net/sunrpc/xprtrdma/svc_rdma_marshal.c

   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  */
  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  */
  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  */
 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
 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
 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
 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
 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
 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
 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
 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
 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
 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 }