/* This file is part of GNUnet (C) 2010 Christian Grothoff (and other contributing authors) GNUnet is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNUnet; see the file COPYING. If not, write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /** * @file transport/plugin_transport_udp.c * @brief Implementation of the UDP NAT punching * transport service * @author Christian Grothoff * @author Nathan Evans * * The idea with this transport is to connect gnunet peers to each other * when one or both is behind a NAT. This is based on pwnat * (http://samy.pl/pwnat) created by Samy Kamkar. This transport will * take external IP addresses for a NAT'd peer, start a server daemon * which sends ICMP messages out to a predefined address. Then it forks * a client process which sends ICMP death messages to the given external * IP address for the other peer (which has already also started the * server). If everything works according to plan, the transport will * be given a port which has worked to punch into the other external * addresses NAT to communicate with the other gnunet peer. Then keep * alive messages will be sent every (???)ms or so to keep the tunnel * safe. */ #include "platform.h" #include "gnunet_hello_lib.h" #include "gnunet_connection_lib.h" #include "gnunet_os_lib.h" #include "gnunet_peerinfo_service.h" #include "gnunet_protocols.h" #include "gnunet_resolver_service.h" #include "gnunet_server_lib.h" #include "gnunet_service_lib.h" #include "gnunet_signatures.h" #include "gnunet_statistics_service.h" #include "gnunet_transport_service.h" #include "plugin_transport.h" #include "transport.h" #define DEBUG_UDP_NAT GNUNET_YES /* * Transport cost to peer, always 1 for UDP (direct connection) */ #define UDP_DIRECT_DISTANCE 1 /** * Handle for request of hostname resolution, non-NULL if pending. */ static struct GNUNET_RESOLVER_RequestHandle *hostname_dns; /** * How long until we give up on transmitting the welcome message? */ #define HOSTNAME_RESOLVE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5) /* * How many ports do we want to listen on (and send on) in order to get replies? * * FIXME: make this value dynamic, specified by configuration */ #define UDP_NAT_LISTEN_PORTS 257 /* * Starting port for listening and sending, eventually a config value */ #define UDP_NAT_STARTING_PORT 22086 /** * UDP Message-Packet header. */ struct UDPMessage { /** * Message header. */ struct GNUNET_MessageHeader header; /** * What is the identity of the sender (GNUNET_hash of public key) */ struct GNUNET_PeerIdentity sender; }; /** * UDP NAT Probe message definition */ struct UDP_NAT_ProbeMessage { /** * Message header */ struct GNUNET_MessageHeader header; }; /** * UDP NAT Probe message reply definition */ struct UDP_NAT_ProbeMessageReply { /** * Message header */ struct GNUNET_MessageHeader header; }; /** * UDP NAT Probe message confirm definition */ struct UDP_NAT_ProbeMessageConfirmation { /** * Message header */ struct GNUNET_MessageHeader header; }; /* Forward definition */ struct Plugin; struct PrettyPrinterContext { GNUNET_TRANSPORT_AddressStringCallback asc; void *asc_cls; uint16_t port; }; struct MessageQueue { /** * Linked List */ struct MessageQueue *next; /** * Session this message belongs to */ struct PeerSession *session; /** * Actual message to be sent */ char *msgbuf; /** * Size of message buffer to be sent */ size_t msgbuf_size; /** * When to discard this message */ struct GNUNET_TIME_Absolute timeout; /** * Continuation to call when this message goes out */ GNUNET_TRANSPORT_TransmitContinuation cont; /** * closure for continuation */ void *cont_cls; }; /** * UDP NAT "Session" */ struct PeerSession { /** * Stored in a linked list. */ struct PeerSession *next; /** * Pointer to the global plugin struct. */ struct Plugin *plugin; /** * To whom are we talking to (set to our identity * if we are still waiting for the welcome message) */ struct GNUNET_PeerIdentity target; /** * Address of the other peer (either based on our 'connect' * call or on our 'accept' call). */ void *connect_addr; /** * Length of connect_addr. */ size_t connect_alen; /** * Are we still expecting the welcome message? (GNUNET_YES/GNUNET_NO) */ int expecting_welcome; /** * From which socket do we need to send to this peer? */ struct GNUNET_NETWORK_Handle *sock; /* * Queue of messages for this peer, in the case that * we have to await a connection... */ struct MessageQueue *messages; }; struct UDP_NAT_Probes { /** * Linked list */ struct UDP_NAT_Probes *next; /** * Address string that the server process returned to us */ char *address_string; /** * Timeout for this set of probes */ struct GNUNET_TIME_Absolute timeout; /** * Current index (which port to send on next basically) */ int index; /** * The plugin this probe belongs to */ struct Plugin *plugin; /** * The task used to send these probes */ GNUNET_SCHEDULER_TaskIdentifier task; /** * Network address (always ipv4) */ struct sockaddr_in sock_addr; /** * The port to send this probe to, 0 to choose randomly */ int port; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin { /** * Our environment. */ struct GNUNET_TRANSPORT_PluginEnvironment *env; /** * Handle for the statistics service. */ struct GNUNET_STATISTICS_Handle *statistics; /** * Handle to the network service. */ struct GNUNET_SERVICE_Context *service; /* * Session of peers with whom we are currently connected */ struct PeerSession *sessions; /** * Handle for request of hostname resolution, non-NULL if pending. */ struct GNUNET_RESOLVER_RequestHandle *hostname_dns; /** * ID of task used to update our addresses when one expires. */ GNUNET_SCHEDULER_TaskIdentifier address_update_task; /** * ID of select task */ GNUNET_SCHEDULER_TaskIdentifier select_task; /** * Starting port, will listen on num_ports (if available) starting * at this number (or will listen only on this port if non-nat'd) */ uint16_t starting_port; /** * Starting port for sending out crazy messages */ uint32_t random_starting_port; /** * How many ports should we be using? */ uint16_t num_ports; /** * The external address given to us by the user. Must be actual * outside visible address for NAT punching to work. */ char *external_address; /** * The internal address given to us by the user (or discovered). */ char *internal_address; /* * FD Read set */ struct GNUNET_NETWORK_FDSet *rs; /* * stdout pipe handle for the gnunet-nat-server process */ struct GNUNET_DISK_PipeHandle *server_stdout; /* * stdout file handle (for reading) for the gnunet-nat-server process */ const struct GNUNET_DISK_FileHandle *server_stdout_handle; /** * ID of select gnunet-nat-server stdout read task */ GNUNET_SCHEDULER_TaskIdentifier server_read_task; /** * Is this transport configured to be behind a NAT? */ int behind_nat; /** * The process id of the server process (if behind NAT) */ pid_t server_pid; /** * Probes in flight */ struct UDP_NAT_Probes *probes; }; struct UDP_Sock_Info { /* The network handle */ struct GNUNET_NETWORK_Handle *desc; /* The port we bound to */ int port; }; /* *********** globals ************* */ /** * the socket that we transmit all data with */ static struct UDP_Sock_Info *udp_nat_socks[UDP_NAT_LISTEN_PORTS]; /** * Forward declaration. */ void udp_probe_continuation (void *cls, const struct GNUNET_PeerIdentity *target, int result); /** * Disconnect from a remote node. * * @param tsession the session that is closed * @return GNUNET_OK on success, GNUNET_SYSERR if the operation failed */ void udp_nat_disconnect (void *cls, const struct GNUNET_PeerIdentity *target) { return; } /** * Shutdown the server process (stop receiving inbound traffic). Maybe * restarted later! */ static int udp_nat_transport_server_stop (void *cls) { struct Plugin *plugin = cls; int ret; int ok; int i; if (plugin->select_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (plugin->env->sched, plugin->select_task); plugin->select_task = GNUNET_SCHEDULER_NO_TASK; } for (i = 0; i < plugin->num_ports; i++) { ok = GNUNET_NETWORK_socket_close (udp_nat_socks[i]->desc); if (ok == GNUNET_OK) udp_nat_socks[i]->desc = NULL; ret += ok; } if (plugin->behind_nat == GNUNET_YES) { if (0 != PLIBC_KILL (plugin->server_pid, SIGTERM)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill"); } GNUNET_OS_process_wait (plugin->server_pid); } if (ret != GNUNET_OK) return GNUNET_SYSERR; return ret; } struct PeerSession * find_session (struct Plugin *plugin, const struct GNUNET_PeerIdentity *peer) { struct PeerSession *pos; pos = plugin->sessions; while (pos != NULL) { if (memcmp(&pos->target, peer, sizeof(struct GNUNET_PeerIdentity)) == 0) return pos; pos = pos->next; } return pos; } /** * Actually send out the message, assume we've got the address and * send_handle squared away! * * @param cls closure * @param send_handle which handle to send message on * @param target who should receive this message (ignored by UDP) * @param msgbuf one or more GNUNET_MessageHeader(s) strung together * @param msgbufsize the size of the msgbuf to send * @param priority how important is the message (ignored by UDP) * @param timeout when should we time out (give up) if we can not transmit? * @param addr the addr to send the message to, needs to be a sockaddr for us * @param addrlen the len of addr * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...) * @param cont_cls closure for cont * * @return the number of bytes written * */ static ssize_t udp_nat_real_send (void *cls, struct GNUNET_NETWORK_Handle *send_handle, const struct GNUNET_PeerIdentity *target, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative timeout, const void *addr, size_t addrlen, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; struct UDPMessage *message; int ssize; ssize_t sent; if ((addr == NULL) || (addrlen == 0)) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _ ("udp_nat_plugin_send called without address, returning!\n")); #endif cont (cont_cls, target, GNUNET_SYSERR); return 0; /* Can never send if we don't have an address!! */ } /* Build the message to be sent */ message = GNUNET_malloc (sizeof (struct UDPMessage) + msgbuf_size); ssize = sizeof (struct UDPMessage) + msgbuf_size; message->header.size = htons (ssize); message->header.type = htons (0); memcpy (&message->sender, plugin->env->my_identity, sizeof (struct GNUNET_PeerIdentity)); memcpy (&message[1], msgbuf, msgbuf_size); /* Actually send the message */ sent = GNUNET_NETWORK_socket_sendto (send_handle, message, ssize, addr, addrlen); if (cont != NULL) { if (sent == GNUNET_SYSERR) cont (cont_cls, target, GNUNET_SYSERR); else { cont (cont_cls, target, GNUNET_OK); } } GNUNET_free (message); return sent; } /** * We learned about a peer (possibly behind NAT) so run the * gnunet-nat-client to send a dummy ICMP response * * @param plugin the plugin for this transport * @param addr the address of the peer * @param addrlen the length of the address */ void run_gnunet_nat_client (struct Plugin *plugin, const char *addr, size_t addrlen) { char inet4[INET_ADDRSTRLEN]; char *address_as_string; char *port_as_string; pid_t pid; const struct sockaddr *sa = (const struct sockaddr *)addr; if (addrlen < sizeof (struct sockaddr)) return; switch (sa->sa_family) { case AF_INET: if (addrlen != sizeof (struct sockaddr_in)) return; inet_ntop (AF_INET, &((struct sockaddr_in *) sa)->sin_addr, inet4, INET_ADDRSTRLEN); address_as_string = GNUNET_strdup (inet4); break; case AF_INET6: default: return; } GNUNET_asprintf(&port_as_string, "%d", plugin->starting_port); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Running gnunet-nat-client with arguments: %s %s %d\n"), plugin->external_address, address_as_string, plugin->starting_port); #endif /* Start the server process */ pid = GNUNET_OS_start_process(NULL, NULL, "gnunet-nat-client", "gnunet-nat-client", plugin->external_address, address_as_string, port_as_string, NULL); GNUNET_free(address_as_string); GNUNET_free(port_as_string); GNUNET_OS_process_wait (pid); } /** * Function that can be used by the transport service to transmit * a message using the plugin. * * @param cls closure * @param target who should receive this message (ignored by UDP) * @param msgbuf one or more GNUNET_MessageHeader(s) strung together * @param msgbufsize the size of the msgbuf to send * @param priority how important is the message (ignored by UDP) * @param timeout when should we time out (give up) if we can not transmit? * @param addr the addr to send the message to, needs to be a sockaddr for us * @param addrlen the len of addr * @param force_address not used, we had better have an address to send to * because we are stateless!! * @param cont continuation to call once the message has * been transmitted (or if the transport is ready * for the next transmission call; or if the * peer disconnected...) * @param cont_cls closure for cont * * @return the number of bytes written */ static ssize_t udp_nat_plugin_send (void *cls, const struct GNUNET_PeerIdentity *target, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative timeout, const void *addr, size_t addrlen, int force_address, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; ssize_t sent; struct MessageQueue *temp_message; struct PeerSession *peer_session; struct sockaddr_in *sockaddr = (struct sockaddr_in *)addr; int other_peer_natd; other_peer_natd = GNUNET_NO; if ((sockaddr->sin_family == AF_INET) && (ntohs(sockaddr->sin_port) == 0)) { other_peer_natd = GNUNET_YES; } /** * FIXME: find which sock in udp_nat_socks to actually send the message on, * also this means creating some sort of structure to remember target to * udp sock (or address, or index of udp sock array...) */ sent = 0; if (other_peer_natd == GNUNET_YES) { peer_session = find_session(plugin, target); if (peer_session == NULL) /* We have a new peer to add */ { /* * The first time, we can assume we have no knowledge of a * working port for this peer, call the ICMP message sender * and wait... */ peer_session = GNUNET_malloc(sizeof(struct PeerSession)); peer_session->connect_addr = GNUNET_malloc(addrlen); memcpy(peer_session->connect_addr, addr, addrlen); peer_session->connect_alen = addrlen; peer_session->plugin = plugin; peer_session->sock = NULL; memcpy(&peer_session->target, target, sizeof(struct GNUNET_PeerIdentity)); peer_session->expecting_welcome = GNUNET_YES; peer_session->next = plugin->sessions; plugin->sessions = peer_session; peer_session->messages = GNUNET_malloc(sizeof(struct MessageQueue)); peer_session->messages->msgbuf = GNUNET_malloc(msgbuf_size); memcpy(peer_session->messages->msgbuf, msgbuf, msgbuf_size); peer_session->messages->msgbuf_size = msgbuf_size; peer_session->messages->next = NULL; peer_session->messages->timeout = GNUNET_TIME_relative_to_absolute(timeout); peer_session->messages->cont = cont; peer_session->messages->cont_cls = cont_cls; #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Other peer is NAT'd, set up peer session for peer %s\n"), GNUNET_i2s(target)); #endif run_gnunet_nat_client(plugin, addr, addrlen); } else { if (peer_session->expecting_welcome == GNUNET_NO) /* We are "connected" */ { sent = udp_nat_real_send(cls, peer_session->sock, target, msgbuf, msgbuf_size, priority, timeout, peer_session->connect_addr, peer_session->connect_alen, cont, cont_cls); } else /* Haven't gotten a response from this peer, queue message */ { temp_message = GNUNET_malloc(sizeof(struct MessageQueue)); temp_message->msgbuf = GNUNET_malloc(msgbuf_size); memcpy(temp_message->msgbuf, msgbuf, msgbuf_size); temp_message->msgbuf_size = msgbuf_size; temp_message->timeout = GNUNET_TIME_relative_to_absolute(timeout); temp_message->cont = cont; temp_message->cont_cls = cont_cls; temp_message->next = peer_session->messages; peer_session->messages = temp_message; } } } else /* Other peer not behind a NAT, so we can just send the message as is */ { sent = udp_nat_real_send(cls, udp_nat_socks[0]->desc, target, msgbuf, msgbuf_size, priority, timeout, addr, addrlen, cont, cont_cls); } return sent; } /** * Add the IP of our network interface to the list of * our external IP addresses. */ static int process_interfaces (void *cls, const char *name, int isDefault, const struct sockaddr *addr, socklen_t addrlen) { struct Plugin *plugin = cls; int af; struct sockaddr_in *v4; struct sockaddr_in6 *v6; /* * FIXME: Do we want to advertise _all_ of our UDP NAT addresses? * Probably not. Can we assume that we'll only send these out of band? * Ostensibly we won't accept just any connection on these ports anyways * right? */ af = addr->sa_family; if (af == AF_INET) { v4 = (struct sockaddr_in *) addr; if (plugin->behind_nat == GNUNET_YES) { inet_pton(AF_INET, plugin->external_address, &v4->sin_addr); v4->sin_port = htons (0); /* Indicates to receiver we are behind NAT */ } else v4->sin_port = htons (plugin->starting_port); } else { GNUNET_assert (af == AF_INET6); v6 = (struct sockaddr_in6 *) addr; if (plugin->behind_nat == GNUNET_YES) v6->sin6_port = htons (0); else v6->sin6_port = htons (plugin->starting_port); } #if !IPV6 if (af == AF_INET) { #endif GNUNET_log_from (GNUNET_ERROR_TYPE_INFO | GNUNET_ERROR_TYPE_BULK, "udp-nat", _("Found address `%s' (%s)\n"), GNUNET_a2s (addr, addrlen), name); plugin->env->notify_address (plugin->env->cls, "udp_nat", addr, addrlen, GNUNET_TIME_UNIT_FOREVER_REL); #if !IPV6 } #endif return GNUNET_OK; } /** * Function called by the resolver for each address obtained from DNS * for our own hostname. Add the addresses to the list of our * external IP addresses. * * @param cls closure * @param addr one of the addresses of the host, NULL for the last address * @param addrlen length of the address */ static void process_hostname_ips (void *cls, const struct sockaddr *addr, socklen_t addrlen) { struct Plugin *plugin = cls; if (addr == NULL) { plugin->hostname_dns = NULL; return; } process_interfaces (plugin, "", GNUNET_YES, addr, addrlen); } /** * Send UDP probe messages or UDP keepalive messages, depending on the * state of the connection. * * @param cls closure for this call (should be the main Plugin) * @param tc task context for running this */ static void send_udp_probe_message (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct UDP_NAT_Probes *probe = cls; struct UDP_NAT_ProbeMessage *message; struct Plugin *plugin = probe->plugin; int sent; message = GNUNET_malloc(sizeof(struct UDP_NAT_ProbeMessage)); message->header.size = htons(sizeof(struct UDP_NAT_ProbeMessage)); message->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE); /* Try the agreed upon port first, then go in order starting with our randomly chosen port */ if (probe->index == 0) { if (probe->port != 0) probe->sock_addr.sin_port = htons(probe->port); else probe->sock_addr.sin_port = htons(plugin->starting_port); } else probe->sock_addr.sin_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000); /* Find a non-root port */ #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Sending a probe to port %d\n"), ntohs(probe->sock_addr.sin_port)); #endif if (probe->index + 1 < plugin->num_ports) probe->index += 1; else probe->index = 0; sent = udp_nat_real_send(plugin, udp_nat_socks[probe->index]->desc, NULL, (char *)message, ntohs(message->header.size), 0, GNUNET_TIME_relative_get_unit(), &probe->sock_addr, sizeof(probe->sock_addr), &udp_probe_continuation, probe); GNUNET_free(message); } void dummy_continuation (void *cls, const struct GNUNET_PeerIdentity *target, int result) { return; } /** * Continuation for probe sends. If the last probe was sent * "successfully", schedule sending of another one. If not, * */ void udp_probe_continuation (void *cls, const struct GNUNET_PeerIdentity *target, int result) { struct UDP_NAT_Probes *probe = cls; struct Plugin *plugin = probe->plugin; if (result == GNUNET_OK) { if (probe->index == 0) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Scheduling next probe for 10000 milliseconds\n")); #endif probe->task = GNUNET_SCHEDULER_add_delayed(plugin->env->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 10000), &send_udp_probe_message, probe); } else { probe->task = GNUNET_SCHEDULER_add_delayed(plugin->env->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 50), &send_udp_probe_message, probe); } } else /* Destroy the probe context? */ { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Sending probe didn't go well...\n")); #endif } } /** * Find probe message by address * * @param plugin the plugin for this transport * @param address_string the ip address as a string */ struct UDP_NAT_Probes * find_probe(struct Plugin *plugin, char * address_string) { struct UDP_NAT_Probes *pos; pos = plugin->probes; while (pos != NULL) if (strcmp(pos->address_string, address_string) == 0) return pos; return pos; } /* * @param cls the plugin handle * @param tc the scheduling context (for rescheduling this function again) * * We have been notified that gnunet-nat-server has written something to stdout. * Handle the output, then reschedule this function to be called again once * more is available. * */ static void udp_nat_plugin_server_read (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Plugin *plugin = cls; char mybuf[40]; ssize_t bytes; memset(&mybuf, 0, sizeof(mybuf)); int i; struct UDP_NAT_Probes *temp_probe; int port; char *port_start; bytes = GNUNET_DISK_file_read(plugin->server_stdout_handle, &mybuf, sizeof(mybuf)); if (bytes < 1) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Finished reading from server stdout with code: %d\n"), bytes); #endif return; } port = 0; port_start = NULL; for (i = 0; i < sizeof(mybuf); i++) { if (mybuf[i] == '\n') mybuf[i] = '\0'; if ((mybuf[i] == ':') && (i + 1 < sizeof(mybuf))) { mybuf[i] = '\0'; port_start = &mybuf[i + 1]; } } if (port_start != NULL) port = atoi(port_start); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("nat-server-read read: %s port %d\n"), &mybuf, port); #endif /* Schedule sending of messages to peer on random ports */ temp_probe = find_probe(plugin, &mybuf[0]); if (temp_probe == NULL) { temp_probe = GNUNET_malloc(sizeof(struct UDP_NAT_Probes)); temp_probe->address_string = strdup(&mybuf[0]); temp_probe->sock_addr.sin_family = AF_INET; GNUNET_assert(inet_pton(AF_INET, &mybuf[0], &temp_probe->sock_addr.sin_addr) == 1); temp_probe->index = 0; temp_probe->port = port; temp_probe->next = plugin->probes; temp_probe->plugin = plugin; temp_probe->task = GNUNET_SCHEDULER_add_delayed(plugin->env->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 500), &send_udp_probe_message, temp_probe); plugin->probes = temp_probe; } plugin->server_read_task = GNUNET_SCHEDULER_add_read_file (plugin->env->sched, GNUNET_TIME_UNIT_FOREVER_REL, plugin->server_stdout_handle, &udp_nat_plugin_server_read, plugin); } /** * Demultiplexer for UDP NAT messages * * @param plugin the main plugin for this transport * */ static void udp_nat_demultiplexer(struct Plugin *plugin, struct GNUNET_PeerIdentity *sender, const struct GNUNET_MessageHeader *currhdr, struct sockaddr_storage *sender_addr, socklen_t fromlen, struct UDP_Sock_Info *sockinfo) { struct UDP_NAT_ProbeMessageReply *outgoing_probe_reply; struct UDP_NAT_ProbeMessageConfirmation *outgoing_probe_confirmation; struct UDP_NAT_ProbeMessage *incoming_probe; struct UDP_NAT_ProbeMessageReply *incoming_probe_reply; struct UDP_NAT_ProbeMessageConfirmation *incoming_probe_confirmation; char addr_buf[INET_ADDRSTRLEN]; struct UDP_NAT_Probes *outgoing_probe; struct PeerSession *peer_session; struct MessageQueue *pending_message; struct MessageQueue *pending_message_temp; int sent; if (memcmp(sender, plugin->env->my_identity, sizeof(struct GNUNET_PeerIdentity)) == 0) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Received a message from myself, dropping!!!\n")); #endif return; } switch (ntohs(currhdr->type)) { case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE: /* Send probe reply */ incoming_probe = (struct UDP_NAT_ProbeMessage *)currhdr; outgoing_probe_reply = GNUNET_malloc(sizeof(struct UDP_NAT_ProbeMessageReply)); outgoing_probe_reply->header.size = htons(sizeof(struct UDP_NAT_ProbeMessageReply)); outgoing_probe_reply->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE_REPLY); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Received a probe on listen port %d, sent_from port %d\n"), sockinfo->port, ntohs(((struct sockaddr_in *)sender_addr)->sin_port)); #endif sent = udp_nat_real_send(plugin, sockinfo->desc, NULL, (char *)outgoing_probe_reply, ntohs(outgoing_probe_reply->header.size), 0, GNUNET_TIME_relative_get_unit(), sender_addr, fromlen, &dummy_continuation, NULL); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Sent PROBE REPLY to port %d on outgoing port %d\n"), ntohs(((struct sockaddr_in *)sender_addr)->sin_port), sockinfo->port); #endif break; case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE_REPLY: /* Check for existing probe, check ports returned, send confirmation if all is well */ incoming_probe_reply = (struct UDP_NAT_ProbeMessageReply *)currhdr; #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Received PROBE REPLY from port %d on incoming port %d\n"), ntohs(((struct sockaddr_in *)sender_addr)->sin_port), sockinfo->port); #endif /* FIXME: use nonce, then IPv6 replies could work I think... */ if (sender_addr->ss_family == AF_INET) { memset(&addr_buf, 0, sizeof(addr_buf)); inet_ntop(AF_INET, &((struct sockaddr_in *) sender_addr)->sin_addr, addr_buf, INET_ADDRSTRLEN); outgoing_probe = find_probe(plugin, &addr_buf[0]); if (outgoing_probe != NULL) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Sending confirmation that we were reached!\n")); #endif outgoing_probe_confirmation = GNUNET_malloc(sizeof(struct UDP_NAT_ProbeMessageConfirmation)); outgoing_probe_confirmation->header.size = htons(sizeof(struct UDP_NAT_ProbeMessageConfirmation)); outgoing_probe_confirmation->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE_CONFIRM); sent = udp_nat_real_send(plugin, sockinfo->desc, NULL, (char *)outgoing_probe_confirmation, ntohs(outgoing_probe_confirmation->header.size), 0, GNUNET_TIME_relative_get_unit(), sender_addr, fromlen, &dummy_continuation, NULL); if (outgoing_probe->task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel(plugin->env->sched, outgoing_probe->task); outgoing_probe->task = GNUNET_SCHEDULER_NO_TASK; /* Schedule task to timeout and remove probe if confirmation not received */ } } else { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("Received a probe reply, but have no record of a sent probe!\n")); #endif } } break; case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE_CONFIRM: incoming_probe_confirmation = (struct UDP_NAT_ProbeMessageConfirmation *)currhdr; peer_session = find_session(plugin, sender); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Looking up peer session for peer %s\n"), GNUNET_i2s(sender)); #endif if (peer_session == NULL) /* Shouldn't this NOT happen? */ { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", _("Peer not in list, adding (THIS MAY BE A MISTAKE) %s\n"), GNUNET_i2s(sender)); #endif peer_session = GNUNET_malloc(sizeof(struct PeerSession)); peer_session->connect_addr = GNUNET_malloc(fromlen); memcpy(peer_session->connect_addr, sender_addr, fromlen); peer_session->connect_alen = fromlen; peer_session->plugin = plugin; peer_session->sock = sockinfo->desc; memcpy(&peer_session->target, sender, sizeof(struct GNUNET_PeerIdentity)); peer_session->expecting_welcome = GNUNET_NO; peer_session->next = plugin->sessions; plugin->sessions = peer_session; peer_session->messages = NULL; } else if (peer_session->expecting_welcome == GNUNET_YES) { peer_session->expecting_welcome = GNUNET_NO; /* FIXME: There is no way to find this based on receiving port at the moment! */ peer_session->sock = sockinfo->desc; /* This may matter, not sure right now... */ ((struct sockaddr_in *)peer_session->connect_addr)->sin_port = ((struct sockaddr_in *) sender_addr)->sin_port; #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("Received a probe confirmation, will send to peer on port %d\n"), ntohs(((struct sockaddr_in *)peer_session->connect_addr)->sin_port)); #endif if (peer_session->messages != NULL) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("Received a probe confirmation, sending queued messages.\n")); #endif pending_message = peer_session->messages; int count = 0; while (pending_message != NULL) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("sending queued message %d\n"), count); #endif udp_nat_real_send(plugin, peer_session->sock, &peer_session->target, pending_message->msgbuf, pending_message->msgbuf_size, 0, GNUNET_TIME_relative_get_unit(), peer_session->connect_addr, peer_session->connect_alen, pending_message->cont, pending_message->cont_cls); pending_message_temp = pending_message; pending_message = pending_message->next; GNUNET_free(pending_message_temp->msgbuf); GNUNET_free(pending_message_temp); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("finished sending queued message %d\n"), count); #endif count++; } } } else { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _("Received probe confirmation for already confirmed peer!\n")); #endif } /* Received confirmation, add peer with address/port specified */ break; case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_NAT_PROBE_KEEPALIVE: /* Once we've sent NAT_PROBE_CONFIRM change to sending keepalives */ /* If we receive these just ignore! */ break; default: plugin->env->receive (plugin->env->cls, sender, currhdr, UDP_DIRECT_DISTANCE, (char *)sender_addr, fromlen); } } /* * @param cls the plugin handle * @param tc the scheduling context (for rescheduling this function again) * * We have been notified that our writeset has something to read. We don't * know which socket needs to be read, so we have to check each one * Then reschedule this function to be called again once more is available. * */ static void udp_nat_plugin_select (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Plugin *plugin = cls; char *buf; struct UDPMessage *msg; const struct GNUNET_MessageHeader *hdr; struct GNUNET_PeerIdentity *sender; unsigned int buflen; socklen_t fromlen; struct sockaddr_storage addr; ssize_t ret; int offset; int count; int tsize; int i; char *msgbuf; const struct GNUNET_MessageHeader *currhdr; buf = NULL; sender = NULL; for (i = 0; i < plugin->num_ports; i++) { buflen = GNUNET_NETWORK_socket_recvfrom_amount (udp_nat_socks[i]->desc); if (buflen == GNUNET_NO) continue; buf = GNUNET_malloc (buflen); fromlen = sizeof (addr); memset (&addr, 0, fromlen); ret = GNUNET_NETWORK_socket_recvfrom (udp_nat_socks[i]->desc, buf, buflen, (struct sockaddr *) &addr, &fromlen); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp-nat", _ ("socket_recv returned %u, src_addr_len is %u\n"), ret, fromlen); #endif if (ret <= 0) { GNUNET_free (buf); continue; } msg = (struct UDPMessage *) buf; #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _ ("header reports message size of %d, type %d\n"), ntohs (msg->header.size), ntohs (msg->header.type)); #endif if (ntohs (msg->header.size) < sizeof (struct UDPMessage)) { GNUNET_free (buf); continue; } hdr = (const struct GNUNET_MessageHeader *) &msg[1]; msgbuf = (char *)&msg[1]; sender = GNUNET_malloc (sizeof (struct GNUNET_PeerIdentity)); memcpy (sender, &msg->sender, sizeof (struct GNUNET_PeerIdentity)); offset = 0; count = 0; tsize = ntohs (msg->header.size) - sizeof(struct UDPMessage); while (offset < tsize) { currhdr = (struct GNUNET_MessageHeader *)&msgbuf[offset]; #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _ ("processing msg %d: type %d, size %d at offset %d\n"), count, ntohs(currhdr->type), ntohs(currhdr->size), offset); #endif udp_nat_demultiplexer(plugin, sender, currhdr, &addr, fromlen, udp_nat_socks[i]); #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _ ("processing done msg %d: type %d, size %d at offset %d\n"), count, ntohs(currhdr->type), ntohs(currhdr->size), offset); #endif offset += ntohs(currhdr->size); count++; } } GNUNET_free_non_null (sender); GNUNET_free_non_null (buf); plugin->select_task = GNUNET_SCHEDULER_add_select (plugin->env->sched, GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_SCHEDULER_NO_TASK, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, NULL, &udp_nat_plugin_select, plugin); } /** * Create a slew of UDP sockets. If possible, use IPv6, otherwise * try IPv4. * * @param cls closure for server start, should be a struct Plugin * * * @return number of sockets created or GNUNET_SYSERR on error */ static int udp_nat_transport_server_start (void *cls) { struct Plugin *plugin = cls; struct sockaddr_in serverAddrv4; #if IPV6 struct sockaddr_in6 serverAddrv6; #endif struct sockaddr *serverAddr; socklen_t addrlen; int i; int sockets_created; /* Pipe to read from started processes stdout (on read end) */ plugin->server_stdout = GNUNET_DISK_pipe(GNUNET_YES); sockets_created = 0; if (plugin->server_stdout == NULL) return sockets_created; if (plugin->behind_nat == GNUNET_YES) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp_nat", "Starting gnunet-nat-server process\n"); #endif /* Start the server process */ plugin->server_pid = GNUNET_OS_start_process(NULL, plugin->server_stdout, "gnunet-nat-server", "gnunet-nat-server", plugin->internal_address, NULL); if (plugin->server_pid == GNUNET_SYSERR) return GNUNET_SYSERR; /* Close the write end of the read pipe */ GNUNET_DISK_pipe_close_end(plugin->server_stdout, GNUNET_DISK_PIPE_END_WRITE); plugin->server_stdout_handle = GNUNET_DISK_pipe_handle(plugin->server_stdout, GNUNET_DISK_PIPE_END_READ); plugin->server_read_task = GNUNET_SCHEDULER_add_read_file (plugin->env->sched, GNUNET_TIME_UNIT_FOREVER_REL, plugin->server_stdout_handle, &udp_nat_plugin_server_read, plugin); } /* Open all our sockets for reading/writing */ for (i = 0; i < plugin->num_ports; i++) { udp_nat_socks[i] = GNUNET_malloc(sizeof(struct UDP_Sock_Info)); udp_nat_socks[i]->desc = NULL; #if IPV6 if (GNUNET_YES != GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg, "GNUNETD", "DISABLE-IPV6")) { udp_nat_socks[i] = GNUNET_NETWORK_socket_create (PF_INET6, SOCK_DGRAM, 17); if (udp_nat_socks[i] != NULL) { memset (&serverAddrv6, 0, sizeof (serverAddrv6)); #if HAVE_SOCKADDR_IN_SIN_LEN serverAddrv6.sin6_len = sizeof (serverAddrv6); #endif serverAddrv6.sin6_family = AF_INET6; serverAddrv6.sin6_addr = in6addr_any; serverAddrv6.sin6_port = htons (i + plugin->starting_port); addrlen = sizeof (serverAddrv6); serverAddr = (struct sockaddr *) &serverAddrv6; } } #endif if (NULL == udp_nat_socks[i]->desc) { udp_nat_socks[i]->desc = GNUNET_NETWORK_socket_create (PF_INET, SOCK_DGRAM, 17); if (NULL == udp_nat_socks[i]->desc) { GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat", "socket"); return sockets_created; } else { memset (&serverAddrv4, 0, sizeof (serverAddrv4)); #if HAVE_SOCKADDR_IN_SIN_LEN serverAddrv4.sin_len = sizeof (serverAddrv4); #endif serverAddrv4.sin_family = AF_INET; serverAddrv4.sin_addr.s_addr = INADDR_ANY; if (i == 0) serverAddrv4.sin_port = htons (plugin->starting_port); else serverAddrv4.sin_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000); /* Find a non-root port */ addrlen = sizeof (serverAddrv4); serverAddr = (struct sockaddr *) &serverAddrv4; } } if (udp_nat_socks[i]->desc != NULL) { #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp_nat", "Binding to port %d\n", ntohs(serverAddrv4.sin_port)); #endif while (GNUNET_NETWORK_socket_bind (udp_nat_socks[i]->desc, serverAddr, addrlen) != GNUNET_OK) { serverAddrv4.sin_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000); /* Find a good, non-root port */ #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp_nat", "Binding failed, trying new port %d\n", ntohs(serverAddrv4.sin_port)); #endif } udp_nat_socks[i]->port = ntohs(serverAddrv4.sin_port); sockets_created++; } } plugin->rs = GNUNET_NETWORK_fdset_create (); GNUNET_NETWORK_fdset_zero (plugin->rs); for (i = 0; i < plugin->num_ports; i++) { GNUNET_NETWORK_fdset_set (plugin->rs, udp_nat_socks[i]->desc); } plugin->select_task = GNUNET_SCHEDULER_add_select (plugin->env->sched, GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_SCHEDULER_NO_TASK, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, NULL, &udp_nat_plugin_select, plugin); return sockets_created; } /** * Check if the given port is plausible (must be either * our listen port or our advertised port). If it is * neither, we return one of these two ports at random. * * @return either in_port or a more plausible port */ static uint16_t check_port (struct Plugin *plugin, uint16_t in_port) { /* FIXME: remember what ports we are using to better respond to this */ return in_port; /* for (i = plugin->starting_port; i < plugin->num_ports + plugin->starting_port; i++) { if (in_port == i) return in_port; } return GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK, plugin->num_ports) + plugin->starting_port; */ } /** * Another peer has suggested an address for this peer and transport * plugin. Check that this could be a valid address. This function * is not expected to 'validate' the address in the sense of trying to * connect to it but simply to see if the binary format is technically * legal for establishing a connection. * * @param addr pointer to the address, may be modified (slightly) * @param addrlen length of addr * @return GNUNET_OK if this is a plausible address for this peer * and transport, GNUNET_SYSERR if not * * TODO: perhaps make everything work with sockaddr_storage, it may * be a cleaner way to handle addresses in UDP */ static int udp_nat_check_address (void *cls, void *addr, size_t addrlen) { struct Plugin *plugin = cls; char buf[sizeof (struct sockaddr_in6)]; struct sockaddr_in *v4; struct sockaddr_in6 *v6; #if IPV6 if ((addrlen != sizeof (struct sockaddr_in)) && (addrlen != sizeof (struct sockaddr_in6))) #else if (addrlen != sizeof (struct sockaddr_in)) #endif { GNUNET_break_op (0); return GNUNET_SYSERR; } memcpy (buf, addr, sizeof (struct sockaddr_in6)); if (addrlen == sizeof (struct sockaddr_in)) { v4 = (struct sockaddr_in *) buf; v4->sin_port = htons (check_port (plugin, ntohs (v4->sin_port))); } else { v6 = (struct sockaddr_in6 *) buf; v6->sin6_port = htons (check_port (plugin, ntohs (v6->sin6_port))); } #if DEBUG_UDP_NAT GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp_nat", "Informing transport service about my address `%s'.\n", GNUNET_a2s (addr, addrlen)); #endif return GNUNET_OK; } /** * Append our port and forward the result. */ static void append_port (void *cls, const char *hostname) { struct PrettyPrinterContext *ppc = cls; char *ret; if (hostname == NULL) { ppc->asc (ppc->asc_cls, NULL); GNUNET_free (ppc); return; } GNUNET_asprintf (&ret, "%s:%d", hostname, ppc->port); ppc->asc (ppc->asc_cls, ret); GNUNET_free (ret); } /** * Convert the transports address to a nice, human-readable * format. * * @param cls closure * @param type name of the transport that generated the address * @param addr one of the addresses of the host, NULL for the last address * the specific address format depends on the transport * @param addrlen length of the address * @param numeric should (IP) addresses be displayed in numeric form? * @param timeout after how long should we give up? * @param asc function to call on each string * @param asc_cls closure for asc */ static void udp_nat_plugin_address_pretty_printer (void *cls, const char *type, const void *addr, size_t addrlen, int numeric, struct GNUNET_TIME_Relative timeout, GNUNET_TRANSPORT_AddressStringCallback asc, void *asc_cls) { struct Plugin *plugin = cls; const struct sockaddr_in *v4; const struct sockaddr_in6 *v6; struct PrettyPrinterContext *ppc; if ((addrlen != sizeof (struct sockaddr_in)) && (addrlen != sizeof (struct sockaddr_in6))) { /* invalid address */ GNUNET_break_op (0); asc (asc_cls, NULL); return; } ppc = GNUNET_malloc (sizeof (struct PrettyPrinterContext)); ppc->asc = asc; ppc->asc_cls = asc_cls; if (addrlen == sizeof (struct sockaddr_in)) { v4 = (const struct sockaddr_in *) addr; ppc->port = ntohs (v4->sin_port); } else { v6 = (const struct sockaddr_in6 *) addr; ppc->port = ntohs (v6->sin6_port); } GNUNET_RESOLVER_hostname_get (plugin->env->sched, plugin->env->cfg, addr, addrlen, !numeric, timeout, &append_port, ppc); } /** * Set a quota for receiving data from the given peer; this is a * per-transport limit. This call has no meaning for UDP, as if * we don't receive data it still comes in. UDP has no friendliness * guarantees, and our buffers will fill at some level. * * @param cls closure * @param target the peer for whom the quota is given * @param quota_in quota for receiving/sending data in bytes per ms */ static void udp_nat_plugin_set_receive_quota (void *cls, const struct GNUNET_PeerIdentity *target, uint32_t quota_in) { return; /* Do nothing */ } /** * The exported method. Makes the core api available via a global and * returns the udp transport API. */ void * libgnunet_plugin_transport_udp_nat_init (void *cls) { unsigned long long mtu; struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; struct GNUNET_TRANSPORT_PluginFunctions *api; struct Plugin *plugin; struct GNUNET_SERVICE_Context *service; int sockets_created; int behind_nat; char *internal_address; char *external_address; char *starting_port; service = GNUNET_SERVICE_start ("transport-udp-nat", env->sched, env->cfg); if (service == NULL) { GNUNET_log_from (GNUNET_ERROR_TYPE_WARNING, "udp_nat", _ ("Failed to start service for `%s' transport plugin.\n"), "udp-nat"); return NULL; } if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (env->cfg, "transport-udp-nat", "EXTERNAL_ADDRESS", &external_address)) { GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "udp_nat", _ ("Require EXTERNAL_ADDRESS for service `%s' in configuration!\n"), "transport-udp"); GNUNET_SERVICE_stop (service); } if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (env->cfg, "transport-udp-nat", "INTERNAL_ADDRESS", &internal_address)) { GNUNET_log_from (GNUNET_ERROR_TYPE_ERROR, "udp_nat", _ ("Require INTERNAL_ADDRESS for service `%s' in configuration!\n"), "transport-udp"); GNUNET_SERVICE_stop (service); } if (GNUNET_NO == GNUNET_CONFIGURATION_get_value_yesno (env->cfg, "transport-udp-nat", "BEHIND_NAT")) behind_nat = GNUNET_NO; /* We are not behind nat, or so says the user! */ else behind_nat = GNUNET_YES; /* Assume we are behind nat (default) */ GNUNET_CONFIGURATION_get_value_string (env->cfg, "transport-udp-nat", "PORT", &starting_port); mtu = 1240; if (mtu < 1200) GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp_nat", _("MTU %llu for `%s' is probably too low!\n"), mtu, "UDP"); plugin = GNUNET_malloc (sizeof (struct Plugin)); plugin->external_address = external_address; plugin->internal_address = internal_address; if (starting_port != NULL) plugin->starting_port = atoi(starting_port); else plugin->starting_port = UDP_NAT_STARTING_PORT; plugin->behind_nat = behind_nat; if (plugin->behind_nat == GNUNET_NO) plugin->num_ports = 1; /* Only use one port/socket */ else plugin->num_ports = UDP_NAT_LISTEN_PORTS; plugin->env = env; plugin->statistics = NULL; api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions)); api->cls = plugin; api->send = &udp_nat_plugin_send; api->disconnect = &udp_nat_disconnect; api->address_pretty_printer = &udp_nat_plugin_address_pretty_printer; api->set_receive_quota = &udp_nat_plugin_set_receive_quota; api->check_address = &udp_nat_check_address; plugin->service = service; plugin->random_starting_port = GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000; /* FIXME: do the two calls below periodically again and not just once (since the info we get might change...) */ GNUNET_OS_network_interfaces_list (&process_interfaces, plugin); plugin->hostname_dns = GNUNET_RESOLVER_hostname_resolve (env->sched, env->cfg, AF_UNSPEC, HOSTNAME_RESOLVE_TIMEOUT, &process_hostname_ips, plugin); sockets_created = udp_nat_transport_server_start (plugin); GNUNET_assert (sockets_created == plugin->num_ports); return api; } void * libgnunet_plugin_transport_udp_nat_done (void *cls) { struct GNUNET_TRANSPORT_PluginFunctions *api = cls; struct Plugin *plugin = api->cls; udp_nat_transport_server_stop (plugin); if (NULL != hostname_dns) { GNUNET_RESOLVER_request_cancel (hostname_dns); hostname_dns = NULL; } GNUNET_SERVICE_stop (plugin->service); GNUNET_NETWORK_fdset_destroy (plugin->rs); GNUNET_free (plugin); GNUNET_free (api); return NULL; } /* end of plugin_transport_udp.c */