/* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de> */

  #include <linux/sched.h>

  #include "nfsd.h"

  #include "auth.h"

  int nfsexp_flags(struct svc_rqst *rqstp, struct svc_export *exp)

  {
  	struct exp_flavor_info *f;
  	struct exp_flavor_info *end = exp->ex_flavors + exp->ex_nflavors;
  
  	for (f = exp->ex_flavors; f < end; f++) {
  		if (f->pseudoflavor == rqstp->rq_flavor)
  			return f->flags;
  	}
  	return exp->ex_flags;
  
  }

  int nfsd_setuser(struct svc_rqst *rqstp, struct svc_export *exp)
  {

  	struct group_info *rqgi;
  	struct group_info *gi;
  	struct cred *new;

  	int i;

  	int flags = nfsexp_flags(rqstp, exp);

  	int ret;

  	validate_process_creds();

  	/* discard any old override before preparing the new set */
  	revert_creds(get_cred(current->real_cred));

  	new = prepare_creds();
  	if (!new)
  		return -ENOMEM;
  
  	new->fsuid = rqstp->rq_cred.cr_uid;
  	new->fsgid = rqstp->rq_cred.cr_gid;
  
  	rqgi = rqstp->rq_cred.cr_group_info;

  	if (flags & NFSEXP_ALLSQUASH) {

  		new->fsuid = exp->ex_anon_uid;
  		new->fsgid = exp->ex_anon_gid;
  		gi = groups_alloc(0);

  		if (!gi)
  			goto oom;

  	} else if (flags & NFSEXP_ROOTSQUASH) {

  		if (!new->fsuid)
  			new->fsuid = exp->ex_anon_uid;
  		if (!new->fsgid)
  			new->fsgid = exp->ex_anon_gid;

  		gi = groups_alloc(rqgi->ngroups);
  		if (!gi)
  			goto oom;
  
  		for (i = 0; i < rqgi->ngroups; i++) {
  			if (!GROUP_AT(rqgi, i))
  				GROUP_AT(gi, i) = exp->ex_anon_gid;
  			else
  				GROUP_AT(gi, i) = GROUP_AT(rqgi, i);
  		}

  	} else {

  		gi = get_group_info(rqgi);

  	}

  
  	if (new->fsuid == (uid_t) -1)
  		new->fsuid = exp->ex_anon_uid;
  	if (new->fsgid == (gid_t) -1)
  		new->fsgid = exp->ex_anon_gid;
  
  	ret = set_groups(new, gi);
  	put_group_info(gi);

  	if (ret < 0)

  		goto error;

  	if (new->fsuid)

  		new->cap_effective = cap_drop_nfsd_set(new->cap_effective);
  	else
  		new->cap_effective = cap_raise_nfsd_set(new->cap_effective,
  							new->cap_permitted);

  	validate_process_creds();

  	put_cred(override_creds(new));

  	put_cred(new);

  	validate_process_creds();

  	return 0;

  
  oom:
  	ret = -ENOMEM;
  error:
  	abort_creds(new);

  	return ret;
  }