// 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"

#define RETURN_STATUS(st)       { resp->status = (st); return (st); }

/*
 * NULL call.
 */
static __be32
nfsd3_proc_null(struct svc_rqst *rqstp)
{
        return nfs_ok;
}

/*
 * 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;
        __be32 nfserr = 0;

        fh = fh_copy(&resp->fh, &argp->fh);
        nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_NOP);
        if (nfserr)
                RETURN_STATUS(nfserr);

        inode = d_inode(fh->fh_dentry);

        if (argp->mask & ~NFS_ACL_MASK)
                RETURN_STATUS(nfserr_inval);
        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)) {
                        nfserr = 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)) {
                        nfserr = nfserrno(PTR_ERR(acl));
                        goto fail;
                }
                resp->acl_default = acl;
        }

        /* resp->acl_{access,default} are released in nfs3svc_release_getacl. */
        RETURN_STATUS(0);

fail:
        posix_acl_release(resp->acl_access);
        posix_acl_release(resp->acl_default);
        RETURN_STATUS(nfserr);
}

/*
 * 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;
        __be32 nfserr = 0;
        int error;

        fh = fh_copy(&resp->fh, &argp->fh);
        nfserr = fh_verify(rqstp, &resp->fh, 0, NFSD_MAY_SATTR);
        if (nfserr)
                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(inode, ACL_TYPE_ACCESS, argp->acl_access);
        if (error)
                goto out_drop_lock;
        error = set_posix_acl(inode, ACL_TYPE_DEFAULT, argp->acl_default);

out_drop_lock:
        fh_unlock(fh);
        fh_drop_write(fh);
out_errno:
        nfserr = 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_STATUS(nfserr);
}

/*
 * XDR decode functions
 */
static int nfs3svc_decode_getaclargs(struct svc_rqst *rqstp, __be32 *p)
{
        struct nfsd3_getaclargs *args = rqstp->rq_argp;

        p = nfs3svc_decode_fh(p, &args->fh);
        if (!p)
                return 0;
        args->mask = ntohl(*p); p++;

        return xdr_argsize_check(rqstp, p);
}


static int nfs3svc_decode_setaclargs(struct svc_rqst *rqstp, __be32 *p)
{
        struct nfsd3_setaclargs *args = rqstp->rq_argp;
        struct kvec *head = rqstp->rq_arg.head;
        unsigned int base;
        int n;

        p = nfs3svc_decode_fh(p, &args->fh);
        if (!p)
                return 0;
        args->mask = ntohl(*p++);
        if (args->mask & ~NFS_ACL_MASK ||
            !xdr_argsize_check(rqstp, p))
                return 0;

        base = (char *)p - (char *)head->iov_base;
        n = nfsacl_decode(&rqstp->rq_arg, base, NULL,
                          (args->mask & NFS_ACL) ?
                          &args->acl_access : NULL);
        if (n > 0)
                n = nfsacl_decode(&rqstp->rq_arg, base + n, NULL,
                                  (args->mask & NFS_DFACL) ?
                                  &args->acl_default : NULL);
        return (n > 0);
}

/*
 * XDR encode functions
 */

/* GETACL */
static int nfs3svc_encode_getaclres(struct svc_rqst *rqstp, __be32 *p)
{
        struct nfsd3_getaclres *resp = rqstp->rq_resp;
        struct dentry *dentry = resp->fh.fh_dentry;

        p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);
        if (resp->status == 0 && dentry && d_really_is_positive(dentry)) {
                struct inode *inode = d_inode(dentry);
                struct kvec *head = rqstp->rq_res.head;
                unsigned int base;
                int n;
                int w;

                *p++ = htonl(resp->mask);
                if (!xdr_ressize_check(rqstp, p))
                        return 0;
                base = (char *)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 0;
                        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 0;
        } else
                if (!xdr_ressize_check(rqstp, p))
                        return 0;

        return 1;
}

/* SETACL */
static int nfs3svc_encode_setaclres(struct svc_rqst *rqstp, __be32 *p)
{
        struct nfsd3_attrstat *resp = rqstp->rq_resp;

        p = nfs3svc_encode_post_op_attr(rqstp, p, &resp->fh);

        return xdr_ressize_check(rqstp, p);
}

/*
 * 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);
}

#define nfs3svc_decode_voidargs         NULL
#define nfs3svc_release_void            NULL
#define nfsd3_setaclres                 nfsd3_attrstat
#define nfsd3_voidres                   nfsd3_voidargs
struct nfsd3_voidargs { int dummy; };

#define PROC(name, argt, rest, relt, cache, respsize)                   \
{                                                                       \
        .pc_func        = nfsd3_proc_##name,                            \
        .pc_decode      = nfs3svc_decode_##argt##args,                  \
        .pc_encode      = nfs3svc_encode_##rest##res,                   \
        .pc_release     = nfs3svc_release_##relt,                       \
        .pc_argsize     = sizeof(struct nfsd3_##argt##args),            \
        .pc_ressize     = sizeof(struct nfsd3_##rest##res),             \
        .pc_cachetype   = cache,                                        \
        .pc_xdrressize  = respsize,                                     \
}

#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[] = {
  PROC(null,    void,           void,           void,     RC_NOCACHE, ST),
  PROC(getacl,  getacl,         getacl,         getacl,   RC_NOCACHE, ST+1+2*(1+ACL)),
  PROC(setacl,  setacl,         setacl,         fhandle,  RC_NOCACHE, ST+pAT),
};

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,
};