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busybox/tar.c

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/* vi: set sw=4 ts=4: */
/*
* Mini tar implementation for busybox
*
* Modifed to use common extraction code used by ar, cpio, dpkg-deb, dpkg
* Glenn McGrath <bug1@optushome.com.au>
*
* Note, that as of BusyBox-0.43, tar has been completely rewritten from the
* ground up. It still has remnents of the old code lying about, but it is
* very different now (i.e., cleaner, less global variables, etc.)
*
* Copyright (C) 1999,2000,2001 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
*
* Based in part in the tar implementation in sash
* Copyright (c) 1999 by David I. Bell
* Permission is granted to use, distribute, or modify this source,
* provided that this copyright notice remains intact.
* Permission to distribute sash derived code under the GPL has been granted.
*
* Based in part on the tar implementation from busybox-0.28
* Copyright (C) 1995 Bruce Perens
* This is free software under the GNU General Public License.
*
* This program 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 of the License, or
* (at your option) any later version.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include <fcntl.h>
#include <getopt.h>
#include <search.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fnmatch.h>
#include <string.h>
#include <errno.h>
#include "busybox.h"
#ifdef BB_FEATURE_TAR_CREATE
/* Tar file constants */
# define TAR_MAGIC "ustar" /* ustar and a null */
# define TAR_VERSION " " /* Be compatable with GNU tar format */
# ifndef MAJOR
# define MAJOR(dev) (((dev)>>8)&0xff)
# define MINOR(dev) ((dev)&0xff)
# endif
static const int TAR_BLOCK_SIZE = 512;
static const int TAR_MAGIC_LEN = 6;
static const int TAR_VERSION_LEN = 2;
/* POSIX tar Header Block, from POSIX 1003.1-1990 */
enum { NAME_SIZE = 100 }; /* because gcc won't let me use 'static const int' */
struct TarHeader
{ /* byte offset */
char name[NAME_SIZE]; /* 0-99 */
char mode[8]; /* 100-107 */
char uid[8]; /* 108-115 */
char gid[8]; /* 116-123 */
char size[12]; /* 124-135 */
char mtime[12]; /* 136-147 */
char chksum[8]; /* 148-155 */
char typeflag; /* 156-156 */
char linkname[NAME_SIZE]; /* 157-256 */
char magic[6]; /* 257-262 */
char version[2]; /* 263-264 */
char uname[32]; /* 265-296 */
char gname[32]; /* 297-328 */
char devmajor[8]; /* 329-336 */
char devminor[8]; /* 337-344 */
char prefix[155]; /* 345-499 */
char padding[12]; /* 500-512 (pad to exactly the TAR_BLOCK_SIZE) */
};
typedef struct TarHeader TarHeader;
/*
** writeTarFile(), writeFileToTarball(), and writeTarHeader() are
** the only functions that deal with the HardLinkInfo structure.
** Even these functions use the xxxHardLinkInfo() functions.
*/
typedef struct HardLinkInfo HardLinkInfo;
struct HardLinkInfo
{
HardLinkInfo *next; /* Next entry in list */
dev_t dev; /* Device number */
ino_t ino; /* Inode number */
short linkCount; /* (Hard) Link Count */
char name[1]; /* Start of filename (must be last) */
};
/* Some info to be carried along when creating a new tarball */
struct TarBallInfo
{
char* fileName; /* File name of the tarball */
int tarFd; /* Open-for-write file descriptor
for the tarball */
struct stat statBuf; /* Stat info for the tarball, letting
us know the inode and device that the
tarball lives, so we can avoid trying
to include the tarball into itself */
int verboseFlag; /* Whether to print extra stuff or not */
char** excludeList; /* List of files to not include */
HardLinkInfo *hlInfoHead; /* Hard Link Tracking Information */
HardLinkInfo *hlInfo; /* Hard Link Info for the current file */
};
typedef struct TarBallInfo TarBallInfo;
/* A nice enum with all the possible tar file content types */
enum TarFileType
{
REGTYPE = '0', /* regular file */
REGTYPE0 = '\0', /* regular file (ancient bug compat)*/
LNKTYPE = '1', /* hard link */
SYMTYPE = '2', /* symbolic link */
CHRTYPE = '3', /* character special */
BLKTYPE = '4', /* block special */
DIRTYPE = '5', /* directory */
FIFOTYPE = '6', /* FIFO special */
CONTTYPE = '7', /* reserved */
GNULONGLINK = 'K', /* GNU long (>100 chars) link name */
GNULONGNAME = 'L', /* GNU long (>100 chars) file name */
};
typedef enum TarFileType TarFileType;
/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
static void
addHardLinkInfo (HardLinkInfo **hlInfoHeadPtr, dev_t dev, ino_t ino,
short linkCount, const char *name)
{
/* Note: hlInfoHeadPtr can never be NULL! */
HardLinkInfo *hlInfo;
hlInfo = (HardLinkInfo *)xmalloc(sizeof(HardLinkInfo)+strlen(name)+1);
if (hlInfo) {
hlInfo->next = *hlInfoHeadPtr;
*hlInfoHeadPtr = hlInfo;
hlInfo->dev = dev;
hlInfo->ino = ino;
hlInfo->linkCount = linkCount;
strcpy(hlInfo->name, name);
}
return;
}
static void
freeHardLinkInfo (HardLinkInfo **hlInfoHeadPtr)
{
HardLinkInfo *hlInfo = NULL;
HardLinkInfo *hlInfoNext = NULL;
if (hlInfoHeadPtr) {
hlInfo = *hlInfoHeadPtr;
while (hlInfo) {
hlInfoNext = hlInfo->next;
free(hlInfo);
hlInfo = hlInfoNext;
}
*hlInfoHeadPtr = NULL;
}
return;
}
/* Might be faster (and bigger) if the dev/ino were stored in numeric order;) */
static HardLinkInfo *
findHardLinkInfo (HardLinkInfo *hlInfo, dev_t dev, ino_t ino)
{
while(hlInfo) {
if ((ino == hlInfo->ino) && (dev == hlInfo->dev))
break;
hlInfo = hlInfo->next;
}
return(hlInfo);
}
/* Put an octal string into the specified buffer.
* The number is zero and space padded and possibly null padded.
* Returns TRUE if successful. */
static int putOctal (char *cp, int len, long value)
{
int tempLength;
char tempBuffer[32];
char *tempString = tempBuffer;
/* Create a string of the specified length with an initial space,
* leading zeroes and the octal number, and a trailing null. */
sprintf (tempString, "%0*lo", len - 1, value);
/* If the string is too large, suppress the leading space. */
tempLength = strlen (tempString) + 1;
if (tempLength > len) {
tempLength--;
tempString++;
}
/* If the string is still too large, suppress the trailing null. */
if (tempLength > len)
tempLength--;
/* If the string is still too large, fail. */
if (tempLength > len)
return FALSE;
/* Copy the string to the field. */
memcpy (cp, tempString, len);
return TRUE;
}
/* Write out a tar header for the specified file/directory/whatever */
static int
writeTarHeader(struct TarBallInfo *tbInfo, const char *header_name,
const char *real_name, struct stat *statbuf)
{
long chksum=0;
struct TarHeader header;
const unsigned char *cp = (const unsigned char *) &header;
ssize_t size = sizeof(struct TarHeader);
memset( &header, 0, size);
strncpy(header.name, header_name, sizeof(header.name));
putOctal(header.mode, sizeof(header.mode), statbuf->st_mode);
putOctal(header.uid, sizeof(header.uid), statbuf->st_uid);
putOctal(header.gid, sizeof(header.gid), statbuf->st_gid);
putOctal(header.size, sizeof(header.size), 0); /* Regular file size is handled later */
putOctal(header.mtime, sizeof(header.mtime), statbuf->st_mtime);
strncpy(header.magic, TAR_MAGIC TAR_VERSION,
TAR_MAGIC_LEN + TAR_VERSION_LEN );
/* Enter the user and group names (default to root if it fails) */
my_getpwuid(header.uname, statbuf->st_uid);
if (! *header.uname)
strcpy(header.uname, "root");
my_getgrgid(header.gname, statbuf->st_gid);
if (! *header.uname)
strcpy(header.uname, "root");
if (tbInfo->hlInfo) {
/* This is a hard link */
header.typeflag = LNKTYPE;
strncpy(header.linkname, tbInfo->hlInfo->name, sizeof(header.linkname));
} else if (S_ISLNK(statbuf->st_mode)) {
char *lpath = xreadlink(real_name);
if (!lpath) /* Already printed err msg inside xreadlink() */
return ( FALSE);
header.typeflag = SYMTYPE;
strncpy(header.linkname, lpath, sizeof(header.linkname));
free(lpath);
} else if (S_ISDIR(statbuf->st_mode)) {
header.typeflag = DIRTYPE;
strncat(header.name, "/", sizeof(header.name));
} else if (S_ISCHR(statbuf->st_mode)) {
header.typeflag = CHRTYPE;
putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
} else if (S_ISBLK(statbuf->st_mode)) {
header.typeflag = BLKTYPE;
putOctal(header.devmajor, sizeof(header.devmajor), MAJOR(statbuf->st_rdev));
putOctal(header.devminor, sizeof(header.devminor), MINOR(statbuf->st_rdev));
} else if (S_ISFIFO(statbuf->st_mode)) {
header.typeflag = FIFOTYPE;
} else if (S_ISREG(statbuf->st_mode)) {
header.typeflag = REGTYPE;
putOctal(header.size, sizeof(header.size), statbuf->st_size);
} else {
error_msg("%s: Unknown file type", real_name);
return ( FALSE);
}
/* Calculate and store the checksum (i.e., the sum of all of the bytes of
* the header). The checksum field must be filled with blanks for the
* calculation. The checksum field is formatted differently from the
* other fields: it has [6] digits, a null, then a space -- rather than
* digits, followed by a null like the other fields... */
memset(header.chksum, ' ', sizeof(header.chksum));
cp = (const unsigned char *) &header;
while (size-- > 0)
chksum += *cp++;
putOctal(header.chksum, 7, chksum);
/* Now write the header out to disk */
if ((size=full_write(tbInfo->tarFd, (char*)&header, sizeof(struct TarHeader))) < 0) {
error_msg(io_error, real_name, strerror(errno));
return ( FALSE);
}
/* Pad the header up to the tar block size */
for (; size<TAR_BLOCK_SIZE; size++) {
write(tbInfo->tarFd, "\0", 1);
}
/* Now do the verbose thing (or not) */
if (tbInfo->verboseFlag==TRUE) {
FILE *vbFd = stdout;
if (tbInfo->tarFd == fileno(stdout)) // If the archive goes to stdout, verbose to stderr
vbFd = stderr;
fprintf(vbFd, "%s\n", header.name);
}
return ( TRUE);
}
static int exclude_file(char **excluded_files, const char *file)
{
int i;
if (excluded_files == NULL)
return 0;
for (i = 0; excluded_files[i] != NULL; i++) {
if (excluded_files[i][0] == '/') {
if (fnmatch(excluded_files[i], file,
FNM_PATHNAME | FNM_LEADING_DIR) == 0)
return 1;
} else {
const char *p;
for (p = file; p[0] != '\0'; p++) {
if ((p == file || p[-1] == '/') && p[0] != '/' &&
fnmatch(excluded_files[i], p,
FNM_PATHNAME | FNM_LEADING_DIR) == 0)
return 1;
}
}
}
return 0;
}
static int writeFileToTarball(const char *fileName, struct stat *statbuf, void* userData)
{
struct TarBallInfo *tbInfo = (struct TarBallInfo *)userData;
const char *header_name;
/*
** Check to see if we are dealing with a hard link.
** If so -
** Treat the first occurance of a given dev/inode as a file while
** treating any additional occurances as hard links. This is done
** by adding the file information to the HardLinkInfo linked list.
*/
tbInfo->hlInfo = NULL;
if (statbuf->st_nlink > 1) {
tbInfo->hlInfo = findHardLinkInfo(tbInfo->hlInfoHead, statbuf->st_dev,
statbuf->st_ino);
if (tbInfo->hlInfo == NULL)
addHardLinkInfo (&tbInfo->hlInfoHead, statbuf->st_dev,
statbuf->st_ino, statbuf->st_nlink, fileName);
}
/* It is against the rules to archive a socket */
if (S_ISSOCK(statbuf->st_mode)) {
error_msg("%s: socket ignored", fileName);
return( TRUE);
}
/* It is a bad idea to store the archive we are in the process of creating,
* so check the device and inode to be sure that this particular file isn't
* the new tarball */
if (tbInfo->statBuf.st_dev == statbuf->st_dev &&
tbInfo->statBuf.st_ino == statbuf->st_ino) {
error_msg("%s: file is the archive; skipping", fileName);
return( TRUE);
}
header_name = fileName;
while (header_name[0] == '/') {
static int alreadyWarned=FALSE;
if (alreadyWarned==FALSE) {
error_msg("Removing leading '/' from member names");
alreadyWarned=TRUE;
}
header_name++;
}
if (strlen(fileName) >= NAME_SIZE) {
error_msg(name_longer_than_foo, NAME_SIZE);
return ( TRUE);
}
if (header_name[0] == '\0')
return TRUE;
# if defined BB_FEATURE_TAR_EXCLUDE
if (exclude_file(tbInfo->excludeList, header_name)) {
return SKIP;
}
# endif //BB_FEATURE_TAR_EXCLUDE
if (writeTarHeader(tbInfo, header_name, fileName, statbuf)==FALSE) {
return( FALSE);
}
/* Now, if the file is a regular file, copy it out to the tarball */
if ((tbInfo->hlInfo == NULL)
&& (S_ISREG(statbuf->st_mode))) {
int inputFileFd;
char buffer[BUFSIZ];
ssize_t size=0, readSize=0;
/* open the file we want to archive, and make sure all is well */
if ((inputFileFd = open(fileName, O_RDONLY)) < 0) {
error_msg("%s: Cannot open: %s", fileName, strerror(errno));
return( FALSE);
}
/* write the file to the archive */
while ( (size = full_read(inputFileFd, buffer, sizeof(buffer))) > 0 ) {
if (full_write(tbInfo->tarFd, buffer, size) != size ) {
/* Output file seems to have a problem */
error_msg(io_error, fileName, strerror(errno));
return( FALSE);
}
readSize+=size;
}
if (size == -1) {
error_msg(io_error, fileName, strerror(errno));
return( FALSE);
}
/* Pad the file up to the tar block size */
for (; (readSize%TAR_BLOCK_SIZE) != 0; readSize++) {
write(tbInfo->tarFd, "\0", 1);
}
close( inputFileFd);
}
return( TRUE);
}
static int writeTarFile(const char* tarName, int verboseFlag, char **argv,
char** excludeList)
{
int tarFd=-1;
int errorFlag=FALSE;
ssize_t size;
struct TarBallInfo tbInfo;
tbInfo.verboseFlag = verboseFlag;
tbInfo.hlInfoHead = NULL;
/* Make sure there is at least one file to tar up. */
if (*argv == NULL)
error_msg_and_die("Cowardly refusing to create an empty archive");
/* Open the tar file for writing. */
if (!strcmp(tarName, "-"))
tbInfo.tarFd = fileno(stdout);
else
tbInfo.tarFd = open (tarName, O_WRONLY | O_CREAT | O_TRUNC, 0644);
if (tbInfo.tarFd < 0) {
perror_msg( "Error opening '%s'", tarName);
freeHardLinkInfo(&tbInfo.hlInfoHead);
return ( FALSE);
}
tbInfo.excludeList=excludeList;
/* Store the stat info for the tarball's file, so
* can avoid including the tarball into itself.... */
if (fstat(tbInfo.tarFd, &tbInfo.statBuf) < 0)
error_msg_and_die(io_error, tarName, strerror(errno));
/* Read the directory/files and iterate over them one at a time */
while (*argv != NULL) {
if (recursive_action(*argv++, TRUE, FALSE, FALSE,
writeFileToTarball, writeFileToTarball,
(void*) &tbInfo) == FALSE) {
errorFlag = TRUE;
}
}
/* Write two empty blocks to the end of the archive */
for (size=0; size<(2*TAR_BLOCK_SIZE); size++) {
write(tbInfo.tarFd, "\0", 1);
}
/* To be pedantically correct, we would check if the tarball
* is smaller than 20 tar blocks, and pad it if it was smaller,
* but that isn't necessary for GNU tar interoperability, and
* so is considered a waste of space */
/* Hang up the tools, close up shop, head home */
close(tarFd);
if (errorFlag == TRUE) {
error_msg("Error exit delayed from previous errors");
freeHardLinkInfo(&tbInfo.hlInfoHead);
return(FALSE);
}
freeHardLinkInfo(&tbInfo.hlInfoHead);
return( TRUE);
}
#endif //tar_create
void append_file_to_list(char *filename, char ***name_list, int *num_of_entries)
{
FILE *src_stream;
char *line;
char *line_ptr;
src_stream = xfopen(filename, "r");
while ((line = get_line_from_file(src_stream)) != NULL) {
line_ptr = last_char_is(line, '\n');
if (line_ptr) {
*line_ptr = '\0';
}
*name_list = realloc(*name_list, sizeof(char *) * (*num_of_entries + 1));
(*name_list)[*num_of_entries] = xstrdup(line);
(*num_of_entries)++;
free(line);
}
fclose(src_stream);
}
#ifdef BB_FEATURE_TAR_EXCLUDE
char **merge_list(char **include_list, char **exclude_list)
{
char **new_include_list = NULL;
int new_include_count = 0;
int include_count = 0;
int exclude_count;
while (include_list[include_count] != NULL) {
int found = FALSE;
exclude_count = 0;
while (exclude_list[exclude_count] != NULL) {
if (strcmp(include_list[include_count], exclude_list[exclude_count]) == 0) {
found = TRUE;
break;
}
exclude_count++;
}
if (found == FALSE) {
new_include_list = realloc(new_include_list, sizeof(char *) * (include_count + 2));
new_include_list[new_include_count] = include_list[include_count];
new_include_count++;
new_include_list[new_include_count] = NULL;
} else {
free(include_list[include_count]);
}
include_count++;
}
return(new_include_list);
}
#endif
int tar_main(int argc, char **argv)
{
enum untar_funct_e {
/* These are optional */
untar_from_file = 1,
untar_from_stdin = 2,
untar_unzip = 4,
/* Require one and only one of these */
untar_list = 8,
untar_create = 16,
untar_extract = 32
};
#ifdef BB_FEATURE_TAR_EXCLUDE
char **exclude_list = NULL;
int exclude_count = 0;
#endif
FILE *src_stream = NULL;
FILE *uncompressed_stream = NULL;
char **include_list = NULL;
char *src_filename = NULL;
char *dst_prefix = NULL;
char *file_list_name = NULL;
int opt;
unsigned short untar_funct = 0;
unsigned short untar_funct_required = 0;
unsigned short extract_function = 0;
int include_count = 0;
int gunzip_pid;
int gz_fd = 0;
if (argc < 2) {
show_usage();
}
/* Prepend '-' to the first argument if required */
if (argv[1][0] != '-') {
char *tmp = xmalloc(strlen(argv[1]) + 2);
tmp[0] = '-';
strcpy(tmp + 1, argv[1]);
argv[1] = tmp;
}
while ((opt = getopt(argc, argv, "ctxT:X:C:f:Opvz")) != -1) {
switch (opt) {
/* One and only one of these is required */
case 'c':
untar_funct_required |= untar_create;
break;
case 't':
untar_funct_required |= untar_list;
extract_function |= extract_list |extract_unconditional;
break;
case 'x':
untar_funct_required |= untar_extract;
extract_function |= (extract_all_to_fs | extract_unconditional | extract_create_leading_dirs);
break;
/* These are optional */
/* Exclude or Include files listed in <filename>*/
#ifdef BB_FEATURE_TAR_EXCLUDE
case 'X':
append_file_to_list(optarg, &exclude_list, &exclude_count);
exclude_list[exclude_count] = NULL;
break;
#endif
case 'T':
// by default a list is an include list
append_file_to_list(optarg, &include_list, &include_count);
break;
case 'C': // Change to dir <optarg>
/* Make sure dst_prefix ends in a '/' */
dst_prefix = concat_path_file(optarg, "/");
break;
case 'f': // archive filename
if (strcmp(optarg, "-") == 0) {
// Untar from stdin to stdout
untar_funct |= untar_from_stdin;
} else {
untar_funct |= untar_from_file;
src_filename = xstrdup(optarg);
}
break;
case 'O':
extract_function |= extract_to_stdout;
break;
case 'p':
break;
case 'v':
if (extract_function & extract_list) {
extract_function |= extract_verbose_list;
}
extract_function |= extract_list;
break;
#ifdef BB_FEATURE_TAR_GZIP
case 'z':
untar_funct |= untar_unzip;
break;
#endif
default:
show_usage();
}
}
/* Make sure the valid arguments were passed */
if (untar_funct_required == 0) {
error_msg_and_die("You must specify one of the `-ctx' options");
}
if ((untar_funct_required != untar_create) &&
(untar_funct_required != untar_extract) &&
(untar_funct_required != untar_list)) {
error_msg_and_die("You may not specify more than one `ctx' option.");
}
untar_funct |= untar_funct_required;
/* Setup an array of filenames to work with */
while (optind < argc) {
include_list = realloc(include_list, sizeof(char *) * (include_count + 2));
include_list[include_count] = xstrdup(argv[optind]);
include_count++;
optind++;
include_list[include_count] = NULL;
}
#ifdef BB_FEATURE_TAR_EXCLUDE
/* Remove excluded files from the include list */
if (exclude_list != NULL) {
/* If both an exclude and include file list was present then
* its an exclude from include list only, if not its really an
* exclude list (and a poor choice of variable names) */
if (include_list == NULL) {
extract_function |= extract_exclude_list;
}
include_list = merge_list(include_list, exclude_list);
}
#endif
if (extract_function & (extract_list | extract_all_to_fs)) {
if (dst_prefix == NULL) {
dst_prefix = xstrdup("./");
}
/* Setup the source of the tar data */
if (untar_funct & untar_from_file) {
src_stream = xfopen(src_filename, "r");
} else {
src_stream = stdin;
}
#ifdef BB_FEATURE_TAR_GZIP
/* Get a binary tree of all the tar file headers */
if (untar_funct & untar_unzip) {
uncompressed_stream = gz_open(src_stream, &gunzip_pid);
} else
#endif // BB_FEATURE_TAR_GZIP
uncompressed_stream = src_stream;
/* extract or list archive */
unarchive(uncompressed_stream, stdout, &get_header_tar, extract_function, dst_prefix, include_list);
fclose(uncompressed_stream);
}
#ifdef BB_FEATURE_TAR_CREATE
/* create an archive */
else if (untar_funct & untar_create) {
int verboseFlag = FALSE;
#ifdef BB_FEATURE_TAR_GZIP
if (untar_funct && untar_unzip) {
error_msg_and_die("Creation of compressed tarfile not internally support by tar, pipe to busybox gunzip");
}
#endif // BB_FEATURE_TAR_GZIP
if (extract_function & extract_verbose_list) {
verboseFlag = TRUE;
}
writeTarFile(src_filename, verboseFlag, &argv[argc - 1], include_list);
}
#endif // BB_FEATURE_TAR_CREATE
/* Cleanups */
#ifdef BB_FEATURE_TAR_GZIP
if (untar_funct & untar_unzip) {
fclose(src_stream);
close(gz_fd);
gz_close(gunzip_pid);
}
#endif // BB_FEATURE_TAR_GZIP
if (src_filename) {
free(src_filename);
}
if (file_list_name) {
free(file_list_name);
}
return(EXIT_SUCCESS);
}
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