## TCPware V5.7 Programmer's Guide

- Introduction
- Server Routines
- Routine Descriptions

Chapter 18

ONC RPC RTL Server Routines

# Introduction

This chapter is for RPC programmers. It documents the server routines in the ONC RPC Run-Time Library (RTL). These routines are the programming interface to ONC RPC.

# Server Routines

The server routines are called by the server program or the server stub procedures. Table 18-1 lists each server routine and summarizes its purpose.

Table 18-1 Server Routines (Continued)

XDR and ONC Routines | Purpose
registerrpc | Performs creation and registration tasks for server.
svc_destroy | Macro that destroys RPC server handle.
svc_freeargs | Macro that frees memory allocated when RPC arguments were decoded.
svc_getargs | Macro that decodes RPC arguments.
svc_getcaller | Macro that returns address of client that called server.
svc_getchan | Macro that returns channel of server handle.
svc_getport | Macro that returns port associated with server handle.
svc_getreqset | Reads data for each server connection.
svc_register | Adds specified server to list of active servers, and registers service program with Port Mapper.
svc_run | Waits for RPC requests and calls svc_getreqset routine to dispatch to appropriate RPC service program.
svc_sendreply | Sends results of remote procedure call to client.
svc_unregister | Calls Port Mapper to unregister specified program and version for all protocols.
svcerr_auth | Sends error code when server cannot authenticate client.
svcerr_decode | Sends error code to client if server cannot decode arguments.
svcerr_noproc | Sends error code to client if server cannot implement requested procedure.
svcerr_noprog | Sends error code to client when requested program is not registered with Port Mapper.
svcerr_progvers | Sends error code to client when requested program is registered with Port Mapper, but requested version is not registered.
svcerr_systemerr | Sends error code to client when server encounters error not handled by particular protocol.
svcerr_weakauth | Sends error code to client when server cannot perform remote procedure call because it received insufficient (but correct) authentication parameters.
svcfd_create | Returns address of structure containing server handle for specified TCP socket.
svctcp_create | Returns address of server handle that uses TCP transport.

ONC Routine | Purpose
svctcpa_create | Returns address of server handle that uses TCPA transport.
svctcpa_enablecache | Enables XID cache for specified TCPA transport server.
svctcpa_freecache | Deallocates TCPA XID cache.
svctcpa_getxdrs | Returns XDR structure associated with server handle.
svctcpa_shutdown | Cancels all outstanding I/O on channel associated with server handle.

XDR ONC Routine | Purpose
svcudp_bufcreate | Returns address of server handle that uses UDP transport. For procedures that pass messages longer than 8Kbytes.
svcudp_create | Returns address of server handle that uses UDP transport. For procedures that pass messages shorter than 8Kbytes.
svcudp_enablecache | Enables XID cache for specified UDP transport server.

ONC Routine | Purpose
svcudpa_bufcreate | Returns address of server handle that uses UDPA transport. For procedures that pass messages longer than 8Kbytes.
svcudpa_create | Returns address of server handle that uses UDPA transport. For procedures that pass messages shorter than 8Kbytes.
svcudpa_enablecache | Enables XID cache for specified UDPA transport server.
svcudpa_freecache | Deallocates UDPA XID cache.
svcudpa_getxdrs | Returns XDR structure associated with server handle.
svcudpa_shutdown | Cancels all outstanding I/O on channel associated with the server handle.

XDR ONC Routine | Purpose
xprt_register | Adds UDP or TCP server socket to list of sockets.
xprt_unregister | Removes UDP or TCP server socket from list of sockets.

# Routine Descriptions

The following sections describe each server routine in detail.

registerrpc

XDR ONC Performs creation and registration tasks for the server.

Format

#include
int registerrpc (u_long prognum, u_long versnum, u_long procnum,
u_char *(*procname) (), xdrproc_t inproc, xdrproc_t outproc);

Arguments

prognum, versnum, procnum, inproc, outproc

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

procname

Address of the routine that implements the service procedure. The routine uses the following format:

u_char *procname(out);
u_char *out;

where out is the address of the data decoded by outproc.

Description

The registerrpc routine performs the following tasks for a server:

• Creates a UDP server handle.

• Calls the svc_register routine to register the program with the Port Mapper.

• Adds prognum, versnum, and procnum to an internal list of registered procedures. When the server receives a request, it uses this list to determine which routine to call.

A server should call registerrpc for every procedure it implements, except for the NULL procedure.

Example

The GETSYI_SVC_REG.C file provide a sample program using the registerrpc routine. This file is in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

The registerrpc routine returns zero if it succeeds, and -1 if it fails.

See Also

svc_register

svc_destroy

ONC Macro that destroys the RPC server handle.

Format

void svc_destroy (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

The svc_destroy routine destroys xprt by deallocating private data structures. After this call, xprt is undefined.

If the server creation routine received RPC_ANYSOCK as the socket, svc_destroy closes the socket. Otherwise, you must close the socket.

Example

The TCPWARE_ROOT[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file provides a sample program using the svc_destroy routine.

See Also

svcfd_create, svctcp_create, svcudp_create

svc_freeargs

ONC Macro that frees the memory that was allocated when the RPC arguments were decoded.

Format

bool_t svc_freeargs (SVCXPRT *xprt, xdrproc_t xdr_args,
char *args_ptr);

Arguments

x prt, xdr_args, args_ptr

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

Description

The svc_freeargs routine calls the xdr_free routine.

Example

The GETSYI_PROC_A.C and GETSYI_SVC.C files provide sample programs that use the svc_freeargs routine. These files are in the TCPWARE:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

This routine returns TRUE if it succeeds and FALSE if it fails.

See Also

svc_getargs, xdr_free

svc_getargs

ONC Macro that decodes the RPC arguments.

Format

bool_t svc_getargs (SVCXPRT *xprt, xdrproc_t xdr_args,
u_char *args_ptr);

Arguments

xprt, xdr_args, args_ptr

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

Example

The GETSYI_PROC_A.C and GETSYI_SVC.C files provide sample programs that use the svc_getargs routine.

These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

This routine returns TRUE if it succeeds and FALSE if it fails.

See Also

svc_freeargs

svc_getcaller

ONC Macro that returns the address of the client that called the server.

Format

struct sockaddr_in *svc_getcaller (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

svc_getchan

ONC Macro that returns the channel associated with the server handle.

Format

u_short svc_getchan (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

Use svc_getchan when multiple servers are listening on the same channel and port.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file provides a sample program that uses svc_getchan.

svc_getport

ONC Macro that returns the port associated with the server handle.

Format

u_short svc_getport (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

Use svc_getport when you want to know what port the server is listening on. You can use this macro with synchronous and asynchronous transports.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file provides a sample program that uses svc_getport.

svc_getreqset

XDR ONC Reads data for each server connection.

Format

#include

void svc_getreqset (int rdfds);

Argument

rdfds

Address of the read socket descriptor array. This array is returned by the select routine.

Description

The server calls svc_getreqset when it receives an RPC request. The svc_getreqset routine reads in data for each server connection, then calls the server program to handle the data.

The svc_getreqset routine does not return a value. It finishes executing after all rdfds sockets have been serviced.

You are unlikely to call this routine directly, because the svc_run routine calls it. However, there are times when you cannot call svc_run. For example, suppose a program services RPC requests and reads or writes to another socket at the same time. The program cannot call svc_run. It must call select and svc_getreqset.

The svc_getreqset routine is for servers that implement custom asynchronous event processing, do not use the svc_run routine.

You may use the global variable svc_fdset with svc_getreqset. The svc_fdset variable lists all sockets the server is using. It contains an array of structures, where each element is a socket pointer and a service handle. It uses the following format:

struct sockarr svc_fdset [MAXSOCK +1];

This is how to use svc_fdset: first, copy the socket handles from svc_fdset into a temporary array that ends with a zero. Pass the array to the select routine. The select routine overwrites the array and returns it. Pass this array to the svc_getreqset routine.

You may use svc_fdset when the server does not use svc_run.

The svc_fdset variable is not compatible with UNIX.

Example

#define MAXSOCK 10
int readfds[ MAXSOCK+1], /* sockets to select from */
i, j;
for( i = 0, j = 0; i < MAXSOCK; i++)
if( (svc_fdset[i].sockname != 0) && (svc_fdset[i].sockname !=
1))
readfds[j++] = svc_fdset[i].sockname;
readfds[j] = 0; /* list of sockets ends w/ a zero */
switch( select( 0, readfds, 0, 0, 0))
{
case -1: /* an error happened */
case 0: /* time out */
break;
default: /* 1 or more sockets ready for reading */
errno = 0;
ONCRPC_SVC_GET_REQSET( readfds);
if( errno == ENETDOWN || errno == ENOTCONN)
sys$exit( SS$_THIRDPARTY);
}

See Also

svc_run

svc_register

XDR ONC Adds the specified server to a list of active servers, and registers the service program with the Port Mapper.

Format

#include

bool_t svc_register (SVCXPRT *xprt, u_long prognum,
u_long versnum, void (*dispatch) (), u_long protocol);

Arguments

xprt, prognum, versnum

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

dispatch

Routine that svc_register calls when the server receives a request for prognum, versnum. This routine determines which routine to call for each server procedure. This routine uses the following form:

void dispatch(request, xprt)

struct svc_req *request;

SVCXPRT *xprt;

The svc_getreqset and svc_run routines call dispatch.

protocol

Must be IPPROTO_UDP, IPPROTO_TCP, or zero. Zero indicates that you do not want to register the server with the Port Mapper.

Example

The GETSYI_PROC_A.C and GETSYI_SVC.C files provide sample programs that use the svc_register routine.

These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

The svc_register routine returns TRUE if it succeeds and FALSE if it fails.

See Also

pmap_set, svc_getreqset, svc_unregister

svc_run

XDR ONC Waits for RPC requests and calls the svc_getreqset routine to dispatch to the appropriate RPC service program.

Format

#include

void svc_run()

Arguments

None.

Description

The svc_run routine calls the select routine to wait for RPC requests. When a request arrives, svc_run calls the svc_getreqset routine. Then svc_run calls select again.

The svc_run routine never returns.

You may use the global variable svc_fdset with svc_run. See the svc_getreqset routine for more information on svc_fdset.

Examples

These files contain sample programs that use svc_run:

• GETSYI_SVC.C

• GETSYI_SVC_REG.C

• PRINT_SVC.C

• SYSINFO_SVC.C

These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

See Also

svc_getreqset

svc_sendreply / svc_sendreply_dq

Sends the results of a remote procedure call to the client.

Format

XDR ONC

#include
bool_t svc_sendreply (SVCXPRT *xprt, xdrproc_t outproc, u_char *out);

ONC

bool_t svc_sendreply_dq (SVCXPRT *xprt, xdrproc_t outproc, u_char *out);

Arguments

XDR ONC

xprt, outproc, out

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

Description

Both routines send the results of a remote procedure call to the client.

The svc_sendreply_dq routine, however, does not queue a read and is for UDPA and TCPA servers only.

Examples

These files contain sample programs that use svc_sendreply:

• SYSINFO_SVC.C

• PRINT_SVC.C

• GETSYI_PROC_A.C

• GETSYI_SVC.C

These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

These routines returns TRUE if they succeed and FALSE if they fail.

svc_unregister

XDR ONC Calls the Port Mapper to unregister the specified program and version for all protocols. The program and version are removed from the list of active servers.

Format

#include

void svc_unregister (u_long prognum, u_long versnum);

Arguments

prognum, versnum

See Table 16-1 in the ONC RPC RTL Client Routines chapter for a list of these arguments.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file contains a sample program that uses the svc_unregister routine.

See Also

pmap_unset, svc_register

svcerr_auth

svcerr_decode
svcerr_noproc
svcerr_noprog
svcerr_progvers
svcerr_systemerr
svcerr_weakauth

XDR ONC Sends various error codes to the client process.

Format

#include

void svcerr_auth (SVCXPRT *xprt, enum auth_stat why);
void svcerr_decode (SVCXPRT *xprt);
void svcerr_noproc (SVCXPRT *xprt);
void svcerr_noprog (SVCXPRT *xprt);
void svcerr_progvers (SVCXPRT *xprt, u_long low-vers, u_long high-vers);
void svcerr_systemerr (SVCXPRT *xprt);
void svcerr_weakauth (SVCXPRT *xprt);

Arguments

xprt

RPC server handle.

why

Error code defined in the AUTH.H file.

low-vers

Lowest version number in the range of versions that the server supports.

high-vers

Highest version in the range of versions that the server supports.

Description

svcerr_auth

See svc_getreqset. Calls svcerr_auth when it cannot authenticate a client. The svcerr_auth routine returns an error code (why) to the caller.

svcerr_decode

Sends an error code to the client if the server cannot decode the arguments.

svcerr_noproc

Sends an error code to the client if the server does not implement the requested procedure.

svcerr_noprog

Sends an error code to the client when the requested program is not registered with the Port Mapper. Generally, the Port Mapper informs the client when a server is not registered. Therefore, the server is unlikely to use this routine.

svcerr_progvers

Sends an error code to the client when the requested program is registered with the Port Mapper, but the requested version is not registered.

svcerr_systemerr

Sends an error code to the client when the server encounters an error that is not handled by a particular protocol.

svcerr_weakauth

Sends an error code to the client when the server cannot perform a remote procedure call because it received insufficient (but correct) authentication parameters. This routine calls the svcerr_auth routine. The value of why is AUTH_TOOWEAK, which means "access permission denied."

svcfd_create

XDR ONC Returns the address of a structure containing a server handle for the specified TCP socket.

Format

#include

SVCXPRT *svcfd_create (int sock, u_long sendsize, u_long recvsize);

Arguments

sock

Socket number. Do not specify a file descriptor.

sendsize

Size of the send buffer. If you enter a value less than 100, then 4000 is used as the default.

recvsize

Size of the receive buffer. If you enter a value less than 100, then 4000 is used as the default.

Description

The svcfd_create routine returns the address of a server handle for the specified TCP socket. This handle cannot use a file. The server calls the svcfd_create routine after it accepts a TCP connection.

Diagnostics

This routine returns zero if it fails.

See Also

svctcp_create

svcraw_create

XDR Creates a server handle for memory-based Sun RPC for simple testing and timing.

Format

#include

SVCXPRT svcraw_create ();

Argument

None.

Description

The svcraw_create routine creates a toy Sun RPC service transport, to which it returns a pointer. The transport is really a buffer within the process's address space, so the corresponding client should live in the same address space.

This routine allows simulation of and acquisition of Sun RPC overheads (such as round trip times) without any kernel interference.

Diagnostics

This routine returns NULL if it fails.

See Also

clntraw_create

svctcp_create

XDR ONC Returns the address of a server handle that uses the TCP transport.

Format

#include

SVCXPRT *svctcp_create (int sock, u_long sendsize, u_long recvsize);

Arguments

sock

Socket for this service. The svctcp_create routine creates a new socket if you enter RPC_ANYSOCK. If the socket is not bound to a TCP port, svctcp_create binds it to an arbitrary port.

sendsize

Size of the send buffer. If you enter a value less than 100, then 4000 bytes is used as the default.

recvsize

Size of the receive buffer. If you enter a value less than 100, then 4000 bytes is used as the default.

Examples

The PRINT_SVC.C and GETSYI_SVC.C files provides sample programs that use svctcp_create. These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

The svctcp_create routine returns either the address of the server handle, or zero (if it could not create the server handle).

See Also

svcfd_create, svc_destroy

svctcpa_create

ONC Returns the address of a server handle that uses the TCPA transport.

Format

SVCXPRT *svctcpa_create (u_short channel, u_short port, u_long sendsize, u_long recvsize);

Arguments

channel

If you enter RPC_ANYCHAN (defined in the SVC.H file), the svctcpa_create routine assigns a channel and sets the local port to the port value. If you enter any other value, svctcpa_create ignores the port value.

Multiple server handles may use the same channel if you specify RPC_ANYCHAN and a port number on the first call to svctcpa_create, and if you specify the assigned channel with any port number on subsequent calls to svctcpa_create. (Use svc_getchan to obtain the channel. Note that for TCPA, this is really not a channel, just a unique identifier.)

All server handles that use the same channel should use the same XID cache.

port

Number of the TCP port on which the server will listen. If you enter RPCANYPORT, then RPC assigns a port.

sendsize

Size of the send buffer. If you enter a value less than 100, then 4000 bytes is used as the default.

recvsize

Size of the receive buffer. If you enter a value less than 100, then 4000 bytes is used as the default.

Examples

The GETSYI_PROC_A.C file contains a sample program that uses svctcpa_create. This file is in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

The svctcpa_create routine returns either the address of the server handle, or zero (if it could not create the server handle).

See Also

svc_destroy, svctcp_create, svctcpa_shutdown, svcudpa_create

svctcpa_enablecache

ONC Enables the XID cache for the specified TCPA transport server.

Format

void *svctcpa_enablecache (SVCXPRT *xprt, void *cacheaddr, u_long size, reply_id *reqlst);

Arguments

xprt

RPC server handle.

cacheaddr

Address of the XID cache. If cacheaddr is zero, this routine allocates a cache with size number of entries. All TCPA transports that use this cache must have the same size buffers. The first time you call svctcpa_enablecache, specify zero as the cacheaddr. The second time you call svctcpa_enablecache, specify the address that svctcpa_enablecache returned on the previous call as the cacheaddr. All server handles that use a channel should use the same XID cache.

size

Number of entries in the cache. You may estimate this number based on how active the server is, and on how long you want to retain old replies.

reqlst

Address of an array of structures containing a list of procedures for which replies are to be cached. The array is terminated by prognum==0. This is the structure:

typedef struct
{
u_long prognum,
versnum,
procnum;
} reply_id

If this address is zero, the server saves all replies in the XID cache.

Description

Call the svctcpa_enablecache routine after each TCPA server handle is created. The server places all appropriate outgoing responses in the XID cache. The cache can be used to improve the performance of the server, for example, by preventing the server from recalculating the results or sending incorrect results. You can disable the cache by calling the svctcpa_freecache routine. The ONC RPC Fundamentals, Chapter 12, provides more information on the XID cache.

Diagnostics

The svctcpa_enablecache routine returns either the address of the cache, or zero if an error occurs.

See Also

svctcpa_create, svctcpa_freecache

svctcpa_freecache

ONC Deallocates the TCPA XID cache.

Format

void svctcpa_freecache (void *cacheaddr);

Argument

cacheaddr

Address of the TCPA XID cache.

Description

The svc_destroy routine calls the svctcpa_freecache routine for every server handle, after all servers that reference the cache have been destroyed.

The ONC RPC Fundamentals, Chapter 12, provides more information on the XID cache.

See Also

svc_destroy, svctcpa_enablecache

svctcpa_getxdrs

ONC Returns the XDR structure associated with the server handle.

Format

XDRS *svctcpa_getxdrs (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

svctcpa_shutdown

ONC Cancels all outstanding I/O on the channel associated with the server handle.

Format

void svctcpa_shutdown (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

The svctcpa_shutdown routine cancels all I/O on the channel associated with xprt and flags the server as shutting down. The server then begins the shutdown process. Call this routine only once for a channel before calling svc_destroy to destroy individual server handles.

This routine affects all TCPA handles that are using the same channel.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file contains a sample program that uses svctcpa_shutdown.

See Also

svc_destroy, svctcpa_create

svcudp_create / svcudp_bufcreate

XDR ONC Returns the address of a server handle that uses the UDP transport.

Format

#include

SVCXPRT *svcudp_create (int sock);

SVCXPRT *svcudp_bufcreate (int sock, u_long sendsize,
u_long recvsize);

Arguments

sock

Socket for this service. The svcudp_create routine creates a new socket if you enter RPC_ANYSOCK. If the socket is not bound to a UDP port, the svcudp_create routine binds it to an arbitrary port.

sendsize

Size of the send buffer. The minimum size is 100 bytes. The maximum size is 65468, the maximum UDP packet size. If you enter a value less than 100, then 4000 is used as the default.

recvsize

Size of the receive buffer. The minimum size is 100 bytes. The maximum size is 65000, the maximum UDP packet size. If you enter a value less than 100, then 4000 is used as the default.

Description

Use the svc_create routine only for procedures that pass messages shorter than 8Kbytes long. Use the svcudp_bufcreate routine for procedures that pass messages longer than 8Kbytes.

Examples

The SYSINFO_SVC.C and GETSYI_SVC.C files contain sample programs that use svcudp_create. These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.

Diagnostics

These routines return either a server handle, or zero (if they could not create the server handle).

See Also

svc_destroy, svcudp_enablecache

svcudp_enablecache

XDR ONC Enables the XID cache for the specified UDP transport server.

Format

bool_t svcudp_enablecache (SVCXPRT *xprt, u_long size);

Arguments

xprt

RPC server handle.

size

Number of entries permitted in the XID cache. You may estimate this number based on how active the server is, and on how long you want to retain old replies.

Description

Use the svcudp_enablecache routine after a UDP server handle is created. The server places all outgoing responses in the XID cache. The cache can be used to improve the performance of the server, for example, by preventing the server from recalculating the results or sending incorrect results.

You cannot disable the XID cache for UDP servers.

The ONC RPC Fundamentals, Chapter 12, provides more information on the XID cache.

Example

#define FALSE 0
#define UDP_CACHE_SIZE 10
SVCXPRT *udp_xprt;
udp_xprt = svcudp_create( RPC_ANYSOCK);
if( svcudp_enablecache( udp_xprts, UDP_CACHE_SIZE) == FALSE)
printf( "XID cache was not enabled");
else
printf( "XID cache was enabled");

Diagnostics

This routine returns TRUE if it enables the XID cache, and FALSE if the cache was previously enabled or an error occurs.

svcudpa_create / svcudpa_bufcreate

ONC Returns the address of a server handle that uses the UDPA transport.

Format

SVCXPRT *svcudpa_create (u_short channel, u_short port);

SVCXPRT *svcudpa_bufcreate (u_short channel, u_short port, u_long sendsize, u_long recvsize);

Arguments

channel

If you enter RPC_ANYCHAN (defined in the SVC.H file), then the svcudpa_bufcreate routine assigns the channel and sets the local port to the port value. If you enter any other value, then svcudpa_bufcreate ignores the port value. Multiple server handles may use the same channel if you specify RPC_ANYCHAN and a port number on the first call to svcudpa_create, and if you specify the assigned channel with any port number on subsequent calls to svcudpa_create. All server handles that use the same channel should use the same XID cache.

port

Number of the UDP port on which the server will listen. All servers that use the same port should use the same channel. If you enter RPCANYPORT, then RPC assigns the port.

sendsize

Size of the send buffer. If you enter a value less than 100, then 4000 is used as the default.

recvsize

Size of the receive buffer. If you enter a value less than 100, then 4000 is used as the default.

Description

Both routines return the address of a structure containing a UDPA server handle. The svcudpa_create routine limits the call to 8Kbytes of data. The svcudpa_bufcreate routine allows you to define the buffer sizes.

See Using Asynchronous Transports in Chapter 13, Building Distributed Applications with RPC, for more information on writing asynchronous transports.

Example

TCPWARE_ROOT:[TCPWARE.EXAMPLE].RPC]GETSYI_PROC_A.C provides a sample program and procedure that use svcudpa_create.

Diagnostics

These routines return the address of the server handle, or zero (if they could not create the server handle).

See Also

svc_destroy, svcudpa_enablecache, svcudpa_shutdown

svcudpa_enablecache

ONC Enables the XID cache for the specified UDPA transport server.

Format

void *svcudpa_enablecache (SVCXPRT *xprt, void *cacheaddr, u_long size, reply_id *reqlst);

Arguments

xprt

RPC server handle.

cacheaddr

Address of the XID cache. If cacheaddr is zero, this routine allocates a cache with size number of entries. All UDPA transports that use this cache must have the same size buffers.

The first time you call svcudpa_enablecache, specify zero as the cacheaddr. The second time you call svcudpa_enablecache, specify the address that svcudpa_enablecache returned on the previous call as the cacheaddr.

All server handles that use a channel should use the same XID cache.

size

Number of entries in the cache. You may estimate this number based on how active the server is, and on how long you want to retain old replies.

reqlst

Address of an array of structures containing a list of procedures for which replies are to be cached. The array is terminated by prognum==0. This is the structure:

typedef struct
{
u_long prognum,
versnum,
procnum;
} reply_id

If this address is zero, the server saves all replies in the XID cache.

Description

Call the svcudpa_enablecache routine after each UDPA server handle is created. The server places all appropriate outgoing responses in the XID cache.

The cache can be used to improve the performance of the server, for example, by preventing the server from recalculating the results or sending incorrect results. You can disable the cache by calling the svcudpa_freecache routine.

The ONC RPC Fundamentals, Chapter 12, provides more information on the XID cache.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file contains a sample program that uses the svcudpa_enablecache routine.

Diagnostics

The svcudpa_enablecache routine returns either the address of the cache, or zero if an error occurs.

See Also

svcudpa_create, svcudpa_freecache

svcudpa_freecache

ONC Deallocates the UDPA XID cache.

Format

void svcudpa_freecache (void *cacheaddr);

Argument

cacheaddr

Address of the UDPA XID cache.

Description

The svc_destroy routine calls the svcudpa_freecache routine for every server handle, after all servers that reference the cache have been destroyed.

The ONC RPC Fundamentals, Chapter 12, provides more information on the XID cache.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file contains a sample program that uses svcudpa_freecache.

See Also

svc_destroy, svcudpa_enablecache

svcudpa_getxdrs

ONC Returns the XDR structure associated with the server handle.

Format

XDRS *svcudpa_getxdrs (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

svcudpa_shutdown

ONC Cancels all outstanding I/O on the channel that is associated with the server handle.

Format

void svcudpa_shutdown (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

The svcudpa_shutdown routine cancels all I/O on the channel associated with xprt and flags the server as shutting down. The server then begins the shutdown process. Call this routine only once for a channel, before calling svc_destroy to destroy individual servers.

This routine affects all UDPA handles that are using the same channel.

Example

The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_PROC_A.C file contains a sample program that uses svcudpa_shutdown.

See Also

svc_destroy, svcudpa_create

xprt_register

XDR ONC Adds a TCP or UDP server socket to a list of sockets.

Format

#include

void xprt_register (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

The xprt_register and xprt_unregister routines maintain a list of sockets. This list ensures that the correct server is called to process the request. The xprt_register routine adds the server socket to the svc_fdset variable, which also stores the server handle that is associated with the socket. The svc_run routine passes the list of sockets to the select routine. The select routine returns to svc_run a list of sockets that have outstanding requests.

You are unlikely to call this routine directly because svc_register calls it.

See Also

svc_register, xprt_unregister

xprt_unregister

XDR ONC Removes a TCP or UDP server socket from a list of sockets.

Format

#include

void xprt_unregister (SVCXPRT *xprt);

Argument

xprt

RPC server handle.

Description

This list of sockets ensures that the correct server is called to process the request. See the xprt_register routine for a description of how this list is maintained.

You are unlikely to call this routine directly because svc_unregister calls it.

See Also

svc_unregister, xprt_register