | genlmsg_cancel(skb, hdr: genlh); |
372 | return -EMSGSIZE; |
373 | } |
374 | |
375 | static int gtp0_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) |
376 | { |
377 | struct gtp0_header *gtp0; |
378 | struct echo_info echo; |
379 | struct sk_buff *msg; |
380 | struct iphdr *iph; |
381 | int ret; |
382 | |
383 | gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); |
384 | |
385 | if (!gtp0_validate_echo_hdr(gtp0)) |
386 | return -1; |
387 | |
388 | iph = ip_hdr(skb); |
389 | echo.ms_addr_ip4.s_addr = iph->daddr; |
390 | echo.peer_addr_ip4.s_addr = iph->saddr; |
391 | echo.gtp_version = GTP_V0; |
392 | |
393 | msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); |
394 | if (!msg) |
395 | return -ENOMEM; |
396 | |
397 | ret = gtp_genl_fill_echo(skb: msg, snd_portid: 0, snd_seq: 0, flags: 0, type: GTP_CMD_ECHOREQ, echo); |
398 | if (ret < 0) { |
399 | nlmsg_free(skb: msg); |
400 | return ret; |
401 | } |
402 | |
403 | return genlmsg_multicast_netns(family: >p_genl_family, net: dev_net(dev: gtp->dev), |
404 | skb: msg, portid: 0, group: GTP_GENL_MCGRP, GFP_ATOMIC); |
405 | } |
406 | |
407 | /* 1 means pass up to the stack, -1 means drop and 0 means decapsulated. */ |
408 | static int gtp0_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) |
409 | { |
410 | unsigned int hdrlen = sizeof(struct udphdr) + |
411 | sizeof(struct gtp0_header); |
412 | struct gtp0_header *gtp0; |
413 | struct pdp_ctx *pctx; |
414 | |
415 | if (!pskb_may_pull(skb, len: hdrlen)) |
416 | return -1; |
417 | |
418 | gtp0 = (struct gtp0_header *)(skb->data + sizeof(struct udphdr)); |
419 | |
420 | if ((gtp0->flags >> 5) != GTP_V0) |
421 | return 1; |
422 | |
423 | /* If the sockets were created in kernel, it means that |
424 | * there is no daemon running in userspace which would |
425 | * handle echo request. |
426 | */ |
427 | if (gtp0->type == GTP_ECHO_REQ && gtp->sk_created) |
428 | return gtp0_send_echo_resp(gtp, skb); |
429 | |
430 | if (gtp0->type == GTP_ECHO_RSP && gtp->sk_created) |
431 | return gtp0_handle_echo_resp(gtp, skb); |
432 | |
433 | if (gtp0->type != GTP_TPDU) |
434 | return 1; |
435 | |
436 | pctx = gtp0_pdp_find(gtp, be64_to_cpu(gtp0->tid)); |
437 | if (!pctx) { |
438 | netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n" , skb); |
439 | return 1; |
440 | } |
441 | |
442 | return gtp_rx(pctx, skb, hdrlen, role: gtp->role); |
443 | } |
444 | |
445 | /* msg_type has to be GTP_ECHO_REQ or GTP_ECHO_RSP */ |
446 | static void gtp1u_build_echo_msg(struct gtp1_header_long *hdr, __u8 msg_type) |
447 | { |
448 | int len_pkt, len_hdr; |
449 | |
450 | /* S flag must be set to 1 */ |
451 | hdr->flags = 0x32; /* v1, GTP-non-prime. */ |
452 | hdr->type = msg_type; |
453 | /* 3GPP TS 29.281 5.1 - TEID has to be set to 0 */ |
454 | hdr->tid = 0; |
455 | |
456 | /* seq, npdu and next should be counted to the length of the GTP packet |
457 | * that's why szie of gtp1_header should be subtracted, |
458 | * not size of gtp1_header_long. |
459 | */ |
460 | |
461 | len_hdr = sizeof(struct gtp1_header); |
462 | |
463 | if (msg_type == GTP_ECHO_RSP) { |
464 | len_pkt = sizeof(struct gtp1u_packet); |
465 | hdr->length = htons(len_pkt - len_hdr); |
466 | } else { |
467 | /* GTP_ECHO_REQ does not carry GTP Information Element, |
468 | * the why gtp1_header_long is used here. |
469 | */ |
470 | len_pkt = sizeof(struct gtp1_header_long); |
471 | hdr->length = htons(len_pkt - len_hdr); |
472 | } |
473 | } |
474 | |
475 | static int gtp1u_send_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) |
476 | { |
477 | struct gtp1_header_long *gtp1u; |
478 | struct gtp1u_packet *gtp_pkt; |
479 | struct rtable *rt; |
480 | struct flowi4 fl4; |
481 | struct iphdr *iph; |
482 | |
483 | gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); |
484 | |
485 | /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, |
486 | * Error Indication and Supported Extension Headers Notification |
487 | * messages, the S flag shall be set to 1 and TEID shall be set to 0. |
488 | */ |
489 | if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) |
490 | return -1; |
491 | |
492 | /* pull GTP and UDP headers */ |
493 | skb_pull_data(skb, |
494 | len: sizeof(struct gtp1_header_long) + sizeof(struct udphdr)); |
495 | |
496 | gtp_pkt = skb_push(skb, len: sizeof(struct gtp1u_packet)); |
497 | memset(gtp_pkt, 0, sizeof(struct gtp1u_packet)); |
498 | |
499 | gtp1u_build_echo_msg(hdr: >p_pkt->gtp1u_h, GTP_ECHO_RSP); |
500 | |
501 | /* 3GPP TS 29.281 7.7.2 - The Restart Counter value in the |
502 | * Recovery information element shall not be used, i.e. it shall |
503 | * be set to zero by the sender and shall be ignored by the receiver. |
504 | * The Recovery information element is mandatory due to backwards |
505 | * compatibility reasons. |
506 | */ |
507 | gtp_pkt->ie.tag = GTPIE_RECOVERY; |
508 | gtp_pkt->ie.val = 0; |
509 | |
510 | iph = ip_hdr(skb); |
511 | |
512 | /* find route to the sender, |
513 | * src address becomes dst address and vice versa. |
514 | */ |
515 | rt = ip4_route_output_gtp(fl4: &fl4, sk: gtp->sk1u, daddr: iph->saddr, saddr: iph->daddr); |
516 | if (IS_ERR(ptr: rt)) { |
517 | netdev_dbg(gtp->dev, "no route for echo response from %pI4\n" , |
518 | &iph->saddr); |
519 | return -1; |
520 | } |
521 | |
522 | udp_tunnel_xmit_skb(rt, sk: gtp->sk1u, skb, |
523 | src: fl4.saddr, dst: fl4.daddr, |
524 | tos: iph->tos, |
525 | ttl: ip4_dst_hoplimit(dst: &rt->dst), |
526 | df: 0, |
527 | htons(GTP1U_PORT), htons(GTP1U_PORT), |
528 | xnet: !net_eq(net1: sock_net(sk: gtp->sk1u), |
529 | net2: dev_net(dev: gtp->dev)), |
530 | nocheck: false); |
531 | return 0; |
532 | } |
533 | |
534 | static int gtp1u_handle_echo_resp(struct gtp_dev *gtp, struct sk_buff *skb) |
535 | { |
536 | struct gtp1_header_long *gtp1u; |
537 | struct echo_info echo; |
538 | struct sk_buff *msg; |
539 | struct iphdr *iph; |
540 | int ret; |
541 | |
542 | gtp1u = (struct gtp1_header_long *)(skb->data + sizeof(struct udphdr)); |
543 | |
544 | /* 3GPP TS 29.281 5.1 - For the Echo Request, Echo Response, |
545 | * Error Indication and Supported Extension Headers Notification |
546 | * messages, the S flag shall be set to 1 and TEID shall be set to 0. |
547 | */ |
548 | if (!(gtp1u->flags & GTP1_F_SEQ) || gtp1u->tid) |
549 | return -1; |
550 | |
551 | iph = ip_hdr(skb); |
552 | echo.ms_addr_ip4.s_addr = iph->daddr; |
553 | echo.peer_addr_ip4.s_addr = iph->saddr; |
554 | echo.gtp_version = GTP_V1; |
555 | |
556 | msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); |
557 | if (!msg) |
558 | return -ENOMEM; |
559 | |
560 | ret = gtp_genl_fill_echo(skb: msg, snd_portid: 0, snd_seq: 0, flags: 0, type: GTP_CMD_ECHOREQ, echo); |
561 | if (ret < 0) { |
562 | nlmsg_free(skb: msg); |
563 | return ret; |
564 | } |
565 | |
566 | return genlmsg_multicast_netns(family: >p_genl_family, net: dev_net(dev: gtp->dev), |
567 | skb: msg, portid: 0, group: GTP_GENL_MCGRP, GFP_ATOMIC); |
568 | } |
569 | |
570 | static int gtp1u_udp_encap_recv(struct gtp_dev *gtp, struct sk_buff *skb) |
571 | { |
572 | unsigned int hdrlen = sizeof(struct udphdr) + |
573 | sizeof(struct gtp1_header); |
574 | struct gtp1_header *gtp1; |
575 | struct pdp_ctx *pctx; |
576 | |
577 | if (!pskb_may_pull(skb, len: hdrlen)) |
578 | return -1; |
579 | |
580 | gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); |
581 | |
582 | if ((gtp1->flags >> 5) != GTP_V1) |
583 | return 1; |
584 | |
585 | /* If the sockets were created in kernel, it means that |
586 | * there is no daemon running in userspace which would |
587 | * handle echo request. |
588 | */ |
589 | if (gtp1->type == GTP_ECHO_REQ && gtp->sk_created) |
590 | return gtp1u_send_echo_resp(gtp, skb); |
591 | |
592 | if (gtp1->type == GTP_ECHO_RSP && gtp->sk_created) |
593 | return gtp1u_handle_echo_resp(gtp, skb); |
594 | |
595 | if (gtp1->type != GTP_TPDU) |
596 | return 1; |
597 | |
598 | /* From 29.060: "This field shall be present if and only if any one or |
599 | * more of the S, PN and E flags are set.". |
600 | * |
601 | * If any of the bit is set, then the remaining ones also have to be |
602 | * set. |
603 | */ |
604 | if (gtp1->flags & GTP1_F_MASK) |
605 | hdrlen += 4; |
606 | |
607 | /* Make sure the header is larger enough, including extensions. */ |
608 | if (!pskb_may_pull(skb, len: hdrlen)) |
609 | return -1; |
610 | |
611 | gtp1 = (struct gtp1_header *)(skb->data + sizeof(struct udphdr)); |
612 | |
613 | pctx = gtp1_pdp_find(gtp, ntohl(gtp1->tid)); |
614 | if (!pctx) { |
615 | netdev_dbg(gtp->dev, "No PDP ctx to decap skb=%p\n" , skb); |
616 | return 1; |
617 | } |
618 | |
619 | return gtp_rx(pctx, skb, hdrlen, role: gtp->role); |
620 | } |
621 | |
622 | static void __gtp_encap_destroy(struct sock *sk) |
623 | { |
624 | struct gtp_dev *gtp; |
625 | |
626 | lock_sock(sk); |
627 | gtp = sk->sk_user_data; |
628 | if (gtp) { |
629 | if (gtp->sk0 == sk) |
630 | gtp->sk0 = NULL; |
631 | else |
632 | gtp->sk1u = NULL; |
633 | WRITE_ONCE(udp_sk(sk)->encap_type, 0); |
634 | rcu_assign_sk_user_data(sk, NULL); |
635 | release_sock(sk); |
636 | sock_put(sk); |
637 | return; |
638 | } |
639 | release_sock(sk); |
640 | } |
641 | |
642 | static void gtp_encap_destroy(struct sock *sk) |
643 | { |
644 | rtnl_lock(); |
645 | __gtp_encap_destroy(sk); |
646 | rtnl_unlock(); |
647 | } |
648 | |
649 | static void gtp_encap_disable_sock(struct sock *sk) |
650 | { |
651 | if (!sk) |
652 | return; |
653 | |
654 | __gtp_encap_destroy(sk); |
655 | } |
656 | |
657 | static void gtp_encap_disable(struct gtp_dev *gtp) |
658 | { |
659 | if (gtp->sk_created) { |
660 | udp_tunnel_sock_release(sock: gtp->sk0->sk_socket); |
661 | udp_tunnel_sock_release(sock: gtp->sk1u->sk_socket); |
662 | gtp->sk_created = false; |
663 | gtp->sk0 = NULL; |
664 | gtp->sk1u = NULL; |
665 | } else { |
666 | gtp_encap_disable_sock(sk: gtp->sk0); |
667 | gtp_encap_disable_sock(sk: gtp->sk1u); |
668 | } |
669 | } |
670 | |
671 | /* UDP encapsulation receive handler. See net/ipv4/udp.c. |
672 | * Return codes: 0: success, <0: error, >0: pass up to userspace UDP socket. |
673 | */ |
674 | static int gtp_encap_recv(struct sock *sk, struct sk_buff *skb) |
675 | { |
676 | struct gtp_dev *gtp; |
677 | int ret = 0; |
678 | |
679 | gtp = rcu_dereference_sk_user_data(sk); |
680 | if (!gtp) |
681 | return 1; |
682 | |
683 | netdev_dbg(gtp->dev, "encap_recv sk=%p\n" , sk); |
684 | |
685 | switch (READ_ONCE(udp_sk(sk)->encap_type)) { |
686 | case UDP_ENCAP_GTP0: |
687 | netdev_dbg(gtp->dev, "received GTP0 packet\n" ); |
688 | ret = gtp0_udp_encap_recv(gtp, skb); |
689 | break; |
690 | case UDP_ENCAP_GTP1U: |
691 | netdev_dbg(gtp->dev, "received GTP1U packet\n" ); |
692 | ret = gtp1u_udp_encap_recv(gtp, skb); |
693 | break; |
694 | default: |
695 | ret = -1; /* Shouldn't happen. */ |
696 | } |
697 | |
698 | switch (ret) { |
699 | case 1: |
700 | netdev_dbg(gtp->dev, "pass up to the process\n" ); |
701 | break; |
702 | case 0: |
703 | break; |
704 | case -1: |
705 | netdev_dbg(gtp->dev, "GTP packet has been dropped\n" ); |
706 | kfree_skb(skb); |
707 | ret = 0; |
708 | break; |
709 | } |
710 | |
711 | return ret; |
712 | } |
713 | |
714 | static void gtp_dev_uninit(struct net_device *dev) |
715 | { |
716 | struct gtp_dev *gtp = netdev_priv(dev); |
717 | |
718 | gtp_encap_disable(gtp); |
719 | } |
720 | |
721 | static inline void (struct sk_buff *skb, struct pdp_ctx *pctx) |
722 | { |
723 | int payload_len = skb->len; |
724 | struct gtp0_header *gtp0; |
725 | |
726 | gtp0 = skb_push(skb, len: sizeof(*gtp0)); |
727 | |
728 | gtp0->flags = 0x1e; /* v0, GTP-non-prime. */ |
729 | gtp0->type = GTP_TPDU; |
730 | gtp0->length = htons(payload_len); |
731 | gtp0->seq = htons((atomic_inc_return(&pctx->tx_seq) - 1) % 0xffff); |
732 | gtp0->flow = htons(pctx->u.v0.flow); |
733 | gtp0->number = 0xff; |
734 | gtp0->spare[0] = gtp0->spare[1] = gtp0->spare[2] = 0xff; |
735 | gtp0->tid = cpu_to_be64(pctx->u.v0.tid); |
736 | } |
737 | |
738 | static inline void (struct sk_buff *skb, struct pdp_ctx *pctx) |
739 | { |
740 | int payload_len = skb->len; |
741 | struct gtp1_header *gtp1; |
742 | |
743 | gtp1 = skb_push(skb, len: sizeof(*gtp1)); |
744 | |
745 | /* Bits 8 7 6 5 4 3 2 1 |
746 | * +--+--+--+--+--+--+--+--+ |
747 | * |version |PT| 0| E| S|PN| |
748 | * +--+--+--+--+--+--+--+--+ |
749 | * 0 0 1 1 1 0 0 0 |
750 | */ |
751 | gtp1->flags = 0x30; /* v1, GTP-non-prime. */ |
752 | gtp1->type = GTP_TPDU; |
753 | gtp1->length = htons(payload_len); |
754 | gtp1->tid = htonl(pctx->u.v1.o_tei); |
755 | |
756 | /* TODO: Support for extension header, sequence number and N-PDU. |
757 | * Update the length field if any of them is available. |
758 | */ |
759 | } |
760 | |
761 | struct gtp_pktinfo { |
762 | struct sock *sk; |
763 | struct iphdr *iph; |
764 | struct flowi4 fl4; |
765 | struct rtable *rt; |
766 | struct pdp_ctx *pctx; |
767 | struct net_device *dev; |
768 | __be16 gtph_port; |
769 | }; |
770 | |
771 | static void (struct sk_buff *skb, struct gtp_pktinfo *pktinfo) |
772 | { |
773 | switch (pktinfo->pctx->gtp_version) { |
774 | case GTP_V0: |
775 | pktinfo->gtph_port = htons(GTP0_PORT); |
776 | gtp0_push_header(skb, pctx: pktinfo->pctx); |
777 | break; |
778 | case GTP_V1: |
779 | pktinfo->gtph_port = htons(GTP1U_PORT); |
780 | gtp1_push_header(skb, pctx: pktinfo->pctx); |
781 | break; |
782 | } |
783 | } |
784 | |
785 | static inline void gtp_set_pktinfo_ipv4(struct gtp_pktinfo *pktinfo, |
786 | struct sock *sk, struct iphdr *iph, |
787 | struct pdp_ctx *pctx, struct rtable *rt, |
788 | struct flowi4 *fl4, |
789 | struct net_device *dev) |
790 | { |
791 | pktinfo->sk = sk; |
792 | pktinfo->iph = iph; |
793 | pktinfo->pctx = pctx; |
794 | pktinfo->rt = rt; |
795 | pktinfo->fl4 = *fl4; |
796 | pktinfo->dev = dev; |
797 | } |
798 | |
799 | static int gtp_build_skb_ip4(struct sk_buff *skb, struct net_device *dev, |
800 | struct gtp_pktinfo *pktinfo) |
801 | { |
802 | struct gtp_dev *gtp = netdev_priv(dev); |
803 | struct pdp_ctx *pctx; |
804 | struct rtable *rt; |
805 | struct flowi4 fl4; |
806 | struct iphdr *iph; |
807 | __be16 df; |
808 | int mtu; |
809 | |
810 | /* Read the IP destination address and resolve the PDP context. |
811 | * Prepend PDP header with TEI/TID from PDP ctx. |
812 | */ |
813 | iph = ip_hdr(skb); |
814 | if (gtp->role == GTP_ROLE_SGSN) |
815 | pctx = ipv4_pdp_find(gtp, ms_addr: iph->saddr); |
816 | else |
817 | pctx = ipv4_pdp_find(gtp, ms_addr: iph->daddr); |
818 | |
819 | if (!pctx) { |
820 | netdev_dbg(dev, "no PDP ctx found for %pI4, skip\n" , |
821 | &iph->daddr); |
822 | return -ENOENT; |
823 | } |
824 | netdev_dbg(dev, "found PDP context %p\n" , pctx); |
825 | |
826 | rt = ip4_route_output_gtp(fl4: &fl4, sk: pctx->sk, daddr: pctx->peer_addr_ip4.s_addr, |
827 | inet_sk(pctx->sk)->inet_saddr); |
828 | if (IS_ERR(ptr: rt)) { |
829 | netdev_dbg(dev, "no route to SSGN %pI4\n" , |
830 | &pctx->peer_addr_ip4.s_addr); |
831 | dev->stats.tx_carrier_errors++; |
832 | goto err; |
833 | } |
834 | |
835 | if (rt->dst.dev == dev) { |
836 | netdev_dbg(dev, "circular route to SSGN %pI4\n" , |
837 | &pctx->peer_addr_ip4.s_addr); |
838 | dev->stats.collisions++; |
839 | goto err_rt; |
840 | } |
841 | |
842 | /* This is similar to tnl_update_pmtu(). */ |
843 | df = iph->frag_off; |
844 | if (df) { |
845 | mtu = dst_mtu(dst: &rt->dst) - dev->hard_header_len - |
846 | sizeof(struct iphdr) - sizeof(struct udphdr); |
847 | switch (pctx->gtp_version) { |
848 | case GTP_V0: |
849 | mtu -= sizeof(struct gtp0_header); |
850 | break; |
851 | case GTP_V1: |
852 | mtu -= sizeof(struct gtp1_header); |
853 | break; |
854 | } |
855 | } else { |
856 | mtu = dst_mtu(dst: &rt->dst); |
857 | } |
858 | |
859 | skb_dst_update_pmtu_no_confirm(skb, mtu); |
860 | |
861 | if (iph->frag_off & htons(IP_DF) && |
862 | ((!skb_is_gso(skb) && skb->len > mtu) || |
863 | (skb_is_gso(skb) && !skb_gso_validate_network_len(skb, mtu)))) { |
864 | netdev_dbg(dev, "packet too big, fragmentation needed\n" ); |
865 | icmp_ndo_send(skb_in: skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED, |
866 | htonl(mtu)); |
867 | goto err_rt; |
868 | } |
869 | |
870 | gtp_set_pktinfo_ipv4(pktinfo, sk: pctx->sk, iph, pctx, rt, fl4: &fl4, dev); |
871 | gtp_push_header(skb, pktinfo); |
872 | |
873 | return 0; |
874 | err_rt: |
875 | ip_rt_put(rt); |
876 | err: |
877 | return -EBADMSG; |
878 | } |
879 | |
880 | static netdev_tx_t gtp_dev_xmit(struct sk_buff *skb, struct net_device *dev) |
881 | { |
882 | unsigned int proto = ntohs(skb->protocol); |
883 | struct gtp_pktinfo pktinfo; |
884 | int err; |
885 | |
886 | /* Ensure there is sufficient headroom. */ |
887 | if (skb_cow_head(skb, headroom: dev->needed_headroom)) |
888 | goto tx_err; |
889 | |
890 | skb_reset_inner_headers(skb); |
891 | |
892 | /* PDP context lookups in gtp_build_skb_*() need rcu read-side lock. */ |
893 | rcu_read_lock(); |
894 | switch (proto) { |
895 | case ETH_P_IP: |
896 | err = gtp_build_skb_ip4(skb, dev, pktinfo: &pktinfo); |
897 | break; |
898 | default: |
899 | err = -EOPNOTSUPP; |
900 | break; |
901 | } |
902 | rcu_read_unlock(); |
903 | |
904 | if (err < 0) |
905 | goto tx_err; |
906 | |
907 | switch (proto) { |
908 | case ETH_P_IP: |
909 | netdev_dbg(pktinfo.dev, "gtp -> IP src: %pI4 dst: %pI4\n" , |
910 | &pktinfo.iph->saddr, &pktinfo.iph->daddr); |
911 | udp_tunnel_xmit_skb(rt: pktinfo.rt, sk: pktinfo.sk, skb, |
912 | src: pktinfo.fl4.saddr, dst: pktinfo.fl4.daddr, |
913 | tos: pktinfo.iph->tos, |
914 | ttl: ip4_dst_hoplimit(dst: &pktinfo.rt->dst), |
915 | df: 0, |
916 | src_port: pktinfo.gtph_port, dst_port: pktinfo.gtph_port, |
917 | xnet: !net_eq(net1: sock_net(sk: pktinfo.pctx->sk), |
918 | net2: dev_net(dev)), |
919 | nocheck: false); |
920 | break; |
921 | } |
922 | |
923 | return NETDEV_TX_OK; |
924 | tx_err: |
925 | dev->stats.tx_errors++; |
926 | dev_kfree_skb(skb); |
927 | return NETDEV_TX_OK; |
928 | } |
929 | |
930 | static const struct net_device_ops gtp_netdev_ops = { |
931 | .ndo_uninit = gtp_dev_uninit, |
932 | .ndo_start_xmit = gtp_dev_xmit, |
933 | }; |
934 | |
935 | static const struct device_type gtp_type = { |
936 | .name = "gtp" , |
937 | }; |
938 | |
939 | static void gtp_link_setup(struct net_device *dev) |
940 | { |
941 | unsigned int = sizeof(struct iphdr) + |
942 | sizeof(struct udphdr) + |
943 | sizeof(struct gtp0_header); |
944 | struct gtp_dev *gtp = netdev_priv(dev); |
945 | |
946 | dev->netdev_ops = >p_netdev_ops; |
947 | dev->needs_free_netdev = true; |
948 | SET_NETDEV_DEVTYPE(dev, >p_type); |
949 | |
950 | dev->hard_header_len = 0; |
951 | dev->addr_len = 0; |
952 | dev->mtu = ETH_DATA_LEN - max_gtp_header_len; |
953 | |
954 | /* Zero header length. */ |
955 | dev->type = ARPHRD_NONE; |
956 | dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; |
957 | |
958 | dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS; |
959 | dev->priv_flags |= IFF_NO_QUEUE; |
960 | dev->features |= NETIF_F_LLTX; |
961 | netif_keep_dst(dev); |
962 | |
963 | dev->needed_headroom = LL_MAX_HEADER + max_gtp_header_len; |
964 | gtp->dev = dev; |
965 | } |
966 | |
967 | static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize); |
968 | static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]); |
969 | |
970 | static void gtp_destructor(struct net_device *dev) |
971 | { |
972 | struct gtp_dev *gtp = netdev_priv(dev); |
973 | |
974 | kfree(objp: gtp->addr_hash); |
975 | kfree(objp: gtp->tid_hash); |
976 | } |
977 | |
978 | static struct sock *gtp_create_sock(int type, struct gtp_dev *gtp) |
979 | { |
980 | struct udp_tunnel_sock_cfg tuncfg = {}; |
981 | struct udp_port_cfg udp_conf = { |
982 | .local_ip.s_addr = htonl(INADDR_ANY), |
983 | .family = AF_INET, |
984 | }; |
985 | struct net *net = gtp->net; |
986 | struct socket *sock; |
987 | int err; |
988 | |
989 | if (type == UDP_ENCAP_GTP0) |
990 | udp_conf.local_udp_port = htons(GTP0_PORT); |
991 | else if (type == UDP_ENCAP_GTP1U) |
992 | udp_conf.local_udp_port = htons(GTP1U_PORT); |
993 | else |
994 | return ERR_PTR(error: -EINVAL); |
995 | |
996 | err = udp_sock_create(net, cfg: &udp_conf, sockp: &sock); |
997 | if (err) |
998 | return ERR_PTR(error: err); |
999 | |
1000 | tuncfg.sk_user_data = gtp; |
1001 | tuncfg.encap_type = type; |
1002 | tuncfg.encap_rcv = gtp_encap_recv; |
1003 | tuncfg.encap_destroy = NULL; |
1004 | |
1005 | setup_udp_tunnel_sock(net, sock, sock_cfg: &tuncfg); |
1006 | |
1007 | return sock->sk; |
1008 | } |
1009 | |
1010 | static int gtp_create_sockets(struct gtp_dev *gtp, struct nlattr *data[]) |
1011 | { |
1012 | struct sock *sk1u = NULL; |
1013 | struct sock *sk0 = NULL; |
1014 | |
1015 | sk0 = gtp_create_sock(UDP_ENCAP_GTP0, gtp); |
1016 | if (IS_ERR(ptr: sk0)) |
1017 | return PTR_ERR(ptr: sk0); |
1018 | |
1019 | sk1u = gtp_create_sock(UDP_ENCAP_GTP1U, gtp); |
1020 | if (IS_ERR(ptr: sk1u)) { |
1021 | udp_tunnel_sock_release(sock: sk0->sk_socket); |
1022 | return PTR_ERR(ptr: sk1u); |
1023 | } |
1024 | |
1025 | gtp->sk_created = true; |
1026 | gtp->sk0 = sk0; |
1027 | gtp->sk1u = sk1u; |
1028 | |
1029 | return 0; |
1030 | } |
1031 | |
1032 | static int gtp_newlink(struct net *src_net, struct net_device *dev, |
1033 | struct nlattr *tb[], struct nlattr *data[], |
1034 | struct netlink_ext_ack *extack) |
1035 | { |
1036 | unsigned int role = GTP_ROLE_GGSN; |
1037 | struct gtp_dev *gtp; |
1038 | struct gtp_net *gn; |
1039 | int hashsize, err; |
1040 | |
1041 | gtp = netdev_priv(dev); |
1042 | |
1043 | if (!data[IFLA_GTP_PDP_HASHSIZE]) { |
1044 | hashsize = 1024; |
1045 | } else { |
1046 | hashsize = nla_get_u32(nla: data[IFLA_GTP_PDP_HASHSIZE]); |
1047 | if (!hashsize) |
1048 | hashsize = 1024; |
1049 | } |
1050 | |
1051 | if (data[IFLA_GTP_ROLE]) { |
1052 | role = nla_get_u32(nla: data[IFLA_GTP_ROLE]); |
1053 | if (role > GTP_ROLE_SGSN) |
1054 | return -EINVAL; |
1055 | } |
1056 | gtp->role = role; |
1057 | |
1058 | if (!data[IFLA_GTP_RESTART_COUNT]) |
1059 | gtp->restart_count = 0; |
1060 | else |
1061 | gtp->restart_count = nla_get_u8(nla: data[IFLA_GTP_RESTART_COUNT]); |
1062 | |
1063 | gtp->net = src_net; |
1064 | |
1065 | err = gtp_hashtable_new(gtp, hsize: hashsize); |
1066 | if (err < 0) |
1067 | return err; |
1068 | |
1069 | if (data[IFLA_GTP_CREATE_SOCKETS]) |
1070 | err = gtp_create_sockets(gtp, data); |
1071 | else |
1072 | err = gtp_encap_enable(gtp, data); |
1073 | if (err < 0) |
1074 | goto out_hashtable; |
1075 | |
1076 | err = register_netdevice(dev); |
1077 | if (err < 0) { |
1078 | netdev_dbg(dev, "failed to register new netdev %d\n" , err); |
1079 | goto out_encap; |
1080 | } |
1081 | |
1082 | gn = net_generic(net: dev_net(dev), id: gtp_net_id); |
1083 | list_add_rcu(new: >p->list, head: &gn->gtp_dev_list); |
1084 | dev->priv_destructor = gtp_destructor; |
1085 | |
1086 | netdev_dbg(dev, "registered new GTP interface\n" ); |
1087 | |
1088 | return 0; |
1089 | |
1090 | out_encap: |
1091 | gtp_encap_disable(gtp); |
1092 | out_hashtable: |
1093 | kfree(objp: gtp->addr_hash); |
1094 | kfree(objp: gtp->tid_hash); |
1095 | return err; |
1096 | } |
1097 | |
1098 | static void gtp_dellink(struct net_device *dev, struct list_head *head) |
1099 | { |
1100 | struct gtp_dev *gtp = netdev_priv(dev); |
1101 | struct pdp_ctx *pctx; |
1102 | int i; |
1103 | |
1104 | for (i = 0; i < gtp->hash_size; i++) |
1105 | hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], hlist_tid) |
1106 | pdp_context_delete(pctx); |
1107 | |
1108 | list_del_rcu(entry: >p->list); |
1109 | unregister_netdevice_queue(dev, head); |
1110 | } |
1111 | |
1112 | static const struct nla_policy gtp_policy[IFLA_GTP_MAX + 1] = { |
1113 | [IFLA_GTP_FD0] = { .type = NLA_U32 }, |
1114 | [IFLA_GTP_FD1] = { .type = NLA_U32 }, |
1115 | [IFLA_GTP_PDP_HASHSIZE] = { .type = NLA_U32 }, |
1116 | [IFLA_GTP_ROLE] = { .type = NLA_U32 }, |
1117 | [IFLA_GTP_CREATE_SOCKETS] = { .type = NLA_U8 }, |
1118 | [IFLA_GTP_RESTART_COUNT] = { .type = NLA_U8 }, |
1119 | }; |
1120 | |
1121 | static int gtp_validate(struct nlattr *tb[], struct nlattr *data[], |
1122 | struct netlink_ext_ack *extack) |
1123 | { |
1124 | if (!data) |
1125 | return -EINVAL; |
1126 | |
1127 | return 0; |
1128 | } |
1129 | |
1130 | static size_t gtp_get_size(const struct net_device *dev) |
1131 | { |
1132 | return nla_total_size(payload: sizeof(__u32)) + /* IFLA_GTP_PDP_HASHSIZE */ |
1133 | nla_total_size(payload: sizeof(__u32)) + /* IFLA_GTP_ROLE */ |
1134 | nla_total_size(payload: sizeof(__u8)); /* IFLA_GTP_RESTART_COUNT */ |
1135 | } |
1136 | |
1137 | static int gtp_fill_info(struct sk_buff *skb, const struct net_device *dev) |
1138 | { |
1139 | struct gtp_dev *gtp = netdev_priv(dev); |
1140 | |
1141 | if (nla_put_u32(skb, attrtype: IFLA_GTP_PDP_HASHSIZE, value: gtp->hash_size)) |
1142 | goto nla_put_failure; |
1143 | if (nla_put_u32(skb, attrtype: IFLA_GTP_ROLE, value: gtp->role)) |
1144 | goto nla_put_failure; |
1145 | if (nla_put_u8(skb, attrtype: IFLA_GTP_RESTART_COUNT, value: gtp->restart_count)) |
1146 | goto nla_put_failure; |
1147 | |
1148 | return 0; |
1149 | |
1150 | nla_put_failure: |
1151 | return -EMSGSIZE; |
1152 | } |
1153 | |
1154 | static struct rtnl_link_ops gtp_link_ops __read_mostly = { |
1155 | .kind = "gtp" , |
1156 | .maxtype = IFLA_GTP_MAX, |
1157 | .policy = gtp_policy, |
1158 | .priv_size = sizeof(struct gtp_dev), |
1159 | .setup = gtp_link_setup, |
1160 | .validate = gtp_validate, |
1161 | .newlink = gtp_newlink, |
1162 | .dellink = gtp_dellink, |
1163 | .get_size = gtp_get_size, |
1164 | .fill_info = gtp_fill_info, |
1165 | }; |
1166 | |
1167 | static int gtp_hashtable_new(struct gtp_dev *gtp, int hsize) |
1168 | { |
1169 | int i; |
1170 | |
1171 | gtp->addr_hash = kmalloc_array(n: hsize, size: sizeof(struct hlist_head), |
1172 | GFP_KERNEL | __GFP_NOWARN); |
1173 | if (gtp->addr_hash == NULL) |
1174 | return -ENOMEM; |
1175 | |
1176 | gtp->tid_hash = kmalloc_array(n: hsize, size: sizeof(struct hlist_head), |
1177 | GFP_KERNEL | __GFP_NOWARN); |
1178 | if (gtp->tid_hash == NULL) |
1179 | goto err1; |
1180 | |
1181 | gtp->hash_size = hsize; |
1182 | |
1183 | for (i = 0; i < hsize; i++) { |
1184 | INIT_HLIST_HEAD(>p->addr_hash[i]); |
1185 | INIT_HLIST_HEAD(>p->tid_hash[i]); |
1186 | } |
1187 | return 0; |
1188 | err1: |
1189 | kfree(objp: gtp->addr_hash); |
1190 | return -ENOMEM; |
1191 | } |
1192 | |
1193 | static struct sock *gtp_encap_enable_socket(int fd, int type, |
1194 | struct gtp_dev *gtp) |
1195 | { |
1196 | struct udp_tunnel_sock_cfg tuncfg = {NULL}; |
1197 | struct socket *sock; |
1198 | struct sock *sk; |
1199 | int err; |
1200 | |
1201 | pr_debug("enable gtp on %d, %d\n" , fd, type); |
1202 | |
1203 | sock = sockfd_lookup(fd, err: &err); |
1204 | if (!sock) { |
1205 | pr_debug("gtp socket fd=%d not found\n" , fd); |
1206 | return NULL; |
1207 | } |
1208 | |
1209 | sk = sock->sk; |
1210 | if (sk->sk_protocol != IPPROTO_UDP || |
1211 | sk->sk_type != SOCK_DGRAM || |
1212 | (sk->sk_family != AF_INET && sk->sk_family != AF_INET6)) { |
1213 | pr_debug("socket fd=%d not UDP\n" , fd); |
1214 | sk = ERR_PTR(error: -EINVAL); |
1215 | goto out_sock; |
1216 | } |
1217 | |
1218 | lock_sock(sk); |
1219 | if (sk->sk_user_data) { |
1220 | sk = ERR_PTR(error: -EBUSY); |
1221 | goto out_rel_sock; |
1222 | } |
1223 | |
1224 | sock_hold(sk); |
1225 | |
1226 | tuncfg.sk_user_data = gtp; |
1227 | tuncfg.encap_type = type; |
1228 | tuncfg.encap_rcv = gtp_encap_recv; |
1229 | tuncfg.encap_destroy = gtp_encap_destroy; |
1230 | |
1231 | setup_udp_tunnel_sock(net: sock_net(sk: sock->sk), sock, sock_cfg: &tuncfg); |
1232 | |
1233 | out_rel_sock: |
1234 | release_sock(sk: sock->sk); |
1235 | out_sock: |
1236 | sockfd_put(sock); |
1237 | return sk; |
1238 | } |
1239 | |
1240 | static int gtp_encap_enable(struct gtp_dev *gtp, struct nlattr *data[]) |
1241 | { |
1242 | struct sock *sk1u = NULL; |
1243 | struct sock *sk0 = NULL; |
1244 | |
1245 | if (!data[IFLA_GTP_FD0] && !data[IFLA_GTP_FD1]) |
1246 | return -EINVAL; |
1247 | |
1248 | if (data[IFLA_GTP_FD0]) { |
1249 | u32 fd0 = nla_get_u32(nla: data[IFLA_GTP_FD0]); |
1250 | |
1251 | sk0 = gtp_encap_enable_socket(fd: fd0, UDP_ENCAP_GTP0, gtp); |
1252 | if (IS_ERR(ptr: sk0)) |
1253 | return PTR_ERR(ptr: sk0); |
1254 | } |
1255 | |
1256 | if (data[IFLA_GTP_FD1]) { |
1257 | u32 fd1 = nla_get_u32(nla: data[IFLA_GTP_FD1]); |
1258 | |
1259 | sk1u = gtp_encap_enable_socket(fd: fd1, UDP_ENCAP_GTP1U, gtp); |
1260 | if (IS_ERR(ptr: sk1u)) { |
1261 | gtp_encap_disable_sock(sk: sk0); |
1262 | return PTR_ERR(ptr: sk1u); |
1263 | } |
1264 | } |
1265 | |
1266 | gtp->sk0 = sk0; |
1267 | gtp->sk1u = sk1u; |
1268 | |
1269 | return 0; |
1270 | } |
1271 | |
1272 | static struct gtp_dev *gtp_find_dev(struct net *src_net, struct nlattr *nla[]) |
1273 | { |
1274 | struct gtp_dev *gtp = NULL; |
1275 | struct net_device *dev; |
1276 | struct net *net; |
1277 | |
1278 | /* Examine the link attributes and figure out which network namespace |
1279 | * we are talking about. |
1280 | */ |
1281 | if (nla[GTPA_NET_NS_FD]) |
1282 | net = get_net_ns_by_fd(fd: nla_get_u32(nla: nla[GTPA_NET_NS_FD])); |
1283 | else |
1284 | net = get_net(net: src_net); |
1285 | |
1286 | if (IS_ERR(ptr: net)) |
1287 | return NULL; |
1288 | |
1289 | /* Check if there's an existing gtpX device to configure */ |
1290 | dev = dev_get_by_index_rcu(net, ifindex: nla_get_u32(nla: nla[GTPA_LINK])); |
1291 | if (dev && dev->netdev_ops == >p_netdev_ops) |
1292 | gtp = netdev_priv(dev); |
1293 | |
1294 | put_net(net); |
1295 | return gtp; |
1296 | } |
1297 | |
1298 | static void ipv4_pdp_fill(struct pdp_ctx *pctx, struct genl_info *info) |
1299 | { |
1300 | pctx->gtp_version = nla_get_u32(nla: info->attrs[GTPA_VERSION]); |
1301 | pctx->af = AF_INET; |
1302 | pctx->peer_addr_ip4.s_addr = |
1303 | nla_get_be32(nla: info->attrs[GTPA_PEER_ADDRESS]); |
1304 | pctx->ms_addr_ip4.s_addr = |
1305 | nla_get_be32(nla: info->attrs[GTPA_MS_ADDRESS]); |
1306 | |
1307 | switch (pctx->gtp_version) { |
1308 | case GTP_V0: |
1309 | /* According to TS 09.60, sections 7.5.1 and 7.5.2, the flow |
1310 | * label needs to be the same for uplink and downlink packets, |
1311 | * so let's annotate this. |
1312 | */ |
1313 | pctx->u.v0.tid = nla_get_u64(nla: info->attrs[GTPA_TID]); |
1314 | pctx->u.v0.flow = nla_get_u16(nla: info->attrs[GTPA_FLOW]); |
1315 | break; |
1316 | case GTP_V1: |
1317 | pctx->u.v1.i_tei = nla_get_u32(nla: info->attrs[GTPA_I_TEI]); |
1318 | pctx->u.v1.o_tei = nla_get_u32(nla: info->attrs[GTPA_O_TEI]); |
1319 | break; |
1320 | default: |
1321 | break; |
1322 | } |
1323 | } |
1324 | |
1325 | static struct pdp_ctx *gtp_pdp_add(struct gtp_dev *gtp, struct sock *sk, |
1326 | struct genl_info *info) |
1327 | { |
1328 | struct pdp_ctx *pctx, *pctx_tid = NULL; |
1329 | struct net_device *dev = gtp->dev; |
1330 | u32 hash_ms, hash_tid = 0; |
1331 | unsigned int version; |
1332 | bool found = false; |
1333 | __be32 ms_addr; |
1334 | |
1335 | ms_addr = nla_get_be32(nla: info->attrs[GTPA_MS_ADDRESS]); |
1336 | hash_ms = ipv4_hashfn(ip: ms_addr) % gtp->hash_size; |
1337 | version = nla_get_u32(nla: info->attrs[GTPA_VERSION]); |
1338 | |
1339 | pctx = ipv4_pdp_find(gtp, ms_addr); |
1340 | if (pctx) |
1341 | found = true; |
1342 | if (version == GTP_V0) |
1343 | pctx_tid = gtp0_pdp_find(gtp, |
1344 | tid: nla_get_u64(nla: info->attrs[GTPA_TID])); |
1345 | else if (version == GTP_V1) |
1346 | pctx_tid = gtp1_pdp_find(gtp, |
1347 | tid: nla_get_u32(nla: info->attrs[GTPA_I_TEI])); |
1348 | if (pctx_tid) |
1349 | found = true; |
1350 | |
1351 | if (found) { |
1352 | if (info->nlhdr->nlmsg_flags & NLM_F_EXCL) |
1353 | return ERR_PTR(error: -EEXIST); |
1354 | if (info->nlhdr->nlmsg_flags & NLM_F_REPLACE) |
1355 | return ERR_PTR(error: -EOPNOTSUPP); |
1356 | |
1357 | if (pctx && pctx_tid) |
1358 | return ERR_PTR(error: -EEXIST); |
1359 | if (!pctx) |
1360 | pctx = pctx_tid; |
1361 | |
1362 | ipv4_pdp_fill(pctx, info); |
1363 | |
1364 | if (pctx->gtp_version == GTP_V0) |
1365 | netdev_dbg(dev, "GTPv0-U: update tunnel id = %llx (pdp %p)\n" , |
1366 | pctx->u.v0.tid, pctx); |
1367 | else if (pctx->gtp_version == GTP_V1) |
1368 | netdev_dbg(dev, "GTPv1-U: update tunnel id = %x/%x (pdp %p)\n" , |
1369 | pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); |
1370 | |
1371 | return pctx; |
1372 | |
1373 | } |
1374 | |
1375 | pctx = kmalloc(size: sizeof(*pctx), GFP_ATOMIC); |
1376 | if (pctx == NULL) |
1377 | return ERR_PTR(error: -ENOMEM); |
1378 | |
1379 | sock_hold(sk); |
1380 | pctx->sk = sk; |
1381 | pctx->dev = gtp->dev; |
1382 | ipv4_pdp_fill(pctx, info); |
1383 | atomic_set(v: &pctx->tx_seq, i: 0); |
1384 | |
1385 | switch (pctx->gtp_version) { |
1386 | case GTP_V0: |
1387 | /* TS 09.60: "The flow label identifies unambiguously a GTP |
1388 | * flow.". We use the tid for this instead, I cannot find a |
1389 | * situation in which this doesn't unambiguosly identify the |
1390 | * PDP context. |
1391 | */ |
1392 | hash_tid = gtp0_hashfn(tid: pctx->u.v0.tid) % gtp->hash_size; |
1393 | break; |
1394 | case GTP_V1: |
1395 | hash_tid = gtp1u_hashfn(tid: pctx->u.v1.i_tei) % gtp->hash_size; |
1396 | break; |
1397 | } |
1398 | |
1399 | hlist_add_head_rcu(n: &pctx->hlist_addr, h: >p->addr_hash[hash_ms]); |
1400 | hlist_add_head_rcu(n: &pctx->hlist_tid, h: >p->tid_hash[hash_tid]); |
1401 | |
1402 | switch (pctx->gtp_version) { |
1403 | case GTP_V0: |
1404 | netdev_dbg(dev, "GTPv0-U: new PDP ctx id=%llx ssgn=%pI4 ms=%pI4 (pdp=%p)\n" , |
1405 | pctx->u.v0.tid, &pctx->peer_addr_ip4, |
1406 | &pctx->ms_addr_ip4, pctx); |
1407 | break; |
1408 | case GTP_V1: |
1409 | netdev_dbg(dev, "GTPv1-U: new PDP ctx id=%x/%x ssgn=%pI4 ms=%pI4 (pdp=%p)\n" , |
1410 | pctx->u.v1.i_tei, pctx->u.v1.o_tei, |
1411 | &pctx->peer_addr_ip4, &pctx->ms_addr_ip4, pctx); |
1412 | break; |
1413 | } |
1414 | |
1415 | return pctx; |
1416 | } |
1417 | |
1418 | static void pdp_context_free(struct rcu_head *head) |
1419 | { |
1420 | struct pdp_ctx *pctx = container_of(head, struct pdp_ctx, rcu_head); |
1421 | |
1422 | sock_put(sk: pctx->sk); |
1423 | kfree(objp: pctx); |
1424 | } |
1425 | |
1426 | static void pdp_context_delete(struct pdp_ctx *pctx) |
1427 | { |
1428 | hlist_del_rcu(n: &pctx->hlist_tid); |
1429 | hlist_del_rcu(n: &pctx->hlist_addr); |
1430 | call_rcu(head: &pctx->rcu_head, func: pdp_context_free); |
1431 | } |
1432 | |
1433 | static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation); |
1434 | |
1435 | static int gtp_genl_new_pdp(struct sk_buff *skb, struct genl_info *info) |
1436 | { |
1437 | unsigned int version; |
1438 | struct pdp_ctx *pctx; |
1439 | struct gtp_dev *gtp; |
1440 | struct sock *sk; |
1441 | int err; |
1442 | |
1443 | if (!info->attrs[GTPA_VERSION] || |
1444 | !info->attrs[GTPA_LINK] || |
1445 | !info->attrs[GTPA_PEER_ADDRESS] || |
1446 | !info->attrs[GTPA_MS_ADDRESS]) |
1447 | return -EINVAL; |
1448 | |
1449 | version = nla_get_u32(nla: info->attrs[GTPA_VERSION]); |
1450 | |
1451 | switch (version) { |
1452 | case GTP_V0: |
1453 | if (!info->attrs[GTPA_TID] || |
1454 | !info->attrs[GTPA_FLOW]) |
1455 | return -EINVAL; |
1456 | break; |
1457 | case GTP_V1: |
1458 | if (!info->attrs[GTPA_I_TEI] || |
1459 | !info->attrs[GTPA_O_TEI]) |
1460 | return -EINVAL; |
1461 | break; |
1462 | |
1463 | default: |
1464 | return -EINVAL; |
1465 | } |
1466 | |
1467 | rtnl_lock(); |
1468 | |
1469 | gtp = gtp_find_dev(src_net: sock_net(sk: skb->sk), nla: info->attrs); |
1470 | if (!gtp) { |
1471 | err = -ENODEV; |
1472 | goto out_unlock; |
1473 | } |
1474 | |
1475 | if (version == GTP_V0) |
1476 | sk = gtp->sk0; |
1477 | else if (version == GTP_V1) |
1478 | sk = gtp->sk1u; |
1479 | else |
1480 | sk = NULL; |
1481 | |
1482 | if (!sk) { |
1483 | err = -ENODEV; |
1484 | goto out_unlock; |
1485 | } |
1486 | |
1487 | pctx = gtp_pdp_add(gtp, sk, info); |
1488 | if (IS_ERR(ptr: pctx)) { |
1489 | err = PTR_ERR(ptr: pctx); |
1490 | } else { |
1491 | gtp_tunnel_notify(pctx, cmd: GTP_CMD_NEWPDP, GFP_KERNEL); |
1492 | err = 0; |
1493 | } |
1494 | |
1495 | out_unlock: |
1496 | rtnl_unlock(); |
1497 | return err; |
1498 | } |
1499 | |
1500 | static struct pdp_ctx *gtp_find_pdp_by_link(struct net *net, |
1501 | struct nlattr *nla[]) |
1502 | { |
1503 | struct gtp_dev *gtp; |
1504 | |
1505 | gtp = gtp_find_dev(src_net: net, nla); |
1506 | if (!gtp) |
1507 | return ERR_PTR(error: -ENODEV); |
1508 | |
1509 | if (nla[GTPA_MS_ADDRESS]) { |
1510 | __be32 ip = nla_get_be32(nla: nla[GTPA_MS_ADDRESS]); |
1511 | |
1512 | return ipv4_pdp_find(gtp, ms_addr: ip); |
1513 | } else if (nla[GTPA_VERSION]) { |
1514 | u32 gtp_version = nla_get_u32(nla: nla[GTPA_VERSION]); |
1515 | |
1516 | if (gtp_version == GTP_V0 && nla[GTPA_TID]) |
1517 | return gtp0_pdp_find(gtp, tid: nla_get_u64(nla: nla[GTPA_TID])); |
1518 | else if (gtp_version == GTP_V1 && nla[GTPA_I_TEI]) |
1519 | return gtp1_pdp_find(gtp, tid: nla_get_u32(nla: nla[GTPA_I_TEI])); |
1520 | } |
1521 | |
1522 | return ERR_PTR(error: -EINVAL); |
1523 | } |
1524 | |
1525 | static struct pdp_ctx *gtp_find_pdp(struct net *net, struct nlattr *nla[]) |
1526 | { |
1527 | struct pdp_ctx *pctx; |
1528 | |
1529 | if (nla[GTPA_LINK]) |
1530 | pctx = gtp_find_pdp_by_link(net, nla); |
1531 | else |
1532 | pctx = ERR_PTR(error: -EINVAL); |
1533 | |
1534 | if (!pctx) |
1535 | pctx = ERR_PTR(error: -ENOENT); |
1536 | |
1537 | return pctx; |
1538 | } |
1539 | |
1540 | static int gtp_genl_del_pdp(struct sk_buff *skb, struct genl_info *info) |
1541 | { |
1542 | struct pdp_ctx *pctx; |
1543 | int err = 0; |
1544 | |
1545 | if (!info->attrs[GTPA_VERSION]) |
1546 | return -EINVAL; |
1547 | |
1548 | rcu_read_lock(); |
1549 | |
1550 | pctx = gtp_find_pdp(net: sock_net(sk: skb->sk), nla: info->attrs); |
1551 | if (IS_ERR(ptr: pctx)) { |
1552 | err = PTR_ERR(ptr: pctx); |
1553 | goto out_unlock; |
1554 | } |
1555 | |
1556 | if (pctx->gtp_version == GTP_V0) |
1557 | netdev_dbg(pctx->dev, "GTPv0-U: deleting tunnel id = %llx (pdp %p)\n" , |
1558 | pctx->u.v0.tid, pctx); |
1559 | else if (pctx->gtp_version == GTP_V1) |
1560 | netdev_dbg(pctx->dev, "GTPv1-U: deleting tunnel id = %x/%x (pdp %p)\n" , |
1561 | pctx->u.v1.i_tei, pctx->u.v1.o_tei, pctx); |
1562 | |
1563 | gtp_tunnel_notify(pctx, cmd: GTP_CMD_DELPDP, GFP_ATOMIC); |
1564 | pdp_context_delete(pctx); |
1565 | |
1566 | out_unlock: |
1567 | rcu_read_unlock(); |
1568 | return err; |
1569 | } |
1570 | |
1571 | static int gtp_genl_fill_info(struct sk_buff *skb, u32 snd_portid, u32 snd_seq, |
1572 | int flags, u32 type, struct pdp_ctx *pctx) |
1573 | { |
1574 | void *genlh; |
1575 | |
1576 | genlh = genlmsg_put(skb, portid: snd_portid, seq: snd_seq, family: >p_genl_family, flags, |
1577 | cmd: type); |
1578 | if (genlh == NULL) |
1579 | goto nlmsg_failure; |
1580 | |
1581 | if (nla_put_u32(skb, attrtype: GTPA_VERSION, value: pctx->gtp_version) || |
1582 | nla_put_u32(skb, attrtype: GTPA_LINK, value: pctx->dev->ifindex) || |
1583 | nla_put_be32(skb, attrtype: GTPA_PEER_ADDRESS, value: pctx->peer_addr_ip4.s_addr) || |
1584 | nla_put_be32(skb, attrtype: GTPA_MS_ADDRESS, value: pctx->ms_addr_ip4.s_addr)) |
1585 | goto nla_put_failure; |
1586 | |
1587 | switch (pctx->gtp_version) { |
1588 | case GTP_V0: |
1589 | if (nla_put_u64_64bit(skb, attrtype: GTPA_TID, value: pctx->u.v0.tid, padattr: GTPA_PAD) || |
1590 | nla_put_u16(skb, attrtype: GTPA_FLOW, value: pctx->u.v0.flow)) |
1591 | goto nla_put_failure; |
1592 | break; |
1593 | case GTP_V1: |
1594 | if (nla_put_u32(skb, attrtype: GTPA_I_TEI, value: pctx->u.v1.i_tei) || |
1595 | nla_put_u32(skb, attrtype: GTPA_O_TEI, value: pctx->u.v1.o_tei)) |
1596 | goto nla_put_failure; |
1597 | break; |
1598 | } |
1599 | genlmsg_end(skb, hdr: genlh); |
1600 | return 0; |
1601 | |
1602 | nlmsg_failure: |
1603 | nla_put_failure: |
1604 | genlmsg_cancel(skb, hdr: genlh); |
1605 | return -EMSGSIZE; |
1606 | } |
1607 | |
1608 | static int gtp_tunnel_notify(struct pdp_ctx *pctx, u8 cmd, gfp_t allocation) |
1609 | { |
1610 | struct sk_buff *msg; |
1611 | int ret; |
1612 | |
1613 | msg = nlmsg_new(NLMSG_DEFAULT_SIZE, flags: allocation); |
1614 | if (!msg) |
1615 | return -ENOMEM; |
1616 | |
1617 | ret = gtp_genl_fill_info(skb: msg, snd_portid: 0, snd_seq: 0, flags: 0, type: cmd, pctx); |
1618 | if (ret < 0) { |
1619 | nlmsg_free(skb: msg); |
1620 | return ret; |
1621 | } |
1622 | |
1623 | ret = genlmsg_multicast_netns(family: >p_genl_family, net: dev_net(dev: pctx->dev), skb: msg, |
1624 | portid: 0, group: GTP_GENL_MCGRP, GFP_ATOMIC); |
1625 | return ret; |
1626 | } |
1627 | |
1628 | static int gtp_genl_get_pdp(struct sk_buff *skb, struct genl_info *info) |
1629 | { |
1630 | struct pdp_ctx *pctx = NULL; |
1631 | struct sk_buff *skb2; |
1632 | int err; |
1633 | |
1634 | if (!info->attrs[GTPA_VERSION]) |
1635 | return -EINVAL; |
1636 | |
1637 | rcu_read_lock(); |
1638 | |
1639 | pctx = gtp_find_pdp(net: sock_net(sk: skb->sk), nla: info->attrs); |
1640 | if (IS_ERR(ptr: pctx)) { |
1641 | err = PTR_ERR(ptr: pctx); |
1642 | goto err_unlock; |
1643 | } |
1644 | |
1645 | skb2 = genlmsg_new(NLMSG_GOODSIZE, GFP_ATOMIC); |
1646 | if (skb2 == NULL) { |
1647 | err = -ENOMEM; |
1648 | goto err_unlock; |
1649 | } |
1650 | |
1651 | err = gtp_genl_fill_info(skb: skb2, NETLINK_CB(skb).portid, snd_seq: info->snd_seq, |
1652 | flags: 0, type: info->nlhdr->nlmsg_type, pctx); |
1653 | if (err < 0) |
1654 | goto err_unlock_free; |
1655 | |
1656 | rcu_read_unlock(); |
1657 | return genlmsg_unicast(net: genl_info_net(info), skb: skb2, portid: info->snd_portid); |
1658 | |
1659 | err_unlock_free: |
1660 | kfree_skb(skb: skb2); |
1661 | err_unlock: |
1662 | rcu_read_unlock(); |
1663 | return err; |
1664 | } |
1665 | |
1666 | static int gtp_genl_dump_pdp(struct sk_buff *skb, |
1667 | struct netlink_callback *cb) |
1668 | { |
1669 | struct gtp_dev *last_gtp = (struct gtp_dev *)cb->args[2], *gtp; |
1670 | int i, j, bucket = cb->args[0], skip = cb->args[1]; |
1671 | struct net *net = sock_net(sk: skb->sk); |
1672 | struct pdp_ctx *pctx; |
1673 | struct gtp_net *gn; |
1674 | |
1675 | gn = net_generic(net, id: gtp_net_id); |
1676 | |
1677 | if (cb->args[4]) |
1678 | return 0; |
1679 | |
1680 | rcu_read_lock(); |
1681 | list_for_each_entry_rcu(gtp, &gn->gtp_dev_list, list) { |
1682 | if (last_gtp && last_gtp != gtp) |
1683 | continue; |
1684 | else |
1685 | last_gtp = NULL; |
1686 | |
1687 | for (i = bucket; i < gtp->hash_size; i++) { |
1688 | j = 0; |
1689 | hlist_for_each_entry_rcu(pctx, >p->tid_hash[i], |
1690 | hlist_tid) { |
1691 | if (j >= skip && |
1692 | gtp_genl_fill_info(skb, |
1693 | NETLINK_CB(cb->skb).portid, |
1694 | snd_seq: cb->nlh->nlmsg_seq, |
1695 | NLM_F_MULTI, |
1696 | type: cb->nlh->nlmsg_type, pctx)) { |
1697 | cb->args[0] = i; |
1698 | cb->args[1] = j; |
1699 | cb->args[2] = (unsigned long)gtp; |
1700 | goto out; |
1701 | } |
1702 | j++; |
1703 | } |
1704 | skip = 0; |
1705 | } |
1706 | bucket = 0; |
1707 | } |
1708 | cb->args[4] = 1; |
1709 | out: |
1710 | rcu_read_unlock(); |
1711 | return skb->len; |
1712 | } |
1713 | |
1714 | static int gtp_genl_send_echo_req(struct sk_buff *skb, struct genl_info *info) |
1715 | { |
1716 | struct sk_buff *skb_to_send; |
1717 | __be32 src_ip, dst_ip; |
1718 | unsigned int version; |
1719 | struct gtp_dev *gtp; |
1720 | struct flowi4 fl4; |
1721 | struct rtable *rt; |
1722 | struct sock *sk; |
1723 | __be16 port; |
1724 | int len; |
1725 | |
1726 | if (!info->attrs[GTPA_VERSION] || |
1727 | !info->attrs[GTPA_LINK] || |
1728 | !info->attrs[GTPA_PEER_ADDRESS] || |
1729 | !info->attrs[GTPA_MS_ADDRESS]) |
1730 | return -EINVAL; |
1731 | |
1732 | version = nla_get_u32(nla: info->attrs[GTPA_VERSION]); |
1733 | dst_ip = nla_get_be32(nla: info->attrs[GTPA_PEER_ADDRESS]); |
1734 | src_ip = nla_get_be32(nla: info->attrs[GTPA_MS_ADDRESS]); |
1735 | |
1736 | gtp = gtp_find_dev(src_net: sock_net(sk: skb->sk), nla: info->attrs); |
1737 | if (!gtp) |
1738 | return -ENODEV; |
1739 | |
1740 | if (!gtp->sk_created) |
1741 | return -EOPNOTSUPP; |
1742 | if (!(gtp->dev->flags & IFF_UP)) |
1743 | return -ENETDOWN; |
1744 | |
1745 | if (version == GTP_V0) { |
1746 | struct gtp0_header *gtp0_h; |
1747 | |
1748 | len = LL_RESERVED_SPACE(gtp->dev) + sizeof(struct gtp0_header) + |
1749 | sizeof(struct iphdr) + sizeof(struct udphdr); |
1750 | |
1751 | skb_to_send = netdev_alloc_skb_ip_align(dev: gtp->dev, length: len); |
1752 | if (!skb_to_send) |
1753 | return -ENOMEM; |
1754 | |
1755 | sk = gtp->sk0; |
1756 | port = htons(GTP0_PORT); |
1757 | |
1758 | gtp0_h = skb_push(skb: skb_to_send, len: sizeof(struct gtp0_header)); |
1759 | memset(gtp0_h, 0, sizeof(struct gtp0_header)); |
1760 | gtp0_build_echo_msg(hdr: gtp0_h, GTP_ECHO_REQ); |
1761 | } else if (version == GTP_V1) { |
1762 | struct gtp1_header_long *gtp1u_h; |
1763 | |
1764 | len = LL_RESERVED_SPACE(gtp->dev) + |
1765 | sizeof(struct gtp1_header_long) + |
1766 | sizeof(struct iphdr) + sizeof(struct udphdr); |
1767 | |
1768 | skb_to_send = netdev_alloc_skb_ip_align(dev: gtp->dev, length: len); |
1769 | if (!skb_to_send) |
1770 | return -ENOMEM; |
1771 | |
1772 | sk = gtp->sk1u; |
1773 | port = htons(GTP1U_PORT); |
1774 | |
1775 | gtp1u_h = skb_push(skb: skb_to_send, |
1776 | len: sizeof(struct gtp1_header_long)); |
1777 | memset(gtp1u_h, 0, sizeof(struct gtp1_header_long)); |
1778 | gtp1u_build_echo_msg(hdr: gtp1u_h, GTP_ECHO_REQ); |
1779 | } else { |
1780 | return -ENODEV; |
1781 | } |
1782 | |
1783 | rt = ip4_route_output_gtp(fl4: &fl4, sk, daddr: dst_ip, saddr: src_ip); |
1784 | if (IS_ERR(ptr: rt)) { |
1785 | netdev_dbg(gtp->dev, "no route for echo request to %pI4\n" , |
1786 | &dst_ip); |
1787 | kfree_skb(skb: skb_to_send); |
1788 | return -ENODEV; |
1789 | } |
1790 | |
1791 | udp_tunnel_xmit_skb(rt, sk, skb: skb_to_send, |
1792 | src: fl4.saddr, dst: fl4.daddr, |
1793 | tos: fl4.flowi4_tos, |
1794 | ttl: ip4_dst_hoplimit(dst: &rt->dst), |
1795 | df: 0, |
1796 | src_port: port, dst_port: port, |
1797 | xnet: !net_eq(net1: sock_net(sk), |
1798 | net2: dev_net(dev: gtp->dev)), |
1799 | nocheck: false); |
1800 | return 0; |
1801 | } |
1802 | |
1803 | static const struct nla_policy gtp_genl_policy[GTPA_MAX + 1] = { |
1804 | [GTPA_LINK] = { .type = NLA_U32, }, |
1805 | [GTPA_VERSION] = { .type = NLA_U32, }, |
1806 | [GTPA_TID] = { .type = NLA_U64, }, |
1807 | [GTPA_PEER_ADDRESS] = { .type = NLA_U32, }, |
1808 | [GTPA_MS_ADDRESS] = { .type = NLA_U32, }, |
1809 | [GTPA_FLOW] = { .type = NLA_U16, }, |
1810 | [GTPA_NET_NS_FD] = { .type = NLA_U32, }, |
1811 | [GTPA_I_TEI] = { .type = NLA_U32, }, |
1812 | [GTPA_O_TEI] = { .type = NLA_U32, }, |
1813 | }; |
1814 | |
1815 | static const struct genl_small_ops gtp_genl_ops[] = { |
1816 | { |
1817 | .cmd = GTP_CMD_NEWPDP, |
1818 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
1819 | .doit = gtp_genl_new_pdp, |
1820 | .flags = GENL_ADMIN_PERM, |
1821 | }, |
1822 | { |
1823 | .cmd = GTP_CMD_DELPDP, |
1824 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
1825 | .doit = gtp_genl_del_pdp, |
1826 | .flags = GENL_ADMIN_PERM, |
1827 | }, |
1828 | { |
1829 | .cmd = GTP_CMD_GETPDP, |
1830 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
1831 | .doit = gtp_genl_get_pdp, |
1832 | .dumpit = gtp_genl_dump_pdp, |
1833 | .flags = GENL_ADMIN_PERM, |
1834 | }, |
1835 | { |
1836 | .cmd = GTP_CMD_ECHOREQ, |
1837 | .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP, |
1838 | .doit = gtp_genl_send_echo_req, |
1839 | .flags = GENL_ADMIN_PERM, |
1840 | }, |
1841 | }; |
1842 | |
1843 | static struct genl_family gtp_genl_family __ro_after_init = { |
1844 | .name = "gtp" , |
1845 | .version = 0, |
1846 | .hdrsize = 0, |
1847 | .maxattr = GTPA_MAX, |
1848 | .policy = gtp_genl_policy, |
1849 | .netnsok = true, |
1850 | .module = THIS_MODULE, |
1851 | .small_ops = gtp_genl_ops, |
1852 | .n_small_ops = ARRAY_SIZE(gtp_genl_ops), |
1853 | .resv_start_op = GTP_CMD_ECHOREQ + 1, |
1854 | .mcgrps = gtp_genl_mcgrps, |
1855 | .n_mcgrps = ARRAY_SIZE(gtp_genl_mcgrps), |
1856 | }; |
1857 | |
1858 | static int __net_init gtp_net_init(struct net *net) |
1859 | { |
1860 | struct gtp_net *gn = net_generic(net, id: gtp_net_id); |
1861 | |
1862 | INIT_LIST_HEAD(list: &gn->gtp_dev_list); |
1863 | return 0; |
1864 | } |
1865 | |
1866 | static void __net_exit gtp_net_exit_batch_rtnl(struct list_head *net_list, |
1867 | struct list_head *dev_to_kill) |
1868 | { |
1869 | struct net *net; |
1870 | |
1871 | list_for_each_entry(net, net_list, exit_list) { |
1872 | struct gtp_net *gn = net_generic(net, id: gtp_net_id); |
1873 | struct gtp_dev *gtp; |
1874 | |
1875 | list_for_each_entry(gtp, &gn->gtp_dev_list, list) |
1876 | gtp_dellink(dev: gtp->dev, head: dev_to_kill); |
1877 | } |
1878 | } |
1879 | |
1880 | static struct pernet_operations gtp_net_ops = { |
1881 | .init = gtp_net_init, |
1882 | .exit_batch_rtnl = gtp_net_exit_batch_rtnl, |
1883 | .id = >p_net_id, |
1884 | .size = sizeof(struct gtp_net), |
1885 | }; |
1886 | |
1887 | static int __init gtp_init(void) |
1888 | { |
1889 | int err; |
1890 | |
1891 | get_random_bytes(buf: >p_h_initval, len: sizeof(gtp_h_initval)); |
1892 | |
1893 | err = register_pernet_subsys(>p_net_ops); |
1894 | if (err < 0) |
1895 | goto error_out; |
1896 | |
1897 | err = rtnl_link_register(ops: >p_link_ops); |
1898 | if (err < 0) |
1899 | goto unreg_pernet_subsys; |
1900 | |
1901 | err = genl_register_family(family: >p_genl_family); |
1902 | if (err < 0) |
1903 | goto unreg_rtnl_link; |
1904 | |
1905 | pr_info("GTP module loaded (pdp ctx size %zd bytes)\n" , |
1906 | sizeof(struct pdp_ctx)); |
1907 | return 0; |
1908 | |
1909 | unreg_rtnl_link: |
1910 | rtnl_link_unregister(ops: >p_link_ops); |
1911 | unreg_pernet_subsys: |
1912 | unregister_pernet_subsys(>p_net_ops); |
1913 | error_out: |
1914 | pr_err("error loading GTP module loaded\n" ); |
1915 | return err; |
1916 | } |
1917 | late_initcall(gtp_init); |
1918 | |
1919 | static void __exit gtp_fini(void) |
1920 | { |
1921 | genl_unregister_family(family: >p_genl_family); |
1922 | rtnl_link_unregister(ops: >p_link_ops); |
1923 | unregister_pernet_subsys(>p_net_ops); |
1924 | |
1925 | pr_info("GTP module unloaded\n" ); |
1926 | } |
1927 | module_exit(gtp_fini); |
1928 | |
1929 | MODULE_LICENSE("GPL" ); |
1930 | MODULE_AUTHOR("Harald Welte <hwelte@sysmocom.de>" ); |
1931 | MODULE_DESCRIPTION("Interface driver for GTP encapsulated traffic" ); |
1932 | MODULE_ALIAS_RTNL_LINK("gtp" ); |
1933 | MODULE_ALIAS_GENL_FAMILY("gtp" ); |
1934 | |