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

ok ericj@.

1 files changed, 144 insertions, 0 deletions

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;
+}