Home | History | Annotate | Download | only in client 
      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 <cutils/properties.h>
     23 #include <stdlib.h>
     24 #include <string.h>
     25 #include <sys/socket.h>
     26 #include <sys/un.h>
     27 #include <unistd.h>
     28 
     29 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
     30 
     31 namespace {
     32 
     33 const sockaddr_un FWMARK_SERVER_PATH = {AF_UNIX, "/dev/socket/fwmarkd"};
     34 
     35 const bool isBuildDebuggable = property_get_bool("ro.debuggable", 0) == 1;
     36 
     37 bool isOverriddenBy(const char *name) {
     38     return isBuildDebuggable && getenv(name);
     39 }
     40 
     41 }  // namespace
     42 
     43 bool FwmarkClient::shouldSetFwmark(int family) {
     44     if (isOverriddenBy(ANDROID_NO_USE_FWMARK_CLIENT)) {
     45         return false;
     46     }
     47     return family == AF_INET || family == AF_INET6;
     48 }
     49 
     50 bool FwmarkClient::shouldReportConnectComplete(int family) {
     51     if (isOverriddenBy(ANDROID_FWMARK_METRICS_ONLY)) {
     52         return false;
     53     }
     54     return shouldSetFwmark(family);
     55 }
     56 
     57 FwmarkClient::FwmarkClient() : mChannel(-1) {
     58 }
     59 
     60 FwmarkClient::~FwmarkClient() {
     61     if (mChannel >= 0) {
     62         close(mChannel);
     63     }
     64 }
     65 
     66 int FwmarkClient::send(FwmarkCommand* data, int fd, FwmarkConnectInfo* connectInfo) {
     67     mChannel = socket(AF_UNIX, SOCK_STREAM | SOCK_CLOEXEC, 0);
     68     if (mChannel == -1) {
     69         return -errno;
     70     }
     71 
     72     if (TEMP_FAILURE_RETRY(connect(mChannel, reinterpret_cast<const sockaddr*>(&FWMARK_SERVER_PATH),
     73                                    sizeof(FWMARK_SERVER_PATH))) == -1) {
     74         // If we are unable to connect to the fwmark server, assume there's no error. This protects
     75         // against future changes if the fwmark server goes away.
     76         return 0;
     77     }
     78 
     79     iovec iov[2] = {
     80         { data, sizeof(*data) },
     81         { connectInfo, (connectInfo ? sizeof(*connectInfo) : 0) },
     82     };
     83     msghdr message;
     84     memset(&message, 0, sizeof(message));
     85     message.msg_iov = iov;
     86     message.msg_iovlen = ARRAY_SIZE(iov);
     87 
     88     union {
     89         cmsghdr cmh;
     90         char cmsg[CMSG_SPACE(sizeof(fd))];
     91     } cmsgu;
     92 
     93     if (data->cmdId != FwmarkCommand::QUERY_USER_ACCESS) {
     94         memset(cmsgu.cmsg, 0, sizeof(cmsgu.cmsg));
     95         message.msg_control = cmsgu.cmsg;
     96         message.msg_controllen = sizeof(cmsgu.cmsg);
     97 
     98         cmsghdr* const cmsgh = CMSG_FIRSTHDR(&message);
     99         cmsgh->cmsg_len = CMSG_LEN(sizeof(fd));
    100         cmsgh->cmsg_level = SOL_SOCKET;
    101         cmsgh->cmsg_type = SCM_RIGHTS;
    102         memcpy(CMSG_DATA(cmsgh), &fd, sizeof(fd));
    103     }
    104 
    105     if (TEMP_FAILURE_RETRY(sendmsg(mChannel, &message, 0)) == -1) {
    106         return -errno;
    107     }
    108 
    109     int error = 0;
    110 
    111     if (TEMP_FAILURE_RETRY(recv(mChannel, &error, sizeof(error), 0)) == -1) {
    112         return -errno;
    113     }
    114 
    115     return error;
    116 }
    117