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