* - user-visible check/wait and event-loop-related functions
*/
/*
- * This file is
- * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
- *
- * It is part of adns, which is
- * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
- * Copyright (C) 1999 Tony Finch <dot@dotat.at>
+ * This file is part of adns, which is
+ * Copyright (C) 1997-2000,2003,2006 Ian Jackson
+ * Copyright (C) 1999-2000,2003,2006 Tony Finch
+ * Copyright (C) 1991 Massachusetts Institute of Technology
+ * (See the file INSTALL for full details.)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#include <arpa/inet.h>
#include "internal.h"
+#include "tvarith.h"
/* TCP connection management. */
-void adns__tcp_closenext(adns_state ads) {
- int serv;
-
- serv= ads->tcpserver;
+static void tcp_close(adns_state ads) {
close(ads->tcpsocket);
- ads->tcpstate= server_disconnected;
+ ads->tcpsocket= -1;
ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0;
- ads->tcpserver= (serv+1)%ads->nservers;
}
void adns__tcp_broken(adns_state ads, const char *what, const char *why) {
int serv;
- adns_query qu, nqu;
+ adns_query qu;
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);
+
+ if (ads->tcpstate == server_connecting) {
+ /* Counts as a retry for all the queries waiting for TCP. */
+ for (qu= ads->tcpw.head; qu; qu= qu->next)
+ qu->retries++;
}
+
+ 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;
+ assert(qu->state == query_tcpw);
+ adns__querysend_tcp(qu,now);
+ }
+}
+
+static void tcp_broken_events(adns_state ads) {
+ adns_query qu, nqu;
+
+ assert(ads->tcpstate == server_broken);
+ for (qu= ads->tcpw.head; qu; 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);
+ if (qu->retries > ads->nservers) {
+ LIST_UNLINK(ads->tcpw,qu);
+ adns__query_fail(qu,adns_s_allservfail);
+ }
}
+ ads->tcpstate= server_disconnected;
}
void adns__tcp_tryconnect(adns_state ads, struct timeval now) {
int r, fd, tries;
- struct sockaddr_in addr;
+ adns_rr_addr *addr;
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; }
- fd= socket(AF_INET,SOCK_STREAM,proto->p_proto);
+ if (!proto) {
+ adns__diag(ads,-1,0,"unable to find protocol no. for TCP !");
+ return;
+ }
+ addr = &ads->servers[ads->tcpserver];
+ fd= socket(addr->addr.sa.sa_family, SOCK_STREAM, proto->p_proto);
if (fd<0) {
adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno));
return;
}
r= adns__setnonblock(ads,fd);
if (r) {
- adns__diag(ads,-1,0,"cannot make TCP socket nonblocking: %s",strerror(r));
+ adns__diag(ads,-1,0,"cannot make TCP socket nonblocking:"
+ " %s",strerror(r));
close(fd);
return;
}
- memset(&addr,0,sizeof(addr));
- addr.sin_family= AF_INET;
- addr.sin_port= htons(DNS_PORT);
- addr.sin_addr= ads->servers[ads->tcpserver].addr;
- r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr));
+ r= connect(fd,&addr->addr.sa,addr->len);
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));
+ tcp_broken_events(ads);
}
}
return;
}
+static void inter_immed(struct timeval **tv_io, struct timeval *tvbuf) {
+ struct timeval *rbuf;
+
+ if (!tv_io) return;
+
+ rbuf= *tv_io;
+ if (!rbuf) { *tv_io= rbuf= tvbuf; }
+
+ timerclear(rbuf);
+}
+
static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf,
struct timeval maxto) {
struct timeval *rbuf;
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) { inter_immed(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) {
+ for (;;) {
+ switch (ads->tcpstate) {
+ case server_broken:
+ if (!act) { inter_immed(tv_io,tvbuf); return; }
+ tcp_broken_events(ads);
+ case server_disconnected: /* fall through */
+ if (!ads->tcpw.head) return;
+ if (!act) { inter_immed(tv_io,tvbuf); 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 (!act || !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();
+ }
+ }
+ return;
+}
+
+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,
switch (ads->tcpstate) {
case server_disconnected:
+ case server_broken:
return 1;
case server_connecting:
pollfds_buf[1].events= POLLOUT;
break;
case server_ok:
- pollfds_buf[1].events= ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI;
+ pollfds_buf[1].events=
+ ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI;
break;
default:
abort();
switch (ads->tcpstate) {
case server_disconnected:
+ case server_broken:
case server_connecting:
break;
case server_ok:
if (fd != ads->tcpsocket) break;
assert(!ads->tcprecv_skip);
- for (;;) {
+ do {
if (ads->tcprecv.used >= ads->tcprecv_skip+2) {
dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) |
ads->tcprecv.buf[ads->tcprecv_skip+1]);
want= 2;
}
ads->tcprecv.used -= ads->tcprecv_skip;
- memmove(ads->tcprecv.buf,ads->tcprecv.buf+ads->tcprecv_skip,ads->tcprecv.used);
+ 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 (errno_resources(errno)) { r= errno; goto xit; }
}
adns__tcp_broken(ads,"read",r?strerror(errno):"closed");
- r= 0; goto xit;
}
- } /* never reached */
+ } while (ads->tcpstate == server_ok);
+ r= 0; goto xit;
default:
abort();
}
}
if (udpaddrlen != sizeof(udpaddr)) {
adns__diag(ads,-1,0,"datagram received with wrong address length %d"
- " (expected %d)", udpaddrlen,sizeof(udpaddr));
+ " (expected %lu)", udpaddrlen,
+ (unsigned long)sizeof(udpaddr));
continue;
}
if (udpaddr.sin_family != AF_INET) {
continue;
}
if (ntohs(udpaddr.sin_port) != DNS_PORT) {
- adns__diag(ads,-1,0,"datagram received from wrong port %u (expected %u)",
- ntohs(udpaddr.sin_port),DNS_PORT);
+ adns__diag(ads,-1,0,"datagram received from wrong port"
+ " %u (expected %u)", ntohs(udpaddr.sin_port),DNS_PORT);
continue;
}
for (serv= 0;
serv < ads->nservers &&
- ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr;
+ (assert(ads->servers[serv].addr.sa.sa_family==AF_INET),
+ ads->servers[serv].addr.inet.sin_addr.s_addr !=
+ udpaddr.sin_addr.s_addr);
serv++);
if (serv >= ads->nservers) {
adns__warn(ads,-1,0,"datagram received from unknown nameserver %s",
switch (ads->tcpstate) {
case server_disconnected:
+ case server_broken:
break;
case server_connecting:
if (fd != ads->tcpsocket) break;
r= 0; goto xit;
} /* not reached */
case server_ok:
- if (!(ads->tcpsend.used && fd == ads->tcpsocket)) break;
- for (;;) {
+ if (fd != ads->tcpsocket) break;
+ while (ads->tcpsend.used) {
adns__sigpipe_protect(ads);
r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used);
adns__sigpipe_unprotect(ads);
ads->tcpsend.used -= r;
memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used);
}
- } /* not reached */
+ }
+ r= 0;
+ goto xit;
default:
abort();
}
return r;
}
-int adns_processexceptional(adns_state ads, int fd, const struct timeval *now) {
+int adns_processexceptional(adns_state ads, int fd,
+ const struct timeval *now) {
adns__consistency(ads,0,cc_entex);
switch (ads->tcpstate) {
case server_disconnected:
+ case server_broken:
break;
case server_connecting:
case server_ok:
static void fd_event(adns_state ads, int fd,
int revent, int pollflag,
int maxfd, const fd_set *fds,
- int (*func)(adns_state, int fd, const struct timeval *now),
+ int (*func)(adns_state, int fd,
+ const struct timeval *now),
struct timeval now, int *r_r) {
int r;
if (r_r) {
*r_r= r;
} else {
- adns__diag(ads,-1,0,"process fd failed after select: %s",strerror(errno));
+ adns__diag(ads,-1,0,"process fd failed after select:"
+ " %s",strerror(errno));
adns_globalsystemfailure(ads);
}
}
fd= pollfds[i].fd;
if (fd >= maxfd) maxfd= fd+1;
revents= pollfds[i].revents;
- fd_event(ads,fd, revents,POLLIN, maxfd,readfds, adns_processreadable,now,r_r);
- fd_event(ads,fd, revents,POLLOUT, maxfd,writefds, adns_processwriteable,now,r_r);
- fd_event(ads,fd, revents,POLLPRI, maxfd,exceptfds, adns_processexceptional,now,r_r);
+#define EV(pollfl,fds,how) \
+ fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r)
+ EV( POLLIN, readfds, readable );
+ EV( POLLOUT, writefds, writeable );
+ EV( POLLPRI, exceptfds, exceptional );
+#undef EV
}
}
if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) {
/* The caller is planning to sleep. */
adns__must_gettimeofday(ads,&now,&tv_nowbuf);
- if (!now) goto xit;
- adns__timeouts(ads, 1, tv_mod,tv_tobuf, *now);
+ if (!now) { inter_immed(tv_mod,tv_tobuf); goto xit; }
+ adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now);
}
npollfds= adns__pollfds(ads,pollfds);
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:
+ case server_broken:
break;
default:
abort();
* 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;
+ for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events & ~POLLPRI;
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);
+ assert(tvp);
rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp);
if (rsel==-1) {
if (errno == EINTR) {
~ianmdlvl / adns.git / blobdiff