Initial release to be continued (echo, frag reassembly, etc)

git-svn-id: http://svn.eurecom.fr/openair4G/trunk@6052 818b1a75-f10b-46b9-bf7c-635c3b92a50f

openair-cn/GTPV1-U/GTPUAH/INSTALL

+How to build
+------------
+
+1. Extract the files in a location of your choice. The
+   Files will be extracted in a directory called gtpu.
+
+2. cd <gtpu_dir>/gtpu. 
+
+3. make
+
+If make is successful, the binary files (libxt_GTPU.so and xt_GTPU.ko) 
+will be created in the Bin folder.
+
+
+How to install
+--------------
+There is no "make install" as that will be difficult to support all
+possible Linux distro. The cmd.sh file demonstrates how to install
+the two binary files in the system.
+
+
+In case of problem:
+ - check you got the last release of the library (see README),
+ - contact the mailing list (see README),
+ - check the bugtracker for known bugs (see README).
+
+
+Documentation
+-------------
+Please have a look at the "Architecture" section in the README.
+
+
+

openair-cn/GTPV1-U/GTPUAH/Makefile

+####################################################################################
+# Makefile for iptables extension for the GTPUAH target and GTPUAH klm
+#
+# Copyright (c) 2010-2011 Polaris Networks
+# Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+####################################################################################
+
+export BIN_DIR ?= $(shell pwd)/Bin
+KVERSION = $(shell uname -r)
+KVERSION_LAST_DIGIT = $(shell echo ${KVERSION} | cut -d "." -f 3 | cut -d "-" -f 1)
+
+obj-m = xt_GTPUAH.o
+EXTRA_CFLAGS += -DKVERSION=$(KVERSION_LAST_DIGIT)
+
+all: xtlib
+	echo "Building for Kernel Version: $(KVERSION_LAST_DIGIT)"
+	make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
+	mv xt_GTPUAH.ko $(BIN_DIR)/
+
+clean: libclean
+	make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean
+
+################################################################################
+# The next section is used by libxt_GTPUAH
+################################################################################
+
+XT_IPTABLES_VERSION = $(shell /sbin/iptables -V | cut -d " " -f 2 | cut -b 2-)
+IPT_FIRST_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 1 | cut -d "-" -f 1)
+IPT_SECOND_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 2 | cut -d "-" -f 1)
+IPT_THIRD_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 3 | cut -d "-" -f 1)
+IPTVERSION = $(IPT_FIRST_NUM)$(IPT_SECOND_NUM)$(IPT_THIRD_NUM)
+IPTABLES_VERSION_STRING = \"$(IPT_FIRST_NUM).$(IPT_SECOND_NUM).$(IPT_THIRD_NUM)\"
+
+LIB_CC := gcc
+
+ifeq ($(IPTVERSION), 135)
+    LIB_LD := ld 
+else
+    LIB_LD := gcc 
+endif
+
+LIB_CFLAGS := -fPIC -Wall -MMD -D_LARGEFILE_SOURCE=1 -D_LARGE_FILES -D_FILE_OFFSET_BITS=64 \
+          -D_REENTRANT -pipe -DXTABLES_LIBDIR=\"/usr/local/libexec/xtables\" -DXTABLES_INTERNAL \
+          -D_INIT=libxt_GTPUAH_init -DPIC -fPIC -O2 \
+          -DIPTVERSION=$(IPTVERSION) \
+          -DIPTABLES_VERSION_STRING=$(IPTABLES_VERSION_STRING)
+
+XT_TARGET := xt_GTPUAH
+XT_LIBNAME := lib$(XT_TARGET).so
+XT_BUILD_DIR = $(BIN_DIR)/$(XT_TARGET)
+
+# Get the system distribution type
+IsDebian=$(shell /bin/cat /proc/version | grep -i -e ubuntu -e debian)
+IsRedHat=$(shell /bin/cat /proc/version | grep -i -e centos -e "red hat" -e suse -e fedora) 
+
+# Change the ipq library name for 64-bit Debian-based distributions
+ifeq ($(X86_64),x86_64)
+    ifneq ($(strip $(IsDebian)),)
+        LIB_IPQ=_pic
+    endif
+endif
+
+INCLUDE_DIR = -I. \
+              -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include \
+              -I/usr/lib64/glib-2.0/include
+
+XT_SOURCES = libxt_GTPUAH.c
+
+XT_OBJECTS := $(addprefix $(XT_BUILD_DIR)/, $(notdir $(XT_SOURCES:.c=.o)))
+
+xtlib: XT
+
+XT: DF = $(XT_BUILD_DIR)/$(*F)
+XT: $(XT_BUILD_DIR) $(BIN_DIR)/$(XT_LIBNAME)
+
+-include $(addprefix $(XT_BUILD_DIR)/, $(notdir $(XT_SOURCES:.c=.P)))
+
+$(XT_BUILD_DIR):
+	@echo Build Directory is $@
+	@if [ ! -d $(BIN_DIR) ]; then mkdir $(BIN_DIR); fi
+	@if [ ! -d $@ ]; then mkdir $@; fi
+
+$(BIN_DIR)/$(XT_LIBNAME): $(XT_OBJECTS)
+	@echo Linking $@
+	@$(LIB_LD) -shared $(XT_OBJECTS) -o $@
+
+$(XT_BUILD_DIR)/%.o : %.c
+	@echo "Building GTPUAH ext for version $(IPTVERSION) $(IPTABLES_VERSION_STRING)"
+	@echo Compiling $<
+	@$(LIB_CC) $(LIB_CFLAGS) -MF $(DF).d $(INCLUDE_DIR) -o $@ -c $<
+	@cp $(DF).d $(DF).P; \
+	sed -e 's/#.*//' -e 's/^[^:]*: *//' -e 's/ *\\$$//' \
+		-e '/^$$/ d' -e 's/$$/ :/' < $(DF).d >> $(DF).P; \
+	rm -f $(DF).d
+
+libclean:
+	@rm -rf $(BIN_DIR)/$(XT_LIBNAME) $(XT_BUILD_DIR)
+

openair-cn/GTPV1-U/GTPUAH/README

+Introduction
+------------
+This piece of software implementes GPRS Tunneling Protocol (GTP) for user plane.
+The software has two components - one is the extension of iptables that
+run in user-space. The other is the counterpart of the iptables extension
+that runs in kernel space.
+
+
+License
+-------
+The project is licensed under GPL2+, see the COPYING and AUTHORS files for more
+details.
+
+
+Architecture
+------------
+The GTPu tunneling is handled in two parts. The first part is the user-space 
+iptables target extension library (let's call it libxt). The second
+part is the GTPu kernel loadable module (let's call it gtpu). The way it 
+is, once the user configures a GTPu tunnel attributes using iptables, the klm
+is loaded by the kernel automatically and handles the IP packets according to
+the GTPu tunnel attributes set by the user. 
+
+The user can set the action to be taken on a matching IP packet. The action can be
+either of "add", "remove" or "transport" .
+
+A GTPu tunnel has the following attributes:
+  - own IP address
+  - own GTPu tunnel id
+  - peer's IP address
+  - peer's GTPu tunnel id
+
+The GTPU target is designed to work only on mangle table. Also, the user is 
+expected to add GTPU target to the PREROUTING chain, as the GTPU target will
+modify the original IP packet before it is routed.
+
+Once the user creates the rule in iptables, the matching IP packets go through 
+the gtpu klm, which acts upon the IP packet according to the action set by the
+user. The action "Add" means the klm will add a GTPu header to the IP packet.
+"Remove" will remove the GTPu header from the IP packet and "Transport" will
+do a Remove first followed by an "Add" on the IP packet.
+
+For example, consider the following command:
+
+iptables -t mangle -A PREROUTING -d 10.10.10.1 -j GTPU --own-ip 192.168.0.98 --own-tun 100 --peer-ip 192.168.0.109 --peer-tun 101 --action add
+
+This command will configure the system to add a GTPu header to any IP packet destined to 10.10.10.1. 
+The source IP address outer IP will be 192.168.0.109, the dest IP will be 192.168.0.98 and
+the destination GTP tunnel id will be 101.
+
+Similarly, consider the following command:
+
+iptables -t mangle -A PREROUTING -s 192.168.0.109 -d 192.168.0.98 -p udp --dport 2152 -j GTPU --action remove
+
+This command will process all the GTPu packets coming from 192.168.0.109 to 192.168.0.98 to
+strip the GTPu header and forward the inner IP packet to the kernel's routing engine.
+
+
+Files
+---------
+There are two source C files and one header file:
+ - libxt_GTPU.c  : source file for iptables GTPU extension library (libxt)
+ - xt_GTPU.c     : source file for gtpu kernel loadable module (klm)
+ - xt_GTPU.h     : common header file, shared between the libxt and the klm
+ - Makefile      : Makefile to build both the libxt and the klm
+ - cmd.sh        : sample cmd file to show how the binaries can be used
+
+See the INSTALL file to learn how to build the binaries.
+
+
+References
+----------
+3GPP TS 29.281      General Packet Radio System (GPRS)
+                    Tunnelling Protocol User Plane (GTP-u)
+
+
+Authors
+-------
+Pradip Biswas <pradip_biswas@polarisnetworks.net>
+

openair-cn/GTPV1-U/GTPUAH/RELEASE_NOTES

+
+Known issues in GTPU v1.0
+-------------------------
+
+1. Does not implement the "Transport" action.
+2. Does not handle segmented GTPu packets.
+

openair-cn/GTPV1-U/GTPUAH/cmd.sh

+# Clear the iptables mangle table
+iptables -t mangle -F
+
+# Remove GTPU KLM
+rmmod xt_GTPUAH
+
+# Insert the GTPUAH KLM
+insmod ./Bin/xt_GTPUAH.ko
+
+# Copy the userland iptables extenstion library
+if [ -d /lib/xtables ]; then
+    /bin/cp -f ./Bin/libxt_GTPUAH.so /lib/xtables/
+fi
+
+if [ -d /lib/iptables ]; then
+    /bin/cp -f ./Bin/libxt_GTPUAH.so /lib/iptables/libipt_GTPUAH.so
+fi
+

openair-cn/GTPV1-U/GTPUAH/libxt_GTPUAH.c

+/* Shared library add-on to iptables for the GTPUAH target
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <linux/netfilter.h>
+
+#include "xt_GTPUAH.h"
+
+#if (IPTVERSION <= 135)
+#include <iptables.h>
+#elif (IPTVERSION > 135)
+#include <xtables.h>
+#endif
+
+#if (IPTVERSION <= 135)
+#define GTPUAH_PARAM_BAD_VALUE 0
+#define GTPUAH_PARAM_ONLY_ONCE 1
+#define XT_GTPUAH_VERSION IPTABLES_VERSION_STRING
+#define gtpuah_strtoui(s,v,m,M) !string_to_number(s,m,M,v)
+#define gtpuah_exit_error exit_error
+#elif (IPTVERSION > 135) && (IPTVERSION <= 141) 
+#define GTPUAH_PARAM_BAD_VALUE P_BAD_VALUE
+#define GTPUAH_PARAM_ONLY_ONCE P_ONLY_ONCE
+#define XT_GTPUAH_VERSION XTABLES_VERSION
+#define gtpuah_param_act param_act
+#define gtpuah_strtoui(s,v,m,M) !string_to_number(s,m,M,v)
+#define gtpuah_exit_error exit_error
+#elif (IPTVERSION > 141)
+#define GTPUAH_PARAM_BAD_VALUE XTF_BAD_VALUE
+#define GTPUAH_PARAM_ONLY_ONCE XTF_ONLY_ONCE
+#define XT_GTPUAH_VERSION XTABLES_VERSION
+#define gtpuah_param_act xtables_param_act
+#define gtpuah_strtoui(s,v,m,M) xtables_strtoui(s,NULL,v,m,M)
+#define gtpuah_exit_error xtables_error
+#endif
+
+enum {
+    PARAM_LADDR = 1 << 0,
+    PARAM_LTUN = 1 << 1,
+    PARAM_RADDR = 1 << 2,
+    PARAM_RTUN = 1 << 3,
+    PARAM_ACTION = 1 << 4,
+};
+
+static void GTPUAH_help(void)
+{
+    printf(
+"GTPUAH target options\n"
+"  --action         value        Set action <value: add>\n"
+"  --own-ip         value        Set own IP address\n"
+"  --own-tun        value        Set own tunnel id <value: 1-2^31>\n"
+"  --peer-ip        value        Set peer IP address\n"
+"  --peer-tun       value        Set peer tunnel id <value: 1-2^31>\n");
+}
+
+#if (IPTVERSION <= 135)
+/* Stolen from iptables v1.4.7 code */
+void gtpuah_param_act(unsigned int status, const char *p1, ...)
+{
+        const char *p2, *p3;
+        va_list args;
+        int b;
+
+        va_start(args, p1);
+
+        switch (status) {
+        case GTPUAH_PARAM_ONLY_ONCE:
+                p2 = va_arg(args, const char *);
+                b  = va_arg(args, unsigned int);
+                if (!b)
+                        return;
+                exit_error(PARAMETER_PROBLEM,
+                           "%s: \"%s\" option may only be specified once",
+                           p1, p2);
+                break;
+        case GTPUAH_PARAM_BAD_VALUE:
+                p2 = va_arg(args, const char *);
+                p3 = va_arg(args, const char *);
+                exit_error(PARAMETER_PROBLEM,
+                           "%s: Bad value for \"%s\" option: \"%s\"",
+                           p1, p2, p3);
+                break;
+        default:
+                exit_error(status, "%s", "Unknown error");
+                break;
+        }
+
+        va_end(args);
+}
+
+#endif
+
+static void parse_gtpuah_addr(const char *s, struct xt_gtpuah_target_info *info, int flag)
+{
+    in_addr_t addr;
+
+    if ((addr = inet_addr(s)) == -1)
+    {
+        switch (flag)
+        {
+            case PARAM_LADDR:
+                gtpuah_param_act(GTPUAH_PARAM_BAD_VALUE, "GTPUAH", "--own-ip", s);
+                break;
+            case PARAM_RADDR:
+                gtpuah_param_act(GTPUAH_PARAM_BAD_VALUE, "GTPUAH", "--peer-ip", s);
+                break;
+        }
+    }
+     
+    switch (flag)
+    {
+        case PARAM_LADDR:
+            info->laddr = addr;
+            break;
+        case PARAM_RADDR:
+            info->raddr = addr;
+            break;
+    }
+}
+
+static void parse_gtpuah_tunid(char *s, struct xt_gtpuah_target_info *info, int flag)
+{
+    unsigned int value;
+
+    if (!gtpuah_strtoui(s, &value, 0, UINT32_MAX))
+    {
+        switch (flag)
+        {
+            case PARAM_LTUN:
+                gtpuah_param_act(GTPUAH_PARAM_BAD_VALUE, "GTPUAH", "--own-tun", s);
+                break;
+            case PARAM_RTUN:
+                gtpuah_param_act(GTPUAH_PARAM_BAD_VALUE, "GTPUAH", "--peer-tun", s);
+                break;
+        }
+    }
+
+    switch (flag)
+    {
+        case PARAM_LTUN:
+            info->ltun = value;
+            break;
+        case PARAM_RTUN:
+            info->rtun = value;
+            break;
+    }
+}
+
+static void parse_gtpuah_action(char *s, struct xt_gtpuah_target_info *info, unsigned int *flags)
+{
+    if (!strcmp(s, "add"))
+    {
+        info->action = PARAM_GTPUAH_ACTION_ADD;
+        *flags |= PARAM_GTPUAH_ACTION_ADD;
+    }
+    else
+    {
+        gtpuah_param_act(GTPUAH_PARAM_BAD_VALUE, "GTPUAH", "--action", s);
+    }
+}
+
+#if (IPTVERSION <= 135)
+static int
+GTPUAH_parse(int c, char **argv, int invert, unsigned int *flags,
+           const struct ipt_entry *entry,
+           struct ipt_entry_target **target)
+#else
+static int
+GTPUAH_parse(int c, char **argv, int invert, unsigned int *flags,
+           const void *entry, struct xt_entry_target **target)
+#endif
+{
+    struct xt_gtpuah_target_info *info = (struct xt_gtpuah_target_info *) (*target)->data;
+
+    switch (c) 
+    {
+        case '1':
+                gtpuah_param_act(GTPUAH_PARAM_ONLY_ONCE, "GTPUAH", "--own-ip", *flags & PARAM_LADDR);
+                parse_gtpuah_addr(optarg, info, PARAM_LADDR);
+                *flags |= PARAM_LADDR;
+                return 1;
+        case '2':
+                gtpuah_param_act(GTPUAH_PARAM_ONLY_ONCE, "GTPUAH", "--own-tun", *flags & PARAM_LTUN);
+                parse_gtpuah_tunid(optarg, info, PARAM_LTUN);
+                *flags |= PARAM_LTUN;
+                return 1;
+        case '3':
+                gtpuah_param_act(GTPUAH_PARAM_ONLY_ONCE, "GTPUAH", "--peer-ip", *flags & PARAM_RADDR);
+                parse_gtpuah_addr(optarg, info, PARAM_RADDR);
+                *flags |= PARAM_RADDR;
+                return 1;
+        case '4':
+                gtpuah_param_act(GTPUAH_PARAM_ONLY_ONCE, "GTPUAH", "--peer-tun", *flags & PARAM_RTUN);
+                parse_gtpuah_tunid(optarg, info, PARAM_RTUN);
+                *flags |= PARAM_RTUN;
+                return 1;
+        case '5':
+                gtpuah_param_act(GTPUAH_PARAM_ONLY_ONCE, "GTPUAH", "--action", *flags & PARAM_ACTION);
+                parse_gtpuah_action(optarg, info, flags);
+                *flags |= PARAM_ACTION;
+                return 1;
+    }
+
+    return 1;
+}
+
+static void GTPUAH_check(unsigned int flags)
+{
+    if (!(flags & PARAM_ACTION))
+    {
+        gtpuah_exit_error(PARAMETER_PROBLEM, "GTPUAH: You must specify action");
+    }
+    
+    if (!(flags & PARAM_LADDR))
+    {
+        gtpuah_exit_error(PARAMETER_PROBLEM, "GTPUAH: You must specify local addr");
+    }
+    if (!(flags & PARAM_LTUN))
+    {
+        gtpuah_exit_error(PARAMETER_PROBLEM, "GTPUAH: You must specify local tunnel id");
+    }
+    if (!(flags & PARAM_RADDR))
+    {
+        gtpuah_exit_error(PARAMETER_PROBLEM, "GTPUAH: You must specify remote addr");
+    }
+    if (!(flags & PARAM_RTUN))
+    {
+        gtpuah_exit_error(PARAMETER_PROBLEM, "GTPUAH: You must specify remote tunnel id");
+    }
+}
+
+static void convert_action_to_string(int action, char *actionstr)
+{
+    switch(action)
+    {
+        case PARAM_GTPUAH_ACTION_ADD:
+            sprintf (actionstr, "add");
+            break;
+        default :
+            sprintf (actionstr, "unspecified!!!");
+            break;
+    }
+}
+
+#if (IPTVERSION <= 135)
+static void
+GTPUAH_print(const struct ipt_ip *ip,
+         const struct ipt_entry_target *target,
+         int numeric)
+
+#else
+static void
+GTPUAH_print(const void *ip,
+           const struct xt_entry_target *target,
+           int numeric)
+#endif
+{
+    const struct xt_gtpuah_target_info *info =
+        (struct xt_gtpuah_target_info *) target->data;
+
+    char laddr[64], raddr[64], actionstr[32];
+
+    convert_action_to_string(info->action, actionstr);
+
+    sprintf (laddr, "%s", inet_ntoa(*(struct in_addr*)&info->laddr));
+    sprintf (raddr, "%s", inet_ntoa(*(struct in_addr*)&info->raddr));
+    printf("GTPUAH self: %s tunnel: 0x%x / peer: %s tunnel: 0x%x / action: %s",
+           laddr, info->ltun, raddr, info->rtun, actionstr);
+}
+
+static struct option GTPUAH_opts[] = {
+    { "own-ip", 1, NULL, '1' },
+    { "own-tun", 1, NULL, '2' },
+    { "peer-ip", 1, NULL, '3' },
+    { "peer-tun", 1, NULL, '4' },
+    { "action", 1, NULL, '5' },
+    { .name = NULL }
+};
+
+#if (IPTVERSION <= 135)
+static struct iptables_target gtpuah_tg_reg = {
+#else
+static struct xtables_target gtpuah_tg_reg = {
+#endif
+    .name             = "GTPUAH",
+    .version          = XT_GTPUAH_VERSION,
+#if (IPTVERSION > 135)
+    .family           = NFPROTO_IPV4,
+#endif
+    .size             = XT_ALIGN(sizeof(struct xt_gtpuah_target_info)),
+    .userspacesize    = XT_ALIGN(sizeof(struct xt_gtpuah_target_info)),
+    .help             = GTPUAH_help,
+    .parse            = GTPUAH_parse,
+    .final_check      = GTPUAH_check,
+    .print            = GTPUAH_print,
+    .extra_opts       = GTPUAH_opts,
+};
+
+void _init(void)
+{
+#if (IPTVERSION <= 135)
+    register_target(&gtpuah_tg_reg);
+#else
+    xtables_register_target(&gtpuah_tg_reg);
+#endif
+}
+

openair-cn/GTPV1-U/GTPUAH/xt_GTPUAH.c

+
+/*
+ * GTPu klm for Linux/iptables
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/route.h> 
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/inet_sock.h>
+#include <net/ip.h>
+#include <net/route.h> 
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#if 0
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+#endif
+
+#include "xt_GTPUAH.h"
+
+#if !(defined KVERSION)
+#error "Kernel version is not defined!!!! Exiting."
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pradip Biswas <pradip_biswas@polarisnetworks.net>");
+MODULE_DESCRIPTION("GTPu Data Path extension on netfilter");
+
+
+struct gtpuhdr
+{
+    char flags;
+    char msgtype;
+    u_int16_t length;
+    u_int32_t tunid;
+};
+
+#define GTPU_HDR_PNBIT 1
+#define GTPU_HDR_SBIT 1 << 1
+#define GTPU_HDR_EBIT 1 << 2
+#define GTPU_ANY_EXT_HDR_BIT (GTPU_HDR_PNBIT | GTPU_HDR_SBIT | GTPU_HDR_EBIT)
+
+#define GTPU_FAILURE 1
+#define GTPU_SUCCESS !GTPU_FAILURE
+
+#define GTPU_PORT 2152
+
+static bool _gtpuah_route_packet(struct sk_buff *skb, const struct xt_gtpuah_target_info *info)
+{
+    int err = 0; 
+    struct rtable *rt = NULL;
+    struct iphdr *iph = ip_hdr(skb); 
+    int daddr = iph->daddr;
+    struct flowi fl = { 
+        .u = {
+            .ip4 = {
+                .daddr        = daddr,
+                .flowi4_tos   = RT_TOS(iph->tos),
+                .flowi4_scope = RT_SCOPE_UNIVERSE,
+            } 
+        } 
+    }; 
+
+#if 0
+    pr_info("GTPUAH(%d): Routing packet: %d.%d.%d.%d --> %d.%d.%d.%d Proto: %d, Len: %d Mark: %u\n",
+            info->action,
+            iph->saddr  & 0xFF,
+            (iph->saddr & 0x0000FF00) >> 8,
+            (iph->saddr & 0x00FF0000) >> 16,
+            iph->saddr >> 24,
+            iph->daddr  & 0xFF,
+            (iph->daddr & 0x0000FF00) >> 8,
+            (iph->daddr & 0x00FF0000) >> 16,
+            iph->daddr >> 24,
+            iph->protocol,
+            ntohs(iph->tot_len),
+            skb->mark);
+#endif
+
+    rt = ip_route_output_key(&init_net, &fl.u.ip4);
+    if (err != 0) 
+    { 
+        pr_info("GTPU: Failed to route packet to dst 0x%x. Error: (%d)", fl.u.ip4.daddr, err);
+        return GTPU_FAILURE; 
+    } 
+
+#if 0
+    if (rt->dst.dev)
+    {
+        pr_info("GTPU: dst dev name %s\n", rt->dst.dev->name);
+    }
+    else
+    {
+        pr_info("GTPU: dst dev NULL\n"); 
+    }
+#endif
+
+    //if (info->action == PARAM_GTPUAH_ACTION_ADD) //LG was commented
+    {
+        skb_dst_drop(skb);
+        skb_dst_set(skb, &rt->dst);
+        skb->dev      = skb_dst(skb)->dev;
+    }
+
+    skb->protocol = htons(ETH_P_IP); 
+
+    /* Send the GTPu message out...gggH */
+    err = dst_output(skb);
+
+    if (err == 0)
+    {
+        return GTPU_SUCCESS;
+    }
+    else
+    {
+        return GTPU_FAILURE;
+    }
+}
+
+static unsigned int
+_gtpuah_target_add(struct sk_buff *skb, const struct xt_gtpuah_target_info *tgi)
+{
+    struct iphdr   *iph           = ip_hdr(skb);
+    struct udphdr  *udph          = NULL;
+    struct gtpuhdr *gtpuh         = NULL;
+    struct sk_buff *new_skb       = NULL;
+    int             headroom_reqd =  sizeof(struct iphdr) + sizeof(struct udphdr) + sizeof(struct gtpuhdr);
+    int             orig_iplen = 0, udp_len = 0, ip_len = 0;
+
+    if (skb->mark == 0) {
+        pr_info("GTPUAH: _gtpuah_target_add skb mark %u tgi mark %u", skb->mark, tgi->rtun);
+    }
+    /* Keep the length of the source IP packet */
+    orig_iplen = ntohs(iph->tot_len);
+
+    /* Create a new copy of the original skb...can't avoid :-( */
+    new_skb = skb_copy_expand(skb, headroom_reqd + skb_headroom(skb), skb_tailroom(skb), GFP_ATOMIC);
+    if (new_skb == NULL)
+    {
+        return NF_ACCEPT;
+    }
+
+    /* Add GTPu header */
+    gtpuh          = (struct gtpuhdr*)skb_push(new_skb, sizeof(struct gtpuhdr));
+    gtpuh->flags   = 0x30; /* v1 and Protocol-type=GTP */
+    gtpuh->msgtype = 0xff; /* T-PDU */
+    gtpuh->length  = htons(orig_iplen);
+    gtpuh->tunid   = htonl(skb->mark);
+
+    /* Add UDP header */
+    udp_len      = sizeof(struct udphdr) + sizeof(struct gtpuhdr) + orig_iplen;
+    udph         = (struct udphdr*)skb_push(new_skb, sizeof(struct udphdr));
+    udph->source = htons(GTPU_PORT);
+    udph->dest   = htons(GTPU_PORT);
+    udph->len    = htons(udp_len);
+    udph->check  = 0;
+    udph->check  = csum_tcpudp_magic(tgi->laddr,
+            tgi->raddr,
+            udp_len,
+            IPPROTO_UDP,
+            csum_partial((char*)udph, udp_len, 0));
+    skb_set_transport_header(new_skb, 0);
+
+    /* Add IP header */
+    ip_len = udp_len + sizeof(struct iphdr);
+    iph = (struct iphdr*)skb_push(new_skb, sizeof(struct iphdr));
+    iph->ihl      = 5;
+    iph->version  = 4;
+    iph->tos      = 0;
+    iph->tot_len  = htons(ip_len);
+    iph->id       = 0;
+    iph->frag_off = 0;
+    iph->ttl      = 64;
+    iph->protocol = IPPROTO_UDP;
+    iph->check    = 0;
+    iph->saddr    = (tgi->laddr);
+    iph->daddr    = (tgi->raddr);
+    iph->check    = ip_fast_csum((unsigned char *)iph, iph->ihl);
+    skb_set_network_header(new_skb, 0);
+
+    /* Route the packet */
+    if (_gtpuah_route_packet(new_skb, tgi) == GTPU_SUCCESS)
+    {
+        /* Succeeded. Drop the original packet */
+        return NF_DROP;
+    }
+    else
+    {
+        kfree_skb(new_skb);
+        return NF_ACCEPT; /* What should we do here ??? ACCEPT seems to be the best option */
+    }
+}
+
+
+
+static unsigned int
+xt_gtpuah_target(struct sk_buff *skb, const struct xt_action_param *par)
+{
+    const struct xt_gtpuah_target_info *tgi = par->targinfo;
+    int result = NF_ACCEPT;
+
+    if (tgi == NULL)
+    {
+        return result;
+    }
+
+    if (tgi->action == PARAM_GTPUAH_ACTION_ADD)
+    {
+        result = _gtpuah_target_add(skb, tgi);
+    }
+    return result;
+}
+
+static struct xt_target xt_gtpuah_reg __read_mostly =
+{
+    .name           = "GTPUAH",
+    .revision       = 0,
+    .family         = AF_INET,
+    .hooks          = (1 << NF_INET_FORWARD) |
+                      (1 << NF_INET_POST_ROUTING),
+    .table          = "mangle",
+    .target         = xt_gtpuah_target,
+    .targetsize     = sizeof(struct xt_gtpuah_target_info),
+    .me             = THIS_MODULE,
+};
+
+static int __init xt_gtpuah_init(void)
+{
+    pr_info("GTPUAH: Initializing module (KVersion: %d)\n", KVERSION);
+    pr_info("GTPUAH: Copyright Polaris Networks 2010-2011\n");
+    return xt_register_target(&xt_gtpuah_reg);
+}
+
+static void __exit xt_gtpuah_exit(void)
+{
+    xt_unregister_target(&xt_gtpuah_reg);
+    pr_info("GTPUAH: Unloading module\n");
+}
+
+module_init(xt_gtpuah_init);
+module_exit(xt_gtpuah_exit);
+

openair-cn/GTPV1-U/GTPUAH/xt_GTPUAH.h

+/* Shared header file for iptables extension for the GTPU target and GTPu KLM
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+enum xt_gtpuah_mode_
+{
+    PARAM_GTPUAH_ACTION_ADD = 1 << 8,
+};
+
+struct xt_gtpuah_target_info
+{
+    u_int32_t laddr;
+    u_int32_t raddr;
+    u_int32_t ltun;
+    u_int32_t rtun;
+    u_int32_t action;
+};
+

openair-cn/GTPV1-U/GTPURH/INSTALL

+How to build
+------------
+
+1. Extract the files in a location of your choice. The
+   Files will be extracted in a directory called gtpu.
+
+2. cd <gtpu_dir>/gtpu. 
+
+3. make
+
+If make is successful, the binary files (libxt_GTPU.so and xt_GTPU.ko) 
+will be created in the Bin folder.
+
+
+How to install
+--------------
+There is no "make install" as that will be difficult to support all
+possible Linux distro. The cmd.sh file demonstrates how to install
+the two binary files in the system.
+
+
+In case of problem:
+ - check you got the last release of the library (see README),
+ - contact the mailing list (see README),
+ - check the bugtracker for known bugs (see README).
+
+
+Documentation
+-------------
+Please have a look at the "Architecture" section in the README.
+
+
+

openair-cn/GTPV1-U/GTPURH/Makefile

+####################################################################################
+# Makefile for iptables extension for the GTPU target and GTPu klm
+#
+# Copyright (c) 2010-2011 Polaris Networks
+# Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+####################################################################################
+
+export BIN_DIR ?= $(shell pwd)/Bin
+KVERSION = $(shell uname -r)
+KVERSION_LAST_DIGIT = $(shell echo ${KVERSION} | cut -d "." -f 3 | cut -d "-" -f 1)
+
+obj-m = xt_GTPURH.o
+EXTRA_CFLAGS += -DKVERSION=$(KVERSION_LAST_DIGIT)
+
+all: xtlib
+	echo "Building for Kernel Version: $(KVERSION_LAST_DIGIT)"
+	make -C /lib/modules/$(KVERSION)/build M=$(PWD) modules
+	mv xt_GTPURH.ko $(BIN_DIR)/
+
+clean: libclean
+	make -C /lib/modules/$(KVERSION)/build M=$(PWD) clean
+
+################################################################################
+# The next section is used by libxt_GTPURH
+################################################################################
+
+XT_IPTABLES_VERSION = $(shell /sbin/iptables -V | cut -d " " -f 2 | cut -b 2-)
+IPT_FIRST_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 1 | cut -d "-" -f 1)
+IPT_SECOND_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 2 | cut -d "-" -f 1)
+IPT_THIRD_NUM = $(shell echo ${XT_IPTABLES_VERSION} | cut -d "." -f 3 | cut -d "-" -f 1)
+IPTVERSION = $(IPT_FIRST_NUM)$(IPT_SECOND_NUM)$(IPT_THIRD_NUM)
+IPTABLES_VERSION_STRING = \"$(IPT_FIRST_NUM).$(IPT_SECOND_NUM).$(IPT_THIRD_NUM)\"
+
+LIB_CC := gcc
+
+ifeq ($(IPTVERSION), 135)
+    LIB_LD := ld 
+else
+    LIB_LD := gcc 
+endif
+
+LIB_CFLAGS := -fPIC -Wall -MMD -D_LARGEFILE_SOURCE=1 -D_LARGE_FILES -D_FILE_OFFSET_BITS=64 \
+          -D_REENTRANT -pipe -DXTABLES_LIBDIR=\"/usr/local/libexec/xtables\" -DXTABLES_INTERNAL \
+          -D_INIT=libxt_GTPURH_init -DPIC -fPIC -O2 \
+          -DIPTVERSION=$(IPTVERSION) \
+          -DIPTABLES_VERSION_STRING=$(IPTABLES_VERSION_STRING)
+
+XT_TARGET := xt_GTPURH
+XT_LIBNAME := lib$(XT_TARGET).so
+XT_BUILD_DIR = $(BIN_DIR)/$(XT_TARGET)
+
+# Get the system distribution type
+IsDebian=$(shell /bin/cat /proc/version | grep -i -e ubuntu -e debian)
+IsRedHat=$(shell /bin/cat /proc/version | grep -i -e centos -e "red hat" -e suse -e fedora) 
+
+# Change the ipq library name for 64-bit Debian-based distributions
+ifeq ($(X86_64),x86_64)
+    ifneq ($(strip $(IsDebian)),)
+        LIB_IPQ=_pic
+    endif
+endif
+
+INCLUDE_DIR = -I. \
+              -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include \
+              -I/usr/lib64/glib-2.0/include
+
+XT_SOURCES = libxt_GTPURH.c
+
+XT_OBJECTS := $(addprefix $(XT_BUILD_DIR)/, $(notdir $(XT_SOURCES:.c=.o)))
+
+xtlib: XT
+
+XT: DF = $(XT_BUILD_DIR)/$(*F)
+XT: $(XT_BUILD_DIR) $(BIN_DIR)/$(XT_LIBNAME)
+
+-include $(addprefix $(XT_BUILD_DIR)/, $(notdir $(XT_SOURCES:.c=.P)))
+
+$(XT_BUILD_DIR):
+	@echo Build Directory is $@
+	@if [ ! -d $(BIN_DIR) ]; then mkdir $(BIN_DIR); fi
+	@if [ ! -d $@ ]; then mkdir $@; fi
+
+$(BIN_DIR)/$(XT_LIBNAME): $(XT_OBJECTS)
+	@echo Linking $@
+	@$(LIB_LD) -shared $(XT_OBJECTS) -o $@
+
+$(XT_BUILD_DIR)/%.o : %.c
+	@echo "Building GTPuRH ext for version $(IPTVERSION) $(IPTABLES_VERSION_STRING)"
+	@echo Compiling $<
+	@$(LIB_CC) $(LIB_CFLAGS) -MF $(DF).d $(INCLUDE_DIR) -o $@ -c $<
+	@cp $(DF).d $(DF).P; \
+	sed -e 's/#.*//' -e 's/^[^:]*: *//' -e 's/ *\\$$//' \
+		-e '/^$$/ d' -e 's/$$/ :/' < $(DF).d >> $(DF).P; \
+	rm -f $(DF).d
+
+libclean:
+	@rm -rf $(BIN_DIR)/$(XT_LIBNAME) $(XT_BUILD_DIR)
+

openair-cn/GTPV1-U/GTPURH/README

+Introduction
+------------
+This piece of software implementes GPRS Tunneling Protocol (GTP) for user plane.
+The software has two components - one is the extension of iptables that
+run in user-space. The other is the counterpart of the iptables extension
+that runs in kernel space.
+
+
+License
+-------
+The project is licensed under GPL2+, see the COPYING and AUTHORS files for more
+details.
+
+
+Architecture
+------------
+The GTPu tunneling is handled in two parts. The first part is the user-space 
+iptables target extension library (let's call it libxt). The second
+part is the GTPu kernel loadable module (let's call it gtpu). The way it 
+is, once the user configures a GTPu tunnel attributes using iptables, the klm
+is loaded by the kernel automatically and handles the IP packets according to
+the GTPu tunnel attributes set by the user. 
+
+The user can set the action to be taken on a matching IP packet. The action can be
+either of "add", "remove" or "transport" .
+
+A GTPu tunnel has the following attributes:
+  - own IP address
+  - own GTPu tunnel id
+  - peer's IP address
+  - peer's GTPu tunnel id
+
+The GTPU target is designed to work only on mangle table. Also, the user is 
+expected to add GTPU target to the PREROUTING chain, as the GTPU target will
+modify the original IP packet before it is routed.
+
+Once the user creates the rule in iptables, the matching IP packets go through 
+the gtpu klm, which acts upon the IP packet according to the action set by the
+user. The action "Add" means the klm will add a GTPu header to the IP packet.
+"Remove" will remove the GTPu header from the IP packet and "Transport" will
+do a Remove first followed by an "Add" on the IP packet.
+
+For example, consider the following command:
+
+iptables -t mangle -A PREROUTING -d 10.10.10.1 -j GTPU --own-ip 192.168.0.98 --own-tun 100 --peer-ip 192.168.0.109 --peer-tun 101 --action add
+
+This command will configure the system to add a GTPu header to any IP packet destined to 10.10.10.1. 
+The source IP address outer IP will be 192.168.0.109, the dest IP will be 192.168.0.98 and
+the destination GTP tunnel id will be 101.
+
+Similarly, consider the following command:
+
+iptables -t mangle -A PREROUTING -s 192.168.0.109 -d 192.168.0.98 -p udp --dport 2152 -j GTPU --action remove
+
+This command will process all the GTPu packets coming from 192.168.0.109 to 192.168.0.98 to
+strip the GTPu header and forward the inner IP packet to the kernel's routing engine.
+
+
+Files
+---------
+There are two source C files and one header file:
+ - libxt_GTPU.c  : source file for iptables GTPU extension library (libxt)
+ - xt_GTPU.c     : source file for gtpu kernel loadable module (klm)
+ - xt_GTPU.h     : common header file, shared between the libxt and the klm
+ - Makefile      : Makefile to build both the libxt and the klm
+ - cmd.sh        : sample cmd file to show how the binaries can be used
+
+See the INSTALL file to learn how to build the binaries.
+
+
+References
+----------
+3GPP TS 29.281      General Packet Radio System (GPRS)
+                    Tunnelling Protocol User Plane (GTP-u)
+
+
+Authors
+-------
+Pradip Biswas <pradip_biswas@polarisnetworks.net>
+

openair-cn/GTPV1-U/GTPURH/RELEASE_NOTES

+
+Known issues in GTPU v1.0
+-------------------------
+
+1. Does not implement the "Transport" action.
+2. Does not handle segmented GTPu packets.
+

openair-cn/GTPV1-U/GTPURH/cmd.sh

+# Clear the iptables mangle table
+iptables -t mangle -F
+
+# Remove GTPU KLM
+rmmod xt_GTPU
+
+# Insert the GTPU KLM
+insmod ./Bin/xt_GTPU.ko
+
+# Copy the userland iptables extenstion library
+if [ -d /lib/xtables ]; then
+    /bin/cp -f ./Bin/libxt_GTPU.so /lib/xtables/
+fi
+
+if [ -d /lib/iptables ]; then
+    /bin/cp -f ./Bin/libxt_GTPU.so /lib/iptables/libipt_GTPU.so
+fi
+
+# Some sample commands for demonstration
+iptables -t mangle -A PREROUTING -d 10.10.10.1 -j GTPU --own-ip 192.168.0.98 --own-tun 100 --peer-ip 192.168.0.109 --peer-tun 101 --action add
+iptables -t mangle -A PREROUTING -s 192.168.0.109 -d 192.168.0.98 -p udp --dport 2152 -j GTPU --action remove

openair-cn/GTPV1-U/GTPURH/libxt_GTPURH.c

+/* Shared library add-on to iptables for the GTPURH target
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <getopt.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <linux/netfilter.h>
+
+#include "xt_GTPURH.h"
+
+#if (IPTVERSION <= 135)
+#include <iptables.h>
+#elif (IPTVERSION > 135)
+#include <xtables.h>
+#endif
+
+#if (IPTVERSION <= 135)
+#define GTPURH_PARAM_BAD_VALUE 0
+#define GTPURH_PARAM_ONLY_ONCE 1
+#define XT_GTPURH_VERSION IPTABLES_VERSION_STRING
+#define gtpurh_strtoui(s,v,m,M) !string_to_number(s,m,M,v)
+#define gtpurh_exit_error exit_error
+#elif (IPTVERSION > 135) && (IPTVERSION <= 141) 
+#define GTPURH_PARAM_BAD_VALUE P_BAD_VALUE
+#define GTPURH_PARAM_ONLY_ONCE P_ONLY_ONCE
+#define XT_GTPURH_VERSION XTABLES_VERSION
+#define gtpurh_param_act param_act
+#define gtpurh_strtoui(s,v,m,M) !string_to_number(s,m,M,v)
+#define gtpurh_exit_error exit_error
+#elif (IPTVERSION > 141)
+#define GTPURH_PARAM_BAD_VALUE XTF_BAD_VALUE
+#define GTPURH_PARAM_ONLY_ONCE XTF_ONLY_ONCE
+#define XT_GTPURH_VERSION XTABLES_VERSION
+#define gtpurh_param_act xtables_param_act
+#define gtpurh_strtoui(s,v,m,M) xtables_strtoui(s,NULL,v,m,M)
+#define gtpurh_exit_error xtables_error
+#endif
+
+enum {
+    PARAM_ACTION = 1 << 0,
+};
+
+static void GTPURH_help(void)
+{
+    printf(
+"GTPURH target options\n"
+"  --action         value        Set action <value: remove>\n");
+}
+
+#if (IPTVERSION <= 135)
+/* Stolen from iptables v1.4.7 code */
+void gtpurh_param_act(unsigned int status, const char *p1, ...)
+{
+        const char *p2, *p3;
+        va_list args;
+        int b;
+
+        va_start(args, p1);
+
+        switch (status) {
+        case GTPURH_PARAM_ONLY_ONCE:
+                p2 = va_arg(args, const char *);
+                b  = va_arg(args, unsigned int);
+                if (!b)
+                        return;
+                exit_error(PARAMETER_PROBLEM,
+                           "%s: \"%s\" option may only be specified once",
+                           p1, p2);
+                break;
+        case GTPURH_PARAM_BAD_VALUE:
+                p2 = va_arg(args, const char *);
+                p3 = va_arg(args, const char *);
+                exit_error(PARAMETER_PROBLEM,
+                           "%s: Bad value for \"%s\" option: \"%s\"",
+                           p1, p2, p3);
+                break;
+        default:
+                exit_error(status, "%s", "Unknown error");
+                break;
+        }
+
+        va_end(args);
+}
+
+#endif
+
+
+
+static void parse_gtpurh_action(char *s, struct xt_gtpurh_target_info *info, unsigned int *flags)
+{
+    if (!strcmp(s, "remove"))
+    {
+        info->action = PARAM_GTPURH_ACTION_REM;
+        *flags |= PARAM_GTPURH_ACTION_REM;
+    }
+    else
+    {
+        gtpurh_param_act(GTPURH_PARAM_BAD_VALUE, "GTPURH", "--action", s);
+    }
+}
+
+#if (IPTVERSION <= 135)
+static int
+GTPURH_parse(int c, char **argv, int invert, unsigned int *flags,
+           const struct ipt_entry *entry,
+           struct ipt_entry_target **target)
+#else
+static int
+GTPURH_parse(int c, char **argv, int invert, unsigned int *flags,
+           const void *entry, struct xt_entry_target **target)
+#endif
+{
+    struct xt_gtpurh_target_info *info = (struct xt_gtpurh_target_info *) (*target)->data;
+
+    switch (c) 
+    {
+        case '1':
+                gtpurh_param_act(GTPURH_PARAM_ONLY_ONCE, "GTPURH", "--action", *flags & PARAM_ACTION);
+                parse_gtpurh_action(optarg, info, flags);
+                *flags |= PARAM_ACTION;
+                return 1;
+    }
+
+    return 1;
+}
+
+static void GTPURH_check(unsigned int flags)
+{
+    if (!(flags & PARAM_ACTION))
+    {
+        gtpurh_exit_error(PARAMETER_PROBLEM, "GTPURH: You must specify action");
+    }
+
+    if (flags & PARAM_GTPURH_ACTION_REM)
+    {
+        return;
+    }
+}
+
+static void convert_action_to_string(int action, char *actionstr)
+{
+    switch(action)
+    {
+        case PARAM_GTPURH_ACTION_REM:
+            sprintf (actionstr, "remove");
+            break;
+        default :
+            sprintf (actionstr, "unspecified!!!");
+            break;
+    }
+}
+
+#if (IPTVERSION <= 135)
+static void
+GTPURH_print(const struct ipt_ip *ip,
+         const struct ipt_entry_target *target,
+         int numeric)
+
+#else
+static void
+GTPURH_print(const void *ip,
+           const struct xt_entry_target *target,
+           int numeric)
+#endif
+{
+    const struct xt_gtpurh_target_info *info =
+        (struct xt_gtpurh_target_info *) target->data;
+
+    char laddr[64], raddr[64], actionstr[32];
+
+    convert_action_to_string(info->action, actionstr);
+
+    if (info->action == PARAM_GTPURH_ACTION_REM)
+    {
+        printf("GTPURH action: %s", actionstr);
+        return;
+    }
+}
+
+static struct option GTPURH_opts[] = {
+    { "action", 1, NULL, '1' },
+    { .name = NULL }
+};
+
+#if (IPTVERSION <= 135)
+static struct iptables_target gtpurh_tg_reg = {
+#else
+static struct xtables_target gtpurh_tg_reg = {
+#endif
+    .name             = "GTPURH",
+    .version          = XT_GTPURH_VERSION,
+#if (IPTVERSION > 135)
+    .family           = NFPROTO_IPV4,
+#endif
+    .size             = XT_ALIGN(sizeof(struct xt_gtpurh_target_info)),
+    .userspacesize    = XT_ALIGN(sizeof(struct xt_gtpurh_target_info)),
+    .help             = GTPURH_help,
+    .parse            = GTPURH_parse,
+    .final_check      = GTPURH_check,
+    .print            = GTPURH_print,
+    .extra_opts       = GTPURH_opts,
+};
+
+void _init(void)
+{
+#if (IPTVERSION <= 135)
+    register_target(&gtpurh_tg_reg);
+#else
+    xtables_register_target(&gtpurh_tg_reg);
+#endif
+}
+

openair-cn/GTPV1-U/GTPURH/xt_GTPURH.c

+
+/*
+ * GTPu klm for Linux/iptables
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/ip.h>
+#include <linux/route.h> 
+#include <net/checksum.h>
+#include <net/udp.h>
+#include <net/inet_sock.h>
+#include <net/ip.h>
+#include <net/route.h> 
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#if 0
+#include <net/netfilter/ipv4/nf_defrag_ipv4.h>
+#endif
+
+#include "xt_GTPURH.h"
+
+#if !(defined KVERSION)
+#error "Kernel version is not defined!!!! Exiting."
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Pradip Biswas <pradip_biswas@polarisnetworks.net>");
+MODULE_DESCRIPTION("GTPu Data Path extension on netfilter");
+
+
+struct gtpuhdr
+{
+    char flags;
+    char msgtype;
+    u_int16_t length;
+    u_int32_t tunid;
+};
+
+#define GTPURH_HDR_PNBIT 1
+#define GTPURH_HDR_SBIT 1 << 1
+#define GTPURH_HDR_EBIT 1 << 2
+#define GTPURH_ANY_EXT_HDR_BIT (GTPURH_HDR_PNBIT | GTPURH_HDR_SBIT | GTPURH_HDR_EBIT)
+
+#define GTPURH_FAILURE 1
+#define GTPURH_SUCCESS !GTPURH_FAILURE
+
+#define GTPURH_PORT 2152
+
+static bool _gtpurh_route_packet(struct sk_buff *skb, const struct xt_gtpurh_target_info *info)
+{
+    int err = 0; 
+    struct rtable *rt = NULL;
+    struct iphdr *iph = ip_hdr(skb); 
+    int daddr = iph->daddr;
+    struct flowi fl = { 
+        .u = {
+            .ip4 = {
+                .daddr        = daddr,
+                .flowi4_tos   = RT_TOS(iph->tos),
+                .flowi4_scope = RT_SCOPE_UNIVERSE,
+            } 
+        } 
+    }; 
+
+#if 0
+    pr_info("GTPURH(%d): Routing packet: %d.%d.%d.%d --> %d.%d.%d.%d Proto: %d, Len: %d Mark: %u\n",
+            info->action,
+            iph->saddr  & 0xFF,
+            (iph->saddr & 0x0000FF00) >> 8,
+            (iph->saddr & 0x00FF0000) >> 16,
+            iph->saddr >> 24,
+            iph->daddr  & 0xFF,
+            (iph->daddr & 0x0000FF00) >> 8,
+            (iph->daddr & 0x00FF0000) >> 16,
+            iph->daddr >> 24,
+            iph->protocol,
+            ntohs(iph->tot_len),
+            skb->mark);
+#endif
+
+    rt = ip_route_output_key(&init_net, &fl.u.ip4);
+    if (err != 0) 
+    { 
+        pr_info("GTPURH: Failed to route packet to dst 0x%x. Error: (%d)", fl.u.ip4.daddr, err);
+        return GTPURH_FAILURE;
+    } 
+
+#if 0
+    if (rt->dst.dev)
+    {
+        pr_info("GTPURH: dst dev name %s\n", rt->dst.dev->name);
+    }
+    else
+    {
+        pr_info("GTPURH: dst dev NULL\n");
+    }
+#endif
+
+    //if (info->action == PARAM_GTPURH_ACTION_ADD) //LG was commented
+    {
+        skb_dst_drop(skb);
+        skb_dst_set(skb, &rt->dst);
+        skb->dev      = skb_dst(skb)->dev;
+    }
+
+    skb->protocol = htons(ETH_P_IP); 
+
+    /* Send the GTPu message out...gggH */
+    err = dst_output(skb);
+
+    if (err == 0)
+    {
+        return GTPURH_SUCCESS;
+    }
+    else
+    {
+        return GTPURH_FAILURE;
+    }
+}
+
+static unsigned int
+_gtpurh_target_rem(struct sk_buff *orig_skb, const struct xt_gtpurh_target_info *tgi)
+{
+    struct iphdr   *iph   = ip_hdr(orig_skb);
+    struct iphdr   *iph2  = NULL;
+    struct gtpuhdr *gtpuh = NULL;
+    struct sk_buff *skb   = NULL;
+    uint16_t        gtp_payload_size = 0;
+
+    /* Create a new copy of the original skb...can't avoid :-( LG: WHY???*/
+#if defined(ROUTE_PACKET)
+    skb = skb_copy(orig_skb, GFP_ATOMIC);
+    if (skb == NULL)
+    {
+        return NF_ACCEPT;
+    }
+    skb->skb_iif  = orig_skb->skb_iif;
+    skb->protocol = orig_skb->protocol;
+#else
+    skb = orig_skb;
+#endif
+
+    /* Remove IP header */
+    skb_pull(skb, (iph->ihl << 2));
+
+    /* Remove UDP header */
+    gtpuh = (struct gtpuhdr*)skb_pull(skb, sizeof(struct udphdr));
+    gtp_payload_size = ntohs(gtpuh->length);
+
+    skb->mark = ntohl(gtpuh->tunid);
+    /* Remove GTPu header */
+    skb_pull(skb, sizeof(struct gtpuhdr));
+
+    /* If additional fields are present in header, remove them also */
+    if (gtpuh->flags & GTPURH_ANY_EXT_HDR_BIT)
+    {
+        skb_pull(skb, sizeof(short) + sizeof(char) + sizeof(char)); /* #Seq, #N-PDU, #ExtHdr Type */
+        gtp_payload_size = gtp_payload_size - sizeof(short) - sizeof(char) - sizeof(char);
+    }
+    //skb->mac_len = 0;
+    //skb_set_mac_header(skb, 0);
+    skb_set_network_header(skb, 0);
+    iph2   = ip_hdr(skb);
+    skb_set_transport_header(skb, iph2->ihl << 2);
+
+//#if 0
+    if ((skb->mark == 0) || (gtp_payload_size != ntohs(iph2->tot_len))) {
+        pr_info("GTPURH(%d): Decapsulating packet: %d.%d.%d.%d --> %d.%d.%d.%d Proto: %d, Total Len (IP): %u mark %u Frag offset %u Flags 0x%0x\n",
+                tgi->action,
+                iph2->saddr  & 0xFF,
+                (iph2->saddr & 0x0000FF00) >> 8,
+                (iph2->saddr & 0x00FF0000) >> 16,
+                iph2->saddr >> 24,
+                iph2->daddr  & 0xFF,
+                (iph2->daddr & 0x0000FF00) >> 8,
+                (iph2->daddr & 0x00FF0000) >> 16,
+                iph2->daddr >> 24,
+                iph2->protocol,
+                ntohs(iph2->tot_len),
+                skb->mark,
+                ntohs(iph->frag_off) & 0x1FFFFFFF,
+                ntohs(iph->frag_off) >> 13);
+
+        if (gtp_payload_size != ntohs(iph2->tot_len)) {
+            pr_info("\nGTPURH(%d): Mismatch in lengths GTPU length: %u -> %u, IP length %u\n\n",
+                    ntohs(gtpuh->length), gtp_payload_size, ntohs(iph->tot_len));
+        }
+    }
+//#endif
+
+    /* Route the packet */
+#if defined(ROUTE_PACKET)
+    _gtpurh_route_packet(skb, tgi);
+    return NF_DROP;
+#else
+    return NF_ACCEPT;
+#endif
+}
+
+
+static unsigned int
+xt_gtpurh_target(struct sk_buff *skb, const struct xt_action_param *par)
+{
+    const struct xt_gtpurh_target_info *tgi = par->targinfo;
+    int result = NF_ACCEPT;
+
+    if (tgi == NULL)
+    {
+        return result;
+    }
+
+    if (tgi->action == PARAM_GTPURH_ACTION_REM)
+    {
+        result = _gtpurh_target_rem(skb, tgi);
+    }
+    return result;
+}
+
+static struct xt_target xt_gtpurh_reg __read_mostly =
+{
+    .name           = "GTPURH",
+    .revision       = 0,
+    .family         = AF_INET,
+    .hooks          = (1 << NF_INET_PRE_ROUTING),
+    .table          = "raw",
+    .target         = xt_gtpurh_target,
+    .targetsize     = sizeof(struct xt_gtpurh_target_info),
+    .me             = THIS_MODULE,
+};
+
+static int __init xt_gtpurh_init(void)
+{
+    pr_info("GTPURH: Initializing module (KVersion: %d)\n", KVERSION);
+    pr_info("GTPURH: Copyright Polaris Networks 2010-2011\n");
+    return xt_register_target(&xt_gtpurh_reg);
+}
+
+static void __exit xt_gtpurh_exit(void)
+{
+    xt_unregister_target(&xt_gtpurh_reg);
+    pr_info("GTPURH: Unloading module\n");
+}
+
+module_init(xt_gtpurh_init);
+module_exit(xt_gtpurh_exit);
+

openair-cn/GTPV1-U/GTPURH/xt_GTPURH.h

+/* Shared header file for iptables extension for the GTPU target and GTPu KLM
+ *
+ * Copyright (c) 2010-2011 Polaris Networks
+ * Author: Pradip Biswas <pradip_biswas@polarisnetworks.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+enum xt_gtpurh_mode_
+{
+    PARAM_GTPURH_ACTION_REM = 1 << 9,
+};
+
+struct xt_gtpurh_target_info
+{
+    u_int32_t laddr;
+    u_int32_t raddr;
+    u_int32_t ltun;
+    u_int32_t rtun;
+    u_int32_t action;
+};
+