udevdb.c

   1 /*
   2  * udevdb.c - udev database library
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7  * Copyright (C) 2003 IBM Corp.
   8  *
   9  *      This program is free software; you can redistribute it and/or modify it
  10  *      under the terms of the GNU General Public License as published by the
  11  *      Free Software Foundation version 2 of the License.
  12  *
  13  *      This program is distributed in the hope that it will be useful, but
  14  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  15  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  *      General Public License for more details.
  17  *
  18  *      You should have received a copy of the GNU General Public License along
  19  *      with this program; if not, write to the Free Software Foundation, Inc.,
  20  *      675 Mass Ave, Cambridge, MA 02139, USA.
  21  *
  22  */
  23
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stddef.h>
  28 #include <fcntl.h>
  29 #include <string.h>
  30 #include <sys/stat.h>
  31 #include <errno.h>
  32 #include <signal.h>
  33
  34 #include "libsysfs/sysfs/libsysfs.h"
  35 #include "udev.h"
  36 #include "udev_lib.h"
  37 #include "udev_version.h"
  38 #include "logging.h"
  39 #include "namedev.h"
  40 #include "udevdb.h"
  41 #include "tdb/tdb.h"
  42
  43 static TDB_CONTEXT *udevdb;
  44 sig_atomic_t gotalarm;
  45
  46 int udevdb_add_dev(struct udevice *udev)
  47 {
  48         TDB_DATA key, data;
  49         char keystr[SYSFS_PATH_MAX];
  50
  51         if (udev->test_run)
  52                 return 0;
  53
  54         if (udevdb == NULL)
  55                 return -1;
  56
  57         memset(keystr, 0x00, SYSFS_PATH_MAX);
  58         strfieldcpy(keystr, udev->devpath);
  59         key.dptr = keystr;
  60         key.dsize = strlen(keystr) + 1;
  61
  62         data.dptr = (void *) udev;
  63         data.dsize = UDEVICE_DB_LEN;
  64         dbg("store key '%s' for device '%s'", keystr, udev->name);
  65
  66         return tdb_store(udevdb, key, data, TDB_REPLACE);
  67 }
  68
  69 int udevdb_get_dev(const char *path, struct udevice *udev)
  70 {
  71         TDB_DATA key, data;
  72
  73         if (udevdb == NULL)
  74                 return -1;
  75
  76         if (path == NULL)
  77                 return -ENODEV;
  78
  79         key.dptr = (void *)path;
  80         key.dsize = strlen(path) + 1;
  81
  82         data = tdb_fetch(udevdb, key);
  83         if (data.dptr == NULL || data.dsize == 0)
  84                 return -ENODEV;
  85
  86         memset(udev, 0x00, sizeof(struct udevice));
  87         memcpy(udev, data.dptr, UDEVICE_DB_LEN);
  88
  89         return 0;
  90 }
  91
  92 int udevdb_delete_dev(const char *path)
  93 {
  94         TDB_DATA key;
  95         char keystr[SYSFS_PATH_MAX];
  96
  97         if (udevdb == NULL)
  98                 return -1;
  99
 100         if (path == NULL)
 101                 return -EINVAL;
 102
 103         memset(keystr, 0, sizeof(keystr));
 104         strfieldcpy(keystr, path);
 105
 106         key.dptr = keystr;
 107         key.dsize = strlen(keystr) + 1;
 108
 109         return tdb_delete(udevdb, key);
 110 }
 111
 112 /**
 113  * udevdb_exit: closes database
 114  */
 115 void udevdb_exit(void)
 116 {
 117         if (udevdb != NULL) {
 118                 tdb_close(udevdb);
 119                 udevdb = NULL;
 120         }
 121 }
 122
 123 /**
 124  * udevdb_init: initializes database
 125  * @init_flag: UDEVDB_INTERNAL - database stays in memory
 126  *             UDEVDB_DEFAULT - database is written to a file
 127  */
 128 int udevdb_init(int init_flag)
 129 {
 130         if (init_flag != UDEVDB_DEFAULT && init_flag != UDEVDB_INTERNAL)
 131                 return -EINVAL;
 132
 133         tdb_set_lock_alarm(&gotalarm);
 134
 135         udevdb = tdb_open(udev_db_filename, 0, init_flag, O_RDWR | O_CREAT, 0644);
 136         if (udevdb == NULL) {
 137                 if (init_flag == UDEVDB_INTERNAL)
 138                         dbg("unable to initialize in-memory database");
 139                 else
 140                         dbg("unable to initialize database at '%s'", udev_db_filename);
 141                 return -EACCES;
 142         }
 143         return 0;
 144 }
 145
 146 /**
 147  * udevdb_open_ro: open database for reading
 148  */
 149 int udevdb_open_ro(void)
 150 {
 151         udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
 152         if (udevdb == NULL) {
 153                 dbg("unable to open database at '%s'", udev_db_filename);
 154                 return -EACCES;
 155         }
 156         return 0;
 157 }
 158
 159 static int (*user_record_callback) (const char *path, struct udevice *dev);
 160
 161 static int traverse_callback(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
 162 {
 163         return user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr);
 164 }
 165
 166 /**
 167  * udevdb_call_foreach: dumps whole database by passing record data to user function
 168  * @user_record_handler: user function called for every record in the database
 169  */
 170 int udevdb_call_foreach(int (*user_record_handler) (const char *path, struct udevice *dev))
 171 {
 172         int retval = 0;
 173
 174         if (udevdb == NULL)
 175                 return -1;
 176
 177         if (user_record_handler == NULL) {
 178                 dbg("invalid user record handling function");
 179                 return -EINVAL;
 180         }
 181         user_record_callback = user_record_handler;
 182         retval = tdb_traverse(udevdb, traverse_callback, NULL);
 183         if (retval < 0)
 184                 return -ENODEV;
 185         else
 186                 return 0;
 187 }
 188
 189 static struct udevice *find_dev;
 190 static char *find_path;
 191 static const char *find_name;
 192 static int find_found;
 193
 194 static int find_device_by_name(const char *path, struct udevice *udev)
 195 {
 196         char *pos;
 197         int len;
 198
 199         if (strncmp(udev->name, find_name, sizeof(udev->name)) == 0) {
 200                 memcpy(find_dev, udev, sizeof(struct udevice));
 201                 strfieldcpymax(find_path, path, NAME_SIZE);
 202                 find_found = 1;
 203                 /* stop search */
 204                 return 1;
 205         }
 206         /* look for matching symlink*/
 207         foreach_strpart(udev->symlink, " ", pos, len) {
 208                 if (strncmp(pos, find_name, len) != 0)
 209                         continue;
 210
 211                 if (len != strlen(find_name))
 212                         continue;
 213
 214                 memcpy(find_dev, udev, sizeof(struct udevice));
 215                 strfieldcpymax(find_path, path, NAME_SIZE);
 216                 find_found = 1;
 217                 return 1;
 218         }
 219         return 0;
 220 }
 221
 222 /**
 223  * udevdb_get_dev_byname: search device with given name by traversing the whole database
 224  */
 225 int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev)
 226 {
 227         find_found = 0;
 228         find_path = path;
 229         find_dev = dev;
 230         find_name = name;
 231         udevdb_call_foreach(find_device_by_name);
 232         if (find_found == 1)
 233                 return 0;
 234         else
 235                 return -1;
 236 }