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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * File: af_phonet.c
4 *
5 * Phonet protocols family
6 *
7 * Copyright (C) 2008 Nokia Corporation.
8 *
9 * Authors: Sakari Ailus <sakari.ailus@nokia.com>
10 * Rémi Denis-Courmont
11 */
12
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <asm/unaligned.h>
17#include <net/sock.h>
18
19#include <linux/if_phonet.h>
20#include <linux/phonet.h>
21#include <net/phonet/phonet.h>
22#include <net/phonet/pn_dev.h>
23
24/* Transport protocol registration */
25static const struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
26
27static const struct phonet_protocol *phonet_proto_get(unsigned int protocol)
28{
29 const struct phonet_protocol *pp;
30
31 if (protocol >= PHONET_NPROTO)
32 return NULL;
33
34 rcu_read_lock();
35 pp = rcu_dereference(proto_tab[protocol]);
36 if (pp && !try_module_get(pp->prot->owner))
37 pp = NULL;
38 rcu_read_unlock();
39
40 return pp;
41}
42
43static inline void phonet_proto_put(const struct phonet_protocol *pp)
44{
45 module_put(pp->prot->owner);
46}
47
48/* protocol family functions */
49
50static int pn_socket_create(struct net *net, struct socket *sock, int protocol,
51 int kern)
52{
53 struct sock *sk;
54 struct pn_sock *pn;
55 const struct phonet_protocol *pnp;
56 int err;
57
58 if (!capable(CAP_SYS_ADMIN))
59 return -EPERM;
60
61 if (protocol == 0) {
62 /* Default protocol selection */
63 switch (sock->type) {
64 case SOCK_DGRAM:
65 protocol = PN_PROTO_PHONET;
66 break;
67 case SOCK_SEQPACKET:
68 protocol = PN_PROTO_PIPE;
69 break;
70 default:
71 return -EPROTONOSUPPORT;
72 }
73 }
74
75 pnp = phonet_proto_get(protocol);
76 if (pnp == NULL &&
77 request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
78 pnp = phonet_proto_get(protocol);
79
80 if (pnp == NULL)
81 return -EPROTONOSUPPORT;
82 if (sock->type != pnp->sock_type) {
83 err = -EPROTONOSUPPORT;
84 goto out;
85 }
86
87 sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot, kern);
88 if (sk == NULL) {
89 err = -ENOMEM;
90 goto out;
91 }
92
93 sock_init_data(sock, sk);
94 sock->state = SS_UNCONNECTED;
95 sock->ops = pnp->ops;
96 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
97 sk->sk_protocol = protocol;
98 pn = pn_sk(sk);
99 pn->sobject = 0;
100 pn->dobject = 0;
101 pn->resource = 0;
102 sk->sk_prot->init(sk);
103 err = 0;
104
105out:
106 phonet_proto_put(pnp);
107 return err;
108}
109
110static const struct net_proto_family phonet_proto_family = {
111 .family = PF_PHONET,
112 .create = pn_socket_create,
113 .owner = THIS_MODULE,
114};
115
116/* Phonet device header operations */
117static int pn_header_create(struct sk_buff *skb, struct net_device *dev,
118 unsigned short type, const void *daddr,
119 const void *saddr, unsigned int len)
120{
121 u8 *media = skb_push(skb, 1);
122
123 if (type != ETH_P_PHONET)
124 return -1;
125
126 if (!saddr)
127 saddr = dev->dev_addr;
128 *media = *(const u8 *)saddr;
129 return 1;
130}
131
132static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr)
133{
134 const u8 *media = skb_mac_header(skb);
135 *haddr = *media;
136 return 1;
137}
138
139const struct header_ops phonet_header_ops = {
140 .create = pn_header_create,
141 .parse = pn_header_parse,
142};
143EXPORT_SYMBOL(phonet_header_ops);
144
145/*
146 * Prepends an ISI header and sends a datagram.
147 */
148static int pn_send(struct sk_buff *skb, struct net_device *dev,
149 u16 dst, u16 src, u8 res)
150{
151 struct phonethdr *ph;
152 int err;
153
154 if (skb->len + 2 > 0xffff /* Phonet length field limit */ ||
155 skb->len + sizeof(struct phonethdr) > dev->mtu) {
156 err = -EMSGSIZE;
157 goto drop;
158 }
159
160 /* Broadcast sending is not implemented */
161 if (pn_addr(dst) == PNADDR_BROADCAST) {
162 err = -EOPNOTSUPP;
163 goto drop;
164 }
165
166 skb_reset_transport_header(skb);
167 WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
168 skb_push(skb, sizeof(struct phonethdr));
169 skb_reset_network_header(skb);
170 ph = pn_hdr(skb);
171 ph->pn_rdev = pn_dev(dst);
172 ph->pn_sdev = pn_dev(src);
173 ph->pn_res = res;
174 ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
175 ph->pn_robj = pn_obj(dst);
176 ph->pn_sobj = pn_obj(src);
177
178 skb->protocol = htons(ETH_P_PHONET);
179 skb->priority = 0;
180 skb->dev = dev;
181
182 if (skb->pkt_type == PACKET_LOOPBACK) {
183 skb_reset_mac_header(skb);
184 skb_orphan(skb);
185 err = netif_rx(skb) ? -ENOBUFS : 0;
186 } else {
187 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
188 NULL, NULL, skb->len);
189 if (err < 0) {
190 err = -EHOSTUNREACH;
191 goto drop;
192 }
193 err = dev_queue_xmit(skb);
194 if (unlikely(err > 0))
195 err = net_xmit_errno(err);
196 }
197
198 return err;
199drop:
200 kfree_skb(skb);
201 return err;
202}
203
204static int pn_raw_send(const void *data, int len, struct net_device *dev,
205 u16 dst, u16 src, u8 res)
206{
207 struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
208 if (skb == NULL)
209 return -ENOMEM;
210
211 if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
212 skb->pkt_type = PACKET_LOOPBACK;
213
214 skb_reserve(skb, MAX_PHONET_HEADER);
215 __skb_put(skb, len);
216 skb_copy_to_linear_data(skb, data, len);
217 return pn_send(skb, dev, dst, src, res);
218}
219
220/*
221 * Create a Phonet header for the skb and send it out. Returns
222 * non-zero error code if failed. The skb is freed then.
223 */
224int pn_skb_send(struct sock *sk, struct sk_buff *skb,
225 const struct sockaddr_pn *target)
226{
227 struct net *net = sock_net(sk);
228 struct net_device *dev;
229 struct pn_sock *pn = pn_sk(sk);
230 int err;
231 u16 src, dst;
232 u8 daddr, saddr, res;
233
234 src = pn->sobject;
235 if (target != NULL) {
236 dst = pn_sockaddr_get_object(target);
237 res = pn_sockaddr_get_resource(target);
238 } else {
239 dst = pn->dobject;
240 res = pn->resource;
241 }
242 daddr = pn_addr(dst);
243
244 err = -EHOSTUNREACH;
245 if (sk->sk_bound_dev_if)
246 dev = dev_get_by_index(net, sk->sk_bound_dev_if);
247 else if (phonet_address_lookup(net, daddr) == 0) {
248 dev = phonet_device_get(net);
249 skb->pkt_type = PACKET_LOOPBACK;
250 } else if (dst == 0) {
251 /* Resource routing (small race until phonet_rcv()) */
252 struct sock *sk = pn_find_sock_by_res(net, res);
253 if (sk) {
254 sock_put(sk);
255 dev = phonet_device_get(net);
256 skb->pkt_type = PACKET_LOOPBACK;
257 } else
258 dev = phonet_route_output(net, daddr);
259 } else
260 dev = phonet_route_output(net, daddr);
261
262 if (!dev || !(dev->flags & IFF_UP))
263 goto drop;
264
265 saddr = phonet_address_get(dev, daddr);
266 if (saddr == PN_NO_ADDR)
267 goto drop;
268
269 if (!pn_addr(src))
270 src = pn_object(saddr, pn_obj(src));
271
272 err = pn_send(skb, dev, dst, src, res);
273 dev_put(dev);
274 return err;
275
276drop:
277 kfree_skb(skb);
278 dev_put(dev);
279 return err;
280}
281EXPORT_SYMBOL(pn_skb_send);
282
283/* Do not send an error message in response to an error message */
284static inline int can_respond(struct sk_buff *skb)
285{
286 const struct phonethdr *ph;
287 const struct phonetmsg *pm;
288 u8 submsg_id;
289
290 if (!pskb_may_pull(skb, 3))
291 return 0;
292
293 ph = pn_hdr(skb);
294 if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
295 return 0;
296 if (ph->pn_res == PN_COMMGR) /* indications */
297 return 0;
298
299 ph = pn_hdr(skb); /* re-acquires the pointer */
300 pm = pn_msg(skb);
301 if (pm->pn_msg_id != PN_COMMON_MESSAGE)
302 return 1;
303 submsg_id = (ph->pn_res == PN_PREFIX)
304 ? pm->pn_e_submsg_id : pm->pn_submsg_id;
305 if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
306 pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
307 return 1;
308 return 0;
309}
310
311static int send_obj_unreachable(struct sk_buff *rskb)
312{
313 const struct phonethdr *oph = pn_hdr(rskb);
314 const struct phonetmsg *opm = pn_msg(rskb);
315 struct phonetmsg resp;
316
317 memset(&resp, 0, sizeof(resp));
318 resp.pn_trans_id = opm->pn_trans_id;
319 resp.pn_msg_id = PN_COMMON_MESSAGE;
320 if (oph->pn_res == PN_PREFIX) {
321 resp.pn_e_res_id = opm->pn_e_res_id;
322 resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
323 resp.pn_e_orig_msg_id = opm->pn_msg_id;
324 resp.pn_e_status = 0;
325 } else {
326 resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
327 resp.pn_orig_msg_id = opm->pn_msg_id;
328 resp.pn_status = 0;
329 }
330 return pn_raw_send(&resp, sizeof(resp), rskb->dev,
331 pn_object(oph->pn_sdev, oph->pn_sobj),
332 pn_object(oph->pn_rdev, oph->pn_robj),
333 oph->pn_res);
334}
335
336static int send_reset_indications(struct sk_buff *rskb)
337{
338 struct phonethdr *oph = pn_hdr(rskb);
339 static const u8 data[4] = {
340 0x00 /* trans ID */, 0x10 /* subscribe msg */,
341 0x00 /* subscription count */, 0x00 /* dummy */
342 };
343
344 return pn_raw_send(data, sizeof(data), rskb->dev,
345 pn_object(oph->pn_sdev, 0x00),
346 pn_object(oph->pn_rdev, oph->pn_robj),
347 PN_COMMGR);
348}
349
350
351/* packet type functions */
352
353/*
354 * Stuff received packets to associated sockets.
355 * On error, returns non-zero and releases the skb.
356 */
357static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
358 struct packet_type *pkttype,
359 struct net_device *orig_dev)
360{
361 struct net *net = dev_net(dev);
362 struct phonethdr *ph;
363 struct sockaddr_pn sa;
364 u16 len;
365
366 skb = skb_share_check(skb, GFP_ATOMIC);
367 if (!skb)
368 return NET_RX_DROP;
369
370 /* check we have at least a full Phonet header */
371 if (!pskb_pull(skb, sizeof(struct phonethdr)))
372 goto out;
373
374 /* check that the advertised length is correct */
375 ph = pn_hdr(skb);
376 len = get_unaligned_be16(&ph->pn_length);
377 if (len < 2)
378 goto out;
379 len -= 2;
380 if ((len > skb->len) || pskb_trim(skb, len))
381 goto out;
382 skb_reset_transport_header(skb);
383
384 pn_skb_get_dst_sockaddr(skb, &sa);
385
386 /* check if this is broadcasted */
387 if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
388 pn_deliver_sock_broadcast(net, skb);
389 goto out;
390 }
391
392 /* resource routing */
393 if (pn_sockaddr_get_object(&sa) == 0) {
394 struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource);
395 if (sk)
396 return sk_receive_skb(sk, skb, 0);
397 }
398
399 /* check if we are the destination */
400 if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
401 /* Phonet packet input */
402 struct sock *sk = pn_find_sock_by_sa(net, &sa);
403
404 if (sk)
405 return sk_receive_skb(sk, skb, 0);
406
407 if (can_respond(skb)) {
408 send_obj_unreachable(skb);
409 send_reset_indications(skb);
410 }
411 } else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
412 goto out; /* Race between address deletion and loopback */
413 else {
414 /* Phonet packet routing */
415 struct net_device *out_dev;
416
417 out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
418 if (!out_dev) {
419 net_dbg_ratelimited("No Phonet route to %02X\n",
420 pn_sockaddr_get_addr(&sa));
421 goto out;
422 }
423
424 __skb_push(skb, sizeof(struct phonethdr));
425 skb->dev = out_dev;
426 if (out_dev == dev) {
427 net_dbg_ratelimited("Phonet loop to %02X on %s\n",
428 pn_sockaddr_get_addr(&sa),
429 dev->name);
430 goto out_dev;
431 }
432 /* Some drivers (e.g. TUN) do not allocate HW header space */
433 if (skb_cow_head(skb, out_dev->hard_header_len))
434 goto out_dev;
435
436 if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
437 skb->len) < 0)
438 goto out_dev;
439 dev_queue_xmit(skb);
440 dev_put(out_dev);
441 return NET_RX_SUCCESS;
442out_dev:
443 dev_put(out_dev);
444 }
445
446out:
447 kfree_skb(skb);
448 return NET_RX_DROP;
449}
450
451static struct packet_type phonet_packet_type __read_mostly = {
452 .type = cpu_to_be16(ETH_P_PHONET),
453 .func = phonet_rcv,
454};
455
456static DEFINE_MUTEX(proto_tab_lock);
457
458int __init_or_module phonet_proto_register(unsigned int protocol,
459 const struct phonet_protocol *pp)
460{
461 int err = 0;
462
463 if (protocol >= PHONET_NPROTO)
464 return -EINVAL;
465
466 err = proto_register(pp->prot, 1);
467 if (err)
468 return err;
469
470 mutex_lock(&proto_tab_lock);
471 if (proto_tab[protocol])
472 err = -EBUSY;
473 else
474 rcu_assign_pointer(proto_tab[protocol], pp);
475 mutex_unlock(&proto_tab_lock);
476
477 return err;
478}
479EXPORT_SYMBOL(phonet_proto_register);
480
481void phonet_proto_unregister(unsigned int protocol,
482 const struct phonet_protocol *pp)
483{
484 mutex_lock(&proto_tab_lock);
485 BUG_ON(proto_tab[protocol] != pp);
486 RCU_INIT_POINTER(proto_tab[protocol], NULL);
487 mutex_unlock(&proto_tab_lock);
488 synchronize_rcu();
489 proto_unregister(pp->prot);
490}
491EXPORT_SYMBOL(phonet_proto_unregister);
492
493/* Module registration */
494static int __init phonet_init(void)
495{
496 int err;
497
498 err = phonet_device_init();
499 if (err)
500 return err;
501
502 pn_sock_init();
503 err = sock_register(&phonet_proto_family);
504 if (err) {
505 printk(KERN_ALERT
506 "phonet protocol family initialization failed\n");
507 goto err_sock;
508 }
509
510 dev_add_pack(&phonet_packet_type);
511 phonet_sysctl_init();
512
513 err = isi_register();
514 if (err)
515 goto err;
516 return 0;
517
518err:
519 phonet_sysctl_exit();
520 sock_unregister(PF_PHONET);
521 dev_remove_pack(&phonet_packet_type);
522err_sock:
523 phonet_device_exit();
524 return err;
525}
526
527static void __exit phonet_exit(void)
528{
529 isi_unregister();
530 phonet_sysctl_exit();
531 sock_unregister(PF_PHONET);
532 dev_remove_pack(&phonet_packet_type);
533 phonet_device_exit();
534}
535
536module_init(phonet_init);
537module_exit(phonet_exit);
538MODULE_DESCRIPTION("Phonet protocol stack for Linux");
539MODULE_LICENSE("GPL");
540MODULE_ALIAS_NETPROTO(PF_PHONET);
1/*
2 * File: af_phonet.c
3 *
4 * Phonet protocols family
5 *
6 * Copyright (C) 2008 Nokia Corporation.
7 *
8 * Contact: Remi Denis-Courmont <remi.denis-courmont@nokia.com>
9 * Original author: Sakari Ailus <sakari.ailus@nokia.com>
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * version 2 as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
23 * 02110-1301 USA
24 */
25
26#include <linux/kernel.h>
27#include <linux/module.h>
28#include <linux/slab.h>
29#include <asm/unaligned.h>
30#include <net/sock.h>
31
32#include <linux/if_phonet.h>
33#include <linux/phonet.h>
34#include <net/phonet/phonet.h>
35#include <net/phonet/pn_dev.h>
36
37/* Transport protocol registration */
38static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly;
39
40static struct phonet_protocol *phonet_proto_get(unsigned int protocol)
41{
42 struct phonet_protocol *pp;
43
44 if (protocol >= PHONET_NPROTO)
45 return NULL;
46
47 rcu_read_lock();
48 pp = rcu_dereference(proto_tab[protocol]);
49 if (pp && !try_module_get(pp->prot->owner))
50 pp = NULL;
51 rcu_read_unlock();
52
53 return pp;
54}
55
56static inline void phonet_proto_put(struct phonet_protocol *pp)
57{
58 module_put(pp->prot->owner);
59}
60
61/* protocol family functions */
62
63static int pn_socket_create(struct net *net, struct socket *sock, int protocol,
64 int kern)
65{
66 struct sock *sk;
67 struct pn_sock *pn;
68 struct phonet_protocol *pnp;
69 int err;
70
71 if (!capable(CAP_SYS_ADMIN))
72 return -EPERM;
73
74 if (protocol == 0) {
75 /* Default protocol selection */
76 switch (sock->type) {
77 case SOCK_DGRAM:
78 protocol = PN_PROTO_PHONET;
79 break;
80 case SOCK_SEQPACKET:
81 protocol = PN_PROTO_PIPE;
82 break;
83 default:
84 return -EPROTONOSUPPORT;
85 }
86 }
87
88 pnp = phonet_proto_get(protocol);
89 if (pnp == NULL &&
90 request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0)
91 pnp = phonet_proto_get(protocol);
92
93 if (pnp == NULL)
94 return -EPROTONOSUPPORT;
95 if (sock->type != pnp->sock_type) {
96 err = -EPROTONOSUPPORT;
97 goto out;
98 }
99
100 sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot);
101 if (sk == NULL) {
102 err = -ENOMEM;
103 goto out;
104 }
105
106 sock_init_data(sock, sk);
107 sock->state = SS_UNCONNECTED;
108 sock->ops = pnp->ops;
109 sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
110 sk->sk_protocol = protocol;
111 pn = pn_sk(sk);
112 pn->sobject = 0;
113 pn->dobject = 0;
114 pn->resource = 0;
115 sk->sk_prot->init(sk);
116 err = 0;
117
118out:
119 phonet_proto_put(pnp);
120 return err;
121}
122
123static const struct net_proto_family phonet_proto_family = {
124 .family = PF_PHONET,
125 .create = pn_socket_create,
126 .owner = THIS_MODULE,
127};
128
129/* Phonet device header operations */
130static int pn_header_create(struct sk_buff *skb, struct net_device *dev,
131 unsigned short type, const void *daddr,
132 const void *saddr, unsigned len)
133{
134 u8 *media = skb_push(skb, 1);
135
136 if (type != ETH_P_PHONET)
137 return -1;
138
139 if (!saddr)
140 saddr = dev->dev_addr;
141 *media = *(const u8 *)saddr;
142 return 1;
143}
144
145static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr)
146{
147 const u8 *media = skb_mac_header(skb);
148 *haddr = *media;
149 return 1;
150}
151
152struct header_ops phonet_header_ops = {
153 .create = pn_header_create,
154 .parse = pn_header_parse,
155};
156EXPORT_SYMBOL(phonet_header_ops);
157
158/*
159 * Prepends an ISI header and sends a datagram.
160 */
161static int pn_send(struct sk_buff *skb, struct net_device *dev,
162 u16 dst, u16 src, u8 res, u8 irq)
163{
164 struct phonethdr *ph;
165 int err;
166
167 if (skb->len + 2 > 0xffff /* Phonet length field limit */ ||
168 skb->len + sizeof(struct phonethdr) > dev->mtu) {
169 err = -EMSGSIZE;
170 goto drop;
171 }
172
173 /* Broadcast sending is not implemented */
174 if (pn_addr(dst) == PNADDR_BROADCAST) {
175 err = -EOPNOTSUPP;
176 goto drop;
177 }
178
179 skb_reset_transport_header(skb);
180 WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */
181 skb_push(skb, sizeof(struct phonethdr));
182 skb_reset_network_header(skb);
183 ph = pn_hdr(skb);
184 ph->pn_rdev = pn_dev(dst);
185 ph->pn_sdev = pn_dev(src);
186 ph->pn_res = res;
187 ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph));
188 ph->pn_robj = pn_obj(dst);
189 ph->pn_sobj = pn_obj(src);
190
191 skb->protocol = htons(ETH_P_PHONET);
192 skb->priority = 0;
193 skb->dev = dev;
194
195 if (skb->pkt_type == PACKET_LOOPBACK) {
196 skb_reset_mac_header(skb);
197 skb_orphan(skb);
198 err = (irq ? netif_rx(skb) : netif_rx_ni(skb)) ? -ENOBUFS : 0;
199 } else {
200 err = dev_hard_header(skb, dev, ntohs(skb->protocol),
201 NULL, NULL, skb->len);
202 if (err < 0) {
203 err = -EHOSTUNREACH;
204 goto drop;
205 }
206 err = dev_queue_xmit(skb);
207 if (unlikely(err > 0))
208 err = net_xmit_errno(err);
209 }
210
211 return err;
212drop:
213 kfree_skb(skb);
214 return err;
215}
216
217static int pn_raw_send(const void *data, int len, struct net_device *dev,
218 u16 dst, u16 src, u8 res)
219{
220 struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC);
221 if (skb == NULL)
222 return -ENOMEM;
223
224 if (phonet_address_lookup(dev_net(dev), pn_addr(dst)) == 0)
225 skb->pkt_type = PACKET_LOOPBACK;
226
227 skb_reserve(skb, MAX_PHONET_HEADER);
228 __skb_put(skb, len);
229 skb_copy_to_linear_data(skb, data, len);
230 return pn_send(skb, dev, dst, src, res, 1);
231}
232
233/*
234 * Create a Phonet header for the skb and send it out. Returns
235 * non-zero error code if failed. The skb is freed then.
236 */
237int pn_skb_send(struct sock *sk, struct sk_buff *skb,
238 const struct sockaddr_pn *target)
239{
240 struct net *net = sock_net(sk);
241 struct net_device *dev;
242 struct pn_sock *pn = pn_sk(sk);
243 int err;
244 u16 src, dst;
245 u8 daddr, saddr, res;
246
247 src = pn->sobject;
248 if (target != NULL) {
249 dst = pn_sockaddr_get_object(target);
250 res = pn_sockaddr_get_resource(target);
251 } else {
252 dst = pn->dobject;
253 res = pn->resource;
254 }
255 daddr = pn_addr(dst);
256
257 err = -EHOSTUNREACH;
258 if (sk->sk_bound_dev_if)
259 dev = dev_get_by_index(net, sk->sk_bound_dev_if);
260 else if (phonet_address_lookup(net, daddr) == 0) {
261 dev = phonet_device_get(net);
262 skb->pkt_type = PACKET_LOOPBACK;
263 } else if (dst == 0) {
264 /* Resource routing (small race until phonet_rcv()) */
265 struct sock *sk = pn_find_sock_by_res(net, res);
266 if (sk) {
267 sock_put(sk);
268 dev = phonet_device_get(net);
269 skb->pkt_type = PACKET_LOOPBACK;
270 } else
271 dev = phonet_route_output(net, daddr);
272 } else
273 dev = phonet_route_output(net, daddr);
274
275 if (!dev || !(dev->flags & IFF_UP))
276 goto drop;
277
278 saddr = phonet_address_get(dev, daddr);
279 if (saddr == PN_NO_ADDR)
280 goto drop;
281
282 if (!pn_addr(src))
283 src = pn_object(saddr, pn_obj(src));
284
285 err = pn_send(skb, dev, dst, src, res, 0);
286 dev_put(dev);
287 return err;
288
289drop:
290 kfree_skb(skb);
291 if (dev)
292 dev_put(dev);
293 return err;
294}
295EXPORT_SYMBOL(pn_skb_send);
296
297/* Do not send an error message in response to an error message */
298static inline int can_respond(struct sk_buff *skb)
299{
300 const struct phonethdr *ph;
301 const struct phonetmsg *pm;
302 u8 submsg_id;
303
304 if (!pskb_may_pull(skb, 3))
305 return 0;
306
307 ph = pn_hdr(skb);
308 if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5))
309 return 0;
310 if (ph->pn_res == PN_COMMGR) /* indications */
311 return 0;
312
313 ph = pn_hdr(skb); /* re-acquires the pointer */
314 pm = pn_msg(skb);
315 if (pm->pn_msg_id != PN_COMMON_MESSAGE)
316 return 1;
317 submsg_id = (ph->pn_res == PN_PREFIX)
318 ? pm->pn_e_submsg_id : pm->pn_submsg_id;
319 if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP &&
320 pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP)
321 return 1;
322 return 0;
323}
324
325static int send_obj_unreachable(struct sk_buff *rskb)
326{
327 const struct phonethdr *oph = pn_hdr(rskb);
328 const struct phonetmsg *opm = pn_msg(rskb);
329 struct phonetmsg resp;
330
331 memset(&resp, 0, sizeof(resp));
332 resp.pn_trans_id = opm->pn_trans_id;
333 resp.pn_msg_id = PN_COMMON_MESSAGE;
334 if (oph->pn_res == PN_PREFIX) {
335 resp.pn_e_res_id = opm->pn_e_res_id;
336 resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
337 resp.pn_e_orig_msg_id = opm->pn_msg_id;
338 resp.pn_e_status = 0;
339 } else {
340 resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP;
341 resp.pn_orig_msg_id = opm->pn_msg_id;
342 resp.pn_status = 0;
343 }
344 return pn_raw_send(&resp, sizeof(resp), rskb->dev,
345 pn_object(oph->pn_sdev, oph->pn_sobj),
346 pn_object(oph->pn_rdev, oph->pn_robj),
347 oph->pn_res);
348}
349
350static int send_reset_indications(struct sk_buff *rskb)
351{
352 struct phonethdr *oph = pn_hdr(rskb);
353 static const u8 data[4] = {
354 0x00 /* trans ID */, 0x10 /* subscribe msg */,
355 0x00 /* subscription count */, 0x00 /* dummy */
356 };
357
358 return pn_raw_send(data, sizeof(data), rskb->dev,
359 pn_object(oph->pn_sdev, 0x00),
360 pn_object(oph->pn_rdev, oph->pn_robj),
361 PN_COMMGR);
362}
363
364
365/* packet type functions */
366
367/*
368 * Stuff received packets to associated sockets.
369 * On error, returns non-zero and releases the skb.
370 */
371static int phonet_rcv(struct sk_buff *skb, struct net_device *dev,
372 struct packet_type *pkttype,
373 struct net_device *orig_dev)
374{
375 struct net *net = dev_net(dev);
376 struct phonethdr *ph;
377 struct sockaddr_pn sa;
378 u16 len;
379
380 /* check we have at least a full Phonet header */
381 if (!pskb_pull(skb, sizeof(struct phonethdr)))
382 goto out;
383
384 /* check that the advertised length is correct */
385 ph = pn_hdr(skb);
386 len = get_unaligned_be16(&ph->pn_length);
387 if (len < 2)
388 goto out;
389 len -= 2;
390 if ((len > skb->len) || pskb_trim(skb, len))
391 goto out;
392 skb_reset_transport_header(skb);
393
394 pn_skb_get_dst_sockaddr(skb, &sa);
395
396 /* check if this is broadcasted */
397 if (pn_sockaddr_get_addr(&sa) == PNADDR_BROADCAST) {
398 pn_deliver_sock_broadcast(net, skb);
399 goto out;
400 }
401
402 /* resource routing */
403 if (pn_sockaddr_get_object(&sa) == 0) {
404 struct sock *sk = pn_find_sock_by_res(net, sa.spn_resource);
405 if (sk)
406 return sk_receive_skb(sk, skb, 0);
407 }
408
409 /* check if we are the destination */
410 if (phonet_address_lookup(net, pn_sockaddr_get_addr(&sa)) == 0) {
411 /* Phonet packet input */
412 struct sock *sk = pn_find_sock_by_sa(net, &sa);
413
414 if (sk)
415 return sk_receive_skb(sk, skb, 0);
416
417 if (can_respond(skb)) {
418 send_obj_unreachable(skb);
419 send_reset_indications(skb);
420 }
421 } else if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
422 goto out; /* Race between address deletion and loopback */
423 else {
424 /* Phonet packet routing */
425 struct net_device *out_dev;
426
427 out_dev = phonet_route_output(net, pn_sockaddr_get_addr(&sa));
428 if (!out_dev) {
429 LIMIT_NETDEBUG(KERN_WARNING"No Phonet route to %02X\n",
430 pn_sockaddr_get_addr(&sa));
431 goto out;
432 }
433
434 __skb_push(skb, sizeof(struct phonethdr));
435 skb->dev = out_dev;
436 if (out_dev == dev) {
437 LIMIT_NETDEBUG(KERN_ERR"Phonet loop to %02X on %s\n",
438 pn_sockaddr_get_addr(&sa), dev->name);
439 goto out_dev;
440 }
441 /* Some drivers (e.g. TUN) do not allocate HW header space */
442 if (skb_cow_head(skb, out_dev->hard_header_len))
443 goto out_dev;
444
445 if (dev_hard_header(skb, out_dev, ETH_P_PHONET, NULL, NULL,
446 skb->len) < 0)
447 goto out_dev;
448 dev_queue_xmit(skb);
449 dev_put(out_dev);
450 return NET_RX_SUCCESS;
451out_dev:
452 dev_put(out_dev);
453 }
454
455out:
456 kfree_skb(skb);
457 return NET_RX_DROP;
458}
459
460static struct packet_type phonet_packet_type __read_mostly = {
461 .type = cpu_to_be16(ETH_P_PHONET),
462 .func = phonet_rcv,
463};
464
465static DEFINE_MUTEX(proto_tab_lock);
466
467int __init_or_module phonet_proto_register(unsigned int protocol,
468 struct phonet_protocol *pp)
469{
470 int err = 0;
471
472 if (protocol >= PHONET_NPROTO)
473 return -EINVAL;
474
475 err = proto_register(pp->prot, 1);
476 if (err)
477 return err;
478
479 mutex_lock(&proto_tab_lock);
480 if (proto_tab[protocol])
481 err = -EBUSY;
482 else
483 rcu_assign_pointer(proto_tab[protocol], pp);
484 mutex_unlock(&proto_tab_lock);
485
486 return err;
487}
488EXPORT_SYMBOL(phonet_proto_register);
489
490void phonet_proto_unregister(unsigned int protocol, struct phonet_protocol *pp)
491{
492 mutex_lock(&proto_tab_lock);
493 BUG_ON(proto_tab[protocol] != pp);
494 rcu_assign_pointer(proto_tab[protocol], NULL);
495 mutex_unlock(&proto_tab_lock);
496 synchronize_rcu();
497 proto_unregister(pp->prot);
498}
499EXPORT_SYMBOL(phonet_proto_unregister);
500
501/* Module registration */
502static int __init phonet_init(void)
503{
504 int err;
505
506 err = phonet_device_init();
507 if (err)
508 return err;
509
510 pn_sock_init();
511 err = sock_register(&phonet_proto_family);
512 if (err) {
513 printk(KERN_ALERT
514 "phonet protocol family initialization failed\n");
515 goto err_sock;
516 }
517
518 dev_add_pack(&phonet_packet_type);
519 phonet_sysctl_init();
520
521 err = isi_register();
522 if (err)
523 goto err;
524 return 0;
525
526err:
527 phonet_sysctl_exit();
528 sock_unregister(PF_PHONET);
529 dev_remove_pack(&phonet_packet_type);
530err_sock:
531 phonet_device_exit();
532 return err;
533}
534
535static void __exit phonet_exit(void)
536{
537 isi_unregister();
538 phonet_sysctl_exit();
539 sock_unregister(PF_PHONET);
540 dev_remove_pack(&phonet_packet_type);
541 phonet_device_exit();
542}
543
544module_init(phonet_init);
545module_exit(phonet_exit);
546MODULE_DESCRIPTION("Phonet protocol stack for Linux");
547MODULE_LICENSE("GPL");
548MODULE_ALIAS_NETPROTO(PF_PHONET);