List public online games and join them from a panel

A host can make its game public (Y in the lobby, or network.public_game):
it then announces name, map, game type, players and join code every 10 s,
retained, on hcvr/1/g<network version>/<id> through the signalling
brokers, and clears it when it stops. On the system link list, X opens an
online games panel listing the public games heard lately (stale ones
dropped after 45 s) and a row to type a code; A joins by the game's code.
Announcements carry no addresses.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

port/linux/src/p2p.c

@@ -331,6 +331,8 @@ static struct
 	unsigned char join_host_hash[P2P_KEY_HASH_SIZE];
 	unsigned char join_token[P2P_TOKEN_SIZE];
 	unsigned long join_time;
+	/* how the latest join goes, for the menus (p2p_join_state) */
+	int join_state;
 
 	char clipboard[P2P_LINK_SIZE];
 	int has_clipboard;
@@ -840,6 +842,12 @@ static void drop_peer(struct peer *peer, const char *reason)
 	struct retired_session *retired = &p2p.retired[p2p.retired_next++ % MAXIMUM_RETIRED_SESSIONS];
 	int ask_again = p2p.joining && peer->is_host && !memcmp(peer->identifier, p2p.join_host, P2P_IDENTIFIER_SIZE);
 
+	if (peer->is_host && !memcmp(peer->identifier, p2p.join_host, P2P_IDENTIFIER_SIZE) &&
+		p2p.join_state != P2P_JOIN_NONE)
+	{
+		p2p.join_state = peer->connected ? P2P_JOIN_LOST : P2P_JOIN_BLOCKED;
+	}
+
 	platform_log("Internet play: %s %s: %s", peer->is_host ? "host" : "player", peer->name, reason);
 	if (peer->connected)
 	{
@@ -1029,6 +1037,8 @@ static void peer_heard(struct peer *peer, unsigned long address, unsigned short
 			address_text(address, port, text));
 		if (peer->is_host)
 		{
+			if (!memcmp(p2p.join_host, peer->identifier, P2P_IDENTIFIER_SIZE) && p2p.join_state != P2P_JOIN_NONE)
+				p2p.join_state = P2P_JOIN_CONNECTED;
 			if (p2p.joining && !memcmp(p2p.join_host, peer->identifier, P2P_IDENTIFIER_SIZE))
 			{
 				p2p.joining = 0;
@@ -2298,6 +2308,7 @@ static int join_invite(const char *text)
 	memcpy(p2p.join_host_hash, hash, sizeof(hash));
 	memcpy(p2p.join_token, token, sizeof(token));
 	p2p.join_requested = 1;
+	p2p.join_state = P2P_JOIN_REACHING;
 	return 1;
 }
 
@@ -2344,6 +2355,51 @@ int p2p_join_code_status(void)
 	return status;
 }
 
+void p2p_set_public_game(int public_game)
+{
+	pthread_mutex_lock(&p2p_lock);
+	p2p_list_set_public(public_game);
+	pthread_mutex_unlock(&p2p_lock);
+}
+
+int p2p_public_game(void)
+{
+	int result;
+
+	pthread_mutex_lock(&p2p_lock);
+	result = p2p_list_public();
+	pthread_mutex_unlock(&p2p_lock);
+	return result;
+}
+
+void p2p_set_game_description(const char *name, const char *map, const char *mode, int players,
+	int maximum_players)
+{
+	pthread_mutex_lock(&p2p_lock);
+	p2p_list_set_description(name, map, mode, players, maximum_players);
+	pthread_mutex_unlock(&p2p_lock);
+}
+
+int p2p_public_games(struct p2p_public_game *games, int maximum)
+{
+	int count;
+
+	pthread_mutex_lock(&p2p_lock);
+	count = p2p.running ? p2p_list_games(games, maximum) : 0;
+	pthread_mutex_unlock(&p2p_lock);
+	return count;
+}
+
+int p2p_join_state(void)
+{
+	int state;
+
+	pthread_mutex_lock(&p2p_lock);
+	state = p2p.running ? p2p.join_state : P2P_JOIN_NONE;
+	pthread_mutex_unlock(&p2p_lock);
+	return state;
+}
+
 void p2p_join_code_clear_status(void)
 {
 	pthread_mutex_lock(&p2p_lock);
@@ -2381,6 +2437,8 @@ static void update_joining(void)
 	{
 		p2p.joining = 0;
 		p2p_signal_stop_joining();
+		if (p2p.join_state == P2P_JOIN_REACHING)
+			p2p.join_state = P2P_JOIN_NO_ANSWER;
 		platform_log("Internet play: no answer from the invite's host; it may have stopped hosting or quit");
 	}
 }

port/linux/src/p2p.h

@@ -43,6 +43,43 @@ int p2p_join_code(char *text, int size);
 int p2p_join_with_code(const char *typed);
 int p2p_join_code_status(void);
 void p2p_join_code_clear_status(void);
+/* how the latest join of an invite or code goes (the VR port's, for the
+menus): reaching the host, connected (its game is in the system link list),
+or why not */
+enum
+{
+	P2P_JOIN_NONE,
+	P2P_JOIN_REACHING,
+	P2P_JOIN_CONNECTED,
+	P2P_JOIN_NO_ANSWER,
+	P2P_JOIN_BLOCKED,
+	P2P_JOIN_LOST,
+};
+int p2p_join_state(void);
+
+/* Public games (p2p_list.c): the hosted game listed for anyone or not, and
+what it is (the game's server, as it changes); and the games others list,
+joined by their codes (p2p_join_with_code) */
+enum
+{
+	P2P_PUBLIC_NAME_SIZE = 16,
+	P2P_PUBLIC_MAP_SIZE = 32,
+	P2P_PUBLIC_MODE_SIZE = 24,
+};
+struct p2p_public_game
+{
+	char name[P2P_PUBLIC_NAME_SIZE];
+	char map[P2P_PUBLIC_MAP_SIZE];
+	char mode[P2P_PUBLIC_MODE_SIZE];
+	char code[12];
+	int players;
+	int maximum_players;
+};
+void p2p_set_public_game(int public_game);
+int p2p_public_game(void);
+void p2p_set_game_description(const char *name, const char *map, const char *mode, int players,
+	int maximum_players);
+int p2p_public_games(struct p2p_public_game *games, int maximum);
 
 /* this machine's identifier, which its XNADDR carries (6 bytes) */
 const unsigned char *p2p_identifier(void);

port/linux/src/p2p_internal.h

@@ -111,6 +111,9 @@ int p2p_signal_connected(void);
 a message to a topic through every broker */
 void p2p_signal_sync_topics(void);
 void p2p_signal_publish(const char *topic, const unsigned char *payload, int size);
+/* the same, kept by the brokers for whoever listens later (empty: no
+longer) */
+void p2p_signal_publish_retained(const char *topic, const unsigned char *payload, int size);
 
 /* ---------- p2p_code.c: join codes (under p2p_lock) */
 
@@ -136,6 +139,21 @@ void p2p_code_topics(const char **host_topic, const char **look_topic);
 int p2p_code_received(const char *topic, const unsigned char *payload, int size);
 void p2p_code_update(void);
 
+/* ---------- p2p_list.c: public games (under p2p_lock) */
+
+/* hosting: whether the game is listed, and what it is */
+void p2p_list_set_public(int public_game);
+int p2p_list_public(void);
+void p2p_list_set_description(const char *name, const char *map, const char *mode, int players,
+	int maximum_players);
+/* the games listed lately; asking keeps this machine listening a while */
+int p2p_list_games(struct p2p_public_game *games, int maximum);
+/* (p2p_signal.c) the topic to listen on (empty: none); a message on one
+(nonzero if it was a listing's); and each pass, whether hosting */
+const char *p2p_list_topic(void);
+int p2p_list_received(const char *topic, const unsigned char *payload, int size);
+void p2p_list_update(int hosting);
+
 /* ---------- p2p_crypto.c */
 
 enum

port/linux/src/p2p_list.c

@@ -0,0 +1,335 @@
+/*
+P2P_LIST.C
+
+Public games (the VR port's): a host may list its game for anyone, who
+finds it in a list of online games and joins it by its join code
+(p2p_code.c), without a server of this project's.
+
+- A public game's host announces it through the signalling brokers
+  (p2p_signal.c) every ANNOUNCE_INTERVAL, retained, on a topic of its own
+  under hcvr/1/g<network version>/: its name, map, game type, players, its
+  join code, and the time. Retained, a machine that starts listening gets
+  every game's latest at once. A host that stops (it closes its game, or
+  makes it private) clears its topic; one that quits without that leaves
+  its last announcement, which listeners drop once it is older than
+  STALE_SECONDS (by the machines' clocks).
+- A machine that shows the list listens on the topics of its network
+  version (a wildcard), and keeps the games heard of lately.
+- An announcement carries no address: a machine reaches a public game's
+  host only by its code, as anyone given the code does. Anyone can announce
+  anything, so what is shown is checked to be printable and in bounds, and
+  a game that is not what it says is only a code that does not answer.
+*/
+
+#include "platform.h"
+#include "posix.h"
+#include "port_config.h"
+#include "p2p_internal.h"
+#include "halo_port_limits.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+enum
+{
+	ANNOUNCEMENT_VERSION = 1,
+	/* milliseconds */
+	ANNOUNCE_INTERVAL = 10000,
+	/* a listener's interest lapses this long after the menu last asked */
+	WATCH_TIME = 3000,
+	STALE_SECONDS = 45,
+	MAXIMUM_LISTED_GAMES = 32,
+};
+
+/* what goes to the brokers (byte for byte) */
+struct announcement
+{
+	char magic[4];
+	unsigned char version;
+	unsigned char players;
+	unsigned char maximum_players;
+	unsigned char flags;
+	unsigned char time[8];
+	char code[8];
+	char name[P2P_PUBLIC_NAME_SIZE];
+	char map[P2P_PUBLIC_MAP_SIZE];
+	char mode[P2P_PUBLIC_MODE_SIZE];
+};
+
+struct listed_game
+{
+	int used;
+	char topic[P2P_CODE_TOPIC_SIZE];
+	unsigned long heard_time;
+	long long announced_time;
+	struct p2p_public_game game;
+};
+
+static struct
+{
+	/* hosting (whether public: network.public_game, until Y changes it) */
+	int initialized;
+	int public_game;
+	char topic[P2P_CODE_TOPIC_SIZE];
+	int announced;
+	unsigned long announced_time;
+	char name[P2P_PUBLIC_NAME_SIZE];
+	char map[P2P_PUBLIC_MAP_SIZE];
+	char mode[P2P_PUBLIC_MODE_SIZE];
+	int players;
+	int maximum_players;
+
+	/* listening */
+	unsigned long watched_time;
+	int watching;
+	char watch_topic[P2P_CODE_TOPIC_SIZE];
+	struct listed_game games[MAXIMUM_LISTED_GAMES];
+} list;
+
+static int list_elapsed(unsigned long since, unsigned long time)
+{
+	return (unsigned int)(p2p_now() - since) >= (unsigned int)time;
+}
+
+/* text as shown: printable ASCII only, ended */
+static void list_text(char *destination, int size, const char *source, int source_size)
+{
+	int index;
+
+	for (index = 0; index < size - 1 && index < source_size && source[index]; index++)
+		destination[index] = source[index] >= 32 && source[index] < 127 ? source[index] : '?';
+	destination[index] = 0;
+}
+
+static long long list_time_now(void)
+{
+	return (long long)time(NULL);
+}
+
+static void list_topics_make(void)
+{
+	if (!list.topic[0])
+	{
+		unsigned char random[8];
+		char hex[17];
+
+		posix_random_bytes(random, sizeof(random));
+		p2p_hex(random, sizeof(random), hex);
+		snprintf(list.topic, sizeof(list.topic), "hcvr/1/g%d/%s", HALO_PORT_NETWORK_VERSION, hex);
+	}
+	if (!list.watch_topic[0])
+		snprintf(list.watch_topic, sizeof(list.watch_topic), "hcvr/1/g%d/+", HALO_PORT_NETWORK_VERSION);
+}
+
+static void list_announce(void)
+{
+	struct announcement announcement;
+	char code[16];
+	long long now = list_time_now();
+	int index;
+
+	if (!p2p_code_hosted(code, sizeof(code)))
+		return;
+	memset(&announcement, 0, sizeof(announcement));
+	memcpy(announcement.magic, "HCVR", 4);
+	announcement.version = ANNOUNCEMENT_VERSION;
+	announcement.players = (unsigned char)(list.players < 0 ? 0 : list.players > 255 ? 255 : list.players);
+	announcement.maximum_players =
+		(unsigned char)(list.maximum_players < 0 ? 0 : list.maximum_players > 255 ? 255 : list.maximum_players);
+	for (index = 0; index < 8; index++)
+		announcement.time[index] = (unsigned char)(now >> (8 * index));
+	/* (the code without its dash) */
+	memcpy(announcement.code, code, 4);
+	memcpy(announcement.code + 4, code + 5, 4);
+	memcpy(announcement.name, list.name, sizeof(announcement.name));
+	memcpy(announcement.map, list.map, sizeof(announcement.map));
+	memcpy(announcement.mode, list.mode, sizeof(announcement.mode));
+	p2p_signal_publish_retained(list.topic, (const unsigned char *)&announcement, sizeof(announcement));
+	if (!list.announced)
+		platform_log("Internet play: the game is listed as public (%s, %s, %s)", list.name, list.map, list.mode);
+	list.announced = 1;
+	list.announced_time = p2p_now();
+}
+
+static void list_withdraw(void)
+{
+	if (!list.announced)
+		return;
+	p2p_signal_publish_retained(list.topic, NULL, 0);
+	platform_log("Internet play: the game is no longer listed as public");
+	list.announced = 0;
+}
+
+/* ---------- p2p.c's side (under p2p_lock) */
+
+void p2p_list_set_public(int public_game)
+{
+	if (public_game == list.public_game)
+		return;
+	list.public_game = public_game;
+	list_topics_make();
+	if (!public_game)
+		list_withdraw();
+	else
+		list.announced_time = p2p_now() - ANNOUNCE_INTERVAL;
+}
+
+int p2p_list_public(void)
+{
+	return list.public_game;
+}
+
+void p2p_list_set_description(const char *name, const char *map, const char *mode, int players,
+	int maximum_players)
+{
+	int changed = strncmp(list.name, name, sizeof(list.name) - 1) || strncmp(list.map, map, sizeof(list.map) - 1) ||
+		strncmp(list.mode, mode, sizeof(list.mode) - 1) || players != list.players ||
+		maximum_players != list.maximum_players;
+
+	list_text(list.name, sizeof(list.name), name, P2P_PUBLIC_NAME_SIZE);
+	list_text(list.map, sizeof(list.map), map, P2P_PUBLIC_MAP_SIZE);
+	list_text(list.mode, sizeof(list.mode), mode, P2P_PUBLIC_MODE_SIZE);
+	list.players = players;
+	list.maximum_players = maximum_players;
+	/* (a change goes out soon, not at the next interval) */
+	if (changed && list.announced && list_elapsed(list.announced_time, 1000))
+		list.announced_time = p2p_now() - ANNOUNCE_INTERVAL;
+}
+
+int p2p_list_games(struct p2p_public_game *games, int maximum)
+{
+	int count = 0;
+	int index;
+
+	list.watched_time = p2p_now();
+	list.watching = 1;
+	for (index = 0; index < MAXIMUM_LISTED_GAMES && count < maximum; index++)
+	{
+		if (list.games[index].used)
+			games[count++] = list.games[index].game;
+	}
+	return count;
+}
+
+/* ---------- p2p_signal.c's side (under p2p_lock) */
+
+const char *p2p_list_topic(void)
+{
+	return list.watching ? list.watch_topic : "";
+}
+
+int p2p_list_received(const char *topic, const unsigned char *payload, int size)
+{
+	struct announcement announcement;
+	struct listed_game *slot = NULL;
+	long long announced = 0;
+	char code[16];
+	int index;
+
+	if (!list.watch_topic[0] || strncmp(topic, list.watch_topic, strlen(list.watch_topic) - 1))
+		return 0;
+	/* (this machine's own, as the broker echoes it) */
+	if (!strcmp(topic, list.topic))
+		return 1;
+	for (index = 0; index < MAXIMUM_LISTED_GAMES; index++)
+	{
+		if (list.games[index].used && !strcmp(list.games[index].topic, topic))
+			slot = &list.games[index];
+	}
+	if (size != (int)sizeof(announcement))
+	{
+		/* (empty: withdrawn) */
+		if (slot && size == 0)
+			slot->used = 0;
+		return 1;
+	}
+	memcpy(&announcement, payload, sizeof(announcement));
+	if (memcmp(announcement.magic, "HCVR", 4) || announcement.version != ANNOUNCEMENT_VERSION ||
+		!announcement.maximum_players || announcement.players > announcement.maximum_players)
+	{
+		return 1;
+	}
+	for (index = 0; index < 8; index++)
+		announced |= (long long)announcement.time[index] << (8 * index);
+	if (announced < list_time_now() - STALE_SECONDS || announced > list_time_now() + STALE_SECONDS)
+	{
+		if (slot)
+			slot->used = 0;
+		return 1;
+	}
+	snprintf(code, sizeof(code), "%.4s-%.4s", announcement.code, announcement.code + 4);
+	for (index = 0; code[index]; index++)
+	{
+		if (index != 4 && !((code[index] >= '0' && code[index] <= '9') || (code[index] >= 'A' && code[index] <= 'Z')))
+			return 1;
+	}
+	if (!slot)
+	{
+		int oldest = -1;
+
+		for (index = 0; index < MAXIMUM_LISTED_GAMES && !slot; index++)
+		{
+			if (!list.games[index].used)
+				slot = &list.games[index];
+			else if (oldest < 0 || list.games[index].announced_time < list.games[oldest].announced_time)
+				oldest = index;
+		}
+		if (!slot)
+			slot = &list.games[oldest];
+		memset(slot, 0, sizeof(*slot));
+		snprintf(slot->topic, sizeof(slot->topic), "%s", topic);
+	}
+	slot->used = 1;
+	slot->heard_time = p2p_now();
+	slot->announced_time = announced;
+	list_text(slot->game.name, sizeof(slot->game.name), announcement.name, sizeof(announcement.name));
+	list_text(slot->game.map, sizeof(slot->game.map), announcement.map, sizeof(announcement.map));
+	list_text(slot->game.mode, sizeof(slot->game.mode), announcement.mode, sizeof(announcement.mode));
+	snprintf(slot->game.code, sizeof(slot->game.code), "%s", code);
+	slot->game.players = announcement.players;
+	slot->game.maximum_players = announcement.maximum_players;
+	return 1;
+}
+
+void p2p_list_update(int hosting)
+{
+	int index;
+
+	if (!list.initialized)
+	{
+		list.initialized = 1;
+		if (!list.public_game)
+			list.public_game = config_boolean("network.public_game");
+	}
+	list_topics_make();
+	/* hosting a public game: announced every so often; withdrawn when it
+	is not */
+	if (hosting && list.public_game)
+	{
+		p2p_signal_start();
+		if (p2p_signal_connected() && list_elapsed(list.announced_time, ANNOUNCE_INTERVAL))
+			list_announce();
+	}
+	else if (list.announced)
+	{
+		list_withdraw();
+	}
+	/* listening while the menu asks */
+	if (list.watching && list_elapsed(list.watched_time, WATCH_TIME))
+	{
+		list.watching = 0;
+		memset(list.games, 0, sizeof(list.games));
+		p2p_signal_sync_topics();
+	}
+	else if (list.watching)
+	{
+		p2p_signal_start();
+		p2p_signal_sync_topics();
+	}
+	for (index = 0; index < MAXIMUM_LISTED_GAMES; index++)
+	{
+		if (list.games[index].used && list.games[index].announced_time < list_time_now() - STALE_SECONDS)
+			list.games[index].used = 0;
+	}
+}

port/linux/src/p2p_signal.c

@@ -157,6 +157,8 @@ struct broker
 	/* (join codes' topics: p2p_code.c) */
 	char code_host_topic[TOPIC_SIZE];
 	char code_look_topic[TOPIC_SIZE];
+	/* (public games': p2p_list.c) */
+	char list_topic[TOPIC_SIZE];
 	unsigned char input[BUFFER_SIZE];
 	int input_size;
 	unsigned char output[BUFFER_SIZE];
@@ -328,6 +330,7 @@ static void broker_close(struct broker *broker, int failed)
 	broker->join_topic[0] = 0;
 	broker->code_host_topic[0] = 0;
 	broker->code_look_topic[0] = 0;
+	broker->list_topic[0] = 0;
 	if (failed)
 		broker->failures++;
 }
@@ -417,8 +420,8 @@ static void broker_publish(struct broker *broker, const char *topic, const unsig
 /* the topics a ready broker should be subscribed to */
 static void broker_sync_topics(struct broker *broker)
 {
-	const char *wanted[4];
-	char *had[4];
+	const char *wanted[5];
+	char *had[5];
 	int index;
 
 	if (broker->state != _broker_ready)
@@ -426,11 +429,13 @@ static void broker_sync_topics(struct broker *broker)
 	wanted[0] = signalling.hosting ? signalling.host_topic : "";
 	wanted[1] = signalling.joining ? signalling.join_topic : "";
 	p2p_code_topics(&wanted[2], &wanted[3]);
+	wanted[4] = p2p_list_topic();
 	had[0] = broker->host_topic;
 	had[1] = broker->join_topic;
 	had[2] = broker->code_host_topic;
 	had[3] = broker->code_look_topic;
-	for (index = 0; index < 4; index++)
+	had[4] = broker->list_topic;
+	for (index = 0; index < 5; index++)
 	{
 		if (!strcmp(wanted[index], had[index]))
 			continue;
@@ -949,7 +954,7 @@ static void publish_received(struct broker *broker, const char *topic, const uns
 
 	if (size > MAXIMUM_MESSAGE_SIZE + P2P_SEAL_OVERHEAD)
 		return;
-	if (p2p_code_received(topic, payload, size))
+	if (p2p_code_received(topic, payload, size) || p2p_list_received(topic, payload, size))
 		return;
 	if (signalling.hosting && !strcmp(topic, signalling.host_topic))
 	{
@@ -1203,6 +1208,7 @@ void p2p_signal_update(const int *read, int read_count, const int *write, int wr
 	if (signalling.joining && elapsed(signalling.join_sent_time, JOIN_INTERVAL))
 		send_join();
 	p2p_code_update();
+	p2p_list_update(signalling.hosting);
 }
 
 int p2p_signal_connected(void)
@@ -1236,6 +1242,28 @@ void p2p_signal_publish(const char *topic, const unsigned char *payload, int siz
 		publish_everywhere(topic, payload, size);
 }
 
+void p2p_signal_publish_retained(const char *topic, const unsigned char *payload, int size)
+{
+	unsigned char body[2 + TOPIC_SIZE + MAXIMUM_MESSAGE_SIZE];
+	int index;
+
+	if (size > MAXIMUM_MESSAGE_SIZE)
+		return;
+	for (index = 0; index < signalling.broker_count; index++)
+	{
+		struct broker *broker = &signalling.brokers[index];
+		int body_size;
+
+		if (broker->state != _broker_ready)
+			continue;
+		body_size = put_string(body, topic);
+		if (size)
+			memcpy(body + body_size, payload, (size_t)size);
+		/* (PUBLISH, at most once, retained: an empty one clears it) */
+		broker_send(broker, 0x31, body, body_size + size);
+	}
+}
+
 void p2p_signal_host(const unsigned char *token)
 {
 	if (!signalling.has_nonce_key)

port/linux/src/port_config.c

@@ -275,6 +275,9 @@ static const struct config_setting config_settings[] =
 		"clipboard) that lets whoever has it join over the internet; opening a\n"
 		"link (or copying one before switching to the game) joins. Only people\n"
 		"with the invite can join. Off keeps system link to the local network." },
+	{ "network.public_game", _config_boolean, "false", "HALO_NET_PUBLIC_GAME", _environment_value, _platform_all,
+		"Host games as public: listed for anyone among the online games (the\n"
+		"system link screen's X), as Y in a hosted game's lobby makes them." },
 	{ "network.join_from_clipboard", _config_boolean, "true", "HALO_NET_JOIN_FROM_CLIPBOARD", _environment_value,
 		_platform_all,
 		"Join the game of an invite link found on the clipboard when the game\n"

source/interface/ui_widget.c

@@ -5593,15 +5593,18 @@ static boolean ui_mouse_menus_active(
 #ifdef HALO_ANDROID
 /* ---------- join codes (the VR port's)
 
-Internet play's join codes (port/linux/src/p2p_code.c): the host's lobby
-shows its game's code, and on the screen of games to join, X opens the
-keyboard to type one in, which then joins as an invite link does (the game
-shows up in the list once its host is reached). */
+Internet play's join codes (port/linux/src/p2p_code.c) and public games
+(p2p_list.c): the host's lobby shows its game's code, and Y there lists the
+game for anyone or not; on the screen of games to join, X opens a panel of
+the public games and a way to type a code in, either of which then joins as
+an invite link does (the game shows up in the list once its host is
+reached). */
 
 int p2p_join_code(char *text, int size);
 int p2p_join_with_code(char const *typed);
 int p2p_join_code_status(void);
 void p2p_join_code_clear_status(void);
+int p2p_join_state(void);
 
 enum
 {
@@ -5615,12 +5618,74 @@ enum
 	_join_code_offline,
 };
 
+enum
+{
+	/* p2p.h's */
+	_join_state_none,
+	_join_state_reaching,
+	_join_state_connected,
+	_join_state_no_answer,
+	_join_state_blocked,
+	_join_state_lost,
+};
+
+struct ui_public_game
+{
+	/* p2p.h's struct p2p_public_game */
+	char name[16];
+	char map[32];
+	char mode[24];
+	char code[12];
+	int players;
+	int maximum_players;
+};
+
+void p2p_set_public_game(int public_game);
+int p2p_public_game(void);
+int p2p_public_games(struct ui_public_game *games, int maximum);
+
+enum
+{
+	MAXIMUM_SHOWN_PUBLIC_GAMES = 32,
+	/* the online games panel's rows: "enter a code" and the games */
+	ONLINE_PANEL_ROWS = 11,
+};
+
 static struct
 {
 	boolean keyboard_launched;
 	wchar_t typed[12];
+	/* the panel of online games, over the screen of games to join */
+	boolean panel_open;
+	short selection;
+	short scroll;
+	short game_count;
+	struct ui_public_game games[MAXIMUM_SHOWN_PUBLIC_GAMES];
 } ui_join_code_globals;
 
+/* the multiplayer maps' names, as the menus show them */
+static char const *ui_join_code_map_name(
+	char const *map)
+{
+	static char const *const names[][2] = {
+		{ "beavercreek", "Battle Creek" }, { "bloodgulch", "Blood Gulch" }, { "boardingaction", "Boarding Action" },
+		{ "carousel", "Derelict" }, { "chillout", "Chill Out" }, { "damnation", "Damnation" },
+		{ "dangercanyon", "Danger Canyon" }, { "deathisland", "Death Island" }, { "gephyrophobia", "Gephyrophobia" },
+		{ "hangemhigh", "Hang 'Em High" }, { "icefields", "Ice Fields" }, { "infinity", "Infinity" },
+		{ "longest", "Longest" }, { "prisoner", "Prisoner" }, { "putput", "Chiron TL-34" },
+		{ "ratrace", "Rat Race" }, { "sidewinder", "Sidewinder" }, { "timberland", "Timberland" },
+		{ "wizard", "Wizard" },
+	};
+	short index;
+
+	for (index = 0; index < (short)NUMBEROF(names); index++)
+	{
+		if (!strcmp(map, names[index][0]))
+			return names[index][1];
+	}
+	return map;
+}
+
 static boolean ui_join_code_screen_active(
 	char const *name)
 {
@@ -5628,28 +5693,110 @@ static boolean ui_join_code_screen_active(
 		strcmp(widget_globals.active_widgets[0]->name, name) == 0;
 }
 
-/* X on the screen of games to join: the keyboard, for a code (TRUE: the
-event is taken) */
-static boolean ui_join_code_take_event(
-	struct widget_instance *widget,
-	struct event_record const *event)
+static void ui_join_code_launch_keyboard(
+	void)
 {
-	if (event->type != _event_type_button || event->data.button.value != 1 ||
-		event->data.button.index != _gamepad_analog_button_x || widget != widget_globals.active_widgets[0] ||
-		!ui_join_code_screen_active("server_list_screen"))
-	{
-		return FALSE;
-	}
 	ui_join_code_globals.typed[0] = 0;
 	virtual_keyboard_set_caption(L"Enter the join code of an online game");
 	if (!virtual_keyboard_launch(ui_join_code_globals.typed, sizeof(ui_join_code_globals.typed), 8))
 	{
 		virtual_keyboard_set_caption(NULL);
-		return FALSE;
+		return;
 	}
 	p2p_join_code_clear_status();
 	ui_join_code_globals.keyboard_launched = TRUE;
-	return TRUE;
+}
+
+/* the panel's input: the stick or the pad's arrows choose a row, A takes
+it, B closes it */
+static void ui_join_code_panel_event(
+	struct event_record const *event)
+{
+	short rows = (short)(ui_join_code_globals.game_count + 1);
+	short move = 0;
+
+	if (event->type == _event_type_left_stick)
+	{
+		if (event->data.stick.y == SHORT_MAX)
+			move = -1;
+		else if (event->data.stick.y == SHORT_MIN)
+			move = 1;
+	}
+	else if (event->type == _event_type_button && event->data.button.value == 1)
+	{
+		switch (event->data.button.index)
+		{
+		case _gamepad_binary_button_dpad_up: move = -1; break;
+		case _gamepad_binary_button_dpad_down: move = 1; break;
+		case _gamepad_analog_button_b:
+		case _gamepad_binary_button_back:
+			ui_join_code_globals.panel_open = FALSE;
+			break;
+		case _gamepad_analog_button_x:
+			ui_join_code_globals.panel_open = FALSE;
+			ui_join_code_launch_keyboard();
+			break;
+		case _gamepad_analog_button_a:
+		case _gamepad_binary_button_start:
+			ui_join_code_globals.panel_open = FALSE;
+			if (ui_join_code_globals.selection == 0 ||
+				ui_join_code_globals.selection > ui_join_code_globals.game_count)
+			{
+				ui_join_code_launch_keyboard();
+			}
+			else
+			{
+				p2p_join_code_clear_status();
+				p2p_join_with_code(ui_join_code_globals.games[ui_join_code_globals.selection - 1].code);
+			}
+			break;
+		}
+	}
+	if (move)
+	{
+		ui_join_code_globals.selection = (short)PIN(ui_join_code_globals.selection + move, 0, rows - 1);
+		if (ui_join_code_globals.selection < ui_join_code_globals.scroll)
+			ui_join_code_globals.scroll = ui_join_code_globals.selection;
+		else if (ui_join_code_globals.selection >= ui_join_code_globals.scroll + ONLINE_PANEL_ROWS)
+			ui_join_code_globals.scroll = (short)(ui_join_code_globals.selection - ONLINE_PANEL_ROWS + 1);
+	}
+}
+
+/* X on the screen of games to join: the panel of online games (and in it,
+everything); Y in a hosted game's lobby: whether the game is public. TRUE:
+the event is taken. */
+static boolean ui_join_code_take_event(
+	struct widget_instance *widget,
+	struct event_record const *event)
+{
+	if (widget != widget_globals.active_widgets[0])
+		return FALSE;
+	if (ui_join_code_globals.panel_open)
+	{
+		if (!ui_join_code_screen_active("server_list_screen"))
+		{
+			ui_join_code_globals.panel_open = FALSE;
+			return FALSE;
+		}
+		ui_join_code_panel_event(event);
+		return TRUE;
+	}
+	if (event->type != _event_type_button || event->data.button.value != 1)
+		return FALSE;
+	if (event->data.button.index == _gamepad_analog_button_x && ui_join_code_screen_active("server_list_screen"))
+	{
+		ui_join_code_globals.panel_open = TRUE;
+		ui_join_code_globals.selection = 0;
+		ui_join_code_globals.scroll = 0;
+		return TRUE;
+	}
+	if (event->data.button.index == _gamepad_analog_button_y &&
+		ui_join_code_screen_active("connected_pregame_screen") && global_network_game_server_get())
+	{
+		p2p_set_public_game(!p2p_public_game());
+		return TRUE;
+	}
+	return FALSE;
 }
 
 /* the keyboard closed: the code typed, looked up */
@@ -5675,17 +5822,20 @@ static void ui_join_code_update(
 	p2p_join_with_code(text);
 }
 
-static void ui_join_code_draw_line(
+/* text in bounds, left, right or centred (0, 1, 2) */
+static void ui_join_code_draw_text(
+	short x0,
+	short x1,
 	short y0,
 	char const *text,
 	boolean icons,
-	boolean centered)
+	short justification,
+	real_argb_color const *color)
 {
 	rectangle2d bounds;
 	wchar_t wide[96];
 	short index;
 	long font_index = tag_loaded(FONT_GROUP_TAG, "ui\\small_ui");
-	real_argb_color color = { 1.0f, 0.85f, 0.85f, 0.85f };
 
 	if (font_index == NONE)
 		return;
@@ -5694,15 +5844,97 @@ static void ui_join_code_draw_line(
 	wide[index] = 0;
 	bounds.y0 = y0;
 	bounds.y1 = (short)(y0 + 20);
-	bounds.x0 = centered ? 0 : 48;
-	bounds.x1 = centered ? 640 : 600;
-	draw_string_set_draw_mode(font_index, NONE, centered ? 2 : 0, 0, &color);
+	bounds.x0 = x0;
+	bounds.x1 = x1;
+	draw_string_set_draw_mode(font_index, NONE, justification, 0, color);
 	if (icons)
 		draw_string_and_hack_in_icons(&bounds, &bounds, NULL, 0, wide, FALSE);
 	else
 		rasterizer_draw_unicode_string(&bounds, &bounds, NULL, 0, wide);
 }
 
+static void ui_join_code_draw_line(
+	short y0,
+	char const *text,
+	boolean icons,
+	boolean centered)
+{
+	real_argb_color color = { 1.0f, 0.85f, 0.85f, 0.85f };
+
+	ui_join_code_draw_text((short)(centered ? 0 : 48), (short)(centered ? 640 : 600), y0, text, icons,
+		(short)(centered ? 2 : 0), &color);
+}
+
+static void ui_join_code_draw_quad(
+	short x0,
+	short y0,
+	short x1,
+	short y1,
+	unsigned long color)
+{
+	rectangle2d bounds;
+
+	bounds.x0 = x0;
+	bounds.y0 = y0;
+	bounds.x1 = x1;
+	bounds.y1 = y1;
+	draw_quad(&bounds, color);
+}
+
+/* the panel of online games: "enter a code", then the public games */
+static void ui_join_code_render_panel(
+	void)
+{
+	real_argb_color title_color = { 1.0f, 0.55f, 0.75f, 1.0f };
+	real_argb_color text_color = { 1.0f, 0.85f, 0.85f, 0.85f };
+	real_argb_color dim_color = { 1.0f, 0.6f, 0.6f, 0.6f };
+	char line[64];
+	short row;
+
+	ui_join_code_globals.game_count =
+		(short)p2p_public_games(ui_join_code_globals.games, MAXIMUM_SHOWN_PUBLIC_GAMES);
+	ui_join_code_globals.selection =
+		(short)PIN(ui_join_code_globals.selection, 0, ui_join_code_globals.game_count);
+	ui_join_code_draw_quad(40, 72, 600, 410, 0xF0050A18);
+	ui_join_code_draw_quad(40, 72, 600, 74, 0xFF3A6EA5);
+	ui_join_code_draw_quad(40, 408, 600, 410, 0xFF3A6EA5);
+	snprintf(line, sizeof(line), "ONLINE GAMES (%d public)", (int)ui_join_code_globals.game_count);
+	ui_join_code_draw_text(56, 584, 80, line, FALSE, 0, &title_color);
+	ui_join_code_draw_text(56, 216, 104, "Name", FALSE, 0, &dim_color);
+	ui_join_code_draw_text(216, 376, 104, "Map", FALSE, 0, &dim_color);
+	ui_join_code_draw_text(376, 516, 104, "Game", FALSE, 0, &dim_color);
+	ui_join_code_draw_text(516, 584, 104, "Players", FALSE, 1, &dim_color);
+	for (row = 0; row < ONLINE_PANEL_ROWS; row++)
+	{
+		short index = (short)(ui_join_code_globals.scroll + row);
+		short y = (short)(128 + row * 22);
+
+		if (index > ui_join_code_globals.game_count)
+			break;
+		if (index == ui_join_code_globals.selection)
+			ui_join_code_draw_quad(48, y, 592, (short)(y + 21), 0x803A6EA5);
+		if (index == 0)
+		{
+			ui_join_code_draw_text(56, 584, (short)(y + 1), "Enter a join code...", FALSE, 0, &text_color);
+		}
+		else
+		{
+			struct ui_public_game const *game = &ui_join_code_globals.games[index - 1];
+
+			ui_join_code_draw_text(56, 212, (short)(y + 1), game->name, FALSE, 0, &text_color);
+			ui_join_code_draw_text(216, 372, (short)(y + 1), ui_join_code_map_name(game->map), FALSE, 0,
+				&text_color);
+			ui_join_code_draw_text(376, 512, (short)(y + 1), game->mode, FALSE, 0, &text_color);
+			snprintf(line, sizeof(line), "%d/%d", game->players, game->maximum_players);
+			ui_join_code_draw_text(516, 584, (short)(y + 1), line, FALSE, 1, &text_color);
+		}
+	}
+	if (!ui_join_code_globals.game_count)
+		ui_join_code_draw_text(56, 584, 152, "No public games right now", FALSE, 0, &dim_color);
+	ui_join_code_draw_text(56, 584, 384, "%a-button Join   %x-button Enter a code   %b-button Back", TRUE, 0,
+		&text_color);
+}
+
 /* over the screens, as they are drawn */
 static void ui_join_code_render(
 	void)
@@ -5713,7 +5945,12 @@ static void ui_join_code_render(
 	{
 		char const *status = NULL;
 
-		ui_join_code_draw_line(372, "%x-button Join an online game with its code", TRUE, FALSE);
+		if (ui_join_code_globals.panel_open)
+		{
+			ui_join_code_render_panel();
+			return;
+		}
+		ui_join_code_draw_line(372, "%x-button Online games: public ones, or join by a code", TRUE, FALSE);
 		switch (p2p_join_code_status())
 		{
 		case _join_code_looking: status = "Looking for the game of that code..."; break;
@@ -5723,17 +5960,30 @@ static void ui_join_code_render(
 		case _join_code_own: status = "That is this game's own code"; break;
 		case _join_code_offline: status = "Online play is off (network.online in config.toml)"; break;
 		}
+		/* (the code found, or a link: how reaching its host goes) */
+		if (!status || p2p_join_code_status() == _join_code_found)
+		{
+			switch (p2p_join_state())
+			{
+			case _join_state_reaching: status = "Reaching the online game's host..."; break;
+			case _join_state_connected: status = "Connected: the online game is in the list above"; break;
+			case _join_state_no_answer: status = "The host did not answer: it may have stopped hosting"; break;
+			case _join_state_blocked: status = "Blocked by the routers: allow UPnP on yours or the host's"; break;
+			case _join_state_lost: status = "Lost the connection to the online game's host"; break;
+			}
+		}
 		if (status)
 			ui_join_code_draw_line(392, status, FALSE, FALSE);
 	}
 	else if (ui_join_code_screen_active("connected_pregame_screen") && global_network_game_server_get() &&
 		p2p_join_code(code, sizeof(code)))
 	{
-		char line[48];
+		char line[96];
 
-		snprintf(line, sizeof(line), "Online join code: %s", code);
+		snprintf(line, sizeof(line), "Online join code: %s      %%y-button Public game: %s", code,
+			p2p_public_game() ? "Yes" : "No");
 		/* (under the buttons' key) */
-		ui_join_code_draw_line(448, line, FALSE, TRUE);
+		ui_join_code_draw_line(448, line, TRUE, TRUE);
 	}
 }
 

source/networking/network_server_manager.c

@@ -475,6 +475,10 @@ symbols in this file:
 
 /* port: internet play's Discord presence (port/linux/src/p2p.c) */
 void p2p_set_game_player_counts(int count, int maximum);
+#ifdef HALO_ANDROID
+void p2p_set_game_description(char const *name, char const *map, char const *mode, int players,
+	int maximum_players);
+#endif
 
 /* ---------- constants */
 
@@ -1308,6 +1312,42 @@ boolean network_game_server_idle(
 
 	/* (what Discord shows of a game hosted for internet play) */
 	p2p_set_game_player_counts(server->game.player_count, server->game.maximum_players);
+#ifdef HALO_ANDROID
+	/* (and what a public game's listing says: port/linux/src/p2p_list.c) */
+	{
+		char name[16], map[32], mode[24];
+		char const *map_name = server->game.map.name;
+		char const *separator;
+		short index;
+
+		for (index = 0; index < (short)(NUMBEROF(name) - 1) && server->game.name[index]; index++)
+			name[index] = server->game.name[index] < 128 ? (char)server->game.name[index] : '?';
+		name[index] = 0;
+		/* (the scenario's name, the last of its path) */
+		while ((separator = strpbrk(map_name, "\\/")) != NULL)
+			map_name = separator + 1;
+		csstrncpy(map, map_name, sizeof(map) - 1);
+		map[sizeof(map) - 1] = 0;
+		for (index = 0; index < (short)(NUMBEROF(mode) - 1) && index < 12 &&
+			server->game.variant.human_readable_game_description[index]; index++)
+		{
+			wchar_t character = server->game.variant.human_readable_game_description[index];
+
+			mode[index] = character < 128 ? (char)character : '?';
+		}
+		mode[index] = 0;
+		/* (a game type without a name of its own: its kind's) */
+		if (!mode[0])
+		{
+			static char const *const kinds[] = { "", "CTF", "Slayer", "Oddball", "King of the Hill", "Race" };
+			long kind = server->game.variant.game_engine_index;
+
+			csstrncpy(mode, kind > 0 && kind < (long)NUMBEROF(kinds) ? kinds[kind] : "Custom", sizeof(mode) - 1);
+			mode[sizeof(mode) - 1] = 0;
+		}
+		p2p_set_game_description(name, map, mode, server->game.player_count, server->game.maximum_players);
+	}
+#endif
 
 	if (network_game_server_game_is_valid(server))
 	{