/* @(#)svc.c	2.4 88/08/11 4.0 RPCSRC; from 1.44 88/02/08 SMI */
/*
 * 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.c 1.41 87/10/13 Copyr 1984 Sun Micro";
#endif

/*
 * svc.c, Server-side remote procedure call interface.
 *
 * There are two sets of procedures here.  The xprt routines are
 * for handling transport handles.  The svc routines handle the
 * list of service routines.
 *
 * Copyright (C) 1984, Sun Microsystems, Inc.
 */

#include <errno.h>
#include <rpc/rpc.h>
#include <rpc/svc.h>
#include <rpc/pmap_clnt.h>

#ifndef errno
extern int errno;
#endif

#ifdef FD_SETSIZE
static SVCXPRT **xports;
#else
#define NOFILE 32

static SVCXPRT *xports[NOFILE];
#endif /* def FD_SETSIZE */

#define NULL_SVC ((struct svc_callout *)0)
#define	RQCRED_SIZE	400	/* this size is excessive */

/*
 * The services list
 * Each entry represents a set of procedures (an rpc program).
 * The dispatch routine takes request structs and runs the
 * appropriate procedure.
 */
static struct svc_callout
  {
    struct svc_callout *sc_next;
    u_long sc_prog;
    u_long sc_vers;
    void (*sc_dispatch) (struct svc_req *, SVCXPRT *);
  }
 *svc_head;

static struct svc_callout *svc_find (u_long, u_long, struct svc_callout **);

/* ***************  SVCXPRT related stuff **************** */

/*
 * Activate a transport handle.
 */
void
xprt_register (SVCXPRT *xprt)
{
  register int sock = xprt->xp_sock;

#ifdef FD_SETSIZE
  if (xports == NULL)
    {
      xports = (SVCXPRT **)
	mem_alloc (FD_SETSIZE * sizeof (SVCXPRT *));
    }
  if (sock < _rpc_dtablesize ())
    {
      xports[sock] = xprt;
      FD_SET (sock, &svc_fdset);
    }
#else
  if (sock < NOFILE)
    {
      xports[sock] = xprt;
      svc_fds |= (1 << sock);
    }
#endif /* def FD_SETSIZE */

}

/*
 * De-activate a transport handle.
 */
void
xprt_unregister (xprt)
     SVCXPRT *xprt;
{
  register int sock = xprt->xp_sock;

#ifdef FD_SETSIZE
  if ((sock < _rpc_dtablesize ()) && (xports[sock] == xprt))
    {
      xports[sock] = (SVCXPRT *) 0;
      FD_CLR (sock, &svc_fdset);
    }
#else
  if ((sock < NOFILE) && (xports[sock] == xprt))
    {
      xports[sock] = (SVCXPRT *) 0;
      svc_fds &= ~(1 << sock);
    }
#endif /* def FD_SETSIZE */
}


/* ********************** CALLOUT list related stuff ************* */

/*
 * Add a service program to the callout list.
 * The dispatch routine will be called when a rpc request for this
 * program number comes in.
 */
bool_t
svc_register (SVCXPRT *xprt, u_long prog, u_long vers,
	      void (*dispatch) (struct svc_req *, SVCXPRT *), u_long protocol)
{
  struct svc_callout *prev;
  register struct svc_callout *s;

  if ((s = svc_find (prog, vers, &prev)) != NULL_SVC)
    {
      if (s->sc_dispatch == dispatch)
	goto pmap_it;		/* he is registering another xptr */
      return FALSE;
    }
  s = (struct svc_callout *) mem_alloc (sizeof (struct svc_callout));
  if (s == (struct svc_callout *) 0)
    {
      return FALSE;
    }
  s->sc_prog = prog;
  s->sc_vers = vers;
  s->sc_dispatch = dispatch;
  s->sc_next = svc_head;
  svc_head = s;
pmap_it:
  /* now register the information with the local binder service */
  if (protocol)
    {
      return pmap_set (prog, vers, protocol, xprt->xp_port);
    }
  return TRUE;
}

/*
 * Remove a service program from the callout list.
 */
void
svc_unregister (prog, vers)
     u_long prog;
     u_long vers;
{
  struct svc_callout *prev;
  register struct svc_callout *s;

  if ((s = svc_find (prog, vers, &prev)) == NULL_SVC)
    return;
  if (prev == NULL_SVC)
    {
      svc_head = s->sc_next;
    }
  else
    {
      prev->sc_next = s->sc_next;
    }
  s->sc_next = NULL_SVC;
  mem_free ((char *) s, (u_int) sizeof (struct svc_callout));
  /* now unregister the information with the local binder service */
  (void) pmap_unset (prog, vers);
}

/*
 * Search the callout list for a program number, return the callout
 * struct.
 */
static struct svc_callout *
svc_find (u_long prog, u_long vers, struct svc_callout **prev)
{
  register struct svc_callout *s, *p;

  p = NULL_SVC;
  for (s = svc_head; s != NULL_SVC; s = s->sc_next)
    {
      if ((s->sc_prog == prog) && (s->sc_vers == vers))
	goto done;
      p = s;
    }
done:
  *prev = p;
  return s;
}

/* ******************* REPLY GENERATION ROUTINES  ************ */

/*
 * Send a reply to an rpc request
 */
bool_t
svc_sendreply (xprt, xdr_results, xdr_location)
     register SVCXPRT *xprt;
     xdrproc_t xdr_results;
     caddr_t xdr_location;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = SUCCESS;
  rply.acpted_rply.ar_results.where = xdr_location;
  rply.acpted_rply.ar_results.proc = xdr_results;
  return SVC_REPLY (xprt, &rply);
}

/*
 * No procedure error reply
 */
void
svcerr_noproc (xprt)
     register SVCXPRT *xprt;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROC_UNAVAIL;
  SVC_REPLY (xprt, &rply);
}

/*
 * Can't decode args error reply
 */
void
svcerr_decode (xprt)
     register SVCXPRT *xprt;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = GARBAGE_ARGS;
  SVC_REPLY (xprt, &rply);
}

/*
 * Some system error
 */
void
svcerr_systemerr (xprt)
     register SVCXPRT *xprt;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = SYSTEM_ERR;
  SVC_REPLY (xprt, &rply);
}

/*
 * Authentication error reply
 */
void
svcerr_auth (xprt, why)
     SVCXPRT *xprt;
     enum auth_stat why;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_DENIED;
  rply.rjcted_rply.rj_stat = AUTH_ERROR;
  rply.rjcted_rply.rj_why = why;
  SVC_REPLY (xprt, &rply);
}

/*
 * Auth too weak error reply
 */
void
svcerr_weakauth (xprt)
     SVCXPRT *xprt;
{

  svcerr_auth (xprt, AUTH_TOOWEAK);
}

/*
 * Program unavailable error reply
 */
void
svcerr_noprog (xprt)
     register SVCXPRT *xprt;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROG_UNAVAIL;
  SVC_REPLY (xprt, &rply);
}

/*
 * Program version mismatch error reply
 */
void
svcerr_progvers (xprt, low_vers, high_vers)
     register SVCXPRT *xprt;
     u_long low_vers;
     u_long high_vers;
{
  struct rpc_msg rply;

  rply.rm_direction = REPLY;
  rply.rm_reply.rp_stat = MSG_ACCEPTED;
  rply.acpted_rply.ar_verf = xprt->xp_verf;
  rply.acpted_rply.ar_stat = PROG_MISMATCH;
  rply.acpted_rply.ar_vers.low = low_vers;
  rply.acpted_rply.ar_vers.high = high_vers;
  SVC_REPLY (xprt, &rply);
}

/* ******************* SERVER INPUT STUFF ******************* */

/*
 * Get server side input from some transport.
 *
 * Statement of authentication parameters management:
 * This function owns and manages all authentication parameters, specifically
 * the "raw" parameters (msg.rm_call.cb_cred and msg.rm_call.cb_verf) and
 * the "cooked" credentials (rqst->rq_clntcred).
 * However, this function does not know the structure of the cooked
 * credentials, so it make the following assumptions:
 *   a) the structure is contiguous (no pointers), and
 *   b) the cred structure size does not exceed RQCRED_SIZE bytes.
 * In all events, all three parameters are freed upon exit from this routine.
 * The storage is trivially management on the call stack in user land, but
 * is mallocated in kernel land.
 */

void
svc_getreq (int rdfds)
{
#ifdef FD_SETSIZE
  fd_set readfds;

  FD_ZERO (&readfds);
  readfds.fds_bits[0] = rdfds;
  svc_getreqset (&readfds);
#else
  int readfds = rdfds & svc_fds;

  svc_getreqset (&readfds);
#endif /* def FD_SETSIZE */
}

void
svc_getreqset (readfds)
#ifdef FD_SETSIZE
     fd_set *readfds;
{
#else
     int *readfds;
{
  int readfds_local = *readfds;
#endif /* def FD_SETSIZE */
  enum xprt_stat stat;
  struct rpc_msg msg;
  int prog_found;
  u_long low_vers;
  u_long high_vers;
  struct svc_req r;
  register SVCXPRT *xprt;
  register u_long mask;
  register int bit;
  register u_int32_t *maskp;
  register int setsize;
  register int sock;
  char cred_area[2 * MAX_AUTH_BYTES + RQCRED_SIZE];
  msg.rm_call.cb_cred.oa_base = cred_area;
  msg.rm_call.cb_verf.oa_base = &(cred_area[MAX_AUTH_BYTES]);
  r.rq_clntcred = &(cred_area[2 * MAX_AUTH_BYTES]);


#ifdef FD_SETSIZE
  setsize = _rpc_dtablesize ();
  maskp = (u_int32_t *) readfds->fds_bits;
  for (sock = 0; sock < setsize; sock += 32)
    {
      for (mask = *maskp++; (bit = ffs (mask)); mask ^= (1 << (bit - 1)))
	{
	  /* sock has input waiting */
	  xprt = xports[sock + bit - 1];
#else
  for (sock = 0; readfds_local != 0; sock++, readfds_local >>= 1)
    {
      if ((readfds_local & 1) != 0)
	{
	  /* sock has input waiting */
	  xprt = xports[sock];
#endif /* def FD_SETSIZE */
	  if (xprt == NULL)
	    /* But do we control sock? */
	    continue;

	  /* now receive msgs from xprtprt (support batch calls) */
	  do
	    {
	      if (SVC_RECV (xprt, &msg))
		{

		  /* now find the exported program and call it */
		  register struct svc_callout *s;
		  enum auth_stat why;

		  r.rq_xprt = xprt;
		  r.rq_prog = msg.rm_call.cb_prog;
		  r.rq_vers = msg.rm_call.cb_vers;
		  r.rq_proc = msg.rm_call.cb_proc;
		  r.rq_cred = msg.rm_call.cb_cred;
		  /* first authenticate the message */
		  if ((why = _authenticate (&r, &msg)) != AUTH_OK)
		    {
		      svcerr_auth (xprt, why);
		      goto call_done;
		    }
		  /* now match message with a registered service */
		  prog_found = FALSE;
		  low_vers = 0 - 1;
		  high_vers = 0;
		  for (s = svc_head; s != NULL_SVC; s = s->sc_next)
		    {
		      if (s->sc_prog == r.rq_prog)
			{
			  if (s->sc_vers == r.rq_vers)
			    {
			      (*s->sc_dispatch) (&r, xprt);
			      goto call_done;
			    }	/* found correct version */
			  prog_found = TRUE;
			  if (s->sc_vers < low_vers)
			    low_vers = s->sc_vers;
			  if (s->sc_vers > high_vers)
			    high_vers = s->sc_vers;
			}	/* found correct program */
		    }
		  /*
		   * if we got here, the program or version
		   * is not served ...
		   */
		  if (prog_found)
		    svcerr_progvers (xprt, low_vers, high_vers);
		  else
		    svcerr_noprog (xprt);
		  /* Fall through to ... */
		}
	    call_done:
	      if ((stat = SVC_STAT (xprt)) == XPRT_DIED)
		{
		  SVC_DESTROY (xprt);
		  break;
		}
	    }
	  while (stat == XPRT_MOREREQS);
	}
    }
}
