10 adns_status adns__mkquery(adns_state ads, const char *owner, int ol, int id,
11 adns_rrtype type, adns_queryflags flags) {
12 /* Assembles a query packet in ads->rqbuf. */
14 byte label[255], *rqp;
17 #define MKQUERY_ADDB(b) *rqp++= (b)
18 #define MKQUERY_ADDW(w) (MKQUERY_ADDB(((w)>>8)&0x0ff), MKQUERY_ADDB((w)&0x0ff))
20 if (!adns__vbuf_ensure(&ads->rqbuf,DNSHDRSIZE+strlen(owner)+1+5))
21 return adns_s_nolocalmem;
25 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
26 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
27 MKQUERY_ADDW(1); /* QDCOUNT=1 */
28 MKQUERY_ADDW(0); /* ANCOUNT=0 */
29 MKQUERY_ADDW(0); /* NSCOUNT=0 */
30 MKQUERY_ADDW(0); /* ARCOUNT=0 */
31 p= owner; pe= owner+ol;
33 if (!*p) return adns_s_invaliddomain;
36 while (p!=pe && (c= *p++)!='.') {
38 if (!(flags & adns_qf_anyquote)) return adns_s_invaliddomain;
39 if (ctype_digit(p[0])) {
40 if (ctype_digit(p[1]) && ctype_digit(p[2])) {
41 c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
42 if (c >= 256) return adns_s_invaliddomain;
44 return adns_s_invaliddomain;
46 } else if (!(c= *p++)) {
47 return adns_s_invaliddomain;
50 if (!(flags & adns_qf_anyquote)) {
51 if (ctype_digit(c) || c == '-') {
52 if (!ll) return adns_s_invaliddomain;
53 } else if ((c < 'a' || c > 'z') && (c < 'A' && c > 'Z')) {
54 return adns_s_invaliddomain;
57 if (ll == sizeof(label)) return adns_s_invaliddomain;
60 if (!ll) return adns_s_invaliddomain;
61 if (nlabs++ > 63) return adns_s_invaliddomain;
63 memcpy(rqp,label,ll); rqp+= ll;
67 MKQUERY_ADDW(type & adns__rrt_typemask); /* QTYPE */
68 MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
70 ads->rqbuf.used= rqp - ads->rqbuf.buf;
71 assert(ads->rqbuf.used <= ads->rqbuf.avail);
76 void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now) {
77 /* Query must be in state tcpwait/timew; it will be moved to a new state
78 * if possible and no further processing can be done on it for now.
79 * (Resulting state is one of tcpwait/timew (if server not connected),
80 * tcpsent/timew, child/childw or done/output.)
82 * adns__tcp_tryconnect should already have been called - _tcp
83 * will only use an existing connection (if there is one), which it
84 * may break. If the conn list lost then the caller is responsible for any
85 * reestablishment and retry.
91 if (ads->tcpstate != server_ok) return;
93 length[0]= (qu->querylen&0x0ff00U) >>8;
94 length[1]= (qu->querylen&0x0ff);
96 if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->querylen+2)) return;
98 timevaladd(&now,TCPMS);
100 qu->state= query_tcpsent;
101 LIST_LINK_TAIL(ads->timew,qu);
103 if (ads->tcpsend.used) {
106 iov[0].iov_base= length;
108 iov[1].iov_base= qu->querymsg;
109 iov[1].iov_len= qu->querylen;
110 wr= writev(ads->tcpsocket,iov,2);
112 if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
113 errno == ENOBUFS || errno == ENOMEM)) {
114 adns__tcp_broken(ads,"write",strerror(errno));
122 r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
127 if (wr<qu->querylen) {
128 r= adns__vbuf_append(&ads->tcpsend,qu->querymsg+wr,qu->querylen-wr); assert(r);
132 static void query_usetcp(adns_state ads, adns_query qu, struct timeval now) {
133 timevaladd(&now,TCPMS);
135 qu->state= query_tcpwait;
136 LIST_LINK_TAIL(ads->timew,qu);
137 adns__query_tcp(ads,qu,now);
138 adns__tcp_tryconnect(ads,now);
141 void adns__query_udp(adns_state ads, adns_query qu, struct timeval now) {
142 /* Query must be in state udp/NONE; it will be moved to a new state,
143 * and no further processing can be done on it for now.
144 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
145 * tcpsent/timew, child/childw or done/output.)
147 struct sockaddr_in servaddr;
150 assert(qu->state == query_udp);
151 if ((qu->flags & adns_qf_usevc) || (qu->querylen > MAXUDPDGRAM)) {
152 query_usetcp(ads,qu,now);
156 if (qu->udpretries >= MAXUDPRETRIES) {
157 adns__query_fail(ads,qu,adns_s_timeout);
161 serv= qu->udpnextserver;
162 memset(&servaddr,0,sizeof(servaddr));
163 servaddr.sin_family= AF_INET;
164 servaddr.sin_addr= ads->servers[serv].addr;
165 servaddr.sin_port= htons(NSPORT);
167 r= sendto(ads->udpsocket,qu->querymsg,qu->querylen,0,&servaddr,sizeof(servaddr));
168 if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; }
169 if (r<0) adns__warn(ads,serv,"sendto failed: %s",strerror(errno));
171 timevaladd(&now,UDPRETRYMS);
173 qu->udpsent |= (1<<serv);
174 qu->udpnextserver= (serv+1)%ads->nservers;
176 LIST_LINK_TAIL(ads->timew,qu);
179 void adns__query_nomem(adns_state ads, adns_query qu) {
182 LIST_LINK_TAIL(ads->output,qu);
185 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat) {
188 if (!adns__vbuf_ensure(&qu->answer,sizeof(adns_answer))) {
189 adns__query_nomem(ads,qu);
192 ans= (adns_answer*)qu->answer.buf;
197 qu->answer.used= sizeof(adns_answer);
199 LIST_LINK_TAIL(ads->output,qu);