git
/
pack-check.c
202 строки · 5.5 Кб
1#define USE_THE_REPOSITORY_VARIABLE2
3#include "git-compat-util.h"4#include "environment.h"5#include "hex.h"6#include "repository.h"7#include "pack.h"8#include "progress.h"9#include "packfile.h"10#include "object-file.h"11#include "object-store-ll.h"12
13struct idx_entry {14off_t offset;15unsigned int nr;16};17
18static int compare_entries(const void *e1, const void *e2)19{
20const struct idx_entry *entry1 = e1;21const struct idx_entry *entry2 = e2;22if (entry1->offset < entry2->offset)23return -1;24if (entry1->offset > entry2->offset)25return 1;26return 0;27}
28
29int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,30off_t offset, off_t len, unsigned int nr)31{
32const uint32_t *index_crc;33uint32_t data_crc = crc32(0, NULL, 0);34
35do {36unsigned long avail;37void *data = use_pack(p, w_curs, offset, &avail);38if (avail > len)39avail = len;40data_crc = crc32(data_crc, data, avail);41offset += avail;42len -= avail;43} while (len);44
45index_crc = p->index_data;46index_crc += 2 + 256 + (size_t)p->num_objects * (the_hash_algo->rawsz/4) + nr;47
48return data_crc != ntohl(*index_crc);49}
50
51static int verify_packfile(struct repository *r,52struct packed_git *p,53struct pack_window **w_curs,54verify_fn fn,55struct progress *progress, uint32_t base_count)56
57{
58off_t index_size = p->index_size;59const unsigned char *index_base = p->index_data;60git_hash_ctx ctx;61unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;62off_t offset = 0, pack_sig_ofs = 0;63uint32_t nr_objects, i;64int err = 0;65struct idx_entry *entries;66
67if (!is_pack_valid(p))68return error("packfile %s cannot be accessed", p->pack_name);69
70r->hash_algo->init_fn(&ctx);71do {72unsigned long remaining;73unsigned char *in = use_pack(p, w_curs, offset, &remaining);74offset += remaining;75if (!pack_sig_ofs)76pack_sig_ofs = p->pack_size - r->hash_algo->rawsz;77if (offset > pack_sig_ofs)78remaining -= (unsigned int)(offset - pack_sig_ofs);79r->hash_algo->update_fn(&ctx, in, remaining);80} while (offset < pack_sig_ofs);81r->hash_algo->final_fn(hash, &ctx);82pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);83if (!hasheq(hash, pack_sig, the_repository->hash_algo))84err = error("%s pack checksum mismatch",85p->pack_name);86if (!hasheq(index_base + index_size - r->hash_algo->hexsz, pack_sig,87the_repository->hash_algo))88err = error("%s pack checksum does not match its index",89p->pack_name);90unuse_pack(w_curs);91
92/* Make sure everything reachable from idx is valid. Since we93* have verified that nr_objects matches between idx and pack,
94* we do not do scan-streaming check on the pack file.
95*/
96nr_objects = p->num_objects;97ALLOC_ARRAY(entries, nr_objects + 1);98entries[nr_objects].offset = pack_sig_ofs;99/* first sort entries by pack offset, since unpacking them is more efficient that way */100for (i = 0; i < nr_objects; i++) {101entries[i].offset = nth_packed_object_offset(p, i);102entries[i].nr = i;103}104QSORT(entries, nr_objects, compare_entries);105
106for (i = 0; i < nr_objects; i++) {107void *data;108struct object_id oid;109enum object_type type;110unsigned long size;111off_t curpos;112int data_valid;113
114if (nth_packed_object_id(&oid, p, entries[i].nr) < 0)115BUG("unable to get oid of object %lu from %s",116(unsigned long)entries[i].nr, p->pack_name);117
118if (p->index_version > 1) {119off_t offset = entries[i].offset;120off_t len = entries[i+1].offset - offset;121unsigned int nr = entries[i].nr;122if (check_pack_crc(p, w_curs, offset, len, nr))123err = error("index CRC mismatch for object %s "124"from %s at offset %"PRIuMAX"",125oid_to_hex(&oid),126p->pack_name, (uintmax_t)offset);127}128
129curpos = entries[i].offset;130type = unpack_object_header(p, w_curs, &curpos, &size);131unuse_pack(w_curs);132
133if (type == OBJ_BLOB && big_file_threshold <= size) {134/*135* Let stream_object_signature() check it with
136* the streaming interface; no point slurping
137* the data in-core only to discard.
138*/
139data = NULL;140data_valid = 0;141} else {142data = unpack_entry(r, p, entries[i].offset, &type, &size);143data_valid = 1;144}145
146if (data_valid && !data)147err = error("cannot unpack %s from %s at offset %"PRIuMAX"",148oid_to_hex(&oid), p->pack_name,149(uintmax_t)entries[i].offset);150else if (data && check_object_signature(r, &oid, data, size,151type) < 0)152err = error("packed %s from %s is corrupt",153oid_to_hex(&oid), p->pack_name);154else if (!data && stream_object_signature(r, &oid) < 0)155err = error("packed %s from %s is corrupt",156oid_to_hex(&oid), p->pack_name);157else if (fn) {158int eaten = 0;159err |= fn(&oid, type, size, data, &eaten);160if (eaten)161data = NULL;162}163if (((base_count + i) & 1023) == 0)164display_progress(progress, base_count + i);165free(data);166
167}168display_progress(progress, base_count + i);169free(entries);170
171return err;172}
173
174int verify_pack_index(struct packed_git *p)175{
176int err = 0;177
178if (open_pack_index(p))179return error("packfile %s index not opened", p->pack_name);180
181/* Verify SHA1 sum of the index file */182if (!hashfile_checksum_valid(p->index_data, p->index_size))183err = error("Packfile index for %s hash mismatch",184p->pack_name);185return err;186}
187
188int verify_pack(struct repository *r, struct packed_git *p, verify_fn fn,189struct progress *progress, uint32_t base_count)190{
191int err = 0;192struct pack_window *w_curs = NULL;193
194err |= verify_pack_index(p);195if (!p->index_data)196return -1;197
198err |= verify_packfile(r, p, &w_curs, fn, progress, base_count);199unuse_pack(&w_curs);200
201return err;202}
203