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 17 #include "FwmarkClient.h" 18 19 #include "FwmarkCommand.h" 20 21 #include <errno.h> 22 #include <stdlib.h> 23 #include <string.h> 24 #include <sys/socket.h> 25 #include <sys/un.h> 26 #include <unistd.h> 27 28 namespace { 29 30 const sockaddr_un FWMARK_SERVER_PATH = {AF_UNIX, "/dev/socket/fwmarkd"}; 31 32 } // namespace 33 34 bool FwmarkClient::shouldSetFwmark(int family) { 35 return (family == AF_INET || family == AF_INET6) && !getenv("ANDROID_NO_USE_FWMARK_CLIENT"); 36 } 37 38 FwmarkClient::FwmarkClient() : mChannel(-1) { 39 } 40 41 FwmarkClient::~FwmarkClient() { 42 if (mChannel >= 0) { 43 close(mChannel); 44 } 45 } 46 47 int FwmarkClient::send(FwmarkCommand* data, int fd) { 48 mChannel = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0); 49 if (mChannel == -1) { 50 return -errno; 51 } 52 53 if (TEMP_FAILURE_RETRY(connect(mChannel, reinterpret_cast<const sockaddr*>(&FWMARK_SERVER_PATH), 54 sizeof(FWMARK_SERVER_PATH))) == -1) { 55 // If we are unable to connect to the fwmark server, assume there's no error. This protects 56 // against future changes if the fwmark server goes away. 57 return 0; 58 } 59 60 iovec iov; 61 iov.iov_base = data; 62 iov.iov_len = sizeof(*data); 63 64 msghdr message; 65 memset(&message, 0, sizeof(message)); 66 message.msg_iov = &iov; 67 message.msg_iovlen = 1; 68 69 union { 70 cmsghdr cmh; 71 char cmsg[CMSG_SPACE(sizeof(fd))]; 72 } cmsgu; 73 74 if (data->cmdId != FwmarkCommand::QUERY_USER_ACCESS) { 75 memset(cmsgu.cmsg, 0, sizeof(cmsgu.cmsg)); 76 message.msg_control = cmsgu.cmsg; 77 message.msg_controllen = sizeof(cmsgu.cmsg); 78 79 cmsghdr* const cmsgh = CMSG_FIRSTHDR(&message); 80 cmsgh->cmsg_len = CMSG_LEN(sizeof(fd)); 81 cmsgh->cmsg_level = SOL_SOCKET; 82 cmsgh->cmsg_type = SCM_RIGHTS; 83 memcpy(CMSG_DATA(cmsgh), &fd, sizeof(fd)); 84 } 85 86 if (TEMP_FAILURE_RETRY(sendmsg(mChannel, &message, 0)) == -1) { 87 return -errno; 88 } 89 90 int error = 0; 91 92 if (TEMP_FAILURE_RETRY(recv(mChannel, &error, sizeof(error), 0)) == -1) { 93 return -errno; 94 } 95 96 return error; 97 } 98