No empty .Rs/.Re

[netbsd-mini2440.git] / external / bsd / bind / dist / lib / lwres / lwres_gabn.c

/*      $NetBSD$        */

/*
 * 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));
}