https://github.com/heiher/lwip
A lightweight IP stack.
https://github.com/heiher/lwip
tcp tun2socks udp
Last synced: 5 months ago
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A lightweight IP stack.
- Host: GitHub
- URL: https://github.com/heiher/lwip
- Owner: heiher
- License: other
- Created: 2019-09-25T09:49:16.000Z (over 5 years ago)
- Default Branch: master
- Last Pushed: 2024-09-08T00:51:55.000Z (8 months ago)
- Last Synced: 2024-09-08T01:39:10.503Z (8 months ago)
- Topics: tcp, tun2socks, udp
- Language: C
- Homepage: https://savannah.nongnu.org/projects/lwip
- Size: 1.07 MB
- Stars: 20
- Watchers: 5
- Forks: 5
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: License
Awesome Lists containing this project
README
# LwIP
[](https://github.com/heiher/lwip)
This is a branch of liblwip with a simple build system.
## Features
* UDP: Allow receiving packets are not destined to localhost.
* TCP: Allow accepting connections are not destined to localhost.
## Examples
### TCP
```c
static void
gateway_init(void)
{
// Init netif
netif_set_up (&netif);
netif_set_link_up (&netif);
netif_set_default (&netif);
// Allow to pretend TCP on this netif
netif_set_flags (&netif, NETIF_FLAG_PRETEND_TCP);
tcp = tcp_new_ip_type (IPADDR_TYPE_ANY);
// Bind TCP to netif first
tcp_bind_netif (tcp, &netif);
// Bind to accept incoming connections to other hosts
tcp_bind (tcp, NULL, 0);
tcp_listen (tcp);
tcp_accept (tcp, tcp_accept_handler);
}
static err_t
tcp_accept_handler (void *arg, struct tcp_pcb *pcb, err_t err)
{
// Accept new TCP connection
// @pcb->local_ip: The real destination address
// @pcb->local_port: The real destination port
// @pcb->remote_ip: The real source address
// @pcb->remote_port: The real source port
}
```
### UDP
```c
static void
gateway_init(void)
{
// Init netif
netif_set_up (&netif);
netif_set_link_up (&netif);
netif_set_default (&netif);
// Allow to pretend UDP on this netif
netif_set_flags (&netif, NETIF_FLAG_PRETEND_UDP);
udp = udp_new_ip_type (IPADDR_TYPE_ANY);
// Bind TCP to netif first
udp_bind_netif (udp, &netif);
// Bind to receive packets to other hosts
udp_bind (udp, NULL, 0);
udp_recv (udp, udp_accept_handler, NULL);
}
static void
udp_accept_handler (void *arg, struct udp_pcb *pcb, struct pbuf *p,
const ip_addr_t *addr, u16_t port)
{
// Similar to TCP accept, receive packets on new UDP PCB.
// @pcb: An new UDP PCB for sending and receiving.
// @p: Unused
// @addr: Unused
// @port: Unused
udp_recv (pcb, udp_recv_handler, NULL);
}
static void
udp_recv_handler (void *arg, struct udp_pcb *pcb, struct pbuf *p,
const ip_addr_t *addr, u16_t port)
{
// Receive UDP packets
// @pcb->local_ip: The real destination address
// @pcb->local_port: The real destination port
// @pcb->remote_ip: The real source address
// @pcb->remote_port: The real source port
// @addr: Unused
// @port: Unused
// Send with source address
udp_sendfrom (pcb, p, real_src_ip, real_src_port);
pbuf_free (p);
}
```
## How to Build
**Unix**:
```bash
git clone https://gitlab.com/hev/lwip
cd lwip
make
```
**Android**:
```bash
mkdir lwip
cd lwip
git clone https://gitlab.com/hev/lwip jni
ndk-build
```
**Windows**:
```bash
git clone https://gitlab.com/hev/lwip
cd lwip
make CROSS_PREFIX=x86_64-w64-mingw32-
```
## Upstream
https://savannah.nongnu.org/projects/lwip
[PROJECT_URL]: https://gitlab.com/hev/lwip/commits/master
[PIPELINE_STATUS]: https://gitlab.com/hev/lwip/badges/master/pipeline.svg