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 #define RPCBIND_SOCK_ABSTRACT_NAME "\0/run/rpcbind.sock" 40 41 #define RPCBIND_PROGRAM (100000u) 42 #define RPCBIND_PORT (111u) 43 44 #define RPCBVERS_2 (2u) 45 #define RPCBVERS_3 (3u) 46 #define RPCBVERS_4 (4u) 47 48 enum { 49 RPCBPROC_NULL, 50 RPCBPROC_SET, 51 RPCBPROC_UNSET, 52 RPCBPROC_GETPORT, 53 RPCBPROC_GETADDR = 3, /* alias for GETPORT */ 54 RPCBPROC_DUMP, 55 RPCBPROC_CALLIT, 56 RPCBPROC_BCAST = 5, /* alias for CALLIT */ 57 RPCBPROC_GETTIME, 58 RPCBPROC_UADDR2TADDR, 59 RPCBPROC_TADDR2UADDR, 60 RPCBPROC_GETVERSADDR, 61 RPCBPROC_INDIRECT, 62 RPCBPROC_GETADDRLIST, 63 RPCBPROC_GETSTAT, 64 }; 65 66 /* 67 * r_owner 68 * 69 * The "owner" is allowed to unset a service in the rpcbind database. 70 * 71 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a 72 * UID which it maps to a local user name via a password lookup. 73 * In all other cases it is ignored. 74 * 75 * For SET/UNSET requests, user space provides a value, even for 76 * network requests, and GETADDR uses an empty string. We follow 77 * those precedents here. 78 */ 79 #define RPCB_OWNER_STRING "0" 80 #define RPCB_MAXOWNERLEN sizeof(RPCB_OWNER_STRING) 81 82 /* 83 * XDR data type sizes 84 */ 85 #define RPCB_program_sz (1) 86 #define RPCB_version_sz (1) 87 #define RPCB_protocol_sz (1) 88 #define RPCB_port_sz (1) 89 #define RPCB_boolean_sz (1) 90 91 #define RPCB_netid_sz (1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN)) 92 #define RPCB_addr_sz (1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN)) 93 #define RPCB_ownerstring_sz (1 + XDR_QUADLEN(RPCB_MAXOWNERLEN)) 94 95 /* 96 * XDR argument and result sizes 97 */ 98 #define RPCB_mappingargs_sz (RPCB_program_sz + RPCB_version_sz + \ 99 RPCB_protocol_sz + RPCB_port_sz) 100 #define RPCB_getaddrargs_sz (RPCB_program_sz + RPCB_version_sz + \ 101 RPCB_netid_sz + RPCB_addr_sz + \ 102 RPCB_ownerstring_sz) 103 104 #define RPCB_getportres_sz RPCB_port_sz 105 #define RPCB_setres_sz RPCB_boolean_sz 106 107 /* 108 * Note that RFC 1833 does not put any size restrictions on the 109 * address string returned by the remote rpcbind database. 110 */ 111 #define RPCB_getaddrres_sz RPCB_addr_sz 112 113 static void rpcb_getport_done(struct rpc_task *, void *); 114 static void rpcb_map_release(void *data); 115 static const struct rpc_program rpcb_program; 116 117 struct rpcbind_args { 118 struct rpc_xprt * r_xprt; 119 120 u32 r_prog; 121 u32 r_vers; 122 u32 r_prot; 123 unsigned short r_port; 124 const char * r_netid; 125 const char * r_addr; 126 const char * r_owner; 127 128 int r_status; 129 }; 130 131 static const struct rpc_procinfo rpcb_procedures2[]; 132 static const struct rpc_procinfo rpcb_procedures3[]; 133 static const struct rpc_procinfo rpcb_procedures4[]; 134 135 struct rpcb_info { 136 u32 rpc_vers; 137 const struct rpc_procinfo *rpc_proc; 138 }; 139 140 static const struct rpcb_info rpcb_next_version[]; 141 static const struct rpcb_info rpcb_next_version6[]; 142 143 static const struct rpc_call_ops rpcb_getport_ops = { 144 .rpc_call_done = rpcb_getport_done, 145 .rpc_release = rpcb_map_release, 146 }; 147 148 static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status) 149 { 150 xprt_clear_binding(xprt); 151 rpc_wake_up_status(&xprt->binding, status); 152 } 153 154 static void rpcb_map_release(void *data) 155 { 156 struct rpcbind_args *map = data; 157 158 rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status); 159 xprt_put(map->r_xprt); 160 kfree(map->r_addr); 161 kfree(map); 162 } 163 164 static int rpcb_get_local(struct net *net) 165 { 166 int cnt; 167 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 168 169 spin_lock(&sn->rpcb_clnt_lock); 170 if (sn->rpcb_users) 171 sn->rpcb_users++; 172 cnt = sn->rpcb_users; 173 spin_unlock(&sn->rpcb_clnt_lock); 174 175 return cnt; 176 } 177 178 void rpcb_put_local(struct net *net) 179 { 180 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 181 struct rpc_clnt *clnt = sn->rpcb_local_clnt; 182 struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4; 183 int shutdown = 0; 184 185 spin_lock(&sn->rpcb_clnt_lock); 186 if (sn->rpcb_users) { 187 if (--sn->rpcb_users == 0) { 188 sn->rpcb_local_clnt = NULL; 189 sn->rpcb_local_clnt4 = NULL; 190 } 191 shutdown = !sn->rpcb_users; 192 } 193 spin_unlock(&sn->rpcb_clnt_lock); 194 195 if (shutdown) { 196 /* 197 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister 198 */ 199 if (clnt4) 200 rpc_shutdown_client(clnt4); 201 if (clnt) 202 rpc_shutdown_client(clnt); 203 } 204 } 205 206 static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt, 207 struct rpc_clnt *clnt4, 208 bool is_af_local) 209 { 210 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 211 212 /* Protected by rpcb_create_local_mutex */ 213 sn->rpcb_local_clnt = clnt; 214 sn->rpcb_local_clnt4 = clnt4; 215 sn->rpcb_is_af_local = is_af_local ? 1 : 0; 216 smp_wmb(); 217 sn->rpcb_users = 1; 218 } 219 220 /* Evaluate to actual length of the `sockaddr_un' structure. */ 221 # define SUN_LEN(ptr) (offsetof(struct sockaddr_un, sun_path) \ 222 + 1 + strlen((ptr)->sun_path + 1)) 223 224 /* 225 * Returns zero on success, otherwise a negative errno value 226 * is returned. 227 */ 228 static int rpcb_create_af_local(struct net *net, 229 const struct sockaddr_un *addr) 230 { 231 struct rpc_create_args args = { 232 .net = net, 233 .protocol = XPRT_TRANSPORT_LOCAL, 234 .address = (struct sockaddr *)addr, 235 .addrsize = SUN_LEN(addr), 236 .servername = "localhost", 237 .program = &rpcb_program, 238 .version = RPCBVERS_2, 239 .authflavor = RPC_AUTH_NULL, 240 .cred = current_cred(), 241 /* 242 * We turn off the idle timeout to prevent the kernel 243 * from automatically disconnecting the socket. 244 * Otherwise, we'd have to cache the mount namespace 245 * of the caller and somehow pass that to the socket 246 * reconnect code. 247 */ 248 .flags = RPC_CLNT_CREATE_NO_IDLE_TIMEOUT, 249 }; 250 struct rpc_clnt *clnt, *clnt4; 251 int result = 0; 252 253 /* 254 * Because we requested an RPC PING at transport creation time, 255 * this works only if the user space portmapper is rpcbind, and 256 * it's listening on AF_LOCAL on the named socket. 257 */ 258 clnt = rpc_create(&args); 259 if (IS_ERR(clnt)) { 260 result = PTR_ERR(clnt); 261 goto out; 262 } 263 264 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4); 265 if (IS_ERR(clnt4)) 266 clnt4 = NULL; 267 268 rpcb_set_local(net, clnt, clnt4, true); 269 270 out: 271 return result; 272 } 273 274 static int rpcb_create_local_abstract(struct net *net) 275 { 276 static const struct sockaddr_un rpcb_localaddr_abstract = { 277 .sun_family = AF_LOCAL, 278 .sun_path = RPCBIND_SOCK_ABSTRACT_NAME, 279 }; 280 281 return rpcb_create_af_local(net, &rpcb_localaddr_abstract); 282 } 283 284 static int rpcb_create_local_unix(struct net *net) 285 { 286 static const struct sockaddr_un rpcb_localaddr_unix = { 287 .sun_family = AF_LOCAL, 288 .sun_path = RPCBIND_SOCK_PATHNAME, 289 }; 290 291 return rpcb_create_af_local(net, &rpcb_localaddr_unix); 292 } 293 294 /* 295 * Returns zero on success, otherwise a negative errno value 296 * is returned. 297 */ 298 static int rpcb_create_local_net(struct net *net) 299 { 300 static const struct sockaddr_in rpcb_inaddr_loopback = { 301 .sin_family = AF_INET, 302 .sin_addr.s_addr = htonl(INADDR_LOOPBACK), 303 .sin_port = htons(RPCBIND_PORT), 304 }; 305 struct rpc_create_args args = { 306 .net = net, 307 .protocol = XPRT_TRANSPORT_TCP, 308 .address = (struct sockaddr *)&rpcb_inaddr_loopback, 309 .addrsize = sizeof(rpcb_inaddr_loopback), 310 .servername = "localhost", 311 .program = &rpcb_program, 312 .version = RPCBVERS_2, 313 .authflavor = RPC_AUTH_UNIX, 314 .cred = current_cred(), 315 .flags = RPC_CLNT_CREATE_NOPING, 316 }; 317 struct rpc_clnt *clnt, *clnt4; 318 int result = 0; 319 320 clnt = rpc_create(&args); 321 if (IS_ERR(clnt)) { 322 result = PTR_ERR(clnt); 323 goto out; 324 } 325 326 /* 327 * This results in an RPC ping. On systems running portmapper, 328 * the v4 ping will fail. Proceed anyway, but disallow rpcb 329 * v4 upcalls. 330 */ 331 clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4); 332 if (IS_ERR(clnt4)) 333 clnt4 = NULL; 334 335 rpcb_set_local(net, clnt, clnt4, false); 336 337 out: 338 return result; 339 } 340 341 /* 342 * Returns zero on success, otherwise a negative errno value 343 * is returned. 344 */ 345 int rpcb_create_local(struct net *net) 346 { 347 static DEFINE_MUTEX(rpcb_create_local_mutex); 348 int result = 0; 349 350 if (rpcb_get_local(net)) 351 return result; 352 353 mutex_lock(&rpcb_create_local_mutex); 354 if (rpcb_get_local(net)) 355 goto out; 356 357 if (rpcb_create_local_abstract(net) != 0 && 358 rpcb_create_local_unix(net) != 0) 359 result = rpcb_create_local_net(net); 360 361 out: 362 mutex_unlock(&rpcb_create_local_mutex); 363 return result; 364 } 365 366 static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename, 367 const char *hostname, 368 struct sockaddr *srvaddr, size_t salen, 369 int proto, u32 version, 370 const struct cred *cred, 371 const struct rpc_timeout *timeo) 372 { 373 struct rpc_create_args args = { 374 .net = net, 375 .protocol = proto, 376 .address = srvaddr, 377 .addrsize = salen, 378 .timeout = timeo, 379 .servername = hostname, 380 .nodename = nodename, 381 .program = &rpcb_program, 382 .version = version, 383 .authflavor = RPC_AUTH_UNIX, 384 .cred = cred, 385 .flags = (RPC_CLNT_CREATE_NOPING | 386 RPC_CLNT_CREATE_NONPRIVPORT), 387 }; 388 389 switch (srvaddr->sa_family) { 390 case AF_INET: 391 ((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT); 392 break; 393 case AF_INET6: 394 ((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT); 395 break; 396 default: 397 return ERR_PTR(-EAFNOSUPPORT); 398 } 399 400 return rpc_create(&args); 401 } 402 403 static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set) 404 { 405 int flags = RPC_TASK_NOCONNECT; 406 int error, result = 0; 407 408 if (is_set || !sn->rpcb_is_af_local) 409 flags = RPC_TASK_SOFTCONN; 410 msg->rpc_resp = &result; 411 412 error = rpc_call_sync(clnt, msg, flags); 413 if (error < 0) 414 return error; 415 416 if (!result) 417 return -EACCES; 418 return 0; 419 } 420 421 /** 422 * rpcb_register - set or unset a port registration with the local rpcbind svc 423 * @net: target network namespace 424 * @prog: RPC program number to bind 425 * @vers: RPC version number to bind 426 * @prot: transport protocol to register 427 * @port: port value to register 428 * 429 * Returns zero if the registration request was dispatched successfully 430 * and the rpcbind daemon returned success. Otherwise, returns an errno 431 * value that reflects the nature of the error (request could not be 432 * dispatched, timed out, or rpcbind returned an error). 433 * 434 * RPC services invoke this function to advertise their contact 435 * information via the system's rpcbind daemon. RPC services 436 * invoke this function once for each [program, version, transport] 437 * tuple they wish to advertise. 438 * 439 * Callers may also unregister RPC services that are no longer 440 * available by setting the passed-in port to zero. This removes 441 * all registered transports for [program, version] from the local 442 * rpcbind database. 443 * 444 * This function uses rpcbind protocol version 2 to contact the 445 * local rpcbind daemon. 446 * 447 * Registration works over both AF_INET and AF_INET6, and services 448 * registered via this function are advertised as available for any 449 * address. If the local rpcbind daemon is listening on AF_INET6, 450 * services registered via this function will be advertised on 451 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6 452 * addresses). 453 */ 454 int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port) 455 { 456 struct rpcbind_args map = { 457 .r_prog = prog, 458 .r_vers = vers, 459 .r_prot = prot, 460 .r_port = port, 461 }; 462 struct rpc_message msg = { 463 .rpc_argp = &map, 464 }; 465 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 466 bool is_set = false; 467 468 trace_pmap_register(prog, vers, prot, port); 469 470 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET]; 471 if (port != 0) { 472 msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET]; 473 is_set = true; 474 } 475 476 return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set); 477 } 478 479 /* 480 * Fill in AF_INET family-specific arguments to register 481 */ 482 static int rpcb_register_inet4(struct sunrpc_net *sn, 483 const struct sockaddr *sap, 484 struct rpc_message *msg) 485 { 486 const struct sockaddr_in *sin = (const struct sockaddr_in *)sap; 487 struct rpcbind_args *map = msg->rpc_argp; 488 unsigned short port = ntohs(sin->sin_port); 489 bool is_set = false; 490 int result; 491 492 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); 493 if (!map->r_addr) 494 return -ENOMEM; 495 496 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 497 if (port != 0) { 498 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET]; 499 is_set = true; 500 } 501 502 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set); 503 kfree(map->r_addr); 504 return result; 505 } 506 507 /* 508 * Fill in AF_INET6 family-specific arguments to register 509 */ 510 static int rpcb_register_inet6(struct sunrpc_net *sn, 511 const struct sockaddr *sap, 512 struct rpc_message *msg) 513 { 514 const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap; 515 struct rpcbind_args *map = msg->rpc_argp; 516 unsigned short port = ntohs(sin6->sin6_port); 517 bool is_set = false; 518 int result; 519 520 map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL); 521 if (!map->r_addr) 522 return -ENOMEM; 523 524 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 525 if (port != 0) { 526 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET]; 527 is_set = true; 528 } 529 530 result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set); 531 kfree(map->r_addr); 532 return result; 533 } 534 535 static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn, 536 struct rpc_message *msg) 537 { 538 struct rpcbind_args *map = msg->rpc_argp; 539 540 trace_rpcb_unregister(map->r_prog, map->r_vers, map->r_netid); 541 542 map->r_addr = ""; 543 msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET]; 544 545 return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false); 546 } 547 548 /** 549 * rpcb_v4_register - set or unset a port registration with the local rpcbind 550 * @net: target network namespace 551 * @program: RPC program number of service to (un)register 552 * @version: RPC version number of service to (un)register 553 * @address: address family, IP address, and port to (un)register 554 * @netid: netid of transport protocol to (un)register 555 * 556 * Returns zero if the registration request was dispatched successfully 557 * and the rpcbind daemon returned success. Otherwise, returns an errno 558 * value that reflects the nature of the error (request could not be 559 * dispatched, timed out, or rpcbind returned an error). 560 * 561 * RPC services invoke this function to advertise their contact 562 * information via the system's rpcbind daemon. RPC services 563 * invoke this function once for each [program, version, address, 564 * netid] tuple they wish to advertise. 565 * 566 * Callers may also unregister RPC services that are registered at a 567 * specific address by setting the port number in @address to zero. 568 * They may unregister all registered protocol families at once for 569 * a service by passing a NULL @address argument. If @netid is "" 570 * then all netids for [program, version, address] are unregistered. 571 * 572 * This function uses rpcbind protocol version 4 to contact the 573 * local rpcbind daemon. The local rpcbind daemon must support 574 * version 4 of the rpcbind protocol in order for these functions 575 * to register a service successfully. 576 * 577 * Supported netids include "udp" and "tcp" for UDP and TCP over 578 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6, 579 * respectively. 580 * 581 * The contents of @address determine the address family and the 582 * port to be registered. The usual practice is to pass INADDR_ANY 583 * as the raw address, but specifying a non-zero address is also 584 * supported by this API if the caller wishes to advertise an RPC 585 * service on a specific network interface. 586 * 587 * Note that passing in INADDR_ANY does not create the same service 588 * registration as IN6ADDR_ANY. The former advertises an RPC 589 * service on any IPv4 address, but not on IPv6. The latter 590 * advertises the service on all IPv4 and IPv6 addresses. 591 */ 592 int rpcb_v4_register(struct net *net, const u32 program, const u32 version, 593 const struct sockaddr *address, const char *netid) 594 { 595 struct rpcbind_args map = { 596 .r_prog = program, 597 .r_vers = version, 598 .r_netid = netid, 599 .r_owner = RPCB_OWNER_STRING, 600 }; 601 struct rpc_message msg = { 602 .rpc_argp = &map, 603 }; 604 struct sunrpc_net *sn = net_generic(net, sunrpc_net_id); 605 606 if (sn->rpcb_local_clnt4 == NULL) 607 return -EPROTONOSUPPORT; 608 609 if (address == NULL) 610 return rpcb_unregister_all_protofamilies(sn, &msg); 611 612 trace_rpcb_register(map.r_prog, map.r_vers, map.r_addr, map.r_netid); 613 614 switch (address->sa_family) { 615 case AF_INET: 616 return rpcb_register_inet4(sn, address, &msg); 617 case AF_INET6: 618 return rpcb_register_inet6(sn, address, &msg); 619 } 620 621 return -EAFNOSUPPORT; 622 } 623 624 static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, 625 struct rpcbind_args *map, const struct rpc_procinfo *proc) 626 { 627 struct rpc_message msg = { 628 .rpc_proc = proc, 629 .rpc_argp = map, 630 .rpc_resp = map, 631 }; 632 struct rpc_task_setup task_setup_data = { 633 .rpc_client = rpcb_clnt, 634 .rpc_message = &msg, 635 .callback_ops = &rpcb_getport_ops, 636 .callback_data = map, 637 .flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN, 638 }; 639 640 return rpc_run_task(&task_setup_data); 641 } 642 643 /* 644 * In the case where rpc clients have been cloned, we want to make 645 * sure that we use the program number/version etc of the actual 646 * owner of the xprt. To do so, we walk back up the tree of parents 647 * to find whoever created the transport and/or whoever has the 648 * autobind flag set. 649 */ 650 static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt) 651 { 652 struct rpc_clnt *parent = clnt->cl_parent; 653 struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch); 654 655 while (parent != clnt) { 656 if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps) 657 break; 658 if (clnt->cl_autobind) 659 break; 660 clnt = parent; 661 parent = parent->cl_parent; 662 } 663 return clnt; 664 } 665 666 /** 667 * rpcb_getport_async - obtain the port for a given RPC service on a given host 668 * @task: task that is waiting for portmapper request 669 * 670 * This one can be called for an ongoing RPC request, and can be used in 671 * an async (rpciod) context. 672 */ 673 void rpcb_getport_async(struct rpc_task *task) 674 { 675 struct rpc_clnt *clnt; 676 const struct rpc_procinfo *proc; 677 u32 bind_version; 678 struct rpc_xprt *xprt; 679 struct rpc_clnt *rpcb_clnt; 680 struct rpcbind_args *map; 681 struct rpc_task *child; 682 struct sockaddr_storage addr; 683 struct sockaddr *sap = (struct sockaddr *)&addr; 684 size_t salen; 685 int status; 686 687 rcu_read_lock(); 688 clnt = rpcb_find_transport_owner(task->tk_client); 689 rcu_read_unlock(); 690 xprt = xprt_get(task->tk_xprt); 691 692 /* Put self on the wait queue to ensure we get notified if 693 * some other task is already attempting to bind the port */ 694 rpc_sleep_on_timeout(&xprt->binding, task, 695 NULL, jiffies + xprt->bind_timeout); 696 697 if (xprt_test_and_set_binding(xprt)) { 698 xprt_put(xprt); 699 return; 700 } 701 702 /* Someone else may have bound if we slept */ 703 if (xprt_bound(xprt)) { 704 status = 0; 705 goto bailout_nofree; 706 } 707 708 /* Parent transport's destination address */ 709 salen = rpc_peeraddr(clnt, sap, sizeof(addr)); 710 711 /* Don't ever use rpcbind v2 for AF_INET6 requests */ 712 switch (sap->sa_family) { 713 case AF_INET: 714 proc = rpcb_next_version[xprt->bind_index].rpc_proc; 715 bind_version = rpcb_next_version[xprt->bind_index].rpc_vers; 716 break; 717 case AF_INET6: 718 proc = rpcb_next_version6[xprt->bind_index].rpc_proc; 719 bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers; 720 break; 721 default: 722 status = -EAFNOSUPPORT; 723 goto bailout_nofree; 724 } 725 if (proc == NULL) { 726 xprt->bind_index = 0; 727 status = -EPFNOSUPPORT; 728 goto bailout_nofree; 729 } 730 731 trace_rpcb_getport(clnt, task, bind_version); 732 733 rpcb_clnt = rpcb_create(xprt->xprt_net, 734 clnt->cl_nodename, 735 xprt->servername, sap, salen, 736 xprt->prot, bind_version, 737 clnt->cl_cred, 738 task->tk_client->cl_timeout); 739 if (IS_ERR(rpcb_clnt)) { 740 status = PTR_ERR(rpcb_clnt); 741 goto bailout_nofree; 742 } 743 744 map = kzalloc_obj(struct rpcbind_args, rpc_task_gfp_mask()); 745 if (!map) { 746 status = -ENOMEM; 747 goto bailout_release_client; 748 } 749 map->r_prog = clnt->cl_prog; 750 map->r_vers = clnt->cl_vers; 751 map->r_prot = xprt->prot; 752 map->r_port = 0; 753 map->r_xprt = xprt; 754 map->r_status = -EIO; 755 756 switch (bind_version) { 757 case RPCBVERS_4: 758 case RPCBVERS_3: 759 map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID]; 760 map->r_addr = rpc_sockaddr2uaddr(sap, rpc_task_gfp_mask()); 761 if (!map->r_addr) { 762 status = -ENOMEM; 763 goto bailout_free_args; 764 } 765 map->r_owner = ""; 766 break; 767 case RPCBVERS_2: 768 map->r_addr = NULL; 769 break; 770 default: 771 BUG(); 772 } 773 774 child = rpcb_call_async(rpcb_clnt, map, proc); 775 rpc_release_client(rpcb_clnt); 776 if (IS_ERR(child)) { 777 /* rpcb_map_release() has freed the arguments */ 778 return; 779 } 780 781 xprt->stat.bind_count++; 782 rpc_put_task(child); 783 return; 784 785 bailout_free_args: 786 kfree(map); 787 bailout_release_client: 788 rpc_release_client(rpcb_clnt); 789 bailout_nofree: 790 rpcb_wake_rpcbind_waiters(xprt, status); 791 task->tk_status = status; 792 xprt_put(xprt); 793 } 794 EXPORT_SYMBOL_GPL(rpcb_getport_async); 795 796 /* 797 * Rpcbind child task calls this callback via tk_exit. 798 */ 799 static void rpcb_getport_done(struct rpc_task *child, void *data) 800 { 801 struct rpcbind_args *map = data; 802 struct rpc_xprt *xprt = map->r_xprt; 803 804 map->r_status = child->tk_status; 805 806 /* Garbage reply: retry with a lesser rpcbind version */ 807 if (map->r_status == -EIO) 808 map->r_status = -EPROTONOSUPPORT; 809 810 /* rpcbind server doesn't support this rpcbind protocol version */ 811 if (map->r_status == -EPROTONOSUPPORT) 812 xprt->bind_index++; 813 814 if (map->r_status < 0) { 815 /* rpcbind server not available on remote host? */ 816 map->r_port = 0; 817 818 } else if (map->r_port == 0) { 819 /* Requested RPC service wasn't registered on remote host */ 820 map->r_status = -EACCES; 821 } else { 822 /* Succeeded */ 823 map->r_status = 0; 824 } 825 826 trace_rpcb_setport(child, map->r_status, map->r_port); 827 if (map->r_port) { 828 xprt->ops->set_port(xprt, map->r_port); 829 xprt_set_bound(xprt); 830 } 831 } 832 833 /* 834 * XDR functions for rpcbind 835 */ 836 837 static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr, 838 const void *data) 839 { 840 const struct rpcbind_args *rpcb = data; 841 __be32 *p; 842 843 p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2); 844 *p++ = cpu_to_be32(rpcb->r_prog); 845 *p++ = cpu_to_be32(rpcb->r_vers); 846 *p++ = cpu_to_be32(rpcb->r_prot); 847 *p = cpu_to_be32(rpcb->r_port); 848 } 849 850 static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr, 851 void *data) 852 { 853 struct rpcbind_args *rpcb = data; 854 unsigned long port; 855 __be32 *p; 856 857 rpcb->r_port = 0; 858 859 p = xdr_inline_decode(xdr, 4); 860 if (unlikely(p == NULL)) 861 return -EIO; 862 863 port = be32_to_cpup(p); 864 if (unlikely(port > USHRT_MAX)) 865 return -EIO; 866 867 rpcb->r_port = port; 868 return 0; 869 } 870 871 static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr, 872 void *data) 873 { 874 unsigned int *boolp = data; 875 __be32 *p; 876 877 p = xdr_inline_decode(xdr, 4); 878 if (unlikely(p == NULL)) 879 return -EIO; 880 881 *boolp = 0; 882 if (*p != xdr_zero) 883 *boolp = 1; 884 return 0; 885 } 886 887 static void encode_rpcb_string(struct xdr_stream *xdr, const char *string, 888 const u32 maxstrlen) 889 { 890 __be32 *p; 891 u32 len; 892 893 len = strlen(string); 894 WARN_ON_ONCE(len > maxstrlen); 895 if (len > maxstrlen) 896 /* truncate and hope for the best */ 897 len = maxstrlen; 898 p = xdr_reserve_space(xdr, 4 + len); 899 xdr_encode_opaque(p, string, len); 900 } 901 902 static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr, 903 const void *data) 904 { 905 const struct rpcbind_args *rpcb = data; 906 __be32 *p; 907 908 p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2); 909 *p++ = cpu_to_be32(rpcb->r_prog); 910 *p = cpu_to_be32(rpcb->r_vers); 911 912 encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN); 913 encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN); 914 encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN); 915 } 916 917 static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr, 918 void *data) 919 { 920 struct rpcbind_args *rpcb = data; 921 struct sockaddr_storage address; 922 struct sockaddr *sap = (struct sockaddr *)&address; 923 __be32 *p; 924 u32 len; 925 926 rpcb->r_port = 0; 927 928 p = xdr_inline_decode(xdr, 4); 929 if (unlikely(p == NULL)) 930 goto out_fail; 931 len = be32_to_cpup(p); 932 933 /* 934 * If the returned universal address is a null string, 935 * the requested RPC service was not registered. 936 */ 937 if (len == 0) 938 return 0; 939 940 if (unlikely(len > RPCBIND_MAXUADDRLEN)) 941 goto out_fail; 942 943 p = xdr_inline_decode(xdr, len); 944 if (unlikely(p == NULL)) 945 goto out_fail; 946 947 if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len, 948 sap, sizeof(address)) == 0) 949 goto out_fail; 950 rpcb->r_port = rpc_get_port(sap); 951 952 return 0; 953 954 out_fail: 955 return -EIO; 956 } 957 958 /* 959 * Not all rpcbind procedures described in RFC 1833 are implemented 960 * since the Linux kernel RPC code requires only these. 961 */ 962 963 static const struct rpc_procinfo rpcb_procedures2[] = { 964 [RPCBPROC_SET] = { 965 .p_proc = RPCBPROC_SET, 966 .p_encode = rpcb_enc_mapping, 967 .p_decode = rpcb_dec_set, 968 .p_arglen = RPCB_mappingargs_sz, 969 .p_replen = RPCB_setres_sz, 970 .p_statidx = RPCBPROC_SET, 971 .p_timer = 0, 972 .p_name = "SET", 973 }, 974 [RPCBPROC_UNSET] = { 975 .p_proc = RPCBPROC_UNSET, 976 .p_encode = rpcb_enc_mapping, 977 .p_decode = rpcb_dec_set, 978 .p_arglen = RPCB_mappingargs_sz, 979 .p_replen = RPCB_setres_sz, 980 .p_statidx = RPCBPROC_UNSET, 981 .p_timer = 0, 982 .p_name = "UNSET", 983 }, 984 [RPCBPROC_GETPORT] = { 985 .p_proc = RPCBPROC_GETPORT, 986 .p_encode = rpcb_enc_mapping, 987 .p_decode = rpcb_dec_getport, 988 .p_arglen = RPCB_mappingargs_sz, 989 .p_replen = RPCB_getportres_sz, 990 .p_statidx = RPCBPROC_GETPORT, 991 .p_timer = 0, 992 .p_name = "GETPORT", 993 }, 994 }; 995 996 static const struct rpc_procinfo rpcb_procedures3[] = { 997 [RPCBPROC_SET] = { 998 .p_proc = RPCBPROC_SET, 999 .p_encode = rpcb_enc_getaddr, 1000 .p_decode = rpcb_dec_set, 1001 .p_arglen = RPCB_getaddrargs_sz, 1002 .p_replen = RPCB_setres_sz, 1003 .p_statidx = RPCBPROC_SET, 1004 .p_timer = 0, 1005 .p_name = "SET", 1006 }, 1007 [RPCBPROC_UNSET] = { 1008 .p_proc = RPCBPROC_UNSET, 1009 .p_encode = rpcb_enc_getaddr, 1010 .p_decode = rpcb_dec_set, 1011 .p_arglen = RPCB_getaddrargs_sz, 1012 .p_replen = RPCB_setres_sz, 1013 .p_statidx = RPCBPROC_UNSET, 1014 .p_timer = 0, 1015 .p_name = "UNSET", 1016 }, 1017 [RPCBPROC_GETADDR] = { 1018 .p_proc = RPCBPROC_GETADDR, 1019 .p_encode = rpcb_enc_getaddr, 1020 .p_decode = rpcb_dec_getaddr, 1021 .p_arglen = RPCB_getaddrargs_sz, 1022 .p_replen = RPCB_getaddrres_sz, 1023 .p_statidx = RPCBPROC_GETADDR, 1024 .p_timer = 0, 1025 .p_name = "GETADDR", 1026 }, 1027 }; 1028 1029 static const struct rpc_procinfo rpcb_procedures4[] = { 1030 [RPCBPROC_SET] = { 1031 .p_proc = RPCBPROC_SET, 1032 .p_encode = rpcb_enc_getaddr, 1033 .p_decode = rpcb_dec_set, 1034 .p_arglen = RPCB_getaddrargs_sz, 1035 .p_replen = RPCB_setres_sz, 1036 .p_statidx = RPCBPROC_SET, 1037 .p_timer = 0, 1038 .p_name = "SET", 1039 }, 1040 [RPCBPROC_UNSET] = { 1041 .p_proc = RPCBPROC_UNSET, 1042 .p_encode = rpcb_enc_getaddr, 1043 .p_decode = rpcb_dec_set, 1044 .p_arglen = RPCB_getaddrargs_sz, 1045 .p_replen = RPCB_setres_sz, 1046 .p_statidx = RPCBPROC_UNSET, 1047 .p_timer = 0, 1048 .p_name = "UNSET", 1049 }, 1050 [RPCBPROC_GETADDR] = { 1051 .p_proc = RPCBPROC_GETADDR, 1052 .p_encode = rpcb_enc_getaddr, 1053 .p_decode = rpcb_dec_getaddr, 1054 .p_arglen = RPCB_getaddrargs_sz, 1055 .p_replen = RPCB_getaddrres_sz, 1056 .p_statidx = RPCBPROC_GETADDR, 1057 .p_timer = 0, 1058 .p_name = "GETADDR", 1059 }, 1060 }; 1061 1062 static const struct rpcb_info rpcb_next_version[] = { 1063 { 1064 .rpc_vers = RPCBVERS_2, 1065 .rpc_proc = &rpcb_procedures2[RPCBPROC_GETPORT], 1066 }, 1067 { 1068 .rpc_proc = NULL, 1069 }, 1070 }; 1071 1072 static const struct rpcb_info rpcb_next_version6[] = { 1073 { 1074 .rpc_vers = RPCBVERS_4, 1075 .rpc_proc = &rpcb_procedures4[RPCBPROC_GETADDR], 1076 }, 1077 { 1078 .rpc_vers = RPCBVERS_3, 1079 .rpc_proc = &rpcb_procedures3[RPCBPROC_GETADDR], 1080 }, 1081 { 1082 .rpc_proc = NULL, 1083 }, 1084 }; 1085 1086 static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)]; 1087 static const struct rpc_version rpcb_version2 = { 1088 .number = RPCBVERS_2, 1089 .nrprocs = ARRAY_SIZE(rpcb_procedures2), 1090 .procs = rpcb_procedures2, 1091 .counts = rpcb_version2_counts, 1092 }; 1093 1094 static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)]; 1095 static const struct rpc_version rpcb_version3 = { 1096 .number = RPCBVERS_3, 1097 .nrprocs = ARRAY_SIZE(rpcb_procedures3), 1098 .procs = rpcb_procedures3, 1099 .counts = rpcb_version3_counts, 1100 }; 1101 1102 static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)]; 1103 static const struct rpc_version rpcb_version4 = { 1104 .number = RPCBVERS_4, 1105 .nrprocs = ARRAY_SIZE(rpcb_procedures4), 1106 .procs = rpcb_procedures4, 1107 .counts = rpcb_version4_counts, 1108 }; 1109 1110 static const struct rpc_version *rpcb_version[] = { 1111 NULL, 1112 NULL, 1113 &rpcb_version2, 1114 &rpcb_version3, 1115 &rpcb_version4 1116 }; 1117 1118 static struct rpc_stat rpcb_stats; 1119 1120 static const struct rpc_program rpcb_program = { 1121 .name = "rpcbind", 1122 .number = RPCBIND_PROGRAM, 1123 .nrvers = ARRAY_SIZE(rpcb_version), 1124 .version = rpcb_version, 1125 .stats = &rpcb_stats, 1126 }; 1127