data.c   [plain text]


/* 
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of Apple nor the names of any contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
*/
/*
 * Portions Copyright 2006, Apple Computer, Inc.
 * Christopher Ryan <ryanc@apple.com>
*/

#define _FILE_OFFSET_BITS 64
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>
#include <errno.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <inttypes.h>
#include <sys/types.h>

#include "xar.h"
#include "filetree.h"
#include "archive.h"
#include "io.h"
#include "arcmod.h"

#ifndef O_EXLOCK
#define O_EXLOCK 0
#endif

struct _data_context{
	int fd;
	void *buffer;
	size_t length;
	off_t offset;
	off_t total;
};

#define DATA_CONTEXT(x) ((struct _data_context*)(x))

int32_t xar_data_read(xar_t x, xar_file_t f, void *inbuf, size_t bsize, void *context) {
	int32_t r;

	/* read from buffer, rather then fd,if available */
	if(DATA_CONTEXT(context)->length){
		char *readbuf = (char *)DATA_CONTEXT(context)->buffer;
		size_t sizetoread = DATA_CONTEXT(context)->length - DATA_CONTEXT(context)->offset;
		
		if( !sizetoread){
			return 0;
		}
		
		if( sizetoread > bsize ){
			sizetoread = bsize;
		}
		
		/* dont read passed the end of the buffer */
		if((DATA_CONTEXT(context)->offset + sizetoread) > DATA_CONTEXT(context)->length){
			return -1;
			//sizetoread = (DATA_CONTEXT(context)->offset + sizetoread) - DATA_CONTEXT(context)->length;
		}
		
		readbuf += DATA_CONTEXT(context)->offset;
		memcpy(inbuf,readbuf,sizetoread);
		
		DATA_CONTEXT(context)->total += sizetoread;
		DATA_CONTEXT(context)->offset += sizetoread;
		
		return sizetoread;
	}
	
	while(1) {
		r = read(DATA_CONTEXT(context)->fd, inbuf, bsize);
		if( (r < 0) && (errno == EINTR) )
			continue;
		DATA_CONTEXT(context)->total += r;
		return r;
	}		
	
}

int32_t xar_data_write(xar_t x, xar_file_t f, void *buf, size_t len, void *context) {
	int32_t r;
	size_t off = 0;
	
	/* read from buffer, rather then fd,if available */
	if(DATA_CONTEXT(context)->length){
		char *writebuf = (char *)DATA_CONTEXT(context)->buffer;
		
		/* dont write passed the end of the buffer */
		if((DATA_CONTEXT(context)->offset + len) > DATA_CONTEXT(context)->length){
			return -1;
		}
		
		writebuf += DATA_CONTEXT(context)->offset;
		memcpy(writebuf,buf,len);
		
		DATA_CONTEXT(context)->offset += len;
		
		return len;
	}
	
	do {
		r = write(DATA_CONTEXT(context)->fd, ((char *)buf)+off, len-off);
		if( (r < 0) && (errno != EINTR) )
			return r;
		off += r;
	} while( off < len );
	return off;
}

/* xar_data_archive
 * This is the arcmod archival entry point for archiving the file's
 * data into the heap file.
 */
int32_t xar_data_archive(xar_t x, xar_file_t f, const char *file, const char *buffer, size_t len) {
	const char *opt;
	int32_t retval = 0;
	struct _data_context context;
	xar_prop_t tmpp;
	
	memset(&context,0,sizeof(struct _data_context));

	if( !xar_check_prop(x, "data") )
		return 0;

	xar_prop_get(f, "type", &opt);
	if(!opt) return 0;
	if( strcmp(opt, "file") != 0 ) {
		if( strcmp(opt, "hardlink") == 0 ) {
			opt = xar_attr_get(f, "type", "link");
			if( !opt )
				return 0;
			if( strcmp(opt, "original") != 0 )
				return 0;
			/* else, we're an original hardlink, so keep going */
		} else
			return 0;
	}

	if( 0 == len ){
		context.fd = open(file, O_RDONLY);
		if( context.fd < 0 ) {
			xar_err_new(x);
			xar_err_set_file(x, f);
			xar_err_set_string(x, "io: Could not open file");
			xar_err_callback(x, XAR_SEVERITY_NONFATAL, XAR_ERR_ARCHIVE_CREATION);
			return -1;
		}		
	}else{
		context.buffer = (void *)buffer;
		context.length = len;
		context.offset = 0;
	}

#ifdef F_NOCACHE
	fcntl(context.fd, F_NOCACHE, 1);
#endif

	tmpp = xar_prop_pset(f, NULL, "data", NULL);
	retval = xar_attrcopy_to_heap(x, f, tmpp, xar_data_read,(void *)(&context));
	if( context.total == 0 )
		xar_prop_unset(f, "data");

	if(context.fd > 0){
		close(context.fd);
		context.fd = -1;
	}
	
	return retval;
}

int32_t xar_data_extract(xar_t x, xar_file_t f, const char *file, char *buffer, size_t len) {
	const char *opt;
	int32_t retval = 0;
	struct _data_context context;
	xar_prop_t tmpp;
	
	memset(&context,0,sizeof(struct _data_context));
	
	/* Only regular files are copied in and out of the heap here */
	xar_prop_get(f, "type", &opt);
	if( !opt ) return 0;
	if( strcmp(opt, "file") != 0 ) {
		if( strcmp(opt, "hardlink") == 0 ) {
			opt = xar_attr_get(f, "type", "link");
			if( !opt )
				return 0;
			if( strcmp(opt, "original") != 0 )
				return 0; 
			/* else, we're an original hardlink, so keep going */
		} else
			return 0;
	}
	
	if ( len ){
		context.length = len;
		context.buffer = buffer;
		context.offset = 0;
	}else{
		/* mode 600 since other modules may need to operate on the file
		* prior to the real permissions being set.
		*/
		context.fd = open(file, O_RDWR|O_TRUNC|O_EXLOCK, 0600);
		if( context.fd < 0 ) {
			xar_err_new(x);
			xar_err_set_file(x, f);
			xar_err_set_string(x, "io: Could not create file");
			xar_err_callback(x, XAR_SEVERITY_NONFATAL, XAR_ERR_ARCHIVE_EXTRACTION);
			return -1;
		}
		
	}
	
	tmpp = xar_prop_pfirst(f);
	if( tmpp )
		tmpp = xar_prop_find(tmpp, "data");
	if( !tmpp ) {
		close(context.fd);
		return 0;
	}
	retval = xar_attrcopy_from_heap(x, f, tmpp, xar_data_write, (void *)(&context));
	
	if( context.fd > 0 ){		
		close(context.fd);
		context.fd = -1;
	}
	
	return retval;
}

int32_t xar_data_verify(xar_t x, xar_file_t f)
{
	const char *opt;
	struct _data_context context;
	xar_prop_t tmpp;
	
	memset(&context,0,sizeof(struct _data_context));

	/* Only regular files are copied in and out of the heap here */
	xar_prop_get(f, "type", &opt);
	if( !opt ) return 0;
	if( strcmp(opt, "directory") == 0 ) {
		return 0;
	}
	
	tmpp = xar_prop_pfirst(f);
	if( tmpp )
		tmpp = xar_prop_find(tmpp, "data");
	
	if (!tmpp)		// It appears that xar can have truely empty files, aka, no data. We should just fail to verify these files. 
		return 0;	// After all, the checksum of blank is meaningless. So, failing to do so will cause a crash.
	
	return xar_attrcopy_from_heap(x, f, tmpp, NULL , (void *)(&context));
}