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author | rsc <devnull@localhost> | 2005-07-12 15:23:36 +0000 |
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committer | rsc <devnull@localhost> | 2005-07-12 15:23:36 +0000 |
commit | a0d146edd7a7de6236a0d60baafeeb59f8452aae (patch) | |
tree | b55baa526d9f5adfc73246e6ee2fadf455e0b7a2 /src/cmd/venti/srv/verifyarena.c | |
parent | 88bb285e3d87ec2508840af33f7e0af53ec3c13c (diff) | |
download | plan9port-a0d146edd7a7de6236a0d60baafeeb59f8452aae.tar.gz plan9port-a0d146edd7a7de6236a0d60baafeeb59f8452aae.tar.bz2 plan9port-a0d146edd7a7de6236a0d60baafeeb59f8452aae.zip |
return of venti
Diffstat (limited to 'src/cmd/venti/srv/verifyarena.c')
-rw-r--r-- | src/cmd/venti/srv/verifyarena.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/src/cmd/venti/srv/verifyarena.c b/src/cmd/venti/srv/verifyarena.c new file mode 100644 index 00000000..5236c093 --- /dev/null +++ b/src/cmd/venti/srv/verifyarena.c @@ -0,0 +1,127 @@ +#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); +} |