352 lines
8.4 KiB
C
352 lines
8.4 KiB
C
/*
|
|
* Copyright (c) 2020-2021 illiliti <illiliti@protonmail.com>
|
|
* SPDX-License-Identifier: ISC
|
|
*
|
|
* Permission to use, copy, modify, and/or distribute this software for any
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
* copyright notice and this permission notice appear in all copies.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
*/
|
|
|
|
#include <poll.h>
|
|
#include <errno.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <limits.h>
|
|
#include <pthread.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/eventfd.h>
|
|
#include <sys/inotify.h>
|
|
|
|
#include "udev.h"
|
|
#include "udev_list.h"
|
|
|
|
#ifndef UDEV_MONITOR_DIR
|
|
#define UDEV_MONITOR_DIR "/tmp/.libudev-zero"
|
|
#endif
|
|
|
|
struct udev_monitor {
|
|
struct udev_list_entry subsystem_match;
|
|
struct udev_list_entry devtype_match;
|
|
struct udev *udev;
|
|
pthread_t thread;
|
|
const char *dir;
|
|
int signal_fd;
|
|
int refcount;
|
|
int sfd[2];
|
|
int ifd;
|
|
};
|
|
|
|
static int filter_devtype(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
|
|
{
|
|
struct udev_list_entry *list_entry;
|
|
const char *devtype;
|
|
|
|
devtype = udev_device_get_devtype(udev_device);
|
|
list_entry = udev_list_entry_get_next(&udev_monitor->devtype_match);
|
|
|
|
if (!list_entry) {
|
|
return 1;
|
|
}
|
|
|
|
if (!devtype) {
|
|
return 0;
|
|
}
|
|
|
|
while (list_entry) {
|
|
if (strcmp(devtype, udev_list_entry_get_name(list_entry)) == 0) {
|
|
return 1;
|
|
}
|
|
|
|
list_entry = udev_list_entry_get_next(list_entry);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int filter_subsystem(struct udev_monitor *udev_monitor, struct udev_device *udev_device)
|
|
{
|
|
struct udev_list_entry *list_entry;
|
|
const char *subsystem;
|
|
|
|
subsystem = udev_device_get_subsystem(udev_device);
|
|
list_entry = udev_list_entry_get_next(&udev_monitor->subsystem_match);
|
|
|
|
if (!list_entry) {
|
|
return 1;
|
|
}
|
|
|
|
if (!subsystem) {
|
|
return 0;
|
|
}
|
|
|
|
while (list_entry) {
|
|
if (strcmp(subsystem, udev_list_entry_get_name(list_entry)) == 0) {
|
|
return 1;
|
|
}
|
|
|
|
list_entry = udev_list_entry_get_next(list_entry);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
struct udev_device *udev_monitor_receive_device(struct udev_monitor *udev_monitor)
|
|
{
|
|
char file[PATH_MAX], data[4096];
|
|
struct udev_device *udev_device;
|
|
|
|
if (recv(udev_monitor->sfd[0], data, sizeof(data), 0) == -1) {
|
|
return NULL;
|
|
}
|
|
|
|
// check truncation error to make gcc happy
|
|
if ((unsigned)snprintf(file, sizeof(file), "%s/%s", udev_monitor->dir, data) >= sizeof(file)) {
|
|
return NULL;
|
|
}
|
|
|
|
udev_device = udev_device_new_from_file(udev_monitor->udev, file);
|
|
|
|
if (!udev_device) {
|
|
return NULL;
|
|
}
|
|
|
|
if (!filter_subsystem(udev_monitor, udev_device) ||
|
|
!filter_devtype(udev_monitor, udev_device)) {
|
|
udev_device_unref(udev_device);
|
|
return NULL;
|
|
}
|
|
|
|
return udev_device;
|
|
}
|
|
|
|
static void *handle_event(void *ptr)
|
|
{
|
|
struct udev_monitor *udev_monitor = ptr;
|
|
struct inotify_event *event;
|
|
struct pollfd poll_fds[2];
|
|
char data[4096];
|
|
ssize_t len;
|
|
int i;
|
|
|
|
poll_fds[0].fd = udev_monitor->ifd;
|
|
poll_fds[0].events = POLLIN;
|
|
|
|
poll_fds[1].fd = udev_monitor->signal_fd;
|
|
poll_fds[1].events = POLLIN;
|
|
|
|
while (1) {
|
|
if (poll(poll_fds, 2, -1) == -1) {
|
|
if (errno == EINTR) {
|
|
continue;
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
// exit on explicit signal
|
|
if (poll_fds[1].revents & POLLIN) {
|
|
return NULL;
|
|
}
|
|
|
|
// exit on poll error
|
|
if (!(poll_fds[0].revents & POLLIN)) {
|
|
return NULL;
|
|
}
|
|
|
|
len = read(udev_monitor->ifd, data, sizeof(data));
|
|
|
|
if (len == -1) {
|
|
return NULL;
|
|
}
|
|
|
|
for (i = 0; i < len; i += sizeof(struct inotify_event) + event->len) {
|
|
event = (struct inotify_event *)&data[i];
|
|
|
|
// TODO directory is removed
|
|
if (event->mask & IN_IGNORED) {
|
|
break;
|
|
}
|
|
|
|
if (event->mask & IN_ISDIR) {
|
|
continue;
|
|
}
|
|
|
|
send(udev_monitor->sfd[1], event->name, event->len, 0);
|
|
}
|
|
}
|
|
|
|
// unreachable
|
|
return NULL;
|
|
}
|
|
|
|
int udev_monitor_enable_receiving(struct udev_monitor *udev_monitor)
|
|
{
|
|
return udev_monitor ? (pthread_create(&udev_monitor->thread, NULL, handle_event, udev_monitor) == 0) - 1 : -1;
|
|
}
|
|
|
|
/* XXX NOT IMPLEMENTED */ int udev_monitor_set_receive_buffer_size(struct udev_monitor *udev_monitor, int size)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int udev_monitor_get_fd(struct udev_monitor *udev_monitor)
|
|
{
|
|
return udev_monitor ? udev_monitor->sfd[0] : -1;
|
|
}
|
|
|
|
struct udev *udev_monitor_get_udev(struct udev_monitor *udev_monitor)
|
|
{
|
|
return udev_monitor ? udev_monitor->udev : NULL;
|
|
}
|
|
|
|
/* XXX NOT IMPLEMENTED */ int udev_monitor_filter_update(struct udev_monitor *udev_monitor)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* XXX NOT IMPLEMENTED */ int udev_monitor_filter_remove(struct udev_monitor *udev_monitor)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int udev_monitor_filter_add_match_subsystem_devtype(struct udev_monitor *udev_monitor, const char *subsystem, const char *devtype)
|
|
{
|
|
if (!udev_monitor || !subsystem) {
|
|
return -1;
|
|
}
|
|
|
|
udev_list_entry_add(&udev_monitor->subsystem_match, subsystem, NULL, 0);
|
|
|
|
if (devtype) {
|
|
udev_list_entry_add(&udev_monitor->devtype_match, devtype, NULL, 0);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* XXX NOT IMPLEMENTED */ int udev_monitor_filter_add_match_tag(struct udev_monitor *udev_monitor, const char *tag)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
struct udev_monitor *udev_monitor_new_from_netlink(struct udev *udev, const char *name)
|
|
{
|
|
struct udev_monitor *udev_monitor;
|
|
|
|
if (!udev || !name) {
|
|
return NULL;
|
|
}
|
|
|
|
udev_monitor = calloc(1, sizeof(*udev_monitor));
|
|
|
|
if (!udev_monitor) {
|
|
return NULL;
|
|
}
|
|
|
|
udev_monitor->signal_fd = eventfd(0, EFD_CLOEXEC | EFD_NONBLOCK);
|
|
|
|
if (udev_monitor->signal_fd == -1) {
|
|
goto free_monitor;
|
|
}
|
|
|
|
udev_monitor->ifd = inotify_init1(IN_CLOEXEC | IN_NONBLOCK);
|
|
|
|
if (udev_monitor->ifd == -1) {
|
|
goto close_signal_fd;
|
|
}
|
|
|
|
// TODO docs
|
|
udev_monitor->dir = getenv("UDEV_MONITOR_DIR");
|
|
|
|
if (!udev_monitor->dir || udev_monitor->dir[0] == '\0') {
|
|
udev_monitor->dir = UDEV_MONITOR_DIR;
|
|
|
|
if (access(udev_monitor->dir, F_OK) == -1) {
|
|
if (errno != ENOENT) {
|
|
goto close_ifd;
|
|
}
|
|
|
|
if (mkdir(udev_monitor->dir, 0) == -1) {
|
|
goto close_ifd;
|
|
}
|
|
|
|
if (chmod(udev_monitor->dir, 0777) == -1) {
|
|
goto close_ifd;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (inotify_add_watch(udev_monitor->ifd, udev_monitor->dir, IN_CLOSE_WRITE | IN_EXCL_UNLINK | IN_ONLYDIR) == -1) {
|
|
goto close_ifd;
|
|
}
|
|
|
|
if (socketpair(AF_UNIX, SOCK_DGRAM | SOCK_CLOEXEC | SOCK_NONBLOCK, 0, udev_monitor->sfd) == -1) {
|
|
goto close_ifd;
|
|
}
|
|
|
|
udev_monitor->refcount = 1;
|
|
udev_monitor->udev = udev;
|
|
return udev_monitor;
|
|
|
|
close_ifd:
|
|
close(udev_monitor->ifd);
|
|
|
|
close_signal_fd:
|
|
close(udev_monitor->signal_fd);
|
|
|
|
free_monitor:
|
|
free(udev_monitor);
|
|
return NULL;
|
|
}
|
|
|
|
struct udev_monitor *udev_monitor_ref(struct udev_monitor *udev_monitor)
|
|
{
|
|
if (!udev_monitor) {
|
|
return NULL;
|
|
}
|
|
|
|
udev_monitor->refcount++;
|
|
return udev_monitor;
|
|
}
|
|
|
|
struct udev_monitor *udev_monitor_unref(struct udev_monitor *udev_monitor)
|
|
{
|
|
int i;
|
|
|
|
if (!udev_monitor) {
|
|
return NULL;
|
|
}
|
|
|
|
if (--udev_monitor->refcount > 0) {
|
|
return NULL;
|
|
}
|
|
|
|
// Wake up the event thread
|
|
eventfd_write(udev_monitor->signal_fd, 1);
|
|
// waiting for event thread to end before freeing udev_monitor
|
|
pthread_join(udev_monitor->thread, NULL);
|
|
|
|
udev_list_entry_free_all(&udev_monitor->devtype_match);
|
|
udev_list_entry_free_all(&udev_monitor->subsystem_match);
|
|
|
|
for (i = 0; i < 2; i++) {
|
|
close(udev_monitor->sfd[i]);
|
|
}
|
|
|
|
close(udev_monitor->signal_fd);
|
|
close(udev_monitor->ifd);
|
|
free(udev_monitor);
|
|
return NULL;
|
|
}
|