glibc/sunrpc/svc_tcp.c

/* @(#)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 <rpc/rpc.h>
#include <sys/socket.h>
#include <errno.h>
#include <stdlib.h>

#ifdef USE_IN_LIBIO
# 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 const struct xp_ops svctcp_rendezvous_op =
{
  rendezvous_request,
  rendezvous_stat,
  (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) abort,
  (bool_t (*) (SVCXPRT *, struct rpc_msg *)) abort,
  (bool_t (*) (SVCXPRT *, xdrproc_t, caddr_t)) 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));
  if (r == NULL)
    {
      (void) fputs (_("svctcp_create: out of memory\n"), stderr);
      return NULL;
    }
  r->sendsize = sendsize;
  r->recvsize = recvsize;
  xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));
  if (xprt == NULL)
    {
      (void) fputs (_("svctcp_create: out of memory\n"), stderr);
      return NULL;
    }
  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));
  if (xprt == (SVCXPRT *) NULL)
    {
      (void) fputs (_("svc_tcp: makefd_xprt: out of memory\n"), stderr);
      goto done;
    }
  cd = (struct tcp_conn *) mem_alloc (sizeof (struct tcp_conn));
  if (cd == (struct tcp_conn *) NULL)
    {
      (void) fputs (_("svc_tcp: makefd_xprt: out of memory\n"), stderr);
      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_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);
done:
  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);
  xprt->xp_raddr = 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));
}

/*
 * 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.)
 *
 * Note: we have to be careful here not to allow ourselves to become
 * blocked too long in this routine.  While we're waiting for data from one
 * client, another client may be trying to connect.  To avoid this situation,
 * some code from svc_run() is transplanted here: the select() loop checks
 * all RPC descriptors including the one we want and calls svc_getreqset2()
 * to handle new requests if any are detected.
 */
static int
readtcp (char *xprtptr, char *buf, int len)
{
  SVCXPRT *xprt = (SVCXPRT *)xprtptr;
  int sock = xprt->xp_sock;
#ifdef FD_SETSIZE
  fd_set readfds;
#else
  int mask = 1 << sock;
  int readfds;
#endif /* def FD_SETSIZE */
  while (1)
    {
      struct timeval timeout = wait_per_try;
      readfds = svc_fdset;
#ifdef FD_SETSIZE
      FD_SET (sock, &readfds);
#else
      readfds |= (1 << sock);
#endif /* def FD_SETSIZE */
      if (__select (_rpc_dtablesize (), &readfds, (fd_set *) NULL,
		    (fd_set *) NULL, &timeout) <= 0)
	{
	  if (errno == EINTR)
	    continue;
	  goto fatal_err;
	}

#ifdef FD_SETSIZE
      if (FD_ISSET (sock, &readfds))
#else
      if (readfds == mask)
#endif /* def FD_SETSIZE */
	break;

      svc_getreqset (&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 (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 (xprt, msg)
     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 (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;
{
  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;
     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);
}