+#ifndef MESHLINK_H
+#define MESHLINK_H
+
/*
meshlink.h -- MeshLink API
- Copyright (C) 2014 Guus Sliepen <guus@meshlink.io>
+ Copyright (C) 2014-2018 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>
#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 (64)
+#define MESHLINK_FINGERPRINTLEN (64ul)
/// 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 edge.
-typedef struct meshlink_edge meshlink_edge_t;
-
/// A handle for a MeshLink channel.
typedef struct meshlink_channel meshlink_channel_t;
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_ENOTSUP, ///< The operation is not supported in the current configuration of MeshLink
} meshlink_errno_t;
/// Device class
_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 {
- char *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.
+ 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 {
- 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 *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.
+ 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
-/// An edge in the meshlink network.
-struct meshlink_edge {
- struct meshlink_node *from; ///< Pointer to a node. Node memory is
- // owned by meshlink and should not be
- // deallocated. Node contents may be
- // changed by meshlink.
- struct meshlink_node *to; ///< Pointer to a node. Node memory is
- // owned by meshlink and should not be
- // deallocated. Node contents may be
- // changed by meshlink.
- struct sockaddr_storage address;///< The address information associated
- // with this edge.
- uint32_t options; ///< Edge options. @TODO what are edge options?
- int weight; ///< Weight assigned to this edge.
-};
-
/// Get the text for the given MeshLink error code.
/** This function returns a pointer to the string containing the description of the given error code.
*
* @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, const char* appname, dev_class_t devclass);
+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
*/
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.
*
* @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().
+ * @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);
*/
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.
*/
extern void meshlink_hint_address(meshlink_handle_t *mesh, meshlink_node_t *node, const struct sockaddr *addr);
-/// Get a list of edges.
-/** This function returns an array with copies of all known bidirectional edges.
- * The edges are copied to capture the mesh state at call time, since edges
- * mutate frequently. The nodes pointed to within the meshlink_edge_t type
- * are not copies; these are the same pointers that one would get from a call
- * to meshlink_get_all_nodes().
+/// 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 edges A pointer to a previously allocated array of pointers to
- * meshlink_edge_t, or NULL in which case MeshLink will
- * allocate a new array. The application CANNOT supply an
- * array it allocated itself with malloc, but CAN use
- * the return value from the previous call to this function
- * (which is the preferred way).
- * The pointers in the array are valid until meshlink_close() is called.
- * ATTENTION: The pointers and values should never be modified
- * by the application!!!
- * @param nmemb A pointer to a variable holding the number of nodes that
- * are stored in the array. In case the @a nodes @a
- * argument is not NULL, MeshLink might call realloc()
- * on the array to change its size.
- * The contents of this variable will be changed to reflect
- * the new size of the array.
- * @return A pointer to an array containing pointers to all known
- * edges, or NULL in case of an error.
- * If the @a edges @a argument was not NULL, then the
- * retun value can be either the same value or a different
- * value. If the new values is NULL, then the old array
- * will have been freed by Meshlink.
- * The caller must call free() on each element of this
- * array (but not the contents of said elements),
- * as well as the array itself when it is finished.
- * ATTENTION: The pointers and values should never be modified
- * by the application!!!
- */
-extern meshlink_edge_t **meshlink_get_all_edges_state(meshlink_handle_t *mesh, meshlink_edge_t **edges, size_t *nmemb);
+ * @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
projects / meshlink / blobdiff