pack-check.c

   1 #include "cache.h"
   2 #include "pack.h"
   3
   4 static int verify_packfile(struct packed_git *p,
   5                 struct pack_window **w_curs)
   6 {
   7         off_t index_size = p->index_size;
   8         const unsigned char *index_base = p->index_data;
   9         SHA_CTX ctx;
  10         unsigned char sha1[20];
  11         off_t offset = 0, pack_sig = p->pack_size - 20;
  12         uint32_t nr_objects, i;
  13         int err;
  14
  15         /* Note that the pack header checks are actually performed by
  16          * use_pack when it first opens the pack file.  If anything
  17          * goes wrong during those checks then the call will die out
  18          * immediately.
  19          */
  20
  21         SHA1_Init(&ctx);
  22         while (offset < pack_sig) {
  23                 unsigned int remaining;
  24                 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
  25                 offset += remaining;
  26                 if (offset > pack_sig)
  27                         remaining -= (unsigned int)(offset - pack_sig);
  28                 SHA1_Update(&ctx, in, remaining);
  29         }
  30         SHA1_Final(sha1, &ctx);
  31         if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
  32                 return error("Packfile %s SHA1 mismatch with itself",
  33                              p->pack_name);
  34         if (hashcmp(sha1, index_base + index_size - 40))
  35                 return error("Packfile %s SHA1 mismatch with idx",
  36                              p->pack_name);
  37         unuse_pack(w_curs);
  38
  39         /* Make sure everything reachable from idx is valid.  Since we
  40          * have verified that nr_objects matches between idx and pack,
  41          * we do not do scan-streaming check on the pack file.
  42          */
  43         nr_objects = num_packed_objects(p);
  44         for (i = 0, err = 0; i < nr_objects; i++) {
  45                 const unsigned char *sha1;
  46                 void *data;
  47                 enum object_type type;
  48                 unsigned long size;
  49                 off_t offset;
  50
  51                 sha1 = nth_packed_object_sha1(p, i);
  52                 if (!sha1)
  53                         die("internal error pack-check nth-packed-object");
  54                 offset = find_pack_entry_one(sha1, p);
  55                 if (!offset)
  56                         die("internal error pack-check find-pack-entry-one");
  57                 data = unpack_entry(p, offset, &type, &size);
  58                 if (!data) {
  59                         err = error("cannot unpack %s from %s",
  60                                     sha1_to_hex(sha1), p->pack_name);
  61                         continue;
  62                 }
  63                 if (check_sha1_signature(sha1, data, size, typename(type))) {
  64                         err = error("packed %s from %s is corrupt",
  65                                     sha1_to_hex(sha1), p->pack_name);
  66                         free(data);
  67                         continue;
  68                 }
  69                 free(data);
  70         }
  71
  72         return err;
  73 }
  74
  75
  76 #define MAX_CHAIN 40
  77
  78 static void show_pack_info(struct packed_git *p)
  79 {
  80         uint32_t nr_objects, i, chain_histogram[MAX_CHAIN];
  81
  82         nr_objects = num_packed_objects(p);
  83         memset(chain_histogram, 0, sizeof(chain_histogram));
  84
  85         for (i = 0; i < nr_objects; i++) {
  86                 const unsigned char *sha1;
  87                 unsigned char base_sha1[20];
  88                 const char *type;
  89                 unsigned long size;
  90                 unsigned long store_size;
  91                 off_t offset;
  92                 unsigned int delta_chain_length;
  93
  94                 sha1 = nth_packed_object_sha1(p, i);
  95                 if (!sha1)
  96                         die("internal error pack-check nth-packed-object");
  97                 offset = find_pack_entry_one(sha1, p);
  98                 if (!offset)
  99                         die("internal error pack-check find-pack-entry-one");
 100
 101                 type = packed_object_info_detail(p, offset, &size, &store_size,
 102                                                  &delta_chain_length,
 103                                                  base_sha1);
 104                 printf("%s ", sha1_to_hex(sha1));
 105                 if (!delta_chain_length)
 106                         printf("%-6s %lu %"PRIuMAX"\n",
 107                                type, size, (uintmax_t)offset);
 108                 else {
 109                         printf("%-6s %lu %"PRIuMAX" %u %s\n",
 110                                type, size, (uintmax_t)offset,
 111                                delta_chain_length, sha1_to_hex(base_sha1));
 112                         if (delta_chain_length < MAX_CHAIN)
 113                                 chain_histogram[delta_chain_length]++;
 114                         else
 115                                 chain_histogram[0]++;
 116                 }
 117         }
 118
 119         for (i = 0; i < MAX_CHAIN; i++) {
 120                 if (!chain_histogram[i])
 121                         continue;
 122                 printf("chain length %s %d: %d object%s\n",
 123                        i ? "=" : ">=",
 124                        i ? i : MAX_CHAIN,
 125                        chain_histogram[i],
 126                        1 < chain_histogram[i] ? "s" : "");
 127         }
 128 }
 129
 130 int verify_pack(struct packed_git *p, int verbose)
 131 {
 132         off_t index_size = p->index_size;
 133         const unsigned char *index_base = p->index_data;
 134         SHA_CTX ctx;
 135         unsigned char sha1[20];
 136         int ret;
 137
 138         ret = 0;
 139         /* Verify SHA1 sum of the index file */
 140         SHA1_Init(&ctx);
 141         SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
 142         SHA1_Final(sha1, &ctx);
 143         if (hashcmp(sha1, index_base + index_size - 20))
 144                 ret = error("Packfile index for %s SHA1 mismatch",
 145                             p->pack_name);
 146
 147         if (!ret) {
 148                 /* Verify pack file */
 149                 struct pack_window *w_curs = NULL;
 150                 ret = verify_packfile(p, &w_curs);
 151                 unuse_pack(&w_curs);
 152         }
 153
 154         if (verbose) {
 155                 if (ret)
 156                         printf("%s: bad\n", p->pack_name);
 157                 else {
 158                         show_pack_info(p);
 159                         printf("%s: ok\n", p->pack_name);
 160                 }
 161         }
 162
 163         return ret;
 164 }