X-Git-Url: https://git.distorted.org.uk/~mdw/adns/blobdiff_plain/8402e34c7df0adad223cf1fa1328bb524a15d99f..a8768e80b11709ee11b70a769f0ea86964988e3b:/src/event.c diff --git a/src/event.c b/src/event.c index 3007a95..983e266 100644 --- a/src/event.c +++ b/src/event.c @@ -1,102 +1,310 @@ -/**/ +/* + * event.c + * - event loop core + * - TCP connection management + * - user-visible check/wait and event-loop-related functions + */ +/* + * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson + * + * 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) + * any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * 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. + */ -#include "adns-internal.h" +#include +#include +#include -static void autosys(adns_state ads, struct timeval now) { - if (ads->iflags & adns_if_noautosys) return; - adns_callback(ads,-1,0,0,0); -} +#include +#include -static int callb_checkfd(int maxfd, const fd_set *fds, int fd) { - return maxfd<0 || !fds ? 1 : - fdtcpstate == server_connecting || ads->tcpstate == server_ok); - warn("nameserver %s TCP connection lost: %s: %s", - inet_ntoa(ads->servers[tcpserver].addr,what,why)); + serv= ads->tcpserver; + adns__warn(ads,serv,0,"TCP connection lost: %s: %s",what,why); close(ads->tcpsocket); ads->tcpstate= server_disconnected; - serv= ads->tcpserver; - for (qu= ads->timew; qu; qu= nqu) { + for (qu= ads->timew.head; qu; qu= nqu) { nqu= qu->next; - if (qu->senttcpserver == -1) continue; - assert(qu->senttcpserver == serv); - DLIST_UNLINK(ads->timew,qu); - adns__query_fail(ads,qu,adns_s_connlost); /* wishlist: send to other servers ? */ + if (qu->state == query_udp) continue; + assert(qu->state == query_tcpwait || qu->state == query_tcpsent); + qu->state= query_tcpwait; + qu->tcpfailed |= (1<tcpfailed == (1<nservers)-1) { + LIST_UNLINK(ads->timew,qu); + adns__query_fail(qu,adns_s_allservfail); + } } - ads->tcpbuf.used= 0; + ads->tcprecv.used= ads->tcpsend.used= 0; ads->tcpserver= (serv+1)%ads->nservers; } -void adns__tcp_tryconnect(adns_state ads) { +static void tcp_connected(adns_state ads, struct timeval now) { + adns_query qu, nqu; + + adns__debug(ads,ads->tcpserver,0,"TCP connected"); + ads->tcpstate= server_ok; + for (qu= ads->timew.head; qu; qu= nqu) { + nqu= qu->next; + if (qu->state == query_udp) continue; + assert (qu->state == query_tcpwait); + adns__query_tcp(qu,now); + } +} + +void adns__tcp_tryconnect(adns_state ads, struct timeval now) { int r, fd, tries; - sockaddr_in addr; + struct sockaddr_in addr; + struct protoent *proto; for (tries=0; triesnservers; tries++) { if (ads->tcpstate == server_connecting || ads->tcpstate == server_ok) return; assert(ads->tcpstate == server_disconnected); - assert(!ads->tcpbuf.used); + assert(!ads->tcpsend.used); + assert(!ads->tcprecv.used); proto= getprotobyname("tcp"); - if (!proto) { diag(ads,"unable to find protocol number for TCP !",-1); return; } + 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 (fd<0) { diag(ads,"cannot create TCP socket: %s",-1,strerror(errno)); return; } - if (!adns__setnonblock(fd)) return; + 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)); + close(fd); + return; + } memset(&addr,0,sizeof(addr)); addr.sin_family= AF_INET; - addr.sin_port= htons(NSPORT); + addr.sin_port= htons(DNS_PORT); addr.sin_addr= ads->servers[ads->tcpserver].addr; r= connect(fd,&addr,sizeof(addr)); ads->tcpsocket= fd; ads->tcpstate= server_connecting; - if (r==0) { ads->tcpstate= server_ok; return; } + if (r==0) { tcp_connected(ads,now); continue; } if (errno == EWOULDBLOCK || errno == EINPROGRESS) return; - tcpserver_broken(ads,"connect",strerror(errno)); + adns__tcp_broken(ads,"connect",strerror(errno)); } } -int adns_callback(adns_state ads, int maxfd, - const fd_set *readfds, const fd_set *writefds, - const fd_set *exceptfds) { - int skip, dgramlen, count, udpaddrlen; - enum adns__tcpstate oldtcpstate; - unsigned char udpbuf[UDPMAXDGRAM]; - struct sockaddr_in udpaddr; +/* `Interest' functions - find out which fd's we might be interested in, + * and when we want to be called back for a timeout. + */ + +static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, + struct timeval maxto) { + struct timeval *rbuf; + + if (!tv_io) return; + rbuf= *tv_io; + if (!rbuf) { + *tvbuf= maxto; *tv_io= tvbuf; + } else { + if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; + } +/*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", + maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ +} + +static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, + struct timeval now, struct timeval maxtime) { + ldiv_t dr; + +/*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", + now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ + if (!tv_io) return; + maxtime.tv_sec -= (now.tv_sec+2); + maxtime.tv_usec -= (now.tv_usec-2000000); + dr= ldiv(maxtime.tv_usec,1000000); + maxtime.tv_sec += dr.quot; + maxtime.tv_usec -= dr.quot*1000000; + if (maxtime.tv_sec<0) timerclear(&maxtime); + inter_maxto(tv_io,tvbuf,maxtime); +} + +static void inter_addfd(int *maxfd, fd_set *fds, int fd) { + if (!maxfd || !fds) return; + if (fd>=*maxfd) *maxfd= fd+1; + FD_SET(fd,fds); +} + +static void checktimeouts(adns_state ads, struct timeval now, + struct timeval **tv_io, struct timeval *tvbuf) { + adns_query qu, nqu; + + for (qu= ads->timew.head; qu; qu= nqu) { + nqu= qu->next; + if (timercmp(&now,&qu->timeout,>)) { + LIST_UNLINK(ads->timew,qu); + if (qu->state != query_udp) { + adns__query_fail(qu,adns_s_timeout); + } else { + adns__query_udp(qu,now); + } + } else { + inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); + } + } +} + +static void checkfds(adns_state ads, int *maxfd, + fd_set *readfds, fd_set *writefds, fd_set *exceptfds, + int avail, struct pollfd *buf, int *count_r) { + int count; count= 0; - oldtcpstate= ads->tcpstate; + inter_addfd(ads->udpsocket,maxfd,readfds); + poll_addfd(ads->udpsocket,avail,buf,&count,POLLIN); + + switch (ads->tcpstate) { + case server_disconnected: + break; + case server_connecting: + inter_addfd(ads->tcpsocket,maxfd,writefds); + poll_addfd(ads->tcpsocket,avail,buf,&count,POLLOUT); + break; + case server_ok: + inter_addfd(ads->tcpsocket,maxfd,readfds); + inter_addfd(ads->tcpsocket,maxfd,exceptfds); + if (ads->tcpsend.used) inter_addfd(ads->tcpsocket,maxfd,writefds); + poll_addfd(ads->tcpsocket,avail,buf,&count, + ads->tcpsend.used ? POLLIN|POLLOUT : POLLIN); + break; + default: + abort(); + } +} + +struct pollfd *adns_pollfds(adns_state ads, struct pollfd *buf, + int *len_io, int *timeout_io) { + struct timeval now, tvbuf, *tvp; + int timeout; + + r= gettimeofday(&now,0); + if (r) return 0; + + timeout= *timeout_io; + if (timeout < 0) { + tvtop= 0; + } else { + tvbuf.tv_sec= now.tv_sec + (timeout/1000); + tvbuf.tv_usec= now.tv_usec + (timeout%1000)*1000; + if (tvbuf.tv_sec >= 1000000) { + tvbuf.tv_sec += 1; + tvbuf.tv_usec -= 1000000; + } + tvp= &tvbuf; + } + checktimouts(ads,now,&tvp,&tvbuf); + + if (tvp) { + assert(tvbuf.tv_sectv_sec - now.tv_sec)*1000 + (tvp->tv_usec - now.tv_usec)/1000; + } else { + *timeout_io= -1; + } + + avail= *len_io; + if (avail == -1) { + buf= ads->pollfdsbuf; + avail= 2; + if (!buf) { + buf= ads->pollfdsbuf= malloc(sizeof(struct pollfd)*avail); + if (!buf) return 0; + } + } + checkfds(ads, 0,0,0,0, avail,buf,len_io); + if (*len_io > avail) { errno= ENOSPC; return 0; } + + return buf; +} + +void adns_interest(adns_state ads, int *maxfd, + fd_set *readfds, fd_set *writefds, fd_set *exceptfds, + struct timeval **tv_io, struct timeval *tvbuf) { + struct timeval now; + struct timeval tvto_lr; + int r; - if (ads->tcpstate == server_connecting) { +/*fprintf(stderr,"adns_interest\n");*/ + + r= gettimeofday(&now,0); + if (r) { + adns__warn(ads,-1,0,"gettimeofday failed - will sleep for a bit: %s", + strerror(errno)); + timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS); + inter_maxto(tv_io, tvbuf, tvto_lr); + } else { + checktimeouts(ads,now,tv_io,tvbuf); + } + + checkfds(ads, maxfd,readfds,writefds,exceptfds, 0,0,0); +} + +/* Callback procedures - these do the real work of reception and timeout, etc. */ + +static int callb_checkfd(int maxfd, const fd_set *fds, int fd) { + return maxfd<0 || !fds ? 1 : + fdtcpstate) { + case server_disconnected: + break; + case server_connecting: if (callb_checkfd(maxfd,writefds,ads->tcpsocket)) { count++; assert(ads->tcprecv.used==0); - vbuf_ensure(&ads->tcprecv,1); + if (!adns__vbuf_ensure(&ads->tcprecv,1)) return -1; if (ads->tcprecv.buf) { r= read(ads->tcpsocket,&ads->tcprecv.buf,1); if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { - debug("nameserver %s TCP connected", - inet_ntoa(ads->servers[ads->tcpserver].addr)); - ads->tcpstate= server_connected; + tcp_connected(ads,now); } else if (r>0) { - tcpserver_broken(ads,"connect/read","sent data before first request"); + adns__tcp_broken(ads,"connect/read","sent data before first request"); } else if (errno!=EINTR) { - tcpserver_broken(ads,"connect/read",strerror(errno)); + adns__tcp_broken(ads,"connect/read",strerror(errno)); } } } - } - if (ads->tcpstate == server_connected) { - if (oldtcpstate == server_connected) - count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) + - callb_checkfd(maxfd,exceptfds,ads->tcpsocket) + - (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)); - if (oldtcpstate != server_connected || callb_checkfd(maxfd,readfds,ads->tcpsocket)) { + break; + case server_ok: + count+= callb_checkfd(maxfd,readfds,ads->tcpsocket) + + callb_checkfd(maxfd,exceptfds,ads->tcpsocket) + + (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)); + if (callb_checkfd(maxfd,readfds,ads->tcpsocket)) { skip= 0; for (;;) { if (ads->tcprecv.usedtcprecv.usedtcprecv.buf+skip+2,dgramlen,ads->tcpserver); + adns__procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,ads->tcpserver,now); skip+= 2+dgramlen; continue; } } ads->tcprecv.used -= skip; memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used); - vbuf_ensure(&ads->tcprecv,want); - if (ads->tcprecv.used >= ads->tcprecv.avail) break; + skip= 0; + if (!adns__vbuf_ensure(&ads->tcprecv,want)) return -1; + assert(ads->tcprecv.used <= ads->tcprecv.avail); + if (ads->tcprecv.used == ads->tcprecv.avail) continue; r= read(ads->tcpsocket, ads->tcprecv.buf+ads->tcprecv.used, ads->tcprecv.avail-ads->tcprecv.used); @@ -124,23 +334,26 @@ int adns_callback(adns_state ads, int maxfd, if (errno==EAGAIN || errno==EWOULDBLOCK || errno==ENOMEM) break; if (errno==EINTR) continue; } - tcpserver_broken(ads->tcpserver,"read",r?strerror(errno):"closed"); + adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); break; } } } else if (callb_checkfd(maxfd,exceptfds,ads->tcpsocket)) { - tcpserver_broken(ads->tcpserver,"select","exceptional condition detected"); + adns__tcp_broken(ads,"select","exceptional condition detected"); } else if (ads->tcpsend.used && callb_checkfd(maxfd,writefds,ads->tcpsocket)) { r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); if (r<0) { if (errno!=EAGAIN && errno!=EWOULDBLOCK && errno!=ENOMEM && errno!=EINTR) { - tcpserver_broken(ads->tcpserver,"write",strerror(errno)); + adns__tcp_broken(ads,"write",strerror(errno)); } } else if (r>0) { ads->tcpsend.used -= r; memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); } } + break; + default: + abort(); } if (callb_checkfd(maxfd,readfds,ads->udpsocket)) { @@ -151,22 +364,22 @@ int adns_callback(adns_state ads, int maxfd, if (r<0) { if (!(errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR || errno == ENOMEM || errno == ENOBUFS)) - warn("datagram receive error: %s",strerror(errno)); + adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); break; } if (udpaddrlen != sizeof(udpaddr)) { - diag("datagram received with wrong address length %d (expected %d)", - 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) { - diag("datagram received with wrong protocol family %u (expected %u)", - 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) != NSPORT) { - diag("datagram received from wrong port %u (expected %u)", - ntohs(udpaddr.sin_port),NSPORT); + 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; @@ -174,94 +387,32 @@ int adns_callback(adns_state ads, int maxfd, ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; serv++); if (serv >= ads->nservers) { - warn("datagram received from unknown nameserver %s",inet_ntoa(udpaddr.sin_addr)); + adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", + inet_ntoa(udpaddr.sin_addr)); continue; } - procdgram(ads,udpbuf,r,serv); + adns__procdgram(ads,udpbuf,r,serv,now); } } + return count; } -static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, - struct timeval maxto) { - struct timeval rbuf; - - rbuf= *tv_io; - if (!rbuf) { *tvbuf= maxto; *tv_io= tvbuf; return; } - if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; -} - -static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, - struct timeval now, struct timeval maxtime) { - ldiv_t dr; - - maxtime.tv_sec -= (now.tv_sec-1); - maxtime.tv_usec += (1000-now.tv_usec); - dr= ldiv(maxtime.tv_usec,1000); - maxtime.tv_sec += dr.quot; - maxtime.tv_usec -= dr.rem; - inter_maxto(tv_io,tvbuf,maxtime); -} - -static void localresourcerr(struct timeval **tv_io, struct timeval *tvbuf, - const char *syscall) { - struct timeval tvto_lr; - - warn(ads,"local system resources scarce (during %s): %s",syscall,strerror(errno)); - timerclear(&tvto_lr); timevaladd(&tvto_lr,LOCALRESOURCEMS); - inter_maxto(tv_io, tvbuf, tvto_lr); - return; -} - -static void inter_addfd(int *maxfd, fd_set *fds, int fd) { - if (fd>=*maxfd) *maxfd= fd+1; - FD_SET(fd,fds); -} - -void adns_interest(adns_state ads, int *maxfd, - fd_set *readfds, fd_set *writefds, fd_set *exceptfds, - struct timeval **tv_io, struct timeval *tvbuf) { +int adns_callback(adns_state ads, int maxfd, + const fd_set *readfds, const fd_set *writefds, + const fd_set *exceptfds) { struct timeval now; - adns_query qu; int r; - - r= gettimeofday(&now,0); - if (r) { localresourcerr(tv_io,tvbuf,"gettimeofday"); return; } - for (qu= ads->timew; qu; qu= nqu) { - nqu= qu->next; - if (timercmp(&now,qu->timeout,>)) { - DLIST_UNLINK(ads->timew,qu); - if (qu->nextudpserver == -1) { - query_fail(ads,qu,adns_s_notresponding); - } else { - DLIST_LINKTAIL(ads->tosend,qu); - } - } else { - inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); - } - } - - for (qu= ads->tosend; qu; qu= nqu) { - nqu= qu->next; - quproc_tosend(ads,qu,now); - } + r= gettimeofday(&now,0); if (r) return -1; + checktimeouts(ads,now,0,0); + return internal_callback(ads,maxfd,readfds,writefds,exceptfds,now); +} - inter_addfd(maxfd,readfds,ads->udpsocket); +/* User-visible functions and their implementation. */ - switch (ads->tcpstate) { - case server_disc: - break; - case server_connecting: - inter_addfd(maxfd,writefds,ads->tcpsocket); - break; - case server_connected: - inter_addfd(maxfd,readfds,ads->tcpsocket); - inter_addfd(maxfd,exceptfds,ads->tcpsocket); - if (ads->opbufused) inter_addfd(maxfd,writefds,ads->tcpsocket); - default: - abort(); - } +void adns__autosys(adns_state ads, struct timeval now) { + if (ads->iflags & adns_if_noautosys) return; + adns_callback(ads,-1,0,0,0); } static int internal_check(adns_state ads, @@ -279,7 +430,7 @@ static int internal_check(adns_state ads, } LIST_UNLINK(ads->output,qu); *answer= qu->answer; - if (context_r) *context_r= qu->context; + if (context_r) *context_r= qu->ctx.ext; free(qu); return 0; } @@ -294,12 +445,15 @@ int adns_wait(adns_state ads, for (;;) { r= internal_check(ads,query_io,answer_r,context_r); - if (r && r != EWOULDBLOCK) return r; + if (r != EWOULDBLOCK) return r; maxfd= 0; tvp= 0; FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); adns_interest(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf); rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); - if (rsel==-1) return r; + if (rsel==-1) { + if (errno == EINTR && !(ads->iflags & adns_if_eintr)) continue; + return errno; + } rcb= adns_callback(ads,maxfd,&readfds,&writefds,&exceptfds); assert(rcb==rsel); } @@ -309,6 +463,10 @@ int adns_check(adns_state ads, adns_query *query_io, adns_answer **answer_r, void **context_r) { - autosys(ads); + struct timeval now; + int r; + + r= gettimeofday(&now,0); if (r) return errno; + adns__autosys(ads,now); return internal_check(ads,query_io,answer_r,context_r); }