#ifndef MESHLINK_H
#define MESHLINK_H
+#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
+#include <unistd.h>
#ifdef __cplusplus
extern "C" {
#endif
+/// The length in bytes of a signature made with meshlink_sign()
+#define MESHLINK_SIGLEN 64
+
/// A handle for an instance of MeshLink.
typedef struct meshlink_handle meshlink_handle_t;
/// A handle for a MeshLink node.
typedef struct meshlink_node meshlink_node_t;
+/// A handle for a MeshLink channel.
+typedef struct meshlink_channel meshlink_channel_t;
+
/// Code of most recent error encountered.
typedef enum {
MESHLINK_OK, ///< Everything is fine
MESHLINK_ENOMEM, ///< Out of memory
MESHLINK_ENOENT, ///< Node is not known
} meshlink_errno_t;
-typedef struct outpacketqueue {
- meshlink_node_t *destination;
- const void *data;
- unsigned int len;
-} outpacketqueue_t;
+
+/// A variable holding the last encountered error from MeshLink.
+extern __thread meshlink_errno_t meshlink_errno;
#ifndef MESHLINK_INTERNAL_H
struct meshlink_handle {
- meshlink_errno_t meshlink_errno; ///< Code of the last encountered error.
- const char *errstr; ///< Textual representation of most recent error encountered.
};
struct meshlink_node {
void *priv; ///< Private pointer which the application can set at will.
};
+struct meshlink_channel {
+};
+
#endif // MESHLINK_INTERNAL_H
/// Get the text for the given MeshLink error code.
*/
extern const char *meshlink_strerror(meshlink_errno_t errno);
-/// Initialize MeshLink's configuration directory.
-/** This function causes MeshLink to initialize its configuration directory,
- * if it hasn't already been initialized.
- * It only has to be run the first time the application starts,
- * but it is not a problem if it is run more than once, as long as
- * the arguments given are the same.
+/// Open or create a MeshLink instance.
+/** This function opens or creates a MeshLink instance.
+ * The state is stored in the configuration directory passed in the variable @a confbase @a.
+ * If the configuration directory does not exist yet, for example when it is the first time
+ * this instance is opened, the configuration directory will be automatically created and initialized.
+ * However, the parent directory should already exist, otherwise an error will be returned.
+ *
+ * The name given should be a unique identifier for this instance.
+ *
+ * This function returns a pointer to a struct meshlink_handle that will be allocated by MeshLink.
+ * When the application does no longer need to use this handle, it must call meshlink_close() to
+ * free its resources.
*
* This function does not start any network I/O yet. The application should
* first set callbacks, and then call meshlink_start().
*
* @param confbase The directory in which MeshLink will store its configuration files.
+ * After the function returns, the application is free to overwrite or free @a confbase @a.
* @param name The name which this instance of the application will use in the mesh.
+ * After the function returns, the application is free to overwrite or free @a name @a.
*
- * @return This function will return true if MeshLink has succesfully set up its configuration files, false otherwise.
+ * @return A pointer to a meshlink_handle_t which represents this instance of MeshLink.
+ * The pointer is valid until meshlink_close() is called.
*/
extern meshlink_handle_t *meshlink_open(const char *confbase, const char *name);
/// Close the MeshLink handle.
/** This function calls meshlink_stop() if necessary,
- * and frees all memory allocated by MeshLink.
- * Afterwards, the handle and any pointers to a struct meshlink_node are invalid.
+ * and frees the struct meshlink_handle and all associacted memory allocated by MeshLink.
+ * Afterwards, the handle and any pointers to a struct meshlink_node or struct meshlink_channel are invalid.
*
* @param mesh A handle which represents an instance of MeshLink.
*/
/** @param mesh A handle which represents an instance of MeshLink.
* @param source A pointer to a meshlink_node_t describing the source of the data.
* @param data A pointer to a buffer containing the data sent by the source.
+ * The pointer is only valid during the lifetime of the callback.
+ * The callback should mempcy() the data if it needs to be available outside the callback.
* @param len The length of the received data.
*/
typedef void (*meshlink_receive_cb_t)(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len);
*
* @param mesh A handle which represents an instance of MeshLink.
* @param cb A pointer to the function which will be called when another node sends data to the local node.
+ * If a NULL pointer is given, the callback will be disabled.
*/
extern void meshlink_set_receive_cb(meshlink_handle_t *mesh, meshlink_receive_cb_t cb);
*
* @param mesh A handle which represents an instance of MeshLink.
* @param cb A pointer to the function which will be called when another node's status changes.
+ * If a NULL pointer is given, the callback will be disabled.
*/
extern void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb);
/** @param mesh A handle which represents an instance of MeshLink.
* @param level An enum describing the severity level of the message.
* @param text A pointer to a string containing the textual log message.
+ * This pointer is only valid for the duration of the callback.
+ * The application should strdup() the text if it has to be available outside the callback.
*/
typedef void (*meshlink_log_cb_t)(meshlink_handle_t *mesh, meshlink_log_level_t level, const char *text);
* @param mesh A handle which represents an instance of MeshLink.
* @param level An enum describing the minimum severity level. Debugging information with a lower level will not trigger the callback.
* @param cb A pointer to the function which will be called when another node sends data to the local node.
+ * If a NULL pointer is given, the callback will be disabled.
*/
extern void meshlink_set_log_cb(meshlink_handle_t *mesh, meshlink_log_level_t level, meshlink_log_cb_t cb);
* @param mesh A handle which represents an instance of MeshLink.
* @param destination A pointer to a meshlink_node_t describing the destination for the data.
* @param data A pointer to a buffer containing the data to be sent to the source.
+ * After meshlink_send() returns, the application is free to overwrite or free this buffer.
* @param len The length of the data.
* @return This function will return true if MeshLink has queued the message for transmission, and false otherwise.
* A return value of true does not guarantee that the message will actually arrive at the destination.
*
* @param mesh A handle which represents an instance of MeshLink.
* @param name The name of the node for which a handle is requested.
+ * After this function returns, the application is free to overwrite or free @a name @a.
*
* @return A pointer to a meshlink_node_t which represents the requested node,
* or NULL if the requested node does not exist.
+ * The pointer is guaranteed to be valid until meshlink_close() is called.
*/
extern meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name);
*
* @param mesh A handle which represents an instance of MeshLink.
* @param nodes A pointer to an array of pointers to meshlink_node_t, which should be allocated by the application.
+ * The pointers are valid until meshlink_close() is called.
* @param nmemb The maximum number of pointers that can be stored in the nodes array.
*
- * @return The number of known nodes. This can be larger than nmemb, in which case not all nodes were stored in the nodes array.
+ * @return The number of known nodes, or -1 in case of an error.
+ * The returned number of nodes can be larger than nmemb, in which case not all nodes were stored in the nodes array.
*/
-extern size_t meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t nmemb);
+extern ssize_t meshlink_get_all_nodes(meshlink_handle_t *mesh, meshlink_node_t **nodes, size_t nmemb);
/// Sign data using the local node's MeshLink key.
/** This function signs data using the local node's MeshLink key.
* @param mesh A handle which represents an instance of MeshLink.
* @param data A pointer to a buffer containing the data to be signed.
* @param len The length of the data to be signed.
+ * @param signature A pointer to a buffer where the signature will be stored.
+ * The buffer must be allocated by the application, and should be at least MESHLINK_SIGLEN bytes big.
+ * @param siglen The size of the signature buffer. Will be changed after the call to match the size of the signature itself.
*
- * @return This function returns a pointer to a string containing the signature, or NULL in case of an error.
- * The application should call free() after it has finished using the signature.
+ * @return This function returns true if the signature was correctly generated, false otherwise.
*/
-extern char *meshlink_sign(meshlink_handle_t *mesh, const char *data, size_t len);
+extern bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, void *signature, size_t *siglen);
/// Verify the signature generated by another node of a piece of data.
/** This function verifies the signature that another node generated for a piece of data.
* @param source A pointer to a meshlink_node_t describing the source of the signature.
* @param data A pointer to a buffer containing the data to be verified.
* @param len The length of the data to be verified.
- * @param signature A pointer to a string containing the signature.
+ * @param signature A pointer to a buffer where the signature will be stored.
+ * @param siglen A pointer to a variable holding the size of the signature buffer.
+ * The contents of the variable will be changed by meshlink_sign() to reflect the actual size of the signature.
*
* @return This function returns true if the signature is valid, false otherwise.
*/
-extern bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const char *data, size_t len, const char *signature);
+extern bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen);
/// Add an Address for the local node.
/** This function adds an Address for the local node, which will be used for invitation URLs.
*
* @param mesh A handle which represents an instance of MeshLink.
* @param name The name that the invitee will use in the mesh.
+ * After this function returns, the application is free to overwrite or free @a name @a.
*
* @return This function returns a string that contains the invitation URL.
* The application should call free() after it has finished using the URL.
*
* @param mesh A handle which represents an instance of MeshLink.
* @param invitation A string containing the invitation URL.
+ * After this function returns, the application is free to overwrite or free @a invitation @a.
*
* @return This function returns true if the local node joined the mesh it was invited to, false otherwise.
*/
*
* @param mesh A handle which represents an instance of MeshLink.
* @param data A string containing the other node's exported key and addresses.
+ * After this function returns, the application is free to overwrite or free @a data @a.
*
* @return This function returns true if the data was valid and the other node has been granted access to the mesh, false otherwise.
*/
*/
extern void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node);
+/// A callback for accepting incoming channels.
+/** This function is called whenever a remote node wants to open a channel to the local node.
+ * The application then has to decide whether to accept or reject this channel.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the incoming channel.
+ * If the application accepts the incoming channel by returning true,
+ * then this handle is valid until meshlink_channel_close() is called on it.
+ * If the application rejects the incoming channel by returning false,
+ * then this handle is invalid after the callback returns
+ * (the callback does not need to call meshlink_channel_close() itself in this case).
+ * @param node The node from which this channel is being initiated.
+ * The pointer is guaranteed to be valid until meshlink_close() is called.
+ * @param port The port number the peer wishes to connect to.
+ * @param data A pointer to a buffer containing data already received. (Not yet used.)
+ * The pointer is only valid during the lifetime of the callback.
+ * The callback should mempcy() the data if it needs to be available outside the callback.
+ * @param len The length of the data. (Not yet used.)
+ *
+ * @return This function should return true if the application accepts the incoming channel, false otherwise.
+ * If returning false, the channel is invalid and may not be used anymore.
+ */
+typedef bool (*meshlink_channel_accept_cb_t)(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_node_t *node, uint16_t port, const void *data, size_t len);
+
+/// A callback for receiving data from a channel.
+/** This function is called whenever a remote node wants to open a channel to the local node.
+ * The application then has to decide whether to accept or reject this channel.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param data A pointer to a buffer containing data sent by the source.
+ * The pointer is only valid during the lifetime of the callback.
+ * The callback should mempcy() the data if it needs to be available outside the callback.
+ * @param len The length of the data.
+ */
+typedef void (*meshlink_channel_receive_cb_t)(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len);
+
+/// Set the accept callback.
+/** This functions sets the callback that is called whenever another node sends data to the local node.
+ * The callback is run in MeshLink's own thread.
+ * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
+ * to hand the data over to the application's thread.
+ * The callback should also not block itself and return as quickly as possible.
+ *
+ * If no accept callback is set, incoming channels are rejected.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param cb A pointer to the function which will be called when another node sends data to the local node.
+ * If a NULL pointer is given, the callback will be disabled.
+ */
+extern void meshlink_set_channel_accept_cb(meshlink_handle_t *mesh, meshlink_channel_accept_cb_t cb);
+
+/// Set the receive callback.
+/** This functions sets the callback that is called whenever another node sends data to the local node.
+ * The callback is run in MeshLink's own thread.
+ * It is therefore important that the callback uses apprioriate methods (queues, pipes, locking, etc.)
+ * to hand the data over to the application's thread.
+ * The callback should also not block itself and return as quickly as possible.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param cb A pointer to the function which will be called when another node sends data to the local node.
+ * If a NULL pointer is given, the callback will be disabled.
+ */
+extern void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_receive_cb_t cb);
+
+/// Open a reliable stream channel to another node.
+/** This function is called whenever a remote node wants to open a channel to the local node.
+ * The application then has to decide whether to accept or reject this channel.
+ *
+ * This function returns a pointer to a struct meshlink_channel that will be allocated by MeshLink.
+ * When the application does no longer need to use this channel, it must call meshlink_close()
+ * to free its resources.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param node The node to which this channel is being initiated.
+ * @param port The port number the peer wishes to connect to.
+ * @param cb A pointer to the function which will be called when the remote node sends data to the local node.
+ * @param data A pointer to a buffer containing data to already queue for sending.
+ * After meshlink_send() returns, the application is free to overwrite or free this buffer.
+ * @param len The length of the data.
+ *
+ * @return A handle for the channel, or NULL in case of an error.
+ * The handle is valid until meshlink_channel_close() is called.
+ */
+extern meshlink_channel_t *meshlink_channel_open(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len);
+
+/// Partially close a reliable stream channel.
+/** This shuts down the read or write side of a channel, or both, without closing the handle.
+ * It can be used to inform the remote node that the local node has finished sending all data on the channel,
+ * but still allows waiting for incoming data from the remote node.
+ *
+ * Shutting down the receive direction is also possible, and is equivalent to setting the receive callback to NULL.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param direction Must be one of SHUT_RD, SHUT_WR or SHUT_RDWR.
+ */
+extern void meshlink_channel_shutdown(meshlink_handle_t *mesh, meshlink_channel_t *channel, int direction);
+
+/// Close a reliable stream channel.
+/** This informs the remote node that the local node has finished sending all data on the channel.
+ * It also causes the local node to stop accepting incoming data from the remote node.
+ * It will free the struct meshlink_channel and all associated resources.
+ * Afterwards, the channel handle is invalid and must not be used any more.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ */
+extern void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t *channel);
+
+/// Transmit data on a channel
+/** This queues data to send to the remote node.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param data A pointer to a buffer containing data sent by the source.
+ * After meshlink_send() returns, the application is free to overwrite or free this buffer.
+ * @param len The length of the data.
+ *
+ * @return The amount of data that was queued, which can be less than len, or a negative value in case of an error.
+ */
+extern ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len);
+
#ifdef __cplusplus
}
#endif
projects / meshlink / blobdiff