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    Length: 9790 (0x263e)
    Types: TextFile
    Names: »diffarch.c«

└─⟦a05ed705a⟧ Bits:30007078 DKUUG GNU 2/12/89
    └─⟦62a861d28⟧ »./tar-1.07.tar.Z« 
        └─⟦2b95499f1⟧ 
            └─⟦this⟧ »tar-dist/diffarch.c« 

TextFile

/* Diff files from a tar archive.
   Copyright (C) 1988 Free Software Foundation

This file is part of GNU Tar.

GNU Tar 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 1, or (at your option)
any later version.

GNU Tar 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 GNU Tar; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */

/*
 * Diff files from a tar archive.
 *
 * Written 30 April 1987 by John Gilmore, ihnp4!hoptoad!gnu.
 *
 * @(#) diffarch.c 1.10 87/11/11 - gnu
 */

#include <stdio.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>

#ifdef BSD42
#include <sys/file.h>
#endif

#ifdef USG
#include <fcntl.h>
#endif

/* Some systems don't have these #define's -- we fake it here. */
#ifndef O_RDONLY
#define	O_RDONLY	0
#endif
#ifndef	O_NDELAY
#define	O_NDELAY	0
#endif

#ifndef S_IFLNK
#define lstat stat
#endif

extern int errno;			/* From libc.a */
extern char *valloc();			/* From libc.a */

#include "tar.h"
#include "port.h"
#include "rmt.h"

extern union record *head;		/* Points to current tape header */
extern struct stat hstat;		/* Stat struct corresponding */
extern int head_standard;		/* Tape header is in ANSI format */

extern void print_header();
extern void skip_file();

extern FILE *msg_file;

int now_verifying = 0;		/* Are we verifying at the moment? */

char	*diff_name;		/* head->header.name */

int	diff_fd;		/* Descriptor of file we're diffing */

char	*diff_buf = 0;		/* Pointer to area for reading
					   file contents into */

char	*diff_dir;		/* Directory contents for LF_DUMPDIR */

int different = 0;

/*
 * Initialize for a diff operation
 */
diff_init()
{

	/*NOSTRICT*/
	diff_buf = (char *) valloc((unsigned)blocksize);
	if (!diff_buf) {
		msg("could not allocate memory for diff buffer of %d bytes\n",
			blocking);
		exit(EX_ARGSBAD);
	}
}

/*
 * Diff a file against the archive.
 */
void
diff_archive()
{
	register char *data;
	int check, namelen;
	int err;
	long offset;
	struct stat filestat;
	char linkbuf[NAMSIZ+3];
	int compare_chunk();
	int compare_dir();
	dev_t	dev;
	ino_t	ino;
	char *get_dir_contents();
	long from_oct();
	long lseek();

	errno = EPIPE;			/* FIXME, remove perrors */

	saverec(&head);			/* Make sure it sticks around */
	userec(head);			/* And go past it in the archive */
	decode_header(head, &hstat, &head_standard, 1);	/* Snarf fields */

	if(now_verifying)
		fprintf(msg_file,"Verify ");
	/* Print the record from 'head' and 'hstat' */
	if (f_verbose)
		print_header();

	diff_name = head->header.name;
	switch (head->header.linkflag) {

	default:
		msg("Unknown file type '%c' for %s, diffed as normal file\n",
			head->header.linkflag, diff_name);
		/* FALL THRU */

	case LF_OLDNORMAL:
	case LF_NORMAL:
	case LF_CONTIG:
		/*
		 * Appears to be a file.
		 * See if it's really a directory.
		 */
		namelen = strlen(diff_name)-1;
		if (diff_name[namelen] == '/')
			goto really_dir;

		
		if(do_stat(&filestat))
			goto quit;

		if ((filestat.st_mode & S_IFMT) != S_IFREG) {
			fprintf(msg_file, "%s: not a regular file\n",
				diff_name);
			skip_file((long)hstat.st_size);
			different++;
			goto quit;
		}

		filestat.st_mode &= ~S_IFMT;
		if (filestat.st_mode != hstat.st_mode)
			sigh("mode");
		if (filestat.st_uid  != hstat.st_uid)
			sigh("uid");
		if (filestat.st_gid  != hstat.st_gid)
			sigh("gid");
		if (filestat.st_mtime != hstat.st_mtime)
			sigh("mod time");
		if (filestat.st_size != hstat.st_size) {
			sigh("size");
			skip_file((long)hstat.st_size);
			goto quit;
		}

		diff_fd = open(diff_name, O_NDELAY|O_RDONLY);

		if (diff_fd < 0) {
			msg_perror("cannot open %s",diff_name);
			skip_file((long)hstat.st_size);
			different++;
			goto quit;
		}

		wantbytes((long)(hstat.st_size),compare_chunk);

		check = close(diff_fd);
		if (check < 0) {
			msg_perror("Error while closing %s",diff_name);
		}

	quit:
		break;

	case LF_LINK:
		if(do_stat(&filestat))
			break;
		dev = filestat.st_dev;
		ino = filestat.st_ino;
		err = stat(head->header.linkname, &filestat);
		if (err < 0) {
			if (errno==ENOENT) {
				fprintf(msg_file, "%s: does not exist\n",diff_name);
			} else {
				msg_perror("cannot stat file %s",diff_name);
			}
			different++;
			break;
		}
		if(filestat.st_dev!=dev || filestat.st_ino!=ino) {
			fprintf(msg_file, "%s not linked to %s\n",diff_name,head->header.linkname);
			break;
		}
		break;

#ifdef S_IFLNK
	case LF_SYMLINK:
		check = readlink(diff_name, linkbuf,
				 (sizeof linkbuf)-1);
		
		if (check < 0) {
			if (errno == ENOENT) {
				fprintf(msg_file,
					"%s: no such file or directory\n",
					diff_name);
			} else {
				msg_perror("cannot read link %s",diff_name);
			}
			different++;
			break;
		}

		linkbuf[check] = '\0';	/* Null-terminate it */
		if (strncmp(head->header.linkname, linkbuf, check) != 0) {
			fprintf(msg_file, "%s: symlink differs\n",
				head->header.linkname);
			different++;
		}
		break;
#endif

	case LF_CHR:
		hstat.st_mode |= S_IFCHR;
		goto check_node;

#ifdef S_IFBLK
	/* If local system doesn't support block devices, use default case */
	case LF_BLK:
		hstat.st_mode |= S_IFBLK;
		goto check_node;
#endif

#ifdef S_IFIFO
	/* If local system doesn't support FIFOs, use default case */
	case LF_FIFO:
		hstat.st_mode |= S_IFIFO;
		hstat.st_rdev = 0;		/* FIXME, do we need this? */
		goto check_node;
#endif

	check_node:
		/* FIXME, deal with umask */
		if(do_stat(&filestat))
			break;
		if(hstat.st_rdev != filestat.st_rdev) {
			fprintf(msg_file, "%s: device numbers changed\n", diff_name);
			different++;
			break;
		}
		if(hstat.st_mode != filestat.st_mode) {
			fprintf(msg_file, "%s: mode or device-type changed\n", diff_name);
			different++;
			break;
		}
		break;

	case LF_DUMPDIR:
		data=diff_dir=get_dir_contents(diff_name,0);
		wantbytes((long)(hstat.st_size),compare_dir);
		free(data);
		/* FALL THROUGH */

	case LF_DIR:
		/* Check for trailing / */
		namelen = strlen(diff_name)-1;
	really_dir:
		while (namelen && diff_name[namelen] == '/')
			diff_name[namelen--] = '\0';	/* Zap / */

		if(do_stat(&filestat))
			break;
		if((filestat.st_mode&S_IFMT)!=S_IFDIR) {
			fprintf(msg_file, "%s is no longer a directory\n",diff_name);
			different++;
			break;
		}
		if((filestat.st_mode&~S_IFMT) != hstat.st_mode)
			sigh("mode");
		break;

	case LF_VOLHDR:
		break;

	case LF_MULTIVOL:
		namelen = strlen(diff_name)-1;
		if (diff_name[namelen] == '/')
			goto really_dir;

		if(do_stat(&filestat))
			break;

		if ((filestat.st_mode & S_IFMT) != S_IFREG) {
			fprintf(msg_file, "%s: not a regular file\n",
				diff_name);
			skip_file((long)hstat.st_size);
			different++;
			break;
		}

		filestat.st_mode &= ~S_IFMT;
		offset = from_oct(1+12, head->header.offset);
		if (filestat.st_size != hstat.st_size + offset) {
			sigh("size");
			skip_file((long)hstat.st_size);
			different++;
			break;
		}

		diff_fd = open(diff_name, O_NDELAY|O_RDONLY);

		if (diff_fd < 0) {
			msg_perror("cannot open file %s",diff_name);
			skip_file((long)hstat.st_size);
			different++;
			break;
		}
		err = lseek(diff_fd, offset, 0);
		if(err!=offset) {
			msg_perror("cannot seek to %ld in file %s",offset,diff_name);
			different++;
			break;
		}

		wantbytes((long)(hstat.st_size),compare_chunk);

		check = close(diff_fd);
		if (check < 0) {
			msg_perror("Error while closing %s",diff_name);
		}
		break;

	}

	/* We don't need to save it any longer. */
	saverec((union record **) 0);	/* Unsave it */
}

int
compare_chunk(bytes,buffer)
int bytes;
char *buffer;
{
	int err;

	err=read(diff_fd,diff_buf,bytes);
	if(err!=bytes) {
		if(err<0) {
			msg_perror("can't read %s",diff_name);
		} else {
			fprintf(msg_file,"%s: could only read %d of %d bytes\n",err,bytes);
		}
		different++;
		return -1;
	}
	if(bcmp(buffer,diff_buf,bytes)) {
		fprintf(msg_file, "%s: data differs\n",diff_name);
		different++;
		return -1;
	}
	return 0;
}

int
compare_dir(bytes,buffer)
int bytes;
char *buffer;
{
	if(bcmp(buffer,diff_dir,bytes)) {
		fprintf(msg_file, "%s: data differs\n",diff_name);
		different++;
		return -1;
	}
	diff_dir+=bytes;
	return 0;
}

/*
 * Sigh about something that differs.
 */
sigh(what)
	char *what;
{

	fprintf(msg_file, "%s: %s differs\n",
		diff_name, what);
}

verify_volume()
{
	int status;
#ifdef MTIOCTOP
	struct mtop t;
	int er;
#endif

	if(!diff_buf)
		diff_init();
#ifdef MTIOCTOP
	t.mt_op = MTBSF;
	t.mt_count = 1;
	if((er=rmtioctl(archive,MTIOCTOP,&t))<0) {
		if(errno!=EIO || (er=rmtioctl(archive,MTIOCTOP,&t))<0) {
#endif
			if(rmtlseek(archive,0L,0)!=0) {
				/* Lseek failed.  Try a different method */
				msg_perror("Couldn't rewind archive file for verify");
				return;
			}
#ifdef MTIOCTOP
		}
	}
#endif
	ar_reading=1;
	now_verifying = 1;
	fl_read();
	for(;;) {
		status = read_header();
		if(status==0) {
			unsigned n;

			n=0;
			do {
				n++;
				status=read_header();
			} while(status==0);
			msg("VERIFY FAILURE: %d invalid header%s detected!",n,n==1?"":"s");
		}
		if(status==2 || status==EOF)
			break;
		diff_archive();
	}
	ar_reading=0;
	now_verifying = 0;
}

int do_stat(statp)
struct stat *statp;
{
	int err;

	err = f_follow_links ? stat(diff_name, statp) : lstat(diff_name, statp);
	if (err < 0) {
		if (errno==ENOENT) {
			fprintf(msg_file, "%s: does not exist\n",diff_name);
		} else
			msg_perror("can't stat file %s",diff_name);
		skip_file((long)hstat.st_size);
		different++;
		return 1;
	} else
		return 0;
}