This chapter is for RPC programmers. It documents the port mapper routines in the ONC RPC Run-Time Library (RTL). These routines are the programming interface to ONC RPC.
Port Mapper routines provide a simple callable interface to the Port Mapper. They allow you to request Port Mapper services and information about port mappings. The below table summarizes the purpose of each Port Mapper routine.
|
Routine |
Purpose |
|
pmap_freemaps |
Frees memory that was allocated by the pmap_getmaps() routine. |
|
pmap_getmaps |
Returns a list of Port Mappings for the specified host. |
|
pmap_getport |
Returns the port number on which a specified service is waiting. |
|
pmap_rmtcall |
Requests the Port Mapper on a remote host to call a procedure on that host. |
|
pmap_set |
Registers a remote service with a remote port. |
|
pmap_unset |
Unregisters a service so it is no longer mapped to a port. |
Port Mapper routines use many of the same arguments as client routines.
See the table in the first section of the ONC RPC RTL Client Routines chapter for a list of these arguments.
The following sections describe each Port Mapper routine in detail.
Frees memory that was allocated by the pmap_getmaps routine.
void pmap_freemaps(struct pmaplist *list);
list
Address of a structure containing the list returned by the pmap_getmaps routine.
Call the pmap_freemaps routine when the list returned by pmap_getmaps is no longer needed. Do not call pmap_freemaps to free a list that you created.
Returns a list of port mappings for the specified host.
struct pmaplist *pmap_getmaps(struct sockaddr_in *addr);
addr
Address of a structure containing the internet address of the host whose Port Mapper is being called.
The pmap_getmaps routine returns a list of current RPC server-to-Port Mappings on the host at addr. The list structure is defined in the PMAP_PROT.H file.
The RPCINFO command uses this routine.
If an error occurs (for example, pmap_getmaps cannot get a list of Port Mappings, the internet address is invalid, or the remote Port Mapper does not exist), the routine returns either NULL or the address of the list.
Returns the port number on which a specified service is waiting.
u_short pmap_getport(struct sockaddr_in *addr, u_long prognum, u_long versnum, u_long protocol);
addr
Address of a structure containing the internet address of the remote host on which the server resides.
prognum, versnum, protocol
See the Common Arguments section in the ONC RPC RTL Client Routines chapter for a list of these arguments.
If the requested mapping does not exist or the routine fails to contact the remote Port Mapper, the routine returns either the port number or zero.
The pmap_getport routine uses the global variable rpc_createerr. rpc_createerr is a structure that contains the most recent service creation error. Use rpc_createerr if you want the service program to handle the error. The value of rpc_createerr is set by any RPC server creation routine that does not succeed.
The rpc_createerr variable is defined in the CLNT.H file.
Requests the Port Mapper on a remote host to call a procedure on that host.
enum clnt_stat pmap_rmtcall(struct sockaddr_in *addr, u_long prognum, u_long versnum, u_long procnum, xdrproc_t inproc, u_char *in, xdrproc_t outproc, u_char *out, struct timeval tout, u_long *portp);
addr
Address of a structure containing the internet address of the remote host on which the server resides.
prognum, versnum, procnum, inproc, in, outproc, out
See the Common Arguments section in the ONC RPC RTL Client Routines chapter for a list of these arguments.
tout
Time allowed for the results to return to the client, in seconds and microseconds.
portp
Address where pmap_rmtcall will write the port number of the remote service.
The pmap_rmtcall routine allows you to get a port number and call a remote procedure in one call. The routine requests a remote Port Mapper to call a prognum, versnum, and procnum on the Port Mapper's host. The remote procedure call uses the UDP transport.
If pmap_rmtcall succeeds, it changes portp to contain the port number of the remote service.
After calling the pmap_rmtcall routine, you may call the clnt_perrno routine.
The TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC]GETSYI_CLNT_RMTCALL.C file provides a sample program using pmap_rmtcall.
This routine returns diagnostic values defined in the CLNT.H file for enumclnt_stat.
Registers a remote service with a remote port.
bool_t pmap_set(u_long prognum, u_long versnum, u_long protocol, u_short port);
prognum, versnum, protocol
See the Common Arguments section in the ONC RPC RTL Client Routines chapter for a list of these arguments.
port
Remote port number.
The pmap_set routine calls the local Port Mapper to tell it which port and protocol the prognum, versnum is using.
You are not likely to use pmap_set, because svc_register calls it.
The pmap_set routine returns TRUE if it succeeds, and FALSE if it fails.
Unregisters a service so it is no longer mapped it to a port.
bool_t pmap_unset(u_long prognum, u_long versnum);
prognum, versnum
See the Common Arguments section in the ONC RPC RTL Client Routines chapter for a list of these arguments.
The pmap_unset routine calls the local Port Mapper and, for all protocols, removes the prognum and versnum from the list that maps servers to ports.
You are not likely to use pmap_unset, because svc_unregister calls it.
The GETSYI_PROC_A.C and GETSYI_SVC.C files provide sample programs using the pmap_unset routine.
These files are in the TCPWARE_ROOT:[TCPWARE.EXAMPLES.RPC] directory.
The pmap_unset routine returns TRUE if it succeeds, FALSE if it fails.