From f50ae72ec3417cae55dd4e085991c01af9fdc5f1 Mon Sep 17 00:00:00 2001 From: Martin Nagy Date: Wed, 11 Feb 2009 20:37:59 +0100 Subject: Initial commit --- lib/lwres/lwres_gabn.c | 505 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 505 insertions(+) create mode 100644 lib/lwres/lwres_gabn.c (limited to 'lib/lwres/lwres_gabn.c') diff --git a/lib/lwres/lwres_gabn.c b/lib/lwres/lwres_gabn.c new file mode 100644 index 0000000..3363e66 --- /dev/null +++ b/lib/lwres/lwres_gabn.c @@ -0,0 +1,505 @@ +/* + * 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 .\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 + +#include +#include +#include + +#include +#include +#include +#include + +#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)); +} -- cgit