X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fmeshlink.h;h=2f2e7f841054e2ea3d21622c09906bb881d95970;hp=5777301aebdf58fe9bb599f43a26727d3fa2dff3;hb=92283d7342fabd882126a892b2636d57ff0458de;hpb=0d237f8c1b3a1ddf57c81a1fda2e66892915aee7 diff --git a/src/meshlink.h b/src/meshlink.h index 5777301a..2f2e7f84 100644 --- a/src/meshlink.h +++ b/src/meshlink.h @@ -1,6 +1,9 @@ +#ifndef MESHLINK_H +#define MESHLINK_H + /* meshlink.h -- MeshLink API - Copyright (C) 2014 Guus Sliepen + Copyright (C) 2014-2018 Guus Sliepen 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 @@ -17,16 +20,13 @@ 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#ifndef MESHLINK_H -#define MESHLINK_H - #include #include #include #include #if defined(_WIN32) -#include +#include #else #include #include @@ -37,10 +37,10 @@ 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 (64) +#define MESHLINK_FINGERPRINTLEN (64ul) /// A handle for an instance of MeshLink. typedef struct meshlink_handle meshlink_handle_t; @@ -48,24 +48,23 @@ 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; /// 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_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_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_ENOTSUP, ///< The operation is not supported in the current configuration of MeshLink + MESHLINK_EBUSY, ///< The MeshLink instance is already in use by another process } meshlink_errno_t; /// Device class @@ -77,6 +76,14 @@ typedef enum { _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. @@ -88,38 +95,22 @@ extern __thread meshlink_errno_t meshlink_errno; #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. * @@ -158,10 +149,7 @@ extern const char *meshlink_strerror(meshlink_errno_t err); * @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); - -/// is used by the C++ wrapper to allocate more memory behind the handle -extern meshlink_handle_t *meshlink_open_with_size(const char *confbase, const char *name, const char* appname, dev_class_t devclass, size_t size); +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 @@ -199,6 +187,18 @@ extern void meshlink_stop(meshlink_handle_t *mesh); */ 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. @@ -243,6 +243,26 @@ typedef void (*meshlink_node_status_cb_t)(meshlink_handle_t *mesh, meshlink_node */ extern void meshlink_set_node_status_cb(meshlink_handle_t *mesh, meshlink_node_status_cb_t cb); +/// A callback reporting duplicate node detection. +/** @param mesh A handle which represents an instance of MeshLink. + * @param node A pointer to a meshlink_node_t describing the node which is duplicate. + * This pointer is valid until meshlink_close() is called. + */ +typedef void (*meshlink_node_duplicate_cb_t)(meshlink_handle_t *mesh, meshlink_node_t *node); + +/// Set the node duplicate callback. +/** This functions sets the callback that is called whenever a duplicate node is detected. + * 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 cb A pointer to the function which will be called when a duplicate node is detected. + * If a NULL pointer is given, the callback will be disabled. + */ +extern void meshlink_set_node_duplicate_cb(meshlink_handle_t *mesh, meshlink_node_duplicate_cb_t cb); + /// Severity of log messages generated by MeshLink. typedef enum { MESHLINK_DEBUG, ///< Internal debugging messages. Only useful during application development. @@ -320,6 +340,16 @@ extern bool meshlink_send(meshlink_handle_t *mesh, meshlink_node_t *destination, */ 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. * @@ -340,7 +370,7 @@ extern meshlink_node_t *meshlink_get_node(meshlink_handle_t *mesh, const char *n * @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. + * @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); @@ -395,6 +425,25 @@ extern bool meshlink_sign(meshlink_handle_t *mesh, const void *data, size_t len, */ 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. * @@ -405,6 +454,104 @@ extern bool meshlink_verify(meshlink_handle_t *mesh, meshlink_node_t *source, co */ 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. @@ -425,6 +572,12 @@ extern char *meshlink_invite(meshlink_handle_t *mesh, const char *name); * 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. @@ -479,9 +632,21 @@ extern void meshlink_blacklist(meshlink_handle_t *mesh, meshlink_node_t *node); * 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. @@ -530,7 +695,8 @@ typedef void (*meshlink_channel_receive_cb_t)(meshlink_handle_t *mesh, meshlink_ * * @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); @@ -577,6 +743,29 @@ extern void meshlink_set_channel_receive_cb(meshlink_handle_t *mesh, meshlink_ch */ 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. @@ -639,59 +828,42 @@ extern void meshlink_channel_close(meshlink_handle_t *mesh, meshlink_channel_t * */ 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. + * @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); -/// 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