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                 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  * Determine number of chunks and total bytes in chunk list. The chunk
  75  * list has already been verified to fit within the RPCRDMA header.
  76  */
  77 void svc_rdma_rcl_chunk_counts(struct rpcrdma_read_chunk *ch,
  78                                int *ch_count, int *byte_count)
  79 {
  80         /* compute the number of bytes represented by read chunks */
  81         *byte_count = 0;
  82         *ch_count = 0;
  83         for (; ch->rc_discrim != 0; ch++) {
  84                 *byte_count = *byte_count + ntohl(ch->rc_target.rs_length);
  85                 *ch_count = *ch_count + 1;
  86         }
  87 }
  88
  89 /*
  90  * Decodes a write chunk list. The expected format is as follows:
  91  *    descrim  : xdr_one
  92  *    nchunks  : <count>
  93  *       handle   : u32 RKEY              ---+
  94  *       length   : u32 <len of segment>     |
  95  *       offset   : remove va                + <count>
  96  *       . . .                               |
  97  *                                        ---+
  98  */
  99 static u32 *decode_write_list(u32 *va, u32 *vaend)
 100 {
 101         int nchunks;
 102
 103         struct rpcrdma_write_array *ary =
 104                 (struct rpcrdma_write_array *)va;
 105
 106         /* Check for not write-array */
 107         if (ary->wc_discrim == xdr_zero)
 108                 return (u32 *)&ary->wc_nchunks;
 109
 110         if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
 111             (unsigned long)vaend) {
 112                 dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
 113                 return NULL;
 114         }
 115         nchunks = ntohl(ary->wc_nchunks);
 116         if (((unsigned long)&ary->wc_array[0] +
 117              (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
 118             (unsigned long)vaend) {
 119                 dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
 120                         ary, nchunks, vaend);
 121                 return NULL;
 122         }
 123         /*
 124          * rs_length is the 2nd 4B field in wc_target and taking its
 125          * address skips the list terminator
 126          */
 127         return (u32 *)&ary->wc_array[nchunks].wc_target.rs_length;
 128 }
 129
 130 static u32 *decode_reply_array(u32 *va, u32 *vaend)
 131 {
 132         int nchunks;
 133         struct rpcrdma_write_array *ary =
 134                 (struct rpcrdma_write_array *)va;
 135
 136         /* Check for no reply-array */
 137         if (ary->wc_discrim == xdr_zero)
 138                 return (u32 *)&ary->wc_nchunks;
 139
 140         if ((unsigned long)ary + sizeof(struct rpcrdma_write_array) >
 141             (unsigned long)vaend) {
 142                 dprintk("svcrdma: ary=%p, vaend=%p\n", ary, vaend);
 143                 return NULL;
 144         }
 145         nchunks = ntohl(ary->wc_nchunks);
 146         if (((unsigned long)&ary->wc_array[0] +
 147              (sizeof(struct rpcrdma_write_chunk) * nchunks)) >
 148             (unsigned long)vaend) {
 149                 dprintk("svcrdma: ary=%p, wc_nchunks=%d, vaend=%p\n",
 150                         ary, nchunks, vaend);
 151                 return NULL;
 152         }
 153         return (u32 *)&ary->wc_array[nchunks];
 154 }
 155
 156 int svc_rdma_xdr_decode_req(struct rpcrdma_msg **rdma_req,
 157                             struct svc_rqst *rqstp)
 158 {
 159         struct rpcrdma_msg *rmsgp = NULL;
 160         u32 *va;
 161         u32 *vaend;
 162         u32 hdr_len;
 163
 164         rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
 165
 166         /* Verify that there's enough bytes for header + something */
 167         if (rqstp->rq_arg.len <= RPCRDMA_HDRLEN_MIN) {
 168                 dprintk("svcrdma: header too short = %d\n",
 169                         rqstp->rq_arg.len);
 170                 return -EINVAL;
 171         }
 172
 173         /* Decode the header */
 174         rmsgp->rm_xid = ntohl(rmsgp->rm_xid);
 175         rmsgp->rm_vers = ntohl(rmsgp->rm_vers);
 176         rmsgp->rm_credit = ntohl(rmsgp->rm_credit);
 177         rmsgp->rm_type = ntohl(rmsgp->rm_type);
 178
 179         if (rmsgp->rm_vers != RPCRDMA_VERSION)
 180                 return -ENOSYS;
 181
 182         /* Pull in the extra for the padded case and bump our pointer */
 183         if (rmsgp->rm_type == RDMA_MSGP) {
 184                 int hdrlen;
 185                 rmsgp->rm_body.rm_padded.rm_align =
 186                         ntohl(rmsgp->rm_body.rm_padded.rm_align);
 187                 rmsgp->rm_body.rm_padded.rm_thresh =
 188                         ntohl(rmsgp->rm_body.rm_padded.rm_thresh);
 189
 190                 va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
 191                 rqstp->rq_arg.head[0].iov_base = va;
 192                 hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
 193                 rqstp->rq_arg.head[0].iov_len -= hdrlen;
 194                 if (hdrlen > rqstp->rq_arg.len)
 195                         return -EINVAL;
 196                 return hdrlen;
 197         }
 198
 199         /* The chunk list may contain either a read chunk list or a write
 200          * chunk list and a reply chunk list.
 201          */
 202         va = &rmsgp->rm_body.rm_chunks[0];
 203         vaend = (u32 *)((unsigned long)rmsgp + rqstp->rq_arg.len);
 204         va = decode_read_list(va, vaend);
 205         if (!va)
 206                 return -EINVAL;
 207         va = decode_write_list(va, vaend);
 208         if (!va)
 209                 return -EINVAL;
 210         va = decode_reply_array(va, vaend);
 211         if (!va)
 212                 return -EINVAL;
 213
 214         rqstp->rq_arg.head[0].iov_base = va;
 215         hdr_len = (unsigned long)va - (unsigned long)rmsgp;
 216         rqstp->rq_arg.head[0].iov_len -= hdr_len;
 217
 218         *rdma_req = rmsgp;
 219         return hdr_len;
 220 }
 221
 222 int svc_rdma_xdr_decode_deferred_req(struct svc_rqst *rqstp)
 223 {
 224         struct rpcrdma_msg *rmsgp = NULL;
 225         struct rpcrdma_read_chunk *ch;
 226         struct rpcrdma_write_array *ary;
 227         u32 *va;
 228         u32 hdrlen;
 229
 230         dprintk("svcrdma: processing deferred RDMA header on rqstp=%p\n",
 231                 rqstp);
 232         rmsgp = (struct rpcrdma_msg *)rqstp->rq_arg.head[0].iov_base;
 233
 234         /* Pull in the extra for the padded case and bump our pointer */
 235         if (rmsgp->rm_type == RDMA_MSGP) {
 236                 va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
 237                 rqstp->rq_arg.head[0].iov_base = va;
 238                 hdrlen = (u32)((unsigned long)va - (unsigned long)rmsgp);
 239                 rqstp->rq_arg.head[0].iov_len -= hdrlen;
 240                 return hdrlen;
 241         }
 242
 243         /*
 244          * Skip all chunks to find RPC msg. These were previously processed
 245          */
 246         va = &rmsgp->rm_body.rm_chunks[0];
 247
 248         /* Skip read-list */
 249         for (ch = (struct rpcrdma_read_chunk *)va;
 250              ch->rc_discrim != xdr_zero; ch++);
 251         va = (u32 *)&ch->rc_position;
 252
 253         /* Skip write-list */
 254         ary = (struct rpcrdma_write_array *)va;
 255         if (ary->wc_discrim == xdr_zero)
 256                 va = (u32 *)&ary->wc_nchunks;
 257         else
 258                 /*
 259                  * rs_length is the 2nd 4B field in wc_target and taking its
 260                  * address skips the list terminator
 261                  */
 262                 va = (u32 *)&ary->wc_array[ary->wc_nchunks].wc_target.rs_length;
 263
 264         /* Skip reply-array */
 265         ary = (struct rpcrdma_write_array *)va;
 266         if (ary->wc_discrim == xdr_zero)
 267                 va = (u32 *)&ary->wc_nchunks;
 268         else
 269                 va = (u32 *)&ary->wc_array[ary->wc_nchunks];
 270
 271         rqstp->rq_arg.head[0].iov_base = va;
 272         hdrlen = (unsigned long)va - (unsigned long)rmsgp;
 273         rqstp->rq_arg.head[0].iov_len -= hdrlen;
 274
 275         return hdrlen;
 276 }
 277
 278 int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
 279                               struct rpcrdma_msg *rmsgp,
 280                               enum rpcrdma_errcode err, u32 *va)
 281 {
 282         u32 *startp = va;
 283
 284         *va++ = htonl(rmsgp->rm_xid);
 285         *va++ = htonl(rmsgp->rm_vers);
 286         *va++ = htonl(xprt->sc_max_requests);
 287         *va++ = htonl(RDMA_ERROR);
 288         *va++ = htonl(err);
 289         if (err == ERR_VERS) {
 290                 *va++ = htonl(RPCRDMA_VERSION);
 291                 *va++ = htonl(RPCRDMA_VERSION);
 292         }
 293
 294         return (int)((unsigned long)va - (unsigned long)startp);
 295 }
 296
 297 int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
 298 {
 299         struct rpcrdma_write_array *wr_ary;
 300
 301         /* There is no read-list in a reply */
 302
 303         /* skip write list */
 304         wr_ary = (struct rpcrdma_write_array *)
 305                 &rmsgp->rm_body.rm_chunks[1];
 306         if (wr_ary->wc_discrim)
 307                 wr_ary = (struct rpcrdma_write_array *)
 308                         &wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)].
 309                         wc_target.rs_length;
 310         else
 311                 wr_ary = (struct rpcrdma_write_array *)
 312                         &wr_ary->wc_nchunks;
 313
 314         /* skip reply array */
 315         if (wr_ary->wc_discrim)
 316                 wr_ary = (struct rpcrdma_write_array *)
 317                         &wr_ary->wc_array[ntohl(wr_ary->wc_nchunks)];
 318         else
 319                 wr_ary = (struct rpcrdma_write_array *)
 320                         &wr_ary->wc_nchunks;
 321
 322         return (unsigned long) wr_ary - (unsigned long) rmsgp;
 323 }
 324
 325 void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
 326 {
 327         struct rpcrdma_write_array *ary;
 328
 329         /* no read-list */
 330         rmsgp->rm_body.rm_chunks[0] = xdr_zero;
 331
 332         /* write-array discrim */
 333         ary = (struct rpcrdma_write_array *)
 334                 &rmsgp->rm_body.rm_chunks[1];
 335         ary->wc_discrim = xdr_one;
 336         ary->wc_nchunks = htonl(chunks);
 337
 338         /* write-list terminator */
 339         ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
 340
 341         /* reply-array discriminator */
 342         ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
 343 }
 344
 345 void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
 346                                  int chunks)
 347 {
 348         ary->wc_discrim = xdr_one;
 349         ary->wc_nchunks = htonl(chunks);
 350 }
 351
 352 void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
 353                                      int chunk_no,
 354                                      __be32 rs_handle,
 355                                      __be64 rs_offset,
 356                                      u32 write_len)
 357 {
 358         struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
 359         seg->rs_handle = rs_handle;
 360         seg->rs_offset = rs_offset;
 361         seg->rs_length = htonl(write_len);
 362 }
 363
 364 void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
 365                                   struct rpcrdma_msg *rdma_argp,
 366                                   struct rpcrdma_msg *rdma_resp,
 367                                   enum rpcrdma_proc rdma_type)
 368 {
 369         rdma_resp->rm_xid = htonl(rdma_argp->rm_xid);
 370         rdma_resp->rm_vers = htonl(rdma_argp->rm_vers);
 371         rdma_resp->rm_credit = htonl(xprt->sc_max_requests);
 372         rdma_resp->rm_type = htonl(rdma_type);
 373
 374         /* Encode <nul> chunks lists */
 375         rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
 376         rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
 377         rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
 378 }