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 : __be32 offset into XDR stream
  54  *    handle   : __be32 RKEY
  55  *    . . .
  56  *  end-of-list: xdr_zero
  57  */
  58 static __be32 *decode_read_list(__be32 *va, __be32 *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 &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   : __be32 RKEY           ---+
  78  *       length   : __be32 <len of segment>  |
  79  *       offset   : remove va                + <count>
  80  *       . . .                               |
  81  *                                        ---+
  82  */
  83 static __be32 *decode_write_list(__be32 *va, __be32 *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 &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 = be32_to_cpu(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 &ary->wc_array[nchunks].wc_target.rs_length;
 116 }
 117
 118 static __be32 *decode_reply_array(__be32 *va, __be32 *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 &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 = be32_to_cpu(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 (__be32 *)&ary->wc_array[nchunks];
 146 }
 147
 148 /**
 149  * svc_rdma_xdr_decode_req - Parse incoming RPC-over-RDMA header
 150  * @rq_arg: Receive buffer
 151  *
 152  * On entry, xdr->head[0].iov_base points to first byte in the
 153  * RPC-over-RDMA header.
 154  *
 155  * On successful exit, head[0] points to first byte past the
 156  * RPC-over-RDMA header. For RDMA_MSG, this is the RPC message.
 157  * The length of the RPC-over-RDMA header is returned.
 158  */
 159 int svc_rdma_xdr_decode_req(struct xdr_buf *rq_arg)
 160 {
 161         struct rpcrdma_msg *rmsgp;
 162         __be32 *va, *vaend;
 163         unsigned int len;
 164         u32 hdr_len;
 165
 166         /* Verify that there's enough bytes for header + something */
 167         if (rq_arg->len <= RPCRDMA_HDRLEN_ERR) {
 168                 dprintk("svcrdma: header too short = %d\n",
 169                         rq_arg->len);
 170                 return -EINVAL;
 171         }
 172
 173         rmsgp = (struct rpcrdma_msg *)rq_arg->head[0].iov_base;
 174         if (rmsgp->rm_vers != rpcrdma_version) {
 175                 dprintk("%s: bad version %u\n", __func__,
 176                         be32_to_cpu(rmsgp->rm_vers));
 177                 return -EPROTONOSUPPORT;
 178         }
 179
 180         switch (be32_to_cpu(rmsgp->rm_type)) {
 181         case RDMA_MSG:
 182         case RDMA_NOMSG:
 183                 break;
 184
 185         case RDMA_DONE:
 186                 /* Just drop it */
 187                 dprintk("svcrdma: dropping RDMA_DONE message\n");
 188                 return 0;
 189
 190         case RDMA_ERROR:
 191                 /* Possible if this is a backchannel reply.
 192                  * XXX: We should cancel this XID, though.
 193                  */
 194                 dprintk("svcrdma: dropping RDMA_ERROR message\n");
 195                 return 0;
 196
 197         case RDMA_MSGP:
 198                 /* Pull in the extra for the padded case, bump our pointer */
 199                 rmsgp->rm_body.rm_padded.rm_align =
 200                         be32_to_cpu(rmsgp->rm_body.rm_padded.rm_align);
 201                 rmsgp->rm_body.rm_padded.rm_thresh =
 202                         be32_to_cpu(rmsgp->rm_body.rm_padded.rm_thresh);
 203
 204                 va = &rmsgp->rm_body.rm_padded.rm_pempty[4];
 205                 rq_arg->head[0].iov_base = va;
 206                 len = (u32)((unsigned long)va - (unsigned long)rmsgp);
 207                 rq_arg->head[0].iov_len -= len;
 208                 if (len > rq_arg->len)
 209                         return -EINVAL;
 210                 return len;
 211         default:
 212                 dprintk("svcrdma: bad rdma procedure (%u)\n",
 213                         be32_to_cpu(rmsgp->rm_type));
 214                 return -EINVAL;
 215         }
 216
 217         /* The chunk list may contain either a read chunk list or a write
 218          * chunk list and a reply chunk list.
 219          */
 220         va = &rmsgp->rm_body.rm_chunks[0];
 221         vaend = (__be32 *)((unsigned long)rmsgp + rq_arg->len);
 222         va = decode_read_list(va, vaend);
 223         if (!va) {
 224                 dprintk("svcrdma: failed to decode read list\n");
 225                 return -EINVAL;
 226         }
 227         va = decode_write_list(va, vaend);
 228         if (!va) {
 229                 dprintk("svcrdma: failed to decode write list\n");
 230                 return -EINVAL;
 231         }
 232         va = decode_reply_array(va, vaend);
 233         if (!va) {
 234                 dprintk("svcrdma: failed to decode reply chunk\n");
 235                 return -EINVAL;
 236         }
 237
 238         rq_arg->head[0].iov_base = va;
 239         hdr_len = (unsigned long)va - (unsigned long)rmsgp;
 240         rq_arg->head[0].iov_len -= hdr_len;
 241         return hdr_len;
 242 }
 243
 244 int svc_rdma_xdr_encode_error(struct svcxprt_rdma *xprt,
 245                               struct rpcrdma_msg *rmsgp,
 246                               enum rpcrdma_errcode err, __be32 *va)
 247 {
 248         __be32 *startp = va;
 249
 250         *va++ = rmsgp->rm_xid;
 251         *va++ = rmsgp->rm_vers;
 252         *va++ = cpu_to_be32(xprt->sc_max_requests);
 253         *va++ = rdma_error;
 254         *va++ = cpu_to_be32(err);
 255         if (err == ERR_VERS) {
 256                 *va++ = rpcrdma_version;
 257                 *va++ = rpcrdma_version;
 258         }
 259
 260         return (int)((unsigned long)va - (unsigned long)startp);
 261 }
 262
 263 int svc_rdma_xdr_get_reply_hdr_len(struct rpcrdma_msg *rmsgp)
 264 {
 265         struct rpcrdma_write_array *wr_ary;
 266
 267         /* There is no read-list in a reply */
 268
 269         /* skip write list */
 270         wr_ary = (struct rpcrdma_write_array *)
 271                 &rmsgp->rm_body.rm_chunks[1];
 272         if (wr_ary->wc_discrim)
 273                 wr_ary = (struct rpcrdma_write_array *)
 274                         &wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)].
 275                         wc_target.rs_length;
 276         else
 277                 wr_ary = (struct rpcrdma_write_array *)
 278                         &wr_ary->wc_nchunks;
 279
 280         /* skip reply array */
 281         if (wr_ary->wc_discrim)
 282                 wr_ary = (struct rpcrdma_write_array *)
 283                         &wr_ary->wc_array[be32_to_cpu(wr_ary->wc_nchunks)];
 284         else
 285                 wr_ary = (struct rpcrdma_write_array *)
 286                         &wr_ary->wc_nchunks;
 287
 288         return (unsigned long) wr_ary - (unsigned long) rmsgp;
 289 }
 290
 291 void svc_rdma_xdr_encode_write_list(struct rpcrdma_msg *rmsgp, int chunks)
 292 {
 293         struct rpcrdma_write_array *ary;
 294
 295         /* no read-list */
 296         rmsgp->rm_body.rm_chunks[0] = xdr_zero;
 297
 298         /* write-array discrim */
 299         ary = (struct rpcrdma_write_array *)
 300                 &rmsgp->rm_body.rm_chunks[1];
 301         ary->wc_discrim = xdr_one;
 302         ary->wc_nchunks = cpu_to_be32(chunks);
 303
 304         /* write-list terminator */
 305         ary->wc_array[chunks].wc_target.rs_handle = xdr_zero;
 306
 307         /* reply-array discriminator */
 308         ary->wc_array[chunks].wc_target.rs_length = xdr_zero;
 309 }
 310
 311 void svc_rdma_xdr_encode_reply_array(struct rpcrdma_write_array *ary,
 312                                  int chunks)
 313 {
 314         ary->wc_discrim = xdr_one;
 315         ary->wc_nchunks = cpu_to_be32(chunks);
 316 }
 317
 318 void svc_rdma_xdr_encode_array_chunk(struct rpcrdma_write_array *ary,
 319                                      int chunk_no,
 320                                      __be32 rs_handle,
 321                                      __be64 rs_offset,
 322                                      u32 write_len)
 323 {
 324         struct rpcrdma_segment *seg = &ary->wc_array[chunk_no].wc_target;
 325         seg->rs_handle = rs_handle;
 326         seg->rs_offset = rs_offset;
 327         seg->rs_length = cpu_to_be32(write_len);
 328 }
 329
 330 void svc_rdma_xdr_encode_reply_header(struct svcxprt_rdma *xprt,
 331                                   struct rpcrdma_msg *rdma_argp,
 332                                   struct rpcrdma_msg *rdma_resp,
 333                                   enum rpcrdma_proc rdma_type)
 334 {
 335         rdma_resp->rm_xid = rdma_argp->rm_xid;
 336         rdma_resp->rm_vers = rdma_argp->rm_vers;
 337         rdma_resp->rm_credit = cpu_to_be32(xprt->sc_max_requests);
 338         rdma_resp->rm_type = cpu_to_be32(rdma_type);
 339
 340         /* Encode <nul> chunks lists */
 341         rdma_resp->rm_body.rm_chunks[0] = xdr_zero;
 342         rdma_resp->rm_body.rm_chunks[1] = xdr_zero;
 343         rdma_resp->rm_body.rm_chunks[2] = xdr_zero;
 344 }