source: rtems/cpukit/librpc/src/rpc/svc.c @ 624a038

/*
 * 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
 */

#if defined(LIBC_SCCS) && !defined(lint)
/*static char *sccsid = "from: @(#)svc.c 1.44 88/02/08 Copyr 1984 Sun Micro";*/
/*static char *sccsid = "from: @(#)svc.c        2.4 88/08/11 4.0 RPCSRC";*/
static char *rcsid = "$FreeBSD: src/lib/libc/rpc/svc.c,v 1.14 1999/08/28 00:00:48 peter Exp $";
#endif

/*
 * svc.c, Server-side remote procedure call interface.
 *
 * There are two sets of procedures here.  The xprt routines are
 * for handling transport handles.  The svc routines handle the
 * list of service routines.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

#include <string.h>
#include <stdlib.h>
#include <sys/errno.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>

#define xports (rtems_rpc_task_variables->svc_xports)
#define xportssize (rtems_rpc_task_variables->svc_xportssize)

#define NULL_SVC ((struct svc_callout *)0)
#define RQCRED_SIZE     400             /* this size is excessive */

#define max(a, b) (a > b ? a : b)

/*
 * The services list
 * Each entry represents a set of procedures (an rpc program).
 * The dispatch routine takes request structs and runs the
 * apropriate procedure.
 */
struct svc_callout {
        struct svc_callout *sc_next;
        u_long              sc_prog;
        u_long              sc_vers;
        void                (*sc_dispatch)(struct svc_req *r, SVCXPRT *xprt);
};
#define svc_head (rtems_rpc_task_variables->svc_svc_head)

static struct svc_callout *svc_find(u_long prog, u_long vers, 
  struct svc_callout **prev);

/* ***************  SVCXPRT related stuff **************** */

/*
 * Activate a transport handle.
 */
void
xprt_register(
        SVCXPRT *xprt )
{
        register int sock = xprt->xp_sock;

        if (sock + 1 > __svc_fdsetsize) {
                int bytes = sizeof (fd_set);
                fd_set *fds;

                fds = (fd_set *)malloc(bytes);
                memset(fds, 0, bytes);
                if (__svc_fdset) {
                        memcpy(fds, __svc_fdset, bytes);
                        free(__svc_fdset);
                }
                __svc_fdset = fds;
                __svc_fdsetsize = bytes * NBBY;
        }

        if (sock < FD_SETSIZE)
                FD_SET(sock, &svc_fdset);
        FD_SET(sock, __svc_fdset);

        if (xports == NULL || sock + 1 > xportssize) {
                SVCXPRT **xp;
                int size = FD_SETSIZE;

                if (sock + 1 > size)
                        size = sock + 1;
                xp = (SVCXPRT **)mem_alloc(size * sizeof(SVCXPRT *));
                memset(xp, 0, size * sizeof(SVCXPRT *));
                if (xports) {
                        memcpy(xp, xports, xportssize * sizeof(SVCXPRT *));
                        free(xports);
                }
                xportssize = size;
                xports = xp;
        }
        xports[sock] = xprt;
        svc_maxfd = max(svc_maxfd, sock);
}

/*
 * De-activate a transport handle.
 */
void
xprt_unregister(
        SVCXPRT *xprt )
{
        register int sock = xprt->xp_sock;

        if (xports[sock] == xprt) {
                xports[sock] = (SVCXPRT *)0;
                if (sock < FD_SETSIZE)
                        FD_CLR(sock, &svc_fdset);
                FD_CLR(sock, __svc_fdset);
                if (sock == svc_maxfd) {
                        for (svc_maxfd--; svc_maxfd >= 0; svc_maxfd--)
                                if (xports[svc_maxfd])
                                        break;
                }
                /*
                 * XXX could use svc_maxfd as a hint to
                 * decrease the size of __svc_fdset
                 */
        }
}


/* ********************** CALLOUT list related stuff ************* */

/*
 * Add a service program to the callout list.
 * The dispatch routine will be called when a rpc request for this
 * program number comes in.
 */
bool_t
svc_register(
        SVCXPRT *xprt,
        u_long prog,
        u_long vers,
        void (*dispatch)(struct svc_req *r, SVCXPRT *xprt),
        int protocol )
{
        struct svc_callout *prev;
        register struct svc_callout *s;

        if ((s = svc_find(prog, vers, &prev)) != NULL_SVC) {
                if (s->sc_dispatch == dispatch)
                        goto pmap_it;  /* he is registering another xptr */
                return (FALSE);
        }
        s = (struct svc_callout *)mem_alloc(sizeof(struct svc_callout));
        if (s == (struct svc_callout *)0) {
                return (FALSE);
        }
        s->sc_prog = prog;
        s->sc_vers = vers;
        s->sc_dispatch = dispatch;
        s->sc_next = svc_head;
        svc_head = s;
pmap_it:
        /* now register the information with the local binder service */
        if (protocol) {
                return (pmap_set(prog, vers, protocol, xprt->xp_port));
        }
        return (TRUE);
}

/*
 * Remove a service program from the callout list.
 */
void
svc_unregister(
        u_long prog,
        u_long vers )
{
        struct svc_callout *prev;
        register struct svc_callout *s;

        if ((s = svc_find(prog, vers, &prev)) == NULL_SVC)
                return;
        if (prev == NULL_SVC) {
                svc_head = s->sc_next;
        } else {
                prev->sc_next = s->sc_next;
        }
        s->sc_next = NULL_SVC;
        mem_free((char *) s, (u_int) sizeof(struct svc_callout));
        /* now unregister the information with the local binder service */
        (void)pmap_unset(prog, vers);
}

/*
 * Search the callout list for a program number, return the callout
 * struct.
 */
static struct svc_callout *
svc_find(
        u_long prog,
        u_long vers,
        struct svc_callout **prev )
{
        register struct svc_callout *s, *p;

        p = NULL_SVC;
        for (s = svc_head; s != NULL_SVC; s = s->sc_next) {
                if ((s->sc_prog == prog) && (s->sc_vers == vers))
                        goto done;
                p = s;
        }
done:
        *prev = p;
        return (s);
}

/* ******************* REPLY GENERATION ROUTINES  ************ */

/*
 * Send a reply to an rpc request
 */
bool_t
svc_sendreply(
        register SVCXPRT *xprt,
        xdrproc_t xdr_results,
        void *xdr_location )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = SUCCESS;
        rply.acpted_rply.ar_results.where = xdr_location;
        rply.acpted_rply.ar_results.proc = xdr_results;
        return (SVC_REPLY(xprt, &rply));
}

/*
 * No procedure error reply
 */
void
svcerr_noproc(
        register SVCXPRT *xprt )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = PROC_UNAVAIL;
        SVC_REPLY(xprt, &rply);
}

/*
 * Can't decode args error reply
 */
void
svcerr_decode(
        register SVCXPRT *xprt )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = GARBAGE_ARGS;
        SVC_REPLY(xprt, &rply);
}

/*
 * Some system error
 */
void
svcerr_systemerr(
        register SVCXPRT *xprt )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = SYSTEM_ERR;
        SVC_REPLY(xprt, &rply);
}

/*
 * Authentication error reply
 */
void
svcerr_auth(
        SVCXPRT *xprt,
        enum auth_stat why )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_DENIED;
        rply.rjcted_rply.rj_stat = AUTH_ERROR;
        rply.rjcted_rply.rj_why = why;
        SVC_REPLY(xprt, &rply);
}

/*
 * Auth too weak error reply
 */
void
svcerr_weakauth(
        SVCXPRT *xprt )
{

        svcerr_auth(xprt, AUTH_TOOWEAK);
}

/*
 * Program unavailable error reply
 */
void
svcerr_noprog(
        register SVCXPRT *xprt )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = PROG_UNAVAIL;
        SVC_REPLY(xprt, &rply);
}

/*
 * Program version mismatch error reply
 */
void
svcerr_progvers(
        register SVCXPRT *xprt,
        rpcvers_t low_vers,
        rpcvers_t high_vers )
{
        struct rpc_msg rply;

        rply.rm_direction = REPLY;
        rply.rm_reply.rp_stat = MSG_ACCEPTED;
        rply.acpted_rply.ar_verf = xprt->xp_verf;
        rply.acpted_rply.ar_stat = PROG_MISMATCH;
        rply.acpted_rply.ar_vers.low = low_vers;
        rply.acpted_rply.ar_vers.high = high_vers;
        SVC_REPLY(xprt, &rply);
}

/* ******************* SERVER INPUT STUFF ******************* */

/*
 * Get server side input from some transport.
 *
 * Statement of authentication parameters management:
 * This function owns and manages all authentication parameters, specifically
 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 * the "cooked" credentials (rqst->rq_clntcred).
 * However, this function does not know the structure of the cooked
 * credentials, so it make the following assumptions:
 *   a) the structure is contiguous (no pointers), and
 *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 * In all events, all three parameters are freed upon exit from this routine.
 * The storage is trivially management on the call stack in user land, but
 * is mallocated in kernel land.
 */

void
svc_getreq(
        int rdfds )
{
        fd_set readfds;

        FD_ZERO(&readfds);
        readfds.fds_bits[0] = rdfds;
        svc_getreqset(&readfds);
}

void
svc_getreqset(
        fd_set *readfds )
{
        svc_getreqset2(readfds, FD_SETSIZE);
}

void
svc_getreqset2(
        fd_set *readfds,
        int width )
{
        enum xprt_stat stat;
        struct rpc_msg msg;
        int prog_found;
        u_long low_vers;
        u_long high_vers;
        struct svc_req r;
        register SVCXPRT *xprt;
        register int bit;
        register int sock;
        register fd_mask mask, *maskp;
        char cred_area[2*MAX_AUTH_BYTES + RQCRED_SIZE];
        msg.rm_call.cb_cred.oa_base = cred_area;
        msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
        r.rq_clntcred = &(cred_area[2*MAX_AUTH_BYTES]);


        maskp = readfds->fds_bits;
        for (sock = 0; sock < width; sock += NFDBITS) {
            for (mask = *maskp++; (bit = ffs(mask)); mask ^= (1 << (bit - 1))) {
                /* sock has input waiting */
                xprt = xports[sock + bit - 1];
                if (xprt == NULL)
                        /* But do we control sock? */
                        continue;
                /* now receive msgs from xprtprt (support batch calls) */
                do {
                        if (SVC_RECV(xprt, &msg)) {

                                /* now find the exported program and call it */
                                register struct svc_callout *s;
                                enum auth_stat why;

                                r.rq_xprt = xprt;
                                r.rq_prog = msg.rm_call.cb_prog;
                                r.rq_vers = msg.rm_call.cb_vers;
                                r.rq_proc = msg.rm_call.cb_proc;
                                r.rq_cred = msg.rm_call.cb_cred;
                                /* first authenticate the message */
                                if ((why= _authenticate(&r, &msg)) != AUTH_OK) {
                                        svcerr_auth(xprt, why);
                                        goto call_done;
                                }
                                /* now match message with a registered service*/
                                prog_found = FALSE;
                                low_vers = (u_long) - 1;
                                high_vers = 0;
                                for (s = svc_head; s != NULL_SVC; s = s->sc_next) {
                                        if (s->sc_prog == r.rq_prog) {
                                                if (s->sc_vers == r.rq_vers) {
                                                        (*s->sc_dispatch)(&r, xprt);
                                                        goto call_done;
                                                }  /* found correct version */
                                                prog_found = TRUE;
                                                if (s->sc_vers < low_vers)
                                                        low_vers = s->sc_vers;
                                                if (s->sc_vers > high_vers)
                                                        high_vers = s->sc_vers;
                                        }   /* found correct program */
                                }
                                /*
                                 * if we got here, the program or version
                                 * is not served ...
                                 */
                                if (prog_found)
                                        svcerr_progvers(xprt,
                                        low_vers, high_vers);
                                else
                                         svcerr_noprog(xprt);
                                /* Fall through to ... */
                        }
                call_done:
                        if ((stat = SVC_STAT(xprt)) == XPRT_DIED){
                                SVC_DESTROY(xprt);
                                break;
                        }
                } while (stat == XPRT_MOREREQS);
            }
        }
}