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Diffstat (limited to 'lib/libc/xdr/xdr.3')
-rw-r--r-- | lib/libc/xdr/xdr.3 | 823 |
1 files changed, 823 insertions, 0 deletions
diff --git a/lib/libc/xdr/xdr.3 b/lib/libc/xdr/xdr.3 new file mode 100644 index 0000000..b656ea8 --- /dev/null +++ b/lib/libc/xdr/xdr.3 @@ -0,0 +1,823 @@ +.\" @(#)xdr.3n 2.2 88/08/03 4.0 RPCSRC; from 1.16 88/03/14 SMI +.TH XDR 3N "16 February 1988" +.SH NAME +xdr \- library routines for external data representation +.SH SYNOPSIS AND DESCRIPTION +.LP +These routines allow C programmers to describe +arbitrary data structures in a machine-independent fashion. +Data for remote procedure calls are transmitted using these +routines. +.LP +.ft B +.nf +.sp .5 +xdr_array(xdrs, arrp, sizep, maxsize, elsize, elproc) +\s-1XDR\s0 *xdrs; +char **arrp; +u_int *sizep, maxsize, elsize; +xdrproc_t elproc; +.fi +.ft R +.IP +A filter primitive that translates between variable-length +arrays +and their corresponding external representations. The +parameter +.I arrp +is the address of the pointer to the array, while +.I sizep +is the address of the element count of the array; +this element count cannot exceed +.IR maxsize . +The parameter +.I elsize +is the +.I sizeof +each of the array's elements, and +.I elproc +is an +.SM XDR +filter that translates between +the array elements' C form, and their external +representation. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +xdr_bool(xdrs, bp) +\s-1XDR\s0 *xdrs; +bool_t *bp; +.fi +.ft R +.IP +A filter primitive that translates between booleans (C +integers) +and their external representations. When encoding data, this +filter produces values of either one or zero. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +xdr_bytes(xdrs, sp, sizep, maxsize) +\s-1XDR\s0 *xdrs; +char **sp; +u_int *sizep, maxsize; +.fi +.ft R +.IP +A filter primitive that translates between counted byte +strings and their external representations. +The parameter +.I sp +is the address of the string pointer. The length of the +string is located at address +.IR sizep ; +strings cannot be longer than +.IR maxsize . +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_char(xdrs, cp) +\s-1XDR\s0 *xdrs; +char *cp; +.fi +.ft R +.IP +A filter primitive that translates between C characters +and their external representations. +This routine returns one if it succeeds, zero otherwise. +Note: encoded characters are not packed, and occupy 4 bytes +each. For arrays of characters, it is worthwhile to +consider +.BR xdr_bytes(\|) , +.B xdr_opaque(\|) +or +.BR xdr_string(\|) . +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +void +xdr_destroy(xdrs) +\s-1XDR\s0 *xdrs; +.fi +.ft R +.IP +A macro that invokes the destroy routine associated with the +.SM XDR +stream, +.IR xdrs . +Destruction usually involves freeing private data structures +associated with the stream. Using +.I xdrs +after invoking +.B xdr_destroy(\|) +is undefined. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_double(xdrs, dp) +\s-1XDR\s0 *xdrs; +double *dp; +.fi +.ft R +.IP +A filter primitive that translates between C +.B double +precision numbers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_enum(xdrs, ep) +\s-1XDR\s0 *xdrs; +enum_t *ep; +.fi +.ft R +.IP +A filter primitive that translates between C +.BR enum s +(actually integers) and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +xdr_float(xdrs, fp) +\s-1XDR\s0 *xdrs; +float *fp; +.fi +.ft R +.IP +A filter primitive that translates between C +.BR float s +and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 9 +.LP +.ft B +.nf +.sp .5 +void +xdr_free(proc, objp) +xdrproc_t proc; +char *objp; +.fi +.ft R +.IP +Generic freeing routine. The first argument is the +.SM XDR +routine for the object being freed. The second argument +is a pointer to the object itself. Note: the pointer passed +to this routine is +.I not +freed, but what it points to +.I is +freed (recursively). +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +u_int +xdr_getpos(xdrs) +\s-1XDR\s0 *xdrs; +.fi +.ft R +.IP +A macro that invokes the get-position routine +associated with the +.SM XDR +stream, +.IR xdrs . +The routine returns an unsigned integer, +which indicates the position of the +.SM XDR +byte stream. +A desirable feature of +.SM XDR +streams is that simple arithmetic works with this number, +although the +.SM XDR +stream instances need not guarantee this. +.br +.if t .ne 4 +.LP +.ft B +.nf +.sp .5 +.br +long * +xdr_inline(xdrs, len) +\s-1XDR\s0 *xdrs; +int len; +.fi +.ft R +.IP +A macro that invokes the in-line routine associated with the +.SM XDR +stream, +.IR xdrs . +The routine returns a pointer +to a contiguous piece of the stream's buffer; +.I len +is the byte length of the desired buffer. +Note: pointer is cast to +.BR "long *" . +.IP +Warning: +.B xdr_inline(\|) +may return +.SM NULL +(0) +if it cannot allocate a contiguous piece of a buffer. +Therefore the behavior may vary among stream instances; +it exists for the sake of efficiency. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_int(xdrs, ip) +\s-1XDR\s0 *xdrs; +int *ip; +.fi +.ft R +.IP +A filter primitive that translates between C integers +and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_long(xdrs, lp) +\s-1XDR\s0 *xdrs; +long *lp; +.fi +.ft R +.IP +A filter primitive that translates between C +.B long +integers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 12 +.LP +.ft B +.nf +.sp .5 +void +xdrmem_create(xdrs, addr, size, op) +\s-1XDR\s0 *xdrs; +char *addr; +u_int size; +enum xdr_op op; +.fi +.ft R +.IP +This routine initializes the +.SM XDR +stream object pointed to by +.IR xdrs . +The stream's data is written to, or read from, +a chunk of memory at location +.I addr +whose length is no more than +.I size +bytes long. The +.I op +determines the direction of the +.SM XDR +stream +(either +.BR \s-1XDR_ENCODE\s0 , +.BR \s-1XDR_DECODE\s0 , +or +.BR \s-1XDR_FREE\s0 ). +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +xdr_opaque(xdrs, cp, cnt) +\s-1XDR\s0 *xdrs; +char *cp; +u_int cnt; +.fi +.ft R +.IP +A filter primitive that translates between fixed size opaque +data +and its external representation. +The parameter +.I cp +is the address of the opaque object, and +.I cnt +is its size in bytes. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +xdr_pointer(xdrs, objpp, objsize, xdrobj) +\s-1XDR\s0 *xdrs; +char **objpp; +u_int objsize; +xdrproc_t xdrobj; +.fi +.ft R +.IP +Like +.B xdr_reference(\|) +execpt that it serializes +.SM NULL +pointers, whereas +.B xdr_reference(\|) +does not. Thus, +.B xdr_pointer(\|) +can represent +recursive data structures, such as binary trees or +linked lists. +.br +.if t .ne 15 +.LP +.ft B +.nf +.sp .5 +void +xdrrec_create(xdrs, sendsize, recvsize, handle, readit, writeit) +\s-1XDR\s0 *xdrs; +u_int sendsize, recvsize; +char *handle; +int (*readit) (\|), (*writeit) (\|); +.fi +.ft R +.IP +This routine initializes the +.SM XDR +stream object pointed to by +.IR xdrs . +The stream's data is written to a buffer of size +.IR sendsize ; +a value of zero indicates the system should use a suitable +default. The stream's data is read from a buffer of size +.IR recvsize ; +it too can be set to a suitable default by passing a zero +value. +When a stream's output buffer is full, +.I writeit +is called. Similarly, when a stream's input buffer is empty, +.I readit +is called. The behavior of these two routines is similar to +the +system calls +.B read +and +.BR write , +except that +.I handle +is passed to the former routines as the first parameter. +Note: the +.SM XDR +stream's +.I op +field must be set by the caller. +.IP +Warning: this +.SM XDR +stream implements an intermediate record stream. +Therefore there are additional bytes in the stream +to provide record boundary information. +.br +.if t .ne 9 +.LP +.ft B +.nf +.sp .5 +xdrrec_endofrecord(xdrs, sendnow) +\s-1XDR\s0 *xdrs; +int sendnow; +.fi +.ft R +.IP +This routine can be invoked only on +streams created by +.BR xdrrec_create(\|) . +The data in the output buffer is marked as a completed +record, +and the output buffer is optionally written out if +.I sendnow +is non-zero. This routine returns one if it succeeds, zero +otherwise. +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +xdrrec_eof(xdrs) +\s-1XDR\s0 *xdrs; +int empty; +.fi +.ft R +.IP +This routine can be invoked only on +streams created by +.BR xdrrec_create(\|) . +After consuming the rest of the current record in the stream, +this routine returns one if the stream has no more input, +zero otherwise. +.br +.if t .ne 3 +.LP +.ft B +.nf +.sp .5 +xdrrec_skiprecord(xdrs) +\s-1XDR\s0 *xdrs; +.fi +.ft R +.IP +This routine can be invoked only on +streams created by +.BR xdrrec_create(\|) . +It tells the +.SM XDR +implementation that the rest of the current record +in the stream's input buffer should be discarded. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 11 +.LP +.ft B +.nf +.sp .5 +xdr_reference(xdrs, pp, size, proc) +\s-1XDR\s0 *xdrs; +char **pp; +u_int size; +xdrproc_t proc; +.fi +.ft R +.IP +A primitive that provides pointer chasing within structures. +The parameter +.I pp +is the address of the pointer; +.I size +is the +.I sizeof +the structure that +.I *pp +points to; and +.I proc +is an +.SM XDR +procedure that filters the structure +between its C form and its external representation. +This routine returns one if it succeeds, zero otherwise. +.IP +Warning: this routine does not understand +.SM NULL +pointers. Use +.B xdr_pointer(\|) +instead. +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +xdr_setpos(xdrs, pos) +\s-1XDR\s0 *xdrs; +u_int pos; +.fi +.ft R +.IP +A macro that invokes the set position routine associated with +the +.SM XDR +stream +.IR xdrs . +The parameter +.I pos +is a position value obtained from +.BR xdr_getpos(\|) . +This routine returns one if the +.SM XDR +stream could be repositioned, +and zero otherwise. +.IP +Warning: it is difficult to reposition some types of +.SM XDR +streams, so this routine may fail with one +type of stream and succeed with another. +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +xdr_short(xdrs, sp) +\s-1XDR\s0 *xdrs; +short *sp; +.fi +.ft R +.IP +A filter primitive that translates between C +.B short +integers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +void +xdrstdio_create(xdrs, file, op) +\s-1XDR\s0 *xdrs; +\s-1FILE\s0 *file; +enum xdr_op op; +.fi +.ft R +.IP +This routine initializes the +.SM XDR +stream object pointed to by +.IR xdrs . +The +.SM XDR +stream data is written to, or read from, the Standard +.B I/O +stream +.IR file . +The parameter +.I op +determines the direction of the +.SM XDR +stream (either +.BR \s-1XDR_ENCODE\s0 , +.BR \s-1XDR_DECODE\s0 , +or +.BR \s-1XDR_FREE\s0 ). +.IP +Warning: the destroy routine associated with such +.SM XDR +streams calls +.B fflush(\|) +on the +.I file +stream, but never +.BR fclose(\|) . +.br +.if t .ne 9 +.LP +.ft B +.nf +.sp .5 +xdr_string(xdrs, sp, maxsize) +\s-1XDR\s0 +*xdrs; +char **sp; +u_int maxsize; +.fi +.ft R +.IP +A filter primitive that translates between C strings and +their +corresponding external representations. +Strings cannot be longer than +.IR maxsize . +Note: +.I sp +is the address of the string's pointer. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 8 +.LP +.ft B +.nf +.sp .5 +xdr_u_char(xdrs, ucp) +\s-1XDR\s0 *xdrs; +unsigned char *ucp; +.fi +.ft R +.IP +A filter primitive that translates between +.B unsigned +C characters and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 9 +.LP +.ft B +.nf +.sp .5 +xdr_u_int(xdrs, up) +\s-1XDR\s0 *xdrs; +unsigned *up; +.fi +.ft R +.IP +A filter primitive that translates between C +.B unsigned +integers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_u_long(xdrs, ulp) +\s-1XDR\s0 *xdrs; +unsigned long *ulp; +.fi +.ft R +.IP +A filter primitive that translates between C +.B "unsigned long" +integers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 7 +.LP +.ft B +.nf +.sp .5 +xdr_u_short(xdrs, usp) +\s-1XDR\s0 *xdrs; +unsigned short *usp; +.fi +.ft R +.IP +A filter primitive that translates between C +.B "unsigned short" +integers and their external representations. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 16 +.LP +.ft B +.nf +.sp .5 +xdr_union(xdrs, dscmp, unp, choices, dfault) +\s-1XDR\s0 *xdrs; +int *dscmp; +char *unp; +struct xdr_discrim *choices; +bool_t (*defaultarm) (\|); /* may equal \s-1NULL\s0 */ +.fi +.ft R +.IP +A filter primitive that translates between a discriminated C +.B union +and its corresponding external representation. It first +translates the discriminant of the union located at +.IR dscmp . +This discriminant is always an +.BR enum_t . +Next the union located at +.I unp +is translated. The parameter +.I choices +is a pointer to an array of +.B xdr_discrim(\|) +structures. Each structure contains an ordered pair of +.RI [ value , proc ]. +If the union's discriminant is equal to the associated +.IR value , +then the +.I proc +is called to translate the union. The end of the +.B xdr_discrim(\|) +structure array is denoted by a routine of value +.SM NULL\s0. +If the discriminant is not found in the +.I choices +array, then the +.I defaultarm +procedure is called (if it is not +.SM NULL\s0). +Returns one if it succeeds, zero otherwise. +.br +.if t .ne 6 +.LP +.ft B +.nf +.sp .5 +xdr_vector(xdrs, arrp, size, elsize, elproc) +\s-1XDR\s0 *xdrs; +char *arrp; +u_int size, elsize; +xdrproc_t elproc; +.fi +.ft R +.IP +A filter primitive that translates between fixed-length +arrays +and their corresponding external representations. The +parameter +.I arrp +is the address of the pointer to the array, while +.I size +is is the element count of the array. The parameter +.I elsize +is the +.I sizeof +each of the array's elements, and +.I elproc +is an +.SM XDR +filter that translates between +the array elements' C form, and their external +representation. +This routine returns one if it succeeds, zero otherwise. +.br +.if t .ne 5 +.LP +.ft B +.nf +.sp .5 +xdr_void(\|) +.fi +.ft R +.IP +This routine always returns one. +It may be passed to +.SM RPC +routines that require a function parameter, +where nothing is to be done. +.br +.if t .ne 10 +.LP +.ft B +.nf +.sp .5 +xdr_wrapstring(xdrs, sp) +\s-1XDR\s0 *xdrs; +char **sp; +.fi +.ft R +.IP +A primitive that calls +.B "xdr_string(xdrs, sp,\s-1MAXUN.UNSIGNED\s0 );" +where +.B +.SM MAXUN.UNSIGNED +is the maximum value of an unsigned integer. +.B xdr_wrapstring(\|) +is handy because the +.SM RPC +package passes a maximum of two +.SM XDR +routines as parameters, and +.BR xdr_string(\|) , +one of the most frequently used primitives, requires three. +Returns one if it succeeds, zero otherwise. +.SH SEE ALSO +.BR rpc (3N) +.LP +The following manuals: +.RS +.ft I +eXternal Data Representation Standard: Protocol Specification +.br +eXternal Data Representation: Sun Technical Notes +.ft R +.br +.IR "\s-1XDR\s0: External Data Representation Standard" , +.SM RFC1014, Sun Microsystems, Inc., +.SM USC-ISI\s0. |