From bc943e8ca08fb36ecfb51f2efd362838b2e3d7ae Mon Sep 17 00:00:00 2001 From: Matthias Wachs Date: Tue, 2 Apr 2013 09:02:07 +0000 Subject: some documentation --- src/ats/gnunet-service-ats_addresses.h | 271 +++++++++++++++++++++++++++++++-- 1 file changed, 256 insertions(+), 15 deletions(-) (limited to 'src') diff --git a/src/ats/gnunet-service-ats_addresses.h b/src/ats/gnunet-service-ats_addresses.h index ddb011fce..82d42a6b1 100644 --- a/src/ats/gnunet-service-ats_addresses.h +++ b/src/ats/gnunet-service-ats_addresses.h @@ -32,6 +32,198 @@ #include "gnunet_statistics_service.h" #include "ats.h" +/** + * NOTE: Do not change this documentation. This documentation is based on + * gnunet.org:/vcs/fsnsg/ats-paper.git/tech-doku/ats-tech-guide.tex + * use build_txt.sh to generate plaintext output + * + * 1 ATS addresses : ATS address management + * + * This ATS addresses ("addresses") component manages the addresses known to + * ATS service and suggests addresses to transport service when it is + * interested in address suggestion for a peer. ATS addresses also + * instantiates the bandwidth assignment mechanism (solver), notifies it + * about changes to addresses and forwards changes to bandwidth assignments + * to transport, depending if transport is interested in this change. + * + * 1.1 Input data + * + * 1.1.1 Addresses + * + * Addresses are added by specifying peer ID, plugin, address, address length + * and session, if available. ATS information can be specified if available. + * + * 1.1.2 Networks + * + * ATS specifies a fix set of networks an address can belong to. For each + * network an inbound and outbound quota will be specified. The available + * networks and addtional helper varaibles are defined in + * gnunet_ats_service.h. At the moment 5 networks are defined: + * * GNUNET_ATS_NET_UNSPECIFIED + * * GNUNET_ATS_NET_LOOPBACK + * * GNUNET_ATS_NET_LAN + * * GNUNET_ATS_NET_WAN + * * GNUNET_ATS_NET_WLAN + * + * The total number of networks defined is stored in + * GNUNET_ATS_NetworkTypeCount GNUNET_ATS_NetworkType can be used array + * initializer for an int array, while GNUNET_ATS_NetworkType is an + * initializer for a char array containing a string description of all + * networks + * + * 1.1.3 Quotas + * + * An inbound and outbound quota for each of the networks mentioned in 1.1.2 + * is loaded from ats configuration during initialization. This quota defines + * to total amount of inbound and outbound traffic allowed for a specific + * network. The configuration values used are in section ats: + * * "NETWORK"_QUOTA_IN = + * * "NETWORK"_QUOTA_IN = + * + * You can specify quotas by setting the to a: + * * unrestricted: unlimited + * * number of bytes: e.g. 10240 + * * fancy value: e.g. 64 Kib + * + * unlimited is defined as GNUNET_ATS_MaxBandwidthString and equivalent to + * the value GNUNET_ATS_MaxBandwidth Important predefined values for quotas + * are: + * * GNUNET_ATS_DefaultBandwidth: 65536 + * * GNUNET_ATS_MaxBandwidth: UINT32_MAX + * * GNUNET_CONSTANTS_DEFAULT_BW_IN_OUT: 1024 + * + * Details of loading quotas and default values will be described on + * + * 1.1.4 Preference values + * + * 1.2 Data structures used + * + * Addresse uses struct ATS_Address for each address. The structs are stored + * in a linked list and provides a pointer void *solver_information for the + * solver to store address specific information. It provides the int values + * active which is set to GNUNET_YES if the address is select for transport + * use and used, representing that transport service is actively using this + * address. Address information are stored in peer, addr, addr_len, plugin. + * + * 1.3 Initialization + * + * During initialization a hashmap to store addresses is created. The quotas + * for all networks defined for ATS are loaded from configuration. For each + * network first the logic will check if the string + * GNUNET_ATS_MaxBandwidthString is configured, if not it will try to convert + * the configured value as a fancy size and if this fails it will try to use + * it as a value_number. If no configuration value is found it will assign + * GNUNET_ATS_DefaultBandwidth. The most important step is to load the + * configured solver using configuration "[ats]:MODE". Current solvers are + * MODE_SIMPLISTIC, MODE_MLP. Interaction is done using a solver API + * + * 1.4 Solver API + * + * Solver functions: + * * s_init: init the solver with required information + * * s_add: add a new address + * * s_update: update ATS values or session for an address + * * s_get: get prefered address for a peer + * * s_del: delete an address + * * s_pref: change preference value for a peer + * * s_done: shutdown solver + * + * Callbacks: addresses provides a bandwidth_changed_cb callback to the + * solver which is called when bandwidth assigned to peer has changed + * + * 1.5 Shutdown + * + * During shutdown all addresses are freed and the solver told to shutdown + * + * 1.6 Addresses and sessions + * + * Addresses consist of the address itself and a numerical session. When a + * new address without a session is added it has no session, so it gets + * session 0 assigned. When an address with a session is added and an address + * object with session 0 is found, this object is updated with the session + * otherwise a new address object with this session assigned is created. + * + * 1.6.1 Terminology + * + * Addresses a1,a2 with session s1, s2 are "exact" if: + * (a1 == a2)&&(s1 == s2) + * Addresses a1,a2 with session s1, s2 are "equivalent" if: + * (a1 == a2)&&((s1 == s2)||(s1 == 0)||(s2 == 0) + * + * 1.7 Address management + * + * Transport service notifies ATS about changes to the addresses known to + * him. + * + * 1.7.1 Adding an address + * + * When transport learns a new address it tells ATS and ATS is telling + * addresses about it using GAS_address_add. If not known to addresses it + * creates a new address object and calls solver's s_add. ATS information are + * deserialized and solver is notified about the session and ATS information + * using s_update. + * + * 1.7.2 Updating an address + * + * Addresses does an lookup up for the existing address with the given + * session. If disassembles included ATS information and notifies the solver + * using s_update about the update. + * + * 1.7.3 Deleting an address + * + * Addresses does an lookup for the exact address and session and if removes + * this address. If session != 0 the session is set to 0 and the address is + * kept. If session == 0, the addresses is removed. + * + * 1.7.4 Requesting an address suggestion + * + * The address client issues a request address message to be notified about + * address suggestions for a specific peer. Addresses asks the solver with + * s_get. If no address is available, it will not send a response, otherwise + * it will respond with the choosen address. + * + * 1.7.5 Address suggestions + * + * Addresses will notify the client automatically on any bandwidth_changed_cb + * by the solver if a address suggestion request is pending. If no address is + * available it will not respond at all If the client is not interested + * anymore, it has to cancel the address suggestion request. + * + * 1.7.6 Suggestions blocks and reset + * + * After suggesting an address it is blocked for ATS_BLOCKING_DELTA sec. to + * prevent the client from being thrashed. If the client requires immediately + * it can reset this block using GAS_addresses_handle_backoff_reset. + * + * 1.7.7 Marking address in use + * + * The client can notify addresses that it successfully uses an address and + * wants this address to be kept by calling GSA_address_in_use. Adresses will + * mark the address as used an notify the solver about the use. + * + * 1.7.8 Address lifecycle + * + * * (add address) + * * (updated address) || (address in use) + * * (delete address) + * + * 1.8 Bandwidth assignment + * + * The addresses are used to perform resource allocation operations. ATS + * addresses takes care of instantiating the solver configured and notifies + * the respective solver about address changes and receives changes to the + * bandwidth assignment from the solver. The current bandwidth assignment is + * sent to transport. The specific solvers will be described in the specific + * section. + * + * 1.9 Changing peer preferences + * + * The bandwidth assigned to a peer can be influenced by setting a preference + * for a peer. The prefernce will be given to to the solver with s_pref which + * has to take care of the preference value + + */ + #define ATS_BLOCKING_DELTA GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 100) struct GAS_Addresses_Handle; @@ -233,10 +425,14 @@ typedef void /** - * Initialize address subsystem. + * Initialize address subsystem. The addresses subsystem manages the addresses + * known and current performance information. It has a solver component + * responsible for the resource allocation. It tells the solver about changes + * and receives updates when the solver changes the ressource allocation. * * @param cfg configuration to use * @param stats the statistics handle to use + * @return an address handle */ struct GAS_Addresses_Handle * GAS_addresses_init (const struct GNUNET_CONFIGURATION_Handle *cfg, @@ -244,22 +440,63 @@ GAS_addresses_init (const struct GNUNET_CONFIGURATION_Handle *cfg, /** * Shutdown address subsystem. + * + * @param the address handle to shutdown */ void GAS_addresses_done (struct GAS_Addresses_Handle *handle); + +/** + * Add a new address for a peer. + * + * @param handle the address handle to use + * @param peer peer + * @param plugin_name transport plugin name + * @param plugin_addr plugin address + * @param plugin_addr_len length of the plugin address + * @param session_id session id, can be 0 + * @param atsi performance information for this address + * @param atsi_count number of performance information contained + */ void -GAS_addresses_handle_backoff_reset (struct GAS_Addresses_Handle *handle, - const struct GNUNET_PeerIdentity *peer); +GAS_addresses_add (struct GAS_Addresses_Handle *handle, + const struct GNUNET_PeerIdentity *peer, + const char *plugin_name, + const void *plugin_addr, + size_t plugin_addr_len, + uint32_t session_id, + const struct GNUNET_ATS_Information *atsi, + uint32_t atsi_count); + /** - * This address is now used or not used anymore + * Notification about active use of an address. + * in_use == GNUNET_YES: + * This address is used to maintain an active connection with a peer. + * in_use == GNUNET_NO: + * This address is no longer used to maintain an active connection with a peer. + * + * Note: can only be called with in_use == GNUNET_NO if called with GNUNET_YES + * before + * + * @param handle the address handle to use + * @param peer peer + * @param plugin_name transport plugin name + * @param plugin_addr plugin address + * @param plugin_addr_len length of the plugin address + * @param session_id session id, can be 0 + * @param in_use GNUNET_YES if GNUNET_NO + * @return GNUNET_SYSERR on failure (address unknown ...) */ int GAS_addresses_in_use (struct GAS_Addresses_Handle *handle, const struct GNUNET_PeerIdentity *peer, - const char *plugin_name, const void *plugin_addr, - size_t plugin_addr_len, uint32_t session_id, int in_use); + const char *plugin_name, + const void *plugin_addr, + size_t plugin_addr_len, + uint32_t session_id, + int in_use); void GAS_addresses_update (struct GAS_Addresses_Handle *handle, @@ -281,6 +518,10 @@ void GAS_addresses_destroy_all (struct GAS_Addresses_Handle *handle); +void +GAS_addresses_request_address (struct GAS_Addresses_Handle *handle, + const struct GNUNET_PeerIdentity *peer); + /** * Cancel address suggestions for a peer * @@ -290,9 +531,16 @@ void GAS_addresses_request_address_cancel (struct GAS_Addresses_Handle *handle, const struct GNUNET_PeerIdentity *peer); + + + +/** + * + */ void -GAS_addresses_request_address (struct GAS_Addresses_Handle *handle, - const struct GNUNET_PeerIdentity *peer); +GAS_addresses_handle_backoff_reset (struct GAS_Addresses_Handle *handle, + const struct GNUNET_PeerIdentity *peer); + void GAS_addresses_change_preference (struct GAS_Addresses_Handle *handle, @@ -301,13 +549,6 @@ GAS_addresses_change_preference (struct GAS_Addresses_Handle *handle, enum GNUNET_ATS_PreferenceKind kind, float score); -void -GAS_addresses_add (struct GAS_Addresses_Handle *handle, - const struct GNUNET_PeerIdentity *peer, - const char *plugin_name, const void *plugin_addr, - size_t plugin_addr_len, uint32_t session_id, - const struct GNUNET_ATS_Information *atsi, - uint32_t atsi_count); typedef void (*GNUNET_ATS_Peer_Iterator) (void *p_it_cls, -- cgit v1.2.3