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 duplicate node detection.
61 /** @param mesh A handle which represents an instance of MeshLink.
62 * @param node A pointer to a meshlink_node_t describing the node which is duplicate.
63 * This pointer is valid until meshlink_close() is called.
65 typedef void (*duplicate_cb_t)(mesh *mesh, node *node);
67 /// A callback for receiving log messages generated by MeshLink.
68 /** @param mesh A handle which represents an instance of MeshLink.
69 * @param level An enum describing the severity level of the message.
70 * @param text A pointer to a string containing the textual log message.
72 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
74 /// A callback for accepting incoming channels.
75 /** @param mesh A handle which represents an instance of MeshLink.
76 * @param channel A handle for the incoming channel.
77 * @param port The port number the peer wishes to connect to.
78 * @param data A pointer to a buffer containing data already received. (Not yet used.)
79 * @param len The length of the data. (Not yet used.)
81 * @return This function should return true if the application accepts the incoming channel, false otherwise.
82 * If returning false, the channel is invalid and may not be used anymore.
84 typedef bool (*channel_accept_cb_t)(mesh *mesh, channel *channel, uint16_t port, const void *data, size_t len);
86 /// A callback for receiving data from a channel.
87 /** @param mesh A handle which represents an instance of MeshLink.
88 * @param channel A handle for the channel.
89 * @param data A pointer to a buffer containing data sent by the source.
90 * @param len The length of the data.
92 typedef void (*channel_receive_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len);
94 /// A callback that is called when data can be send on a channel.
95 /** @param mesh A handle which represents an instance of MeshLink.
96 * @param channel A handle for the channel.
97 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
99 typedef void (*channel_poll_cb_t)(mesh *mesh, channel *channel, size_t len);
101 /// A callback for cleaning up buffers submitted for asynchronous I/O.
102 /** This callbacks signals that MeshLink has finished using this buffer.
103 * The ownership of the buffer is now back into the application's hands.
105 * @param mesh A handle which represents an instance of MeshLink.
106 * @param channel A handle for the channel which used this buffer.
107 * @param data A pointer to a buffer containing the enqueued data.
108 * @param len The length of the buffer.
109 * @param priv A private pointer which was set by the application when submitting the buffer.
111 typedef void (*aio_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len, void *priv);
113 /// A callback for asynchronous I/O to and from filedescriptors.
114 /** This callbacks signals that MeshLink has finished using this filedescriptor.
116 * @param mesh A handle which represents an instance of MeshLink.
117 * @param channel A handle for the channel which used this filedescriptor.
118 * @param fd The filedescriptor that was used.
119 * @param len The length of the data that was successfully sent or received.
120 * @param priv A private pointer which was set by the application when submitting the buffer.
122 typedef void (*aio_fd_cb_t)(mesh *mesh, channel *channel, int fd, size_t len, void *priv);
124 /// A class describing a MeshLink node.
125 class node: public meshlink_node_t {
128 /// A class describing a MeshLink Sub-Mesh.
129 class submesh: public meshlink_submesh_t {
132 /// A class describing a MeshLink channel.
133 class channel: public meshlink_channel_t {
135 static const uint32_t RELIABLE = MESHLINK_CHANNEL_RELIABLE;
136 static const uint32_t ORDERED = MESHLINK_CHANNEL_ORDERED;
137 static const uint32_t FRAMED = MESHLINK_CHANNEL_FRAMED;
138 static const uint32_t DROP_LATE = MESHLINK_CHANNEL_DROP_LATE;
139 static const uint32_t NO_PARTIAL = MESHLINK_CHANNEL_NO_PARTIAL;
140 static const uint32_t TCP = MESHLINK_CHANNEL_TCP;
141 static const uint32_t UDP = MESHLINK_CHANNEL_UDP;
144 /// A class describing a MeshLink mesh.
147 mesh() : handle(0) {}
153 bool isOpen() const {
154 return (handle != 0);
157 // TODO: please enable C++11 in autoconf to enable "move constructors":
158 // mesh(mesh&& other)
159 // : handle(other.handle)
162 // handle->priv = this;
166 /// Initialize MeshLink's configuration directory.
167 /** This function causes MeshLink to initialize its configuration directory,
168 * if it hasn't already been initialized.
169 * It only has to be run the first time the application starts,
170 * but it is not a problem if it is run more than once, as long as
171 * the arguments given are the same.
173 * This function does not start any network I/O yet. The application should
174 * first set callbacks, and then call meshlink_start().
176 * @param confbase The directory in which MeshLink will store its configuration files.
177 * @param name The name which this instance of the application will use in the mesh.
178 * @param appname The application name which will be used in the mesh.
179 * @param devclass The device class which will be used in the mesh.
181 * @return This function will return a pointer to a meshlink::mesh if MeshLink has successfully set up its configuration files, NULL otherwise.
183 bool open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
184 handle = meshlink_open(confbase, name, appname, devclass);
193 mesh(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
194 open(confbase, name, appname, devclass);
197 /// Close the MeshLink handle.
198 /** This function calls meshlink_stop() if necessary,
199 * and frees all memory allocated by MeshLink.
200 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
205 meshlink_close(handle);
211 /** instead of registerin callbacks you derive your own class and overwrite the following abstract member functions.
212 * These functions are run in MeshLink's own thread.
213 * It is therefore important that these functions use apprioriate methods (queues, pipes, locking, etc.)
214 * to hand the data over to the application's thread.
215 * These functions should also not block itself and return as quickly as possible.
216 * The default member functions are no-ops, so you are not required to overwrite all these member functions
219 /// This function is called whenever another node sends data to the local node.
220 virtual void receive(node *source, const void *data, size_t length) {
227 /// This functions is called whenever another node's status changed.
228 virtual void node_status(node *peer, bool reachable) {
234 /// This functions is called whenever a duplicate node is detected.
235 virtual void node_duplicate(node *peer) {
240 /// This functions is called whenever MeshLink has some information to log.
241 virtual void log(log_level_t level, const char *message) {
247 /// This functions is called whenever MeshLink a meta-connection attempt is made.
248 virtual void connection_try(node *peer) {
253 /// This functions is called whenever another node attempts to open a channel to the local node.
255 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
256 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
259 * The function is run in MeshLink's own thread.
260 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
261 * to pass data to or from the application's thread.
262 * The callback should also not block itself and return as quickly as possible.
264 * @param channel A handle for the incoming channel.
265 * @param port The port number the peer wishes to connect to.
266 * @param data A pointer to a buffer containing data already received. (Not yet used.)
267 * @param len The length of the data. (Not yet used.)
269 * @return This function should return true if the application accepts the incoming channel, false otherwise.
270 * If returning false, the channel is invalid and may not be used anymore.
272 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
273 /* by default reject all channels */
281 /// This function is called by Meshlink for receiving data from a channel.
283 * The function is run in MeshLink's own thread.
284 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
285 * to pass data to or from the application's thread.
286 * The callback should also not block itself and return as quickly as possible.
288 * @param channel A handle for the channel.
289 * @param data A pointer to a buffer containing data sent by the source.
290 * @param len The length of the data.
292 virtual void channel_receive(channel *channel, const void *data, size_t len) {
299 /// This function is called by Meshlink when data can be send on a channel.
301 * The function is run in MeshLink's own thread.
302 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
303 * to pass data to or from the application's thread.
305 * The callback should also not block itself and return as quickly as possible.
306 * @param channel A handle for the channel.
307 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
309 virtual void channel_poll(channel *channel, size_t len) {
316 /** This function causes MeshLink to open network sockets, make outgoing connections, and
317 * create a new thread, which will handle all network I/O.
319 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
322 meshlink_set_receive_cb(handle, &receive_trampoline);
323 meshlink_set_node_status_cb(handle, &node_status_trampoline);
324 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
325 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
326 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
327 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
328 return meshlink_start(handle);
332 /** This function causes MeshLink to disconnect from all other nodes,
333 * close all sockets, and shut down its own thread.
336 meshlink_stop(handle);
339 /// Send data to another node.
340 /** This functions sends one packet of data to another node in the mesh.
341 * The packet is sent using UDP semantics, which means that
342 * the packet is sent as one unit and is received as one unit,
343 * and that there is no guarantee that the packet will arrive at the destination.
344 * The application should take care of getting an acknowledgement and retransmission if necessary.
346 * @param destination A pointer to a meshlink::node describing the destination for the data.
347 * @param data A pointer to a buffer containing the data to be sent to the source.
348 * @param len The length of the data.
349 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
350 * A return value of true does not guarantee that the message will actually arrive at the destination.
352 bool send(node *destination, const void *data, unsigned int len) {
353 return meshlink_send(handle, destination, data, len);
356 /// Get a handle for a specific node.
357 /** This function returns a handle for the node with the given name.
359 * @param name The name of the node for which a handle is requested.
361 * @return A pointer to a meshlink::node which represents the requested node,
362 * or NULL if the requested node does not exist.
364 node *get_node(const char *name) {
365 return (node *)meshlink_get_node(handle, name);
368 /// Get a handle for a specific submesh.
369 /** This function returns a handle for the submesh with the given name.
371 * @param name The name of the submesh for which a handle is requested.
373 * @return A pointer to a meshlink::submesh which represents the requested submesh,
374 * or NULL if the requested submesh does not exist.
376 submesh *get_submesh(const char *name) {
377 return (submesh *)meshlink_get_submesh(handle, name);
380 /// Get a handle for our own node.
381 /** This function returns a handle for the local node.
383 * @return A pointer to a meshlink::node which represents the local node.
386 return (node *)meshlink_get_self(handle);
389 /// Get a list of all nodes.
390 /** This function returns a list with handles for all known nodes.
392 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
393 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
395 * @return The number of known nodes, or -1 in case of an error.
396 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
398 node **get_all_nodes(node **nodes, size_t *nmemb) {
399 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
402 /// Sign data using the local node's MeshLink key.
403 /** This function signs data using the local node's MeshLink key.
404 * The generated signature can be securely verified by other nodes.
406 * @param data A pointer to a buffer containing the data to be signed.
407 * @param len The length of the data to be signed.
408 * @param signature A pointer to a buffer where the signature will be stored.
409 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
411 * @return This function returns true if the signature is valid, false otherwise.
413 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
414 return meshlink_sign(handle, data, len, signature, siglen);
417 /// Verify the signature generated by another node of a piece of data.
418 /** This function verifies the signature that another node generated for a piece of data.
420 * @param source A pointer to a meshlink_node_t describing the source of the signature.
421 * @param data A pointer to a buffer containing the data to be verified.
422 * @param len The length of the data to be verified.
423 * @param signature A pointer to a string containing the signature.
424 * @param siglen The size of the signature.
426 * @return This function returns true if the signature is valid, false otherwise.
428 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
429 return meshlink_verify(handle, source, data, len, signature, siglen);
432 /// Set the canonical Address for a node.
433 /** This function sets the canonical Address for a node.
434 * This address is stored permanently until it is changed by another call to this function,
435 * unlike other addresses associated with a node,
436 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
438 * If a canonical Address is set for the local node,
439 * it will be used for the hostname part of generated invitation URLs.
441 * @param node A pointer to a meshlink_node_t describing the node.
442 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
443 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
444 * If it is NULL, the listening port's number will be used.
446 * @return This function returns true if the address was added, false otherwise.
448 bool set_canonical_address(node *node, const char *address, const char *port = NULL) {
449 return meshlink_set_canonical_address(handle, node, address, port);
452 /// Set the canonical Address for the local node.
453 /** This function sets the canonical Address for the local node.
454 * This address is stored permanently until it is changed by another call to this function,
455 * unlike other addresses associated with a node,
456 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
458 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
459 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
460 * If it is NULL, the listening port's number will be used.
462 * @return This function returns true if the address was added, false otherwise.
464 bool set_canonical_address(const char *address, const char *port = NULL) {
465 return meshlink_set_canonical_address(handle, get_self(), address, port);
468 /// Add an Address for the local node.
469 /** This function adds an Address for the local node, which will be used for invitation URLs.
471 * @param address A string containing the address, which can be either in numeric format or a hostname.
473 * @return This function returns true if the address was added, false otherwise.
475 bool add_address(const char *address) {
476 return meshlink_add_address(handle, address);
479 /** This function performs tries to discover the local node's external address
480 * by contacting the meshlink.io server. If a reverse lookup of the address works,
481 * the FQDN associated with the address will be returned.
483 * Please note that this is function only returns a single address,
484 * even if the local node might have more than one external address.
485 * In that case, there is no control over which address will be selected.
486 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
487 * there is no guarantee that the external address will be valid for an extended period of time.
489 * This function is blocking. It can take several seconds before it returns.
490 * There is no guarantee it will be able to resolve the external address.
491 * Failures might be because by temporary network outages.
493 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
494 * this might return the external address for any working address family.
496 * @return This function returns a pointer to a C string containing the discovered external address,
497 * or NULL if there was an error looking up the address.
498 * After get_external_address() returns, the application is free to overwrite or free this string.
500 bool get_external_address(int family = AF_UNSPEC) {
501 return meshlink_get_external_address_for_family(handle, family);
504 /** This function performs tries to discover the address of the local interface used for outgoing connection.
506 * Please note that this is function only returns a single address,
507 * even if the local node might have more than one external address.
508 * In that case, there is no control over which address will be selected.
509 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
510 * there is no guarantee that the external address will be valid for an extended period of time.
512 * This function will fail if it couldn't find a local address for the given address family.
513 * If hostname resolving is requested, this function may block for a few seconds.
515 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
516 * this might return the external address for any working address family.
518 * @return This function returns a pointer to a C string containing the discovered external address,
519 * or NULL if there was an error looking up the address.
520 * After get_external_address() returns, the application is free to overwrite or free this string.
522 bool get_local_address(int family = AF_UNSPEC) {
523 return meshlink_get_local_address_for_family(handle, family);
526 /// Try to discover the external address for the local node, and add it to its list of addresses.
527 /** This function is equivalent to:
529 * mesh->add_address(mesh->get_external_address());
531 * Read the description of get_external_address() for the limitations of this function.
533 * @return This function returns true if the address was added, false otherwise.
535 bool add_external_address() {
536 return meshlink_add_external_address(handle);
539 /// Get the network port used by the local node.
540 /** This function returns the network port that the local node is listening on.
542 * @return This function returns the port number, or -1 in case of an error.
545 return meshlink_get_port(handle);
548 /// Set the network port used by the local node.
549 /** This function sets the network port that the local node is listening on.
550 * It may only be called when the mesh is not running.
551 * If unsure, call stop() before calling this function.
552 * Also note that if your node is already part of a mesh with other nodes,
553 * that the other nodes may no longer be able to initiate connections to the local node,
554 * since they will try to connect to the previously configured port.
556 * @param port The port number to listen on. This must be between 0 and 65535.
557 * If the port is set to 0, then MeshLink will listen on a port
558 * that is randomly assigned by the operating system every time open() is called.
560 * @return This function returns true if the port was successfully changed
561 * to the desired port, false otherwise. If it returns false, there
562 * is no guarantee that MeshLink is listening on the old port.
564 bool set_port(int port) {
565 return meshlink_set_port(handle, port);
568 /// Set the timeout for invitations.
569 /** This function sets the timeout for invitations.
570 * The timeout is retroactively applied to all outstanding invitations.
572 * @param timeout The timeout for invitations in seconds.
574 void set_invitation_timeout(int timeout) {
575 meshlink_set_invitation_timeout(handle, timeout);
578 /// Invite another node into the mesh.
579 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
580 * The generated invitation is a string containing a URL.
581 * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
582 * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
584 * @param submesh A handle to the submesh to put the invitee in.
585 * @param name The name that the invitee will use in the mesh.
586 * @param flags A bitwise-or'd combination of flags that controls how the URL is generated.
588 * @return This function returns a string that contains the invitation URL.
589 * The application should call free() after it has finished using the URL.
591 char *invite(submesh *submesh, const char *name, uint32_t flags = 0) {
592 return meshlink_invite_ex(handle, submesh, name, flags);
595 /// Use an invitation to join a mesh.
596 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
597 * An invitation can only be used if the local node has never connected to other nodes before.
598 * After a successfully accepted invitation, the name of the local node may have changed.
600 * 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.
602 * This function is blocking. It can take several seconds before it returns.
603 * There is no guarantee it will perform a successful join.
604 * Failures might be caused by temporary network outages, or by the invitation having expired.
606 * @param invitation A string containing the invitation URL.
608 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
610 bool join(const char *invitation) {
611 return meshlink_join(handle, invitation);
614 /// Export the local node's key and addresses.
615 /** This function generates a string that contains the local node's public key and one or more IP addresses.
616 * The application can pass it in some way to another node, which can then import it,
617 * granting the local node access to the other node's mesh.
619 * @return This function returns a string that contains the exported key and addresses.
620 * The application should call free() after it has finished using this string.
623 return meshlink_export(handle);
626 /// Import another node's key and addresses.
627 /** This function accepts a string containing the exported public key and addresses of another node.
628 * By importing this data, the local node grants the other node access to its mesh.
630 * @param data A string containing the other node's exported key and addresses.
632 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
634 bool import_key(const char *data) {
635 return meshlink_import(handle, data);
638 /// Blacklist a node from the mesh.
639 /** This function causes the local node to blacklist another node.
640 * The local node will drop any existing connections to that node,
641 * and will not send data to it nor accept any data received from it any more.
643 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
645 void blacklist(node *node) {
646 return meshlink_blacklist(handle, node);
649 /// Set the poll callback.
650 /** This functions sets the callback that is called whenever data can be sent to another node.
651 * The callback is run in MeshLink's own thread.
652 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
653 * to pass data to or from the application's thread.
654 * The callback should also not block itself and return as quickly as possible.
656 * @param channel A handle for the channel.
657 * @param cb A pointer to the function which will be called when data can be sent to another node.
658 * If a NULL pointer is given, the callback will be disabled.
660 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
661 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
664 /// Set the send buffer size of a channel.
665 /** This function sets the desired size of the send buffer.
666 * The default size is 128 kB.
668 * @param channel A handle for the channel.
669 * @param size The desired size for the send buffer.
670 * If a NULL pointer is given, the callback will be disabled.
672 void set_channel_sndbuf(channel *channel, size_t size) {
673 meshlink_set_channel_sndbuf(handle, channel, size);
676 /// Set the receive buffer size of a channel.
677 /** This function sets the desired size of the receive buffer.
678 * The default size is 128 kB.
680 * @param channel A handle for the channel.
681 * @param size The desired size for the send buffer.
682 * If a NULL pointer is given, the callback will be disabled.
684 void set_channel_rcvbuf(channel *channel, size_t size) {
685 meshlink_set_channel_rcvbuf(handle, channel, size);
688 /// Open a reliable stream channel to another node.
689 /** This function is called whenever a remote node wants to open a channel to the local node.
690 * The application then has to decide whether to accept or reject this channel.
692 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
693 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
695 * @param node The node to which this channel is being initiated.
696 * @param port The port number the peer wishes to connect to.
697 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
698 * @param data A pointer to a buffer containing data to already queue for sending.
699 * @param len The length of the data.
700 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
702 * @return A handle for the channel, or NULL in case of an error.
704 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
705 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
706 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
710 /// Open a reliable stream channel to another node.
711 /** This function is called whenever a remote node wants to open a channel to the local node.
712 * The application then has to decide whether to accept or reject this channel.
714 * This function sets the channel receive callback to channel_receive_trampoline,
715 * which in turn calls channel_receive.
717 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
718 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
720 * @param node The node to which this channel is being initiated.
721 * @param port The port number the peer wishes to connect to.
722 * @param data A pointer to a buffer containing data to already queue for sending.
723 * @param len The length of the data.
724 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
726 * @return A handle for the channel, or NULL in case of an error.
728 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
729 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
730 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
734 /// Partially close a reliable stream channel.
735 /** This shuts down the read or write side of a channel, or both, without closing the handle.
736 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
737 * but still allows waiting for incoming data from the remote node.
739 * @param channel A handle for the channel.
740 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
742 void channel_shutdown(channel *channel, int direction) {
743 return meshlink_channel_shutdown(handle, channel, direction);
746 /// Close a reliable stream channel.
747 /** This informs the remote node that the local node has finished sending all data on the channel.
748 * It also causes the local node to stop accepting incoming data from the remote node.
749 * Afterwards, the channel handle is invalid and must not be used any more.
751 * @param channel A handle for the channel.
753 void channel_close(meshlink_channel_t *channel) {
754 return meshlink_channel_close(handle, channel);
757 /// Transmit data on a channel
758 /** This queues data to send to the remote node.
760 * @param channel A handle for the channel.
761 * @param data A pointer to a buffer containing data sent by the source.
762 * @param len The length of the data.
764 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
765 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
766 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
768 ssize_t channel_send(channel *channel, void *data, size_t len) {
769 return meshlink_channel_send(handle, channel, data, len);
772 /// Transmit data on a channel asynchronously
773 /** This registers a buffer that will be used to send data to the remote node.
774 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
775 * While there are still buffers with unsent data, the poll callback will not be called.
777 * @param channel A handle for the channel.
778 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
779 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
780 * until the callback routine is called.
781 * @param len The length of the data, or 0 if there is no data to send.
782 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
784 * @return True if the buffer was enqueued, false otherwise.
786 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
787 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
790 /// Transmit data on a channel asynchronously from a filedescriptor
791 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
792 * The callback may be returned early if there is an error reading from the filedescriptor.
793 * While there is still with unsent data, the poll callback will not be called.
795 * @param channel A handle for the channel.
796 * @param fd A file descriptor from which data will be read.
797 * @param len The length of the data, or 0 if there is no data to send.
798 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
800 * @return True if the buffer was enqueued, false otherwise.
802 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
803 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
806 /// Receive data on a channel asynchronously
807 /** This registers a buffer that will be filled with incoming channel data.
808 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
809 * While there are still buffers that have not been filled, the receive callback will not be called.
811 * @param channel A handle for the channel.
812 * @param data A pointer to a buffer that will be filled with incoming data.
813 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
814 * until the callback routine is called.
815 * @param len The length of the data.
816 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
818 * @return True if the buffer was enqueued, false otherwise.
820 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
821 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
824 /// Receive data on a channel asynchronously and send it to a filedescriptor
825 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
826 * The callback may be returned early if there is an error writing to the filedescriptor.
827 * While there is still unread data, the receive callback will not be called.
829 * @param channel A handle for the channel.
830 * @param fd A file descriptor to which data will be written.
831 * @param len The length of the data.
832 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
834 * @return True if the buffer was enqueued, false otherwise.
836 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
837 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
840 /// Get the amount of bytes in the send buffer.
841 /** This returns the amount of bytes in the send buffer.
842 * These bytes have not been received by the peer yet.
844 * @param channel A handle for the channel.
846 * @return The amount of un-ACKed bytes in the send buffer.
848 size_t channel_get_sendq(channel *channel) {
849 return meshlink_channel_get_sendq(handle, channel);
852 /// Get the amount of bytes in the receive buffer.
853 /** This returns the amount of bytes in the receive buffer.
854 * These bytes have not been processed by the application yet.
856 * @param channel A handle for the channel.
858 * @return The amount of bytes in the receive buffer.
860 size_t channel_get_recvq(channel *channel) {
861 return meshlink_channel_get_recvq(handle, channel);
864 /// Enable or disable zeroconf discovery of local peers
865 /** This controls whether zeroconf discovery using the Catta library will be
866 * enabled to search for peers on the local network. By default, it is enabled.
868 * @param enable Set to true to enable discovery, false to disable.
870 void enable_discovery(bool enable = true) {
871 meshlink_enable_discovery(handle, enable);
874 /// Set device class timeouts
875 /** This sets the ping interval and timeout for a given device class.
877 * @param devclass The device class to update
878 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
879 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
880 * The timeout must be smaller than the interval.
882 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout);
886 mesh(const mesh &) /* TODO: C++11: = delete */;
887 void operator=(const mesh &) /* TODO: C++11: = delete */;
889 /// static callback trampolines:
890 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
891 if(!(handle->priv)) {
895 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
896 that->receive(static_cast<node *>(source), data, length);
899 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
900 if(!(handle->priv)) {
904 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
905 that->node_status(static_cast<node *>(peer), reachable);
908 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
909 if(!(handle->priv)) {
913 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
914 that->node_duplicate(static_cast<node *>(peer));
917 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
918 if(!(handle->priv)) {
922 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
923 that->log(level, message);
926 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
927 if(!(handle->priv)) {
931 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
932 that->connection_try(static_cast<node *>(peer));
935 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
936 if(!(handle->priv)) {
940 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
941 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
944 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
945 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
951 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
952 if(!(handle->priv)) {
956 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
957 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
960 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
961 if(!(handle->priv)) {
965 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
966 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
969 meshlink_handle_t *handle;
972 static inline const char *strerror(errno_t err = meshlink_errno) {
973 return meshlink_strerror(err);
976 /// Destroy a MeshLink instance.
977 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
978 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
981 * @param confbase The directory in which MeshLink stores its configuration files.
982 * After the function returns, the application is free to overwrite or free @a confbase @a.
984 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
986 static inline bool destroy(const char *confbase) {
987 return meshlink_destroy(confbase);