// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2014-2016 Christoph Hellwig.
 */
#include <linux/sunrpc/svc.h>
#include <linux/exportfs.h>
#include <linux/iomap.h>
#include <linux/nfs4.h>

#include "nfsd.h"
#include "blocklayoutxdr.h"
#include "vfs.h"

#define NFSDDBG_FACILITY        NFSDDBG_PNFS


/**
 * nfsd4_block_encode_layoutget - encode block/scsi layout extent array
 * @xdr: stream for data encoding
 * @lgp: layoutget content, actually an array of extents to encode
 *
 * Encode the opaque loc_body field in the layoutget response. Since the
 * pnfs_block_layout4 and pnfs_scsi_layout4 structures on the wire are
 * the same, this function is used by both layout drivers.
 *
 * Return values:
 *   %nfs_ok: Success, all extents encoded into @xdr
 *   %nfserr_toosmall: Not enough space in @xdr to encode all the data
 */
__be32
nfsd4_block_encode_layoutget(struct xdr_stream *xdr,
                const struct nfsd4_layoutget *lgp)
{
        const struct pnfs_block_layout *bl = lgp->lg_content;
        u32 i, len = sizeof(__be32) + bl->nr_extents * PNFS_BLOCK_EXTENT_SIZE;
        __be32 *p;

        p = xdr_reserve_space(xdr, sizeof(__be32) + len);
        if (!p)
                return nfserr_toosmall;

        *p++ = cpu_to_be32(len);
        *p++ = cpu_to_be32(bl->nr_extents);

        for (i = 0; i < bl->nr_extents; i++) {
                const struct pnfs_block_extent *bex = bl->extents + i;

                p = svcxdr_encode_deviceid4(p, &bex->vol_id);
                p = xdr_encode_hyper(p, bex->foff);
                p = xdr_encode_hyper(p, bex->len);
                p = xdr_encode_hyper(p, bex->soff);
                *p++ = cpu_to_be32(bex->es);
        }

        return nfs_ok;
}

static int
nfsd4_block_encode_volume(struct xdr_stream *xdr, struct pnfs_block_volume *b)
{
        __be32 *p;
        int len;

        switch (b->type) {
        case PNFS_BLOCK_VOLUME_SIMPLE:
                len = 4 + 4 + 8 + 4 + (XDR_QUADLEN(b->simple.sig_len) << 2);
                p = xdr_reserve_space(xdr, len);
                if (!p)
                        return -ETOOSMALL;

                *p++ = cpu_to_be32(b->type);
                *p++ = cpu_to_be32(1);  /* single signature */
                p = xdr_encode_hyper(p, b->simple.offset);
                p = xdr_encode_opaque(p, b->simple.sig, b->simple.sig_len);
                break;
        case PNFS_BLOCK_VOLUME_SCSI:
                len = 4 + 4 + 4 + 4 + (XDR_QUADLEN(b->scsi.designator_len) << 2) + 8;
                p = xdr_reserve_space(xdr, len);
                if (!p)
                        return -ETOOSMALL;

                *p++ = cpu_to_be32(b->type);
                *p++ = cpu_to_be32(b->scsi.code_set);
                *p++ = cpu_to_be32(b->scsi.designator_type);
                p = xdr_encode_opaque(p, b->scsi.designator, b->scsi.designator_len);
                p = xdr_encode_hyper(p, b->scsi.pr_key);
                break;
        default:
                return -ENOTSUPP;
        }

        return len;
}

__be32
nfsd4_block_encode_getdeviceinfo(struct xdr_stream *xdr,
                const struct nfsd4_getdeviceinfo *gdp)
{
        struct pnfs_block_deviceaddr *dev = gdp->gd_device;
        int len = sizeof(__be32), ret, i;
        __be32 *p;

        /*
         * See paragraph 5 of RFC 8881 S18.40.3.
         */
        if (!gdp->gd_maxcount) {
                if (xdr_stream_encode_u32(xdr, 0) != XDR_UNIT)
                        return nfserr_resource;
                return nfs_ok;
        }

        p = xdr_reserve_space(xdr, len + sizeof(__be32));
        if (!p)
                return nfserr_resource;

        for (i = 0; i < dev->nr_volumes; i++) {
                ret = nfsd4_block_encode_volume(xdr, &dev->volumes[i]);
                if (ret < 0)
                        return nfserrno(ret);
                len += ret;
        }

        /*
         * Fill in the overall length and number of volumes at the beginning
         * of the layout.
         */
        *p++ = cpu_to_be32(len);
        *p++ = cpu_to_be32(dev->nr_volumes);
        return 0;
}

/**
 * nfsd4_block_decode_layoutupdate - decode the block layout extent array
 * @xdr: subbuf set to the encoded array
 * @iomapp: pointer to store the decoded extent array
 * @nr_iomapsp: pointer to store the number of extents
 * @block_size: alignment of extent offset and length
 *
 * This function decodes the opaque field of the layoutupdate4 structure
 * in a layoutcommit request for the block layout driver. The field is
 * actually an array of extents sent by the client. It also checks that
 * the file offset, storage offset and length of each extent are aligned
 * by @block_size.
 *
 * Return values:
 *   %nfs_ok: Successful decoding, @iomapp and @nr_iomapsp are valid
 *   %nfserr_bad_xdr: The encoded array in @xdr is invalid
 *   %nfserr_inval: An unaligned extent found
 *   %nfserr_delay: Failed to allocate memory for @iomapp
 */
__be32
nfsd4_block_decode_layoutupdate(struct xdr_stream *xdr, struct iomap **iomapp,
                int *nr_iomapsp, u32 block_size)
{
        struct iomap *iomaps;
        u32 nr_iomaps, expected, len, i;
        __be32 nfserr;

        if (xdr_stream_decode_u32(xdr, &nr_iomaps))
                return nfserr_bad_xdr;

        len = sizeof(__be32) + xdr_stream_remaining(xdr);
        expected = sizeof(__be32) + nr_iomaps * PNFS_BLOCK_EXTENT_SIZE;
        if (len != expected)
                return nfserr_bad_xdr;

        iomaps = kzalloc_objs(*iomaps, nr_iomaps);
        if (!iomaps)
                return nfserr_delay;

        for (i = 0; i < nr_iomaps; i++) {
                struct pnfs_block_extent bex;

                if (nfsd4_decode_deviceid4(xdr, &bex.vol_id)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }

                if (xdr_stream_decode_u64(xdr, &bex.foff)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (bex.foff & (block_size - 1)) {
                        nfserr = nfserr_inval;
                        goto fail;
                }

                if (xdr_stream_decode_u64(xdr, &bex.len)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (bex.len & (block_size - 1)) {
                        nfserr = nfserr_inval;
                        goto fail;
                }

                if (xdr_stream_decode_u64(xdr, &bex.soff)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (bex.soff & (block_size - 1)) {
                        nfserr = nfserr_inval;
                        goto fail;
                }

                if (xdr_stream_decode_u32(xdr, &bex.es)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (bex.es != PNFS_BLOCK_READWRITE_DATA) {
                        nfserr = nfserr_inval;
                        goto fail;
                }

                iomaps[i].offset = bex.foff;
                iomaps[i].length = bex.len;
        }

        *iomapp = iomaps;
        *nr_iomapsp = nr_iomaps;
        return nfs_ok;
fail:
        kfree(iomaps);
        return nfserr;
}

/**
 * nfsd4_scsi_decode_layoutupdate - decode the scsi layout extent array
 * @xdr: subbuf set to the encoded array
 * @iomapp: pointer to store the decoded extent array
 * @nr_iomapsp: pointer to store the number of extents
 * @block_size: alignment of extent offset and length
 *
 * This function decodes the opaque field of the layoutupdate4 structure
 * in a layoutcommit request for the scsi layout driver. The field is
 * actually an array of extents sent by the client. It also checks that
 * the offset and length of each extent are aligned by @block_size.
 *
 * Return values:
 *   %nfs_ok: Successful decoding, @iomapp and @nr_iomapsp are valid
 *   %nfserr_bad_xdr: The encoded array in @xdr is invalid
 *   %nfserr_inval: An unaligned extent found
 *   %nfserr_delay: Failed to allocate memory for @iomapp
 */
__be32
nfsd4_scsi_decode_layoutupdate(struct xdr_stream *xdr, struct iomap **iomapp,
                int *nr_iomapsp, u32 block_size)
{
        struct iomap *iomaps;
        u32 nr_iomaps, expected, len, i;
        __be32 nfserr;

        if (xdr_stream_decode_u32(xdr, &nr_iomaps))
                return nfserr_bad_xdr;

        len = sizeof(__be32) + xdr_stream_remaining(xdr);
        expected = sizeof(__be32) + nr_iomaps * PNFS_SCSI_RANGE_SIZE;
        if (len != expected)
                return nfserr_bad_xdr;

        iomaps = kzalloc_objs(*iomaps, nr_iomaps);
        if (!iomaps)
                return nfserr_delay;

        for (i = 0; i < nr_iomaps; i++) {
                u64 val;

                if (xdr_stream_decode_u64(xdr, &val)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (val & (block_size - 1)) {
                        nfserr = nfserr_inval;
                        goto fail;
                }
                iomaps[i].offset = val;

                if (xdr_stream_decode_u64(xdr, &val)) {
                        nfserr = nfserr_bad_xdr;
                        goto fail;
                }
                if (val & (block_size - 1)) {
                        nfserr = nfserr_inval;
                        goto fail;
                }
                iomaps[i].length = val;
        }

        *iomapp = iomaps;
        *nr_iomapsp = nr_iomaps;
        return nfs_ok;
fail:
        kfree(iomaps);
        return nfserr;
}