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1 
2 #include <stdio.h>
3 #include <stdlib.h>
4 #include <unistd.h>
5 #include <string.h>
6 #include <ctype.h>
7 
8 #include <sys/types.h>
9 #include <sys/stat.h>
10 #include <dirent.h>
11 
12 #include <stdarg.h>
13 #include <fcntl.h>
14 
15 #include <private/android_filesystem_config.h>
16 
17 /* NOTES
18 **
19 ** - see buffer-format.txt from the linux kernel docs for
20 **   an explanation of this file format
21 ** - dotfiles are ignored
22 ** - directories named 'root' are ignored
23 ** - device notes, pipes, etc are not supported (error)
24 */
25 
die(const char * why,...)26 void die(const char *why, ...)
27 {
28     va_list ap;
29 
30     va_start(ap, why);
31     fprintf(stderr,"error: ");
32     vfprintf(stderr, why, ap);
33     fprintf(stderr,"\n");
34     va_end(ap);
35     exit(1);
36 }
37 
38 struct fs_config_entry {
39     char* name;
40     int uid, gid, mode;
41 };
42 
43 static struct fs_config_entry* canned_config = NULL;
44 
45 /* Each line in the canned file should be a path plus three ints (uid,
46  * gid, mode). */
47 #ifdef PATH_MAX
48 #define CANNED_LINE_LENGTH  (PATH_MAX+100)
49 #else
50 #define CANNED_LINE_LENGTH  (1024)
51 #endif
52 
53 static int verbose = 0;
54 static int total_size = 0;
55 
fix_stat(const char * path,struct stat * s)56 static void fix_stat(const char *path, struct stat *s)
57 {
58     if (canned_config) {
59         // Use the list of file uid/gid/modes loaded from the file
60         // given with -f.
61 
62         struct fs_config_entry* empty_path_config = NULL;
63         struct fs_config_entry* p;
64         for (p = canned_config; p->name; ++p) {
65             if (!p->name[0]) {
66                 empty_path_config = p;
67             }
68             if (strcmp(p->name, path) == 0) {
69                 s->st_uid = p->uid;
70                 s->st_gid = p->gid;
71                 s->st_mode = p->mode | (s->st_mode & ~07777);
72                 return;
73             }
74         }
75         s->st_uid = empty_path_config->uid;
76         s->st_gid = empty_path_config->gid;
77         s->st_mode = empty_path_config->mode | (s->st_mode & ~07777);
78     } else {
79         // Use the compiled-in fs_config() function.
80 
81         fs_config(path, S_ISDIR(s->st_mode), &s->st_uid, &s->st_gid, &s->st_mode);
82     }
83 }
84 
_eject(struct stat * s,char * out,int olen,char * data,unsigned datasize)85 static void _eject(struct stat *s, char *out, int olen, char *data, unsigned datasize)
86 {
87     // Nothing is special about this value, just picked something in the
88     // approximate range that was being used already, and avoiding small
89     // values which may be special.
90     static unsigned next_inode = 300000;
91 
92     while(total_size & 3) {
93         total_size++;
94         putchar(0);
95     }
96 
97     fix_stat(out, s);
98 //    fprintf(stderr, "_eject %s: mode=0%o\n", out, s->st_mode);
99 
100     printf("%06x%08x%08x%08x%08x%08x%08x"
101            "%08x%08x%08x%08x%08x%08x%08x%s%c",
102            0x070701,
103            next_inode++,  //  s.st_ino,
104            s->st_mode,
105            0, // s.st_uid,
106            0, // s.st_gid,
107            1, // s.st_nlink,
108            0, // s.st_mtime,
109            datasize,
110            0, // volmajor
111            0, // volminor
112            0, // devmajor
113            0, // devminor,
114            olen + 1,
115            0,
116            out,
117            0
118            );
119 
120     total_size += 6 + 8*13 + olen + 1;
121 
122     if(strlen(out) != (unsigned int)olen) die("ACK!");
123 
124     while(total_size & 3) {
125         total_size++;
126         putchar(0);
127     }
128 
129     if(datasize) {
130         fwrite(data, datasize, 1, stdout);
131         total_size += datasize;
132     }
133 }
134 
_eject_trailer()135 static void _eject_trailer()
136 {
137     struct stat s;
138     memset(&s, 0, sizeof(s));
139     _eject(&s, "TRAILER!!!", 10, 0, 0);
140 
141     while(total_size & 0xff) {
142         total_size++;
143         putchar(0);
144     }
145 }
146 
147 static void _archive(char *in, char *out, int ilen, int olen);
148 
compare(const void * a,const void * b)149 static int compare(const void* a, const void* b) {
150   return strcmp(*(const char**)a, *(const char**)b);
151 }
152 
_archive_dir(char * in,char * out,int ilen,int olen)153 static void _archive_dir(char *in, char *out, int ilen, int olen)
154 {
155     int i, t;
156     DIR *d;
157     struct dirent *de;
158 
159     if(verbose) {
160         fprintf(stderr,"_archive_dir('%s','%s',%d,%d)\n",
161                 in, out, ilen, olen);
162     }
163 
164     d = opendir(in);
165     if(d == 0) die("cannot open directory '%s'", in);
166 
167     int size = 32;
168     int entries = 0;
169     char** names = malloc(size * sizeof(char*));
170     if (names == NULL) {
171       fprintf(stderr, "failed to allocate dir names array (size %d)\n", size);
172       exit(1);
173     }
174 
175     while((de = readdir(d)) != 0){
176             /* xxx: feature? maybe some dotfiles are okay */
177         if(de->d_name[0] == '.') continue;
178 
179             /* xxx: hack. use a real exclude list */
180         if(!strcmp(de->d_name, "root")) continue;
181 
182         if (entries >= size) {
183           size *= 2;
184           names = realloc(names, size * sizeof(char*));
185           if (names == NULL) {
186             fprintf(stderr, "failed to reallocate dir names array (size %d)\n",
187                     size);
188             exit(1);
189           }
190         }
191         names[entries] = strdup(de->d_name);
192         if (names[entries] == NULL) {
193           fprintf(stderr, "failed to strdup name \"%s\"\n",
194                   de->d_name);
195           exit(1);
196         }
197         ++entries;
198     }
199 
200     qsort(names, entries, sizeof(char*), compare);
201 
202     for (i = 0; i < entries; ++i) {
203         t = strlen(names[i]);
204         in[ilen] = '/';
205         memcpy(in + ilen + 1, names[i], t + 1);
206 
207         if(olen > 0) {
208             out[olen] = '/';
209             memcpy(out + olen + 1, names[i], t + 1);
210             _archive(in, out, ilen + t + 1, olen + t + 1);
211         } else {
212             memcpy(out, names[i], t + 1);
213             _archive(in, out, ilen + t + 1, t);
214         }
215 
216         in[ilen] = 0;
217         out[olen] = 0;
218 
219         free(names[i]);
220     }
221     free(names);
222 }
223 
_archive(char * in,char * out,int ilen,int olen)224 static void _archive(char *in, char *out, int ilen, int olen)
225 {
226     struct stat s;
227 
228     if(verbose) {
229         fprintf(stderr,"_archive('%s','%s',%d,%d)\n",
230                 in, out, ilen, olen);
231     }
232 
233     if(lstat(in, &s)) die("could not stat '%s'\n", in);
234 
235     if(S_ISREG(s.st_mode)){
236         char *tmp;
237         int fd;
238 
239         fd = open(in, O_RDONLY);
240         if(fd < 0) die("cannot open '%s' for read", in);
241 
242         tmp = (char*) malloc(s.st_size);
243         if(tmp == 0) die("cannot allocate %d bytes", s.st_size);
244 
245         if(read(fd, tmp, s.st_size) != s.st_size) {
246             die("cannot read %d bytes", s.st_size);
247         }
248 
249         _eject(&s, out, olen, tmp, s.st_size);
250 
251         free(tmp);
252         close(fd);
253     } else if(S_ISDIR(s.st_mode)) {
254         _eject(&s, out, olen, 0, 0);
255         _archive_dir(in, out, ilen, olen);
256     } else if(S_ISLNK(s.st_mode)) {
257         char buf[1024];
258         int size;
259         size = readlink(in, buf, 1024);
260         if(size < 0) die("cannot read symlink '%s'", in);
261         _eject(&s, out, olen, buf, size);
262     } else {
263         die("Unknown '%s' (mode %d)?\n", in, s.st_mode);
264     }
265 }
266 
archive(const char * start,const char * prefix)267 void archive(const char *start, const char *prefix)
268 {
269     char in[8192];
270     char out[8192];
271 
272     strcpy(in, start);
273     strcpy(out, prefix);
274 
275     _archive_dir(in, out, strlen(in), strlen(out));
276 }
277 
read_canned_config(char * filename)278 static void read_canned_config(char* filename)
279 {
280     int allocated = 8;
281     int used = 0;
282 
283     canned_config =
284         (struct fs_config_entry*)malloc(allocated * sizeof(struct fs_config_entry));
285 
286     char line[CANNED_LINE_LENGTH];
287     FILE* f = fopen(filename, "r");
288     if (f == NULL) die("failed to open canned file");
289 
290     while (fgets(line, CANNED_LINE_LENGTH, f) != NULL) {
291         if (!line[0]) break;
292         if (used >= allocated) {
293             allocated *= 2;
294             canned_config = (struct fs_config_entry*)realloc(
295                 canned_config, allocated * sizeof(struct fs_config_entry));
296         }
297 
298         struct fs_config_entry* cc = canned_config + used;
299 
300         if (isspace(line[0])) {
301             cc->name = strdup("");
302             cc->uid = atoi(strtok(line, " \n"));
303         } else {
304             cc->name = strdup(strtok(line, " \n"));
305             cc->uid = atoi(strtok(NULL, " \n"));
306         }
307         cc->gid = atoi(strtok(NULL, " \n"));
308         cc->mode = strtol(strtok(NULL, " \n"), NULL, 8);
309         ++used;
310     }
311     if (used >= allocated) {
312         ++allocated;
313         canned_config = (struct fs_config_entry*)realloc(
314             canned_config, allocated * sizeof(struct fs_config_entry));
315     }
316     canned_config[used].name = NULL;
317 
318     fclose(f);
319 }
320 
321 
main(int argc,char * argv[])322 int main(int argc, char *argv[])
323 {
324     argc--;
325     argv++;
326 
327     if (argc > 1 && strcmp(argv[0], "-f") == 0) {
328         read_canned_config(argv[1]);
329         argc -= 2;
330         argv += 2;
331     }
332 
333     if(argc == 0) die("no directories to process?!");
334 
335     while(argc-- > 0){
336         char *x = strchr(*argv, '=');
337         if(x != 0) {
338             *x++ = 0;
339         } else {
340             x = "";
341         }
342 
343         archive(*argv, x);
344 
345         argv++;
346     }
347 
348     _eject_trailer();
349 
350     return 0;
351 }
352