tenfourfox/media/mtransport/stun_udp_socket_filter.cpp
Cameron Kaiser c9b2922b70 hello FPR
2017-04-19 00:56:45 -07:00

240 lines
7.6 KiB
C++

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
#include <string>
#include <set>
extern "C" {
#include "nr_api.h"
#include "transport_addr.h"
#include "stun.h"
}
#include "mozilla/Attributes.h"
#include "mozilla/net/DNS.h"
#include "stun_udp_socket_filter.h"
#include "nr_socket_prsock.h"
#if defined(MOZILLA_XPCOMRT_API)
#include "mozilla/Module.h"
#include "mozilla/ModuleUtils.h"
#endif
namespace {
class NetAddrCompare {
public:
bool operator()(const mozilla::net::NetAddr& lhs,
const mozilla::net::NetAddr& rhs) const {
if (lhs.raw.family != rhs.raw.family) {
return lhs.raw.family < rhs.raw.family;
}
switch (lhs.raw.family) {
case AF_INET:
if (lhs.inet.port != rhs.inet.port) {
return lhs.inet.port < rhs.inet.port;
}
return lhs.inet.ip < rhs.inet.ip;
case AF_INET6:
if (lhs.inet6.port != rhs.inet6.port) {
return lhs.inet6.port < rhs.inet6.port;
}
return memcmp(&lhs.inet6.ip, &rhs.inet6.ip, sizeof(lhs.inet6.ip)) < 0;
default:
MOZ_ASSERT(false);
}
return false;
}
};
class PendingSTUNRequest {
public:
PendingSTUNRequest(const mozilla::net::NetAddr& netaddr, const UINT12 &id)
: id_(id),
net_addr_(netaddr),
is_id_set_(true) {}
MOZ_IMPLICIT PendingSTUNRequest(const mozilla::net::NetAddr& netaddr)
: id_(),
net_addr_(netaddr),
is_id_set_(false) {}
bool operator<(const PendingSTUNRequest& rhs) const {
if (NetAddrCompare()(net_addr_, rhs.net_addr_)) {
return true;
}
if (NetAddrCompare()(rhs.net_addr_, net_addr_)) {
return false;
}
if (!is_id_set_ && !rhs.is_id_set_) {
// PendingSTUNRequest can be stored to set only when it has id,
// so comparing two PendingSTUNRequst without id is not going
// to happen.
MOZ_CRASH();
}
if (!(is_id_set_ && rhs.is_id_set_)) {
// one of operands doesn't have id, ignore the difference.
return false;
}
return memcmp(id_.octet, rhs.id_.octet, sizeof(id_.octet)) < 0;
}
private:
const UINT12 id_;
const mozilla::net::NetAddr net_addr_;
const bool is_id_set_;
};
class STUNUDPSocketFilter : public nsIUDPSocketFilter {
public:
STUNUDPSocketFilter()
: white_list_(),
pending_requests_() {}
// Allocated/freed and used on the PBackground IPC thread
NS_DECL_ISUPPORTS
NS_DECL_NSIUDPSOCKETFILTER
private:
virtual ~STUNUDPSocketFilter() {}
bool filter_incoming_packet(const mozilla::net::NetAddr *remote_addr,
const uint8_t *data,
uint32_t len);
bool filter_outgoing_packet(const mozilla::net::NetAddr *remote_addr,
const uint8_t *data,
uint32_t len);
std::set<mozilla::net::NetAddr, NetAddrCompare> white_list_;
std::set<PendingSTUNRequest> pending_requests_;
std::set<PendingSTUNRequest> response_allowed_;
};
NS_IMPL_ISUPPORTS(STUNUDPSocketFilter, nsIUDPSocketFilter)
NS_IMETHODIMP
STUNUDPSocketFilter::FilterPacket(const mozilla::net::NetAddr *remote_addr,
const uint8_t *data,
uint32_t len,
int32_t direction,
bool *result) {
switch (direction) {
case nsIUDPSocketFilter::SF_INCOMING:
*result = filter_incoming_packet(remote_addr, data, len);
break;
case nsIUDPSocketFilter::SF_OUTGOING:
*result = filter_outgoing_packet(remote_addr, data, len);
break;
default:
MOZ_CRASH("Unknown packet direction");
}
return NS_OK;
}
bool STUNUDPSocketFilter::filter_incoming_packet(const mozilla::net::NetAddr *remote_addr,
const uint8_t *data, uint32_t len) {
// Check white list
if (white_list_.find(*remote_addr) != white_list_.end()) {
return true;
}
// Check if we had sent any stun request to this destination. If we had sent a request
// to this host, we check the transaction id, and we can add this address to whitelist.
std::set<PendingSTUNRequest>::iterator it =
pending_requests_.find(PendingSTUNRequest(*remote_addr));
if (it != pending_requests_.end()) {
if (nr_is_stun_message(reinterpret_cast<UCHAR*>(const_cast<uint8_t*>(data)), len)) {
const nr_stun_message_header *msg = reinterpret_cast<const nr_stun_message_header*>(data);
// If it is a STUN response message and we can match its id with one of the pending
// requests, we can add this address into whitelist.
if (nr_is_stun_response_message(reinterpret_cast<UCHAR*>(const_cast<uint8_t*>(data)), len)) {
PendingSTUNRequest pending_req(*remote_addr, msg->id);
std::set<PendingSTUNRequest>::iterator it = pending_requests_.find(pending_req);
if (it != pending_requests_.end()) {
pending_requests_.erase(it);
response_allowed_.erase(pending_req);
white_list_.insert(*remote_addr);
}
} else {
// If it is a STUN message, but not a response message, we add it into response
// allowed list and allow outgoing filter to send a response back.
response_allowed_.insert(PendingSTUNRequest(*remote_addr, msg->id));
}
}
return true;
}
return false;
}
bool STUNUDPSocketFilter::filter_outgoing_packet(const mozilla::net::NetAddr *remote_addr,
const uint8_t *data, uint32_t len) {
// Check white list
if (white_list_.find(*remote_addr) != white_list_.end()) {
return true;
}
// Check if it is a stun packet. If yes, we put it into a pending list and wait for
// response packet.
if (nr_is_stun_request_message(reinterpret_cast<UCHAR*>(const_cast<uint8_t*>(data)), len)) {
const nr_stun_message_header *msg = reinterpret_cast<const nr_stun_message_header*>(data);
pending_requests_.insert(PendingSTUNRequest(*remote_addr, msg->id));
return true;
}
// If it is a stun response packet, and we had received the request before, we can
// allow it packet to pass filter.
if (nr_is_stun_response_message(reinterpret_cast<UCHAR*>(const_cast<uint8_t*>(data)), len)) {
const nr_stun_message_header *msg = reinterpret_cast<const nr_stun_message_header*>(data);
std::set<PendingSTUNRequest>::iterator it =
response_allowed_.find(PendingSTUNRequest(*remote_addr, msg->id));
if (it != response_allowed_.end()) {
return true;
}
}
return false;
}
} // anonymous namespace
NS_IMPL_ISUPPORTS(nsStunUDPSocketFilterHandler, nsIUDPSocketFilterHandler)
NS_IMETHODIMP nsStunUDPSocketFilterHandler::NewFilter(nsIUDPSocketFilter **result)
{
nsIUDPSocketFilter *ret = new STUNUDPSocketFilter();
if (!ret) {
return NS_ERROR_OUT_OF_MEMORY;
}
NS_ADDREF(*result = ret);
return NS_OK;
}
#if defined(MOZILLA_XPCOMRT_API)
NS_DEFINE_NAMED_CID(NS_STUN_UDP_SOCKET_FILTER_HANDLER_CID)
NS_GENERIC_FACTORY_CONSTRUCTOR(nsStunUDPSocketFilterHandler)
static const mozilla::Module::CIDEntry kCIDs[] = {
{ &kNS_STUN_UDP_SOCKET_FILTER_HANDLER_CID, false, nullptr, nsStunUDPSocketFilterHandlerConstructor },
{ nullptr }
};
static const mozilla::Module::ContractIDEntry kContracts[] = {
{ NS_STUN_UDP_SOCKET_FILTER_HANDLER_CONTRACTID, &kNS_STUN_UDP_SOCKET_FILTER_HANDLER_CID },
{ nullptr }
};
extern const mozilla::Module kStunUDPSocketFilterHandlerModule;
const mozilla::Module kStunUDPSocketFilterHandlerModule = {
mozilla::Module::kVersion,
kCIDs,
kContracts
};
#endif