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 duplicate node detection.
60 /** @param mesh A handle which represents an instance of MeshLink.
61 * @param node A pointer to a meshlink_node_t describing the node which is duplicate.
62 * This pointer is valid until meshlink_close() is called.
64 typedef void (*duplicate_cb_t)(mesh *mesh, node *node);
66 /// A callback for receiving log messages generated by MeshLink.
67 /** @param mesh A handle which represents an instance of MeshLink.
68 * @param level An enum describing the severity level of the message.
69 * @param text A pointer to a string containing the textual log message.
71 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
73 /// A callback for listening for incoming channels.
74 /** @param mesh A handle which represents an instance of MeshLink.
75 * @param node A handle for the node that wants to open a channel.
76 * @param port The port number the peer wishes to connect to.
78 * @return This function should return true if the application listens for the incoming channel, false otherwise.
80 typedef bool (*meshlink_channel_listen_cb_t)(struct meshlink_handle *mesh, struct meshlink_node *node, uint16_t port);
82 /// A callback for accepting incoming channels.
83 /** @param mesh A handle which represents an instance of MeshLink.
84 * @param channel A handle for the incoming channel.
85 * @param port The port number the peer wishes to connect to.
86 * @param data A pointer to a buffer containing data already received. (Not yet used.)
87 * @param len The length of the data. (Not yet used.)
89 * @return This function should return true if the application accepts the incoming channel, false otherwise.
90 * If returning false, the channel is invalid and may not be used anymore.
92 typedef bool (*channel_accept_cb_t)(mesh *mesh, channel *channel, uint16_t port, const void *data, size_t len);
94 /// A callback for receiving data from a channel.
95 /** @param mesh A handle which represents an instance of MeshLink.
96 * @param channel A handle for the channel.
97 * @param data A pointer to a buffer containing data sent by the source.
98 * @param len The length of the data.
100 typedef void (*channel_receive_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len);
102 /// A callback that is called when data can be send on a channel.
103 /** @param mesh A handle which represents an instance of MeshLink.
104 * @param channel A handle for the channel.
105 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
107 typedef void (*channel_poll_cb_t)(mesh *mesh, channel *channel, size_t len);
109 /// A callback for cleaning up buffers submitted for asynchronous I/O.
110 /** This callbacks signals that MeshLink has finished using this buffer.
111 * The ownership of the buffer is now back into the application's hands.
113 * @param mesh A handle which represents an instance of MeshLink.
114 * @param channel A handle for the channel which used this buffer.
115 * @param data A pointer to a buffer containing the enqueued data.
116 * @param len The length of the buffer.
117 * @param priv A private pointer which was set by the application when submitting the buffer.
119 typedef void (*aio_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len, void *priv);
121 /// A callback for asynchronous I/O to and from filedescriptors.
122 /** This callbacks signals that MeshLink has finished using this filedescriptor.
124 * @param mesh A handle which represents an instance of MeshLink.
125 * @param channel A handle for the channel which used this filedescriptor.
126 * @param fd The filedescriptor that was used.
127 * @param len The length of the data that was successfully sent or received.
128 * @param priv A private pointer which was set by the application when submitting the buffer.
130 typedef void (*aio_fd_cb_t)(mesh *mesh, channel *channel, int fd, size_t len, void *priv);
132 /// A class describing a MeshLink node.
133 class node: public meshlink_node_t {
136 /// A class describing a MeshLink channel.
137 class channel: public meshlink_channel_t {
139 static const uint32_t RELIABLE = MESHLINK_CHANNEL_RELIABLE;
140 static const uint32_t ORDERED = MESHLINK_CHANNEL_ORDERED;
141 static const uint32_t FRAMED = MESHLINK_CHANNEL_FRAMED;
142 static const uint32_t DROP_LATE = MESHLINK_CHANNEL_DROP_LATE;
143 static const uint32_t NO_PARTIAL = MESHLINK_CHANNEL_NO_PARTIAL;
144 static const uint32_t TCP = MESHLINK_CHANNEL_TCP;
145 static const uint32_t UDP = MESHLINK_CHANNEL_UDP;
148 /// A class describing a MeshLink mesh.
151 mesh() : handle(0) {}
157 bool isOpen() const {
158 return (handle != 0);
161 // TODO: please enable C++11 in autoconf to enable "move constructors":
162 // mesh(mesh&& other)
163 // : handle(other.handle)
166 // handle->priv = this;
170 /// Initialize MeshLink's configuration directory.
171 /** This function causes MeshLink to initialize its configuration directory,
172 * if it hasn't already been initialized.
173 * It only has to be run the first time the application starts,
174 * but it is not a problem if it is run more than once, as long as
175 * the arguments given are the same.
177 * This function does not start any network I/O yet. The application should
178 * first set callbacks, and then call meshlink_start().
180 * @param confbase The directory in which MeshLink will store its configuration files.
181 * @param name The name which this instance of the application will use in the mesh.
182 * @param appname The application name which will be used in the mesh.
183 * @param devclass The device class which will be used in the mesh.
185 * @return This function will return a pointer to a meshlink::mesh if MeshLink has successfully set up its configuration files, NULL otherwise.
187 bool open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
188 handle = meshlink_open(confbase, name, appname, devclass);
197 mesh(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
198 open(confbase, name, appname, devclass);
201 /// Close the MeshLink handle.
202 /** This function calls meshlink_stop() if necessary,
203 * and frees all memory allocated by MeshLink.
204 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
209 meshlink_close(handle);
215 /** instead of registerin callbacks you derive your own class and overwrite the following abstract member functions.
216 * These functions are run in MeshLink's own thread.
217 * It is therefore important that these functions use apprioriate methods (queues, pipes, locking, etc.)
218 * to hand the data over to the application's thread.
219 * These functions should also not block itself and return as quickly as possible.
220 * The default member functions are no-ops, so you are not required to overwrite all these member functions
223 /// This function is called whenever another node sends data to the local node.
224 virtual void receive(node *source, const void *data, size_t length) {
231 /// This functions is called whenever another node's status changed.
232 virtual void node_status(node *peer, bool reachable) {
238 /// This functions is called whenever a duplicate node is detected.
239 virtual void node_duplicate(node *peer) {
244 /// This functions is called whenever MeshLink has some information to log.
245 virtual void log(log_level_t level, const char *message) {
251 /// This functions is called whenever MeshLink has encountered a serious error.
252 virtual void error(meshlink_errno_t meshlink_errno) {
254 (void)meshlink_errno;
257 /// This functions is called whenever MeshLink a meta-connection attempt is made.
258 virtual void connection_try(node *peer) {
263 /// This functions is called to determine if we are listening for incoming channels.
265 * The function is run in MeshLink's own thread.
266 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
267 * to pass data to or from the application's thread.
268 * The callback should also not block itself and return as quickly as possible.
270 * @param node A handle for the node that wants to open a channel.
271 * @param port The port number the peer wishes to connect to.
273 * @return This function should return true if the application accepts the incoming channel, false otherwise.
275 virtual bool channel_listen(node *node, uint16_t port) {
276 /* by default accept all channels */
282 /// This functions is called whenever another node attempts to open a channel to the local node.
284 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
285 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
288 * The function is run in MeshLink's own thread.
289 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
290 * to pass data to or from the application's thread.
291 * The callback should also not block itself and return as quickly as possible.
293 * @param channel A handle for the incoming channel.
294 * @param port The port number the peer wishes to connect to.
295 * @param data A pointer to a buffer containing data already received. (Not yet used.)
296 * @param len The length of the data. (Not yet used.)
298 * @return This function should return true if the application accepts the incoming channel, false otherwise.
299 * If returning false, the channel is invalid and may not be used anymore.
301 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
302 /* by default reject all channels */
310 /// This function is called by Meshlink for receiving data from a channel.
312 * The function is run in MeshLink's own thread.
313 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
314 * to pass data to or from the application's thread.
315 * The callback should also not block itself and return as quickly as possible.
317 * @param channel A handle for the channel.
318 * @param data A pointer to a buffer containing data sent by the source.
319 * @param len The length of the data.
321 virtual void channel_receive(channel *channel, const void *data, size_t len) {
328 /// This function is called by Meshlink when data can be send on a channel.
330 * The function is run in MeshLink's own thread.
331 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
332 * to pass data to or from the application's thread.
334 * The callback should also not block itself and return as quickly as possible.
335 * @param channel A handle for the channel.
336 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
338 virtual void channel_poll(channel *channel, size_t len) {
345 /** This function causes MeshLink to open network sockets, make outgoing connections, and
346 * create a new thread, which will handle all network I/O.
348 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
351 meshlink_set_receive_cb(handle, &receive_trampoline);
352 meshlink_set_node_status_cb(handle, &node_status_trampoline);
353 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
354 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
355 meshlink_set_error_cb(handle, &error_trampoline);
356 meshlink_set_channel_listen_cb(handle, &channel_listen_trampoline);
357 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
358 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
359 return meshlink_start(handle);
363 /** This function causes MeshLink to disconnect from all other nodes,
364 * close all sockets, and shut down its own thread.
367 meshlink_stop(handle);
370 /// Send data to another node.
371 /** This functions sends one packet of data to another node in the mesh.
372 * The packet is sent using UDP semantics, which means that
373 * the packet is sent as one unit and is received as one unit,
374 * and that there is no guarantee that the packet will arrive at the destination.
375 * The application should take care of getting an acknowledgement and retransmission if necessary.
377 * @param destination A pointer to a meshlink::node describing the destination for the data.
378 * @param data A pointer to a buffer containing the data to be sent to the source.
379 * @param len The length of the data.
380 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
381 * A return value of true does not guarantee that the message will actually arrive at the destination.
383 bool send(node *destination, const void *data, unsigned int len) {
384 return meshlink_send(handle, destination, data, len);
387 /// Get a handle for a specific node.
388 /** This function returns a handle for the node with the given name.
390 * @param name The name of the node for which a handle is requested.
392 * @return A pointer to a meshlink::node which represents the requested node,
393 * or NULL if the requested node does not exist.
395 node *get_node(const char *name) {
396 return (node *)meshlink_get_node(handle, name);
399 /// Get a node's reachability status.
400 /** This function returns the current reachability of a given node, and the times of the last state changes.
401 * If a given state change never happened, the time returned will be 0.
403 * @param node A pointer to a meshlink::node describing the node.
404 * @param last_reachable A pointer to a time_t variable that will be filled in with the last time the node became reachable.
405 * @param last_unreachable A pointer to a time_t variable that will be filled in with the last time the node became unreachable.
407 * @return This function returns true if the node is currently reachable, false otherwise.
409 bool get_node_reachability(node *node, time_t *last_reachable = NULL, time_t *last_unreachable = NULL) {
410 return meshlink_get_node_reachability(handle, node, last_reachable, last_unreachable);
413 /// Get a handle for our own node.
414 /** This function returns a handle for the local node.
416 * @return A pointer to a meshlink::node which represents the local node.
419 return (node *)meshlink_get_self(handle);
422 /// Get a list of all nodes.
423 /** This function returns a list with handles for all known nodes.
425 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
426 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
428 * @return The number of known nodes, or -1 in case of an error.
429 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
431 node **get_all_nodes(node **nodes, size_t *nmemb) {
432 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
435 /// Sign data using the local node's MeshLink key.
436 /** This function signs data using the local node's MeshLink key.
437 * The generated signature can be securely verified by other nodes.
439 * @param data A pointer to a buffer containing the data to be signed.
440 * @param len The length of the data to be signed.
441 * @param signature A pointer to a buffer where the signature will be stored.
442 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
444 * @return This function returns true if the signature is valid, false otherwise.
446 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
447 return meshlink_sign(handle, data, len, signature, siglen);
450 /// Verify the signature generated by another node of a piece of data.
451 /** This function verifies the signature that another node generated for a piece of data.
453 * @param source A pointer to a meshlink_node_t describing the source of the signature.
454 * @param data A pointer to a buffer containing the data to be verified.
455 * @param len The length of the data to be verified.
456 * @param signature A pointer to a string containing the signature.
457 * @param siglen The size of the signature.
459 * @return This function returns true if the signature is valid, false otherwise.
461 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
462 return meshlink_verify(handle, source, data, len, signature, siglen);
465 /// Set the canonical Address for a node.
466 /** This function sets the canonical Address for a node.
467 * This address is stored permanently until it is changed by another call to this function,
468 * unlike other addresses associated with a node,
469 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
471 * If a canonical Address is set for the local node,
472 * it will be used for the hostname part of generated invitation URLs.
474 * @param node A pointer to a meshlink_node_t describing the node.
475 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
476 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
477 * If it is NULL, the listening port's number will be used.
479 * @return This function returns true if the address was added, false otherwise.
481 bool set_canonical_address(node *node, const char *address, const char *port = NULL) {
482 return meshlink_set_canonical_address(handle, node, address, port);
485 /// Clear the canonical Address for a node.
486 /** This function clears the canonical Address for a node.
488 * @param node A pointer to a struct meshlink_node describing the node.
490 * @return This function returns true if the address was removed, false otherwise.
492 bool clear_canonical_address(node *node) {
493 return meshlink_clear_canonical_address(handle, node);
496 /// Set the scheduling granularity of the application
497 /** This should be set to the effective scheduling granularity for the application.
498 * This depends on the scheduling granularity of the operating system, the application's
499 * process priority and whether it is running as realtime or not.
500 * The default value is 10000 (10 milliseconds).
502 * @param granularity The scheduling granularity of the application in microseconds.
504 void set_granularity(long granularity) {
505 meshlink_set_scheduling_granularity(handle, granularity);
508 /// Sets the storage policy used by MeshLink
509 /** This sets the policy MeshLink uses when it has new information about nodes.
510 * By default, all udpates will be stored to disk (unless an ephemeral instance has been opened).
511 * Setting the policy to MESHLINK_STORAGE_KEYS_ONLY, only updates that contain new keys for nodes
513 * By setting the policy to MESHLINK_STORAGE_DISABLED, no updates will be stored.
515 * @param policy The storage policy to use.
517 void set_storage_policy(meshlink_storage_policy_t policy) {
518 meshlink_set_storage_policy(handle, policy);
521 /// Use an invitation to join a mesh.
522 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
523 * An invitation can only be used if the local node has never connected to other nodes before.
524 * After a successfully accepted invitation, the name of the local node may have changed.
526 * 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.
528 * This function is blocking. It can take several seconds before it returns.
529 * There is no guarantee it will perform a successful join.
530 * Failures might be caused by temporary network outages, or by the invitation having expired.
532 * @param invitation A string containing the invitation URL.
534 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
536 bool join(const char *invitation) {
537 return meshlink_join(handle, invitation);
540 /// Export the local node's key and addresses.
541 /** This function generates a string that contains the local node's public key and one or more IP addresses.
542 * The application can pass it in some way to another node, which can then import it,
543 * granting the local node access to the other node's mesh.
545 * @return This function returns a string that contains the exported key and addresses.
546 * The application should call free() after it has finished using this string.
549 return meshlink_export(handle);
552 /// Import another node's key and addresses.
553 /** This function accepts a string containing the exported public key and addresses of another node.
554 * By importing this data, the local node grants the other node access to its mesh.
556 * @param data A string containing the other node's exported key and addresses.
558 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
560 bool import_key(const char *data) {
561 return meshlink_import(handle, data);
564 /// Forget any information about a node.
565 /** This function allows the local node to forget any information it has about a node,
566 * and if possible will remove any data it has stored on disk about the node.
568 * Any open channels to this node must be closed before calling this function.
570 * After this call returns, the node handle is invalid and may no longer be used, regardless
571 * of the return value of this call.
573 * Note that this function does not prevent MeshLink from actually forgetting about a node,
574 * or re-learning information about a node at a later point in time. It is merely a hint that
575 * the application does not care about this node anymore and that any resources kept could be
578 * \memberof meshlink_node
579 * @param node A pointer to a struct meshlink_node describing the node to be forgotten.
581 * @return This function returns true if all currently known data about the node has been forgotten, false otherwise.
583 bool forget_node(node *node) {
584 return meshlink_forget_node(handle, node);
587 /// Set the poll callback.
588 /** This functions sets the callback that is called whenever data can be sent to another node.
589 * The callback is run in MeshLink's own thread.
590 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
591 * to pass data to or from the application's thread.
592 * The callback should also not block itself and return as quickly as possible.
594 * @param channel A handle for the channel.
595 * @param cb A pointer to the function which will be called when data can be sent to another node.
596 * If a NULL pointer is given, the callback will be disabled.
598 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
599 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
602 /// Set the send buffer size of a channel.
603 /** This function sets the desired size of the send buffer.
604 * The default size is 128 kB.
606 * @param channel A handle for the channel.
607 * @param size The desired size for the send buffer.
608 * If a NULL pointer is given, the callback will be disabled.
610 void set_channel_sndbuf(channel *channel, size_t size) {
611 meshlink_set_channel_sndbuf(handle, channel, size);
614 /// Set the receive buffer size of a channel.
615 /** This function sets the desired size of the receive buffer.
616 * The default size is 128 kB.
618 * @param channel A handle for the channel.
619 * @param size The desired size for the send buffer.
620 * If a NULL pointer is given, the callback will be disabled.
622 void set_channel_rcvbuf(channel *channel, size_t size) {
623 meshlink_set_channel_rcvbuf(handle, channel, size);
626 /// Set the flags of a channel.
627 /** This function allows changing some of the channel flags.
628 * Currently only MESHLINK_CHANNEL_NO_PARTIAL and MESHLINK_CHANNEL_DROP_LATE are supported, other flags are ignored.
629 * These flags only affect the local side of the channel with the peer.
630 * The changes take effect immediately.
632 * @param channel A handle for the channel.
633 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
635 void set_channel_flags(channel *channel, uint32_t flags) {
636 meshlink_set_channel_flags(handle, channel, flags);
639 /// Set the send buffer storage of a channel.
640 /** This function provides MeshLink with a send buffer allocated by the application.
642 * @param channel A handle for the channel.
643 * @param buf A pointer to the start of the buffer.
644 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
645 * @param size The size of the buffer.
647 void set_channel_sndbuf_storage(channel *channel, void *buf, size_t size) {
648 meshlink_set_channel_sndbuf_storage(handle, channel, buf, size);
651 /// Set the receive buffer storage of a channel.
652 /** This function provides MeshLink with a receive buffer allocated by the application.
654 * @param channel A handle for the channel.
655 * @param buf A pointer to the start of the buffer.
656 * If a NULL pointer is given, MeshLink will use its own internal buffer again.
657 * @param size The size of the buffer.
659 void set_channel_rcvbuf_storage(channel *channel, void *buf, size_t size) {
660 meshlink_set_channel_rcvbuf_storage(handle, channel, buf, size);
663 /// Set the connection timeout used for channels to the given node.
664 /** This sets the timeout after which unresponsive channels will be reported as closed.
665 * The timeout is set for all current and future channels to the given node.
667 * @param node The node to set the channel timeout for.
668 * @param timeout The timeout in seconds after which unresponsive channels will be reported as closed.
669 * The default is 60 seconds.
671 void set_node_channel_timeout(node *node, int timeout) {
672 meshlink_set_node_channel_timeout(handle, node, timeout);
675 /// Open a reliable stream channel to another node.
676 /** This function is called whenever a remote node wants to open a channel to the local node.
677 * The application then has to decide whether to accept or reject this channel.
679 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
680 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
682 * @param node The node to which this channel is being initiated.
683 * @param port The port number the peer wishes to connect to.
684 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
685 * @param data A pointer to a buffer containing data to already queue for sending.
686 * @param len The length of the data.
687 * If len is 0, the data pointer is copied into the channel's priv member.
688 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
690 * @return A handle for the channel, or NULL in case of an error.
692 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
693 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
694 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
698 /// Open a reliable stream channel to another node.
699 /** This function is called whenever a remote node wants to open a channel to the local node.
700 * The application then has to decide whether to accept or reject this channel.
702 * This function sets the channel receive callback to channel_receive_trampoline,
703 * which in turn calls channel_receive.
705 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
706 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
708 * @param node The node to which this channel is being initiated.
709 * @param port The port number the peer wishes to connect to.
710 * @param data A pointer to a buffer containing data to already queue for sending.
711 * @param len The length of the data.
712 * If len is 0, the data pointer is copied into the channel's priv member.
713 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
715 * @return A handle for the channel, or NULL in case of an error.
717 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
718 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
719 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
723 /// Partially close a reliable stream channel.
724 /** This shuts down the read or write side of a channel, or both, without closing the handle.
725 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
726 * but still allows waiting for incoming data from the remote node.
728 * @param channel A handle for the channel.
729 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
731 void channel_shutdown(channel *channel, int direction) {
732 return meshlink_channel_shutdown(handle, channel, direction);
735 /// Close a reliable stream channel.
736 /** This informs the remote node that the local node has finished sending all data on the channel.
737 * It also causes the local node to stop accepting incoming data from the remote node.
738 * Afterwards, the channel handle is invalid and must not be used any more.
740 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
741 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
743 * @param channel A handle for the channel.
745 void channel_close(meshlink_channel_t *channel) {
746 return meshlink_channel_close(handle, channel);
749 /// Abort a reliable stream channel.
750 /** This aborts a channel.
751 * Data that was in the send and receive buffers is dropped, so potentially there is some data that
752 * was sent on this channel that will not be received by the peer.
753 * Afterwards, the channel handle is invalid and must not be used any more.
755 * It is allowed to call this function at any time on a valid handle, even inside callback functions.
756 * If called with a valid handle, this function always succeeds, otherwise the result is undefined.
758 * @param channel A handle for the channel.
760 void channel_abort(meshlink_channel_t *channel) {
761 return meshlink_channel_abort(handle, channel);
764 /// Transmit data on a channel
765 /** This queues data to send to the remote node.
767 * @param channel A handle for the channel.
768 * @param data A pointer to a buffer containing data sent by the source.
769 * @param len The length of the data.
771 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
772 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
773 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
775 ssize_t channel_send(channel *channel, void *data, size_t len) {
776 return meshlink_channel_send(handle, channel, data, len);
779 /// Transmit data on a channel asynchronously
780 /** This registers a buffer that will be used to send data to the remote node.
781 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
782 * While there are still buffers with unsent data, the poll callback will not be called.
784 * @param channel A handle for the channel.
785 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
786 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
787 * until the callback routine is called.
788 * @param len The length of the data, or 0 if there is no data to send.
789 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
790 * @param priv A private pointer which was set by the application when submitting the buffer.
792 * @return True if the buffer was enqueued, false otherwise.
794 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
795 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
798 /// Transmit data on a channel asynchronously from a filedescriptor
799 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
800 * The callback may be returned early if there is an error reading from the filedescriptor.
801 * While there is still with unsent data, the poll callback will not be called.
803 * @param channel A handle for the channel.
804 * @param fd A file descriptor from which data will be read.
805 * @param len The length of the data, or 0 if there is no data to send.
806 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
807 * @param priv A private pointer which was set by the application when submitting the buffer.
809 * @return True if the buffer was enqueued, false otherwise.
811 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
812 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
815 /// Receive data on a channel asynchronously
816 /** This registers a buffer that will be filled with incoming channel data.
817 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
818 * While there are still buffers that have not been filled, the receive callback will not be called.
820 * @param channel A handle for the channel.
821 * @param data A pointer to a buffer that will be filled with incoming data.
822 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
823 * until the callback routine is called.
824 * @param len The length of the data.
825 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
826 * @param priv A private pointer which was set by the application when submitting the buffer.
828 * @return True if the buffer was enqueued, false otherwise.
830 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
831 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
834 /// Receive data on a channel asynchronously and send it to a filedescriptor
835 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
836 * The callback may be returned early if there is an error writing to the filedescriptor.
837 * While there is still unread data, the receive callback will not be called.
839 * @param channel A handle for the channel.
840 * @param fd A file descriptor to which data will be written.
841 * @param len The length of the data.
842 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
843 * @param priv A private pointer which was set by the application when submitting the buffer.
845 * @return True if the buffer was enqueued, false otherwise.
847 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
848 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
851 /// Get the amount of bytes in the send buffer.
852 /** This returns the amount of bytes in the send buffer.
853 * These bytes have not been received by the peer yet.
855 * @param channel A handle for the channel.
857 * @return The amount of un-ACKed bytes in the send buffer.
859 size_t channel_get_sendq(channel *channel) {
860 return meshlink_channel_get_sendq(handle, channel);
863 /// Get the amount of bytes in the receive buffer.
864 /** This returns the amount of bytes in the receive buffer.
865 * These bytes have not been processed by the application yet.
867 * @param channel A handle for the channel.
869 * @return The amount of bytes in the receive buffer.
871 size_t channel_get_recvq(channel *channel) {
872 return meshlink_channel_get_recvq(handle, channel);
875 /// Get the maximum segment size of a channel.
876 /** This returns the amount of bytes that can be sent at once for channels with UDP semantics.
878 * @param channel A handle for the channel.
880 * @return The amount of bytes in the receive buffer.
882 size_t channel_get_mss(channel *channel) {
883 return meshlink_channel_get_mss(handle, channel);
886 /// Inform MeshLink that the local network configuration might have changed
887 /** This is intended to be used when there is no way for MeshLink to get notifications of local network changes.
888 * It forces MeshLink to scan all network interfaces for changes in up/down status and new/removed addresses,
889 * and will immediately check if all connections to other nodes are still alive.
891 void hint_network_change() {
892 meshlink_hint_network_change(handle);
895 /// Set device class timeouts
896 /** This sets the ping interval and timeout for a given device class.
898 * @param devclass The device class to update
899 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
900 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
901 * The timeout must be smaller than the interval.
903 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout) {
904 meshlink_set_dev_class_timeouts(handle, devclass, pinginterval, pingtimeout);
907 /// Set device class fast retry period
908 /** This sets the fast retry period for a given device class.
909 * During this period after the last time the mesh becomes unreachable, connections are tried once a second.
911 * @param devclass The device class to update
912 * @param fast_retry_period The period during which fast connection retries are done. The default is 0.
914 void set_dev_class_fast_retry_period(dev_class_t devclass, int fast_retry_period) {
915 meshlink_set_dev_class_fast_retry_period(handle, devclass, fast_retry_period);
918 /// Set device class maximum timeout
919 /** This sets the maximum timeout for outgoing connection retries for a given device class.
921 * @param devclass The device class to update
922 * @param maxtimeout The maximum timeout between reconnection attempts, in seconds. The default is 900.
924 void set_dev_class_maxtimeout(dev_class_t devclass, int maxtimeout) {
925 meshlink_set_dev_class_maxtimeout(handle, devclass, maxtimeout);
928 /// Set which order invitations are committed
929 /** This determines in which order configuration files are written to disk during an invitation.
930 * By default, the invitee saves the configuration to disk first, then the inviter.
931 * By calling this function with @a inviter_commits_first set to true, the order is reversed.
933 * @param inviter_commits_first If true, then the node that invited a peer will commit data to disk first.
935 void set_inviter_commits_first(bool inviter_commits_first) {
936 meshlink_set_inviter_commits_first(handle, inviter_commits_first);
941 mesh(const mesh &) /* TODO: C++11: = delete */;
942 void operator=(const mesh &) /* TODO: C++11: = delete */;
944 /// static callback trampolines:
945 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
946 if(!(handle->priv)) {
950 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
951 that->receive(static_cast<node *>(source), data, length);
954 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
955 if(!(handle->priv)) {
959 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
960 that->node_status(static_cast<node *>(peer), reachable);
963 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
964 if(!(handle->priv)) {
968 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
969 that->node_duplicate(static_cast<node *>(peer));
972 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
973 if(!(handle->priv)) {
977 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
978 that->log(level, message);
981 static void error_trampoline(meshlink_handle_t *handle, meshlink_errno_t meshlink_errno) {
982 if(!(handle->priv)) {
986 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
987 that->error(meshlink_errno);
990 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
991 if(!(handle->priv)) {
995 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
996 that->connection_try(static_cast<node *>(peer));
999 static bool channel_listen_trampoline(meshlink_handle_t *handle, meshlink_node_t *node, uint16_t port) {
1000 if(!(handle->priv)) {
1004 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1005 return that->channel_listen(static_cast<meshlink::node *>(node), port);
1008 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
1009 if(!(handle->priv)) {
1013 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1014 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
1017 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
1018 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
1024 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
1025 if(!(handle->priv)) {
1029 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1030 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
1033 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
1034 if(!(handle->priv)) {
1038 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
1039 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
1042 meshlink_handle_t *handle;
1045 static inline const char *strerror(errno_t err = meshlink_errno) {
1046 return meshlink_strerror(err);
1049 /// Destroy a MeshLink instance.
1050 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
1051 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
1054 * @param confbase The directory in which MeshLink stores its configuration files.
1055 * After the function returns, the application is free to overwrite or free @a confbase @a.
1057 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
1059 static inline bool destroy(const char *confbase) {
1060 return meshlink_destroy(confbase);