5 meshlink-tiny++.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.
23 #include <meshlink-tiny.h>
24 #include <new> // for 'placement new'
31 /// Severity of log messages generated by MeshLink.
32 typedef meshlink_log_level_t log_level_t;
34 /// Code of most recent error encountered.
35 typedef meshlink_errno_t errno_t;
37 /// A callback for receiving data from the mesh.
38 /** @param mesh A handle which represents an instance of MeshLink.
39 * @param source A pointer to a meshlink::node describing the source of the data.
40 * @param data A pointer to a buffer containing the data sent by the source.
41 * @param len The length of the received data.
43 typedef void (*receive_cb_t)(mesh *mesh, node *source, const void *data, size_t len);
45 /// A callback reporting the meta-connection attempt made by the host node to an another node.
46 /** @param mesh A handle which represents an instance of MeshLink.
47 * @param node A pointer to a meshlink_node_t describing the node to whom meta-connection is being tried.
48 * This pointer is valid until meshlink_close() is called.
50 typedef void (*connection_try_cb_t)(mesh *mesh, node *node);
52 /// A callback reporting node status changes.
53 /** @param mesh A handle which represents an instance of MeshLink.
54 * @param node A pointer to a meshlink::node describing the node whose status changed.
55 * @param reachable True if the node is reachable, false otherwise.
57 typedef void (*node_status_cb_t)(mesh *mesh, node *node, bool reachable);
59 /// A callback reporting node path MTU changes.
60 /** @param mesh A handle which represents an instance of MeshLink.
61 * @param node A pointer to a meshlink_node_t describing the node whose status changed.
62 * This pointer is valid until meshlink_close() is called.
63 * @param pmtu The current path MTU to the node, or 0 if UDP communication is not (yet) possible.
65 typedef void (*node_pmtu_cb_t)(mesh *mesh, node *node, uint16_t pmtu);
67 /// A callback reporting duplicate node detection.
68 /** @param mesh A handle which represents an instance of MeshLink.
69 * @param node A pointer to a meshlink_node_t describing the node which is duplicate.
70 * This pointer is valid until meshlink_close() is called.
72 typedef void (*duplicate_cb_t)(mesh *mesh, node *node);
74 /// A callback for receiving log messages generated by MeshLink.
75 /** @param mesh A handle which represents an instance of MeshLink.
76 * @param level An enum describing the severity level of the message.
77 * @param text A pointer to a string containing the textual log message.
79 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
81 /// A callback for listening for incoming channels.
82 /** @param mesh A handle which represents an instance of MeshLink.
83 * @param node A handle for the node that wants to open a channel.
84 * @param port The port number the peer wishes to connect to.
86 * @return This function should return true if the application listens for the incoming channel, false otherwise.
88 typedef bool (*meshlink_channel_listen_cb_t)(struct meshlink_handle *mesh, struct meshlink_node *node, uint16_t port);
90 /// A callback for accepting incoming channels.
91 /** @param mesh A handle which represents an instance of MeshLink.
92 * @param channel A handle for the incoming channel.
93 * @param port The port number the peer wishes to connect to.
94 * @param data A pointer to a buffer containing data already received. (Not yet used.)
95 * @param len The length of the data. (Not yet used.)
97 * @return This function should return true if the application accepts the incoming channel, false otherwise.
98 * If returning false, the channel is invalid and may not be used anymore.
100 typedef bool (*channel_accept_cb_t)(mesh *mesh, channel *channel, uint16_t port, const void *data, size_t len);
102 /// A callback for receiving data from a channel.
103 /** @param mesh A handle which represents an instance of MeshLink.
104 * @param channel A handle for the channel.
105 * @param data A pointer to a buffer containing data sent by the source.
106 * @param len The length of the data.
108 typedef void (*channel_receive_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len);
110 /// A callback that is called when data can be send on a channel.
111 /** @param mesh A handle which represents an instance of MeshLink.
112 * @param channel A handle for the channel.
113 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
115 typedef void (*channel_poll_cb_t)(mesh *mesh, channel *channel, size_t len);
117 /// A callback for cleaning up buffers submitted for asynchronous I/O.
118 /** This callbacks signals that MeshLink has finished using this buffer.
119 * The ownership of the buffer is now back into the application's hands.
121 * @param mesh A handle which represents an instance of MeshLink.
122 * @param channel A handle for the channel which used this buffer.
123 * @param data A pointer to a buffer containing the enqueued data.
124 * @param len The length of the buffer.
125 * @param priv A private pointer which was set by the application when submitting the buffer.
127 typedef void (*aio_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len, void *priv);
129 /// A callback for asynchronous I/O to and from filedescriptors.
130 /** This callbacks signals that MeshLink has finished using this filedescriptor.
132 * @param mesh A handle which represents an instance of MeshLink.
133 * @param channel A handle for the channel which used this filedescriptor.
134 * @param fd The filedescriptor that was used.
135 * @param len The length of the data that was successfully sent or received.
136 * @param priv A private pointer which was set by the application when submitting the buffer.
138 typedef void (*aio_fd_cb_t)(mesh *mesh, channel *channel, int fd, size_t len, void *priv);
140 /// A class describing a MeshLink node.
141 class node: public meshlink_node_t {
144 /// A class describing a MeshLink channel.
145 class channel: public meshlink_channel_t {
147 static const uint32_t RELIABLE = MESHLINK_CHANNEL_RELIABLE;
148 static const uint32_t ORDERED = MESHLINK_CHANNEL_ORDERED;
149 static const uint32_t FRAMED = MESHLINK_CHANNEL_FRAMED;
150 static const uint32_t DROP_LATE = MESHLINK_CHANNEL_DROP_LATE;
151 static const uint32_t NO_PARTIAL = MESHLINK_CHANNEL_NO_PARTIAL;
152 static const uint32_t TCP = MESHLINK_CHANNEL_TCP;
153 static const uint32_t UDP = MESHLINK_CHANNEL_UDP;
156 /// A class describing a MeshLink mesh.
159 mesh() : handle(0) {}
165 bool isOpen() const {
166 return (handle != 0);
169 // TODO: please enable C++11 in autoconf to enable "move constructors":
170 // mesh(mesh&& other)
171 // : handle(other.handle)
174 // handle->priv = this;
178 /// Initialize MeshLink's configuration directory.
179 /** This function causes MeshLink to initialize its configuration directory,
180 * if it hasn't already been initialized.
181 * It only has to be run the first time the application starts,
182 * but it is not a problem if it is run more than once, as long as
183 * the arguments given are the same.
185 * This function does not start any network I/O yet. The application should
186 * first set callbacks, and then call meshlink_start().
188 * @param confbase The directory in which MeshLink will store its configuration files.
189 * @param name The name which this instance of the application will use in the mesh.
190 * @param appname The application name which will be used in the mesh.
191 * @param devclass The device class which will be used in the mesh.
193 * @return This function will return a pointer to a meshlink::mesh if MeshLink has successfully set up its configuration files, NULL otherwise.
195 bool open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
196 handle = meshlink_open(confbase, name, appname, devclass);
205 mesh(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
206 open(confbase, name, appname, devclass);
209 /// Close the MeshLink handle.
210 /** This function calls meshlink_stop() if necessary,
211 * and frees all memory allocated by MeshLink.
212 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
217 meshlink_close(handle);
223 /** instead of registerin callbacks you derive your own class and overwrite the following abstract member functions.
224 * These functions are run in MeshLink's own thread.
225 * It is therefore important that these functions use apprioriate methods (queues, pipes, locking, etc.)
226 * to hand the data over to the application's thread.
227 * These functions should also not block itself and return as quickly as possible.
228 * The default member functions are no-ops, so you are not required to overwrite all these member functions
231 /// This function is called whenever another node sends data to the local node.
232 virtual void receive(node *source, const void *data, size_t length) {
239 /// This functions is called whenever another node's status changed.
240 virtual void node_status(node *peer, bool reachable) {
246 /// This functions is called whenever another node's path MTU changes.
247 virtual void node_pmtu(node *peer, uint16_t pmtu) {
253 /// This functions is called whenever a duplicate node is detected.
254 virtual void node_duplicate(node *peer) {
259 /// This functions is called whenever MeshLink has some information to log.
260 virtual void log(log_level_t level, const char *message) {
266 /// This functions is called whenever MeshLink has encountered a serious error.
267 virtual void error(meshlink_errno_t meshlink_errno) {
269 (void)meshlink_errno;
272 /// This functions is called whenever MeshLink a meta-connection attempt is made.
273 virtual void connection_try(node *peer) {
278 /// This functions is called to determine if we are listening for incoming channels.
280 * The function is run in MeshLink's own thread.
281 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
282 * to pass data to or from the application's thread.
283 * The callback should also not block itself and return as quickly as possible.
285 * @param node A handle for the node that wants to open a channel.
286 * @param port The port number the peer wishes to connect to.
288 * @return This function should return true if the application accepts the incoming channel, false otherwise.
290 virtual bool channel_listen(node *node, uint16_t port) {
291 /* by default accept all channels */
297 /// This functions is called whenever another node attempts to open a channel to the local node.
299 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
300 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
303 * The function is run in MeshLink's own thread.
304 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
305 * to pass data to or from the application's thread.
306 * The callback should also not block itself and return as quickly as possible.
308 * @param channel A handle for the incoming channel.
309 * @param port The port number the peer wishes to connect to.
310 * @param data A pointer to a buffer containing data already received. (Not yet used.)
311 * @param len The length of the data. (Not yet used.)
313 * @return This function should return true if the application accepts the incoming channel, false otherwise.
314 * If returning false, the channel is invalid and may not be used anymore.
316 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
317 /* by default reject all channels */
325 /// This function is called by Meshlink for receiving data from a channel.
327 * The function is run in MeshLink's own thread.
328 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
329 * to pass data to or from the application's thread.
330 * The callback should also not block itself and return as quickly as possible.
332 * @param channel A handle for the channel.
333 * @param data A pointer to a buffer containing data sent by the source.
334 * @param len The length of the data.
336 virtual void channel_receive(channel *channel, const void *data, size_t len) {
343 /// This function is called by Meshlink when data can be send on a channel.
345 * The function is run in MeshLink's own thread.
346 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
347 * to pass data to or from the application's thread.
349 * The callback should also not block itself and return as quickly as possible.
350 * @param channel A handle for the channel.
351 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
353 virtual void channel_poll(channel *channel, size_t len) {
360 /** This function causes MeshLink to open network sockets, make outgoing connections, and
361 * create a new thread, which will handle all network I/O.
363 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
366 meshlink_set_receive_cb(handle, &receive_trampoline);
367 meshlink_set_node_status_cb(handle, &node_status_trampoline);
368 meshlink_set_node_pmtu_cb(handle, &node_pmtu_trampoline);
369 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
370 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
371 meshlink_set_error_cb(handle, &error_trampoline);
372 meshlink_set_channel_listen_cb(handle, &channel_listen_trampoline);
373 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
374 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
375 return meshlink_start(handle);
379 /** This function causes MeshLink to disconnect from all other nodes,
380 * close all sockets, and shut down its own thread.
383 meshlink_stop(handle);
386 /// Send data to another node.
387 /** This functions sends one packet of data to another node in the mesh.
388 * The packet is sent using UDP semantics, which means that
389 * the packet is sent as one unit and is received as one unit,
390 * and that there is no guarantee that the packet will arrive at the destination.
391 * The application should take care of getting an acknowledgement and retransmission if necessary.
393 * @param destination A pointer to a meshlink::node describing the destination for the data.
394 * @param data A pointer to a buffer containing the data to be sent to the source.
395 * @param len The length of the data.
396 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
397 * A return value of true does not guarantee that the message will actually arrive at the destination.
399 bool send(node *destination, const void *data, unsigned int len) {
400 return meshlink_send(handle, destination, data, len);
403 /// Get a handle for a specific node.
404 /** This function returns a handle for the node with the given name.
406 * @param name The name of the node for which a handle is requested.
408 * @return A pointer to a meshlink::node which represents the requested node,
409 * or NULL if the requested node does not exist.
411 node *get_node(const char *name) {
412 return (node *)meshlink_get_node(handle, name);
415 /// Get a node's reachability status.
416 /** This function returns the current reachability of a given node, and the times of the last state changes.
417 * If a given state change never happened, the time returned will be 0.
419 * @param node A pointer to a meshlink::node describing the node.
420 * @param last_reachable A pointer to a time_t variable that will be filled in with the last time the node became reachable.
421 * @param last_unreachable A pointer to a time_t variable that will be filled in with the last time the node became unreachable.
423 * @return This function returns true if the node is currently reachable, false otherwise.
425 bool get_node_reachability(node *node, time_t *last_reachable = NULL, time_t *last_unreachable = NULL) {
426 return meshlink_get_node_reachability(handle, node, last_reachable, last_unreachable);
429 /// Get a handle for our own node.
430 /** This function returns a handle for the local node.
432 * @return A pointer to a meshlink::node which represents the local node.
435 return (node *)meshlink_get_self(handle);
438 /// Get a list of all nodes.
439 /** This function returns a list with handles for all known nodes.
441 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
442 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
444 * @return The number of known nodes, or -1 in case of an error.
445 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
447 node **get_all_nodes(node **nodes, size_t *nmemb) {
448 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
451 /// Sign data using the local node's MeshLink key.
452 /** This function signs data using the local node's MeshLink key.
453 * The generated signature can be securely verified by other nodes.
455 * @param data A pointer to a buffer containing the data to be signed.
456 * @param len The length of the data to be signed.
457 * @param signature A pointer to a buffer where the signature will be stored.
458 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
460 * @return This function returns true if the signature is valid, false otherwise.
462 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
463 return meshlink_sign(handle, data, len, signature, siglen);
466 /// Verify the signature generated by another node of a piece of data.
467 /** This function verifies the signature that another node generated for a piece of data.
469 * @param source A pointer to a meshlink_node_t describing the source of the signature.
470 * @param data A pointer to a buffer containing the data to be verified.
471 * @param len The length of the data to be verified.
472 * @param signature A pointer to a string containing the signature.
473 * @param siglen The size of the signature.
475 * @return This function returns true if the signature is valid, false otherwise.
477 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
478 return meshlink_verify(handle, source, data, len, signature, siglen);
481 /// Set the canonical Address for a node.
482 /** This function sets the canonical Address for a node.
483 * This address is stored permanently until it is changed by another call to this function,
484 * unlike other addresses associated with a node,
485 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
487 * If a canonical Address is set for the local node,
488 * it will be used for the hostname part of generated invitation URLs.
490 * @param node A pointer to a meshlink_node_t describing the node.
491 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
492 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
493 * If it is NULL, the listening port's number will be used.
495 * @return This function returns true if the address was added, false otherwise.
497 bool set_canonical_address(node *node, const char *address, const char *port = NULL) {
498 return meshlink_set_canonical_address(handle, node, address, port);
501 /// Clear the canonical Address for a node.
502 /** This function clears the canonical Address for a node.
504 * @param node A pointer to a struct meshlink_node describing the node.
506 * @return This function returns true if the address was removed, false otherwise.
508 bool clear_canonical_address(node *node) {
509 return meshlink_clear_canonical_address(handle, node);
512 /// Set the scheduling granularity of the application
513 /** This should be set to the effective scheduling granularity for the application.
514 * This depends on the scheduling granularity of the operating system, the application's
515 * process priority and whether it is running as realtime or not.
516 * The default value is 10000 (10 milliseconds).
518 * @param granularity The scheduling granularity of the application in microseconds.
520 void set_granularity(long granularity) {
521 meshlink_set_scheduling_granularity(handle, granularity);
524 /// Sets the storage policy used by MeshLink
525 /** This sets the policy MeshLink uses when it has new information about nodes.
526 * By default, all udpates will be stored to disk (unless an ephemeral instance has been opened).
527 * Setting the policy to MESHLINK_STORAGE_KEYS_ONLY, only updates that contain new keys for nodes
529 * By setting the policy to MESHLINK_STORAGE_DISABLED, no updates will be stored.
531 * @param policy The storage policy to use.
533 void set_storage_policy(meshlink_storage_policy_t policy) {
534 meshlink_set_storage_policy(handle, policy);
537 /// Use an invitation to join a mesh.
538 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
539 * An invitation can only be used if the local node has never connected to other nodes before.
540 * After a successfully accepted invitation, the name of the local node may have changed.
542 * 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.
544 * This function is blocking. It can take several seconds before it returns.
545 * There is no guarantee it will perform a successful join.
546 * Failures might be caused by temporary network outages, or by the invitation having expired.
548 * @param invitation A string containing the invitation URL.
550 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
552 bool join(const char *invitation) {
553 return meshlink_join(handle, invitation);
556 /// Export the local node's key and addresses.
557 /** This function generates a string that contains the local node's public key and one or more IP addresses.
558 * The application can pass it in some way to another node, which can then import it,
559 * granting the local node access to the other node's mesh.
561 * @return This function returns a string that contains the exported key and addresses.
562 * The application should call free() after it has finished using this string.
565 return meshlink_export(handle);
568 /// Import another node's key and addresses.
569 /** This function accepts a string containing the exported public key and addresses of another node.
570 * By importing this data, the local node grants the other node access to its mesh.
572 * @param data A string containing the other node's exported key and addresses.
574 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
576 bool import_key(const char *data) {
577 return meshlink_import(handle, data);
580 /// Forget any information about a node.
581 /** This function allows the local node to forget any information it has about a node,
582 * and if possible will remove any data it has stored on disk about the node.
584 * Any open channels to this node must be closed before calling this function.
586 * After this call returns, the node handle is invalid and may no longer be used, regardless
587 * of the return value of this call.
589 * Note that this function does not prevent MeshLink from actually forgetting about a node,
590 * or re-learning information about a node at a later point in time. It is merely a hint that
591 * the application does not care about this node anymore and that any resources kept could be
594 * \memberof meshlink_node
595 * @param node A pointer to a struct meshlink_node describing the node to be forgotten.
597 * @return This function returns true if all currently known data about the node has been forgotten, false otherwise.
599 bool forget_node(node *node) {
600 return meshlink_forget_node(handle, node);
603 /// Set the poll callback.
604 /** This functions sets the callback that is called whenever data can be sent to another node.
605 * The callback is run in MeshLink's own thread.
606 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
607 * to pass data to or from the application's thread.
608 * The callback should also not block itself and return as quickly as possible.
610 * @param channel A handle for the channel.
611 * @param cb A pointer to the function which will be called when data can be sent to another node.
612 * If a NULL pointer is given, the callback will be disabled.
614 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
615 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
618 /// Set the send buffer size of a channel.
619 /** This function sets the desired size of the send buffer.
620 * The default size is 128 kB.
622 * @param channel A handle for the channel.
623 * @param size The desired size for the send buffer.
624 * If a NULL pointer is given, the callback will be disabled.
626 void set_channel_sndbuf(channel *channel, size_t size) {
627 meshlink_set_channel_sndbuf(handle, channel, size);
630 /// Set the receive buffer size of a channel.
631 /** This function sets the desired size of the receive buffer.
632 * The default size is 128 kB.
634 * @param channel A handle for the channel.
635 * @param size The desired size for the send buffer.
636 * If a NULL pointer is given, the callback will be disabled.
638 void set_channel_rcvbuf(channel *channel, size_t size) {
639 meshlink_set_channel_rcvbuf(handle, channel, size);
642 /// Set the flags of a channel.
643 /** This function allows changing some of the channel flags.
644 * Currently only MESHLINK_CHANNEL_NO_PARTIAL and MESHLINK_CHANNEL_DROP_LATE are supported, other flags are ignored.
645 * These flags only affect the local side of the channel with the peer.
646 * The changes take effect immediately.
648 * @param channel A handle for the channel.
649 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
651 void set_channel_flags(channel *channel, uint32_t flags) {
652 meshlink_set_channel_flags(handle, channel, flags);
655 /// Set the send buffer storage of a channel.
656 /** This function provides MeshLink with a send buffer allocated by the application.
658 * @param channel A handle for the channel.
659 * @param buf A pointer to the start of the buffer.
660 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
661 * @param size The size of the buffer.
663 void set_channel_sndbuf_storage(channel *channel, void *buf, size_t size) {
664 meshlink_set_channel_sndbuf_storage(handle, channel, buf, size);
667 /// Set the receive buffer storage of a channel.
668 /** This function provides MeshLink with a receive buffer allocated by the application.
670 * @param channel A handle for the channel.
671 * @param buf A pointer to the start of the buffer.
672 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
673 * @param size The size of the buffer.
675 void set_channel_rcvbuf_storage(channel *channel, void *buf, size_t size) {
676 meshlink_set_channel_rcvbuf_storage(handle, channel, buf, size);
679 /// Set the connection timeout used for channels to the given node.
680 /** This sets the timeout after which unresponsive channels will be reported as closed.
681 * The timeout is set for all current and future channels to the given node.
683 * @param node The node to set the channel timeout for.
684 * @param timeout The timeout in seconds after which unresponsive channels will be reported as closed.
685 * The default is 60 seconds.
687 void set_node_channel_timeout(node *node, int timeout) {
688 meshlink_set_node_channel_timeout(handle, node, timeout);
691 /// Open a reliable stream channel to another node.
692 /** This function is called whenever a remote node wants to open a channel to the local node.
693 * The application then has to decide whether to accept or reject this channel.
695 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
696 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
698 * @param node The node to which this channel is being initiated.
699 * @param port The port number the peer wishes to connect to.
700 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
701 * @param data A pointer to a buffer containing data to already queue for sending.
702 * @param len The length of the data.
703 * If len is 0, the data pointer is copied into the channel's priv member.
704 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
706 * @return A handle for the channel, or NULL in case of an error.
708 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
709 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
710 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
714 /// Open a reliable stream channel to another node.
715 /** This function is called whenever a remote node wants to open a channel to the local node.
716 * The application then has to decide whether to accept or reject this channel.
718 * This function sets the channel receive callback to channel_receive_trampoline,
719 * which in turn calls channel_receive.
721 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
722 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
724 * @param node The node to which this channel is being initiated.
725 * @param port The port number the peer wishes to connect to.
726 * @param data A pointer to a buffer containing data to already queue for sending.
727 * @param len The length of the data.
728 * If len is 0, the data pointer is copied into the channel's priv member.
729 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
731 * @return A handle for the channel, or NULL in case of an error.
733 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
734 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
735 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
739 /// Partially close a reliable stream channel.
740 /** This shuts down the read or write side of a channel, or both, without closing the handle.
741 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
742 * but still allows waiting for incoming data from the remote node.
744 * @param channel A handle for the channel.
745 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
747 void channel_shutdown(channel *channel, int direction) {
748 return meshlink_channel_shutdown(handle, channel, direction);
751 /// Close a reliable stream channel.
752 /** This informs the remote node that the local node has finished sending all data on the channel.
753 * It also causes the local node to stop accepting incoming data from the remote node.
754 * Afterwards, the channel handle is invalid and must not be used any more.
756 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
757 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
759 * @param channel A handle for the channel.
761 void channel_close(meshlink_channel_t *channel) {
762 return meshlink_channel_close(handle, channel);
765 /// Abort a reliable stream channel.
766 /** This aborts a channel.
767 * Data that was in the send and receive buffers is dropped, so potentially there is some data that
768 * was sent on this channel that will not be received by the peer.
769 * Afterwards, the channel handle is invalid and must not be used any more.
771 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
772 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
774 * @param channel A handle for the channel.
776 void channel_abort(meshlink_channel_t *channel) {
777 return meshlink_channel_abort(handle, channel);
780 /// Transmit data on a channel
781 /** This queues data to send to the remote node.
783 * @param channel A handle for the channel.
784 * @param data A pointer to a buffer containing data sent by the source.
785 * @param len The length of the data.
787 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
788 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
789 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
791 ssize_t channel_send(channel *channel, void *data, size_t len) {
792 return meshlink_channel_send(handle, channel, data, len);
795 /// Transmit data on a channel asynchronously
796 /** This registers a buffer that will be used to send data to the remote node.
797 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
798 * While there are still buffers with unsent data, the poll callback will not be called.
800 * @param channel A handle for the channel.
801 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
802 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
803 * until the callback routine is called.
804 * @param len The length of the data, or 0 if there is no data to send.
805 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
806 * @param priv A private pointer which was set by the application when submitting the buffer.
808 * @return True if the buffer was enqueued, false otherwise.
810 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
811 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
814 /// Transmit data on a channel asynchronously from a filedescriptor
815 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
816 * The callback may be returned early if there is an error reading from the filedescriptor.
817 * While there is still with unsent data, the poll callback will not be called.
819 * @param channel A handle for the channel.
820 * @param fd A file descriptor from which data will be read.
821 * @param len The length of the data, or 0 if there is no data to send.
822 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
823 * @param priv A private pointer which was set by the application when submitting the buffer.
825 * @return True if the buffer was enqueued, false otherwise.
827 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
828 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
831 /// Receive data on a channel asynchronously
832 /** This registers a buffer that will be filled with incoming channel data.
833 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
834 * While there are still buffers that have not been filled, the receive callback will not be called.
836 * @param channel A handle for the channel.
837 * @param data A pointer to a buffer that will be filled with incoming data.
838 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
839 * until the callback routine is called.
840 * @param len The length of the data.
841 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
842 * @param priv A private pointer which was set by the application when submitting the buffer.
844 * @return True if the buffer was enqueued, false otherwise.
846 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
847 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
850 /// Receive data on a channel asynchronously and send it to a filedescriptor
851 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
852 * The callback may be returned early if there is an error writing to the filedescriptor.
853 * While there is still unread data, the receive callback will not be called.
855 * @param channel A handle for the channel.
856 * @param fd A file descriptor to which data will be written.
857 * @param len The length of the data.
858 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
859 * @param priv A private pointer which was set by the application when submitting the buffer.
861 * @return True if the buffer was enqueued, false otherwise.
863 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
864 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
867 /// Get the amount of bytes in the send buffer.
868 /** This returns the amount of bytes in the send buffer.
869 * These bytes have not been received by the peer yet.
871 * @param channel A handle for the channel.
873 * @return The amount of un-ACKed bytes in the send buffer.
875 size_t channel_get_sendq(channel *channel) {
876 return meshlink_channel_get_sendq(handle, channel);
879 /// Get the amount of bytes in the receive buffer.
880 /** This returns the amount of bytes in the receive buffer.
881 * These bytes have not been processed by the application yet.
883 * @param channel A handle for the channel.
885 * @return The amount of bytes in the receive buffer.
887 size_t channel_get_recvq(channel *channel) {
888 return meshlink_channel_get_recvq(handle, channel);
891 /// Get the maximum segment size of a channel.
892 /** This returns the amount of bytes that can be sent at once for channels with UDP semantics.
894 * @param channel A handle for the channel.
896 * @return The amount of bytes in the receive buffer.
898 size_t channel_get_mss(channel *channel) {
899 return meshlink_channel_get_mss(handle, channel);
902 /// Inform MeshLink that the local network configuration might have changed
903 /** This is intended to be used when there is no way for MeshLink to get notifications of local network changes.
904 * It forces MeshLink to scan all network interfaces for changes in up/down status and new/removed addresses,
905 * and will immediately check if all connections to other nodes are still alive.
907 void hint_network_change() {
908 meshlink_hint_network_change(handle);
911 /// Set device class timeouts
912 /** This sets the ping interval and timeout for a given device class.
914 * @param devclass The device class to update
915 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
916 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
917 * The timeout must be smaller than the interval.
919 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout) {
920 meshlink_set_dev_class_timeouts(handle, devclass, pinginterval, pingtimeout);
923 /// Set device class fast retry period
924 /** This sets the fast retry period for a given device class.
925 * During this period after the last time the mesh becomes unreachable, connections are tried once a second.
927 * @param devclass The device class to update
928 * @param fast_retry_period The period during which fast connection retries are done. The default is 0.
930 void set_dev_class_fast_retry_period(dev_class_t devclass, int fast_retry_period) {
931 meshlink_set_dev_class_fast_retry_period(handle, devclass, fast_retry_period);
934 /// Set device class maximum timeout
935 /** This sets the maximum timeout for outgoing connection retries for a given device class.
937 * @param devclass The device class to update
938 * @param maxtimeout The maximum timeout between reconnection attempts, in seconds. The default is 900.
940 void set_dev_class_maxtimeout(dev_class_t devclass, int maxtimeout) {
941 meshlink_set_dev_class_maxtimeout(handle, devclass, maxtimeout);
944 /// Set which order invitations are committed
945 /** This determines in which order configuration files are written to disk during an invitation.
946 * By default, the invitee saves the configuration to disk first, then the inviter.
947 * By calling this function with @a inviter_commits_first set to true, the order is reversed.
949 * @param inviter_commits_first If true, then the node that invited a peer will commit data to disk first.
951 void set_inviter_commits_first(bool inviter_commits_first) {
952 meshlink_set_inviter_commits_first(handle, inviter_commits_first);
957 mesh(const mesh &) /* TODO: C++11: = delete */;
958 void operator=(const mesh &) /* TODO: C++11: = delete */;
960 /// static callback trampolines:
961 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
962 if(!(handle->priv)) {
966 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
967 that->receive(static_cast<node *>(source), data, length);
970 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
971 if(!(handle->priv)) {
975 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
976 that->node_status(static_cast<node *>(peer), reachable);
979 static void node_pmtu_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, uint16_t pmtu) {
980 if(!(handle->priv)) {
984 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
985 that->node_pmtu(static_cast<node *>(peer), pmtu);
988 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
989 if(!(handle->priv)) {
993 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
994 that->node_duplicate(static_cast<node *>(peer));
997 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
998 if(!(handle->priv)) {
1002 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1003 that->log(level, message);
1006 static void error_trampoline(meshlink_handle_t *handle, meshlink_errno_t meshlink_errno) {
1007 if(!(handle->priv)) {
1011 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1012 that->error(meshlink_errno);
1015 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
1016 if(!(handle->priv)) {
1020 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1021 that->connection_try(static_cast<node *>(peer));
1024 static bool channel_listen_trampoline(meshlink_handle_t *handle, meshlink_node_t *node, uint16_t port) {
1025 if(!(handle->priv)) {
1029 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1030 return that->channel_listen(static_cast<meshlink::node *>(node), port);
1033 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
1034 if(!(handle->priv)) {
1038 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1039 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
1042 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
1043 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
1049 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
1050 if(!(handle->priv)) {
1054 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1055 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
1058 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
1059 if(!(handle->priv)) {
1063 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1064 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
1067 meshlink_handle_t *handle;
1070 static inline const char *strerror(errno_t err = meshlink_errno) {
1071 return meshlink_strerror(err);
1074 /// Destroy a MeshLink instance.
1075 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
1076 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
1079 * @param confbase The directory in which MeshLink stores its configuration files.
1080 * After the function returns, the application is free to overwrite or free @a confbase @a.
1082 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
1084 static inline bool destroy(const char *confbase) {
1085 return meshlink_destroy(confbase);