/* $OpenBSD: res_mkquery.c,v 1.17 2005/08/06 20:30:04 espie Exp $ */ /* * ++Copyright++ 1985, 1993 * - * Copyright (c) 1985, 1993 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * Portions Copyright (c) 1993 by Digital Equipment Corporation. * * 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, and that * the name of Digital Equipment Corporation not be used in advertising or * publicity pertaining to distribution of the document or software without * specific, written prior permission. * * THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL * WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT * CORPORATION 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. * - * --Copyright-- */ #include #include #include #include #include #include #include #include #include "thread_private.h" /* * Form all types of queries. * Returns the size of the result or -1. */ /* ARGSUSED */ int res_mkquery(int op, const char *dname, /* opcode of query */ int class, /* domain name */ int type, /* class and type of query */ const u_char *data, /* resource record data */ int datalen, /* length of data */ const u_char *newrr_in, /* new rr for modify or append */ u_char *buf, /* buffer to put query */ int buflen) /* size of buffer */ { struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res); HEADER *hp; u_char *cp, *ep; int n; u_char *dnptrs[20], **dpp, **lastdnptr; if (_res_init(0) == -1) { h_errno = NETDB_INTERNAL; return (-1); } #ifdef DEBUG if (_resp->options & RES_DEBUG) printf(";; res_mkquery(%d, %s, %d, %d)\n", op, dname, class, type); #endif /* * Initialize header fields. * * A special random number generator is used to create non predictable * and non repeating ids over a long period. It also avoids reuse * by switching between two distinct number cycles. */ if ((buf == NULL) || (buflen < HFIXEDSZ)) return (-1); bzero(buf, HFIXEDSZ); hp = (HEADER *) buf; _resp->id = res_randomid(); hp->id = htons(_resp->id); hp->opcode = op; hp->rd = (_resp->options & RES_RECURSE) != 0; hp->rcode = NOERROR; cp = buf + HFIXEDSZ; ep = buf + buflen; dpp = dnptrs; *dpp++ = buf; *dpp++ = NULL; lastdnptr = dnptrs + sizeof dnptrs / sizeof dnptrs[0]; /* * perform opcode specific processing */ switch (op) { case QUERY: /*FALLTHROUGH*/ case NS_NOTIFY_OP: if (ep - cp < QFIXEDSZ) return (-1); if ((n = dn_comp(dname, cp, ep - cp - QFIXEDSZ, dnptrs, lastdnptr)) < 0) return (-1); cp += n; __putshort(type, cp); cp += INT16SZ; __putshort(class, cp); cp += INT16SZ; hp->qdcount = htons(1); if (op == QUERY || data == NULL) break; /* * Make an additional record for completion domain. */ if (ep - cp < RRFIXEDSZ) return (-1); n = dn_comp((char *)data, cp, ep - cp - RRFIXEDSZ, dnptrs, lastdnptr); if (n < 0) return (-1); cp += n; __putshort(T_NULL, cp); cp += INT16SZ; __putshort(class, cp); cp += INT16SZ; __putlong(0, cp); cp += INT32SZ; __putshort(0, cp); cp += INT16SZ; hp->arcount = htons(1); break; case IQUERY: /* * Initialize answer section */ if (ep - cp < 1 + RRFIXEDSZ + datalen) return (-1); *cp++ = '\0'; /* no domain name */ __putshort(type, cp); cp += INT16SZ; __putshort(class, cp); cp += INT16SZ; __putlong(0, cp); cp += INT32SZ; __putshort(datalen, cp); cp += INT16SZ; if (datalen) { bcopy(data, cp, datalen); cp += datalen; } hp->ancount = htons(1); break; default: return (-1); } return (cp - buf); } /* attach OPT pseudo-RR, as documented in RFC2671 (EDNS0). */ int res_opt(int n0, u_char *buf, /* buffer to put query */ int buflen, /* size of buffer */ int anslen) /* answer buffer length */ { struct __res_state *_resp = _THREAD_PRIVATE(_res, _res, &_res); HEADER *hp; u_char *cp, *ep; hp = (HEADER *) buf; cp = buf + n0; ep = buf + buflen; if (ep - cp < 1 + RRFIXEDSZ) return -1; *cp++ = 0; /* "." */ __putshort(T_OPT, cp); /* TYPE */ cp += INT16SZ; if (anslen > 0xffff) anslen = 0xffff; /* limit to 16bit value */ __putshort(anslen & 0xffff, cp); /* CLASS = UDP payload size */ cp += INT16SZ; *cp++ = NOERROR; /* extended RCODE */ *cp++ = 0; /* EDNS version */ if (_resp->options & RES_USE_DNSSEC) { #ifdef DEBUG if (_resp->options & RES_DEBUG) printf(";; res_opt()... ENDS0 DNSSEC OK\n"); #endif /* DEBUG */ __putshort(DNS_MESSAGEEXTFLAG_DO, cp); /* EDNS Z field */ cp += INT16SZ; } else { __putshort(0, cp); /* EDNS Z field */ cp += INT16SZ; } __putshort(0, cp); /* RDLEN */ cp += INT16SZ; hp->arcount = htons(ntohs(hp->arcount) + 1); return cp - buf; }