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Commit 1114f180 authored by Mark Salyzyn's avatar Mark Salyzyn
Browse files

logd: institute getGroups for socket credentials 

(cherry pick from commit 4d851290fc81eb36d2fcf76e6f06213a28b877f5)

Change-Id: Ib8be84d2a3f873e91fb1495df439a498f395c137
parent 0577a067

logd/CommandListener.cpp

+7 −9
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012-2013 The Android Open Source Project

 * Copyright (C) 2012-2014 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.
@@ -24,10 +24,11 @@ 
#include <sys/socket.h>

#include <sys/types.h>



#include <sysutils/SocketClient.h>

#include <private/android_filesystem_config.h>

#include <sysutils/SocketClient.h>



#include "CommandListener.h"

#include "LogCommand.h"



CommandListener::CommandListener(LogBuffer *buf, LogReader * /*reader*/,

                                 LogListener * /*swl*/)
@@ -62,9 +63,7 @@ CommandListener::ClearCmd::ClearCmd(LogBuffer *buf) 


int CommandListener::ClearCmd::runCommand(SocketClient *cli,

                                         int argc, char **argv) {

    if ((cli->getUid() != AID_ROOT)

            && (cli->getGid() != AID_ROOT)

            && (cli->getGid() != AID_LOG)) {

    if (!clientHasLogCredentials(cli)) {

        cli->sendMsg("Permission Denied");

        return 0;

    }
@@ -75,7 +74,7 @@ int CommandListener::ClearCmd::runCommand(SocketClient *cli, 
    }



    int id = atoi(argv[1]);

    if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {

    if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {

        cli->sendMsg("Range Error");

        return 0;

    }
@@ -85,7 +84,6 @@ int CommandListener::ClearCmd::runCommand(SocketClient *cli, 
    return 0;

}





CommandListener::GetBufSizeCmd::GetBufSizeCmd(LogBuffer *buf)

        : LogCommand("getLogSize")

        , mBuf(*buf)
@@ -99,7 +97,7 @@ int CommandListener::GetBufSizeCmd::runCommand(SocketClient *cli, 
    }



    int id = atoi(argv[1]);

    if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {

    if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {

        cli->sendMsg("Range Error");

        return 0;

    }
@@ -124,7 +122,7 @@ int CommandListener::GetBufSizeUsedCmd::runCommand(SocketClient *cli, 
    }



    int id = atoi(argv[1]);

    if ((id < LOG_ID_MIN) || (id >= LOG_ID_MAX)) {

    if ((id < LOG_ID_MIN) || (LOG_ID_MAX <= id)) {

        cli->sendMsg("Range Error");

        return 0;

    }

logd/FlushCommand.cpp

+5 −6
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012-2013 The Android Open Source Project

 * Copyright (C) 2012-2014 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.
@@ -15,11 +15,12 @@ 
 */



#include <stdlib.h>

#include <private/android_filesystem_config.h>



#include "FlushCommand.h"

#include "LogBufferElement.h"

#include "LogTimes.h"

#include "LogCommand.h"

#include "LogReader.h"

#include "LogTimes.h"



FlushCommand::FlushCommand(LogReader &reader,

                           bool nonBlock,
@@ -80,7 +81,5 @@ void FlushCommand::runSocketCommand(SocketClient *client) { 
}



bool FlushCommand::hasReadLogs(SocketClient *client) {

    return (client->getUid() == AID_ROOT)

            || (client->getGid() == AID_ROOT)

            || (client->getGid() == AID_LOG);

    return clientHasLogCredentials(client);

}

logd/LogCommand.cpp

+110 −1
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012-2013 The Android Open Source Project

 * Copyright (C) 2012-2014 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.
@@ -14,8 +14,117 @@ 
 * limitations under the License.

 */



#include <errno.h>

#include <stdio.h>

#include <stdlib.h>



#include <private/android_filesystem_config.h>



#include "LogCommand.h"



LogCommand::LogCommand(const char *cmd)

        : FrameworkCommand(cmd) {

}



// gets a list of supplementary group IDs associated with

// the socket peer.  This is implemented by opening

// /proc/PID/status and look for the "Group:" line.

//

// This function introduces races especially since status

// can change 'shape' while reading, the net result is err

// on lack of permission.

//

// Race-free alternative is to introduce pairs of sockets

// and threads for each command and reading, one each that

// has open permissions, and one that has restricted

// permissions.



static bool groupIsLog(char *buf) {

    char *ptr;

    static const char ws[] = " \n";

    bool ret = false;



    for (buf = strtok_r(buf, ws, &ptr); buf; buf = strtok_r(NULL, ws, &ptr)) {

        errno = 0;

        gid_t Gid = strtol(buf, NULL, 10);

        if (errno != 0) {

            return false;

        }

        if (Gid == AID_LOG) {

            ret = true;

        }

    }

    return ret;

}



bool clientHasLogCredentials(SocketClient * cli) {

    uid_t uid = cli->getUid();

    if (uid == AID_ROOT) {

        return true;

    }



    gid_t gid = cli->getGid();

    if ((gid == AID_ROOT) || (gid == AID_LOG)) {

        return true;

    }



    // FYI We will typically be here for 'adb logcat'

    bool ret = false;



    char filename[1024];

    snprintf(filename, sizeof(filename), "/proc/%d/status", cli->getPid());



    FILE *file = fopen(filename, "r");

    if (!file) {

        return ret;

    }



    bool foundGid = false;

    bool foundUid = false;



    char line[1024];

    while (fgets(line, sizeof(line), file)) {

        static const char groups_string[] = "Groups:\t";

        static const char uid_string[] = "Uid:\t";

        static const char gid_string[] = "Gid:\t";



        if (strncmp(groups_string, line, strlen(groups_string)) == 0) {

            ret = groupIsLog(line + strlen(groups_string));

            if (!ret) {

                break;

            }

        } else if (strncmp(uid_string, line, strlen(uid_string)) == 0) {

            uid_t u[4] = { (uid_t) -1, (uid_t) -1, (uid_t) -1, (uid_t) -1};



            sscanf(line + strlen(uid_string), "%u\t%u\t%u\t%u",

                   &u[0], &u[1], &u[2], &u[3]);



            // Protect against PID reuse by checking that the UID is the same

            if ((uid != u[0]) || (uid != u[1]) || (uid != u[2]) || (uid != u[3])) {

                ret = false;

                break;

            }

            foundUid = true;

        } else if (strncmp(gid_string, line, strlen(gid_string)) == 0) {

            gid_t g[4] = { (gid_t) -1, (gid_t) -1, (gid_t) -1, (gid_t) -1};



            sscanf(line + strlen(gid_string), "%u\t%u\t%u\t%u",

                   &g[0], &g[1], &g[2], &g[3]);



            // Protect against PID reuse by checking that the GID is the same

            if ((gid != g[0]) || (gid != g[1]) || (gid != g[2]) || (gid != g[3])) {

                ret = false;

                break;

            }

            foundGid = true;

        }

    }



    fclose(file);



    if (!foundGid || !foundUid) {

        ret = false;

    }



    return ret;

}

logd/LogCommand.h

+4 −1
Original line number Diff line number Diff line 
/*

 * Copyright (C) 2012-2013 The Android Open Source Project

 * Copyright (C) 2012-2014 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.
@@ -17,6 +17,7 @@ 
#ifndef _LOGD_COMMAND_H

#define _LOGD_COMMAND_H



#include <sysutils/SocketClient.h>

#include <sysutils/FrameworkCommand.h>



class LogCommand : public FrameworkCommand {
@@ -25,4 +26,6 @@ public: 
    virtual ~LogCommand() {}

};



bool clientHasLogCredentials(SocketClient * cli);



#endif