2 meshlink++.h -- MeshLink C++ API
3 Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
30 /// Severity of log messages generated by MeshLink.
31 typedef meshlink_log_level_t log_level_t;
33 /// Code of most recent error encountered.
34 typedef meshlink_errno_t errno_t;
36 /// A callback for receiving data from the mesh.
37 /** @param mesh A handle which represents an instance of MeshLink.
38 * @param source A pointer to a meshlink::node describing the source of the data.
39 * @param data A pointer to a buffer containing the data sent by the source.
40 * @param len The length of the received data.
42 typedef void (*receive_cb_t)(mesh *mesh, node *source, const void *data, size_t len);
44 /// A callback reporting node status changes.
45 /** @param mesh A handle which represents an instance of MeshLink.
46 * @param node A pointer to a meshlink::node describing the node whose status changed.
47 * @param reachable True if the node is reachable, false otherwise.
49 typedef void (*node_status_cb_t)(mesh *mesh, node *node, bool reachable);
51 /// A callback for receiving log messages generated by MeshLink.
52 /** @param mesh A handle which represents an instance of MeshLink.
53 * @param level An enum describing the severity level of the message.
54 * @param text A pointer to a string containing the textual log message.
56 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
58 /// A callback for accepting incoming channels.
59 /** @param mesh A handle which represents an instance of MeshLink.
60 * @param channel A handle for the incoming channel.
61 * @param node The node from which this channel is being initiated.
62 * @param port The port number the peer wishes to connect to.
63 * @param data A pointer to a buffer containing data already received. (Not yet used.)
64 * @param len The length of the data. (Not yet used.)
66 * @return This function should return true if the application accepts the incoming channel, false otherwise.
67 * If returning false, the channel is invalid and may not be used anymore.
69 typedef bool (*channel_accept_cb_t)(mesh *mesh, channel *channel, node *node, uint16_t port, const void *data, size_t len);
71 /// A callback for receiving data from a channel.
72 /** @param mesh A handle which represents an instance of MeshLink.
73 * @param channel A handle for the channel.
74 * @param data A pointer to a buffer containing data sent by the source.
75 * @param len The length of the data.
77 typedef void (*channel_receive_cb_t)(mesh *mesh, channel *channel, const void *data, size_t len);
79 /// A class describing a MeshLink node.
80 class node: public meshlink_node_t {
83 /// A class describing a MeshLink channel.
84 class channel: public meshlink_channel_t {
87 /// A class describing a MeshLink mesh.
88 class mesh: public meshlink_handle_t {
90 // TODO: delete constructor, add a destructor.
93 /** This function causes MeshLink to open network sockets, make outgoing connections, and
94 * create a new thread, which will handle all network I/O.
96 * @return This function will return true if MeshLink has succesfully started its thread, false otherwise.
99 return meshlink_start(this);
103 /** This function causes MeshLink to disconnect from all other nodes,
104 * close all sockets, and shut down its own thread.
110 /// Set the receive callback.
111 /** This functions sets the callback that is called whenever another node sends data to the local node.
112 * The callback is run in MeshLink's own thread.
113 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
114 * to hand the data over to the application's thread.
115 * The callback should also not block itself and return as quickly as possible.
117 * @param cb A pointer to the function which will be called when another node sends data to the local node.
119 void set_receive_cb(receive_cb_t cb) {
120 meshlink_set_receive_cb(this, (meshlink_receive_cb_t)cb);
123 /// Set the node status callback.
124 /** This functions sets the callback that is called whenever another node's status changed.
125 * The callback is run in MeshLink's own thread.
126 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
127 * to hand the data over to the application's thread.
128 * The callback should also not block itself and return as quickly as possible.
130 * @param cb A pointer to the function which will be called when another node's status changes.
132 void set_node_status_cb(node_status_cb_t cb) {
133 meshlink_set_node_status_cb(this, (meshlink_node_status_cb_t)cb);
136 /// Set the log callback.
137 /** This functions sets the callback that is called whenever MeshLink has some information to log.
138 * The callback is run in MeshLink's own thread.
139 * It is important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
140 * to hand the data over to the application's thread.
141 * The callback should also not block itself and return as quickly as possible.
143 * @param level An enum describing the minimum severity level. Debugging information with a lower level will not trigger the callback.
144 * @param cb A pointer to the function which will be called when another node sends data to the local node.
146 void set_log_cb(meshlink_log_level_t level, log_cb_t cb) {
147 meshlink_set_log_cb(this, level, (meshlink_log_cb_t)cb);
150 /// Send data to another node.
151 /** This functions sends one packet of data to another node in the mesh.
152 * The packet is sent using UDP semantics, which means that
153 * the packet is sent as one unit and is received as one unit,
154 * and that there is no guarantee that the packet will arrive at the destination.
155 * The application should take care of getting an acknowledgement and retransmission if necessary.
157 * @param destination A pointer to a meshlink::node describing the destination for the data.
158 * @param data A pointer to a buffer containing the data to be sent to the source.
159 * @param len The length of the data.
160 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
161 * A return value of true does not guarantee that the message will actually arrive at the destination.
163 bool send(node *destination, const void *data, unsigned int len) {
164 return meshlink_send(this, destination, data, len);
167 /// Get a handle for a specific node.
168 /** This function returns a handle for the node with the given name.
170 * @param name The name of the node for which a handle is requested.
172 * @return A pointer to a meshlink::node which represents the requested node,
173 * or NULL if the requested node does not exist.
175 node *get_node(const char *name) {
176 return (node *)meshlink_get_node(this, name);
179 /// Get a list of all nodes.
180 /** This function returns a list with handles for all known nodes.
182 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
183 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
185 * @return The number of known nodes, or -1 in case of an error.
186 * This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
188 node **get_all_nodes(node **nodes, size_t *nmemb) {
189 return (node **)meshlink_get_all_nodes(this, (meshlink_node_t **)nodes, nmemb);
192 /// Sign data using the local node's MeshLink key.
193 /** This function signs data using the local node's MeshLink key.
194 * The generated signature can be securely verified by other nodes.
196 * @param data A pointer to a buffer containing the data to be signed.
197 * @param len The length of the data to be signed.
198 * @param signature A pointer to a buffer where the signature will be stored.
199 * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
201 * @return This function returns true if the signature is valid, false otherwise.
203 bool sign(const void *data, size_t len, void *signature, size_t *siglen) {
204 return meshlink_sign(this, data, len, signature, siglen);
207 /// Verify the signature generated by another node of a piece of data.
208 /** This function verifies the signature that another node generated for a piece of data.
210 * @param source A pointer to a meshlink_node_t describing the source of the signature.
211 * @param data A pointer to a buffer containing the data to be verified.
212 * @param len The length of the data to be verified.
213 * @param signature A pointer to a string containing the signature.
214 * @param siglen The size of the signature.
216 * @return This function returns true if the signature is valid, false otherwise.
218 bool verify(node *source, const void *data, size_t len, const void *signature, size_t siglen) {
219 return meshlink_verify(this, source, data, len, signature, siglen);
222 /// Add an Address for the local node.
223 /** This function adds an Address for the local node, which will be used for invitation URLs.
225 * @param address A string containing the address, which can be either in numeric format or a hostname.
227 * @return This function returns true if the address was added, false otherwise.
229 bool add_address(const char *address) {
230 return meshlink_add_address(this, address);
233 /// Invite another node into the mesh.
234 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
235 * The generated invitation is a string containing a URL.
236 * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
237 * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
239 * @param name The name that the invitee will use in the mesh.
241 * @return This function returns a string that contains the invitation URL.
242 * The application should call free() after it has finished using the URL.
244 char *invite(const char *name) {
245 return meshlink_invite(this, name);
248 /// Use an invitation to join a mesh.
249 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
250 * An invitation can only be used if the local node has never connected to other nodes before.
251 * After a succesfully accepted invitation, the name of the local node may have changed.
253 * @param invitation A string containing the invitation URL.
255 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
257 bool join(const char *invitation) {
258 return meshlink_join(this, invitation);
261 /// Export the local node's key and addresses.
262 /** This function generates a string that contains the local node's public key and one or more IP addresses.
263 * The application can pass it in some way to another node, which can then import it,
264 * granting the local node access to the other node's mesh.
266 * @return This function returns a string that contains the exported key and addresses.
267 * The application should call free() after it has finished using this string.
270 return meshlink_export(this);
273 /// Import another node's key and addresses.
274 /** This function accepts a string containing the exported public key and addresses of another node.
275 * By importing this data, the local node grants the other node access to its mesh.
277 * @param data A string containing the other node's exported key and addresses.
279 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
281 bool import_key(const char *data) {
282 return meshlink_import(this, data);
285 /// Blacklist a node from the mesh.
286 /** This function causes the local node to blacklist another node.
287 * The local node will drop any existing connections to that node,
288 * and will not send data to it nor accept any data received from it any more.
290 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
292 void blacklist(node *node) {
293 return meshlink_blacklist(this, node);
296 /// Set the accept callback.
297 /** This functions sets the callback that is called whenever another node sends data to the local node.
298 * The callback is run in MeshLink's own thread.
299 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
300 * to hand the data over to 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 cb A pointer to the function which will be called when another node sends data to the local node.
306 void set_channel_accept_cb(channel *channel, channel_accept_cb_t cb) {
307 return meshlink_set_channel_accept_cb(this, (meshlink_channel_accept_cb_t)cb);
310 /// Open a reliable stream channel to another node.
311 /** This function is called whenever a remote node wants to open a channel to the local node.
312 * The application then has to decide whether to accept or reject this channel.
314 * @param node The node to which this channel is being initiated.
315 * @param port The port number the peer wishes to connect to.
316 * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
317 * @param data A pointer to a buffer containing data to already queue for sending.
318 * @param len The length of the data.
320 * @return A handle for the channel, or NULL in case of an error.
322 channel *channel_open(node *node, uint16_t port, channel_receive_cb_t cb, const void *data, size_t len) {
323 return (channel *)meshlink_channel_open(this, node, port, (meshlink_channel_receive_cb_t)cb, data, len);
326 /// Partially close a reliable stream channel.
327 /** This shuts down the read or write side of a channel, or both, without closing the handle.
328 * It can be used to inform the remote node that the local node has finished sending all data on the channel,
329 * but still allows waiting for incoming data from the remote node.
331 * @param channel A handle for the channel.
332 * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
334 void channel_shutdown(channel *channel, int direction) {
335 return meshlink_channel_shutdown(this, channel, direction);
338 /// Close a reliable stream channel.
339 /** This informs the remote node that the local node has finished sending all data on the channel.
340 * It also causes the local node to stop accepting incoming data from the remote node.
341 * Afterwards, the channel handle is invalid and must not be used any more.
343 * @param channel A handle for the channel.
345 void channel_close(meshlink_channel_t *channel) {
346 return meshlink_channel_close(this, channel);
349 /// Transmit data on a channel
350 /** This queues data to send to the remote node.
352 * @param channel A handle for the channel.
353 * @param data A pointer to a buffer containing data sent by the source.
354 * @param len The length of the data.
356 * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
358 ssize_t channel_send(channel *channel, void *data, size_t len) {
359 return meshlink_channel_send(this, channel, data, len);
364 /// Initialize MeshLink's configuration directory.
365 /** This function causes MeshLink to initialize its configuration directory,
366 * if it hasn't already been initialized.
367 * It only has to be run the first time the application starts,
368 * but it is not a problem if it is run more than once, as long as
369 * the arguments given are the same.
371 * This function does not start any network I/O yet. The application should
372 * first set callbacks, and then call meshlink_start().
374 * @param confbase The directory in which MeshLink will store its configuration files.
375 * @param name The name which this instance of the application will use in the mesh.
377 * @return This function will return a pointer to a meshlink::mesh if MeshLink has succesfully set up its configuration files, NULL otherwise.
379 static mesh *open(const char *confbase, const char *name) {
380 return (mesh *)meshlink_open(confbase, name);
383 /// Close the MeshLink handle.
384 /** This function calls meshlink_stop() if necessary,
385 * and frees all memory allocated by MeshLink.
386 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
388 static void close(mesh *mesh) {
389 meshlink_close(mesh);
392 static const char *strerror(errno_t err = meshlink_errno) {
393 return meshlink_strerror(err);
397 #endif // MESHLINKPP_H