aboutsummaryrefslogtreecommitdiff
path: root/archival/libunarchive/get_header_cpio.c
blob: dd48cb09bb0a6fa13aaaf6795a3c98849b7bb2a7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
/* vi: set sw=4 ts=4: */
/* Copyright 2002 Laurence Anderson
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

#include "libbb.h"
#include "unarchive.h"

typedef struct hardlinks_s {
	file_header_t *entry;
	int inode;
	struct hardlinks_s *next;
} hardlinks_t;

char get_header_cpio(archive_handle_t *archive_handle)
{
	static hardlinks_t *saved_hardlinks = NULL;
	static unsigned short pending_hardlinks = 0;
	file_header_t *file_header = archive_handle->file_header;
	char cpio_header[110];
	int namesize;
	char dummy[16];
	int major, minor, nlink, inode;

	if (pending_hardlinks) { /* Deal with any pending hardlinks */
		hardlinks_t *tmp;
		hardlinks_t *oldtmp;

		tmp = saved_hardlinks;
		oldtmp = NULL;

		while (tmp) {
			bb_error_msg_and_die("need to fix this");
			if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
				file_header = tmp->entry;
				if (oldtmp) {
					oldtmp->next = tmp->next; /* Remove item from linked list */
				} else {
					saved_hardlinks = tmp->next;
				}
				free(tmp);
				continue;
			}
			oldtmp = tmp;
			tmp = tmp->next;
		}
		pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
	}

	/* There can be padding before archive header */
	data_align(archive_handle, 4);

	if (archive_xread_all_eof(archive_handle, (unsigned char*)cpio_header, 110) == 0) {
		return(EXIT_FAILURE);
	}
	archive_handle->offset += 110;

	if ((strncmp(&cpio_header[0], "07070", 5) != 0) || ((cpio_header[5] != '1') && (cpio_header[5] != '2'))) {
		bb_error_msg_and_die("unsupported cpio format, use newc or crc");
	}

	{
		unsigned long tmpsize;
		sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
		    dummy, &inode, (unsigned int*)&file_header->mode,
		    (unsigned int*)&file_header->uid, (unsigned int*)&file_header->gid,
		    &nlink, &file_header->mtime, &tmpsize,
		    dummy, &major, &minor, &namesize, dummy);
		file_header->size = tmpsize;
	}

	file_header->name = (char *) xzalloc(namesize + 1);
	/* Read in filename */
	xread(archive_handle->src_fd, file_header->name, namesize);
	archive_handle->offset += namesize;

	/* Update offset amount and skip padding before file contents */
	data_align(archive_handle, 4);

	if (strcmp(file_header->name, "TRAILER!!!") == 0) {
		printf("%d blocks\n", (int) (archive_handle->offset % 512 ? (archive_handle->offset / 512) + 1 : archive_handle->offset / 512)); /* Always round up */
		if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
			hardlinks_t *tmp = saved_hardlinks;
			hardlinks_t *oldtmp = NULL;
			while (tmp) {
				bb_error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
				oldtmp = tmp;
				tmp = tmp->next;
				free (oldtmp->entry->name);
				free (oldtmp->entry);
				free (oldtmp);
			}
			saved_hardlinks = NULL;
			pending_hardlinks = 0;
		}
		return(EXIT_FAILURE);
	}

	if (S_ISLNK(file_header->mode)) {
		file_header->link_name = (char *) xzalloc(file_header->size + 1);
		xread(archive_handle->src_fd, file_header->link_name, file_header->size);
		archive_handle->offset += file_header->size;
		file_header->size = 0; /* Stop possible seeks in future */
	} else {
		file_header->link_name = NULL;
	}
	if (nlink > 1 && !S_ISDIR(file_header->mode)) {
		if (file_header->size == 0) { /* Put file on a linked list for later */
			hardlinks_t *new = xmalloc(sizeof(hardlinks_t));
			new->next = saved_hardlinks;
			new->inode = inode;
			new->entry = file_header;
			saved_hardlinks = new;
			return(EXIT_SUCCESS); // Skip this one
		} else { /* Found the file with data in */
			hardlinks_t *tmp = saved_hardlinks;
			pending_hardlinks = 1;
			while (tmp) {
				if (tmp->inode == inode) {
					tmp->entry->link_name = xstrdup(file_header->name);
					nlink--;
				}
				tmp = tmp->next;
			}
			if (nlink > 1) {
				bb_error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
			}
		}
	}
	file_header->device = makedev(major, minor);

	if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) {
		archive_handle->action_data(archive_handle);
		archive_handle->action_header(archive_handle->file_header);
	} else {
		data_skip(archive_handle);
	}

	archive_handle->offset += file_header->size;

	free(file_header->link_name);

	return (EXIT_SUCCESS);
}