xref: /freebsd/sbin/hastd/proto_tcp.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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) < 0)
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) < 0) {
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 		KEEP_ERRNO(pjdlog_common(LOG_DEBUG, 1, errno,
302 		    "fcntl(F_GETFL) failed"));
303 		return (errno);
304 	}
305 	/*
306 	 * We make socket non-blocking so we can handle connection timeout
307 	 * manually.
308 	 */
309 	flags |= O_NONBLOCK;
310 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
311 		KEEP_ERRNO(pjdlog_common(LOG_DEBUG, 1, errno,
312 		    "fcntl(F_SETFL, O_NONBLOCK) failed"));
313 		return (errno);
314 	}
315 
316 	if (connect(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
317 	    tctx->tc_sa.ss_len) == 0) {
318 		if (timeout == -1)
319 			return (0);
320 		error = 0;
321 		goto done;
322 	}
323 	if (errno != EINPROGRESS) {
324 		error = errno;
325 		pjdlog_common(LOG_DEBUG, 1, errno, "connect() failed");
326 		goto done;
327 	}
328 	if (timeout == -1)
329 		return (0);
330 	return (tcp_connect_wait(ctx, timeout));
331 done:
332 	flags &= ~O_NONBLOCK;
333 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
334 		if (error == 0)
335 			error = errno;
336 		pjdlog_common(LOG_DEBUG, 1, errno,
337 		    "fcntl(F_SETFL, ~O_NONBLOCK) failed");
338 	}
339 	return (error);
340 }
341 
342 static int
343 tcp_connect_wait(void *ctx, int timeout)
344 {
345 	struct tcp_ctx *tctx = ctx;
346 	struct timeval tv;
347 	fd_set fdset;
348 	socklen_t esize;
349 	int error, flags, ret;
350 
351 	PJDLOG_ASSERT(tctx != NULL);
352 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
353 	PJDLOG_ASSERT(tctx->tc_side == TCP_SIDE_CLIENT);
354 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
355 	PJDLOG_ASSERT(timeout >= 0);
356 
357 	tv.tv_sec = timeout;
358 	tv.tv_usec = 0;
359 again:
360 	FD_ZERO(&fdset);
361 	FD_SET(tctx->tc_fd, &fdset);
362 	ret = select(tctx->tc_fd + 1, NULL, &fdset, NULL, &tv);
363 	if (ret == 0) {
364 		error = ETIMEDOUT;
365 		goto done;
366 	} else if (ret == -1) {
367 		if (errno == EINTR)
368 			goto again;
369 		error = errno;
370 		pjdlog_common(LOG_DEBUG, 1, errno, "select() failed");
371 		goto done;
372 	}
373 	PJDLOG_ASSERT(ret > 0);
374 	PJDLOG_ASSERT(FD_ISSET(tctx->tc_fd, &fdset));
375 	esize = sizeof(error);
376 	if (getsockopt(tctx->tc_fd, SOL_SOCKET, SO_ERROR, &error,
377 	    &esize) == -1) {
378 		error = errno;
379 		pjdlog_common(LOG_DEBUG, 1, errno,
380 		    "getsockopt(SO_ERROR) failed");
381 		goto done;
382 	}
383 	if (error != 0) {
384 		pjdlog_common(LOG_DEBUG, 1, error,
385 		    "getsockopt(SO_ERROR) returned error");
386 		goto done;
387 	}
388 	error = 0;
389 done:
390 	flags = fcntl(tctx->tc_fd, F_GETFL);
391 	if (flags == -1) {
392 		if (error == 0)
393 			error = errno;
394 		pjdlog_common(LOG_DEBUG, 1, errno, "fcntl(F_GETFL) failed");
395 		return (error);
396 	}
397 	flags &= ~O_NONBLOCK;
398 	if (fcntl(tctx->tc_fd, F_SETFL, flags) == -1) {
399 		if (error == 0)
400 			error = errno;
401 		pjdlog_common(LOG_DEBUG, 1, errno,
402 		    "fcntl(F_SETFL, ~O_NONBLOCK) failed");
403 	}
404 	return (error);
405 }
406 
407 static int
408 tcp_server(const char *addr, void **ctxp)
409 {
410 	struct tcp_ctx *tctx;
411 	int ret, val;
412 
413 	ret = tcp_setup_new(addr, TCP_SIDE_SERVER_LISTEN, ctxp);
414 	if (ret != 0)
415 		return (ret);
416 
417 	tctx = *ctxp;
418 
419 	val = 1;
420 	/* Ignore failure. */
421 	(void)setsockopt(tctx->tc_fd, SOL_SOCKET, SO_REUSEADDR, &val,
422 	   sizeof(val));
423 
424 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
425 
426 	if (bind(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
427 	    tctx->tc_sa.ss_len) < 0) {
428 		ret = errno;
429 		tcp_close(tctx);
430 		return (ret);
431 	}
432 	if (listen(tctx->tc_fd, 8) < 0) {
433 		ret = errno;
434 		tcp_close(tctx);
435 		return (ret);
436 	}
437 
438 	return (0);
439 }
440 
441 static int
442 tcp_accept(void *ctx, void **newctxp)
443 {
444 	struct tcp_ctx *tctx = ctx;
445 	struct tcp_ctx *newtctx;
446 	socklen_t fromlen;
447 	int ret;
448 
449 	PJDLOG_ASSERT(tctx != NULL);
450 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
451 	PJDLOG_ASSERT(tctx->tc_side == TCP_SIDE_SERVER_LISTEN);
452 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
453 	PJDLOG_ASSERT(tctx->tc_sa.ss_family != AF_UNSPEC);
454 
455 	newtctx = malloc(sizeof(*newtctx));
456 	if (newtctx == NULL)
457 		return (errno);
458 
459 	fromlen = tctx->tc_sa.ss_len;
460 	newtctx->tc_fd = accept(tctx->tc_fd, (struct sockaddr *)&tctx->tc_sa,
461 	    &fromlen);
462 	if (newtctx->tc_fd < 0) {
463 		ret = errno;
464 		free(newtctx);
465 		return (ret);
466 	}
467 
468 	newtctx->tc_side = TCP_SIDE_SERVER_WORK;
469 	newtctx->tc_magic = TCP_CTX_MAGIC;
470 	*newctxp = newtctx;
471 
472 	return (0);
473 }
474 
475 static int
476 tcp_wrap(int fd, bool client, void **ctxp)
477 {
478 
479 	return (tcp_setup_wrap(fd,
480 	    client ? TCP_SIDE_CLIENT : TCP_SIDE_SERVER_WORK, ctxp));
481 }
482 
483 static int
484 tcp_send(void *ctx, const unsigned char *data, size_t size, int fd)
485 {
486 	struct tcp_ctx *tctx = ctx;
487 
488 	PJDLOG_ASSERT(tctx != NULL);
489 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
490 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
491 	PJDLOG_ASSERT(fd == -1);
492 
493 	return (proto_common_send(tctx->tc_fd, data, size, -1));
494 }
495 
496 static int
497 tcp_recv(void *ctx, unsigned char *data, size_t size, int *fdp)
498 {
499 	struct tcp_ctx *tctx = ctx;
500 
501 	PJDLOG_ASSERT(tctx != NULL);
502 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
503 	PJDLOG_ASSERT(tctx->tc_fd >= 0);
504 	PJDLOG_ASSERT(fdp == NULL);
505 
506 	return (proto_common_recv(tctx->tc_fd, data, size, NULL));
507 }
508 
509 static int
510 tcp_descriptor(const void *ctx)
511 {
512 	const struct tcp_ctx *tctx = ctx;
513 
514 	PJDLOG_ASSERT(tctx != NULL);
515 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
516 
517 	return (tctx->tc_fd);
518 }
519 
520 static bool
521 tcp_address_match(const void *ctx, const char *addr)
522 {
523 	const struct tcp_ctx *tctx = ctx;
524 	struct sockaddr_storage sa1, sa2;
525 	socklen_t salen;
526 
527 	PJDLOG_ASSERT(tctx != NULL);
528 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
529 
530 	if (tcp_addr(addr, PROTO_TCP_DEFAULT_PORT, &sa1) != 0)
531 		return (false);
532 
533 	salen = sizeof(sa2);
534 	if (getpeername(tctx->tc_fd, (struct sockaddr *)&sa2, &salen) < 0)
535 		return (false);
536 
537 	if (sa1.ss_family != sa2.ss_family || sa1.ss_len != sa2.ss_len)
538 		return (false);
539 
540 	switch (sa1.ss_family) {
541 	case AF_INET:
542 	    {
543 		struct sockaddr_in *sin1, *sin2;
544 
545 		sin1 = (struct sockaddr_in *)&sa1;
546 		sin2 = (struct sockaddr_in *)&sa2;
547 
548 		return (memcmp(&sin1->sin_addr, &sin2->sin_addr,
549 		    sizeof(sin1->sin_addr)) == 0);
550 	    }
551 	case AF_INET6:
552 	    {
553 		struct sockaddr_in6 *sin1, *sin2;
554 
555 		sin1 = (struct sockaddr_in6 *)&sa1;
556 		sin2 = (struct sockaddr_in6 *)&sa2;
557 
558 		return (memcmp(&sin1->sin6_addr, &sin2->sin6_addr,
559 		    sizeof(sin1->sin6_addr)) == 0);
560 	    }
561 	default:
562 		return (false);
563 	}
564 }
565 
566 static void
567 tcp_local_address(const void *ctx, char *addr, size_t size)
568 {
569 	const struct tcp_ctx *tctx = ctx;
570 	struct sockaddr_storage sa;
571 	socklen_t salen;
572 
573 	PJDLOG_ASSERT(tctx != NULL);
574 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
575 
576 	salen = sizeof(sa);
577 	if (getsockname(tctx->tc_fd, (struct sockaddr *)&sa, &salen) < 0) {
578 		PJDLOG_VERIFY(strlcpy(addr, "N/A", size) < size);
579 		return;
580 	}
581 	PJDLOG_VERIFY(snprintf(addr, size, "tcp://%S", &sa) < (ssize_t)size);
582 }
583 
584 static void
585 tcp_remote_address(const void *ctx, char *addr, size_t size)
586 {
587 	const struct tcp_ctx *tctx = ctx;
588 	struct sockaddr_storage sa;
589 	socklen_t salen;
590 
591 	PJDLOG_ASSERT(tctx != NULL);
592 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
593 
594 	salen = sizeof(sa);
595 	if (getpeername(tctx->tc_fd, (struct sockaddr *)&sa, &salen) < 0) {
596 		PJDLOG_VERIFY(strlcpy(addr, "N/A", size) < size);
597 		return;
598 	}
599 	PJDLOG_VERIFY(snprintf(addr, size, "tcp://%S", &sa) < (ssize_t)size);
600 }
601 
602 static void
603 tcp_close(void *ctx)
604 {
605 	struct tcp_ctx *tctx = ctx;
606 
607 	PJDLOG_ASSERT(tctx != NULL);
608 	PJDLOG_ASSERT(tctx->tc_magic == TCP_CTX_MAGIC);
609 
610 	if (tctx->tc_fd >= 0)
611 		close(tctx->tc_fd);
612 	tctx->tc_magic = 0;
613 	free(tctx);
614 }
615 
616 static struct proto tcp_proto = {
617 	.prt_name = "tcp",
618 	.prt_client = tcp_client,
619 	.prt_connect = tcp_connect,
620 	.prt_connect_wait = tcp_connect_wait,
621 	.prt_server = tcp_server,
622 	.prt_accept = tcp_accept,
623 	.prt_wrap = tcp_wrap,
624 	.prt_send = tcp_send,
625 	.prt_recv = tcp_recv,
626 	.prt_descriptor = tcp_descriptor,
627 	.prt_address_match = tcp_address_match,
628 	.prt_local_address = tcp_local_address,
629 	.prt_remote_address = tcp_remote_address,
630 	.prt_close = tcp_close
631 };
632 
633 static __constructor void
634 tcp_ctor(void)
635 {
636 
637 	proto_register(&tcp_proto, true);
638 }
639