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RPC_SOC(3) Library Functions Manual RPC_SOC(3)

NAME

rpc_soc, auth_destroy, authnone_create, authunix_create, authunix_create_default, callrpc, clnt_broadcast, clnt_call, clnt_control, clnt_create, clnt_destroy, clnt_freeres, clnt_geterr, clnt_pcreateerror, clnt_perrno, clnt_perror, clnt_spcreateerror, clnt_sperrno, clnt_sperror, clntraw_create, clnttcp_create, clntudp_bufcreate, clntudp_create, clntunix_create, get_myaddress, pmap_getmaps, pmap_getport, pmap_rmtcall, pmap_set, pmap_unset, registerrpc, rpc_createerr, svc_destroy, svc_fds, svc_fdset, svc_getargs, svc_getcaller, svc_getreq, svc_getreqset, svc_register, svc_run, svc_sendreply, svc_unregister, svcerr_auth, svcerr_decode, svcerr_noproc, svcerr_noprog, svcerr_progvers, svcerr_systemerr, svcerr_weakauth, svcfd_create, svcunixfd_create, svcraw_create, svcunix_create, xdr_accepted_reply, xdr_authunix_parms, xdr_callhdr, xdr_callmsg, xdr_opaque_auth, xdr_pmap, xdr_pmaplist, xdr_rejected_reply, xdr_replymsg, xprt_register, xprt_unregisterlibrary routines for remote procedure calls

SYNOPSIS

#include <rpc/rpc.h>

See DESCRIPTION for function declarations.

DESCRIPTION

The () and () functions described in this page are the old, TS-RPC interface to the XDR and RPC library, and exist for backward compatibility. The new interface is described in the pages referenced from rpc(3).

These routines allow C programs to make procedure calls on other machines across the network. First, the client calls a procedure to send a data packet to the server. Upon receipt of the packet, the server calls a dispatch routine to perform the requested service, and then sends back a reply. Finally, the procedure call returns to the client.

Routines that are used for Secure RPC (DES authentication) are described in rpc_secure(3). Secure RPC can be used only if DES encryption is available.

void
 
(AUTH *auth)

A macro that destroys the authentication information associated with auth. Destruction usually involves deallocation of private data structures. The use of auth is undefined after calling ().

AUTH *
 
()

Create and return an RPC authentication handle that passes nonusable authentication information with each remote procedure call. This is the default authentication used by RPC.

AUTH *
 
(char *host, int uid, int gid, int len, int *aup_gids)

Create and return an RPC authentication handle that contains UNIX authentication information. The host argument is the name of the machine on which the information was created; uid is the user's user ID; gid is the user's current group ID; len and aup_gids refer to a counted array of groups to which the user belongs. It is easy to impersonate a user.

AUTH *
 
()

Calls () with the appropriate arguments.

int (char *host, u_long prognum, u_long versnum, u_long procnum, xdrproc_t inproc, void *in, xdrproc_t outproc, void *out);

Call the remote procedure associated with prognum, versnum, and procnum on the machine host. The in argument is the address of the procedure's argument(s), and out is the address of where to place the result(s); inproc is used to encode the procedure's arguments, and outproc is used to decode the procedure's results. This routine returns zero if it succeeds, or the value of enum clnt_stat cast to an integer if it fails. The routine () is handy for translating failure statuses into messages.

Warning: calling remote procedures with this routine uses UDP/IP as a transport; see () for restrictions. You do not have control of timeouts or authentication using this routine.

enum clnt_stat
 
(u_long prognum, u_long versnum, u_long procnum, xdrproc_t inproc, char *in, xdrproc_t outproc, char *out, bool_t (*eachresult)(caddr_t, struct sockaddr_in *));

Like (), except the call message is broadcast to all locally connected broadcast nets. Each time it receives a response, this routine calls (), whose form is:

bool_t eachresult(caddr_t out, struct sockaddr_in *addr)

where out is the same as out passed to (), except that the remote procedure's output is decoded there; addr points to the address of the machine that sent the results. If () returns zero, clnt_broadcast() waits for more replies; otherwise it returns with appropriate status.

Warning: broadcast sockets are limited in size to the maximum transfer unit of the data link. For ethernet, this value is 1500 bytes.

enum clnt_stat
 
(CLIENT *clnt, u_long procnum, xdrproc_t inproc, char *in, xdrproc_t outproc, char *out, struct timeval tout);

A macro that calls the remote procedure procnum associated with the client handle, clnt, which is obtained with an RPC client creation routine such as (). The in argument is the address of the procedure's argument(s), and out is the address of where to place the result(s); inproc is used to encode the procedure's arguments, and outproc is used to decode the procedure's results; tout is the time allowed for results to come back.

void (CLIENT *clnt)

A macro that destroys the client's RPC handle. Destruction usually involves deallocation of private data structures, including clnt itself. Use of clnt is undefined after calling (). If the RPC library opened the associated socket, it will close it also. Otherwise, the socket remains open.

CLIENT *
 
(char *host, u_long prog, u_long vers, char *proto)

Generic client creation routine. The host argument identifies the name of the remote host where the server is located. The proto argument indicates which kind of transport protocol to use. The currently supported values for this field are "udp" and "tcp". Default timeouts are set, but can be modified using ().

Warning: Using UDP has its shortcomings. Since UDP-based RPC messages can only hold up to 8 Kbytes of encoded data, this transport cannot be used for procedures that take large arguments or return huge results.

bool_t
 
(CLIENT *cl, u_int req, char *info)

A macro used to change or retrieve various information about a client object. The req argument indicates the type of operation, and info is a pointer to the information. For both UDP and TCP, the supported values of req and their argument types and what they do are:

struct timeval set total timeout
struct timeval get total timeout

Note: if you set the timeout using (), the timeout argument passed to clnt_call() will be ignored in all future calls.

struct sockaddr_in get server's address

The following operations are valid for UDP only:

struct timeval set the retry timeout
struct timeval get the retry timeout

The retry timeout is the time that UDP RPC waits for the server to reply before retransmitting the request.

bool_t (CLIENT *clnt, xdrproc_t outproc, char *out)

A macro that frees any data allocated by the RPC/XDR system when it decoded the results of an RPC call. The out argument is the address of the results, and outproc is the XDR routine describing the results. This routine returns one if the results were successfully freed, and zero otherwise.

void
 
(CLIENT *clnt, struct rpc_err *errp)

A macro that copies the error structure out of the client handle to the structure at address errp.

void
 
(char *s)

prints a message to standard error indicating why a client RPC handle could not be created. The message is prepended with string s and a colon. A newline is appended at the end of the message. Used when a (), clntraw_create(), clnttcp_create(), or clntudp_create() call fails.

void
 
(enum clnt_stat stat)

Print a message to standard error corresponding to the condition indicated by stat. A newline is appended at the end of the message. Used after ().

void (CLIENT *clnt, char *s)

Print a message to standard error indicating why an RPC call failed; clnt is the handle used to do the call. The message is prepended with string s and a colon. A newline is appended at the end of the message. Used after ().

char *
 
(char *s)

Like (), except that it returns a string instead of printing to the standard error.

Bugs: returns pointer to static data that is overwritten on each call.

char *
 
(enum clnt_stat stat)

Take the same arguments as (), but instead of sending a message to the standard error indicating why an RPC call failed, return a pointer to a string which contains the message.

The () function is used instead of clnt_perrno() if the program does not have a standard error (as a program running as a server quite likely does not), or if the programmer does not want the message to be output with (), or if a message format different from that supported by clnt_perrno() is to be used.

Note: unlike () and clnt_spcreateerror(), clnt_sperrno() returns pointer to static data, but the result will not get overwritten on each call.

char *
 
(CLIENT *rpch, char *s)

Like (), except that (like clnt_sperrno()) it returns a string instead of printing to standard error.

Bugs: returns pointer to static data that is overwritten on each call.

CLIENT *
 
(u_long prognum, u_long versnum)

This routine creates a toy RPC client for the remote program prognum, version versnum. The transport used to pass messages to the service is actually a buffer within the process's address space, so the corresponding RPC server should live in the same address space; see (). This allows simulation of RPC and acquisition of RPC overheads, such as round trip times, without any kernel interference. This routine returns NULL if it fails.

CLIENT *
 
(struct sockaddr_in *addr, u_long prognum, u_long versnum, int *sockp, u_int sendsz, u_int recvsz);

This routine creates an RPC client for the remote program prognum, version versnum; the client uses TCP/IP as a transport. The remote program is located at Internet address addr. If addr->sin_port is zero, then it is set to the actual port that the remote program is listening on (the remote rpcbind(8) service is consulted for this information). The sockp argument is a socket; if it is RPC_ANYSOCK, then this routine opens a new one and sets sockp. Since TCP-based RPC uses buffered I/O, the user may specify the size of the send and receive buffers with the sendsz and recvsz arguments; values of zero choose suitable defaults. This routine returns NULL if it fails.

CLIENT *
 
(struct sockaddr_in *addr, u_long prognum, u_long versnum, struct timeval wait, int *sockp);

This routine creates an RPC client for the remote program prognum, version versnum; the client uses UDP/IP as a transport. The remote program is located at Internet address addr. If addr->sin_port is zero, then it is set to actual port that the remote program is listening on (the remote rpcbind(8) service is consulted for this information). The sockp argument is a socket; if it is RPC_ANYSOCK, then this routine opens a new one and sets sockp. The UDP transport resends the call message in intervals of wait time until a response is received or until the call times out. The total time for the call to time out is specified by ().

Warning: since UDP-based RPC messages can only hold up to 8 Kbytes of encoded data, this transport cannot be used for procedures that take large arguments or return huge results.

CLIENT *
 
(struct sockaddr_in *addr, u_long prognum, u_long versnum, struct timeval wait, int *sockp, unsigned int sendsize, unsigned int recosize);

This routine creates an RPC client for the remote program prognum, on versnum; the client uses UDP/IP as a transport. The remote program is located at Internet address addr. If addr->sin_port is zero, then it is set to actual port that the remote program is listening on (the remote rpcbind(8) service is consulted for this information). The sockp argument is a socket; if it is RPC_ANYSOCK, then this routine opens a new one and sets sockp. The UDP transport resends the call message in intervals of wait time until a response is received or until the call times out. The total time for the call to time out is specified by ().

This allows the user to specify the maximum packet size for sending and receiving UDP-based RPC messages.

CLIENT *
 
(struct sockaddr_un *raddr, u_long prognum, u_long versnum, int *sockp, u_int sendsz, u_int recvsz);

This routine creates an RPC client for the local program prognum, version versnum; the client uses UNIX-domain sockets as a transport. The local program is located at the *raddr. The sockp argument is a socket; if it is RPC_ANYSOCK, then this routine opens a new one and sets sockp. Since UNIX-based RPC uses buffered I/O, the user may specify the size of the send and receive buffers with the sendsz and recvsz arguments; values of zero choose suitable defaults. This routine returns NULL if it fails.

int
 
(struct sockaddr_in *addr)

Stuff the machine's IP address into addr, without consulting the library routines that deal with /etc/hosts. The port number is always set to (PMAPPORT). Returns zero on success, non-zero on failure.

struct pmaplist *
 
(struct sockaddr_in *addr)

A user interface to the rpcbind(8) service, which returns a list of the current RPC program-to-port mappings on the host located at IP address addr. This routine can return NULL. The command “rpcinfo -p” uses this routine.

u_short
 
(struct sockaddr_in *addr, u_long prognum, u_long versnum, u_long protocol);

A user interface to the rpcbind(8) service, which returns the port number on which waits a service that supports program number prognum, version versnum, and speaks the transport protocol associated with protocol. The value of protocol is most likely IPPROTO_UDP or IPPROTO_TCP. A return value of zero means that the mapping does not exist or that the RPC system failed to contact the remote rpcbind(8) service. In the latter case, the global variable rpc_createerr contains the RPC status.

enum clnt_stat
 
(struct sockaddr_in *addr, u_long prognum, u_long versnum, u_long procnum, xdrproc_t inproc, char *in, xdrproc_t outproc, char *out, struct timeval tout, u_long *portp);

A user interface to the rpcbind(8) service, which instructs rpcbind(8) on the host at IP address addr to make an RPC call on your behalf to a procedure on that host. The portp argument will be modified to the program's port number if the procedure succeeds. The definitions of other arguments are discussed in () and clnt_call(). This procedure should be used for a “ping” and nothing else. See also clnt_broadcast().

bool_t (u_long prognum, u_long versnum, u_long protocol, u_short port)

A user interface to the rpcbind(8) service, which establishes a mapping between the triple (prognum, versnum, protocol) and port on the machine's rpcbind(8) service. The value of protocol is most likely IPPROTO_UDP or IPPROTO_TCP. This routine returns one if it succeeds, zero otherwise. Automatically done by ().

bool_t (u_long prognum, u_long versnum)

A user interface to the rpcbind(8) service, which destroys all mapping between the triple (prognum, versnum, *) and ports on the machine's rpcbind(8) service. This routine returns one if it succeeds, zero otherwise.

bool_t (u_long prognum, u_long versnum, u_long procnum, char *(*procname)(void), xdrproc_t inproc, xdrproc_t outproc);

Register procedure procname with the RPC service package. If a request arrives for program prognum, version versnum, and procedure procnum, procname is called with a pointer to its argument(s); progname should return a pointer to its static result(s); inproc is used to decode the arguments while outproc is used to encode the results. This routine returns zero if the registration succeeded, -1 otherwise.

Warning: remote procedures registered in this form are accessed using the UDP/IP transport; see () for restrictions.

struct rpc_createerr rpc_createerr;

A global variable whose value is set by any RPC client creation routine that does not succeed. Use the routine () to print the reason why.

bool_t (SVCXPRT * xprt)

A macro that destroys the RPC service transport handle, xprt. Destruction usually involves deallocation of private data structures, including xprt itself. Use of xprt is undefined after calling this routine.

fd_set svc_fdset;

A global variable reflecting the RPC service side's read file descriptor bit mask; it is suitable as a template argument to the select(2) system call. This is only of interest if a service implementor does not call (), but rather does his own asynchronous event processing. This variable is read-only (do not pass its address to select(2)!), yet it may change after calls to svc_getreqset() or any creation routines. As well, note that if the process has descriptor limits which are extended beyond FD_SETSIZE, this variable will only be usable for the first FD_SETSIZE descriptors.

int svc_fds;

Similar to svc_fdset, but limited to 32 descriptors. This interface is obsoleted by svc_fdset.

bool_t (SVCXPRT *xprt, xdrproc_t inproc, char *in)

A macro that frees any data allocated by the RPC/XDR system when it decoded the arguments to a service procedure using (). This routine returns 1 if the results were successfully freed, and zero otherwise.

bool_t (SVCXPRT *xprt, xdrproc_t inproc, char *in)

A macro that decodes the arguments of an RPC request associated with the RPC service transport handle, xprt. The in argument is the address where the arguments will be placed; inproc is the XDR routine used to decode the arguments. This routine returns one if decoding succeeds, and zero otherwise.

struct sockaddr_in *
 
(SVCXPRT *xprt)

The approved way of getting the network address of the caller of a procedure associated with the RPC service transport handle, xprt.

void (fd_set *rdfds)

This routine is only of interest if a service implementor does not call (), but instead implements custom asynchronous event processing. It is called when the select(2) system call has determined that an RPC request has arrived on some RPC socket(s); rdfds is the resultant read file descriptor bit mask. The routine returns when all sockets associated with the value of rdfds have been serviced.

void (int rdfds)

Similar to (), but limited to 32 descriptors. This interface is obsoleted by svc_getreqset().

bool_t (SVCXPRT *xprt, u_long prognum, u_long versnum, void (*dispatch)(struct svc_req *, SVCXPRT *), int protocol);

Associates prognum and versnum with the service dispatch procedure, (). If protocol is zero, the service is not registered with the rpcbind(8) service. If protocol is non-zero, then a mapping of the triple (prognum, versnum, protocol) to xprt->xp_port is established with the local rpcbind(8) service (generally protocol is zero, IPPROTO_UDP or IPPROTO_TCP). The procedure dispatch() has the following form:

bool_t dispatch(struct svc_req *request, SVCXPRT *xprt)

The () routine returns one if it succeeds, and zero otherwise.

()

This routine never returns. It waits for RPC requests to arrive, and calls the appropriate service procedure using () when one arrives. This procedure is usually waiting for a select(2) system call to return.

bool_t (SVCXPRT *xprt, xdrproc_t outproc, char *out)

Called by an RPC service's dispatch routine to send the results of a remote procedure call. The xprt argument is the request's associated transport handle; outproc is the XDR routine which is used to encode the results; and out is the address of the results. This routine returns one if it succeeds, zero otherwise.

void
 
(u_long prognum, u_long versnum)

Remove all mapping of the double (prognum, versnum) to dispatch routines, and of the triple (prognum, versnum, *) to port number.

void
 
(SVCXPRT *xprt, enum auth_stat why)

Called by a service dispatch routine that refuses to perform a remote procedure call due to an authentication error.

void
 
(SVCXPRT *xprt)

Called by a service dispatch routine that cannot successfully decode its arguments. See also ().

void
 
(SVCXPRT *xprt)

Called by a service dispatch routine that does not implement the procedure number that the caller requests.

void
 
(SVCXPRT *xprt)

Called when the desired program is not registered with the RPC package. Service implementors usually do not need this routine.

void
 
(SVCXPRT *xprt, u_long low_vers, u_long high_vers)

Called when the desired version of a program is not registered with the RPC package. Service implementors usually do not need this routine.

void
 
(SVCXPRT *xprt)

Called by a service dispatch routine when it detects a system error not covered by any particular protocol. For example, if a service can no longer allocate storage, it may call this routine.

void
 
(SVCXPRT *xprt)

Called by a service dispatch routine that refuses to perform a remote procedure call due to insufficient authentication arguments. The routine calls (xprt, AUTH_TOOWEAK).

SVCXPRT *
 
(void)

This routine creates a toy RPC service transport, to which it returns a pointer. 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 (). This routine allows simulation of RPC and acquisition of RPC overheads (such as round trip times), without any kernel interference. This routine returns NULL if it fails.

SVCXPRT *
 
(int sock, u_int send_buf_size, u_int recv_buf_size)

This routine creates a TCP/IP-based RPC service transport, to which it returns a pointer. The transport is associated with the socket sock, which may be RPC_ANYSOCK, in which case a new socket is created. If the socket is not bound to a local TCP port, then this routine binds it to an arbitrary port. Upon completion, xprt->xp_fd is the transport's socket descriptor, and xprt->xp_port is the transport's port number. This routine returns NULL if it fails. Since TCP-based RPC uses buffered I/O, users may specify the size of buffers; values of zero choose suitable defaults.

SVCXPRT *
 
(int sock, u_int send_buf_size, u_int recv_buf_size, char *path)

This routine creates a UNIX-based RPC service transport, to which it returns a pointer. The transport is associated with the socket sock, which may be RPC_ANYSOCK, in which case a new socket is created. The *path argument is a variable-length file system pathname of at most 104 characters. This file is removed when the socket is closed. The unlink(2) system call must be used to remove the file. Upon completion, xprt->xp_fd is the transport's socket descriptor. This routine returns NULL if it fails. Since UNIX-based RPC uses buffered I/O, users may specify the size of buffers; values of zero choose suitable defaults.

SVCXPRT *
 
(int fd, u_int sendsize, u_int recvsize)

Create a service on top of any open descriptor. The sendsize and recvsize arguments indicate sizes for the send and receive buffers. If they are zero, a reasonable default is chosen.

SVCXPRT *
 
(int fd, u_int sendsize, u_int recvsize)

Create a service on top of any open descriptor. Typically, this descriptor is a connected socket for a stream protocol such as TCP. The sendsize and recvsize arguments indicate sizes for the send and receive buffers. If they are zero, a reasonable default is chosen.

SVCXPRT *
 
(int sock, u_int sendsize, u_int recvsize)

This routine creates a UDP/IP-based RPC service transport, to which it returns a pointer. The transport is associated with the socket sock, which may be RPC_ANYSOCK, in which case a new socket is created. If the socket is not bound to a local UDP port, then this routine binds it to an arbitrary port. Upon completion, xprt->xp_fd is the transport's socket descriptor, and xprt->xp_port is the transport's port number. This routine returns NULL if it fails.

This allows the user to specify the maximum packet size for sending and receiving UDP-based RPC messages.

bool_t (XDR *xdrs, struct accepted_reply *ar)

Used for encoding RPC reply messages. This routine is useful for users who wish to generate RPC-style messages without using the RPC package.

bool_t (XDR *xdrs, struct authunix_parms *aupp)

Used for describing UNIX credentials. This routine is useful for users who wish to generate these credentials without using the RPC authentication package.

void
 
bool_t (XDR *xdrs, struct rpc_msg *chdr)

Used for describing RPC call header messages. This routine is useful for users who wish to generate RPC-style messages without using the RPC package.

bool_t (XDR *xdrs, struct rpc_msg *cmsg)

Used for describing RPC call messages. This routine is useful for users who wish to generate RPC-style messages without using the RPC package.

bool_t (XDR *xdrs, struct opaque_auth *ap)

Used for describing RPC authentication information messages. This routine is useful for users who wish to generate RPC-style messages without using the RPC package.

struct pmap;
 
bool_t (XDR *xdrs, struct pmap *regs)

Used for describing arguments to various rpcbind(8) procedures, externally. This routine is useful for users who wish to generate these arguments without using the () interface.

bool_t (XDR *xdrs, struct pmaplist **rp)

Used for describing a list of port mappings, externally. This routine is useful for users who wish to generate these arguments without using the () interface.

bool_t (XDR *xdrs, struct rejected_reply *rr)

Used for describing RPC reply messages. This routine is useful for users who wish to generate RPC-style messages without using the RPC package.

bool_t (XDR *xdrs, struct rpc_msg *rmsg)

Used for describing RPC reply messages. This routine is useful for users who wish to generate RPC style messages without using the RPC package.

void
 
(SVCXPRT *xprt)

After RPC service transport handles are created, they should register themselves with the RPC service package. This routine modifies the global variable svc_fds. Service implementors usually do not need this routine.

void
 
(SVCXPRT *xprt)

Before an RPC service transport handle is destroyed, it should unregister itself with the RPC service package. This routine modifies the global variable svc_fds. Service implementors usually do not need this routine.

AVAILABILITY

These functions are part of libtirpc.

SEE ALSO

rpc_secure(3), xdr(3)

Remote Procedure Calls: Protocol Specification.

Remote Procedure Call Programming Guide.

rpcgen Programming Guide.

RPC: Remote Procedure Call Protocol Specification, Sun Microsystems, Inc., USC-ISI, RFC1050.

February 16, 1988 Debian