summaryrefslogtreecommitdiff
path: root/pack-check.c
blob: 08a9fd8dc09056c1b21cb7414f2467cffcdef077 (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
#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 offset = 0, pack_sig = p->pack_size - 20;
	int nr_objects, err, i;
 
	/* 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 -= 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, (unsigned char *)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 = num_packed_objects(p);
	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)
{
	int nr_objects, i;
	unsigned int chain_histogram[MAX_CHAIN];
 
	nr_objects = num_packed_objects(p);
	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 {
			show_pack_info(p);
			printf("%s: ok\n", p->pack_name);
		}
	}
 
	return ret;
}