/* $Source: /u/mark/src/pax/RCS/extract.c,v $
*
* $Revision: 1.3 $
*
* extract.c - Extract files from a tar archive.
*
* DESCRIPTION
*
* AUTHOR
*
* Mark H. Colburn, NAPS International ([email protected])
*
* Sponsored by The USENIX Association for public distribution.
*
* Copyright (c) 1989 Mark H. Colburn.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice is duplicated in all such
* forms and that any documentation, advertising materials, and other
* materials related to such distribution and use acknowledge that the
* software was developed * by Mark H. Colburn and sponsored by The
* USENIX Association.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
* $Log: extract.c,v $
* Revision 1.3 89/02/12 10:29:43 mark
* Fixed misspelling of Replstr
*
* Revision 1.2 89/02/12 10:04:24 mark
* 1.2 release fixes
*
* Revision 1.1 88/12/23 18:02:07 mark
* Initial revision
*
*/
#ifndef lint
static char *ident = "$Id: extract.c,v 1.3 89/02/12 10:29:43 mark Exp Locker: mark $";
static char *copyright = "Copyright (c) 1989 Mark H. Colburn.\nAll rights reserved.\n";
#endif /* ! lint */
/* Headers */
#include "pax.h"
/* Defines */
/*
* Swap bytes.
*/
#define SWAB(n) ((((ushort)(n) >> 8) & 0xff) | (((ushort)(n) << 8) & 0xff00))
/* Function Prototypes */
#ifdef __STDC__
static int inbinary(char *, char *, Stat *);
static int inascii(char *, char *, Stat *);
static int inswab(char *, char *, Stat *);
static int readtar(char *, Stat *);
static int readcpio(char *, Stat *);
#else /* !__STDC__ */
static int inbinary();
static int inascii();
static int inswab();
static int readtar();
static int readcpio();
#endif /* __STDC__ */
/* read_archive - read in an archive
*
* DESCRIPTION
*
* Read_archive is the central entry point for reading archives.
* Read_archive determines the proper archive functions to call
* based upon the archive type being processed.
*
* RETURNS
*
*/
#ifdef __STDC__
int read_archive(void)
#else
int read_archive()
#endif
{
Stat sb;
char name[PATH_MAX + 1];
int match;
int pad;
name_gather(); /* get names from command line */
name[0] = '\0';
while (get_header(name, &sb) == 0) {
match = name_match(name) ^ f_reverse_match;
if (f_list) { /* only wanted a table of contents */
if (match) {
print_entry(name, &sb);
}
if (((ar_format == TAR)
? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE))
: buf_skip((OFFSET) sb.sb_size)) < 0) {
warn(name, "File data is corrupt");
}
} else if (match) {
if (rplhead != (Replstr *)NULL) {
rpl_name(name);
if (strlen(name) == 0) {
continue;
}
}
if (get_disposition("extract", name) ||
get_newname(name, sizeof(name))) {
/* skip file... */
if (((ar_format == TAR)
? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE))
: buf_skip((OFFSET) sb.sb_size)) < 0) {
warn(name, "File data is corrupt");
}
continue;
}
if (inentry(name, &sb) < 0) {
warn(name, "File data is corrupt");
}
if (f_verbose) {
print_entry(name, &sb);
}
if (ar_format == TAR && sb.sb_nlink > 1) {
/*
* This kludge makes sure that the link table is cleared
* before attempting to process any other links.
*/
if (sb.sb_nlink > 1) {
linkfrom(name, &sb);
}
}
if (ar_format == TAR && (pad = sb.sb_size % BLOCKSIZE) != 0) {
pad = BLOCKSIZE - pad;
buf_skip((OFFSET) pad);
}
} else {
if (((ar_format == TAR)
? buf_skip(ROUNDUP((OFFSET) sb.sb_size, BLOCKSIZE))
: buf_skip((OFFSET) sb.sb_size)) < 0) {
warn(name, "File data is corrupt");
}
}
}
close_archive();
}
/* get_header - figures which type of header needs to be read.
*
* DESCRIPTION
*
* This is merely a single entry point for the two types of archive
* headers which are supported. The correct header is selected
* depending on the archive type.
*
* PARAMETERS
*
* char *name - name of the file (passed to header routine)
* Stat *asb - Stat block for the file (passed to header routine)
*
* RETURNS
*
* Returns the value which was returned by the proper header
* function.
*/
#ifdef __STDC__
int get_header(char *name, Stat *asb)
#else
int get_header(name, asb)
char *name;
Stat *asb;
#endif
{
if (ar_format == TAR) {
return(readtar(name, asb));
} else {
return(readcpio(name, asb));
}
}
/* readtar - read a tar header
*
* DESCRIPTION
*
* Tar_head read a tar format header from the archive. The name
* and asb parameters are modified as appropriate for the file listed
* in the header. Name is assumed to be a pointer to an array of
* at least PATH_MAX bytes.
*
* PARAMETERS
*
* char *name - name of the file for which the header is
* for. This is modified and passed back to
* the caller.
* Stat *asb - Stat block for the file for which the header
* is for. The fields of the stat structure are
* extracted from the archive header. This is
* also passed back to the caller.
*
* RETURNS
*
* Returns 0 if a valid header was found, or -1 if EOF is
* encountered.
*/
#ifdef __STDC__
static int readtar(char *name, Stat *asb)
#else
static int readtar(name, asb)
char *name;
Stat *asb;
#endif
{
int status = 3; /* Initial status at start of archive */
static int prev_status;
for (;;) {
prev_status = status;
status = read_header(name, asb);
switch (status) {
case 1: /* Valid header */
return(0);
case 0: /* Invalid header */
switch (prev_status) {
case 3: /* Error on first record */
warn(ar_file, "This doesn't look like a tar archive");
/* FALLTHRU */
case 2: /* Error after record of zeroes */
case 1: /* Error after header rec */
warn(ar_file, "Skipping to next file...");
/* FALLTHRU */
default:
case 0: /* Error after error */
break;
}
break;
case 2: /* Record of zeroes */
case EOF: /* End of archive */
default:
return(-1);
}
}
}
/* readcpio - read a CPIO header
*
* DESCRIPTION
*
* Read in a cpio header. Understands how to determine and read ASCII,
* binary and byte-swapped binary headers. Quietly translates
* old-fashioned binary cpio headers (and arranges to skip the possible
* alignment byte). Returns zero if successful, -1 upon archive trailer.
*
* PARAMETERS
*
* char *name - name of the file for which the header is
* for. This is modified and passed back to
* the caller.
* Stat *asb - Stat block for the file for which the header
* is for. The fields of the stat structure are
* extracted from the archive header. This is
* also passed back to the caller.
*
* RETURNS
*
* Returns 0 if a valid header was found, or -1 if EOF is
* encountered.
*/
#ifdef __STDC__
static int readcpio(char *name, Stat *asb)
#else
static int readcpio(name, asb)
char *name;
Stat *asb;
#endif
{
OFFSET skipped;
char magic[M_STRLEN];
static int align;
if (align > 0) {
buf_skip((OFFSET) align);
}
align = 0;
for (;;) {
buf_read(magic, M_STRLEN);
skipped = 0;
while ((align = inascii(magic, name, asb)) < 0
&& (align = inbinary(magic, name, asb)) < 0
&& (align = inswab(magic, name, asb)) < 0) {
if (++skipped == 1) {
if (total - sizeof(magic) == 0) {
fatal("Unrecognizable archive");
}
warnarch("Bad magic number", (OFFSET) sizeof(magic));
if (name[0]) {
warn(name, "May be corrupt");
}
}
memcpy(magic, magic + 1, sizeof(magic) - 1);
buf_read(magic + sizeof(magic) - 1, 1);
}
if (skipped) {
warnarch("Apparently resynchronized", (OFFSET) sizeof(magic));
warn(name, "Continuing");
}
if (strcmp(name, TRAILER) == 0) {
return (-1);
}
if (nameopt(name) >= 0) {
break;
}
buf_skip((OFFSET) asb->sb_size + align);
}
#ifdef S_IFLNK
if ((asb->sb_mode & S_IFMT) == S_IFLNK) {
if (buf_read(asb->sb_link, (uint) asb->sb_size) < 0) {
warn(name, "Corrupt symbolic link");
return (readcpio(name, asb));
}
asb->sb_link[asb->sb_size] = '\0';
asb->sb_size = 0;
}
#endif /* S_IFLNK */
/* destroy absolute pathnames for security reasons */
if (name[0] == '/') {
if (name[1]) {
while (name[0] = name[1]) {
++name;
}
} else {
name[0] = '.';
}
}
asb->sb_atime = asb->sb_ctime = asb->sb_mtime;
if (asb->sb_nlink > 1) {
linkto(name, asb);
}
return (0);
}
/* inswab - read a reversed by order binary header
*
* DESCRIPTIONS
*
* Reads a byte-swapped CPIO binary archive header
*
* PARMAMETERS
*
* char *magic - magic number to match
* char *name - name of the file which is stored in the header.
* (modified and passed back to caller).
* Stat *asb - stat block for the file (modified and passed back
* to the caller).
*
*
* RETURNS
*
* Returns the number of trailing alignment bytes to skip; -1 if
* unsuccessful.
*
*/
#ifdef __STDC__
static int inswab(char *magic, char *name, Stat *asb)
#else
static int inswab(magic, name, asb)
char *magic;
char *name;
Stat *asb;
#endif
{
ushort namesize;
uint namefull;
Binary binary;
if (*((ushort *) magic) != SWAB(M_BINARY)) {
return (-1);
}
memcpy((char *) &binary,
magic + sizeof(ushort),
M_STRLEN - sizeof(ushort));
if (buf_read((char *) &binary + M_STRLEN - sizeof(ushort),
sizeof(binary) - (M_STRLEN - sizeof(ushort))) < 0) {
warnarch("Corrupt swapped header",
(OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort)));
return (-1);
}
asb->sb_dev = (dev_t) SWAB(binary.b_dev);
asb->sb_ino = (ino_t) SWAB(binary.b_ino);
asb->sb_mode = SWAB(binary.b_mode);
asb->sb_uid = SWAB(binary.b_uid);
asb->sb_gid = SWAB(binary.b_gid);
asb->sb_nlink = SWAB(binary.b_nlink);
#ifndef _POSIX_SOURCE
asb->sb_rdev = (dev_t) SWAB(binary.b_rdev);
#endif
asb->sb_mtime = SWAB(binary.b_mtime[0]) << 16 | SWAB(binary.b_mtime[1]);
asb->sb_size = SWAB(binary.b_size[0]) << 16 | SWAB(binary.b_size[1]);
if ((namesize = SWAB(binary.b_name)) == 0 || namesize >= PATH_MAX) {
warnarch("Bad swapped pathname length",
(OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort)));
return (-1);
}
if (buf_read(name, namefull = namesize + namesize % 2) < 0) {
warnarch("Corrupt swapped pathname", (OFFSET) namefull);
return (-1);
}
if (name[namesize - 1] != '\0') {
warnarch("Bad swapped pathname", (OFFSET) namefull);
return (-1);
}
return (asb->sb_size % 2);
}
/* inascii - read in an ASCII cpio header
*
* DESCRIPTION
*
* Reads an ASCII format cpio header
*
* PARAMETERS
*
* char *magic - magic number to match
* char *name - name of the file which is stored in the header.
* (modified and passed back to caller).
* Stat *asb - stat block for the file (modified and passed back
* to the caller).
*
* RETURNS
*
* Returns zero if successful; -1 otherwise. Assumes that the entire
* magic number has been read.
*/
#ifdef __STDC__
static int inascii(char *magic, char *name, Stat *asb)
#else
static int inascii(magic, name, asb)
char *magic;
char *name;
Stat *asb;
#endif
{
uint namelen;
char header[H_STRLEN + 1];
#ifdef _POSIX_SOURCE
dev_t dummyrdev;
#endif
if (strncmp(magic, M_ASCII, M_STRLEN) != 0) {
return (-1);
}
if (buf_read(header, H_STRLEN) < 0) {
warnarch("Corrupt ASCII header", (OFFSET) H_STRLEN);
return (-1);
}
header[H_STRLEN] = '\0';
if (sscanf(header, H_SCAN, &asb->sb_dev,
&asb->sb_ino, &asb->sb_mode, &asb->sb_uid,
#ifdef _POSIX_SOURCE
&asb->sb_gid, &asb->sb_nlink, &dummyrdev,
#else
&asb->sb_gid, &asb->sb_nlink, &asb->sb_rdev,
#endif
&asb->sb_mtime, &namelen, &asb->sb_size) != H_COUNT) {
warnarch("Bad ASCII header", (OFFSET) H_STRLEN);
return (-1);
}
if (namelen == 0 || namelen >= PATH_MAX) {
warnarch("Bad ASCII pathname length", (OFFSET) H_STRLEN);
return (-1);
}
if (buf_read(name, namelen) < 0) {
warnarch("Corrupt ASCII pathname", (OFFSET) namelen);
return (-1);
}
if (name[namelen - 1] != '\0') {
warnarch("Bad ASCII pathname", (OFFSET) namelen);
return (-1);
}
return (0);
}
/* inbinary - read a binary header
*
* DESCRIPTION
*
* Reads a CPIO format binary header.
*
* PARAMETERS
*
* char *magic - magic number to match
* char *name - name of the file which is stored in the header.
* (modified and passed back to caller).
* Stat *asb - stat block for the file (modified and passed back
* to the caller).
*
* RETURNS
*
* Returns the number of trailing alignment bytes to skip; -1 if
* unsuccessful.
*/
#ifdef __STDC__
static int inbinary(char *magic, char *name, Stat *asb)
#else
static int inbinary(magic, name, asb)
char *magic;
char *name;
Stat *asb;
#endif
{
uint namefull;
Binary binary;
if (*((ushort *) magic) != M_BINARY) {
return (-1);
}
memcpy((char *) &binary,
magic + sizeof(ushort),
M_STRLEN - sizeof(ushort));
if (buf_read((char *) &binary + M_STRLEN - sizeof(ushort),
sizeof(binary) - (M_STRLEN - sizeof(ushort))) < 0) {
warnarch("Corrupt binary header",
(OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort)));
return (-1);
}
asb->sb_dev = binary.b_dev;
asb->sb_ino = binary.b_ino;
asb->sb_mode = binary.b_mode;
asb->sb_uid = binary.b_uid;
asb->sb_gid = binary.b_gid;
asb->sb_nlink = binary.b_nlink;
#ifndef _POSIX_SOURCE
asb->sb_rdev = binary.b_rdev;
#endif
asb->sb_mtime = binary.b_mtime[0] << 16 | binary.b_mtime[1];
asb->sb_size = binary.b_size[0] << 16 | binary.b_size[1];
if (binary.b_name == 0 || binary.b_name >= PATH_MAX) {
warnarch("Bad binary pathname length",
(OFFSET) sizeof(binary) - (M_STRLEN - sizeof(ushort)));
return (-1);
}
if (buf_read(name, namefull = binary.b_name + binary.b_name % 2) < 0) {
warnarch("Corrupt binary pathname", (OFFSET) namefull);
return (-1);
}
if (name[binary.b_name - 1] != '\0') {
warnarch("Bad binary pathname", (OFFSET) namefull);
return (-1);
}
return (asb->sb_size % 2);
}
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