- remove from HEAD

[packages/kernel.git] / kernel-pom-ng-rsh.patch

diff -NurpP --minimal linux/include/net/netfilter/nf_conntrack.h linux/include/net/netfilter/nf_conntrack.h
--- linux/include/net/netfilter/nf_conntrack.h	2007-05-30 11:57:00.000000000 +0200
+++ linux/include/net/netfilter/nf_conntrack.h	2007-05-30 11:58:41.000000000 +0200
@@ -29,6 +29,7 @@ union nf_conntrack_expect_proto {
 };
 
 /* Add protocol helper include file here */
+#include <linux/netfilter/nf_conntrack_rsh.h>
 #include <linux/netfilter/nf_conntrack_ftp.h>
 #include <linux/netfilter/nf_conntrack_pptp.h>
 #include <linux/netfilter/nf_conntrack_h323.h>
@@ -39,6 +40,7 @@ union nf_conntrack_expect_proto {
 /* per conntrack: application helper private data */
 union nf_conntrack_help {
 	/* insert conntrack helper private data (master) here */
+	struct nf_ct_rsh_master ct_rsh_info;
 	struct nf_ct_ftp_master ct_ftp_info;
 	struct nf_ct_pptp_master ct_pptp_info;
 	struct nf_ct_h323_master ct_h323_info;
diff -NurpP --minimal linux/include/linux/netfilter/nf_conntrack_rsh.h linux/include/linux/netfilter/nf_conntrack_rsh.h
--- linux/include/linux/netfilter/nf_conntrack_rsh.h	1970-01-01 01:00:00.000000000 +0100
+++ linux/include/linux/netfilter/nf_conntrack_rsh.h	2007-05-30 11:58:41.000000000 +0200
@@ -0,0 +1,28 @@
+/* RSH extension for IP connection tracking, Version 1.0
+ * (C) 2002 by Ian (Larry) Latter <Ian.Latter@mq.edu.au>
+ * based on HW's ip_conntrack_irc.c     
+ *
+ * nf_conntrack_rsh.c,v 1.0 2002/07/17 14:49:26
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ */
+#ifndef _IP_CONNTRACK_RSH_H
+#define _IP_CONNTRACK_RSH_H
+
+#define RSH_PORT	514
+
+/* This structure is per expected connection */
+struct nf_ct_rsh_expect
+{
+	u_int16_t port;
+};
+
+/* This structure exists only once per master */
+struct nf_ct_rsh_master {
+};
+
+#endif /* _IP_CONNTRACK_RSH_H */
+
diff -NurpP --minimal linux/net/ipv4/netfilter/Kconfig linux/net/ipv4/netfilter/Kconfig
--- linux/net/ipv4/netfilter/Kconfig	2007-05-30 11:57:07.000000000 +0200
+++ linux/net/ipv4/netfilter/Kconfig	2007-05-30 11:58:41.000000000 +0200
@@ -870,5 +870,28 @@ config IP_NF_MMS
 	  If you want to compile it as a module, say M here and read
 	  <file:Documentation/modules.txt>.  If unsure, say `Y'.
 
+config NF_CONNTRACK_RSH
+	tristate  'RSH protocol support'
+	depends on NF_CONNTRACK
+	help
+	  The RSH connection tracker is required if the dynamic
+	  stderr "Server to Client" connection is to occur during a
+	  normal RSH session.  This typically operates as follows;
+	
+	    Client 0:1023 --> Server 514    (stream 1 - stdin/stdout)
+	    Client 0:1023 <-- Server 0:1023 (stream 2 - stderr)
+	
+	  This connection tracker will identify new RSH sessions,
+	  extract the outbound session details, and notify netfilter
+	  of pending "related" sessions.
+	
+	  Warning: This module could be dangerous. It is not "best
+	           practice" to use RSH, use SSH in all instances.
+	           (see rfc1244, rfc1948, rfc2179, etc ad-nauseum)
+	
+	
+	  If you want to compile it as a module, say M here and read
+	  <file:Documentation/modules.txt>.  If unsure, say `N'.
+
 endmenu
 
diff -NurpP --minimal linux/net/netfilter/Makefile linux/net/netfilter/Makefile
--- linux/net/netfilter/Makefile	2007-05-30 11:57:07.000000000 +0200
+++ linux/net/netfilter/Makefile	2007-05-30 11:58:41.000000000 +0200
@@ -0,0 +0,1 @@
+obj-$(CONFIG_NF_CONNTRACK_RSH) += nf_conntrack_rsh.o
diff -NurpP --minimal linux/net/netfilter/nf_conntrack_rsh.c linux/net/netfilter/nf_conntrack_rsh.c
--- linux/net/netfilter/nf_conntrack_rsh.c	1970-01-01 01:00:00.000000000 +0100
+++ linux/net/netfilter/nf_conntrack_rsh.c	2007-05-30 11:58:41.000000000 +0200
@@ -0,0 +1,353 @@
+/* RSH extension for IP connection tracking, Version 1.0
+ * (C) 2002 by Ian (Larry) Latter <Ian.Latter@mq.edu.au>
+ * based on HW's ip_conntrack_irc.c	
+ *
+ * (C) 2004,2005 by David Stes <stes@pandora.be>
+ * Modification for Legato NetWorker range [7937-9936] instead of [0:1023]
+ *
+ * (C) 2005 by David Stes <stes@pandora.be>
+ * Upgrade to 2.6.13 API
+ *
+ * ip_conntrack_rsh.c,v 1.0 2002/07/17 14:49:26
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ **
+ *	Module load syntax:
+ * 	insmod ip_conntrack_rsh.o range=1023,ports=port1,port2,...port<MAX_PORTS>
+ *	
+ * 	please give the ports of all RSH servers You wish to connect to.
+ *	If You don't specify ports, the default will be port 514
+ **
+ *      Note to all:
+ *        RSH blows ... you should use SSH (openssh.org) to replace it,
+ *        unfortunately I babysit some sysadmins that won't migrate
+ *	  their legacy crap, in our second tier.
+ */
+
+
+/*
+ *  Some docco ripped from the net to teach me all there is to know about
+ *  RSH, in 16.5 seconds (ie, all of the non-netfilter docco used to write
+ *  this module).
+ *
+ *  I have no idea what "unix rshd man pages" these guys have .. but that
+ *  is some pretty detailed docco!
+ **
+ *
+ *  4. Of the rsh protocol.
+ *  -----------------------
+ * 
+ *   The rshd listens on TCP port #514. The following info is from the unix
+ *   rshd man pages :
+ * 
+ *   "Service Request Protocol
+ * 
+ *    When the rshd daemon receives a service request, it initiates the
+ *    following protocol:
+ * 
+ *     1. The rshd daemon checks the source port number for the request.
+ *        If the port number is not in the range 0 through 1023, the rshd daemon
+ *        terminates the connection.
+ * 
+ *     2. The rshd daemon reads characters from the socket up to a null byte.
+ *        The string read is interpreted as an ASCII number (base 10). If this
+ *        number is nonzero, the rshd daemon interprets it as the port number
+ *        of a secondary stream to be used as standard error. A second connection
+ *        is created to the specified port on the client host. The source port
+ *        on the local host is in the range 0 through 1023.
+ * 
+ *     3. The rshd daemon uses the source address of the initial connection
+ *        request to determine the name of the client host. If the name cannot
+ *        be determined, the rshd daemon uses the dotted decimal representation
+ *        of the client host's address.
+ * 
+ *     4. The rshd daemon retrieves the following information from the initial
+ *        socket:
+ * 
+ *         * A null-terminated string of at most 16 bytes interpreted as
+ *           the user name of the user on the client host.
+ * 
+ *         * A null-terminated string of at most 16 bytes interpreted as
+ *           the user name to be used on the local server host.
+ * 
+ *         * Another null-terminated string interpreted as a command line
+ *           to be passed to a shell on the local server host.
+ * 
+ *     5. The rshd daemon attempts to validate the user using the following steps:
+ * 
+ *         a. The rshd daemon looks up the local user name in the /etc/passwd
+ *            file and tries to switch to the home directory (using the chdir
+ *            subroutine). If either the lookup or the directory change fails,
+ *            the rshd daemon terminates the connection.
+ * 
+ *         b. If the local user ID is a nonzero value, the rshd daemon searches
+ *            the /etc/hosts.equiv file to see if the name of the client
+ *            workstation is listed. If the client workstation is listed as an
+ *            equivalent host, the rshd daemon validates the user.
+ * 
+ *         c. If the $HOME/.rhosts file exists, the rshd daemon tries to
+ *            authenticate the user by checking the .rhosts file.
+ * 
+ *         d. If either the $HOME/.rhosts authentication fails or the
+ *            client host is not an equivalent host, the rshd daemon
+ *            terminates the connection.
+ * 
+ *     6. Once rshd validates the user, the rshd daemon returns a null byte
+ *        on the initial connection and passes the command line to the user's
+ *        local login shell. The shell then inherits the network connections
+ *        established by the rshd daemon."
+ * 
+ */
+
+
+#include <linux/module.h>
+#include <linux/netfilter.h>
+#include <linux/ip.h>
+#include <net/checksum.h>
+#include <net/tcp.h>
+
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <net/netfilter/nf_conntrack_expect.h>
+#include <net/netfilter/nf_conntrack_helper.h>
+#include <linux/netfilter/nf_conntrack_rsh.h>
+
+#define MAX_PORTS 8
+static int range; /* defaults to = 1023 */
+static unsigned short rangemask; /* defaults to = 0xfc00 */
+static int ports[MAX_PORTS];
+static int ports_n_c = 0;
+
+MODULE_AUTHOR("Ian (Larry) Latter <Ian.Latter@mq.edu.au>");
+MODULE_DESCRIPTION("RSH connection tracking module");
+MODULE_LICENSE("GPL");
+#ifdef MODULE_PARM
+module_param(range, int, 0400);
+MODULE_PARM_DESC(range, "max port of reserved range (default is 1023)");
+module_param_array(ports, int, &ports_n_c, 0400);
+MODULE_PARM_DESC(ports, "port numbers of RSH servers");
+#endif
+
+static DEFINE_SPINLOCK(rsh_buffer_lock);
+static char rsh_buffer[65535];
+
+unsigned int (*ip_nat_rsh_hook)(struct sk_buff **pskb,
+				enum ip_conntrack_info ctinfo,
+				unsigned int matchoff,
+				struct nf_conntrack_expect *exp);
+
+#define PRINTK(format, args...) printk(KERN_DEBUG "ip_conntrack_rsh: " \
+					format, ## args)
+
+#if 0
+#define DEBUGP(format, args...) printk(KERN_DEBUG "ip_conntrack_rsh: " \
+					format, ## args)
+#else
+#define DEBUGP(format, args...)
+#endif
+
+
+/* FIXME: This should be in userspace.  Later. */
+static int help(struct sk_buff **pskb,
+		struct nf_conn *ct, enum ip_conntrack_info ctinfo)
+{
+	struct tcphdr _tcph, *th;
+	char *data, *rb_ptr;
+	int ret = NF_ACCEPT;
+	int dir = CTINFO2DIR(ctinfo);
+        struct nf_conntrack_expect *exp;
+	unsigned int dataoff, datalen;
+	u_int16_t port;
+	int maxoctet = 4;
+
+	/*  note that "maxoctet" is used to maintain sanity (8 was the
+ 	 *  original array size used in rshd/glibc) -- is there a
+	 *  vulnerability in rshd.c in the looped port *= 10?
+ 	 */
+
+	DEBUGP("entered\n");
+
+	/* bail if packet is not from RSH client */
+	if (dir == IP_CT_DIR_REPLY) {
+		return NF_ACCEPT; 
+	}
+
+	/* Until there's been traffic both ways, don't look in packets. */
+	if (ctinfo != IP_CT_ESTABLISHED
+	    && ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) {
+		DEBUGP("Conntrackinfo = %u\n", ctinfo);
+		return NF_ACCEPT;
+	}
+
+	/* Not a full tcp header? */
+	th = skb_header_pointer(*pskb, ip_hdr(*pskb)->ihl*4,
+				sizeof(_tcph), &_tcph);
+	if (!th) {
+		DEBUGP("rsh: skb_header_pointer null\n");
+		return NF_ACCEPT;
+	}
+
+	/* No data? */
+	dataoff = ip_hdr(*pskb)->ihl*4 + th->doff*4;
+	if (dataoff >= (*pskb)->len) {
+		return NF_ACCEPT;
+	}
+	datalen = (*pskb)->len - dataoff;
+	spin_lock_bh(&rsh_buffer_lock);
+	rb_ptr = skb_header_pointer(*pskb, dataoff, datalen, rsh_buffer);
+	BUG_ON(rb_ptr == NULL);
+	data = rb_ptr;
+
+	DEBUGP("rsh: find rsh stderr port datalen %u\n",datalen);
+
+	maxoctet = 5;
+	port = 0;
+	for ( ; *data != 0 && maxoctet != 0; data++, maxoctet--) {
+		if (*data < 0) {
+			ret = 1; goto out;
+		}
+		if (*data == 0) {
+			break;
+		}
+		if (*data < 48 || *data > 57) {
+			DEBUGP("these aren't the packets you're looking for ..\n");
+			ret = NF_ACCEPT; goto out;
+		}
+	        port = port * 10 + ( *data - 48 );
+	}
+
+	/* dont relate sessions that try to expose the client */
+	if (port == 0) {
+           DEBUGP("skipping, port is 0!\n");
+	   ret = NF_ACCEPT;goto out;
+	}
+
+	DEBUGP("found port %u\n", port);
+	if (port > range) {
+		DEBUGP("skipping, expected port size is greater than range!\n");
+		return NF_ACCEPT;
+	}
+
+	exp = nf_ct_expect_alloc(ct);
+	if (!exp) {
+		ret = NF_DROP;
+		goto out;
+	}
+
+	/*  new(,related) connection is;
+	 *          reply + dst (uint)port + src port (0:1023)
+	 */
+
+	/* Watch out, Radioactive-Man! */
+	exp->tuple.src.u3.ip = ct->tuplehash[!dir].tuple.src.u3.ip;
+	exp->tuple.dst.u3.ip = ct->tuplehash[!dir].tuple.dst.u3.ip;
+	exp->tuple.src.u.tcp.port = 0;
+	exp->tuple.dst.u.tcp.port = htons(port);
+	exp->tuple.dst.protonum = IPPROTO_TCP;
+
+	exp->mask.src.u3.ip = 0xffffffff;
+
+	exp->mask.src.u.tcp.port = htons(rangemask);
+
+	exp->expectfn = NULL;
+	exp->master = ct;
+
+	DEBUGP("expect related ip   %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
+		NIPQUAD(exp->tuple.src.ip),
+		ntohs(exp->tuple.src.u.tcp.port),
+		NIPQUAD(exp->tuple.dst.ip),
+		ntohs(exp->tuple.dst.u.tcp.port));
+
+	if (ip_nat_rsh_hook)
+		ret = ip_nat_rsh_hook(pskb, ctinfo, rb_ptr - data, exp);
+	else if (nf_ct_expect_related(exp) != 0) {
+		ret = NF_DROP;
+	}
+
+	nf_ct_expect_put(exp);
+
+out:
+	spin_unlock_bh(&rsh_buffer_lock);
+	return ret;
+}
+
+static struct nf_conntrack_helper rsh_helpers[MAX_PORTS];
+static char rsh_names[MAX_PORTS][10];
+static const struct nf_conntrack_expect_policy rsh_exp_policy = {
+	.max_expected      = 1,
+	.timeout      = 5, /* stes bug timeout=0 */
+};
+
+static void fini(void);
+
+static int __init init(void)
+{
+	int port, ret;
+	char *tmpname;
+
+	/* If no port given, default to standard RSH port */
+	if (ports[0] == 0)
+		ports[0] = RSH_PORT;
+
+	/* the check on reserved port <1023 doesn't work with Legato */
+        /* for Legato NetWorker, the check should be that port <= 9936 */ 
+
+        if (range == 0) 
+		range = 1023;
+
+	/* Legato uses range [ 7937 : 9936 ] -> 7937 by default */
+
+        rangemask = 0xffff ^ range; /* defaults to = 0xfc00 */
+
+	for (port = 0; (port < MAX_PORTS) && ports[port]; port++) {
+		memset(&rsh_helpers[port], 0, sizeof(struct nf_conntrack_helper));
+
+		tmpname = &rsh_names[port][0];
+		if (ports[port] == RSH_PORT)
+			sprintf(tmpname, "rsh");
+		else
+			sprintf(tmpname, "rsh-%d", ports[port]);
+		rsh_helpers[port].name = tmpname;
+
+		rsh_helpers[port].me = THIS_MODULE;
+		rsh_helpers[port].expect_policy = &rsh_exp_policy;
+
+		rsh_helpers[port].tuple.dst.protonum = IPPROTO_TCP;
+
+		/* RSH must come from ports 0:1023 to ports[port] (514) */
+		rsh_helpers[port].tuple.src.u.tcp.port = htons(ports[port]);
+
+		rsh_helpers[port].help = help;
+
+		PRINTK("registering helper for port #%d: %d/TCP\n", port, ports[port]);
+		PRINTK("helper match ip   %u.%u.%u.%u:%u-%u.%u.%u.%u:%u\n",
+			NIPQUAD(rsh_helpers[port].tuple.src.u3.ip),
+			ntohs(rsh_helpers[port].tuple.src.u.tcp.port),
+			NIPQUAD(rsh_helpers[port].tuple.dst.u3.ip),
+			ntohs(rsh_helpers[port].tuple.dst.u.tcp.port));
+
+		ret = nf_conntrack_helper_register(&rsh_helpers[port]);
+
+		if (ret) {
+			printk("ERROR registering port %d\n",
+				ports[port]);
+			fini();
+			return -EBUSY;
+		}
+		ports_n_c++;
+	}
+	return 0;
+}
+
+/* This function is intentionally _NOT_ defined as __exit, because 
+ * it is needed by the init function */
+static void fini(void)
+{
+	int port;
+	for (port = 0; (port < MAX_PORTS) && ports[port]; port++) {
+		DEBUGP("unregistering port %d\n", ports[port]);
+		nf_conntrack_helper_unregister(&rsh_helpers[port]);
+	}
+}
+
+module_init(init);
+module_exit(fini);