RouteController.cpp revision 95684ba176a9fe5ea59207d7202e47fa12bbfdbe
169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal/* 269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * Copyright (C) 2014 The Android Open Source Project 369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * 469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * Licensed under the Apache License, Version 2.0 (the "License"); 569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * you may not use this file except in compliance with the License. 669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * You may obtain a copy of the License at 769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * 869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * http://www.apache.org/licenses/LICENSE-2.0 969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * 1069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * Unless required by applicable law or agreed to in writing, software 1169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * distributed under the License is distributed on an "AS IS" BASIS, 1269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 1369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * See the License for the specific language governing permissions and 1469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal * limitations under the License. 1569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal */ 1669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 1769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "RouteController.h" 1869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 1969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "Fwmark.h" 2069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "UidRanges.h" 2169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 2269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#define LOG_TAG "Netd" 2369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "log/log.h" 2469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "logwrap/logwrap.h" 2569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include "resolv_netid.h" 2669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 2769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <arpa/inet.h> 2869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <fcntl.h> 2969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <linux/fib_rules.h> 3069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <map> 3169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <net/if.h> 3269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal#include <sys/stat.h> 3369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 3469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalnamespace { 3569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 3669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// BEGIN CONSTANTS -------------------------------------------------------------------------------- 3769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 3869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_VPN_OVERRIDE_SYSTEM = 10000; 3969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_VPN_OUTPUT_TO_LOCAL = 11000; 4069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_SECURE_VPN = 12000; 4169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_EXPLICIT_NETWORK = 13000; 4269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_OUTPUT_INTERFACE = 14000; 4369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_LEGACY_SYSTEM = 15000; 4469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_LEGACY_NETWORK = 16000; 4569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_LOCAL_NETWORK = 17000; 4669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_TETHERING = 18000; 4769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_IMPLICIT_NETWORK = 19000; 4869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_BYPASSABLE_VPN = 20000; 4969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// const uint32_t RULE_PRIORITY_VPN_FALLTHROUGH = 21000; 5069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_DEFAULT_NETWORK = 22000; 5169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_DIRECTLY_CONNECTED = 23000; 5269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t RULE_PRIORITY_UNREACHABLE = 24000; 5369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 5469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t ROUTE_TABLE_LOCAL_NETWORK = 97; 5569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t ROUTE_TABLE_LEGACY_NETWORK = 98; 5669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint32_t ROUTE_TABLE_LEGACY_SYSTEM = 99; 5769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 5869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const ROUTE_TABLE_NAME_LOCAL_NETWORK = "local_network"; 5969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const ROUTE_TABLE_NAME_LEGACY_NETWORK = "legacy_network"; 6069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const ROUTE_TABLE_NAME_LEGACY_SYSTEM = "legacy_system"; 6169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 6269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const ROUTE_TABLE_NAME_LOCAL = "local"; 6369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const ROUTE_TABLE_NAME_MAIN = "main"; 6469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 6569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// TODO: These values aren't defined by the Linux kernel, because our UID routing changes are not 6669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// upstream (yet?), so we can't just pick them up from kernel headers. When (if?) the changes make 6769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// it upstream, we'll remove this and rely on the kernel header values. For now, add a static assert 6869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// that will warn us if upstream has given these values some other meaning. 6969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint16_t FRA_UID_START = 18; 7069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint16_t FRA_UID_END = 19; 7169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalstatic_assert(FRA_UID_START > FRA_MAX, 7269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal "Android-specific FRA_UID_{START,END} values also assigned in Linux uapi. " 7369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal "Check that these values match what the kernel does and then update this assertion."); 7469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 7569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint16_t NETLINK_REQUEST_FLAGS = NLM_F_REQUEST | NLM_F_ACK; 7669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint16_t NETLINK_CREATE_REQUEST_FLAGS = NETLINK_REQUEST_FLAGS | NLM_F_CREATE | NLM_F_EXCL; 7769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 7869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst sockaddr_nl NETLINK_ADDRESS = {AF_NETLINK, 0, 0, 0}; 7969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 8069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uint8_t AF_FAMILIES[] = {AF_INET, AF_INET6}; 8169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 8269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const IP_VERSIONS[] = {"-4", "-6"}; 8369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 8469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst uid_t UID_ROOT = 0; 8569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const IIF_NONE = NULL; 8669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const OIF_NONE = NULL; 8769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst bool ACTION_ADD = true; 8869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst bool ACTION_DEL = false; 8969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst bool MODIFY_NON_UID_BASED_RULES = true; 9069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 9169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst char* const RT_TABLES_PATH = "/data/misc/net/rt_tables"; 9269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst int RT_TABLES_FLAGS = O_CREAT | O_TRUNC | O_WRONLY | O_NOFOLLOW | O_CLOEXEC; 9369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconst mode_t RT_TABLES_MODE = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH; // mode 0644, rw-r--r-- 9469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 9569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Avoids "non-constant-expression cannot be narrowed from type 'unsigned int' to 'unsigned short'" 9669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// warnings when using RTA_LENGTH(x) inside static initializers (even when x is already uint16_t). 9769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalconstexpr uint16_t U16_RTA_LENGTH(uint16_t x) { 9869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return RTA_LENGTH(x); 9969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 10069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 10169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// These are practically const, but can't be declared so, because they are used to initialize 10269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// non-const pointers ("void* iov_base") in iovec arrays. 10369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_PRIORITY = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_PRIORITY }; 10469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_TABLE = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_TABLE }; 10569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_FWMARK = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_FWMARK }; 10669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_FWMASK = { U16_RTA_LENGTH(sizeof(uint32_t)), FRA_FWMASK }; 10769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_UID_START = { U16_RTA_LENGTH(sizeof(uid_t)), FRA_UID_START }; 10869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr FRATTR_UID_END = { U16_RTA_LENGTH(sizeof(uid_t)), FRA_UID_END }; 10969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 11069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr RTATTR_TABLE = { U16_RTA_LENGTH(sizeof(uint32_t)), RTA_TABLE }; 11169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalrtattr RTATTR_OIF = { U16_RTA_LENGTH(sizeof(uint32_t)), RTA_OIF }; 11269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 11369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigaluint8_t PADDING_BUFFER[RTA_ALIGNTO] = {0, 0, 0, 0}; 11469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 11569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// END CONSTANTS ---------------------------------------------------------------------------------- 11669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 11769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// No locks needed because RouteController is accessed only from one thread (in CommandListener). 11869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalstd::map<std::string, uint32_t> interfaceToTable; 11969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 12069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigaluint32_t getRouteTableForInterface(const char* interface) { 12169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal uint32_t index = if_nametoindex(interface); 12269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (index) { 12369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal index += RouteController::ROUTE_TABLE_OFFSET_FROM_INDEX; 12469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal interfaceToTable[interface] = index; 12569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return index; 12669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 12769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // If the interface goes away if_nametoindex() will return 0 but we still need to know 12869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // the index so we can remove the rules and routes. 12969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal auto iter = interfaceToTable.find(interface); 13069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (iter == interfaceToTable.end()) { 13169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("cannot find interface %s", interface); 13269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return RT_TABLE_UNSPEC; 13369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 13469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return iter->second; 13569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 13669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 13769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalvoid addTableName(uint32_t table, const std::string& name, std::string* contents) { 13869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal char tableString[UINT32_STRLEN]; 13969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal snprintf(tableString, sizeof(tableString), "%u", table); 14069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *contents += tableString; 14169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *contents += " "; 14269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *contents += name; 14369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *contents += "\n"; 14469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 14569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 14669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Doesn't return success/failure as the file is optional; it's okay if we fail to update it. 14769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalvoid updateTableNamesFile() { 14869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal std::string contents; 14969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 15069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(RT_TABLE_LOCAL, ROUTE_TABLE_NAME_LOCAL, &contents); 15169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(RT_TABLE_MAIN, ROUTE_TABLE_NAME_MAIN, &contents); 15269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 15369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(ROUTE_TABLE_LOCAL_NETWORK, ROUTE_TABLE_NAME_LOCAL_NETWORK, &contents); 15469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(ROUTE_TABLE_LEGACY_NETWORK, ROUTE_TABLE_NAME_LEGACY_NETWORK, &contents); 15569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(ROUTE_TABLE_LEGACY_SYSTEM, ROUTE_TABLE_NAME_LEGACY_SYSTEM, &contents); 15669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 15769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal for (const auto& entry : interfaceToTable) { 15869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal addTableName(entry.second, entry.first, &contents); 15969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 16069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 16169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal int fd = open(RT_TABLES_PATH, RT_TABLES_FLAGS, RT_TABLES_MODE); 16269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (fd == -1) { 16369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("failed to create %s (%s)", RT_TABLES_PATH, strerror(errno)); 16469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return; 16569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 16669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // File creation is affected by umask, so make sure the right mode bits are set. 16769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (fchmod(fd, RT_TABLES_MODE) == -1) { 16869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("failed to set mode 0%o on %s (%s)", RT_TABLES_MODE, RT_TABLES_PATH, strerror(errno)); 16969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 17069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ssize_t bytesWritten = write(fd, contents.data(), contents.size()); 17169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (bytesWritten != static_cast<ssize_t>(contents.size())) { 17269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("failed to write to %s (%zd vs %zu bytes) (%s)", RT_TABLES_PATH, bytesWritten, 17369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal contents.size(), strerror(errno)); 17469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 17569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal close(fd); 17669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 17769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 17869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Sends a netlink request and expects an ack. 17969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// |iov| is an array of struct iovec that contains the netlink message payload. 18069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// The netlink header is generated by this function based on |action| and |flags|. 18169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Returns -errno if there was an error or if the kernel reported an error. 18269e17611504376e4d4603925f8528dfc890fd2c6Luis SigalWARN_UNUSED_RESULT int sendNetlinkRequest(uint16_t action, uint16_t flags, iovec* iov, int iovlen) { 18369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal nlmsghdr nlmsg = { 18469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal .nlmsg_type = action, 18569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal .nlmsg_flags = flags, 18669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal }; 18769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal iov[0].iov_base = &nlmsg; 18869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal iov[0].iov_len = sizeof(nlmsg); 18969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal for (int i = 0; i < iovlen; ++i) { 19069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal nlmsg.nlmsg_len += iov[i].iov_len; 19169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 19269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 19369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal int ret; 19469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal struct { 19569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal nlmsghdr msg; 19669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal nlmsgerr err; 19769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } response; 19869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 19969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal int sock = socket(AF_NETLINK, SOCK_DGRAM, NETLINK_ROUTE); 20069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (sock != -1 && 20169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal connect(sock, reinterpret_cast<const sockaddr*>(&NETLINK_ADDRESS), 20269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal sizeof(NETLINK_ADDRESS)) != -1 && 20369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal writev(sock, iov, iovlen) != -1 && 20469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal (ret = recv(sock, &response, sizeof(response), 0)) != -1) { 20569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (ret == sizeof(response)) { 20669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ret = response.err.error; // Netlink errors are negative errno. 20769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (ret) { 20869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("netlink response contains error (%s)", strerror(-ret)); 20969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 21069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } else { 21169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("bad netlink response message size (%d != %zu)", ret, sizeof(response)); 21269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ret = -EBADMSG; 21369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 21469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } else { 21569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("netlink socket/connect/writev/recv failed (%s)", strerror(errno)); 21669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ret = -errno; 21769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 21869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 21969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (sock != -1) { 22069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal close(sock); 22169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 22269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 22369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return ret; 22469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 22569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 22669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Returns 0 on success or negative errno on failure. 22769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigalint padInterfaceName(const char* input, char* name, size_t* length, uint16_t* padding) { 22869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (!input) { 22969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *length = 0; 23069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *padding = 0; 23169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return 0; 23269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 23369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *length = strlcpy(name, input, IFNAMSIZ) + 1; 23469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (*length > IFNAMSIZ) { 23569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("interface name too long (%zu > %u)", *length, IFNAMSIZ); 23669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return -ENAMETOOLONG; 23769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 23869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal *padding = RTA_SPACE(*length) - RTA_LENGTH(*length); 23969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return 0; 24069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal} 24169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 24269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Adds or removes a routing rule for IPv4 and IPv6. 24369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// 24469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// + If |table| is non-zero, the rule points at the specified routing table. Otherwise, the rule 24569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// returns ENETUNREACH. 24669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// + If |mask| is non-zero, the rule matches the specified fwmark and mask. Otherwise, |fwmark| is 24769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// ignored. 24869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// + If |iif| is non-NULL, the rule matches the specified incoming interface. 24969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// + If |oif| is non-NULL, the rule matches the specified outgoing interface. 25069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// + If |uidStart| and |uidEnd| are not INVALID_UID, the rule matches packets from UIDs in that 25169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// range (inclusive). Otherwise, the rule matches packets from all UIDs. 25269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// 25369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal// Returns 0 on success or negative errno on failure. 25469e17611504376e4d4603925f8528dfc890fd2c6Luis SigalWARN_UNUSED_RESULT int modifyIpRule(uint16_t action, uint32_t priority, uint32_t table, 25569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal uint32_t fwmark, uint32_t mask, const char* iif, 25669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal const char* oif, uid_t uidStart, uid_t uidEnd) { 25769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // Ensure that if you set a bit in the fwmark, it's not being ignored by the mask. 25869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (fwmark & ~mask) { 25969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal ALOGE("mask 0x%x does not select all the bits set in fwmark 0x%x", mask, fwmark); 26069e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return -ERANGE; 26169e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal } 26269e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal 26369e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // Interface names must include exactly one terminating NULL and be properly padded, or older 26469e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal // kernels will refuse to delete rules. 26569e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal char iifName[IFNAMSIZ], oifName[IFNAMSIZ]; 26669e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal size_t iifLength, oifLength; 26769e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal uint16_t iifPadding, oifPadding; 26869e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal if (int ret = padInterfaceName(iif, iifName, &iifLength, &iifPadding)) { 26969e17611504376e4d4603925f8528dfc890fd2c6Luis Sigal return ret; 270 } 271 if (int ret = padInterfaceName(oif, oifName, &oifLength, &oifPadding)) { 272 return ret; 273 } 274 275 // Either both start and end UID must be specified, or neither. 276 if ((uidStart == INVALID_UID) != (uidEnd == INVALID_UID)) { 277 ALOGE("incompatible start and end UIDs (%u vs %u)", uidStart, uidEnd); 278 return -EUSERS; 279 } 280 bool isUidRule = (uidStart != INVALID_UID); 281 282 // Assemble a rule request and put it in an array of iovec structures. 283 fib_rule_hdr rule = { 284 .action = static_cast<uint8_t>(table != RT_TABLE_UNSPEC ? FR_ACT_TO_TBL : 285 FR_ACT_UNREACHABLE), 286 }; 287 288 rtattr fraIifName = { U16_RTA_LENGTH(iifLength), FRA_IIFNAME }; 289 rtattr fraOifName = { U16_RTA_LENGTH(oifLength), FRA_OIFNAME }; 290 291 iovec iov[] = { 292 { NULL, 0 }, 293 { &rule, sizeof(rule) }, 294 { &FRATTR_PRIORITY, sizeof(FRATTR_PRIORITY) }, 295 { &priority, sizeof(priority) }, 296 { &FRATTR_TABLE, table != RT_TABLE_UNSPEC ? sizeof(FRATTR_TABLE) : 0 }, 297 { &table, table != RT_TABLE_UNSPEC ? sizeof(table) : 0 }, 298 { &FRATTR_FWMARK, mask ? sizeof(FRATTR_FWMARK) : 0 }, 299 { &fwmark, mask ? sizeof(fwmark) : 0 }, 300 { &FRATTR_FWMASK, mask ? sizeof(FRATTR_FWMASK) : 0 }, 301 { &mask, mask ? sizeof(mask) : 0 }, 302 { &FRATTR_UID_START, isUidRule ? sizeof(FRATTR_UID_START) : 0 }, 303 { &uidStart, isUidRule ? sizeof(uidStart) : 0 }, 304 { &FRATTR_UID_END, isUidRule ? sizeof(FRATTR_UID_END) : 0 }, 305 { &uidEnd, isUidRule ? sizeof(uidEnd) : 0 }, 306 { &fraIifName, iif != IIF_NONE ? sizeof(fraIifName) : 0 }, 307 { iifName, iifLength }, 308 { PADDING_BUFFER, iifPadding }, 309 { &fraOifName, oif != OIF_NONE ? sizeof(fraOifName) : 0 }, 310 { oifName, oifLength }, 311 { PADDING_BUFFER, oifPadding }, 312 }; 313 314 uint16_t flags = (action == RTM_NEWRULE) ? NETLINK_CREATE_REQUEST_FLAGS : NETLINK_REQUEST_FLAGS; 315 for (size_t i = 0; i < ARRAY_SIZE(AF_FAMILIES); ++i) { 316 rule.family = AF_FAMILIES[i]; 317 if (int ret = sendNetlinkRequest(action, flags, iov, ARRAY_SIZE(iov))) { 318 return ret; 319 } 320 } 321 322 return 0; 323} 324 325WARN_UNUSED_RESULT int modifyIpRule(uint16_t action, uint32_t priority, uint32_t table, 326 uint32_t fwmark, uint32_t mask) { 327 return modifyIpRule(action, priority, table, fwmark, mask, IIF_NONE, OIF_NONE, INVALID_UID, 328 INVALID_UID); 329} 330 331// Adds or deletes an IPv4 or IPv6 route. 332// Returns 0 on success or negative errno on failure. 333WARN_UNUSED_RESULT int modifyIpRoute(uint16_t action, uint32_t table, const char* interface, 334 const char* destination, const char* nexthop) { 335 // At least the destination must be non-null. 336 if (!destination) { 337 ALOGE("null destination"); 338 return -EFAULT; 339 } 340 341 // Parse the prefix. 342 uint8_t rawAddress[sizeof(in6_addr)]; 343 uint8_t family; 344 uint8_t prefixLength; 345 int rawLength = parsePrefix(destination, &family, rawAddress, sizeof(rawAddress), 346 &prefixLength); 347 if (rawLength < 0) { 348 ALOGE("parsePrefix failed for destination %s (%s)", destination, strerror(-rawLength)); 349 return rawLength; 350 } 351 352 if (static_cast<size_t>(rawLength) > sizeof(rawAddress)) { 353 ALOGE("impossible! address too long (%d vs %zu)", rawLength, sizeof(rawAddress)); 354 return -ENOBUFS; // Cannot happen; parsePrefix only supports IPv4 and IPv6. 355 } 356 357 // If an interface was specified, find the ifindex. 358 uint32_t ifindex; 359 if (interface != OIF_NONE) { 360 ifindex = if_nametoindex(interface); 361 if (!ifindex) { 362 ALOGE("cannot find interface %s", interface); 363 return -ENODEV; 364 } 365 } 366 367 // If a nexthop was specified, parse it as the same family as the prefix. 368 uint8_t rawNexthop[sizeof(in6_addr)]; 369 if (nexthop && inet_pton(family, nexthop, rawNexthop) <= 0) { 370 ALOGE("inet_pton failed for nexthop %s", nexthop); 371 return -EINVAL; 372 } 373 374 // Assemble a rtmsg and put it in an array of iovec structures. 375 rtmsg route = { 376 .rtm_protocol = RTPROT_STATIC, 377 .rtm_type = RTN_UNICAST, 378 .rtm_family = family, 379 .rtm_dst_len = prefixLength, 380 }; 381 382 rtattr rtaDst = { U16_RTA_LENGTH(rawLength), RTA_DST }; 383 rtattr rtaGateway = { U16_RTA_LENGTH(rawLength), RTA_GATEWAY }; 384 385 iovec iov[] = { 386 { NULL, 0 }, 387 { &route, sizeof(route) }, 388 { &RTATTR_TABLE, sizeof(RTATTR_TABLE) }, 389 { &table, sizeof(table) }, 390 { &rtaDst, sizeof(rtaDst) }, 391 { rawAddress, static_cast<size_t>(rawLength) }, 392 { &RTATTR_OIF, interface != OIF_NONE ? sizeof(RTATTR_OIF) : 0 }, 393 { &ifindex, interface != OIF_NONE ? sizeof(ifindex) : 0 }, 394 { &rtaGateway, nexthop ? sizeof(rtaGateway) : 0 }, 395 { rawNexthop, nexthop ? static_cast<size_t>(rawLength) : 0 }, 396 }; 397 398 uint16_t flags = (action == RTM_NEWROUTE) ? NETLINK_CREATE_REQUEST_FLAGS : 399 NETLINK_REQUEST_FLAGS; 400 return sendNetlinkRequest(action, flags, iov, ARRAY_SIZE(iov)); 401} 402 403// An iptables rule to mark incoming packets on a network with the netId of the network. 404// 405// This is so that the kernel can: 406// + Use the right fwmark for (and thus correctly route) replies (e.g.: TCP RST, ICMP errors, ping 407// replies, SYN-ACKs, etc). 408// + Mark sockets that accept connections from this interface so that the connection stays on the 409// same interface. 410WARN_UNUSED_RESULT int modifyIncomingPacketMark(unsigned netId, const char* interface, 411 Permission permission, bool add) { 412 Fwmark fwmark; 413 414 fwmark.netId = netId; 415 fwmark.explicitlySelected = true; 416 fwmark.protectedFromVpn = true; 417 fwmark.permission = permission; 418 419 char markString[UINT32_HEX_STRLEN]; 420 snprintf(markString, sizeof(markString), "0x%x", fwmark.intValue); 421 422 if (execIptables(V4V6, "-t", "mangle", add ? "-A" : "-D", "INPUT", "-i", interface, "-j", 423 "MARK", "--set-mark", markString, NULL)) { 424 ALOGE("failed to change iptables rule that sets incoming packet mark"); 425 return -EREMOTEIO; 426 } 427 428 return 0; 429} 430 431// A rule to route responses to the local network forwarded via the VPN. 432// 433// When a VPN is in effect, packets from the local network to upstream networks are forwarded into 434// the VPN's tunnel interface. When the VPN forwards the responses, they emerge out of the tunnel. 435WARN_UNUSED_RESULT int modifyVpnOutputToLocalRule(const char* vpnInterface, bool add) { 436 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_VPN_OUTPUT_TO_LOCAL, 437 ROUTE_TABLE_LOCAL_NETWORK, MARK_UNSET, MARK_UNSET, vpnInterface, OIF_NONE, 438 INVALID_UID, INVALID_UID); 439} 440 441// A rule to route all traffic from a given set of UIDs to go over the VPN. 442// 443// Notice that this rule doesn't use the netId. I.e., no matter what netId the user's socket may 444// have, if they are subject to this VPN, their traffic has to go through it. Allows the traffic to 445// bypass the VPN if the protectedFromVpn bit is set. 446WARN_UNUSED_RESULT int modifyVpnUidRangeRule(uint32_t table, uid_t uidStart, uid_t uidEnd, 447 bool secure, bool add) { 448 Fwmark fwmark; 449 Fwmark mask; 450 451 fwmark.protectedFromVpn = false; 452 mask.protectedFromVpn = true; 453 454 uint32_t priority; 455 456 if (secure) { 457 priority = RULE_PRIORITY_SECURE_VPN; 458 } else { 459 priority = RULE_PRIORITY_BYPASSABLE_VPN; 460 461 fwmark.explicitlySelected = false; 462 mask.explicitlySelected = true; 463 } 464 465 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, priority, table, fwmark.intValue, 466 mask.intValue, IIF_NONE, OIF_NONE, uidStart, uidEnd); 467} 468 469// A rule to allow system apps to send traffic over this VPN even if they are not part of the target 470// set of UIDs. 471// 472// This is needed for DnsProxyListener to correctly resolve a request for a user who is in the 473// target set, but where the DnsProxyListener itself is not. 474WARN_UNUSED_RESULT int modifyVpnSystemPermissionRule(unsigned netId, uint32_t table, bool secure, 475 bool add) { 476 Fwmark fwmark; 477 Fwmark mask; 478 479 fwmark.netId = netId; 480 mask.netId = FWMARK_NET_ID_MASK; 481 482 fwmark.permission = PERMISSION_SYSTEM; 483 mask.permission = PERMISSION_SYSTEM; 484 485 uint32_t priority = secure ? RULE_PRIORITY_SECURE_VPN : RULE_PRIORITY_BYPASSABLE_VPN; 486 487 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, priority, table, fwmark.intValue, 488 mask.intValue); 489} 490 491// A rule to route traffic based on an explicitly chosen network. 492// 493// Supports apps that use the multinetwork APIs to restrict their traffic to a network. 494// 495// Even though we check permissions at the time we set a netId into the fwmark of a socket, we need 496// to check it again in the rules here, because a network's permissions may have been updated via 497// modifyNetworkPermission(). 498WARN_UNUSED_RESULT int modifyExplicitNetworkRule(unsigned netId, uint32_t table, 499 Permission permission, uid_t uidStart, 500 uid_t uidEnd, bool add) { 501 Fwmark fwmark; 502 Fwmark mask; 503 504 fwmark.netId = netId; 505 mask.netId = FWMARK_NET_ID_MASK; 506 507 fwmark.explicitlySelected = true; 508 mask.explicitlySelected = true; 509 510 fwmark.permission = permission; 511 mask.permission = permission; 512 513 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_EXPLICIT_NETWORK, table, 514 fwmark.intValue, mask.intValue, IIF_NONE, OIF_NONE, uidStart, uidEnd); 515} 516 517// A rule to route traffic based on a chosen outgoing interface. 518// 519// Supports apps that use SO_BINDTODEVICE or IP_PKTINFO options and the kernel that already knows 520// the outgoing interface (typically for link-local communications). 521WARN_UNUSED_RESULT int modifyOutputInterfaceRule(const char* interface, uint32_t table, 522 Permission permission, uid_t uidStart, 523 uid_t uidEnd, bool add) { 524 Fwmark fwmark; 525 Fwmark mask; 526 527 fwmark.permission = permission; 528 mask.permission = permission; 529 530 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_OUTPUT_INTERFACE, table, 531 fwmark.intValue, mask.intValue, IIF_NONE, interface, uidStart, uidEnd); 532} 533 534// A rule to route traffic based on the chosen network. 535// 536// This is for sockets that have not explicitly requested a particular network, but have been 537// bound to one when they called connect(). This ensures that sockets connected on a particular 538// network stay on that network even if the default network changes. 539WARN_UNUSED_RESULT int modifyImplicitNetworkRule(unsigned netId, uint32_t table, 540 Permission permission, bool add) { 541 Fwmark fwmark; 542 Fwmark mask; 543 544 fwmark.netId = netId; 545 mask.netId = FWMARK_NET_ID_MASK; 546 547 fwmark.explicitlySelected = false; 548 mask.explicitlySelected = true; 549 550 fwmark.permission = permission; 551 mask.permission = permission; 552 553 return modifyIpRule(add ? RTM_NEWRULE : RTM_DELRULE, RULE_PRIORITY_IMPLICIT_NETWORK, table, 554 fwmark.intValue, mask.intValue); 555} 556 557// Add rules to allow legacy routes added through the requestRouteToHost() API. 558WARN_UNUSED_RESULT int addLegacyRouteRules() { 559 Fwmark fwmark; 560 Fwmark mask; 561 562 fwmark.explicitlySelected = false; 563 mask.explicitlySelected = true; 564 565 // Rules to allow legacy routes to override the default network. 566 if (int ret = modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LEGACY_SYSTEM, ROUTE_TABLE_LEGACY_SYSTEM, 567 fwmark.intValue, mask.intValue)) { 568 return ret; 569 } 570 if (int ret = modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LEGACY_NETWORK, 571 ROUTE_TABLE_LEGACY_NETWORK, fwmark.intValue, mask.intValue)) { 572 return ret; 573 } 574 575 fwmark.permission = PERMISSION_SYSTEM; 576 mask.permission = PERMISSION_SYSTEM; 577 578 // A rule to allow legacy routes from system apps to override VPNs. 579 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_VPN_OVERRIDE_SYSTEM, ROUTE_TABLE_LEGACY_SYSTEM, 580 fwmark.intValue, mask.intValue); 581} 582 583// Add rules to lookup the local network when specified explicitly or otherwise. 584WARN_UNUSED_RESULT int addLocalNetworkRules(unsigned localNetId) { 585 if (int ret = modifyExplicitNetworkRule(localNetId, ROUTE_TABLE_LOCAL_NETWORK, PERMISSION_NONE, 586 INVALID_UID, INVALID_UID, ACTION_ADD)) { 587 return ret; 588 } 589 590 Fwmark fwmark; 591 Fwmark mask; 592 593 fwmark.explicitlySelected = false; 594 mask.explicitlySelected = true; 595 596 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_LOCAL_NETWORK, ROUTE_TABLE_LOCAL_NETWORK, 597 fwmark.intValue, mask.intValue); 598} 599 600// Add a new rule to look up the 'main' table, with the same selectors as the "default network" 601// rule, but with a lower priority. Since the default network rule points to a table with a default 602// route, the rule we're adding will never be used for normal routing lookups. However, the kernel 603// may fall-through to it to find directly-connected routes when it validates that a nexthop (in a 604// route being added) is reachable. 605WARN_UNUSED_RESULT int addDirectlyConnectedRule() { 606 Fwmark fwmark; 607 Fwmark mask; 608 609 fwmark.netId = NETID_UNSET; 610 mask.netId = FWMARK_NET_ID_MASK; 611 612 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_DIRECTLY_CONNECTED, RT_TABLE_MAIN, 613 fwmark.intValue, mask.intValue, IIF_NONE, OIF_NONE, UID_ROOT, UID_ROOT); 614} 615 616// Add a rule to preempt the pre-defined "from all lookup main" rule. Packets that reach this rule 617// will be null-routed, and won't fall-through to the main table. 618WARN_UNUSED_RESULT int addUnreachableRule() { 619 return modifyIpRule(RTM_NEWRULE, RULE_PRIORITY_UNREACHABLE, RT_TABLE_UNSPEC, MARK_UNSET, 620 MARK_UNSET); 621} 622 623WARN_UNUSED_RESULT int modifyLocalNetwork(unsigned netId, const char* interface, bool add) { 624 if (int ret = modifyIncomingPacketMark(netId, interface, PERMISSION_NONE, add)) { 625 return ret; 626 } 627 return modifyOutputInterfaceRule(interface, ROUTE_TABLE_LOCAL_NETWORK, PERMISSION_NONE, 628 INVALID_UID, INVALID_UID, add); 629} 630 631WARN_UNUSED_RESULT int modifyPhysicalNetwork(unsigned netId, const char* interface, 632 Permission permission, bool add) { 633 uint32_t table = getRouteTableForInterface(interface); 634 if (table == RT_TABLE_UNSPEC) { 635 return -ESRCH; 636 } 637 638 if (int ret = modifyIncomingPacketMark(netId, interface, permission, add)) { 639 return ret; 640 } 641 if (int ret = modifyExplicitNetworkRule(netId, table, permission, INVALID_UID, INVALID_UID, 642 add)) { 643 return ret; 644 } 645 if (int ret = modifyOutputInterfaceRule(interface, table, permission, INVALID_UID, INVALID_UID, 646 add)) { 647 return ret; 648 } 649 return modifyImplicitNetworkRule(netId, table, permission, add); 650} 651 652WARN_UNUSED_RESULT int modifyVirtualNetwork(unsigned netId, const char* interface, 653 const UidRanges& uidRanges, bool secure, bool add, 654 bool modifyNonUidBasedRules) { 655 uint32_t table = getRouteTableForInterface(interface); 656 if (table == RT_TABLE_UNSPEC) { 657 return -ESRCH; 658 } 659 660 for (const UidRanges::Range& range : uidRanges.getRanges()) { 661 if (int ret = modifyVpnUidRangeRule(table, range.first, range.second, secure, add)) { 662 return ret; 663 } 664 if (int ret = modifyExplicitNetworkRule(netId, table, PERMISSION_NONE, range.first, 665 range.second, add)) { 666 return ret; 667 } 668 if (int ret = modifyOutputInterfaceRule(interface, table, PERMISSION_NONE, range.first, 669 range.second, add)) { 670 return ret; 671 } 672 } 673 674 if (modifyNonUidBasedRules) { 675 if (int ret = modifyIncomingPacketMark(netId, interface, PERMISSION_NONE, add)) { 676 return ret; 677 } 678 if (int ret = modifyVpnOutputToLocalRule(interface, add)) { 679 return ret; 680 } 681 if (int ret = modifyVpnSystemPermissionRule(netId, table, secure, add)) { 682 return ret; 683 } 684 return modifyExplicitNetworkRule(netId, table, PERMISSION_NONE, UID_ROOT, UID_ROOT, add); 685 } 686 687 return 0; 688} 689 690WARN_UNUSED_RESULT int modifyDefaultNetwork(uint16_t action, const char* interface, 691 Permission permission) { 692 uint32_t table = getRouteTableForInterface(interface); 693 if (table == RT_TABLE_UNSPEC) { 694 return -ESRCH; 695 } 696 697 Fwmark fwmark; 698 Fwmark mask; 699 700 fwmark.netId = NETID_UNSET; 701 mask.netId = FWMARK_NET_ID_MASK; 702 703 fwmark.permission = permission; 704 mask.permission = permission; 705 706 return modifyIpRule(action, RULE_PRIORITY_DEFAULT_NETWORK, table, fwmark.intValue, 707 mask.intValue); 708} 709 710WARN_UNUSED_RESULT int modifyTetheredNetwork(uint16_t action, const char* inputInterface, 711 const char* outputInterface) { 712 uint32_t table = getRouteTableForInterface(outputInterface); 713 if (table == RT_TABLE_UNSPEC) { 714 return -ESRCH; 715 } 716 717 return modifyIpRule(action, RULE_PRIORITY_TETHERING, table, MARK_UNSET, MARK_UNSET, 718 inputInterface, OIF_NONE, INVALID_UID, INVALID_UID); 719} 720 721// Returns 0 on success or negative errno on failure. 722WARN_UNUSED_RESULT int flushRules() { 723 for (size_t i = 0; i < ARRAY_SIZE(IP_VERSIONS); ++i) { 724 const char* argv[] = { 725 IP_PATH, 726 IP_VERSIONS[i], 727 "rule", 728 "flush", 729 }; 730 if (android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, false, false)) { 731 ALOGE("failed to flush rules"); 732 return -EREMOTEIO; 733 } 734 } 735 return 0; 736} 737 738// Adds or removes an IPv4 or IPv6 route to the specified table and, if it's a directly-connected 739// route, to the main table as well. 740// Returns 0 on success or negative errno on failure. 741WARN_UNUSED_RESULT int modifyRoute(uint16_t action, const char* interface, const char* destination, 742 const char* nexthop, RouteController::TableType tableType) { 743 uint32_t table; 744 switch (tableType) { 745 case RouteController::INTERFACE: { 746 table = getRouteTableForInterface(interface); 747 if (table == RT_TABLE_UNSPEC) { 748 return -ESRCH; 749 } 750 break; 751 } 752 case RouteController::LOCAL_NETWORK: { 753 table = ROUTE_TABLE_LOCAL_NETWORK; 754 break; 755 } 756 case RouteController::LEGACY_NETWORK: { 757 table = ROUTE_TABLE_LEGACY_NETWORK; 758 break; 759 } 760 case RouteController::LEGACY_SYSTEM: { 761 table = ROUTE_TABLE_LEGACY_SYSTEM; 762 break; 763 } 764 } 765 766 int ret = modifyIpRoute(action, table, interface, destination, nexthop); 767 // We allow apps to call requestRouteToHost() multiple times with the same route, so ignore 768 // EEXIST failures when adding routes to legacy tables. 769 if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST && 770 (tableType == RouteController::LEGACY_NETWORK || 771 tableType == RouteController::LEGACY_SYSTEM))) { 772 return ret; 773 } 774 775 // If there's no nexthop, this is a directly connected route. Add it to the main table also, to 776 // let the kernel find it when validating nexthops when global routes are added. 777 if (!nexthop) { 778 ret = modifyIpRoute(action, RT_TABLE_MAIN, interface, destination, NULL); 779 // A failure with action == ADD && errno == EEXIST means that the route already exists in 780 // the main table, perhaps because the kernel added it automatically as part of adding the 781 // IP address to the interface. Ignore this, but complain about everything else. 782 if (ret && !(action == RTM_NEWROUTE && ret == -EEXIST)) { 783 return ret; 784 } 785 } 786 787 return 0; 788} 789 790// Returns 0 on success or negative errno on failure. 791WARN_UNUSED_RESULT int flushRoutes(const char* interface) { 792 uint32_t table = getRouteTableForInterface(interface); 793 if (table == RT_TABLE_UNSPEC) { 794 return -ESRCH; 795 } 796 797 char tableString[UINT32_STRLEN]; 798 snprintf(tableString, sizeof(tableString), "%u", table); 799 800 for (size_t i = 0; i < ARRAY_SIZE(IP_VERSIONS); ++i) { 801 const char* argv[] = { 802 IP_PATH, 803 IP_VERSIONS[i], 804 "route", 805 "flush", 806 "table", 807 tableString, 808 }; 809 if (android_fork_execvp(ARRAY_SIZE(argv), const_cast<char**>(argv), NULL, false, false)) { 810 ALOGE("failed to flush routes"); 811 return -EREMOTEIO; 812 } 813 } 814 815 interfaceToTable.erase(interface); 816 return 0; 817} 818 819} // namespace 820 821int RouteController::Init(unsigned localNetId) { 822 if (int ret = flushRules()) { 823 return ret; 824 } 825 if (int ret = addLegacyRouteRules()) { 826 return ret; 827 } 828 if (int ret = addLocalNetworkRules(localNetId)) { 829 return ret; 830 } 831 if (int ret = addDirectlyConnectedRule()) { 832 return ret; 833 } 834 if (int ret = addUnreachableRule()) { 835 return ret; 836 } 837 updateTableNamesFile(); 838 return 0; 839} 840 841int RouteController::addInterfaceToLocalNetwork(unsigned netId, const char* interface) { 842 return modifyLocalNetwork(netId, interface, ACTION_ADD); 843} 844 845int RouteController::removeInterfaceFromLocalNetwork(unsigned netId, const char* interface) { 846 return modifyLocalNetwork(netId, interface, ACTION_DEL); 847} 848 849int RouteController::addInterfaceToPhysicalNetwork(unsigned netId, const char* interface, 850 Permission permission) { 851 if (int ret = modifyPhysicalNetwork(netId, interface, permission, ACTION_ADD)) { 852 return ret; 853 } 854 updateTableNamesFile(); 855 return 0; 856} 857 858int RouteController::removeInterfaceFromPhysicalNetwork(unsigned netId, const char* interface, 859 Permission permission) { 860 if (int ret = modifyPhysicalNetwork(netId, interface, permission, ACTION_DEL)) { 861 return ret; 862 } 863 if (int ret = flushRoutes(interface)) { 864 return ret; 865 } 866 updateTableNamesFile(); 867 return 0; 868} 869 870int RouteController::addInterfaceToVirtualNetwork(unsigned netId, const char* interface, 871 bool secure, const UidRanges& uidRanges) { 872 if (int ret = modifyVirtualNetwork(netId, interface, uidRanges, secure, ACTION_ADD, 873 MODIFY_NON_UID_BASED_RULES)) { 874 return ret; 875 } 876 updateTableNamesFile(); 877 return 0; 878} 879 880int RouteController::removeInterfaceFromVirtualNetwork(unsigned netId, const char* interface, 881 bool secure, const UidRanges& uidRanges) { 882 if (int ret = modifyVirtualNetwork(netId, interface, uidRanges, secure, ACTION_DEL, 883 MODIFY_NON_UID_BASED_RULES)) { 884 return ret; 885 } 886 if (int ret = flushRoutes(interface)) { 887 return ret; 888 } 889 updateTableNamesFile(); 890 return 0; 891} 892 893int RouteController::modifyPhysicalNetworkPermission(unsigned netId, const char* interface, 894 Permission oldPermission, 895 Permission newPermission) { 896 // Add the new rules before deleting the old ones, to avoid race conditions. 897 if (int ret = modifyPhysicalNetwork(netId, interface, newPermission, ACTION_ADD)) { 898 return ret; 899 } 900 return modifyPhysicalNetwork(netId, interface, oldPermission, ACTION_DEL); 901} 902 903int RouteController::addUsersToVirtualNetwork(unsigned netId, const char* interface, bool secure, 904 const UidRanges& uidRanges) { 905 return modifyVirtualNetwork(netId, interface, uidRanges, secure, ACTION_ADD, 906 !MODIFY_NON_UID_BASED_RULES); 907} 908 909int RouteController::removeUsersFromVirtualNetwork(unsigned netId, const char* interface, 910 bool secure, const UidRanges& uidRanges) { 911 return modifyVirtualNetwork(netId, interface, uidRanges, secure, ACTION_DEL, 912 !MODIFY_NON_UID_BASED_RULES); 913} 914 915int RouteController::addInterfaceToDefaultNetwork(const char* interface, Permission permission) { 916 return modifyDefaultNetwork(RTM_NEWRULE, interface, permission); 917} 918 919int RouteController::removeInterfaceFromDefaultNetwork(const char* interface, 920 Permission permission) { 921 return modifyDefaultNetwork(RTM_DELRULE, interface, permission); 922} 923 924int RouteController::addRoute(const char* interface, const char* destination, const char* nexthop, 925 TableType tableType) { 926 return modifyRoute(RTM_NEWROUTE, interface, destination, nexthop, tableType); 927} 928 929int RouteController::removeRoute(const char* interface, const char* destination, 930 const char* nexthop, TableType tableType) { 931 return modifyRoute(RTM_DELROUTE, interface, destination, nexthop, tableType); 932} 933 934int RouteController::enableTethering(const char* inputInterface, const char* outputInterface) { 935 return modifyTetheredNetwork(RTM_NEWRULE, inputInterface, outputInterface); 936} 937 938int RouteController::disableTethering(const char* inputInterface, const char* outputInterface) { 939 return modifyTetheredNetwork(RTM_DELRULE, inputInterface, outputInterface); 940} 941