/* loop.c - Main server loop for nfs server.
   Copyright (C) 1996,98,2002,2006 Free Software Foundation, Inc.
   Written by Michael I. Bushnell, p/BSG.

   This file is part of the GNU Hurd.

   The GNU Hurd is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License as
   published by the Free Software Foundation; either version 2, or (at
   your option) any later version.

   The GNU Hurd is distributed in the hope that it will be useful, but
   WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA. */

#include <string.h>
#include <fcntl.h>

#include "nfsd.h"

#include <rpc/pmap_prot.h>
#include "../nfs/mount.h"

#undef TRUE
#undef FALSE
#define malloc spoogie_woogie /* barf */
#include <rpc/xdr.h>
#include <rpc/types.h>
#include <rpc/auth.h>
#include <rpc/rpc_msg.h>
#undef malloc

void *
server_loop (void *arg)
{
  int fd = (int) arg;
  char buf[MAXIOSIZE];
  int xid;
  int *p, *r;
  char *rbuf;
  struct cached_reply *cr;
  int program;
  struct sockaddr_in sender;
  int version;
  int procedure;
  struct proctable *table = 0;
  struct procedure *proc;
  struct idspec *cred;
  struct cache_handle *c, fakec;
  error_t err;
  socklen_t addrlen;
  int cc;

  memset (&fakec, 0, sizeof (struct cache_handle));

  for (;;)
    {
      p = (int *) buf;
      proc = 0;
      addrlen = sizeof (struct sockaddr_in);
      cc = recvfrom (fd, buf, MAXIOSIZE, 0, &sender, &addrlen);
      if (cc == -1)
	continue;		/* Ignore errors.  */
      xid = *(p++);

      /* Ignore things that aren't proper RPCs.  */
      if (ntohl (*p) != CALL)
	continue;
      p++;

      cr = check_cached_replies (xid, &sender);
      if (cr->data)
	/* This transacation has already completed.  */
	goto repost_reply;

      r = (int *) (rbuf = malloc (MAXIOSIZE));

      if (ntohl (*p) != RPC_MSG_VERSION)
	{
	  /* Reject RPC.  */
	  *(r++) = xid;
	  *(r++) = htonl (REPLY);
	  *(r++) = htonl (MSG_DENIED);
	  *(r++) = htonl (RPC_MISMATCH);
	  *(r++) = htonl (RPC_MSG_VERSION);
	  *(r++) = htonl (RPC_MSG_VERSION);
	  goto send_reply;
	}
      p++;

      program = ntohl (*p);
      p++;
      switch (program)
	{
	case MOUNTPROG:
	  version = MOUNTVERS;
	  table = &mounttable;
	  break;

	case NFS_PROGRAM:
	  version = NFS_VERSION;
	  table = &nfs2table;
	  break;

	case PMAPPROG:
	  version = PMAPVERS;
	  table = &pmaptable;
	  break;

	default:
	  /* Program unavailable.  */
	  *(r++) = xid;
	  *(r++) = htonl (REPLY);
	  *(r++) = htonl (MSG_ACCEPTED);
	  *(r++) = htonl (AUTH_NULL);
	  *(r++) = htonl (0);
	  *(r++) = htonl (PROG_UNAVAIL);
	  goto send_reply;
	}

      if (ntohl (*p) != version)
	{
	  /* Program mismatch.  */
	  *(r++) = xid;
	  *(r++) = htonl (REPLY);
	  *(r++) = htonl (MSG_ACCEPTED);
	  *(r++) = htonl (AUTH_NULL);
	  *(r++) = htonl (0);
	  *(r++) = htonl (PROG_MISMATCH);
	  *(r++) = htonl (version);
	  *(r++) = htonl (version);
	  goto send_reply;
	}
      p++;

      procedure = htonl (*p);
      p++;
      if (procedure < table->min
	  || procedure > table->max
	  || table->procs[procedure - table->min].func == 0)
	{
	  /* Procedure unavailable.  */
	  *(r++) = xid;
	  *(r++) = htonl (REPLY);
	  *(r++) = htonl (MSG_ACCEPTED);
	  *(r++) = htonl (AUTH_NULL);
	  *(r++) = htonl (0);
	  *(r++) = htonl (PROC_UNAVAIL);
	  *(r++) = htonl (table->min);
	  *(r++) = htonl (table->max);
	  goto send_reply;
	}
      proc = &table->procs[procedure - table->min];

      p = process_cred (p, &cred);

      if (proc->need_handle)
	p = lookup_cache_handle (p, &c, cred);
      else
	{
	  fakec.ids = cred;
	  c = &fakec;
	}

      if (proc->alloc_reply)
	{
	  size_t amt;
	  amt = (*proc->alloc_reply) (p, version) + 256;
	  if (amt > MAXIOSIZE)
	    {
	      free (rbuf);
	      r = (int *) (rbuf = malloc (amt));
	    }
	}

      /* Fill in beginning of reply.  */
      *(r++) = xid;
      *(r++) = htonl (REPLY);
      *(r++) = htonl (MSG_ACCEPTED);
      *(r++) = htonl (AUTH_NULL);
      *(r++) = htonl (0);
      *(r++) = htonl (SUCCESS);
      if (!proc->process_error)
	/* The function does its own error processing, and we ignore
	   its return value.  */
	(void) (*proc->func) (c, p, &r, version);
      else
	{
	  if (c)
	    {
	      /* Assume success for now and patch it later if necessary.  */
	      int *errloc = r;
	      *(r++) = htonl (0);
	      /* Call processing function, its output after error code.  */
	      err = (*proc->func) (c, p, &r, version);
	      if (err)
		{
		  r = errloc;	/* Back up, patch error code, discard rest.  */
		  *(r++) = htonl (nfs_error_trans (err, version));
		}
	    }
	  else
	    *(r++) = htonl (nfs_error_trans (ESTALE, version));
	}

      cred_rele (cred);
      if (c && c != &fakec)
	cache_handle_rele (c);

    send_reply:
      cr->data = rbuf;
      cr->len = (char *)r - rbuf;

    repost_reply:
      sendto (fd, cr->data, cr->len, 0,
	      (struct sockaddr *) &sender, addrlen);
      release_cached_reply (cr);
    }
}