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 "netns.h"
  35
  36#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  37# define RPCDBG_FACILITY	RPCDBG_BIND
  38#endif
  39
  40#define RPCBIND_SOCK_PATHNAME	"/var/run/rpcbind.sock"
  41
  42#define RPCBIND_PROGRAM		(100000u)
  43#define RPCBIND_PORT		(111u)
  44
  45#define RPCBVERS_2		(2u)
  46#define RPCBVERS_3		(3u)
  47#define RPCBVERS_4		(4u)
  48
  49enum {
  50	RPCBPROC_NULL,
  51	RPCBPROC_SET,
  52	RPCBPROC_UNSET,
  53	RPCBPROC_GETPORT,
  54	RPCBPROC_GETADDR = 3,		/* alias for GETPORT */
  55	RPCBPROC_DUMP,
  56	RPCBPROC_CALLIT,
  57	RPCBPROC_BCAST = 5,		/* alias for CALLIT */
  58	RPCBPROC_GETTIME,
  59	RPCBPROC_UADDR2TADDR,
  60	RPCBPROC_TADDR2UADDR,
  61	RPCBPROC_GETVERSADDR,
  62	RPCBPROC_INDIRECT,
  63	RPCBPROC_GETADDRLIST,
  64	RPCBPROC_GETSTAT,
  65};
  66
  67/*
  68 * r_owner
  69 *
  70 * The "owner" is allowed to unset a service in the rpcbind database.
  71 *
  72 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
  73 * UID which it maps to a local user name via a password lookup.
  74 * In all other cases it is ignored.
  75 *
  76 * For SET/UNSET requests, user space provides a value, even for
  77 * network requests, and GETADDR uses an empty string.  We follow
  78 * those precedents here.
  79 */
  80#define RPCB_OWNER_STRING	"0"
  81#define RPCB_MAXOWNERLEN	sizeof(RPCB_OWNER_STRING)
  82
  83/*
  84 * XDR data type sizes
  85 */
  86#define RPCB_program_sz		(1)
  87#define RPCB_version_sz		(1)
  88#define RPCB_protocol_sz	(1)
  89#define RPCB_port_sz		(1)
  90#define RPCB_boolean_sz		(1)
  91
  92#define RPCB_netid_sz		(1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
  93#define RPCB_addr_sz		(1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
  94#define RPCB_ownerstring_sz	(1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))
  95
  96/*
  97 * XDR argument and result sizes
  98 */
  99#define RPCB_mappingargs_sz	(RPCB_program_sz + RPCB_version_sz + \
 100				RPCB_protocol_sz + RPCB_port_sz)
 101#define RPCB_getaddrargs_sz	(RPCB_program_sz + RPCB_version_sz + \
 102				RPCB_netid_sz + RPCB_addr_sz + \
 103				RPCB_ownerstring_sz)
 104
 105#define RPCB_getportres_sz	RPCB_port_sz
 106#define RPCB_setres_sz		RPCB_boolean_sz
 107
 108/*
 109 * Note that RFC 1833 does not put any size restrictions on the
 110 * address string returned by the remote rpcbind database.
 111 */
 112#define RPCB_getaddrres_sz	RPCB_addr_sz
 113
 114static void			rpcb_getport_done(struct rpc_task *, void *);
 115static void			rpcb_map_release(void *data);
 116static const struct rpc_program	rpcb_program;
 117
 118struct rpcbind_args {
 119	struct rpc_xprt *	r_xprt;
 120
 121	u32			r_prog;
 122	u32			r_vers;
 123	u32			r_prot;
 124	unsigned short		r_port;
 125	const char *		r_netid;
 126	const char *		r_addr;
 127	const char *		r_owner;
 128
 129	int			r_status;
 130};
 131
 132static const struct rpc_procinfo rpcb_procedures2[];
 133static const struct rpc_procinfo rpcb_procedures3[];
 134static const struct rpc_procinfo rpcb_procedures4[];
 135
 136struct rpcb_info {
 137	u32			rpc_vers;
 138	const struct rpc_procinfo *rpc_proc;
 139};
 140
 141static const struct rpcb_info rpcb_next_version[];
 142static const struct rpcb_info rpcb_next_version6[];
 143
 144static const struct rpc_call_ops rpcb_getport_ops = {
 145	.rpc_call_done		= rpcb_getport_done,
 146	.rpc_release		= rpcb_map_release,
 147};
 148
 149static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
 150{
 151	xprt_clear_binding(xprt);
 152	rpc_wake_up_status(&xprt->binding, status);
 153}
 154
 155static void rpcb_map_release(void *data)
 156{
 157	struct rpcbind_args *map = data;
 158
 159	rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
 160	xprt_put(map->r_xprt);
 161	kfree(map->r_addr);
 162	kfree(map);
 163}
 164
 165static int rpcb_get_local(struct net *net)
 166{
 167	int cnt;
 168	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 169
 170	spin_lock(&sn->rpcb_clnt_lock);
 171	if (sn->rpcb_users)
 172		sn->rpcb_users++;
 173	cnt = sn->rpcb_users;
 174	spin_unlock(&sn->rpcb_clnt_lock);
 175
 176	return cnt;
 177}
 178
 179void rpcb_put_local(struct net *net)
 180{
 181	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 182	struct rpc_clnt *clnt = sn->rpcb_local_clnt;
 183	struct rpc_clnt *clnt4 = sn->rpcb_local_clnt4;
 184	int shutdown = 0;
 185
 186	spin_lock(&sn->rpcb_clnt_lock);
 187	if (sn->rpcb_users) {
 188		if (--sn->rpcb_users == 0) {
 189			sn->rpcb_local_clnt = NULL;
 190			sn->rpcb_local_clnt4 = NULL;
 191		}
 192		shutdown = !sn->rpcb_users;
 193	}
 194	spin_unlock(&sn->rpcb_clnt_lock);
 195
 196	if (shutdown) {
 197		/*
 198		 * cleanup_rpcb_clnt - remove xprtsock's sysctls, unregister
 199		 */
 200		if (clnt4)
 201			rpc_shutdown_client(clnt4);
 202		if (clnt)
 203			rpc_shutdown_client(clnt);
 204	}
 205}
 206
 207static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
 208			struct rpc_clnt *clnt4,
 209			bool is_af_local)
 210{
 211	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 212
 213	/* Protected by rpcb_create_local_mutex */
 214	sn->rpcb_local_clnt = clnt;
 215	sn->rpcb_local_clnt4 = clnt4;
 216	sn->rpcb_is_af_local = is_af_local ? 1 : 0;
 217	smp_wmb();
 218	sn->rpcb_users = 1;
 219	dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 220		"%p, rpcb_local_clnt4: %p) for net %x%s\n",
 221		sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 222		net->ns.inum, (net == &init_net) ? " (init_net)" : "");
 223}
 224
 225/*
 226 * Returns zero on success, otherwise a negative errno value
 227 * is returned.
 228 */
 229static int rpcb_create_local_unix(struct net *net)
 230{
 231	static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 232		.sun_family		= AF_LOCAL,
 233		.sun_path		= RPCBIND_SOCK_PATHNAME,
 234	};
 235	struct rpc_create_args args = {
 236		.net		= net,
 237		.protocol	= XPRT_TRANSPORT_LOCAL,
 238		.address	= (struct sockaddr *)&rpcb_localaddr_rpcbind,
 239		.addrsize	= sizeof(rpcb_localaddr_rpcbind),
 240		.servername	= "localhost",
 241		.program	= &rpcb_program,
 242		.version	= RPCBVERS_2,
 243		.authflavor	= RPC_AUTH_NULL,
 244		.cred		= current_cred(),
 245		/*
 246		 * We turn off the idle timeout to prevent the kernel
 247		 * from automatically disconnecting the socket.
 248		 * Otherwise, we'd have to cache the mount namespace
 249		 * of the caller and somehow pass that to the socket
 250		 * reconnect code.
 251		 */
 252		.flags		= RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
 253	};
 254	struct rpc_clnt *clnt, *clnt4;
 255	int result = 0;
 256
 257	/*
 258	 * Because we requested an RPC PING at transport creation time,
 259	 * this works only if the user space portmapper is rpcbind, and
 260	 * it's listening on AF_LOCAL on the named socket.
 261	 */
 262	clnt = rpc_create(&args);
 263	if (IS_ERR(clnt)) {
 264		dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 265				"client (errno %ld).\n", PTR_ERR(clnt));
 266		result = PTR_ERR(clnt);
 267		goto out;
 268	}
 269
 270	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 271	if (IS_ERR(clnt4)) {
 272		dprintk("RPC:       failed to bind second program to "
 273				"rpcbind v4 client (errno %ld).\n",
 274				PTR_ERR(clnt4));
 275		clnt4 = NULL;
 276	}
 277
 278	rpcb_set_local(net, clnt, clnt4, true);
 279
 280out:
 281	return result;
 282}
 283
 284/*
 285 * Returns zero on success, otherwise a negative errno value
 286 * is returned.
 287 */
 288static int rpcb_create_local_net(struct net *net)
 289{
 290	static const struct sockaddr_in rpcb_inaddr_loopback = {
 291		.sin_family		= AF_INET,
 292		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
 293		.sin_port		= htons(RPCBIND_PORT),
 294	};
 295	struct rpc_create_args args = {
 296		.net		= net,
 297		.protocol	= XPRT_TRANSPORT_TCP,
 298		.address	= (struct sockaddr *)&rpcb_inaddr_loopback,
 299		.addrsize	= sizeof(rpcb_inaddr_loopback),
 300		.servername	= "localhost",
 301		.program	= &rpcb_program,
 302		.version	= RPCBVERS_2,
 303		.authflavor	= RPC_AUTH_UNIX,
 304		.cred		= current_cred(),
 305		.flags		= RPC_CLNT_CREATE_NOPING,
 306	};
 307	struct rpc_clnt *clnt, *clnt4;
 308	int result = 0;
 309
 310	clnt = rpc_create(&args);
 311	if (IS_ERR(clnt)) {
 312		dprintk("RPC:       failed to create local rpcbind "
 313				"client (errno %ld).\n", PTR_ERR(clnt));
 314		result = PTR_ERR(clnt);
 315		goto out;
 316	}
 317
 318	/*
 319	 * This results in an RPC ping.  On systems running portmapper,
 320	 * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 321	 * v4 upcalls.
 322	 */
 323	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 324	if (IS_ERR(clnt4)) {
 325		dprintk("RPC:       failed to bind second program to "
 326				"rpcbind v4 client (errno %ld).\n",
 327				PTR_ERR(clnt4));
 328		clnt4 = NULL;
 329	}
 330
 331	rpcb_set_local(net, clnt, clnt4, false);
 332
 333out:
 334	return result;
 335}
 336
 337/*
 338 * Returns zero on success, otherwise a negative errno value
 339 * is returned.
 340 */
 341int rpcb_create_local(struct net *net)
 342{
 343	static DEFINE_MUTEX(rpcb_create_local_mutex);
 344	int result = 0;
 345
 346	if (rpcb_get_local(net))
 347		return result;
 348
 349	mutex_lock(&rpcb_create_local_mutex);
 350	if (rpcb_get_local(net))
 351		goto out;
 352
 353	if (rpcb_create_local_unix(net) != 0)
 354		result = rpcb_create_local_net(net);
 355
 356out:
 357	mutex_unlock(&rpcb_create_local_mutex);
 358	return result;
 359}
 360
 361static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
 362				    const char *hostname,
 363				    struct sockaddr *srvaddr, size_t salen,
 364				    int proto, u32 version,
 365				    const struct cred *cred)
 366{
 367	struct rpc_create_args args = {
 368		.net		= net,
 369		.protocol	= proto,
 370		.address	= srvaddr,
 371		.addrsize	= salen,
 372		.servername	= hostname,
 373		.nodename	= nodename,
 374		.program	= &rpcb_program,
 375		.version	= version,
 376		.authflavor	= RPC_AUTH_UNIX,
 377		.cred		= cred,
 378		.flags		= (RPC_CLNT_CREATE_NOPING |
 379					RPC_CLNT_CREATE_NONPRIVPORT),
 380	};
 381
 382	switch (srvaddr->sa_family) {
 383	case AF_INET:
 384		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 385		break;
 386	case AF_INET6:
 387		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 388		break;
 389	default:
 390		return ERR_PTR(-EAFNOSUPPORT);
 391	}
 392
 393	return rpc_create(&args);
 394}
 395
 396static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
 397{
 398	int flags = RPC_TASK_NOCONNECT;
 399	int error, result = 0;
 400
 401	if (is_set || !sn->rpcb_is_af_local)
 402		flags = RPC_TASK_SOFTCONN;
 403	msg->rpc_resp = &result;
 404
 405	error = rpc_call_sync(clnt, msg, flags);
 406	if (error < 0) {
 407		dprintk("RPC:       failed to contact local rpcbind "
 408				"server (errno %d).\n", -error);
 409		return error;
 410	}
 411
 412	if (!result)
 413		return -EACCES;
 414	return 0;
 415}
 416
 417/**
 418 * rpcb_register - set or unset a port registration with the local rpcbind svc
 419 * @net: target network namespace
 420 * @prog: RPC program number to bind
 421 * @vers: RPC version number to bind
 422 * @prot: transport protocol to register
 423 * @port: port value to register
 424 *
 425 * Returns zero if the registration request was dispatched successfully
 426 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 427 * value that reflects the nature of the error (request could not be
 428 * dispatched, timed out, or rpcbind returned an error).
 429 *
 430 * RPC services invoke this function to advertise their contact
 431 * information via the system's rpcbind daemon.  RPC services
 432 * invoke this function once for each [program, version, transport]
 433 * tuple they wish to advertise.
 434 *
 435 * Callers may also unregister RPC services that are no longer
 436 * available by setting the passed-in port to zero.  This removes
 437 * all registered transports for [program, version] from the local
 438 * rpcbind database.
 439 *
 440 * This function uses rpcbind protocol version 2 to contact the
 441 * local rpcbind daemon.
 442 *
 443 * Registration works over both AF_INET and AF_INET6, and services
 444 * registered via this function are advertised as available for any
 445 * address.  If the local rpcbind daemon is listening on AF_INET6,
 446 * services registered via this function will be advertised on
 447 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 448 * addresses).
 449 */
 450int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 451{
 452	struct rpcbind_args map = {
 453		.r_prog		= prog,
 454		.r_vers		= vers,
 455		.r_prot		= prot,
 456		.r_port		= port,
 457	};
 458	struct rpc_message msg = {
 459		.rpc_argp	= &map,
 460	};
 461	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 462	bool is_set = false;
 463
 464	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 465			"rpcbind\n", (port ? "" : "un"),
 466			prog, vers, prot, port);
 467
 468	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 469	if (port != 0) {
 470		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 471		is_set = true;
 472	}
 473
 474	return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
 475}
 476
 477/*
 478 * Fill in AF_INET family-specific arguments to register
 479 */
 480static int rpcb_register_inet4(struct sunrpc_net *sn,
 481			       const struct sockaddr *sap,
 482			       struct rpc_message *msg)
 483{
 484	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 485	struct rpcbind_args *map = msg->rpc_argp;
 486	unsigned short port = ntohs(sin->sin_port);
 487	bool is_set = false;
 488	int result;
 489
 490	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 491
 492	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 493		"local rpcbind\n", (port ? "" : "un"),
 494			map->r_prog, map->r_vers,
 495			map->r_addr, map->r_netid);
 496
 497	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 498	if (port != 0) {
 499		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 500		is_set = true;
 501	}
 502
 503	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 504	kfree(map->r_addr);
 505	return result;
 506}
 507
 508/*
 509 * Fill in AF_INET6 family-specific arguments to register
 510 */
 511static int rpcb_register_inet6(struct sunrpc_net *sn,
 512			       const struct sockaddr *sap,
 513			       struct rpc_message *msg)
 514{
 515	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 516	struct rpcbind_args *map = msg->rpc_argp;
 517	unsigned short port = ntohs(sin6->sin6_port);
 518	bool is_set = false;
 519	int result;
 520
 521	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 522
 523	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 524		"local rpcbind\n", (port ? "" : "un"),
 525			map->r_prog, map->r_vers,
 526			map->r_addr, map->r_netid);
 527
 528	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 529	if (port != 0) {
 530		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 531		is_set = true;
 532	}
 533
 534	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 535	kfree(map->r_addr);
 536	return result;
 537}
 538
 539static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 540					     struct rpc_message *msg)
 541{
 542	struct rpcbind_args *map = msg->rpc_argp;
 543
 544	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 545		"local rpcbind\n",
 546			map->r_prog, map->r_vers, map->r_netid);
 547
 548	map->r_addr = "";
 549	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 550
 551	return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
 552}
 553
 554/**
 555 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 556 * @net: target network namespace
 557 * @program: RPC program number of service to (un)register
 558 * @version: RPC version number of service to (un)register
 559 * @address: address family, IP address, and port to (un)register
 560 * @netid: netid of transport protocol to (un)register
 561 *
 562 * Returns zero if the registration request was dispatched successfully
 563 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 564 * value that reflects the nature of the error (request could not be
 565 * dispatched, timed out, or rpcbind returned an error).
 566 *
 567 * RPC services invoke this function to advertise their contact
 568 * information via the system's rpcbind daemon.  RPC services
 569 * invoke this function once for each [program, version, address,
 570 * netid] tuple they wish to advertise.
 571 *
 572 * Callers may also unregister RPC services that are registered at a
 573 * specific address by setting the port number in @address to zero.
 574 * They may unregister all registered protocol families at once for
 575 * a service by passing a NULL @address argument.  If @netid is ""
 576 * then all netids for [program, version, address] are unregistered.
 577 *
 578 * This function uses rpcbind protocol version 4 to contact the
 579 * local rpcbind daemon.  The local rpcbind daemon must support
 580 * version 4 of the rpcbind protocol in order for these functions
 581 * to register a service successfully.
 582 *
 583 * Supported netids include "udp" and "tcp" for UDP and TCP over
 584 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 585 * respectively.
 586 *
 587 * The contents of @address determine the address family and the
 588 * port to be registered.  The usual practice is to pass INADDR_ANY
 589 * as the raw address, but specifying a non-zero address is also
 590 * supported by this API if the caller wishes to advertise an RPC
 591 * service on a specific network interface.
 592 *
 593 * Note that passing in INADDR_ANY does not create the same service
 594 * registration as IN6ADDR_ANY.  The former advertises an RPC
 595 * service on any IPv4 address, but not on IPv6.  The latter
 596 * advertises the service on all IPv4 and IPv6 addresses.
 597 */
 598int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 599		     const struct sockaddr *address, const char *netid)
 600{
 601	struct rpcbind_args map = {
 602		.r_prog		= program,
 603		.r_vers		= version,
 604		.r_netid	= netid,
 605		.r_owner	= RPCB_OWNER_STRING,
 606	};
 607	struct rpc_message msg = {
 608		.rpc_argp	= &map,
 609	};
 610	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 611
 612	if (sn->rpcb_local_clnt4 == NULL)
 613		return -EPROTONOSUPPORT;
 614
 615	if (address == NULL)
 616		return rpcb_unregister_all_protofamilies(sn, &msg);
 617
 618	switch (address->sa_family) {
 619	case AF_INET:
 620		return rpcb_register_inet4(sn, address, &msg);
 621	case AF_INET6:
 622		return rpcb_register_inet6(sn, address, &msg);
 623	}
 624
 625	return -EAFNOSUPPORT;
 626}
 627
 628static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt,
 629		struct rpcbind_args *map, const struct rpc_procinfo *proc)
 630{
 631	struct rpc_message msg = {
 632		.rpc_proc = proc,
 633		.rpc_argp = map,
 634		.rpc_resp = map,
 635	};
 636	struct rpc_task_setup task_setup_data = {
 637		.rpc_client = rpcb_clnt,
 638		.rpc_message = &msg,
 639		.callback_ops = &rpcb_getport_ops,
 640		.callback_data = map,
 641		.flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 642	};
 643
 644	return rpc_run_task(&task_setup_data);
 645}
 646
 647/*
 648 * In the case where rpc clients have been cloned, we want to make
 649 * sure that we use the program number/version etc of the actual
 650 * owner of the xprt. To do so, we walk back up the tree of parents
 651 * to find whoever created the transport and/or whoever has the
 652 * autobind flag set.
 653 */
 654static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 655{
 656	struct rpc_clnt *parent = clnt->cl_parent;
 657	struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
 658
 659	while (parent != clnt) {
 660		if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
 661			break;
 662		if (clnt->cl_autobind)
 663			break;
 664		clnt = parent;
 665		parent = parent->cl_parent;
 666	}
 667	return clnt;
 668}
 669
 670/**
 671 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 672 * @task: task that is waiting for portmapper request
 673 *
 674 * This one can be called for an ongoing RPC request, and can be used in
 675 * an async (rpciod) context.
 676 */
 677void rpcb_getport_async(struct rpc_task *task)
 678{
 679	struct rpc_clnt *clnt;
 680	const struct rpc_procinfo *proc;
 681	u32 bind_version;
 682	struct rpc_xprt *xprt;
 683	struct rpc_clnt	*rpcb_clnt;
 684	struct rpcbind_args *map;
 685	struct rpc_task	*child;
 686	struct sockaddr_storage addr;
 687	struct sockaddr *sap = (struct sockaddr *)&addr;
 688	size_t salen;
 689	int status;
 690
 691	rcu_read_lock();
 692	clnt = rpcb_find_transport_owner(task->tk_client);
 693	rcu_read_unlock();
 694	xprt = xprt_get(task->tk_xprt);
 695
 696	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 697		task->tk_pid, __func__,
 698		xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 699
 700	/* Put self on the wait queue to ensure we get notified if
 701	 * some other task is already attempting to bind the port */
 702	rpc_sleep_on_timeout(&xprt->binding, task,
 703			NULL, jiffies + xprt->bind_timeout);
 704
 705	if (xprt_test_and_set_binding(xprt)) {
 706		dprintk("RPC: %5u %s: waiting for another binder\n",
 707			task->tk_pid, __func__);
 708		xprt_put(xprt);
 709		return;
 710	}
 711
 712	/* Someone else may have bound if we slept */
 713	if (xprt_bound(xprt)) {
 714		status = 0;
 715		dprintk("RPC: %5u %s: already bound\n",
 716			task->tk_pid, __func__);
 717		goto bailout_nofree;
 718	}
 719
 720	/* Parent transport's destination address */
 721	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 722
 723	/* Don't ever use rpcbind v2 for AF_INET6 requests */
 724	switch (sap->sa_family) {
 725	case AF_INET:
 726		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 727		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 728		break;
 729	case AF_INET6:
 730		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 731		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 732		break;
 733	default:
 734		status = -EAFNOSUPPORT;
 735		dprintk("RPC: %5u %s: bad address family\n",
 736				task->tk_pid, __func__);
 737		goto bailout_nofree;
 738	}
 739	if (proc == NULL) {
 740		xprt->bind_index = 0;
 741		status = -EPFNOSUPPORT;
 742		dprintk("RPC: %5u %s: no more getport versions available\n",
 743			task->tk_pid, __func__);
 744		goto bailout_nofree;
 745	}
 746
 747	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 748		task->tk_pid, __func__, bind_version);
 749
 750	rpcb_clnt = rpcb_create(xprt->xprt_net,
 751				clnt->cl_nodename,
 752				xprt->servername, sap, salen,
 753				xprt->prot, bind_version,
 754				clnt->cl_cred);
 755	if (IS_ERR(rpcb_clnt)) {
 756		status = PTR_ERR(rpcb_clnt);
 757		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 758			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 759		goto bailout_nofree;
 760	}
 761
 762	map = kzalloc(sizeof(struct rpcbind_args), GFP_NOFS);
 763	if (!map) {
 764		status = -ENOMEM;
 765		dprintk("RPC: %5u %s: no memory available\n",
 766			task->tk_pid, __func__);
 767		goto bailout_release_client;
 768	}
 769	map->r_prog = clnt->cl_prog;
 770	map->r_vers = clnt->cl_vers;
 771	map->r_prot = xprt->prot;
 772	map->r_port = 0;
 773	map->r_xprt = xprt;
 774	map->r_status = -EIO;
 775
 776	switch (bind_version) {
 777	case RPCBVERS_4:
 778	case RPCBVERS_3:
 779		map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 780		map->r_addr = rpc_sockaddr2uaddr(sap, GFP_NOFS);
 781		if (!map->r_addr) {
 782			status = -ENOMEM;
 783			dprintk("RPC: %5u %s: no memory available\n",
 784				task->tk_pid, __func__);
 785			goto bailout_free_args;
 786		}
 787		map->r_owner = "";
 788		break;
 789	case RPCBVERS_2:
 790		map->r_addr = NULL;
 791		break;
 792	default:
 793		BUG();
 794	}
 795
 796	child = rpcb_call_async(rpcb_clnt, map, proc);
 797	rpc_release_client(rpcb_clnt);
 798
 799	xprt->stat.bind_count++;
 800	rpc_put_task(child);
 801	return;
 802
 803bailout_free_args:
 804	kfree(map);
 805bailout_release_client:
 806	rpc_release_client(rpcb_clnt);
 807bailout_nofree:
 808	rpcb_wake_rpcbind_waiters(xprt, status);
 809	task->tk_status = status;
 810	xprt_put(xprt);
 811}
 812EXPORT_SYMBOL_GPL(rpcb_getport_async);
 813
 814/*
 815 * Rpcbind child task calls this callback via tk_exit.
 816 */
 817static void rpcb_getport_done(struct rpc_task *child, void *data)
 818{
 819	struct rpcbind_args *map = data;
 820	struct rpc_xprt *xprt = map->r_xprt;
 821	int status = child->tk_status;
 822
 823	/* Garbage reply: retry with a lesser rpcbind version */
 824	if (status == -EIO)
 825		status = -EPROTONOSUPPORT;
 826
 827	/* rpcbind server doesn't support this rpcbind protocol version */
 828	if (status == -EPROTONOSUPPORT)
 829		xprt->bind_index++;
 830
 831	if (status < 0) {
 832		/* rpcbind server not available on remote host? */
 833		xprt->ops->set_port(xprt, 0);
 834	} else if (map->r_port == 0) {
 835		/* Requested RPC service wasn't registered on remote host */
 836		xprt->ops->set_port(xprt, 0);
 837		status = -EACCES;
 838	} else {
 839		/* Succeeded */
 840		xprt->ops->set_port(xprt, map->r_port);
 841		xprt_set_bound(xprt);
 842		status = 0;
 843	}
 844
 845	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 846			child->tk_pid, status, map->r_port);
 847
 848	map->r_status = status;
 849}
 850
 851/*
 852 * XDR functions for rpcbind
 853 */
 854
 855static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 856			     const void *data)
 857{
 858	const struct rpcbind_args *rpcb = data;
 859	__be32 *p;
 860
 861	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 862			req->rq_task->tk_pid,
 863			req->rq_task->tk_msg.rpc_proc->p_name,
 864			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 865
 866	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 867	*p++ = cpu_to_be32(rpcb->r_prog);
 868	*p++ = cpu_to_be32(rpcb->r_vers);
 869	*p++ = cpu_to_be32(rpcb->r_prot);
 870	*p   = cpu_to_be32(rpcb->r_port);
 871}
 872
 873static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 874			    void *data)
 875{
 876	struct rpcbind_args *rpcb = data;
 877	unsigned long port;
 878	__be32 *p;
 879
 880	rpcb->r_port = 0;
 881
 882	p = xdr_inline_decode(xdr, 4);
 883	if (unlikely(p == NULL))
 884		return -EIO;
 885
 886	port = be32_to_cpup(p);
 887	dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 888			req->rq_task->tk_msg.rpc_proc->p_name, port);
 889	if (unlikely(port > USHRT_MAX))
 890		return -EIO;
 891
 892	rpcb->r_port = port;
 893	return 0;
 894}
 895
 896static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 897			void *data)
 898{
 899	unsigned int *boolp = data;
 900	__be32 *p;
 901
 902	p = xdr_inline_decode(xdr, 4);
 903	if (unlikely(p == NULL))
 904		return -EIO;
 905
 906	*boolp = 0;
 907	if (*p != xdr_zero)
 908		*boolp = 1;
 909
 910	dprintk("RPC: %5u RPCB_%s call %s\n",
 911			req->rq_task->tk_pid,
 912			req->rq_task->tk_msg.rpc_proc->p_name,
 913			(*boolp ? "succeeded" : "failed"));
 914	return 0;
 915}
 916
 917static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 918			       const u32 maxstrlen)
 919{
 920	__be32 *p;
 921	u32 len;
 922
 923	len = strlen(string);
 924	WARN_ON_ONCE(len > maxstrlen);
 925	if (len > maxstrlen)
 926		/* truncate and hope for the best */
 927		len = maxstrlen;
 928	p = xdr_reserve_space(xdr, 4 + len);
 929	xdr_encode_opaque(p, string, len);
 930}
 931
 932static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 933			     const void *data)
 934{
 935	const struct rpcbind_args *rpcb = data;
 936	__be32 *p;
 937
 938	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 939			req->rq_task->tk_pid,
 940			req->rq_task->tk_msg.rpc_proc->p_name,
 941			rpcb->r_prog, rpcb->r_vers,
 942			rpcb->r_netid, rpcb->r_addr);
 943
 944	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 945	*p++ = cpu_to_be32(rpcb->r_prog);
 946	*p = cpu_to_be32(rpcb->r_vers);
 947
 948	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 949	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 950	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 951}
 952
 953static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 954			    void *data)
 955{
 956	struct rpcbind_args *rpcb = data;
 957	struct sockaddr_storage address;
 958	struct sockaddr *sap = (struct sockaddr *)&address;
 959	__be32 *p;
 960	u32 len;
 961
 962	rpcb->r_port = 0;
 963
 964	p = xdr_inline_decode(xdr, 4);
 965	if (unlikely(p == NULL))
 966		goto out_fail;
 967	len = be32_to_cpup(p);
 968
 969	/*
 970	 * If the returned universal address is a null string,
 971	 * the requested RPC service was not registered.
 972	 */
 973	if (len == 0) {
 974		dprintk("RPC: %5u RPCB reply: program not registered\n",
 975				req->rq_task->tk_pid);
 976		return 0;
 977	}
 978
 979	if (unlikely(len > RPCBIND_MAXUADDRLEN))
 980		goto out_fail;
 981
 982	p = xdr_inline_decode(xdr, len);
 983	if (unlikely(p == NULL))
 984		goto out_fail;
 985	dprintk("RPC: %5u RPCB_%s reply: %*pE\n", req->rq_task->tk_pid,
 986			req->rq_task->tk_msg.rpc_proc->p_name, len, (char *)p);
 987
 988	if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 989				sap, sizeof(address)) == 0)
 990		goto out_fail;
 991	rpcb->r_port = rpc_get_port(sap);
 992
 993	return 0;
 994
 995out_fail:
 996	dprintk("RPC: %5u malformed RPCB_%s reply\n",
 997			req->rq_task->tk_pid,
 998			req->rq_task->tk_msg.rpc_proc->p_name);
 999	return -EIO;
1000}
1001
1002/*
1003 * Not all rpcbind procedures described in RFC 1833 are implemented
1004 * since the Linux kernel RPC code requires only these.
1005 */
1006
1007static const struct rpc_procinfo rpcb_procedures2[] = {
1008	[RPCBPROC_SET] = {
1009		.p_proc		= RPCBPROC_SET,
1010		.p_encode	= rpcb_enc_mapping,
1011		.p_decode	= rpcb_dec_set,
1012		.p_arglen	= RPCB_mappingargs_sz,
1013		.p_replen	= RPCB_setres_sz,
1014		.p_statidx	= RPCBPROC_SET,
1015		.p_timer	= 0,
1016		.p_name		= "SET",
1017	},
1018	[RPCBPROC_UNSET] = {
1019		.p_proc		= RPCBPROC_UNSET,
1020		.p_encode	= rpcb_enc_mapping,
1021		.p_decode	= rpcb_dec_set,
1022		.p_arglen	= RPCB_mappingargs_sz,
1023		.p_replen	= RPCB_setres_sz,
1024		.p_statidx	= RPCBPROC_UNSET,
1025		.p_timer	= 0,
1026		.p_name		= "UNSET",
1027	},
1028	[RPCBPROC_GETPORT] = {
1029		.p_proc		= RPCBPROC_GETPORT,
1030		.p_encode	= rpcb_enc_mapping,
1031		.p_decode	= rpcb_dec_getport,
1032		.p_arglen	= RPCB_mappingargs_sz,
1033		.p_replen	= RPCB_getportres_sz,
1034		.p_statidx	= RPCBPROC_GETPORT,
1035		.p_timer	= 0,
1036		.p_name		= "GETPORT",
1037	},
1038};
1039
1040static const struct rpc_procinfo rpcb_procedures3[] = {
1041	[RPCBPROC_SET] = {
1042		.p_proc		= RPCBPROC_SET,
1043		.p_encode	= rpcb_enc_getaddr,
1044		.p_decode	= rpcb_dec_set,
1045		.p_arglen	= RPCB_getaddrargs_sz,
1046		.p_replen	= RPCB_setres_sz,
1047		.p_statidx	= RPCBPROC_SET,
1048		.p_timer	= 0,
1049		.p_name		= "SET",
1050	},
1051	[RPCBPROC_UNSET] = {
1052		.p_proc		= RPCBPROC_UNSET,
1053		.p_encode	= rpcb_enc_getaddr,
1054		.p_decode	= rpcb_dec_set,
1055		.p_arglen	= RPCB_getaddrargs_sz,
1056		.p_replen	= RPCB_setres_sz,
1057		.p_statidx	= RPCBPROC_UNSET,
1058		.p_timer	= 0,
1059		.p_name		= "UNSET",
1060	},
1061	[RPCBPROC_GETADDR] = {
1062		.p_proc		= RPCBPROC_GETADDR,
1063		.p_encode	= rpcb_enc_getaddr,
1064		.p_decode	= rpcb_dec_getaddr,
1065		.p_arglen	= RPCB_getaddrargs_sz,
1066		.p_replen	= RPCB_getaddrres_sz,
1067		.p_statidx	= RPCBPROC_GETADDR,
1068		.p_timer	= 0,
1069		.p_name		= "GETADDR",
1070	},
1071};
1072
1073static const struct rpc_procinfo rpcb_procedures4[] = {
1074	[RPCBPROC_SET] = {
1075		.p_proc		= RPCBPROC_SET,
1076		.p_encode	= rpcb_enc_getaddr,
1077		.p_decode	= rpcb_dec_set,
1078		.p_arglen	= RPCB_getaddrargs_sz,
1079		.p_replen	= RPCB_setres_sz,
1080		.p_statidx	= RPCBPROC_SET,
1081		.p_timer	= 0,
1082		.p_name		= "SET",
1083	},
1084	[RPCBPROC_UNSET] = {
1085		.p_proc		= RPCBPROC_UNSET,
1086		.p_encode	= rpcb_enc_getaddr,
1087		.p_decode	= rpcb_dec_set,
1088		.p_arglen	= RPCB_getaddrargs_sz,
1089		.p_replen	= RPCB_setres_sz,
1090		.p_statidx	= RPCBPROC_UNSET,
1091		.p_timer	= 0,
1092		.p_name		= "UNSET",
1093	},
1094	[RPCBPROC_GETADDR] = {
1095		.p_proc		= RPCBPROC_GETADDR,
1096		.p_encode	= rpcb_enc_getaddr,
1097		.p_decode	= rpcb_dec_getaddr,
1098		.p_arglen	= RPCB_getaddrargs_sz,
1099		.p_replen	= RPCB_getaddrres_sz,
1100		.p_statidx	= RPCBPROC_GETADDR,
1101		.p_timer	= 0,
1102		.p_name		= "GETADDR",
1103	},
1104};
1105
1106static const struct rpcb_info rpcb_next_version[] = {
1107	{
1108		.rpc_vers	= RPCBVERS_2,
1109		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
1110	},
1111	{
1112		.rpc_proc	= NULL,
1113	},
1114};
1115
1116static const struct rpcb_info rpcb_next_version6[] = {
1117	{
1118		.rpc_vers	= RPCBVERS_4,
1119		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
1120	},
1121	{
1122		.rpc_vers	= RPCBVERS_3,
1123		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
1124	},
1125	{
1126		.rpc_proc	= NULL,
1127	},
1128};
1129
1130static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)];
1131static const struct rpc_version rpcb_version2 = {
1132	.number		= RPCBVERS_2,
1133	.nrprocs	= ARRAY_SIZE(rpcb_procedures2),
1134	.procs		= rpcb_procedures2,
1135	.counts		= rpcb_version2_counts,
1136};
1137
1138static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)];
1139static const struct rpc_version rpcb_version3 = {
1140	.number		= RPCBVERS_3,
1141	.nrprocs	= ARRAY_SIZE(rpcb_procedures3),
1142	.procs		= rpcb_procedures3,
1143	.counts		= rpcb_version3_counts,
1144};
1145
1146static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)];
1147static const struct rpc_version rpcb_version4 = {
1148	.number		= RPCBVERS_4,
1149	.nrprocs	= ARRAY_SIZE(rpcb_procedures4),
1150	.procs		= rpcb_procedures4,
1151	.counts		= rpcb_version4_counts,
1152};
1153
1154static const struct rpc_version *rpcb_version[] = {
1155	NULL,
1156	NULL,
1157	&rpcb_version2,
1158	&rpcb_version3,
1159	&rpcb_version4
1160};
1161
1162static struct rpc_stat rpcb_stats;
1163
1164static const struct rpc_program rpcb_program = {
1165	.name		= "rpcbind",
1166	.number		= RPCBIND_PROGRAM,
1167	.nrvers		= ARRAY_SIZE(rpcb_version),
1168	.version	= rpcb_version,
1169	.stats		= &rpcb_stats,
1170};