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 | /* |
d942707d |
8 | * This file is |
9 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
10 | * |
11 | * It is part of adns, which is |
12 | * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk> |
13 | * Copyright (C) 1999 Tony Finch <dot@dotat.at> |
e576be50 |
14 | * |
15 | * This program is free software; you can redistribute it and/or modify |
16 | * it under the terms of the GNU General Public License as published by |
17 | * the Free Software Foundation; either version 2, or (at your option) |
18 | * any later version. |
19 | * |
20 | * This program is distributed in the hope that it will be useful, |
21 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
22 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
23 | * GNU General Public License for more details. |
24 | * |
25 | * You should have received a copy of the GNU General Public License |
26 | * along with this program; if not, write to the Free Software Foundation, |
27 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
28 | */ |
656b2da9 |
29 | |
4353a5c4 |
30 | #include <errno.h> |
31 | #include <stdlib.h> |
0f091044 |
32 | #include <unistd.h> |
4353a5c4 |
33 | |
0f091044 |
34 | #include <sys/types.h> |
35 | #include <sys/time.h> |
4353a5c4 |
36 | #include <netdb.h> |
eec1d9c8 |
37 | #include <sys/socket.h> |
38 | #include <netinet/in.h> |
4353a5c4 |
39 | #include <arpa/inet.h> |
40 | |
41 | #include "internal.h" |
37e28fde |
42 | |
620c146d |
43 | /* TCP connection management. */ |
44 | |
f7f83b4a |
45 | static void tcp_close(adns_state ads) { |
620c146d |
46 | int serv; |
47 | |
48 | serv= ads->tcpserver; |
49 | close(ads->tcpsocket); |
6a578b2c |
50 | ads->tcpsocket= -1; |
70ad7a2a |
51 | ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0; |
620c146d |
52 | } |
656b2da9 |
53 | |
8402e34c |
54 | void adns__tcp_broken(adns_state ads, const char *what, const char *why) { |
55 | int serv; |
56 | |
57 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); |
ddfda861 |
58 | serv= ads->tcpserver; |
f7f83b4a |
59 | if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why); |
60 | |
61 | tcp_close(ads); |
62 | ads->tcpstate= server_broken; |
63 | ads->tcpserver= (serv+1)%ads->nservers; |
8402e34c |
64 | } |
65 | |
ddfda861 |
66 | static void tcp_connected(adns_state ads, struct timeval now) { |
4353a5c4 |
67 | adns_query qu, nqu; |
68 | |
68442019 |
69 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
4353a5c4 |
70 | ads->tcpstate= server_ok; |
f7f83b4a |
71 | for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) { |
ddfda861 |
72 | nqu= qu->next; |
f7f83b4a |
73 | assert(qu->state == query_tcpw); |
74 | adns__querysend_tcp(qu,now); |
ddfda861 |
75 | } |
76 | } |
77 | |
78 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
8402e34c |
79 | int r, fd, tries; |
4353a5c4 |
80 | struct sockaddr_in addr; |
81 | struct protoent *proto; |
8402e34c |
82 | |
83 | for (tries=0; tries<ads->nservers; tries++) { |
f7f83b4a |
84 | switch (ads->tcpstate) { |
85 | case server_connecting: |
86 | case server_ok: |
87 | case server_broken: |
88 | return; |
89 | case server_disconnected: |
90 | break; |
91 | default: |
92 | abort(); |
93 | } |
94 | |
4353a5c4 |
95 | assert(!ads->tcpsend.used); |
96 | assert(!ads->tcprecv.used); |
70ad7a2a |
97 | assert(!ads->tcprecv_skip); |
8402e34c |
98 | |
99 | proto= getprotobyname("tcp"); |
68442019 |
100 | if (!proto) { adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); return; } |
8402e34c |
101 | fd= socket(AF_INET,SOCK_STREAM,proto->p_proto); |
4353a5c4 |
102 | if (fd<0) { |
68442019 |
103 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
4353a5c4 |
104 | return; |
105 | } |
106 | r= adns__setnonblock(ads,fd); |
107 | if (r) { |
68442019 |
108 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking: %s",strerror(r)); |
4353a5c4 |
109 | close(fd); |
110 | return; |
111 | } |
8402e34c |
112 | memset(&addr,0,sizeof(addr)); |
113 | addr.sin_family= AF_INET; |
98a3f706 |
114 | addr.sin_port= htons(DNS_PORT); |
8402e34c |
115 | addr.sin_addr= ads->servers[ads->tcpserver].addr; |
eec1d9c8 |
116 | r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr)); |
8402e34c |
117 | ads->tcpsocket= fd; |
118 | ads->tcpstate= server_connecting; |
f7f83b4a |
119 | if (r==0) { tcp_connected(ads,now); return; } |
120 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) { |
121 | ads->tcptimeout= now; |
122 | timevaladd(&ads->tcptimeout,TCPCONNMS); |
123 | return; |
124 | } |
ddfda861 |
125 | adns__tcp_broken(ads,"connect",strerror(errno)); |
f7f83b4a |
126 | ads->tcpstate= server_disconnected; |
8402e34c |
127 | } |
128 | } |
129 | |
620c146d |
130 | /* Timeout handling functions. */ |
131 | |
132 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
133 | struct timeval *tv_buf) { |
134 | const struct timeval *now; |
135 | int r; |
136 | |
137 | now= *now_io; |
138 | if (now) return; |
139 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } |
140 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); |
141 | adns_globalsystemfailure(ads); |
142 | return; |
143 | } |
4353a5c4 |
144 | |
145 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
146 | struct timeval maxto) { |
147 | struct timeval *rbuf; |
148 | |
149 | if (!tv_io) return; |
150 | rbuf= *tv_io; |
94436798 |
151 | if (!rbuf) { |
152 | *tvbuf= maxto; *tv_io= tvbuf; |
153 | } else { |
154 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
155 | } |
ffbda80c |
156 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
157 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ |
4353a5c4 |
158 | } |
159 | |
160 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
161 | struct timeval now, struct timeval maxtime) { |
f7f83b4a |
162 | /* tv_io may be 0 */ |
4353a5c4 |
163 | ldiv_t dr; |
164 | |
ffbda80c |
165 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
166 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ |
4353a5c4 |
167 | if (!tv_io) return; |
94436798 |
168 | maxtime.tv_sec -= (now.tv_sec+2); |
169 | maxtime.tv_usec -= (now.tv_usec-2000000); |
170 | dr= ldiv(maxtime.tv_usec,1000000); |
4353a5c4 |
171 | maxtime.tv_sec += dr.quot; |
94436798 |
172 | maxtime.tv_usec -= dr.quot*1000000; |
173 | if (maxtime.tv_sec<0) timerclear(&maxtime); |
4353a5c4 |
174 | inter_maxto(tv_io,tvbuf,maxtime); |
175 | } |
176 | |
f7f83b4a |
177 | static void timeouts_queue(adns_state ads, int act, |
178 | struct timeval **tv_io, struct timeval *tvbuf, |
179 | struct timeval now, struct query_queue *queue) { |
4353a5c4 |
180 | adns_query qu, nqu; |
f7f83b4a |
181 | |
182 | for (qu= queue->head; qu; qu= nqu) { |
4353a5c4 |
183 | nqu= qu->next; |
d855b532 |
184 | if (!timercmp(&now,&qu->timeout,>)) { |
620c146d |
185 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
186 | } else { |
3905bfc2 |
187 | if (!act) { |
6a9f9437 |
188 | tvbuf->tv_sec= 0; |
189 | tvbuf->tv_usec= 0; |
190 | *tv_io= tvbuf; |
3905bfc2 |
191 | return; |
192 | } |
f7f83b4a |
193 | LIST_UNLINK(*queue,qu); |
d8c062fa |
194 | if (qu->state != query_tosend) { |
3955725c |
195 | adns__query_fail(qu,adns_s_timeout); |
4353a5c4 |
196 | } else { |
d8c062fa |
197 | adns__query_send(qu,now); |
4353a5c4 |
198 | } |
f7f83b4a |
199 | nqu= queue->head; |
4353a5c4 |
200 | } |
201 | } |
f7f83b4a |
202 | } |
203 | |
204 | static void tcp_events(adns_state ads, int act, |
205 | struct timeval **tv_io, struct timeval *tvbuf, |
206 | struct timeval now) { |
207 | adns_query qu, nqu; |
208 | |
209 | for (;;) { |
210 | switch (ads->tcpstate) { |
211 | case server_broken: |
212 | for (qu= ads->tcpw.head; qu; qu= nqu) { |
213 | nqu= qu->next; |
214 | assert(qu->state == query_tcpw); |
215 | if (qu->retries > ads->nservers) { |
216 | LIST_UNLINK(ads->tcpw,qu); |
217 | adns__query_fail(qu,adns_s_allservfail); |
218 | } |
219 | } |
220 | ads->tcpstate= server_disconnected; |
221 | case server_disconnected: /* fall through */ |
222 | if (!ads->tcpw.head) return; |
223 | adns__tcp_tryconnect(ads,now); |
224 | break; |
225 | case server_ok: |
226 | if (ads->tcpw.head) return; |
227 | if (!ads->tcptimeout.tv_sec) { |
228 | assert(!ads->tcptimeout.tv_usec); |
229 | ads->tcptimeout= now; |
230 | timevaladd(&ads->tcptimeout,TCPIDLEMS); |
231 | } |
232 | case server_connecting: /* fall through */ |
233 | if (!timercmp(&now,&ads->tcptimeout,>)) { |
234 | inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout); |
235 | return; |
236 | } { |
237 | /* TCP timeout has happened */ |
238 | switch (ads->tcpstate) { |
239 | case server_connecting: /* failed to connect */ |
240 | adns__tcp_broken(ads,"unable to make connection","timed out"); |
241 | break; |
242 | case server_ok: /* idle timeout */ |
243 | tcp_close(ads); |
244 | ads->tcpstate= server_disconnected; |
245 | return; |
246 | default: |
247 | abort(); |
248 | } |
249 | } |
250 | break; |
251 | default: |
252 | abort(); |
253 | } |
254 | } |
255 | } |
256 | |
257 | void adns__timeouts(adns_state ads, int act, |
258 | struct timeval **tv_io, struct timeval *tvbuf, |
259 | struct timeval now) { |
260 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw); |
261 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw); |
262 | tcp_events(ads,act,tv_io,tvbuf,now); |
263 | } |
94436798 |
264 | |
620c146d |
265 | void adns_firsttimeout(adns_state ads, |
266 | struct timeval **tv_io, struct timeval *tvbuf, |
267 | struct timeval now) { |
28de6442 |
268 | adns__consistency(ads,0,cc_entex); |
620c146d |
269 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
28de6442 |
270 | adns__consistency(ads,0,cc_entex); |
620c146d |
271 | } |
272 | |
273 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { |
274 | struct timeval tv_buf; |
275 | |
28de6442 |
276 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
277 | adns__must_gettimeofday(ads,&now,&tv_buf); |
278 | if (now) adns__timeouts(ads, 1, 0,0, *now); |
28de6442 |
279 | adns__consistency(ads,0,cc_entex); |
a8768e80 |
280 | } |
281 | |
620c146d |
282 | /* fd handling functions. These are the top-level of the real work of |
283 | * reception and often transmission. |
284 | */ |
285 | |
286 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { |
287 | /* Returns the number of entries filled in. Always zeroes revents. */ |
288 | |
289 | assert(MAX_POLLFDS==2); |
a8768e80 |
290 | |
620c146d |
291 | pollfds_buf[0].fd= ads->udpsocket; |
292 | pollfds_buf[0].events= POLLIN; |
293 | pollfds_buf[0].revents= 0; |
4353a5c4 |
294 | |
295 | switch (ads->tcpstate) { |
296 | case server_disconnected: |
620c146d |
297 | return 1; |
4353a5c4 |
298 | case server_connecting: |
620c146d |
299 | pollfds_buf[1].events= POLLOUT; |
4353a5c4 |
300 | break; |
301 | case server_ok: |
620c146d |
302 | pollfds_buf[1].events= ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI; |
e062dcae |
303 | break; |
4353a5c4 |
304 | default: |
305 | abort(); |
306 | } |
620c146d |
307 | pollfds_buf[1].fd= ads->tcpsocket; |
620c146d |
308 | return 2; |
4353a5c4 |
309 | } |
310 | |
620c146d |
311 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
70ad7a2a |
312 | int want, dgramlen, r, udpaddrlen, serv, old_skip; |
98a3f706 |
313 | byte udpbuf[DNS_MAXUDP]; |
37e28fde |
314 | struct sockaddr_in udpaddr; |
620c146d |
315 | |
28de6442 |
316 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
317 | |
ddfda861 |
318 | switch (ads->tcpstate) { |
319 | case server_disconnected: |
ddfda861 |
320 | case server_connecting: |
ddfda861 |
321 | break; |
322 | case server_ok: |
620c146d |
323 | if (fd != ads->tcpsocket) break; |
70ad7a2a |
324 | assert(!ads->tcprecv_skip); |
620c146d |
325 | for (;;) { |
70ad7a2a |
326 | if (ads->tcprecv.used >= ads->tcprecv_skip+2) { |
327 | dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) | |
328 | ads->tcprecv.buf[ads->tcprecv_skip+1]); |
329 | if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) { |
330 | old_skip= ads->tcprecv_skip; |
331 | ads->tcprecv_skip += 2+dgramlen; |
332 | adns__procdgram(ads, ads->tcprecv.buf+old_skip+2, |
333 | dgramlen, ads->tcpserver, 1,*now); |
334 | continue; |
656b2da9 |
335 | } else { |
70ad7a2a |
336 | want= 2+dgramlen; |
656b2da9 |
337 | } |
70ad7a2a |
338 | } else { |
339 | want= 2; |
656b2da9 |
340 | } |
70ad7a2a |
341 | ads->tcprecv.used -= ads->tcprecv_skip; |
342 | memmove(ads->tcprecv.buf,ads->tcprecv.buf+ads->tcprecv_skip,ads->tcprecv.used); |
343 | ads->tcprecv_skip= 0; |
3e2e5fab |
344 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; } |
620c146d |
345 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
346 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; |
347 | r= read(ads->tcpsocket, |
348 | ads->tcprecv.buf+ads->tcprecv.used, |
349 | ads->tcprecv.avail-ads->tcprecv.used); |
350 | if (r>0) { |
351 | ads->tcprecv.used+= r; |
352 | } else { |
353 | if (r) { |
3e2e5fab |
354 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
355 | if (errno==EINTR) continue; |
3e2e5fab |
356 | if (errno_resources(errno)) { r= errno; goto xit; } |
656b2da9 |
357 | } |
620c146d |
358 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
3e2e5fab |
359 | r= 0; goto xit; |
656b2da9 |
360 | } |
620c146d |
361 | } /* never reached */ |
ddfda861 |
362 | default: |
363 | abort(); |
656b2da9 |
364 | } |
620c146d |
365 | if (fd == ads->udpsocket) { |
37e28fde |
366 | for (;;) { |
367 | udpaddrlen= sizeof(udpaddr); |
eec1d9c8 |
368 | r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0, |
369 | (struct sockaddr*)&udpaddr,&udpaddrlen); |
37e28fde |
370 | if (r<0) { |
3e2e5fab |
371 | if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
372 | if (errno == EINTR) continue; |
3e2e5fab |
373 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
374 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); |
3e2e5fab |
375 | r= 0; goto xit; |
37e28fde |
376 | } |
377 | if (udpaddrlen != sizeof(udpaddr)) { |
68442019 |
378 | adns__diag(ads,-1,0,"datagram received with wrong address length %d" |
379 | " (expected %d)", udpaddrlen,sizeof(udpaddr)); |
37e28fde |
380 | continue; |
381 | } |
382 | if (udpaddr.sin_family != AF_INET) { |
68442019 |
383 | adns__diag(ads,-1,0,"datagram received with wrong protocol family" |
4353a5c4 |
384 | " %u (expected %u)",udpaddr.sin_family,AF_INET); |
37e28fde |
385 | continue; |
386 | } |
98a3f706 |
387 | if (ntohs(udpaddr.sin_port) != DNS_PORT) { |
68442019 |
388 | adns__diag(ads,-1,0,"datagram received from wrong port %u (expected %u)", |
98a3f706 |
389 | ntohs(udpaddr.sin_port),DNS_PORT); |
37e28fde |
390 | continue; |
391 | } |
392 | for (serv= 0; |
393 | serv < ads->nservers && |
394 | ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; |
395 | serv++); |
396 | if (serv >= ads->nservers) { |
68442019 |
397 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", |
4353a5c4 |
398 | inet_ntoa(udpaddr.sin_addr)); |
37e28fde |
399 | continue; |
400 | } |
ebf4877a |
401 | adns__procdgram(ads,udpbuf,r,serv,0,*now); |
656b2da9 |
402 | } |
37e28fde |
403 | } |
3e2e5fab |
404 | r= 0; |
405 | xit: |
28de6442 |
406 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
407 | return r; |
656b2da9 |
408 | } |
656b2da9 |
409 | |
620c146d |
410 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
656b2da9 |
411 | int r; |
620c146d |
412 | |
28de6442 |
413 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
414 | |
620c146d |
415 | switch (ads->tcpstate) { |
416 | case server_disconnected: |
417 | break; |
418 | case server_connecting: |
419 | if (fd != ads->tcpsocket) break; |
420 | assert(ads->tcprecv.used==0); |
70ad7a2a |
421 | assert(ads->tcprecv_skip==0); |
620c146d |
422 | for (;;) { |
3e2e5fab |
423 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; } |
620c146d |
424 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
425 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
426 | tcp_connected(ads,*now); |
3e2e5fab |
427 | r= 0; goto xit; |
620c146d |
428 | } |
429 | if (r>0) { |
430 | adns__tcp_broken(ads,"connect/read","sent data before first request"); |
3e2e5fab |
431 | r= 0; goto xit; |
620c146d |
432 | } |
433 | if (errno==EINTR) continue; |
3e2e5fab |
434 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
435 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
3e2e5fab |
436 | r= 0; goto xit; |
620c146d |
437 | } /* not reached */ |
438 | case server_ok: |
439 | if (!(ads->tcpsend.used && fd == ads->tcpsocket)) break; |
440 | for (;;) { |
441 | adns__sigpipe_protect(ads); |
442 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
443 | adns__sigpipe_unprotect(ads); |
444 | if (r<0) { |
445 | if (errno==EINTR) continue; |
3e2e5fab |
446 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
447 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
448 | adns__tcp_broken(ads,"write",strerror(errno)); |
3e2e5fab |
449 | r= 0; goto xit; |
620c146d |
450 | } else if (r>0) { |
451 | ads->tcpsend.used -= r; |
452 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
453 | } |
454 | } /* not reached */ |
455 | default: |
456 | abort(); |
457 | } |
3e2e5fab |
458 | r= 0; |
459 | xit: |
28de6442 |
460 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
461 | return r; |
620c146d |
462 | } |
463 | |
464 | int adns_processexceptional(adns_state ads, int fd, const struct timeval *now) { |
28de6442 |
465 | adns__consistency(ads,0,cc_entex); |
620c146d |
466 | switch (ads->tcpstate) { |
467 | case server_disconnected: |
468 | break; |
469 | case server_connecting: |
470 | case server_ok: |
471 | if (fd != ads->tcpsocket) break; |
472 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); |
3e2e5fab |
473 | break; |
620c146d |
474 | default: |
475 | abort(); |
476 | } |
28de6442 |
477 | adns__consistency(ads,0,cc_entex); |
620c146d |
478 | return 0; |
479 | } |
37e28fde |
480 | |
620c146d |
481 | static void fd_event(adns_state ads, int fd, |
482 | int revent, int pollflag, |
483 | int maxfd, const fd_set *fds, |
484 | int (*func)(adns_state, int fd, const struct timeval *now), |
485 | struct timeval now, int *r_r) { |
656b2da9 |
486 | int r; |
620c146d |
487 | |
488 | if (!(revent & pollflag)) return; |
489 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; |
490 | r= func(ads,fd,&now); |
491 | if (r) { |
492 | if (r_r) { |
493 | *r_r= r; |
494 | } else { |
495 | adns__diag(ads,-1,0,"process fd failed after select: %s",strerror(errno)); |
496 | adns_globalsystemfailure(ads); |
497 | } |
498 | } |
499 | } |
500 | |
501 | void adns__fdevents(adns_state ads, |
502 | const struct pollfd *pollfds, int npollfds, |
503 | int maxfd, const fd_set *readfds, |
504 | const fd_set *writefds, const fd_set *exceptfds, |
505 | struct timeval now, int *r_r) { |
506 | int i, fd, revents; |
507 | |
508 | for (i=0; i<npollfds; i++) { |
509 | fd= pollfds[i].fd; |
510 | if (fd >= maxfd) maxfd= fd+1; |
511 | revents= pollfds[i].revents; |
512 | fd_event(ads,fd, revents,POLLIN, maxfd,readfds, adns_processreadable,now,r_r); |
513 | fd_event(ads,fd, revents,POLLOUT, maxfd,writefds, adns_processwriteable,now,r_r); |
514 | fd_event(ads,fd, revents,POLLPRI, maxfd,exceptfds, adns_processexceptional,now,r_r); |
515 | } |
516 | } |
37e28fde |
517 | |
620c146d |
518 | /* Wrappers for select(2). */ |
519 | |
520 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, |
521 | fd_set *writefds_io, fd_set *exceptfds_io, |
522 | struct timeval **tv_mod, struct timeval *tv_tobuf, |
523 | const struct timeval *now) { |
524 | struct timeval tv_nowbuf; |
525 | struct pollfd pollfds[MAX_POLLFDS]; |
526 | int i, fd, maxfd, npollfds; |
527 | |
28de6442 |
528 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
529 | |
620c146d |
530 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
531 | /* The caller is planning to sleep. */ |
532 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
3e2e5fab |
533 | if (!now) goto xit; |
620c146d |
534 | adns__timeouts(ads, 1, tv_mod,tv_tobuf, *now); |
535 | } |
536 | |
537 | npollfds= adns__pollfds(ads,pollfds); |
538 | maxfd= *maxfd_io; |
539 | for (i=0; i<npollfds; i++) { |
540 | fd= pollfds[i].fd; |
541 | if (fd >= maxfd) maxfd= fd+1; |
542 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); |
543 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); |
544 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); |
545 | } |
546 | *maxfd_io= maxfd; |
3e2e5fab |
547 | |
548 | xit: |
28de6442 |
549 | adns__consistency(ads,0,cc_entex); |
620c146d |
550 | } |
551 | |
552 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
553 | const fd_set *writefds, const fd_set *exceptfds, |
554 | const struct timeval *now) { |
fc6a52ae |
555 | struct timeval tv_buf; |
620c146d |
556 | struct pollfd pollfds[MAX_POLLFDS]; |
fc6a52ae |
557 | int npollfds, i; |
620c146d |
558 | |
28de6442 |
559 | adns__consistency(ads,0,cc_entex); |
fc6a52ae |
560 | adns__must_gettimeofday(ads,&now,&tv_buf); |
3e2e5fab |
561 | if (!now) goto xit; |
620c146d |
562 | adns_processtimeouts(ads,now); |
563 | |
564 | npollfds= adns__pollfds(ads,pollfds); |
fc6a52ae |
565 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
620c146d |
566 | adns__fdevents(ads, |
567 | pollfds,npollfds, |
568 | maxfd,readfds,writefds,exceptfds, |
569 | *now, 0); |
3e2e5fab |
570 | xit: |
28de6442 |
571 | adns__consistency(ads,0,cc_entex); |
620c146d |
572 | } |
573 | |
574 | /* General helpful functions. */ |
575 | |
576 | void adns_globalsystemfailure(adns_state ads) { |
28de6442 |
577 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
578 | |
f7f83b4a |
579 | while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail); |
580 | while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail); |
620c146d |
581 | |
582 | switch (ads->tcpstate) { |
583 | case server_connecting: |
584 | case server_ok: |
f7f83b4a |
585 | adns__tcp_broken(ads,0,0); |
620c146d |
586 | break; |
587 | case server_disconnected: |
588 | break; |
589 | default: |
590 | abort(); |
591 | } |
28de6442 |
592 | adns__consistency(ads,0,cc_entex); |
656b2da9 |
593 | } |
594 | |
620c146d |
595 | int adns_processany(adns_state ads) { |
aedf10f2 |
596 | int r, i; |
620c146d |
597 | struct timeval now; |
598 | struct pollfd pollfds[MAX_POLLFDS]; |
599 | int npollfds; |
600 | |
28de6442 |
601 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
602 | |
620c146d |
603 | r= gettimeofday(&now,0); |
604 | if (!r) adns_processtimeouts(ads,&now); |
605 | |
25913ee2 |
606 | /* We just use adns__fdevents to loop over the fd's trying them. |
607 | * This seems more sensible than calling select, since we're most |
608 | * likely just to want to do a read on one or two fds anyway. |
609 | */ |
620c146d |
610 | npollfds= adns__pollfds(ads,pollfds); |
aedf10f2 |
611 | for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events; |
620c146d |
612 | adns__fdevents(ads, |
613 | pollfds,npollfds, |
614 | 0,0,0,0, |
615 | now,&r); |
3e2e5fab |
616 | |
28de6442 |
617 | adns__consistency(ads,0,cc_entex); |
c118a725 |
618 | return 0; |
620c146d |
619 | } |
ddfda861 |
620 | |
4353a5c4 |
621 | void adns__autosys(adns_state ads, struct timeval now) { |
ddfda861 |
622 | if (ads->iflags & adns_if_noautosys) return; |
620c146d |
623 | adns_processany(ads); |
ddfda861 |
624 | } |
625 | |
940356bd |
626 | int adns__internal_check(adns_state ads, |
627 | adns_query *query_io, |
628 | adns_answer **answer, |
629 | void **context_r) { |
656b2da9 |
630 | adns_query qu; |
631 | |
632 | qu= *query_io; |
633 | if (!qu) { |
4ae90a83 |
634 | if (ads->output.head) { |
635 | qu= ads->output.head; |
f7f83b4a |
636 | } else if (ads->udpw.head || ads->tcpw.head) { |
4ae90a83 |
637 | return EAGAIN; |
638 | } else { |
639 | return ESRCH; |
640 | } |
656b2da9 |
641 | } else { |
226c5eef |
642 | if (qu->id>=0) return EAGAIN; |
656b2da9 |
643 | } |
644 | LIST_UNLINK(ads->output,qu); |
8e5b0abb |
645 | *answer= qu->answer; |
a6536d8b |
646 | if (context_r) *context_r= qu->ctx.ext; |
8ce38e76 |
647 | *query_io= qu; |
656b2da9 |
648 | free(qu); |
649 | return 0; |
650 | } |
651 | |
652 | int adns_wait(adns_state ads, |
653 | adns_query *query_io, |
654 | adns_answer **answer_r, |
655 | void **context_r) { |
620c146d |
656 | int r, maxfd, rsel; |
656b2da9 |
657 | fd_set readfds, writefds, exceptfds; |
658 | struct timeval tvbuf, *tvp; |
659 | |
28de6442 |
660 | adns__consistency(ads,*query_io,cc_entex); |
656b2da9 |
661 | for (;;) { |
940356bd |
662 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
226c5eef |
663 | if (r != EAGAIN) break; |
656b2da9 |
664 | maxfd= 0; tvp= 0; |
37e28fde |
665 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
620c146d |
666 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
656b2da9 |
667 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
88372443 |
668 | if (rsel==-1) { |
620c146d |
669 | if (errno == EINTR) { |
3e2e5fab |
670 | if (ads->iflags & adns_if_eintr) { r= EINTR; break; } |
620c146d |
671 | } else { |
672 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); |
673 | adns_globalsystemfailure(ads); |
674 | } |
675 | } else { |
676 | assert(rsel >= 0); |
677 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); |
88372443 |
678 | } |
656b2da9 |
679 | } |
28de6442 |
680 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
681 | return r; |
656b2da9 |
682 | } |
683 | |
684 | int adns_check(adns_state ads, |
685 | adns_query *query_io, |
686 | adns_answer **answer_r, |
687 | void **context_r) { |
4353a5c4 |
688 | struct timeval now; |
689 | int r; |
690 | |
28de6442 |
691 | adns__consistency(ads,*query_io,cc_entex); |
620c146d |
692 | r= gettimeofday(&now,0); |
693 | if (!r) adns__autosys(ads,now); |
3e2e5fab |
694 | |
940356bd |
695 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
28de6442 |
696 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
697 | return r; |
656b2da9 |
698 | } |