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386BSD 0.1 development
[unix-history] / usr / src / usr.bin / tar / extract.c
/* Extract files from a tar archive.
Copyright (C) 1988 Free Software Foundation
This file is part of GNU Tar.
GNU Tar 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 1, or (at your option)
any later version.
GNU Tar 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 GNU Tar; see the file COPYING. If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
/*
* Extract files from a tar archive.
*
* Written 19 Nov 1985 by John Gilmore, ihnp4!hoptoad!gnu.
*
* @(#) extract.c 1.32 87/11/11 - gnu
*/
#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef BSD42
#include <sys/file.h>
#endif
#ifdef USG
#include <fcntl.h>
#endif
#ifdef MSDOS
#include <fcntl.h>
#endif /* MSDOS */
/*
* Some people don't have a #define for these.
*/
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_NDELAY
#define O_NDELAY 0
#endif
#ifdef NO_OPEN3
/* We need the #define's even though we don't use them. */
#include "open3.h"
#endif
#ifdef EMUL_OPEN3
/* Simulated 3-argument open for systems that don't have it */
#include "open3.h"
#endif
extern int errno; /* From libc.a */
extern time_t time(); /* From libc.a */
extern char *index(); /* From libc.a or port.c */
#include "tar.h"
#include "port.h"
extern FILE *msg_file;
extern union record *head; /* Points to current tape header */
extern struct stat hstat; /* Stat struct corresponding */
extern int head_standard; /* Tape header is in ANSI format */
extern char *save_name;
extern long save_totsize;
extern long save_sizeleft;
extern void print_header();
extern void skip_file();
extern void skip_extended_headers();
extern void pr_mkdir();
int make_dirs(); /* Makes required directories */
static time_t now = 0; /* Current time */
static we_are_root = 0; /* True if our effective uid == 0 */
static int notumask = ~0; /* Masks out bits user doesn't want */
/*
* "Scratch" space to store the information about a sparse file before
* writing the info into the header or extended header
*/
/*struct sp_array *sparsearray;*/
/* number of elts storable in the sparsearray */
/*int sp_array_size = 10;*/
/*
* Set up to extract files.
*/
extr_init()
{
int ourmask;
now = time((time_t *)0);
if (geteuid() == 0)
we_are_root = 1;
/*
* We need to know our umask. But if f_use_protection is set,
* leave our kernel umask at 0, and our "notumask" at ~0.
*/
ourmask = umask(0); /* Read it */
if (!f_use_protection) {
(void) umask (ourmask); /* Set it back how it was */
notumask = ~ourmask; /* Make umask override permissions */
}
}
/*
* Extract a file from the archive.
*/
void
extract_archive()
{
register char *data;
int fd, check, namelen, written, openflag;
long size;
time_t acc_upd_times[2];
register int skipcrud;
register int i;
int sparse_ind = 0;
union record *exhdr;
int end_nulls;
saverec(&head); /* Make sure it sticks around */
userec(head); /* And go past it in the archive */
decode_header(head, &hstat, &head_standard, 1); /* Snarf fields */
if(f_confirm && !confirm("extract",head->header.name)) {
if (head->header.isextended)
skip_extended_headers();
skip_file((long)hstat.st_size);
saverec((union record **)0);
return;
}
/* Print the record from 'head' and 'hstat' */
if (f_verbose)
print_header();
/*
* Check for fully specified pathnames and other atrocities.
*
* Note, we can't just make a pointer to the new file name,
* since saverec() might move the header and adjust "head".
* We have to start from "head" every time we want to touch
* the header record.
*/
skipcrud = 0;
while (!f_absolute_paths && '/' == head->header.name[skipcrud]) {
static int warned_once = 0;
skipcrud++; /* Force relative path */
if (!warned_once++) {
msg("Removing leading / from absolute path names in the archive.");
}
}
switch (head->header.linkflag) {
default:
msg("Unknown file type '%c' for %s, extracted as normal file",
head->header.linkflag, skipcrud+head->header.name);
/* FALL THRU */
/*
* JK - What we want to do if the file is sparse is loop through
* the array of sparse structures in the header and read in
* and translate the character strings representing 1) the offset
* at which to write and 2) how many bytes to write into numbers,
* which we store into the scratch array, "sparsearray". This
* array makes our life easier the same way it did in creating
* the tar file that had to deal with a sparse file.
*
* After we read in the first five (at most) sparse structures,
* we check to see if the file has an extended header, i.e.,
* if more sparse structures are needed to describe the contents
* of the new file. If so, we read in the extended headers
* and continue to store their contents into the sparsearray.
*/
case LF_SPARSE:
sp_array_size = 10;
sparsearray = (struct sp_array *) malloc(sp_array_size * sizeof(struct sp_array));
for (i = 0; i < SPARSE_IN_HDR; i++) {
sparsearray[i].offset =
from_oct(1+12, head->header.sp[i].offset);
sparsearray[i].numbytes =
from_oct(1+12, head->header.sp[i].numbytes);
if (!sparsearray[i].numbytes)
break;
}
/* end_nulls = from_oct(1+12, head->header.ending_blanks);*/
if (head->header.isextended) {
/* read in the list of extended headers
and translate them into the sparsearray
as before */
/* static */ int ind = SPARSE_IN_HDR;
for (;;) {
exhdr = findrec();
for (i = 0; i < SPARSE_EXT_HDR; i++) {
if (i+ind > sp_array_size-1) {
/*
* realloc the scratch area
* since we've run out of room --
*/
sparsearray = (struct sp_array *)
realloc(sparsearray,
2 * sp_array_size * (sizeof(struct sp_array)));
sp_array_size *= 2;
}
if (!exhdr->ext_hdr.sp[i].numbytes)
break;
sparsearray[i+ind].offset =
from_oct(1+12, exhdr->ext_hdr.sp[i].offset);
sparsearray[i+ind].numbytes =
from_oct(1+12, exhdr->ext_hdr.sp[i].numbytes);
}
if (!exhdr->ext_hdr.isextended)
break;
else {
ind += SPARSE_EXT_HDR;
userec(exhdr);
}
}
userec(exhdr);
}
/* FALL THRU */
case LF_OLDNORMAL:
case LF_NORMAL:
case LF_CONTIG:
/*
* Appears to be a file.
* See if it's really a directory.
*/
namelen = strlen(skipcrud+head->header.name)-1;
if (head->header.name[skipcrud+namelen] == '/')
goto really_dir;
/* FIXME, deal with protection issues */
again_file:
openflag = (f_keep?
O_BINARY|O_NDELAY|O_WRONLY|O_CREAT|O_EXCL:
O_BINARY|O_NDELAY|O_WRONLY|O_CREAT|O_TRUNC)
| ((head->header.linkflag == LF_SPARSE) ? 0 : O_APPEND);
/*
* JK - The last | is a kludge to solve the problem
* the O_APPEND flag causes with files we are
* trying to make sparse: when a file is opened
* with O_APPEND, it writes to the last place
* that something was written, thereby ignoring
* any lseeks that we have done. We add this
* extra condition to make it able to lseek when
* a file is sparse, i.e., we don't open the new
* file with this flag. (Grump -- this bug caused
* me to waste a good deal of time, I might add)
*/
if(f_exstdout) {
fd = 1;
goto extract_file;
}
#ifdef O_CTG
/*
* Contiguous files (on the Masscomp) have to specify
* the size in the open call that creates them.
*/
if (head->header.linkflag == LF_CONTIG)
fd = open(skipcrud+head->header.name, openflag | O_CTG,
hstat.st_mode, hstat.st_size);
else
#endif
{
#ifdef NO_OPEN3
/*
* On raw V7 we won't let them specify -k (f_keep), but
* we just bull ahead and create the files.
*/
fd = creat(skipcrud+head->header.name,
hstat.st_mode);
#else
/*
* With 3-arg open(), we can do this up right.
*/
fd = open(skipcrud+head->header.name, openflag,
hstat.st_mode);
#endif
}
if (fd < 0) {
if (make_dirs(skipcrud+head->header.name))
goto again_file;
msg_perror("Could not create file %s",skipcrud+head->header.name);
if (head->header.isextended)
skip_extended_headers();
skip_file((long)hstat.st_size);
goto quit;
}
extract_file:
if (head->header.linkflag == LF_SPARSE) {
char *name;
int namelen;
/*
* Kludge alert. NAME is assigned to header.name
* because during the extraction, the space that
* contains the header will get scribbled on, and
* the name will get munged, so any error messages
* that happen to contain the filename will look
* REAL interesting unless we do this.
*/
namelen = strlen(skipcrud+head->header.name);
name = (char *) malloc((sizeof(char)) * namelen);
bcopy(skipcrud+head->header.name, name, namelen);
size = hstat.st_size;
extract_sparse_file(fd, &size, hstat.st_size,
name);
}
else
for (size = hstat.st_size;
size > 0;
size -= written) {
long offset,
numbytes;
if(f_multivol) {
save_name=head->header.name;
save_totsize=hstat.st_size;
save_sizeleft=size;
}
/*
* Locate data, determine max length
* writeable, write it, record that
* we have used the data, then check
* if the write worked.
*/
data = findrec()->charptr;
if (data == NULL) { /* Check it... */
msg("Unexpected EOF on archive file");
break;
}
/*
* JK - If the file is sparse, use the sparsearray
* that we created before to lseek into the new
* file the proper amount, and to see how many
* bytes we want to write at that position.
*/
/* if (head->header.linkflag == LF_SPARSE) {
off_t pos;
pos = lseek(fd, (off_t) sparsearray[sparse_ind].offset, 0);
printf("%d at %d\n", (int) pos, sparse_ind);
written = sparsearray[sparse_ind++].numbytes;
} else*/
written = endofrecs()->charptr - data;
if (written > size)
written = size;
errno = 0;
check = write(fd, data, written);
/*
* The following is in violation of strict
* typing, since the arg to userec
* should be a struct rec *. FIXME.
*/
userec((union record *)(data + written - 1));
if (check == written) continue;
/*
* Error in writing to file.
* Print it, skip to next file in archive.
*/
if(check<0)
msg_perror("couldn't write to file %s",skipcrud+head->header.name);
else
msg("could only write %d of %d bytes to file %s",written,check,skipcrud+head->header.name);
skip_file((long)(size - written));
break; /* Still do the close, mod time, chmod, etc */
}
if(f_multivol)
save_name = 0;
/* If writing to stdout, don't try to do anything
to the filename; it doesn't exist, or we don't
want to touch it anyway */
if(f_exstdout)
break;
/* if (head->header.isextended) {
register union record *exhdr;
register int i;
for (i = 0; i < 21; i++) {
long offset;
if (!exhdr->ext_hdr.sp[i].numbytes)
break;
offset = from_oct(1+12,
exhdr->ext_hdr.sp[i].offset);
written = from_oct(1+12,
exhdr->ext_hdr.sp[i].numbytes);
lseek(fd, offset, 0);
check = write(fd, data, written);
if (check == written) continue;
}
}*/
check = close(fd);
if (check < 0) {
msg_perror("Error while closing %s",skipcrud+head->header.name);
}
set_filestat:
/*
* If we are root, set the owner and group of the extracted
* file. This does what is wanted both on real Unix and on
* System V. If we are running as a user, we extract as that
* user; if running as root, we extract as the original owner.
*/
if (we_are_root || f_do_chown) {
if (chown(skipcrud+head->header.name, hstat.st_uid,
hstat.st_gid) < 0) {
msg_perror("cannot chown file %s to uid %d gid %d",skipcrud+head->header.name,hstat.st_uid,hstat.st_gid);
}
}
/*
* Set the modified time of the file.
*
* Note that we set the accessed time to "now", which
* is really "the time we started extracting files".
* unless f_gnudump is used, in which case .st_atime is used
*/
if (!f_modified) {
/* fixme if f_gnudump should set ctime too, but how? */
if(f_gnudump)
acc_upd_times[0]=hstat.st_atime;
else acc_upd_times[0] = now; /* Accessed now */
acc_upd_times[1] = hstat.st_mtime; /* Mod'd */
if (utime(skipcrud+head->header.name,
acc_upd_times) < 0) {
msg_perror("couldn't change access and modification times of %s",skipcrud+head->header.name);
}
}
/* We do the utime before the chmod because some versions of
utime are broken and trash the modes of the file. Since
we then change the mode anyway, we don't care. . . */
/*
* If '-k' is not set, open() or creat() could have saved
* the permission bits from a previously created file,
* ignoring the ones we specified.
* Even if -k is set, if the file has abnormal
* mode bits, we must chmod since writing or chown() has
* probably reset them.
*
* If -k is set, we know *we* created this file, so the mode
* bits were set by our open(). If the file is "normal", we
* skip the chmod. This works because we did umask(0) if -p
* is set, so umask will have left the specified mode alone.
*/
if ((!f_keep)
|| (hstat.st_mode & (S_ISUID|S_ISGID|S_ISVTX))) {
if (chmod(skipcrud+head->header.name,
notumask & (int)hstat.st_mode) < 0) {
msg_perror("cannot change mode of file %s to %ld",skipcrud+head->header.name,notumask & (int)hstat.st_mode);
}
}
quit:
break;
case LF_LINK:
again_link:
{
struct stat st1,st2;
check = link (head->header.linkname,
skipcrud+head->header.name);
if (check == 0)
break;
if (make_dirs(skipcrud+head->header.name))
goto again_link;
if(f_gnudump && errno==EEXIST)
break;
if( stat(head->header.linkname, &st1) == 0
&& stat(skipcrud+head->header.name, &st2)==0
&& st1.st_dev==st2.st_dev
&& st1.st_ino==st2.st_ino)
break;
msg_perror("Could not link %s to %s",
skipcrud+head->header.name,head->header.linkname);
}
break;
#ifdef S_IFLNK
case LF_SYMLINK:
again_symlink:
check = symlink(head->header.linkname,
skipcrud+head->header.name);
/* FIXME, don't worry uid, gid, etc... */
if (check == 0)
break;
if (make_dirs(skipcrud+head->header.name))
goto again_symlink;
msg_perror("Could not create symlink to %s",head->header.linkname);
break;
#endif
#ifdef S_IFCHR
case LF_CHR:
hstat.st_mode |= S_IFCHR;
goto make_node;
#endif
#ifdef S_IFBLK
case LF_BLK:
hstat.st_mode |= S_IFBLK;
goto make_node;
#endif
#ifdef S_IFIFO
/* If local system doesn't support FIFOs, use default case */
case LF_FIFO:
hstat.st_mode |= S_IFIFO;
hstat.st_rdev = 0; /* FIXME, do we need this? */
goto make_node;
#endif
make_node:
check = mknod(skipcrud+head->header.name,
(int) hstat.st_mode, (int) hstat.st_rdev);
if (check != 0) {
if (make_dirs(skipcrud+head->header.name))
goto make_node;
msg_perror("Could not make %s",skipcrud+head->header.name);
break;
};
goto set_filestat;
case LF_DIR:
case LF_DUMPDIR:
namelen = strlen(skipcrud+head->header.name)-1;
really_dir:
/* Check for trailing /, and zap as many as we find. */
while (namelen && head->header.name[skipcrud+namelen] == '/')
head->header.name[skipcrud+namelen--] = '\0';
if(f_gnudump) { /* Read the entry and delete files
that aren't listed in the archive */
gnu_restore(skipcrud);
} else if(head->header.linkflag==LF_DUMPDIR)
skip_file((long)(hstat.st_size));
again_dir:
check = mkdir(skipcrud+head->header.name,
(we_are_root ? 0 : 0300) | (int)hstat.st_mode);
if (check != 0) {
struct stat st1;
if (make_dirs(skipcrud+head->header.name))
goto again_dir;
/* If we're trying to create '.', let it be. */
if (head->header.name[skipcrud+namelen] == '.' &&
(namelen==0 ||
head->header.name[skipcrud+namelen-1]=='/'))
goto check_perms;
if( errno==EEXIST
&& stat(skipcrud+head->header.name,&st1)==0
&& (st1.st_mode&S_IFMT)==S_IFDIR)
break;
msg_perror("Could not create directory %s",skipcrud+head->header.name);
break;
}
check_perms:
if (!we_are_root && 0300 != (0300 & (int) hstat.st_mode)) {
hstat.st_mode |= 0300;
msg("Added write and execute permission to directory %s",
skipcrud+head->header.name);
}
goto set_filestat;
/* FIXME, Remember timestamps for after files created? */
/* FIXME, change mode after files created (if was R/O dir) */
case LF_VOLHDR:
if(f_verbose) {
printf("Reading %s\n",head->header.name);
}
break;
case LF_NAMES:
extract_mangle(head);
break;
case LF_MULTIVOL:
msg("Can't extract '%s'--file is continued from another volume\n",head->header.name);
skip_file((long)hstat.st_size);
break;
}
/* We don't need to save it any longer. */
saverec((union record **) 0); /* Unsave it */
}
/*
* After a file/link/symlink/dir creation has failed, see if
* it's because some required directory was not present, and if
* so, create all required dirs.
*/
int
make_dirs(pathname)
char *pathname;
{
char *p; /* Points into path */
int madeone = 0; /* Did we do anything yet? */
int save_errno = errno; /* Remember caller's errno */
int check;
if (errno != ENOENT)
return 0; /* Not our problem */
for (p = index(pathname, '/'); p != NULL; p = index(p+1, '/')) {
/* Avoid mkdir of empty string, if leading or double '/' */
if (p == pathname || p[-1] == '/')
continue;
/* Avoid mkdir where last part of path is '.' */
if (p[-1] == '.' && (p == pathname+1 || p[-2] == '/'))
continue;
*p = 0; /* Truncate the path there */
check = mkdir (pathname, 0777); /* Try to create it as a dir */
if (check == 0) {
/* Fix ownership */
if (we_are_root) {
if (chown(pathname, hstat.st_uid,
hstat.st_gid) < 0) {
msg_perror("cannot change owner of %s to uid %d gid %d",pathname,hstat.st_uid,hstat.st_gid);
}
}
pr_mkdir(pathname, p-pathname, notumask&0777);
madeone++; /* Remember if we made one */
*p = '/';
continue;
}
*p = '/';
if (errno == EEXIST) /* Directory already exists */
continue;
/*
* Some other error in the mkdir. We return to the caller.
*/
break;
}
errno = save_errno; /* Restore caller's errno */
return madeone; /* Tell them to retry if we made one */
}
extract_sparse_file(fd, sizeleft, totalsize, name)
int fd;
long *sizeleft,
totalsize;
char *name;
{
register char *data;
union record *datarec;
int sparse_ind = 0;
int written,
count;
/* assuming sizeleft is initially totalsize */
while (*sizeleft > 0) {
datarec = findrec();
if (datarec == NULL) {
msg("Unexpected EOF on archive file");
return;
}
lseek(fd, sparsearray[sparse_ind].offset, 0);
written = sparsearray[sparse_ind++].numbytes;
while (written > RECORDSIZE) {
count = write(fd, datarec->charptr, RECORDSIZE);
if (count < 0)
msg_perror("couldn't write to file %s", name);
written -= count;
*sizeleft -= count;
userec(datarec);
datarec = findrec();
}
count = write(fd, datarec->charptr, written);
if (count < 0) {
msg_perror("couldn't write to file %s", name);
} else if (count != written) {
msg("could only write %d of %d bytes to file %s", totalsize - *sizeleft, totalsize, name);
skip_file((long) (*sizeleft));
}
written -= count;
*sizeleft -= count;
userec(datarec);
}
free(sparsearray);
/* if (end_nulls) {
register int i;
printf("%d\n", (int) end_nulls);
for (i = 0; i < end_nulls; i++)
write(fd, "\000", 1);
}*/
userec(datarec);
}
Continuous source code history from original PDP-7 UNIX to FreeBSD 2, the first fully unencumbered FreeBSD release.