Memory_Linux.cpp

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00001 /* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
00002  * vim:expandtab:autoindent:tabstop=4:shiftwidth=4:filetype=c:cindent:textwidth=0:
00003  *
00004  * Copyright (C) 2005 Dell Inc.
00005  *  by Michael Brown <Michael_E_Brown@dell.com>
00006  * Licensed under the Open Software License version 2.1
00007  *
00008  * Alternatively, you can redistribute it and/or modify
00009  * it under the terms of the GNU General Public License as published
00010  * by the Free Software Foundation; either version 2 of the License,
00011  * or (at your option) any later version.
00012 
00013  * This program is distributed in the hope that it will be useful, but
00014  * WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
00016  * See the GNU General Public License for more details.
00017  */
00018 
00019 // compat header should always be first header if including system headers
00020 #define LIBSMBIOS_SOURCE
00021 #include "smbios/compat.h"
00022 
00023 #include <errno.h>
00024 #include <sys/mman.h>   /* mmap */
00025 #include <unistd.h>     /* getpagesize */
00026 
00027 #include "MemoryImpl.h"
00028 
00029 // include this last
00030 #include "smbios/message.h"
00031 
00032 using namespace std;
00033 using namespace factory;
00034 
00035 namespace memory
00036 {
00037     struct LinuxData
00038     {
00039         FILE *fd;
00040         void *lastMapping;
00041         unsigned long lastMappedOffset;
00042         unsigned long mappingSize;
00043         int reopenHint;
00044         string filename;
00045     };
00046 
00047     static void condOpenFd(struct LinuxData *data)
00048     {
00049         if(!data->fd)
00050         {
00051             data->lastMapping = 0;
00052             data->lastMappedOffset = 0;
00053             data->fd = fopen( data->filename.c_str(), "rb" );
00054             if(!data->fd)
00055             {
00056                 AccessErrorImpl accessError;
00057                 accessError.setMessageString( _("Unable to open memory. File: %(file)s, OS Error: %(err)s") );
00058                 accessError.setParameter( "file", data->filename );
00059                 accessError.setParameter( "err", strerror(errno) );
00060                 throw accessError;
00061             }
00062         }
00063     }
00064 
00065     static void closeFd(struct LinuxData *data)
00066     {
00067         if(data->lastMapping)
00068         {
00069             munmap(data->lastMapping, data->mappingSize);
00070             data->lastMapping = 0;
00071         }
00072         if (data->fd)
00073         {
00074             fclose(data->fd);
00075             data->fd = 0;
00076         }
00077         data->lastMappedOffset = 0;
00078     }
00079 
00080     MemoryFactoryImpl::MemoryFactoryImpl()
00081     {
00082         setParameter("memFile", "/dev/mem");
00083     }
00084 
00085     MemoryOsSpecific::MemoryOsSpecific( const string filename )
00086             : IMemory()
00087     {
00088         LinuxData *data = new LinuxData();
00089         data->fd = 0;
00090         data->filename = filename;
00091         data->mappingSize = getpagesize() * 16;
00092         data->reopenHint = 1;
00093         condOpenFd(data);
00094         closeFd(data);
00095         osData = static_cast<void *>(data);
00096     }
00097 
00098     MemoryOsSpecific::~MemoryOsSpecific()
00099     {
00100         LinuxData *data = static_cast<LinuxData *>(osData);
00101         closeFd(data);
00102         delete data;
00103         osData = 0;
00104     }
00105 
00106     int MemoryOsSpecific::incReopenHint()
00107     {
00108         LinuxData *data = static_cast<LinuxData *>(osData);
00109         return ++(data->reopenHint);
00110     }
00111     int MemoryOsSpecific::decReopenHint()
00112     {
00113         LinuxData *data = static_cast<LinuxData *>(osData);
00114         return --(data->reopenHint);
00115     }
00116 
00117     void MemoryOsSpecific::fillBuffer( u8 *buffer, u64 offset, unsigned int length) const
00118     {
00119         LinuxData *data = static_cast<LinuxData *>(osData);
00120         unsigned int bytesCopied = 0;
00121 
00122         condOpenFd(data);
00123 
00124         while( bytesCopied < length )
00125         {
00126             off_t mmoff = offset % data->mappingSize;
00127 
00128             if ((offset-mmoff) != data->lastMappedOffset)
00129             {
00130                 data->lastMappedOffset = offset-mmoff;
00131                 if (data->lastMapping)
00132                     munmap(data->lastMapping, data->mappingSize);
00133                 data->lastMapping = mmap( 0, data->mappingSize, PROT_READ, MAP_PRIVATE, fileno(data->fd), offset-mmoff);
00134                 if ((data->lastMapping) == reinterpret_cast<void *>(-1))
00135                     throw AccessErrorImpl(_("mmap failed."));
00136             }
00137 
00138             unsigned long toCopy = length - bytesCopied;
00139             if( toCopy + mmoff > (data->mappingSize) )
00140                 toCopy = (data->mappingSize) - mmoff;
00141 
00142             memcpy(buffer + bytesCopied, (reinterpret_cast<const u8 *>(data->lastMapping) + mmoff), toCopy);
00143             offset += toCopy;
00144             bytesCopied += toCopy;
00145         }
00146 
00147         if(data->reopenHint)
00148             closeFd(data);
00149 
00150     }
00151 
00152     u8 MemoryOsSpecific::getByte( u64 offset ) const
00153     {
00154         u8 value=0;
00155         fillBuffer( &value, offset, 1 );
00156         return value;
00157     }
00158 
00159     void MemoryOsSpecific::putByte( u64 offset, u8 value ) const
00160     {
00161         LinuxData *data = static_cast<LinuxData *>(osData);
00162         condOpenFd(data);
00163         int ret = fseek( data->fd, offset, 0 );
00164         if( 0 != ret )
00165         {
00166             OutOfBoundsImpl outOfBounds;
00167             outOfBounds.setMessageString(_("Seek error trying to seek to memory location. OS Error: %(err)s"));
00168             outOfBounds.setParameter("err", strerror(errno) );
00169             closeFd(data);
00170             throw outOfBounds;
00171         }
00172         ret = fwrite( &value, 1, 1, data->fd );
00173         if( 1 != ret )
00174         {
00175             AccessErrorImpl accessError;
00176             accessError.setMessageString(_("Error trying to write memory. OS Error: %(err)s"));
00177             accessError.setParameter("err", strerror(errno) );
00178             closeFd(data);
00179             throw accessError;
00180         }
00181         if(data->reopenHint)
00182             closeFd(data);
00183     }
00184 
00185 }

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