presencestate: Allow channel drivers to provide presence state information

This patch adds the ability for channel drivers to supply presence information
in a similar manner to device state. The patch does not provide any channel
driver implementations, but it does provide the core infrastructure necessary
for channel drivers to provide such information.

The core handles multiple providers of presence state information. Ordering
of presence state is as follows:
 INVALID < NOT_SET < AVAILABLE < UNAVAILABLE < CHAT < AWAY < XA < DND

Each provider can trump the previous if it provides a presence state that
supercedes a previous one.

Review: https://reviewboard.asterisk.org/r/4050

ASTERISK-24363 #close
Reported by: Gareth Palmer
patches:
  chan_presencestate-428146.patch uploaded by Gareth Palmer (License 5169)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@429967 65c4cc65-6c06-0410-ace0-fbb531ad65f3

4 files changed, 209 insertions, 58 deletions

diff --git a/include/asterisk/channel.h b/include/asterisk/channel.h
index 45e94ce29..40d87c993 100644
--- a/include/asterisk/channel.h
+++ b/include/asterisk/channel.h
@@ -631,6 +631,7 @@ struct ast_channel_tech {
 	struct ast_channel *(* const requester)(const char *type, struct ast_format_cap *cap, const struct ast_assigned_ids *assignedids, const struct ast_channel *requestor, const char *addr, int *cause);
 
 	int (* const devicestate)(const char *device_number);	/*!< Devicestate call back */
+	int (* const presencestate)(const char *presence_provider, char **subtype, char **message); /*!< Presencestate callback */
 
 	/*!
 	 * \brief Start sending a literal DTMF digit
diff --git a/main/channel.c b/main/channel.c
index 4bf2f61ef..aab8e228c 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -275,7 +275,7 @@ static const char *party_number_plan2str(int plan)
 /*! \brief Show channel types - CLI command */
 static char *handle_cli_core_show_channeltypes(struct ast_cli_entry *e, int cmd, struct ast_cli_args *a)
 {
-#define FORMAT  "%-15.15s  %-40.40s %-12.12s %-12.12s %-12.12s\n"
+#define FORMAT  "%-15.15s  %-40.40s %-13.13s %-13.13s %-13.13s %-13.13s\n"
 	struct chanlist *cl;
 	int count_chan = 0;
 
@@ -294,13 +294,14 @@ static char *handle_cli_core_show_channeltypes(struct ast_cli_entry *e, int cmd,
 	if (a->argc != 3)
 		return CLI_SHOWUSAGE;
 
-	ast_cli(a->fd, FORMAT, "Type", "Description",       "Devicestate", "Indications", "Transfer");
-	ast_cli(a->fd, FORMAT, "-----------", "-----------", "-----------", "-----------", "-----------");
+	ast_cli(a->fd, FORMAT, "Type", "Description", "Devicestate", "Presencestate", "Indications", "Transfer");
+	ast_cli(a->fd, FORMAT, "-------------", "-------------", "-------------", "-------------", "-------------", "-------------");
 
 	AST_RWLIST_RDLOCK(&backends);
 	AST_RWLIST_TRAVERSE(&backends, cl, list) {
 		ast_cli(a->fd, FORMAT, cl->tech->type, cl->tech->description,
 			(cl->tech->devicestate) ? "yes" : "no",
+			(cl->tech->presencestate) ? "yes" : "no",
 			(cl->tech->indicate) ? "yes" : "no",
 			(cl->tech->transfer) ? "yes" : "no");
 		count_chan++;
@@ -375,6 +376,7 @@ static char *handle_cli_core_show_channeltype(struct ast_cli_entry *e, int cmd,
 	ast_cli(a->fd,
 		"-- Info about channel driver: %s --\n"
 		"  Device State: %s\n"
+		"Presence State: %s\n"
 		"    Indication: %s\n"
 		"     Transfer : %s\n"
 		"  Capabilities: %s\n"
@@ -385,6 +387,7 @@ static char *handle_cli_core_show_channeltype(struct ast_cli_entry *e, int cmd,
 		"  Text Support: %s\n",
 		cl->tech->type,
 		(cl->tech->devicestate) ? "yes" : "no",
+		(cl->tech->presencestate) ? "yes" : "no",
 		(cl->tech->indicate) ? "yes" : "no",
 		(cl->tech->transfer) ? "yes" : "no",
 		ast_format_cap_get_names(cl->tech->capabilities, &codec_buf),
@@ -7415,6 +7418,7 @@ static int data_channeltypes_provider_handler(const struct ast_data_search *sear
 		ast_data_add_str(data_type, "name", cl->tech->type);
 		ast_data_add_str(data_type, "description", cl->tech->description);
 		ast_data_add_bool(data_type, "devicestate", cl->tech->devicestate ? 1 : 0);
+		ast_data_add_bool(data_type, "presencestate", cl->tech->presencestate ? 1 : 0);
 		ast_data_add_bool(data_type, "indications", cl->tech->indicate ? 1 : 0);
 		ast_data_add_bool(data_type, "transfer", cl->tech->transfer ? 1 : 0);
 		ast_data_add_bool(data_type, "send_digit_begin", cl->tech->send_digit_begin ? 1 : 0);
diff --git a/main/pbx.c b/main/pbx.c
index b605a9143..267717e48 100644
--- a/main/pbx.c
+++ b/main/pbx.c
@@ -1157,10 +1157,14 @@ static int add_hintdevice(struct ast_hint *hint, const char *devicelist)
 		return -1;
 	}
 	ast_str_set(&str, 0, "%s", devicelist);
-	parse = parse_hint_device(str);
+	parse = ast_str_buffer(str);
 
-	while ((cur = strsep(&parse, "&"))) {
+	/* Spit on '&' and ',' to handle presence hints as well */
+	while ((cur = strsep(&parse, "&,"))) {
 		devicelength = strlen(cur);
+		if (!devicelength) {
+			continue;
+		}
 		device = ao2_t_alloc(sizeof(*device) + devicelength, hintdevice_destroy,
 			"allocating a hintdevice structure");
 		if (!device) {
@@ -11828,10 +11832,12 @@ static int pbx_builtin_sayphonetic(struct ast_channel *chan, const char *data)
 
 static void presence_state_cb(void *unused, struct stasis_subscription *sub, struct stasis_message *msg)
 {
-	struct ast_presence_state_message *presence_state = stasis_message_data(msg);
+	struct ast_presence_state_message *presence_state;
 	struct ast_hint *hint;
 	struct ast_str *hint_app = NULL;
-	struct ao2_iterator hint_iter;
+	struct ast_hintdevice *device;
+	struct ast_hintdevice *cmpdevice;
+	struct ao2_iterator *dev_iter;
 	struct ao2_iterator cb_iter;
 	char context_name[AST_MAX_CONTEXT];
 	char exten_name[AST_MAX_EXTENSION];
@@ -11840,38 +11846,48 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		return;
 	}
 
+	presence_state = stasis_message_data(msg);
+
+	if (ao2_container_count(hintdevices) == 0) {
+		/* There are no hints monitoring devices. */
+		return;
+	}
+
 	hint_app = ast_str_create(1024);
 	if (!hint_app) {
 		return;
 	}
 
 	ast_mutex_lock(&context_merge_lock);/* Hold off ast_merge_contexts_and_delete */
-	hint_iter = ao2_iterator_init(hints, 0);
-	for (; (hint = ao2_iterator_next(&hint_iter)); ao2_cleanup(hint)) {
-		struct ast_state_cb *state_cb;
-		const char *app;
-		char *parse;
-		SCOPED_AO2LOCK(lock, hint);
 
-		if (!hint->exten) {
-			/* The extension has already been destroyed */
-			continue;
-		}
+	cmpdevice = ast_alloca(sizeof(*cmpdevice) + strlen(presence_state->provider));
+	strcpy(cmpdevice->hintdevice, presence_state->provider);
 
-		/* Does this hint monitor the device that changed state? */
-		app = ast_get_extension_app(hint->exten);
-		if (ast_strlen_zero(app)) {
-			/* The hint does not monitor presence at all. */
-			continue;
-		}
+	ast_mutex_lock(&context_merge_lock);/* Hold off ast_merge_contexts_and_delete */
+	dev_iter = ao2_t_callback(hintdevices,
+		OBJ_POINTER | OBJ_MULTIPLE,
+		hintdevice_cmp_multiple,
+		cmpdevice,
+		"find devices in container");
+	if (!dev_iter) {
+		ast_mutex_unlock(&context_merge_lock);
+		ast_free(hint_app);
+		return;
+	}
+
+	for (; (device = ao2_iterator_next(dev_iter)); ao2_t_ref(device, -1, "Next device")) {
+		struct ast_state_cb *state_cb;
 
-		ast_str_set(&hint_app, 0, "%s", app);
-		parse = parse_hint_presence(hint_app);
-		if (ast_strlen_zero(parse)) {
+		if (!device->hint) {
+			/* Should never happen. */
 			continue;
 		}
-		if (strcasecmp(parse, presence_state->provider)) {
-			/* The hint does not monitor the presence provider. */
+		hint = device->hint;
+
+		ao2_lock(hint);
+		if (!hint->exten) {
+			/* The extension has already been destroyed */
+			ao2_unlock(hint);
 			continue;
 		}
 
@@ -11885,6 +11901,7 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		ast_copy_string(exten_name, ast_get_extension_name(hint->exten),
 			sizeof(exten_name));
 		ast_str_set(&hint_app, 0, "%s", ast_get_extension_app(hint->exten));
+		ao2_unlock(hint);
 
 		/* Check to see if update is necessary */
 		if ((hint->last_presence_state == presence_state->state) &&
@@ -11928,7 +11945,7 @@ static void presence_state_cb(void *unused, struct stasis_subscription *sub, str
 		}
 		ao2_iterator_destroy(&cb_iter);
 	}
-	ao2_iterator_destroy(&hint_iter);
+	ao2_iterator_destroy(dev_iter);
 	ast_mutex_unlock(&context_merge_lock);
 
 	ast_free(hint_app);
diff --git a/main/presencestate.c b/main/presencestate.c
index 07df7429d..529979bac 100644
--- a/main/presencestate.c
+++ b/main/presencestate.c
@@ -66,6 +66,7 @@ ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
 #include "asterisk/presencestate.h"
 #include "asterisk/pbx.h"
 #include "asterisk/app.h"
+#include "asterisk/test.h"
 
 /*! \brief Device state strings for printing */
 static const struct {
@@ -146,42 +147,74 @@ static enum ast_presence_state presence_state_cached(const char *presence_provid
 
 static enum ast_presence_state ast_presence_state_helper(const char *presence_provider, char **subtype, char **message, int check_cache)
 {
-	struct presence_state_provider *provider;
-	char *address;
-	char *label = ast_strdupa(presence_provider);
-	int res = AST_PRESENCE_INVALID;
-
-	if (check_cache) {
-		res = presence_state_cached(presence_provider, subtype, message);
-		if (res != AST_PRESENCE_INVALID) {
-			return res;
+	char *labels = ast_strdupa(presence_provider);
+	char *label;
+	enum ast_presence_state state = AST_PRESENCE_INVALID;
+	enum ast_presence_state state_order[] = {
+		[AST_PRESENCE_INVALID]     = 0,
+		[AST_PRESENCE_NOT_SET]     = 1,
+		[AST_PRESENCE_AVAILABLE]   = 2,
+		[AST_PRESENCE_UNAVAILABLE] = 3,
+		[AST_PRESENCE_CHAT]        = 4,
+		[AST_PRESENCE_AWAY]        = 5,
+		[AST_PRESENCE_XA]          = 6,
+		[AST_PRESENCE_DND]         = 7
+	};
+
+	while ((label = strsep(&labels, "&"))) {
+		enum ast_presence_state next_state = AST_PRESENCE_INVALID;
+		char *next_subtype = NULL;
+		char *next_message = NULL;
+
+		if (check_cache) {
+			next_state = presence_state_cached(label, &next_subtype, &next_message);
 		}
-	}
 
-	if ((address = strchr(label, ':'))) {
-		*address = '\0';
-		address++;
-	} else {
-		ast_log(LOG_WARNING, "No label found for presence state provider: %s\n", presence_provider);
-		return res;
-	}
+		if (next_state == AST_PRESENCE_INVALID) {
+			struct presence_state_provider *provider;
+			const struct ast_channel_tech *chan_tech;
+			char *address;
+
+			if ((address = strchr(label, '/'))) {
+				*address++ = '\0';
+
+				if ((chan_tech = ast_get_channel_tech(label)) && chan_tech->presencestate) {
+					next_state = chan_tech->presencestate(address, &next_subtype, &next_message);
+				}
+			} else if ((address = strchr(label, ':'))) {
+				*address++ = '\0';
+
+				AST_RWLIST_RDLOCK(&presence_state_providers);
+				AST_RWLIST_TRAVERSE(&presence_state_providers, provider, list) {
+					ast_debug(5, "Checking provider %s with %s\n", provider->label, label);
+
+					if (!strcasecmp(provider->label, label)) {
+						next_state = provider->callback(address, &next_subtype, &next_message);
+						break;
+					}
+				}
+				AST_RWLIST_UNLOCK(&presence_state_providers);
+
+				if (!provider) {
+					ast_log(LOG_WARNING, "No provider found for label: %s\n", label);
+				}
+			} else {
+				ast_log(LOG_WARNING, "No label found for presence state provider: %s\n", label);
+			}
+		}
 
-	AST_RWLIST_RDLOCK(&presence_state_providers);
-	AST_RWLIST_TRAVERSE(&presence_state_providers, provider, list) {
-		ast_debug(5, "Checking provider %s with %s\n", provider->label, label);
+		if (state_order[next_state] > state_order[state]) {
+			state = next_state;
 
-		if (!strcasecmp(provider->label, label)) {
-			res = provider->callback(address, subtype, message);
-			break;
-		}
-	}
-	AST_RWLIST_UNLOCK(&presence_state_providers);
+			ast_free(*subtype);
+			ast_free(*message);
 
-	if (!provider) {
-		ast_log(LOG_WARNING, "No provider found for label %s\n", label);
+			*subtype = next_subtype;
+			*message = next_message;
+		}
 	}
 
-	return res;
+	return state;
 }
 
 enum ast_presence_state ast_presence_state(const char *presence_provider, char **subtype, char **message)
@@ -354,6 +387,99 @@ static const char *presence_state_get_id(struct stasis_message *msg)
 	return presence_state->provider;
 }
 
+#if defined(TEST_FRAMEWORK)
+
+#define TEST_CATEGORY "/main/presence"
+
+static int presence_test_alice_state = AST_PRESENCE_UNAVAILABLE;
+static int presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;
+
+static int presence_test_presencestate(const char *label, char **subtype, char **message)
+{
+	if (!strcmp(label, "Alice")) {
+		return presence_test_alice_state;
+	} else if (!strcmp(label, "Bob")) {
+		return presence_test_bob_state;
+	} else {
+		return AST_PRESENCE_UNAVAILABLE;
+	}
+}
+
+static struct ast_channel_tech presence_test_tech = {
+	.type = "PresenceTestChannel",
+	.description = "Presence test technology",
+	.presencestate = presence_test_presencestate,
+};
+
+AST_TEST_DEFINE(test_presence_chan)
+{
+	int res = AST_TEST_FAIL;
+	char provider[80];
+	enum ast_presence_state state;
+	char *subtype = NULL, *message = NULL;
+
+	switch (cmd) {
+	case TEST_INIT:
+		info->name = "channel_presence";
+		info->category = TEST_CATEGORY;
+		info->summary = "Channel presence state tests";
+		info->description = "Creates test channel technology and then test the presence state callback";
+		return AST_TEST_NOT_RUN;
+	case TEST_EXECUTE:
+		break;
+	}
+
+	if (ast_channel_register(&presence_test_tech)) {
+		ast_log(LOG_WARNING, "Unable to register channel type '%s'\n", presence_test_tech.type);
+		goto presence_test_cleanup;
+	}
+
+	/* Check Alice's state */
+	snprintf(provider, sizeof(provider), "%s/Alice", presence_test_tech.type);
+
+	presence_test_alice_state = AST_PRESENCE_AVAILABLE;
+	state = ast_presence_state_nocache(provider, &subtype, &message);
+
+	if (state != presence_test_alice_state) {
+		ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
+			provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
+		goto presence_test_cleanup;
+	}
+
+	/* Check Alice's and Bob's state, Alice's should win as DND > AVAILABLE */
+	snprintf(provider, sizeof(provider), "%s/Alice&%s/Bob", presence_test_tech.type, presence_test_tech.type);
+
+	presence_test_alice_state = AST_PRESENCE_DND;
+	presence_test_bob_state = AST_PRESENCE_UNAVAILABLE;
+	state = ast_presence_state_nocache(provider, &subtype, &message);
+
+	if (state != presence_test_alice_state) {
+		ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
+			provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_alice_state));
+		goto presence_test_cleanup;
+        }
+
+	/* Check Alice's and Bob's state, Bob's should now win as AVAILABLE < UNAVAILABLE */
+	presence_test_alice_state = AST_PRESENCE_AVAILABLE;
+	state = ast_presence_state_nocache(provider, &subtype, &message);
+
+	if (state != presence_test_bob_state) {
+		ast_log(LOG_WARNING, "Presence state of '%s' returned '%s' instead of the expected value '%s'\n",
+			provider, ast_presence_state2str(state), ast_presence_state2str(presence_test_bob_state));
+		goto presence_test_cleanup;
+	}
+
+	res = AST_TEST_PASS;
+
+presence_test_cleanup:
+	ast_channel_unregister(&presence_test_tech);
+	ast_free(subtype);
+	ast_free(message);
+
+	return res;
+}
+#endif
+
 static void presence_state_engine_cleanup(void)
 {
 	ao2_cleanup(presence_state_topic_all);
@@ -362,6 +488,7 @@ static void presence_state_engine_cleanup(void)
 	presence_state_cache = NULL;
 	presence_state_topic_cached = stasis_caching_unsubscribe_and_join(presence_state_topic_cached);
 	STASIS_MESSAGE_TYPE_CLEANUP(ast_presence_state_message_type);
+	AST_TEST_UNREGISTER(test_presence_chan);
 }
 
 int ast_presence_state_engine_init(void)
@@ -387,6 +514,8 @@ int ast_presence_state_engine_init(void)
 		return -1;
 	}
 
+	AST_TEST_REGISTER(test_presence_chan);
+
 	return 0;
 }