busybox/archival/ar.c

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/* vi: set sw=4 ts=4: */
/*
* Mini ar implementation for busybox
*
* Copyright (C) 2000 by Glenn McGrath
* Written by Glenn McGrath <bug1@netconnect.com.au> 1 June 2000
*
* Based in part on BusyBox tar, Debian dpkg-deb and GNU ar.
*
* 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
*
* Last modified 10 June 2000
*/
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <ctype.h>
#include <time.h>
#include <utime.h>
#include <sys/types.h>
#include "internal.h"
#define AR_BLOCK_SIZE 60
#define AR_PRESERVE_DATE 1 /* preserve original dates */
#define AR_VERBOSE 2 /* be verbose */
#define AR_DISPLAY 4 /* display contents */
#define AR_EXT_TO_FILE 8 /* extract contents of archive */
#define AR_EXT_TO_STDOUT 16 /* extract to stdout */
#define BB_DECLARE_EXTERN
#define bb_need_io_error
#include "messages.c"
struct ArHeader { /* Byte Offset */
char ar_name[16]; /* 0-15 */
char ar_date[12]; /* 16-27 */
char ar_uid[6], ar_gid[6]; /* 28-39 */
char ar_mode[8]; /* 40-47 */
char ar_size[10]; /* 48-57 */
char ar_fmag[2]; /* 58-59 */
};
typedef struct ArHeader ArHeader;
struct ArInfo {
char name[17]; /* File name */
time_t date; /* long int, No of seconds since epoch */
uid_t uid; /* unsigned int, Numeric UID */
gid_t gid; /* unsigned int, Numeric GID */
mode_t mode; /* unsigned int, Unix mode */
size_t size; /* int, Size of the file */
};
typedef struct ArInfo ArInfo;
static const char ar_usage[] = "ar [optxvV] archive [filenames] \n"
#ifndef BB_FEATURE_TRIVIAL_HELP
"\nExtract or list files from an ar archive.\n\n"
"Options:\n"
"\to\t\tpreserve original dates\n"
"\tp\t\textract to stdout\n"
"\tt\t\tlist\n"
"\tx\t\textract\n"
"\tv\t\tverbosely list files processed\n"
#endif
;
/*
* Display details of a file, verbosly if funct=2
*/
static void displayEntry(struct ArInfo *entry, int funct)
{
/* TODO convert mode to string */
if ((funct & AR_VERBOSE) == AR_VERBOSE)
printf("%i %i/%i %8i %s ", entry->mode, entry->uid, entry->gid,
entry->size, timeString(entry->date));
printf("%s\n", entry->name);
}
/* this is from tar.c remove later*/
static long getOctal(const char *cp, int size)
{
long val = 0;
for(;(size > 0) && (*cp == ' '); cp++, size--);
if ((size == 0) || !isOctal(*cp))
return -1;
for(; (size > 0) && isOctal(*cp); size--) {
val = val * 8 + *cp++ - '0';
}
for (;(size > 0) && (*cp == ' '); cp++, size--);
if ((size > 0) && *cp)
return -1;
return val;
}
/*
* Converts from the char based struct to a new struct with stricter types
*/
static int processArHeader(struct ArHeader *rawHeader, struct ArInfo *header)
{
int count2;
int count;
/* check end of header marker is valid */
if ((rawHeader->ar_fmag[0]!='`') || (rawHeader->ar_fmag[1]!='\n'))
return(FALSE);
/* convert filename */
for (count = 0; count < 16; count++) {
/* allow spaces in filename except at the end */
if (rawHeader->ar_name[count] == ' ') {
for (count2 = count; count2 < 16; count2++)
if (!isspace(rawHeader->ar_name[count2]))
break;
if (count2 >= 16)
break;
}
/* GNU ar uses '/' as an end of filename marker */
if (rawHeader->ar_name[count] == '/')
break;
header->name[count] = rawHeader->ar_name[count];
}
header->name[count] = '\0';
header->date = atoi(rawHeader->ar_date);
header->uid = atoi(rawHeader->ar_uid);
header->gid = atoi(rawHeader->ar_gid);
header->mode = getOctal(rawHeader->ar_mode, sizeof(rawHeader->ar_mode));
header->size = atoi(rawHeader->ar_size);
return (TRUE);
}
/*
* Copy size bytes from current position if srcFd to current position in dstFd
* taken from tarExtractRegularFile in tar.c, remove later
*/
static int copySubFile(int srcFd, int dstFd, int copySize)
{
int readSize, writeSize, doneSize;
char buffer[BUFSIZ];
while (copySize > 0) {
if (copySize > BUFSIZ)
readSize = BUFSIZ;
else
readSize = copySize;
writeSize = fullRead(srcFd, buffer, readSize);
if (writeSize <= 0) {
errorMsg(io_error, "copySubFile :", strerror(errno));
return (FALSE);
}
doneSize = fullWrite(dstFd, buffer, writeSize);
if (doneSize <= 0) {
errorMsg(io_error, "copySubFile :", strerror(errno));
return (FALSE);
}
copySize -= doneSize;
}
return (TRUE);
}
/*
* Extract the file described in ArInfo to the specified path
* set the new files uid, gid and mode
*/
static int extractToFile(struct ArInfo *file, int funct, int srcFd, const char *path)
{
int dstFd, temp;
struct stat tmpStat;
char *pathname = NULL;
struct utimbuf newtime;
if ((temp = isDirectory(path, TRUE, &tmpStat)) != TRUE) {
if (!createPath(path, 0777)) {
fatalError("Cannot extract to specified path");
return (FALSE);
}
}
temp = (strlen(path) + 16);
pathname = (char *) xmalloc(temp);
pathname = strcpy(pathname, path);
pathname = strcat(pathname, file->name);
dstFd = device_open(pathname, O_WRONLY | O_CREAT);
temp = copySubFile(srcFd, dstFd, file->size);
fchown(dstFd, file->uid, file->gid);
fchmod(dstFd, file->mode);
close(dstFd);
if ((funct&AR_PRESERVE_DATE)==AR_PRESERVE_DATE)
newtime.modtime=file->date;
else
newtime.modtime=time(0);
newtime.actime=time(0);
temp = utime(pathname, &newtime);
return (TRUE);
}
/*
* Return a file descriptor for the specified file and do error checks
*/
static int getArFd(char *filename)
{
int arFd;
char arVersion[8];
arFd = open(filename, O_RDONLY);
if (arFd < 0) {
errorMsg("Error opening '%s': %s\n", filename, strerror(errno));
return (FALSE);
}
if (fullRead(arFd, arVersion, 8) <= 0) {
errorMsg( "ar: Unexpected EOF in archive\n");
return (FALSE);
}
if (strncmp(arVersion,"!<arch>",7) != 0) {
errorMsg("ar header fails check ");
return(FALSE);
}
return arFd;
}
/*
* Step through the ar file and process it one entry at a time
* fileList[0] is the name of the ar archive
* fileList[1] and up are filenames to extract from the archive
* funct contains flags to specify the actions to be performed
*/
static int readArFile(char *fileList[16], int fileListSize, int funct)
{
int arFd, status, extFileFlag, i, lastOffset=0;
ArHeader rawArHeader;
ArInfo arEntry;
/* open the ar archive */
arFd=getArFd(fileList[0]);
/* read the first header, then loop until ono more headers */
while ((status = fullRead(arFd, (char *) &rawArHeader, AR_BLOCK_SIZE))
== AR_BLOCK_SIZE) {
/* check the header is valid, if not try reading the header
agian with an offset of 1, needed as some ar archive end
with a '\n' which isnt counted in specified file size */
if ((status=processArHeader(&rawArHeader, &arEntry))==FALSE ) {
if ((i=lseek(arFd, 0, SEEK_CUR))==(lastOffset+60))
lseek(arFd, lastOffset+1, SEEK_SET);
else
return(FALSE);
}
else {
extFileFlag=0;
if (funct&AR_DISPLAY)
displayEntry(&arEntry, funct);
/* check file was specified to be extracted only if
some file were specified */
if ((funct&AR_EXT_TO_FILE) || (funct&AR_EXT_TO_STDOUT)){
if (fileListSize==1)
extFileFlag=1;
else {
for( i=1; i<=fileListSize; i++)
if ((status=(strcmp(fileList[i],arEntry.name)))==0)
extFileFlag=1;
}
}
if (extFileFlag==1) {
if (funct&AR_EXT_TO_FILE)
extractToFile(&arEntry, funct, arFd, "./");
else
copySubFile(arFd,fileno(stdout),arEntry.size);
}
else
lseek(arFd, arEntry.size, SEEK_CUR);
lastOffset=lseek(arFd, 0, SEEK_CUR);
} /* if processArHeader */
} /* while */
return (TRUE);
}
extern int ar_main(int argc, char **argv)
{
int funct = 0, ret=0, i=0;
char *fileList[16], c, *opt_ptr;
if (argc < 2)
usage(ar_usage);
opt_ptr = argv[1];
if (*opt_ptr == '-')
++opt_ptr;
while ((c = *opt_ptr++) != '\0') {
switch (c) {
case 'o':
funct = funct | AR_PRESERVE_DATE;
break;
case 'v':
funct = funct | AR_VERBOSE;
break;
case 't':
funct = funct | AR_DISPLAY;
break;
case 'x':
funct = funct | AR_EXT_TO_FILE;
break;
case 'p':
funct = funct | AR_EXT_TO_STDOUT;
break;
default:
usage(ar_usage);
}
}
for(i=0; i<(argc-2); i++)
fileList[i]=argv[i+2];
if (funct > 3)
ret = readArFile(fileList, (argc-2), funct);
return (ret);
}