#include "../h/param.h"#include "../h/systm.h"#include "../h/dir.h"#include "../h/user.h"#include "../h/reg.h"#include "../h/inode.h"#include "../h/proc.h"#include "../h/timeb.h"/* * Everything in this file is a routine implementing a system call. *//* * return the current time (old-style entry) */gtime(){	u.u_r.r_time = time;}/* * New time entry-- return TOD with milliseconds, timezone, * DST flag */ftime(){	register struct a {		struct	timeb	*tp;	} *uap;	struct timeb t;	register unsigned ms;	uap = (struct a *)u.u_ap;	spl7();	t.time = time;	ms = lbolt;	spl0();	if (ms > HZ) {		ms -= HZ;		t.time++;	}	t.millitm = (1000*ms)/HZ;	t.timezone = TIMEZONE;	t.dstflag = DSTFLAG;	if (copyout((caddr_t)&t, (caddr_t)uap->tp, sizeof(t)) < 0)		u.u_error = EFAULT;}/* * Set the time */stime(){	register struct a {		time_t	time;	} *uap;	uap = (struct a *)u.u_ap;	if(suser())		time = uap->time;}setuid(){	register uid;	register struct a {		int	uid;	} *uap;	uap = (struct a *)u.u_ap;	uid = uap->uid;	if(u.u_ruid == uid || suser()) {		u.u_uid = uid;		u.u_procp->p_uid = uid;		u.u_ruid = uid;	}}getuid(){	u.u_r.r_val1 = u.u_ruid;	u.u_r.r_val2 = u.u_uid;}setgid(){	register gid;	register struct a {		int	gid;	} *uap;	uap = (struct a *)u.u_ap;	gid = uap->gid;	if(u.u_rgid == gid || suser()) {		u.u_gid = gid;		u.u_rgid = gid;	}}getgid(){	u.u_r.r_val1 = u.u_rgid;	u.u_r.r_val2 = u.u_gid;}getpid(){	u.u_r.r_val1 = u.u_procp->p_pid;	u.u_r.r_val2 = u.u_procp->p_ppid;}sync(){	update();}nice(){	register n;	register struct a {		int	niceness;	} *uap;	uap = (struct a *)u.u_ap;	n = uap->niceness;	if(n < 0 && !suser())		n = 0;	n += u.u_procp->p_nice;	if(n >= 2*NZERO)		n = 2*NZERO -1;	if(n < 0)		n = 0;	u.u_procp->p_nice = n;}/* * Unlink system call. * Hard to avoid races here, especially * in unlinking directories. */unlink(){	register struct inode *ip, *pp;	struct a {		char	*fname;	};	pp = namei(uchar, 2);	if(pp == NULL)		return;	/*	 * Check for unlink(".")	 * to avoid hanging on the iget	 */	if (pp->i_number == u.u_dent.d_ino) {		ip = pp;		ip->i_count++;	} else		ip = iget(pp->i_dev, u.u_dent.d_ino);	if(ip == NULL)		goto out1;	if((ip->i_mode&IFMT)==IFDIR && !suser())		goto out;	/*	 * Don't unlink a mounted file.	 */	if (ip->i_dev != pp->i_dev) {		u.u_error = EBUSY;		goto out;	}	if (ip->i_flag&ITEXT)		xrele(ip);	/* try once to free text */	if (ip->i_flag&ITEXT && ip->i_nlink==1) {		u.u_error = ETXTBSY;		goto out;	}	u.u_offset -= sizeof(struct direct);	u.u_base = (caddr_t)&u.u_dent;	u.u_count = sizeof(struct direct);	u.u_dent.d_ino = 0;	writei(pp);	ip->i_nlink--;	ip->i_flag |= ICHG;out:	iput(ip);out1:	iput(pp);}chdir(){	chdirec(&u.u_cdir);}chroot(){	if (suser())		chdirec(&u.u_rdir);}chdirec(ipp)register struct inode **ipp;{	register struct inode *ip;	struct a {		char	*fname;	};	ip = namei(uchar, 0);	if(ip == NULL)		return;	if((ip->i_mode&IFMT) != IFDIR) {		u.u_error = ENOTDIR;		goto bad;	}	if(access(ip, IEXEC))		goto bad;	prele(ip);	if (*ipp) {		plock(*ipp);		iput(*ipp);	}	*ipp = ip;	return;bad:	iput(ip);}chmod(){	register struct inode *ip;	register struct a {		char	*fname;		int	fmode;	} *uap;	uap = (struct a *)u.u_ap;	if ((ip = owner()) == NULL)		return;	ip->i_mode &= ~07777;	if (u.u_uid)		uap->fmode &= ~ISVTX;	ip->i_mode |= uap->fmode&07777;	ip->i_flag |= ICHG;	if (ip->i_flag&ITEXT && (ip->i_mode&ISVTX)==0)		xrele(ip);	iput(ip);}chown(){	register struct inode *ip;	register struct a {		char	*fname;		int	uid;		int	gid;	} *uap;	uap = (struct a *)u.u_ap;	if (!suser() || (ip = owner()) == NULL)		return;	ip->i_uid = uap->uid;	ip->i_gid = uap->gid;	ip->i_flag |= ICHG;	iput(ip);}ssig(){	register a;	struct a {		int	signo;		int	fun;	} *uap;	uap = (struct a *)u.u_ap;	a = uap->signo;	if(a<=0 || a>=NSIG || a==SIGKIL) {		u.u_error = EINVAL;		return;	}	u.u_r.r_val1 = u.u_signal[a];	u.u_signal[a] = uap->fun;	u.u_procp->p_sig &= ~(1<<(a-1));}kill(){	register struct proc *p, *q;	register a;	register struct a {		int	pid;		int	signo;	} *uap;	int f, priv;	uap = (struct a *)u.u_ap;	f = 0;	a = uap->pid;	priv = 0;	if (a==-1 && u.u_uid==0) {		priv++;		a = 0;	}	q = u.u_procp;	for(p = &proc[0]; p < &proc[NPROC]; p++) {		if(p->p_stat == NULL)			continue;		if(a != 0 && p->p_pid != a)			continue;		if(a==0 && ((p->p_pgrp!=q->p_pgrp&&priv==0) || p<=&proc[1]))			continue;		if(u.u_uid != 0 && u.u_uid != p->p_uid)			continue;		f++;		psignal(p, uap->signo);	}	if(f == 0)		u.u_error = ESRCH;}times(){	register struct a {		time_t	(*times)[4];	} *uap;	uap = (struct a *)u.u_ap;	if (copyout((caddr_t)&u.u_utime, (caddr_t)uap->times, sizeof(*uap->times)) < 0)		u.u_error = EFAULT;}profil(){	register struct a {		short	*bufbase;		unsigned bufsize;		unsigned pcoffset;		unsigned pcscale;	} *uap;	uap = (struct a *)u.u_ap;	u.u_prof.pr_base = uap->bufbase;	u.u_prof.pr_size = uap->bufsize;	u.u_prof.pr_off = uap->pcoffset;	u.u_prof.pr_scale = uap->pcscale;}/* * alarm clock signal */alarm(){	register struct proc *p;	register c;	register struct a {		int	deltat;	} *uap;	uap = (struct a *)u.u_ap;	p = u.u_procp;	c = p->p_clktim;	p->p_clktim = uap->deltat;	u.u_r.r_val1 = c;}/* * indefinite wait. * no one should wakeup(&u) */pause(){	for(;;)		sleep((caddr_t)&u, PSLEP);}/* * mode mask for creation of files */umask(){	register struct a {		int	mask;	} *uap;	register t;	uap = (struct a *)u.u_ap;	t = u.u_cmask;	u.u_cmask = uap->mask & 0777;	u.u_r.r_val1 = t;}/* * Set IUPD and IACC times on file. * Can't set ICHG. */utime(){	register struct a {		char	*fname;		time_t	*tptr;	} *uap;	register struct inode *ip;	time_t tv[2];	uap = (struct a *)u.u_ap;	if ((ip = owner()) == NULL)		return;	if (copyin((caddr_t)uap->tptr, (caddr_t)tv, sizeof(tv))) {		u.u_error = EFAULT;		return;	}	ip->i_flag |= IACC|IUPD|ICHG;	iupdat(ip, &tv[0], &tv[1]);	iput(ip);}