11 adns_status adns__mkquery(adns_state ads, vbuf *vb,
12 const char *owner, int ol, int *id_r,
13 const typeinfo *typei, adns_queryflags flags) {
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))
22 if (!adns__vbuf_ensure(vb,DNS_HDRSIZE+strlen(owner)+1+5))
23 return adns_s_nolocalmem;
26 *id_r= id= (ads->nextid++) & 0x0ffff;
29 MKQUERY_ADDB(0x01); /* QR=Q(0), OPCODE=QUERY(0000), !AA, !TC, RD */
30 MKQUERY_ADDB(0x00); /* !RA, Z=000, RCODE=NOERROR(0000) */
31 MKQUERY_ADDW(1); /* QDCOUNT=1 */
32 MKQUERY_ADDW(0); /* ANCOUNT=0 */
33 MKQUERY_ADDW(0); /* NSCOUNT=0 */
34 MKQUERY_ADDW(0); /* ARCOUNT=0 */
35 p= owner; pe= owner+ol;
37 if (!*p) return adns_s_invaliddomain;
40 while (p!=pe && (c= *p++)!='.') {
42 if (!(flags & adns_qf_anyquote)) return adns_s_invaliddomain;
43 if (ctype_digit(p[0])) {
44 if (ctype_digit(p[1]) && ctype_digit(p[2])) {
45 c= (*p++ - '0')*100 + (*p++ - '0')*10 + (*p++ - '0');
46 if (c >= 256) return adns_s_invaliddomain;
48 return adns_s_invaliddomain;
50 } else if (!(c= *p++)) {
51 return adns_s_invaliddomain;
54 if (!(flags & adns_qf_anyquote)) {
55 if (ctype_digit(c) || c == '-') {
56 if (!ll) return adns_s_invaliddomain;
57 } else if (!ctype_alpha(c)) {
58 return adns_s_invaliddomain;
61 if (ll == sizeof(label)) return adns_s_invaliddomain;
64 if (!ll) return adns_s_invaliddomain;
65 if (nlabs++ > 63) return adns_s_invaliddomain;
67 memcpy(rqp,label,ll); rqp+= ll;
71 MKQUERY_ADDW(typei->type & adns__rrt_typemask); /* QTYPE */
72 MKQUERY_ADDW(DNS_CLASS_IN); /* QCLASS=IN */
74 vb->used= rqp - vb->buf;
75 assert(vb->used <= vb->avail);
80 void adns__query_tcp(adns_state ads, adns_query qu, struct timeval now) {
81 /* Query must be in state tcpwait/timew; it will be moved to a new state
82 * if possible and no further processing can be done on it for now.
83 * (Resulting state is one of tcpwait/timew (if server not connected),
84 * tcpsent/timew, child/childw or done/output.)
86 * adns__tcp_tryconnect should already have been called - _tcp
87 * will only use an existing connection (if there is one), which it
88 * may break. If the conn list lost then the caller is responsible for any
89 * reestablishment and retry.
95 if (ads->tcpstate != server_ok) return;
97 length[0]= (qu->query_dglen&0x0ff00U) >>8;
98 length[1]= (qu->query_dglen&0x0ff);
100 if (!adns__vbuf_ensure(&ads->tcpsend,ads->tcpsend.used+qu->query_dglen+2)) return;
102 timevaladd(&now,TCPMS);
104 qu->state= query_tcpsent;
105 LIST_LINK_TAIL(ads->timew,qu);
107 if (ads->tcpsend.used) {
110 iov[0].iov_base= length;
112 iov[1].iov_base= qu->query_dgram;
113 iov[1].iov_len= qu->query_dglen;
114 wr= writev(ads->tcpsocket,iov,2);
116 if (!(errno == EAGAIN || errno == EINTR || errno == ENOSPC ||
117 errno == ENOBUFS || errno == ENOMEM)) {
118 adns__tcp_broken(ads,"write",strerror(errno));
126 r= adns__vbuf_append(&ads->tcpsend,length,2-wr); assert(r);
131 if (wr<qu->query_dglen) {
132 r= adns__vbuf_append(&ads->tcpsend,qu->query_dgram+wr,qu->query_dglen-wr); assert(r);
136 static void query_usetcp(adns_state ads, adns_query qu, struct timeval now) {
137 timevaladd(&now,TCPMS);
139 qu->state= query_tcpwait;
140 LIST_LINK_TAIL(ads->timew,qu);
141 adns__query_tcp(ads,qu,now);
142 adns__tcp_tryconnect(ads,now);
145 void adns__query_udp(adns_state ads, adns_query qu, struct timeval now) {
146 /* Query must be in state udp/NONE; it will be moved to a new state,
147 * and no further processing can be done on it for now.
148 * (Resulting state is one of udp/timew, tcpwait/timew (if server not connected),
149 * tcpsent/timew, child/childw or done/output.)
151 struct sockaddr_in servaddr;
154 assert(qu->state == query_udp);
155 if ((qu->flags & adns_qf_usevc) || (qu->query_dglen > DNS_MAXUDP)) {
156 query_usetcp(ads,qu,now);
160 if (qu->udpretries >= UDPMAXRETRIES) {
161 adns__query_fail(ads,qu,adns_s_timeout);
165 serv= qu->udpnextserver;
166 memset(&servaddr,0,sizeof(servaddr));
167 servaddr.sin_family= AF_INET;
168 servaddr.sin_addr= ads->servers[serv].addr;
169 servaddr.sin_port= htons(DNS_PORT);
171 r= sendto(ads->udpsocket,qu->query_dgram,qu->query_dglen,0,&servaddr,sizeof(servaddr));
172 if (r<0 && errno == EMSGSIZE) { query_usetcp(ads,qu,now); return; }
173 if (r<0) adns__warn(ads,serv,0,"sendto failed: %s",strerror(errno));
175 timevaladd(&now,UDPRETRYMS);
177 qu->udpsent |= (1<<serv);
178 qu->udpnextserver= (serv+1)%ads->nservers;
180 LIST_LINK_TAIL(ads->timew,qu);
183 static void adns__query_done(adns_state ads, adns_query qu) {
188 qu->answer= ans= realloc(qu->answer,
189 MEM_ROUND(MEM_ROUND(sizeof(*ans)) +
190 qu->interim_allocd));
191 qu->final_allocspace= (byte*)qu->answer + MEM_ROUND(sizeof(*ans));
193 adns__makefinal_str(qu,&ans->cname);
195 adns__makefinal_block(qu,&ans->rrs.untyped,ans->rrsz*ans->nrrs);
196 for (i=0; i<ans->nrrs; i++)
197 qu->typei->makefinal(ads,qu,ans->rrs.bytes+ans->rrsz*i);
200 for (an= qu->allocations; an; an= ann) { ann= an->next; free(an); }
202 adns__vbuf_free(&qu->vb);
205 LIST_LINK_TAIL(ads->output,qu);
208 void adns__reset_cnameonly(adns_state ads, adns_query qu) {
209 assert(qu->final_allocspace);
212 qu->interim_allocd= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
215 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat) {
216 adns__reset_cnameonly(ads,qu);
217 qu->answer->status= stat;
218 adns__query_done(ads,qu);