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