7 * This file is part of adns, which is Copyright (C) 1997, 1998 Ian Jackson
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software Foundation,
21 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
32 #define MKQUERY_ADDB(b) *rqp++= (b)
33 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
34 #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
36 static adns_status mkquery_header(adns_state ads, vbuf *vb, int *id_r, int qdlen) {
40 if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
42 *id_r= id= (ads->nextid++) & 0x0ffff;
48 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
49 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
50 MKQUERY_ADDW(1); /* QDCOUNT=1 */
51 MKQUERY_ADDW(0); /* ANCOUNT=0 */
52 MKQUERY_ADDW(0); /* NSCOUNT=0 */
53 MKQUERY_ADDW(0); /* ARCOUNT=0 */
60 static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) {
64 MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
65 MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
67 assert(vb->used <= vb->avail);
72 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
73 const char *owner, int ol,
74 const typeinfo *typei, adns_queryflags flags) {
76 byte label[255], *rqp;
80 st= mkquery_header(ads,vb,id_r,strlen(owner)+2); if (st) return st;
84 p= owner; pe= owner+ol;
86 if (!*p) return adns_s_querydomaininvalid;
89 while (p!=pe && (c= *p++)!='.') {
91 if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
92 if (ctype_digit(p[0])) {
93 if (ctype_digit(p[1]) && ctype_digit(p[2])) {
94 c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
95 if (c >= 256) return adns_s_querydomaininvalid;
97 return adns_s_querydomaininvalid;
99 } else if (!(c= *p++)) {
100 return adns_s_querydomaininvalid;
103 if (!(flags & adns_qf_quoteok_query)) {
105 if (!ll) return adns_s_querydomaininvalid;
106 } else if (!ctype_alpha(c) && !ctype_digit(c)) {
107 return adns_s_querydomaininvalid;
110 if (ll == sizeof(label)) return adns_s_querydomaininvalid;
113 if (!ll) return adns_s_querydomaininvalid;
114 if (nlabs++ > 63) return adns_s_querydomaintoolong;
116 memcpy(rqp,label,ll); rqp+= ll;
122 st= mkquery_footer(vb,typei->type);
127 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
128 const byte *qd_dgram, int qd_dglen, int qd_begin,
129 adns_rrtype type, adns_queryflags flags) {
132 int lablen, labstart;
135 st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
139 adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
141 st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
144 MKQUERY_ADDB(lablen);
145 memcpy(rqp,qd_dgram+labstart,lablen);
152 st= mkquery_footer(vb,type);
157 void adns__query_tcp(adns_query qu, struct timeval now) {
163 if (qu->ads->tcpstate != server_ok) return;
165 length[0]= (qu->query_dglen&0x0ff00U) >>8;
166 length[1]= (qu->query_dglen&0x0ff);
169 if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
171 timevaladd(&now,TCPMS);
173 qu->state= query_tcpsent;
175 if (ads->tcpsend.used) {
178 iov[0].iov_base= length;
180 iov[1].iov_base= qu->query_dgram;
181 iov[1].iov_len= qu->query_dglen;
182 wr= writev(qu->ads->tcpsocket,iov,2);
184 if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
185 errno == ENOBUFS || errno == ENOMEM)) {
186 adns__tcp_broken(ads,"write",strerror(errno));
194 r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
199 if (wr<qu->query_dglen) {
200 r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
204 static void query_usetcp(adns_query qu, struct timeval now) {
205 timevaladd(&now,TCPMS);
207 qu->state= query_tcpwait;
208 LIST_LINK_TAIL(qu->ads->timew,qu);
209 adns__query_tcp(qu,now);
210 adns__tcp_tryconnect(qu->ads,now);
213 void adns__query_udp(adns_query qu, struct timeval now) {
214 struct sockaddr_in servaddr;
218 assert(qu->state == query_udp);
219 if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
220 query_usetcp(qu,now);
224 if (qu->udpretries >= UDPMAXRETRIES) {
225 adns__query_fail(qu,adns_s_timeout);
229 serv= qu->udpnextserver;
230 memset(&servaddr,0,sizeof(servaddr));
233 servaddr.sin_family= AF_INET;
234 servaddr.sin_addr= ads->servers[serv].addr;
235 servaddr.sin_port= htons(DNS_PORT);
237 r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,&servaddr,sizeof(servaddr));
238 if (r<0 && errno == EMSGSIZE) { query_usetcp(qu,now); return; }
239 if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
241 timevaladd(&now,UDPRETRYMS);
243 qu->udpsent |= (1<<serv);
244 qu->udpnextserver= (serv+1)%ads->nservers;
246 LIST_LINK_TAIL(ads->timew,qu);