[unix-history] / sys / kern / sysv_shm.c

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department. Originally from University of Wisconsin.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$
 *	from: @(#)sysv_shm.c	7.15 (Berkeley) 5/13/91
 *	$Id: sysv_shm.c,v 1.5 1993/11/07 17:46:20 wollman Exp $
 */

/*
 * System V shared memory routines.
 * TEMPORARY, until mmap is in place;
 * needed now for HP-UX compatibility and X server (yech!).
 */

#ifdef SYSVSHM

#include "param.h"
#include "systm.h"
#include "kernel.h"
#include "proc.h"
#include "shm.h"
#include "malloc.h"
#include "mman.h"
#include "vm/vm.h"
#include "vm/vm_kern.h"
#include "vm/vm_inherit.h"
#include "vm/vm_pager.h"

#ifdef HPUXCOMPAT
#include "hp300/hpux/hpux.h"
#endif

/* From shm.h */
struct	shmid_ds	*shmsegs;
struct	shminfo		shminfo;

int	shmat(), shmctl(), shmdt(), shmget(); /* XXX */
int	(*shmcalls[])() = { shmat, shmctl, shmdt, shmget }; /* XXX */
int	shmtot = 0;

/*
 * Per process internal structure for managing segments.
 * Each process using shm will have an array of ``shmseg'' of these.
 */
struct	shmdesc {
	vm_offset_t	shmd_uva;
	int		shmd_id;
};

/*
 * Per segment internal structure (shm_handle).
 */
struct	shmhandle {
	vm_offset_t	shmh_kva;
	caddr_t		shmh_id;
};

static void shmufree(struct proc *, struct shmdesc *);
static void shmfree(struct shmid_ds *);

vm_map_t shm_map;	/* address space for shared memory segments */

void
shminit()
{
	register int i;
	vm_offset_t whocares1, whocares2;

	shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2,
				shminfo.shmall * NBPG, FALSE);
	if (shminfo.shmmni > SHMMMNI)
		shminfo.shmmni = SHMMMNI;
	for (i = 0; i < shminfo.shmmni; i++) {
		shmsegs[i].shm_perm.mode = 0;
		shmsegs[i].shm_perm.seq = 0;
	}
}

/*
 * Entry point for all SHM calls
 */

struct shmsys_args {
	u_int which;
};

int
shmsys(p, uap, retval)
	struct proc *p;
	struct shmsys_args *uap;
	int *retval;
{

	if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
		return (EINVAL);
	return ((*shmcalls[uap->which])(p, &uap[1], retval));
}

/*
 * Get a shared memory segment
 */

struct shmget_args {
	key_t key;
	int size;
	int shmflg;
};

int
shmget(p, uap, retval)
	struct proc *p;
	register struct shmget_args *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register struct ucred *cred = p->p_ucred;
	register int i;
	int error, size, rval = 0;
	register struct shmhandle *shmh;

	/* look up the specified shm_id */
	if (uap->key != IPC_PRIVATE) {
		for (i = 0; i < shminfo.shmmni; i++)
			if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) &&
			    shmsegs[i].shm_perm.key == uap->key) {
				rval = i;
				break;
			}
	} else
		i = shminfo.shmmni;

	/* create a new shared segment if necessary */
	if (i == shminfo.shmmni) {
		if ((uap->shmflg & IPC_CREAT) == 0)
			return (ENOENT);
		if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
			return (EINVAL);
		for (i = 0; i < shminfo.shmmni; i++)
			if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) {
				rval = i;
				break;
			}
		if (i == shminfo.shmmni)
			return (ENOSPC);
		size = clrnd(btoc(uap->size));
		if (shmtot + size > shminfo.shmall)
			return (ENOMEM);
		shp = &shmsegs[rval];
		/*
		 * We need to do a couple of things to ensure consistency
		 * in case we sleep in malloc().  We mark segment as
		 * allocated so that other shmgets() will not allocate it.
		 * We mark it as "destroyed" to insure that shmvalid() is
		 * false making most operations fail (XXX).  We set the key,
		 * so that other shmget()s will fail.
		 */
		shp->shm_perm.mode = SHM_ALLOC | SHM_DEST;
		shp->shm_perm.key = uap->key;
		shmh = (struct shmhandle *)
			malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK);
		shmh->shmh_kva = 0;
		shmh->shmh_id = (caddr_t)(0xc0000000|rval);	/* XXX */
		error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size),
				VM_PROT_ALL, VM_PROT_DEFAULT, MAP_ANON, shmh->shmh_id, 0);
		if (error) {
			free((caddr_t)shmh, M_SHM);
			shp->shm_perm.mode = 0;
			return(ENOMEM);
		}
		shp->shm_handle = (void *) shmh;
		shmtot += size;
		shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid;
		shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid;
		shp->shm_perm.mode = SHM_ALLOC | (uap->shmflg&0777);
		shp->shm_segsz = uap->size;
		shp->shm_cpid = p->p_pid;
		shp->shm_lpid = shp->shm_nattch = 0;
		shp->shm_atime = shp->shm_dtime = 0;
		shp->shm_ctime = time.tv_sec;
	} else {
		shp = &shmsegs[rval];
		/* XXX: probably not the right thing to do */
		if (shp->shm_perm.mode & SHM_DEST)
			return (EBUSY);
		if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred))
			return (error);
		if (uap->size && uap->size > shp->shm_segsz)
			return (EINVAL);
		if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL))
			return (EEXIST);
	}
	*retval = shp->shm_perm.seq * SHMMMNI + rval;
	return (0);
}

/*
 * Shared memory control
 */

struct shmctl_args {
	int shmid;
	int cmd;
	caddr_t buf;
};

/* ARGSUSED */
int
shmctl(p, uap, retval)
	struct proc *p;
	register struct shmctl_args *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register struct ucred *cred = p->p_ucred;
	struct shmid_ds sbuf;
	int error;

	if (error = shmvalid(uap->shmid))
		return (error);
	shp = &shmsegs[uap->shmid % SHMMMNI];
	switch (uap->cmd) {
	case IPC_STAT:
		if (error = ipcaccess(&shp->shm_perm, IPC_R, cred))
			return (error);
		return (copyout((caddr_t)shp, uap->buf, sizeof(*shp)));

	case IPC_SET:
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf))
			return (error);
		shp->shm_perm.uid = sbuf.shm_perm.uid;
		shp->shm_perm.gid = sbuf.shm_perm.gid;
		shp->shm_perm.mode = (shp->shm_perm.mode & ~0777)
			| (sbuf.shm_perm.mode & 0777);
		shp->shm_ctime = time.tv_sec;
		break;

	case IPC_RMID:
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		/* set ctime? */
		shp->shm_perm.key = IPC_PRIVATE;
		shp->shm_perm.mode |= SHM_DEST;
		if (shp->shm_nattch <= 0)
			shmfree(shp);
		break;

#ifdef HPUXCOMPAT
	case SHM_LOCK:
	case SHM_UNLOCK:
		/* don't really do anything, but make them think we did */
		if ((p->p_flag & SHPUX) == 0)
			return (EINVAL);
		if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
		    cred->cr_uid != shp->shm_perm.cuid)
			return (EPERM);
		break;
#endif

	default:
		return (EINVAL);
	}
	return (0);
}

/*
 * Attach to shared memory segment.
 */

struct shmat_args {
	int	shmid;
	caddr_t	shmaddr;
	int	shmflg;
};

int
shmat(p, uap, retval)
	struct proc *p;
	register struct shmat_args *uap;
	int *retval;
{
	register struct shmid_ds *shp;
	register int size;
	caddr_t uva;
	int error;
	int flags;
	vm_prot_t prot;
	struct shmdesc *shmd;

	/*
	 * Allocate descriptors now (before validity check)
	 * in case malloc() blocks.
	 */
	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	size = shminfo.shmseg * sizeof(struct shmdesc);
	if (shmd == NULL) {
		shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK);
		bzero((caddr_t)shmd, size);
		p->p_vmspace->vm_shm = (caddr_t)shmd;
	}
	if (error = shmvalid(uap->shmid))
		return (error);
	shp = &shmsegs[uap->shmid % SHMMMNI];
	if (shp->shm_handle == NULL)
		panic("shmat NULL handle");
	if (error = ipcaccess(&shp->shm_perm,
	    (uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R|IPC_W, p->p_ucred))
		return (error);
	uva = uap->shmaddr;
	if (uva && ((int)uva & (SHMLBA-1))) {
		if (uap->shmflg & SHM_RND)
			uva = (caddr_t) ((int)uva & ~(SHMLBA-1));
		else
			return (EINVAL);
	}
	/*
	 * Make sure user doesn't use more than their fair share
	 */
	for (size = 0; size < shminfo.shmseg; size++) {
		if (shmd->shmd_uva == 0)
			break;
		shmd++;
	}
	if (size >= shminfo.shmseg)
		return (EMFILE);
	size = ctob(clrnd(btoc(shp->shm_segsz)));
	prot = VM_PROT_READ;
	if ((uap->shmflg & SHM_RDONLY) == 0)
		prot |= VM_PROT_WRITE;
	flags = MAP_ANON|MAP_SHARED;
	if (uva)
		flags |= MAP_FIXED;
	else
		uva = (caddr_t)0x1000000;	/* XXX */
	error = vm_mmap(&p->p_vmspace->vm_map, &uva, (vm_size_t)size, prot, VM_PROT_DEFAULT,
	    flags, ((struct shmhandle *)shp->shm_handle)->shmh_id, 0);
	if (error)
		return(error);
	shmd->shmd_uva = (vm_offset_t)uva;
	shmd->shmd_id = uap->shmid;
	/*
	 * Fill in the remaining fields
	 */
	shp->shm_lpid = p->p_pid;
	shp->shm_atime = time.tv_sec;
	shp->shm_nattch++;
	*retval = (int) uva;
	return (0);
}

/*
 * Detach from shared memory segment.
 */

struct shmdt_args {
	caddr_t	shmaddr;
};

/* ARGSUSED */
int
shmdt(p, uap, retval)
	struct proc *p;
	struct shmdt_args *uap;
	int *retval;
{
	register struct shmdesc *shmd;
	register int i;

	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	for (i = 0; i < shminfo.shmseg; i++, shmd++)
		if (shmd->shmd_uva &&
		    shmd->shmd_uva == (vm_offset_t)uap->shmaddr)
			break;
	if (i == shminfo.shmseg)
		return(EINVAL);
	shmufree(p, shmd);
	shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid;
	return 0;
}

void
shmfork(p1, p2, isvfork)
	struct proc *p1, *p2;
	int isvfork;
{
	register struct shmdesc *shmd;
	register int size;

	/*
	 * Copy parents descriptive information
	 */
	size = shminfo.shmseg * sizeof(struct shmdesc);
	shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK);
	bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size);
	p2->p_vmspace->vm_shm = (caddr_t)shmd;
	/*
	 * Increment reference counts
	 */
	for (size = 0; size < shminfo.shmseg; size++, shmd++)
		if (shmd->shmd_uva)
			shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++;
}

void
shmexit(p)
	struct proc *p;
{
	register struct shmdesc *shmd;
	register int i;

	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	for (i = 0; i < shminfo.shmseg; i++, shmd++)
		if (shmd->shmd_uva)
			shmufree(p, shmd);
	free((caddr_t)p->p_vmspace->vm_shm, M_SHM);
	p->p_vmspace->vm_shm = NULL;
}

int
shmvalid(id)
	register int id;
{
	register struct shmid_ds *shp;

	if (id < 0 || (id % SHMMMNI) >= shminfo.shmmni)
		return(EINVAL);
	shp = &shmsegs[id % SHMMMNI];
	if (shp->shm_perm.seq == (id / SHMMMNI) &&
	    (shp->shm_perm.mode & (SHM_ALLOC|SHM_DEST)) == SHM_ALLOC)
		return(0);
	return(EINVAL);
}

/*
 * Free user resources associated with a shared memory segment
 */
static void
shmufree(p, shmd)
	struct proc *p;
	struct shmdesc *shmd;
{
	register struct shmid_ds *shp;

	shp = &shmsegs[shmd->shmd_id % SHMMMNI];
	(void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva,
			     ctob(clrnd(btoc(shp->shm_segsz))));
	shmd->shmd_id = 0;
	shmd->shmd_uva = 0;
	shp->shm_dtime = time.tv_sec;
	if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST))
		shmfree(shp);
}

/*
 * Deallocate resources associated with a shared memory segment
 */
static void
shmfree(shp)
	register struct shmid_ds *shp;
{

	if (shp->shm_handle == NULL)
		panic("shmfree");
	/*
	 * Lose our lingering object reference by deallocating space
	 * in kernel.  Pager will also be deallocated as a side-effect.
	 */
	vm_deallocate(shm_map,
		      ((struct shmhandle *)shp->shm_handle)->shmh_kva,
		      ctob(clrnd(btoc(shp->shm_segsz))));
	free((caddr_t)shp->shm_handle, M_SHM);
	shp->shm_handle = NULL;
	shmtot -= clrnd(btoc(shp->shm_segsz));
	shp->shm_perm.mode = 0;
	/*
	 * Increment the sequence number to ensure that outstanding
	 * shmids for this segment will be invalid in the event that
	 * the segment is reallocated.  Note that shmids must be
	 * positive as decreed by SVID.
	 */
	shp->shm_perm.seq++;
	if ((int)(shp->shm_perm.seq * SHMMMNI) < 0)
		shp->shm_perm.seq = 0;
}

/*
 * XXX This routine would be common to all sysV style IPC
 *     (if the others were implemented).
 */
int
ipcaccess(ipc, mode, cred)
	register struct ipc_perm *ipc;
	int mode;
	register struct ucred *cred;
{
	register int m;

	if (cred->cr_uid == 0)
		return(0);
	/*
	 * Access check is based on only one of owner, group, public.
	 * If not owner, then check group.
	 * If not a member of the group, then check public access.
	 */
	mode &= 0700;
	m = ipc->mode;
	if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) {
		m <<= 3;
		if (!groupmember(ipc->gid, cred) &&
		    !groupmember(ipc->cgid, cred))
			m <<= 3;
	}
	if ((mode&m) == mode)
		return (0);
	return (EACCES);
}
#endif /* SYSVSHM */
Commit	Line	Data
15637ed4 RG	1	/*
	2	* Copyright (c) 1988 University of Utah.
	3	* Copyright (c) 1990 The Regents of the University of California.
	4	* All rights reserved.
	5	*
	6	* This code is derived from software contributed to Berkeley by
	7	* the Systems Programming Group of the University of Utah Computer
	8	* Science Department. Originally from University of Wisconsin.
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	* 1. Redistributions of source code must retain the above copyright
	14	* notice, this list of conditions and the following disclaimer.
	15	* 2. Redistributions in binary form must reproduce the above copyright
	16	* notice, this list of conditions and the following disclaimer in the
	17	* documentation and/or other materials provided with the distribution.
	18	* 3. All advertising materials mentioning features or use of this software
	19	* must display the following acknowledgement:
	20	* This product includes software developed by the University of
	21	* California, Berkeley and its contributors.
	22	* 4. Neither the name of the University nor the names of its contributors
	23	* may be used to endorse or promote products derived from this software
	24	* without specific prior written permission.
	25	*
	26	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	27	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	28	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	29	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	30	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	31	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	32	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	33	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	34	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	35	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	36	* SUCH DAMAGE.
	37	*
600f7f07 RG	38	* from: Utah $Hdr: uipc_shm.c 1.9 89/08/14$
600f7f07 RG	39	* from: @(#)sysv_shm.c 7.15 (Berkeley) 5/13/91
4c45483e	40	* $Id: sysv_shm.c,v 1.5 1993/11/07 17:46:20 wollman Exp $
15637ed4 RG	41	*/
	42
	43	/*
	44	* System V shared memory routines.
	45	* TEMPORARY, until mmap is in place;
	46	* needed now for HP-UX compatibility and X server (yech!).
	47	*/
	48
	49	#ifdef SYSVSHM
	50
	51	#include "param.h"
	52	#include "systm.h"
	53	#include "kernel.h"
	54	#include "proc.h"
	55	#include "shm.h"
	56	#include "malloc.h"
	57	#include "mman.h"
	58	#include "vm/vm.h"
	59	#include "vm/vm_kern.h"
	60	#include "vm/vm_inherit.h"
	61	#include "vm/vm_pager.h"
	62
	63	#ifdef HPUXCOMPAT
	64	#include "hp300/hpux/hpux.h"
	65	#endif
	66
bbc3f849 GW	67	/* From shm.h */
	68	struct shmid_ds *shmsegs;
	69	struct shminfo shminfo;
	70
4c45483e GW	71	int shmat(), shmctl(), shmdt(), shmget(); /* XXX */
4c45483e GW	72	int (shmcalls[])() = { shmat, shmctl, shmdt, shmget }; / XXX */
15637ed4 RG	73	int shmtot = 0;
	74
	75	/*
	76	* Per process internal structure for managing segments.
	77	* Each process using shm will have an array of ``shmseg'' of these.
	78	*/
	79	struct shmdesc {
	80	vm_offset_t shmd_uva;
	81	int shmd_id;
	82	};
	83
	84	/*
	85	* Per segment internal structure (shm_handle).
	86	*/
	87	struct shmhandle {
	88	vm_offset_t shmh_kva;
	89	caddr_t shmh_id;
	90	};
	91
4c45483e GW	92	static void shmufree(struct proc , struct shmdesc );
	93	static void shmfree(struct shmid_ds *);
	94
15637ed4 RG	95	vm_map_t shm_map; /* address space for shared memory segments */
15637ed4 RG	96
4c45483e	97	void
15637ed4 RG	98	shminit()
	99	{
	100	register int i;
	101	vm_offset_t whocares1, whocares2;
	102
	103	shm_map = kmem_suballoc(kernel_map, &whocares1, &whocares2,
	104	shminfo.shmall * NBPG, FALSE);
	105	if (shminfo.shmmni > SHMMMNI)
	106	shminfo.shmmni = SHMMMNI;
	107	for (i = 0; i < shminfo.shmmni; i++) {
	108	shmsegs[i].shm_perm.mode = 0;
	109	shmsegs[i].shm_perm.seq = 0;
	110	}
	111	}
	112
	113	/*
	114	* Entry point for all SHM calls
	115	*/
3c7eb27c DG	116
	117	struct shmsys_args {
	118	u_int which;
	119	};
	120
4c45483e	121	int
15637ed4 RG	122	shmsys(p, uap, retval)
15637ed4 RG	123	struct proc *p;
3c7eb27c	124	struct shmsys_args *uap;
15637ed4 RG	125	int *retval;
	126	{
	127
	128	if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
	129	return (EINVAL);
	130	return ((*shmcalls[uap->which])(p, &uap[1], retval));
	131	}
	132
	133	/*
	134	* Get a shared memory segment
	135	*/
3c7eb27c DG	136
	137	struct shmget_args {
	138	key_t key;
	139	int size;
	140	int shmflg;
	141	};
	142
4c45483e	143	int
15637ed4 RG	144	shmget(p, uap, retval)
15637ed4 RG	145	struct proc *p;
3c7eb27c	146	register struct shmget_args *uap;
15637ed4 RG	147	int *retval;
	148	{
	149	register struct shmid_ds *shp;
	150	register struct ucred *cred = p->p_ucred;
	151	register int i;
	152	int error, size, rval = 0;
	153	register struct shmhandle *shmh;
	154
	155	/* look up the specified shm_id */
	156	if (uap->key != IPC_PRIVATE) {
	157	for (i = 0; i < shminfo.shmmni; i++)
	158	if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) &&
	159	shmsegs[i].shm_perm.key == uap->key) {
	160	rval = i;
	161	break;
	162	}
	163	} else
	164	i = shminfo.shmmni;
	165
	166	/* create a new shared segment if necessary */
	167	if (i == shminfo.shmmni) {
	168	if ((uap->shmflg & IPC_CREAT) == 0)
	169	return (ENOENT);
	170	if (uap->size < shminfo.shmmin \|\| uap->size > shminfo.shmmax)
	171	return (EINVAL);
	172	for (i = 0; i < shminfo.shmmni; i++)
	173	if ((shmsegs[i].shm_perm.mode & SHM_ALLOC) == 0) {
	174	rval = i;
	175	break;
	176	}
	177	if (i == shminfo.shmmni)
	178	return (ENOSPC);
	179	size = clrnd(btoc(uap->size));
	180	if (shmtot + size > shminfo.shmall)
	181	return (ENOMEM);
	182	shp = &shmsegs[rval];
	183	/*
	184	* We need to do a couple of things to ensure consistency
	185	* in case we sleep in malloc(). We mark segment as
	186	* allocated so that other shmgets() will not allocate it.
	187	* We mark it as "destroyed" to insure that shmvalid() is
	188	* false making most operations fail (XXX). We set the key,
	189	* so that other shmget()s will fail.
	190	*/
	191	shp->shm_perm.mode = SHM_ALLOC \| SHM_DEST;
	192	shp->shm_perm.key = uap->key;
	193	shmh = (struct shmhandle *)
	194	malloc(sizeof(struct shmhandle), M_SHM, M_WAITOK);
	195	shmh->shmh_kva = 0;
	196	shmh->shmh_id = (caddr_t)(0xc0000000\|rval); /* XXX */
	197	error = vm_mmap(shm_map, &shmh->shmh_kva, ctob(size),
5af262ca	198	VM_PROT_ALL, VM_PROT_DEFAULT, MAP_ANON, shmh->shmh_id, 0);
15637ed4 RG	199	if (error) {
	200	free((caddr_t)shmh, M_SHM);
	201	shp->shm_perm.mode = 0;
	202	return(ENOMEM);
	203	}
	204	shp->shm_handle = (void *) shmh;
	205	shmtot += size;
	206	shp->shm_perm.cuid = shp->shm_perm.uid = cred->cr_uid;
	207	shp->shm_perm.cgid = shp->shm_perm.gid = cred->cr_gid;
	208	shp->shm_perm.mode = SHM_ALLOC \| (uap->shmflg&0777);
	209	shp->shm_segsz = uap->size;
	210	shp->shm_cpid = p->p_pid;
	211	shp->shm_lpid = shp->shm_nattch = 0;
	212	shp->shm_atime = shp->shm_dtime = 0;
	213	shp->shm_ctime = time.tv_sec;
	214	} else {
	215	shp = &shmsegs[rval];
	216	/* XXX: probably not the right thing to do */
	217	if (shp->shm_perm.mode & SHM_DEST)
	218	return (EBUSY);
	219	if (error = ipcaccess(&shp->shm_perm, uap->shmflg&0777, cred))
	220	return (error);
	221	if (uap->size && uap->size > shp->shm_segsz)
	222	return (EINVAL);
	223	if ((uap->shmflg&IPC_CREAT) && (uap->shmflg&IPC_EXCL))
	224	return (EEXIST);
	225	}
	226	retval = shp->shm_perm.seq SHMMMNI + rval;
	227	return (0);
	228	}
	229
	230	/*
	231	* Shared memory control
	232	*/
3c7eb27c DG	233
	234	struct shmctl_args {
	235	int shmid;
	236	int cmd;
	237	caddr_t buf;
	238	};
	239
15637ed4	240	/* ARGSUSED */
4c45483e	241	int
15637ed4 RG	242	shmctl(p, uap, retval)
15637ed4 RG	243	struct proc *p;
3c7eb27c	244	register struct shmctl_args *uap;
15637ed4 RG	245	int *retval;
	246	{
	247	register struct shmid_ds *shp;
	248	register struct ucred *cred = p->p_ucred;
	249	struct shmid_ds sbuf;
	250	int error;
	251
	252	if (error = shmvalid(uap->shmid))
	253	return (error);
	254	shp = &shmsegs[uap->shmid % SHMMMNI];
	255	switch (uap->cmd) {
	256	case IPC_STAT:
	257	if (error = ipcaccess(&shp->shm_perm, IPC_R, cred))
	258	return (error);
	259	return (copyout((caddr_t)shp, uap->buf, sizeof(*shp)));
	260
	261	case IPC_SET:
	262	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	263	cred->cr_uid != shp->shm_perm.cuid)
	264	return (EPERM);
	265	if (error = copyin(uap->buf, (caddr_t)&sbuf, sizeof sbuf))
	266	return (error);
	267	shp->shm_perm.uid = sbuf.shm_perm.uid;
	268	shp->shm_perm.gid = sbuf.shm_perm.gid;
	269	shp->shm_perm.mode = (shp->shm_perm.mode & ~0777)
	270	\| (sbuf.shm_perm.mode & 0777);
	271	shp->shm_ctime = time.tv_sec;
	272	break;
	273
	274	case IPC_RMID:
	275	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	276	cred->cr_uid != shp->shm_perm.cuid)
	277	return (EPERM);
	278	/* set ctime? */
	279	shp->shm_perm.key = IPC_PRIVATE;
	280	shp->shm_perm.mode \|= SHM_DEST;
	281	if (shp->shm_nattch <= 0)
	282	shmfree(shp);
	283	break;
	284
	285	#ifdef HPUXCOMPAT
	286	case SHM_LOCK:
	287	case SHM_UNLOCK:
	288	/* don't really do anything, but make them think we did */
	289	if ((p->p_flag & SHPUX) == 0)
	290	return (EINVAL);
	291	if (cred->cr_uid && cred->cr_uid != shp->shm_perm.uid &&
	292	cred->cr_uid != shp->shm_perm.cuid)
	293	return (EPERM);
	294	break;
	295	#endif
	296
	297	default:
	298	return (EINVAL);
	299	}
	300	return (0);
	301	}
	302
	303	/*
	304	* Attach to shared memory segment.
	305	*/
3c7eb27c DG	306
	307	struct shmat_args {
	308	int shmid;
	309	caddr_t shmaddr;
	310	int shmflg;
	311	};
	312
4c45483e	313	int
15637ed4 RG	314	shmat(p, uap, retval)
15637ed4 RG	315	struct proc *p;
3c7eb27c	316	register struct shmat_args *uap;
15637ed4 RG	317	int *retval;
	318	{
	319	register struct shmid_ds *shp;
	320	register int size;
	321	caddr_t uva;
	322	int error;
	323	int flags;
	324	vm_prot_t prot;
	325	struct shmdesc *shmd;
	326
	327	/*
	328	* Allocate descriptors now (before validity check)
	329	* in case malloc() blocks.
	330	*/
	331	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	332	size = shminfo.shmseg * sizeof(struct shmdesc);
	333	if (shmd == NULL) {
	334	shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK);
	335	bzero((caddr_t)shmd, size);
	336	p->p_vmspace->vm_shm = (caddr_t)shmd;
	337	}
	338	if (error = shmvalid(uap->shmid))
	339	return (error);
	340	shp = &shmsegs[uap->shmid % SHMMMNI];
	341	if (shp->shm_handle == NULL)
	342	panic("shmat NULL handle");
	343	if (error = ipcaccess(&shp->shm_perm,
	344	(uap->shmflg&SHM_RDONLY) ? IPC_R : IPC_R\|IPC_W, p->p_ucred))
	345	return (error);
	346	uva = uap->shmaddr;
	347	if (uva && ((int)uva & (SHMLBA-1))) {
	348	if (uap->shmflg & SHM_RND)
	349	uva = (caddr_t) ((int)uva & ~(SHMLBA-1));
	350	else
	351	return (EINVAL);
	352	}
	353	/*
	354	* Make sure user doesn't use more than their fair share
	355	*/
	356	for (size = 0; size < shminfo.shmseg; size++) {
	357	if (shmd->shmd_uva == 0)
	358	break;
	359	shmd++;
	360	}
	361	if (size >= shminfo.shmseg)
	362	return (EMFILE);
	363	size = ctob(clrnd(btoc(shp->shm_segsz)));
	364	prot = VM_PROT_READ;
	365	if ((uap->shmflg & SHM_RDONLY) == 0)
	366	prot \|= VM_PROT_WRITE;
	367	flags = MAP_ANON\|MAP_SHARED;
	368	if (uva)
	369	flags \|= MAP_FIXED;
	370	else
	371	uva = (caddr_t)0x1000000; /* XXX */
5af262ca	372	error = vm_mmap(&p->p_vmspace->vm_map, &uva, (vm_size_t)size, prot, VM_PROT_DEFAULT,
15637ed4 RG	373	flags, ((struct shmhandle *)shp->shm_handle)->shmh_id, 0);
	374	if (error)
	375	return(error);
	376	shmd->shmd_uva = (vm_offset_t)uva;
	377	shmd->shmd_id = uap->shmid;
	378	/*
	379	* Fill in the remaining fields
	380	*/
	381	shp->shm_lpid = p->p_pid;
	382	shp->shm_atime = time.tv_sec;
	383	shp->shm_nattch++;
	384	*retval = (int) uva;
	385	return (0);
	386	}
	387
	388	/*
	389	* Detach from shared memory segment.
	390	*/
3c7eb27c DG	391
	392	struct shmdt_args {
	393	caddr_t shmaddr;
	394	};
	395
15637ed4	396	/* ARGSUSED */
4c45483e	397	int
15637ed4 RG	398	shmdt(p, uap, retval)
15637ed4 RG	399	struct proc *p;
3c7eb27c	400	struct shmdt_args *uap;
15637ed4 RG	401	int *retval;
	402	{
	403	register struct shmdesc *shmd;
	404	register int i;
	405
	406	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	407	for (i = 0; i < shminfo.shmseg; i++, shmd++)
	408	if (shmd->shmd_uva &&
	409	shmd->shmd_uva == (vm_offset_t)uap->shmaddr)
	410	break;
	411	if (i == shminfo.shmseg)
	412	return(EINVAL);
	413	shmufree(p, shmd);
	414	shmsegs[shmd->shmd_id % SHMMMNI].shm_lpid = p->p_pid;
4c45483e	415	return 0;
15637ed4 RG	416	}
15637ed4 RG	417
4c45483e	418	void
15637ed4 RG	419	shmfork(p1, p2, isvfork)
	420	struct proc p1, p2;
	421	int isvfork;
	422	{
	423	register struct shmdesc *shmd;
	424	register int size;
	425
	426	/*
	427	* Copy parents descriptive information
	428	*/
	429	size = shminfo.shmseg * sizeof(struct shmdesc);
	430	shmd = (struct shmdesc *)malloc(size, M_SHM, M_WAITOK);
	431	bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmd, size);
	432	p2->p_vmspace->vm_shm = (caddr_t)shmd;
	433	/*
	434	* Increment reference counts
	435	*/
	436	for (size = 0; size < shminfo.shmseg; size++, shmd++)
	437	if (shmd->shmd_uva)
	438	shmsegs[shmd->shmd_id % SHMMMNI].shm_nattch++;
	439	}
	440
4c45483e	441	void
15637ed4 RG	442	shmexit(p)
	443	struct proc *p;
	444	{
	445	register struct shmdesc *shmd;
	446	register int i;
	447
	448	shmd = (struct shmdesc *)p->p_vmspace->vm_shm;
	449	for (i = 0; i < shminfo.shmseg; i++, shmd++)
	450	if (shmd->shmd_uva)
	451	shmufree(p, shmd);
	452	free((caddr_t)p->p_vmspace->vm_shm, M_SHM);
	453	p->p_vmspace->vm_shm = NULL;
	454	}
	455
4c45483e	456	int
15637ed4 RG	457	shmvalid(id)
	458	register int id;
	459	{
	460	register struct shmid_ds *shp;
	461
	462	if (id < 0 \|\| (id % SHMMMNI) >= shminfo.shmmni)
	463	return(EINVAL);
	464	shp = &shmsegs[id % SHMMMNI];
	465	if (shp->shm_perm.seq == (id / SHMMMNI) &&
	466	(shp->shm_perm.mode & (SHM_ALLOC\|SHM_DEST)) == SHM_ALLOC)
	467	return(0);
	468	return(EINVAL);
	469	}
	470
	471	/*
	472	* Free user resources associated with a shared memory segment
	473	*/
4c45483e	474	static void
15637ed4 RG	475	shmufree(p, shmd)
	476	struct proc *p;
	477	struct shmdesc *shmd;
	478	{
	479	register struct shmid_ds *shp;
	480
	481	shp = &shmsegs[shmd->shmd_id % SHMMMNI];
	482	(void) vm_deallocate(&p->p_vmspace->vm_map, shmd->shmd_uva,
	483	ctob(clrnd(btoc(shp->shm_segsz))));
	484	shmd->shmd_id = 0;
	485	shmd->shmd_uva = 0;
	486	shp->shm_dtime = time.tv_sec;
	487	if (--shp->shm_nattch <= 0 && (shp->shm_perm.mode & SHM_DEST))
	488	shmfree(shp);
	489	}
	490
	491	/*
	492	* Deallocate resources associated with a shared memory segment
	493	*/
4c45483e	494	static void
15637ed4 RG	495	shmfree(shp)
	496	register struct shmid_ds *shp;
	497	{
	498
	499	if (shp->shm_handle == NULL)
	500	panic("shmfree");
	501	/*
	502	* Lose our lingering object reference by deallocating space
	503	* in kernel. Pager will also be deallocated as a side-effect.
	504	*/
	505	vm_deallocate(shm_map,
	506	((struct shmhandle *)shp->shm_handle)->shmh_kva,
	507	ctob(clrnd(btoc(shp->shm_segsz))));
	508	free((caddr_t)shp->shm_handle, M_SHM);
	509	shp->shm_handle = NULL;
	510	shmtot -= clrnd(btoc(shp->shm_segsz));
	511	shp->shm_perm.mode = 0;
	512	/*
	513	* Increment the sequence number to ensure that outstanding
	514	* shmids for this segment will be invalid in the event that
	515	* the segment is reallocated. Note that shmids must be
	516	* positive as decreed by SVID.
	517	*/
	518	shp->shm_perm.seq++;
	519	if ((int)(shp->shm_perm.seq * SHMMMNI) < 0)
	520	shp->shm_perm.seq = 0;
	521	}
	522
	523	/*
	524	* XXX This routine would be common to all sysV style IPC
	525	* (if the others were implemented).
	526	*/
4c45483e	527	int
15637ed4 RG	528	ipcaccess(ipc, mode, cred)
	529	register struct ipc_perm *ipc;
	530	int mode;
	531	register struct ucred *cred;
	532	{
	533	register int m;
	534
	535	if (cred->cr_uid == 0)
	536	return(0);
	537	/*
	538	* Access check is based on only one of owner, group, public.
	539	* If not owner, then check group.
	540	* If not a member of the group, then check public access.
	541	*/
	542	mode &= 0700;
	543	m = ipc->mode;
	544	if (cred->cr_uid != ipc->uid && cred->cr_uid != ipc->cuid) {
	545	m <<= 3;
	546	if (!groupmember(ipc->gid, cred) &&
	547	!groupmember(ipc->cgid, cred))
	548	m <<= 3;
	549	}
	550	if ((mode&m) == mode)
	551	return (0);
	552	return (EACCES);
	553	}
	554	#endif /* SYSVSHM */