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v5.4
   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	if (IS_ERR(child)) {
 799		/* rpcb_map_release() has freed the arguments */
 800		dprintk("RPC: %5u %s: rpc_run_task failed\n",
 801			task->tk_pid, __func__);
 802		return;
 803	}
 804
 805	xprt->stat.bind_count++;
 806	rpc_put_task(child);
 807	return;
 808
 809bailout_free_args:
 810	kfree(map);
 811bailout_release_client:
 812	rpc_release_client(rpcb_clnt);
 813bailout_nofree:
 814	rpcb_wake_rpcbind_waiters(xprt, status);
 815	task->tk_status = status;
 816	xprt_put(xprt);
 817}
 818EXPORT_SYMBOL_GPL(rpcb_getport_async);
 819
 820/*
 821 * Rpcbind child task calls this callback via tk_exit.
 822 */
 823static void rpcb_getport_done(struct rpc_task *child, void *data)
 824{
 825	struct rpcbind_args *map = data;
 826	struct rpc_xprt *xprt = map->r_xprt;
 827	int status = child->tk_status;
 828
 829	/* Garbage reply: retry with a lesser rpcbind version */
 830	if (status == -EIO)
 831		status = -EPROTONOSUPPORT;
 832
 833	/* rpcbind server doesn't support this rpcbind protocol version */
 834	if (status == -EPROTONOSUPPORT)
 835		xprt->bind_index++;
 836
 837	if (status < 0) {
 838		/* rpcbind server not available on remote host? */
 839		xprt->ops->set_port(xprt, 0);
 840	} else if (map->r_port == 0) {
 841		/* Requested RPC service wasn't registered on remote host */
 842		xprt->ops->set_port(xprt, 0);
 843		status = -EACCES;
 844	} else {
 845		/* Succeeded */
 846		xprt->ops->set_port(xprt, map->r_port);
 847		xprt_set_bound(xprt);
 848		status = 0;
 849	}
 850
 851	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 852			child->tk_pid, status, map->r_port);
 853
 854	map->r_status = status;
 855}
 856
 857/*
 858 * XDR functions for rpcbind
 859 */
 860
 861static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 862			     const void *data)
 863{
 864	const struct rpcbind_args *rpcb = data;
 865	__be32 *p;
 866
 867	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 868			req->rq_task->tk_pid,
 869			req->rq_task->tk_msg.rpc_proc->p_name,
 870			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 871
 872	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 873	*p++ = cpu_to_be32(rpcb->r_prog);
 874	*p++ = cpu_to_be32(rpcb->r_vers);
 875	*p++ = cpu_to_be32(rpcb->r_prot);
 876	*p   = cpu_to_be32(rpcb->r_port);
 877}
 878
 879static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 880			    void *data)
 881{
 882	struct rpcbind_args *rpcb = data;
 883	unsigned long port;
 884	__be32 *p;
 885
 886	rpcb->r_port = 0;
 887
 888	p = xdr_inline_decode(xdr, 4);
 889	if (unlikely(p == NULL))
 890		return -EIO;
 891
 892	port = be32_to_cpup(p);
 893	dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 894			req->rq_task->tk_msg.rpc_proc->p_name, port);
 895	if (unlikely(port > USHRT_MAX))
 896		return -EIO;
 897
 898	rpcb->r_port = port;
 899	return 0;
 900}
 901
 902static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 903			void *data)
 904{
 905	unsigned int *boolp = data;
 906	__be32 *p;
 907
 908	p = xdr_inline_decode(xdr, 4);
 909	if (unlikely(p == NULL))
 910		return -EIO;
 911
 912	*boolp = 0;
 913	if (*p != xdr_zero)
 914		*boolp = 1;
 915
 916	dprintk("RPC: %5u RPCB_%s call %s\n",
 917			req->rq_task->tk_pid,
 918			req->rq_task->tk_msg.rpc_proc->p_name,
 919			(*boolp ? "succeeded" : "failed"));
 920	return 0;
 921}
 922
 923static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 924			       const u32 maxstrlen)
 925{
 926	__be32 *p;
 927	u32 len;
 928
 929	len = strlen(string);
 930	WARN_ON_ONCE(len > maxstrlen);
 931	if (len > maxstrlen)
 932		/* truncate and hope for the best */
 933		len = maxstrlen;
 934	p = xdr_reserve_space(xdr, 4 + len);
 935	xdr_encode_opaque(p, string, len);
 936}
 937
 938static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 939			     const void *data)
 940{
 941	const struct rpcbind_args *rpcb = data;
 942	__be32 *p;
 943
 944	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 945			req->rq_task->tk_pid,
 946			req->rq_task->tk_msg.rpc_proc->p_name,
 947			rpcb->r_prog, rpcb->r_vers,
 948			rpcb->r_netid, rpcb->r_addr);
 949
 950	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 951	*p++ = cpu_to_be32(rpcb->r_prog);
 952	*p = cpu_to_be32(rpcb->r_vers);
 953
 954	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 955	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 956	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 957}
 958
 959static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 960			    void *data)
 961{
 962	struct rpcbind_args *rpcb = data;
 963	struct sockaddr_storage address;
 964	struct sockaddr *sap = (struct sockaddr *)&address;
 965	__be32 *p;
 966	u32 len;
 967
 968	rpcb->r_port = 0;
 969
 970	p = xdr_inline_decode(xdr, 4);
 971	if (unlikely(p == NULL))
 972		goto out_fail;
 973	len = be32_to_cpup(p);
 974
 975	/*
 976	 * If the returned universal address is a null string,
 977	 * the requested RPC service was not registered.
 978	 */
 979	if (len == 0) {
 980		dprintk("RPC: %5u RPCB reply: program not registered\n",
 981				req->rq_task->tk_pid);
 982		return 0;
 983	}
 984
 985	if (unlikely(len > RPCBIND_MAXUADDRLEN))
 986		goto out_fail;
 987
 988	p = xdr_inline_decode(xdr, len);
 989	if (unlikely(p == NULL))
 990		goto out_fail;
 991	dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 992			req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 993
 994	if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 995				sap, sizeof(address)) == 0)
 996		goto out_fail;
 997	rpcb->r_port = rpc_get_port(sap);
 998
 999	return 0;
1000
1001out_fail:
1002	dprintk("RPC: %5u malformed RPCB_%s reply\n",
1003			req->rq_task->tk_pid,
1004			req->rq_task->tk_msg.rpc_proc->p_name);
1005	return -EIO;
1006}
1007
1008/*
1009 * Not all rpcbind procedures described in RFC 1833 are implemented
1010 * since the Linux kernel RPC code requires only these.
1011 */
1012
1013static const struct rpc_procinfo rpcb_procedures2[] = {
1014	[RPCBPROC_SET] = {
1015		.p_proc		= RPCBPROC_SET,
1016		.p_encode	= rpcb_enc_mapping,
1017		.p_decode	= rpcb_dec_set,
1018		.p_arglen	= RPCB_mappingargs_sz,
1019		.p_replen	= RPCB_setres_sz,
1020		.p_statidx	= RPCBPROC_SET,
1021		.p_timer	= 0,
1022		.p_name		= "SET",
1023	},
1024	[RPCBPROC_UNSET] = {
1025		.p_proc		= RPCBPROC_UNSET,
1026		.p_encode	= rpcb_enc_mapping,
1027		.p_decode	= rpcb_dec_set,
1028		.p_arglen	= RPCB_mappingargs_sz,
1029		.p_replen	= RPCB_setres_sz,
1030		.p_statidx	= RPCBPROC_UNSET,
1031		.p_timer	= 0,
1032		.p_name		= "UNSET",
1033	},
1034	[RPCBPROC_GETPORT] = {
1035		.p_proc		= RPCBPROC_GETPORT,
1036		.p_encode	= rpcb_enc_mapping,
1037		.p_decode	= rpcb_dec_getport,
1038		.p_arglen	= RPCB_mappingargs_sz,
1039		.p_replen	= RPCB_getportres_sz,
1040		.p_statidx	= RPCBPROC_GETPORT,
1041		.p_timer	= 0,
1042		.p_name		= "GETPORT",
1043	},
1044};
1045
1046static const struct rpc_procinfo rpcb_procedures3[] = {
1047	[RPCBPROC_SET] = {
1048		.p_proc		= RPCBPROC_SET,
1049		.p_encode	= rpcb_enc_getaddr,
1050		.p_decode	= rpcb_dec_set,
1051		.p_arglen	= RPCB_getaddrargs_sz,
1052		.p_replen	= RPCB_setres_sz,
1053		.p_statidx	= RPCBPROC_SET,
1054		.p_timer	= 0,
1055		.p_name		= "SET",
1056	},
1057	[RPCBPROC_UNSET] = {
1058		.p_proc		= RPCBPROC_UNSET,
1059		.p_encode	= rpcb_enc_getaddr,
1060		.p_decode	= rpcb_dec_set,
1061		.p_arglen	= RPCB_getaddrargs_sz,
1062		.p_replen	= RPCB_setres_sz,
1063		.p_statidx	= RPCBPROC_UNSET,
1064		.p_timer	= 0,
1065		.p_name		= "UNSET",
1066	},
1067	[RPCBPROC_GETADDR] = {
1068		.p_proc		= RPCBPROC_GETADDR,
1069		.p_encode	= rpcb_enc_getaddr,
1070		.p_decode	= rpcb_dec_getaddr,
1071		.p_arglen	= RPCB_getaddrargs_sz,
1072		.p_replen	= RPCB_getaddrres_sz,
1073		.p_statidx	= RPCBPROC_GETADDR,
1074		.p_timer	= 0,
1075		.p_name		= "GETADDR",
1076	},
1077};
1078
1079static const struct rpc_procinfo rpcb_procedures4[] = {
1080	[RPCBPROC_SET] = {
1081		.p_proc		= RPCBPROC_SET,
1082		.p_encode	= rpcb_enc_getaddr,
1083		.p_decode	= rpcb_dec_set,
1084		.p_arglen	= RPCB_getaddrargs_sz,
1085		.p_replen	= RPCB_setres_sz,
1086		.p_statidx	= RPCBPROC_SET,
1087		.p_timer	= 0,
1088		.p_name		= "SET",
1089	},
1090	[RPCBPROC_UNSET] = {
1091		.p_proc		= RPCBPROC_UNSET,
1092		.p_encode	= rpcb_enc_getaddr,
1093		.p_decode	= rpcb_dec_set,
1094		.p_arglen	= RPCB_getaddrargs_sz,
1095		.p_replen	= RPCB_setres_sz,
1096		.p_statidx	= RPCBPROC_UNSET,
1097		.p_timer	= 0,
1098		.p_name		= "UNSET",
1099	},
1100	[RPCBPROC_GETADDR] = {
1101		.p_proc		= RPCBPROC_GETADDR,
1102		.p_encode	= rpcb_enc_getaddr,
1103		.p_decode	= rpcb_dec_getaddr,
1104		.p_arglen	= RPCB_getaddrargs_sz,
1105		.p_replen	= RPCB_getaddrres_sz,
1106		.p_statidx	= RPCBPROC_GETADDR,
1107		.p_timer	= 0,
1108		.p_name		= "GETADDR",
1109	},
1110};
1111
1112static const struct rpcb_info rpcb_next_version[] = {
1113	{
1114		.rpc_vers	= RPCBVERS_2,
1115		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
1116	},
1117	{
1118		.rpc_proc	= NULL,
1119	},
1120};
1121
1122static const struct rpcb_info rpcb_next_version6[] = {
1123	{
1124		.rpc_vers	= RPCBVERS_4,
1125		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
1126	},
1127	{
1128		.rpc_vers	= RPCBVERS_3,
1129		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
1130	},
1131	{
1132		.rpc_proc	= NULL,
1133	},
1134};
1135
1136static unsigned int rpcb_version2_counts[ARRAY_SIZE(rpcb_procedures2)];
1137static const struct rpc_version rpcb_version2 = {
1138	.number		= RPCBVERS_2,
1139	.nrprocs	= ARRAY_SIZE(rpcb_procedures2),
1140	.procs		= rpcb_procedures2,
1141	.counts		= rpcb_version2_counts,
1142};
1143
1144static unsigned int rpcb_version3_counts[ARRAY_SIZE(rpcb_procedures3)];
1145static const struct rpc_version rpcb_version3 = {
1146	.number		= RPCBVERS_3,
1147	.nrprocs	= ARRAY_SIZE(rpcb_procedures3),
1148	.procs		= rpcb_procedures3,
1149	.counts		= rpcb_version3_counts,
1150};
1151
1152static unsigned int rpcb_version4_counts[ARRAY_SIZE(rpcb_procedures4)];
1153static const struct rpc_version rpcb_version4 = {
1154	.number		= RPCBVERS_4,
1155	.nrprocs	= ARRAY_SIZE(rpcb_procedures4),
1156	.procs		= rpcb_procedures4,
1157	.counts		= rpcb_version4_counts,
1158};
1159
1160static const struct rpc_version *rpcb_version[] = {
1161	NULL,
1162	NULL,
1163	&rpcb_version2,
1164	&rpcb_version3,
1165	&rpcb_version4
1166};
1167
1168static struct rpc_stat rpcb_stats;
1169
1170static const struct rpc_program rpcb_program = {
1171	.name		= "rpcbind",
1172	.number		= RPCBIND_PROGRAM,
1173	.nrvers		= ARRAY_SIZE(rpcb_version),
1174	.version	= rpcb_version,
1175	.stats		= &rpcb_stats,
1176};
v3.15
 
   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#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			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 *hostname,
 
 359				    struct sockaddr *srvaddr, size_t salen,
 360				    int proto, u32 version)
 
 361{
 362	struct rpc_create_args args = {
 363		.net		= net,
 364		.protocol	= proto,
 365		.address	= srvaddr,
 366		.addrsize	= salen,
 367		.servername	= hostname,
 
 368		.program	= &rpcb_program,
 369		.version	= version,
 370		.authflavor	= RPC_AUTH_UNIX,
 
 371		.flags		= (RPC_CLNT_CREATE_NOPING |
 372					RPC_CLNT_CREATE_NONPRIVPORT),
 373	};
 374
 375	switch (srvaddr->sa_family) {
 376	case AF_INET:
 377		((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
 378		break;
 379	case AF_INET6:
 380		((struct sockaddr_in6 *)srvaddr)->sin6_port = htons(RPCBIND_PORT);
 381		break;
 382	default:
 383		return ERR_PTR(-EAFNOSUPPORT);
 384	}
 385
 386	return rpc_create(&args);
 387}
 388
 389static int rpcb_register_call(struct sunrpc_net *sn, struct rpc_clnt *clnt, struct rpc_message *msg, bool is_set)
 390{
 391	int flags = RPC_TASK_NOCONNECT;
 392	int error, result = 0;
 393
 394	if (is_set || !sn->rpcb_is_af_local)
 395		flags = RPC_TASK_SOFTCONN;
 396	msg->rpc_resp = &result;
 397
 398	error = rpc_call_sync(clnt, msg, flags);
 399	if (error < 0) {
 400		dprintk("RPC:       failed to contact local rpcbind "
 401				"server (errno %d).\n", -error);
 402		return error;
 403	}
 404
 405	if (!result)
 406		return -EACCES;
 407	return 0;
 408}
 409
 410/**
 411 * rpcb_register - set or unset a port registration with the local rpcbind svc
 412 * @net: target network namespace
 413 * @prog: RPC program number to bind
 414 * @vers: RPC version number to bind
 415 * @prot: transport protocol to register
 416 * @port: port value to register
 417 *
 418 * Returns zero if the registration request was dispatched successfully
 419 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 420 * value that reflects the nature of the error (request could not be
 421 * dispatched, timed out, or rpcbind returned an error).
 422 *
 423 * RPC services invoke this function to advertise their contact
 424 * information via the system's rpcbind daemon.  RPC services
 425 * invoke this function once for each [program, version, transport]
 426 * tuple they wish to advertise.
 427 *
 428 * Callers may also unregister RPC services that are no longer
 429 * available by setting the passed-in port to zero.  This removes
 430 * all registered transports for [program, version] from the local
 431 * rpcbind database.
 432 *
 433 * This function uses rpcbind protocol version 2 to contact the
 434 * local rpcbind daemon.
 435 *
 436 * Registration works over both AF_INET and AF_INET6, and services
 437 * registered via this function are advertised as available for any
 438 * address.  If the local rpcbind daemon is listening on AF_INET6,
 439 * services registered via this function will be advertised on
 440 * IN6ADDR_ANY (ie available for all AF_INET and AF_INET6
 441 * addresses).
 442 */
 443int rpcb_register(struct net *net, u32 prog, u32 vers, int prot, unsigned short port)
 444{
 445	struct rpcbind_args map = {
 446		.r_prog		= prog,
 447		.r_vers		= vers,
 448		.r_prot		= prot,
 449		.r_port		= port,
 450	};
 451	struct rpc_message msg = {
 452		.rpc_argp	= &map,
 453	};
 454	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 455	bool is_set = false;
 456
 457	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
 458			"rpcbind\n", (port ? "" : "un"),
 459			prog, vers, prot, port);
 460
 461	msg.rpc_proc = &rpcb_procedures2[RPCBPROC_UNSET];
 462	if (port != 0) {
 463		msg.rpc_proc = &rpcb_procedures2[RPCBPROC_SET];
 464		is_set = true;
 465	}
 466
 467	return rpcb_register_call(sn, sn->rpcb_local_clnt, &msg, is_set);
 468}
 469
 470/*
 471 * Fill in AF_INET family-specific arguments to register
 472 */
 473static int rpcb_register_inet4(struct sunrpc_net *sn,
 474			       const struct sockaddr *sap,
 475			       struct rpc_message *msg)
 476{
 477	const struct sockaddr_in *sin = (const struct sockaddr_in *)sap;
 478	struct rpcbind_args *map = msg->rpc_argp;
 479	unsigned short port = ntohs(sin->sin_port);
 480	bool is_set = false;
 481	int result;
 482
 483	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 484
 485	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 486		"local rpcbind\n", (port ? "" : "un"),
 487			map->r_prog, map->r_vers,
 488			map->r_addr, map->r_netid);
 489
 490	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 491	if (port != 0) {
 492		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 493		is_set = true;
 494	}
 495
 496	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 497	kfree(map->r_addr);
 498	return result;
 499}
 500
 501/*
 502 * Fill in AF_INET6 family-specific arguments to register
 503 */
 504static int rpcb_register_inet6(struct sunrpc_net *sn,
 505			       const struct sockaddr *sap,
 506			       struct rpc_message *msg)
 507{
 508	const struct sockaddr_in6 *sin6 = (const struct sockaddr_in6 *)sap;
 509	struct rpcbind_args *map = msg->rpc_argp;
 510	unsigned short port = ntohs(sin6->sin6_port);
 511	bool is_set = false;
 512	int result;
 513
 514	map->r_addr = rpc_sockaddr2uaddr(sap, GFP_KERNEL);
 515
 516	dprintk("RPC:       %sregistering [%u, %u, %s, '%s'] with "
 517		"local rpcbind\n", (port ? "" : "un"),
 518			map->r_prog, map->r_vers,
 519			map->r_addr, map->r_netid);
 520
 521	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 522	if (port != 0) {
 523		msg->rpc_proc = &rpcb_procedures4[RPCBPROC_SET];
 524		is_set = true;
 525	}
 526
 527	result = rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, is_set);
 528	kfree(map->r_addr);
 529	return result;
 530}
 531
 532static int rpcb_unregister_all_protofamilies(struct sunrpc_net *sn,
 533					     struct rpc_message *msg)
 534{
 535	struct rpcbind_args *map = msg->rpc_argp;
 536
 537	dprintk("RPC:       unregistering [%u, %u, '%s'] with "
 538		"local rpcbind\n",
 539			map->r_prog, map->r_vers, map->r_netid);
 540
 541	map->r_addr = "";
 542	msg->rpc_proc = &rpcb_procedures4[RPCBPROC_UNSET];
 543
 544	return rpcb_register_call(sn, sn->rpcb_local_clnt4, msg, false);
 545}
 546
 547/**
 548 * rpcb_v4_register - set or unset a port registration with the local rpcbind
 549 * @net: target network namespace
 550 * @program: RPC program number of service to (un)register
 551 * @version: RPC version number of service to (un)register
 552 * @address: address family, IP address, and port to (un)register
 553 * @netid: netid of transport protocol to (un)register
 554 *
 555 * Returns zero if the registration request was dispatched successfully
 556 * and the rpcbind daemon returned success.  Otherwise, returns an errno
 557 * value that reflects the nature of the error (request could not be
 558 * dispatched, timed out, or rpcbind returned an error).
 559 *
 560 * RPC services invoke this function to advertise their contact
 561 * information via the system's rpcbind daemon.  RPC services
 562 * invoke this function once for each [program, version, address,
 563 * netid] tuple they wish to advertise.
 564 *
 565 * Callers may also unregister RPC services that are registered at a
 566 * specific address by setting the port number in @address to zero.
 567 * They may unregister all registered protocol families at once for
 568 * a service by passing a NULL @address argument.  If @netid is ""
 569 * then all netids for [program, version, address] are unregistered.
 570 *
 571 * This function uses rpcbind protocol version 4 to contact the
 572 * local rpcbind daemon.  The local rpcbind daemon must support
 573 * version 4 of the rpcbind protocol in order for these functions
 574 * to register a service successfully.
 575 *
 576 * Supported netids include "udp" and "tcp" for UDP and TCP over
 577 * IPv4, and "udp6" and "tcp6" for UDP and TCP over IPv6,
 578 * respectively.
 579 *
 580 * The contents of @address determine the address family and the
 581 * port to be registered.  The usual practice is to pass INADDR_ANY
 582 * as the raw address, but specifying a non-zero address is also
 583 * supported by this API if the caller wishes to advertise an RPC
 584 * service on a specific network interface.
 585 *
 586 * Note that passing in INADDR_ANY does not create the same service
 587 * registration as IN6ADDR_ANY.  The former advertises an RPC
 588 * service on any IPv4 address, but not on IPv6.  The latter
 589 * advertises the service on all IPv4 and IPv6 addresses.
 590 */
 591int rpcb_v4_register(struct net *net, const u32 program, const u32 version,
 592		     const struct sockaddr *address, const char *netid)
 593{
 594	struct rpcbind_args map = {
 595		.r_prog		= program,
 596		.r_vers		= version,
 597		.r_netid	= netid,
 598		.r_owner	= RPCB_OWNER_STRING,
 599	};
 600	struct rpc_message msg = {
 601		.rpc_argp	= &map,
 602	};
 603	struct sunrpc_net *sn = net_generic(net, sunrpc_net_id);
 604
 605	if (sn->rpcb_local_clnt4 == NULL)
 606		return -EPROTONOSUPPORT;
 607
 608	if (address == NULL)
 609		return rpcb_unregister_all_protofamilies(sn, &msg);
 610
 611	switch (address->sa_family) {
 612	case AF_INET:
 613		return rpcb_register_inet4(sn, address, &msg);
 614	case AF_INET6:
 615		return rpcb_register_inet6(sn, address, &msg);
 616	}
 617
 618	return -EAFNOSUPPORT;
 619}
 620
 621static struct rpc_task *rpcb_call_async(struct rpc_clnt *rpcb_clnt, struct rpcbind_args *map, struct rpc_procinfo *proc)
 
 622{
 623	struct rpc_message msg = {
 624		.rpc_proc = proc,
 625		.rpc_argp = map,
 626		.rpc_resp = map,
 627	};
 628	struct rpc_task_setup task_setup_data = {
 629		.rpc_client = rpcb_clnt,
 630		.rpc_message = &msg,
 631		.callback_ops = &rpcb_getport_ops,
 632		.callback_data = map,
 633		.flags = RPC_TASK_ASYNC | RPC_TASK_SOFTCONN,
 634	};
 635
 636	return rpc_run_task(&task_setup_data);
 637}
 638
 639/*
 640 * In the case where rpc clients have been cloned, we want to make
 641 * sure that we use the program number/version etc of the actual
 642 * owner of the xprt. To do so, we walk back up the tree of parents
 643 * to find whoever created the transport and/or whoever has the
 644 * autobind flag set.
 645 */
 646static struct rpc_clnt *rpcb_find_transport_owner(struct rpc_clnt *clnt)
 647{
 648	struct rpc_clnt *parent = clnt->cl_parent;
 649	struct rpc_xprt *xprt = rcu_dereference(clnt->cl_xprt);
 650
 651	while (parent != clnt) {
 652		if (rcu_dereference(parent->cl_xprt) != xprt)
 653			break;
 654		if (clnt->cl_autobind)
 655			break;
 656		clnt = parent;
 657		parent = parent->cl_parent;
 658	}
 659	return clnt;
 660}
 661
 662/**
 663 * rpcb_getport_async - obtain the port for a given RPC service on a given host
 664 * @task: task that is waiting for portmapper request
 665 *
 666 * This one can be called for an ongoing RPC request, and can be used in
 667 * an async (rpciod) context.
 668 */
 669void rpcb_getport_async(struct rpc_task *task)
 670{
 671	struct rpc_clnt *clnt;
 672	struct rpc_procinfo *proc;
 673	u32 bind_version;
 674	struct rpc_xprt *xprt;
 675	struct rpc_clnt	*rpcb_clnt;
 676	struct rpcbind_args *map;
 677	struct rpc_task	*child;
 678	struct sockaddr_storage addr;
 679	struct sockaddr *sap = (struct sockaddr *)&addr;
 680	size_t salen;
 681	int status;
 682
 683	rcu_read_lock();
 684	do {
 685		clnt = rpcb_find_transport_owner(task->tk_client);
 686		xprt = xprt_get(rcu_dereference(clnt->cl_xprt));
 687	} while (xprt == NULL);
 688	rcu_read_unlock();
 
 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, xprt->servername, sap, salen,
 744				xprt->prot, bind_version);
 
 
 
 745	if (IS_ERR(rpcb_clnt)) {
 746		status = PTR_ERR(rpcb_clnt);
 747		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
 748			task->tk_pid, __func__, PTR_ERR(rpcb_clnt));
 749		goto bailout_nofree;
 750	}
 751
 752	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
 753	if (!map) {
 754		status = -ENOMEM;
 755		dprintk("RPC: %5u %s: no memory available\n",
 756			task->tk_pid, __func__);
 757		goto bailout_release_client;
 758	}
 759	map->r_prog = clnt->cl_prog;
 760	map->r_vers = clnt->cl_vers;
 761	map->r_prot = xprt->prot;
 762	map->r_port = 0;
 763	map->r_xprt = xprt;
 764	map->r_status = -EIO;
 765
 766	switch (bind_version) {
 767	case RPCBVERS_4:
 768	case RPCBVERS_3:
 769		map->r_netid = xprt->address_strings[RPC_DISPLAY_NETID];
 770		map->r_addr = rpc_sockaddr2uaddr(sap, GFP_ATOMIC);
 
 
 
 
 
 
 771		map->r_owner = "";
 772		break;
 773	case RPCBVERS_2:
 774		map->r_addr = NULL;
 775		break;
 776	default:
 777		BUG();
 778	}
 779
 780	child = rpcb_call_async(rpcb_clnt, map, proc);
 781	rpc_release_client(rpcb_clnt);
 782	if (IS_ERR(child)) {
 783		/* rpcb_map_release() has freed the arguments */
 784		dprintk("RPC: %5u %s: rpc_run_task failed\n",
 785			task->tk_pid, __func__);
 786		return;
 787	}
 788
 789	xprt->stat.bind_count++;
 790	rpc_put_task(child);
 791	return;
 792
 
 
 793bailout_release_client:
 794	rpc_release_client(rpcb_clnt);
 795bailout_nofree:
 796	rpcb_wake_rpcbind_waiters(xprt, status);
 797	task->tk_status = status;
 798	xprt_put(xprt);
 799}
 800EXPORT_SYMBOL_GPL(rpcb_getport_async);
 801
 802/*
 803 * Rpcbind child task calls this callback via tk_exit.
 804 */
 805static void rpcb_getport_done(struct rpc_task *child, void *data)
 806{
 807	struct rpcbind_args *map = data;
 808	struct rpc_xprt *xprt = map->r_xprt;
 809	int status = child->tk_status;
 810
 811	/* Garbage reply: retry with a lesser rpcbind version */
 812	if (status == -EIO)
 813		status = -EPROTONOSUPPORT;
 814
 815	/* rpcbind server doesn't support this rpcbind protocol version */
 816	if (status == -EPROTONOSUPPORT)
 817		xprt->bind_index++;
 818
 819	if (status < 0) {
 820		/* rpcbind server not available on remote host? */
 821		xprt->ops->set_port(xprt, 0);
 822	} else if (map->r_port == 0) {
 823		/* Requested RPC service wasn't registered on remote host */
 824		xprt->ops->set_port(xprt, 0);
 825		status = -EACCES;
 826	} else {
 827		/* Succeeded */
 828		xprt->ops->set_port(xprt, map->r_port);
 829		xprt_set_bound(xprt);
 830		status = 0;
 831	}
 832
 833	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
 834			child->tk_pid, status, map->r_port);
 835
 836	map->r_status = status;
 837}
 838
 839/*
 840 * XDR functions for rpcbind
 841 */
 842
 843static void rpcb_enc_mapping(struct rpc_rqst *req, struct xdr_stream *xdr,
 844			     const struct rpcbind_args *rpcb)
 845{
 
 846	__be32 *p;
 847
 848	dprintk("RPC: %5u encoding PMAP_%s call (%u, %u, %d, %u)\n",
 849			req->rq_task->tk_pid,
 850			req->rq_task->tk_msg.rpc_proc->p_name,
 851			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
 852
 853	p = xdr_reserve_space(xdr, RPCB_mappingargs_sz << 2);
 854	*p++ = cpu_to_be32(rpcb->r_prog);
 855	*p++ = cpu_to_be32(rpcb->r_vers);
 856	*p++ = cpu_to_be32(rpcb->r_prot);
 857	*p   = cpu_to_be32(rpcb->r_port);
 858}
 859
 860static int rpcb_dec_getport(struct rpc_rqst *req, struct xdr_stream *xdr,
 861			    struct rpcbind_args *rpcb)
 862{
 
 863	unsigned long port;
 864	__be32 *p;
 865
 866	rpcb->r_port = 0;
 867
 868	p = xdr_inline_decode(xdr, 4);
 869	if (unlikely(p == NULL))
 870		return -EIO;
 871
 872	port = be32_to_cpup(p);
 873	dprintk("RPC: %5u PMAP_%s result: %lu\n", req->rq_task->tk_pid,
 874			req->rq_task->tk_msg.rpc_proc->p_name, port);
 875	if (unlikely(port > USHRT_MAX))
 876		return -EIO;
 877
 878	rpcb->r_port = port;
 879	return 0;
 880}
 881
 882static int rpcb_dec_set(struct rpc_rqst *req, struct xdr_stream *xdr,
 883			unsigned int *boolp)
 884{
 
 885	__be32 *p;
 886
 887	p = xdr_inline_decode(xdr, 4);
 888	if (unlikely(p == NULL))
 889		return -EIO;
 890
 891	*boolp = 0;
 892	if (*p != xdr_zero)
 893		*boolp = 1;
 894
 895	dprintk("RPC: %5u RPCB_%s call %s\n",
 896			req->rq_task->tk_pid,
 897			req->rq_task->tk_msg.rpc_proc->p_name,
 898			(*boolp ? "succeeded" : "failed"));
 899	return 0;
 900}
 901
 902static void encode_rpcb_string(struct xdr_stream *xdr, const char *string,
 903			       const u32 maxstrlen)
 904{
 905	__be32 *p;
 906	u32 len;
 907
 908	len = strlen(string);
 909	WARN_ON_ONCE(len > maxstrlen);
 910	if (len > maxstrlen)
 911		/* truncate and hope for the best */
 912		len = maxstrlen;
 913	p = xdr_reserve_space(xdr, 4 + len);
 914	xdr_encode_opaque(p, string, len);
 915}
 916
 917static void rpcb_enc_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 918			     const struct rpcbind_args *rpcb)
 919{
 
 920	__be32 *p;
 921
 922	dprintk("RPC: %5u encoding RPCB_%s call (%u, %u, '%s', '%s')\n",
 923			req->rq_task->tk_pid,
 924			req->rq_task->tk_msg.rpc_proc->p_name,
 925			rpcb->r_prog, rpcb->r_vers,
 926			rpcb->r_netid, rpcb->r_addr);
 927
 928	p = xdr_reserve_space(xdr, (RPCB_program_sz + RPCB_version_sz) << 2);
 929	*p++ = cpu_to_be32(rpcb->r_prog);
 930	*p = cpu_to_be32(rpcb->r_vers);
 931
 932	encode_rpcb_string(xdr, rpcb->r_netid, RPCBIND_MAXNETIDLEN);
 933	encode_rpcb_string(xdr, rpcb->r_addr, RPCBIND_MAXUADDRLEN);
 934	encode_rpcb_string(xdr, rpcb->r_owner, RPCB_MAXOWNERLEN);
 935}
 936
 937static int rpcb_dec_getaddr(struct rpc_rqst *req, struct xdr_stream *xdr,
 938			    struct rpcbind_args *rpcb)
 939{
 
 940	struct sockaddr_storage address;
 941	struct sockaddr *sap = (struct sockaddr *)&address;
 942	__be32 *p;
 943	u32 len;
 944
 945	rpcb->r_port = 0;
 946
 947	p = xdr_inline_decode(xdr, 4);
 948	if (unlikely(p == NULL))
 949		goto out_fail;
 950	len = be32_to_cpup(p);
 951
 952	/*
 953	 * If the returned universal address is a null string,
 954	 * the requested RPC service was not registered.
 955	 */
 956	if (len == 0) {
 957		dprintk("RPC: %5u RPCB reply: program not registered\n",
 958				req->rq_task->tk_pid);
 959		return 0;
 960	}
 961
 962	if (unlikely(len > RPCBIND_MAXUADDRLEN))
 963		goto out_fail;
 964
 965	p = xdr_inline_decode(xdr, len);
 966	if (unlikely(p == NULL))
 967		goto out_fail;
 968	dprintk("RPC: %5u RPCB_%s reply: %s\n", req->rq_task->tk_pid,
 969			req->rq_task->tk_msg.rpc_proc->p_name, (char *)p);
 970
 971	if (rpc_uaddr2sockaddr(req->rq_xprt->xprt_net, (char *)p, len,
 972				sap, sizeof(address)) == 0)
 973		goto out_fail;
 974	rpcb->r_port = rpc_get_port(sap);
 975
 976	return 0;
 977
 978out_fail:
 979	dprintk("RPC: %5u malformed RPCB_%s reply\n",
 980			req->rq_task->tk_pid,
 981			req->rq_task->tk_msg.rpc_proc->p_name);
 982	return -EIO;
 983}
 984
 985/*
 986 * Not all rpcbind procedures described in RFC 1833 are implemented
 987 * since the Linux kernel RPC code requires only these.
 988 */
 989
 990static struct rpc_procinfo rpcb_procedures2[] = {
 991	[RPCBPROC_SET] = {
 992		.p_proc		= RPCBPROC_SET,
 993		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
 994		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
 995		.p_arglen	= RPCB_mappingargs_sz,
 996		.p_replen	= RPCB_setres_sz,
 997		.p_statidx	= RPCBPROC_SET,
 998		.p_timer	= 0,
 999		.p_name		= "SET",
1000	},
1001	[RPCBPROC_UNSET] = {
1002		.p_proc		= RPCBPROC_UNSET,
1003		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
1004		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1005		.p_arglen	= RPCB_mappingargs_sz,
1006		.p_replen	= RPCB_setres_sz,
1007		.p_statidx	= RPCBPROC_UNSET,
1008		.p_timer	= 0,
1009		.p_name		= "UNSET",
1010	},
1011	[RPCBPROC_GETPORT] = {
1012		.p_proc		= RPCBPROC_GETPORT,
1013		.p_encode	= (kxdreproc_t)rpcb_enc_mapping,
1014		.p_decode	= (kxdrdproc_t)rpcb_dec_getport,
1015		.p_arglen	= RPCB_mappingargs_sz,
1016		.p_replen	= RPCB_getportres_sz,
1017		.p_statidx	= RPCBPROC_GETPORT,
1018		.p_timer	= 0,
1019		.p_name		= "GETPORT",
1020	},
1021};
1022
1023static struct rpc_procinfo rpcb_procedures3[] = {
1024	[RPCBPROC_SET] = {
1025		.p_proc		= RPCBPROC_SET,
1026		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1027		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1028		.p_arglen	= RPCB_getaddrargs_sz,
1029		.p_replen	= RPCB_setres_sz,
1030		.p_statidx	= RPCBPROC_SET,
1031		.p_timer	= 0,
1032		.p_name		= "SET",
1033	},
1034	[RPCBPROC_UNSET] = {
1035		.p_proc		= RPCBPROC_UNSET,
1036		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1037		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1038		.p_arglen	= RPCB_getaddrargs_sz,
1039		.p_replen	= RPCB_setres_sz,
1040		.p_statidx	= RPCBPROC_UNSET,
1041		.p_timer	= 0,
1042		.p_name		= "UNSET",
1043	},
1044	[RPCBPROC_GETADDR] = {
1045		.p_proc		= RPCBPROC_GETADDR,
1046		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1047		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1048		.p_arglen	= RPCB_getaddrargs_sz,
1049		.p_replen	= RPCB_getaddrres_sz,
1050		.p_statidx	= RPCBPROC_GETADDR,
1051		.p_timer	= 0,
1052		.p_name		= "GETADDR",
1053	},
1054};
1055
1056static struct rpc_procinfo rpcb_procedures4[] = {
1057	[RPCBPROC_SET] = {
1058		.p_proc		= RPCBPROC_SET,
1059		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1060		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1061		.p_arglen	= RPCB_getaddrargs_sz,
1062		.p_replen	= RPCB_setres_sz,
1063		.p_statidx	= RPCBPROC_SET,
1064		.p_timer	= 0,
1065		.p_name		= "SET",
1066	},
1067	[RPCBPROC_UNSET] = {
1068		.p_proc		= RPCBPROC_UNSET,
1069		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1070		.p_decode	= (kxdrdproc_t)rpcb_dec_set,
1071		.p_arglen	= RPCB_getaddrargs_sz,
1072		.p_replen	= RPCB_setres_sz,
1073		.p_statidx	= RPCBPROC_UNSET,
1074		.p_timer	= 0,
1075		.p_name		= "UNSET",
1076	},
1077	[RPCBPROC_GETADDR] = {
1078		.p_proc		= RPCBPROC_GETADDR,
1079		.p_encode	= (kxdreproc_t)rpcb_enc_getaddr,
1080		.p_decode	= (kxdrdproc_t)rpcb_dec_getaddr,
1081		.p_arglen	= RPCB_getaddrargs_sz,
1082		.p_replen	= RPCB_getaddrres_sz,
1083		.p_statidx	= RPCBPROC_GETADDR,
1084		.p_timer	= 0,
1085		.p_name		= "GETADDR",
1086	},
1087};
1088
1089static const struct rpcb_info rpcb_next_version[] = {
1090	{
1091		.rpc_vers	= RPCBVERS_2,
1092		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
1093	},
1094	{
1095		.rpc_proc	= NULL,
1096	},
1097};
1098
1099static const struct rpcb_info rpcb_next_version6[] = {
1100	{
1101		.rpc_vers	= RPCBVERS_4,
1102		.rpc_proc	= &rpcb_procedures4[RPCBPROC_GETADDR],
1103	},
1104	{
1105		.rpc_vers	= RPCBVERS_3,
1106		.rpc_proc	= &rpcb_procedures3[RPCBPROC_GETADDR],
1107	},
1108	{
1109		.rpc_proc	= NULL,
1110	},
1111};
1112
 
1113static const struct rpc_version rpcb_version2 = {
1114	.number		= RPCBVERS_2,
1115	.nrprocs	= ARRAY_SIZE(rpcb_procedures2),
1116	.procs		= rpcb_procedures2
 
1117};
1118
 
1119static const struct rpc_version rpcb_version3 = {
1120	.number		= RPCBVERS_3,
1121	.nrprocs	= ARRAY_SIZE(rpcb_procedures3),
1122	.procs		= rpcb_procedures3
 
1123};
1124
 
1125static const struct rpc_version rpcb_version4 = {
1126	.number		= RPCBVERS_4,
1127	.nrprocs	= ARRAY_SIZE(rpcb_procedures4),
1128	.procs		= rpcb_procedures4
 
1129};
1130
1131static const struct rpc_version *rpcb_version[] = {
1132	NULL,
1133	NULL,
1134	&rpcb_version2,
1135	&rpcb_version3,
1136	&rpcb_version4
1137};
1138
1139static struct rpc_stat rpcb_stats;
1140
1141static const struct rpc_program rpcb_program = {
1142	.name		= "rpcbind",
1143	.number		= RPCBIND_PROGRAM,
1144	.nrvers		= ARRAY_SIZE(rpcb_version),
1145	.version	= rpcb_version,
1146	.stats		= &rpcb_stats,
1147};