mconnect.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License, Version 1.0 only
* (the "License"). You may not use this file except in compliance
* with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* Copyright 2002 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
/* LINTLIBRARY */
# include <unistd.h>
# include <fcntl.h>
# include <errno.h>
# include <sys/utsname.h>
# include <stdlib.h>
# include <sys/types.h>
# include <sys/stat.h>
#include "lp.h"
#include "msgs.h"
#define TURN_OFF(X,F) (void)Fcntl(X, F_SETFL, (Fcntl(X, F_GETFL, 0) & ~(F)))
#if defined(__STDC__)
static MESG * connect3_2 ( void );
static int checklock ( void );
#else
static MESG * connect3_2();
static int checklock();
#endif
/*
** mconnect() - OPEN A MESSAGE PATH
*/
#if defined(__STDC__)
MESG * mconnect ( char * path, int id1, int id2 )
#else
MESG * mconnect ()
char *path;
int id1;
int id2;
#endif
{
int fd;
int wronly = 0;
int count = 0;
MESG *md;
struct stat stbuf;
/*
** invoked as mconnect(path, 0, 0)
**
** Open <path>, if isastream() is true for the returned file
** descriptor, then we're done. If not, proceed with the 3.2
** handshaking.
*/
if (path)
{
/*
** Verify that the spooler is running and that the
** <path> identifies a pipe.
** This prevents us from getting hung in the open
** and from thinking the <path> is a non-streams pipe.
*/
if (checklock() == -1)
return(NULL);
Again: if (stat(path, &stbuf) == -1)
return(NULL);
if ((stbuf.st_mode & S_IFMT) != S_IFIFO) {
if (count++ > 20)
return (NULL);
sleep(1);
goto Again;
}
if ((fd = Open(path, O_RDWR, 0)) == -1)
if ((fd = Open(path, O_WRONLY, 0)) == -1)
return(NULL);
else
wronly = 1;
if (isastream(fd) && !wronly)
{
#if defined(NOCONNLD)
int fds[2];
if (pipe(fds) != 0)
return(NULL);
if (ioctl(fd, I_SENDFD, fds[1]) != 0)
return(NULL);
(void)_Close(fd);
fd = fds[0];
(void)_Close(fds[1]);
#endif
if ((md = (MESG *)Malloc(MDSIZE)) == NULL)
{
errno = ENOMEM;
return(NULL);
}
memset(md, 0, sizeof (MESG));
md->gid = getgid();
md->on_discon = NULL;
md->readfd = fd;
md->state = MDS_IDLE;
md->type = MD_STREAM;
md->uid = getuid();
md->writefd = fd;
ResetFifoBuffer (md->readfd);
return(md);
}
return(connect3_2());
}
if (id1 > 0 && id2 > 0)
{
if ((md = (MESG *)Malloc(MDSIZE)) == NULL)
{
errno = ENOMEM;
return(NULL);
}
memset(md, 0, sizeof (MESG));
md->gid = getgid();
md->on_discon = NULL;
md->readfd = id1;
md->state = MDS_IDLE;
md->type = MD_BOUND;
md->uid = getuid();
md->writefd = id2;
ResetFifoBuffer (md->readfd);
return(md);
}
errno = EINVAL;
return(NULL);
}
#if defined(__STDC__)
static MESG * connect3_2 ( void )
#else
static MESG * connect3_2()
#endif
{
char *msgbuf = 0,
*fifo_name = "UUUUUUUUNNNNN";
int tmp_fd = -1,
size;
short status;
struct utsname ubuf;
MESG *md;
if ((md = (MESG *)Malloc(MDSIZE)) == NULL)
return(NULL);
memset(md, 0, sizeof (MESG));
md->gid = getgid();
md->state = MDS_IDLE;
md->type = MD_USR_FIFO;
md->uid = getuid();
if ((md->writefd = Open(Lp_FIFO, O_WRONLY, 0222)) == -1)
{
errno = ENOENT;
return (NULL);
}
/*
** Combine the machine node-name with the process ID to
** get a name that will be unique across the network.
** The 99999 is just a safety precaution against over-running
** the buffer.
*/
(void)uname (&ubuf);
sprintf (fifo_name, "%.8s%u", ubuf.nodename, (getpid() & 99999));
if (!(md->file = makepath(Lp_Public_FIFOs, fifo_name, (char *)0)))
{
errno = ENOMEM;
goto Error;
}
(void) Unlink(md->file);
if (Mknod(md->file, S_IFIFO | S_IRUSR, 0) == -1)
goto Error;
if ((md->readfd = Open(md->file, O_RDONLY|O_NDELAY, S_IRUSR)) == -1)
goto Error;
TURN_OFF (md->readfd, O_NDELAY);
size = putmessage((char *)0, S_NEW_QUEUE, 0, fifo_name, ubuf.nodename);
if (!(msgbuf = Malloc((unsigned)size)))
{
errno = ENOMEM;
goto Error;
}
(void) putmessage(msgbuf, S_NEW_QUEUE, 0, fifo_name, ubuf.nodename);
if (
mwrite(md, msgbuf) == -1
|| mread(md, msgbuf, size) == -1
|| getmessage(msgbuf, R_NEW_QUEUE, &status) != R_NEW_QUEUE
)
{
Free (msgbuf);
goto Error;
}
else
if (status != MOK)
{
Free(msgbuf);
errno = ENOSPC;
goto Error;
}
Free (msgbuf);
/*
* Prepare to use the fifo the Spooler created. This new FIFO can be
* read ONLY by who we said we are, so if we lied, tough luck for us!
*/
(void)Unlink (md->file); /* must exist to get here */
tmp_fd = md->readfd; /* save the old fd */
Free(md->file);
if (!(md->file = makepath(Lp_Private_FIFOs, fifo_name, (char *)0)))
{
errno = ENOMEM;
goto Error;
}
if ((md->readfd = Open(md->file, O_RDONLY|O_NDELAY, S_IRUSR)) == -1)
goto Error;
TURN_OFF (md->readfd, O_NDELAY);
size = putmessage((char *)0, S_NEW_QUEUE, 1, fifo_name, ubuf.nodename);
if (!(msgbuf = Malloc((unsigned)size)))
{
errno = ENOMEM;
goto Error;
}
(void) putmessage(msgbuf, S_NEW_QUEUE, 1, fifo_name, ubuf.nodename);
if (
mwrite(md, msgbuf) == -1
|| mread(md, msgbuf, size) == -1
|| getmessage(msgbuf, R_NEW_QUEUE, &status) != R_NEW_QUEUE
)
{
Free (msgbuf);
goto Error;
}
else
if (status != MOK)
{
Free(msgbuf);
errno = ENOSPC;
goto Error;
}
Free (msgbuf);
(void) Close(tmp_fd);
return (md);
Error:
if (md->writefd != -1)
(void) Close (md->writefd);
if (md->writefd != -1)
(void) Close (md->readfd);
if (md->file)
{
(void) Unlink (md->file);
Free (md->file);
}
if (tmp_fd != -1)
(void) Close(tmp_fd);
Free(md);
return(NULL);
}
#if defined(__STDC__)
static int checklock ( void )
#else
static int checklock()
#endif
{
int fd;
struct flock lock;
if ((fd = Open(Lp_Schedlock, O_RDONLY, 0666)) == -1)
return (-1);
/*
* Now, we try to read-lock the lock file. This can only succeed if
* the Spooler (lpsched) is down.
*/
lock.l_type = F_RDLCK;
lock.l_whence = 0;
lock.l_start = 0;
lock.l_len = 0; /* till end of file */
if (Fcntl(fd, F_SETLK, &lock) != -1 || errno != EAGAIN)
{
(void)Close (fd);
return (-1);
}
/*
* We can get here only when fcntl() == -1 && errno == EAGAIN,
* i.e., spooler (lpsched) is running.
*/
(void)Close (fd);
return(0);
}