Take like ten on the addRoot thing, making it even simpler. Explicit locator commands are still present but they will remain just for use in creating subscriptions etc.

go/pkg/zerotier/node.go

@@ -484,6 +484,39 @@ func (n *Node) Peers() []*Peer {
 	return peers
 }
 
+// AddPeer adds a peer by explicit identity.
+func (n *Node) AddPeer(id *Identity) error {
+	if id == nil {
+		return ErrInvalidParameter
+	}
+	if !id.initCIdentityPtr() {
+		return ErrInvalidKey
+	}
+	rc := C.ZT_Node_addPeer(n.zn, nil, id.cid)
+	if rc != 0 {
+		return ErrInvalidParameter
+	}
+	return nil
+}
+
+// TryPeer attempts to contact a peer at a given explicit endpoint.
+// The peer may be identified by an Address or a full Fingerprint. Any other
+// type for fpOrAddress will return false.
+func (n *Node) TryPeer(fpOrAddress interface{}, ep *Endpoint, retries int) bool {
+	if ep == nil {
+		return false
+	}
+	fp, _ := fpOrAddress.(*Fingerprint)
+	if fp == nil {
+		a, _ := fpOrAddress.(*Address)
+		if a == nil {
+			return false
+		}
+		fp = &Fingerprint{Address: *a}
+	}
+	return C.ZT_Node_tryPeer(n.zn, nil, fp.cFingerprint(), &ep.cep, C.int(retries)) != 0
+}
+
 // --------------------------------------------------------------------------------------------------------------------
 
 func (n *Node) runMaintenance() {

include/ZeroTierCore.h

@@ -470,7 +470,7 @@ enum ZT_ResultCode
 	ZT_RESULT_FATAL_ERROR_DATA_STORE_FAILED = 101,
 
 	/**
-	 * Internal error (e.g. unexpected exception indicating bug or build problem)
+	 * Internal error fatal to the instance
 	 */
 	ZT_RESULT_FATAL_ERROR_INTERNAL = 102,
 
@@ -494,7 +494,17 @@ enum ZT_ResultCode
 	/**
 	 * A credential or other object was supplied that failed cryptographic signature or integrity check
 	 */
-	ZT_RESULT_ERROR_INVALID_CREDENTIAL = 1003
+	ZT_RESULT_ERROR_INVALID_CREDENTIAL = 1003,
+
+	/**
+	 * An object collides with another object in some way (meaning is object-specific)
+	 */
+	ZT_RESULT_ERROR_COLLIDING_OBJECT = 1004,
+
+	/**
+	 * An internal error occurred, but one that is not fatal to the whole instance
+	 */
+	ZT_RESULT_ERROR_INTERNAL = 1005
 };
 
 /**
@@ -1844,6 +1854,9 @@ ZT_SDK_API enum ZT_ResultCode ZT_Node_addRoot(
  * This doesn't fully remove the peer from the peer list. It just removes
  * its root trust flag. If there is no longer any need to communicate with it
  * it may gradually time out and be removed.
+ * 
+ * The removeRoot() only takes an address since the identity is by definition
+ * already known and pinned.
  *
  * @param node Node instance
  * @param tptr Thread pointer to pass to functions/callbacks resulting from this call
@@ -1943,6 +1956,49 @@ ZT_SDK_API void ZT_Node_setInterfaceAddresses(
 	const ZT_InterfaceAddress *addrs,
 	unsigned int addrCount);
 
+/**
+ * Add a peer directly by supplying its identity
+ * 
+ * This does not authorize the peer on a network (only the network's
+ * controller can do that) or otherwise give it special privileges. It
+ * also doesn't guarantee it will be contacted. It just adds it to the
+ * internal peer data set if it is not already present.
+ * 
+ * @param node Node instance
+ * @param tptr Thread pointer to pass to functions/callbacks resulting from this call
+ * @param id Identity of peer to add
+ * @return OK (0) or error code
+ */
+ZT_SDK_API enum ZT_ResultCode ZT_Node_addPeer(
+	ZT_Node *node,
+	void *tptr,
+	const ZT_Identity *id);
+
+/**
+ * Attempt to contact a peer at an explicit endpoint address.
+ * 
+ * If the fingerprint structure's hash is all zeroes, the peer is
+ * looked up only by address.
+ * 
+ * This can only fail if the peer was not found.
+ * 
+ * Note that this can immediately (before this returns) result in
+ * calls to the send packet functions supplied to the core.
+ * 
+ * @param node Node instance
+ * @param tptr Thread pointer to pass to functions/callbacks resulting from this call
+ * @param fp Fingerprint (or only address)
+ * @param endpoint Endpoint
+ * @param retries If greater than zero, try this many times
+ * @return Boolean: non-zero on success, zero if peer was not found
+ */
+ZT_SDK_API int ZT_Node_tryPeer(
+	ZT_Node *node,
+	void *tptr,
+	const ZT_Fingerprint *fp,
+	const ZT_Endpoint *endpoint,
+	int retries);
+
 /**
  * Send a VERB_USER_MESSAGE to another ZeroTier node
  *

node/Fingerprint.hpp

@@ -87,6 +87,24 @@ public:
 		return true;
 	}
 
+	/**
+	 * Check for equality with best possible specificity.
+	 * 
+	 * If both fingerprints have a hash, that is compared. Otherwise just the
+	 * addresses are compared.
+	 * 
+	 * @param fp Fingerprint to test
+	 */
+	ZT_INLINE bool bestSpecificityEquals(const ZT_Fingerprint &fp) const noexcept
+	{
+		if (address == fp.address) {
+			if (Utils::allZero(fp.hash, ZT_FINGERPRINT_HASH_SIZE) || Utils::allZero(hash, ZT_FINGERPRINT_HASH_SIZE))
+				return true;
+			return (memcmp(hash, fp.hash, ZT_FINGERPRINT_HASH_SIZE) == 0);
+		}
+		return false;
+	}
+
 	ZT_INLINE void zero() noexcept
 	{ memoryZero(this); }
 
@@ -115,22 +133,22 @@ public:
 		return ZT_FINGERPRINT_MARSHAL_SIZE;
 	}
 
-	ZT_INLINE bool operator==(const Fingerprint &h) const noexcept
+	ZT_INLINE bool operator==(const ZT_Fingerprint &h) const noexcept
 	{ return ((this->address == h.address) && (memcmp(this->hash, h.hash, ZT_FINGERPRINT_HASH_SIZE) == 0)); }
 
-	ZT_INLINE bool operator!=(const Fingerprint &h) const noexcept
+	ZT_INLINE bool operator!=(const ZT_Fingerprint &h) const noexcept
 	{ return !(*this == h); }
 
-	ZT_INLINE bool operator<(const Fingerprint &h) const noexcept
+	ZT_INLINE bool operator<(const ZT_Fingerprint &h) const noexcept
 	{ return ((this->address < h.address) || ((this->address == h.address) && (memcmp(this->hash, h.hash, ZT_FINGERPRINT_HASH_SIZE) < 0))); }
 
-	ZT_INLINE bool operator>(const Fingerprint &h) const noexcept
-	{ return (h < *this); }
+	ZT_INLINE bool operator>(const ZT_Fingerprint &h) const noexcept
+	{ return (*reinterpret_cast<const Fingerprint *>(&h) < *this); }
 
-	ZT_INLINE bool operator<=(const Fingerprint &h) const noexcept
-	{ return !(h < *this); }
+	ZT_INLINE bool operator<=(const ZT_Fingerprint &h) const noexcept
+	{ return !(*reinterpret_cast<const Fingerprint *>(&h) < *this); }
 
-	ZT_INLINE bool operator>=(const Fingerprint &h) const noexcept
+	ZT_INLINE bool operator>=(const ZT_Fingerprint &h) const noexcept
 	{ return !(*this < h); }
 };
 

node/Node.cpp

@@ -66,7 +66,11 @@ struct _sortPeerPtrsByAddress
 
 } // anonymous namespace
 
-Node::Node(void *uPtr, void *tPtr, const struct ZT_Node_Callbacks *callbacks, int64_t now) :
+Node::Node(
+	void *uPtr,
+	void *tPtr,
+	const struct ZT_Node_Callbacks *callbacks,
+	int64_t now) :
 	m_RR(this),
 	RR(&m_RR),
 	m_objects(nullptr),
@@ -210,7 +214,10 @@ ZT_ResultCode Node::processVirtualNetworkFrame(
 	}
 }
 
-ZT_ResultCode Node::processBackgroundTasks(void *tPtr, int64_t now, volatile int64_t *nextBackgroundTaskDeadline)
+ZT_ResultCode Node::processBackgroundTasks(
+	void *tPtr,
+	int64_t now,
+	volatile int64_t *nextBackgroundTaskDeadline)
 {
 	m_now = now;
 	Mutex::Lock bl(m_backgroundTasksLock);
@@ -278,7 +285,11 @@ ZT_ResultCode Node::processBackgroundTasks(void *tPtr, int64_t now, volatile int
 	return ZT_RESULT_OK;
 }
 
-ZT_ResultCode Node::join(uint64_t nwid, const ZT_Fingerprint *controllerFingerprint, void *uptr, void *tptr)
+ZT_ResultCode Node::join(
+	uint64_t nwid,
+	const ZT_Fingerprint *controllerFingerprint,
+	void *uptr,
+	void *tptr)
 {
 	Fingerprint fp;
 	if (controllerFingerprint) {
@@ -297,7 +308,10 @@ ZT_ResultCode Node::join(uint64_t nwid, const ZT_Fingerprint *controllerFingerpr
 	return ZT_RESULT_OK;
 }
 
-ZT_ResultCode Node::leave(uint64_t nwid, void **uptr, void *tptr)
+ZT_ResultCode Node::leave(
+	uint64_t nwid,
+	void **uptr,
+	void *tptr)
 {
 	ZT_SPEW("leaving network %.16llx",nwid);
 	ZT_VirtualNetworkConfig ctmp;
@@ -329,7 +343,11 @@ ZT_ResultCode Node::leave(uint64_t nwid, void **uptr, void *tptr)
 	return ZT_RESULT_OK;
 }
 
-ZT_ResultCode Node::multicastSubscribe(void *tPtr, uint64_t nwid, uint64_t multicastGroup, unsigned long multicastAdi)
+ZT_ResultCode Node::multicastSubscribe(
+	void *tPtr,
+	uint64_t nwid,
+	uint64_t multicastGroup,
+	unsigned long multicastAdi)
 {
 	ZT_SPEW("multicast subscribe to %s:%lu",MAC(multicastGroup).toString().c_str(),multicastAdi);
 	const SharedPtr<Network> nw(this->network(nwid));
@@ -339,7 +357,10 @@ ZT_ResultCode Node::multicastSubscribe(void *tPtr, uint64_t nwid, uint64_t multi
 	} else return ZT_RESULT_ERROR_NETWORK_NOT_FOUND;
 }
 
-ZT_ResultCode Node::multicastUnsubscribe(uint64_t nwid, uint64_t multicastGroup, unsigned long multicastAdi)
+ZT_ResultCode Node::multicastUnsubscribe(
+	uint64_t nwid,
+	uint64_t multicastGroup,
+	unsigned long multicastAdi)
 {
 	ZT_SPEW("multicast unsubscribe from %s:%lu",MAC(multicastGroup).toString().c_str(),multicastAdi);
 	const SharedPtr<Network> nw(this->network(nwid));
@@ -349,12 +370,16 @@ ZT_ResultCode Node::multicastUnsubscribe(uint64_t nwid, uint64_t multicastGroup,
 	} else return ZT_RESULT_ERROR_NETWORK_NOT_FOUND;
 }
 
-ZT_ResultCode Node::addRoot(void *tPtr, const ZT_Identity *id)
+ZT_ResultCode Node::addRoot(
+	void *tPtr,
+	const ZT_Identity *id)
 {
 	return (RR->topology->addRoot(tPtr, *reinterpret_cast<const Identity *>(id))) ? ZT_RESULT_OK : ZT_RESULT_ERROR_BAD_PARAMETER;
 }
 
-ZT_ResultCode Node::removeRoot(void *tPtr, const uint64_t address)
+ZT_ResultCode Node::removeRoot(
+	void *tPtr,
+	const uint64_t address)
 {
 	RR->topology->removeRoot(tPtr, Address(address));
 	return ZT_RESULT_OK;
@@ -484,14 +509,18 @@ ZT_VirtualNetworkList *Node::networks() const
 	return nl;
 }
 
-void Node::setNetworkUserPtr(uint64_t nwid, void *ptr)
+void Node::setNetworkUserPtr(
+	uint64_t nwid,
+	void *ptr)
 {
 	SharedPtr<Network> nw(network(nwid));
 	if (nw)
 		*(nw->userPtr()) = ptr;
 }
 
-void Node::setInterfaceAddresses(const ZT_InterfaceAddress *addrs, unsigned int addrCount)
+void Node::setInterfaceAddresses(
+	const ZT_InterfaceAddress *addrs,
+	unsigned int addrCount)
 {
 	Mutex::Lock _l(m_localInterfaceAddresses_m);
 	m_localInterfaceAddresses.clear();
@@ -508,7 +537,43 @@ void Node::setInterfaceAddresses(const ZT_InterfaceAddress *addrs, unsigned int
 	}
 }
 
-int Node::sendUserMessage(void *tptr, uint64_t dest, uint64_t typeId, const void *data, unsigned int len)
+ZT_ResultCode Node::addPeer(
+	void *tptr,
+	const ZT_Identity *identity)
+{
+	if (!identity)
+		return ZT_RESULT_ERROR_BAD_PARAMETER;
+	SharedPtr<Peer> peer(RR->topology->peer(tptr, reinterpret_cast<const Identity *>(identity)->address()));
+	if (!peer) {
+		peer.set(new Peer(RR));
+		peer->init(*reinterpret_cast<const Identity *>(identity));
+		peer = RR->topology->add(tptr, peer);
+	}
+	return (peer->identity() == *reinterpret_cast<const Identity *>(identity)) ? ZT_RESULT_OK : ZT_RESULT_ERROR_COLLIDING_OBJECT;
+}
+
+int Node::tryPeer(
+	void *tptr,
+	const ZT_Fingerprint *fp,
+	const ZT_Endpoint *endpoint,
+	int retries)
+{
+	if ((!fp) || (!endpoint))
+		return 0;
+	const SharedPtr<Peer> peer(RR->topology->peer(tptr,fp->address,true));
+	if ((peer) && (peer->identity().fingerprint().bestSpecificityEquals(*fp))) {
+		peer->contact(tptr, m_now, Endpoint(*endpoint), std::min(retries,1));
+		return 1;
+	}
+	return 0;
+}
+
+int Node::sendUserMessage(
+	void *tptr,
+	uint64_t dest,
+	uint64_t typeId,
+	const void *data,
+	unsigned int len)
 {
 	try {
 		if (RR->identity.address().toInt() != dest) {
@@ -775,7 +840,7 @@ enum ZT_ResultCode ZT_Node_new(ZT_Node **node, void *uptr, void *tptr, const str
 	} catch (std::runtime_error &exc) {
 		return ZT_RESULT_FATAL_ERROR_DATA_STORE_FAILED;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -804,7 +869,9 @@ enum ZT_ResultCode ZT_Node_processWirePacket(
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_OK; // "OK" since invalid packets are simply dropped, but the system is still up
+		// "OK" since invalid packets are simply dropped, but the system is still up.
+		// We should never make it here, but if we did that would be the interpretation.
+		return ZT_RESULT_OK;
 	}
 }
 
@@ -828,7 +895,7 @@ enum ZT_ResultCode ZT_Node_processVirtualNetworkFrame(
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -839,7 +906,7 @@ enum ZT_ResultCode ZT_Node_processBackgroundTasks(ZT_Node *node, void *tptr, int
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -850,7 +917,7 @@ enum ZT_ResultCode ZT_Node_join(ZT_Node *node, uint64_t nwid, const ZT_Fingerpri
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -861,7 +928,7 @@ enum ZT_ResultCode ZT_Node_leave(ZT_Node *node, uint64_t nwid, void **uptr, void
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -872,7 +939,7 @@ enum ZT_ResultCode ZT_Node_multicastSubscribe(ZT_Node *node, void *tptr, uint64_
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -883,7 +950,7 @@ enum ZT_ResultCode ZT_Node_multicastUnsubscribe(ZT_Node *node, uint64_t nwid, ui
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -894,7 +961,7 @@ enum ZT_ResultCode ZT_Node_addRoot(ZT_Node *node, void *tptr, const ZT_Identity
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -905,7 +972,7 @@ enum ZT_ResultCode ZT_Node_removeRoot(ZT_Node *node, void *tptr, const uint64_t
 	} catch (std::bad_alloc &exc) {
 		return ZT_RESULT_FATAL_ERROR_OUT_OF_MEMORY;
 	} catch (...) {
-		return ZT_RESULT_FATAL_ERROR_INTERNAL;
+		return ZT_RESULT_ERROR_INTERNAL;
 	}
 }
 
@@ -953,6 +1020,20 @@ ZT_VirtualNetworkList *ZT_Node_networks(ZT_Node *node)
 	}
 }
 
+int ZT_Node_tryPeer(
+	ZT_Node *node,
+	void *tptr,
+	const ZT_Fingerprint *fp,
+	const ZT_Endpoint *endpoint,
+	int retries)
+{
+	try {
+		return reinterpret_cast<ZeroTier::Node *>(node)->tryPeer(tptr,fp,endpoint,retries);
+	} catch (...) {
+		return 0;
+	}
+}
+
 void ZT_Node_setNetworkUserPtr(ZT_Node *node, uint64_t nwid, void *ptr)
 {
 	try {
@@ -967,6 +1048,18 @@ void ZT_Node_setInterfaceAddresses(ZT_Node *node, const ZT_InterfaceAddress *add
 	} catch (...) {}
 }
 
+enum ZT_ResultCode ZT_Node_addPeer(
+	ZT_Node *node,
+	void *tptr,
+	const ZT_Identity *id)
+{
+	try {
+		return reinterpret_cast<ZeroTier::Node *>(node)->addPeer(tptr, id);
+	} catch (...) {
+		return ZT_RESULT_ERROR_INTERNAL;
+	}
+}
+
 int ZT_Node_sendUserMessage(ZT_Node *node, void *tptr, uint64_t dest, uint64_t typeId, const void *data, unsigned int len)
 {
 	try {

node/Node.hpp

@@ -126,6 +126,16 @@ public:
 		const ZT_InterfaceAddress *addrs,
 		unsigned int addrCount);
 
+	ZT_ResultCode addPeer(
+		void *tptr,
+		const ZT_Identity *identity);
+
+	int tryPeer(
+		void *tptr,
+		const ZT_Fingerprint *fp,
+		const ZT_Endpoint *endpoint,
+		int retries);
+
 	int sendUserMessage(
 		void *tptr,
 		uint64_t dest,