Commit | Line | Data |
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4b07b3f6 RDC |
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 <asm/unaligned.h> | |
29 | #include <net/sock.h> | |
30 | ||
31 | #include <linux/if_phonet.h> | |
32 | #include <linux/phonet.h> | |
33 | #include <net/phonet/phonet.h> | |
f8ff6028 | 34 | #include <net/phonet/pn_dev.h> |
4b07b3f6 RDC |
35 | |
36 | static struct net_proto_family phonet_proto_family; | |
37 | static struct phonet_protocol *phonet_proto_get(int protocol); | |
38 | static inline void phonet_proto_put(struct phonet_protocol *pp); | |
39 | ||
40 | /* protocol family functions */ | |
41 | ||
42 | static int pn_socket_create(struct net *net, struct socket *sock, int protocol) | |
43 | { | |
ba113a94 RDC |
44 | struct sock *sk; |
45 | struct pn_sock *pn; | |
4b07b3f6 RDC |
46 | struct phonet_protocol *pnp; |
47 | int err; | |
48 | ||
49 | if (net != &init_net) | |
50 | return -EAFNOSUPPORT; | |
51 | ||
52 | if (!capable(CAP_SYS_ADMIN)) | |
53 | return -EPERM; | |
54 | ||
55 | if (protocol == 0) { | |
56 | /* Default protocol selection */ | |
57 | switch (sock->type) { | |
58 | case SOCK_DGRAM: | |
59 | protocol = PN_PROTO_PHONET; | |
60 | break; | |
9641458d RDC |
61 | case SOCK_SEQPACKET: |
62 | protocol = PN_PROTO_PIPE; | |
63 | break; | |
4b07b3f6 RDC |
64 | default: |
65 | return -EPROTONOSUPPORT; | |
66 | } | |
67 | } | |
68 | ||
69 | pnp = phonet_proto_get(protocol); | |
25532824 RDC |
70 | #ifdef CONFIG_KMOD |
71 | if (pnp == NULL && | |
72 | request_module("net-pf-%d-proto-%d", PF_PHONET, protocol) == 0) | |
73 | pnp = phonet_proto_get(protocol); | |
74 | #endif | |
4b07b3f6 RDC |
75 | if (pnp == NULL) |
76 | return -EPROTONOSUPPORT; | |
77 | if (sock->type != pnp->sock_type) { | |
78 | err = -EPROTONOSUPPORT; | |
79 | goto out; | |
80 | } | |
81 | ||
ba113a94 RDC |
82 | sk = sk_alloc(net, PF_PHONET, GFP_KERNEL, pnp->prot); |
83 | if (sk == NULL) { | |
84 | err = -ENOMEM; | |
85 | goto out; | |
86 | } | |
87 | ||
88 | sock_init_data(sock, sk); | |
89 | sock->state = SS_UNCONNECTED; | |
90 | sock->ops = pnp->ops; | |
91 | sk->sk_backlog_rcv = sk->sk_prot->backlog_rcv; | |
92 | sk->sk_protocol = protocol; | |
93 | pn = pn_sk(sk); | |
94 | pn->sobject = 0; | |
95 | pn->resource = 0; | |
96 | sk->sk_prot->init(sk); | |
97 | err = 0; | |
4b07b3f6 RDC |
98 | |
99 | out: | |
100 | phonet_proto_put(pnp); | |
101 | return err; | |
102 | } | |
103 | ||
104 | static struct net_proto_family phonet_proto_family = { | |
25532824 | 105 | .family = PF_PHONET, |
4b07b3f6 RDC |
106 | .create = pn_socket_create, |
107 | .owner = THIS_MODULE, | |
108 | }; | |
109 | ||
5f77076d RDC |
110 | /* Phonet device header operations */ |
111 | static int pn_header_create(struct sk_buff *skb, struct net_device *dev, | |
112 | unsigned short type, const void *daddr, | |
113 | const void *saddr, unsigned len) | |
114 | { | |
115 | u8 *media = skb_push(skb, 1); | |
116 | ||
117 | if (type != ETH_P_PHONET) | |
118 | return -1; | |
119 | ||
120 | if (!saddr) | |
121 | saddr = dev->dev_addr; | |
122 | *media = *(const u8 *)saddr; | |
123 | return 1; | |
124 | } | |
125 | ||
126 | static int pn_header_parse(const struct sk_buff *skb, unsigned char *haddr) | |
127 | { | |
128 | const u8 *media = skb_mac_header(skb); | |
129 | *haddr = *media; | |
130 | return 1; | |
131 | } | |
132 | ||
133 | struct header_ops phonet_header_ops = { | |
134 | .create = pn_header_create, | |
135 | .parse = pn_header_parse, | |
136 | }; | |
137 | EXPORT_SYMBOL(phonet_header_ops); | |
138 | ||
107d0d9b RDC |
139 | /* |
140 | * Prepends an ISI header and sends a datagram. | |
141 | */ | |
142 | static int pn_send(struct sk_buff *skb, struct net_device *dev, | |
be0c52bf | 143 | u16 dst, u16 src, u8 res, u8 irq) |
107d0d9b RDC |
144 | { |
145 | struct phonethdr *ph; | |
146 | int err; | |
147 | ||
148 | if (skb->len + 2 > 0xffff) { | |
149 | /* Phonet length field would overflow */ | |
150 | err = -EMSGSIZE; | |
151 | goto drop; | |
152 | } | |
153 | ||
154 | skb_reset_transport_header(skb); | |
155 | WARN_ON(skb_headroom(skb) & 1); /* HW assumes word alignment */ | |
156 | skb_push(skb, sizeof(struct phonethdr)); | |
157 | skb_reset_network_header(skb); | |
158 | ph = pn_hdr(skb); | |
159 | ph->pn_rdev = pn_dev(dst); | |
160 | ph->pn_sdev = pn_dev(src); | |
161 | ph->pn_res = res; | |
162 | ph->pn_length = __cpu_to_be16(skb->len + 2 - sizeof(*ph)); | |
163 | ph->pn_robj = pn_obj(dst); | |
164 | ph->pn_sobj = pn_obj(src); | |
165 | ||
166 | skb->protocol = htons(ETH_P_PHONET); | |
167 | skb->priority = 0; | |
168 | skb->dev = dev; | |
169 | ||
170 | if (pn_addr(src) == pn_addr(dst)) { | |
171 | skb_reset_mac_header(skb); | |
172 | skb->pkt_type = PACKET_LOOPBACK; | |
173 | skb_orphan(skb); | |
be0c52bf RDC |
174 | if (irq) |
175 | netif_rx(skb); | |
176 | else | |
177 | netif_rx_ni(skb); | |
107d0d9b RDC |
178 | err = 0; |
179 | } else { | |
180 | err = dev_hard_header(skb, dev, ntohs(skb->protocol), | |
181 | NULL, NULL, skb->len); | |
182 | if (err < 0) { | |
183 | err = -EHOSTUNREACH; | |
184 | goto drop; | |
185 | } | |
186 | err = dev_queue_xmit(skb); | |
187 | } | |
188 | ||
189 | return err; | |
190 | drop: | |
191 | kfree_skb(skb); | |
192 | return err; | |
193 | } | |
194 | ||
be0c52bf RDC |
195 | static int pn_raw_send(const void *data, int len, struct net_device *dev, |
196 | u16 dst, u16 src, u8 res) | |
197 | { | |
198 | struct sk_buff *skb = alloc_skb(MAX_PHONET_HEADER + len, GFP_ATOMIC); | |
199 | if (skb == NULL) | |
200 | return -ENOMEM; | |
201 | ||
202 | skb_reserve(skb, MAX_PHONET_HEADER); | |
203 | __skb_put(skb, len); | |
204 | skb_copy_to_linear_data(skb, data, len); | |
205 | return pn_send(skb, dev, dst, src, res, 1); | |
206 | } | |
207 | ||
107d0d9b RDC |
208 | /* |
209 | * Create a Phonet header for the skb and send it out. Returns | |
210 | * non-zero error code if failed. The skb is freed then. | |
211 | */ | |
212 | int pn_skb_send(struct sock *sk, struct sk_buff *skb, | |
213 | const struct sockaddr_pn *target) | |
214 | { | |
215 | struct net_device *dev; | |
216 | struct pn_sock *pn = pn_sk(sk); | |
217 | int err; | |
218 | u16 src; | |
219 | u8 daddr = pn_sockaddr_get_addr(target), saddr = PN_NO_ADDR; | |
220 | ||
221 | err = -EHOSTUNREACH; | |
222 | if (sk->sk_bound_dev_if) | |
223 | dev = dev_get_by_index(sock_net(sk), sk->sk_bound_dev_if); | |
224 | else | |
225 | dev = phonet_device_get(sock_net(sk)); | |
226 | if (!dev || !(dev->flags & IFF_UP)) | |
227 | goto drop; | |
228 | ||
229 | saddr = phonet_address_get(dev, daddr); | |
230 | if (saddr == PN_NO_ADDR) | |
231 | goto drop; | |
232 | ||
233 | src = pn->sobject; | |
234 | if (!pn_addr(src)) | |
235 | src = pn_object(saddr, pn_obj(src)); | |
236 | ||
237 | err = pn_send(skb, dev, pn_sockaddr_get_object(target), | |
be0c52bf | 238 | src, pn_sockaddr_get_resource(target), 0); |
107d0d9b RDC |
239 | dev_put(dev); |
240 | return err; | |
241 | ||
242 | drop: | |
243 | kfree_skb(skb); | |
244 | if (dev) | |
245 | dev_put(dev); | |
246 | return err; | |
247 | } | |
248 | EXPORT_SYMBOL(pn_skb_send); | |
249 | ||
be0c52bf RDC |
250 | /* Do not send an error message in response to an error message */ |
251 | static inline int can_respond(struct sk_buff *skb) | |
252 | { | |
253 | const struct phonethdr *ph; | |
254 | const struct phonetmsg *pm; | |
255 | u8 submsg_id; | |
256 | ||
257 | if (!pskb_may_pull(skb, 3)) | |
258 | return 0; | |
259 | ||
260 | ph = pn_hdr(skb); | |
261 | if (phonet_address_get(skb->dev, ph->pn_rdev) != ph->pn_rdev) | |
262 | return 0; /* we are not the destination */ | |
263 | if (ph->pn_res == PN_PREFIX && !pskb_may_pull(skb, 5)) | |
264 | return 0; | |
265 | ||
266 | ph = pn_hdr(skb); /* re-acquires the pointer */ | |
267 | pm = pn_msg(skb); | |
268 | if (pm->pn_msg_id != PN_COMMON_MESSAGE) | |
269 | return 1; | |
270 | submsg_id = (ph->pn_res == PN_PREFIX) | |
271 | ? pm->pn_e_submsg_id : pm->pn_submsg_id; | |
272 | if (submsg_id != PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP && | |
273 | pm->pn_e_submsg_id != PN_COMM_SERVICE_NOT_IDENTIFIED_RESP) | |
274 | return 1; | |
275 | return 0; | |
276 | } | |
277 | ||
278 | static int send_obj_unreachable(struct sk_buff *rskb) | |
279 | { | |
280 | const struct phonethdr *oph = pn_hdr(rskb); | |
281 | const struct phonetmsg *opm = pn_msg(rskb); | |
282 | struct phonetmsg resp; | |
283 | ||
284 | memset(&resp, 0, sizeof(resp)); | |
285 | resp.pn_trans_id = opm->pn_trans_id; | |
286 | resp.pn_msg_id = PN_COMMON_MESSAGE; | |
287 | if (oph->pn_res == PN_PREFIX) { | |
288 | resp.pn_e_res_id = opm->pn_e_res_id; | |
289 | resp.pn_e_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP; | |
290 | resp.pn_e_orig_msg_id = opm->pn_msg_id; | |
291 | resp.pn_e_status = 0; | |
292 | } else { | |
293 | resp.pn_submsg_id = PN_COMM_ISA_ENTITY_NOT_REACHABLE_RESP; | |
294 | resp.pn_orig_msg_id = opm->pn_msg_id; | |
295 | resp.pn_status = 0; | |
296 | } | |
297 | return pn_raw_send(&resp, sizeof(resp), rskb->dev, | |
298 | pn_object(oph->pn_sdev, oph->pn_sobj), | |
299 | pn_object(oph->pn_rdev, oph->pn_robj), | |
300 | oph->pn_res); | |
301 | } | |
302 | ||
303 | static int send_reset_indications(struct sk_buff *rskb) | |
304 | { | |
305 | struct phonethdr *oph = pn_hdr(rskb); | |
306 | static const u8 data[4] = { | |
307 | 0x00 /* trans ID */, 0x10 /* subscribe msg */, | |
308 | 0x00 /* subscription count */, 0x00 /* dummy */ | |
309 | }; | |
310 | ||
311 | return pn_raw_send(data, sizeof(data), rskb->dev, | |
312 | pn_object(oph->pn_sdev, 0x00), | |
313 | pn_object(oph->pn_rdev, oph->pn_robj), 0x10); | |
314 | } | |
315 | ||
316 | ||
4b07b3f6 RDC |
317 | /* packet type functions */ |
318 | ||
319 | /* | |
320 | * Stuff received packets to associated sockets. | |
321 | * On error, returns non-zero and releases the skb. | |
322 | */ | |
323 | static int phonet_rcv(struct sk_buff *skb, struct net_device *dev, | |
324 | struct packet_type *pkttype, | |
325 | struct net_device *orig_dev) | |
326 | { | |
327 | struct phonethdr *ph; | |
ba113a94 | 328 | struct sock *sk; |
4b07b3f6 RDC |
329 | struct sockaddr_pn sa; |
330 | u16 len; | |
331 | ||
332 | if (dev_net(dev) != &init_net) | |
333 | goto out; | |
334 | ||
335 | /* check we have at least a full Phonet header */ | |
336 | if (!pskb_pull(skb, sizeof(struct phonethdr))) | |
337 | goto out; | |
338 | ||
339 | /* check that the advertised length is correct */ | |
340 | ph = pn_hdr(skb); | |
341 | len = get_unaligned_be16(&ph->pn_length); | |
342 | if (len < 2) | |
343 | goto out; | |
344 | len -= 2; | |
345 | if ((len > skb->len) || pskb_trim(skb, len)) | |
346 | goto out; | |
347 | skb_reset_transport_header(skb); | |
348 | ||
349 | pn_skb_get_dst_sockaddr(skb, &sa); | |
350 | if (pn_sockaddr_get_addr(&sa) == 0) | |
351 | goto out; /* currently, we cannot be device 0 */ | |
352 | ||
ba113a94 | 353 | sk = pn_find_sock_by_sa(&sa); |
be0c52bf RDC |
354 | if (sk == NULL) { |
355 | if (can_respond(skb)) { | |
356 | send_obj_unreachable(skb); | |
357 | send_reset_indications(skb); | |
358 | } | |
ba113a94 | 359 | goto out; |
be0c52bf | 360 | } |
ba113a94 RDC |
361 | |
362 | /* Push data to the socket (or other sockets connected to it). */ | |
363 | return sk_receive_skb(sk, skb, 0); | |
4b07b3f6 RDC |
364 | |
365 | out: | |
366 | kfree_skb(skb); | |
367 | return NET_RX_DROP; | |
368 | } | |
369 | ||
370 | static struct packet_type phonet_packet_type = { | |
371 | .type = __constant_htons(ETH_P_PHONET), | |
372 | .dev = NULL, | |
373 | .func = phonet_rcv, | |
374 | }; | |
375 | ||
376 | /* Transport protocol registration */ | |
377 | static struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; | |
378 | static DEFINE_SPINLOCK(proto_tab_lock); | |
379 | ||
380 | int __init_or_module phonet_proto_register(int protocol, | |
381 | struct phonet_protocol *pp) | |
382 | { | |
383 | int err = 0; | |
384 | ||
385 | if (protocol >= PHONET_NPROTO) | |
386 | return -EINVAL; | |
387 | ||
388 | err = proto_register(pp->prot, 1); | |
389 | if (err) | |
390 | return err; | |
391 | ||
392 | spin_lock(&proto_tab_lock); | |
393 | if (proto_tab[protocol]) | |
394 | err = -EBUSY; | |
395 | else | |
396 | proto_tab[protocol] = pp; | |
397 | spin_unlock(&proto_tab_lock); | |
398 | ||
399 | return err; | |
400 | } | |
401 | EXPORT_SYMBOL(phonet_proto_register); | |
402 | ||
403 | void phonet_proto_unregister(int protocol, struct phonet_protocol *pp) | |
404 | { | |
405 | spin_lock(&proto_tab_lock); | |
406 | BUG_ON(proto_tab[protocol] != pp); | |
407 | proto_tab[protocol] = NULL; | |
408 | spin_unlock(&proto_tab_lock); | |
409 | proto_unregister(pp->prot); | |
410 | } | |
411 | EXPORT_SYMBOL(phonet_proto_unregister); | |
412 | ||
413 | static struct phonet_protocol *phonet_proto_get(int protocol) | |
414 | { | |
415 | struct phonet_protocol *pp; | |
416 | ||
417 | if (protocol >= PHONET_NPROTO) | |
418 | return NULL; | |
419 | ||
420 | spin_lock(&proto_tab_lock); | |
421 | pp = proto_tab[protocol]; | |
422 | if (pp && !try_module_get(pp->prot->owner)) | |
423 | pp = NULL; | |
424 | spin_unlock(&proto_tab_lock); | |
425 | ||
426 | return pp; | |
427 | } | |
428 | ||
429 | static inline void phonet_proto_put(struct phonet_protocol *pp) | |
430 | { | |
431 | module_put(pp->prot->owner); | |
432 | } | |
433 | ||
434 | /* Module registration */ | |
435 | static int __init phonet_init(void) | |
436 | { | |
437 | int err; | |
438 | ||
439 | err = sock_register(&phonet_proto_family); | |
440 | if (err) { | |
441 | printk(KERN_ALERT | |
442 | "phonet protocol family initialization failed\n"); | |
443 | return err; | |
444 | } | |
445 | ||
f8ff6028 | 446 | phonet_device_init(); |
4b07b3f6 | 447 | dev_add_pack(&phonet_packet_type); |
8fb39740 | 448 | phonet_netlink_register(); |
87ab4e20 | 449 | phonet_sysctl_init(); |
107d0d9b RDC |
450 | |
451 | err = isi_register(); | |
452 | if (err) | |
453 | goto err; | |
4b07b3f6 | 454 | return 0; |
107d0d9b RDC |
455 | |
456 | err: | |
87ab4e20 | 457 | phonet_sysctl_exit(); |
25532824 | 458 | sock_unregister(PF_PHONET); |
107d0d9b RDC |
459 | dev_remove_pack(&phonet_packet_type); |
460 | phonet_device_exit(); | |
461 | return err; | |
4b07b3f6 RDC |
462 | } |
463 | ||
464 | static void __exit phonet_exit(void) | |
465 | { | |
107d0d9b | 466 | isi_unregister(); |
87ab4e20 | 467 | phonet_sysctl_exit(); |
25532824 | 468 | sock_unregister(PF_PHONET); |
4b07b3f6 | 469 | dev_remove_pack(&phonet_packet_type); |
f8ff6028 | 470 | phonet_device_exit(); |
4b07b3f6 RDC |
471 | } |
472 | ||
473 | module_init(phonet_init); | |
474 | module_exit(phonet_exit); | |
475 | MODULE_DESCRIPTION("Phonet protocol stack for Linux"); | |
476 | MODULE_LICENSE("GPL"); | |
25532824 | 477 | MODULE_ALIAS_NETPROTO(PF_PHONET); |