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busybox/libbb/unarchive.c

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/*
* 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 <fnmatch.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 (strncmp("./", path, 2) == 0) {
path += 2;
if (strlen(path) == 0) {
return(NULL);
}
}
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 *buf, *parent;
buf = xstrdup(full_name);
parent = dirname(buf);
if (make_directory (parent, -1, FILEUTILS_RECUR) != 0) {
if ((function & extract_quiet) != extract_quiet) {
error_msg("couldn't create leading directories");
}
}
free (buf);
}
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: %s", full_name);
}
}
}
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", full_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 **include_name, char **exclude_name)
{
file_header_t *file_entry;
int extract_flag = TRUE;
int i;
char *buffer = NULL;
archive_offset = 0;
while ((file_entry = get_headers(src_stream)) != NULL) {
if (include_name != NULL) {
extract_flag = FALSE;
for(i = 0; include_name[i] != 0; i++) {
if (fnmatch(include_name[i], file_entry->name, FNM_LEADING_DIR) == 0) {
extract_flag = TRUE;
break;
}
}
} else {
extract_flag = TRUE;
}
/* If the file entry is in the exclude list dont extract it */
if (exclude_name != NULL) {
for(i = 0; exclude_name[i] != 0; i++) {
if (fnmatch(exclude_name[i], file_entry->name, FNM_LEADING_DIR) == 0) {
extract_flag = FALSE;
break;
}
}
}
if (extract_flag == TRUE) {
buffer = extract_archive(src_stream, out_stream, file_entry, extract_function, prefix);
} else {
/* seek past the data entry */
seek_sub_file(src_stream, file_entry->size);
}
free(file_entry->name); /* may be null, but doesn't matter */
if (file_entry->link_name) {
free(file_entry->link_name);
}
free(file_entry);
}
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, (unsigned int*)&cpio_entry->mode,
(unsigned int*)&cpio_entry->uid, (unsigned int*)&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 sum = 0;
long i;
if (archive_offset % 512 != 0) {
seek_sub_file(tar_stream, 512 - (archive_offset % 512));
}
if (fread(tar.raw, 1, 512, tar_stream) != 512) {
/* Unfortunatly its common for tar files to have all sorts of
* trailing garbage, fail silently */
// 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 **file_list = NULL;
char *output_buffer = NULL;
char *ared_file = NULL;
char ar_magic[8];
int gunzip_pid;
if (filename != NULL) {
file_list = xmalloc(sizeof(char *) * 2);
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, NULL);
}
seek_sub_file(deb_stream, ar_header->size);
free(ar_header->name);
free(ar_header);
}
gz_close(gunzip_pid);
fclose(deb_stream);
fclose(uncompressed_stream);
free(ared_file);
if (filename != NULL) {
free(file_list[0]);
free(file_list);
}
return(output_buffer);
}
#endif
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