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 = UDEVICE_LEN;
  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         memset(dev, 0, sizeof(struct udevice));
  81         memcpy(dev, data.dptr, UDEVICE_LEN);
  82         return 0;
  83 }
  84
  85 int udevdb_delete_dev(const char *path)
  86 {
  87         TDB_DATA key;
  88         char keystr[SYSFS_PATH_MAX];
  89
  90         if (path == NULL)
  91                 return -EINVAL;
  92
  93         memset(keystr, 0, sizeof(keystr));
  94         strcpy(keystr, path);
  95
  96         key.dptr = keystr;
  97         key.dsize = strlen(keystr) + 1;
  98
  99         return tdb_delete(udevdb, key);
 100 }
 101
 102 /**
 103  * udevdb_exit: closes database
 104  */
 105 void udevdb_exit(void)
 106 {
 107         if (udevdb != NULL) {
 108                 tdb_close(udevdb);
 109                 udevdb = NULL;
 110         }
 111 }
 112
 113 /**
 114  * udevdb_init: initializes database
 115  * @init_flag: UDEVDB_INTERNAL - database stays in memory
 116  *             UDEVDB_DEFAULT - database is written to a file
 117  */
 118 int udevdb_init(int init_flag)
 119 {
 120         if (init_flag != UDEVDB_DEFAULT && init_flag != UDEVDB_INTERNAL)
 121                 return -EINVAL;
 122
 123         udevdb = tdb_open(udev_db_filename, 0, init_flag, O_RDWR | O_CREAT, 0644);
 124         if (udevdb == NULL) {
 125                 if (init_flag == UDEVDB_INTERNAL)
 126                         dbg("unable to initialize in-memory database");
 127                 else
 128                         dbg("unable to initialize database at '%s'", udev_db_filename);
 129                 return -EACCES;
 130         }
 131         return 0;
 132 }
 133
 134 /**
 135  * udevdb_open_ro: open database for reading
 136  */
 137 int udevdb_open_ro(void)
 138 {
 139         udevdb = tdb_open(udev_db_filename, 0, 0, O_RDONLY, 0);
 140         if (udevdb == NULL) {
 141                 dbg("unable to open database at '%s'", udev_db_filename);
 142                 return -EACCES;
 143         }
 144         return 0;
 145 }
 146
 147 static int (*user_record_callback) (char *path, struct udevice *dev);
 148
 149 static int traverse_callback(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, void *state)
 150 {
 151         return user_record_callback((char*) key.dptr, (struct udevice*) dbuf.dptr);
 152 }
 153
 154 /**
 155  * udevdb_call_foreach: dumps whole database by passing record data to user function
 156  * @user_record_handler: user function called for every record in the database
 157  */
 158 int udevdb_call_foreach(int (*user_record_handler) (char *path, struct udevice *dev))
 159 {
 160         int retval = 0;
 161
 162         if (user_record_handler == NULL) {
 163                 dbg("invalid user record handling function");
 164                 return -EINVAL;
 165         }
 166         user_record_callback = user_record_handler;
 167         retval = tdb_traverse(udevdb, traverse_callback, NULL);
 168         if (retval < 0)
 169                 return -ENODEV;
 170         else
 171                 return 0;
 172 }
 173
 174 static struct udevice *find_dev;
 175 static char *find_path;
 176 static const char *find_name;
 177 static int find_found;
 178
 179 static int find_device_by_name(char *path, struct udevice *dev)
 180 {
 181         if (strncmp(dev->name, find_name, sizeof(dev->name)) == 0) {
 182                 memcpy(find_dev, dev, sizeof(*find_dev));
 183                 strncpy(find_path, path, NAME_SIZE);
 184                 find_found = 1;
 185                 /* stop search */
 186                 return 1;
 187         }
 188         return 0;
 189 }
 190
 191 /**
 192  * udevdb_get_dev_byname: search device with given name by traversing the whole database
 193  */
 194 int udevdb_get_dev_byname(const char *name, char *path, struct udevice *dev)
 195 {
 196         find_found = 0;
 197         find_path = path;
 198         find_dev = dev;
 199         find_name = name;
 200         udevdb_call_foreach(find_device_by_name);
 201         if (find_found == 1)
 202                 return 0;
 203         else
 204                 return -1;
 205 }