receive-pack: use strict mode for unpacking objects
[git] / pack-check.c
1 #include "cache.h"
2 #include "pack.h"
3
4 struct idx_entry
5 {
6         const unsigned char *sha1;
7         off_t                offset;
8 };
9
10 static int compare_entries(const void *e1, const void *e2)
11 {
12         const struct idx_entry *entry1 = e1;
13         const struct idx_entry *entry2 = e2;
14         if (entry1->offset < entry2->offset)
15                 return -1;
16         if (entry1->offset > entry2->offset)
17                 return 1;
18         return 0;
19 }
20
21 static int verify_packfile(struct packed_git *p,
22                 struct pack_window **w_curs)
23 {
24         off_t index_size = p->index_size;
25         const unsigned char *index_base = p->index_data;
26         SHA_CTX ctx;
27         unsigned char sha1[20];
28         off_t offset = 0, pack_sig = p->pack_size - 20;
29         uint32_t nr_objects, i;
30         int err;
31         struct idx_entry *entries;
32
33         /* Note that the pack header checks are actually performed by
34          * use_pack when it first opens the pack file.  If anything
35          * goes wrong during those checks then the call will die out
36          * immediately.
37          */
38
39         SHA1_Init(&ctx);
40         while (offset < pack_sig) {
41                 unsigned int remaining;
42                 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
43                 offset += remaining;
44                 if (offset > pack_sig)
45                         remaining -= (unsigned int)(offset - pack_sig);
46                 SHA1_Update(&ctx, in, remaining);
47         }
48         SHA1_Final(sha1, &ctx);
49         if (hashcmp(sha1, use_pack(p, w_curs, pack_sig, NULL)))
50                 return error("Packfile %s SHA1 mismatch with itself",
51                              p->pack_name);
52         if (hashcmp(sha1, index_base + index_size - 40))
53                 return error("Packfile %s SHA1 mismatch with idx",
54                              p->pack_name);
55         unuse_pack(w_curs);
56
57         /* Make sure everything reachable from idx is valid.  Since we
58          * have verified that nr_objects matches between idx and pack,
59          * we do not do scan-streaming check on the pack file.
60          */
61         nr_objects = p->num_objects;
62         entries = xmalloc(nr_objects * sizeof(*entries));
63         /* first sort entries by pack offset, since unpacking them is more efficient that way */
64         for (i = 0; i < nr_objects; i++) {
65                 entries[i].sha1 = nth_packed_object_sha1(p, i);
66                 if (!entries[i].sha1)
67                         die("internal error pack-check nth-packed-object");
68                 entries[i].offset = find_pack_entry_one(entries[i].sha1, p);
69                 if (!entries[i].offset)
70                         die("internal error pack-check find-pack-entry-one");
71         }
72         qsort(entries, nr_objects, sizeof(*entries), compare_entries);
73
74         for (i = 0, err = 0; i < nr_objects; i++) {
75                 void *data;
76                 enum object_type type;
77                 unsigned long size;
78
79                 data = unpack_entry(p, entries[i].offset, &type, &size);
80                 if (!data) {
81                         err = error("cannot unpack %s from %s",
82                                     sha1_to_hex(entries[i].sha1), p->pack_name);
83                         continue;
84                 }
85                 if (check_sha1_signature(entries[i].sha1, data, size, typename(type))) {
86                         err = error("packed %s from %s is corrupt",
87                                     sha1_to_hex(entries[i].sha1), p->pack_name);
88                         free(data);
89                         continue;
90                 }
91                 free(data);
92         }
93         free(entries);
94
95         return err;
96 }
97
98
99 #define MAX_CHAIN 50
100
101 static void show_pack_info(struct packed_git *p)
102 {
103         uint32_t nr_objects, i, chain_histogram[MAX_CHAIN+1];
104         nr_objects = p->num_objects;
105         memset(chain_histogram, 0, sizeof(chain_histogram));
106
107         for (i = 0; i < nr_objects; i++) {
108                 const unsigned char *sha1;
109                 unsigned char base_sha1[20];
110                 const char *type;
111                 unsigned long size;
112                 unsigned long store_size;
113                 off_t offset;
114                 unsigned int delta_chain_length;
115
116                 sha1 = nth_packed_object_sha1(p, i);
117                 if (!sha1)
118                         die("internal error pack-check nth-packed-object");
119                 offset = find_pack_entry_one(sha1, p);
120                 if (!offset)
121                         die("internal error pack-check find-pack-entry-one");
122
123                 type = packed_object_info_detail(p, offset, &size, &store_size,
124                                                  &delta_chain_length,
125                                                  base_sha1);
126                 printf("%s ", sha1_to_hex(sha1));
127                 if (!delta_chain_length)
128                         printf("%-6s %lu %"PRIuMAX"\n",
129                                type, size, (uintmax_t)offset);
130                 else {
131                         printf("%-6s %lu %"PRIuMAX" %u %s\n",
132                                type, size, (uintmax_t)offset,
133                                delta_chain_length, sha1_to_hex(base_sha1));
134                         if (delta_chain_length <= MAX_CHAIN)
135                                 chain_histogram[delta_chain_length]++;
136                         else
137                                 chain_histogram[0]++;
138                 }
139         }
140
141         for (i = 0; i <= MAX_CHAIN; i++) {
142                 if (!chain_histogram[i])
143                         continue;
144                 printf("chain length = %d: %d object%s\n", i,
145                        chain_histogram[i], chain_histogram[i] > 1 ? "s" : "");
146         }
147         if (chain_histogram[0])
148                 printf("chain length > %d: %d object%s\n", MAX_CHAIN,
149                        chain_histogram[0], chain_histogram[0] > 1 ? "s" : "");
150 }
151
152 int verify_pack(struct packed_git *p, int verbose)
153 {
154         off_t index_size;
155         const unsigned char *index_base;
156         SHA_CTX ctx;
157         unsigned char sha1[20];
158         int ret;
159
160         if (open_pack_index(p))
161                 return error("packfile %s index not opened", p->pack_name);
162         index_size = p->index_size;
163         index_base = p->index_data;
164
165         ret = 0;
166         /* Verify SHA1 sum of the index file */
167         SHA1_Init(&ctx);
168         SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
169         SHA1_Final(sha1, &ctx);
170         if (hashcmp(sha1, index_base + index_size - 20))
171                 ret = error("Packfile index for %s SHA1 mismatch",
172                             p->pack_name);
173
174         if (!ret) {
175                 /* Verify pack file */
176                 struct pack_window *w_curs = NULL;
177                 ret = verify_packfile(p, &w_curs);
178                 unuse_pack(&w_curs);
179         }
180
181         if (verbose) {
182                 if (ret)
183                         printf("%s: bad\n", p->pack_name);
184                 else {
185                         show_pack_info(p);
186                         printf("%s: ok\n", p->pack_name);
187                 }
188         }
189
190         return ret;
191 }