--- /dev/null
+/* 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 2, 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.
+ */
+
+#include <stdio.h>
+#include <errno.h>
+#ifndef STDC_HEADERS
+extern int errno;
+#endif
+#include <sys/types.h>
+#include <time.h>
+time_t time();
+
+#ifdef BSD42
+#include <sys/file.h>
+#else
+#ifndef V7
+#include <fcntl.h>
+#endif
+#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
+
+#include "tar.h"
+#include "port.h"
+
+#if defined(_POSIX_VERSION)
+#include <utime.h>
+#endif
+
+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;
+
+int confirm();
+void decode_header();
+void extract_mangle();
+void extract_sparse_file();
+long from_oct();
+void gnu_restore();
+extern void print_header();
+extern void skip_file();
+extern void skip_extended_headers();
+extern void pr_mkdir();
+void saverec();
+
+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.
+ */
+void
+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_ISLNK
+ 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;
+#endif
+#if defined(S_IFCHR) || defined(S_IFBLK)
+ 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;
+#endif
+
+#ifdef S_ISFIFO
+ /* If local system doesn't support FIFOs, use default case */
+ case LF_FIFO:
+ make_fifo:
+ check = mkfifo(skipcrud+head->header.name,
+ (int) hstat.st_mode);
+ if (check != 0) {
+ if (make_dirs(skipcrud+head->header.name))
+ goto make_fifo;
+ msg_perror("Could not make %s",skipcrud+head->header.name);
+ break;
+ };
+ goto set_filestat;
+#endif
+
+ 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
+ && (S_ISDIR(st1.st_mode)))
+ 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 */
+}
+
+void
+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);
+}
projects / chaz / tar / commitdiff
