Show how joining an online game goes on the system link list

p2p_join_state tells the menus whether the host is being reached, was
reached (its game is in the list), did not answer, could not be reached
(both routers too strict: allow UPnP) or was lost; the join screen shows
it under the code's status.

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 +2355,16 @@ int p2p_join_code_status(void)
 	return status;
 }
 
+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 +2402,8 @@ 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 +43,19 @@ 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);
 
 /* this machine's identifier, which its XNADDR carries (6 bytes) */
 const unsigned char *p2p_identifier(void);

source/interface/ui_widget.c

@@ -5602,6 +5602,7 @@ 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
 {
@@ -5615,6 +5616,17 @@ 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,
+};
+
 static struct
 {
 	boolean keyboard_launched;
@@ -5723,6 +5735,18 @@ 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);
 	}