RPC_SVC_CALLS(3) BSD Library Functions Manual RPC_SVC_CALLS(3)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
LIBRARY
Standard C Library (libc, -lc)
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, void *out);
DESCRIPTION
These routines are part of the RPC library which allows C language pro‐
grams 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 oth‐
ers (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 activ‐
ity is to be resumed, services must be reregis‐
tered 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 asyn‐
chronous 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 success‐
fully 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 descrip‐
tors; 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 num‐
ber 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 descrip‐
tors; 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 deriva‐
tion 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 deriva‐
tion 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 trans‐
port 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.
SEE ALSOpoll(2), select(2), rpc(3), rpc_svc_create(3), rpc_svc_err(3),
rpc_svc_reg(3)BSD May 3, 1993 BSD
