release/src-rt-6.x.4708/linux/linux-2.6.36/drivers/w1/w1_netlink.c

   1 /*
   2  * w1_netlink.c
   3  *
   4  * Copyright (c) 2003 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/slab.h>
  23 #include <linux/skbuff.h>
  24 #include <linux/netlink.h>
  25 #include <linux/connector.h>
  26
  27 #include "w1.h"
  28 #include "w1_log.h"
  29 #include "w1_netlink.h"
  30
  31 #if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || \
  32         (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
  33 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
  34 {
  35         char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
  36         struct cn_msg *m = (struct cn_msg *)buf;
  37         struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
  38
  39         memset(buf, 0, sizeof(buf));
  40
  41         m->id.idx = CN_W1_IDX;
  42         m->id.val = CN_W1_VAL;
  43
  44         m->seq = dev->seq++;
  45         m->len = sizeof(struct w1_netlink_msg);
  46
  47         memcpy(w, msg, sizeof(struct w1_netlink_msg));
  48
  49         cn_netlink_send(m, 0, GFP_KERNEL);
  50 }
  51
  52 static void w1_send_slave(struct w1_master *dev, u64 rn)
  53 {
  54         struct cn_msg *msg = dev->priv;
  55         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  56         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  57         int avail;
  58
  59         avail = dev->priv_size - cmd->len;
  60
  61         if (avail > 8) {
  62                 u64 *data = (void *)(cmd + 1) + cmd->len;
  63
  64                 *data = rn;
  65                 cmd->len += 8;
  66                 hdr->len += 8;
  67                 msg->len += 8;
  68                 return;
  69         }
  70
  71         msg->ack++;
  72         cn_netlink_send(msg, 0, GFP_KERNEL);
  73
  74         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
  75         hdr->len = sizeof(struct w1_netlink_cmd);
  76         cmd->len = 0;
  77 }
  78
  79 static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
  80                 unsigned int avail)
  81 {
  82         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  83         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  84         int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;
  85
  86         dev->priv = msg;
  87         dev->priv_size = avail;
  88
  89         w1_search_devices(dev, search_type, w1_send_slave);
  90
  91         msg->ack = 0;
  92         cn_netlink_send(msg, 0, GFP_KERNEL);
  93
  94         dev->priv = NULL;
  95         dev->priv_size = 0;
  96
  97         return 0;
  98 }
  99
 100 static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
 101                 struct w1_netlink_cmd *cmd)
 102 {
 103         void *data;
 104         struct w1_netlink_msg *h;
 105         struct w1_netlink_cmd *c;
 106         struct cn_msg *cm;
 107         int err;
 108
 109         data = kzalloc(sizeof(struct cn_msg) +
 110                         sizeof(struct w1_netlink_msg) +
 111                         sizeof(struct w1_netlink_cmd) +
 112                         cmd->len, GFP_KERNEL);
 113         if (!data)
 114                 return -ENOMEM;
 115
 116         cm = (struct cn_msg *)(data);
 117         h = (struct w1_netlink_msg *)(cm + 1);
 118         c = (struct w1_netlink_cmd *)(h + 1);
 119
 120         memcpy(cm, msg, sizeof(struct cn_msg));
 121         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
 122         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
 123
 124         cm->ack = msg->seq+1;
 125         cm->len = sizeof(struct w1_netlink_msg) +
 126                 sizeof(struct w1_netlink_cmd) + cmd->len;
 127
 128         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
 129
 130         memcpy(c->data, cmd->data, c->len);
 131
 132         err = cn_netlink_send(cm, 0, GFP_KERNEL);
 133
 134         kfree(data);
 135
 136         return err;
 137 }
 138
 139 static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
 140                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 141 {
 142         int err = 0;
 143
 144         switch (cmd->cmd) {
 145         case W1_CMD_TOUCH:
 146                 w1_touch_block(dev, cmd->data, cmd->len);
 147                 w1_send_read_reply(msg, hdr, cmd);
 148                 break;
 149         case W1_CMD_READ:
 150                 w1_read_block(dev, cmd->data, cmd->len);
 151                 w1_send_read_reply(msg, hdr, cmd);
 152                 break;
 153         case W1_CMD_WRITE:
 154                 w1_write_block(dev, cmd->data, cmd->len);
 155                 break;
 156         default:
 157                 err = -EINVAL;
 158                 break;
 159         }
 160
 161         return err;
 162 }
 163
 164 static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
 165                 struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
 166 {
 167         int err = -EINVAL;
 168         struct cn_msg *msg;
 169         struct w1_netlink_msg *hdr;
 170         struct w1_netlink_cmd *cmd;
 171
 172         msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 173         if (!msg)
 174                 return -ENOMEM;
 175
 176         msg->id = req_msg->id;
 177         msg->seq = req_msg->seq;
 178         msg->ack = 0;
 179         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
 180
 181         hdr = (struct w1_netlink_msg *)(msg + 1);
 182         cmd = (struct w1_netlink_cmd *)(hdr + 1);
 183
 184         hdr->type = W1_MASTER_CMD;
 185         hdr->id = req_hdr->id;
 186         hdr->len = sizeof(struct w1_netlink_cmd);
 187
 188         cmd->cmd = req_cmd->cmd;
 189         cmd->len = 0;
 190
 191         switch (cmd->cmd) {
 192         case W1_CMD_SEARCH:
 193         case W1_CMD_ALARM_SEARCH:
 194                 err = w1_process_search_command(dev, msg,
 195                                 PAGE_SIZE - msg->len - sizeof(struct cn_msg));
 196                 break;
 197         case W1_CMD_READ:
 198         case W1_CMD_WRITE:
 199         case W1_CMD_TOUCH:
 200                 err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd);
 201                 break;
 202         case W1_CMD_RESET:
 203                 err = w1_reset_bus(dev);
 204                 break;
 205         default:
 206                 err = -EINVAL;
 207                 break;
 208         }
 209
 210         kfree(msg);
 211         return err;
 212 }
 213
 214 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 215                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 216 {
 217         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 218                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
 219                 sl->reg_num.crc, cmd->cmd, cmd->len);
 220
 221         return w1_process_command_io(sl->master, msg, hdr, cmd);
 222 }
 223
 224 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 225 {
 226         struct w1_master *m;
 227         struct cn_msg *cn;
 228         struct w1_netlink_msg *w;
 229         u32 *id;
 230
 231         if (mcmd->type != W1_LIST_MASTERS) {
 232                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 233                         __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 234                 return -EPROTO;
 235         }
 236
 237         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 238         if (!cn)
 239                 return -ENOMEM;
 240
 241         cn->id.idx = CN_W1_IDX;
 242         cn->id.val = CN_W1_VAL;
 243
 244         cn->seq = msg->seq;
 245         cn->ack = 1;
 246         cn->len = sizeof(struct w1_netlink_msg);
 247         w = (struct w1_netlink_msg *)(cn + 1);
 248
 249         w->type = W1_LIST_MASTERS;
 250         w->status = 0;
 251         w->len = 0;
 252         id = (u32 *)(w + 1);
 253
 254         mutex_lock(&w1_mlock);
 255         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 256                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 257                         cn_netlink_send(cn, 0, GFP_KERNEL);
 258                         cn->ack++;
 259                         cn->len = sizeof(struct w1_netlink_msg);
 260                         w->len = 0;
 261                         id = (u32 *)(w + 1);
 262                 }
 263
 264                 *id = m->id;
 265                 w->len += sizeof(*id);
 266                 cn->len += sizeof(*id);
 267                 id++;
 268         }
 269         cn->ack = 0;
 270         cn_netlink_send(cn, 0, GFP_KERNEL);
 271         mutex_unlock(&w1_mlock);
 272
 273         kfree(cn);
 274         return 0;
 275 }
 276
 277 static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
 278                 struct w1_netlink_cmd *rcmd, int error)
 279 {
 280         struct cn_msg *cmsg;
 281         struct w1_netlink_msg *msg;
 282         struct w1_netlink_cmd *cmd;
 283
 284         cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL);
 285         if (!cmsg)
 286                 return -ENOMEM;
 287
 288         msg = (struct w1_netlink_msg *)(cmsg + 1);
 289         cmd = (struct w1_netlink_cmd *)(msg + 1);
 290
 291         memcpy(cmsg, rcmsg, sizeof(*cmsg));
 292         cmsg->len = sizeof(*msg);
 293
 294         memcpy(msg, rmsg, sizeof(*msg));
 295         msg->len = 0;
 296         msg->status = (short)-error;
 297
 298         if (rcmd) {
 299                 memcpy(cmd, rcmd, sizeof(*cmd));
 300                 cmd->len = 0;
 301                 msg->len += sizeof(*cmd);
 302                 cmsg->len += sizeof(*cmd);
 303         }
 304
 305         error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
 306         kfree(cmsg);
 307
 308         return error;
 309 }
 310
 311 static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 312 {
 313         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 314         struct w1_netlink_cmd *cmd;
 315         struct w1_slave *sl;
 316         struct w1_master *dev;
 317         int err = 0;
 318
 319         while (msg->len && !err) {
 320                 struct w1_reg_num id;
 321                 u16 mlen = m->len;
 322                 u8 *cmd_data = m->data;
 323
 324                 dev = NULL;
 325                 sl = NULL;
 326                 cmd = NULL;
 327
 328                 memcpy(&id, m->id.id, sizeof(id));
 329                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 330                         err = -E2BIG;
 331                         break;
 332                 }
 333
 334                 if (m->type == W1_MASTER_CMD) {
 335                         dev = w1_search_master_id(m->id.mst.id);
 336                 } else if (m->type == W1_SLAVE_CMD) {
 337                         sl = w1_search_slave(&id);
 338                         if (sl)
 339                                 dev = sl->master;
 340                 } else {
 341                         err = w1_process_command_root(msg, m);
 342                         goto out_cont;
 343                 }
 344
 345                 if (!dev) {
 346                         err = -ENODEV;
 347                         goto out_cont;
 348                 }
 349
 350                 err = 0;
 351                 if (!mlen)
 352                         goto out_cont;
 353
 354                 mutex_lock(&dev->mutex);
 355
 356                 if (sl && w1_reset_select_slave(sl)) {
 357                         err = -ENODEV;
 358                         goto out_up;
 359                 }
 360
 361                 while (mlen) {
 362                         cmd = (struct w1_netlink_cmd *)cmd_data;
 363
 364                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 365                                 err = -E2BIG;
 366                                 break;
 367                         }
 368
 369                         if (sl)
 370                                 err = w1_process_command_slave(sl, msg, m, cmd);
 371                         else
 372                                 err = w1_process_command_master(dev, msg, m, cmd);
 373
 374                         w1_netlink_send_error(msg, m, cmd, err);
 375                         err = 0;
 376
 377                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 378                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 379                 }
 380 out_up:
 381                 atomic_dec(&dev->refcnt);
 382                 if (sl)
 383                         atomic_dec(&sl->refcnt);
 384                 mutex_unlock(&dev->mutex);
 385 out_cont:
 386                 if (!cmd || err)
 387                         w1_netlink_send_error(msg, m, cmd, err);
 388                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 389                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 390
 391                 /*
 392                  * Let's allow requests for nonexisting devices.
 393                  */
 394                 if (err == -ENODEV)
 395                         err = 0;
 396         }
 397 }
 398
 399 int w1_init_netlink(void)
 400 {
 401         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 402
 403         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 404 }
 405
 406 void w1_fini_netlink(void)
 407 {
 408         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 409
 410         cn_del_callback(&w1_id);
 411 }
 412 #else
 413 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 414 {
 415 }
 416
 417 int w1_init_netlink(void)
 418 {
 419         return 0;
 420 }
 421
 422 void w1_fini_netlink(void)
 423 {
 424 }
 425 #endif