1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
|
/*
* affrecover.cpp
*
* Recover broken pages of an AFF file using the party bits
* This file is a work of a US government employee and as such is in the Public domain.
* Simson L. Garfinkel, March 12, 2012
*/
#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 WIN32
#include "unix4win32.h"
#include <malloc.h>
#endif
using namespace std;
using namespace aff;
const char *progname = "affrecover";
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);
}
|
