/*
 * Copyright 2000, International Business Machines Corporation and others.
 * All Rights Reserved.
 *
 * This software has been released under the terms of the IBM Public
 * License.  For details, see the LICENSE file in the top-level source
 * directory or online at http://www.openafs.org/dl/license10.html
 */

/*
 * osi_groups.c
 *
 * Implements:
 * Afs_xsetgroups (syscall)
 * setpag
 *
 */
#include <afsconfig.h>
#include "afs/param.h"


#include "afs/sysincludes.h"
#include "afs/afsincludes.h"
#include "afs/opr.h"
#include "afs/afs_stats.h"	/* statistics */
#include "sys/syscallargs.h"

#define NOUID   ((uid_t) -1)
#define NOGID   ((gid_t) -1)


static int
  afs_getgroups(struct ucred *cred, int ngroups, gid_t * gidset);

static int
  afs_setgroups(struct proc *proc, struct ucred **cred, int ngroups,
		gid_t * gidset, int change_parent);

int
Afs_xsetgroups(p, args, retval)
     struct proc *p;
     void *args;
     int *retval;
{
    int code = 0;
    struct vrequest treq;

    AFS_STATCNT(afs_xsetgroups);
    AFS_GLOCK();

    p = osi_curproc();

    code = afs_InitReq(&treq, p->p_rcred);
    AFS_GUNLOCK();
    if (code)
	return code;

    code = setgroups(p, args, retval);
    /*
     * Note that if there is a pag already in the new groups we don't
     * overwrite it with the old pag.
     */
    if (PagInCred(p->p_rcred) == NOPAG) {
	if (((treq.uid >> 24) & 0xff) == 'A') {
	    AFS_GLOCK();
	    /* we've already done a setpag, so now we redo it */
	    AddPag(p, treq.uid, &p->p_rcred);
	    AFS_GUNLOCK();
	}
    }
    return code;
}


int
setpag(struct proc *proc, struct ucred **cred, afs_uint32 pagvalue,
       afs_uint32 * newpag, int change_parent)
{
    gid_t gidset[NGROUPS];
    int ngroups, code;
    int j;

    AFS_STATCNT(setpag);

    if (pagvalue == -1) {
	code = afs_genpag(*cred, &pagvalue);
	if (code != 0) {
	    return code;
	}
    }

    ngroups = afs_getgroups(*cred, NGROUPS, gidset);
    /*
     * If the group list is empty, use the task's primary group as the group
     * list. Otherwise, when setting the PAG, group 0 will be set to arbitrary
     * gibberish and the PAG, which starts at group offset 1, will not be
     * properly set because the group count will be wrong (2 instead of 3).
     */
    if (ngroups == 0) {
	gidset[0] = (*cred)->cr_gid;
	ngroups = 1;
    }
    if (afs_get_pag_from_groups(gidset[1], gidset[2]) == NOPAG) {
	/* We will have to shift grouplist to make room for pag */
	if (ngroups + 2 > NGROUPS) {
	    return (E2BIG);
	}
	for (j = ngroups - 1; j >= 0; j--) {
	    gidset[j + 2] = gidset[j];
	}
	ngroups += 2;
    }
    *newpag = pagvalue;
    afs_get_groups_from_pag(*newpag, &gidset[1], &gidset[2]);
    code = afs_setgroups(proc, cred, ngroups, gidset, change_parent);
    return code;
}


static int
afs_getgroups(struct ucred *cred, int ngroups, gid_t * gidset)
{
    int ngrps, savengrps;
    gid_t *gp;

    AFS_STATCNT(afs_getgroups);
    savengrps = ngrps = opr_min(ngroups, cred->cr_ngroups);
    gp = cred->cr_groups;
    while (ngrps--)
	*gidset++ = *gp++;
    return savengrps;
}


static int
afs_setgroups(struct proc *proc, struct ucred **cred, int ngroups,
	      gid_t * gidset, int change_parent)
{
    struct ucred *cr = *cred;
    int i;

    AFS_STATCNT(afs_setgroups);

    if (ngroups > NGROUPS)
	return EINVAL;

    if (!change_parent)
	cr = crcopy(cr);

    for (i = 0; i < ngroups; i++)
	cr->cr_groups[i] = gidset[i];
    for (i = ngroups; i < NGROUPS; i++)
	cr->cr_groups[i] = NOGROUP;
    cr->cr_ngroups = ngroups;

    *cred = cr;
    return (0);
}
