Merge branch 'nd/parse-options-aliases'
[git] / pack-check.c
1 #include "cache.h"
2 #include "repository.h"
3 #include "pack.h"
4 #include "pack-revindex.h"
5 #include "progress.h"
6 #include "packfile.h"
7 #include "object-store.h"
8
9 struct idx_entry {
10         off_t                offset;
11         union idx_entry_object {
12                 const unsigned char *hash;
13                 struct object_id *oid;
14         } oid;
15         unsigned int nr;
16 };
17
18 static 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
29 int 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 + p->num_objects * (the_hash_algo->rawsz/4) + nr;
47
48         return data_crc != ntohl(*index_crc);
49 }
50
51 static 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         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         the_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 - the_hash_algo->rawsz;
77                 if (offset > pack_sig_ofs)
78                         remaining -= (unsigned int)(offset - pack_sig_ofs);
79                 the_hash_algo->update_fn(&ctx, in, remaining);
80         } while (offset < pack_sig_ofs);
81         the_hash_algo->final_fn(hash, &ctx);
82         pack_sig = use_pack(p, w_curs, pack_sig_ofs, NULL);
83         if (!hasheq(hash, pack_sig))
84                 err = error("%s pack checksum mismatch",
85                             p->pack_name);
86         if (!hasheq(index_base + index_size - the_hash_algo->hexsz, pack_sig))
87                 err = error("%s pack checksum does not match its index",
88                             p->pack_name);
89         unuse_pack(w_curs);
90
91         /* Make sure everything reachable from idx is valid.  Since we
92          * have verified that nr_objects matches between idx and pack,
93          * we do not do scan-streaming check on the pack file.
94          */
95         nr_objects = p->num_objects;
96         ALLOC_ARRAY(entries, nr_objects + 1);
97         entries[nr_objects].offset = pack_sig_ofs;
98         /* first sort entries by pack offset, since unpacking them is more efficient that way */
99         for (i = 0; i < nr_objects; i++) {
100                 entries[i].oid.hash = nth_packed_object_sha1(p, i);
101                 if (!entries[i].oid.hash)
102                         die("internal error pack-check nth-packed-object");
103                 entries[i].offset = nth_packed_object_offset(p, i);
104                 entries[i].nr = i;
105         }
106         QSORT(entries, nr_objects, compare_entries);
107
108         for (i = 0; i < nr_objects; i++) {
109                 void *data;
110                 enum object_type type;
111                 unsigned long size;
112                 off_t curpos;
113                 int data_valid;
114
115                 if (p->index_version > 1) {
116                         off_t offset = entries[i].offset;
117                         off_t len = entries[i+1].offset - offset;
118                         unsigned int nr = entries[i].nr;
119                         if (check_pack_crc(p, w_curs, offset, len, nr))
120                                 err = error("index CRC mismatch for object %s "
121                                             "from %s at offset %"PRIuMAX"",
122                                             oid_to_hex(entries[i].oid.oid),
123                                             p->pack_name, (uintmax_t)offset);
124                 }
125
126                 curpos = entries[i].offset;
127                 type = unpack_object_header(p, w_curs, &curpos, &size);
128                 unuse_pack(w_curs);
129
130                 if (type == OBJ_BLOB && big_file_threshold <= size) {
131                         /*
132                          * Let check_object_signature() check it with
133                          * the streaming interface; no point slurping
134                          * the data in-core only to discard.
135                          */
136                         data = NULL;
137                         data_valid = 0;
138                 } else {
139                         data = unpack_entry(r, p, entries[i].offset, &type, &size);
140                         data_valid = 1;
141                 }
142
143                 if (data_valid && !data)
144                         err = error("cannot unpack %s from %s at offset %"PRIuMAX"",
145                                     oid_to_hex(entries[i].oid.oid), p->pack_name,
146                                     (uintmax_t)entries[i].offset);
147                 else if (check_object_signature(entries[i].oid.oid, data, size, type_name(type)))
148                         err = error("packed %s from %s is corrupt",
149                                     oid_to_hex(entries[i].oid.oid), p->pack_name);
150                 else if (fn) {
151                         int eaten = 0;
152                         err |= fn(entries[i].oid.oid, type, size, data, &eaten);
153                         if (eaten)
154                                 data = NULL;
155                 }
156                 if (((base_count + i) & 1023) == 0)
157                         display_progress(progress, base_count + i);
158                 free(data);
159
160         }
161         display_progress(progress, base_count + i);
162         free(entries);
163
164         return err;
165 }
166
167 int verify_pack_index(struct packed_git *p)
168 {
169         off_t index_size;
170         const unsigned char *index_base;
171         git_hash_ctx ctx;
172         unsigned char hash[GIT_MAX_RAWSZ];
173         int err = 0;
174
175         if (open_pack_index(p))
176                 return error("packfile %s index not opened", p->pack_name);
177         index_size = p->index_size;
178         index_base = p->index_data;
179
180         /* Verify SHA1 sum of the index file */
181         the_hash_algo->init_fn(&ctx);
182         the_hash_algo->update_fn(&ctx, index_base, (unsigned int)(index_size - the_hash_algo->rawsz));
183         the_hash_algo->final_fn(hash, &ctx);
184         if (!hasheq(hash, index_base + index_size - the_hash_algo->rawsz))
185                 err = error("Packfile index for %s hash mismatch",
186                             p->pack_name);
187         return err;
188 }
189
190 int verify_pack(struct repository *r, struct packed_git *p, verify_fn fn,
191                 struct progress *progress, uint32_t base_count)
192 {
193         int err = 0;
194         struct pack_window *w_curs = NULL;
195
196         err |= verify_pack_index(p);
197         if (!p->index_data)
198                 return -1;
199
200         err |= verify_packfile(r, p, &w_curs, fn, progress, base_count);
201         unuse_pack(&w_curs);
202
203         return err;
204 }