X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fevent.c;h=c326c2809714d5313ef6844912cf11ed2e9b6f1e;hb=5d3224e9de99d596dc8d973a75266afc603a46cd;hp=1b679e60760bff8bdf2c5b5e5b85f8c8a795db09;hpb=26cc07a3b9ee74da8d50289482bfc3e7a34352e9;p=adns.git diff --git a/src/event.c b/src/event.c index 1b679e6..c326c28 100644 --- a/src/event.c +++ b/src/event.c @@ -5,16 +5,16 @@ * - user-visible check/wait and event-loop-related functions */ /* - * This file is - * Copyright (C) 1997-1999 Ian Jackson - * - * It is part of adns, which is - * Copyright (C) 1997-1999 Ian Jackson - * Copyright (C) 1999 Tony Finch + * This file is part of adns, which is + * Copyright (C) 1997-2000,2003,2006,2014-2016,2020 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, @@ -23,8 +23,7 @@ * 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 @@ -37,6 +36,7 @@ #include #include #include +#include #include "internal.h" #include "tvarith.h" @@ -44,9 +44,6 @@ /* 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; @@ -54,11 +51,18 @@ static void tcp_close(adns_state ads) { 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; @@ -76,9 +80,24 @@ static void tcp_connected(adns_state ads, struct timeval 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; + 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; triesnservers; tries++) { @@ -98,23 +117,24 @@ void adns__tcp_tryconnect(adns_state ads, struct timeval now) { 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; } @@ -124,12 +144,25 @@ void adns__tcp_tryconnect(adns_state ads, struct timeval now) { return; } adns__tcp_broken(ads,"connect",strerror(errno)); - ads->tcpstate= server_disconnected; + tcp_broken_events(ads); } } /* Timeout handling functions. */ +int adns__gettimeofday(adns_state ads, struct timeval *tv) { + if (!(ads->iflags & adns_if_monotonic)) + return gettimeofday(tv,0); + + struct timespec ts; + int r = clock_gettime(CLOCK_MONOTONIC,&ts); + if (r) return r; + + tv->tv_sec = ts.tv_sec; + tv->tv_usec = ts.tv_nsec / 1000; + return 0; +} + void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, struct timeval *tv_buf) { const struct timeval *now; @@ -137,8 +170,9 @@ void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, now= *now_io; if (now) return; - r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } - adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); + r= adns__gettimeofday(ads,tv_buf); if (!r) { *now_io= tv_buf; return; } + adns__diag(ads,-1,0,"gettimeofday/clock_gettime failed: %s", + strerror(errno)); adns_globalsystemfailure(ads); return; } @@ -190,11 +224,16 @@ 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; + struct timeval expires; for (qu= queue->head; qu; qu= nqu) { nqu= qu->next; - if (!timercmp(&now,&qu->timeout,>)) { - inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); + if (timercmp(&now,&qu->timeout_started,<)) /* clock rewound */ + qu->timeout_started= now; + expires= qu->timeout_started; + timevaladd(&expires, qu->timeout_ms); + if (!timercmp(&now,&expires,>)) { + inter_maxtoabs(tv_io,tvbuf,now,expires); } else { if (!act) { inter_immed(tv_io,tvbuf); return; } LIST_UNLINK(*queue,qu); @@ -211,21 +250,11 @@ static void timeouts_queue(adns_state ads, int act, 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; } @@ -275,18 +304,18 @@ void adns__timeouts(adns_state ads, int act, void adns_firsttimeout(adns_state ads, struct timeval **tv_io, struct timeval *tvbuf, struct timeval now) { - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); 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) { struct timeval tv_buf; - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); 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 @@ -295,44 +324,59 @@ void adns_processtimeouts(adns_state ads, const struct timeval *now) { 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) + + int i; - assert(MAX_POLLFDS==2); + assert(MAX_POLLFDS == MAXUDP + 1); - pollfds_buf[0].fd= ads->udpsocket; - pollfds_buf[0].events= POLLIN; - pollfds_buf[0].revents= 0; + for (i=0; inudpsockets; 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); + adns__consistency(ads,0,cc_enter); 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]); @@ -349,7 +393,8 @@ int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { 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); @@ -366,17 +411,18 @@ int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { 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; inudpsockets; 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; @@ -384,54 +430,58 @@ int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { 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; } int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { int r; - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); 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; @@ -446,8 +496,8 @@ int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { 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); @@ -458,23 +508,28 @@ int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { adns__tcp_broken(ads,"write",strerror(errno)); r= 0; goto xit; } else if (r>0) { + assert(r <= ads->tcpsend.used); 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) { - adns__consistency(ads,0,cc_entex); +int adns_processexceptional(adns_state ads, int fd, + const struct timeval *now) { + adns__consistency(ads,0,cc_enter); switch (ads->tcpstate) { case server_disconnected: + case server_broken: break; case server_connecting: case server_ok: @@ -484,14 +539,15 @@ int adns_processexceptional(adns_state ads, int fd, const struct timeval *now) { 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; @@ -502,7 +558,8 @@ static void fd_event(adns_state ads, int fd, 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); } } @@ -519,9 +576,12 @@ void adns__fdevents(adns_state 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 } } @@ -535,13 +595,13 @@ void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, struct pollfd pollfds[MAX_POLLFDS]; int i, fd, maxfd, npollfds; - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); 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_tobuf); goto xit; } - adns__timeouts(ads, 1, tv_mod,tv_tobuf, *now); + adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now); } npollfds= adns__pollfds(ads,pollfds); @@ -556,7 +616,7 @@ void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, *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, @@ -566,7 +626,7 @@ void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, struct pollfd pollfds[MAX_POLLFDS]; int npollfds, i; - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); adns__must_gettimeofday(ads,&now,&tv_buf); if (!now) goto xit; adns_processtimeouts(ads,now); @@ -578,16 +638,30 @@ 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. */ void adns_globalsystemfailure(adns_state ads) { - adns__consistency(ads,0,cc_entex); + /* Must not be called by adns during actual processing of a + * particular query, since it reenters adns. Only safe to call in + * situations where it would be safe to call adns_returning. */ + adns__consistency(ads,0,cc_enter); - 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); + for (;;) { + adns_query qu; +#define GSF_QQ(QQ) \ + if ((qu= ads->QQ.head)) { \ + LIST_UNLINK(ads->QQ,qu); \ + adns__query_fail(qu, adns_s_systemfail); \ + continue; \ + } + GSF_QQ(udpw); + GSF_QQ(tcpw); +#undef GSF_QQ + break; + } switch (ads->tcpstate) { case server_connecting: @@ -595,11 +669,12 @@ void adns_globalsystemfailure(adns_state ads) { 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) { @@ -608,9 +683,9 @@ int adns_processany(adns_state ads) { struct pollfd pollfds[MAX_POLLFDS]; int npollfds; - adns__consistency(ads,0,cc_entex); + adns__consistency(ads,0,cc_enter); - r= gettimeofday(&now,0); + r= adns__gettimeofday(ads,&now); if (!r) adns_processtimeouts(ads,&now); /* We just use adns__fdevents to loop over the fd's trying them. @@ -618,13 +693,13 @@ 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