/* * 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE * CONSORTIUM 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. */ #if !defined(_LIBC) && !defined(lint) static const char rcsid[] = "$BINDId: ns_parse.c,v 8.13 1999/10/13 16:39:35 vixie Exp $"; #endif /* Import. */ #include <sys/types.h> #include <netinet/in.h> #include <arpa/nameser.h> #include <errno.h> #include <resolv.h> #include <string.h> /* Forward. */ static void setsection(ns_msg *msg, ns_sect sect); /* Macros. */ #define RETERR(err) do { __set_errno (err); return (-1); } while (0) /* 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_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; memset(handle, 0x5e, sizeof *handle); 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; /* Make section right. */ if (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->_ptr, handle->_eom, section, rrnum - handle->_rrnum); if (b < 0) return (-1); handle->_ptr += b; handle->_rrnum = rrnum; } /* Do the parse. */ b = dn_expand(handle->_msg, handle->_eom, handle->_ptr, rr->name, NS_MAXDNAME); if (b < 0) return (-1); handle->_ptr += b; if (handle->_ptr + NS_INT16SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET16(rr->type, handle->_ptr); NS_GET16(rr->rr_class, handle->_ptr); if (section == ns_s_qd) { rr->ttl = 0; rr->rdlength = 0; rr->rdata = NULL; } else { if (handle->_ptr + NS_INT32SZ + NS_INT16SZ > handle->_eom) RETERR(EMSGSIZE); NS_GET32(rr->ttl, handle->_ptr); NS_GET16(rr->rdlength, handle->_ptr); if (handle->_ptr + rr->rdlength > handle->_eom) RETERR(EMSGSIZE); rr->rdata = handle->_ptr; handle->_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->_ptr = NULL; } else { msg->_rrnum = 0; msg->_ptr = msg->_sections[(int)sect]; } }