text: /* @(#)svc_tcp.c	2.2 88/08/01 4.0 RPCSRC */
  /*
   * 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(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.
   *
   * Copyright (C) 1984, Sun Microsystems, Inc.
   *
   * Actually implements two flavors of transporter -
   * a tcp rendezvouser (a listener and connection establisher)
   * and a record/tcp stream.
   */
  
  #include <stdio.h>
  #include <unistd.h>
  #include <string.h>
  #include <libintl.h>
  #include <rpc/rpc.h>
  #include <sys/socket.h>
  #include <sys/poll.h>
  #include <errno.h>
  #include <stdlib.h>
  
  #ifdef USE_IN_LIBIO
  # include <wchar.h>
  # include <libio/iolibio.h>
  # define fputs(s, f) _IO_fputs (s, f)
  #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, caddr_t);
  static bool_t svctcp_reply (SVCXPRT *, struct rpc_msg *);
  static bool_t svctcp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);
  static void svctcp_destroy (SVCXPRT *);
  
  static const 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 enum xprt_stat rendezvous_stat (SVCXPRT *);
  static void svctcp_rendezvous_abort (void);
  
  /* This function makes sure abort() relocation goes through PLT
     and thus can be lazy bound.  */
  static void
  svctcp_rendezvous_abort (void)
  {
    abort ();
  };
  
  static const struct xp_ops svctcp_rendezvous_op =
  {
    rendezvous_request,
    rendezvous_stat,
    (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
    (bool_t (*) (SVCXPRT *, struct rpc_msg *)) svctcp_rendezvous_abort,
    (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) svctcp_rendezvous_abort,
    svctcp_destroy
  };
  
  static int readtcp (char*, char *, int);
  static int writetcp (char *, char *, int);
  static SVCXPRT *makefd_xprt (int, u_int, u_int) internal_function;
  
  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;
      u_long 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 (int sock, u_int sendsize, u_int recvsize)
  {
    bool_t madesock = FALSE;
    SVCXPRT *xprt;
    struct tcp_rendezvous *r;
    struct sockaddr_in addr;
    socklen_t len = sizeof (struct sockaddr_in);
  
    if (sock == RPC_ANYSOCK)
      {
        if ((sock = __socket (AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
  	{
  	  perror (_("svc_tcp.c - tcp socket creation problem"));
  	  return (SVCXPRT *) NULL;
  	}
        madesock = TRUE;
      }
    __bzero ((char *) &addr, 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))
      {
        perror (_("svc_tcp.c - cannot getsockname or listen"));
        if (madesock)
  	(void) __close (sock);
        return (SVCXPRT *) NULL;
      }
    r = (struct tcp_rendezvous *) mem_alloc (sizeof (*r));
    xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
    if (r == NULL || xprt == NULL)
      {
  #ifdef USE_IN_LIBIO
        if (_IO_fwide (stderr, 0) > 0)
  	(void) __fwprintf (stderr, L"%s", _("svctcp_create: out of memory\n"));
        else
  #endif
  	(void) fputs (_("svctcp_create: out of memory\n"), stderr);
        mem_free (r, sizeof (*r));
        mem_free (xprt, sizeof (SVCXPRT));
        return NULL;
      }
    r->sendsize = sendsize;
    r->recvsize = recvsize;
    xprt->xp_p2 = NULL;
    xprt->xp_p1 = (caddr_t) r;
    xprt->xp_verf = _null_auth;
    xprt->xp_ops = &svctcp_rendezvous_op;
    xprt->xp_port = ntohs (addr.sin_port);
    xprt->xp_sock = sock;
    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 *
  internal_function
  makefd_xprt (int fd, u_int sendsize, u_int recvsize)
  {
    SVCXPRT *xprt;
    struct tcp_conn *cd;
  
    xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
    cd = (struct tcp_conn *) mem_alloc (sizeof (struct tcp_conn));
    if (xprt == (SVCXPRT *) NULL || cd == NULL)
      {
  #ifdef USE_IN_LIBIO
        if (_IO_fwide (stderr, 0) > 0)
  	(void) __fwprintf (stderr, L"%s",
  			   _("svc_tcp: makefd_xprt: out of memory\n"));
        else
  #endif
  	(void) fputs (_("svc_tcp: makefd_xprt: out of memory\n"), stderr);
        mem_free (xprt, sizeof (SVCXPRT));
        mem_free (cd, sizeof (struct tcp_conn));
        return NULL;
      }
    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_verf.oa_base = cd->verf_body;
    xprt->xp_addrlen = 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);
    return xprt;
  }
  
  static bool_t
  rendezvous_request (SVCXPRT *xprt, struct rpc_msg *errmsg)
  {
    int sock;
    struct tcp_rendezvous *r;
    struct sockaddr_in addr;
    socklen_t 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 (&xprt->xp_raddr, &addr, sizeof (addr));
    xprt->xp_addrlen = len;
    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 = (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));
    mem_free ((caddr_t) xprt, sizeof (SVCXPRT));
  }
  
  
  /*
   * 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, char *buf, int len)
  {
    SVCXPRT *xprt = (SVCXPRT *)xprtptr;
    int sock = xprt->xp_sock;
    int milliseconds = 35 * 1000;
    struct pollfd pollfd;
  
    do
      {
        pollfd.fd = sock;
        pollfd.events = POLLIN;
        switch (__poll (&pollfd, 1, milliseconds))
  	{
  	case -1:
  	  if (errno == EINTR)
  	    continue;
  	  /*FALLTHROUGH*/
  	case 0:
  	  goto fatal_err;
  	default:
            if ((pollfd.revents & POLLERR) || (pollfd.revents & POLLHUP)
                || (pollfd.revents & POLLNVAL))
              goto fatal_err;
  	  break;
  	}
      }
    while ((pollfd.revents & POLLIN) == 0);
  
    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 (char *xprtptr, char * buf, int len)
  {
    SVCXPRT *xprt = (SVCXPRT *)xprtptr;
    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 (SVCXPRT *xprt)
  {
    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 (SVCXPRT *xprt, struct rpc_msg *msg)
  {
    struct tcp_conn *cd = (struct tcp_conn *) (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;
      }
    cd->strm_stat = XPRT_DIED;	/* XXXX */
    return FALSE;
  }
  
  static bool_t
  svctcp_getargs (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 (SVCXPRT *xprt, xdrproc_t xdr_args, caddr_t 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 = (struct tcp_conn *) (xprt->xp_p1);
    XDR *xdrs = &(cd->xdrs);
    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;
  }
  