text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Process version 3 NFSACL requests.
   *
   * Copyright (C) 2002-2003 Andreas Gruenbacher <agruen@suse.de>
   */
  
  #include "nfsd.h"
  /* FIXME: nfsacl.h is a broken header */
  #include <linux/nfsacl.h>
  #include <linux/gfp.h>
  #include "cache.h"
  #include "xdr3.h"
  #include "vfs.h"
  
  /*
   * NULL call.
   */
  static __be32
  nfsd3_proc_null(struct svc_rqst *rqstp)
  {
  	return rpc_success;
  }
  
  /*
   * Get the Access and/or Default ACL of a file.
   */
  static __be32 nfsd3_proc_getacl(struct svc_rqst *rqstp)
  {
  	struct nfsd3_getaclargs *argp = rqstp->rq_argp;
  	struct nfsd3_getaclres *resp = rqstp->rq_resp;
  	struct posix_acl *acl;
  	struct inode *inode;
  	svc_fh *fh;
  
  	fh = fh_copy(&resp->fh, &argp->fh);
  	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
  	if (resp->status != nfs_ok)
  		goto out;
  
  	inode = d_inode(fh->fh_dentry);
  
  	if (argp->mask & ~NFS_ACL_MASK) {
  		resp->status = nfserr_inval;
  		goto out;
  	}
  	resp->mask = argp->mask;
  
  	if (resp->mask & (NFS_ACL|NFS_ACLCNT)) {
  		acl = get_acl(inode, ACL_TYPE_ACCESS);
  		if (acl == NULL) {
  			/* Solaris returns the inode's minimum ACL. */
  			acl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL);
  		}
  		if (IS_ERR(acl)) {
  			resp->status = nfserrno(PTR_ERR(acl));
  			goto fail;
  		}
  		resp->acl_access = acl;
  	}
  	if (resp->mask & (NFS_DFACL|NFS_DFACLCNT)) {
  		/* Check how Solaris handles requests for the Default ACL
  		   of a non-directory! */
  		acl = get_acl(inode, ACL_TYPE_DEFAULT);
  		if (IS_ERR(acl)) {
  			resp->status = nfserrno(PTR_ERR(acl));
  			goto fail;
  		}
  		resp->acl_default = acl;
  	}
  
  	/* resp->acl_{access,default} are released in nfs3svc_release_getacl. */
  out:
  	return rpc_success;
  
  fail:
  	posix_acl_release(resp->acl_access);
  	posix_acl_release(resp->acl_default);
  	goto out;
  }
  
  /*
   * Set the Access and/or Default ACL of a file.
   */
  static __be32 nfsd3_proc_setacl(struct svc_rqst *rqstp)
  {
  	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
  	struct nfsd3_attrstat *resp = rqstp->rq_resp;
  	struct inode *inode;
  	svc_fh *fh;
  	int error;
  
  	fh = fh_copy(&resp->fh, &argp->fh);
  	resp->status = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
  	if (resp->status != nfs_ok)
  		goto out;
  
  	inode = d_inode(fh->fh_dentry);
  
  	error = fh_want_write(fh);
  	if (error)
  		goto out_errno;
  
  	fh_lock(fh);
  
  	error = set_posix_acl(&init_user_ns, inode, ACL_TYPE_ACCESS,
  			      argp->acl_access);
  	if (error)
  		goto out_drop_lock;
  	error = set_posix_acl(&init_user_ns, inode, ACL_TYPE_DEFAULT,
  			      argp->acl_default);
  
  out_drop_lock:
  	fh_unlock(fh);
  	fh_drop_write(fh);
  out_errno:
  	resp->status = nfserrno(error);
  out:
  	/* argp->acl_{access,default} may have been allocated in
  	   nfs3svc_decode_setaclargs. */
  	posix_acl_release(argp->acl_access);
  	posix_acl_release(argp->acl_default);
  	return rpc_success;
  }
  
  /*
   * XDR decode functions
   */
  
  static bool
  nfs3svc_decode_getaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  {
  	struct nfsd3_getaclargs *args = rqstp->rq_argp;
  
  	if (!svcxdr_decode_nfs_fh3(xdr, &args->fh))
  		return false;
  	if (xdr_stream_decode_u32(xdr, &args->mask) < 0)
  		return false;
  
  	return true;
  }
  
  static bool
  nfs3svc_decode_setaclargs(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  {
  	struct nfsd3_setaclargs *argp = rqstp->rq_argp;
  
  	if (!svcxdr_decode_nfs_fh3(xdr, &argp->fh))
  		return false;
  	if (xdr_stream_decode_u32(xdr, &argp->mask) < 0)
  		return false;
  	if (argp->mask & ~NFS_ACL_MASK)
  		return false;
  	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_ACL) ?
  				   &argp->acl_access : NULL))
  		return false;
  	if (!nfs_stream_decode_acl(xdr, NULL, (argp->mask & NFS_DFACL) ?
  				   &argp->acl_default : NULL))
  		return false;
  
  	return true;
  }
  
  /*
   * XDR encode functions
   */
  
  /* GETACL */
  static bool
  nfs3svc_encode_getaclres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  {
  	struct nfsd3_getaclres *resp = rqstp->rq_resp;
  	struct dentry *dentry = resp->fh.fh_dentry;
  	struct kvec *head = rqstp->rq_res.head;
  	struct inode *inode;
  	unsigned int base;
  	int n;
  	int w;
  
  	if (!svcxdr_encode_nfsstat3(xdr, resp->status))
  		return false;
  	switch (resp->status) {
  	case nfs_ok:
  		inode = d_inode(dentry);
  		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
  			return false;
  		if (xdr_stream_encode_u32(xdr, resp->mask) < 0)
  			return false;
  
  		base = (char *)xdr->p - (char *)head->iov_base;
  
  		rqstp->rq_res.page_len = w = nfsacl_size(
  			(resp->mask & NFS_ACL)   ? resp->acl_access  : NULL,
  			(resp->mask & NFS_DFACL) ? resp->acl_default : NULL);
  		while (w > 0) {
  			if (!*(rqstp->rq_next_page++))
  				return false;
  			w -= PAGE_SIZE;
  		}
  
  		n = nfsacl_encode(&rqstp->rq_res, base, inode,
  				  resp->acl_access,
  				  resp->mask & NFS_ACL, 0);
  		if (n > 0)
  			n = nfsacl_encode(&rqstp->rq_res, base + n, inode,
  					  resp->acl_default,
  					  resp->mask & NFS_DFACL,
  					  NFS_ACL_DEFAULT);
  		if (n <= 0)
  			return false;
  		break;
  	default:
  		if (!svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh))
  			return false;
  	}
  
  	return true;
  }
  
  /* SETACL */
  static bool
  nfs3svc_encode_setaclres(struct svc_rqst *rqstp, struct xdr_stream *xdr)
  {
  	struct nfsd3_attrstat *resp = rqstp->rq_resp;
  
  	return svcxdr_encode_nfsstat3(xdr, resp->status) &&
  		svcxdr_encode_post_op_attr(rqstp, xdr, &resp->fh);
  }
  
  /*
   * XDR release functions
   */
  static void nfs3svc_release_getacl(struct svc_rqst *rqstp)
  {
  	struct nfsd3_getaclres *resp = rqstp->rq_resp;
  
  	fh_put(&resp->fh);
  	posix_acl_release(resp->acl_access);
  	posix_acl_release(resp->acl_default);
  }
  
  struct nfsd3_voidargs { int dummy; };
  
  #define ST 1		/* status*/
  #define AT 21		/* attributes */
  #define pAT (1+AT)	/* post attributes - conditional */
  #define ACL (1+NFS_ACL_MAX_ENTRIES*3)  /* Access Control List */
  
  static const struct svc_procedure nfsd_acl_procedures3[3] = {
  	[ACLPROC3_NULL] = {
  		.pc_func = nfsd3_proc_null,
  		.pc_decode = nfssvc_decode_voidarg,
  		.pc_encode = nfssvc_encode_voidres,
  		.pc_argsize = sizeof(struct nfsd_voidargs),
  		.pc_ressize = sizeof(struct nfsd_voidres),
  		.pc_cachetype = RC_NOCACHE,
  		.pc_xdrressize = ST,
  		.pc_name = "NULL",
  	},
  	[ACLPROC3_GETACL] = {
  		.pc_func = nfsd3_proc_getacl,
  		.pc_decode = nfs3svc_decode_getaclargs,
  		.pc_encode = nfs3svc_encode_getaclres,
  		.pc_release = nfs3svc_release_getacl,
  		.pc_argsize = sizeof(struct nfsd3_getaclargs),
  		.pc_ressize = sizeof(struct nfsd3_getaclres),
  		.pc_cachetype = RC_NOCACHE,
  		.pc_xdrressize = ST+1+2*(1+ACL),
  		.pc_name = "GETACL",
  	},
  	[ACLPROC3_SETACL] = {
  		.pc_func = nfsd3_proc_setacl,
  		.pc_decode = nfs3svc_decode_setaclargs,
  		.pc_encode = nfs3svc_encode_setaclres,
  		.pc_release = nfs3svc_release_fhandle,
  		.pc_argsize = sizeof(struct nfsd3_setaclargs),
  		.pc_ressize = sizeof(struct nfsd3_attrstat),
  		.pc_cachetype = RC_NOCACHE,
  		.pc_xdrressize = ST+pAT,
  		.pc_name = "SETACL",
  	},
  };
  
  static unsigned int nfsd_acl_count3[ARRAY_SIZE(nfsd_acl_procedures3)];
  const struct svc_version nfsd_acl_version3 = {
  	.vs_vers	= 3,
  	.vs_nproc	= 3,
  	.vs_proc	= nfsd_acl_procedures3,
  	.vs_count	= nfsd_acl_count3,
  	.vs_dispatch	= nfsd_dispatch,
  	.vs_xdrsize	= NFS3_SVC_XDRSIZE,
  };
  
  