These routines are part of the RPC library which allows C language programs to make procedure calls on servers across the network. These routines deal with the creation of service handles. Once the handle is created, the server can be invoked by calling svc_run().
Routines
See rpc(3NSL) for the definition of the SVCXPRT data structure.
svc_control()
A function to change or retrieve information about a service object. req indicates the type of operation and info is a pointer to the information. The supported values of req, their argument types,
and what they do are:
SVCGET_VERSQUIET
If a request is received for a program number served by this server but the version number is outside the range registered with the server, an RPC_PROGVERSMISMATCH error will normally be returned. info should be a pointer to an integer.
Upon successful completion of the SVCGET_VERSQUIET request, *info contains an integer which describes the server's current behavior: 0 indicates normal server behavior, that is, an RPC_PROGVERSMISMATCH error
will be returned. 1 indicates that the out of range request will be silently ignored.
SVCSET_VERSQUIET
If a request is received for a program number served by this server but the version number is outside the range registered with the server, an RPC_PROGVERSMISMATCH error will normally be returned. It is sometimes desirable to change this behavior. info should be a pointer to an integer which is either 0, indicating normal server behavior and an RPC_PROGVERSMISMATCH error will be returned, or 1, indicating that the out of range request should be silently ignored.
SVCGET_XID
Returns the transaction ID of connection-oriented and connectionless transport service calls. The transaction ID assists in uniquely identifying client requests for a given RPC version, program number, procedure,
and client. The transaction ID is extracted from the service transport handle svc. info must be a pointer to an unsigned long. Upon successful completion of the SVCGET_XID request, *info contains
the transaction ID. Note that rendezvous and raw service handles do not define a transaction ID. Thus, if the service handle is of rendezvous or raw type, and the request is of type SVCGET_XID,svc_control() will return FALSE. Note also that the transaction ID read by the server can be set by the client through the suboption CLSET_XID in clnt_control(). See clnt_create(3NSL)
SVCSET_RECVERRHANDLER
Attaches or detaches a disconnection handler to the service handle, svc, that will be called when a transport error arrives during the reception of a request or when the server is waiting for a request and the connection shuts down. This handler is only
useful for a connection oriented service handle.
*info contains the address of the error handler to attach, or NULL to detach a previously defined one. The error handler has two arguments. It has a pointer to the erroneous service handle. It also has an integer that indicates if the
full service is closed (when equal to zero), or that only one connection on this service is closed (when not equal to zero).
With the service handle address, svc, the error handler is able to detect which connection has failed and to begin an error recovery process. The error handler can be called by multiple threads and should be implemented in an MT-safe way.
SVCGET_RECVERRHANDLER
Upon successful completion of the SVCGET_RECVERRHANDLER request, *info contains the address of the handler for receiving errors. Upon failure, *info contains NULL.
SVCSET_CONNMAXREC
Set the maximum record size (in bytes) and enable non-blocking mode for this service handle. Value can be set and read for both connection and non-connection oriented transports, but is silently ignored for the non-connection oriented case. The info argument
should be a pointer to an int.
SVCGET_CONNMAXREC
Get the maximum record size for this service handle. Zero means no maximum in effect and the connection is in blocking mode. The result is not significant for non-connection oriented transports. The info argument should be a pointer to an int.
This routine returns TRUE if the operation was successful. Otherwise, it returns false.
svc_create()
svc_create() creates server handles for all the transports belonging to the class nettype.
nettype defines a class of transports which can be used for a particular application. The transports are tried in left to right order in NETPATH variable or in top to bottom order in the netconfig database. If nettype is NULL, it defaults to netpath.
svc_create() registers itself with the rpcbind service (see rpcbind(1M)). dispatch is
called when there is a remote procedure call for the given prognum and versnum; this requires calling svc_run() (see svc_run() in rpc_svc_reg(3NSL)). If svc_create() succeeds, it returns the number of server handles it created, otherwise it returns 0 and an error message is logged.
svc_destroy()
A function macro that destroys the RPC service handle xprt. Destruction usually involves deallocation of private data structures, including xprt itself. Use of xprt is undefined
after calling this routine.
svc_dg_create()
This routine creates a connectionless RPC service handle, and returns a pointer to it. This routine returns NULL if it fails, and an error message is logged. sendsz and recvsz are
parameters used to specify the size of the buffers. If they are 0, suitable defaults are chosen. The file descriptor fildes should be open and bound. The server is not registered with rpcbind(1M).
Warning: since connectionless-based RPC messages can only hold limited amount of encoded data, this transport cannot be used for procedures that take large arguments or return huge results.
svc_fd_create()
This routine creates a service on top of an open and bound file descriptor, and returns the handle to it. Typically, this descriptor is a connected file descriptor for a connection-oriented transport. sendsz and recvsz indicate
sizes for the send and receive buffers. If they are 0, reasonable defaults are chosen. This routine returns NULL if it fails, and an error message is logged.
svc_raw_create()
This routine creates an RPC service handle and returns a pointer to it. The transport is really a buffer within the process's address space, so the corresponding RPC client should live in the same address space; (see clnt_raw_create() in rpc_clnt_create(3NSL)). This routine allows simulation of RPC and acquisition of RPC overheads (such as round trip
times), without any kernel and networking interference. This routine returns NULL if it fails, and an error message is logged.
Note: svc_run() should not be called when the raw interface is being used.
svc_tli_create()
This routine creates an RPC server handle, and returns a pointer to it. fildes is the file descriptor on which the service is listening. If fildes is RPC_ANYFD, it opens a file descriptor
on the transport specified by netconf. If the file descriptor is unbound and bindaddr is non-null fildes is bound to the address specified by bindaddr, otherwise fildes is
bound to a default address chosen by the transport. In the case where the default address is chosen, the number of outstanding connect requests is set to 8 for connection-oriented transports. The user may specify the size of the send and receive buffers with the parameters sendsz and recvsz; values of 0 choose suitable defaults. This routine returns NULL if it fails, and an error message is logged. The server is not registered with the rpcbind(1M) service.
svc_tp_create()
svc_tp_create() creates a server handle for the network specified by netconf, and registers itself with the rpcbind service. dispatch is called when there is a remote procedure call for
the given prognum and versnum; this requires calling svc_run(). svc_tp_create() returns the service handle if it succeeds, otherwise a NULL is returned and an error message
is logged.
svc_vc_create()
This routine creates a connection-oriented RPC service and returns a pointer to it. This routine returns NULL if it fails, and an error message is logged. The users may specify the size of the send and receive buffers with the parameters sendsz and recvsz; values of 0 choose suitable defaults. The file descriptor fildes should be open and bound. The server is not registered with the rpcbind(1M) service.
svc_door_create()
This routine creates an RPC server handle over doors and returns a pointer to it. Doors is a transport mechanism that facilitates fast data transfer between processes on the same machine. for the given program The user may set the size of the send buffer with the parameter sendsz. If sendsz is 0, the corresponding default buffer size is 16 Kbyte. If successful, the svc_door_create() routine returns the service handle. Otherwise it returns NULL and sets a value for rpc_createerr. The server is not registered with rpcbind(1M). The SVCSET_CONNMAXREC and SVCGET_CONNMAXRECsvc_control() requests
can be used to set and change the maximum allowed request size for the doors transport.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes: