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RPC_SOC(3) FreeBSD 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_unregister - library routines for
remote procedure calls
LIBRARY
Standard C Library (libc, -lc)
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.
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
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.
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
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)
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
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)
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)
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
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_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.
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.
FreeBSD 14.0-RELEASE-p11 February 16, 1988 FreeBSD 14.0-RELEASE-p11