This patch is based on db2b1d9a8d4644ef892f47d84606ee96598d23fb
of http://anonscm.debian.org/cgit/collab-maint/netcat-openbsd.git

From: Aron Xu <aron@debian.org>
Date: Mon, 13 Feb 2012 15:59:31 +0800
Subject: port to linux with libsd

---
 Makefile |   17 ++++++++--
 nc.1     |    4 +--
 netcat.c |  105 +++++++++++++++++++++++++++++++++++++++++++++++++++++---------
 socks.c  |   46 +++++++++++++--------------
 4 files changed, 130 insertions(+), 42 deletions(-)

diff --git a/Makefile b/Makefile
index 150f829..96a6587 100644
--- a/Makefile
+++ b/Makefile
@@ -1,6 +1,19 @@
-#	$OpenBSD: Makefile,v 1.6 2001/09/02 18:45:41 jakob Exp $
+#       $OpenBSD: Makefile,v 1.6 2001/09/02 18:45:41 jakob Exp $

 PROG=	nc
 SRCS=	netcat.c atomicio.c socks.c

-.include <bsd.prog.mk>
+LIBS=  `pkg-config --libs libbsd` -lresolv
+OBJS=  $(SRCS:.c=.o)
+CFLAGS=  -g -O2
+LDFLAGS=  -Wl,--no-add-needed
+
+all: nc
+nc: $(OBJS)
+	$(CC) $(CFLAGS) $(LDFLAGS) $(OBJS) $(LIBS) -o nc
+
+$(OBJS): %.o: %.c
+	$(CC) $(CFLAGS) -c $< -o $@
+
+clean:
+	rm -f $(OBJS) nc
diff --git a/nc.1 b/nc.1
index 75d1437..b7014a2 100644
--- a/nc.1
+++ b/nc.1
@@ -146,9 +146,6 @@ Proxy authentication is only supported for HTTP CONNECT proxies at present.
 Specifies the source port
 .Nm
 should use, subject to privilege restrictions and availability.
-It is an error to use this option in conjunction with the
-.Fl l
-option.
 .It Fl r
 Specifies that source and/or destination ports should be chosen randomly
 instead of sequentially within a range or in the order that the system
@@ -170,6 +167,7 @@ Change IPv4 TOS value.
 may be one of
 .Ar critical ,
 .Ar inetcontrol ,
+.Ar lowcost ,
 .Ar lowdelay ,
 .Ar netcontrol ,
 .Ar throughput ,
diff --git a/netcat.c b/netcat.c
index cc4683a..9b2def2 100644
--- a/netcat.c
+++ b/netcat.c
@@ -42,6 +42,46 @@
 #include <netinet/ip.h>
 #include <arpa/telnet.h>

+#ifndef IPTOS_LOWDELAY
+# define IPTOS_LOWDELAY 0x10
+# define IPTOS_THROUGHPUT 0x08
+# define IPTOS_RELIABILITY 0x04
+# define IPTOS_LOWCOST 0x02
+# define IPTOS_MINCOST IPTOS_LOWCOST
+#endif /* IPTOS_LOWDELAY */
+
+# ifndef IPTOS_DSCP_AF11
+# define	IPTOS_DSCP_AF11		0x28
+# define	IPTOS_DSCP_AF12		0x30
+# define	IPTOS_DSCP_AF13		0x38
+# define	IPTOS_DSCP_AF21		0x48
+# define	IPTOS_DSCP_AF22		0x50
+# define	IPTOS_DSCP_AF23		0x58
+# define	IPTOS_DSCP_AF31		0x68
+# define	IPTOS_DSCP_AF32		0x70
+# define	IPTOS_DSCP_AF33		0x78
+# define	IPTOS_DSCP_AF41		0x88
+# define	IPTOS_DSCP_AF42		0x90
+# define	IPTOS_DSCP_AF43		0x98
+# define	IPTOS_DSCP_EF		0xb8
+#endif /* IPTOS_DSCP_AF11 */
+
+#ifndef IPTOS_DSCP_CS0
+# define	IPTOS_DSCP_CS0		0x00
+# define	IPTOS_DSCP_CS1		0x20
+# define	IPTOS_DSCP_CS2		0x40
+# define	IPTOS_DSCP_CS3		0x60
+# define	IPTOS_DSCP_CS4		0x80
+# define	IPTOS_DSCP_CS5		0xa0
+# define	IPTOS_DSCP_CS6		0xc0
+# define	IPTOS_DSCP_CS7		0xe0
+#endif /* IPTOS_DSCP_CS0 */
+
+#ifndef IPTOS_DSCP_EF
+# define	IPTOS_DSCP_EF		0xb8
+#endif /* IPTOS_DSCP_EF */
+
+
 #include <err.h>
 #include <errno.h>
 #include <netdb.h>
@@ -53,6 +93,8 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <limits.h>
+#include <bsd/stdlib.h>
+#include <bsd/string.h>
 #include "atomicio.h"

 #ifndef SUN_LEN
@@ -118,7 +160,7 @@ main(int argc, char *argv[])
 	struct servent *sv;
 	socklen_t len;
 	struct sockaddr_storage cliaddr;
-	char *proxy;
+	char *proxy = NULL;
 	const char *errstr, *proxyhost = "", *proxyport = NULL;
 	struct addrinfo proxyhints;
 	char unix_dg_tmp_socket_buf[UNIX_DG_TMP_SOCKET_SIZE];
@@ -164,7 +206,11 @@ main(int argc, char *argv[])
 				errx(1, "interval %s: %s", errstr, optarg);
 			break;
 		case 'j':
+# if defined(SO_JUMBO)
 			jflag = 1;
+# else
+			errx(1, "no jumbo frame support available");
+# endif
 			break;
 		case 'k':
 			kflag = 1;
@@ -194,10 +240,14 @@ main(int argc, char *argv[])
 			uflag = 1;
 			break;
 		case 'V':
+# if defined(RT_TABLEID_MAX)
 			rtableid = (unsigned int)strtonum(optarg, 0,
 			    RT_TABLEID_MAX, &errstr);
 			if (errstr)
 				errx(1, "rtable %s: %s", errstr, optarg);
+# else
+			errx(1, "no alternate routing table support available");
+# endif
 			break;
 		case 'v':
 			vflag = 1;
@@ -232,7 +282,11 @@ main(int argc, char *argv[])
 				    errstr, optarg);
 			break;
 		case 'S':
+# if defined(TCP_MD5SIG)
 			Sflag = 1;
+# else
+			errx(1, "no TCP MD5 signature support available");
+# endif
 			break;
 		case 'T':
 			errstr = NULL;
@@ -259,6 +313,15 @@ main(int argc, char *argv[])
 	if (argv[0] && !argv[1] && family == AF_UNIX) {
 		host = argv[0];
 		uport = NULL;
+	} else if (!argv[0] && lflag) {
+		if (sflag)
+			errx(1, "cannot use -s and -l");
+		if (zflag)
+			errx(1, "cannot use -z and -l");
+		if (pflag)
+			uport=pflag;
+	} else if (!lflag && kflag) {
+		errx(1, "cannot use -k without -l");
 	} else if (argv[0] && !argv[1]) {
 		if  (!lflag)
 			usage(1);
@@ -270,14 +333,7 @@ main(int argc, char *argv[])
 	} else
 		usage(1);

-	if (lflag && sflag)
-		errx(1, "cannot use -s and -l");
-	if (lflag && pflag)
-		errx(1, "cannot use -p and -l");
-	if (lflag && zflag)
-		errx(1, "cannot use -z and -l");
-	if (!lflag && kflag)
-		errx(1, "must use -l with -k");
+

 	/* Get name of temporary socket for unix datagram client */
 	if ((family == AF_UNIX) && uflag && !lflag) {
@@ -286,8 +342,8 @@ main(int argc, char *argv[])
 		} else {
 			strlcpy(unix_dg_tmp_socket_buf, "/tmp/nc.XXXXXXXXXX",
 				UNIX_DG_TMP_SOCKET_SIZE);
-			if (mktemp(unix_dg_tmp_socket_buf) == NULL)
-				err(1, "mktemp");
+			if (mkstemp(unix_dg_tmp_socket_buf) == -1)
+				err(1, "mkstemp");
 			unix_dg_tmp_socket = unix_dg_tmp_socket_buf;
 		}
 	}
@@ -563,18 +619,22 @@ remote_connect(const char *host, const char *port, struct addrinfo hints)
 		    res0->ai_protocol)) < 0)
 			continue;

+# if defined(RT_TABLEID_MAX)
 		if (rtableid) {
 			if (setsockopt(s, SOL_SOCKET, SO_RTABLE, &rtableid,
 			    sizeof(rtableid)) == -1)
 				err(1, "setsockopt SO_RTABLE");
 		}
+# endif

 		/* Bind to a local port or source address if specified. */
 		if (sflag || pflag) {
 			struct addrinfo ahints, *ares;

+# if defined (SO_BINDANY)
 			/* try SO_BINDANY, but don't insist */
 			setsockopt(s, SOL_SOCKET, SO_BINDANY, &on, sizeof(on));
+# endif
 			memset(&ahints, 0, sizeof(struct addrinfo));
 			ahints.ai_family = res0->ai_family;
 			ahints.ai_socktype = uflag ? SOCK_DGRAM : SOCK_STREAM;
@@ -674,15 +734,23 @@ local_listen(char *host, char *port, struct addrinfo hints)
 		    res0->ai_protocol)) < 0)
 			continue;

+# if defined(RT_TABLEID_MAX)
 		if (rtableid) {
 			if (setsockopt(s, IPPROTO_IP, SO_RTABLE, &rtableid,
 			    sizeof(rtableid)) == -1)
 				err(1, "setsockopt SO_RTABLE");
 		}
+# endif
+
+		ret = setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &x, sizeof(x));
+		if (ret == -1)
+			err(1, NULL);

+# if defined(SO_REUSEPORT)
 		ret = setsockopt(s, SOL_SOCKET, SO_REUSEPORT, &x, sizeof(x));
 		if (ret == -1)
 			err(1, NULL);
+# endif

 		set_common_sockopts(s);

@@ -886,21 +954,25 @@ set_common_sockopts(int s)
 {
 	int x = 1;

+# if defined(TCP_MD5SIG)
 	if (Sflag) {
 		if (setsockopt(s, IPPROTO_TCP, TCP_MD5SIG,
 			&x, sizeof(x)) == -1)
 			err(1, NULL);
 	}
+# endif
 	if (Dflag) {
 		if (setsockopt(s, SOL_SOCKET, SO_DEBUG,
 			&x, sizeof(x)) == -1)
 			err(1, NULL);
 	}
+# if defined(SO_JUMBO)
 	if (jflag) {
 		if (setsockopt(s, SOL_SOCKET, SO_JUMBO,
 			&x, sizeof(x)) == -1)
 			err(1, NULL);
 	}
+# endif
 	if (Tflag != -1) {
 		if (setsockopt(s, IPPROTO_IP, IP_TOS,
 		    &Tflag, sizeof(Tflag)) == -1)
@@ -949,6 +1021,7 @@ map_tos(char *s, int *val)
 		{ "cs7",		IPTOS_DSCP_CS7 },
 		{ "ef",			IPTOS_DSCP_EF },
 		{ "inetcontrol",	IPTOS_PREC_INTERNETCONTROL },
+		{ "lowcost",		IPTOS_LOWCOST },
 		{ "lowdelay",		IPTOS_LOWDELAY },
 		{ "netcontrol",		IPTOS_PREC_NETCONTROL },
 		{ "reliability",	IPTOS_RELIABILITY },
@@ -969,6 +1042,9 @@ map_tos(char *s, int *val)
 void
 help(void)
 {
+# if defined(DEBIAN_VERSION)
+        fprintf(stderr, "OpenBSD netcat (Debian patchlevel " DEBIAN_VERSION ")\n");
+# endif
 	usage(0);
 	fprintf(stderr, "\tCommand Summary:\n\
 	\t-4		Use IPv4\n\
@@ -978,6 +1054,7 @@ help(void)
 	\t-h		This help text\n\
 	\t-I length	TCP receive buffer length\n\
 	\t-i secs\t	Delay interval for lines sent, ports scanned\n\
+	\t-j		Use jumbo frame\n\
 	\t-k		Keep inbound sockets open for multiple connects\n\
 	\t-l		Listen mode, for inbound connects\n\
 	\t-n		Suppress name/port resolutions\n\
@@ -998,15 +1075,15 @@ help(void)
 	\t-x addr[:port]\tSpecify proxy address and port\n\
 	\t-z		Zero-I/O mode [used for scanning]\n\
 	Port numbers can be individual or ranges: lo-hi [inclusive]\n");
-	exit(1);
+	exit(0);
 }

 void
 usage(int ret)
 {
 	fprintf(stderr,
-	    "usage: nc [-46DdhklnrStUuvz] [-I length] [-i interval] [-O length]\n"
-	    "\t  [-P proxy_username] [-p source_port] [-s source] [-T ToS]\n"
+	    "usage: nc [-46DdhjklnrStUuvz] [-I length] [-i interval] [-O length]\n"
+	    "\t  [-P proxy_username] [-p source_port] [-s source] [-T toskeyword]\n"
 	    "\t  [-V rtable] [-w timeout] [-X proxy_protocol]\n"
 	    "\t  [-x proxy_address[:port]] [destination] [port]\n");
 	if (ret)
diff --git a/socks.c b/socks.c
index 71108d5..befd0a9 100644
--- a/socks.c
+++ b/socks.c
@@ -38,7 +38,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <resolv.h>
-#include <readpassphrase.h>
+#include <bsd/readpassphrase.h>
 #include "atomicio.h"

 #define SOCKS_PORT	"1080"
@@ -167,11 +167,11 @@ socks_connect(const char *host, const char *port,
 		buf[2] = SOCKS_NOAUTH;
 		cnt = atomicio(vwrite, proxyfd, buf, 3);
 		if (cnt != 3)
-			err(1, "write failed (%zu/3)", cnt);
+			err(1, "write failed (%zu/3)", (size_t)cnt);

 		cnt = atomicio(read, proxyfd, buf, 2);
 		if (cnt != 2)
-			err(1, "read failed (%zu/3)", cnt);
+			err(1, "read failed (%zu/3)", (size_t)cnt);

 		if (buf[1] == SOCKS_NOMETHOD)
 			errx(1, "authentication method negotiation failed");
@@ -220,23 +220,23 @@ socks_connect(const char *host, const char *port,

 		cnt = atomicio(vwrite, proxyfd, buf, wlen);
 		if (cnt != wlen)
-			err(1, "write failed (%zu/%zu)", cnt, wlen);
+			err(1, "write failed (%zu/%zu)", (size_t)cnt, (size_t)wlen);

 		cnt = atomicio(read, proxyfd, buf, 4);
 		if (cnt != 4)
-			err(1, "read failed (%zu/4)", cnt);
+			err(1, "read failed (%zu/4)", (size_t)cnt);
 		if (buf[1] != 0)
 			errx(1, "connection failed, SOCKS error %d", buf[1]);
 		switch (buf[3]) {
 		case SOCKS_IPV4:
 			cnt = atomicio(read, proxyfd, buf + 4, 6);
 			if (cnt != 6)
-				err(1, "read failed (%d/6)", cnt);
+				err(1, "read failed (%lu/6)", (unsigned long)cnt);
 			break;
 		case SOCKS_IPV6:
 			cnt = atomicio(read, proxyfd, buf + 4, 18);
 			if (cnt != 18)
-				err(1, "read failed (%d/18)", cnt);
+				err(1, "read failed (%lu/18)", (unsigned long)cnt);
 			break;
 		default:
 			errx(1, "connection failed, unsupported address type");
@@ -256,11 +256,11 @@ socks_connect(const char *host, const char *port,

 		cnt = atomicio(vwrite, proxyfd, buf, wlen);
 		if (cnt != wlen)
-			err(1, "write failed (%zu/%zu)", cnt, wlen);
+			err(1, "write failed (%zu/%zu)", (size_t)cnt, (size_t)wlen);

 		cnt = atomicio(read, proxyfd, buf, 8);
 		if (cnt != 8)
-			err(1, "read failed (%zu/8)", cnt);
+			err(1, "read failed (%zu/8)", (size_t)cnt);
 		if (buf[1] != 90)
 			errx(1, "connection failed, SOCKS error %d", buf[1]);
 	} else if (socksv == -1) {
@@ -272,39 +272,39 @@ socks_connect(const char *host, const char *port,

 		/* Try to be sane about numeric IPv6 addresses */
 		if (strchr(host, ':') != NULL) {
-			r = snprintf(buf, sizeof(buf),
+			r = snprintf((char*)buf, sizeof(buf),
 			    "CONNECT [%s]:%d HTTP/1.0\r\n",
 			    host, ntohs(serverport));
 		} else {
-			r = snprintf(buf, sizeof(buf),
+			r = snprintf((char*)buf, sizeof(buf),
 			    "CONNECT %s:%d HTTP/1.0\r\n",
 			    host, ntohs(serverport));
 		}
 		if (r == -1 || (size_t)r >= sizeof(buf))
 			errx(1, "hostname too long");
-		r = strlen(buf);
+		r = strlen((char*)buf);

 		cnt = atomicio(vwrite, proxyfd, buf, r);
 		if (cnt != r)
-			err(1, "write failed (%zu/%d)", cnt, r);
+			err(1, "write failed (%zu/%d)", (size_t)cnt, (int)r);

 		if (authretry > 1) {
 			char resp[1024];

 			proxypass = getproxypass(proxyuser, proxyhost);
-			r = snprintf(buf, sizeof(buf), "%s:%s",
+			r = snprintf((char*)buf, sizeof(buf), "%s:%s",
 			    proxyuser, proxypass);
 			if (r == -1 || (size_t)r >= sizeof(buf) ||
-			    b64_ntop(buf, strlen(buf), resp,
+			    b64_ntop(buf, strlen((char*)buf), resp,
 			    sizeof(resp)) == -1)
 				errx(1, "Proxy username/password too long");
-			r = snprintf(buf, sizeof(buf), "Proxy-Authorization: "
+			r = snprintf((char*)buf, sizeof((char*)buf), "Proxy-Authorization: "
 			    "Basic %s\r\n", resp);
 			if (r == -1 || (size_t)r >= sizeof(buf))
 				errx(1, "Proxy auth response too long");
-			r = strlen(buf);
+			r = strlen((char*)buf);
 			if ((cnt = atomicio(vwrite, proxyfd, buf, r)) != r)
-				err(1, "write failed (%zu/%d)", cnt, r);
+				err(1, "write failed (%zu/%d)", (size_t)cnt, r);
 		}

 		/* Terminate headers */
@@ -312,22 +312,22 @@ socks_connect(const char *host, const char *port,
 			err(1, "write failed (2/%d)", r);

 		/* Read status reply */
-		proxy_read_line(proxyfd, buf, sizeof(buf));
+		proxy_read_line(proxyfd, (char*)buf, sizeof(buf));
 		if (proxyuser != NULL &&
-		    strncmp(buf, "HTTP/1.0 407 ", 12) == 0) {
+		    strncmp((char*)buf, "HTTP/1.0 407 ", 12) == 0) {
 			if (authretry > 1) {
 				fprintf(stderr, "Proxy authentication "
 				    "failed\n");
 			}
 			close(proxyfd);
 			goto again;
-		} else if (strncmp(buf, "HTTP/1.0 200 ", 12) != 0 &&
-		    strncmp(buf, "HTTP/1.1 200 ", 12) != 0)
+		} else if (strncmp((char*)buf, "HTTP/1.0 200 ", 12) != 0 &&
+		    strncmp((char*)buf, "HTTP/1.1 200 ", 12) != 0)
 			errx(1, "Proxy error: \"%s\"", buf);

 		/* Headers continue until we hit an empty line */
 		for (r = 0; r < HTTP_MAXHDRS; r++) {
-			proxy_read_line(proxyfd, buf, sizeof(buf));
+			proxy_read_line(proxyfd, (char*)buf, sizeof(buf));
 			if (*buf == '\0')
 				break;
 		}
--