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 #define _KLIBC_HAS_ARCH_SIG_ATOMIC_T
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stddef.h>
  29 #include <fcntl.h>
  30 #include <string.h>
  31 #include <sys/stat.h>
  32 #include <errno.h>
  33 #include <signal.h>
  34
  35 #include "libsysfs/sysfs/libsysfs.h"
  36 #include "udev.h"
  37 #include "udev_lib.h"
  38 #include "udev_version.h"
  39 #include "logging.h"
  40 #include "namedev.h"
  41 #include "udevdb.h"
  42 #include "tdb/tdb.h"
  43
  44 static TDB_CONTEXT *udevdb;
  45 sig_atomic_t gotalarm;
  46
  47 int udevdb_add_dev(struct udevice *udev)
  48 {
  49         TDB_DATA key, data;
  50         char keystr[SYSFS_PATH_MAX];
  51
  52         if (udevdb == NULL)
  53                 return -1;
  54
  55         memset(keystr, 0x00, SYSFS_PATH_MAX);
  56         strfieldcpy(keystr, udev->devpath);
  57         key.dptr = keystr;
  58         key.dsize = strlen(keystr) + 1;
  59
  60         data.dptr = (void *) udev;
  61         data.dsize = UDEVICE_DB_LEN;
  62         dbg("store key '%s' for device '%s'", keystr, udev->name);
  63
  64         return tdb_store(udevdb, key, data, TDB_REPLACE);
  65 }
  66
  67 int udevdb_get_dev(const char *path, struct udevice *udev)
  68 {
  69         TDB_DATA key, data;
  70
  71         if (udevdb == NULL)
  72                 return -1;
  73
  74         if (path == NULL)
  75                 return -ENODEV;
  76
  77         key.dptr = (void *)path;
  78         key.dsize = strlen(path) + 1;
  79
  80         data = tdb_fetch(udevdb, key);
  81         if (data.dptr == NULL || data.dsize == 0)
  82                 return -ENODEV;
  83
  84         memset(udev, 0x00, sizeof(struct udevice));
  85         memcpy(udev, data.dptr, UDEVICE_DB_LEN);
  86
  87         return 0;
  88 }
  89
  90 int udevdb_delete_dev(const char *path)
  91 {
  92         TDB_DATA key;
  93         char keystr[SYSFS_PATH_MAX];
  94
  95         if (udevdb == NULL)
  96                 return -1;
  97
  98         if (path == NULL)
  99                 return -EINVAL;
 100
 101         memset(keystr, 0, sizeof(keystr));
 102         strfieldcpy(keystr, path);
 103
 104         key.dptr = keystr;
 105         key.dsize = strlen(keystr) + 1;
 106
 107         return tdb_delete(udevdb, key);
 108 }
 109
 110 /**
 111  * udevdb_exit: closes database
 112  */
 113 void udevdb_exit(void)
 114 {
 115         if (udevdb != NULL) {
 116                 tdb_close(udevdb);
 117                 udevdb = NULL;
 118         }
 119 }
 120
 121 /**
 122  * udevdb_init: initializes database
 123  * @init_flag: UDEVDB_INTERNAL - database stays in memory
 124  *             UDEVDB_DEFAULT - database is written to a file
 125  */
 126 int udevdb_init(int init_flag)
 127 {
 128         if (init_flag != UDEVDB_DEFAULT && init_flag != UDEVDB_INTERNAL)
 129                 return -EINVAL;
 130
 131         tdb_set_lock_alarm(&gotalarm);
 132
 133         udevdb = tdb_open(udev_db_filename, 0, init_flag, O_RDWR | O_CREAT, 0644);
 134         if (udevdb == NULL) {
 135                 if (init_flag == UDEVDB_INTERNAL)
 136                         dbg("unable to initialize in-memory database");
 137                 else
 138                         dbg("unable to initialize database at '%s'", udev_db_filename);
 139                 return -EACCES;
 140         }
 141         return 0;
 142 }
 143
 144 /**
 145  * udevdb_open_ro: open database for reading
 146  */
 147 int udevdb_open_ro(void)
 148 {
 149         udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
 150         if (udevdb == NULL) {
 151                 dbg("unable to open database at '%s'", udev_db_filename);
 152                 return -EACCES;
 153         }
 154         return 0;
 155 }
 156
 157 static int (*user_record_callback) (const char *path, struct udevice *dev);
 158
 159 static int traverse_callback(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
 160 {
 161         return user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr);
 162 }
 163
 164 /**
 165  * udevdb_call_foreach: dumps whole database by passing record data to user function
 166  * @user_record_handler: user function called for every record in the database
 167  */
 168 int udevdb_call_foreach(int (*user_record_handler) (const char *path, struct udevice *dev))
 169 {
 170         int retval = 0;
 171
 172         if (udevdb == NULL)
 173                 return -1;
 174
 175         if (user_record_handler == NULL) {
 176                 dbg("invalid user record handling function");
 177                 return -EINVAL;
 178         }
 179         user_record_callback = user_record_handler;
 180         retval = tdb_traverse(udevdb, traverse_callback, NULL);
 181         if (retval < 0)
 182                 return -ENODEV;
 183         else
 184                 return 0;
 185 }
 186
 187 static struct udevice *find_dev;
 188 static char *find_path;
 189 static const char *find_name;
 190 static int find_found;
 191
 192 static int find_device_by_name(const char *path, struct udevice *udev)
 193 {
 194         char *pos;
 195         int len;
 196
 197         if (strncmp(udev->name, find_name, sizeof(udev->name)) == 0) {
 198                 memcpy(find_dev, udev, sizeof(struct udevice));
 199                 strfieldcpymax(find_path, path, NAME_SIZE);
 200                 find_found = 1;
 201                 /* stop search */
 202                 return 1;
 203         }
 204         /* look for matching symlink*/
 205         foreach_strpart(udev->symlink, " ", pos, len) {
 206                 if (strncmp(pos, find_name, len) != 0)
 207                         continue;
 208
 209                 if (len != strlen(find_name))
 210                         continue;
 211
 212                 memcpy(find_dev, udev, sizeof(struct udevice));
 213                 strfieldcpymax(find_path, path, NAME_SIZE);
 214                 find_found = 1;
 215                 return 1;
 216         }
 217         return 0;
 218 }
 219
 220 /**
 221  * udevdb_get_dev_byname: search device with given name by traversing the whole database
 222  */
 223 int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev)
 224 {
 225         find_found = 0;
 226         find_path = path;
 227         find_dev = dev;
 228         find_name = name;
 229         udevdb_call_foreach(find_device_by_name);
 230         if (find_found == 1)
 231                 return 0;
 232         else
 233                 return -1;
 234 }