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 <malloc.h> 20 #include <string.h> 21 #include <unistd.h> 22 #include <poll.h> 23 #include <pthread.h> 24 25 #include <sys/socket.h> 26 #include <sys/un.h> 27 #include <sys/queue.h> 28 #include <linux/netlink.h> 29 30 31 LIST_HEAD(uevent_handler_head, uevent_handler) uevent_handler_list; 32 pthread_mutex_t uevent_handler_list_lock = PTHREAD_MUTEX_INITIALIZER; 33 34 struct uevent_handler { 35 void (*handler)(void *data, const char *msg, int msg_len); 36 void *handler_data; 37 LIST_ENTRY(uevent_handler) list; 38 }; 39 40 static int fd = -1; 41 42 /* Returns 0 on failure, 1 on success */ 43 int uevent_init() 44 { 45 struct sockaddr_nl addr; 46 int sz = 64*1024; 47 int s; 48 49 memset(&addr, 0, sizeof(addr)); 50 addr.nl_family = AF_NETLINK; 51 addr.nl_pid = getpid(); 52 addr.nl_groups = 0xffffffff; 53 54 s = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); 55 if(s < 0) 56 return 0; 57 58 setsockopt(s, SOL_SOCKET, SO_RCVBUFFORCE, &sz, sizeof(sz)); 59 60 if(bind(s, (struct sockaddr *) &addr, sizeof(addr)) < 0) { 61 close(s); 62 return 0; 63 } 64 65 fd = s; 66 return (fd > 0); 67 } 68 69 int uevent_get_fd() 70 { 71 return fd; 72 } 73 74 int uevent_next_event(char* buffer, int buffer_length) 75 { 76 while (1) { 77 struct pollfd fds; 78 int nr; 79 80 fds.fd = fd; 81 fds.events = POLLIN; 82 fds.revents = 0; 83 nr = poll(&fds, 1, -1); 84 85 if(nr > 0 && (fds.revents & POLLIN)) { 86 int count = recv(fd, buffer, buffer_length, 0); 87 if (count > 0) { 88 struct uevent_handler *h; 89 pthread_mutex_lock(&uevent_handler_list_lock); 90 LIST_FOREACH(h, &uevent_handler_list, list) 91 h->handler(h->handler_data, buffer, buffer_length); 92 pthread_mutex_unlock(&uevent_handler_list_lock); 93 94 return count; 95 } 96 } 97 } 98 99 // won't get here 100 return 0; 101 } 102 103 int uevent_add_native_handler(void (*handler)(void *data, const char *msg, int msg_len), 104 void *handler_data) 105 { 106 struct uevent_handler *h; 107 108 h = malloc(sizeof(struct uevent_handler)); 109 if (h == NULL) 110 return -1; 111 h->handler = handler; 112 h->handler_data = handler_data; 113 114 pthread_mutex_lock(&uevent_handler_list_lock); 115 LIST_INSERT_HEAD(&uevent_handler_list, h, list); 116 pthread_mutex_unlock(&uevent_handler_list_lock); 117 118 return 0; 119 } 120 121 int uevent_remove_native_handler(void (*handler)(void *data, const char *msg, int msg_len)) 122 { 123 struct uevent_handler *h; 124 int err = -1; 125 126 pthread_mutex_lock(&uevent_handler_list_lock); 127 LIST_FOREACH(h, &uevent_handler_list, list) { 128 if (h->handler == handler) { 129 LIST_REMOVE(h, list); 130 err = 0; 131 break; 132 } 133 } 134 pthread_mutex_unlock(&uevent_handler_list_lock); 135 136 return err; 137 } 138
