static uint8_t incomingFromCryptoAuth(struct Message* message, struct Interface* iface)
{
struct Context* context = iface->receiverContext;
int layer = context->layer;
context->layer = INVALID_LAYER;
if (layer == INNER_LAYER) {
return incomingForMe(message, context);
} else if (layer == OUTER_LAYER) {
return incomingFromRouter(message, context);
}
assert(false);
}
static uint8_t incomingFromCryptoAuth(struct Message* message, struct Interface* iface)
{
struct Ducttape* context = iface->receiverContext;
int layer = context->layer;
context->layer = INVALID_LAYER;
if (layer == INNER_LAYER) {
return incomingForMe(message, context, CryptoAuth_getHerPublicKey(context->session));
} else if (layer == OUTER_LAYER) {
return incomingFromRouter(message, context);
}
Assert_true(false);
return 0;
}
/**
* Messages with content encrypted and header decrypted are sent here to be forwarded.
* they may come from us, or from another node and may be to us or to any other node.
* Message is aligned on the beginning of the ipv6 header.
*/
static inline int core(struct Message* message, struct Ducttape* context)
{
context->ip6Header = (struct Headers_IP6Header*) message->bytes;
if (isForMe(message, context)) {
Message_shift(message, -Headers_IP6Header_SIZE);
if (memcmp(context->routerAddress, context->ip6Header->sourceAddr, 16)) {
// triple encrypted
// This call goes to incomingForMe()
context->layer = INNER_LAYER;
context->session =
SessionManager_getSession(context->ip6Header->sourceAddr, NULL, context->sm);
return context->session->receiveMessage(message, context->session);
} else {
// double encrypted, inner layer plaintext.
// The session is still set from the router-to-router traffic and that is the one we use
// to determine the node's id.
return incomingForMe(message, context, CryptoAuth_getHerPublicKey(context->session));
}
}
if (context->ip6Header->hopLimit == 0) {
Log_debug(context->logger, "dropped message because hop limit has been exceeded.\n");
// TODO: send back an error message in response.
return Error_UNDELIVERABLE;
}
context->ip6Header->hopLimit--;
struct Address* ft = context->forwardTo;
context->forwardTo = NULL;
if (!ft) {
struct Node* bestNext =
RouterModule_lookup(context->ip6Header->destinationAddr, context->routerModule);
if (bestNext) {
ft = &bestNext->address;
}
}
if (ft) {
#ifdef Log_DEBUG
uint8_t nhAddr[60];
Address_print(nhAddr, ft);
if (memcmp(context->ip6Header->destinationAddr, ft->ip6.bytes, 16)) {
// Potentially forwarding for ourselves.
struct Address destination;
Bits_memcpyConst(destination.ip6.bytes, context->ip6Header->destinationAddr, 16);
uint8_t ipAddr[40];
Address_printIp(ipAddr, &destination);
Log_debug2(context->logger, "Forwarding data to %s via %s\n", ipAddr, nhAddr);
} else {
// Definitely forwarding on behalf of someone else.
Log_debug1(context->logger, "Forwarding data to %s (last hop)\n", nhAddr);
}
#endif
return sendToRouter(ft, message, context);
}
Log_debug(context->logger, "Dropped message because this node is the closest known "
"node to the destination.\n");
return Error_UNDELIVERABLE;
}
static int handleOutgoing(struct DHTMessage* dmessage,
void* vcontext)
{
struct Ducttape* context = (struct Ducttape*) vcontext;
struct Message message =
{ .length = dmessage->length, .bytes = (uint8_t*) dmessage->bytes, .padding = 512 };
Message_shift(&message, Headers_UDPHeader_SIZE);
struct Headers_UDPHeader* uh = (struct Headers_UDPHeader*) message.bytes;
uh->sourceAndDestPorts = 0;
uh->length_be = Endian_hostToBigEndian16(dmessage->length);
uh->checksum_be = 0;
uint16_t payloadLength = message.length;
Message_shift(&message, Headers_IP6Header_SIZE);
struct Headers_IP6Header* header = (struct Headers_IP6Header*) message.bytes;
header->versionClassAndFlowLabel = 0;
header->flowLabelLow_be = 0;
header->nextHeader = 17;
header->hopLimit = 0;
header->payloadLength_be = Endian_hostToBigEndian16(payloadLength);
Bits_memcpyConst(header->sourceAddr,
context->myAddr.ip6.bytes,
Address_SEARCH_TARGET_SIZE);
Bits_memcpyConst(header->destinationAddr,
dmessage->address->ip6.bytes,
Address_SEARCH_TARGET_SIZE);
context->ip6Header = header;
context->switchHeader = NULL;
sendToRouter(dmessage->address, &message, context);
return 0;
}
// Aligned on the beginning of the content.
static inline bool isRouterTraffic(struct Message* message, struct Headers_IP6Header* ip6)
{
if (ip6->nextHeader != 17 || ip6->hopLimit != 0) {
return false;
}
struct Headers_UDPHeader* uh = (struct Headers_UDPHeader*) message->bytes;
return message->length >= Headers_UDPHeader_SIZE
&& uh->sourceAndDestPorts == 0
&& (int) Endian_bigEndianToHost16(uh->length_be) == message->length - Headers_UDPHeader_SIZE;
}
/**
* Message which is for us, message is aligned on the beginning of the content.
* this is called from core() which calls through an interfaceMap.
*/
static inline uint8_t incomingForMe(struct Message* message,
struct Ducttape* context,
uint8_t herPubKey[32])
{
struct Address addr;
AddressCalc_addressForPublicKey(addr.ip6.bytes, herPubKey);
if (memcmp(addr.ip6.bytes, context->ip6Header->sourceAddr, 16)) {
#ifdef Log_DEBUG
uint8_t keyAddr[40];
Address_printIp(keyAddr, &addr);
Bits_memcpyConst(addr.ip6.bytes, context->ip6Header->sourceAddr, 16);
uint8_t srcAddr[40];
Address_printIp(srcAddr, &addr);
Log_debug2(context->logger,
"Dropped packet because source address is not same as key.\n"
" %s source addr\n"
" %s hash of key\n",
srcAddr,
keyAddr);
#endif
return Error_INVALID;
}
if (message->length == 0) {
#ifdef Log_WARN
uint8_t keyAddr[40];
uint8_t ipv6Hex[80];
Address_printIp(keyAddr, &addr);
Hex_encode(ipv6Hex, 80, (uint8_t*) context->ip6Header, 40);
Log_warn2(context->logger,
"Got ipv6 packet from %s which has no content!\nIPv6 Header: [%s]",
keyAddr, ipv6Hex);
#endif
return Error_INVALID;
}
if (isRouterTraffic(message, context->ip6Header)) {
// Shift off the UDP header.
Message_shift(message, -Headers_UDPHeader_SIZE);
addr.path = Endian_bigEndianToHost64(context->switchHeader->label_be);
Bits_memcpyConst(addr.key, herPubKey, 32);
return incomingDHT(message, &addr, context);
}
// RouterModule_addNode(&addr, context->routerModule);
if (!context->routerIf) {
Log_warn(context->logger,
"Dropping message because there is no router interface configured.\n");
return Error_UNDELIVERABLE;
}
// Now write a message to the TUN device.
// Need to move the ipv6 header forward up to the content because there's a crypto header
// between the ipv6 header and the content which just got eaten.
Message_shift(message, Headers_IP6Header_SIZE);
uint16_t sizeDiff = message->bytes - (uint8_t*)context->ip6Header;
if (sizeDiff) {
context->ip6Header->payloadLength_be =
Endian_hostToBigEndian16(
Endian_bigEndianToHost16(context->ip6Header->payloadLength_be) - sizeDiff);
memmove(message->bytes, context->ip6Header, Headers_IP6Header_SIZE);
}
context->routerIf->sendMessage(message, context->routerIf);
return Error_NONE;
}
uint8_t Ducttape_injectIncomingForMe(struct Message* message,
struct Ducttape* context,
uint8_t herPublicKey[32])
{
struct Headers_SwitchHeader sh;
Bits_memcpyConst(&sh, message->bytes, Headers_SwitchHeader_SIZE);
context->switchHeader = &sh;
Message_shift(message, -Headers_SwitchHeader_SIZE);
struct Headers_IP6Header ip6;
Bits_memcpyConst(&ip6, message->bytes, Headers_IP6Header_SIZE);
context->ip6Header = &ip6;
Message_shift(message, -Headers_IP6Header_SIZE);
return incomingForMe(message, context, herPublicKey);
}
/**
* Send a message to another switch.
* Switchheader will precede the message.
*/
static inline uint8_t sendToSwitch(struct Message* message,
struct Headers_SwitchHeader* destinationSwitchHeader,
struct Ducttape* context)
{
Message_shift(message, Headers_SwitchHeader_SIZE);
struct Headers_SwitchHeader* switchHeaderLocation =
(struct Headers_SwitchHeader*) message->bytes;
if (destinationSwitchHeader != switchHeaderLocation) {
memmove(message->bytes, destinationSwitchHeader, Headers_SwitchHeader_SIZE);
}
return context->switchInterface.receiveMessage(message, &context->switchInterface);
}
static inline int incomingFromRouter(struct Message* message,
struct Ducttape_MessageHeader* dtHeader,
struct SessionManager_Session* session,
struct Ducttape_pvt* context)
{
uint8_t* pubKey = CryptoAuth_getHerPublicKey(&session->iface);
if (!validEncryptedIP6(message)) {
// Not valid cjdns IPv6, we'll try it as an IPv4 or ICANN-IPv6 packet
// and check if we have an agreement with the node who sent it.
Message_shift(message, IpTunnel_PacketInfoHeader_SIZE);
struct IpTunnel_PacketInfoHeader* header =
(struct IpTunnel_PacketInfoHeader*) message->bytes;
uint8_t* addr = session->ip6;
Bits_memcpyConst(header->nodeIp6Addr, addr, 16);
Bits_memcpyConst(header->nodeKey, pubKey, 32);
struct Interface* ipTun = &context->ipTunnel->nodeInterface;
return ipTun->sendMessage(message, ipTun);
}
struct Address srcAddr = {
.path = Endian_bigEndianToHost64(dtHeader->switchHeader->label_be)
};
Bits_memcpyConst(srcAddr.key, pubKey, 32);
//Log_debug(context->logger, "Got message from router.\n");
int ret = core(message, dtHeader, session, context);
struct Node* n = RouterModule_getNode(srcAddr.path, context->routerModule);
if (!n) {
Address_getPrefix(&srcAddr);
RouterModule_addNode(context->routerModule, &srcAddr, session->version);
} else {
n->reach += 1;
RouterModule_updateReach(n, context->routerModule);
}
return ret;
}
static uint8_t incomingFromCryptoAuth(struct Message* message, struct Interface* iface)
{
struct Ducttape_pvt* context = Identity_cast((struct Ducttape_pvt*) iface->receiverContext);
struct Ducttape_MessageHeader* dtHeader = getDtHeader(message, false);
enum Ducttape_SessionLayer layer = dtHeader->layer;
dtHeader->layer = Ducttape_SessionLayer_INVALID;
struct SessionManager_Session* session =
SessionManager_sessionForHandle(dtHeader->receiveHandle, context->sm);
if (!session) {
// This should never happen but there's no strong preventitive.
Log_info(context->logger, "SESSION DISAPPEARED!");
return 0;
}
// If the packet came from a new session, put the send handle in the session.
if (CryptoAuth_getState(iface) < CryptoAuth_ESTABLISHED) {
// If this is true then the incoming message is definitely a handshake.
if (message->length < 4) {
debugHandles0(context->logger, session, "runt");
return Error_INVALID;
}
if (layer == Ducttape_SessionLayer_OUTER) {
#ifdef Version_2_COMPAT
if (dtHeader->currentSessionVersion >= 3) {
session->version = dtHeader->currentSessionVersion;
#endif
Message_pop(message, &session->sendHandle_be, 4);
#ifdef Version_2_COMPAT
} else {
session->sendHandle_be = dtHeader->currentSessionSendHandle_be;
}
#endif
} else {
// inner layer, always grab the handle
Message_pop(message, &session->sendHandle_be, 4);
debugHandles0(context->logger, session, "New session, incoming layer3");
}
}
switch (layer) {
case Ducttape_SessionLayer_OUTER:
return incomingFromRouter(message, dtHeader, session, context);
case Ducttape_SessionLayer_INNER:
return incomingForMe(message, dtHeader, session, context,
CryptoAuth_getHerPublicKey(iface));
default:
Assert_always(false);
}
// never reached.
return 0;
}
static uint8_t outgoingFromCryptoAuth(struct Message* message, struct Interface* iface)
{
struct Ducttape_pvt* context = Identity_cast((struct Ducttape_pvt*) iface->senderContext);
struct Ducttape_MessageHeader* dtHeader = getDtHeader(message, false);
struct SessionManager_Session* session =
SessionManager_sessionForHandle(dtHeader->receiveHandle, context->sm);
enum Ducttape_SessionLayer layer = dtHeader->layer;
dtHeader->layer = Ducttape_SessionLayer_INVALID;
if (!session) {
// This should never happen but there's no strong preventitive.
Log_info(context->logger, "SESSION DISAPPEARED!");
return 0;
}
if (layer == Ducttape_SessionLayer_OUTER) {
return sendToSwitch(message, dtHeader, session, context);
} else if (layer == Ducttape_SessionLayer_INNER) {
Log_debug(context->logger, "Sending layer3 message");
return outgoingFromMe(message, dtHeader, session, context);
} else {
Assert_true(0);
}
}
/**
* Handle an incoming control message from a switch.
*
* @param context the ducttape context.
* @param message the control message, this should be alligned on the beginning of the content,
* that is to say, after the end of the switch header.
* @param switchHeader the header.
* @param switchIf the interface which leads to the switch.
*/
static uint8_t handleControlMessage(struct Ducttape_pvt* context,
struct Message* message,
struct Headers_SwitchHeader* switchHeader,
struct Interface* switchIf)
{
uint8_t labelStr[20];
uint64_t label = Endian_bigEndianToHost64(switchHeader->label_be);
AddrTools_printPath(labelStr, label);
if (message->length < Control_HEADER_SIZE) {
Log_info(context->logger, "dropped runt ctrl packet from [%s]", labelStr);
return Error_NONE;
}
struct Control* ctrl = (struct Control*) message->bytes;
if (Checksum_engine(message->bytes, message->length)) {
Log_info(context->logger, "ctrl packet from [%s] with invalid checksum.", labelStr);
return Error_NONE;
}
bool pong = false;
if (ctrl->type_be == Control_ERROR_be) {
if (message->length < Control_Error_MIN_SIZE) {
Log_info(context->logger, "dropped runt error packet from [%s]", labelStr);
return Error_NONE;
}
uint64_t path = Endian_bigEndianToHost64(switchHeader->label_be);
RouterModule_brokenPath(path, context->routerModule);
uint8_t causeType = Headers_getMessageType(&ctrl->content.error.cause);
if (causeType == Headers_SwitchHeader_TYPE_CONTROL) {
if (message->length < Control_Error_MIN_SIZE + Control_HEADER_SIZE) {
Log_info(context->logger,
"error packet from [%s] containing runt cause packet",
labelStr);
return Error_NONE;
}
struct Control* causeCtrl = (struct Control*) &(&ctrl->content.error.cause)[1];
if (causeCtrl->type_be != Control_PING_be) {
Log_info(context->logger,
"error packet from [%s] caused by [%s] packet ([%u])",
labelStr,
Control_typeString(causeCtrl->type_be),
Endian_bigEndianToHost16(causeCtrl->type_be));
} else {
if (LabelSplicer_isOneHop(label)
&& ctrl->content.error.errorType_be
== Endian_hostToBigEndian32(Error_UNDELIVERABLE))
{
// this is our own InterfaceController complaining
// because the node isn't responding to pings.
return Error_NONE;
}
Log_debug(context->logger,
"error packet from [%s] in response to ping, err [%u], length: [%u].",
labelStr,
Endian_bigEndianToHost32(ctrl->content.error.errorType_be),
message->length);
// errors resulting from pings are forwarded back to the pinger.
pong = true;
}
} else if (causeType != Headers_SwitchHeader_TYPE_DATA) {
Log_info(context->logger,
"error packet from [%s] containing cause of unknown type [%u]",
labelStr, causeType);
} else {
Log_info(context->logger,
"error packet from [%s], error type [%u]",
labelStr,
Endian_bigEndianToHost32(ctrl->content.error.errorType_be));
}
} else if (ctrl->type_be == Control_PONG_be) {
pong = true;
} else if (ctrl->type_be == Control_PING_be) {
Message_shift(message, -Control_HEADER_SIZE);
if (message->length < Control_Ping_MIN_SIZE) {
Log_info(context->logger, "dropped runt ping");
return Error_INVALID;
}
struct Control_Ping* ping = (struct Control_Ping*) message->bytes;
ping->magic = Control_Pong_MAGIC;
ping->version_be = Endian_hostToBigEndian32(Version_CURRENT_PROTOCOL);
Message_shift(message, Control_HEADER_SIZE);
ctrl->type_be = Control_PONG_be;
ctrl->checksum_be = 0;
ctrl->checksum_be = Checksum_engine(message->bytes, message->length);
Message_shift(message, Headers_SwitchHeader_SIZE);
Log_info(context->logger, "got switch ping from [%s]", labelStr);
switchIf->receiveMessage(message, switchIf);
} else {
Log_info(context->logger,
"control packet of unknown type from [%s], type [%d]",
labelStr, Endian_bigEndianToHost16(ctrl->type_be));
}
if (pong && context->pub.switchPingerIf.receiveMessage) {
// Shift back over the header
Message_shift(message, Headers_SwitchHeader_SIZE);
context->pub.switchPingerIf.receiveMessage(
message, &context->pub.switchPingerIf);
}
return Error_NONE;
}
/**
* Messages with content encrypted and header decrypted are sent here to be forwarded.
* they may come from us, or from another node and may be to us or to any other node.
* Message is aligned on the beginning of the ipv6 header.
*/
static inline int core(struct Message* message,
struct Ducttape_MessageHeader* dtHeader,
struct SessionManager_Session* session,
struct Ducttape_pvt* context)
{
struct Headers_IP6Header* ip6Header = (struct Headers_IP6Header*) message->bytes;
dtHeader->ip6Header = ip6Header;
if (isForMe(message, context)) {
Message_shift(message, -Headers_IP6Header_SIZE);
if (Bits_memcmp(session->ip6, ip6Header->sourceAddr, 16)) {
// triple encrypted
// This call goes to incomingForMe()
struct SessionManager_Session* session =
SessionManager_getSession(ip6Header->sourceAddr, NULL, context->sm);
#ifdef Log_DEBUG
uint8_t addr[40];
AddrTools_printIp(addr, ip6Header->sourceAddr);
Log_debug(context->logger, "Incoming layer3 message, ostensibly from [%s]", addr);
#endif
dtHeader->receiveHandle = Endian_bigEndianToHost32(session->receiveHandle_be);
dtHeader->layer = Ducttape_SessionLayer_INNER;
return session->iface.receiveMessage(message, &session->iface);
} else {
// double encrypted, inner layer plaintext.
// The session is still set from the router-to-router traffic and that is the one we use
// to determine the node's id.
return incomingForMe(message, dtHeader, session, context,
CryptoAuth_getHerPublicKey(&session->iface));
}
}
if (ip6Header->hopLimit == 0) {
Log_debug(context->logger, "dropped message because hop limit has been exceeded.\n");
// TODO: send back an error message in response.
return Error_UNDELIVERABLE;
}
ip6Header->hopLimit--;
struct SessionManager_Session* nextHopSession = NULL;
if (!dtHeader->nextHopReceiveHandle || !dtHeader->switchLabel) {
struct Node* n = RouterModule_lookup(ip6Header->destinationAddr, context->routerModule);
if (n) {
nextHopSession =
SessionManager_getSession(n->address.ip6.bytes, n->address.key, context->sm);
dtHeader->switchLabel = n->address.path;
}
} else {
nextHopSession =
SessionManager_sessionForHandle(dtHeader->nextHopReceiveHandle, context->sm);
}
if (nextHopSession) {
#ifdef Log_DEBUG
struct Address addr;
Bits_memcpyConst(addr.ip6.bytes, nextHopSession->ip6, 16);
addr.path = dtHeader->switchLabel;
uint8_t nhAddr[60];
Address_print(nhAddr, &addr);
if (Bits_memcmp(ip6Header->destinationAddr, addr.ip6.bytes, 16)) {
// Potentially forwarding for ourselves.
struct Address destination;
Bits_memcpyConst(destination.ip6.bytes, ip6Header->destinationAddr, 16);
uint8_t ipAddr[40];
Address_printIp(ipAddr, &destination);
Log_debug(context->logger, "Forwarding data to %s via %s\n", ipAddr, nhAddr);
} else {
// Definitely forwarding on behalf of someone else.
Log_debug(context->logger, "Forwarding data to %s (last hop)\n", nhAddr);
}
#endif
return sendToRouter(message, dtHeader, nextHopSession, context);
}
#ifdef Log_INFO
struct Address destination;
Bits_memcpyConst(destination.ip6.bytes, ip6Header->destinationAddr, 16);
uint8_t ipAddr[40];
Address_printIp(ipAddr, &destination);
Log_info(context->logger, "Dropped message because this node is the closest known "
"node to the destination %s.", ipAddr);
#endif
return Error_UNDELIVERABLE;
}
static int handleOutgoing(struct DHTMessage* dmessage,
void* vcontext)
{
struct Ducttape_pvt* context = Identity_cast((struct Ducttape_pvt*) vcontext);
struct Message message = {
.length = dmessage->length,
.bytes = (uint8_t*) dmessage->bytes,
.padding = 512,
.capacity = DHTMessage_MAX_SIZE
};
Message_shift(&message, Headers_UDPHeader_SIZE);
struct Headers_UDPHeader* uh = (struct Headers_UDPHeader*) message.bytes;
uh->sourceAndDestPorts = 0;
uh->length_be = Endian_hostToBigEndian16(dmessage->length);
uh->checksum_be = 0;
uint16_t payloadLength = message.length;
Message_shift(&message, Headers_IP6Header_SIZE);
struct Headers_IP6Header* header = (struct Headers_IP6Header*) message.bytes;
header->versionClassAndFlowLabel = 0;
header->flowLabelLow_be = 0;
header->nextHeader = 17;
header->hopLimit = 0;
header->payloadLength_be = Endian_hostToBigEndian16(payloadLength);
Bits_memcpyConst(header->sourceAddr,
context->myAddr.ip6.bytes,
Address_SEARCH_TARGET_SIZE);
Bits_memcpyConst(header->destinationAddr,
dmessage->address->ip6.bytes,
Address_SEARCH_TARGET_SIZE);
#ifdef Log_DEBUG
Assert_true(!((uintptr_t)dmessage->bytes % 4) || !"alignment fault");
#endif
uh->checksum_be =
Checksum_udpIp6(header->sourceAddr, (uint8_t*) uh, message.length - Headers_IP6Header_SIZE);
struct Ducttape_MessageHeader* dtHeader = getDtHeader(&message, true);
dtHeader->ip6Header = header;
dtHeader->switchLabel = dmessage->address->path;
struct SessionManager_Session* session =
SessionManager_getSession(dmessage->address->ip6.bytes,
dmessage->address->key,
context->sm);
if (session->version == Version_DEFAULT_ASSUMPTION && dmessage->replyTo) {
int64_t* verPtr = Dict_getInt(dmessage->replyTo->asDict, String_CONST("p"));
session->version = (verPtr) ? *verPtr : Version_DEFAULT_ASSUMPTION;
}
if (session->version == Version_DEFAULT_ASSUMPTION) {
struct Node* n = RouterModule_getNode(dmessage->address->path, context->routerModule);
if (n) {
n->version = session->version =
(n->version > session->version) ? n->version : session->version;
}
}
sendToRouter(&message, dtHeader, session, context);
return 0;
}
// Aligned on the beginning of the content.
static inline bool isRouterTraffic(struct Message* message, struct Headers_IP6Header* ip6)
{
if (ip6->nextHeader != 17 || ip6->hopLimit != 0) {
return false;
}
struct Headers_UDPHeader* uh = (struct Headers_UDPHeader*) message->bytes;
return message->length >= Headers_UDPHeader_SIZE
&& uh->sourceAndDestPorts == 0
&& (int) Endian_bigEndianToHost16(uh->length_be) ==
(message->length - Headers_UDPHeader_SIZE);
}
#define debugHandles(logger, session, message, ...) \
do { \
uint8_t ip[40]; \
AddrTools_printIp(ip, session->ip6); \
Log_debug(logger, "ver[%u] send[%d] recv[%u] ip[%s] " message, \
session->version, \
Endian_hostToBigEndian32(session->sendHandle_be), \
Endian_hostToBigEndian32(session->receiveHandle_be), \
ip, \
__VA_ARGS__); \
} while (0)
//CHECKFILES_IGNORE expecting a ;
#define debugHandles0(logger, session, message) \
debugHandles(logger, session, message "%s", "")
#define debugHandlesAndLabel(logger, session, label, message, ...) \
do { \
uint8_t path[20]; \
AddrTools_printPath(path, label); \
debugHandles(logger, session, "path[%s] " message, path, __VA_ARGS__); \
} while (0)
//CHECKFILES_IGNORE expecting a ;
#define debugHandlesAndLabel0(logger, session, label, message) \
debugHandlesAndLabel(logger, session, label, "%s", message)
/**
* Message which is for us, message is aligned on the beginning of the content.
* this is called from core() which calls through an interfaceMap.
*/
static inline uint8_t incomingForMe(struct Message* message,
struct Ducttape_MessageHeader* dtHeader,
struct SessionManager_Session* session,
struct Ducttape_pvt* context,
uint8_t herPublicKey[32])
{
struct Address addr;
Bits_memcpyConst(addr.ip6.bytes, session->ip6, 16);
//AddressCalc_addressForPublicKey(addr.ip6.bytes, herPubKey);
if (Bits_memcmp(addr.ip6.bytes, dtHeader->ip6Header->sourceAddr, 16)) {
#ifdef Log_DEBUG
uint8_t keyAddr[40];
Address_printIp(keyAddr, &addr);
Bits_memcpyConst(addr.ip6.bytes, dtHeader->ip6Header->sourceAddr, 16);
uint8_t srcAddr[40];
Address_printIp(srcAddr, &addr);
Log_debug(context->logger,
"Dropped packet because source address is not same as key.\n"
" %s source addr\n"
" %s hash of key\n",
srcAddr,
keyAddr);
#endif
return Error_INVALID;
}
if (isRouterTraffic(message, dtHeader->ip6Header)) {
// Check the checksum.
struct Headers_UDPHeader* uh = (struct Headers_UDPHeader*) message->bytes;
if (Checksum_udpIp6(dtHeader->ip6Header->sourceAddr, (uint8_t*)uh, message->length)) {
#ifdef Log_DEBUG
uint8_t keyAddr[40];
Address_printIp(keyAddr, &addr);
Log_debug(context->logger,
"Router packet with incorrect checksum, from [%s]", keyAddr);
#endif
return Error_INVALID;
}
// Shift off the UDP header.
Message_shift(message, -Headers_UDPHeader_SIZE);
addr.path = Endian_bigEndianToHost64(dtHeader->switchHeader->label_be);
Bits_memcpyConst(addr.key, herPublicKey, 32);
return incomingDHT(message, &addr, context);
}
if (!context->userIf) {
Log_warn(context->logger,
"Dropping message because there is no router interface configured.\n");
return Error_UNDELIVERABLE;
}
// prevent router advertizement schenanigans
if (dtHeader->ip6Header->hopLimit == 255) {
dtHeader->ip6Header->hopLimit--;
}
// Now write a message to the TUN device.
// Need to move the ipv6 header forward up to the content because there's a crypto header
// between the ipv6 header and the content which just got eaten.
Message_shift(message, Headers_IP6Header_SIZE);
uint16_t sizeDiff = message->bytes - (uint8_t*)dtHeader->ip6Header;
if (sizeDiff) {
dtHeader->ip6Header->payloadLength_be =
Endian_hostToBigEndian16(
Endian_bigEndianToHost16(dtHeader->ip6Header->payloadLength_be) - sizeDiff);
Bits_memmoveConst(message->bytes, dtHeader->ip6Header, Headers_IP6Header_SIZE);
}
TUNMessageType_push(message, Ethernet_TYPE_IP6);
context->userIf->sendMessage(message, context->userIf);
return Error_NONE;
}
uint8_t Ducttape_injectIncomingForMe(struct Message* message,
struct Ducttape* dt,
uint8_t herPublicKey[32])
{
struct Ducttape_pvt* context = Identity_cast((struct Ducttape_pvt*)dt);
struct Ducttape_MessageHeader* dtHeader = getDtHeader(message, true);
struct Headers_SwitchHeader sh;
Bits_memcpyConst(&sh, message->bytes, Headers_SwitchHeader_SIZE);
dtHeader->switchHeader = &sh;
Message_shift(message, -Headers_SwitchHeader_SIZE);
struct Headers_IP6Header ip6;
Bits_memcpyConst(&ip6, message->bytes, Headers_IP6Header_SIZE);
dtHeader->ip6Header = &ip6;
Message_shift(message, -Headers_IP6Header_SIZE);
struct SessionManager_Session s;
AddressCalc_addressForPublicKey(s.ip6, herPublicKey);
s.version = Version_CURRENT_PROTOCOL;
return incomingForMe(message, dtHeader, &s, context, herPublicKey);
}
/**
* Send a message to another switch.
* Switchheader will precede the message.
*/
static inline uint8_t sendToSwitch(struct Message* message,
struct Ducttape_MessageHeader* dtHeader,
struct SessionManager_Session* session,
struct Ducttape_pvt* context)
{
uint64_t label = dtHeader->switchLabel;
if (CryptoAuth_getState(&session->iface) >= CryptoAuth_HANDSHAKE3) {
debugHandlesAndLabel0(context->logger, session, label, "layer2 sending run message");
uint32_t sendHandle_be = session->sendHandle_be;
#ifdef Version_2_COMPAT
if (session->version < 3) {
sendHandle_be |= HANDLE_FLAG_BIT_be;
}
#endif
Message_push(message, &sendHandle_be, 4);
} else {
debugHandlesAndLabel0(context->logger, session, label, "layer2 sending start message");
#ifdef Version_2_COMPAT
if (session->version < 3) {
Message_push(message, &session->receiveHandle_be, 4);
}
#endif
}
Message_shift(message, Headers_SwitchHeader_SIZE);
Assert_true(message->bytes == (uint8_t*)dtHeader->switchHeader);
return context->switchInterface.receiveMessage(message, &context->switchInterface);
}
/**
* Messages with content encrypted and header decrypted are sent here to be forwarded.
* they may come from us, or from another node and may be to us or to any other node.
* Message is aligned on the beginning of the ipv6 header.
*/
static inline int core(struct Message* message, struct Context* context)
{
context->ip6Header = (struct Headers_IP6Header*) message->bytes;
if (!validIP6(message)) {
Log_debug(context->logger, "Dropping message because of invalid ipv6 header.\n");
return Error_INVALID;
}
// Do this here and check for 1 hop, not 0 because we want to differentiate between single
// hop traffic and routed traffic as single hop traffic doesn't need 2 layers of crypto.
if (context->ip6Header->hopLimit == 1) {
Log_debug(context->logger, "dropped message because hop limit has been exceeded.\n");
// TODO: send back an error message in response.
return Error_UNDELIVERABLE;
}
if (isForMe(message, context)) {
Message_shift(message, -Headers_IP6Header_SIZE);
if (context->ip6Header->hopLimit != 0) {
// triple encrypted
// This call goes to incomingForMe()
context->layer = INNER_LAYER;
context->session =
SessionManager_getSession(context->ip6Header->sourceAddr, NULL, context->sm);
return context->session->receiveMessage(message, context->session);
} else {
// double encrypted, inner layer plaintext.
// The session is still set from the router-to-router traffic and that is the one we use
// to determine the node's id.
return incomingForMe(message, context);
}
}
if (context->ip6Header->hopLimit == 0) {
Log_debug(context->logger, "0 hop message not addressed to us, broken route.\n");
return 0;
}
context->ip6Header->hopLimit--;
struct Address* ft = context->forwardTo;
context->forwardTo = NULL;
if (!ft) {
struct Node* bestNext =
RouterModule_getBest(context->ip6Header->destinationAddr, context->routerModule);
if (bestNext) {
ft = &bestNext->address;
}
}
if (ft) {
#ifdef Log_DEBUG
uint8_t nhAddr[60];
Address_print(nhAddr, ft);
if (memcmp(context->ip6Header->destinationAddr, ft->ip6.bytes, 16)) {
// Potentially forwarding for ourselves.
struct Address destination;
memcpy(destination.ip6.bytes, context->ip6Header->destinationAddr, 16);
uint8_t ipAddr[40];
Address_printIp(ipAddr, &destination);
Log_debug2(context->logger, "Forwarding data to %s via %s\n", ipAddr, nhAddr);
} else {
// Definitely forwarding on behalf of someone else.
Log_debug1(context->logger, "Forwarding data to %s (last hop)\n", nhAddr);
}
#endif
return sendToRouter(ft, message, context);
}
Log_debug(context->logger, "Dropped message because this node is the closest known "
"node to the destination.\n");
return Error_UNDELIVERABLE;
}
