freshlybakedca.ke
Git fork
1#define DISABLE_SIGN_COMPARE_WARNINGS
2
3#include "git-compat-util.h"
4#include "environment.h"
5#include "hex.h"
6#include "repository.h"
7#include "pack.h"
8#include "progress.h"
9#include "packfile.h"
10#include "object-file.h"
11#include "odb.h"
12
13struct idx_entry {
14 off_t offset;
15 unsigned int nr;
16};
17
18static int compare_entries(const void *e1, const void *e2)
19{
20 const struct idx_entry *entry1 = e1;
21 const struct idx_entry *entry2 = e2;
22 if (entry1->offset < entry2->offset)
23 return -1;
24 if (entry1->offset > entry2->offset)
25 return 1;
26 return 0;
27}
28
29int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
30 off_t offset, off_t len, unsigned int nr)
31{
32 const uint32_t *index_crc;
33 uint32_t data_crc = crc32(0, NULL, 0);
34
35 do {
36 unsigned long avail;
37 void *data = use_pack(p, w_curs, offset, &avail);
38 if (avail > len)
39 avail = len;
40 data_crc = crc32(data_crc, data, avail);
41 offset += avail;
42 len -= avail;
43 } while (len);
44
45 index_crc = p->index_data;
46 index_crc += 2 + 256 + (size_t)p->num_objects * (p->repo->hash_algo->rawsz/4) + nr;
47
48 return data_crc != ntohl(*index_crc);
49}
50
51static int verify_packfile(struct repository *r,
52 struct packed_git *p,
53 struct pack_window **w_curs,
54 verify_fn fn,
55 struct progress *progress, uint32_t base_count)
56
57{
58 off_t index_size = p->index_size;
59 const unsigned char *index_base = p->index_data;
60 struct git_hash_ctx ctx;
61 unsigned char hash[GIT_MAX_RAWSZ], *pack_sig;
62 off_t offset = 0, pack_sig_ofs = 0;
63 uint32_t nr_objects, i;
64 int err = 0;
65 struct idx_entry *entries;
66
67 if (!is_pack_valid(p))
68 return error("packfile %s cannot be accessed", p->pack_name);
69
70 r->hash_algo->init_fn(&ctx);
71 do {
72 unsigned long remaining;
73 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
74 offset += remaining;
75 if (!pack_sig_ofs)
76 pack_sig_ofs = p->pack_size - r->hash_algo->rawsz;
77 if (offset > pack_sig_ofs)
78 remaining -= (unsigned int)(offset - pack_sig_ofs);
79 git_hash_update(&ctx, in, remaining);
80 } while (offset < pack_sig_ofs);
81 git_hash_final(hash, &ctx);
82 pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
83 if (!hasheq(hash, pack_sig, r->hash_algo))
84 err = error("%s pack checksum mismatch",
85 p->pack_name);
86 if (!hasheq(index_base + index_size - r->hash_algo->hexsz, pack_sig,
87 r->hash_algo))
88 err = error("%s pack checksum does not match its index",
89 p->pack_name);
90 unuse_pack(w_curs);
91
92 /* Make sure everything reachable from idx is valid. Since we
93 * have verified that nr_objects matches between idx and pack,
94 * we do not do scan-streaming check on the pack file.
95 */
96 nr_objects = p->num_objects;
97 ALLOC_ARRAY(entries, nr_objects + 1);
98 entries[nr_objects].offset = pack_sig_ofs;
99 /* first sort entries by pack offset, since unpacking them is more efficient that way */
100 for (i = 0; i < nr_objects; i++) {
101 entries[i].offset = nth_packed_object_offset(p, i);
102 entries[i].nr = i;
103 }
104 QSORT(entries, nr_objects, compare_entries);
105
106 for (i = 0; i < nr_objects; i++) {
107 void *data;
108 struct object_id oid;
109 enum object_type type;
110 unsigned long size;
111 off_t curpos;
112 int data_valid;
113
114 if (nth_packed_object_id(&oid, p, entries[i].nr) < 0)
115 BUG("unable to get oid of object %lu from %s",
116 (unsigned long)entries[i].nr, p->pack_name);
117
118 if (p->index_version > 1) {
119 off_t offset = entries[i].offset;
120 off_t len = entries[i+1].offset - offset;
121 unsigned int nr = entries[i].nr;
122 if (check_pack_crc(p, w_curs, offset, len, nr))
123 err = error("index CRC mismatch for object %s "
124 "from %s at offset %"PRIuMAX"",
125 oid_to_hex(&oid),
126 p->pack_name, (uintmax_t)offset);
127 }
128
129 curpos = entries[i].offset;
130 type = unpack_object_header(p, w_curs, &curpos, &size);
131 unuse_pack(w_curs);
132
133 if (type == OBJ_BLOB &&
134 repo_settings_get_big_file_threshold(r) <= size) {
135 /*
136 * Let stream_object_signature() check it with
137 * the streaming interface; no point slurping
138 * the data in-core only to discard.
139 */
140 data = NULL;
141 data_valid = 0;
142 } else {
143 data = unpack_entry(r, p, entries[i].offset, &type, &size);
144 data_valid = 1;
145 }
146
147 if (data_valid && !data)
148 err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
149 oid_to_hex(&oid), p->pack_name,
150 (uintmax_t)entries[i].offset);
151 else if (data && check_object_signature(r, &oid, data, size,
152 type) < 0)
153 err = error("packed %s from %s is corrupt",
154 oid_to_hex(&oid), p->pack_name);
155 else if (!data && stream_object_signature(r, &oid) < 0)
156 err = error("packed %s from %s is corrupt",
157 oid_to_hex(&oid), p->pack_name);
158 else if (fn) {
159 int eaten = 0;
160 err |= fn(&oid, type, size, data, &eaten);
161 if (eaten)
162 data = NULL;
163 }
164 if (((base_count + i) & 1023) == 0)
165 display_progress(progress, base_count + i);
166 free(data);
167
168 }
169 display_progress(progress, base_count + i);
170 free(entries);
171
172 return err;
173}
174
175int verify_pack_index(struct packed_git *p)
176{
177 int err = 0;
178
179 if (open_pack_index(p))
180 return error("packfile %s index not opened", p->pack_name);
181
182 /* Verify SHA1 sum of the index file */
183 if (!hashfile_checksum_valid(p->repo->hash_algo, p->index_data, p->index_size))
184 err = error("Packfile index for %s hash mismatch",
185 p->pack_name);
186 return err;
187}
188
189int verify_pack(struct repository *r, struct packed_git *p, verify_fn fn,
190 struct progress *progress, uint32_t base_count)
191{
192 int err = 0;
193 struct pack_window *w_curs = NULL;
194
195 err |= verify_pack_index(p);
196 if (!p->index_data)
197 return -1;
198
199 err |= verify_packfile(r, p, &w_curs, fn, progress, base_count);
200 unuse_pack(&w_curs);
201
202 return err;
203}