/* @(#)svc_tcp.c        2.2 88/08/01 4.0 RPCSRC */
/*
 * Copyright (c) 2010, Oracle America, Inc.
 *
 * All rights reserved.
 *
 * 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.
 */
#if !defined(lint) && defined(SCCSIDS)
static char sccsid[] = "@(#)svc_tcp.c 1.21 87/08/11 Copyr 1984 Sun Micro";
#endif

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

#include "k5-platform.h"
#include <unistd.h>
#include <gssrpc/rpc.h>
#include <sys/socket.h>
#include <port-sockets.h>
#include <socket-utils.h>
/*extern bool_t abort();
extern errno;
*/

#ifndef FD_SETSIZE
#ifdef NBBY
#define NOFILE (sizeof(int) * NBBY)
#else
#define NOFILE (sizeof(int) * 8)
#endif
#endif

/*
 * Ops vector for TCP/IP based rpc service handle
 */
static bool_t           svctcp_recv(SVCXPRT *, struct rpc_msg *);
static enum xprt_stat   svctcp_stat(SVCXPRT *);
static bool_t           svctcp_getargs(SVCXPRT *, xdrproc_t, void *);
static bool_t           svctcp_reply(SVCXPRT *, struct rpc_msg *);
static bool_t           svctcp_freeargs(SVCXPRT *, xdrproc_t, void *);
static void             svctcp_destroy(SVCXPRT *);

static struct xp_ops svctcp_op = {
        svctcp_recv,
        svctcp_stat,
        svctcp_getargs,
        svctcp_reply,
        svctcp_freeargs,
        svctcp_destroy
};

/*
 * Ops vector for TCP/IP rendezvous handler
 */
static bool_t           rendezvous_request(SVCXPRT *, struct rpc_msg *);
static bool_t           abortx(void);
static bool_t           abortx_getargs(SVCXPRT *, xdrproc_t, void *);
static bool_t           abortx_reply(SVCXPRT *, struct rpc_msg *);
static bool_t           abortx_freeargs(SVCXPRT *, xdrproc_t, void *);
static enum xprt_stat   rendezvous_stat(SVCXPRT *);

static struct xp_ops svctcp_rendezvous_op = {
        rendezvous_request,
        rendezvous_stat,
        abortx_getargs,
        abortx_reply,
        abortx_freeargs,
        svctcp_destroy
};

static int readtcp(char *, caddr_t, int), writetcp(char *, caddr_t, int);
static SVCXPRT *makefd_xprt(int, u_int, u_int);

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(
        SOCKET sock,
        u_int sendsize,
        u_int recvsize)
{
        bool_t madesock = FALSE;
        SVCXPRT *xprt;
        struct tcp_rendezvous *r;
        struct sockaddr_storage ss;
        struct sockaddr *sa = (struct sockaddr *)&ss;
        socklen_t len;

        if (sock == RPC_ANYSOCK) {
                if ((sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) {
                        perror("svctcp_.c - udp socket creation problem");
                        return ((SVCXPRT *)NULL);
                }
                set_cloexec_fd(sock);
                madesock = TRUE;
                memset(&ss, 0, sizeof(ss));
                sa->sa_family = AF_INET;
        } else {
                len = sizeof(struct sockaddr_storage);
                if (getsockname(sock, sa, &len) != 0) {
                        perror("svc_tcp.c - cannot getsockname");
                        return ((SVCXPRT *)NULL);
                }
        }

        if (bindresvport_sa(sock, sa)) {
                sa_setport(sa, 0);
                (void)bind(sock, sa, sa_socklen(sa));
        }
        len = sizeof(struct sockaddr_storage);
        if (getsockname(sock, sa, &len) != 0) {
                perror("svc_tcp.c - cannot getsockname");
                if (madesock)
                        (void)closesocket(sock);
                return ((SVCXPRT *)NULL);
        }
        if (listen(sock, 2) != 0) {
                perror("svctcp_.c - cannot listen");
                if (madesock)
                        (void)closesocket(sock);
                return ((SVCXPRT *)NULL);
        }
        r = (struct tcp_rendezvous *)mem_alloc(sizeof(*r));
        if (r == NULL) {
                (void) fprintf(stderr, "svctcp_create: out of memory\n");
                return (NULL);
        }
        r->sendsize = sendsize;
        r->recvsize = recvsize;
        xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
        if (xprt == NULL) {
                (void) fprintf(stderr, "svctcp_create: out of memory\n");
                return (NULL);
        }
        xprt->xp_p2 = NULL;
        xprt->xp_p1 = (caddr_t)r;
        xprt->xp_auth = NULL;
        xprt->xp_verf = gssrpc__null_auth;
        xprt->xp_ops = &svctcp_rendezvous_op;
        xprt->xp_port = sa_getport(sa);
        xprt->xp_sock = sock;
        xprt->xp_laddrlen = 0;
        xprt_register(xprt);
        return (xprt);
}

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

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

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

#ifdef FD_SETSIZE
        if (fd >= FD_SETSIZE) {
                (void) fprintf(stderr, "svc_tcp: makefd_xprt: fd too high\n");
                xprt = NULL;
                goto done;
        }
#else
        if (fd >= NOFILE) {
                (void) fprintf(stderr, "svc_tcp: makefd_xprt: fd too high\n");
                xprt = NULL;
                goto done;
        }
#endif
        xprt = (SVCXPRT *)mem_alloc(sizeof(SVCXPRT));
        if (xprt == (SVCXPRT *)NULL) {
                (void) fprintf(stderr, "svc_tcp: makefd_xprt: out of memory\n");
                goto done;
        }
        cd = (struct tcp_conn *)mem_alloc(sizeof(struct tcp_conn));
        if (cd == (struct tcp_conn *)NULL) {
                (void) fprintf(stderr, "svc_tcp: makefd_xprt: out of memory\n");
                mem_free((char *) xprt, sizeof(SVCXPRT));
                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_p1 = (caddr_t)cd;
        xprt->xp_auth = NULL;
        xprt->xp_verf.oa_base = cd->verf_body;
        xprt->xp_addrlen = 0;
        xprt->xp_laddrlen = 0;
        xprt->xp_ops = &svctcp_op;  /* truly deals with calls */
        xprt->xp_port = 0;  /* this is a connection, not a rendezvouser */
        xprt->xp_sock = fd;
        xprt_register(xprt);
    done:
        return (xprt);
}

static bool_t
rendezvous_request(
        SVCXPRT *xprt,
        struct rpc_msg *msg)
{
        SOCKET sock;
        struct tcp_rendezvous *r;
        struct sockaddr_in addr, laddr;
        socklen_t len, llen;

        r = (struct tcp_rendezvous *)xprt->xp_p1;
    again:
        len = llen = sizeof(struct sockaddr_in);
        if ((sock = accept(xprt->xp_sock, (struct sockaddr *)&addr,
            &len)) < 0) {
                if (errno == EINTR)
                        goto again;
               return (FALSE);
        }
        set_cloexec_fd(sock);
        if (getsockname(sock, (struct sockaddr *) &laddr, &llen) < 0)
             return (FALSE);

        /*
         * make a new transporter (re-uses xprt)
         */
        xprt = makefd_xprt(sock, r->sendsize, r->recvsize);
        if (xprt == NULL) {
                (void)closesocket(sock);
                return (FALSE);
        }
        xprt->xp_raddr = addr;
        xprt->xp_addrlen = len;
        xprt->xp_laddr = laddr;
        xprt->xp_laddrlen = llen;
        return (FALSE); /* there is never an rpc msg to be processed */
}

static enum xprt_stat
rendezvous_stat(SVCXPRT *xprt)
{

        return (XPRT_IDLE);
}

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

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

/*
 * 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 connection.
 * any error is fatal and the connection is closed.
 * (And a read of zero bytes is a half closed stream => error.)
 */
static int
readtcp(
        char *xprtptr,
        caddr_t buf,
        int len)
{
        SVCXPRT *xprt = (void *)xprtptr;
        int sock = xprt->xp_sock;
        struct timeval tout;
#ifdef FD_SETSIZE
        fd_set mask;
        fd_set readfds;

        FD_ZERO(&mask);
        FD_SET(sock, &mask);
#else
        int mask = 1 << sock;
        int readfds;
#endif /* def FD_SETSIZE */
#ifdef FD_SETSIZE
#define loopcond (!FD_ISSET(sock, &readfds))
#else
#define loopcond (readfds != mask)
#endif
        do {
                readfds = mask;
                tout = wait_per_try;
                if (select(sock + 1, &readfds, (fd_set*)NULL,
                           (fd_set*)NULL, &tout) <= 0) {
                        if (errno == EINTR) {
                                continue;
                        }
                        goto fatal_err;
                }
        } while (loopcond);
        if ((len = read(sock, buf, (size_t) 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(
        char *xprtptr,
        caddr_t buf,
        int len)
{
        SVCXPRT *xprt = (void *)xprtptr;
        int i, cnt;

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

static enum xprt_stat
svctcp_stat(SVCXPRT *xprt)
{
        struct tcp_conn *cd = 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(
        SVCXPRT *xprt,
        struct rpc_msg *msg)
{
        struct tcp_conn *cd = xprt->xp_p1;
        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(
        SVCXPRT *xprt,
        xdrproc_t xdr_args,
        void *args_ptr)
{
        if (! SVCAUTH_UNWRAP(xprt->xp_auth,
                             &(((struct tcp_conn *)(xprt->xp_p1))->xdrs),
                             xdr_args, args_ptr)) {
                (void)svctcp_freeargs(xprt, xdr_args, args_ptr);
                return FALSE;
        }
        return TRUE;
}

static bool_t
svctcp_freeargs(
        SVCXPRT *xprt,
        xdrproc_t xdr_args,
        void * args_ptr)
{
        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(
        SVCXPRT *xprt,
        struct rpc_msg *msg)
{
        struct tcp_conn *cd = xprt->xp_p1;
        XDR *xdrs = &cd->xdrs;
        bool_t stat;

        xdrproc_t xdr_results = NULL;
        caddr_t xdr_location = 0;
        bool_t has_args;

        if (msg->rm_reply.rp_stat == MSG_ACCEPTED &&
            msg->rm_reply.rp_acpt.ar_stat == SUCCESS) {
                has_args = TRUE;
                xdr_results = msg->acpted_rply.ar_results.proc;
                xdr_location = msg->acpted_rply.ar_results.where;

                msg->acpted_rply.ar_results.proc = xdr_void;
                msg->acpted_rply.ar_results.where = NULL;
        } else
                has_args = FALSE;

        xdrs->x_op = XDR_ENCODE;
        msg->rm_xid = cd->x_id;
        stat = FALSE;
        if (xdr_replymsg(xdrs, msg) &&
            (!has_args ||
             (SVCAUTH_WRAP(xprt->xp_auth, xdrs, xdr_results, xdr_location)))) {
                stat = TRUE;
        }
        (void)xdrrec_endofrecord(xdrs, TRUE);
        return (stat);
}

static bool_t abortx(void)
{
        abort();
        return 1;
}

static bool_t abortx_getargs(
        SVCXPRT *xprt,
        xdrproc_t proc,
        void *info)
{
        return abortx();
}

static bool_t abortx_reply(SVCXPRT *xprt, struct rpc_msg *msg)
{
        return abortx();
}

static bool_t abortx_freeargs(
        SVCXPRT *xprt, xdrproc_t proc,
        void * info)
{
        return abortx();
}