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
);