+/*
+ * transmit.c
+ * - construct queries
+ * - send queries
+ */
+/*
+ * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+
+#include "internal.h"
+
+adns_status adns__mkquery(adns_state ads, vbuf *vb,
+ const char *owner, int ol, int *id_r,
+ const typeinfo *typei, adns_queryflags flags) {
+ int ll, c, nlabs, id;
+ byte label[255], *rqp;
+ const char *p, *pe;
+
+#define MKQUERY_ADDB(b) *rqp++= (b)
+#define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
+
+ vb->used= 0;
+ if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+strlen(owner)+1+5))
+ return adns_s_nolocalmem;
+ rqp= vb->buf;
+
+ *id_r= id= (ads->nextid++) & 0x0ffff;
+
+ MKQUERY_ADDW(id);
+ MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
+ MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
+ MKQUERY_ADDW(1); /* QDCOUNT=1 */
+ MKQUERY_ADDW(0); /* ANCOUNT=0 */
+ MKQUERY_ADDW(0); /* NSCOUNT=0 */
+ MKQUERY_ADDW(0); /* ARCOUNT=0 */
+ p= owner; pe= owner+ol;
+ nlabs= 0;
+ if (!*p) return adns_s_invaliddomain;
+ do {
+ ll= 0;
+ while (p!=pe && (c= *p++)!='.') {
+ if (c=='\\') {
+ if (!(flags & adns_qf_anyquote)) return adns_s_invaliddomain;
+ if (ctype_digit(p[0])) {
+ if (ctype_digit(p[1]) && ctype_digit(p[2])) {
+ c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
+ if (c >= 256) return adns_s_invaliddomain;
+ } else {
+ return adns_s_invaliddomain;
+ }
+ } else if (!(c= *p++)) {
+ return adns_s_invaliddomain;
+ }
+ }
+ if (!(flags & adns_qf_anyquote)) {
+ if (ctype_digit(c) || c == '-') {
+ if (!ll) return adns_s_invaliddomain;
+ } else if (!ctype_alpha(c)) {
+ return adns_s_invaliddomain;
+ }
+ }
+ if (ll == sizeof(label)) return adns_s_invaliddomain;
+ label[ll++]= c;
+ }
+ if (!ll) return adns_s_invaliddomain;
+ if (nlabs++ > 63) return adns_s_invaliddomain;
+ MKQUERY_ADDB(ll);
+ memcpy(rqp,label,ll); rqp+= ll;
+ } while (p!=pe);
+
+ MKQUERY_ADDB(0);
+ MKQUERY_ADDW(typei->type & adns__rrt_typemask); /* QTYPE */
+ MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
+
+ vb->used= rqp - vb->buf;
+ assert(vb->used <= vb->avail);
+
+ return adns_s_ok;
+}
+
+void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now) {
+ byte length[2];
+ struct iovec iov[2];
+ int wr, r;
+
+ if (ads->tcpstate != server_ok) return;
+
+ length[0]= (qu->query_dglen&0x0ff00U) >>8;
+ length[1]= (qu->query_dglen&0x0ff);
+
+ if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
+
+ timevaladd(&now,TCPMS);
+ qu->timeout= now;
+ qu->state= query_tcpsent;
+ LIST_LINK_TAIL(ads->timew,qu);
+
+ if (ads->tcpsend.used) {
+ wr= 0;
+ } else {
+ iov[0].iov_base= length;
+ iov[0].iov_len= 2;
+ iov[1].iov_base= qu->query_dgram;
+ iov[1].iov_len= qu->query_dglen;
+ wr= writev(ads->tcpsocket,iov,2);
+ if (wr < 0) {
+ if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
+ errno == ENOBUFS || errno == ENOMEM)) {
+ adns__tcp_broken(ads,"write",strerror(errno));
+ return;
+ }
+ wr= 0;
+ }
+ }
+
+ if (wr<2) {
+ r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
+ wr= 0;
+ } else {
+ wr-= 2;
+ }
+ if (wr<qu->query_dglen) {
+ r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
+ }
+}
+
+static void query_usetcp(adns_state ads, adns_query qu, struct timeval now) {
+ timevaladd(&now,TCPMS);
+ qu->timeout= now;
+ qu->state= query_tcpwait;
+ LIST_LINK_TAIL(ads->timew,qu);
+ adns__query_tcp(ads,qu,now);
+ adns__tcp_tryconnect(ads,now);
+}
+
+void adns__query_udp(adns_state ads, adns_query qu, struct timeval now) {
+ struct sockaddr_in servaddr;
+ int serv, r;
+
+ assert(qu->state == query_udp);
+ if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
+ query_usetcp(ads,qu,now);
+ return;
+ }
+
+ if (qu->udpretries >= UDPMAXRETRIES) {
+ adns__query_fail(ads,qu,adns_s_timeout);
+ return;
+ }
+
+ serv= qu->udpnextserver;
+ memset(&servaddr,0,sizeof(servaddr));
+ servaddr.sin_family= AF_INET;
+ servaddr.sin_addr= ads->servers[serv].addr;
+ servaddr.sin_port= htons(DNS_PORT);
+
+ r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,&servaddr,sizeof(servaddr));
+ if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; }
+ if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
+
+ timevaladd(&now,UDPRETRYMS);
+ qu->timeout= now;
+ qu->udpsent |= (1<<serv);
+ qu->udpnextserver= (serv+1)%ads->nservers;
+ qu->udpretries++;
+ LIST_LINK_TAIL(ads->timew,qu);
+}
~ianmdlvl / adns.git / commitdiff