udevdb.c

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