add QSORT
[git/git.git] / pack-check.c
1 #include "cache.h"
2 #include "pack.h"
3 #include "pack-revindex.h"
4 #include "progress.h"
5
6 struct idx_entry {
7 off_t offset;
8 const unsigned char *sha1;
9 unsigned int nr;
10 };
11
12 static 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
23 int 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, NULL, 0);
28
29 do {
30 unsigned long 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
45 static int verify_packfile(struct packed_git *p,
46 struct pack_window **w_curs,
47 verify_fn fn,
48 struct progress *progress, uint32_t base_count)
49
50 {
51 off_t index_size = p->index_size;
52 const unsigned char *index_base = p->index_data;
53 git_SHA_CTX ctx;
54 unsigned char sha1[20], *pack_sig;
55 off_t offset = 0, pack_sig_ofs = 0;
56 uint32_t nr_objects, i;
57 int err = 0;
58 struct idx_entry *entries;
59
60 /* Note that the pack header checks are actually performed by
61 * use_pack when it first opens the pack file. If anything
62 * goes wrong during those checks then the call will die out
63 * immediately.
64 */
65
66 git_SHA1_Init(&ctx);
67 do {
68 unsigned long remaining;
69 unsigned char *in = use_pack(p, w_curs, offset, &remaining);
70 offset += remaining;
71 if (!pack_sig_ofs)
72 pack_sig_ofs = p->pack_size - 20;
73 if (offset > pack_sig_ofs)
74 remaining -= (unsigned int)(offset - pack_sig_ofs);
75 git_SHA1_Update(&ctx, in, remaining);
76 } while (offset < pack_sig_ofs);
77 git_SHA1_Final(sha1, &ctx);
78 pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
79 if (hashcmp(sha1, pack_sig))
80 err = error("%s SHA1 checksum mismatch",
81 p->pack_name);
82 if (hashcmp(index_base + index_size - 40, pack_sig))
83 err = error("%s SHA1 does not match its index",
84 p->pack_name);
85 unuse_pack(w_curs);
86
87 /* Make sure everything reachable from idx is valid. Since we
88 * have verified that nr_objects matches between idx and pack,
89 * we do not do scan-streaming check on the pack file.
90 */
91 nr_objects = p->num_objects;
92 ALLOC_ARRAY(entries, nr_objects + 1);
93 entries[nr_objects].offset = pack_sig_ofs;
94 /* first sort entries by pack offset, since unpacking them is more efficient that way */
95 for (i = 0; i < nr_objects; i++) {
96 entries[i].sha1 = nth_packed_object_sha1(p, i);
97 if (!entries[i].sha1)
98 die("internal error pack-check nth-packed-object");
99 entries[i].offset = nth_packed_object_offset(p, i);
100 entries[i].nr = i;
101 }
102 qsort(entries, nr_objects, sizeof(*entries), compare_entries);
103
104 for (i = 0; i < nr_objects; i++) {
105 void *data;
106 enum object_type type;
107 unsigned long size;
108 off_t curpos;
109 int data_valid;
110
111 if (p->index_version > 1) {
112 off_t offset = entries[i].offset;
113 off_t len = entries[i+1].offset - offset;
114 unsigned int nr = entries[i].nr;
115 if (check_pack_crc(p, w_curs, offset, len, nr))
116 err = error("index CRC mismatch for object %s "
117 "from %s at offset %"PRIuMAX"",
118 sha1_to_hex(entries[i].sha1),
119 p->pack_name, (uintmax_t)offset);
120 }
121
122 curpos = entries[i].offset;
123 type = unpack_object_header(p, w_curs, &curpos, &size);
124 unuse_pack(w_curs);
125
126 if (type == OBJ_BLOB && big_file_threshold <= size) {
127 /*
128 * Let check_sha1_signature() check it with
129 * the streaming interface; no point slurping
130 * the data in-core only to discard.
131 */
132 data = NULL;
133 data_valid = 0;
134 } else {
135 data = unpack_entry(p, entries[i].offset, &type, &size);
136 data_valid = 1;
137 }
138
139 if (data_valid && !data)
140 err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
141 sha1_to_hex(entries[i].sha1), p->pack_name,
142 (uintmax_t)entries[i].offset);
143 else if (check_sha1_signature(entries[i].sha1, data, size, typename(type)))
144 err = error("packed %s from %s is corrupt",
145 sha1_to_hex(entries[i].sha1), p->pack_name);
146 else if (fn) {
147 int eaten = 0;
148 err |= fn(entries[i].sha1, type, size, data, &eaten);
149 if (eaten)
150 data = NULL;
151 }
152 if (((base_count + i) & 1023) == 0)
153 display_progress(progress, base_count + i);
154 free(data);
155
156 }
157 display_progress(progress, base_count + i);
158 free(entries);
159
160 return err;
161 }
162
163 int verify_pack_index(struct packed_git *p)
164 {
165 off_t index_size;
166 const unsigned char *index_base;
167 git_SHA_CTX ctx;
168 unsigned char sha1[20];
169 int err = 0;
170
171 if (open_pack_index(p))
172 return error("packfile %s index not opened", p->pack_name);
173 index_size = p->index_size;
174 index_base = p->index_data;
175
176 /* Verify SHA1 sum of the index file */
177 git_SHA1_Init(&ctx);
178 git_SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
179 git_SHA1_Final(sha1, &ctx);
180 if (hashcmp(sha1, index_base + index_size - 20))
181 err = error("Packfile index for %s SHA1 mismatch",
182 p->pack_name);
183 return err;
184 }
185
186 int verify_pack(struct packed_git *p, verify_fn fn,
187 struct progress *progress, uint32_t base_count)
188 {
189 int err = 0;
190 struct pack_window *w_curs = NULL;
191
192 err |= verify_pack_index(p);
193 if (!p->index_data)
194 return -1;
195
196 err |= verify_packfile(p, &w_curs, fn, progress, base_count);
197 unuse_pack(&w_curs);
198
199 return err;
200 }