rpc.c revision 330898
1/* $NetBSD: rpc.c,v 1.18 1998/01/23 19:27:45 thorpej Exp $ */ 2 3/* 4 * Copyright (c) 1992 Regents of the University of California. 5 * All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 4. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 * 35 * @(#) Header: rpc.c,v 1.12 93/09/28 08:31:56 leres Exp (LBL) 36 */ 37 38#include <sys/cdefs.h> 39__FBSDID("$FreeBSD: stable/11/stand/libsa/rpc.c 330898 2018-03-14 03:30:34Z kevans $"); 40 41/* 42 * RPC functions used by NFS and bootparams. 43 * Note that bootparams requires the ability to find out the 44 * address of the server from which its response has come. 45 * This is supported by keeping the IP/UDP headers in the 46 * buffer space provided by the caller. (See rpc_fromaddr) 47 */ 48 49#include <sys/param.h> 50#include <sys/socket.h> 51 52#include <netinet/in.h> 53#include <netinet/in_systm.h> 54 55#include <string.h> 56 57#include "rpcv2.h" 58 59#include "stand.h" 60#include "net.h" 61#include "netif.h" 62#include "rpc.h" 63 64struct auth_info { 65 int32_t authtype; /* auth type */ 66 u_int32_t authlen; /* auth length */ 67}; 68 69struct auth_unix { 70 int32_t ua_time; 71 int32_t ua_hostname; /* null */ 72 int32_t ua_uid; 73 int32_t ua_gid; 74 int32_t ua_gidlist; /* null */ 75}; 76 77struct rpc_call { 78 u_int32_t rp_xid; /* request transaction id */ 79 int32_t rp_direction; /* call direction (0) */ 80 u_int32_t rp_rpcvers; /* rpc version (2) */ 81 u_int32_t rp_prog; /* program */ 82 u_int32_t rp_vers; /* version */ 83 u_int32_t rp_proc; /* procedure */ 84}; 85 86struct rpc_reply { 87 u_int32_t rp_xid; /* request transaction id */ 88 int32_t rp_direction; /* call direction (1) */ 89 int32_t rp_astatus; /* accept status (0: accepted) */ 90 union { 91 u_int32_t rpu_errno; 92 struct { 93 struct auth_info rok_auth; 94 u_int32_t rok_status; 95 } rpu_rok; 96 } rp_u; 97}; 98 99/* Local forwards */ 100static ssize_t recvrpc(struct iodesc *, void **, void **, time_t, void *); 101static int rpc_getport(struct iodesc *, n_long, n_long); 102 103int rpc_xid; 104int rpc_port = 0x400; /* predecrement */ 105 106/* 107 * Make a rpc call; return length of answer 108 * Note: Caller must leave room for headers. 109 */ 110ssize_t 111rpc_call(struct iodesc *d, n_long prog, n_long vers, n_long proc, 112 void *sdata, size_t slen, void **rdata, void **pkt) 113{ 114 ssize_t cc, rsize; 115 struct auth_info *auth; 116 struct rpc_call *call; 117 struct rpc_reply *reply; 118 char *send_head, *send_tail; 119 void *ptr; 120 n_long x; 121 int port; /* host order */ 122 123#ifdef RPC_DEBUG 124 if (debug) 125 printf("rpc_call: prog=0x%x vers=%d proc=%d\n", 126 prog, vers, proc); 127#endif 128 129 port = rpc_getport(d, prog, vers); 130 if (port == -1) 131 return (-1); 132 133 d->destport = htons(port); 134 135 /* 136 * Prepend authorization stuff and headers. 137 * Note, must prepend things in reverse order. 138 */ 139 send_head = sdata; 140 send_tail = (char *)sdata + slen; 141 142 /* Auth verifier is always auth_null */ 143 send_head -= sizeof(*auth); 144 auth = (struct auth_info *)send_head; 145 auth->authtype = htonl(RPCAUTH_NULL); 146 auth->authlen = 0; 147 148 /* Auth credentials: always auth unix (as root) */ 149 send_head -= sizeof(struct auth_unix); 150 bzero(send_head, sizeof(struct auth_unix)); 151 send_head -= sizeof(*auth); 152 auth = (struct auth_info *)send_head; 153 auth->authtype = htonl(RPCAUTH_UNIX); 154 auth->authlen = htonl(sizeof(struct auth_unix)); 155 156 /* RPC call structure. */ 157 send_head -= sizeof(*call); 158 call = (struct rpc_call *)send_head; 159 rpc_xid++; 160 call->rp_xid = htonl(rpc_xid); 161 call->rp_direction = htonl(RPC_CALL); 162 call->rp_rpcvers = htonl(RPC_VER2); 163 call->rp_prog = htonl(prog); 164 call->rp_vers = htonl(vers); 165 call->rp_proc = htonl(proc); 166 167 ptr = NULL; 168 cc = sendrecv(d, 169 sendudp, send_head, send_tail - send_head, 170 recvrpc, &ptr, (void **)&reply, NULL); 171 172#ifdef RPC_DEBUG 173 if (debug) 174 printf("callrpc: cc=%zd\n", cc); 175#endif 176 if (cc == -1) 177 return (-1); 178 179 if (cc <= sizeof(*reply)) { 180 errno = EBADRPC; 181 free(ptr); 182 return (-1); 183 } 184 185 /* 186 * Check the RPC reply status. 187 * The xid, dir, astatus were already checked. 188 */ 189 auth = &reply->rp_u.rpu_rok.rok_auth; 190 x = ntohl(auth->authlen); 191 if (x != 0) { 192#ifdef RPC_DEBUG 193 if (debug) 194 printf("callrpc: reply auth != NULL\n"); 195#endif 196 errno = EBADRPC; 197 free(ptr); 198 return (-1); 199 } 200 x = ntohl(reply->rp_u.rpu_rok.rok_status); 201 if (x != 0) { 202 printf("callrpc: error = %ld\n", (long)x); 203 errno = EBADRPC; 204 free(ptr); 205 return (-1); 206 } 207 208 rsize = cc - sizeof(*reply); 209 *rdata = (void *)((uintptr_t)reply + sizeof(*reply)); 210 *pkt = ptr; 211 return (rsize); 212} 213 214/* 215 * Returns true if packet is the one we're waiting for. 216 * This just checks the XID, direction, acceptance. 217 * Remaining checks are done by callrpc 218 */ 219static ssize_t 220recvrpc(struct iodesc *d, void **pkt, void **payload, time_t tleft, void *extra) 221{ 222 void *ptr; 223 struct rpc_reply *reply; 224 ssize_t n; 225 int x; 226 227 errno = 0; 228#ifdef RPC_DEBUG 229 if (debug) 230 printf("recvrpc: called\n"); 231#endif 232 233 ptr = NULL; 234 n = readudp(d, &ptr, (void **)&reply, tleft); 235 if (n <= (4 * 4)) { 236 free(ptr); 237 return (-1); 238 } 239 240 x = ntohl(reply->rp_xid); 241 if (x != rpc_xid) { 242#ifdef RPC_DEBUG 243 if (debug) 244 printf("recvrpc: rp_xid %d != xid %d\n", x, rpc_xid); 245#endif 246 free(ptr); 247 return (-1); 248 } 249 250 x = ntohl(reply->rp_direction); 251 if (x != RPC_REPLY) { 252#ifdef RPC_DEBUG 253 if (debug) 254 printf("recvrpc: rp_direction %d != REPLY\n", x); 255#endif 256 free(ptr); 257 return (-1); 258 } 259 260 x = ntohl(reply->rp_astatus); 261 if (x != RPC_MSGACCEPTED) { 262 errno = ntohl(reply->rp_u.rpu_errno); 263 printf("recvrpc: reject, astat=%d, errno=%d\n", x, errno); 264 free(ptr); 265 return (-1); 266 } 267 268 *pkt = ptr; 269 *payload = reply; 270 /* Return data count (thus indicating success) */ 271 return (n); 272} 273 274/* 275 * Given a pointer to a reply just received, 276 * dig out the IP address/port from the headers. 277 */ 278void 279rpc_fromaddr(void *pkt, struct in_addr *addr, u_short *port) 280{ 281 struct hackhdr { 282 /* Tail of IP header: just IP addresses */ 283 n_long ip_src; 284 n_long ip_dst; 285 /* UDP header: */ 286 u_int16_t uh_sport; /* source port */ 287 u_int16_t uh_dport; /* destination port */ 288 int16_t uh_ulen; /* udp length */ 289 u_int16_t uh_sum; /* udp checksum */ 290 /* RPC reply header: */ 291 struct rpc_reply rpc; 292 } *hhdr; 293 294 hhdr = ((struct hackhdr *)pkt) - 1; 295 addr->s_addr = hhdr->ip_src; 296 *port = hhdr->uh_sport; 297} 298 299/* 300 * RPC Portmapper cache 301 */ 302#define PMAP_NUM 8 /* need at most 5 pmap entries */ 303 304int rpc_pmap_num; 305struct pmap_list { 306 struct in_addr addr; /* server, net order */ 307 u_int prog; /* host order */ 308 u_int vers; /* host order */ 309 int port; /* host order */ 310} rpc_pmap_list[PMAP_NUM]; 311 312/* 313 * return port number in host order, or -1. 314 * arguments are: 315 * addr .. server, net order. 316 * prog .. host order. 317 * vers .. host order. 318 */ 319int 320rpc_pmap_getcache(struct in_addr addr, u_int prog, u_int vers) 321{ 322 struct pmap_list *pl; 323 324 for (pl = rpc_pmap_list; pl < &rpc_pmap_list[rpc_pmap_num]; pl++) { 325 if (pl->addr.s_addr == addr.s_addr && 326 pl->prog == prog && pl->vers == vers ) 327 { 328 return (pl->port); 329 } 330 } 331 return (-1); 332} 333 334/* 335 * arguments are: 336 * addr .. server, net order. 337 * prog .. host order. 338 * vers .. host order. 339 * port .. host order. 340 */ 341void 342rpc_pmap_putcache(struct in_addr addr, u_int prog, u_int vers, int port) 343{ 344 struct pmap_list *pl; 345 346 /* Don't overflow cache... */ 347 if (rpc_pmap_num >= PMAP_NUM) { 348 /* ... just re-use the last entry. */ 349 rpc_pmap_num = PMAP_NUM - 1; 350#ifdef RPC_DEBUG 351 printf("rpc_pmap_putcache: cache overflow\n"); 352#endif 353 } 354 355 pl = &rpc_pmap_list[rpc_pmap_num]; 356 rpc_pmap_num++; 357 358 /* Cache answer */ 359 pl->addr = addr; 360 pl->prog = prog; 361 pl->vers = vers; 362 pl->port = port; 363} 364 365 366/* 367 * Request a port number from the port mapper. 368 * Returns the port in host order. 369 * prog and vers are host order. 370 */ 371int 372rpc_getport(struct iodesc *d, n_long prog, n_long vers) 373{ 374 struct args { 375 n_long prog; /* call program */ 376 n_long vers; /* call version */ 377 n_long proto; /* call protocol */ 378 n_long port; /* call port (unused) */ 379 } *args; 380 struct res { 381 n_long port; 382 } *res; 383 struct { 384 n_long h[RPC_HEADER_WORDS]; 385 struct args d; 386 } sdata; 387 void *pkt; 388 ssize_t cc; 389 int port; 390 391#ifdef RPC_DEBUG 392 if (debug) 393 printf("%s: prog=0x%x vers=%d\n", __func__, prog, vers); 394#endif 395 396 /* This one is fixed forever. */ 397 if (prog == PMAPPROG) { 398 port = PMAPPORT; 399 goto out; 400 } 401 402 /* Try for cached answer first */ 403 port = rpc_pmap_getcache(d->destip, prog, vers); 404 if (port != -1) 405 goto out; 406 407 args = &sdata.d; 408 args->prog = htonl(prog); 409 args->vers = htonl(vers); 410 args->proto = htonl(IPPROTO_UDP); 411 args->port = 0; 412 pkt = NULL; 413 414 cc = rpc_call(d, PMAPPROG, PMAPVERS, PMAPPROC_GETPORT, 415 args, sizeof(*args), (void **)&res, &pkt); 416 if (cc < sizeof(*res)) { 417 printf("getport: %s", strerror(errno)); 418 errno = EBADRPC; 419 free(pkt); 420 return (-1); 421 } 422 port = (int)ntohl(res->port); 423 free(pkt); 424 425 rpc_pmap_putcache(d->destip, prog, vers, port); 426 427out: 428#ifdef RPC_DEBUG 429 if (debug) 430 printf("%s: port=%u\n", __func__, port); 431#endif 432 return (port); 433} 434