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 = malloc(sizeof(struct udev_queue));
  49         if (udev_queue == NULL)
  50                 return NULL;
  51         memset(udev_queue, 0x00, sizeof(struct udev_queue));
  52         udev_queue->refcount = 1;
  53         udev_queue->udev = udev;
  54         udev_list_init(&udev_queue->queue_list);
  55         udev_list_init(&udev_queue->failed_list);
  56         return udev_queue;
  57 }
  58
  59 struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue)
  60 {
  61         if (udev_queue == NULL)
  62                 return NULL;
  63         udev_queue->refcount++;
  64         return udev_queue;
  65 }
  66
  67 void udev_queue_unref(struct udev_queue *udev_queue)
  68 {
  69         if (udev_queue == NULL)
  70                 return;
  71         udev_queue->refcount--;
  72         if (udev_queue->refcount > 0)
  73                 return;
  74         udev_list_cleanup(udev_queue->udev, &udev_queue->queue_list);
  75         udev_list_cleanup(udev_queue->udev, &udev_queue->failed_list);
  76         free(udev_queue);
  77 }
  78
  79 struct udev *udev_queue_get_udev(struct udev_queue *udev_queue)
  80 {
  81         if (udev_queue == NULL)
  82                 return NULL;
  83         return udev_queue->udev;
  84 }
  85
  86 unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
  87 {
  88         char filename[UTIL_PATH_SIZE];
  89         unsigned long long int seqnum;
  90         int fd;
  91         char buf[32];
  92         ssize_t len;
  93
  94         if (udev_queue == NULL)
  95                 return -EINVAL;
  96         util_strlcpy(filename, udev_get_sys_path(udev_queue->udev), sizeof(filename));
  97         util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
  98         fd = open(filename, O_RDONLY);
  99         if (fd < 0)
 100                 return 0;
 101         len = read(fd, buf, sizeof(buf));
 102         close(fd);
 103         if (len <= 2)
 104                 return 0;
 105         buf[len-1] = '\0';
 106         seqnum = strtoull(buf, NULL, 10);
 107         info(udev_queue->udev, "seqnum=%llu\n", seqnum);
 108         return seqnum;
 109 }
 110
 111 unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
 112 {
 113         char filename[UTIL_PATH_SIZE];
 114         unsigned long long int seqnum;
 115         int fd;
 116         char buf[32];
 117         ssize_t len;
 118
 119         if (udev_queue == NULL)
 120                 return -EINVAL;
 121         util_strlcpy(filename, udev_get_dev_path(udev_queue->udev), sizeof(filename));
 122         util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
 123         fd = open(filename, O_RDONLY);
 124         if (fd < 0)
 125                 return 0;
 126         len = read(fd, buf, sizeof(buf));
 127         close(fd);
 128         if (len <= 2)
 129                 return 0;
 130         buf[len-1] = '\0';
 131         seqnum = strtoull(buf, NULL, 10);
 132         info(udev_queue->udev, "seqnum=%llu\n", seqnum);
 133         udev_queue->last_seen_udev_seqnum = seqnum;
 134         return seqnum;
 135 }
 136
 137 int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
 138 {
 139         char queuename[UTIL_PATH_SIZE];
 140         struct stat statbuf;
 141         unsigned long long int seqnum_kernel;
 142
 143         if (udev_queue == NULL)
 144                 return -EINVAL;
 145         util_strlcpy(queuename, udev_get_dev_path(udev_queue->udev), sizeof(queuename));
 146         util_strlcat(queuename, "/.udev/queue", sizeof(queuename));
 147         if (stat(queuename, &statbuf) == 0) {
 148                 info(udev_queue->udev, "queue is not empty\n");
 149                 return 0;
 150         }
 151         seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
 152         if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
 153                 info(udev_queue->udev, "queue is empty\n");
 154                 return 1;
 155         }
 156         udev_queue_get_udev_seqnum(udev_queue);
 157         if (seqnum_kernel <= udev_queue->last_seen_udev_seqnum) {
 158                 info(udev_queue->udev, "queue is empty\n");
 159                 return 1;
 160         }
 161         info(udev_queue->udev, "queue is empty, but kernel events still pending [%llu]<->[%llu]\n",
 162              seqnum_kernel, udev_queue->last_seen_udev_seqnum);
 163         return 0;
 164 }
 165
 166 int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
 167 {
 168         char filename[UTIL_PATH_SIZE];
 169         struct stat statbuf;
 170
 171         if (udev_queue == NULL)
 172                 return -EINVAL;
 173         /* if we have not seen this seqnum, check if it is/was already queued */
 174         if (seqnum < udev_queue->last_seen_udev_seqnum) {
 175                 udev_queue_get_udev_seqnum(udev_queue);
 176                 if (seqnum < udev_queue->last_seen_udev_seqnum)
 177                         return 0;
 178         }
 179         snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
 180                  udev_get_dev_path(udev_queue->udev), seqnum);
 181         if (stat(filename, &statbuf) == 0)
 182                 return 0;
 183         info(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
 184         return 1;
 185 }
 186
 187 struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
 188 {
 189         char path[UTIL_PATH_SIZE];
 190         DIR *dir;
 191         struct dirent *dent;
 192
 193         if (udev_queue == NULL)
 194                 return NULL;
 195         udev_list_cleanup(udev_queue->udev, &udev_queue->queue_list);
 196         util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
 197         util_strlcat(path, "/.udev/queue", sizeof(path));
 198         dir = opendir(path);
 199         if (dir == NULL)
 200                 return NULL;
 201         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 202                 char filename[UTIL_PATH_SIZE];
 203                 char syspath[UTIL_PATH_SIZE];
 204                 size_t syslen;
 205                 ssize_t len;
 206
 207                 if (dent->d_name[0] == '.')
 208                         continue;
 209                 util_strlcpy(filename, path, sizeof(filename));
 210                 util_strlcat(filename, "/", sizeof(filename));
 211                 util_strlcat(filename, dent->d_name, sizeof(filename));
 212
 213                 syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
 214                 len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
 215                 if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
 216                         continue;
 217                 syspath[syslen + len] = '\0';
 218                 info(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
 219                 udev_list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, dent->d_name, 0, 0);
 220         }
 221         closedir(dir);
 222         return udev_list_get_entry(&udev_queue->queue_list);
 223 }
 224
 225 struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue)
 226 {
 227         char path[UTIL_PATH_SIZE];
 228         DIR *dir;
 229         struct dirent *dent;
 230
 231         if (udev_queue == NULL)
 232                 return NULL;
 233         udev_list_cleanup(udev_queue->udev, &udev_queue->failed_list);
 234         util_strlcpy(path, udev_get_dev_path(udev_queue->udev), sizeof(path));
 235         util_strlcat(path, "/.udev/failed", sizeof(path));
 236         dir = opendir(path);
 237         if (dir == NULL)
 238                 return NULL;
 239         for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
 240                 char filename[UTIL_PATH_SIZE];
 241                 char syspath[UTIL_PATH_SIZE];
 242                 struct stat statbuf;
 243                 size_t syslen;
 244                 ssize_t len;
 245
 246                 if (dent->d_name[0] == '.')
 247                         continue;
 248                 util_strlcpy(filename, path, sizeof(filename));
 249                 util_strlcat(filename, "/", sizeof(filename));
 250                 util_strlcat(filename, dent->d_name, sizeof(filename));
 251
 252                 syslen = util_strlcpy(syspath, udev_get_sys_path(udev_queue->udev), sizeof(syspath));
 253                 len = readlink(filename, &syspath[syslen], sizeof(syspath)-syslen);
 254                 if (len < 0 || len >= (ssize_t)(sizeof(syspath)-syslen))
 255                         continue;
 256                 syspath[syslen + len] = '\0';
 257                 info(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
 258                 util_strlcpy(filename, syspath, sizeof(filename));
 259                 util_strlcat(filename, "/uevent", sizeof(filename));
 260                 if (stat(filename, &statbuf) != 0)
 261                         continue;
 262                 udev_list_entry_add(udev_queue->udev, &udev_queue->failed_list, syspath, NULL, 0, 0);
 263         }
 264         closedir(dir);
 265         return udev_list_get_entry(&udev_queue->failed_list);
 266 }
 267
 268 int udev_queue_export_udev_seqnum(struct udev_queue *udev_queue, unsigned long long int seqnum)
 269 {
 270         return -1;
 271 }
 272
 273 extern int udev_queue_export_device_queued(struct udev_queue *udev_queue, struct udev_device *udev_device)
 274 {
 275         return -1;
 276 }
 277
 278 extern int udev_queue_export_device_finished(struct udev_queue *udev_queue, struct udev_device *udev_device)
 279 {
 280         return -1;
 281 }
 282
 283 extern int udev_queue_export_device_failed(struct udev_queue *udev_queue, struct udev_device *udev_device)
 284 {
 285         return -1;
 286 }