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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 | 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; | |
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 | ||
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); | |
118 | } | |
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; | |
132 | } | |
133 | if (((base_count + i) & 1023) == 0) | |
134 | display_progress(progress, base_count + i); | |
135 | free(data); | |
136 | ||
137 | } | |
138 | display_progress(progress, base_count + i); | |
139 | free(entries); | |
140 | ||
141 | return err; | |
142 | } | |
143 | ||
144 | int verify_pack_index(struct packed_git *p) | |
145 | { | |
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; | |
151 | ||
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; | |
156 | ||
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; | |
165 | } | |
166 | ||
167 | int verify_pack(struct packed_git *p, verify_fn fn, | |
168 | struct progress *progress, uint32_t base_count) | |
169 | { | |
170 | int err = 0; | |
171 | struct pack_window *w_curs = NULL; | |
172 | ||
173 | err |= verify_pack_index(p); | |
174 | if (!p->index_data) | |
175 | return -1; | |
176 | ||
177 | err |= verify_packfile(p, &w_curs, fn, progress, base_count); | |
178 | unuse_pack(&w_curs); | |
179 | ||
180 | return err; | |
181 | } |