usr/src/sys/kern/kern_descrip.c

/*
 * Copyright (c) 1982, 1986 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 *
 *	@(#)kern_descrip.c	7.2 (Berkeley) %G%
 */

#include "param.h"
#include "systm.h"
#include "dir.h"
#include "user.h"
#include "kernel.h"
#include "inode.h"
#include "proc.h"
#include "file.h"
#include "socket.h"
#include "socketvar.h"
#include "mount.h"
#include "stat.h"

#include "ioctl.h"

/*
 * Descriptor management.
 */

/*
 * TODO:
 *	eliminate u.u_error side effects
 */

/*
 * System calls on descriptors.
 */
getdtablesize()
{

	u.u_r.r_val1 = NOFILE;
}

getdopt()
{

}

setdopt()
{

}

dup()
{
	register struct a {
		int	i;
	} *uap = (struct a *) u.u_ap;
	struct file *fp;
	int j;

	if (uap->i &~ 077) { uap->i &= 077; dup2(); return; }	/* XXX */

	GETF(fp, uap->i);
	j = ufalloc(0);
	if (j < 0)
		return;
	dupit(j, fp, u.u_pofile[uap->i] &~ UF_EXCLOSE);
}

dup2()
{
	register struct a {
		int	i, j;
	} *uap = (struct a *) u.u_ap;
	register struct file *fp;

	GETF(fp, uap->i);
	if (uap->j < 0 || uap->j >= NOFILE) {
		u.u_error = EBADF;
		return;
	}
	u.u_r.r_val1 = uap->j;
	if (uap->i == uap->j)
		return;
	if (u.u_ofile[uap->j]) {
		if (u.u_pofile[uap->j] & UF_MAPPED)
			munmapfd(uap->j);
		closef(u.u_ofile[uap->j]);
		if (u.u_error)
			return;
	}
	dupit(uap->j, fp, u.u_pofile[uap->i] &~ UF_EXCLOSE);
}

dupit(fd, fp, flags)
	int fd;
	register struct file *fp;
	register int flags;
{

	u.u_ofile[fd] = fp;
	u.u_pofile[fd] = flags;
	fp->f_count++;
	if (fd > u.u_lastfile)
		u.u_lastfile = fd;
}

/*
 * The file control system call.
 */
fcntl()
{
	register struct file *fp;
	register struct a {
		int	fdes;
		int	cmd;
		int	arg;
	} *uap;
	register i;
	register char *pop;

	uap = (struct a *)u.u_ap;
	GETF(fp, uap->fdes);
	pop = &u.u_pofile[uap->fdes];
	switch(uap->cmd) {
	case F_DUPFD:
		i = uap->arg;
		if (i < 0 || i >= NOFILE) {
			u.u_error = EINVAL;
			return;
		}
		if ((i = ufalloc(i)) < 0)
			return;
		dupit(i, fp, *pop &~ UF_EXCLOSE);
		break;

	case F_GETFD:
		u.u_r.r_val1 = *pop & 1;
		break;

	case F_SETFD:
		*pop = (*pop &~ 1) | (uap->arg & 1);
		break;

	case F_GETFL:
		u.u_r.r_val1 = fp->f_flag+FOPEN;
		break;

	case F_SETFL:
		fp->f_flag &= FCNTLCANT;
		fp->f_flag |= (uap->arg-FOPEN) &~ FCNTLCANT;
		u.u_error = fset(fp, FNDELAY, fp->f_flag & FNDELAY);
		if (u.u_error)
			break;
		u.u_error = fset(fp, FASYNC, fp->f_flag & FASYNC);
		if (u.u_error)
			(void) fset(fp, FNDELAY, 0);
		break;

	case F_GETOWN:
		u.u_error = fgetown(fp, &u.u_r.r_val1);
		break;

	case F_SETOWN:
		u.u_error = fsetown(fp, uap->arg);
		break;

	default:
		u.u_error = EINVAL;
	}
}

fset(fp, bit, value)
	struct file *fp;
	int bit, value;
{

	if (value)
		fp->f_flag |= bit;
	else
		fp->f_flag &= ~bit;
	return (fioctl(fp, (int)(bit == FNDELAY ? FIONBIO : FIOASYNC),
	    (caddr_t)&value));
}

fgetown(fp, valuep)
	struct file *fp;
	int *valuep;
{
	int error;

	switch (fp->f_type) {

	case DTYPE_SOCKET:
		*valuep = ((struct socket *)fp->f_data)->so_pgid;
		return (0);

	default:
		error = fioctl(fp, (int)TIOCGPGRP, (caddr_t)valuep);
		*valuep = -*valuep;
		return (error);
	}
}

fsetown(fp, value)
	struct file *fp;
	int value;
{
	if (fp->f_type == DTYPE_SOCKET) {
		((struct socket *)fp->f_data)->so_pgid = value;
		return (0);
	}
	if (value > 0) {
		struct proc *p = pfind(value);
		if (p == 0)
			return (ESRCH);
		value = p->p_pgrp->pg_id;
	} else
		value = -value;
	return (fioctl(fp, (int)TIOCSPGRP, (caddr_t)&value));
}

fioctl(fp, cmd, value)
	struct file *fp;
	int cmd;
	caddr_t value;
{

	return ((*fp->f_ops->fo_ioctl)(fp, cmd, value));
}

close()
{
	struct a {
		int	i;
	} *uap = (struct a *)u.u_ap;
	register int i = uap->i;
	register struct file *fp;
	register u_char *pf;

	GETF(fp, i);
	pf = (u_char *)&u.u_pofile[i];
	if (*pf & UF_MAPPED)
		munmapfd(i);
	u.u_ofile[i] = NULL;
	while (u.u_lastfile >= 0 && u.u_ofile[u.u_lastfile] == NULL)
		u.u_lastfile--;
	*pf = 0;
	closef(fp);
	/* WHAT IF u.u_error ? */
}

fstat()
{
	register struct file *fp;
	register struct a {
		int	fdes;
		struct	stat *sb;
	} *uap;
	struct stat ub;

	uap = (struct a *)u.u_ap;
	GETF(fp, uap->fdes);
	switch (fp->f_type) {

	case DTYPE_INODE:
		u.u_error = ino_stat((struct inode *)fp->f_data, &ub);
		break;

	case DTYPE_SOCKET:
		u.u_error = soo_stat((struct socket *)fp->f_data, &ub);
		break;

	default:
		panic("fstat");
		/*NOTREACHED*/
	}
	if (u.u_error == 0)
		u.u_error = copyout((caddr_t)&ub, (caddr_t)uap->sb,
		    sizeof (ub));
}

/*
 * Allocate a user file descriptor.
 */
ufalloc(i)
	register int i;
{

	for (; i < NOFILE; i++)
		if (u.u_ofile[i] == NULL) {
			u.u_r.r_val1 = i;
			u.u_pofile[i] = 0;
			if (i > u.u_lastfile)
				u.u_lastfile = i;
			return (i);
		}
	u.u_error = EMFILE;
	return (-1);
}

ufavail()
{
	register int i, avail = 0;

	for (i = 0; i < NOFILE; i++)
		if (u.u_ofile[i] == NULL)
			avail++;
	return (avail);
}

struct	file *lastf;
/*
 * Allocate a user file descriptor
 * and a file structure.
 * Initialize the descriptor
 * to point at the file structure.
 */
struct file *
falloc()
{
	register struct file *fp;
	register i;

	i = ufalloc(0);
	if (i < 0)
		return (NULL);
	if (lastf == 0)
		lastf = file;
	for (fp = lastf; fp < fileNFILE; fp++)
		if (fp->f_count == 0)
			goto slot;
	for (fp = file; fp < lastf; fp++)
		if (fp->f_count == 0)
			goto slot;
	tablefull("file");
	u.u_error = ENFILE;
	return (NULL);
slot:
	u.u_ofile[i] = fp;
	fp->f_count = 1;
	fp->f_data = 0;
	fp->f_offset = 0;
	lastf = fp + 1;
	return (fp);
}

/*
 * Convert a user supplied file descriptor into a pointer
 * to a file structure.  Only task is to check range of the descriptor.
 * Critical paths should use the GETF macro.
 */
struct file *
getf(f)
	register int f;
{
	register struct file *fp;

	if ((unsigned)f >= NOFILE || (fp = u.u_ofile[f]) == NULL) {
		u.u_error = EBADF;
		return (NULL);
	}
	return (fp);
}

/*
 * Internal form of close.
 * Decrement reference count on file structure.
 */
closef(fp)
	register struct file *fp;
{

	if (fp == NULL)
		return;
	if (fp->f_count > 1) {
		fp->f_count--;
		return;
	}
	(*fp->f_ops->fo_close)(fp);
	fp->f_count = 0;
}

/*
 * Apply an advisory lock on a file descriptor.
 */
flock()
{
	register struct a {
		int	fd;
		int	how;
	} *uap = (struct a *)u.u_ap;
	register struct file *fp;

	GETF(fp, uap->fd);
	if (fp->f_type != DTYPE_INODE) {
		u.u_error = EOPNOTSUPP;
		return;
	}
	if (uap->how & LOCK_UN) {
		ino_unlock(fp, FSHLOCK|FEXLOCK);
		return;
	}
	if ((uap->how & (LOCK_SH | LOCK_EX)) == 0)
		return;					/* error? */
	if (uap->how & LOCK_EX)
		uap->how &= ~LOCK_SH;
	/* avoid work... */
	if ((fp->f_flag & FEXLOCK) && (uap->how & LOCK_EX) ||
	    (fp->f_flag & FSHLOCK) && (uap->how & LOCK_SH))
		return;
	u.u_error = ino_lock(fp, uap->how);
}
Commit	Line	Data
	1	/*
	2	* Copyright (c) 1982, 1986 Regents of the University of California.
	3	* All rights reserved. The Berkeley software License Agreement
	4	* specifies the terms and conditions for redistribution.
	5	*
	6	* @(#)kern_descrip.c 7.2 (Berkeley) %G%
	7	*/
	8
	9	#include "param.h"
	10	#include "systm.h"
	11	#include "dir.h"
	12	#include "user.h"
	13	#include "kernel.h"
	14	#include "inode.h"
	15	#include "proc.h"
	16	#include "file.h"
	17	#include "socket.h"
	18	#include "socketvar.h"
	19	#include "mount.h"
	20	#include "stat.h"
	21
	22	#include "ioctl.h"
	23
	24	/*
	25	* Descriptor management.
	26	*/
	27
	28	/*
	29	* TODO:
	30	* eliminate u.u_error side effects
	31	*/
	32
	33	/*
	34	* System calls on descriptors.
	35	*/
	36	getdtablesize()
	37	{
	38
	39	u.u_r.r_val1 = NOFILE;
	40	}
	41
	42	getdopt()
	43	{
	44
	45	}
	46
	47	setdopt()
	48	{
	49
	50	}
	51
	52	dup()
	53	{
	54	register struct a {
	55	int i;
	56	} uap = (struct a ) u.u_ap;
	57	struct file *fp;
	58	int j;
	59
	60	if (uap->i &~ 077) { uap->i &= 077; dup2(); return; } /* XXX */
	61
	62	GETF(fp, uap->i);
	63	j = ufalloc(0);
	64	if (j < 0)
	65	return;
	66	dupit(j, fp, u.u_pofile[uap->i] &~ UF_EXCLOSE);
	67	}
	68
	69	dup2()
	70	{
	71	register struct a {
	72	int i, j;
	73	} uap = (struct a ) u.u_ap;
	74	register struct file *fp;
	75
	76	GETF(fp, uap->i);
	77	if (uap->j < 0 \|\| uap->j >= NOFILE) {
	78	u.u_error = EBADF;
	79	return;
	80	}
	81	u.u_r.r_val1 = uap->j;
	82	if (uap->i == uap->j)
	83	return;
	84	if (u.u_ofile[uap->j]) {
	85	if (u.u_pofile[uap->j] & UF_MAPPED)
	86	munmapfd(uap->j);
	87	closef(u.u_ofile[uap->j]);
	88	if (u.u_error)
	89	return;
	90	}
	91	dupit(uap->j, fp, u.u_pofile[uap->i] &~ UF_EXCLOSE);
	92	}
	93
	94	dupit(fd, fp, flags)
	95	int fd;
	96	register struct file *fp;
	97	register int flags;
	98	{
	99
	100	u.u_ofile[fd] = fp;
	101	u.u_pofile[fd] = flags;
	102	fp->f_count++;
	103	if (fd > u.u_lastfile)
	104	u.u_lastfile = fd;
	105	}
	106
	107	/*
	108	* The file control system call.
	109	*/
	110	fcntl()
	111	{
	112	register struct file *fp;
	113	register struct a {
	114	int fdes;
	115	int cmd;
	116	int arg;
	117	} *uap;
	118	register i;
	119	register char *pop;
	120
	121	uap = (struct a *)u.u_ap;
	122	GETF(fp, uap->fdes);
	123	pop = &u.u_pofile[uap->fdes];
	124	switch(uap->cmd) {
	125	case F_DUPFD:
	126	i = uap->arg;
	127	if (i < 0 \|\| i >= NOFILE) {
	128	u.u_error = EINVAL;
	129	return;
	130	}
	131	if ((i = ufalloc(i)) < 0)
	132	return;
	133	dupit(i, fp, *pop &~ UF_EXCLOSE);
	134	break;
	135
	136	case F_GETFD:
	137	u.u_r.r_val1 = *pop & 1;
	138	break;
	139
	140	case F_SETFD:
	141	pop = (pop &~ 1) \| (uap->arg & 1);
	142	break;
	143
	144	case F_GETFL:
	145	u.u_r.r_val1 = fp->f_flag+FOPEN;
	146	break;
	147
	148	case F_SETFL:
	149	fp->f_flag &= FCNTLCANT;
	150	fp->f_flag \|= (uap->arg-FOPEN) &~ FCNTLCANT;
	151	u.u_error = fset(fp, FNDELAY, fp->f_flag & FNDELAY);
	152	if (u.u_error)
	153	break;
	154	u.u_error = fset(fp, FASYNC, fp->f_flag & FASYNC);
	155	if (u.u_error)
	156	(void) fset(fp, FNDELAY, 0);
	157	break;
	158
	159	case F_GETOWN:
	160	u.u_error = fgetown(fp, &u.u_r.r_val1);
	161	break;
	162
	163	case F_SETOWN:
	164	u.u_error = fsetown(fp, uap->arg);
	165	break;
	166
	167	default:
	168	u.u_error = EINVAL;
	169	}
	170	}
	171
	172	fset(fp, bit, value)
	173	struct file *fp;
	174	int bit, value;
	175	{
	176
	177	if (value)
	178	fp->f_flag \|= bit;
	179	else
	180	fp->f_flag &= ~bit;
	181	return (fioctl(fp, (int)(bit == FNDELAY ? FIONBIO : FIOASYNC),
	182	(caddr_t)&value));
	183	}
	184
	185	fgetown(fp, valuep)
	186	struct file *fp;
	187	int *valuep;
	188	{
	189	int error;
	190
	191	switch (fp->f_type) {
	192
	193	case DTYPE_SOCKET:
	194	valuep = ((struct socket )fp->f_data)->so_pgid;
	195	return (0);
	196
	197	default:
	198	error = fioctl(fp, (int)TIOCGPGRP, (caddr_t)valuep);
	199	valuep = -valuep;
	200	return (error);
	201	}
	202	}
	203
	204	fsetown(fp, value)
	205	struct file *fp;
	206	int value;
	207	{
	208	if (fp->f_type == DTYPE_SOCKET) {
	209	((struct socket *)fp->f_data)->so_pgid = value;
	210	return (0);
	211	}
	212	if (value > 0) {
	213	struct proc *p = pfind(value);
	214	if (p == 0)
	215	return (ESRCH);
	216	value = p->p_pgrp->pg_id;
	217	} else
	218	value = -value;
	219	return (fioctl(fp, (int)TIOCSPGRP, (caddr_t)&value));
	220	}
	221
	222	fioctl(fp, cmd, value)
	223	struct file *fp;
	224	int cmd;
	225	caddr_t value;
	226	{
	227
	228	return ((*fp->f_ops->fo_ioctl)(fp, cmd, value));
	229	}
	230
	231	close()
	232	{
	233	struct a {
	234	int i;
	235	} uap = (struct a )u.u_ap;
	236	register int i = uap->i;
	237	register struct file *fp;
	238	register u_char *pf;
	239
	240	GETF(fp, i);
	241	pf = (u_char *)&u.u_pofile[i];
	242	if (*pf & UF_MAPPED)
	243	munmapfd(i);
	244	u.u_ofile[i] = NULL;
	245	while (u.u_lastfile >= 0 && u.u_ofile[u.u_lastfile] == NULL)
	246	u.u_lastfile--;
	247	*pf = 0;
	248	closef(fp);
	249	/* WHAT IF u.u_error ? */
	250	}
	251
	252	fstat()
	253	{
	254	register struct file *fp;
	255	register struct a {
	256	int fdes;
	257	struct stat *sb;
	258	} *uap;
	259	struct stat ub;
	260
	261	uap = (struct a *)u.u_ap;
	262	GETF(fp, uap->fdes);
	263	switch (fp->f_type) {
	264
	265	case DTYPE_INODE:
	266	u.u_error = ino_stat((struct inode *)fp->f_data, &ub);
	267	break;
	268
	269	case DTYPE_SOCKET:
	270	u.u_error = soo_stat((struct socket *)fp->f_data, &ub);
	271	break;
	272
	273	default:
	274	panic("fstat");
	275	/NOTREACHED/
	276	}
	277	if (u.u_error == 0)
	278	u.u_error = copyout((caddr_t)&ub, (caddr_t)uap->sb,
	279	sizeof (ub));
	280	}
	281
	282	/*
	283	* Allocate a user file descriptor.
	284	*/
	285	ufalloc(i)
	286	register int i;
	287	{
	288
	289	for (; i < NOFILE; i++)
	290	if (u.u_ofile[i] == NULL) {
	291	u.u_r.r_val1 = i;
	292	u.u_pofile[i] = 0;
	293	if (i > u.u_lastfile)
	294	u.u_lastfile = i;
	295	return (i);
	296	}
	297	u.u_error = EMFILE;
	298	return (-1);
	299	}
	300
	301	ufavail()
	302	{
	303	register int i, avail = 0;
	304
	305	for (i = 0; i < NOFILE; i++)
	306	if (u.u_ofile[i] == NULL)
	307	avail++;
	308	return (avail);
	309	}
	310
	311	struct file *lastf;
	312	/*
	313	* Allocate a user file descriptor
	314	* and a file structure.
	315	* Initialize the descriptor
	316	* to point at the file structure.
	317	*/
	318	struct file *
	319	falloc()
	320	{
	321	register struct file *fp;
	322	register i;
	323
	324	i = ufalloc(0);
	325	if (i < 0)
	326	return (NULL);
	327	if (lastf == 0)
	328	lastf = file;
	329	for (fp = lastf; fp < fileNFILE; fp++)
	330	if (fp->f_count == 0)
	331	goto slot;
	332	for (fp = file; fp < lastf; fp++)
	333	if (fp->f_count == 0)
	334	goto slot;
	335	tablefull("file");
	336	u.u_error = ENFILE;
	337	return (NULL);
	338	slot:
	339	u.u_ofile[i] = fp;
	340	fp->f_count = 1;
	341	fp->f_data = 0;
	342	fp->f_offset = 0;
	343	lastf = fp + 1;
	344	return (fp);
	345	}
	346
	347	/*
	348	* Convert a user supplied file descriptor into a pointer
	349	* to a file structure. Only task is to check range of the descriptor.
	350	* Critical paths should use the GETF macro.
	351	*/
	352	struct file *
	353	getf(f)
	354	register int f;
	355	{
	356	register struct file *fp;
	357
	358	if ((unsigned)f >= NOFILE \|\| (fp = u.u_ofile[f]) == NULL) {
	359	u.u_error = EBADF;
	360	return (NULL);
	361	}
	362	return (fp);
	363	}
	364
	365	/*
	366	* Internal form of close.
	367	* Decrement reference count on file structure.
	368	*/
	369	closef(fp)
	370	register struct file *fp;
	371	{
	372
	373	if (fp == NULL)
	374	return;
	375	if (fp->f_count > 1) {
	376	fp->f_count--;
	377	return;
	378	}
	379	(*fp->f_ops->fo_close)(fp);
	380	fp->f_count = 0;
	381	}
	382
	383	/*
	384	* Apply an advisory lock on a file descriptor.
	385	*/
	386	flock()
	387	{
	388	register struct a {
	389	int fd;
	390	int how;
	391	} uap = (struct a )u.u_ap;
	392	register struct file *fp;
	393
	394	GETF(fp, uap->fd);
	395	if (fp->f_type != DTYPE_INODE) {
	396	u.u_error = EOPNOTSUPP;
	397	return;
	398	}
	399	if (uap->how & LOCK_UN) {
	400	ino_unlock(fp, FSHLOCK\|FEXLOCK);
	401	return;
	402	}
	403	if ((uap->how & (LOCK_SH \| LOCK_EX)) == 0)
	404	return; /* error? */
	405	if (uap->how & LOCK_EX)
	406	uap->how &= ~LOCK_SH;
	407	/* avoid work... */
	408	if ((fp->f_flag & FEXLOCK) && (uap->how & LOCK_EX) \|\|
	409	(fp->f_flag & FSHLOCK) && (uap->how & LOCK_SH))
	410	return;
	411	u.u_error = ino_lock(fp, uap->how);
	412	}