ucblib/librpcsoc/clnt_tcp.c

	clnt_tcp.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * 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.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

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

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 */
    u_int       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(raddr, prog, vers, sockp, sendsz, recvsz)
    struct sockaddr_in *raddr;
    rpcprog_t prog;
    rpcvers_t vers;
    register int *sockp;
    u_int sendsz;
    u_int recvsz;
{
    CLIENT *h;
    register struct ct_data *ct;
    struct timeval now;
    struct rpc_msg call_msg;
    int i;

    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) {
        u_short 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);
        i = 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 ((CLIENT *)NULL);
}

static enum clnt_stat
clnttcp_call(h, proc, xdr_args, args_ptr, xdr_results, results_ptr, timeout)
    register CLIENT *h;
    rpcproc_t proc;
    xdrproc_t xdr_args;
    caddr_t args_ptr;
    xdrproc_t xdr_results;
    caddr_t results_ptr;
    struct timeval timeout;
{
    register struct ct_data *ct = (struct ct_data *) h->cl_private;
    register XDR *xdrs = &(ct->ct_xdrs);
    struct rpc_msg reply_msg;
    uint32_t x_id;
    uint32_t *msg_x_id = (uint32_t *)(ct->ct_mcall);    /* yuk */
    register bool_t shipnow;
    int 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(h, errp)
    CLIENT *h;
    struct rpc_err *errp;
{
    register struct ct_data *ct =
        (struct ct_data *) h->cl_private;

    *errp = ct->ct_error;
}

static bool_t
clnttcp_freeres(cl, xdr_res, res_ptr)
    CLIENT *cl;
    xdrproc_t xdr_res;
    caddr_t res_ptr;
{
    register struct ct_data *ct = (struct ct_data *)cl->cl_private;
    register XDR *xdrs = &(ct->ct_xdrs);

    xdrs->x_op = XDR_FREE;
    return ((*xdr_res)(xdrs, res_ptr));
}

static void
clnttcp_abort()
{
}

static bool_t
clnttcp_control(cl, request, info)
    CLIENT *cl;
    int request;
    char *info;
{
    register struct ct_data *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(h)
    CLIENT *h;
{
    register struct ct_data *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(ct, buf, len)
    register struct ct_data *ct;
    caddr_t buf;
    register int len;
{
    fd_set mask;
    fd_set readfds;

    if (len == 0)
        return (0);
    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(ct, buf, len)
    struct ct_data *ct;
    caddr_t buf;
    int len;
{
    register int i, cnt;

    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()
{
    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);
}