BadVPN – Rev 1
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/**
* @file
* Application layered TCP connection API (to be used from TCPIP thread)\n
* This interface mimics the tcp callback API to the application while preventing
* direct linking (much like virtual functions).
* This way, an application can make use of other application layer protocols
* on top of TCP without knowing the details (e.g. TLS, proxy connection).
*
* This file contains the base implementation calling into tcp.
*/
/*
* Copyright (c) 2017 Simon Goldschmidt
* 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: Simon Goldschmidt <goldsimon@gmx.de>
*
*/
#include "lwip/opt.h"
#if LWIP_ALTCP /* don't build if not configured for use in lwipopts.h */
#include "lwip/altcp.h"
#include "lwip/altcp_tcp.h"
#include "lwip/priv/altcp_priv.h"
#include "lwip/tcp.h"
#include "lwip/mem.h"
#include <string.h>
#define ALTCP_TCP_ASSERT_CONN(conn) LWIP_ASSERT("conn->inner_conn == NULL", (conn)->inner_conn == NULL)
#define ALTCP_TCP_ASSERT_CONN_PCB(conn, tpcb) do { \
LWIP_ASSERT("pcb mismatch", (conn)->state == tpcb); \
ALTCP_TCP_ASSERT_CONN(conn); } while(0)
/* Variable prototype, the actual declaration is at the end of this file
since it contains pointers to static functions declared here */
extern const struct altcp_functions altcp_tcp_functions;
static void altcp_tcp_setup(struct altcp_pcb *conn, struct tcp_pcb *tpcb);
/* callback functions for TCP */
static err_t
altcp_tcp_accept(void *arg, struct tcp_pcb *new_tpcb, err_t err)
{
struct altcp_pcb *listen_conn = (struct altcp_pcb *)arg;
if (listen_conn && listen_conn->accept) {
/* create a new altcp_conn to pass to the next 'accept' callback */
struct altcp_pcb *new_conn = altcp_alloc();
if (new_conn == NULL) {
return ERR_MEM;
}
altcp_tcp_setup(new_conn, new_tpcb);
return listen_conn->accept(listen_conn->arg, new_conn, err);
}
return ERR_ARG;
}
static err_t
altcp_tcp_connected(void *arg, struct tcp_pcb *tpcb, err_t err)
{
struct altcp_pcb *conn = (struct altcp_pcb *)arg;
if (conn) {
ALTCP_TCP_ASSERT_CONN_PCB(conn, tpcb);
if (conn->connected) {
return conn->connected(conn->arg, conn, err);
}
}
return ERR_OK;
}
static err_t
altcp_tcp_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err)
{
struct altcp_pcb *conn = (struct altcp_pcb *)arg;
if (conn) {
ALTCP_TCP_ASSERT_CONN_PCB(conn, tpcb);
if (conn->recv) {
return conn->recv(conn->arg, conn, p, err);
}
}
if (p != NULL) {
/* prevent memory leaks */
pbuf_free(p);
}
return ERR_OK;
}
static err_t
altcp_tcp_sent(void *arg, struct tcp_pcb *tpcb, u16_t len)
{
struct altcp_pcb *conn = (struct altcp_pcb *)arg;
if (conn) {
ALTCP_TCP_ASSERT_CONN_PCB(conn, tpcb);
if (conn->sent) {
return conn->sent(conn->arg, conn, len);
}
}
return ERR_OK;
}
static err_t
altcp_tcp_poll(void *arg, struct tcp_pcb *tpcb)
{
struct altcp_pcb *conn = (struct altcp_pcb *)arg;
if (conn) {
ALTCP_TCP_ASSERT_CONN_PCB(conn, tpcb);
if (conn->poll) {
return conn->poll(conn->arg, conn);
}
}
return ERR_OK;
}
static void
altcp_tcp_err(void *arg, err_t err)
{
struct altcp_pcb *conn = (struct altcp_pcb *)arg;
if (conn) {
conn->state = NULL; /* already freed */
if (conn->err) {
conn->err(conn->arg, err);
}
altcp_free(conn);
}
}
/* setup functions */
static void
altcp_tcp_remove_callbacks(struct tcp_pcb *tpcb)
{
tcp_arg(tpcb, NULL);
tcp_recv(tpcb, NULL);
tcp_sent(tpcb, NULL);
tcp_err(tpcb, NULL);
tcp_poll(tpcb, NULL, tpcb->pollinterval);
}
static void
altcp_tcp_setup_callbacks(struct altcp_pcb *conn, struct tcp_pcb *tpcb)
{
tcp_arg(tpcb, conn);
tcp_recv(tpcb, altcp_tcp_recv);
tcp_sent(tpcb, altcp_tcp_sent);
tcp_err(tpcb, altcp_tcp_err);
/* tcp_poll is set when interval is set by application */
/* listen is set totally different :-) */
}
static void
altcp_tcp_setup(struct altcp_pcb *conn, struct tcp_pcb *tpcb)
{
altcp_tcp_setup_callbacks(conn, tpcb);
conn->state = tpcb;
conn->fns = &altcp_tcp_functions;
}
struct altcp_pcb *
altcp_tcp_new_ip_type(u8_t ip_type)
{
struct altcp_pcb *ret = altcp_alloc();
if (ret != NULL) {
struct tcp_pcb *tpcb = tcp_new_ip_type(ip_type);
if (tpcb != NULL) {
altcp_tcp_setup(ret, tpcb);
} else {
/* tcp_pcb allocation failed -> free the altcp_pcb too */
altcp_free(ret);
ret = NULL;
}
}
return ret;
}
struct altcp_pcb *
altcp_tcp_wrap(struct tcp_pcb *tpcb)
{
if (tpcb != NULL) {
struct altcp_pcb *ret = altcp_alloc();
if (ret != NULL) {
altcp_tcp_setup(ret, tpcb);
return ret;
}
}
return NULL;
}
/* "virtual" functions calling into tcp */
static void
altcp_tcp_set_poll(struct altcp_pcb *conn, u8_t interval)
{
if (conn != NULL) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
tcp_poll(pcb, altcp_tcp_poll, interval);
}
}
static void
altcp_tcp_recved(struct altcp_pcb *conn, u16_t len)
{
if (conn != NULL) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
tcp_recved(pcb, len);
}
}
static err_t
altcp_tcp_bind(struct altcp_pcb *conn, const ip_addr_t *ipaddr, u16_t port)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_bind(pcb, ipaddr, port);
}
static err_t
altcp_tcp_connect(struct altcp_pcb *conn, const ip_addr_t *ipaddr, u16_t port, altcp_connected_fn connected)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
conn->connected = connected;
pcb = (struct tcp_pcb *)conn->state;
return tcp_connect(pcb, ipaddr, port, altcp_tcp_connected);
}
static struct altcp_pcb *
altcp_tcp_listen(struct altcp_pcb *conn, u8_t backlog, err_t *err)
{
struct tcp_pcb *pcb;
struct tcp_pcb *lpcb;
if (conn == NULL) {
return NULL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
lpcb = tcp_listen_with_backlog_and_err(pcb, backlog, err);
if (lpcb != NULL) {
conn->state = lpcb;
tcp_accept(lpcb, altcp_tcp_accept);
return conn;
}
return NULL;
}
static void
altcp_tcp_abort(struct altcp_pcb *conn)
{
if (conn != NULL) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
if (pcb) {
tcp_abort(pcb);
}
}
}
static err_t
altcp_tcp_close(struct altcp_pcb *conn)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
if (pcb) {
err_t err;
tcp_poll_fn oldpoll = pcb->poll;
altcp_tcp_remove_callbacks(pcb);
err = tcp_close(pcb);
if (err != ERR_OK) {
/* not closed, set up all callbacks again */
altcp_tcp_setup_callbacks(conn, pcb);
/* poll callback is not included in the above */
tcp_poll(pcb, oldpoll, pcb->pollinterval);
return err;
}
conn->state = NULL; /* unsafe to reference pcb after tcp_close(). */
}
altcp_free(conn);
return ERR_OK;
}
static err_t
altcp_tcp_shutdown(struct altcp_pcb *conn, int shut_rx, int shut_tx)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_shutdown(pcb, shut_rx, shut_tx);
}
static err_t
altcp_tcp_write(struct altcp_pcb *conn, const void *dataptr, u16_t len, u8_t apiflags)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_write(pcb, dataptr, len, apiflags);
}
static err_t
altcp_tcp_output(struct altcp_pcb *conn)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return ERR_VAL;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_output(pcb);
}
static u16_t
altcp_tcp_mss(struct altcp_pcb *conn)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return 0;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_mss(pcb);
}
static u16_t
altcp_tcp_sndbuf(struct altcp_pcb *conn)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return 0;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_sndbuf(pcb);
}
static u16_t
altcp_tcp_sndqueuelen(struct altcp_pcb *conn)
{
struct tcp_pcb *pcb;
if (conn == NULL) {
return 0;
}
ALTCP_TCP_ASSERT_CONN(conn);
pcb = (struct tcp_pcb *)conn->state;
return tcp_sndqueuelen(pcb);
}
static void
altcp_tcp_nagle_disable(struct altcp_pcb *conn)
{
if (conn && conn->state) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
tcp_nagle_disable(pcb);
}
}
static void
altcp_tcp_nagle_enable(struct altcp_pcb *conn)
{
if (conn && conn->state) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
tcp_nagle_enable(pcb);
}
}
static int
altcp_tcp_nagle_disabled(struct altcp_pcb *conn)
{
if (conn && conn->state) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
return tcp_nagle_disabled(pcb);
}
return 0;
}
static void
altcp_tcp_setprio(struct altcp_pcb *conn, u8_t prio)
{
if (conn != NULL) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
tcp_setprio(pcb, prio);
}
}
static void
altcp_tcp_dealloc(struct altcp_pcb *conn)
{
LWIP_UNUSED_ARG(conn);
ALTCP_TCP_ASSERT_CONN(conn);
/* no private state to clean up */
}
static err_t
altcp_tcp_get_tcp_addrinfo(struct altcp_pcb *conn, int local, ip_addr_t *addr, u16_t *port)
{
if (conn) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
return tcp_tcp_get_tcp_addrinfo(pcb, local, addr, port);
}
return ERR_VAL;
}
static ip_addr_t *
altcp_tcp_get_ip(struct altcp_pcb *conn, int local)
{
if (conn) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
if (pcb) {
if (local) {
return &pcb->local_ip;
} else {
return &pcb->remote_ip;
}
}
}
return NULL;
}
static u16_t
altcp_tcp_get_port(struct altcp_pcb *conn, int local)
{
if (conn) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
if (pcb) {
if (local) {
return pcb->local_port;
} else {
return pcb->remote_port;
}
}
}
return 0;
}
#ifdef LWIP_DEBUG
static enum tcp_state
altcp_tcp_dbg_get_tcp_state(struct altcp_pcb *conn)
{
if (conn) {
struct tcp_pcb *pcb = (struct tcp_pcb *)conn->state;
ALTCP_TCP_ASSERT_CONN(conn);
if (pcb) {
return pcb->state;
}
}
return CLOSED;
}
#endif
const struct altcp_functions altcp_tcp_functions = {
altcp_tcp_set_poll,
altcp_tcp_recved,
altcp_tcp_bind,
altcp_tcp_connect,
altcp_tcp_listen,
altcp_tcp_abort,
altcp_tcp_close,
altcp_tcp_shutdown,
altcp_tcp_write,
altcp_tcp_output,
altcp_tcp_mss,
altcp_tcp_sndbuf,
altcp_tcp_sndqueuelen,
altcp_tcp_nagle_disable,
altcp_tcp_nagle_enable,
altcp_tcp_nagle_disabled,
altcp_tcp_setprio,
altcp_tcp_dealloc,
altcp_tcp_get_tcp_addrinfo,
altcp_tcp_get_ip,
altcp_tcp_get_port
#ifdef LWIP_DEBUG
, altcp_tcp_dbg_get_tcp_state
#endif
};
#endif /* LWIP_ALTCP */