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_process_command_master(struct w1_master *dev, struct cn_msg *req_msg,
  99                 struct w1_netlink_msg *req_hdr, struct w1_netlink_cmd *req_cmd)
 100 {
 101         int err = -EINVAL;
 102         struct cn_msg *msg;
 103         struct w1_netlink_msg *hdr;
 104         struct w1_netlink_cmd *cmd;
 105
 106         msg = kzalloc(PAGE_SIZE, GFP_KERNEL);
 107         if (!msg)
 108                 return -ENOMEM;
 109
 110         msg->id = req_msg->id;
 111         msg->seq = req_msg->seq;
 112         msg->ack = 0;
 113         msg->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd);
 114
 115         hdr = (struct w1_netlink_msg *)(msg + 1);
 116         cmd = (struct w1_netlink_cmd *)(hdr + 1);
 117
 118         hdr->type = W1_MASTER_CMD;
 119         hdr->id = req_hdr->id;
 120         hdr->len = sizeof(struct w1_netlink_cmd);
 121
 122         cmd->cmd = req_cmd->cmd;
 123         cmd->len = 0;
 124
 125         switch (cmd->cmd) {
 126                 case W1_CMD_SEARCH:
 127                 case W1_CMD_ALARM_SEARCH:
 128                         err = w1_process_search_command(dev, msg,
 129                                 PAGE_SIZE - msg->len - sizeof(struct cn_msg));
 130                         break;
 131                 default:
 132                         cmd->res = EINVAL;
 133                         cn_netlink_send(msg, 0, GFP_KERNEL);
 134                         break;
 135         }
 136
 137         kfree(msg);
 138         return err;
 139 }
 140
 141 static int w1_send_read_reply(struct w1_slave *sl, struct cn_msg *msg,
 142                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 143 {
 144         void *data;
 145         struct w1_netlink_msg *h;
 146         struct w1_netlink_cmd *c;
 147         struct cn_msg *cm;
 148         int err;
 149
 150         data = kzalloc(sizeof(struct cn_msg) +
 151                         sizeof(struct w1_netlink_msg) +
 152                         sizeof(struct w1_netlink_cmd) +
 153                         cmd->len, GFP_KERNEL);
 154         if (!data)
 155                 return -ENOMEM;
 156
 157         cm = (struct cn_msg *)(data);
 158         h = (struct w1_netlink_msg *)(cm + 1);
 159         c = (struct w1_netlink_cmd *)(h + 1);
 160
 161         memcpy(cm, msg, sizeof(struct cn_msg));
 162         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
 163         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
 164
 165         cm->ack = msg->seq+1;
 166         cm->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd->len;
 167
 168         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
 169
 170         memcpy(c->data, cmd->data, c->len);
 171
 172         err = cn_netlink_send(cm, 0, GFP_KERNEL);
 173
 174         kfree(data);
 175
 176         return err;
 177 }
 178
 179 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 180                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 181 {
 182         int err = 0;
 183
 184         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 185                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id, sl->reg_num.crc,
 186                 cmd->cmd, cmd->len);
 187
 188         switch (cmd->cmd) {
 189                 case W1_CMD_TOUCH:
 190                         w1_touch_block(sl->master, cmd->data, cmd->len);
 191                         w1_send_read_reply(sl, msg, hdr, cmd);
 192                         break;
 193                 case W1_CMD_READ:
 194                         w1_read_block(sl->master, cmd->data, cmd->len);
 195                         w1_send_read_reply(sl, msg, hdr, cmd);
 196                         break;
 197                 case W1_CMD_WRITE:
 198                         w1_write_block(sl->master, cmd->data, cmd->len);
 199                         break;
 200                 default:
 201                         err = -1;
 202                         break;
 203         }
 204
 205         return err;
 206 }
 207
 208 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 209 {
 210         struct w1_master *m;
 211         struct cn_msg *cn;
 212         struct w1_netlink_msg *w;
 213         u32 *id;
 214
 215         if (mcmd->type != W1_LIST_MASTERS) {
 216                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 217                                 __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 218                 return -EPROTO;
 219         }
 220
 221         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 222         if (!cn)
 223                 return -ENOMEM;
 224
 225         cn->id.idx = CN_W1_IDX;
 226         cn->id.val = CN_W1_VAL;
 227
 228         cn->seq = msg->seq;
 229         cn->ack = 1;
 230         cn->len = sizeof(struct w1_netlink_msg);
 231         w = (struct w1_netlink_msg *)(cn + 1);
 232
 233         w->type = W1_LIST_MASTERS;
 234         w->reserved = 0;
 235         w->len = 0;
 236         id = (u32 *)(w + 1);
 237
 238         mutex_lock(&w1_mlock);
 239         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 240                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 241                         cn_netlink_send(cn, 0, GFP_KERNEL);
 242                         cn->ack++;
 243                         cn->len = sizeof(struct w1_netlink_msg);
 244                         w->len = 0;
 245                         id = (u32 *)(w + 1);
 246                 }
 247
 248                 *id = m->id;
 249                 w->len += sizeof(*id);
 250                 cn->len += sizeof(*id);
 251                 id++;
 252         }
 253         cn->ack = 0;
 254         cn_netlink_send(cn, 0, GFP_KERNEL);
 255         mutex_unlock(&w1_mlock);
 256
 257         kfree(cn);
 258         return 0;
 259 }
 260
 261 static void w1_cn_callback(void *data)
 262 {
 263         struct cn_msg *msg = data;
 264         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 265         struct w1_netlink_cmd *cmd;
 266         struct w1_slave *sl;
 267         struct w1_master *dev;
 268         int err = 0;
 269
 270         while (msg->len && !err) {
 271                 struct w1_reg_num id;
 272                 u16 mlen = m->len;
 273                 u8 *cmd_data = m->data;
 274
 275                 dev = NULL;
 276                 sl = NULL;
 277
 278                 memcpy(&id, m->id.id, sizeof(id));
 279 #if 0
 280                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 281                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 282 #endif
 283                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 284                         err = -E2BIG;
 285                         break;
 286                 }
 287
 288                 if (m->type == W1_MASTER_CMD) {
 289                         dev = w1_search_master_id(m->id.mst.id);
 290                 } else if (m->type == W1_SLAVE_CMD) {
 291                         sl = w1_search_slave(&id);
 292                         if (sl)
 293                                 dev = sl->master;
 294                 } else {
 295                         err = w1_process_command_root(msg, m);
 296                         goto out_cont;
 297                 }
 298
 299                 if (!dev) {
 300                         err = -ENODEV;
 301                         goto out_cont;
 302                 }
 303
 304                 err = 0;
 305                 if (!mlen)
 306                         goto out_cont;
 307
 308                 mutex_lock(&dev->mutex);
 309
 310                 if (sl && w1_reset_select_slave(sl)) {
 311                         err = -ENODEV;
 312                         goto out_up;
 313                 }
 314
 315                 while (mlen) {
 316                         cmd = (struct w1_netlink_cmd *)cmd_data;
 317
 318                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 319                                 err = -E2BIG;
 320                                 break;
 321                         }
 322
 323                         if (sl)
 324                                 w1_process_command_slave(sl, msg, m, cmd);
 325                         else
 326                                 w1_process_command_master(dev, msg, m, cmd);
 327
 328                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 329                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 330                 }
 331 out_up:
 332                 atomic_dec(&dev->refcnt);
 333                 if (sl)
 334                         atomic_dec(&sl->refcnt);
 335                 mutex_unlock(&dev->mutex);
 336 out_cont:
 337                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 338                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 339
 340                 /*
 341                  * Let's allow requests for nonexisting devices.
 342                  */
 343                 if (err == -ENODEV)
 344                         err = 0;
 345         }
 346 }
 347
 348 int w1_init_netlink(void)
 349 {
 350         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 351
 352         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 353 }
 354
 355 void w1_fini_netlink(void)
 356 {
 357         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 358
 359         cn_del_callback(&w1_id);
 360 }
 361 #else
 362 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 363 {
 364 }
 365
 366 int w1_init_netlink(void)
 367 {
 368         return 0;
 369 }
 370
 371 void w1_fini_netlink(void)
 372 {
 373 }
 374 #endif