Fix some bugs reported by Jim Gleason <jimg@lineo.com> and others I
[oweals/busybox.git] / archival / tar.c
1 /* vi: set sw=4 ts=4: */
2 /*
3  * Mini tar implementation for busybox 
4  *
5  * Note, that as of BusyBox-0.43, tar has been completely rewritten from the
6  * ground up.  It still has remnents of the old code lying about, but it is
7  * very different now (i.e. cleaner, less global variables, etc)
8  *
9  * Copyright (C) 2000 by Lineo, inc.
10  * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
11  *
12  * Based in part in the tar implementation in sash
13  *  Copyright (c) 1999 by David I. Bell
14  *  Permission is granted to use, distribute, or modify this source,
15  *  provided that this copyright notice remains intact.
16  *  Permission to distribute sash derived code under the GPL has been granted.
17  *
18  * Based in part on the tar implementation from busybox-0.28
19  *  Copyright (C) 1995 Bruce Perens
20  *  This is free software under the GNU General Public License.
21  *
22  * This program is free software; you can redistribute it and/or modify
23  * it under the terms of the GNU General Public License as published by
24  * the Free Software Foundation; either version 2 of the License, or
25  * (at your option) any later version.
26  *
27  * This program is distributed in the hope that it will be useful,
28  * but WITHOUT ANY WARRANTY; without even the implied warranty of
29  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30  * General Public License for more details.
31  *
32  * You should have received a copy of the GNU General Public License
33  * along with this program; if not, write to the Free Software
34  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
35  *
36  */
37
38
39 #include "busybox.h"
40 #define BB_DECLARE_EXTERN
41 #define bb_need_io_error
42 #define bb_need_name_longer_then_foo
43 #include "messages.c"
44 #include <stdio.h>
45 #include <dirent.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <signal.h>
49 #include <time.h>
50 #include <utime.h>
51 #include <sys/types.h>
52 #include <sys/sysmacros.h>
53 #include <getopt.h>
54
55 /* Tar file constants  */
56 #ifndef MAJOR
57 #define MAJOR(dev) (((dev)>>8)&0xff)
58 #define MINOR(dev) ((dev)&0xff)
59 #endif
60
61 #define NAME_SIZE       100
62
63 /* POSIX tar Header Block, from POSIX 1003.1-1990  */
64 struct TarHeader
65 {
66                                 /* byte offset */
67         char name[NAME_SIZE];         /*   0-99 */
68         char mode[8];                 /* 100-107 */
69         char uid[8];                  /* 108-115 */
70         char gid[8];                  /* 116-123 */
71         char size[12];                /* 124-135 */
72         char mtime[12];               /* 136-147 */
73         char chksum[8];               /* 148-155 */
74         char typeflag;                /* 156-156 */
75         char linkname[NAME_SIZE];     /* 157-256 */
76         char magic[6];                /* 257-262 */
77         char version[2];              /* 263-264 */
78         char uname[32];               /* 265-296 */
79         char gname[32];               /* 297-328 */
80         char devmajor[8];             /* 329-336 */
81         char devminor[8];             /* 337-344 */
82         char prefix[155];             /* 345-499 */
83         char padding[12];             /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
84 };
85 typedef struct TarHeader TarHeader;
86
87
88 /* A few useful constants */
89 #define TAR_MAGIC          "ustar"        /* ustar and a null */
90 #define TAR_VERSION        "  "           /* Be compatable with GNU tar format */
91 #define TAR_MAGIC_LEN       6
92 #define TAR_VERSION_LEN     2
93 #define TAR_BLOCK_SIZE      512
94
95 /* A nice enum with all the possible tar file content types */
96 enum TarFileType 
97 {
98         REGTYPE  = '0',            /* regular file */
99         REGTYPE0 = '\0',           /* regular file (ancient bug compat)*/
100         LNKTYPE  = '1',            /* hard link */
101         SYMTYPE  = '2',            /* symbolic link */
102         CHRTYPE  = '3',            /* character special */
103         BLKTYPE  = '4',            /* block special */
104         DIRTYPE  = '5',            /* directory */
105         FIFOTYPE = '6',            /* FIFO special */
106         CONTTYPE = '7',            /* reserved */
107         GNULONGLINK = 'K',         /* GNU long (>100 chars) link name */
108         GNULONGNAME = 'L',         /* GNU long (>100 chars) file name */
109 };
110 typedef enum TarFileType TarFileType;
111
112 /* This struct ignores magic, non-numeric user name, 
113  * non-numeric group name, and the checksum, since
114  * these are all ignored by BusyBox tar. */ 
115 struct TarInfo
116 {
117         int              tarFd;          /* An open file descriptor for reading from the tarball */
118         char *           name;           /* File name */
119         mode_t           mode;           /* Unix mode, including device bits. */
120         uid_t            uid;            /* Numeric UID */
121         gid_t            gid;            /* Numeric GID */
122         size_t           size;           /* Size of file */
123         time_t           mtime;          /* Last-modified time */
124         enum TarFileType type;           /* Regular, directory, link, etc */
125         char *           linkname;       /* Name for symbolic and hard links */
126         long             devmajor;       /* Major number for special device */
127         long             devminor;       /* Minor number for special device */
128 };
129 typedef struct TarInfo TarInfo;
130
131 /* Local procedures to restore files from a tar file.  */
132 static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
133                 int tostdoutFlag, int verboseFlag, char** extractList,
134                 char** excludeList);
135
136
137
138 #ifdef BB_FEATURE_TAR_CREATE
139 /* Local procedures to save files into a tar file.  */
140 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
141                 char** excludeList);
142 #endif
143
144 extern int tar_main(int argc, char **argv)
145 {
146         char** excludeList=NULL;
147 #if defined BB_FEATURE_TAR_EXCLUDE
148         int excludeListSize=0;
149 #endif
150         const char *tarName="-";
151         int listFlag     = FALSE;
152         int extractFlag  = FALSE;
153         int createFlag   = FALSE;
154         int verboseFlag  = FALSE;
155         int tostdoutFlag = FALSE;
156         int firstOpt = TRUE;
157         int stopIt;
158                                                                                                                                                    
159
160         if (argc <= 1)
161                 usage(tar_usage);
162
163         while (*(++argv) && (**argv == '-' || firstOpt == TRUE)) {
164                 firstOpt=FALSE;
165                 stopIt=FALSE;
166                 while (stopIt==FALSE && **argv) {
167                         switch (*((*argv)++)) {
168                                 case 'c':
169                                         if (extractFlag == TRUE || listFlag == TRUE)
170                                                 goto flagError;
171                                         createFlag = TRUE;
172                                         break;
173                                 case 'x':
174                                         if (listFlag == TRUE || createFlag == TRUE)
175                                                 goto flagError;
176                                         extractFlag = TRUE;
177                                         break;
178                                 case 't':
179                                         if (extractFlag == TRUE || createFlag == TRUE)
180                                                 goto flagError;
181                                         listFlag = TRUE;
182                                         break;
183                                 case 'v':
184                                         verboseFlag = TRUE;
185                                         break;
186                                 case 'O':
187                                         tostdoutFlag = TRUE;
188                                         break;                                  
189                                 case 'f':
190                                         if (*tarName != '-')
191                                                 fatalError( "Only one 'f' option allowed\n");
192                                         tarName = *(++argv);
193                                         if (tarName == NULL)
194                                                 fatalError( "Option requires an argument: No file specified\n");
195                                         stopIt=TRUE;
196                                         break;
197 #if defined BB_FEATURE_TAR_EXCLUDE
198                                 case 'e':
199                                         if (strcmp(*argv, "exclude")==0) {
200                                                 excludeList=xrealloc( excludeList, sizeof(char**) * (excludeListSize+2));
201                                                 excludeList[excludeListSize] = *(++argv);
202                                                 if (excludeList[excludeListSize] == NULL)
203                                                         fatalError( "Option requires an argument: No file specified\n");
204                                                 /* Remove leading "/"s */
205                                                 if (*excludeList[excludeListSize] =='/')
206                                                         excludeList[excludeListSize] = (excludeList[excludeListSize])+1;
207                                                 /* Tack a NULL onto the end of the list */
208                                                 excludeList[++excludeListSize] = NULL;
209                                                 stopIt=TRUE;
210                                                 break;
211                                         }
212 #endif
213                                 case '-':
214                                                 break;
215                                 default:
216                                         usage(tar_usage);
217                         }
218                 }
219         }
220
221         /* 
222          * Do the correct type of action supplying the rest of the
223          * command line arguments as the list of files to process.
224          */
225         if (createFlag == TRUE) {
226 #ifndef BB_FEATURE_TAR_CREATE
227                 fatalError( "This version of tar was not compiled with tar creation support.\n");
228 #else
229                 exit(writeTarFile(tarName, verboseFlag, argv, excludeList));
230 #endif
231         }
232         if (listFlag == TRUE || extractFlag == TRUE) {
233                 exit(readTarFile(tarName, extractFlag, listFlag, tostdoutFlag,
234                                         verboseFlag, argv, excludeList));
235         }
236
237   flagError:
238         fatalError( "Exactly one of 'c', 'x' or 't' must be specified\n");
239 }
240                                         
241 static void
242 fixUpPermissions(TarInfo *header)
243 {
244         struct utimbuf t;
245         /* Now set permissions etc for the new file */
246         chown(header->name, header->uid, header->gid);
247         chmod(header->name, header->mode);
248         /* Reset the time */
249         t.actime = time(0);
250         t.modtime = header->mtime;
251         utime(header->name, &t);
252 }
253                                 
254 static int
255 tarExtractRegularFile(TarInfo *header, int extractFlag, int tostdoutFlag)
256 {
257         size_t  writeSize;
258         size_t  readSize;
259         size_t  actualWriteSz;
260         char    buffer[BUFSIZ];
261         size_t  size = header->size;
262         int outFd=fileno(stdout);
263
264         /* Open the file to be written, if a file is supposed to be written */
265         if (extractFlag==TRUE && tostdoutFlag==FALSE) {
266                 /* Create the path to the file, just in case it isn't there...
267                  * This should not screw up path permissions or anything. */
268                 createPath(header->name, 0777);
269                 if ((outFd=open(header->name, O_CREAT|O_TRUNC|O_WRONLY, 
270                                                 header->mode & ~S_IFMT)) < 0) {
271                         errorMsg(io_error, header->name, strerror(errno)); 
272                         return( FALSE);
273                 }
274         }
275
276         /* Write out the file, if we are supposed to be doing that */
277         while ( size > 0 ) {
278                 actualWriteSz=0;
279                 if ( size > sizeof(buffer) )
280                         writeSize = readSize = sizeof(buffer);
281                 else {
282                         int mod = size % 512;
283                         if ( mod != 0 )
284                                 readSize = size + (512 - mod);
285                         else
286                                 readSize = size;
287                         writeSize = size;
288                 }
289                 if ( (readSize = fullRead(header->tarFd, buffer, readSize)) <= 0 ) {
290                         /* Tarball seems to have a problem */
291                         errorMsg("Unexpected EOF in archive\n"); 
292                         return( FALSE);
293                 }
294                 if ( readSize < writeSize )
295                         writeSize = readSize;
296
297                 /* Write out the file, if we are supposed to be doing that */
298                 if (extractFlag==TRUE) {
299
300                         if ((actualWriteSz=fullWrite(outFd, buffer, writeSize)) != writeSize ) {
301                                 /* Output file seems to have a problem */
302                                 errorMsg(io_error, header->name, strerror(errno)); 
303                                 return( FALSE);
304                         }
305                 } else {
306                         actualWriteSz=writeSize;
307                 }
308
309                 size -= actualWriteSz;
310         }
311
312         /* Now we are done writing the file out, so try 
313          * and fix up the permissions and whatnot */
314         if (extractFlag==TRUE && tostdoutFlag==FALSE) {
315                 close(outFd);
316                 fixUpPermissions(header);
317         }
318         return( TRUE);
319 }
320
321 static int
322 tarExtractDirectory(TarInfo *header, int extractFlag, int tostdoutFlag)
323 {
324
325         if (extractFlag==FALSE || tostdoutFlag==TRUE)
326                 return( TRUE);
327
328         if (createPath(header->name, header->mode) != TRUE) {
329                 errorMsg("%s: Cannot mkdir: %s\n", 
330                                 header->name, strerror(errno)); 
331                 return( FALSE);
332         }
333         /* make the final component, just in case it was
334          * omitted by createPath() (which will skip the
335          * directory if it doesn't have a terminating '/') */
336         if (mkdir(header->name, header->mode) == 0) {
337                 fixUpPermissions(header);
338         }
339         return( TRUE);
340 }
341
342 static int
343 tarExtractHardLink(TarInfo *header, int extractFlag, int tostdoutFlag)
344 {
345         if (extractFlag==FALSE || tostdoutFlag==TRUE)
346                 return( TRUE);
347
348         if (link(header->linkname, header->name) < 0) {
349                 errorMsg("%s: Cannot create hard link to '%s': %s\n", 
350                                 header->name, header->linkname, strerror(errno)); 
351                 return( FALSE);
352         }
353
354         /* Now set permissions etc for the new directory */
355         fixUpPermissions(header);
356         return( TRUE);
357 }
358
359 static int
360 tarExtractSymLink(TarInfo *header, int extractFlag, int tostdoutFlag)
361 {
362         if (extractFlag==FALSE || tostdoutFlag==TRUE)
363                 return( TRUE);
364
365 #ifdef  S_ISLNK
366         if (symlink(header->linkname, header->name) < 0) {
367                 errorMsg("%s: Cannot create symlink to '%s': %s\n", 
368                                 header->name, header->linkname, strerror(errno)); 
369                 return( FALSE);
370         }
371         /* Try to change ownership of the symlink.
372          * If libs doesn't support that, don't bother.
373          * Changing the pointed-to-file is the Wrong Thing(tm).
374          */
375 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
376         lchown(header->name, header->uid, header->gid);
377 #endif
378
379         /* Do not change permissions or date on symlink,
380          * since it changes the pointed to file instead.  duh. */
381 #else
382         errorMsg("%s: Cannot create symlink to '%s': %s\n", 
383                         header->name, header->linkname, 
384                         "symlinks not supported"); 
385 #endif
386         return( TRUE);
387 }
388
389 static int
390 tarExtractSpecial(TarInfo *header, int extractFlag, int tostdoutFlag)
391 {
392         if (extractFlag==FALSE || tostdoutFlag==TRUE)
393                 return( TRUE);
394
395         if (S_ISCHR(header->mode) || S_ISBLK(header->mode) || S_ISSOCK(header->mode)) {
396                 if (mknod(header->name, header->mode, makedev(header->devmajor, header->devminor)) < 0) {
397                         errorMsg("%s: Cannot mknod: %s\n",
398                                 header->name, strerror(errno)); 
399                         return( FALSE);
400                 }
401         } else if (S_ISFIFO(header->mode)) {
402                 if (mkfifo(header->name, header->mode) < 0) {
403                         errorMsg("%s: Cannot mkfifo: %s\n",
404                                 header->name, strerror(errno)); 
405                         return( FALSE);
406                 }
407         }
408
409         /* Now set permissions etc for the new directory */
410         fixUpPermissions(header);
411         return( TRUE);
412 }
413
414 /* Read an octal value in a field of the specified width, with optional
415  * spaces on both sides of the number and with an optional null character
416  * at the end.  Returns -1 on an illegal format.  */
417 static long getOctal(const char *cp, int size)
418 {
419         long val = 0;
420
421         for(;(size > 0) && (*cp == ' '); cp++, size--);
422         if ((size == 0) || !isOctal(*cp))
423                 return -1;
424         for(; (size > 0) && isOctal(*cp); size--) {
425                 val = val * 8 + *cp++ - '0';
426         }
427         for (;(size > 0) && (*cp == ' '); cp++, size--);
428         if ((size > 0) && *cp)
429                 return -1;
430         return val;
431 }
432
433
434 /* Parse the tar header and fill in the nice struct with the details */
435 static int
436 readTarHeader(struct TarHeader *rawHeader, struct TarInfo *header)
437 {
438         int i;
439         long chksum, sum=0;
440         unsigned char *s = (unsigned char *)rawHeader;
441
442         header->name  = rawHeader->name;
443         /* Check for and relativify any absolute paths */
444         if ( *(header->name) == '/' ) {
445                 static int alreadyWarned=FALSE;
446
447                 while (*(header->name) == '/')
448                         ++*(header->name);
449
450                 if (alreadyWarned == FALSE) {
451                         errorMsg("Removing leading '/' from member names\n");
452                         alreadyWarned = TRUE;
453                 }
454         }
455
456         header->mode  = getOctal(rawHeader->mode, sizeof(rawHeader->mode));
457         header->uid   =  getOctal(rawHeader->uid, sizeof(rawHeader->uid));
458         header->gid   =  getOctal(rawHeader->gid, sizeof(rawHeader->gid));
459         header->size  = getOctal(rawHeader->size, sizeof(rawHeader->size));
460         header->mtime = getOctal(rawHeader->mtime, sizeof(rawHeader->mtime));
461         chksum = getOctal(rawHeader->chksum, sizeof(rawHeader->chksum));
462         header->type  = rawHeader->typeflag;
463         header->linkname  = rawHeader->linkname;
464         header->devmajor  = getOctal(rawHeader->devmajor, sizeof(rawHeader->devmajor));
465         header->devminor  = getOctal(rawHeader->devminor, sizeof(rawHeader->devminor));
466
467         /* Check the checksum */
468         for (i = sizeof(*rawHeader); i-- != 0;) {
469                 sum += *s++;
470         }
471         /* Remove the effects of the checksum field (replace 
472          * with blanks for the purposes of the checksum) */
473         s = rawHeader->chksum;
474         for (i = sizeof(rawHeader->chksum) ; i-- != 0;) {
475                 sum -= *s++;
476         }
477         sum += ' ' * sizeof(rawHeader->chksum);
478         if (sum == chksum )
479                 return ( TRUE);
480         return( FALSE);
481 }
482
483
484 /*
485  * Read a tar file and extract or list the specified files within it.
486  * If the list is empty than all files are extracted or listed.
487  */
488 static int readTarFile(const char* tarName, int extractFlag, int listFlag, 
489                 int tostdoutFlag, int verboseFlag, char** extractList,
490                 char** excludeList)
491 {
492         int status, tarFd=-1;
493         int errorFlag=FALSE;
494         int skipNextHeaderFlag=FALSE;
495         TarHeader rawHeader;
496         TarInfo header;
497         char** tmpList;
498
499         /* Open the tar file for reading.  */
500         if (!strcmp(tarName, "-"))
501                 tarFd = fileno(stdin);
502         else
503                 tarFd = open(tarName, O_RDONLY);
504         if (tarFd < 0) {
505                 errorMsg( "Error opening '%s': %s\n", tarName, strerror(errno));
506                 return ( FALSE);
507         }
508
509         /* Set the umask for this process so it doesn't 
510          * screw up permission setting for us later. */
511         umask(0);
512
513         /* Read the tar file, and iterate over it one file at a time */
514         while ( (status = fullRead(tarFd, (char*)&rawHeader, TAR_BLOCK_SIZE)) == TAR_BLOCK_SIZE ) {
515
516                 /* Try to read the header */
517                 if ( readTarHeader(&rawHeader, &header) == FALSE ) {
518                         if ( *(header.name) == '\0' ) {
519                                 goto endgame;
520                         } else {
521                                 errorFlag=TRUE;
522                                 errorMsg("Bad tar header, skipping\n");
523                                 continue;
524                         }
525                 }
526                 if ( *(header.name) == '\0' )
527                                 goto endgame;
528                 header.tarFd = tarFd;
529
530                 /* Skip funky extra GNU headers that precede long files */
531                 if ( (header.type == GNULONGNAME) || (header.type == GNULONGLINK) ) {
532                         skipNextHeaderFlag=TRUE;
533                         tarExtractRegularFile(&header, FALSE, FALSE);
534                         continue;
535                 }
536                 if ( skipNextHeaderFlag == TRUE ) { 
537                         skipNextHeaderFlag=FALSE;
538                         errorMsg(name_longer_then_foo, NAME_SIZE); 
539                         tarExtractRegularFile(&header, FALSE, FALSE);
540                         continue;
541                 }
542
543 #if defined BB_FEATURE_TAR_EXCLUDE
544                 {
545                         int skipFlag=FALSE;
546                         /* Check for excluded files....  */
547                         for (tmpList=excludeList; tmpList && *tmpList; tmpList++) {
548                                 /* Do some extra hoop jumping for when directory names
549                                  * end in '/' but the entry in tmpList doesn't */
550                                 if (strncmp( *tmpList, header.name, strlen(*tmpList))==0 || (
551                                                         header.name[strlen(header.name)-1]=='/'
552                                                         && strncmp( *tmpList, header.name, 
553                                                                 MIN(strlen(header.name)-1, strlen(*tmpList)))==0)) {
554                                         /* If it is a regular file, pretend to extract it with
555                                          * the extractFlag set to FALSE, so the junk in the tarball
556                                          * is properly skipped over */
557                                         if ( header.type==REGTYPE || header.type==REGTYPE0 ) {
558                                                         tarExtractRegularFile(&header, FALSE, FALSE);
559                                         }
560                                         skipFlag=TRUE;
561                                         break;
562                                 }
563                         }
564                         /* There are not the droids you're looking for, move along */
565                         if (skipFlag==TRUE)
566                                 continue;
567                 }
568 #endif
569                 if (*extractList != NULL) {
570                         int skipFlag = TRUE;
571                         for (tmpList = extractList; *tmpList != NULL; tmpList++) {
572                                 if (strncmp( *tmpList, header.name, strlen(*tmpList))==0 || (
573                                                         header.name[strlen(header.name)-1]=='/'
574                                                         && strncmp( *tmpList, header.name, 
575                                                                 MIN(strlen(header.name)-1, strlen(*tmpList)))==0)) {
576                                         /* If it is a regular file, pretend to extract it with
577                                          * the extractFlag set to FALSE, so the junk in the tarball
578                                          * is properly skipped over */
579                                         skipFlag = FALSE;
580                                         break;
581                                 }
582                         }
583                         /* There are not the droids you're looking for, move along */
584                         if (skipFlag == TRUE) {
585                                 if ( header.type==REGTYPE || header.type==REGTYPE0 )
586                                                 tarExtractRegularFile(&header, FALSE, FALSE);
587                                 continue;
588                         }
589                 }
590
591                 if (listFlag == TRUE) {
592                         /* Special treatment if the list (-t) flag is on */
593                         if (verboseFlag == TRUE) {
594                                 int len, len1;
595                                 char buf[35];
596                                 struct tm *tm = localtime (&(header.mtime));
597
598                                 len=printf("%s ", modeString(header.mode));
599                                 memset(buf, 0, 8*sizeof(char));
600                                 my_getpwuid(buf, header.uid);
601                                 if (! *buf)
602                                         len+=printf("%d", header.uid);
603                                 else
604                                         len+=printf("%s", buf);
605                                 memset(buf, 0, 8*sizeof(char));
606                                 my_getgrgid(buf, header.gid);
607                                 if (! *buf)
608                                         len+=printf("/%-d ", header.gid);
609                                 else
610                                         len+=printf("/%-s ", buf);
611
612                                 if (header.type==CHRTYPE || header.type==BLKTYPE) {
613                                         len1=snprintf(buf, sizeof(buf), "%ld,%-ld ", 
614                                                         header.devmajor, header.devminor);
615                                 } else {
616                                         len1=snprintf(buf, sizeof(buf), "%lu ", (long)header.size);
617                                 }
618                                 /* Jump through some hoops to make the columns match up */
619                                 for(;(len+len1)<31;len++)
620                                         printf(" ");
621                                 printf(buf);
622
623                                 /* Use ISO 8610 time format */
624                                 if (tm) { 
625                                         printf ("%04d-%02d-%02d %02d:%02d:%02d ", 
626                                                         tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday, 
627                                                         tm->tm_hour, tm->tm_min, tm->tm_sec);
628                                 }
629                         }
630                         printf("%s", header.name);
631                         if (verboseFlag == TRUE) {
632                                 if (header.type==LNKTYPE)       /* If this is a link, say so */
633                                         printf(" link to %s", header.linkname);
634                                 else if (header.type==SYMTYPE)
635                                         printf(" -> %s", header.linkname);
636                         }
637                         printf("\n");
638                 }
639
640                 /* List contents if we are supposed to do that */
641                 if (verboseFlag == TRUE && extractFlag == TRUE) {
642                         /* Now the normal listing */
643                         FILE *vbFd = stdout;
644                         if (tostdoutFlag == TRUE)       // If the archive goes to stdout, verbose to stderr
645                                 vbFd = stderr;
646                         fprintf(vbFd, "%s\n", header.name);
647                 }
648                         
649                 /* Remove files if we would overwrite them */
650                 if (extractFlag == TRUE && tostdoutFlag == FALSE)
651                         unlink(header.name);
652
653                 /* If we got here, we can be certain we have a legitimate 
654                  * header to work with.  So work with it.  */
655                 switch ( header.type ) {
656                         case REGTYPE:
657                         case REGTYPE0:
658                                 /* If the name ends in a '/' then assume it is
659                                  * supposed to be a directory, and fall through */
660                                 if (header.name[strlen(header.name)-1] != '/') {
661                                         if (tarExtractRegularFile(&header, extractFlag, tostdoutFlag)==FALSE)
662                                                 errorFlag=TRUE;
663                                         break;
664                                 }
665                         case DIRTYPE:
666                                 if (tarExtractDirectory( &header, extractFlag, tostdoutFlag)==FALSE)
667                                         errorFlag=TRUE;
668                                 break;
669                         case LNKTYPE:
670                                 if (tarExtractHardLink( &header, extractFlag, tostdoutFlag)==FALSE)
671                                         errorFlag=TRUE;
672                                 break;
673                         case SYMTYPE:
674                                 if (tarExtractSymLink( &header, extractFlag, tostdoutFlag)==FALSE)
675                                         errorFlag=TRUE;
676                                 break;
677                         case CHRTYPE:
678                         case BLKTYPE:
679                         case FIFOTYPE:
680                                 if (tarExtractSpecial( &header, extractFlag, tostdoutFlag)==FALSE)
681                                         errorFlag=TRUE;
682                                 break;
683 #if 0
684                         /* Handled earlier */
685                         case GNULONGNAME:
686                         case GNULONGLINK:
687                                 skipNextHeaderFlag=TRUE;
688                                 break;
689 #endif
690                         default:
691                                 errorMsg("Unknown file type '%c' in tar file\n", header.type);
692                                 close( tarFd);
693                                 return( FALSE);
694                 }
695         }
696         close(tarFd);
697         if (status > 0) {
698                 /* Bummer - we read a partial header */
699                 errorMsg( "Error reading '%s': %s\n", tarName, strerror(errno));
700                 return ( FALSE);
701         }
702         else if (errorFlag==TRUE) {
703                 errorMsg( "Error exit delayed from previous errors\n");
704                 return( FALSE);
705         } else 
706                 return( status);
707
708         /* Stuff to do when we are done */
709 endgame:
710         close( tarFd);
711         if ( *(header.name) == '\0' ) {
712                 if (errorFlag==TRUE)
713                         errorMsg( "Error exit delayed from previous errors\n");
714                 else
715                         return( TRUE);
716         } 
717         return( FALSE);
718 }
719
720
721 #ifdef BB_FEATURE_TAR_CREATE
722
723 /* Some info to be carried along when creating a new tarball */
724 struct TarBallInfo
725 {
726         char* fileName;               /* File name of the tarball */
727         int tarFd;                    /* Open-for-write file descriptor
728                                                                          for the tarball */
729         struct stat statBuf;          /* Stat info for the tarball, letting
730                                                                          us know the inode and device that the
731                                                                          tarball lives, so we can avoid trying 
732                                                                          to include the tarball into itself */
733         int verboseFlag;              /* Whether to print extra stuff or not */
734         char** excludeList;           /* List of files to not include */
735 };
736 typedef struct TarBallInfo TarBallInfo;
737
738
739 /* Put an octal string into the specified buffer.
740  * The number is zero and space padded and possibly null padded.
741  * Returns TRUE if successful.  */ 
742 static int putOctal (char *cp, int len, long value)
743 {
744         int tempLength;
745         char tempBuffer[32];
746         char *tempString = tempBuffer;
747
748         /* Create a string of the specified length with an initial space,
749          * leading zeroes and the octal number, and a trailing null.  */
750         sprintf (tempString, "%0*lo", len - 1, value);
751
752         /* If the string is too large, suppress the leading space.  */
753         tempLength = strlen (tempString) + 1;
754         if (tempLength > len) {
755                 tempLength--;
756                 tempString++;
757         }
758
759         /* If the string is still too large, suppress the trailing null.  */
760         if (tempLength > len)
761                 tempLength--;
762
763         /* If the string is still too large, fail.  */
764         if (tempLength > len)
765                 return FALSE;
766
767         /* Copy the string to the field.  */
768         memcpy (cp, tempString, len);
769
770         return TRUE;
771 }
772
773 /* Write out a tar header for the specified file/directory/whatever */
774 static int
775 writeTarHeader(struct TarBallInfo *tbInfo, const char *fileName, struct stat *statbuf)
776 {
777         long chksum=0;
778         struct TarHeader header;
779 #if defined BB_FEATURE_TAR_EXCLUDE
780         char** tmpList;
781 #endif
782         const unsigned char *cp = (const unsigned char *) &header;
783         ssize_t size = sizeof(struct TarHeader);
784                 
785         memset( &header, 0, size);
786
787         if (*fileName=='/') {
788                 static int alreadyWarned=FALSE;
789                 if (alreadyWarned==FALSE) {
790                         errorMsg("Removing leading '/' from member names\n");
791                         alreadyWarned=TRUE;
792                 }
793                 strncpy(header.name, fileName+1, sizeof(header.name)); 
794         }
795         else {
796                 strncpy(header.name, fileName, sizeof(header.name)); 
797         }
798
799 #if defined BB_FEATURE_TAR_EXCLUDE
800         /* Check for excluded files....  */
801         for (tmpList=tbInfo->excludeList; tmpList && *tmpList; tmpList++) {
802                 /* Do some extra hoop jumping for when directory names
803                  * end in '/' but the entry in tmpList doesn't */
804                 if (strncmp( *tmpList, header.name, strlen(*tmpList))==0 || (
805                                         header.name[strlen(header.name)-1]=='/'
806                                         && strncmp( *tmpList, header.name, 
807                                                 MIN(strlen(header.name)-1, strlen(*tmpList)))==0)) {
808                         /* Set the mode to something that is not a regular file, thereby
809                          * faking out writeTarFile into thinking that nothing further need
810                          * be done for this file.  Yes, I know this is ugly, but it works. */
811                         statbuf->st_mode = 0;
812                         return( TRUE);
813                 }
814         }
815 #endif
816
817         putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
818         putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
819         putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
820         putOctal(header.size, sizeof(header.size), 0); /* Regular file size is handled later */
821         putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
822         strncpy(header.magic, TAR_MAGIC TAR_VERSION, 
823                         TAR_MAGIC_LEN + TAR_VERSION_LEN );
824
825         /* Enter the user and group names (default to root if it fails) */
826         my_getpwuid(header.uname, statbuf->st_uid);
827         if (! *header.uname)
828                 strcpy(header.uname, "root");
829         my_getgrgid(header.gname, statbuf->st_gid);
830         if (! *header.uname)
831                 strcpy(header.uname, "root");
832
833         /* WARNING/NOTICE: I break Hard Links */
834         if (S_ISLNK(statbuf->st_mode)) {
835                 int link_size=0;
836                 char buffer[BUFSIZ];
837                 header.typeflag  = SYMTYPE;
838                 link_size = readlink(fileName, buffer, sizeof(buffer) - 1);
839                 if ( link_size < 0) {
840                         errorMsg("Error reading symlink '%s': %s\n", header.name, strerror(errno));
841                         return ( FALSE);
842                 }
843                 buffer[link_size] = '\0';
844                 strncpy(header.linkname, buffer, sizeof(header.linkname)); 
845         } else if (S_ISDIR(statbuf->st_mode)) {
846                 header.typeflag  = DIRTYPE;
847                 strncat(header.name, "/", sizeof(header.name)); 
848         } else if (S_ISCHR(statbuf->st_mode)) {
849                 header.typeflag  = CHRTYPE;
850                 putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
851                 putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
852         } else if (S_ISBLK(statbuf->st_mode)) {
853                 header.typeflag  = BLKTYPE;
854                 putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
855                 putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
856         } else if (S_ISFIFO(statbuf->st_mode)) {
857                 header.typeflag  = FIFOTYPE;
858         } else if (S_ISREG(statbuf->st_mode)) {
859                 header.typeflag  = REGTYPE;
860                 putOctal(header.size, sizeof(header.size), statbuf->st_size);
861         } else {
862                 errorMsg("%s: Unknown file type\n", fileName);
863                 return ( FALSE);
864         }
865
866         /* Calculate and store the checksum (i.e. the sum of all of the bytes of
867          * the header).  The checksum field must be filled with blanks for the
868          * calculation.  The checksum field is formatted differently from the
869          * other fields: it has [6] digits, a null, then a space -- rather than
870          * digits, followed by a null like the other fields... */
871         memset(header.chksum, ' ', sizeof(header.chksum));
872         cp = (const unsigned char *) &header;
873         while (size-- > 0)
874                 chksum += *cp++;
875         putOctal(header.chksum, 7, chksum);
876         
877         /* Now write the header out to disk */
878         if ((size=fullWrite(tbInfo->tarFd, (char*)&header, sizeof(struct TarHeader))) < 0) {
879                 errorMsg(io_error, fileName, strerror(errno)); 
880                 return ( FALSE);
881         }
882         /* Pad the header up to the tar block size */
883         for (; size<TAR_BLOCK_SIZE; size++) {
884                 write(tbInfo->tarFd, "\0", 1);
885         }
886         /* Now do the verbose thing (or not) */
887         if (tbInfo->verboseFlag==TRUE) {
888                 FILE *vbFd = stdout;
889                 if (tbInfo->tarFd == fileno(stdout))    // If the archive goes to stdout, verbose to stderr
890                         vbFd = stderr;
891                 fprintf(vbFd, "%s\n", header.name);
892         }
893
894         return ( TRUE);
895 }
896
897
898 static int writeFileToTarball(const char *fileName, struct stat *statbuf, void* userData)
899 {
900         struct TarBallInfo *tbInfo = (struct TarBallInfo *)userData;
901
902         /* It is against the rules to archive a socket */
903         if (S_ISSOCK(statbuf->st_mode)) {
904                 errorMsg("%s: socket ignored\n", fileName);
905                 return( TRUE);
906         }
907
908         /* It is a bad idea to store the archive we are in the process of creating,
909          * so check the device and inode to be sure that this particular file isn't
910          * the new tarball */
911         if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
912                         tbInfo->statBuf.st_ino == statbuf->st_ino) {
913                 errorMsg("%s: file is the archive; skipping\n", fileName);
914                 return( TRUE);
915         }
916
917         if (strlen(fileName) >= NAME_SIZE) {
918                 errorMsg(name_longer_then_foo, NAME_SIZE);
919                 return ( TRUE);
920         }
921
922         if (writeTarHeader(tbInfo, fileName, statbuf)==FALSE) {
923                 return( FALSE);
924         } 
925
926         /* Now, if the file is a regular file, copy it out to the tarball */
927         if (S_ISREG(statbuf->st_mode)) {
928                 int  inputFileFd;
929                 char buffer[BUFSIZ];
930                 ssize_t size=0, readSize=0;
931
932                 /* open the file we want to archive, and make sure all is well */
933                 if ((inputFileFd = open(fileName, O_RDONLY)) < 0) {
934                         errorMsg("%s: Cannot open: %s\n", fileName, strerror(errno));
935                         return( FALSE);
936                 }
937                 
938                 /* write the file to the archive */
939                 while ( (size = fullRead(inputFileFd, buffer, sizeof(buffer))) > 0 ) {
940                         if (fullWrite(tbInfo->tarFd, buffer, size) != size ) {
941                                 /* Output file seems to have a problem */
942                                 errorMsg(io_error, fileName, strerror(errno)); 
943                                 return( FALSE);
944                         }
945                         readSize+=size;
946                 }
947                 if (size == -1) {
948                         errorMsg(io_error, fileName, strerror(errno)); 
949                         return( FALSE);
950                 }
951                 /* Pad the file up to the tar block size */
952                 for (; (readSize%TAR_BLOCK_SIZE) != 0; readSize++) {
953                         write(tbInfo->tarFd, "\0", 1);
954                 }
955                 close( inputFileFd);
956         }
957
958         return( TRUE);
959 }
960
961 static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
962                 char** excludeList)
963 {
964         int tarFd=-1;
965         int errorFlag=FALSE;
966         ssize_t size;
967         struct TarBallInfo tbInfo;
968         tbInfo.verboseFlag = verboseFlag;
969
970         /* Make sure there is at least one file to tar up.  */
971         if (*argv == NULL)
972                 fatalError("Cowardly refusing to create an empty archive\n");
973
974         /* Open the tar file for writing.  */
975         if (!strcmp(tarName, "-"))
976                 tbInfo.tarFd = fileno(stdout);
977         else
978                 tbInfo.tarFd = open (tarName, O_WRONLY | O_CREAT | O_TRUNC, 0644);
979         if (tbInfo.tarFd < 0) {
980                 errorMsg( "Error opening '%s': %s\n", tarName, strerror(errno));
981                 return ( FALSE);
982         }
983         tbInfo.excludeList=excludeList;
984         /* Store the stat info for the tarball's file, so
985          * can avoid including the tarball into itself....  */
986         if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
987                 fatalError(io_error, tarName, strerror(errno)); 
988
989         /* Set the umask for this process so it doesn't 
990          * screw up permission setting for us later. */
991         umask(0);
992
993         /* Read the directory/files and iterate over them one at a time */
994         while (*argv != NULL) {
995                 if (recursiveAction(*argv++, TRUE, FALSE, FALSE,
996                                         writeFileToTarball, writeFileToTarball, 
997                                         (void*) &tbInfo) == FALSE) {
998                         errorFlag = TRUE;
999                 }
1000         }
1001         /* Write two empty blocks to the end of the archive */
1002         for (size=0; size<(2*TAR_BLOCK_SIZE); size++) {
1003                 write(tbInfo.tarFd, "\0", 1);
1004         }
1005
1006         /* To be pedantically correct, we would check if the tarball
1007          * is smaller then 20 tar blocks, and pad it if it was smaller,
1008          * but that isn't necessary for GNU tar interoperability, and
1009          * so is considered a waste of space */
1010
1011         /* Hang up the tools, close up shop, head home */
1012         close(tarFd);
1013         if (errorFlag == TRUE) {
1014                 errorMsg("Error exit delayed from previous errors\n");
1015                 return(FALSE);
1016         }
1017         return( TRUE);
1018 }
1019
1020
1021 #endif
1022