text: /*
   * 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/kernel.h>
  #include <linux/errno.h>
  
  #include <linux/sunrpc/clnt.h>
  #include <linux/sunrpc/sched.h>
  
  #ifdef RPC_DEBUG
  # define RPCDBG_FACILITY	RPCDBG_BIND
  #endif
  
  #define RPCBIND_PROGRAM		(100000u)
  #define RPCBIND_PORT		(111u)
  
  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_addr
   *
   * Quoting RFC 3530, section 2.2:
   *
   * For TCP over IPv4 and for UDP over IPv4, the format of r_addr is the
   * US-ASCII string:
   *
   *	h1.h2.h3.h4.p1.p2
   *
   * The prefix, "h1.h2.h3.h4", is the standard textual form for
   * representing an IPv4 address, which is always four octets long.
   * Assuming big-endian ordering, h1, h2, h3, and h4, are respectively,
   * the first through fourth octets each converted to ASCII-decimal.
   * Assuming big-endian ordering, p1 and p2 are, respectively, the first
   * and second octets each converted to ASCII-decimal.  For example, if a
   * host, in big-endian order, has an address of 0x0A010307 and there is
   * a service listening on, in big endian order, port 0x020F (decimal
   * 527), then the complete universal address is "10.1.3.7.2.15".
   *
   * ...
   *
   * For TCP over IPv6 and for UDP over IPv6, the format of r_addr is the
   * US-ASCII string:
   *
   *	x1:x2:x3:x4:x5:x6:x7:x8.p1.p2
   *
   * The suffix "p1.p2" is the service port, and is computed the same way
   * as with universal addresses for TCP and UDP over IPv4.  The prefix,
   * "x1:x2:x3:x4:x5:x6:x7:x8", is the standard textual form for
   * representing an IPv6 address as defined in Section 2.2 of [RFC2373].
   * Additionally, the two alternative forms specified in Section 2.2 of
   * [RFC2373] are also acceptable.
   *
   * XXX: Currently this implementation does not explicitly convert the
   *      stored address to US-ASCII on non-ASCII systems.
   */
  #define RPCB_MAXADDRLEN		(128u)
  
  /*
   * r_netid
   *
   * Quoting RFC 3530, section 2.2:
   *
   * For TCP over IPv4 the value of r_netid is the string "tcp".  For UDP
   * over IPv4 the value of r_netid is the string "udp".
   *
   * ...
   *
   * For TCP over IPv6 the value of r_netid is the string "tcp6".  For UDP
   * over IPv6 the value of r_netid is the string "udp6".
   */
  #define RPCB_NETID_UDP	"\165\144\160"		/* "udp" */
  #define RPCB_NETID_TCP	"\164\143\160"		/* "tcp" */
  #define RPCB_NETID_UDP6	"\165\144\160\066"	/* "udp6" */
  #define RPCB_NETID_TCP6	"\164\143\160\066"	/* "tcp6" */
  
  #define RPCB_MAXNETIDLEN	(4u)
  
  /*
   * r_owner
   *
   * The "owner" is allowed to unset a service in the rpcbind database.
   * We always use the following (arbitrary) fixed string.
   */
  #define RPCB_OWNER_STRING	"rpcb"
  #define RPCB_MAXOWNERLEN	sizeof(RPCB_OWNER_STRING)
  
  static void			rpcb_getport_done(struct rpc_task *, void *);
  extern struct rpc_program	rpcb_program;
  
  struct rpcbind_args {
  	struct rpc_xprt *	r_xprt;
  
  	u32			r_prog;
  	u32			r_vers;
  	u32			r_prot;
  	unsigned short		r_port;
  	char *			r_netid;
  	char			r_addr[RPCB_MAXADDRLEN];
  	char *			r_owner;
  };
  
  static struct rpc_procinfo rpcb_procedures2[];
  static struct rpc_procinfo rpcb_procedures3[];
  
  static struct rpcb_info {
  	int			rpc_vers;
  	struct rpc_procinfo *	rpc_proc;
  } rpcb_next_version[];
  
  static void rpcb_getport_prepare(struct rpc_task *task, void *calldata)
  {
  	struct rpcbind_args *map = calldata;
  	struct rpc_xprt *xprt = map->r_xprt;
  	struct rpc_message msg = {
  		.rpc_proc	= rpcb_next_version[xprt->bind_index].rpc_proc,
  		.rpc_argp	= map,
  		.rpc_resp	= &map->r_port,
  	};
  
  	rpc_call_setup(task, &msg, 0);
  }
  
  static void rpcb_map_release(void *data)
  {
  	struct rpcbind_args *map = data;
  
  	xprt_put(map->r_xprt);
  	kfree(map);
  }
  
  static const struct rpc_call_ops rpcb_getport_ops = {
  	.rpc_call_prepare	= rpcb_getport_prepare,
  	.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 struct rpc_clnt *rpcb_create(char *hostname, struct sockaddr *srvaddr,
  					int proto, int version, int privileged)
  {
  	struct rpc_create_args args = {
  		.protocol	= proto,
  		.address	= srvaddr,
  		.addrsize	= sizeof(struct sockaddr_in),
  		.servername	= hostname,
  		.program	= &rpcb_program,
  		.version	= version,
  		.authflavor	= RPC_AUTH_UNIX,
  		.flags		= (RPC_CLNT_CREATE_NOPING |
  				   RPC_CLNT_CREATE_INTR),
  	};
  
  	((struct sockaddr_in *)srvaddr)->sin_port = htons(RPCBIND_PORT);
  	if (!privileged)
  		args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
  	return rpc_create(&args);
  }
  
  /**
   * rpcb_register - set or unset a port registration with the local rpcbind svc
   * @prog: RPC program number to bind
   * @vers: RPC version number to bind
   * @prot: transport protocol to use to make this request
   * @port: port value to register
   * @okay: result code
   *
   * port == 0 means unregister, port != 0 means register.
   *
   * This routine supports only rpcbind version 2.
   */
  int rpcb_register(u32 prog, u32 vers, int prot, unsigned short port, int *okay)
  {
  	struct sockaddr_in sin = {
  		.sin_family		= AF_INET,
  		.sin_addr.s_addr	= htonl(INADDR_LOOPBACK),
  	};
  	struct rpcbind_args map = {
  		.r_prog		= prog,
  		.r_vers		= vers,
  		.r_prot		= prot,
  		.r_port		= port,
  	};
  	struct rpc_message msg = {
  		.rpc_proc	= &rpcb_procedures2[port ?
  					RPCBPROC_SET : RPCBPROC_UNSET],
  		.rpc_argp	= &map,
  		.rpc_resp	= okay,
  	};
  	struct rpc_clnt *rpcb_clnt;
  	int error = 0;
  
  	dprintk("RPC:       %sregistering (%u, %u, %d, %u) with local "
  			"rpcbind\n", (port ? "" : "un"),
  			prog, vers, prot, port);
  
  	rpcb_clnt = rpcb_create("localhost", (struct sockaddr *) &sin,
  					IPPROTO_UDP, 2, 1);
  	if (IS_ERR(rpcb_clnt))
  		return PTR_ERR(rpcb_clnt);
  
  	error = rpc_call_sync(rpcb_clnt, &msg, 0);
  
  	rpc_shutdown_client(rpcb_clnt);
  	if (error < 0)
  		printk(KERN_WARNING "RPC: failed to contact local rpcbind "
  				"server (errno %d).\n", -error);
  	dprintk("RPC:       registration status %d/%d\n", error, *okay);
  
  	return error;
  }
  
  /**
   * rpcb_getport_sync - obtain the port for an RPC service on a given host
   * @sin: address of remote peer
   * @prog: RPC program number to bind
   * @vers: RPC version number to bind
   * @prot: transport protocol to use to make this request
   *
   * Called from outside the RPC client in a synchronous task context.
   * Uses default timeout parameters specified by underlying transport.
   *
   * XXX: Needs to support IPv6, and rpcbind versions 3 and 4
   */
  int rpcb_getport_sync(struct sockaddr_in *sin, __u32 prog,
  		      __u32 vers, int prot)
  {
  	struct rpcbind_args map = {
  		.r_prog		= prog,
  		.r_vers		= vers,
  		.r_prot		= prot,
  		.r_port		= 0,
  	};
  	struct rpc_message msg = {
  		.rpc_proc	= &rpcb_procedures2[RPCBPROC_GETPORT],
  		.rpc_argp	= &map,
  		.rpc_resp	= &map.r_port,
  	};
  	struct rpc_clnt	*rpcb_clnt;
  	char hostname[40];
  	int status;
  
  	dprintk("RPC:       %s(" NIPQUAD_FMT ", %u, %u, %d)\n",
  		__FUNCTION__, NIPQUAD(sin->sin_addr.s_addr), prog, vers, prot);
  
  	sprintf(hostname, NIPQUAD_FMT, NIPQUAD(sin->sin_addr.s_addr));
  	rpcb_clnt = rpcb_create(hostname, (struct sockaddr *)sin, prot, 2, 0);
  	if (IS_ERR(rpcb_clnt))
  		return PTR_ERR(rpcb_clnt);
  
  	status = rpc_call_sync(rpcb_clnt, &msg, 0);
  	rpc_shutdown_client(rpcb_clnt);
  
  	if (status >= 0) {
  		if (map.r_port != 0)
  			return map.r_port;
  		status = -EACCES;
  	}
  	return status;
  }
  EXPORT_SYMBOL_GPL(rpcb_getport_sync);
  
  /**
   * rpcb_getport_async - obtain the port for a given RPC service on a given host
   * @task: task that is waiting for portmapper request
   *
   * This one can be called for an ongoing RPC request, and can be used in
   * an async (rpciod) context.
   */
  void rpcb_getport_async(struct rpc_task *task)
  {
  	struct rpc_clnt *clnt = task->tk_client;
  	int bind_version;
  	struct rpc_xprt *xprt = task->tk_xprt;
  	struct rpc_clnt	*rpcb_clnt;
  	static struct rpcbind_args *map;
  	struct rpc_task	*child;
  	struct sockaddr addr;
  	int status;
  
  	dprintk("RPC: %5u %s(%s, %u, %u, %d)\n",
  		task->tk_pid, __FUNCTION__,
  		clnt->cl_server, clnt->cl_prog, clnt->cl_vers, xprt->prot);
  
  	/* Autobind on cloned rpc clients is discouraged */
  	BUG_ON(clnt->cl_parent != clnt);
  
  	if (xprt_test_and_set_binding(xprt)) {
  		status = -EACCES;		/* tell caller to check again */
  		dprintk("RPC: %5u %s: waiting for another binder\n",
  			task->tk_pid, __FUNCTION__);
  		goto bailout_nowake;
  	}
  
  	/* Put self on queue before sending rpcbind request, in case
  	 * rpcb_getport_done completes before we return from rpc_run_task */
  	rpc_sleep_on(&xprt->binding, task, NULL, NULL);
  
  	/* Someone else may have bound if we slept */
  	if (xprt_bound(xprt)) {
  		status = 0;
  		dprintk("RPC: %5u %s: already bound\n",
  			task->tk_pid, __FUNCTION__);
  		goto bailout_nofree;
  	}
  
  	if (rpcb_next_version[xprt->bind_index].rpc_proc == NULL) {
  		xprt->bind_index = 0;
  		status = -EACCES;	/* tell caller to try again later */
  		dprintk("RPC: %5u %s: no more getport versions available\n",
  			task->tk_pid, __FUNCTION__);
  		goto bailout_nofree;
  	}
  	bind_version = rpcb_next_version[xprt->bind_index].rpc_vers;
  
  	dprintk("RPC: %5u %s: trying rpcbind version %u\n",
  		task->tk_pid, __FUNCTION__, bind_version);
  
  	map = kzalloc(sizeof(struct rpcbind_args), GFP_ATOMIC);
  	if (!map) {
  		status = -ENOMEM;
  		dprintk("RPC: %5u %s: no memory available\n",
  			task->tk_pid, __FUNCTION__);
  		goto bailout_nofree;
  	}
  	map->r_prog = clnt->cl_prog;
  	map->r_vers = clnt->cl_vers;
  	map->r_prot = xprt->prot;
  	map->r_port = 0;
  	map->r_xprt = xprt_get(xprt);
  	map->r_netid = (xprt->prot == IPPROTO_TCP) ? RPCB_NETID_TCP :
  						   RPCB_NETID_UDP;
  	memcpy(&map->r_addr, rpc_peeraddr2str(clnt, RPC_DISPLAY_ADDR),
  			sizeof(map->r_addr));
  	map->r_owner = RPCB_OWNER_STRING;	/* ignored for GETADDR */
  
  	rpc_peeraddr(clnt, (void *)&addr, sizeof(addr));
  	rpcb_clnt = rpcb_create(clnt->cl_server, &addr, xprt->prot, bind_version, 0);
  	if (IS_ERR(rpcb_clnt)) {
  		status = PTR_ERR(rpcb_clnt);
  		dprintk("RPC: %5u %s: rpcb_create failed, error %ld\n",
  			task->tk_pid, __FUNCTION__, PTR_ERR(rpcb_clnt));
  		goto bailout;
  	}
  
  	child = rpc_run_task(rpcb_clnt, RPC_TASK_ASYNC, &rpcb_getport_ops, map);
  	rpc_release_client(rpcb_clnt);
  	if (IS_ERR(child)) {
  		status = -EIO;
  		dprintk("RPC: %5u %s: rpc_run_task failed\n",
  			task->tk_pid, __FUNCTION__);
  		goto bailout_nofree;
  	}
  	rpc_put_task(child);
  
  	task->tk_xprt->stat.bind_count++;
  	return;
  
  bailout:
  	kfree(map);
  	xprt_put(xprt);
  bailout_nofree:
  	rpcb_wake_rpcbind_waiters(xprt, status);
  bailout_nowake:
  	task->tk_status = status;
  }
  
  /*
   * Rpcbind child task calls this callback via tk_exit.
   */
  static void rpcb_getport_done(struct rpc_task *child, void *data)
  {
  	struct rpcbind_args *map = data;
  	struct rpc_xprt *xprt = map->r_xprt;
  	int status = child->tk_status;
  
  	/* rpcbind server doesn't support this rpcbind protocol version */
  	if (status == -EPROTONOSUPPORT)
  		xprt->bind_index++;
  
  	if (status < 0) {
  		/* rpcbind server not available on remote host? */
  		xprt->ops->set_port(xprt, 0);
  	} else if (map->r_port == 0) {
  		/* Requested RPC service wasn't registered on remote host */
  		xprt->ops->set_port(xprt, 0);
  		status = -EACCES;
  	} else {
  		/* Succeeded */
  		xprt->ops->set_port(xprt, map->r_port);
  		xprt_set_bound(xprt);
  		status = 0;
  	}
  
  	dprintk("RPC: %5u rpcb_getport_done(status %d, port %u)\n",
  			child->tk_pid, status, map->r_port);
  
  	rpcb_wake_rpcbind_waiters(xprt, status);
  }
  
  static int rpcb_encode_mapping(struct rpc_rqst *req, __be32 *p,
  			       struct rpcbind_args *rpcb)
  {
  	dprintk("RPC:       rpcb_encode_mapping(%u, %u, %d, %u)\n",
  			rpcb->r_prog, rpcb->r_vers, rpcb->r_prot, rpcb->r_port);
  	*p++ = htonl(rpcb->r_prog);
  	*p++ = htonl(rpcb->r_vers);
  	*p++ = htonl(rpcb->r_prot);
  	*p++ = htonl(rpcb->r_port);
  
  	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
  	return 0;
  }
  
  static int rpcb_decode_getport(struct rpc_rqst *req, __be32 *p,
  			       unsigned short *portp)
  {
  	*portp = (unsigned short) ntohl(*p++);
  	dprintk("RPC:      rpcb_decode_getport result %u\n",
  			*portp);
  	return 0;
  }
  
  static int rpcb_decode_set(struct rpc_rqst *req, __be32 *p,
  			   unsigned int *boolp)
  {
  	*boolp = (unsigned int) ntohl(*p++);
  	dprintk("RPC:      rpcb_decode_set result %u\n",
  			*boolp);
  	return 0;
  }
  
  static int rpcb_encode_getaddr(struct rpc_rqst *req, __be32 *p,
  			       struct rpcbind_args *rpcb)
  {
  	dprintk("RPC:       rpcb_encode_getaddr(%u, %u, %s)\n",
  			rpcb->r_prog, rpcb->r_vers, rpcb->r_addr);
  	*p++ = htonl(rpcb->r_prog);
  	*p++ = htonl(rpcb->r_vers);
  
  	p = xdr_encode_string(p, rpcb->r_netid);
  	p = xdr_encode_string(p, rpcb->r_addr);
  	p = xdr_encode_string(p, rpcb->r_owner);
  
  	req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
  
  	return 0;
  }
  
  static int rpcb_decode_getaddr(struct rpc_rqst *req, __be32 *p,
  			       unsigned short *portp)
  {
  	char *addr;
  	int addr_len, c, i, f, first, val;
  
  	*portp = 0;
  	addr_len = (unsigned int) ntohl(*p++);
  	if (addr_len > RPCB_MAXADDRLEN)			/* sanity */
  		return -EINVAL;
  
  	dprintk("RPC:       rpcb_decode_getaddr returned string: '%s'\n",
  			(char *) p);
  
  	addr = (char *)p;
  	val = 0;
  	first = 1;
  	f = 1;
  	for (i = addr_len - 1; i > 0; i--) {
  		c = addr[i];
  		if (c >= '0' && c <= '9') {
  			val += (c - '0') * f;
  			f *= 10;
  		} else if (c == '.') {
  			if (first) {
  				*portp = val;
  				val = first = 0;
  				f = 1;
  			} else {
  				*portp |= (val << 8);
  				break;
  			}
  		}
  	}
  
  	dprintk("RPC:       rpcb_decode_getaddr port=%u\n", *portp);
  	return 0;
  }
  
  #define RPCB_program_sz		(1u)
  #define RPCB_version_sz		(1u)
  #define RPCB_protocol_sz	(1u)
  #define RPCB_port_sz		(1u)
  #define RPCB_boolean_sz		(1u)
  
  #define RPCB_netid_sz		(1+XDR_QUADLEN(RPCB_MAXNETIDLEN))
  #define RPCB_addr_sz		(1+XDR_QUADLEN(RPCB_MAXADDRLEN))
  #define RPCB_ownerstring_sz	(1+XDR_QUADLEN(RPCB_MAXOWNERLEN))
  
  #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_setres_sz		RPCB_boolean_sz
  #define RPCB_getportres_sz	RPCB_port_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
  
  #define PROC(proc, argtype, restype)					\
  	[RPCBPROC_##proc] = {						\
  		.p_proc		= RPCBPROC_##proc,			\
  		.p_encode	= (kxdrproc_t) rpcb_encode_##argtype,	\
  		.p_decode	= (kxdrproc_t) rpcb_decode_##restype,	\
  		.p_arglen	= RPCB_##argtype##args_sz,		\
  		.p_replen	= RPCB_##restype##res_sz,		\
  		.p_statidx	= RPCBPROC_##proc,			\
  		.p_timer	= 0,					\
  		.p_name		= #proc,				\
  	}
  
  /*
   * Not all rpcbind procedures described in RFC 1833 are implemented
   * since the Linux kernel RPC code requires only these.
   */
  static struct rpc_procinfo rpcb_procedures2[] = {
  	PROC(SET,		mapping,	set),
  	PROC(UNSET,		mapping,	set),
  	PROC(GETADDR,		mapping,	getport),
  };
  
  static struct rpc_procinfo rpcb_procedures3[] = {
  	PROC(SET,		mapping,	set),
  	PROC(UNSET,		mapping,	set),
  	PROC(GETADDR,		getaddr,	getaddr),
  };
  
  static struct rpc_procinfo rpcb_procedures4[] = {
  	PROC(SET,		mapping,	set),
  	PROC(UNSET,		mapping,	set),
  	PROC(GETVERSADDR,	getaddr,	getaddr),
  };
  
  static struct rpcb_info rpcb_next_version[] = {
  #ifdef CONFIG_SUNRPC_BIND34
  	{ 4, &rpcb_procedures4[RPCBPROC_GETVERSADDR] },
  	{ 3, &rpcb_procedures3[RPCBPROC_GETADDR] },
  #endif
  	{ 2, &rpcb_procedures2[RPCBPROC_GETPORT] },
  	{ 0, NULL },
  };
  
  static struct rpc_version rpcb_version2 = {
  	.number		= 2,
  	.nrprocs	= RPCB_HIGHPROC_2,
  	.procs		= rpcb_procedures2
  };
  
  static struct rpc_version rpcb_version3 = {
  	.number		= 3,
  	.nrprocs	= RPCB_HIGHPROC_3,
  	.procs		= rpcb_procedures3
  };
  
  static struct rpc_version rpcb_version4 = {
  	.number		= 4,
  	.nrprocs	= RPCB_HIGHPROC_4,
  	.procs		= rpcb_procedures4
  };
  
  static struct rpc_version *rpcb_version[] = {
  	NULL,
  	NULL,
  	&rpcb_version2,
  	&rpcb_version3,
  	&rpcb_version4
  };
  
  static struct rpc_stat rpcb_stats;
  
  struct rpc_program rpcb_program = {
  	.name		= "rpcbind",
  	.number		= RPCBIND_PROGRAM,
  	.nrvers		= ARRAY_SIZE(rpcb_version),
  	.version	= rpcb_version,
  	.stats		= &rpcb_stats,
  };
  