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![Nicolas Pitre](/assets/img/avatar_default.png)
To do so, check_pack_crc() moved from builtin-pack-objects.c to pack-check.c where it is more logical to share. Signed-off-by: Nicolas Pitre <nico@cam.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
162 lines
4.4 KiB
C
162 lines
4.4 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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off_t offset;
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const unsigned char *sha1;
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unsigned int nr;
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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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int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
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off_t offset, off_t len, unsigned int nr)
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{
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const uint32_t *index_crc;
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uint32_t data_crc = crc32(0, Z_NULL, 0);
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do {
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unsigned int avail;
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void *data = use_pack(p, w_curs, offset, &avail);
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if (avail > len)
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avail = len;
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data_crc = crc32(data_crc, data, avail);
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offset += avail;
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len -= avail;
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} while (len);
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index_crc = p->index_data;
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index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
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return data_crc != ntohl(*index_crc);
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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 + 1) * sizeof(*entries));
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entries[nr_objects].offset = pack_sig_ofs;
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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 = nth_packed_object_offset(p, i);
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entries[i].nr = i;
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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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if (p->index_version > 1) {
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off_t offset = entries[i].offset;
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off_t len = entries[i+1].offset - offset;
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unsigned int nr = entries[i].nr;
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if (check_pack_crc(p, w_curs, offset, len, nr))
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err = error("index CRC mismatch for object %s "
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"from %s at offset %"PRIuMAX"",
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sha1_to_hex(entries[i].sha1),
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p->pack_name, (uintmax_t)offset);
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}
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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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int verify_pack(struct packed_git *p)
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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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return err;
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}
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