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  */
decode_read_list(u32 * va,u32 * vaend)58 static 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 		u64 ch_offset;
64 
65 		if (((unsigned long)ch + sizeof(struct rpcrdma_read_chunk)) >
66 		    (unsigned long)vaend) {
67 			dprintk("svcrdma: vaend=%p, ch=%p\n", vaend, ch);
68 			return NULL;
69 		}
70 
71 		ch->rc_discrim = ntohl(ch->rc_discrim);
72 		ch->rc_position = ntohl(ch->rc_position);
73 		ch->rc_target.rs_handle = ntohl(ch->rc_target.rs_handle);
74 		ch->rc_target.rs_length = ntohl(ch->rc_target.rs_length);
75 		va = (u32 *)&ch->rc_target.rs_offset;
76 		xdr_decode_hyper(va, &ch_offset);
77 		put_unaligned(ch_offset, (u64 *)va);
78 		ch++;
79 	}
80 	return (u32 *)&ch->rc_position;
81 }
82 
83 /*
84  * Determine number of chunks and total bytes in chunk list. The chunk
85  * list has already been verified to fit within the RPCRDMA header.
86  */
svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk * ch,int * ch_count,int * byte_count)87 void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
88 			       int *ch_count, int *byte_count)
89 {
90 	/* compute the number of bytes represented by read chunks */
91 	*byte_count = 0;
92 	*ch_count = 0;
93 	for (; ch->rc_discrim != 0; ch++) {
94 		*byte_count = *byte_count + ch->rc_target.rs_length;
95 		*ch_count = *ch_count + 1;
96 	}
97 }
98 
99 /*
100  * Decodes a write chunk list. The expected format is as follows:
101  *    descrim  : xdr_one
102  *    nchunks  : <count>
103  *       handle   : u32 RKEY              ---+
104  *       length   : u32 <len of segment>     |
105  *       offset   : remove va                + <count>
106  *       . . .                               |
107  *                                        ---+
108  */
decode_write_list(u32 * va,u32 * vaend)109 static u32 *decode_write_list(u32 *va, u32 *vaend)
110 {
111 	int ch_no;
112 	struct rpcrdma_write_array *ary =
113 		(struct rpcrdma_write_array *)va;
114 
115 	/* Check for not write-array */
116 	if (ary->wc_discrim == xdr_zero)
117 		return (u32 *)&ary->wc_nchunks;
118 
119 	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
120 	    (unsigned long)vaend) {
121 		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
122 		return NULL;
123 	}
124 	ary->wc_discrim = ntohl(ary->wc_discrim);
125 	ary->wc_nchunks = ntohl(ary->wc_nchunks);
126 	if (((unsigned long)&ary->wc_array[0] +
127 	     (sizeof(struct rpcrdma_write_chunk) * ary->wc_nchunks)) >
128 	    (unsigned long)vaend) {
129 		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
130 			ary, ary->wc_nchunks, vaend);
131 		return NULL;
132 	}
133 	for (ch_no = 0; ch_no < ary->wc_nchunks; ch_no++) {
134 		u64 ch_offset;
135 
136 		ary->wc_array[ch_no].wc_target.rs_handle =
137 			ntohl(ary->wc_array[ch_no].wc_target.rs_handle);
138 		ary->wc_array[ch_no].wc_target.rs_length =
139 			ntohl(ary->wc_array[ch_no].wc_target.rs_length);
140 		va = (u32 *)&ary->wc_array[ch_no].wc_target.rs_offset;
141 		xdr_decode_hyper(va, &ch_offset);
142 		put_unaligned(ch_offset, (u64 *)va);
143 	}
144 
145 	/*
146 	 * rs_length is the 2nd 4B field in wc_target and taking its
147 	 * address skips the list terminator
148 	 */
149 	return (u32 *)&ary->wc_array[ch_no].wc_target.rs_length;
150 }
151 
decode_reply_array(u32 * va,u32 * vaend)152 static u32 *decode_reply_array(u32 *va, u32 *vaend)
153 {
154 	int ch_no;
155 	struct rpcrdma_write_array *ary =
156 		(struct rpcrdma_write_array *)va;
157 
158 	/* Check for no reply-array */
159 	if (ary->wc_discrim == xdr_zero)
160 		return (u32 *)&ary->wc_nchunks;
161 
162 	if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
163 	    (unsigned long)vaend) {
164 		dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
165 		return NULL;
166 	}
167 	ary->wc_discrim = ntohl(ary->wc_discrim);
168 	ary->wc_nchunks = ntohl(ary->wc_nchunks);
169 	if (((unsigned long)&ary->wc_array[0] +
170 	     (sizeof(struct rpcrdma_write_chunk) * ary->wc_nchunks)) >
171 	    (unsigned long)vaend) {
172 		dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
173 			ary, ary->wc_nchunks, vaend);
174 		return NULL;
175 	}
176 	for (ch_no = 0; ch_no < ary->wc_nchunks; ch_no++) {
177 		u64 ch_offset;
178 
179 		ary->wc_array[ch_no].wc_target.rs_handle =
180 			ntohl(ary->wc_array[ch_no].wc_target.rs_handle);
181 		ary->wc_array[ch_no].wc_target.rs_length =
182 			ntohl(ary->wc_array[ch_no].wc_target.rs_length);
183 		va = (u32 *)&ary->wc_array[ch_no].wc_target.rs_offset;
184 		xdr_decode_hyper(va, &ch_offset);
185 		put_unaligned(ch_offset, (u64 *)va);
186 	}
187 
188 	return (u32 *)&ary->wc_array[ch_no];
189 }
190 
svc_rdma_xdr_decode_req(struct rpcrdma_msg ** rdma_req,struct svc_rqst * rqstp)191 int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
192 			    struct svc_rqst *rqstp)
193 {
194 	struct rpcrdma_msg *rmsgp = NULL;
195 	u32 *va;
196 	u32 *vaend;
197 	u32 hdr_len;
198 
199 	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
200 
201 	/* Verify that there's enough bytes for header + something */
202 	if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
203 		dprintk("svcrdma: header too short = %d\n",
204 			rqstp->rq_arg.len);
205 		return -EINVAL;
206 	}
207 
208 	/* Decode the header */
209 	rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
210 	rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
211 	rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
212 	rmsgp->rm_type = ntohl(rmsgp->rm_type);
213 
214 	if (rmsgp->rm_vers != RPCRDMA_VERSION)
215 		return -ENOSYS;
216 
217 	/* Pull in the extra for the padded case and bump our pointer */
218 	if (rmsgp->rm_type == RDMA_MSGP) {
219 		int hdrlen;
220 		rmsgp->rm_body.rm_padded.rm_align =
221 			ntohl(rmsgp->rm_body.rm_padded.rm_align);
222 		rmsgp->rm_body.rm_padded.rm_thresh =
223 			ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
224 
225 		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
226 		rqstp->rq_arg.head[0].iov_base = va;
227 		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
228 		rqstp->rq_arg.head[0].iov_len -= hdrlen;
229 		if (hdrlen > rqstp->rq_arg.len)
230 			return -EINVAL;
231 		return hdrlen;
232 	}
233 
234 	/* The chunk list may contain either a read chunk list or a write
235 	 * chunk list and a reply chunk list.
236 	 */
237 	va = &rmsgp->rm_body.rm_chunks[0];
238 	vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
239 	va = decode_read_list(va, vaend);
240 	if (!va)
241 		return -EINVAL;
242 	va = decode_write_list(va, vaend);
243 	if (!va)
244 		return -EINVAL;
245 	va = decode_reply_array(va, vaend);
246 	if (!va)
247 		return -EINVAL;
248 
249 	rqstp->rq_arg.head[0].iov_base = va;
250 	hdr_len = (unsigned long)va - (unsigned long)rmsgp;
251 	rqstp->rq_arg.head[0].iov_len -= hdr_len;
252 
253 	*rdma_req = rmsgp;
254 	return hdr_len;
255 }
256 
svc_rdma_xdr_decode_deferred_req(struct svc_rqst * rqstp)257 int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
258 {
259 	struct rpcrdma_msg *rmsgp = NULL;
260 	struct rpcrdma_read_chunk *ch;
261 	struct rpcrdma_write_array *ary;
262 	u32 *va;
263 	u32 hdrlen;
264 
265 	dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
266 		rqstp);
267 	rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
268 
269 	/* Pull in the extra for the padded case and bump our pointer */
270 	if (rmsgp->rm_type == RDMA_MSGP) {
271 		va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
272 		rqstp->rq_arg.head[0].iov_base = va;
273 		hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
274 		rqstp->rq_arg.head[0].iov_len -= hdrlen;
275 		return hdrlen;
276 	}
277 
278 	/*
279 	 * Skip all chunks to find RPC msg. These were previously processed
280 	 */
281 	va = &rmsgp->rm_body.rm_chunks[0];
282 
283 	/* Skip read-list */
284 	for (ch = (struct rpcrdma_read_chunk *)va;
285 	     ch->rc_discrim != xdr_zero; ch++);
286 	va = (u32 *)&ch->rc_position;
287 
288 	/* Skip write-list */
289 	ary = (struct rpcrdma_write_array *)va;
290 	if (ary->wc_discrim == xdr_zero)
291 		va = (u32 *)&ary->wc_nchunks;
292 	else
293 		/*
294 		 * rs_length is the 2nd 4B field in wc_target and taking its
295 		 * address skips the list terminator
296 		 */
297 		va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
298 
299 	/* Skip reply-array */
300 	ary = (struct rpcrdma_write_array *)va;
301 	if (ary->wc_discrim == xdr_zero)
302 		va = (u32 *)&ary->wc_nchunks;
303 	else
304 		va = (u32 *)&ary->wc_array[ary->wc_nchunks];
305 
306 	rqstp->rq_arg.head[0].iov_base = va;
307 	hdrlen = (unsigned long)va - (unsigned long)rmsgp;
308 	rqstp->rq_arg.head[0].iov_len -= hdrlen;
309 
310 	return hdrlen;
311 }
312 
svc_rdma_xdr_encode_error(struct svcxprt_rdma * xprt,struct rpcrdma_msg * rmsgp,enum rpcrdma_errcode err,u32 * va)313 int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
314 			      struct rpcrdma_msg *rmsgp,
315 			      enum rpcrdma_errcode err, u32 *va)
316 {
317 	u32 *startp = va;
318 
319 	*va++ = htonl(rmsgp->rm_xid);
320 	*va++ = htonl(rmsgp->rm_vers);
321 	*va++ = htonl(xprt->sc_max_requests);
322 	*va++ = htonl(RDMA_ERROR);
323 	*va++ = htonl(err);
324 	if (err == ERR_VERS) {
325 		*va++ = htonl(RPCRDMA_VERSION);
326 		*va++ = htonl(RPCRDMA_VERSION);
327 	}
328 
329 	return (int)((unsigned long)va - (unsigned long)startp);
330 }
331 
svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg * rmsgp)332 int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
333 {
334 	struct rpcrdma_write_array *wr_ary;
335 
336 	/* There is no read-list in a reply */
337 
338 	/* skip write list */
339 	wr_ary = (struct rpcrdma_write_array *)
340 		&rmsgp->rm_body.rm_chunks[1];
341 	if (wr_ary->wc_discrim)
342 		wr_ary = (struct rpcrdma_write_array *)
343 			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
344 			wc_target.rs_length;
345 	else
346 		wr_ary = (struct rpcrdma_write_array *)
347 			&wr_ary->wc_nchunks;
348 
349 	/* skip reply array */
350 	if (wr_ary->wc_discrim)
351 		wr_ary = (struct rpcrdma_write_array *)
352 			&wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
353 	else
354 		wr_ary = (struct rpcrdma_write_array *)
355 			&wr_ary->wc_nchunks;
356 
357 	return (unsigned long) wr_ary - (unsigned long) rmsgp;
358 }
359 
svc_rdma_xdr_encode_write_list(struct rpcrdma_msg * rmsgp,int chunks)360 void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
361 {
362 	struct rpcrdma_write_array *ary;
363 
364 	/* no read-list */
365 	rmsgp->rm_body.rm_chunks[0] = xdr_zero;
366 
367 	/* write-array discrim */
368 	ary = (struct rpcrdma_write_array *)
369 		&rmsgp->rm_body.rm_chunks[1];
370 	ary->wc_discrim = xdr_one;
371 	ary->wc_nchunks = htonl(chunks);
372 
373 	/* write-list terminator */
374 	ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
375 
376 	/* reply-array discriminator */
377 	ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
378 }
379 
svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array * ary,int chunks)380 void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
381 				 int chunks)
382 {
383 	ary->wc_discrim = xdr_one;
384 	ary->wc_nchunks = htonl(chunks);
385 }
386 
svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array * ary,int chunk_no,u32 rs_handle,u64 rs_offset,u32 write_len)387 void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
388 				     int chunk_no,
389 				     u32 rs_handle, u64 rs_offset,
390 				     u32 write_len)
391 {
392 	struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
393 	seg->rs_handle = htonl(rs_handle);
394 	seg->rs_length = htonl(write_len);
395 	xdr_encode_hyper((u32 *) &seg->rs_offset, rs_offset);
396 }
397 
svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma * xprt,struct rpcrdma_msg * rdma_argp,struct rpcrdma_msg * rdma_resp,enum rpcrdma_proc rdma_type)398 void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
399 				  struct rpcrdma_msg *rdma_argp,
400 				  struct rpcrdma_msg *rdma_resp,
401 				  enum rpcrdma_proc rdma_type)
402 {
403 	rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
404 	rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
405 	rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
406 	rdma_resp->rm_type = htonl(rdma_type);
407 
408 	/* Encode <nul> chunks lists */
409 	rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
410 	rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
411 	rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
412 }
413