xref: /freebsd/sbin/hastd/proto_tcp.c (revision d184218c) 
1 /*-
2  * Copyright (c) 2009-2010 The FreeBSD Foundation
3  * Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
4  * All rights reserved.
5  *
6  * This software was developed by Pawel Jakub Dawidek under sponsorship from
7  * the FreeBSD Foundation.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/param.h>	/* MAXHOSTNAMELEN */
35 #include <sys/socket.h>
36 
37 #include <arpa/inet.h>
38 
39 #include <netinet/in.h>
40 #include <netinet/tcp.h>
41 
42 #include <errno.h>
43 #include <fcntl.h>
44 #include <netdb.h>
45 #include <stdbool.h>
46 #include <stdint.h>
47 #include <stdio.h>
48 #include <string.h>
49 #include <unistd.h>
50 
51 #include "pjdlog.h"
52 #include "proto_impl.h"
53 #include "subr.h"
54 
55 #define	TCP_CTX_MAGIC	0x7c41c
56 struct tcp_ctx {
57 	int			tc_magic;
58 	struct sockaddr_storage	tc_sa;
59 	int			tc_fd;
60 	int			tc_side;
61 #define	TCP_SIDE_CLIENT		0
62 #define	TCP_SIDE_SERVER_LISTEN	1
63 #define	TCP_SIDE_SERVER_WORK	2
64 };
65 
66 static int tcp_connect_wait(void *ctx, int timeout);
67 static void tcp_close(void *ctx);
68 
69 /*
70  * Function converts the given string to unsigned number.
71  */
72 static int
73 numfromstr(const char *str, intmax_t minnum, intmax_t maxnum, intmax_t *nump)
74 {
75 	intmax_t digit, num;
76 
77 	if (str[0] == '\0')
78 		goto invalid;	/* Empty string. */
79 	num = 0;
80 	for (; *str != '\0'; str++) {
81 		if (*str < '0' || *str > '9')
82 			goto invalid;	/* Non-digit character. */
83 		digit = *str - '0';
84 		if (num > num * 10 + digit)
85 			goto invalid;	/* Overflow. */
86 		num = num * 10 + digit;
87 		if (num > maxnum)
88 			goto invalid;	/* Too big. */
89 	}
90 	if (num < minnum)
91 		goto invalid;	/* Too small. */
92 	*nump = num;
93 	return (0);
94 invalid:
95 	errno = EINVAL;
96 	return (-1);
97 }
98 
99 static int
100 tcp_addr(const char *addr, int defport, struct sockaddr_storage *sap)
101 {
102 	char iporhost[MAXHOSTNAMELEN], portstr[6];
103 	struct addrinfo hints;
104 	struct addrinfo *res;
105 	const char *pp;
106 	intmax_t port;
107 	size_t size;
108 	int error;
109 
110 	if (addr == NULL)
111 		return (-1);
112 
113 	bzero(&hints, sizeof(hints));
114 	hints.ai_flags = AI_ADDRCONFIG | AI_NUMERICSERV;
115 	hints.ai_family = PF_UNSPEC;
116 	hints.ai_socktype = SOCK_STREAM;
117 	hints.ai_protocol = IPPROTO_TCP;
118 
119 	if (strncasecmp(addr, "tcp4://", 7) == 0) {
120 		addr += 7;
121 		hints.ai_family = PF_INET;
122 	} else if (strncasecmp(addr, "tcp6://", 7) == 0) {
123 		addr += 7;
124 		hints.ai_family = PF_INET6;
125 	} else if (strncasecmp(addr, "tcp://", 6) == 0) {
126 		addr += 6;
127 	} else {
128 		/*
129 		 * Because TCP is the default assume IP or host is given without
130 		 * prefix.
131 		 */
132 	}
133 
134 	/*
135 	 * Extract optional port.
136 	 * There are three cases to consider.
137 	 * 1. hostname with port, eg. freefall.freebsd.org:8457
138 	 * 2. IPv4 address with port, eg. 192.168.0.101:8457
139 	 * 3. IPv6 address with port, eg. [fe80::1]:8457
140 	 * We discover IPv6 address by checking for two colons and if port is
141 	 * given, the address has to start with [.
142 	 */
143 	pp = NULL;
144 	if (strchr(addr, ':') != strrchr(addr, ':')) {
145 		if (addr[0] == '[')
146 			pp = strrchr(addr, ':');
147 	} else {
148 		pp = strrchr(addr, ':');
149 	}
150 	if (pp == NULL) {
151 		/* Port not given, use the default. */
152 		port = defport;
153 	} else {
154 		if (numfromstr(pp + 1, 1, 65535, &port) == -1)
155 			return (errno);
156 	}
157 	(void)snprintf(portstr, sizeof(portstr), "%jd", (intmax_t)port);
158 	/* Extract host name or IP address. */
159 	if (pp == NULL) {
160 		size = sizeof(iporhost);
161 		if (strlcpy(iporhost, addr, size) >= size)
162 			return (ENAMETOOLONG);
163 	} else if (addr[0] == '[' && pp[-1] == ']') {
164 		size = (size_t)(pp - addr - 2 + 1);
165 		if (size > sizeof(iporhost))
166 			return (ENAMETOOLONG);
167 		(void)strlcpy(iporhost, addr + 1, size);
168 	} else {
169 		size = (size_t)(pp - addr + 1);
170 		if (size > sizeof(iporhost))
171 			return (ENAMETOOLONG);
172 		(void)strlcpy(iporhost, addr, size);
173 	}
174 
175 	error = getaddrinfo(iporhost, portstr, &hints, &res);
176 	if (error != 0) {
177 		pjdlog_debug(1, "getaddrinfo(%s, %s) failed: %s.", iporhost,
178 		    portstr, gai_strerror(error));
179 		return (EINVAL);
180 	}
181 	if (res == NULL)
182 		return (ENOENT);
183 
184 	memcpy(sap, res->ai_addr, res->ai_addrlen);
185 
186 	freeaddrinfo(res);
187 
188 	return (0);
189 }
190 
191 static int
192 tcp_setup_new(const char *addr, int side, void **ctxp)
193 {
194 	struct tcp_ctx *tctx;
195 	int ret, nodelay;
196 
197 	PJDLOG_ASSERT(addr != NULL);
198 	PJDLOG_ASSERT(side == TCP_SIDE_CLIENT ||
199 	    side == TCP_SIDE_SERVER_LISTEN);
200 	PJDLOG_ASSERT(ctxp != NULL);
201 
202 	tctx = malloc(sizeof(*tctx));
203 	if (tctx == NULL)
204 		return (errno);
205 
206 	/* Parse given address. */
207 	if ((ret = tcp_addr(addr, PROTO_TCP_DEFAULT_PORT, &tctx->tc_sa)) != 0) {
208 		free(tctx);
209 		return (ret);
210 	}
211 
212 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
213 
214 	tctx->tc_fd = socket(tctx->tc_sa.ss_family, SOCK_STREAM, 0);
215 	if (tctx->tc_fd == -1) {
216 		ret = errno;
217 		free(tctx);
218 		return (ret);
219 	}
220 
221 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
222 
223 	/* Socket settings. */
224 	nodelay = 1;
225 	if (setsockopt(tctx->tc_fd, IPPROTO_TCP, TCP_NODELAY, &nodelay,
226 	    sizeof(nodelay)) == -1) {
227 		pjdlog_errno(LOG_WARNING, "Unable to set TCP_NOELAY");
228 	}
229 
230 	tctx->tc_side = side;
231 	tctx->tc_magic = TCP_CTX_MAGIC;
232 	*ctxp = tctx;
233 
234 	return (0);
235 }
236 
237 static int
238 tcp_setup_wrap(int fd, int side, void **ctxp)
239 {
240 	struct tcp_ctx *tctx;
241 
242 	PJDLOG_ASSERT(fd >= 0);
243 	PJDLOG_ASSERT(side == TCP_SIDE_CLIENT ||
244 	    side == TCP_SIDE_SERVER_WORK);
245 	PJDLOG_ASSERT(ctxp != NULL);
246 
247 	tctx = malloc(sizeof(*tctx));
248 	if (tctx == NULL)
249 		return (errno);
250 
251 	tctx->tc_fd = fd;
252 	tctx->tc_sa.ss_family = AF_UNSPEC;
253 	tctx->tc_side = side;
254 	tctx->tc_magic = TCP_CTX_MAGIC;
255 	*ctxp = tctx;
256 
257 	return (0);
258 }
259 
260 static int
261 tcp_client(const char *srcaddr, const char *dstaddr, void **ctxp)
262 {
263 	struct tcp_ctx *tctx;
264 	struct sockaddr_storage sa;
265 	int ret;
266 
267 	ret = tcp_setup_new(dstaddr, TCP_SIDE_CLIENT, ctxp);
268 	if (ret != 0)
269 		return (ret);
270 	tctx = *ctxp;
271 	if (srcaddr == NULL)
272 		return (0);
273 	ret = tcp_addr(srcaddr, 0, &sa);
274 	if (ret != 0) {
275 		tcp_close(tctx);
276 		return (ret);
277 	}
278 	if (bind(tctx->tc_fd, (struct sockaddr *)&sa, sa.ss_len) == -1) {
279 		ret = errno;
280 		tcp_close(tctx);
281 		return (ret);
282 	}
283 	return (0);
284 }
285 
286 static int
287 tcp_connect(void *ctx, int timeout)
288 {
289 	struct tcp_ctx *tctx = ctx;
290 	int error, flags;
291 
292 	PJDLOG_ASSERT(tctx != NULL);
293 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
294 	PJDLOG_ASSERT(tctx->tc_side == TCP_SIDE_CLIENT);
295 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
296 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
297 	PJDLOG_ASSERT(timeout >= -1);
298 
299 	flags = fcntl(tctx->tc_fd, F_GETFL);
300 	if (flags == -1) {
301 		pjdlog_common(LOG_DEBUG, 1, errno, "fcntl(F_GETFL) failed");
302 		return (errno);
303 	}
304 	/*
305 	 * We make socket non-blocking so we can handle connection timeout
306 	 * manually.
307 	 */
308 	flags |= O_NONBLOCK;
309 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
310 		pjdlog_common(LOG_DEBUG, 1, errno,
311 		    "fcntl(F_SETFL, O_NONBLOCK) failed");
312 		return (errno);
313 	}
314 
315 	if (connect(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
316 	    tctx->tc_sa.ss_len) == 0) {
317 		if (timeout == -1)
318 			return (0);
319 		error = 0;
320 		goto done;
321 	}
322 	if (errno != EINPROGRESS) {
323 		error = errno;
324 		pjdlog_common(LOG_DEBUG, 1, errno, "connect() failed");
325 		goto done;
326 	}
327 	if (timeout == -1)
328 		return (0);
329 	return (tcp_connect_wait(ctx, timeout));
330 done:
331 	flags &= ~O_NONBLOCK;
332 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
333 		if (error == 0)
334 			error = errno;
335 		pjdlog_common(LOG_DEBUG, 1, errno,
336 		    "fcntl(F_SETFL, ~O_NONBLOCK) failed");
337 	}
338 	return (error);
339 }
340 
341 static int
342 tcp_connect_wait(void *ctx, int timeout)
343 {
344 	struct tcp_ctx *tctx = ctx;
345 	struct timeval tv;
346 	fd_set fdset;
347 	socklen_t esize;
348 	int error, flags, ret;
349 
350 	PJDLOG_ASSERT(tctx != NULL);
351 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
352 	PJDLOG_ASSERT(tctx->tc_side == TCP_SIDE_CLIENT);
353 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
354 	PJDLOG_ASSERT(timeout >= 0);
355 
356 	tv.tv_sec = timeout;
357 	tv.tv_usec = 0;
358 again:
359 	FD_ZERO(&fdset);
360 	FD_SET(tctx->tc_fd, &fdset);
361 	ret = select(tctx->tc_fd + 1, NULL, &fdset, NULL, &tv);
362 	if (ret == 0) {
363 		error = ETIMEDOUT;
364 		goto done;
365 	} else if (ret == -1) {
366 		if (errno == EINTR)
367 			goto again;
368 		error = errno;
369 		pjdlog_common(LOG_DEBUG, 1, errno, "select() failed");
370 		goto done;
371 	}
372 	PJDLOG_ASSERT(ret > 0);
373 	PJDLOG_ASSERT(FD_ISSET(tctx->tc_fd, &fdset));
374 	esize = sizeof(error);
375 	if (getsockopt(tctx->tc_fd, SOL_SOCKET, SO_ERROR, &error,
376 	    &esize) == -1) {
377 		error = errno;
378 		pjdlog_common(LOG_DEBUG, 1, errno,
379 		    "getsockopt(SO_ERROR) failed");
380 		goto done;
381 	}
382 	if (error != 0) {
383 		pjdlog_common(LOG_DEBUG, 1, error,
384 		    "getsockopt(SO_ERROR) returned error");
385 		goto done;
386 	}
387 	error = 0;
388 done:
389 	flags = fcntl(tctx->tc_fd, F_GETFL);
390 	if (flags == -1) {
391 		if (error == 0)
392 			error = errno;
393 		pjdlog_common(LOG_DEBUG, 1, errno, "fcntl(F_GETFL) failed");
394 		return (error);
395 	}
396 	flags &= ~O_NONBLOCK;
397 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
398 		if (error == 0)
399 			error = errno;
400 		pjdlog_common(LOG_DEBUG, 1, errno,
401 		    "fcntl(F_SETFL, ~O_NONBLOCK) failed");
402 	}
403 	return (error);
404 }
405 
406 static int
407 tcp_server(const char *addr, void **ctxp)
408 {
409 	struct tcp_ctx *tctx;
410 	int ret, val;
411 
412 	ret = tcp_setup_new(addr, TCP_SIDE_SERVER_LISTEN, ctxp);
413 	if (ret != 0)
414 		return (ret);
415 
416 	tctx = *ctxp;
417 
418 	val = 1;
419 	/* Ignore failure. */
420 	(void)setsockopt(tctx->tc_fd, SOL_SOCKET, SO_REUSEADDR, &val,
421 	   sizeof(val));
422 
423 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
424 
425 	if (bind(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
426 	    tctx->tc_sa.ss_len) == -1) {
427 		ret = errno;
428 		tcp_close(tctx);
429 		return (ret);
430 	}
431 	if (listen(tctx->tc_fd, 8) == -1) {
432 		ret = errno;
433 		tcp_close(tctx);
434 		return (ret);
435 	}
436 
437 	return (0);
438 }
439 
440 static int
441 tcp_accept(void *ctx, void **newctxp)
442 {
443 	struct tcp_ctx *tctx = ctx;
444 	struct tcp_ctx *newtctx;
445 	socklen_t fromlen;
446 	int ret;
447 
448 	PJDLOG_ASSERT(tctx != NULL);
449 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
450 	PJDLOG_ASSERT(tctx->tc_side == TCP_SIDE_SERVER_LISTEN);
451 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
452 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
453 
454 	newtctx = malloc(sizeof(*newtctx));
455 	if (newtctx == NULL)
456 		return (errno);
457 
458 	fromlen = tctx->tc_sa.ss_len;
459 	newtctx->tc_fd = accept(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
460 	    &fromlen);
461 	if (newtctx->tc_fd == -1) {
462 		ret = errno;
463 		free(newtctx);
464 		return (ret);
465 	}
466 
467 	newtctx->tc_side = TCP_SIDE_SERVER_WORK;
468 	newtctx->tc_magic = TCP_CTX_MAGIC;
469 	*newctxp = newtctx;
470 
471 	return (0);
472 }
473 
474 static int
475 tcp_wrap(int fd, bool client, void **ctxp)
476 {
477 
478 	return (tcp_setup_wrap(fd,
479 	    client ? TCP_SIDE_CLIENT : TCP_SIDE_SERVER_WORK, ctxp));
480 }
481 
482 static int
483 tcp_send(void *ctx, const unsigned char *data, size_t size, int fd)
484 {
485 	struct tcp_ctx *tctx = ctx;
486 
487 	PJDLOG_ASSERT(tctx != NULL);
488 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
489 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
490 	PJDLOG_ASSERT(fd == -1);
491 
492 	return (proto_common_send(tctx->tc_fd, data, size, -1));
493 }
494 
495 static int
496 tcp_recv(void *ctx, unsigned char *data, size_t size, int *fdp)
497 {
498 	struct tcp_ctx *tctx = ctx;
499 
500 	PJDLOG_ASSERT(tctx != NULL);
501 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
502 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
503 	PJDLOG_ASSERT(fdp == NULL);
504 
505 	return (proto_common_recv(tctx->tc_fd, data, size, NULL));
506 }
507 
508 static int
509 tcp_descriptor(const void *ctx)
510 {
511 	const struct tcp_ctx *tctx = ctx;
512 
513 	PJDLOG_ASSERT(tctx != NULL);
514 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
515 
516 	return (tctx->tc_fd);
517 }
518 
519 static bool
520 tcp_address_match(const void *ctx, const char *addr)
521 {
522 	const struct tcp_ctx *tctx = ctx;
523 	struct sockaddr_storage sa1, sa2;
524 	socklen_t salen;
525 
526 	PJDLOG_ASSERT(tctx != NULL);
527 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
528 
529 	if (tcp_addr(addr, PROTO_TCP_DEFAULT_PORT, &sa1) != 0)
530 		return (false);
531 
532 	salen = sizeof(sa2);
533 	if (getpeername(tctx->tc_fd, (struct sockaddr *)&sa2, &salen) == -1)
534 		return (false);
535 
536 	if (sa1.ss_family != sa2.ss_family || sa1.ss_len != sa2.ss_len)
537 		return (false);
538 
539 	switch (sa1.ss_family) {
540 	case AF_INET:
541 	    {
542 		struct sockaddr_in *sin1, *sin2;
543 
544 		sin1 = (struct sockaddr_in *)&sa1;
545 		sin2 = (struct sockaddr_in *)&sa2;
546 
547 		return (memcmp(&sin1->sin_addr, &sin2->sin_addr,
548 		    sizeof(sin1->sin_addr)) == 0);
549 	    }
550 	case AF_INET6:
551 	    {
552 		struct sockaddr_in6 *sin1, *sin2;
553 
554 		sin1 = (struct sockaddr_in6 *)&sa1;
555 		sin2 = (struct sockaddr_in6 *)&sa2;
556 
557 		return (memcmp(&sin1->sin6_addr, &sin2->sin6_addr,
558 		    sizeof(sin1->sin6_addr)) == 0);
559 	    }
560 	default:
561 		return (false);
562 	}
563 }
564 
565 static void
566 tcp_local_address(const void *ctx, char *addr, size_t size)
567 {
568 	const struct tcp_ctx *tctx = ctx;
569 	struct sockaddr_storage sa;
570 	socklen_t salen;
571 
572 	PJDLOG_ASSERT(tctx != NULL);
573 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
574 
575 	salen = sizeof(sa);
576 	if (getsockname(tctx->tc_fd, (struct sockaddr *)&sa, &salen) == -1) {
577 		PJDLOG_VERIFY(strlcpy(addr, "N/A", size) < size);
578 		return;
579 	}
580 	PJDLOG_VERIFY(snprintf(addr, size, "tcp://%S", &sa) < (ssize_t)size);
581 }
582 
583 static void
584 tcp_remote_address(const void *ctx, char *addr, size_t size)
585 {
586 	const struct tcp_ctx *tctx = ctx;
587 	struct sockaddr_storage sa;
588 	socklen_t salen;
589 
590 	PJDLOG_ASSERT(tctx != NULL);
591 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
592 
593 	salen = sizeof(sa);
594 	if (getpeername(tctx->tc_fd, (struct sockaddr *)&sa, &salen) == -1) {
595 		PJDLOG_VERIFY(strlcpy(addr, "N/A", size) < size);
596 		return;
597 	}
598 	PJDLOG_VERIFY(snprintf(addr, size, "tcp://%S", &sa) < (ssize_t)size);
599 }
600 
601 static void
602 tcp_close(void *ctx)
603 {
604 	struct tcp_ctx *tctx = ctx;
605 
606 	PJDLOG_ASSERT(tctx != NULL);
607 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
608 
609 	if (tctx->tc_fd >= 0)
610 		close(tctx->tc_fd);
611 	tctx->tc_magic = 0;
612 	free(tctx);
613 }
614 
615 static struct proto tcp_proto = {
616 	.prt_name = "tcp",
617 	.prt_client = tcp_client,
618 	.prt_connect = tcp_connect,
619 	.prt_connect_wait = tcp_connect_wait,
620 	.prt_server = tcp_server,
621 	.prt_accept = tcp_accept,
622 	.prt_wrap = tcp_wrap,
623 	.prt_send = tcp_send,
624 	.prt_recv = tcp_recv,
625 	.prt_descriptor = tcp_descriptor,
626 	.prt_address_match = tcp_address_match,
627 	.prt_local_address = tcp_local_address,
628 	.prt_remote_address = tcp_remote_address,
629 	.prt_close = tcp_close
630 };
631 
632 static __constructor void
633 tcp_ctor(void)
634 {
635 
636 	proto_register(&tcp_proto, true);
637 }
638