98db6da3 |
1 | /* |
2 | * event.c |
3 | * - event loop core |
4 | * - TCP connection management |
5 | * - user-visible check/wait and event-loop-related functions |
6 | */ |
7 | /* |
a79ac5ba |
8 | * This file is |
89435c42 |
9 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
a79ac5ba |
10 | * |
11 | * It is part of adns, which is |
89435c42 |
12 | * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> |
c6826df6 |
13 | * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at> |
98db6da3 |
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 | */ |
6f17710a |
29 | |
d05cc330 |
30 | #include <errno.h> |
31 | #include <stdlib.h> |
b6b3ac61 |
32 | #include <unistd.h> |
d05cc330 |
33 | |
b6b3ac61 |
34 | #include <sys/types.h> |
35 | #include <sys/time.h> |
d05cc330 |
36 | #include <netdb.h> |
29cf9c44 |
37 | #include <sys/socket.h> |
38 | #include <netinet/in.h> |
d05cc330 |
39 | #include <arpa/inet.h> |
40 | |
41 | #include "internal.h" |
83e1be2f |
42 | #include "tvarith.h" |
dfdbb32c |
43 | |
74c94831 |
44 | /* TCP connection management. */ |
45 | |
d0a057ac |
46 | static void tcp_close(adns_state ads) { |
74c94831 |
47 | int serv; |
48 | |
49 | serv= ads->tcpserver; |
50 | close(ads->tcpsocket); |
e70d5929 |
51 | ads->tcpsocket= -1; |
ab898cf4 |
52 | ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0; |
74c94831 |
53 | } |
6f17710a |
54 | |
71324651 |
55 | void adns__tcp_broken(adns_state ads, const char *what, const char *why) { |
56 | int serv; |
486ee6b1 |
57 | adns_query qu; |
71324651 |
58 | |
59 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); |
96e79df5 |
60 | serv= ads->tcpserver; |
d0a057ac |
61 | if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why); |
62 | |
486ee6b1 |
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 | |
d0a057ac |
69 | tcp_close(ads); |
70 | ads->tcpstate= server_broken; |
71 | ads->tcpserver= (serv+1)%ads->nservers; |
71324651 |
72 | } |
73 | |
96e79df5 |
74 | static void tcp_connected(adns_state ads, struct timeval now) { |
d05cc330 |
75 | adns_query qu, nqu; |
76 | |
ae41e040 |
77 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
d05cc330 |
78 | ads->tcpstate= server_ok; |
d0a057ac |
79 | for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) { |
96e79df5 |
80 | nqu= qu->next; |
d0a057ac |
81 | assert(qu->state == query_tcpw); |
82 | adns__querysend_tcp(qu,now); |
96e79df5 |
83 | } |
84 | } |
85 | |
e96ef6b0 |
86 | static void tcp_broken_events(adns_state ads) { |
87 | adns_query qu, nqu; |
88 | |
89 | assert(ads->tcpstate == server_broken); |
90 | for (qu= ads->tcpw.head; qu; qu= nqu) { |
91 | nqu= qu->next; |
92 | assert(qu->state == query_tcpw); |
93 | if (qu->retries > ads->nservers) { |
94 | LIST_UNLINK(ads->tcpw,qu); |
95 | adns__query_fail(qu,adns_s_allservfail); |
96 | } |
97 | } |
98 | ads->tcpstate= server_disconnected; |
99 | } |
100 | |
96e79df5 |
101 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
71324651 |
102 | int r, fd, tries; |
d05cc330 |
103 | struct sockaddr_in addr; |
104 | struct protoent *proto; |
71324651 |
105 | |
106 | for (tries=0; tries<ads->nservers; tries++) { |
d0a057ac |
107 | switch (ads->tcpstate) { |
108 | case server_connecting: |
109 | case server_ok: |
110 | case server_broken: |
111 | return; |
112 | case server_disconnected: |
113 | break; |
114 | default: |
115 | abort(); |
116 | } |
117 | |
d05cc330 |
118 | assert(!ads->tcpsend.used); |
119 | assert(!ads->tcprecv.used); |
ab898cf4 |
120 | assert(!ads->tcprecv_skip); |
71324651 |
121 | |
122 | proto= getprotobyname("tcp"); |
9c344a42 |
123 | if (!proto) { |
124 | adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); |
125 | return; |
126 | } |
71324651 |
127 | fd= socket(AF_INET,SOCK_STREAM,proto->p_proto); |
d05cc330 |
128 | if (fd<0) { |
ae41e040 |
129 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
d05cc330 |
130 | return; |
131 | } |
132 | r= adns__setnonblock(ads,fd); |
133 | if (r) { |
9c344a42 |
134 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking:" |
135 | " %s",strerror(r)); |
d05cc330 |
136 | close(fd); |
137 | return; |
138 | } |
71324651 |
139 | memset(&addr,0,sizeof(addr)); |
140 | addr.sin_family= AF_INET; |
5c596e4d |
141 | addr.sin_port= htons(DNS_PORT); |
71324651 |
142 | addr.sin_addr= ads->servers[ads->tcpserver].addr; |
29cf9c44 |
143 | r= connect(fd,(const struct sockaddr*)&addr,sizeof(addr)); |
71324651 |
144 | ads->tcpsocket= fd; |
145 | ads->tcpstate= server_connecting; |
d0a057ac |
146 | if (r==0) { tcp_connected(ads,now); return; } |
147 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) { |
148 | ads->tcptimeout= now; |
149 | timevaladd(&ads->tcptimeout,TCPCONNMS); |
150 | return; |
151 | } |
96e79df5 |
152 | adns__tcp_broken(ads,"connect",strerror(errno)); |
e96ef6b0 |
153 | tcp_broken_events(ads); |
71324651 |
154 | } |
155 | } |
156 | |
74c94831 |
157 | /* Timeout handling functions. */ |
158 | |
159 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, |
160 | struct timeval *tv_buf) { |
161 | const struct timeval *now; |
162 | int r; |
163 | |
164 | now= *now_io; |
165 | if (now) return; |
166 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } |
167 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); |
168 | adns_globalsystemfailure(ads); |
169 | return; |
170 | } |
d05cc330 |
171 | |
8744cce8 |
172 | static void inter_immed(struct timeval **tv_io, struct timeval *tvbuf) { |
173 | struct timeval *rbuf; |
174 | |
175 | if (!tv_io) return; |
176 | |
177 | rbuf= *tv_io; |
178 | if (!rbuf) { *tv_io= rbuf= tvbuf; } |
179 | |
180 | timerclear(rbuf); |
181 | } |
182 | |
d05cc330 |
183 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
184 | struct timeval maxto) { |
185 | struct timeval *rbuf; |
186 | |
187 | if (!tv_io) return; |
188 | rbuf= *tv_io; |
de8b18da |
189 | if (!rbuf) { |
190 | *tvbuf= maxto; *tv_io= tvbuf; |
191 | } else { |
192 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; |
193 | } |
cfdca685 |
194 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
195 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ |
d05cc330 |
196 | } |
197 | |
198 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, |
199 | struct timeval now, struct timeval maxtime) { |
d0a057ac |
200 | /* tv_io may be 0 */ |
d05cc330 |
201 | ldiv_t dr; |
202 | |
cfdca685 |
203 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
204 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ |
d05cc330 |
205 | if (!tv_io) return; |
de8b18da |
206 | maxtime.tv_sec -= (now.tv_sec+2); |
207 | maxtime.tv_usec -= (now.tv_usec-2000000); |
208 | dr= ldiv(maxtime.tv_usec,1000000); |
d05cc330 |
209 | maxtime.tv_sec += dr.quot; |
de8b18da |
210 | maxtime.tv_usec -= dr.quot*1000000; |
211 | if (maxtime.tv_sec<0) timerclear(&maxtime); |
d05cc330 |
212 | inter_maxto(tv_io,tvbuf,maxtime); |
213 | } |
214 | |
d0a057ac |
215 | static void timeouts_queue(adns_state ads, int act, |
216 | struct timeval **tv_io, struct timeval *tvbuf, |
217 | struct timeval now, struct query_queue *queue) { |
d05cc330 |
218 | adns_query qu, nqu; |
d0a057ac |
219 | |
220 | for (qu= queue->head; qu; qu= nqu) { |
d05cc330 |
221 | nqu= qu->next; |
7def4935 |
222 | if (!timercmp(&now,&qu->timeout,>)) { |
74c94831 |
223 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
224 | } else { |
8744cce8 |
225 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
d0a057ac |
226 | LIST_UNLINK(*queue,qu); |
24d52b13 |
227 | if (qu->state != query_tosend) { |
11c8bf9b |
228 | adns__query_fail(qu,adns_s_timeout); |
d05cc330 |
229 | } else { |
24d52b13 |
230 | adns__query_send(qu,now); |
d05cc330 |
231 | } |
d0a057ac |
232 | nqu= queue->head; |
d05cc330 |
233 | } |
234 | } |
d0a057ac |
235 | } |
236 | |
237 | static void tcp_events(adns_state ads, int act, |
238 | struct timeval **tv_io, struct timeval *tvbuf, |
239 | struct timeval now) { |
d0a057ac |
240 | for (;;) { |
241 | switch (ads->tcpstate) { |
242 | case server_broken: |
8744cce8 |
243 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
e96ef6b0 |
244 | tcp_broken_events(ads); |
d0a057ac |
245 | case server_disconnected: /* fall through */ |
246 | if (!ads->tcpw.head) return; |
8744cce8 |
247 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
d0a057ac |
248 | adns__tcp_tryconnect(ads,now); |
249 | break; |
250 | case server_ok: |
251 | if (ads->tcpw.head) return; |
252 | if (!ads->tcptimeout.tv_sec) { |
253 | assert(!ads->tcptimeout.tv_usec); |
254 | ads->tcptimeout= now; |
255 | timevaladd(&ads->tcptimeout,TCPIDLEMS); |
256 | } |
257 | case server_connecting: /* fall through */ |
8744cce8 |
258 | if (!act || !timercmp(&now,&ads->tcptimeout,>)) { |
d0a057ac |
259 | inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout); |
260 | return; |
261 | } { |
262 | /* TCP timeout has happened */ |
263 | switch (ads->tcpstate) { |
264 | case server_connecting: /* failed to connect */ |
265 | adns__tcp_broken(ads,"unable to make connection","timed out"); |
266 | break; |
267 | case server_ok: /* idle timeout */ |
268 | tcp_close(ads); |
269 | ads->tcpstate= server_disconnected; |
270 | return; |
271 | default: |
272 | abort(); |
273 | } |
274 | } |
275 | break; |
276 | default: |
277 | abort(); |
278 | } |
279 | } |
8744cce8 |
280 | return; |
d0a057ac |
281 | } |
282 | |
283 | void adns__timeouts(adns_state ads, int act, |
284 | struct timeval **tv_io, struct timeval *tvbuf, |
285 | struct timeval now) { |
286 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw); |
287 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw); |
288 | tcp_events(ads,act,tv_io,tvbuf,now); |
289 | } |
de8b18da |
290 | |
74c94831 |
291 | void adns_firsttimeout(adns_state ads, |
292 | struct timeval **tv_io, struct timeval *tvbuf, |
293 | struct timeval now) { |
2ac463bf |
294 | adns__consistency(ads,0,cc_entex); |
74c94831 |
295 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
2ac463bf |
296 | adns__consistency(ads,0,cc_entex); |
74c94831 |
297 | } |
298 | |
299 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { |
300 | struct timeval tv_buf; |
301 | |
2ac463bf |
302 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
303 | adns__must_gettimeofday(ads,&now,&tv_buf); |
304 | if (now) adns__timeouts(ads, 1, 0,0, *now); |
2ac463bf |
305 | adns__consistency(ads,0,cc_entex); |
74c94831 |
306 | } |
307 | |
308 | /* fd handling functions. These are the top-level of the real work of |
309 | * reception and often transmission. |
310 | */ |
311 | |
312 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { |
313 | /* Returns the number of entries filled in. Always zeroes revents. */ |
314 | |
315 | assert(MAX_POLLFDS==2); |
316 | |
317 | pollfds_buf[0].fd= ads->udpsocket; |
318 | pollfds_buf[0].events= POLLIN; |
319 | pollfds_buf[0].revents= 0; |
d05cc330 |
320 | |
321 | switch (ads->tcpstate) { |
322 | case server_disconnected: |
da0e3c0a |
323 | case server_broken: |
74c94831 |
324 | return 1; |
d05cc330 |
325 | case server_connecting: |
74c94831 |
326 | pollfds_buf[1].events= POLLOUT; |
d05cc330 |
327 | break; |
328 | case server_ok: |
9c344a42 |
329 | pollfds_buf[1].events= |
330 | ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI; |
f2ad23ee |
331 | break; |
d05cc330 |
332 | default: |
333 | abort(); |
334 | } |
74c94831 |
335 | pollfds_buf[1].fd= ads->tcpsocket; |
74c94831 |
336 | return 2; |
d05cc330 |
337 | } |
338 | |
74c94831 |
339 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
ab898cf4 |
340 | int want, dgramlen, r, udpaddrlen, serv, old_skip; |
5c596e4d |
341 | byte udpbuf[DNS_MAXUDP]; |
dfdbb32c |
342 | struct sockaddr_in udpaddr; |
74c94831 |
343 | |
2ac463bf |
344 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
345 | |
96e79df5 |
346 | switch (ads->tcpstate) { |
347 | case server_disconnected: |
486ee6b1 |
348 | case server_broken: |
96e79df5 |
349 | case server_connecting: |
96e79df5 |
350 | break; |
351 | case server_ok: |
74c94831 |
352 | if (fd != ads->tcpsocket) break; |
ab898cf4 |
353 | assert(!ads->tcprecv_skip); |
5c33fbf4 |
354 | do { |
ab898cf4 |
355 | if (ads->tcprecv.used >= ads->tcprecv_skip+2) { |
356 | dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) | |
357 | ads->tcprecv.buf[ads->tcprecv_skip+1]); |
358 | if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) { |
359 | old_skip= ads->tcprecv_skip; |
360 | ads->tcprecv_skip += 2+dgramlen; |
361 | adns__procdgram(ads, ads->tcprecv.buf+old_skip+2, |
362 | dgramlen, ads->tcpserver, 1,*now); |
363 | continue; |
6f17710a |
364 | } else { |
ab898cf4 |
365 | want= 2+dgramlen; |
6f17710a |
366 | } |
ab898cf4 |
367 | } else { |
368 | want= 2; |
6f17710a |
369 | } |
ab898cf4 |
370 | ads->tcprecv.used -= ads->tcprecv_skip; |
9c344a42 |
371 | memmove(ads->tcprecv.buf, ads->tcprecv.buf+ads->tcprecv_skip, |
372 | ads->tcprecv.used); |
ab898cf4 |
373 | ads->tcprecv_skip= 0; |
1389dc72 |
374 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; } |
74c94831 |
375 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
376 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; |
377 | r= read(ads->tcpsocket, |
378 | ads->tcprecv.buf+ads->tcprecv.used, |
379 | ads->tcprecv.avail-ads->tcprecv.used); |
380 | if (r>0) { |
381 | ads->tcprecv.used+= r; |
382 | } else { |
383 | if (r) { |
1389dc72 |
384 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
74c94831 |
385 | if (errno==EINTR) continue; |
1389dc72 |
386 | if (errno_resources(errno)) { r= errno; goto xit; } |
6f17710a |
387 | } |
74c94831 |
388 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
6f17710a |
389 | } |
5c33fbf4 |
390 | } while (ads->tcpstate == server_ok); |
391 | r= 0; goto xit; |
96e79df5 |
392 | default: |
393 | abort(); |
6f17710a |
394 | } |
74c94831 |
395 | if (fd == ads->udpsocket) { |
dfdbb32c |
396 | for (;;) { |
397 | udpaddrlen= sizeof(udpaddr); |
29cf9c44 |
398 | r= recvfrom(ads->udpsocket,udpbuf,sizeof(udpbuf),0, |
399 | (struct sockaddr*)&udpaddr,&udpaddrlen); |
dfdbb32c |
400 | if (r<0) { |
1389dc72 |
401 | if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; } |
74c94831 |
402 | if (errno == EINTR) continue; |
1389dc72 |
403 | if (errno_resources(errno)) { r= errno; goto xit; } |
74c94831 |
404 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); |
1389dc72 |
405 | r= 0; goto xit; |
dfdbb32c |
406 | } |
407 | if (udpaddrlen != sizeof(udpaddr)) { |
ae41e040 |
408 | adns__diag(ads,-1,0,"datagram received with wrong address length %d" |
cc0f95d0 |
409 | " (expected %lu)", udpaddrlen, |
410 | (unsigned long)sizeof(udpaddr)); |
dfdbb32c |
411 | continue; |
412 | } |
413 | if (udpaddr.sin_family != AF_INET) { |
ae41e040 |
414 | adns__diag(ads,-1,0,"datagram received with wrong protocol family" |
d05cc330 |
415 | " %u (expected %u)",udpaddr.sin_family,AF_INET); |
dfdbb32c |
416 | continue; |
417 | } |
5c596e4d |
418 | if (ntohs(udpaddr.sin_port) != DNS_PORT) { |
9c344a42 |
419 | adns__diag(ads,-1,0,"datagram received from wrong port" |
420 | " %u (expected %u)", ntohs(udpaddr.sin_port),DNS_PORT); |
dfdbb32c |
421 | continue; |
422 | } |
423 | for (serv= 0; |
424 | serv < ads->nservers && |
425 | ads->servers[serv].addr.s_addr != udpaddr.sin_addr.s_addr; |
426 | serv++); |
427 | if (serv >= ads->nservers) { |
ae41e040 |
428 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", |
d05cc330 |
429 | inet_ntoa(udpaddr.sin_addr)); |
dfdbb32c |
430 | continue; |
431 | } |
c84b7355 |
432 | adns__procdgram(ads,udpbuf,r,serv,0,*now); |
6f17710a |
433 | } |
dfdbb32c |
434 | } |
1389dc72 |
435 | r= 0; |
436 | xit: |
2ac463bf |
437 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
438 | return r; |
6f17710a |
439 | } |
6f17710a |
440 | |
74c94831 |
441 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
442 | int r; |
443 | |
2ac463bf |
444 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
445 | |
74c94831 |
446 | switch (ads->tcpstate) { |
447 | case server_disconnected: |
486ee6b1 |
448 | case server_broken: |
74c94831 |
449 | break; |
450 | case server_connecting: |
451 | if (fd != ads->tcpsocket) break; |
452 | assert(ads->tcprecv.used==0); |
ab898cf4 |
453 | assert(ads->tcprecv_skip==0); |
74c94831 |
454 | for (;;) { |
1389dc72 |
455 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; } |
74c94831 |
456 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
457 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { |
458 | tcp_connected(ads,*now); |
1389dc72 |
459 | r= 0; goto xit; |
74c94831 |
460 | } |
461 | if (r>0) { |
462 | adns__tcp_broken(ads,"connect/read","sent data before first request"); |
1389dc72 |
463 | r= 0; goto xit; |
74c94831 |
464 | } |
465 | if (errno==EINTR) continue; |
1389dc72 |
466 | if (errno_resources(errno)) { r= errno; goto xit; } |
74c94831 |
467 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
1389dc72 |
468 | r= 0; goto xit; |
74c94831 |
469 | } /* not reached */ |
470 | case server_ok: |
486ee6b1 |
471 | if (fd != ads->tcpsocket) break; |
472 | while (ads->tcpsend.used) { |
74c94831 |
473 | adns__sigpipe_protect(ads); |
474 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); |
475 | adns__sigpipe_unprotect(ads); |
476 | if (r<0) { |
477 | if (errno==EINTR) continue; |
1389dc72 |
478 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
479 | if (errno_resources(errno)) { r= errno; goto xit; } |
74c94831 |
480 | adns__tcp_broken(ads,"write",strerror(errno)); |
1389dc72 |
481 | r= 0; goto xit; |
74c94831 |
482 | } else if (r>0) { |
483 | ads->tcpsend.used -= r; |
484 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); |
485 | } |
486ee6b1 |
486 | } |
487 | r= 0; |
488 | goto xit; |
74c94831 |
489 | default: |
490 | abort(); |
491 | } |
1389dc72 |
492 | r= 0; |
493 | xit: |
2ac463bf |
494 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
495 | return r; |
74c94831 |
496 | } |
497 | |
9c344a42 |
498 | int adns_processexceptional(adns_state ads, int fd, |
499 | const struct timeval *now) { |
2ac463bf |
500 | adns__consistency(ads,0,cc_entex); |
74c94831 |
501 | switch (ads->tcpstate) { |
502 | case server_disconnected: |
486ee6b1 |
503 | case server_broken: |
74c94831 |
504 | break; |
505 | case server_connecting: |
506 | case server_ok: |
507 | if (fd != ads->tcpsocket) break; |
508 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); |
1389dc72 |
509 | break; |
74c94831 |
510 | default: |
511 | abort(); |
512 | } |
2ac463bf |
513 | adns__consistency(ads,0,cc_entex); |
74c94831 |
514 | return 0; |
515 | } |
516 | |
517 | static void fd_event(adns_state ads, int fd, |
518 | int revent, int pollflag, |
519 | int maxfd, const fd_set *fds, |
9c344a42 |
520 | int (*func)(adns_state, int fd, |
521 | const struct timeval *now), |
74c94831 |
522 | struct timeval now, int *r_r) { |
6f17710a |
523 | int r; |
74c94831 |
524 | |
525 | if (!(revent & pollflag)) return; |
526 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; |
527 | r= func(ads,fd,&now); |
528 | if (r) { |
529 | if (r_r) { |
530 | *r_r= r; |
531 | } else { |
9c344a42 |
532 | adns__diag(ads,-1,0,"process fd failed after select:" |
533 | " %s",strerror(errno)); |
74c94831 |
534 | adns_globalsystemfailure(ads); |
535 | } |
536 | } |
537 | } |
538 | |
539 | void adns__fdevents(adns_state ads, |
540 | const struct pollfd *pollfds, int npollfds, |
541 | int maxfd, const fd_set *readfds, |
542 | const fd_set *writefds, const fd_set *exceptfds, |
543 | struct timeval now, int *r_r) { |
544 | int i, fd, revents; |
545 | |
546 | for (i=0; i<npollfds; i++) { |
547 | fd= pollfds[i].fd; |
548 | if (fd >= maxfd) maxfd= fd+1; |
549 | revents= pollfds[i].revents; |
9c344a42 |
550 | #define EV(pollfl,fds,how) \ |
551 | fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r) |
552 | EV( POLLIN, readfds, readable ); |
553 | EV( POLLOUT, writefds, writeable ); |
554 | EV( POLLPRI, exceptfds, exceptional ); |
555 | #undef EV |
74c94831 |
556 | } |
557 | } |
dfdbb32c |
558 | |
74c94831 |
559 | /* Wrappers for select(2). */ |
560 | |
561 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, |
562 | fd_set *writefds_io, fd_set *exceptfds_io, |
563 | struct timeval **tv_mod, struct timeval *tv_tobuf, |
564 | const struct timeval *now) { |
565 | struct timeval tv_nowbuf; |
566 | struct pollfd pollfds[MAX_POLLFDS]; |
567 | int i, fd, maxfd, npollfds; |
568 | |
2ac463bf |
569 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
570 | |
74c94831 |
571 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
572 | /* The caller is planning to sleep. */ |
573 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); |
caae234b |
574 | if (!now) { inter_immed(tv_mod,tv_tobuf); goto xit; } |
da0e3c0a |
575 | adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now); |
74c94831 |
576 | } |
577 | |
578 | npollfds= adns__pollfds(ads,pollfds); |
579 | maxfd= *maxfd_io; |
580 | for (i=0; i<npollfds; i++) { |
581 | fd= pollfds[i].fd; |
582 | if (fd >= maxfd) maxfd= fd+1; |
583 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); |
584 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); |
585 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); |
586 | } |
587 | *maxfd_io= maxfd; |
1389dc72 |
588 | |
589 | xit: |
2ac463bf |
590 | adns__consistency(ads,0,cc_entex); |
74c94831 |
591 | } |
592 | |
593 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, |
594 | const fd_set *writefds, const fd_set *exceptfds, |
595 | const struct timeval *now) { |
4f973eb5 |
596 | struct timeval tv_buf; |
74c94831 |
597 | struct pollfd pollfds[MAX_POLLFDS]; |
4f973eb5 |
598 | int npollfds, i; |
74c94831 |
599 | |
2ac463bf |
600 | adns__consistency(ads,0,cc_entex); |
4f973eb5 |
601 | adns__must_gettimeofday(ads,&now,&tv_buf); |
1389dc72 |
602 | if (!now) goto xit; |
74c94831 |
603 | adns_processtimeouts(ads,now); |
604 | |
605 | npollfds= adns__pollfds(ads,pollfds); |
4f973eb5 |
606 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
74c94831 |
607 | adns__fdevents(ads, |
608 | pollfds,npollfds, |
609 | maxfd,readfds,writefds,exceptfds, |
610 | *now, 0); |
1389dc72 |
611 | xit: |
2ac463bf |
612 | adns__consistency(ads,0,cc_entex); |
74c94831 |
613 | } |
614 | |
615 | /* General helpful functions. */ |
616 | |
617 | void adns_globalsystemfailure(adns_state ads) { |
2ac463bf |
618 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
619 | |
d0a057ac |
620 | while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail); |
621 | while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail); |
74c94831 |
622 | |
623 | switch (ads->tcpstate) { |
624 | case server_connecting: |
625 | case server_ok: |
d0a057ac |
626 | adns__tcp_broken(ads,0,0); |
74c94831 |
627 | break; |
628 | case server_disconnected: |
486ee6b1 |
629 | case server_broken: |
74c94831 |
630 | break; |
631 | default: |
632 | abort(); |
633 | } |
2ac463bf |
634 | adns__consistency(ads,0,cc_entex); |
6f17710a |
635 | } |
636 | |
74c94831 |
637 | int adns_processany(adns_state ads) { |
634186ec |
638 | int r, i; |
74c94831 |
639 | struct timeval now; |
640 | struct pollfd pollfds[MAX_POLLFDS]; |
641 | int npollfds; |
642 | |
2ac463bf |
643 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
644 | |
74c94831 |
645 | r= gettimeofday(&now,0); |
646 | if (!r) adns_processtimeouts(ads,&now); |
647 | |
82ab0d30 |
648 | /* We just use adns__fdevents to loop over the fd's trying them. |
649 | * This seems more sensible than calling select, since we're most |
650 | * likely just to want to do a read on one or two fds anyway. |
651 | */ |
74c94831 |
652 | npollfds= adns__pollfds(ads,pollfds); |
95fa67fd |
653 | for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events & ~POLLPRI; |
74c94831 |
654 | adns__fdevents(ads, |
655 | pollfds,npollfds, |
656 | 0,0,0,0, |
657 | now,&r); |
1389dc72 |
658 | |
2ac463bf |
659 | adns__consistency(ads,0,cc_entex); |
d16697d9 |
660 | return 0; |
74c94831 |
661 | } |
96e79df5 |
662 | |
d05cc330 |
663 | void adns__autosys(adns_state ads, struct timeval now) { |
96e79df5 |
664 | if (ads->iflags & adns_if_noautosys) return; |
74c94831 |
665 | adns_processany(ads); |
96e79df5 |
666 | } |
667 | |
ef20fccf |
668 | int adns__internal_check(adns_state ads, |
669 | adns_query *query_io, |
670 | adns_answer **answer, |
671 | void **context_r) { |
6f17710a |
672 | adns_query qu; |
673 | |
674 | qu= *query_io; |
675 | if (!qu) { |
5773be3c |
676 | if (ads->output.head) { |
677 | qu= ads->output.head; |
d0a057ac |
678 | } else if (ads->udpw.head || ads->tcpw.head) { |
5773be3c |
679 | return EAGAIN; |
680 | } else { |
681 | return ESRCH; |
682 | } |
6f17710a |
683 | } else { |
c6f9dc7b |
684 | if (qu->id>=0) return EAGAIN; |
6f17710a |
685 | } |
686 | LIST_UNLINK(ads->output,qu); |
965c9782 |
687 | *answer= qu->answer; |
cd1bde2f |
688 | if (context_r) *context_r= qu->ctx.ext; |
8f2aa812 |
689 | *query_io= qu; |
6f17710a |
690 | free(qu); |
691 | return 0; |
692 | } |
693 | |
694 | int adns_wait(adns_state ads, |
695 | adns_query *query_io, |
696 | adns_answer **answer_r, |
697 | void **context_r) { |
74c94831 |
698 | int r, maxfd, rsel; |
6f17710a |
699 | fd_set readfds, writefds, exceptfds; |
caae234b |
700 | struct timeval tvbuf, *tvp; |
6f17710a |
701 | |
2ac463bf |
702 | adns__consistency(ads,*query_io,cc_entex); |
6f17710a |
703 | for (;;) { |
ef20fccf |
704 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
c6f9dc7b |
705 | if (r != EAGAIN) break; |
6f17710a |
706 | maxfd= 0; tvp= 0; |
dfdbb32c |
707 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
74c94831 |
708 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
8744cce8 |
709 | assert(tvp); |
6f17710a |
710 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
f318f883 |
711 | if (rsel==-1) { |
74c94831 |
712 | if (errno == EINTR) { |
1389dc72 |
713 | if (ads->iflags & adns_if_eintr) { r= EINTR; break; } |
74c94831 |
714 | } else { |
715 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); |
716 | adns_globalsystemfailure(ads); |
717 | } |
718 | } else { |
719 | assert(rsel >= 0); |
720 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); |
f318f883 |
721 | } |
6f17710a |
722 | } |
2ac463bf |
723 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
724 | return r; |
6f17710a |
725 | } |
726 | |
727 | int adns_check(adns_state ads, |
728 | adns_query *query_io, |
729 | adns_answer **answer_r, |
730 | void **context_r) { |
d05cc330 |
731 | struct timeval now; |
732 | int r; |
733 | |
2ac463bf |
734 | adns__consistency(ads,*query_io,cc_entex); |
74c94831 |
735 | r= gettimeofday(&now,0); |
736 | if (!r) adns__autosys(ads,now); |
1389dc72 |
737 | |
ef20fccf |
738 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
2ac463bf |
739 | adns__consistency(ads,0,cc_entex); |
1389dc72 |
740 | return r; |
6f17710a |
741 | } |