Get rid of protocol_exception

Source/dvlnet/abstract_net.h

@@ -14,14 +14,6 @@ namespace devilution::net {
 using buffer_t = std::vector<unsigned char>;
 using provider_t = unsigned long;
 
-class dvlnet_exception : public std::exception {
-public:
-	const char *what() const throw() override
-	{
-		return "Network error";
-	}
-};
-
 class abstract_net {
 public:
 	virtual int create(std::string addrstr) = 0;

Source/dvlnet/base_protocol.h

@@ -64,7 +64,7 @@ private:
 	tl::expected<void, PacketError> recv_ingame(packet &pkt, endpoint_t sender);
 	bool is_recognized(endpoint_t sender);
 
-	bool wait_network();
+	tl::expected<bool, PacketError> wait_network();
 	bool wait_firstpeer();
 	tl::expected<void, PacketError> wait_join();
 };
@@ -80,15 +80,18 @@ plr_t base_protocol<P>::get_master()
 }
 
 template <class P>
-bool base_protocol<P>::wait_network()
+tl::expected<bool, PacketError> base_protocol<P>::wait_network()
 {
 	// wait for ZeroTier for 5 seconds
 	for (auto i = 0; i < 500; ++i) {
-		if (proto.network_online())
-			break;
+		tl::expected<bool, PacketError> status = proto.network_online();
+		if (!status.has_value())
+			return status;
+		if (*status)
+			return true;
 		SDL_Delay(10);
 	}
-	return proto.network_online();
+	return false;
 }
 
 template <class P>
@@ -118,7 +121,12 @@ bool base_protocol<P>::wait_firstpeer()
 template <class P>
 bool base_protocol<P>::send_info_request()
 {
-	if (!proto.network_online())
+	tl::expected<bool, PacketError> status = proto.network_online();
+	if (!status.has_value()) {
+		LogError("network_online: {}", status.error().what());
+		return false;
+	}
+	if (!*status)
 		return false;
 	tl::expected<std::unique_ptr<packet>, PacketError> pkt
 	    = pktfty->make_packet<PT_INFO_REQUEST>(PLR_BROADCAST, PLR_MASTER);
@@ -158,7 +166,12 @@ int base_protocol<P>::create(std::string addrstr)
 	gamename = addrstr;
 	isGameHost_ = true;
 
-	if (wait_network()) {
+	tl::expected<bool, PacketError> isReady = wait_network();
+	if (!isReady.has_value()) {
+		LogError("wait_network: {}", isReady.error().what());
+		return -1;
+	}
+	if (*isReady) {
 		plr_self = 0;
 		if (tl::expected<void, PacketError> result = Connect(plr_self);
 		    !result.has_value()) {
@@ -175,7 +188,13 @@ int base_protocol<P>::join(std::string addrstr)
 	gamename = addrstr;
 	isGameHost_ = false;
 
-	if (wait_network()) {
+	tl::expected<bool, PacketError> isReady = wait_network();
+	if (!isReady.has_value()) {
+		const std::string_view message = isReady.error().what();
+		SDL_SetError("wait_join: %.*s", static_cast<int>(message.size()), message.data());
+		return -1;
+	}
+	if (*isReady) {
 		if (wait_firstpeer()) {
 			tl::expected<void, PacketError> result = wait_join();
 			if (!result.has_value()) {
@@ -413,7 +432,10 @@ tl::expected<void, PacketError> base_protocol<P>::recv_ingame(packet &pkt, endpo
 		tl::expected<const buffer_t *, PacketError> pktInfo = pkt.Info();
 		if (!pktInfo.has_value())
 			return tl::make_unexpected(pktInfo.error());
-		peer.endpoint.unserialize(**pktInfo);
+		if (tl::expected<void, PacketError> result = peer.endpoint.unserialize(**pktInfo);
+		    !result.has_value()) {
+			return result;
+		}
 		peer.sendQueue = std::make_unique<std::deque<packet>>();
 		if (tl::expected<void, PacketError> result = Connect(*newPlayer);
 		    !result.has_value()) {

Source/dvlnet/protocol_zt.cpp

@@ -47,7 +47,7 @@ void protocol_zt::set_reuseaddr(int fd)
 	lwip_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, (void *)&yes, sizeof(yes));
 }
 
-bool protocol_zt::network_online()
+tl::expected<bool, PacketError> protocol_zt::network_online()
 {
 	if (!zerotier_network_ready())
 		return false;
@@ -65,7 +65,7 @@ bool protocol_zt::network_online()
 		if (ret < 0) {
 			Log("lwip, (udp) bind: {}", strerror(errno));
 			SDL_SetError("lwip, (udp) bind: %s", strerror(errno));
-			throw protocol_exception();
+			return tl::make_unexpected(ProtocolError());
 		}
 		set_nonblock(fd_udp);
 	}
@@ -76,13 +76,13 @@ bool protocol_zt::network_online()
 		if (r1 < 0) {
 			Log("lwip, (tcp) bind: {}", strerror(errno));
 			SDL_SetError("lwip, (udp) bind: %s", strerror(errno));
-			throw protocol_exception();
+			return tl::make_unexpected(ProtocolError());
 		}
 		auto r2 = lwip_listen(fd_tcp, 10);
 		if (r2 < 0) {
 			Log("lwip, listen: {}", strerror(errno));
 			SDL_SetError("lwip, listen: %s", strerror(errno));
-			throw protocol_exception();
+			return tl::make_unexpected(ProtocolError());
 		}
 		set_nonblock(fd_tcp);
 		set_nodelay(fd_tcp);
@@ -117,7 +117,7 @@ bool protocol_zt::send_oob_mc(const buffer_t &data) const
 	return send_oob(mc, data);
 }
 
-bool protocol_zt::send_queued_peer(const endpoint &peer)
+tl::expected<bool, PacketError> protocol_zt::send_queued_peer(const endpoint &peer)
 {
 	if (peer_list[peer].fd == -1) {
 		peer_list[peer].fd = lwip_socket(AF_INET6, SOCK_STREAM, 0);
@@ -146,7 +146,7 @@ bool protocol_zt::send_queued_peer(const endpoint &peer)
 		if (decltype(len)(r) == len) {
 			peer_list[peer].send_queue.pop_front();
 		} else {
-			throw protocol_exception();
+			return tl::make_unexpected(ProtocolError());
 		}
 	}
 	return true;
@@ -168,7 +168,12 @@ bool protocol_zt::recv_peer(const endpoint &peer)
 bool protocol_zt::send_queued_all()
 {
 	for (const auto &[endpoint, _] : peer_list) {
-		if (!send_queued_peer(endpoint)) {
+		tl::expected<bool, PacketError> result = send_queued_peer(endpoint);
+		if (!result.has_value()) {
+			LogError("send_queued_peer: {}", result.error().what());
+			continue;
+		}
+		if (!*result) {
 			// handle error?
 		}
 	}

Source/dvlnet/protocol_zt.h

@@ -11,17 +11,15 @@
 #include <string>
 
 #include "dvlnet/frame_queue.h"
+#include "dvlnet/packet.h"
 
 namespace devilution {
 namespace net {
 
-class protocol_exception : public std::exception {
-public:
-	const char *what() const throw() override
-	{
-		return "Protocol error";
-	}
-};
+inline PacketError ProtocolError()
+{
+	return PacketError("Protocol error");
+}
 
 class protocol_zt {
 public:
@@ -55,11 +53,12 @@ public:
 			return buffer_t(addr.begin(), addr.end());
 		}
 
-		void unserialize(const buffer_t &buf)
+		tl::expected<void, PacketError> unserialize(const buffer_t &buf)
 		{
 			if (buf.size() != 16)
-				throw protocol_exception();
+				return tl::make_unexpected(ProtocolError());
 			std::copy(buf.begin(), buf.end(), addr.begin());
+			return {};
 		}
 
 		void from_string(const std::string &str);
@@ -73,7 +72,7 @@ public:
 	bool send_oob_mc(const buffer_t &data) const;
 	bool recv(endpoint &peer, buffer_t &data);
 	bool get_disconnected(endpoint &peer);
-	bool network_online();
+	tl::expected<bool, PacketError> network_online();
 	bool is_peer_connected(endpoint &peer);
 	bool is_peer_relayed(const endpoint &peer) const;
 	static std::string make_default_gamename();
@@ -102,7 +101,7 @@ private:
 	static void set_nodelay(int fd);
 	static void set_reuseaddr(int fd);
 
-	bool send_queued_peer(const endpoint &peer);
+	tl::expected<bool, PacketError> send_queued_peer(const endpoint &peer);
 	bool recv_peer(const endpoint &peer);
 	bool send_queued_all();
 	bool recv_from_peers();