8 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
10 * It is part of adns, which is
11 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
12 * Copyright (C) 1999 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>
36 #define MKQUERY_START(vb) (rqp= (vb)->buf+(vb)->used)
37 #define MKQUERY_ADDB(b) *rqp++= (b)
38 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
39 #define MKQUERY_STOP(vb) ((vb)->used= rqp-(vb)->buf)
41 static adns_status
mkquery_header(adns_state ads
, vbuf
*vb
, int *id_r
, int qdlen
) {
45 if (!adns__vbuf_ensure(vb
,DNS_HDRSIZE
+qdlen
+4)) return adns_s_nomemory
;
50 *id_r
= id
= (ads
->nextid
++) & 0x0ffff;
52 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
53 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
54 MKQUERY_ADDW(1); /* QDCOUNT=1 */
55 MKQUERY_ADDW(0); /* ANCOUNT=0 */
56 MKQUERY_ADDW(0); /* NSCOUNT=0 */
57 MKQUERY_ADDW(0); /* ARCOUNT=0 */
64 static adns_status
mkquery_footer(vbuf
*vb
, adns_rrtype type
) {
68 MKQUERY_ADDW(type
& adns__rrt_typemask
); /* QTYPE */
69 MKQUERY_ADDW(DNS_CLASS_IN
); /* QCLASS=IN */
71 assert(vb
->used
<= vb
->avail
);
76 adns_status
adns__mkquery(adns_state ads
, vbuf
*vb
, int *id_r
,
77 const char *owner
, int ol
,
78 const typeinfo
*typei
, adns_queryflags flags
) {
80 byte label
[255], *rqp
;
84 st
= mkquery_header(ads
,vb
,id_r
,strlen(owner
)+2); if (st
) return st
;
88 p
= owner
; pe
= owner
+ol
;
92 while (p
!=pe
&& (c
= *p
++)!='.') {
94 if (!(flags
& adns_qf_quoteok_query
)) return adns_s_querydomaininvalid
;
95 if (ctype_digit(p
[0])) {
96 if (ctype_digit(p
[1]) && ctype_digit(p
[2])) {
97 c
= (*p
++ - '0')*100 + (*p
++ - '0')*10 + (*p
++ - '0');
98 if (c
>= 256) return adns_s_querydomaininvalid
;
100 return adns_s_querydomaininvalid
;
102 } else if (!(c
= *p
++)) {
103 return adns_s_querydomaininvalid
;
106 if (!(flags
& adns_qf_quoteok_query
)) {
108 if (!ll
) return adns_s_querydomaininvalid
;
109 } else if (!ctype_alpha(c
) && !ctype_digit(c
)) {
110 return adns_s_querydomaininvalid
;
113 if (ll
== sizeof(label
)) return adns_s_querydomaininvalid
;
116 if (!ll
) return adns_s_querydomaininvalid
;
117 if (nlabs
++ > 63) return adns_s_querydomaintoolong
;
119 memcpy(rqp
,label
,ll
); rqp
+= ll
;
125 st
= mkquery_footer(vb
,typei
->type
);
130 adns_status
adns__mkquery_frdgram(adns_state ads
, vbuf
*vb
, int *id_r
,
131 const byte
*qd_dgram
, int qd_dglen
, int qd_begin
,
132 adns_rrtype type
, adns_queryflags flags
) {
135 int lablen
, labstart
;
138 st
= mkquery_header(ads
,vb
,id_r
,qd_dglen
); if (st
) return st
;
142 adns__findlabel_start(&fls
,ads
,-1,0,qd_dgram
,qd_dglen
,qd_dglen
,qd_begin
,0);
144 st
= adns__findlabel_next(&fls
,&lablen
,&labstart
); assert(!st
);
147 MKQUERY_ADDB(lablen
);
148 memcpy(rqp
,qd_dgram
+labstart
,lablen
);
155 st
= mkquery_footer(vb
,type
);
160 void adns__querysend_tcp(adns_query qu
, struct timeval now
) {
166 if (qu
->ads
->tcpstate
!= server_ok
) return;
168 assert(qu
->state
== query_tcpw
);
170 length
[0]= (qu
->query_dglen
&0x0ff00U
) >>8;
171 length
[1]= (qu
->query_dglen
&0x0ff);
174 if (!adns__vbuf_ensure(&ads
->tcpsend
,ads
->tcpsend
.used
+qu
->query_dglen
+2)) return;
178 /* Reset idle timeout. */
179 ads
->tcptimeout
.tv_sec
= ads
->tcptimeout
.tv_usec
= 0;
181 if (ads
->tcpsend
.used
) {
184 iov
[0].iov_base
= length
;
186 iov
[1].iov_base
= qu
->query_dgram
;
187 iov
[1].iov_len
= qu
->query_dglen
;
188 adns__sigpipe_protect(qu
->ads
);
189 wr
= writev(qu
->ads
->tcpsocket
,iov
,2);
190 adns__sigpipe_unprotect(qu
->ads
);
192 if (!(errno
== EAGAIN
|| errno
== EINTR
|| errno
== ENOSPC
||
193 errno
== ENOBUFS
|| errno
== ENOMEM
)) {
194 adns__tcp_broken(ads
,"write",strerror(errno
));
202 r
= adns__vbuf_append(&ads
->tcpsend
,length
,2-wr
); assert(r
);
207 if (wr
<qu
->query_dglen
) {
208 r
= adns__vbuf_append(&ads
->tcpsend
,qu
->query_dgram
+wr
,qu
->query_dglen
-wr
); assert(r
);
212 static void query_usetcp(adns_query qu
, struct timeval now
) {
213 qu
->state
= query_tcpw
;
215 timevaladd(&qu
->timeout
,TCPWAITMS
);
216 LIST_LINK_TAIL(qu
->ads
->tcpw
,qu
);
217 adns__querysend_tcp(qu
,now
);
218 adns__tcp_tryconnect(qu
->ads
,now
);
221 void adns__query_send(adns_query qu
, struct timeval now
) {
222 struct sockaddr_in servaddr
;
226 assert(qu
->state
== query_tosend
);
227 if ((qu
->flags
& adns_qf_usevc
) || (qu
->query_dglen
> DNS_MAXUDP
)) {
228 query_usetcp(qu
,now
);
232 if (qu
->retries
>= UDPMAXRETRIES
) {
233 adns__query_fail(qu
,adns_s_timeout
);
237 serv
= qu
->udpnextserver
;
238 memset(&servaddr
,0,sizeof(servaddr
));
241 servaddr
.sin_family
= AF_INET
;
242 servaddr
.sin_addr
= ads
->servers
[serv
].addr
;
243 servaddr
.sin_port
= htons(DNS_PORT
);
245 r
= sendto(ads
->udpsocket
,qu
->query_dgram
,qu
->query_dglen
,0,
246 (const struct sockaddr
*)&servaddr
,sizeof(servaddr
));
247 if (r
<0 && errno
== EMSGSIZE
) { qu
->retries
= 0; query_usetcp(qu
,now
); return; }
248 if (r
<0) adns__warn(ads
,serv
,0,"sendto failed: %s",strerror(errno
));
251 timevaladd(&qu
->timeout
,UDPRETRYMS
);
252 qu
->udpsent
|= (1<<serv
);
253 qu
->udpnextserver
= (serv
+1)%ads
->nservers
;
255 LIST_LINK_TAIL(ads
->udpw
,qu
);