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- /* 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 */
- #ifndef AMIGA
- extern time_t time(); /* From libc.a */
- #endif
- 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 (f_do_chown || 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++) {
- if (!head->header.sp[i].numbytes)
- break;
- sparsearray[i].offset =
- from_oct(1+12, head->header.sp[i].offset);
- sparsearray[i].numbytes =
- from_oct(1+12, head->header.sp[i].numbytes);
- }
-
- /* 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) {
- 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);
- }
- }
-
- /*
- * 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);
- }
- }
- /*
- * 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);
- }
- }
-
- quit:
- break;
-
- case LF_LINK:
- again_link:
- 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;
- 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,
- 0300 | (int)hstat.st_mode);
- if (check != 0) {
- 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(f_gnudump && errno==EEXIST)
- break;
- msg_perror("Could not make directory %s",skipcrud+head->header.name);
- break;
- }
-
- check_perms:
- if (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_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);
- }
-