net/sunrpc/xprtrdma/svc_rdma_marshal.c - linux - Git at Google

 /*
  * Copyright (c) 2016 Oracle. All rights reserved.
  * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
  *
  * This software is available to you under a choice of one of two
  * licenses.  You may choose to be licensed under the terms of the GNU
  * General Public License (GPL) Version 2, available from the file
  * COPYING in the main directory of this source tree, or the BSD-type
  * license below:
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *      Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *      Redistributions in binary form must reproduce the above
  *      copyright notice, this list of conditions and the following
  *      disclaimer in the documentation and/or other materials provided
  *      with the distribution.
  *
  *      Neither the name of the Network Appliance, Inc. nor the names of
  *      its contributors may be used to endorse or promote products
  *      derived from this software without specific prior written
  *      permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  * Author: Tom Tucker <tom@opengridcomputing.com>
  */

 #include <linux/sunrpc/xdr.h>
 #include <linux/sunrpc/debug.h>
 #include <asm/unaligned.h>
 #include <linux/sunrpc/rpc_rdma.h>
 #include <linux/sunrpc/svc_rdma.h>

 #define RPCDBG_FACILITY	RPCDBG_SVCXPRT

 static __be32 *xdr_check_read_list(__be32 *p, __be32 *end)
 {
 	__be32 *next;

 	while (*p++ != xdr_zero) {
 		next = p + rpcrdma_readchunk_maxsz - 1;
 		if (next > end)
 			return NULL;
 		p = next;
 	}
 	return p;
 }

 static __be32 *xdr_check_write_list(__be32 *p, __be32 *end)
 {
 	__be32 *next;

 	while (*p++ != xdr_zero) {
 		next = p + 1 + be32_to_cpup(p) * rpcrdma_segment_maxsz;
 		if (next > end)
 			return NULL;
 		p = next;
 	}
 	return p;
 }

 static __be32 *xdr_check_reply_chunk(__be32 *p, __be32 *end)
 {
 	__be32 *next;

 	if (*p++ != xdr_zero) {
 		next = p + 1 + be32_to_cpup(p) * rpcrdma_segment_maxsz;
 		if (next > end)
 			return NULL;
 		p = next;
 	}
 	return p;
 }

 /**
  * svc_rdma_xdr_decode_req - Parse incoming RPC-over-RDMA header
  * @rq_arg: Receive buffer
  *
  * On entry, xdr->head[0].iov_base points to first byte in the
  * RPC-over-RDMA header.
  *
  * On successful exit, head[0] points to first byte past the
  * RPC-over-RDMA header. For RDMA_MSG, this is the RPC message.
  * The length of the RPC-over-RDMA header is returned.
  */
 int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
 {
 	__be32 *p, *end, *rdma_argp;
 	unsigned int hdr_len;

 	/* Verify that there's enough bytes for header + something */
 	if (rq_arg->len <= RPCRDMA_HDRLEN_ERR)
 		goto out_short;

 	rdma_argp = rq_arg->head[0].iov_base;
 	if (*(rdma_argp + 1) != rpcrdma_version)
 		goto out_version;

 	switch (*(rdma_argp + 3)) {
 	case rdma_msg:
 	case rdma_nomsg:
 		break;

 	case rdma_done:
 		goto out_drop;

 	case rdma_error:
 		goto out_drop;

 	default:
 		goto out_proc;
 	}

 	end = (__be32 *)((unsigned long)rdma_argp + rq_arg->len);
 	p = xdr_check_read_list(rdma_argp + 4, end);
 	if (!p)
 		goto out_inval;
 	p = xdr_check_write_list(p, end);
 	if (!p)
 		goto out_inval;
 	p = xdr_check_reply_chunk(p, end);
 	if (!p)
 		goto out_inval;
 	if (p > end)
 		goto out_inval;

 	rq_arg->head[0].iov_base = p;
 	hdr_len = (unsigned long)p - (unsigned long)rdma_argp;
 	rq_arg->head[0].iov_len -= hdr_len;
 	return hdr_len;

 out_short:
 	dprintk("svcrdma: header too short = %d\n", rq_arg->len);
 	return -EINVAL;

 out_version:
 	dprintk("svcrdma: bad xprt version: %u\n",
 		be32_to_cpup(rdma_argp + 1));
 	return -EPROTONOSUPPORT;

 out_drop:
 	dprintk("svcrdma: dropping RDMA_DONE/ERROR message\n");
 	return 0;

 out_proc:
 	dprintk("svcrdma: bad rdma procedure (%u)\n",
 		be32_to_cpup(rdma_argp + 3));
 	return -EINVAL;

 out_inval:
 	dprintk("svcrdma: failed to parse transport header\n");
 	return -EINVAL;
 }

 int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
 			      struct rpcrdma_msg *rmsgp,
 			      enum rpcrdma_errcode err, __be32 *va)
 {
 	__be32 *startp = va;

 	*va++ = rmsgp->rm_xid;
 	*va++ = rmsgp->rm_vers;
 	*va++ = xprt->sc_fc_credits;
 	*va++ = rdma_error;
 	*va++ = cpu_to_be32(err);
 	if (err == ERR_VERS) {
 		*va++ = rpcrdma_version;
 		*va++ = rpcrdma_version;
 	}

 	return (int)((unsigned long)va - (unsigned long)startp);
 }

 /**
  * svc_rdma_xdr_get_reply_hdr_length - Get length of Reply transport header
  * @rdma_resp: buffer containing Reply transport header
  *
  * Returns length of transport header, in bytes.
  */
 unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp)
 {
 	unsigned int nsegs;
 	__be32 *p;

 	p = rdma_resp;

 	/* RPC-over-RDMA V1 replies never have a Read list. */
 	p += rpcrdma_fixed_maxsz + 1;

 	/* Skip Write list. */
 	while (*p++ != xdr_zero) {
 		nsegs = be32_to_cpup(p++);
 		p += nsegs * rpcrdma_segment_maxsz;
 	}

 	/* Skip Reply chunk. */
 	if (*p++ != xdr_zero) {
 		nsegs = be32_to_cpup(p++);
 		p += nsegs * rpcrdma_segment_maxsz;
 	}

 	return (unsigned long)p - (unsigned long)rdma_resp;
 }

 void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
 {
 	struct rpcrdma_write_array *ary;

 	/* no read-list */
 	rmsgp->rm_body.rm_chunks[0] = xdr_zero;

 	/* write-array discrim */
 	ary = (struct rpcrdma_write_array *)
 		&rmsgp->rm_body.rm_chunks[1];
 	ary->wc_discrim = xdr_one;
 	ary->wc_nchunks = cpu_to_be32(chunks);

 	/* write-list terminator */
 	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;

 	/* reply-array discriminator */
 	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
 }

 void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
 				 int chunks)
 {
 	ary->wc_discrim = xdr_one;
 	ary->wc_nchunks = cpu_to_be32(chunks);
 }

 void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
 				     int chunk_no,
 				     __be32 rs_handle,
 				     __be64 rs_offset,
 				     u32 write_len)
 {
 	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
 	seg->rs_handle = rs_handle;
 	seg->rs_offset = rs_offset;
 	seg->rs_length = cpu_to_be32(write_len);
 }
	/*
	* Copyright (c) 2016 Oracle. All rights reserved.
	* Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
	*
	* This software is available to you under a choice of one of two
	* licenses. You may choose to be licensed under the terms of the GNU
	* General Public License (GPL) Version 2, available from the file
	* COPYING in the main directory of this source tree, or the BSD-type
	* license below:
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that the following conditions
	* are met:
	*
	* Redistributions of source code must retain the above copyright
	* notice, this list of conditions and the following disclaimer.
	*
	* Redistributions in binary form must reproduce the above
	* copyright notice, this list of conditions and the following
	* disclaimer in the documentation and/or other materials provided
	* with the distribution.
	*
	* Neither the name of the Network Appliance, Inc. nor the names of
	* its contributors may be used to endorse or promote products
	* derived from this software without specific prior written
	* permission.
	*
	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	*
	* Author: Tom Tucker <tom@opengridcomputing.com>
	*/

	#include <linux/sunrpc/xdr.h>
	#include <linux/sunrpc/debug.h>
	#include <asm/unaligned.h>
	#include <linux/sunrpc/rpc_rdma.h>
	#include <linux/sunrpc/svc_rdma.h>

	#define RPCDBG_FACILITY RPCDBG_SVCXPRT

	static __be32 xdr_check_read_list(__be32 p, __be32 *end)
	{
	__be32 *next;

	while (*p++ != xdr_zero) {
	next = p + rpcrdma_readchunk_maxsz - 1;
	if (next > end)
	return NULL;
	p = next;
	}
	return p;
	}

	static __be32 xdr_check_write_list(__be32 p, __be32 *end)
	{
	__be32 *next;

	while (*p++ != xdr_zero) {
	next = p + 1 + be32_to_cpup(p) * rpcrdma_segment_maxsz;
	if (next > end)
	return NULL;
	p = next;
	}
	return p;
	}

	static __be32 xdr_check_reply_chunk(__be32 p, __be32 *end)
	{
	__be32 *next;

	if (*p++ != xdr_zero) {
	next = p + 1 + be32_to_cpup(p) * rpcrdma_segment_maxsz;
	if (next > end)
	return NULL;
	p = next;
	}
	return p;
	}

	/**
	* svc_rdma_xdr_decode_req - Parse incoming RPC-over-RDMA header
	* @rq_arg: Receive buffer
	*
	* On entry, xdr->head[0].iov_base points to first byte in the
	* RPC-over-RDMA header.
	*
	* On successful exit, head[0] points to first byte past the
	* RPC-over-RDMA header. For RDMA_MSG, this is the RPC message.
	* The length of the RPC-over-RDMA header is returned.
	*/
	int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
	{
	__be32 p, end, *rdma_argp;
	unsigned int hdr_len;

	/* Verify that there's enough bytes for header + something */
	if (rq_arg->len <= RPCRDMA_HDRLEN_ERR)
	goto out_short;

	rdma_argp = rq_arg->head[0].iov_base;
	if (*(rdma_argp + 1) != rpcrdma_version)
	goto out_version;

	switch (*(rdma_argp + 3)) {
	case rdma_msg:
	case rdma_nomsg:
	break;

	case rdma_done:
	goto out_drop;

	case rdma_error:
	goto out_drop;

	default:
	goto out_proc;
	}

	end = (__be32 *)((unsigned long)rdma_argp + rq_arg->len);
	p = xdr_check_read_list(rdma_argp + 4, end);
	if (!p)
	goto out_inval;
	p = xdr_check_write_list(p, end);
	if (!p)
	goto out_inval;
	p = xdr_check_reply_chunk(p, end);
	if (!p)
	goto out_inval;
	if (p > end)
	goto out_inval;

	rq_arg->head[0].iov_base = p;
	hdr_len = (unsigned long)p - (unsigned long)rdma_argp;
	rq_arg->head[0].iov_len -= hdr_len;
	return hdr_len;

	out_short:
	dprintk("svcrdma: header too short = %d\n", rq_arg->len);
	return -EINVAL;

	out_version:
	dprintk("svcrdma: bad xprt version: %u\n",
	be32_to_cpup(rdma_argp + 1));
	return -EPROTONOSUPPORT;

	out_drop:
	dprintk("svcrdma: dropping RDMA_DONE/ERROR message\n");
	return 0;

	out_proc:
	dprintk("svcrdma: bad rdma procedure (%u)\n",
	be32_to_cpup(rdma_argp + 3));
	return -EINVAL;

	out_inval:
	dprintk("svcrdma: failed to parse transport header\n");
	return -EINVAL;
	}

	int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
	struct rpcrdma_msg *rmsgp,
	enum rpcrdma_errcode err, __be32 *va)
	{
	__be32 *startp = va;

	*va++ = rmsgp->rm_xid;
	*va++ = rmsgp->rm_vers;
	*va++ = xprt->sc_fc_credits;
	*va++ = rdma_error;
	*va++ = cpu_to_be32(err);
	if (err == ERR_VERS) {
	*va++ = rpcrdma_version;
	*va++ = rpcrdma_version;
	}

	return (int)((unsigned long)va - (unsigned long)startp);
	}

	/**
	* svc_rdma_xdr_get_reply_hdr_length - Get length of Reply transport header
	* @rdma_resp: buffer containing Reply transport header
	*
	* Returns length of transport header, in bytes.
	*/
	unsigned int svc_rdma_xdr_get_reply_hdr_len(__be32 *rdma_resp)
	{
	unsigned int nsegs;
	__be32 *p;

	p = rdma_resp;

	/* RPC-over-RDMA V1 replies never have a Read list. */
	p += rpcrdma_fixed_maxsz + 1;

	/* Skip Write list. */
	while (*p++ != xdr_zero) {
	nsegs = be32_to_cpup(p++);
	p += nsegs * rpcrdma_segment_maxsz;
	}

	/* Skip Reply chunk. */
	if (*p++ != xdr_zero) {
	nsegs = be32_to_cpup(p++);
	p += nsegs * rpcrdma_segment_maxsz;
	}

	return (unsigned long)p - (unsigned long)rdma_resp;
	}

	void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
	{
	struct rpcrdma_write_array *ary;

	/* no read-list */
	rmsgp->rm_body.rm_chunks[0] = xdr_zero;

	/* write-array discrim */
	ary = (struct rpcrdma_write_array *)
	&rmsgp->rm_body.rm_chunks[1];
	ary->wc_discrim = xdr_one;
	ary->wc_nchunks = cpu_to_be32(chunks);

	/* write-list terminator */
	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;

	/* reply-array discriminator */
	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
	}

	void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
	int chunks)
	{
	ary->wc_discrim = xdr_one;
	ary->wc_nchunks = cpu_to_be32(chunks);
	}

	void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
	int chunk_no,
	__be32 rs_handle,
	__be64 rs_offset,
	u32 write_len)
	{
	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
	seg->rs_handle = rs_handle;
	seg->rs_offset = rs_offset;
	seg->rs_length = cpu_to_be32(write_len);
	}