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                 unsigned char sha1[20];
  46                 void *data;
  47                 enum object_type type;
  48                 unsigned long size;
  49                 off_t offset;
  50
  51                 if (nth_packed_object_sha1(p, i, sha1))
  52                         die("internal error pack-check nth-packed-object");
  53                 offset = find_pack_entry_one(sha1, p);
  54                 if (!offset)
  55                         die("internal error pack-check find-pack-entry-one");
  56                 data = unpack_entry(p, offset, &type, &size);
  57                 if (!data) {
  58                         err = error("cannot unpack %s from %s",
  59                                     sha1_to_hex(sha1), p->pack_name);
  60                         continue;
  61                 }
  62                 if (check_sha1_signature(sha1, data, size, typename(type))) {
  63                         err = error("packed %s from %s is corrupt",
  64                                     sha1_to_hex(sha1), p->pack_name);
  65                         free(data);
  66                         continue;
  67                 }
  68                 free(data);
  69         }
  70
  71         return err;
  72 }
  73
  74
  75 #define MAX_CHAIN 40
  76
  77 static void show_pack_info(struct packed_git *p)
  78 {
  79         uint32_t nr_objects, i, chain_histogram[MAX_CHAIN];
  80
  81         nr_objects = num_packed_objects(p);
  82         memset(chain_histogram, 0, sizeof(chain_histogram));
  83
  84         for (i = 0; i < nr_objects; i++) {
  85                 unsigned char sha1[20], base_sha1[20];
  86                 const char *type;
  87                 unsigned long size;
  88                 unsigned long store_size;
  89                 off_t offset;
  90                 unsigned int delta_chain_length;
  91
  92                 if (nth_packed_object_sha1(p, i, sha1))
  93                         die("internal error pack-check nth-packed-object");
  94                 offset = find_pack_entry_one(sha1, p);
  95                 if (!offset)
  96                         die("internal error pack-check find-pack-entry-one");
  97
  98                 type = packed_object_info_detail(p, offset, &size, &store_size,
  99                                                  &delta_chain_length,
 100                                                  base_sha1);
 101                 printf("%s ", sha1_to_hex(sha1));
 102                 if (!delta_chain_length)
 103                         printf("%-6s %lu %"PRIuMAX"\n",
 104                                type, size, (uintmax_t)offset);
 105                 else {
 106                         printf("%-6s %lu %"PRIuMAX" %u %s\n",
 107                                type, size, (uintmax_t)offset,
 108                                delta_chain_length, sha1_to_hex(base_sha1));
 109                         if (delta_chain_length < MAX_CHAIN)
 110                                 chain_histogram[delta_chain_length]++;
 111                         else
 112                                 chain_histogram[0]++;
 113                 }
 114         }
 115
 116         for (i = 0; i < MAX_CHAIN; i++) {
 117                 if (!chain_histogram[i])
 118                         continue;
 119                 printf("chain length %s %d: %d object%s\n",
 120                        i ? "=" : ">=",
 121                        i ? i : MAX_CHAIN,
 122                        chain_histogram[i],
 123                        1 < chain_histogram[i] ? "s" : "");
 124         }
 125 }
 126
 127 int verify_pack(struct packed_git *p, int verbose)
 128 {
 129         off_t index_size = p->index_size;
 130         const unsigned char *index_base = p->index_data;
 131         SHA_CTX ctx;
 132         unsigned char sha1[20];
 133         int ret;
 134
 135         ret = 0;
 136         /* Verify SHA1 sum of the index file */
 137         SHA1_Init(&ctx);
 138         SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
 139         SHA1_Final(sha1, &ctx);
 140         if (hashcmp(sha1, index_base + index_size - 20))
 141                 ret = error("Packfile index for %s SHA1 mismatch",
 142                             p->pack_name);
 143
 144         if (!ret) {
 145                 /* Verify pack file */
 146                 struct pack_window *w_curs = NULL;
 147                 ret = verify_packfile(p, &w_curs);
 148                 unuse_pack(&w_curs);
 149         }
 150
 151         if (verbose) {
 152                 if (ret)
 153                         printf("%s: bad\n", p->pack_name);
 154                 else {
 155                         show_pack_info(p);
 156                         printf("%s: ok\n", p->pack_name);
 157                 }
 158         }
 159
 160         return ret;
 161 }