linux/drivers/w1/w1_netlink.c
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   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)))
  32void 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
  51static 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
  78static 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
  99static 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
 138static 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
 163static 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
 213static 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
 223static 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
 276static 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
 310static 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                }
 383out_up:
 384                atomic_dec(&dev->refcnt);
 385                if (sl)
 386                        atomic_dec(&sl->refcnt);
 387                mutex_unlock(&dev->mutex);
 388out_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
 402int 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
 409void 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
 416void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 417{
 418}
 419
 420int w1_init_netlink(void)
 421{
 422        return 0;
 423}
 424
 425void w1_fini_netlink(void)
 426{
 427}
 428#endif
 429
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