1156952Sume/* 2156952Sume * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") 3156952Sume * Copyright (c) 1996,1999 by Internet Software Consortium. 4156952Sume * 5156952Sume * Permission to use, copy, modify, and distribute this software for any 6156952Sume * purpose with or without fee is hereby granted, provided that the above 7156952Sume * copyright notice and this permission notice appear in all copies. 8156952Sume * 9156952Sume * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES 10156952Sume * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11156952Sume * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR 12156952Sume * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13156952Sume * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14156952Sume * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 15156952Sume * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16156952Sume */ 17156952Sume 18156952Sume#ifndef lint 19269867Sumestatic const char rcsid[] = "$Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp $"; 20156952Sume#endif 21269867Sume#include <sys/cdefs.h> 22269867Sume__FBSDID("$FreeBSD$"); 23156952Sume 24156952Sume/* Import. */ 25156952Sume 26156952Sume#include "port_before.h" 27156952Sume 28156952Sume#include <sys/types.h> 29156952Sume 30156952Sume#include <netinet/in.h> 31156952Sume#include <arpa/nameser.h> 32156952Sume 33156952Sume#include <errno.h> 34156952Sume#include <resolv.h> 35156952Sume#include <string.h> 36156952Sume 37156952Sume#include "port_after.h" 38156952Sume 39156952Sume/* Forward. */ 40156952Sume 41156952Sumestatic void setsection(ns_msg *msg, ns_sect sect); 42156952Sume 43156952Sume/* Macros. */ 44156952Sume 45174223Sume#if !defined(SOLARIS2) || defined(__COVERITY__) 46156952Sume#define RETERR(err) do { errno = (err); return (-1); } while (0) 47156952Sume#else 48156952Sume#define RETERR(err) \ 49156952Sume do { errno = (err); if (errno == errno) return (-1); } while (0) 50156952Sume#endif 51156952Sume 52269867Sume#define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */ 53269867Sume#define PARSE_FMT_WIRE 1 /* Parse using network-format names */ 54269867Sume 55156952Sume/* Public. */ 56156952Sume 57156952Sume/* These need to be in the same order as the nres.h:ns_flag enum. */ 58156952Sumestruct _ns_flagdata _ns_flagdata[16] = { 59170242Sume { 0x8000, 15 }, /*%< qr. */ 60170242Sume { 0x7800, 11 }, /*%< opcode. */ 61170242Sume { 0x0400, 10 }, /*%< aa. */ 62170242Sume { 0x0200, 9 }, /*%< tc. */ 63170242Sume { 0x0100, 8 }, /*%< rd. */ 64170242Sume { 0x0080, 7 }, /*%< ra. */ 65170242Sume { 0x0040, 6 }, /*%< z. */ 66170242Sume { 0x0020, 5 }, /*%< ad. */ 67170242Sume { 0x0010, 4 }, /*%< cd. */ 68170242Sume { 0x000f, 0 }, /*%< rcode. */ 69170242Sume { 0x0000, 0 }, /*%< expansion (1/6). */ 70170242Sume { 0x0000, 0 }, /*%< expansion (2/6). */ 71170242Sume { 0x0000, 0 }, /*%< expansion (3/6). */ 72170242Sume { 0x0000, 0 }, /*%< expansion (4/6). */ 73170242Sume { 0x0000, 0 }, /*%< expansion (5/6). */ 74170242Sume { 0x0000, 0 }, /*%< expansion (6/6). */ 75156952Sume}; 76156952Sume 77156952Sumeint ns_msg_getflag(ns_msg handle, int flag) { 78156952Sume return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); 79156952Sume} 80156952Sume 81156952Sumeint 82156952Sumens_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { 83156952Sume const u_char *optr = ptr; 84156952Sume 85156952Sume for ((void)NULL; count > 0; count--) { 86156952Sume int b, rdlength; 87156952Sume 88156952Sume b = dn_skipname(ptr, eom); 89156952Sume if (b < 0) 90156952Sume RETERR(EMSGSIZE); 91156952Sume ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; 92156952Sume if (section != ns_s_qd) { 93156952Sume if (ptr + NS_INT32SZ + NS_INT16SZ > eom) 94156952Sume RETERR(EMSGSIZE); 95156952Sume ptr += NS_INT32SZ/*TTL*/; 96156952Sume NS_GET16(rdlength, ptr); 97156952Sume ptr += rdlength/*RData*/; 98156952Sume } 99156952Sume } 100156952Sume if (ptr > eom) 101156952Sume RETERR(EMSGSIZE); 102156952Sume return (ptr - optr); 103156952Sume} 104156952Sume 105156952Sumeint 106156952Sumens_initparse(const u_char *msg, int msglen, ns_msg *handle) { 107156952Sume const u_char *eom = msg + msglen; 108156952Sume int i; 109156952Sume 110156952Sume handle->_msg = msg; 111156952Sume handle->_eom = eom; 112156952Sume if (msg + NS_INT16SZ > eom) 113156952Sume RETERR(EMSGSIZE); 114156952Sume NS_GET16(handle->_id, msg); 115156952Sume if (msg + NS_INT16SZ > eom) 116156952Sume RETERR(EMSGSIZE); 117156952Sume NS_GET16(handle->_flags, msg); 118156952Sume for (i = 0; i < ns_s_max; i++) { 119156952Sume if (msg + NS_INT16SZ > eom) 120156952Sume RETERR(EMSGSIZE); 121156952Sume NS_GET16(handle->_counts[i], msg); 122156952Sume } 123156952Sume for (i = 0; i < ns_s_max; i++) 124156952Sume if (handle->_counts[i] == 0) 125156952Sume handle->_sections[i] = NULL; 126156952Sume else { 127156952Sume int b = ns_skiprr(msg, eom, (ns_sect)i, 128156952Sume handle->_counts[i]); 129156952Sume 130156952Sume if (b < 0) 131156952Sume return (-1); 132156952Sume handle->_sections[i] = msg; 133156952Sume msg += b; 134156952Sume } 135156952Sume if (msg != eom) 136156952Sume RETERR(EMSGSIZE); 137156952Sume setsection(handle, ns_s_max); 138156952Sume return (0); 139156952Sume} 140156952Sume 141156952Sumeint 142156952Sumens_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { 143156952Sume int b; 144156952Sume int tmp; 145156952Sume 146156952Sume /* Make section right. */ 147156952Sume tmp = section; 148156952Sume if (tmp < 0 || section >= ns_s_max) 149156952Sume RETERR(ENODEV); 150156952Sume if (section != handle->_sect) 151156952Sume setsection(handle, section); 152156952Sume 153156952Sume /* Make rrnum right. */ 154156952Sume if (rrnum == -1) 155156952Sume rrnum = handle->_rrnum; 156156952Sume if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 157156952Sume RETERR(ENODEV); 158156952Sume if (rrnum < handle->_rrnum) 159156952Sume setsection(handle, section); 160156952Sume if (rrnum > handle->_rrnum) { 161156952Sume b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 162156952Sume rrnum - handle->_rrnum); 163156952Sume 164156952Sume if (b < 0) 165156952Sume return (-1); 166156952Sume handle->_msg_ptr += b; 167156952Sume handle->_rrnum = rrnum; 168156952Sume } 169156952Sume 170156952Sume /* Do the parse. */ 171156952Sume b = dn_expand(handle->_msg, handle->_eom, 172156952Sume handle->_msg_ptr, rr->name, NS_MAXDNAME); 173156952Sume if (b < 0) 174156952Sume return (-1); 175156952Sume handle->_msg_ptr += b; 176156952Sume if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 177156952Sume RETERR(EMSGSIZE); 178156952Sume NS_GET16(rr->type, handle->_msg_ptr); 179156952Sume NS_GET16(rr->rr_class, handle->_msg_ptr); 180156952Sume if (section == ns_s_qd) { 181156952Sume rr->ttl = 0; 182156952Sume rr->rdlength = 0; 183156952Sume rr->rdata = NULL; 184156952Sume } else { 185156952Sume if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 186156952Sume RETERR(EMSGSIZE); 187156952Sume NS_GET32(rr->ttl, handle->_msg_ptr); 188156952Sume NS_GET16(rr->rdlength, handle->_msg_ptr); 189156952Sume if (handle->_msg_ptr + rr->rdlength > handle->_eom) 190156952Sume RETERR(EMSGSIZE); 191156952Sume rr->rdata = handle->_msg_ptr; 192156952Sume handle->_msg_ptr += rr->rdlength; 193156952Sume } 194156952Sume if (++handle->_rrnum > handle->_counts[(int)section]) 195156952Sume setsection(handle, (ns_sect)((int)section + 1)); 196156952Sume 197156952Sume /* All done. */ 198156952Sume return (0); 199156952Sume} 200156952Sume 201269867Sume/* 202269867Sume * This is identical to the above but uses network-format (uncompressed) names. 203269867Sume */ 204269867Sumeint 205269867Sumens_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) { 206269867Sume int b; 207269867Sume int tmp; 208269867Sume 209269867Sume /* Make section right. */ 210269867Sume if ((tmp = section) < 0 || section >= ns_s_max) 211269867Sume RETERR(ENODEV); 212269867Sume if (section != handle->_sect) 213269867Sume setsection(handle, section); 214269867Sume 215269867Sume /* Make rrnum right. */ 216269867Sume if (rrnum == -1) 217269867Sume rrnum = handle->_rrnum; 218269867Sume if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) 219269867Sume RETERR(ENODEV); 220269867Sume if (rrnum < handle->_rrnum) 221269867Sume setsection(handle, section); 222269867Sume if (rrnum > handle->_rrnum) { 223269867Sume b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, 224269867Sume rrnum - handle->_rrnum); 225269867Sume 226269867Sume if (b < 0) 227269867Sume return (-1); 228269867Sume handle->_msg_ptr += b; 229269867Sume handle->_rrnum = rrnum; 230269867Sume } 231269867Sume 232269867Sume /* Do the parse. */ 233269867Sume b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr, 234269867Sume rr->nname, NS_MAXNNAME, &rr->nnamel); 235269867Sume if (b < 0) 236269867Sume return (-1); 237269867Sume handle->_msg_ptr += b; 238269867Sume if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) 239269867Sume RETERR(EMSGSIZE); 240269867Sume NS_GET16(rr->type, handle->_msg_ptr); 241269867Sume NS_GET16(rr->rr_class, handle->_msg_ptr); 242269867Sume if (section == ns_s_qd) { 243269867Sume rr->ttl = 0; 244269867Sume rr->rdlength = 0; 245269867Sume rr->rdata = NULL; 246269867Sume } else { 247269867Sume if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) 248269867Sume RETERR(EMSGSIZE); 249269867Sume NS_GET32(rr->ttl, handle->_msg_ptr); 250269867Sume NS_GET16(rr->rdlength, handle->_msg_ptr); 251269867Sume if (handle->_msg_ptr + rr->rdlength > handle->_eom) 252269867Sume RETERR(EMSGSIZE); 253269867Sume rr->rdata = handle->_msg_ptr; 254269867Sume handle->_msg_ptr += rr->rdlength; 255269867Sume } 256269867Sume if (++handle->_rrnum > handle->_counts[(int)section]) 257269867Sume setsection(handle, (ns_sect)((int)section + 1)); 258269867Sume 259269867Sume /* All done. */ 260269867Sume return (0); 261269867Sume} 262269867Sume 263156952Sume/* Private. */ 264156952Sume 265156952Sumestatic void 266156952Sumesetsection(ns_msg *msg, ns_sect sect) { 267156952Sume msg->_sect = sect; 268156952Sume if (sect == ns_s_max) { 269156952Sume msg->_rrnum = -1; 270156952Sume msg->_msg_ptr = NULL; 271156952Sume } else { 272156952Sume msg->_rrnum = 0; 273156952Sume msg->_msg_ptr = msg->_sections[(int)sect]; 274156952Sume } 275156952Sume} 276170242Sume 277170242Sume/*! \file */ 278