Root/usr/gen_init_cpio.c

1#include <stdio.h>
2#include <stdlib.h>
3#include <sys/types.h>
4#include <sys/stat.h>
5#include <string.h>
6#include <unistd.h>
7#include <time.h>
8#include <fcntl.h>
9#include <errno.h>
10#include <ctype.h>
11#include <limits.h>
12
13/*
14 * Original work by Jeff Garzik
15 *
16 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
17 * Hard link support by Luciano Rocha
18 */
19
20#define xstr(s) #s
21#define str(s) xstr(s)
22
23static unsigned int offset;
24static unsigned int ino = 721;
25static time_t default_mtime;
26
27struct file_handler {
28    const char *type;
29    int (*handler)(const char *line);
30};
31
32static void push_string(const char *name)
33{
34    unsigned int name_len = strlen(name) + 1;
35
36    fputs(name, stdout);
37    putchar(0);
38    offset += name_len;
39}
40
41static void push_pad (void)
42{
43    while (offset & 3) {
44        putchar(0);
45        offset++;
46    }
47}
48
49static void push_rest(const char *name)
50{
51    unsigned int name_len = strlen(name) + 1;
52    unsigned int tmp_ofs;
53
54    fputs(name, stdout);
55    putchar(0);
56    offset += name_len;
57
58    tmp_ofs = name_len + 110;
59    while (tmp_ofs & 3) {
60        putchar(0);
61        offset++;
62        tmp_ofs++;
63    }
64}
65
66static void push_hdr(const char *s)
67{
68    fputs(s, stdout);
69    offset += 110;
70}
71
72static void cpio_trailer(void)
73{
74    char s[256];
75    const char name[] = "TRAILER!!!";
76
77    sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
78           "%08X%08X%08X%08X%08X%08X%08X",
79        "070701", /* magic */
80        0, /* ino */
81        0, /* mode */
82        (long) 0, /* uid */
83        (long) 0, /* gid */
84        1, /* nlink */
85        (long) 0, /* mtime */
86        0, /* filesize */
87        0, /* major */
88        0, /* minor */
89        0, /* rmajor */
90        0, /* rminor */
91        (unsigned)strlen(name)+1, /* namesize */
92        0); /* chksum */
93    push_hdr(s);
94    push_rest(name);
95
96    while (offset % 512) {
97        putchar(0);
98        offset++;
99    }
100}
101
102static int cpio_mkslink(const char *name, const char *target,
103             unsigned int mode, uid_t uid, gid_t gid)
104{
105    char s[256];
106
107    if (name[0] == '/')
108        name++;
109    sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
110           "%08X%08X%08X%08X%08X%08X%08X",
111        "070701", /* magic */
112        ino++, /* ino */
113        S_IFLNK | mode, /* mode */
114        (long) uid, /* uid */
115        (long) gid, /* gid */
116        1, /* nlink */
117        (long) default_mtime, /* mtime */
118        (unsigned)strlen(target)+1, /* filesize */
119        3, /* major */
120        1, /* minor */
121        0, /* rmajor */
122        0, /* rminor */
123        (unsigned)strlen(name) + 1,/* namesize */
124        0); /* chksum */
125    push_hdr(s);
126    push_string(name);
127    push_pad();
128    push_string(target);
129    push_pad();
130    return 0;
131}
132
133static int cpio_mkslink_line(const char *line)
134{
135    char name[PATH_MAX + 1];
136    char target[PATH_MAX + 1];
137    unsigned int mode;
138    int uid;
139    int gid;
140    int rc = -1;
141
142    if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
143        fprintf(stderr, "Unrecognized dir format '%s'", line);
144        goto fail;
145    }
146    rc = cpio_mkslink(name, target, mode, uid, gid);
147 fail:
148    return rc;
149}
150
151static int cpio_mkgeneric(const char *name, unsigned int mode,
152               uid_t uid, gid_t gid)
153{
154    char s[256];
155
156    if (name[0] == '/')
157        name++;
158    sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
159           "%08X%08X%08X%08X%08X%08X%08X",
160        "070701", /* magic */
161        ino++, /* ino */
162        mode, /* mode */
163        (long) uid, /* uid */
164        (long) gid, /* gid */
165        2, /* nlink */
166        (long) default_mtime, /* mtime */
167        0, /* filesize */
168        3, /* major */
169        1, /* minor */
170        0, /* rmajor */
171        0, /* rminor */
172        (unsigned)strlen(name) + 1,/* namesize */
173        0); /* chksum */
174    push_hdr(s);
175    push_rest(name);
176    return 0;
177}
178
179enum generic_types {
180    GT_DIR,
181    GT_PIPE,
182    GT_SOCK
183};
184
185struct generic_type {
186    const char *type;
187    mode_t mode;
188};
189
190static struct generic_type generic_type_table[] = {
191    [GT_DIR] = {
192        .type = "dir",
193        .mode = S_IFDIR
194    },
195    [GT_PIPE] = {
196        .type = "pipe",
197        .mode = S_IFIFO
198    },
199    [GT_SOCK] = {
200        .type = "sock",
201        .mode = S_IFSOCK
202    }
203};
204
205static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
206{
207    char name[PATH_MAX + 1];
208    unsigned int mode;
209    int uid;
210    int gid;
211    int rc = -1;
212
213    if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
214        fprintf(stderr, "Unrecognized %s format '%s'",
215            line, generic_type_table[gt].type);
216        goto fail;
217    }
218    mode |= generic_type_table[gt].mode;
219    rc = cpio_mkgeneric(name, mode, uid, gid);
220 fail:
221    return rc;
222}
223
224static int cpio_mkdir_line(const char *line)
225{
226    return cpio_mkgeneric_line(line, GT_DIR);
227}
228
229static int cpio_mkpipe_line(const char *line)
230{
231    return cpio_mkgeneric_line(line, GT_PIPE);
232}
233
234static int cpio_mksock_line(const char *line)
235{
236    return cpio_mkgeneric_line(line, GT_SOCK);
237}
238
239static int cpio_mknod(const char *name, unsigned int mode,
240               uid_t uid, gid_t gid, char dev_type,
241               unsigned int maj, unsigned int min)
242{
243    char s[256];
244
245    if (dev_type == 'b')
246        mode |= S_IFBLK;
247    else
248        mode |= S_IFCHR;
249
250    if (name[0] == '/')
251        name++;
252    sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
253           "%08X%08X%08X%08X%08X%08X%08X",
254        "070701", /* magic */
255        ino++, /* ino */
256        mode, /* mode */
257        (long) uid, /* uid */
258        (long) gid, /* gid */
259        1, /* nlink */
260        (long) default_mtime, /* mtime */
261        0, /* filesize */
262        3, /* major */
263        1, /* minor */
264        maj, /* rmajor */
265        min, /* rminor */
266        (unsigned)strlen(name) + 1,/* namesize */
267        0); /* chksum */
268    push_hdr(s);
269    push_rest(name);
270    return 0;
271}
272
273static int cpio_mknod_line(const char *line)
274{
275    char name[PATH_MAX + 1];
276    unsigned int mode;
277    int uid;
278    int gid;
279    char dev_type;
280    unsigned int maj;
281    unsigned int min;
282    int rc = -1;
283
284    if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
285             name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
286        fprintf(stderr, "Unrecognized nod format '%s'", line);
287        goto fail;
288    }
289    rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
290 fail:
291    return rc;
292}
293
294static int cpio_mkfile(const char *name, const char *location,
295            unsigned int mode, uid_t uid, gid_t gid,
296            unsigned int nlinks)
297{
298    char s[256];
299    char *filebuf = NULL;
300    struct stat buf;
301    long size;
302    int file = -1;
303    int retval;
304    int rc = -1;
305    int namesize;
306    int i;
307
308    mode |= S_IFREG;
309
310    file = open (location, O_RDONLY);
311    if (file < 0) {
312        fprintf (stderr, "File %s could not be opened for reading\n", location);
313        goto error;
314    }
315
316    retval = fstat(file, &buf);
317    if (retval) {
318        fprintf(stderr, "File %s could not be stat()'ed\n", location);
319        goto error;
320    }
321
322    filebuf = malloc(buf.st_size);
323    if (!filebuf) {
324        fprintf (stderr, "out of memory\n");
325        goto error;
326    }
327
328    retval = read (file, filebuf, buf.st_size);
329    if (retval < 0) {
330        fprintf (stderr, "Can not read %s file\n", location);
331        goto error;
332    }
333
334    size = 0;
335    for (i = 1; i <= nlinks; i++) {
336        /* data goes on last link */
337        if (i == nlinks) size = buf.st_size;
338
339        if (name[0] == '/')
340            name++;
341        namesize = strlen(name) + 1;
342        sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
343               "%08lX%08X%08X%08X%08X%08X%08X",
344            "070701", /* magic */
345            ino, /* ino */
346            mode, /* mode */
347            (long) uid, /* uid */
348            (long) gid, /* gid */
349            nlinks, /* nlink */
350            (long) buf.st_mtime, /* mtime */
351            size, /* filesize */
352            3, /* major */
353            1, /* minor */
354            0, /* rmajor */
355            0, /* rminor */
356            namesize, /* namesize */
357            0); /* chksum */
358        push_hdr(s);
359        push_string(name);
360        push_pad();
361
362        if (size) {
363            if (fwrite(filebuf, size, 1, stdout) != 1) {
364                fprintf(stderr, "writing filebuf failed\n");
365                goto error;
366            }
367            offset += size;
368            push_pad();
369        }
370
371        name += namesize;
372    }
373    ino++;
374    rc = 0;
375    
376error:
377    if (filebuf) free(filebuf);
378    if (file >= 0) close(file);
379    return rc;
380}
381
382static char *cpio_replace_env(char *new_location)
383{
384       char expanded[PATH_MAX + 1];
385       char env_var[PATH_MAX + 1];
386       char *start;
387       char *end;
388
389       for (start = NULL; (start = strstr(new_location, "${")); ) {
390               end = strchr(start, '}');
391               if (start < end) {
392                       *env_var = *expanded = '\0';
393                       strncat(env_var, start + 2, end - start - 2);
394                       strncat(expanded, new_location, start - new_location);
395                       strncat(expanded, getenv(env_var), PATH_MAX);
396                       strncat(expanded, end + 1, PATH_MAX);
397                       strncpy(new_location, expanded, PATH_MAX);
398               } else
399                       break;
400       }
401
402       return new_location;
403}
404
405
406static int cpio_mkfile_line(const char *line)
407{
408    char name[PATH_MAX + 1];
409    char *dname = NULL; /* malloc'ed buffer for hard links */
410    char location[PATH_MAX + 1];
411    unsigned int mode;
412    int uid;
413    int gid;
414    int nlinks = 1;
415    int end = 0, dname_len = 0;
416    int rc = -1;
417
418    if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
419                "s %o %d %d %n",
420                name, location, &mode, &uid, &gid, &end)) {
421        fprintf(stderr, "Unrecognized file format '%s'", line);
422        goto fail;
423    }
424    if (end && isgraph(line[end])) {
425        int len;
426        int nend;
427
428        dname = malloc(strlen(line));
429        if (!dname) {
430            fprintf (stderr, "out of memory (%d)\n", dname_len);
431            goto fail;
432        }
433
434        dname_len = strlen(name) + 1;
435        memcpy(dname, name, dname_len);
436
437        do {
438            nend = 0;
439            if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
440                    name, &nend) < 1)
441                break;
442            len = strlen(name) + 1;
443            memcpy(dname + dname_len, name, len);
444            dname_len += len;
445            nlinks++;
446            end += nend;
447        } while (isgraph(line[end]));
448    } else {
449        dname = name;
450    }
451    rc = cpio_mkfile(dname, cpio_replace_env(location),
452                     mode, uid, gid, nlinks);
453 fail:
454    if (dname_len) free(dname);
455    return rc;
456}
457
458static void usage(const char *prog)
459{
460    fprintf(stderr, "Usage:\n"
461        "\t%s [-t <timestamp>] <cpio_list>\n"
462        "\n"
463        "<cpio_list> is a file containing newline separated entries that\n"
464        "describe the files to be included in the initramfs archive:\n"
465        "\n"
466        "# a comment\n"
467        "file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
468        "dir <name> <mode> <uid> <gid>\n"
469        "nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
470        "slink <name> <target> <mode> <uid> <gid>\n"
471        "pipe <name> <mode> <uid> <gid>\n"
472        "sock <name> <mode> <uid> <gid>\n"
473        "\n"
474        "<name> name of the file/dir/nod/etc in the archive\n"
475        "<location> location of the file in the current filesystem\n"
476        " expands shell variables quoted with ${}\n"
477        "<target> link target\n"
478        "<mode> mode/permissions of the file\n"
479        "<uid> user id (0=root)\n"
480        "<gid> group id (0=root)\n"
481        "<dev_type> device type (b=block, c=character)\n"
482        "<maj> major number of nod\n"
483        "<min> minor number of nod\n"
484        "<hard links> space separated list of other links to file\n"
485        "\n"
486        "example:\n"
487        "# A simple initramfs\n"
488        "dir /dev 0755 0 0\n"
489        "nod /dev/console 0600 0 0 c 5 1\n"
490        "dir /root 0700 0 0\n"
491        "dir /sbin 0755 0 0\n"
492        "file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
493        "\n"
494        "<timestamp> is time in seconds since Epoch that will be used\n"
495        "as mtime for symlinks, special files and directories. The default\n"
496        "is to use the current time for these entries.\n",
497        prog);
498}
499
500struct file_handler file_handler_table[] = {
501    {
502        .type = "file",
503        .handler = cpio_mkfile_line,
504    }, {
505        .type = "nod",
506        .handler = cpio_mknod_line,
507    }, {
508        .type = "dir",
509        .handler = cpio_mkdir_line,
510    }, {
511        .type = "slink",
512        .handler = cpio_mkslink_line,
513    }, {
514        .type = "pipe",
515        .handler = cpio_mkpipe_line,
516    }, {
517        .type = "sock",
518        .handler = cpio_mksock_line,
519    }, {
520        .type = NULL,
521        .handler = NULL,
522    }
523};
524
525#define LINE_SIZE (2 * PATH_MAX + 50)
526
527int main (int argc, char *argv[])
528{
529    FILE *cpio_list;
530    char line[LINE_SIZE];
531    char *args, *type;
532    int ec = 0;
533    int line_nr = 0;
534    const char *filename;
535
536    default_mtime = time(NULL);
537    while (1) {
538        int opt = getopt(argc, argv, "t:h");
539        char *invalid;
540
541        if (opt == -1)
542            break;
543        switch (opt) {
544        case 't':
545            default_mtime = strtol(optarg, &invalid, 10);
546            if (!*optarg || *invalid) {
547                fprintf(stderr, "Invalid timestamp: %s\n",
548                        optarg);
549                usage(argv[0]);
550                exit(1);
551            }
552            break;
553        case 'h':
554        case '?':
555            usage(argv[0]);
556            exit(opt == 'h' ? 0 : 1);
557        }
558    }
559
560    if (argc - optind != 1) {
561        usage(argv[0]);
562        exit(1);
563    }
564    filename = argv[optind];
565    if (!strcmp(filename, "-"))
566        cpio_list = stdin;
567    else if (!(cpio_list = fopen(filename, "r"))) {
568        fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
569            filename, strerror(errno));
570        usage(argv[0]);
571        exit(1);
572    }
573
574    while (fgets(line, LINE_SIZE, cpio_list)) {
575        int type_idx;
576        size_t slen = strlen(line);
577
578        line_nr++;
579
580        if ('#' == *line) {
581            /* comment - skip to next line */
582            continue;
583        }
584
585        if (! (type = strtok(line, " \t"))) {
586            fprintf(stderr,
587                "ERROR: incorrect format, could not locate file type line %d: '%s'\n",
588                line_nr, line);
589            ec = -1;
590            break;
591        }
592
593        if ('\n' == *type) {
594            /* a blank line */
595            continue;
596        }
597
598        if (slen == strlen(type)) {
599            /* must be an empty line */
600            continue;
601        }
602
603        if (! (args = strtok(NULL, "\n"))) {
604            fprintf(stderr,
605                "ERROR: incorrect format, newline required line %d: '%s'\n",
606                line_nr, line);
607            ec = -1;
608        }
609
610        for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
611            int rc;
612            if (! strcmp(line, file_handler_table[type_idx].type)) {
613                if ((rc = file_handler_table[type_idx].handler(args))) {
614                    ec = rc;
615                    fprintf(stderr, " line %d\n", line_nr);
616                }
617                break;
618            }
619        }
620
621        if (NULL == file_handler_table[type_idx].type) {
622            fprintf(stderr, "unknown file type line %d: '%s'\n",
623                line_nr, line);
624        }
625    }
626    if (ec == 0)
627        cpio_trailer();
628
629    exit(ec);
630}
631

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