path: root/net/sunrpc/rpcb_clnt.c

/*
 * In-kernel rpcbind client supporting versions 2, 3, and 4 of the rpcbind
 * protocol
 *
 * Based on RFC 1833: "Binding Protocols for ONC RPC Version 2" and
 * RFC 3530: "Network File System (NFS) version 4 Protocol"
 *
 * Original: Gilles Quillard, Bull Open Source, 2005 <gilles.quillard@bull.net>
 * Updated: Chuck Lever, Oracle Corporation, 2007 <chuck.lever@oracle.com>
 *
 * Descended from net/sunrpc/pmap_clnt.c,
 *  Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/module.h>

#include <linux/types.h>
#include <linux/socket.h>
#include <linux/in.h>
#include <linux/in6.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <net/ipv6.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/sched.h>
#include <linux/sunrpc/xprtsock.h>

#ifdef RPC_DEBUG
# define RPCDBG_FACILITY	RPCDBG_BIND
#endif

#define RPCBIND_PROGRAM		(100000u)
#define RPCBIND_PORT		(111u)

#define RPCBVERS_2		(2u)
#define RPCBVERS_3		(3u)
#define RPCBVERS_4		(4u)

enum {
	RPCBPROC_NULL,
	RPCBPROC_SET,
	RPCBPROC_UNSET,
	RPCBPROC_GETPORT,
	RPCBPROC_GETADDR = 3,		/* alias for GETPORT */
	RPCBPROC_DUMP,
	RPCBPROC_CALLIT,
	RPCBPROC_BCAST = 5,		/* alias for CALLIT */
	RPCBPROC_GETTIME,
	RPCBPROC_UADDR2TADDR,
	RPCBPROC_TADDR2UADDR,
	RPCBPROC_GETVERSADDR,
	RPCBPROC_INDIRECT,
	RPCBPROC_GETADDRLIST,
	RPCBPROC_GETSTAT,
};

#define RPCB_HIGHPROC_2		RPCBPROC_CALLIT
#define RPCB_HIGHPROC_3		RPCBPROC_TADDR2UADDR
#define RPCB_HIGHPROC_4		RPCBPROC_GETSTAT

/*
 * r_owner
 *
 * The "owner" is allowed to unset a service in the rpcbind database.
 *
 * For AF_LOCAL SET/UNSET requests, rpcbind treats this string as a
 * UID which it maps to a local user name via a password lookup.
 * In all other cases it is ignored.
 *
 * For SET/UNSET requests, user space provides a value, even for
 * network requests, and GETADDR uses an empty string.  We follow
 * those precedents here.
 */
#define RPCB_OWNER_STRING	"0"
#define RPCB_MAXOWNERLEN	sizeof(RPCB_OWNER_STRING)

/*
 * XDR data type sizes
 */
#define RPCB_program_sz		(1)
#define RPCB_version_sz		(1)
#define RPCB_protocol_sz	(1)
#define RPCB_port_sz		(1)
#define RPCB_boolean_sz		(1)

#define RPCB_netid_sz		(1 + XDR_QUADLEN(RPCBIND_MAXNETIDLEN))
#define RPCB_addr_sz		(1 + XDR_QUADLEN(RPCBIND_MAXUADDRLEN))
#define RPCB_ownerstring_sz	(1 + XDR_QUADLEN(RPCB_MAXOWNERLEN))

/*
 * XDR argument and result sizes
 */
#define RPCB_mappingargs_sz	(RPCB_program_sz + RPCB_version_sz + \
				RPCB_protocol_sz + RPCB_port_sz)
#define RPCB_getaddrargs_sz	(RPCB_program_sz + RPCB_version_sz + \
				RPCB_netid_sz + RPCB_addr_sz + \
				RPCB_ownerstring_sz)

#define RPCB_getportres_sz	RPCB_port_sz
#define RPCB_setres_sz		RPCB_boolean_sz

/*
 * Note that RFC 1833 does not put any size restrictions on the
 * address string returned by the remote rpcbind database.
 */
#define RPCB_getaddrres_sz	RPCB_addr_sz

static void			rpcb_getport_done(struct rpc_task *, void *);
static void			rpcb_map_release(void *data);
static struct rpc_program	rpcb_program;

static struct rpc_clnt *	rpcb_local_clnt;
static struct rpc_clnt *	rpcb_local_clnt4;

struct rpcbind_args {
	struct rpc_xprt *	r_xprt;

	u32			r_prog;
	u32			r_vers;
	u32			r_prot;
	unsigned short		r_port;
	const char *		r_netid;
	const char *		r_addr;
	const char *		r_owner;

	int			r_status;
};

static struct rpc_procinfo rpcb_procedures2[];
static struct rpc_procinfo rpcb_procedures3[];
static struct rpc_procinfo rpcb_procedures4[];

struct rpcb_info {
	u32			rpc_vers;
	struct rpc_procinfo *	rpc_proc;
};

static struct rpcb_info rpcb_next_version[];
static struct rpcb_info rpcb_next_version6[];

static const struct rpc_call_ops rpcb_getport_ops = {
	.rpc_call_done		= rpcb_getport_done,
	.rpc_release		= rpcb_map_release,
};

static void rpcb_wake_rpcbind_waiters(struct rpc_xprt *xprt, int status)
{
	xprt_clear_binding(xprt);
	rpc_wake_up_status(&xprt->binding, status);
}

static void rpcb_map_release(void *data)
{
	struct rpcbind_args *map = data;

	rpcb_wake_rpcbind_waiters(map->r_xprt, map->r_status);
	xprt_put(map->r_xprt);
	kfree(map->r_addr);
	kfree(map);
}

static const struct sockaddr_in rpcb_inaddr_loopback = {
	.sin_family		= AF_INET,
	.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
	.sin_port		= htons(RPCBIND_PORT),
};

static DEFINE_MUTEX(rpcb_create_local_mutex);

/*
 * Returns zero on success, otherwise a negative errno value
 * is returned.
 */
static int rpcb_create_local(void)
{
	struct rpc_create_args args = {
		.protocol	= XPRT_TRANSPORT_TCP,
		.address	= (struct sockaddr *)&rpcb_inaddr_loopback,
		.addrsize	= sizeof(rpcb_inaddr_loopback),
		.servername	= "localhost",
		.program	= &rpcb_program,
		.version	= RPCBVERS_2,
		.authflavor	= RPC_AUTH_UNIX,
		.flags		= RPC_CLNT_CREATE_NOPING,
	};
	struct rpc_clnt *clnt, *clnt4;
	int result = 0;