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.
29 /// Severity of log messages generated by MeshLink.
30 typedef meshlink_log_level_t log_level_t;
32 /// Code of most recent error encountered.
33 typedef meshlink_errno_t errno_t;
35 /// A callback for receiving data from the mesh.
36 /** @param mesh A handle which represents an instance of MeshLink.
37 * @param source A pointer to a meshlink::node describing the source of the data.
38 * @param data A pointer to a buffer containing the data sent by the source.
39 * @param len The length of the received data.
41 typedef void (*receive_cb_t)(mesh *mesh, node *source, const void *data, size_t len);
43 /// A callback reporting node status changes.
44 /** @param mesh A handle which represents an instance of MeshLink.
45 * @param node A pointer to a meshlink::node describing the node whose status changed.
46 * @param reachable True if the node is reachable, false otherwise.
48 typedef void (*node_status_cb_t)(mesh *mesh, node *node, bool reachable);
50 /// A callback for receiving log messages generated by MeshLink.
51 /** @param mesh A handle which represents an instance of MeshLink.
52 * @param level An enum describing the severity level of the message.
53 * @param text A pointer to a string containing the textual log message.
55 typedef void (*log_cb_t)(mesh *mesh, log_level_t level, const char *text);
57 /// A class describing a MeshLink node.
58 class node: public meshlink_node_t {
61 /// A class describing a MeshLink mesh.
62 class mesh: public meshlink_handle_t {
64 // TODO: delete constructor, add a destructor.
67 /** This function causes MeshLink to open network sockets, make outgoing connections, and
68 * create a new thread, which will handle all network I/O.
70 * @return This function will return true if MeshLink has succesfully started its thread, false otherwise.
73 return meshlink_start(this);
77 /** This function causes MeshLink to disconnect from all other nodes,
78 * close all sockets, and shut down its own thread.
84 /// Set the receive callback.
85 /** This functions sets the callback that is called whenever another node sends data to the local node.
86 * The callback is run in MeshLink's own thread.
87 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
88 * to hand the data over to the application's thread.
89 * The callback should also not block itself and return as quickly as possible.
91 * @param cb A pointer to the function which will be called when another node sends data to the local node.
93 void set_receive_cb(receive_cb_t cb) {
94 meshlink_set_receive_cb(this, (meshlink_receive_cb_t)cb);
97 /// Set the node status callback.
98 /** This functions sets the callback that is called whenever another node's status changed.
99 * The callback is run in MeshLink's own thread.
100 * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
101 * to hand the data over to the application's thread.
102 * The callback should also not block itself and return as quickly as possible.
104 * @param cb A pointer to the function which will be called when another node's status changes.
106 void set_node_status_cb(node_status_cb_t cb) {
107 meshlink_set_node_status_cb(this, (meshlink_node_status_cb_t)cb);
110 /// Set the log callback.
111 /** This functions sets the callback that is called whenever MeshLink has some information to log.
112 * The callback is run in MeshLink's own thread.
113 * It is 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 level An enum describing the minimum severity level. Debugging information with a lower level will not trigger the callback.
118 * @param cb A pointer to the function which will be called when another node sends data to the local node.
120 void set_log_cb(meshlink_log_level_t level, log_cb_t cb) {
121 meshlink_set_log_cb(this, level, (meshlink_log_cb_t)cb);
124 /// Send data to another node.
125 /** This functions sends one packet of data to another node in the mesh.
126 * The packet is sent using UDP semantics, which means that
127 * the packet is sent as one unit and is received as one unit,
128 * and that there is no guarantee that the packet will arrive at the destination.
129 * The application should take care of getting an acknowledgement and retransmission if necessary.
131 * @param destination A pointer to a meshlink::node describing the destination for the data.
132 * @param data A pointer to a buffer containing the data to be sent to the source.
133 * @param len The length of the data.
134 * @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
135 * A return value of true does not guarantee that the message will actually arrive at the destination.
137 bool send(node *destination, const void *data, unsigned int len) {
138 return meshlink_send(this, destination, data, len);
141 /// Get a handle for a specific node.
142 /** This function returns a handle for the node with the given name.
144 * @param name The name of the node for which a handle is requested.
146 * @return A pointer to a meshlink::node which represents the requested node,
147 * or NULL if the requested node does not exist.
149 node *get_node(const char *name) {
150 return (node *)meshlink_get_node(this, name);
153 /// Get a list of all nodes.
154 /** This function returns a list with handles for all known nodes.
156 * @param nodes A pointer to an array of pointers to meshlink::node, which should be allocated by the application.
157 * @param nmemb The maximum number of pointers that can be stored in the nodes array.
159 * @param return The number of known nodes. This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
161 size_t get_all_nodes(node **nodes, size_t nmemb) {
162 return meshlink_get_all_nodes(this, (meshlink_node_t **)nodes, nmemb);
165 /// Sign data using the local node's MeshLink key.
166 /** This function signs data using the local node's MeshLink key.
167 * The generated signature can be securely verified by other nodes.
169 * @param data A pointer to a buffer containing the data to be signed.
170 * @param len The length of the data to be signed.
172 * @return This function returns a pointer to a string containing the signature, or NULL in case of an error.
173 * The application should call free() after it has finished using the signature.
175 char *sign(const char *data, size_t len) {
176 return meshlink_sign(this, data, len);
179 /// Verify the signature generated by another node of a piece of data.
180 /** This function verifies the signature that another node generated for a piece of data.
182 * @param source A pointer to a meshlink_node_t describing the source of the signature.
183 * @param data A pointer to a buffer containing the data to be verified.
184 * @param len The length of the data to be verified.
185 * @param signature A pointer to a string containing the signature.
187 * @return This function returns true if the signature is valid, false otherwise.
189 bool verify(node *source, const char *data, size_t len, const char *signature) {
190 return meshlink_verify(this, source, data, len, signature);
193 /// Add an Address for the local node.
194 /** This function adds an Address for the local node, which will be used for invitation URLs.
196 * @param address A string containing the address, which can be either in numeric format or a hostname.
198 * @return This function returns true if the address was added, false otherwise.
200 bool add_address(const char *address) {
201 return meshlink_add_address(this, address);
204 /// Invite another node into the mesh.
205 /** This function generates an invitation that can be used by another node to join the same mesh as the local node.
206 * The generated invitation is a string containing a URL.
207 * This URL should be passed by the application to the invitee in a way that no eavesdroppers can see the URL.
208 * The URL can only be used once, after the user has joined the mesh the URL is no longer valid.
210 * @param name The name that the invitee will use in the mesh.
212 * @return This function returns a string that contains the invitation URL.
213 * The application should call free() after it has finished using the URL.
215 char *invite(const char *name) {
216 return meshlink_invite(this, name);
219 /// Use an invitation to join a mesh.
220 /** This function allows the local node to join an existing mesh using an invitation URL generated by another node.
221 * An invitation can only be used if the local node has never connected to other nodes before.
222 * After a succesfully accepted invitation, the name of the local node may have changed.
224 * @param invitation A string containing the invitation URL.
226 * @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
228 bool join(const char *invitation) {
229 return meshlink_join(this, invitation);
232 /// Export the local node's key and addresses.
233 /** This function generates a string that contains the local node's public key and one or more IP addresses.
234 * The application can pass it in some way to another node, which can then import it,
235 * granting the local node access to the other node's mesh.
237 * @return This function returns a string that contains the exported key and addresses.
238 * The application should call free() after it has finished using this string.
241 return meshlink_export(this);
244 /// Import another node's key and addresses.
245 /** This function accepts a string containing the exported public key and addresses of another node.
246 * By importing this data, the local node grants the other node access to its mesh.
248 * @param data A string containing the other node's exported key and addresses.
250 * @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
252 bool import_key(const char *data) {
253 return meshlink_import(this, data);
256 /// Blacklist a node from the mesh.
257 /** This function causes the local node to blacklist another node.
258 * The local node will drop any existing connections to that node,
259 * and will not send data to it nor accept any data received from it any more.
261 * @param node A pointer to a meshlink::node describing the node to be blacklisted.
263 void blacklist(node *node) {
264 return meshlink_blacklist(this, node);
268 /// Initialize MeshLink's configuration directory.
269 /** This function causes MeshLink to initialize its configuration directory,
270 * if it hasn't already been initialized.
271 * It only has to be run the first time the application starts,
272 * but it is not a problem if it is run more than once, as long as
273 * the arguments given are the same.
275 * This function does not start any network I/O yet. The application should
276 * first set callbacks, and then call meshlink_start().
278 * @param confbase The directory in which MeshLink will store its configuration files.
279 * @param name The name which this instance of the application will use in the mesh.
281 * @return This function will return a pointer to a meshlink::mesh if MeshLink has succesfully set up its configuration files, NULL otherwise.
283 static mesh *open(const char *confbase, const char *name) {
284 return (mesh *)meshlink_open(confbase, name);
287 /// Close the MeshLink handle.
288 /** This function calls meshlink_stop() if necessary,
289 * and frees all memory allocated by MeshLink.
290 * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
292 static void close(mesh *mesh) {
293 meshlink_close(mesh);
297 #endif // MESHLINKPP_H