aboutsummaryrefslogtreecommitdiff
path: root/ar.c
blob: 0f16ec88cf097f888c92f28e4802e0f2ee86ed18 (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
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
/* vi: set sw=4 ts=4: */
/*
 * Mini ar implementation for busybox 
 *
 * Copyright (C) 2000 by Glenn McGrath
 * Written by Glenn McGrath <bug1@netconnect.com.au> 1 June 2000
 * 		
 * Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * Last modified 20 September 2000
 */
#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <time.h>
#include <utime.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <malloc.h>
#include "busybox.h"

#define BLOCK_SIZE 60
#define PRESERVE_DATE 1	/* preserve original dates */
#define VERBOSE       2	/* be verbose */
#define DISPLAY       4	/* display contents */
#define EXT_TO_FILE   8	/* extract contents of archive */
#define EXT_TO_STDOUT 16	/* extract to stdout */
#define RECURSIVE     32  	 

#define MAX_NAME_LENGTH 100

//#define BB_DECLARE_EXTERN
//#define bb_need_io_error
//#include "messages.c"

//#define BB_AR_EXPERIMENTAL_UNTAR

#if defined BB_AR_EXPERIMENTAL_UNTAR
typedef struct rawTarHeader {
        char name[100];               /*   0-99 */
        char mode[8];                 /* 100-107 */
        char uid[8];                  /* 108-115 */
        char gid[8];                  /* 116-123 */
        char size[12];                /* 124-135 */
        char mtime[12];               /* 136-147 */
        char chksum[8];               /* 148-155 */
        char typeflag;                /* 156-156 */
        char linkname[100];           /* 157-256 */
        char magic[6];                /* 257-262 */
        char version[2];              /* 263-264 */
        char uname[32];               /* 265-296 */
        char gname[32];               /* 297-328 */
        char devmajor[8];             /* 329-336 */
        char devminor[8];             /* 337-344 */
        char prefix[155];             /* 345-499 */
        char padding[12];             /* 500-512 */
} rawTarHeader_t;
#endif

typedef struct rawArHeader {    /* Byte Offset */
        char name[16];          /*  0-15 */
        char date[12];          /* 16-27 */
        char uid[6], gid[6];    /* 28-39 */
        char mode[8];           /* 40-47 */
        char size[10];          /* 48-57 */
        char fmag[2];           /* 58-59 */
} rawArHeader_t;

typedef struct headerL {
	char name[MAX_NAME_LENGTH];
        size_t size;
        uid_t uid;
        gid_t gid;
        mode_t mode;
        time_t mtime;
        off_t offset;
	struct headerL *next;
} headerL_t;

#if defined BB_AR_EXPERIMENTAL_UNTAR
/*
 * identify Tar header (magic field) and reset srcFd to entry position
 */
static int checkTarMagic(int srcFd)
{
        off_t headerStart;
        char magic[6];

        headerStart = lseek(srcFd, 0, SEEK_CUR);
        lseek(srcFd, (off_t) 257, SEEK_CUR);
        fullRead(srcFd, magic, 6);
        lseek(srcFd, headerStart, SEEK_SET);
        if (strncmp(magic, "ustar", 5)!=0)
                return(FALSE);
        return(TRUE);
}


static int readTarHeader(int srcFd, headerL_t *current)
{
     	rawTarHeader_t rawTarHeader;
        unsigned char *temp = (unsigned char *) &rawTarHeader;
        long sum = 0;
        int i;
	off_t initialOffset;

        initialOffset = lseek(srcFd, 0, SEEK_CUR);
        if (fullRead(srcFd, (char *) &rawTarHeader, 512) != 512) {
                lseek(srcFd, initialOffset, SEEK_SET);
                return(FALSE);
        }
        for (i =  0; i < 148 ; i++)
        sum += temp[i];
        sum += ' ' * 8;
        for (i =  156; i < 512 ; i++)
                sum += temp[i];
        if (sum!= strtol(rawTarHeader.chksum, NULL, 8))
		return(FALSE);
  	sscanf(rawTarHeader.name, "%s", current->name);
        current->size = strtol(rawTarHeader.size, NULL, 8);
        current->uid = strtol(rawTarHeader.uid, NULL, 8);
        current->gid = strtol(rawTarHeader.gid, NULL, 8);
        current->mode = strtol(rawTarHeader.mode, NULL, 8);
        current->mtime = strtol(rawTarHeader.mtime, NULL, 8);
        current->offset = lseek(srcFd, 0 , SEEK_CUR);

        current->next = (headerL_t *) xmalloc(sizeof(headerL_t));
        current = current->next;
     	return(TRUE);
}
#endif

/*
 * identify Ar header (magic) and reset srcFd to entry position
 */
static int checkArMagic(int srcFd)
{
        off_t headerStart;
        char arMagic[8];

        headerStart = lseek(srcFd, 0, SEEK_CUR);
        if (fullRead(srcFd, arMagic, 8) != 8) {
                errorMsg("fatal error\n");
                return (FALSE);
        }
        lseek(srcFd, headerStart, SEEK_SET);

        if (strncmp(arMagic,"!<arch>",7) != 0)
                return(FALSE);
        return(TRUE);
}

/*
 * get, check and correct the converted header
 */ 
static int readArEntry(int srcFd, headerL_t *entry)
{
	size_t nameLength;
        rawArHeader_t rawArHeader;
        off_t   initialOffset;

        initialOffset = lseek(srcFd, 0, SEEK_CUR);
        if (fullRead(srcFd, (char *) &rawArHeader, 60) != 60) {
                lseek(srcFd, initialOffset, SEEK_SET);
                return(FALSE);
        }
        if ((rawArHeader.fmag[0]!='`') || (rawArHeader.fmag[1]!='\n')) {
                lseek(srcFd, initialOffset, SEEK_SET);
                return(FALSE);
        }

        strncpy(entry->name, rawArHeader.name, 16);
        nameLength=strcspn(entry->name, " \\");
        entry->name[nameLength]='\0';
        parse_mode(rawArHeader.mode, &entry->mode);
        entry->mtime = atoi(rawArHeader.date);
        entry->uid = atoi(rawArHeader.uid);
        entry->gid = atoi(rawArHeader.gid);
        entry->size = (size_t) atoi(rawArHeader.size);
        entry->offset = initialOffset + (off_t) 60;

	nameLength = strcspn(entry->name, "/");
	
	/* handle GNU style short filenames, strip trailing '/' */
	if (nameLength > 0)
		entry->name[nameLength]='\0';
	
	/* handle GNU style long filenames */ 
	if (nameLength == 0) {
		/* escape from recursive call */
		if (entry->name[1]=='0') 
			return(TRUE);

		/* the data section contains the real filename */
		if (entry->name[1]=='/') {
			char tempName[MAX_NAME_LENGTH];

			if (entry->size > MAX_NAME_LENGTH)
				entry->size = MAX_NAME_LENGTH;
			fullRead(srcFd, tempName, entry->size);
			tempName[entry->size-3]='\0';
			
			/* read the second header for this entry */
			/* be carefull, this is recursive */
			if (readArEntry(srcFd, entry)==FALSE)
				return(FALSE);
		
			if ((entry->name[0]='/') && (entry->name[1]='0'))
				strcpy(entry->name, tempName);
			else {
				errorMsg("Invalid long filename\n");
				return(FALSE);
			}
		}
	}
	return(TRUE);	
}

/*
 * return the headerL_t struct for the specified filename
 */
static headerL_t *getHeaders(int srcFd, headerL_t *head, int funct)
{
#if defined BB_AR_EXPERIMENTAL_UNTAR
        int tar=FALSE;
#endif
	int ar=FALSE;
	headerL_t *list;
	off_t initialOffset;

	list = (headerL_t *) xmalloc(sizeof(headerL_t));
	initialOffset=lseek(srcFd, 0, SEEK_CUR);
	if (checkArMagic(srcFd)==TRUE) 
		ar=TRUE;

#if defined BB_AR_EXPERIMENTAL_UNTAR
	if (checkTarMagic(srcFd)==TRUE)
		tar=TRUE;

        if (tar==TRUE) {
                while(readTarHeader(srcFd, list)==TRUE) {
			off_t tarOffset;
                        list->next = (headerL_t *) xmalloc(sizeof(headerL_t));
                        *list->next = *head;
                        *head = *list;

                        /* recursive check for sub-archives */
                        if ((funct & RECURSIVE) == RECURSIVE)
                                head = getHeaders(srcFd, head, funct);
                        tarOffset = (off_t) head->size/512;
                        if ( head->size % 512 > 0)
                                tarOffset++;
                        tarOffset=tarOffset*512;
                        lseek(srcFd, head->offset + tarOffset, SEEK_SET);
                }
        }
#endif

        if (ar==TRUE) {
		lseek(srcFd, 8, SEEK_CUR); 
        	while(1) {
			if (readArEntry(srcFd, list) == FALSE) {
				lseek(srcFd, ++initialOffset, SEEK_CUR); 
				if (readArEntry(srcFd, list) == FALSE)
					return(head);
			}
			list->next = (headerL_t *) xmalloc(sizeof(headerL_t));
        		*list->next = *head;
			*head = *list;
			/* recursive check for sub-archives */
			if (funct & RECURSIVE)  
		        	head = getHeaders(srcFd, head, funct);
			lseek(srcFd, head->offset + head->size, SEEK_SET);
		}
	}
        return(head);
}

/*
 * find an entry in the linked list matching the filename
 */
static headerL_t *findEntry(headerL_t *head, const char *filename)
{
	while(head->next != NULL) {
		if (strcmp(filename, head->name)==0) 
			return(head);
		head=head->next;
	}
	return(NULL);
}

extern int ar_main(int argc, char **argv)
{
        int funct = 0, opt=0;
	int srcFd=0, dstFd=0;
 	headerL_t *header, *entry, *extractList;

	while ((opt = getopt(argc, argv, "ovtpxR")) != -1) {
		switch (opt) {
		case 'o':
			funct |= PRESERVE_DATE;
			break;
		case 'v':
			funct |= VERBOSE;
			break;
		case 't':
			funct |= DISPLAY;
			break;
		case 'x':
			funct |= EXT_TO_FILE;
			break;
		case 'p':
			funct |= EXT_TO_STDOUT;
			break;
		case 'R':
			funct |= RECURSIVE;
			break;
		default:
			usage(ar_usage);
		}
	}
 
	/* check the src filename was specified */
	if (optind == argc)
		usage(ar_usage);
	
	if ( (srcFd = open(argv[optind], O_RDONLY)) < 0)
		fatalError("Cannot read %s\n", argv[optind]);

 	optind++;	
	entry = (headerL_t *) xmalloc(sizeof(headerL_t));
	header = (headerL_t *) xmalloc(sizeof(headerL_t));
	extractList = (headerL_t *) xmalloc(sizeof(headerL_t));	

	header = getHeaders(srcFd, header, funct);
	/* find files to extract or display */
	if (optind<argc) {
		/* only handle specified files */
		while(optind < argc) { 
			if ( (entry = findEntry(header, argv[optind])) != NULL) {
	                        entry->next = (headerL_t *) xmalloc(sizeof(headerL_t));
                        	*entry->next = *extractList;
                        	*extractList = *entry;
			}
			optind++;
		}	
	}
	else  
		extractList = header;
	
        while(extractList->next != NULL) {	
		if (funct & EXT_TO_FILE) {
 			if (isDirectory(extractList->name, TRUE, NULL)==FALSE)
				createPath(extractList->name, 0666);
			dstFd = open(extractList->name, O_WRONLY | O_CREAT, extractList->mode);
			lseek(srcFd, extractList->offset, SEEK_SET);
        		copySubFile(srcFd, dstFd, (size_t) extractList->size);
		}
		if (funct & EXT_TO_STDOUT) {	
                   	lseek(srcFd, extractList->offset, SEEK_SET);
                        copySubFile(srcFd, fileno(stdout), (size_t) extractList->size);
		}
		if ( (funct & DISPLAY) || (funct & VERBOSE)) {
			if (funct & VERBOSE)
				printf("%s %d/%d %8d %s ", modeString(extractList->mode), 
					extractList->uid, extractList->gid,
					extractList->size, timeString(extractList->mtime));
		        printf("%s\n", extractList->name);
		}
		extractList=extractList->next;
	}
	return EXIT_SUCCESS;
}