Provided by: libtirpc-dev_1.3.4+ds-1.3_amd64 
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_unregister — library routines for
remote procedure calls
SYNOPSIS
#include <rpc/rpc.h>
See “DESCRIPTION” for function declarations.
DESCRIPTION
The svc_*() and clnt_*() 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_destroy(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_destroy().
AUTH *
authnone_create()
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 *
authunix_create(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 *
authunix_create_default()
Calls authunix_create() with the appropriate arguments.
int callrpc(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 clnt_perrno() is handy for translating
failure statuses into messages.
Warning: calling remote procedures with this routine uses UDP/IP as a transport; see
clntudp_create() for restrictions. You do not have control of timeouts or authentication using
this routine.
enum clnt_stat
clnt_broadcast(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 callrpc(), except the call message is broadcast to all locally connected broadcast nets.
Each time it receives a response, this routine calls eachresult(), whose form is:
bool_t eachresult(caddr_t out, struct sockaddr_in *addr)
where out is the same as out passed to clnt_broadcast(), except that the remote procedure's
output is decoded there; addr points to the address of the machine that sent the results. If
eachresult() 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
clnt_call(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 clnt_create(). 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 clnt_destroy(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
clnt_destroy(). If the RPC library opened the associated socket, it will close it also.
Otherwise, the socket remains open.
CLIENT *
clnt_create(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 clnt_control().
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
clnt_control(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:
CLSET_TIMEOUT struct timeval set total timeout
CLGET_TIMEOUT struct timeval get total timeout
Note: if you set the timeout using clnt_control(), the timeout argument passed to clnt_call()
will be ignored in all future calls.
CLGET_SERVER_ADDR struct sockaddr_in get server's address
The following operations are valid for UDP only:
CLSET_RETRY_TIMEOUT struct timeval set the retry timeout
CLGET_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 clnt_freeres(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
clnt_geterr(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
clnt_pcreateerror(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 clnt_create(), clntraw_create(), clnttcp_create(), or clntudp_create() call fails.
void
clnt_perrno(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 callrpc().
void clnt_perror(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 clnt_call().
char *
clnt_spcreateerror(char *s)
Like clnt_pcreateerror(), 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 *
clnt_sperrno(enum clnt_stat stat)
Take the same arguments as clnt_perrno(), 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 clnt_sperrno() 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 printf(), or if a message format different from that
supported by clnt_perrno() is to be used.
Note: unlike clnt_sperror() and clnt_spcreateerror(), clnt_sperrno() returns pointer to static
data, but the result will not get overwritten on each call.
char *
clnt_sperror(CLIENT *rpch, char *s)
Like clnt_perror(), 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 *
clntraw_create(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
svcraw_create(). 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 *
clnttcp_create(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 *
clntudp_create(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 clnt_call().
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 *
clntudp_bufcreate(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 clnt_call().
This allows the user to specify the maximum packet size for sending and receiving UDP-based RPC
messages.
CLIENT *
clntunix_create(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
get_myaddress(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 htons(PMAPPORT). Returns zero on success, non-zero
on failure.
struct pmaplist *
pmap_getmaps(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
pmap_getport(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
pmap_rmtcall(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 callrpc() and clnt_call(). This procedure should be used for a “ping”
and nothing else. See also clnt_broadcast().
bool_t pmap_set(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 svc_register().
bool_t pmap_unset(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 registerrpc(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
svcudp_create() 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 clnt_pcreateerror() to print the reason why.
bool_t svc_destroy(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 svc_run(), 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 svc_freeargs(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 svc_getargs(). This routine returns 1 if the results were successfully
freed, and zero otherwise.
bool_t svc_getargs(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 *
svc_getcaller(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 svc_getreqset(fd_set *rdfds)
This routine is only of interest if a service implementor does not call svc_run(), 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 svc_getreq(int rdfds)
Similar to svc_getreqset(), but limited to 32 descriptors. This interface is obsoleted by
svc_getreqset().
bool_t svc_register(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, dispatch(). 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 svc_register() routine returns one if it succeeds, and zero otherwise.
svc_run()
This routine never returns. It waits for RPC requests to arrive, and calls the appropriate
service procedure using svc_getreq() when one arrives. This procedure is usually waiting for a
select(2) system call to return.
bool_t svc_sendreply(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
svc_unregister(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
svcerr_auth(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
svcerr_decode(SVCXPRT *xprt)
Called by a service dispatch routine that cannot successfully decode its arguments. See also
svc_getargs().
void
svcerr_noproc(SVCXPRT *xprt)
Called by a service dispatch routine that does not implement the procedure number that the caller
requests.
void
svcerr_noprog(SVCXPRT *xprt)
Called when the desired program is not registered with the RPC package. Service implementors
usually do not need this routine.
void
svcerr_progvers(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
svcerr_systemerr(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
svcerr_weakauth(SVCXPRT *xprt)
Called by a service dispatch routine that refuses to perform a remote procedure call due to
insufficient authentication arguments. The routine calls svcerr_auth(xprt, AUTH_TOOWEAK).
SVCXPRT *
svcraw_create(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 clntraw_create(). 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 *
svctcp_create(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 *
svcunix_create(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 not 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 *
svcunixfd_create(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 *
svcfd_create(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 *
svcudp_bufcreate(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_accepted_reply(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_authunix_parms(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_callhdr(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_callmsg(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_opaque_auth(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_pmap(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 pmap_*() interface.
bool_t xdr_pmaplist(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 pmap_*() interface.
bool_t xdr_rejected_reply(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_replymsg(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
xprt_register(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
xprt_unregister(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.
Debian February 16, 1988 RPC_SOC(3)