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 = p->num_objects;
  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 50
  77
  78 static void show_pack_info(struct packed_git *p)
  79 {
  80         uint32_t nr_objects, i, chain_histogram[MAX_CHAIN+1];
  81         nr_objects = p->num_objects;
  82         memset(chain_histogram, 0, sizeof(chain_histogram));
  83
  84         for (i = 0; i < nr_objects; i++) {
  85                 const unsigned char *sha1;
  86                 unsigned char base_sha1[20];
  87                 const char *type;
  88                 unsigned long size;
  89                 unsigned long store_size;
  90                 off_t offset;
  91                 unsigned int delta_chain_length;
  92
  93                 sha1 = nth_packed_object_sha1(p, i);
  94                 if (!sha1)
  95                         die("internal error pack-check nth-packed-object");
  96                 offset = find_pack_entry_one(sha1, p);
  97                 if (!offset)
  98                         die("internal error pack-check find-pack-entry-one");
  99
 100                 type = packed_object_info_detail(p, offset, &size, &store_size,
 101                                                  &delta_chain_length,
 102                                                  base_sha1);
 103                 printf("%s ", sha1_to_hex(sha1));
 104                 if (!delta_chain_length)
 105                         printf("%-6s %lu %"PRIuMAX"\n",
 106                                type, size, (uintmax_t)offset);
 107                 else {
 108                         printf("%-6s %lu %"PRIuMAX" %u %s\n",
 109                                type, size, (uintmax_t)offset,
 110                                delta_chain_length, sha1_to_hex(base_sha1));
 111                         if (delta_chain_length <= MAX_CHAIN)
 112                                 chain_histogram[delta_chain_length]++;
 113                         else
 114                                 chain_histogram[0]++;
 115                 }
 116         }
 117
 118         for (i = 0; i <= MAX_CHAIN; i++) {
 119                 if (!chain_histogram[i])
 120                         continue;
 121                 printf("chain length = %d: %d object%s\n", i,
 122                        chain_histogram[i], chain_histogram[i] > 1 ? "s" : "");
 123         }
 124         if (chain_histogram[0])
 125                 printf("chain length > %d: %d object%s\n", MAX_CHAIN,
 126                        chain_histogram[0], chain_histogram[0] > 1 ? "s" : "");
 127 }
 128
 129 int verify_pack(struct packed_git *p, int verbose)
 130 {
 131         off_t index_size = p->index_size;
 132         const unsigned char *index_base = p->index_data;
 133         SHA_CTX ctx;
 134         unsigned char sha1[20];
 135         int ret;
 136
 137         ret = 0;
 138         /* Verify SHA1 sum of the index file */
 139         SHA1_Init(&ctx);
 140         SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
 141         SHA1_Final(sha1, &ctx);
 142         if (hashcmp(sha1, index_base + index_size - 20))
 143                 ret = error("Packfile index for %s SHA1 mismatch",
 144                             p->pack_name);
 145
 146         if (!ret) {
 147                 /* Verify pack file */
 148                 struct pack_window *w_curs = NULL;
 149                 ret = verify_packfile(p, &w_curs);
 150                 unuse_pack(&w_curs);
 151         }
 152
 153         if (verbose) {
 154                 if (ret)
 155                         printf("%s: bad\n", p->pack_name);
 156                 else {
 157                         show_pack_info(p);
 158                         printf("%s: ok\n", p->pack_name);
 159                 }
 160         }
 161
 162         return ret;
 163 }