contrib/bind-9.3/lib/lwres/man/lwres_gabn.3

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  24 .TH "LWRES_GABN" "3" "Jun 30, 2000" "BIND9" "BIND9"
  25 .\" disable hyphenation
  26 .nh
  27 .\" disable justification (adjust text to left margin only)
  28 .ad l
  29 .SH "NAME"
  30 lwres_gabnrequest_render, lwres_gabnresponse_render, lwres_gabnrequest_parse, lwres_gabnresponse_parse, lwres_gabnresponse_free, lwres_gabnrequest_free \- lightweight resolver getaddrbyname message handling
  31 .SH "SYNOPSIS"
  32 .nf
  33 #include <lwres/lwres.h>
  34 .fi
  35 .HP 40
  36 \fBlwres_result_t\ \fBlwres_gabnrequest_render\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_gabnrequest_t\ *req\fR\fB, \fR\fBlwres_lwpacket_t\ *pkt\fR\fB, \fR\fBlwres_buffer_t\ *b\fR\fB);\fR
  37 .HP 41
  38 \fBlwres_result_t\ \fBlwres_gabnresponse_render\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_gabnresponse_t\ *req\fR\fB, \fR\fBlwres_lwpacket_t\ *pkt\fR\fB, \fR\fBlwres_buffer_t\ *b\fR\fB);\fR
  39 .HP 39
  40 \fBlwres_result_t\ \fBlwres_gabnrequest_parse\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_buffer_t\ *b\fR\fB, \fR\fBlwres_lwpacket_t\ *pkt\fR\fB, \fR\fBlwres_gabnrequest_t\ **structp\fR\fB);\fR
  41 .HP 40
  42 \fBlwres_result_t\ \fBlwres_gabnresponse_parse\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_buffer_t\ *b\fR\fB, \fR\fBlwres_lwpacket_t\ *pkt\fR\fB, \fR\fBlwres_gabnresponse_t\ **structp\fR\fB);\fR
  43 .HP 29
  44 \fBvoid\ \fBlwres_gabnresponse_free\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_gabnresponse_t\ **structp\fR\fB);\fR
  45 .HP 28
  46 \fBvoid\ \fBlwres_gabnrequest_free\fR\fR\fB(\fR\fBlwres_context_t\ *ctx\fR\fB, \fR\fBlwres_gabnrequest_t\ **structp\fR\fB);\fR
  47 .SH "DESCRIPTION"
  48 .PP
  49 These are low\-level routines for creating and parsing lightweight resolver name\-to\-address lookup request and response messages.
  50 .PP
  51 There are four main functions for the getaddrbyname opcode. One render function converts a getaddrbyname request structure \(em
  52 \fBlwres_gabnrequest_t\fR
  53 \(em to the lighweight resolver's canonical format. It is complemented by a parse function that converts a packet in this canonical format to a getaddrbyname request structure. Another render function converts the getaddrbyname response structure \(em
  54 \fBlwres_gabnresponse_t\fR
  55 \(em to the canonical format. This is complemented by a parse function which converts a packet in canonical format to a getaddrbyname response structure.
  56 .PP
  57 These structures are defined in
  58 \fI<lwres/lwres.h>\fR. They are shown below.
  59 .sp
  60 .nf
  61 #define LWRES_OPCODE_GETADDRSBYNAME     0x00010001U
  62 typedef struct lwres_addr lwres_addr_t;
  63 typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
  64 typedef struct {
  65         lwres_uint32_t  flags;
  66         lwres_uint32_t  addrtypes;
  67         lwres_uint16_t  namelen;
  68         char           *name;
  69 } lwres_gabnrequest_t;
  70 typedef struct {
  71         lwres_uint32_t          flags;
  72         lwres_uint16_t          naliases;
  73         lwres_uint16_t          naddrs;
  74         char                   *realname;
  75         char                  **aliases;
  76         lwres_uint16_t          realnamelen;
  77         lwres_uint16_t         *aliaslen;
  78         lwres_addrlist_t        addrs;
  79         void                   *base;
  80         size_t                  baselen;
  81 } lwres_gabnresponse_t;
  82 .fi
  83 .sp
  84 .PP
  85 \fBlwres_gabnrequest_render()\fR
  86 uses resolver context
  87 \fIctx\fR
  88 to convert getaddrbyname request structure
  89 \fIreq\fR
  90 to canonical format. The packet header structure
  91 \fIpkt\fR
  92 is initialised and transferred to buffer
  93 \fIb\fR. The contents of
  94 \fI*req\fR
  95 are then appended to the buffer in canonical format.
  96 \fBlwres_gabnresponse_render()\fR
  97 performs the same task, except it converts a getaddrbyname response structure
  98 \fBlwres_gabnresponse_t\fR
  99 to the lightweight resolver's canonical format.
 100 .PP
 101 \fBlwres_gabnrequest_parse()\fR
 102 uses context
 103 \fIctx\fR
 104 to convert the contents of packet
 105 \fIpkt\fR
 106 to a
 107 \fBlwres_gabnrequest_t\fR
 108 structure. Buffer
 109 \fIb\fR
 110 provides space to be used for storing this structure. When the function succeeds, the resulting
 111 \fBlwres_gabnrequest_t\fR
 112 is made available through
 113 \fI*structp\fR.
 114 \fBlwres_gabnresponse_parse()\fR
 115 offers the same semantics as
 116 \fBlwres_gabnrequest_parse()\fR
 117 except it yields a
 118 \fBlwres_gabnresponse_t\fR
 119 structure.
 120 .PP
 121 \fBlwres_gabnresponse_free()\fR
 122 and
 123 \fBlwres_gabnrequest_free()\fR
 124 release the memory in resolver context
 125 \fIctx\fR
 126 that was allocated to the
 127 \fBlwres_gabnresponse_t\fR
 128 or
 129 \fBlwres_gabnrequest_t\fR
 130 structures referenced via
 131 \fIstructp\fR. Any memory associated with ancillary buffers and strings for those structures is also discarded.
 132 .SH "RETURN VALUES"
 133 .PP
 134 The getaddrbyname opcode functions
 135 \fBlwres_gabnrequest_render()\fR,
 136 \fBlwres_gabnresponse_render()\fR\fBlwres_gabnrequest_parse()\fR
 137 and
 138 \fBlwres_gabnresponse_parse()\fR
 139 all return
 140 \fBLWRES_R_SUCCESS\fR
 141 on success. They return
 142 \fBLWRES_R_NOMEMORY\fR
 143 if memory allocation fails.
 144 \fBLWRES_R_UNEXPECTEDEND\fR
 145 is returned if the available space in the buffer
 146 \fIb\fR
 147 is too small to accommodate the packet header or the
 148 \fBlwres_gabnrequest_t\fR
 149 and
 150 \fBlwres_gabnresponse_t\fR
 151 structures.
 152 \fBlwres_gabnrequest_parse()\fR
 153 and
 154 \fBlwres_gabnresponse_parse()\fR
 155 will return
 156 \fBLWRES_R_UNEXPECTEDEND\fR
 157 if the buffer is not empty after decoding the received packet. These functions will return
 158 \fBLWRES_R_FAILURE\fR
 159 if
 160 pktflags
 161 in the packet header structure
 162 \fBlwres_lwpacket_t\fR
 163 indicate that the packet is not a response to an earlier query.
 164 .SH "SEE ALSO"
 165 .PP
 166 \fBlwres_packet\fR(3 )