11 adns_status
adns__mkquery(adns_state ads
, const char *owner
, int ol
, int id
,
12 const typeinfo
*typei
, adns_queryflags flags
) {
13 /* Assembles a query packet in ads->rqbuf. */
15 byte label
[255], *rqp
;
18 #define MKQUERY_ADDB(b) *rqp++= (b)
19 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
21 if (!adns__vbuf_ensure(&ads
->rqbuf
,DNS_HDRSIZE
+strlen(owner
)+1+5))
22 return adns_s_nolocalmem
;
26 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
27 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
28 MKQUERY_ADDW(1); /* QDCOUNT=1 */
29 MKQUERY_ADDW(0); /* ANCOUNT=0 */
30 MKQUERY_ADDW(0); /* NSCOUNT=0 */
31 MKQUERY_ADDW(0); /* ARCOUNT=0 */
32 p
= owner
; pe
= owner
+ol
;
34 if (!*p
) return adns_s_invaliddomain
;
37 while (p
!=pe
&& (c
= *p
++)!='.') {
39 if (!(flags
& adns_qf_anyquote
)) return adns_s_invaliddomain
;
40 if (ctype_digit(p
[0])) {
41 if (ctype_digit(p
[1]) && ctype_digit(p
[2])) {
42 c
= (*p
++ - '0')*100 + (*p
++ - '0')*10 + (*p
++ - '0');
43 if (c
>= 256) return adns_s_invaliddomain
;
45 return adns_s_invaliddomain
;
47 } else if (!(c
= *p
++)) {
48 return adns_s_invaliddomain
;
51 if (!(flags
& adns_qf_anyquote
)) {
52 if (ctype_digit(c
) || c
== '-') {
53 if (!ll
) return adns_s_invaliddomain
;
54 } else if (!ctype_alpha(c
)) {
55 return adns_s_invaliddomain
;
58 if (ll
== sizeof(label
)) return adns_s_invaliddomain
;
61 if (!ll
) return adns_s_invaliddomain
;
62 if (nlabs
++ > 63) return adns_s_invaliddomain
;
64 memcpy(rqp
,label
,ll
); rqp
+= ll
;
68 MKQUERY_ADDW(typei
->type
& adns__rrt_typemask
); /* QTYPE */
69 MKQUERY_ADDW(DNS_CLASS_IN
); /* QCLASS=IN */
71 ads
->rqbuf
.used
= rqp
- ads
->rqbuf
.buf
;
72 assert(ads
->rqbuf
.used
<= ads
->rqbuf
.avail
);
77 void adns__query_tcp(adns_state ads
, adns_query qu
, struct timeval now
) {
78 /* Query must be in state tcpwait/timew; it will be moved to a new state
79 * if possible and no further processing can be done on it for now.
80 * (Resulting state is one of tcpwait/timew (if server not connected),
81 * tcpsent/timew, child/childw or done/output.)
83 * adns__tcp_tryconnect should already have been called - _tcp
84 * will only use an existing connection (if there is one), which it
85 * may break. If the conn list lost then the caller is responsible for any
86 * reestablishment and retry.
92 if (ads
->tcpstate
!= server_ok
) return;
94 length
[0]= (qu
->querylen
&0x0ff00U
) >>8;
95 length
[1]= (qu
->querylen
&0x0ff);
97 if (!adns__vbuf_ensure(&ads
->tcpsend
,ads
->tcpsend
.used
+qu
->querylen
+2)) return;
99 timevaladd(&now
,TCPMS
);
101 qu
->state
= query_tcpsent
;
102 LIST_LINK_TAIL(ads
->timew
,qu
);
104 if (ads
->tcpsend
.used
) {
107 iov
[0].iov_base
= length
;
109 iov
[1].iov_base
= qu
->querymsg
;
110 iov
[1].iov_len
= qu
->querylen
;
111 wr
= writev(ads
->tcpsocket
,iov
,2);
113 if (!(errno
== EAGAIN
|| errno
== EINTR
|| errno
== ENOSPC
||
114 errno
== ENOBUFS
|| errno
== ENOMEM
)) {
115 adns__tcp_broken(ads
,"write",strerror(errno
));
123 r
= adns__vbuf_append(&ads
->tcpsend
,length
,2-wr
); assert(r
);
128 if (wr
<qu
->querylen
) {
129 r
= adns__vbuf_append(&ads
->tcpsend
,qu
->querymsg
+wr
,qu
->querylen
-wr
); assert(r
);
133 static void query_usetcp(adns_state ads
, adns_query qu
, struct timeval now
) {
134 timevaladd(&now
,TCPMS
);
136 qu
->state
= query_tcpwait
;
137 LIST_LINK_TAIL(ads
->timew
,qu
);
138 adns__query_tcp(ads
,qu
,now
);
139 adns__tcp_tryconnect(ads
,now
);
142 void adns__query_udp(adns_state ads
, adns_query qu
, struct timeval now
) {
143 /* Query must be in state udp/NONE; it will be moved to a new state,
144 * and no further processing can be done on it for now.
145 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
146 * tcpsent/timew, child/childw or done/output.)
148 struct sockaddr_in servaddr
;
151 assert(qu
->state
== query_udp
);
152 if ((qu
->flags
& adns_qf_usevc
) || (qu
->querylen
> DNS_MAXUDP
)) {
153 query_usetcp(ads
,qu
,now
);
157 if (qu
->udpretries
>= UDPMAXRETRIES
) {
158 adns__query_fail(ads
,qu
,adns_s_timeout
);
162 serv
= qu
->udpnextserver
;
163 memset(&servaddr
,0,sizeof(servaddr
));
164 servaddr
.sin_family
= AF_INET
;
165 servaddr
.sin_addr
= ads
->servers
[serv
].addr
;
166 servaddr
.sin_port
= htons(DNS_PORT
);
168 r
= sendto(ads
->udpsocket
,qu
->querymsg
,qu
->querylen
,0,&servaddr
,sizeof(servaddr
));
169 if (r
<0 && errno
== EMSGSIZE
) { query_usetcp(ads
,qu
,now
); return; }
170 if (r
<0) adns__warn(ads
,serv
,"sendto failed: %s",strerror(errno
));
172 timevaladd(&now
,UDPRETRYMS
);
174 qu
->udpsent
|= (1<<serv
);
175 qu
->udpnextserver
= (serv
+1)%ads
->nservers
;
177 LIST_LINK_TAIL(ads
->timew
,qu
);
180 void adns__query_finish(adns_state ads
, adns_query qu
, adns_status stat
) {
184 newbuf
= realloc(qu
->ans
.buf
,qu
->ans
.used
);
185 if (newbuf
) qu
->ans
.buf
= newbuf
;
186 ans
= (adns_answer
*)qu
->ans
.buf
;
188 ans
->cname
= qu
->cnameoff
<0 ?
0 : qu
->ans
.buf
+ qu
->cnameoff
;
189 ans
->rrs
.str
= qu
->rrsoff
<0 ?
0 : (char **)(qu
->ans
.buf
+ qu
->rrsoff
);
191 LIST_LINK_TAIL(ads
->output
,qu
);
194 void adns__query_fail(adns_state ads
, adns_query qu
, adns_status stat
) {
197 qu
->ans
.used
= sizeof(adns_answer
);
200 ans
= (adns_answer
*)qu
->ans
.buf
;
203 adns__query_finish(ads
,qu
,stat
);