--- /dev/null
+/*
+ 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 1
+
+/*
+ * Starting port for listening and sending, eventually a config value
+ */
+#define UDP_NAT_STARTING_PORT 24857
+
+/**
+ * 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;
+
+};
+
+
+/**
+ * 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
+ */
+ uint16_t 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;
+
+ /*
+ * 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;
+
+};
+
+/* *********** globals ************* */
+
+/**
+ * the socket that we transmit all data with
+ */
+static struct GNUNET_NETWORK_Handle *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]);
+ if (ok == GNUNET_OK)
+ udp_nat_socks[i] = 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;
+
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _
+ ("In udp_nat_send, ssize is %d, sending message to %s\n"), ssize, GNUNET_a2s((const struct sockaddr *)addr, addrlen));
+#endif
+ 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
+ {
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _
+ ("Successfully sent message, calling transmit continuation!\n"));
+#endif
+ 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;
+ 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;
+ }
+
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat",
+ _("Running gnunet-nat-client with address %s\n"), address_as_string);
+#endif
+ /* Start the server process */
+ pid = GNUNET_OS_start_process(NULL, NULL, "gnunet-nat-client", "gnunet-nat-client", plugin->external_address, address_as_string, NULL);
+ 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;
+
+ /**
+ * 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 (plugin->behind_nat == GNUNET_NO)
+ {
+ 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",
+ _("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 /* We are behind a NAT, so we can just send the message as is */
+ {
+ sent = udp_nat_real_send(cls, udp_nat_socks[0], 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;
+ v4->sin_port = htons (plugin->starting_port);
+ }
+ else
+ {
+ GNUNET_assert (af == AF_INET6);
+ v6 = (struct sockaddr_in6 *) addr;
+ 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, "<hostname>", 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);
+ //message->port = htons(probe->index + plugin->starting_port);
+ probe->sock_addr.sin_port = htons(probe->index + plugin->starting_port);
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat",
+ _("Sending a probe on port %d\n"), ntohs(probe->sock_addr.sin_port));
+#endif
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_INFO, "udp", _
+ ("about to send probe, ssize is %d, sending message to %s\n"), ntohs(message->header.size), GNUNET_a2s((const struct sockaddr *)&probe->sock_addr, sizeof(probe->sock_addr)));
+#endif
+ sent = udp_nat_real_send(plugin, udp_nat_socks[probe->index], NULL, (char *)message, ntohs(message->header.size), 0, GNUNET_TIME_relative_get_unit(), &probe->sock_addr, sizeof(probe->sock_addr), &udp_probe_continuation, probe);
+
+ if (probe->index + 1 < plugin->num_ports)
+ probe->index += 1;
+ else
+ probe->index = 0;
+
+}
+
+
+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 DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat",
+ _("Successfully sent a probe\n"));
+#endif
+ if (probe->index == 0)
+ probe->task = GNUNET_SCHEDULER_add_delayed(plugin->env->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 5000), &send_udp_probe_message, probe);
+ else
+ probe->task = GNUNET_SCHEDULER_add_delayed(plugin->env->sched, GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_MILLISECONDS, 500), &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;
+
+ 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;
+ }
+
+ for (i = 0; i < sizeof(mybuf); i++)
+ {
+ if (mybuf[i] == '\n')
+ mybuf[i] = '\0';
+ }
+
+#if DEBUG_UDP_NAT
+ GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp-nat",
+ _("nat-server-read read: %s\n"), &mybuf);
+#endif
+
+ /* Schedule sending of messages to peer on each open port */
+ 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->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, int receiving_port)
+{
+ 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;
+
+ 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 from port %d, sent_from port %d\n"), receiving_port, ((struct sockaddr_in *)sender_addr)->sin_port);
+#endif
+
+ sent = udp_nat_real_send(plugin, udp_nat_socks[0], 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 %d byes of PROBE REPLY\n"), sent);
+#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_INFO, "udp-nat",
+ _("Received a probe reply with ss_family %d!\n"), sender_addr->ss_family);
+#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 were 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, udp_nat_socks[receiving_port - plugin->starting_port], 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_INFO, "udp-nat",
+ _("Received a probe confirmation, but don't remember this peer!\n"));
+#endif
+ }
+ else if (peer_session->expecting_welcome == GNUNET_YES)
+ {
+ peer_session->expecting_welcome = GNUNET_NO;
+ peer_session->sock = udp_nat_socks[receiving_port - plugin->starting_port]; /* 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;
+ while (pending_message != NULL)
+ {
+ 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, &dummy_continuation, NULL);
+ pending_message_temp = pending_message;
+ pending_message = pending_message->next;
+ GNUNET_free(pending_message_temp->msgbuf);
+ GNUNET_free(pending_message_temp);
+ }
+ }
+
+ }
+ 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]);
+
+ if (buflen == GNUNET_NO)
+ break;
+
+ buf = GNUNET_malloc (buflen);
+ fromlen = sizeof (addr);
+ memset (&addr, 0, fromlen);
+ ret =
+ GNUNET_NETWORK_socket_recvfrom (udp_nat_socks[i], 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);
+ break;
+ }
+ 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);
+ break;
+ }
+ 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, plugin->starting_port + i);
+
+ 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->external_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] = 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])
+ {
+ udp_nat_socks[i] = GNUNET_NETWORK_socket_create (PF_INET, SOCK_DGRAM, 17);
+ if (NULL == udp_nat_socks[i])
+ {
+ 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_WEAK, 64537) + 1000); /* Find a non-root port */
+ addrlen = sizeof (serverAddrv4);
+ serverAddr = (struct sockaddr *) &serverAddrv4;
+ }
+ }
+
+ if (udp_nat_socks[i] != 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], serverAddr, addrlen) !=
+ GNUNET_OK)
+ {
+ serverAddrv4.sin_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_WEAK, 64537) + 1000); /* Find a 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
+ }
+ 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]);
+ }
+
+ 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)
+{
+ int i;
+
+ 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 *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_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",
+ "STARTING_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;
+ 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;
+
+ /* 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 */
projects / oweals / gnunet.git / commitdiff