From c41a4a9468b0c728e77ec5d97da7bfb63776ac3f Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Tue, 24 Jun 2008 23:19:02 -0400 Subject: verify-pack: check packed object CRC when using index version 2 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 Signed-off-by: Junio C Hamano --- pack-check.c | 39 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 37 insertions(+), 2 deletions(-) (limited to 'pack-check.c') diff --git a/pack-check.c b/pack-check.c index 5f02a65b6e..f596bf2db5 100644 --- a/pack-check.c +++ b/pack-check.c @@ -4,8 +4,9 @@ struct idx_entry { - const unsigned char *sha1; off_t offset; + const unsigned char *sha1; + unsigned int nr; }; static int compare_entries(const void *e1, const void *e2) @@ -19,6 +20,28 @@ static int compare_entries(const void *e1, const void *e2) 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, Z_NULL, 0); + + do { + unsigned int 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 * (20/4) + nr; + + return data_crc != ntohl(*index_crc); +} + static int verify_packfile(struct packed_git *p, struct pack_window **w_curs) { @@ -61,13 +84,15 @@ static int verify_packfile(struct packed_git *p, * we do not do scan-streaming check on the pack file. */ nr_objects = p->num_objects; - entries = xmalloc(nr_objects * sizeof(*entries)); + entries = xmalloc((nr_objects + 1) * sizeof(*entries)); + 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].sha1 = nth_packed_object_sha1(p, i); if (!entries[i].sha1) 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, sizeof(*entries), compare_entries); @@ -76,6 +101,16 @@ static int verify_packfile(struct packed_git *p, enum object_type type; unsigned long size; + 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"", + sha1_to_hex(entries[i].sha1), + p->pack_name, (uintmax_t)offset); + } data = unpack_entry(p, entries[i].offset, &type, &size); if (!data) { err = error("cannot unpack %s from %s at offset %"PRIuMAX"", -- cgit v1.2.3