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#include "stdinc.h"
#include "dat.h"
#include "fns.h"
static int verbose;
void
usage(void)
{
fprint(2, "usage: verifyarena [-v]\n");
threadexitsall(0);
}
static void
readblock(uchar *buf, int n)
{
int nr, m;
for(nr = 0; nr < n; nr += m){
m = n - nr;
m = read(0, &buf[nr], m);
if(m <= 0)
sysfatal("can't read arena from standard input: %r");
}
}
static void
verifyarena(void)
{
Arena arena;
ArenaHead head;
ZBlock *b;
DigestState s;
u64int n, e;
u32int bs;
u8int score[VtScoreSize];
fprint(2, "verify arena from standard input\n");
memset(&arena, 0, sizeof arena);
memset(&s, 0, sizeof s);
/*
* read the little bit, which will included the header
*/
bs = MaxIoSize;
b = alloczblock(bs, 0, 0);
readblock(b->data, HeadSize);
sha1(b->data, HeadSize, nil, &s);
if(unpackarenahead(&head, b->data) < 0)
sysfatal("corrupted arena header: %r");
if(head.version != ArenaVersion4 && head.version != ArenaVersion5)
fprint(2, "warning: unknown arena version %d\n", head.version);
/*
* now we know how much to read
* read everything but the last block, which is special
*/
e = head.size - head.blocksize;
for(n = HeadSize; n < e; n += bs){
if(n + bs > e)
bs = e - n;
readblock(b->data, bs);
sha1(b->data, bs, nil, &s);
}
/*
* read the last block update the sum.
* the sum is calculated assuming the slot for the sum is zero.
*/
bs = head.blocksize;
readblock(b->data, bs);
sha1(b->data, bs-VtScoreSize, nil, &s);
sha1(zeroscore, VtScoreSize, nil, &s);
sha1(nil, 0, score, &s);
/*
* validity check on the trailer
*/
arena.blocksize = head.blocksize;
if(unpackarena(&arena, b->data) < 0)
sysfatal("corrupted arena trailer: %r");
scorecp(arena.score, &b->data[arena.blocksize - VtScoreSize]);
if(namecmp(arena.name, head.name) != 0)
sysfatal("arena header and trailer names clash: %s vs. %s\n", head.name, arena.name);
if(arena.version != head.version)
sysfatal("arena header and trailer versions clash: %d vs. %d\n", head.version, arena.version);
arena.size = head.size - 2 * head.blocksize;
/*
* check for no checksum or the same
*/
if(scorecmp(score, arena.score) != 0){
if(scorecmp(zeroscore, arena.score) != 0)
fprint(2, "warning: mismatched checksums for arena=%s, found=%V calculated=%V",
arena.name, arena.score, score);
scorecp(arena.score, score);
}else
fprint(2, "matched score\n");
printarena(2, &arena);
}
void
threadmain(int argc, char *argv[])
{
ventifmtinstall();
statsinit();
ARGBEGIN{
case 'v':
verbose++;
break;
default:
usage();
break;
}ARGEND
readonly = 1;
if(argc != 0)
usage();
verifyarena();
threadexitsall(0);
}
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