mirror of
https://github.com/systemd/systemd.git
synced 2024-12-25 01:34:28 +03:00
503 lines
12 KiB
C
503 lines
12 KiB
C
/*
|
|
* libudev - interface to udev device information
|
|
*
|
|
* Copyright (C) 2008 Kay Sievers <kay.sievers@vrfy.org>
|
|
* Copyright (C) 2009 Alan Jenkins <alan-jenkins@tuffmail.co.uk>
|
|
*
|
|
* This library is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 of the License, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <stddef.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
#include <string.h>
|
|
#include <dirent.h>
|
|
#include <fcntl.h>
|
|
#include <limits.h>
|
|
#include <sys/stat.h>
|
|
|
|
#include "libudev.h"
|
|
#include "libudev-private.h"
|
|
|
|
/**
|
|
* SECTION:libudev-queue
|
|
* @short_description: access to currently active events
|
|
*
|
|
* The udev daemon processes event asynchronously. All events which do not have
|
|
* interdependencies are run in parallel. This exports the current state of the
|
|
* event processing queue, and the currently event sequence numbers from the kernel
|
|
* and the udev daemon.
|
|
*/
|
|
|
|
/**
|
|
* udev_queue:
|
|
*
|
|
* Opaque object representing the current event queue in the udev daemon.
|
|
*/
|
|
struct udev_queue {
|
|
struct udev *udev;
|
|
int refcount;
|
|
struct udev_list_node queue_list;
|
|
struct udev_list_node failed_list;
|
|
};
|
|
|
|
/**
|
|
* udev_queue_new:
|
|
* @udev: udev library context
|
|
*
|
|
* The initial refcount is 1, and needs to be decremented to
|
|
* release the resources of the udev queue context.
|
|
*
|
|
* Returns: the udev queue context, or #NULL on error.
|
|
**/
|
|
struct udev_queue *udev_queue_new(struct udev *udev)
|
|
{
|
|
struct udev_queue *udev_queue;
|
|
|
|
if (udev == NULL)
|
|
return NULL;
|
|
|
|
udev_queue = calloc(1, sizeof(struct udev_queue));
|
|
if (udev_queue == NULL)
|
|
return NULL;
|
|
udev_queue->refcount = 1;
|
|
udev_queue->udev = udev;
|
|
udev_list_init(&udev_queue->queue_list);
|
|
udev_list_init(&udev_queue->failed_list);
|
|
return udev_queue;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_ref:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Take a reference of a udev queue context.
|
|
*
|
|
* Returns: the same udev queue context.
|
|
**/
|
|
struct udev_queue *udev_queue_ref(struct udev_queue *udev_queue)
|
|
{
|
|
if (udev_queue == NULL)
|
|
return NULL;
|
|
udev_queue->refcount++;
|
|
return udev_queue;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_unref:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Drop a reference of a udev queue context. If the refcount reaches zero,
|
|
* the resources of the queue context will be released.
|
|
**/
|
|
void udev_queue_unref(struct udev_queue *udev_queue)
|
|
{
|
|
if (udev_queue == NULL)
|
|
return;
|
|
udev_queue->refcount--;
|
|
if (udev_queue->refcount > 0)
|
|
return;
|
|
udev_list_cleanup_entries(udev_queue->udev, &udev_queue->queue_list);
|
|
udev_list_cleanup_entries(udev_queue->udev, &udev_queue->failed_list);
|
|
free(udev_queue);
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_udev:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Retrieve the udev library context the queue context was created with.
|
|
*
|
|
* Returns: the udev library context.
|
|
**/
|
|
struct udev *udev_queue_get_udev(struct udev_queue *udev_queue)
|
|
{
|
|
if (udev_queue == NULL)
|
|
return NULL;
|
|
return udev_queue->udev;
|
|
}
|
|
|
|
unsigned long long int udev_get_kernel_seqnum(struct udev *udev)
|
|
{
|
|
char filename[UTIL_PATH_SIZE];
|
|
unsigned long long int seqnum;
|
|
int fd;
|
|
char buf[32];
|
|
ssize_t len;
|
|
|
|
util_strscpyl(filename, sizeof(filename), udev_get_sys_path(udev), "/kernel/uevent_seqnum", NULL);
|
|
fd = open(filename, O_RDONLY);
|
|
if (fd < 0)
|
|
return 0;
|
|
len = read(fd, buf, sizeof(buf));
|
|
close(fd);
|
|
if (len <= 2)
|
|
return 0;
|
|
buf[len-1] = '\0';
|
|
seqnum = strtoull(buf, NULL, 10);
|
|
return seqnum;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_kernel_seqnum:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: the current kernel event sequence number.
|
|
**/
|
|
unsigned long long int udev_queue_get_kernel_seqnum(struct udev_queue *udev_queue)
|
|
{
|
|
unsigned long long int seqnum;
|
|
|
|
if (udev_queue == NULL)
|
|
return -EINVAL;
|
|
|
|
seqnum = udev_get_kernel_seqnum(udev_queue->udev);
|
|
dbg(udev_queue->udev, "seqnum=%llu\n", seqnum);
|
|
return seqnum;
|
|
}
|
|
|
|
int udev_queue_read_seqnum(FILE *queue_file, unsigned long long int *seqnum)
|
|
{
|
|
if (fread(seqnum, sizeof(unsigned long long int), 1, queue_file) != 1)
|
|
return -1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
ssize_t udev_queue_skip_devpath(FILE *queue_file)
|
|
{
|
|
unsigned short int len;
|
|
|
|
if (fread(&len, sizeof(unsigned short int), 1, queue_file) == 1) {
|
|
char devpath[len];
|
|
|
|
/* use fread to skip, fseek might drop buffered data */
|
|
if (fread(devpath, 1, len, queue_file) == len)
|
|
return len;
|
|
}
|
|
|
|
return -1;
|
|
}
|
|
|
|
ssize_t udev_queue_read_devpath(FILE *queue_file, char *devpath, size_t size)
|
|
{
|
|
unsigned short int read_bytes = 0;
|
|
unsigned short int len;
|
|
|
|
if (fread(&len, sizeof(unsigned short int), 1, queue_file) != 1)
|
|
return -1;
|
|
|
|
read_bytes = (len < size - 1) ? len : size - 1;
|
|
if (fread(devpath, 1, read_bytes, queue_file) != read_bytes)
|
|
return -1;
|
|
devpath[read_bytes] = '\0';
|
|
|
|
/* if devpath was too long, skip unread characters */
|
|
if (read_bytes != len) {
|
|
unsigned short int skip_bytes = len - read_bytes;
|
|
char buf[skip_bytes];
|
|
|
|
if (fread(buf, 1, skip_bytes, queue_file) != skip_bytes)
|
|
return -1;
|
|
}
|
|
|
|
return read_bytes;
|
|
}
|
|
|
|
static FILE *open_queue_file(struct udev_queue *udev_queue, unsigned long long int *seqnum_start)
|
|
{
|
|
char filename[UTIL_PATH_SIZE];
|
|
FILE *queue_file;
|
|
|
|
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev_queue->udev), "/.udev/queue.bin", NULL);
|
|
queue_file = fopen(filename, "r");
|
|
if (queue_file == NULL)
|
|
return NULL;
|
|
|
|
if (udev_queue_read_seqnum(queue_file, seqnum_start) < 0) {
|
|
err(udev_queue->udev, "corrupt queue file\n");
|
|
fclose(queue_file);
|
|
return NULL;
|
|
}
|
|
|
|
return queue_file;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_udev_seqnum:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: the last known udev event sequence number.
|
|
**/
|
|
unsigned long long int udev_queue_get_udev_seqnum(struct udev_queue *udev_queue)
|
|
{
|
|
unsigned long long int seqnum_udev;
|
|
FILE *queue_file;
|
|
|
|
queue_file = open_queue_file(udev_queue, &seqnum_udev);
|
|
if (queue_file == NULL)
|
|
return 0;
|
|
|
|
while (1) {
|
|
unsigned long long int seqnum;
|
|
ssize_t devpath_len;
|
|
|
|
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
|
|
break;
|
|
devpath_len = udev_queue_skip_devpath(queue_file);
|
|
if (devpath_len < 0)
|
|
break;
|
|
if (devpath_len > 0)
|
|
seqnum_udev = seqnum;
|
|
}
|
|
|
|
fclose(queue_file);
|
|
return seqnum_udev;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_udev_is_active:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: a flag indicating if udev is active.
|
|
**/
|
|
int udev_queue_get_udev_is_active(struct udev_queue *udev_queue)
|
|
{
|
|
unsigned long long int seqnum_start;
|
|
FILE *queue_file;
|
|
|
|
queue_file = open_queue_file(udev_queue, &seqnum_start);
|
|
if (queue_file == NULL)
|
|
return 0;
|
|
|
|
fclose(queue_file);
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_queue_is_empty:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: a flag indicating if udev is currently handling events.
|
|
**/
|
|
int udev_queue_get_queue_is_empty(struct udev_queue *udev_queue)
|
|
{
|
|
unsigned long long int seqnum_kernel;
|
|
unsigned long long int seqnum_udev = 0;
|
|
int queued = 0;
|
|
int is_empty = 0;
|
|
FILE *queue_file;
|
|
|
|
if (udev_queue == NULL)
|
|
return -EINVAL;
|
|
queue_file = open_queue_file(udev_queue, &seqnum_udev);
|
|
if (queue_file == NULL)
|
|
return 1;
|
|
|
|
while (1) {
|
|
unsigned long long int seqnum;
|
|
ssize_t devpath_len;
|
|
|
|
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
|
|
break;
|
|
devpath_len = udev_queue_skip_devpath(queue_file);
|
|
if (devpath_len < 0)
|
|
break;
|
|
|
|
if (devpath_len > 0) {
|
|
queued++;
|
|
seqnum_udev = seqnum;
|
|
} else {
|
|
queued--;
|
|
}
|
|
}
|
|
|
|
if (queued > 0) {
|
|
dbg(udev_queue->udev, "queue is not empty\n");
|
|
goto out;
|
|
}
|
|
|
|
seqnum_kernel = udev_queue_get_kernel_seqnum(udev_queue);
|
|
if (seqnum_udev < seqnum_kernel) {
|
|
dbg(udev_queue->udev, "queue is empty but kernel events still pending [%llu]<->[%llu]\n",
|
|
seqnum_kernel, seqnum_udev);
|
|
goto out;
|
|
}
|
|
|
|
dbg(udev_queue->udev, "queue is empty\n");
|
|
is_empty = 1;
|
|
|
|
out:
|
|
fclose(queue_file);
|
|
return is_empty;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_seqnum_sequence_is_finished:
|
|
* @udev_queue: udev queue context
|
|
* @start: first event sequence number
|
|
* @end: last event sequence number
|
|
*
|
|
* Returns: if any of the sequence numbers in the given range is currently active.
|
|
**/
|
|
int udev_queue_get_seqnum_sequence_is_finished(struct udev_queue *udev_queue,
|
|
unsigned long long int start, unsigned long long int end)
|
|
{
|
|
unsigned long long int seqnum = 0;
|
|
ssize_t devpath_len;
|
|
int unfinished;
|
|
FILE *queue_file;
|
|
|
|
if (udev_queue == NULL)
|
|
return -EINVAL;
|
|
queue_file = open_queue_file(udev_queue, &seqnum);
|
|
if (queue_file == NULL)
|
|
return 1;
|
|
if (start < seqnum)
|
|
start = seqnum;
|
|
if (start > end) {
|
|
fclose(queue_file);
|
|
return 1;
|
|
}
|
|
if (end - start > INT_MAX - 1) {
|
|
fclose(queue_file);
|
|
return -EOVERFLOW;
|
|
}
|
|
unfinished = (end - start) + 1;
|
|
|
|
while (unfinished > 0) {
|
|
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
|
|
break;
|
|
devpath_len = udev_queue_skip_devpath(queue_file);
|
|
if (devpath_len < 0)
|
|
break;
|
|
|
|
if (devpath_len == 0) {
|
|
if (seqnum >= start && seqnum <= end)
|
|
unfinished--;
|
|
}
|
|
}
|
|
fclose(queue_file);
|
|
|
|
return (unfinished == 0);
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_seqnum_is_finished:
|
|
* @udev_queue: udev queue context
|
|
* @seqnum: sequence number
|
|
*
|
|
* Returns: a flag indicating if the given sequence number is handled.
|
|
**/
|
|
int udev_queue_get_seqnum_is_finished(struct udev_queue *udev_queue, unsigned long long int seqnum)
|
|
{
|
|
if (!udev_queue_get_seqnum_sequence_is_finished(udev_queue, seqnum, seqnum))
|
|
return 0;
|
|
|
|
dbg(udev_queue->udev, "seqnum: %llu finished\n", seqnum);
|
|
return 1;
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_queued_list_entry:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: the first entry of the list of queued events.
|
|
**/
|
|
struct udev_list_entry *udev_queue_get_queued_list_entry(struct udev_queue *udev_queue)
|
|
{
|
|
unsigned long long int seqnum;
|
|
FILE *queue_file;
|
|
|
|
if (udev_queue == NULL)
|
|
return NULL;
|
|
udev_list_cleanup_entries(udev_queue->udev, &udev_queue->queue_list);
|
|
|
|
queue_file = open_queue_file(udev_queue, &seqnum);
|
|
if (queue_file == NULL)
|
|
return NULL;
|
|
|
|
while (1) {
|
|
char syspath[UTIL_PATH_SIZE];
|
|
char *s;
|
|
size_t l;
|
|
ssize_t len;
|
|
char seqnum_str[32];
|
|
struct udev_list_entry *list_entry;
|
|
|
|
if (udev_queue_read_seqnum(queue_file, &seqnum) < 0)
|
|
break;
|
|
snprintf(seqnum_str, sizeof(seqnum_str), "%llu", seqnum);
|
|
|
|
s = syspath;
|
|
l = util_strpcpyl(&s, sizeof(syspath), udev_get_sys_path(udev_queue->udev), NULL);
|
|
len = udev_queue_read_devpath(queue_file, s, l);
|
|
if (len < 0)
|
|
break;
|
|
|
|
if (len > 0) {
|
|
udev_list_entry_add(udev_queue->udev, &udev_queue->queue_list, syspath, seqnum_str, 0, 0);
|
|
} else {
|
|
udev_list_entry_foreach(list_entry, udev_list_get_entry(&udev_queue->queue_list)) {
|
|
if (strcmp(seqnum_str, udev_list_entry_get_value(list_entry)) == 0) {
|
|
udev_list_entry_delete(list_entry);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
fclose(queue_file);
|
|
|
|
return udev_list_get_entry(&udev_queue->queue_list);
|
|
}
|
|
|
|
/**
|
|
* udev_queue_get_failed_list_entry:
|
|
* @udev_queue: udev queue context
|
|
*
|
|
* Returns: the first entry of the list of recorded failed events.
|
|
**/
|
|
struct udev_list_entry *udev_queue_get_failed_list_entry(struct udev_queue *udev_queue)
|
|
{
|
|
char path[UTIL_PATH_SIZE];
|
|
DIR *dir;
|
|
struct dirent *dent;
|
|
|
|
if (udev_queue == NULL)
|
|
return NULL;
|
|
udev_list_cleanup_entries(udev_queue->udev, &udev_queue->failed_list);
|
|
util_strscpyl(path, sizeof(path), udev_get_dev_path(udev_queue->udev), "/.udev/failed", NULL);
|
|
dir = opendir(path);
|
|
if (dir == NULL)
|
|
return NULL;
|
|
for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) {
|
|
char filename[UTIL_PATH_SIZE];
|
|
char syspath[UTIL_PATH_SIZE];
|
|
char *s;
|
|
size_t l;
|
|
ssize_t len;
|
|
struct stat statbuf;
|
|
|
|
if (dent->d_name[0] == '.')
|
|
continue;
|
|
s = syspath;
|
|
l = util_strpcpyl(&s, sizeof(syspath), udev_get_sys_path(udev_queue->udev), NULL);
|
|
len = readlinkat(dirfd(dir), dent->d_name, s, l);
|
|
if (len < 0 || (size_t)len >= l)
|
|
continue;
|
|
s[len] = '\0';
|
|
dbg(udev_queue->udev, "found '%s' [%s]\n", syspath, dent->d_name);
|
|
util_strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
|
|
if (stat(filename, &statbuf) != 0)
|
|
continue;
|
|
udev_list_entry_add(udev_queue->udev, &udev_queue->failed_list, syspath, NULL, 0, 0);
|
|
}
|
|
closedir(dir);
|
|
return udev_list_get_entry(&udev_queue->failed_list);
|
|
}
|