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 |
3d5cde09 |
9 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
d942707d |
10 | * |
11 | * It is part of adns, which is |
3d5cde09 |
12 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
bef232ae |
13 | * Copyright (C) 1999-2000 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" |
2953d358 |
42 | #include "tvarith.h" |
37e28fde |
43 | |
620c146d |
44 | /* TCP connection management. */ |
45 | |
f7f83b4a |
46 | static void tcp_close(adns_state ads) { |
620c146d |
47 | int serv; |
48 | |
49 | serv= ads->tcpserver; |
50 | close(ads->tcpsocket); |
6a578b2c |
51 | ads->tcpsocket= -1; |
70ad7a2a |
52 | ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0; |
620c146d |
53 | } |
656b2da9 |
54 | |
8402e34c |
55 | void adns__tcp_broken(adns_state ads, const char *what, const char *why) { |
56 | int serv; |
fb901bf5 |
57 | adns_query qu; |
8402e34c |
58 | |
59 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); |
ddfda861 |
60 | serv= ads->tcpserver; |
f7f83b4a |
61 | if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why); |
62 | |
fb901bf5 |
63 | if (ads->tcpstate == server_connecting) { |
64 | /* Counts as a retry for all the queries waiting for TCP. */ |
65 | for (qu= ads->tcpw.head; qu; qu= qu->next) |
66 | qu->retries++; |
67 | } |
68 | |
f7f83b4a |
69 | tcp_close(ads); |
70 | ads->tcpstate= server_broken; |
71 | ads->tcpserver= (serv+1)%ads->nservers; |
8402e34c |
72 | } |
73 | |
ddfda861 |
74 | static void tcp_connected(adns_state ads, struct timeval now) { |
4353a5c4 |
75 | adns_query qu, nqu; |
76 | |
68442019 |
77 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
4353a5c4 |
78 | ads->tcpstate= server_ok; |
f7f83b4a |
79 | for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) { |
ddfda861 |
80 | nqu= qu->next; |
f7f83b4a |
81 | assert(qu->state == query_tcpw); |
82 | adns__querysend_tcp(qu,now); |
ddfda861 |
83 | } |
84 | } |
85 | |
86 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
8402e34c |
87 | int r, fd, tries; |
4353a5c4 |
88 | struct sockaddr_in addr; |
89 | struct protoent *proto; |
8402e34c |
90 | |
91 | for (tries=0; tries<ads->nservers; tries++) { |
f7f83b4a |
92 | switch (ads->tcpstate) { |
93 | case server_connecting: |
94 | case server_ok: |
95 | case server_broken: |
96 | return; |
97 | case server_disconnected: |
98 | break; |
99 | default: |
100 | abort(); |
101 | } |
102 | |
4353a5c4 |
103 | assert(!ads->tcpsend.used); |
104 | assert(!ads->tcprecv.used); |
70ad7a2a |
105 | assert(!ads->tcprecv_skip); |
8402e34c |
106 | |
107 | proto= getprotobyname("tcp"); |
609133ee |
108 | if (!proto) { |
109 | adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); |
110 | return; |
111 | } |
8402e34c |
112 | fd= socket(AF_INET,SOCK_STREAM,proto->p_proto); |
4353a5c4 |
113 | if (fd<0) { |
68442019 |
114 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
4353a5c4 |
115 | return; |
116 | } |
117 | r= adns__setnonblock(ads,fd); |
118 | if (r) { |
609133ee |
119 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking:" |
120 | " %s",strerror(r)); |
4353a5c4 |
121 | close(fd); |
122 | return; |
123 | } |
8402e34c |
124 | memset(&addr,0,sizeof(addr)); |
125 | addr.sin_family= AF_INET; |
98a3f706 |
126 | addr.sin_port= htons(DNS_PORT); |
8402e34c |
127 | addr.sin_addr= ads->servers[ads->tcpserver].addr; |
eec1d9c8 |
128 | r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr)); |
8402e34c |
129 | ads->tcpsocket= fd; |
130 | ads->tcpstate= server_connecting; |
f7f83b4a |
131 | if (r==0) { tcp_connected(ads,now); return; } |
132 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) { |
133 | ads->tcptimeout= now; |
134 | timevaladd(&ads->tcptimeout,TCPCONNMS); |
135 | return; |
136 | } |
ddfda861 |
137 | adns__tcp_broken(ads,"connect",strerror(errno)); |
f7f83b4a |
138 | ads->tcpstate= server_disconnected; |
8402e34c |
139 | } |
140 | } |
141 | |
620c146d |
142 | /* Timeout handling functions. */ |
143 | |
144 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
145 | struct timeval *tv_buf) { |
146 | const struct timeval *now; |
147 | int r; |
148 | |
149 | now= *now_io; |
150 | if (now) return; |
151 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } |
152 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); |
153 | adns_globalsystemfailure(ads); |
154 | return; |
155 | } |
4353a5c4 |
156 | |
4fad263d |
157 | static void inter_immed(struct timeval **tv_io, struct timeval *tvbuf) { |
158 | struct timeval *rbuf; |
159 | |
160 | if (!tv_io) return; |
161 | |
162 | rbuf= *tv_io; |
163 | if (!rbuf) { *tv_io= rbuf= tvbuf; } |
164 | |
165 | timerclear(rbuf); |
166 | } |
167 | |
4353a5c4 |
168 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
169 | struct timeval maxto) { |
170 | struct timeval *rbuf; |
171 | |
172 | if (!tv_io) return; |
173 | rbuf= *tv_io; |
94436798 |
174 | if (!rbuf) { |
175 | *tvbuf= maxto; *tv_io= tvbuf; |
176 | } else { |
177 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
178 | } |
ffbda80c |
179 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
180 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ |
4353a5c4 |
181 | } |
182 | |
183 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
184 | struct timeval now, struct timeval maxtime) { |
f7f83b4a |
185 | /* tv_io may be 0 */ |
4353a5c4 |
186 | ldiv_t dr; |
187 | |
ffbda80c |
188 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
189 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ |
4353a5c4 |
190 | if (!tv_io) return; |
94436798 |
191 | maxtime.tv_sec -= (now.tv_sec+2); |
192 | maxtime.tv_usec -= (now.tv_usec-2000000); |
193 | dr= ldiv(maxtime.tv_usec,1000000); |
4353a5c4 |
194 | maxtime.tv_sec += dr.quot; |
94436798 |
195 | maxtime.tv_usec -= dr.quot*1000000; |
196 | if (maxtime.tv_sec<0) timerclear(&maxtime); |
4353a5c4 |
197 | inter_maxto(tv_io,tvbuf,maxtime); |
198 | } |
199 | |
f7f83b4a |
200 | static void timeouts_queue(adns_state ads, int act, |
201 | struct timeval **tv_io, struct timeval *tvbuf, |
202 | struct timeval now, struct query_queue *queue) { |
4353a5c4 |
203 | adns_query qu, nqu; |
f7f83b4a |
204 | |
205 | for (qu= queue->head; qu; qu= nqu) { |
4353a5c4 |
206 | nqu= qu->next; |
d855b532 |
207 | if (!timercmp(&now,&qu->timeout,>)) { |
620c146d |
208 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
209 | } else { |
4fad263d |
210 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a |
211 | LIST_UNLINK(*queue,qu); |
d8c062fa |
212 | if (qu->state != query_tosend) { |
3955725c |
213 | adns__query_fail(qu,adns_s_timeout); |
4353a5c4 |
214 | } else { |
d8c062fa |
215 | adns__query_send(qu,now); |
4353a5c4 |
216 | } |
f7f83b4a |
217 | nqu= queue->head; |
4353a5c4 |
218 | } |
219 | } |
f7f83b4a |
220 | } |
221 | |
222 | static void tcp_events(adns_state ads, int act, |
223 | struct timeval **tv_io, struct timeval *tvbuf, |
224 | struct timeval now) { |
225 | adns_query qu, nqu; |
226 | |
227 | for (;;) { |
228 | switch (ads->tcpstate) { |
229 | case server_broken: |
4fad263d |
230 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a |
231 | for (qu= ads->tcpw.head; qu; qu= nqu) { |
232 | nqu= qu->next; |
233 | assert(qu->state == query_tcpw); |
234 | if (qu->retries > ads->nservers) { |
235 | LIST_UNLINK(ads->tcpw,qu); |
236 | adns__query_fail(qu,adns_s_allservfail); |
237 | } |
238 | } |
239 | ads->tcpstate= server_disconnected; |
240 | case server_disconnected: /* fall through */ |
241 | if (!ads->tcpw.head) return; |
4fad263d |
242 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a |
243 | adns__tcp_tryconnect(ads,now); |
244 | break; |
245 | case server_ok: |
246 | if (ads->tcpw.head) return; |
247 | if (!ads->tcptimeout.tv_sec) { |
248 | assert(!ads->tcptimeout.tv_usec); |
249 | ads->tcptimeout= now; |
250 | timevaladd(&ads->tcptimeout,TCPIDLEMS); |
251 | } |
252 | case server_connecting: /* fall through */ |
4fad263d |
253 | if (!act || !timercmp(&now,&ads->tcptimeout,>)) { |
f7f83b4a |
254 | inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout); |
255 | return; |
256 | } { |
257 | /* TCP timeout has happened */ |
258 | switch (ads->tcpstate) { |
259 | case server_connecting: /* failed to connect */ |
260 | adns__tcp_broken(ads,"unable to make connection","timed out"); |
261 | break; |
262 | case server_ok: /* idle timeout */ |
263 | tcp_close(ads); |
264 | ads->tcpstate= server_disconnected; |
265 | return; |
266 | default: |
267 | abort(); |
268 | } |
269 | } |
270 | break; |
271 | default: |
272 | abort(); |
273 | } |
274 | } |
4fad263d |
275 | return; |
f7f83b4a |
276 | } |
277 | |
278 | void adns__timeouts(adns_state ads, int act, |
279 | struct timeval **tv_io, struct timeval *tvbuf, |
280 | struct timeval now) { |
281 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw); |
282 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw); |
283 | tcp_events(ads,act,tv_io,tvbuf,now); |
284 | } |
94436798 |
285 | |
620c146d |
286 | void adns_firsttimeout(adns_state ads, |
287 | struct timeval **tv_io, struct timeval *tvbuf, |
288 | struct timeval now) { |
28de6442 |
289 | adns__consistency(ads,0,cc_entex); |
620c146d |
290 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
28de6442 |
291 | adns__consistency(ads,0,cc_entex); |
620c146d |
292 | } |
293 | |
294 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { |
295 | struct timeval tv_buf; |
296 | |
28de6442 |
297 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
298 | adns__must_gettimeofday(ads,&now,&tv_buf); |
299 | if (now) adns__timeouts(ads, 1, 0,0, *now); |
28de6442 |
300 | adns__consistency(ads,0,cc_entex); |
a8768e80 |
301 | } |
302 | |
620c146d |
303 | /* fd handling functions. These are the top-level of the real work of |
304 | * reception and often transmission. |
305 | */ |
306 | |
307 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { |
308 | /* Returns the number of entries filled in. Always zeroes revents. */ |
309 | |
310 | assert(MAX_POLLFDS==2); |
a8768e80 |
311 | |
620c146d |
312 | pollfds_buf[0].fd= ads->udpsocket; |
313 | pollfds_buf[0].events= POLLIN; |
314 | pollfds_buf[0].revents= 0; |
4353a5c4 |
315 | |
316 | switch (ads->tcpstate) { |
317 | case server_disconnected: |
6c68a593 |
318 | case server_broken: |
620c146d |
319 | return 1; |
4353a5c4 |
320 | case server_connecting: |
620c146d |
321 | pollfds_buf[1].events= POLLOUT; |
4353a5c4 |
322 | break; |
323 | case server_ok: |
609133ee |
324 | pollfds_buf[1].events= |
325 | ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI; |
e062dcae |
326 | break; |
4353a5c4 |
327 | default: |
328 | abort(); |
329 | } |
620c146d |
330 | pollfds_buf[1].fd= ads->tcpsocket; |
620c146d |
331 | return 2; |
4353a5c4 |
332 | } |
333 | |
620c146d |
334 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
70ad7a2a |
335 | int want, dgramlen, r, udpaddrlen, serv, old_skip; |
98a3f706 |
336 | byte udpbuf[DNS_MAXUDP]; |
37e28fde |
337 | struct sockaddr_in udpaddr; |
620c146d |
338 | |
28de6442 |
339 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
340 | |
ddfda861 |
341 | switch (ads->tcpstate) { |
342 | case server_disconnected: |
fb901bf5 |
343 | case server_broken: |
ddfda861 |
344 | case server_connecting: |
ddfda861 |
345 | break; |
346 | case server_ok: |
620c146d |
347 | if (fd != ads->tcpsocket) break; |
70ad7a2a |
348 | assert(!ads->tcprecv_skip); |
428bd682 |
349 | do { |
70ad7a2a |
350 | if (ads->tcprecv.used >= ads->tcprecv_skip+2) { |
351 | dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) | |
352 | ads->tcprecv.buf[ads->tcprecv_skip+1]); |
353 | if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) { |
354 | old_skip= ads->tcprecv_skip; |
355 | ads->tcprecv_skip += 2+dgramlen; |
356 | adns__procdgram(ads, ads->tcprecv.buf+old_skip+2, |
357 | dgramlen, ads->tcpserver, 1,*now); |
358 | continue; |
656b2da9 |
359 | } else { |
70ad7a2a |
360 | want= 2+dgramlen; |
656b2da9 |
361 | } |
70ad7a2a |
362 | } else { |
363 | want= 2; |
656b2da9 |
364 | } |
70ad7a2a |
365 | ads->tcprecv.used -= ads->tcprecv_skip; |
609133ee |
366 | memmove(ads->tcprecv.buf, ads->tcprecv.buf+ads->tcprecv_skip, |
367 | ads->tcprecv.used); |
70ad7a2a |
368 | ads->tcprecv_skip= 0; |
3e2e5fab |
369 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; } |
620c146d |
370 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
371 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; |
372 | r= read(ads->tcpsocket, |
373 | ads->tcprecv.buf+ads->tcprecv.used, |
374 | ads->tcprecv.avail-ads->tcprecv.used); |
375 | if (r>0) { |
376 | ads->tcprecv.used+= r; |
377 | } else { |
378 | if (r) { |
3e2e5fab |
379 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
380 | if (errno==EINTR) continue; |
3e2e5fab |
381 | if (errno_resources(errno)) { r= errno; goto xit; } |
656b2da9 |
382 | } |
620c146d |
383 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
656b2da9 |
384 | } |
428bd682 |
385 | } while (ads->tcpstate == server_ok); |
386 | r= 0; goto xit; |
ddfda861 |
387 | default: |
388 | abort(); |
656b2da9 |
389 | } |
620c146d |
390 | if (fd == ads->udpsocket) { |
37e28fde |
391 | for (;;) { |
392 | udpaddrlen= sizeof(udpaddr); |
eec1d9c8 |
393 | r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0, |
394 | (struct sockaddr*)&udpaddr,&udpaddrlen); |
37e28fde |
395 | if (r<0) { |
3e2e5fab |
396 | if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
397 | if (errno == EINTR) continue; |
3e2e5fab |
398 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
399 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); |
3e2e5fab |
400 | r= 0; goto xit; |
37e28fde |
401 | } |
402 | if (udpaddrlen != sizeof(udpaddr)) { |
68442019 |
403 | adns__diag(ads,-1,0,"datagram received with wrong address length %d" |
5a0be244 |
404 | " (expected %lu)", udpaddrlen, |
405 | (unsigned long)sizeof(udpaddr)); |
37e28fde |
406 | continue; |
407 | } |
408 | if (udpaddr.sin_family != AF_INET) { |
68442019 |
409 | adns__diag(ads,-1,0,"datagram received with wrong protocol family" |
4353a5c4 |
410 | " %u (expected %u)",udpaddr.sin_family,AF_INET); |
37e28fde |
411 | continue; |
412 | } |
98a3f706 |
413 | if (ntohs(udpaddr.sin_port) != DNS_PORT) { |
609133ee |
414 | adns__diag(ads,-1,0,"datagram received from wrong port" |
415 | " %u (expected %u)", ntohs(udpaddr.sin_port),DNS_PORT); |
37e28fde |
416 | continue; |
417 | } |
418 | for (serv= 0; |
419 | serv < ads->nservers && |
420 | ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; |
421 | serv++); |
422 | if (serv >= ads->nservers) { |
68442019 |
423 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", |
4353a5c4 |
424 | inet_ntoa(udpaddr.sin_addr)); |
37e28fde |
425 | continue; |
426 | } |
ebf4877a |
427 | adns__procdgram(ads,udpbuf,r,serv,0,*now); |
656b2da9 |
428 | } |
37e28fde |
429 | } |
3e2e5fab |
430 | r= 0; |
431 | xit: |
28de6442 |
432 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
433 | return r; |
656b2da9 |
434 | } |
656b2da9 |
435 | |
620c146d |
436 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
656b2da9 |
437 | int r; |
620c146d |
438 | |
28de6442 |
439 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
440 | |
620c146d |
441 | switch (ads->tcpstate) { |
442 | case server_disconnected: |
fb901bf5 |
443 | case server_broken: |
620c146d |
444 | break; |
445 | case server_connecting: |
446 | if (fd != ads->tcpsocket) break; |
447 | assert(ads->tcprecv.used==0); |
70ad7a2a |
448 | assert(ads->tcprecv_skip==0); |
620c146d |
449 | for (;;) { |
3e2e5fab |
450 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; } |
620c146d |
451 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
452 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
453 | tcp_connected(ads,*now); |
3e2e5fab |
454 | r= 0; goto xit; |
620c146d |
455 | } |
456 | if (r>0) { |
457 | adns__tcp_broken(ads,"connect/read","sent data before first request"); |
3e2e5fab |
458 | r= 0; goto xit; |
620c146d |
459 | } |
460 | if (errno==EINTR) continue; |
3e2e5fab |
461 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
462 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
3e2e5fab |
463 | r= 0; goto xit; |
620c146d |
464 | } /* not reached */ |
465 | case server_ok: |
fb901bf5 |
466 | if (fd != ads->tcpsocket) break; |
467 | while (ads->tcpsend.used) { |
620c146d |
468 | adns__sigpipe_protect(ads); |
469 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
470 | adns__sigpipe_unprotect(ads); |
471 | if (r<0) { |
472 | if (errno==EINTR) continue; |
3e2e5fab |
473 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
474 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
475 | adns__tcp_broken(ads,"write",strerror(errno)); |
3e2e5fab |
476 | r= 0; goto xit; |
620c146d |
477 | } else if (r>0) { |
478 | ads->tcpsend.used -= r; |
479 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
480 | } |
fb901bf5 |
481 | } |
482 | r= 0; |
483 | goto xit; |
620c146d |
484 | default: |
485 | abort(); |
486 | } |
3e2e5fab |
487 | r= 0; |
488 | xit: |
28de6442 |
489 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
490 | return r; |
620c146d |
491 | } |
492 | |
609133ee |
493 | int adns_processexceptional(adns_state ads, int fd, |
494 | const struct timeval *now) { |
28de6442 |
495 | adns__consistency(ads,0,cc_entex); |
620c146d |
496 | switch (ads->tcpstate) { |
497 | case server_disconnected: |
fb901bf5 |
498 | case server_broken: |
620c146d |
499 | break; |
500 | case server_connecting: |
501 | case server_ok: |
502 | if (fd != ads->tcpsocket) break; |
503 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); |
3e2e5fab |
504 | break; |
620c146d |
505 | default: |
506 | abort(); |
507 | } |
28de6442 |
508 | adns__consistency(ads,0,cc_entex); |
620c146d |
509 | return 0; |
510 | } |
37e28fde |
511 | |
620c146d |
512 | static void fd_event(adns_state ads, int fd, |
513 | int revent, int pollflag, |
514 | int maxfd, const fd_set *fds, |
609133ee |
515 | int (*func)(adns_state, int fd, |
516 | const struct timeval *now), |
620c146d |
517 | struct timeval now, int *r_r) { |
656b2da9 |
518 | int r; |
620c146d |
519 | |
520 | if (!(revent & pollflag)) return; |
521 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; |
522 | r= func(ads,fd,&now); |
523 | if (r) { |
524 | if (r_r) { |
525 | *r_r= r; |
526 | } else { |
609133ee |
527 | adns__diag(ads,-1,0,"process fd failed after select:" |
528 | " %s",strerror(errno)); |
620c146d |
529 | adns_globalsystemfailure(ads); |
530 | } |
531 | } |
532 | } |
533 | |
534 | void adns__fdevents(adns_state ads, |
535 | const struct pollfd *pollfds, int npollfds, |
536 | int maxfd, const fd_set *readfds, |
537 | const fd_set *writefds, const fd_set *exceptfds, |
538 | struct timeval now, int *r_r) { |
539 | int i, fd, revents; |
540 | |
541 | for (i=0; i<npollfds; i++) { |
542 | fd= pollfds[i].fd; |
543 | if (fd >= maxfd) maxfd= fd+1; |
544 | revents= pollfds[i].revents; |
609133ee |
545 | #define EV(pollfl,fds,how) \ |
546 | fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r) |
547 | EV( POLLIN, readfds, readable ); |
548 | EV( POLLOUT, writefds, writeable ); |
549 | EV( POLLPRI, exceptfds, exceptional ); |
550 | #undef EV |
620c146d |
551 | } |
552 | } |
37e28fde |
553 | |
620c146d |
554 | /* Wrappers for select(2). */ |
555 | |
556 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, |
557 | fd_set *writefds_io, fd_set *exceptfds_io, |
558 | struct timeval **tv_mod, struct timeval *tv_tobuf, |
559 | const struct timeval *now) { |
560 | struct timeval tv_nowbuf; |
561 | struct pollfd pollfds[MAX_POLLFDS]; |
562 | int i, fd, maxfd, npollfds; |
563 | |
28de6442 |
564 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
565 | |
620c146d |
566 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
567 | /* The caller is planning to sleep. */ |
568 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
26cc07a3 |
569 | if (!now) { inter_immed(tv_mod,tv_tobuf); goto xit; } |
6c68a593 |
570 | adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now); |
620c146d |
571 | } |
572 | |
573 | npollfds= adns__pollfds(ads,pollfds); |
574 | maxfd= *maxfd_io; |
575 | for (i=0; i<npollfds; i++) { |
576 | fd= pollfds[i].fd; |
577 | if (fd >= maxfd) maxfd= fd+1; |
578 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); |
579 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); |
580 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); |
581 | } |
582 | *maxfd_io= maxfd; |
3e2e5fab |
583 | |
584 | xit: |
28de6442 |
585 | adns__consistency(ads,0,cc_entex); |
620c146d |
586 | } |
587 | |
588 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
589 | const fd_set *writefds, const fd_set *exceptfds, |
590 | const struct timeval *now) { |
fc6a52ae |
591 | struct timeval tv_buf; |
620c146d |
592 | struct pollfd pollfds[MAX_POLLFDS]; |
fc6a52ae |
593 | int npollfds, i; |
620c146d |
594 | |
28de6442 |
595 | adns__consistency(ads,0,cc_entex); |
fc6a52ae |
596 | adns__must_gettimeofday(ads,&now,&tv_buf); |
3e2e5fab |
597 | if (!now) goto xit; |
620c146d |
598 | adns_processtimeouts(ads,now); |
599 | |
600 | npollfds= adns__pollfds(ads,pollfds); |
fc6a52ae |
601 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
620c146d |
602 | adns__fdevents(ads, |
603 | pollfds,npollfds, |
604 | maxfd,readfds,writefds,exceptfds, |
605 | *now, 0); |
3e2e5fab |
606 | xit: |
28de6442 |
607 | adns__consistency(ads,0,cc_entex); |
620c146d |
608 | } |
609 | |
610 | /* General helpful functions. */ |
611 | |
612 | void adns_globalsystemfailure(adns_state ads) { |
28de6442 |
613 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
614 | |
f7f83b4a |
615 | while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail); |
616 | while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail); |
620c146d |
617 | |
618 | switch (ads->tcpstate) { |
619 | case server_connecting: |
620 | case server_ok: |
f7f83b4a |
621 | adns__tcp_broken(ads,0,0); |
620c146d |
622 | break; |
623 | case server_disconnected: |
fb901bf5 |
624 | case server_broken: |
620c146d |
625 | break; |
626 | default: |
627 | abort(); |
628 | } |
28de6442 |
629 | adns__consistency(ads,0,cc_entex); |
656b2da9 |
630 | } |
631 | |
620c146d |
632 | int adns_processany(adns_state ads) { |
aedf10f2 |
633 | int r, i; |
620c146d |
634 | struct timeval now; |
635 | struct pollfd pollfds[MAX_POLLFDS]; |
636 | int npollfds; |
637 | |
28de6442 |
638 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
639 | |
620c146d |
640 | r= gettimeofday(&now,0); |
641 | if (!r) adns_processtimeouts(ads,&now); |
642 | |
25913ee2 |
643 | /* We just use adns__fdevents to loop over the fd's trying them. |
644 | * This seems more sensible than calling select, since we're most |
645 | * likely just to want to do a read on one or two fds anyway. |
646 | */ |
620c146d |
647 | npollfds= adns__pollfds(ads,pollfds); |
1ed3dba4 |
648 | for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events & ~POLLPRI; |
620c146d |
649 | adns__fdevents(ads, |
650 | pollfds,npollfds, |
651 | 0,0,0,0, |
652 | now,&r); |
3e2e5fab |
653 | |
28de6442 |
654 | adns__consistency(ads,0,cc_entex); |
c118a725 |
655 | return 0; |
620c146d |
656 | } |
ddfda861 |
657 | |
4353a5c4 |
658 | void adns__autosys(adns_state ads, struct timeval now) { |
ddfda861 |
659 | if (ads->iflags & adns_if_noautosys) return; |
620c146d |
660 | adns_processany(ads); |
ddfda861 |
661 | } |
662 | |
940356bd |
663 | int adns__internal_check(adns_state ads, |
664 | adns_query *query_io, |
665 | adns_answer **answer, |
666 | void **context_r) { |
656b2da9 |
667 | adns_query qu; |
668 | |
669 | qu= *query_io; |
670 | if (!qu) { |
4ae90a83 |
671 | if (ads->output.head) { |
672 | qu= ads->output.head; |
f7f83b4a |
673 | } else if (ads->udpw.head || ads->tcpw.head) { |
4ae90a83 |
674 | return EAGAIN; |
675 | } else { |
676 | return ESRCH; |
677 | } |
656b2da9 |
678 | } else { |
226c5eef |
679 | if (qu->id>=0) return EAGAIN; |
656b2da9 |
680 | } |
681 | LIST_UNLINK(ads->output,qu); |
8e5b0abb |
682 | *answer= qu->answer; |
a6536d8b |
683 | if (context_r) *context_r= qu->ctx.ext; |
8ce38e76 |
684 | *query_io= qu; |
656b2da9 |
685 | free(qu); |
686 | return 0; |
687 | } |
688 | |
689 | int adns_wait(adns_state ads, |
690 | adns_query *query_io, |
691 | adns_answer **answer_r, |
692 | void **context_r) { |
620c146d |
693 | int r, maxfd, rsel; |
656b2da9 |
694 | fd_set readfds, writefds, exceptfds; |
26cc07a3 |
695 | struct timeval tvbuf, *tvp; |
656b2da9 |
696 | |
28de6442 |
697 | adns__consistency(ads,*query_io,cc_entex); |
656b2da9 |
698 | for (;;) { |
940356bd |
699 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
226c5eef |
700 | if (r != EAGAIN) break; |
656b2da9 |
701 | maxfd= 0; tvp= 0; |
37e28fde |
702 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
620c146d |
703 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
4fad263d |
704 | assert(tvp); |
656b2da9 |
705 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
88372443 |
706 | if (rsel==-1) { |
620c146d |
707 | if (errno == EINTR) { |
3e2e5fab |
708 | if (ads->iflags & adns_if_eintr) { r= EINTR; break; } |
620c146d |
709 | } else { |
710 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); |
711 | adns_globalsystemfailure(ads); |
712 | } |
713 | } else { |
714 | assert(rsel >= 0); |
715 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); |
88372443 |
716 | } |
656b2da9 |
717 | } |
28de6442 |
718 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
719 | return r; |
656b2da9 |
720 | } |
721 | |
722 | int adns_check(adns_state ads, |
723 | adns_query *query_io, |
724 | adns_answer **answer_r, |
725 | void **context_r) { |
4353a5c4 |
726 | struct timeval now; |
727 | int r; |
728 | |
28de6442 |
729 | adns__consistency(ads,*query_io,cc_entex); |
620c146d |
730 | r= gettimeofday(&now,0); |
731 | if (!r) adns__autosys(ads,now); |
3e2e5fab |
732 | |
940356bd |
733 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
28de6442 |
734 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
735 | return r; |
656b2da9 |
736 | } |