freebsd-dev/gnu/libexec/uucp/libunix/filnam.c
1995-08-19 21:30:30 +00:00

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/* filnam.c
Get names to use for UUCP files.
Copyright (C) 1991, 1992, 1993, 1995 Ian Lance Taylor
This file is part of the Taylor UUCP package.
This program 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 of the
License, or (at your option) any later version.
This program 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 this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
The author of the program may be contacted at ian@airs.com or
c/o Cygnus Support, 48 Grove Street, Somerville, MA 02144.
*/
#include "uucp.h"
#include "uudefs.h"
#include "uuconf.h"
#include "sysdep.h"
#include "system.h"
#include <errno.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#else
#if HAVE_SYS_FILE_H
#include <sys/file.h>
#endif
#endif
#ifndef O_RDONLY
#define O_RDONLY 0
#define O_WRONLY 1
#define O_RDWR 2
#endif
#ifndef O_NOCTTY
#define O_NOCTTY 0
#endif
/* We need a definition for SEEK_SET. */
#ifndef SEEK_SET
#define SEEK_SET 0
#endif
/* We use POSIX style fcntl locks if they are available, unless
O_CREAT is not defined. We could use them in the latter case, but
the code would have to become more complex to avoid races
concerning the use of creat. It is very unlikely that there is any
system which does have POSIX style locking but does not have
O_CREAT. */
#if ! HAVE_BROKEN_SETLKW
#ifdef F_SETLKW
#ifdef O_CREAT
#define USE_POSIX_LOCKS 1
#endif
#endif
#endif
#ifndef USE_POSIX_LOCKS
#define USE_POSIX_LOCKS 0
#endif
/* External functions. */
#ifndef lseek
extern off_t lseek ();
#endif
#define ZCHARS \
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
/* Local functions. */
static boolean fscmd_seq P((const char *zsystem, char *zseq));
static char *zsfile_name P((int btype, const char *zsystem,
const char *zlocalname, int bgrade,
boolean fxqt, char *ztname, char *zdname,
char *zxname));
/* Get a new command sequence number (this is not a sequence number to
be used for communicating with another system, but a sequence
number to be used when generating the name of a command file).
The sequence number is placed into zseq, which should be five
characters long. */
static boolean
fscmd_seq (zsystem, zseq)
const char *zsystem;
char *zseq;
{
int cdelay;
char *zfree;
const char *zfile;
int o;
boolean flockfile;
int i;
boolean fret;
cdelay = 5;
#if ! USE_POSIX_LOCKS
{
boolean ferr;
/* Lock the sequence file. */
while (! fsdo_lock ("LCK..SEQ", TRUE, &ferr))
{
if (ferr || FGOT_SIGNAL ())
return FALSE;
sleep (cdelay);
if (cdelay < 60)
++cdelay;
}
}
#endif
zfree = NULL;
#if SPOOLDIR_V2 || SPOOLDIR_BSD42 || SPOOLDIR_BSD43
zfile = "SEQF";
#endif
#if SPOOLDIR_HDB || SPOOLDIR_SVR4
zfree = zsysdep_in_dir (".Sequence", zsystem);
zfile = zfree;
#endif
#if SPOOLDIR_ULTRIX
if (! fsultrix_has_spool (zsystem))
zfile = "sys/DEFAULT/.SEQF";
else
{
zfree = zsappend3 ("sys", zsystem, ".SEQF");
zfile = zfree;
}
#endif /* SPOOLDIR_ULTRIX */
#if SPOOLDIR_TAYLOR
zfree = zsysdep_in_dir (zsystem, "SEQF");
zfile = zfree;
#endif /* SPOOLDIR_TAYLOR */
#ifdef O_CREAT
o = open ((char *) zfile, O_RDWR | O_CREAT | O_NOCTTY, IPRIVATE_FILE_MODE);
#else
o = open ((char *) zfile, O_RDWR | O_NOCTTY);
if (o < 0 && errno == ENOENT)
{
o = creat ((char *) zfile, IPRIVATE_FILE_MODE);
if (o >= 0)
{
(void) close (o);
o = open ((char *) zfile, O_RDWR | O_NOCTTY);
}
}
#endif
if (o < 0)
{
if (errno == ENOENT)
{
if (! fsysdep_make_dirs (zfile, FALSE))
{
#if ! USE_POSIX_LOCKS
(void) fsdo_unlock ("LCK..SEQ", TRUE);
#endif
return FALSE;
}
#ifdef O_CREAT
o = open ((char *) zfile,
O_RDWR | O_CREAT | O_NOCTTY,
IPRIVATE_FILE_MODE);
#else
o = creat ((char *) zfile, IPRIVATE_FILE_MODE);
if (o >= 0)
{
(void) close (o);
o = open ((char *) zfile, O_RDWR | O_NOCTTY);
}
#endif
}
if (o < 0)
{
ulog (LOG_ERROR, "open (%s): %s", zfile, strerror (errno));
#if ! USE_POSIX_LOCKS
(void) fsdo_unlock ("LCK..SEQ", TRUE);
#endif
return FALSE;
}
}
#if ! USE_POSIX_LOCKS
flockfile = TRUE;
#else
{
struct flock slock;
flockfile = FALSE;
slock.l_type = F_WRLCK;
slock.l_whence = SEEK_SET;
slock.l_start = 0;
slock.l_len = 0;
while (fcntl (o, F_SETLKW, &slock) == -1)
{
boolean fagain;
/* Some systems define F_SETLKW, but it does not work. We try
to catch those systems at runtime, and revert to using a
lock file. */
if (errno == EINVAL)
{
boolean ferr;
/* Lock the sequence file. */
while (! fsdo_lock ("LCK..SEQ", TRUE, &ferr))
{
if (ferr || FGOT_SIGNAL ())
{
(void) close (o);
return FALSE;
}
sleep (cdelay);
if (cdelay < 60)
++cdelay;
}
flockfile = TRUE;
break;
}
fagain = FALSE;
if (errno == ENOMEM)
fagain = TRUE;
#ifdef ENOLCK
if (errno == ENOLCK)
fagain = TRUE;
#endif
#ifdef ENOSPC
if (errno == ENOSPC)
fagain = TRUE;
#endif
if (fagain)
{
sleep (cdelay);
if (cdelay < 60)
++cdelay;
continue;
}
ulog (LOG_ERROR, "Locking %s: %s", zfile, strerror (errno));
(void) close (o);
return FALSE;
}
}
#endif
if (read (o, zseq, CSEQLEN) != CSEQLEN)
strcpy (zseq, "0000");
zseq[CSEQLEN] = '\0';
/* We must add one to the sequence number and return the new value.
On Ultrix, arbitrary characters are allowed in the sequence
number. On other systems, the sequence number apparently must be
in hex. */
#if SPOOLDIR_V2 || SPOOLDIR_BSD42 || SPOOLDIR_BSD43 || SPOOLDIR_HDB || SPOOLDIR_SVR4
i = (int) strtol (zseq, (char **) NULL, 16);
++i;
if (i > 0xffff)
i = 0;
/* The sprintf argument has CSEQLEN built into it. */
sprintf (zseq, "%04x", (unsigned int) i);
#endif
#if SPOOLDIR_ULTRIX || SPOOLDIR_TAYLOR
for (i = CSEQLEN - 1; i >= 0; i--)
{
const char *zdig;
zdig = strchr (ZCHARS, zseq[i]);
if (zdig == NULL || zdig[0] == '\0' || zdig[1] == '\0')
zseq[i] = '0';
else
{
zseq[i] = zdig[1];
break;
}
}
#endif /* SPOOLDIR_ULTRIX || SPOOLDIR_TAYLOR */
fret = TRUE;
if (lseek (o, (off_t) 0, SEEK_SET) < 0
|| write (o, zseq, CSEQLEN) != CSEQLEN
|| close (o) < 0)
{
ulog (LOG_ERROR, "lseek or write or close %s: %s",
zfile, strerror (errno));
(void) close (o);
fret = FALSE;
}
if (flockfile)
(void) fsdo_unlock ("LCK..SEQ", TRUE);
ubuffree (zfree);
return fret;
}
/* Get the name of a command or data file for a remote system. The
btype argument should be C for a command file or D for a data file.
If the grade of a data file is X, it is assumed that this is going
to become an execute file on some other system. The zsystem
argument is the system that the file will be transferred to. The
ztname argument will be set to a file name that could be passed to
zsysdep_spool_file_name. The zdname argument, if not NULL, will be
set to a data file name appropriate for the remote system. The
zxname argument, if not NULL, will be set to the name of an execute
file on the remote system. None of the names will be more than 14
characters long. */
/*ARGSUSED*/
static char *
zsfile_name (btype, zsystem, zlocalname, bgrade, fxqt, ztname, zdname, zxname)
int btype;
const char *zsystem;
const char *zlocalname;
int bgrade;
boolean fxqt;
char *ztname;
char *zdname;
char *zxname;
{
char abseq[CSEQLEN + 1];
char absimple[11 + CSEQLEN];
char *zname;
if (zlocalname == NULL)
zlocalname = zSlocalname;
while (TRUE)
{
if (! fscmd_seq (zsystem, abseq))
return NULL;
if (btype == 'C')
{
#if ! SPOOLDIR_TAYLOR
sprintf (absimple, "C.%.7s%c%s", zsystem, bgrade, abseq);
#else
sprintf (absimple, "C.%c%s", bgrade, abseq);
#endif
}
else if (btype == 'D')
{
/* This name doesn't really matter that much; it's just the
name we use on the local system. The name we use on the
remote system, which we return in zdname, should contain
our system name so that remote UUCP's running SPOOLDIR_V2
and the like can distinguish while files come from which
systems. */
#if SPOOLDIR_SVR4
sprintf (absimple, "D.%.7s%c%s", zsystem, bgrade, abseq);
#else /* ! SPOOLDIR_SVR4 */
#if ! SPOOLDIR_TAYLOR
sprintf (absimple, "D.%.7s%c%s", zlocalname, bgrade, abseq);
#else /* SPOOLDIR_TAYLOR */
if (fxqt)
sprintf (absimple, "D.X%s", abseq);
else
sprintf (absimple, "D.%s", abseq);
#endif /* SPOOLDIR_TAYLOR */
#endif /* ! SPOOLDIR_HDB && ! SPOOLDIR_SVR4 */
}
#if DEBUG > 0
else
ulog (LOG_FATAL, "zsfile_name: Can't happen");
#endif
zname = zsfind_file (absimple, zsystem, bgrade);
if (zname == NULL)
return NULL;
if (! fsysdep_file_exists (zname))
break;
ubuffree (zname);
}
if (ztname != NULL)
strcpy (ztname, absimple);
if (zdname != NULL)
sprintf (zdname, "D.%.7s%c%s", zlocalname, bgrade, abseq);
if (zxname != NULL)
sprintf (zxname, "X.%.7s%c%s", zlocalname, bgrade, abseq);
return zname;
}
/* Return a name to use for a data file to be copied to another
system. The name returned will be for a real file. The zlocalname
argument is the local name as seen by the remote system, the bgrade
argument is the file grade, and the fxqt argument is TRUE if this
file will become an execution file. The ztname argument, if not
NULL, will be set to a name that could be passed to
zsysdep_spool_file_name to get back the return value of this
function. The zdname argument, if not NULL, will be set to a name
that the file could be given on another system. The zxname
argument, if not NULL, will be set to a name for an execute file on
another system. */
char *
zsysdep_data_file_name (qsys, zlocalname, bgrade, fxqt, ztname, zdname,
zxname)
const struct uuconf_system *qsys;
const char *zlocalname;
int bgrade;
boolean fxqt;
char *ztname;
char *zdname;
char *zxname;
{
return zsfile_name ('D', qsys->uuconf_zname, zlocalname, bgrade, fxqt,
ztname, zdname, zxname);
}
#if SPOOLDIR_TAYLOR
/* Write out a number in base 62 into a given number of characters,
right justified with zero fill. This is used by zscmd_file if
SPOOLDIR_TAYLOR. */
static void usput62 P((long i, char *, int c));
static void
usput62 (i, z, c)
long i;
char *z;
int c;
{
for (--c; c >= 0; --c)
{
int d;
d = i % 62;
i /= 62;
if (d < 26)
z[c] = 'A' + d;
else if (d < 52)
z[c] = 'a' + d - 26;
else
z[c] = '0' + d - 52;
}
}
#endif /* SPOOLDIR_TAYLOR */
/* Get a command file name. */
char *
zscmd_file (qsys, bgrade)
const struct uuconf_system *qsys;
int bgrade;
{
#if ! SPOOLDIR_TAYLOR
return zsfile_name ('C', qsys->uuconf_zname, (const char *) NULL,
bgrade, FALSE, (char *) NULL, (char *) NULL,
(char *) NULL);
#else
char *zname;
long isecs, imicros;
pid_t ipid;
/* This file name is never seen by the remote system, so we don't
actually need to get a sequence number for it. We just need to
get a file name which is unique for this system. We don't try
this optimization for other spool directory formats, mainly due
to compatibility concerns. It would be possible for HDB and SVR4
spool directory formats.
We get a unique name by combining the process ID and the current
time. The file name must start with C.g, where g is the grade.
Note that although it is likely that this name will be unique, it
is not guaranteed, so the caller must be careful. */
isecs = ixsysdep_time (&imicros);
ipid = getpid ();
/* We are going to represent the file name as a series of numbers in
base 62 (using the alphanumeric characters). The maximum file
name length is 14 characters, so we may use 11. We use 3 for the
seconds within the day, 3 for the microseconds, and 5 for the
process ID. */
/* Cut the seconds down to a number within a day (maximum value
86399 < 62 ** 3 == 238328). */
isecs %= (long) 24 * (long) 60 * (long) 60;
/* Divide the microseconds (max 999999) by 5 to make sure they are
less than 62 ** 3. */
imicros %= 1000000;
imicros /= 5;
while (TRUE)
{
char ab[15];
ab[0] = 'C';
ab[1] = '.';
ab[2] = bgrade;
usput62 (isecs, ab + 3, 3);
usput62 (imicros, ab + 6, 3);
usput62 ((long) ipid, ab + 9, 5);
ab[14] = '\0';
zname = zsfind_file (ab, qsys->uuconf_zname, bgrade);
if (zname == NULL)
return NULL;
if (! fsysdep_file_exists (zname))
break;
ubuffree (zname);
/* We hit a duplicate. Move backward in time until we find an
available name. Note that there is still a theoretical race
condition, since 5 base 62 digits might not be enough for the
process ID, and some other process might be running these
checks at the same time as we are. The caller must deal with
this. */
if (imicros == 0)
{
imicros = (long) 62 * (long) 62 * (long) 62;
if (isecs == 0)
isecs = (long) 62 * (long) 62 * (long) 62;
--isecs;
}
--imicros;
}
return zname;
#endif
}
/* Return a name for an execute file to be created locally. This is
used by uux to execute a command locally with remote files. */
char *
zsysdep_xqt_file_name ()
{
char abseq[CSEQLEN + 1];
char absx[11 + CSEQLEN];
char *zname;
while (TRUE)
{
if (! fscmd_seq (zSlocalname, abseq))
return NULL;
sprintf (absx, "X.%.7sX%s", zSlocalname, abseq);
zname = zsfind_file (absx, zSlocalname, -1);
if (zname == NULL)
return NULL;
if (! fsysdep_file_exists (zname))
break;
ubuffree (zname);
}
return zname;
}