From 6ab3b8b8b8dc94c8e4caefb1d368cc704e70d38b Mon Sep 17 00:00:00 2001 From: Derrick Stolee Date: Thu, 18 Feb 2021 14:07:36 +0000 Subject: [PATCH] midx: use chunk-format read API Instead of parsing the table of contents directly, use the chunk-format API methods read_table_of_contents() and pair_chunk(). In particular, we can use the return value of pair_chunk() to generate an error when a required chunk is missing. Signed-off-by: Derrick Stolee Signed-off-by: Junio C Hamano --- midx.c | 71 +++++++++++++------------------------ t/t5319-multi-pack-index.sh | 6 ++-- 2 files changed, 28 insertions(+), 49 deletions(-) diff --git a/midx.c b/midx.c index d2fd9c10fe..d7ea0d1375 100644 --- a/midx.c +++ b/midx.c @@ -28,7 +28,6 @@ #define MIDX_CHUNKID_OIDLOOKUP 0x4f49444c /* "OIDL" */ #define MIDX_CHUNKID_OBJECTOFFSETS 0x4f4f4646 /* "OOFF" */ #define MIDX_CHUNKID_LARGEOFFSETS 0x4c4f4646 /* "LOFF" */ -#define MIDX_CHUNKLOOKUP_WIDTH (sizeof(uint32_t) + sizeof(uint64_t)) #define MIDX_CHUNK_FANOUT_SIZE (sizeof(uint32_t) * 256) #define MIDX_CHUNK_OFFSET_WIDTH (2 * sizeof(uint32_t)) #define MIDX_CHUNK_LARGE_OFFSET_WIDTH (sizeof(uint64_t)) @@ -53,6 +52,19 @@ static char *get_midx_filename(const char *object_dir) return xstrfmt("%s/pack/multi-pack-index", object_dir); } +static int midx_read_oid_fanout(const unsigned char *chunk_start, + size_t chunk_size, void *data) +{ + struct multi_pack_index *m = data; + m->chunk_oid_fanout = (uint32_t *)chunk_start; + + if (chunk_size != 4 * 256) { + error(_("multi-pack-index OID fanout is of the wrong size")); + return 1; + } + return 0; +} + struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local) { struct multi_pack_index *m = NULL; @@ -64,6 +76,7 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local char *midx_name = get_midx_filename(object_dir); uint32_t i; const char *cur_pack_name; + struct chunkfile *cf = NULL; fd = git_open(midx_name); @@ -113,58 +126,23 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local m->num_packs = get_be32(m->data + MIDX_BYTE_NUM_PACKS); - for (i = 0; i < m->num_chunks; i++) { - uint32_t chunk_id = get_be32(m->data + MIDX_HEADER_SIZE + - MIDX_CHUNKLOOKUP_WIDTH * i); - uint64_t chunk_offset = get_be64(m->data + MIDX_HEADER_SIZE + 4 + - MIDX_CHUNKLOOKUP_WIDTH * i); + cf = init_chunkfile(NULL); - if (chunk_offset >= m->data_len) - die(_("invalid chunk offset (too large)")); + if (read_table_of_contents(cf, m->data, midx_size, + MIDX_HEADER_SIZE, m->num_chunks)) + goto cleanup_fail; - switch (chunk_id) { - case MIDX_CHUNKID_PACKNAMES: - m->chunk_pack_names = m->data + chunk_offset; - break; - - case MIDX_CHUNKID_OIDFANOUT: - m->chunk_oid_fanout = (uint32_t *)(m->data + chunk_offset); - break; - - case MIDX_CHUNKID_OIDLOOKUP: - m->chunk_oid_lookup = m->data + chunk_offset; - break; - - case MIDX_CHUNKID_OBJECTOFFSETS: - m->chunk_object_offsets = m->data + chunk_offset; - break; - - case MIDX_CHUNKID_LARGEOFFSETS: - m->chunk_large_offsets = m->data + chunk_offset; - break; - - case 0: - die(_("terminating multi-pack-index chunk id appears earlier than expected")); - break; - - default: - /* - * Do nothing on unrecognized chunks, allowing future - * extensions to add optional chunks. - */ - break; - } - } - - if (!m->chunk_pack_names) + if (pair_chunk(cf, MIDX_CHUNKID_PACKNAMES, &m->chunk_pack_names) == CHUNK_NOT_FOUND) die(_("multi-pack-index missing required pack-name chunk")); - if (!m->chunk_oid_fanout) + if (read_chunk(cf, MIDX_CHUNKID_OIDFANOUT, midx_read_oid_fanout, m) == CHUNK_NOT_FOUND) die(_("multi-pack-index missing required OID fanout chunk")); - if (!m->chunk_oid_lookup) + if (pair_chunk(cf, MIDX_CHUNKID_OIDLOOKUP, &m->chunk_oid_lookup) == CHUNK_NOT_FOUND) die(_("multi-pack-index missing required OID lookup chunk")); - if (!m->chunk_object_offsets) + if (pair_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, &m->chunk_object_offsets) == CHUNK_NOT_FOUND) die(_("multi-pack-index missing required object offsets chunk")); + pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets); + m->num_objects = ntohl(m->chunk_oid_fanout[255]); m->pack_names = xcalloc(m->num_packs, sizeof(*m->pack_names)); @@ -190,6 +168,7 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local cleanup_fail: free(m); free(midx_name); + free(cf); if (midx_map) munmap(midx_map, midx_size); if (0 <= fd) diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh index 297de502a9..ad4e878b65 100755 --- a/t/t5319-multi-pack-index.sh +++ b/t/t5319-multi-pack-index.sh @@ -314,12 +314,12 @@ test_expect_success 'verify bad OID version' ' test_expect_success 'verify truncated chunk count' ' corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\01" $objdir \ - "missing required" + "final chunk has non-zero id" ' test_expect_success 'verify extended chunk count' ' corrupt_midx_and_verify $MIDX_BYTE_CHUNK_COUNT "\07" $objdir \ - "terminating multi-pack-index chunk id appears earlier than expected" + "terminating chunk id appears earlier than expected" ' test_expect_success 'verify missing required chunk' ' @@ -329,7 +329,7 @@ test_expect_success 'verify missing required chunk' ' test_expect_success 'verify invalid chunk offset' ' corrupt_midx_and_verify $MIDX_BYTE_CHUNK_OFFSET "\01" $objdir \ - "invalid chunk offset (too large)" + "improper chunk offset(s)" ' test_expect_success 'verify packnames out of order' '