aboutsummaryrefslogtreecommitdiffstats
path: root/applypatch/main.c
blob: f61db5d9ebf3ed000fda0522ff9b0810026812a5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
/*
 * Copyright (C) 2009 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "applypatch.h"
#include "edify/expr.h"
#include "mincrypt/sha.h"

int CheckMode(int argc, char** argv) {
    if (argc < 3) {
        return 2;
    }
    return applypatch_check(argv[2], argc-3, argv+3);
}

int SpaceMode(int argc, char** argv) {
    if (argc != 3) {
        return 2;
    }
    char* endptr;
    size_t bytes = strtol(argv[2], &endptr, 10);
    if (bytes == 0 && endptr == argv[2]) {
        printf("can't parse \"%s\" as byte count\n\n", argv[2]);
        return 1;
    }
    return CacheSizeCheck(bytes);
}

// Parse arguments (which should be of the form "<sha1>" or
// "<sha1>:<filename>" into the new parallel arrays *sha1s and
// *patches (loading file contents into the patches).  Returns 0 on
// success.
static int ParsePatchArgs(int argc, char** argv,
                          char*** sha1s, Value*** patches, int* num_patches) {
    *num_patches = argc;
    *sha1s = malloc(*num_patches * sizeof(char*));
    *patches = malloc(*num_patches * sizeof(Value*));
    memset(*patches, 0, *num_patches * sizeof(Value*));

    uint8_t digest[SHA_DIGEST_SIZE];

    int i;
    for (i = 0; i < *num_patches; ++i) {
        char* colon = strchr(argv[i], ':');
        if (colon != NULL) {
            *colon = '\0';
            ++colon;
        }

        if (ParseSha1(argv[i], digest) != 0) {
            printf("failed to parse sha1 \"%s\"\n", argv[i]);
            return -1;
        }

        (*sha1s)[i] = argv[i];
        if (colon == NULL) {
            (*patches)[i] = NULL;
        } else {
            FileContents fc;
            if (LoadFileContents(colon, &fc, RETOUCH_DONT_MASK) != 0) {
                goto abort;
            }
            (*patches)[i] = malloc(sizeof(Value));
            (*patches)[i]->type = VAL_BLOB;
            (*patches)[i]->size = fc.size;
            (*patches)[i]->data = (char*)fc.data;
        }
    }

    return 0;

  abort:
    for (i = 0; i < *num_patches; ++i) {
        Value* p = (*patches)[i];
        if (p != NULL) {
            free(p->data);
            free(p);
        }
    }
    free(*sha1s);
    free(*patches);
    return -1;
}

int PatchMode(int argc, char** argv) {
    Value* bonus = NULL;
    if (argc >= 3 && strcmp(argv[1], "-b") == 0) {
        FileContents fc;
        if (LoadFileContents(argv[2], &fc, RETOUCH_DONT_MASK) != 0) {
            printf("failed to load bonus file %s\n", argv[2]);
            return 1;
        }
        bonus = malloc(sizeof(Value));
        bonus->type = VAL_BLOB;
        bonus->size = fc.size;
        bonus->data = (char*)fc.data;
        argc -= 2;
        argv += 2;
    }

    if (argc < 6) {
        return 2;
    }

    char* endptr;
    size_t target_size = strtol(argv[4], &endptr, 10);
    if (target_size == 0 && endptr == argv[4]) {
        printf("can't parse \"%s\" as byte count\n\n", argv[4]);
        return 1;
    }

    char** sha1s;
    Value** patches;
    int num_patches;
    if (ParsePatchArgs(argc-5, argv+5, &sha1s, &patches, &num_patches) != 0) {
        printf("failed to parse patch args\n");
        return 1;
    }

    int result = applypatch(argv[1], argv[2], argv[3], target_size,
                            num_patches, sha1s, patches, bonus);

    int i;
    for (i = 0; i < num_patches; ++i) {
        Value* p = patches[i];
        if (p != NULL) {
            free(p->data);
            free(p);
        }
    }
    if (bonus) {
        free(bonus->data);
        free(bonus);
    }
    free(sha1s);
    free(patches);

    return result;
}

// This program applies binary patches to files in a way that is safe
// (the original file is not touched until we have the desired
// replacement for it) and idempotent (it's okay to run this program
// multiple times).
//
// - if the sha1 hash of <tgt-file> is <tgt-sha1>, does nothing and exits
//   successfully.
//
// - otherwise, if the sha1 hash of <src-file> is <src-sha1>, applies the
//   bsdiff <patch> to <src-file> to produce a new file (the type of patch
//   is automatically detected from the file header).  If that new
//   file has sha1 hash <tgt-sha1>, moves it to replace <tgt-file>, and
//   exits successfully.  Note that if <src-file> and <tgt-file> are
//   not the same, <src-file> is NOT deleted on success.  <tgt-file>
//   may be the string "-" to mean "the same as src-file".
//
// - otherwise, or if any error is encountered, exits with non-zero
//   status.
//
// <src-file> (or <file> in check mode) may refer to an MTD partition
// to read the source data.  See the comments for the
// LoadMTDContents() function above for the format of such a filename.

int main(int argc, char** argv) {
    if (argc < 2) {
      usage:
        printf(
            "usage: %s [-b <bonus-file>] <src-file> <tgt-file> <tgt-sha1> <tgt-size> "
            "[<src-sha1>:<patch> ...]\n"
            "   or  %s -c <file> [<sha1> ...]\n"
            "   or  %s -s <bytes>\n"
            "   or  %s -l\n"
            "\n"
            "Filenames may be of the form\n"
            "  MTD:<partition>:<len_1>:<sha1_1>:<len_2>:<sha1_2>:...\n"
            "to specify reading from or writing to an MTD partition.\n\n",
            argv[0], argv[0], argv[0], argv[0]);
        return 2;
    }

    int result;

    if (strncmp(argv[1], "-l", 3) == 0) {
        result = ShowLicenses();
    } else if (strncmp(argv[1], "-c", 3) == 0) {
        result = CheckMode(argc, argv);
    } else if (strncmp(argv[1], "-s", 3) == 0) {
        result = SpaceMode(argc, argv);
    } else {
        result = PatchMode(argc, argv);
    }

    if (result == 2) {
        goto usage;
    }
    return result;
}