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NetBSD/usr.sbin/sendmail/mail.local/mail.local.c
perry 3fe138c146 RCS Id Police.
1998-01-09 08:03:16 +00:00

948 lines
22 KiB
C
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/* $NetBSD: mail.local.c,v 1.3 1998/01/09 08:10:39 perry Exp $ */
/*-
* Copyright (c) 1990, 1993, 1994
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1990, 1993, 1994\n\
The Regents of the University of California. All rights reserved.\n";
#endif /* not lint */
#ifndef lint
static char sccsid[] = "@(#)mail.local.c 8.43 (Berkeley) 8/2/97";
#endif /* not lint */
/*
* This is not intended to compile on System V derived systems
* such as Solaris or HP-UX, since they use a totally different
* approach to mailboxes (essentially, they have a setgid program
* rather than setuid, and they rely on the ability to "give away"
* files to do their work). IT IS NOT A BUG that this doesn't
* compile on such architectures.
*/
#include <sys/param.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <time.h>
#include <unistd.h>
#ifdef EX_OK
# undef EX_OK /* unistd.h may have another use for this */
#endif
#include <sysexits.h>
#include <ctype.h>
#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif
#if (defined(sun) && defined(__svr4__)) || defined(__SVR4)
# define USE_LOCKF 1
# define USE_SETEUID 1
# define _PATH_MAILDIR "/var/mail"
#endif
#if defined(_AIX)
# define USE_LOCKF 1
# define USET_SETEUID 1
# define USE_VSYSLOG 0
#endif
#if defined(ultrix)
# define USE_VSYSLOG 0
#endif
#if defined(__osf__)
# define USE_VSYSLOG 0
#endif
#if defined(NeXT)
# include <libc.h>
# define _PATH_MAILDIR "/usr/spool/mail"
# define __dead /* empty */
# define S_IRUSR S_IREAD
# define S_IWUSR S_IWRITE
#endif
/*
* If you don't have flock, you could try using lockf instead.
*/
#ifdef USE_LOCKF
# define flock(a, b) lockf(a, b, 0)
# define LOCK_EX F_LOCK
#endif
#ifndef USE_VSYSLOG
# define USE_VSYSLOG 1
#endif
#ifndef LOCK_EX
# include <sys/file.h>
#endif
#ifdef BSD4_4
# include "pathnames.h"
#endif
#ifndef __P
# ifdef __STDC__
# define __P(protos) protos
# else
# define __P(protos) ()
# define const
# endif
#endif
#ifndef __dead
# if defined(__GNUC__) && (__GNUC__ < 2 || __GNUC_MINOR__ < 5) && !defined(__STRICT_ANSI__)
# define __dead __volatile
# else
# define __dead
# endif
#endif
#ifdef BSD4_4
# define HAS_ST_GEN 1
#else
# define _BSD_VA_LIST_ va_list
#endif
#if defined(BSD4_4) || defined(linux)
# define HASSNPRINTF 1
#else
extern char *strerror __P((int));
extern int snprintf __P((char *, size_t, const char *, ...));
extern FILE *fdopen __P((int, const char *));
#endif
#if SOLARIS >= 20600 || (SOLARIS < 10000 && SOLARIS >= 206)
# define HASSNPRINTF 1 /* has snprintf starting in 2.6 */
#endif
/*
* If you don't have setreuid, and you have saved uids, and you have
* a seteuid() call that doesn't try to emulate using setuid(), then
* you can try defining USE_SETEUID.
*/
#ifdef USE_SETEUID
# define setreuid(r, e) seteuid(e)
#endif
#ifndef _PATH_LOCTMP
# define _PATH_LOCTMP "/tmp/local.XXXXXX"
#endif
#ifndef _PATH_MAILDIR
# define _PATH_MAILDIR "/var/spool/mail"
#endif
#ifndef S_ISREG
# define S_ISREG(mode) (((mode) & _S_IFMT) == S_IFREG)
#endif
int eval = EX_OK; /* sysexits.h error value. */
void deliver __P((int, char *));
void e_to_sys __P((int));
__dead void err __P((const char *, ...));
void notifybiff __P((char *));
int store __P((char *));
void usage __P((void));
void vwarn __P((const char *, _BSD_VA_LIST_));
void warn __P((const char *, ...));
void lockmbox __P((char *));
void unlockmbox __P((void));
int
main(argc, argv)
int argc;
char *argv[];
{
struct passwd *pw;
int ch, fd;
uid_t uid;
char *from;
extern char *optarg;
extern int optind;
/* make sure we have some open file descriptors */
for (fd = 10; fd < 30; fd++)
(void) close(fd);
/* use a reasonable umask */
(void) umask(0077);
#ifdef LOG_MAIL
openlog("mail.local", 0, LOG_MAIL);
#else
openlog("mail.local", 0);
#endif
from = NULL;
while ((ch = getopt(argc, argv, "df:r:")) != -1)
switch(ch) {
case 'd': /* Backward compatible. */
break;
case 'f':
case 'r': /* Backward compatible. */
if (from != NULL) {
warn("multiple -f options");
usage();
}
from = optarg;
break;
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (!*argv)
usage();
/*
* If from not specified, use the name from getlogin() if the
* uid matches, otherwise, use the name from the password file
* corresponding to the uid.
*/
uid = getuid();
if (!from && (!(from = getlogin()) ||
!(pw = getpwnam(from)) || pw->pw_uid != uid))
from = (pw = getpwuid(uid)) ? pw->pw_name : "???";
/*
* There is no way to distinguish the error status of one delivery
* from the rest of the deliveries. So, if we failed hard on one
* or more deliveries, but had no failures on any of the others, we
* return a hard failure. If we failed temporarily on one or more
* deliveries, we return a temporary failure regardless of the other
* failures. This results in the delivery being reattempted later
* at the expense of repeated failures and multiple deliveries.
*/
for (fd = store(from); *argv; ++argv)
deliver(fd, *argv);
exit(eval);
}
int
store(from)
char *from;
{
FILE *fp;
time_t tval;
int fd, eline;
char line[2048];
char tmpbuf[sizeof _PATH_LOCTMP + 1];
strcpy(tmpbuf, _PATH_LOCTMP);
if ((fd = mkstemp(tmpbuf)) == -1 || (fp = fdopen(fd, "w+")) == NULL) {
e_to_sys(errno);
err("unable to open temporary file");
}
(void)unlink(tmpbuf);
(void)time(&tval);
(void)fprintf(fp, "From %s %s", from, ctime(&tval));
line[0] = '\0';
for (eline = 1; fgets(line, sizeof(line), stdin);) {
if (line[0] == '\n')
eline = 1;
else {
if (eline && line[0] == 'F' &&
!memcmp(line, "From ", 5))
(void)putc('>', fp);
eline = 0;
}
(void)fprintf(fp, "%s", line);
if (ferror(fp)) {
e_to_sys(errno);
err("temporary file write error");
}
}
/* If message not newline terminated, need an extra. */
if (!strchr(line, '\n'))
(void)putc('\n', fp);
/* Output a newline; note, empty messages are allowed. */
(void)putc('\n', fp);
if (fflush(fp) == EOF || ferror(fp)) {
e_to_sys(errno);
err("temporary file write error");
}
return (fd);
}
void
deliver(fd, name)
int fd;
char *name;
{
struct stat fsb, sb;
struct passwd *pw;
int mbfd, nr, nw, off;
char *p;
char biffmsg[100], buf[8*1024], path[MAXPATHLEN];
off_t curoff;
/*
* Disallow delivery to unknown names -- special mailboxes can be
* handled in the sendmail aliases file.
*/
if (!(pw = getpwnam(name))) {
if (eval != EX_TEMPFAIL)
eval = EX_UNAVAILABLE;
warn("unknown name: %s", name);
return;
}
endpwent();
/*
* Keep name reasonably short to avoid buffer overruns.
* This isn't necessary on BSD because of the proper
* definition of snprintf(), but it can cause problems
* on other systems.
* Also, clear out any bogus characters.
*/
if (strlen(name) > 40)
name[40] = '\0';
for (p = name; *p != '\0'; p++)
{
if (!isascii(*p))
*p &= 0x7f;
else if (!isprint(*p))
*p = '.';
}
(void)snprintf(path, sizeof(path), "%s/%s", _PATH_MAILDIR, name);
/*
* If the mailbox is linked or a symlink, fail. There's an obvious
* race here, that the file was replaced with a symbolic link after
* the lstat returned, but before the open. We attempt to detect
* this by comparing the original stat information and information
* returned by an fstat of the file descriptor returned by the open.
*
* NB: this is a symptom of a larger problem, that the mail spooling
* directory is writeable by the wrong users. If that directory is
* writeable, system security is compromised for other reasons, and
* it cannot be fixed here.
*
* If we created the mailbox, set the owner/group. If that fails,
* just return. Another process may have already opened it, so we
* can't unlink it. Historically, binmail set the owner/group at
* each mail delivery. We no longer do this, assuming that if the
* ownership or permissions were changed there was a reason.
*
* XXX
* open(2) should support flock'ing the file.
*/
tryagain:
lockmbox(path);
if (lstat(path, &sb) < 0) {
mbfd = open(path,
O_APPEND|O_CREAT|O_EXCL|O_WRONLY, S_IRUSR|S_IWUSR);
if (lstat(path, &sb) < 0)
{
eval = EX_CANTCREAT;
warn("%s: lstat: file changed after open", path);
goto err1;
}
else
sb.st_uid = pw->pw_uid;
if (mbfd == -1) {
if (errno == EEXIST)
goto tryagain;
} else if (fchown(mbfd, pw->pw_uid, pw->pw_gid)) {
e_to_sys(errno);
warn("chown %u.%u: %s", pw->pw_uid, pw->pw_gid, name);
goto err1;
}
} else if (sb.st_nlink != 1 || !S_ISREG(sb.st_mode)) {
e_to_sys(errno);
warn("%s: irregular file", path);
goto err0;
} else if (sb.st_uid != pw->pw_uid) {
eval = EX_CANTCREAT;
warn("%s: wrong ownership (%d)", path, sb.st_uid);
goto err0;
} else {
mbfd = open(path, O_APPEND|O_WRONLY, 0);
}
if (mbfd == -1) {
e_to_sys(errno);
warn("%s: %s", path, strerror(errno));
goto err0;
} else if (fstat(mbfd, &fsb) < 0 ||
fsb.st_nlink != 1 ||
sb.st_nlink != 1 ||
!S_ISREG(fsb.st_mode) ||
sb.st_dev != fsb.st_dev ||
sb.st_ino != fsb.st_ino ||
#if HAS_ST_GEN && 0 /* AFS returns random values for st_gen */
sb.st_gen != fsb.st_gen ||
#endif
sb.st_uid != fsb.st_uid) {
eval = EX_TEMPFAIL;
warn("%s: fstat: file changed after open", path);
goto err1;
}
/* Wait until we can get a lock on the file. */
if (flock(mbfd, LOCK_EX)) {
e_to_sys(errno);
warn("%s: %s", path, strerror(errno));
goto err1;
}
/* Get the starting offset of the new message for biff. */
curoff = lseek(mbfd, (off_t)0, SEEK_END);
(void)snprintf(biffmsg, sizeof(biffmsg),
sizeof curoff > sizeof(long) ? "%s@%qd\n" : "%s@%ld\n",
name, curoff);
/* Copy the message into the file. */
if (lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) {
e_to_sys(errno);
warn("temporary file: %s", strerror(errno));
goto err1;
}
if (setreuid(0, pw->pw_uid) < 0) {
e_to_sys(errno);
warn("setreuid(0, %d): %s (r=%d, e=%d)",
pw->pw_uid, strerror(errno), getuid(), geteuid());
goto err1;
}
#ifdef DEBUG
printf("new euid = %d\n", geteuid());
#endif
while ((nr = read(fd, buf, sizeof(buf))) > 0)
for (off = 0; off < nr; off += nw)
if ((nw = write(mbfd, buf + off, nr - off)) < 0) {
e_to_sys(errno);
warn("%s: %s", path, strerror(errno));
goto err3;
}
if (nr < 0) {
e_to_sys(errno);
warn("temporary file: %s", strerror(errno));
goto err3;
}
/* Flush to disk, don't wait for update. */
if (fsync(mbfd)) {
e_to_sys(errno);
warn("%s: %s", path, strerror(errno));
err3:
if (setreuid(0, 0) < 0) {
e_to_sys(errno);
warn("setreuid(0, 0): %s", strerror(errno));
}
#ifdef DEBUG
printf("reset euid = %d\n", geteuid());
#endif
err2: (void)ftruncate(mbfd, curoff);
err1: (void)close(mbfd);
err0: unlockmbox();
return;
}
/* Close and check -- NFS doesn't write until the close. */
if (close(mbfd)) {
e_to_sys(errno);
warn("%s: %s", path, strerror(errno));
truncate(path, curoff);
} else
notifybiff(biffmsg);
if (setreuid(0, 0) < 0) {
e_to_sys(errno);
warn("setreuid(0, 0): %s", strerror(errno));
}
#ifdef DEBUG
printf("reset euid = %d\n", geteuid());
#endif
unlockmbox();
}
/*
* user.lock files are necessary for compatibility with other
* systems, e.g., when the mail spool file is NFS exported.
* Alas, mailbox locking is more than just a local matter.
* EPA 11/94.
*/
char lockname[MAXPATHLEN];
int locked = 0;
void
lockmbox(path)
char *path;
{
int statfailed = 0;
if (locked)
return;
if (strlen(path) + 6 > sizeof lockname)
return;
sprintf(lockname, "%s.lock", path);
for (;; sleep(5)) {
int fd;
struct stat st;
time_t now;
fd = open(lockname, O_WRONLY|O_EXCL|O_CREAT, 0);
if (fd >= 0) {
locked = 1;
close(fd);
return;
}
if (stat(lockname, &st) < 0) {
if (statfailed++ > 5)
return;
continue;
}
statfailed = 0;
time(&now);
if (now < st.st_ctime + 300)
continue;
unlink(lockname);
}
}
void
unlockmbox()
{
if (!locked)
return;
unlink(lockname);
locked = 0;
}
void
notifybiff(msg)
char *msg;
{
static struct sockaddr_in addr;
static int f = -1;
struct hostent *hp;
struct servent *sp;
int len;
if (!addr.sin_family) {
/* Be silent if biff service not available. */
if (!(sp = getservbyname("biff", "udp")))
return;
if (!(hp = gethostbyname("localhost"))) {
warn("localhost: %s", strerror(errno));
return;
}
addr.sin_family = hp->h_addrtype;
memcpy(&addr.sin_addr, hp->h_addr, hp->h_length);
addr.sin_port = sp->s_port;
}
if (f < 0 && (f = socket(AF_INET, SOCK_DGRAM, 0)) == -1) {
warn("socket: %s", strerror(errno));
return;
}
len = strlen(msg) + 1;
if (sendto(f, msg, len, 0, (struct sockaddr *)&addr, sizeof(addr))
!= len)
warn("sendto biff: %s", strerror(errno));
}
void
usage()
{
eval = EX_USAGE;
err("usage: mail.local [-f from] user ...");
}
#if __STDC__
void
err(const char *fmt, ...)
#else
void
err(fmt, va_alist)
const char *fmt;
va_dcl
#endif
{
va_list ap;
#if __STDC__
va_start(ap, fmt);
#else
va_start(ap);
#endif
vwarn(fmt, ap);
va_end(ap);
exit(eval);
}
void
#if __STDC__
warn(const char *fmt, ...)
#else
warn(fmt, va_alist)
const char *fmt;
va_dcl
#endif
{
va_list ap;
#if __STDC__
va_start(ap, fmt);
#else
va_start(ap);
#endif
vwarn(fmt, ap);
va_end(ap);
}
void
vwarn(fmt, ap)
const char *fmt;
_BSD_VA_LIST_ ap;
{
/*
* Log the message to stderr.
*
* Don't use LOG_PERROR as an openlog() flag to do this,
* it's not portable enough.
*/
if (eval != EX_USAGE)
(void)fprintf(stderr, "mail.local: ");
(void)vfprintf(stderr, fmt, ap);
(void)fprintf(stderr, "\n");
#if USE_VSYSLOG
/* Log the message to syslog. */
vsyslog(LOG_ERR, fmt, ap);
#else
{
char fmtbuf[10240];
(void) vsprintf(fmtbuf, fmt, ap);
syslog(LOG_ERR, "%s", fmtbuf);
}
#endif
}
/*
* e_to_sys --
* Guess which errno's are temporary. Gag me.
*/
void
e_to_sys(num)
int num;
{
/* Temporary failures override hard errors. */
if (eval == EX_TEMPFAIL)
return;
switch(num) { /* Hopefully temporary errors. */
#ifdef EAGAIN
case EAGAIN: /* Resource temporarily unavailable */
#endif
#ifdef EDQUOT
case EDQUOT: /* Disc quota exceeded */
#endif
#ifdef EBUSY
case EBUSY: /* Device busy */
#endif
#ifdef EPROCLIM
case EPROCLIM: /* Too many processes */
#endif
#ifdef EUSERS
case EUSERS: /* Too many users */
#endif
#ifdef ECONNABORTED
case ECONNABORTED: /* Software caused connection abort */
#endif
#ifdef ECONNREFUSED
case ECONNREFUSED: /* Connection refused */
#endif
#ifdef ECONNRESET
case ECONNRESET: /* Connection reset by peer */
#endif
#ifdef EDEADLK
case EDEADLK: /* Resource deadlock avoided */
#endif
#ifdef EFBIG
case EFBIG: /* File too large */
#endif
#ifdef EHOSTDOWN
case EHOSTDOWN: /* Host is down */
#endif
#ifdef EHOSTUNREACH
case EHOSTUNREACH: /* No route to host */
#endif
#ifdef EMFILE
case EMFILE: /* Too many open files */
#endif
#ifdef ENETDOWN
case ENETDOWN: /* Network is down */
#endif
#ifdef ENETRESET
case ENETRESET: /* Network dropped connection on reset */
#endif
#ifdef ENETUNREACH
case ENETUNREACH: /* Network is unreachable */
#endif
#ifdef ENFILE
case ENFILE: /* Too many open files in system */
#endif
#ifdef ENOBUFS
case ENOBUFS: /* No buffer space available */
#endif
#ifdef ENOMEM
case ENOMEM: /* Cannot allocate memory */
#endif
#ifdef ENOSPC
case ENOSPC: /* No space left on device */
#endif
#ifdef EROFS
case EROFS: /* Read-only file system */
#endif
#ifdef ESTALE
case ESTALE: /* Stale NFS file handle */
#endif
#ifdef ETIMEDOUT
case ETIMEDOUT: /* Connection timed out */
#endif
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN && EWOULDBLOCK != EDEADLK
case EWOULDBLOCK: /* Operation would block. */
#endif
eval = EX_TEMPFAIL;
break;
default:
eval = EX_UNAVAILABLE;
break;
}
}
#if !defined(BSD4_4) && !defined(__osf__)
char *
strerror(eno)
int eno;
{
extern int sys_nerr;
extern char *sys_errlist[];
static char ebuf[60];
if (eno >= 0 && eno <= sys_nerr)
return sys_errlist[eno];
(void) sprintf(ebuf, "Error %d", eno);
return ebuf;
}
#endif /* !defined(BSD4_4) && !defined(__osf__) */
#if !HASSNPRINTF
# if __STDC__
snprintf(char *buf, size_t bufsiz, const char *fmt, ...)
# else
snprintf(buf, bufsiz, fmt, va_alist)
char *buf;
size_t bufsiz;
const char *fmt;
va_dcl
# endif
{
va_list ap;
# if __STDC__
va_start(ap, fmt);
# else
va_start(ap);
# endif
vsprintf(buf, fmt, ap);
va_end(ap);
}
#endif /* !HASSNPRINTF */
#ifdef ultrix
/*
* Copyright (c) 1987, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)mktemp.c 8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <ctype.h>
static int _gettemp();
mkstemp(path)
char *path;
{
int fd;
return (_gettemp(path, &fd) ? fd : -1);
}
/*
char *
mktemp(path)
char *path;
{
return(_gettemp(path, (int *)NULL) ? path : (char *)NULL);
}
*/
static
_gettemp(path, doopen)
char *path;
register int *doopen;
{
extern int errno;
register char *start, *trv;
struct stat sbuf;
u_int pid;
pid = getpid();
for (trv = path; *trv; ++trv); /* extra X's get set to 0's */
while (*--trv == 'X') {
*trv = (pid % 10) + '0';
pid /= 10;
}
/*
* check the target directory; if you have six X's and it
* doesn't exist this runs for a *very* long time.
*/
for (start = trv + 1;; --trv) {
if (trv <= path)
break;
if (*trv == '/') {
*trv = '\0';
if (stat(path, &sbuf) < 0)
return(0);
if (!S_ISDIR(sbuf.st_mode)) {
errno = ENOTDIR;
return(0);
}
*trv = '/';
break;
}
}
for (;;) {
if (doopen) {
if ((*doopen =
open(path, O_CREAT|O_EXCL|O_RDWR, 0600)) >= 0)
return(1);
if (errno != EEXIST)
return(0);
}
else if (stat(path, &sbuf) < 0)
return(errno == ENOENT ? 1 : 0);
/* tricky little algorithm for backward compatibility */
for (trv = start;;) {
if (!*trv)
return(0);
if (*trv == 'z')
*trv++ = 'a';
else {
if (isdigit(*trv))
*trv = 'a';
else
++*trv;
break;
}
}
}
/*NOTREACHED*/
}
#endif /* ultrix */
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