1/*
2 * Copyright (c) 2005-2006 Network Appliance, Inc. All rights reserved.
3 *
4 * This software is available to you under a choice of one of two
5 * licenses.  You may choose to be licensed under the terms of the GNU
6 * General Public License (GPL) Version 2, available from the file
7 * COPYING in the main directory of this source tree, or the BSD-type
8 * license below:
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 *
14 *      Redistributions of source code must retain the above copyright
15 *      notice, this list of conditions and the following disclaimer.
16 *
17 *      Redistributions in binary form must reproduce the above
18 *      copyright notice, this list of conditions and the following
19 *      disclaimer in the documentation and/or other materials provided
20 *      with the distribution.
21 *
22 *      Neither the name of the Network Appliance, Inc. nor the names of
23 *      its contributors may be used to endorse or promote products
24 *      derived from this software without specific prior written
25 *      permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
28 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
29 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
30 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
31 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
32 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
33 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
37 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
38 *
39 * Author: Tom Tucker <tom@opengridcomputing.com>
40 */
41
42#include <linux/sunrpc/xdr.h>
43#include <linux/sunrpc/debug.h>
44#include <asm/unaligned.h>
45#include <linux/sunrpc/rpc_rdma.h>
46#include <linux/sunrpc/svc_rdma.h>
47
48#define RPCDBG_FACILITY	RPCDBG_SVCXPRT
49
50/*
51 * Decodes a read chunk list. The expected format is as follows:
52 *    descrim  : xdr_one
53 *    position : u32 offset into XDR stream
54 *    handle   : u32 RKEY
55 *    . . .
56 *  end-of-list: xdr_zero
57 */
58static u32 *decode_read_list(u32 *va, u32 *vaend)
59{
60	struct rpcrdma_read_chunk *ch = (struct rpcrdma_read_chunk *)va;
61
62	while (ch->rc_discrim != xdr_zero) {
63		if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
64		    (unsigned long)vaend) {
65			dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
66			return NULL;
67		}
68		ch++;
69	}
70	return (u32 *)&ch->rc_position;
71}
72
73/*
74 * Decodes a write chunk list. The expected format is as follows:
75 *    descrim  : xdr_one
76 *    nchunks  : <count>
77 *       handle   : u32 RKEY              ---+
78 *       length   : u32 <len of segment>     |
79 *       offset   : remove va                + <count>
80 *       . . .                               |
81 *                                        ---+
82 */
83static u32 *decode_write_list(u32 *va, u32 *vaend)
84{
85	unsigned long start, end;
86	int nchunks;
87
88	struct rpcrdma_write_array *ary =
89		(struct rpcrdma_write_array *)va;
90
91	/* Check for not write-array */
92	if (ary->wc_discrim == xdr_zero)
93		return (u32 *)&ary->wc_nchunks;
94
95	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
96	    (unsigned long)vaend) {
97		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
98		return NULL;
99	}
100	nchunks = ntohl(ary->wc_nchunks);
101
102	start = (unsigned long)&ary->wc_array[0];
103	end = (unsigned long)vaend;
104	if (nchunks < 0 ||
105	    nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
106	    (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
107		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
108			ary, nchunks, vaend);
109		return NULL;
110	}
111	/*
112	 * rs_length is the 2nd 4B field in wc_target and taking its
113	 * address skips the list terminator
114	 */
115	return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
116}
117
118static u32 *decode_reply_array(u32 *va, u32 *vaend)
119{
120	unsigned long start, end;
121	int nchunks;
122	struct rpcrdma_write_array *ary =
123		(struct rpcrdma_write_array *)va;
124
125	/* Check for no reply-array */
126	if (ary->wc_discrim == xdr_zero)
127		return (u32 *)&ary->wc_nchunks;
128
129	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
130	    (unsigned long)vaend) {
131		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
132		return NULL;
133	}
134	nchunks = ntohl(ary->wc_nchunks);
135
136	start = (unsigned long)&ary->wc_array[0];
137	end = (unsigned long)vaend;
138	if (nchunks < 0 ||
139	    nchunks > (SIZE_MAX - start) / sizeof(struct rpcrdma_write_chunk) ||
140	    (start + (sizeof(struct rpcrdma_write_chunk) * nchunks)) > end) {
141		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
142			ary, nchunks, vaend);
143		return NULL;
144	}
145	return (u32 *)&ary->wc_array[nchunks];
146}
147
148int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
149			    struct svc_rqst *rqstp)
150{
151	struct rpcrdma_msg *rmsgp = NULL;
152	u32 *va;
153	u32 *vaend;
154	u32 hdr_len;
155
156	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
157
158	/* Verify that there's enough bytes for header + something */
159	if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
160		dprintk("svcrdma: header too short = %d\n",
161			rqstp->rq_arg.len);
162		return -EINVAL;
163	}
164
165	/* Decode the header */
166	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
167	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
168	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
169	rmsgp->rm_type = ntohl(rmsgp->rm_type);
170
171	if (rmsgp->rm_vers != RPCRDMA_VERSION)
172		return -ENOSYS;
173
174	/* Pull in the extra for the padded case and bump our pointer */
175	if (rmsgp->rm_type == RDMA_MSGP) {
176		int hdrlen;
177		rmsgp->rm_body.rm_padded.rm_align =
178			ntohl(rmsgp->rm_body.rm_padded.rm_align);
179		rmsgp->rm_body.rm_padded.rm_thresh =
180			ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
181
182		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
183		rqstp->rq_arg.head[0].iov_base = va;
184		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
185		rqstp->rq_arg.head[0].iov_len -= hdrlen;
186		if (hdrlen > rqstp->rq_arg.len)
187			return -EINVAL;
188		return hdrlen;
189	}
190
191	/* The chunk list may contain either a read chunk list or a write
192	 * chunk list and a reply chunk list.
193	 */
194	va = &rmsgp->rm_body.rm_chunks[0];
195	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
196	va = decode_read_list(va, vaend);
197	if (!va)
198		return -EINVAL;
199	va = decode_write_list(va, vaend);
200	if (!va)
201		return -EINVAL;
202	va = decode_reply_array(va, vaend);
203	if (!va)
204		return -EINVAL;
205
206	rqstp->rq_arg.head[0].iov_base = va;
207	hdr_len = (unsigned long)va - (unsigned long)rmsgp;
208	rqstp->rq_arg.head[0].iov_len -= hdr_len;
209
210	*rdma_req = rmsgp;
211	return hdr_len;
212}
213
214int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
215{
216	struct rpcrdma_msg *rmsgp = NULL;
217	struct rpcrdma_read_chunk *ch;
218	struct rpcrdma_write_array *ary;
219	u32 *va;
220	u32 hdrlen;
221
222	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
223		rqstp);
224	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
225
226	/* Pull in the extra for the padded case and bump our pointer */
227	if (rmsgp->rm_type == RDMA_MSGP) {
228		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
229		rqstp->rq_arg.head[0].iov_base = va;
230		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
231		rqstp->rq_arg.head[0].iov_len -= hdrlen;
232		return hdrlen;
233	}
234
235	/*
236	 * Skip all chunks to find RPC msg. These were previously processed
237	 */
238	va = &rmsgp->rm_body.rm_chunks[0];
239
240	/* Skip read-list */
241	for (ch = (struct rpcrdma_read_chunk *)va;
242	     ch->rc_discrim != xdr_zero; ch++);
243	va = (u32 *)&ch->rc_position;
244
245	/* Skip write-list */
246	ary = (struct rpcrdma_write_array *)va;
247	if (ary->wc_discrim == xdr_zero)
248		va = (u32 *)&ary->wc_nchunks;
249	else
250		/*
251		 * rs_length is the 2nd 4B field in wc_target and taking its
252		 * address skips the list terminator
253		 */
254		va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
255
256	/* Skip reply-array */
257	ary = (struct rpcrdma_write_array *)va;
258	if (ary->wc_discrim == xdr_zero)
259		va = (u32 *)&ary->wc_nchunks;
260	else
261		va = (u32 *)&ary->wc_array[ary->wc_nchunks];
262
263	rqstp->rq_arg.head[0].iov_base = va;
264	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
265	rqstp->rq_arg.head[0].iov_len -= hdrlen;
266
267	return hdrlen;
268}
269
270int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
271			      struct rpcrdma_msg *rmsgp,
272			      enum rpcrdma_errcode err, u32 *va)
273{
274	u32 *startp = va;
275
276	*va++ = htonl(rmsgp->rm_xid);
277	*va++ = htonl(rmsgp->rm_vers);
278	*va++ = htonl(xprt->sc_max_requests);
279	*va++ = htonl(RDMA_ERROR);
280	*va++ = htonl(err);
281	if (err == ERR_VERS) {
282		*va++ = htonl(RPCRDMA_VERSION);
283		*va++ = htonl(RPCRDMA_VERSION);
284	}
285
286	return (int)((unsigned long)va - (unsigned long)startp);
287}
288
289int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
290{
291	struct rpcrdma_write_array *wr_ary;
292
293	/* There is no read-list in a reply */
294
295	/* skip write list */
296	wr_ary = (struct rpcrdma_write_array *)
297		&rmsgp->rm_body.rm_chunks[1];
298	if (wr_ary->wc_discrim)
299		wr_ary = (struct rpcrdma_write_array *)
300			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
301			wc_target.rs_length;
302	else
303		wr_ary = (struct rpcrdma_write_array *)
304			&wr_ary->wc_nchunks;
305
306	/* skip reply array */
307	if (wr_ary->wc_discrim)
308		wr_ary = (struct rpcrdma_write_array *)
309			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
310	else
311		wr_ary = (struct rpcrdma_write_array *)
312			&wr_ary->wc_nchunks;
313
314	return (unsigned long) wr_ary - (unsigned long) rmsgp;
315}
316
317void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
318{
319	struct rpcrdma_write_array *ary;
320
321	/* no read-list */
322	rmsgp->rm_body.rm_chunks[0] = xdr_zero;
323
324	/* write-array discrim */
325	ary = (struct rpcrdma_write_array *)
326		&rmsgp->rm_body.rm_chunks[1];
327	ary->wc_discrim = xdr_one;
328	ary->wc_nchunks = htonl(chunks);
329
330	/* write-list terminator */
331	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
332
333	/* reply-array discriminator */
334	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
335}
336
337void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
338				 int chunks)
339{
340	ary->wc_discrim = xdr_one;
341	ary->wc_nchunks = htonl(chunks);
342}
343
344void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
345				     int chunk_no,
346				     __be32 rs_handle,
347				     __be64 rs_offset,
348				     u32 write_len)
349{
350	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
351	seg->rs_handle = rs_handle;
352	seg->rs_offset = rs_offset;
353	seg->rs_length = htonl(write_len);
354}
355
356void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
357				  struct rpcrdma_msg *rdma_argp,
358				  struct rpcrdma_msg *rdma_resp,
359				  enum rpcrdma_proc rdma_type)
360{
361	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
362	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
363	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
364	rdma_resp->rm_type = htonl(rdma_type);
365
366	/* Encode <nul> chunks lists */
367	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
368	rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
369	rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
370}
371