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
  18 #include <stdio.h>
  19 #include <strings.h>
  20 #include <stdlib.h>
  21 #include <errno.h>
  22 #include <rpc/rpc.h>
  23 #include <rpc/xdr.h>
  24 #include <rpc/rpc_msg.h>
  25 #include "slist.h"
  26 #include "libnfs.h"
  27 #include "libnfs-raw.h"
  28 #include "libnfs-private.h"
  29
  30 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)
  31 {
  32         struct rpc_pdu *pdu;
  33         struct rpc_msg msg;
  34
  35         if (rpc == NULL) {
  36                 return NULL;
  37         }
  38
  39         pdu = malloc(sizeof(struct rpc_pdu));
  40         if (pdu == NULL) {
  41                 rpc_set_error(rpc, "Out of memory: Failed to allocate pdu structure");
  42                 return NULL;
  43         }
  44         bzero(pdu, sizeof(struct rpc_pdu));
  45         pdu->xid                = rpc->xid++;
  46         pdu->cb                 = cb;
  47         pdu->private_data       = private_data;
  48         pdu->xdr_decode_fn      = xdr_decode_fn;
  49         pdu->xdr_decode_bufsize = xdr_decode_bufsize;
  50
  51         xdrmem_create(&pdu->xdr, rpc->encodebuf, rpc->encodebuflen, XDR_ENCODE);
  52         if (rpc->is_udp == 0) {
  53                 xdr_setpos(&pdu->xdr, 4); /* skip past the record marker */
  54         }
  55
  56         bzero(&msg, sizeof(struct rpc_msg));
  57         msg.rm_xid = pdu->xid;
  58         msg.rm_direction = CALL;
  59         msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
  60         msg.rm_call.cb_prog = program;
  61         msg.rm_call.cb_vers = version;
  62         msg.rm_call.cb_proc = procedure;
  63         msg.rm_call.cb_cred = rpc->auth->ah_cred;
  64         msg.rm_call.cb_verf = rpc->auth->ah_verf;
  65
  66         if (xdr_callmsg(&pdu->xdr, &msg) == 0) {
  67                 rpc_set_error(rpc, "xdr_callmsg failed");
  68                 xdr_destroy(&pdu->xdr);
  69                 free(pdu);
  70                 return NULL;
  71         }
  72
  73         return pdu;
  74 }
  75
  76 void rpc_free_pdu(struct rpc_context *rpc _U_, struct rpc_pdu *pdu)
  77 {
  78         if (pdu->outdata.data != NULL) {
  79                 free(pdu->outdata.data);
  80                 pdu->outdata.data = NULL;
  81         }
  82
  83         if (pdu->xdr_decode_buf != NULL) {
  84                 xdr_free(pdu->xdr_decode_fn, pdu->xdr_decode_buf);
  85                 free(pdu->xdr_decode_buf);
  86                 pdu->xdr_decode_buf = NULL;
  87         }
  88
  89         xdr_destroy(&pdu->xdr);
  90
  91         free(pdu);
  92 }
  93
  94
  95 int rpc_queue_pdu(struct rpc_context *rpc, struct rpc_pdu *pdu)
  96 {
  97         int size, recordmarker;
  98
  99         size = xdr_getpos(&pdu->xdr);
 100
 101         /* for udp we dont queue, we just send it straight away */
 102         if (rpc->is_udp != 0) {
 103                 if (sendto(rpc->fd, rpc->encodebuf, size, MSG_DONTWAIT, rpc->udp_dest, sizeof(struct sockaddr_in)) < 0) {
 104                         rpc_set_error(rpc, "Sendto failed with errno %s", strerror(errno));
 105                         rpc_free_pdu(rpc, pdu);
 106                         return -1;
 107                 }
 108                 SLIST_ADD_END(&rpc->waitpdu, pdu);
 109                 return 0;
 110         }
 111
 112         /* write recordmarker */
 113         xdr_setpos(&pdu->xdr, 0);
 114         recordmarker = (size - 4) | 0x80000000;
 115         xdr_int(&pdu->xdr, &recordmarker);
 116
 117         pdu->outdata.size = size;
 118         pdu->outdata.data = malloc(pdu->outdata.size);
 119         if (pdu->outdata.data == NULL) {
 120                 rpc_set_error(rpc, "Out of memory. Failed to allocate buffer for pdu\n");
 121                 rpc_free_pdu(rpc, pdu);
 122                 return -1;
 123         }
 124
 125         memcpy(pdu->outdata.data, rpc->encodebuf, pdu->outdata.size);
 126         SLIST_ADD_END(&rpc->outqueue, pdu);
 127
 128         return 0;
 129 }
 130
 131 int rpc_get_pdu_size(char *buf)
 132 {
 133         uint32_t size;
 134
 135         size = ntohl(*(uint32_t *)buf);
 136
 137         if ((size & 0x80000000) == 0) {
 138                 /* cant handle oncrpc fragments */
 139                 return -1;
 140         }
 141
 142         return (size & 0x7fffffff) + 4;
 143 }
 144
 145 static int rpc_process_reply(struct rpc_context *rpc, struct rpc_pdu *pdu, XDR *xdr)
 146 {
 147         struct rpc_msg msg;
 148
 149         bzero(&msg, sizeof(struct rpc_msg));
 150         msg.acpted_rply.ar_verf = _null_auth;
 151         if (pdu->xdr_decode_bufsize > 0) {
 152                 if (pdu->xdr_decode_buf != NULL) {
 153                         free(pdu->xdr_decode_buf);
 154                 }
 155                 pdu->xdr_decode_buf = malloc(pdu->xdr_decode_bufsize);
 156                 if (pdu->xdr_decode_buf == NULL) {
 157                         rpc_set_error(rpc, "xdr_replymsg failed in portmap_getport_reply");
 158                         pdu->cb(rpc, RPC_STATUS_ERROR, "Failed to allocate buffer for decoding of XDR reply", pdu->private_data);
 159                         return 0;
 160                 }
 161                 bzero(pdu->xdr_decode_buf, pdu->xdr_decode_bufsize);
 162         }
 163         msg.acpted_rply.ar_results.where = pdu->xdr_decode_buf;
 164         msg.acpted_rply.ar_results.proc  = pdu->xdr_decode_fn;
 165
 166         if (xdr_replymsg(xdr, &msg) == 0) {
 167                 rpc_set_error(rpc, "xdr_replymsg failed in portmap_getport_reply");
 168                 pdu->cb(rpc, RPC_STATUS_ERROR, "Message rejected by server", pdu->private_data);
 169                 if (pdu->xdr_decode_buf != NULL) {
 170                         free(pdu->xdr_decode_buf);
 171                         pdu->xdr_decode_buf = NULL;
 172                 }
 173                 return 0;
 174         }
 175         if (msg.rm_reply.rp_stat != MSG_ACCEPTED) {
 176                 pdu->cb(rpc, RPC_STATUS_ERROR, "RPC Packet not accepted by the server", pdu->private_data);
 177                 return 0;
 178         }
 179         switch (msg.rm_reply.rp_acpt.ar_stat) {
 180         case SUCCESS:
 181                 pdu->cb(rpc, RPC_STATUS_SUCCESS, pdu->xdr_decode_buf, pdu->private_data);
 182                 break;
 183         case PROG_UNAVAIL:
 184                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Program not available", pdu->private_data);
 185                 break;
 186         case PROG_MISMATCH:
 187                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Program version mismatch", pdu->private_data);
 188                 break;
 189         case PROC_UNAVAIL:
 190                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Procedure not available", pdu->private_data);
 191                 break;
 192         case GARBAGE_ARGS:
 193                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: Garbage arguments", pdu->private_data);
 194                 break;
 195         case SYSTEM_ERR:
 196                 pdu->cb(rpc, RPC_STATUS_ERROR, "Server responded: System Error", pdu->private_data);
 197                 break;
 198         default:
 199                 pdu->cb(rpc, RPC_STATUS_ERROR, "Unknown rpc response from server", pdu->private_data);
 200                 break;
 201         }
 202
 203         return 0;
 204 }
 205
 206 int rpc_process_pdu(struct rpc_context *rpc, char *buf, int size)
 207 {
 208         struct rpc_pdu *pdu;
 209         XDR xdr;
 210         int pos, recordmarker;
 211         unsigned int xid;
 212
 213         bzero(&xdr, sizeof(XDR));
 214
 215         xdrmem_create(&xdr, buf, size, XDR_DECODE);
 216         if (rpc->is_udp == 0) {
 217                 if (xdr_int(&xdr, &recordmarker) == 0) {
 218                         rpc_set_error(rpc, "xdr_int reading recordmarker failed");
 219                         xdr_destroy(&xdr);
 220                         return -1;
 221                 }
 222         }
 223         pos = xdr_getpos(&xdr);
 224         if (xdr_int(&xdr, (int *)&xid) == 0) {
 225                 rpc_set_error(rpc, "xdr_int reading xid failed");
 226                 xdr_destroy(&xdr);
 227                 return -1;
 228         }
 229         xdr_setpos(&xdr, pos);
 230
 231         for (pdu=rpc->waitpdu; pdu; pdu=pdu->next) {
 232                 if (pdu->xid != xid) {
 233                         continue;
 234                 }
 235                 if (rpc->is_udp == 0 || rpc->is_broadcast == 0) {
 236                         SLIST_REMOVE(&rpc->waitpdu, pdu);
 237                 }
 238                 if (rpc_process_reply(rpc, pdu, &xdr) != 0) {
 239                         rpc_set_error(rpc, "rpc_procdess_reply failed");
 240                 }
 241                 xdr_destroy(&xdr);
 242                 if (rpc->is_udp == 0 || rpc->is_broadcast == 0) {
 243                         rpc_free_pdu(rpc, pdu);
 244                 }
 245                 return 0;
 246         }
 247         rpc_set_error(rpc, "No matching pdu found for xid:%d", xid);
 248         xdr_destroy(&xdr);
 249         return -1;
 250 }
 251