mountInfo.cpp

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/*
 * $Id: mountInfo.cpp 4 2015-12-04 13:55:56Z wejaeger $
 *
 * File:   mountInfo.cpp
 * Author: Werner Jaeger
 *
 * Created on November 28, 2015, 10:38 AM
 *
 * Copyright 2015 Werner Jaeger.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
#include <string.h>
#include "mountInfo.h"

MountInfo::Entry::Entry(const char* pcMountLine)
{
   parseMountInfo(pcMountLine);
}

bool MountInfo::Entry::isMountedRo() const
{
    return(m_mountOptions.find("ro") != m_mountOptions.cend());
}

bool MountInfo::Entry::isMountedNoexec() const
{
    return(m_mountOptions.find("noexec") != m_mountOptions.cend());
}

void MountInfo::Entry::parseMountInfo(const char* pcMountLine)
{
    if (pcMountLine)
    {
        const int iLen(::strlen(pcMountLine) + 1);

        char acTokens[iLen];
        ::strncpy(acTokens, pcMountLine, iLen);

        char* pcSave;
        char* pch = ::strtok_r(acTokens, " ", &pcSave);
        if (pch)
            m_strFileSystem = pch;

        pch = ::strtok_r(NULL, " ", &pcSave);
        if (pch && ::strcmp(pch, "on") == 0)
        {
            pch = ::strtok_r(NULL, " ", &pcSave);
            if (pch)
            {
                m_strMountPoint = pch;
                pch = ::strtok_r(NULL, " ", &pcSave);
                if (pch && ::strcmp(pch, "type") == 0)
                {
                    pch = ::strtok_r(NULL, " ", &pcSave);
                    if (pch)
                    {
                        m_strDevType = pch;
                        pch = ::strtok_r(NULL, "(", &pcSave);
                    }
                }
            }
        }

        if (pch)
        {
            pch = ::strtok_r(pch, ",)", &pcSave);
            while (pch != NULL)
            {
                m_mountOptions.insert(pch);
                pch = ::strtok_r(NULL, ",)", &pcSave);
            }
        }
    }
}

MountInfo::MountInfo(const deque<string>& mountInfo)
{
    for(auto it = mountInfo.begin(); it != mountInfo.end(); ++it)
    {
        Entry entry(it->c_str());
        m_Entries.insert(make_pair(entry.mountPoint(), entry));
    }
}

const MountInfo::Entry* MountInfo::mountPoint(const char* pcPath) const
{
    string strParent(pcPath);
    const Entry* pMountPointEntry(findMountPointEntry(strParent));

    while (!pMountPointEntry && strParent != "/")
    {
        strParent = parent(strParent);
        pMountPointEntry = findMountPointEntry(strParent);
    }

    return(pMountPointEntry);
}

bool MountInfo::isMountedRo(const char* pcPath) const
{
    const Entry* pEntry(mountPoint(pcPath));

    return(pEntry ? pEntry->isMountedRo() : false);
}

bool MountInfo::isMountedNoexec(const char* pcPath) const
{
    const MountInfo::Entry* pEntry(mountPoint(pcPath));

    return(pEntry ? pEntry->isMountedNoexec() : false);
}

const MountInfo::Entry* MountInfo::findMountPointEntry(const string& strPath) const
{
    const Entry* pMountPointEntry(NULL);

    for (auto it = m_Entries.begin(); !pMountPointEntry && it != m_Entries.end(); ++it)
    {
        if (it->first == strPath)
            pMountPointEntry = &it->second;
    }

    return(pMountPointEntry);
}

const string MountInfo::parent(const string& strPath)
{
    string strParent(strPath);
    const size_t uiLen(strParent.length());

    /* if strPath == / we are done*/
    if (uiLen != 1 || strParent[0] != '/')
    {
        if (uiLen > 0)
        {
            if (strParent[uiLen - 1] == '/')
                strParent = strParent.substr(0, uiLen - 1);

            const std::size_t uiPos(strParent.rfind('/'));
            if (uiPos != string::npos)
                strParent = strParent.substr(0, uiPos == 0 ? 1 : uiPos);

            if (strParent == strPath)
                strParent = ".";
        }
        else
            strParent = ".";
    }

    return(strParent);
}