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| Current File : //usr/src/contrib/bind9/lib/lwres/lwres_gabn.c |
/*
* Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 2000, 2001 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: lwres_gabn.c,v 1.33 2007/06/19 23:47:22 tbox Exp $ */
/*! \file lwres_gabn.c
These are low-level routines for creating and parsing lightweight
resolver name-to-address lookup request and response messages.
There are four main functions for the getaddrbyname opcode. One render
function converts a getaddrbyname request structure --
lwres_gabnrequest_t -- 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 --
lwres_gabnresponse_t -- to the canonical format. This is complemented
by a parse function which converts a packet in canonical format to a
getaddrbyname response structure.
These structures are defined in \link lwres.h <lwres/lwres.h>.\endlink They are shown below.
\code
#define LWRES_OPCODE_GETADDRSBYNAME 0x00010001U
typedef struct lwres_addr lwres_addr_t;
typedef LWRES_LIST(lwres_addr_t) lwres_addrlist_t;
typedef struct {
lwres_uint32_t flags;
lwres_uint32_t addrtypes;
lwres_uint16_t namelen;
char *name;
} lwres_gabnrequest_t;
typedef struct {
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t naddrs;
char *realname;
char **aliases;
lwres_uint16_t realnamelen;
lwres_uint16_t *aliaslen;
lwres_addrlist_t addrs;
void *base;
size_t baselen;
} lwres_gabnresponse_t;
\endcode
lwres_gabnrequest_render() uses resolver context ctx to convert
getaddrbyname request structure req to canonical format. The packet
header structure pkt is initialised and transferred to buffer b. The
contents of *req are then appended to the buffer in canonical format.
lwres_gabnresponse_render() performs the same task, except it converts
a getaddrbyname response structure lwres_gabnresponse_t to the
lightweight resolver's canonical format.
lwres_gabnrequest_parse() uses context ctx to convert the contents of
packet pkt to a lwres_gabnrequest_t structure. Buffer b provides space
to be used for storing this structure. When the function succeeds, the
resulting lwres_gabnrequest_t is made available through *structp.
lwres_gabnresponse_parse() offers the same semantics as
lwres_gabnrequest_parse() except it yields a lwres_gabnresponse_t
structure.
lwres_gabnresponse_free() and lwres_gabnrequest_free() release the
memory in resolver context ctx that was allocated to the
lwres_gabnresponse_t or lwres_gabnrequest_t structures referenced via
structp. Any memory associated with ancillary buffers and strings for
those structures is also discarded.
\section lwres_gabn_return Return Values
The getaddrbyname opcode functions lwres_gabnrequest_render(),
lwres_gabnresponse_render() lwres_gabnrequest_parse() and
lwres_gabnresponse_parse() all return #LWRES_R_SUCCESS on success. They
return #LWRES_R_NOMEMORY if memory allocation fails.
#LWRES_R_UNEXPECTEDEND is returned if the available space in the buffer
b is too small to accommodate the packet header or the
lwres_gabnrequest_t and lwres_gabnresponse_t structures.
lwres_gabnrequest_parse() and lwres_gabnresponse_parse() will return
#LWRES_R_UNEXPECTEDEND if the buffer is not empty after decoding the
received packet. These functions will return #LWRES_R_FAILURE if
pktflags in the packet header structure #lwres_lwpacket_t indicate that
the packet is not a response to an earlier query.
\section lwres_gabn_see See Also
\link lwpacket.c lwres_lwpacket \endlink
*/
#include <config.h>
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <lwres/lwbuffer.h>
#include <lwres/lwpacket.h>
#include <lwres/lwres.h>
#include <lwres/result.h>
#include "context_p.h"
#include "assert_p.h"
/*% uses resolver context ctx to convert getaddrbyname request structure req to canonical format. */
lwres_result_t
lwres_gabnrequest_render(lwres_context_t *ctx, lwres_gabnrequest_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b)
{
unsigned char *buf;
size_t buflen;
int ret;
size_t payload_length;
lwres_uint16_t datalen;
REQUIRE(ctx != NULL);
REQUIRE(req != NULL);
REQUIRE(req->name != NULL);
REQUIRE(pkt != NULL);
REQUIRE(b != NULL);
datalen = strlen(req->name);
payload_length = 4 + 4 + 2 + req->namelen + 1;
buflen = LWRES_LWPACKET_LENGTH + payload_length;
buf = CTXMALLOC(buflen);
if (buf == NULL)
return (LWRES_R_NOMEMORY);
lwres_buffer_init(b, buf, buflen);
pkt->length = buflen;
pkt->version = LWRES_LWPACKETVERSION_0;
pkt->pktflags &= ~LWRES_LWPACKETFLAG_RESPONSE;
pkt->opcode = LWRES_OPCODE_GETADDRSBYNAME;
pkt->result = 0;
pkt->authtype = 0;
pkt->authlength = 0;
ret = lwres_lwpacket_renderheader(b, pkt);
if (ret != LWRES_R_SUCCESS) {
lwres_buffer_invalidate(b);
CTXFREE(buf, buflen);
return (ret);
}
INSIST(SPACE_OK(b, payload_length));
/*
* Flags.
*/
lwres_buffer_putuint32(b, req->flags);
/*
* Address types we'll accept.
*/
lwres_buffer_putuint32(b, req->addrtypes);
/*
* Put the length and the data. We know this will fit because we
* just checked for it.
*/
lwres_buffer_putuint16(b, datalen);
lwres_buffer_putmem(b, (unsigned char *)req->name, datalen);
lwres_buffer_putuint8(b, 0); /* trailing NUL */
INSIST(LWRES_BUFFER_AVAILABLECOUNT(b) == 0);
return (LWRES_R_SUCCESS);
}
/*% converts a getaddrbyname response structure lwres_gabnresponse_t to the lightweight resolver's canonical format. */
lwres_result_t
lwres_gabnresponse_render(lwres_context_t *ctx, lwres_gabnresponse_t *req,
lwres_lwpacket_t *pkt, lwres_buffer_t *b)
{
unsigned char *buf;
size_t buflen;
int ret;
size_t payload_length;
lwres_uint16_t datalen;
lwres_addr_t *addr;
int x;
REQUIRE(ctx != NULL);
REQUIRE(req != NULL);
REQUIRE(pkt != NULL);
REQUIRE(b != NULL);
/* naliases, naddrs */
payload_length = 4 + 2 + 2;
/* real name encoding */
payload_length += 2 + req->realnamelen + 1;
/* each alias */
for (x = 0; x < req->naliases; x++)
payload_length += 2 + req->aliaslen[x] + 1;
/* each address */
x = 0;
addr = LWRES_LIST_HEAD(req->addrs);
while (addr != NULL) {
payload_length += 4 + 2;
payload_length += addr->length;
addr = LWRES_LIST_NEXT(addr, link);
x++;
}
INSIST(x == req->naddrs);
buflen = LWRES_LWPACKET_LENGTH + payload_length;
buf = CTXMALLOC(buflen);
if (buf == NULL)
return (LWRES_R_NOMEMORY);
lwres_buffer_init(b, buf, buflen);
pkt->length = buflen;
pkt->version = LWRES_LWPACKETVERSION_0;
pkt->pktflags |= LWRES_LWPACKETFLAG_RESPONSE;
pkt->opcode = LWRES_OPCODE_GETADDRSBYNAME;
pkt->authtype = 0;
pkt->authlength = 0;
ret = lwres_lwpacket_renderheader(b, pkt);
if (ret != LWRES_R_SUCCESS) {
lwres_buffer_invalidate(b);
CTXFREE(buf, buflen);
return (ret);
}
/*
* Check space needed here.
*/
INSIST(SPACE_OK(b, payload_length));
/* Flags. */
lwres_buffer_putuint32(b, req->flags);
/* encode naliases and naddrs */
lwres_buffer_putuint16(b, req->naliases);
lwres_buffer_putuint16(b, req->naddrs);
/* encode the real name */
datalen = req->realnamelen;
lwres_buffer_putuint16(b, datalen);
lwres_buffer_putmem(b, (unsigned char *)req->realname, datalen);
lwres_buffer_putuint8(b, 0);
/* encode the aliases */
for (x = 0; x < req->naliases; x++) {
datalen = req->aliaslen[x];
lwres_buffer_putuint16(b, datalen);
lwres_buffer_putmem(b, (unsigned char *)req->aliases[x],
datalen);
lwres_buffer_putuint8(b, 0);
}
/* encode the addresses */
addr = LWRES_LIST_HEAD(req->addrs);
while (addr != NULL) {
lwres_buffer_putuint32(b, addr->family);
lwres_buffer_putuint16(b, addr->length);
lwres_buffer_putmem(b, addr->address, addr->length);
addr = LWRES_LIST_NEXT(addr, link);
}
INSIST(LWRES_BUFFER_AVAILABLECOUNT(b) == 0);
INSIST(LWRES_BUFFER_USEDCOUNT(b) == pkt->length);
return (LWRES_R_SUCCESS);
}
/*% Uses context ctx to convert the contents of packet pkt to a lwres_gabnrequest_t structure. */
lwres_result_t
lwres_gabnrequest_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt, lwres_gabnrequest_t **structp)
{
int ret;
char *name;
lwres_gabnrequest_t *gabn;
lwres_uint32_t addrtypes;
lwres_uint32_t flags;
lwres_uint16_t namelen;
REQUIRE(ctx != NULL);
REQUIRE(pkt != NULL);
REQUIRE(b != NULL);
REQUIRE(structp != NULL && *structp == NULL);
if ((pkt->pktflags & LWRES_LWPACKETFLAG_RESPONSE) != 0)
return (LWRES_R_FAILURE);
if (!SPACE_REMAINING(b, 4 + 4))
return (LWRES_R_UNEXPECTEDEND);
flags = lwres_buffer_getuint32(b);
addrtypes = lwres_buffer_getuint32(b);
/*
* Pull off the name itself
*/
ret = lwres_string_parse(b, &name, &namelen);
if (ret != LWRES_R_SUCCESS)
return (ret);
if (LWRES_BUFFER_REMAINING(b) != 0)
return (LWRES_R_TRAILINGDATA);
gabn = CTXMALLOC(sizeof(lwres_gabnrequest_t));
if (gabn == NULL)
return (LWRES_R_NOMEMORY);
gabn->flags = flags;
gabn->addrtypes = addrtypes;
gabn->name = name;
gabn->namelen = namelen;
*structp = gabn;
return (LWRES_R_SUCCESS);
}
/*% Offers the same semantics as lwres_gabnrequest_parse() except it yields a lwres_gabnresponse_t structure. */
lwres_result_t
lwres_gabnresponse_parse(lwres_context_t *ctx, lwres_buffer_t *b,
lwres_lwpacket_t *pkt, lwres_gabnresponse_t **structp)
{
lwres_result_t ret;
unsigned int x;
lwres_uint32_t flags;
lwres_uint16_t naliases;
lwres_uint16_t naddrs;
lwres_gabnresponse_t *gabn;
lwres_addrlist_t addrlist;
lwres_addr_t *addr;
REQUIRE(ctx != NULL);
REQUIRE(pkt != NULL);
REQUIRE(b != NULL);
REQUIRE(structp != NULL && *structp == NULL);
gabn = NULL;
if ((pkt->pktflags & LWRES_LWPACKETFLAG_RESPONSE) == 0)
return (LWRES_R_FAILURE);
/*
* Pull off the name itself
*/
if (!SPACE_REMAINING(b, 4 + 2 + 2))
return (LWRES_R_UNEXPECTEDEND);
flags = lwres_buffer_getuint32(b);
naliases = lwres_buffer_getuint16(b);
naddrs = lwres_buffer_getuint16(b);
gabn = CTXMALLOC(sizeof(lwres_gabnresponse_t));
if (gabn == NULL)
return (LWRES_R_NOMEMORY);
gabn->aliases = NULL;
gabn->aliaslen = NULL;
LWRES_LIST_INIT(gabn->addrs);
gabn->base = NULL;
gabn->flags = flags;
gabn->naliases = naliases;
gabn->naddrs = naddrs;
LWRES_LIST_INIT(addrlist);
if (naliases > 0) {
gabn->aliases = CTXMALLOC(sizeof(char *) * naliases);
if (gabn->aliases == NULL) {
ret = LWRES_R_NOMEMORY;
goto out;
}
gabn->aliaslen = CTXMALLOC(sizeof(lwres_uint16_t) * naliases);
if (gabn->aliaslen == NULL) {
ret = LWRES_R_NOMEMORY;
goto out;
}
}
for (x = 0; x < naddrs; x++) {
addr = CTXMALLOC(sizeof(lwres_addr_t));
if (addr == NULL) {
ret = LWRES_R_NOMEMORY;
goto out;
}
LWRES_LINK_INIT(addr, link);
LWRES_LIST_APPEND(addrlist, addr, link);
}
/*
* Now, pull off the real name.
*/
ret = lwres_string_parse(b, &gabn->realname, &gabn->realnamelen);
if (ret != LWRES_R_SUCCESS)
goto out;
/*
* Parse off the aliases.
*/
for (x = 0; x < gabn->naliases; x++) {
ret = lwres_string_parse(b, &gabn->aliases[x],
&gabn->aliaslen[x]);
if (ret != LWRES_R_SUCCESS)
goto out;
}
/*
* Pull off the addresses. We already strung the linked list
* up above.
*/
addr = LWRES_LIST_HEAD(addrlist);
for (x = 0; x < gabn->naddrs; x++) {
INSIST(addr != NULL);
ret = lwres_addr_parse(b, addr);
if (ret != LWRES_R_SUCCESS)
goto out;
addr = LWRES_LIST_NEXT(addr, link);
}
if (LWRES_BUFFER_REMAINING(b) != 0) {
ret = LWRES_R_TRAILINGDATA;
goto out;
}
gabn->addrs = addrlist;
*structp = gabn;
return (LWRES_R_SUCCESS);
out:
if (gabn != NULL) {
if (gabn->aliases != NULL)
CTXFREE(gabn->aliases, sizeof(char *) * naliases);
if (gabn->aliaslen != NULL)
CTXFREE(gabn->aliaslen,
sizeof(lwres_uint16_t) * naliases);
addr = LWRES_LIST_HEAD(addrlist);
while (addr != NULL) {
LWRES_LIST_UNLINK(addrlist, addr, link);
CTXFREE(addr, sizeof(lwres_addr_t));
addr = LWRES_LIST_HEAD(addrlist);
}
CTXFREE(gabn, sizeof(lwres_gabnresponse_t));
}
return (ret);
}
/*% Release the memory in resolver context ctx that was allocated to the lwres_gabnrequest_t. */
void
lwres_gabnrequest_free(lwres_context_t *ctx, lwres_gabnrequest_t **structp)
{
lwres_gabnrequest_t *gabn;
REQUIRE(ctx != NULL);
REQUIRE(structp != NULL && *structp != NULL);
gabn = *structp;
*structp = NULL;
CTXFREE(gabn, sizeof(lwres_gabnrequest_t));
}
/*% Release the memory in resolver context ctx that was allocated to the lwres_gabnresponse_t. */
void
lwres_gabnresponse_free(lwres_context_t *ctx, lwres_gabnresponse_t **structp)
{
lwres_gabnresponse_t *gabn;
lwres_addr_t *addr;
REQUIRE(ctx != NULL);
REQUIRE(structp != NULL && *structp != NULL);
gabn = *structp;
*structp = NULL;
if (gabn->naliases > 0) {
CTXFREE(gabn->aliases, sizeof(char *) * gabn->naliases);
CTXFREE(gabn->aliaslen,
sizeof(lwres_uint16_t) * gabn->naliases);
}
addr = LWRES_LIST_HEAD(gabn->addrs);
while (addr != NULL) {
LWRES_LIST_UNLINK(gabn->addrs, addr, link);
CTXFREE(addr, sizeof(lwres_addr_t));
addr = LWRES_LIST_HEAD(gabn->addrs);
}
if (gabn->base != NULL)
CTXFREE(gabn->base, gabn->baselen);
CTXFREE(gabn, sizeof(lwres_gabnresponse_t));
}