libplum (Port Lightweight and Universal Mapping) is a high-level library allowing to forward ports on Network Address Translators (NAT). It is written in C without dependencies and supports POSIX platforms (including GNU/Linux, Android, Apple macOS and iOS) and Microsoft Windows.

libplum has Node.js bindings, see node-portmapping.

Under the hood, it implements multiple protocols and automatically detects which one to use:

• Port Control Protocol (PCP, RFC6887)
• NAT Port Mapping Protocol (NAT-PMP, RFC6886)
• UPnP Internet Gateway Device Protocol (UPnP-IGD)

It also contains an integrated client for the DummyTLS service.

libplum is licensed under MPL 2.0, see LICENSE.

None!

#include "plum/plum.h"

plum_config_t config;
memset(&config, 0, sizeof(config));
config.log_level = PLUM_LOG_LEVEL_WARN;
plum_init(&config);

void mapping_callback(int id, plum_state_t state, const plum_mapping_t *mapping) {
    // Called from another thread
    if (state == PLUM_STATE_SUCCESS)
        printf("External address: %s:%hu\n", mapping->external_host, mapping->external_port);
}

plum_mapping_t mapping;
memset(&mapping, 0, sizeof(mapping));
mapping.protocol = PLUM_IP_PROTOCOL_TCP;
mapping.internal_port = 8000;
mapping.user_ptr = NULL;

int id = plum_create_mapping(&mapping, mapping_callback);

plum_destroy_mapping(id);

See example/main.c for a usage example.

$ git clone https://github.com/paullouisageneau/libplum.git
$ cd libplum

The CMake library targets libplum and libplum-static respectively correspond to the shared and static libraries. The default target will build the library and example.

$ cmake -B build
$ cd build
$ make -j2

$ cmake -B build -DCMAKE_TOOLCHAIN_FILE=/usr/share/mingw/toolchain-x86_64-w64-mingw32.cmake # replace with your toolchain file
$ cd build
$ make -j2

$ cmake -B build -G "NMake Makefiles"
$ cd build
$ nmake

$ make