git/pack-check.c
Jeff King 67947c34ae convert "hashcmp() != 0" to "!hasheq()"
This rounds out the previous three patches, covering the
inequality logic for the "hash" variant of the functions.

As with the previous three, the accompanying code changes
are the mechanical result of applying the coccinelle patch;
see those patches for more discussion.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29 11:32:49 -07:00

204 lines
5.6 KiB
C

#include "cache.h"
#include "repository.h"
#include "pack.h"
#include "pack-revindex.h"
#include "progress.h"
#include "packfile.h"
#include "object-store.h"
struct idx_entry {
off_t offset;
union idx_entry_object {
const unsigned char *hash;
struct object_id *oid;
} oid;
unsigned int nr;
};
static int compare_entries(const void *e1, const void *e2)
{
const struct idx_entry *entry1 = e1;
const struct idx_entry *entry2 = e2;
if (entry1->offset < entry2->offset)
return -1;
if (entry1->offset > entry2->offset)
return 1;
return 0;
}
int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
off_t offset, off_t len, unsigned int nr)
{
const uint32_t *index_crc;
uint32_t data_crc = crc32(0, NULL, 0);
do {
unsigned long avail;
void *data = use_pack(p, w_curs, offset, &avail);
if (avail > len)
avail = len;
data_crc = crc32(data_crc, data, avail);
offset += avail;
len -= avail;
} while (len);
index_crc = p->index_data;
index_crc += 2 + 256 + p->num_objects * (the_hash_algo->rawsz/4) + nr;
return data_crc != ntohl(*index_crc);
}
static int verify_packfile(struct packed_git *p,
struct pack_window **w_curs,
verify_fn fn,
struct progress *progress, uint32_t base_count)
{
off_t index_size = p->index_size;
const unsigned char *index_base = p->index_data;
git_hash_ctx ctx;
unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;
off_t offset = 0, pack_sig_ofs = 0;
uint32_t nr_objects, i;
int err = 0;
struct idx_entry *entries;
if (!is_pack_valid(p))
return error("packfile %s cannot be accessed", p->pack_name);
the_hash_algo->init_fn(&ctx);
do {
unsigned long remaining;
unsigned char *in = use_pack(p, w_curs, offset, &remaining);
offset += remaining;
if (!pack_sig_ofs)
pack_sig_ofs = p->pack_size - the_hash_algo->rawsz;
if (offset > pack_sig_ofs)
remaining -= (unsigned int)(offset - pack_sig_ofs);
the_hash_algo->update_fn(&ctx, in, remaining);
} while (offset < pack_sig_ofs);
the_hash_algo->final_fn(hash, &ctx);
pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
if (!hasheq(hash, pack_sig))
err = error("%s pack checksum mismatch",
p->pack_name);
if (!hasheq(index_base + index_size - the_hash_algo->hexsz, pack_sig))
err = error("%s pack checksum does not match its index",
p->pack_name);
unuse_pack(w_curs);
/* Make sure everything reachable from idx is valid. Since we
* have verified that nr_objects matches between idx and pack,
* we do not do scan-streaming check on the pack file.
*/
nr_objects = p->num_objects;
ALLOC_ARRAY(entries, nr_objects + 1);
entries[nr_objects].offset = pack_sig_ofs;
/* first sort entries by pack offset, since unpacking them is more efficient that way */
for (i = 0; i < nr_objects; i++) {
entries[i].oid.hash = nth_packed_object_sha1(p, i);
if (!entries[i].oid.hash)
die("internal error pack-check nth-packed-object");
entries[i].offset = nth_packed_object_offset(p, i);
entries[i].nr = i;
}
QSORT(entries, nr_objects, compare_entries);
for (i = 0; i < nr_objects; i++) {
void *data;
enum object_type type;
unsigned long size;
off_t curpos;
int data_valid;
if (p->index_version > 1) {
off_t offset = entries[i].offset;
off_t len = entries[i+1].offset - offset;
unsigned int nr = entries[i].nr;
if (check_pack_crc(p, w_curs, offset, len, nr))
err = error("index CRC mismatch for object %s "
"from %s at offset %"PRIuMAX"",
oid_to_hex(entries[i].oid.oid),
p->pack_name, (uintmax_t)offset);
}
curpos = entries[i].offset;
type = unpack_object_header(p, w_curs, &curpos, &size);
unuse_pack(w_curs);
if (type == OBJ_BLOB && big_file_threshold <= size) {
/*
* Let check_object_signature() check it with
* the streaming interface; no point slurping
* the data in-core only to discard.
*/
data = NULL;
data_valid = 0;
} else {
data = unpack_entry(the_repository, p, entries[i].offset, &type, &size);
data_valid = 1;
}
if (data_valid && !data)
err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
oid_to_hex(entries[i].oid.oid), p->pack_name,
(uintmax_t)entries[i].offset);
else if (check_object_signature(entries[i].oid.oid, data, size, type_name(type)))
err = error("packed %s from %s is corrupt",
oid_to_hex(entries[i].oid.oid), p->pack_name);
else if (fn) {
int eaten = 0;
err |= fn(entries[i].oid.oid, type, size, data, &eaten);
if (eaten)
data = NULL;
}
if (((base_count + i) & 1023) == 0)
display_progress(progress, base_count + i);
free(data);
}
display_progress(progress, base_count + i);
free(entries);
return err;
}
int verify_pack_index(struct packed_git *p)
{
off_t index_size;
const unsigned char *index_base;
git_hash_ctx ctx;
unsigned char hash[GIT_MAX_RAWSZ];
int err = 0;
if (open_pack_index(p))
return error("packfile %s index not opened", p->pack_name);
index_size = p->index_size;
index_base = p->index_data;
/* Verify SHA1 sum of the index file */
the_hash_algo->init_fn(&ctx);
the_hash_algo->update_fn(&ctx, index_base, (unsigned int)(index_size - the_hash_algo->rawsz));
the_hash_algo->final_fn(hash, &ctx);
if (!hasheq(hash, index_base + index_size - the_hash_algo->rawsz))
err = error("Packfile index for %s hash mismatch",
p->pack_name);
return err;
}
int verify_pack(struct packed_git *p, verify_fn fn,
struct progress *progress, uint32_t base_count)
{
int err = 0;
struct pack_window *w_curs = NULL;
err |= verify_pack_index(p);
if (!p->index_data)
return -1;
err |= verify_packfile(p, &w_curs, fn, progress, base_count);
unuse_pack(&w_curs);
return err;
}