--- netcat-4.0.20061122/usr.bin/nc/netcat.c

+++ netcat-4.0.20061122/usr.bin/nc/netcat.c

@@ -323,6 +323,8 @@ main(int argc, char *argv[])

 				len = sizeof(cliaddr);

 				connfd = accept(s, (struct sockaddr *)&cliaddr,

 				    &len);

+				if (connfd < 0)

+					err(1, "accept");

 			}

 			readwrite(connfd);

@@ -355,6 +357,15 @@ main(int argc, char *argv[])

 			if (s)

 				close(s);

+			/* Don't lookup port if -n */

+			if (nflag)

+				sv = NULL;

+			else {

+				sv = getservbyport(

+				    ntohs(atoi(portlist[i])),

+				    uflag ? "udp" : "tcp");

+			}

+

 			if (xflag)

 				s = socks_connect(host, portlist[i], hints,

 				    proxyhost, proxyport, proxyhints, socksv,

@@ -362,33 +373,32 @@ main(int argc, char *argv[])

 			else

 				s = remote_connect(host, portlist[i], hints);

-			if (s < 0)

-				continue;

-

 			ret = 0;

-			if (vflag || zflag) {

-				/* For UDP, make sure we are connected. */

-				if (uflag) {

-					if (udptest(s) == -1) {

-						ret = 1;

-						continue;

-					}

-				}

-				/* Don't look up port if -n. */

-				if (nflag)

-					sv = NULL;

-				else {

-					sv = getservbyport(

-					    ntohs(atoi(portlist[i])),

-					    uflag ? "udp" : "tcp");

+			if (s >= 0) {

+				if (uflag && zflag)

+					ret = (udptest(s) == -1) ? 1 : 0;

+			} else

+				ret = 1;

+

+			if (vflag) {

+				if (ret) {

+					printf("Connection to %s %s port "

+						"[%s/%s] failed : %s\n",

+						host, portlist[i],

+						uflag ? "udp" : "tcp",

+						sv ? sv->s_name : "*",

+						strerror(errno));

+				} else {

+					printf("Connection to %s %s port "

+						"[%s/%s] succeeded!\n",

+						host, portlist[i],

+						uflag ? "udp" : "tcp",

+						sv ? sv->s_name : "*");

 				}

-

-				printf("Connection to %s %s port [%s/%s] succeeded!\n",

-				    host, portlist[i], uflag ? "udp" : "tcp",

-				    sv ? sv->s_name : "*");

 			}

-			if (!zflag)

+

+			if (!zflag && !ret)

 				readwrite(s);

 		}

 	}

@@ -410,7 +420,7 @@ unix_connect(char *path)

 	int s;

 	if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)

-		return (-1);

+		err(1, "socket");

 	(void)fcntl(s, F_SETFD, 1);

 	memset(&sun, 0, sizeof(struct sockaddr_un));

@@ -421,8 +431,7 @@ unix_connect(char *path)

 	strcpy(sun.sun_path, path);

 	if (connect(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) {

-		close(s);

-		return (-1);

+		err(1, "connect");

 	}

 	return (s);

@@ -440,7 +449,7 @@ unix_listen(char *path)

 	/* Create unix domain socket. */

 	if ((s = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)

-		return (-1);

+		err(1, "socket");

 	memset(&sun, 0, sizeof(struct sockaddr_un));

 	sun.sun_family = AF_UNIX;

@@ -450,13 +459,11 @@ unix_listen(char *path)

 	strcpy(sun.sun_path, path);

 	if (bind(s, (struct sockaddr *)&sun, SUN_LEN(&sun)) < 0) {

-		close(s);

-		return (-1);

+		err(1, "bind");

 	}

 	if (listen(s, 5) < 0) {

-		close(s);

-		return (-1);

+		err(1, "listen");

 	}

 	return (s);

 }

@@ -471,6 +478,7 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)

 {

 	struct addrinfo *res, *res0;

 	int s, error;

+	int saved_errno = 0;

 	if ((error = getaddrinfo(host, port, &hints, &res)))

 		errx(1, "getaddrinfo: %s", gai_strerror(error));

@@ -494,8 +502,13 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)

 				errx(1, "getaddrinfo: %s", gai_strerror(error));

 			if (bind(s, (struct sockaddr *)ares->ai_addr,

-			    ares->ai_addrlen) < 0)

-				errx(1, "bind failed: %s", strerror(errno));

+			    ares->ai_addrlen) < 0) {

+				warn("bind");

+				freeaddrinfo(ares);

+				close(s);

+				s = -1;

+				continue;

+			}

 			freeaddrinfo(ares);

 		}

@@ -503,7 +516,11 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)

 		if (connect(s, res0->ai_addr, res0->ai_addrlen) == 0)

 			break;

-		else if (vflag)

+

+		if (!saved_errno)

+			saved_errno = errno;

+

+		if (vflag)

 			warn("connect to %s port %s (%s) failed", host, port,

 			    uflag ? "udp" : "tcp");

@@ -513,6 +530,9 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)

 	freeaddrinfo(res);

+	if (!errno && saved_errno)

+		errno = saved_errno;

+

 	return (s);

 }

@@ -549,25 +569,26 @@ local_listen(char *host, char *port, struct addrinfo hints)

 		ret = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));

 		if (ret == -1)

-			err(1, NULL);

+			err(1, "setsockopt");

 		set_common_sockopts(s);

 		if (bind(s, (struct sockaddr *)res0->ai_addr,

 		    res0->ai_addrlen) == 0)

 			break;

+		warn("bind");

 		close(s);

 		s = -1;

 	} while ((res0 = res0->ai_next) != NULL);

+	freeaddrinfo(res);

+

 	if (!uflag && s != -1) {

 		if (listen(s, 1) < 0)

 			err(1, "listen");

 	}

-	freeaddrinfo(res);

-

 	return (s);

 }

@@ -606,7 +627,7 @@ readwrite(int nfd)

 		if (n == 0)

 			return;

-		if (pfd[0].revents & POLLIN) {

+		if (pfd[0].revents & (POLLIN | POLLERR)) {

 			if ((n = read(nfd, buf, plen)) < 0)

 				return;

 			else if (n == 0) {

@@ -733,24 +754,14 @@ build_ports(char *p)

 	}

 }

-/*

- * udptest()

- * Do a few writes to see if the UDP port is there.

- * XXX - Better way of doing this? Doesn't work for IPv6.

- * Also fails after around 100 ports checked.

- */

 int

 udptest(int s)

 {

-	int i, ret;

+	write(s, "X", 1);

-	for (i = 0; i <= 3; i++) {

-		if (write(s, "X", 1) == 1)

-			ret = 1;

-		else

-			ret = -1;

-	}

-	return (ret);

+	sleep(3);

+

+	return (write(s, "X", 1) == 1) ? 1 : -1;

 }

 void