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![Nicolas Pitre](/assets/img/avatar_default.png)
When a pack gets corrupted, its SHA1 checksum will fail. However, this is more useful to let the test go on in order to find the actual problem location than only complain about the SHA1 mismatch and bail out. Also, it is more useful to compare the stored pack SHA1 with the one in the index file instead of the computed SHA1 since the computed SHA1 from a corrupted pack won't match the one stored in the index either. Finally a few code and message cleanups were thrown in as a bonus. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
194 lines
5.2 KiB
C
194 lines
5.2 KiB
C
#include "cache.h"
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#include "pack.h"
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#include "pack-revindex.h"
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struct idx_entry
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{
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const unsigned char *sha1;
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off_t offset;
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};
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static int compare_entries(const void *e1, const void *e2)
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{
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const struct idx_entry *entry1 = e1;
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const struct idx_entry *entry2 = e2;
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if (entry1->offset < entry2->offset)
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return -1;
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if (entry1->offset > entry2->offset)
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return 1;
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return 0;
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}
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static int verify_packfile(struct packed_git *p,
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struct pack_window **w_curs)
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{
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off_t index_size = p->index_size;
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const unsigned char *index_base = p->index_data;
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SHA_CTX ctx;
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unsigned char sha1[20], *pack_sig;
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off_t offset = 0, pack_sig_ofs = p->pack_size - 20;
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uint32_t nr_objects, i;
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int err = 0;
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struct idx_entry *entries;
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/* Note that the pack header checks are actually performed by
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* use_pack when it first opens the pack file. If anything
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* goes wrong during those checks then the call will die out
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* immediately.
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*/
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SHA1_Init(&ctx);
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while (offset < pack_sig_ofs) {
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unsigned int remaining;
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unsigned char *in = use_pack(p, w_curs, offset, &remaining);
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offset += remaining;
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if (offset > pack_sig_ofs)
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remaining -= (unsigned int)(offset - pack_sig_ofs);
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SHA1_Update(&ctx, in, remaining);
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}
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SHA1_Final(sha1, &ctx);
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pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
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if (hashcmp(sha1, pack_sig))
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err = error("%s SHA1 checksum mismatch",
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p->pack_name);
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if (hashcmp(index_base + index_size - 40, pack_sig))
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err = error("%s SHA1 does not match its inddex",
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p->pack_name);
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unuse_pack(w_curs);
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/* Make sure everything reachable from idx is valid. Since we
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* have verified that nr_objects matches between idx and pack,
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* we do not do scan-streaming check on the pack file.
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*/
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nr_objects = p->num_objects;
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entries = xmalloc(nr_objects * sizeof(*entries));
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/* first sort entries by pack offset, since unpacking them is more efficient that way */
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for (i = 0; i < nr_objects; i++) {
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entries[i].sha1 = nth_packed_object_sha1(p, i);
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if (!entries[i].sha1)
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die("internal error pack-check nth-packed-object");
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entries[i].offset = find_pack_entry_one(entries[i].sha1, p);
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if (!entries[i].offset)
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die("internal error pack-check find-pack-entry-one");
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}
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qsort(entries, nr_objects, sizeof(*entries), compare_entries);
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for (i = 0; i < nr_objects; i++) {
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void *data;
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enum object_type type;
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unsigned long size;
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data = unpack_entry(p, entries[i].offset, &type, &size);
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if (!data) {
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err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
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sha1_to_hex(entries[i].sha1), p->pack_name,
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(uintmax_t)entries[i].offset);
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break;
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}
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if (check_sha1_signature(entries[i].sha1, data, size, typename(type))) {
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err = error("packed %s from %s is corrupt",
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sha1_to_hex(entries[i].sha1), p->pack_name);
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free(data);
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break;
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}
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free(data);
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}
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free(entries);
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return err;
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}
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#define MAX_CHAIN 50
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static void show_pack_info(struct packed_git *p)
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{
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uint32_t nr_objects, i, chain_histogram[MAX_CHAIN+1];
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nr_objects = p->num_objects;
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memset(chain_histogram, 0, sizeof(chain_histogram));
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init_pack_revindex();
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for (i = 0; i < nr_objects; i++) {
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const unsigned char *sha1;
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unsigned char base_sha1[20];
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const char *type;
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unsigned long size;
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unsigned long store_size;
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off_t offset;
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unsigned int delta_chain_length;
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sha1 = nth_packed_object_sha1(p, i);
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if (!sha1)
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die("internal error pack-check nth-packed-object");
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offset = find_pack_entry_one(sha1, p);
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if (!offset)
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die("internal error pack-check find-pack-entry-one");
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type = packed_object_info_detail(p, offset, &size, &store_size,
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&delta_chain_length,
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base_sha1);
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printf("%s ", sha1_to_hex(sha1));
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if (!delta_chain_length)
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printf("%-6s %lu %lu %"PRIuMAX"\n",
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type, size, store_size, (uintmax_t)offset);
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else {
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printf("%-6s %lu %lu %"PRIuMAX" %u %s\n",
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type, size, store_size, (uintmax_t)offset,
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delta_chain_length, sha1_to_hex(base_sha1));
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if (delta_chain_length <= MAX_CHAIN)
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chain_histogram[delta_chain_length]++;
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else
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chain_histogram[0]++;
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}
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}
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for (i = 0; i <= MAX_CHAIN; i++) {
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if (!chain_histogram[i])
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continue;
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printf("chain length = %d: %d object%s\n", i,
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chain_histogram[i], chain_histogram[i] > 1 ? "s" : "");
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}
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if (chain_histogram[0])
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printf("chain length > %d: %d object%s\n", MAX_CHAIN,
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chain_histogram[0], chain_histogram[0] > 1 ? "s" : "");
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}
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int verify_pack(struct packed_git *p, int verbose)
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{
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off_t index_size;
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const unsigned char *index_base;
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SHA_CTX ctx;
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unsigned char sha1[20];
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int err = 0;
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struct pack_window *w_curs = NULL;
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if (open_pack_index(p))
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return error("packfile %s index not opened", p->pack_name);
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index_size = p->index_size;
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index_base = p->index_data;
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/* Verify SHA1 sum of the index file */
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SHA1_Init(&ctx);
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SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
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SHA1_Final(sha1, &ctx);
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if (hashcmp(sha1, index_base + index_size - 20))
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err = error("Packfile index for %s SHA1 mismatch",
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p->pack_name);
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/* Verify pack file */
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err |= verify_packfile(p, &w_curs);
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unuse_pack(&w_curs);
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if (verbose) {
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if (err)
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printf("%s: bad\n", p->pack_name);
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else {
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show_pack_info(p);
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printf("%s: ok\n", p->pack_name);
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}
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}
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return err;
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}
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