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  * 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  */
  83 static 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
 118 static 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
 148 int 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
 214 int 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
 270 int 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
 289 int 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
 317 void 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
 337 void 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
 344 void 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
 356 void 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 }