Add a simple C-based TCP connection generator, which generates and

closes the specified number of TCP connections sequentially and
synchronously.  Useful for trying to trigger races in the accept
code.

tools/regression/netinet/tcpconnect/Makefile

@@ -0,0 +1,8 @@
+#
+# $FreeBSD$
+#
+
+PROG=	tcpconnect
+NOMAN=	yes
+
+.include <bsd.prog.mk>

tools/regression/netinet/tcpconnect/tcpconnect.c

@@ -0,0 +1,152 @@
+/*-
+ * Copyright (c) 2004 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <netinet/in.h>
+
+#include <arpa/inet.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static void
+usage(volid)
+{
+
+	fprintf(stderr, "tcpconnect server port\n");
+	fprintf(stderr, "tcpconnect client ip port count\n");
+	exit(-1);
+}
+
+static void
+tcpconnect_server(int argc, char *argv[])
+{
+	int listen_sock, accept_sock;
+	struct sockaddr_in sin;
+	char *dummy;
+	long port;
+
+	if (argc != 1)
+		usage();
+
+	bzero(&sin, sizeof(sin));
+	sin.sin_len = sizeof(sin);
+	sin.sin_family = AF_INET;
+	sin.sin_addr.s_addr = htonl(INADDR_ANY);
+
+	port = strtoul(argv[0], &dummy, 10);
+	if (port < 1 || port > 65535 || *dummy != '\0')
+		usage();
+	sin.sin_port = htons(port);
+
+	listen_sock = socket(PF_INET, SOCK_STREAM, 0);
+	if (listen_sock == -1) {
+		perror("socket");
+		exit(-1);
+	}
+
+	if (bind(listen_sock, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
+		perror("bind");
+		exit(-1);
+	}
+
+	if (listen(listen_sock, -1) == -1) {
+		perror("listen");
+		exit(1);
+	}
+
+	while (1) {
+		accept_sock = accept(listen_sock, NULL, NULL);
+		close(accept_sock);
+	}
+}
+
+static void
+tcpconnect_client(int argc, char *argv[])
+{
+	struct sockaddr_in sin;
+	long count, i, port;
+	char *dummy;
+	int sock;
+
+	if (argc != 3)
+		usage();
+
+	bzero(&sin, sizeof(sin));
+	sin.sin_len = sizeof(sin);
+	sin.sin_family = AF_INET;
+	if (inet_aton(argv[0], &sin.sin_addr) == 0) {
+		perror(argv[0]);
+		exit(-1);
+	}
+
+	port = strtoul(argv[1], &dummy, 10);
+	if (port < 1 || port > 65535 || *dummy != '\0')
+		usage();
+	sin.sin_port = htons(port);
+
+	count = strtoul(argv[2], &dummy, 10);
+	if (count < 1 || count > 100000 || *dummy != '\0')
+		usage();
+
+	for (i = 0; i < count; i++) {
+		sock = socket(PF_INET, SOCK_STREAM, 0);
+		if (sock == -1) {
+			perror("socket");
+			exit(-1);
+		}
+
+		if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
+			perror("connect");
+			exit(-1);
+		}
+
+		close(sock);
+	}
+}
+
+int
+main(int argc, char *argv[])
+{
+
+	if (argc < 2)
+		usage();
+
+	if (strcmp(argv[1], "server") == 0)
+		tcpconnect_server(argc - 2, argv + 2);
+	else if (strcmp(argv[1], "client") == 0)
+		tcpconnect_client(argc - 2, argv + 2);
+	else
+		usage();
+
+	exit(0);
+}