summaryrefslogtreecommitdiff
path: root/pack-check.c
blob: 972916f4064386e033ada16e6badc3a174ef5b23 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
#include "cache.h"
#include "pack.h"
 
static int verify_packfile(struct packed_git *p,
		struct pack_window **w_curs)
{
	unsigned long index_size = p->index_size;
	void *index_base = p->index_base;
	SHA_CTX ctx;
	unsigned char sha1[20];
	unsigned long pack_size = p->pack_size;
	void *pack_base;
	struct pack_header *hdr;
	int nr_objects, err, i;
 
	/* Header consistency check */
	pack_base = use_pack(p, w_curs, 0, NULL);
	hdr = (struct pack_header*)pack_base;
	if (hdr->hdr_signature != htonl(PACK_SIGNATURE))
		return error("Packfile %s signature mismatch", p->pack_name);
	if (!pack_version_ok(hdr->hdr_version))
		return error("Packfile version %d unsupported",
			     ntohl(hdr->hdr_version));
	nr_objects = ntohl(hdr->hdr_entries);
	if (num_packed_objects(p) != nr_objects)
		return error("Packfile claims to have %d objects, "
			     "while idx size expects %d", nr_objects,
			     num_packed_objects(p));
 
	SHA1_Init(&ctx);
	SHA1_Update(&ctx, pack_base, pack_size - 20);
	SHA1_Final(sha1, &ctx);
	if (hashcmp(sha1, (unsigned char *)pack_base + pack_size - 20))
		return error("Packfile %s SHA1 mismatch with itself",
			     p->pack_name);
	if (hashcmp(sha1, (unsigned char *)index_base + index_size - 40))
		return error("Packfile %s SHA1 mismatch with idx",
			     p->pack_name);
 
	/* 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.
	 */
	for (i = err = 0; i < nr_objects; i++) {
		unsigned char sha1[20];
		void *data;
		char type[20];
		unsigned long size, offset;
 
		if (nth_packed_object_sha1(p, i, 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, 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,
		struct pack_window **w_curs)
{
	struct pack_header *hdr;
	int nr_objects, i;
	unsigned int chain_histogram[MAX_CHAIN];
 
	hdr = (struct pack_header*)use_pack(p, w_curs, 0, NULL);
	nr_objects = ntohl(hdr->hdr_entries);
	memset(chain_histogram, 0, sizeof(chain_histogram));
 
	for (i = 0; i < nr_objects; i++) {
		unsigned char sha1[20], base_sha1[20];
		char type[20];
		unsigned long size;
		unsigned long store_size;
		unsigned long offset;
		unsigned int delta_chain_length;
 
		if (nth_packed_object_sha1(p, i, 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");
 
		packed_object_info_detail(p, offset, type, &size, &store_size,
					  &delta_chain_length,
					  base_sha1);
		printf("%s ", sha1_to_hex(sha1));
		if (!delta_chain_length)
			printf("%-6s %lu %lu\n", type, size, offset);
		else {
			printf("%-6s %lu %lu %u %s\n", type, size, 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)
{
	unsigned long index_size = p->index_size;
	void *index_base = p->index_base;
	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, index_size - 20);
	SHA1_Final(sha1, &ctx);
	if (hashcmp(sha1, (unsigned char *)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 {
			struct pack_window *w_curs = NULL;
			show_pack_info(p, &w_curs);
			unuse_pack(&w_curs);
			printf("%s: ok\n", p->pack_name);
		}
	}
 
	return ret;
}