static void NET_SV_ParseSYN(net_packet_t *packet,
net_client_t *client,
net_addr_t *addr)
{
unsigned int magic;
unsigned int cl_gamemode, cl_gamemission;
unsigned int cl_recording_lowres;
unsigned int cl_drone;
unsigned int is_freedoom;
md5_digest_t deh_md5sum, wad_md5sum;
char *player_name;
char *client_version;
int i;
// read the magic number
if (!NET_ReadInt32(packet, &magic))
{
return;
}
if (magic != NET_MAGIC_NUMBER)
{
// invalid magic number
return;
}
// Check the client version is the same as the server
client_version = NET_ReadString(packet);
if (client_version == NULL)
{
return;
}
if (strcmp(client_version, PACKAGE_STRING) != 0)
{
//!
// @category net
//
// When running a netgame server, ignore version mismatches between
// the server and the client. Using this option may cause game
// desyncs to occur, or differences in protocol may mean the netgame
// will simply not function at all.
//
if (M_CheckParm("-ignoreversion") == 0)
{
NET_SV_SendReject(addr,
"Version mismatch: server version is: "
PACKAGE_STRING);
return;
}
}
// read the game mode and mission
if (!NET_ReadInt16(packet, &cl_gamemode)
|| !NET_ReadInt16(packet, &cl_gamemission)
|| !NET_ReadInt8(packet, &cl_recording_lowres)
|| !NET_ReadInt8(packet, &cl_drone)
|| !NET_ReadMD5Sum(packet, wad_md5sum)
|| !NET_ReadMD5Sum(packet, deh_md5sum)
|| !NET_ReadInt8(packet, &is_freedoom))
{
return;
}
if (!NET_ValidGameMode(cl_gamemode, cl_gamemission))
{
return;
}
// read the player's name
player_name = NET_ReadString(packet);
if (player_name == NULL)
{
return;
}
// received a valid SYN
// not accepting new connections?
if (server_state != SERVER_WAITING_START)
{
NET_SV_SendReject(addr, "Server is not currently accepting connections");
return;
}
// allocate a client slot if there isn't one already
if (client == NULL)
{
// find a slot, or return if none found
for (i=0; i<MAXNETNODES; ++i)
{
if (!clients[i].active)
{
client = &clients[i];
break;
}
}
if (client == NULL)
{
return;
}
}
else
{
// If this is a recently-disconnected client, deactivate
// to allow immediate reconnection
if (client->connection.state == NET_CONN_STATE_DISCONNECTED)
{
client->active = false;
}
}
// New client?
if (!client->active)
{
int num_players;
// Before accepting a new client, check that there is a slot
// free
NET_SV_AssignPlayers();
num_players = NET_SV_NumPlayers();
if ((!cl_drone && num_players >= MAXPLAYERS)
|| NET_SV_NumClients() >= MAXNETNODES)
{
NET_SV_SendReject(addr, "Server is full!");
return;
}
// TODO: Add server option to allow rejecting clients which
// set lowres_turn. This is potentially desirable as the
// presence of such clients affects turning resolution.
// Adopt the game mode and mission of the first connecting client
if (num_players == 0 && !cl_drone)
{
sv_gamemode = cl_gamemode;
sv_gamemission = cl_gamemission;
}
// Save the MD5 checksums
memcpy(client->wad_md5sum, wad_md5sum, sizeof(md5_digest_t));
memcpy(client->deh_md5sum, deh_md5sum, sizeof(md5_digest_t));
client->is_freedoom = is_freedoom;
// Check the connecting client is playing the same game as all
// the other clients
if (cl_gamemode != sv_gamemode || cl_gamemission != sv_gamemission)
{
NET_SV_SendReject(addr, "You are playing the wrong game!");
return;
}
// Activate, initialize connection
NET_SV_InitNewClient(client, addr, player_name);
client->recording_lowres = cl_recording_lowres;
client->drone = cl_drone;
}
if (client->connection.state == NET_CONN_STATE_WAITING_ACK)
{
// force an acknowledgement
client->connection.last_send_time = -1;
}
}
static void NET_SV_ParseSYN(net_packet_t *packet, net_client_t *client,
net_addr_t *addr)
{
unsigned int magic;
net_connect_data_t data;
net_packet_t *reply;
net_protocol_t protocol;
char *player_name;
char *client_version;
int num_players;
int i;
NET_Log("server: processing SYN packet");
// Read the magic number and check it is the expected one.
if (!NET_ReadInt32(packet, &magic))
{
NET_Log("server: error: no magic number for SYN");
return;
}
switch (magic)
{
case NET_MAGIC_NUMBER:
break;
case NET_OLD_MAGIC_NUMBER:
NET_Log("server: error: client using old magic number: %d", magic);
NET_SV_SendReject(addr,
"You are using an old client version that is not supported by "
"this server. This server is running " PACKAGE_STRING ".");
return;
default:
NET_Log("server: error: wrong magic number: %d", magic);
return;
}
// Read the client version string. We actually now only use this when
// sending a reject message, as we only reject if we can't negotiate a
// common protocol (below).
client_version = NET_ReadString(packet);
if (client_version == NULL)
{
NET_Log("server: error: no version from client");
return;
}
// Read the client's list of accepted protocols. Net play between forks
// of Chocolate Doom is accepted provided that they can negotiate a
// common accepted protocol.
protocol = NET_ReadProtocolList(packet);
if (protocol == NET_PROTOCOL_UNKNOWN)
{
char reject_msg[256];
M_snprintf(reject_msg, sizeof(reject_msg),
"Version mismatch: server version is: " PACKAGE_STRING "; "
"client is: %s. No common compatible protocol could be "
"negotiated.", client_version);
NET_SV_SendReject(addr, reject_msg);
NET_Log("server: error: no common protocol");
return;
}
// Read connect data, and check that the game mode/mission are valid
// and the max_players value is in a sensible range.
if (!NET_ReadConnectData(packet, &data))
{
NET_Log("server: error: failed to read connect data");
return;
}
if (!D_ValidGameMode(data.gamemission, data.gamemode)
|| data.max_players > NET_MAXPLAYERS)
{
NET_Log("server: error: invalid connect data, max_players=%d, "
"gamemission=%d, gamemode=%d",
data.max_players, data.gamemission, data.gamemode);
return;
}
// Read the player's name
player_name = NET_ReadString(packet);
if (player_name == NULL)
{
NET_Log("server: error: failed to read player name");
return;
}
// At this point we have received a valid SYN.
// Not accepting new connections?
if (server_state != SERVER_WAITING_LAUNCH)
{
NET_Log("server: error: not in waiting launch state, server_state=%d",
server_state);
NET_SV_SendReject(addr,
"Server is not currently accepting connections");
return;
}
// Before accepting a new client, check that there is a slot free.
NET_SV_AssignPlayers();
num_players = NET_SV_NumPlayers();
if ((!data.drone && num_players >= NET_SV_MaxPlayers())
|| NET_SV_NumClients() >= MAXNETNODES)
{
NET_Log("server: no more players, num_players=%d, max=%d",
num_players, NET_SV_MaxPlayers());
NET_SV_SendReject(addr, "Server is full!");
return;
}
// TODO: Add server option to allow rejecting clients which set
// lowres_turn. This is potentially desirable as the presence of such
// clients affects turning resolution.
// Adopt the game mode and mission of the first connecting client:
if (num_players == 0 && !data.drone)
{
sv_gamemode = data.gamemode;
sv_gamemission = data.gamemission;
NET_Log("server: new game, mode=%d, mission=%d",
sv_gamemode, sv_gamemission);
}
// Check the connecting client is playing the same game as all
// the other clients
if (data.gamemode != sv_gamemode || data.gamemission != sv_gamemission)
{
char msg[128];
NET_Log("server: wrong mode/mission, %d != %d || %d != %d",
data.gamemode, sv_gamemode, data.gamemission, sv_gamemission);
M_snprintf(msg, sizeof(msg),
"Game mismatch: server is %s (%s), client is %s (%s)",
D_GameMissionString(sv_gamemission),
D_GameModeString(sv_gamemode),
D_GameMissionString(data.gamemission),
D_GameModeString(data.gamemode));
NET_SV_SendReject(addr, msg);
return;
}
// Allocate a client slot if there isn't one already
if (client == NULL)
{
// find a slot, or return if none found
for (i=0; i<MAXNETNODES; ++i)
{
if (!clients[i].active)
{
client = &clients[i];
break;
}
}
if (client == NULL)
{
return;
}
}
else
{
// If this is a recently-disconnected client, deactivate
// to allow immediate reconnection
if (client->connection.state == NET_CONN_STATE_DISCONNECTED)
{
client->active = false;
}
}
// Client already connected?
if (client->active)
{
NET_Log("server: client is already initialized (duplicate SYN?)");
return;
}
// Activate, initialize connection
NET_SV_InitNewClient(client, addr, protocol);
// Save the SHA1 checksums and other details.
memcpy(client->wad_sha1sum, data.wad_sha1sum, sizeof(sha1_digest_t));
memcpy(client->deh_sha1sum, data.deh_sha1sum, sizeof(sha1_digest_t));
client->is_freedoom = data.is_freedoom;
client->max_players = data.max_players;
client->name = M_StringDuplicate(player_name);
client->recording_lowres = data.lowres_turn;
client->drone = data.drone;
client->player_class = data.player_class;
// Send a reply back to the client, indicating a successful connection
// and specifying the protocol that will be used for communications.
reply = NET_Conn_NewReliable(&client->connection, NET_PACKET_TYPE_SYN);
NET_WriteString(reply, PACKAGE_STRING);
NET_WriteProtocol(reply, protocol);
}
