lokinet/llarp/vpn/android.hpp
Thomas Winget 4c630e0437 Large collection of changes to make android work
- Previous android java and jni code updated to work, but with much love
  still needed to make it work nicely, e.g. handling when the VPN is
  turned off.

- DNS handling refactored to allow android to intercept and handle DNS
  requests as we can't set the system DNS to use a high port
  (and apparently Chrome ignores system DNS settings anyway)

- add packet router structure to allow separate handling of specific
  intercepted traffic, e.g. UDP traffic to port 53 gets handled by our
  DNS handler rather than being naively forwarded as exit traffic.

- For now, android lokinet is exit-only and hard-coded to use exit.loki
  as its exit.  The exit will be configurable before release, but
  allowing to not use exit-only mode is more of a challenge.

- some old gitignore remnants which were matching to things we don't
  want them to (and are no longer relevant) removed

- some minor changes to CI configuration
2021-03-02 13:18:22 -05:00

85 lines
1.6 KiB
C++

#pragma once
#include <stdio.h>
#include <unistd.h>
#include <ev/vpn.hpp>
#include <vpn/common.hpp>
#include <llarp.hpp>
namespace llarp::vpn
{
class AndroidInterface : public NetworkInterface
{
const int m_fd;
const InterfaceInfo m_Info; // likely 100% ignored on android, at least for now
public:
AndroidInterface(InterfaceInfo info, int fd) : m_fd(fd), m_Info(info)
{
if (m_fd == -1)
throw std::runtime_error(
"Error opening AndroidVPN layer FD: " + std::string{strerror(errno)});
}
virtual ~AndroidInterface()
{
if (m_fd != -1)
::close(m_fd);
}
int
PollFD() const override
{
return m_fd;
}
net::IPPacket
ReadNextPacket() override
{
net::IPPacket pkt;
const auto sz = read(m_fd, pkt.buf, sizeof(pkt.buf));
if (sz >= 0)
pkt.sz = std::min(sz, ssize_t{sizeof(pkt.buf)});
return pkt;
}
bool
WritePacket(net::IPPacket pkt) override
{
const auto sz = write(m_fd, pkt.buf, pkt.sz);
if (sz <= 0)
return false;
return sz == static_cast<ssize_t>(pkt.sz);
}
bool
HasNextPacket() override
{
return false;
}
std::string
IfName() const override
{
return m_Info.ifname;
}
};
class AndroidPlatform : public Platform
{
const int fd;
public:
AndroidPlatform(llarp::Context* ctx) : fd(ctx->androidFD)
{}
std::shared_ptr<NetworkInterface>
ObtainInterface(InterfaceInfo info) override
{
return std::make_shared<AndroidInterface>(std::move(info), fd);
}
};
} // namespace llarp::vpn