compat: make gcc bswap an inline function
[git/git.git] / pack-check.c
CommitLineData
f9253394
JH
1#include "cache.h"
2#include "pack.h"
70f5d5d3 3#include "pack-revindex.h"
f9253394 4
3af51928
AJ
5struct idx_entry
6{
3af51928 7 off_t offset;
c41a4a94
NP
8 const unsigned char *sha1;
9 unsigned int nr;
3af51928
AJ
10};
11
12static int compare_entries(const void *e1, const void *e2)
13{
14 const struct idx_entry *entry1 = e1;
15 const struct idx_entry *entry2 = e2;
16 if (entry1->offset < entry2->offset)
17 return -1;
18 if (entry1->offset > entry2->offset)
19 return 1;
20 return 0;
21}
22
c41a4a94
NP
23int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
24 off_t offset, off_t len, unsigned int nr)
25{
26 const uint32_t *index_crc;
27 uint32_t data_crc = crc32(0, Z_NULL, 0);
28
29 do {
30 unsigned int avail;
31 void *data = use_pack(p, w_curs, offset, &avail);
32 if (avail > len)
33 avail = len;
34 data_crc = crc32(data_crc, data, avail);
35 offset += avail;
36 len -= avail;
37 } while (len);
38
39 index_crc = p->index_data;
40 index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
41
42 return data_crc != ntohl(*index_crc);
43}
44
03e79c88
SP
45static int verify_packfile(struct packed_git *p,
46 struct pack_window **w_curs)
f9253394 47{
c4001d92 48 off_t index_size = p->index_size;
42873078 49 const unsigned char *index_base = p->index_data;
9126f009 50 git_SHA_CTX ctx;
62413604 51 unsigned char sha1[20], *pack_sig;
4277c670 52 off_t offset = 0, pack_sig_ofs = 0;
326bf396 53 uint32_t nr_objects, i;
62413604 54 int err = 0;
3af51928 55 struct idx_entry *entries;
f9253394 56
079afb18
SP
57 /* Note that the pack header checks are actually performed by
58 * use_pack when it first opens the pack file. If anything
59 * goes wrong during those checks then the call will die out
60 * immediately.
61 */
f9253394 62
9126f009 63 git_SHA1_Init(&ctx);
4277c670 64 do {
079afb18
SP
65 unsigned int remaining;
66 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
67 offset += remaining;
4277c670
MH
68 if (!pack_sig_ofs)
69 pack_sig_ofs = p->pack_size - 20;
62413604
NP
70 if (offset > pack_sig_ofs)
71 remaining -= (unsigned int)(offset - pack_sig_ofs);
9126f009 72 git_SHA1_Update(&ctx, in, remaining);
4277c670 73 } while (offset < pack_sig_ofs);
9126f009 74 git_SHA1_Final(sha1, &ctx);
62413604
NP
75 pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
76 if (hashcmp(sha1, pack_sig))
77 err = error("%s SHA1 checksum mismatch",
78 p->pack_name);
79 if (hashcmp(index_base + index_size - 40, pack_sig))
22e5e58a 80 err = error("%s SHA1 does not match its index",
62413604 81 p->pack_name);
079afb18 82 unuse_pack(w_curs);
f3bf9224
JH
83
84 /* Make sure everything reachable from idx is valid. Since we
85 * have verified that nr_objects matches between idx and pack,
86 * we do not do scan-streaming check on the pack file.
87 */
57059091 88 nr_objects = p->num_objects;
c41a4a94
NP
89 entries = xmalloc((nr_objects + 1) * sizeof(*entries));
90 entries[nr_objects].offset = pack_sig_ofs;
3af51928
AJ
91 /* first sort entries by pack offset, since unpacking them is more efficient that way */
92 for (i = 0; i < nr_objects; i++) {
93 entries[i].sha1 = nth_packed_object_sha1(p, i);
94 if (!entries[i].sha1)
95 die("internal error pack-check nth-packed-object");
99093238 96 entries[i].offset = nth_packed_object_offset(p, i);
c41a4a94 97 entries[i].nr = i;
3af51928
AJ
98 }
99 qsort(entries, nr_objects, sizeof(*entries), compare_entries);
100
62413604 101 for (i = 0; i < nr_objects; i++) {
f3bf9224 102 void *data;
21666f1a 103 enum object_type type;
c4001d92 104 unsigned long size;
f3bf9224 105
c41a4a94
NP
106 if (p->index_version > 1) {
107 off_t offset = entries[i].offset;
108 off_t len = entries[i+1].offset - offset;
109 unsigned int nr = entries[i].nr;
110 if (check_pack_crc(p, w_curs, offset, len, nr))
111 err = error("index CRC mismatch for object %s "
112 "from %s at offset %"PRIuMAX"",
113 sha1_to_hex(entries[i].sha1),
114 p->pack_name, (uintmax_t)offset);
115 }
3af51928 116 data = unpack_entry(p, entries[i].offset, &type, &size);
f3bf9224 117 if (!data) {
62413604
NP
118 err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
119 sha1_to_hex(entries[i].sha1), p->pack_name,
120 (uintmax_t)entries[i].offset);
121 break;
f3bf9224 122 }
3af51928 123 if (check_sha1_signature(entries[i].sha1, data, size, typename(type))) {
1038f0c0 124 err = error("packed %s from %s is corrupt",
3af51928 125 sha1_to_hex(entries[i].sha1), p->pack_name);
f3bf9224 126 free(data);
62413604 127 break;
f3bf9224
JH
128 }
129 free(data);
130 }
3af51928 131 free(entries);
f3bf9224
JH
132
133 return err;
f9253394
JH
134}
135
9b0aa728 136int verify_pack_index(struct packed_git *p)
f9253394 137{
d079837e
SP
138 off_t index_size;
139 const unsigned char *index_base;
9126f009 140 git_SHA_CTX ctx;
f9253394 141 unsigned char sha1[20];
62413604 142 int err = 0;
f9253394 143
d079837e
SP
144 if (open_pack_index(p))
145 return error("packfile %s index not opened", p->pack_name);
146 index_size = p->index_size;
147 index_base = p->index_data;
148
f9253394 149 /* Verify SHA1 sum of the index file */
9126f009
NP
150 git_SHA1_Init(&ctx);
151 git_SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
152 git_SHA1_Final(sha1, &ctx);
42873078 153 if (hashcmp(sha1, index_base + index_size - 20))
62413604 154 err = error("Packfile index for %s SHA1 mismatch",
f3bf9224 155 p->pack_name);
9b0aa728
SP
156 return err;
157}
158
159int verify_pack(struct packed_git *p)
160{
161 int err = 0;
162 struct pack_window *w_curs = NULL;
163
164 err |= verify_pack_index(p);
165 if (!p->index_data)
166 return -1;
f3bf9224 167
62413604
NP
168 err |= verify_packfile(p, &w_curs);
169 unuse_pack(&w_curs);
f3bf9224 170
62413604 171 return err;
f9253394 172}