NAME¶
svc_dg_enablecache
,
svc_exit
,
svc_fdset
,
svc_freeargs
,
svc_getargs
,
svc_getreq_common
,
svc_getreq_poll
,
svc_getreqset
,
svc_getrpccaller
,
svc_pollset
,
svc_run
,
svc_sendreply
—
library routines for RPC servers
SYNOPSIS¶
#include
<rpc/rpc.h>
int
svc_dg_enablecache
(
SVCXPRT
*xprt,
const
unsigned cache_size);
void
svc_exit
(
void);
bool_t
svc_freeargs
(
const
SVCXPRT *xprt,
const xdrproc_t
inproc,
caddr_t
in);
bool_t
svc_getargs
(
const
SVCXPRT *xprt,
const xdrproc_t
inproc,
caddr_t
in);
void
svc_getreq_common
(
const
int fd);
void
svc_getreq_poll
(
struct
pollfd *pfdp,
const int
pollretval);
void
svc_getreqset
(
fd_set
* rdfds);
struct netbuf *
svc_getrpccaller
(
const
SVCXPRT *xprt);
struct cmsgcred *
__svc_getcallercreds
(
const
SVCXPRT *xprt);
struct pollfd svc_pollset[FD_SETSIZE];
void
svc_run
(
void);
bool_t
svc_sendreply
(
SVCXPRT
*xprt,
xdrproc_t
outproc,
char
*out);
DESCRIPTION¶
These routines are part of the RPC library which allows C language programs to
make procedure calls on other machines across the network.
These routines are associated with the server side of the RPC mechanism. Some of
them are called by the server side dispatch function, while others (such as
svc_run
()) are called when the server is
initiated.
Routines¶
See
rpc(3) for the definition of the
SVCXPRT data structure.
svc_dg_enablecache
()
- This function allocates a duplicate request cache for the service endpoint
xprt, large enough to hold
cache_size entries. Once enabled, there
is no way to disable caching. This routine returns 0 if space necessary
for a cache of the given size was successfully allocated, and 1
otherwise.
svc_exit
()
- This function, when called by any of the RPC server procedure or
otherwise, causes
svc_run
() to return.
As currently implemented, svc_exit
()
zeroes the svc_fdset global variable. If
RPC server activity is to be resumed, services must be reregistered with
the RPC library either through one of the
rpc_svc_create(3) functions, or using
xprt_register
(). The
svc_exit
() function has global scope
and ends all RPC server activity.
- fd_set
svc_fdset
- A global variable reflecting the RPC server's read file descriptor bit
mask; it is suitable as an argument to the
select(2) system call. This is only of
interest if service implementors do not call
svc_run
(), but rather do their 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.
svc_freeargs
()
- A function 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
TRUE
if the results were successfully
freed, and FALSE
otherwise.
svc_getargs
()
- A function 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
TRUE
if decoding succeeds, and
FALSE
otherwise.
svc_getreq_common
()
- This routine is called to handle a request on the given file
descriptor.
svc_getreq_poll
()
- 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
poll(2) has determined that an RPC request
has arrived on some RPC file descriptors;
pollretval is the return value from
poll(2) and
pfdp is the array of
pollfd structures on which the
poll(2) was done. It is assumed to be an
array large enough to contain the maximal number of descriptors
allowed.
svc_getreqset
()
- 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
poll(2) has determined that an RPC request
has arrived on some RPC file descriptors;
rdfds is the resultant read file
descriptor bit mask. The routine returns when all file descriptors
associated with the value of rdfds have
been serviced.
svc_getrpccaller
()
- The approved way of getting the network address of the caller of a
procedure associated with the RPC service transport handle
xprt.
__svc_getcallercreds
()
- Warning: this macro is specific to
FreeBSD and thus not portable. This macro returns
a pointer to a cmsgcred structure,
defined in
<sys/socket.h>
,
identifying the calling client. This only works if the client is calling
the server over an AF_LOCAL
socket.
- struct pollfd
svc_pollset[FD_SETSIZE];
- svc_pollset is an array of
pollfd structures derived from
svc_fdset[]. It is suitable as an
argument to the poll(2) system call. The
derivation of svc_pollset from
svc_fdset is made in the current
implementation in
svc_run
(). Service
implementors who do not call svc_run
()
and who wish to use this array must perform this derivation
themselves.
svc_run
()
- This routine never returns. It waits for RPC requests to arrive, and calls
the appropriate service procedure using
svc_getreq_poll
() when one arrives.
This procedure is usually waiting for the
poll(2) system call to return.
svc_sendreply
()
- 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
TRUE
if it succeeds,
FALSE
otherwise.
AVAILABILITY¶
These functions are part of libtirpc.
SEE ALSO¶
poll(2),
select(2),
rpc(3),
rpc_svc_create(3),
rpc_svc_err(3),
rpc_svc_reg(3)