Commit | Line | Data |
---|---|---|
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 | |
7f8bbe29 | 16 | * the Free Software Foundation; either version 3, or (at your option) |
e576be50 | 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 | |
8c09a4c6 | 25 | * along with this program; if not, write to the Free Software Foundation. |
e576be50 | 26 | */ |
656b2da9 | 27 | |
4353a5c4 | 28 | #include <errno.h> |
29 | #include <stdlib.h> | |
0f091044 | 30 | #include <unistd.h> |
4353a5c4 | 31 | |
0f091044 | 32 | #include <sys/types.h> |
33 | #include <sys/time.h> | |
4353a5c4 | 34 | #include <netdb.h> |
eec1d9c8 | 35 | #include <sys/socket.h> |
36 | #include <netinet/in.h> | |
4353a5c4 | 37 | #include <arpa/inet.h> |
38 | ||
39 | #include "internal.h" | |
2953d358 | 40 | #include "tvarith.h" |
37e28fde | 41 | |
620c146d | 42 | /* TCP connection management. */ |
43 | ||
f7f83b4a | 44 | static void tcp_close(adns_state ads) { |
620c146d | 45 | close(ads->tcpsocket); |
6a578b2c | 46 | ads->tcpsocket= -1; |
70ad7a2a | 47 | ads->tcprecv.used= ads->tcprecv_skip= ads->tcpsend.used= 0; |
620c146d | 48 | } |
656b2da9 | 49 | |
8402e34c | 50 | void adns__tcp_broken(adns_state ads, const char *what, const char *why) { |
51 | int serv; | |
fb901bf5 | 52 | adns_query qu; |
8402e34c | 53 | |
54 | assert(ads->tcpstate == server_connecting || ads->tcpstate == server_ok); | |
ddfda861 | 55 | serv= ads->tcpserver; |
f7f83b4a | 56 | if (what) adns__warn(ads,serv,0,"TCP connection failed: %s: %s",what,why); |
57 | ||
fb901bf5 | 58 | if (ads->tcpstate == server_connecting) { |
59 | /* Counts as a retry for all the queries waiting for TCP. */ | |
60 | for (qu= ads->tcpw.head; qu; qu= qu->next) | |
61 | qu->retries++; | |
62 | } | |
63 | ||
f7f83b4a | 64 | tcp_close(ads); |
65 | ads->tcpstate= server_broken; | |
66 | ads->tcpserver= (serv+1)%ads->nservers; | |
8402e34c | 67 | } |
68 | ||
ddfda861 | 69 | static void tcp_connected(adns_state ads, struct timeval now) { |
4353a5c4 | 70 | adns_query qu, nqu; |
71 | ||
68442019 | 72 | adns__debug(ads,ads->tcpserver,0,"TCP connected"); |
4353a5c4 | 73 | ads->tcpstate= server_ok; |
f7f83b4a | 74 | for (qu= ads->tcpw.head; qu && ads->tcpstate == server_ok; qu= nqu) { |
ddfda861 | 75 | nqu= qu->next; |
f7f83b4a | 76 | assert(qu->state == query_tcpw); |
77 | adns__querysend_tcp(qu,now); | |
ddfda861 | 78 | } |
79 | } | |
80 | ||
237ce710 | 81 | static void tcp_broken_events(adns_state ads) { |
82 | adns_query qu, nqu; | |
83 | ||
84 | assert(ads->tcpstate == server_broken); | |
85 | for (qu= ads->tcpw.head; qu; qu= nqu) { | |
86 | nqu= qu->next; | |
87 | assert(qu->state == query_tcpw); | |
88 | if (qu->retries > ads->nservers) { | |
89 | LIST_UNLINK(ads->tcpw,qu); | |
90 | adns__query_fail(qu,adns_s_allservfail); | |
91 | } | |
92 | } | |
93 | ads->tcpstate= server_disconnected; | |
94 | } | |
95 | ||
ddfda861 | 96 | void adns__tcp_tryconnect(adns_state ads, struct timeval now) { |
8402e34c | 97 | int r, fd, tries; |
f930c455 | 98 | adns_rr_addr *addr; |
4353a5c4 | 99 | struct protoent *proto; |
8402e34c | 100 | |
101 | for (tries=0; tries<ads->nservers; tries++) { | |
f7f83b4a | 102 | switch (ads->tcpstate) { |
103 | case server_connecting: | |
104 | case server_ok: | |
105 | case server_broken: | |
106 | return; | |
107 | case server_disconnected: | |
108 | break; | |
109 | default: | |
110 | abort(); | |
111 | } | |
112 | ||
4353a5c4 | 113 | assert(!ads->tcpsend.used); |
114 | assert(!ads->tcprecv.used); | |
70ad7a2a | 115 | assert(!ads->tcprecv_skip); |
8402e34c | 116 | |
117 | proto= getprotobyname("tcp"); | |
609133ee | 118 | if (!proto) { |
119 | adns__diag(ads,-1,0,"unable to find protocol no. for TCP !"); | |
120 | return; | |
121 | } | |
f930c455 MW |
122 | addr = &ads->servers[ads->tcpserver]; |
123 | fd= socket(addr->addr.sa.sa_family, SOCK_STREAM, proto->p_proto); | |
4353a5c4 | 124 | if (fd<0) { |
68442019 | 125 | adns__diag(ads,-1,0,"cannot create TCP socket: %s",strerror(errno)); |
4353a5c4 | 126 | return; |
127 | } | |
128 | r= adns__setnonblock(ads,fd); | |
129 | if (r) { | |
609133ee | 130 | adns__diag(ads,-1,0,"cannot make TCP socket nonblocking:" |
131 | " %s",strerror(r)); | |
4353a5c4 | 132 | close(fd); |
133 | return; | |
134 | } | |
f930c455 | 135 | r= connect(fd,&addr->addr.sa,addr->len); |
8402e34c | 136 | ads->tcpsocket= fd; |
137 | ads->tcpstate= server_connecting; | |
f7f83b4a | 138 | if (r==0) { tcp_connected(ads,now); return; } |
139 | if (errno == EWOULDBLOCK || errno == EINPROGRESS) { | |
140 | ads->tcptimeout= now; | |
141 | timevaladd(&ads->tcptimeout,TCPCONNMS); | |
142 | return; | |
143 | } | |
ddfda861 | 144 | adns__tcp_broken(ads,"connect",strerror(errno)); |
237ce710 | 145 | tcp_broken_events(ads); |
8402e34c | 146 | } |
147 | } | |
148 | ||
620c146d | 149 | /* Timeout handling functions. */ |
150 | ||
151 | void adns__must_gettimeofday(adns_state ads, const struct timeval **now_io, | |
152 | struct timeval *tv_buf) { | |
153 | const struct timeval *now; | |
154 | int r; | |
155 | ||
156 | now= *now_io; | |
157 | if (now) return; | |
158 | r= gettimeofday(tv_buf,0); if (!r) { *now_io= tv_buf; return; } | |
159 | adns__diag(ads,-1,0,"gettimeofday failed: %s",strerror(errno)); | |
160 | adns_globalsystemfailure(ads); | |
161 | return; | |
162 | } | |
4353a5c4 | 163 | |
4fad263d | 164 | static void inter_immed(struct timeval **tv_io, struct timeval *tvbuf) { |
165 | struct timeval *rbuf; | |
166 | ||
167 | if (!tv_io) return; | |
168 | ||
169 | rbuf= *tv_io; | |
170 | if (!rbuf) { *tv_io= rbuf= tvbuf; } | |
171 | ||
172 | timerclear(rbuf); | |
173 | } | |
174 | ||
4353a5c4 | 175 | static void inter_maxto(struct timeval **tv_io, struct timeval *tvbuf, |
176 | struct timeval maxto) { | |
177 | struct timeval *rbuf; | |
178 | ||
179 | if (!tv_io) return; | |
180 | rbuf= *tv_io; | |
94436798 | 181 | if (!rbuf) { |
182 | *tvbuf= maxto; *tv_io= tvbuf; | |
183 | } else { | |
184 | if (timercmp(rbuf,&maxto,>)) *rbuf= maxto; | |
185 | } | |
ffbda80c | 186 | /*fprintf(stderr,"inter_maxto maxto=%ld.%06ld result=%ld.%06ld\n", |
187 | maxto.tv_sec,maxto.tv_usec,(**tv_io).tv_sec,(**tv_io).tv_usec);*/ | |
4353a5c4 | 188 | } |
189 | ||
190 | static void inter_maxtoabs(struct timeval **tv_io, struct timeval *tvbuf, | |
191 | struct timeval now, struct timeval maxtime) { | |
f7f83b4a | 192 | /* tv_io may be 0 */ |
4353a5c4 | 193 | ldiv_t dr; |
194 | ||
ffbda80c | 195 | /*fprintf(stderr,"inter_maxtoabs now=%ld.%06ld maxtime=%ld.%06ld\n", |
196 | now.tv_sec,now.tv_usec,maxtime.tv_sec,maxtime.tv_usec);*/ | |
4353a5c4 | 197 | if (!tv_io) return; |
94436798 | 198 | maxtime.tv_sec -= (now.tv_sec+2); |
199 | maxtime.tv_usec -= (now.tv_usec-2000000); | |
200 | dr= ldiv(maxtime.tv_usec,1000000); | |
4353a5c4 | 201 | maxtime.tv_sec += dr.quot; |
94436798 | 202 | maxtime.tv_usec -= dr.quot*1000000; |
203 | if (maxtime.tv_sec<0) timerclear(&maxtime); | |
4353a5c4 | 204 | inter_maxto(tv_io,tvbuf,maxtime); |
205 | } | |
206 | ||
f7f83b4a | 207 | static void timeouts_queue(adns_state ads, int act, |
208 | struct timeval **tv_io, struct timeval *tvbuf, | |
209 | struct timeval now, struct query_queue *queue) { | |
4353a5c4 | 210 | adns_query qu, nqu; |
f7f83b4a | 211 | |
212 | for (qu= queue->head; qu; qu= nqu) { | |
4353a5c4 | 213 | nqu= qu->next; |
d855b532 | 214 | if (!timercmp(&now,&qu->timeout,>)) { |
620c146d | 215 | inter_maxtoabs(tv_io,tvbuf,now,qu->timeout); |
216 | } else { | |
4fad263d | 217 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a | 218 | LIST_UNLINK(*queue,qu); |
d8c062fa | 219 | if (qu->state != query_tosend) { |
3955725c | 220 | adns__query_fail(qu,adns_s_timeout); |
4353a5c4 | 221 | } else { |
d8c062fa | 222 | adns__query_send(qu,now); |
4353a5c4 | 223 | } |
f7f83b4a | 224 | nqu= queue->head; |
4353a5c4 | 225 | } |
226 | } | |
f7f83b4a | 227 | } |
228 | ||
229 | static void tcp_events(adns_state ads, int act, | |
230 | struct timeval **tv_io, struct timeval *tvbuf, | |
231 | struct timeval now) { | |
f7f83b4a | 232 | for (;;) { |
233 | switch (ads->tcpstate) { | |
234 | case server_broken: | |
4fad263d | 235 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
237ce710 | 236 | tcp_broken_events(ads); |
f7f83b4a | 237 | case server_disconnected: /* fall through */ |
238 | if (!ads->tcpw.head) return; | |
4fad263d | 239 | if (!act) { inter_immed(tv_io,tvbuf); return; } |
f7f83b4a | 240 | adns__tcp_tryconnect(ads,now); |
241 | break; | |
242 | case server_ok: | |
243 | if (ads->tcpw.head) return; | |
244 | if (!ads->tcptimeout.tv_sec) { | |
245 | assert(!ads->tcptimeout.tv_usec); | |
246 | ads->tcptimeout= now; | |
247 | timevaladd(&ads->tcptimeout,TCPIDLEMS); | |
248 | } | |
249 | case server_connecting: /* fall through */ | |
4fad263d | 250 | if (!act || !timercmp(&now,&ads->tcptimeout,>)) { |
f7f83b4a | 251 | inter_maxtoabs(tv_io,tvbuf,now,ads->tcptimeout); |
252 | return; | |
253 | } { | |
254 | /* TCP timeout has happened */ | |
255 | switch (ads->tcpstate) { | |
256 | case server_connecting: /* failed to connect */ | |
257 | adns__tcp_broken(ads,"unable to make connection","timed out"); | |
258 | break; | |
259 | case server_ok: /* idle timeout */ | |
260 | tcp_close(ads); | |
261 | ads->tcpstate= server_disconnected; | |
262 | return; | |
263 | default: | |
264 | abort(); | |
265 | } | |
266 | } | |
267 | break; | |
268 | default: | |
269 | abort(); | |
270 | } | |
271 | } | |
4fad263d | 272 | return; |
f7f83b4a | 273 | } |
274 | ||
275 | void adns__timeouts(adns_state ads, int act, | |
276 | struct timeval **tv_io, struct timeval *tvbuf, | |
277 | struct timeval now) { | |
278 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->udpw); | |
279 | timeouts_queue(ads,act,tv_io,tvbuf,now, &ads->tcpw); | |
280 | tcp_events(ads,act,tv_io,tvbuf,now); | |
281 | } | |
94436798 | 282 | |
620c146d | 283 | void adns_firsttimeout(adns_state ads, |
284 | struct timeval **tv_io, struct timeval *tvbuf, | |
285 | struct timeval now) { | |
28de6442 | 286 | adns__consistency(ads,0,cc_entex); |
620c146d | 287 | adns__timeouts(ads, 0, tv_io,tvbuf, now); |
eb2a930e | 288 | adns__returning(ads,0); |
620c146d | 289 | } |
290 | ||
291 | void adns_processtimeouts(adns_state ads, const struct timeval *now) { | |
292 | struct timeval tv_buf; | |
293 | ||
28de6442 | 294 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 295 | adns__must_gettimeofday(ads,&now,&tv_buf); |
296 | if (now) adns__timeouts(ads, 1, 0,0, *now); | |
eb2a930e | 297 | adns__returning(ads,0); |
a8768e80 | 298 | } |
299 | ||
620c146d | 300 | /* fd handling functions. These are the top-level of the real work of |
301 | * reception and often transmission. | |
302 | */ | |
303 | ||
304 | int adns__pollfds(adns_state ads, struct pollfd pollfds_buf[MAX_POLLFDS]) { | |
305 | /* Returns the number of entries filled in. Always zeroes revents. */ | |
13d889da IJ |
306 | int nwanted=0; |
307 | #define ADD_POLLFD(wantfd, wantevents) do{ \ | |
308 | pollfds_buf[nwanted].fd= (wantfd); \ | |
309 | pollfds_buf[nwanted].events= (wantevents); \ | |
310 | pollfds_buf[nwanted].revents= 0; \ | |
311 | nwanted++; \ | |
312 | }while(0) | |
620c146d | 313 | |
3eb20edd | 314 | int i; |
a8768e80 | 315 | |
3eb20edd MW |
316 | assert(MAX_POLLFDS == MAXUDP + 1); |
317 | ||
97a937c8 IJ |
318 | for (i=0; i<ads->nudpsockets; i++) |
319 | ADD_POLLFD(ads->udpsockets[i].fd, POLLIN); | |
4353a5c4 | 320 | |
321 | switch (ads->tcpstate) { | |
322 | case server_disconnected: | |
6c68a593 | 323 | case server_broken: |
13d889da | 324 | break; |
4353a5c4 | 325 | case server_connecting: |
13d889da | 326 | ADD_POLLFD(ads->tcpsocket, POLLOUT); |
4353a5c4 | 327 | break; |
328 | case server_ok: | |
13d889da IJ |
329 | ADD_POLLFD(ads->tcpsocket, |
330 | ads->tcpsend.used ? POLLIN|POLLOUT|POLLPRI : POLLIN|POLLPRI); | |
e062dcae | 331 | break; |
4353a5c4 | 332 | default: |
333 | abort(); | |
334 | } | |
13d889da IJ |
335 | assert(nwanted<=MAX_POLLFDS); |
336 | #undef ADD_POLLFD | |
337 | return nwanted; | |
4353a5c4 | 338 | } |
339 | ||
620c146d | 340 | int adns_processreadable(adns_state ads, int fd, const struct timeval *now) { |
3eb20edd | 341 | int want, dgramlen, r, i, udpaddrlen, serv, old_skip; |
98a3f706 | 342 | byte udpbuf[DNS_MAXUDP]; |
3eb20edd MW |
343 | char addrbuf[ADNS_ADDR2TEXT_BUFLEN]; |
344 | struct udpsocket *udp; | |
345 | adns_sockaddr udpaddr; | |
620c146d | 346 | |
28de6442 | 347 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 348 | |
ddfda861 | 349 | switch (ads->tcpstate) { |
350 | case server_disconnected: | |
fb901bf5 | 351 | case server_broken: |
ddfda861 | 352 | case server_connecting: |
ddfda861 | 353 | break; |
354 | case server_ok: | |
620c146d | 355 | if (fd != ads->tcpsocket) break; |
70ad7a2a | 356 | assert(!ads->tcprecv_skip); |
428bd682 | 357 | do { |
70ad7a2a | 358 | if (ads->tcprecv.used >= ads->tcprecv_skip+2) { |
359 | dgramlen= ((ads->tcprecv.buf[ads->tcprecv_skip]<<8) | | |
360 | ads->tcprecv.buf[ads->tcprecv_skip+1]); | |
361 | if (ads->tcprecv.used >= ads->tcprecv_skip+2+dgramlen) { | |
362 | old_skip= ads->tcprecv_skip; | |
363 | ads->tcprecv_skip += 2+dgramlen; | |
364 | adns__procdgram(ads, ads->tcprecv.buf+old_skip+2, | |
365 | dgramlen, ads->tcpserver, 1,*now); | |
366 | continue; | |
656b2da9 | 367 | } else { |
70ad7a2a | 368 | want= 2+dgramlen; |
656b2da9 | 369 | } |
70ad7a2a | 370 | } else { |
371 | want= 2; | |
656b2da9 | 372 | } |
70ad7a2a | 373 | ads->tcprecv.used -= ads->tcprecv_skip; |
609133ee | 374 | memmove(ads->tcprecv.buf, ads->tcprecv.buf+ads->tcprecv_skip, |
375 | ads->tcprecv.used); | |
70ad7a2a | 376 | ads->tcprecv_skip= 0; |
3e2e5fab | 377 | if (!adns__vbuf_ensure(&ads->tcprecv,want)) { r= ENOMEM; goto xit; } |
620c146d | 378 | assert(ads->tcprecv.used <= ads->tcprecv.avail); |
379 | if (ads->tcprecv.used == ads->tcprecv.avail) continue; | |
380 | r= read(ads->tcpsocket, | |
381 | ads->tcprecv.buf+ads->tcprecv.used, | |
382 | ads->tcprecv.avail-ads->tcprecv.used); | |
383 | if (r>0) { | |
384 | ads->tcprecv.used+= r; | |
385 | } else { | |
386 | if (r) { | |
3e2e5fab | 387 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
620c146d | 388 | if (errno==EINTR) continue; |
3e2e5fab | 389 | if (errno_resources(errno)) { r= errno; goto xit; } |
656b2da9 | 390 | } |
620c146d | 391 | adns__tcp_broken(ads,"read",r?strerror(errno):"closed"); |
656b2da9 | 392 | } |
428bd682 | 393 | } while (ads->tcpstate == server_ok); |
394 | r= 0; goto xit; | |
ddfda861 | 395 | default: |
396 | abort(); | |
656b2da9 | 397 | } |
97a937c8 IJ |
398 | for (i=0; i<ads->nudpsockets; i++) { |
399 | udp= &ads->udpsockets[i]; | |
41536342 IJ |
400 | if (fd != udp->fd) continue; |
401 | for (;;) { | |
402 | udpaddrlen= sizeof(udpaddr); | |
403 | r= recvfrom(fd,udpbuf,sizeof(udpbuf),0, &udpaddr.sa,&udpaddrlen); | |
404 | if (r<0) { | |
405 | if (errno == EAGAIN || errno == EWOULDBLOCK) { r= 0; goto xit; } | |
406 | if (errno == EINTR) continue; | |
407 | if (errno_resources(errno)) { r= errno; goto xit; } | |
408 | adns__warn(ads,-1,0,"datagram receive error: %s",strerror(errno)); | |
409 | r= 0; goto xit; | |
37e28fde | 410 | } |
41536342 IJ |
411 | for (serv= 0; |
412 | serv < ads->nservers && | |
413 | !adns__sockaddrs_equal(&udpaddr.sa, | |
414 | &ads->servers[serv].addr.sa); | |
415 | serv++); | |
416 | if (serv >= ads->nservers) { | |
417 | adns__warn(ads,-1,0,"datagram received from unknown nameserver %s", | |
418 | adns__sockaddr_ntoa(&udpaddr.sa, addrbuf)); | |
419 | continue; | |
420 | } | |
421 | adns__procdgram(ads,udpbuf,r,serv,0,*now); | |
656b2da9 | 422 | } |
41536342 | 423 | break; |
37e28fde | 424 | } |
3e2e5fab | 425 | r= 0; |
426 | xit: | |
eb2a930e | 427 | adns__returning(ads,0); |
3e2e5fab | 428 | return r; |
656b2da9 | 429 | } |
656b2da9 | 430 | |
620c146d | 431 | int adns_processwriteable(adns_state ads, int fd, const struct timeval *now) { |
656b2da9 | 432 | int r; |
620c146d | 433 | |
28de6442 | 434 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 435 | |
620c146d | 436 | switch (ads->tcpstate) { |
437 | case server_disconnected: | |
fb901bf5 | 438 | case server_broken: |
620c146d | 439 | break; |
440 | case server_connecting: | |
441 | if (fd != ads->tcpsocket) break; | |
442 | assert(ads->tcprecv.used==0); | |
70ad7a2a | 443 | assert(ads->tcprecv_skip==0); |
620c146d | 444 | for (;;) { |
3e2e5fab | 445 | if (!adns__vbuf_ensure(&ads->tcprecv,1)) { r= ENOMEM; goto xit; } |
620c146d | 446 | r= read(ads->tcpsocket,&ads->tcprecv.buf,1); |
447 | if (r==0 || (r<0 && (errno==EAGAIN || errno==EWOULDBLOCK))) { | |
448 | tcp_connected(ads,*now); | |
3e2e5fab | 449 | r= 0; goto xit; |
620c146d | 450 | } |
451 | if (r>0) { | |
452 | adns__tcp_broken(ads,"connect/read","sent data before first request"); | |
3e2e5fab | 453 | r= 0; goto xit; |
620c146d | 454 | } |
455 | if (errno==EINTR) continue; | |
3e2e5fab | 456 | if (errno_resources(errno)) { r= errno; goto xit; } |
620c146d | 457 | adns__tcp_broken(ads,"connect/read",strerror(errno)); |
3e2e5fab | 458 | r= 0; goto xit; |
620c146d | 459 | } /* not reached */ |
460 | case server_ok: | |
fb901bf5 | 461 | if (fd != ads->tcpsocket) break; |
462 | while (ads->tcpsend.used) { | |
620c146d | 463 | adns__sigpipe_protect(ads); |
464 | r= write(ads->tcpsocket,ads->tcpsend.buf,ads->tcpsend.used); | |
465 | adns__sigpipe_unprotect(ads); | |
466 | if (r<0) { | |
467 | if (errno==EINTR) continue; | |
3e2e5fab | 468 | if (errno==EAGAIN || errno==EWOULDBLOCK) { r= 0; goto xit; } |
469 | if (errno_resources(errno)) { r= errno; goto xit; } | |
620c146d | 470 | adns__tcp_broken(ads,"write",strerror(errno)); |
3e2e5fab | 471 | r= 0; goto xit; |
620c146d | 472 | } else if (r>0) { |
473 | ads->tcpsend.used -= r; | |
474 | memmove(ads->tcpsend.buf,ads->tcpsend.buf+r,ads->tcpsend.used); | |
475 | } | |
fb901bf5 | 476 | } |
477 | r= 0; | |
478 | goto xit; | |
620c146d | 479 | default: |
480 | abort(); | |
481 | } | |
3e2e5fab | 482 | r= 0; |
483 | xit: | |
eb2a930e | 484 | adns__returning(ads,0); |
3e2e5fab | 485 | return r; |
620c146d | 486 | } |
487 | ||
609133ee | 488 | int adns_processexceptional(adns_state ads, int fd, |
489 | const struct timeval *now) { | |
28de6442 | 490 | adns__consistency(ads,0,cc_entex); |
620c146d | 491 | switch (ads->tcpstate) { |
492 | case server_disconnected: | |
fb901bf5 | 493 | case server_broken: |
620c146d | 494 | break; |
495 | case server_connecting: | |
496 | case server_ok: | |
497 | if (fd != ads->tcpsocket) break; | |
498 | adns__tcp_broken(ads,"poll/select","exceptional condition detected"); | |
3e2e5fab | 499 | break; |
620c146d | 500 | default: |
501 | abort(); | |
502 | } | |
eb2a930e | 503 | adns__returning(ads,0); |
620c146d | 504 | return 0; |
505 | } | |
37e28fde | 506 | |
620c146d | 507 | static void fd_event(adns_state ads, int fd, |
508 | int revent, int pollflag, | |
509 | int maxfd, const fd_set *fds, | |
609133ee | 510 | int (*func)(adns_state, int fd, |
511 | const struct timeval *now), | |
620c146d | 512 | struct timeval now, int *r_r) { |
656b2da9 | 513 | int r; |
620c146d | 514 | |
515 | if (!(revent & pollflag)) return; | |
516 | if (fds && !(fd<maxfd && FD_ISSET(fd,fds))) return; | |
517 | r= func(ads,fd,&now); | |
518 | if (r) { | |
519 | if (r_r) { | |
520 | *r_r= r; | |
521 | } else { | |
609133ee | 522 | adns__diag(ads,-1,0,"process fd failed after select:" |
523 | " %s",strerror(errno)); | |
620c146d | 524 | adns_globalsystemfailure(ads); |
525 | } | |
526 | } | |
527 | } | |
528 | ||
529 | void adns__fdevents(adns_state ads, | |
530 | const struct pollfd *pollfds, int npollfds, | |
531 | int maxfd, const fd_set *readfds, | |
532 | const fd_set *writefds, const fd_set *exceptfds, | |
533 | struct timeval now, int *r_r) { | |
534 | int i, fd, revents; | |
535 | ||
536 | for (i=0; i<npollfds; i++) { | |
537 | fd= pollfds[i].fd; | |
538 | if (fd >= maxfd) maxfd= fd+1; | |
539 | revents= pollfds[i].revents; | |
609133ee | 540 | #define EV(pollfl,fds,how) \ |
541 | fd_event(ads,fd, revents,pollfl, maxfd,fds, adns_process##how,now,r_r) | |
542 | EV( POLLIN, readfds, readable ); | |
543 | EV( POLLOUT, writefds, writeable ); | |
544 | EV( POLLPRI, exceptfds, exceptional ); | |
545 | #undef EV | |
620c146d | 546 | } |
547 | } | |
37e28fde | 548 | |
620c146d | 549 | /* Wrappers for select(2). */ |
550 | ||
551 | void adns_beforeselect(adns_state ads, int *maxfd_io, fd_set *readfds_io, | |
552 | fd_set *writefds_io, fd_set *exceptfds_io, | |
553 | struct timeval **tv_mod, struct timeval *tv_tobuf, | |
554 | const struct timeval *now) { | |
555 | struct timeval tv_nowbuf; | |
556 | struct pollfd pollfds[MAX_POLLFDS]; | |
557 | int i, fd, maxfd, npollfds; | |
558 | ||
28de6442 | 559 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 560 | |
620c146d | 561 | if (tv_mod && (!*tv_mod || (*tv_mod)->tv_sec || (*tv_mod)->tv_usec)) { |
562 | /* The caller is planning to sleep. */ | |
563 | adns__must_gettimeofday(ads,&now,&tv_nowbuf); | |
26cc07a3 | 564 | if (!now) { inter_immed(tv_mod,tv_tobuf); goto xit; } |
6c68a593 | 565 | adns__timeouts(ads, 0, tv_mod,tv_tobuf, *now); |
620c146d | 566 | } |
567 | ||
568 | npollfds= adns__pollfds(ads,pollfds); | |
569 | maxfd= *maxfd_io; | |
570 | for (i=0; i<npollfds; i++) { | |
571 | fd= pollfds[i].fd; | |
572 | if (fd >= maxfd) maxfd= fd+1; | |
573 | if (pollfds[i].events & POLLIN) FD_SET(fd,readfds_io); | |
574 | if (pollfds[i].events & POLLOUT) FD_SET(fd,writefds_io); | |
575 | if (pollfds[i].events & POLLPRI) FD_SET(fd,exceptfds_io); | |
576 | } | |
577 | *maxfd_io= maxfd; | |
3e2e5fab | 578 | |
579 | xit: | |
eb2a930e | 580 | adns__returning(ads,0); |
620c146d | 581 | } |
582 | ||
583 | void adns_afterselect(adns_state ads, int maxfd, const fd_set *readfds, | |
584 | const fd_set *writefds, const fd_set *exceptfds, | |
585 | const struct timeval *now) { | |
fc6a52ae | 586 | struct timeval tv_buf; |
620c146d | 587 | struct pollfd pollfds[MAX_POLLFDS]; |
fc6a52ae | 588 | int npollfds, i; |
620c146d | 589 | |
28de6442 | 590 | adns__consistency(ads,0,cc_entex); |
fc6a52ae | 591 | adns__must_gettimeofday(ads,&now,&tv_buf); |
3e2e5fab | 592 | if (!now) goto xit; |
620c146d | 593 | adns_processtimeouts(ads,now); |
594 | ||
595 | npollfds= adns__pollfds(ads,pollfds); | |
fc6a52ae | 596 | for (i=0; i<npollfds; i++) pollfds[i].revents= POLLIN|POLLOUT|POLLPRI; |
620c146d | 597 | adns__fdevents(ads, |
598 | pollfds,npollfds, | |
599 | maxfd,readfds,writefds,exceptfds, | |
600 | *now, 0); | |
3e2e5fab | 601 | xit: |
eb2a930e | 602 | adns__returning(ads,0); |
620c146d | 603 | } |
604 | ||
605 | /* General helpful functions. */ | |
606 | ||
607 | void adns_globalsystemfailure(adns_state ads) { | |
28de6442 | 608 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 609 | |
f7f83b4a | 610 | while (ads->udpw.head) adns__query_fail(ads->udpw.head, adns_s_systemfail); |
611 | while (ads->tcpw.head) adns__query_fail(ads->tcpw.head, adns_s_systemfail); | |
620c146d | 612 | |
613 | switch (ads->tcpstate) { | |
614 | case server_connecting: | |
615 | case server_ok: | |
f7f83b4a | 616 | adns__tcp_broken(ads,0,0); |
620c146d | 617 | break; |
618 | case server_disconnected: | |
fb901bf5 | 619 | case server_broken: |
620c146d | 620 | break; |
621 | default: | |
622 | abort(); | |
623 | } | |
eb2a930e | 624 | adns__returning(ads,0); |
656b2da9 | 625 | } |
626 | ||
620c146d | 627 | int adns_processany(adns_state ads) { |
aedf10f2 | 628 | int r, i; |
620c146d | 629 | struct timeval now; |
630 | struct pollfd pollfds[MAX_POLLFDS]; | |
631 | int npollfds; | |
632 | ||
28de6442 | 633 | adns__consistency(ads,0,cc_entex); |
3e2e5fab | 634 | |
620c146d | 635 | r= gettimeofday(&now,0); |
636 | if (!r) adns_processtimeouts(ads,&now); | |
637 | ||
25913ee2 | 638 | /* We just use adns__fdevents to loop over the fd's trying them. |
639 | * This seems more sensible than calling select, since we're most | |
640 | * likely just to want to do a read on one or two fds anyway. | |
641 | */ | |
620c146d | 642 | npollfds= adns__pollfds(ads,pollfds); |
1ed3dba4 | 643 | for (i=0; i<npollfds; i++) pollfds[i].revents= pollfds[i].events & ~POLLPRI; |
620c146d | 644 | adns__fdevents(ads, |
645 | pollfds,npollfds, | |
646 | 0,0,0,0, | |
647 | now,&r); | |
3e2e5fab | 648 | |
eb2a930e | 649 | adns__returning(ads,0); |
c118a725 | 650 | return 0; |
620c146d | 651 | } |
ddfda861 | 652 | |
4353a5c4 | 653 | void adns__autosys(adns_state ads, struct timeval now) { |
ddfda861 | 654 | if (ads->iflags & adns_if_noautosys) return; |
620c146d | 655 | adns_processany(ads); |
ddfda861 | 656 | } |
657 | ||
940356bd | 658 | int adns__internal_check(adns_state ads, |
659 | adns_query *query_io, | |
660 | adns_answer **answer, | |
661 | void **context_r) { | |
656b2da9 | 662 | adns_query qu; |
663 | ||
664 | qu= *query_io; | |
665 | if (!qu) { | |
4ae90a83 | 666 | if (ads->output.head) { |
667 | qu= ads->output.head; | |
f7f83b4a | 668 | } else if (ads->udpw.head || ads->tcpw.head) { |
4ae90a83 | 669 | return EAGAIN; |
670 | } else { | |
671 | return ESRCH; | |
672 | } | |
656b2da9 | 673 | } else { |
226c5eef | 674 | if (qu->id>=0) return EAGAIN; |
656b2da9 | 675 | } |
676 | LIST_UNLINK(ads->output,qu); | |
8e5b0abb | 677 | *answer= qu->answer; |
a6536d8b | 678 | if (context_r) *context_r= qu->ctx.ext; |
8ce38e76 | 679 | *query_io= qu; |
656b2da9 | 680 | free(qu); |
681 | return 0; | |
682 | } | |
683 | ||
684 | int adns_wait(adns_state ads, | |
685 | adns_query *query_io, | |
686 | adns_answer **answer_r, | |
687 | void **context_r) { | |
620c146d | 688 | int r, maxfd, rsel; |
656b2da9 | 689 | fd_set readfds, writefds, exceptfds; |
26cc07a3 | 690 | struct timeval tvbuf, *tvp; |
656b2da9 | 691 | |
28de6442 | 692 | adns__consistency(ads,*query_io,cc_entex); |
656b2da9 | 693 | for (;;) { |
940356bd | 694 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
226c5eef | 695 | if (r != EAGAIN) break; |
656b2da9 | 696 | maxfd= 0; tvp= 0; |
37e28fde | 697 | FD_ZERO(&readfds); FD_ZERO(&writefds); FD_ZERO(&exceptfds); |
620c146d | 698 | adns_beforeselect(ads,&maxfd,&readfds,&writefds,&exceptfds,&tvp,&tvbuf,0); |
4fad263d | 699 | assert(tvp); |
656b2da9 | 700 | rsel= select(maxfd,&readfds,&writefds,&exceptfds,tvp); |
88372443 | 701 | if (rsel==-1) { |
620c146d | 702 | if (errno == EINTR) { |
3e2e5fab | 703 | if (ads->iflags & adns_if_eintr) { r= EINTR; break; } |
620c146d | 704 | } else { |
705 | adns__diag(ads,-1,0,"select failed in wait: %s",strerror(errno)); | |
706 | adns_globalsystemfailure(ads); | |
707 | } | |
708 | } else { | |
709 | assert(rsel >= 0); | |
710 | adns_afterselect(ads,maxfd,&readfds,&writefds,&exceptfds,0); | |
88372443 | 711 | } |
656b2da9 | 712 | } |
eb2a930e | 713 | adns__returning(ads,0); |
3e2e5fab | 714 | return r; |
656b2da9 | 715 | } |
716 | ||
717 | int adns_check(adns_state ads, | |
718 | adns_query *query_io, | |
719 | adns_answer **answer_r, | |
720 | void **context_r) { | |
4353a5c4 | 721 | struct timeval now; |
722 | int r; | |
723 | ||
28de6442 | 724 | adns__consistency(ads,*query_io,cc_entex); |
620c146d | 725 | r= gettimeofday(&now,0); |
726 | if (!r) adns__autosys(ads,now); | |
3e2e5fab | 727 | |
940356bd | 728 | r= adns__internal_check(ads,query_io,answer_r,context_r); |
eb2a930e | 729 | adns__returning(ads,0); |
3e2e5fab | 730 | return r; |
656b2da9 | 731 | } |