* - 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) 1997-2000,2003,2006,2014-2016 Ian Jackson
+ * Copyright (C) 2014 Mark Wooding
+ * 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
- * the Free Software Foundation; either version 2, or (at your option)
+ * the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ * along with this program; if not, write to the Free Software Foundation.
*/
#include <errno.h>
/* TCP connection management. */
static void tcp_close(adns_state ads) {
- int serv;
-
- serv= ads->tcpserver;
close(ads->tcpsocket);
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;
assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok);
serv= ads->tcpserver;
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_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;
+ 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++) {
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); return; }
return;
}
adns__tcp_broken(ads,"connect",strerror(errno));
- ads->tcpstate= server_disconnected;
+ tcp_broken_events(ads);
}
}
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:
if (!act) { inter_immed(tv_io,tvbuf); return; }
- 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;
+ tcp_broken_events(ads);
case server_disconnected: /* fall through */
if (!ads->tcpw.head) return;
if (!act) { inter_immed(tv_io,tvbuf); return; }
struct timeval now) {
adns__consistency(ads,0,cc_entex);
adns__timeouts(ads, 0, tv_io,tvbuf, now);
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
}
void adns_processtimeouts(adns_state ads, const struct timeval *now) {
adns__consistency(ads,0,cc_entex);
adns__must_gettimeofday(ads,&now,&tv_buf);
if (now) adns__timeouts(ads, 1, 0,0, *now);
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
}
/* fd handling functions. These are the top-level of the real work of
int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) {
/* Returns the number of entries filled in. Always zeroes revents. */
+ int nwanted=0;
+#define ADD_POLLFD(wantfd, wantevents) do{ \
+ pollfds_buf[nwanted].fd= (wantfd); \
+ pollfds_buf[nwanted].events= (wantevents); \
+ pollfds_buf[nwanted].revents= 0; \
+ nwanted++; \
+ }while(0)
- assert(MAX_POLLFDS==2);
+ int i;
- pollfds_buf[0].fd= ads->udpsocket;
- pollfds_buf[0].events= POLLIN;
- pollfds_buf[0].revents= 0;
+ assert(MAX_POLLFDS == MAXUDP + 1);
+
+ for (i=0; i<ads->nudpsockets; i++)
+ ADD_POLLFD(ads->udpsockets[i].fd, POLLIN);
switch (ads->tcpstate) {
case server_disconnected:
- return 1;
+ case server_broken:
+ break;
case server_connecting:
- pollfds_buf[1].events= POLLOUT;
+ ADD_POLLFD(ads->tcpsocket, POLLOUT);
break;
case server_ok:
- pollfds_buf[1].events= ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI;
+ ADD_POLLFD(ads->tcpsocket,
+ ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI);
break;
default:
abort();
}
- pollfds_buf[1].fd= ads->tcpsocket;
- return 2;
+ assert(nwanted<=MAX_POLLFDS);
+#undef ADD_POLLFD
+ return nwanted;
}
int adns_processreadable(adns_state ads, int fd, const struct timeval *now) {
- int want, dgramlen, r, udpaddrlen, serv, old_skip;
+ int want, dgramlen, r, i, serv, old_skip;
+ socklen_t udpaddrlen;
byte udpbuf[DNS_MAXUDP];
- struct sockaddr_in udpaddr;
+ char addrbuf[ADNS_ADDR2TEXT_BUFLEN];
+ struct udpsocket *udp;
+ adns_sockaddr udpaddr;
adns__consistency(ads,0,cc_entex);
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 (fd == ads->udpsocket) {
+ for (i=0; i<ads->nudpsockets; i++) {
+ udp= &ads->udpsockets[i];
+ if (fd != udp->fd) continue;
for (;;) {
udpaddrlen= sizeof(udpaddr);
- r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0,
- (struct sockaddr*)&udpaddr,&udpaddrlen);
+ r= recvfrom(fd,udpbuf,sizeof(udpbuf),0, &udpaddr.sa,&udpaddrlen);
if (r<0) {
if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; }
if (errno == EINTR) continue;
adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno));
r= 0; goto xit;
}
- if (udpaddrlen != sizeof(udpaddr)) {
- adns__diag(ads,-1,0,"datagram received with wrong address length %d"
- " (expected %d)", udpaddrlen,sizeof(udpaddr));
- continue;
- }
- if (udpaddr.sin_family != AF_INET) {
- adns__diag(ads,-1,0,"datagram received with wrong protocol family"
- " %u (expected %u)",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);
- continue;
- }
for (serv= 0;
serv < ads->nservers &&
- ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr;
+ !adns__sockaddrs_equal(&udpaddr.sa,
+ &ads->servers[serv].addr.sa);
serv++);
if (serv >= ads->nservers) {
adns__warn(ads,-1,0,"datagram received from unknown nameserver %s",
- inet_ntoa(udpaddr.sin_addr));
+ adns__sockaddr_ntoa(&udpaddr.sa, addrbuf));
continue;
}
adns__procdgram(ads,udpbuf,r,serv,0,*now);
}
+ break;
}
r= 0;
xit:
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
return r;
}
switch (ads->tcpstate) {
case server_disconnected:
+ case server_broken:
break;
case server_connecting:
if (fd != ads->tcpsocket) break;
assert(ads->tcprecv.used==0);
assert(ads->tcprecv_skip==0);
for (;;) {
+ /* This function can be called even if the fd wasn't actually
+ * flagged as writeable. For asynch tcp connect we have to
+ * actually use the writeability to tell us the connect has
+ * completed (or failed), so we need to double check. */
+ fd_set writeable;
+ struct timeval timeout = { 0,0 };
+ FD_ZERO(&writeable);
+ FD_SET(ads->tcpsocket,&writeable);
+ r= select(ads->tcpsocket+1,0,&writeable,0,&timeout);
+ if (r==0) break;
+ if (r<0) {
+ if (errno==EINTR) continue;
+ adns__tcp_broken(ads,"select","failed connecting writeability check");
+ r= 0; goto xit;
+ }
+ assert(FD_ISSET(ads->tcpsocket,&writeable));
if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; }
- r= read(ads->tcpsocket,&ads->tcprecv.buf,1);
+ r= read(ads->tcpsocket,ads->tcprecv.buf,1);
if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) {
tcp_connected(ads,*now);
r= 0; goto xit;
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();
}
r= 0;
xit:
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
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:
default:
abort();
}
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
return 0;
}
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) { inter_immed(tv_mod,tv_iobuf); 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);
*maxfd_io= maxfd;
xit:
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
}
void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds,
maxfd,readfds,writefds,exceptfds,
*now, 0);
xit:
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
}
/* General helpful functions. */
adns__tcp_broken(ads,0,0);
break;
case server_disconnected:
+ case server_broken:
break;
default:
abort();
}
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
}
int adns_processany(adns_state ads) {
* 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,
now,&r);
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
return 0;
}
void **context_r) {
int r, maxfd, rsel;
fd_set readfds, writefds, exceptfds;
- struct timeval *now, nowbuf, tvbuf, *tvp;
+ struct timeval tvbuf, *tvp;
adns__consistency(ads,*query_io,cc_entex);
for (;;) {
adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0);
}
}
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
return r;
}
if (!r) adns__autosys(ads,now);
r= adns__internal_check(ads,query_io,answer_r,context_r);
- adns__consistency(ads,0,cc_entex);
+ adns__returning(ads,0);
return r;
}
~ianmdlvl / adns.git / blobdiff