udev/lib/libudev-queue.c

   1 /*
   2  * libudev - interface to udev device information
   3  *
   4  * Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <stdio.h>
  21 #include <stdlib.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <dirent.h>
  27 #include <fcntl.h>
  28 #include <sys/stat.h>
  29
  30 #include "libudev.h"
  31 #include "libudev-private.h"
  32
  33 struct udev_queue {
  34         struct udev *udev;
  35         int refcount;
  36         unsigned long long int last_seen_udev_seqnum;
  37         struct udev_list_node queue_list;
  38         struct udev_list_node failed_list;
  39 };
  40
  41 struct udev_queue *udev_queue_new(struct udev *udev)
  42 {
  43         struct udev_queue *udev_queue;
  44
  45         if (udev == NULL)
  46                 return NULL;
  47
  48         udev_queue = calloc(1, sizeof(struct udev_queue));
  49         if (udev_queue == NULL)
  50                 return NULL;
  51         udev_queue->refcount = 1;
  52         udev_queue->udev = udev;
  53         udev_list_init(&udev_queue->queue_list);
  54         udev_list_init(&udev_queue->failed_list);
  55         return udev_queue;
  56 }
  57
  58 struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue)
  59 {
  60         if (udev_queue == NULL)
  61                 return NULL;
  62         udev_queue->refcount++;
  63         return udev_queue;
  64 }
  65
  66 void udev_queue_unref(struct udev_queue *udev_queue)
  67 {
  68         if (udev_queue == NULL)
  69                 return;
  70         udev_queue->refcount--;
  71         if (udev_queue->refcount > 0)
  72                 return;
  73         udev_list_cleanup_entries(udev_queue->udev, &udev_queue->queue_list);
  74         udev_list_cleanup_entries(udev_queue->udev, &udev_queue->failed_list);
  75         free(udev_queue);
  76 }
  77
  78 struct udev *udev_queue_get_udev(struct udev_queue *udev_queue)
  79 {
  80         if (udev_queue == NULL)
  81                 return NULL;
  82         return udev_queue->udev;
  83 }
  84
  85 unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
  86 {
  87         char filename[UTIL_PATH_SIZE];
  88         unsigned long long int seqnum;
  89         int fd;
  90         char buf[32];
  91         ssize_t len;
  92
  93         if (udev_queue == NULL)
  94                 return -EINVAL;
  95         util_strlcpy(filename, udev_get_sys_path(udev_queue->udev), sizeof(filename));
  96         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
  97         fd = open(filename, O_RDONLY);
  98         if (fd < 0)
  99                 return 0;
 100         len = read(fd, buf, sizeof(buf));
 101         close(fd);
 102         if (len <= 2)
 103                 return 0;
 104         buf[len-1] = '\0';
 105         seqnum = strtoull(buf, NULL, 10);
 106         dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
 107         return seqnum;
 108 }
 109
 110 unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
 111 {
 112         char filename[UTIL_PATH_SIZE];
 113         unsigned long long int seqnum;
 114         int fd;
 115         char buf[32];
 116         ssize_t len;
 117
 118         if (udev_queue == NULL)
 119                 return -EINVAL;
 120         util_strlcpy(filename, udev_get_dev_path(udev_queue->udev), sizeof(filename));
 121         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 122         fd = open(filename, O_RDONLY);
 123         if (fd < 0)
 124                 return 0;
 125         len = read(fd, buf, sizeof(buf));
 126         close(fd);
 127         if (len <= 2)
 128                 return 0;
 129         buf[len-1] = '\0';
 130         seqnum = strtoull(buf, NULL, 10);
 131         dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
 132         udev_queue->last_seen_udev_seqnum = seqnum;
 133         return seqnum;
 134 }
 135
 136 int udev_queue_get_udev_is_active(struct udev_queue *udev_queue)
 137 {
 138         char filename[UTIL_PATH_SIZE];
 139         struct stat statbuf;
 140
 141         if (udev_queue == NULL)
 142                 return 0;
 143         util_strlcpy(filename, udev_get_dev_path(udev_queue->udev), sizeof(filename));
 144         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 145         if (stat(filename, &statbuf) == 0)
 146                 return 1;
 147         return 0;
 148 }
 149
 150 int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
 151 {
 152         char queuename[UTIL_PATH_SIZE];
 153         struct stat statbuf;
 154         unsigned long long int seqnum_kernel;
 155
 156         if (udev_queue == NULL)
 157                 return -EINVAL;
 158         util_strlcpy(queuename, udev_get_dev_path(udev_queue->udev), sizeof(queuename));
 159         util_strlcat(queuename, "/.udev/queue", sizeof(queuename));
 160         if (stat(queuename, &statbuf) == 0) {
 161                 dbg(udev_queue->udev, "queue is not empty\n");
 162                 return 0;
 163         }
 164         seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
 165         if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
 166                 dbg(udev_queue->udev, "queue is empty\n");
 167                 return 1;
 168         }
 169         /* update udev seqnum, and check if udev is still running */
 170         if (udev_queue_get_udev_seqnum(udev_queue) == 0)
 171                 if (!udev_queue_get_udev_is_active(udev_queue))
 172                         return 1;
 173         if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
 174                 dbg(udev_queue->udev, "queue is empty\n");
 175                 return 1;
 176         }
 177         dbg(udev_queue->udev, "queue is empty, but kernel events still pending [%llu]<->[%llu]\n",
 178              seqnum_kernel, udev_queue->last_seen_udev_seqnum);
 179         return 0;
 180 }
 181
 182 int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
 183 {
 184         char filename[UTIL_PATH_SIZE];
 185         struct stat statbuf;
 186
 187         if (udev_queue == NULL)
 188                 return -EINVAL;
 189         /* if we have not seen this seqnum, check if it is/was already queued */
 190         if (seqnum < udev_queue->last_seen_udev_seqnum) {
 191                 udev_queue_get_udev_seqnum(udev_queue);
 192                 if (seqnum < udev_queue->last_seen_udev_seqnum)
 193                         return 0;
 194         }
 195         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 196                  udev_get_dev_path(udev_queue->udev), seqnum);
 197         if (stat(filename, &statbuf) == 0)
 198                 return 0;
 199         dbg(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
 200         return 1;
 201 }
 202
 203 struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
 204 {
 205         char path[UTIL_PATH_SIZE];
 206         DIR *dir;
 207         struct dirent *dent;
 208
 209         if (udev_queue == NULL)
 210                 return NULL;
 211         udev_list_cleanup_entries(udev_queue->udev, &udev_queue->queue_list);
 212         util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
 213         util_strlcat(path, "/.udev/queue", sizeof(path));
 214         dir = opendir(path);
 215         if (dir == NULL)
 216                 return NULL;
 217         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 218                 char filename[UTIL_PATH_SIZE];
 219                 char syspath[UTIL_PATH_SIZE];
 220                 size_t syslen;
 221                 ssize_t len;
 222
 223                 if (dent->d_name[0] == '.')
 224                         continue;
 225                 util_strlcpy(filename, path, sizeof(filename));
 226                 util_strlcat(filename, "/", sizeof(filename));
 227                 util_strlcat(filename, dent->d_name, sizeof(filename));
 228
 229                 syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
 230                 len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
 231                 if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
 232                         continue;
 233                 syspath[syslen + len] = '\0';
 234                 dbg(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
 235                 udev_list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, dent->d_name, 0, 0);
 236         }
 237         closedir(dir);
 238         return udev_list_get_entry(&udev_queue->queue_list);
 239 }
 240
 241 struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue)
 242 {
 243         char path[UTIL_PATH_SIZE];
 244         DIR *dir;
 245         struct dirent *dent;
 246
 247         if (udev_queue == NULL)
 248                 return NULL;
 249         udev_list_cleanup_entries(udev_queue->udev, &udev_queue->failed_list);
 250         util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
 251         util_strlcat(path, "/.udev/failed", sizeof(path));
 252         dir = opendir(path);
 253         if (dir == NULL)
 254                 return NULL;
 255         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 256                 char filename[UTIL_PATH_SIZE];
 257                 char syspath[UTIL_PATH_SIZE];
 258                 struct stat statbuf;
 259                 size_t syslen;
 260                 ssize_t len;
 261
 262                 if (dent->d_name[0] == '.')
 263                         continue;
 264                 util_strlcpy(filename, path, sizeof(filename));
 265                 util_strlcat(filename, "/", sizeof(filename));
 266                 util_strlcat(filename, dent->d_name, sizeof(filename));
 267
 268                 syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
 269                 len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
 270                 if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
 271                         continue;
 272                 syspath[syslen + len] = '\0';
 273                 dbg(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
 274                 util_strlcpy(filename, syspath, sizeof(filename));
 275                 util_strlcat(filename, "/uevent", sizeof(filename));
 276                 if (stat(filename, &statbuf) != 0)
 277                         continue;
 278                 udev_list_entry_add(udev_queue->udev, &udev_queue->failed_list, syspath, NULL, 0, 0);
 279         }
 280         closedir(dir);
 281         return udev_list_get_entry(&udev_queue->failed_list);
 282 }
 283
 284 int udev_queue_export_udev_seqnum(struct udev_queue *udev_queue, unsigned long long int seqnum)
 285 {
 286         return -1;
 287 }
 288
 289 extern int udev_queue_export_device_queued(struct udev_queue *udev_queue, struct udev_device *udev_device)
 290 {
 291         return -1;
 292 }
 293
 294 extern int udev_queue_export_device_finished(struct udev_queue *udev_queue, struct udev_device *udev_device)
 295 {
 296         return -1;
 297 }
 298
 299 extern int udev_queue_export_device_failed(struct udev_queue *udev_queue, struct udev_device *udev_device)
 300 {
 301         return -1;
 302 }