/* @(#)svc.c	2.4 88/08/11 4.0 RPCSRC; from 1.44 88/02/08 SMI */
/*
 * 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
 */
#define __FORCE_GLIBC
#include <features.h>

/*
 * 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.
 */

#define __USE_XOPEN
#include <sys/errno.h>
#include <rpc/rpc.h>
#include <rpc/pmap_clnt.h>
#ifdef __linux__
#include <sys/types.h>
#include <sys/select.h>
#endif

extern int errno;

#ifdef FD_SETSIZE
static SVCXPRT **xports;
#else
#define NOFILE 32

static SVCXPRT *xports[NOFILE];
#endif							/* def FD_SETSIZE */

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

/*
 * The services list
 * Each entry represents a set of procedures (an rpc program).
 * The dispatch routine takes request structs and runs the
 * apropriate procedure.
 */
static struct svc_callout {
	struct svc_callout *sc_next;
	u_long sc_prog;
	u_long sc_vers;
	void (*sc_dispatch) ();
} *svc_head;

static struct svc_callout *svc_find();

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

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

#ifdef FD_SETSIZE
	if (xports == NULL) {
		xports = (SVCXPRT **)
			mem_alloc(FD_SETSIZE * sizeof(SVCXPRT *));
	}
	if (sock < _rpc_dtablesize()) {
		xports[sock] = xprt;
		FD_SET(sock, &svc_fdset);
	}
#else
	if (sock < NOFILE) {
		xports[sock] = xprt;
		svc_fds |= (1 << sock);
	}
#endif							/* def FD_SETSIZE */

}

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

#ifdef FD_SETSIZE
	if ((sock < _rpc_dtablesize()) && (xports[sock] == xprt)) {
		xports[sock] = (SVCXPRT *) 0;
		FD_CLR(sock, &svc_fdset);
	}
#else
	if ((sock < NOFILE) && (xports[sock] == xprt)) {
		xports[sock] = (SVCXPRT *) 0;
		svc_fds &= ~(1 << sock);
	}
#endif							/* def FD_SETSIZE */
}


/* ********************** 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, __dispatch_fn_t dispatch, u_long 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(prog, vers)
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(prog, vers, prev)
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(xprt, xdr_results, xdr_location)
register SVCXPRT *xprt;
xdrproc_t xdr_results;
caddr_t 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(xprt)
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(xprt)
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(xprt)
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(xprt, why)
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(xprt)
SVCXPRT *xprt;
{

	svcerr_auth(xprt, AUTH_TOOWEAK);
}

/*
 * Program unavailable error reply
 */
void svcerr_noprog(xprt)
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(xprt, low_vers, high_vers)
register SVCXPRT *xprt;
u_long low_vers;
u_long 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(rdfds)
int rdfds;
{
#ifdef FD_SETSIZE
	fd_set readfds;

	FD_ZERO(&readfds);
/*#ifdef __linux__*/
#if 0
	readfds = rdfds;
#else
	readfds.fds_bits[0] = rdfds;
#endif
	svc_getreqset(&readfds);
#else
	int readfds = rdfds & svc_fds;

	svc_getreqset(&readfds);
#endif							/* def FD_SETSIZE */
}

void svc_getreqset(readfds)
#ifdef FD_SETSIZE
fd_set *readfds;
{
#else
int *readfds;
{
	int readfds_local = *readfds;
#endif							/* def FD_SETSIZE */
	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 u_long mask;
	register int bit;
	register u_long *maskp;
	register int setsize;
	register int sock;
	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]);


#ifdef FD_SETSIZE
	setsize = _rpc_dtablesize();
#ifdef __linux__
/*#define NFDBITS	32*/
	maskp = (u_long *) readfds;
#else
	maskp = (u_long *) readfds->fds_bits;
#endif
	for (sock = 0; sock < setsize; sock += NFDBITS) {
		for (mask = *maskp++; (bit = ffs(mask)); mask ^= (1 << (bit - 1))) {
			/* sock has input waiting */
			xprt = xports[sock + bit - 1];
#else
	for (sock = 0; readfds_local != 0; sock++, readfds_local >>= 1) {
		if ((readfds_local & 1) != 0) {
			/* sock has input waiting */
			xprt = xports[sock];
#endif							/* def FD_SETSIZE */
			/* 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 = 0 - 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);
		}
	}
}
