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affrecover.cpp
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affrecover.cpp
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/*
* afrecover.cpp
*
* Recover broken pages of an AFF file using the party bits
*/
/*
* Copyright (c) 2005
* Simson L. Garfinkel and Basis Technology, Inc.
* All rights reserved.
*
* This code is derrived from software contributed by
* Simson L. Garfinkel
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Simson L. Garfinkel
* and Basis Technology Corp.
* 4. Neither the name of Simson Garfinkel, Basis Technology, or other
* contributors to this program may be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY SIMSON GARFINKEL, BASIS TECHNOLOGY,
* AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL SIMSON GARFINKEL, BAIS TECHNOLOGy,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "affconfig.h"
#include "afflib.h"
#include "afflib_i.h"
#include "utils.h"
#include <ctype.h>
#include <zlib.h>
#include <openssl/md5.h>
#include <openssl/sha.h>
#include <assert.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_TERM_H
#include <term.h>
#endif
#ifdef HAVE_NCURSES_TERM_H
#include <ncurses/term.h>
#endif
#ifdef WIN32
#include "unix4win32.h"
#include <malloc.h>
#endif
using namespace std;
using namespace aff;
const char *progname = "affix";
int opt_b = 0;
void usage()
{
printf("usage: %s filename\n",progname);
exit(0);
}
int recover(const char *fname)
{
AFFILE *af = af_open(fname,O_RDWR,0);
if(!af) af_err(1,fname);
/* Get the parity page */
size_t pagesize = af_page_size(af);
u_char *pagebuf = (unsigned char *)calloc(pagesize,1);
u_char *parity_buf = (unsigned char *)calloc(pagesize,1);
u_char *my_parity_buf = (unsigned char *)calloc(pagesize,1);
if(af_get_seg(af,AF_PARITY0,0,parity_buf,&pagesize)){
err(1,"Cannot read %s segment; cannot continue",AF_PARITY0);
}
/* Now, for every page:
* 1. Read the page & the signature
* 2. If the signature is good, add it into the parity buffer.
* - If not, put it on the list of bad segments.
*/
seglist segments(af);
seglist bad_sigs;
seglist good_sigs;
for(seglist::const_iterator seg = segments.begin();
seg != segments.end();
seg++){
if (seg->pagenumber()<0) continue; // only look for pages
switch(af_sig_verify_seg(af,seg->name.c_str())){
case AF_ERROR_SIG_NO_CERT:
errx(1,"%s: no public key in AFF file\n",af_filename(af));
case AF_ERROR_SIG_READ_ERROR:
errx(1,"no signature for segment '%s' --- recovery cannot continue",seg->name.c_str());
case AF_ERROR_SIG_BAD:
printf("%s has a bad signature\n",af_filename(af));
bad_sigs.push_back(*seg);
break;
case AF_SIG_GOOD:
good_sigs.push_back(*seg);
/* While the page is in the cache, make our parity buf */
pagesize = af_page_size(af);
if(af_get_page(af,seg->pagenumber(),pagebuf,&pagesize)){
err(1,"cannot read %s\n",seg->name.c_str());
}
for(u_int i=0;i<pagesize;i++){
my_parity_buf[i] ^= pagebuf[i];
}
break;
default:
break;
}
}
u_char *new_pagebuf = (unsigned char *)calloc(pagesize,1);
if(bad_sigs.size()>1) errx(1,"This program can only repair 1 bad page at the moment.");
if(bad_sigs.size()==0) errx(1,"There are no bad pages for this program to repair.");
printf("Attempting to repair %s\n",bad_sigs[0].name.c_str());
/* Calculate the page buf */
for(u_int i=0;i<pagesize;i++){
new_pagebuf[i] = parity_buf[i] ^ my_parity_buf[i];
}
/* Write the page back */
if(af_update_page(af,bad_sigs[0].pagenumber(),new_pagebuf,pagesize)){
err(1,"Cannot put page back");
}
/* Now verify the signature */
int r = af_sig_verify_seg(af,bad_sigs[0].name.c_str());
if(r==AF_SIG_GOOD){
printf("Page %s successfully repaired\n",bad_sigs[0].name.c_str());
}
else{
printf("Page %s could not be repaired; signature error code=%d\n",bad_sigs[0].name.c_str(),r);
exit(1);
}
af_close(af);
return 0;
}
int main(int argc,char **argv)
{
setvbuf(stdout,0,_IONBF,0); // turn off buffering
int ch;
while ((ch = getopt(argc, argv, "bh?v")) != -1) {
switch (ch) {
case 'h':
case '?':
default:
usage();
break;
case 'v':
printf("%s version %s\n",progname,PACKAGE_VERSION);
exit(0);
}
}
argc -= optind;
argv += optind;
if(argc<1){
usage();
}
recover(argv[0]);
exit(0);
}

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