libc/rpc/svc.c

/*
 * 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 *rcsid = "$OpenBSD: svc.c,v 1.14 2001/09/15 13:51:01 deraadt Exp $";
#endif /* LIBC_SCCS and not lint */

/*
 * 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 <stdlib.h>
#include <string.h>

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

static SVCXPRT **xports;
static int 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.
 */
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(u_long, u_long, struct svc_callout **);

int __svc_fdsetsize;
fd_set *__svc_fdset;

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

/*
 * Activate a transport handle.
 */
void
xprt_register(xprt)
	SVCXPRT *xprt;
{
	/* ignore failure conditions */
	(void) __xprt_register(xprt);
}

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

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

		fds = (fd_set *)malloc(bytes);
		if (fds == NULL)
			return (0);
		memset(fds, 0, bytes);
		if (__svc_fdset) {
			memcpy(fds, __svc_fdset, howmany(__svc_fdsetsize,
			    NFDBITS) * sizeof(fd_mask));
			free(__svc_fdset);
		}
		__svc_fdset = fds;
		__svc_fdsetsize = sock+1;
	}

	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 *));
		if (xp == NULL)
			return (0);
		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);
	return (1);
}

/*
 * De-activate a transport handle.
 */
void
xprt_unregister(xprt)
	SVCXPRT *xprt;
{
	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(xprt, prog, vers, dispatch, protocol)
	SVCXPRT *xprt;
	u_long prog;
	u_long vers;
	void (*dispatch)();
	int protocol;
{
	struct svc_callout *prev;
	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;
	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;
{
	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)
	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)
	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)
	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)
	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)
	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)
	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;
{
	fd_set readfds;

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

void	svc_getreqset2 __P((fd_set *, int));

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

void
svc_getreqset2(readfds, width)
	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;
	SVCXPRT *xprt;
	int bit;
	fd_mask mask, *maskp;
	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]);

	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);
	    }
	}
}