1 /* 2 * Copyright (C) 2012 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 <stdlib.h> 18 #include <errno.h> 19 #include <fcntl.h> 20 #include <string.h> 21 #include <dirent.h> 22 23 #include <dlfcn.h> 24 25 #include <sys/socket.h> 26 #include <sys/stat.h> 27 #include <sys/ioctl.h> 28 #include <sys/types.h> 29 30 #include <netinet/in.h> 31 #include <arpa/inet.h> 32 33 #define LOG_TAG "InterfaceController" 34 #include <cutils/log.h> 35 #include <netutils/ifc.h> 36 #include <private/android_filesystem_config.h> 37 38 #include "NetdConstants.h" 39 40 #include "InterfaceController.h" 41 42 char if_cmd_lib_file_name[] = "/system/lib/libnetcmdiface.so"; 43 char set_cmd_func_name[] = "net_iface_send_command"; 44 char set_cmd_init_func_name[] = "net_iface_send_command_init"; 45 char set_cmd_fini_func_name[] = "net_iface_send_command_fini"; 46 47 const char ipv6_proc_path[] = "/proc/sys/net/ipv6/conf"; 48 49 InterfaceController::InterfaceController() 50 : sendCommand_(NULL) { 51 // Initial IPv6 settings. 52 // By default, accept_ra is set to 1 (accept RAs unless forwarding is on) on all interfaces. 53 // This causes RAs to work or not work based on whether forwarding is on, and causes routes 54 // learned from RAs to go away when forwarding is turned on. Make this behaviour predictable 55 // by always setting accept_ra to 2. 56 setAcceptRA("2"); 57 58 libh_ = dlopen(if_cmd_lib_file_name, RTLD_NOW | RTLD_LOCAL); 59 if (libh_ == NULL) { 60 const char *err_str = dlerror(); 61 ALOGW("Warning (%s) while opening the net interface command library", err_str ? err_str : "unknown"); 62 } else { 63 sendCommandInit_ = (int (*)(void))dlsym(libh_, set_cmd_init_func_name); 64 if (sendCommandInit_ == NULL) { 65 const char *err_str = dlerror(); 66 ALOGW("Error (%s) while searching for the interface command init function", err_str ? err_str : "unknown"); 67 } else if (sendCommandInit_()) { 68 ALOGE("Can't init the interface command API"); 69 return; 70 } 71 sendCommandFini_ = (int (*)(void))dlsym(libh_, set_cmd_fini_func_name); 72 if (sendCommandFini_ == NULL) { 73 const char *err_str = dlerror(); 74 ALOGW("Error (%s) while searching for the interface command fini function", err_str ? err_str : "unknown"); 75 } 76 sendCommand_ = (int (*)(int, char **, char **))dlsym(libh_, set_cmd_func_name); 77 if (sendCommand_ == NULL) { 78 const char *err_str = dlerror(); 79 ALOGE("Error (%s) while searching for the interface command function", err_str ? err_str : "unknown"); 80 return; 81 } 82 } 83 } 84 85 InterfaceController::~InterfaceController() { 86 if (sendCommandFini_) { 87 if (sendCommandFini_()) { 88 ALOGE("Can't shutdown the interface command API"); 89 } 90 } 91 if (libh_) { 92 int err = dlclose(libh_); 93 if (err) { 94 const char *err_str = dlerror(); 95 ALOGE("Error (%s) while closing the net interface command library", err_str ? err_str : "unknown"); 96 } 97 } 98 } 99 100 /* 101 * Arguments: 102 * argv[2] - wlan interface 103 * argv[3] - command 104 * argv[4] - argument 105 * rbuf - returned buffer 106 */ 107 int InterfaceController::interfaceCommand(int argc, char *argv[], char **rbuf) { 108 int ret = -ENOSYS; 109 if (sendCommand_) 110 ret = sendCommand_(argc, argv, rbuf); 111 112 return ret; 113 } 114 115 int InterfaceController::writeIPv6ProcPath(const char *interface, const char *setting, const char *value) { 116 char *path; 117 asprintf(&path, "%s/%s/%s", ipv6_proc_path, interface, setting); 118 int success = writeFile(path, value, strlen(value)); 119 free(path); 120 return success; 121 } 122 123 int InterfaceController::setEnableIPv6(const char *interface, const int on) { 124 // When disable_ipv6 changes from 1 to 0, the kernel starts autoconf. 125 // When disable_ipv6 changes from 0 to 1, the kernel clears all autoconf 126 // addresses and routes and disables IPv6 on the interface. 127 const char *disable_ipv6 = on ? "0" : "1"; 128 return writeIPv6ProcPath(interface, "disable_ipv6", disable_ipv6); 129 } 130 131 int InterfaceController::setIPv6PrivacyExtensions(const char *interface, const int on) { 132 // 0: disable IPv6 privacy addresses 133 // 0: enable IPv6 privacy addresses and prefer them over non-privacy ones. 134 return writeIPv6ProcPath(interface, "use_tempaddr", on ? "2" : "0"); 135 } 136 137 int InterfaceController::isInterfaceName(const char *name) { 138 return strcmp(name, ".") && 139 strcmp(name, "..") && 140 strcmp(name, "default") && 141 strcmp(name, "all"); 142 } 143 144 int InterfaceController::setAcceptRA(const char *value) { 145 // Set the default value, which is used by any interfaces that are created in the future. 146 writeIPv6ProcPath("default", "accept_ra", value); 147 148 // Set the value on all the interfaces. 149 DIR *dir = opendir(ipv6_proc_path); 150 if (!dir) { 151 ALOGE("Can't list %s: %s", ipv6_proc_path, strerror(errno)); 152 return -errno; 153 } 154 struct dirent *d; 155 while((d = readdir(dir)) != NULL) { 156 if (d->d_type == DT_DIR && isInterfaceName(d->d_name)) { 157 if (writeIPv6ProcPath(d->d_name, "accept_ra", value) < 0) { 158 ALOGE("Can't write to %s/%s/accept_ra: %s", ipv6_proc_path, 159 d->d_name, strerror(errno)); 160 } 161 } 162 } 163 closedir(dir); 164 return 0; 165 } 166
