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 static void adns__query_done(adns_state ads, adns_query qu) {
184 qu->answer= ans= realloc(qu->answer,
185 MEM_ROUND(MEM_ROUND(sizeof(*ans)) +
186 qu->interim_allocd));
187 qu->final_used= MEM_ROUND(sizeof(*ans));
189 adns__makefinal_str(qu,&ans->cname);
191 adns__makefinal_block(qu,&ans->rrs.untyped,ans->rrsz*ans->nrrs);
192 for (i=0; i<ans->nrrs; i++)
193 qu->typei->makefinal(ads,qu,ans->rrs.bytes+ans->rrsz*i);
196 for (an= qu->allocations; an; an= ann) { ann= an->next; free(an); }
198 adns__vbuf_free(&qu->vb);
201 LIST_LINK_TAIL(ads->output,qu);
204 void adns__reset_cnameonly(adns_state ads, adns_query qu) {
207 qu->permalloclen= qu->answer->cname ? MEM_ROUND(strlen(qu->answer->cname)+1) : 0;
210 void adns__query_fail(adns_state ads, adns_query qu, adns_status stat) {
211 adns__reset_cnameonly(ads,qu);
212 qu->answer->status= stat;
213 qu->answer->type= qu->type;
214 adns__query_done(ads,qu,stat);