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Diffstat (limited to 'lib/lwres/man/lwres_noop.3')
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diff --git a/lib/lwres/man/lwres_noop.3 b/lib/lwres/man/lwres_noop.3 new file mode 100644 index 0000000..b922057 --- /dev/null +++ b/lib/lwres/man/lwres_noop.3 @@ -0,0 +1,202 @@ +.\" Copyright (C) 2000, 2001, 2004, 2005, 2007, 2014-2016, 2018, 2019 Internet Systems Consortium, Inc. ("ISC") +.\" +.\" This Source Code Form is subject to the terms of the Mozilla Public +.\" License, v. 2.0. If a copy of the MPL was not distributed with this +.\" file, You can obtain one at http://mozilla.org/MPL/2.0/. +.\" +.hy 0 +.ad l +'\" t +.\" Title: lwres_noop +.\" Author: +.\" Generator: DocBook XSL Stylesheets v1.78.1 <http://docbook.sf.net/> +.\" Date: 2007-06-18 +.\" Manual: BIND9 +.\" Source: ISC +.\" Language: English +.\" +.TH "LWRES_NOOP" "3" "2007\-06\-18" "ISC" "BIND9" +.\" ----------------------------------------------------------------- +.\" * Define some portability stuff +.\" ----------------------------------------------------------------- +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.\" http://bugs.debian.org/507673 +.\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html +.\" ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +.ie \n(.g .ds Aq \(aq +.el .ds Aq ' +.\" ----------------------------------------------------------------- +.\" * set default formatting +.\" ----------------------------------------------------------------- +.\" disable hyphenation +.nh +.\" disable justification (adjust text to left margin only) +.ad l +.\" ----------------------------------------------------------------- +.\" * MAIN CONTENT STARTS HERE * +.\" ----------------------------------------------------------------- +.SH "NAME" +lwres_nooprequest_render, lwres_noopresponse_render, lwres_nooprequest_parse, lwres_noopresponse_parse, lwres_noopresponse_free, lwres_nooprequest_free \- lightweight resolver no\-op message handling +.SH "SYNOPSIS" +.sp +.ft B +.nf +#include <lwres/lwres\&.h> +.fi +.ft +.HP \w'lwres_result_t\ lwres_nooprequest_render('u +.BI "lwres_result_t lwres_nooprequest_render(lwres_context_t\ *" "ctx" ", lwres_nooprequest_t\ *" "req" ", lwres_lwpacket_t\ *" "pkt" ", lwres_buffer_t\ *" "b" ");" +.HP \w'lwres_result_t\ lwres_noopresponse_render('u +.BI "lwres_result_t lwres_noopresponse_render(lwres_context_t\ *" "ctx" ", lwres_noopresponse_t\ *" "req" ", lwres_lwpacket_t\ *" "pkt" ", lwres_buffer_t\ *" "b" ");" +.HP \w'lwres_result_t\ lwres_nooprequest_parse('u +.BI "lwres_result_t lwres_nooprequest_parse(lwres_context_t\ *" "ctx" ", lwres_buffer_t\ *" "b" ", lwres_lwpacket_t\ *" "pkt" ", lwres_nooprequest_t\ **" "structp" ");" +.HP \w'lwres_result_t\ lwres_noopresponse_parse('u +.BI "lwres_result_t lwres_noopresponse_parse(lwres_context_t\ *" "ctx" ", lwres_buffer_t\ *" "b" ", lwres_lwpacket_t\ *" "pkt" ", lwres_noopresponse_t\ **" "structp" ");" +.HP \w'void\ lwres_noopresponse_free('u +.BI "void lwres_noopresponse_free(lwres_context_t\ *" "ctx" ", lwres_noopresponse_t\ **" "structp" ");" +.HP \w'void\ lwres_nooprequest_free('u +.BI "void lwres_nooprequest_free(lwres_context_t\ *" "ctx" ", lwres_nooprequest_t\ **" "structp" ");" +.SH "DESCRIPTION" +.PP +These are low\-level routines for creating and parsing lightweight resolver no\-op request and response messages\&. +.PP +The no\-op message is analogous to a +\fBping\fR +packet: a packet is sent to the resolver daemon and is simply echoed back\&. The opcode is intended to allow a client to determine if the server is operational or not\&. +.PP +There are four main functions for the no\-op opcode\&. One render function converts a no\-op request structure \(em +\fBlwres_nooprequest_t\fR +\(em to the lightweight resolver\*(Aqs canonical format\&. It is complemented by a parse function that converts a packet in this canonical format to a no\-op request structure\&. Another render function converts the no\-op response structure \(em +\fBlwres_noopresponse_t\fR +to the canonical format\&. This is complemented by a parse function which converts a packet in canonical format to a no\-op response structure\&. +.PP +These structures are defined in +lwres/lwres\&.h\&. They are shown below\&. +.PP +.if n \{\ +.RS 4 +.\} +.nf +#define LWRES_OPCODE_NOOP 0x00000000U +.fi +.if n \{\ +.RE +.\} +.PP +.if n \{\ +.RS 4 +.\} +.nf +typedef struct { + uint16_t datalength; + unsigned char *data; +} lwres_nooprequest_t; +.fi +.if n \{\ +.RE +.\} +.PP +.if n \{\ +.RS 4 +.\} +.nf +typedef struct { + uint16_t datalength; + unsigned char *data; +} lwres_noopresponse_t; +.fi +.if n \{\ +.RE +.\} +.PP +Although the structures have different types, they are identical\&. This is because the no\-op opcode simply echos whatever data was sent: the response is therefore identical to the request\&. +.PP +\fBlwres_nooprequest_render()\fR +uses resolver context +\fIctx\fR +to convert no\-op request structure +\fIreq\fR +to canonical format\&. The packet header structure +\fIpkt\fR +is initialised and transferred to buffer +\fIb\fR\&. The contents of +\fI*req\fR +are then appended to the buffer in canonical format\&. +\fBlwres_noopresponse_render()\fR +performs the same task, except it converts a no\-op response structure +\fBlwres_noopresponse_t\fR +to the lightweight resolver\*(Aqs canonical format\&. +.PP +\fBlwres_nooprequest_parse()\fR +uses context +\fIctx\fR +to convert the contents of packet +\fIpkt\fR +to a +\fBlwres_nooprequest_t\fR +structure\&. Buffer +\fIb\fR +provides space to be used for storing this structure\&. When the function succeeds, the resulting +\fBlwres_nooprequest_t\fR +is made available through +\fI*structp\fR\&. +\fBlwres_noopresponse_parse()\fR +offers the same semantics as +\fBlwres_nooprequest_parse()\fR +except it yields a +\fBlwres_noopresponse_t\fR +structure\&. +.PP +\fBlwres_noopresponse_free()\fR +and +\fBlwres_nooprequest_free()\fR +release the memory in resolver context +\fIctx\fR +that was allocated to the +\fBlwres_noopresponse_t\fR +or +\fBlwres_nooprequest_t\fR +structures referenced via +\fIstructp\fR\&. +.SH "RETURN VALUES" +.PP +The no\-op opcode functions +\fBlwres_nooprequest_render()\fR, +\fBlwres_noopresponse_render()\fR\fBlwres_nooprequest_parse()\fR +and +\fBlwres_noopresponse_parse()\fR +all return +\fBLWRES_R_SUCCESS\fR +on success\&. They return +\fBLWRES_R_NOMEMORY\fR +if memory allocation fails\&. +\fBLWRES_R_UNEXPECTEDEND\fR +is returned if the available space in the buffer +\fIb\fR +is too small to accommodate the packet header or the +\fBlwres_nooprequest_t\fR +and +\fBlwres_noopresponse_t\fR +structures\&. +\fBlwres_nooprequest_parse()\fR +and +\fBlwres_noopresponse_parse()\fR +will return +\fBLWRES_R_UNEXPECTEDEND\fR +if the buffer is not empty after decoding the received packet\&. These functions will return +\fBLWRES_R_FAILURE\fR +if +\fBpktflags\fR +in the packet header structure +\fBlwres_lwpacket_t\fR +indicate that the packet is not a response to an earlier query\&. +.SH "SEE ALSO" +.PP +\fBlwres_packet\fR(3) +.SH "AUTHOR" +.PP +\fBInternet Systems Consortium, Inc\&.\fR +.SH "COPYRIGHT" +.br +Copyright \(co 2000, 2001, 2004, 2005, 2007, 2014-2016, 2018, 2019 Internet Systems Consortium, Inc. ("ISC") +.br |