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 "libsysfs/sysfs/libsysfs.h"
  33 #include "udev.h"
  34 #include "logging.h"
  35 #include "udev_lib.h"
  36 #include "list.h"
  37
  38
  39 char *get_action(void)
  40 {
  41         char *action;
  42
  43         action = getenv("ACTION");
  44         if (action != NULL && strlen(action) > ACTION_SIZE)
  45                 action[ACTION_SIZE-1] = '\0';
  46
  47         return action;
  48 }
  49
  50 char *get_devpath(void)
  51 {
  52         char *devpath;
  53
  54         devpath = getenv("DEVPATH");
  55         if (devpath != NULL && strlen(devpath) > DEVPATH_SIZE)
  56                 devpath[DEVPATH_SIZE-1] = '\0';
  57
  58         return devpath;
  59 }
  60
  61 char *get_devname(void)
  62 {
  63         char *devname;
  64
  65         devname = getenv("DEVNAME");
  66         if (devname != NULL && strlen(devname) > NAME_SIZE)
  67                 devname[NAME_SIZE-1] = '\0';
  68
  69         return devname;
  70 }
  71
  72 char *get_seqnum(void)
  73 {
  74         char *seqnum;
  75
  76         seqnum = getenv("SEQNUM");
  77
  78         return seqnum;
  79 }
  80
  81 char *get_subsystem(char *subsystem)
  82 {
  83         if (subsystem != NULL && strlen(subsystem) > SUBSYSTEM_SIZE)
  84                 subsystem[SUBSYSTEM_SIZE-1] = '\0';
  85
  86         return subsystem;
  87 }
  88
  89 #define BLOCK_PATH              "/block/"
  90 #define CLASS_PATH              "/class/"
  91 #define NET_PATH                "/class/net/"
  92
  93 char get_device_type(const char *path, const char *subsystem)
  94 {
  95         if (strcmp(subsystem, "block") == 0)
  96                 return 'b';
  97
  98         if (strcmp(subsystem, "net") == 0)
  99                 return 'n';
 100
 101         if (strncmp(path, BLOCK_PATH, strlen(BLOCK_PATH)) == 0 &&
 102             strlen(path) > strlen(BLOCK_PATH))
 103                 return 'b';
 104
 105         if (strncmp(path, NET_PATH, strlen(NET_PATH)) == 0 &&
 106             strlen(path) > strlen(NET_PATH))
 107                 return 'n';
 108
 109         if (strncmp(path, CLASS_PATH, strlen(CLASS_PATH)) == 0 &&
 110             strlen(path) > strlen(CLASS_PATH))
 111                 return 'c';
 112
 113         return '\0';
 114 }
 115
 116 int file_map(const char *filename, char **buf, size_t *bufsize)
 117 {
 118         struct stat stats;
 119         int fd;
 120
 121         fd = open(filename, O_RDONLY);
 122         if (fd < 0) {
 123                 return -1;
 124         }
 125
 126         if (fstat(fd, &stats) < 0) {
 127                 close(fd);
 128                 return -1;
 129         }
 130
 131         *buf = mmap(NULL, stats.st_size, PROT_READ, MAP_SHARED, fd, 0);
 132         if (*buf == MAP_FAILED) {
 133                 close(fd);
 134                 return -1;
 135         }
 136         *bufsize = stats.st_size;
 137
 138         close(fd);
 139
 140         return 0;
 141 }
 142
 143 void file_unmap(char *buf, size_t bufsize)
 144 {
 145         munmap(buf, bufsize);
 146 }
 147
 148 size_t buf_get_line(char *buf, size_t buflen, size_t cur)
 149 {
 150         size_t count = 0;
 151
 152         for (count = cur; count < buflen && buf[count] != '\n'; count++);
 153
 154         return count - cur;
 155 }
 156
 157 void leading_slash(char *path)
 158 {
 159         int len;
 160
 161         len = strlen(path);
 162         if (len > 0 && path[len-1] != '/') {
 163                 path[len] = '/';
 164                 path[len+1] = '\0';
 165         }
 166 }
 167
 168 void no_leading_slash(char *path)
 169 {
 170         int len;
 171
 172         len = strlen(path);
 173         if (len > 0 && path[len-1] == '/')
 174                 path[len-1] = '\0';
 175 }
 176
 177 struct files {
 178         struct list_head list;
 179         char name[NAME_SIZE];
 180 };
 181
 182 /* sort files in lexical order */
 183 static int file_list_insert(char *filename, struct list_head *file_list)
 184 {
 185         struct files *loop_file;
 186         struct files *new_file;
 187
 188         list_for_each_entry(loop_file, file_list, list) {
 189                 if (strcmp(loop_file->name, filename) > 0) {
 190                         break;
 191                 }
 192         }
 193
 194         new_file = malloc(sizeof(struct files));
 195         if (new_file == NULL) {
 196                 dbg("error malloc");
 197                 return -ENOMEM;
 198         }
 199
 200         strfieldcpy(new_file->name, filename);
 201         list_add_tail(&new_file->list, &loop_file->list);
 202         return 0;
 203 }
 204
 205 /* calls function for every file found in specified directory */
 206 int call_foreach_file(int fnct(char *f) , char *dirname, char *suffix)
 207 {
 208         struct dirent *ent;
 209         DIR *dir;
 210         char *ext;
 211         char file[NAME_SIZE];
 212         struct files *loop_file;
 213         struct files *tmp_file;
 214         LIST_HEAD(file_list);
 215
 216         dbg("open directory '%s'", dirname);
 217         dir = opendir(dirname);
 218         if (dir == NULL) {
 219                 dbg("unable to open '%s'", dirname);
 220                 return -1;
 221         }
 222
 223         while (1) {
 224                 ent = readdir(dir);
 225                 if (ent == NULL || ent->d_name[0] == '\0')
 226                         break;
 227
 228                 if ((ent->d_name[0] == '.') || (ent->d_name[0] == COMMENT_CHARACTER))
 229                         continue;
 230
 231                 /* look for file with specified suffix */
 232                 ext = strrchr(ent->d_name, '.');
 233                 if (ext == NULL)
 234                         continue;
 235
 236                 if (strcmp(ext, suffix) != 0)
 237                         continue;
 238
 239                 dbg("put file '%s/%s' in list", dirname, ent->d_name);
 240                 file_list_insert(ent->d_name, &file_list);
 241         }
 242
 243         /* call function for every file in the list */
 244         list_for_each_entry_safe(loop_file, tmp_file, &file_list, list) {
 245                 strfieldcpy(file, dirname);
 246                 strfieldcat(file, "/");
 247                 strfieldcat(file, loop_file->name);
 248
 249                 fnct(file);
 250
 251                 list_del(&loop_file->list);
 252                 free(loop_file);
 253         }
 254
 255         closedir(dir);
 256         return 0;
 257 }
 258
 259 /* Set the FD_CLOEXEC  flag of desc if value is nonzero,
 260    or clear the flag if value is 0.
 261    Return 0 on success, or -1 on error with errno  set. */
 262
 263 int set_cloexec_flag (int desc, int value)
 264 {
 265         int oldflags = fcntl (desc, F_GETFD, 0);
 266         /* If reading the flags failed, return error indication now. */
 267         if (oldflags < 0)
 268                 return oldflags;
 269         /* Set just the flag we want to set. */
 270         if (value != 0)
 271                 oldflags |= FD_CLOEXEC;
 272         else
 273                 oldflags &= ~FD_CLOEXEC;
 274         /* Store modified flag word in the descriptor. */
 275         return fcntl (desc, F_SETFD, oldflags);
 276 }