drivers/w1/w1_netlink.c

   1 /*
   2  * w1_netlink.c
   3  *
   4  * Copyright (c) 2003 Evgeniy Polyakov <zbr@ioremap.net>
   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         u64 *data;
  58
  59         /* update kernel slave list */
  60         w1_slave_found(dev, rn);
  61
  62         avail = dev->priv_size - cmd->len;
  63
  64         if (avail < 8) {
  65                 msg->ack++;
  66                 cn_netlink_send(msg, 0, GFP_KERNEL);
  67
  68                 msg->len = sizeof(struct w1_netlink_msg) +
  69                         sizeof(struct w1_netlink_cmd);
  70                 hdr->len = sizeof(struct w1_netlink_cmd);
  71                 cmd->len = 0;
  72         }
  73
  74         data = (void *)(cmd + 1) + cmd->len;
  75
  76         *data = rn;
  77         cmd->len += 8;
  78         hdr->len += 8;
  79         msg->len += 8;
  80 }
  81
  82 static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
  83                 unsigned int avail)
  84 {
  85         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  86         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  87         int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;
  88
  89         dev->priv = msg;
  90         dev->priv_size = avail;
  91
  92         w1_search_process_cb(dev, search_type, w1_send_slave);
  93
  94         msg->ack = 0;
  95         cn_netlink_send(msg, 0, GFP_KERNEL);
  96
  97         dev->priv = NULL;
  98         dev->priv_size = 0;
  99
 100         return 0;
 101 }
 102
 103 static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
 104                 struct w1_netlink_cmd *cmd)
 105 {
 106         void *data;
 107         struct w1_netlink_msg *h;
 108         struct w1_netlink_cmd *c;
 109         struct cn_msg *cm;
 110         int err;
 111
 112         data = kzalloc(sizeof(struct cn_msg) +
 113                         sizeof(struct w1_netlink_msg) +
 114                         sizeof(struct w1_netlink_cmd) +
 115                         cmd->len, GFP_KERNEL);
 116         if (!data)
 117                 return -ENOMEM;
 118
 119         cm = (struct cn_msg *)(data);
 120         h = (struct w1_netlink_msg *)(cm + 1);
 121         c = (struct w1_netlink_cmd *)(h + 1);
 122
 123         memcpy(cm, msg, sizeof(struct cn_msg));
 124         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
 125         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
 126
 127         cm->ack = msg->seq+1;
 128         cm->len = sizeof(struct w1_netlink_msg) +
 129                 sizeof(struct w1_netlink_cmd) + cmd->len;
 130
 131         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
 132
 133         memcpy(c->data, cmd->data, c->len);
 134
 135         err = cn_netlink_send(cm, 0, GFP_KERNEL);
 136
 137         kfree(data);
 138
 139         return err;
 140 }
 141
 142 static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
 143                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 144 {
 145         int err = 0;
 146
 147         switch (cmd->cmd) {
 148         case W1_CMD_TOUCH:
 149                 w1_touch_block(dev, cmd->data, cmd->len);
 150                 w1_send_read_reply(msg, hdr, cmd);
 151                 break;
 152         case W1_CMD_READ:
 153                 w1_read_block(dev, cmd->data, cmd->len);
 154                 w1_send_read_reply(msg, hdr, cmd);
 155                 break;
 156         case W1_CMD_WRITE:
 157                 w1_write_block(dev, cmd->data, cmd->len);
 158                 break;
 159         default:
 160                 err = -EINVAL;
 161                 break;
 162         }
 163
 164         return err;
 165 }
 166
 167 static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
 168                 struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
 169 {
 170         int err = -EINVAL;
 171         struct cn_msg *msg;
 172         struct w1_netlink_msg *hdr;
 173         struct w1_netlink_cmd *cmd;
 174
 175         msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 176         if (!msg)
 177                 return -ENOMEM;
 178
 179         msg->id = req_msg->id;
 180         msg->seq = req_msg->seq;
 181         msg->ack = 0;
 182         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
 183
 184         hdr = (struct w1_netlink_msg *)(msg + 1);
 185         cmd = (struct w1_netlink_cmd *)(hdr + 1);
 186
 187         hdr->type = W1_MASTER_CMD;
 188         hdr->id = req_hdr->id;
 189         hdr->len = sizeof(struct w1_netlink_cmd);
 190
 191         cmd->cmd = req_cmd->cmd;
 192         cmd->len = 0;
 193
 194         switch (cmd->cmd) {
 195         case W1_CMD_SEARCH:
 196         case W1_CMD_ALARM_SEARCH:
 197                 err = w1_process_search_command(dev, msg,
 198                                 PAGE_SIZE - msg->len - sizeof(struct cn_msg));
 199                 break;
 200         case W1_CMD_READ:
 201         case W1_CMD_WRITE:
 202         case W1_CMD_TOUCH:
 203                 err = w1_process_command_io(dev, req_msg, req_hdr, req_cmd);
 204                 break;
 205         case W1_CMD_RESET:
 206                 err = w1_reset_bus(dev);
 207                 break;
 208         default:
 209                 err = -EINVAL;
 210                 break;
 211         }
 212
 213         kfree(msg);
 214         return err;
 215 }
 216
 217 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 218                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 219 {
 220         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 221                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
 222                 sl->reg_num.crc, cmd->cmd, cmd->len);
 223
 224         return w1_process_command_io(sl->master, msg, hdr, cmd);
 225 }
 226
 227 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 228 {
 229         struct w1_master *m;
 230         struct cn_msg *cn;
 231         struct w1_netlink_msg *w;
 232         u32 *id;
 233
 234         if (mcmd->type != W1_LIST_MASTERS) {
 235                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 236                         __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 237                 return -EPROTO;
 238         }
 239
 240         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 241         if (!cn)
 242                 return -ENOMEM;
 243
 244         cn->id.idx = CN_W1_IDX;
 245         cn->id.val = CN_W1_VAL;
 246
 247         cn->seq = msg->seq;
 248         cn->ack = 1;
 249         cn->len = sizeof(struct w1_netlink_msg);
 250         w = (struct w1_netlink_msg *)(cn + 1);
 251
 252         w->type = W1_LIST_MASTERS;
 253         w->status = 0;
 254         w->len = 0;
 255         id = (u32 *)(w + 1);
 256
 257         mutex_lock(&w1_mlock);
 258         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 259                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 260                         cn_netlink_send(cn, 0, GFP_KERNEL);
 261                         cn->ack++;
 262                         cn->len = sizeof(struct w1_netlink_msg);
 263                         w->len = 0;
 264                         id = (u32 *)(w + 1);
 265                 }
 266
 267                 *id = m->id;
 268                 w->len += sizeof(*id);
 269                 cn->len += sizeof(*id);
 270                 id++;
 271         }
 272         cn->ack = 0;
 273         cn_netlink_send(cn, 0, GFP_KERNEL);
 274         mutex_unlock(&w1_mlock);
 275
 276         kfree(cn);
 277         return 0;
 278 }
 279
 280 static int w1_netlink_send_error(struct cn_msg *rcmsg, struct w1_netlink_msg *rmsg,
 281                 struct w1_netlink_cmd *rcmd, int error)
 282 {
 283         struct cn_msg *cmsg;
 284         struct w1_netlink_msg *msg;
 285         struct w1_netlink_cmd *cmd;
 286
 287         cmsg = kzalloc(sizeof(*msg) + sizeof(*cmd) + sizeof(*cmsg), GFP_KERNEL);
 288         if (!cmsg)
 289                 return -ENOMEM;
 290
 291         msg = (struct w1_netlink_msg *)(cmsg + 1);
 292         cmd = (struct w1_netlink_cmd *)(msg + 1);
 293
 294         memcpy(cmsg, rcmsg, sizeof(*cmsg));
 295         cmsg->len = sizeof(*msg);
 296
 297         memcpy(msg, rmsg, sizeof(*msg));
 298         msg->len = 0;
 299         msg->status = (short)-error;
 300
 301         if (rcmd) {
 302                 memcpy(cmd, rcmd, sizeof(*cmd));
 303                 cmd->len = 0;
 304                 msg->len += sizeof(*cmd);
 305                 cmsg->len += sizeof(*cmd);
 306         }
 307
 308         error = cn_netlink_send(cmsg, 0, GFP_KERNEL);
 309         kfree(cmsg);
 310
 311         return error;
 312 }
 313
 314 static void w1_cn_callback(struct cn_msg *msg, struct netlink_skb_parms *nsp)
 315 {
 316         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 317         struct w1_netlink_cmd *cmd;
 318         struct w1_slave *sl;
 319         struct w1_master *dev;
 320         int err = 0;
 321
 322         while (msg->len && !err) {
 323                 struct w1_reg_num id;
 324                 u16 mlen = m->len;
 325                 u8 *cmd_data = m->data;
 326
 327                 dev = NULL;
 328                 sl = NULL;
 329                 cmd = NULL;
 330
 331                 memcpy(&id, m->id.id, sizeof(id));
 332 #if 0
 333                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 334                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 335 #endif
 336                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 337                         err = -E2BIG;
 338                         break;
 339                 }
 340
 341                 if (m->type == W1_MASTER_CMD) {
 342                         dev = w1_search_master_id(m->id.mst.id);
 343                 } else if (m->type == W1_SLAVE_CMD) {
 344                         sl = w1_search_slave(&id);
 345                         if (sl)
 346                                 dev = sl->master;
 347                 } else {
 348                         err = w1_process_command_root(msg, m);
 349                         goto out_cont;
 350                 }
 351
 352                 if (!dev) {
 353                         err = -ENODEV;
 354                         goto out_cont;
 355                 }
 356
 357                 err = 0;
 358                 if (!mlen)
 359                         goto out_cont;
 360
 361                 mutex_lock(&dev->mutex);
 362
 363                 if (sl && w1_reset_select_slave(sl)) {
 364                         err = -ENODEV;
 365                         goto out_up;
 366                 }
 367
 368                 while (mlen) {
 369                         cmd = (struct w1_netlink_cmd *)cmd_data;
 370
 371                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 372                                 err = -E2BIG;
 373                                 break;
 374                         }
 375
 376                         if (sl)
 377                                 err = w1_process_command_slave(sl, msg, m, cmd);
 378                         else
 379                                 err = w1_process_command_master(dev, msg, m, cmd);
 380
 381                         w1_netlink_send_error(msg, m, cmd, err);
 382                         err = 0;
 383
 384                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 385                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 386                 }
 387 out_up:
 388                 atomic_dec(&dev->refcnt);
 389                 if (sl)
 390                         atomic_dec(&sl->refcnt);
 391                 mutex_unlock(&dev->mutex);
 392 out_cont:
 393                 if (!cmd || err)
 394                         w1_netlink_send_error(msg, m, cmd, err);
 395                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 396                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 397
 398                 /*
 399                  * Let's allow requests for nonexisting devices.
 400                  */
 401                 if (err == -ENODEV)
 402                         err = 0;
 403         }
 404 }
 405
 406 int w1_init_netlink(void)
 407 {
 408         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 409
 410         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 411 }
 412
 413 void w1_fini_netlink(void)
 414 {
 415         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 416
 417         cn_del_callback(&w1_id);
 418 }
 419 #else
 420 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 421 {
 422 }
 423
 424 int w1_init_netlink(void)
 425 {
 426         return 0;
 427 }
 428
 429 void w1_fini_netlink(void)
 430 {
 431 }
 432 #endif