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v3.5.6
   1/*
   2 * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3 * protocol
   4 *
   5 * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6 * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7 *
   8 * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9 * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10 *
  11 * Descended from net/sunrpc/pmap_clnt.c,
  12 *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13 */
  14
  15#include <linux/module.h>
  16
  17#include <linux/types.h>
  18#include <linux/socket.h>
  19#include <linux/un.h>
  20#include <linux/in.h>
  21#include <linux/in6.h>
  22#include <linux/kernel.h>
  23#include <linux/errno.h>
  24#include <linux/mutex.h>
  25#include <linux/slab.h>
  26#include <linux/nsproxy.h>
  27#include <net/ipv6.h>
  28
  29#include <linux/sunrpc/clnt.h>
 
  30#include <linux/sunrpc/sched.h>
  31#include <linux/sunrpc/xprtsock.h>
  32
  33#include "netns.h"
  34
  35#ifdef RPC_DEBUG
  36# define RPCDBG_FACILITY	RPCDBG_BIND
  37#endif
  38
  39#define RPCBIND_SOCK_PATHNAME	"/var/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
  48enum {
  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
 113static void			rpcb_getport_done(struct rpc_task *, void *);
 114static void			rpcb_map_release(void *data);
 115static const struct rpc_program	rpcb_program;
 116
 117struct 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
 131static struct rpc_procinfo rpcb_procedures2[];
 132static struct rpc_procinfo rpcb_procedures3[];
 133static struct rpc_procinfo rpcb_procedures4[];
 134
 135struct rpcb_info {
 136	u32			rpc_vers;
 137	struct rpc_procinfo *	rpc_proc;
 138};
 139
 140static const struct rpcb_info rpcb_next_version[];
 141static const struct rpcb_info rpcb_next_version6[];
 142
 143static const struct rpc_call_ops rpcb_getport_ops = {
 144	.rpc_call_done		= rpcb_getport_done,
 145	.rpc_release		= rpcb_map_release,
 146};
 147
 148static 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
 154static 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
 164static 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
 178void 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
 206static void rpcb_set_local(struct net *net, struct rpc_clnt *clnt,
 207			struct rpc_clnt *clnt4)
 
 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	smp_wmb(); 
 215	sn->rpcb_users = 1;
 216	dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 217			"%p, rpcb_local_clnt4: %p) for net %p%s\n",
 218			sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 219			net, (net == &init_net) ? " (init_net)" : "");
 220}
 221
 222/*
 223 * Returns zero on success, otherwise a negative errno value
 224 * is returned.
 225 */
 226static int rpcb_create_local_unix(struct net *net)
 227{
 228	static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 229		.sun_family		= AF_LOCAL,
 230		.sun_path		= RPCBIND_SOCK_PATHNAME,
 231	};
 232	struct rpc_create_args args = {
 233		.net		= net,
 234		.protocol	= XPRT_TRANSPORT_LOCAL,
 235		.address	= (struct sockaddr *)&rpcb_localaddr_rpcbind,
 236		.addrsize	= sizeof(rpcb_localaddr_rpcbind),
 237		.servername	= "localhost",
 238		.program	= &rpcb_program,
 239		.version	= RPCBVERS_2,
 240		.authflavor	= RPC_AUTH_NULL,
 
 
 
 
 
 
 
 
 241	};
 242	struct rpc_clnt *clnt, *clnt4;
 243	int result = 0;
 244
 245	/*
 246	 * Because we requested an RPC PING at transport creation time,
 247	 * this works only if the user space portmapper is rpcbind, and
 248	 * it's listening on AF_LOCAL on the named socket.
 249	 */
 250	clnt = rpc_create(&args);
 251	if (IS_ERR(clnt)) {
 252		dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 253				"client (errno %ld).\n", PTR_ERR(clnt));
 254		result = PTR_ERR(clnt);
 255		goto out;
 256	}
 257
 258	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 259	if (IS_ERR(clnt4)) {
 260		dprintk("RPC:       failed to bind second program to "
 261				"rpcbind v4 client (errno %ld).\n",
 262				PTR_ERR(clnt4));
 263		clnt4 = NULL;
 264	}
 265
 266	rpcb_set_local(net, clnt, clnt4);
 267
 268out:
 269	return result;
 270}
 271
 272/*
 273 * Returns zero on success, otherwise a negative errno value
 274 * is returned.
 275 */
 276static 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		.flags		= RPC_CLNT_CREATE_NOPING,
 293	};
 294	struct rpc_clnt *clnt, *clnt4;
 295	int result = 0;
 296
 297	clnt = rpc_create(&args);
 298	if (IS_ERR(clnt)) {
 299		dprintk("RPC:       failed to create local rpcbind "
 300				"client (errno %ld).\n", PTR_ERR(clnt));
 301		result = PTR_ERR(clnt);
 302		goto out;
 303	}
 304
 305	/*
 306	 * This results in an RPC ping.  On systems running portmapper,
 307	 * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 308	 * v4 upcalls.
 309	 */
 310	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 311	if (IS_ERR(clnt4)) {
 312		dprintk("RPC:       failed to bind second program to "
 313				"rpcbind v4 client (errno %ld).\n",
 314				PTR_ERR(clnt4));
 315		clnt4 = NULL;
 316	}
 317
 318	rpcb_set_local(net, clnt, clnt4);
 319
 320out:
 321	return result;
 322}
 323
 324/*
 325 * Returns zero on success, otherwise a negative errno value
 326 * is returned.
 327 */
 328int rpcb_create_local(struct net *net)
 329{
 330	static DEFINE_MUTEX(rpcb_create_local_mutex);
 331	int result = 0;
 332
 333	if (rpcb_get_local(net))
 334		return result;
 335
 336	mutex_lock(&rpcb_create_local_mutex);
 337	if (rpcb_get_local(net))
 338		goto out;
 339
 340	if (rpcb_create_local_unix(net) != 0)
 341		result = rpcb_create_local_net(net);
 342
 343out:
 344	mutex_unlock(&rpcb_create_local_mutex);
 345	return result;
 346}
 347
 348static struct rpc_clnt *rpcb_create(struct net *net, const char *hostname,
 
 349				    struct sockaddr *srvaddr, size_t salen,
 350				    int proto, u32 version)
 351{
 352	struct rpc_create_args args = {
 353		.net		= net,
 354		.protocol	= proto,
 355		.address	= srvaddr,
 356		.addrsize	= salen,
 357		.servername	= hostname,
 
 358		.program	= &rpcb_program,
 359		.version	= version,
 360		.authflavor	= RPC_AUTH_UNIX,
 361		.flags		= (RPC_CLNT_CREATE_NOPING |
 362					RPC_CLNT_CREATE_NONPRIVPORT),
 363	};
 364
 365	switch (srvaddr->sa_family) {
 366	case AF_INET:
 367		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 368		break;
 369	case AF_INET6:
 370		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 371		break;
 372	default:
 373		return ERR_PTR(-EAFNOSUPPORT);
 374	}
 375
 376	return rpc_create(&args);
 377}
 378
 379static int rpcb_register_call(struct rpc_clnt *clnt, struct rpc_message *msg)
 380{
 381	int result, error = 0;
 
 382
 
 
 383	msg->rpc_resp = &result;
 384
 385	error = rpc_call_sync(clnt, msg, RPC_TASK_SOFTCONN);
 386	if (error < 0) {
 387		dprintk("RPC:       failed to contact local rpcbind "
 388				"server (errno %d).\n", -error);
 389		return error;
 390	}
 391
 392	if (!result)
 393		return -EACCES;
 394	return 0;
 395}
 396
 397/**
 398 * rpcb_register - set or unset a port registration with the local rpcbind svc
 399 * @net: target network namespace
 400 * @prog: RPC program number to bind
 401 * @vers: RPC version number to bind
 402 * @prot: transport protocol to register
 403 * @port: port value to register
 404 *
 405 * Returns zero if the registration request was dispatched successfully
 406 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 407 * value that reflects the nature of the error (request could not be
 408 * dispatched, timed out, or rpcbind returned an error).
 409 *
 410 * RPC services invoke this function to advertise their contact
 411 * information via the system's rpcbind daemon.  RPC services
 412 * invoke this function once for each [program, version, transport]
 413 * tuple they wish to advertise.
 414 *
 415 * Callers may also unregister RPC services that are no longer
 416 * available by setting the passed-in port to zero.  This removes
 417 * all registered transports for [program, version] from the local
 418 * rpcbind database.
 419 *
 420 * This function uses rpcbind protocol version 2 to contact the
 421 * local rpcbind daemon.
 422 *
 423 * Registration works over both AF_INET and AF_INET6, and services
 424 * registered via this function are advertised as available for any
 425 * address.  If the local rpcbind daemon is listening on AF_INET6,
 426 * services registered via this function will be advertised on
 427 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 428 * addresses).
 429 */
 430int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 431{
 432	struct rpcbind_args map = {
 433		.r_prog		= prog,
 434		.r_vers		= vers,
 435		.r_prot		= prot,
 436		.r_port		= port,
 437	};
 438	struct rpc_message msg = {
 439		.rpc_argp	= &map,
 440	};
 441	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 
 442
 443	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 444			"rpcbind\n", (port ? "" : "un"),
 445			prog, vers, prot, port);
 446
 447	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 448	if (port)
 449		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 
 
 450
 451	return rpcb_register_call(sn->rpcb_local_clnt, &msg);
 452}
 453
 454/*
 455 * Fill in AF_INET family-specific arguments to register
 456 */
 457static 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	int result;
 465
 466	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 467
 468	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 469		"local rpcbind\n", (port ? "" : "un"),
 470			map->r_prog, map->r_vers,
 471			map->r_addr, map->r_netid);
 472
 473	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 474	if (port)
 475		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
 
 476
 477	result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 478	kfree(map->r_addr);
 479	return result;
 480}
 481
 482/*
 483 * Fill in AF_INET6 family-specific arguments to register
 484 */
 485static int rpcb_register_inet6(struct sunrpc_net *sn,
 486			       const struct sockaddr *sap,
 487			       struct rpc_message *msg)
 488{
 489	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 490	struct rpcbind_args *map = msg->rpc_argp;
 491	unsigned short port = ntohs(sin6->sin6_port);
 
 492	int result;
 493
 494	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 495
 496	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 497		"local rpcbind\n", (port ? "" : "un"),
 498			map->r_prog, map->r_vers,
 499			map->r_addr, map->r_netid);
 500
 501	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 502	if (port)
 503		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 
 
 504
 505	result = rpcb_register_call(sn->rpcb_local_clnt4, msg);
 506	kfree(map->r_addr);
 507	return result;
 508}
 509
 510static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 511					     struct rpc_message *msg)
 512{
 513	struct rpcbind_args *map = msg->rpc_argp;
 514
 515	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 516		"local rpcbind\n",
 517			map->r_prog, map->r_vers, map->r_netid);
 518
 519	map->r_addr = "";
 520	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 521
 522	return rpcb_register_call(sn->rpcb_local_clnt4, msg);
 523}
 524
 525/**
 526 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 527 * @net: target network namespace
 528 * @program: RPC program number of service to (un)register
 529 * @version: RPC version number of service to (un)register
 530 * @address: address family, IP address, and port to (un)register
 531 * @netid: netid of transport protocol to (un)register
 532 *
 533 * Returns zero if the registration request was dispatched successfully
 534 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 535 * value that reflects the nature of the error (request could not be
 536 * dispatched, timed out, or rpcbind returned an error).
 537 *
 538 * RPC services invoke this function to advertise their contact
 539 * information via the system's rpcbind daemon.  RPC services
 540 * invoke this function once for each [program, version, address,
 541 * netid] tuple they wish to advertise.
 542 *
 543 * Callers may also unregister RPC services that are registered at a
 544 * specific address by setting the port number in @address to zero.
 545 * They may unregister all registered protocol families at once for
 546 * a service by passing a NULL @address argument.  If @netid is ""
 547 * then all netids for [program, version, address] are unregistered.
 548 *
 549 * This function uses rpcbind protocol version 4 to contact the
 550 * local rpcbind daemon.  The local rpcbind daemon must support
 551 * version 4 of the rpcbind protocol in order for these functions
 552 * to register a service successfully.
 553 *
 554 * Supported netids include "udp" and "tcp" for UDP and TCP over
 555 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 556 * respectively.
 557 *
 558 * The contents of @address determine the address family and the
 559 * port to be registered.  The usual practice is to pass INADDR_ANY
 560 * as the raw address, but specifying a non-zero address is also
 561 * supported by this API if the caller wishes to advertise an RPC
 562 * service on a specific network interface.
 563 *
 564 * Note that passing in INADDR_ANY does not create the same service
 565 * registration as IN6ADDR_ANY.  The former advertises an RPC
 566 * service on any IPv4 address, but not on IPv6.  The latter
 567 * advertises the service on all IPv4 and IPv6 addresses.
 568 */
 569int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 570		     const struct sockaddr *address, const char *netid)
 571{
 572	struct rpcbind_args map = {
 573		.r_prog		= program,
 574		.r_vers		= version,
 575		.r_netid	= netid,
 576		.r_owner	= RPCB_OWNER_STRING,
 577	};
 578	struct rpc_message msg = {
 579		.rpc_argp	= &map,
 580	};
 581	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 582
 583	if (sn->rpcb_local_clnt4 == NULL)
 584		return -EPROTONOSUPPORT;
 585
 586	if (address == NULL)
 587		return rpcb_unregister_all_protofamilies(sn, &msg);
 588
 589	switch (address->sa_family) {
 590	case AF_INET:
 591		return rpcb_register_inet4(sn, address, &msg);
 592	case AF_INET6:
 593		return rpcb_register_inet6(sn, address, &msg);
 594	}
 595
 596	return -EAFNOSUPPORT;
 597}
 598
 599static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 600{
 601	struct rpc_message msg = {
 602		.rpc_proc = proc,
 603		.rpc_argp = map,
 604		.rpc_resp = map,
 605	};
 606	struct rpc_task_setup task_setup_data = {
 607		.rpc_client = rpcb_clnt,
 608		.rpc_message = &msg,
 609		.callback_ops = &rpcb_getport_ops,
 610		.callback_data = map,
 611		.flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 612	};
 613
 614	return rpc_run_task(&task_setup_data);
 615}
 616
 617/*
 618 * In the case where rpc clients have been cloned, we want to make
 619 * sure that we use the program number/version etc of the actual
 620 * owner of the xprt. To do so, we walk back up the tree of parents
 621 * to find whoever created the transport and/or whoever has the
 622 * autobind flag set.
 623 */
 624static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 625{
 626	struct rpc_clnt *parent = clnt->cl_parent;
 627	struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
 628
 629	while (parent != clnt) {
 630		if (rcu_dereference(parent->cl_xprt) != xprt)
 631			break;
 632		if (clnt->cl_autobind)
 633			break;
 634		clnt = parent;
 635		parent = parent->cl_parent;
 636	}
 637	return clnt;
 638}
 639
 640/**
 641 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 642 * @task: task that is waiting for portmapper request
 643 *
 644 * This one can be called for an ongoing RPC request, and can be used in
 645 * an async (rpciod) context.
 646 */
 647void rpcb_getport_async(struct rpc_task *task)
 648{
 649	struct rpc_clnt *clnt;
 650	struct rpc_procinfo *proc;
 651	u32 bind_version;
 652	struct rpc_xprt *xprt;
 653	struct rpc_clnt	*rpcb_clnt;
 654	struct rpcbind_args *map;
 655	struct rpc_task	*child;
 656	struct sockaddr_storage addr;
 657	struct sockaddr *sap = (struct sockaddr *)&addr;
 658	size_t salen;
 659	int status;
 660
 661	rcu_read_lock();
 662	do {
 663		clnt = rpcb_find_transport_owner(task->tk_client);
 664		xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 665	} while (xprt == NULL);
 666	rcu_read_unlock();
 
 667
 668	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 669		task->tk_pid, __func__,
 670		xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 671
 672	/* Put self on the wait queue to ensure we get notified if
 673	 * some other task is already attempting to bind the port */
 674	rpc_sleep_on(&xprt->binding, task, NULL);
 675
 676	if (xprt_test_and_set_binding(xprt)) {
 677		dprintk("RPC: %5u %s: waiting for another binder\n",
 678			task->tk_pid, __func__);
 679		xprt_put(xprt);
 680		return;
 681	}
 682
 683	/* Someone else may have bound if we slept */
 684	if (xprt_bound(xprt)) {
 685		status = 0;
 686		dprintk("RPC: %5u %s: already bound\n",
 687			task->tk_pid, __func__);
 688		goto bailout_nofree;
 689	}
 690
 691	/* Parent transport's destination address */
 692	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 693
 694	/* Don't ever use rpcbind v2 for AF_INET6 requests */
 695	switch (sap->sa_family) {
 696	case AF_INET:
 697		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 698		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 699		break;
 700	case AF_INET6:
 701		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 702		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 703		break;
 704	default:
 705		status = -EAFNOSUPPORT;
 706		dprintk("RPC: %5u %s: bad address family\n",
 707				task->tk_pid, __func__);
 708		goto bailout_nofree;
 709	}
 710	if (proc == NULL) {
 711		xprt->bind_index = 0;
 712		status = -EPFNOSUPPORT;
 713		dprintk("RPC: %5u %s: no more getport versions available\n",
 714			task->tk_pid, __func__);
 715		goto bailout_nofree;
 716	}
 717
 718	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 719		task->tk_pid, __func__, bind_version);
 720
 721	rpcb_clnt = rpcb_create(xprt->xprt_net, xprt->servername, sap, salen,
 
 
 722				xprt->prot, bind_version);
 723	if (IS_ERR(rpcb_clnt)) {
 724		status = PTR_ERR(rpcb_clnt);
 725		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 726			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 727		goto bailout_nofree;
 728	}
 729
 730	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 731	if (!map) {
 732		status = -ENOMEM;
 733		dprintk("RPC: %5u %s: no memory available\n",
 734			task->tk_pid, __func__);
 735		goto bailout_release_client;
 736	}
 737	map->r_prog = clnt->cl_prog;
 738	map->r_vers = clnt->cl_vers;
 739	map->r_prot = xprt->prot;
 740	map->r_port = 0;
 741	map->r_xprt = xprt;
 742	map->r_status = -EIO;
 743
 744	switch (bind_version) {
 745	case RPCBVERS_4:
 746	case RPCBVERS_3:
 747		map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 748		map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 749		map->r_owner = "";
 750		break;
 751	case RPCBVERS_2:
 752		map->r_addr = NULL;
 753		break;
 754	default:
 755		BUG();
 756	}
 757
 758	child = rpcb_call_async(rpcb_clnt, map, proc);
 759	rpc_release_client(rpcb_clnt);
 760	if (IS_ERR(child)) {
 761		/* rpcb_map_release() has freed the arguments */
 762		dprintk("RPC: %5u %s: rpc_run_task failed\n",
 763			task->tk_pid, __func__);
 764		return;
 765	}
 766
 767	xprt->stat.bind_count++;
 768	rpc_put_task(child);
 769	return;
 770
 771bailout_release_client:
 772	rpc_release_client(rpcb_clnt);
 773bailout_nofree:
 774	rpcb_wake_rpcbind_waiters(xprt, status);
 775	task->tk_status = status;
 776	xprt_put(xprt);
 777}
 778EXPORT_SYMBOL_GPL(rpcb_getport_async);
 779
 780/*
 781 * Rpcbind child task calls this callback via tk_exit.
 782 */
 783static void rpcb_getport_done(struct rpc_task *child, void *data)
 784{
 785	struct rpcbind_args *map = data;
 786	struct rpc_xprt *xprt = map->r_xprt;
 787	int status = child->tk_status;
 788
 789	/* Garbage reply: retry with a lesser rpcbind version */
 790	if (status == -EIO)
 791		status = -EPROTONOSUPPORT;
 792
 793	/* rpcbind server doesn't support this rpcbind protocol version */
 794	if (status == -EPROTONOSUPPORT)
 795		xprt->bind_index++;
 796
 797	if (status < 0) {
 798		/* rpcbind server not available on remote host? */
 799		xprt->ops->set_port(xprt, 0);
 800	} else if (map->r_port == 0) {
 801		/* Requested RPC service wasn't registered on remote host */
 802		xprt->ops->set_port(xprt, 0);
 803		status = -EACCES;
 804	} else {
 805		/* Succeeded */
 806		xprt->ops->set_port(xprt, map->r_port);
 807		xprt_set_bound(xprt);
 808		status = 0;
 809	}
 810
 811	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 812			child->tk_pid, status, map->r_port);
 813
 814	map->r_status = status;
 815}
 816
 817/*
 818 * XDR functions for rpcbind
 819 */
 820
 821static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 822			     const struct rpcbind_args *rpcb)
 823{
 824	__be32 *p;
 825
 826	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 827			req->rq_task->tk_pid,
 828			req->rq_task->tk_msg.rpc_proc->p_name,
 829			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 830
 831	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 832	*p++ = cpu_to_be32(rpcb->r_prog);
 833	*p++ = cpu_to_be32(rpcb->r_vers);
 834	*p++ = cpu_to_be32(rpcb->r_prot);
 835	*p   = cpu_to_be32(rpcb->r_port);
 836}
 837
 838static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 839			    struct rpcbind_args *rpcb)
 840{
 841	unsigned long port;
 842	__be32 *p;
 843
 844	rpcb->r_port = 0;
 845
 846	p = xdr_inline_decode(xdr, 4);
 847	if (unlikely(p == NULL))
 848		return -EIO;
 849
 850	port = be32_to_cpup(p);
 851	dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 852			req->rq_task->tk_msg.rpc_proc->p_name, port);
 853	if (unlikely(port > USHRT_MAX))
 854		return -EIO;
 855
 856	rpcb->r_port = port;
 857	return 0;
 858}
 859
 860static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 861			unsigned int *boolp)
 862{
 863	__be32 *p;
 864
 865	p = xdr_inline_decode(xdr, 4);
 866	if (unlikely(p == NULL))
 867		return -EIO;
 868
 869	*boolp = 0;
 870	if (*p != xdr_zero)
 871		*boolp = 1;
 872
 873	dprintk("RPC: %5u RPCB_%s call %s\n",
 874			req->rq_task->tk_pid,
 875			req->rq_task->tk_msg.rpc_proc->p_name,
 876			(*boolp ? "succeeded" : "failed"));
 877	return 0;
 878}
 879
 880static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 881			       const u32 maxstrlen)
 882{
 883	__be32 *p;
 884	u32 len;
 885
 886	len = strlen(string);
 887	BUG_ON(len > maxstrlen);
 
 
 
 888	p = xdr_reserve_space(xdr, 4 + len);
 889	xdr_encode_opaque(p, string, len);
 890}
 891
 892static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 893			     const struct rpcbind_args *rpcb)
 894{
 895	__be32 *p;
 896
 897	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 898			req->rq_task->tk_pid,
 899			req->rq_task->tk_msg.rpc_proc->p_name,
 900			rpcb->r_prog, rpcb->r_vers,
 901			rpcb->r_netid, rpcb->r_addr);
 902
 903	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 904	*p++ = cpu_to_be32(rpcb->r_prog);
 905	*p = cpu_to_be32(rpcb->r_vers);
 906
 907	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 908	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 909	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 910}
 911
 912static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 913			    struct rpcbind_args *rpcb)
 914{
 915	struct sockaddr_storage address;
 916	struct sockaddr *sap = (struct sockaddr *)&address;
 917	__be32 *p;
 918	u32 len;
 919
 920	rpcb->r_port = 0;
 921
 922	p = xdr_inline_decode(xdr, 4);
 923	if (unlikely(p == NULL))
 924		goto out_fail;
 925	len = be32_to_cpup(p);
 926
 927	/*
 928	 * If the returned universal address is a null string,
 929	 * the requested RPC service was not registered.
 930	 */
 931	if (len == 0) {
 932		dprintk("RPC: %5u RPCB reply: program not registered\n",
 933				req->rq_task->tk_pid);
 934		return 0;
 935	}
 936
 937	if (unlikely(len > RPCBIND_MAXUADDRLEN))
 938		goto out_fail;
 939
 940	p = xdr_inline_decode(xdr, len);
 941	if (unlikely(p == NULL))
 942		goto out_fail;
 943	dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 944			req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 945
 946	if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 947				sap, sizeof(address)) == 0)
 948		goto out_fail;
 949	rpcb->r_port = rpc_get_port(sap);
 950
 951	return 0;
 952
 953out_fail:
 954	dprintk("RPC: %5u malformed RPCB_%s reply\n",
 955			req->rq_task->tk_pid,
 956			req->rq_task->tk_msg.rpc_proc->p_name);
 957	return -EIO;
 958}
 959
 960/*
 961 * Not all rpcbind procedures described in RFC 1833 are implemented
 962 * since the Linux kernel RPC code requires only these.
 963 */
 964
 965static struct rpc_procinfo rpcb_procedures2[] = {
 966	[RPCBPROC_SET] = {
 967		.p_proc		= RPCBPROC_SET,
 968		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 969		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
 970		.p_arglen	= RPCB_mappingargs_sz,
 971		.p_replen	= RPCB_setres_sz,
 972		.p_statidx	= RPCBPROC_SET,
 973		.p_timer	= 0,
 974		.p_name		= "SET",
 975	},
 976	[RPCBPROC_UNSET] = {
 977		.p_proc		= RPCBPROC_UNSET,
 978		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 979		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
 980		.p_arglen	= RPCB_mappingargs_sz,
 981		.p_replen	= RPCB_setres_sz,
 982		.p_statidx	= RPCBPROC_UNSET,
 983		.p_timer	= 0,
 984		.p_name		= "UNSET",
 985	},
 986	[RPCBPROC_GETPORT] = {
 987		.p_proc		= RPCBPROC_GETPORT,
 988		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 989		.p_decode	= (kxdrdproc_t)rpcb_dec_getport,
 990		.p_arglen	= RPCB_mappingargs_sz,
 991		.p_replen	= RPCB_getportres_sz,
 992		.p_statidx	= RPCBPROC_GETPORT,
 993		.p_timer	= 0,
 994		.p_name		= "GETPORT",
 995	},
 996};
 997
 998static struct rpc_procinfo rpcb_procedures3[] = {
 999	[RPCBPROC_SET] = {
1000		.p_proc		= RPCBPROC_SET,
1001		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1002		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1003		.p_arglen	= RPCB_getaddrargs_sz,
1004		.p_replen	= RPCB_setres_sz,
1005		.p_statidx	= RPCBPROC_SET,
1006		.p_timer	= 0,
1007		.p_name		= "SET",
1008	},
1009	[RPCBPROC_UNSET] = {
1010		.p_proc		= RPCBPROC_UNSET,
1011		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1012		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1013		.p_arglen	= RPCB_getaddrargs_sz,
1014		.p_replen	= RPCB_setres_sz,
1015		.p_statidx	= RPCBPROC_UNSET,
1016		.p_timer	= 0,
1017		.p_name		= "UNSET",
1018	},
1019	[RPCBPROC_GETADDR] = {
1020		.p_proc		= RPCBPROC_GETADDR,
1021		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1022		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1023		.p_arglen	= RPCB_getaddrargs_sz,
1024		.p_replen	= RPCB_getaddrres_sz,
1025		.p_statidx	= RPCBPROC_GETADDR,
1026		.p_timer	= 0,
1027		.p_name		= "GETADDR",
1028	},
1029};
1030
1031static struct rpc_procinfo rpcb_procedures4[] = {
1032	[RPCBPROC_SET] = {
1033		.p_proc		= RPCBPROC_SET,
1034		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1035		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1036		.p_arglen	= RPCB_getaddrargs_sz,
1037		.p_replen	= RPCB_setres_sz,
1038		.p_statidx	= RPCBPROC_SET,
1039		.p_timer	= 0,
1040		.p_name		= "SET",
1041	},
1042	[RPCBPROC_UNSET] = {
1043		.p_proc		= RPCBPROC_UNSET,
1044		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1045		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1046		.p_arglen	= RPCB_getaddrargs_sz,
1047		.p_replen	= RPCB_setres_sz,
1048		.p_statidx	= RPCBPROC_UNSET,
1049		.p_timer	= 0,
1050		.p_name		= "UNSET",
1051	},
1052	[RPCBPROC_GETADDR] = {
1053		.p_proc		= RPCBPROC_GETADDR,
1054		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1055		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1056		.p_arglen	= RPCB_getaddrargs_sz,
1057		.p_replen	= RPCB_getaddrres_sz,
1058		.p_statidx	= RPCBPROC_GETADDR,
1059		.p_timer	= 0,
1060		.p_name		= "GETADDR",
1061	},
1062};
1063
1064static const struct rpcb_info rpcb_next_version[] = {
1065	{
1066		.rpc_vers	= RPCBVERS_2,
1067		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
1068	},
1069	{
1070		.rpc_proc	= NULL,
1071	},
1072};
1073
1074static const struct rpcb_info rpcb_next_version6[] = {
1075	{
1076		.rpc_vers	= RPCBVERS_4,
1077		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
1078	},
1079	{
1080		.rpc_vers	= RPCBVERS_3,
1081		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
1082	},
1083	{
1084		.rpc_proc	= NULL,
1085	},
1086};
1087
1088static const struct rpc_version rpcb_version2 = {
1089	.number		= RPCBVERS_2,
1090	.nrprocs	= ARRAY_SIZE(rpcb_procedures2),
1091	.procs		= rpcb_procedures2
1092};
1093
1094static const struct rpc_version rpcb_version3 = {
1095	.number		= RPCBVERS_3,
1096	.nrprocs	= ARRAY_SIZE(rpcb_procedures3),
1097	.procs		= rpcb_procedures3
1098};
1099
1100static const struct rpc_version rpcb_version4 = {
1101	.number		= RPCBVERS_4,
1102	.nrprocs	= ARRAY_SIZE(rpcb_procedures4),
1103	.procs		= rpcb_procedures4
1104};
1105
1106static const struct rpc_version *rpcb_version[] = {
1107	NULL,
1108	NULL,
1109	&rpcb_version2,
1110	&rpcb_version3,
1111	&rpcb_version4
1112};
1113
1114static struct rpc_stat rpcb_stats;
1115
1116static const struct rpc_program rpcb_program = {
1117	.name		= "rpcbind",
1118	.number		= RPCBIND_PROGRAM,
1119	.nrvers		= ARRAY_SIZE(rpcb_version),
1120	.version	= rpcb_version,
1121	.stats		= &rpcb_stats,
1122};
v4.10.11
   1/*
   2 * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
   3 * protocol
   4 *
   5 * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
   6 * RFC 3530: "Network File System (NFS) version 4 Protocol"
   7 *
   8 * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
   9 * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
  10 *
  11 * Descended from net/sunrpc/pmap_clnt.c,
  12 *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
  13 */
  14
  15#include <linux/module.h>
  16
  17#include <linux/types.h>
  18#include <linux/socket.h>
  19#include <linux/un.h>
  20#include <linux/in.h>
  21#include <linux/in6.h>
  22#include <linux/kernel.h>
  23#include <linux/errno.h>
  24#include <linux/mutex.h>
  25#include <linux/slab.h>
 
  26#include <net/ipv6.h>
  27
  28#include <linux/sunrpc/clnt.h>
  29#include <linux/sunrpc/addr.h>
  30#include <linux/sunrpc/sched.h>
  31#include <linux/sunrpc/xprtsock.h>
  32
  33#include "netns.h"
  34
  35#if IS_ENABLED(CONFIG_SUNRPC_DEBUG)
  36# define RPCDBG_FACILITY	RPCDBG_BIND
  37#endif
  38
  39#define RPCBIND_SOCK_PATHNAME	"/var/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
  48enum {
  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
 113static void			rpcb_getport_done(struct rpc_task *, void *);
 114static void			rpcb_map_release(void *data);
 115static const struct rpc_program	rpcb_program;
 116
 117struct 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
 131static struct rpc_procinfo rpcb_procedures2[];
 132static struct rpc_procinfo rpcb_procedures3[];
 133static struct rpc_procinfo rpcb_procedures4[];
 134
 135struct rpcb_info {
 136	u32			rpc_vers;
 137	struct rpc_procinfo *	rpc_proc;
 138};
 139
 140static const struct rpcb_info rpcb_next_version[];
 141static const struct rpcb_info rpcb_next_version6[];
 142
 143static const struct rpc_call_ops rpcb_getport_ops = {
 144	.rpc_call_done		= rpcb_getport_done,
 145	.rpc_release		= rpcb_map_release,
 146};
 147
 148static 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
 154static 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
 164static 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
 178void 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
 206static 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	dprintk("RPC:       created new rpcb local clients (rpcb_local_clnt: "
 219			"%p, rpcb_local_clnt4: %p) for net %p%s\n",
 220			sn->rpcb_local_clnt, sn->rpcb_local_clnt4,
 221			net, (net == &init_net) ? " (init_net)" : "");
 222}
 223
 224/*
 225 * Returns zero on success, otherwise a negative errno value
 226 * is returned.
 227 */
 228static int rpcb_create_local_unix(struct net *net)
 229{
 230	static const struct sockaddr_un rpcb_localaddr_rpcbind = {
 231		.sun_family		= AF_LOCAL,
 232		.sun_path		= RPCBIND_SOCK_PATHNAME,
 233	};
 234	struct rpc_create_args args = {
 235		.net		= net,
 236		.protocol	= XPRT_TRANSPORT_LOCAL,
 237		.address	= (struct sockaddr *)&rpcb_localaddr_rpcbind,
 238		.addrsize	= sizeof(rpcb_localaddr_rpcbind),
 239		.servername	= "localhost",
 240		.program	= &rpcb_program,
 241		.version	= RPCBVERS_2,
 242		.authflavor	= RPC_AUTH_NULL,
 243		/*
 244		 * We turn off the idle timeout to prevent the kernel
 245		 * from automatically disconnecting the socket.
 246		 * Otherwise, we'd have to cache the mount namespace
 247		 * of the caller and somehow pass that to the socket
 248		 * reconnect code.
 249		 */
 250		.flags		= RPC_CLNT_CREATE_NO_IDLE_TIMEOUT,
 251	};
 252	struct rpc_clnt *clnt, *clnt4;
 253	int result = 0;
 254
 255	/*
 256	 * Because we requested an RPC PING at transport creation time,
 257	 * this works only if the user space portmapper is rpcbind, and
 258	 * it's listening on AF_LOCAL on the named socket.
 259	 */
 260	clnt = rpc_create(&args);
 261	if (IS_ERR(clnt)) {
 262		dprintk("RPC:       failed to create AF_LOCAL rpcbind "
 263				"client (errno %ld).\n", PTR_ERR(clnt));
 264		result = PTR_ERR(clnt);
 265		goto out;
 266	}
 267
 268	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 269	if (IS_ERR(clnt4)) {
 270		dprintk("RPC:       failed to bind second program to "
 271				"rpcbind v4 client (errno %ld).\n",
 272				PTR_ERR(clnt4));
 273		clnt4 = NULL;
 274	}
 275
 276	rpcb_set_local(net, clnt, clnt4, true);
 277
 278out:
 279	return result;
 280}
 281
 282/*
 283 * Returns zero on success, otherwise a negative errno value
 284 * is returned.
 285 */
 286static int rpcb_create_local_net(struct net *net)
 287{
 288	static const struct sockaddr_in rpcb_inaddr_loopback = {
 289		.sin_family		= AF_INET,
 290		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
 291		.sin_port		= htons(RPCBIND_PORT),
 292	};
 293	struct rpc_create_args args = {
 294		.net		= net,
 295		.protocol	= XPRT_TRANSPORT_TCP,
 296		.address	= (struct sockaddr *)&rpcb_inaddr_loopback,
 297		.addrsize	= sizeof(rpcb_inaddr_loopback),
 298		.servername	= "localhost",
 299		.program	= &rpcb_program,
 300		.version	= RPCBVERS_2,
 301		.authflavor	= RPC_AUTH_UNIX,
 302		.flags		= RPC_CLNT_CREATE_NOPING,
 303	};
 304	struct rpc_clnt *clnt, *clnt4;
 305	int result = 0;
 306
 307	clnt = rpc_create(&args);
 308	if (IS_ERR(clnt)) {
 309		dprintk("RPC:       failed to create local rpcbind "
 310				"client (errno %ld).\n", PTR_ERR(clnt));
 311		result = PTR_ERR(clnt);
 312		goto out;
 313	}
 314
 315	/*
 316	 * This results in an RPC ping.  On systems running portmapper,
 317	 * the v4 ping will fail.  Proceed anyway, but disallow rpcb
 318	 * v4 upcalls.
 319	 */
 320	clnt4 = rpc_bind_new_program(clnt, &rpcb_program, RPCBVERS_4);
 321	if (IS_ERR(clnt4)) {
 322		dprintk("RPC:       failed to bind second program to "
 323				"rpcbind v4 client (errno %ld).\n",
 324				PTR_ERR(clnt4));
 325		clnt4 = NULL;
 326	}
 327
 328	rpcb_set_local(net, clnt, clnt4, false);
 329
 330out:
 331	return result;
 332}
 333
 334/*
 335 * Returns zero on success, otherwise a negative errno value
 336 * is returned.
 337 */
 338int rpcb_create_local(struct net *net)
 339{
 340	static DEFINE_MUTEX(rpcb_create_local_mutex);
 341	int result = 0;
 342
 343	if (rpcb_get_local(net))
 344		return result;
 345
 346	mutex_lock(&rpcb_create_local_mutex);
 347	if (rpcb_get_local(net))
 348		goto out;
 349
 350	if (rpcb_create_local_unix(net) != 0)
 351		result = rpcb_create_local_net(net);
 352
 353out:
 354	mutex_unlock(&rpcb_create_local_mutex);
 355	return result;
 356}
 357
 358static struct rpc_clnt *rpcb_create(struct net *net, const char *nodename,
 359				    const char *hostname,
 360				    struct sockaddr *srvaddr, size_t salen,
 361				    int proto, u32 version)
 362{
 363	struct rpc_create_args args = {
 364		.net		= net,
 365		.protocol	= proto,
 366		.address	= srvaddr,
 367		.addrsize	= salen,
 368		.servername	= hostname,
 369		.nodename	= nodename,
 370		.program	= &rpcb_program,
 371		.version	= version,
 372		.authflavor	= RPC_AUTH_UNIX,
 373		.flags		= (RPC_CLNT_CREATE_NOPING |
 374					RPC_CLNT_CREATE_NONPRIVPORT),
 375	};
 376
 377	switch (srvaddr->sa_family) {
 378	case AF_INET:
 379		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 380		break;
 381	case AF_INET6:
 382		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 383		break;
 384	default:
 385		return ERR_PTR(-EAFNOSUPPORT);
 386	}
 387
 388	return rpc_create(&args);
 389}
 390
 391static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
 392{
 393	int flags = RPC_TASK_NOCONNECT;
 394	int error, result = 0;
 395
 396	if (is_set || !sn->rpcb_is_af_local)
 397		flags = RPC_TASK_SOFTCONN;
 398	msg->rpc_resp = &result;
 399
 400	error = rpc_call_sync(clnt, msg, flags);
 401	if (error < 0) {
 402		dprintk("RPC:       failed to contact local rpcbind "
 403				"server (errno %d).\n", -error);
 404		return error;
 405	}
 406
 407	if (!result)
 408		return -EACCES;
 409	return 0;
 410}
 411
 412/**
 413 * rpcb_register - set or unset a port registration with the local rpcbind svc
 414 * @net: target network namespace
 415 * @prog: RPC program number to bind
 416 * @vers: RPC version number to bind
 417 * @prot: transport protocol to register
 418 * @port: port value to register
 419 *
 420 * Returns zero if the registration request was dispatched successfully
 421 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 422 * value that reflects the nature of the error (request could not be
 423 * dispatched, timed out, or rpcbind returned an error).
 424 *
 425 * RPC services invoke this function to advertise their contact
 426 * information via the system's rpcbind daemon.  RPC services
 427 * invoke this function once for each [program, version, transport]
 428 * tuple they wish to advertise.
 429 *
 430 * Callers may also unregister RPC services that are no longer
 431 * available by setting the passed-in port to zero.  This removes
 432 * all registered transports for [program, version] from the local
 433 * rpcbind database.
 434 *
 435 * This function uses rpcbind protocol version 2 to contact the
 436 * local rpcbind daemon.
 437 *
 438 * Registration works over both AF_INET and AF_INET6, and services
 439 * registered via this function are advertised as available for any
 440 * address.  If the local rpcbind daemon is listening on AF_INET6,
 441 * services registered via this function will be advertised on
 442 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 443 * addresses).
 444 */
 445int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 446{
 447	struct rpcbind_args map = {
 448		.r_prog		= prog,
 449		.r_vers		= vers,
 450		.r_prot		= prot,
 451		.r_port		= port,
 452	};
 453	struct rpc_message msg = {
 454		.rpc_argp	= &map,
 455	};
 456	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 457	bool is_set = false;
 458
 459	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 460			"rpcbind\n", (port ? "" : "un"),
 461			prog, vers, prot, port);
 462
 463	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 464	if (port != 0) {
 465		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 466		is_set = true;
 467	}
 468
 469	return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
 470}
 471
 472/*
 473 * Fill in AF_INET family-specific arguments to register
 474 */
 475static int rpcb_register_inet4(struct sunrpc_net *sn,
 476			       const struct sockaddr *sap,
 477			       struct rpc_message *msg)
 478{
 479	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 480	struct rpcbind_args *map = msg->rpc_argp;
 481	unsigned short port = ntohs(sin->sin_port);
 482	bool is_set = false;
 483	int result;
 484
 485	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 486
 487	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 488		"local rpcbind\n", (port ? "" : "un"),
 489			map->r_prog, map->r_vers,
 490			map->r_addr, map->r_netid);
 491
 492	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 493	if (port != 0) {
 494		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 495		is_set = true;
 496	}
 497
 498	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 499	kfree(map->r_addr);
 500	return result;
 501}
 502
 503/*
 504 * Fill in AF_INET6 family-specific arguments to register
 505 */
 506static int rpcb_register_inet6(struct sunrpc_net *sn,
 507			       const struct sockaddr *sap,
 508			       struct rpc_message *msg)
 509{
 510	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 511	struct rpcbind_args *map = msg->rpc_argp;
 512	unsigned short port = ntohs(sin6->sin6_port);
 513	bool is_set = false;
 514	int result;
 515
 516	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 517
 518	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 519		"local rpcbind\n", (port ? "" : "un"),
 520			map->r_prog, map->r_vers,
 521			map->r_addr, map->r_netid);
 522
 523	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 524	if (port != 0) {
 525		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 526		is_set = true;
 527	}
 528
 529	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 530	kfree(map->r_addr);
 531	return result;
 532}
 533
 534static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 535					     struct rpc_message *msg)
 536{
 537	struct rpcbind_args *map = msg->rpc_argp;
 538
 539	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 540		"local rpcbind\n",
 541			map->r_prog, map->r_vers, map->r_netid);
 542
 543	map->r_addr = "";
 544	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 545
 546	return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
 547}
 548
 549/**
 550 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 551 * @net: target network namespace
 552 * @program: RPC program number of service to (un)register
 553 * @version: RPC version number of service to (un)register
 554 * @address: address family, IP address, and port to (un)register
 555 * @netid: netid of transport protocol to (un)register
 556 *
 557 * Returns zero if the registration request was dispatched successfully
 558 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 559 * value that reflects the nature of the error (request could not be
 560 * dispatched, timed out, or rpcbind returned an error).
 561 *
 562 * RPC services invoke this function to advertise their contact
 563 * information via the system's rpcbind daemon.  RPC services
 564 * invoke this function once for each [program, version, address,
 565 * netid] tuple they wish to advertise.
 566 *
 567 * Callers may also unregister RPC services that are registered at a
 568 * specific address by setting the port number in @address to zero.
 569 * They may unregister all registered protocol families at once for
 570 * a service by passing a NULL @address argument.  If @netid is ""
 571 * then all netids for [program, version, address] are unregistered.
 572 *
 573 * This function uses rpcbind protocol version 4 to contact the
 574 * local rpcbind daemon.  The local rpcbind daemon must support
 575 * version 4 of the rpcbind protocol in order for these functions
 576 * to register a service successfully.
 577 *
 578 * Supported netids include "udp" and "tcp" for UDP and TCP over
 579 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 580 * respectively.
 581 *
 582 * The contents of @address determine the address family and the
 583 * port to be registered.  The usual practice is to pass INADDR_ANY
 584 * as the raw address, but specifying a non-zero address is also
 585 * supported by this API if the caller wishes to advertise an RPC
 586 * service on a specific network interface.
 587 *
 588 * Note that passing in INADDR_ANY does not create the same service
 589 * registration as IN6ADDR_ANY.  The former advertises an RPC
 590 * service on any IPv4 address, but not on IPv6.  The latter
 591 * advertises the service on all IPv4 and IPv6 addresses.
 592 */
 593int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 594		     const struct sockaddr *address, const char *netid)
 595{
 596	struct rpcbind_args map = {
 597		.r_prog		= program,
 598		.r_vers		= version,
 599		.r_netid	= netid,
 600		.r_owner	= RPCB_OWNER_STRING,
 601	};
 602	struct rpc_message msg = {
 603		.rpc_argp	= &map,
 604	};
 605	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 606
 607	if (sn->rpcb_local_clnt4 == NULL)
 608		return -EPROTONOSUPPORT;
 609
 610	if (address == NULL)
 611		return rpcb_unregister_all_protofamilies(sn, &msg);
 612
 613	switch (address->sa_family) {
 614	case AF_INET:
 615		return rpcb_register_inet4(sn, address, &msg);
 616	case AF_INET6:
 617		return rpcb_register_inet6(sn, address, &msg);
 618	}
 619
 620	return -EAFNOSUPPORT;
 621}
 622
 623static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 624{
 625	struct rpc_message msg = {
 626		.rpc_proc = proc,
 627		.rpc_argp = map,
 628		.rpc_resp = map,
 629	};
 630	struct rpc_task_setup task_setup_data = {
 631		.rpc_client = rpcb_clnt,
 632		.rpc_message = &msg,
 633		.callback_ops = &rpcb_getport_ops,
 634		.callback_data = map,
 635		.flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 636	};
 637
 638	return rpc_run_task(&task_setup_data);
 639}
 640
 641/*
 642 * In the case where rpc clients have been cloned, we want to make
 643 * sure that we use the program number/version etc of the actual
 644 * owner of the xprt. To do so, we walk back up the tree of parents
 645 * to find whoever created the transport and/or whoever has the
 646 * autobind flag set.
 647 */
 648static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 649{
 650	struct rpc_clnt *parent = clnt->cl_parent;
 651	struct rpc_xprt_switch *xps = rcu_access_pointer(clnt->cl_xpi.xpi_xpswitch);
 652
 653	while (parent != clnt) {
 654		if (rcu_access_pointer(parent->cl_xpi.xpi_xpswitch) != xps)
 655			break;
 656		if (clnt->cl_autobind)
 657			break;
 658		clnt = parent;
 659		parent = parent->cl_parent;
 660	}
 661	return clnt;
 662}
 663
 664/**
 665 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 666 * @task: task that is waiting for portmapper request
 667 *
 668 * This one can be called for an ongoing RPC request, and can be used in
 669 * an async (rpciod) context.
 670 */
 671void rpcb_getport_async(struct rpc_task *task)
 672{
 673	struct rpc_clnt *clnt;
 674	struct rpc_procinfo *proc;
 675	u32 bind_version;
 676	struct rpc_xprt *xprt;
 677	struct rpc_clnt	*rpcb_clnt;
 678	struct rpcbind_args *map;
 679	struct rpc_task	*child;
 680	struct sockaddr_storage addr;
 681	struct sockaddr *sap = (struct sockaddr *)&addr;
 682	size_t salen;
 683	int status;
 684
 685	rcu_read_lock();
 686	clnt = rpcb_find_transport_owner(task->tk_client);
 
 
 
 687	rcu_read_unlock();
 688	xprt = xprt_get(task->tk_xprt);
 689
 690	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
 691		task->tk_pid, __func__,
 692		xprt->servername, clnt->cl_prog, clnt->cl_vers, xprt->prot);
 693
 694	/* Put self on the wait queue to ensure we get notified if
 695	 * some other task is already attempting to bind the port */
 696	rpc_sleep_on(&xprt->binding, task, NULL);
 697
 698	if (xprt_test_and_set_binding(xprt)) {
 699		dprintk("RPC: %5u %s: waiting for another binder\n",
 700			task->tk_pid, __func__);
 701		xprt_put(xprt);
 702		return;
 703	}
 704
 705	/* Someone else may have bound if we slept */
 706	if (xprt_bound(xprt)) {
 707		status = 0;
 708		dprintk("RPC: %5u %s: already bound\n",
 709			task->tk_pid, __func__);
 710		goto bailout_nofree;
 711	}
 712
 713	/* Parent transport's destination address */
 714	salen = rpc_peeraddr(clnt, sap, sizeof(addr));
 715
 716	/* Don't ever use rpcbind v2 for AF_INET6 requests */
 717	switch (sap->sa_family) {
 718	case AF_INET:
 719		proc = rpcb_next_version[xprt->bind_index].rpc_proc;
 720		bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
 721		break;
 722	case AF_INET6:
 723		proc = rpcb_next_version6[xprt->bind_index].rpc_proc;
 724		bind_version = rpcb_next_version6[xprt->bind_index].rpc_vers;
 725		break;
 726	default:
 727		status = -EAFNOSUPPORT;
 728		dprintk("RPC: %5u %s: bad address family\n",
 729				task->tk_pid, __func__);
 730		goto bailout_nofree;
 731	}
 732	if (proc == NULL) {
 733		xprt->bind_index = 0;
 734		status = -EPFNOSUPPORT;
 735		dprintk("RPC: %5u %s: no more getport versions available\n",
 736			task->tk_pid, __func__);
 737		goto bailout_nofree;
 738	}
 739
 740	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
 741		task->tk_pid, __func__, bind_version);
 742
 743	rpcb_clnt = rpcb_create(xprt->xprt_net,
 744				clnt->cl_nodename,
 745				xprt->servername, sap, salen,
 746				xprt->prot, bind_version);
 747	if (IS_ERR(rpcb_clnt)) {
 748		status = PTR_ERR(rpcb_clnt);
 749		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 750			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 751		goto bailout_nofree;
 752	}
 753
 754	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 755	if (!map) {
 756		status = -ENOMEM;
 757		dprintk("RPC: %5u %s: no memory available\n",
 758			task->tk_pid, __func__);
 759		goto bailout_release_client;
 760	}
 761	map->r_prog = clnt->cl_prog;
 762	map->r_vers = clnt->cl_vers;
 763	map->r_prot = xprt->prot;
 764	map->r_port = 0;
 765	map->r_xprt = xprt;
 766	map->r_status = -EIO;
 767
 768	switch (bind_version) {
 769	case RPCBVERS_4:
 770	case RPCBVERS_3:
 771		map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 772		map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 773		map->r_owner = "";
 774		break;
 775	case RPCBVERS_2:
 776		map->r_addr = NULL;
 777		break;
 778	default:
 779		BUG();
 780	}
 781
 782	child = rpcb_call_async(rpcb_clnt, map, proc);
 783	rpc_release_client(rpcb_clnt);
 784	if (IS_ERR(child)) {
 785		/* rpcb_map_release() has freed the arguments */
 786		dprintk("RPC: %5u %s: rpc_run_task failed\n",
 787			task->tk_pid, __func__);
 788		return;
 789	}
 790
 791	xprt->stat.bind_count++;
 792	rpc_put_task(child);
 793	return;
 794
 795bailout_release_client:
 796	rpc_release_client(rpcb_clnt);
 797bailout_nofree:
 798	rpcb_wake_rpcbind_waiters(xprt, status);
 799	task->tk_status = status;
 800	xprt_put(xprt);
 801}
 802EXPORT_SYMBOL_GPL(rpcb_getport_async);
 803
 804/*
 805 * Rpcbind child task calls this callback via tk_exit.
 806 */
 807static void rpcb_getport_done(struct rpc_task *child, void *data)
 808{
 809	struct rpcbind_args *map = data;
 810	struct rpc_xprt *xprt = map->r_xprt;
 811	int status = child->tk_status;
 812
 813	/* Garbage reply: retry with a lesser rpcbind version */
 814	if (status == -EIO)
 815		status = -EPROTONOSUPPORT;
 816
 817	/* rpcbind server doesn't support this rpcbind protocol version */
 818	if (status == -EPROTONOSUPPORT)
 819		xprt->bind_index++;
 820
 821	if (status < 0) {
 822		/* rpcbind server not available on remote host? */
 823		xprt->ops->set_port(xprt, 0);
 824	} else if (map->r_port == 0) {
 825		/* Requested RPC service wasn't registered on remote host */
 826		xprt->ops->set_port(xprt, 0);
 827		status = -EACCES;
 828	} else {
 829		/* Succeeded */
 830		xprt->ops->set_port(xprt, map->r_port);
 831		xprt_set_bound(xprt);
 832		status = 0;
 833	}
 834
 835	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 836			child->tk_pid, status, map->r_port);
 837
 838	map->r_status = status;
 839}
 840
 841/*
 842 * XDR functions for rpcbind
 843 */
 844
 845static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 846			     const struct rpcbind_args *rpcb)
 847{
 848	__be32 *p;
 849
 850	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 851			req->rq_task->tk_pid,
 852			req->rq_task->tk_msg.rpc_proc->p_name,
 853			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 854
 855	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 856	*p++ = cpu_to_be32(rpcb->r_prog);
 857	*p++ = cpu_to_be32(rpcb->r_vers);
 858	*p++ = cpu_to_be32(rpcb->r_prot);
 859	*p   = cpu_to_be32(rpcb->r_port);
 860}
 861
 862static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 863			    struct rpcbind_args *rpcb)
 864{
 865	unsigned long port;
 866	__be32 *p;
 867
 868	rpcb->r_port = 0;
 869
 870	p = xdr_inline_decode(xdr, 4);
 871	if (unlikely(p == NULL))
 872		return -EIO;
 873
 874	port = be32_to_cpup(p);
 875	dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 876			req->rq_task->tk_msg.rpc_proc->p_name, port);
 877	if (unlikely(port > USHRT_MAX))
 878		return -EIO;
 879
 880	rpcb->r_port = port;
 881	return 0;
 882}
 883
 884static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 885			unsigned int *boolp)
 886{
 887	__be32 *p;
 888
 889	p = xdr_inline_decode(xdr, 4);
 890	if (unlikely(p == NULL))
 891		return -EIO;
 892
 893	*boolp = 0;
 894	if (*p != xdr_zero)
 895		*boolp = 1;
 896
 897	dprintk("RPC: %5u RPCB_%s call %s\n",
 898			req->rq_task->tk_pid,
 899			req->rq_task->tk_msg.rpc_proc->p_name,
 900			(*boolp ? "succeeded" : "failed"));
 901	return 0;
 902}
 903
 904static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 905			       const u32 maxstrlen)
 906{
 907	__be32 *p;
 908	u32 len;
 909
 910	len = strlen(string);
 911	WARN_ON_ONCE(len > maxstrlen);
 912	if (len > maxstrlen)
 913		/* truncate and hope for the best */
 914		len = maxstrlen;
 915	p = xdr_reserve_space(xdr, 4 + len);
 916	xdr_encode_opaque(p, string, len);
 917}
 918
 919static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 920			     const struct rpcbind_args *rpcb)
 921{
 922	__be32 *p;
 923
 924	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 925			req->rq_task->tk_pid,
 926			req->rq_task->tk_msg.rpc_proc->p_name,
 927			rpcb->r_prog, rpcb->r_vers,
 928			rpcb->r_netid, rpcb->r_addr);
 929
 930	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 931	*p++ = cpu_to_be32(rpcb->r_prog);
 932	*p = cpu_to_be32(rpcb->r_vers);
 933
 934	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 935	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 936	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 937}
 938
 939static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 940			    struct rpcbind_args *rpcb)
 941{
 942	struct sockaddr_storage address;
 943	struct sockaddr *sap = (struct sockaddr *)&address;
 944	__be32 *p;
 945	u32 len;
 946
 947	rpcb->r_port = 0;
 948
 949	p = xdr_inline_decode(xdr, 4);
 950	if (unlikely(p == NULL))
 951		goto out_fail;
 952	len = be32_to_cpup(p);
 953
 954	/*
 955	 * If the returned universal address is a null string,
 956	 * the requested RPC service was not registered.
 957	 */
 958	if (len == 0) {
 959		dprintk("RPC: %5u RPCB reply: program not registered\n",
 960				req->rq_task->tk_pid);
 961		return 0;
 962	}
 963
 964	if (unlikely(len > RPCBIND_MAXUADDRLEN))
 965		goto out_fail;
 966
 967	p = xdr_inline_decode(xdr, len);
 968	if (unlikely(p == NULL))
 969		goto out_fail;
 970	dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 971			req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 972
 973	if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 974				sap, sizeof(address)) == 0)
 975		goto out_fail;
 976	rpcb->r_port = rpc_get_port(sap);
 977
 978	return 0;
 979
 980out_fail:
 981	dprintk("RPC: %5u malformed RPCB_%s reply\n",
 982			req->rq_task->tk_pid,
 983			req->rq_task->tk_msg.rpc_proc->p_name);
 984	return -EIO;
 985}
 986
 987/*
 988 * Not all rpcbind procedures described in RFC 1833 are implemented
 989 * since the Linux kernel RPC code requires only these.
 990 */
 991
 992static struct rpc_procinfo rpcb_procedures2[] = {
 993	[RPCBPROC_SET] = {
 994		.p_proc		= RPCBPROC_SET,
 995		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 996		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
 997		.p_arglen	= RPCB_mappingargs_sz,
 998		.p_replen	= RPCB_setres_sz,
 999		.p_statidx	= RPCBPROC_SET,
1000		.p_timer	= 0,
1001		.p_name		= "SET",
1002	},
1003	[RPCBPROC_UNSET] = {
1004		.p_proc		= RPCBPROC_UNSET,
1005		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
1006		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1007		.p_arglen	= RPCB_mappingargs_sz,
1008		.p_replen	= RPCB_setres_sz,
1009		.p_statidx	= RPCBPROC_UNSET,
1010		.p_timer	= 0,
1011		.p_name		= "UNSET",
1012	},
1013	[RPCBPROC_GETPORT] = {
1014		.p_proc		= RPCBPROC_GETPORT,
1015		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
1016		.p_decode	= (kxdrdproc_t)rpcb_dec_getport,
1017		.p_arglen	= RPCB_mappingargs_sz,
1018		.p_replen	= RPCB_getportres_sz,
1019		.p_statidx	= RPCBPROC_GETPORT,
1020		.p_timer	= 0,
1021		.p_name		= "GETPORT",
1022	},
1023};
1024
1025static struct rpc_procinfo rpcb_procedures3[] = {
1026	[RPCBPROC_SET] = {
1027		.p_proc		= RPCBPROC_SET,
1028		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1029		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1030		.p_arglen	= RPCB_getaddrargs_sz,
1031		.p_replen	= RPCB_setres_sz,
1032		.p_statidx	= RPCBPROC_SET,
1033		.p_timer	= 0,
1034		.p_name		= "SET",
1035	},
1036	[RPCBPROC_UNSET] = {
1037		.p_proc		= RPCBPROC_UNSET,
1038		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1039		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1040		.p_arglen	= RPCB_getaddrargs_sz,
1041		.p_replen	= RPCB_setres_sz,
1042		.p_statidx	= RPCBPROC_UNSET,
1043		.p_timer	= 0,
1044		.p_name		= "UNSET",
1045	},
1046	[RPCBPROC_GETADDR] = {
1047		.p_proc		= RPCBPROC_GETADDR,
1048		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1049		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1050		.p_arglen	= RPCB_getaddrargs_sz,
1051		.p_replen	= RPCB_getaddrres_sz,
1052		.p_statidx	= RPCBPROC_GETADDR,
1053		.p_timer	= 0,
1054		.p_name		= "GETADDR",
1055	},
1056};
1057
1058static struct rpc_procinfo rpcb_procedures4[] = {
1059	[RPCBPROC_SET] = {
1060		.p_proc		= RPCBPROC_SET,
1061		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1062		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1063		.p_arglen	= RPCB_getaddrargs_sz,
1064		.p_replen	= RPCB_setres_sz,
1065		.p_statidx	= RPCBPROC_SET,
1066		.p_timer	= 0,
1067		.p_name		= "SET",
1068	},
1069	[RPCBPROC_UNSET] = {
1070		.p_proc		= RPCBPROC_UNSET,
1071		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1072		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1073		.p_arglen	= RPCB_getaddrargs_sz,
1074		.p_replen	= RPCB_setres_sz,
1075		.p_statidx	= RPCBPROC_UNSET,
1076		.p_timer	= 0,
1077		.p_name		= "UNSET",
1078	},
1079	[RPCBPROC_GETADDR] = {
1080		.p_proc		= RPCBPROC_GETADDR,
1081		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1082		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1083		.p_arglen	= RPCB_getaddrargs_sz,
1084		.p_replen	= RPCB_getaddrres_sz,
1085		.p_statidx	= RPCBPROC_GETADDR,
1086		.p_timer	= 0,
1087		.p_name		= "GETADDR",
1088	},
1089};
1090
1091static const struct rpcb_info rpcb_next_version[] = {
1092	{
1093		.rpc_vers	= RPCBVERS_2,
1094		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
1095	},
1096	{
1097		.rpc_proc	= NULL,
1098	},
1099};
1100
1101static const struct rpcb_info rpcb_next_version6[] = {
1102	{
1103		.rpc_vers	= RPCBVERS_4,
1104		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
1105	},
1106	{
1107		.rpc_vers	= RPCBVERS_3,
1108		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
1109	},
1110	{
1111		.rpc_proc	= NULL,
1112	},
1113};
1114
1115static const struct rpc_version rpcb_version2 = {
1116	.number		= RPCBVERS_2,
1117	.nrprocs	= ARRAY_SIZE(rpcb_procedures2),
1118	.procs		= rpcb_procedures2
1119};
1120
1121static const struct rpc_version rpcb_version3 = {
1122	.number		= RPCBVERS_3,
1123	.nrprocs	= ARRAY_SIZE(rpcb_procedures3),
1124	.procs		= rpcb_procedures3
1125};
1126
1127static const struct rpc_version rpcb_version4 = {
1128	.number		= RPCBVERS_4,
1129	.nrprocs	= ARRAY_SIZE(rpcb_procedures4),
1130	.procs		= rpcb_procedures4
1131};
1132
1133static const struct rpc_version *rpcb_version[] = {
1134	NULL,
1135	NULL,
1136	&rpcb_version2,
1137	&rpcb_version3,
1138	&rpcb_version4
1139};
1140
1141static struct rpc_stat rpcb_stats;
1142
1143static const struct rpc_program rpcb_program = {
1144	.name		= "rpcbind",
1145	.number		= RPCBIND_PROGRAM,
1146	.nrvers		= ARRAY_SIZE(rpcb_version),
1147	.version	= rpcb_version,
1148	.stats		= &rpcb_stats,
1149};