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