ucblib/librpcsoc/clnt_udp.c

/*
 * 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 2004 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_udp.c, Implements a UDP/IP based, client side RPC.
 */

#include <rpc/rpc.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/ioctl.h>
#include <netdb.h>
#include <errno.h>
#include <rpc/pmap_clnt.h>
#include <rpc/clnt_soc.h>
#include <syslog.h>
#include <sys/filio.h>
#include <malloc.h>
#include <unistd.h>
#include <stropts.h>
#include <stdio.h>


extern int errno;

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 *);
extern int _sendto(int, const char *, int, int,
    const struct sockaddr *, int);
extern int _recvfrom(int, char *, int, int,
    struct sockaddr *, int *);


static struct clnt_ops *clntudp_ops();

/*
 * Private data kept per client handle
 */
struct cu_data {
    int        cu_sock;
    bool_t         cu_closeit;
    struct sockaddr_in cu_raddr;
    int        cu_rlen;
    struct timeval     cu_wait;
    struct timeval     cu_total;
    struct rpc_err     cu_error;
    XDR        cu_outxdrs;
    u_int          cu_xdrpos;
    u_int          cu_sendsz;
    char           *cu_outbuf;
    u_int          cu_recvsz;
    char           cu_inbuf[1];
};

/*
 * Create a UDP based client handle.
 * If *sockp<0, *sockp is set to a newly created UPD socket.
 * If raddr->sin_port is 0 a binder on the remote machine
 * is consulted for the correct port number.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is initialized to null authentication.
 *  Caller may wish to set this something more useful.
 *
 * wait is the amount of time used between retransmitting a call if
 * no response has been heard;  retransmition occurs until the actual
 * rpc call times out.
 *
 * sendsz and recvsz are the maximum allowable packet sizes that can be
 * sent and received.
 */
CLIENT *
clntudp_bufcreate(raddr, program, version, wait, sockp, sendsz, recvsz)
    struct sockaddr_in *raddr;
    rpcprog_t program;
    rpcvers_t version;
    struct timeval wait;
    register int *sockp;
    u_int sendsz;
    u_int recvsz;
{
    CLIENT *cl;
    register struct cu_data *cu;
    struct timeval now;
    struct rpc_msg call_msg;

    cl = (CLIENT *)mem_alloc(sizeof (CLIENT));
    if (cl == NULL) {
        (void) syslog(LOG_ERR, "clntudp_create: out of memory");
        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
        rpc_createerr.cf_error.re_errno = errno;
        goto fooy;
    }
    sendsz = ((sendsz + 3) / 4) * 4;
    recvsz = ((recvsz + 3) / 4) * 4;
    cu = (struct cu_data *)mem_alloc(sizeof (*cu) + sendsz + recvsz);
    if (cu == NULL) {
        (void) syslog(LOG_ERR, "clntudp_create: out of memory");
        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
        rpc_createerr.cf_error.re_errno = errno;
        goto fooy;
    }
    cu->cu_outbuf = &cu->cu_inbuf[recvsz];

    (void) gettimeofday(&now, (struct timezone *)0);
    if (raddr->sin_port == 0) {
        u_short port;
        if ((port =
            pmap_getport(raddr, program, version, IPPROTO_UDP)) == 0) {
            goto fooy;
        }
        raddr->sin_port = htons(port);
    }
    cl->cl_ops = clntudp_ops();
    cl->cl_private = (caddr_t)cu;
    cu->cu_raddr = *raddr;
    cu->cu_rlen = sizeof (cu->cu_raddr);
    cu->cu_wait = wait;
    cu->cu_total.tv_sec = -1;
    cu->cu_total.tv_usec = -1;
    cu->cu_sendsz = sendsz;
    cu->cu_recvsz = recvsz;
    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 = program;
    call_msg.rm_call.cb_vers = version;
    xdrmem_create(&(cu->cu_outxdrs), cu->cu_outbuf,
        sendsz, XDR_ENCODE);
    if (! xdr_callhdr(&(cu->cu_outxdrs), &call_msg)) {
        goto fooy;
    }
    cu->cu_xdrpos = XDR_GETPOS(&(cu->cu_outxdrs));
    if (*sockp < 0) {
        int dontblock = 1;

        *sockp = _socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        if (*sockp < 0) {
            rpc_createerr.cf_stat = RPC_SYSTEMERROR;
            rpc_createerr.cf_error.re_errno = errno;
            goto fooy;
        }
        /* attempt to bind to prov port */
        (void) bindresvport(*sockp, (struct sockaddr_in *)0);
        /* the sockets rpc controls are non-blocking */
        (void) ioctl(*sockp, FIONBIO, (char *) &dontblock);
        cu->cu_closeit = TRUE;
    } else {
        cu->cu_closeit = FALSE;
    }
    cu->cu_sock = *sockp;
    cl->cl_auth = authnone_create();
    return (cl);
fooy:
    if (cu)
        mem_free((caddr_t)cu, sizeof (*cu) + sendsz + recvsz);
    if (cl)
        mem_free((caddr_t)cl, sizeof (CLIENT));
    return ((CLIENT *)NULL);
}

CLIENT *
clntudp_create(raddr, program, version, wait, sockp)
    struct sockaddr_in *raddr;
    rpcprog_t program;
    rpcvers_t version;
    struct timeval wait;
    register int *sockp;
{

    return (clntudp_bufcreate(raddr, program, version, wait, sockp,
        UDPMSGSIZE, UDPMSGSIZE));
}

static enum clnt_stat
clntudp_call(cl, proc, xargs, argsp, xresults, resultsp, utimeout)
    register CLIENT *cl;        /* client handle */
    rpcproc_t   proc;       /* procedure number */
    xdrproc_t   xargs;      /* xdr routine for args */
    caddr_t     argsp;      /* pointer to args */
    xdrproc_t   xresults;   /* xdr routine for results */
    caddr_t     resultsp;   /* pointer to results */
    struct timeval  utimeout;   /* seconds to wait before giving up */
{
    register struct cu_data *cu = (struct cu_data *)cl->cl_private;
    register XDR *xdrs;
    register int outlen;
    register int inlen;
    int fromlen;
    fd_set readfds;
    fd_set mask;
    struct sockaddr_in from;
    struct rpc_msg reply_msg;
    XDR reply_xdrs;
    struct timeval startime, curtime;
    int firsttimeout = 1;
    struct timeval time_waited;
    struct timeval retransmit_time;
    bool_t ok;
    int nrefreshes = 2; /* number of times to refresh cred */
    struct timeval timeout;

    if (cu->cu_total.tv_usec == -1) {
        timeout = utimeout; /* use supplied timeout */
    } else {
        timeout = cu->cu_total; /* use default timeout */
    }

    time_waited.tv_sec = 0;
    time_waited.tv_usec = 0;
    retransmit_time = cu->cu_wait;

call_again:
    xdrs = &(cu->cu_outxdrs);
    xdrs->x_op = XDR_ENCODE;
    XDR_SETPOS(xdrs, cu->cu_xdrpos);
    /*
     * the transaction is the first thing in the out buffer
     */
    (*(u_short *)(cu->cu_outbuf))++;
    if ((! XDR_PUTINT32(xdrs, (int32_t *)&proc)) ||
        (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
        (! (*xargs)(xdrs, argsp)))
        return (cu->cu_error.re_status = RPC_CANTENCODEARGS);
    outlen = (int)XDR_GETPOS(xdrs);

send_again:
    if (_sendto(cu->cu_sock, cu->cu_outbuf, outlen, 0,
        (struct sockaddr *)&(cu->cu_raddr), cu->cu_rlen)
        != outlen) {
        cu->cu_error.re_errno = errno;
        return (cu->cu_error.re_status = RPC_CANTSEND);
    }

    /*
     * Hack to provide rpc-based message passing
     */
    if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
        return (cu->cu_error.re_status = RPC_TIMEDOUT);
    }
    /*
     * sub-optimal code appears here because we have
     * some clock time to spare while the packets are in flight.
     * (We assume that this is actually only executed once.)
     */
    reply_msg.acpted_rply.ar_verf = _null_auth;
    reply_msg.acpted_rply.ar_results.where = resultsp;
    reply_msg.acpted_rply.ar_results.proc = xresults;
    FD_ZERO(&mask);
    FD_SET(cu->cu_sock, &mask);
    for (;;) {
        readfds = mask;
        switch (select(__rpc_dtbsize(), &readfds, NULL,
            NULL, &(retransmit_time))) {

        case 0:
            time_waited.tv_sec += retransmit_time.tv_sec;
            time_waited.tv_usec += retransmit_time.tv_usec;
            while (time_waited.tv_usec >= 1000000) {
                time_waited.tv_sec++;
                time_waited.tv_usec -= 1000000;
            }

            /* update retransmit_time */

            if (retransmit_time.tv_sec < RPC_MAX_BACKOFF) {
            retransmit_time.tv_usec += retransmit_time.tv_usec;
            retransmit_time.tv_sec += retransmit_time.tv_sec;
            while (retransmit_time.tv_usec >= 1000000) {
                retransmit_time.tv_sec++;
                retransmit_time.tv_usec -= 1000000;
                }
            }

            if ((time_waited.tv_sec < timeout.tv_sec) ||
                ((time_waited.tv_sec == timeout.tv_sec) &&
                (time_waited.tv_usec < timeout.tv_usec)))
                goto send_again;
            return (cu->cu_error.re_status = RPC_TIMEDOUT);

        /*
         * buggy in other cases because time_waited is not being
         * updated.
         */
        case -1:
            if (errno != EINTR) {
                cu->cu_error.re_errno = errno;
                return (cu->cu_error.re_status = RPC_CANTRECV);
            }

            /* interrupted by another signal, update time_waited */
            if (firsttimeout) {
                /*
                 * Could have done gettimeofday before clnt_call
                 * but that means 1 more system call per each
                 * clnt_call, so do it after first time out
                 */
                if (gettimeofday(&startime,
                    (struct timezone *) NULL) == -1) {
                    errno = 0;
                    continue;
                }
                firsttimeout = 0;
                errno = 0;
                continue;
            };

            if (gettimeofday(&curtime,
                (struct timezone *) NULL) == -1) {
                errno = 0;
                continue;
            };

            time_waited.tv_sec += curtime.tv_sec - startime.tv_sec;
            time_waited.tv_usec += curtime.tv_usec -
                            startime.tv_usec;
            while (time_waited.tv_usec < 0) {
                time_waited.tv_sec--;
                time_waited.tv_usec += 1000000;
            };
            while (time_waited.tv_usec >= 1000000) {
                time_waited.tv_sec++;
                time_waited.tv_usec -= 1000000;
            }
            startime.tv_sec = curtime.tv_sec;
            startime.tv_usec = curtime.tv_usec;
            if ((time_waited.tv_sec > timeout.tv_sec) ||
                ((time_waited.tv_sec == timeout.tv_sec) &&
                (time_waited.tv_usec > timeout.tv_usec))) {
                return (cu->cu_error.re_status = RPC_TIMEDOUT);
            }
            errno = 0; /* reset it */
            continue;

        }
        do {
            fromlen = sizeof (struct sockaddr);
            inlen = _recvfrom(cu->cu_sock, cu->cu_inbuf,
                (int) cu->cu_recvsz, 0,
                (struct sockaddr *)&from, &fromlen);
        } while (inlen < 0 && errno == EINTR);
        if (inlen < 0) {
            if (errno == EWOULDBLOCK)
                continue;
            cu->cu_error.re_errno = errno;
            return (cu->cu_error.re_status = RPC_CANTRECV);
        }
        if (inlen < sizeof (uint32_t))
            continue;
        /* see if reply transaction id matches sent id */
        if (*((uint32_t *)(cu->cu_inbuf)) !=
                *((uint32_t *)(cu->cu_outbuf)))
            continue;
        /* we now assume we have the proper reply */
        break;
    }

    /*
     * now decode and validate the response
     */
    xdrmem_create(&reply_xdrs, cu->cu_inbuf, (u_int)inlen, XDR_DECODE);
    ok = xdr_replymsg(&reply_xdrs, &reply_msg);
    /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */
    if (ok) {
        __seterr_reply(&reply_msg, &(cu->cu_error));
        if (cu->cu_error.re_status == RPC_SUCCESS) {
            if (! AUTH_VALIDATE(cl->cl_auth,
                &reply_msg.acpted_rply.ar_verf)) {
                cu->cu_error.re_status = RPC_AUTHERROR;
                cu->cu_error.re_why = AUTH_INVALIDRESP;
            }
            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 (nrefreshes > 0 &&
                AUTH_REFRESH(cl->cl_auth, &reply_msg)) {
                nrefreshes--;
                goto call_again;
            }
        }  /* end of unsuccessful completion */
    }  /* end of valid reply message */
    else {
        cu->cu_error.re_status = RPC_CANTDECODERES;
    }
    return (cu->cu_error.re_status);
}

static void
clntudp_geterr(cl, errp)
    CLIENT *cl;
    struct rpc_err *errp;
{
    register struct cu_data *cu = (struct cu_data *)cl->cl_private;

    *errp = cu->cu_error;
}


static bool_t
clntudp_freeres(cl, xdr_res, res_ptr)
    CLIENT *cl;
    xdrproc_t xdr_res;
    caddr_t res_ptr;
{
    register struct cu_data *cu = (struct cu_data *)cl->cl_private;
    register XDR *xdrs = &(cu->cu_outxdrs);

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

static void
clntudp_abort()
    /* CLIENT *h; */
{
}

static bool_t
clntudp_control(cl, request, info)
    CLIENT *cl;
    int request;
    char *info;
{
    register struct cu_data *cu = (struct cu_data *)cl->cl_private;

    switch (request) {
    case CLSET_TIMEOUT:
        cu->cu_total = *(struct timeval *)info;
        break;
    case CLGET_TIMEOUT:
        *(struct timeval *)info = cu->cu_total;
        break;
    case CLSET_RETRY_TIMEOUT:
        cu->cu_wait = *(struct timeval *)info;
        break;
    case CLGET_RETRY_TIMEOUT:
        *(struct timeval *)info = cu->cu_wait;
        break;
    case CLGET_SERVER_ADDR:
        *(struct sockaddr_in *)info = cu->cu_raddr;
        break;
    case CLGET_FD:
        *(int *)info = cu->cu_sock;
        break;
    case CLSET_FD_CLOSE:
        cu->cu_closeit = TRUE;
        break;
    case CLSET_FD_NCLOSE:
        cu->cu_closeit = FALSE;
        break;
    default:
        return (FALSE);
    }
    return (TRUE);
}

static void
clntudp_destroy(cl)
    CLIENT *cl;
{
    register struct cu_data *cu = (struct cu_data *)cl->cl_private;

    if (cu->cu_closeit) {
        (void) close(cu->cu_sock);
    }
    XDR_DESTROY(&(cu->cu_outxdrs));
    mem_free((caddr_t)cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));
    mem_free((caddr_t)cl, sizeof (CLIENT));
}

static struct clnt_ops *
clntudp_ops()
{
    static struct clnt_ops ops;

    if (ops.cl_call == NULL) {
        ops.cl_call = clntudp_call;
        ops.cl_abort = clntudp_abort;
        ops.cl_geterr = clntudp_geterr;
        ops.cl_freeres = clntudp_freeres;
        ops.cl_destroy = clntudp_destroy;
        ops.cl_control = clntudp_control;
    }
    return (&ops);
}