int csp_route_work(uint32_t timeout) {
csp_qfifo_t input;
csp_packet_t * packet;
csp_conn_t * conn;
csp_socket_t * socket;
#ifdef CSP_USE_RDP
/* Check connection timeouts (currently only for RDP) */
csp_conn_check_timeouts();
#endif
/* Get next packet to route */
if (csp_qfifo_read(&input) != CSP_ERR_NONE)
return -1;
packet = input.packet;
csp_log_packet("INP: S %u, D %u, Dp %u, Sp %u, Pr %u, Fl 0x%02X, Sz %"PRIu16" VIA: %s",
packet->id.src, packet->id.dst, packet->id.dport,
packet->id.sport, packet->id.pri, packet->id.flags, packet->length, input.interface->name);
/* Here there be promiscuous mode */
#ifdef CSP_USE_PROMISC
csp_promisc_add(packet);
#endif
#ifdef CSP_USE_DEDUP
/* Check for duplicates */
if (csp_dedup_is_duplicate(packet)) {
/* Discard packet */
csp_log_packet("Duplicate packet discarded");
csp_buffer_free(packet);
return 0;
}
#endif
/* If the message is not to me, route the message to the correct interface */
if ((packet->id.dst != csp_get_address()) && (packet->id.dst != CSP_BROADCAST_ADDR)) {
/* Find the destination interface */
csp_iface_t * dstif = csp_rtable_find_iface(packet->id.dst);
/* If the message resolves to the input interface, don't loop it back out */
if ((dstif == NULL) || ((dstif == input.interface) && (input.interface->split_horizon_off == 0))) {
csp_buffer_free(packet);
return 0;
}
/* Otherwise, actually send the message */
if (csp_send_direct(packet->id, packet, dstif, 0) != CSP_ERR_NONE) {
csp_log_warn("Router failed to send");
csp_buffer_free(packet);
}
/* Next message, please */
return 0;
}
/* Discard packets with unsupported options */
if (csp_route_check_options(input.interface, packet) != CSP_ERR_NONE) {
csp_buffer_free(packet);
return 0;
}
/* The message is to me, search for incoming socket */
socket = csp_port_get_socket(packet->id.dport);
/* If the socket is connection-less, deliver now */
if (socket && (socket->opts & CSP_SO_CONN_LESS)) {
if (csp_route_security_check(socket->opts, input.interface, packet) < 0) {
csp_buffer_free(packet);
return 0;
}
if (csp_queue_enqueue(socket->socket, &packet, 0) != CSP_QUEUE_OK) {
csp_log_error("Conn-less socket queue full");
csp_buffer_free(packet);
return 0;
}
return 0;
}
/* Search for an existing connection */
conn = csp_conn_find(packet->id.ext, CSP_ID_CONN_MASK);
/* If this is an incoming packet on a new connection */
if (conn == NULL) {
/* Reject packet if no matching socket is found */
if (!socket) {
csp_buffer_free(packet);
return 0;
}
/* Run security check on incoming packet */
if (csp_route_security_check(socket->opts, input.interface, packet) < 0) {
csp_buffer_free(packet);
return 0;
}
/* New incoming connection accepted */
csp_id_t idout;
idout.pri = packet->id.pri;
idout.src = csp_get_address();
idout.dst = packet->id.src;
idout.dport = packet->id.sport;
idout.sport = packet->id.dport;
idout.flags = packet->id.flags;
/* Create connection */
conn = csp_conn_new(packet->id, idout);
if (!conn) {
csp_log_error("No more connections available");
csp_buffer_free(packet);
return 0;
}
/* Store the socket queue and options */
conn->socket = socket->socket;
conn->opts = socket->opts;
/* Packet to existing connection */
} else {
/* Run security check on incoming packet */
if (csp_route_security_check(conn->opts, input.interface, packet) < 0) {
csp_buffer_free(packet);
return 0;
}
}
#ifdef CSP_USE_RDP
/* Pass packet to RDP module */
if (packet->id.flags & CSP_FRDP) {
csp_rdp_new_packet(conn, packet);
return 0;
}
#endif
/* Pass packet to UDP module */
csp_udp_new_packet(conn, packet);
return 0;
}
csp_conn_t * csp_connect(uint8_t prio, uint8_t dest, uint8_t dport, uint32_t timeout, uint32_t opts) {
/* Generate identifier */
csp_id_t incoming_id, outgoing_id;
incoming_id.pri = prio;
incoming_id.dst = my_address;
incoming_id.src = dest;
incoming_id.sport = dport;
incoming_id.flags = 0;
outgoing_id.pri = prio;
outgoing_id.dst = dest;
outgoing_id.src = my_address;
outgoing_id.dport = dport;
outgoing_id.flags = 0;
/* Set connection options */
if (opts & CSP_O_RDP) {
#ifdef CSP_USE_RDP
incoming_id.flags |= CSP_FRDP;
outgoing_id.flags |= CSP_FRDP;
#else
csp_log_error("Attempt to create RDP connection, but CSP was compiled without RDP support\r\n");
return NULL;
#endif
}
if (opts & CSP_O_HMAC) {
#ifdef CSP_USE_HMAC
outgoing_id.flags |= CSP_FHMAC;
incoming_id.flags |= CSP_FHMAC;
#else
csp_log_error("Attempt to create HMAC authenticated connection, but CSP was compiled without HMAC support\r\n");
return NULL;
#endif
}
if (opts & CSP_O_XTEA) {
#ifdef CSP_USE_XTEA
outgoing_id.flags |= CSP_FXTEA;
incoming_id.flags |= CSP_FXTEA;
#else
csp_log_error("Attempt to create XTEA encrypted connection, but CSP was compiled without XTEA support\r\n");
return NULL;
#endif
}
if (opts & CSP_O_CRC32) {
#ifdef CSP_USE_CRC32
outgoing_id.flags |= CSP_FCRC32;
incoming_id.flags |= CSP_FCRC32;
#else
csp_log_error("Attempt to create CRC32 validated connection, but CSP was compiled without CRC32 support\r\n");
return NULL;
#endif
}
/* Find an unused ephemeral port */
csp_conn_t * conn;
/* Wait for sport lock */
if (csp_bin_sem_wait(&sport_lock, 1000) != CSP_SEMAPHORE_OK)
return NULL;
uint8_t start = sport;
while (++sport != start) {
if (sport > CSP_ID_PORT_MAX)
sport = CSP_MAX_BIND_PORT + 1;
outgoing_id.sport = sport;
incoming_id.dport = sport;
/* Match on destination port of _incoming_ identifier */
conn = csp_conn_find(incoming_id.ext, CSP_ID_DPORT_MASK);
/* Break if we found an unused ephemeral port */
if (conn == NULL)
break;
}
/* Post sport lock */
csp_bin_sem_post(&sport_lock);
/* If no available ephemeral port was found */
if (sport == start)
return NULL;
/* Get storage for new connection */
conn = csp_conn_new(incoming_id, outgoing_id);
if (conn == NULL)
return NULL;
/* Set connection options */
conn->opts = opts;
#ifdef CSP_USE_RDP
/* Call Transport Layer connect */
if (outgoing_id.flags & CSP_FRDP) {
/* If the transport layer has failed to connect
* deallocate connection structure again and return NULL */
if (csp_rdp_connect(conn, timeout) != CSP_ERR_NONE) {
csp_close(conn);
return NULL;
}
}
#endif
/* We have a successful connection */
return conn;
}