/* $NetBSD: ns_parse.c,v 1.1.1.2 2012/09/09 16:08:05 christos Exp $ */ /* * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") * Copyright (c) 1996,1999 by Internet Software Consortium. * * Permission to use, copy, modify, and 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. */ #ifndef lint static const char rcsid[] = "Id: ns_parse.c,v 1.10 2009/01/23 19:59:16 each Exp "; #endif /* Import. */ #include "port_before.h" #include #include #include #include #include #include #include "port_after.h" /* Forward. */ static void setsection(ns_msg *msg, ns_sect sect); /* Macros. */ #if !defined(SOLARIS2) || defined(__COVERITY__) #define RETERR(err) do { errno = (err); return (-1); } while (0) #else #define RETERR(err) \ do { errno = (err); if (errno == errno) return (-1); } while (0) #endif #define PARSE_FMT_PRESO 0 /* Parse using presentation-format names */ #define PARSE_FMT_WIRE 1 /* Parse using network-format names */ /* Public. */ /* These need to be in the same order as the nres.h:ns_flag enum. */ struct _ns_flagdata _ns_flagdata[16] = { { 0x8000, 15 }, /*%< qr. */ { 0x7800, 11 }, /*%< opcode. */ { 0x0400, 10 }, /*%< aa. */ { 0x0200, 9 }, /*%< tc. */ { 0x0100, 8 }, /*%< rd. */ { 0x0080, 7 }, /*%< ra. */ { 0x0040, 6 }, /*%< z. */ { 0x0020, 5 }, /*%< ad. */ { 0x0010, 4 }, /*%< cd. */ { 0x000f, 0 }, /*%< rcode. */ { 0x0000, 0 }, /*%< expansion (1/6). */ { 0x0000, 0 }, /*%< expansion (2/6). */ { 0x0000, 0 }, /*%< expansion (3/6). */ { 0x0000, 0 }, /*%< expansion (4/6). */ { 0x0000, 0 }, /*%< expansion (5/6). */ { 0x0000, 0 }, /*%< expansion (6/6). */ }; int ns_msg_getflag(ns_msg handle, int flag) { return(((handle)._flags & _ns_flagdata[flag].mask) >> _ns_flagdata[flag].shift); } int ns_skiprr(const u_char *ptr, const u_char *eom, ns_sect section, int count) { const u_char *optr = ptr; for ((void)NULL; count > 0; count--) { int b, rdlength; b = dn_skipname(ptr, eom); if (b < 0) RETERR(EMSGSIZE); ptr += b/*Name*/ + NS_INT16SZ/*Type*/ + NS_INT16SZ/*Class*/; if (section != ns_s_qd) { if (ptr + NS_INT32SZ + NS_INT16SZ > eom) RETERR(EMSGSIZE); ptr += NS_INT32SZ/*TTL*/; NS_GET16(rdlength, ptr); ptr += rdlength/*RData*/; } } if (ptr > eom) RETERR(EMSGSIZE); return (ptr - optr); } int ns_initparse(const u_char *msg, int msglen, ns_msg *handle) { const u_char *eom = msg + msglen; int i; handle->_msg = msg; handle->_eom = eom; if (msg + NS_INT16SZ > eom) RETERR(EMSGSIZE); NS_GET16(handle->_id, msg); if (msg + NS_INT16SZ > eom) RETERR(EMSGSIZE); NS_GET16(handle->_flags, msg); for (i = 0; i < ns_s_max; i++) { if (msg + NS_INT16SZ > eom) RETERR(EMSGSIZE); NS_GET16(handle->_counts[i], msg); } for (i = 0; i < ns_s_max; i++) if (handle->_counts[i] == 0) handle->_sections[i] = NULL; else { int b = ns_skiprr(msg, eom, (ns_sect)i, handle->_counts[i]); if (b < 0) return (-1); handle->_sections[i] = msg; msg += b; } if (msg != eom) RETERR(EMSGSIZE); setsection(handle, ns_s_max); return (0); } int ns_parserr(ns_msg *handle, ns_sect section, int rrnum, ns_rr *rr) { int b; int tmp; /* Make section right. */ tmp = section; if (tmp < 0 || section >= ns_s_max) RETERR(ENODEV); if (section != handle->_sect) setsection(handle, section); /* Make rrnum right. */ if (rrnum == -1) rrnum = handle->_rrnum; if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) RETERR(ENODEV); if (rrnum < handle->_rrnum) setsection(handle, section); if (rrnum > handle->_rrnum) { b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, rrnum - handle->_rrnum); if (b < 0) return (-1); handle->_msg_ptr += b; handle->_rrnum = rrnum; } /* Do the parse. */ b = dn_expand(handle->_msg, handle->_eom, handle->_msg_ptr, rr->name, NS_MAXDNAME); if (b < 0) return (-1); handle->_msg_ptr += b; if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET16(rr->type, handle->_msg_ptr); NS_GET16(rr->rr_class, handle->_msg_ptr); if (section == ns_s_qd) { rr->ttl = 0; rr->rdlength = 0; rr->rdata = NULL; } else { if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET32(rr->ttl, handle->_msg_ptr); NS_GET16(rr->rdlength, handle->_msg_ptr); if (handle->_msg_ptr + rr->rdlength > handle->_eom) RETERR(EMSGSIZE); rr->rdata = handle->_msg_ptr; handle->_msg_ptr += rr->rdlength; } if (++handle->_rrnum > handle->_counts[(int)section]) setsection(handle, (ns_sect)((int)section + 1)); /* All done. */ return (0); } /* * This is identical to the above but uses network-format (uncompressed) names. */ int ns_parserr2(ns_msg *handle, ns_sect section, int rrnum, ns_rr2 *rr) { int b; int tmp; /* Make section right. */ if ((tmp = section) < 0 || section >= ns_s_max) RETERR(ENODEV); if (section != handle->_sect) setsection(handle, section); /* Make rrnum right. */ if (rrnum == -1) rrnum = handle->_rrnum; if (rrnum < 0 || rrnum >= handle->_counts[(int)section]) RETERR(ENODEV); if (rrnum < handle->_rrnum) setsection(handle, section); if (rrnum > handle->_rrnum) { b = ns_skiprr(handle->_msg_ptr, handle->_eom, section, rrnum - handle->_rrnum); if (b < 0) return (-1); handle->_msg_ptr += b; handle->_rrnum = rrnum; } /* Do the parse. */ b = ns_name_unpack2(handle->_msg, handle->_eom, handle->_msg_ptr, rr->nname, NS_MAXNNAME, &rr->nnamel); if (b < 0) return (-1); handle->_msg_ptr += b; if (handle->_msg_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET16(rr->type, handle->_msg_ptr); NS_GET16(rr->rr_class, handle->_msg_ptr); if (section == ns_s_qd) { rr->ttl = 0; rr->rdlength = 0; rr->rdata = NULL; } else { if (handle->_msg_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET32(rr->ttl, handle->_msg_ptr); NS_GET16(rr->rdlength, handle->_msg_ptr); if (handle->_msg_ptr + rr->rdlength > handle->_eom) RETERR(EMSGSIZE); rr->rdata = handle->_msg_ptr; handle->_msg_ptr += rr->rdlength; } if (++handle->_rrnum > handle->_counts[(int)section]) setsection(handle, (ns_sect)((int)section + 1)); /* All done. */ return (0); } /* Private. */ static void setsection(ns_msg *msg, ns_sect sect) { msg->_sect = sect; if (sect == ns_s_max) { msg->_rrnum = -1; msg->_msg_ptr = NULL; } else { msg->_rrnum = 0; msg->_msg_ptr = msg->_sections[(int)sect]; } } /*! \file */