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 #include <private/fs_config.h>
17 
18 /* NOTES
19 **
20 ** - see buffer-format.txt from the linux kernel docs for
21 **   an explanation of this file format
22 ** - dotfiles are ignored
23 ** - directories named 'root' are ignored
24 ** - device notes, pipes, etc are not supported (error)
25 */
26 
die(const char * why,...)27 void die(const char *why, ...)
28 {
29     va_list ap;
30 
31     va_start(ap, why);
32     fprintf(stderr,"error: ");
33     vfprintf(stderr, why, ap);
34     fprintf(stderr,"\n");
35     va_end(ap);
36     exit(1);
37 }
38 
39 struct fs_config_entry {
40     char* name;
41     int uid, gid, mode;
42 };
43 
44 static struct fs_config_entry* canned_config = NULL;
45 static char *target_out_path = NULL;
46 
47 /* Each line in the canned file should be a path plus three ints (uid,
48  * gid, mode). */
49 #ifdef PATH_MAX
50 #define CANNED_LINE_LENGTH  (PATH_MAX+100)
51 #else
52 #define CANNED_LINE_LENGTH  (1024)
53 #endif
54 
55 #define TRAILER "TRAILER!!!"
56 
57 static int verbose = 0;
58 static int total_size = 0;
59 
fix_stat(const char * path,struct stat * s)60 static void fix_stat(const char *path, struct stat *s)
61 {
62     uint64_t capabilities;
63     if (canned_config) {
64         // Use the list of file uid/gid/modes loaded from the file
65         // given with -f.
66 
67         struct fs_config_entry* empty_path_config = NULL;
68         struct fs_config_entry* p;
69         for (p = canned_config; p->name; ++p) {
70             if (!p->name[0]) {
71                 empty_path_config = p;
72             }
73             if (strcmp(p->name, path) == 0) {
74                 s->st_uid = p->uid;
75                 s->st_gid = p->gid;
76                 s->st_mode = p->mode | (s->st_mode & ~07777);
77                 return;
78             }
79         }
80         s->st_uid = empty_path_config->uid;
81         s->st_gid = empty_path_config->gid;
82         s->st_mode = empty_path_config->mode | (s->st_mode & ~07777);
83     } else {
84         // Use the compiled-in fs_config() function.
85         unsigned st_mode = s->st_mode;
86         int is_dir = S_ISDIR(s->st_mode) || strcmp(path, TRAILER) == 0;
87         fs_config(path, is_dir, target_out_path, &s->st_uid, &s->st_gid, &st_mode, &capabilities);
88         s->st_mode = (typeof(s->st_mode)) st_mode;
89     }
90 }
91 
_eject(struct stat * s,char * out,int olen,char * data,unsigned datasize)92 static void _eject(struct stat *s, char *out, int olen, char *data, unsigned datasize)
93 {
94     // Nothing is special about this value, just picked something in the
95     // approximate range that was being used already, and avoiding small
96     // values which may be special.
97     static unsigned next_inode = 300000;
98 
99     while(total_size & 3) {
100         total_size++;
101         putchar(0);
102     }
103 
104     fix_stat(out, s);
105 //    fprintf(stderr, "_eject %s: mode=0%o\n", out, s->st_mode);
106 
107     printf("%06x%08x%08x%08x%08x%08x%08x"
108            "%08x%08x%08x%08x%08x%08x%08x%s%c",
109            0x070701,
110            next_inode++,  //  s.st_ino,
111            s->st_mode,
112            0, // s.st_uid,
113            0, // s.st_gid,
114            1, // s.st_nlink,
115            0, // s.st_mtime,
116            datasize,
117            0, // volmajor
118            0, // volminor
119            0, // devmajor
120            0, // devminor,
121            olen + 1,
122            0,
123            out,
124            0
125            );
126 
127     total_size += 6 + 8*13 + olen + 1;
128 
129     if(strlen(out) != (unsigned int)olen) die("ACK!");
130 
131     while(total_size & 3) {
132         total_size++;
133         putchar(0);
134     }
135 
136     if(datasize) {
137         fwrite(data, datasize, 1, stdout);
138         total_size += datasize;
139     }
140 }
141 
_eject_trailer()142 static void _eject_trailer()
143 {
144     struct stat s;
145     memset(&s, 0, sizeof(s));
146     _eject(&s, TRAILER, 10, 0, 0);
147 
148     while(total_size & 0xff) {
149         total_size++;
150         putchar(0);
151     }
152 }
153 
154 static void _archive(char *in, char *out, int ilen, int olen);
155 
compare(const void * a,const void * b)156 static int compare(const void* a, const void* b) {
157   return strcmp(*(const char**)a, *(const char**)b);
158 }
159 
_archive_dir(char * in,char * out,int ilen,int olen)160 static void _archive_dir(char *in, char *out, int ilen, int olen)
161 {
162     int i, t;
163     DIR *d;
164     struct dirent *de;
165 
166     if(verbose) {
167         fprintf(stderr,"_archive_dir('%s','%s',%d,%d)\n",
168                 in, out, ilen, olen);
169     }
170 
171     d = opendir(in);
172     if(d == 0) die("cannot open directory '%s'", in);
173 
174     int size = 32;
175     int entries = 0;
176     char** names = malloc(size * sizeof(char*));
177     if (names == NULL) {
178       fprintf(stderr, "failed to allocate dir names array (size %d)\n", size);
179       exit(1);
180     }
181 
182     while((de = readdir(d)) != 0){
183             /* xxx: feature? maybe some dotfiles are okay */
184         if(de->d_name[0] == '.') continue;
185 
186             /* xxx: hack. use a real exclude list */
187         if(!strcmp(de->d_name, "root")) continue;
188 
189         if (entries >= size) {
190           size *= 2;
191           names = realloc(names, size * sizeof(char*));
192           if (names == NULL) {
193             fprintf(stderr, "failed to reallocate dir names array (size %d)\n",
194                     size);
195             exit(1);
196           }
197         }
198         names[entries] = strdup(de->d_name);
199         if (names[entries] == NULL) {
200           fprintf(stderr, "failed to strdup name \"%s\"\n",
201                   de->d_name);
202           exit(1);
203         }
204         ++entries;
205     }
206 
207     qsort(names, entries, sizeof(char*), compare);
208 
209     for (i = 0; i < entries; ++i) {
210         t = strlen(names[i]);
211         in[ilen] = '/';
212         memcpy(in + ilen + 1, names[i], t + 1);
213 
214         if(olen > 0) {
215             out[olen] = '/';
216             memcpy(out + olen + 1, names[i], t + 1);
217             _archive(in, out, ilen + t + 1, olen + t + 1);
218         } else {
219             memcpy(out, names[i], t + 1);
220             _archive(in, out, ilen + t + 1, t);
221         }
222 
223         in[ilen] = 0;
224         out[olen] = 0;
225 
226         free(names[i]);
227     }
228     free(names);
229 
230     closedir(d);
231 }
232 
_archive(char * in,char * out,int ilen,int olen)233 static void _archive(char *in, char *out, int ilen, int olen)
234 {
235     struct stat s;
236 
237     if(verbose) {
238         fprintf(stderr,"_archive('%s','%s',%d,%d)\n",
239                 in, out, ilen, olen);
240     }
241 
242     if(lstat(in, &s)) die("could not stat '%s'\n", in);
243 
244     if(S_ISREG(s.st_mode)){
245         char *tmp;
246         int fd;
247 
248         fd = open(in, O_RDONLY);
249         if(fd < 0) die("cannot open '%s' for read", in);
250 
251         tmp = (char*) malloc(s.st_size);
252         if(tmp == 0) die("cannot allocate %d bytes", s.st_size);
253 
254         if(read(fd, tmp, s.st_size) != s.st_size) {
255             die("cannot read %d bytes", s.st_size);
256         }
257 
258         _eject(&s, out, olen, tmp, s.st_size);
259 
260         free(tmp);
261         close(fd);
262     } else if(S_ISDIR(s.st_mode)) {
263         _eject(&s, out, olen, 0, 0);
264         _archive_dir(in, out, ilen, olen);
265     } else if(S_ISLNK(s.st_mode)) {
266         char buf[1024];
267         int size;
268         size = readlink(in, buf, 1024);
269         if(size < 0) die("cannot read symlink '%s'", in);
270         _eject(&s, out, olen, buf, size);
271     } else {
272         die("Unknown '%s' (mode %d)?\n", in, s.st_mode);
273     }
274 }
275 
archive(const char * start,const char * prefix)276 void archive(const char *start, const char *prefix)
277 {
278     char in[8192];
279     char out[8192];
280 
281     strcpy(in, start);
282     strcpy(out, prefix);
283 
284     _archive_dir(in, out, strlen(in), strlen(out));
285 }
286 
read_canned_config(char * filename)287 static void read_canned_config(char* filename)
288 {
289     int allocated = 8;
290     int used = 0;
291 
292     canned_config =
293         (struct fs_config_entry*)malloc(allocated * sizeof(struct fs_config_entry));
294 
295     char line[CANNED_LINE_LENGTH];
296     FILE* f = fopen(filename, "r");
297     if (f == NULL) die("failed to open canned file");
298 
299     while (fgets(line, CANNED_LINE_LENGTH, f) != NULL) {
300         if (!line[0]) break;
301         if (used >= allocated) {
302             allocated *= 2;
303             canned_config = (struct fs_config_entry*)realloc(
304                 canned_config, allocated * sizeof(struct fs_config_entry));
305             if (canned_config == NULL) die("failed to reallocate memory");
306         }
307 
308         struct fs_config_entry* cc = canned_config + used;
309 
310         if (isspace(line[0])) {
311             cc->name = strdup("");
312             cc->uid = atoi(strtok(line, " \n"));
313         } else {
314             cc->name = strdup(strtok(line, " \n"));
315             cc->uid = atoi(strtok(NULL, " \n"));
316         }
317         cc->gid = atoi(strtok(NULL, " \n"));
318         cc->mode = strtol(strtok(NULL, " \n"), NULL, 8);
319         ++used;
320     }
321     if (used >= allocated) {
322         ++allocated;
323         canned_config = (struct fs_config_entry*)realloc(
324             canned_config, allocated * sizeof(struct fs_config_entry));
325         if (canned_config == NULL) die("failed to reallocate memory");
326     }
327     canned_config[used].name = NULL;
328 
329     fclose(f);
330 }
331 
332 
main(int argc,char * argv[])333 int main(int argc, char *argv[])
334 {
335     argc--;
336     argv++;
337 
338     if (argc > 1 && strcmp(argv[0], "-d") == 0) {
339         target_out_path = argv[1];
340         argc -= 2;
341         argv += 2;
342     }
343 
344     if (argc > 1 && strcmp(argv[0], "-f") == 0) {
345         read_canned_config(argv[1]);
346         argc -= 2;
347         argv += 2;
348     }
349 
350     if(argc == 0) die("no directories to process?!");
351 
352     while(argc-- > 0){
353         char *x = strchr(*argv, '=');
354         if(x != 0) {
355             *x++ = 0;
356         } else {
357             x = "";
358         }
359 
360         archive(*argv, x);
361 
362         argv++;
363     }
364 
365     _eject_trailer();
366 
367     return 0;
368 }
369