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coherent

/* $Header: /var/lib/cvsd/repos/coherent/coherent/b/kernel/coh.386/sys2.c,v 1.1.1.1 2019/05/29 04:56:37 root Exp $ */
/* (lgl-
 *	The information contained herein is a trade secret of Mark Williams
 *	Company, and  is confidential information.  It is provided  under a
 *	license agreement,  and may be  copied or disclosed  only under the
 *	terms of  that agreement.  Any  reproduction or disclosure  of this
 *	material without the express written authorization of Mark Williams
 *	Company or pursuant to the license agreement is unlawful.
 *
 *	COHERENT Version 4.0
 *	Copyright (c) 1982, 1993.
 *	All rights reserved.
 -lgl) */
/*
 * Coherent.
 * System calls (filesystem related).
 */
#include <sys/coherent.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/fd.h>
#include <sys/ino.h>
#include <sys/inode.h>
#include <sys/mount.h>
#include <sys/sched.h>
#include <sys/stat.h>

/*
 * Determine accessibility of the given file.
 */
uaccess(np, mode)
char *np;
register int mode;
{
	register INODE *ip;
	register int r;

	schizo();
	r = ftoi(np, 'r');
	schizo();
	if (r)
		return;
	ip = u.u_cdiri;
	if ((mode&imode(ip, u.u_ruid, u.u_rgid)) != mode)
		u.u_error = EACCES;
	idetach(ip);
	return 0;
}

/*
 * Schizo - swap real and effective id's.
 */
schizo()
{
	register int t;

	t = u.u_uid;
	u.u_uid = u.u_ruid;
	u.u_ruid = t;
	t = u.u_gid;
	u.u_gid = u.u_rgid;
	u.u_rgid = t;
}

/*
 * Turn accounting on or off.
 */
uacct(np)
register char *np;
{
	register INODE *ip;

	if (super() == 0)
		return;
	if (np == NULL) {
		if (acctip == NULL) {
			u.u_error = EINVAL;
			return;
		}
		ldetach(acctip);
		acctip = NULL;
	} else {
		if (acctip != NULL) {
			u.u_error = EINVAL;
			return;
		}
		if (ftoi(np, 'r'))
			return;
		ip = u.u_cdiri;
		if ((ip->i_mode&IFMT) != IFREG) {
			u.u_error = EINVAL;
			idetach(ip);
			return;
		}
		iunlock(ip);
		acctip = ip;
	}
	return 0;
}

/*
 * Set current directory.
 */
uchdir(np)
char *np;
{
	setcdir(np, &u.u_cdir);
	return 0;
}

/*
 * Given a directory name and a pointer to a working directory pointer,
 * Save the inode associated with the directory name in the working
 * directory pointer and release the old one.  This is used to change
 * working and root directories.
 */
setcdir(np, ipp)
char *np;
register INODE **ipp;
{
	register INODE *ip;

	if (ftoi(np, 'r'))
		return;
	ip = u.u_cdiri;
	if ((ip->i_mode&IFMT) != IFDIR) {
		u.u_error = ENOTDIR;
		idetach(ip);
		return;
	}
	if (iaccess(ip, IPE) == 0) {
		u.u_error = EACCES;
		idetach(ip);
		return;
	}
	iunlock(ip);
	ldetach(*ipp);
	*ipp = ip;
}

/*
 * Change the mode of a file.
 */
uchmod(np, mode)
char *np;
{
	register INODE *ip;

	if (ftoi(np, 'r'))
		return;
	ip = u.u_cdiri;
	if (owner(ip->i_uid)) {
		if (u.u_uid)
			mode &= ~ISVTXT;
		ip->i_mode &= IFMT;
		ip->i_mode |= mode&~IFMT;
		icrt(ip);	/* chmod - ctime */
	}
	idetach(ip);
	return 0;
}

/*
 * Change owner and group of a file.
 */
uchown(np, uid, gid)
char *np;
{
	register INODE *ip;

	if (ftoi(np, 'r'))
		return;
	ip = u.u_cdiri;
	if (super()) {
		ip->i_mode &= ~(ISUID | ISGID);  /* clear any setuid/setgid */
		ip->i_uid = uid;
		ip->i_gid = gid;
		icrt(ip);	/* chown - ctime */
	}
	idetach(ip);
	return 0;
}

/*
 * Set root directory.
 */
uchroot(np)
register char *np;
{
	if (super())
		setcdir(np, &u.u_rdir);
	return 0;
}

/*
 * Close the given file descriptor.
 */
uclose(fd)
{
	fdclose(fd);
	return 0;
}

/*
 * Create a file with the given mode.
 */
ucreat(np, mode)
char *np;
register int mode;
{
	return(uopen(np, O_WRONLY|O_CREAT|O_TRUNC, mode));
}

/*
 * Duplicate a file descriptor.
 */
udup(ofd)
{
	return ufcntl(ofd, F_DUPFD, 0);
}

/*
 * Given a file descriptor, return a status structure.
 */
ufstat(fd, stp)
struct stat *stp;
{
	register INODE *ip;
	register FD *fdp;
	struct stat stat;

	if ((fdp=fdget(fd)) == NULL)
		return;
	ip = fdp->f_ip;
	istat(ip, &stat);
	kucopy(&stat, stp, sizeof(stat));
	return 0;
}

/*
 * File control.
 */
ufcntl( fd, cmd, arg )
int fd, cmd, arg;
{
	register FD * fdp;
	FLOCK sfl;

	T_VLAD(2, printf("fcntl(%d,%x,%x) ", fd, cmd, arg));

	/*
	 * Validate file descriptor.
	 */
	if ( (fd < 0) || (fd >= NOFILE) || ((fdp = u.u_filep[fd]) == 0) ) {
		u.u_error = EBADF;
		return;
	}

	switch ( cmd ) {

	case F_DUPFD:
		/*
		 * Validate base file descriptor.
		 */
		if ( (arg < 0) || (arg >= NOFILE) ) {
			u.u_error = EINVAL;
			return;
		}

		/*
		 * Search for next available file descriptor.
		 */
		do {
			if ( u.u_filep[arg] == 0 ) {
				u.u_filep[arg] = fdp;
				fdp->f_refc++;
				return arg;
			}
		} while ( ++arg < NOFILE );

		u.u_error = EMFILE;
		return;

	case F_SETFL:
		fdp->f_flag &= ~(IPNDLY|IPAPPEND);
		if ( arg & O_NDELAY )
			fdp->f_flag |= IPNDLY;
		if ( arg & O_APPEND )
			fdp->f_flag |= IPAPPEND;
		/* no break */

	case F_GETFL:
		switch ( fdp->f_flag & (IPR+IPW) ) {
		case IPR: arg = O_RDONLY; break;
		case IPW: arg = O_WRONLY; break;
		default:  arg = O_RDWR;   break;
		}
		if ( fdp->f_flag & IPNDLY )
			arg |= O_NDELAY;
		if ( fdp->f_flag & IPAPPEND )
			arg |= O_APPEND;
		return arg;

	case F_GETLK:
	case F_SETLK:
	case F_SETLKW:
		ukcopy(*(FLOCK **)&arg, &sfl, sizeof(FLOCK));
		if (u.u_error)
			return -1;
		if (rlock(fdp, cmd, &sfl))
			return -1;
		if (cmd == F_GETLK) {
			kucopy(&sfl, *(FLOCK **)&arg, sizeof(FLOCK));
			if (u.u_error)
				return -1;
		}
		return 0;

	case F_GETFD:
		return fdp->f_flag2 & FD_CLOEXEC;

	case F_SETFD:
		if (arg & FD_CLOEXEC)
			fdp->f_flag2 |= FD_CLOEXEC;
		else
			fdp->f_flag2 &= ~FD_CLOEXEC;
		return 0;

	default:
		T_VLAD(0x02,
		  printf("'fcntl - unknown cmd=%d arg=0x0%x' ", cmd, arg));
		u.u_error = EINVAL;
	}
}

/*
 * Device control information.
 */
uioctl(fd, r, argp)
struct sgttyb *argp;
{
	register FD *fdp;
	register INODE *ip;
	register int mode;


	T_PIGGY( 0x8, printf("uioctl(%d, 0x%x, 0x%x)", fd, r, argp); );

	if ((fdp=fdget(fd)) == NULL)
		return;
	ip = fdp->f_ip;
	mode = ip->i_mode&IFMT;
	if (mode!=IFCHR && mode!=IFBLK) {
		u.u_error = ENOTTY;
		return;
	}
	dioctl(ip->i_a.i_rdev, r, argp);
	return 0;
}

/*
 * Create a link, `np2' to the already existing file `np1'.
 */
ulink(np1, np2)
char *np1;
char *np2;
{
	register INODE *ip1;

	if (ftoi(np1, 'r'))
		return;
	ip1 = u.u_cdiri;
	if ((ip1->i_mode&IFMT)==IFDIR && super()==0) {
		idetach(ip1);
		return;
	}
	iunlock(ip1);
	if (ftoi(np2, 'c')) {
		ldetach(ip1);
		return;
	}
	if (u.u_cdiri != NULL) {
		u.u_error = EEXIST;
		idetach(u.u_cdiri);
		ldetach(ip1);
		return;
	}
	if (ip1->i_dev != u.u_pdiri->i_dev) {
		u.u_error = EXDEV;
		idetach(u.u_pdiri);
		ldetach(ip1);
		return;
	}
	if (iaccess(u.u_pdiri, IPW) == 0) {
		idetach(u.u_pdiri);
		ldetach(ip1);
		return;
	}
	idirent(ip1->i_ino);
	idetach(u.u_pdiri);
	ilock(ip1);
	/* idirent() can fail during iwrite. In this case we should not 
         * increase link count. 
	 * As result of this old bug, 286 mkdir utility destroys file 
	 * system when runs out of free blocks.
	 */
	if (!u.u_error)
		ip1->i_nlink++;
	icrt(ip1);	/* link - ctime */
	idetach(ip1);
	return 0;
}

/*
 * Seek on the given file descriptor.
 */
off_t
ulseek(fd, off, w)
register off_t off;
{
	register FD *fdp;
	register INODE *ip;

	if ((fdp=fdget(fd)) == NULL)
		return;
	ip = fdp->f_ip;
	if ((ip->i_mode&IFMT) == IFPIPE) {
		u.u_error = ESPIPE;
		return;
	}
	switch (w) {
	case 0:
		break;
	case 1:
		off += fdp->f_seek;
		break;
	case 2:
		off += ip->i_size;
		break;
	default:
		u.u_error = EINVAL;
		return;
	}

	if (off < 0) {
		u.u_error = EINVAL;
		return;
	}

	fdp->f_seek = off;
	return (off);
}

/*
 * Create a special file.
 */
umknod(np, mode, rdev)
char *np;
dev_t rdev;
{
	register INODE *ip;
	register int type;

	type = mode&IFMT;
	if (type!=IFPIPE && super()==0)
		return;
	if (type!=IFBLK && type!=IFCHR)
		rdev = 0;
	if (ftoi(np, 'c'))
		return;
	if ((ip=u.u_cdiri) != NULL) {
		u.u_error = EEXIST;
		idetach(ip);
		return;
	}
	if ((ip=imake(mode, rdev)) != NULL)
		idetach(ip);
	return 0;
}

/*
 * Mount the device `sp' on the pathname `np'.  The flag, `f',
 * indicates that the device is to be mounted read only.
 */
umount(sp, np, f)
char *sp;
char *np;
{
	register INODE *ip;
	register MOUNT *mp;
	register dev_t rdev;
	register int mode;

	if (ftoi(sp, 'r'))
		return;
	ip = u.u_cdiri;
	if (iaccess(ip, IPR|IPW) == 0)
		goto err;
	mode = ip->i_mode;
	rdev = ip->i_a.i_rdev;
	if ((mode&IFMT) != IFBLK) {
		u.u_error = ENOTBLK;
		goto err;
	}
	idetach(ip);
	if (ftoi(np, 'r'))
		return;
	ip = u.u_cdiri;
	if (iaccess(ip, IPR) == 0)
		goto err;
	if ((ip->i_mode&IFMT) != IFDIR) {
		u.u_error = ENOTDIR;
		goto err;
	}
	/* Check for current directory, open, or mount directory */
	if (ip->i_refc > 1 || ip->i_ino == ROOTIN) {
		u.u_error = EBUSY;
		goto err;
	}
	for (mp=mountp; mp!=NULL; mp=mp->m_next) {
		if (mp->m_dev == rdev) {
			u.u_error = EBUSY;
			goto err;
		}
	}
	if ((mp=fsmount(rdev, f)) == NULL)
		goto err;
	mp->m_ip = ip;
	ip->i_flag |= IFMNT;
	ip->i_refc++;
err:
	idetach(ip);
	return 0;
}

/*
 * Poll devices for input/output events.
 */
int
upoll(pollfds, npoll, msec)
struct pollfd * pollfds;
unsigned long npoll;
int msec;
{
	register struct pollfd * pollp;	/* current poll pointer		 */
	register FD *	fdp;		/* current file descriptor ptr	 */
	auto	 int	fd;		/* current file descriptor	 */
	auto	 int	rev;		/* last event report received	 */
	auto	 int	nev;		/* number non-zero event reports */
	auto	 int	i;
	char * cp;
	int ret = -1;

	/*
	 * Validate number of polls.
	 */
	if ((npoll < 0) || (npoll > NOFILE)) {
		u.u_error = EINVAL;
		goto poll_done;
	}

	/*
	 * If there are any fd's to poll
	 *   validate address of polling information.
	 * npoll of 0 is legal, allows user a short delay.
	 */
	if (npoll)
		if ((pollfds == NULL)
		  || !useracc(pollfds, npoll*sizeof(struct pollfd), 1)) {
			u.u_error = EFAULT;
			goto poll_done;
		}

	for (;;) {
		/*
		 * Service each poll in turn.
		 */
		for (nev=0, i=npoll, pollp = pollfds; i > 0; --i, pollp++) {

			/*
			 * Fetch file descriptor.
			 */
			fd = getuwd(&pollp->fd);

			/*
			 * Ignore negative file descriptors.
			 */
			if (fd < 0) {
				rev = 0;
				goto remember;
			}

#if 1
			/*
			 * Ignore file descriptors that are too large.
			 */
			if (fd >= NOFILE) {
				rev = 0;
				goto remember;
			}
#else
/* For now, msg polling is deleted. */
			/*
			 * Poll message queue.
			 */
			if (fd >= NOFILE) {
				rev = msgpoll(fd, getusd(&pollp->events), msec);
				goto remember;
			}
#endif

			/*
			 * Validate file descriptor.
			 */
			if ((fdp = u.u_filep[fd]) == 0) {
				rev = POLLNVAL;
				goto remember;
			}

			switch ( fdp->f_ip->i_mode & IFMT ) {
			case IFCHR:
				rev = dpoll(fdp->f_ip->i_a.i_rdev,
					getusd(&pollp->events)&0xffff, msec);
				break;
			case IFPIPE:
				rev = ppoll(fdp->f_ip,
					getusd(&pollp->events)&0xffff, msec);
				break;
			default:
				printf("polling illegal dev: fd=%d mode=%x\n",
					fd, fdp->f_ip->i_mode);
				rev = POLLNVAL;
				break;
			}

			/*
			 * Remember reponses.
			 */
remember:
			cp = (char *)(&pollp->revents);
			putusd(cp, rev);

			/*
			 * Record number of non-zero responses.
			 */
			if (rev)
				nev++;
		}

		/*
		 * Non-blocking poll or poll response received.
		 */
		if ( (nev != 0) || (msec == 0) ) {
			pollexit();
			ret = nev;
			goto poll_done;
		}

		/*
		 * Schedule wakeup timer if positive delay interval given
 		 * and the timer is not currently set.
		 */
		if ( (msec > 0) && (cprocp->p_polltim.t_func == NULL) ) {
			/*
			 * Convert milliseconds to clock ticks.
			 */
			msec += (1000 / HZ) - 1;
			msec /= (1000 / HZ);
			timeout(&cprocp->p_polltim, msec,
				 wakeup, &cprocp->p_polls);
		}

		/*
		 * Wake for polled event, poll timeout, or signal.
		 */
		x_sleep(&cprocp->p_polls, pritty, slpriSigCatch, "poll");
		/* Wakeup for polled event, poll timeout, or signal.  */

		/*
		 * Terminate event monitoring.
		 */
		pollexit();

		/*
		 * Signal woke us up.
		 */
		if (nondsig()) {
			u.u_error = EINTR;
			goto poll_done;
		}
		/*
 		 * We were woken up by timeout wakeup.
 		 */
		if ( (msec > 0) && (cprocp->p_polltim.t_lbolt <= lbolt) ) {
			ret = 0;
			goto poll_done;
		}
	}

poll_done:
	/*
	 * Cancel timeout
 	 */
	if ( (msec > 0) && (cprocp->p_polltim.t_func != NULL) )
		timeout(&cprocp->p_polltim, 0, NULL, NULL);

	return ret;
}

/*
 * Suspend execution for a short interval.
 *
 * Return the number of milliseconds actually slept.
 * Shares use of cprocp->p_polltim with upoll().
 */
int
unap(msec)
int msec;
{
	int ret, lbolt0;
	int ticksToWait, ticksWaited;

	if (msec <= 0)
		return 0;

	/*
	 * Convert milliseconds to clock ticks.
	 *
	 * Wait for at least the specified number of milliseconds.
	 * For 100 Hz clock, if nap is for 11 msec, timeout is for 2 ticks.
	 */
	ticksToWait = ((msec * HZ) + 999) / 1000;
	timeout(&cprocp->p_polltim, ticksToWait, wakeup, &cprocp->p_polls);

	/*
	 * Wake for timeout or signal.
	 */
	lbolt0 = lbolt;
	if (x_sleep(&cprocp->p_polls, pritty, slpriSigCatch, "nap")) {
		/*
		 * Signal woke us up.
		 */
		u.u_error = EINTR;
		goto napDone;
	} else {
		/*
		 * We were awakened by a timeout.
		 * Return number of milliseconds actually waited.
		 */
		ticksWaited = lbolt - lbolt0;
		if (ticksWaited >= 0)
			ret = (ticksWaited * 1000) / HZ;
		else
			ret = 0;
		goto napDone;
	}

napDone:
	/*
	 * Cancel timeout
 	 */
	timeout(&cprocp->p_polltim, 0, NULL, NULL);

	return ret;
}

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