5 meshlink++.h -- MeshLink C++ API
6 Copyright (C) 2014, 2017 Guus Sliepen <guus@meshlink.io>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 #include <new> // for 'placement new'
32 /// Severity of log messages generated by MeshLink.
33 typedef meshlink_log_level_t log_level_t;
35 /// Code of most recent error encountered.
36 typedef meshlink_errno_t errno_t;
38 /// A callback for receiving data from the mesh.
39 /** @param mesh A handle which represents an instance of MeshLink.
40 * @param source A pointer to a meshlink::node describing the source of the data.
41 * @param data A pointer to a buffer containing the data sent by the source.
42 * @param len The length of the received data.
44 typedef void (*receive_cb_t)(mesh *mesh, node *source, const void *data, size_t len);
46 /// A callback reporting the meta-connection attempt made by the host node to an another node.
47 /** @param mesh A handle which represents an instance of MeshLink.
48 * @param node A pointer to a meshlink_node_t describing the node to whom meta-connection is being tried.
49 * This pointer is valid until meshlink_close() is called.
51 typedef void (*connection_try_cb_t)(mesh *mesh, node *node);
53 /// A callback reporting node status changes.
54 /** @param mesh A handle which represents an instance of MeshLink.
55 * @param node A pointer to a meshlink::node describing the node whose status changed.
56 * @param reachable True if the node is reachable, false otherwise.
58 typedef void (*node_status_cb_t)(mesh *mesh, node *node, bool reachable);
60 /// A callback reporting node path MTU changes.
61 /** @param mesh A handle which represents an instance of MeshLink.
62 * @param node A pointer to a meshlink_node_t describing the node whose status changed.
63 * This pointer is valid until meshlink_close() is called.
64 * @param pmtu The current path MTU to the node, or 0 if UDP communication is not (yet) possible.
66 typedef void (*node_pmtu_cb_t)(mesh *mesh, node *node, uint16_t pmtu);
68 /// A callback reporting duplicate node detection.
69 /** @param mesh A handle which represents an instance of MeshLink.
70 * @param node A pointer to a meshlink_node_t describing the node which is duplicate.
71 * This pointer is valid until meshlink_close() is called.
73 typedef void (*duplicate_cb_t)(mesh *mesh, node *node);
75 /// A callback for receiving log messages generated by MeshLink.
76 /** @param mesh A handle which represents an instance of MeshLink.
77 * @param level An enum describing the severity level of the message.
78 * @param text A pointer to a string containing the textual log message.
80 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
82 /// A callback for listening for incoming channels.
83 /** @param mesh A handle which represents an instance of MeshLink.
84 * @param node A handle for the node that wants to open a channel.
85 * @param port The port number the peer wishes to connect to.
87 * @return This function should return true if the application listens for the incoming channel, false otherwise.
89 typedef bool (*meshlink_channel_listen_cb_t)(struct meshlink_handle *mesh, struct meshlink_node *node, uint16_t port);
91 /// A callback for accepting incoming channels.
92 /** @param mesh A handle which represents an instance of MeshLink.
93 * @param channel A handle for the incoming channel.
94 * @param port The port number the peer wishes to connect to.
95 * @param data A pointer to a buffer containing data already received. (Not yet used.)
96 * @param len The length of the data. (Not yet used.)
98 * @return This function should return true if the application accepts the incoming channel, false otherwise.
99 * If returning false, the channel is invalid and may not be used anymore.
101 typedef bool (*channel_accept_cb_t)(mesh *mesh, channel *channel, uint16_t port, const void *data, size_t len);
103 /// A callback for receiving data from a channel.
104 /** @param mesh A handle which represents an instance of MeshLink.
105 * @param channel A handle for the channel.
106 * @param data A pointer to a buffer containing data sent by the source.
107 * @param len The length of the data.
109 typedef void (*channel_receive_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len);
111 /// A callback that is called when data can be send on a channel.
112 /** @param mesh A handle which represents an instance of MeshLink.
113 * @param channel A handle for the channel.
114 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
116 typedef void (*channel_poll_cb_t)(mesh *mesh, channel *channel, size_t len);
118 /// A callback for cleaning up buffers submitted for asynchronous I/O.
119 /** This callbacks signals that MeshLink has finished using this buffer.
120 * The ownership of the buffer is now back into the application's hands.
122 * @param mesh A handle which represents an instance of MeshLink.
123 * @param channel A handle for the channel which used this buffer.
124 * @param data A pointer to a buffer containing the enqueued data.
125 * @param len The length of the buffer.
126 * @param priv A private pointer which was set by the application when submitting the buffer.
128 typedef void (*aio_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len, void *priv);
130 /// A callback for asynchronous I/O to and from filedescriptors.
131 /** This callbacks signals that MeshLink has finished using this filedescriptor.
133 * @param mesh A handle which represents an instance of MeshLink.
134 * @param channel A handle for the channel which used this filedescriptor.
135 * @param fd The filedescriptor that was used.
136 * @param len The length of the data that was successfully sent or received.
137 * @param priv A private pointer which was set by the application when submitting the buffer.
139 typedef void (*aio_fd_cb_t)(mesh *mesh, channel *channel, int fd, size_t len, void *priv);
141 /// A class describing a MeshLink node.
142 class node: public meshlink_node_t {
145 /// A class describing a MeshLink Sub-Mesh.
146 class submesh: public meshlink_submesh_t {
149 /// A class describing a MeshLink channel.
150 class channel: public meshlink_channel_t {
152 static const uint32_t RELIABLE = MESHLINK_CHANNEL_RELIABLE;
153 static const uint32_t ORDERED = MESHLINK_CHANNEL_ORDERED;
154 static const uint32_t FRAMED = MESHLINK_CHANNEL_FRAMED;
155 static const uint32_t DROP_LATE = MESHLINK_CHANNEL_DROP_LATE;
156 static const uint32_t NO_PARTIAL = MESHLINK_CHANNEL_NO_PARTIAL;
157 static const uint32_t TCP = MESHLINK_CHANNEL_TCP;
158 static const uint32_t UDP = MESHLINK_CHANNEL_UDP;
161 /// A class describing a MeshLink mesh.
164 mesh() : handle(0) {}
170 bool isOpen() const {
171 return (handle != 0);
174 // TODO: please enable C++11 in autoconf to enable "move constructors":
175 // mesh(mesh&& other)
176 // : handle(other.handle)
179 // handle->priv = this;
183 /// Initialize MeshLink's configuration directory.
184 /** This function causes MeshLink to initialize its configuration directory,
185 * if it hasn't already been initialized.
186 * It only has to be run the first time the application starts,
187 * but it is not a problem if it is run more than once, as long as
188 * the arguments given are the same.
190 * This function does not start any network I/O yet. The application should
191 * first set callbacks, and then call meshlink_start().
193 * @param confbase The directory in which MeshLink will store its configuration files.
194 * @param name The name which this instance of the application will use in the mesh.
195 * @param appname The application name which will be used in the mesh.
196 * @param devclass The device class which will be used in the mesh.
198 * @return This function will return a pointer to a meshlink::mesh if MeshLink has successfully set up its configuration files, NULL otherwise.
200 bool open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
201 handle = meshlink_open(confbase, name, appname, devclass);
210 mesh(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
211 open(confbase, name, appname, devclass);
214 /// Close the MeshLink handle.
215 /** This function calls meshlink_stop() if necessary,
216 * and frees all memory allocated by MeshLink.
217 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
222 meshlink_close(handle);
228 /** instead of registerin callbacks you derive your own class and overwrite the following abstract member functions.
229 * These functions are run in MeshLink's own thread.
230 * It is therefore important that these functions use apprioriate methods (queues, pipes, locking, etc.)
231 * to hand the data over to the application's thread.
232 * These functions should also not block itself and return as quickly as possible.
233 * The default member functions are no-ops, so you are not required to overwrite all these member functions
236 /// This function is called whenever another node sends data to the local node.
237 virtual void receive(node *source, const void *data, size_t length) {
244 /// This functions is called whenever another node's status changed.
245 virtual void node_status(node *peer, bool reachable) {
251 /// This functions is called whenever another node's path MTU changes.
252 virtual void node_pmtu(node *peer, uint16_t pmtu) {
258 /// This functions is called whenever a duplicate node is detected.
259 virtual void node_duplicate(node *peer) {
264 /// This functions is called whenever MeshLink has some information to log.
265 virtual void log(log_level_t level, const char *message) {
271 /// This functions is called whenever MeshLink has encountered a serious error.
272 virtual void error(meshlink_errno_t meshlink_errno) {
274 (void)meshlink_errno;
277 /// This functions is called whenever MeshLink is blacklisted by another node.
278 virtual void blacklisted(node *peer) {
283 /// This functions is called whenever MeshLink a meta-connection attempt is made.
284 virtual void connection_try(node *peer) {
289 /// This functions is called to determine if we are listening for incoming channels.
291 * The function is run in MeshLink's own thread.
292 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
293 * to pass data to or from the application's thread.
294 * The callback should also not block itself and return as quickly as possible.
296 * @param node A handle for the node that wants to open a channel.
297 * @param port The port number the peer wishes to connect to.
299 * @return This function should return true if the application accepts the incoming channel, false otherwise.
301 virtual bool channel_listen(node *node, uint16_t port) {
302 /* by default accept all channels */
308 /// This functions is called whenever another node attempts to open a channel to the local node.
310 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
311 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
314 * The function is run in MeshLink's own thread.
315 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
316 * to pass data to or from the application's thread.
317 * The callback should also not block itself and return as quickly as possible.
319 * @param channel A handle for the incoming channel.
320 * @param port The port number the peer wishes to connect to.
321 * @param data A pointer to a buffer containing data already received. (Not yet used.)
322 * @param len The length of the data. (Not yet used.)
324 * @return This function should return true if the application accepts the incoming channel, false otherwise.
325 * If returning false, the channel is invalid and may not be used anymore.
327 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
328 /* by default reject all channels */
336 /// This function is called by Meshlink for receiving data from a channel.
338 * The function is run in MeshLink's own thread.
339 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
340 * to pass data to or from the application's thread.
341 * The callback should also not block itself and return as quickly as possible.
343 * @param channel A handle for the channel.
344 * @param data A pointer to a buffer containing data sent by the source.
345 * @param len The length of the data.
347 virtual void channel_receive(channel *channel, const void *data, size_t len) {
354 /// This function is called by Meshlink when data can be send on a channel.
356 * The function is run in MeshLink's own thread.
357 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
358 * to pass data to or from the application's thread.
360 * The callback should also not block itself and return as quickly as possible.
361 * @param channel A handle for the channel.
362 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
364 virtual void channel_poll(channel *channel, size_t len) {
371 /** This function causes MeshLink to open network sockets, make outgoing connections, and
372 * create a new thread, which will handle all network I/O.
374 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
377 meshlink_set_receive_cb(handle, &receive_trampoline);
378 meshlink_set_node_status_cb(handle, &node_status_trampoline);
379 meshlink_set_node_pmtu_cb(handle, &node_pmtu_trampoline);
380 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
381 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
382 meshlink_set_error_cb(handle, &error_trampoline);
383 meshlink_set_blacklisted_cb(handle, &blacklisted_trampoline);
384 meshlink_set_channel_listen_cb(handle, &channel_listen_trampoline);
385 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
386 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
387 return meshlink_start(handle);
391 /** This function causes MeshLink to disconnect from all other nodes,
392 * close all sockets, and shut down its own thread.
395 meshlink_stop(handle);
398 /// Send data to another node.
399 /** This functions sends one packet of data to another node in the mesh.
400 * The packet is sent using UDP semantics, which means that
401 * the packet is sent as one unit and is received as one unit,
402 * and that there is no guarantee that the packet will arrive at the destination.
403 * The application should take care of getting an acknowledgement and retransmission if necessary.
405 * @param destination A pointer to a meshlink::node describing the destination for the data.
406 * @param data A pointer to a buffer containing the data to be sent to the source.
407 * @param len The length of the data.
408 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
409 * A return value of true does not guarantee that the message will actually arrive at the destination.
411 bool send(node *destination, const void *data, unsigned int len) {
412 return meshlink_send(handle, destination, data, len);
415 /// Get a handle for a specific node.
416 /** This function returns a handle for the node with the given name.
418 * @param name The name of the node for which a handle is requested.
420 * @return A pointer to a meshlink::node which represents the requested node,
421 * or NULL if the requested node does not exist.
423 node *get_node(const char *name) {
424 return (node *)meshlink_get_node(handle, name);
427 /// Get a node's reachability status.
428 /** This function returns the current reachability of a given node, and the times of the last state changes.
429 * If a given state change never happened, the time returned will be 0.
431 * @param node A pointer to a meshlink::node describing the node.
432 * @param last_reachable A pointer to a time_t variable that will be filled in with the last time the node became reachable.
433 * @param last_unreachable A pointer to a time_t variable that will be filled in with the last time the node became unreachable.
435 * @return This function returns true if the node is currently reachable, false otherwise.
437 bool get_node_reachability(node *node, time_t *last_reachable = NULL, time_t *last_unreachable = NULL) {
438 return meshlink_get_node_reachability(handle, node, last_reachable, last_unreachable);
441 /// Get a node's blacklist status.
442 /** This function returns the current blacklist status of a given node.
444 * @param node A pointer to a meshlink::node describing the node.
446 * @return This function returns true if the node is currently blacklisted, false otherwise.
448 bool get_node_blacklisted(node *node) {
449 return meshlink_get_node_blacklisted(handle, node);
452 /// Get a handle for a specific submesh.
453 /** This function returns a handle for the submesh with the given name.
455 * @param name The name of the submesh for which a handle is requested.
457 * @return A pointer to a meshlink::submesh which represents the requested submesh,
458 * or NULL if the requested submesh does not exist.
460 submesh *get_submesh(const char *name) {
461 return (submesh *)meshlink_get_submesh(handle, name);
464 /// Get a handle for our own node.
465 /** This function returns a handle for the local node.
467 * @return A pointer to a meshlink::node which represents the local node.
470 return (node *)meshlink_get_self(handle);
473 /// Get a list of all nodes.
474 /** This function returns a list with handles for all known nodes.
476 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
477 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
479 * @return The number of known nodes, or -1 in case of an error.
480 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
482 node **get_all_nodes(node **nodes, size_t *nmemb) {
483 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
486 /// Get a list of all nodes by blacklist status.
487 /** This function returns a list with handles for all the nodes who were either blacklisted or whitelisted.
489 * @param blacklisted If true, a list of blacklisted nodes will be returned, otherwise whitelisted nodes.
490 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
491 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
493 * @return A pointer to an array containing pointers to all known nodes with the given blacklist status.
494 * If the @a nodes argument was not NULL, then the return value can either be the same value or a different value.
495 * If it is a new value, the old value of @a nodes should not be used anymore.
496 * If the new value is NULL, then the old array will have been freed by MeshLink.
498 node **get_all_nodes_by_blacklisted(bool blacklisted, node **nodes, size_t *nmemb) {
499 return (node **)meshlink_get_all_nodes_by_blacklisted(handle, blacklisted, (meshlink_node_t **)nodes, nmemb);
502 /// Sign data using the local node's MeshLink key.
503 /** This function signs data using the local node's MeshLink key.
504 * The generated signature can be securely verified by other nodes.
506 * @param data A pointer to a buffer containing the data to be signed.
507 * @param len The length of the data to be signed.
508 * @param signature A pointer to a buffer where the signature will be stored.
509 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
511 * @return This function returns true if the signature is valid, false otherwise.
513 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
514 return meshlink_sign(handle, data, len, signature, siglen);
517 /// Verify the signature generated by another node of a piece of data.
518 /** This function verifies the signature that another node generated for a piece of data.
520 * @param source A pointer to a meshlink_node_t describing the source of the signature.
521 * @param data A pointer to a buffer containing the data to be verified.
522 * @param len The length of the data to be verified.
523 * @param signature A pointer to a string containing the signature.
524 * @param siglen The size of the signature.
526 * @return This function returns true if the signature is valid, false otherwise.
528 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
529 return meshlink_verify(handle, source, data, len, signature, siglen);
532 /// Set the canonical Address for a node.
533 /** This function sets the canonical Address for a node.
534 * This address is stored permanently until it is changed by another call to this function,
535 * unlike other addresses associated with a node,
536 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
538 * If a canonical Address is set for the local node,
539 * it will be used for the hostname part of generated invitation URLs.
541 * @param node A pointer to a meshlink_node_t describing the node.
542 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
543 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
544 * If it is NULL, the listening port's number will be used.
546 * @return This function returns true if the address was added, false otherwise.
548 bool set_canonical_address(node *node, const char *address, const char *port = NULL) {
549 return meshlink_set_canonical_address(handle, node, address, port);
552 /// Clear the canonical Address for a node.
553 /** This function clears the canonical Address for a node.
555 * @param node A pointer to a struct meshlink_node describing the node.
557 * @return This function returns true if the address was removed, false otherwise.
559 bool clear_canonical_address(node *node) {
560 return meshlink_clear_canonical_address(handle, node);
563 /// Add an Address for the local node.
564 /** This function adds an Address for the local node, which will be used for invitation URLs.
565 * @deprecated This function is deprecated, use set_canonical_address() and/or add_invitation_address().
567 * @param address A string containing the address, which can be either in numeric format or a hostname.
569 * @return This function returns true if the address was added, false otherwise.
571 bool add_address(const char *address) __attribute__((__deprecated__("use set_canonical_address() and/or add_invitation_address() instead"))) {
572 return meshlink_set_canonical_address(handle, get_self(), address, NULL);
575 /** This function performs tries to discover the local node's external address
576 * by contacting the meshlink.io server. If a reverse lookup of the address works,
577 * the FQDN associated with the address will be returned.
579 * Please note that this is function only returns a single address,
580 * even if the local node might have more than one external address.
581 * In that case, there is no control over which address will be selected.
582 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
583 * there is no guarantee that the external address will be valid for an extended period of time.
585 * This function is blocking. It can take several seconds before it returns.
586 * There is no guarantee it will be able to resolve the external address.
587 * Failures might be because by temporary network outages.
589 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
590 * this might return the external address for any working address family.
592 * @return This function returns a pointer to a C string containing the discovered external address,
593 * or NULL if there was an error looking up the address.
594 * After get_external_address() returns, the application is free to overwrite or free this string.
596 bool get_external_address(int family = AF_UNSPEC) {
597 return meshlink_get_external_address_for_family(handle, family);
600 /** This function performs tries to discover the address of the local interface used for outgoing connection.
602 * Please note that this is function only returns a single address,
603 * even if the local node might have more than one external address.
604 * In that case, there is no control over which address will be selected.
605 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
606 * there is no guarantee that the external address will be valid for an extended period of time.
608 * This function will fail if it couldn't find a local address for the given address family.
609 * If hostname resolving is requested, this function may block for a few seconds.
611 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
612 * this might return the external address for any working address family.
614 * @return This function returns a pointer to a C string containing the discovered external address,
615 * or NULL if there was an error looking up the address.
616 * After get_external_address() returns, the application is free to overwrite or free this string.
618 bool get_local_address(int family = AF_UNSPEC) {
619 return meshlink_get_local_address_for_family(handle, family);
622 /// Try to discover the external address for the local node, and add it to its list of addresses.
623 /** This function is equivalent to:
625 * mesh->add_address(mesh->get_external_address());
627 * Read the description of get_external_address() for the limitations of this function.
629 * @return This function returns true if the address was added, false otherwise.
631 bool add_external_address() {
632 return meshlink_add_external_address(handle);
635 /// Get the network port used by the local node.
636 /** This function returns the network port that the local node is listening on.
638 * @return This function returns the port number, or -1 in case of an error.
641 return meshlink_get_port(handle);
644 /// Set the network port used by the local node.
645 /** This function sets the network port that the local node is listening on.
646 * It may only be called when the mesh is not running.
647 * If unsure, call stop() before calling this function.
648 * Also note that if your node is already part of a mesh with other nodes,
649 * that the other nodes may no longer be able to initiate connections to the local node,
650 * since they will try to connect to the previously configured port.
652 * @param port The port number to listen on. This must be between 0 and 65535.
653 * If the port is set to 0, then MeshLink will listen on a port
654 * that is randomly assigned by the operating system every time open() is called.
656 * @return This function returns true if the port was successfully changed
657 * to the desired port, false otherwise. If it returns false, there
658 * is no guarantee that MeshLink is listening on the old port.
660 bool set_port(int port) {
661 return meshlink_set_port(handle, port);
664 /// Set the scheduling granularity of the application
665 /** This should be set to the effective scheduling granularity for the application.
666 * This depends on the scheduling granularity of the operating system, the application's
667 * process priority and whether it is running as realtime or not.
668 * The default value is 10000 (10 milliseconds).
670 * @param granularity The scheduling granularity of the application in microseconds.
672 void set_granularity(long granularity) {
673 meshlink_set_scheduling_granularity(handle, granularity);
676 /// Sets the storage policy used by MeshLink
677 /** This sets the policy MeshLink uses when it has new information about nodes.
678 * By default, all udpates will be stored to disk (unless an ephemeral instance has been opened).
679 * Setting the policy to MESHLINK_STORAGE_KEYS_ONLY, only updates that contain new keys for nodes
680 * are stored, as well as blacklist/whitelist settings.
681 * By setting the policy to MESHLINK_STORAGE_DISABLED, no updates will be stored.
683 * @param policy The storage policy to use.
685 void set_storage_policy(meshlink_storage_policy_t policy) {
686 meshlink_set_storage_policy(handle, policy);
689 /// Use an invitation to join a mesh.
690 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
691 * An invitation can only be used if the local node has never connected to other nodes before.
692 * After a successfully accepted invitation, the name of the local node may have changed.
694 * This function may only be called on a mesh that has not been started yet and which is not already part of an existing mesh.
696 * This function is blocking. It can take several seconds before it returns.
697 * There is no guarantee it will perform a successful join.
698 * Failures might be caused by temporary network outages, or by the invitation having expired.
700 * @param invitation A string containing the invitation URL.
702 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
704 bool join(const char *invitation) {
705 return meshlink_join(handle, invitation);
708 /// Export the local node's key and addresses.
709 /** This function generates a string that contains the local node's public key and one or more IP addresses.
710 * The application can pass it in some way to another node, which can then import it,
711 * granting the local node access to the other node's mesh.
713 * @return This function returns a string that contains the exported key and addresses.
714 * The application should call free() after it has finished using this string.
717 return meshlink_export(handle);
720 /// Import another node's key and addresses.
721 /** This function accepts a string containing the exported public key and addresses of another node.
722 * By importing this data, the local node grants the other node access to its mesh.
724 * @param data A string containing the other node's exported key and addresses.
726 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
728 bool import_key(const char *data) {
729 return meshlink_import(handle, data);
732 /// Forget any information about a node.
733 /** This function allows the local node to forget any information it has about a node,
734 * and if possible will remove any data it has stored on disk about the node.
736 * Any open channels to this node must be closed before calling this function.
738 * After this call returns, the node handle is invalid and may no longer be used, regardless
739 * of the return value of this call.
741 * Note that this function does not prevent MeshLink from actually forgetting about a node,
742 * or re-learning information about a node at a later point in time. It is merely a hint that
743 * the application does not care about this node anymore and that any resources kept could be
746 * \memberof meshlink_node
747 * @param node A pointer to a struct meshlink_node describing the node to be forgotten.
749 * @return This function returns true if all currently known data about the node has been forgotten, false otherwise.
751 bool forget_node(node *node) {
752 return meshlink_forget_node(handle, node);
755 /// Blacklist a node from the mesh.
756 /** This function causes the local node to blacklist another node.
757 * The local node will drop any existing connections to that node,
758 * and will not send data to it nor accept any data received from it any more.
760 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
762 * @return This function returns true if the node has been whitelisted, false otherwise.
764 bool blacklist(node *node) {
765 return meshlink_blacklist(handle, node);
768 /// Blacklist a node from the mesh by name.
769 /** This function causes the local node to blacklist another node by name.
770 * The local node will drop any existing connections to that node,
771 * and will not send data to it nor accept any data received from it any more.
773 * If no node by the given name is known, it is created.
775 * @param name The name of the node to blacklist.
777 * @return This function returns true if the node has been blacklisted, false otherwise.
779 bool blacklist_by_name(const char *name) {
780 return meshlink_blacklist_by_name(handle, name);
783 /// Whitelist a node on the mesh.
784 /** This function causes the local node to whitelist another node.
785 * The local node will allow connections to and from that node,
786 * and will send data to it and accept any data received from it.
788 * @param node A pointer to a meshlink::node describing the node to be whitelisted.
790 * @return This function returns true if the node has been whitelisted, false otherwise.
792 bool whitelist(node *node) {
793 return meshlink_whitelist(handle, node);
796 /// Whitelist a node on the mesh by name.
797 /** This function causes the local node to whitelist a node by name.
798 * The local node will allow connections to and from that node,
799 * and will send data to it and accept any data received from it.
801 * If no node by the given name is known, it is created.
802 * This is useful if new nodes are blacklisted by default.
804 * \memberof meshlink_node
805 * @param name The name of the node to whitelist.
807 * @return This function returns true if the node has been whitelisted, false otherwise.
809 bool whitelist_by_name(const char *name) {
810 return meshlink_whitelist_by_name(handle, name);
813 /// Set the poll callback.
814 /** This functions sets the callback that is called whenever data can be sent to another node.
815 * The callback is run in MeshLink's own thread.
816 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
817 * to pass data to or from the application's thread.
818 * The callback should also not block itself and return as quickly as possible.
820 * @param channel A handle for the channel.
821 * @param cb A pointer to the function which will be called when data can be sent to another node.
822 * If a NULL pointer is given, the callback will be disabled.
824 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
825 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
828 /// Set the send buffer size of a channel.
829 /** This function sets the desired size of the send buffer.
830 * The default size is 128 kB.
832 * @param channel A handle for the channel.
833 * @param size The desired size for the send buffer.
834 * If a NULL pointer is given, the callback will be disabled.
836 void set_channel_sndbuf(channel *channel, size_t size) {
837 meshlink_set_channel_sndbuf(handle, channel, size);
840 /// Set the receive buffer size of a channel.
841 /** This function sets the desired size of the receive buffer.
842 * The default size is 128 kB.
844 * @param channel A handle for the channel.
845 * @param size The desired size for the send buffer.
846 * If a NULL pointer is given, the callback will be disabled.
848 void set_channel_rcvbuf(channel *channel, size_t size) {
849 meshlink_set_channel_rcvbuf(handle, channel, size);
852 /// Set the flags of a channel.
853 /** This function allows changing some of the channel flags.
854 * Currently only MESHLINK_CHANNEL_NO_PARTIAL and MESHLINK_CHANNEL_DROP_LATE are supported, other flags are ignored.
855 * These flags only affect the local side of the channel with the peer.
856 * The changes take effect immediately.
858 * @param channel A handle for the channel.
859 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
861 void set_channel_flags(channel *channel, uint32_t flags) {
862 meshlink_set_channel_flags(handle, channel, flags);
865 /// Set the send buffer storage of a channel.
866 /** This function provides MeshLink with a send buffer allocated by the application.
868 * @param channel A handle for the channel.
869 * @param buf A pointer to the start of the buffer.
870 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
871 * @param size The size of the buffer.
873 void set_channel_sndbuf_storage(channel *channel, void *buf, size_t size) {
874 meshlink_set_channel_sndbuf_storage(handle, channel, buf, size);
877 /// Set the receive buffer storage of a channel.
878 /** This function provides MeshLink with a receive buffer allocated by the application.
880 * @param channel A handle for the channel.
881 * @param buf A pointer to the start of the buffer.
882 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
883 * @param size The size of the buffer.
885 void set_channel_rcvbuf_storage(channel *channel, void *buf, size_t size) {
886 meshlink_set_channel_rcvbuf_storage(handle, channel, buf, size);
889 /// Set the connection timeout used for channels to the given node.
890 /** This sets the timeout after which unresponsive channels will be reported as closed.
891 * The timeout is set for all current and future channels to the given node.
893 * @param node The node to set the channel timeout for.
894 * @param timeout The timeout in seconds after which unresponsive channels will be reported as closed.
895 * The default is 60 seconds.
897 void set_node_channel_timeout(node *node, int timeout) {
898 meshlink_set_node_channel_timeout(handle, node, timeout);
901 /// Open a reliable stream channel to another node.
902 /** This function is called whenever a remote node wants to open a channel to the local node.
903 * The application then has to decide whether to accept or reject this channel.
905 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
906 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
908 * @param node The node to which this channel is being initiated.
909 * @param port The port number the peer wishes to connect to.
910 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
911 * @param data A pointer to a buffer containing data to already queue for sending.
912 * @param len The length of the data.
913 * If len is 0, the data pointer is copied into the channel's priv member.
914 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
916 * @return A handle for the channel, or NULL in case of an error.
918 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
919 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
920 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
924 /// Open a reliable stream channel to another node.
925 /** This function is called whenever a remote node wants to open a channel to the local node.
926 * The application then has to decide whether to accept or reject this channel.
928 * This function sets the channel receive callback to channel_receive_trampoline,
929 * which in turn calls channel_receive.
931 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
932 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
934 * @param node The node to which this channel is being initiated.
935 * @param port The port number the peer wishes to connect to.
936 * @param data A pointer to a buffer containing data to already queue for sending.
937 * @param len The length of the data.
938 * If len is 0, the data pointer is copied into the channel's priv member.
939 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
941 * @return A handle for the channel, or NULL in case of an error.
943 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
944 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
945 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
949 /// Partially close a reliable stream channel.
950 /** This shuts down the read or write side of a channel, or both, without closing the handle.
951 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
952 * but still allows waiting for incoming data from the remote node.
954 * @param channel A handle for the channel.
955 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
957 void channel_shutdown(channel *channel, int direction) {
958 return meshlink_channel_shutdown(handle, channel, direction);
961 /// Close a reliable stream channel.
962 /** This informs the remote node that the local node has finished sending all data on the channel.
963 * It also causes the local node to stop accepting incoming data from the remote node.
964 * Afterwards, the channel handle is invalid and must not be used any more.
966 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
967 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
969 * @param channel A handle for the channel.
971 void channel_close(meshlink_channel_t *channel) {
972 return meshlink_channel_close(handle, channel);
975 /// Abort a reliable stream channel.
976 /** This aborts a channel.
977 * Data that was in the send and receive buffers is dropped, so potentially there is some data that
978 * was sent on this channel that will not be received by the peer.
979 * Afterwards, the channel handle is invalid and must not be used any more.
981 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
982 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
984 * @param channel A handle for the channel.
986 void channel_abort(meshlink_channel_t *channel) {
987 return meshlink_channel_abort(handle, channel);
990 /// Transmit data on a channel
991 /** This queues data to send to the remote node.
993 * @param channel A handle for the channel.
994 * @param data A pointer to a buffer containing data sent by the source.
995 * @param len The length of the data.
997 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
998 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
999 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
1001 ssize_t channel_send(channel *channel, void *data, size_t len) {
1002 return meshlink_channel_send(handle, channel, data, len);
1005 /// Transmit data on a channel asynchronously
1006 /** This registers a buffer that will be used to send data to the remote node.
1007 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
1008 * While there are still buffers with unsent data, the poll callback will not be called.
1010 * @param channel A handle for the channel.
1011 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
1012 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
1013 * until the callback routine is called.
1014 * @param len The length of the data, or 0 if there is no data to send.
1015 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
1016 * @param priv A private pointer which was set by the application when submitting the buffer.
1018 * @return True if the buffer was enqueued, false otherwise.
1020 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
1021 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
1024 /// Transmit data on a channel asynchronously from a filedescriptor
1025 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
1026 * The callback may be returned early if there is an error reading from the filedescriptor.
1027 * While there is still with unsent data, the poll callback will not be called.
1029 * @param channel A handle for the channel.
1030 * @param fd A file descriptor from which data will be read.
1031 * @param len The length of the data, or 0 if there is no data to send.
1032 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
1033 * @param priv A private pointer which was set by the application when submitting the buffer.
1035 * @return True if the buffer was enqueued, false otherwise.
1037 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
1038 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
1041 /// Receive data on a channel asynchronously
1042 /** This registers a buffer that will be filled with incoming channel data.
1043 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
1044 * While there are still buffers that have not been filled, the receive callback will not be called.
1046 * @param channel A handle for the channel.
1047 * @param data A pointer to a buffer that will be filled with incoming data.
1048 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
1049 * until the callback routine is called.
1050 * @param len The length of the data.
1051 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
1052 * @param priv A private pointer which was set by the application when submitting the buffer.
1054 * @return True if the buffer was enqueued, false otherwise.
1056 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
1057 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
1060 /// Receive data on a channel asynchronously and send it to a filedescriptor
1061 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
1062 * The callback may be returned early if there is an error writing to the filedescriptor.
1063 * While there is still unread data, the receive callback will not be called.
1065 * @param channel A handle for the channel.
1066 * @param fd A file descriptor to which data will be written.
1067 * @param len The length of the data.
1068 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
1069 * @param priv A private pointer which was set by the application when submitting the buffer.
1071 * @return True if the buffer was enqueued, false otherwise.
1073 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
1074 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
1077 /// Get the amount of bytes in the send buffer.
1078 /** This returns the amount of bytes in the send buffer.
1079 * These bytes have not been received by the peer yet.
1081 * @param channel A handle for the channel.
1083 * @return The amount of un-ACKed bytes in the send buffer.
1085 size_t channel_get_sendq(channel *channel) {
1086 return meshlink_channel_get_sendq(handle, channel);
1089 /// Get the amount of bytes in the receive buffer.
1090 /** This returns the amount of bytes in the receive buffer.
1091 * These bytes have not been processed by the application yet.
1093 * @param channel A handle for the channel.
1095 * @return The amount of bytes in the receive buffer.
1097 size_t channel_get_recvq(channel *channel) {
1098 return meshlink_channel_get_recvq(handle, channel);
1101 /// Get the maximum segment size of a channel.
1102 /** This returns the amount of bytes that can be sent at once for channels with UDP semantics.
1104 * @param channel A handle for the channel.
1106 * @return The amount of bytes in the receive buffer.
1108 size_t channel_get_mss(channel *channel) {
1109 return meshlink_channel_get_mss(handle, channel);
1112 /// Enable or disable zeroconf discovery of local peers
1113 /** This controls whether zeroconf discovery using the Catta library will be
1114 * enabled to search for peers on the local network. By default, it is enabled.
1116 * @param enable Set to true to enable discovery, false to disable.
1118 void enable_discovery(bool enable = true) {
1119 meshlink_enable_discovery(handle, enable);
1122 /// Inform MeshLink that the local network configuration might have changed
1123 /** This is intended to be used when there is no way for MeshLink to get notifications of local network changes.
1124 * It forces MeshLink to scan all network interfaces for changes in up/down status and new/removed addresses,
1125 * and will immediately check if all connections to other nodes are still alive.
1127 void hint_network_change() {
1128 meshlink_hint_network_change(handle);
1131 /// Set device class timeouts
1132 /** This sets the ping interval and timeout for a given device class.
1134 * @param devclass The device class to update
1135 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
1136 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
1137 * The timeout must be smaller than the interval.
1139 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout) {
1140 meshlink_set_dev_class_timeouts(handle, devclass, pinginterval, pingtimeout);
1143 /// Set device class fast retry period
1144 /** This sets the fast retry period for a given device class.
1145 * During this period after the last time the mesh becomes unreachable, connections are tried once a second.
1147 * @param devclass The device class to update
1148 * @param fast_retry_period The period during which fast connection retries are done. The default is 0.
1150 void set_dev_class_fast_retry_period(dev_class_t devclass, int fast_retry_period) {
1151 meshlink_set_dev_class_fast_retry_period(handle, devclass, fast_retry_period);
1154 /// Set device class maximum timeout
1155 /** This sets the maximum timeout for outgoing connection retries for a given device class.
1157 * @param devclass The device class to update
1158 * @param maxtimeout The maximum timeout between reconnection attempts, in seconds. The default is 900.
1160 void set_dev_class_maxtimeout(dev_class_t devclass, int maxtimeout) {
1161 meshlink_set_dev_class_maxtimeout(handle, devclass, maxtimeout);
1164 /// Set which order invitations are committed
1165 /** This determines in which order configuration files are written to disk during an invitation.
1166 * By default, the invitee saves the configuration to disk first, then the inviter.
1167 * By calling this function with @a inviter_commits_first set to true, the order is reversed.
1169 * @param inviter_commits_first If true, then the node that invited a peer will commit data to disk first.
1171 void set_inviter_commits_first(bool inviter_commits_first) {
1172 meshlink_set_inviter_commits_first(handle, inviter_commits_first);
1175 /// Set the URL used to discover the host's external address
1176 /** For generating invitation URLs, MeshLink can look up the externally visible address of the local node.
1177 * It does so by querying an external service. By default, this is http://meshlink.io/host.cgi.
1178 * Only URLs starting with http:// are supported.
1180 * @param url The URL to use for external address queries, or NULL to revert back to the default URL.
1182 void set_external_address_discovery_url(const char *url) {
1183 meshlink_set_external_address_discovery_url(handle, url);
1188 mesh(const mesh &) /* TODO: C++11: = delete */;
1189 void operator=(const mesh &) /* TODO: C++11: = delete */;
1191 /// static callback trampolines:
1192 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
1193 if(!(handle->priv)) {
1197 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1198 that->receive(static_cast<node *>(source), data, length);
1201 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
1202 if(!(handle->priv)) {
1206 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1207 that->node_status(static_cast<node *>(peer), reachable);
1210 static void node_pmtu_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, uint16_t pmtu) {
1211 if(!(handle->priv)) {
1215 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1216 that->node_pmtu(static_cast<node *>(peer), pmtu);
1219 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1220 if(!(handle->priv)) {
1224 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1225 that->node_duplicate(static_cast<node *>(peer));
1228 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
1229 if(!(handle->priv)) {
1233 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1234 that->log(level, message);
1237 static void error_trampoline(meshlink_handle_t *handle, meshlink_errno_t meshlink_errno) {
1238 if(!(handle->priv)) {
1242 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1243 that->error(meshlink_errno);
1246 static void blacklisted_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1247 if(!(handle->priv)) {
1251 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1252 that->blacklisted(static_cast<node *>(peer));
1255 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1256 if(!(handle->priv)) {
1260 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1261 that->connection_try(static_cast<node *>(peer));
1264 static bool channel_listen_trampoline(meshlink_handle_t *handle, meshlink_node_t *node, uint16_t port) {
1265 if(!(handle->priv)) {
1269 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1270 return that->channel_listen(static_cast<meshlink::node *>(node), port);
1273 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
1274 if(!(handle->priv)) {
1278 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1279 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
1282 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
1283 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
1289 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
1290 if(!(handle->priv)) {
1294 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1295 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
1298 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
1299 if(!(handle->priv)) {
1303 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1304 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
1307 meshlink_handle_t *handle;
1310 static inline const char *strerror(errno_t err = meshlink_errno) {
1311 return meshlink_strerror(err);
1314 /// Destroy a MeshLink instance.
1315 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
1316 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
1319 * @param confbase The directory in which MeshLink stores its configuration files.
1320 * After the function returns, the application is free to overwrite or free @a confbase @a.
1322 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
1324 static inline bool destroy(const char *confbase) {
1325 return meshlink_destroy(confbase);