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 #include <logwrap/logwrap.h> 34 35 #include "ResponseCode.h" 36 #include "NetdConstants.h" 37 #include "SecondaryTableController.h" 38 39 SecondaryTableController::SecondaryTableController() { 40 int i; 41 for (i=0; i < INTERFACES_TRACKED; i++) { 42 mInterfaceTable[i][0] = 0; 43 // TODO - use a hashtable or other prebuilt container class 44 mInterfaceRuleCount[i] = 0; 45 } 46 } 47 48 SecondaryTableController::~SecondaryTableController() { 49 } 50 51 int SecondaryTableController::findTableNumber(const char *iface) { 52 int i; 53 for (i = 0; i < INTERFACES_TRACKED; i++) { 54 // compare through the final null, hence +1 55 if (strncmp(iface, mInterfaceTable[i], IFNAMSIZ + 1) == 0) { 56 return i; 57 } 58 } 59 return -1; 60 } 61 62 int SecondaryTableController::addRoute(SocketClient *cli, char *iface, char *dest, int prefix, 63 char *gateway) { 64 int tableIndex = findTableNumber(iface); 65 if (tableIndex == -1) { 66 tableIndex = findTableNumber(""); // look for an empty slot 67 if (tableIndex == -1) { 68 ALOGE("Max number of NATed interfaces reached"); 69 errno = ENODEV; 70 cli->sendMsg(ResponseCode::OperationFailed, "Max number NATed", true); 71 return -1; 72 } 73 strncpy(mInterfaceTable[tableIndex], iface, IFNAMSIZ); 74 // Ensure null termination even if truncation happened 75 mInterfaceTable[tableIndex][IFNAMSIZ] = 0; 76 } 77 78 return modifyRoute(cli, ADD, iface, dest, prefix, gateway, tableIndex); 79 } 80 81 int SecondaryTableController::modifyRoute(SocketClient *cli, const char *action, char *iface, 82 char *dest, int prefix, char *gateway, int tableIndex) { 83 char dest_str[44]; // enough to store an IPv6 address + 3 character bitmask 84 char tableIndex_str[11]; 85 int ret; 86 87 // IP tool doesn't like "::" - the equiv of 0.0.0.0 that it accepts for ipv4 88 snprintf(dest_str, sizeof(dest_str), "%s/%d", dest, prefix); 89 snprintf(tableIndex_str, sizeof(tableIndex_str), "%d", tableIndex + BASE_TABLE_NUMBER); 90 91 if (strcmp("::", gateway) == 0) { 92 const char *cmd[] = { 93 IP_PATH, 94 "route", 95 action, 96 dest_str, 97 "dev", 98 iface, 99 "table", 100 tableIndex_str 101 }; 102 ret = runCmd(ARRAY_SIZE(cmd), cmd); 103 } else { 104 const char *cmd[] = { 105 IP_PATH, 106 "route", 107 action, 108 dest_str, 109 "via", 110 gateway, 111 "dev", 112 iface, 113 "table", 114 tableIndex_str 115 }; 116 ret = runCmd(ARRAY_SIZE(cmd), cmd); 117 } 118 119 if (ret) { 120 ALOGE("ip route %s failed: %s route %s %s/%d via %s dev %s table %d", action, 121 IP_PATH, action, dest, prefix, gateway, iface, tableIndex+BASE_TABLE_NUMBER); 122 errno = ENODEV; 123 cli->sendMsg(ResponseCode::OperationFailed, "ip route modification failed", true); 124 return -1; 125 } 126 127 if (strcmp(action, ADD) == 0) { 128 mInterfaceRuleCount[tableIndex]++; 129 } else { 130 if (--mInterfaceRuleCount[tableIndex] < 1) { 131 mInterfaceRuleCount[tableIndex] = 0; 132 mInterfaceTable[tableIndex][0] = 0; 133 } 134 } 135 modifyRuleCount(tableIndex, action); 136 cli->sendMsg(ResponseCode::CommandOkay, "Route modified", false); 137 return 0; 138 } 139 140 void SecondaryTableController::modifyRuleCount(int tableIndex, const char *action) { 141 if (strcmp(action, ADD) == 0) { 142 mInterfaceRuleCount[tableIndex]++; 143 } else { 144 if (--mInterfaceRuleCount[tableIndex] < 1) { 145 mInterfaceRuleCount[tableIndex] = 0; 146 mInterfaceTable[tableIndex][0] = 0; 147 } 148 } 149 } 150 151 int SecondaryTableController::verifyTableIndex(int tableIndex) { 152 if ((tableIndex < 0) || 153 (tableIndex >= INTERFACES_TRACKED) || 154 (mInterfaceTable[tableIndex][0] == 0)) { 155 return -1; 156 } else { 157 return 0; 158 } 159 } 160 161 const char *SecondaryTableController::getVersion(const char *addr) { 162 if (strchr(addr, ':') != NULL) { 163 return "-6"; 164 } else { 165 return "-4"; 166 } 167 } 168 169 int SecondaryTableController::removeRoute(SocketClient *cli, char *iface, char *dest, int prefix, 170 char *gateway) { 171 int tableIndex = findTableNumber(iface); 172 if (tableIndex == -1) { 173 ALOGE("Interface not found"); 174 errno = ENODEV; 175 cli->sendMsg(ResponseCode::OperationFailed, "Interface not found", true); 176 return -1; 177 } 178 179 return modifyRoute(cli, DEL, iface, dest, prefix, gateway, tableIndex); 180 } 181 182 int SecondaryTableController::modifyFromRule(int tableIndex, const char *action, 183 const char *addr) { 184 char tableIndex_str[11]; 185 186 if (verifyTableIndex(tableIndex)) { 187 return -1; 188 } 189 190 snprintf(tableIndex_str, sizeof(tableIndex_str), "%d", tableIndex + 191 BASE_TABLE_NUMBER); 192 const char *cmd[] = { 193 IP_PATH, 194 getVersion(addr), 195 "rule", 196 action, 197 "from", 198 addr, 199 "table", 200 tableIndex_str 201 }; 202 if (runCmd(ARRAY_SIZE(cmd), cmd)) { 203 return -1; 204 } 205 206 modifyRuleCount(tableIndex, action); 207 return 0; 208 } 209 210 int SecondaryTableController::modifyLocalRoute(int tableIndex, const char *action, 211 const char *iface, const char *addr) { 212 char tableIndex_str[11]; 213 214 if (verifyTableIndex(tableIndex)) { 215 return -1; 216 } 217 218 modifyRuleCount(tableIndex, action); // some del's will fail as the iface is already gone. 219 220 snprintf(tableIndex_str, sizeof(tableIndex_str), "%d", tableIndex + 221 BASE_TABLE_NUMBER); 222 const char *cmd[] = { 223 IP_PATH, 224 "route", 225 action, 226 addr, 227 "dev", 228 iface, 229 "table", 230 tableIndex_str 231 }; 232 233 return runCmd(ARRAY_SIZE(cmd), cmd); 234 } 235 236 int SecondaryTableController::runCmd(int argc, const char **argv) { 237 int ret = 0; 238 239 ret = android_fork_execvp(argc, (char **)argv, NULL, false, false); 240 return ret; 241 } 242
