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_READ:
 112                         w1_read_block(sl->master, cmd->data, cmd->len);
 113                         w1_send_read_reply(sl, msg, hdr, cmd);
 114                         break;
 115                 case W1_CMD_WRITE:
 116                         w1_write_block(sl->master, cmd->data, cmd->len);
 117                         break;
 118                 case W1_CMD_SEARCH:
 119                 case W1_CMD_ALARM_SEARCH:
 120                         w1_search_process(sl->master,
 121                                         (cmd->cmd == W1_CMD_ALARM_SEARCH)?W1_ALARM_SEARCH:W1_SEARCH);
 122                         break;
 123                 default:
 124                         err = -1;
 125                         break;
 126         }
 127
 128         return err;
 129 }
 130
 131 static void w1_cn_callback(void *data)
 132 {
 133         struct cn_msg *msg = data;
 134         struct w1_netlink_msg *m = (struct w1_netlink_msg *)(msg + 1);
 135         struct w1_netlink_cmd *cmd;
 136         struct w1_slave *sl;
 137         struct w1_master *dev;
 138         int err = 0;
 139
 140         while (msg->len && !err) {
 141                 struct w1_reg_num id;
 142                 u16 mlen = m->len;
 143                 u8 *cmd_data = m->data;
 144
 145                 dev = NULL;
 146                 sl = NULL;
 147
 148                 memcpy(&id, m->id.id, sizeof(id));
 149 #if 0
 150                 printk("%s: %02x.%012llx.%02x: type=%02x, len=%u.\n",
 151                                 __func__, id.family, (unsigned long long)id.id, id.crc, m->type, m->len);
 152 #endif
 153                 if (m->len + sizeof(struct w1_netlink_msg) > msg->len) {
 154                         err = -E2BIG;
 155                         break;
 156                 }
 157
 158                 if (!mlen)
 159                         goto out_cont;
 160
 161                 if (m->type == W1_MASTER_CMD) {
 162                         dev = w1_search_master_id(m->id.mst.id);
 163                 } else if (m->type == W1_SLAVE_CMD) {
 164                         sl = w1_search_slave(&id);
 165                         if (sl)
 166                                 dev = sl->master;
 167                 }
 168
 169                 if (!dev) {
 170                         err = -ENODEV;
 171                         goto out_cont;
 172                 }
 173
 174                 mutex_lock(&dev->mutex);
 175
 176                 if (sl && w1_reset_select_slave(sl)) {
 177                         err = -ENODEV;
 178                         goto out_up;
 179                 }
 180
 181                 while (mlen) {
 182                         cmd = (struct w1_netlink_cmd *)cmd_data;
 183
 184                         if (cmd->len + sizeof(struct w1_netlink_cmd) > mlen) {
 185                                 err = -E2BIG;
 186                                 break;
 187                         }
 188
 189                         if (sl)
 190                                 w1_process_command_slave(sl, msg, m, cmd);
 191                         else
 192                                 w1_process_command_master(dev, msg, m, cmd);
 193
 194                         cmd_data += cmd->len + sizeof(struct w1_netlink_cmd);
 195                         mlen -= cmd->len + sizeof(struct w1_netlink_cmd);
 196                 }
 197 out_up:
 198                 atomic_dec(&dev->refcnt);
 199                 if (sl)
 200                         atomic_dec(&sl->refcnt);
 201                 mutex_unlock(&dev->mutex);
 202 out_cont:
 203                 msg->len -= sizeof(struct w1_netlink_msg) + m->len;
 204                 m = (struct w1_netlink_msg *)(((u8 *)m) + sizeof(struct w1_netlink_msg) + m->len);
 205
 206                 /*
 207                  * Let's allow requests for nonexisting devices.
 208                  */
 209                 if (err == -ENODEV)
 210                         err = 0;
 211         }
 212 #if 0
 213         if (err) {
 214                 printk("%s: malformed message. Dropping.\n", __func__);
 215         }
 216 #endif
 217 }
 218
 219 int w1_init_netlink(void)
 220 {
 221         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 222
 223         return cn_add_callback(&w1_id, "w1", &w1_cn_callback);
 224 }
 225
 226 void w1_fini_netlink(void)
 227 {
 228         struct cb_id w1_id = {.idx = CN_W1_IDX, .val = CN_W1_VAL};
 229
 230         cn_del_callback(&w1_id);
 231 }
 232 #else
 233 void w1_netlink_send(struct w1_master *dev, struct w1_netlink_msg *msg)
 234 {
 235 }
 236
 237 int w1_init_netlink(void)
 238 {
 239         return 0;
 240 }
 241
 242 void w1_fini_netlink(void)
 243 {
 244 }
 245 #endif