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 a meta-connection attempt is made.
278 virtual void connection_try(node *peer) {
283 /// This functions is called to determine if we are listening for incoming channels.
285 * The function is run in MeshLink's own thread.
286 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
287 * to pass data to or from the application's thread.
288 * The callback should also not block itself and return as quickly as possible.
290 * @param node A handle for the node that wants to open a channel.
291 * @param port The port number the peer wishes to connect to.
293 * @return This function should return true if the application accepts the incoming channel, false otherwise.
295 virtual bool channel_listen(node *node, uint16_t port) {
296 /* by default accept all channels */
302 /// This functions is called whenever another node attempts to open a channel to the local node.
304 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
305 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
308 * The function is run in MeshLink's own thread.
309 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
310 * to pass data to or from the application's thread.
311 * The callback should also not block itself and return as quickly as possible.
313 * @param channel A handle for the incoming channel.
314 * @param port The port number the peer wishes to connect to.
315 * @param data A pointer to a buffer containing data already received. (Not yet used.)
316 * @param len The length of the data. (Not yet used.)
318 * @return This function should return true if the application accepts the incoming channel, false otherwise.
319 * If returning false, the channel is invalid and may not be used anymore.
321 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
322 /* by default reject all channels */
330 /// This function is called by Meshlink for receiving data from a channel.
332 * The function is run in MeshLink's own thread.
333 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
334 * to pass data to or from the application's thread.
335 * The callback should also not block itself and return as quickly as possible.
337 * @param channel A handle for the channel.
338 * @param data A pointer to a buffer containing data sent by the source.
339 * @param len The length of the data.
341 virtual void channel_receive(channel *channel, const void *data, size_t len) {
348 /// This function is called by Meshlink when data can be send on a channel.
350 * The function is run in MeshLink's own thread.
351 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
352 * to pass data to or from the application's thread.
354 * The callback should also not block itself and return as quickly as possible.
355 * @param channel A handle for the channel.
356 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
358 virtual void channel_poll(channel *channel, size_t len) {
365 /** This function causes MeshLink to open network sockets, make outgoing connections, and
366 * create a new thread, which will handle all network I/O.
368 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
371 meshlink_set_receive_cb(handle, &receive_trampoline);
372 meshlink_set_node_status_cb(handle, &node_status_trampoline);
373 meshlink_set_node_pmtu_cb(handle, &node_pmtu_trampoline);
374 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
375 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
376 meshlink_set_error_cb(handle, &error_trampoline);
377 meshlink_set_channel_listen_cb(handle, &channel_listen_trampoline);
378 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
379 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
380 return meshlink_start(handle);
384 /** This function causes MeshLink to disconnect from all other nodes,
385 * close all sockets, and shut down its own thread.
388 meshlink_stop(handle);
391 /// Send data to another node.
392 /** This functions sends one packet of data to another node in the mesh.
393 * The packet is sent using UDP semantics, which means that
394 * the packet is sent as one unit and is received as one unit,
395 * and that there is no guarantee that the packet will arrive at the destination.
396 * The application should take care of getting an acknowledgement and retransmission if necessary.
398 * @param destination A pointer to a meshlink::node describing the destination for the data.
399 * @param data A pointer to a buffer containing the data to be sent to the source.
400 * @param len The length of the data.
401 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
402 * A return value of true does not guarantee that the message will actually arrive at the destination.
404 bool send(node *destination, const void *data, unsigned int len) {
405 return meshlink_send(handle, destination, data, len);
408 /// Get a handle for a specific node.
409 /** This function returns a handle for the node with the given name.
411 * @param name The name of the node for which a handle is requested.
413 * @return A pointer to a meshlink::node which represents the requested node,
414 * or NULL if the requested node does not exist.
416 node *get_node(const char *name) {
417 return (node *)meshlink_get_node(handle, name);
420 /// Get a node's reachability status.
421 /** This function returns the current reachability of a given node, and the times of the last state changes.
422 * If a given state change never happened, the time returned will be 0.
424 * @param node A pointer to a meshlink::node describing the node.
425 * @param last_reachable A pointer to a time_t variable that will be filled in with the last time the node became reachable.
426 * @param last_unreachable A pointer to a time_t variable that will be filled in with the last time the node became unreachable.
428 * @return This function returns true if the node is currently reachable, false otherwise.
430 bool get_node_reachability(node *node, time_t *last_reachable = NULL, time_t *last_unreachable = NULL) {
431 return meshlink_get_node_reachability(handle, node, last_reachable, last_unreachable);
434 /// Get a handle for a specific submesh.
435 /** This function returns a handle for the submesh with the given name.
437 * @param name The name of the submesh for which a handle is requested.
439 * @return A pointer to a meshlink::submesh which represents the requested submesh,
440 * or NULL if the requested submesh does not exist.
442 submesh *get_submesh(const char *name) {
443 return (submesh *)meshlink_get_submesh(handle, name);
446 /// Get a handle for our own node.
447 /** This function returns a handle for the local node.
449 * @return A pointer to a meshlink::node which represents the local node.
452 return (node *)meshlink_get_self(handle);
455 /// Get a list of all nodes.
456 /** This function returns a list with handles for all known nodes.
458 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
459 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
461 * @return The number of known nodes, or -1 in case of an error.
462 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
464 node **get_all_nodes(node **nodes, size_t *nmemb) {
465 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
468 /// Sign data using the local node's MeshLink key.
469 /** This function signs data using the local node's MeshLink key.
470 * The generated signature can be securely verified by other nodes.
472 * @param data A pointer to a buffer containing the data to be signed.
473 * @param len The length of the data to be signed.
474 * @param signature A pointer to a buffer where the signature will be stored.
475 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
477 * @return This function returns true if the signature is valid, false otherwise.
479 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
480 return meshlink_sign(handle, data, len, signature, siglen);
483 /// Verify the signature generated by another node of a piece of data.
484 /** This function verifies the signature that another node generated for a piece of data.
486 * @param source A pointer to a meshlink_node_t describing the source of the signature.
487 * @param data A pointer to a buffer containing the data to be verified.
488 * @param len The length of the data to be verified.
489 * @param signature A pointer to a string containing the signature.
490 * @param siglen The size of the signature.
492 * @return This function returns true if the signature is valid, false otherwise.
494 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
495 return meshlink_verify(handle, source, data, len, signature, siglen);
498 /// Set the canonical Address for a node.
499 /** This function sets the canonical Address for a node.
500 * This address is stored permanently until it is changed by another call to this function,
501 * unlike other addresses associated with a node,
502 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
504 * If a canonical Address is set for the local node,
505 * it will be used for the hostname part of generated invitation URLs.
507 * @param node A pointer to a meshlink_node_t describing the node.
508 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
509 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
510 * If it is NULL, the listening port's number will be used.
512 * @return This function returns true if the address was added, false otherwise.
514 bool set_canonical_address(node *node, const char *address, const char *port = NULL) {
515 return meshlink_set_canonical_address(handle, node, address, port);
518 /// Add an invitation address for the local node.
519 /** This function adds an address for the local node, which will be used only for invitation URLs.
520 * This address is not stored permanently.
521 * Multiple addresses can be added using multiple calls to this function.
523 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
524 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
525 * If it is NULL, the listening port's number will be used.
527 * @return This function returns true if the address was added, false otherwise.
529 bool add_invitation_address(const char *address, const char *port) {
530 return meshlink_add_invitation_address(handle, address, port);
533 /// Clears all invitation address for the local node.
534 /** This function removes all addresses added with meshlink_add_invitation_address().
536 void clear_invitation_addresses() {
537 return meshlink_clear_invitation_addresses(handle);
540 /// Add an Address for the local node.
541 /** This function adds an Address for the local node, which will be used for invitation URLs.
542 * @deprecated This function is deprecated, use set_canonical_address() and/or add_invitation_address().
544 * @param address A string containing the address, which can be either in numeric format or a hostname.
546 * @return This function returns true if the address was added, false otherwise.
548 bool add_address(const char *address) __attribute__((__deprecated__("use set_canonical_address() and/or add_invitation_address() instead"))) {
549 return meshlink_set_canonical_address(handle, get_self(), address, NULL);
552 /** This function performs tries to discover the local node's external address
553 * by contacting the meshlink.io server. If a reverse lookup of the address works,
554 * the FQDN associated with the address will be returned.
556 * Please note that this is function only returns a single address,
557 * even if the local node might have more than one external address.
558 * In that case, there is no control over which address will be selected.
559 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
560 * there is no guarantee that the external address will be valid for an extended period of time.
562 * This function is blocking. It can take several seconds before it returns.
563 * There is no guarantee it will be able to resolve the external address.
564 * Failures might be because by temporary network outages.
566 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
567 * this might return the external address for any working address family.
569 * @return This function returns a pointer to a C string containing the discovered external address,
570 * or NULL if there was an error looking up the address.
571 * After get_external_address() returns, the application is free to overwrite or free this string.
573 bool get_external_address(int family = AF_UNSPEC) {
574 return meshlink_get_external_address_for_family(handle, family);
577 /** This function performs tries to discover the address of the local interface used for outgoing connection.
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 will fail if it couldn't find a local address for the given address family.
586 * If hostname resolving is requested, this function may block for a few seconds.
588 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
589 * this might return the external address for any working address family.
591 * @return This function returns a pointer to a C string containing the discovered external address,
592 * or NULL if there was an error looking up the address.
593 * After get_external_address() returns, the application is free to overwrite or free this string.
595 bool get_local_address(int family = AF_UNSPEC) {
596 return meshlink_get_local_address_for_family(handle, family);
599 /// Try to discover the external address for the local node, and add it to its list of addresses.
600 /** This function is equivalent to:
602 * mesh->add_address(mesh->get_external_address());
604 * Read the description of get_external_address() for the limitations of this function.
606 * @return This function returns true if the address was added, false otherwise.
608 bool add_external_address() {
609 return meshlink_add_external_address(handle);
612 /// Get the network port used by the local node.
613 /** This function returns the network port that the local node is listening on.
615 * @return This function returns the port number, or -1 in case of an error.
618 return meshlink_get_port(handle);
621 /// Set the network port used by the local node.
622 /** This function sets the network port that the local node is listening on.
623 * It may only be called when the mesh is not running.
624 * If unsure, call stop() before calling this function.
625 * Also note that if your node is already part of a mesh with other nodes,
626 * that the other nodes may no longer be able to initiate connections to the local node,
627 * since they will try to connect to the previously configured port.
629 * @param port The port number to listen on. This must be between 0 and 65535.
630 * If the port is set to 0, then MeshLink will listen on a port
631 * that is randomly assigned by the operating system every time open() is called.
633 * @return This function returns true if the port was successfully changed
634 * to the desired port, false otherwise. If it returns false, there
635 * is no guarantee that MeshLink is listening on the old port.
637 bool set_port(int port) {
638 return meshlink_set_port(handle, port);
641 /// Set the timeout for invitations.
642 /** This function sets the timeout for invitations.
643 * The timeout is retroactively applied to all outstanding invitations.
645 * @param timeout The timeout for invitations in seconds.
647 void set_invitation_timeout(int timeout) {
648 meshlink_set_invitation_timeout(handle, timeout);
651 /// Set the scheduling granularity of the application
652 /** This should be set to the effective scheduling granularity for the application.
653 * This depends on the scheduling granularity of the operating system, the application's
654 * process priority and whether it is running as realtime or not.
655 * The default value is 10000 (10 milliseconds).
657 * @param granularity The scheduling granularity of the application in microseconds.
659 void set_granularity(long granularity) {
660 meshlink_set_scheduling_granularity(handle, granularity);
663 /// Invite another node into the mesh.
664 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
665 * The generated invitation is a string containing a URL.
666 * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
667 * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
669 * @param submesh A handle to the submesh to put the invitee in.
670 * @param name The name that the invitee will use in the mesh.
671 * @param flags A bitwise-or'd combination of flags that controls how the URL is generated.
673 * @return This function returns a string that contains the invitation URL.
674 * The application should call free() after it has finished using the URL.
676 char *invite(submesh *submesh, const char *name, uint32_t flags = 0) {
677 return meshlink_invite_ex(handle, submesh, name, flags);
680 /// Use an invitation to join a mesh.
681 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
682 * An invitation can only be used if the local node has never connected to other nodes before.
683 * After a successfully accepted invitation, the name of the local node may have changed.
685 * 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.
687 * This function is blocking. It can take several seconds before it returns.
688 * There is no guarantee it will perform a successful join.
689 * Failures might be caused by temporary network outages, or by the invitation having expired.
691 * @param invitation A string containing the invitation URL.
693 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
695 bool join(const char *invitation) {
696 return meshlink_join(handle, invitation);
699 /// Export the local node's key and addresses.
700 /** This function generates a string that contains the local node's public key and one or more IP addresses.
701 * The application can pass it in some way to another node, which can then import it,
702 * granting the local node access to the other node's mesh.
704 * @return This function returns a string that contains the exported key and addresses.
705 * The application should call free() after it has finished using this string.
708 return meshlink_export(handle);
711 /// Import another node's key and addresses.
712 /** This function accepts a string containing the exported public key and addresses of another node.
713 * By importing this data, the local node grants the other node access to its mesh.
715 * @param data A string containing the other node's exported key and addresses.
717 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
719 bool import_key(const char *data) {
720 return meshlink_import(handle, data);
723 /// Forget any information about a node.
724 /** This function allows the local node to forget any information it has about a node,
725 * and if possible will remove any data it has stored on disk about the node.
727 * Any open channels to this node must be closed before calling this function.
729 * After this call returns, the node handle is invalid and may no longer be used, regardless
730 * of the return value of this call.
732 * Note that this function does not prevent MeshLink from actually forgetting about a node,
733 * or re-learning information about a node at a later point in time. It is merely a hint that
734 * the application does not care about this node anymore and that any resources kept could be
737 * \memberof meshlink_node
738 * @param node A pointer to a struct meshlink_node describing the node to be forgotten.
740 * @return This function returns true if all currently known data about the node has been forgotten, false otherwise.
742 bool forget_node(node *node) {
743 return meshlink_forget_node(handle, node);
746 /// Blacklist a node from the mesh.
747 /** This function causes the local node to blacklist another node.
748 * The local node will drop any existing connections to that node,
749 * and will not send data to it nor accept any data received from it any more.
751 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
753 * @return This function returns true if the node has been whitelisted, false otherwise.
755 bool blacklist(node *node) {
756 return meshlink_blacklist(handle, node);
759 /// Blacklist a node from the mesh by name.
760 /** This function causes the local node to blacklist another node by name.
761 * The local node will drop any existing connections to that node,
762 * and will not send data to it nor accept any data received from it any more.
764 * If no node by the given name is known, it is created.
766 * @param name The name of the node to blacklist.
768 * @return This function returns true if the node has been blacklisted, false otherwise.
770 bool blacklist_by_name(const char *name) {
771 return meshlink_blacklist_by_name(handle, name);
774 /// Whitelist a node on the mesh.
775 /** This function causes the local node to whitelist another node.
776 * The local node will allow connections to and from that node,
777 * and will send data to it and accept any data received from it.
779 * @param node A pointer to a meshlink::node describing the node to be whitelisted.
781 * @return This function returns true if the node has been whitelisted, false otherwise.
783 bool whitelist(node *node) {
784 return meshlink_whitelist(handle, node);
787 /// Whitelist a node on the mesh by name.
788 /** This function causes the local node to whitelist a node by name.
789 * The local node will allow connections to and from that node,
790 * and will send data to it and accept any data received from it.
792 * If no node by the given name is known, it is created.
793 * This is useful if new nodes are blacklisted by default.
795 * \memberof meshlink_node
796 * @param name The name of the node to whitelist.
798 * @return This function returns true if the node has been whitelisted, false otherwise.
800 bool whitelist_by_name(const char *name) {
801 return meshlink_whitelist_by_name(handle, name);
804 /// Set the poll callback.
805 /** This functions sets the callback that is called whenever data can be sent to another node.
806 * The callback is run in MeshLink's own thread.
807 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
808 * to pass data to or from the application's thread.
809 * The callback should also not block itself and return as quickly as possible.
811 * @param channel A handle for the channel.
812 * @param cb A pointer to the function which will be called when data can be sent to another node.
813 * If a NULL pointer is given, the callback will be disabled.
815 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
816 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
819 /// Set the send buffer size of a channel.
820 /** This function sets the desired size of the send buffer.
821 * The default size is 128 kB.
823 * @param channel A handle for the channel.
824 * @param size The desired size for the send buffer.
825 * If a NULL pointer is given, the callback will be disabled.
827 void set_channel_sndbuf(channel *channel, size_t size) {
828 meshlink_set_channel_sndbuf(handle, channel, size);
831 /// Set the receive buffer size of a channel.
832 /** This function sets the desired size of the receive buffer.
833 * The default size is 128 kB.
835 * @param channel A handle for the channel.
836 * @param size The desired size for the send buffer.
837 * If a NULL pointer is given, the callback will be disabled.
839 void set_channel_rcvbuf(channel *channel, size_t size) {
840 meshlink_set_channel_rcvbuf(handle, channel, size);
843 /// Set the connection timeout used for channels to the given node.
844 /** This sets the timeout after which unresponsive channels will be reported as closed.
845 * The timeout is set for all current and future channels to the given node.
847 * @param node The node to set the channel timeout for.
848 * @param timeout The timeout in seconds after which unresponsive channels will be reported as closed.
849 * The default is 60 seconds.
851 void set_node_channel_timeout(node *node, int timeout) {
852 meshlink_set_node_channel_timeout(handle, node, timeout);
855 /// Open a reliable stream channel to another node.
856 /** This function is called whenever a remote node wants to open a channel to the local node.
857 * The application then has to decide whether to accept or reject this channel.
859 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
860 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
862 * @param node The node to which this channel is being initiated.
863 * @param port The port number the peer wishes to connect to.
864 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
865 * @param data A pointer to a buffer containing data to already queue for sending.
866 * @param len The length of the data.
867 * If len is 0, the data pointer is copied into the channel's priv member.
868 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
870 * @return A handle for the channel, or NULL in case of an error.
872 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
873 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
874 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
878 /// Open a reliable stream channel to another node.
879 /** This function is called whenever a remote node wants to open a channel to the local node.
880 * The application then has to decide whether to accept or reject this channel.
882 * This function sets the channel receive callback to channel_receive_trampoline,
883 * which in turn calls channel_receive.
885 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
886 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
888 * @param node The node to which this channel is being initiated.
889 * @param port The port number the peer wishes to connect to.
890 * @param data A pointer to a buffer containing data to already queue for sending.
891 * @param len The length of the data.
892 * If len is 0, the data pointer is copied into the channel's priv member.
893 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
895 * @return A handle for the channel, or NULL in case of an error.
897 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
898 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
899 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
903 /// Partially close a reliable stream channel.
904 /** This shuts down the read or write side of a channel, or both, without closing the handle.
905 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
906 * but still allows waiting for incoming data from the remote node.
908 * @param channel A handle for the channel.
909 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
911 void channel_shutdown(channel *channel, int direction) {
912 return meshlink_channel_shutdown(handle, channel, direction);
915 /// Close a reliable stream channel.
916 /** This informs the remote node that the local node has finished sending all data on the channel.
917 * It also causes the local node to stop accepting incoming data from the remote node.
918 * Afterwards, the channel handle is invalid and must not be used any more.
920 * @param channel A handle for the channel.
922 void channel_close(meshlink_channel_t *channel) {
923 return meshlink_channel_close(handle, channel);
926 /// Transmit data on a channel
927 /** This queues data to send to the remote node.
929 * @param channel A handle for the channel.
930 * @param data A pointer to a buffer containing data sent by the source.
931 * @param len The length of the data.
933 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
934 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
935 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
937 ssize_t channel_send(channel *channel, void *data, size_t len) {
938 return meshlink_channel_send(handle, channel, data, len);
941 /// Transmit data on a channel asynchronously
942 /** This registers a buffer that will be used to send data to the remote node.
943 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
944 * While there are still buffers with unsent data, the poll callback will not be called.
946 * @param channel A handle for the channel.
947 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
948 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
949 * until the callback routine is called.
950 * @param len The length of the data, or 0 if there is no data to send.
951 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
952 * @param priv A private pointer which was set by the application when submitting the buffer.
954 * @return True if the buffer was enqueued, false otherwise.
956 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
957 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
960 /// Transmit data on a channel asynchronously from a filedescriptor
961 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
962 * The callback may be returned early if there is an error reading from the filedescriptor.
963 * While there is still with unsent data, the poll callback will not be called.
965 * @param channel A handle for the channel.
966 * @param fd A file descriptor from which data will be read.
967 * @param len The length of the data, or 0 if there is no data to send.
968 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
969 * @param priv A private pointer which was set by the application when submitting the buffer.
971 * @return True if the buffer was enqueued, false otherwise.
973 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
974 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
977 /// Receive data on a channel asynchronously
978 /** This registers a buffer that will be filled with incoming channel data.
979 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
980 * While there are still buffers that have not been filled, the receive callback will not be called.
982 * @param channel A handle for the channel.
983 * @param data A pointer to a buffer that will be filled with incoming data.
984 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
985 * until the callback routine is called.
986 * @param len The length of the data.
987 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
988 * @param priv A private pointer which was set by the application when submitting the buffer.
990 * @return True if the buffer was enqueued, false otherwise.
992 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
993 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
996 /// Receive data on a channel asynchronously and send it to a filedescriptor
997 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
998 * The callback may be returned early if there is an error writing to the filedescriptor.
999 * While there is still unread data, the receive callback will not be called.
1001 * @param channel A handle for the channel.
1002 * @param fd A file descriptor to which data will be written.
1003 * @param len The length of the data.
1004 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
1005 * @param priv A private pointer which was set by the application when submitting the buffer.
1007 * @return True if the buffer was enqueued, false otherwise.
1009 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
1010 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
1013 /// Get the amount of bytes in the send buffer.
1014 /** This returns the amount of bytes in the send buffer.
1015 * These bytes have not been received by the peer yet.
1017 * @param channel A handle for the channel.
1019 * @return The amount of un-ACKed bytes in the send buffer.
1021 size_t channel_get_sendq(channel *channel) {
1022 return meshlink_channel_get_sendq(handle, channel);
1025 /// Get the amount of bytes in the receive buffer.
1026 /** This returns the amount of bytes in the receive buffer.
1027 * These bytes have not been processed by the application yet.
1029 * @param channel A handle for the channel.
1031 * @return The amount of bytes in the receive buffer.
1033 size_t channel_get_recvq(channel *channel) {
1034 return meshlink_channel_get_recvq(handle, channel);
1037 /// Get the maximum segment size of a channel.
1038 /** This returns the amount of bytes that can be sent at once for channels with UDP semantics.
1040 * @param channel A handle for the channel.
1042 * @return The amount of bytes in the receive buffer.
1044 size_t channel_get_mss(channel *channel) {
1045 return meshlink_channel_get_mss(handle, channel);
1048 /// Enable or disable zeroconf discovery of local peers
1049 /** This controls whether zeroconf discovery using the Catta library will be
1050 * enabled to search for peers on the local network. By default, it is enabled.
1052 * @param enable Set to true to enable discovery, false to disable.
1054 void enable_discovery(bool enable = true) {
1055 meshlink_enable_discovery(handle, enable);
1058 /// Set device class timeouts
1059 /** This sets the ping interval and timeout for a given device class.
1061 * @param devclass The device class to update
1062 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
1063 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
1064 * The timeout must be smaller than the interval.
1066 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout) {
1067 meshlink_set_dev_class_timeouts(handle, devclass, pinginterval, pingtimeout);
1070 /// Set device class fast retry period
1071 /** This sets the fast retry period for a given device class.
1072 * During this period after the last time the mesh becomes unreachable, connections are tried once a second.
1074 * @param devclass The device class to update
1075 * @param fast_retry_period The period during which fast connection retries are done. The default is 0.
1077 void set_dev_class_fast_retry_period(dev_class_t devclass, int fast_retry_period) {
1078 meshlink_set_dev_class_fast_retry_period(handle, devclass, fast_retry_period);
1081 /// Set device class maximum timeout
1082 /** This sets the maximum timeout for outgoing connection retries for a given device class.
1084 * @param devclass The device class to update
1085 * @param maxtimeout The maximum timeout between reconnection attempts, in seconds. The default is 900.
1087 void set_dev_class_maxtimeout(dev_class_t devclass, int maxtimeout) {
1088 meshlink_set_dev_class_maxtimeout(handle, devclass, maxtimeout);
1091 /// Set which order invitations are committed
1092 /** This determines in which order configuration files are written to disk during an invitation.
1093 * By default, the invitee saves the configuration to disk first, then the inviter.
1094 * By calling this function with @a inviter_commits_first set to true, the order is reversed.
1096 * @param inviter_commits_first If true, then the node that invited a peer will commit data to disk first.
1098 void set_inviter_commits_first(bool inviter_commits_first) {
1099 meshlink_set_inviter_commits_first(handle, inviter_commits_first);
1102 /// Set the URL used to discover the host's external address
1103 /** For generating invitation URLs, MeshLink can look up the externally visible address of the local node.
1104 * It does so by querying an external service. By default, this is http://meshlink.io/host.cgi.
1105 * Only URLs starting with http:// are supported.
1107 * @param url The URL to use for external address queries, or NULL to revert back to the default URL.
1109 void set_external_address_discovery_url(const char *url) {
1110 meshlink_set_external_address_discovery_url(handle, url);
1115 mesh(const mesh &) /* TODO: C++11: = delete */;
1116 void operator=(const mesh &) /* TODO: C++11: = delete */;
1118 /// static callback trampolines:
1119 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
1120 if(!(handle->priv)) {
1124 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1125 that->receive(static_cast<node *>(source), data, length);
1128 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
1129 if(!(handle->priv)) {
1133 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1134 that->node_status(static_cast<node *>(peer), reachable);
1137 static void node_pmtu_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, uint16_t pmtu) {
1138 if(!(handle->priv)) {
1142 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1143 that->node_pmtu(static_cast<node *>(peer), pmtu);
1146 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1147 if(!(handle->priv)) {
1151 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1152 that->node_duplicate(static_cast<node *>(peer));
1155 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
1156 if(!(handle->priv)) {
1160 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1161 that->log(level, message);
1164 static void error_trampoline(meshlink_handle_t *handle, meshlink_errno_t meshlink_errno) {
1165 if(!(handle->priv)) {
1169 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1170 that->error(meshlink_errno);
1173 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1174 if(!(handle->priv)) {
1178 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1179 that->connection_try(static_cast<node *>(peer));
1182 static bool channel_listen_trampoline(meshlink_handle_t *handle, meshlink_node_t *node, uint16_t port) {
1183 if(!(handle->priv)) {
1187 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1188 return that->channel_listen(static_cast<meshlink::node *>(node), port);
1191 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
1192 if(!(handle->priv)) {
1196 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1197 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
1200 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
1201 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
1207 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
1208 if(!(handle->priv)) {
1212 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1213 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
1216 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
1217 if(!(handle->priv)) {
1221 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1222 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
1225 meshlink_handle_t *handle;
1228 static inline const char *strerror(errno_t err = meshlink_errno) {
1229 return meshlink_strerror(err);
1232 /// Destroy a MeshLink instance.
1233 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
1234 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
1237 * @param confbase The directory in which MeshLink stores its configuration files.
1238 * After the function returns, the application is free to overwrite or free @a confbase @a.
1240 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
1242 static inline bool destroy(const char *confbase) {
1243 return meshlink_destroy(confbase);