5 meshlink++.h -- MeshLink C++ API
6 Copyright (C) 2014, 2017 Guus Sliepen <guus@meshlink.io>
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 2 of the License, or
11 (at your option) any later version.
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License along
19 with this program; if not, write to the Free Software Foundation, Inc.,
20 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 #include <new> // for 'placement new'
32 /// Severity of log messages generated by MeshLink.
33 typedef meshlink_log_level_t log_level_t;
35 /// Code of most recent error encountered.
36 typedef meshlink_errno_t errno_t;
38 /// A callback for receiving data from the mesh.
39 /** @param mesh A handle which represents an instance of MeshLink.
40 * @param source A pointer to a meshlink::node describing the source of the data.
41 * @param data A pointer to a buffer containing the data sent by the source.
42 * @param len The length of the received data.
44 typedef void (*receive_cb_t)(mesh *mesh, node *source, const void *data, size_t len);
46 /// A callback reporting the meta-connection attempt made by the host node to an another node.
47 /** @param mesh A handle which represents an instance of MeshLink.
48 * @param node A pointer to a meshlink_node_t describing the node to whom meta-connection is being tried.
49 * This pointer is valid until meshlink_close() is called.
51 typedef void (*connection_try_cb_t)(mesh *mesh, node *node);
53 /// A callback reporting node status changes.
54 /** @param mesh A handle which represents an instance of MeshLink.
55 * @param node A pointer to a meshlink::node describing the node whose status changed.
56 * @param reachable True if the node is reachable, false otherwise.
58 typedef void (*node_status_cb_t)(mesh *mesh, node *node, bool reachable);
60 /// A callback reporting node path MTU changes.
61 /** @param mesh A handle which represents an instance of MeshLink.
62 * @param node A pointer to a meshlink_node_t describing the node whose status changed.
63 * This pointer is valid until meshlink_close() is called.
64 * @param pmtu The current path MTU to the node, or 0 if UDP communication is not (yet) possible.
66 typedef void (*node_pmtu_cb_t)(mesh *mesh, node *node, uint16_t pmtu);
68 /// A callback reporting duplicate node detection.
69 /** @param mesh A handle which represents an instance of MeshLink.
70 * @param node A pointer to a meshlink_node_t describing the node which is duplicate.
71 * This pointer is valid until meshlink_close() is called.
73 typedef void (*duplicate_cb_t)(mesh *mesh, node *node);
75 /// A callback for receiving log messages generated by MeshLink.
76 /** @param mesh A handle which represents an instance of MeshLink.
77 * @param level An enum describing the severity level of the message.
78 * @param text A pointer to a string containing the textual log message.
80 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
82 /// A callback for 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 Sub-Mesh.
137 class submesh: public meshlink_submesh_t {
140 /// A class describing a MeshLink channel.
141 class channel: public meshlink_channel_t {
143 static const uint32_t RELIABLE = MESHLINK_CHANNEL_RELIABLE;
144 static const uint32_t ORDERED = MESHLINK_CHANNEL_ORDERED;
145 static const uint32_t FRAMED = MESHLINK_CHANNEL_FRAMED;
146 static const uint32_t DROP_LATE = MESHLINK_CHANNEL_DROP_LATE;
147 static const uint32_t NO_PARTIAL = MESHLINK_CHANNEL_NO_PARTIAL;
148 static const uint32_t TCP = MESHLINK_CHANNEL_TCP;
149 static const uint32_t UDP = MESHLINK_CHANNEL_UDP;
152 /// A class describing a MeshLink mesh.
155 mesh() : handle(0) {}
161 bool isOpen() const {
162 return (handle != 0);
165 // TODO: please enable C++11 in autoconf to enable "move constructors":
166 // mesh(mesh&& other)
167 // : handle(other.handle)
170 // handle->priv = this;
174 /// Initialize MeshLink's configuration directory.
175 /** This function causes MeshLink to initialize its configuration directory,
176 * if it hasn't already been initialized.
177 * It only has to be run the first time the application starts,
178 * but it is not a problem if it is run more than once, as long as
179 * the arguments given are the same.
181 * This function does not start any network I/O yet. The application should
182 * first set callbacks, and then call meshlink_start().
184 * @param confbase The directory in which MeshLink will store its configuration files.
185 * @param name The name which this instance of the application will use in the mesh.
186 * @param appname The application name which will be used in the mesh.
187 * @param devclass The device class which will be used in the mesh.
189 * @return This function will return a pointer to a meshlink::mesh if MeshLink has successfully set up its configuration files, NULL otherwise.
191 bool open(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
192 handle = meshlink_open(confbase, name, appname, devclass);
201 mesh(const char *confbase, const char *name, const char *appname, dev_class_t devclass) {
202 open(confbase, name, appname, devclass);
205 /// Close the MeshLink handle.
206 /** This function calls meshlink_stop() if necessary,
207 * and frees all memory allocated by MeshLink.
208 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
213 meshlink_close(handle);
219 /** instead of registerin callbacks you derive your own class and overwrite the following abstract member functions.
220 * These functions are run in MeshLink's own thread.
221 * It is therefore important that these functions use apprioriate methods (queues, pipes, locking, etc.)
222 * to hand the data over to the application's thread.
223 * These functions should also not block itself and return as quickly as possible.
224 * The default member functions are no-ops, so you are not required to overwrite all these member functions
227 /// This function is called whenever another node sends data to the local node.
228 virtual void receive(node *source, const void *data, size_t length) {
235 /// This functions is called whenever another node's status changed.
236 virtual void node_status(node *peer, bool reachable) {
242 /// This functions is called whenever another node's path MTU changes.
243 virtual void node_pmtu(node *peer, uint16_t pmtu) {
249 /// This functions is called whenever a duplicate node is detected.
250 virtual void node_duplicate(node *peer) {
255 /// This functions is called whenever MeshLink has some information to log.
256 virtual void log(log_level_t level, const char *message) {
262 /// This functions is called whenever MeshLink a meta-connection attempt is made.
263 virtual void connection_try(node *peer) {
268 /// This functions is called whenever another node attempts to open a channel to the local node.
270 * If the channel is accepted, the poll_callback will be set to channel_poll and can be
271 * changed using set_channel_poll_cb(). Likewise, the receive callback is set to
274 * The function is run in MeshLink's own thread.
275 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
276 * to pass data to or from the application's thread.
277 * The callback should also not block itself and return as quickly as possible.
279 * @param channel A handle for the incoming channel.
280 * @param port The port number the peer wishes to connect to.
281 * @param data A pointer to a buffer containing data already received. (Not yet used.)
282 * @param len The length of the data. (Not yet used.)
284 * @return This function should return true if the application accepts the incoming channel, false otherwise.
285 * If returning false, the channel is invalid and may not be used anymore.
287 virtual bool channel_accept(channel *channel, uint16_t port, const void *data, size_t len) {
288 /* by default reject all channels */
296 /// This function is called by Meshlink for receiving data from a channel.
298 * The function is run in MeshLink's own thread.
299 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
300 * to pass data to or from the application's thread.
301 * The callback should also not block itself and return as quickly as possible.
303 * @param channel A handle for the channel.
304 * @param data A pointer to a buffer containing data sent by the source.
305 * @param len The length of the data.
307 virtual void channel_receive(channel *channel, const void *data, size_t len) {
314 /// This function is called by Meshlink when data can be send on a channel.
316 * The function is run in MeshLink's own thread.
317 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
318 * to pass data to or from the application's thread.
320 * The callback should also not block itself and return as quickly as possible.
321 * @param channel A handle for the channel.
322 * @param len The maximum length of data that is guaranteed to be accepted by a call to channel_send().
324 virtual void channel_poll(channel *channel, size_t len) {
331 /** This function causes MeshLink to open network sockets, make outgoing connections, and
332 * create a new thread, which will handle all network I/O.
334 * @return This function will return true if MeshLink has successfully started its thread, false otherwise.
337 meshlink_set_receive_cb(handle, &receive_trampoline);
338 meshlink_set_node_status_cb(handle, &node_status_trampoline);
339 meshlink_set_node_pmtu_cb(handle, &node_pmtu_trampoline);
340 meshlink_set_node_duplicate_cb(handle, &node_duplicate_trampoline);
341 meshlink_set_log_cb(handle, MESHLINK_DEBUG, &log_trampoline);
342 meshlink_set_channel_accept_cb(handle, &channel_accept_trampoline);
343 meshlink_set_connection_try_cb(handle, &connection_try_trampoline);
344 return meshlink_start(handle);
348 /** This function causes MeshLink to disconnect from all other nodes,
349 * close all sockets, and shut down its own thread.
352 meshlink_stop(handle);
355 /// Send data to another node.
356 /** This functions sends one packet of data to another node in the mesh.
357 * The packet is sent using UDP semantics, which means that
358 * the packet is sent as one unit and is received as one unit,
359 * and that there is no guarantee that the packet will arrive at the destination.
360 * The application should take care of getting an acknowledgement and retransmission if necessary.
362 * @param destination A pointer to a meshlink::node describing the destination for the data.
363 * @param data A pointer to a buffer containing the data to be sent to the source.
364 * @param len The length of the data.
365 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
366 * A return value of true does not guarantee that the message will actually arrive at the destination.
368 bool send(node *destination, const void *data, unsigned int len) {
369 return meshlink_send(handle, destination, data, len);
372 /// Get a handle for a specific node.
373 /** This function returns a handle for the node with the given name.
375 * @param name The name of the node for which a handle is requested.
377 * @return A pointer to a meshlink::node which represents the requested node,
378 * or NULL if the requested node does not exist.
380 node *get_node(const char *name) {
381 return (node *)meshlink_get_node(handle, name);
384 /// Get a handle for a specific submesh.
385 /** This function returns a handle for the submesh with the given name.
387 * @param name The name of the submesh for which a handle is requested.
389 * @return A pointer to a meshlink::submesh which represents the requested submesh,
390 * or NULL if the requested submesh does not exist.
392 submesh *get_submesh(const char *name) {
393 return (submesh *)meshlink_get_submesh(handle, name);
396 /// Get a handle for our own node.
397 /** This function returns a handle for the local node.
399 * @return A pointer to a meshlink::node which represents the local node.
402 return (node *)meshlink_get_self(handle);
405 /// Get a list of all nodes.
406 /** This function returns a list with handles for all known nodes.
408 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
409 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
411 * @return The number of known nodes, or -1 in case of an error.
412 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
414 node **get_all_nodes(node **nodes, size_t *nmemb) {
415 return (node **)meshlink_get_all_nodes(handle, (meshlink_node_t **)nodes, nmemb);
418 /// Sign data using the local node's MeshLink key.
419 /** This function signs data using the local node's MeshLink key.
420 * The generated signature can be securely verified by other nodes.
422 * @param data A pointer to a buffer containing the data to be signed.
423 * @param len The length of the data to be signed.
424 * @param signature A pointer to a buffer where the signature will be stored.
425 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
427 * @return This function returns true if the signature is valid, false otherwise.
429 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
430 return meshlink_sign(handle, data, len, signature, siglen);
433 /// Verify the signature generated by another node of a piece of data.
434 /** This function verifies the signature that another node generated for a piece of data.
436 * @param source A pointer to a meshlink_node_t describing the source of the signature.
437 * @param data A pointer to a buffer containing the data to be verified.
438 * @param len The length of the data to be verified.
439 * @param signature A pointer to a string containing the signature.
440 * @param siglen The size of the signature.
442 * @return This function returns true if the signature is valid, false otherwise.
444 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
445 return meshlink_verify(handle, source, data, len, signature, siglen);
448 /// Set the canonical Address for a node.
449 /** This function sets the canonical Address for a node.
450 * This address is stored permanently until it is changed by another call to this function,
451 * unlike other addresses associated with a node,
452 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
454 * If a canonical Address is set for the local node,
455 * it will be used for the hostname part of generated invitation URLs.
457 * @param node A pointer to a meshlink_node_t describing the node.
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(node *node, const char *address, const char *port = NULL) {
465 return meshlink_set_canonical_address(handle, node, address, port);
468 /// Set the canonical Address for the local node.
469 /** This function sets the canonical Address for the local node.
470 * This address is stored permanently until it is changed by another call to this function,
471 * unlike other addresses associated with a node,
472 * such as those added with meshlink_hint_address() or addresses discovered at runtime.
474 * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
475 * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
476 * If it is NULL, the listening port's number will be used.
478 * @return This function returns true if the address was added, false otherwise.
480 bool set_canonical_address(const char *address, const char *port = NULL) {
481 return meshlink_set_canonical_address(handle, get_self(), address, port);
484 /// Add an Address for the local node.
485 /** This function adds an Address for the local node, which will be used for invitation URLs.
487 * @param address A string containing the address, which can be either in numeric format or a hostname.
489 * @return This function returns true if the address was added, false otherwise.
491 bool add_address(const char *address) {
492 return meshlink_add_address(handle, address);
495 /** This function performs tries to discover the local node's external address
496 * by contacting the meshlink.io server. If a reverse lookup of the address works,
497 * the FQDN associated with the address will be returned.
499 * Please note that this is function only returns a single address,
500 * even if the local node might have more than one external address.
501 * In that case, there is no control over which address will be selected.
502 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
503 * there is no guarantee that the external address will be valid for an extended period of time.
505 * This function is blocking. It can take several seconds before it returns.
506 * There is no guarantee it will be able to resolve the external address.
507 * Failures might be because by temporary network outages.
509 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
510 * this might return the external address for any working address family.
512 * @return This function returns a pointer to a C string containing the discovered external address,
513 * or NULL if there was an error looking up the address.
514 * After get_external_address() returns, the application is free to overwrite or free this string.
516 bool get_external_address(int family = AF_UNSPEC) {
517 return meshlink_get_external_address_for_family(handle, family);
520 /** This function performs tries to discover the address of the local interface used for outgoing connection.
522 * Please note that this is function only returns a single address,
523 * even if the local node might have more than one external address.
524 * In that case, there is no control over which address will be selected.
525 * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
526 * there is no guarantee that the external address will be valid for an extended period of time.
528 * This function will fail if it couldn't find a local address for the given address family.
529 * If hostname resolving is requested, this function may block for a few seconds.
531 * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
532 * this might return the external address for any working address family.
534 * @return This function returns a pointer to a C string containing the discovered external address,
535 * or NULL if there was an error looking up the address.
536 * After get_external_address() returns, the application is free to overwrite or free this string.
538 bool get_local_address(int family = AF_UNSPEC) {
539 return meshlink_get_local_address_for_family(handle, family);
542 /// Try to discover the external address for the local node, and add it to its list of addresses.
543 /** This function is equivalent to:
545 * mesh->add_address(mesh->get_external_address());
547 * Read the description of get_external_address() for the limitations of this function.
549 * @return This function returns true if the address was added, false otherwise.
551 bool add_external_address() {
552 return meshlink_add_external_address(handle);
555 /// Get the network port used by the local node.
556 /** This function returns the network port that the local node is listening on.
558 * @return This function returns the port number, or -1 in case of an error.
561 return meshlink_get_port(handle);
564 /// Set the network port used by the local node.
565 /** This function sets the network port that the local node is listening on.
566 * It may only be called when the mesh is not running.
567 * If unsure, call stop() before calling this function.
568 * Also note that if your node is already part of a mesh with other nodes,
569 * that the other nodes may no longer be able to initiate connections to the local node,
570 * since they will try to connect to the previously configured port.
572 * @param port The port number to listen on. This must be between 0 and 65535.
573 * If the port is set to 0, then MeshLink will listen on a port
574 * that is randomly assigned by the operating system every time open() is called.
576 * @return This function returns true if the port was successfully changed
577 * to the desired port, false otherwise. If it returns false, there
578 * is no guarantee that MeshLink is listening on the old port.
580 bool set_port(int port) {
581 return meshlink_set_port(handle, port);
584 /// Set the timeout for invitations.
585 /** This function sets the timeout for invitations.
586 * The timeout is retroactively applied to all outstanding invitations.
588 * @param timeout The timeout for invitations in seconds.
590 void set_invitation_timeout(int timeout) {
591 meshlink_set_invitation_timeout(handle, timeout);
594 /// Invite another node into the mesh.
595 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
596 * The generated invitation is a string containing a URL.
597 * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
598 * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
600 * @param submesh A handle to the submesh to put the invitee in.
601 * @param name The name that the invitee will use in the mesh.
602 * @param flags A bitwise-or'd combination of flags that controls how the URL is generated.
604 * @return This function returns a string that contains the invitation URL.
605 * The application should call free() after it has finished using the URL.
607 char *invite(submesh *submesh, const char *name, uint32_t flags = 0) {
608 return meshlink_invite_ex(handle, submesh, name, flags);
611 /// Use an invitation to join a mesh.
612 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
613 * An invitation can only be used if the local node has never connected to other nodes before.
614 * After a successfully accepted invitation, the name of the local node may have changed.
616 * 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.
618 * This function is blocking. It can take several seconds before it returns.
619 * There is no guarantee it will perform a successful join.
620 * Failures might be caused by temporary network outages, or by the invitation having expired.
622 * @param invitation A string containing the invitation URL.
624 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
626 bool join(const char *invitation) {
627 return meshlink_join(handle, invitation);
630 /// Export the local node's key and addresses.
631 /** This function generates a string that contains the local node's public key and one or more IP addresses.
632 * The application can pass it in some way to another node, which can then import it,
633 * granting the local node access to the other node's mesh.
635 * @return This function returns a string that contains the exported key and addresses.
636 * The application should call free() after it has finished using this string.
639 return meshlink_export(handle);
642 /// Import another node's key and addresses.
643 /** This function accepts a string containing the exported public key and addresses of another node.
644 * By importing this data, the local node grants the other node access to its mesh.
646 * @param data A string containing the other node's exported key and addresses.
648 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
650 bool import_key(const char *data) {
651 return meshlink_import(handle, data);
654 /// Blacklist a node from the mesh.
655 /** This function causes the local node to blacklist another node.
656 * The local node will drop any existing connections to that node,
657 * and will not send data to it nor accept any data received from it any more.
659 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
661 void blacklist(node *node) {
662 return meshlink_blacklist(handle, node);
665 /// Set the poll callback.
666 /** This functions sets the callback that is called whenever data can be sent to another node.
667 * The callback is run in MeshLink's own thread.
668 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
669 * to pass data to or from the application's thread.
670 * The callback should also not block itself and return as quickly as possible.
672 * @param channel A handle for the channel.
673 * @param cb A pointer to the function which will be called when data can be sent to another node.
674 * If a NULL pointer is given, the callback will be disabled.
676 void set_channel_poll_cb(channel *channel, channel_poll_cb_t cb) {
677 meshlink_set_channel_poll_cb(handle, channel, (meshlink_channel_poll_cb_t)cb);
680 /// Set the send buffer size of a channel.
681 /** This function sets the desired size of the send buffer.
682 * The default size is 128 kB.
684 * @param channel A handle for the channel.
685 * @param size The desired size for the send buffer.
686 * If a NULL pointer is given, the callback will be disabled.
688 void set_channel_sndbuf(channel *channel, size_t size) {
689 meshlink_set_channel_sndbuf(handle, channel, size);
692 /// Set the receive buffer size of a channel.
693 /** This function sets the desired size of the receive buffer.
694 * The default size is 128 kB.
696 * @param channel A handle for the channel.
697 * @param size The desired size for the send buffer.
698 * If a NULL pointer is given, the callback will be disabled.
700 void set_channel_rcvbuf(channel *channel, size_t size) {
701 meshlink_set_channel_rcvbuf(handle, channel, size);
704 /// Open a reliable stream channel to another node.
705 /** This function is called whenever a remote node wants to open a channel to the local node.
706 * The application then has to decide whether to accept or reject this channel.
708 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
709 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
711 * @param node The node to which this channel is being initiated.
712 * @param port The port number the peer wishes to connect to.
713 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
714 * @param data A pointer to a buffer containing data to already queue for sending.
715 * @param len The length of the data.
716 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
718 * @return A handle for the channel, or NULL in case of an error.
720 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags = channel::TCP) {
721 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, (meshlink_channel_receive_cb_t)cb, data, len, flags);
722 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
726 /// Open a reliable stream channel to another node.
727 /** This function is called whenever a remote node wants to open a channel to the local node.
728 * The application then has to decide whether to accept or reject this channel.
730 * This function sets the channel receive callback to channel_receive_trampoline,
731 * which in turn calls channel_receive.
733 * This function sets the channel poll callback to channel_poll_trampoline, which in turn
734 * calls channel_poll. To set a different, channel-specific poll callback, use set_channel_poll_cb.
736 * @param node The node to which this channel is being initiated.
737 * @param port The port number the peer wishes to connect to.
738 * @param data A pointer to a buffer containing data to already queue for sending.
739 * @param len The length of the data.
740 * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
742 * @return A handle for the channel, or NULL in case of an error.
744 channel *channel_open(node *node, uint16_t port, const void *data, size_t len, uint32_t flags = channel::TCP) {
745 channel *ch = (channel *)meshlink_channel_open_ex(handle, node, port, &channel_receive_trampoline, data, len, flags);
746 meshlink_set_channel_poll_cb(handle, ch, &channel_poll_trampoline);
750 /// Partially close a reliable stream channel.
751 /** This shuts down the read or write side of a channel, or both, without closing the handle.
752 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
753 * but still allows waiting for incoming data from the remote node.
755 * @param channel A handle for the channel.
756 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
758 void channel_shutdown(channel *channel, int direction) {
759 return meshlink_channel_shutdown(handle, channel, direction);
762 /// Close a reliable stream channel.
763 /** This informs the remote node that the local node has finished sending all data on the channel.
764 * It also causes the local node to stop accepting incoming data from the remote node.
765 * Afterwards, the channel handle is invalid and must not be used any more.
767 * @param channel A handle for the channel.
769 void channel_close(meshlink_channel_t *channel) {
770 return meshlink_channel_close(handle, channel);
773 /// Transmit data on a channel
774 /** This queues data to send to the remote node.
776 * @param channel A handle for the channel.
777 * @param data A pointer to a buffer containing data sent by the source.
778 * @param len The length of the data.
780 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
781 * If MESHLINK_CHANNEL_NO_PARTIAL is set, then the result will either be len,
782 * 0 if the buffer is currently too full, or -1 if len is too big even for an empty buffer.
784 ssize_t channel_send(channel *channel, void *data, size_t len) {
785 return meshlink_channel_send(handle, channel, data, len);
788 /// Transmit data on a channel asynchronously
789 /** This registers a buffer that will be used to send data to the remote node.
790 * Multiple buffers can be registered, in which case data will be sent in the order the buffers were registered.
791 * While there are still buffers with unsent data, the poll callback will not be called.
793 * @param channel A handle for the channel.
794 * @param data A pointer to a buffer containing data sent by the source, or NULL if there is no data to send.
795 * After meshlink_channel_aio_send() returns, the buffer may not be modified or freed by the application
796 * until the callback routine is called.
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 buffer.
799 * @param priv A private pointer which was set by the application when submitting the buffer.
801 * @return True if the buffer was enqueued, false otherwise.
803 bool channel_aio_send(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
804 return meshlink_channel_aio_send(handle, channel, data, len, cb, priv);
807 /// Transmit data on a channel asynchronously from a filedescriptor
808 /** This will read up to the specified length number of bytes from the given filedescriptor, and send it over the channel.
809 * The callback may be returned early if there is an error reading from the filedescriptor.
810 * While there is still with unsent data, the poll callback will not be called.
812 * @param channel A handle for the channel.
813 * @param fd A file descriptor from which data will be read.
814 * @param len The length of the data, or 0 if there is no data to send.
815 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
816 * @param priv A private pointer which was set by the application when submitting the buffer.
818 * @return True if the buffer was enqueued, false otherwise.
820 bool channel_aio_fd_send(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
821 return meshlink_channel_aio_fd_send(handle, channel, fd, len, cb, priv);
824 /// Receive data on a channel asynchronously
825 /** This registers a buffer that will be filled with incoming channel data.
826 * Multiple buffers can be registered, in which case data will be received in the order the buffers were registered.
827 * While there are still buffers that have not been filled, the receive callback will not be called.
829 * @param channel A handle for the channel.
830 * @param data A pointer to a buffer that will be filled with incoming data.
831 * After meshlink_channel_aio_receive() returns, the buffer may not be modified or freed by the application
832 * until the callback routine is called.
833 * @param len The length of the data.
834 * @param cb A pointer to the function which will be called when MeshLink has finished using the buffer.
835 * @param priv A private pointer which was set by the application when submitting the buffer.
837 * @return True if the buffer was enqueued, false otherwise.
839 bool channel_aio_receive(channel *channel, const void *data, size_t len, meshlink_aio_cb_t cb, void *priv) {
840 return meshlink_channel_aio_receive(handle, channel, data, len, cb, priv);
843 /// Receive data on a channel asynchronously and send it to a filedescriptor
844 /** This will read up to the specified length number of bytes from the channel, and send it to the filedescriptor.
845 * The callback may be returned early if there is an error writing to the filedescriptor.
846 * While there is still unread data, the receive callback will not be called.
848 * @param channel A handle for the channel.
849 * @param fd A file descriptor to which data will be written.
850 * @param len The length of the data.
851 * @param cb A pointer to the function which will be called when MeshLink has finished using the filedescriptor.
852 * @param priv A private pointer which was set by the application when submitting the buffer.
854 * @return True if the buffer was enqueued, false otherwise.
856 bool channel_aio_fd_receive(channel *channel, int fd, size_t len, meshlink_aio_fd_cb_t cb, void *priv) {
857 return meshlink_channel_aio_fd_receive(handle, channel, fd, len, cb, priv);
860 /// Get the amount of bytes in the send buffer.
861 /** This returns the amount of bytes in the send buffer.
862 * These bytes have not been received by the peer yet.
864 * @param channel A handle for the channel.
866 * @return The amount of un-ACKed bytes in the send buffer.
868 size_t channel_get_sendq(channel *channel) {
869 return meshlink_channel_get_sendq(handle, channel);
872 /// Get the amount of bytes in the receive buffer.
873 /** This returns the amount of bytes in the receive buffer.
874 * These bytes have not been processed by the application yet.
876 * @param channel A handle for the channel.
878 * @return The amount of bytes in the receive buffer.
880 size_t channel_get_recvq(channel *channel) {
881 return meshlink_channel_get_recvq(handle, channel);
884 /// Enable or disable zeroconf discovery of local peers
885 /** This controls whether zeroconf discovery using the Catta library will be
886 * enabled to search for peers on the local network. By default, it is enabled.
888 * @param enable Set to true to enable discovery, false to disable.
890 void enable_discovery(bool enable = true) {
891 meshlink_enable_discovery(handle, enable);
894 /// Set device class timeouts
895 /** This sets the ping interval and timeout for a given device class.
897 * @param devclass The device class to update
898 * @param pinginterval The interval between keepalive packets, in seconds. The default is 60.
899 * @param pingtimeout The required time within which a peer should respond, in seconds. The default is 5.
900 * The timeout must be smaller than the interval.
902 void set_dev_class_timeouts(dev_class_t devclass, int pinginterval, int pingtimeout);
906 mesh(const mesh &) /* TODO: C++11: = delete */;
907 void operator=(const mesh &) /* TODO: C++11: = delete */;
909 /// static callback trampolines:
910 static void receive_trampoline(meshlink_handle_t *handle, meshlink_node_t *source, const void *data, size_t length) {
911 if(!(handle->priv)) {
915 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
916 that->receive(static_cast<node *>(source), data, length);
919 static void node_status_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, bool reachable) {
920 if(!(handle->priv)) {
924 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
925 that->node_status(static_cast<node *>(peer), reachable);
928 static void node_pmtu_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer, uint16_t pmtu) {
929 if(!(handle->priv)) {
933 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
934 that->node_pmtu(static_cast<node *>(peer), pmtu);
937 static void node_duplicate_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
938 if(!(handle->priv)) {
942 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
943 that->node_duplicate(static_cast<node *>(peer));
946 static void log_trampoline(meshlink_handle_t *handle, log_level_t level, const char *message) {
947 if(!(handle->priv)) {
951 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
952 that->log(level, message);
955 static void connection_try_trampoline(meshlink_handle_t *handle, meshlink_node_t *peer) {
956 if(!(handle->priv)) {
960 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
961 that->connection_try(static_cast<node *>(peer));
964 static bool channel_accept_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, uint16_t port, const void *data, size_t len) {
965 if(!(handle->priv)) {
969 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
970 bool accepted = that->channel_accept(static_cast<meshlink::channel *>(channel), port, data, len);
973 meshlink_set_channel_receive_cb(handle, channel, &channel_receive_trampoline);
974 meshlink_set_channel_poll_cb(handle, channel, &channel_poll_trampoline);
980 static void channel_receive_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, const void *data, size_t len) {
981 if(!(handle->priv)) {
985 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
986 that->channel_receive(static_cast<meshlink::channel *>(channel), data, len);
989 static void channel_poll_trampoline(meshlink_handle_t *handle, meshlink_channel *channel, size_t len) {
990 if(!(handle->priv)) {
994 meshlink::mesh *that = static_cast<mesh *>(handle->priv);
995 that->channel_poll(static_cast<meshlink::channel *>(channel), len);
998 meshlink_handle_t *handle;
1001 static inline const char *strerror(errno_t err = meshlink_errno) {
1002 return meshlink_strerror(err);
1005 /// Destroy a MeshLink instance.
1006 /** This function remove all configuration files of a MeshLink instance. It should only be called when the application
1007 * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
1010 * @param confbase The directory in which MeshLink stores its configuration files.
1011 * After the function returns, the application is free to overwrite or free @a confbase @a.
1013 * @return This function will return true if the MeshLink instance was successfully destroyed, false otherwise.
1015 static inline bool destroy(const char *confbase) {
1016 return meshlink_destroy(confbase);