xref: /freebsd/contrib/unbound/util/netevent.c (revision 0b57cec536236d46e3dba9bd041533462f33dbb7)
1 /*
2  * util/netevent.c - event notification
3  *
4  * Copyright (c) 2007, NLnet Labs. All rights reserved.
5  *
6  * This software is open source.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * Redistributions of source code must retain the above copyright notice,
13  * this list of conditions and the following disclaimer.
14  *
15  * Redistributions in binary form must reproduce the above copyright notice,
16  * this list of conditions and the following disclaimer in the documentation
17  * and/or other materials provided with the distribution.
18  *
19  * Neither the name of the NLNET LABS nor the names of its contributors may
20  * be used to endorse or promote products derived from this software without
21  * specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27  * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29  * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  */
35 
36 /**
37  * \file
38  *
39  * This file contains event notification functions.
40  */
41 #include "config.h"
42 #include "util/netevent.h"
43 #include "util/ub_event.h"
44 #include "util/log.h"
45 #include "util/net_help.h"
46 #include "util/tcp_conn_limit.h"
47 #include "util/fptr_wlist.h"
48 #include "sldns/pkthdr.h"
49 #include "sldns/sbuffer.h"
50 #include "sldns/str2wire.h"
51 #include "dnstap/dnstap.h"
52 #include "dnscrypt/dnscrypt.h"
53 #include "services/listen_dnsport.h"
54 #ifdef HAVE_OPENSSL_SSL_H
55 #include <openssl/ssl.h>
56 #endif
57 #ifdef HAVE_OPENSSL_ERR_H
58 #include <openssl/err.h>
59 #endif
60 
61 /* -------- Start of local definitions -------- */
62 /** if CMSG_ALIGN is not defined on this platform, a workaround */
63 #ifndef CMSG_ALIGN
64 #  ifdef __CMSG_ALIGN
65 #    define CMSG_ALIGN(n) __CMSG_ALIGN(n)
66 #  elif defined(CMSG_DATA_ALIGN)
67 #    define CMSG_ALIGN _CMSG_DATA_ALIGN
68 #  else
69 #    define CMSG_ALIGN(len) (((len)+sizeof(long)-1) & ~(sizeof(long)-1))
70 #  endif
71 #endif
72 
73 /** if CMSG_LEN is not defined on this platform, a workaround */
74 #ifndef CMSG_LEN
75 #  define CMSG_LEN(len) (CMSG_ALIGN(sizeof(struct cmsghdr))+(len))
76 #endif
77 
78 /** if CMSG_SPACE is not defined on this platform, a workaround */
79 #ifndef CMSG_SPACE
80 #  ifdef _CMSG_HDR_ALIGN
81 #    define CMSG_SPACE(l) (CMSG_ALIGN(l)+_CMSG_HDR_ALIGN(sizeof(struct cmsghdr)))
82 #  else
83 #    define CMSG_SPACE(l) (CMSG_ALIGN(l)+CMSG_ALIGN(sizeof(struct cmsghdr)))
84 #  endif
85 #endif
86 
87 /** The TCP writing query timeout in milliseconds */
88 #define TCP_QUERY_TIMEOUT 120000
89 /** The minimum actual TCP timeout to use, regardless of what we advertise,
90  * in msec */
91 #define TCP_QUERY_TIMEOUT_MINIMUM 200
92 
93 #ifndef NONBLOCKING_IS_BROKEN
94 /** number of UDP reads to perform per read indication from select */
95 #define NUM_UDP_PER_SELECT 100
96 #else
97 #define NUM_UDP_PER_SELECT 1
98 #endif
99 
100 /**
101  * The internal event structure for keeping ub_event info for the event.
102  * Possibly other structures (list, tree) this is part of.
103  */
104 struct internal_event {
105 	/** the comm base */
106 	struct comm_base* base;
107 	/** ub_event event type */
108 	struct ub_event* ev;
109 };
110 
111 /**
112  * Internal base structure, so that every thread has its own events.
113  */
114 struct internal_base {
115 	/** ub_event event_base type. */
116 	struct ub_event_base* base;
117 	/** seconds time pointer points here */
118 	time_t secs;
119 	/** timeval with current time */
120 	struct timeval now;
121 	/** the event used for slow_accept timeouts */
122 	struct ub_event* slow_accept;
123 	/** true if slow_accept is enabled */
124 	int slow_accept_enabled;
125 };
126 
127 /**
128  * Internal timer structure, to store timer event in.
129  */
130 struct internal_timer {
131 	/** the super struct from which derived */
132 	struct comm_timer super;
133 	/** the comm base */
134 	struct comm_base* base;
135 	/** ub_event event type */
136 	struct ub_event* ev;
137 	/** is timer enabled */
138 	uint8_t enabled;
139 };
140 
141 /**
142  * Internal signal structure, to store signal event in.
143  */
144 struct internal_signal {
145 	/** ub_event event type */
146 	struct ub_event* ev;
147 	/** next in signal list */
148 	struct internal_signal* next;
149 };
150 
151 /** create a tcp handler with a parent */
152 static struct comm_point* comm_point_create_tcp_handler(
153 	struct comm_base *base, struct comm_point* parent, size_t bufsize,
154 	struct sldns_buffer* spoolbuf, comm_point_callback_type* callback,
155 	void* callback_arg);
156 
157 /* -------- End of local definitions -------- */
158 
159 struct comm_base*
160 comm_base_create(int sigs)
161 {
162 	struct comm_base* b = (struct comm_base*)calloc(1,
163 		sizeof(struct comm_base));
164 	const char *evnm="event", *evsys="", *evmethod="";
165 
166 	if(!b)
167 		return NULL;
168 	b->eb = (struct internal_base*)calloc(1, sizeof(struct internal_base));
169 	if(!b->eb) {
170 		free(b);
171 		return NULL;
172 	}
173 	b->eb->base = ub_default_event_base(sigs, &b->eb->secs, &b->eb->now);
174 	if(!b->eb->base) {
175 		free(b->eb);
176 		free(b);
177 		return NULL;
178 	}
179 	ub_comm_base_now(b);
180 	ub_get_event_sys(b->eb->base, &evnm, &evsys, &evmethod);
181 	verbose(VERB_ALGO, "%s %s uses %s method.", evnm, evsys, evmethod);
182 	return b;
183 }
184 
185 struct comm_base*
186 comm_base_create_event(struct ub_event_base* base)
187 {
188 	struct comm_base* b = (struct comm_base*)calloc(1,
189 		sizeof(struct comm_base));
190 	if(!b)
191 		return NULL;
192 	b->eb = (struct internal_base*)calloc(1, sizeof(struct internal_base));
193 	if(!b->eb) {
194 		free(b);
195 		return NULL;
196 	}
197 	b->eb->base = base;
198 	ub_comm_base_now(b);
199 	return b;
200 }
201 
202 void
203 comm_base_delete(struct comm_base* b)
204 {
205 	if(!b)
206 		return;
207 	if(b->eb->slow_accept_enabled) {
208 		if(ub_event_del(b->eb->slow_accept) != 0) {
209 			log_err("could not event_del slow_accept");
210 		}
211 		ub_event_free(b->eb->slow_accept);
212 	}
213 	ub_event_base_free(b->eb->base);
214 	b->eb->base = NULL;
215 	free(b->eb);
216 	free(b);
217 }
218 
219 void
220 comm_base_delete_no_base(struct comm_base* b)
221 {
222 	if(!b)
223 		return;
224 	if(b->eb->slow_accept_enabled) {
225 		if(ub_event_del(b->eb->slow_accept) != 0) {
226 			log_err("could not event_del slow_accept");
227 		}
228 		ub_event_free(b->eb->slow_accept);
229 	}
230 	b->eb->base = NULL;
231 	free(b->eb);
232 	free(b);
233 }
234 
235 void
236 comm_base_timept(struct comm_base* b, time_t** tt, struct timeval** tv)
237 {
238 	*tt = &b->eb->secs;
239 	*tv = &b->eb->now;
240 }
241 
242 void
243 comm_base_dispatch(struct comm_base* b)
244 {
245 	int retval;
246 	retval = ub_event_base_dispatch(b->eb->base);
247 	if(retval < 0) {
248 		fatal_exit("event_dispatch returned error %d, "
249 			"errno is %s", retval, strerror(errno));
250 	}
251 }
252 
253 void comm_base_exit(struct comm_base* b)
254 {
255 	if(ub_event_base_loopexit(b->eb->base) != 0) {
256 		log_err("Could not loopexit");
257 	}
258 }
259 
260 void comm_base_set_slow_accept_handlers(struct comm_base* b,
261 	void (*stop_acc)(void*), void (*start_acc)(void*), void* arg)
262 {
263 	b->stop_accept = stop_acc;
264 	b->start_accept = start_acc;
265 	b->cb_arg = arg;
266 }
267 
268 struct ub_event_base* comm_base_internal(struct comm_base* b)
269 {
270 	return b->eb->base;
271 }
272 
273 /** see if errno for udp has to be logged or not uses globals */
274 static int
275 udp_send_errno_needs_log(struct sockaddr* addr, socklen_t addrlen)
276 {
277 	/* do not log transient errors (unless high verbosity) */
278 #if defined(ENETUNREACH) || defined(EHOSTDOWN) || defined(EHOSTUNREACH) || defined(ENETDOWN)
279 	switch(errno) {
280 #  ifdef ENETUNREACH
281 		case ENETUNREACH:
282 #  endif
283 #  ifdef EHOSTDOWN
284 		case EHOSTDOWN:
285 #  endif
286 #  ifdef EHOSTUNREACH
287 		case EHOSTUNREACH:
288 #  endif
289 #  ifdef ENETDOWN
290 		case ENETDOWN:
291 #  endif
292 			if(verbosity < VERB_ALGO)
293 				return 0;
294 		default:
295 			break;
296 	}
297 #endif
298 	/* permission denied is gotten for every send if the
299 	 * network is disconnected (on some OS), squelch it */
300 	if( ((errno == EPERM)
301 #  ifdef EADDRNOTAVAIL
302 		/* 'Cannot assign requested address' also when disconnected */
303 		|| (errno == EADDRNOTAVAIL)
304 #  endif
305 		) && verbosity < VERB_DETAIL)
306 		return 0;
307 #  ifdef EADDRINUSE
308 	/* If SO_REUSEADDR is set, we could try to connect to the same server
309 	 * from the same source port twice. */
310 	if(errno == EADDRINUSE && verbosity < VERB_DETAIL)
311 		return 0;
312 #  endif
313 	/* squelch errors where people deploy AAAA ::ffff:bla for
314 	 * authority servers, which we try for intranets. */
315 	if(errno == EINVAL && addr_is_ip4mapped(
316 		(struct sockaddr_storage*)addr, addrlen) &&
317 		verbosity < VERB_DETAIL)
318 		return 0;
319 	/* SO_BROADCAST sockopt can give access to 255.255.255.255,
320 	 * but a dns cache does not need it. */
321 	if(errno == EACCES && addr_is_broadcast(
322 		(struct sockaddr_storage*)addr, addrlen) &&
323 		verbosity < VERB_DETAIL)
324 		return 0;
325 	return 1;
326 }
327 
328 int tcp_connect_errno_needs_log(struct sockaddr* addr, socklen_t addrlen)
329 {
330 	return udp_send_errno_needs_log(addr, addrlen);
331 }
332 
333 /* send a UDP reply */
334 int
335 comm_point_send_udp_msg(struct comm_point *c, sldns_buffer* packet,
336 	struct sockaddr* addr, socklen_t addrlen)
337 {
338 	ssize_t sent;
339 	log_assert(c->fd != -1);
340 #ifdef UNBOUND_DEBUG
341 	if(sldns_buffer_remaining(packet) == 0)
342 		log_err("error: send empty UDP packet");
343 #endif
344 	log_assert(addr && addrlen > 0);
345 	sent = sendto(c->fd, (void*)sldns_buffer_begin(packet),
346 		sldns_buffer_remaining(packet), 0,
347 		addr, addrlen);
348 	if(sent == -1) {
349 		/* try again and block, waiting for IO to complete,
350 		 * we want to send the answer, and we will wait for
351 		 * the ethernet interface buffer to have space. */
352 #ifndef USE_WINSOCK
353 		if(errno == EAGAIN ||
354 #  ifdef EWOULDBLOCK
355 			errno == EWOULDBLOCK ||
356 #  endif
357 			errno == ENOBUFS) {
358 #else
359 		if(WSAGetLastError() == WSAEINPROGRESS ||
360 			WSAGetLastError() == WSAENOBUFS ||
361 			WSAGetLastError() == WSAEWOULDBLOCK) {
362 #endif
363 			int e;
364 			fd_set_block(c->fd);
365 			sent = sendto(c->fd, (void*)sldns_buffer_begin(packet),
366 				sldns_buffer_remaining(packet), 0,
367 				addr, addrlen);
368 			e = errno;
369 			fd_set_nonblock(c->fd);
370 			errno = e;
371 		}
372 	}
373 	if(sent == -1) {
374 		if(!udp_send_errno_needs_log(addr, addrlen))
375 			return 0;
376 #ifndef USE_WINSOCK
377 		verbose(VERB_OPS, "sendto failed: %s", strerror(errno));
378 #else
379 		verbose(VERB_OPS, "sendto failed: %s",
380 			wsa_strerror(WSAGetLastError()));
381 #endif
382 		log_addr(VERB_OPS, "remote address is",
383 			(struct sockaddr_storage*)addr, addrlen);
384 		return 0;
385 	} else if((size_t)sent != sldns_buffer_remaining(packet)) {
386 		log_err("sent %d in place of %d bytes",
387 			(int)sent, (int)sldns_buffer_remaining(packet));
388 		return 0;
389 	}
390 	return 1;
391 }
392 
393 #if defined(AF_INET6) && defined(IPV6_PKTINFO) && (defined(HAVE_RECVMSG) || defined(HAVE_SENDMSG))
394 /** print debug ancillary info */
395 static void p_ancil(const char* str, struct comm_reply* r)
396 {
397 	if(r->srctype != 4 && r->srctype != 6) {
398 		log_info("%s: unknown srctype %d", str, r->srctype);
399 		return;
400 	}
401 	if(r->srctype == 6) {
402 		char buf[1024];
403 		if(inet_ntop(AF_INET6, &r->pktinfo.v6info.ipi6_addr,
404 			buf, (socklen_t)sizeof(buf)) == 0) {
405 			(void)strlcpy(buf, "(inet_ntop error)", sizeof(buf));
406 		}
407 		buf[sizeof(buf)-1]=0;
408 		log_info("%s: %s %d", str, buf, r->pktinfo.v6info.ipi6_ifindex);
409 	} else if(r->srctype == 4) {
410 #ifdef IP_PKTINFO
411 		char buf1[1024], buf2[1024];
412 		if(inet_ntop(AF_INET, &r->pktinfo.v4info.ipi_addr,
413 			buf1, (socklen_t)sizeof(buf1)) == 0) {
414 			(void)strlcpy(buf1, "(inet_ntop error)", sizeof(buf1));
415 		}
416 		buf1[sizeof(buf1)-1]=0;
417 #ifdef HAVE_STRUCT_IN_PKTINFO_IPI_SPEC_DST
418 		if(inet_ntop(AF_INET, &r->pktinfo.v4info.ipi_spec_dst,
419 			buf2, (socklen_t)sizeof(buf2)) == 0) {
420 			(void)strlcpy(buf2, "(inet_ntop error)", sizeof(buf2));
421 		}
422 		buf2[sizeof(buf2)-1]=0;
423 #else
424 		buf2[0]=0;
425 #endif
426 		log_info("%s: %d %s %s", str, r->pktinfo.v4info.ipi_ifindex,
427 			buf1, buf2);
428 #elif defined(IP_RECVDSTADDR)
429 		char buf1[1024];
430 		if(inet_ntop(AF_INET, &r->pktinfo.v4addr,
431 			buf1, (socklen_t)sizeof(buf1)) == 0) {
432 			(void)strlcpy(buf1, "(inet_ntop error)", sizeof(buf1));
433 		}
434 		buf1[sizeof(buf1)-1]=0;
435 		log_info("%s: %s", str, buf1);
436 #endif /* IP_PKTINFO or PI_RECVDSTDADDR */
437 	}
438 }
439 #endif /* AF_INET6 && IPV6_PKTINFO && HAVE_RECVMSG||HAVE_SENDMSG */
440 
441 /** send a UDP reply over specified interface*/
442 static int
443 comm_point_send_udp_msg_if(struct comm_point *c, sldns_buffer* packet,
444 	struct sockaddr* addr, socklen_t addrlen, struct comm_reply* r)
445 {
446 #if defined(AF_INET6) && defined(IPV6_PKTINFO) && defined(HAVE_SENDMSG)
447 	ssize_t sent;
448 	struct msghdr msg;
449 	struct iovec iov[1];
450 	char control[256];
451 #ifndef S_SPLINT_S
452 	struct cmsghdr *cmsg;
453 #endif /* S_SPLINT_S */
454 
455 	log_assert(c->fd != -1);
456 #ifdef UNBOUND_DEBUG
457 	if(sldns_buffer_remaining(packet) == 0)
458 		log_err("error: send empty UDP packet");
459 #endif
460 	log_assert(addr && addrlen > 0);
461 
462 	msg.msg_name = addr;
463 	msg.msg_namelen = addrlen;
464 	iov[0].iov_base = sldns_buffer_begin(packet);
465 	iov[0].iov_len = sldns_buffer_remaining(packet);
466 	msg.msg_iov = iov;
467 	msg.msg_iovlen = 1;
468 	msg.msg_control = control;
469 #ifndef S_SPLINT_S
470 	msg.msg_controllen = sizeof(control);
471 #endif /* S_SPLINT_S */
472 	msg.msg_flags = 0;
473 
474 #ifndef S_SPLINT_S
475 	cmsg = CMSG_FIRSTHDR(&msg);
476 	if(r->srctype == 4) {
477 #ifdef IP_PKTINFO
478 		void* cmsg_data;
479 		msg.msg_controllen = CMSG_SPACE(sizeof(struct in_pktinfo));
480 		log_assert(msg.msg_controllen <= sizeof(control));
481 		cmsg->cmsg_level = IPPROTO_IP;
482 		cmsg->cmsg_type = IP_PKTINFO;
483 		memmove(CMSG_DATA(cmsg), &r->pktinfo.v4info,
484 			sizeof(struct in_pktinfo));
485 		/* unset the ifindex to not bypass the routing tables */
486 		cmsg_data = CMSG_DATA(cmsg);
487 		((struct in_pktinfo *) cmsg_data)->ipi_ifindex = 0;
488 		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_pktinfo));
489 #elif defined(IP_SENDSRCADDR)
490 		msg.msg_controllen = CMSG_SPACE(sizeof(struct in_addr));
491 		log_assert(msg.msg_controllen <= sizeof(control));
492 		cmsg->cmsg_level = IPPROTO_IP;
493 		cmsg->cmsg_type = IP_SENDSRCADDR;
494 		memmove(CMSG_DATA(cmsg), &r->pktinfo.v4addr,
495 			sizeof(struct in_addr));
496 		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in_addr));
497 #else
498 		verbose(VERB_ALGO, "no IP_PKTINFO or IP_SENDSRCADDR");
499 		msg.msg_control = NULL;
500 #endif /* IP_PKTINFO or IP_SENDSRCADDR */
501 	} else if(r->srctype == 6) {
502 		void* cmsg_data;
503 		msg.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
504 		log_assert(msg.msg_controllen <= sizeof(control));
505 		cmsg->cmsg_level = IPPROTO_IPV6;
506 		cmsg->cmsg_type = IPV6_PKTINFO;
507 		memmove(CMSG_DATA(cmsg), &r->pktinfo.v6info,
508 			sizeof(struct in6_pktinfo));
509 		/* unset the ifindex to not bypass the routing tables */
510 		cmsg_data = CMSG_DATA(cmsg);
511 		((struct in6_pktinfo *) cmsg_data)->ipi6_ifindex = 0;
512 		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
513 	} else {
514 		/* try to pass all 0 to use default route */
515 		msg.msg_controllen = CMSG_SPACE(sizeof(struct in6_pktinfo));
516 		log_assert(msg.msg_controllen <= sizeof(control));
517 		cmsg->cmsg_level = IPPROTO_IPV6;
518 		cmsg->cmsg_type = IPV6_PKTINFO;
519 		memset(CMSG_DATA(cmsg), 0, sizeof(struct in6_pktinfo));
520 		cmsg->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
521 	}
522 #endif /* S_SPLINT_S */
523 	if(verbosity >= VERB_ALGO)
524 		p_ancil("send_udp over interface", r);
525 	sent = sendmsg(c->fd, &msg, 0);
526 	if(sent == -1) {
527 		/* try again and block, waiting for IO to complete,
528 		 * we want to send the answer, and we will wait for
529 		 * the ethernet interface buffer to have space. */
530 #ifndef USE_WINSOCK
531 		if(errno == EAGAIN ||
532 #  ifdef EWOULDBLOCK
533 			errno == EWOULDBLOCK ||
534 #  endif
535 			errno == ENOBUFS) {
536 #else
537 		if(WSAGetLastError() == WSAEINPROGRESS ||
538 			WSAGetLastError() == WSAENOBUFS ||
539 			WSAGetLastError() == WSAEWOULDBLOCK) {
540 #endif
541 			int e;
542 			fd_set_block(c->fd);
543 			sent = sendmsg(c->fd, &msg, 0);
544 			e = errno;
545 			fd_set_nonblock(c->fd);
546 			errno = e;
547 		}
548 	}
549 	if(sent == -1) {
550 		if(!udp_send_errno_needs_log(addr, addrlen))
551 			return 0;
552 		verbose(VERB_OPS, "sendmsg failed: %s", strerror(errno));
553 		log_addr(VERB_OPS, "remote address is",
554 			(struct sockaddr_storage*)addr, addrlen);
555 #ifdef __NetBSD__
556 		/* netbsd 7 has IP_PKTINFO for recv but not send */
557 		if(errno == EINVAL && r->srctype == 4)
558 			log_err("sendmsg: No support for sendmsg(IP_PKTINFO). "
559 				"Please disable interface-automatic");
560 #endif
561 		return 0;
562 	} else if((size_t)sent != sldns_buffer_remaining(packet)) {
563 		log_err("sent %d in place of %d bytes",
564 			(int)sent, (int)sldns_buffer_remaining(packet));
565 		return 0;
566 	}
567 	return 1;
568 #else
569 	(void)c;
570 	(void)packet;
571 	(void)addr;
572 	(void)addrlen;
573 	(void)r;
574 	log_err("sendmsg: IPV6_PKTINFO not supported");
575 	return 0;
576 #endif /* AF_INET6 && IPV6_PKTINFO && HAVE_SENDMSG */
577 }
578 
579 void
580 comm_point_udp_ancil_callback(int fd, short event, void* arg)
581 {
582 #if defined(AF_INET6) && defined(IPV6_PKTINFO) && defined(HAVE_RECVMSG)
583 	struct comm_reply rep;
584 	struct msghdr msg;
585 	struct iovec iov[1];
586 	ssize_t rcv;
587 	char ancil[256];
588 	int i;
589 #ifndef S_SPLINT_S
590 	struct cmsghdr* cmsg;
591 #endif /* S_SPLINT_S */
592 
593 	rep.c = (struct comm_point*)arg;
594 	log_assert(rep.c->type == comm_udp);
595 
596 	if(!(event&UB_EV_READ))
597 		return;
598 	log_assert(rep.c && rep.c->buffer && rep.c->fd == fd);
599 	ub_comm_base_now(rep.c->ev->base);
600 	for(i=0; i<NUM_UDP_PER_SELECT; i++) {
601 		sldns_buffer_clear(rep.c->buffer);
602 		rep.addrlen = (socklen_t)sizeof(rep.addr);
603 		log_assert(fd != -1);
604 		log_assert(sldns_buffer_remaining(rep.c->buffer) > 0);
605 		msg.msg_name = &rep.addr;
606 		msg.msg_namelen = (socklen_t)sizeof(rep.addr);
607 		iov[0].iov_base = sldns_buffer_begin(rep.c->buffer);
608 		iov[0].iov_len = sldns_buffer_remaining(rep.c->buffer);
609 		msg.msg_iov = iov;
610 		msg.msg_iovlen = 1;
611 		msg.msg_control = ancil;
612 #ifndef S_SPLINT_S
613 		msg.msg_controllen = sizeof(ancil);
614 #endif /* S_SPLINT_S */
615 		msg.msg_flags = 0;
616 		rcv = recvmsg(fd, &msg, 0);
617 		if(rcv == -1) {
618 			if(errno != EAGAIN && errno != EINTR) {
619 				log_err("recvmsg failed: %s", strerror(errno));
620 			}
621 			return;
622 		}
623 		rep.addrlen = msg.msg_namelen;
624 		sldns_buffer_skip(rep.c->buffer, rcv);
625 		sldns_buffer_flip(rep.c->buffer);
626 		rep.srctype = 0;
627 #ifndef S_SPLINT_S
628 		for(cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
629 			cmsg = CMSG_NXTHDR(&msg, cmsg)) {
630 			if( cmsg->cmsg_level == IPPROTO_IPV6 &&
631 				cmsg->cmsg_type == IPV6_PKTINFO) {
632 				rep.srctype = 6;
633 				memmove(&rep.pktinfo.v6info, CMSG_DATA(cmsg),
634 					sizeof(struct in6_pktinfo));
635 				break;
636 #ifdef IP_PKTINFO
637 			} else if( cmsg->cmsg_level == IPPROTO_IP &&
638 				cmsg->cmsg_type == IP_PKTINFO) {
639 				rep.srctype = 4;
640 				memmove(&rep.pktinfo.v4info, CMSG_DATA(cmsg),
641 					sizeof(struct in_pktinfo));
642 				break;
643 #elif defined(IP_RECVDSTADDR)
644 			} else if( cmsg->cmsg_level == IPPROTO_IP &&
645 				cmsg->cmsg_type == IP_RECVDSTADDR) {
646 				rep.srctype = 4;
647 				memmove(&rep.pktinfo.v4addr, CMSG_DATA(cmsg),
648 					sizeof(struct in_addr));
649 				break;
650 #endif /* IP_PKTINFO or IP_RECVDSTADDR */
651 			}
652 		}
653 		if(verbosity >= VERB_ALGO)
654 			p_ancil("receive_udp on interface", &rep);
655 #endif /* S_SPLINT_S */
656 		fptr_ok(fptr_whitelist_comm_point(rep.c->callback));
657 		if((*rep.c->callback)(rep.c, rep.c->cb_arg, NETEVENT_NOERROR, &rep)) {
658 			/* send back immediate reply */
659 			(void)comm_point_send_udp_msg_if(rep.c, rep.c->buffer,
660 				(struct sockaddr*)&rep.addr, rep.addrlen, &rep);
661 		}
662 		if(!rep.c || rep.c->fd == -1) /* commpoint closed */
663 			break;
664 	}
665 #else
666 	(void)fd;
667 	(void)event;
668 	(void)arg;
669 	fatal_exit("recvmsg: No support for IPV6_PKTINFO; IP_PKTINFO or IP_RECVDSTADDR. "
670 		"Please disable interface-automatic");
671 #endif /* AF_INET6 && IPV6_PKTINFO && HAVE_RECVMSG */
672 }
673 
674 void
675 comm_point_udp_callback(int fd, short event, void* arg)
676 {
677 	struct comm_reply rep;
678 	ssize_t rcv;
679 	int i;
680 	struct sldns_buffer *buffer;
681 
682 	rep.c = (struct comm_point*)arg;
683 	log_assert(rep.c->type == comm_udp);
684 
685 	if(!(event&UB_EV_READ))
686 		return;
687 	log_assert(rep.c && rep.c->buffer && rep.c->fd == fd);
688 	ub_comm_base_now(rep.c->ev->base);
689 	for(i=0; i<NUM_UDP_PER_SELECT; i++) {
690 		sldns_buffer_clear(rep.c->buffer);
691 		rep.addrlen = (socklen_t)sizeof(rep.addr);
692 		log_assert(fd != -1);
693 		log_assert(sldns_buffer_remaining(rep.c->buffer) > 0);
694 		rcv = recvfrom(fd, (void*)sldns_buffer_begin(rep.c->buffer),
695 			sldns_buffer_remaining(rep.c->buffer), 0,
696 			(struct sockaddr*)&rep.addr, &rep.addrlen);
697 		if(rcv == -1) {
698 #ifndef USE_WINSOCK
699 			if(errno != EAGAIN && errno != EINTR)
700 				log_err("recvfrom %d failed: %s",
701 					fd, strerror(errno));
702 #else
703 			if(WSAGetLastError() != WSAEINPROGRESS &&
704 				WSAGetLastError() != WSAECONNRESET &&
705 				WSAGetLastError()!= WSAEWOULDBLOCK)
706 				log_err("recvfrom failed: %s",
707 					wsa_strerror(WSAGetLastError()));
708 #endif
709 			return;
710 		}
711 		sldns_buffer_skip(rep.c->buffer, rcv);
712 		sldns_buffer_flip(rep.c->buffer);
713 		rep.srctype = 0;
714 		fptr_ok(fptr_whitelist_comm_point(rep.c->callback));
715 		if((*rep.c->callback)(rep.c, rep.c->cb_arg, NETEVENT_NOERROR, &rep)) {
716 			/* send back immediate reply */
717 #ifdef USE_DNSCRYPT
718 			buffer = rep.c->dnscrypt_buffer;
719 #else
720 			buffer = rep.c->buffer;
721 #endif
722 			(void)comm_point_send_udp_msg(rep.c, buffer,
723 				(struct sockaddr*)&rep.addr, rep.addrlen);
724 		}
725 		if(!rep.c || rep.c->fd != fd) /* commpoint closed to -1 or reused for
726 		another UDP port. Note rep.c cannot be reused with TCP fd. */
727 			break;
728 	}
729 }
730 
731 /** Use a new tcp handler for new query fd, set to read query */
732 static void
733 setup_tcp_handler(struct comm_point* c, int fd, int cur, int max)
734 {
735 	int handler_usage;
736 	log_assert(c->type == comm_tcp);
737 	log_assert(c->fd == -1);
738 	sldns_buffer_clear(c->buffer);
739 #ifdef USE_DNSCRYPT
740 	if (c->dnscrypt)
741 		sldns_buffer_clear(c->dnscrypt_buffer);
742 #endif
743 	c->tcp_is_reading = 1;
744 	c->tcp_byte_count = 0;
745 	/* if more than half the tcp handlers are in use, use a shorter
746 	 * timeout for this TCP connection, we need to make space for
747 	 * other connections to be able to get attention */
748 	/* If > 50% TCP handler structures in use, set timeout to 1/100th
749 	 * 	configured value.
750 	 * If > 65%TCP handler structures in use, set to 1/500th configured
751 	 * 	value.
752 	 * If > 80% TCP handler structures in use, set to 0.
753 	 *
754 	 * If the timeout to use falls below 200 milliseconds, an actual
755 	 * timeout of 200ms is used.
756 	 */
757 	handler_usage = (cur * 100) / max;
758 	if(handler_usage > 50 && handler_usage <= 65)
759 		c->tcp_timeout_msec /= 100;
760 	else if (handler_usage > 65 && handler_usage <= 80)
761 		c->tcp_timeout_msec /= 500;
762 	else if (handler_usage > 80)
763 		c->tcp_timeout_msec = 0;
764 	comm_point_start_listening(c, fd,
765 		c->tcp_timeout_msec < TCP_QUERY_TIMEOUT_MINIMUM
766 			? TCP_QUERY_TIMEOUT_MINIMUM
767 			: c->tcp_timeout_msec);
768 }
769 
770 void comm_base_handle_slow_accept(int ATTR_UNUSED(fd),
771 	short ATTR_UNUSED(event), void* arg)
772 {
773 	struct comm_base* b = (struct comm_base*)arg;
774 	/* timeout for the slow accept, re-enable accepts again */
775 	if(b->start_accept) {
776 		verbose(VERB_ALGO, "wait is over, slow accept disabled");
777 		fptr_ok(fptr_whitelist_start_accept(b->start_accept));
778 		(*b->start_accept)(b->cb_arg);
779 		b->eb->slow_accept_enabled = 0;
780 	}
781 }
782 
783 int comm_point_perform_accept(struct comm_point* c,
784 	struct sockaddr_storage* addr, socklen_t* addrlen)
785 {
786 	int new_fd;
787 	*addrlen = (socklen_t)sizeof(*addr);
788 #ifndef HAVE_ACCEPT4
789 	new_fd = accept(c->fd, (struct sockaddr*)addr, addrlen);
790 #else
791 	/* SOCK_NONBLOCK saves extra calls to fcntl for the same result */
792 	new_fd = accept4(c->fd, (struct sockaddr*)addr, addrlen, SOCK_NONBLOCK);
793 #endif
794 	if(new_fd == -1) {
795 #ifndef USE_WINSOCK
796 		/* EINTR is signal interrupt. others are closed connection. */
797 		if(	errno == EINTR || errno == EAGAIN
798 #ifdef EWOULDBLOCK
799 			|| errno == EWOULDBLOCK
800 #endif
801 #ifdef ECONNABORTED
802 			|| errno == ECONNABORTED
803 #endif
804 #ifdef EPROTO
805 			|| errno == EPROTO
806 #endif /* EPROTO */
807 			)
808 			return -1;
809 #if defined(ENFILE) && defined(EMFILE)
810 		if(errno == ENFILE || errno == EMFILE) {
811 			/* out of file descriptors, likely outside of our
812 			 * control. stop accept() calls for some time */
813 			if(c->ev->base->stop_accept) {
814 				struct comm_base* b = c->ev->base;
815 				struct timeval tv;
816 				verbose(VERB_ALGO, "out of file descriptors: "
817 					"slow accept");
818 				b->eb->slow_accept_enabled = 1;
819 				fptr_ok(fptr_whitelist_stop_accept(
820 					b->stop_accept));
821 				(*b->stop_accept)(b->cb_arg);
822 				/* set timeout, no mallocs */
823 				tv.tv_sec = NETEVENT_SLOW_ACCEPT_TIME/1000;
824 				tv.tv_usec = (NETEVENT_SLOW_ACCEPT_TIME%1000)*1000;
825 				b->eb->slow_accept = ub_event_new(b->eb->base,
826 					-1, UB_EV_TIMEOUT,
827 					comm_base_handle_slow_accept, b);
828 				if(b->eb->slow_accept == NULL) {
829 					/* we do not want to log here, because
830 					 * that would spam the logfiles.
831 					 * error: "event_base_set failed." */
832 				}
833 				else if(ub_event_add(b->eb->slow_accept, &tv)
834 					!= 0) {
835 					/* we do not want to log here,
836 					 * error: "event_add failed." */
837 				}
838 			}
839 			return -1;
840 		}
841 #endif
842 		log_err_addr("accept failed", strerror(errno), addr, *addrlen);
843 #else /* USE_WINSOCK */
844 		if(WSAGetLastError() == WSAEINPROGRESS ||
845 			WSAGetLastError() == WSAECONNRESET)
846 			return -1;
847 		if(WSAGetLastError() == WSAEWOULDBLOCK) {
848 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
849 			return -1;
850 		}
851 		log_err_addr("accept failed", wsa_strerror(WSAGetLastError()),
852 			addr, *addrlen);
853 #endif
854 		return -1;
855 	}
856 	if(c->tcp_conn_limit && c->type == comm_tcp_accept) {
857 		c->tcl_addr = tcl_addr_lookup(c->tcp_conn_limit, addr, *addrlen);
858 		if(!tcl_new_connection(c->tcl_addr)) {
859 			if(verbosity >= 3)
860 				log_err_addr("accept rejected",
861 				"connection limit exceeded", addr, *addrlen);
862 			close(new_fd);
863 			return -1;
864 		}
865 	}
866 #ifndef HAVE_ACCEPT4
867 	fd_set_nonblock(new_fd);
868 #endif
869 	return new_fd;
870 }
871 
872 #ifdef USE_WINSOCK
873 static long win_bio_cb(BIO *b, int oper, const char* ATTR_UNUSED(argp),
874         int ATTR_UNUSED(argi), long argl, long retvalue)
875 {
876 	int wsa_err = WSAGetLastError(); /* store errcode before it is gone */
877 	verbose(VERB_ALGO, "bio_cb %d, %s %s %s", oper,
878 		(oper&BIO_CB_RETURN)?"return":"before",
879 		(oper&BIO_CB_READ)?"read":((oper&BIO_CB_WRITE)?"write":"other"),
880 		wsa_err==WSAEWOULDBLOCK?"wsawb":"");
881 	/* on windows, check if previous operation caused EWOULDBLOCK */
882 	if( (oper == (BIO_CB_READ|BIO_CB_RETURN) && argl == 0) ||
883 		(oper == (BIO_CB_GETS|BIO_CB_RETURN) && argl == 0)) {
884 		if(wsa_err == WSAEWOULDBLOCK)
885 			ub_winsock_tcp_wouldblock((struct ub_event*)
886 				BIO_get_callback_arg(b), UB_EV_READ);
887 	}
888 	if( (oper == (BIO_CB_WRITE|BIO_CB_RETURN) && argl == 0) ||
889 		(oper == (BIO_CB_PUTS|BIO_CB_RETURN) && argl == 0)) {
890 		if(wsa_err == WSAEWOULDBLOCK)
891 			ub_winsock_tcp_wouldblock((struct ub_event*)
892 				BIO_get_callback_arg(b), UB_EV_WRITE);
893 	}
894 	/* return original return value */
895 	return retvalue;
896 }
897 
898 /** set win bio callbacks for nonblocking operations */
899 void
900 comm_point_tcp_win_bio_cb(struct comm_point* c, void* thessl)
901 {
902 	SSL* ssl = (SSL*)thessl;
903 	/* set them both just in case, but usually they are the same BIO */
904 	BIO_set_callback(SSL_get_rbio(ssl), &win_bio_cb);
905 	BIO_set_callback_arg(SSL_get_rbio(ssl), (char*)c->ev->ev);
906 	BIO_set_callback(SSL_get_wbio(ssl), &win_bio_cb);
907 	BIO_set_callback_arg(SSL_get_wbio(ssl), (char*)c->ev->ev);
908 }
909 #endif
910 
911 void
912 comm_point_tcp_accept_callback(int fd, short event, void* arg)
913 {
914 	struct comm_point* c = (struct comm_point*)arg, *c_hdl;
915 	int new_fd;
916 	log_assert(c->type == comm_tcp_accept);
917 	if(!(event & UB_EV_READ)) {
918 		log_info("ignoring tcp accept event %d", (int)event);
919 		return;
920 	}
921 	ub_comm_base_now(c->ev->base);
922 	/* find free tcp handler. */
923 	if(!c->tcp_free) {
924 		log_warn("accepted too many tcp, connections full");
925 		return;
926 	}
927 	/* accept incoming connection. */
928 	c_hdl = c->tcp_free;
929 	/* clear leftover flags from previous use, and then set the
930 	 * correct event base for the event structure for libevent */
931 	ub_event_free(c_hdl->ev->ev);
932 	c_hdl->ev->ev = ub_event_new(c_hdl->ev->base->eb->base, -1, UB_EV_PERSIST | UB_EV_READ | UB_EV_TIMEOUT, comm_point_tcp_handle_callback, c_hdl);
933 	if(!c_hdl->ev->ev) {
934 		log_warn("could not ub_event_new, dropped tcp");
935 		return;
936 	}
937 	log_assert(fd != -1);
938 	(void)fd;
939 	new_fd = comm_point_perform_accept(c, &c_hdl->repinfo.addr,
940 		&c_hdl->repinfo.addrlen);
941 	if(new_fd == -1)
942 		return;
943 	if(c->ssl) {
944 		c_hdl->ssl = incoming_ssl_fd(c->ssl, new_fd);
945 		if(!c_hdl->ssl) {
946 			c_hdl->fd = new_fd;
947 			comm_point_close(c_hdl);
948 			return;
949 		}
950 		c_hdl->ssl_shake_state = comm_ssl_shake_read;
951 #ifdef USE_WINSOCK
952 		comm_point_tcp_win_bio_cb(c_hdl, c_hdl->ssl);
953 #endif
954 	}
955 
956 	/* grab the tcp handler buffers */
957 	c->cur_tcp_count++;
958 	c->tcp_free = c_hdl->tcp_free;
959 	if(!c->tcp_free) {
960 		/* stop accepting incoming queries for now. */
961 		comm_point_stop_listening(c);
962 	}
963 	setup_tcp_handler(c_hdl, new_fd, c->cur_tcp_count, c->max_tcp_count);
964 }
965 
966 /** Make tcp handler free for next assignment */
967 static void
968 reclaim_tcp_handler(struct comm_point* c)
969 {
970 	log_assert(c->type == comm_tcp);
971 	if(c->ssl) {
972 #ifdef HAVE_SSL
973 		SSL_shutdown(c->ssl);
974 		SSL_free(c->ssl);
975 		c->ssl = NULL;
976 #endif
977 	}
978 	comm_point_close(c);
979 	if(c->tcp_parent) {
980 		c->tcp_parent->cur_tcp_count--;
981 		c->tcp_free = c->tcp_parent->tcp_free;
982 		c->tcp_parent->tcp_free = c;
983 		if(!c->tcp_free) {
984 			/* re-enable listening on accept socket */
985 			comm_point_start_listening(c->tcp_parent, -1, -1);
986 		}
987 	}
988 }
989 
990 /** do the callback when writing is done */
991 static void
992 tcp_callback_writer(struct comm_point* c)
993 {
994 	log_assert(c->type == comm_tcp);
995 	sldns_buffer_clear(c->buffer);
996 	if(c->tcp_do_toggle_rw)
997 		c->tcp_is_reading = 1;
998 	c->tcp_byte_count = 0;
999 	/* switch from listening(write) to listening(read) */
1000 	if(c->tcp_req_info) {
1001 		tcp_req_info_handle_writedone(c->tcp_req_info);
1002 	} else {
1003 		comm_point_stop_listening(c);
1004 		comm_point_start_listening(c, -1, -1);
1005 	}
1006 }
1007 
1008 /** do the callback when reading is done */
1009 static void
1010 tcp_callback_reader(struct comm_point* c)
1011 {
1012 	log_assert(c->type == comm_tcp || c->type == comm_local);
1013 	sldns_buffer_flip(c->buffer);
1014 	if(c->tcp_do_toggle_rw)
1015 		c->tcp_is_reading = 0;
1016 	c->tcp_byte_count = 0;
1017 	if(c->tcp_req_info) {
1018 		tcp_req_info_handle_readdone(c->tcp_req_info);
1019 	} else {
1020 		if(c->type == comm_tcp)
1021 			comm_point_stop_listening(c);
1022 		fptr_ok(fptr_whitelist_comm_point(c->callback));
1023 		if( (*c->callback)(c, c->cb_arg, NETEVENT_NOERROR, &c->repinfo) ) {
1024 			comm_point_start_listening(c, -1, c->tcp_timeout_msec);
1025 		}
1026 	}
1027 }
1028 
1029 #ifdef HAVE_SSL
1030 /** log certificate details */
1031 static void
1032 log_cert(unsigned level, const char* str, X509* cert)
1033 {
1034 	BIO* bio;
1035 	char nul = 0;
1036 	char* pp = NULL;
1037 	long len;
1038 	if(verbosity < level) return;
1039 	bio = BIO_new(BIO_s_mem());
1040 	if(!bio) return;
1041 	X509_print_ex(bio, cert, 0, (unsigned long)-1
1042 		^(X509_FLAG_NO_SUBJECT
1043                         |X509_FLAG_NO_ISSUER|X509_FLAG_NO_VALIDITY
1044 			|X509_FLAG_NO_EXTENSIONS|X509_FLAG_NO_AUX
1045 			|X509_FLAG_NO_ATTRIBUTES));
1046 	BIO_write(bio, &nul, (int)sizeof(nul));
1047 	len = BIO_get_mem_data(bio, &pp);
1048 	if(len != 0 && pp) {
1049 		verbose(level, "%s: \n%s", str, pp);
1050 	}
1051 	BIO_free(bio);
1052 }
1053 #endif /* HAVE_SSL */
1054 
1055 /** continue ssl handshake */
1056 #ifdef HAVE_SSL
1057 static int
1058 ssl_handshake(struct comm_point* c)
1059 {
1060 	int r;
1061 	if(c->ssl_shake_state == comm_ssl_shake_hs_read) {
1062 		/* read condition satisfied back to writing */
1063 		comm_point_listen_for_rw(c, 1, 1);
1064 		c->ssl_shake_state = comm_ssl_shake_none;
1065 		return 1;
1066 	}
1067 	if(c->ssl_shake_state == comm_ssl_shake_hs_write) {
1068 		/* write condition satisfied, back to reading */
1069 		comm_point_listen_for_rw(c, 1, 0);
1070 		c->ssl_shake_state = comm_ssl_shake_none;
1071 		return 1;
1072 	}
1073 
1074 	ERR_clear_error();
1075 	r = SSL_do_handshake(c->ssl);
1076 	if(r != 1) {
1077 		int want = SSL_get_error(c->ssl, r);
1078 		if(want == SSL_ERROR_WANT_READ) {
1079 			if(c->ssl_shake_state == comm_ssl_shake_read)
1080 				return 1;
1081 			c->ssl_shake_state = comm_ssl_shake_read;
1082 			comm_point_listen_for_rw(c, 1, 0);
1083 			return 1;
1084 		} else if(want == SSL_ERROR_WANT_WRITE) {
1085 			if(c->ssl_shake_state == comm_ssl_shake_write)
1086 				return 1;
1087 			c->ssl_shake_state = comm_ssl_shake_write;
1088 			comm_point_listen_for_rw(c, 0, 1);
1089 			return 1;
1090 		} else if(r == 0) {
1091 			return 0; /* closed */
1092 		} else if(want == SSL_ERROR_SYSCALL) {
1093 			/* SYSCALL and errno==0 means closed uncleanly */
1094 			if(errno != 0)
1095 				log_err("SSL_handshake syscall: %s",
1096 					strerror(errno));
1097 			return 0;
1098 		} else {
1099 			log_crypto_err("ssl handshake failed");
1100 			log_addr(1, "ssl handshake failed", &c->repinfo.addr,
1101 				c->repinfo.addrlen);
1102 			return 0;
1103 		}
1104 	}
1105 	/* this is where peer verification could take place */
1106 	if((SSL_get_verify_mode(c->ssl)&SSL_VERIFY_PEER)) {
1107 		/* verification */
1108 		if(SSL_get_verify_result(c->ssl) == X509_V_OK) {
1109 			X509* x = SSL_get_peer_certificate(c->ssl);
1110 			if(!x) {
1111 				log_addr(VERB_ALGO, "SSL connection failed: "
1112 					"no certificate",
1113 					&c->repinfo.addr, c->repinfo.addrlen);
1114 				return 0;
1115 			}
1116 			log_cert(VERB_ALGO, "peer certificate", x);
1117 #ifdef HAVE_SSL_GET0_PEERNAME
1118 			if(SSL_get0_peername(c->ssl)) {
1119 				char buf[255];
1120 				snprintf(buf, sizeof(buf), "SSL connection "
1121 					"to %s authenticated",
1122 					SSL_get0_peername(c->ssl));
1123 				log_addr(VERB_ALGO, buf, &c->repinfo.addr,
1124 					c->repinfo.addrlen);
1125 			} else {
1126 #endif
1127 				log_addr(VERB_ALGO, "SSL connection "
1128 					"authenticated", &c->repinfo.addr,
1129 					c->repinfo.addrlen);
1130 #ifdef HAVE_SSL_GET0_PEERNAME
1131 			}
1132 #endif
1133 			X509_free(x);
1134 		} else {
1135 			X509* x = SSL_get_peer_certificate(c->ssl);
1136 			if(x) {
1137 				log_cert(VERB_ALGO, "peer certificate", x);
1138 				X509_free(x);
1139 			}
1140 			log_addr(VERB_ALGO, "SSL connection failed: "
1141 				"failed to authenticate",
1142 				&c->repinfo.addr, c->repinfo.addrlen);
1143 			return 0;
1144 		}
1145 	} else {
1146 		/* unauthenticated, the verify peer flag was not set
1147 		 * in c->ssl when the ssl object was created from ssl_ctx */
1148 		log_addr(VERB_ALGO, "SSL connection", &c->repinfo.addr,
1149 			c->repinfo.addrlen);
1150 	}
1151 
1152 	/* setup listen rw correctly */
1153 	if(c->tcp_is_reading) {
1154 		if(c->ssl_shake_state != comm_ssl_shake_read)
1155 			comm_point_listen_for_rw(c, 1, 0);
1156 	} else {
1157 		comm_point_listen_for_rw(c, 1, 1);
1158 	}
1159 	c->ssl_shake_state = comm_ssl_shake_none;
1160 	return 1;
1161 }
1162 #endif /* HAVE_SSL */
1163 
1164 /** ssl read callback on TCP */
1165 static int
1166 ssl_handle_read(struct comm_point* c)
1167 {
1168 #ifdef HAVE_SSL
1169 	int r;
1170 	if(c->ssl_shake_state != comm_ssl_shake_none) {
1171 		if(!ssl_handshake(c))
1172 			return 0;
1173 		if(c->ssl_shake_state != comm_ssl_shake_none)
1174 			return 1;
1175 	}
1176 	if(c->tcp_byte_count < sizeof(uint16_t)) {
1177 		/* read length bytes */
1178 		ERR_clear_error();
1179 		if((r=SSL_read(c->ssl, (void*)sldns_buffer_at(c->buffer,
1180 			c->tcp_byte_count), (int)(sizeof(uint16_t) -
1181 			c->tcp_byte_count))) <= 0) {
1182 			int want = SSL_get_error(c->ssl, r);
1183 			if(want == SSL_ERROR_ZERO_RETURN) {
1184 				if(c->tcp_req_info)
1185 					return tcp_req_info_handle_read_close(c->tcp_req_info);
1186 				return 0; /* shutdown, closed */
1187 			} else if(want == SSL_ERROR_WANT_READ) {
1188 				ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
1189 				return 1; /* read more later */
1190 			} else if(want == SSL_ERROR_WANT_WRITE) {
1191 				c->ssl_shake_state = comm_ssl_shake_hs_write;
1192 				comm_point_listen_for_rw(c, 0, 1);
1193 				return 1;
1194 			} else if(want == SSL_ERROR_SYSCALL) {
1195 #ifdef ECONNRESET
1196 				if(errno == ECONNRESET && verbosity < 2)
1197 					return 0; /* silence reset by peer */
1198 #endif
1199 				if(errno != 0)
1200 					log_err("SSL_read syscall: %s",
1201 						strerror(errno));
1202 				return 0;
1203 			}
1204 			log_crypto_err("could not SSL_read");
1205 			return 0;
1206 		}
1207 		c->tcp_byte_count += r;
1208 		if(c->tcp_byte_count < sizeof(uint16_t))
1209 			return 1;
1210 		if(sldns_buffer_read_u16_at(c->buffer, 0) >
1211 			sldns_buffer_capacity(c->buffer)) {
1212 			verbose(VERB_QUERY, "ssl: dropped larger than buffer");
1213 			return 0;
1214 		}
1215 		sldns_buffer_set_limit(c->buffer,
1216 			sldns_buffer_read_u16_at(c->buffer, 0));
1217 		if(sldns_buffer_limit(c->buffer) < LDNS_HEADER_SIZE) {
1218 			verbose(VERB_QUERY, "ssl: dropped bogus too short.");
1219 			return 0;
1220 		}
1221 		sldns_buffer_skip(c->buffer, (ssize_t)(c->tcp_byte_count-sizeof(uint16_t)));
1222 		verbose(VERB_ALGO, "Reading ssl tcp query of length %d",
1223 			(int)sldns_buffer_limit(c->buffer));
1224 	}
1225 	if(sldns_buffer_remaining(c->buffer) > 0) {
1226 		ERR_clear_error();
1227 		r = SSL_read(c->ssl, (void*)sldns_buffer_current(c->buffer),
1228 			(int)sldns_buffer_remaining(c->buffer));
1229 		if(r <= 0) {
1230 			int want = SSL_get_error(c->ssl, r);
1231 			if(want == SSL_ERROR_ZERO_RETURN) {
1232 				if(c->tcp_req_info)
1233 					return tcp_req_info_handle_read_close(c->tcp_req_info);
1234 				return 0; /* shutdown, closed */
1235 			} else if(want == SSL_ERROR_WANT_READ) {
1236 				ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
1237 				return 1; /* read more later */
1238 			} else if(want == SSL_ERROR_WANT_WRITE) {
1239 				c->ssl_shake_state = comm_ssl_shake_hs_write;
1240 				comm_point_listen_for_rw(c, 0, 1);
1241 				return 1;
1242 			} else if(want == SSL_ERROR_SYSCALL) {
1243 #ifdef ECONNRESET
1244 				if(errno == ECONNRESET && verbosity < 2)
1245 					return 0; /* silence reset by peer */
1246 #endif
1247 				if(errno != 0)
1248 					log_err("SSL_read syscall: %s",
1249 						strerror(errno));
1250 				return 0;
1251 			}
1252 			log_crypto_err("could not SSL_read");
1253 			return 0;
1254 		}
1255 		sldns_buffer_skip(c->buffer, (ssize_t)r);
1256 	}
1257 	if(sldns_buffer_remaining(c->buffer) <= 0) {
1258 		tcp_callback_reader(c);
1259 	}
1260 	return 1;
1261 #else
1262 	(void)c;
1263 	return 0;
1264 #endif /* HAVE_SSL */
1265 }
1266 
1267 /** ssl write callback on TCP */
1268 static int
1269 ssl_handle_write(struct comm_point* c)
1270 {
1271 #ifdef HAVE_SSL
1272 	int r;
1273 	if(c->ssl_shake_state != comm_ssl_shake_none) {
1274 		if(!ssl_handshake(c))
1275 			return 0;
1276 		if(c->ssl_shake_state != comm_ssl_shake_none)
1277 			return 1;
1278 	}
1279 	/* ignore return, if fails we may simply block */
1280 	(void)SSL_set_mode(c->ssl, SSL_MODE_ENABLE_PARTIAL_WRITE);
1281 	if(c->tcp_byte_count < sizeof(uint16_t)) {
1282 		uint16_t len = htons(sldns_buffer_limit(c->buffer));
1283 		ERR_clear_error();
1284 		if(sizeof(uint16_t)+sldns_buffer_remaining(c->buffer) <
1285 			LDNS_RR_BUF_SIZE) {
1286 			/* combine the tcp length and the query for write,
1287 			 * this emulates writev */
1288 			uint8_t buf[LDNS_RR_BUF_SIZE];
1289 			memmove(buf, &len, sizeof(uint16_t));
1290 			memmove(buf+sizeof(uint16_t),
1291 				sldns_buffer_current(c->buffer),
1292 				sldns_buffer_remaining(c->buffer));
1293 			r = SSL_write(c->ssl, (void*)(buf+c->tcp_byte_count),
1294 				(int)(sizeof(uint16_t)+
1295 				sldns_buffer_remaining(c->buffer)
1296 				- c->tcp_byte_count));
1297 		} else {
1298 			r = SSL_write(c->ssl,
1299 				(void*)(((uint8_t*)&len)+c->tcp_byte_count),
1300 				(int)(sizeof(uint16_t)-c->tcp_byte_count));
1301 		}
1302 		if(r <= 0) {
1303 			int want = SSL_get_error(c->ssl, r);
1304 			if(want == SSL_ERROR_ZERO_RETURN) {
1305 				return 0; /* closed */
1306 			} else if(want == SSL_ERROR_WANT_READ) {
1307 				c->ssl_shake_state = comm_ssl_shake_hs_read;
1308 				comm_point_listen_for_rw(c, 1, 0);
1309 				return 1; /* wait for read condition */
1310 			} else if(want == SSL_ERROR_WANT_WRITE) {
1311 				ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
1312 				return 1; /* write more later */
1313 			} else if(want == SSL_ERROR_SYSCALL) {
1314 #ifdef EPIPE
1315 				if(errno == EPIPE && verbosity < 2)
1316 					return 0; /* silence 'broken pipe' */
1317 #endif
1318 				if(errno != 0)
1319 					log_err("SSL_write syscall: %s",
1320 						strerror(errno));
1321 				return 0;
1322 			}
1323 			log_crypto_err("could not SSL_write");
1324 			return 0;
1325 		}
1326 		c->tcp_byte_count += r;
1327 		if(c->tcp_byte_count < sizeof(uint16_t))
1328 			return 1;
1329 		sldns_buffer_set_position(c->buffer, c->tcp_byte_count -
1330 			sizeof(uint16_t));
1331 		if(sldns_buffer_remaining(c->buffer) == 0) {
1332 			tcp_callback_writer(c);
1333 			return 1;
1334 		}
1335 	}
1336 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
1337 	ERR_clear_error();
1338 	r = SSL_write(c->ssl, (void*)sldns_buffer_current(c->buffer),
1339 		(int)sldns_buffer_remaining(c->buffer));
1340 	if(r <= 0) {
1341 		int want = SSL_get_error(c->ssl, r);
1342 		if(want == SSL_ERROR_ZERO_RETURN) {
1343 			return 0; /* closed */
1344 		} else if(want == SSL_ERROR_WANT_READ) {
1345 			c->ssl_shake_state = comm_ssl_shake_hs_read;
1346 			comm_point_listen_for_rw(c, 1, 0);
1347 			return 1; /* wait for read condition */
1348 		} else if(want == SSL_ERROR_WANT_WRITE) {
1349 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
1350 			return 1; /* write more later */
1351 		} else if(want == SSL_ERROR_SYSCALL) {
1352 #ifdef EPIPE
1353 			if(errno == EPIPE && verbosity < 2)
1354 				return 0; /* silence 'broken pipe' */
1355 #endif
1356 			if(errno != 0)
1357 				log_err("SSL_write syscall: %s",
1358 					strerror(errno));
1359 			return 0;
1360 		}
1361 		log_crypto_err("could not SSL_write");
1362 		return 0;
1363 	}
1364 	sldns_buffer_skip(c->buffer, (ssize_t)r);
1365 
1366 	if(sldns_buffer_remaining(c->buffer) == 0) {
1367 		tcp_callback_writer(c);
1368 	}
1369 	return 1;
1370 #else
1371 	(void)c;
1372 	return 0;
1373 #endif /* HAVE_SSL */
1374 }
1375 
1376 /** handle ssl tcp connection with dns contents */
1377 static int
1378 ssl_handle_it(struct comm_point* c)
1379 {
1380 	if(c->tcp_is_reading)
1381 		return ssl_handle_read(c);
1382 	return ssl_handle_write(c);
1383 }
1384 
1385 /** Handle tcp reading callback.
1386  * @param fd: file descriptor of socket.
1387  * @param c: comm point to read from into buffer.
1388  * @param short_ok: if true, very short packets are OK (for comm_local).
1389  * @return: 0 on error
1390  */
1391 static int
1392 comm_point_tcp_handle_read(int fd, struct comm_point* c, int short_ok)
1393 {
1394 	ssize_t r;
1395 	log_assert(c->type == comm_tcp || c->type == comm_local);
1396 	if(c->ssl)
1397 		return ssl_handle_it(c);
1398 	if(!c->tcp_is_reading)
1399 		return 0;
1400 
1401 	log_assert(fd != -1);
1402 	if(c->tcp_byte_count < sizeof(uint16_t)) {
1403 		/* read length bytes */
1404 		r = recv(fd,(void*)sldns_buffer_at(c->buffer,c->tcp_byte_count),
1405 			sizeof(uint16_t)-c->tcp_byte_count, 0);
1406 		if(r == 0) {
1407 			if(c->tcp_req_info)
1408 				return tcp_req_info_handle_read_close(c->tcp_req_info);
1409 			return 0;
1410 		} else if(r == -1) {
1411 #ifndef USE_WINSOCK
1412 			if(errno == EINTR || errno == EAGAIN)
1413 				return 1;
1414 #ifdef ECONNRESET
1415 			if(errno == ECONNRESET && verbosity < 2)
1416 				return 0; /* silence reset by peer */
1417 #endif
1418 			log_err_addr("read (in tcp s)", strerror(errno),
1419 				&c->repinfo.addr, c->repinfo.addrlen);
1420 #else /* USE_WINSOCK */
1421 			if(WSAGetLastError() == WSAECONNRESET)
1422 				return 0;
1423 			if(WSAGetLastError() == WSAEINPROGRESS)
1424 				return 1;
1425 			if(WSAGetLastError() == WSAEWOULDBLOCK) {
1426 				ub_winsock_tcp_wouldblock(c->ev->ev,
1427 					UB_EV_READ);
1428 				return 1;
1429 			}
1430 			log_err_addr("read (in tcp s)",
1431 				wsa_strerror(WSAGetLastError()),
1432 				&c->repinfo.addr, c->repinfo.addrlen);
1433 #endif
1434 			return 0;
1435 		}
1436 		c->tcp_byte_count += r;
1437 		if(c->tcp_byte_count != sizeof(uint16_t))
1438 			return 1;
1439 		if(sldns_buffer_read_u16_at(c->buffer, 0) >
1440 			sldns_buffer_capacity(c->buffer)) {
1441 			verbose(VERB_QUERY, "tcp: dropped larger than buffer");
1442 			return 0;
1443 		}
1444 		sldns_buffer_set_limit(c->buffer,
1445 			sldns_buffer_read_u16_at(c->buffer, 0));
1446 		if(!short_ok &&
1447 			sldns_buffer_limit(c->buffer) < LDNS_HEADER_SIZE) {
1448 			verbose(VERB_QUERY, "tcp: dropped bogus too short.");
1449 			return 0;
1450 		}
1451 		verbose(VERB_ALGO, "Reading tcp query of length %d",
1452 			(int)sldns_buffer_limit(c->buffer));
1453 	}
1454 
1455 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
1456 	r = recv(fd, (void*)sldns_buffer_current(c->buffer),
1457 		sldns_buffer_remaining(c->buffer), 0);
1458 	if(r == 0) {
1459 		if(c->tcp_req_info)
1460 			return tcp_req_info_handle_read_close(c->tcp_req_info);
1461 		return 0;
1462 	} else if(r == -1) {
1463 #ifndef USE_WINSOCK
1464 		if(errno == EINTR || errno == EAGAIN)
1465 			return 1;
1466 		log_err_addr("read (in tcp r)", strerror(errno),
1467 			&c->repinfo.addr, c->repinfo.addrlen);
1468 #else /* USE_WINSOCK */
1469 		if(WSAGetLastError() == WSAECONNRESET)
1470 			return 0;
1471 		if(WSAGetLastError() == WSAEINPROGRESS)
1472 			return 1;
1473 		if(WSAGetLastError() == WSAEWOULDBLOCK) {
1474 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
1475 			return 1;
1476 		}
1477 		log_err_addr("read (in tcp r)",
1478 			wsa_strerror(WSAGetLastError()),
1479 			&c->repinfo.addr, c->repinfo.addrlen);
1480 #endif
1481 		return 0;
1482 	}
1483 	sldns_buffer_skip(c->buffer, r);
1484 	if(sldns_buffer_remaining(c->buffer) <= 0) {
1485 		tcp_callback_reader(c);
1486 	}
1487 	return 1;
1488 }
1489 
1490 /**
1491  * Handle tcp writing callback.
1492  * @param fd: file descriptor of socket.
1493  * @param c: comm point to write buffer out of.
1494  * @return: 0 on error
1495  */
1496 static int
1497 comm_point_tcp_handle_write(int fd, struct comm_point* c)
1498 {
1499 	ssize_t r;
1500 	struct sldns_buffer *buffer;
1501 	log_assert(c->type == comm_tcp);
1502 #ifdef USE_DNSCRYPT
1503 	buffer = c->dnscrypt_buffer;
1504 #else
1505 	buffer = c->buffer;
1506 #endif
1507 	if(c->tcp_is_reading && !c->ssl)
1508 		return 0;
1509 	log_assert(fd != -1);
1510 	if(c->tcp_byte_count == 0 && c->tcp_check_nb_connect) {
1511 		/* check for pending error from nonblocking connect */
1512 		/* from Stevens, unix network programming, vol1, 3rd ed, p450*/
1513 		int error = 0;
1514 		socklen_t len = (socklen_t)sizeof(error);
1515 		if(getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&error,
1516 			&len) < 0){
1517 #ifndef USE_WINSOCK
1518 			error = errno; /* on solaris errno is error */
1519 #else /* USE_WINSOCK */
1520 			error = WSAGetLastError();
1521 #endif
1522 		}
1523 #ifndef USE_WINSOCK
1524 #if defined(EINPROGRESS) && defined(EWOULDBLOCK)
1525 		if(error == EINPROGRESS || error == EWOULDBLOCK)
1526 			return 1; /* try again later */
1527 		else
1528 #endif
1529 		if(error != 0 && verbosity < 2)
1530 			return 0; /* silence lots of chatter in the logs */
1531                 else if(error != 0) {
1532 			log_err_addr("tcp connect", strerror(error),
1533 				&c->repinfo.addr, c->repinfo.addrlen);
1534 #else /* USE_WINSOCK */
1535 		/* examine error */
1536 		if(error == WSAEINPROGRESS)
1537 			return 1;
1538 		else if(error == WSAEWOULDBLOCK) {
1539 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
1540 			return 1;
1541 		} else if(error != 0 && verbosity < 2)
1542 			return 0;
1543 		else if(error != 0) {
1544 			log_err_addr("tcp connect", wsa_strerror(error),
1545 				&c->repinfo.addr, c->repinfo.addrlen);
1546 #endif /* USE_WINSOCK */
1547 			return 0;
1548 		}
1549 	}
1550 	if(c->ssl)
1551 		return ssl_handle_it(c);
1552 
1553 #ifdef USE_MSG_FASTOPEN
1554 	/* Only try this on first use of a connection that uses tfo,
1555 	   otherwise fall through to normal write */
1556 	/* Also, TFO support on WINDOWS not implemented at the moment */
1557 	if(c->tcp_do_fastopen == 1) {
1558 		/* this form of sendmsg() does both a connect() and send() so need to
1559 		   look for various flavours of error*/
1560 		uint16_t len = htons(sldns_buffer_limit(buffer));
1561 		struct msghdr msg;
1562 		struct iovec iov[2];
1563 		c->tcp_do_fastopen = 0;
1564 		memset(&msg, 0, sizeof(msg));
1565 		iov[0].iov_base = (uint8_t*)&len + c->tcp_byte_count;
1566 		iov[0].iov_len = sizeof(uint16_t) - c->tcp_byte_count;
1567 		iov[1].iov_base = sldns_buffer_begin(buffer);
1568 		iov[1].iov_len = sldns_buffer_limit(buffer);
1569 		log_assert(iov[0].iov_len > 0);
1570 		msg.msg_name = &c->repinfo.addr;
1571 		msg.msg_namelen = c->repinfo.addrlen;
1572 		msg.msg_iov = iov;
1573 		msg.msg_iovlen = 2;
1574 		r = sendmsg(fd, &msg, MSG_FASTOPEN);
1575 		if (r == -1) {
1576 #if defined(EINPROGRESS) && defined(EWOULDBLOCK)
1577 			/* Handshake is underway, maybe because no TFO cookie available.
1578 			   Come back to write the message*/
1579 			if(errno == EINPROGRESS || errno == EWOULDBLOCK)
1580 				return 1;
1581 #endif
1582 			if(errno == EINTR || errno == EAGAIN)
1583 				return 1;
1584 			/* Not handling EISCONN here as shouldn't ever hit that case.*/
1585 			if(errno != EPIPE && errno != 0 && verbosity < 2)
1586 				return 0; /* silence lots of chatter in the logs */
1587 			if(errno != EPIPE && errno != 0) {
1588 				log_err_addr("tcp sendmsg", strerror(errno),
1589 					&c->repinfo.addr, c->repinfo.addrlen);
1590 				return 0;
1591 			}
1592 			/* fallthrough to nonFASTOPEN
1593 			 * (MSG_FASTOPEN on Linux 3 produces EPIPE)
1594 			 * we need to perform connect() */
1595 			if(connect(fd, (struct sockaddr *)&c->repinfo.addr, c->repinfo.addrlen) == -1) {
1596 #ifdef EINPROGRESS
1597 				if(errno == EINPROGRESS)
1598 					return 1; /* wait until connect done*/
1599 #endif
1600 #ifdef USE_WINSOCK
1601 				if(WSAGetLastError() == WSAEINPROGRESS ||
1602 					WSAGetLastError() == WSAEWOULDBLOCK)
1603 					return 1; /* wait until connect done*/
1604 #endif
1605 				if(tcp_connect_errno_needs_log(
1606 					(struct sockaddr *)&c->repinfo.addr, c->repinfo.addrlen)) {
1607 					log_err_addr("outgoing tcp: connect after EPIPE for fastopen",
1608 						strerror(errno), &c->repinfo.addr, c->repinfo.addrlen);
1609 				}
1610 				return 0;
1611 			}
1612 
1613 		} else {
1614 			c->tcp_byte_count += r;
1615 			if(c->tcp_byte_count < sizeof(uint16_t))
1616 				return 1;
1617 			sldns_buffer_set_position(buffer, c->tcp_byte_count -
1618 				sizeof(uint16_t));
1619 			if(sldns_buffer_remaining(buffer) == 0) {
1620 				tcp_callback_writer(c);
1621 				return 1;
1622 			}
1623 		}
1624 	}
1625 #endif /* USE_MSG_FASTOPEN */
1626 
1627 	if(c->tcp_byte_count < sizeof(uint16_t)) {
1628 		uint16_t len = htons(sldns_buffer_limit(buffer));
1629 #ifdef HAVE_WRITEV
1630 		struct iovec iov[2];
1631 		iov[0].iov_base = (uint8_t*)&len + c->tcp_byte_count;
1632 		iov[0].iov_len = sizeof(uint16_t) - c->tcp_byte_count;
1633 		iov[1].iov_base = sldns_buffer_begin(buffer);
1634 		iov[1].iov_len = sldns_buffer_limit(buffer);
1635 		log_assert(iov[0].iov_len > 0);
1636 		r = writev(fd, iov, 2);
1637 #else /* HAVE_WRITEV */
1638 		r = send(fd, (void*)(((uint8_t*)&len)+c->tcp_byte_count),
1639 			sizeof(uint16_t)-c->tcp_byte_count, 0);
1640 #endif /* HAVE_WRITEV */
1641 		if(r == -1) {
1642 #ifndef USE_WINSOCK
1643 #  ifdef EPIPE
1644                 	if(errno == EPIPE && verbosity < 2)
1645                         	return 0; /* silence 'broken pipe' */
1646   #endif
1647 			if(errno == EINTR || errno == EAGAIN)
1648 				return 1;
1649 #ifdef ECONNRESET
1650 			if(errno == ECONNRESET && verbosity < 2)
1651 				return 0; /* silence reset by peer */
1652 #endif
1653 #  ifdef HAVE_WRITEV
1654 			log_err_addr("tcp writev", strerror(errno),
1655 				&c->repinfo.addr, c->repinfo.addrlen);
1656 #  else /* HAVE_WRITEV */
1657 			log_err_addr("tcp send s", strerror(errno),
1658 				&c->repinfo.addr, c->repinfo.addrlen);
1659 #  endif /* HAVE_WRITEV */
1660 #else
1661 			if(WSAGetLastError() == WSAENOTCONN)
1662 				return 1;
1663 			if(WSAGetLastError() == WSAEINPROGRESS)
1664 				return 1;
1665 			if(WSAGetLastError() == WSAEWOULDBLOCK) {
1666 				ub_winsock_tcp_wouldblock(c->ev->ev,
1667 					UB_EV_WRITE);
1668 				return 1;
1669 			}
1670 			if(WSAGetLastError() == WSAECONNRESET && verbosity < 2)
1671 				return 0; /* silence reset by peer */
1672 			log_err_addr("tcp send s",
1673 				wsa_strerror(WSAGetLastError()),
1674 				&c->repinfo.addr, c->repinfo.addrlen);
1675 #endif
1676 			return 0;
1677 		}
1678 		c->tcp_byte_count += r;
1679 		if(c->tcp_byte_count < sizeof(uint16_t))
1680 			return 1;
1681 		sldns_buffer_set_position(buffer, c->tcp_byte_count -
1682 			sizeof(uint16_t));
1683 		if(sldns_buffer_remaining(buffer) == 0) {
1684 			tcp_callback_writer(c);
1685 			return 1;
1686 		}
1687 	}
1688 	log_assert(sldns_buffer_remaining(buffer) > 0);
1689 	r = send(fd, (void*)sldns_buffer_current(buffer),
1690 		sldns_buffer_remaining(buffer), 0);
1691 	if(r == -1) {
1692 #ifndef USE_WINSOCK
1693 		if(errno == EINTR || errno == EAGAIN)
1694 			return 1;
1695 #ifdef ECONNRESET
1696 		if(errno == ECONNRESET && verbosity < 2)
1697 			return 0; /* silence reset by peer */
1698 #endif
1699 		log_err_addr("tcp send r", strerror(errno),
1700 			&c->repinfo.addr, c->repinfo.addrlen);
1701 #else
1702 		if(WSAGetLastError() == WSAEINPROGRESS)
1703 			return 1;
1704 		if(WSAGetLastError() == WSAEWOULDBLOCK) {
1705 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
1706 			return 1;
1707 		}
1708 		if(WSAGetLastError() == WSAECONNRESET && verbosity < 2)
1709 			return 0; /* silence reset by peer */
1710 		log_err_addr("tcp send r", wsa_strerror(WSAGetLastError()),
1711 			&c->repinfo.addr, c->repinfo.addrlen);
1712 #endif
1713 		return 0;
1714 	}
1715 	sldns_buffer_skip(buffer, r);
1716 
1717 	if(sldns_buffer_remaining(buffer) == 0) {
1718 		tcp_callback_writer(c);
1719 	}
1720 
1721 	return 1;
1722 }
1723 
1724 /** read again to drain buffers when there could be more to read */
1725 static void
1726 tcp_req_info_read_again(int fd, struct comm_point* c)
1727 {
1728 	while(c->tcp_req_info->read_again) {
1729 		int r;
1730 		c->tcp_req_info->read_again = 0;
1731 		if(c->tcp_is_reading)
1732 			r = comm_point_tcp_handle_read(fd, c, 0);
1733 		else 	r = comm_point_tcp_handle_write(fd, c);
1734 		if(!r) {
1735 			reclaim_tcp_handler(c);
1736 			if(!c->tcp_do_close) {
1737 				fptr_ok(fptr_whitelist_comm_point(
1738 					c->callback));
1739 				(void)(*c->callback)(c, c->cb_arg,
1740 					NETEVENT_CLOSED, NULL);
1741 			}
1742 			return;
1743 		}
1744 	}
1745 }
1746 
1747 void
1748 comm_point_tcp_handle_callback(int fd, short event, void* arg)
1749 {
1750 	struct comm_point* c = (struct comm_point*)arg;
1751 	log_assert(c->type == comm_tcp);
1752 	ub_comm_base_now(c->ev->base);
1753 
1754 #ifdef USE_DNSCRYPT
1755 	/* Initialize if this is a dnscrypt socket */
1756 	if(c->tcp_parent) {
1757 		c->dnscrypt = c->tcp_parent->dnscrypt;
1758 	}
1759 	if(c->dnscrypt && c->dnscrypt_buffer == c->buffer) {
1760 		c->dnscrypt_buffer = sldns_buffer_new(sldns_buffer_capacity(c->buffer));
1761 		if(!c->dnscrypt_buffer) {
1762 			log_err("Could not allocate dnscrypt buffer");
1763 			reclaim_tcp_handler(c);
1764 			if(!c->tcp_do_close) {
1765 				fptr_ok(fptr_whitelist_comm_point(
1766 					c->callback));
1767 				(void)(*c->callback)(c, c->cb_arg,
1768 					NETEVENT_CLOSED, NULL);
1769 			}
1770 			return;
1771 		}
1772 	}
1773 #endif
1774 
1775 	if(event&UB_EV_TIMEOUT) {
1776 		verbose(VERB_QUERY, "tcp took too long, dropped");
1777 		reclaim_tcp_handler(c);
1778 		if(!c->tcp_do_close) {
1779 			fptr_ok(fptr_whitelist_comm_point(c->callback));
1780 			(void)(*c->callback)(c, c->cb_arg,
1781 				NETEVENT_TIMEOUT, NULL);
1782 		}
1783 		return;
1784 	}
1785 	if(event&UB_EV_READ) {
1786 		int has_tcpq = (c->tcp_req_info != NULL);
1787 		if(!comm_point_tcp_handle_read(fd, c, 0)) {
1788 			reclaim_tcp_handler(c);
1789 			if(!c->tcp_do_close) {
1790 				fptr_ok(fptr_whitelist_comm_point(
1791 					c->callback));
1792 				(void)(*c->callback)(c, c->cb_arg,
1793 					NETEVENT_CLOSED, NULL);
1794 			}
1795 		}
1796 		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
1797 			tcp_req_info_read_again(fd, c);
1798 		return;
1799 	}
1800 	if(event&UB_EV_WRITE) {
1801 		int has_tcpq = (c->tcp_req_info != NULL);
1802 		if(!comm_point_tcp_handle_write(fd, c)) {
1803 			reclaim_tcp_handler(c);
1804 			if(!c->tcp_do_close) {
1805 				fptr_ok(fptr_whitelist_comm_point(
1806 					c->callback));
1807 				(void)(*c->callback)(c, c->cb_arg,
1808 					NETEVENT_CLOSED, NULL);
1809 			}
1810 		}
1811 		if(has_tcpq && c->tcp_req_info && c->tcp_req_info->read_again)
1812 			tcp_req_info_read_again(fd, c);
1813 		return;
1814 	}
1815 	log_err("Ignored event %d for tcphdl.", event);
1816 }
1817 
1818 /** Make http handler free for next assignment */
1819 static void
1820 reclaim_http_handler(struct comm_point* c)
1821 {
1822 	log_assert(c->type == comm_http);
1823 	if(c->ssl) {
1824 #ifdef HAVE_SSL
1825 		SSL_shutdown(c->ssl);
1826 		SSL_free(c->ssl);
1827 		c->ssl = NULL;
1828 #endif
1829 	}
1830 	comm_point_close(c);
1831 	if(c->tcp_parent) {
1832 		c->tcp_parent->cur_tcp_count--;
1833 		c->tcp_free = c->tcp_parent->tcp_free;
1834 		c->tcp_parent->tcp_free = c;
1835 		if(!c->tcp_free) {
1836 			/* re-enable listening on accept socket */
1837 			comm_point_start_listening(c->tcp_parent, -1, -1);
1838 		}
1839 	}
1840 }
1841 
1842 /** read more data for http (with ssl) */
1843 static int
1844 ssl_http_read_more(struct comm_point* c)
1845 {
1846 #ifdef HAVE_SSL
1847 	int r;
1848 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
1849 	ERR_clear_error();
1850 	r = SSL_read(c->ssl, (void*)sldns_buffer_current(c->buffer),
1851 		(int)sldns_buffer_remaining(c->buffer));
1852 	if(r <= 0) {
1853 		int want = SSL_get_error(c->ssl, r);
1854 		if(want == SSL_ERROR_ZERO_RETURN) {
1855 			return 0; /* shutdown, closed */
1856 		} else if(want == SSL_ERROR_WANT_READ) {
1857 			return 1; /* read more later */
1858 		} else if(want == SSL_ERROR_WANT_WRITE) {
1859 			c->ssl_shake_state = comm_ssl_shake_hs_write;
1860 			comm_point_listen_for_rw(c, 0, 1);
1861 			return 1;
1862 		} else if(want == SSL_ERROR_SYSCALL) {
1863 #ifdef ECONNRESET
1864 			if(errno == ECONNRESET && verbosity < 2)
1865 				return 0; /* silence reset by peer */
1866 #endif
1867 			if(errno != 0)
1868 				log_err("SSL_read syscall: %s",
1869 					strerror(errno));
1870 			return 0;
1871 		}
1872 		log_crypto_err("could not SSL_read");
1873 		return 0;
1874 	}
1875 	sldns_buffer_skip(c->buffer, (ssize_t)r);
1876 	return 1;
1877 #else
1878 	(void)c;
1879 	return 0;
1880 #endif /* HAVE_SSL */
1881 }
1882 
1883 /** read more data for http */
1884 static int
1885 http_read_more(int fd, struct comm_point* c)
1886 {
1887 	ssize_t r;
1888 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
1889 	r = recv(fd, (void*)sldns_buffer_current(c->buffer),
1890 		sldns_buffer_remaining(c->buffer), 0);
1891 	if(r == 0) {
1892 		return 0;
1893 	} else if(r == -1) {
1894 #ifndef USE_WINSOCK
1895 		if(errno == EINTR || errno == EAGAIN)
1896 			return 1;
1897 		log_err_addr("read (in http r)", strerror(errno),
1898 			&c->repinfo.addr, c->repinfo.addrlen);
1899 #else /* USE_WINSOCK */
1900 		if(WSAGetLastError() == WSAECONNRESET)
1901 			return 0;
1902 		if(WSAGetLastError() == WSAEINPROGRESS)
1903 			return 1;
1904 		if(WSAGetLastError() == WSAEWOULDBLOCK) {
1905 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
1906 			return 1;
1907 		}
1908 		log_err_addr("read (in http r)",
1909 			wsa_strerror(WSAGetLastError()),
1910 			&c->repinfo.addr, c->repinfo.addrlen);
1911 #endif
1912 		return 0;
1913 	}
1914 	sldns_buffer_skip(c->buffer, r);
1915 	return 1;
1916 }
1917 
1918 /** return true if http header has been read (one line complete) */
1919 static int
1920 http_header_done(sldns_buffer* buf)
1921 {
1922 	size_t i;
1923 	for(i=sldns_buffer_position(buf); i<sldns_buffer_limit(buf); i++) {
1924 		/* there was a \r before the \n, but we ignore that */
1925 		if((char)sldns_buffer_read_u8_at(buf, i) == '\n')
1926 			return 1;
1927 	}
1928 	return 0;
1929 }
1930 
1931 /** return character string into buffer for header line, moves buffer
1932  * past that line and puts zero terminator into linefeed-newline */
1933 static char*
1934 http_header_line(sldns_buffer* buf)
1935 {
1936 	char* result = (char*)sldns_buffer_current(buf);
1937 	size_t i;
1938 	for(i=sldns_buffer_position(buf); i<sldns_buffer_limit(buf); i++) {
1939 		/* terminate the string on the \r */
1940 		if((char)sldns_buffer_read_u8_at(buf, i) == '\r')
1941 			sldns_buffer_write_u8_at(buf, i, 0);
1942 		/* terminate on the \n and skip past the it and done */
1943 		if((char)sldns_buffer_read_u8_at(buf, i) == '\n') {
1944 			sldns_buffer_write_u8_at(buf, i, 0);
1945 			sldns_buffer_set_position(buf, i+1);
1946 			return result;
1947 		}
1948 	}
1949 	return NULL;
1950 }
1951 
1952 /** move unread buffer to start and clear rest for putting the rest into it */
1953 static void
1954 http_moveover_buffer(sldns_buffer* buf)
1955 {
1956 	size_t pos = sldns_buffer_position(buf);
1957 	size_t len = sldns_buffer_remaining(buf);
1958 	sldns_buffer_clear(buf);
1959 	memmove(sldns_buffer_begin(buf), sldns_buffer_at(buf, pos), len);
1960 	sldns_buffer_set_position(buf, len);
1961 }
1962 
1963 /** a http header is complete, process it */
1964 static int
1965 http_process_initial_header(struct comm_point* c)
1966 {
1967 	char* line = http_header_line(c->buffer);
1968 	if(!line) return 1;
1969 	verbose(VERB_ALGO, "http header: %s", line);
1970 	if(strncasecmp(line, "HTTP/1.1 ", 9) == 0) {
1971 		/* check returncode */
1972 		if(line[9] != '2') {
1973 			verbose(VERB_ALGO, "http bad status %s", line+9);
1974 			return 0;
1975 		}
1976 	} else if(strncasecmp(line, "Content-Length: ", 16) == 0) {
1977 		if(!c->http_is_chunked)
1978 			c->tcp_byte_count = (size_t)atoi(line+16);
1979 	} else if(strncasecmp(line, "Transfer-Encoding: chunked", 19+7) == 0) {
1980 		c->tcp_byte_count = 0;
1981 		c->http_is_chunked = 1;
1982 	} else if(line[0] == 0) {
1983 		/* end of initial headers */
1984 		c->http_in_headers = 0;
1985 		if(c->http_is_chunked)
1986 			c->http_in_chunk_headers = 1;
1987 		/* remove header text from front of buffer
1988 		 * the buffer is going to be used to return the data segment
1989 		 * itself and we don't want the header to get returned
1990 		 * prepended with it */
1991 		http_moveover_buffer(c->buffer);
1992 		sldns_buffer_flip(c->buffer);
1993 		return 1;
1994 	}
1995 	/* ignore other headers */
1996 	return 1;
1997 }
1998 
1999 /** a chunk header is complete, process it, return 0=fail, 1=continue next
2000  * header line, 2=done with chunked transfer*/
2001 static int
2002 http_process_chunk_header(struct comm_point* c)
2003 {
2004 	char* line = http_header_line(c->buffer);
2005 	if(!line) return 1;
2006 	if(c->http_in_chunk_headers == 3) {
2007 		verbose(VERB_ALGO, "http chunk trailer: %s", line);
2008 		/* are we done ? */
2009 		if(line[0] == 0 && c->tcp_byte_count == 0) {
2010 			/* callback of http reader when NETEVENT_DONE,
2011 			 * end of data, with no data in buffer */
2012 			sldns_buffer_set_position(c->buffer, 0);
2013 			sldns_buffer_set_limit(c->buffer, 0);
2014 			fptr_ok(fptr_whitelist_comm_point(c->callback));
2015 			(void)(*c->callback)(c, c->cb_arg, NETEVENT_DONE, NULL);
2016 			/* return that we are done */
2017 			return 2;
2018 		}
2019 		if(line[0] == 0) {
2020 			/* continue with header of the next chunk */
2021 			c->http_in_chunk_headers = 1;
2022 			/* remove header text from front of buffer */
2023 			http_moveover_buffer(c->buffer);
2024 			sldns_buffer_flip(c->buffer);
2025 			return 1;
2026 		}
2027 		/* ignore further trail headers */
2028 		return 1;
2029 	}
2030 	verbose(VERB_ALGO, "http chunk header: %s", line);
2031 	if(c->http_in_chunk_headers == 1) {
2032 		/* read chunked start line */
2033 		char* end = NULL;
2034 		c->tcp_byte_count = (size_t)strtol(line, &end, 16);
2035 		if(end == line)
2036 			return 0;
2037 		c->http_in_chunk_headers = 0;
2038 		/* remove header text from front of buffer */
2039 		http_moveover_buffer(c->buffer);
2040 		sldns_buffer_flip(c->buffer);
2041 		if(c->tcp_byte_count == 0) {
2042 			/* done with chunks, process chunk_trailer lines */
2043 			c->http_in_chunk_headers = 3;
2044 		}
2045 		return 1;
2046 	}
2047 	/* ignore other headers */
2048 	return 1;
2049 }
2050 
2051 /** handle nonchunked data segment */
2052 static int
2053 http_nonchunk_segment(struct comm_point* c)
2054 {
2055 	/* c->buffer at position..limit has new data we read in.
2056 	 * the buffer itself is full of nonchunked data.
2057 	 * we are looking to read tcp_byte_count more data
2058 	 * and then the transfer is done. */
2059 	size_t remainbufferlen;
2060 	size_t got_now = sldns_buffer_limit(c->buffer) - c->http_stored;
2061 	if(c->tcp_byte_count <= got_now) {
2062 		/* done, this is the last data fragment */
2063 		c->http_stored = 0;
2064 		sldns_buffer_set_position(c->buffer, 0);
2065 		fptr_ok(fptr_whitelist_comm_point(c->callback));
2066 		(void)(*c->callback)(c, c->cb_arg, NETEVENT_DONE, NULL);
2067 		return 1;
2068 	}
2069 	c->tcp_byte_count -= got_now;
2070 	/* if we have the buffer space,
2071 	 * read more data collected into the buffer */
2072 	remainbufferlen = sldns_buffer_capacity(c->buffer) -
2073 		sldns_buffer_limit(c->buffer);
2074 	if(remainbufferlen >= c->tcp_byte_count ||
2075 		remainbufferlen >= 2048) {
2076 		size_t total = sldns_buffer_limit(c->buffer);
2077 		sldns_buffer_clear(c->buffer);
2078 		sldns_buffer_set_position(c->buffer, total);
2079 		c->http_stored = total;
2080 		/* return and wait to read more */
2081 		return 1;
2082 	}
2083 	/* call callback with this data amount, then
2084 	 * wait for more */
2085 	c->http_stored = 0;
2086 	sldns_buffer_set_position(c->buffer, 0);
2087 	fptr_ok(fptr_whitelist_comm_point(c->callback));
2088 	(void)(*c->callback)(c, c->cb_arg, NETEVENT_NOERROR, NULL);
2089 	/* c->callback has to buffer_clear(c->buffer). */
2090 	/* return and wait to read more */
2091 	return 1;
2092 }
2093 
2094 /** handle nonchunked data segment, return 0=fail, 1=wait, 2=process more */
2095 static int
2096 http_chunked_segment(struct comm_point* c)
2097 {
2098 	/* the c->buffer has from position..limit new data we read. */
2099 	/* the current chunk has length tcp_byte_count.
2100 	 * once we read that read more chunk headers.
2101 	 */
2102 	size_t remainbufferlen;
2103 	size_t got_now = sldns_buffer_limit(c->buffer) - c->http_stored;
2104 	if(c->tcp_byte_count <= got_now) {
2105 		/* the chunk has completed (with perhaps some extra data
2106 		 * from next chunk header and next chunk) */
2107 		/* save too much info into temp buffer */
2108 		size_t fraglen;
2109 		struct comm_reply repinfo;
2110 		c->http_stored = 0;
2111 		sldns_buffer_skip(c->buffer, (ssize_t)c->tcp_byte_count);
2112 		sldns_buffer_clear(c->http_temp);
2113 		sldns_buffer_write(c->http_temp,
2114 			sldns_buffer_current(c->buffer),
2115 			sldns_buffer_remaining(c->buffer));
2116 		sldns_buffer_flip(c->http_temp);
2117 
2118 		/* callback with this fragment */
2119 		fraglen = sldns_buffer_position(c->buffer);
2120 		sldns_buffer_set_position(c->buffer, 0);
2121 		sldns_buffer_set_limit(c->buffer, fraglen);
2122 		repinfo = c->repinfo;
2123 		fptr_ok(fptr_whitelist_comm_point(c->callback));
2124 		(void)(*c->callback)(c, c->cb_arg, NETEVENT_NOERROR, &repinfo);
2125 		/* c->callback has to buffer_clear(). */
2126 
2127 		/* is commpoint deleted? */
2128 		if(!repinfo.c) {
2129 			return 1;
2130 		}
2131 		/* copy waiting info */
2132 		sldns_buffer_clear(c->buffer);
2133 		sldns_buffer_write(c->buffer,
2134 			sldns_buffer_begin(c->http_temp),
2135 			sldns_buffer_remaining(c->http_temp));
2136 		sldns_buffer_flip(c->buffer);
2137 		/* process end of chunk trailer header lines, until
2138 		 * an empty line */
2139 		c->http_in_chunk_headers = 3;
2140 		/* process more data in buffer (if any) */
2141 		return 2;
2142 	}
2143 	c->tcp_byte_count -= got_now;
2144 
2145 	/* if we have the buffer space,
2146 	 * read more data collected into the buffer */
2147 	remainbufferlen = sldns_buffer_capacity(c->buffer) -
2148 		sldns_buffer_limit(c->buffer);
2149 	if(remainbufferlen >= c->tcp_byte_count ||
2150 		remainbufferlen >= 2048) {
2151 		size_t total = sldns_buffer_limit(c->buffer);
2152 		sldns_buffer_clear(c->buffer);
2153 		sldns_buffer_set_position(c->buffer, total);
2154 		c->http_stored = total;
2155 		/* return and wait to read more */
2156 		return 1;
2157 	}
2158 
2159 	/* callback of http reader for a new part of the data */
2160 	c->http_stored = 0;
2161 	sldns_buffer_set_position(c->buffer, 0);
2162 	fptr_ok(fptr_whitelist_comm_point(c->callback));
2163 	(void)(*c->callback)(c, c->cb_arg, NETEVENT_NOERROR, NULL);
2164 	/* c->callback has to buffer_clear(c->buffer). */
2165 	/* return and wait to read more */
2166 	return 1;
2167 }
2168 
2169 /**
2170  * Handle http reading callback.
2171  * @param fd: file descriptor of socket.
2172  * @param c: comm point to read from into buffer.
2173  * @return: 0 on error
2174  */
2175 static int
2176 comm_point_http_handle_read(int fd, struct comm_point* c)
2177 {
2178 	log_assert(c->type == comm_http);
2179 	log_assert(fd != -1);
2180 
2181 	/* if we are in ssl handshake, handle SSL handshake */
2182 #ifdef HAVE_SSL
2183 	if(c->ssl && c->ssl_shake_state != comm_ssl_shake_none) {
2184 		if(!ssl_handshake(c))
2185 			return 0;
2186 		if(c->ssl_shake_state != comm_ssl_shake_none)
2187 			return 1;
2188 	}
2189 #endif /* HAVE_SSL */
2190 
2191 	if(!c->tcp_is_reading)
2192 		return 1;
2193 	/* read more data */
2194 	if(c->ssl) {
2195 		if(!ssl_http_read_more(c))
2196 			return 0;
2197 	} else {
2198 		if(!http_read_more(fd, c))
2199 			return 0;
2200 	}
2201 
2202 	sldns_buffer_flip(c->buffer);
2203 	while(sldns_buffer_remaining(c->buffer) > 0) {
2204 		/* if we are reading headers, read more headers */
2205 		if(c->http_in_headers || c->http_in_chunk_headers) {
2206 			/* if header is done, process the header */
2207 			if(!http_header_done(c->buffer)) {
2208 				/* copy remaining data to front of buffer
2209 				 * and set rest for writing into it */
2210 				http_moveover_buffer(c->buffer);
2211 				/* return and wait to read more */
2212 				return 1;
2213 			}
2214 			if(!c->http_in_chunk_headers) {
2215 				/* process initial headers */
2216 				if(!http_process_initial_header(c))
2217 					return 0;
2218 			} else {
2219 				/* process chunk headers */
2220 				int r = http_process_chunk_header(c);
2221 				if(r == 0) return 0;
2222 				if(r == 2) return 1; /* done */
2223 				/* r == 1, continue */
2224 			}
2225 			/* see if we have more to process */
2226 			continue;
2227 		}
2228 
2229 		if(!c->http_is_chunked) {
2230 			/* if we are reading nonchunks, process that*/
2231 			return http_nonchunk_segment(c);
2232 		} else {
2233 			/* if we are reading chunks, read the chunk */
2234 			int r = http_chunked_segment(c);
2235 			if(r == 0) return 0;
2236 			if(r == 1) return 1;
2237 			continue;
2238 		}
2239 	}
2240 	/* broke out of the loop; could not process header instead need
2241 	 * to read more */
2242 	/* moveover any remaining data and read more data */
2243 	http_moveover_buffer(c->buffer);
2244 	/* return and wait to read more */
2245 	return 1;
2246 }
2247 
2248 /** check pending connect for http */
2249 static int
2250 http_check_connect(int fd, struct comm_point* c)
2251 {
2252 	/* check for pending error from nonblocking connect */
2253 	/* from Stevens, unix network programming, vol1, 3rd ed, p450*/
2254 	int error = 0;
2255 	socklen_t len = (socklen_t)sizeof(error);
2256 	if(getsockopt(fd, SOL_SOCKET, SO_ERROR, (void*)&error,
2257 		&len) < 0){
2258 #ifndef USE_WINSOCK
2259 		error = errno; /* on solaris errno is error */
2260 #else /* USE_WINSOCK */
2261 		error = WSAGetLastError();
2262 #endif
2263 	}
2264 #ifndef USE_WINSOCK
2265 #if defined(EINPROGRESS) && defined(EWOULDBLOCK)
2266 	if(error == EINPROGRESS || error == EWOULDBLOCK)
2267 		return 1; /* try again later */
2268 	else
2269 #endif
2270 	if(error != 0 && verbosity < 2)
2271 		return 0; /* silence lots of chatter in the logs */
2272 	else if(error != 0) {
2273 		log_err_addr("http connect", strerror(error),
2274 			&c->repinfo.addr, c->repinfo.addrlen);
2275 #else /* USE_WINSOCK */
2276 	/* examine error */
2277 	if(error == WSAEINPROGRESS)
2278 		return 1;
2279 	else if(error == WSAEWOULDBLOCK) {
2280 		ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
2281 		return 1;
2282 	} else if(error != 0 && verbosity < 2)
2283 		return 0;
2284 	else if(error != 0) {
2285 		log_err_addr("http connect", wsa_strerror(error),
2286 			&c->repinfo.addr, c->repinfo.addrlen);
2287 #endif /* USE_WINSOCK */
2288 		return 0;
2289 	}
2290 	/* keep on processing this socket */
2291 	return 2;
2292 }
2293 
2294 /** write more data for http (with ssl) */
2295 static int
2296 ssl_http_write_more(struct comm_point* c)
2297 {
2298 #ifdef HAVE_SSL
2299 	int r;
2300 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
2301 	ERR_clear_error();
2302 	r = SSL_write(c->ssl, (void*)sldns_buffer_current(c->buffer),
2303 		(int)sldns_buffer_remaining(c->buffer));
2304 	if(r <= 0) {
2305 		int want = SSL_get_error(c->ssl, r);
2306 		if(want == SSL_ERROR_ZERO_RETURN) {
2307 			return 0; /* closed */
2308 		} else if(want == SSL_ERROR_WANT_READ) {
2309 			c->ssl_shake_state = comm_ssl_shake_hs_read;
2310 			comm_point_listen_for_rw(c, 1, 0);
2311 			return 1; /* wait for read condition */
2312 		} else if(want == SSL_ERROR_WANT_WRITE) {
2313 			return 1; /* write more later */
2314 		} else if(want == SSL_ERROR_SYSCALL) {
2315 #ifdef EPIPE
2316 			if(errno == EPIPE && verbosity < 2)
2317 				return 0; /* silence 'broken pipe' */
2318 #endif
2319 			if(errno != 0)
2320 				log_err("SSL_write syscall: %s",
2321 					strerror(errno));
2322 			return 0;
2323 		}
2324 		log_crypto_err("could not SSL_write");
2325 		return 0;
2326 	}
2327 	sldns_buffer_skip(c->buffer, (ssize_t)r);
2328 	return 1;
2329 #else
2330 	(void)c;
2331 	return 0;
2332 #endif /* HAVE_SSL */
2333 }
2334 
2335 /** write more data for http */
2336 static int
2337 http_write_more(int fd, struct comm_point* c)
2338 {
2339 	ssize_t r;
2340 	log_assert(sldns_buffer_remaining(c->buffer) > 0);
2341 	r = send(fd, (void*)sldns_buffer_current(c->buffer),
2342 		sldns_buffer_remaining(c->buffer), 0);
2343 	if(r == -1) {
2344 #ifndef USE_WINSOCK
2345 		if(errno == EINTR || errno == EAGAIN)
2346 			return 1;
2347 		log_err_addr("http send r", strerror(errno),
2348 			&c->repinfo.addr, c->repinfo.addrlen);
2349 #else
2350 		if(WSAGetLastError() == WSAEINPROGRESS)
2351 			return 1;
2352 		if(WSAGetLastError() == WSAEWOULDBLOCK) {
2353 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
2354 			return 1;
2355 		}
2356 		log_err_addr("http send r", wsa_strerror(WSAGetLastError()),
2357 			&c->repinfo.addr, c->repinfo.addrlen);
2358 #endif
2359 		return 0;
2360 	}
2361 	sldns_buffer_skip(c->buffer, r);
2362 	return 1;
2363 }
2364 
2365 /**
2366  * Handle http writing callback.
2367  * @param fd: file descriptor of socket.
2368  * @param c: comm point to write buffer out of.
2369  * @return: 0 on error
2370  */
2371 static int
2372 comm_point_http_handle_write(int fd, struct comm_point* c)
2373 {
2374 	log_assert(c->type == comm_http);
2375 	log_assert(fd != -1);
2376 
2377 	/* check pending connect errors, if that fails, we wait for more,
2378 	 * or we can continue to write contents */
2379 	if(c->tcp_check_nb_connect) {
2380 		int r = http_check_connect(fd, c);
2381 		if(r == 0) return 0;
2382 		if(r == 1) return 1;
2383 		c->tcp_check_nb_connect = 0;
2384 	}
2385 	/* if we are in ssl handshake, handle SSL handshake */
2386 #ifdef HAVE_SSL
2387 	if(c->ssl && c->ssl_shake_state != comm_ssl_shake_none) {
2388 		if(!ssl_handshake(c))
2389 			return 0;
2390 		if(c->ssl_shake_state != comm_ssl_shake_none)
2391 			return 1;
2392 	}
2393 #endif /* HAVE_SSL */
2394 	if(c->tcp_is_reading)
2395 		return 1;
2396 	/* if we are writing, write more */
2397 	if(c->ssl) {
2398 		if(!ssl_http_write_more(c))
2399 			return 0;
2400 	} else {
2401 		if(!http_write_more(fd, c))
2402 			return 0;
2403 	}
2404 
2405 	/* we write a single buffer contents, that can contain
2406 	 * the http request, and then flip to read the results */
2407 	/* see if write is done */
2408 	if(sldns_buffer_remaining(c->buffer) == 0) {
2409 		sldns_buffer_clear(c->buffer);
2410 		if(c->tcp_do_toggle_rw)
2411 			c->tcp_is_reading = 1;
2412 		c->tcp_byte_count = 0;
2413 		/* switch from listening(write) to listening(read) */
2414 		comm_point_stop_listening(c);
2415 		comm_point_start_listening(c, -1, -1);
2416 	}
2417 	return 1;
2418 }
2419 
2420 void
2421 comm_point_http_handle_callback(int fd, short event, void* arg)
2422 {
2423 	struct comm_point* c = (struct comm_point*)arg;
2424 	log_assert(c->type == comm_http);
2425 	ub_comm_base_now(c->ev->base);
2426 
2427 	if(event&UB_EV_TIMEOUT) {
2428 		verbose(VERB_QUERY, "http took too long, dropped");
2429 		reclaim_http_handler(c);
2430 		if(!c->tcp_do_close) {
2431 			fptr_ok(fptr_whitelist_comm_point(c->callback));
2432 			(void)(*c->callback)(c, c->cb_arg,
2433 				NETEVENT_TIMEOUT, NULL);
2434 		}
2435 		return;
2436 	}
2437 	if(event&UB_EV_READ) {
2438 		if(!comm_point_http_handle_read(fd, c)) {
2439 			reclaim_http_handler(c);
2440 			if(!c->tcp_do_close) {
2441 				fptr_ok(fptr_whitelist_comm_point(
2442 					c->callback));
2443 				(void)(*c->callback)(c, c->cb_arg,
2444 					NETEVENT_CLOSED, NULL);
2445 			}
2446 		}
2447 		return;
2448 	}
2449 	if(event&UB_EV_WRITE) {
2450 		if(!comm_point_http_handle_write(fd, c)) {
2451 			reclaim_http_handler(c);
2452 			if(!c->tcp_do_close) {
2453 				fptr_ok(fptr_whitelist_comm_point(
2454 					c->callback));
2455 				(void)(*c->callback)(c, c->cb_arg,
2456 					NETEVENT_CLOSED, NULL);
2457 			}
2458 		}
2459 		return;
2460 	}
2461 	log_err("Ignored event %d for httphdl.", event);
2462 }
2463 
2464 void comm_point_local_handle_callback(int fd, short event, void* arg)
2465 {
2466 	struct comm_point* c = (struct comm_point*)arg;
2467 	log_assert(c->type == comm_local);
2468 	ub_comm_base_now(c->ev->base);
2469 
2470 	if(event&UB_EV_READ) {
2471 		if(!comm_point_tcp_handle_read(fd, c, 1)) {
2472 			fptr_ok(fptr_whitelist_comm_point(c->callback));
2473 			(void)(*c->callback)(c, c->cb_arg, NETEVENT_CLOSED,
2474 				NULL);
2475 		}
2476 		return;
2477 	}
2478 	log_err("Ignored event %d for localhdl.", event);
2479 }
2480 
2481 void comm_point_raw_handle_callback(int ATTR_UNUSED(fd),
2482 	short event, void* arg)
2483 {
2484 	struct comm_point* c = (struct comm_point*)arg;
2485 	int err = NETEVENT_NOERROR;
2486 	log_assert(c->type == comm_raw);
2487 	ub_comm_base_now(c->ev->base);
2488 
2489 	if(event&UB_EV_TIMEOUT)
2490 		err = NETEVENT_TIMEOUT;
2491 	fptr_ok(fptr_whitelist_comm_point_raw(c->callback));
2492 	(void)(*c->callback)(c, c->cb_arg, err, NULL);
2493 }
2494 
2495 struct comm_point*
2496 comm_point_create_udp(struct comm_base *base, int fd, sldns_buffer* buffer,
2497 	comm_point_callback_type* callback, void* callback_arg)
2498 {
2499 	struct comm_point* c = (struct comm_point*)calloc(1,
2500 		sizeof(struct comm_point));
2501 	short evbits;
2502 	if(!c)
2503 		return NULL;
2504 	c->ev = (struct internal_event*)calloc(1,
2505 		sizeof(struct internal_event));
2506 	if(!c->ev) {
2507 		free(c);
2508 		return NULL;
2509 	}
2510 	c->ev->base = base;
2511 	c->fd = fd;
2512 	c->buffer = buffer;
2513 	c->timeout = NULL;
2514 	c->tcp_is_reading = 0;
2515 	c->tcp_byte_count = 0;
2516 	c->tcp_parent = NULL;
2517 	c->max_tcp_count = 0;
2518 	c->cur_tcp_count = 0;
2519 	c->tcp_handlers = NULL;
2520 	c->tcp_free = NULL;
2521 	c->type = comm_udp;
2522 	c->tcp_do_close = 0;
2523 	c->do_not_close = 0;
2524 	c->tcp_do_toggle_rw = 0;
2525 	c->tcp_check_nb_connect = 0;
2526 #ifdef USE_MSG_FASTOPEN
2527 	c->tcp_do_fastopen = 0;
2528 #endif
2529 #ifdef USE_DNSCRYPT
2530 	c->dnscrypt = 0;
2531 	c->dnscrypt_buffer = buffer;
2532 #endif
2533 	c->inuse = 0;
2534 	c->callback = callback;
2535 	c->cb_arg = callback_arg;
2536 	evbits = UB_EV_READ | UB_EV_PERSIST;
2537 	/* ub_event stuff */
2538 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2539 		comm_point_udp_callback, c);
2540 	if(c->ev->ev == NULL) {
2541 		log_err("could not baseset udp event");
2542 		comm_point_delete(c);
2543 		return NULL;
2544 	}
2545 	if(fd!=-1 && ub_event_add(c->ev->ev, c->timeout) != 0 ) {
2546 		log_err("could not add udp event");
2547 		comm_point_delete(c);
2548 		return NULL;
2549 	}
2550 	return c;
2551 }
2552 
2553 struct comm_point*
2554 comm_point_create_udp_ancil(struct comm_base *base, int fd,
2555 	sldns_buffer* buffer,
2556 	comm_point_callback_type* callback, void* callback_arg)
2557 {
2558 	struct comm_point* c = (struct comm_point*)calloc(1,
2559 		sizeof(struct comm_point));
2560 	short evbits;
2561 	if(!c)
2562 		return NULL;
2563 	c->ev = (struct internal_event*)calloc(1,
2564 		sizeof(struct internal_event));
2565 	if(!c->ev) {
2566 		free(c);
2567 		return NULL;
2568 	}
2569 	c->ev->base = base;
2570 	c->fd = fd;
2571 	c->buffer = buffer;
2572 	c->timeout = NULL;
2573 	c->tcp_is_reading = 0;
2574 	c->tcp_byte_count = 0;
2575 	c->tcp_parent = NULL;
2576 	c->max_tcp_count = 0;
2577 	c->cur_tcp_count = 0;
2578 	c->tcp_handlers = NULL;
2579 	c->tcp_free = NULL;
2580 	c->type = comm_udp;
2581 	c->tcp_do_close = 0;
2582 	c->do_not_close = 0;
2583 #ifdef USE_DNSCRYPT
2584 	c->dnscrypt = 0;
2585 	c->dnscrypt_buffer = buffer;
2586 #endif
2587 	c->inuse = 0;
2588 	c->tcp_do_toggle_rw = 0;
2589 	c->tcp_check_nb_connect = 0;
2590 #ifdef USE_MSG_FASTOPEN
2591 	c->tcp_do_fastopen = 0;
2592 #endif
2593 	c->callback = callback;
2594 	c->cb_arg = callback_arg;
2595 	evbits = UB_EV_READ | UB_EV_PERSIST;
2596 	/* ub_event stuff */
2597 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2598 		comm_point_udp_ancil_callback, c);
2599 	if(c->ev->ev == NULL) {
2600 		log_err("could not baseset udp event");
2601 		comm_point_delete(c);
2602 		return NULL;
2603 	}
2604 	if(fd!=-1 && ub_event_add(c->ev->ev, c->timeout) != 0 ) {
2605 		log_err("could not add udp event");
2606 		comm_point_delete(c);
2607 		return NULL;
2608 	}
2609 	return c;
2610 }
2611 
2612 static struct comm_point*
2613 comm_point_create_tcp_handler(struct comm_base *base,
2614 	struct comm_point* parent, size_t bufsize,
2615 	struct sldns_buffer* spoolbuf, comm_point_callback_type* callback,
2616 	void* callback_arg)
2617 {
2618 	struct comm_point* c = (struct comm_point*)calloc(1,
2619 		sizeof(struct comm_point));
2620 	short evbits;
2621 	if(!c)
2622 		return NULL;
2623 	c->ev = (struct internal_event*)calloc(1,
2624 		sizeof(struct internal_event));
2625 	if(!c->ev) {
2626 		free(c);
2627 		return NULL;
2628 	}
2629 	c->ev->base = base;
2630 	c->fd = -1;
2631 	c->buffer = sldns_buffer_new(bufsize);
2632 	if(!c->buffer) {
2633 		free(c->ev);
2634 		free(c);
2635 		return NULL;
2636 	}
2637 	c->timeout = (struct timeval*)malloc(sizeof(struct timeval));
2638 	if(!c->timeout) {
2639 		sldns_buffer_free(c->buffer);
2640 		free(c->ev);
2641 		free(c);
2642 		return NULL;
2643 	}
2644 	c->tcp_is_reading = 0;
2645 	c->tcp_byte_count = 0;
2646 	c->tcp_parent = parent;
2647 	c->tcp_timeout_msec = parent->tcp_timeout_msec;
2648 	c->tcp_conn_limit = parent->tcp_conn_limit;
2649 	c->tcl_addr = NULL;
2650 	c->tcp_keepalive = 0;
2651 	c->max_tcp_count = 0;
2652 	c->cur_tcp_count = 0;
2653 	c->tcp_handlers = NULL;
2654 	c->tcp_free = NULL;
2655 	c->type = comm_tcp;
2656 	c->tcp_do_close = 0;
2657 	c->do_not_close = 0;
2658 	c->tcp_do_toggle_rw = 1;
2659 	c->tcp_check_nb_connect = 0;
2660 #ifdef USE_MSG_FASTOPEN
2661 	c->tcp_do_fastopen = 0;
2662 #endif
2663 #ifdef USE_DNSCRYPT
2664 	c->dnscrypt = 0;
2665 	/* We don't know just yet if this is a dnscrypt channel. Allocation
2666 	 * will be done when handling the callback. */
2667 	c->dnscrypt_buffer = c->buffer;
2668 #endif
2669 	c->repinfo.c = c;
2670 	c->callback = callback;
2671 	c->cb_arg = callback_arg;
2672 	if(spoolbuf) {
2673 		c->tcp_req_info = tcp_req_info_create(spoolbuf);
2674 		if(!c->tcp_req_info) {
2675 			log_err("could not create tcp commpoint");
2676 			sldns_buffer_free(c->buffer);
2677 			free(c->timeout);
2678 			free(c->ev);
2679 			free(c);
2680 			return NULL;
2681 		}
2682 		c->tcp_req_info->cp = c;
2683 		c->tcp_do_close = 1;
2684 		c->tcp_do_toggle_rw = 0;
2685 	}
2686 	/* add to parent free list */
2687 	c->tcp_free = parent->tcp_free;
2688 	parent->tcp_free = c;
2689 	/* ub_event stuff */
2690 	evbits = UB_EV_PERSIST | UB_EV_READ | UB_EV_TIMEOUT;
2691 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2692 		comm_point_tcp_handle_callback, c);
2693 	if(c->ev->ev == NULL)
2694 	{
2695 		log_err("could not basetset tcphdl event");
2696 		parent->tcp_free = c->tcp_free;
2697 		tcp_req_info_delete(c->tcp_req_info);
2698 		sldns_buffer_free(c->buffer);
2699 		free(c->timeout);
2700 		free(c->ev);
2701 		free(c);
2702 		return NULL;
2703 	}
2704 	return c;
2705 }
2706 
2707 struct comm_point*
2708 comm_point_create_tcp(struct comm_base *base, int fd, int num,
2709 	int idle_timeout, struct tcl_list* tcp_conn_limit, size_t bufsize,
2710 	struct sldns_buffer* spoolbuf, comm_point_callback_type* callback,
2711 	void* callback_arg)
2712 {
2713 	struct comm_point* c = (struct comm_point*)calloc(1,
2714 		sizeof(struct comm_point));
2715 	short evbits;
2716 	int i;
2717 	/* first allocate the TCP accept listener */
2718 	if(!c)
2719 		return NULL;
2720 	c->ev = (struct internal_event*)calloc(1,
2721 		sizeof(struct internal_event));
2722 	if(!c->ev) {
2723 		free(c);
2724 		return NULL;
2725 	}
2726 	c->ev->base = base;
2727 	c->fd = fd;
2728 	c->buffer = NULL;
2729 	c->timeout = NULL;
2730 	c->tcp_is_reading = 0;
2731 	c->tcp_byte_count = 0;
2732 	c->tcp_timeout_msec = idle_timeout;
2733 	c->tcp_conn_limit = tcp_conn_limit;
2734 	c->tcl_addr = NULL;
2735 	c->tcp_keepalive = 0;
2736 	c->tcp_parent = NULL;
2737 	c->max_tcp_count = num;
2738 	c->cur_tcp_count = 0;
2739 	c->tcp_handlers = (struct comm_point**)calloc((size_t)num,
2740 		sizeof(struct comm_point*));
2741 	if(!c->tcp_handlers) {
2742 		free(c->ev);
2743 		free(c);
2744 		return NULL;
2745 	}
2746 	c->tcp_free = NULL;
2747 	c->type = comm_tcp_accept;
2748 	c->tcp_do_close = 0;
2749 	c->do_not_close = 0;
2750 	c->tcp_do_toggle_rw = 0;
2751 	c->tcp_check_nb_connect = 0;
2752 #ifdef USE_MSG_FASTOPEN
2753 	c->tcp_do_fastopen = 0;
2754 #endif
2755 #ifdef USE_DNSCRYPT
2756 	c->dnscrypt = 0;
2757 	c->dnscrypt_buffer = NULL;
2758 #endif
2759 	c->callback = NULL;
2760 	c->cb_arg = NULL;
2761 	evbits = UB_EV_READ | UB_EV_PERSIST;
2762 	/* ub_event stuff */
2763 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2764 		comm_point_tcp_accept_callback, c);
2765 	if(c->ev->ev == NULL) {
2766 		log_err("could not baseset tcpacc event");
2767 		comm_point_delete(c);
2768 		return NULL;
2769 	}
2770 	if (ub_event_add(c->ev->ev, c->timeout) != 0) {
2771 		log_err("could not add tcpacc event");
2772 		comm_point_delete(c);
2773 		return NULL;
2774 	}
2775 	/* now prealloc the tcp handlers */
2776 	for(i=0; i<num; i++) {
2777 		c->tcp_handlers[i] = comm_point_create_tcp_handler(base,
2778 			c, bufsize, spoolbuf, callback, callback_arg);
2779 		if(!c->tcp_handlers[i]) {
2780 			comm_point_delete(c);
2781 			return NULL;
2782 		}
2783 	}
2784 
2785 	return c;
2786 }
2787 
2788 struct comm_point*
2789 comm_point_create_tcp_out(struct comm_base *base, size_t bufsize,
2790         comm_point_callback_type* callback, void* callback_arg)
2791 {
2792 	struct comm_point* c = (struct comm_point*)calloc(1,
2793 		sizeof(struct comm_point));
2794 	short evbits;
2795 	if(!c)
2796 		return NULL;
2797 	c->ev = (struct internal_event*)calloc(1,
2798 		sizeof(struct internal_event));
2799 	if(!c->ev) {
2800 		free(c);
2801 		return NULL;
2802 	}
2803 	c->ev->base = base;
2804 	c->fd = -1;
2805 	c->buffer = sldns_buffer_new(bufsize);
2806 	if(!c->buffer) {
2807 		free(c->ev);
2808 		free(c);
2809 		return NULL;
2810 	}
2811 	c->timeout = NULL;
2812 	c->tcp_is_reading = 0;
2813 	c->tcp_byte_count = 0;
2814 	c->tcp_timeout_msec = TCP_QUERY_TIMEOUT;
2815 	c->tcp_conn_limit = NULL;
2816 	c->tcl_addr = NULL;
2817 	c->tcp_keepalive = 0;
2818 	c->tcp_parent = NULL;
2819 	c->max_tcp_count = 0;
2820 	c->cur_tcp_count = 0;
2821 	c->tcp_handlers = NULL;
2822 	c->tcp_free = NULL;
2823 	c->type = comm_tcp;
2824 	c->tcp_do_close = 0;
2825 	c->do_not_close = 0;
2826 	c->tcp_do_toggle_rw = 1;
2827 	c->tcp_check_nb_connect = 1;
2828 #ifdef USE_MSG_FASTOPEN
2829 	c->tcp_do_fastopen = 1;
2830 #endif
2831 #ifdef USE_DNSCRYPT
2832 	c->dnscrypt = 0;
2833 	c->dnscrypt_buffer = c->buffer;
2834 #endif
2835 	c->repinfo.c = c;
2836 	c->callback = callback;
2837 	c->cb_arg = callback_arg;
2838 	evbits = UB_EV_PERSIST | UB_EV_WRITE;
2839 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2840 		comm_point_tcp_handle_callback, c);
2841 	if(c->ev->ev == NULL)
2842 	{
2843 		log_err("could not baseset tcpout event");
2844 		sldns_buffer_free(c->buffer);
2845 		free(c->ev);
2846 		free(c);
2847 		return NULL;
2848 	}
2849 
2850 	return c;
2851 }
2852 
2853 struct comm_point*
2854 comm_point_create_http_out(struct comm_base *base, size_t bufsize,
2855         comm_point_callback_type* callback, void* callback_arg,
2856 	sldns_buffer* temp)
2857 {
2858 	struct comm_point* c = (struct comm_point*)calloc(1,
2859 		sizeof(struct comm_point));
2860 	short evbits;
2861 	if(!c)
2862 		return NULL;
2863 	c->ev = (struct internal_event*)calloc(1,
2864 		sizeof(struct internal_event));
2865 	if(!c->ev) {
2866 		free(c);
2867 		return NULL;
2868 	}
2869 	c->ev->base = base;
2870 	c->fd = -1;
2871 	c->buffer = sldns_buffer_new(bufsize);
2872 	if(!c->buffer) {
2873 		free(c->ev);
2874 		free(c);
2875 		return NULL;
2876 	}
2877 	c->timeout = NULL;
2878 	c->tcp_is_reading = 0;
2879 	c->tcp_byte_count = 0;
2880 	c->tcp_parent = NULL;
2881 	c->max_tcp_count = 0;
2882 	c->cur_tcp_count = 0;
2883 	c->tcp_handlers = NULL;
2884 	c->tcp_free = NULL;
2885 	c->type = comm_http;
2886 	c->tcp_do_close = 0;
2887 	c->do_not_close = 0;
2888 	c->tcp_do_toggle_rw = 1;
2889 	c->tcp_check_nb_connect = 1;
2890 	c->http_in_headers = 1;
2891 	c->http_in_chunk_headers = 0;
2892 	c->http_is_chunked = 0;
2893 	c->http_temp = temp;
2894 #ifdef USE_MSG_FASTOPEN
2895 	c->tcp_do_fastopen = 1;
2896 #endif
2897 #ifdef USE_DNSCRYPT
2898 	c->dnscrypt = 0;
2899 	c->dnscrypt_buffer = c->buffer;
2900 #endif
2901 	c->repinfo.c = c;
2902 	c->callback = callback;
2903 	c->cb_arg = callback_arg;
2904 	evbits = UB_EV_PERSIST | UB_EV_WRITE;
2905 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2906 		comm_point_http_handle_callback, c);
2907 	if(c->ev->ev == NULL)
2908 	{
2909 		log_err("could not baseset tcpout event");
2910 #ifdef HAVE_SSL
2911 		SSL_free(c->ssl);
2912 #endif
2913 		sldns_buffer_free(c->buffer);
2914 		free(c->ev);
2915 		free(c);
2916 		return NULL;
2917 	}
2918 
2919 	return c;
2920 }
2921 
2922 struct comm_point*
2923 comm_point_create_local(struct comm_base *base, int fd, size_t bufsize,
2924         comm_point_callback_type* callback, void* callback_arg)
2925 {
2926 	struct comm_point* c = (struct comm_point*)calloc(1,
2927 		sizeof(struct comm_point));
2928 	short evbits;
2929 	if(!c)
2930 		return NULL;
2931 	c->ev = (struct internal_event*)calloc(1,
2932 		sizeof(struct internal_event));
2933 	if(!c->ev) {
2934 		free(c);
2935 		return NULL;
2936 	}
2937 	c->ev->base = base;
2938 	c->fd = fd;
2939 	c->buffer = sldns_buffer_new(bufsize);
2940 	if(!c->buffer) {
2941 		free(c->ev);
2942 		free(c);
2943 		return NULL;
2944 	}
2945 	c->timeout = NULL;
2946 	c->tcp_is_reading = 1;
2947 	c->tcp_byte_count = 0;
2948 	c->tcp_parent = NULL;
2949 	c->max_tcp_count = 0;
2950 	c->cur_tcp_count = 0;
2951 	c->tcp_handlers = NULL;
2952 	c->tcp_free = NULL;
2953 	c->type = comm_local;
2954 	c->tcp_do_close = 0;
2955 	c->do_not_close = 1;
2956 	c->tcp_do_toggle_rw = 0;
2957 	c->tcp_check_nb_connect = 0;
2958 #ifdef USE_MSG_FASTOPEN
2959 	c->tcp_do_fastopen = 0;
2960 #endif
2961 #ifdef USE_DNSCRYPT
2962 	c->dnscrypt = 0;
2963 	c->dnscrypt_buffer = c->buffer;
2964 #endif
2965 	c->callback = callback;
2966 	c->cb_arg = callback_arg;
2967 	/* ub_event stuff */
2968 	evbits = UB_EV_PERSIST | UB_EV_READ;
2969 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
2970 		comm_point_local_handle_callback, c);
2971 	if(c->ev->ev == NULL) {
2972 		log_err("could not baseset localhdl event");
2973 		free(c->ev);
2974 		free(c);
2975 		return NULL;
2976 	}
2977 	if (ub_event_add(c->ev->ev, c->timeout) != 0) {
2978 		log_err("could not add localhdl event");
2979 		ub_event_free(c->ev->ev);
2980 		free(c->ev);
2981 		free(c);
2982 		return NULL;
2983 	}
2984 	return c;
2985 }
2986 
2987 struct comm_point*
2988 comm_point_create_raw(struct comm_base* base, int fd, int writing,
2989 	comm_point_callback_type* callback, void* callback_arg)
2990 {
2991 	struct comm_point* c = (struct comm_point*)calloc(1,
2992 		sizeof(struct comm_point));
2993 	short evbits;
2994 	if(!c)
2995 		return NULL;
2996 	c->ev = (struct internal_event*)calloc(1,
2997 		sizeof(struct internal_event));
2998 	if(!c->ev) {
2999 		free(c);
3000 		return NULL;
3001 	}
3002 	c->ev->base = base;
3003 	c->fd = fd;
3004 	c->buffer = NULL;
3005 	c->timeout = NULL;
3006 	c->tcp_is_reading = 0;
3007 	c->tcp_byte_count = 0;
3008 	c->tcp_parent = NULL;
3009 	c->max_tcp_count = 0;
3010 	c->cur_tcp_count = 0;
3011 	c->tcp_handlers = NULL;
3012 	c->tcp_free = NULL;
3013 	c->type = comm_raw;
3014 	c->tcp_do_close = 0;
3015 	c->do_not_close = 1;
3016 	c->tcp_do_toggle_rw = 0;
3017 	c->tcp_check_nb_connect = 0;
3018 #ifdef USE_MSG_FASTOPEN
3019 	c->tcp_do_fastopen = 0;
3020 #endif
3021 #ifdef USE_DNSCRYPT
3022 	c->dnscrypt = 0;
3023 	c->dnscrypt_buffer = c->buffer;
3024 #endif
3025 	c->callback = callback;
3026 	c->cb_arg = callback_arg;
3027 	/* ub_event stuff */
3028 	if(writing)
3029 		evbits = UB_EV_PERSIST | UB_EV_WRITE;
3030 	else 	evbits = UB_EV_PERSIST | UB_EV_READ;
3031 	c->ev->ev = ub_event_new(base->eb->base, c->fd, evbits,
3032 		comm_point_raw_handle_callback, c);
3033 	if(c->ev->ev == NULL) {
3034 		log_err("could not baseset rawhdl event");
3035 		free(c->ev);
3036 		free(c);
3037 		return NULL;
3038 	}
3039 	if (ub_event_add(c->ev->ev, c->timeout) != 0) {
3040 		log_err("could not add rawhdl event");
3041 		ub_event_free(c->ev->ev);
3042 		free(c->ev);
3043 		free(c);
3044 		return NULL;
3045 	}
3046 	return c;
3047 }
3048 
3049 void
3050 comm_point_close(struct comm_point* c)
3051 {
3052 	if(!c)
3053 		return;
3054 	if(c->fd != -1) {
3055 		if(ub_event_del(c->ev->ev) != 0) {
3056 			log_err("could not event_del on close");
3057 		}
3058 	}
3059 	tcl_close_connection(c->tcl_addr);
3060 	if(c->tcp_req_info)
3061 		tcp_req_info_clear(c->tcp_req_info);
3062 	/* close fd after removing from event lists, or epoll.. is messed up */
3063 	if(c->fd != -1 && !c->do_not_close) {
3064 		if(c->type == comm_tcp || c->type == comm_http) {
3065 			/* delete sticky events for the fd, it gets closed */
3066 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_READ);
3067 			ub_winsock_tcp_wouldblock(c->ev->ev, UB_EV_WRITE);
3068 		}
3069 		verbose(VERB_ALGO, "close fd %d", c->fd);
3070 #ifndef USE_WINSOCK
3071 		close(c->fd);
3072 #else
3073 		closesocket(c->fd);
3074 #endif
3075 	}
3076 	c->fd = -1;
3077 }
3078 
3079 void
3080 comm_point_delete(struct comm_point* c)
3081 {
3082 	if(!c)
3083 		return;
3084 	if((c->type == comm_tcp || c->type == comm_http) && c->ssl) {
3085 #ifdef HAVE_SSL
3086 		SSL_shutdown(c->ssl);
3087 		SSL_free(c->ssl);
3088 #endif
3089 	}
3090 	comm_point_close(c);
3091 	if(c->tcp_handlers) {
3092 		int i;
3093 		for(i=0; i<c->max_tcp_count; i++)
3094 			comm_point_delete(c->tcp_handlers[i]);
3095 		free(c->tcp_handlers);
3096 	}
3097 	free(c->timeout);
3098 	if(c->type == comm_tcp || c->type == comm_local || c->type == comm_http) {
3099 		sldns_buffer_free(c->buffer);
3100 #ifdef USE_DNSCRYPT
3101 		if(c->dnscrypt && c->dnscrypt_buffer != c->buffer) {
3102 			sldns_buffer_free(c->dnscrypt_buffer);
3103 		}
3104 #endif
3105 		if(c->tcp_req_info) {
3106 			tcp_req_info_delete(c->tcp_req_info);
3107 		}
3108 	}
3109 	ub_event_free(c->ev->ev);
3110 	free(c->ev);
3111 	free(c);
3112 }
3113 
3114 void
3115 comm_point_send_reply(struct comm_reply *repinfo)
3116 {
3117 	struct sldns_buffer* buffer;
3118 	log_assert(repinfo && repinfo->c);
3119 #ifdef USE_DNSCRYPT
3120 	buffer = repinfo->c->dnscrypt_buffer;
3121 	if(!dnsc_handle_uncurved_request(repinfo)) {
3122 		return;
3123 	}
3124 #else
3125 	buffer = repinfo->c->buffer;
3126 #endif
3127 	if(repinfo->c->type == comm_udp) {
3128 		if(repinfo->srctype)
3129 			comm_point_send_udp_msg_if(repinfo->c,
3130 			buffer, (struct sockaddr*)&repinfo->addr,
3131 			repinfo->addrlen, repinfo);
3132 		else
3133 			comm_point_send_udp_msg(repinfo->c, buffer,
3134 			(struct sockaddr*)&repinfo->addr, repinfo->addrlen);
3135 #ifdef USE_DNSTAP
3136 		if(repinfo->c->dtenv != NULL &&
3137 		   repinfo->c->dtenv->log_client_response_messages)
3138 			dt_msg_send_client_response(repinfo->c->dtenv,
3139 			&repinfo->addr, repinfo->c->type, repinfo->c->buffer);
3140 #endif
3141 	} else {
3142 #ifdef USE_DNSTAP
3143 		if(repinfo->c->tcp_parent->dtenv != NULL &&
3144 		   repinfo->c->tcp_parent->dtenv->log_client_response_messages)
3145 			dt_msg_send_client_response(repinfo->c->tcp_parent->dtenv,
3146 			&repinfo->addr, repinfo->c->type, repinfo->c->buffer);
3147 #endif
3148 		if(repinfo->c->tcp_req_info) {
3149 			tcp_req_info_send_reply(repinfo->c->tcp_req_info);
3150 		} else {
3151 			comm_point_start_listening(repinfo->c, -1,
3152 				repinfo->c->tcp_timeout_msec);
3153 		}
3154 	}
3155 }
3156 
3157 void
3158 comm_point_drop_reply(struct comm_reply* repinfo)
3159 {
3160 	if(!repinfo)
3161 		return;
3162 	log_assert(repinfo && repinfo->c);
3163 	log_assert(repinfo->c->type != comm_tcp_accept);
3164 	if(repinfo->c->type == comm_udp)
3165 		return;
3166 	if(repinfo->c->tcp_req_info)
3167 		repinfo->c->tcp_req_info->is_drop = 1;
3168 	reclaim_tcp_handler(repinfo->c);
3169 }
3170 
3171 void
3172 comm_point_stop_listening(struct comm_point* c)
3173 {
3174 	verbose(VERB_ALGO, "comm point stop listening %d", c->fd);
3175 	if(ub_event_del(c->ev->ev) != 0) {
3176 		log_err("event_del error to stoplisten");
3177 	}
3178 }
3179 
3180 void
3181 comm_point_start_listening(struct comm_point* c, int newfd, int msec)
3182 {
3183 	verbose(VERB_ALGO, "comm point start listening %d (%d msec)",
3184 		c->fd==-1?newfd:c->fd, msec);
3185 	if(c->type == comm_tcp_accept && !c->tcp_free) {
3186 		/* no use to start listening no free slots. */
3187 		return;
3188 	}
3189 	if(msec != -1 && msec != 0) {
3190 		if(!c->timeout) {
3191 			c->timeout = (struct timeval*)malloc(sizeof(
3192 				struct timeval));
3193 			if(!c->timeout) {
3194 				log_err("cpsl: malloc failed. No net read.");
3195 				return;
3196 			}
3197 		}
3198 		ub_event_add_bits(c->ev->ev, UB_EV_TIMEOUT);
3199 #ifndef S_SPLINT_S /* splint fails on struct timeval. */
3200 		c->timeout->tv_sec = msec/1000;
3201 		c->timeout->tv_usec = (msec%1000)*1000;
3202 #endif /* S_SPLINT_S */
3203 	}
3204 	if(c->type == comm_tcp || c->type == comm_http) {
3205 		ub_event_del_bits(c->ev->ev, UB_EV_READ|UB_EV_WRITE);
3206 		if(c->tcp_is_reading)
3207 			ub_event_add_bits(c->ev->ev, UB_EV_READ);
3208 		else	ub_event_add_bits(c->ev->ev, UB_EV_WRITE);
3209 	}
3210 	if(newfd != -1) {
3211 		if(c->fd != -1) {
3212 #ifndef USE_WINSOCK
3213 			close(c->fd);
3214 #else
3215 			closesocket(c->fd);
3216 #endif
3217 		}
3218 		c->fd = newfd;
3219 		ub_event_set_fd(c->ev->ev, c->fd);
3220 	}
3221 	if(ub_event_add(c->ev->ev, msec==0?NULL:c->timeout) != 0) {
3222 		log_err("event_add failed. in cpsl.");
3223 	}
3224 }
3225 
3226 void comm_point_listen_for_rw(struct comm_point* c, int rd, int wr)
3227 {
3228 	verbose(VERB_ALGO, "comm point listen_for_rw %d %d", c->fd, wr);
3229 	if(ub_event_del(c->ev->ev) != 0) {
3230 		log_err("event_del error to cplf");
3231 	}
3232 	ub_event_del_bits(c->ev->ev, UB_EV_READ|UB_EV_WRITE);
3233 	if(rd) ub_event_add_bits(c->ev->ev, UB_EV_READ);
3234 	if(wr) ub_event_add_bits(c->ev->ev, UB_EV_WRITE);
3235 	if(ub_event_add(c->ev->ev, c->timeout) != 0) {
3236 		log_err("event_add failed. in cplf.");
3237 	}
3238 }
3239 
3240 size_t comm_point_get_mem(struct comm_point* c)
3241 {
3242 	size_t s;
3243 	if(!c)
3244 		return 0;
3245 	s = sizeof(*c) + sizeof(*c->ev);
3246 	if(c->timeout)
3247 		s += sizeof(*c->timeout);
3248 	if(c->type == comm_tcp || c->type == comm_local) {
3249 		s += sizeof(*c->buffer) + sldns_buffer_capacity(c->buffer);
3250 #ifdef USE_DNSCRYPT
3251 		s += sizeof(*c->dnscrypt_buffer);
3252 		if(c->buffer != c->dnscrypt_buffer) {
3253 			s += sldns_buffer_capacity(c->dnscrypt_buffer);
3254 		}
3255 #endif
3256 	}
3257 	if(c->type == comm_tcp_accept) {
3258 		int i;
3259 		for(i=0; i<c->max_tcp_count; i++)
3260 			s += comm_point_get_mem(c->tcp_handlers[i]);
3261 	}
3262 	return s;
3263 }
3264 
3265 struct comm_timer*
3266 comm_timer_create(struct comm_base* base, void (*cb)(void*), void* cb_arg)
3267 {
3268 	struct internal_timer *tm = (struct internal_timer*)calloc(1,
3269 		sizeof(struct internal_timer));
3270 	if(!tm) {
3271 		log_err("malloc failed");
3272 		return NULL;
3273 	}
3274 	tm->super.ev_timer = tm;
3275 	tm->base = base;
3276 	tm->super.callback = cb;
3277 	tm->super.cb_arg = cb_arg;
3278 	tm->ev = ub_event_new(base->eb->base, -1, UB_EV_TIMEOUT,
3279 		comm_timer_callback, &tm->super);
3280 	if(tm->ev == NULL) {
3281 		log_err("timer_create: event_base_set failed.");
3282 		free(tm);
3283 		return NULL;
3284 	}
3285 	return &tm->super;
3286 }
3287 
3288 void
3289 comm_timer_disable(struct comm_timer* timer)
3290 {
3291 	if(!timer)
3292 		return;
3293 	ub_timer_del(timer->ev_timer->ev);
3294 	timer->ev_timer->enabled = 0;
3295 }
3296 
3297 void
3298 comm_timer_set(struct comm_timer* timer, struct timeval* tv)
3299 {
3300 	log_assert(tv);
3301 	if(timer->ev_timer->enabled)
3302 		comm_timer_disable(timer);
3303 	if(ub_timer_add(timer->ev_timer->ev, timer->ev_timer->base->eb->base,
3304 		comm_timer_callback, timer, tv) != 0)
3305 		log_err("comm_timer_set: evtimer_add failed.");
3306 	timer->ev_timer->enabled = 1;
3307 }
3308 
3309 void
3310 comm_timer_delete(struct comm_timer* timer)
3311 {
3312 	if(!timer)
3313 		return;
3314 	comm_timer_disable(timer);
3315 	/* Free the sub struct timer->ev_timer derived from the super struct timer.
3316 	 * i.e. assert(timer == timer->ev_timer)
3317 	 */
3318 	ub_event_free(timer->ev_timer->ev);
3319 	free(timer->ev_timer);
3320 }
3321 
3322 void
3323 comm_timer_callback(int ATTR_UNUSED(fd), short event, void* arg)
3324 {
3325 	struct comm_timer* tm = (struct comm_timer*)arg;
3326 	if(!(event&UB_EV_TIMEOUT))
3327 		return;
3328 	ub_comm_base_now(tm->ev_timer->base);
3329 	tm->ev_timer->enabled = 0;
3330 	fptr_ok(fptr_whitelist_comm_timer(tm->callback));
3331 	(*tm->callback)(tm->cb_arg);
3332 }
3333 
3334 int
3335 comm_timer_is_set(struct comm_timer* timer)
3336 {
3337 	return (int)timer->ev_timer->enabled;
3338 }
3339 
3340 size_t
3341 comm_timer_get_mem(struct comm_timer* ATTR_UNUSED(timer))
3342 {
3343 	return sizeof(struct internal_timer);
3344 }
3345 
3346 struct comm_signal*
3347 comm_signal_create(struct comm_base* base,
3348         void (*callback)(int, void*), void* cb_arg)
3349 {
3350 	struct comm_signal* com = (struct comm_signal*)malloc(
3351 		sizeof(struct comm_signal));
3352 	if(!com) {
3353 		log_err("malloc failed");
3354 		return NULL;
3355 	}
3356 	com->base = base;
3357 	com->callback = callback;
3358 	com->cb_arg = cb_arg;
3359 	com->ev_signal = NULL;
3360 	return com;
3361 }
3362 
3363 void
3364 comm_signal_callback(int sig, short event, void* arg)
3365 {
3366 	struct comm_signal* comsig = (struct comm_signal*)arg;
3367 	if(!(event & UB_EV_SIGNAL))
3368 		return;
3369 	ub_comm_base_now(comsig->base);
3370 	fptr_ok(fptr_whitelist_comm_signal(comsig->callback));
3371 	(*comsig->callback)(sig, comsig->cb_arg);
3372 }
3373 
3374 int
3375 comm_signal_bind(struct comm_signal* comsig, int sig)
3376 {
3377 	struct internal_signal* entry = (struct internal_signal*)calloc(1,
3378 		sizeof(struct internal_signal));
3379 	if(!entry) {
3380 		log_err("malloc failed");
3381 		return 0;
3382 	}
3383 	log_assert(comsig);
3384 	/* add signal event */
3385 	entry->ev = ub_signal_new(comsig->base->eb->base, sig,
3386 		comm_signal_callback, comsig);
3387 	if(entry->ev == NULL) {
3388 		log_err("Could not create signal event");
3389 		free(entry);
3390 		return 0;
3391 	}
3392 	if(ub_signal_add(entry->ev, NULL) != 0) {
3393 		log_err("Could not add signal handler");
3394 		ub_event_free(entry->ev);
3395 		free(entry);
3396 		return 0;
3397 	}
3398 	/* link into list */
3399 	entry->next = comsig->ev_signal;
3400 	comsig->ev_signal = entry;
3401 	return 1;
3402 }
3403 
3404 void
3405 comm_signal_delete(struct comm_signal* comsig)
3406 {
3407 	struct internal_signal* p, *np;
3408 	if(!comsig)
3409 		return;
3410 	p=comsig->ev_signal;
3411 	while(p) {
3412 		np = p->next;
3413 		ub_signal_del(p->ev);
3414 		ub_event_free(p->ev);
3415 		free(p);
3416 		p = np;
3417 	}
3418 	free(comsig);
3419 }
3420