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 <stdlib.h> 18 #include <errno.h> 19 #include <fcntl.h> 20 #include <string.h> 21 22 #include <sys/socket.h> 23 #include <sys/stat.h> 24 #include <sys/types.h> 25 #include <sys/wait.h> 26 27 #include <netinet/in.h> 28 #include <arpa/inet.h> 29 30 #define LOG_TAG "SecondaryTablController" 31 #include <cutils/log.h> 32 #include <cutils/properties.h> 33 34 extern "C" int system_nosh(const char *command); 35 36 #include "ResponseCode.h" 37 #include "NetdConstants.h" 38 #include "SecondaryTableController.h" 39 40 SecondaryTableController::SecondaryTableController() { 41 int i; 42 for (i=0; i < INTERFACES_TRACKED; i++) { 43 mInterfaceTable[i][0] = 0; 44 // TODO - use a hashtable or other prebuilt container class 45 mInterfaceRuleCount[i] = 0; 46 } 47 } 48 49 SecondaryTableController::~SecondaryTableController() { 50 } 51 52 int SecondaryTableController::findTableNumber(const char *iface) { 53 int i; 54 for (i = 0; i < INTERFACES_TRACKED; i++) { 55 // compare through the final null, hence +1 56 if (strncmp(iface, mInterfaceTable[i], IFNAMSIZ + 1) == 0) { 57 return i; 58 } 59 } 60 return -1; 61 } 62 63 int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix, 64 char *gateway) { 65 int tableIndex = findTableNumber(iface); 66 if (tableIndex == -1) { 67 tableIndex = findTableNumber(""); // look for an empty slot 68 if (tableIndex == -1) { 69 ALOGE("Max number of NATed interfaces reached"); 70 errno = ENODEV; 71 cli->sendMsg(ResponseCode::OperationFailed, "Max number NATed", true); 72 return -1; 73 } 74 strncpy(mInterfaceTable[tableIndex], iface, IFNAMSIZ); 75 // Ensure null termination even if truncation happened 76 mInterfaceTable[tableIndex][IFNAMSIZ] = 0; 77 } 78 79 return modifyRoute(cli, ADD, iface, dest, prefix, gateway, tableIndex); 80 } 81 82 int SecondaryTableController::modifyRoute(SocketClient *cli, const char *action, char *iface, 83 char *dest, int prefix, char *gateway, int tableIndex) { 84 char *cmd; 85 86 if (strcmp("::", gateway) == 0) { 87 // IP tool doesn't like "::" - the equiv of 0.0.0.0 that it accepts for ipv4 88 asprintf(&cmd, "%s route %s %s/%d dev %s table %d", 89 IP_PATH, action, dest, prefix, iface, tableIndex+BASE_TABLE_NUMBER); 90 } else { 91 asprintf(&cmd, "%s route %s %s/%d via %s dev %s table %d", 92 IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER); 93 } 94 95 if (runAndFree(cli, cmd)) { 96 ALOGE("ip route %s failed: %s route %s %s/%d via %s dev %s table %d", action, 97 IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER); 98 errno = ENODEV; 99 cli->sendMsg(ResponseCode::OperationFailed, "ip route modification failed", true); 100 return -1; 101 } 102 103 if (strcmp(action, ADD) == 0) { 104 mInterfaceRuleCount[tableIndex]++; 105 } else { 106 if (--mInterfaceRuleCount[tableIndex] < 1) { 107 mInterfaceRuleCount[tableIndex] = 0; 108 mInterfaceTable[tableIndex][0] = 0; 109 } 110 } 111 modifyRuleCount(tableIndex, action); 112 cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false); 113 return 0; 114 } 115 116 void SecondaryTableController::modifyRuleCount(int tableIndex, const char *action) { 117 if (strcmp(action, ADD) == 0) { 118 mInterfaceRuleCount[tableIndex]++; 119 } else { 120 if (--mInterfaceRuleCount[tableIndex] < 1) { 121 mInterfaceRuleCount[tableIndex] = 0; 122 mInterfaceTable[tableIndex][0] = 0; 123 } 124 } 125 } 126 127 int SecondaryTableController::verifyTableIndex(int tableIndex) { 128 if ((tableIndex < 0) || 129 (tableIndex >= INTERFACES_TRACKED) || 130 (mInterfaceTable[tableIndex][0] == 0)) { 131 return -1; 132 } else { 133 return 0; 134 } 135 } 136 137 const char *SecondaryTableController::getVersion(const char *addr) { 138 if (strchr(addr, ':') != NULL) { 139 return "-6"; 140 } else { 141 return "-4"; 142 } 143 } 144 145 int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix, 146 char *gateway) { 147 int tableIndex = findTableNumber(iface); 148 if (tableIndex == -1) { 149 ALOGE("Interface not found"); 150 errno = ENODEV; 151 cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true); 152 return -1; 153 } 154 155 return modifyRoute(cli, DEL, iface, dest, prefix, gateway, tableIndex); 156 } 157 158 int SecondaryTableController::modifyFromRule(int tableIndex, const char *action, 159 const char *addr) { 160 char *cmd; 161 162 if (verifyTableIndex(tableIndex)) { 163 return -1; 164 } 165 asprintf(&cmd, "%s %s rule %s from %s table %d", IP_PATH, getVersion(addr), 166 action, addr, tableIndex + BASE_TABLE_NUMBER); 167 if (runAndFree(NULL, cmd)) { 168 return -1; 169 } 170 171 modifyRuleCount(tableIndex, action); 172 return 0; 173 } 174 175 int SecondaryTableController::modifyLocalRoute(int tableIndex, const char *action, 176 const char *iface, const char *addr) { 177 char *cmd; 178 179 if (verifyTableIndex(tableIndex)) { 180 return -1; 181 } 182 183 modifyRuleCount(tableIndex, action); // some del's will fail as the iface is already gone. 184 185 asprintf(&cmd, "%s route %s %s dev %s table %d", IP_PATH, action, addr, iface, 186 tableIndex+BASE_TABLE_NUMBER); 187 return runAndFree(NULL, cmd); 188 } 189 190 int SecondaryTableController::runAndFree(SocketClient *cli, char *cmd) { 191 int ret = 0; 192 if (strlen(cmd) >= 255) { 193 if (cli != NULL) { 194 ALOGE("ip command (%s) too long", cmd); 195 errno = E2BIG; 196 cli->sendMsg(ResponseCode::CommandSyntaxError, "Too long", true); 197 } 198 free(cmd); 199 return -1; 200 } 201 ret = system_nosh(cmd); 202 free(cmd); 203 return ret; 204 } 205