e576be50 |
1 | /* |
2 | * event.c |
3 | * - event loop core |
4 | * - TCP connection management |
5 | * - user-visible check/wait and event-loop-related functions |
6 | */ |
7 | /* |
a719a4be |
8 | * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson |
e576be50 |
9 | * |
10 | * This program is free software; you can redistribute it and/or modify |
11 | * it under the terms of the GNU General Public License as published by |
12 | * the Free Software Foundation; either version 2, or (at your option) |
13 | * any later version. |
14 | * |
15 | * This program is distributed in the hope that it will be useful, |
16 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
17 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
18 | * GNU General Public License for more details. |
19 | * |
20 | * You should have received a copy of the GNU General Public License |
21 | * along with this program; if not, write to the Free Software Foundation, |
22 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
23 | */ |
656b2da9 |
24 | |
4353a5c4 |
25 | #include <errno.h> |
26 | #include <stdlib.h> |
0f091044 |
27 | #include <unistd.h> |
4353a5c4 |
28 | |
0f091044 |
29 | #include <sys/types.h> |
30 | #include <sys/time.h> |
4353a5c4 |
31 | #include <netdb.h> |
eec1d9c8 |
32 | #include <sys/socket.h> |
33 | #include <netinet/in.h> |
4353a5c4 |
34 | #include <arpa/inet.h> |
35 | |
36 | #include "internal.h" |
37e28fde |
37 | |
620c146d |
38 | /* TCP connection management. */ |
39 | |
40 | void adns__tcp_closenext(adns_state ads) { |
41 | int serv; |
42 | |
43 | serv= ads->tcpserver; |
44 | close(ads->tcpsocket); |
45 | ads->tcpstate= server_disconnected; |
46 | ads->tcprecv.used= ads->tcpsend.used= 0; |
47 | ads->tcpserver= (serv+1)%ads->nservers; |
48 | } |
656b2da9 |
49 | |
8402e34c |
50 | void adns__tcp_broken(adns_state ads, const char *what, const char *why) { |
51 | int serv; |
4353a5c4 |
52 | adns_query qu, nqu; |
8402e34c |
53 | |
54 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); |
ddfda861 |
55 | serv= ads->tcpserver; |
68442019 |
56 | adns__warn(ads,serv,0,"TCP connection lost: %s: %s",what,why); |
620c146d |
57 | adns__tcp_closenext(ads); |
37e28fde |
58 | |
4353a5c4 |
59 | for (qu= ads->timew.head; qu; qu= nqu) { |
8402e34c |
60 | nqu= qu->next; |
d8c062fa |
61 | if (qu->state == query_tosend) continue; |
ddfda861 |
62 | assert(qu->state == query_tcpwait || qu->state == query_tcpsent); |
63 | qu->state= query_tcpwait; |
64 | qu->tcpfailed |= (1<<serv); |
65 | if (qu->tcpfailed == (1<<ads->nservers)-1) { |
4353a5c4 |
66 | LIST_UNLINK(ads->timew,qu); |
3955725c |
67 | adns__query_fail(qu,adns_s_allservfail); |
ddfda861 |
68 | } |
8402e34c |
69 | } |
8402e34c |
70 | } |
71 | |
ddfda861 |
72 | static void tcp_connected(adns_state ads, struct timeval now) { |
4353a5c4 |
73 | adns_query qu, nqu; |
74 | |
68442019 |
75 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
4353a5c4 |
76 | ads->tcpstate= server_ok; |
ddfda861 |
77 | for (qu= ads->timew.head; qu; qu= nqu) { |
78 | nqu= qu->next; |
d8c062fa |
79 | if (qu->state == query_tosend) continue; |
ddfda861 |
80 | assert (qu->state == query_tcpwait); |
3955725c |
81 | adns__query_tcp(qu,now); |
ddfda861 |
82 | } |
83 | } |
84 | |
85 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
8402e34c |
86 | int r, fd, tries; |
4353a5c4 |
87 | struct sockaddr_in addr; |
88 | struct protoent *proto; |
8402e34c |
89 | |
90 | for (tries=0; tries<ads->nservers; tries++) { |
91 | if (ads->tcpstate == server_connecting || ads->tcpstate == server_ok) return; |
92 | assert(ads->tcpstate == server_disconnected); |
4353a5c4 |
93 | assert(!ads->tcpsend.used); |
94 | assert(!ads->tcprecv.used); |
8402e34c |
95 | |
96 | proto= getprotobyname("tcp"); |
68442019 |
97 | if (!proto) { adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); return; } |
8402e34c |
98 | fd= socket(AF_INET,SOCK_STREAM,proto->p_proto); |
4353a5c4 |
99 | if (fd<0) { |
68442019 |
100 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
4353a5c4 |
101 | return; |
102 | } |
103 | r= adns__setnonblock(ads,fd); |
104 | if (r) { |
68442019 |
105 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking: %s",strerror(r)); |
4353a5c4 |
106 | close(fd); |
107 | return; |
108 | } |
8402e34c |
109 | memset(&addr,0,sizeof(addr)); |
110 | addr.sin_family= AF_INET; |
98a3f706 |
111 | addr.sin_port= htons(DNS_PORT); |
8402e34c |
112 | addr.sin_addr= ads->servers[ads->tcpserver].addr; |
eec1d9c8 |
113 | r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr)); |
8402e34c |
114 | ads->tcpsocket= fd; |
115 | ads->tcpstate= server_connecting; |
4353a5c4 |
116 | if (r==0) { tcp_connected(ads,now); continue; } |
8402e34c |
117 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) return; |
ddfda861 |
118 | adns__tcp_broken(ads,"connect",strerror(errno)); |
8402e34c |
119 | } |
120 | } |
121 | |
620c146d |
122 | /* Timeout handling functions. */ |
123 | |
124 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
125 | struct timeval *tv_buf) { |
126 | const struct timeval *now; |
127 | int r; |
128 | |
129 | now= *now_io; |
130 | if (now) return; |
131 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } |
132 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); |
133 | adns_globalsystemfailure(ads); |
134 | return; |
135 | } |
4353a5c4 |
136 | |
137 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
138 | struct timeval maxto) { |
139 | struct timeval *rbuf; |
140 | |
141 | if (!tv_io) return; |
142 | rbuf= *tv_io; |
94436798 |
143 | if (!rbuf) { |
144 | *tvbuf= maxto; *tv_io= tvbuf; |
145 | } else { |
146 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
147 | } |
ffbda80c |
148 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
149 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ |
4353a5c4 |
150 | } |
151 | |
152 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
153 | struct timeval now, struct timeval maxtime) { |
154 | ldiv_t dr; |
155 | |
ffbda80c |
156 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
157 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ |
4353a5c4 |
158 | if (!tv_io) return; |
94436798 |
159 | maxtime.tv_sec -= (now.tv_sec+2); |
160 | maxtime.tv_usec -= (now.tv_usec-2000000); |
161 | dr= ldiv(maxtime.tv_usec,1000000); |
4353a5c4 |
162 | maxtime.tv_sec += dr.quot; |
94436798 |
163 | maxtime.tv_usec -= dr.quot*1000000; |
164 | if (maxtime.tv_sec<0) timerclear(&maxtime); |
4353a5c4 |
165 | inter_maxto(tv_io,tvbuf,maxtime); |
166 | } |
167 | |
620c146d |
168 | void adns__timeouts(adns_state ads, int act, |
169 | struct timeval **tv_io, struct timeval *tvbuf, |
170 | struct timeval now) { |
4353a5c4 |
171 | adns_query qu, nqu; |
620c146d |
172 | |
4353a5c4 |
173 | for (qu= ads->timew.head; qu; qu= nqu) { |
174 | nqu= qu->next; |
d855b532 |
175 | if (!timercmp(&now,&qu->timeout,>)) { |
620c146d |
176 | if (!tv_io) continue; |
177 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
178 | } else { |
179 | if (!act) continue; |
4353a5c4 |
180 | LIST_UNLINK(ads->timew,qu); |
d8c062fa |
181 | if (qu->state != query_tosend) { |
3955725c |
182 | adns__query_fail(qu,adns_s_timeout); |
4353a5c4 |
183 | } else { |
d8c062fa |
184 | adns__query_send(qu,now); |
4353a5c4 |
185 | } |
620c146d |
186 | nqu= ads->timew.head; |
4353a5c4 |
187 | } |
188 | } |
189 | } |
94436798 |
190 | |
620c146d |
191 | void adns_firsttimeout(adns_state ads, |
192 | struct timeval **tv_io, struct timeval *tvbuf, |
193 | struct timeval now) { |
194 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
195 | } |
196 | |
197 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { |
198 | struct timeval tv_buf; |
199 | |
200 | adns__must_gettimeofday(ads,&now,&tv_buf); if (!now) return; |
201 | adns__timeouts(ads, 1, 0,0, *now); |
a8768e80 |
202 | } |
203 | |
620c146d |
204 | /* fd handling functions. These are the top-level of the real work of |
205 | * reception and often transmission. |
206 | */ |
207 | |
208 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { |
209 | /* Returns the number of entries filled in. Always zeroes revents. */ |
210 | |
211 | assert(MAX_POLLFDS==2); |
a8768e80 |
212 | |
620c146d |
213 | pollfds_buf[0].fd= ads->udpsocket; |
214 | pollfds_buf[0].events= POLLIN; |
215 | pollfds_buf[0].revents= 0; |
4353a5c4 |
216 | |
217 | switch (ads->tcpstate) { |
218 | case server_disconnected: |
620c146d |
219 | return 1; |
4353a5c4 |
220 | case server_connecting: |
620c146d |
221 | pollfds_buf[1].events= POLLOUT; |
4353a5c4 |
222 | break; |
223 | case server_ok: |
620c146d |
224 | pollfds_buf[1].events= ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI; |
e062dcae |
225 | break; |
4353a5c4 |
226 | default: |
227 | abort(); |
228 | } |
620c146d |
229 | pollfds_buf[1].fd= ads->tcpsocket; |
620c146d |
230 | return 2; |
4353a5c4 |
231 | } |
232 | |
620c146d |
233 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
234 | int skip, want, dgramlen, r, udpaddrlen, serv; |
98a3f706 |
235 | byte udpbuf[DNS_MAXUDP]; |
37e28fde |
236 | struct sockaddr_in udpaddr; |
620c146d |
237 | |
ddfda861 |
238 | switch (ads->tcpstate) { |
239 | case server_disconnected: |
ddfda861 |
240 | case server_connecting: |
ddfda861 |
241 | break; |
242 | case server_ok: |
620c146d |
243 | if (fd != ads->tcpsocket) break; |
244 | skip= 0; |
245 | for (;;) { |
246 | if (ads->tcprecv.used<skip+2) { |
247 | want= 2; |
248 | } else { |
249 | dgramlen= (ads->tcprecv.buf[skip]<<8) | ads->tcprecv.buf[skip+1]; |
250 | if (ads->tcprecv.used<skip+2+dgramlen) { |
251 | want= 2+dgramlen; |
656b2da9 |
252 | } else { |
ebf4877a |
253 | adns__procdgram(ads,ads->tcprecv.buf+skip+2,dgramlen,ads->tcpserver,1,*now); |
620c146d |
254 | skip+= 2+dgramlen; continue; |
656b2da9 |
255 | } |
256 | } |
620c146d |
257 | ads->tcprecv.used -= skip; |
258 | memmove(ads->tcprecv.buf,ads->tcprecv.buf+skip,ads->tcprecv.used); |
259 | skip= 0; |
260 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) return ENOMEM; |
261 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
262 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; |
263 | r= read(ads->tcpsocket, |
264 | ads->tcprecv.buf+ads->tcprecv.used, |
265 | ads->tcprecv.avail-ads->tcprecv.used); |
266 | if (r>0) { |
267 | ads->tcprecv.used+= r; |
268 | } else { |
269 | if (r) { |
270 | if (errno==EAGAIN || errno==EWOULDBLOCK) return 0; |
271 | if (errno==EINTR) continue; |
272 | if (errno_resources(errno)) return errno; |
656b2da9 |
273 | } |
620c146d |
274 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
275 | return 0; |
656b2da9 |
276 | } |
620c146d |
277 | } /* never reached */ |
ddfda861 |
278 | default: |
279 | abort(); |
656b2da9 |
280 | } |
620c146d |
281 | if (fd == ads->udpsocket) { |
37e28fde |
282 | for (;;) { |
283 | udpaddrlen= sizeof(udpaddr); |
eec1d9c8 |
284 | r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0, |
285 | (struct sockaddr*)&udpaddr,&udpaddrlen); |
37e28fde |
286 | if (r<0) { |
620c146d |
287 | if (errno == EAGAIN || errno == EWOULDBLOCK) return 0; |
288 | if (errno == EINTR) continue; |
289 | if (errno_resources(errno)) return errno; |
290 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); |
291 | return 0; |
37e28fde |
292 | } |
293 | if (udpaddrlen != sizeof(udpaddr)) { |
68442019 |
294 | adns__diag(ads,-1,0,"datagram received with wrong address length %d" |
295 | " (expected %d)", udpaddrlen,sizeof(udpaddr)); |
37e28fde |
296 | continue; |
297 | } |
298 | if (udpaddr.sin_family != AF_INET) { |
68442019 |
299 | adns__diag(ads,-1,0,"datagram received with wrong protocol family" |
4353a5c4 |
300 | " %u (expected %u)",udpaddr.sin_family,AF_INET); |
37e28fde |
301 | continue; |
302 | } |
98a3f706 |
303 | if (ntohs(udpaddr.sin_port) != DNS_PORT) { |
68442019 |
304 | adns__diag(ads,-1,0,"datagram received from wrong port %u (expected %u)", |
98a3f706 |
305 | ntohs(udpaddr.sin_port),DNS_PORT); |
37e28fde |
306 | continue; |
307 | } |
308 | for (serv= 0; |
309 | serv < ads->nservers && |
310 | ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; |
311 | serv++); |
312 | if (serv >= ads->nservers) { |
68442019 |
313 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", |
4353a5c4 |
314 | inet_ntoa(udpaddr.sin_addr)); |
37e28fde |
315 | continue; |
316 | } |
ebf4877a |
317 | adns__procdgram(ads,udpbuf,r,serv,0,*now); |
656b2da9 |
318 | } |
37e28fde |
319 | } |
620c146d |
320 | return 0; |
656b2da9 |
321 | } |
656b2da9 |
322 | |
620c146d |
323 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
656b2da9 |
324 | int r; |
620c146d |
325 | |
326 | switch (ads->tcpstate) { |
327 | case server_disconnected: |
328 | break; |
329 | case server_connecting: |
330 | if (fd != ads->tcpsocket) break; |
331 | assert(ads->tcprecv.used==0); |
332 | for (;;) { |
333 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) return ENOMEM; |
334 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
335 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
336 | tcp_connected(ads,*now); |
337 | return 0; |
338 | } |
339 | if (r>0) { |
340 | adns__tcp_broken(ads,"connect/read","sent data before first request"); |
341 | return 0; |
342 | } |
343 | if (errno==EINTR) continue; |
344 | if (errno_resources(errno)) return errno; |
345 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
346 | return 0; |
347 | } /* not reached */ |
348 | case server_ok: |
349 | if (!(ads->tcpsend.used && fd == ads->tcpsocket)) break; |
350 | for (;;) { |
351 | adns__sigpipe_protect(ads); |
352 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
353 | adns__sigpipe_unprotect(ads); |
354 | if (r<0) { |
355 | if (errno==EINTR) continue; |
356 | if (errno==EAGAIN || errno==EWOULDBLOCK) return 0; |
357 | if (errno_resources(errno)) return errno; |
358 | adns__tcp_broken(ads,"write",strerror(errno)); |
359 | return 0; |
360 | } else if (r>0) { |
361 | ads->tcpsend.used -= r; |
362 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
363 | } |
364 | } /* not reached */ |
365 | default: |
366 | abort(); |
367 | } |
368 | return 0; |
369 | } |
370 | |
371 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now) { |
372 | switch (ads->tcpstate) { |
373 | case server_disconnected: |
374 | break; |
375 | case server_connecting: |
376 | case server_ok: |
377 | if (fd != ads->tcpsocket) break; |
378 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); |
379 | return 0; |
380 | default: |
381 | abort(); |
382 | } |
383 | return 0; |
384 | } |
37e28fde |
385 | |
620c146d |
386 | static void fd_event(adns_state ads, int fd, |
387 | int revent, int pollflag, |
388 | int maxfd, const fd_set *fds, |
389 | int (*func)(adns_state, int fd, const struct timeval *now), |
390 | struct timeval now, int *r_r) { |
656b2da9 |
391 | int r; |
620c146d |
392 | |
393 | if (!(revent & pollflag)) return; |
394 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; |
395 | r= func(ads,fd,&now); |
396 | if (r) { |
397 | if (r_r) { |
398 | *r_r= r; |
399 | } else { |
400 | adns__diag(ads,-1,0,"process fd failed after select: %s",strerror(errno)); |
401 | adns_globalsystemfailure(ads); |
402 | } |
403 | } |
404 | } |
405 | |
406 | void adns__fdevents(adns_state ads, |
407 | const struct pollfd *pollfds, int npollfds, |
408 | int maxfd, const fd_set *readfds, |
409 | const fd_set *writefds, const fd_set *exceptfds, |
410 | struct timeval now, int *r_r) { |
411 | int i, fd, revents; |
412 | |
413 | for (i=0; i<npollfds; i++) { |
414 | fd= pollfds[i].fd; |
415 | if (fd >= maxfd) maxfd= fd+1; |
416 | revents= pollfds[i].revents; |
417 | fd_event(ads,fd, revents,POLLIN, maxfd,readfds, adns_processreadable,now,r_r); |
418 | fd_event(ads,fd, revents,POLLOUT, maxfd,writefds, adns_processwriteable,now,r_r); |
419 | fd_event(ads,fd, revents,POLLPRI, maxfd,exceptfds, adns_processexceptional,now,r_r); |
420 | } |
421 | } |
37e28fde |
422 | |
620c146d |
423 | /* Wrappers for select(2). */ |
424 | |
425 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, |
426 | fd_set *writefds_io, fd_set *exceptfds_io, |
427 | struct timeval **tv_mod, struct timeval *tv_tobuf, |
428 | const struct timeval *now) { |
429 | struct timeval tv_nowbuf; |
430 | struct pollfd pollfds[MAX_POLLFDS]; |
431 | int i, fd, maxfd, npollfds; |
432 | |
433 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
434 | /* The caller is planning to sleep. */ |
435 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
436 | if (!now) return; |
437 | adns__timeouts(ads, 1, tv_mod,tv_tobuf, *now); |
438 | } |
439 | |
440 | npollfds= adns__pollfds(ads,pollfds); |
441 | maxfd= *maxfd_io; |
442 | for (i=0; i<npollfds; i++) { |
443 | fd= pollfds[i].fd; |
444 | if (fd >= maxfd) maxfd= fd+1; |
445 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); |
446 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); |
447 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); |
448 | } |
449 | *maxfd_io= maxfd; |
450 | } |
451 | |
452 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
453 | const fd_set *writefds, const fd_set *exceptfds, |
454 | const struct timeval *now) { |
fc6a52ae |
455 | struct timeval tv_buf; |
620c146d |
456 | struct pollfd pollfds[MAX_POLLFDS]; |
fc6a52ae |
457 | int npollfds, i; |
620c146d |
458 | |
fc6a52ae |
459 | adns__must_gettimeofday(ads,&now,&tv_buf); |
460 | if (!now) return; |
620c146d |
461 | adns_processtimeouts(ads,now); |
462 | |
463 | npollfds= adns__pollfds(ads,pollfds); |
fc6a52ae |
464 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
620c146d |
465 | adns__fdevents(ads, |
466 | pollfds,npollfds, |
467 | maxfd,readfds,writefds,exceptfds, |
468 | *now, 0); |
469 | } |
470 | |
471 | /* General helpful functions. */ |
472 | |
473 | void adns_globalsystemfailure(adns_state ads) { |
474 | while (ads->timew.head) { |
475 | adns__query_fail(ads->timew.head, adns_s_systemfail); |
476 | } |
477 | |
478 | switch (ads->tcpstate) { |
479 | case server_connecting: |
480 | case server_ok: |
481 | adns__tcp_closenext(ads); |
482 | break; |
483 | case server_disconnected: |
484 | break; |
485 | default: |
486 | abort(); |
487 | } |
656b2da9 |
488 | } |
489 | |
620c146d |
490 | int adns_processany(adns_state ads) { |
491 | int r; |
492 | struct timeval now; |
493 | struct pollfd pollfds[MAX_POLLFDS]; |
494 | int npollfds; |
495 | |
496 | r= gettimeofday(&now,0); |
497 | if (!r) adns_processtimeouts(ads,&now); |
498 | |
499 | npollfds= adns__pollfds(ads,pollfds); |
500 | adns__fdevents(ads, |
501 | pollfds,npollfds, |
502 | 0,0,0,0, |
503 | now,&r); |
504 | return r; |
505 | } |
ddfda861 |
506 | |
4353a5c4 |
507 | void adns__autosys(adns_state ads, struct timeval now) { |
ddfda861 |
508 | if (ads->iflags & adns_if_noautosys) return; |
620c146d |
509 | adns_processany(ads); |
ddfda861 |
510 | } |
511 | |
656b2da9 |
512 | static int internal_check(adns_state ads, |
513 | adns_query *query_io, |
514 | adns_answer **answer, |
515 | void **context_r) { |
516 | adns_query qu; |
517 | |
518 | qu= *query_io; |
519 | if (!qu) { |
520 | if (!ads->output.head) return EWOULDBLOCK; |
521 | qu= ads->output.head; |
522 | } else { |
523 | if (qu->id>=0) return EWOULDBLOCK; |
524 | } |
525 | LIST_UNLINK(ads->output,qu); |
8e5b0abb |
526 | *answer= qu->answer; |
a6536d8b |
527 | if (context_r) *context_r= qu->ctx.ext; |
8ce38e76 |
528 | *query_io= qu; |
656b2da9 |
529 | free(qu); |
530 | return 0; |
531 | } |
532 | |
533 | int adns_wait(adns_state ads, |
534 | adns_query *query_io, |
535 | adns_answer **answer_r, |
536 | void **context_r) { |
620c146d |
537 | int r, maxfd, rsel; |
656b2da9 |
538 | fd_set readfds, writefds, exceptfds; |
539 | struct timeval tvbuf, *tvp; |
540 | |
541 | for (;;) { |
542 | r= internal_check(ads,query_io,answer_r,context_r); |
94436798 |
543 | if (r != EWOULDBLOCK) return r; |
656b2da9 |
544 | maxfd= 0; tvp= 0; |
37e28fde |
545 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
620c146d |
546 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
656b2da9 |
547 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
88372443 |
548 | if (rsel==-1) { |
620c146d |
549 | if (errno == EINTR) { |
550 | if (ads->iflags & adns_if_eintr) return EINTR; |
551 | } else { |
552 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); |
553 | adns_globalsystemfailure(ads); |
554 | } |
555 | } else { |
556 | assert(rsel >= 0); |
557 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); |
88372443 |
558 | } |
656b2da9 |
559 | } |
560 | } |
561 | |
562 | int adns_check(adns_state ads, |
563 | adns_query *query_io, |
564 | adns_answer **answer_r, |
565 | void **context_r) { |
4353a5c4 |
566 | struct timeval now; |
567 | int r; |
568 | |
620c146d |
569 | r= gettimeofday(&now,0); |
570 | if (!r) adns__autosys(ads,now); |
571 | |
656b2da9 |
572 | return internal_check(ads,query_io,answer_r,context_r); |
573 | } |