1 /* $OpenBSD: clnt_udp.c,v 1.35 2018/01/06 15:37:36 cheloha Exp $ */ 2 3 /* 4 * Copyright (c) 2010, Oracle America, Inc. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are 8 * met: 9 * 10 * * Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * * Redistributions in binary form must reproduce the above 13 * copyright notice, this list of conditions and the following 14 * disclaimer in the documentation and/or other materials 15 * provided with the distribution. 16 * * Neither the name of the "Oracle America, Inc." nor the names of its 17 * contributors may be used to endorse or promote products derived 18 * from this software without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 21 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 22 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 23 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 24 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 25 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE 27 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 28 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 29 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 30 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 32 */ 33 34 /* 35 * clnt_udp.c, Implements a UDP/IP based, client side RPC. 36 */ 37 38 #include <stdio.h> 39 #include <stdlib.h> 40 #include <string.h> 41 #include <unistd.h> 42 #include <fcntl.h> 43 #include <rpc/rpc.h> 44 #include <sys/socket.h> 45 #include <netdb.h> 46 #include <errno.h> 47 #include <rpc/pmap_clnt.h> 48 49 /* 50 * UDP bases client side rpc operations 51 */ 52 static enum clnt_stat clntudp_call(CLIENT *, u_long, xdrproc_t, caddr_t, 53 xdrproc_t, caddr_t, struct timeval); 54 static void clntudp_abort(CLIENT *); 55 static void clntudp_geterr(CLIENT *, struct rpc_err *); 56 static bool_t clntudp_freeres(CLIENT *, xdrproc_t, caddr_t); 57 static bool_t clntudp_control(CLIENT *, u_int, void *); 58 static void clntudp_destroy(CLIENT *); 59 60 static struct clnt_ops udp_ops = { 61 clntudp_call, 62 clntudp_abort, 63 clntudp_geterr, 64 clntudp_freeres, 65 clntudp_destroy, 66 clntudp_control 67 }; 68 69 /* 70 * Private data kept per client handle 71 */ 72 struct cu_data { 73 int cu_sock; 74 bool_t cu_closeit; 75 struct sockaddr_in cu_raddr; 76 int cu_rlen; 77 struct timeval cu_wait; 78 struct timeval cu_total; 79 struct rpc_err cu_error; 80 XDR cu_outxdrs; 81 u_int cu_xdrpos; 82 u_int cu_sendsz; 83 char *cu_outbuf; 84 u_int cu_recvsz; 85 char cu_inbuf[1]; 86 }; 87 88 /* 89 * Create a UDP based client handle. 90 * If *sockp<0, *sockp is set to a newly created UPD socket. 91 * If raddr->sin_port is 0 a binder on the remote machine 92 * is consulted for the correct port number. 93 * NB: It is the client's responsibility to close *sockp, unless 94 * clntudp_bufcreate() was called with *sockp = -1 (so it created 95 * the socket), and CLNT_DESTROY() is used. 96 * NB: The rpch->cl_auth is initialized to null authentication. 97 * Caller may wish to set this something more useful. 98 * 99 * wait is the amount of time used between retransmitting a call if 100 * no response has been heard; retransmission occurs until the actual 101 * rpc call times out. 102 * 103 * sendsz and recvsz are the maximum allowable packet sizes that can be 104 * sent and received. 105 */ 106 CLIENT * 107 clntudp_bufcreate(struct sockaddr_in *raddr, u_long program, u_long version, 108 struct timeval wait, int *sockp, u_int sendsz, u_int recvsz) 109 { 110 CLIENT *cl; 111 struct cu_data *cu = NULL; 112 struct rpc_msg call_msg; 113 114 cl = (CLIENT *)mem_alloc(sizeof(CLIENT)); 115 if (cl == NULL) { 116 rpc_createerr.cf_stat = RPC_SYSTEMERROR; 117 rpc_createerr.cf_error.re_errno = errno; 118 goto fooy; 119 } 120 sendsz = ((sendsz + 3) / 4) * 4; 121 recvsz = ((recvsz + 3) / 4) * 4; 122 cu = (struct cu_data *)mem_alloc(sizeof(*cu) + sendsz + recvsz); 123 if (cu == NULL) { 124 rpc_createerr.cf_stat = RPC_SYSTEMERROR; 125 rpc_createerr.cf_error.re_errno = errno; 126 goto fooy; 127 } 128 cu->cu_outbuf = &cu->cu_inbuf[recvsz]; 129 130 if (raddr->sin_port == 0) { 131 u_short port; 132 if ((port = 133 pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) { 134 goto fooy; 135 } 136 raddr->sin_port = htons(port); 137 } 138 cl->cl_ops = &udp_ops; 139 cl->cl_private = (caddr_t)cu; 140 cu->cu_raddr = *raddr; 141 cu->cu_rlen = sizeof (cu->cu_raddr); 142 cu->cu_wait = wait; 143 cu->cu_total.tv_sec = -1; 144 cu->cu_total.tv_usec = -1; 145 cu->cu_sendsz = sendsz; 146 cu->cu_recvsz = recvsz; 147 call_msg.rm_xid = arc4random(); 148 call_msg.rm_direction = CALL; 149 call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION; 150 call_msg.rm_call.cb_prog = program; 151 call_msg.rm_call.cb_vers = version; 152 xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf, 153 sendsz, XDR_ENCODE); 154 if (!xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) { 155 goto fooy; 156 } 157 cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs)); 158 if (*sockp < 0) { 159 *sockp = socket(AF_INET, SOCK_DGRAM | SOCK_NONBLOCK, 160 IPPROTO_UDP); 161 if (*sockp < 0) { 162 rpc_createerr.cf_stat = RPC_SYSTEMERROR; 163 rpc_createerr.cf_error.re_errno = errno; 164 goto fooy; 165 } 166 /* attempt to bind to priv port */ 167 (void)bindresvport(*sockp, NULL); 168 cu->cu_closeit = TRUE; 169 } else { 170 cu->cu_closeit = FALSE; 171 } 172 cu->cu_sock = *sockp; 173 cl->cl_auth = authnone_create(); 174 if (cl->cl_auth == NULL) { 175 rpc_createerr.cf_stat = RPC_SYSTEMERROR; 176 rpc_createerr.cf_error.re_errno = errno; 177 goto fooy; 178 } 179 return (cl); 180 fooy: 181 if (cu) 182 mem_free((caddr_t)cu, sizeof(*cu) + sendsz + recvsz); 183 if (cl) 184 mem_free((caddr_t)cl, sizeof(CLIENT)); 185 return (NULL); 186 } 187 DEF_WEAK(clntudp_bufcreate); 188 189 CLIENT * 190 clntudp_create(struct sockaddr_in *raddr, u_long program, u_long version, 191 struct timeval wait, int *sockp) 192 { 193 194 return(clntudp_bufcreate(raddr, program, version, wait, sockp, 195 UDPMSGSIZE, UDPMSGSIZE)); 196 } 197 DEF_WEAK(clntudp_create); 198 199 static enum clnt_stat 200 clntudp_call(CLIENT *cl, /* client handle */ 201 u_long proc, /* procedure number */ 202 xdrproc_t xargs, /* xdr routine for args */ 203 caddr_t argsp, /* pointer to args */ 204 xdrproc_t xresults, /* xdr routine for results */ 205 caddr_t resultsp, /* pointer to results */ 206 struct timeval utimeout) /* seconds to wait before giving up */ 207 { 208 struct cu_data *cu = (struct cu_data *)cl->cl_private; 209 XDR *xdrs; 210 int outlen; 211 int inlen; 212 socklen_t fromlen; 213 struct pollfd pfd[1]; 214 struct sockaddr_in from; 215 struct rpc_msg reply_msg; 216 XDR reply_xdrs; 217 struct timespec time_waited, start, after, duration, wait; 218 bool_t ok; 219 int nrefreshes = 2; /* number of times to refresh cred */ 220 struct timespec timeout; 221 222 if (cu->cu_total.tv_usec == -1) 223 TIMEVAL_TO_TIMESPEC(&utimeout, &timeout); /* use supplied timeout */ 224 else 225 TIMEVAL_TO_TIMESPEC(&cu->cu_total, &timeout); /* use default timeout */ 226 227 pfd[0].fd = cu->cu_sock; 228 pfd[0].events = POLLIN; 229 timespecclear(&time_waited); 230 TIMEVAL_TO_TIMESPEC(&cu->cu_wait, &wait); 231 call_again: 232 xdrs = &(cu->cu_outxdrs); 233 xdrs->x_op = XDR_ENCODE; 234 XDR_SETPOS(xdrs, cu->cu_xdrpos); 235 /* 236 * the transaction is the first thing in the out buffer 237 */ 238 (*(u_short *)(cu->cu_outbuf))++; 239 if (!XDR_PUTLONG(xdrs, (long *)&proc) || 240 !AUTH_MARSHALL(cl->cl_auth, xdrs) || 241 !(*xargs)(xdrs, argsp)) { 242 return (cu->cu_error.re_status = RPC_CANTENCODEARGS); 243 } 244 outlen = (int)XDR_GETPOS(xdrs); 245 246 send_again: 247 if (sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0, 248 (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen) != outlen) { 249 cu->cu_error.re_errno = errno; 250 return (cu->cu_error.re_status = RPC_CANTSEND); 251 } 252 253 /* 254 * Hack to provide rpc-based message passing 255 */ 256 if (!timespecisset(&timeout)) 257 return (cu->cu_error.re_status = RPC_TIMEDOUT); 258 259 /* 260 * sub-optimal code appears here because we have 261 * some clock time to spare while the packets are in flight. 262 * (We assume that this is actually only executed once.) 263 */ 264 reply_msg.acpted_rply.ar_verf = _null_auth; 265 reply_msg.acpted_rply.ar_results.where = resultsp; 266 reply_msg.acpted_rply.ar_results.proc = xresults; 267 268 clock_gettime(CLOCK_MONOTONIC, &start); 269 for (;;) { 270 switch (ppoll(pfd, 1, &wait, NULL)) { 271 case 0: 272 timespecadd(&time_waited, &wait, &time_waited); 273 if (timespeccmp(&time_waited, &timeout, <)) 274 goto send_again; 275 return (cu->cu_error.re_status = RPC_TIMEDOUT); 276 case 1: 277 if (pfd[0].revents & POLLNVAL) 278 errno = EBADF; 279 else if (pfd[0].revents & POLLERR) 280 errno = EIO; 281 else 282 break; 283 /* FALLTHROUGH */ 284 case -1: 285 if (errno == EINTR) { 286 clock_gettime(CLOCK_MONOTONIC, &after); 287 timespecsub(&after, &start, &duration); 288 timespecadd(&time_waited, &duration, &time_waited); 289 if (timespeccmp(&time_waited, &timeout, <)) 290 continue; 291 return (cu->cu_error.re_status = RPC_TIMEDOUT); 292 } 293 cu->cu_error.re_errno = errno; 294 return (cu->cu_error.re_status = RPC_CANTRECV); 295 } 296 297 do { 298 fromlen = sizeof(struct sockaddr); 299 inlen = recvfrom(cu->cu_sock, cu->cu_inbuf, 300 (int) cu->cu_recvsz, 0, 301 (struct sockaddr *)&from, &fromlen); 302 } while (inlen < 0 && errno == EINTR); 303 if (inlen < 0) { 304 if (errno == EWOULDBLOCK) 305 continue; 306 cu->cu_error.re_errno = errno; 307 return (cu->cu_error.re_status = RPC_CANTRECV); 308 } 309 if (inlen < sizeof(u_int32_t)) 310 continue; 311 /* see if reply transaction id matches sent id */ 312 if (((struct rpc_msg *)(cu->cu_inbuf))->rm_xid != 313 ((struct rpc_msg *)(cu->cu_outbuf))->rm_xid) 314 continue; 315 /* we now assume we have the proper reply */ 316 break; 317 } 318 319 /* 320 * now decode and validate the response 321 */ 322 xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE); 323 ok = xdr_replymsg(&reply_xdrs, &reply_msg); 324 /* XDR_DESTROY(&reply_xdrs); save a few cycles on noop destroy */ 325 if (ok) { 326 #if 0 327 /* 328 * XXX Would like to check these, but call_msg is not 329 * around. 330 */ 331 if (reply_msg.rm_call.cb_prog != call_msg.rm_call.cb_prog || 332 reply_msg.rm_call.cb_vers != call_msg.rm_call.cb_vers || 333 reply_msg.rm_call.cb_proc != call_msg.rm_call.cb_proc) { 334 goto call_again; /* XXX spin? */ 335 } 336 #endif 337 338 _seterr_reply(&reply_msg, &(cu->cu_error)); 339 if (cu->cu_error.re_status == RPC_SUCCESS) { 340 if (!AUTH_VALIDATE(cl->cl_auth, 341 &reply_msg.acpted_rply.ar_verf)) { 342 cu->cu_error.re_status = RPC_AUTHERROR; 343 cu->cu_error.re_why = AUTH_INVALIDRESP; 344 } 345 if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) { 346 xdrs->x_op = XDR_FREE; 347 (void)xdr_opaque_auth(xdrs, 348 &(reply_msg.acpted_rply.ar_verf)); 349 } 350 } else { 351 /* maybe our credentials need to be refreshed ... */ 352 if (nrefreshes > 0 && AUTH_REFRESH(cl->cl_auth)) { 353 nrefreshes--; 354 goto call_again; 355 } 356 } 357 } else { 358 /* xdr_replymsg() may have left some things allocated */ 359 int op = reply_xdrs.x_op; 360 reply_xdrs.x_op = XDR_FREE; 361 xdr_replymsg(&reply_xdrs, &reply_msg); 362 reply_xdrs.x_op = op; 363 cu->cu_error.re_status = RPC_CANTDECODERES; 364 } 365 366 return (cu->cu_error.re_status); 367 } 368 369 static void 370 clntudp_geterr(CLIENT *cl, struct rpc_err *errp) 371 { 372 struct cu_data *cu = (struct cu_data *)cl->cl_private; 373 374 *errp = cu->cu_error; 375 } 376 377 378 static bool_t 379 clntudp_freeres(CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr) 380 { 381 struct cu_data *cu = (struct cu_data *)cl->cl_private; 382 XDR *xdrs = &(cu->cu_outxdrs); 383 384 xdrs->x_op = XDR_FREE; 385 return ((*xdr_res)(xdrs, res_ptr)); 386 } 387 388 static void 389 clntudp_abort(CLIENT *clnt) 390 { 391 } 392 393 static bool_t 394 clntudp_control(CLIENT *cl, u_int request, void *info) 395 { 396 struct cu_data *cu = (struct cu_data *)cl->cl_private; 397 398 switch (request) { 399 case CLSET_TIMEOUT: 400 cu->cu_total = *(struct timeval *)info; 401 break; 402 case CLGET_TIMEOUT: 403 *(struct timeval *)info = cu->cu_total; 404 break; 405 case CLSET_RETRY_TIMEOUT: 406 cu->cu_wait = *(struct timeval *)info; 407 break; 408 case CLGET_RETRY_TIMEOUT: 409 *(struct timeval *)info = cu->cu_wait; 410 break; 411 case CLGET_SERVER_ADDR: 412 *(struct sockaddr_in *)info = cu->cu_raddr; 413 break; 414 default: 415 return (FALSE); 416 } 417 return (TRUE); 418 } 419 420 static void 421 clntudp_destroy(CLIENT *cl) 422 { 423 struct cu_data *cu = (struct cu_data *)cl->cl_private; 424 425 if (cu->cu_closeit && cu->cu_sock != -1) { 426 (void)close(cu->cu_sock); 427 } 428 XDR_DESTROY(&(cu->cu_outxdrs)); 429 mem_free((caddr_t)cu, (sizeof(*cu) + cu->cu_sendsz + cu->cu_recvsz)); 430 mem_free((caddr_t)cl, sizeof(CLIENT)); 431 } 432