From: Sapan Bhatia <gwsapan@gmail.com>
Date: Tue, 5 Jun 2012 07:01:50 +0000 (-0400)
Subject: First checkin of the transforward module for port forwarding
X-Git-Tag: transforward-0.1-1~2
X-Git-Url: http://git.onelab.eu/?p=transforward.git;a=commitdiff_plain;h=71b2cf441369c34aff3033d39e1c79e27bc39eb4

First checkin of the transforward module for port forwarding
---

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..2965572
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,7 @@
+obj-m += transforward.o
+
+all:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+
+clean:
+	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
diff --git a/bind b/bind
new file mode 100755
index 0000000..f0ce0e5
--- /dev/null
+++ b/bind
@@ -0,0 +1,14 @@
+import socket
+
+host = '128.112.95.146'                 
+port = 13412
+s = socket.socket()
+print s.bind((host,port))
+s.listen(10)
+conn, addr = s.accept()
+print 'Connected by', addr
+while 1:
+    data = conn.recv(1024)
+    if not data: break
+    conn.send(data)
+conn.close()
diff --git a/transforward.c b/transforward.c
new file mode 100644
index 0000000..da61cee
--- /dev/null
+++ b/transforward.c
@@ -0,0 +1,105 @@
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/fs_struct.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+#include <linux/proc_fs.h>
+#include <asm/uaccess.h>
+#include <linux/sysrq.h>
+#include <linux/timer.h>
+#include <linux/time.h>
+#include <linux/lglock.h>
+#include <linux/init.h>
+#include <linux/idr.h>
+#include <linux/namei.h>
+#include <linux/bitops.h>
+#include <linux/mount.h>
+#include <linux/dcache.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/sched.h>
+#include <linux/seq_file.h>
+#include <linux/kprobes.h>
+#include <linux/kallsyms.h>
+#include <linux/nsproxy.h>
+#include <net/sock.h>
+#include <linux/inetdevice.h>
+
+#define VERSION_STR "0.0.1"
+
+#ifndef CONFIG_X86_64
+#error "This code does not support your architecture"
+#endif
+
+MODULE_AUTHOR("Sapan Bhatia <sapanb@cs.princeton.edu>");
+MODULE_DESCRIPTION("Transparent port forwarding for LXC.");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(VERSION_STR);
+
+static int address_in_root(unsigned int haddr) {
+    printk(KERN_CRIT "In address_in_root: %d",haddr);
+    struct net_device *dev;
+    struct net *net = &init_net;
+
+    for_each_netdev(net, dev) {
+            unsigned int ifhaddr = inet_select_addr(dev,0,0);
+            printk(KERN_CRIT "Checking address: %d",ifhaddr);
+            if (haddr == ifhaddr) return 1;
+    }
+    return 0;
+}
+
+static int inet_bind_entry(struct socket *sock, struct sockaddr *uaddr, int addr_len) {
+    struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
+    unsigned int snum = ntohs(addr->sin_addr.s_addr);
+    if (address_in_root(snum)) {
+        put_net(sock_net(sock->sk));
+        sock_net_set(sock->sk, get_net(&init_net)); 
+        printk(KERN_CRIT "Rewiring netns");
+    }
+    jprobe_return();
+    return 0;
+}
+
+
+static struct jprobe net_probe = {
+	.entry = (kprobe_opcode_t *) inet_bind_entry
+};
+
+
+static void __exit transforward_exit(void)
+{
+	unregister_jprobe(&net_probe);
+	printk("Transforward: Stopped transforward.\n");
+}
+
+
+
+static int __init transforward_init(void)
+{
+    int ret = 0;
+	printk("Transforward: starting transforward version %s.\n",
+	       VERSION_STR);
+          net_probe.kp.addr = 
+                  (kprobe_opcode_t *) kallsyms_lookup_name("inet_bind");
+          if (!net_probe.kp.addr) {
+                  printk("Couldn't find %s to plant kretprobe\n", "inet_bind");
+                  return -1;
+          }
+  
+          if ((ret = register_jprobe(&net_probe)) <0) {
+                  printk("register_jprobe failed, returned %d\n", ret);
+                  return -1;
+          }
+          printk("Planted jprobe at %p, handler addr %p\n",
+                 net_probe.kp.addr, net_probe.entry);
+
+        return ret;
+}
+
+module_init(transforward_init);
+module_exit(transforward_exit);
diff --git a/transforward.spec b/transforward.spec
new file mode 100644
index 0000000..ac0d0d4
--- /dev/null
+++ b/transforward.spec
@@ -0,0 +1,46 @@
+%define url $URL$
+
+%define name transforward
+%define version 0.1
+%define taglevel 1
+
+%define release %{taglevel}%{?pldistro:.%{pldistro}}%{?date:.%{date}}
+
+Vendor: PlanetLab
+Packager: PlanetLab Central <support@planet-lab.org>
+Distribution: PlanetLab %{plrelease}
+URL: %(echo %{url} | cut -d ' ' -f 2)
+
+Summary: Kernel module that transparently forwards ports between containers
+Name: %{name}
+Version: %{version}
+Release: %{release}
+License: GPL
+Group: System Environment/Kernel
+BuildRoot: %{_tmppath}/%{name}-%{version}-%{release}-buildroot
+Source0: transforward-%{version}.tar.gz
+
+%description
+Kernel module that transparently forwards ports between containers
+
+%prep 
+%setup -q
+
+%build
+make -C /lib/modules/`ls /lib/modules | head -1`/build M=$PWD modules
+
+%install
+mkdir -p $RPM_BUILD_ROOT/lib/modules/`ls /lib/modules | head -1`/kernel/net/transforward
+cp transforward.ko $RPM_BUILD_ROOT/lib/modules/`ls /lib/modules | head -1`/kernel/net/transforward
+
+%clean
+rm -rf $RPM_BUILD_ROOT
+
+%files
+/lib
+
+%post
+
+%postun
+
+%changelog