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/* 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
#ifndef MSDOS
#include <sys/ioctl.h>
#if !defined(USG) || defined(HAVE_MTIO)
#include <sys/mtio.h>
#endif
#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 void skip_extended_headers();
extern FILE *msg_file;
int now_verifying = 0; /* Are we verifying at the moment? */
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;
/*struct sp_array *sparsearray;
int sp_ar_size = 10;*/
/*
* 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",
blocksize);
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;
int compare_chunk();
int compare_dir();
#ifndef __MSDOS__
dev_t dev;
ino_t ino;
#endif
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 */
/* Print the record from 'head' and 'hstat' */
if (f_verbose) {
if(now_verifying)
fprintf(msg_file,"Verify ");
print_header();
}
switch (head->header.linkflag) {
default:
msg("Unknown file type '%c' for %s, diffed as normal file",
head->header.linkflag, head->header.name);
/* FALL THRU */
case LF_OLDNORMAL:
case LF_NORMAL:
case LF_SPARSE:
case LF_CONTIG:
/*
* Appears to be a file.
* See if it's really a directory.
*/
namelen = strlen(head->header.name)-1;
if (head->header.name[namelen] == '/')
goto really_dir;
if(do_stat(&filestat)) {
if (head->header.isextended)
skip_extended_headers();
skip_file((long)hstat.st_size);
different++;
goto quit;
}
if ((filestat.st_mode & S_IFMT) != S_IFREG) {
fprintf(msg_file, "%s: not a regular file\n",
head->header.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 (head->header.linkflag != LF_SPARSE &&
filestat.st_size != hstat.st_size) {
sigh("size");
skip_file((long)hstat.st_size);
goto quit;
}
diff_fd = open(head->header.name, O_NDELAY|O_RDONLY);
if (diff_fd < 0 && !f_absolute_paths) {
char tmpbuf[NAMSIZ+2];
tmpbuf[0]='/';
strcpy(&tmpbuf[1],head->header.name);
diff_fd=open(tmpbuf, O_NDELAY|O_RDONLY);
}
if (diff_fd < 0) {
msg_perror("cannot open %s",head->header.name);
if (head->header.isextended)
skip_extended_headers();
skip_file((long)hstat.st_size);
different++;
goto quit;
}
/*
* Need to treat sparse files completely differently here.
*/
if (head->header.linkflag == LF_SPARSE)
diff_sparse_files(hstat.st_size);
else
wantbytes((long)(hstat.st_size),compare_chunk);
check = close(diff_fd);
if (check < 0)
msg_perror("Error while closing %s",head->header.name);
quit:
break;
#ifndef __MSDOS__
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",head->header.name);
} else {
msg_perror("cannot stat file %s",head->header.name);
}
different++;
break;
}
if(filestat.st_dev!=dev || filestat.st_ino!=ino) {
fprintf(msg_file, "%s not linked to %s\n",head->header.name,head->header.linkname);
break;
}
break;
#endif
#ifdef S_IFLNK
case LF_SYMLINK:
{
char linkbuf[NAMSIZ+3];
check = readlink(head->header.name, linkbuf,
(sizeof linkbuf)-1);
if (check < 0) {
if (errno == ENOENT) {
fprintf(msg_file,
"%s: no such file or directory\n",
head->header.name);
} else {
msg_perror("cannot read link %s",head->header.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", head->header.name);
different++;
break;
}
if(hstat.st_mode != filestat.st_mode) {
fprintf(msg_file, "%s: mode or device-type changed\n", head->header.name);
different++;
break;
}
break;
case LF_DUMPDIR:
data=diff_dir=get_dir_contents(head->header.name,0);
wantbytes((long)(hstat.st_size),compare_dir);
free(data);
/* FALL THROUGH */
case LF_DIR:
/* Check for trailing / */
namelen = strlen(head->header.name)-1;
really_dir:
while (namelen && head->header.name[namelen] == '/')
head->header.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",head->header.name);
different++;
break;
}
if((filestat.st_mode&~S_IFMT) != hstat.st_mode)
sigh("mode");
break;
case LF_VOLHDR:
break;
case LF_MULTIVOL:
namelen = strlen(head->header.name)-1;
if (head->header.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",
head->header.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(head->header.name, O_NDELAY|O_RDONLY);
if (diff_fd < 0) {
msg_perror("cannot open file %s",head->header.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,head->header.name);
different++;
break;
}
wantbytes((long)(hstat.st_size),compare_chunk);
check = close(diff_fd);
if (check < 0) {
msg_perror("Error while closing %s",head->header.name);
}
break;
}
/* We don't need to save it any longer. */
saverec((union record **) 0); /* Unsave it */
}
int
compare_chunk(bytes,buffer)
long bytes;
char *buffer;
{
int err;
err=read(diff_fd,diff_buf,bytes);
if(err!=bytes) {
if(err<0) {
msg_perror("can't read %s",head->header.name);
} else {
fprintf(msg_file,"%s: could only read %d of %d bytes\n",head->header.name,err,bytes);
}
different++;
return -1;
}
if(bcmp(buffer,diff_buf,bytes)) {
fprintf(msg_file, "%s: data differs\n",head->header.name);
different++;
return -1;
}
return 0;
}
int
compare_dir(bytes,buffer)
long bytes;
char *buffer;
{
if(bcmp(buffer,diff_dir,bytes)) {
fprintf(msg_file, "%s: data differs\n",head->header.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",
head->header.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(head->header.name, statp) : lstat(head->header.name, statp);
if (err < 0) {
if (errno==ENOENT) {
fprintf(msg_file, "%s: does not exist\n",head->header.name);
} else
msg_perror("can't stat file %s",head->header.name);
/* skip_file((long)hstat.st_size);
different++;*/
return 1;
} else
return 0;
}
/*
* JK
* Diff'ing a sparse file with its counterpart on the tar file is a
* bit of a different story than a normal file. First, we must know
* what areas of the file to skip through, i.e., we need to contruct
* a sparsearray, which will hold all the information we need. We must
* compare small amounts of data at a time as we find it.
*/
diff_sparse_files(filesize)
int filesize;
{
int sparse_ind = 0;
char *buf;
int buf_size = RECORDSIZE;
union record *datarec;
int err;
long numbytes;
int amt_read = 0;
int size = filesize;
buf = (char *) malloc(buf_size * sizeof (char));
fill_in_sparse_array();
while (size > 0) {
datarec = findrec();
if (!sparsearray[sparse_ind].numbytes)
break;
/*
* 'numbytes' is nicer to write than
* 'sparsearray[sparse_ind].numbytes' all the time ...
*/
numbytes = sparsearray[sparse_ind].numbytes;
lseek(diff_fd, sparsearray[sparse_ind].offset, 0);
/*
* take care to not run out of room in our buffer
*/
while (buf_size < numbytes) {
buf = (char *) realloc(buf, buf_size * 2 * sizeof(char));
buf_size *= 2;
}
while (numbytes > RECORDSIZE) {
if ((err = read(diff_fd, buf, RECORDSIZE)) != RECORDSIZE) {
if (err < 0)
msg_perror("can't read %s", head->header.name);
else
fprintf(msg_file, "%s: could only read %d of %d bytes\n",
err, numbytes);
break;
}
if (bcmp(buf, datarec->charptr, RECORDSIZE)) {
different++;
break;
}
numbytes -= err;
size -= err;
userec(datarec);
datarec = findrec();
}
if ((err = read(diff_fd, buf, numbytes)) != numbytes) {
if (err < 0)
msg_perror("can't read %s", head->header.name);
else
fprintf(msg_file, "%s: could only read %d of %d bytes\n",
err, numbytes);
break;
}
if (bcmp(buf, datarec->charptr, numbytes)) {
different++;
break;
}
/* amt_read += numbytes;
if (amt_read >= RECORDSIZE) {
amt_read = 0;
userec(datarec);
datarec = findrec();
}*/
userec(datarec);
sparse_ind++;
size -= numbytes;
}
/*
* if the number of bytes read isn't the
* number of bytes supposedly in the file,
* they're different
*/
/* if (amt_read != filesize)
different++;*/
userec(datarec);
free(sparsearray);
if (different)
fprintf(msg_file, "%s: data differs\n", head->header.name);
}
/*
* JK
* This routine should be used more often than it is ... look into
* that. Anyhow, what it does is translate the sparse information
* on the header, and in any subsequent extended headers, into an
* array of structures with true numbers, as opposed to character
* strings. It simply makes our life much easier, doing so many
* comparisong and such.
*/
fill_in_sparse_array()
{
int ind;
/*
* allocate space for our scratch space; it's initially
* 10 elements long, but can change in this routine if
* necessary
*/
sp_array_size = 10;
sparsearray = (struct sp_array *) malloc(sp_array_size * sizeof(struct sp_array));
/*
* there are at most five of these structures in the header
* itself; read these in first
*/
for (ind = 0; ind < SPARSE_IN_HDR; ind++) {
if (!head->header.sp[ind].numbytes)
break;
sparsearray[ind].offset =
from_oct(1+12, head->header.sp[ind].offset);
sparsearray[ind].numbytes =
from_oct(1+12, head->header.sp[ind].numbytes);
}
/*
* if the header's extended, we gotta read in exhdr's till
* we're done
*/
if (head->header.isextended) {
/* how far into the sparsearray we are 'so far' */
static int so_far_ind = SPARSE_IN_HDR;
union record *exhdr;
for (;;) {
exhdr = findrec();
for (ind = 0; ind < SPARSE_EXT_HDR; ind++) {
if (ind+so_far_ind > sp_array_size-1) {
/*
* we just ran out of room in our
* scratch area - realloc it
*/
sparsearray = (struct sp_array *)
realloc(sparsearray,
sp_array_size*2*sizeof(struct sp_array));
sp_array_size *= 2;
}
/*
* convert the character strings into longs
*/
sparsearray[ind+so_far_ind].offset =
from_oct(1+12, exhdr->ext_hdr.sp[ind].offset);
sparsearray[ind+so_far_ind].numbytes =
from_oct(1+12, exhdr->ext_hdr.sp[ind].numbytes);
}
/*
* if this is the last extended header for this
* file, we can stop
*/
if (!exhdr->ext_hdr.isextended)
break;
else {
so_far_ind += SPARSE_EXT_HDR;
userec(exhdr);
}
}
/* be sure to skip past the last one */
userec(exhdr);
}
}
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