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