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 int w1_process_command_master(struct w1_master *dev, struct cn_msg *msg,
  51                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
  52 {
  53         dev_dbg(&dev->dev, "%s: %s: cmd=%02x, len=%u.\n",
  54                 __func__, dev->name, cmd->cmd, cmd->len);
  55
  56         if (cmd->cmd != W1_CMD_SEARCH && cmd->cmd != W1_CMD_ALARM_SEARCH)
  57                 return -EINVAL;
  58
  59         w1_search_process(dev, (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
  60         return 0;
  61 }
  62
  63 static int w1_send_read_reply(struct w1_slave *sl, struct cn_msg *msg,
  64                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
  65 {
  66         void *data;
  67         struct w1_netlink_msg *h;
  68         struct w1_netlink_cmd *c;
  69         struct cn_msg *cm;
  70         int err;
  71
  72         data = kzalloc(sizeof(struct cn_msg) +
  73                         sizeof(struct w1_netlink_msg) +
  74                         sizeof(struct w1_netlink_cmd) +
  75                         cmd->len, GFP_KERNEL);
  76         if (!data)
  77                 return -ENOMEM;
  78
  79         cm = (struct cn_msg *)(data);
  80         h = (struct w1_netlink_msg *)(cm + 1);
  81         c = (struct w1_netlink_cmd *)(h + 1);
  82
  83         memcpy(cm, msg, sizeof(struct cn_msg));
  84         memcpy(h, hdr, sizeof(struct w1_netlink_msg));
  85         memcpy(c, cmd, sizeof(struct w1_netlink_cmd));
  86
  87         cm->ack = msg->seq+1;
  88         cm->len = sizeof(struct w1_netlink_msg) + sizeof(struct w1_netlink_cmd) + cmd->len;
  89
  90         h->len = sizeof(struct w1_netlink_cmd) + cmd->len;
  91
  92         memcpy(c->data, cmd->data, c->len);
  93
  94         err = cn_netlink_send(cm, 0, GFP_KERNEL);
  95
  96         kfree(data);
  97
  98         return err;
  99 }
 100
 101 static int w1_process_command_slave(struct w1_slave *sl, struct cn_msg *msg,
 102                 struct w1_netlink_msg *hdr, struct w1_netlink_cmd *cmd)
 103 {
 104         int err = 0;
 105
 106         dev_dbg(&sl->master->dev, "%s: %02x.%012llx.%02x: cmd=%02x, len=%u.\n",
 107                 __func__, sl->reg_num.family, (unsigned long long)sl->reg_num.id, sl->reg_num.crc,
 108                 cmd->cmd, cmd->len);
 109
 110         switch (cmd->cmd) {
 111                 case W1_CMD_TOUCH:
 112                         w1_touch_block(sl->master, cmd->data, cmd->len);
 113                         w1_send_read_reply(sl, msg, hdr, cmd);
 114                         break;
 115                 case W1_CMD_READ:
 116                         w1_read_block(sl->master, cmd->data, cmd->len);
 117                         w1_send_read_reply(sl, msg, hdr, cmd);
 118                         break;
 119                 case W1_CMD_WRITE:
 120                         w1_write_block(sl->master, cmd->data, cmd->len);
 121                         break;
 122                 case W1_CMD_SEARCH:
 123                 case W1_CMD_ALARM_SEARCH:
 124                         w1_search_process(sl->master,
 125                                         (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
 126                         break;
 127                 default:
 128                         err = -1;
 129                         break;
 130         }
 131
 132         return err;
 133 }
 134
 135 static int w1_process_command_root(struct cn_msg *msg, struct w1_netlink_msg *mcmd)
 136 {
 137         struct w1_master *m;
 138         struct cn_msg *cn;
 139         struct w1_netlink_msg *w;
 140         u32 *id;
 141
 142         if (mcmd->type != W1_LIST_MASTERS) {
 143                 printk(KERN_NOTICE "%s: msg: %x.%x, wrong type: %u, len: %u.\n",
 144                                 __func__, msg->id.idx, msg->id.val, mcmd->type, mcmd->len);
 145                 return -EPROTO;
 146         }
 147
 148         cn = kmalloc(PAGE_SIZE, GFP_KERNEL);
 149         if (!cn)
 150                 return -ENOMEM;
 151
 152         cn->id.idx = CN_W1_IDX;
 153         cn->id.val = CN_W1_VAL;
 154
 155         cn->seq = msg->seq;
 156         cn->ack = 1;
 157         cn->len = sizeof(struct w1_netlink_msg);
 158         w = (struct w1_netlink_msg *)(cn + 1);
 159
 160         w->type = W1_LIST_MASTERS;
 161         w->reserved = 0;
 162         w->len = 0;
 163         id = (u32 *)(w + 1);
 164
 165         mutex_lock(&w1_mlock);
 166         list_for_each_entry(m, &w1_masters, w1_master_entry) {
 167                 if (cn->len + sizeof(*id) > PAGE_SIZE - sizeof(struct cn_msg)) {
 168                         cn_netlink_send(cn, 0, GFP_KERNEL);
 169                         cn->ack++;
 170                         cn->len = sizeof(struct w1_netlink_msg);
 171                         w->len = 0;
 172                         id = (u32 *)(w + 1);
 173                 }
 174
 175                 *id = m->id;
 176                 w->len += sizeof(*id);
 177                 cn->len += sizeof(*id);
 178                 id++;
 179         }
 180         cn->ack = 0;
 181         cn_netlink_send(cn, 0, GFP_KERNEL);
 182         mutex_unlock(&w1_mlock);
 183
 184         kfree(cn);
 185         return 0;
 186 }
 187
 188 static void w1_cn_callback(void *data)
 189 {
 190         struct cn_msg *msg = data;
 191         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 192         struct w1_netlink_cmd *cmd;
 193         struct w1_slave *sl;
 194         struct w1_master *dev;
 195         int err = 0;
 196
 197         while (msg->len && !err) {
 198                 struct w1_reg_num id;
 199                 u16 mlen = m->len;
 200                 u8 *cmd_data = m->data;
 201
 202                 dev = NULL;
 203                 sl = NULL;
 204
 205                 memcpy(&id, m->id.id, sizeof(id));
 206 #if 0
 207                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 208                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 209 #endif
 210                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 211                         err = -E2BIG;
 212                         break;
 213                 }
 214
 215                 if (m->type == W1_MASTER_CMD) {
 216                         dev = w1_search_master_id(m->id.mst.id);
 217                 } else if (m->type == W1_SLAVE_CMD) {
 218                         sl = w1_search_slave(&id);
 219                         if (sl)
 220                                 dev = sl->master;
 221                 } else {
 222                         err = w1_process_command_root(msg, m);
 223                         goto out_cont;
 224                 }
 225
 226                 if (!dev) {
 227                         err = -ENODEV;
 228                         goto out_cont;
 229                 }
 230
 231                 err = 0;
 232                 if (!mlen)
 233                         goto out_cont;
 234
 235                 mutex_lock(&dev->mutex);
 236
 237                 if (sl && w1_reset_select_slave(sl)) {
 238                         err = -ENODEV;
 239                         goto out_up;
 240                 }
 241
 242                 while (mlen) {
 243                         cmd = (struct w1_netlink_cmd *)cmd_data;
 244
 245                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 246                                 err = -E2BIG;
 247                                 break;
 248                         }
 249
 250                         if (sl)
 251                                 w1_process_command_slave(sl, msg, m, cmd);
 252                         else
 253                                 w1_process_command_master(dev, msg, m, cmd);
 254
 255                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 256                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 257                 }
 258 out_up:
 259                 atomic_dec(&dev->refcnt);
 260                 if (sl)
 261                         atomic_dec(&sl->refcnt);
 262                 mutex_unlock(&dev->mutex);
 263 out_cont:
 264                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 265                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 266
 267                 /*
 268                  * Let's allow requests for nonexisting devices.
 269                  */
 270                 if (err == -ENODEV)
 271                         err = 0;
 272         }
 273 #if 0
 274         if (err) {
 275                 printk("%s: malformed message. Dropping.\n", __func__);
 276         }
 277 #endif
 278 }
 279
 280 int w1_init_netlink(void)
 281 {
 282         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 283
 284         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 285 }
 286
 287 void w1_fini_netlink(void)
 288 {
 289         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 290
 291         cn_del_callback(&w1_id);
 292 }
 293 #else
 294 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 295 {
 296 }
 297
 298 int w1_init_netlink(void)
 299 {
 300         return 0;
 301 }
 302
 303 void w1_fini_netlink(void)
 304 {
 305 }
 306 #endif