1// SPDX-License-Identifier: GPL-2.0
2#include <stdio.h>
3#include <stdlib.h>
4#include <stdint.h>
5#include <stdbool.h>
6#include <sys/types.h>
7#include <sys/stat.h>
8#include <string.h>
9#include <unistd.h>
10#include <time.h>
11#include <fcntl.h>
12#include <errno.h>
13#include <ctype.h>
14#include <limits.h>
15
16/*
17 * Original work by Jeff Garzik
18 *
19 * External file lists, symlink, pipe and fifo support by Thayne Harbaugh
20 * Hard link support by Luciano Rocha
21 */
22
23#define xstr(s) #s
24#define str(s) xstr(s)
25#define MIN(a, b) ((a) < (b) ? (a) : (b))
26
27static unsigned int offset;
28static unsigned int ino = 721;
29static time_t default_mtime;
30static bool do_file_mtime;
31static bool do_csum = false;
32
33struct file_handler {
34	const char *type;
35	int (*handler)(const char *line);
36};
37
38static void push_string(const char *name)
39{
40	unsigned int name_len = strlen(name) + 1;
41
42	fputs(name, stdout);
43	putchar(0);
44	offset += name_len;
45}
46
47static void push_pad (void)
48{
49	while (offset & 3) {
50		putchar(0);
51		offset++;
52	}
53}
54
55static void push_rest(const char *name)
56{
57	unsigned int name_len = strlen(name) + 1;
58	unsigned int tmp_ofs;
59
60	fputs(name, stdout);
61	putchar(0);
62	offset += name_len;
63
64	tmp_ofs = name_len + 110;
65	while (tmp_ofs & 3) {
66		putchar(0);
67		offset++;
68		tmp_ofs++;
69	}
70}
71
72static void push_hdr(const char *s)
73{
74	fputs(s, stdout);
75	offset += 110;
76}
77
78static void cpio_trailer(void)
79{
80	char s[256];
81	const char name[] = "TRAILER!!!";
82
83	sprintf(s, "%s%08X%08X%08lX%08lX%08X%08lX"
84	       "%08X%08X%08X%08X%08X%08X%08X",
85		do_csum ? "070702" : "070701", /* magic */
86		0,			/* ino */
87		0,			/* mode */
88		(long) 0,		/* uid */
89		(long) 0,		/* gid */
90		1,			/* nlink */
91		(long) 0,		/* mtime */
92		0,			/* filesize */
93		0,			/* major */
94		0,			/* minor */
95		0,			/* rmajor */
96		0,			/* rminor */
97		(unsigned)strlen(name)+1, /* namesize */
98		0);			/* chksum */
99	push_hdr(s);
100	push_rest(name);
101
102	while (offset % 512) {
103		putchar(0);
104		offset++;
105	}
106}
107
108static int cpio_mkslink(const char *name, const char *target,
109			 unsigned int mode, uid_t uid, gid_t gid)
110{
111	char s[256];
112
113	if (name[0] == '/')
114		name++;
115	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
116	       "%08X%08X%08X%08X%08X%08X%08X",
117		do_csum ? "070702" : "070701", /* magic */
118		ino++,			/* ino */
119		S_IFLNK | mode,		/* mode */
120		(long) uid,		/* uid */
121		(long) gid,		/* gid */
122		1,			/* nlink */
123		(long) default_mtime,	/* mtime */
124		(unsigned)strlen(target)+1, /* filesize */
125		3,			/* major */
126		1,			/* minor */
127		0,			/* rmajor */
128		0,			/* rminor */
129		(unsigned)strlen(name) + 1,/* namesize */
130		0);			/* chksum */
131	push_hdr(s);
132	push_string(name);
133	push_pad();
134	push_string(target);
135	push_pad();
136	return 0;
137}
138
139static int cpio_mkslink_line(const char *line)
140{
141	char name[PATH_MAX + 1];
142	char target[PATH_MAX + 1];
143	unsigned int mode;
144	int uid;
145	int gid;
146	int rc = -1;
147
148	if (5 != sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX) "s %o %d %d", name, target, &mode, &uid, &gid)) {
149		fprintf(stderr, "Unrecognized dir format '%s'", line);
150		goto fail;
151	}
152	rc = cpio_mkslink(name, target, mode, uid, gid);
153 fail:
154	return rc;
155}
156
157static int cpio_mkgeneric(const char *name, unsigned int mode,
158		       uid_t uid, gid_t gid)
159{
160	char s[256];
161
162	if (name[0] == '/')
163		name++;
164	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
165	       "%08X%08X%08X%08X%08X%08X%08X",
166		do_csum ? "070702" : "070701", /* magic */
167		ino++,			/* ino */
168		mode,			/* mode */
169		(long) uid,		/* uid */
170		(long) gid,		/* gid */
171		2,			/* nlink */
172		(long) default_mtime,	/* mtime */
173		0,			/* filesize */
174		3,			/* major */
175		1,			/* minor */
176		0,			/* rmajor */
177		0,			/* rminor */
178		(unsigned)strlen(name) + 1,/* namesize */
179		0);			/* chksum */
180	push_hdr(s);
181	push_rest(name);
182	return 0;
183}
184
185enum generic_types {
186	GT_DIR,
187	GT_PIPE,
188	GT_SOCK
189};
190
191struct generic_type {
192	const char *type;
193	mode_t mode;
194};
195
196static const struct generic_type generic_type_table[] = {
197	[GT_DIR] = {
198		.type = "dir",
199		.mode = S_IFDIR
200	},
201	[GT_PIPE] = {
202		.type = "pipe",
203		.mode = S_IFIFO
204	},
205	[GT_SOCK] = {
206		.type = "sock",
207		.mode = S_IFSOCK
208	}
209};
210
211static int cpio_mkgeneric_line(const char *line, enum generic_types gt)
212{
213	char name[PATH_MAX + 1];
214	unsigned int mode;
215	int uid;
216	int gid;
217	int rc = -1;
218
219	if (4 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d", name, &mode, &uid, &gid)) {
220		fprintf(stderr, "Unrecognized %s format '%s'",
221			line, generic_type_table[gt].type);
222		goto fail;
223	}
224	mode |= generic_type_table[gt].mode;
225	rc = cpio_mkgeneric(name, mode, uid, gid);
226 fail:
227	return rc;
228}
229
230static int cpio_mkdir_line(const char *line)
231{
232	return cpio_mkgeneric_line(line, GT_DIR);
233}
234
235static int cpio_mkpipe_line(const char *line)
236{
237	return cpio_mkgeneric_line(line, GT_PIPE);
238}
239
240static int cpio_mksock_line(const char *line)
241{
242	return cpio_mkgeneric_line(line, GT_SOCK);
243}
244
245static int cpio_mknod(const char *name, unsigned int mode,
246		       uid_t uid, gid_t gid, char dev_type,
247		       unsigned int maj, unsigned int min)
248{
249	char s[256];
250
251	if (dev_type == 'b')
252		mode |= S_IFBLK;
253	else
254		mode |= S_IFCHR;
255
256	if (name[0] == '/')
257		name++;
258	sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
259	       "%08X%08X%08X%08X%08X%08X%08X",
260		do_csum ? "070702" : "070701", /* magic */
261		ino++,			/* ino */
262		mode,			/* mode */
263		(long) uid,		/* uid */
264		(long) gid,		/* gid */
265		1,			/* nlink */
266		(long) default_mtime,	/* mtime */
267		0,			/* filesize */
268		3,			/* major */
269		1,			/* minor */
270		maj,			/* rmajor */
271		min,			/* rminor */
272		(unsigned)strlen(name) + 1,/* namesize */
273		0);			/* chksum */
274	push_hdr(s);
275	push_rest(name);
276	return 0;
277}
278
279static int cpio_mknod_line(const char *line)
280{
281	char name[PATH_MAX + 1];
282	unsigned int mode;
283	int uid;
284	int gid;
285	char dev_type;
286	unsigned int maj;
287	unsigned int min;
288	int rc = -1;
289
290	if (7 != sscanf(line, "%" str(PATH_MAX) "s %o %d %d %c %u %u",
291			 name, &mode, &uid, &gid, &dev_type, &maj, &min)) {
292		fprintf(stderr, "Unrecognized nod format '%s'", line);
293		goto fail;
294	}
295	rc = cpio_mknod(name, mode, uid, gid, dev_type, maj, min);
296 fail:
297	return rc;
298}
299
300static int cpio_mkfile_csum(int fd, unsigned long size, uint32_t *csum)
301{
302	while (size) {
303		unsigned char filebuf[65536];
304		ssize_t this_read;
305		size_t i, this_size = MIN(size, sizeof(filebuf));
306
307		this_read = read(fd, filebuf, this_size);
308		if (this_read <= 0 || this_read > this_size)
309			return -1;
310
311		for (i = 0; i < this_read; i++)
312			*csum += filebuf[i];
313
314		size -= this_read;
315	}
316	/* seek back to the start for data segment I/O */
317	if (lseek(fd, 0, SEEK_SET) < 0)
318		return -1;
319
320	return 0;
321}
322
323static int cpio_mkfile(const char *name, const char *location,
324			unsigned int mode, uid_t uid, gid_t gid,
325			unsigned int nlinks)
326{
327	char s[256];
328	struct stat buf;
329	unsigned long size;
330	int file;
331	int retval;
332	int rc = -1;
333	time_t mtime;
334	int namesize;
335	unsigned int i;
336	uint32_t csum = 0;
337
338	mode |= S_IFREG;
339
340	file = open (location, O_RDONLY);
341	if (file < 0) {
342		fprintf (stderr, "File %s could not be opened for reading\n", location);
343		goto error;
344	}
345
346	retval = fstat(file, &buf);
347	if (retval) {
348		fprintf(stderr, "File %s could not be stat()'ed\n", location);
349		goto error;
350	}
351
352	if (do_file_mtime) {
353		mtime = default_mtime;
354	} else {
355		mtime = buf.st_mtime;
356		if (mtime > 0xffffffff) {
357			fprintf(stderr, "%s: Timestamp exceeds maximum cpio timestamp, clipping.\n",
358					location);
359			mtime = 0xffffffff;
360		}
361
362		if (mtime < 0) {
363			fprintf(stderr, "%s: Timestamp negative, clipping.\n",
364					location);
365			mtime = 0;
366		}
367	}
368
369	if (buf.st_size > 0xffffffff) {
370		fprintf(stderr, "%s: Size exceeds maximum cpio file size\n",
371			location);
372		goto error;
373	}
374
375	if (do_csum && cpio_mkfile_csum(file, buf.st_size, &csum) < 0) {
376		fprintf(stderr, "Failed to checksum file %s\n", location);
377		goto error;
378	}
379
380	size = 0;
381	for (i = 1; i <= nlinks; i++) {
382		/* data goes on last link */
383		if (i == nlinks)
384			size = buf.st_size;
385
386		if (name[0] == '/')
387			name++;
388		namesize = strlen(name) + 1;
389		sprintf(s,"%s%08X%08X%08lX%08lX%08X%08lX"
390		       "%08lX%08X%08X%08X%08X%08X%08X",
391			do_csum ? "070702" : "070701", /* magic */
392			ino,			/* ino */
393			mode,			/* mode */
394			(long) uid,		/* uid */
395			(long) gid,		/* gid */
396			nlinks,			/* nlink */
397			(long) mtime,		/* mtime */
398			size,			/* filesize */
399			3,			/* major */
400			1,			/* minor */
401			0,			/* rmajor */
402			0,			/* rminor */
403			namesize,		/* namesize */
404			size ? csum : 0);	/* chksum */
405		push_hdr(s);
406		push_string(name);
407		push_pad();
408
409		while (size) {
410			unsigned char filebuf[65536];
411			ssize_t this_read;
412			size_t this_size = MIN(size, sizeof(filebuf));
413
414			this_read = read(file, filebuf, this_size);
415			if (this_read <= 0 || this_read > this_size) {
416				fprintf(stderr, "Can not read %s file\n", location);
417				goto error;
418			}
419
420			if (fwrite(filebuf, this_read, 1, stdout) != 1) {
421				fprintf(stderr, "writing filebuf failed\n");
422				goto error;
423			}
424			offset += this_read;
425			size -= this_read;
426		}
427		push_pad();
428
429		name += namesize;
430	}
431	ino++;
432	rc = 0;
433
434error:
435	if (file >= 0)
436		close(file);
437	return rc;
438}
439
440static char *cpio_replace_env(char *new_location)
441{
442	char expanded[PATH_MAX + 1];
443	char *start, *end, *var;
444
445	while ((start = strstr(new_location, "${")) &&
446	       (end = strchr(start + 2, '}'))) {
447		*start = *end = 0;
448		var = getenv(start + 2);
449		snprintf(expanded, sizeof expanded, "%s%s%s",
450			 new_location, var ? var : "", end + 1);
451		strcpy(new_location, expanded);
452	}
453
454	return new_location;
455}
456
457static int cpio_mkfile_line(const char *line)
458{
459	char name[PATH_MAX + 1];
460	char *dname = NULL; /* malloc'ed buffer for hard links */
461	char location[PATH_MAX + 1];
462	unsigned int mode;
463	int uid;
464	int gid;
465	int nlinks = 1;
466	int end = 0, dname_len = 0;
467	int rc = -1;
468
469	if (5 > sscanf(line, "%" str(PATH_MAX) "s %" str(PATH_MAX)
470				"s %o %d %d %n",
471				name, location, &mode, &uid, &gid, &end)) {
472		fprintf(stderr, "Unrecognized file format '%s'", line);
473		goto fail;
474	}
475	if (end && isgraph(line[end])) {
476		int len;
477		int nend;
478
479		dname = malloc(strlen(line));
480		if (!dname) {
481			fprintf (stderr, "out of memory (%d)\n", dname_len);
482			goto fail;
483		}
484
485		dname_len = strlen(name) + 1;
486		memcpy(dname, name, dname_len);
487
488		do {
489			nend = 0;
490			if (sscanf(line + end, "%" str(PATH_MAX) "s %n",
491					name, &nend) < 1)
492				break;
493			len = strlen(name) + 1;
494			memcpy(dname + dname_len, name, len);
495			dname_len += len;
496			nlinks++;
497			end += nend;
498		} while (isgraph(line[end]));
499	} else {
500		dname = name;
501	}
502	rc = cpio_mkfile(dname, cpio_replace_env(location),
503	                 mode, uid, gid, nlinks);
504 fail:
505	if (dname_len) free(dname);
506	return rc;
507}
508
509static void usage(const char *prog)
510{
511	fprintf(stderr, "Usage:\n"
512		"\t%s [-t <timestamp>] [-c] <cpio_list>\n"
513		"\n"
514		"<cpio_list> is a file containing newline separated entries that\n"
515		"describe the files to be included in the initramfs archive:\n"
516		"\n"
517		"# a comment\n"
518		"file <name> <location> <mode> <uid> <gid> [<hard links>]\n"
519		"dir <name> <mode> <uid> <gid>\n"
520		"nod <name> <mode> <uid> <gid> <dev_type> <maj> <min>\n"
521		"slink <name> <target> <mode> <uid> <gid>\n"
522		"pipe <name> <mode> <uid> <gid>\n"
523		"sock <name> <mode> <uid> <gid>\n"
524		"\n"
525		"<name>       name of the file/dir/nod/etc in the archive\n"
526		"<location>   location of the file in the current filesystem\n"
527		"             expands shell variables quoted with ${}\n"
528		"<target>     link target\n"
529		"<mode>       mode/permissions of the file\n"
530		"<uid>        user id (0=root)\n"
531		"<gid>        group id (0=root)\n"
532		"<dev_type>   device type (b=block, c=character)\n"
533		"<maj>        major number of nod\n"
534		"<min>        minor number of nod\n"
535		"<hard links> space separated list of other links to file\n"
536		"\n"
537		"example:\n"
538		"# A simple initramfs\n"
539		"dir /dev 0755 0 0\n"
540		"nod /dev/console 0600 0 0 c 5 1\n"
541		"dir /root 0700 0 0\n"
542		"dir /sbin 0755 0 0\n"
543		"file /sbin/kinit /usr/src/klibc/kinit/kinit 0755 0 0\n"
544		"\n"
545		"<timestamp> is time in seconds since Epoch that will be used\n"
546		"as mtime for symlinks, directories, regular and special files.\n"
547		"The default is to use the current time for all files, but\n"
548		"preserve modification time for regular files.\n"
549		"-c: calculate and store 32-bit checksums for file data.\n",
550		prog);
551}
552
553static const struct file_handler file_handler_table[] = {
554	{
555		.type    = "file",
556		.handler = cpio_mkfile_line,
557	}, {
558		.type    = "nod",
559		.handler = cpio_mknod_line,
560	}, {
561		.type    = "dir",
562		.handler = cpio_mkdir_line,
563	}, {
564		.type    = "slink",
565		.handler = cpio_mkslink_line,
566	}, {
567		.type    = "pipe",
568		.handler = cpio_mkpipe_line,
569	}, {
570		.type    = "sock",
571		.handler = cpio_mksock_line,
572	}, {
573		.type    = NULL,
574		.handler = NULL,
575	}
576};
577
578#define LINE_SIZE (2 * PATH_MAX + 50)
579
580int main (int argc, char *argv[])
581{
582	FILE *cpio_list;
583	char line[LINE_SIZE];
584	char *args, *type;
585	int ec = 0;
586	int line_nr = 0;
587	const char *filename;
588
589	default_mtime = time(NULL);
590	while (1) {
591		int opt = getopt(argc, argv, "t:ch");
592		char *invalid;
593
594		if (opt == -1)
595			break;
596		switch (opt) {
597		case 't':
598			default_mtime = strtol(optarg, &invalid, 10);
599			if (!*optarg || *invalid) {
600				fprintf(stderr, "Invalid timestamp: %s\n",
601						optarg);
602				usage(argv[0]);
603				exit(1);
604			}
605			do_file_mtime = true;
606			break;
607		case 'c':
608			do_csum = true;
609			break;
610		case 'h':
611		case '?':
612			usage(argv[0]);
613			exit(opt == 'h' ? 0 : 1);
614		}
615	}
616
617	/*
618	 * Timestamps after 2106-02-07 06:28:15 UTC have an ascii hex time_t
619	 * representation that exceeds 8 chars and breaks the cpio header
620	 * specification. Negative timestamps similarly exceed 8 chars.
621	 */
622	if (default_mtime > 0xffffffff || default_mtime < 0) {
623		fprintf(stderr, "ERROR: Timestamp out of range for cpio format\n");
624		exit(1);
625	}
626
627	if (argc - optind != 1) {
628		usage(argv[0]);
629		exit(1);
630	}
631	filename = argv[optind];
632	if (!strcmp(filename, "-"))
633		cpio_list = stdin;
634	else if (!(cpio_list = fopen(filename, "r"))) {
635		fprintf(stderr, "ERROR: unable to open '%s': %s\n\n",
636			filename, strerror(errno));
637		usage(argv[0]);
638		exit(1);
639	}
640
641	while (fgets(line, LINE_SIZE, cpio_list)) {
642		int type_idx;
643		size_t slen = strlen(line);
644
645		line_nr++;
646
647		if ('#' == *line) {
648			/* comment - skip to next line */
649			continue;
650		}
651
652		if (! (type = strtok(line, " \t"))) {
653			fprintf(stderr,
654				"ERROR: incorrect format, could not locate file type line %d: '%s'\n",
655				line_nr, line);
656			ec = -1;
657			break;
658		}
659
660		if ('\n' == *type) {
661			/* a blank line */
662			continue;
663		}
664
665		if (slen == strlen(type)) {
666			/* must be an empty line */
667			continue;
668		}
669
670		if (! (args = strtok(NULL, "\n"))) {
671			fprintf(stderr,
672				"ERROR: incorrect format, newline required line %d: '%s'\n",
673				line_nr, line);
674			ec = -1;
675		}
676
677		for (type_idx = 0; file_handler_table[type_idx].type; type_idx++) {
678			int rc;
679			if (! strcmp(line, file_handler_table[type_idx].type)) {
680				if ((rc = file_handler_table[type_idx].handler(args))) {
681					ec = rc;
682					fprintf(stderr, " line %d\n", line_nr);
683				}
684				break;
685			}
686		}
687
688		if (NULL == file_handler_table[type_idx].type) {
689			fprintf(stderr, "unknown file type line %d: '%s'\n",
690				line_nr, line);
691		}
692	}
693	if (ec == 0)
694		cpio_trailer();
695
696	exit(ec);
697}
698