Merge branch 'esr/maint-doc-fast-import'
[git.git] / pack-check.c
blob63a595c45c961fce54cca95ab6e09e3336f0bb8e
1 #include "cache.h"
2 #include "pack.h"
3 #include "pack-revindex.h"
4 #include "progress.h"
6 struct idx_entry {
7 off_t offset;
8 const unsigned char *sha1;
9 unsigned int nr;
12 static int compare_entries(const void *e1, const void *e2)
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;
23 int check_pack_crc(struct packed_git *p, struct pack_window **w_curs,
24 off_t offset, off_t len, unsigned int nr)
26 const uint32_t *index_crc;
27 uint32_t data_crc = crc32(0, NULL, 0);
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);
39 index_crc = p->index_data;
40 index_crc += 2 + 256 + p->num_objects * (20/4) + nr;
42 return data_crc != ntohl(*index_crc);
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)
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;
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.
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);
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.
91 nr_objects = p->num_objects;
92 entries = xmalloc((nr_objects + 1) * sizeof(*entries));
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;
102 qsort(entries, nr_objects, sizeof(*entries), compare_entries);
104 for (i = 0; i < nr_objects; i++) {
105 void *data;
106 enum object_type type;
107 unsigned long size;
109 if (p->index_version > 1) {
110 off_t offset = entries[i].offset;
111 off_t len = entries[i+1].offset - offset;
112 unsigned int nr = entries[i].nr;
113 if (check_pack_crc(p, w_curs, offset, len, nr))
114 err = error("index CRC mismatch for object %s "
115 "from %s at offset %"PRIuMAX"",
116 sha1_to_hex(entries[i].sha1),
117 p->pack_name, (uintmax_t)offset);
119 data = unpack_entry(p, entries[i].offset, &type, &size);
120 if (!data)
121 err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
122 sha1_to_hex(entries[i].sha1), p->pack_name,
123 (uintmax_t)entries[i].offset);
124 else if (check_sha1_signature(entries[i].sha1, data, size, typename(type)))
125 err = error("packed %s from %s is corrupt",
126 sha1_to_hex(entries[i].sha1), p->pack_name);
127 else if (fn) {
128 int eaten = 0;
129 fn(entries[i].sha1, type, size, data, &eaten);
130 if (eaten)
131 data = NULL;
133 if (((base_count + i) & 1023) == 0)
134 display_progress(progress, base_count + i);
135 free(data);
138 display_progress(progress, base_count + i);
139 free(entries);
141 return err;
144 int verify_pack_index(struct packed_git *p)
146 off_t index_size;
147 const unsigned char *index_base;
148 git_SHA_CTX ctx;
149 unsigned char sha1[20];
150 int err = 0;
152 if (open_pack_index(p))
153 return error("packfile %s index not opened", p->pack_name);
154 index_size = p->index_size;
155 index_base = p->index_data;
157 /* Verify SHA1 sum of the index file */
158 git_SHA1_Init(&ctx);
159 git_SHA1_Update(&ctx, index_base, (unsigned int)(index_size - 20));
160 git_SHA1_Final(sha1, &ctx);
161 if (hashcmp(sha1, index_base + index_size - 20))
162 err = error("Packfile index for %s SHA1 mismatch",
163 p->pack_name);
164 return err;
167 int verify_pack(struct packed_git *p, verify_fn fn,
168 struct progress *progress, uint32_t base_count)
170 int err = 0;
171 struct pack_window *w_curs = NULL;
173 err |= verify_pack_index(p);
174 if (!p->index_data)
175 return -1;
177 err |= verify_packfile(p, &w_curs, fn, progress, base_count);
178 unuse_pack(&w_curs);
180 return err;