1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind 4 * protocol 5 * 6 * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and 7 * RFC 3530: "Network File System (NFS) version 4 Protocol" 8 * 9 * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net> 10 * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com> 11 * 12 * Descended from net/sunrpc/pmap_clnt.c, 13 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de> 14 */ 15 16 #include <linux/module.h> 17 18 #include <linux/types.h> 19 #include <linux/socket.h> 20 #include <linux/un.h> 21 #include <linux/in.h> 22 #include <linux/in6.h> 23 #include <linux/kernel.h> 24 #include <linux/errno.h> 25 #include <linux/mutex.h> 26 #include <linux/slab.h> 27 #include <net/ipv6.h> 28 29 #include <linux/sunrpc/clnt.h> 30 #include <linux/sunrpc/addr.h> 31 #include <linux/sunrpc/sched.h> 32 #include <linux/sunrpc/xprtsock.h> 33 34 #include <trace/events/sunrpc.h> 35 36 #include "netns.h" 37 38 #define RPCBIND_SOCK_PATHNAME "/var/run/rpcbind.sock" 39 40 #define RPCBIND_PROGRAM (100000u) 41 #define RPCBIND_PORT (111u) 42 43 #define RPCBVERS_2 (2u) 44 #define RPCBVERS_3 (3u) 45 #define RPCBVERS_4 (4u) 46 47 enum { 48 RPCBPROC_NULL, 49 RPCBPROC_SET, 50 RPCBPROC_UNSET, 51 RPCBPROC_GETPORT, 52 RPCBPROC_GETADDR = 3, /* alias for GETPORT */ 53 RPCBPROC_DUMP, 54 RPCBPROC_CALLIT, 55 RPCBPROC_BCAST = 5, /* alias for CALLIT */ 56 RPCBPROC_GETTIME, 57 RPCBPROC_UADDR2TADDR, 58 RPCBPROC_TADDR2UADDR, 59 RPCBPROC_GETVERSADDR, 60 RPCBPROC_INDIRECT, 61 RPCBPROC_GETADDRLIST, 62 RPCBPROC_GETSTAT, 63 }; 64 65 /* 66 * r_owner 67 * 68 * The "owner" is allowed to unset a service in the rpcbind database. 69 * 70 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a 71 * UID which it maps to a local user name via a password lookup. 72 * In all other cases it is ignored. 73 * 74 * For SET/UNSET requests, user space provides a value, even for 75 * network requests, and GETADDR uses an empty string. We follow 76 * those precedents here. 77 */ 78 #define RPCB_OWNER_STRING "0" 79 #define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING) 80 81 /* 82 * XDR data type sizes 83 */ 84 #define RPCB_program_sz (1) 85 #define RPCB_version_sz (1) 86 #define RPCB_protocol_sz (1) 87 #define RPCB_port_sz (1) 88 #define RPCB_boolean_sz (1) 89 90 #define RPCB_netid_sz (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN)) 91 #define RPCB_addr_sz (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN)) 92 #define RPCB_ownerstring_sz (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN)) 93 94 /* 95 * XDR argument and result sizes 96 */ 97 #define RPCB_mappingargs_sz (RPCB_program_sz + RPCB_version_sz + \ 98 RPCB_protocol_sz + RPCB_port_sz) 99 #define RPCB_getaddrargs_sz (RPCB_program_sz + RPCB_version_sz + \ 100 RPCB_netid_sz + RPCB_addr_sz + \ 101 RPCB_ownerstring_sz) 102 103 #define RPCB_getportres_sz RPCB_port_sz 104 #define RPCB_setres_sz RPCB_boolean_sz 105 106 /* 107 * Note that RFC 1833 does not put any size restrictions on the 108 * address string returned by the remote rpcbind database. 109 */ 110 #define RPCB_getaddrres_sz RPCB_addr_sz 111 112 static void rpcb_getport_done(struct rpc_task *, void *); 113 static void rpcb_map_release(void *data); 114 static const struct rpc_program rpcb_program; 115 116 struct rpcbind_args { 117 struct rpc_xprt * r_xprt; 118 119 u32 r_prog; 120 u32 r_vers; 121 u32 r_prot; 122 unsigned short r_port; 123 const char * r_netid; 124 const char * r_addr; 125 const char * r_owner; 126 127 int r_status; 128 }; 129 130 static const struct rpc_procinfo rpcb_procedures2[]; 131 static const struct rpc_procinfo rpcb_procedures3[]; 132 static const struct rpc_procinfo rpcb_procedures4[]; 133 134 struct rpcb_info { 135 u32 rpc_vers; 136 const struct rpc_procinfo *rpc_proc; 137 }; 138 139 static const struct rpcb_info rpcb_next_version[]; 140 static const struct rpcb_info rpcb_next_version6[]; 141 142 static const struct rpc_call_ops rpcb_getport_ops = { 143 .rpc_call_done = rpcb_getport_done, 144 .rpc_release = rpcb_map_release, 145 }; 146 147 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status) 148 { 149 xprt_clear_binding(xprt); 150 rpc_wake_up_status(&xprt->binding, status); 151 } 152 153 static void rpcb_map_release(void *data) 154 { 155 struct rpcbind_args *map = data; 156 157 rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status); 158 xprt_put(map->r_xprt); 159 kfree(map->r_addr); 160 kfree(map); 161 } 162 163 static int rpcb_get_local(struct net *net) 164 { 165 int cnt; 166 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 167 168 spin_lock(&sn->rpcb_clnt_lock); 169 if (sn->rpcb_users) 170 sn->rpcb_users++; 171 cnt = sn->rpcb_users; 172 spin_unlock(&sn->rpcb_clnt_lock); 173 174 return cnt; 175 } 176 177 void rpcb_put_local(struct net *net) 178 { 179 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 180 struct rpc_clnt *clnt = sn->rpcb_local_clnt; 181 struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4; 182 int shutdown = 0; 183 184 spin_lock(&sn->rpcb_clnt_lock); 185 if (sn->rpcb_users) { 186 if (--sn->rpcb_users == 0) { 187 sn->rpcb_local_clnt = NULL; 188 sn->rpcb_local_clnt4 = NULL; 189 } 190 shutdown = !sn->rpcb_users; 191 } 192 spin_unlock(&sn->rpcb_clnt_lock); 193 194 if (shutdown) { 195 /* 196 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister 197 */ 198 if (clnt4) 199 rpc_shutdown_client(clnt4); 200 if (clnt) 201 rpc_shutdown_client(clnt); 202 } 203 } 204 205 static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt, 206 struct rpc_clnt *clnt4, 207 bool is_af_local) 208 { 209 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 210 211 /* Protected by rpcb_create_local_mutex */ 212 sn->rpcb_local_clnt = clnt; 213 sn->rpcb_local_clnt4 = clnt4; 214 sn->rpcb_is_af_local = is_af_local ? 1 : 0; 215 smp_wmb(); 216 sn->rpcb_users = 1; 217 } 218 219 /* 220 * Returns zero on success, otherwise a negative errno value 221 * is returned. 222 */ 223 static int rpcb_create_local_unix(struct net *net) 224 { 225 static const struct sockaddr_un rpcb_localaddr_rpcbind = { 226 .sun_family = AF_LOCAL, 227 .sun_path = RPCBIND_SOCK_PATHNAME, 228 }; 229 struct rpc_create_args args = { 230 .net = net, 231 .protocol = XPRT_TRANSPORT_LOCAL, 232 .address = (struct sockaddr *)&rpcb_localaddr_rpcbind, 233 .addrsize = sizeof(rpcb_localaddr_rpcbind), 234 .servername = "localhost", 235 .program = &rpcb_program, 236 .version = RPCBVERS_2, 237 .authflavor = RPC_AUTH_NULL, 238 .cred = current_cred(), 239 /* 240 * We turn off the idle timeout to prevent the kernel 241 * from automatically disconnecting the socket. 242 * Otherwise, we'd have to cache the mount namespace 243 * of the caller and somehow pass that to the socket 244 * reconnect code. 245 */ 246 .flags = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT, 247 }; 248 struct rpc_clnt *clnt, *clnt4; 249 int result = 0; 250 251 /* 252 * Because we requested an RPC PING at transport creation time, 253 * this works only if the user space portmapper is rpcbind, and 254 * it's listening on AF_LOCAL on the named socket. 255 */ 256 clnt = rpc_create(&args); 257 if (IS_ERR(clnt)) { 258 result = PTR_ERR(clnt); 259 goto out; 260 } 261 262 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4); 263 if (IS_ERR(clnt4)) 264 clnt4 = NULL; 265 266 rpcb_set_local(net, clnt, clnt4, true); 267 268 out: 269 return result; 270 } 271 272 /* 273 * Returns zero on success, otherwise a negative errno value 274 * is returned. 275 */ 276 static int rpcb_create_local_net(struct net *net) 277 { 278 static const struct sockaddr_in rpcb_inaddr_loopback = { 279 .sin_family = AF_INET, 280 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 281 .sin_port = htons(RPCBIND_PORT), 282 }; 283 struct rpc_create_args args = { 284 .net = net, 285 .protocol = XPRT_TRANSPORT_TCP, 286 .address = (struct sockaddr *)&rpcb_inaddr_loopback, 287 .addrsize = sizeof(rpcb_inaddr_loopback), 288 .servername = "localhost", 289 .program = &rpcb_program, 290 .version = RPCBVERS_2, 291 .authflavor = RPC_AUTH_UNIX, 292 .cred = current_cred(), 293 .flags = RPC_CLNT_CREATE_NOPING, 294 }; 295 struct rpc_clnt *clnt, *clnt4; 296 int result = 0; 297 298 clnt = rpc_create(&args); 299 if (IS_ERR(clnt)) { 300 result = PTR_ERR(clnt); 301 goto out; 302 } 303 304 /* 305 * This results in an RPC ping. On systems running portmapper, 306 * the v4 ping will fail. Proceed anyway, but disallow rpcb 307 * v4 upcalls. 308 */ 309 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4); 310 if (IS_ERR(clnt4)) 311 clnt4 = NULL; 312 313 rpcb_set_local(net, clnt, clnt4, false); 314 315 out: 316 return result; 317 } 318 319 /* 320 * Returns zero on success, otherwise a negative errno value 321 * is returned. 322 */ 323 int rpcb_create_local(struct net *net) 324 { 325 static DEFINE_MUTEX(rpcb_create_local_mutex); 326 int result = 0; 327 328 if (rpcb_get_local(net)) 329 return result; 330 331 mutex_lock(&rpcb_create_local_mutex); 332 if (rpcb_get_local(net)) 333 goto out; 334 335 if (rpcb_create_local_unix(net) != 0) 336 result = rpcb_create_local_net(net); 337 338 out: 339 mutex_unlock(&rpcb_create_local_mutex); 340 return result; 341 } 342 343 static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename, 344 const char *hostname, 345 struct sockaddr *srvaddr, size_t salen, 346 int proto, u32 version, 347 const struct cred *cred) 348 { 349 struct rpc_create_args args = { 350 .net = net, 351 .protocol = proto, 352 .address = srvaddr, 353 .addrsize = salen, 354 .servername = hostname, 355 .nodename = nodename, 356 .program = &rpcb_program, 357 .version = version, 358 .authflavor = RPC_AUTH_UNIX, 359 .cred = cred, 360 .flags = (RPC_CLNT_CREATE_NOPING | 361 RPC_CLNT_CREATE_NONPRIVPORT), 362 }; 363 364 switch (srvaddr->sa_family) { 365 case AF_INET: 366 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT); 367 break; 368 case AF_INET6: 369 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT); 370 break; 371 default: 372 return ERR_PTR(-EAFNOSUPPORT); 373 } 374 375 return rpc_create(&args); 376 } 377 378 static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set) 379 { 380 int flags = RPC_TASK_NOCONNECT; 381 int error, result = 0; 382 383 if (is_set || !sn->rpcb_is_af_local) 384 flags = RPC_TASK_SOFTCONN; 385 msg->rpc_resp = &result; 386 387 error = rpc_call_sync(clnt, msg, flags); 388 if (error < 0) 389 return error; 390 391 if (!result) 392 return -EACCES; 393 return 0; 394 } 395 396 /** 397 * rpcb_register - set or unset a port registration with the local rpcbind svc 398 * @net: target network namespace 399 * @prog: RPC program number to bind 400 * @vers: RPC version number to bind 401 * @prot: transport protocol to register 402 * @port: port value to register 403 * 404 * Returns zero if the registration request was dispatched successfully 405 * and the rpcbind daemon returned success. Otherwise, returns an errno 406 * value that reflects the nature of the error (request could not be 407 * dispatched, timed out, or rpcbind returned an error). 408 * 409 * RPC services invoke this function to advertise their contact 410 * information via the system's rpcbind daemon. RPC services 411 * invoke this function once for each [program, version, transport] 412 * tuple they wish to advertise. 413 * 414 * Callers may also unregister RPC services that are no longer 415 * available by setting the passed-in port to zero. This removes 416 * all registered transports for [program, version] from the local 417 * rpcbind database. 418 * 419 * This function uses rpcbind protocol version 2 to contact the 420 * local rpcbind daemon. 421 * 422 * Registration works over both AF_INET and AF_INET6, and services 423 * registered via this function are advertised as available for any 424 * address. If the local rpcbind daemon is listening on AF_INET6, 425 * services registered via this function will be advertised on 426 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6 427 * addresses). 428 */ 429 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port) 430 { 431 struct rpcbind_args map = { 432 .r_prog = prog, 433 .r_vers = vers, 434 .r_prot = prot, 435 .r_port = port, 436 }; 437 struct rpc_message msg = { 438 .rpc_argp = &map, 439 }; 440 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 441 bool is_set = false; 442 443 trace_pmap_register(prog, vers, prot, port); 444 445 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET]; 446 if (port != 0) { 447 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET]; 448 is_set = true; 449 } 450 451 return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set); 452 } 453 454 /* 455 * Fill in AF_INET family-specific arguments to register 456 */ 457 static int rpcb_register_inet4(struct sunrpc_net *sn, 458 const struct sockaddr *sap, 459 struct rpc_message *msg) 460 { 461 const struct sockaddr_in *sin = (const struct sockaddr_in *)sap; 462 struct rpcbind_args *map = msg->rpc_argp; 463 unsigned short port = ntohs(sin->sin_port); 464 bool is_set = false; 465 int result; 466 467 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); 468 469 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 470 if (port != 0) { 471 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET]; 472 is_set = true; 473 } 474 475 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set); 476 kfree(map->r_addr); 477 return result; 478 } 479 480 /* 481 * Fill in AF_INET6 family-specific arguments to register 482 */ 483 static int rpcb_register_inet6(struct sunrpc_net *sn, 484 const struct sockaddr *sap, 485 struct rpc_message *msg) 486 { 487 const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap; 488 struct rpcbind_args *map = msg->rpc_argp; 489 unsigned short port = ntohs(sin6->sin6_port); 490 bool is_set = false; 491 int result; 492 493 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); 494 495 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 496 if (port != 0) { 497 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET]; 498 is_set = true; 499 } 500 501 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set); 502 kfree(map->r_addr); 503 return result; 504 } 505 506 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn, 507 struct rpc_message *msg) 508 { 509 struct rpcbind_args *map = msg->rpc_argp; 510 511 trace_rpcb_unregister(map->r_prog, map->r_vers, map->r_netid); 512 513 map->r_addr = ""; 514 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 515 516 return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false); 517 } 518 519 /** 520 * rpcb_v4_register - set or unset a port registration with the local rpcbind 521 * @net: target network namespace 522 * @program: RPC program number of service to (un)register 523 * @version: RPC version number of service to (un)register 524 * @address: address family, IP address, and port to (un)register 525 * @netid: netid of transport protocol to (un)register 526 * 527 * Returns zero if the registration request was dispatched successfully 528 * and the rpcbind daemon returned success. Otherwise, returns an errno 529 * value that reflects the nature of the error (request could not be 530 * dispatched, timed out, or rpcbind returned an error). 531 * 532 * RPC services invoke this function to advertise their contact 533 * information via the system's rpcbind daemon. RPC services 534 * invoke this function once for each [program, version, address, 535 * netid] tuple they wish to advertise. 536 * 537 * Callers may also unregister RPC services that are registered at a 538 * specific address by setting the port number in @address to zero. 539 * They may unregister all registered protocol families at once for 540 * a service by passing a NULL @address argument. If @netid is "" 541 * then all netids for [program, version, address] are unregistered. 542 * 543 * This function uses rpcbind protocol version 4 to contact the 544 * local rpcbind daemon. The local rpcbind daemon must support 545 * version 4 of the rpcbind protocol in order for these functions 546 * to register a service successfully. 547 * 548 * Supported netids include "udp" and "tcp" for UDP and TCP over 549 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6, 550 * respectively. 551 * 552 * The contents of @address determine the address family and the 553 * port to be registered. The usual practice is to pass INADDR_ANY 554 * as the raw address, but specifying a non-zero address is also 555 * supported by this API if the caller wishes to advertise an RPC 556 * service on a specific network interface. 557 * 558 * Note that passing in INADDR_ANY does not create the same service 559 * registration as IN6ADDR_ANY. The former advertises an RPC 560 * service on any IPv4 address, but not on IPv6. The latter 561 * advertises the service on all IPv4 and IPv6 addresses. 562 */ 563 int rpcb_v4_register(struct net *net, const u32 program, const u32 version, 564 const struct sockaddr *address, const char *netid) 565 { 566 struct rpcbind_args map = { 567 .r_prog = program, 568 .r_vers = version, 569 .r_netid = netid, 570 .r_owner = RPCB_OWNER_STRING, 571 }; 572 struct rpc_message msg = { 573 .rpc_argp = &map, 574 }; 575 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 576 577 if (sn->rpcb_local_clnt4 == NULL) 578 return -EPROTONOSUPPORT; 579 580 if (address == NULL) 581 return rpcb_unregister_all_protofamilies(sn, &msg); 582 583 trace_rpcb_register(map.r_prog, map.r_vers, map.r_addr, map.r_netid); 584 585 switch (address->sa_family) { 586 case AF_INET: 587 return rpcb_register_inet4(sn, address, &msg); 588 case AF_INET6: 589 return rpcb_register_inet6(sn, address, &msg); 590 } 591 592 return -EAFNOSUPPORT; 593 } 594 595 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, 596 struct rpcbind_args *map, const struct rpc_procinfo *proc) 597 { 598 struct rpc_message msg = { 599 .rpc_proc = proc, 600 .rpc_argp = map, 601 .rpc_resp = map, 602 }; 603 struct rpc_task_setup task_setup_data = { 604 .rpc_client = rpcb_clnt, 605 .rpc_message = &msg, 606 .callback_ops = &rpcb_getport_ops, 607 .callback_data = map, 608 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN, 609 }; 610 611 return rpc_run_task(&task_setup_data); 612 } 613 614 /* 615 * In the case where rpc clients have been cloned, we want to make 616 * sure that we use the program number/version etc of the actual 617 * owner of the xprt. To do so, we walk back up the tree of parents 618 * to find whoever created the transport and/or whoever has the 619 * autobind flag set. 620 */ 621 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt) 622 { 623 struct rpc_clnt *parent = clnt->cl_parent; 624 struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch); 625 626 while (parent != clnt) { 627 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps) 628 break; 629 if (clnt->cl_autobind) 630 break; 631 clnt = parent; 632 parent = parent->cl_parent; 633 } 634 return clnt; 635 } 636 637 /** 638 * rpcb_getport_async - obtain the port for a given RPC service on a given host 639 * @task: task that is waiting for portmapper request 640 * 641 * This one can be called for an ongoing RPC request, and can be used in 642 * an async (rpciod) context. 643 */ 644 void rpcb_getport_async(struct rpc_task *task) 645 { 646 struct rpc_clnt *clnt; 647 const struct rpc_procinfo *proc; 648 u32 bind_version; 649 struct rpc_xprt *xprt; 650 struct rpc_clnt *rpcb_clnt; 651 struct rpcbind_args *map; 652 struct rpc_task *child; 653 struct sockaddr_storage addr; 654 struct sockaddr *sap = (struct sockaddr *)&addr; 655 size_t salen; 656 int status; 657 658 rcu_read_lock(); 659 clnt = rpcb_find_transport_owner(task->tk_client); 660 rcu_read_unlock(); 661 xprt = xprt_get(task->tk_xprt); 662 663 /* Put self on the wait queue to ensure we get notified if 664 * some other task is already attempting to bind the port */ 665 rpc_sleep_on_timeout(&xprt->binding, task, 666 NULL, jiffies + xprt->bind_timeout); 667 668 if (xprt_test_and_set_binding(xprt)) { 669 xprt_put(xprt); 670 return; 671 } 672 673 /* Someone else may have bound if we slept */ 674 if (xprt_bound(xprt)) { 675 status = 0; 676 goto bailout_nofree; 677 } 678 679 /* Parent transport's destination address */ 680 salen = rpc_peeraddr(clnt, sap, sizeof(addr)); 681 682 /* Don't ever use rpcbind v2 for AF_INET6 requests */ 683 switch (sap->sa_family) { 684 case AF_INET: 685 proc = rpcb_next_version[xprt->bind_index].rpc_proc; 686 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers; 687 break; 688 case AF_INET6: 689 proc = rpcb_next_version6[xprt->bind_index].rpc_proc; 690 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers; 691 break; 692 default: 693 status = -EAFNOSUPPORT; 694 goto bailout_nofree; 695 } 696 if (proc == NULL) { 697 xprt->bind_index = 0; 698 status = -EPFNOSUPPORT; 699 goto bailout_nofree; 700 } 701 702 trace_rpcb_getport(clnt, task, bind_version); 703 704 rpcb_clnt = rpcb_create(xprt->xprt_net, 705 clnt->cl_nodename, 706 xprt->servername, sap, salen, 707 xprt->prot, bind_version, 708 clnt->cl_cred); 709 if (IS_ERR(rpcb_clnt)) { 710 status = PTR_ERR(rpcb_clnt); 711 goto bailout_nofree; 712 } 713 714 map = kzalloc(sizeof(struct rpcbind_args), GFP_NOFS); 715 if (!map) { 716 status = -ENOMEM; 717 goto bailout_release_client; 718 } 719 map->r_prog = clnt->cl_prog; 720 map->r_vers = clnt->cl_vers; 721 map->r_prot = xprt->prot; 722 map->r_port = 0; 723 map->r_xprt = xprt; 724 map->r_status = -EIO; 725 726 switch (bind_version) { 727 case RPCBVERS_4: 728 case RPCBVERS_3: 729 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID]; 730 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_NOFS); 731 if (!map->r_addr) { 732 status = -ENOMEM; 733 goto bailout_free_args; 734 } 735 map->r_owner = ""; 736 break; 737 case RPCBVERS_2: 738 map->r_addr = NULL; 739 break; 740 default: 741 BUG(); 742 } 743 744 child = rpcb_call_async(rpcb_clnt, map, proc); 745 rpc_release_client(rpcb_clnt); 746 747 xprt->stat.bind_count++; 748 rpc_put_task(child); 749 return; 750 751 bailout_free_args: 752 kfree(map); 753 bailout_release_client: 754 rpc_release_client(rpcb_clnt); 755 bailout_nofree: 756 rpcb_wake_rpcbind_waiters(xprt, status); 757 task->tk_status = status; 758 xprt_put(xprt); 759 } 760 EXPORT_SYMBOL_GPL(rpcb_getport_async); 761 762 /* 763 * Rpcbind child task calls this callback via tk_exit. 764 */ 765 static void rpcb_getport_done(struct rpc_task *child, void *data) 766 { 767 struct rpcbind_args *map = data; 768 struct rpc_xprt *xprt = map->r_xprt; 769 770 map->r_status = child->tk_status; 771 772 /* Garbage reply: retry with a lesser rpcbind version */ 773 if (map->r_status == -EIO) 774 map->r_status = -EPROTONOSUPPORT; 775 776 /* rpcbind server doesn't support this rpcbind protocol version */ 777 if (map->r_status == -EPROTONOSUPPORT) 778 xprt->bind_index++; 779 780 if (map->r_status < 0) { 781 /* rpcbind server not available on remote host? */ 782 map->r_port = 0; 783 784 } else if (map->r_port == 0) { 785 /* Requested RPC service wasn't registered on remote host */ 786 map->r_status = -EACCES; 787 } else { 788 /* Succeeded */ 789 map->r_status = 0; 790 } 791 792 trace_rpcb_setport(child, map->r_status, map->r_port); 793 xprt->ops->set_port(xprt, map->r_port); 794 if (map->r_port) 795 xprt_set_bound(xprt); 796 } 797 798 /* 799 * XDR functions for rpcbind 800 */ 801 802 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr, 803 const void *data) 804 { 805 const struct rpcbind_args *rpcb = data; 806 __be32 *p; 807 808 p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2); 809 *p++ = cpu_to_be32(rpcb->r_prog); 810 *p++ = cpu_to_be32(rpcb->r_vers); 811 *p++ = cpu_to_be32(rpcb->r_prot); 812 *p = cpu_to_be32(rpcb->r_port); 813 } 814 815 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr, 816 void *data) 817 { 818 struct rpcbind_args *rpcb = data; 819 unsigned long port; 820 __be32 *p; 821 822 rpcb->r_port = 0; 823 824 p = xdr_inline_decode(xdr, 4); 825 if (unlikely(p == NULL)) 826 return -EIO; 827 828 port = be32_to_cpup(p); 829 if (unlikely(port > USHRT_MAX)) 830 return -EIO; 831 832 rpcb->r_port = port; 833 return 0; 834 } 835 836 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr, 837 void *data) 838 { 839 unsigned int *boolp = data; 840 __be32 *p; 841 842 p = xdr_inline_decode(xdr, 4); 843 if (unlikely(p == NULL)) 844 return -EIO; 845 846 *boolp = 0; 847 if (*p != xdr_zero) 848 *boolp = 1; 849 return 0; 850 } 851 852 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string, 853 const u32 maxstrlen) 854 { 855 __be32 *p; 856 u32 len; 857 858 len = strlen(string); 859 WARN_ON_ONCE(len > maxstrlen); 860 if (len > maxstrlen) 861 /* truncate and hope for the best */ 862 len = maxstrlen; 863 p = xdr_reserve_space(xdr, 4 + len); 864 xdr_encode_opaque(p, string, len); 865 } 866 867 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr, 868 const void *data) 869 { 870 const struct rpcbind_args *rpcb = data; 871 __be32 *p; 872 873 p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2); 874 *p++ = cpu_to_be32(rpcb->r_prog); 875 *p = cpu_to_be32(rpcb->r_vers); 876 877 encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN); 878 encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN); 879 encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN); 880 } 881 882 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr, 883 void *data) 884 { 885 struct rpcbind_args *rpcb = data; 886 struct sockaddr_storage address; 887 struct sockaddr *sap = (struct sockaddr *)&address; 888 __be32 *p; 889 u32 len; 890 891 rpcb->r_port = 0; 892 893 p = xdr_inline_decode(xdr, 4); 894 if (unlikely(p == NULL)) 895 goto out_fail; 896 len = be32_to_cpup(p); 897 898 /* 899 * If the returned universal address is a null string, 900 * the requested RPC service was not registered. 901 */ 902 if (len == 0) 903 return 0; 904 905 if (unlikely(len > RPCBIND_MAXUADDRLEN)) 906 goto out_fail; 907 908 p = xdr_inline_decode(xdr, len); 909 if (unlikely(p == NULL)) 910 goto out_fail; 911 912 if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len, 913 sap, sizeof(address)) == 0) 914 goto out_fail; 915 rpcb->r_port = rpc_get_port(sap); 916 917 return 0; 918 919 out_fail: 920 return -EIO; 921 } 922 923 /* 924 * Not all rpcbind procedures described in RFC 1833 are implemented 925 * since the Linux kernel RPC code requires only these. 926 */ 927 928 static const struct rpc_procinfo rpcb_procedures2[] = { 929 [RPCBPROC_SET] = { 930 .p_proc = RPCBPROC_SET, 931 .p_encode = rpcb_enc_mapping, 932 .p_decode = rpcb_dec_set, 933 .p_arglen = RPCB_mappingargs_sz, 934 .p_replen = RPCB_setres_sz, 935 .p_statidx = RPCBPROC_SET, 936 .p_timer = 0, 937 .p_name = "SET", 938 }, 939 [RPCBPROC_UNSET] = { 940 .p_proc = RPCBPROC_UNSET, 941 .p_encode = rpcb_enc_mapping, 942 .p_decode = rpcb_dec_set, 943 .p_arglen = RPCB_mappingargs_sz, 944 .p_replen = RPCB_setres_sz, 945 .p_statidx = RPCBPROC_UNSET, 946 .p_timer = 0, 947 .p_name = "UNSET", 948 }, 949 [RPCBPROC_GETPORT] = { 950 .p_proc = RPCBPROC_GETPORT, 951 .p_encode = rpcb_enc_mapping, 952 .p_decode = rpcb_dec_getport, 953 .p_arglen = RPCB_mappingargs_sz, 954 .p_replen = RPCB_getportres_sz, 955 .p_statidx = RPCBPROC_GETPORT, 956 .p_timer = 0, 957 .p_name = "GETPORT", 958 }, 959 }; 960 961 static const struct rpc_procinfo rpcb_procedures3[] = { 962 [RPCBPROC_SET] = { 963 .p_proc = RPCBPROC_SET, 964 .p_encode = rpcb_enc_getaddr, 965 .p_decode = rpcb_dec_set, 966 .p_arglen = RPCB_getaddrargs_sz, 967 .p_replen = RPCB_setres_sz, 968 .p_statidx = RPCBPROC_SET, 969 .p_timer = 0, 970 .p_name = "SET", 971 }, 972 [RPCBPROC_UNSET] = { 973 .p_proc = RPCBPROC_UNSET, 974 .p_encode = rpcb_enc_getaddr, 975 .p_decode = rpcb_dec_set, 976 .p_arglen = RPCB_getaddrargs_sz, 977 .p_replen = RPCB_setres_sz, 978 .p_statidx = RPCBPROC_UNSET, 979 .p_timer = 0, 980 .p_name = "UNSET", 981 }, 982 [RPCBPROC_GETADDR] = { 983 .p_proc = RPCBPROC_GETADDR, 984 .p_encode = rpcb_enc_getaddr, 985 .p_decode = rpcb_dec_getaddr, 986 .p_arglen = RPCB_getaddrargs_sz, 987 .p_replen = RPCB_getaddrres_sz, 988 .p_statidx = RPCBPROC_GETADDR, 989 .p_timer = 0, 990 .p_name = "GETADDR", 991 }, 992 }; 993 994 static const struct rpc_procinfo rpcb_procedures4[] = { 995 [RPCBPROC_SET] = { 996 .p_proc = RPCBPROC_SET, 997 .p_encode = rpcb_enc_getaddr, 998 .p_decode = rpcb_dec_set, 999 .p_arglen = RPCB_getaddrargs_sz, 1000 .p_replen = RPCB_setres_sz, 1001 .p_statidx = RPCBPROC_SET, 1002 .p_timer = 0, 1003 .p_name = "SET", 1004 }, 1005 [RPCBPROC_UNSET] = { 1006 .p_proc = RPCBPROC_UNSET, 1007 .p_encode = rpcb_enc_getaddr, 1008 .p_decode = rpcb_dec_set, 1009 .p_arglen = RPCB_getaddrargs_sz, 1010 .p_replen = RPCB_setres_sz, 1011 .p_statidx = RPCBPROC_UNSET, 1012 .p_timer = 0, 1013 .p_name = "UNSET", 1014 }, 1015 [RPCBPROC_GETADDR] = { 1016 .p_proc = RPCBPROC_GETADDR, 1017 .p_encode = rpcb_enc_getaddr, 1018 .p_decode = rpcb_dec_getaddr, 1019 .p_arglen = RPCB_getaddrargs_sz, 1020 .p_replen = RPCB_getaddrres_sz, 1021 .p_statidx = RPCBPROC_GETADDR, 1022 .p_timer = 0, 1023 .p_name = "GETADDR", 1024 }, 1025 }; 1026 1027 static const struct rpcb_info rpcb_next_version[] = { 1028 { 1029 .rpc_vers = RPCBVERS_2, 1030 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT], 1031 }, 1032 { 1033 .rpc_proc = NULL, 1034 }, 1035 }; 1036 1037 static const struct rpcb_info rpcb_next_version6[] = { 1038 { 1039 .rpc_vers = RPCBVERS_4, 1040 .rpc_proc = &rpcb_procedures4[RPCBPROC_GETADDR], 1041 }, 1042 { 1043 .rpc_vers = RPCBVERS_3, 1044 .rpc_proc = &rpcb_procedures3[RPCBPROC_GETADDR], 1045 }, 1046 { 1047 .rpc_proc = NULL, 1048 }, 1049 }; 1050 1051 static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)]; 1052 static const struct rpc_version rpcb_version2 = { 1053 .number = RPCBVERS_2, 1054 .nrprocs = ARRAY_SIZE(rpcb_procedures2), 1055 .procs = rpcb_procedures2, 1056 .counts = rpcb_version2_counts, 1057 }; 1058 1059 static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)]; 1060 static const struct rpc_version rpcb_version3 = { 1061 .number = RPCBVERS_3, 1062 .nrprocs = ARRAY_SIZE(rpcb_procedures3), 1063 .procs = rpcb_procedures3, 1064 .counts = rpcb_version3_counts, 1065 }; 1066 1067 static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)]; 1068 static const struct rpc_version rpcb_version4 = { 1069 .number = RPCBVERS_4, 1070 .nrprocs = ARRAY_SIZE(rpcb_procedures4), 1071 .procs = rpcb_procedures4, 1072 .counts = rpcb_version4_counts, 1073 }; 1074 1075 static const struct rpc_version *rpcb_version[] = { 1076 NULL, 1077 NULL, 1078 &rpcb_version2, 1079 &rpcb_version3, 1080 &rpcb_version4 1081 }; 1082 1083 static struct rpc_stat rpcb_stats; 1084 1085 static const struct rpc_program rpcb_program = { 1086 .name = "rpcbind", 1087 .number = RPCBIND_PROGRAM, 1088 .nrvers = ARRAY_SIZE(rpcb_version), 1089 .version = rpcb_version, 1090 .stats = &rpcb_stats, 1091 }; 1092