+#ifndef MESHLINK_H
+#define MESHLINK_H
+
/*
meshlink.h -- MeshLink API
- Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
+ Copyright (C) 2014, 2017 Guus Sliepen <guus@meshlink.io>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
-#ifndef MESHLINK_H
-#define MESHLINK_H
-
#include <stdint.h>
#include <stdbool.h>
#include <stddef.h>
#include <unistd.h>
+#if defined(_WIN32)
+#include <winsock2.h>
+#else
+#include <sys/types.h>
+#include <sys/socket.h>
+#endif
+
#ifdef __cplusplus
extern "C" {
#endif
/// The length in bytes of a signature made with meshlink_sign()
-#define MESHLINK_SIGLEN (64)
+#define MESHLINK_SIGLEN (64ul)
+
+// The maximum length of fingerprints
+#define MESHLINK_FINGERPRINTLEN (64ul)
/// A handle for an instance of MeshLink.
typedef struct meshlink_handle meshlink_handle_t;
/// Code of most recent error encountered.
typedef enum {
MESHLINK_OK, ///< Everything is fine
+ MESHLINK_EINVAL, ///< Invalid parameter(s) to function call
MESHLINK_ENOMEM, ///< Out of memory
MESHLINK_ENOENT, ///< Node is not known
+ MESHLINK_EEXIST, ///< Node already exists
+ MESHLINK_EINTERNAL, ///< MeshLink internal error
+ MESHLINK_ERESOLV, ///< MeshLink could not resolve a hostname
+ MESHLINK_ESTORAGE, ///< MeshLink coud not load or write data from/to disk
+ MESHLINK_ENETWORK, ///< MeshLink encountered a network error
+ MESHLINK_EPEER, ///< A peer caused an error
} meshlink_errno_t;
+/// Device class
+typedef enum {
+ DEV_CLASS_BACKBONE = 0,
+ DEV_CLASS_STATIONARY = 1,
+ DEV_CLASS_PORTABLE = 2,
+ DEV_CLASS_UNKNOWN = 3,
+ _DEV_CLASS_MAX = 3
+} dev_class_t;
+
+/// Channel flags
+static const uint32_t MESHLINK_CHANNEL_RELIABLE = 1; // Data is retransmitted when packets are lost.
+static const uint32_t MESHLINK_CHANNEL_ORDERED = 2; // Data is delivered in-order to the application.
+static const uint32_t MESHLINK_CHANNEL_FRAMED = 4; // Data is delivered in chunks of the same length as data was originally sent.
+static const uint32_t MESHLINK_CHANNEL_DROP_LATE = 8; // When packets are reordered, late packets are ignored.
+static const uint32_t MESHLINK_CHANNEL_TCP = 3; // Select TCP semantics.
+static const uint32_t MESHLINK_CHANNEL_UDP = 0; // Select UDP semantics.
+
/// A variable holding the last encountered error from MeshLink.
/** This is a thread local variable that contains the error code of the most recent error
* encountered by a MeshLink API function called in the current thread.
#ifndef MESHLINK_INTERNAL_H
struct meshlink_handle {
- const char *name;
- void *priv;
+ const char *const name; ///< Textual name of ourself. It is stored in a nul-terminated C string, which is allocated by MeshLink.
+ void *priv; ///< Private pointer which may be set freely by the application, and is never used or modified by MeshLink.
};
struct meshlink_node {
- const char *name; ///< Textual name of this node. It is stored in a nul-terminated C string, which is allocated by MeshLink.
- void *priv; ///< Private pointer which may be set freely by the application, and is never used or modified by MeshLink.
+ const char *const name; ///< Textual name of this node. It is stored in a nul-terminated C string, which is allocated by MeshLink.
+ void *priv; ///< Private pointer which may be set freely by the application, and is never used or modified by MeshLink.
};
struct meshlink_channel {
+ struct meshlink_node *const node; ///< Pointer to the peer of this channel.
+ void *priv; ///< Private pointer which may be set freely by the application, and is never used or modified by MeshLink.
};
#endif // MESHLINK_INTERNAL_H
* 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.
+ * @param appname The application name which will be used in the mesh.
+ * After the function returns, the application is free to overwrite or free @a name @a.
+ * @param devclass The device class which will be used in the mesh.
*
* @return A pointer to a meshlink_handle_t which represents this instance of MeshLink, or NULL in case of an error.
* The pointer is valid until meshlink_close() is called.
*/
-extern meshlink_handle_t *meshlink_open(const char *confbase, const char *name);
+extern meshlink_handle_t *meshlink_open(const char *confbase, const char *name, const char *appname, dev_class_t devclass);
/// Start MeshLink.
/** This function causes MeshLink to open network sockets, make outgoing connections, and
* close all sockets, and shut down its own thread.
*
* This function always succeeds. It is allowed to call meshlink_stop() even if MeshLink is already stopped or has never been started.
+ * Channels that are still open will remain valid, but any communication via channels will stop as well.
*
* @param mesh A handle which represents an instance of MeshLink.
*/
/// Close the MeshLink handle.
/** This function calls meshlink_stop() if necessary,
- * and frees the struct meshlink_handle and all associacted memory allocated by MeshLink.
+ * and frees the struct meshlink_handle and all associacted memory allocated by MeshLink, including all channels.
* Afterwards, the handle and any pointers to a struct meshlink_node or struct meshlink_channel are invalid.
*
* It is allowed to call this function at any time on a valid handle, except inside callback functions.
*/
extern void meshlink_close(meshlink_handle_t *mesh);
+/// Destroy a MeshLink instance.
+/** This function remove all configuration files of a MeshLink instance. It should only be called when the application
+ * does not have an open handle to this instance. Afterwards, a call to meshlink_open() will create a completely
+ * new instance.
+ *
+ * @param confbase The directory in which MeshLink stores its configuration files.
+ * After the function returns, the application is free to overwrite or free @a confbase @a.
+ *
+ * @return This function will return true if the MeshLink instance was succesfully destroyed, false otherwise.
+ */
+extern bool meshlink_destroy(const char *confbase);
+
/// A callback for receiving data from the mesh.
/** @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.
} meshlink_log_level_t;
/// A callback for receiving log messages generated by MeshLink.
-/** @param mesh A handle which represents an instance of MeshLink.
+/** @param mesh A handle which represents an instance of MeshLink, or NULL.
* @param level An enum describing the severity level of the message.
* @param text A pointer to a nul-terminated C string containing the textual log message.
* This pointer is only valid for the duration of the callback.
/// Set the log callback.
/** This functions sets the callback that is called whenever MeshLink has some information to log.
- * The callback is run in MeshLink's own thread.
+ *
+ * The @a mesh @a parameter can either be a valid MeshLink handle, or NULL.
+ * In case it is NULL, the callback will be called for errors that happen outside the context of a valid mesh instance.
+ * Otherwise, it will be called for errors that happen in the context of the given mesh instance.
+ *
+ * If @a mesh @a is not NULL, then the callback is run in MeshLink's own thread.
* It is 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.
+ * The @a mesh @a parameter can either be a valid MeshLink handle, or NULL.
+ * In case it is NULL, the callback will be called for errors that happen outside the context of a valid mesh instance.
+ * Otherwise, it will be called for errors that happen in the context of the given mesh instance.
+ *
+ * @param mesh A handle which represents an instance of MeshLink, or NULL.
* @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 ssize_t meshlink_get_pmtu(meshlink_handle_t *mesh, meshlink_node_t *destination);
+/// Get a handle for our own node.
+/** This function returns a handle for the local node.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ *
+ * @return A pointer to a meshlink_node_t which represents the local node.
+ * The pointer is guaranteed to be valid until meshlink_close() is called.
+ */
+extern meshlink_node_t *meshlink_get_self(meshlink_handle_t *mesh);
+
/// Get a handle for a specific node.
/** This function returns a handle for the node with the given name.
*
*/
extern meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *name);
+/// Get the fingerprint of a node's public key.
+/** This function returns a fingerprint of the node's public key.
+ * It should be treated as an opaque blob.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param node A pointer to a meshlink_node_t describing the node.
+ *
+ * @return A nul-terminated C string containing the fingerprint of the node's public key in a printable ASCII format.
+ * The application should call free() after it is done using this string.
+ */
+extern char *meshlink_get_fingerprint(meshlink_handle_t *mesh, meshlink_node_t *node);
+
/// Get a list of all nodes.
/** This function returns a list with handles for all known nodes.
*
*/
extern bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, const void *data, size_t len, const void *signature, size_t siglen);
+/// Set the canonical Address for a node.
+/** This function sets the canonical Address for a node.
+ * This address is stored permanently until it is changed by another call to this function,
+ * unlike other addresses associated with a node,
+ * such as those added with meshlink_hint_address() or addresses discovered at runtime.
+ *
+ * If a canonical Address is set for the local node,
+ * it will be used for the hostname part of generated invitation URLs.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param node A pointer to a meshlink_node_t describing the node.
+ * @param address A nul-terminated C string containing the address, which can be either in numeric format or a hostname.
+ * @param port A nul-terminated C string containing the port, which can be either in numeric or symbolic format.
+ * If it is NULL, the listening port's number will be used.
+ *
+ * @return This function returns true if the address was added, false otherwise.
+ */
+extern bool meshlink_set_canonical_address(meshlink_handle_t *mesh, meshlink_node_t *node, const char *address, const char *port);
+
/// Add an Address for the local node.
/** This function adds an Address for the local node, which will be used for invitation URLs.
*
*/
extern bool meshlink_add_address(meshlink_handle_t *mesh, const char *address);
+/// Try to discover the external address for the local node.
+/** This function performs tries to discover the local node's external address
+ * by contacting the meshlink.io server. If a reverse lookup of the address works,
+ * the FQDN associated with the address will be returned.
+ *
+ * Please note that this is function only returns a single address,
+ * even if the local node might have more than one external address.
+ * In that case, there is no control over which address will be selected.
+ * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
+ * there is no guarantee that the external address will be valid for an extended period of time.
+ *
+ * This function is blocking. It can take several seconds before it returns.
+ * There is no guarantee it will be able to resolve the external address.
+ * Failures might be because by temporary network outages.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ *
+ * @return This function returns a pointer to a C string containing the discovered external address,
+ * or NULL if there was an error looking up the address.
+ * After meshlink_get_external_address() returns, the application is free to overwrite or free this string.
+ */
+extern char *meshlink_get_external_address(meshlink_handle_t *mesh);
+
+/// Try to discover the external address for the local node.
+/** This function performs tries to discover the local node's external address
+ * by contacting the meshlink.io server. If a reverse lookup of the address works,
+ * the FQDN associated with the address will be returned.
+ *
+ * Please note that this is function only returns a single address,
+ * even if the local node might have more than one external address.
+ * In that case, there is no control over which address will be selected.
+ * Also note that if you have a dynamic IP address, or are behind carrier-grade NAT,
+ * there is no guarantee that the external address will be valid for an extended period of time.
+ *
+ * This function is blocking. It can take several seconds before it returns.
+ * There is no guarantee it will be able to resolve the external address.
+ * Failures might be because by temporary network outages.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param family The address family to check, for example AF_INET or AF_INET6. If AF_UNSPEC is given,
+ * this might return the external address for any working address family.
+ *
+ * @return This function returns a pointer to a C string containing the discovered external address,
+ * or NULL if there was an error looking up the address.
+ * After meshlink_get_external_address() returns, the application is free to overwrite or free this string.
+ */
+extern char *meshlink_get_external_address_for_family(meshlink_handle_t *mesh, int address_family);
+
+/// Try to discover the external address for the local node, and add it to its list of addresses.
+/** This function is equivalent to:
+ *
+ * meshlink_add_address(mesh, meshlink_get_external_address(mesh));
+ *
+ * Read the description of meshlink_get_external_address() for the limitations of this function.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ *
+ * @return This function returns true if the address was added, false otherwise.
+ */
+extern bool meshlink_add_external_address(meshlink_handle_t *mesh);
+
+/// Get the network port used by the local node.
+/** This function returns the network port that the local node is listening on.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ *
+ * @return This function returns the port number, or -1 in case of an error.
+ */
+extern int meshlink_get_port(meshlink_handle_t *mesh);
+
+/// Set the network port used by the local node.
+/** This function sets the network port that the local node is listening on.
+ * It may only be called when the mesh is not running.
+ * If unsure, call meshlink_stop() before calling this function.
+ * Also note that if your node is already part of a mesh with other nodes,
+ * that the other nodes may no longer be able to initiate connections to the local node,
+ * since they will try to connect to the previously configured port.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param port The port number to listen on. This must be between 0 and 65535.
+ * If the port is set to 0, then MeshLink will listen on a port
+ * that is randomly assigned by the operating system every time meshlink_open() is called.
+ *
+ * @return This function returns true if the port was succesfully changed, false otherwise.
+ */
+
+extern bool meshlink_set_port(meshlink_handle_t *mesh, int port);
+
+/// Set the timeout for invitations.
+/** This function sets the timeout for invitations.
+ * Note that timeouts are only checked at the time a node tries to join using an invitation.
+ * The default timeout for invitations is 1 week.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param timeout The timeout for invitations in seconds.
+ */
+extern void meshlink_set_invitation_timeout(meshlink_handle_t *mesh, int timeout);
+
/// Invite another node into the mesh.
/** This function generates an invitation that can be used by another node to join the same mesh as the local node.
* The generated invitation is a string containing a URL.
* An invitation can only be used if the local node has never connected to other nodes before.
* After a succesfully accepted invitation, the name of the local node may have changed.
*
+ * 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.
+ *
+ * This function is blocking. It can take several seconds before it returns.
+ * There is no guarantee it will perform a successful join.
+ * Failures might be caused by temporary network outages, or by the invitation having expired.
+ *
* @param mesh A handle which represents an instance of MeshLink.
* @param invitation A nul-terminated C string containing the invitation URL.
* After this function returns, the application is free to overwrite or free @a invitation @a.
* and will send data to it and accept any data received from it.
*
* @param mesh A handle which represents an instance of MeshLink.
- * @param node A pointer to a meshlink_node_t describing the node to be blacklisted.
+ * @param node A pointer to a meshlink_node_t describing the node to be whitelisted.
*/
-extern void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node);
+extern void meshlink_whitelist(meshlink_handle_t *mesh, meshlink_node_t *node);
+
+/// Set whether new nodes are blacklisted by default.
+/** This function sets the blacklist behaviour for newly discovered nodes.
+ * If set to true, new nodes will be automatically blacklisted.
+ * If set to false, which is the default, new nodes are automatically whitelisted.
+ * The whitelist/blacklist status of a node may be changed afterwards with the
+ * meshlink_whitelist() and meshlink_blacklist() functions.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param blacklist True if new nodes are to be blacklisted, false if whitelisted.
+ */
+extern void meshlink_set_default_blacklist(meshlink_handle_t *mesh, bool blacklist);
/// A callback for accepting incoming channels.
/** This function is called whenever a remote node wants to open a channel to the local node.
* 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, or NULL in case no data has been received yet. (Not yet used.)
* The pointer is only valid during the lifetime of the callback.
* @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);
+typedef bool (*meshlink_channel_accept_cb_t)(meshlink_handle_t *mesh, meshlink_channel_t *channel, uint16_t port, const void *data, size_t len);
/// A callback for receiving data from a channel.
/** This function is called whenever data is received from a remote node on a channel.
*/
typedef void (*meshlink_channel_receive_cb_t)(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len);
+/// A callback informing the application when data can be sent on a channel.
+/** This function is called whenever there is enough free buffer space so a call to meshlink_channel_send() will succeed.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ * @param len The maximum amount of data that is guaranteed to be accepted by meshlink_channel_send(),
+ * or 0 in case of an error.
+ */
+typedef void (*meshlink_channel_poll_cb_t)(meshlink_handle_t *mesh, meshlink_channel_t *channel, 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.
*/
extern void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_receive_cb_t cb);
+/// Set the poll callback.
+/** This functions sets the callback that is called whenever data can be sent to another 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 pass data to or from 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 data can be sent to another node.
+ * If a NULL pointer is given, the callback will be disabled.
+ */
+extern void meshlink_set_channel_poll_cb(meshlink_handle_t *mesh, meshlink_channel_t *channel, meshlink_channel_poll_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.
+ * The pointer may be NULL, in which case incoming data is ignored.
+ * @param data A pointer to a buffer containing data to already queue for sending, or NULL if there is no data to send.
+ * After meshlink_send() returns, the application is free to overwrite or free this buffer.
+ * @param len The length of the data, or 0 if there is no data to send.
+ * @param flags A bitwise-or'd combination of flags that set the semantics for this channel.
+ *
+ * @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_ex(meshlink_handle_t *mesh, meshlink_node_t *node, uint16_t port, meshlink_channel_receive_cb_t cb, const void *data, size_t len, uint32_t flags);
+
/// 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.
*/
extern ssize_t meshlink_channel_send(meshlink_handle_t *mesh, meshlink_channel_t *channel, const void *data, size_t len);
+/// Get channel flags.
+/** This returns the flags used when opening this channel.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param channel A handle for the channel.
+ *
+ * @return The flags set for this channel.
+ */
+extern uint32_t meshlink_channel_get_flags(meshlink_handle_t *mesh, meshlink_channel_t *channel);
+
+/// Hint that a hostname may be found at an address
+/** This function indicates to meshlink that the given hostname is likely found
+ * at the given IP address and port.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param hostname The hostname which can be found at the given address.
+ * The caller is free to overwrite or free this string
+ * once meshlink returns.
+ * @param addr The IP address and port which should be tried for the
+ * given hostname. The caller is free to overwrite or free
+ * this memory once meshlink returns.
+ */
+extern void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const struct sockaddr *addr);
+
+/// Enable or disable zeroconf discovery of local peers
+
+/** This controls whether zeroconf discovery using the Catta library will be
+ * enabled to search for peers on the local network. By default, it is enabled.
+ *
+ * @param mesh A handle which represents an instance of MeshLink.
+ * @param enable Set to true to enable discovery, false to disable.
+ */
+extern void meshlink_enable_discovery(meshlink_handle_t *mesh, bool enable);
+
#ifdef __cplusplus
}
#endif
-#endif // MESHLINK_H
+#endif