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[dragonfly.git] / usr.sbin / ypbind / yp_ping.c

/*
 * Copyright (c) 1996, 1997
 *      Bill Paul <wpaul@ctr.columbia.edu>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by Bill Paul.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL Bill Paul OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * @(#)from: clnt_udp.c 1.39 87/08/11 Copyr 1984 Sun Micro
 * @(#)from: clnt_udp.c 2.2 88/08/01 4.0 RPCSRC
 * $FreeBSD: src/usr.sbin/ypbind/yp_ping.c,v 1.6.2.1 2002/02/15 00:46:59 des Exp $
 * $DragonFly: src/usr.sbin/ypbind/yp_ping.c,v 1.7 2005/11/24 22:23:02 swildner Exp $
 */

/*
 * What follows is a special version of clntudp_call() that has been
 * hacked to send requests and receive replies asynchronously. Similar
 * magic is used inside rpc.nisd(8) for the special non-blocking,
 * non-fork()ing, non-threading callback support.
 */

/*
 * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
 * unrestricted use provided that this legend is included on all tape
 * media and as a part of the software program in whole or part.  Users
 * may copy or modify Sun RPC without charge, but are not authorized
 * to license or distribute it to anyone else except as part of a product or
 * program developed by the user.
 *
 * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
 * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
 *
 * Sun RPC is provided with no support and without any obligation on the
 * part of Sun Microsystems, Inc. to assist in its use, correction,
 * modification or enhancement.
 *
 * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
 * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
 * OR ANY PART THEREOF.
 *
 * In no event will Sun Microsystems, Inc. be liable for any lost revenue
 * or profits or other special, indirect and consequential damages, even if
 * Sun has been advised of the possibility of such damages.
 *
 * Sun Microsystems, Inc.
 * 2550 Garcia Avenue
 * Mountain View, California  94043
 */

/*
 * clnt_udp.c, Implements a UDP/IP based, client side RPC.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#include <rpc/pmap_prot.h>
#include <rpcsvc/yp.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include "yp_ping.h"

#ifndef timeradd
#ifndef _KERNEL         /* use timevaladd/timevalsub in kernel */
/* NetBSD/OpenBSD compatible interfaces */
#define timeradd(tvp, uvp, vvp)                                         \
        do {                                                            \
                (vvp)->tv_sec = (tvp)->tv_sec + (uvp)->tv_sec;          \
                (vvp)->tv_usec = (tvp)->tv_usec + (uvp)->tv_usec;       \
                if ((vvp)->tv_usec >= 1000000) {                        \
                        (vvp)->tv_sec++;                                \
                        (vvp)->tv_usec -= 1000000;                      \
                }                                                       \
        } while (0)
#define timersub(tvp, uvp, vvp)                                         \
        do {                                                            \
                (vvp)->tv_sec = (tvp)->tv_sec - (uvp)->tv_sec;          \
                (vvp)->tv_usec = (tvp)->tv_usec - (uvp)->tv_usec;       \
                if ((vvp)->tv_usec < 0) {                               \
                        (vvp)->tv_sec--;                                \
                        (vvp)->tv_usec += 1000000;                      \
                }                                                       \
        } while (0)
#endif
#endif

/*
 * 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];
};

static enum clnt_stat
clntudp_a_call(CLIENT *cl,              /* client handle */
               u_long 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 */
{
        struct cu_data *cu = (struct cu_data *)cl->cl_private;
        XDR *xdrs;
        int outlen = 0;
        int inlen;
        int fromlen;
        fd_set *fds, readfds;
        struct sockaddr_in from;
        struct rpc_msg reply_msg;
        XDR reply_xdrs;
        struct timeval time_waited, start, after, tmp1, tmp2, tv;
        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 */

        if (cu->cu_sock + 1 > FD_SETSIZE) {
                int bytes = howmany(cu->cu_sock + 1, NFDBITS) * sizeof(fd_mask);
                fds = (fd_set *)malloc(bytes);
                if (fds == NULL)
                        return (cu->cu_error.re_status = RPC_CANTSEND);
                memset(fds, 0, bytes);
        } else {
                fds = &readfds;
                FD_ZERO(fds);
        }

        timerclear(&time_waited);

call_again:
        xdrs = &(cu->cu_outxdrs);
        if (xargs == NULL)
                goto get_reply;
        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_PUTLONG(xdrs, (long *)&proc)) ||
            (! AUTH_MARSHALL(cl->cl_auth, xdrs)) ||
            (! (*xargs)(xdrs, argsp))) {
                if (fds != &readfds)
                        free(fds);
                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;
                if (fds != &readfds)
                        free(fds);
                return (cu->cu_error.re_status = RPC_CANTSEND);
        }

        /*
         * Hack to provide rpc-based message passing
         */
        if (!timerisset(&timeout)) {
                if (fds != &readfds)
                        free(fds);
                return (cu->cu_error.re_status = RPC_TIMEDOUT);
        }

get_reply:

        /*
         * 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;

        gettimeofday(&start, NULL);
        for (;;) {
                /* XXX we know the other bits are still clear */
                FD_SET(cu->cu_sock, fds);
                tv = cu->cu_wait;
                switch (select(cu->cu_sock+1, fds, NULL, NULL, &tv)) {

                case 0:
                        timeradd(&time_waited, &cu->cu_wait, &tmp1);
                        time_waited = tmp1;
                        if (timercmp(&time_waited, &timeout, <))
                                goto send_again;
                        if (fds != &readfds)
                                free(fds);
                        return (cu->cu_error.re_status = RPC_TIMEDOUT);

                case -1:
                        if (errno == EINTR) {
                                gettimeofday(&after, NULL);
                                timersub(&after, &start, &tmp1);
                                timeradd(&time_waited, &tmp1, &tmp2);
                                time_waited = tmp2;
                                if (timercmp(&time_waited, &timeout, <))
                                        continue;
                                if (fds != &readfds)
                                        free(fds);
                                return (cu->cu_error.re_status = RPC_TIMEDOUT);
                        }
                        cu->cu_error.re_errno = errno;
                        if (fds != &readfds)
                                free(fds);
                        return (cu->cu_error.re_status = RPC_CANTRECV);
                }

                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;
                        if (fds != &readfds)
                                free(fds);
                        return (cu->cu_error.re_status = RPC_CANTRECV);
                }
                if (inlen < sizeof(u_int32_t))
                        continue;
#ifdef dont_check_xid
                /* see if reply transaction id matches sent id */
                if (*((u_int32_t *)(cu->cu_inbuf)) != *((u_int32_t *)(cu->cu_outbuf)))
                        continue;
#endif
                /* 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;
                                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)) {
                                nrefreshes--;
                                goto call_again;
                        }
                }  /* end of unsuccessful completion */
        }  /* end of valid reply message */
        else {
                cu->cu_error.re_status = RPC_CANTDECODERES;
        }
        if (fds != &readfds)
                free(fds);
        return (cu->cu_error.re_status);
}


/*
 * pmap_getport.c
 * Client interface to pmap rpc service.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */


static struct timeval timeout = { 1, 0 };
static struct timeval tottimeout = { 1, 0 };

/*
 * Find the mapped port for program,version.
 * Calls the pmap service remotely to do the lookup.
 * Returns 0 if no map exists.
 */
static u_short
__pmap_getport(struct sockaddr_in *address,
               u_long program, u_long version, u_int protocol)
{
        u_short port = 0;
        int sock = -1;
        CLIENT *client;
        struct pmap parms;

        address->sin_port = htons(PMAPPORT);

        client = clntudp_bufcreate(address, PMAPPROG,
            PMAPVERS, timeout, &sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE);
        if (client != (CLIENT *)NULL) {
                parms.pm_prog = program;
                parms.pm_vers = version;
                parms.pm_prot = protocol;
                parms.pm_port = 0;  /* not needed or used */
                if (CLNT_CALL(client, PMAPPROC_GETPORT, xdr_pmap, &parms,
                    xdr_u_short, &port, tottimeout) != RPC_SUCCESS){
                        rpc_createerr.cf_stat = RPC_PMAPFAILURE;
                        clnt_geterr(client, &rpc_createerr.cf_error);
                } else if (port == 0) {
                        rpc_createerr.cf_stat = RPC_PROGNOTREGISTERED;
                }
                CLNT_DESTROY(client);
        }
        if (sock != -1)
                close(sock);
        address->sin_port = 0;
        return (port);
}

/*
 * Transmit to YPPROC_DOMAIN_NONACK, return immediately.
 */
static bool_t *
ypproc_domain_nonack_2_send(domainname *argp, CLIENT *clnt)
{
        static bool_t clnt_res;
        struct timeval TIMEOUT = { 0, 0 };

        memset((char *)&clnt_res, 0, sizeof (clnt_res));
        if (clnt_call(clnt, YPPROC_DOMAIN_NONACK,
                (xdrproc_t) xdr_domainname, (caddr_t) argp,
                (xdrproc_t) xdr_bool, (caddr_t) &clnt_res,
                TIMEOUT) != RPC_SUCCESS) {
                return (NULL);
        }
        return (&clnt_res);
}

/*
 * Receive response from YPPROC_DOMAIN_NONACK asynchronously.
 */
static bool_t *
ypproc_domain_nonack_2_recv(domainname *argp, CLIENT *clnt)
{
        static bool_t clnt_res;
        struct timeval TIMEOUT = { 0, 0 };

        memset((char *)&clnt_res, 0, sizeof (clnt_res));
        if (clnt_call(clnt, YPPROC_DOMAIN_NONACK,
                (xdrproc_t) NULL, (caddr_t) argp,
                (xdrproc_t) xdr_bool, (caddr_t) &clnt_res,
                TIMEOUT) != RPC_SUCCESS) {
                return (NULL);
        }
        return (&clnt_res);
}

/*
 * "We have the machine that goes 'ping!'" -- Monty Python
 *
 * This function blasts packets at the YPPROC_DOMAIN_NONACK procedures
 * of the NIS servers listed in restricted_addrs structure.
 * Whoever replies the fastest becomes our chosen server.
 *
 * Note: THIS IS NOT A BROADCAST OPERATION! We could use clnt_broadcast()
 * for this, but that has the following problems:
 * - We only get the address of the machine that replied in the
 *   'eachresult' callback, and on multi-homed machines this can
 *   lead to confusion.
 * - clnt_broadcast() only transmits to local networks, whereas with
 *   NIS+ you can have a perfectly good server located anywhere on or
 *   off the local network.
 * - clnt_broadcast() blocks for an arbitrary amount of time which the
 *   caller can't control -- we want to avoid that.
 *
 * Also note that this has nothing to do with the NIS_PING procedure used
 * for replica updates.
 */

struct ping_req {
        struct sockaddr_in      sin;
        unsigned long           xid;
};

int
__yp_ping(struct in_addr *restricted_addrs, int cnt,
          char *dom, short int *port)
{
        struct timeval          tv = { 5, 0 };
        struct ping_req         **reqs;
        unsigned long           i;
        struct sockaddr_in      sin, *any = NULL;
        int                     winner = -1;
        time_t                  xid_seed, xid_lookup;
        int                     sock, dontblock = 1;
        CLIENT                  *clnt;
        char                    *foo = dom;
        struct cu_data          *cu;
        enum clnt_stat          (*oldfunc)();
        int                     validsrvs = 0;

        /* Set up handles. */
        reqs = calloc(1, sizeof(struct ping_req *) * cnt);
        xid_seed = time(NULL) ^ getpid();

        for (i = 0; i < cnt; i++) {
                bzero((char *)&sin, sizeof(sin));
                sin.sin_family = AF_INET;
                bcopy((char *)&restricted_addrs[i],
                        (char *)&sin.sin_addr, sizeof(struct in_addr));
                sin.sin_port = htons(__pmap_getport(&sin, YPPROG,
                                        YPVERS, IPPROTO_UDP));
                if (sin.sin_port == 0)
                        continue;
                reqs[i] = calloc(1, sizeof(struct ping_req));
                bcopy((char *)&sin, (char *)&reqs[i]->sin, sizeof(sin));
                any = &reqs[i]->sin;
                reqs[i]->xid = xid_seed;
                xid_seed++;
                validsrvs++;
        }

        /* Make sure at least one server was assigned */
        if (!validsrvs) {
                free(reqs);
                return(-1);
        }

        /* Create RPC handle */
        sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
        clnt = clntudp_create(any, YPPROG, YPVERS, tv, &sock);
        if (clnt == NULL) {
                close(sock);
                for (i = 0; i < cnt; i++)
                        if (reqs[i] != NULL)
                                free(reqs[i]);
                free(reqs);
                return(-1);
        }
        clnt->cl_auth = authunix_create_default();
        cu = (struct cu_data *)clnt->cl_private;
        tv.tv_sec = 0;
        clnt_control(clnt, CLSET_TIMEOUT, &tv);
        ioctl(sock, FIONBIO, &dontblock);
        oldfunc = clnt->cl_ops->cl_call;
        clnt->cl_ops->cl_call = clntudp_a_call;

        /* Transmit */
        for (i = 0; i < cnt; i++) {
                if (reqs[i] != NULL) {
                        /* subtract one; clntudp_call() will increment */
                        *((u_int32_t *)(cu->cu_outbuf)) = reqs[i]->xid - 1;
                        bcopy((char *)&reqs[i]->sin, (char *)&cu->cu_raddr,
                                sizeof(struct sockaddr_in));
                        ypproc_domain_nonack_2_send(&foo, clnt);
                }
        }

        /* Receive reply */
        ypproc_domain_nonack_2_recv(&foo, clnt);

        /* Got a winner -- look him up. */
        xid_lookup = *((u_int32_t *)(cu->cu_inbuf));
        for (i = 0; i < cnt; i++) {
                if (reqs[i] != NULL && reqs[i]->xid == xid_lookup) {
                        winner = i;
                        *port = reqs[i]->sin.sin_port;
                }
        }

        /* Shut everything down */
        clnt->cl_ops->cl_call = oldfunc;
        auth_destroy(clnt->cl_auth);
        clnt_destroy(clnt);
        close(sock);

        for (i = 0; i < cnt; i++)
                if (reqs[i] != NULL)
                        free(reqs[i]);
        free(reqs);

        return(winner);
}