udev_lib.c

   1 /*
   2  * udev_lib - generic stuff used by udev
   3  *
   4  * Copyright (C) 2004 Kay Sievers <kay@vrfy.org>
   5  *
   6  *      This program is free software; you can redistribute it and/or modify it
   7  *      under the terms of the GNU General Public License as published by the
   8  *      Free Software Foundation version 2 of the License.
   9  *
  10  *      This program is distributed in the hope that it will be useful, but
  11  *      WITHOUT ANY WARRANTY; without even the implied warranty of
  12  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  *      General Public License for more details.
  14  *
  15  *      You should have received a copy of the GNU General Public License along
  16  *      with this program; if not, write to the Free Software Foundation, Inc.,
  17  *      675 Mass Ave, Cambridge, MA 02139, USA.
  18  *
  19  */
  20
  21
  22 #include <stdlib.h>
  23 #include <stdio.h>
  24 #include <stddef.h>
  25 #include <unistd.h>
  26 #include <fcntl.h>
  27 #include <errno.h>
  28 #include <dirent.h>
  29 #include <sys/stat.h>
  30 #include <sys/mman.h>
  31
  32 #include "udev.h"
  33 #include "logging.h"
  34 #include "udev_lib.h"
  35 #include "list.h"
  36
  37
  38 char *get_action(void)
  39 {
  40         char *action;
  41
  42         action = getenv("ACTION");
  43         if (action != NULL && strlen(action) > ACTION_SIZE)
  44                 action[ACTION_SIZE-1] = '\0';
  45
  46         return action;
  47 }
  48
  49 char *get_devpath(void)
  50 {
  51         char *devpath;
  52
  53         devpath = getenv("DEVPATH");
  54         if (devpath != NULL && strlen(devpath) > DEVPATH_SIZE)
  55                 devpath[DEVPATH_SIZE-1] = '\0';
  56
  57         return devpath;
  58 }
  59
  60 char *get_devname(void)
  61 {
  62         char *devname;
  63
  64         devname = getenv("DEVNAME");
  65         if (devname != NULL && strlen(devname) > NAME_SIZE)
  66                 devname[NAME_SIZE-1] = '\0';
  67
  68         return devname;
  69 }
  70
  71 char *get_seqnum(void)
  72 {
  73         char *seqnum;
  74
  75         seqnum = getenv("SEQNUM");
  76
  77         return seqnum;
  78 }
  79
  80 char *get_subsystem(char *subsystem)
  81 {
  82         if (subsystem != NULL && strlen(subsystem) > SUBSYSTEM_SIZE)
  83                 subsystem[SUBSYSTEM_SIZE-1] = '\0';
  84
  85         return subsystem;
  86 }
  87
  88 #define BLOCK_PATH              "/block/"
  89 #define CLASS_PATH              "/class/"
  90 #define NET_PATH                "/class/net/"
  91
  92 char get_device_type(const char *path, const char *subsystem)
  93 {
  94         if (strcmp(subsystem, "block") == 0)
  95                 return 'b';
  96
  97         if (strcmp(subsystem, "net") == 0)
  98                 return 'n';
  99
 100         if (strncmp(path, BLOCK_PATH, strlen(BLOCK_PATH)) == 0 &&
 101             strlen(path) > strlen(BLOCK_PATH))
 102                 return 'b';
 103
 104         if (strncmp(path, NET_PATH, strlen(NET_PATH)) == 0 &&
 105             strlen(path) > strlen(NET_PATH))
 106                 return 'n';
 107
 108         if (strncmp(path, CLASS_PATH, strlen(CLASS_PATH)) == 0 &&
 109             strlen(path) > strlen(CLASS_PATH))
 110                 return 'c';
 111
 112         return '\0';
 113 }
 114
 115 void udev_set_values(struct udevice *udev, const char* devpath, const char *subsystem)
 116 {
 117         memset(udev, 0x00, sizeof(struct udevice));
 118         strfieldcpy(udev->devpath, devpath);
 119         strfieldcpy(udev->subsystem, subsystem);
 120         udev->type = get_device_type(devpath, subsystem);
 121 }
 122
 123 int file_map(const char *filename, char **buf, size_t *bufsize)
 124 {
 125         struct stat stats;
 126         int fd;
 127
 128         fd = open(filename, O_RDONLY);
 129         if (fd < 0) {
 130                 return -1;
 131         }
 132
 133         if (fstat(fd, &stats) < 0) {
 134                 close(fd);
 135                 return -1;
 136         }
 137
 138         *buf = mmap(NULL, stats.st_size, PROT_READ, MAP_SHARED, fd, 0);
 139         if (*buf == MAP_FAILED) {
 140                 close(fd);
 141                 return -1;
 142         }
 143         *bufsize = stats.st_size;
 144
 145         close(fd);
 146
 147         return 0;
 148 }
 149
 150 void file_unmap(char *buf, size_t bufsize)
 151 {
 152         munmap(buf, bufsize);
 153 }
 154
 155 size_t buf_get_line(char *buf, size_t buflen, size_t cur)
 156 {
 157         size_t count = 0;
 158
 159         for (count = cur; count < buflen && buf[count] != '\n'; count++);
 160
 161         return count - cur;
 162 }
 163
 164 void leading_slash(char *path)
 165 {
 166         int len;
 167
 168         len = strlen(path);
 169         if (len > 0 && path[len-1] != '/') {
 170                 path[len] = '/';
 171                 path[len+1] = '\0';
 172         }
 173 }
 174
 175 void no_leading_slash(char *path)
 176 {
 177         int len;
 178
 179         len = strlen(path);
 180         if (len > 0 && path[len-1] == '/')
 181                 path[len-1] = '\0';
 182 }
 183
 184 struct files {
 185         struct list_head list;
 186         char name[NAME_SIZE];
 187 };
 188
 189 /* sort files in lexical order */
 190 static int file_list_insert(char *filename, struct list_head *file_list)
 191 {
 192         struct files *loop_file;
 193         struct files *new_file;
 194
 195         list_for_each_entry(loop_file, file_list, list) {
 196                 if (strcmp(loop_file->name, filename) > 0) {
 197                         break;
 198                 }
 199         }
 200
 201         new_file = malloc(sizeof(struct files));
 202         if (new_file == NULL) {
 203                 dbg("error malloc");
 204                 return -ENOMEM;
 205         }
 206
 207         strfieldcpy(new_file->name, filename);
 208         list_add_tail(&new_file->list, &loop_file->list);
 209         return 0;
 210 }
 211
 212 /* calls function for every file found in specified directory */
 213 int call_foreach_file(int fnct(char *f) , char *dirname, char *suffix)
 214 {
 215         struct dirent *ent;
 216         DIR *dir;
 217         char *ext;
 218         char file[NAME_SIZE];
 219         struct files *loop_file;
 220         struct files *tmp_file;
 221         LIST_HEAD(file_list);
 222
 223         dbg("open directory '%s'", dirname);
 224         dir = opendir(dirname);
 225         if (dir == NULL) {
 226                 dbg("unable to open '%s'", dirname);
 227                 return -1;
 228         }
 229
 230         while (1) {
 231                 ent = readdir(dir);
 232                 if (ent == NULL || ent->d_name[0] == '\0')
 233                         break;
 234
 235                 if ((ent->d_name[0] == '.') || (ent->d_name[0] == COMMENT_CHARACTER))
 236                         continue;
 237
 238                 /* look for file with specified suffix */
 239                 ext = strrchr(ent->d_name, '.');
 240                 if (ext == NULL)
 241                         continue;
 242
 243                 if (strcmp(ext, suffix) != 0)
 244                         continue;
 245
 246                 dbg("put file '%s/%s' in list", dirname, ent->d_name);
 247                 file_list_insert(ent->d_name, &file_list);
 248         }
 249
 250         /* call function for every file in the list */
 251         list_for_each_entry_safe(loop_file, tmp_file, &file_list, list) {
 252                 strfieldcpy(file, dirname);
 253                 strfieldcat(file, "/");
 254                 strfieldcat(file, loop_file->name);
 255
 256                 fnct(file);
 257
 258                 list_del(&loop_file->list);
 259                 free(loop_file);
 260         }
 261
 262         closedir(dir);
 263         return 0;
 264 }
 265
 266 /* Set the FD_CLOEXEC  flag of desc if value is nonzero,
 267    or clear the flag if value is 0.
 268    Return 0 on success, or -1 on error with errno  set. */
 269
 270 int set_cloexec_flag (int desc, int value)
 271 {
 272         int oldflags = fcntl (desc, F_GETFD, 0);
 273         /* If reading the flags failed, return error indication now. */
 274         if (oldflags < 0)
 275                 return oldflags;
 276         /* Set just the flag we want to set. */
 277         if (value != 0)
 278                 oldflags |= FD_CLOEXEC;
 279         else
 280                 oldflags &= ~FD_CLOEXEC;
 281         /* Store modified flag word in the descriptor. */
 282         return fcntl (desc, F_SETFD, oldflags);
 283 }