add very basic proxy support using socks5 client code from niklas@.

ok ericj@.

4 files changed, 204 insertions, 7 deletions

diff --git a/usr.bin/nc/Makefile b/usr.bin/nc/Makefile
index 7f761e17ab3..150f8295bde 100644
--- a/usr.bin/nc/Makefile
+++ b/usr.bin/nc/Makefile
@@ -1,6 +1,6 @@
-#	$OpenBSD: Makefile,v 1.5 2001/06/27 03:13:08 smart Exp $
+#	$OpenBSD: Makefile,v 1.6 2001/09/02 18:45:41 jakob Exp $
 
 PROG=	nc
-SRCS=	netcat.c atomicio.c
+SRCS=	netcat.c atomicio.c socks.c
 
 .include <bsd.prog.mk>
diff --git a/usr.bin/nc/nc.1 b/usr.bin/nc/nc.1
index 53fc6ecfb5a..3025e99c4b9 100644
--- a/usr.bin/nc/nc.1
+++ b/usr.bin/nc/nc.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: nc.1,v 1.18 2001/08/30 16:31:51 krw Exp $
+.\"     $OpenBSD: nc.1,v 1.19 2001/09/02 18:45:41 jakob Exp $
 .\"
 .\" Copyright (c) 1996 David Sacerdote
 .\" All rights reserved.
@@ -37,6 +37,7 @@
 .Op Fl i Ar interval
 .Op Fl p Ar source port
 .Op Fl s Ar source ip address
+.Op Fl x Ar proxy address Op :port
 .Op Fl w Ar timeout
 .Op Ar hostname
 .Op Ar port[s]
@@ -127,6 +128,13 @@ Use UDP instead of the default option of TCP.
 Have
 .Nm
 give more verbose output.
+.It Fl x Ar proxy address Op :port
+Requests that
+.Nm
+should connect to
+.Ar hostname
+using a socks5 proxy at address and port.
+If port is not specified, port 1080 is used.
 .It Fl z
 Specifies that
 .Nm
diff --git a/usr.bin/nc/netcat.c b/usr.bin/nc/netcat.c
index 7bd88ad6818..f2b7c19c4af 100644
--- a/usr.bin/nc/netcat.c
+++ b/usr.bin/nc/netcat.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: netcat.c,v 1.33 2001/08/25 21:50:13 ericj Exp $ */
+/* $OpenBSD: netcat.c,v 1.34 2001/09/02 18:45:41 jakob Exp $ */
 /*
  * Copyright (c) 2001 Eric Jackson <ericj@monkey.org>
  *
@@ -61,6 +61,7 @@ char   *sflag;					/* Source Address */
 int	tflag;					/* Telnet Emulation */
 int	uflag;					/* UDP - Default to TCP */
 int	vflag;					/* Verbosity */
+int	xflag;					/* Socks proxy */
 int	zflag;					/* Port Scan Flag */
 
 int timeout;
@@ -88,6 +89,9 @@ main(argc, argv)
 	struct servent *sv;
 	socklen_t len;
 	struct sockaddr *cliaddr;
+	char *proxy;
+	char *proxyhost, *proxyport;
+	struct addrinfo proxyhints;
 
 	ret = 1;
 	s = 0;
@@ -96,7 +100,7 @@ main(argc, argv)
 	endp = NULL;
 	sv = NULL;
 
-	while ((ch = getopt(argc, argv, "46hi:klnp:rs:tuvw:z")) != -1) {
+	while ((ch = getopt(argc, argv, "46hi:klnp:rs:tuvw:x:z")) != -1) {
 		switch (ch) {
 		case '4':
 			family = AF_INET;
@@ -144,6 +148,10 @@ main(argc, argv)
 			if (timeout < 0 || *endp != '\0')
 				errx(1, "timeout cannot be negative");
 			break;
+		case 'x':
+			xflag = 1;
+			proxy = strdup(optarg);
+			break;
 		case 'z':
 			zflag = 1;
 			break;
@@ -183,6 +191,33 @@ main(argc, argv)
 	if (nflag)
 		hints.ai_flags |= AI_NUMERICHOST;
 
+	if (xflag) {
+		char *tmp;
+
+		if (uflag)
+			errx(1, "no proxy support for UDP mode");
+
+		if (lflag)
+			errx(1, "no proxy support for listen");
+
+		/* XXX IPv6 transport to proxy would probably work */
+		if (family == AF_INET6)
+			errx(1, "no proxy support for IPv6");
+
+		if (sflag)
+			errx(1, "no proxy support for local source address");
+
+		proxyhost = strsep(&proxy, ":");
+		proxyport = proxy;
+
+		memset(&proxyhints, 0, sizeof(struct addrinfo));
+		proxyhints.ai_family = family;
+		proxyhints.ai_socktype = SOCK_STREAM;
+		proxyhints.ai_protocol = IPPROTO_TCP;
+		if (nflag)
+			proxyhints.ai_flags |= AI_NUMERICHOST;
+	}
+
 	if (lflag) {
 		int connfd;
 		ret = 0;
@@ -236,8 +271,14 @@ main(argc, argv)
 			
 			if (s)
 				close(s);
-	
-			if ((s = remote_connect(host, portlist[i], hints)) < 0)
+
+			if (xflag)
+				s = socks_connect(host, portlist[i], hints,
+				    proxyhost, proxyport, proxyhints);
+			else
+				s = remote_connect(host, portlist[i], hints);
+
+			if (s < 0)
 				continue;
 
 			ret = 0;
@@ -326,6 +367,9 @@ remote_connect(host, port, hints)
 
 		if (connect(s, res0->ai_addr, res0->ai_addrlen) == 0)
 			break;
+
+		if (error == 0)
+			break;
 		
 		close(s);
 		s = -1;
@@ -584,6 +628,7 @@ help()
 	\t-u		UDP mode\n\
 	\t-v		Verbose\n\
 	\t-w secs\t	Timeout for connects and final net reads\n\
+	\t-x addr[:port]\tSpecify socks5 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);
diff --git a/usr.bin/nc/socks.c b/usr.bin/nc/socks.c
new file mode 100644
index 00000000000..9189858959d
--- /dev/null
+++ b/usr.bin/nc/socks.c
@@ -0,0 +1,144 @@
+/*	$OpenBSD: socks.c,v 1.1 2001/09/02 18:45:41 jakob Exp $	*/
+
+/*
+ * Copyright (c) 1999 Niklas Hallqvist.  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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Niklas Hallqvist.
+ * 4. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+#include <err.h>
+#include <netdb.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define SOCKS_PORT	"1080"
+#define SOCKS_VERSION	5
+#define SOCKS_NOAUTH	0
+#define SOCKS_NOMETHOD	0xff
+#define SOCKS_CONNECT	1
+#define SOCKS_IPV4	1
+#define SOCKS_MAXCMDSZ	10
+
+static in_addr_t
+decode_addr (const char *s)
+{
+	struct hostent *hp = gethostbyname (s);
+	struct in_addr retval;
+
+	if (hp)
+		return *(in_addr_t *)hp->h_addr_list[0];
+	if (inet_aton (s, &retval))
+		return retval.s_addr;
+	errx (1, "cannot decode address \"%s\"", s);
+}
+
+static in_port_t
+decode_port (const char *s)
+{
+	struct servent *sp;
+	in_port_t port;
+	char *p;
+
+	port = strtol (s, &p, 10);
+	if (s == p) {
+		sp = getservbyname (s, "tcp");
+		if (sp)
+			return sp->s_port;
+	}
+	if (*s != '\0' && *p == '\0')
+		return htons (port);
+	errx (1, "cannot decode port \"%s\"", s);
+}
+
+int
+socks_connect (char *host, char *port, struct addrinfo hints,
+    char *proxyhost, char *proxyport, struct addrinfo proxyhints)
+{
+	char *proxyport_default;
+	int proxyfd;
+	unsigned char buf[SOCKS_MAXCMDSZ];
+	ssize_t cnt;
+	in_addr_t serveraddr;
+	in_port_t serverport;
+
+	if (proxyport)
+		proxyfd = remote_connect(proxyhost, proxyport, proxyhints);
+	else
+		proxyfd = remote_connect(proxyhost, SOCKS_PORT, proxyhints);
+
+	if (!proxyfd)
+		return -1;
+
+	serveraddr = decode_addr (host);
+	serverport = decode_port (port);
+
+	/* Version 5, one method: no authentication */
+	buf[0] = SOCKS_VERSION;
+	buf[1] = 1;
+	buf[2] = SOCKS_NOAUTH;
+	cnt = write (proxyfd, buf, 3);
+	if (cnt == -1)
+		err (1, "write failed");
+	if (cnt != 3)
+		errx (1, "short write, %d (expected 3)", cnt);
+
+	read (proxyfd, buf, 2);
+	if (buf[1] == SOCKS_NOMETHOD)
+		errx (1, "authentication method negotiation failed");
+
+	/* Version 5, connect: IPv4 address */
+	buf[0] = SOCKS_VERSION;
+	buf[1] = SOCKS_CONNECT;
+	buf[2] = 0;
+	buf[3] = SOCKS_IPV4;
+	memcpy (buf + 4, &serveraddr, sizeof serveraddr);
+	memcpy (buf + 8, &serverport, sizeof serverport);
+
+	/* XXX Handle short writes better */
+	cnt = write (proxyfd, buf, 10);
+	if (cnt == -1)
+		err (1, "write failed");
+	if (cnt != 10)
+		errx (1, "short write, %d (expected 10)", cnt);
+
+	/* XXX Handle short reads better */
+	cnt = read (proxyfd, buf, sizeof buf);
+	if (cnt == -1)
+		err (1, "read failed");
+	if (cnt != 10)
+		errx (1, "unexpected reply size %d (expected 10)", cnt);
+	if (buf[1] != 0)
+		errx (1, "connection failed, SOCKS error %d", buf[1]);
+
+	return proxyfd;
+}