source: rtems/cpukit/librpc/src/rpc/rtems_portmapper.c @ 5220ae2

/*
 * 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
 */

#include <rpc/rpc.h>
#include <rpc/pmap_prot.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <malloc.h>
#include <netdb.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/wait.h>
#include <sys/signal.h>

static void reg_service();
static void callit();
static struct pmaplist *pmaplist;
static int debugging = 0;

#include <rtems.h>
#define fork()  (-1)


static rtems_task rtems_portmapper (rtems_task_argument unused)
{
        SVCXPRT *xprt;
        int sock;
        struct sockaddr_in addr;
        int len = sizeof(struct sockaddr_in);
        register struct pmaplist *pml;

        rtems_rpc_task_init ();
        if ((sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0) {
                perror("portmap cannot create socket");
                rtems_task_delete (RTEMS_SELF);
        }

        addr.sin_addr.s_addr = 0;
        addr.sin_family = AF_INET;
        addr.sin_port = htons(PMAPPORT);
        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                perror("portmap cannot bind");
                close (sock);
                rtems_task_delete (RTEMS_SELF);
        }

        if ((xprt = svcudp_create(sock)) == (SVCXPRT *)NULL) {
                fprintf(stderr, "couldn't do udp_create\n");
                close (sock);
                rtems_task_delete (RTEMS_SELF);
        }
        /* make an entry for ourself */
        pml = (struct pmaplist *)malloc(sizeof(struct pmaplist));
        pml->pml_next = 0;
        pml->pml_map.pm_prog = PMAPPROG;
        pml->pml_map.pm_vers = PMAPVERS;
        pml->pml_map.pm_prot = IPPROTO_UDP;
        pml->pml_map.pm_port = PMAPPORT;
        pmaplist = pml;

        if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
                perror("portmap cannot create socket");
                close (sock);
                rtems_task_delete (RTEMS_SELF);
        }
        if (bind(sock, (struct sockaddr *)&addr, len) != 0) {
                perror("portmap cannot bind");
                close (sock);
                rtems_task_delete (RTEMS_SELF);
        }
        if ((xprt = svctcp_create(sock, RPCSMALLMSGSIZE, RPCSMALLMSGSIZE))
            == (SVCXPRT *)NULL) {
                fprintf(stderr, "couldn't do tcp_create\n");
                close (sock);
                rtems_task_delete (RTEMS_SELF);
        }
        /* make an entry for ourself */
        pml = (struct pmaplist *)malloc(sizeof(struct pmaplist));
        pml->pml_map.pm_prog = PMAPPROG;
        pml->pml_map.pm_vers = PMAPVERS;
        pml->pml_map.pm_prot = IPPROTO_TCP;
        pml->pml_map.pm_port = PMAPPORT;
        pml->pml_next = pmaplist;
        pmaplist = pml;

        (void)svc_register(xprt, PMAPPROG, PMAPVERS, reg_service, FALSE);

        svc_run();
        fprintf(stderr, "run_svc returned unexpectedly\n");
        close (sock);
        rtems_task_delete (RTEMS_SELF);
}

static struct pmaplist *
find_service(
  u_long prog,
  u_long vers,
  int prot )
{
register struct pmaplist *hit = NULL;
register struct pmaplist *pml;

for (pml = pmaplist; pml != NULL; pml = pml->pml_next) {
        if ((pml->pml_map.pm_prog != prog) ||
                (pml->pml_map.pm_prot != prot))
                continue;
        hit = pml;
        if (pml->pml_map.pm_vers == vers)
            break;
}
        return (hit);
}

/* 
 * 1 OK, 0 not
 */
static void reg_service(
        struct svc_req *rqstp,
        SVCXPRT *xprt )
{
        struct pmap reg;
        struct pmaplist *pml, *prevpml, *fnd;
        int ans, port;
        caddr_t t;
        
#ifdef DEBUG
        fprintf(stderr, "server: about do a switch\n");
#endif
        switch (rqstp->rq_proc) {

        case PMAPPROC_NULL:
                /*
                 * Null proc call
                 */
                if ((!svc_sendreply(xprt, xdr_void, NULL)) && debugging) {
                        abort();
                }
                break;

        case PMAPPROC_SET:
                /*
                 * Set a program,version to port mapping
                 */
                if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        /*
                         * check to see if already used
                         * find_service returns a hit even if
                         * the versions don't match, so check for it
                         */
                        fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
                        if (fnd && fnd->pml_map.pm_vers == reg.pm_vers) {
                                if (fnd->pml_map.pm_port == reg.pm_port) {
                                        ans = 1;
                                        goto done;
                                }
                                else {
                                        ans = 0;
                                        goto done;
                                }
                        } else {
                                /* 
                                 * add to END of list
                                 */
                                pml = (struct pmaplist *)
                                    malloc(sizeof(struct pmaplist));
                                pml->pml_map = reg;
                                pml->pml_next = 0;
                                if (pmaplist == 0) {
                                        pmaplist = pml;
                                } else {
                                        for (fnd= pmaplist; fnd->pml_next != 0;
                                            fnd = fnd->pml_next);
                                        fnd->pml_next = pml;
                                }
                                ans = 1;
                        }
                done:
                        if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
                            debugging) {
                                fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_UNSET:
                /*
                 * Remove a program,version to port mapping.
                 */
                if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        ans = 0;
                        for (prevpml = NULL, pml = pmaplist; pml != NULL; ) {
                                if ((pml->pml_map.pm_prog != reg.pm_prog) ||
                                        (pml->pml_map.pm_vers != reg.pm_vers)) {
                                        /* both pml & prevpml move forwards */
                                        prevpml = pml;
                                        pml = pml->pml_next;
                                        continue;
                                }
                                /* found it; pml moves forward, prevpml stays */
                                ans = 1;
                                t = (caddr_t)pml;
                                pml = pml->pml_next;
                                if (prevpml == NULL)
                                        pmaplist = pml;
                                else
                                        prevpml->pml_next = pml;
                                free(t);
                        }
                        if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&ans)) &&
                            debugging) {
                                fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_GETPORT:
                /*
                 * Lookup the mapping for a program,version and return its port
                 */
                if (!svc_getargs(xprt, xdr_pmap, (caddr_t)&reg))
                        svcerr_decode(xprt);
                else {
                        fnd = find_service(reg.pm_prog, reg.pm_vers, reg.pm_prot);
                        if (fnd)
                                port = fnd->pml_map.pm_port;
                        else
                                port = 0;
                        if ((!svc_sendreply(xprt, xdr_long, (caddr_t)&port)) &&
                            debugging) {
                                fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_DUMP:
                /*
                 * Return the current set of mapped program,version
                 */
                if (!svc_getargs(xprt, xdr_void, NULL))
                        svcerr_decode(xprt);
                else {
                        if ((!svc_sendreply(xprt, xdr_pmaplist,
                            (caddr_t)&pmaplist)) && debugging) {
                                fprintf(stderr, "svc_sendreply\n");
                                abort();
                        }
                }
                break;

        case PMAPPROC_CALLIT:
                /*
                 * Calls a procedure on the local machine.  If the requested
                 * procedure is not registered this procedure does not return
                 * error information!!
                 * This procedure is only supported on rpc/udp and calls via 
                 * rpc/udp.  It passes null authentication parameters.
                 */
                callit(rqstp, xprt);
                break;

        default:
                svcerr_noproc(xprt);
                break;
        }
}


/*
 * Stuff for the rmtcall service
 */
#define ARGSIZE 9000

struct encap_parms {
        u_long arglen;
        char *args;
};

static bool_t
xdr_encap_parms(
        XDR *xdrs,
        struct encap_parms *epp )
{

        return (xdr_bytes(xdrs, &(epp->args), (u_int*)&(epp->arglen), ARGSIZE));
}

struct rmtcallargs {
        u_long  rmt_prog;
        u_long  rmt_vers;
        u_long  rmt_port;
        u_long  rmt_proc;
        struct encap_parms rmt_args;
};

static bool_t
xdr_rmtcall_args(
        register XDR *xdrs,
        register struct rmtcallargs *cap )
{

        /* does not get a port number */
        if (xdr_u_long(xdrs, &(cap->rmt_prog)) &&
            xdr_u_long(xdrs, &(cap->rmt_vers)) &&
            xdr_u_long(xdrs, &(cap->rmt_proc))) {
                return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
        }
        return (FALSE);
}

static bool_t
xdr_rmtcall_result(
        register XDR *xdrs,
        register struct rmtcallargs *cap )
{
        if (xdr_u_long(xdrs, &(cap->rmt_port)))
                return (xdr_encap_parms(xdrs, &(cap->rmt_args)));
        return (FALSE);
}

/*
 * only worries about the struct encap_parms part of struct rmtcallargs.
 * The arglen must already be set!!
 */
static bool_t
xdr_opaque_parms(
        XDR *xdrs,
        struct rmtcallargs *cap )
{

        return (xdr_opaque(xdrs, cap->rmt_args.args, cap->rmt_args.arglen));
}

/*
 * This routine finds and sets the length of incoming opaque paraters
 * and then calls xdr_opaque_parms.
 */
static bool_t
xdr_len_opaque_parms(
        register XDR *xdrs,
        struct rmtcallargs *cap )
{
        register u_int beginpos, lowpos, highpos, currpos, pos;

        beginpos = lowpos = pos = xdr_getpos(xdrs);
        highpos = lowpos + ARGSIZE;
        while ((int)(highpos - lowpos) >= 0) {
                currpos = (lowpos + highpos) / 2;
                if (xdr_setpos(xdrs, currpos)) {
                        pos = currpos;
                        lowpos = currpos + 1;
                } else {
                        highpos = currpos - 1;
                }
        }
        xdr_setpos(xdrs, beginpos);
        cap->rmt_args.arglen = pos - beginpos;
        return (xdr_opaque_parms(xdrs, cap));
}

/*
 * Call a remote procedure service
 * This procedure is very quiet when things go wrong.
 * The proc is written to support broadcast rpc.  In the broadcast case,
 * a machine should shut-up instead of complain, less the requestor be
 * overrun with complaints at the expense of not hearing a valid reply ...
 *
 * This now forks so that the program & process that it calls can call 
 * back to the portmapper.
 */
static void
callit(
        struct svc_req *rqstp,
        SVCXPRT *xprt )
{
        struct rmtcallargs a;
        struct pmaplist *pml;
        u_short port;
        struct sockaddr_in me;
        int pid, socket = -1;
        CLIENT *client;
        struct authunix_parms *au = (struct authunix_parms *)rqstp->rq_clntcred;
        struct timeval timeout;
        char buf[ARGSIZE];

        timeout.tv_sec = 5;
        timeout.tv_usec = 0;
        a.rmt_args.args = buf;
        if (!svc_getargs(xprt, xdr_rmtcall_args, (caddr_t)&a))
            return;
        if ((pml = find_service(a.rmt_prog, a.rmt_vers, IPPROTO_UDP)) == NULL)
            return;
        /*
         * fork a child to do the work.  Parent immediately returns.
         * Child exits upon completion.
         */
        if ((pid = fork()) != 0) {
                if (debugging && (pid < 0)) {
                        fprintf(stderr, "portmap CALLIT: cannot fork.\n");
                }
                return;
        }
        port = pml->pml_map.pm_port;
        get_myaddress(&me);
        me.sin_port = htons(port);
        client = clntudp_create(&me, a.rmt_prog, a.rmt_vers, timeout, &socket);
        if (client != (CLIENT *)NULL) {
                if (rqstp->rq_cred.oa_flavor == AUTH_UNIX) {
                        client->cl_auth = authunix_create(au->aup_machname,
                           au->aup_uid, au->aup_gid, au->aup_len, au->aup_gids);
                }
                a.rmt_port = (u_long)port;
                if (clnt_call(client, a.rmt_proc, xdr_opaque_parms, &a,
                    xdr_len_opaque_parms, &a, timeout) == RPC_SUCCESS) {
                        svc_sendreply(xprt, xdr_rmtcall_result, (caddr_t)&a);
                }
                AUTH_DESTROY(client->cl_auth);
                clnt_destroy(client);
        }
        (void)close(socket);
        exit(0);
}

/*
 * Start the RPC portmapper
 */
int rtems_rpc_start_portmapper (int priority)
{
        rtems_mode mode;
        rtems_status_code sc;
        rtems_id tid;
        static int started;

        rtems_task_mode (RTEMS_NO_PREEMPT, RTEMS_PREEMPT_MASK, &mode);
        if (started) {
                rtems_task_mode (mode, RTEMS_PREEMPT_MASK, &mode);
                return RTEMS_SUCCESSFUL;
        }
        sc = rtems_task_create (rtems_build_name('P', 'M', 'A', 'P'),
                priority,
                8000,
                RTEMS_PREEMPT|RTEMS_NO_TIMESLICE|RTEMS_NO_ASR|RTEMS_INTERRUPT_LEVEL(0),
                RTEMS_NO_FLOATING_POINT|RTEMS_LOCAL,
                &tid);
        if (sc != RTEMS_SUCCESSFUL) {
                rtems_task_mode (mode, RTEMS_PREEMPT_MASK, &mode);
                return sc;
        }
        sc = rtems_task_start (tid, rtems_portmapper, 0);
        if (sc != RTEMS_SUCCESSFUL) {
                rtems_task_mode (mode, RTEMS_PREEMPT_MASK, &mode);
                return sc;
        }
        started = 1;
        rtems_task_mode (mode, RTEMS_PREEMPT_MASK, &mode);
        return RTEMS_SUCCESSFUL;
}