Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2014 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 | |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 17 | #include "NetdClient.h" |
| 18 | |
Sreeram Ramachandran | 4d4c8b7 | 2014-06-20 11:59:40 -0700 | [diff] [blame^] | 19 | #include "Fwmark.h" |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 20 | #include "FwmarkClient.h" |
| 21 | #include "FwmarkCommand.h" |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 22 | #include "resolv_netid.h" |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 23 | |
Sreeram Ramachandran | 9fa2b13 | 2014-06-03 12:51:08 -0700 | [diff] [blame] | 24 | #include <atomic> |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 25 | #include <sys/socket.h> |
| 26 | #include <unistd.h> |
| 27 | |
| 28 | namespace { |
| 29 | |
Sreeram Ramachandran | 9fa2b13 | 2014-06-03 12:51:08 -0700 | [diff] [blame] | 30 | std::atomic_uint netIdForProcess(NETID_UNSET); |
| 31 | std::atomic_uint netIdForResolv(NETID_UNSET); |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 32 | |
| 33 | typedef int (*Accept4FunctionType)(int, sockaddr*, socklen_t*, int); |
| 34 | typedef int (*ConnectFunctionType)(int, const sockaddr*, socklen_t); |
| 35 | typedef int (*SocketFunctionType)(int, int, int); |
| 36 | typedef unsigned (*NetIdForResolvFunctionType)(unsigned); |
| 37 | |
| 38 | // These variables are only modified at startup (when libc.so is loaded) and never afterwards, so |
| 39 | // it's okay that they are read later at runtime without a lock. |
| 40 | Accept4FunctionType libcAccept4 = 0; |
| 41 | ConnectFunctionType libcConnect = 0; |
| 42 | SocketFunctionType libcSocket = 0; |
| 43 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 44 | int closeFdAndSetErrno(int fd, int error) { |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 45 | close(fd); |
| 46 | errno = error; |
| 47 | return -1; |
| 48 | } |
| 49 | |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 50 | int netdClientAccept4(int sockfd, sockaddr* addr, socklen_t* addrlen, int flags) { |
| 51 | int acceptedSocket = libcAccept4(sockfd, addr, addrlen, flags); |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 52 | if (acceptedSocket == -1) { |
| 53 | return -1; |
| 54 | } |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 55 | int family; |
| 56 | if (addr) { |
| 57 | family = addr->sa_family; |
| 58 | } else { |
| 59 | socklen_t familyLen = sizeof(family); |
| 60 | if (getsockopt(acceptedSocket, SOL_SOCKET, SO_DOMAIN, &family, &familyLen) == -1) { |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 61 | return closeFdAndSetErrno(acceptedSocket, errno); |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 62 | } |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 63 | } |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 64 | if (FwmarkClient::shouldSetFwmark(family)) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 65 | FwmarkCommand command = {FwmarkCommand::ON_ACCEPT, 0}; |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 66 | int error = FwmarkClient().send(&command, sizeof(command), acceptedSocket); |
| 67 | if (error) { |
| 68 | return closeFdAndSetErrno(acceptedSocket, error); |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 69 | } |
| 70 | } |
| 71 | return acceptedSocket; |
| 72 | } |
| 73 | |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 74 | int netdClientConnect(int sockfd, const sockaddr* addr, socklen_t addrlen) { |
| 75 | if (sockfd >= 0 && addr && FwmarkClient::shouldSetFwmark(addr->sa_family)) { |
| 76 | FwmarkCommand command = {FwmarkCommand::ON_CONNECT, 0}; |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 77 | int error = FwmarkClient().send(&command, sizeof(command), sockfd); |
| 78 | if (error) { |
| 79 | errno = error; |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 80 | return -1; |
| 81 | } |
| 82 | } |
| 83 | return libcConnect(sockfd, addr, addrlen); |
| 84 | } |
| 85 | |
| 86 | int netdClientSocket(int domain, int type, int protocol) { |
| 87 | int socketFd = libcSocket(domain, type, protocol); |
| 88 | if (socketFd == -1) { |
| 89 | return -1; |
| 90 | } |
| 91 | unsigned netId = netIdForProcess; |
| 92 | if (netId != NETID_UNSET && FwmarkClient::shouldSetFwmark(domain)) { |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 93 | int error = setNetworkForSocket(netId, socketFd); |
| 94 | if (error) { |
| 95 | return closeFdAndSetErrno(socketFd, error); |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 96 | } |
| 97 | } |
| 98 | return socketFd; |
| 99 | } |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 100 | |
| 101 | unsigned getNetworkForResolv(unsigned netId) { |
| 102 | if (netId != NETID_UNSET) { |
| 103 | return netId; |
| 104 | } |
| 105 | netId = netIdForProcess; |
| 106 | if (netId != NETID_UNSET) { |
| 107 | return netId; |
| 108 | } |
| 109 | return netIdForResolv; |
| 110 | } |
| 111 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 112 | int setNetworkForTarget(unsigned netId, std::atomic_uint* target) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 113 | if (netId == NETID_UNSET) { |
| 114 | *target = netId; |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 115 | return 0; |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 116 | } |
| 117 | // Verify that we are allowed to use |netId|, by creating a socket and trying to have it marked |
Sreeram Ramachandran | 2756045 | 2014-05-30 19:59:51 -0700 | [diff] [blame] | 118 | // with the netId. Call libcSocket() directly; else the socket creation (via netdClientSocket()) |
| 119 | // might itself cause another check with the fwmark server, which would be wasteful. |
| 120 | int socketFd; |
| 121 | if (libcSocket) { |
| 122 | socketFd = libcSocket(AF_INET6, SOCK_DGRAM, 0); |
| 123 | } else { |
| 124 | socketFd = socket(AF_INET6, SOCK_DGRAM, 0); |
| 125 | } |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 126 | if (socketFd < 0) { |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 127 | return errno; |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 128 | } |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 129 | int error = setNetworkForSocket(netId, socketFd); |
| 130 | if (!error) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 131 | *target = netId; |
| 132 | } |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 133 | close(socketFd); |
| 134 | return error; |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 135 | } |
| 136 | |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 137 | } // namespace |
| 138 | |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 139 | // accept() just calls accept4(..., 0), so there's no need to handle accept() separately. |
| 140 | extern "C" void netdClientInitAccept4(Accept4FunctionType* function) { |
| 141 | if (function && *function) { |
| 142 | libcAccept4 = *function; |
| 143 | *function = netdClientAccept4; |
| 144 | } |
| 145 | } |
| 146 | |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 147 | extern "C" void netdClientInitConnect(ConnectFunctionType* function) { |
| 148 | if (function && *function) { |
| 149 | libcConnect = *function; |
| 150 | *function = netdClientConnect; |
| 151 | } |
| 152 | } |
| 153 | |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 154 | extern "C" void netdClientInitSocket(SocketFunctionType* function) { |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 155 | if (function && *function) { |
Sreeram Ramachandran | 5fc2757 | 2014-05-21 13:08:34 -0700 | [diff] [blame] | 156 | libcSocket = *function; |
| 157 | *function = netdClientSocket; |
Sreeram Ramachandran | f4cfad3 | 2014-05-21 08:54:07 -0700 | [diff] [blame] | 158 | } |
| 159 | } |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 160 | |
| 161 | extern "C" void netdClientInitNetIdForResolv(NetIdForResolvFunctionType* function) { |
| 162 | if (function) { |
| 163 | *function = getNetworkForResolv; |
| 164 | } |
| 165 | } |
| 166 | |
Sreeram Ramachandran | 4d4c8b7 | 2014-06-20 11:59:40 -0700 | [diff] [blame^] | 167 | extern "C" int getNetworkForSocket(unsigned* netId, int socketFd) { |
| 168 | if (!netId || socketFd < 0) { |
| 169 | return EBADF; |
| 170 | } |
| 171 | Fwmark fwmark; |
| 172 | socklen_t fwmarkLen = sizeof(fwmark.intValue); |
| 173 | if (getsockopt(socketFd, SOL_SOCKET, SO_MARK, &fwmark.intValue, &fwmarkLen) == -1) { |
| 174 | return errno; |
| 175 | } |
| 176 | *netId = fwmark.netId; |
| 177 | return 0; |
| 178 | } |
| 179 | |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 180 | extern "C" unsigned getNetworkForProcess() { |
| 181 | return netIdForProcess; |
| 182 | } |
| 183 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 184 | extern "C" int setNetworkForSocket(unsigned netId, int socketFd) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 185 | if (socketFd < 0) { |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 186 | return EBADF; |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 187 | } |
| 188 | FwmarkCommand command = {FwmarkCommand::SELECT_NETWORK, netId}; |
| 189 | return FwmarkClient().send(&command, sizeof(command), socketFd); |
| 190 | } |
| 191 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 192 | extern "C" int setNetworkForProcess(unsigned netId) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 193 | return setNetworkForTarget(netId, &netIdForProcess); |
| 194 | } |
| 195 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 196 | extern "C" int setNetworkForResolv(unsigned netId) { |
Sreeram Ramachandran | efbe05d | 2014-05-21 11:41:39 -0700 | [diff] [blame] | 197 | return setNetworkForTarget(netId, &netIdForResolv); |
| 198 | } |
Sreeram Ramachandran | d794e58 | 2014-06-19 10:03:07 -0700 | [diff] [blame] | 199 | |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 200 | extern "C" int protectFromVpn(int socketFd) { |
Sreeram Ramachandran | d794e58 | 2014-06-19 10:03:07 -0700 | [diff] [blame] | 201 | if (socketFd < 0) { |
Sreeram Ramachandran | 31f4210 | 2014-06-20 11:51:48 -0700 | [diff] [blame] | 202 | return EBADF; |
Sreeram Ramachandran | d794e58 | 2014-06-19 10:03:07 -0700 | [diff] [blame] | 203 | } |
| 204 | FwmarkCommand command = {FwmarkCommand::PROTECT_FROM_VPN, 0}; |
| 205 | return FwmarkClient().send(&command, sizeof(command), socketFd); |
| 206 | } |