/* @(#)clnt_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[] = "@(#)clnt_tcp.c 1.37 87/10/05 Copyr 1984 Sun Micro";
#endif

/*
 * clnt_tcp.c, Implements a TCP/IP based, client side RPC.
 *
 * TCP based RPC supports 'batched calls'.
 * A sequence of calls may be batched-up in a send buffer.  The rpc call
 * return immediately to the client even though the call was not necessarily
 * sent.  The batching occurs if the results' xdr routine is NULL (0) AND
 * the rpc timeout value is zero (see clnt.h, rpc).
 *
 * Clients should NOT casually batch calls that in fact return results; that is,
 * the server side should be aware that a call is batched and not produce any
 * return message.  Batched calls that produce many result messages can
 * deadlock (netlock) the client and the server....
 *
 * Now go hang yourself.
 */

#include <stdio.h>
#include <unistd.h>
#include <gssrpc/rpc.h>
#include <sys/socket.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <gssrpc/pmap_clnt.h>
/* FD_ZERO may need memset declaration (e.g., Solaris 9) */
#include <string.h>
#include <port-sockets.h>

#define MCALL_MSG_SIZE 24

#ifndef GETSOCKNAME_ARG3_TYPE
#define GETSOCKNAME_ARG3_TYPE int
#endif

static enum clnt_stat   clnttcp_call(CLIENT *, rpcproc_t, xdrproc_t, void *,
                                     xdrproc_t, void *, struct timeval);
static void             clnttcp_abort(CLIENT *);
static void             clnttcp_geterr(CLIENT *, struct rpc_err *);
static bool_t           clnttcp_freeres(CLIENT *, xdrproc_t, void *);
static bool_t           clnttcp_control(CLIENT *, int, void *);
static void             clnttcp_destroy(CLIENT *);

static struct clnt_ops tcp_ops = {
        clnttcp_call,
        clnttcp_abort,
        clnttcp_geterr,
        clnttcp_freeres,
        clnttcp_destroy,
        clnttcp_control
};

struct ct_data {
        int             ct_sock;
        bool_t          ct_closeit;
        struct timeval  ct_wait;
        bool_t          ct_waitset;       /* wait set by clnt_control? */
        struct sockaddr_in ct_addr;
        struct rpc_err  ct_error;
        union {
          char          ct_mcall[MCALL_MSG_SIZE];       /* marshalled callmsg */
          uint32_t   ct_mcalli;
        } ct_u;
        u_int           ct_mpos;                        /* pos after marshal */
        XDR             ct_xdrs;
};

static int      readtcp(char *, caddr_t, int);
static int      writetcp(char *, caddr_t, int);


/*
 * Create a client handle for a tcp/ip connection.
 * If *sockp<0, *sockp is set to a newly created TCP socket and it is
 * connected to raddr.  If *sockp non-negative then
 * raddr is ignored.  The rpc/tcp package does buffering
 * similar to stdio, so the client must pick send and receive buffer sizes,];
 * 0 => use the default.
 * If raddr->sin_port is 0, then a binder on the remote machine is
 * consulted for the right port number.
 * NB: *sockp is copied into a private area.
 * NB: It is the clients responsibility to close *sockp.
 * NB: The rpch->cl_auth is set null authentication.  Caller may wish to set this
 * something more useful.
 */
CLIENT *
clnttcp_create(
        struct sockaddr_in *raddr,
        rpcprog_t prog,
        rpcvers_t vers,
        SOCKET *sockp,
        u_int sendsz,
        u_int recvsz)
{
        CLIENT *h;
        struct ct_data *ct = 0;
        struct timeval now;
        struct rpc_msg call_msg;

        h  = (CLIENT *)mem_alloc(sizeof(*h));
        if (h == NULL) {
                (void)fprintf(stderr, "clnttcp_create: out of memory\n");
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                goto fooy;
        }
        ct = (struct ct_data *)mem_alloc(sizeof(*ct));
        if (ct == NULL) {
                (void)fprintf(stderr, "clnttcp_create: out of memory\n");
                rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                rpc_createerr.cf_error.re_errno = errno;
                goto fooy;
        }

        /*
         * If no port number given ask the pmap for one
         */
        if (raddr != NULL && raddr->sin_port == 0) {
                u_short port;
                if ((port = pmap_getport(raddr, prog, vers, IPPROTO_TCP)) == 0) {
                        mem_free((caddr_t)ct, sizeof(struct ct_data));
                        mem_free((caddr_t)h, sizeof(CLIENT));
                        return ((CLIENT *)NULL);
                }
                raddr->sin_port = htons(port);
        }

        /*
         * If no socket given, open one
         */
        if (*sockp < 0) {
                *sockp = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
                (void)bindresvport_sa(*sockp, NULL);
                if (*sockp < 0 || raddr == NULL ||
                    connect(*sockp, (struct sockaddr *)raddr,
                            sizeof(*raddr)) < 0) {
                        rpc_createerr.cf_stat = RPC_SYSTEMERROR;
                        rpc_createerr.cf_error.re_errno = errno;
                        (void)closesocket(*sockp);
                        goto fooy;
                }
                ct->ct_closeit = TRUE;
        } else {
                ct->ct_closeit = FALSE;
        }

        /*
         * Set up private data struct
         */
        ct->ct_sock = *sockp;
        ct->ct_wait.tv_usec = 0;
        ct->ct_waitset = FALSE;
        if (raddr == NULL) {
            /* Get the remote address from the socket, if it's IPv4. */
            struct sockaddr_in sin;
            socklen_t len = sizeof(sin);
            int ret = getpeername(ct->ct_sock, (struct sockaddr *)&sin, &len);
            if (ret == 0 && len == sizeof(sin) && sin.sin_family == AF_INET)
                ct->ct_addr = sin;
            else
                memset(&ct->ct_addr, 0, sizeof(ct->ct_addr));
        } else
            ct->ct_addr = *raddr;

        /*
         * Initialize call message
         */
        (void)gettimeofday(&now, (struct timezone *)0);
        call_msg.rm_xid = getpid() ^ now.tv_sec ^ now.tv_usec;
        call_msg.rm_direction = CALL;
        call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;
        call_msg.rm_call.cb_prog = prog;
        call_msg.rm_call.cb_vers = vers;

        /*
         * pre-serialize the staic part of the call msg and stash it away
         */
        xdrmem_create(&(ct->ct_xdrs), ct->ct_u.ct_mcall, MCALL_MSG_SIZE,
            XDR_ENCODE);
        if (! xdr_callhdr(&(ct->ct_xdrs), &call_msg)) {
                if (ct->ct_closeit)
                        (void)closesocket(*sockp);
                goto fooy;
        }
        ct->ct_mpos = XDR_GETPOS(&(ct->ct_xdrs));
        XDR_DESTROY(&(ct->ct_xdrs));

        /*
         * Create a client handle which uses xdrrec for serialization
         * and authnone for authentication.
         */
        xdrrec_create(&(ct->ct_xdrs), sendsz, recvsz,
            (caddr_t)ct, readtcp, writetcp);
        h->cl_ops = &tcp_ops;
        h->cl_private = (caddr_t) ct;
        h->cl_auth = authnone_create();
        return (h);

fooy:
        /*
         * Something goofed, free stuff and barf
         */
        mem_free((caddr_t)ct, sizeof(struct ct_data));
        mem_free((caddr_t)h, sizeof(CLIENT));
        return ((CLIENT *)NULL);
}

static enum clnt_stat
clnttcp_call(
        CLIENT *h,
        rpcproc_t proc,
        xdrproc_t xdr_args,
        void * args_ptr,
        xdrproc_t xdr_results,
        void * results_ptr,
        struct timeval timeout)
{
        struct ct_data *ct = h->cl_private;
        XDR *xdrs = &ct->ct_xdrs;
        struct rpc_msg reply_msg;
        uint32_t x_id;
        uint32_t *msg_x_id = &ct->ct_u.ct_mcalli;       /* yuk */
        bool_t shipnow;
        int refreshes = 2;
        long procl = proc;

        if (!ct->ct_waitset) {
                ct->ct_wait = timeout;
        }

        shipnow =
            (xdr_results == (xdrproc_t)0 && timeout.tv_sec == 0
            && timeout.tv_usec == 0) ? FALSE : TRUE;

call_again:
        xdrs->x_op = XDR_ENCODE;
        ct->ct_error.re_status = RPC_SUCCESS;
        x_id = ntohl(--(*msg_x_id));
        if ((! XDR_PUTBYTES(xdrs, ct->ct_u.ct_mcall, ct->ct_mpos)) ||
            (! XDR_PUTLONG(xdrs, &procl)) ||
            (! AUTH_MARSHALL(h->cl_auth, xdrs)) ||
            (! AUTH_WRAP(h->cl_auth, xdrs, xdr_args, args_ptr))) {
                if (ct->ct_error.re_status == RPC_SUCCESS)
                        ct->ct_error.re_status = RPC_CANTENCODEARGS;
                (void)xdrrec_endofrecord(xdrs, TRUE);
                return (ct->ct_error.re_status);
        }
        if (! xdrrec_endofrecord(xdrs, shipnow))
                return (ct->ct_error.re_status = RPC_CANTSEND);
        if (! shipnow)
                return (RPC_SUCCESS);
        /*
         * Hack to provide rpc-based message passing
         */
        if (timeout.tv_sec == 0 && timeout.tv_usec == 0) {
                return(ct->ct_error.re_status = RPC_TIMEDOUT);
        }


        /*
         * Keep receiving until we get a valid transaction id
         */
        xdrs->x_op = XDR_DECODE;
        while (TRUE) {
                reply_msg.acpted_rply.ar_verf = gssrpc__null_auth;
                reply_msg.acpted_rply.ar_results.where = NULL;
                reply_msg.acpted_rply.ar_results.proc = xdr_void;
                if (! xdrrec_skiprecord(xdrs))
                        return (ct->ct_error.re_status);
                /* now decode and validate the response header */
                if (! xdr_replymsg(xdrs, &reply_msg)) {
                        /*
                         * Free some stuff allocated by xdr_replymsg()
                         * to avoid leaks, since it may allocate
                         * memory from partially successful decodes.
                         */
                        enum xdr_op op = xdrs->x_op;
                        xdrs->x_op = XDR_FREE;
                        xdr_replymsg(xdrs, &reply_msg);
                        xdrs->x_op = op;
                        if (ct->ct_error.re_status == RPC_SUCCESS)
                                continue;
                        return (ct->ct_error.re_status);
                }
                if (reply_msg.rm_xid == x_id)
                        break;
        }

        /*
         * process header
         */
        gssrpc__seterr_reply(&reply_msg, &(ct->ct_error));
        if (ct->ct_error.re_status == RPC_SUCCESS) {
                if (! AUTH_VALIDATE(h->cl_auth, &reply_msg.acpted_rply.ar_verf)) {
                        ct->ct_error.re_status = RPC_AUTHERROR;
                        ct->ct_error.re_why = AUTH_INVALIDRESP;
                } else if (! AUTH_UNWRAP(h->cl_auth, xdrs,
                                         xdr_results, results_ptr)) {
                        if (ct->ct_error.re_status == RPC_SUCCESS)
                                ct->ct_error.re_status = RPC_CANTDECODERES;
                }
        }  /* end successful completion */
        else {
                /* maybe our credentials need to be refreshed ... */
                if (refreshes-- && AUTH_REFRESH(h->cl_auth, &reply_msg))
                        goto call_again;
        }  /* end of unsuccessful completion */
        /* free verifier ... */
        if ((reply_msg.rm_reply.rp_stat == MSG_ACCEPTED) &&
            (reply_msg.acpted_rply.ar_verf.oa_base != NULL)) {
            xdrs->x_op = XDR_FREE;
            (void)xdr_opaque_auth(xdrs, &(reply_msg.acpted_rply.ar_verf));
        }
        return (ct->ct_error.re_status);
}

static void
clnttcp_geterr(
        CLIENT *h,
        struct rpc_err *errp)
{
        struct ct_data *ct = h->cl_private;

        *errp = ct->ct_error;
}

static bool_t
clnttcp_freeres(
        CLIENT *cl,
        xdrproc_t xdr_res,
        void * res_ptr)
{
        struct ct_data *ct = cl->cl_private;
        XDR *xdrs = &ct->ct_xdrs;

        xdrs->x_op = XDR_FREE;
        return ((*xdr_res)(xdrs, res_ptr));
}

/*ARGSUSED*/
static void
clnttcp_abort(CLIENT *cl)
{
}

static bool_t
clnttcp_control(
        CLIENT *cl,
        int request,
        void *info)
{
        struct ct_data *ct = cl->cl_private;
        GETSOCKNAME_ARG3_TYPE len;

        switch (request) {
        case CLSET_TIMEOUT:
                ct->ct_wait = *(struct timeval *)info;
                ct->ct_waitset = TRUE;
                break;
        case CLGET_TIMEOUT:
                *(struct timeval *)info = ct->ct_wait;
                break;
        case CLGET_SERVER_ADDR:
                *(struct sockaddr_in *)info = ct->ct_addr;
                break;
        case CLGET_LOCAL_ADDR:
                len = sizeof(struct sockaddr);
                if (getsockname(ct->ct_sock, (struct sockaddr*)info, &len) < 0)
                     return FALSE;
                else
                     return TRUE;
        default:
                return (FALSE);
        }
        return (TRUE);
}


static void
clnttcp_destroy(CLIENT *h)
{
        struct ct_data *ct = h->cl_private;

        if (ct->ct_closeit)
                (void)closesocket(ct->ct_sock);
        XDR_DESTROY(&(ct->ct_xdrs));
        mem_free((caddr_t)ct, sizeof(struct ct_data));
        mem_free((caddr_t)h, sizeof(CLIENT));
}

/*
 * Interface between xdr serializer and tcp connection.
 * Behaves like the system calls, read & write, but keeps some error state
 * around for the rpc level.
 */
static int
readtcp(
        char *ctptr,
        caddr_t buf,
        int len)
{
  struct ct_data *ct = (void *)ctptr;
  struct timeval tout;
#ifdef FD_SETSIZE
        fd_set mask;
        fd_set readfds;

        if (len == 0)
                return (0);
        FD_ZERO(&mask);
        FD_SET(ct->ct_sock, &mask);
#else
        int mask = 1 << (ct->ct_sock);
        int readfds;

        if (len == 0)
                return (0);

#endif /* def FD_SETSIZE */
        while (TRUE) {
                readfds = mask;
                tout = ct->ct_wait;
                switch (select(gssrpc__rpc_dtablesize(), &readfds, (fd_set*)NULL, (fd_set*)NULL,
                               &tout)) {
                case 0:
                        ct->ct_error.re_status = RPC_TIMEDOUT;
                        return (-1);

                case -1:
                        if (errno == EINTR)
                                continue;
                        ct->ct_error.re_status = RPC_CANTRECV;
                        ct->ct_error.re_errno = errno;
                        return (-1);
                }
                break;
        }
        switch (len = read(ct->ct_sock, buf, (size_t) len)) {

        case 0:
                /* premature eof */
                ct->ct_error.re_errno = ECONNRESET;
                ct->ct_error.re_status = RPC_CANTRECV;
                len = -1;  /* it's really an error */
                break;

        case -1:
                ct->ct_error.re_errno = errno;
                ct->ct_error.re_status = RPC_CANTRECV;
                break;
        }
        return (len);
}

static int
writetcp(
        char *ctptr,
        caddr_t buf,
        int len)
{
        struct ct_data *ct = (struct ct_data *)(void *)ctptr;
        int i, cnt;

        for (cnt = len; cnt > 0; cnt -= i, buf += i) {
                if ((i = write(ct->ct_sock, buf, (size_t) cnt)) == -1) {
                        ct->ct_error.re_errno = errno;
                        ct->ct_error.re_status = RPC_CANTSEND;
                        return (-1);
                }
        }
        return (len);
}