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-rw-r--r--pack-check.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/pack-check.c b/pack-check.c
new file mode 100644
index 0000000000..d04536bbff
--- /dev/null
+++ b/pack-check.c
@@ -0,0 +1,164 @@
+#include "cache.h"
+#include "pack.h"
+
+static int verify_packfile(struct packed_git *p,
+ struct pack_window **w_curs)
+{
+ off_t index_size = p->index_size;
+ const unsigned char *index_base = p->index_data;
+ SHA_CTX ctx;
+ unsigned char sha1[20];
+ off_t offset = 0, pack_sig = p->pack_size - 20;
+ uint32_t nr_objects, i;
+ int err;
+
+ /* Note that the pack header checks are actually performed by
+ * use_pack when it first opens the pack file. If anything
+ * goes wrong during those checks then the call will die out
+ * immediately.
+ */
+
+ SHA1_Init(&ctx);
+ while (offset < pack_sig) {
+ unsigned int remaining;
+ unsigned char *in = use_pack(p, w_curs, offset, &remaining);
+ offset += remaining;
+ if (offset > pack_sig)
+ remaining -= (unsigned int)(offset - pack_sig);
+ SHA1_Update(&ctx, in, remaining);
+ }
+ SHA1_Final(sha1, &ctx);
+ if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
+ return error("Packfile %s SHA1 mismatch with itself",
+ p->pack_name);
+ if (hashcmp(sha1, index_base + index_size - 40))
+ return error("Packfile %s SHA1 mismatch with idx",
+ p->pack_name);
+ unuse_pack(w_curs);
+
+ /* Make sure everything reachable from idx is valid. Since we
+ * have verified that nr_objects matches between idx and pack,
+ * we do not do scan-streaming check on the pack file.
+ */
+ nr_objects = p->num_objects;
+ for (i = 0, err = 0; i < nr_objects; i++) {
+ const unsigned char *sha1;
+ void *data;
+ enum object_type type;
+ unsigned long size;
+ off_t offset;
+
+ sha1 = nth_packed_object_sha1(p, i);
+ if (!sha1)
+ die("internal error pack-check nth-packed-object");
+ offset = find_pack_entry_one(sha1, p);
+ if (!offset)
+ die("internal error pack-check find-pack-entry-one");
+ data = unpack_entry(p, offset, &type, &size);
+ if (!data) {
+ err = error("cannot unpack %s from %s",
+ sha1_to_hex(sha1), p->pack_name);
+ continue;
+ }
+ if (check_sha1_signature(sha1, data, size, typename(type))) {
+ err = error("packed %s from %s is corrupt",
+ sha1_to_hex(sha1), p->pack_name);
+ free(data);
+ continue;
+ }
+ free(data);
+ }
+
+ return err;
+}
+
+
+#define MAX_CHAIN 40
+
+static void show_pack_info(struct packed_git *p)
+{
+ uint32_t nr_objects, i, chain_histogram[MAX_CHAIN];
+
+ nr_objects = p->num_objects;
+ memset(chain_histogram, 0, sizeof(chain_histogram));
+
+ for (i = 0; i < nr_objects; i++) {
+ const unsigned char *sha1;
+ unsigned char base_sha1[20];
+ const char *type;
+ unsigned long size;
+ unsigned long store_size;
+ off_t offset;
+ unsigned int delta_chain_length;
+
+ sha1 = nth_packed_object_sha1(p, i);
+ if (!sha1)
+ die("internal error pack-check nth-packed-object");
+ offset = find_pack_entry_one(sha1, p);
+ if (!offset)
+ die("internal error pack-check find-pack-entry-one");
+
+ type = packed_object_info_detail(p, offset, &size, &store_size,
+ &delta_chain_length,
+ base_sha1);
+ printf("%s ", sha1_to_hex(sha1));
+ if (!delta_chain_length)
+ printf("%-6s %lu %"PRIuMAX"\n",
+ type, size, (uintmax_t)offset);
+ else {
+ printf("%-6s %lu %"PRIuMAX" %u %s\n",
+ type, size, (uintmax_t)offset,
+ delta_chain_length, sha1_to_hex(base_sha1));
+ if (delta_chain_length < MAX_CHAIN)
+ chain_histogram[delta_chain_length]++;
+ else
+ chain_histogram[0]++;
+ }
+ }
+
+ for (i = 0; i < MAX_CHAIN; i++) {
+ if (!chain_histogram[i])
+ continue;
+ printf("chain length %s %d: %d object%s\n",
+ i ? "=" : ">=",
+ i ? i : MAX_CHAIN,
+ chain_histogram[i],
+ 1 < chain_histogram[i] ? "s" : "");
+ }
+}
+
+int verify_pack(struct packed_git *p, int verbose)
+{
+ off_t index_size = p->index_size;
+ const unsigned char *index_base = p->index_data;
+ SHA_CTX ctx;
+ unsigned char sha1[20];
+ int ret;
+
+ ret = 0;
+ /* Verify SHA1 sum of the index file */
+ SHA1_Init(&ctx);
+ SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
+ SHA1_Final(sha1, &ctx);
+ if (hashcmp(sha1, index_base + index_size - 20))
+ ret = error("Packfile index for %s SHA1 mismatch",
+ p->pack_name);
+
+ if (!ret) {
+ /* Verify pack file */
+ struct pack_window *w_curs = NULL;
+ ret = verify_packfile(p, &w_curs);
+ unuse_pack(&w_curs);
+ }
+
+ if (verbose) {
+ if (ret)
+ printf("%s: bad\n", p->pack_name);
+ else {
+ show_pack_info(p);
+ printf("%s: ok\n", p->pack_name);
+ }
+ }
+
+ return ret;
+}