mkbootfs.c revision dd7bc3319deb2b77c5d07a51b7d6cd7e11b5beb0 
1
2#include <stdio.h>
3#include <stdlib.h>
4#include <unistd.h>
5#include <string.h>
6
7#include <sys/types.h>
8#include <sys/stat.h>
9#include <dirent.h>
10
11#include <stdarg.h>
12#include <fcntl.h>
13
14#include <private/android_filesystem_config.h>
15
16/* NOTES
17**
18** - see buffer-format.txt from the linux kernel docs for
19**   an explanation of this file format
20** - dotfiles are ignored
21** - directories named 'root' are ignored
22** - device notes, pipes, etc are not supported (error)
23*/
24
25void die(const char *why, ...)
26{
27    va_list ap;
28
29    va_start(ap, why);
30    fprintf(stderr,"error: ");
31    vfprintf(stderr, why, ap);
32    fprintf(stderr,"\n");
33    va_end(ap);
34    exit(1);
35}
36
37static int verbose = 0;
38static int total_size = 0;
39
40static void fix_stat(const char *path, struct stat *s)
41{
42    fs_config(path, S_ISDIR(s->st_mode), &s->st_uid, &s->st_gid, &s->st_mode);
43}
44
45static void _eject(struct stat *s, char *out, int olen, char *data, unsigned datasize)
46{
47    // Nothing is special about this value, just picked something in the
48    // approximate range that was being used already, and avoiding small
49    // values which may be special.
50    static unsigned next_inode = 300000;
51
52    while(total_size & 3) {
53        total_size++;
54        putchar(0);
55    }
56
57    fix_stat(out, s);
58//    fprintf(stderr, "_eject %s: mode=0%o\n", out, s->st_mode);
59
60    printf("%06x%08x%08x%08x%08x%08x%08x"
61           "%08x%08x%08x%08x%08x%08x%08x%s%c",
62           0x070701,
63           next_inode++,  //  s.st_ino,
64           s->st_mode,
65           0, // s.st_uid,
66           0, // s.st_gid,
67           1, // s.st_nlink,
68           0, // s.st_mtime,
69           datasize,
70           0, // volmajor
71           0, // volminor
72           0, // devmajor
73           0, // devminor,
74           olen + 1,
75           0,
76           out,
77           0
78           );
79
80    total_size += 6 + 8*13 + olen + 1;
81
82    if(strlen(out) != olen) die("ACK!");
83
84    while(total_size & 3) {
85        total_size++;
86        putchar(0);
87    }
88
89    if(datasize) {
90        fwrite(data, datasize, 1, stdout);
91        total_size += datasize;
92    }
93}
94
95static void _eject_trailer()
96{
97    struct stat s;
98    memset(&s, 0, sizeof(s));
99    _eject(&s, "TRAILER!!!", 10, 0, 0);
100
101    while(total_size & 0xff) {
102        total_size++;
103        putchar(0);
104    }
105}
106
107static void _archive(char *in, char *out, int ilen, int olen);
108
109static int compare(const void* a, const void* b) {
110  return strcmp(*(const char**)a, *(const char**)b);
111}
112
113static void _archive_dir(char *in, char *out, int ilen, int olen)
114{
115    int i, t;
116    DIR *d;
117    struct dirent *de;
118
119    if(verbose) {
120        fprintf(stderr,"_archive_dir('%s','%s',%d,%d)\n",
121                in, out, ilen, olen);
122    }
123
124    d = opendir(in);
125    if(d == 0) die("cannot open directory '%s'", in);
126
127    int size = 32;
128    int entries = 0;
129    char** names = malloc(size * sizeof(char*));
130    if (names == NULL) {
131      fprintf(stderr, "failed to allocate dir names array (size %d)\n", size);
132      exit(1);
133    }
134
135    while((de = readdir(d)) != 0){
136            /* xxx: feature? maybe some dotfiles are okay */
137        if(de->d_name[0] == '.') continue;
138
139            /* xxx: hack. use a real exclude list */
140        if(!strcmp(de->d_name, "root")) continue;
141
142        if (entries >= size) {
143          size *= 2;
144          names = realloc(names, size * sizeof(char*));
145          if (names == NULL) {
146            fprintf(stderr, "failed to reallocate dir names array (size %d)\n",
147                    size);
148            exit(1);
149          }
150        }
151        names[entries] = strdup(de->d_name);
152        if (names[entries] == NULL) {
153          fprintf(stderr, "failed to strdup name \"%s\"\n",
154                  de->d_name);
155          exit(1);
156        }
157        ++entries;
158    }
159
160    qsort(names, entries, sizeof(char*), compare);
161
162    for (i = 0; i < entries; ++i) {
163        t = strlen(names[i]);
164        in[ilen] = '/';
165        memcpy(in + ilen + 1, names[i], t + 1);
166
167        if(olen > 0) {
168            out[olen] = '/';
169            memcpy(out + olen + 1, names[i], t + 1);
170            _archive(in, out, ilen + t + 1, olen + t + 1);
171        } else {
172            memcpy(out, names[i], t + 1);
173            _archive(in, out, ilen + t + 1, t);
174        }
175
176        in[ilen] = 0;
177        out[olen] = 0;
178
179        free(names[i]);
180    }
181    free(names);
182}
183
184static void _archive(char *in, char *out, int ilen, int olen)
185{
186    struct stat s;
187
188    if(verbose) {
189        fprintf(stderr,"_archive('%s','%s',%d,%d)\n",
190                in, out, ilen, olen);
191    }
192
193    if(lstat(in, &s)) die("could not stat '%s'\n", in);
194
195    if(S_ISREG(s.st_mode)){
196        char *tmp;
197        int fd;
198
199        fd = open(in, O_RDONLY);
200        if(fd < 0) die("cannot open '%s' for read", in);
201
202        tmp = (char*) malloc(s.st_size);
203        if(tmp == 0) die("cannot allocate %d bytes", s.st_size);
204
205        if(read(fd, tmp, s.st_size) != s.st_size) {
206            die("cannot read %d bytes", s.st_size);
207        }
208
209        _eject(&s, out, olen, tmp, s.st_size);
210
211        free(tmp);
212        close(fd);
213    } else if(S_ISDIR(s.st_mode)) {
214        _eject(&s, out, olen, 0, 0);
215        _archive_dir(in, out, ilen, olen);
216    } else if(S_ISLNK(s.st_mode)) {
217        char buf[1024];
218        int size;
219        size = readlink(in, buf, 1024);
220        if(size < 0) die("cannot read symlink '%s'", in);
221        _eject(&s, out, olen, buf, size);
222    } else {
223        die("Unknown '%s' (mode %d)?\n", in, s.st_mode);
224    }
225}
226
227void archive(const char *start, const char *prefix)
228{
229    char in[8192];
230    char out[8192];
231
232    strcpy(in, start);
233    strcpy(out, prefix);
234
235    _archive_dir(in, out, strlen(in), strlen(out));
236}
237
238int main(int argc, char *argv[])
239{
240    argc--;
241    argv++;
242
243    if(argc == 0) die("no directories to process?!");
244
245    while(argc-- > 0){
246        char *x = strchr(*argv, '=');
247        if(x != 0) {
248            *x++ = 0;
249        } else {
250            x = "";
251        }
252
253        archive(*argv, x);
254
255        argv++;
256    }
257
258    _eject_trailer();
259
260    return 0;
261}
262