xref: /illumos-gate/usr/src/ucblib/librpcsoc/clnt_tcp.c (revision 2b208da6458bdbaad9f45832216da636f9184765)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1990 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*
 * Copyright (c) 1984, 1986, 1987, 1988, 1989, 1996 AT&T
 * All Rights Reserved
 */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
 *
 * TCP based RPC supports 'batched calls'.
 * A sequence of calls may be batched-up in a send buffer.  The rpc call
 * return immediately to the client even though the call was not necessarily
 * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
 * the rpc timeout value is zero (see clnt.h, rpc).
 *
 * Clients should NOT casually batch calls that in fact return results; that is,
 * the server side should be aware that a call is batched and not produce any
 * return message.  Batched calls that produce many result messages can
 * deadlock (netlock) the client and the server....
 *
 * Now go hang yourself.
 */

#include <rpc/rpc.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/pmap_clnt.h>
#include <syslog.h>
#include <malloc.h>
#include <stdio.h>

#define	MCALL_MSG_SIZE 24

extern int errno;

static int readtcp(void *, caddr_t, int);
static int writetcp(void *, caddr_t, int);
extern int _socket(int, int, int);
extern pid_t getpid(void);
extern int bindresvport(int, struct sockaddr_in *);
extern bool_t xdr_opaque_auth(XDR *, struct opaque_auth *);
static struct clnt_ops *clnttcp_ops(void);

struct ct_data {
	int		ct_sock;
	bool_t		ct_closeit;
	struct timeval	ct_wait;
	bool_t		ct_waitset;	/* wait set by clnt_control? */
	struct sockaddr_in ct_addr;
	struct rpc_err	ct_error;
	char		ct_mcall[MCALL_MSG_SIZE];	/* marshalled callmsg */
	uint_t		ct_mpos;			/* pos after marshal */
	XDR		ct_xdrs;
};

/*
 * Create a client handle for a tcp/ip connection.
 * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 * connected to raddr.  If *sockp non-negative then
 * raddr is ignored.  The rpc/tcp package does buffering
 * similar to stdio, so the client must pick send and receive buffer sizes
 * 0 => use the default.
 * If raddr->sin_port is 0, then a binder on the remote machine is
 * consulted for the right port number.
 * NB: *sockp is copied into a private area.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is set null authentication.  Caller may wish to
 * set this something more useful.
 */
CLIENT *
clnttcp_create(struct sockaddr_in *raddr, rpcprog_t prog, rpcvers_t vers,
    int *sockp, uint_t sendsz, uint_t recvsz)
{
	CLIENT *h;
	struct ct_data *ct;
	struct timeval now;
	struct rpc_msg call_msg;

	h  = (CLIENT *)mem_alloc(sizeof (*h));
	if (h == NULL) {
		(void) syslog(LOG_ERR, "clnttcp_create: out of memory");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}
	ct = (struct ct_data *)mem_alloc(sizeof (*ct));
	if (ct == NULL) {
		(void) syslog(LOG_ERR, "clnttcp_create: out of memory");
		rpc_createerr.cf_stat = RPC_SYSTEMERROR;
		rpc_createerr.cf_error.re_errno = errno;
		goto fooy;
	}

	/*
	 * If no port number given ask the pmap for one
	 */
	if (raddr->sin_port == 0) {
		ushort_t port;
		if ((port = pmap_getport(raddr, prog, vers, IPPROTO_TCP))
		    == 0) {
			mem_free((caddr_t)ct, sizeof (struct ct_data));
			mem_free((caddr_t)h, sizeof (CLIENT));
			return ((CLIENT *)NULL);
		}
		raddr->sin_port = htons(port);
	}

	/*
	 * If no socket given, open one
	 */
	if (*sockp < 0) {
		*sockp = _socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
		(void) bindresvport(*sockp, (struct sockaddr_in *)0);
		if ((*sockp < 0)||
		    (connect(*sockp, (struct sockaddr *)raddr,
		    sizeof (*raddr)) < 0)) {
			rpc_createerr.cf_stat = RPC_SYSTEMERROR;
			rpc_createerr.cf_error.re_errno = errno;
			(void) close(*sockp);
			goto fooy;
		}
		ct->ct_closeit = TRUE;
	} else {
		ct->ct_closeit = FALSE;
	}

	/*
	 * Set up private data struct
	 */
	ct->ct_sock = *sockp;
	ct->ct_wait.tv_usec = 0;
	ct->ct_waitset = FALSE;
	ct->ct_addr = *raddr;

	/*
	 * Initialize call message
	 */
	(void) gettimeofday(&now, (struct timezone *)0);
	call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
	call_msg.rm_direction = CALL;
	call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
	call_msg.rm_call.cb_prog = prog;
	call_msg.rm_call.cb_vers = vers;

	/*
	 * pre-serialize the staic part of the call msg and stash it away
	 */
	xdrmem_create(&(ct->ct_xdrs), ct->ct_mcall, MCALL_MSG_SIZE,
	    XDR_ENCODE);
	if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
		if (ct->ct_closeit) {
			(void) close(*sockp);
		}
		goto fooy;
	}
	ct->ct_mpos = XDR_GETPOS(&(ct->ct_xdrs));
	XDR_DESTROY(&(ct->ct_xdrs));

	/*
	 * Create a client handle which uses xdrrec for serialization
	 * and authnone for authentication.
	 */
	xdrrec_create(&(ct->ct_xdrs), sendsz, recvsz,
	    (caddr_t)ct, readtcp, writetcp);
	h->cl_ops = clnttcp_ops();
	h->cl_private = (caddr_t)ct;
	h->cl_auth = authnone_create();
	return (h);

fooy:
	/*
	 * Something goofed, free stuff and barf
	 */
	mem_free((caddr_t)ct, sizeof (struct ct_data));
	mem_free((caddr_t)h, sizeof (CLIENT));
	return (NULL);
}

static enum clnt_stat
clnttcp_call(CLIENT *h, rpcproc_t proc, xdrproc_t xdr_args, caddr_t args_ptr,
    xdrproc_t xdr_results, caddr_t results_ptr, struct timeval timeout)
{
	struct ct_data *ct;
	XDR *xdrs;
	struct rpc_msg reply_msg;
	uint32_t x_id;
	uint32_t *msg_x_id;
	bool_t shipnow;
	int refreshes;

	ct = (struct ct_data *)h->cl_private;
	xdrs = &(ct->ct_xdrs);
	msg_x_id = (uint32_t *)(ct->ct_mcall);	/* yuk */
	refreshes = 2;

	if (!ct->ct_waitset) {
		ct->ct_wait = timeout;
	}

	shipnow =
	    (xdr_results == (xdrproc_t)0 && timeout.tv_sec == 0 &&
	    timeout.tv_usec == 0) ? FALSE : TRUE;

call_again:
	xdrs->x_op = XDR_ENCODE;
	ct->ct_error.re_status = RPC_SUCCESS;
	x_id = ntohl(--(*msg_x_id));
	if ((! XDR_PUTBYTES(xdrs, ct->ct_mcall, ct->ct_mpos)) ||
	    (! XDR_PUTINT32(xdrs, (int32_t *)&proc)) ||
	    (! AUTH_MARSHALL(h->cl_auth, xdrs)) ||
	    (! (*xdr_args)(xdrs, args_ptr))) {
		if (ct->ct_error.re_status == RPC_SUCCESS)
			ct->ct_error.re_status = RPC_CANTENCODEARGS;
		(void) xdrrec_endofrecord(xdrs, TRUE);
		return (ct->ct_error.re_status);
	}
	if (! xdrrec_endofrecord(xdrs, shipnow))
		return (ct->ct_error.re_status = RPC_CANTSEND);
	if (! shipnow)
		return (RPC_SUCCESS);
	/*
	 * Hack to provide rpc-based message passing
	 */
	if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
		return (ct->ct_error.re_status = RPC_TIMEDOUT);
	}


	/*
	 * Keep receiving until we get a valid transaction id
	 */
	xdrs->x_op = XDR_DECODE;
	while (TRUE) {
		reply_msg.acpted_rply.ar_verf = _null_auth;
		reply_msg.acpted_rply.ar_results.where = NULL;
		reply_msg.acpted_rply.ar_results.proc = xdr_void;
		if (! xdrrec_skiprecord(xdrs))
			return (ct->ct_error.re_status);
			/* now decode and validate the response header */
		if (! xdr_replymsg(xdrs, &reply_msg)) {
			if (ct->ct_error.re_status == RPC_SUCCESS)
				continue;
			return (ct->ct_error.re_status);
		}
		if (reply_msg.rm_xid == x_id)
			break;
	}

	/*
	 * process header
	 */
	__seterr_reply(&reply_msg, &(ct->ct_error));
	if (ct->ct_error.re_status == RPC_SUCCESS) {
		if (! AUTH_VALIDATE(h->cl_auth,
		    &reply_msg.acpted_rply.ar_verf)) {
			ct->ct_error.re_status = RPC_AUTHERROR;
			ct->ct_error.re_why = AUTH_INVALIDRESP;
		} else if (! (*xdr_results)(xdrs, results_ptr)) {
			if (ct->ct_error.re_status == RPC_SUCCESS)
				ct->ct_error.re_status = RPC_CANTDECODERES;
		}
		/* free verifier ... */
		if (reply_msg.acpted_rply.ar_verf.oa_base != NULL) {
			xdrs->x_op = XDR_FREE;
			(void) xdr_opaque_auth(xdrs,
			    &(reply_msg.acpted_rply.ar_verf));
		}
	}  /* end successful completion */
	else {
		/* maybe our credentials need to be refreshed ... */
		if (refreshes-- && AUTH_REFRESH(h->cl_auth, &reply_msg))
			goto call_again;
	}  /* end of unsuccessful completion */
	return (ct->ct_error.re_status);
}

static void
clnttcp_geterr(CLIENT *h, struct rpc_err *errp)
{
	struct ct_data *ct;

	ct = (struct ct_data *)h->cl_private;
	*errp = ct->ct_error;
}

static bool_t
clnttcp_freeres(CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)
{
	struct ct_data *ct;
	XDR *xdrs;

	ct = (struct ct_data *)cl->cl_private;
	xdrs = &(ct->ct_xdrs);
	xdrs->x_op = XDR_FREE;
	return ((*xdr_res)(xdrs, res_ptr));
}

static void
clnttcp_abort(void)
{
}

static bool_t
clnttcp_control(CLIENT *cl, int request, char *info)
{
	struct ct_data *ct;

	ct = (struct ct_data *)cl->cl_private;
	switch (request) {
	case CLSET_TIMEOUT:
		ct->ct_wait = *(struct timeval *)info;
		ct->ct_waitset = TRUE;
		break;
	case CLGET_TIMEOUT:
		*(struct timeval *)info = ct->ct_wait;
		break;
	case CLGET_SERVER_ADDR:
		*(struct sockaddr_in *)info = ct->ct_addr;
		break;
	case CLGET_FD:
		*(int *)info = ct->ct_sock;
		break;
	case CLSET_FD_CLOSE:
		ct->ct_closeit = TRUE;
		break;
	case CLSET_FD_NCLOSE:
		ct->ct_closeit = FALSE;
		break;
	default:
		return (FALSE);
	}
	return (TRUE);
}


static void
clnttcp_destroy(CLIENT *h)
{
	struct ct_data *ct;

	ct = (struct ct_data *)h->cl_private;
	if (ct->ct_closeit) {
		(void) close(ct->ct_sock);
	}
	XDR_DESTROY(&(ct->ct_xdrs));
	mem_free((caddr_t)ct, sizeof (struct ct_data));
	mem_free((caddr_t)h, sizeof (CLIENT));
}

/*
 * Interface between xdr serializer and tcp connection.
 * Behaves like the system calls, read & write, but keeps some error state
 * around for the rpc level.
 */
static int
readtcp(void *data, caddr_t buf, int len)
{
	fd_set mask;
	fd_set readfds;
	struct ct_data *ct;

	if (len == 0)
		return (0);

	ct = data;
	FD_ZERO(&mask);
	FD_SET(ct->ct_sock, &mask);
	while (TRUE) {
		readfds = mask;
		switch (select(__rpc_dtbsize(),
		    &readfds, NULL, NULL, &(ct->ct_wait))) {
		case 0:
			ct->ct_error.re_status = RPC_TIMEDOUT;
			return (-1);

		case -1:
			if (errno == EINTR)
				continue;
			ct->ct_error.re_status = RPC_CANTRECV;
			ct->ct_error.re_errno = errno;
			return (-1);
		}
		break;
	}
	switch (len = read(ct->ct_sock, buf, len)) {

	case 0:
		/* premature eof */
		ct->ct_error.re_errno = ECONNRESET;
		ct->ct_error.re_status = RPC_CANTRECV;
		len = -1;  /* it's really an error */
		break;

	case -1:
		ct->ct_error.re_errno = errno;
		ct->ct_error.re_status = RPC_CANTRECV;
		break;
	}
	return (len);
}

static int
writetcp(void *data, caddr_t buf, int len)
{
	struct ct_data *ct;
	int i, cnt;

	ct = data;
	for (cnt = len; cnt > 0; cnt -= i, buf += i) {
		if ((i = write(ct->ct_sock, buf, cnt)) == -1) {
			ct->ct_error.re_errno = errno;
			ct->ct_error.re_status = RPC_CANTSEND;
			return (-1);
		}
	}
	return (len);
}

static struct clnt_ops *
clnttcp_ops(void)
{
	static struct clnt_ops ops;

	if (ops.cl_call == NULL) {
		ops.cl_call = clnttcp_call;
		ops.cl_abort = clnttcp_abort;
		ops.cl_geterr = clnttcp_geterr;
		ops.cl_freeres = clnttcp_freeres;
		ops.cl_destroy = clnttcp_destroy;
		ops.cl_control = clnttcp_control;
	}
	return (&ops);
}