pack-check.con commit gitweb: Fix handling of non-ASCII characters in inserted HTML files (2dcb5e1)
   1#include "cache.h"
   2#include "pack.h"
   3#include "pack-revindex.h"
   4
   5struct idx_entry
   6{
   7        off_t                offset;
   8        const unsigned char *sha1;
   9        unsigned int nr;
  10};
  11
  12static int compare_entries(const void *e1, const void *e2)
  13{
  14        const struct idx_entry *entry1 = e1;
  15        const struct idx_entry *entry2 = e2;
  16        if (entry1->offset < entry2->offset)
  17                return -1;
  18        if (entry1->offset > entry2->offset)
  19                return 1;
  20        return 0;
  21}
  22
  23int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
  24                   off_t offset, off_t len, unsigned int nr)
  25{
  26        const uint32_t *index_crc;
  27        uint32_t data_crc = crc32(0, Z_NULL, 0);
  28
  29        do {
  30                unsigned int avail;
  31                void *data = use_pack(p, w_curs, offset, &avail);
  32                if (avail > len)
  33                        avail = len;
  34                data_crc = crc32(data_crc, data, avail);
  35                offset += avail;
  36                len -= avail;
  37        } while (len);
  38
  39        index_crc = p->index_data;
  40        index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
  41
  42        return data_crc != ntohl(*index_crc);
  43}
  44
  45static int verify_packfile(struct packed_git *p,
  46                struct pack_window **w_curs)
  47{
  48        off_t index_size = p->index_size;
  49        const unsigned char *index_base = p->index_data;
  50        git_SHA_CTX ctx;
  51        unsigned char sha1[20], *pack_sig;
  52        off_t offset = 0, pack_sig_ofs = p->pack_size - 20;
  53        uint32_t nr_objects, i;
  54        int err = 0;
  55        struct idx_entry *entries;
  56
  57        /* Note that the pack header checks are actually performed by
  58         * use_pack when it first opens the pack file.  If anything
  59         * goes wrong during those checks then the call will die out
  60         * immediately.
  61         */
  62
  63        git_SHA1_Init(&ctx);
  64        while (offset < pack_sig_ofs) {
  65                unsigned int remaining;
  66                unsigned char *in = use_pack(p, w_curs, offset, &remaining);
  67                offset += remaining;
  68                if (offset > pack_sig_ofs)
  69                        remaining -= (unsigned int)(offset - pack_sig_ofs);
  70                git_SHA1_Update(&ctx, in, remaining);
  71        }
  72        git_SHA1_Final(sha1, &ctx);
  73        pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
  74        if (hashcmp(sha1, pack_sig))
  75                err = error("%s SHA1 checksum mismatch",
  76                            p->pack_name);
  77        if (hashcmp(index_base + index_size - 40, pack_sig))
  78                err = error("%s SHA1 does not match its inddex",
  79                            p->pack_name);
  80        unuse_pack(w_curs);
  81
  82        /* Make sure everything reachable from idx is valid.  Since we
  83         * have verified that nr_objects matches between idx and pack,
  84         * we do not do scan-streaming check on the pack file.
  85         */
  86        nr_objects = p->num_objects;
  87        entries = xmalloc((nr_objects + 1) * sizeof(*entries));
  88        entries[nr_objects].offset = pack_sig_ofs;
  89        /* first sort entries by pack offset, since unpacking them is more efficient that way */
  90        for (i = 0; i < nr_objects; i++) {
  91                entries[i].sha1 = nth_packed_object_sha1(p, i);
  92                if (!entries[i].sha1)
  93                        die("internal error pack-check nth-packed-object");
  94                entries[i].offset = nth_packed_object_offset(p, i);
  95                entries[i].nr = i;
  96        }
  97        qsort(entries, nr_objects, sizeof(*entries), compare_entries);
  98
  99        for (i = 0; i < nr_objects; i++) {
 100                void *data;
 101                enum object_type type;
 102                unsigned long size;
 103
 104                if (p->index_version > 1) {
 105                        off_t offset = entries[i].offset;
 106                        off_t len = entries[i+1].offset - offset;
 107                        unsigned int nr = entries[i].nr;
 108                        if (check_pack_crc(p, w_curs, offset, len, nr))
 109                                err = error("index CRC mismatch for object %s "
 110                                            "from %s at offset %"PRIuMAX"",
 111                                            sha1_to_hex(entries[i].sha1),
 112                                            p->pack_name, (uintmax_t)offset);
 113                }
 114                data = unpack_entry(p, entries[i].offset, &type, &size);
 115                if (!data) {
 116                        err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
 117                                    sha1_to_hex(entries[i].sha1), p->pack_name,
 118                                    (uintmax_t)entries[i].offset);
 119                        break;
 120                }
 121                if (check_sha1_signature(entries[i].sha1, data, size, typename(type))) {
 122                        err = error("packed %s from %s is corrupt",
 123                                    sha1_to_hex(entries[i].sha1), p->pack_name);
 124                        free(data);
 125                        break;
 126                }
 127                free(data);
 128        }
 129        free(entries);
 130
 131        return err;
 132}
 133
 134int verify_pack(struct packed_git *p)
 135{
 136        off_t index_size;
 137        const unsigned char *index_base;
 138        git_SHA_CTX ctx;
 139        unsigned char sha1[20];
 140        int err = 0;
 141        struct pack_window *w_curs = NULL;
 142
 143        if (open_pack_index(p))
 144                return error("packfile %s index not opened", p->pack_name);
 145        index_size = p->index_size;
 146        index_base = p->index_data;
 147
 148        /* Verify SHA1 sum of the index file */
 149        git_SHA1_Init(&ctx);
 150        git_SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
 151        git_SHA1_Final(sha1, &ctx);
 152        if (hashcmp(sha1, index_base + index_size - 20))
 153                err = error("Packfile index for %s SHA1 mismatch",
 154                            p->pack_name);
 155
 156        /* Verify pack file */
 157        err |= verify_packfile(p, &w_curs);
 158        unuse_pack(&w_curs);
 159
 160        return err;
 161}