/*

 * clnt_udp.c, Implements a UDP/IP based, client side RPC.

 *

 * Copyright (c) 2010, Oracle America, Inc.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are

 * met:

 *

 *     * Redistributions of source code must retain the above copyright

 *       notice, this list of conditions and the following disclaimer.

 *     * Redistributions in binary form must reproduce the above

 *       copyright notice, this list of conditions and the following

 *       disclaimer in the documentation and/or other materials

 *       provided with the distribution.

 *     * Neither the name of the "Oracle America, Inc." nor the names of its

 *       contributors may be used to endorse or promote products derived

 *       from this software without specific prior written permission.

 *

 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 *   FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 *   COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,

 *   INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 *   DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

 *   GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

 *   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,

 *   WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING

 *   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include <stdio.h>

#include <unistd.h>

#include <libintl.h>

#include <rpc/rpc.h>

#include <rpc/xdr.h>

#include <rpc/clnt.h>

#include <sys/poll.h>

#include <sys/socket.h>

#include <sys/ioctl.h>

#include <netdb.h>

#include <errno.h>

#include <stdint.h>

#include <rpc/pmap_clnt.h>

#include <net/if.h>

#include <ifaddrs.h>

#include <wchar.h>

#include <fcntl.h>

#ifdef IP_RECVERR

#include <errqueue.h>

#include <sys/uio.h>

#endif

#include <kernel-features.h>

#include <inet/net-internal.h>

#include <shlib-compat.h>

extern u_long _create_xid (void);

/*

 * UDP bases client side rpc operations

 */

static enum clnt_stat clntudp_call (CLIENT *, u_long, xdrproc_t, caddr_t,

				    xdrproc_t, caddr_t, struct timeval);

static void clntudp_abort (void);

static void clntudp_geterr (CLIENT *, struct rpc_err *);

static bool_t clntudp_freeres (CLIENT *, xdrproc_t, caddr_t);

static bool_t clntudp_control (CLIENT *, int, char *);

static void clntudp_destroy (CLIENT *);

static const struct clnt_ops udp_ops =

{

  clntudp_call,

  clntudp_abort,

  clntudp_geterr,

  clntudp_freeres,

  clntudp_destroy,

  clntudp_control

};

/*

 * Private data kept per client handle.  This private struct is

 * unfortunately part of the ABI; ypbind contains a copy of it and

 * accesses it through CLIENT::cl_private field.

 */

struct cu_data

  {

    int cu_sock;

    bool_t cu_closeit;

    struct sockaddr_in cu_raddr;

    int cu_rlen;

    struct timeval cu_wait;

    struct timeval cu_total;

    struct rpc_err cu_error;

    XDR cu_outxdrs;

    u_int cu_xdrpos;

    u_int cu_sendsz;

    char *cu_outbuf;

    u_int cu_recvsz;

    char cu_inbuf[1];

  };

/*

 * Create a UDP based client handle.

 * If *sockp<0, *sockp is set to a newly created UPD socket.

 * If raddr->sin_port is 0 a binder on the remote machine

 * is consulted for the correct port number.

 * NB: It is the clients responsibility to close *sockp.

 * NB: The rpch->cl_auth is initialized to null authentication.

 *     Caller may wish to set this something more useful.

 *

 * wait is the amount of time used between retransmitting a call if

 * no response has been heard; retransmission occurs until the actual

 * rpc call times out.

 *

 * sendsz and recvsz are the maximum allowable packet sizes that can be

 * sent and received.

 */

CLIENT *

__libc_clntudp_bufcreate (struct sockaddr_in *raddr, u_long program,

			  u_long version, struct timeval wait, int *sockp,

			  u_int sendsz, u_int recvsz, int flags)

{

  CLIENT *cl;

  struct cu_data *cu = NULL;

  struct rpc_msg call_msg;

  cl = (CLIENT *) mem_alloc (sizeof (CLIENT));

  sendsz = ((sendsz + 3) / 4) * 4;

  recvsz = ((recvsz + 3) / 4) * 4;

  cu = (struct cu_data *) mem_alloc (sizeof (*cu) + sendsz + recvsz);

  if (cl == NULL || cu == NULL)

    {

      struct rpc_createerr *ce = &get_rpc_createerr ();

      (void) __fxprintf (NULL, "%s: %s",

			 "clntudp_create", _("out of memory\n"));

      ce->cf_stat = RPC_SYSTEMERROR;

      ce->cf_error.re_errno = ENOMEM;

      goto fooy;

    }

  cu->cu_outbuf = &cu->cu_inbuf[recvsz];

  if (raddr->sin_port == 0)

    {

      u_short port;

      if ((port =

	   pmap_getport (raddr, program, version, IPPROTO_UDP)) == 0)

	{

	  goto fooy;

	}

      raddr->sin_port = htons (port);

    }

  cl->cl_ops = (struct clnt_ops *) &udp_ops;

  cl->cl_private = (caddr_t) cu;

  cu->cu_raddr = *raddr;

  cu->cu_rlen = sizeof (cu->cu_raddr);

  cu->cu_wait = wait;

  cu->cu_total.tv_sec = -1;

  cu->cu_total.tv_usec = -1;

  cu->cu_sendsz = sendsz;

  cu->cu_recvsz = recvsz;

  call_msg.rm_xid = _create_xid ();

  call_msg.rm_direction = CALL;

  call_msg.rm_call.cb_rpcvers = RPC_MSG_VERSION;

  call_msg.rm_call.cb_prog = program;

  call_msg.rm_call.cb_vers = version;

  xdrmem_create (&(cu->cu_outxdrs), cu->cu_outbuf, sendsz, XDR_ENCODE);

  if (!xdr_callhdr (&(cu->cu_outxdrs), &call_msg))

    {

      goto fooy;

    }

  cu->cu_xdrpos = XDR_GETPOS (&(cu->cu_outxdrs));

  if (*sockp < 0)

    {

      *sockp = __socket (AF_INET, SOCK_DGRAM|SOCK_NONBLOCK|flags, IPPROTO_UDP);

      if (__glibc_unlikely (*sockp < 0))

	{

	  struct rpc_createerr *ce = &get_rpc_createerr ();

	  ce->cf_stat = RPC_SYSTEMERROR;

	  ce->cf_error.re_errno = errno;

	  goto fooy;

	}

      /* attempt to bind to prov port */

      (void) bindresvport (*sockp, (struct sockaddr_in *) 0);

#ifdef IP_RECVERR

      {

	int on = 1;

	__setsockopt (*sockp, SOL_IP, IP_RECVERR, &on, sizeof(on));

      }

#endif

      cu->cu_closeit = TRUE;

    }

  else

    {

      cu->cu_closeit = FALSE;

    }

  cu->cu_sock = *sockp;

  cl->cl_auth = authnone_create ();

  return cl;

fooy:

  if (cu)

    mem_free ((caddr_t) cu, sizeof (*cu) + sendsz + recvsz);

  if (cl)

    mem_free ((caddr_t) cl, sizeof (CLIENT));

  return (CLIENT *) NULL;

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (__libc_clntudp_bufcreate)

#else

libc_hidden_nolink_sunrpc (__libc_clntudp_bufcreate, GLIBC_PRIVATE)

#endif

CLIENT *

clntudp_bufcreate (struct sockaddr_in *raddr, u_long program, u_long version,

		   struct timeval wait, int *sockp, u_int sendsz,

		   u_int recvsz)

{

  return __libc_clntudp_bufcreate (raddr, program, version, wait,

				   sockp, sendsz, recvsz, 0);

}

libc_hidden_nolink_sunrpc (clntudp_bufcreate, GLIBC_2_0)

CLIENT *

clntudp_create (struct sockaddr_in *raddr, u_long program, u_long version,

		struct timeval wait, int *sockp)

{

  return __libc_clntudp_bufcreate (raddr, program, version, wait,

				   sockp, UDPMSGSIZE, UDPMSGSIZE, 0);

}

#ifdef EXPORT_RPC_SYMBOLS

libc_hidden_def (clntudp_create)

#else

libc_hidden_nolink_sunrpc (clntudp_create, GLIBC_2_0)

#endif

static int

is_network_up (int sock)

{

  struct ifaddrs *ifa;

  if (getifaddrs (&ifa) != 0)

    return 0;

  struct ifaddrs *run = ifa;

  while (run != NULL)

    {

      if ((run->ifa_flags & IFF_UP) != 0

	  && run->ifa_addr != NULL

	  && run->ifa_addr->sa_family == AF_INET)

	break;

      run = run->ifa_next;

    }

  freeifaddrs (ifa);

  return run != NULL;

}

static enum clnt_stat

clntudp_call (/* client handle */

	      CLIENT *cl,

	      /* procedure number */

	      u_long proc,

	      /* xdr routine for args */

	      xdrproc_t xargs,

	      /* pointer to args */

	      caddr_t argsp,

	      /* xdr routine for results */

	      xdrproc_t xresults,

	      /* pointer to results */

	      caddr_t resultsp,

	      /* seconds to wait before giving up */

	      struct timeval utimeout)

{

  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  XDR *xdrs;

  int outlen = 0;

  int inlen;

  socklen_t fromlen;

  struct pollfd fd;

  struct sockaddr_in from;

  struct rpc_msg reply_msg;

  XDR reply_xdrs;

  bool_t ok;

  int nrefreshes = 2;		/* number of times to refresh cred */

  int anyup;			/* any network interface up */

  struct deadline_current_time current_time = __deadline_current_time ();

  struct deadline total_deadline; /* Determined once by overall timeout.  */

  struct deadline response_deadline; /* Determined anew for each query.  */

  /* Choose the timeout value.  For non-sending usage (xargs == NULL),

     the total deadline does not matter, only cu->cu_wait is used

     below.  */

  if (xargs != NULL)

    {

      struct timeval tv;

      if (cu->cu_total.tv_usec == -1)

	/* Use supplied timeout.  */

	tv = utimeout;

      else

	/* Use default timeout.  */

	tv = cu->cu_total;

      if (!__is_timeval_valid_timeout (tv))

	return (cu->cu_error.re_status = RPC_TIMEDOUT);

      total_deadline = __deadline_from_timeval (current_time, tv);

    }

  /* Guard against bad timeout specification.  */

  if (!__is_timeval_valid_timeout (cu->cu_wait))

    return (cu->cu_error.re_status = RPC_TIMEDOUT);

call_again:

  xdrs = &(cu->cu_outxdrs);

  if (xargs == NULL)

    goto get_reply;

  xdrs->x_op = XDR_ENCODE;

  XDR_SETPOS (xdrs, cu->cu_xdrpos);

  /*

   * the transaction is the first thing in the out buffer

   */

  (*(uint32_t *) (cu->cu_outbuf))++;

  if ((!XDR_PUTLONG (xdrs, (long *) &proc)) ||

      (!AUTH_MARSHALL (cl->cl_auth, xdrs)) ||

      (!(*xargs) (xdrs, argsp)))

    return (cu->cu_error.re_status = RPC_CANTENCODEARGS);

  outlen = (int) XDR_GETPOS (xdrs);

send_again:

  if (__sendto (cu->cu_sock, cu->cu_outbuf, outlen, 0,

		(struct sockaddr *) &(cu->cu_raddr), cu->cu_rlen)

      != outlen)

    {

      cu->cu_error.re_errno = errno;

      return (cu->cu_error.re_status = RPC_CANTSEND);

    }

  /* sendto may have blocked, so recompute the current time.  */

  current_time = __deadline_current_time ();

 get_reply:

  response_deadline = __deadline_from_timeval (current_time, cu->cu_wait);

  reply_msg.acpted_rply.ar_verf = _null_auth;

  reply_msg.acpted_rply.ar_results.where = resultsp;

  reply_msg.acpted_rply.ar_results.proc = xresults;

  fd.fd = cu->cu_sock;

  fd.events = POLLIN;

  anyup = 0;

  /* Per-response retry loop.  current_time must be up-to-date at the

     top of the loop.  */

  for (;;)

    {

      int milliseconds;

      if (xargs != NULL)

	{

	  if (__deadline_elapsed (current_time, total_deadline))

	    /* Overall timeout expired.  */

	    return (cu->cu_error.re_status = RPC_TIMEDOUT);

	  milliseconds = __deadline_to_ms

	    (current_time, __deadline_first (total_deadline,

					     response_deadline));

	  if (milliseconds == 0)

	    /* Per-query timeout expired.  */

	    goto send_again;

	}

      else

	{

	  /* xatgs == NULL.  Collect a response without sending a

	     query.  In this mode, we need to ignore the total

	     deadline.  */

	  milliseconds = __deadline_to_ms (current_time, response_deadline);

	  if (milliseconds == 0)

	    /* Cannot send again, so bail out.  */

	    return (cu->cu_error.re_status = RPC_CANTSEND);

	}

      switch (__poll (&fd, 1, milliseconds))

	{

	case 0:

	  if (anyup == 0)

	    {

	      anyup = is_network_up (cu->cu_sock);

	      if (!anyup)

		return (cu->cu_error.re_status = RPC_CANTRECV);

	    }

	  goto next_response;

	case -1:

	  if (errno == EINTR)

	    goto next_response;

	  cu->cu_error.re_errno = errno;

	  return (cu->cu_error.re_status = RPC_CANTRECV);

	}

#ifdef IP_RECVERR

      if (fd.revents & POLLERR)

	{

	  struct msghdr msg;

	  struct cmsghdr *cmsg;

	  struct sock_extended_err *e;

	  struct sockaddr_in err_addr;

	  struct iovec iov;

	  char *cbuf = malloc (outlen + 256);

	  int ret;

	  if (cbuf == NULL)

	    {

	      cu->cu_error.re_errno = errno;

	      return (cu->cu_error.re_status = RPC_CANTRECV);

	    }

	  iov.iov_base = cbuf + 256;

	  iov.iov_len = outlen;

	  msg.msg_name = (void *) &err_addr;

	  msg.msg_namelen = sizeof (err_addr);

	  msg.msg_iov = &iov;

	  msg.msg_iovlen = 1;

	  msg.msg_flags = 0;

	  msg.msg_control = cbuf;

	  msg.msg_controllen = 256;

	  ret = __recvmsg (cu->cu_sock, &msg, MSG_ERRQUEUE);

	  if (ret >= 0

	      && memcmp (cbuf + 256, cu->cu_outbuf, ret) == 0

	      && (msg.msg_flags & MSG_ERRQUEUE)

	      && ((msg.msg_namelen == 0

		   && ret >= 12)

		  || (msg.msg_namelen == sizeof (err_addr)

		      && err_addr.sin_family == AF_INET

		      && memcmp (&err_addr.sin_addr, &cu->cu_raddr.sin_addr,

				 sizeof (err_addr.sin_addr)) == 0

		      && err_addr.sin_port == cu->cu_raddr.sin_port)))

	    for (cmsg = CMSG_FIRSTHDR (&msg;; cmsg;

		 cmsg = CMSG_NXTHDR (&msg, cmsg))

	      if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)

		{

		  e = (struct sock_extended_err *) CMSG_DATA(cmsg);

		  cu->cu_error.re_errno = e->ee_errno;

		  free (cbuf);

		  return (cu->cu_error.re_status = RPC_CANTRECV);

		}

	  free (cbuf);

	}

#endif

      do

	{

	  fromlen = sizeof (struct sockaddr);

	  inlen = __recvfrom (cu->cu_sock, cu->cu_inbuf,

			      (int) cu->cu_recvsz, MSG_DONTWAIT,

			      (struct sockaddr *) &from, &fromlen);

	}

      while (inlen < 0 && errno == EINTR);

      if (inlen < 0)

	{

	  if (errno == EWOULDBLOCK)

	    goto next_response;

	  cu->cu_error.re_errno = errno;

	  return (cu->cu_error.re_status = RPC_CANTRECV);

	}

      /* Accept the response if the packet is sufficiently long and

	 the transaction ID matches the query (if available).  */

      if (inlen >= 4

	  && (xargs == NULL

	      || memcmp (cu->cu_inbuf, cu->cu_outbuf,

			 sizeof (uint32_t)) == 0))

	break;

    next_response:

      /* Update the current time because poll and recvmsg waited for

	 an unknown time.  */

      current_time = __deadline_current_time ();

    }

  /*

   * now decode and validate the response

   */

  xdrmem_create (&reply_xdrs, cu->cu_inbuf, (u_int) inlen, XDR_DECODE);

  ok = xdr_replymsg (&reply_xdrs, &reply_msg);

  /* XDR_DESTROY(&reply_xdrs);  save a few cycles on noop destroy */

  if (ok)

    {

      _seterr_reply (&reply_msg, &(cu->cu_error));

      if (cu->cu_error.re_status == RPC_SUCCESS)

	{

	  if (!AUTH_VALIDATE (cl->cl_auth,

			      &reply_msg.acpted_rply.ar_verf))

	    {

	      cu->cu_error.re_status = RPC_AUTHERROR;

	      cu->cu_error.re_why = AUTH_INVALIDRESP;

	    }

	  if (reply_msg.acpted_rply.ar_verf.oa_base != NULL)

	    {

	      xdrs->x_op = XDR_FREE;

	      (void) xdr_opaque_auth (xdrs, &(reply_msg.acpted_rply.ar_verf));

	    }

	}			/* end successful completion */

      else

	{

	  /* maybe our credentials need to be refreshed ... */

	  if (nrefreshes > 0 && AUTH_REFRESH (cl->cl_auth))

	    {

	      nrefreshes--;

	      goto call_again;

	    }

	}			/* end of unsuccessful completion */

    }				/* end of valid reply message */

  else

    {

      cu->cu_error.re_status = RPC_CANTDECODERES;

    }

  return cu->cu_error.re_status;

}

static void

clntudp_geterr (CLIENT *cl, struct rpc_err *errp)

{

  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  *errp = cu->cu_error;

}

static bool_t

clntudp_freeres (CLIENT *cl, xdrproc_t xdr_res, caddr_t res_ptr)

{

  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  XDR *xdrs = &(cu->cu_outxdrs);

  xdrs->x_op = XDR_FREE;

  return (*xdr_res) (xdrs, res_ptr);

}

static void

clntudp_abort (void)

{

}

static bool_t

clntudp_control (CLIENT *cl, int request, char *info)

{

  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  u_long ul;

  uint32_t ui32;

  switch (request)

    {

    case CLSET_FD_CLOSE:

      cu->cu_closeit = TRUE;

      break;

    case CLSET_FD_NCLOSE:

      cu->cu_closeit = FALSE;

      break;

    case CLSET_TIMEOUT:

      cu->cu_total = *(struct timeval *) info;

      break;

    case CLGET_TIMEOUT:

      *(struct timeval *) info = cu->cu_total;

      break;

    case CLSET_RETRY_TIMEOUT:

      cu->cu_wait = *(struct timeval *) info;

      break;

    case CLGET_RETRY_TIMEOUT:

      *(struct timeval *) info = cu->cu_wait;

      break;

    case CLGET_SERVER_ADDR:

      *(struct sockaddr_in *) info = cu->cu_raddr;

      break;

    case CLGET_FD:

      *(int *)info = cu->cu_sock;

      break;

    case CLGET_XID:

      /*

       * use the knowledge that xid is the

       * first element in the call structure *.

       * This will get the xid of the PREVIOUS call

       */

      memcpy (&ui32, cu->cu_outbuf, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_XID:

      /* This will set the xid of the NEXT call */

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul - 1);

      memcpy (cu->cu_outbuf, &ui32, sizeof (ui32));

      /* decrement by 1 as clntudp_call() increments once */

      break;

    case CLGET_VERS:

      /*

       * This RELIES on the information that, in the call body,

       * the version number field is the fifth field from the

       * beginning of the RPC header. MUST be changed if the

       * call_struct is changed

       */

      memcpy (&ui32, cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_VERS:

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul);

      memcpy (cu->cu_outbuf + 4 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));

      break;

    case CLGET_PROG:

      /*

       * This RELIES on the information that, in the call body,

       * the program number field is the  field from the

       * beginning of the RPC header. MUST be changed if the

       * call_struct is changed

       */

      memcpy (&ui32, cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT, sizeof (ui32));

      ul = ntohl (ui32);

      memcpy (info, &ul, sizeof (ul));

      break;

    case CLSET_PROG:

      memcpy (&ul, info, sizeof (ul));

      ui32 = htonl (ul);

      memcpy (cu->cu_outbuf + 3 * BYTES_PER_XDR_UNIT, &ui32, sizeof (ui32));

      break;

    /* The following are only possible with TI-RPC */

    case CLGET_SVC_ADDR:

    case CLSET_SVC_ADDR:

    case CLSET_PUSH_TIMOD:

    case CLSET_POP_TIMOD:

    default:

      return FALSE;

    }

  return TRUE;

}

static void

clntudp_destroy (CLIENT *cl)

{

  struct cu_data *cu = (struct cu_data *) cl->cl_private;

  if (cu->cu_closeit)

    {

      (void) __close (cu->cu_sock);

    }

  XDR_DESTROY (&(cu->cu_outxdrs));

  mem_free ((caddr_t) cu, (sizeof (*cu) + cu->cu_sendsz + cu->cu_recvsz));

  mem_free ((caddr_t) cl, sizeof (CLIENT));

}