/* copyright (c) 2007 magnus auvinen, see licence.txt for more info */ #include #include #include "e_system.h" #include "e_config.h" #include "e_network.h" /* header (6 bytes) unsigned char flags; 1 unsigned char seq_ack[3]; 4 unsigned char token[2]; 6 */ enum { NETWORK_VERSION = 1, NETWORK_HEADER_SIZE = 6, NETWORK_MAX_PAYLOAD = 1024, NETWORK_MAX_PACKET_SIZE = NETWORK_HEADER_SIZE+NETWORK_MAX_PAYLOAD, NETWORK_MAX_CLIENTS = 16, NETWORK_CONNSTATE_OFFLINE=0, NETWORK_CONNSTATE_CONNECT=1, NETWORK_CONNSTATE_CONNECTACCEPTED=2, NETWORK_CONNSTATE_ONLINE=3, NETWORK_CONNSTATE_ERROR=4, NETWORK_PACKETFLAG_CONNECT=0x01, NETWORK_PACKETFLAG_ACCEPT=0x02, NETWORK_PACKETFLAG_CLOSE=0x04, NETWORK_PACKETFLAG_VITAL=0x08, NETWORK_PACKETFLAG_RESEND=0x10, NETWORK_PACKETFLAG_CONNLESS=0x20, NETWORK_MAX_SEQACK=0x1000 }; static int current_token = 1; typedef struct { unsigned char ID[2]; unsigned char version; unsigned char flags; unsigned short seq; unsigned short ack; unsigned crc; int token; unsigned data_size; int64 first_send_time; unsigned char *data; } NETPACKETDATA; static void send_packet(NETSOCKET socket, NETADDR4 *addr, NETPACKETDATA *packet) { unsigned char buffer[NETWORK_MAX_PACKET_SIZE]; int send_size = NETWORK_HEADER_SIZE+packet->data_size; buffer[0] = packet->flags; buffer[1] = ((packet->seq>>4)&0xf0) | ((packet->ack>>8)&0x0f); buffer[2] = packet->seq; buffer[3] = packet->ack; buffer[4] = packet->token>>8; buffer[5] = packet->token&0xff; mem_copy(buffer+NETWORK_HEADER_SIZE, packet->data, packet->data_size); net_udp4_send(socket, addr, buffer, send_size); } typedef struct RINGBUFFER_ITEM_t { struct RINGBUFFER_ITEM_t *next; struct RINGBUFFER_ITEM_t *prev; int size; } RINGBUFFER_ITEM; typedef struct { RINGBUFFER_ITEM *first; RINGBUFFER_ITEM *last; unsigned buffer_size; } RINGBUFFER; static void rb_init(RINGBUFFER *rb) { rb->first = 0; rb->last = 0; rb->buffer_size = 0; } static void *rb_item_data(RINGBUFFER_ITEM *item) { return (void*)(item+1); } static void *rb_alloc(RINGBUFFER *rb, int size) { RINGBUFFER_ITEM *item = (RINGBUFFER_ITEM*)mem_alloc(sizeof(RINGBUFFER_ITEM)+size, 1); item->size = size; item->prev = rb->last; item->next = 0; if(rb->last) rb->last->next = item; else rb->first = item; rb->last = item; rb->buffer_size += size; return rb_item_data(item); } static void rb_pop_first(RINGBUFFER *rb) { if(rb->first) { RINGBUFFER_ITEM *next = rb->first->next; rb->buffer_size -= rb->first->size; mem_free(rb->first); rb->first = next; if(rb->first) rb->first->prev = NULL; else rb->last = NULL; } } static void rb_clear(RINGBUFFER *rb) { while(rb->first) rb_pop_first(rb); } typedef struct { unsigned short seq; unsigned short ack; unsigned state; int token; int remote_closed; int connected; int disconnected; RINGBUFFER buffer; int64 last_update_time; int64 last_recv_time; int64 last_send_time; char error_string[256]; NETADDR4 peeraddr; NETSOCKET socket; NETSTATS stats; } NETCONNECTION; typedef struct { NETCONNECTION conn; } NETSLOT; struct NETSERVER_t { NETSOCKET socket; NETSLOT slots[NETWORK_MAX_CLIENTS]; int max_clients; NETFUNC_NEWCLIENT new_client; NETFUNC_NEWCLIENT del_client; void *user_ptr; unsigned char recv_buffer[NETWORK_MAX_PACKET_SIZE]; } ; struct NETCLIENT_t { NETADDR4 server_addr; NETSOCKET socket; unsigned char recv_buffer[NETWORK_MAX_PACKET_SIZE]; NETCONNECTION conn; }; static void conn_reset_stats(NETCONNECTION *conn) { mem_zero(&conn->stats, sizeof(conn->stats)); } static void conn_reset(NETCONNECTION *conn) { conn->seq = 0; conn->ack = 0; conn->remote_closed = 0; if(conn->state == NETWORK_CONNSTATE_ONLINE || conn->state == NETWORK_CONNSTATE_ERROR) { conn->disconnected++; } conn->state = NETWORK_CONNSTATE_OFFLINE; conn->last_send_time = 0; conn->last_recv_time = 0; conn->last_update_time = 0; conn->token = -1; rb_clear(&conn->buffer); } static const char *conn_error(NETCONNECTION *conn) { return conn->error_string; } static void conn_set_error(NETCONNECTION *conn, const char *str) { strcpy(conn->error_string, str); } /* static int conn_state(NETCONNECTION *conn) { return conn->state; }*/ static void conn_init(NETCONNECTION *conn, NETSOCKET socket) { conn_reset(conn); conn_reset_stats(conn); conn->socket = socket; conn->connected = 0; conn->disconnected = 0; rb_init(&conn->buffer); mem_zero(conn->error_string, sizeof(conn->error_string)); } static void conn_ack(NETCONNECTION *conn, int ack) { while(1) { RINGBUFFER_ITEM *item = conn->buffer.first; NETPACKETDATA *resend; if(!item) break; resend = (NETPACKETDATA *)rb_item_data(item); if(resend->seq <= ack || (ack < NETWORK_MAX_SEQACK/3 && resend->seq > NETWORK_MAX_SEQACK/2)) rb_pop_first(&conn->buffer); else break; } } static void conn_send_raw(NETCONNECTION *conn, NETPACKETDATA *data) { conn->last_send_time = time_get(); conn->stats.send_packets++; conn->stats.send_bytes += data->data_size + NETWORK_HEADER_SIZE; send_packet(conn->socket, &conn->peeraddr, data); } static void conn_resend(NETCONNECTION *conn) { RINGBUFFER_ITEM *item = conn->buffer.first; while(item) { NETPACKETDATA *resend = (NETPACKETDATA *)rb_item_data(item); conn->stats.resend_packets++; conn->stats.resend_bytes += resend->data_size + NETWORK_HEADER_SIZE; conn_send_raw(conn, resend); item = item->next; } } static void conn_send(NETCONNECTION *conn, int flags, int data_size, const void *data) { NETPACKETDATA p; if(flags&NETWORK_PACKETFLAG_VITAL) conn->seq = (conn->seq+1)%NETWORK_MAX_SEQACK; p.ID[0] = 'T'; p.ID[1] = 'W'; p.version = NETWORK_VERSION; p.flags = flags; p.seq = conn->seq; p.ack = conn->ack; p.crc = 0; p.token = conn->token; p.data_size = data_size; p.data = (unsigned char *)data; p.first_send_time = time_get(); if(flags&NETWORK_PACKETFLAG_VITAL) { /* save packet if we need to resend */ NETPACKETDATA *resend = (NETPACKETDATA *)rb_alloc(&conn->buffer, sizeof(NETPACKETDATA)+data_size); *resend = p; resend->data = (unsigned char *)(resend+1); mem_copy(resend->data, p.data, p.data_size); } /* TODO: calc crc */ conn_send_raw(conn, &p); } static int conn_connect(NETCONNECTION *conn, NETADDR4 *addr) { if(conn->state != NETWORK_CONNSTATE_OFFLINE) return -1; /* init connection */ conn_reset(conn); conn->peeraddr = *addr; conn->token = current_token++; mem_zero(conn->error_string, sizeof(conn->error_string)); conn->state = NETWORK_CONNSTATE_CONNECT; conn_send(conn, NETWORK_PACKETFLAG_CONNECT, 0, 0); return 0; } static void conn_disconnect(NETCONNECTION *conn, const char *reason) { if(conn->remote_closed == 0) { if(reason) conn_send(conn, NETWORK_PACKETFLAG_CLOSE, strlen(reason)+1, reason); else conn_send(conn, NETWORK_PACKETFLAG_CLOSE, 0, 0); conn->error_string[0] = 0; if(reason) strcpy(conn->error_string, reason); } conn_reset(conn); } static int conn_feed(NETCONNECTION *conn, NETPACKETDATA *p, NETADDR4 *addr) { int64 now = time_get(); conn->last_recv_time = now; conn->stats.recv_packets++; conn->stats.recv_bytes += p->data_size + NETWORK_HEADER_SIZE; if(p->flags&NETWORK_PACKETFLAG_CLOSE) { conn->state = NETWORK_CONNSTATE_ERROR; conn->remote_closed = 1; if(p->data_size) conn_set_error(conn, (char *)p->data); else conn_set_error(conn, "no reason given"); if(config.debug) dbg_msg("conn", "closed reason='%s'", conn_error(conn)); return 0; } if(conn->state == NETWORK_CONNSTATE_OFFLINE) { if(p->flags == NETWORK_PACKETFLAG_CONNECT) { /* send response and init connection */ conn_reset(conn); conn->state = NETWORK_CONNSTATE_ONLINE; conn->connected++; conn->peeraddr = *addr; conn->token = p->token; conn->last_send_time = now; conn->last_recv_time = now; conn->last_update_time = now; conn_send(conn, NETWORK_PACKETFLAG_CONNECT|NETWORK_PACKETFLAG_ACCEPT, 0, 0); if(config.debug) dbg_msg("connection", "got connection, sending connect+accept"); } } else if(net_addr4_cmp(&conn->peeraddr, addr) == 0) { if(p->token != conn->token) return 0; if(conn->state == NETWORK_CONNSTATE_ONLINE) { /* remove packages that are acked */ conn_ack(conn, p->ack); /* check if resend is requested */ if(p->flags&NETWORK_PACKETFLAG_RESEND) conn_resend(conn); if(p->flags&NETWORK_PACKETFLAG_VITAL) { if(p->seq == (conn->ack+1)%NETWORK_MAX_SEQACK) { /* in sequence */ conn->ack = (conn->ack+1)%NETWORK_MAX_SEQACK; } else { /* out of sequence, request resend */ dbg_msg("conn", "asking for resend %d %d", p->seq, (conn->ack+1)%NETWORK_MAX_SEQACK); conn_send(conn, NETWORK_PACKETFLAG_RESEND, 0, 0); return 0; } } else { if(p->seq > conn->ack) conn_send(conn, NETWORK_PACKETFLAG_RESEND, 0, 0); } if(p->data_size == 0) return 0; return 1; } else if(conn->state == NETWORK_CONNSTATE_CONNECT) { /* connection made */ if(p->flags == (NETWORK_PACKETFLAG_CONNECT|NETWORK_PACKETFLAG_ACCEPT)) { conn_send(conn, NETWORK_PACKETFLAG_ACCEPT, 0, 0); conn->state = NETWORK_CONNSTATE_ONLINE; conn->connected++; dbg_msg("connection", "got connect+accept, sending accept. connection online"); } } /* else if(conn->state == NETWORK_CONNSTATE_CONNECTACCEPTED) { // connection made if(p->flags == NETWORK_PACKETFLAG_ACCEPT) { conn->state = NETWORK_CONNSTATE_ONLINE; dbg_msg("connection", "got accept. connection online"); } }*/ else { /* strange packet, wrong state */ conn->state = NETWORK_CONNSTATE_ERROR; conn_set_error(conn, "strange state and packet"); } } else { /* strange packet, not ment for me */ } return 0; } static int conn_update(NETCONNECTION *conn) { int64 now = time_get(); if(conn->state == NETWORK_CONNSTATE_OFFLINE || conn->state == NETWORK_CONNSTATE_ERROR) return 0; /* watch out for major hitches */ { int64 delta = now-conn->last_update_time; if(conn->last_update_time && delta > time_freq()/2) { RINGBUFFER_ITEM *item = conn->buffer.first; dbg_msg("conn", "hitch %d", (int)((delta*1000)/time_freq())); conn->last_recv_time += delta; while(item) { NETPACKETDATA *resend = (NETPACKETDATA *)rb_item_data(item); resend->first_send_time += delta; item = item->next; } } conn->last_update_time = now; } /* check for timeout */ if(conn->state != NETWORK_CONNSTATE_OFFLINE && conn->state != NETWORK_CONNSTATE_CONNECT && (now-conn->last_recv_time) > time_freq()*10) { conn->state = NETWORK_CONNSTATE_ERROR; conn_set_error(conn, "timeout"); } /* check for large buffer errors */ if(conn->buffer.buffer_size > 1024*64) { conn->state = NETWORK_CONNSTATE_ERROR; conn_set_error(conn, "too weak connection (out of buffer)"); } if(conn->buffer.first) { NETPACKETDATA *resend = (NETPACKETDATA *)(conn->buffer.first+1); if(now-resend->first_send_time > time_freq()*10) { conn->state = NETWORK_CONNSTATE_ERROR; conn_set_error(conn, "too weak connection (not acked for 10 seconds)"); } } /* send keep alives if nothing has happend for 250ms */ if(conn->state == NETWORK_CONNSTATE_ONLINE) { if(time_get()-conn->last_send_time> time_freq()/4) conn_send(conn, NETWORK_PACKETFLAG_VITAL, 0, 0); } else if(conn->state == NETWORK_CONNSTATE_CONNECT) { if(time_get()-conn->last_send_time > time_freq()/2) /* send a new connect every 500ms */ conn_send(conn, NETWORK_PACKETFLAG_CONNECT, 0, 0); } else if(conn->state == NETWORK_CONNSTATE_CONNECTACCEPTED) { if(time_get()-conn->last_send_time > time_freq()/2) /* send a new connect/accept every 500ms */ conn_send(conn, NETWORK_PACKETFLAG_CONNECT|NETWORK_PACKETFLAG_ACCEPT, 0, 0); } return 0; } static int check_packet(unsigned char *buffer, int size, NETPACKETDATA *packet) { /* check the size */ if(size < NETWORK_HEADER_SIZE || size > NETWORK_MAX_PACKET_SIZE) return -1; /* read the packet */ packet->ID[0] = 'T'; packet->ID[1] = 'W'; packet->version = NETWORK_VERSION; packet->flags = buffer[0]; packet->seq = ((buffer[1]&0xf0)<<4)|buffer[2]; packet->ack = ((buffer[1]&0x0f)<<8)|buffer[3]; packet->crc = 0; packet->token = (buffer[4]<<8)|buffer[5]; packet->data_size = size - NETWORK_HEADER_SIZE; packet->data = buffer+NETWORK_HEADER_SIZE; /* check the packet */ if(packet->ID[0] != 'T' || packet->ID[1] != 'W') return 1; if(packet->version != NETWORK_VERSION) return 1; /* TODO: perform crc check */ /* return success */ return 0; } NETSERVER *netserver_open(NETADDR4 bindaddr, int max_clients, int flags) { int i; NETSERVER *server; NETSOCKET socket = net_udp4_create(bindaddr); if(socket == NETSOCKET_INVALID) return 0; server = (NETSERVER *)mem_alloc(sizeof(NETSERVER), 1); mem_zero(server, sizeof(NETSERVER)); server->socket = socket; server->max_clients = max_clients; if(server->max_clients > NETWORK_MAX_CLIENTS) server->max_clients = NETWORK_MAX_CLIENTS; if(server->max_clients < 1) server->max_clients = 1; for(i = 0; i < NETWORK_MAX_CLIENTS; i++) conn_init(&server->slots[i].conn, server->socket); return server; } int netserver_set_callbacks(NETSERVER *s, NETFUNC_NEWCLIENT new_client, NETFUNC_DELCLIENT del_client, void *user) { s->new_client = new_client; s->del_client = del_client; s->user_ptr = user; return 0; } int netserver_max_clients(NETSERVER *s) { return s->max_clients; } int netserver_close(NETSERVER *s) { /* TODO: implement me */ return 0; } int netserver_drop(NETSERVER *s, int client_id, const char *reason) { /* TODO: insert lots of checks here */ dbg_msg("net_server", "client dropped. cid=%d reason=\"%s\"", client_id, reason); conn_disconnect(&s->slots[client_id].conn, reason); if(s->del_client) s->del_client(client_id, s->user_ptr); return 0; } int netserver_update(NETSERVER *s) { int i; for(i = 0; i < s->max_clients; i++) { conn_update(&s->slots[i].conn); if(s->slots[i].conn.state == NETWORK_CONNSTATE_ERROR) netserver_drop(s, i, conn_error(&s->slots[i].conn)); } return 0; } int netserver_recv(NETSERVER *s, NETPACKET *packet) { NETPACKETDATA data; int i, r, bytes, found; NETADDR4 addr; while(1) { bytes = net_udp4_recv(s->socket, &addr, s->recv_buffer, NETWORK_MAX_PACKET_SIZE); /* no more packets for now */ if(bytes <= 0) break; r = check_packet(s->recv_buffer, bytes, &data); if(r == 0) { if(data.flags&NETWORK_PACKETFLAG_CONNLESS) { /* connection less packets */ packet->client_id = -1; packet->address = addr; packet->flags = PACKETFLAG_CONNLESS; packet->data_size = data.data_size; packet->data = data.data; return 1; } else { /* ok packet, process it */ if(data.flags == NETWORK_PACKETFLAG_CONNECT) { found = 0; /* check if we already got this client */ for(i = 0; i < s->max_clients; i++) { if(s->slots[i].conn.state != NETWORK_CONNSTATE_OFFLINE && net_addr4_cmp(&s->slots[i].conn.peeraddr, &addr) == 0) { found = 1; /* silent ignore.. we got this client already */ break; } } /* client that wants to connect */ if(!found) { for(i = 0; i < s->max_clients; i++) { if(s->slots[i].conn.state == NETWORK_CONNSTATE_OFFLINE) { found = 1; conn_feed(&s->slots[i].conn, &data, &addr); if(s->new_client) s->new_client(i, s->user_ptr); break; } } } if(!found) { /* send connectionless packet */ const char errstring[] = "server full"; NETPACKETDATA p; p.ID[0] = 'T'; p.ID[1] = 'W'; p.version = NETWORK_VERSION; p.flags = NETWORK_PACKETFLAG_CLOSE; p.seq = 0; p.ack = 0; p.crc = 0; p.token = data.token; p.data_size = sizeof(errstring); p.data = (unsigned char *)errstring; send_packet(s->socket, &addr, &p); } } else { /* find matching slot */ for(i = 0; i < s->max_clients; i++) { if(net_addr4_cmp(&s->slots[i].conn.peeraddr, &addr) == 0) { if(conn_feed(&s->slots[i].conn, &data, &addr)) { if(data.data_size) { packet->client_id = i; packet->address = addr; packet->flags = 0; packet->data_size = data.data_size; packet->data = data.data; return 1; } } } } } } } else { /* errornous packet, drop it */ dbg_msg("server", "crazy packet"); } /* read header */ /* do checksum */ } return 0; } int netserver_send(NETSERVER *s, NETPACKET *packet) { dbg_assert(packet->data_size < NETWORK_MAX_PAYLOAD, "packet payload too big"); if(packet->flags&PACKETFLAG_CONNLESS) { /* send connectionless packet */ NETPACKETDATA p; p.ID[0] = 'T'; p.ID[1] = 'W'; p.version = NETWORK_VERSION; p.flags = NETWORK_PACKETFLAG_CONNLESS; p.seq = 0; p.ack = 0; p.crc = 0; p.data_size = packet->data_size; p.data = (unsigned char *)packet->data; send_packet(s->socket, &packet->address, &p); } else { int flags = 0; dbg_assert(packet->client_id >= 0, "errornous client id"); dbg_assert(packet->client_id < s->max_clients, "errornous client id"); if(packet->flags&PACKETFLAG_VITAL) flags |= NETWORK_PACKETFLAG_VITAL; conn_send(&s->slots[packet->client_id].conn, flags, packet->data_size, packet->data); } return 0; } void netserver_stats(NETSERVER *s, NETSTATS *stats) { int num_stats = sizeof(NETSTATS)/sizeof(int); int *istats = (int *)stats; int c, i; mem_zero(stats, sizeof(NETSTATS)); for(c = 0; c < s->max_clients; c++) { if(s->slots[c].conn.state != NETWORK_CONNSTATE_OFFLINE) { int *sstats = (int *)(&(s->slots[c].conn.stats)); for(i = 0; i < num_stats; i++) istats[i] += sstats[i]; } } } NETCLIENT *netclient_open(NETADDR4 bindaddr, int flags) { NETCLIENT *client = (NETCLIENT *)mem_alloc(sizeof(NETCLIENT), 1); mem_zero(client, sizeof(NETCLIENT)); client->socket = net_udp4_create(bindaddr); conn_init(&client->conn, client->socket); return client; } int netclient_close(NETCLIENT *c) { /* TODO: implement me */ return 0; } int netclient_update(NETCLIENT *c) { conn_update(&c->conn); if(c->conn.state == NETWORK_CONNSTATE_ERROR) netclient_disconnect(c, conn_error(&c->conn)); return 0; } int netclient_disconnect(NETCLIENT *c, const char *reason) { dbg_msg("netclient", "disconnected. reason=\"%s\"", reason); conn_disconnect(&c->conn, reason); return 0; } int netclient_connect(NETCLIENT *c, NETADDR4 *addr) { conn_connect(&c->conn, addr); return 0; } int netclient_recv(NETCLIENT *c, NETPACKET *packet) { while(1) { NETADDR4 addr; NETPACKETDATA data; int r; int bytes = net_udp4_recv(c->socket, &addr, c->recv_buffer, NETWORK_MAX_PACKET_SIZE); /* no more packets for now */ if(bytes <= 0) break; r = check_packet(c->recv_buffer, bytes, &data); if(r == 0) { if(data.flags&NETWORK_PACKETFLAG_CONNLESS) { /* connection less packets */ packet->client_id = -1; packet->address = addr; packet->flags = PACKETFLAG_CONNLESS; packet->data_size = data.data_size; packet->data = data.data; return 1; } else { if(conn_feed(&c->conn, &data, &addr)) { /* fill in packet */ packet->client_id = 0; packet->address = addr; packet->flags = 0; packet->data_size = data.data_size; packet->data = data.data; return 1; } else { /* errornous packet, drop it */ } } } } return 0; } int netclient_send(NETCLIENT *c, NETPACKET *packet) { dbg_assert(packet->data_size < NETWORK_MAX_PAYLOAD, "packet payload too big"); if(packet->flags&PACKETFLAG_CONNLESS) { /* send connectionless packet */ NETPACKETDATA p; p.ID[0] = 'T'; p.ID[1] = 'W'; p.version = NETWORK_VERSION; p.flags = NETWORK_PACKETFLAG_CONNLESS; p.seq = 0; p.ack = 0; p.crc = 0; p.token = 0; p.data_size = packet->data_size; p.data = (unsigned char *)packet->data; send_packet(c->socket, &packet->address, &p); } else { int flags = 0; dbg_assert(packet->client_id == 0, "errornous client id"); if(packet->flags&PACKETFLAG_VITAL) flags |= NETWORK_PACKETFLAG_VITAL; conn_send(&c->conn, flags, packet->data_size, packet->data); } return 0; } int netclient_state(NETCLIENT *c) { if(c->conn.state == NETWORK_CONNSTATE_ONLINE) return NETSTATE_ONLINE; if(c->conn.state == NETWORK_CONNSTATE_OFFLINE) return NETSTATE_OFFLINE; return NETSTATE_CONNECTING; } int netclient_gotproblems(NETCLIENT *c) { if(time_get() - c->conn.last_recv_time > time_freq()) return 1; return 0; } void netclient_stats(NETCLIENT *c, NETSTATS *stats) { *stats = c->conn.stats; } const char *netclient_error_string(NETCLIENT *c) { return conn_error(&c->conn); }