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/* @(#)svc_udp.c        2.2 88/07/29 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 0

static char sccsid[] = "@(#)svc_udp.c 1.24 87/08/11 Copyr 1984 Sun Micro";

#endif

/*

 * svc_udp.c,

 * Server side for UDP/IP based RPC.  (Does some caching in the hopes of

 * achieving execute-at-most-once semantics.)

 *

 * Copyright (C) 1984, Sun Microsystems, Inc.

 */

#define __FORCE_GLIBC

#define _GNU_SOURCE

#include <features.h>

#include <stdio.h>

#include <unistd.h>

#include <string.h>

#include <rpc/rpc.h>

#include <sys/socket.h>

#include <errno.h>

#ifdef IP_PKTINFO

#include <sys/uio.h>

#endif

#ifdef USE_IN_LIBIO

# include <wchar.h>

# include <libio/iolibio.h>

# define fputs(s, f) _IO_fputs (s, f)

#endif

#define rpc_buffer(xprt) ((xprt)->xp_p1)

#ifndef MAX

#define MAX(a, b)     ((a > b) ? a : b)

#endif

static bool_t svcudp_recv (SVCXPRT *, struct rpc_msg *);

static bool_t svcudp_reply (SVCXPRT *, struct rpc_msg *);

static enum xprt_stat svcudp_stat (SVCXPRT *);

static bool_t svcudp_getargs (SVCXPRT *, xdrproc_t, caddr_t);

static bool_t svcudp_freeargs (SVCXPRT *, xdrproc_t, caddr_t);

static void svcudp_destroy (SVCXPRT *);

static const struct xp_ops svcudp_op =

{

  svcudp_recv,

  svcudp_stat,

  svcudp_getargs,

  svcudp_reply,

  svcudp_freeargs,

  svcudp_destroy

};

static int cache_get (SVCXPRT *, struct rpc_msg *, char **replyp,

                      u_long *replylenp);

static void cache_set (SVCXPRT *xprt, u_long replylen);

/*

 * kept in xprt->xp_p2

 */

struct svcudp_data

  {

    u_int su_iosz;              /* byte size of send.recv buffer */

    u_long su_xid;              /* transaction id */

    XDR su_xdrs;                /* XDR handle */

    char su_verfbody[MAX_AUTH_BYTES];   /* verifier body */

    char *su_cache;             /* cached data, NULL if no cache */

  };

#define su_data(xprt)   ((struct svcudp_data *)(xprt->xp_p2))

/*

 * Usage:

 *      xprt = svcudp_create(sock);

 *

 * If sock<0 then a socket is created, else sock is used.

 * If the socket, sock is not bound to a port then svcudp_create

 * binds it to an arbitrary port.  In any (successful) case,

 * xprt->xp_sock is the registered socket number and xprt->xp_port is the

 * associated port number.

 * Once *xprt is initialized, it is registered as a transporter;

 * see (svc.h, xprt_register).

 * The routines returns NULL if a problem occurred.

 */

SVCXPRT *

svcudp_bufcreate (sock, sendsz, recvsz)

     int sock;

     u_int sendsz, recvsz;

{

  bool_t madesock = FALSE;

  SVCXPRT *xprt;

  struct svcudp_data *su;

  struct sockaddr_in addr;

  socklen_t len = sizeof (struct sockaddr_in);

  int pad;

  void *buf;

  if (sock == RPC_ANYSOCK)

    {

      if ((sock = socket (AF_INET, SOCK_DGRAM, IPPROTO_UDP)) < 0)

        {

          perror (_("svcudp_create: 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)

    {

      perror (_("svcudp_create - cannot getsockname"));

      if (madesock)

        (void) close (sock);

      return (SVCXPRT *) NULL;

    }

  xprt = (SVCXPRT *) mem_alloc (sizeof (SVCXPRT));

  su = (struct svcudp_data *) mem_alloc (sizeof (*su));

  buf = mem_alloc (((MAX (sendsz, recvsz) + 3) / 4) * 4);

  if (xprt == NULL || su == NULL || buf == NULL)

    {

#ifdef USE_IN_LIBIO

      if (_IO_fwide (stderr, 0) > 0)

        (void) __fwprintf (stderr, L"%s", _("svcudp_create: out of memory\n"));

      else

#endif

        (void) fputs (_("svcudp_create: out of memory\n"), stderr);

      mem_free (xprt, sizeof (SVCXPRT));

      mem_free (su, sizeof (*su));

      mem_free (buf, ((MAX (sendsz, recvsz) + 3) / 4) * 4);

      return NULL;

    }

  su->su_iosz = ((MAX (sendsz, recvsz) + 3) / 4) * 4;

  rpc_buffer (xprt) = buf;

  xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_DECODE);

  su->su_cache = NULL;

  xprt->xp_p2 = (caddr_t) su;

  xprt->xp_verf.oa_base = su->su_verfbody;

  xprt->xp_ops = &svcudp_op;

  xprt->xp_port = ntohs (addr.sin_port);

  xprt->xp_sock = sock;

#ifdef IP_PKTINFO

  if ((sizeof (struct iovec) + sizeof (struct msghdr)

       + sizeof(struct cmsghdr) + sizeof (struct in_pktinfo))

      > sizeof (xprt->xp_pad))

    {

# ifdef USE_IN_LIBIO

      if (_IO_fwide (stderr, 0) > 0)

        (void) __fwprintf (stderr, L"%s",

                           _("svcudp_create: xp_pad is too small for IP_PKTINFO\n"));

      else

# endif

        (void) fputs (_("svcudp_create: xp_pad is too small for IP_PKTINFO\n"),

                      stderr);

      return NULL;

    }

  pad = 1;

  if (setsockopt (sock, SOL_IP, IP_PKTINFO, (void *) &pad,

                  sizeof (pad)) == 0)

    /* Set the padding to all 1s. */

    pad = 0xff;

  else

#endif

    /* Clear the padding. */

    pad = 0;

  memset (&xprt->xp_pad [0], pad, sizeof (xprt->xp_pad));

  xprt_register (xprt);

  return xprt;

}

SVCXPRT *

svcudp_create (sock)

     int sock;

{

  return svcudp_bufcreate (sock, UDPMSGSIZE, UDPMSGSIZE);

}

static enum xprt_stat

svcudp_stat (xprt)

     SVCXPRT *xprt;

{

  return XPRT_IDLE;

}

static bool_t

svcudp_recv (xprt, msg)

     SVCXPRT *xprt;

     struct rpc_msg *msg;

{

  struct svcudp_data *su = su_data (xprt);

  XDR *xdrs = &(su->su_xdrs);

  int rlen;

  char *reply;

  u_long replylen;

  socklen_t len;

  /* It is very tricky when you have IP aliases. We want to make sure

     that we are sending the packet from the IP address where the

     incoming packet is addressed to. H.J. */

#ifdef IP_PKTINFO

  struct iovec *iovp;

  struct msghdr *mesgp;

#endif

again:

  /* FIXME -- should xp_addrlen be a size_t?  */

  len = (socklen_t) sizeof(struct sockaddr_in);

#ifdef IP_PKTINFO

  iovp = (struct iovec *) &xprt->xp_pad [0];

  mesgp = (struct msghdr *) &xprt->xp_pad [sizeof (struct iovec)];

  if (mesgp->msg_iovlen)

    {

      iovp->iov_base = rpc_buffer (xprt);

      iovp->iov_len = su->su_iosz;

      mesgp->msg_iov = iovp;

      mesgp->msg_iovlen = 1;

      mesgp->msg_name = &(xprt->xp_raddr);

      mesgp->msg_namelen = len;

      mesgp->msg_control = &xprt->xp_pad [sizeof (struct iovec)

                                          + sizeof (struct msghdr)];

      mesgp->msg_controllen = sizeof(xprt->xp_pad)

                              - sizeof (struct iovec) - sizeof (struct msghdr);

      rlen = recvmsg (xprt->xp_sock, mesgp, 0);

      if (rlen >= 0)

        len = mesgp->msg_namelen;

    }

  else

#endif

    rlen = recvfrom (xprt->xp_sock, rpc_buffer (xprt),

                     (int) su->su_iosz, 0,

                     (struct sockaddr *) &(xprt->xp_raddr), &len);

  xprt->xp_addrlen = len;

  if (rlen == -1 && errno == EINTR)

    goto again;

  if (rlen < 16)                /* < 4 32-bit ints? */

    return FALSE;

  xdrs->x_op = XDR_DECODE;

  XDR_SETPOS (xdrs, 0);

  if (!xdr_callmsg (xdrs, msg))

    return FALSE;

  su->su_xid = msg->rm_xid;

  if (su->su_cache != NULL)

    {

      if (cache_get (xprt, msg, &reply, &replylen))

        {

#ifdef IP_PKTINFO

          if (mesgp->msg_iovlen)

            {

              iovp->iov_base = reply;

              iovp->iov_len = replylen;

              (void) sendmsg (xprt->xp_sock, mesgp, 0);

            }

          else

#endif

            (void) sendto (xprt->xp_sock, reply, (int) replylen, 0,

                           (struct sockaddr *) &xprt->xp_raddr, len);

          return TRUE;

        }

    }

  return TRUE;

}

static bool_t

svcudp_reply (xprt, msg)

     SVCXPRT *xprt;

     struct rpc_msg *msg;

{

  struct svcudp_data *su = su_data (xprt);

  XDR *xdrs = &(su->su_xdrs);

  int slen, sent;

  bool_t stat = FALSE;

#ifdef IP_PKTINFO

  struct iovec *iovp;

  struct msghdr *mesgp;

#endif

  xdrs->x_op = XDR_ENCODE;

  XDR_SETPOS (xdrs, 0);

  msg->rm_xid = su->su_xid;

  if (xdr_replymsg (xdrs, msg))

    {

      slen = (int) XDR_GETPOS (xdrs);

#ifdef IP_PKTINFO

      mesgp = (struct msghdr *) &xprt->xp_pad [sizeof (struct iovec)];

      if (mesgp->msg_iovlen)

        {

          iovp = (struct iovec *) &xprt->xp_pad [0];

          iovp->iov_base = rpc_buffer (xprt);

          iovp->iov_len = slen;

          sent = sendmsg (xprt->xp_sock, mesgp, 0);

        }

      else

#endif

        sent = sendto (xprt->xp_sock, rpc_buffer (xprt), slen, 0,

                       (struct sockaddr *) &(xprt->xp_raddr),

                       xprt->xp_addrlen);

      if (sent == slen)

        {

          stat = TRUE;

          if (su->su_cache && slen >= 0)

            {

              cache_set (xprt, (u_long) slen);

            }

        }

    }

  return stat;

}

static bool_t

svcudp_getargs (xprt, xdr_args, args_ptr)

     SVCXPRT *xprt;

     xdrproc_t xdr_args;

     caddr_t args_ptr;

{

  return (*xdr_args) (&(su_data (xprt)->su_xdrs), args_ptr);

}

static bool_t

svcudp_freeargs (xprt, xdr_args, args_ptr)

     SVCXPRT *xprt;

     xdrproc_t xdr_args;

     caddr_t args_ptr;

{

  XDR *xdrs = &(su_data (xprt)->su_xdrs);

  xdrs->x_op = XDR_FREE;

  return (*xdr_args) (xdrs, args_ptr);

}

static void

svcudp_destroy (xprt)

     SVCXPRT *xprt;

{

  struct svcudp_data *su = su_data (xprt);

  xprt_unregister (xprt);

  (void) close (xprt->xp_sock);

  XDR_DESTROY (&(su->su_xdrs));

  mem_free (rpc_buffer (xprt), su->su_iosz);

  mem_free ((caddr_t) su, sizeof (struct svcudp_data));

  mem_free ((caddr_t) xprt, sizeof (SVCXPRT));

}

/***********this could be a separate file*********************/

/*

 * Fifo cache for udp server

 * Copies pointers to reply buffers into fifo cache

 * Buffers are sent again if retransmissions are detected.

 */

#define SPARSENESS 4            /* 75% sparse */

#ifdef USE_IN_LIBIO

# define CACHE_PERROR(msg)      \

        if (_IO_fwide (stderr, 0) > 0)                                          \

                (void) __fwprintf(stderr, L"%s\n", msg);                      \

        else                                                                  \

                (void) fprintf(stderr, "%s\n", msg)

#else

# define CACHE_PERROR(msg)      \

        (void) fprintf(stderr,"%s\n", msg)

#endif

#define ALLOC(type, size)       \

        (type *) mem_alloc((unsigned) (sizeof(type) * (size)))

#define BZERO(addr, type, size)  \

        bzero((char *) addr, sizeof(type) * (int) (size))

/*

 * An entry in the cache

 */

typedef struct cache_node *cache_ptr;

struct cache_node

  {

    /*

     * Index into cache is xid, proc, vers, prog and address

     */

    u_long cache_xid;

    u_long cache_proc;

    u_long cache_vers;

    u_long cache_prog;

    struct sockaddr_in cache_addr;

    /*

     * The cached reply and length

     */

    char *cache_reply;

    u_long cache_replylen;

    /*

     * Next node on the list, if there is a collision

     */

    cache_ptr cache_next;

  };

/*

 * The entire cache

 */

struct udp_cache

  {

    u_long uc_size;             /* size of cache */

    cache_ptr *uc_entries;      /* hash table of entries in cache */

    cache_ptr *uc_fifo;         /* fifo list of entries in cache */

    u_long uc_nextvictim;       /* points to next victim in fifo list */

    u_long uc_prog;             /* saved program number */

    u_long uc_vers;             /* saved version number */

    u_long uc_proc;             /* saved procedure number */

    struct sockaddr_in uc_addr; /* saved caller's address */

  };

/*

 * the hashing function

 */

#define CACHE_LOC(transp, xid)  \

 (xid % (SPARSENESS*((struct udp_cache *) su_data(transp)->su_cache)->uc_size))

/*

 * Enable use of the cache.

 * Note: there is no disable.

 */

int

svcudp_enablecache (SVCXPRT *transp, u_long size)

{

  struct svcudp_data *su = su_data (transp);

  struct udp_cache *uc;

  if (su->su_cache != NULL)

    {

      CACHE_PERROR (_("enablecache: cache already enabled"));

      return 0;

    }

  uc = ALLOC (struct udp_cache, 1);

  if (uc == NULL)

    {

      CACHE_PERROR (_("enablecache: could not allocate cache"));

      return 0;

    }

  uc->uc_size = size;

  uc->uc_nextvictim = 0;

  uc->uc_entries = ALLOC (cache_ptr, size * SPARSENESS);

  if (uc->uc_entries == NULL)

    {

      CACHE_PERROR (_("enablecache: could not allocate cache data"));

      return 0;

    }

  BZERO (uc->uc_entries, cache_ptr, size * SPARSENESS);

  uc->uc_fifo = ALLOC (cache_ptr, size);

  if (uc->uc_fifo == NULL)

    {

      CACHE_PERROR (_("enablecache: could not allocate cache fifo"));

      return 0;

    }

  BZERO (uc->uc_fifo, cache_ptr, size);

  su->su_cache = (char *) uc;

  return 1;

}

/*

 * Set an entry in the cache

 */

static void

cache_set (SVCXPRT *xprt, u_long replylen)

{

  cache_ptr victim;

  cache_ptr *vicp;

  struct svcudp_data *su = su_data (xprt);

  struct udp_cache *uc = (struct udp_cache *) su->su_cache;

  u_int loc;

  char *newbuf;

  /*

   * Find space for the new entry, either by

   * reusing an old entry, or by mallocing a new one

   */

  victim = uc->uc_fifo[uc->uc_nextvictim];

  if (victim != NULL)

    {

      loc = CACHE_LOC (xprt, victim->cache_xid);

      for (vicp = &uc->uc_entries[loc];

           *vicp != NULL && *vicp != victim;

           vicp = &(*vicp)->cache_next)

        ;

      if (*vicp == NULL)

        {

          CACHE_PERROR (_("cache_set: victim not found"));

          return;

        }

      *vicp = victim->cache_next;       /* remote from cache */

      newbuf = victim->cache_reply;

    }

  else

    {

      victim = ALLOC (struct cache_node, 1);

      if (victim == NULL)

        {

          CACHE_PERROR (_("cache_set: victim alloc failed"));

          return;

        }

      newbuf = mem_alloc (su->su_iosz);

      if (newbuf == NULL)

        {

          CACHE_PERROR (_("cache_set: could not allocate new rpc_buffer"));

          return;

        }

    }

  /*

   * Store it away

   */

  victim->cache_replylen = replylen;

  victim->cache_reply = rpc_buffer (xprt);

  rpc_buffer (xprt) = newbuf;

  xdrmem_create (&(su->su_xdrs), rpc_buffer (xprt), su->su_iosz, XDR_ENCODE);

  victim->cache_xid = su->su_xid;

  victim->cache_proc = uc->uc_proc;

  victim->cache_vers = uc->uc_vers;

  victim->cache_prog = uc->uc_prog;

  victim->cache_addr = uc->uc_addr;

  loc = CACHE_LOC (xprt, victim->cache_xid);

  victim->cache_next = uc->uc_entries[loc];

  uc->uc_entries[loc] = victim;

  uc->uc_fifo[uc->uc_nextvictim++] = victim;

  uc->uc_nextvictim %= uc->uc_size;

}

/*

 * Try to get an entry from the cache

 * return 1 if found, 0 if not found

 */

static int

cache_get (xprt, msg, replyp, replylenp)

     SVCXPRT *xprt;

     struct rpc_msg *msg;

     char **replyp;

     u_long *replylenp;

{

  u_int loc;

  cache_ptr ent;

  struct svcudp_data *su = su_data (xprt);

  struct udp_cache *uc = (struct udp_cache *) su->su_cache;

#define EQADDR(a1, a2)  (memcmp((char*)&a1, (char*)&a2, sizeof(a1)) == 0)

  loc = CACHE_LOC (xprt, su->su_xid);

  for (ent = uc->uc_entries[loc]; ent != NULL; ent = ent->cache_next)

    {

      if (ent->cache_xid == su->su_xid &&

          ent->cache_proc == uc->uc_proc &&

          ent->cache_vers == uc->uc_vers &&

          ent->cache_prog == uc->uc_prog &&

          EQADDR (ent->cache_addr, uc->uc_addr))

        {

          *replyp = ent->cache_reply;

          *replylenp = ent->cache_replylen;

          return 1;

        }

    }

  /*

   * Failed to find entry

   * Remember a few things so we can do a set later

   */

  uc->uc_proc = msg->rm_call.cb_proc;

  uc->uc_vers = msg->rm_call.cb_vers;

  uc->uc_prog = msg->rm_call.cb_prog;

  memcpy (&uc->uc_addr, &xprt->xp_raddr, sizeof (uc->uc_addr));

  return 0;

}