platform_hardware_libhardwa.../uevent.c
Steven Moreland 682a1afcf4 Revert "uevent.c: avoid POLLERR infinite loop"
This reverts commit e44aa092c5.

Reason for revert: b/318929257

Change-Id: I5d114adcd3df31ea3745354d8021e50852cdc2ef
2024-01-08 19:17:06 +00:00

137 lines
3.4 KiB
C

/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <hardware_legacy/uevent.h>
#include <malloc.h>
#include <string.h>
#include <unistd.h>
#include <poll.h>
#include <pthread.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/queue.h>
#include <linux/netlink.h>
LIST_HEAD(uevent_handler_head, uevent_handler) uevent_handler_list;
pthread_mutex_t uevent_handler_list_lock = PTHREAD_MUTEX_INITIALIZER;
struct uevent_handler {
void (*handler)(void *data, const char *msg, int msg_len);
void *handler_data;
LIST_ENTRY(uevent_handler) list;
};
static int fd = -1;
/* Returns 0 on failure, 1 on success */
int uevent_init()
{
struct sockaddr_nl addr;
int sz = 64*1024;
int s;
memset(&addr, 0, sizeof(addr));
addr.nl_family = AF_NETLINK;
addr.nl_pid = getpid();
addr.nl_groups = 0xffffffff;
s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
if(s < 0)
return 0;
setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz));
if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
close(s);
return 0;
}
fd = s;
return (fd > 0);
}
int uevent_get_fd()
{
return fd;
}
int uevent_next_event(char* buffer, int buffer_length)
{
while (1) {
struct pollfd fds;
int nr;
fds.fd = fd;
fds.events = POLLIN;
fds.revents = 0;
nr = poll(&fds, 1, -1);
if(nr > 0 && (fds.revents & POLLIN)) {
int count = recv(fd, buffer, buffer_length, 0);
if (count > 0) {
struct uevent_handler *h;
pthread_mutex_lock(&uevent_handler_list_lock);
LIST_FOREACH(h, &uevent_handler_list, list)
h->handler(h->handler_data, buffer, buffer_length);
pthread_mutex_unlock(&uevent_handler_list_lock);
return count;
}
}
}
// won't get here
return 0;
}
int uevent_add_native_handler(void (*handler)(void *data, const char *msg, int msg_len),
void *handler_data)
{
struct uevent_handler *h;
h = malloc(sizeof(struct uevent_handler));
if (h == NULL)
return -1;
h->handler = handler;
h->handler_data = handler_data;
pthread_mutex_lock(&uevent_handler_list_lock);
LIST_INSERT_HEAD(&uevent_handler_list, h, list);
pthread_mutex_unlock(&uevent_handler_list_lock);
return 0;
}
int uevent_remove_native_handler(void (*handler)(void *data, const char *msg, int msg_len))
{
struct uevent_handler *h;
int err = -1;
pthread_mutex_lock(&uevent_handler_list_lock);
LIST_FOREACH(h, &uevent_handler_list, list) {
if (h->handler == handler) {
LIST_REMOVE(h, list);
err = 0;
break;
}
}
pthread_mutex_unlock(&uevent_handler_list_lock);
return err;
}