1 // SPDX-License-Identifier: GPL-2.0
2 
3 #define _GNU_SOURCE
4 
5 #include <errno.h>
6 #include <limits.h>
7 #include <fcntl.h>
8 #include <string.h>
9 #include <stdarg.h>
10 #include <stdbool.h>
11 #include <stdint.h>
12 #include <stdio.h>
13 #include <stdlib.h>
14 #include <strings.h>
15 #include <signal.h>
16 #include <unistd.h>
17 #include <time.h>
18 
19 #include <sys/ioctl.h>
20 #include <sys/poll.h>
21 #include <sys/sendfile.h>
22 #include <sys/stat.h>
23 #include <sys/socket.h>
24 #include <sys/types.h>
25 #include <sys/mman.h>
26 
27 #include <netdb.h>
28 #include <netinet/in.h>
29 
30 #include <linux/tcp.h>
31 #include <linux/time_types.h>
32 #include <linux/sockios.h>
33 
34 extern int optind;
35 
36 #ifndef IPPROTO_MPTCP
37 #define IPPROTO_MPTCP 262
38 #endif
39 #ifndef TCP_ULP
40 #define TCP_ULP 31
41 #endif
42 
43 static int  poll_timeout = 10 * 1000;
44 static bool listen_mode;
45 static bool quit;
46 
47 enum cfg_mode {
48 	CFG_MODE_POLL,
49 	CFG_MODE_MMAP,
50 	CFG_MODE_SENDFILE,
51 };
52 
53 enum cfg_peek {
54 	CFG_NONE_PEEK,
55 	CFG_WITH_PEEK,
56 	CFG_AFTER_PEEK,
57 };
58 
59 static enum cfg_mode cfg_mode = CFG_MODE_POLL;
60 static enum cfg_peek cfg_peek = CFG_NONE_PEEK;
61 static const char *cfg_host;
62 static const char *cfg_port	= "12000";
63 static int cfg_sock_proto	= IPPROTO_MPTCP;
64 static int pf = AF_INET;
65 static int cfg_sndbuf;
66 static int cfg_rcvbuf;
67 static bool cfg_join;
68 static bool cfg_remove;
69 static unsigned int cfg_time;
70 static unsigned int cfg_do_w;
71 static int cfg_wait;
72 static uint32_t cfg_mark;
73 static char *cfg_input;
74 static int cfg_repeat = 1;
75 static int cfg_truncate;
76 static int cfg_rcv_trunc;
77 
78 struct cfg_cmsg_types {
79 	unsigned int cmsg_enabled:1;
80 	unsigned int timestampns:1;
81 	unsigned int tcp_inq:1;
82 };
83 
84 struct cfg_sockopt_types {
85 	unsigned int transparent:1;
86 	unsigned int mptfo:1;
87 };
88 
89 struct tcp_inq_state {
90 	unsigned int last;
91 	bool expect_eof;
92 };
93 
94 struct wstate {
95 	char buf[8192];
96 	unsigned int len;
97 	unsigned int off;
98 	unsigned int total_len;
99 };
100 
101 static struct tcp_inq_state tcp_inq;
102 
103 static struct cfg_cmsg_types cfg_cmsg_types;
104 static struct cfg_sockopt_types cfg_sockopt_types;
105 
106 static void die_usage(void)
107 {
108 	fprintf(stderr, "Usage: mptcp_connect [-6] [-c cmsg] [-f offset] [-i file] [-I num] [-j] [-l] "
109 		"[-m mode] [-M mark] [-o option] [-p port] [-P mode] [-j] [-l] [-r num] "
110 		"[-s MPTCP|TCP] [-S num] [-r num] [-t num] [-T num] [-u] [-w sec] connect_address\n");
111 	fprintf(stderr, "\t-6 use ipv6\n");
112 	fprintf(stderr, "\t-c cmsg -- test cmsg type <cmsg>\n");
113 	fprintf(stderr, "\t-f offset -- stop the I/O after receiving and sending the specified amount "
114 		"of bytes. If there are unread bytes in the receive queue, that will cause a MPTCP "
115 		"fastclose at close/shutdown. If offset is negative, expect the peer to close before "
116 		"all the local data as been sent, thus toleration errors on write and EPIPE signals\n");
117 	fprintf(stderr, "\t-i file -- read the data to send from the given file instead of stdin");
118 	fprintf(stderr, "\t-I num -- repeat the transfer 'num' times. In listen mode accepts num "
119 		"incoming connections, in client mode, disconnect and reconnect to the server\n");
120 	fprintf(stderr, "\t-j     -- add additional sleep at connection start and tear down "
121 		"-- for MPJ tests\n");
122 	fprintf(stderr, "\t-l     -- listens mode, accepts incoming connection\n");
123 	fprintf(stderr, "\t-m [poll|mmap|sendfile] -- use poll(default)/mmap+write/sendfile\n");
124 	fprintf(stderr, "\t-M mark -- set socket packet mark\n");
125 	fprintf(stderr, "\t-o option -- test sockopt <option>\n");
126 	fprintf(stderr, "\t-p num -- use port num\n");
127 	fprintf(stderr,
128 		"\t-P [saveWithPeek|saveAfterPeek] -- save data with/after MSG_PEEK form tcp socket\n");
129 	fprintf(stderr, "\t-t num -- set poll timeout to num\n");
130 	fprintf(stderr, "\t-T num -- set expected runtime to num ms\n");
131 	fprintf(stderr, "\t-r num -- enable slow mode, limiting each write to num bytes "
132 		"-- for remove addr tests\n");
133 	fprintf(stderr, "\t-R num -- set SO_RCVBUF to num\n");
134 	fprintf(stderr, "\t-s [MPTCP|TCP] -- use mptcp(default) or tcp sockets\n");
135 	fprintf(stderr, "\t-S num -- set SO_SNDBUF to num\n");
136 	fprintf(stderr, "\t-w num -- wait num sec before closing the socket\n");
137 	exit(1);
138 }
139 
140 static void xerror(const char *fmt, ...)
141 {
142 	va_list ap;
143 
144 	va_start(ap, fmt);
145 	vfprintf(stderr, fmt, ap);
146 	va_end(ap);
147 	exit(1);
148 }
149 
150 static void handle_signal(int nr)
151 {
152 	quit = true;
153 }
154 
155 static const char *getxinfo_strerr(int err)
156 {
157 	if (err == EAI_SYSTEM)
158 		return strerror(errno);
159 
160 	return gai_strerror(err);
161 }
162 
163 static void xgetnameinfo(const struct sockaddr *addr, socklen_t addrlen,
164 			 char *host, socklen_t hostlen,
165 			 char *serv, socklen_t servlen)
166 {
167 	int flags = NI_NUMERICHOST | NI_NUMERICSERV;
168 	int err = getnameinfo(addr, addrlen, host, hostlen, serv, servlen,
169 			      flags);
170 
171 	if (err) {
172 		const char *errstr = getxinfo_strerr(err);
173 
174 		fprintf(stderr, "Fatal: getnameinfo: %s\n", errstr);
175 		exit(1);
176 	}
177 }
178 
179 static void xgetaddrinfo(const char *node, const char *service,
180 			 const struct addrinfo *hints,
181 			 struct addrinfo **res)
182 {
183 	int err = getaddrinfo(node, service, hints, res);
184 
185 	if (err) {
186 		const char *errstr = getxinfo_strerr(err);
187 
188 		fprintf(stderr, "Fatal: getaddrinfo(%s:%s): %s\n",
189 			node ? node : "", service ? service : "", errstr);
190 		exit(1);
191 	}
192 }
193 
194 static void set_rcvbuf(int fd, unsigned int size)
195 {
196 	int err;
197 
198 	err = setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &size, sizeof(size));
199 	if (err) {
200 		perror("set SO_RCVBUF");
201 		exit(1);
202 	}
203 }
204 
205 static void set_sndbuf(int fd, unsigned int size)
206 {
207 	int err;
208 
209 	err = setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size));
210 	if (err) {
211 		perror("set SO_SNDBUF");
212 		exit(1);
213 	}
214 }
215 
216 static void set_mark(int fd, uint32_t mark)
217 {
218 	int err;
219 
220 	err = setsockopt(fd, SOL_SOCKET, SO_MARK, &mark, sizeof(mark));
221 	if (err) {
222 		perror("set SO_MARK");
223 		exit(1);
224 	}
225 }
226 
227 static void set_transparent(int fd, int pf)
228 {
229 	int one = 1;
230 
231 	switch (pf) {
232 	case AF_INET:
233 		if (-1 == setsockopt(fd, SOL_IP, IP_TRANSPARENT, &one, sizeof(one)))
234 			perror("IP_TRANSPARENT");
235 		break;
236 	case AF_INET6:
237 		if (-1 == setsockopt(fd, IPPROTO_IPV6, IPV6_TRANSPARENT, &one, sizeof(one)))
238 			perror("IPV6_TRANSPARENT");
239 		break;
240 	}
241 }
242 
243 static void set_mptfo(int fd, int pf)
244 {
245 	int qlen = 25;
246 
247 	if (setsockopt(fd, IPPROTO_TCP, TCP_FASTOPEN, &qlen, sizeof(qlen)) == -1)
248 		perror("TCP_FASTOPEN");
249 }
250 
251 static int do_ulp_so(int sock, const char *name)
252 {
253 	return setsockopt(sock, IPPROTO_TCP, TCP_ULP, name, strlen(name));
254 }
255 
256 #define X(m)	xerror("%s:%u: %s: failed for proto %d at line %u", __FILE__, __LINE__, (m), proto, line)
257 static void sock_test_tcpulp(int sock, int proto, unsigned int line)
258 {
259 	socklen_t buflen = 8;
260 	char buf[8] = "";
261 	int ret = getsockopt(sock, IPPROTO_TCP, TCP_ULP, buf, &buflen);
262 
263 	if (ret != 0)
264 		X("getsockopt");
265 
266 	if (buflen > 0) {
267 		if (strcmp(buf, "mptcp") != 0)
268 			xerror("unexpected ULP '%s' for proto %d at line %u", buf, proto, line);
269 		ret = do_ulp_so(sock, "tls");
270 		if (ret == 0)
271 			X("setsockopt");
272 	} else if (proto == IPPROTO_MPTCP) {
273 		ret = do_ulp_so(sock, "tls");
274 		if (ret != -1)
275 			X("setsockopt");
276 	}
277 
278 	ret = do_ulp_so(sock, "mptcp");
279 	if (ret != -1)
280 		X("setsockopt");
281 
282 #undef X
283 }
284 
285 #define SOCK_TEST_TCPULP(s, p) sock_test_tcpulp((s), (p), __LINE__)
286 
287 static int sock_listen_mptcp(const char * const listenaddr,
288 			     const char * const port)
289 {
290 	int sock = -1;
291 	struct addrinfo hints = {
292 		.ai_protocol = IPPROTO_TCP,
293 		.ai_socktype = SOCK_STREAM,
294 		.ai_flags = AI_PASSIVE | AI_NUMERICHOST
295 	};
296 
297 	hints.ai_family = pf;
298 
299 	struct addrinfo *a, *addr;
300 	int one = 1;
301 
302 	xgetaddrinfo(listenaddr, port, &hints, &addr);
303 	hints.ai_family = pf;
304 
305 	for (a = addr; a; a = a->ai_next) {
306 		sock = socket(a->ai_family, a->ai_socktype, cfg_sock_proto);
307 		if (sock < 0)
308 			continue;
309 
310 		SOCK_TEST_TCPULP(sock, cfg_sock_proto);
311 
312 		if (-1 == setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &one,
313 				     sizeof(one)))
314 			perror("setsockopt");
315 
316 		if (cfg_sockopt_types.transparent)
317 			set_transparent(sock, pf);
318 
319 		if (cfg_sockopt_types.mptfo)
320 			set_mptfo(sock, pf);
321 
322 		if (bind(sock, a->ai_addr, a->ai_addrlen) == 0)
323 			break; /* success */
324 
325 		perror("bind");
326 		close(sock);
327 		sock = -1;
328 	}
329 
330 	freeaddrinfo(addr);
331 
332 	if (sock < 0) {
333 		fprintf(stderr, "Could not create listen socket\n");
334 		return sock;
335 	}
336 
337 	SOCK_TEST_TCPULP(sock, cfg_sock_proto);
338 
339 	if (listen(sock, 20)) {
340 		perror("listen");
341 		close(sock);
342 		return -1;
343 	}
344 
345 	SOCK_TEST_TCPULP(sock, cfg_sock_proto);
346 
347 	return sock;
348 }
349 
350 static int sock_connect_mptcp(const char * const remoteaddr,
351 			      const char * const port, int proto,
352 			      struct addrinfo **peer,
353 			      int infd, struct wstate *winfo)
354 {
355 	struct addrinfo hints = {
356 		.ai_protocol = IPPROTO_TCP,
357 		.ai_socktype = SOCK_STREAM,
358 	};
359 	struct addrinfo *a, *addr;
360 	int syn_copied = 0;
361 	int sock = -1;
362 
363 	hints.ai_family = pf;
364 
365 	xgetaddrinfo(remoteaddr, port, &hints, &addr);
366 	for (a = addr; a; a = a->ai_next) {
367 		sock = socket(a->ai_family, a->ai_socktype, proto);
368 		if (sock < 0) {
369 			perror("socket");
370 			continue;
371 		}
372 
373 		SOCK_TEST_TCPULP(sock, proto);
374 
375 		if (cfg_mark)
376 			set_mark(sock, cfg_mark);
377 
378 		if (cfg_sockopt_types.mptfo) {
379 			if (!winfo->total_len)
380 				winfo->total_len = winfo->len = read(infd, winfo->buf,
381 								     sizeof(winfo->buf));
382 
383 			syn_copied = sendto(sock, winfo->buf, winfo->len, MSG_FASTOPEN,
384 					    a->ai_addr, a->ai_addrlen);
385 			if (syn_copied >= 0) {
386 				winfo->off = syn_copied;
387 				winfo->len -= syn_copied;
388 				*peer = a;
389 				break; /* success */
390 			}
391 		} else {
392 			if (connect(sock, a->ai_addr, a->ai_addrlen) == 0) {
393 				*peer = a;
394 				break; /* success */
395 			}
396 		}
397 		if (cfg_sockopt_types.mptfo) {
398 			perror("sendto()");
399 			close(sock);
400 			sock = -1;
401 		} else {
402 			perror("connect()");
403 			close(sock);
404 			sock = -1;
405 		}
406 	}
407 
408 	freeaddrinfo(addr);
409 	if (sock != -1)
410 		SOCK_TEST_TCPULP(sock, proto);
411 	return sock;
412 }
413 
414 static size_t do_rnd_write(const int fd, char *buf, const size_t len)
415 {
416 	static bool first = true;
417 	unsigned int do_w;
418 	ssize_t bw;
419 
420 	do_w = rand() & 0xffff;
421 	if (do_w == 0 || do_w > len)
422 		do_w = len;
423 
424 	if (cfg_join && first && do_w > 100)
425 		do_w = 100;
426 
427 	if (cfg_remove && do_w > cfg_do_w)
428 		do_w = cfg_do_w;
429 
430 	bw = write(fd, buf, do_w);
431 	if (bw < 0)
432 		return bw;
433 
434 	/* let the join handshake complete, before going on */
435 	if (cfg_join && first) {
436 		usleep(200000);
437 		first = false;
438 	}
439 
440 	if (cfg_remove)
441 		usleep(200000);
442 
443 	return bw;
444 }
445 
446 static size_t do_write(const int fd, char *buf, const size_t len)
447 {
448 	size_t offset = 0;
449 
450 	while (offset < len) {
451 		size_t written;
452 		ssize_t bw;
453 
454 		bw = write(fd, buf + offset, len - offset);
455 		if (bw < 0) {
456 			perror("write");
457 			return 0;
458 		}
459 
460 		written = (size_t)bw;
461 		offset += written;
462 	}
463 
464 	return offset;
465 }
466 
467 static void process_cmsg(struct msghdr *msgh)
468 {
469 	struct __kernel_timespec ts;
470 	bool inq_found = false;
471 	bool ts_found = false;
472 	unsigned int inq = 0;
473 	struct cmsghdr *cmsg;
474 
475 	for (cmsg = CMSG_FIRSTHDR(msgh); cmsg ; cmsg = CMSG_NXTHDR(msgh, cmsg)) {
476 		if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SO_TIMESTAMPNS_NEW) {
477 			memcpy(&ts, CMSG_DATA(cmsg), sizeof(ts));
478 			ts_found = true;
479 			continue;
480 		}
481 		if (cmsg->cmsg_level == IPPROTO_TCP && cmsg->cmsg_type == TCP_CM_INQ) {
482 			memcpy(&inq, CMSG_DATA(cmsg), sizeof(inq));
483 			inq_found = true;
484 			continue;
485 		}
486 
487 	}
488 
489 	if (cfg_cmsg_types.timestampns) {
490 		if (!ts_found)
491 			xerror("TIMESTAMPNS not present\n");
492 	}
493 
494 	if (cfg_cmsg_types.tcp_inq) {
495 		if (!inq_found)
496 			xerror("TCP_INQ not present\n");
497 
498 		if (inq > 1024)
499 			xerror("tcp_inq %u is larger than one kbyte\n", inq);
500 		tcp_inq.last = inq;
501 	}
502 }
503 
504 static ssize_t do_recvmsg_cmsg(const int fd, char *buf, const size_t len)
505 {
506 	char msg_buf[8192];
507 	struct iovec iov = {
508 		.iov_base = buf,
509 		.iov_len = len,
510 	};
511 	struct msghdr msg = {
512 		.msg_iov = &iov,
513 		.msg_iovlen = 1,
514 		.msg_control = msg_buf,
515 		.msg_controllen = sizeof(msg_buf),
516 	};
517 	int flags = 0;
518 	unsigned int last_hint = tcp_inq.last;
519 	int ret = recvmsg(fd, &msg, flags);
520 
521 	if (ret <= 0) {
522 		if (ret == 0 && tcp_inq.expect_eof)
523 			return ret;
524 
525 		if (ret == 0 && cfg_cmsg_types.tcp_inq)
526 			if (last_hint != 1 && last_hint != 0)
527 				xerror("EOF but last tcp_inq hint was %u\n", last_hint);
528 
529 		return ret;
530 	}
531 
532 	if (tcp_inq.expect_eof)
533 		xerror("expected EOF, last_hint %u, now %u\n",
534 		       last_hint, tcp_inq.last);
535 
536 	if (msg.msg_controllen && !cfg_cmsg_types.cmsg_enabled)
537 		xerror("got %lu bytes of cmsg data, expected 0\n",
538 		       (unsigned long)msg.msg_controllen);
539 
540 	if (msg.msg_controllen == 0 && cfg_cmsg_types.cmsg_enabled)
541 		xerror("%s\n", "got no cmsg data");
542 
543 	if (msg.msg_controllen)
544 		process_cmsg(&msg);
545 
546 	if (cfg_cmsg_types.tcp_inq) {
547 		if ((size_t)ret < len && last_hint > (unsigned int)ret) {
548 			if (ret + 1 != (int)last_hint) {
549 				int next = read(fd, msg_buf, sizeof(msg_buf));
550 
551 				xerror("read %u of %u, last_hint was %u tcp_inq hint now %u next_read returned %d/%m\n",
552 				       ret, (unsigned int)len, last_hint, tcp_inq.last, next);
553 			} else {
554 				tcp_inq.expect_eof = true;
555 			}
556 		}
557 	}
558 
559 	return ret;
560 }
561 
562 static ssize_t do_rnd_read(const int fd, char *buf, const size_t len)
563 {
564 	int ret = 0;
565 	char tmp[16384];
566 	size_t cap = rand();
567 
568 	cap &= 0xffff;
569 
570 	if (cap == 0)
571 		cap = 1;
572 	else if (cap > len)
573 		cap = len;
574 
575 	if (cfg_peek == CFG_WITH_PEEK) {
576 		ret = recv(fd, buf, cap, MSG_PEEK);
577 		ret = (ret < 0) ? ret : read(fd, tmp, ret);
578 	} else if (cfg_peek == CFG_AFTER_PEEK) {
579 		ret = recv(fd, buf, cap, MSG_PEEK);
580 		ret = (ret < 0) ? ret : read(fd, buf, cap);
581 	} else if (cfg_cmsg_types.cmsg_enabled) {
582 		ret = do_recvmsg_cmsg(fd, buf, cap);
583 	} else {
584 		ret = read(fd, buf, cap);
585 	}
586 
587 	return ret;
588 }
589 
590 static void set_nonblock(int fd, bool nonblock)
591 {
592 	int flags = fcntl(fd, F_GETFL);
593 
594 	if (flags == -1)
595 		return;
596 
597 	if (nonblock)
598 		fcntl(fd, F_SETFL, flags | O_NONBLOCK);
599 	else
600 		fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
601 }
602 
603 static void shut_wr(int fd)
604 {
605 	/* Close our write side, ev. give some time
606 	 * for address notification and/or checking
607 	 * the current status
608 	 */
609 	if (cfg_wait)
610 		usleep(cfg_wait);
611 
612 	shutdown(fd, SHUT_WR);
613 }
614 
615 static int copyfd_io_poll(int infd, int peerfd, int outfd,
616 			  bool *in_closed_after_out, struct wstate *winfo)
617 {
618 	struct pollfd fds = {
619 		.fd = peerfd,
620 		.events = POLLIN | POLLOUT,
621 	};
622 	unsigned int total_wlen = 0, total_rlen = 0;
623 
624 	set_nonblock(peerfd, true);
625 
626 	for (;;) {
627 		char rbuf[8192];
628 		ssize_t len;
629 
630 		if (fds.events == 0)
631 			break;
632 
633 		switch (poll(&fds, 1, poll_timeout)) {
634 		case -1:
635 			if (errno == EINTR)
636 				continue;
637 			perror("poll");
638 			return 1;
639 		case 0:
640 			fprintf(stderr, "%s: poll timed out (events: "
641 				"POLLIN %u, POLLOUT %u)\n", __func__,
642 				fds.events & POLLIN, fds.events & POLLOUT);
643 			return 2;
644 		}
645 
646 		if (fds.revents & POLLIN) {
647 			ssize_t rb = sizeof(rbuf);
648 
649 			/* limit the total amount of read data to the trunc value*/
650 			if (cfg_truncate > 0) {
651 				if (rb + total_rlen > cfg_truncate)
652 					rb = cfg_truncate - total_rlen;
653 				len = read(peerfd, rbuf, rb);
654 			} else {
655 				len = do_rnd_read(peerfd, rbuf, sizeof(rbuf));
656 			}
657 			if (len == 0) {
658 				/* no more data to receive:
659 				 * peer has closed its write side
660 				 */
661 				fds.events &= ~POLLIN;
662 
663 				if ((fds.events & POLLOUT) == 0) {
664 					*in_closed_after_out = true;
665 					/* and nothing more to send */
666 					break;
667 				}
668 
669 			/* Else, still have data to transmit */
670 			} else if (len < 0) {
671 				if (cfg_rcv_trunc)
672 					return 0;
673 				perror("read");
674 				return 3;
675 			}
676 
677 			total_rlen += len;
678 			do_write(outfd, rbuf, len);
679 		}
680 
681 		if (fds.revents & POLLOUT) {
682 			if (winfo->len == 0) {
683 				winfo->off = 0;
684 				winfo->len = read(infd, winfo->buf, sizeof(winfo->buf));
685 			}
686 
687 			if (winfo->len > 0) {
688 				ssize_t bw;
689 
690 				/* limit the total amount of written data to the trunc value */
691 				if (cfg_truncate > 0 && winfo->len + total_wlen > cfg_truncate)
692 					winfo->len = cfg_truncate - total_wlen;
693 
694 				bw = do_rnd_write(peerfd, winfo->buf + winfo->off, winfo->len);
695 				if (bw < 0) {
696 					if (cfg_rcv_trunc)
697 						return 0;
698 					perror("write");
699 					return 111;
700 				}
701 
702 				winfo->off += bw;
703 				winfo->len -= bw;
704 				total_wlen += bw;
705 			} else if (winfo->len == 0) {
706 				/* We have no more data to send. */
707 				fds.events &= ~POLLOUT;
708 
709 				if ((fds.events & POLLIN) == 0)
710 					/* ... and peer also closed already */
711 					break;
712 
713 				shut_wr(peerfd);
714 			} else {
715 				if (errno == EINTR)
716 					continue;
717 				perror("read");
718 				return 4;
719 			}
720 		}
721 
722 		if (fds.revents & (POLLERR | POLLNVAL)) {
723 			if (cfg_rcv_trunc)
724 				return 0;
725 			fprintf(stderr, "Unexpected revents: "
726 				"POLLERR/POLLNVAL(%x)\n", fds.revents);
727 			return 5;
728 		}
729 
730 		if (cfg_truncate > 0 && total_wlen >= cfg_truncate &&
731 		    total_rlen >= cfg_truncate)
732 			break;
733 	}
734 
735 	/* leave some time for late join/announce */
736 	if (cfg_remove)
737 		usleep(cfg_wait);
738 
739 	return 0;
740 }
741 
742 static int do_recvfile(int infd, int outfd)
743 {
744 	ssize_t r;
745 
746 	do {
747 		char buf[16384];
748 
749 		r = do_rnd_read(infd, buf, sizeof(buf));
750 		if (r > 0) {
751 			if (write(outfd, buf, r) != r)
752 				break;
753 		} else if (r < 0) {
754 			perror("read");
755 		}
756 	} while (r > 0);
757 
758 	return (int)r;
759 }
760 
761 static int spool_buf(int fd, struct wstate *winfo)
762 {
763 	while (winfo->len) {
764 		int ret = write(fd, winfo->buf + winfo->off, winfo->len);
765 
766 		if (ret < 0) {
767 			perror("write");
768 			return 4;
769 		}
770 		winfo->off += ret;
771 		winfo->len -= ret;
772 	}
773 	return 0;
774 }
775 
776 static int do_mmap(int infd, int outfd, unsigned int size,
777 		   struct wstate *winfo)
778 {
779 	char *inbuf = mmap(NULL, size, PROT_READ, MAP_SHARED, infd, 0);
780 	ssize_t ret = 0, off = winfo->total_len;
781 	size_t rem;
782 
783 	if (inbuf == MAP_FAILED) {
784 		perror("mmap");
785 		return 1;
786 	}
787 
788 	ret = spool_buf(outfd, winfo);
789 	if (ret < 0)
790 		return ret;
791 
792 	rem = size - winfo->total_len;
793 
794 	while (rem > 0) {
795 		ret = write(outfd, inbuf + off, rem);
796 
797 		if (ret < 0) {
798 			perror("write");
799 			break;
800 		}
801 
802 		off += ret;
803 		rem -= ret;
804 	}
805 
806 	munmap(inbuf, size);
807 	return rem;
808 }
809 
810 static int get_infd_size(int fd)
811 {
812 	struct stat sb;
813 	ssize_t count;
814 	int err;
815 
816 	err = fstat(fd, &sb);
817 	if (err < 0) {
818 		perror("fstat");
819 		return -1;
820 	}
821 
822 	if ((sb.st_mode & S_IFMT) != S_IFREG) {
823 		fprintf(stderr, "%s: stdin is not a regular file\n", __func__);
824 		return -2;
825 	}
826 
827 	count = sb.st_size;
828 	if (count > INT_MAX) {
829 		fprintf(stderr, "File too large: %zu\n", count);
830 		return -3;
831 	}
832 
833 	return (int)count;
834 }
835 
836 static int do_sendfile(int infd, int outfd, unsigned int count,
837 		       struct wstate *winfo)
838 {
839 	int ret = spool_buf(outfd, winfo);
840 
841 	if (ret < 0)
842 		return ret;
843 
844 	count -= winfo->total_len;
845 
846 	while (count > 0) {
847 		ssize_t r;
848 
849 		r = sendfile(outfd, infd, NULL, count);
850 		if (r < 0) {
851 			perror("sendfile");
852 			return 3;
853 		}
854 
855 		count -= r;
856 	}
857 
858 	return 0;
859 }
860 
861 static int copyfd_io_mmap(int infd, int peerfd, int outfd,
862 			  unsigned int size, bool *in_closed_after_out,
863 			  struct wstate *winfo)
864 {
865 	int err;
866 
867 	if (listen_mode) {
868 		err = do_recvfile(peerfd, outfd);
869 		if (err)
870 			return err;
871 
872 		err = do_mmap(infd, peerfd, size, winfo);
873 	} else {
874 		err = do_mmap(infd, peerfd, size, winfo);
875 		if (err)
876 			return err;
877 
878 		shut_wr(peerfd);
879 
880 		err = do_recvfile(peerfd, outfd);
881 		*in_closed_after_out = true;
882 	}
883 
884 	return err;
885 }
886 
887 static int copyfd_io_sendfile(int infd, int peerfd, int outfd,
888 			      unsigned int size, bool *in_closed_after_out, struct wstate *winfo)
889 {
890 	int err;
891 
892 	if (listen_mode) {
893 		err = do_recvfile(peerfd, outfd);
894 		if (err)
895 			return err;
896 
897 		err = do_sendfile(infd, peerfd, size, winfo);
898 	} else {
899 		err = do_sendfile(infd, peerfd, size, winfo);
900 		if (err)
901 			return err;
902 
903 		shut_wr(peerfd);
904 
905 		err = do_recvfile(peerfd, outfd);
906 		*in_closed_after_out = true;
907 	}
908 
909 	return err;
910 }
911 
912 static int copyfd_io(int infd, int peerfd, int outfd, bool close_peerfd, struct wstate *winfo)
913 {
914 	bool in_closed_after_out = false;
915 	struct timespec start, end;
916 	int file_size;
917 	int ret;
918 
919 	if (cfg_time && (clock_gettime(CLOCK_MONOTONIC, &start) < 0))
920 		xerror("can not fetch start time %d", errno);
921 
922 	switch (cfg_mode) {
923 	case CFG_MODE_POLL:
924 		ret = copyfd_io_poll(infd, peerfd, outfd, &in_closed_after_out,
925 				     winfo);
926 		break;
927 
928 	case CFG_MODE_MMAP:
929 		file_size = get_infd_size(infd);
930 		if (file_size < 0)
931 			return file_size;
932 		ret = copyfd_io_mmap(infd, peerfd, outfd, file_size,
933 				     &in_closed_after_out, winfo);
934 		break;
935 
936 	case CFG_MODE_SENDFILE:
937 		file_size = get_infd_size(infd);
938 		if (file_size < 0)
939 			return file_size;
940 		ret = copyfd_io_sendfile(infd, peerfd, outfd, file_size,
941 					 &in_closed_after_out, winfo);
942 		break;
943 
944 	default:
945 		fprintf(stderr, "Invalid mode %d\n", cfg_mode);
946 
947 		die_usage();
948 		return 1;
949 	}
950 
951 	if (ret)
952 		return ret;
953 
954 	if (close_peerfd)
955 		close(peerfd);
956 
957 	if (cfg_time) {
958 		unsigned int delta_ms;
959 
960 		if (clock_gettime(CLOCK_MONOTONIC, &end) < 0)
961 			xerror("can not fetch end time %d", errno);
962 		delta_ms = (end.tv_sec - start.tv_sec) * 1000 + (end.tv_nsec - start.tv_nsec) / 1000000;
963 		if (delta_ms > cfg_time) {
964 			xerror("transfer slower than expected! runtime %d ms, expected %d ms",
965 			       delta_ms, cfg_time);
966 		}
967 
968 		/* show the runtime only if this end shutdown(wr) before receiving the EOF,
969 		 * (that is, if this end got the longer runtime)
970 		 */
971 		if (in_closed_after_out)
972 			fprintf(stderr, "%d", delta_ms);
973 	}
974 
975 	return 0;
976 }
977 
978 static void check_sockaddr(int pf, struct sockaddr_storage *ss,
979 			   socklen_t salen)
980 {
981 	struct sockaddr_in6 *sin6;
982 	struct sockaddr_in *sin;
983 	socklen_t wanted_size = 0;
984 
985 	switch (pf) {
986 	case AF_INET:
987 		wanted_size = sizeof(*sin);
988 		sin = (void *)ss;
989 		if (!sin->sin_port)
990 			fprintf(stderr, "accept: something wrong: ip connection from port 0");
991 		break;
992 	case AF_INET6:
993 		wanted_size = sizeof(*sin6);
994 		sin6 = (void *)ss;
995 		if (!sin6->sin6_port)
996 			fprintf(stderr, "accept: something wrong: ipv6 connection from port 0");
997 		break;
998 	default:
999 		fprintf(stderr, "accept: Unknown pf %d, salen %u\n", pf, salen);
1000 		return;
1001 	}
1002 
1003 	if (salen != wanted_size)
1004 		fprintf(stderr, "accept: size mismatch, got %d expected %d\n",
1005 			(int)salen, wanted_size);
1006 
1007 	if (ss->ss_family != pf)
1008 		fprintf(stderr, "accept: pf mismatch, expect %d, ss_family is %d\n",
1009 			(int)ss->ss_family, pf);
1010 }
1011 
1012 static void check_getpeername(int fd, struct sockaddr_storage *ss, socklen_t salen)
1013 {
1014 	struct sockaddr_storage peerss;
1015 	socklen_t peersalen = sizeof(peerss);
1016 
1017 	if (getpeername(fd, (struct sockaddr *)&peerss, &peersalen) < 0) {
1018 		perror("getpeername");
1019 		return;
1020 	}
1021 
1022 	if (peersalen != salen) {
1023 		fprintf(stderr, "%s: %d vs %d\n", __func__, peersalen, salen);
1024 		return;
1025 	}
1026 
1027 	if (memcmp(ss, &peerss, peersalen)) {
1028 		char a[INET6_ADDRSTRLEN];
1029 		char b[INET6_ADDRSTRLEN];
1030 		char c[INET6_ADDRSTRLEN];
1031 		char d[INET6_ADDRSTRLEN];
1032 
1033 		xgetnameinfo((struct sockaddr *)ss, salen,
1034 			     a, sizeof(a), b, sizeof(b));
1035 
1036 		xgetnameinfo((struct sockaddr *)&peerss, peersalen,
1037 			     c, sizeof(c), d, sizeof(d));
1038 
1039 		fprintf(stderr, "%s: memcmp failure: accept %s vs peername %s, %s vs %s salen %d vs %d\n",
1040 			__func__, a, c, b, d, peersalen, salen);
1041 	}
1042 }
1043 
1044 static void check_getpeername_connect(int fd)
1045 {
1046 	struct sockaddr_storage ss;
1047 	socklen_t salen = sizeof(ss);
1048 	char a[INET6_ADDRSTRLEN];
1049 	char b[INET6_ADDRSTRLEN];
1050 
1051 	if (getpeername(fd, (struct sockaddr *)&ss, &salen) < 0) {
1052 		perror("getpeername");
1053 		return;
1054 	}
1055 
1056 	xgetnameinfo((struct sockaddr *)&ss, salen,
1057 		     a, sizeof(a), b, sizeof(b));
1058 
1059 	if (strcmp(cfg_host, a) || strcmp(cfg_port, b))
1060 		fprintf(stderr, "%s: %s vs %s, %s vs %s\n", __func__,
1061 			cfg_host, a, cfg_port, b);
1062 }
1063 
1064 static void maybe_close(int fd)
1065 {
1066 	unsigned int r = rand();
1067 
1068 	if (!(cfg_join || cfg_remove || cfg_repeat > 1) && (r & 1))
1069 		close(fd);
1070 }
1071 
1072 int main_loop_s(int listensock)
1073 {
1074 	struct sockaddr_storage ss;
1075 	struct wstate winfo;
1076 	struct pollfd polls;
1077 	socklen_t salen;
1078 	int remotesock;
1079 	int fd = 0;
1080 
1081 again:
1082 	polls.fd = listensock;
1083 	polls.events = POLLIN;
1084 
1085 	switch (poll(&polls, 1, poll_timeout)) {
1086 	case -1:
1087 		perror("poll");
1088 		return 1;
1089 	case 0:
1090 		fprintf(stderr, "%s: timed out\n", __func__);
1091 		close(listensock);
1092 		return 2;
1093 	}
1094 
1095 	salen = sizeof(ss);
1096 	remotesock = accept(listensock, (struct sockaddr *)&ss, &salen);
1097 	if (remotesock >= 0) {
1098 		maybe_close(listensock);
1099 		check_sockaddr(pf, &ss, salen);
1100 		check_getpeername(remotesock, &ss, salen);
1101 
1102 		if (cfg_input) {
1103 			fd = open(cfg_input, O_RDONLY);
1104 			if (fd < 0)
1105 				xerror("can't open %s: %d", cfg_input, errno);
1106 		}
1107 
1108 		SOCK_TEST_TCPULP(remotesock, 0);
1109 
1110 		memset(&winfo, 0, sizeof(winfo));
1111 		copyfd_io(fd, remotesock, 1, true, &winfo);
1112 	} else {
1113 		perror("accept");
1114 		return 1;
1115 	}
1116 
1117 	if (--cfg_repeat > 0) {
1118 		if (cfg_input)
1119 			close(fd);
1120 		goto again;
1121 	}
1122 
1123 	return 0;
1124 }
1125 
1126 static void init_rng(void)
1127 {
1128 	int fd = open("/dev/urandom", O_RDONLY);
1129 	unsigned int foo;
1130 
1131 	if (fd > 0) {
1132 		int ret = read(fd, &foo, sizeof(foo));
1133 
1134 		if (ret < 0)
1135 			srand(fd + foo);
1136 		close(fd);
1137 	}
1138 
1139 	srand(foo);
1140 }
1141 
1142 static void xsetsockopt(int fd, int level, int optname, const void *optval, socklen_t optlen)
1143 {
1144 	int err;
1145 
1146 	err = setsockopt(fd, level, optname, optval, optlen);
1147 	if (err) {
1148 		perror("setsockopt");
1149 		exit(1);
1150 	}
1151 }
1152 
1153 static void apply_cmsg_types(int fd, const struct cfg_cmsg_types *cmsg)
1154 {
1155 	static const unsigned int on = 1;
1156 
1157 	if (cmsg->timestampns)
1158 		xsetsockopt(fd, SOL_SOCKET, SO_TIMESTAMPNS_NEW, &on, sizeof(on));
1159 	if (cmsg->tcp_inq)
1160 		xsetsockopt(fd, IPPROTO_TCP, TCP_INQ, &on, sizeof(on));
1161 }
1162 
1163 static void parse_cmsg_types(const char *type)
1164 {
1165 	char *next = strchr(type, ',');
1166 	unsigned int len = 0;
1167 
1168 	cfg_cmsg_types.cmsg_enabled = 1;
1169 
1170 	if (next) {
1171 		parse_cmsg_types(next + 1);
1172 		len = next - type;
1173 	} else {
1174 		len = strlen(type);
1175 	}
1176 
1177 	if (strncmp(type, "TIMESTAMPNS", len) == 0) {
1178 		cfg_cmsg_types.timestampns = 1;
1179 		return;
1180 	}
1181 
1182 	if (strncmp(type, "TCPINQ", len) == 0) {
1183 		cfg_cmsg_types.tcp_inq = 1;
1184 		return;
1185 	}
1186 
1187 	fprintf(stderr, "Unrecognized cmsg option %s\n", type);
1188 	exit(1);
1189 }
1190 
1191 static void parse_setsock_options(const char *name)
1192 {
1193 	char *next = strchr(name, ',');
1194 	unsigned int len = 0;
1195 
1196 	if (next) {
1197 		parse_setsock_options(next + 1);
1198 		len = next - name;
1199 	} else {
1200 		len = strlen(name);
1201 	}
1202 
1203 	if (strncmp(name, "TRANSPARENT", len) == 0) {
1204 		cfg_sockopt_types.transparent = 1;
1205 		return;
1206 	}
1207 
1208 	if (strncmp(name, "MPTFO", len) == 0) {
1209 		cfg_sockopt_types.mptfo = 1;
1210 		return;
1211 	}
1212 
1213 	fprintf(stderr, "Unrecognized setsockopt option %s\n", name);
1214 	exit(1);
1215 }
1216 
1217 void xdisconnect(int fd, int addrlen)
1218 {
1219 	struct sockaddr_storage empty;
1220 	int msec_sleep = 10;
1221 	int queued = 1;
1222 	int i;
1223 
1224 	shutdown(fd, SHUT_WR);
1225 
1226 	/* while until the pending data is completely flushed, the later
1227 	 * disconnect will bypass/ignore/drop any pending data.
1228 	 */
1229 	for (i = 0; ; i += msec_sleep) {
1230 		if (ioctl(fd, SIOCOUTQ, &queued) < 0)
1231 			xerror("can't query out socket queue: %d", errno);
1232 
1233 		if (!queued)
1234 			break;
1235 
1236 		if (i > poll_timeout)
1237 			xerror("timeout while waiting for spool to complete");
1238 		usleep(msec_sleep * 1000);
1239 	}
1240 
1241 	memset(&empty, 0, sizeof(empty));
1242 	empty.ss_family = AF_UNSPEC;
1243 	if (connect(fd, (struct sockaddr *)&empty, addrlen) < 0)
1244 		xerror("can't disconnect: %d", errno);
1245 }
1246 
1247 int main_loop(void)
1248 {
1249 	int fd = 0, ret, fd_in = 0;
1250 	struct addrinfo *peer;
1251 	struct wstate winfo;
1252 
1253 	if (cfg_input && cfg_sockopt_types.mptfo) {
1254 		fd_in = open(cfg_input, O_RDONLY);
1255 		if (fd < 0)
1256 			xerror("can't open %s:%d", cfg_input, errno);
1257 	}
1258 
1259 	memset(&winfo, 0, sizeof(winfo));
1260 	fd = sock_connect_mptcp(cfg_host, cfg_port, cfg_sock_proto, &peer, fd_in, &winfo);
1261 	if (fd < 0)
1262 		return 2;
1263 
1264 again:
1265 	check_getpeername_connect(fd);
1266 
1267 	SOCK_TEST_TCPULP(fd, cfg_sock_proto);
1268 
1269 	if (cfg_rcvbuf)
1270 		set_rcvbuf(fd, cfg_rcvbuf);
1271 	if (cfg_sndbuf)
1272 		set_sndbuf(fd, cfg_sndbuf);
1273 	if (cfg_cmsg_types.cmsg_enabled)
1274 		apply_cmsg_types(fd, &cfg_cmsg_types);
1275 
1276 	if (cfg_input && !cfg_sockopt_types.mptfo) {
1277 		fd_in = open(cfg_input, O_RDONLY);
1278 		if (fd < 0)
1279 			xerror("can't open %s:%d", cfg_input, errno);
1280 	}
1281 
1282 	ret = copyfd_io(fd_in, fd, 1, 0, &winfo);
1283 	if (ret)
1284 		return ret;
1285 
1286 	if (cfg_truncate > 0) {
1287 		xdisconnect(fd, peer->ai_addrlen);
1288 	} else if (--cfg_repeat > 0) {
1289 		xdisconnect(fd, peer->ai_addrlen);
1290 
1291 		/* the socket could be unblocking at this point, we need the
1292 		 * connect to be blocking
1293 		 */
1294 		set_nonblock(fd, false);
1295 		if (connect(fd, peer->ai_addr, peer->ai_addrlen))
1296 			xerror("can't reconnect: %d", errno);
1297 		if (cfg_input)
1298 			close(fd_in);
1299 		memset(&winfo, 0, sizeof(winfo));
1300 		goto again;
1301 	} else {
1302 		close(fd);
1303 	}
1304 
1305 	return 0;
1306 }
1307 
1308 int parse_proto(const char *proto)
1309 {
1310 	if (!strcasecmp(proto, "MPTCP"))
1311 		return IPPROTO_MPTCP;
1312 	if (!strcasecmp(proto, "TCP"))
1313 		return IPPROTO_TCP;
1314 
1315 	fprintf(stderr, "Unknown protocol: %s\n.", proto);
1316 	die_usage();
1317 
1318 	/* silence compiler warning */
1319 	return 0;
1320 }
1321 
1322 int parse_mode(const char *mode)
1323 {
1324 	if (!strcasecmp(mode, "poll"))
1325 		return CFG_MODE_POLL;
1326 	if (!strcasecmp(mode, "mmap"))
1327 		return CFG_MODE_MMAP;
1328 	if (!strcasecmp(mode, "sendfile"))
1329 		return CFG_MODE_SENDFILE;
1330 
1331 	fprintf(stderr, "Unknown test mode: %s\n", mode);
1332 	fprintf(stderr, "Supported modes are:\n");
1333 	fprintf(stderr, "\t\t\"poll\" - interleaved read/write using poll()\n");
1334 	fprintf(stderr, "\t\t\"mmap\" - send entire input file (mmap+write), then read response (-l will read input first)\n");
1335 	fprintf(stderr, "\t\t\"sendfile\" - send entire input file (sendfile), then read response (-l will read input first)\n");
1336 
1337 	die_usage();
1338 
1339 	/* silence compiler warning */
1340 	return 0;
1341 }
1342 
1343 int parse_peek(const char *mode)
1344 {
1345 	if (!strcasecmp(mode, "saveWithPeek"))
1346 		return CFG_WITH_PEEK;
1347 	if (!strcasecmp(mode, "saveAfterPeek"))
1348 		return CFG_AFTER_PEEK;
1349 
1350 	fprintf(stderr, "Unknown: %s\n", mode);
1351 	fprintf(stderr, "Supported MSG_PEEK mode are:\n");
1352 	fprintf(stderr,
1353 		"\t\t\"saveWithPeek\" - recv data with flags 'MSG_PEEK' and save the peek data into file\n");
1354 	fprintf(stderr,
1355 		"\t\t\"saveAfterPeek\" - read and save data into file after recv with flags 'MSG_PEEK'\n");
1356 
1357 	die_usage();
1358 
1359 	/* silence compiler warning */
1360 	return 0;
1361 }
1362 
1363 static int parse_int(const char *size)
1364 {
1365 	unsigned long s;
1366 
1367 	errno = 0;
1368 
1369 	s = strtoul(size, NULL, 0);
1370 
1371 	if (errno) {
1372 		fprintf(stderr, "Invalid sndbuf size %s (%s)\n",
1373 			size, strerror(errno));
1374 		die_usage();
1375 	}
1376 
1377 	if (s > INT_MAX) {
1378 		fprintf(stderr, "Invalid sndbuf size %s (%s)\n",
1379 			size, strerror(ERANGE));
1380 		die_usage();
1381 	}
1382 
1383 	return (int)s;
1384 }
1385 
1386 static void parse_opts(int argc, char **argv)
1387 {
1388 	int c;
1389 
1390 	while ((c = getopt(argc, argv, "6c:f:hi:I:jlm:M:o:p:P:r:R:s:S:t:T:w:")) != -1) {
1391 		switch (c) {
1392 		case 'f':
1393 			cfg_truncate = atoi(optarg);
1394 
1395 			/* when receiving a fastclose, ignore PIPE signals and
1396 			 * all the I/O errors later in the code
1397 			 */
1398 			if (cfg_truncate < 0) {
1399 				cfg_rcv_trunc = true;
1400 				signal(SIGPIPE, handle_signal);
1401 			}
1402 			break;
1403 		case 'j':
1404 			cfg_join = true;
1405 			cfg_mode = CFG_MODE_POLL;
1406 			break;
1407 		case 'r':
1408 			cfg_remove = true;
1409 			cfg_mode = CFG_MODE_POLL;
1410 			cfg_wait = 400000;
1411 			cfg_do_w = atoi(optarg);
1412 			if (cfg_do_w <= 0)
1413 				cfg_do_w = 50;
1414 			break;
1415 		case 'i':
1416 			cfg_input = optarg;
1417 			break;
1418 		case 'I':
1419 			cfg_repeat = atoi(optarg);
1420 			break;
1421 		case 'l':
1422 			listen_mode = true;
1423 			break;
1424 		case 'p':
1425 			cfg_port = optarg;
1426 			break;
1427 		case 's':
1428 			cfg_sock_proto = parse_proto(optarg);
1429 			break;
1430 		case 'h':
1431 			die_usage();
1432 			break;
1433 		case '6':
1434 			pf = AF_INET6;
1435 			break;
1436 		case 't':
1437 			poll_timeout = atoi(optarg) * 1000;
1438 			if (poll_timeout <= 0)
1439 				poll_timeout = -1;
1440 			break;
1441 		case 'T':
1442 			cfg_time = atoi(optarg);
1443 			break;
1444 		case 'm':
1445 			cfg_mode = parse_mode(optarg);
1446 			break;
1447 		case 'S':
1448 			cfg_sndbuf = parse_int(optarg);
1449 			break;
1450 		case 'R':
1451 			cfg_rcvbuf = parse_int(optarg);
1452 			break;
1453 		case 'w':
1454 			cfg_wait = atoi(optarg)*1000000;
1455 			break;
1456 		case 'M':
1457 			cfg_mark = strtol(optarg, NULL, 0);
1458 			break;
1459 		case 'P':
1460 			cfg_peek = parse_peek(optarg);
1461 			break;
1462 		case 'c':
1463 			parse_cmsg_types(optarg);
1464 			break;
1465 		case 'o':
1466 			parse_setsock_options(optarg);
1467 			break;
1468 		}
1469 	}
1470 
1471 	if (optind + 1 != argc)
1472 		die_usage();
1473 	cfg_host = argv[optind];
1474 
1475 	if (strchr(cfg_host, ':'))
1476 		pf = AF_INET6;
1477 }
1478 
1479 int main(int argc, char *argv[])
1480 {
1481 	init_rng();
1482 
1483 	signal(SIGUSR1, handle_signal);
1484 	parse_opts(argc, argv);
1485 
1486 	if (listen_mode) {
1487 		int fd = sock_listen_mptcp(cfg_host, cfg_port);
1488 
1489 		if (fd < 0)
1490 			return 1;
1491 
1492 		if (cfg_rcvbuf)
1493 			set_rcvbuf(fd, cfg_rcvbuf);
1494 		if (cfg_sndbuf)
1495 			set_sndbuf(fd, cfg_sndbuf);
1496 		if (cfg_mark)
1497 			set_mark(fd, cfg_mark);
1498 		if (cfg_cmsg_types.cmsg_enabled)
1499 			apply_cmsg_types(fd, &cfg_cmsg_types);
1500 
1501 		return main_loop_s(fd);
1502 	}
1503 
1504 	return main_loop();
1505 }
1506