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