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