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freebsd-dev/gnu/usr.bin/tar/create.c
Jordan K. Hubbard 13ea765008 Gnu tar has problems creating an archive which contains a file with a hard 
link to another file which has a long (>=100 char) name.  When listing such
an archive, the name of the link is truncated to 99 characters, and when
extracting such an archive, an error is reported because it is trying to
create a hard link to a file which doesn't exist.  This patch fixes that
problem and has also been sent to the GNU maintainers.

Closes PR#1992

Submitted-By: David Dawes <dawes@landfill.physics.usyd.edu.au>
1996-11-12 18:15:42 +00:00

1481 lines
34 KiB
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/* Create a tar archive.
Copyright (C) 1985, 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. */
/*
* Create a tar archive.
*
* Written 25 Aug 1985 by John Gilmore, ihnp4!hoptoad!gnu.
*/
#ifdef _AIX
#pragma alloca
#endif
#include <sys/types.h>
#include <stdio.h>
#include <errno.h>
#ifndef STDC_HEADERS
extern int errno;
#endif
#ifdef BSD42
#include <sys/file.h>
#else
#ifndef V7
#include <fcntl.h>
#endif
#endif
#include "tar.h"
#include "port.h"
#ifndef __MSDOS__
#include <pwd.h>
#include <grp.h>
#endif
#if defined (_POSIX_VERSION)
#include <utime.h>
#else
struct utimbuf
{
long actime;
long modtime;
};
#endif
extern struct stat hstat; /* Stat struct corresponding */
#ifndef __MSDOS__
extern dev_t ar_dev;
extern ino_t ar_ino;
#endif
/* JF */
extern struct name *gnu_list_name;
/*
* If there are no symbolic links, there is no lstat(). Use stat().
*/
#ifndef S_ISLNK
#define lstat stat
#endif
extern void print_header ();
union record *start_header ();
void blank_name_list ();
int check_exclude ();
PTR ck_malloc ();
PTR ck_realloc ();
void clear_buffer ();
void close_archive ();
void collect_and_sort_names ();
int confirm ();
int deal_with_sparse ();
void find_new_file_size ();
void finish_header ();
int finish_sparse_file ();
void finduname ();
void findgname ();
int is_dot_or_dotdot ();
void open_archive ();
char *name_next ();
void name_close ();
void to_oct ();
void dump_file ();
void write_dir_file ();
void write_eot ();
void write_long ();
int zero_record ();
/* This code moved from tar.h since create.c is the only file that cares
about 'struct link's. This means that other files might not have to
include sys/types.h any more. */
struct link
{
struct link *next;
dev_t dev;
ino_t ino;
short linkcount;
char name[1];
};
struct link *linklist; /* Points to first link in list */
static nolinks; /* Gets set if we run out of RAM */
/*
* "Scratch" space to store the information about a sparse file before
* writing the info into the header or extended header
*/
/* struct sp_array *sparsearray;*/
/* number of elts storable in the sparsearray */
/*int sparse_array_size = 10;*/
void
create_archive ()
{
register char *p;
char *name_from_list ();
open_archive (0); /* Open for writing */
if (f_gnudump)
{
char *buf = ck_malloc (PATH_MAX);
char *q, *bufp;
collect_and_sort_names ();
while (p = name_from_list ())
dump_file (p, -1, 1);
/* if(!f_dironly) { */
blank_name_list ();
while (p = name_from_list ())
{
strcpy (buf, p);
if (p[strlen (p) - 1] != '/')
strcat (buf, "/");
bufp = buf + strlen (buf);
for (q = gnu_list_name->dir_contents; q && *q; q += strlen (q) + 1)
{
if (*q == 'Y')
{
strcpy (bufp, q + 1);
dump_file (buf, -1, 1);
}
}
}
/* } */
free (buf);
}
else
{
while (p = name_next (1))
dump_file (p, -1, 1);
}
write_eot ();
close_archive ();
if (f_gnudump)
write_dir_file ();
name_close ();
}
/*
* Dump a single file. If it's a directory, recurse.
* Result is 1 for success, 0 for failure.
* Sets global "hstat" to stat() output for this file.
*/
void
dump_file (p, curdev, toplevel)
char *p; /* File name to dump */
int curdev; /* Device our parent dir was on */
int toplevel; /* Whether we are a toplevel call */
{
union record *header;
char type;
extern char *save_name; /* JF for multi-volume support */
extern long save_totsize;
extern long save_sizeleft;
union record *exhdr;
char save_linkflag;
extern time_t new_time;
int critical_error = 0;
struct utimbuf restore_times;
/* int sparse_ind = 0;*/
if (f_confirm && !confirm ("add", p))
return;
/*
* Use stat if following (rather than dumping) 4.2BSD's
* symbolic links. Otherwise, use lstat (which, on non-4.2
* systems, is #define'd to stat anyway.
*/
#ifdef STX_HIDDEN /* AIX */
if (0 != f_follow_links ?
statx (p, &hstat, STATSIZE, STX_HIDDEN) :
statx (p, &hstat, STATSIZE, STX_HIDDEN | STX_LINK))
#else
if (0 != f_follow_links ? stat (p, &hstat) : lstat (p, &hstat))
#endif
{
badperror:
msg_perror ("can't add file %s", p);
badfile:
if (!f_ignore_failed_read || critical_error)
errors++;
return;
}
restore_times.actime = hstat.st_atime;
restore_times.modtime = hstat.st_mtime;
#ifdef S_ISHIDDEN
if (S_ISHIDDEN (hstat.st_mode))
{
char *new = (char *) alloca (strlen (p) + 2);
if (new)
{
strcpy (new, p);
strcat (new, "@");
p = new;
}
}
#endif
/* See if we only want new files, and check if this one is too old to
put in the archive. */
if (f_new_files
&& !f_gnudump
&& new_time > hstat.st_mtime
&& !S_ISDIR (hstat.st_mode)
&& (f_new_files > 1 || new_time > hstat.st_ctime))
{
if (curdev == -1)
{
msg ("%s: is unchanged; not dumped", p);
}
return;
}
#ifndef __MSDOS__
/* See if we are trying to dump the archive */
if (ar_dev && hstat.st_dev == ar_dev && hstat.st_ino == ar_ino)
{
msg ("%s is the archive; not dumped", p);
return;
}
#endif
/*
* Check for multiple links.
*
* We maintain a list of all such files that we've written so
* far. Any time we see another, we check the list and
* avoid dumping the data again if we've done it once already.
*/
if (hstat.st_nlink > 1
&& (S_ISREG (hstat.st_mode)
#ifdef S_ISCTG
|| S_ISCTG (hstat.st_mode)
#endif
#ifdef S_ISCHR
|| S_ISCHR (hstat.st_mode)
#endif
#ifdef S_ISBLK
|| S_ISBLK (hstat.st_mode)
#endif
#ifdef S_ISFIFO
|| S_ISFIFO (hstat.st_mode)
#endif
))
{
register struct link *lp;
/* First quick and dirty. Hashing, etc later FIXME */
for (lp = linklist; lp; lp = lp->next)
{
if (lp->ino == hstat.st_ino &&
lp->dev == hstat.st_dev)
{
char *link_name = lp->name;
/* We found a link. */
while (!f_absolute_paths && *link_name == '/')
{
static int link_warn = 0;
if (!link_warn)
{
msg ("Removing leading / from absolute links");
link_warn++;
}
link_name++;
}
if (strlen(link_name) >= NAMSIZ)
write_long (link_name, LF_LONGLINK);
current_link_name = link_name;
hstat.st_size = 0;
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
strncpy (header->header.arch_linkname,
link_name, NAMSIZ);
/* Force null truncated */
header->header.arch_linkname[NAMSIZ - 1] = 0;
header->header.linkflag = LF_LINK;
finish_header (header);
/* FIXME: Maybe remove from list after all links found? */
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return; /* We dumped it */
}
}
/* Not found. Add it to the list of possible links. */
lp = (struct link *) ck_malloc ((unsigned) (sizeof (struct link) + strlen (p)));
if (!lp)
{
if (!nolinks)
{
msg (
"no memory for links, they will be dumped as separate files");
nolinks++;
}
}
lp->ino = hstat.st_ino;
lp->dev = hstat.st_dev;
strcpy (lp->name, p);
lp->next = linklist;
linklist = lp;
}
/*
* This is not a link to a previously dumped file, so dump it.
*/
if (S_ISREG (hstat.st_mode)
#ifdef S_ISCTG
|| S_ISCTG (hstat.st_mode)
#endif
)
{
int f; /* File descriptor */
long bufsize, count;
long sizeleft;
register union record *start;
int header_moved;
char isextended = 0;
int upperbound;
/* int end_nulls = 0; */
header_moved = 0;
#ifdef BSD42
if (f_sparse_files)
{
/*
* JK - This is the test for sparseness: whether the
* "size" of the file matches the number of blocks
* allocated for it. If there is a smaller number
* of blocks that would be necessary to accommodate
* a file of this size, we have a sparse file, i.e.,
* at least one of those records in the file is just
* a useless hole.
*/
#ifdef hpux /* Nice of HPUX to gratuitiously change it, huh? - mib */
if (hstat.st_size - (hstat.st_blocks * 1024) > 1024)
#else
if (hstat.st_size - (hstat.st_blocks * RECORDSIZE) > RECORDSIZE)
#endif
{
int filesize = hstat.st_size;
register int i;
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
header->header.linkflag = LF_SPARSE;
header_moved++;
/*
* Call the routine that figures out the
* layout of the sparse file in question.
* UPPERBOUND is the index of the last
* element of the "sparsearray," i.e.,
* the number of elements it needed to
* describe the file.
*/
upperbound = deal_with_sparse (p, header);
/*
* See if we'll need an extended header
* later
*/
if (upperbound > SPARSE_IN_HDR - 1)
header->header.isextended++;
/*
* We store the "real" file size so
* we can show that in case someone wants
* to list the archive, i.e., tar tvf <file>.
* It might be kind of disconcerting if the
* shrunken file size was the one that showed
* up.
*/
to_oct ((long) hstat.st_size, 1 + 12,
header->header.realsize);
/*
* This will be the new "size" of the
* file, i.e., the size of the file
* minus the records of holes that we're
* skipping over.
*/
find_new_file_size (&filesize, upperbound);
hstat.st_size = filesize;
to_oct ((long) filesize, 1 + 12,
header->header.size);
/* to_oct((long) end_nulls, 1+12,
header->header.ending_blanks);*/
for (i = 0; i < SPARSE_IN_HDR; i++)
{
if (!sparsearray[i].numbytes)
break;
to_oct (sparsearray[i].offset, 1 + 12,
header->header.sp[i].offset);
to_oct (sparsearray[i].numbytes, 1 + 12,
header->header.sp[i].numbytes);
}
}
}
#else
upperbound = SPARSE_IN_HDR - 1;
#endif
sizeleft = hstat.st_size;
/* Don't bother opening empty, world readable files. */
if (sizeleft > 0 || 0444 != (0444 & hstat.st_mode))
{
f = open (p, O_RDONLY | O_BINARY);
if (f < 0)
goto badperror;
}
else
{
f = -1;
}
/* If the file is sparse, we've already taken care of this */
if (!header_moved)
{
header = start_header (p, &hstat);
if (header == NULL)
{
if (f >= 0)
(void) close (f);
critical_error = 1;
goto badfile;
}
}
#ifdef S_ISCTG
/* Mark contiguous files, if we support them */
if (f_standard && S_ISCTG (hstat.st_mode))
{
header->header.linkflag = LF_CONTIG;
}
#endif
isextended = header->header.isextended;
save_linkflag = header->header.linkflag;
finish_header (header);
if (isextended)
{
/* int sum = 0;*/
register int i;
/* register union record *exhdr;*/
/* int arraybound = SPARSE_EXT_HDR;*/
/* static */ int index_offset = SPARSE_IN_HDR;
extend:exhdr = findrec ();
if (exhdr == NULL)
{
critical_error = 1;
goto badfile;
}
bzero (exhdr->charptr, RECORDSIZE);
for (i = 0; i < SPARSE_EXT_HDR; i++)
{
if (i + index_offset > upperbound)
break;
to_oct ((long) sparsearray[i + index_offset].numbytes,
1 + 12,
exhdr->ext_hdr.sp[i].numbytes);
to_oct ((long) sparsearray[i + index_offset].offset,
1 + 12,
exhdr->ext_hdr.sp[i].offset);
}
userec (exhdr);
/* sum += i;
if (sum < upperbound)
goto extend;*/
if (index_offset + i <= upperbound)
{
index_offset += i;
exhdr->ext_hdr.isextended++;
goto extend;
}
}
if (save_linkflag == LF_SPARSE)
{
if (finish_sparse_file (f, &sizeleft, (long) hstat.st_size, p))
goto padit;
}
else
while (sizeleft > 0)
{
if (f_multivol)
{
save_name = p;
save_sizeleft = sizeleft;
save_totsize = hstat.st_size;
}
start = findrec ();
bufsize = endofrecs ()->charptr - start->charptr;
if (sizeleft < bufsize)
{
/* Last read -- zero out area beyond */
bufsize = (int) sizeleft;
count = bufsize % RECORDSIZE;
if (count)
bzero (start->charptr + sizeleft,
(int) (RECORDSIZE - count));
}
count = read (f, start->charptr, bufsize);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading\
%d bytes, in file %s", (long) hstat.st_size - sizeleft, bufsize, p);
goto padit;
}
sizeleft -= count;
/* This is nonportable (the type of userec's arg). */
userec (start + (count - 1) / RECORDSIZE);
if (count == bufsize)
continue;
msg ("file %s shrunk by %d bytes, padding with zeros.", p, sizeleft);
goto padit; /* Short read */
}
if (f_multivol)
save_name = 0;
if (f >= 0)
(void) close (f);
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
if (f_atime_preserve)
utime (p, &restore_times);
return;
/*
* File shrunk or gave error, pad out tape to match
* the size we specified in the header.
*/
padit:
while (sizeleft > 0)
{
save_sizeleft = sizeleft;
start = findrec ();
bzero (start->charptr, RECORDSIZE);
userec (start);
sizeleft -= RECORDSIZE;
}
if (f_multivol)
save_name = 0;
if (f >= 0)
(void) close (f);
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
#ifdef S_ISLNK
else if (S_ISLNK (hstat.st_mode))
{
int size;
char *buf = alloca (PATH_MAX + 1);
size = readlink (p, buf, PATH_MAX + 1);
if (size < 0)
goto badperror;
buf[size] = '\0';
if (size >= NAMSIZ)
write_long (buf, LF_LONGLINK);
current_link_name = buf;
hstat.st_size = 0; /* Force 0 size on symlink */
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile;
}
strncpy (header->header.arch_linkname, buf, NAMSIZ);
header->header.arch_linkname[NAMSIZ - 1] = '\0';
header->header.linkflag = LF_SYMLINK;
finish_header (header); /* Nothing more to do to it */
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return;
}
#endif
else if (S_ISDIR (hstat.st_mode))
{
register DIR *dirp;
register struct dirent *d;
char *namebuf;
int buflen;
register int len;
int our_device = hstat.st_dev;
/* Build new prototype name */
len = strlen (p);
buflen = len + NAMSIZ;
namebuf = ck_malloc (buflen + 1);
strncpy (namebuf, p, buflen);
while (len >= 1 && '/' == namebuf[len - 1])
len--; /* Delete trailing slashes */
namebuf[len++] = '/'; /* Now add exactly one back */
namebuf[len] = '\0'; /* Make sure null-terminated */
/*
* Output directory header record with permissions
* FIXME, do this AFTER files, to avoid R/O dir problems?
* If old archive format, don't write record at all.
*/
if (!f_oldarch)
{
hstat.st_size = 0; /* Force 0 size on dir */
/*
* If people could really read standard archives,
* this should be: (FIXME)
header = start_header(f_standard? p: namebuf, &hstat);
* but since they'd interpret LF_DIR records as
* regular files, we'd better put the / on the name.
*/
header = start_header (namebuf, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile; /* eg name too long */
}
if (f_gnudump)
header->header.linkflag = LF_DUMPDIR;
else if (f_standard)
header->header.linkflag = LF_DIR;
/* If we're gnudumping, we aren't done yet so don't close it. */
if (!f_gnudump)
finish_header (header); /* Done with directory header */
}
if (f_gnudump)
{
int sizeleft;
int totsize;
int bufsize;
union record *start;
int count;
char *buf, *p_buf;
buf = gnu_list_name->dir_contents; /* FOO */
totsize = 0;
for (p_buf = buf; p_buf && *p_buf;)
{
int tmp;
tmp = strlen (p_buf) + 1;
totsize += tmp;
p_buf += tmp;
}
totsize++;
to_oct ((long) totsize, 1 + 12, header->header.size);
finish_header (header);
p_buf = buf;
sizeleft = totsize;
while (sizeleft > 0)
{
if (f_multivol)
{
save_name = p;
save_sizeleft = sizeleft;
save_totsize = totsize;
}
start = findrec ();
bufsize = endofrecs ()->charptr - start->charptr;
if (sizeleft < bufsize)
{
bufsize = sizeleft;
count = bufsize % RECORDSIZE;
if (count)
bzero (start->charptr + sizeleft, RECORDSIZE - count);
}
bcopy (p_buf, start->charptr, bufsize);
sizeleft -= bufsize;
p_buf += bufsize;
userec (start + (bufsize - 1) / RECORDSIZE);
}
if (f_multivol)
save_name = 0;
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
/* Now output all the files in the directory */
#if 0
if (f_dironly)
return; /* Unless the cmdline said not to */
#endif
/*
* See if we are crossing from one file system to another,
* and avoid doing so if the user only wants to dump one file system.
*/
if (f_local_filesys && !toplevel && curdev != hstat.st_dev)
{
if (f_verbose)
msg ("%s: is on a different filesystem; not dumped", p);
return;
}
errno = 0;
dirp = opendir (p);
if (!dirp)
{
if (errno)
{
msg_perror ("can't open directory %s", p);
}
else
{
msg ("error opening directory %s",
p);
}
return;
}
/* Hack to remove "./" from the front of all the file names */
if (len == 2 && namebuf[0] == '.' && namebuf[1] == '/')
len = 0;
/* Should speed this up by cd-ing into the dir, FIXME */
while (NULL != (d = readdir (dirp)))
{
/* Skip . and .. */
if (is_dot_or_dotdot (d->d_name))
continue;
if (NLENGTH (d) + len >= buflen)
{
buflen = len + NLENGTH (d);
namebuf = ck_realloc (namebuf, buflen + 1);
/* namebuf[len]='\0';
msg("file name %s%s too long",
namebuf, d->d_name);
continue; */
}
strcpy (namebuf + len, d->d_name);
if (f_exclude && check_exclude (namebuf))
continue;
dump_file (namebuf, our_device, 0);
}
closedir (dirp);
free (namebuf);
if (f_atime_preserve)
utime (p, &restore_times);
return;
}
#ifdef S_ISCHR
else if (S_ISCHR (hstat.st_mode))
{
type = LF_CHR;
}
#endif
#ifdef S_ISBLK
else if (S_ISBLK (hstat.st_mode))
{
type = LF_BLK;
}
#endif
/* Avoid screwy apollo lossage where S_IFIFO == S_IFSOCK */
#if (_ISP__M68K == 0) && (_ISP__A88K == 0) && defined(S_ISFIFO)
else if (S_ISFIFO (hstat.st_mode))
{
type = LF_FIFO;
}
#endif
#ifdef S_ISSOCK
else if (S_ISSOCK (hstat.st_mode))
{
type = LF_FIFO;
}
#endif
else
goto unknown;
if (!f_standard)
goto unknown;
hstat.st_size = 0; /* Force 0 size */
header = start_header (p, &hstat);
if (header == NULL)
{
critical_error = 1;
goto badfile; /* eg name too long */
}
header->header.linkflag = type;
#if defined(S_IFBLK) || defined(S_IFCHR)
if (type != LF_FIFO)
{
if (checked_to_oct ((long) major (hstat.st_rdev), 8,
header->header.devmajor))
{
msg ("%s: major number too large; not dumped", p);
critical_error = 1;
goto badfile;
}
if (checked_to_oct ((long) minor (hstat.st_rdev), 8,
header->header.devminor))
{
msg ("%s: minor number too large; not dumped", p);
critical_error = 1;
goto badfile;
}
}
#endif
finish_header (header);
if (f_remove_files)
{
if (unlink (p) == -1)
msg_perror ("cannot remove %s", p);
}
return;
unknown:
msg ("%s: Unknown file type; file ignored.", p);
}
int
finish_sparse_file (fd, sizeleft, fullsize, name)
int fd;
long *sizeleft, fullsize;
char *name;
{
union record *start;
char tempbuf[RECORDSIZE];
int bufsize, sparse_ind = 0, count;
long pos;
long nwritten = 0;
while (*sizeleft > 0)
{
start = findrec ();
bzero (start->charptr, RECORDSIZE);
bufsize = sparsearray[sparse_ind].numbytes;
if (!bufsize)
{ /* we blew it, maybe */
msg ("Wrote %ld of %ld bytes to file %s",
fullsize - *sizeleft, fullsize, name);
break;
}
pos = lseek (fd, sparsearray[sparse_ind++].offset, 0);
/*
* If the number of bytes to be written here exceeds
* the size of the temporary buffer, do it in steps.
*/
while (bufsize > RECORDSIZE)
{
/* if (amt_read) {
count = read(fd, start->charptr+amt_read, RECORDSIZE-amt_read);
bufsize -= RECORDSIZE - amt_read;
amt_read = 0;
userec(start);
start = findrec();
bzero(start->charptr, RECORDSIZE);
}*/
/* store the data */
count = read (fd, start->charptr, RECORDSIZE);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading %d bytes, in file %s",
fullsize - *sizeleft, bufsize, name);
return 1;
}
bufsize -= count;
*sizeleft -= count;
userec (start);
nwritten += RECORDSIZE; /* XXX */
start = findrec ();
bzero (start->charptr, RECORDSIZE);
}
clear_buffer (tempbuf);
count = read (fd, tempbuf, bufsize);
bcopy (tempbuf, start->charptr, RECORDSIZE);
if (count < 0)
{
msg_perror ("read error at byte %ld, reading %d bytes, in file %s",
fullsize - *sizeleft, bufsize, name);
return 1;
}
/* if (amt_read >= RECORDSIZE) {
amt_read = 0;
userec(start+(count-1)/RECORDSIZE);
if (count != bufsize) {
msg("file %s shrunk by %d bytes, padding with zeros.", name, sizeleft);
return 1;
}
start = findrec();
} else
amt_read += bufsize;*/
nwritten += count; /* XXX */
*sizeleft -= count;
userec (start);
}
free (sparsearray);
/* printf ("Amount actually written is (I hope) %d.\n", nwritten); */
/* userec(start+(count-1)/RECORDSIZE);*/
return 0;
}
void
init_sparsearray ()
{
register int i;
sp_array_size = 10;
/*
* Make room for our scratch space -- initially is 10 elts long
*/
sparsearray = (struct sp_array *) ck_malloc (sp_array_size * sizeof (struct sp_array));
for (i = 0; i < sp_array_size; i++)
{
sparsearray[i].offset = 0;
sparsearray[i].numbytes = 0;
}
}
/*
* Okay, we've got a sparse file on our hands -- now, what we need to do is
* make a pass through the file and carefully note where any data is, i.e.,
* we want to find how far into the file each instance of data is, and how
* many bytes are there. We store this information in the sparsearray,
* which will later be translated into header information. For now, we use
* the sparsearray as convenient storage.
*
* As a side note, this routine is a mess. If I could have found a cleaner
* way to do it, I would have. If anyone wants to find a nicer way to do
* this, feel free.
*/
/* There is little point in trimming small amounts of null data at the */
/* head and tail of blocks -- it's ok if we only avoid dumping blocks */
/* of complete null data */
int
deal_with_sparse (name, header, nulls_at_end)
char *name;
union record *header;
int nulls_at_end;
{
long numbytes = 0;
long offset = 0;
/* long save_offset;*/
int fd;
/* int current_size = hstat.st_size;*/
int sparse_ind = 0, cc;
char buf[RECORDSIZE];
#if 0
int read_last_data = 0; /* did we just read the last record? */
#endif
int amidst_data = 0;
header->header.isextended = 0;
/*
* Can't open the file -- this problem will be caught later on,
* so just return.
*/
if ((fd = open (name, O_RDONLY)) < 0)
return 0;
init_sparsearray ();
clear_buffer (buf);
while ((cc = read (fd, buf, sizeof buf)) != 0)
{
if (sparse_ind > sp_array_size - 1)
{
/*
* realloc the scratch area, since we've run out of room --
*/
sparsearray = (struct sp_array *)
ck_realloc (sparsearray,
2 * sp_array_size * (sizeof (struct sp_array)));
sp_array_size *= 2;
}
if (cc == sizeof buf)
{
if (zero_record (buf))
{
if (amidst_data)
{
sparsearray[sparse_ind++].numbytes
= numbytes;
amidst_data = 0;
}
}
else
{ /* !zero_record(buf) */
if (amidst_data)
numbytes += cc;
else
{
amidst_data = 1;
numbytes = cc;
sparsearray[sparse_ind].offset
= offset;
}
}
}
else if (cc < sizeof buf)
{
/* This has to be the last bit of the file, so this */
/* is somewhat shorter than the above. */
if (!zero_record (buf))
{
if (!amidst_data)
{
amidst_data = 1;
numbytes = cc;
sparsearray[sparse_ind].offset
= offset;
}
else
numbytes += cc;
}
}
offset += cc;
clear_buffer (buf);
}
if (amidst_data)
sparsearray[sparse_ind++].numbytes = numbytes;
else
{
sparsearray[sparse_ind].offset = offset-1;
sparsearray[sparse_ind++].numbytes = 1;
}
close (fd);
return sparse_ind - 1;
}
/*
* Just zeroes out the buffer so we don't confuse ourselves with leftover
* data.
*/
void
clear_buffer (buf)
char *buf;
{
register int i;
for (i = 0; i < RECORDSIZE; i++)
buf[i] = '\0';
}
#if 0 /* I'm leaving this as a monument to Joy Kendall, who wrote it -mib */
/*
* JK -
* This routine takes a character array, and tells where within that array
* the data can be found. It skips over any zeros, and sets the first
* non-zero point in the array to be the "start", and continues until it
* finds non-data again, which is marked as the "end." This routine is
* mainly for 1) seeing how far into a file we must lseek to data, given
* that we have a sparse file, and 2) determining the "real size" of the
* file, i.e., the number of bytes in the sparse file that are data, as
* opposed to the zeros we are trying to skip.
*/
where_is_data (from, to, buffer)
int *from, *to;
char *buffer;
{
register int i = 0;
register int save_to = *to;
int amidst_data = 0;
while (!buffer[i])
i++;
*from = i;
if (*from < 16) /* don't bother */
*from = 0;
/* keep going to make sure there isn't more real
data in this record */
while (i < RECORDSIZE)
{
if (!buffer[i])
{
if (amidst_data)
{
save_to = i;
amidst_data = 0;
}
i++;
}
else if (buffer[i])
{
if (!amidst_data)
amidst_data = 1;
i++;
}
}
if (i == RECORDSIZE)
*to = i;
else
*to = save_to;
}
#endif
/* Note that this routine is only called if zero_record returned true */
#if 0 /* But we actually don't need it at all. */
where_is_data (from, to, buffer)
int *from, *to;
char *buffer;
{
char *fp, *tp;
for (fp = buffer; !*fp; fp++)
;
for (tp = buffer + RECORDSIZE - 1; !*tp; tp--)
;
*from = fp - buffer;
*to = tp - buffer + 1;
}
#endif
/*
* Takes a recordful of data and basically cruises through it to see if
* it's made *entirely* of zeros, returning a 0 the instant it finds
* something that is a non-zero, i.e., useful data.
*/
int
zero_record (buffer)
char *buffer;
{
register int i;
for (i = 0; i < RECORDSIZE; i++)
if (buffer[i] != '\000')
return 0;
return 1;
}
void
find_new_file_size (filesize, highest_index)
int *filesize;
int highest_index;
{
register int i;
*filesize = 0;
for (i = 0; sparsearray[i].numbytes && i <= highest_index; i++)
*filesize += sparsearray[i].numbytes;
}
/*
* Make a header block for the file name whose stat info is st .
* Return header pointer for success, NULL if the name is too long.
*/
union record *
start_header (name, st)
char *name;
register struct stat *st;
{
register union record *header;
if (strlen (name) >= NAMSIZ)
write_long (name, LF_LONGNAME);
header = (union record *) findrec ();
bzero (header->charptr, sizeof (*header)); /* XXX speed up */
/*
* Check the file name and put it in the record.
*/
if (!f_absolute_paths)
{
static int warned_once = 0;
#ifdef __MSDOS__
if (name[1] == ':')
{
name += 2;
if (!warned_once++)
msg ("Removing drive spec from names in the archive");
}
#endif
while ('/' == *name)
{
name++; /* Force relative path */
if (!warned_once++)
msg ("Removing leading / from absolute path names in the archive.");
}
}
current_file_name = name;
strncpy (header->header.arch_name, name, NAMSIZ);
header->header.arch_name[NAMSIZ - 1] = '\0';
to_oct ((long) (f_oldarch ? (st->st_mode & 07777) : st->st_mode),
8, header->header.mode);
to_oct ((long) st->st_uid, 8, header->header.uid);
to_oct ((long) st->st_gid, 8, header->header.gid);
to_oct ((long) st->st_size, 1 + 12, header->header.size);
to_oct ((long) st->st_mtime, 1 + 12, header->header.mtime);
/* header->header.linkflag is left as null */
if (f_gnudump)
{
to_oct ((long) st->st_atime, 1 + 12, header->header.atime);
to_oct ((long) st->st_ctime, 1 + 12, header->header.ctime);
}
#ifndef NONAMES
/* Fill in new Unix Standard fields if desired. */
if (f_standard)
{
header->header.linkflag = LF_NORMAL; /* New default */
strcpy (header->header.magic, TMAGIC); /* Mark as Unix Std */
finduname (header->header.uname, st->st_uid);
findgname (header->header.gname, st->st_gid);
}
#endif
return header;
}
/*
* Finish off a filled-in header block and write it out.
* We also print the file name and/or full info if verbose is on.
*/
void
finish_header (header)
register union record *header;
{
register int i, sum;
register char *p;
bcopy (CHKBLANKS, header->header.chksum, sizeof (header->header.chksum));
sum = 0;
p = header->charptr;
for (i = sizeof (*header); --i >= 0;)
{
/*
* We can't use unsigned char here because of old compilers,
* e.g. V7.
*/
sum += 0xFF & *p++;
}
/*
* Fill in the checksum field. It's formatted differently
* from the other fields: it has [6] digits, a null, then a
* space -- rather than digits, a space, then a null.
* We use to_oct then write the null in over to_oct's space.
* The final space is already there, from checksumming, and
* to_oct doesn't modify it.
*
* This is a fast way to do:
* (void) sprintf(header->header.chksum, "%6o", sum);
*/
to_oct ((long) sum, 8, header->header.chksum);
header->header.chksum[6] = '\0'; /* Zap the space */
userec (header);
if (f_verbose)
{
extern union record *head;/* Points to current tape header */
extern int head_standard; /* Tape header is in ANSI format */
/* These globals are parameters to print_header, sigh */
head = header;
/* hstat is already set up */
head_standard = f_standard;
print_header ();
}
return;
}
/*
* Quick and dirty octal conversion.
* Converts long "value" into a "digs"-digit field at "where",
* including a trailing space and room for a null. "digs"==3 means
* 1 digit, a space, and room for a null.
*
* We assume the trailing null is already there and don't fill it in.
* This fact is used by start_header and finish_header, so don't change it!
*
* This should be equivalent to:
* (void) sprintf(where, "%*lo ", digs-2, value);
* except that sprintf fills in the trailing null and we don't.
*/
void
to_oct (value, digs, where)
register long value;
register int digs;
register char *where;
{
--digs; /* Trailing null slot is left alone */
where[--digs] = ' '; /* Put in the space, though */
/* Produce the digits -- at least one */
do
{
where[--digs] = '0' + (char) (value & 7); /* one octal digit */
value >>= 3;
}
while (digs > 0 && value != 0);
/* Leading spaces, if necessary */
while (digs > 0)
where[--digs] = ' ';
}
/*
* Call to_oct (), then return nonzero iff the conversion failed.
*/
int
checked_to_oct (value, digs, where)
register long value;
register int digs;
register char *where;
{
long from_oct ();
to_oct (value, digs, where);
return from_oct (digs, where) != value;
}
/*
* Write the EOT record(s).
* We actually zero at least one record, through the end of the block.
* Old tar writes garbage after two zeroed records -- and PDtar used to.
*/
void
write_eot ()
{
union record *p;
int bufsize;
p = findrec ();
if (p)
{
bufsize = endofrecs ()->charptr - p->charptr;
bzero (p->charptr, bufsize);
userec (p);
}
}
/* Write a LF_LONGLINK or LF_LONGNAME record. */
void
write_long (p, type)
char *p;
char type;
{
int size = strlen (p) + 1;
int bufsize;
union record *header;
struct stat foo;
bzero (&foo, sizeof foo);
foo.st_size = size;
header = start_header ("././@LongLink", &foo);
header->header.linkflag = type;
finish_header (header);
header = findrec ();
bufsize = endofrecs ()->charptr - header->charptr;
while (bufsize < size)
{
bcopy (p, header->charptr, bufsize);
p += bufsize;
size -= bufsize;
userec (header + (bufsize - 1) / RECORDSIZE);
header = findrec ();
bufsize = endofrecs ()->charptr - header->charptr;
}
bcopy (p, header->charptr, size);
bzero (header->charptr + size, bufsize - size);
userec (header + (size - 1) / RECORDSIZE);
}
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