/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

/*
 * svc_tcp.c, Server side for TCP/IP based RPC.
 *
 * Actually implements two flavors of transporter -
 * a tcp rendezvouser (a listner and connection establisher)
 * and a record/tcp stream.
 */

#include <rpc/rpc.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <errno.h>
#include <syslog.h>
#include <malloc.h>
#include <stdio.h>

extern bool_t abort();
extern int errno;
extern SVCXPRT *svc_xprt_alloc();
extern void svc_xprt_free();
extern int _socket(int, int, int);
extern int _bind(int, const struct sockaddr *, int);
extern int _getsockname(int, struct sockaddr *, int *);
extern int _listen(int, int);
extern int _accept(int, struct sockaddr *, int *);
extern int bindresvport(int, struct sockaddr_in *);

static struct xp_ops *svctcp_ops();
static struct xp_ops *svctcp_rendezvous_ops();

static int readtcp(), writetcp();
static SVCXPRT *makefd_xprt();

struct tcp_rendezvous { /* kept in xprt->xp_p1 */
        u_int sendsize;
        u_int recvsize;
};

struct tcp_conn {  /* kept in xprt->xp_p1 */
        enum xprt_stat strm_stat;
        uint32_t x_id;
        XDR xdrs;
        char verf_body[MAX_AUTH_BYTES];
};

/*
 * Usage:
 *      xprt = svctcp_create(sock, send_buf_size, recv_buf_size);
 *
 * Creates, registers, and returns a (rpc) tcp based transporter.
 * Once *xprt is initialized, it is registered as a transporter
 * see (svc.h, xprt_register).  This routine returns
 * a NULL if a problem occurred.
 *
 * If sock<0 then a socket is created, else sock is used.
 * If the socket, sock is not bound to a port then svctcp_create
 * binds it to an arbitrary port.  The routine then starts a tcp
 * listener on the socket's associated port.  In any (successful) case,
 * xprt->xp_sock is the registered socket number and xprt->xp_port is the
 * associated port number.
 *
 * Since tcp streams do buffered io similar to stdio, the caller can specify
 * how big the send and receive buffers are via the second and third parms;
 * 0 => use the system default.
 */
SVCXPRT *
svctcp_create(sock, sendsize, recvsize)
        register int sock;
        u_int sendsize;
        u_int recvsize;
{
        bool_t madesock = FALSE;
        register SVCXPRT *xprt;
        register struct tcp_rendezvous *r;
        struct sockaddr_in addr;
        int len = sizeof (struct sockaddr_in);

        if (sock == RPC_ANYSOCK) {
                if ((sock = _socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
                        (void) syslog(LOG_ERR, "svctcp_create - tcp",
                                " socket creation problem: %m");
                        return ((SVCXPRT *)NULL);
                }
                madesock = TRUE;
        }
        memset((char *)&addr, 0, sizeof (addr));
        addr.sin_family = AF_INET;
        if (bindresvport(sock, &addr)) {
                addr.sin_port = 0;
                (void) _bind(sock, (struct sockaddr *)&addr, len);
        }
        if ((_getsockname(sock, (struct sockaddr *)&addr, &len) != 0) ||
            (_listen(sock, 2) != 0)) {
                (void) syslog(LOG_ERR, "svctcp_create - cannot",
                        " getsockname or listen: %m");
                if (madesock)
                        (void) close(sock);
                return ((SVCXPRT *)NULL);
        }
        r = (struct tcp_rendezvous *)mem_alloc(sizeof (*r));
        if (r == NULL) {
                (void) syslog(LOG_ERR, "svctcp_create: out of memory");
                if (madesock)
                        (void) close(sock);
                return (NULL);
        }
        r->sendsize = sendsize;
        r->recvsize = recvsize;
        xprt = svc_xprt_alloc();
        if (xprt == NULL) {
                (void) syslog(LOG_ERR, "svctcp_create: out of memory");
                mem_free((char *) r, sizeof (*r));
                if (madesock)
                        (void) close(sock);
                return (NULL);
        }
        xprt->xp_p2 = NULL;
        xprt->xp_netid = NULL;
        xprt->xp_p1 = (caddr_t)r;
        xprt->xp_verf = _null_auth;
        xprt->xp_ops = svctcp_rendezvous_ops();
        xprt->xp_port = ntohs(addr.sin_port);
        xprt->xp_sock = sock;
        xprt->xp_rtaddr.buf = xprt->xp_raddr;
        xprt_register(xprt);
        return (xprt);
}

/*
 * Like svtcp_create(), except the routine takes any *open* UNIX file
 * descriptor as its first input.
 */
SVCXPRT *
svcfd_create(fd, sendsize, recvsize)
        int fd;
        u_int sendsize;
        u_int recvsize;
{

        return (makefd_xprt(fd, sendsize, recvsize));
}

static SVCXPRT *
makefd_xprt(fd, sendsize, recvsize)
        int fd;
        u_int sendsize;
        u_int recvsize;
{
        register SVCXPRT *xprt;
        register struct tcp_conn *cd;

        xprt = svc_xprt_alloc();
        if (xprt == (SVCXPRT *)NULL) {
                (void) syslog(LOG_ERR, "svc_tcp: makefd_xprt: out of memory");
                goto done;
        }
        cd = (struct tcp_conn *)mem_alloc(sizeof (struct tcp_conn));
        if (cd == (struct tcp_conn *)NULL) {
                (void) syslog(LOG_ERR, "svc_tcp: makefd_xprt: out of memory");
                svc_xprt_free(xprt);
                xprt = (SVCXPRT *)NULL;
                goto done;
        }
        cd->strm_stat = XPRT_IDLE;
        xdrrec_create(&(cd->xdrs), sendsize, recvsize,
            (caddr_t)xprt, readtcp, writetcp);
        xprt->xp_p2 = NULL;
        xprt->xp_netid = NULL;
        xprt->xp_p1 = (caddr_t)cd;
        xprt->xp_verf.oa_base = cd->verf_body;
        xprt->xp_addrlen = 0;
        xprt->xp_ops = svctcp_ops();  /* truely deals with calls */
        xprt->xp_port = 0;  /* this is a connection, not a rendezvouser */
        xprt->xp_sock = fd;
        /* to handle svc_getcaller() properly */
        xprt->xp_rtaddr.buf = xprt->xp_raddr;
        xprt_register(xprt);
        done:
        return (xprt);
}

static bool_t
rendezvous_request(xprt, rpc_msg)
        register SVCXPRT *xprt;
        struct rpc_msg  *rpc_msg;
{
        int sock;
        struct tcp_rendezvous *r;
        struct sockaddr_in addr;
        int len;

        r = (struct tcp_rendezvous *)xprt->xp_p1;
        again:
        len = sizeof (struct sockaddr_in);
        if ((sock = _accept(xprt->xp_sock, (struct sockaddr *)&addr,
            &len)) < 0) {
                if (errno == EINTR)
                        goto again;
                return (FALSE);
        }
        /*
         * make a new transporter (re-uses xprt)
         */
        xprt = makefd_xprt(sock, r->sendsize, r->recvsize);

        memcpy((char *)&xprt->xp_raddr, (char *)&addr, len);
        xprt->xp_addrlen = len;
        return (FALSE); /* there is never an rpc msg to be processed */
}

static enum xprt_stat
rendezvous_stat(xprt)
        SVCXPRT *xprt;
{

        return (XPRT_IDLE);
}

static void
svctcp_destroy(xprt)
        register SVCXPRT *xprt;
{
        register struct tcp_conn *cd = (struct tcp_conn *)xprt->xp_p1;

        xprt_unregister(xprt);
        (void) close(xprt->xp_sock);
        if (xprt->xp_port != 0) {
                /* a rendezvouser socket */
                xprt->xp_port = 0;
        } else {
                /* an actual connection socket */
                XDR_DESTROY(&(cd->xdrs));
        }
        mem_free((caddr_t)cd, sizeof (struct tcp_conn));
        svc_xprt_free(xprt);
}

/*
 * All read operations timeout after 35 seconds.
 * A timeout is fatal for the connection.
 */
static struct timeval wait_per_try = { 35, 0 };

/*
 * reads data from the tcp conection.
 * any error is fatal and the connection is closed.
 * (And a read of zero bytes is a half closed stream => error.)
 */
static int
readtcp(xprt, buf, len)
        register SVCXPRT *xprt;
        caddr_t buf;
        register int len;
{
        register int sock = xprt->xp_sock;
        fd_set mask;
        fd_set readfds;

        FD_ZERO(&mask);
        FD_SET(sock, &mask);
        do {
                readfds = mask;
                if (select(__rpc_dtbsize(), &readfds, NULL, NULL,
                        &wait_per_try) <= 0) {
                        if (errno == EINTR) {
                                continue;
                        }
                        goto fatal_err;
                }
        } while (!FD_ISSET(sock, &readfds));
        if ((len = read(sock, buf, len)) > 0) {
                return (len);
        }
fatal_err:
        ((struct tcp_conn *)(xprt->xp_p1))->strm_stat = XPRT_DIED;
        return (-1);
}

/*
 * writes data to the tcp connection.
 * Any error is fatal and the connection is closed.
 */
static int
writetcp(xprt, buf, len)
        register SVCXPRT *xprt;
        caddr_t buf;
        int len;
{
        register int i, cnt;

        for (cnt = len; cnt > 0; cnt -= i, buf += i) {
                if ((i = write(xprt->xp_sock, buf, cnt)) < 0) {
                        ((struct tcp_conn *)(xprt->xp_p1))->strm_stat =
                            XPRT_DIED;
                        return (-1);
                }
        }
        return (len);
}

static enum xprt_stat
svctcp_stat(xprt)
        SVCXPRT *xprt;
{
        register struct tcp_conn *cd =
            (struct tcp_conn *)(xprt->xp_p1);

        if (cd->strm_stat == XPRT_DIED)
                return (XPRT_DIED);
        if (! xdrrec_eof(&(cd->xdrs)))
                return (XPRT_MOREREQS);
        return (XPRT_IDLE);
}

static bool_t
svctcp_recv(xprt, msg)
        SVCXPRT *xprt;
        register struct rpc_msg *msg;
{
        register struct tcp_conn *cd =
            (struct tcp_conn *)(xprt->xp_p1);
        register XDR *xdrs = &(cd->xdrs);

        xdrs->x_op = XDR_DECODE;
        (void) xdrrec_skiprecord(xdrs);
        if (xdr_callmsg(xdrs, msg)) {
                cd->x_id = msg->rm_xid;
                return (TRUE);
        }
        return (FALSE);
}

static bool_t
svctcp_getargs(xprt, xdr_args, args_ptr)
        SVCXPRT *xprt;
        xdrproc_t xdr_args;
        caddr_t args_ptr;
{

        return ((*xdr_args)(&(((struct tcp_conn *)(xprt->xp_p1))->xdrs),
                args_ptr));
}

static bool_t
svctcp_freeargs(xprt, xdr_args, args_ptr)
        SVCXPRT *xprt;
        xdrproc_t xdr_args;
        caddr_t args_ptr;
{
        register XDR *xdrs =
            &(((struct tcp_conn *)(xprt->xp_p1))->xdrs);

        xdrs->x_op = XDR_FREE;
        return ((*xdr_args)(xdrs, args_ptr));
}

static bool_t
svctcp_reply(xprt, msg)
        SVCXPRT *xprt;
        register struct rpc_msg *msg;
{
        register struct tcp_conn *cd =
            (struct tcp_conn *)(xprt->xp_p1);
        register XDR *xdrs = &(cd->xdrs);
        register bool_t stat;

        xdrs->x_op = XDR_ENCODE;
        msg->rm_xid = cd->x_id;
        stat = xdr_replymsg(xdrs, msg);
        (void) xdrrec_endofrecord(xdrs, TRUE);
        return (stat);
}


static struct xp_ops *
svctcp_ops()
{
        static struct xp_ops ops;

        if (ops.xp_recv == NULL) {
                ops.xp_recv = svctcp_recv;
                ops.xp_stat = svctcp_stat;
                ops.xp_getargs = svctcp_getargs;
                ops.xp_reply = svctcp_reply;
                ops.xp_freeargs = svctcp_freeargs;
                ops.xp_destroy = svctcp_destroy;
        }
        return (&ops);
}


static struct xp_ops *
svctcp_rendezvous_ops()
{
        static struct xp_ops ops;

        if (ops.xp_recv == NULL) {
                ops.xp_recv = rendezvous_request;
                ops.xp_stat = rendezvous_stat;
                ops.xp_getargs = abort;
                ops.xp_reply = abort;
                ops.xp_freeargs = abort,
                ops.xp_destroy = svctcp_destroy;
        }
        return (&ops);
}