3 static void autosys(adns_state ads, struct timeval now) {
4 if (ads->iflags & adns_if_noautosys) return;
5 adns_callback(ads,-1,0,0,0);
8 static int callb_checkfd(int maxfd, const fd_set *fds, int fd) {
9 return maxfd<0 || !fds ? 1 :
10 fd<maxfd && FD_ISSET(fd,fds);
13 int adns_callback(adns_state ads, int maxfd,
14 const fd_set *readfds, const fd_set *writefds,
15 const fd_set *exceptfds) {
16 int skip, dgramlen, count;
17 enum adns__tcpstate oldtcpstate;
20 oldtcpstate= ads->tcpstate;
22 if (ads->tcpstate == server_connecting) {
23 if (callb_checkfd(maxfd,writefds,ads->tcpsocket)) {
25 assert(ads->tcprecv.used==0);
26 vbuf_ensure(&ads->tcprecv,1);
27 if (ads->tcprecv.buf) {
28 r= read(ads->tcpsocket,&ads->tcprecv.buf,1);
29 if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) {
30 diag("nameserver %s TCP connection made",
31 inet_ntoa(ads->servers[ads->tcpserver].addr));
32 ads->tcpstate= server_connected;
34 tcpserver_broken(ads,"connect/read","sent data before first request");
35 } else if (errno!=EINTR) {
36 tcpserver_broken(ads,"connect",strerror(errno));
41 if (ads->tcpstate == server_connected) {
42 if (oldtcpstate == server_connected)
43 count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) +
44 callb_checkfd(maxfd,exceptfds,ads->tcpsocket) +
45 (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket));
46 if (oldtcpstate != server_connected || callb_checkfd(maxfd,readfds,ads->tcpsocket)) {
49 if (ads->tcprecv.used<skip+2) {
52 dgramlen= (ads->tcprecv.buf[skip]<<8) | ads->tcprecv.buf[skip+1];
53 if (ads->tcprecv.used<skip+2+dgramlen) {
56 procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,-1);
57 skip+= 2+dgramlen; continue;
60 Ads->tcprecv.used -= skip;
61 memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used);
62 vbuf_ensure(&ads->tcprecv,want);
63 if (ads->tcprecv.used >= ads->tcprecv.avail) break;
64 r= read(ads->tcpsocket,
65 ads->tcprecv.buf+ads->tcprecv.used,
66 ads->tcprecv.avail-ads->tcprecv.used);
68 ads->tcprecv.used+= r;
71 if (errno==EAGAIN || errno==EWOULDBLOCK || errno==ENOMEM) break;
72 if (errno==EINTR) continue;
74 tcpserver_broken(ads->tcpserver,"read",r?strerror(errno):"closed");
78 } else if (callb_checkfd(maxfd,exceptfds,ads->tcpsocket)) {
79 tcpserver_broken(ads->tcpserver,"select","exceptional condition detected");
80 } else if (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)) {
81 r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used);
83 if (errno!=EAGAIN && errno!=EWOULDBLOCK && errno!=ENOMEM && errno!=EINTR) {
84 tcpserver_broken(ads->tcpserver,"write",strerror(errno));
87 ads->tcpsend.used -= r;
88 memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used);
104 vbuf_ensure(&ads->tcprecv,2);
105 vbuf_ensure(&ads->tcprecv,
106 if (ads->tcprecv.avail<2) break;
107 if (ads->tcprecv.used
109 if (ads->tcprecv.used<2 && ads->tcprecv.avail
110 if (ads->tcprecv.used<2 && ads->tcprecv.avail
111 r= read(ads->tcpsocket,
112 if (adns->tcprecv.used<2) {
115 if (ads->tcpstate != server_disc) {
119 if (maxfd<0 || !readfds || (FD_ISSET
124 diag("nameserver #%d (%s) TCP connection died: %s",
125 inet_ntoa(ads->servers[tcpserver].addr),
127 static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf,
128 struct timeval maxto) {
132 if (!rbuf) { *tvbuf= maxto; *tv_io= tvbuf; return; }
133 if (timercmp(rbuf,&maxto,>)) *rbuf= maxto;
136 static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf,
137 struct timeval now, struct timeval maxtime) {
140 maxtime.tv_sec -= (now.tv_sec-1);
141 maxtime.tv_usec += (1000-now.tv_usec);
142 dr= ldiv(maxtime.tv_usec,1000);
143 maxtime.tv_sec += dr.quot;
144 maxtime.tv_usec -= dr.rem;
145 inter_maxto(tv_io,tvbuf,maxtime);
148 static void localresourcerr(struct timeval **tv_io, struct timeval *tvbuf,
149 const char *syscall) {
150 struct timeval tvto_lr;
152 diag(ads,"local system resources scarce (during %s): %s",syscall,strerror(errno));
153 timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS);
154 inter_maxto(tv_io, tvbuf, tvto_lr);
158 static void inter_addfd(int *maxfd, fd_set *fds, int fd) {
159 if (fd>=*maxfd) *maxfd= fd+1;
163 void adns_interest(adns_state ads, int *maxfd,
164 fd_set *readfds, fd_set *writefds, fd_set *exceptfds,
165 struct timeval **tv_io, struct timeval *tvbuf) {
170 r= gettimeofday(&now,0);
171 if (r) { localresourcerr(tv_io,tvbuf,"gettimeofday"); return; }
173 for (qu= ads->timew; qu; qu= nqu) {
175 if (timercmp(&now,qu->timeout,>)) {
176 DLIST_UNLINK(ads->timew,qu);
177 if (qu->nextudpserver == -1) {
178 query_fail(ads,qu,adns_s_notresponding);
180 DLIST_LINKTAIL(ads->tosend,qu);
183 inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
187 for (qu= ads->tosend; qu; qu= nqu) {
189 quproc_tosend(ads,qu,now);
192 inter_addfd(maxfd,readfds,ads->udpsocket);
193 switch (ads->tcpstate) {
196 case server_connecting:
197 inter_addfd(maxfd,writefds,ads->tcpsocket);
199 case server_connected:
200 inter_addfd(maxfd,readfds,ads->tcpsocket);
201 inter_addfd(maxfd,exceptfds,ads->tcpsocket);
202 if (ads->opbufused) inter_addfd(maxfd,writefds,ads->tcpsocket);
209 static int internal_check(adns_state ads,
210 adns_query *query_io,
211 adns_answer **answer,
217 if (!ads->output.head) return EWOULDBLOCK;
218 qu= ads->output.head;
220 if (qu->id>=0) return EWOULDBLOCK;
222 LIST_UNLINK(ads->output,qu);
224 if (context_r) *context_r= qu->context;
229 int adns_wait(adns_state ads,
230 adns_query *query_io,
231 adns_answer **answer_r,
233 int r, maxfd, rsel, rcb;
234 fd_set readfds, writefds, exceptfds;
235 struct timeval tvbuf, *tvp;
238 r= internal_check(ads,query_io,answer_r,context_r);
239 if (r && r != EWOULDBLOCK) return r;
240 FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
242 adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf);
243 rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
244 if (rsel==-1) return r;
245 rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds);
250 int adns_check(adns_state ads,
251 adns_query *query_io,
252 adns_answer **answer_r,
255 return internal_check(ads,query_io,answer_r,context_r);