V4/usr/sys/ken/sys3.c

#
/*
 *	Copyright 1973 Bell Telephone Laboratories Inc
 */

#include "../param.h"
#include "../systm.h"
#include "../reg.h"
#include "../buf.h"
#include "../filsys.h"
#include "../user.h"
#include "../inode.h"
#include "../file.h"
#include "../conf.h"

#define	CSW	0177570
struct
{
	int	csw;
};

getswit()
{

	u.u_ar0[R0] = CSW->csw;
}

gtime()
{

	u.u_ar0[R0] = time[0];
	u.u_ar0[R1] = time[1];
}

stime()
{

	if(suser()) {
		time[0] = u.u_ar0[R0];
		time[1] = u.u_ar0[R1];
		wakeup(tout);
	}
}

setuid()
{
	register uid;

	uid = u.u_ar0[R0].lobyte;
	if(u.u_ruid == uid.lobyte || suser()) {
		u.u_uid = uid;
		u.u_ruid = uid;
	}
}

getuid()
{

	u.u_ar0[R0].lobyte = u.u_ruid;
	u.u_ar0[R0].hibyte = u.u_uid;
}

setgid()
{
	register gid;

	gid = u.u_ar0[R0].lobyte;
	if(u.u_rgid == gid.lobyte || suser()) {
		u.u_gid = gid;
		u.u_rgid = gid;
	}
}

getgid()
{

	u.u_ar0[R0].lobyte = u.u_rgid;
	u.u_ar0[R0].hibyte = u.u_gid;
}

sync()
{

	update();
}

nice()
{
	register n;

	n = u.u_ar0[R0];
	if(n > 20)
		n = 20;
	if(n < 0 && !suser())
		n = 0;
	u.u_nice = n;
}

unlink()
{
	register *ip, *pp;
	extern uchar;

	pp = namei(&uchar, 2);
	if(pp == NULL)
		return;
	prele(pp);
	ip = iget(pp->i_dev, u.u_dent.u_ino);
	if(ip == NULL)
		panic("unlink -- iget");
	if((ip->i_mode&IFMT)==IFDIR && !suser())
		goto out;
	u.u_offset[1] =- DIRSIZ+2;
	u.u_base = &u.u_dent;
	u.u_count = DIRSIZ+2;
	u.u_dent.u_ino = 0;
	writei(pp);
	ip->i_nlink--;
	ip->i_flag =| IUPD;

out:
	iput(pp);
	iput(ip);
}

chdir()
{
	register *ip;
	extern uchar;

	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	if((ip->i_mode&IFMT) != IFDIR) {
		u.u_error = ENOTDIR;
	bad:
		iput(ip);
		return;
	}
	if(access(ip, IEXEC))
		goto bad;
	iput(u.u_cdir);
	u.u_cdir = ip;
	prele(ip);
}

chmod()
{
	register *ip;
	extern uchar;

	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	if(owner(ip)) {
		ip->i_mode =& ~07777;
		ip->i_mode =| u.u_arg[1]&07777;
		ip->i_flag =| IUPD;
	}
	iput(ip);
}

chown()
{
	register *ip;
	extern uchar;

	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	if(owner(ip)) {
		ip->i_uid = u.u_arg[1];
		if(u.u_uid != 0)
			ip->i_mode =& ~ISUID;
		ip->i_flag =| IUPD;
	}
	iput(ip);
}

fstat()
{
	register *fp;

	fp = getf(u.u_ar0[R0]);
	if(fp == NULL)
		return;
	stat1(fp->f_inode, u.u_arg[0]);
}

stat()
{
	register ip;
	extern uchar;

	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	stat1(ip, u.u_arg[1]);
	iput(ip);
}

stat1(ip, ub)
int *ip;
{
	register i, *bp, *cp;

	iupdat(ip);
	bp = bread(ip->i_dev, ldiv(ip->i_number+31, 16));
	cp = bp->b_addr + 32*lrem(ip->i_number+31, 16) + 24;
	ip = &(ip->i_dev);
	for(i=0; i<14; i++) {
		suword(ub, *ip++);
		ub =+ 2;
	}
	for(i=0; i<4; i++) {
		suword(ub, *cp++);
		ub =+ 2;
	}
	brelse(bp);
}

dup()
{
	register i, *fp;

	fp = getf(u.u_ar0[R0]);
	if(fp == NULL)
		return;
	if ((i = ufalloc()) < 0)
		return;
	u.u_ofile[i] = fp;
	fp->f_count++;
}

smount()
{
	int d;
	register *ip;
	register struct mount *mp, *smp;
	extern uchar;

	d = getmdev();
	if(u.u_error)
		return;
	u.u_dirp = u.u_arg[1];
	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	if(ip->i_count!=1 || (ip->i_mode&(IFBLK&IFCHR))!=0)
		goto out;
	smp = NULL;
	for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++) {
		if(mp->m_bufp != NULL) {
			if(d == mp->m_dev)
				goto out;
		} else
		if(smp == NULL)
			smp = mp;
	}
	if(smp == NULL)
		goto out;
	mp = bread(d, 1);
	if(u.u_error) {
		brelse(mp);
		goto out1;
	}
	smp->m_inodp = ip;
	smp->m_dev = d;
	smp->m_bufp = getblk(NODEV);
	bcopy(mp->b_addr, smp->m_bufp->b_addr, 256);
	smp = smp->m_bufp->b_addr;
	smp->s_ilock = 0;
	smp->s_flock = 0;
	smp->s_ronly = u.u_arg[2] & 1;
	brelse(mp);
	ip->i_flag =| IMOUNT;
	prele(ip);
	return;

out:
	u.u_error = EBUSY;
out1:
	iput(ip);
}

sumount()
{
	register d;
	register struct inode *ip;
	register struct mount *mp;

	update();
	d = getmdev();
	if(u.u_error)
		return;
	for(mp = &mount[0]; mp < &mount[NMOUNT]; mp++)
		if(mp->m_bufp!=NULL && d==mp->m_dev)
			goto found;
	u.u_error = EINVAL;
	return;

found:
	for(ip = &inode[0]; ip < &inode[NINODE]; ip++)
		if(ip->i_number!=0 && d==ip->i_dev) {
			u.u_error = EBUSY;
			return;
		}
	ip = mp->m_inodp;
	ip->i_flag =& ~IMOUNT;
	iput(ip);
	ip = mp->m_bufp;
	mp->m_bufp = NULL;
	brelse(ip);
}

getmdev()
{
	register d, *ip;
	extern uchar;

	ip = namei(&uchar, 0);
	if(ip == NULL)
		return;
	if((ip->i_mode&IFMT) != IFBLK)
		u.u_error = ENOTBLK;
	d = ip->i_addr[0];
	if(ip->i_addr[0].d_major >= nblkdev)
		u.u_error = ENXIO;
	iput(ip);
	return(d);
}