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 21#define LOG_TAG "InterfaceController" 22#include <base/file.h> 23#include <base/stringprintf.h> 24#include <cutils/log.h> 25#include <logwrap/logwrap.h> 26 27#include "InterfaceController.h" 28#include "RouteController.h" 29 30using android::base::StringPrintf; 31using android::base::WriteStringToFile; 32 33namespace { 34 35const char ipv6_proc_path[] = "/proc/sys/net/ipv6/conf"; 36 37const char ipv4_neigh_conf_dir[] = "/proc/sys/net/ipv4/neigh"; 38 39const char ipv6_neigh_conf_dir[] = "/proc/sys/net/ipv6/neigh"; 40 41const char sys_net_path[] = "/sys/class/net"; 42 43const char wl_util_path[] = "/system/xbin/wlutil"; 44 45bool isInterfaceName(const char *name) { 46 return strcmp(name, ".") && 47 strcmp(name, "..") && 48 strcmp(name, "default") && 49 strcmp(name, "all"); 50} 51 52int writeValueToPath( 53 const char* dirname, const char* subdirname, const char* basename, 54 const char* value) { 55 std::string path(StringPrintf("%s/%s/%s", dirname, subdirname, basename)); 56 return WriteStringToFile(value, path) ? 0 : -1; 57} 58 59void setOnAllInterfaces(const char* dirname, const char* basename, const char* value) { 60 // Set the default value, which is used by any interfaces that are created in the future. 61 writeValueToPath(dirname, "default", basename, value); 62 63 // Set the value on all the interfaces that currently exist. 64 DIR* dir = opendir(dirname); 65 if (!dir) { 66 ALOGE("Can't list %s: %s", dirname, strerror(errno)); 67 return; 68 } 69 dirent* d; 70 while ((d = readdir(dir))) { 71 if ((d->d_type != DT_DIR) || !isInterfaceName(d->d_name)) { 72 continue; 73 } 74 writeValueToPath(dirname, d->d_name, basename, value); 75 } 76 closedir(dir); 77} 78 79void setIPv6UseOutgoingInterfaceAddrsOnly(const char *value) { 80 setOnAllInterfaces(ipv6_proc_path, "use_oif_addrs_only", value); 81} 82 83} // namespace 84 85InterfaceController::InterfaceController() { 86 // Initial IPv6 settings. 87 // By default, accept_ra is set to 1 (accept RAs unless forwarding is on) on all interfaces. 88 // This causes RAs to work or not work based on whether forwarding is on, and causes routes 89 // learned from RAs to go away when forwarding is turned on. Make this behaviour predictable 90 // by always setting accept_ra to 2. 91 setAcceptRA("2"); 92 93 setAcceptRARouteTable(-RouteController::ROUTE_TABLE_OFFSET_FROM_INDEX); 94 95 // Enable optimistic DAD for IPv6 addresses on all interfaces. 96 setIPv6OptimisticMode("1"); 97 98 // Reduce the ARP/ND base reachable time from the default (30sec) to 15sec. 99 setBaseReachableTimeMs(15 * 1000); 100 101 // When sending traffic via a given interface use only addresses configured 102 // on that interface as possible source addresses. 103 setIPv6UseOutgoingInterfaceAddrsOnly("1"); 104} 105 106InterfaceController::~InterfaceController() { 107} 108 109int InterfaceController::setEnableIPv6(const char *interface, const int on) { 110 if (!isIfaceName(interface)) { 111 errno = ENOENT; 112 return -1; 113 } 114 // When disable_ipv6 changes from 1 to 0, the kernel starts autoconf. 115 // When disable_ipv6 changes from 0 to 1, the kernel clears all autoconf 116 // addresses and routes and disables IPv6 on the interface. 117 const char *disable_ipv6 = on ? "0" : "1"; 118 return writeValueToPath(ipv6_proc_path, interface, "disable_ipv6", disable_ipv6); 119} 120 121int InterfaceController::setIPv6PrivacyExtensions(const char *interface, const int on) { 122 if (!isIfaceName(interface)) { 123 errno = ENOENT; 124 return -1; 125 } 126 // 0: disable IPv6 privacy addresses 127 // 0: enable IPv6 privacy addresses and prefer them over non-privacy ones. 128 return writeValueToPath(ipv6_proc_path, interface, "use_tempaddr", on ? "2" : "0"); 129} 130 131// Enables or disables IPv6 ND offload. This is useful for 464xlat on wifi, IPv6 tethering, and 132// generally implementing IPv6 neighbour discovery and duplicate address detection properly. 133// TODO: This should be implemented in wpa_supplicant via driver commands instead. 134int InterfaceController::setIPv6NdOffload(char* interface, const int on) { 135 // Only supported on Broadcom chipsets via wlutil for now. 136 if (access(wl_util_path, X_OK) == 0) { 137 const char *argv[] = { 138 wl_util_path, 139 "-a", 140 interface, 141 "ndoe", 142 on ? "1" : "0" 143 }; 144 int ret = android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, 145 false, false); 146 ALOGD("%s ND offload on %s: %d (%s)", 147 (on ? "enabling" : "disabling"), interface, ret, strerror(errno)); 148 return ret; 149 } else { 150 return 0; 151 } 152} 153 154void InterfaceController::setAcceptRA(const char *value) { 155 setOnAllInterfaces(ipv6_proc_path, "accept_ra", value); 156} 157 158// |tableOrOffset| is interpreted as: 159// If == 0: default. Routes go into RT6_TABLE_MAIN. 160// If > 0: user set. Routes go into the specified table. 161// If < 0: automatic. The absolute value is intepreted as an offset and added to the interface 162// ID to get the table. If it's set to -1000, routes from interface ID 5 will go into 163// table 1005, etc. 164void InterfaceController::setAcceptRARouteTable(int tableOrOffset) { 165 std::string value(StringPrintf("%d", tableOrOffset)); 166 setOnAllInterfaces(ipv6_proc_path, "accept_ra_rt_table", value.c_str()); 167} 168 169int InterfaceController::setMtu(const char *interface, const char *mtu) 170{ 171 if (!isIfaceName(interface)) { 172 errno = ENOENT; 173 return -1; 174 } 175 return writeValueToPath(sys_net_path, interface, "mtu", mtu); 176} 177 178void InterfaceController::setBaseReachableTimeMs(unsigned int millis) { 179 std::string value(StringPrintf("%u", millis)); 180 setOnAllInterfaces(ipv4_neigh_conf_dir, "base_reachable_time_ms", value.c_str()); 181 setOnAllInterfaces(ipv6_neigh_conf_dir, "base_reachable_time_ms", value.c_str()); 182} 183 184void InterfaceController::setIPv6OptimisticMode(const char *value) { 185 setOnAllInterfaces(ipv6_proc_path, "optimistic_dad", value); 186 setOnAllInterfaces(ipv6_proc_path, "use_optimistic", value); 187} 188