udev-add.c

   1 /*
   2  * udev-add.c
   3  *
   4  * Userspace devfs
   5  *
   6  * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
   7  *
   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 <string.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include <unistd.h>
  29 #include <errno.h>
  30 #include <sys/stat.h>
  31 #include <sys/types.h>
  32 #include <grp.h>
  33 #ifndef __KLIBC__
  34 #include <pwd.h>
  35 #endif
  36
  37 #include "udev.h"
  38 #include "udev_version.h"
  39 #include "udev_dbus.h"
  40 #include "namedev.h"
  41 #include "udevdb.h"
  42 #include "libsysfs/libsysfs.h"
  43 #include "klibc_fixups.h"
  44
  45 /*
  46  * Right now the major/minor of a device is stored in a file called
  47  * "dev" in sysfs.
  48  * The number is stored as:
  49  *      MM:mm
  50  *              MM is the major
  51  *              mm is the minor
  52  *              The value is in decimal.
  53  */
  54 static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
  55 {
  56         int retval = -ENODEV;
  57         struct sysfs_attribute *attr = NULL;
  58
  59         attr = sysfs_get_classdev_attr(class_dev, "dev");
  60         if (attr == NULL)
  61                 goto exit;
  62         dbg("dev='%s'", attr->value);
  63
  64         if (sscanf(attr->value, "%u:%u", &udev->major, &udev->minor) != 2)
  65                 goto exit;
  66         dbg("found major=%d, minor=%d", udev->major, udev->minor);
  67
  68         retval = 0;
  69 exit:
  70         return retval;
  71 }
  72
  73 static int create_path(char *file)
  74 {
  75         char p[NAME_SIZE];
  76         char *pos;
  77         int retval;
  78         struct stat stats;
  79
  80         strncpy(p, file, sizeof(p));
  81         pos = strchr(p+1, '/');
  82         while (1) {
  83                 pos = strchr(pos+1, '/');
  84                 if (pos == NULL)
  85                         break;
  86                 *pos = 0x00;
  87                 if (stat(p, &stats)) {
  88                         retval = mkdir(p, 0755);
  89                         if (retval) {
  90                                 dbg("mkdir(%s) failed with error '%s'",
  91                                     p, strerror(errno));
  92                                 return retval;
  93                         }
  94                         dbg("created '%s'", p);
  95                 }
  96                 *pos = '/';
  97         }
  98         return 0;
  99 }
 100
 101 static int create_node(struct udevice *dev)
 102 {
 103         char filename[255];
 104         char linktarget[255];
 105         char *linkname;
 106         char *symlinks;
 107         int retval = 0;
 108         uid_t uid = 0;
 109         gid_t gid = 0;
 110         dev_t res;
 111         int i;
 112         int tail;
 113
 114         strncpy(filename, udev_root, sizeof(filename));
 115         strncat(filename, dev->name, sizeof(filename));
 116
 117 #ifdef __KLIBC__
 118         res = (dev->major << 8) | (dev->minor);
 119 #else
 120         res = makedev(dev->major, dev->minor);
 121 #endif
 122
 123         switch (dev->type) {
 124         case 'b':
 125                 dev->mode |= S_IFBLK;
 126                 break;
 127         case 'c':
 128         case 'u':
 129                 dev->mode |= S_IFCHR;
 130                 break;
 131         case 'p':
 132                 dev->mode |= S_IFIFO;
 133                 break;
 134         default:
 135                 dbg("unknown node type %c\n", dev->type);
 136                 return -EINVAL;
 137         }
 138
 139         /* create parent directories if needed */
 140         if (strrchr(dev->name, '/'))
 141                 create_path(filename);
 142
 143         dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
 144         retval = mknod(filename, dev->mode, res);
 145         if (retval)
 146                 dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
 147                     filename, dev->mode, dev->major, dev->minor, strerror(errno));
 148
 149         dbg("chmod(%s, %#o)", filename, dev->mode);
 150         retval = chmod(filename, dev->mode);
 151         if (retval)
 152                 dbg("chmod(%s, %#o) failed with error '%s'",
 153                     filename, dev->mode, strerror(errno));
 154
 155         if (*dev->owner) {
 156                 char *endptr;
 157                 unsigned long id = strtoul(dev->owner, &endptr, 10);
 158                 if (*endptr == 0x00)
 159                         uid = (uid_t) id;
 160                 else {
 161                         struct passwd *pw = getpwnam(dev->owner);
 162                         if (!pw)
 163                                 dbg("user unknown '%s'", dev->owner);
 164                         else
 165                                 uid = pw->pw_uid;
 166                 }
 167         }
 168
 169         if (*dev->group) {
 170                 char *endptr;
 171                 unsigned long id = strtoul(dev->group, &endptr, 10);
 172                 if (*endptr == 0x00)
 173                         gid = (gid_t) id;
 174                 else {
 175                         struct group *gr = getgrnam(dev->group);
 176                         if (!gr)
 177                                 dbg("group unknown '%s'", dev->group);
 178                         else
 179                                 gid = gr->gr_gid;
 180                 }
 181         }
 182
 183         if (uid || gid) {
 184                 dbg("chown(%s, %u, %u)", filename, uid, gid);
 185                 retval = chown(filename, uid, gid);
 186                 if (retval)
 187                         dbg("chown(%s, %u, %u) failed with error '%s'",
 188                             filename, uid, gid, strerror(errno));
 189         }
 190
 191         /* create symlink if requested */
 192         if (*dev->symlink) {
 193                 symlinks = dev->symlink;
 194                 while (1) {
 195                         linkname = strsep(&symlinks, " ");
 196                         if (linkname == NULL)
 197                                 break;
 198
 199                         strncpy(filename, udev_root, sizeof(filename));
 200                         strncat(filename, linkname, sizeof(filename));
 201                         dbg("symlink '%s' to node '%s' requested", filename, dev->name);
 202                         if (strrchr(linkname, '/'))
 203                                 create_path(filename);
 204
 205                         /* optimize relative link */
 206                         linktarget[0] = '\0';
 207                         i = 0;
 208                         tail = 0;
 209                         while ((dev->name[i] == linkname[i]) && dev->name[i]) {
 210                                 if (dev->name[i] == '/')
 211                                         tail = i+1;
 212                                 i++;
 213                         }
 214                         while (linkname[i]) {
 215                                 if (linkname[i] == '/')
 216                                         strcat(linktarget, "../");
 217                                 i++;
 218                         }
 219
 220                         if (*linktarget == '\0')
 221                                 strcpy(linktarget, "./");
 222                         strcat(linktarget, &dev->name[tail]);
 223
 224                         dbg("symlink(%s, %s)", linktarget, filename);
 225                         retval = symlink(linktarget, filename);
 226                         if (retval)
 227                                 dbg("symlink(%s, %s) failed with error '%s'",
 228                                     linktarget, filename, strerror(errno));
 229                 }
 230         }
 231
 232         return retval;
 233 }
 234
 235 static struct sysfs_class_device *get_class_dev(char *device_name)
 236 {
 237         char dev_path[SYSFS_PATH_MAX];
 238         struct sysfs_class_device *class_dev = NULL;
 239
 240         strcpy(dev_path, sysfs_path);
 241         strcat(dev_path, device_name);
 242         dbg("looking at '%s'", dev_path);
 243
 244         /* open up the sysfs class device for this thing... */
 245         class_dev = sysfs_open_class_device(dev_path);
 246         if (class_dev == NULL) {
 247                 dbg ("sysfs_open_class_device failed");
 248                 goto exit;
 249         }
 250         dbg("class_dev->name='%s'", class_dev->name);
 251
 252 exit:
 253         return class_dev;
 254 }
 255
 256 /* wait for the "dev" file to show up in the directory in sysfs.
 257  * If it doesn't happen in about 10 seconds, give up.
 258  */
 259 #define SECONDS_TO_WAIT_FOR_DEV         10
 260 static int sleep_for_dev(char *path)
 261 {
 262         char filename[SYSFS_PATH_MAX + 6];
 263         int loop = SECONDS_TO_WAIT_FOR_DEV;
 264         int retval;
 265
 266         strcpy(filename, sysfs_path);
 267         strcat(filename, path);
 268         strcat(filename, "/dev");
 269
 270         while (loop--) {
 271                 struct stat buf;
 272
 273                 dbg("looking for '%s'", filename);
 274                 retval = stat(filename, &buf);
 275                 if (!retval)
 276                         goto exit;
 277
 278                 /* sleep to give the kernel a chance to create the dev file */
 279                 sleep(1);
 280         }
 281         retval = -ENODEV;
 282 exit:
 283         return retval;
 284 }
 285
 286 int udev_add_device(char *path, char *subsystem)
 287 {
 288         struct sysfs_class_device *class_dev = NULL;
 289         struct udevice dev;
 290         int retval = -EINVAL;
 291
 292         memset(&dev, 0x00, sizeof(dev));
 293
 294         /* for now, the block layer is the only place where block devices are */
 295         if (strcmp(subsystem, "block") == 0)
 296                 dev.type = 'b';
 297         else
 298                 dev.type = 'c';
 299
 300         retval = sleep_for_dev(path);
 301         if (retval)
 302                 goto exit;
 303
 304         class_dev = get_class_dev(path);
 305         if (class_dev == NULL)
 306                 goto exit;
 307
 308         retval = get_major_minor(class_dev, &dev);
 309         if (retval) {
 310                 dbg("get_major_minor failed");
 311                 goto exit;
 312         }
 313
 314         retval = namedev_name_device(class_dev, &dev);
 315         if (retval)
 316                 goto exit;
 317
 318         retval = udevdb_add_dev(path, &dev);
 319         if (retval != 0)
 320                 dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. "
 321                     "But remove might not work properly for this device.");
 322
 323         dbg("name='%s'", dev.name);
 324         retval = create_node(&dev);
 325
 326         if (retval == 0)
 327                 sysbus_send_create(&dev, path);
 328
 329 exit:
 330         if (class_dev)
 331                 sysfs_close_class_device(class_dev);
 332
 333         return retval;
 334 }