rpc(3N) rpc(3N)
NAME
rpc - library routines for remote procedure calls
DESCRIPTION
RPC routines allow C language programs to make procedure calls on
other machines across a network. First, the client calls a procedure
to send a data packet to the server. On receipt of the packet, the
server calls a dispatch routine to perform the requested service, and
then sends back a reply.
The following sections describe data objects use by the RPC package.
Nettype
Some of the high-level RPC interface routines take a nettype string
as one of the parameters [for example, clntcreate, svccreate,
rpcreg, rpccall]. This string defines a class of transports which
can be used for a particular application. The transports are tried
in left to right order in the NETPATH variable or in top to down
order in the /etc/netconfig file.
nettype can be one of the following:
netpath Choose from the transports which have been indicated by
their token names in the NETPATH variable. If NETPATH is
unset or NULL, it defaults to visible. netpath is the
default nettype.
visible Choose the transports which have the visible flag (v) set
in the /etc/netconfig file.
circuitv This is same as visible except that it chooses only the
connection oriented transports from the entries in
/etc/netconfig file.
datagramv
This is same as visible except that it chooses only the
connectionless datagram transports from the entries in
/etc/netconfig file.
circuitn This is same as netpath except that it chooses only the
connection oriented datagram transports
datagramn
This is same as netpath except that it chooses only the
connectionless datagram transports.
udp It refers to Internet UDP.
tcp It refers to Internet TCP.
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raw This is for memory based RPC, mainly for performance
evaluation.
If nettype is NULL, it defaults to netpath.
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Data Structures
Some of the data structures used by the RPC package are shown below.
The AUTH Structure
union desblock {
struct {
uint32 high;
uint32 low;
} key;
char c[8];
};
typedef union desblock desblock;
extern boolt xdrdesblock();
/*
* Authentication info. Opaque to client.
*/
struct opaqueauth {
enumt oaflavor; /* flavor of auth */
caddrt oabase; /* address of more auth stuff */
uint oalength; /* not to exceed MAXAUTHBYTES */
};
/*
* Auth handle, interface to client side authenticators.
*/
typedef struct {
struct opaqueauth ahcred;
struct opaqueauth ahverf;
union desblock ahkey;
struct authops {
void (*ahnextverf)();
int (*ahmarshal)(); /* nextverf & serialize */
int (*ahvalidate)(); /* validate varifier */
int (*ahrefresh)(); /* refresh credentials */
void (*ahdestroy)(); /* destroy this structure */
} *ahops;
caddrt ahprivate;
} AUTH;
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The CLIENT Structure
/*
* Client rpc handle.
* Created by individual implementations
* Client is responsible for initializing auth, see e.g. authnone.c.
*/
typedef struct {
AUTH *clauth; /* authenticator */
struct clntops {
enum clntstat (*clcall)(); /* call remote procedure */
void (*clabort)(); /* abort a call */
void (*clgeterr)(); /* get specific error code */
boolt (*clfreeres)(); /* frees results */
void (*cldestroy)(); /* destroy this structure */
boolt (*clcontrol)(); /* the ioctl() of rpc */
} *clops;
caddrt clprivate; /* private stuff */
char *clnetid; /* network token */
char *cltp; /* device name */
} CLIENT;
The SVCXPRT Structure
enum xprtstat {
XPRTDIED,
XPRTMOREREQS,
XPRTIDLE
};
/*
* Server side transport handle
*/
typedef struct {
int xpfd;
#define xpsock xpfd
#endif
ushort xpport; /* associated port number.
* Obsolete, but still used to
* specify whether rendezvouser
* or normal connection
*/
(continued)
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struct xpops {
boolt (*xprecv)(); /* receive incoming requests */
enum xprtstat (*xpstat)(); /* get transport status */
boolt (*xpgetargs)(); /* get arguments */
boolt (*xpreply)(); /* send reply */
boolt (*xpfreeargs)(); /* free mem allocated for args */
void (*xpdestroy)(); /* destroy this struct */
} *xpops;
int xpaddrlen; /* length of remote addr. Obsolete */
char *xptp; /* transport provider device name */
char *xpnetid; /* network token */
struct netbuf xpltaddr; /* local transport address */
struct netbuf xprtaddr; /* remote transport address */
char xpraddr[16]; /* remote address. Obsolete */
struct opaqueauth xpverf; /* raw response verifier */
caddrt xpp1; /* private: for use by svc ops */
caddrt xpp2; /* private: for use by svc ops */
caddrt xpp3; /* private: for use by svc lib */
} SVCXPRT;
The XDR Structure
/*
* Xdr operations. XDRENCODE causes the type to be encoded into the
* stream. XDRDECODE causes the type to be extracted from the stream.
* XDRFREE can be used to release the space allocated by an XDRDECODE
* request.
*/
enum xdrop {
XDRENCODE=0,
XDRDECODE=1,
XDRFREE=2
};
/*
* This is the number of bytes per unit of external data.
*/
#define BYTESPERXDRUNIT (4)
#define RNDUP(x) ((((x) + BYTESPERXDRUNIT - 1) / BYTESPERXDRUNIT) \
* BYTESPERXDRUNIT)
/*
* A xdrproct exists for each data type which is to be encoded or decoded.
*
* The second argument to the xdrproct is a pointer to an opaque pointer.
* The opaque pointer generally points to a structure of the data type
* to be decoded. If this pointer is 0, then the type routines should
* allocate dynamic storage of the appropriate size and return it.
* boolt (*xdrproct)(XDR *, caddrt *);
*/
typedef boolt (*xdrproct)();
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/*
* The XDR handle.
* Contains operation which is being applied to the stream,
* an operations vector for the paticular implementation (e.g. see xdrmem.c),
* and two private fields for the use of the particular implementation.
*/
typedef struct {
enum xdrop xop; /* operation; fast additional param */
struct xdrops {
boolt (*xgetlong)(); /* get a long from underlying stream */
boolt (*xputlong)(); /* put a long to " */
boolt (*xgetbytes)(); /* get some bytes from " */
boolt (*xputbytes)(); /* put some bytes to " */
uint (*xgetpostn)(); /* returns bytes off from beginning */
boolt (*xsetpostn)(); /* lets you reposition the stream */
long * (*xinline)(); /* buf quick ptr to buffered data */
void (*xdestroy)(); /* free privates of this xdrstream */
} *xops;
caddrt xpublic; /* users' data */
caddrt xprivate; /* pointer to private data */
caddrt xbase; /* private used for position info */
int xhandy; /* extra private word */
} XDR;
Index to Routines
The following table lists RPC routines and the manual reference pages
on which they are described:
RPC Routine Manual Reference Page
______________________________________________
authdestroy rpcclntauth(3N)
authdesgetucred securerpc(3N)
authdesseccreate securerpc(3N)
authnonecreate rpcclntauth(3N)
authsyscreate rpcclntauth(3N)
authsyscreatedefault rpcclntauth(3N)
clntcall rpcclntcalls(3N)
clntcontrol rpcclntcreate(3N)
clntcreate rpcclntcreate(3N)
clntdestroy rpcclntcreate(3N)
clntdgcreate rpcclntcreate(3N)
clntfreeres rpcclntcalls(3N)
clntgeterr rpcclntcalls(3N)
clntpcreateerror rpcclntcreate(3N)
clntperrno rpcclntcalls(3N)
clntperror rpcclntcalls(3N)
clntrawcreate rpcclntcreate(3N)
clntspcreateerror rpcclntcreate(3N)
clntsperrno rpcclntcalls(3N)
clntsperror rpcclntcalls(3N)
clnttlicreate rpcclntcreate(3N)
clnttpcreate rpcclntcreate(3N)
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clntvccreate rpcclntcreate(3N)
getnetname securerpc(3N)
host2netname securerpc(3N)
keydecryptsession securerpc(3N)
keyencryptsession securerpc(3N)
keygendes securerpc(3N)
keysetsecret securerpc(3N)
netname2host securerpc(3N)
netname2user securerpc(3N)
rpcbroadcast rpcclntcalls(3N)
rpccall rpcclntcalls(3N)
rpcreg rpcsvccalls(3N)
svccreate rpcsvccreate(3N)
svcdestroy rpcsvccreate(3N)
svcdgcreate rpcsvccreate(3N)
svcfdcreate rpcsvccreate(3N)
svcfreeargs rpcsvcreg(3N)
svcgetargs rpcsvcreg(3N)
svcgetreqset rpcsvcreg(3N)
svcgetrpccaller rpcsvcreg(3N)
svcrawcreate rpcsvccreate(3N)
svcreg rpcsvccalls(3N)
svcrun rpcsvcreg(3N)
svcsendreply rpcsvcreg(3N)
svctlicreate rpcsvccreate(3N)
svctpcreate rpcsvccreate(3N)
svcunreg rpcsvccalls(3N)
svcvccreate rpcsvccreate(3N)
svcerrauth rpcsvcerr(3N)
svcerrdecode rpcsvcerr(3N)
svcerrnoproc rpcsvcerr(3N)
svcerrnoprog rpcsvcerr(3N)
svcerrprogvers rpcsvcerr(3N)
svcerrsystemerr rpcsvcerr(3N)
svcerrweakauth rpcsvcerr(3N)
user2netname securerpc(3N)
xdracceptedreply rpcxdr(3N)
xdrauthsysparms rpcxdr(3N)
xdrcallhdr rpcxdr(3N)
xdrcallmsg rpcxdr(3N)
xdropaqueauth rpcxdr(3N)
xdrrejectedreply rpcxdr(3N)
xdrreplymsg rpcxdr(3N)
xprtregister rpcsvccalls(3N)
xprtunregister rpcsvccalls(3N)
FILES
/etc/netconfig
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SEE ALSO
environ(5), getnetconfig(3N), getnetpath(3N), rpcclntauth(3N),
rpcclntcalls(3N), rpcclntcreate(3N), rpcsvccalls(3N),
rpcsvccreate(3N), rpcsvcerr(3N), rpcsvcreg(3N), rpcxdr(3N),
rpcbind(3N), securerpc(3N), xdr(3N), netconfig(4).
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