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Diffstat (limited to '')
| -rw-r--r-- | lib/lwres/lwpacket.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/lib/lwres/lwpacket.c b/lib/lwres/lwpacket.c new file mode 100644 index 0000000..473cc44 --- /dev/null +++ b/lib/lwres/lwpacket.c @@ -0,0 +1,124 @@ +/* + * Copyright (C) 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/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + +/* $Id: lwpacket.c,v 1.18 2007/06/19 23:47:22 tbox Exp $ */ + +/*! \file */ + +/** + * These functions rely on a struct lwres_lwpacket which is defined in + * \link lwpacket.h lwres/lwpacket.h.\endlink + * + * The following opcodes are currently defined: + * + * \li #LWRES_OPCODE_NOOP + * Success is always returned and the packet contents are + * echoed. The \link lwres_noop.c lwres_noop_*()\endlink functions should be used for this + * type. + * + * \li #LWRES_OPCODE_GETADDRSBYNAME + * returns all known addresses for a given name. The + * \link lwres_gabn.c lwres_gabn_*()\endlink functions should be used for this type. + * + * \li #LWRES_OPCODE_GETNAMEBYADDR + * return the hostname for the given address. The + * \link lwres_gnba.c lwres_gnba_*() \endlink functions should be used for this type. + * + * lwres_lwpacket_renderheader() transfers the contents of lightweight + * resolver packet structure #lwres_lwpacket_t *pkt in network byte + * order to the lightweight resolver buffer, *b. + * + * lwres_lwpacket_parseheader() performs the converse operation. It + * transfers data in network byte order from buffer *b to resolver + * packet *pkt. The contents of the buffer b should correspond to a + * #lwres_lwpacket_t. + * + * \section lwpacket_return Return Values + * + * Successful calls to lwres_lwpacket_renderheader() and + * lwres_lwpacket_parseheader() return #LWRES_R_SUCCESS. If there is + * insufficient space to copy data between the buffer *b and + * lightweight resolver packet *pkt both functions return + * #LWRES_R_UNEXPECTEDEND. + */ + +#include <config.h> + +#include <assert.h> +#include <inttypes.h> +#include <stdlib.h> +#include <string.h> + +#include <lwres/lwbuffer.h> +#include <lwres/lwpacket.h> +#include <lwres/result.h> + +#include "assert_p.h" + +/*% Length of Packet */ +#define LWPACKET_LENGTH \ + (sizeof(uint16_t) * 4 + sizeof(uint32_t) * 5) + +/*% transfers the contents of lightweight resolver packet structure lwres_lwpacket_t *pkt in network byte order to the lightweight resolver buffer, *b. */ + +lwres_result_t +lwres_lwpacket_renderheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) { + REQUIRE(b != NULL); + REQUIRE(pkt != NULL); + + if (!SPACE_OK(b, LWPACKET_LENGTH)) + return (LWRES_R_UNEXPECTEDEND); + + lwres_buffer_putuint32(b, pkt->length); + lwres_buffer_putuint16(b, pkt->version); + lwres_buffer_putuint16(b, pkt->pktflags); + lwres_buffer_putuint32(b, pkt->serial); + lwres_buffer_putuint32(b, pkt->opcode); + lwres_buffer_putuint32(b, pkt->result); + lwres_buffer_putuint32(b, pkt->recvlength); + lwres_buffer_putuint16(b, pkt->authtype); + lwres_buffer_putuint16(b, pkt->authlength); + + return (LWRES_R_SUCCESS); +} + +/*% transfers data in network byte order from buffer *b to resolver packet *pkt. The contents of the buffer b should correspond to a lwres_lwpacket_t. */ + +lwres_result_t +lwres_lwpacket_parseheader(lwres_buffer_t *b, lwres_lwpacket_t *pkt) { + uint32_t space; + + REQUIRE(b != NULL); + REQUIRE(pkt != NULL); + + space = LWRES_BUFFER_REMAINING(b); + if (space < LWPACKET_LENGTH) + return (LWRES_R_UNEXPECTEDEND); + + pkt->length = lwres_buffer_getuint32(b); + /* + * XXXBEW/MLG Checking that the buffer is long enough probably + * shouldn't be done here, since this function is supposed to just + * parse the header. + */ + if (pkt->length > space) + return (LWRES_R_UNEXPECTEDEND); + pkt->version = lwres_buffer_getuint16(b); + pkt->pktflags = lwres_buffer_getuint16(b); + pkt->serial = lwres_buffer_getuint32(b); + pkt->opcode = lwres_buffer_getuint32(b); + pkt->result = lwres_buffer_getuint32(b); + pkt->recvlength = lwres_buffer_getuint32(b); + pkt->authtype = lwres_buffer_getuint16(b); + pkt->authlength = lwres_buffer_getuint16(b); + + return (LWRES_R_SUCCESS); +} |