libbb/unarchive.c - codeaurora/busybox - Gitiles

 /*
  *  Copyright (C) 2000 by Glenn McGrath
  *  Copyright (C) 2001 by Laurence Anderson
  *
  *  Based on previous work by busybox developers and others.
  *
  *  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 Library 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 <stdio.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>
 #include <utime.h>
 #include "libbb.h"

 extern void seek_sub_file(FILE *src_stream, const int count);
 extern char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  const int function, const char *prefix);


 #ifdef L_archive_offset
 off_t archive_offset;
 #else
 extern off_t archive_offset;
 #endif

 #ifdef L_seek_sub_file
 void seek_sub_file(FILE *src_stream, const int count)
 {
 	int i;
 	/* Try to fseek as faster */
 	archive_offset += count;
 	if (fseek(src_stream, count, SEEK_CUR) != 0 && errno == ESPIPE) {
 	for (i = 0; i < count; i++) {
 		fgetc(src_stream);
 		}
 	}
 	return;
 }
 #endif


 #ifdef L_extract_archive
 /* Extract the data postioned at src_stream to either filesystem, stdout or
  * buffer depending on the value of 'function' which is defined in libbb.h
  *
  * prefix doesnt have to be just a directory, it may prefix the filename as well.
  *
  * e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
  * '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
  * 'dpkg.' as their prefix
  *
  * For this reason if prefix does point to a dir then it must end with a
  * trailing '/' or else the last dir will be assumed to be the file prefix
  */
 char *extract_archive(FILE *src_stream, FILE *out_stream, const file_header_t *file_entry,
  const int function, const char *prefix)
 {
 	FILE *dst_stream = NULL;
 	char *full_name = NULL;
 	char *buffer = NULL;
 	struct utimbuf t;

 	/* prefix doesnt have to be a proper path it may prepend
 	 * the filename as well */
 	if (prefix != NULL) {
 		/* strip leading '/' in filename to extract as prefix may not be dir */
 		/* Cant use concat_path_file here as prefix might not be a directory */
 		char *path = file_entry->name;
 		if (*path == '/') {
 			path++;
 		}
 		full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
 		strcpy(full_name, prefix);
 		strcat(full_name, path);
 	} else {
 		full_name = file_entry->name;
 	}

 	if (function & extract_to_stdout) {
 		if (S_ISREG(file_entry->mode)) {
 			copy_file_chunk(src_stream, out_stream, file_entry->size);
 			archive_offset += file_entry->size;
 		}
 	}
 	else if (function & extract_one_to_buffer) {
 		if (S_ISREG(file_entry->mode)) {
 			buffer = (char *) xmalloc(file_entry->size + 1);
 			fread(buffer, 1, file_entry->size, src_stream);
 			buffer[file_entry->size] = '\0';
 			archive_offset += file_entry->size;
 			return(buffer);
 		}
 	}
 	else if (function & extract_all_to_fs) {
 		struct stat oldfile;
 		int stat_res;
 		stat_res = lstat (full_name, &oldfile);
 		if (stat_res == 0) { /* The file already exists */
 			if ((function & extract_unconditional) || (oldfile.st_mtime < file_entry->mtime)) {
 				if (!S_ISDIR(oldfile.st_mode)) {
 					unlink(full_name); /* Directories might not be empty etc */
 				}
 			} else {
 				if ((function & extract_quiet) != extract_quiet) {
 					error_msg("%s not created: newer or same age file exists", file_entry->name);
 				}
 				seek_sub_file(src_stream, file_entry->size);
 				return (NULL);
 			}
 		}
 		if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
 			char *parent = dirname(full_name);
 			if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
 				if ((function & extract_quiet) != extract_quiet) {
 					error_msg("couldn't create leading directories");
 				}
 			}
 			free (parent);
 		}
 		switch(file_entry->mode & S_IFMT) {
 			case S_IFREG:
 				if (file_entry->link_name) { /* Found a cpio hard link */
 					if (link(file_entry->link_name, full_name) != 0) {
 						if ((function & extract_quiet) != extract_quiet) {
 							perror_msg("Cannot link from %s to '%s'",
 								file_entry->name, file_entry->link_name);
 						}
 					}
 				} else {
 					if ((dst_stream = wfopen(full_name, "w")) == NULL) {
 						seek_sub_file(src_stream, file_entry->size);
 						return NULL;
 					}
 					archive_offset += file_entry->size;
 					copy_file_chunk(src_stream, dst_stream, file_entry->size);
 					fclose(dst_stream);
 				}
 				break;
 			case S_IFDIR:
 				if (stat_res != 0) {
 					if (mkdir(full_name, file_entry->mode) < 0) {
 						if ((function & extract_quiet) != extract_quiet) {
 							perror_msg("extract_archive: ");
 						}
 					}
 				}
 				break;
 			case S_IFLNK:
 				if (symlink(file_entry->link_name, full_name) < 0) {
 					if ((function & extract_quiet) != extract_quiet) {
 						perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
 					}
 					return NULL;
 				}
 				break;
 			case S_IFSOCK:
 			case S_IFBLK:
 			case S_IFCHR:
 			case S_IFIFO:
 				if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
 					if ((function & extract_quiet) != extract_quiet) {
 						perror_msg("Cannot create node %s", file_entry->name);
 					}
 					return NULL;
 				}
 				break;
 		}

 		/* Changing a symlink's properties normally changes the properties of the
 		 * file pointed to, so dont try and change the date or mode, lchown does
 		 * does the right thing, but isnt available in older versions of libc */
 		if (S_ISLNK(file_entry->mode)) {
 #if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
 			lchown(full_name, file_entry->uid, file_entry->gid);
 #endif
 		} else {
 			if (function & extract_preserve_date) {
 				t.actime = file_entry->mtime;
 				t.modtime = file_entry->mtime;
 				utime(full_name, &t);
 			}
 			chmod(full_name, file_entry->mode);
 			chown(full_name, file_entry->uid, file_entry->gid);
 		}
 	} else {
 		/* If we arent extracting data we have to skip it,
 		 * if data size is 0 then then just do it anyway
 		 * (saves testing for it) */
 		seek_sub_file(src_stream, file_entry->size);
 	}

 	/* extract_list and extract_verbose_list can be used in conjunction
 	 * with one of the above four extraction functions, so do this seperately */
 	if (function & extract_verbose_list) {
 		fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
 			file_entry->uid, file_entry->gid,
 			(int) file_entry->size, time_string(file_entry->mtime));
 	}
 	if ((function & extract_list) || (function & extract_verbose_list)){
 		/* fputs doesnt add a trailing \n, so use fprintf */
 		fprintf(out_stream, "%s\n", file_entry->name);
 	}

 	free(full_name);

 	return(NULL); /* Maybe we should say if failed */
 }
 #endif

 #ifdef L_unarchive
 char *unarchive(FILE *src_stream, FILE *out_stream, file_header_t *(*get_headers)(FILE *),
 	const int extract_function, const char *prefix, char **extract_names)
 {
 	file_header_t *file_entry;
 	int found;
 	int i;
 	char *buffer = NULL;

 	if (extract_names == NULL) {
 		return(NULL);
 	}
 	archive_offset = 0;
 	while ((file_entry = get_headers(src_stream)) != NULL) {
 		found = FALSE;
 		if (extract_names[0] != NULL) {
 			for(i = 0; extract_names[i] != 0; i++) {
 				if (strcmp(extract_names[i], file_entry->name) == 0) {
 					found = TRUE;
 				}
 			}
 			if (!found) {
 				/* seek past the data entry */
 				seek_sub_file(src_stream, file_entry->size);
 				continue;
 			}
 		}
 		buffer = extract_archive(src_stream, out_stream, file_entry, extract_function, prefix);
 	}
 	return(buffer);
 }
 #endif

 #ifdef L_get_header_ar
 file_header_t *get_header_ar(FILE *src_stream)
 {
 	file_header_t *typed;
 	union {
 		char raw[60];
 	 	struct {
  			char name[16];
  			char date[12];
  			char uid[6];
  			char gid[6];
  			char mode[8];
  			char size[10];
  			char magic[2];
  		} formated;
 	} ar;
 	static char *ar_long_names;

 	if (fread(ar.raw, 1, 60, src_stream) != 60) {
 		return(NULL);
 	}
 	archive_offset += 60;
 	/* align the headers based on the header magic */
 	if ((ar.formated.magic[0] != '`') || (ar.formated.magic[1] != '\n')) {
 		/* some version of ar, have an extra '\n' after each data entry,
 		 * this puts the next header out by 1 */
 		if (ar.formated.magic[1] != '`') {
 			error_msg("Invalid magic");
 			return(NULL);
 		}
 		/* read the next char out of what would be the data section,
 		 * if its a '\n' then it is a valid header offset by 1*/
 		archive_offset++;
 		if (fgetc(src_stream) != '\n') {
 			error_msg("Invalid magic");
 			return(NULL);
 		}
 		/* fix up the header, we started reading 1 byte too early */
 		/* raw_header[60] wont be '\n' as it should, but it doesnt matter */
 		memmove(ar.raw, &ar.raw[1], 59);
 	}

 	typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));

 	typed->size = (size_t) atoi(ar.formated.size);
 	/* long filenames have '/' as the first character */
 	if (ar.formated.name[0] == '/') {
 		if (ar.formated.name[1] == '/') {
 			/* If the second char is a '/' then this entries data section
 			 * stores long filename for multiple entries, they are stored
 			 * in static variable long_names for use in future entries */
 			ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
 			fread(ar_long_names, 1, typed->size, src_stream);
 			archive_offset += typed->size;
 			/* This ar entries data section only contained filenames for other records
 			 * they are stored in the static ar_long_names for future reference */
 			return (get_header_ar(src_stream)); /* Return next header */
 		} else if (ar.formated.name[1] == ' ') {
 			/* This is the index of symbols in the file for compilers */
 			seek_sub_file(src_stream, typed->size);
 			return (get_header_ar(src_stream)); /* Return next header */
 		} else {
 			/* The number after the '/' indicates the offset in the ar data section
 			(saved in variable long_name) that conatains the real filename */
 			if (!ar_long_names) {
 				error_msg("Cannot resolve long file name");
 				return (NULL);
 			}
 			typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
 		}
 	} else {
 		/* short filenames */
 		typed->name = xcalloc(1, 16);
 		strncpy(typed->name, ar.formated.name, 16);
 	}
 	typed->name[strcspn(typed->name, " /")]='\0';

 	/* convert the rest of the now valid char header to its typed struct */
 	parse_mode(ar.formated.mode, &typed->mode);
 	typed->mtime = atoi(ar.formated.date);
 	typed->uid = atoi(ar.formated.uid);
 	typed->gid = atoi(ar.formated.gid);

 	return(typed);
 }
 #endif

 #ifdef L_get_header_cpio
 struct hardlinks {
 	file_header_t *entry;
 	int inode;
 	struct hardlinks *next;
 };

 file_header_t *get_header_cpio(FILE *src_stream)
 {
 	file_header_t *cpio_entry = NULL;
 	char cpio_header[110];
 	int namesize;
  	char dummy[16];
  	int major, minor, nlink, inode;
  	static struct hardlinks *saved_hardlinks = NULL;
  	static int pending_hardlinks = 0;

 	if (pending_hardlinks) { /* Deal with any pending hardlinks */
 		struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL;
 		while (tmp) {
 			if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
 				cpio_entry = tmp->entry;
 				if (oldtmp) oldtmp->next = tmp->next; /* Remove item from linked list */
 				else saved_hardlinks = tmp->next;
 				free(tmp);
 				return (cpio_entry);
 			}
 			oldtmp = tmp;
 			tmp = tmp->next;
 		}
 		pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
 	}

 	/* There can be padding before archive header */
 	seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
 	if (fread(cpio_header, 1, 110, src_stream) == 110) {
 		archive_offset += 110;
 		if (strncmp(cpio_header, "07070", 5) != 0) {
 			error_msg("Unsupported format or invalid magic");
 			return(NULL);
 		}
 		switch (cpio_header[5]) {
 			case '2': /* "crc" header format */
 				/* Doesnt do the crc check yet */
 			case '1': /* "newc" header format */
 				cpio_entry = (file_header_t *) xcalloc(1, sizeof(file_header_t));
 				sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
 					dummy, &inode, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
 					&nlink, &cpio_entry->mtime, &cpio_entry->size,
 					dummy, &major, &minor, &namesize, dummy);

 				cpio_entry->name = (char *) xcalloc(1, namesize);
 				fread(cpio_entry->name, 1, namesize, src_stream); /* Read in filename */
 				archive_offset += namesize;
 				/* Skip padding before file contents */
 				seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
 				if (strcmp(cpio_entry->name, "TRAILER!!!") == 0) {
 					printf("%d blocks\n", (int) (archive_offset % 512 ? (archive_offset / 512) + 1 : archive_offset / 512)); /* Always round up */
 					if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
 						struct hardlinks *tmp = saved_hardlinks, *oldtmp = NULL;
 						while (tmp) {
 							error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
 							oldtmp = tmp;
 							tmp = tmp->next;
 							free (oldtmp->entry->name);
 							free (oldtmp->entry);
 							free (oldtmp);
 						}
 						saved_hardlinks = NULL;
 						pending_hardlinks = 0;
 					}
 					return(NULL);
 				}

 				if (S_ISLNK(cpio_entry->mode)) {
 					cpio_entry->link_name = (char *) xcalloc(1, cpio_entry->size + 1);
 					fread(cpio_entry->link_name, 1, cpio_entry->size, src_stream);
 					archive_offset += cpio_entry->size;
 					cpio_entry->size = 0; /* Stop possiable seeks in future */
 				}
 				if (nlink > 1 && !S_ISDIR(cpio_entry->mode)) {
 					if (cpio_entry->size == 0) { /* Put file on a linked list for later */
 						struct hardlinks *new = xmalloc(sizeof(struct hardlinks));
 						new->next = saved_hardlinks;
 						new->inode = inode;
 						new->entry = cpio_entry;
 						saved_hardlinks = new;
 					return(get_header_cpio(src_stream)); /* Recurse to next file */
 					} else { /* Found the file with data in */
 						struct hardlinks *tmp = saved_hardlinks;
 						pending_hardlinks = 1;
 						while (tmp) {
 							if (tmp->inode == inode) {
 								tmp->entry->link_name = xstrdup(cpio_entry->name);
 								nlink--;
 							}
 							tmp = tmp->next;
 						}
 						if (nlink > 1) error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
 					}
 				}
 				cpio_entry->device = (major << 8) | minor;
 				break;
 			default:
 				error_msg("Unsupported format");
 				return(NULL);
 		}
 		if (ferror(src_stream) || feof(src_stream)) {
 			perror_msg("Stream error");
 			return(NULL);
 		}
 	}
 	return(cpio_entry);
 }
 #endif

 #ifdef L_get_header_tar
 file_header_t *get_header_tar(FILE *tar_stream)
 {
 	union {
 		unsigned char raw[512];
 		struct {
 			char name[100];		/*   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[100];	/* 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 */
 		} formated;
 	} tar;
 	file_header_t *tar_entry = NULL;
 	long i;
 	long sum = 0;

 	if (archive_offset % 512 != 0) {
 		seek_sub_file(tar_stream, 512 - (archive_offset % 512));
 	}

 	if (fread(tar.raw, 1, 512, tar_stream) != 512) {
 		error_msg("Couldnt read header");
 		return(NULL);
 	}
 	archive_offset += 512;

 	/* Check header has valid magic, unfortunately some tar files
 	 * have empty (0'ed) tar entries at the end, which will
 	 * cause this to fail, so fail silently for now
 	 */
 	if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
 		return(NULL);
 	}

 	/* Do checksum on headers */
 	for (i =  0; i < 148 ; i++) {
 		sum += tar.raw[i];
 	}
 	sum += ' ' * 8;
 	for (i =  156; i < 512 ; i++) {
 		sum += tar.raw[i];
 	}
 	if (sum != strtol(tar.formated.chksum, NULL, 8)) {
 		error_msg("Invalid tar header checksum");
 		return(NULL);
 	}

 	/* convert to type'ed variables */
 	tar_entry = xcalloc(1, sizeof(file_header_t));
 	tar_entry->name = xstrdup(tar.formated.name);

 	parse_mode(tar.formated.mode, &tar_entry->mode);
 	tar_entry->uid   = strtol(tar.formated.uid, NULL, 8);
 	tar_entry->gid   = strtol(tar.formated.gid, NULL, 8);
 	tar_entry->size  = strtol(tar.formated.size, NULL, 8);
 	tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
 	tar_entry->link_name  = strlen(tar.formated.linkname) ?
 	    xstrdup(tar.formated.linkname) : NULL;
 	tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
 		strtol(tar.formated.devminor, NULL, 8);

 	return(tar_entry);
 }
 #endif

 #ifdef L_deb_extract
 char *deb_extract(const char *package_filename, FILE *out_stream,
 	const int extract_function, const char *prefix, const char *filename)
 {
 	FILE *deb_stream;
 	FILE *uncompressed_stream = NULL;
 	file_header_t *ar_header = NULL;
 	char *output_buffer = NULL;
 	char *ared_file = NULL;
 	char ar_magic[8];
 	char **file_list;
 	int gunzip_pid;

 	if (filename == NULL) {
 		file_list = xmalloc(sizeof(char *));
 		file_list[0] = NULL;
 	} else {
 		file_list = xmalloc(sizeof(char *) * 3);
 		file_list[0] = xstrdup(filename);
 		file_list[1] = NULL;
 	}

 	if (extract_function & extract_control_tar_gz) {
 		ared_file = xstrdup("control.tar.gz");
 	}
 	else if (extract_function & extract_data_tar_gz) {
 		ared_file = xstrdup("data.tar.gz");
 	}

 	/* open the debian package to be worked on */
 	deb_stream = wfopen(package_filename, "r");
 	if (deb_stream == NULL) {
 		return(NULL);
 	}
 	/* set the buffer size */
 	setvbuf(deb_stream, NULL, _IOFBF, 0x8000);

 	/* check ar magic */
 	fread(ar_magic, 1, 8, deb_stream);
 	if (strncmp(ar_magic,"!<arch>",7) != 0) {
 		error_msg_and_die("invalid magic");
 	}
 	archive_offset = 8;

 	while ((ar_header = get_header_ar(deb_stream)) != NULL) {
 		if (strcmp(ared_file, ar_header->name) == 0) {
 			/* open a stream of decompressed data */
 			uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
 			archive_offset = 0;
 			output_buffer = unarchive(uncompressed_stream, out_stream, get_header_tar, extract_function, prefix, file_list);
 		}
 		seek_sub_file(deb_stream, ar_header->size);
 	}
 	gz_close(gunzip_pid);
 	fclose(deb_stream);
 	fclose(uncompressed_stream);
 	free(ared_file);
 	return(output_buffer);
 }
 #endif
	/*
	* Copyright (C) 2000 by Glenn McGrath
	* Copyright (C) 2001 by Laurence Anderson
	*
	* Based on previous work by busybox developers and others.
	*
	* 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 Library 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 <stdio.h>
	#include <errno.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>
	#include <utime.h>
	#include "libbb.h"

	extern void seek_sub_file(FILE *src_stream, const int count);
	extern char extract_archive(FILE src_stream, FILE out_stream, const file_header_t file_entry,
	const int function, const char *prefix);


	#ifdef L_archive_offset
	off_t archive_offset;
	#else
	extern off_t archive_offset;
	#endif

	#ifdef L_seek_sub_file
	void seek_sub_file(FILE *src_stream, const int count)
	{
	int i;
	/* Try to fseek as faster */
	archive_offset += count;
	if (fseek(src_stream, count, SEEK_CUR) != 0 && errno == ESPIPE) {
	for (i = 0; i < count; i++) {
	fgetc(src_stream);
	}
	}
	return;
	}
	#endif



	#ifdef L_extract_archive
	/* Extract the data postioned at src_stream to either filesystem, stdout or
	* buffer depending on the value of 'function' which is defined in libbb.h
	*
	* prefix doesnt have to be just a directory, it may prefix the filename as well.
	*
	* e.g. '/var/lib/dpkg/info/dpkg.' will extract all files to the base bath
	* '/var/lib/dpkg/info/' and all files/dirs created in that dir will have
	* 'dpkg.' as their prefix
	*
	* For this reason if prefix does point to a dir then it must end with a
	* trailing '/' or else the last dir will be assumed to be the file prefix
	*/
	char extract_archive(FILE src_stream, FILE out_stream, const file_header_t file_entry,
	const int function, const char *prefix)
	{
	FILE *dst_stream = NULL;
	char *full_name = NULL;
	char *buffer = NULL;
	struct utimbuf t;

	/* prefix doesnt have to be a proper path it may prepend
	* the filename as well */
	if (prefix != NULL) {
	/* strip leading '/' in filename to extract as prefix may not be dir */
	/* Cant use concat_path_file here as prefix might not be a directory */
	char *path = file_entry->name;
	if (*path == '/') {
	path++;
	}
	full_name = xmalloc(strlen(prefix) + strlen(path) + 1);
	strcpy(full_name, prefix);
	strcat(full_name, path);
	} else {
	full_name = file_entry->name;
	}

	if (function & extract_to_stdout) {
	if (S_ISREG(file_entry->mode)) {
	copy_file_chunk(src_stream, out_stream, file_entry->size);
	archive_offset += file_entry->size;
	}
	}
	else if (function & extract_one_to_buffer) {
	if (S_ISREG(file_entry->mode)) {
	buffer = (char *) xmalloc(file_entry->size + 1);
	fread(buffer, 1, file_entry->size, src_stream);
	buffer[file_entry->size] = '\0';
	archive_offset += file_entry->size;
	return(buffer);
	}
	}
	else if (function & extract_all_to_fs) {
	struct stat oldfile;
	int stat_res;
	stat_res = lstat (full_name, &oldfile);
	if (stat_res == 0) { /* The file already exists */
	if ((function & extract_unconditional) \|\| (oldfile.st_mtime < file_entry->mtime)) {
	if (!S_ISDIR(oldfile.st_mode)) {
	unlink(full_name); /* Directories might not be empty etc */
	}
	} else {
	if ((function & extract_quiet) != extract_quiet) {
	error_msg("%s not created: newer or same age file exists", file_entry->name);
	}
	seek_sub_file(src_stream, file_entry->size);
	return (NULL);
	}
	}
	if (function & extract_create_leading_dirs) { /* Create leading directories with default umask */
	char *parent = dirname(full_name);
	if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
	if ((function & extract_quiet) != extract_quiet) {
	error_msg("couldn't create leading directories");
	}
	}
	free (parent);
	}
	switch(file_entry->mode & S_IFMT) {
	case S_IFREG:
	if (file_entry->link_name) { /* Found a cpio hard link */
	if (link(file_entry->link_name, full_name) != 0) {
	if ((function & extract_quiet) != extract_quiet) {
	perror_msg("Cannot link from %s to '%s'",
	file_entry->name, file_entry->link_name);
	}
	}
	} else {
	if ((dst_stream = wfopen(full_name, "w")) == NULL) {
	seek_sub_file(src_stream, file_entry->size);
	return NULL;
	}
	archive_offset += file_entry->size;
	copy_file_chunk(src_stream, dst_stream, file_entry->size);
	fclose(dst_stream);
	}
	break;
	case S_IFDIR:
	if (stat_res != 0) {
	if (mkdir(full_name, file_entry->mode) < 0) {
	if ((function & extract_quiet) != extract_quiet) {
	perror_msg("extract_archive: ");
	}
	}
	}
	break;
	case S_IFLNK:
	if (symlink(file_entry->link_name, full_name) < 0) {
	if ((function & extract_quiet) != extract_quiet) {
	perror_msg("Cannot create symlink from %s to '%s'", file_entry->name, file_entry->link_name);
	}
	return NULL;
	}
	break;
	case S_IFSOCK:
	case S_IFBLK:
	case S_IFCHR:
	case S_IFIFO:
	if (mknod(full_name, file_entry->mode, file_entry->device) == -1) {
	if ((function & extract_quiet) != extract_quiet) {
	perror_msg("Cannot create node %s", file_entry->name);
	}
	return NULL;
	}
	break;
	}

	/* Changing a symlink's properties normally changes the properties of the
	* file pointed to, so dont try and change the date or mode, lchown does
	* does the right thing, but isnt available in older versions of libc */
	if (S_ISLNK(file_entry->mode)) {
	#if (__GLIBC__ >= 2) && (__GLIBC_MINOR__ >= 1)
	lchown(full_name, file_entry->uid, file_entry->gid);
	#endif
	} else {
	if (function & extract_preserve_date) {
	t.actime = file_entry->mtime;
	t.modtime = file_entry->mtime;
	utime(full_name, &t);
	}
	chmod(full_name, file_entry->mode);
	chown(full_name, file_entry->uid, file_entry->gid);
	}
	} else {
	/* If we arent extracting data we have to skip it,
	* if data size is 0 then then just do it anyway
	* (saves testing for it) */
	seek_sub_file(src_stream, file_entry->size);
	}

	/* extract_list and extract_verbose_list can be used in conjunction
	* with one of the above four extraction functions, so do this seperately */
	if (function & extract_verbose_list) {
	fprintf(out_stream, "%s %d/%d %8d %s ", mode_string(file_entry->mode),
	file_entry->uid, file_entry->gid,
	(int) file_entry->size, time_string(file_entry->mtime));
	}
	if ((function & extract_list) \|\| (function & extract_verbose_list)){
	/* fputs doesnt add a trailing \n, so use fprintf */
	fprintf(out_stream, "%s\n", file_entry->name);
	}

	free(full_name);

	return(NULL); /* Maybe we should say if failed */
	}
	#endif

	#ifdef L_unarchive
	char unarchive(FILE src_stream, FILE out_stream, file_header_t (get_headers)(FILE ),
	const int extract_function, const char prefix, char *extract_names)
	{
	file_header_t *file_entry;
	int found;
	int i;
	char *buffer = NULL;

	if (extract_names == NULL) {
	return(NULL);
	}
	archive_offset = 0;
	while ((file_entry = get_headers(src_stream)) != NULL) {
	found = FALSE;
	if (extract_names[0] != NULL) {
	for(i = 0; extract_names[i] != 0; i++) {
	if (strcmp(extract_names[i], file_entry->name) == 0) {
	found = TRUE;
	}
	}
	if (!found) {
	/* seek past the data entry */
	seek_sub_file(src_stream, file_entry->size);
	continue;
	}
	}
	buffer = extract_archive(src_stream, out_stream, file_entry, extract_function, prefix);
	}
	return(buffer);
	}
	#endif

	#ifdef L_get_header_ar
	file_header_t get_header_ar(FILE src_stream)
	{
	file_header_t *typed;
	union {
	char raw[60];
	struct {
	char name[16];
	char date[12];
	char uid[6];
	char gid[6];
	char mode[8];
	char size[10];
	char magic[2];
	} formated;
	} ar;
	static char *ar_long_names;

	if (fread(ar.raw, 1, 60, src_stream) != 60) {
	return(NULL);
	}
	archive_offset += 60;
	/* align the headers based on the header magic */
	if ((ar.formated.magic[0] != '`') \|\| (ar.formated.magic[1] != '\n')) {
	/* some version of ar, have an extra '\n' after each data entry,
	* this puts the next header out by 1 */
	if (ar.formated.magic[1] != '`') {
	error_msg("Invalid magic");
	return(NULL);
	}
	/* read the next char out of what would be the data section,
	* if its a '\n' then it is a valid header offset by 1*/
	archive_offset++;
	if (fgetc(src_stream) != '\n') {
	error_msg("Invalid magic");
	return(NULL);
	}
	/* fix up the header, we started reading 1 byte too early */
	/* raw_header[60] wont be '\n' as it should, but it doesnt matter */
	memmove(ar.raw, &ar.raw[1], 59);
	}

	typed = (file_header_t *) xcalloc(1, sizeof(file_header_t));

	typed->size = (size_t) atoi(ar.formated.size);
	/* long filenames have '/' as the first character */
	if (ar.formated.name[0] == '/') {
	if (ar.formated.name[1] == '/') {
	/* If the second char is a '/' then this entries data section
	* stores long filename for multiple entries, they are stored
	* in static variable long_names for use in future entries */
	ar_long_names = (char *) xrealloc(ar_long_names, typed->size);
	fread(ar_long_names, 1, typed->size, src_stream);
	archive_offset += typed->size;
	/* This ar entries data section only contained filenames for other records
	* they are stored in the static ar_long_names for future reference */
	return (get_header_ar(src_stream)); /* Return next header */
	} else if (ar.formated.name[1] == ' ') {
	/* This is the index of symbols in the file for compilers */
	seek_sub_file(src_stream, typed->size);
	return (get_header_ar(src_stream)); /* Return next header */
	} else {
	/* The number after the '/' indicates the offset in the ar data section
	(saved in variable long_name) that conatains the real filename */
	if (!ar_long_names) {
	error_msg("Cannot resolve long file name");
	return (NULL);
	}
	typed->name = xstrdup(ar_long_names + atoi(&ar.formated.name[1]));
	}
	} else {
	/* short filenames */
	typed->name = xcalloc(1, 16);
	strncpy(typed->name, ar.formated.name, 16);
	}
	typed->name[strcspn(typed->name, " /")]='\0';

	/* convert the rest of the now valid char header to its typed struct */
	parse_mode(ar.formated.mode, &typed->mode);
	typed->mtime = atoi(ar.formated.date);
	typed->uid = atoi(ar.formated.uid);
	typed->gid = atoi(ar.formated.gid);

	return(typed);
	}
	#endif

	#ifdef L_get_header_cpio
	struct hardlinks {
	file_header_t *entry;
	int inode;
	struct hardlinks *next;
	};

	file_header_t get_header_cpio(FILE src_stream)
	{
	file_header_t *cpio_entry = NULL;
	char cpio_header[110];
	int namesize;
	char dummy[16];
	int major, minor, nlink, inode;
	static struct hardlinks *saved_hardlinks = NULL;
	static int pending_hardlinks = 0;

	if (pending_hardlinks) { /* Deal with any pending hardlinks */
	struct hardlinks tmp = saved_hardlinks, oldtmp = NULL;
	while (tmp) {
	if (tmp->entry->link_name) { /* Found a hardlink ready to be extracted */
	cpio_entry = tmp->entry;
	if (oldtmp) oldtmp->next = tmp->next; /* Remove item from linked list */
	else saved_hardlinks = tmp->next;
	free(tmp);
	return (cpio_entry);
	}
	oldtmp = tmp;
	tmp = tmp->next;
	}
	pending_hardlinks = 0; /* No more pending hardlinks, read next file entry */
	}

	/* There can be padding before archive header */
	seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
	if (fread(cpio_header, 1, 110, src_stream) == 110) {
	archive_offset += 110;
	if (strncmp(cpio_header, "07070", 5) != 0) {
	error_msg("Unsupported format or invalid magic");
	return(NULL);
	}
	switch (cpio_header[5]) {
	case '2': /* "crc" header format */
	/* Doesnt do the crc check yet */
	case '1': /* "newc" header format */
	cpio_entry = (file_header_t *) xcalloc(1, sizeof(file_header_t));
	sscanf(cpio_header, "%6c%8x%8x%8x%8x%8x%8lx%8lx%16c%8x%8x%8x%8c",
	dummy, &inode, &cpio_entry->mode, &cpio_entry->uid, &cpio_entry->gid,
	&nlink, &cpio_entry->mtime, &cpio_entry->size,
	dummy, &major, &minor, &namesize, dummy);

	cpio_entry->name = (char *) xcalloc(1, namesize);
	fread(cpio_entry->name, 1, namesize, src_stream); /* Read in filename */
	archive_offset += namesize;
	/* Skip padding before file contents */
	seek_sub_file(src_stream, (4 - (archive_offset % 4)) % 4);
	if (strcmp(cpio_entry->name, "TRAILER!!!") == 0) {
	printf("%d blocks\n", (int) (archive_offset % 512 ? (archive_offset / 512) + 1 : archive_offset / 512)); /* Always round up */
	if (saved_hardlinks) { /* Bummer - we still have unresolved hardlinks */
	struct hardlinks tmp = saved_hardlinks, oldtmp = NULL;
	while (tmp) {
	error_msg("%s not created: cannot resolve hardlink", tmp->entry->name);
	oldtmp = tmp;
	tmp = tmp->next;
	free (oldtmp->entry->name);
	free (oldtmp->entry);
	free (oldtmp);
	}
	saved_hardlinks = NULL;
	pending_hardlinks = 0;
	}
	return(NULL);
	}

	if (S_ISLNK(cpio_entry->mode)) {
	cpio_entry->link_name = (char *) xcalloc(1, cpio_entry->size + 1);
	fread(cpio_entry->link_name, 1, cpio_entry->size, src_stream);
	archive_offset += cpio_entry->size;
	cpio_entry->size = 0; /* Stop possiable seeks in future */
	}
	if (nlink > 1 && !S_ISDIR(cpio_entry->mode)) {
	if (cpio_entry->size == 0) { /* Put file on a linked list for later */
	struct hardlinks *new = xmalloc(sizeof(struct hardlinks));
	new->next = saved_hardlinks;
	new->inode = inode;
	new->entry = cpio_entry;
	saved_hardlinks = new;
	return(get_header_cpio(src_stream)); /* Recurse to next file */
	} else { /* Found the file with data in */
	struct hardlinks *tmp = saved_hardlinks;
	pending_hardlinks = 1;
	while (tmp) {
	if (tmp->inode == inode) {
	tmp->entry->link_name = xstrdup(cpio_entry->name);
	nlink--;
	}
	tmp = tmp->next;
	}
	if (nlink > 1) error_msg("error resolving hardlink: did you create the archive with GNU cpio 2.0-2.2?");
	}
	}
	cpio_entry->device = (major << 8) \| minor;
	break;
	default:
	error_msg("Unsupported format");
	return(NULL);
	}
	if (ferror(src_stream) \|\| feof(src_stream)) {
	perror_msg("Stream error");
	return(NULL);
	}
	}
	return(cpio_entry);
	}
	#endif

	#ifdef L_get_header_tar
	file_header_t get_header_tar(FILE tar_stream)
	{
	union {
	unsigned char raw[512];
	struct {
	char name[100]; /* 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[100]; /* 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 */
	} formated;
	} tar;
	file_header_t *tar_entry = NULL;
	long i;
	long sum = 0;

	if (archive_offset % 512 != 0) {
	seek_sub_file(tar_stream, 512 - (archive_offset % 512));
	}

	if (fread(tar.raw, 1, 512, tar_stream) != 512) {
	error_msg("Couldnt read header");
	return(NULL);
	}
	archive_offset += 512;

	/* Check header has valid magic, unfortunately some tar files
	* have empty (0'ed) tar entries at the end, which will
	* cause this to fail, so fail silently for now
	*/
	if (strncmp(tar.formated.magic, "ustar", 5) != 0) {
	return(NULL);
	}

	/* Do checksum on headers */
	for (i = 0; i < 148 ; i++) {
	sum += tar.raw[i];
	}
	sum += ' ' * 8;
	for (i = 156; i < 512 ; i++) {
	sum += tar.raw[i];
	}
	if (sum != strtol(tar.formated.chksum, NULL, 8)) {
	error_msg("Invalid tar header checksum");
	return(NULL);
	}

	/* convert to type'ed variables */
	tar_entry = xcalloc(1, sizeof(file_header_t));
	tar_entry->name = xstrdup(tar.formated.name);

	parse_mode(tar.formated.mode, &tar_entry->mode);
	tar_entry->uid = strtol(tar.formated.uid, NULL, 8);
	tar_entry->gid = strtol(tar.formated.gid, NULL, 8);
	tar_entry->size = strtol(tar.formated.size, NULL, 8);
	tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
	tar_entry->link_name = strlen(tar.formated.linkname) ?
	xstrdup(tar.formated.linkname) : NULL;
	tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
	strtol(tar.formated.devminor, NULL, 8);

	return(tar_entry);
	}
	#endif

	#ifdef L_deb_extract
	char deb_extract(const char package_filename, FILE *out_stream,
	const int extract_function, const char prefix, const char filename)
	{
	FILE *deb_stream;
	FILE *uncompressed_stream = NULL;
	file_header_t *ar_header = NULL;
	char *output_buffer = NULL;
	char *ared_file = NULL;
	char ar_magic[8];
	char **file_list;
	int gunzip_pid;

	if (filename == NULL) {
	file_list = xmalloc(sizeof(char *));
	file_list[0] = NULL;
	} else {
	file_list = xmalloc(sizeof(char ) 3);
	file_list[0] = xstrdup(filename);
	file_list[1] = NULL;
	}

	if (extract_function & extract_control_tar_gz) {
	ared_file = xstrdup("control.tar.gz");
	}
	else if (extract_function & extract_data_tar_gz) {
	ared_file = xstrdup("data.tar.gz");
	}

	/* open the debian package to be worked on */
	deb_stream = wfopen(package_filename, "r");
	if (deb_stream == NULL) {
	return(NULL);
	}
	/* set the buffer size */
	setvbuf(deb_stream, NULL, _IOFBF, 0x8000);

	/* check ar magic */
	fread(ar_magic, 1, 8, deb_stream);
	if (strncmp(ar_magic,"!<arch>",7) != 0) {
	error_msg_and_die("invalid magic");
	}
	archive_offset = 8;

	while ((ar_header = get_header_ar(deb_stream)) != NULL) {
	if (strcmp(ared_file, ar_header->name) == 0) {
	/* open a stream of decompressed data */
	uncompressed_stream = gz_open(deb_stream, &gunzip_pid);
	archive_offset = 0;
	output_buffer = unarchive(uncompressed_stream, out_stream, get_header_tar, extract_function, prefix, file_list);
	}
	seek_sub_file(deb_stream, ar_header->size);
	}
	gz_close(gunzip_pid);
	fclose(deb_stream);
	fclose(uncompressed_stream);
	free(ared_file);
	return(output_buffer);
	}
	#endif