lib/pdu.c

   1 /*
   2    Copyright (C) 2010 by Ronnie Sahlberg <ronniesahlberg@gmail.com>
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU Lesser General Public License as published by
   6    the Free Software Foundation; either version 2.1 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public License
  15    along with this program; if not, see <http://www.gnu.org/licenses/>.
  16 */
  17 #ifdef WIN32
  18 #include "win32_compat.h"
  19 #ifndef MSG_DONTWAIT
  20 #define MSG_DONTWAIT 0
  21 #endif
  22 #else
  23 #include <strings.h>
  24 #endif/*WIN32*/
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <assert.h>
  29 #include <errno.h>
  30 #include <rpc/rpc.h>
  31 #include <rpc/xdr.h>
  32 #include <rpc/rpc_msg.h>
  33 #include "slist.h"
  34 #include "libnfs.h"
  35 #include "libnfs-raw.h"
  36 #include "libnfs-private.h"
  37
  38 struct rpc_pdu *rpc_allocate_pdu(struct rpc_context *rpc, int program, int version, int procedure, rpc_cb cb, void *private_data, xdrproc_t xdr_decode_fn, int xdr_decode_bufsize)
  39 {
  40         struct rpc_pdu *pdu;
  41         struct rpc_msg msg;
  42
  43         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  44
  45         pdu = malloc(sizeof(struct rpc_pdu));
  46         if (pdu == NULL) {
  47                 rpc_set_error(rpc, "Out of memory: Failed to allocate pdu structure");
  48                 return NULL;
  49         }
  50         memset(pdu, 0, sizeof(struct rpc_pdu));
  51         pdu->xid                = rpc->xid++;
  52         pdu->cb                 = cb;
  53         pdu->private_data       = private_data;
  54         pdu->xdr_decode_fn      = xdr_decode_fn;
  55         pdu->xdr_decode_bufsize = xdr_decode_bufsize;
  56
  57         xdrmem_create(&pdu->xdr, rpc->encodebuf, rpc->encodebuflen, XDR_ENCODE);
  58         if (rpc->is_udp == 0) {
  59                 xdr_setpos(&pdu->xdr, 4); /* skip past the record marker */
  60         }
  61
  62         memset(&msg, 0, sizeof(struct rpc_msg));
  63         msg.rm_xid = pdu->xid;
  64         msg.rm_direction = CALL;
  65         msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
  66         msg.rm_call.cb_prog = program;
  67         msg.rm_call.cb_vers = version;
  68         msg.rm_call.cb_proc = procedure;
  69         msg.rm_call.cb_cred = rpc->auth->ah_cred;
  70         msg.rm_call.cb_verf = rpc->auth->ah_verf;
  71
  72         if (xdr_callmsg(&pdu->xdr, &msg) == 0) {
  73                 rpc_set_error(rpc, "xdr_callmsg failed");
  74                 xdr_destroy(&pdu->xdr);
  75                 free(pdu);
  76                 return NULL;
  77         }
  78
  79         return pdu;
  80 }
  81
  82 void rpc_free_pdu(struct rpc_context *rpc, struct rpc_pdu *pdu)
  83 {
  84         assert(rpc->magic == RPC_CONTEXT_MAGIC);
  85
  86         if (pdu->outdata.data != NULL) {
  87                 free(pdu->outdata.data);
  88                 pdu->outdata.data = NULL;
  89         }
  90
  91         if (pdu->xdr_decode_buf != NULL) {
  92                 xdr_free(pdu->xdr_decode_fn, pdu->xdr_decode_buf);
  93                 free(pdu->xdr_decode_buf);
  94                 pdu->xdr_decode_buf = NULL;
  95         }
  96
  97         xdr_destroy(&pdu->xdr);
  98
  99         free(pdu);
 100 }
 101
 102
 103 int rpc_queue_pdu(struct rpc_context *rpc, struct rpc_pdu *pdu)
 104 {
 105         int size, recordmarker;
 106
 107         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 108
 109         size = xdr_getpos(&pdu->xdr);
 110
 111         /* for udp we dont queue, we just send it straight away */
 112         if (rpc->is_udp != 0) {
 113                 if (sendto(rpc->fd, rpc->encodebuf, size, MSG_DONTWAIT, rpc->udp_dest, sizeof(struct sockaddr_in)) < 0) {
 114                         rpc_set_error(rpc, "Sendto failed with errno %s", strerror(errno));
 115                         rpc_free_pdu(rpc, pdu);
 116                         return -1;
 117                 }
 118                 SLIST_ADD_END(&rpc->waitpdu, pdu);
 119                 return 0;
 120         }
 121
 122         /* write recordmarker */
 123         xdr_setpos(&pdu->xdr, 0);
 124         recordmarker = (size - 4) | 0x80000000;
 125         xdr_int(&pdu->xdr, &recordmarker);
 126
 127         pdu->outdata.size = size;
 128         pdu->outdata.data = malloc(pdu->outdata.size);
 129         if (pdu->outdata.data == NULL) {
 130                 rpc_set_error(rpc, "Out of memory. Failed to allocate buffer for pdu\n");
 131                 rpc_free_pdu(rpc, pdu);
 132                 return -1;
 133         }
 134
 135         memcpy(pdu->outdata.data, rpc->encodebuf, pdu->outdata.size);
 136         SLIST_ADD_END(&rpc->outqueue, pdu);
 137
 138         return 0;
 139 }
 140
 141 int rpc_get_pdu_size(char *buf)
 142 {
 143         uint32_t size;
 144
 145         size = ntohl(*(uint32_t *)buf);
 146
 147         return (size & 0x7fffffff) + 4;
 148 }
 149
 150 static int rpc_process_reply(struct rpc_context *rpc, struct rpc_pdu *pdu, XDR *xdr)
 151 {
 152         struct rpc_msg msg;
 153
 154         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 155
 156         memset(&msg, 0, sizeof(struct rpc_msg));
 157         msg.acpted_rply.ar_verf = _null_auth;
 158         if (pdu->xdr_decode_bufsize > 0) {
 159                 if (pdu->xdr_decode_buf != NULL) {
 160                         free(pdu->xdr_decode_buf);
 161                 }
 162                 pdu->xdr_decode_buf = malloc(pdu->xdr_decode_bufsize);
 163                 if (pdu->xdr_decode_buf == NULL) {
 164                         rpc_set_error(rpc, "xdr_replymsg failed in portmap_getport_reply");
 165                         pdu->cb(rpc, RPC_STATUS_ERROR, "Failed to allocate buffer for decoding of XDR reply", pdu->private_data);
 166                         return 0;
 167                 }
 168                 memset(pdu->xdr_decode_buf, 0, pdu->xdr_decode_bufsize);
 169         }
 170         msg.acpted_rply.ar_results.where = pdu->xdr_decode_buf;
 171         msg.acpted_rply.ar_results.proc  = pdu->xdr_decode_fn;
 172
 173         if (xdr_replymsg(xdr, &msg) == 0) {
 174                 rpc_set_error(rpc, "xdr_replymsg failed in portmap_getport_reply");
 175                 pdu->cb(rpc, RPC_STATUS_ERROR, "Message rejected by server", pdu->private_data);
 176                 if (pdu->xdr_decode_buf != NULL) {
 177                         free(pdu->xdr_decode_buf);
 178                         pdu->xdr_decode_buf = NULL;
 179                 }
 180                 return 0;
 181         }
 182         if (msg.rm_reply.rp_stat != MSG_ACCEPTED) {
 183                 pdu->cb(rpc, RPC_STATUS_ERROR, "RPC Packet not accepted by the server", pdu->private_data);
 184                 return 0;
 185         }
 186         switch (msg.rm_reply.rp_acpt.ar_stat) {
 187         case SUCCESS:
 188                 pdu->cb(rpc, RPC_STATUS_SUCCESS, pdu->xdr_decode_buf, pdu->private_data);
 189                 break;
 190         case PROG_UNAVAIL:
 191                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Program not available", pdu->private_data);
 192                 break;
 193         case PROG_MISMATCH:
 194                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Program version mismatch", pdu->private_data);
 195                 break;
 196         case PROC_UNAVAIL:
 197                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Procedure not available", pdu->private_data);
 198                 break;
 199         case GARBAGE_ARGS:
 200                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Garbage arguments", pdu->private_data);
 201                 break;
 202         case SYSTEM_ERR:
 203                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: System Error", pdu->private_data);
 204                 break;
 205         default:
 206                 pdu->cb(rpc, RPC_STATUS_ERROR, "Unknown rpc response from server", pdu->private_data);
 207                 break;
 208         }
 209
 210         return 0;
 211 }
 212
 213 int rpc_process_pdu(struct rpc_context *rpc, char *buf, int size)
 214 {
 215         struct rpc_pdu *pdu;
 216         XDR xdr;
 217         int pos, recordmarker = 0;
 218         unsigned int xid;
 219         char *reasbuf = NULL;
 220
 221         assert(rpc->magic == RPC_CONTEXT_MAGIC);
 222
 223         memset(&xdr, 0, sizeof(XDR));
 224
 225         xdrmem_create(&xdr, buf, size, XDR_DECODE);
 226         if (rpc->is_udp == 0) {
 227                 if (xdr_int(&xdr, &recordmarker) == 0) {
 228                         rpc_set_error(rpc, "xdr_int reading recordmarker failed");
 229                         xdr_destroy(&xdr);
 230                         return -1;
 231                 }
 232                 if (!(recordmarker&0x80000000)) {
 233                         xdr_destroy(&xdr);
 234                         if (rpc_add_fragment(rpc, buf+4, size-4) != 0) {
 235                                 rpc_set_error(rpc, "Failed to queue fragment for reassembly.");
 236                                 return -1;
 237                         }
 238                         return 0;
 239                 }
 240         }
 241
 242         /* reassembly */
 243         if (recordmarker != 0 && rpc->fragments != NULL) {
 244                 struct rpc_fragment *fragment;
 245                 uint64_t total = size - 4;
 246                 char *ptr;
 247
 248                 xdr_destroy(&xdr);
 249                 for (fragment = rpc->fragments; fragment; fragment = fragment->next) {
 250                         total += fragment->size;
 251                 }
 252
 253                 reasbuf = malloc(total);
 254                 if (reasbuf == NULL) {
 255                         rpc_set_error(rpc, "Failed to reassemble PDU");
 256                         rpc_free_all_fragments(rpc);
 257                         return -1;
 258                 }
 259                 ptr = reasbuf;
 260                 for (fragment = rpc->fragments; fragment; fragment = fragment->next) {
 261                         memcpy(ptr, fragment->data, fragment->size);
 262                         ptr += fragment->size;
 263                 }
 264                 memcpy(ptr, buf + 4, size - 4);
 265                 xdrmem_create(&xdr, reasbuf, total, XDR_DECODE);
 266                 rpc_free_all_fragments(rpc);
 267         }
 268
 269         pos = xdr_getpos(&xdr);
 270         if (xdr_int(&xdr, (int *)&xid) == 0) {
 271                 rpc_set_error(rpc, "xdr_int reading xid failed");
 272                 xdr_destroy(&xdr);
 273                 if (reasbuf != NULL) {
 274                         free(reasbuf);
 275                 }
 276                 return -1;
 277         }
 278         xdr_setpos(&xdr, pos);
 279
 280         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 281                 if (pdu->xid != xid) {
 282                         continue;
 283                 }
 284                 if (rpc->is_udp == 0 || rpc->is_broadcast == 0) {
 285                         SLIST_REMOVE(&rpc->waitpdu, pdu);
 286                 }
 287                 if (rpc_process_reply(rpc, pdu, &xdr) != 0) {
 288                         rpc_set_error(rpc, "rpc_procdess_reply failed");
 289                 }
 290                 xdr_destroy(&xdr);
 291                 if (rpc->is_udp == 0 || rpc->is_broadcast == 0) {
 292                         rpc_free_pdu(rpc, pdu);
 293                 }
 294                 if (reasbuf != NULL) {
 295                         free(reasbuf);
 296                 }
 297                 return 0;
 298         }
 299         rpc_set_error(rpc, "No matching pdu found for xid:%d", xid);
 300         xdr_destroy(&xdr);
 301         if (reasbuf != NULL) {
 302                 free(reasbuf);
 303         }
 304         return -1;
 305 }
 306