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 const char sys_net_path[] = "/sys/class/net"; 50 51 InterfaceController::InterfaceController() 52 : sendCommand_(NULL) { 53 // Initial IPv6 settings. 54 // By default, accept_ra is set to 1 (accept RAs unless forwarding is on) on all interfaces. 55 // This causes RAs to work or not work based on whether forwarding is on, and causes routes 56 // learned from RAs to go away when forwarding is turned on. Make this behaviour predictable 57 // by always setting accept_ra to 2. 58 setAcceptRA("2"); 59 60 libh_ = dlopen(if_cmd_lib_file_name, RTLD_NOW | RTLD_LOCAL); 61 if (libh_ == NULL) { 62 const char *err_str = dlerror(); 63 ALOGW("Warning (%s) while opening the net interface command library", err_str ? err_str : "unknown"); 64 } else { 65 sendCommandInit_ = (int (*)(void))dlsym(libh_, set_cmd_init_func_name); 66 if (sendCommandInit_ == NULL) { 67 const char *err_str = dlerror(); 68 ALOGW("Error (%s) while searching for the interface command init function", err_str ? err_str : "unknown"); 69 } else if (sendCommandInit_()) { 70 ALOGE("Can't init the interface command API"); 71 return; 72 } 73 sendCommandFini_ = (int (*)(void))dlsym(libh_, set_cmd_fini_func_name); 74 if (sendCommandFini_ == NULL) { 75 const char *err_str = dlerror(); 76 ALOGW("Error (%s) while searching for the interface command fini function", err_str ? err_str : "unknown"); 77 } 78 sendCommand_ = (int (*)(int, char **, char **))dlsym(libh_, set_cmd_func_name); 79 if (sendCommand_ == NULL) { 80 const char *err_str = dlerror(); 81 ALOGE("Error (%s) while searching for the interface command function", err_str ? err_str : "unknown"); 82 return; 83 } 84 } 85 } 86 87 InterfaceController::~InterfaceController() { 88 if (sendCommandFini_) { 89 if (sendCommandFini_()) { 90 ALOGE("Can't shutdown the interface command API"); 91 } 92 } 93 if (libh_) { 94 int err = dlclose(libh_); 95 if (err) { 96 const char *err_str = dlerror(); 97 ALOGE("Error (%s) while closing the net interface command library", err_str ? err_str : "unknown"); 98 } 99 } 100 } 101 102 /* 103 * Arguments: 104 * argv[2] - wlan interface 105 * argv[3] - command 106 * argv[4] - argument 107 * rbuf - returned buffer 108 */ 109 int InterfaceController::interfaceCommand(int argc, char *argv[], char **rbuf) { 110 int ret = -ENOSYS; 111 if (sendCommand_) 112 ret = sendCommand_(argc, argv, rbuf); 113 114 return ret; 115 } 116 117 int InterfaceController::writeIPv6ProcPath(const char *interface, const char *setting, const char *value) { 118 char *path; 119 asprintf(&path, "%s/%s/%s", ipv6_proc_path, interface, setting); 120 int success = writeFile(path, value, strlen(value)); 121 free(path); 122 return success; 123 } 124 125 int InterfaceController::setEnableIPv6(const char *interface, const int on) { 126 // When disable_ipv6 changes from 1 to 0, the kernel starts autoconf. 127 // When disable_ipv6 changes from 0 to 1, the kernel clears all autoconf 128 // addresses and routes and disables IPv6 on the interface. 129 const char *disable_ipv6 = on ? "0" : "1"; 130 return writeIPv6ProcPath(interface, "disable_ipv6", disable_ipv6); 131 } 132 133 int InterfaceController::setIPv6PrivacyExtensions(const char *interface, const int on) { 134 // 0: disable IPv6 privacy addresses 135 // 0: enable IPv6 privacy addresses and prefer them over non-privacy ones. 136 return writeIPv6ProcPath(interface, "use_tempaddr", on ? "2" : "0"); 137 } 138 139 int InterfaceController::isInterfaceName(const char *name) { 140 return strcmp(name, ".") && 141 strcmp(name, "..") && 142 strcmp(name, "default") && 143 strcmp(name, "all"); 144 } 145 146 int InterfaceController::setAcceptRA(const char *value) { 147 // Set the default value, which is used by any interfaces that are created in the future. 148 writeIPv6ProcPath("default", "accept_ra", value); 149 150 // Set the value on all the interfaces. 151 DIR *dir = opendir(ipv6_proc_path); 152 if (!dir) { 153 ALOGE("Can't list %s: %s", ipv6_proc_path, strerror(errno)); 154 return -errno; 155 } 156 struct dirent *d; 157 while((d = readdir(dir)) != NULL) { 158 if (d->d_type == DT_DIR && isInterfaceName(d->d_name)) { 159 if (writeIPv6ProcPath(d->d_name, "accept_ra", value) < 0) { 160 ALOGE("Can't write to %s/%s/accept_ra: %s", ipv6_proc_path, 161 d->d_name, strerror(errno)); 162 } 163 } 164 } 165 closedir(dir); 166 return 0; 167 } 168 169 int InterfaceController::getMtu(const char *interface, int *mtu) 170 { 171 char buf[16]; 172 int size = sizeof(buf); 173 char *path; 174 asprintf(&path, "%s/%s/mtu", sys_net_path, interface); 175 int success = readFile(path, buf, &size); 176 if (!success && mtu) 177 *mtu = atoi(buf); 178 free(path); 179 return success; 180 181 } 182 183 int InterfaceController::setMtu(const char *interface, const char *mtu) 184 { 185 char *path; 186 asprintf(&path, "%s/%s/mtu", sys_net_path, interface); 187 int success = writeFile(path, mtu, strlen(mtu)); 188 free(path); 189 return success; 190 } 191
