/* TCP connection management. */
-void adns__tcp_closenext(adns_state ads) {
+static void tcp_close(adns_state ads) {
int serv;
serv= ads->tcpserver;
close(ads->tcpsocket);
- ads->tcpstate= server_disconnected;
- ads->tcprecv.used= ads->tcpsend.used= 0;
- ads->tcpserver= (serv+1)%ads->nservers;
+ ads->tcpsocket= -1;
+ ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0;
}
void adns__tcp_broken(adns_state ads, const char *what, const char *why) {
int serv;
- adns_query qu, nqu;
assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok);
serv= ads->tcpserver;
- adns__warn(ads,serv,0,"TCP connection lost: %s: %s",what,why);
- adns__tcp_closenext(ads);
-
- for (qu= ads->timew.head; qu; qu= nqu) {
- nqu= qu->next;
- if (qu->state == query_tosend) continue;
- assert(qu->state == query_tcpwait || qu->state == query_tcpsent);
- qu->state= query_tcpwait;
- qu->tcpfailed |= (1<<serv);
- if (qu->tcpfailed == (1<<ads->nservers)-1) {
- LIST_UNLINK(ads->timew,qu);
- adns__query_fail(qu,adns_s_allservfail);
- }
- }
+ if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why);
+
+ tcp_close(ads);
+ ads->tcpstate= server_broken;
+ ads->tcpserver= (serv+1)%ads->nservers;
}
static void tcp_connected(adns_state ads, struct timeval now) {
adns__debug(ads,ads->tcpserver,0,"TCP connected");
ads->tcpstate= server_ok;
- for (qu= ads->timew.head; qu; qu= nqu) {
+ for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) {
nqu= qu->next;
- if (qu->state == query_tosend) continue;
- assert (qu->state == query_tcpwait);
- adns__query_tcp(qu,now);
+ assert(qu->state == query_tcpw);
+ adns__querysend_tcp(qu,now);
}
}
struct protoent *proto;
for (tries=0; tries<ads->nservers; tries++) {
- if (ads->tcpstate == server_connecting || ads->tcpstate == server_ok) return;
- assert(ads->tcpstate == server_disconnected);
+ switch (ads->tcpstate) {
+ case server_connecting:
+ case server_ok:
+ case server_broken:
+ return;
+ case server_disconnected:
+ break;
+ default:
+ abort();
+ }
+
assert(!ads->tcpsend.used);
assert(!ads->tcprecv.used);
+ assert(!ads->tcprecv_skip);
proto= getprotobyname("tcp");
if (!proto) { adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); return; }
r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr));
ads->tcpsocket= fd;
ads->tcpstate= server_connecting;
- if (r==0) { tcp_connected(ads,now); continue; }
- if (errno == EWOULDBLOCK || errno == EINPROGRESS) return;
+ if (r==0) { tcp_connected(ads,now); return; }
+ if (errno == EWOULDBLOCK || errno == EINPROGRESS) {
+ ads->tcptimeout= now;
+ timevaladd(&ads->tcptimeout,TCPCONNMS);
+ return;
+ }
adns__tcp_broken(ads,"connect",strerror(errno));
+ ads->tcpstate= server_disconnected;
}
}
static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf,
struct timeval now, struct timeval maxtime) {
+ /* tv_io may be 0 */
ldiv_t dr;
/*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n",
inter_maxto(tv_io,tvbuf,maxtime);
}
-void adns__timeouts(adns_state ads, int act,
- struct timeval **tv_io, struct timeval *tvbuf,
- struct timeval now) {
+static void timeouts_queue(adns_state ads, int act,
+ struct timeval **tv_io, struct timeval *tvbuf,
+ struct timeval now, struct query_queue *queue) {
adns_query qu, nqu;
-
- for (qu= ads->timew.head; qu; qu= nqu) {
+
+ for (qu= queue->head; qu; qu= nqu) {
nqu= qu->next;
if (!timercmp(&now,&qu->timeout,>)) {
- if (!tv_io) continue;
inter_maxtoabs(tv_io,tvbuf,now,qu->timeout);
} else {
- if (!act) continue;
- LIST_UNLINK(ads->timew,qu);
+ if (!act) {
+ tvbuf->tv_sec= 0;
+ tvbuf->tv_usec= 0;
+ *tv_io= tvbuf;
+ return;
+ }
+ LIST_UNLINK(*queue,qu);
if (qu->state != query_tosend) {
adns__query_fail(qu,adns_s_timeout);
} else {
adns__query_send(qu,now);
}
- nqu= ads->timew.head;
+ nqu= queue->head;
+ }
+ }
+}
+
+static void tcp_events(adns_state ads, int act,
+ struct timeval **tv_io, struct timeval *tvbuf,
+ struct timeval now) {
+ adns_query qu, nqu;
+
+ for (;;) {
+ switch (ads->tcpstate) {
+ case server_broken:
+ for (qu= ads->tcpw.head; qu; qu= nqu) {
+ nqu= qu->next;
+ assert(qu->state == query_tcpw);
+ if (qu->retries > ads->nservers) {
+ LIST_UNLINK(ads->tcpw,qu);
+ adns__query_fail(qu,adns_s_allservfail);
+ }
+ }
+ ads->tcpstate= server_disconnected;
+ case server_disconnected: /* fall through */
+ if (!ads->tcpw.head) return;
+ adns__tcp_tryconnect(ads,now);
+ break;
+ case server_ok:
+ if (ads->tcpw.head) return;
+ if (!ads->tcptimeout.tv_sec) {
+ assert(!ads->tcptimeout.tv_usec);
+ ads->tcptimeout= now;
+ timevaladd(&ads->tcptimeout,TCPIDLEMS);
+ }
+ case server_connecting: /* fall through */
+ if (!timercmp(&now,&ads->tcptimeout,>)) {
+ inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout);
+ return;
+ } {
+ /* TCP timeout has happened */
+ switch (ads->tcpstate) {
+ case server_connecting: /* failed to connect */
+ adns__tcp_broken(ads,"unable to make connection","timed out");
+ break;
+ case server_ok: /* idle timeout */
+ tcp_close(ads);
+ ads->tcpstate= server_disconnected;
+ return;
+ default:
+ abort();
+ }
+ }
+ break;
+ default:
+ abort();
}
}
-}
+}
+
+void adns__timeouts(adns_state ads, int act,
+ struct timeval **tv_io, struct timeval *tvbuf,
+ struct timeval now) {
+ timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw);
+ timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw);
+ tcp_events(ads,act,tv_io,tvbuf,now);
+}
void adns_firsttimeout(adns_state ads,
struct timeval **tv_io, struct timeval *tvbuf,
}
int adns_processreadable(adns_state ads, int fd, const struct timeval *now) {
- int skip, want, dgramlen, r, udpaddrlen, serv;
+ int want, dgramlen, r, udpaddrlen, serv, old_skip;
byte udpbuf[DNS_MAXUDP];
struct sockaddr_in udpaddr;
break;
case server_ok:
if (fd != ads->tcpsocket) break;
- skip= 0;
+ assert(!ads->tcprecv_skip);
for (;;) {
- if (ads->tcprecv.used<skip+2) {
- want= 2;
- } else {
- dgramlen= (ads->tcprecv.buf[skip]<<8) | ads->tcprecv.buf[skip+1];
- if (ads->tcprecv.used<skip+2+dgramlen) {
- want= 2+dgramlen;
+ if (ads->tcprecv.used >= ads->tcprecv_skip+2) {
+ dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) |
+ ads->tcprecv.buf[ads->tcprecv_skip+1]);
+ if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) {
+ old_skip= ads->tcprecv_skip;
+ ads->tcprecv_skip += 2+dgramlen;
+ adns__procdgram(ads, ads->tcprecv.buf+old_skip+2,
+ dgramlen, ads->tcpserver, 1,*now);
+ continue;
} else {
- adns__procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,ads->tcpserver,1,*now);
- skip+= 2+dgramlen; continue;
+ want= 2+dgramlen;
}
+ } else {
+ want= 2;
}
- ads->tcprecv.used -= skip;
- memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used);
- skip= 0;
+ ads->tcprecv.used -= ads->tcprecv_skip;
+ memmove(ads->tcprecv.buf,ads->tcprecv.buf+ads->tcprecv_skip,ads->tcprecv.used);
+ ads->tcprecv_skip= 0;
if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; }
assert(ads->tcprecv.used <= ads->tcprecv.avail);
if (ads->tcprecv.used == ads->tcprecv.avail) continue;
case server_connecting:
if (fd != ads->tcpsocket) break;
assert(ads->tcprecv.used==0);
+ assert(ads->tcprecv_skip==0);
for (;;) {
if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; }
r= read(ads->tcpsocket,&ads->tcprecv.buf,1);
void adns_globalsystemfailure(adns_state ads) {
adns__consistency(ads,0,cc_entex);
- while (ads->timew.head) {
- adns__query_fail(ads->timew.head, adns_s_systemfail);
- }
+ while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail);
+ while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail);
switch (ads->tcpstate) {
case server_connecting:
case server_ok:
- adns__tcp_closenext(ads);
+ adns__tcp_broken(ads,0,0);
break;
case server_disconnected:
break;
}
int adns_processany(adns_state ads) {
- int r;
+ int r, i;
struct timeval now;
struct pollfd pollfds[MAX_POLLFDS];
int npollfds;
* likely just to want to do a read on one or two fds anyway.
*/
npollfds= adns__pollfds(ads,pollfds);
+ for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events;
adns__fdevents(ads,
pollfds,npollfds,
0,0,0,0,
qu= *query_io;
if (!qu) {
- if (!ads->output.head) return EWOULDBLOCK;
- qu= ads->output.head;
+ if (ads->output.head) {
+ qu= ads->output.head;
+ } else if (ads->udpw.head || ads->tcpw.head) {
+ return EAGAIN;
+ } else {
+ return ESRCH;
+ }
} else {
- if (qu->id>=0) return EWOULDBLOCK;
+ if (qu->id>=0) return EAGAIN;
}
LIST_UNLINK(ads->output,qu);
*answer= qu->answer;
adns__consistency(ads,*query_io,cc_entex);
for (;;) {
r= adns__internal_check(ads,query_io,answer_r,context_r);
- if (r != EWOULDBLOCK) break;
+ if (r != EAGAIN) break;
maxfd= 0; tvp= 0;
FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds);
adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0);