Migrate to ocproxy-based TCP proxy implementation with VPN integration

This commit is contained in:
Hackintosh Five 2023-06-13 19:20:45 +01:00
parent 0278906574
commit c767d81251
15 changed files with 1441 additions and 15 deletions

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/tcpproxy

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[submodule "lwip"]
path = lwip
url = https://git.savannah.nongnu.org/git/lwip.git

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.idea/misc.xml generated Normal file
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<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
<component name="CMakeWorkspace" PROJECT_DIR="$PROJECT_DIR$" />
</project>

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.idea/modules.xml generated Normal file
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<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
<component name="ProjectModuleManager">
<modules>
<module fileurl="file://$PROJECT_DIR$/.idea/tcpproxy.iml" filepath="$PROJECT_DIR$/.idea/tcpproxy.iml" />
</modules>
</component>
</project>

2
.idea/tcpproxy.iml generated Normal file
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<?xml version="1.0" encoding="UTF-8"?>
<module classpath="CMake" type="CPP_MODULE" version="4" />

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<?xml version="1.0" encoding="UTF-8"?>
<project version="4">
<component name="VcsDirectoryMappings">
<mapping directory="$PROJECT_DIR$" vcs="Git" />
<mapping directory="$PROJECT_DIR$/lwip" vcs="Git" />
</component>
</project>

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CMakeLists.txt Normal file
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cmake_minimum_required(VERSION 3.25)
project(tcpproxy C)
set(LWIP_DIR ${CMAKE_CURRENT_SOURCE_DIR}/lwip)
set(LWIP_CONTRIB_DIR ${LWIP_DIR}/contrib)
set (LWIP_INCLUDE_DIRS
"${LWIP_DIR}/src/include"
"${LWIP_CONTRIB_DIR}"
"${LWIP_CONTRIB_DIR}/ports/unix/port/include"
"${CMAKE_CURRENT_SOURCE_DIR}/src")
include(${LWIP_DIR}/src/Filelists.cmake)
include(${LWIP_DIR}/contrib/Filelists.cmake)
include(${LWIP_DIR}/contrib/ports/unix/Filelists.cmake)
set(CMAKE_C_STANDARD 11)
find_library(LIBEVENT event_core)
add_executable(tcpproxy src/main.c ${lwipcontribportunix_SRCS})
target_include_directories(tcpproxy PRIVATE ${LWIP_INCLUDE_DIRS})
target_compile_options(tcpproxy PRIVATE ${LWIP_COMPILER_FLAGS})
target_compile_definitions(tcpproxy PRIVATE ${LWIP_DEFINITIONS} ${LWIP_MBEDTLS_DEFINITIONS})
target_link_libraries(tcpproxy ${LWIP_SANITIZER_LIBS} lwipcontribexamples lwipcontribapps lwipcontribaddons lwipallapps lwipcontribportunix lwipcore lwipmbedtls ${LIBEVENT})

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FROM haproxy:lts
ENV PORT=3890
EXPOSE $PORT
ADD haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
FROM debian:bookworm-slim AS builder
RUN apt-get update && apt-get install -y build-essential cmake 'libevent-dev=2.1.*'
COPY CMakeLists.txt /app/src/
COPY NOTICE /app/src/
COPY lwip /app/src/lwip/
COPY src /app/src/src/
RUN mkdir /app/build && cd /app/build && cmake /app/src && make && mv tcpproxy ..
FROM debian:bookworm-slim
RUN apt-get update && apt-get install -y --no-install-recommends openconnect libevent-core-2.1-7
COPY --from=builder /app/tcpproxy /app/
COPY --from=builder /app/src/NOTICE /app/
COPY --from=builder /app/src/lwip/COPYING /app/
COPY docker-entrypoint.sh /app/
ARG HOST
EXPOSE 1234
USER nobody
ENTRYPOINT ["/app/docker-entrypoint.sh"]

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Copyright (c) 2023 Penn Mackintosh <penn@pennmack.co.uk>
Adapted from [ocproxy](https://github.com/cernekee/ocproxy) to use upgrade LwIP, remove LDAP functionality
Copyright (c) 2016 Google Inc.
Copyright (c) 2012-2014 David Edmondson <dme@dme.org>
Copyright (c) 2012-2014 Kevin Cernekee <cernekee@gmail.com>
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. 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.

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#!/bin/bash
echo openconnect --script-tun --script "/app/tcpproxy -L 1234:$HOST" "$@"
exec openconnect --script-tun --script "/app/tcpproxy -L 1234:$HOST" "$@"

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global
defaults
mode tcp
timeout connect 5s
timeout client 50s
timeout server 50s
listen tcp-in
bind "0.0.0.0:${PORT}"
server server1 "${TARGET}"

1
lwip Submodule

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Subproject commit e29870c15e8bf28eac9c811dd236c474f3f2008f

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src/lwipopts.h Normal file
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/*
* Copyright (c) 2001-2003 Swedish Institute of Computer Science.
* 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. 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.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels <adam@sics.se>
*
*/
#ifndef LWIP_LWIPOPTS_H
#define LWIP_LWIPOPTS_H
#ifdef LWIP_OPTTEST_FILE
#include "lwipopts_test.h"
#else /* LWIP_OPTTEST_FILE */
#define LWIP_IPV4 1
#define LWIP_IPV6 1
#define NO_SYS 0
#define LWIP_SOCKET 0
#define LWIP_NETCONN 0
#define LWIP_NETIF_API (NO_SYS==0)
#define LWIP_IGMP 0
#define LWIP_ICMP LWIP_IPV4
#define LWIP_SNMP LWIP_UDP
#ifdef LWIP_HAVE_MBEDTLS
#define LWIP_SNMP_V3 (LWIP_SNMP)
#endif
#define LWIP_DNS LWIP_UDP
#define LWIP_MDNS_RESPONDER LWIP_UDP
#define LWIP_NUM_NETIF_CLIENT_DATA (LWIP_MDNS_RESPONDER)
#define LWIP_HAVE_LOOPIF 1
#define LWIP_NETIF_LOOPBACK 1
#define LWIP_SINGLE_NETIF 1
#define LWIP_LOOPBACK_MAX_PBUFS 10
#define TCP_LISTEN_BACKLOG 1
#define LWIP_COMPAT_SOCKETS 1
#define LWIP_SO_RCVTIMEO 1
#define LWIP_SO_RCVBUF 1
#define LWIP_TCPIP_CORE_LOCKING 1
#define LWIP_NETIF_LINK_CALLBACK 1
#define LWIP_NETIF_STATUS_CALLBACK 1
#define LWIP_NETIF_EXT_STATUS_CALLBACK 1
#ifdef LWIP_DEBUG
#define LWIP_DBG_MIN_LEVEL 0
#define PPP_DEBUG LWIP_DBG_OFF
#define MEM_DEBUG LWIP_DBG_OFF
#define MEMP_DEBUG LWIP_DBG_OFF
#define PBUF_DEBUG LWIP_DBG_OFF
#define API_LIB_DEBUG LWIP_DBG_OFF
#define API_MSG_DEBUG LWIP_DBG_OFF
#define TCPIP_DEBUG LWIP_DBG_OFF
#define NETIF_DEBUG LWIP_DBG_OFF
#define SOCKETS_DEBUG LWIP_DBG_OFF
#define DNS_DEBUG LWIP_DBG_OFF
#define AUTOIP_DEBUG LWIP_DBG_OFF
#define DHCP_DEBUG LWIP_DBG_OFF
#define IP_DEBUG LWIP_DBG_OFF
#define IP_REASS_DEBUG LWIP_DBG_OFF
#define ICMP_DEBUG LWIP_DBG_OFF
#define IGMP_DEBUG LWIP_DBG_OFF
#define UDP_DEBUG LWIP_DBG_OFF
#define TCP_DEBUG LWIP_DBG_OFF
#define TCP_INPUT_DEBUG LWIP_DBG_OFF
#define TCP_OUTPUT_DEBUG LWIP_DBG_OFF
#define TCP_RTO_DEBUG LWIP_DBG_OFF
#define TCP_CWND_DEBUG LWIP_DBG_OFF
#define TCP_WND_DEBUG LWIP_DBG_OFF
#define TCP_FR_DEBUG LWIP_DBG_OFF
#define TCP_QLEN_DEBUG LWIP_DBG_OFF
#define TCP_RST_DEBUG LWIP_DBG_OFF
#endif
#define LWIP_DBG_TYPES_ON (LWIP_DBG_ON|LWIP_DBG_TRACE|LWIP_DBG_STATE|LWIP_DBG_FRESH|LWIP_DBG_HALT)
/* ---------- Memory options ---------- */
/* MEM_ALIGNMENT: should be set to the alignment of the CPU for which
lwIP is compiled. 4 byte alignment -> define MEM_ALIGNMENT to 4, 2
byte alignment -> define MEM_ALIGNMENT to 2. */
/* MSVC port: intel processors don't need 4-byte alignment,
but are faster that way! */
#define MEM_ALIGNMENT 4U
/* MEM_SIZE: the size of the heap memory. If the application will send
a lot of data that needs to be copied, this should be set high. */
#define MEM_SIZE 1024000
/* MEMP_NUM_PBUF: the number of memp struct pbufs. If the application
sends a lot of data out of ROM (or other static memory), this
should be set high. */
#define MEMP_NUM_PBUF 1600
/* MEMP_NUM_RAW_PCB: the number of UDP protocol control blocks. One
per active RAW "connection". */
#define MEMP_NUM_RAW_PCB 3
/* MEMP_NUM_UDP_PCB: the number of UDP protocol control blocks. One
per active UDP "connection". */
#define MEMP_NUM_UDP_PCB 8
/* MEMP_NUM_TCP_PCB: the number of simulatenously active TCP
connections. */
#define MEMP_NUM_TCP_PCB 1000
/* MEMP_NUM_TCP_PCB_LISTEN: the number of listening TCP
connections. */
#define MEMP_NUM_TCP_PCB_LISTEN 80
/* MEMP_NUM_TCP_SEG: the number of simultaneously queued TCP
segments. */
#define MEMP_NUM_TCP_SEG 1600
/* MEMP_NUM_SYS_TIMEOUT: the number of simulateously active
timeouts. */
#define MEMP_NUM_SYS_TIMEOUT 300
/* The following four are used only with the sequential API and can be
set to 0 if the application only will use the raw API. */
/* MEMP_NUM_NETBUF: the number of struct netbufs. */
#define MEMP_NUM_NETBUF 200
/* MEMP_NUM_NETCONN: the number of struct netconns. */
#define MEMP_NUM_NETCONN 1000
/* MEMP_NUM_TCPIP_MSG_*: the number of struct tcpip_msg, which is used
for sequential API communication and incoming packets. Used in
src/api/tcpip.c. */
#define MEMP_NUM_TCPIP_MSG_API 1600
#define MEMP_NUM_TCPIP_MSG_INPKT 1600
/* ---------- Pbuf options ---------- */
/* PBUF_POOL_SIZE: the number of buffers in the pbuf pool. */
#define PBUF_POOL_SIZE 10000
/* PBUF_POOL_BUFSIZE: the size of each pbuf in the pbuf pool. */
#define PBUF_POOL_BUFSIZE 2048
/** SYS_LIGHTWEIGHT_PROT
* define SYS_LIGHTWEIGHT_PROT in lwipopts.h if you want inter-task protection
* for certain critical regions during buffer allocation, deallocation and memory
* allocation and deallocation.
*/
#define SYS_LIGHTWEIGHT_PROT (NO_SYS==0)
/* ---------- TCP options ---------- */
#define LWIP_TCP 1
#define TCP_TTL 255
#define LWIP_ALTCP (LWIP_TCP)
#ifdef LWIP_HAVE_MBEDTLS
#define LWIP_ALTCP_TLS (LWIP_TCP)
#define LWIP_ALTCP_TLS_MBEDTLS (LWIP_TCP)
#endif
/* Controls if TCP should queue segments that arrive out of
order. Define to 0 if your device is low on memory. */
#define TCP_QUEUE_OOSEQ 1
/* TCP Maximum segment size. */
#define TCP_MSS 1024
/* TCP sender buffer space (bytes). */
#define TCP_SND_BUF 65534 /* Match TCP_WND. */
/* TCP sender buffer space (pbufs). This must be at least = 2 *
TCP_SND_BUF/TCP_MSS for things to work. */
#define TCP_SND_QUEUELEN (4 * TCP_SND_BUF/TCP_MSS)
/* TCP writable space (bytes). This must be less than or equal
to TCP_SND_BUF. It is the amount of space which must be
available in the tcp snd_buf for select to return writable */
#define TCP_SNDLOWAT (TCP_SND_BUF/8)
/* TCP receive window. */
#define TCP_WND 65534 /* Avoid wrap. */
/* Maximum number of retransmissions of data segments. */
#define TCP_MAXRTX 12
/* Maximum number of retransmissions of SYN segments. */
#define TCP_SYNMAXRTX 4
/* ---------- ARP options ---------- */
#define LWIP_ARP 1
#define ARP_TABLE_SIZE 0
#define ARP_QUEUEING 1
/* ---------- IP options ---------- */
/* Define IP_FORWARD to 1 if you wish to have the ability to forward
IP packets across network interfaces. If you are going to run lwIP
on a device with only one network interface, define this to 0. */
#define IP_FORWARD 0
/* IP reassembly and segmentation.These are orthogonal even
* if they both deal with IP fragments */
#define IP_REASSEMBLY 1
#define IP_REASS_MAX_PBUFS (10 * ((1500 + PBUF_POOL_BUFSIZE - 1) / PBUF_POOL_BUFSIZE))
#define MEMP_NUM_REASSDATA IP_REASS_MAX_PBUFS
#define IP_FRAG 1
#define IPV6_FRAG_COPYHEADER 1
/* ---------- ICMP options ---------- */
#define ICMP_TTL 255
/* ---------- DHCP options ---------- */
/* Define LWIP_DHCP to 1 if you want DHCP configuration of
interfaces. */
#define LWIP_DHCP LWIP_UDP
/* 1 if you want to do an ARP check on the offered address
(recommended). */
#define DHCP_DOES_ARP_CHECK (LWIP_DHCP)
/* ---------- AUTOIP options ------- */
#define LWIP_AUTOIP (LWIP_DHCP)
#define LWIP_DHCP_AUTOIP_COOP (LWIP_DHCP && LWIP_AUTOIP)
/* ---------- UDP options ---------- */
#define LWIP_UDP 0
#define LWIP_UDPLITE LWIP_UDP
#define UDP_TTL 255
/* ---------- RAW options ---------- */
#define LWIP_RAW 0
/* ---------- Statistics options ---------- */
#define LWIP_STATS 0
#define LWIP_STATS_DISPLAY 0
#if LWIP_STATS
#define LINK_STATS 1
#define IP_STATS 1
#define ICMP_STATS 1
#define IGMP_STATS 1
#define IPFRAG_STATS 1
#define UDP_STATS 1
#define TCP_STATS 1
#define MEM_STATS 1
#define MEMP_STATS 1
#define PBUF_STATS 1
#define SYS_STATS 1
#endif /* LWIP_STATS */
/* ---------- NETBIOS options ---------- */
#define LWIP_NETBIOS_RESPOND_NAME_QUERY 0
/* ---------- PPP options ---------- */
#define PPP_SUPPORT 0 /* Set > 0 for PPP */
#if PPP_SUPPORT
#define NUM_PPP 1 /* Max PPP sessions. */
/* Select modules to enable. Ideally these would be set in the makefile but
* we're limited by the command line length so you need to modify the settings
* in this file.
*/
#define PPPOE_SUPPORT 1
#define PPPOS_SUPPORT 1
#define PAP_SUPPORT 1 /* Set > 0 for PAP. */
#define CHAP_SUPPORT 1 /* Set > 0 for CHAP. */
#define MSCHAP_SUPPORT 0 /* Set > 0 for MSCHAP */
#define CBCP_SUPPORT 0 /* Set > 0 for CBCP (NOT FUNCTIONAL!) */
#define CCP_SUPPORT 0 /* Set > 0 for CCP */
#define VJ_SUPPORT 0 /* Set > 0 for VJ header compression. */
#define MD5_SUPPORT 1 /* Set > 0 for MD5 (see also CHAP) */
#endif /* PPP_SUPPORT */
#endif /* LWIP_OPTTEST_FILE */
/* The following defines must be done even in OPTTEST mode: */
#if !defined(NO_SYS) || !NO_SYS /* default is 0 */
#if 0
void sys_check_core_locking(void);
#define LWIP_ASSERT_CORE_LOCKED() sys_check_core_locking()
#endif
#endif
#ifndef LWIP_PLATFORM_ASSERT
#if 0
/* Define LWIP_PLATFORM_ASSERT to something to catch missing stdio.h includes */
void lwip_example_app_platform_assert(const char *msg, int line, const char *file);
#define LWIP_PLATFORM_ASSERT(x) lwip_example_app_platform_assert(x, __LINE__, __FILE__)
#endif
#endif
#endif /* LWIP_LWIPOPTS_H */

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/*
* Copyright (c) 2023 Penn Mackintosh <penn@pennmack.co.uk>
* Adapted from [ocproxy](https://github.com/cernekee/ocproxy) to use upgrade LwIP, remove LDAP functionality
* Copyright (c) 2016 Google Inc.
* Copyright (c) 2012-2014 David Edmondson <dme@dme.org>
* Copyright (c) 2012-2014 Kevin Cernekee <cernekee@gmail.com>
* 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. 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.
*/
#define _GNU_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <getopt.h>
#include <signal.h>
#include <stdarg.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/uio.h>
#include <event2/event.h>
#include <event2/listener.h>
//#include "lwip/opt.h"
//#include "lwip/debug.h"
//#include "lwip/err.h"
//#include "lwip/init.h"
#include "lwip/ip.h"
#include "lwip/tcp.h"
#include "lwip/init.h"
//#include "lwip/dns.h"
//#include "lwip/netif.h"
//#include "lwip/stats.h"
//#include "lwip/sys.h"
//#include "lwip/tcp.h"
enum {
STATE_NEW = 0,
STATE_DNS,
STATE_CONNECTING,
STATE_DATA,
STATE_DEAD,
STATE_MAX
};
#define CONN_TYPE_REDIR 0
#define SOCKBUF_LEN 2048
#define FL_ACTIVATE 1
#define FL_DIE_ON_ERROR 2
#define MAX_IOVEC 128
#define MAX_CONN 1024
struct ocp_sock {
/* general */
int fd;
struct evconnlistener *listener;
struct event *ev;
struct tcp_pcb *tpcb;
int state;
int conn_type;
struct ocp_sock *next;
/* for TCP send/receive */
int done_len;
int lwip_blocked;
int sock_pos;
int sock_total;
char sockbuf[SOCKBUF_LEN];
/* for all listeners */
int lport;
char *bind_addr;
evconnlistener_cb listen_cb;
/* for port forwarding */
ip_addr_t rhost;
int rport;
/* for lwip_data_cb() */
struct netif *netif;
};
struct socks_auth {
u8_t ver;
u8_t n_methods;
u8_t methods;
} PACK_STRUCT_STRUCT;
struct socks_req {
u8_t ver;
u8_t cmd;
u8_t rsv;
u8_t atyp;
union {
struct {
u32_t dst_addr;
u16_t dst_port;
u8_t end;
} ipv4;
struct {
u8_t fqdn_len;
u8_t fqdn_name[255]; /* variable length */
u16_t port;
} fqdn;
} u;
} PACK_STRUCT_STRUCT;
struct socks_reply {
u8_t ver;
u8_t rep;
u8_t rsv;
u8_t atyp;
u32_t bnd_addr;
u16_t bnd_port;
} PACK_STRUCT_STRUCT;
static struct event_base *event_base;
static struct ocp_sock ocp_sock_pool[MAX_CONN];
static struct ocp_sock *ocp_sock_free_list;
static struct ocp_sock *ocp_sock_bind_list;
static int ocp_sock_used;
static int ocp_sock_max;
/* nonstatic debug cmd option, exported in lwipopts.h */
unsigned char debug_flags = 0;
static int allow_remote;
static int tcpdump_enabled;
static int got_sighup;
static int got_sigusr1;
static char *dns_domain;
static void start_connection(struct ocp_sock *s);
/**********************************************************************
* Utility functions / libevent wrappers
**********************************************************************/
static void die(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fflush(stdout);
vfprintf(stderr, fmt, ap);
va_end(ap);
exit(1);
}
static void warn(const char *fmt, ...)
{
va_list ap;
va_start(ap, fmt);
fflush(stdout);
fprintf(stderr, "warning: ");
vfprintf(stderr, fmt, ap);
va_end(ap);
}
static char *xstrdup(const char *s)
{
char *ret = strdup(s);
if (!ret)
die("out of memory\n");
return ret;
}
static int ocp_atoi(const char *s)
{
char *p;
long val = strtol(s, &p, 0);
if (!*s || *p)
die("invalid integer: '%s'\n", s);
return val;
}
static struct ocp_sock *ocp_sock_new(int fd, event_callback_fn cb, int flags)
{
struct ocp_sock *s;
s = ocp_sock_free_list;
if (!s) {
if (flags & FL_DIE_ON_ERROR)
die("%s: ran out of ocp_socks\n", __func__);
return NULL;
}
ocp_sock_free_list = s->next;
memset(s, 0, sizeof(*s));
ocp_sock_used++;
if (ocp_sock_used > ocp_sock_max)
ocp_sock_max = ocp_sock_used;
s->next = ocp_sock_bind_list;
ocp_sock_bind_list = s;
if (fd < 0)
return s;
s->fd = fd;
s->ev = event_new(event_base, fd, EV_READ, cb, s);
if (flags & FL_ACTIVATE)
event_add(s->ev, NULL);
return s;
}
static void ocp_sock_del(struct ocp_sock *s)
{
if (s->state == STATE_DNS) {
s->state = STATE_DEAD;
return;
}
close(s->fd);
if (s->tpcb) {
tcp_arg(s->tpcb, NULL);
tcp_close(s->tpcb);
}
event_free(s->ev);
memset(s, 0xdd, sizeof(*s));
s->next = ocp_sock_free_list;
ocp_sock_free_list = s;
ocp_sock_used--;
}
/**********************************************************************
* lwIP TCP<->socket TCP traffic
**********************************************************************/
/* Called when the local TCP socket has data available (or hung up) */
static void local_data_cb(evutil_socket_t fd, short what, void *ctx)
{
struct ocp_sock *s = ctx;
ssize_t len;
int try_len;
err_t err;
try_len = tcp_sndbuf(s->tpcb);
if (try_len > SOCKBUF_LEN)
try_len = SOCKBUF_LEN;
if (!try_len || tcp_sndqueuelen(s->tpcb) > (TCP_SND_QUEUELEN/2)) {
s->lwip_blocked = 1;
return;
}
len = read(s->fd, s->sockbuf, try_len);
if (len <= 0) {
ocp_sock_del(s);
return;
}
err = tcp_write(s->tpcb, s->sockbuf, len, TCP_WRITE_FLAG_COPY);
if (err == ERR_MEM)
die("%s: out of memory\n", __func__);
else if (err != ERR_OK)
warn("tcp_write returned %d\n", (int)err);
tcp_output(s->tpcb);
event_add(s->ev, NULL);
}
/* Called when lwIP has sent data to the VPN */
static err_t sent_cb(void *ctx, struct tcp_pcb *tpcb, u16_t len)
{
struct ocp_sock *s = ctx;
if (!s)
return ERR_OK;
if (s->lwip_blocked) {
s->lwip_blocked = 0;
event_add(s->ev, NULL);
}
return ERR_OK;
}
/* Called when lwIP has new TCP data from the VPN */
static err_t recv_cb(void *ctx, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
struct ocp_sock *s = ctx;
struct pbuf *first = p;
int offset;
ssize_t wlen;
if (!s)
return ERR_ABRT;
if (!p) {
ocp_sock_del(s);
return ERR_OK;
}
/*
* tcp_tmr() will call this function every 250ms with the same pbuf,
* if we refused data during the previous attempt. s->done_len
* will reflect the number of bytes we were able to send to the socket
* so far (if any).
*/
for (offset = s->done_len; p && offset >= p->len; offset -= p->len)
p = p->next;
for (; p; p = p->next) {
int try_len = p->len - offset;
wlen = write(s->fd, (char *)p->payload + offset, try_len);
offset = 0;
if (wlen < 0) {
ocp_sock_del(s);
return ERR_ABRT;
}
s->done_len += wlen;
tcp_recved(tpcb, wlen);
if (wlen < try_len)
return ERR_WOULDBLOCK;
}
/* if we got here, then the whole pbuf is done */
s->done_len = 0;
pbuf_free(first);
return ERR_OK;
}
/**********************************************************************
* SOCKS protocol
**********************************************************************/
/**********************************************************************
* Connection setup
**********************************************************************/
/* Called on lwIP TCP errors; used to detect connection failure */
static void tcp_err_cb(void *arg, err_t err)
{
struct ocp_sock *s = arg;
warn("%s: called with %d\n", __func__, (int) err);
if (s) {
s->tpcb = NULL;
ocp_sock_del(s);
}
}
/* Called when lwIP tcp_connect() is successful */
static err_t connect_cb(void *arg, struct tcp_pcb *tpcb, err_t err)
{
if (err != ERR_OK)
warn("%s: called with %d\n", __func__, (int) err);
struct ocp_sock *s = arg;
s->state = STATE_DATA;
event_add(s->ev, NULL);
tcp_recv(tpcb, recv_cb);
tcp_sent(tpcb, sent_cb);
return ERR_OK;
}
static void start_connection(struct ocp_sock *s)
{
struct tcp_pcb *tpcb;
err_t err;
s->state = STATE_CONNECTING;
tpcb = tcp_new();
if (!tpcb)
die("%s: out of memory\n", __func__);
tcp_nagle_disable(tpcb);
tcp_arg(tpcb, s);
tcp_recv(tpcb, NULL);
tcp_err(tpcb, tcp_err_cb);
s->tpcb = tpcb;
err = tcp_connect(tpcb, &s->rhost, s->rport, connect_cb);
if (err != ERR_OK) {
warn("%s: tcp_connect(%s:%d) returned %d\n", __func__, ipaddr_ntoa(&s->rhost), s->rport, (int) err);
}
}
/* Called upon connection to a local TCP socket */
static void new_conn_cb(struct evconnlistener *listener, evutil_socket_t fd,
struct sockaddr *address, int socklen, void *ctx)
{
struct ocp_sock *lsock = ctx, *s;
s = ocp_sock_new(fd, local_data_cb, 0);
if (!s) {
warn("too many connections\n");
return;
}
s->conn_type = lsock->conn_type;
s->rhost = lsock->rhost;
s->rport = lsock->rport;
start_connection(s);
}
/**********************************************************************
* lwIP<->VPN traffic
**********************************************************************/
static void vpn_conn_down(void)
{
printf("VPN connection has terminated\n");
event_base_loopbreak(event_base);
}
/* Called when the VPN sends us a raw IP packet destined for lwIP */
static void lwip_data_cb(evutil_socket_t fd, short what, void *ctx)
{
struct ocp_sock *s = ctx;
ssize_t len;
struct pbuf *p;
len = read(s->fd, s->sockbuf, SOCKBUF_LEN);
if (len <= 0) {
/* This might never happen, because s->fd is a DGRAM socket */
vpn_conn_down();
}
if ((p = pbuf_alloc(PBUF_RAW, len, PBUF_POOL)) != NULL) {
char *bufptr;
struct pbuf *q;
bufptr = s->sockbuf;
q = p;
while (len > 0) {
int copy = (len > q->len) ? q->len : len;
memcpy(q->payload, bufptr, copy);
len -= copy;
bufptr += copy;
q = q->next;
}
LINK_STATS_INC(link.recv);
s->netif->input(p, s->netif);
} else
warn("%s: could not allocate pbuf\n", __func__);
event_add(s->ev, NULL);
}
/* Called when lwIP has data to send up to the VPN */
static err_t lwip_data_out(struct netif *netif, struct pbuf *p, const ip4_addr_t *ipaddr)
{
struct ocp_sock *s = netif->state;
int i = 0, total = 0;
ssize_t ret;
struct iovec iov[MAX_IOVEC];
for (; p; p = p->next) {
if (i >= MAX_IOVEC) {
warn("%s: too many chunks, dropping packet\n", __func__);
return ERR_OK;
}
iov[i].iov_base = p->payload;
iov[i++].iov_len = p->len;
total += p->len;
}
ret = writev(s->fd, iov, i);
if (ret < 0) {
if (errno == ECONNREFUSED || errno == ENOTCONN)
vpn_conn_down();
else
LINK_STATS_INC(link.drop);
} else if (ret != total)
LINK_STATS_INC(link.lenerr);
else
LINK_STATS_INC(link.xmit);
return ERR_OK;
}
/**********************************************************************
* Periodic tasks
**********************************************************************/
static void handle_sig(int sig)
{
if (sig == SIGHUP)
got_sighup = 1;
else if (sig == SIGUSR1)
got_sigusr1 = 1;
}
static void new_periodic_event(event_callback_fn cb, void *arg, int timeout_ms)
{
struct timeval tv;
struct event *ev;
tv.tv_sec = timeout_ms / 1000;
tv.tv_usec = 1000 * (timeout_ms % 1000);
ev = event_new(event_base, -1, EV_PERSIST, cb, arg);
if (!ev)
die("can't create new periodic event\n");
evtimer_add(ev, &tv);
}
static void cb_housekeeping(evutil_socket_t fd, short what, void *ctx)
{
int *vpnfd = ctx;
/*
* OpenConnect will ignore 0-byte datagrams if it's alive, but
* we'll get ECONNREFUSED if the peer has died.
*/
if (write(*vpnfd, vpnfd, 0) < 0 &&
(errno == ECONNREFUSED || errno == ENOTCONN))
vpn_conn_down();
else if (got_sighup)
vpn_conn_down();
if (got_sigusr1) {
LINK_STATS_DISPLAY();
MEM_STATS_DISPLAY();
printf("open connections: %d / %d, max %d\n",
ocp_sock_used, MAX_CONN, ocp_sock_max);
got_sigusr1 = 0;
}
}
/**********************************************************************
* Program initialization
**********************************************************************/
static err_t init_oc_netif(struct netif *netif)
{
netif->name[0] = 'u';
netif->name[1] = 'n';
netif->output = lwip_data_out;
return ERR_OK;
}
static void bind_all_listeners(void)
{
struct ocp_sock *s;
struct sockaddr_in sock;
for (s = ocp_sock_bind_list; s; s = s->next) {
if (!s->listen_cb)
continue;
if (s->lport < 1 || s->lport > 65535)
die("invalid port number: %d\n", s->lport);
memset(&sock, 0, sizeof(sock));
sock.sin_port = htons(s->lport);
sock.sin_family = AF_INET;
if (s->bind_addr) {
/*
* TODO: support IPv6 and multiple listening sockets
* per hostname
*/
if (!inet_aton(s->bind_addr, &sock.sin_addr))
die("can't parse IP: '%s'\n", s->bind_addr);
} else {
sock.sin_addr.s_addr = htonl(allow_remote ?
INADDR_ANY : INADDR_LOOPBACK);
}
s->listener = evconnlistener_new_bind(event_base, s->listen_cb,
s, LEV_OPT_CLOSE_ON_FREE|LEV_OPT_REUSEABLE, -1,
(struct sockaddr *)&sock, sizeof(sock));
if (!s->listener)
die("can't set up listener on port %d/tcp\n", s->lport);
}
}
static struct ocp_sock *new_listener(int port, evconnlistener_cb cb)
{
struct ocp_sock *s;
s = ocp_sock_new(-1, NULL, FL_DIE_ON_ERROR);
s->lport = port;
s->listen_cb = cb;
return s;
}
static void fwd_add(const char *opt)
{
char *str = xstrdup(opt), *tmp = str, *p;
int lport;
struct ocp_sock *s;
p = strsep(&str, ":");
if (!str)
goto bad;
lport = ocp_atoi(p);
p = strsep(&str, ":");
if (!str)
goto bad;
s = new_listener(lport, new_conn_cb);
struct addrinfo *addrinfo;
int ret = getaddrinfo(p, NULL, NULL, &addrinfo);
if (ret != 0) {
die("getaddrinfo: %s\n", gai_strerror(ret));
}
ip_addr_t addr;
if (addrinfo->ai_addr->sa_family == AF_INET6) {
struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) addrinfo->ai_addr;
//addr.u_addr.ip6.zone = addr6->sin6_scope_id;
addr.u_addr.ip6.addr[0] =
addr6->sin6_addr.s6_addr[0] << 24 |
addr6->sin6_addr.s6_addr[1] << 16 |
addr6->sin6_addr.s6_addr[2] << 8 |
addr6->sin6_addr.s6_addr[3] << 0;
addr.u_addr.ip6.addr[1] =
addr6->sin6_addr.s6_addr[4] << 24 |
addr6->sin6_addr.s6_addr[5] << 16 |
addr6->sin6_addr.s6_addr[6] << 8 |
addr6->sin6_addr.s6_addr[7] << 0;
addr.u_addr.ip6.addr[2] =
addr6->sin6_addr.s6_addr[8] << 24 |
addr6->sin6_addr.s6_addr[9] << 16 |
addr6->sin6_addr.s6_addr[10] << 8 |
addr6->sin6_addr.s6_addr[11] << 0;
addr.u_addr.ip6.addr[3] =
addr6->sin6_addr.s6_addr[12] << 24 |
addr6->sin6_addr.s6_addr[13] << 16 |
addr6->sin6_addr.s6_addr[14] << 8 |
addr6->sin6_addr.s6_addr[15] << 0;
} else {
struct sockaddr_in *addr4 = (struct sockaddr_in *) addrinfo->ai_addr;
addr.u_addr.ip4.addr = addr4->sin_addr.s_addr;
}
s->rhost = addr;
s->rport = ocp_atoi(str);
s->conn_type = CONN_TYPE_REDIR;
if (s->rport <= 0)
die("Remote port must be a positive integer\n");
free(tmp);
return;
bad:
die("Invalid port forward specifier: '%s'\n", opt);
}
static struct option longopts[] = {
{ "ip", 1, NULL, 'I' },
{ "mtu", 1, NULL, 'M' },
{ "dns", 1, NULL, 'd' },
{ "domain", 1, NULL, 'o' },
{ "localfw", 1, NULL, 'L' },
{ "dynfw", 1, NULL, 'D' },
{ "allow-remote", 0, NULL, 'g' },
{ "verbose", 0, NULL, 'v' },
{ "tcpdump", 0, NULL, 'T' },
{ NULL }
};
int main(int argc, char **argv)
{
int opt, i, vpnfd;
char *str;
char *ip_str, *mtu_str, *dns_str;
ip_addr_t ip, netmask, gw, dns;
struct ocp_sock *s;
struct netif netif;
ip_str = mtu_str = dns_str = NULL;
ocp_sock_free_list = &ocp_sock_pool[0];
for (i = 1; i < MAX_CONN; i++)
ocp_sock_pool[i - 1].next = &ocp_sock_pool[i];
event_base = event_base_new();
if (!event_base)
die("can't initialize libevent\n");
str = getenv("VPNFD");
if (!str)
die("VPNFD is not set, aborting\n");
vpnfd = ocp_atoi(str);
/* try to set the IP configuration from the environment, first */
ip_str = getenv("INTERNAL_IP4_ADDRESS");
mtu_str = getenv("INTERNAL_IP4_MTU");
dns_domain = getenv("CISCO_DEF_DOMAIN");
str = getenv("INTERNAL_IP4_DNS");
if (str) {
char *p;
/* this could contain many addresses; just use the first one */
dns_str = xstrdup(str);
p = strchr(dns_str, ' ');
if (p)
*p = 0;
}
/* override with command line options */
while ((opt = getopt_long(argc, argv,
"I:M:d:o:D:k:gL:vT", longopts, NULL)) != -1) {
switch (opt) {
case 'I':
ip_str = optarg;
break;
case 'M':
mtu_str = optarg;
break;
case 'd':
dns_str = optarg;
break;
case 'o':
dns_domain = optarg;
break;
case 'g':
allow_remote = 1;
break;
case 'L':
fwd_add(optarg);
break;
case 'v':
debug_flags = LWIP_DBG_ON | LWIP_DBG_TRACE |
LWIP_DBG_STATE | LWIP_DBG_FRESH |
LWIP_DBG_HALT;
break;
case 'T':
tcpdump_enabled = 1;
break;
default:
die("unknown option: %c\n", opt);
}
}
if (!ip_str || !mtu_str)
die("missing -I or -M\n");
if (!ipaddr_aton(ip_str, &ip))
die("Invalid IP address: '%s'\n", ip_str);
/* Debugging help. */
signal(SIGHUP, handle_sig);
signal(SIGUSR1, handle_sig);
signal(SIGPIPE, SIG_IGN);
setlinebuf(stdout);
setlinebuf(stderr);
/* Set up lwIP interface */
s = ocp_sock_new(vpnfd, lwip_data_cb, FL_ACTIVATE | FL_DIE_ON_ERROR);
memset(&netif, 0, sizeof(netif));
s->netif = &netif;
lwip_init();
ip_addr_set_zero(&netmask);
ip_addr_set_zero(&gw);
netif_add(&netif, &ip.u_addr.ip4, &netmask.u_addr.ip4, &gw.u_addr.ip4, s, init_oc_netif, ip_input);
netif.mtu = ocp_atoi(mtu_str);
netif_set_default(&netif);
netif_set_up(&netif);
netif_set_link_up(&netif);
/* bind after all options have been parsed (especially -g) */
bind_all_listeners();
new_periodic_event(cb_housekeeping, &vpnfd, 1000);
event_base_dispatch(event_base);
return 0;
}