pack-check.con commit Merge branch 'nd/remote-update-doc' (643a9ea)
   1#include "cache.h"
   2#include "repository.h"
   3#include "pack.h"
   4#include "pack-revindex.h"
   5#include "progress.h"
   6#include "packfile.h"
   7#include "object-store.h"
   8
   9struct idx_entry {
  10        off_t                offset;
  11        union idx_entry_object {
  12                const unsigned char *hash;
  13                struct object_id *oid;
  14        } oid;
  15        unsigned int nr;
  16};
  17
  18static int compare_entries(const void *e1, const void *e2)
  19{
  20        const struct idx_entry *entry1 = e1;
  21        const struct idx_entry *entry2 = e2;
  22        if (entry1->offset < entry2->offset)
  23                return -1;
  24        if (entry1->offset > entry2->offset)
  25                return 1;
  26        return 0;
  27}
  28
  29int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
  30                   off_t offset, off_t len, unsigned int nr)
  31{
  32        const uint32_t *index_crc;
  33        uint32_t data_crc = crc32(0, NULL, 0);
  34
  35        do {
  36                unsigned long avail;
  37                void *data = use_pack(p, w_curs, offset, &avail);
  38                if (avail > len)
  39                        avail = len;
  40                data_crc = crc32(data_crc, data, avail);
  41                offset += avail;
  42                len -= avail;
  43        } while (len);
  44
  45        index_crc = p->index_data;
  46        index_crc += 2 + 256 + p->num_objects * (the_hash_algo->rawsz/4) + nr;
  47
  48        return data_crc != ntohl(*index_crc);
  49}
  50
  51static int verify_packfile(struct packed_git *p,
  52                           struct pack_window **w_curs,
  53                           verify_fn fn,
  54                           struct progress *progress, uint32_t base_count)
  55
  56{
  57        off_t index_size = p->index_size;
  58        const unsigned char *index_base = p->index_data;
  59        git_hash_ctx ctx;
  60        unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;
  61        off_t offset = 0, pack_sig_ofs = 0;
  62        uint32_t nr_objects, i;
  63        int err = 0;
  64        struct idx_entry *entries;
  65
  66        if (!is_pack_valid(p))
  67                return error("packfile %s cannot be accessed", p->pack_name);
  68
  69        the_hash_algo->init_fn(&ctx);
  70        do {
  71                unsigned long remaining;
  72                unsigned char *in = use_pack(p, w_curs, offset, &remaining);
  73                offset += remaining;
  74                if (!pack_sig_ofs)
  75                        pack_sig_ofs = p->pack_size - the_hash_algo->rawsz;
  76                if (offset > pack_sig_ofs)
  77                        remaining -= (unsigned int)(offset - pack_sig_ofs);
  78                the_hash_algo->update_fn(&ctx, in, remaining);
  79        } while (offset < pack_sig_ofs);
  80        the_hash_algo->final_fn(hash, &ctx);
  81        pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
  82        if (hashcmp(hash, pack_sig))
  83                err = error("%s pack checksum mismatch",
  84                            p->pack_name);
  85        if (hashcmp(index_base + index_size - the_hash_algo->hexsz, pack_sig))
  86                err = error("%s pack checksum does not match its index",
  87                            p->pack_name);
  88        unuse_pack(w_curs);
  89
  90        /* Make sure everything reachable from idx is valid.  Since we
  91         * have verified that nr_objects matches between idx and pack,
  92         * we do not do scan-streaming check on the pack file.
  93         */
  94        nr_objects = p->num_objects;
  95        ALLOC_ARRAY(entries, nr_objects + 1);
  96        entries[nr_objects].offset = pack_sig_ofs;
  97        /* first sort entries by pack offset, since unpacking them is more efficient that way */
  98        for (i = 0; i < nr_objects; i++) {
  99                entries[i].oid.hash = nth_packed_object_sha1(p, i);
 100                if (!entries[i].oid.hash)
 101                        die("internal error pack-check nth-packed-object");
 102                entries[i].offset = nth_packed_object_offset(p, i);
 103                entries[i].nr = i;
 104        }
 105        QSORT(entries, nr_objects, compare_entries);
 106
 107        for (i = 0; i < nr_objects; i++) {
 108                void *data;
 109                enum object_type type;
 110                unsigned long size;
 111                off_t curpos;
 112                int data_valid;
 113
 114                if (p->index_version > 1) {
 115                        off_t offset = entries[i].offset;
 116                        off_t len = entries[i+1].offset - offset;
 117                        unsigned int nr = entries[i].nr;
 118                        if (check_pack_crc(p, w_curs, offset, len, nr))
 119                                err = error("index CRC mismatch for object %s "
 120                                            "from %s at offset %"PRIuMAX"",
 121                                            oid_to_hex(entries[i].oid.oid),
 122                                            p->pack_name, (uintmax_t)offset);
 123                }
 124
 125                curpos = entries[i].offset;
 126                type = unpack_object_header(p, w_curs, &curpos, &size);
 127                unuse_pack(w_curs);
 128
 129                if (type == OBJ_BLOB && big_file_threshold <= size) {
 130                        /*
 131                         * Let check_object_signature() check it with
 132                         * the streaming interface; no point slurping
 133                         * the data in-core only to discard.
 134                         */
 135                        data = NULL;
 136                        data_valid = 0;
 137                } else {
 138                        data = unpack_entry(the_repository, p, entries[i].offset, &type, &size);
 139                        data_valid = 1;
 140                }
 141
 142                if (data_valid && !data)
 143                        err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
 144                                    oid_to_hex(entries[i].oid.oid), p->pack_name,
 145                                    (uintmax_t)entries[i].offset);
 146                else if (check_object_signature(entries[i].oid.oid, data, size, type_name(type)))
 147                        err = error("packed %s from %s is corrupt",
 148                                    oid_to_hex(entries[i].oid.oid), p->pack_name);
 149                else if (fn) {
 150                        int eaten = 0;
 151                        err |= fn(entries[i].oid.oid, type, size, data, &eaten);
 152                        if (eaten)
 153                                data = NULL;
 154                }
 155                if (((base_count + i) & 1023) == 0)
 156                        display_progress(progress, base_count + i);
 157                free(data);
 158
 159        }
 160        display_progress(progress, base_count + i);
 161        free(entries);
 162
 163        return err;
 164}
 165
 166int verify_pack_index(struct packed_git *p)
 167{
 168        off_t index_size;
 169        const unsigned char *index_base;
 170        git_hash_ctx ctx;
 171        unsigned char hash[GIT_MAX_RAWSZ];
 172        int err = 0;
 173
 174        if (open_pack_index(p))
 175                return error("packfile %s index not opened", p->pack_name);
 176        index_size = p->index_size;
 177        index_base = p->index_data;
 178
 179        /* Verify SHA1 sum of the index file */
 180        the_hash_algo->init_fn(&ctx);
 181        the_hash_algo->update_fn(&ctx, index_base, (unsigned int)(index_size - the_hash_algo->rawsz));
 182        the_hash_algo->final_fn(hash, &ctx);
 183        if (hashcmp(hash, index_base + index_size - the_hash_algo->rawsz))
 184                err = error("Packfile index for %s hash mismatch",
 185                            p->pack_name);
 186        return err;
 187}
 188
 189int verify_pack(struct packed_git *p, verify_fn fn,
 190                struct progress *progress, uint32_t base_count)
 191{
 192        int err = 0;
 193        struct pack_window *w_curs = NULL;
 194
 195        err |= verify_pack_index(p);
 196        if (!p->index_data)
 197                return -1;
 198
 199        err |= verify_packfile(p, &w_curs, fn, progress, base_count);
 200        unuse_pack(&w_curs);
 201
 202        return err;
 203}