text: /*-
   * Copyright (c) 2006 Robert N. M. Watson
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in the
   *    documentation and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
   * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
   * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
   * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
   * SUCH DAMAGE.
   *
   * $FreeBSD$
   */
  
  /*
   * TCP regression test which opens a loopback TCP session, and closes it
   * before the remote endpoint (server) can accept it.  Run the test twice,
   * once using an explicit close() from the client, a second using a tcp drop.
   */
  
  #include <sys/types.h>
  #include <sys/socket.h>
  #include <sys/sysctl.h>
  
  #include <netinet/in.h>
  
  #include <err.h>
  #include <errno.h>
  #include <signal.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  
  #define	TCP_PORT	9005
  
  static int
  tcp_drop(struct sockaddr_in *sin_local, struct sockaddr_in *sin_remote)
  {
  	struct sockaddr_storage addrs[2];
  
  	/*
  	 * Sysctl accepts an array of two sockaddr's, the first being the
  	 * 'foreign' sockaddr, the second being the 'local' sockaddr.
  	 */
  
  	bcopy(sin_remote, &addrs[0], sizeof(*sin_remote));
  	bcopy(sin_local, &addrs[1], sizeof(*sin_local));
  
  	return (sysctlbyname("net.inet.tcp.drop", NULL, 0, addrs,
  	    sizeof(addrs)));
  }
  
  
  static void
  tcp_server(pid_t partner)
  {
  	int error, listen_fd, accept_fd;
  	struct sockaddr_in sin;
  
  	listen_fd = socket(PF_INET, SOCK_STREAM, 0);
  	if (listen_fd < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "tcp_server: socket");
  	}
  
  	bzero(&sin, sizeof(sin));
  	sin.sin_family = AF_INET;
  	sin.sin_len = sizeof(sin);
  	sin.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  	sin.sin_port = htons(TCP_PORT);
  
  	if (bind(listen_fd, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "tcp_server: bind");
  	}
  
  	if (listen(listen_fd, -1) < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "tcp_server: listen");
  	}
  
  	sleep(10);
  
  	accept_fd = accept(listen_fd, NULL, NULL);
  	if (accept_fd < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "tcp_server: accept");
  	}
  	close(accept_fd);
  	close(listen_fd);
  }
  
  static void
  tcp_client(pid_t partner, int dropflag)
  {
  	struct sockaddr_in sin, sin_local;
  	int error, sock;
  	socklen_t slen;
  
  	sleep(1);
  
  	sock = socket(PF_INET, SOCK_STREAM, 0);
  	if (sock < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "socket");
  	}
  
  	bzero(&sin, sizeof(sin));
  	sin.sin_family = AF_INET;
  	sin.sin_len = sizeof(sin);
  	sin.sin_addr.s_addr = ntohl(INADDR_LOOPBACK);
  	sin.sin_port = htons(TCP_PORT);
  
  	if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "connect");
  	}
  
  	slen = sizeof(sin_local);
  	if (getsockname(sock, (struct sockaddr *)&sin_local, &slen) < 0) {
  		error = errno;
  		(void)kill(partner, SIGKILL);
  		errno = error;
  		err(-1, "getsockname");
  	}
  
  	if (dropflag) {
  		if (tcp_drop(&sin_local, &sin) < 0) {
  			error = errno;
  			(void)kill(partner, SIGKILL);
  			errno = error;
  			err(-1, "tcp_drop");
  		}
  		sleep(2);
  	}
  	close(sock);
  }
  
  int
  main(int argc, char *argv[])
  {
  	pid_t child_pid, parent_pid;
  
  	if (signal(SIGCHLD, SIG_IGN) == SIG_ERR)
  		err(-1, "signal");
  
  	parent_pid = getpid();
  	child_pid = fork();
  	if (child_pid < 0)
  		err(-1, "fork");
  	if (child_pid == 0) {
  		child_pid = getpid();
  		tcp_server(parent_pid);
  		return (0);
  	} else
  		tcp_client(child_pid, 0);
  	(void)kill(child_pid, SIGTERM);
  
  	sleep(5);
  
  	parent_pid = getpid();
  	child_pid = fork();
  	if (child_pid < 0)
  		err(-1, "fork");
  	if (child_pid == 0) {
  		child_pid = getpid();
  		tcp_server(parent_pid);
  		return (0);
  	} else
  		tcp_client(child_pid, 1);
  	(void)kill(child_pid, SIGTERM);
  
  	return (0);
  }
  