8 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
10 * It is part of adns, which is
11 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
12 * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
14 * This program is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2, or (at your option)
19 * This program is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with this program; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
31 #include <sys/types.h>
37 #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
38 #define MKQUERY_ADDB(b) *rqp++= (b)
39 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
40 #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
42 static adns_status mkquery_header(adns_state ads, vbuf *vb, int *id_r, int qdlen) {
46 if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+qdlen+4)) return adns_s_nomemory;
51 *id_r= id= (ads->nextid++) & 0x0ffff;
53 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
54 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
55 MKQUERY_ADDW(1); /* QDCOUNT=1 */
56 MKQUERY_ADDW(0); /* ANCOUNT=0 */
57 MKQUERY_ADDW(0); /* NSCOUNT=0 */
58 MKQUERY_ADDW(0); /* ARCOUNT=0 */
65 static adns_status mkquery_footer(vbuf *vb, adns_rrtype type) {
69 MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
70 MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
72 assert(vb->used <= vb->avail);
77 adns_status adns__mkquery(adns_state ads, vbuf *vb, int *id_r,
78 const char *owner, int ol,
79 const typeinfo *typei, adns_queryflags flags) {
81 byte label[255], *rqp;
85 st= mkquery_header(ads,vb,id_r,ol+2); if (st) return st;
89 p= owner; pe= owner+ol;
93 while (p!=pe && (c= *p++)!='.') {
95 if (!(flags & adns_qf_quoteok_query)) return adns_s_querydomaininvalid;
96 if (ctype_digit(p[0])) {
97 if (ctype_digit(p[1]) && ctype_digit(p[2])) {
98 c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
99 if (c >= 256) return adns_s_querydomaininvalid;
101 return adns_s_querydomaininvalid;
103 } else if (!(c= *p++)) {
104 return adns_s_querydomaininvalid;
107 if (!(flags & adns_qf_quoteok_query)) {
109 if (!ll) return adns_s_querydomaininvalid;
110 } else if (!ctype_alpha(c) && !ctype_digit(c)) {
111 return adns_s_querydomaininvalid;
114 if (ll == sizeof(label)) return adns_s_querydomaininvalid;
117 if (!ll) return adns_s_querydomaininvalid;
118 if (ll > DNS_MAXLABEL) return adns_s_querydomaintoolong;
120 if (nbytes >= DNS_MAXDOMAIN) return adns_s_querydomaintoolong;
122 memcpy(rqp,label,ll); rqp+= ll;
128 st= mkquery_footer(vb,typei->type);
133 adns_status adns__mkquery_frdgram(adns_state ads, vbuf *vb, int *id_r,
134 const byte *qd_dgram, int qd_dglen, int qd_begin,
135 adns_rrtype type, adns_queryflags flags) {
138 int lablen, labstart;
141 st= mkquery_header(ads,vb,id_r,qd_dglen); if (st) return st;
145 adns__findlabel_start(&fls,ads,-1,0,qd_dgram,qd_dglen,qd_dglen,qd_begin,0);
147 st= adns__findlabel_next(&fls,&lablen,&labstart); assert(!st);
150 MKQUERY_ADDB(lablen);
151 memcpy(rqp,qd_dgram+labstart,lablen);
158 st= mkquery_footer(vb,type);
163 void adns__querysend_tcp(adns_query qu, struct timeval now) {
169 if (qu->ads->tcpstate != server_ok) return;
171 assert(qu->state == query_tcpw);
173 length[0]= (qu->query_dglen&0x0ff00U) >>8;
174 length[1]= (qu->query_dglen&0x0ff);
177 if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
181 /* Reset idle timeout. */
182 ads->tcptimeout.tv_sec= ads->tcptimeout.tv_usec= 0;
184 if (ads->tcpsend.used) {
187 iov[0].iov_base= length;
189 iov[1].iov_base= qu->query_dgram;
190 iov[1].iov_len= qu->query_dglen;
191 adns__sigpipe_protect(qu->ads);
192 wr= writev(qu->ads->tcpsocket,iov,2);
193 adns__sigpipe_unprotect(qu->ads);
195 if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
196 errno == ENOBUFS || errno == ENOMEM)) {
197 adns__tcp_broken(ads,"write",strerror(errno));
205 r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
210 if (wr<qu->query_dglen) {
211 r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
215 static void query_usetcp(adns_query qu, struct timeval now) {
216 qu->state= query_tcpw;
218 timevaladd(&qu->timeout,TCPWAITMS);
219 LIST_LINK_TAIL(qu->ads->tcpw,qu);
220 adns__querysend_tcp(qu,now);
221 adns__tcp_tryconnect(qu->ads,now);
224 void adns__query_send(adns_query qu, struct timeval now) {
225 struct sockaddr_in servaddr;
229 assert(qu->state == query_tosend);
230 if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
231 query_usetcp(qu,now);
235 if (qu->retries >= UDPMAXRETRIES) {
236 adns__query_fail(qu,adns_s_timeout);
240 serv= qu->udpnextserver;
241 memset(&servaddr,0,sizeof(servaddr));
244 servaddr.sin_family= AF_INET;
245 servaddr.sin_addr= ads->servers[serv].addr;
246 servaddr.sin_port= htons(DNS_PORT);
248 r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,
249 (const struct sockaddr*)&servaddr,sizeof(servaddr));
250 if (r<0 && errno == EMSGSIZE) { qu->retries= 0; query_usetcp(qu,now); return; }
251 if (r<0 && errno != EAGAIN) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
254 timevaladd(&qu->timeout,UDPRETRYMS);
255 qu->udpsent |= (1<<serv);
256 qu->udpnextserver= (serv+1)%ads->nservers;
258 LIST_LINK_TAIL(ads->udpw,qu);