1#include <linux/init.h>
2#include <linux/fs.h>
3#include <linux/slab.h>
4#include <linux/types.h>
5#include <linux/fcntl.h>
6#include <linux/delay.h>
7#include <linux/string.h>
8#include <linux/dirent.h>
9#include <linux/syscalls.h>
10#include <linux/utime.h>
11
12static __initdata char *message;
13static void __init error(char *x)
14{
15	if (!message)
16		message = x;
17}
18
19/* link hash */
20
21#define N_ALIGN(len) ((((len) + 1) & ~3) + 2)
22
23static __initdata struct hash {
24	int ino, minor, major;
25	mode_t mode;
26	struct hash *next;
27	char name[N_ALIGN(PATH_MAX)];
28} *head[32];
29
30static inline int hash(int major, int minor, int ino)
31{
32	unsigned long tmp = ino + minor + (major << 3);
33	tmp += tmp >> 5;
34	return tmp & 31;
35}
36
37static char __init *find_link(int major, int minor, int ino,
38			      mode_t mode, char *name)
39{
40	struct hash **p, *q;
41	for (p = head + hash(major, minor, ino); *p; p = &(*p)->next) {
42		if ((*p)->ino != ino)
43			continue;
44		if ((*p)->minor != minor)
45			continue;
46		if ((*p)->major != major)
47			continue;
48		if (((*p)->mode ^ mode) & S_IFMT)
49			continue;
50		return (*p)->name;
51	}
52	q = kmalloc(sizeof(struct hash), GFP_KERNEL);
53	if (!q)
54		panic("can't allocate link hash entry");
55	q->major = major;
56	q->minor = minor;
57	q->ino = ino;
58	q->mode = mode;
59	strcpy(q->name, name);
60	q->next = NULL;
61	*p = q;
62	return NULL;
63}
64
65static void __init free_hash(void)
66{
67	struct hash **p, *q;
68	for (p = head; p < head + 32; p++) {
69		while (*p) {
70			q = *p;
71			*p = q->next;
72			kfree(q);
73		}
74	}
75}
76
77static long __init do_utime(char __user *filename, time_t mtime)
78{
79	struct timespec t[2];
80
81	t[0].tv_sec = mtime;
82	t[0].tv_nsec = 0;
83	t[1].tv_sec = mtime;
84	t[1].tv_nsec = 0;
85
86	return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
87}
88
89static __initdata LIST_HEAD(dir_list);
90struct dir_entry {
91	struct list_head list;
92	char *name;
93	time_t mtime;
94};
95
96static void __init dir_add(const char *name, time_t mtime)
97{
98	struct dir_entry *de = kmalloc(sizeof(struct dir_entry), GFP_KERNEL);
99	if (!de)
100		panic("can't allocate dir_entry buffer");
101	INIT_LIST_HEAD(&de->list);
102	de->name = kstrdup(name, GFP_KERNEL);
103	de->mtime = mtime;
104	list_add(&de->list, &dir_list);
105}
106
107static void __init dir_utime(void)
108{
109	struct dir_entry *de, *tmp;
110	list_for_each_entry_safe(de, tmp, &dir_list, list) {
111		list_del(&de->list);
112		do_utime(de->name, de->mtime);
113		kfree(de->name);
114		kfree(de);
115	}
116}
117
118static __initdata time_t mtime;
119
120/* cpio header parsing */
121
122static __initdata unsigned long ino, major, minor, nlink;
123static __initdata mode_t mode;
124static __initdata unsigned long body_len, name_len;
125static __initdata uid_t uid;
126static __initdata gid_t gid;
127static __initdata unsigned rdev;
128
129static void __init parse_header(char *s)
130{
131	unsigned long parsed[12];
132	char buf[9];
133	int i;
134
135	buf[8] = '\0';
136	for (i = 0, s += 6; i < 12; i++, s += 8) {
137		memcpy(buf, s, 8);
138		parsed[i] = simple_strtoul(buf, NULL, 16);
139	}
140	ino = parsed[0];
141	mode = parsed[1];
142	uid = parsed[2];
143	gid = parsed[3];
144	nlink = parsed[4];
145	mtime = parsed[5];
146	body_len = parsed[6];
147	major = parsed[7];
148	minor = parsed[8];
149	rdev = new_encode_dev(MKDEV(parsed[9], parsed[10]));
150	name_len = parsed[11];
151}
152
153/* FSM */
154
155static __initdata enum state {
156	Start,
157	Collect,
158	GotHeader,
159	SkipIt,
160	GotName,
161	CopyFile,
162	GotSymlink,
163	Reset
164} state, next_state;
165
166static __initdata char *victim;
167static __initdata unsigned count;
168static __initdata loff_t this_header, next_header;
169
170static inline void __init eat(unsigned n)
171{
172	victim += n;
173	this_header += n;
174	count -= n;
175}
176
177static __initdata char *vcollected;
178static __initdata char *collected;
179static __initdata int remains;
180static __initdata char *collect;
181
182static void __init read_into(char *buf, unsigned size, enum state next)
183{
184	if (count >= size) {
185		collected = victim;
186		eat(size);
187		state = next;
188	} else {
189		collect = collected = buf;
190		remains = size;
191		next_state = next;
192		state = Collect;
193	}
194}
195
196static __initdata char *header_buf, *symlink_buf, *name_buf;
197
198static int __init do_start(void)
199{
200	read_into(header_buf, 110, GotHeader);
201	return 0;
202}
203
204static int __init do_collect(void)
205{
206	unsigned n = remains;
207	if (count < n)
208		n = count;
209	memcpy(collect, victim, n);
210	eat(n);
211	collect += n;
212	if ((remains -= n) != 0)
213		return 1;
214	state = next_state;
215	return 0;
216}
217
218static int __init do_header(void)
219{
220	if (memcmp(collected, "070707", 6)==0) {
221		error("incorrect cpio method used: use -H newc option");
222		return 1;
223	}
224	if (memcmp(collected, "070701", 6)) {
225		error("no cpio magic");
226		return 1;
227	}
228	parse_header(collected);
229	next_header = this_header + N_ALIGN(name_len) + body_len;
230	next_header = (next_header + 3) & ~3;
231	state = SkipIt;
232	if (name_len <= 0 || name_len > PATH_MAX)
233		return 0;
234	if (S_ISLNK(mode)) {
235		if (body_len > PATH_MAX)
236			return 0;
237		collect = collected = symlink_buf;
238		remains = N_ALIGN(name_len) + body_len;
239		next_state = GotSymlink;
240		state = Collect;
241		return 0;
242	}
243	if (S_ISREG(mode) || !body_len)
244		read_into(name_buf, N_ALIGN(name_len), GotName);
245	return 0;
246}
247
248static int __init do_skip(void)
249{
250	if (this_header + count < next_header) {
251		eat(count);
252		return 1;
253	} else {
254		eat(next_header - this_header);
255		state = next_state;
256		return 0;
257	}
258}
259
260static int __init do_reset(void)
261{
262	while(count && *victim == '\0')
263		eat(1);
264	if (count && (this_header & 3))
265		error("broken padding");
266	return 1;
267}
268
269static int __init maybe_link(void)
270{
271	if (nlink >= 2) {
272		char *old = find_link(major, minor, ino, mode, collected);
273		if (old)
274			return (sys_link(old, collected) < 0) ? -1 : 1;
275	}
276	return 0;
277}
278
279static void __init clean_path(char *path, mode_t mode)
280{
281	struct stat st;
282
283	if (!sys_newlstat(path, &st) && (st.st_mode^mode) & S_IFMT) {
284		if (S_ISDIR(st.st_mode))
285			sys_rmdir(path);
286		else
287			sys_unlink(path);
288	}
289}
290
291static __initdata int wfd;
292
293static int __init do_name(void)
294{
295	state = SkipIt;
296	next_state = Reset;
297	if (strcmp(collected, "TRAILER!!!") == 0) {
298		free_hash();
299		return 0;
300	}
301	clean_path(collected, mode);
302	if (S_ISREG(mode)) {
303		int ml = maybe_link();
304		if (ml >= 0) {
305			int openflags = O_WRONLY|O_CREAT;
306			if (ml != 1)
307				openflags |= O_TRUNC;
308			wfd = sys_open(collected, openflags, mode);
309
310			if (wfd >= 0) {
311				sys_fchown(wfd, uid, gid);
312				sys_fchmod(wfd, mode);
313				if (body_len)
314					sys_ftruncate(wfd, body_len);
315				vcollected = kstrdup(collected, GFP_KERNEL);
316				state = CopyFile;
317			}
318		}
319	} else if (S_ISDIR(mode)) {
320		sys_mkdir(collected, mode);
321		sys_chown(collected, uid, gid);
322		sys_chmod(collected, mode);
323		dir_add(collected, mtime);
324	} else if (S_ISBLK(mode) || S_ISCHR(mode) ||
325		   S_ISFIFO(mode) || S_ISSOCK(mode)) {
326		if (maybe_link() == 0) {
327			sys_mknod(collected, mode, rdev);
328			sys_chown(collected, uid, gid);
329			sys_chmod(collected, mode);
330			do_utime(collected, mtime);
331		}
332	}
333	return 0;
334}
335
336static int __init do_copy(void)
337{
338	if (count >= body_len) {
339		sys_write(wfd, victim, body_len);
340		sys_close(wfd);
341		do_utime(vcollected, mtime);
342		kfree(vcollected);
343		eat(body_len);
344		state = SkipIt;
345		return 0;
346	} else {
347		sys_write(wfd, victim, count);
348		body_len -= count;
349		eat(count);
350		return 1;
351	}
352}
353
354static int __init do_symlink(void)
355{
356	collected[N_ALIGN(name_len) + body_len] = '\0';
357	clean_path(collected, 0);
358	sys_symlink(collected + N_ALIGN(name_len), collected);
359	sys_lchown(collected, uid, gid);
360	do_utime(collected, mtime);
361	state = SkipIt;
362	next_state = Reset;
363	return 0;
364}
365
366static __initdata int (*actions[])(void) = {
367	[Start]		= do_start,
368	[Collect]	= do_collect,
369	[GotHeader]	= do_header,
370	[SkipIt]	= do_skip,
371	[GotName]	= do_name,
372	[CopyFile]	= do_copy,
373	[GotSymlink]	= do_symlink,
374	[Reset]		= do_reset,
375};
376
377static int __init write_buffer(char *buf, unsigned len)
378{
379	count = len;
380	victim = buf;
381
382	while (!actions[state]())
383		;
384	return len - count;
385}
386
387static int __init flush_buffer(void *bufv, unsigned len)
388{
389	char *buf = (char *) bufv;
390	int written;
391	int origLen = len;
392	if (message)
393		return -1;
394	while ((written = write_buffer(buf, len)) < len && !message) {
395		char c = buf[written];
396		if (c == '0') {
397			buf += written;
398			len -= written;
399			state = Start;
400		} else if (c == 0) {
401			buf += written;
402			len -= written;
403			state = Reset;
404		} else
405			error("junk in compressed archive");
406	}
407	return origLen;
408}
409
410static unsigned my_inptr;   /* index of next byte to be processed in inbuf */
411
412#include <linux/decompress/generic.h>
413
414static char * __init unpack_to_rootfs(char *buf, unsigned len)
415{
416	int written, res;
417	decompress_fn decompress;
418	const char *compress_name;
419	static __initdata char msg_buf[64];
420
421	header_buf = kmalloc(110, GFP_KERNEL);
422	symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL);
423	name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL);
424
425	if (!header_buf || !symlink_buf || !name_buf)
426		panic("can't allocate buffers");
427
428	state = Start;
429	this_header = 0;
430	message = NULL;
431	while (!message && len) {
432		loff_t saved_offset = this_header;
433		if (*buf == '0' && !(this_header & 3)) {
434			state = Start;
435			written = write_buffer(buf, len);
436			buf += written;
437			len -= written;
438			continue;
439		}
440		if (!*buf) {
441			buf++;
442			len--;
443			this_header++;
444			continue;
445		}
446		this_header = 0;
447		decompress = decompress_method(buf, len, &compress_name);
448		if (decompress) {
449			res = decompress(buf, len, NULL, flush_buffer, NULL,
450				   &my_inptr, error);
451			if (res)
452				error("decompressor failed");
453		} else if (compress_name) {
454			if (!message) {
455				snprintf(msg_buf, sizeof msg_buf,
456					 "compression method %s not configured",
457					 compress_name);
458				message = msg_buf;
459			}
460		} else
461			error("junk in compressed archive");
462		if (state != Reset)
463			error("junk in compressed archive");
464		this_header = saved_offset + my_inptr;
465		buf += my_inptr;
466		len -= my_inptr;
467	}
468	dir_utime();
469	kfree(name_buf);
470	kfree(symlink_buf);
471	kfree(header_buf);
472	return message;
473}
474
475static int __initdata do_retain_initrd;
476
477static int __init retain_initrd_param(char *str)
478{
479	if (*str)
480		return 0;
481	do_retain_initrd = 1;
482	return 1;
483}
484__setup("retain_initrd", retain_initrd_param);
485
486extern char __initramfs_start[], __initramfs_end[];
487#include <linux/initrd.h>
488#include <linux/kexec.h>
489
490static void __init free_initrd(void)
491{
492#ifdef CONFIG_KEXEC
493	unsigned long crashk_start = (unsigned long)__va(crashk_res.start);
494	unsigned long crashk_end   = (unsigned long)__va(crashk_res.end);
495#endif
496	if (do_retain_initrd)
497		goto skip;
498
499#ifdef CONFIG_KEXEC
500	/*
501	 * If the initrd region is overlapped with crashkernel reserved region,
502	 * free only memory that is not part of crashkernel region.
503	 */
504	if (initrd_start < crashk_end && initrd_end > crashk_start) {
505		/*
506		 * Initialize initrd memory region since the kexec boot does
507		 * not do.
508		 */
509		memset((void *)initrd_start, 0, initrd_end - initrd_start);
510		if (initrd_start < crashk_start)
511			free_initrd_mem(initrd_start, crashk_start);
512		if (initrd_end > crashk_end)
513			free_initrd_mem(crashk_end, initrd_end);
514	} else
515#endif
516		free_initrd_mem(initrd_start, initrd_end);
517skip:
518	initrd_start = 0;
519	initrd_end = 0;
520}
521
522#ifdef CONFIG_BLK_DEV_RAM
523#define BUF_SIZE 1024
524static void __init clean_rootfs(void)
525{
526	int fd;
527	void *buf;
528	struct linux_dirent64 *dirp;
529	int num;
530
531	fd = sys_open("/", O_RDONLY, 0);
532	WARN_ON(fd < 0);
533	if (fd < 0)
534		return;
535	buf = kzalloc(BUF_SIZE, GFP_KERNEL);
536	WARN_ON(!buf);
537	if (!buf) {
538		sys_close(fd);
539		return;
540	}
541
542	dirp = buf;
543	num = sys_getdents64(fd, dirp, BUF_SIZE);
544	while (num > 0) {
545		while (num > 0) {
546			struct stat st;
547			int ret;
548
549			ret = sys_newlstat(dirp->d_name, &st);
550			WARN_ON_ONCE(ret);
551			if (!ret) {
552				if (S_ISDIR(st.st_mode))
553					sys_rmdir(dirp->d_name);
554				else
555					sys_unlink(dirp->d_name);
556			}
557
558			num -= dirp->d_reclen;
559			dirp = (void *)dirp + dirp->d_reclen;
560		}
561		dirp = buf;
562		memset(buf, 0, BUF_SIZE);
563		num = sys_getdents64(fd, dirp, BUF_SIZE);
564	}
565
566	sys_close(fd);
567	kfree(buf);
568}
569#endif
570
571static int __init populate_rootfs(void)
572{
573	char *err = unpack_to_rootfs(__initramfs_start,
574			 __initramfs_end - __initramfs_start);
575	if (err)
576		panic(err);	/* Failed to decompress INTERNAL initramfs */
577	if (initrd_start) {
578#ifdef CONFIG_BLK_DEV_RAM
579		int fd;
580		printk(KERN_INFO "Trying to unpack rootfs image as initramfs...\n");
581		err = unpack_to_rootfs((char *)initrd_start,
582			initrd_end - initrd_start);
583		if (!err) {
584			free_initrd();
585			return 0;
586		} else {
587			clean_rootfs();
588			unpack_to_rootfs(__initramfs_start,
589				 __initramfs_end - __initramfs_start);
590		}
591		printk(KERN_INFO "rootfs image is not initramfs (%s)"
592				"; looks like an initrd\n", err);
593		fd = sys_open("/initrd.image", O_WRONLY|O_CREAT, 0700);
594		if (fd >= 0) {
595			sys_write(fd, (char *)initrd_start,
596					initrd_end - initrd_start);
597			sys_close(fd);
598			free_initrd();
599		}
600#else
601		printk(KERN_INFO "Unpacking initramfs...\n");
602		err = unpack_to_rootfs((char *)initrd_start,
603			initrd_end - initrd_start);
604		if (err)
605			printk(KERN_EMERG "Initramfs unpacking failed: %s\n", err);
606		free_initrd();
607#endif
608	}
609	return 0;
610}
611rootfs_initcall(populate_rootfs);
612