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 | /* |
ae8cc977 |
8 | * This file is part of adns, which is |
9 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
10 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
11 | * Copyright (C) 1991 Massachusetts Institute of Technology |
12 | * (See the file INSTALL for full details.) |
e576be50 |
13 | * |
14 | * This program is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU General Public License as published by |
16 | * the Free Software Foundation; either version 2, or (at your option) |
17 | * any later version. |
18 | * |
19 | * This program is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU General Public License |
25 | * along with this program; if not, write to the Free Software Foundation, |
26 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
27 | */ |
656b2da9 |
28 | |
4353a5c4 |
29 | #include <errno.h> |
30 | #include <stdlib.h> |
0f091044 |
31 | #include <unistd.h> |
4353a5c4 |
32 | |
0f091044 |
33 | #include <sys/types.h> |
34 | #include <sys/time.h> |
4353a5c4 |
35 | #include <netdb.h> |
eec1d9c8 |
36 | #include <sys/socket.h> |
37 | #include <netinet/in.h> |
4353a5c4 |
38 | #include <arpa/inet.h> |
39 | |
40 | #include "internal.h" |
2953d358 |
41 | #include "tvarith.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; |
fb901bf5 |
56 | adns_query qu; |
8402e34c |
57 | |
58 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); |
ddfda861 |
59 | serv= ads->tcpserver; |
f7f83b4a |
60 | if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why); |
61 | |
fb901bf5 |
62 | if (ads->tcpstate == server_connecting) { |
63 | /* Counts as a retry for all the queries waiting for TCP. */ |
64 | for (qu= ads->tcpw.head; qu; qu= qu->next) |
65 | qu->retries++; |
66 | } |
67 | |
f7f83b4a |
68 | tcp_close(ads); |
69 | ads->tcpstate= server_broken; |
70 | ads->tcpserver= (serv+1)%ads->nservers; |
8402e34c |
71 | } |
72 | |
ddfda861 |
73 | static void tcp_connected(adns_state ads, struct timeval now) { |
4353a5c4 |
74 | adns_query qu, nqu; |
75 | |
68442019 |
76 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
4353a5c4 |
77 | ads->tcpstate= server_ok; |
f7f83b4a |
78 | for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) { |
ddfda861 |
79 | nqu= qu->next; |
f7f83b4a |
80 | assert(qu->state == query_tcpw); |
81 | adns__querysend_tcp(qu,now); |
ddfda861 |
82 | } |
83 | } |
84 | |
237ce710 |
85 | static void tcp_broken_events(adns_state ads) { |
86 | adns_query qu, nqu; |
87 | |
88 | assert(ads->tcpstate == server_broken); |
89 | for (qu= ads->tcpw.head; qu; qu= nqu) { |
90 | nqu= qu->next; |
91 | assert(qu->state == query_tcpw); |
92 | if (qu->retries > ads->nservers) { |
93 | LIST_UNLINK(ads->tcpw,qu); |
94 | adns__query_fail(qu,adns_s_allservfail); |
95 | } |
96 | } |
97 | ads->tcpstate= server_disconnected; |
98 | } |
99 | |
ddfda861 |
100 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
8402e34c |
101 | int r, fd, tries; |
4353a5c4 |
102 | struct sockaddr_in addr; |
103 | struct protoent *proto; |
8402e34c |
104 | |
105 | for (tries=0; tries<ads->nservers; tries++) { |
f7f83b4a |
106 | switch (ads->tcpstate) { |
107 | case server_connecting: |
108 | case server_ok: |
109 | case server_broken: |
110 | return; |
111 | case server_disconnected: |
112 | break; |
113 | default: |
114 | abort(); |
115 | } |
116 | |
4353a5c4 |
117 | assert(!ads->tcpsend.used); |
118 | assert(!ads->tcprecv.used); |
70ad7a2a |
119 | assert(!ads->tcprecv_skip); |
8402e34c |
120 | |
121 | proto= getprotobyname("tcp"); |
609133ee |
122 | if (!proto) { |
123 | adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); |
124 | return; |
125 | } |
8402e34c |
126 | fd= socket(AF_INET,SOCK_STREAM,proto->p_proto); |
4353a5c4 |
127 | if (fd<0) { |
68442019 |
128 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
4353a5c4 |
129 | return; |
130 | } |
131 | r= adns__setnonblock(ads,fd); |
132 | if (r) { |
609133ee |
133 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking:" |
134 | " %s",strerror(r)); |
4353a5c4 |
135 | close(fd); |
136 | return; |
137 | } |
8402e34c |
138 | memset(&addr,0,sizeof(addr)); |
139 | addr.sin_family= AF_INET; |
98a3f706 |
140 | addr.sin_port= htons(DNS_PORT); |
8402e34c |
141 | addr.sin_addr= ads->servers[ads->tcpserver].addr; |
eec1d9c8 |
142 | r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr)); |
8402e34c |
143 | ads->tcpsocket= fd; |
144 | ads->tcpstate= server_connecting; |
f7f83b4a |
145 | if (r==0) { tcp_connected(ads,now); return; } |
146 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) { |
147 | ads->tcptimeout= now; |
148 | timevaladd(&ads->tcptimeout,TCPCONNMS); |
149 | return; |
150 | } |
ddfda861 |
151 | adns__tcp_broken(ads,"connect",strerror(errno)); |
237ce710 |
152 | tcp_broken_events(ads); |
8402e34c |
153 | } |
154 | } |
155 | |
620c146d |
156 | /* Timeout handling functions. */ |
157 | |
158 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
159 | struct timeval *tv_buf) { |
160 | const struct timeval *now; |
161 | int r; |
162 | |
163 | now= *now_io; |
164 | if (now) return; |
165 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } |
166 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); |
167 | adns_globalsystemfailure(ads); |
168 | return; |
169 | } |
4353a5c4 |
170 | |
4fad263d |
171 | static void inter_immed(struct timeval **tv_io, struct timeval *tvbuf) { |
172 | struct timeval *rbuf; |
173 | |
174 | if (!tv_io) return; |
175 | |
176 | rbuf= *tv_io; |
177 | if (!rbuf) { *tv_io= rbuf= tvbuf; } |
178 | |
179 | timerclear(rbuf); |
180 | } |
181 | |
4353a5c4 |
182 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
183 | struct timeval maxto) { |
184 | struct timeval *rbuf; |
185 | |
186 | if (!tv_io) return; |
187 | rbuf= *tv_io; |
94436798 |
188 | if (!rbuf) { |
189 | *tvbuf= maxto; *tv_io= tvbuf; |
190 | } else { |
191 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
192 | } |
ffbda80c |
193 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
194 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ |
4353a5c4 |
195 | } |
196 | |
197 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
198 | struct timeval now, struct timeval maxtime) { |
f7f83b4a |
199 | /* tv_io may be 0 */ |
4353a5c4 |
200 | ldiv_t dr; |
201 | |
ffbda80c |
202 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
203 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ |
4353a5c4 |
204 | if (!tv_io) return; |
94436798 |
205 | maxtime.tv_sec -= (now.tv_sec+2); |
206 | maxtime.tv_usec -= (now.tv_usec-2000000); |
207 | dr= ldiv(maxtime.tv_usec,1000000); |
4353a5c4 |
208 | maxtime.tv_sec += dr.quot; |
94436798 |
209 | maxtime.tv_usec -= dr.quot*1000000; |
210 | if (maxtime.tv_sec<0) timerclear(&maxtime); |
4353a5c4 |
211 | inter_maxto(tv_io,tvbuf,maxtime); |
212 | } |
213 | |
f7f83b4a |
214 | static void timeouts_queue(adns_state ads, int act, |
215 | struct timeval **tv_io, struct timeval *tvbuf, |
216 | struct timeval now, struct query_queue *queue) { |
4353a5c4 |
217 | adns_query qu, nqu; |
f7f83b4a |
218 | |
219 | for (qu= queue->head; qu; qu= nqu) { |
4353a5c4 |
220 | nqu= qu->next; |
d855b532 |
221 | if (!timercmp(&now,&qu->timeout,>)) { |
620c146d |
222 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
223 | } else { |
4fad263d |
224 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a |
225 | LIST_UNLINK(*queue,qu); |
d8c062fa |
226 | if (qu->state != query_tosend) { |
3955725c |
227 | adns__query_fail(qu,adns_s_timeout); |
4353a5c4 |
228 | } else { |
d8c062fa |
229 | adns__query_send(qu,now); |
4353a5c4 |
230 | } |
f7f83b4a |
231 | nqu= queue->head; |
4353a5c4 |
232 | } |
233 | } |
f7f83b4a |
234 | } |
235 | |
236 | static void tcp_events(adns_state ads, int act, |
237 | struct timeval **tv_io, struct timeval *tvbuf, |
238 | struct timeval now) { |
f7f83b4a |
239 | for (;;) { |
240 | switch (ads->tcpstate) { |
241 | case server_broken: |
4fad263d |
242 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
237ce710 |
243 | tcp_broken_events(ads); |
f7f83b4a |
244 | case server_disconnected: /* fall through */ |
245 | if (!ads->tcpw.head) return; |
4fad263d |
246 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a |
247 | adns__tcp_tryconnect(ads,now); |
248 | break; |
249 | case server_ok: |
250 | if (ads->tcpw.head) return; |
251 | if (!ads->tcptimeout.tv_sec) { |
252 | assert(!ads->tcptimeout.tv_usec); |
253 | ads->tcptimeout= now; |
254 | timevaladd(&ads->tcptimeout,TCPIDLEMS); |
255 | } |
256 | case server_connecting: /* fall through */ |
4fad263d |
257 | if (!act || !timercmp(&now,&ads->tcptimeout,>)) { |
f7f83b4a |
258 | inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout); |
259 | return; |
260 | } { |
261 | /* TCP timeout has happened */ |
262 | switch (ads->tcpstate) { |
263 | case server_connecting: /* failed to connect */ |
264 | adns__tcp_broken(ads,"unable to make connection","timed out"); |
265 | break; |
266 | case server_ok: /* idle timeout */ |
267 | tcp_close(ads); |
268 | ads->tcpstate= server_disconnected; |
269 | return; |
270 | default: |
271 | abort(); |
272 | } |
273 | } |
274 | break; |
275 | default: |
276 | abort(); |
277 | } |
278 | } |
4fad263d |
279 | return; |
f7f83b4a |
280 | } |
281 | |
282 | void adns__timeouts(adns_state ads, int act, |
283 | struct timeval **tv_io, struct timeval *tvbuf, |
284 | struct timeval now) { |
285 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw); |
286 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw); |
287 | tcp_events(ads,act,tv_io,tvbuf,now); |
288 | } |
94436798 |
289 | |
620c146d |
290 | void adns_firsttimeout(adns_state ads, |
291 | struct timeval **tv_io, struct timeval *tvbuf, |
292 | struct timeval now) { |
28de6442 |
293 | adns__consistency(ads,0,cc_entex); |
620c146d |
294 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
28de6442 |
295 | adns__consistency(ads,0,cc_entex); |
620c146d |
296 | } |
297 | |
298 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { |
299 | struct timeval tv_buf; |
300 | |
28de6442 |
301 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
302 | adns__must_gettimeofday(ads,&now,&tv_buf); |
303 | if (now) adns__timeouts(ads, 1, 0,0, *now); |
28de6442 |
304 | adns__consistency(ads,0,cc_entex); |
a8768e80 |
305 | } |
306 | |
620c146d |
307 | /* fd handling functions. These are the top-level of the real work of |
308 | * reception and often transmission. |
309 | */ |
310 | |
311 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { |
312 | /* Returns the number of entries filled in. Always zeroes revents. */ |
313 | |
314 | assert(MAX_POLLFDS==2); |
a8768e80 |
315 | |
620c146d |
316 | pollfds_buf[0].fd= ads->udpsocket; |
317 | pollfds_buf[0].events= POLLIN; |
318 | pollfds_buf[0].revents= 0; |
4353a5c4 |
319 | |
320 | switch (ads->tcpstate) { |
321 | case server_disconnected: |
6c68a593 |
322 | case server_broken: |
620c146d |
323 | return 1; |
4353a5c4 |
324 | case server_connecting: |
620c146d |
325 | pollfds_buf[1].events= POLLOUT; |
4353a5c4 |
326 | break; |
327 | case server_ok: |
609133ee |
328 | pollfds_buf[1].events= |
329 | ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI; |
e062dcae |
330 | break; |
4353a5c4 |
331 | default: |
332 | abort(); |
333 | } |
620c146d |
334 | pollfds_buf[1].fd= ads->tcpsocket; |
620c146d |
335 | return 2; |
4353a5c4 |
336 | } |
337 | |
620c146d |
338 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
70ad7a2a |
339 | int want, dgramlen, r, udpaddrlen, serv, old_skip; |
98a3f706 |
340 | byte udpbuf[DNS_MAXUDP]; |
37e28fde |
341 | struct sockaddr_in udpaddr; |
620c146d |
342 | |
28de6442 |
343 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
344 | |
ddfda861 |
345 | switch (ads->tcpstate) { |
346 | case server_disconnected: |
fb901bf5 |
347 | case server_broken: |
ddfda861 |
348 | case server_connecting: |
ddfda861 |
349 | break; |
350 | case server_ok: |
620c146d |
351 | if (fd != ads->tcpsocket) break; |
70ad7a2a |
352 | assert(!ads->tcprecv_skip); |
428bd682 |
353 | do { |
70ad7a2a |
354 | if (ads->tcprecv.used >= ads->tcprecv_skip+2) { |
355 | dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) | |
356 | ads->tcprecv.buf[ads->tcprecv_skip+1]); |
357 | if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) { |
358 | old_skip= ads->tcprecv_skip; |
359 | ads->tcprecv_skip += 2+dgramlen; |
360 | adns__procdgram(ads, ads->tcprecv.buf+old_skip+2, |
361 | dgramlen, ads->tcpserver, 1,*now); |
362 | continue; |
656b2da9 |
363 | } else { |
70ad7a2a |
364 | want= 2+dgramlen; |
656b2da9 |
365 | } |
70ad7a2a |
366 | } else { |
367 | want= 2; |
656b2da9 |
368 | } |
70ad7a2a |
369 | ads->tcprecv.used -= ads->tcprecv_skip; |
609133ee |
370 | memmove(ads->tcprecv.buf, ads->tcprecv.buf+ads->tcprecv_skip, |
371 | ads->tcprecv.used); |
70ad7a2a |
372 | ads->tcprecv_skip= 0; |
3e2e5fab |
373 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; } |
620c146d |
374 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
375 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; |
376 | r= read(ads->tcpsocket, |
377 | ads->tcprecv.buf+ads->tcprecv.used, |
378 | ads->tcprecv.avail-ads->tcprecv.used); |
379 | if (r>0) { |
380 | ads->tcprecv.used+= r; |
381 | } else { |
382 | if (r) { |
3e2e5fab |
383 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
384 | if (errno==EINTR) continue; |
3e2e5fab |
385 | if (errno_resources(errno)) { r= errno; goto xit; } |
656b2da9 |
386 | } |
620c146d |
387 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
656b2da9 |
388 | } |
428bd682 |
389 | } while (ads->tcpstate == server_ok); |
390 | r= 0; goto xit; |
ddfda861 |
391 | default: |
392 | abort(); |
656b2da9 |
393 | } |
620c146d |
394 | if (fd == ads->udpsocket) { |
37e28fde |
395 | for (;;) { |
396 | udpaddrlen= sizeof(udpaddr); |
eec1d9c8 |
397 | r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0, |
398 | (struct sockaddr*)&udpaddr,&udpaddrlen); |
37e28fde |
399 | if (r<0) { |
3e2e5fab |
400 | if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; } |
620c146d |
401 | if (errno == EINTR) continue; |
3e2e5fab |
402 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
403 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); |
3e2e5fab |
404 | r= 0; goto xit; |
37e28fde |
405 | } |
406 | if (udpaddrlen != sizeof(udpaddr)) { |
68442019 |
407 | adns__diag(ads,-1,0,"datagram received with wrong address length %d" |
5a0be244 |
408 | " (expected %lu)", udpaddrlen, |
409 | (unsigned long)sizeof(udpaddr)); |
37e28fde |
410 | continue; |
411 | } |
412 | if (udpaddr.sin_family != AF_INET) { |
68442019 |
413 | adns__diag(ads,-1,0,"datagram received with wrong protocol family" |
4353a5c4 |
414 | " %u (expected %u)",udpaddr.sin_family,AF_INET); |
37e28fde |
415 | continue; |
416 | } |
98a3f706 |
417 | if (ntohs(udpaddr.sin_port) != DNS_PORT) { |
609133ee |
418 | adns__diag(ads,-1,0,"datagram received from wrong port" |
419 | " %u (expected %u)", ntohs(udpaddr.sin_port),DNS_PORT); |
37e28fde |
420 | continue; |
421 | } |
422 | for (serv= 0; |
423 | serv < ads->nservers && |
424 | ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; |
425 | serv++); |
426 | if (serv >= ads->nservers) { |
68442019 |
427 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", |
4353a5c4 |
428 | inet_ntoa(udpaddr.sin_addr)); |
37e28fde |
429 | continue; |
430 | } |
ebf4877a |
431 | adns__procdgram(ads,udpbuf,r,serv,0,*now); |
656b2da9 |
432 | } |
37e28fde |
433 | } |
3e2e5fab |
434 | r= 0; |
435 | xit: |
28de6442 |
436 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
437 | return r; |
656b2da9 |
438 | } |
656b2da9 |
439 | |
620c146d |
440 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
656b2da9 |
441 | int r; |
620c146d |
442 | |
28de6442 |
443 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
444 | |
620c146d |
445 | switch (ads->tcpstate) { |
446 | case server_disconnected: |
fb901bf5 |
447 | case server_broken: |
620c146d |
448 | break; |
449 | case server_connecting: |
450 | if (fd != ads->tcpsocket) break; |
451 | assert(ads->tcprecv.used==0); |
70ad7a2a |
452 | assert(ads->tcprecv_skip==0); |
620c146d |
453 | for (;;) { |
3e2e5fab |
454 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; } |
620c146d |
455 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
456 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
457 | tcp_connected(ads,*now); |
3e2e5fab |
458 | r= 0; goto xit; |
620c146d |
459 | } |
460 | if (r>0) { |
461 | adns__tcp_broken(ads,"connect/read","sent data before first request"); |
3e2e5fab |
462 | r= 0; goto xit; |
620c146d |
463 | } |
464 | if (errno==EINTR) continue; |
3e2e5fab |
465 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
466 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
3e2e5fab |
467 | r= 0; goto xit; |
620c146d |
468 | } /* not reached */ |
469 | case server_ok: |
fb901bf5 |
470 | if (fd != ads->tcpsocket) break; |
471 | while (ads->tcpsend.used) { |
620c146d |
472 | adns__sigpipe_protect(ads); |
473 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
474 | adns__sigpipe_unprotect(ads); |
475 | if (r<0) { |
476 | if (errno==EINTR) continue; |
3e2e5fab |
477 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
478 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d |
479 | adns__tcp_broken(ads,"write",strerror(errno)); |
3e2e5fab |
480 | r= 0; goto xit; |
620c146d |
481 | } else if (r>0) { |
482 | ads->tcpsend.used -= r; |
483 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
484 | } |
fb901bf5 |
485 | } |
486 | r= 0; |
487 | goto xit; |
620c146d |
488 | default: |
489 | abort(); |
490 | } |
3e2e5fab |
491 | r= 0; |
492 | xit: |
28de6442 |
493 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
494 | return r; |
620c146d |
495 | } |
496 | |
609133ee |
497 | int adns_processexceptional(adns_state ads, int fd, |
498 | const struct timeval *now) { |
28de6442 |
499 | adns__consistency(ads,0,cc_entex); |
620c146d |
500 | switch (ads->tcpstate) { |
501 | case server_disconnected: |
fb901bf5 |
502 | case server_broken: |
620c146d |
503 | break; |
504 | case server_connecting: |
505 | case server_ok: |
506 | if (fd != ads->tcpsocket) break; |
507 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); |
3e2e5fab |
508 | break; |
620c146d |
509 | default: |
510 | abort(); |
511 | } |
28de6442 |
512 | adns__consistency(ads,0,cc_entex); |
620c146d |
513 | return 0; |
514 | } |
37e28fde |
515 | |
620c146d |
516 | static void fd_event(adns_state ads, int fd, |
517 | int revent, int pollflag, |
518 | int maxfd, const fd_set *fds, |
609133ee |
519 | int (*func)(adns_state, int fd, |
520 | const struct timeval *now), |
620c146d |
521 | struct timeval now, int *r_r) { |
656b2da9 |
522 | int r; |
620c146d |
523 | |
524 | if (!(revent & pollflag)) return; |
525 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; |
526 | r= func(ads,fd,&now); |
527 | if (r) { |
528 | if (r_r) { |
529 | *r_r= r; |
530 | } else { |
609133ee |
531 | adns__diag(ads,-1,0,"process fd failed after select:" |
532 | " %s",strerror(errno)); |
620c146d |
533 | adns_globalsystemfailure(ads); |
534 | } |
535 | } |
536 | } |
537 | |
538 | void adns__fdevents(adns_state ads, |
539 | const struct pollfd *pollfds, int npollfds, |
540 | int maxfd, const fd_set *readfds, |
541 | const fd_set *writefds, const fd_set *exceptfds, |
542 | struct timeval now, int *r_r) { |
543 | int i, fd, revents; |
544 | |
545 | for (i=0; i<npollfds; i++) { |
546 | fd= pollfds[i].fd; |
547 | if (fd >= maxfd) maxfd= fd+1; |
548 | revents= pollfds[i].revents; |
609133ee |
549 | #define EV(pollfl,fds,how) \ |
550 | fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r) |
551 | EV( POLLIN, readfds, readable ); |
552 | EV( POLLOUT, writefds, writeable ); |
553 | EV( POLLPRI, exceptfds, exceptional ); |
554 | #undef EV |
620c146d |
555 | } |
556 | } |
37e28fde |
557 | |
620c146d |
558 | /* Wrappers for select(2). */ |
559 | |
560 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, |
561 | fd_set *writefds_io, fd_set *exceptfds_io, |
562 | struct timeval **tv_mod, struct timeval *tv_tobuf, |
563 | const struct timeval *now) { |
564 | struct timeval tv_nowbuf; |
565 | struct pollfd pollfds[MAX_POLLFDS]; |
566 | int i, fd, maxfd, npollfds; |
567 | |
28de6442 |
568 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
569 | |
620c146d |
570 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
571 | /* The caller is planning to sleep. */ |
572 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
26cc07a3 |
573 | if (!now) { inter_immed(tv_mod,tv_tobuf); goto xit; } |
6c68a593 |
574 | adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now); |
620c146d |
575 | } |
576 | |
577 | npollfds= adns__pollfds(ads,pollfds); |
578 | maxfd= *maxfd_io; |
579 | for (i=0; i<npollfds; i++) { |
580 | fd= pollfds[i].fd; |
581 | if (fd >= maxfd) maxfd= fd+1; |
582 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); |
583 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); |
584 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); |
585 | } |
586 | *maxfd_io= maxfd; |
3e2e5fab |
587 | |
588 | xit: |
28de6442 |
589 | adns__consistency(ads,0,cc_entex); |
620c146d |
590 | } |
591 | |
592 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
593 | const fd_set *writefds, const fd_set *exceptfds, |
594 | const struct timeval *now) { |
fc6a52ae |
595 | struct timeval tv_buf; |
620c146d |
596 | struct pollfd pollfds[MAX_POLLFDS]; |
fc6a52ae |
597 | int npollfds, i; |
620c146d |
598 | |
28de6442 |
599 | adns__consistency(ads,0,cc_entex); |
fc6a52ae |
600 | adns__must_gettimeofday(ads,&now,&tv_buf); |
3e2e5fab |
601 | if (!now) goto xit; |
620c146d |
602 | adns_processtimeouts(ads,now); |
603 | |
604 | npollfds= adns__pollfds(ads,pollfds); |
fc6a52ae |
605 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
620c146d |
606 | adns__fdevents(ads, |
607 | pollfds,npollfds, |
608 | maxfd,readfds,writefds,exceptfds, |
609 | *now, 0); |
3e2e5fab |
610 | xit: |
28de6442 |
611 | adns__consistency(ads,0,cc_entex); |
620c146d |
612 | } |
613 | |
614 | /* General helpful functions. */ |
615 | |
616 | void adns_globalsystemfailure(adns_state ads) { |
28de6442 |
617 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
618 | |
f7f83b4a |
619 | while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail); |
620 | while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail); |
620c146d |
621 | |
622 | switch (ads->tcpstate) { |
623 | case server_connecting: |
624 | case server_ok: |
f7f83b4a |
625 | adns__tcp_broken(ads,0,0); |
620c146d |
626 | break; |
627 | case server_disconnected: |
fb901bf5 |
628 | case server_broken: |
620c146d |
629 | break; |
630 | default: |
631 | abort(); |
632 | } |
28de6442 |
633 | adns__consistency(ads,0,cc_entex); |
656b2da9 |
634 | } |
635 | |
620c146d |
636 | int adns_processany(adns_state ads) { |
aedf10f2 |
637 | int r, i; |
620c146d |
638 | struct timeval now; |
639 | struct pollfd pollfds[MAX_POLLFDS]; |
640 | int npollfds; |
641 | |
28de6442 |
642 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
643 | |
620c146d |
644 | r= gettimeofday(&now,0); |
645 | if (!r) adns_processtimeouts(ads,&now); |
646 | |
25913ee2 |
647 | /* We just use adns__fdevents to loop over the fd's trying them. |
648 | * This seems more sensible than calling select, since we're most |
649 | * likely just to want to do a read on one or two fds anyway. |
650 | */ |
620c146d |
651 | npollfds= adns__pollfds(ads,pollfds); |
1ed3dba4 |
652 | for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events & ~POLLPRI; |
620c146d |
653 | adns__fdevents(ads, |
654 | pollfds,npollfds, |
655 | 0,0,0,0, |
656 | now,&r); |
3e2e5fab |
657 | |
28de6442 |
658 | adns__consistency(ads,0,cc_entex); |
c118a725 |
659 | return 0; |
620c146d |
660 | } |
ddfda861 |
661 | |
4353a5c4 |
662 | void adns__autosys(adns_state ads, struct timeval now) { |
ddfda861 |
663 | if (ads->iflags & adns_if_noautosys) return; |
620c146d |
664 | adns_processany(ads); |
ddfda861 |
665 | } |
666 | |
940356bd |
667 | int adns__internal_check(adns_state ads, |
668 | adns_query *query_io, |
669 | adns_answer **answer, |
670 | void **context_r) { |
656b2da9 |
671 | adns_query qu; |
672 | |
673 | qu= *query_io; |
674 | if (!qu) { |
4ae90a83 |
675 | if (ads->output.head) { |
676 | qu= ads->output.head; |
f7f83b4a |
677 | } else if (ads->udpw.head || ads->tcpw.head) { |
4ae90a83 |
678 | return EAGAIN; |
679 | } else { |
680 | return ESRCH; |
681 | } |
656b2da9 |
682 | } else { |
226c5eef |
683 | if (qu->id>=0) return EAGAIN; |
656b2da9 |
684 | } |
685 | LIST_UNLINK(ads->output,qu); |
8e5b0abb |
686 | *answer= qu->answer; |
a6536d8b |
687 | if (context_r) *context_r= qu->ctx.ext; |
8ce38e76 |
688 | *query_io= qu; |
656b2da9 |
689 | free(qu); |
690 | return 0; |
691 | } |
692 | |
693 | int adns_wait(adns_state ads, |
694 | adns_query *query_io, |
695 | adns_answer **answer_r, |
696 | void **context_r) { |
620c146d |
697 | int r, maxfd, rsel; |
656b2da9 |
698 | fd_set readfds, writefds, exceptfds; |
26cc07a3 |
699 | struct timeval tvbuf, *tvp; |
656b2da9 |
700 | |
28de6442 |
701 | adns__consistency(ads,*query_io,cc_entex); |
656b2da9 |
702 | for (;;) { |
940356bd |
703 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
226c5eef |
704 | if (r != EAGAIN) break; |
656b2da9 |
705 | maxfd= 0; tvp= 0; |
37e28fde |
706 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
620c146d |
707 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
4fad263d |
708 | assert(tvp); |
656b2da9 |
709 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
88372443 |
710 | if (rsel==-1) { |
620c146d |
711 | if (errno == EINTR) { |
3e2e5fab |
712 | if (ads->iflags & adns_if_eintr) { r= EINTR; break; } |
620c146d |
713 | } else { |
714 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); |
715 | adns_globalsystemfailure(ads); |
716 | } |
717 | } else { |
718 | assert(rsel >= 0); |
719 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); |
88372443 |
720 | } |
656b2da9 |
721 | } |
28de6442 |
722 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
723 | return r; |
656b2da9 |
724 | } |
725 | |
726 | int adns_check(adns_state ads, |
727 | adns_query *query_io, |
728 | adns_answer **answer_r, |
729 | void **context_r) { |
4353a5c4 |
730 | struct timeval now; |
731 | int r; |
732 | |
28de6442 |
733 | adns__consistency(ads,*query_io,cc_entex); |
620c146d |
734 | r= gettimeofday(&now,0); |
735 | if (!r) adns__autosys(ads,now); |
3e2e5fab |
736 | |
940356bd |
737 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
28de6442 |
738 | adns__consistency(ads,0,cc_entex); |
3e2e5fab |
739 | return r; |
656b2da9 |
740 | } |