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