pack-check.c

   1 #include "cache.h"
   2 #include "pack.h"
   3
   4 static int verify_packfile(struct packed_git *p)
   5 {
   6         unsigned long index_size = p->index_size;
   7         void *index_base = p->index_base;
   8         SHA_CTX ctx;
   9         unsigned char sha1[20];
  10         unsigned long pack_size = p->pack_size;
  11         void *pack_base;
  12         struct pack_header *hdr;
  13         int nr_objects, err, i;
  14
  15         /* Header consistency check */
  16         hdr = p->pack_base;
  17         if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
  18                 return error("Packfile %s signature mismatch", p->pack_name);
  19         if (!pack_version_ok(hdr->hdr_version))
  20                 return error("Packfile version %d unsupported",
  21                              ntohl(hdr->hdr_version));
  22         nr_objects = ntohl(hdr->hdr_entries);
  23         if (num_packed_objects(p) != nr_objects)
  24                 return error("Packfile claims to have %d objects, "
  25                              "while idx size expects %d", nr_objects,
  26                              num_packed_objects(p));
  27
  28         SHA1_Init(&ctx);
  29         pack_base = p->pack_base;
  30         SHA1_Update(&ctx, pack_base, pack_size - 20);
  31         SHA1_Final(sha1, &ctx);
  32         if (memcmp(sha1, (char *) pack_base + pack_size - 20, 20))
  33                 return error("Packfile %s SHA1 mismatch with itself",
  34                              p->pack_name);
  35         if (memcmp(sha1, (char *) index_base + index_size - 40, 20))
  36                 return error("Packfile %s SHA1 mismatch with idx",
  37                              p->pack_name);
  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         for (i = err = 0; i < nr_objects; i++) {
  44                 unsigned char sha1[20];
  45                 struct pack_entry e;
  46                 void *data;
  47                 char type[20];
  48                 unsigned long size;
  49
  50                 if (nth_packed_object_sha1(p, i, sha1))
  51                         die("internal error pack-check nth-packed-object");
  52                 if (!find_pack_entry_one(sha1, &e, p))
  53                         die("internal error pack-check find-pack-entry-one");
  54                 data = unpack_entry_gently(&e, type, &size);
  55                 if (!data) {
  56                         err = error("cannot unpack %s from %s",
  57                                     sha1_to_hex(sha1), p->pack_name);
  58                         continue;
  59                 }
  60                 if (check_sha1_signature(sha1, data, size, type)) {
  61                         err = error("packed %s from %s is corrupt",
  62                                     sha1_to_hex(sha1), p->pack_name);
  63                         free(data);
  64                         continue;
  65                 }
  66                 free(data);
  67         }
  68
  69         return err;
  70 }
  71
  72
  73 #define MAX_CHAIN 40
  74
  75 static void show_pack_info(struct packed_git *p)
  76 {
  77         struct pack_header *hdr;
  78         int nr_objects, i;
  79         unsigned int chain_histogram[MAX_CHAIN];
  80
  81         hdr = p->pack_base;
  82         nr_objects = ntohl(hdr->hdr_entries);
  83         memset(chain_histogram, 0, sizeof(chain_histogram));
  84
  85         for (i = 0; i < nr_objects; i++) {
  86                 unsigned char sha1[20], base_sha1[20];
  87                 struct pack_entry e;
  88                 char type[20];
  89                 unsigned long size;
  90                 unsigned long store_size;
  91                 unsigned int delta_chain_length;
  92
  93                 if (nth_packed_object_sha1(p, i, sha1))
  94                         die("internal error pack-check nth-packed-object");
  95                 if (!find_pack_entry_one(sha1, &e, p))
  96                         die("internal error pack-check find-pack-entry-one");
  97
  98                 packed_object_info_detail(&e, type, &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 %u\n", type, size, e.offset);
 104                 else {
 105                         printf("%-6s %lu %u %u %s\n", type, size, e.offset,
 106                                delta_chain_length, sha1_to_hex(base_sha1));
 107                         if (delta_chain_length < MAX_CHAIN)
 108                                 chain_histogram[delta_chain_length]++;
 109                         else
 110                                 chain_histogram[0]++;
 111                 }
 112         }
 113
 114         for (i = 0; i < MAX_CHAIN; i++) {
 115                 if (!chain_histogram[i])
 116                         continue;
 117                 printf("chain length %s %d: %d object%s\n",
 118                        i ? "=" : ">=",
 119                        i ? i : MAX_CHAIN,
 120                        chain_histogram[i],
 121                        1 < chain_histogram[i] ? "s" : "");
 122         }
 123 }
 124
 125 int verify_pack(struct packed_git *p, int verbose)
 126 {
 127         unsigned long index_size = p->index_size;
 128         void *index_base = p->index_base;
 129         SHA_CTX ctx;
 130         unsigned char sha1[20];
 131         int ret;
 132
 133         ret = 0;
 134         /* Verify SHA1 sum of the index file */
 135         SHA1_Init(&ctx);
 136         SHA1_Update(&ctx, index_base, index_size - 20);
 137         SHA1_Final(sha1, &ctx);
 138         if (memcmp(sha1, (char *) index_base + index_size - 20, 20))
 139                 ret = error("Packfile index for %s SHA1 mismatch",
 140                             p->pack_name);
 141
 142         if (!ret) {
 143                 /* Verify pack file */
 144                 use_packed_git(p);
 145                 ret = verify_packfile(p);
 146                 unuse_packed_git(p);
 147         }
 148
 149         if (verbose) {
 150                 if (ret)
 151                         printf("%s: bad\n", p->pack_name);
 152                 else {
 153                         use_packed_git(p);
 154                         show_pack_info(p);
 155                         unuse_packed_git(p);
 156                         printf("%s: ok\n", p->pack_name);
 157                 }
 158         }
 159
 160         return ret;
 161 }