xref: /src/lib/libc/rpc/svc_generic.c

/*	$NetBSD: svc_generic.c,v 1.18 2024/01/23 17:24:38 christos Exp $	*/

/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of the "Oracle America, Inc." nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 THE
 *   COPYRIGHT HOLDER 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.
 */

/*
 * Copyright (c) 1986-1991 by Sun Microsystems Inc.
 */

/* #ident	"@(#)svc_generic.c	1.19	94/04/24 SMI" */

#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
#if 0
static char sccsid[] = "@(#)svc_generic.c 1.21 89/02/28 Copyr 1988 Sun Micro";
#else
__RCSID("$NetBSD: svc_generic.c,v 1.18 2024/01/23 17:24:38 christos Exp $");
#endif
#endif

/*
 * svc_generic.c, Server side for RPC.
 *
 */

#include "namespace.h"
#include "reentrant.h"
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <rpc/rpc.h>
#include <rpc/nettype.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>

#include "svc_fdset.h"
#include "rpc_internal.h"

#ifdef __weak_alias
__weak_alias(svc_create,_svc_create)
__weak_alias(svc_tp_create,_svc_tp_create)
__weak_alias(svc_tli_create,_svc_tli_create)
#endif

extern int __svc_vc_setflag(SVCXPRT *, int);

/*
 * The highest level interface for server creation.
 * It tries for all the nettokens in that particular class of token
 * and returns the number of handles it can create and/or find.
 *
 * It creates a link list of all the handles it could create.
 * If svc_create() is called multiple times, it uses the handle
 * created earlier instead of creating a new handle every time.
 */
int
svc_create(
	void (*dispatch)(struct svc_req *, SVCXPRT *),
	rpcprog_t prognum,		/* Program number */
	rpcvers_t versnum,		/* Version number */
	const char *nettype)		/* Networktype token */
{
	struct xlist {
		SVCXPRT *xprt;		/* Server handle */
		struct xlist *next;	/* Next item */
	} *l;
	static struct xlist *xprtlist;	/* A link list of all the handles */
	int num = 0;
	SVCXPRT *xprt;
	struct netconfig *nconf;
	void *handle;

/* VARIABLES PROTECTED BY xprtlist_lock: xprtlist */

	if ((handle = __rpc_setconf(nettype)) == NULL) {
		warnx("%s: unknown protocol %s", __func__, nettype);
		return (0);
	}
	while ((nconf = __rpc_getconf(handle)) != NULL) {
		mutex_lock(&xprtlist_lock);
		for (l = xprtlist; l; l = l->next) {
			if (strcmp(l->xprt->xp_netid, nconf->nc_netid) == 0) {
				/* Found an old one, use it */
				(void) rpcb_unset(prognum, versnum, nconf);
				if (svc_reg(l->xprt, prognum, versnum,
					dispatch, nconf) == FALSE)
					warnx("%s: could not register prog %u "
					    "vers %u on %s", __func__,
					    (unsigned)prognum,
					    (unsigned)versnum, nconf->nc_netid);
				else
					num++;
				break;
			}
		}
		if (l == NULL) {
			/* It was not found. Now create a new one */
			xprt = svc_tp_create(dispatch, prognum, versnum, nconf);
			if (xprt) {
				l = malloc(sizeof(*l));
				if (l == NULL) {
					warn("%s: out of memory", __func__);
					mutex_unlock(&xprtlist_lock);
					return (0);
				}
				l->xprt = xprt;
				l->next = xprtlist;
				xprtlist = l;
				num++;
			}
		}
		mutex_unlock(&xprtlist_lock);
	}
	__rpc_endconf(handle);
	/*
	 * In case of num == 0; the error messages are generated by the
	 * underlying layers; and hence not needed here.
	 */
	return (num);
}

/*
 * The high level interface to svc_tli_create().
 * It tries to create a server for "nconf" and registers the service
 * with the rpcbind. It calls svc_tli_create();
 */
SVCXPRT *
svc_tp_create(
	void (*dispatch)(struct svc_req *, SVCXPRT *),
	rpcprog_t prognum,		/* Program number */
	rpcvers_t versnum,		/* Version number */
	const struct netconfig *nconf) /* Netconfig structure for the network */
{
	SVCXPRT *xprt;

	if (nconf == NULL) {
		warnx("%s: invalid netconfig structure for prog %u vers %u",
		    __func__, (unsigned)prognum, (unsigned)versnum);
		return (NULL);
	}
	xprt = svc_tli_create(RPC_ANYFD, nconf, NULL, 0, 0);
	if (xprt == NULL) {
		return (NULL);
	}
	(void) rpcb_unset(prognum, versnum, __UNCONST(nconf));
	if (svc_reg(xprt, prognum, versnum, dispatch, nconf) == FALSE) {
		warnx("%s: Could not register prog %u vers %u on %s",
		    __func__, (unsigned)prognum, (unsigned)versnum,
		    nconf->nc_netid);
		SVC_DESTROY(xprt);
		return (NULL);
	}
	return (xprt);
}

/*
 * If fd is RPC_ANYFD, then it opens a fd for the given transport
 * provider (nconf cannot be NULL then). If the t_state is T_UNBND and
 * bindaddr is NON-NULL, it performs a t_bind using the bindaddr. For
 * NULL bindadr and Connection oriented transports, the value of qlen
 * is set to 8.
 *
 * If sendsz or recvsz are zero, their default values are chosen.
 */
SVCXPRT *
svc_tli_create(
	int fd,				/* Connection end point */
	const struct netconfig *nconf,	/* Netconfig struct for nettoken */
	const struct t_bind *bindaddr,	/* Local bind address */
	u_int sendsz,			/* Max sendsize */
	u_int recvsz)			/* Max recvsize */
{
	SVCXPRT *xprt = NULL;		/* service handle */
	bool_t madefd = FALSE;		/* whether fd opened here  */
	struct __rpc_sockinfo si;
	struct sockaddr_storage ss;
	socklen_t slen;

	if (fd == RPC_ANYFD) {
		if (nconf == NULL) {
			warnx("%s: invalid netconfig", __func__);
			return (NULL);
		}
		fd = __rpc_nconf2fd(nconf);
		if (fd == -1) {
			warnx("%s: could not open connection for %s", __func__,
			    nconf->nc_netid);
			return (NULL);
		}
		__rpc_nconf2sockinfo(nconf, &si);
		madefd = TRUE;
	} else {
		/*
		 * It is an open descriptor. Get the transport info.
		 */
		if (!__rpc_fd2sockinfo(fd, &si)) {
			warnx("%s: could not get transport information",
			    __func__);
			return (NULL);
		}
	}

	/*
	 * If the fd is unbound, try to bind it.
	 */
	if (madefd || !__rpc_sockisbound(fd)) {
		if (bindaddr == NULL) {
			if (bindresvport(fd, NULL) < 0) {
				memset(&ss, 0, sizeof ss);
				ss.ss_family = si.si_af;
				ss.ss_len = si.si_alen;
				if (bind(fd, (struct sockaddr *)(void *)&ss,
				    (socklen_t)si.si_alen) < 0) {
					warn( "%s: could not bind to anonymous "
					    "port", __func__);
					goto freedata;
				}
			}
			if (si.si_socktype != SOCK_DGRAM &&
			    listen(fd, SOMAXCONN) == -1) {
				warnx("%s: could not listen at anonymous port",
				    __func__);
				goto freedata;
			}
		} else {
			if (bind(fd,
			    (struct sockaddr *)bindaddr->addr.buf,
			    (socklen_t)si.si_alen) < 0) {
				warnx("%s: could not bind to requested address",
				    __func__);
				goto freedata;
			}
			if (si.si_socktype != SOCK_DGRAM &&
			    listen(fd, (int)bindaddr->qlen) == -1) {
				warnx("%s: could not listen at requested "
				    "address", __func__);
				goto freedata;
			}
		}
	}
	/*
	 * call transport specific function.
	 */
	switch (si.si_socktype) {
	case SOCK_STREAM:
		slen = sizeof ss;
		if (getpeername(fd, (struct sockaddr *)(void *)&ss, &slen)
		    == 0) {
			/* accepted socket */
			xprt = svc_fd_create(fd, sendsz, recvsz);
		} else
			xprt = svc_vc_create(fd, sendsz, recvsz);
		if (!nconf || !xprt)
			break;
#if 0
		/* XXX fvdl */
		if (strcmp(nconf->nc_protofmly, "inet") == 0 ||
		    strcmp(nconf->nc_protofmly, "inet6") == 0)
			(void) __svc_vc_setflag(xprt, TRUE);
#endif
		break;
	case SOCK_DGRAM:
		xprt = svc_dg_create(fd, sendsz, recvsz);
		break;
	default:
		warnx("%s: bad service type %u", __func__, si.si_socktype);
		goto freedata;
	}

	if (xprt == NULL)
		/*
		 * The error messages here are spitted out by the lower layers:
		 * svc_vc_create(), svc_fd_create() and svc_dg_create().
		 */
		goto freedata;

	/* Fill in type of service */
	xprt->xp_type = __rpc_socktype2seman(si.si_socktype);

	if (nconf) {
		xprt->xp_netid = strdup(nconf->nc_netid);
		xprt->xp_tp = strdup(nconf->nc_device);
		if (xprt->xp_netid == NULL || xprt->xp_tp == NULL) {
			svc_destroy(xprt);
			return NULL;
		}
	}
	return (xprt);

freedata:
	if (madefd)
		(void) close(fd);
	return (NULL);
}