summaryrefslogtreecommitdiffstats
blob: 0e35323043ea5bdd62e62d347c8a0ecf2ce7b8ed (plain) (blame)
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
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363

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

#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>

#include <stdarg.h>
#include <fcntl.h>

#include <private/android_filesystem_config.h>

/* NOTES
**
** - see buffer-format.txt from the linux kernel docs for
**   an explanation of this file format
** - dotfiles are ignored
** - directories named 'root' are ignored
** - device notes, pipes, etc are not supported (error)
*/

void die(const char *why, ...)
{
    va_list ap;

    va_start(ap, why);
    fprintf(stderr,"error: ");
    vfprintf(stderr, why, ap);
    fprintf(stderr,"\n");
    va_end(ap);
    exit(1);
}

struct fs_config_entry {
    char* name;
    int uid, gid, mode;
};

static struct fs_config_entry* canned_config = NULL;
static char *target_out_path = NULL;

/* Each line in the canned file should be a path plus three ints (uid,
 * gid, mode). */
#ifdef PATH_MAX
#define CANNED_LINE_LENGTH  (PATH_MAX+100)
#else
#define CANNED_LINE_LENGTH  (1024)
#endif

static int verbose = 0;
static int total_size = 0;

static void fix_stat(const char *path, struct stat *s)
{
    uint64_t capabilities;
    if (canned_config) {
        // Use the list of file uid/gid/modes loaded from the file
        // given with -f.

        struct fs_config_entry* empty_path_config = NULL;
        struct fs_config_entry* p;
        for (p = canned_config; p->name; ++p) {
            if (!p->name[0]) {
                empty_path_config = p;
            }
            if (strcmp(p->name, path) == 0) {
                s->st_uid = p->uid;
                s->st_gid = p->gid;
                s->st_mode = p->mode | (s->st_mode & ~07777);
                return;
            }
        }
        s->st_uid = empty_path_config->uid;
        s->st_gid = empty_path_config->gid;
        s->st_mode = empty_path_config->mode | (s->st_mode & ~07777);
    } else {
        // Use the compiled-in fs_config() function.
        unsigned st_mode = s->st_mode;
        fs_config(path, S_ISDIR(s->st_mode), target_out_path,
                       &s->st_uid, &s->st_gid, &st_mode, &capabilities);
        s->st_mode = (typeof(s->st_mode)) st_mode;
    }
}

static void _eject(struct stat *s, char *out, int olen, char *data, unsigned datasize)
{
    // Nothing is special about this value, just picked something in the
    // approximate range that was being used already, and avoiding small
    // values which may be special.
    static unsigned next_inode = 300000;

    while(total_size & 3) {
        total_size++;
        putchar(0);
    }

    fix_stat(out, s);
//    fprintf(stderr, "_eject %s: mode=0%o\n", out, s->st_mode);

    printf("%06x%08x%08x%08x%08x%08x%08x"
           "%08x%08x%08x%08x%08x%08x%08x%s%c",
           0x070701,
           next_inode++,  //  s.st_ino,
           s->st_mode,
           0, // s.st_uid,
           0, // s.st_gid,
           1, // s.st_nlink,
           0, // s.st_mtime,
           datasize,
           0, // volmajor
           0, // volminor
           0, // devmajor
           0, // devminor,
           olen + 1,
           0,
           out,
           0
           );

    total_size += 6 + 8*13 + olen + 1;

    if(strlen(out) != (unsigned int)olen) die("ACK!");

    while(total_size & 3) {
        total_size++;
        putchar(0);
    }

    if(datasize) {
        fwrite(data, datasize, 1, stdout);
        total_size += datasize;
    }
}

static void _eject_trailer()
{
    struct stat s;
    memset(&s, 0, sizeof(s));
    _eject(&s, "TRAILER!!!", 10, 0, 0);

    while(total_size & 0xff) {
        total_size++;
        putchar(0);
    }
}

static void _archive(char *in, char *out, int ilen, int olen);

static int compare(const void* a, const void* b) {
  return strcmp(*(const char**)a, *(const char**)b);
}

static void _archive_dir(char *in, char *out, int ilen, int olen)
{
    int i, t;
    DIR *d;
    struct dirent *de;

    if(verbose) {
        fprintf(stderr,"_archive_dir('%s','%s',%d,%d)\n",
                in, out, ilen, olen);
    }

    d = opendir(in);
    if(d == 0) die("cannot open directory '%s'", in);

    int size = 32;
    int entries = 0;
    char** names = malloc(size * sizeof(char*));
    if (names == NULL) {
      fprintf(stderr, "failed to allocate dir names array (size %d)\n", size);
      exit(1);
    }

    while((de = readdir(d)) != 0){
            /* xxx: feature? maybe some dotfiles are okay */
        if(de->d_name[0] == '.') continue;

            /* xxx: hack. use a real exclude list */
        if(!strcmp(de->d_name, "root")) continue;

        if (entries >= size) {
          size *= 2;
          names = realloc(names, size * sizeof(char*));
          if (names == NULL) {
            fprintf(stderr, "failed to reallocate dir names array (size %d)\n",
                    size);
            exit(1);
          }
        }
        names[entries] = strdup(de->d_name);
        if (names[entries] == NULL) {
          fprintf(stderr, "failed to strdup name \"%s\"\n",
                  de->d_name);
          exit(1);
        }
        ++entries;
    }

    qsort(names, entries, sizeof(char*), compare);

    for (i = 0; i < entries; ++i) {
        t = strlen(names[i]);
        in[ilen] = '/';
        memcpy(in + ilen + 1, names[i], t + 1);

        if(olen > 0) {
            out[olen] = '/';
            memcpy(out + olen + 1, names[i], t + 1);
            _archive(in, out, ilen + t + 1, olen + t + 1);
        } else {
            memcpy(out, names[i], t + 1);
            _archive(in, out, ilen + t + 1, t);
        }

        in[ilen] = 0;
        out[olen] = 0;

        free(names[i]);
    }
    free(names);

    closedir(d);
}

static void _archive(char *in, char *out, int ilen, int olen)
{
    struct stat s;

    if(verbose) {
        fprintf(stderr,"_archive('%s','%s',%d,%d)\n",
                in, out, ilen, olen);
    }

    if(lstat(in, &s)) die("could not stat '%s'\n", in);

    if(S_ISREG(s.st_mode)){
        char *tmp;
        int fd;

        fd = open(in, O_RDONLY);
        if(fd < 0) die("cannot open '%s' for read", in);

        tmp = (char*) malloc(s.st_size);
        if(tmp == 0) die("cannot allocate %d bytes", s.st_size);

        if(read(fd, tmp, s.st_size) != s.st_size) {
            die("cannot read %d bytes", s.st_size);
        }

        _eject(&s, out, olen, tmp, s.st_size);

        free(tmp);
        close(fd);
    } else if(S_ISDIR(s.st_mode)) {
        _eject(&s, out, olen, 0, 0);
        _archive_dir(in, out, ilen, olen);
    } else if(S_ISLNK(s.st_mode)) {
        char buf[1024];
        int size;
        size = readlink(in, buf, 1024);
        if(size < 0) die("cannot read symlink '%s'", in);
        _eject(&s, out, olen, buf, size);
    } else {
        die("Unknown '%s' (mode %d)?\n", in, s.st_mode);
    }
}

void archive(const char *start, const char *prefix)
{
    char in[8192];
    char out[8192];

    strcpy(in, start);
    strcpy(out, prefix);

    _archive_dir(in, out, strlen(in), strlen(out));
}

static void read_canned_config(char* filename)
{
    int allocated = 8;
    int used = 0;

    canned_config =
        (struct fs_config_entry*)malloc(allocated * sizeof(struct fs_config_entry));

    char line[CANNED_LINE_LENGTH];
    FILE* f = fopen(filename, "r");
    if (f == NULL) die("failed to open canned file");

    while (fgets(line, CANNED_LINE_LENGTH, f) != NULL) {
        if (!line[0]) break;
        if (used >= allocated) {
            allocated *= 2;
            canned_config = (struct fs_config_entry*)realloc(
                canned_config, allocated * sizeof(struct fs_config_entry));
        }

        struct fs_config_entry* cc = canned_config + used;

        if (isspace(line[0])) {
            cc->name = strdup("");
            cc->uid = atoi(strtok(line, " \n"));
        } else {
            cc->name = strdup(strtok(line, " \n"));
            cc->uid = atoi(strtok(NULL, " \n"));
        }
        cc->gid = atoi(strtok(NULL, " \n"));
        cc->mode = strtol(strtok(NULL, " \n"), NULL, 8);
        ++used;
    }
    if (used >= allocated) {
        ++allocated;
        canned_config = (struct fs_config_entry*)realloc(
            canned_config, allocated * sizeof(struct fs_config_entry));
    }
    canned_config[used].name = NULL;

    fclose(f);
}


int main(int argc, char *argv[])
{
    argc--;
    argv++;

    if (argc > 1 && strcmp(argv[0], "-d") == 0) {
        target_out_path = argv[1];
        argc -= 2;
        argv += 2;
    }

    if (argc > 1 && strcmp(argv[0], "-f") == 0) {
        read_canned_config(argv[1]);
        argc -= 2;
        argv += 2;
    }

    if(argc == 0) die("no directories to process?!");

    while(argc-- > 0){
        char *x = strchr(*argv, '=');
        if(x != 0) {
            *x++ = 0;
        } else {
            x = "";
        }

        archive(*argv, x);

        argv++;
    }

    _eject_trailer();

    return 0;
}