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) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
  32 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
  33 {
  34         char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
  35         struct cn_msg *m = (struct cn_msg *)buf;
  36         struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
  37
  38         memset(buf, 0, sizeof(buf));
  39
  40         m->id.idx = CN_W1_IDX;
  41         m->id.val = CN_W1_VAL;
  42
  43         m->seq = dev->seq++;
  44         m->len = sizeof(struct w1_netlink_msg);
  45
  46         memcpy(w, msg, sizeof(struct w1_netlink_msg));
  47
  48         cn_netlink_send(m, 0, GFP_KERNEL);
  49 }
  50
  51 static void w1_send_slave(struct w1_master *dev, u64 rn)
  52 {
  53         struct cn_msg *msg = dev->priv;
  54         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  55         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  56         int avail;
  57
  58         avail = dev->priv_size - cmd->len;
  59
  60         if (avail > 8) {
  61                 u64 *data = (void *)(cmd + 1) + cmd->len;
  62
  63                 *data = rn;
  64                 cmd->len += 8;
  65                 hdr->len += 8;
  66                 msg->len += 8;
  67                 return;
  68         }
  69
  70         msg->ack++;
  71         cn_netlink_send(msg, 0, GFP_KERNEL);
  72
  73         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
  74         hdr->len = sizeof(struct w1_netlink_cmd);
  75         cmd->len = 0;
  76 }
  77
  78 static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
  79                 unsigned int avail)
  80 {
  81         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  82         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  83         int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;
  84
  85         dev->priv = msg;
  86         dev->priv_size = avail;
  87
  88         w1_search_devices(dev, search_type, w1_send_slave);
  89
  90         msg->ack = 0;
  91         cn_netlink_send(msg, 0, GFP_KERNEL);
  92
  93         dev->priv = NULL;
  94         dev->priv_size = 0;
  95
  96         return 0;
  97 }
  98
  99 static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
 100                 struct w1_netlink_cmd *cmd)
 101 {
 102         void *data;
 103         struct w1_netlink_msg *h;
 104         struct w1_netlink_cmd *c;
 105         struct cn_msg *cm;
 106         int err;
 107
 108         data = kzalloc(sizeof(struct cn_msg) +
 109                         sizeof(struct w1_netlink_msg) +
 110                         sizeof(struct w1_netlink_cmd) +
 111                         cmd->len, GFP_KERNEL);
 112         if (!data)
 113                 return -ENOMEM;
 114
 115         cm = (struct cn_msg *)(data);
 116         h = (struct w1_netlink_msg *)(cm + 1);
 117         c = (struct w1_netlink_cmd *)(h + 1);
 118
 119         memcpy(cm, msg, sizeof(struct cn_msg));
 120         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
 121         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
 122
 123         cm->ack = msg->seq+1;
 124         cm->len = sizeof(struct w1_netlink_msg) +
 125                 sizeof(struct w1_netlink_cmd) + cmd->len;
 126
 127         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
 128
 129         memcpy(c->data, cmd->data, c->len);
 130
 131         err = cn_netlink_send(cm, 0, GFP_KERNEL);
 132
 133         kfree(data);
 134
 135         return err;
 136 }
 137
 138 static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
 139                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 140 {
 141         int err = 0;
 142
 143         switch (cmd->cmd) {
 144         case W1_CMD_TOUCH:
 145                 w1_touch_block(dev, cmd->data, cmd->len);
 146                 w1_send_read_reply(msg, hdr, cmd);
 147                 break;
 148         case W1_CMD_READ:
 149                 w1_read_block(dev, cmd->data, cmd->len);
 150                 w1_send_read_reply(msg, hdr, cmd);
 151                 break;
 152         case W1_CMD_WRITE:
 153                 w1_write_block(dev, cmd->data, cmd->len);
 154                 break;
 155         default:
 156                 err = -EINVAL;
 157                 break;
 158         }
 159
 160         return err;
 161 }
 162
 163 static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
 164                 struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
 165 {
 166         int err = -EINVAL;
 167         struct cn_msg *msg;
 168         struct w1_netlink_msg *hdr;
 169         struct w1_netlink_cmd *cmd;
 170
 171         msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 172         if (!msg)
 173                 return -ENOMEM;
 174
 175         msg->id = req_msg->id;
 176         msg->seq = req_msg->seq;
 177         msg->ack = 0;
 178         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
 179
 180         hdr = (struct w1_netlink_msg *)(msg + 1);
 181         cmd = (struct w1_netlink_cmd *)(hdr + 1);
 182
 183         hdr->type = W1_MASTER_CMD;
 184         hdr->id = req_hdr->id;
 185         hdr->len = sizeof(struct w1_netlink_cmd);
 186
 187         cmd->cmd = req_cmd->cmd;
 188         cmd->len = 0;
 189
 190         switch (cmd->cmd) {
 191         case W1_CMD_SEARCH:
 192         case W1_CMD_ALARM_SEARCH:
 193                 err = w1_process_search_command(dev, msg,
 194                                 PAGE_SIZE - msg->len - sizeof(struct cn_msg));
 195                 break;
 196         case W1_CMD_READ:
 197         case W1_CMD_WRITE:
 198         case W1_CMD_TOUCH:
 199                 err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd);
 200                 break;
 201         case W1_CMD_RESET:
 202                 err = w1_reset_bus(dev);
 203                 break;
 204         default:
 205                 err = -EINVAL;
 206                 break;
 207         }
 208
 209         kfree(msg);
 210         return err;
 211 }
 212
 213 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 214                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 215 {
 216         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 217                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
 218                 sl->reg_num.crc, cmd->cmd, cmd->len);
 219
 220         return w1_process_command_io(sl->master, msg, hdr, cmd);
 221 }
 222
 223 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 224 {
 225         struct w1_master *m;
 226         struct cn_msg *cn;
 227         struct w1_netlink_msg *w;
 228         u32 *id;
 229
 230         if (mcmd->type != W1_LIST_MASTERS) {
 231                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 232                         __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 233                 return -EPROTO;
 234         }
 235
 236         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 237         if (!cn)
 238                 return -ENOMEM;
 239
 240         cn->id.idx = CN_W1_IDX;
 241         cn->id.val = CN_W1_VAL;
 242
 243         cn->seq = msg->seq;
 244         cn->ack = 1;
 245         cn->len = sizeof(struct w1_netlink_msg);
 246         w = (struct w1_netlink_msg *)(cn + 1);
 247
 248         w->type = W1_LIST_MASTERS;
 249         w->status = 0;
 250         w->len = 0;
 251         id = (u32 *)(w + 1);
 252
 253         mutex_lock(&w1_mlock);
 254         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 255                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 256                         cn_netlink_send(cn, 0, GFP_KERNEL);
 257                         cn->ack++;
 258                         cn->len = sizeof(struct w1_netlink_msg);
 259                         w->len = 0;
 260                         id = (u32 *)(w + 1);
 261                 }
 262
 263                 *id = m->id;
 264                 w->len += sizeof(*id);
 265                 cn->len += sizeof(*id);
 266                 id++;
 267         }
 268         cn->ack = 0;
 269         cn_netlink_send(cn, 0, GFP_KERNEL);
 270         mutex_unlock(&w1_mlock);
 271
 272         kfree(cn);
 273         return 0;
 274 }
 275
 276 static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
 277                 struct w1_netlink_cmd *rcmd, int error)
 278 {
 279         struct cn_msg *cmsg;
 280         struct w1_netlink_msg *msg;
 281         struct w1_netlink_cmd *cmd;
 282
 283         cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL);
 284         if (!cmsg)
 285                 return -ENOMEM;
 286
 287         msg = (struct w1_netlink_msg *)(cmsg + 1);
 288         cmd = (struct w1_netlink_cmd *)(msg + 1);
 289
 290         memcpy(cmsg, rcmsg, sizeof(*cmsg));
 291         cmsg->len = sizeof(*msg);
 292
 293         memcpy(msg, rmsg, sizeof(*msg));
 294         msg->len = 0;
 295         msg->status = (short)-error;
 296
 297         if (rcmd) {
 298                 memcpy(cmd, rcmd, sizeof(*cmd));
 299                 cmd->len = 0;
 300                 msg->len += sizeof(*cmd);
 301                 cmsg->len += sizeof(*cmd);
 302         }
 303
 304         error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
 305         kfree(cmsg);
 306
 307         return error;
 308 }
 309
 310 static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 311 {
 312         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 313         struct w1_netlink_cmd *cmd;
 314         struct w1_slave *sl;
 315         struct w1_master *dev;
 316         int err = 0;
 317
 318         while (msg->len && !err) {
 319                 struct w1_reg_num id;
 320                 u16 mlen = m->len;
 321                 u8 *cmd_data = m->data;
 322
 323                 dev = NULL;
 324                 sl = NULL;
 325                 cmd = NULL;
 326
 327                 memcpy(&id, m->id.id, sizeof(id));
 328 #if 0
 329                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 330                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 331 #endif
 332                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 333                         err = -E2BIG;
 334                         break;
 335                 }
 336
 337                 if (m->type == W1_MASTER_CMD) {
 338                         dev = w1_search_master_id(m->id.mst.id);
 339                 } else if (m->type == W1_SLAVE_CMD) {
 340                         sl = w1_search_slave(&id);
 341                         if (sl)
 342                                 dev = sl->master;
 343                 } else {
 344                         err = w1_process_command_root(msg, m);
 345                         goto out_cont;
 346                 }
 347
 348                 if (!dev) {
 349                         err = -ENODEV;
 350                         goto out_cont;
 351                 }
 352
 353                 err = 0;
 354                 if (!mlen)
 355                         goto out_cont;
 356
 357                 mutex_lock(&dev->mutex);
 358
 359                 if (sl && w1_reset_select_slave(sl)) {
 360                         err = -ENODEV;
 361                         goto out_up;
 362                 }
 363
 364                 while (mlen) {
 365                         cmd = (struct w1_netlink_cmd *)cmd_data;
 366
 367                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 368                                 err = -E2BIG;
 369                                 break;
 370                         }
 371
 372                         if (sl)
 373                                 err = w1_process_command_slave(sl, msg, m, cmd);
 374                         else
 375                                 err = w1_process_command_master(dev, msg, m, cmd);
 376
 377                         w1_netlink_send_error(msg, m, cmd, err);
 378                         err = 0;
 379
 380                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 381                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 382                 }
 383 out_up:
 384                 atomic_dec(&dev->refcnt);
 385                 if (sl)
 386                         atomic_dec(&sl->refcnt);
 387                 mutex_unlock(&dev->mutex);
 388 out_cont:
 389                 if (!cmd || err)
 390                         w1_netlink_send_error(msg, m, cmd, err);
 391                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 392                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 393
 394                 /*
 395                  * Let's allow requests for nonexisting devices.
 396                  */
 397                 if (err == -ENODEV)
 398                         err = 0;
 399         }
 400 }
 401
 402 int w1_init_netlink(void)
 403 {
 404         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 405
 406         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 407 }
 408
 409 void w1_fini_netlink(void)
 410 {
 411         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 412
 413         cn_del_callback(&w1_id);
 414 }
 415 #else
 416 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 417 {
 418 }
 419
 420 int w1_init_netlink(void)
 421 {
 422         return 0;
 423 }
 424
 425 void w1_fini_netlink(void)
 426 {
 427 }
 428 #endif