1/* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17#include <hardware_legacy/uevent.h> 18 19#include <string.h> 20#include <unistd.h> 21#include <poll.h> 22#include <pthread.h> 23 24#include <sys/socket.h> 25#include <sys/un.h> 26#include <sys/queue.h> 27#include <linux/netlink.h> 28 29 30LIST_HEAD(uevent_handler_head, uevent_handler) uevent_handler_list; 31pthread_mutex_t uevent_handler_list_lock = PTHREAD_MUTEX_INITIALIZER; 32 33struct uevent_handler { 34 void (*handler)(void *data, const char *msg, int msg_len); 35 void *handler_data; 36 LIST_ENTRY(uevent_handler) list; 37}; 38 39static int fd = -1; 40 41/* Returns 0 on failure, 1 on success */ 42int uevent_init() 43{ 44 struct sockaddr_nl addr; 45 int sz = 64*1024; 46 int s; 47 48 memset(&addr, 0, sizeof(addr)); 49 addr.nl_family = AF_NETLINK; 50 addr.nl_pid = getpid(); 51 addr.nl_groups = 0xffffffff; 52 53 s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); 54 if(s < 0) 55 return 0; 56 57 setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)); 58 59 if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 60 close(s); 61 return 0; 62 } 63 64 fd = s; 65 return (fd > 0); 66} 67 68int uevent_get_fd() 69{ 70 return fd; 71} 72 73int uevent_next_event(char* buffer, int buffer_length) 74{ 75 while (1) { 76 struct pollfd fds; 77 int nr; 78 79 fds.fd = fd; 80 fds.events = POLLIN; 81 fds.revents = 0; 82 nr = poll(&fds, 1, -1); 83 84 if(nr > 0 && (fds.revents & POLLIN)) { 85 int count = recv(fd, buffer, buffer_length, 0); 86 if (count > 0) { 87 struct uevent_handler *h; 88 pthread_mutex_lock(&uevent_handler_list_lock); 89 LIST_FOREACH(h, &uevent_handler_list, list) 90 h->handler(h->handler_data, buffer, buffer_length); 91 pthread_mutex_unlock(&uevent_handler_list_lock); 92 93 return count; 94 } 95 } 96 } 97 98 // won't get here 99 return 0; 100} 101 102int uevent_add_native_handler(void (*handler)(void *data, const char *msg, int msg_len), 103 void *handler_data) 104{ 105 struct uevent_handler *h; 106 107 h = malloc(sizeof(struct uevent_handler)); 108 if (h == NULL) 109 return -1; 110 h->handler = handler; 111 h->handler_data = handler_data; 112 113 pthread_mutex_lock(&uevent_handler_list_lock); 114 LIST_INSERT_HEAD(&uevent_handler_list, h, list); 115 pthread_mutex_unlock(&uevent_handler_list_lock); 116 117 return 0; 118} 119 120int uevent_remove_native_handler(void (*handler)(void *data, const char *msg, int msg_len)) 121{ 122 struct uevent_handler *h; 123 int err = -1; 124 125 pthread_mutex_lock(&uevent_handler_list_lock); 126 LIST_FOREACH(h, &uevent_handler_list, list) { 127 if (h->handler == handler) { 128 LIST_REMOVE(h, list); 129 err = 0; 130 break; 131 } 132 } 133 pthread_mutex_unlock(&uevent_handler_list_lock); 134 135 return err; 136} 137