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/* Diff files from a tar archive.
Copyright (C) 1988, 1992, 1993 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 2, 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.
*/
#include <stdio.h>
#include <errno.h>
#ifndef STDC_HEADERS
extern int errno;
#endif
#include <sys/types.h>
#ifdef BSD42
#include <sys/file.h>
#else
#ifndef V7
#include <fcntl.h>
#endif
#endif
#ifdef HAVE_SYS_MTIO_H
#include <sys/ioctl.h>
#include <sys/mtio.h>
#endif
#include "tar.h"
#include "port.h"
#include "rmt.h"
#ifndef S_ISLNK
#define lstat stat
#endif
extern void *valloc ();
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 */
void decode_header ();
void diff_sparse_files ();
void fill_in_sparse_array ();
void fl_read ();
long from_oct ();
int do_stat ();
extern void print_header ();
int read_header ();
void saverec ();
void sigh ();
extern void skip_file ();
extern void skip_extended_headers ();
int wantbytes ();
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
*/
void
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 ();
int no_op ();
#ifndef __MSDOS__
dev_t dev;
ino_t ino;
#endif
char *get_dir_contents ();
long from_oct ();
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, current_file_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 (current_file_name) - 1;
if (current_file_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 (!S_ISREG (filestat.st_mode))
{
fprintf (msg_file, "%s: not a regular file\n",
current_file_name);
skip_file ((long) hstat.st_size);
different++;
goto quit;
}
filestat.st_mode &= 07777;
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 (current_file_name, O_NDELAY | O_RDONLY | O_BINARY);
if (diff_fd < 0 && !f_absolute_paths)
{
char tmpbuf[NAMSIZ + 2];
tmpbuf[0] = '/';
strcpy (&tmpbuf[1], current_file_name);
diff_fd = open (tmpbuf, O_NDELAY | O_RDONLY);
}
if (diff_fd < 0)
{
msg_perror ("cannot open %s", current_file_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", current_file_name);
quit:
break;
#ifndef __MSDOS__
case LF_LINK:
if (do_stat (&filestat))
break;
dev = filestat.st_dev;
ino = filestat.st_ino;
err = stat (current_link_name, &filestat);
if (err < 0)
{
if (errno == ENOENT)
{
fprintf (msg_file, "%s: does not exist\n", current_file_name);
}
else
{
msg_perror ("cannot stat file %s", current_file_name);
}
different++;
break;
}
if (filestat.st_dev != dev || filestat.st_ino != ino)
{
fprintf (msg_file, "%s not linked to %s\n", current_file_name, current_link_name);
break;
}
break;
#endif
#ifdef S_ISLNK
case LF_SYMLINK:
{
char linkbuf[NAMSIZ + 3];
check = readlink (current_file_name, linkbuf,
(sizeof linkbuf) - 1);
if (check < 0)
{
if (errno == ENOENT)
{
fprintf (msg_file,
"%s: no such file or directory\n",
current_file_name);
}
else
{
msg_perror ("cannot read link %s", current_file_name);
}
different++;
break;
}
linkbuf[check] = '\0'; /* Null-terminate it */
if (strncmp (current_link_name, linkbuf, check) != 0)
{
fprintf (msg_file, "%s: symlink differs\n",
current_link_name);
different++;
}
}
break;
#endif
#ifdef S_IFCHR
case LF_CHR:
hstat.st_mode |= S_IFCHR;
goto check_node;
#endif
#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_ISFIFO
/* If local system doesn't support FIFOs, use default case */
case LF_FIFO:
#ifdef S_IFIFO
hstat.st_mode |= S_IFIFO;
#endif
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", current_file_name);
different++;
break;
}
#ifdef S_IFMT
if (hstat.st_mode != filestat.st_mode)
#else /* POSIX lossage */
if ((hstat.st_mode & 07777) != (filestat.st_mode & 07777))
#endif
{
fprintf (msg_file, "%s: mode or device-type changed\n", current_file_name);
different++;
break;
}
break;
case LF_DUMPDIR:
data = diff_dir = get_dir_contents (current_file_name, 0);
if (data)
{
wantbytes ((long) (hstat.st_size), compare_dir);
free (data);
}
else
wantbytes ((long) (hstat.st_size), no_op);
/* FALL THROUGH */
case LF_DIR:
/* Check for trailing / */
namelen = strlen (current_file_name) - 1;
really_dir:
while (namelen && current_file_name[namelen] == '/')
current_file_name[namelen--] = '\0'; /* Zap / */
if (do_stat (&filestat))
break;
if (!S_ISDIR (filestat.st_mode))
{
fprintf (msg_file, "%s is no longer a directory\n", current_file_name);
different++;
break;
}
if ((filestat.st_mode & 07777) != (hstat.st_mode & 07777))
sigh ("mode");
break;
case LF_VOLHDR:
break;
case LF_MULTIVOL:
namelen = strlen (current_file_name) - 1;
if (current_file_name[namelen] == '/')
goto really_dir;
if (do_stat (&filestat))
break;
if (!S_ISREG (filestat.st_mode))
{
fprintf (msg_file, "%s: not a regular file\n",
current_file_name);
skip_file ((long) hstat.st_size);
different++;
break;
}
filestat.st_mode &= 07777;
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 (current_file_name, O_NDELAY | O_RDONLY | O_BINARY);
if (diff_fd < 0)
{
msg_perror ("cannot open file %s", current_file_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, current_file_name);
different++;
break;
}
wantbytes ((long) (hstat.st_size), compare_chunk);
check = close (diff_fd);
if (check < 0)
{
msg_perror ("Error while closing %s", current_file_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", current_file_name);
}
else
{
fprintf (msg_file, "%s: could only read %d of %d bytes\n", current_file_name, err, bytes);
}
different++;
return -1;
}
if (bcmp (buffer, diff_buf, bytes))
{
fprintf (msg_file, "%s: data differs\n", current_file_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", current_file_name);
different++;
return -1;
}
diff_dir += bytes;
return 0;
}
/*
* Sigh about something that differs.
*/
void
sigh (what)
char *what;
{
fprintf (msg_file, "%s: %s differs\n",
current_file_name, what);
}
void
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 (current_file_name, statp) : lstat (current_file_name, statp);
if (err < 0)
{
if (errno == ENOENT)
{
fprintf (msg_file, "%s: does not exist\n", current_file_name);
}
else
msg_perror ("can't stat file %s", current_file_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.
*/
void
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 *) ck_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 *) ck_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", current_file_name);
else
fprintf (msg_file, "%s: could only read %d of %d bytes\n",
current_file_name, 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", current_file_name);
else
fprintf (msg_file, "%s: could only read %d of %d bytes\n",
current_file_name, 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", current_file_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.
*/
void
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 *) ck_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 *)
ck_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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