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/skbuff.h>
  23 #include <linux/netlink.h>
  24 #include <linux/connector.h>
  25
  26 #include "w1.h"
  27 #include "w1_log.h"
  28 #include "w1_netlink.h"
  29
  30 #if defined(CONFIG_W1_CON) && (defined(CONFIG_CONNECTOR) || (defined(CONFIG_CONNECTOR_MODULE) && defined(CONFIG_W1_MODULE)))
  31 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
  32 {
  33         char buf[sizeof(struct cn_msg) + sizeof(struct w1_netlink_msg)];
  34         struct cn_msg *m = (struct cn_msg *)buf;
  35         struct w1_netlink_msg *w = (struct w1_netlink_msg *)(m+1);
  36
  37         memset(buf, 0, sizeof(buf));
  38
  39         m->id.idx = CN_W1_IDX;
  40         m->id.val = CN_W1_VAL;
  41
  42         m->seq = dev->seq++;
  43         m->len = sizeof(struct w1_netlink_msg);
  44
  45         memcpy(w, msg, sizeof(struct w1_netlink_msg));
  46
  47         cn_netlink_send(m, 0, GFP_KERNEL);
  48 }
  49
  50 static void w1_send_slave(struct w1_master *dev, u64 rn)
  51 {
  52         struct cn_msg *msg = dev->priv;
  53         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  54         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  55         int avail;
  56
  57         avail = dev->priv_size - cmd->len;
  58
  59         if (avail > 8) {
  60                 u64 *data = (void *)(cmd + 1) + cmd->len;
  61
  62                 *data = rn;
  63                 cmd->len += 8;
  64                 hdr->len += 8;
  65                 msg->len += 8;
  66                 return;
  67         }
  68
  69         msg->ack++;
  70         cn_netlink_send(msg, 0, GFP_KERNEL);
  71
  72         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
  73         hdr->len = sizeof(struct w1_netlink_cmd);
  74         cmd->len = 0;
  75 }
  76
  77 static int w1_process_search_command(struct w1_master *dev, struct cn_msg *msg,
  78                 unsigned int avail)
  79 {
  80         struct w1_netlink_msg *hdr = (struct w1_netlink_msg *)(msg + 1);
  81         struct w1_netlink_cmd *cmd = (struct w1_netlink_cmd *)(hdr + 1);
  82         int search_type = (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH;
  83
  84         dev->priv = msg;
  85         dev->priv_size = avail;
  86
  87         w1_search_devices(dev, search_type, w1_send_slave);
  88
  89         msg->ack = 0;
  90         cn_netlink_send(msg, 0, GFP_KERNEL);
  91
  92         dev->priv = NULL;
  93         dev->priv_size = 0;
  94
  95         return 0;
  96 }
  97
  98 static int w1_send_read_reply(struct cn_msg *msg, struct w1_netlink_msg *hdr,
  99                 struct w1_netlink_cmd *cmd)
 100 {
 101         void *data;
 102         struct w1_netlink_msg *h;
 103         struct w1_netlink_cmd *c;
 104         struct cn_msg *cm;
 105         int err;
 106
 107         data = kzalloc(sizeof(struct cn_msg) +
 108                         sizeof(struct w1_netlink_msg) +
 109                         sizeof(struct w1_netlink_cmd) +
 110                         cmd->len, GFP_KERNEL);
 111         if (!data)
 112                 return -ENOMEM;
 113
 114         cm = (struct cn_msg *)(data);
 115         h = (struct w1_netlink_msg *)(cm + 1);
 116         c = (struct w1_netlink_cmd *)(h + 1);
 117
 118         memcpy(cm, msg, sizeof(struct cn_msg));
 119         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
 120         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
 121
 122         cm->ack = msg->seq+1;
 123         cm->len = sizeof(struct w1_netlink_msg) +
 124                 sizeof(struct w1_netlink_cmd) + cmd->len;
 125
 126         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
 127
 128         memcpy(c->data, cmd->data, c->len);
 129
 130         err = cn_netlink_send(cm, 0, GFP_KERNEL);
 131
 132         kfree(data);
 133
 134         return err;
 135 }
 136
 137 static int w1_process_command_io(struct w1_master *dev, struct cn_msg *msg,
 138                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 139 {
 140         int err = 0;
 141
 142         switch (cmd->cmd) {
 143         case W1_CMD_TOUCH:
 144                 w1_touch_block(dev, cmd->data, cmd->len);
 145                 w1_send_read_reply(msg, hdr, cmd);
 146                 break;
 147         case W1_CMD_READ:
 148                 w1_read_block(dev, cmd->data, cmd->len);
 149                 w1_send_read_reply(msg, hdr, cmd);
 150                 break;
 151         case W1_CMD_WRITE:
 152                 w1_write_block(dev, cmd->data, cmd->len);
 153                 break;
 154         default:
 155                 err = -1;
 156                 break;
 157         }
 158
 159         return err;
 160 }
 161
 162 static int w1_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
 163                 struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
 164 {
 165         int err = -EINVAL;
 166         struct cn_msg *msg;
 167         struct w1_netlink_msg *hdr;
 168         struct w1_netlink_cmd *cmd;
 169
 170         msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 171         if (!msg)
 172                 return -ENOMEM;
 173
 174         msg->id = req_msg->id;
 175         msg->seq = req_msg->seq;
 176         msg->ack = 0;
 177         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
 178
 179         hdr = (struct w1_netlink_msg *)(msg + 1);
 180         cmd = (struct w1_netlink_cmd *)(hdr + 1);
 181
 182         hdr->type = W1_MASTER_CMD;
 183         hdr->id = req_hdr->id;
 184         hdr->len = sizeof(struct w1_netlink_cmd);
 185
 186         cmd->cmd = req_cmd->cmd;
 187         cmd->len = 0;
 188
 189         switch (cmd->cmd) {
 190         case W1_CMD_SEARCH:
 191         case W1_CMD_ALARM_SEARCH:
 192                 err = w1_process_search_command(dev, msg,
 193                                 PAGE_SIZE - msg->len - sizeof(struct cn_msg));
 194                 break;
 195         case W1_CMD_READ:
 196         case W1_CMD_WRITE:
 197         case W1_CMD_TOUCH:
 198                 err = w1_process_command_io(dev, msg, hdr, cmd);
 199                 break;
 200         default:
 201                 cmd->res = EINVAL;
 202                 cn_netlink_send(msg, 0, GFP_KERNEL);
 203                 break;
 204         }
 205
 206         kfree(msg);
 207         return err;
 208 }
 209
 210 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 211                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 212 {
 213         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 214                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id,
 215                 sl->reg_num.crc, cmd->cmd, cmd->len);
 216
 217         return w1_process_command_io(sl->master, msg, hdr, cmd);
 218 }
 219
 220 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 221 {
 222         struct w1_master *m;
 223         struct cn_msg *cn;
 224         struct w1_netlink_msg *w;
 225         u32 *id;
 226
 227         if (mcmd->type != W1_LIST_MASTERS) {
 228                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 229                         __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 230                 return -EPROTO;
 231         }
 232
 233         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 234         if (!cn)
 235                 return -ENOMEM;
 236
 237         cn->id.idx = CN_W1_IDX;
 238         cn->id.val = CN_W1_VAL;
 239
 240         cn->seq = msg->seq;
 241         cn->ack = 1;
 242         cn->len = sizeof(struct w1_netlink_msg);
 243         w = (struct w1_netlink_msg *)(cn + 1);
 244
 245         w->type = W1_LIST_MASTERS;
 246         w->reserved = 0;
 247         w->len = 0;
 248         id = (u32 *)(w + 1);
 249
 250         mutex_lock(&w1_mlock);
 251         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 252                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 253                         cn_netlink_send(cn, 0, GFP_KERNEL);
 254                         cn->ack++;
 255                         cn->len = sizeof(struct w1_netlink_msg);
 256                         w->len = 0;
 257                         id = (u32 *)(w + 1);
 258                 }
 259
 260                 *id = m->id;
 261                 w->len += sizeof(*id);
 262                 cn->len += sizeof(*id);
 263                 id++;
 264         }
 265         cn->ack = 0;
 266         cn_netlink_send(cn, 0, GFP_KERNEL);
 267         mutex_unlock(&w1_mlock);
 268
 269         kfree(cn);
 270         return 0;
 271 }
 272
 273 static void w1_cn_callback(void *data)
 274 {
 275         struct cn_msg *msg = data;
 276         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 277         struct w1_netlink_cmd *cmd;
 278         struct w1_slave *sl;
 279         struct w1_master *dev;
 280         int err = 0;
 281
 282         while (msg->len && !err) {
 283                 struct w1_reg_num id;
 284                 u16 mlen = m->len;
 285                 u8 *cmd_data = m->data;
 286
 287                 dev = NULL;
 288                 sl = NULL;
 289
 290                 memcpy(&id, m->id.id, sizeof(id));
 291 #if 0
 292                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 293                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 294 #endif
 295                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 296                         err = -E2BIG;
 297                         break;
 298                 }
 299
 300                 if (m->type == W1_MASTER_CMD) {
 301                         dev = w1_search_master_id(m->id.mst.id);
 302                 } else if (m->type == W1_SLAVE_CMD) {
 303                         sl = w1_search_slave(&id);
 304                         if (sl)
 305                                 dev = sl->master;
 306                 } else {
 307                         err = w1_process_command_root(msg, m);
 308                         goto out_cont;
 309                 }
 310
 311                 if (!dev) {
 312                         err = -ENODEV;
 313                         goto out_cont;
 314                 }
 315
 316                 err = 0;
 317                 if (!mlen)
 318                         goto out_cont;
 319
 320                 mutex_lock(&dev->mutex);
 321
 322                 if (sl && w1_reset_select_slave(sl)) {
 323                         err = -ENODEV;
 324                         goto out_up;
 325                 }
 326
 327                 while (mlen) {
 328                         cmd = (struct w1_netlink_cmd *)cmd_data;
 329
 330                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 331                                 err = -E2BIG;
 332                                 break;
 333                         }
 334
 335                         if (sl)
 336                                 w1_process_command_slave(sl, msg, m, cmd);
 337                         else
 338                                 w1_process_command_master(dev, msg, m, cmd);
 339
 340                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 341                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 342                 }
 343 out_up:
 344                 atomic_dec(&dev->refcnt);
 345                 if (sl)
 346                         atomic_dec(&sl->refcnt);
 347                 mutex_unlock(&dev->mutex);
 348 out_cont:
 349                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 350                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 351
 352                 /*
 353                  * Let's allow requests for nonexisting devices.
 354                  */
 355                 if (err == -ENODEV)
 356                         err = 0;
 357         }
 358 }
 359
 360 int w1_init_netlink(void)
 361 {
 362         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 363
 364         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 365 }
 366
 367 void w1_fini_netlink(void)
 368 {
 369         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 370
 371         cn_del_callback(&w1_id);
 372 }
 373 #else
 374 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 375 {
 376 }
 377
 378 int w1_init_netlink(void)
 379 {
 380         return 0;
 381 }
 382
 383 void w1_fini_netlink(void)
 384 {
 385 }
 386 #endif