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 <dirent.h> 18 #include <errno.h> 19 #include <malloc.h> 20 #include <sys/socket.h> 21 22 #define LOG_TAG "InterfaceController" 23 #include <android-base/file.h> 24 #include <android-base/stringprintf.h> 25 #include <cutils/log.h> 26 #include <logwrap/logwrap.h> 27 #include <netutils/ifc.h> 28 29 #include "InterfaceController.h" 30 #include "RouteController.h" 31 32 using android::base::StringPrintf; 33 using android::base::ReadFileToString; 34 using android::base::WriteStringToFile; 35 36 namespace { 37 38 const char ipv6_proc_path[] = "/proc/sys/net/ipv6/conf"; 39 40 const char ipv4_neigh_conf_dir[] = "/proc/sys/net/ipv4/neigh"; 41 42 const char ipv6_neigh_conf_dir[] = "/proc/sys/net/ipv6/neigh"; 43 44 const char proc_net_path[] = "/proc/sys/net"; 45 const char sys_net_path[] = "/sys/class/net"; 46 47 const char wl_util_path[] = "/vendor/xbin/wlutil"; 48 49 inline bool isNormalPathComponent(const char *component) { 50 return (strcmp(component, ".") != 0) && 51 (strcmp(component, "..") != 0) && 52 (strchr(component, '/') == nullptr); 53 } 54 55 inline bool isAddressFamilyPathComponent(const char *component) { 56 return strcmp(component, "ipv4") == 0 || strcmp(component, "ipv6") == 0; 57 } 58 59 inline bool isInterfaceName(const char *name) { 60 return isNormalPathComponent(name) && 61 (strcmp(name, "default") != 0) && 62 (strcmp(name, "all") != 0); 63 } 64 65 int writeValueToPath( 66 const char* dirname, const char* subdirname, const char* basename, 67 const char* value) { 68 std::string path(StringPrintf("%s/%s/%s", dirname, subdirname, basename)); 69 return WriteStringToFile(value, path) ? 0 : -1; 70 } 71 72 void setOnAllInterfaces(const char* dirname, const char* basename, const char* value) { 73 // Set the default value, which is used by any interfaces that are created in the future. 74 writeValueToPath(dirname, "default", basename, value); 75 76 // Set the value on all the interfaces that currently exist. 77 DIR* dir = opendir(dirname); 78 if (!dir) { 79 ALOGE("Can't list %s: %s", dirname, strerror(errno)); 80 return; 81 } 82 dirent* d; 83 while ((d = readdir(dir))) { 84 if ((d->d_type != DT_DIR) || !isInterfaceName(d->d_name)) { 85 continue; 86 } 87 writeValueToPath(dirname, d->d_name, basename, value); 88 } 89 closedir(dir); 90 } 91 92 void setIPv6UseOutgoingInterfaceAddrsOnly(const char *value) { 93 setOnAllInterfaces(ipv6_proc_path, "use_oif_addrs_only", value); 94 } 95 96 std::string getParameterPathname( 97 const char *family, const char *which, const char *interface, const char *parameter) { 98 if (!isAddressFamilyPathComponent(family)) { 99 errno = EAFNOSUPPORT; 100 return ""; 101 } else if (!isNormalPathComponent(which) || 102 !isInterfaceName(interface) || 103 !isNormalPathComponent(parameter)) { 104 errno = EINVAL; 105 return ""; 106 } 107 108 return StringPrintf("%s/%s/%s/%s/%s", proc_net_path, family, which, interface, parameter); 109 } 110 111 } // namespace 112 113 void InterfaceController::initializeAll() { 114 // Initial IPv6 settings. 115 // By default, accept_ra is set to 1 (accept RAs unless forwarding is on) on all interfaces. 116 // This causes RAs to work or not work based on whether forwarding is on, and causes routes 117 // learned from RAs to go away when forwarding is turned on. Make this behaviour predictable 118 // by always setting accept_ra to 2. 119 setAcceptRA("2"); 120 121 setAcceptRARouteTable(-RouteController::ROUTE_TABLE_OFFSET_FROM_INDEX); 122 123 // Enable optimistic DAD for IPv6 addresses on all interfaces. 124 setIPv6OptimisticMode("1"); 125 126 // Reduce the ARP/ND base reachable time from the default (30sec) to 15sec. 127 setBaseReachableTimeMs(15 * 1000); 128 129 // When sending traffic via a given interface use only addresses configured 130 // on that interface as possible source addresses. 131 setIPv6UseOutgoingInterfaceAddrsOnly("1"); 132 } 133 134 int InterfaceController::setEnableIPv6(const char *interface, const int on) { 135 if (!isIfaceName(interface)) { 136 errno = ENOENT; 137 return -1; 138 } 139 // When disable_ipv6 changes from 1 to 0, the kernel starts autoconf. 140 // When disable_ipv6 changes from 0 to 1, the kernel clears all autoconf 141 // addresses and routes and disables IPv6 on the interface. 142 const char *disable_ipv6 = on ? "0" : "1"; 143 return writeValueToPath(ipv6_proc_path, interface, "disable_ipv6", disable_ipv6); 144 } 145 146 int InterfaceController::setAcceptIPv6Ra(const char *interface, const int on) { 147 if (!isIfaceName(interface)) { 148 errno = ENOENT; 149 return -1; 150 } 151 // Because forwarding can be enabled even when tethering is off, we always 152 // use mode "2" (accept RAs, even if forwarding is enabled). 153 const char *accept_ra = on ? "2" : "0"; 154 return writeValueToPath(ipv6_proc_path, interface, "accept_ra", accept_ra); 155 } 156 157 int InterfaceController::setAcceptIPv6Dad(const char *interface, const int on) { 158 if (!isIfaceName(interface)) { 159 errno = ENOENT; 160 return -1; 161 } 162 const char *accept_dad = on ? "1" : "0"; 163 return writeValueToPath(ipv6_proc_path, interface, "accept_dad", accept_dad); 164 } 165 166 int InterfaceController::setIPv6DadTransmits(const char *interface, const char *value) { 167 if (!isIfaceName(interface)) { 168 errno = ENOENT; 169 return -1; 170 } 171 return writeValueToPath(ipv6_proc_path, interface, "dad_transmits", value); 172 } 173 174 int InterfaceController::setIPv6PrivacyExtensions(const char *interface, const int on) { 175 if (!isIfaceName(interface)) { 176 errno = ENOENT; 177 return -1; 178 } 179 // 0: disable IPv6 privacy addresses 180 // 0: enable IPv6 privacy addresses and prefer them over non-privacy ones. 181 return writeValueToPath(ipv6_proc_path, interface, "use_tempaddr", on ? "2" : "0"); 182 } 183 184 // Enables or disables IPv6 ND offload. This is useful for 464xlat on wifi, IPv6 tethering, and 185 // generally implementing IPv6 neighbour discovery and duplicate address detection properly. 186 // TODO: This should be implemented in wpa_supplicant via driver commands instead. 187 int InterfaceController::setIPv6NdOffload(char* interface, const int on) { 188 // Only supported on Broadcom chipsets via wlutil for now. 189 if (access(wl_util_path, X_OK) == 0) { 190 const char *argv[] = { 191 wl_util_path, 192 "-a", 193 interface, 194 "ndoe", 195 on ? "1" : "0" 196 }; 197 int ret = android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, 198 false, false); 199 ALOGD("%s ND offload on %s: %d (%s)", 200 (on ? "enabling" : "disabling"), interface, ret, strerror(errno)); 201 return ret; 202 } else { 203 return 0; 204 } 205 } 206 207 void InterfaceController::setAcceptRA(const char *value) { 208 setOnAllInterfaces(ipv6_proc_path, "accept_ra", value); 209 } 210 211 // |tableOrOffset| is interpreted as: 212 // If == 0: default. Routes go into RT6_TABLE_MAIN. 213 // If > 0: user set. Routes go into the specified table. 214 // If < 0: automatic. The absolute value is intepreted as an offset and added to the interface 215 // ID to get the table. If it's set to -1000, routes from interface ID 5 will go into 216 // table 1005, etc. 217 void InterfaceController::setAcceptRARouteTable(int tableOrOffset) { 218 std::string value(StringPrintf("%d", tableOrOffset)); 219 setOnAllInterfaces(ipv6_proc_path, "accept_ra_rt_table", value.c_str()); 220 } 221 222 int InterfaceController::setMtu(const char *interface, const char *mtu) 223 { 224 if (!isIfaceName(interface)) { 225 errno = ENOENT; 226 return -1; 227 } 228 return writeValueToPath(sys_net_path, interface, "mtu", mtu); 229 } 230 231 int InterfaceController::addAddress(const char *interface, 232 const char *addrString, int prefixLength) { 233 return ifc_add_address(interface, addrString, prefixLength); 234 } 235 236 int InterfaceController::delAddress(const char *interface, 237 const char *addrString, int prefixLength) { 238 return ifc_del_address(interface, addrString, prefixLength); 239 } 240 241 int InterfaceController::getParameter( 242 const char *family, const char *which, const char *interface, const char *parameter, 243 std::string *value) { 244 const std::string path(getParameterPathname(family, which, interface, parameter)); 245 if (path.empty()) { 246 return -errno; 247 } 248 return ReadFileToString(path, value) ? 0 : -errno; 249 } 250 251 int InterfaceController::setParameter( 252 const char *family, const char *which, const char *interface, const char *parameter, 253 const char *value) { 254 const std::string path(getParameterPathname(family, which, interface, parameter)); 255 if (path.empty()) { 256 return -errno; 257 } 258 return WriteStringToFile(value, path) ? 0 : -errno; 259 } 260 261 void InterfaceController::setBaseReachableTimeMs(unsigned int millis) { 262 std::string value(StringPrintf("%u", millis)); 263 setOnAllInterfaces(ipv4_neigh_conf_dir, "base_reachable_time_ms", value.c_str()); 264 setOnAllInterfaces(ipv6_neigh_conf_dir, "base_reachable_time_ms", value.c_str()); 265 } 266 267 void InterfaceController::setIPv6OptimisticMode(const char *value) { 268 setOnAllInterfaces(ipv6_proc_path, "optimistic_dad", value); 269 setOnAllInterfaces(ipv6_proc_path, "use_optimistic", value); 270 } 271
