From 16e4f259c2d8aac42e48a25559ae1f95fe3aa51f Mon Sep 17 00:00:00 2001 From: Mathieu Rene Date: Tue, 28 Jul 2009 20:19:01 +0000 Subject: [PATCH] mod_limit: Refactor and add limit_hash_execute application (see wiki) git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@14401 d0543943-73ff-0310-b7d9-9358b9ac24b2 --- src/mod/applications/mod_limit/mod_limit.c | 268 ++++++++++++++------- 1 file changed, 184 insertions(+), 84 deletions(-) diff --git a/src/mod/applications/mod_limit/mod_limit.c b/src/mod/applications/mod_limit/mod_limit.c index b517beb5a1..a230dc9a1e 100644 --- a/src/mod/applications/mod_limit/mod_limit.c +++ b/src/mod/applications/mod_limit/mod_limit.c @@ -338,8 +338,6 @@ static switch_status_t hash_state_handler(switch_core_session_t *session) switch_hash_this(hi, &key, &keylen, &val); item = (limit_hash_item_t*)val; - - /* We keep the structure even though the count is 0 so we do not allocate too often */ item->total_usage--; switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d\n", (const char*)key, item->total_usage); @@ -861,6 +859,132 @@ end: return SWITCH_STATUS_SUCCESS; } +/* \brief Enforces limit_hash restrictions + * \param session current session + * \param realm limit realm + * \param id limit id + * \param max maximum count + * \param interval interval for rate limiting + * \return SWITCH_TRUE if the access is allowed, SWITCH_FALSE if it isnt + */ +static switch_bool_t do_limit_hash(switch_core_session_t *session, const char *realm, const char *id, int max, int interval) +{ + switch_channel_t *channel = switch_core_session_get_channel(session); + char *hashkey = NULL; + switch_bool_t status = SWITCH_TRUE; + limit_hash_item_t *item = NULL; + time_t now = switch_epoch_time_now(NULL); + limit_hash_private_t *pvt = NULL; + uint8_t increment = 1; + + hashkey = switch_core_session_sprintf(session, "%s_%s", realm, id); + + switch_mutex_lock(globals.limit_hash_mutex); + /* Check if that realm+id has ever been checked */ + if (!(item = (limit_hash_item_t*)switch_core_hash_find(globals.limit_hash, hashkey))) { + /* No, create an empty structure and add it, then continue like as if it existed */ + item = (limit_hash_item_t*)malloc(sizeof(limit_hash_item_t)); + switch_assert(item); + memset(item, 0, sizeof(limit_hash_item_t)); + switch_core_hash_insert(globals.limit_hash, hashkey, item); + } + + /* Did we already run on this channel before? */ + if ((pvt = switch_channel_get_private(channel, "limit_hash"))) + { + /* Yes, but check if we did that realm+id + If we didnt, allow incrementing the counter. + If we did, dont touch it but do the validation anyways + */ + increment = !switch_core_hash_find(pvt->hash, hashkey); + } else { + /* This is the first limit check on this channel, create a hashtable, set our prviate data and add a state handler */ + pvt = (limit_hash_private_t*)switch_core_session_alloc(session, sizeof(limit_hash_private_t)); + memset(pvt, 0, sizeof(limit_hash_private_t)); + switch_core_hash_init(&pvt->hash, switch_core_session_get_pool(session)); + switch_channel_set_private(channel, "limit_hash", pvt); + } + + if (interval > 0) { + if (item->last_check <= (now - interval)) { + item->rate_usage = 1; + item->last_check = now; + } else { + /* Always increment rate when its checked as it doesnt depend on the channel */ + item->rate_usage++; + + if ((max >= 0) && (item->rate_usage > (uint32_t)max)) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s exceeds maximum rate of %d/%ds, now at %d\n", hashkey, max, interval, item->rate_usage); + status = SWITCH_FALSE; + goto end; + } + } + } else if ((max >= 0) && (item->total_usage + increment > (uint32_t)max)) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is already at max value (%d)\n", hashkey, item->total_usage); + status = SWITCH_FALSE; + goto end; + } + + if (increment) { + item->total_usage++; + + switch_core_hash_insert(pvt->hash, hashkey, item); + + if (max == -1) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d\n", hashkey, item->total_usage); + } else if (interval == 0) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d/%d\n", hashkey, item->total_usage, max); + } else { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d/%d for the last %d seconds\n", hashkey, item->rate_usage, max, interval); + } + + limit_fire_event(realm, id, item->total_usage, item->rate_usage, max, max >=0 ? (uint32_t)max : 0); + } + + /* Save current usage & rate into channel variables so it can be used later in the dialplan, or added to CDR records */ + { + const char *susage = switch_core_session_sprintf(session, "%d", item->total_usage); + const char *srate = switch_core_session_sprintf(session, "%d", item->rate_usage); + + switch_channel_set_variable(channel, "limit_usage", susage); + switch_channel_set_variable(channel, switch_core_session_sprintf(session, "limit_usage_%s", hashkey), susage); + + switch_channel_set_variable(channel, "limit_rate", srate); + switch_channel_set_variable(channel, switch_core_session_sprintf(session, "limit_rate_%s", hashkey), srate); + } + + switch_core_event_hook_add_state_change(session, hash_state_handler); + +end: + switch_mutex_unlock(globals.limit_hash_mutex); + return status; +} + +/* !\brief Releases usage of a limit_hash-controlled ressource */ +static void limit_hash_release(switch_core_session_t *session, const char *realm, const char *id) +{ + switch_channel_t *channel = switch_core_session_get_channel(session); + limit_hash_private_t *pvt = switch_channel_get_private(channel, "limit_hash"); + limit_hash_item_t *item = NULL; + char *hashkey = switch_core_session_sprintf(session, "%s_%s", realm, id); + + switch_mutex_lock(globals.limit_hash_mutex); + + item = (limit_hash_item_t*)switch_core_hash_find(pvt->hash, hashkey); + item->total_usage--; + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d\n", (const char*)hashkey, item->total_usage); + + switch_core_hash_delete(pvt->hash, hashkey); + + if (item->total_usage == 0) { + /* Noone is using this item anymore */ + switch_core_hash_delete(globals.limit_hash, (const char*)hashkey); + free(item); + } + + switch_mutex_unlock(globals.limit_hash_mutex); +} + #define LIMITHASH_USAGE " [[/interval]] [number [dialplan [context]]]" #define LIMITHASH_DESC "limit access to a resource and transfer to an extension if the limit is exceeded" SWITCH_STANDARD_APP(limit_hash_function) @@ -870,17 +994,12 @@ SWITCH_STANDARD_APP(limit_hash_function) char *mydata = NULL; char *realm = NULL; char *id = NULL; - char *hashkey = NULL; char *xfer_exten = NULL; int max = -1; int interval = 0; char *szinterval = NULL; - limit_hash_item_t *item = NULL; switch_channel_t *channel = switch_core_session_get_channel(session); - time_t now = switch_epoch_time_now(NULL); - limit_hash_private_t *pvt = NULL; - uint8_t increment = 1; - + /* Parse application data */ if (!switch_strlen_zero(data)) { mydata = switch_core_session_strdup(session, data); @@ -916,97 +1035,77 @@ SWITCH_STANDARD_APP(limit_hash_function) xfer_exten = limit_def_xfer_exten; } - hashkey = switch_core_session_sprintf(session, "%s_%s", realm, id); - - switch_mutex_lock(globals.limit_hash_mutex); - /* Check if that realm+id has ever been checked */ - if (!(item = (limit_hash_item_t*)switch_core_hash_find(globals.limit_hash, hashkey))) { - /* No, create an empty structure and add it, then continue like as if it existed */ - item = (limit_hash_item_t*)malloc(sizeof(limit_hash_item_t)); - switch_assert(item); - memset(item, 0, sizeof(limit_hash_item_t)); - switch_core_hash_insert(globals.limit_hash, hashkey, item); - } - - /* Did we already run on this channel before? */ - if ((pvt = switch_channel_get_private(channel, "limit_hash"))) - { - /* Yes, but check if we did that realm+id - If we didnt, allow incrementing the counter. - If we did, dont touch it but do the validation anyways - */ - increment = !switch_core_hash_find(pvt->hash, hashkey); - } else { - /* This is the first limit check on this channel, create a hashtable, set our prviate data and add a state handler */ - pvt = (limit_hash_private_t*)switch_core_session_alloc(session, sizeof(limit_hash_private_t)); - memset(pvt, 0, sizeof(limit_hash_private_t)); - switch_core_hash_init(&pvt->hash, switch_core_session_get_pool(session)); - switch_channel_set_private(channel, "limit_hash", pvt); - } - - if (interval > 0) { - if (item->last_check <= (now - interval)) { - item->rate_usage = 1; - item->last_check = now; - } else { - /* Always increment rate when its checked as it doesnt depend on the channel */ - item->rate_usage++; - - if ((max >= 0) && (item->rate_usage > (uint32_t)max)) { - switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s exceeds maximum rate of %d/%ds, now at %d\n", hashkey, max, interval, item->rate_usage); - if (*xfer_exten == '!') { - switch_channel_hangup(channel, switch_channel_str2cause(xfer_exten+1)); - } else { - switch_ivr_session_transfer(session, xfer_exten, argv[4], argv[5]); - } - goto end; - } - } - } else if ((max >= 0) && (item->total_usage + increment > (uint32_t)max)) { - switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is already at max value (%d)\n", hashkey, item->total_usage); + if (!do_limit_hash(session, realm, id, max, interval)) { + /* Limit exceeded */ if (*xfer_exten == '!') { switch_channel_hangup(channel, switch_channel_str2cause(xfer_exten+1)); } else { switch_ivr_session_transfer(session, xfer_exten, argv[4], argv[5]); } - goto end; } +} - if (increment) { - item->total_usage++; - - switch_core_hash_insert(pvt->hash, hashkey, item); - - if (max == -1) { - switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d\n", hashkey, item->total_usage); - } else if (interval == 0) { - switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d/%d\n", hashkey, item->total_usage, max); - } else { - switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Usage for %s is now %d/%d for the last %d seconds\n", hashkey, item->rate_usage, max, interval); + +#define LIMITHASHEXECUTE_USAGE " [[/interval]] [number [dialplan [context]]]" +#define LIMITHASHEXECUTE_DESC "limit access to a resource. the specified application will only be executed if the resource is available" +SWITCH_STANDARD_APP(limit_hash_execute_function) +{ + int argc = 0; + char *argv[6] = { 0 }; + char *mydata = NULL; + char *realm = NULL; + char *id = NULL; + char *app = NULL; + char *app_arg = NULL; + int max = -1; + int interval = 0; + char *szinterval = NULL; + + /* Parse application data */ + if (!switch_strlen_zero(data)) { + mydata = switch_core_session_strdup(session, data); + argc = switch_separate_string(mydata, ' ', argv, (sizeof(argv) / sizeof(argv[0]))); + } + + if (argc < 2) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "USAGE: limit_hash_execute %s\n", LIMITHASHEXECUTE_USAGE); + return; + } + + realm = argv[0]; + id = argv[1]; + + /* If max is omitted, only act as a counter and skip maximum checks */ + if (argc > 2) { + if ((szinterval = strchr(argv[2], '/'))) + { + *szinterval++ = '\0'; + interval = atoi(szinterval); } - limit_fire_event(realm, id, item->total_usage, item->rate_usage, max, max >=0 ? (uint32_t)max : 0); - } - - /* Save current usage & rate into channel variables so it can be used later in the dialplan, or added to CDR records */ - { - const char *susage = switch_core_session_sprintf(session, "%d", item->total_usage); - const char *srate = switch_core_session_sprintf(session, "%d", item->rate_usage); + max = atoi(argv[2]); - switch_channel_set_variable(channel, "limit_usage", susage); - switch_channel_set_variable(channel, switch_core_session_sprintf(session, "limit_usage_%s", hashkey), susage); - - switch_channel_set_variable(channel, "limit_rate", srate); - switch_channel_set_variable(channel, switch_core_session_sprintf(session, "limit_rate_%s", hashkey), srate); + if (max < 0) { + max = 0; + } } - switch_core_event_hook_add_state_change(session, hash_state_handler); - -end: - switch_mutex_unlock(globals.limit_hash_mutex); + app = argv[3]; + app_arg = argv[4]; + + if (switch_strlen_zero(app)) { + switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Missing application\n"); + return; + } + + if (do_limit_hash(session, realm, id, max, interval)) { + switch_core_session_execute_application(session, app, app_arg); + limit_hash_release(session, realm, id); + } } + #define LIMIT_HASH_USAGE_USAGE " " SWITCH_STANDARD_API(limit_hash_usage_function) { @@ -1080,6 +1179,7 @@ SWITCH_MODULE_LOAD_FUNCTION(mod_limit_load) SWITCH_ADD_APP(app_interface, "limit", "Limit", LIMIT_DESC, limit_function, LIMIT_USAGE, SAF_SUPPORT_NOMEDIA); SWITCH_ADD_APP(app_interface, "limit_hash", "Limit (hash)", LIMITHASH_DESC, limit_hash_function, LIMITHASH_USAGE, SAF_SUPPORT_NOMEDIA); + SWITCH_ADD_APP(app_interface, "limit_hash_execute", "Limit (hash)", LIMITHASHEXECUTE_USAGE, limit_hash_execute_function, LIMITHASHEXECUTE_USAGE, SAF_SUPPORT_NOMEDIA); SWITCH_ADD_APP(app_interface, "db", "Insert to the db", DB_DESC, db_function, DB_USAGE, SAF_SUPPORT_NOMEDIA); SWITCH_ADD_APP(app_interface, "hash", "Insert into the hashtable", HASH_DESC, hash_function, HASH_USAGE, SAF_SUPPORT_NOMEDIA) SWITCH_ADD_APP(app_interface, "group", "Manage a group", GROUP_DESC, group_function, GROUP_USAGE, SAF_SUPPORT_NOMEDIA);