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-rw-r--r--src/transport/plugin_transport_xu.c2492
1 files changed, 2492 insertions, 0 deletions
diff --git a/src/transport/plugin_transport_xu.c b/src/transport/plugin_transport_xu.c
new file mode 100644
index 0000000000..ea0d3f065d
--- /dev/null
+++ b/src/transport/plugin_transport_xu.c
@@ -0,0 +1,2492 @@
+/*
+ This file is part of GNUnet
+ Copyright (C) 2010-2017 GNUnet e.V.
+
+ 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 3, 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., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * @file transport/plugin_transport_xu.c
+ * @brief Implementation of the XU transport protocol
+ * @author Christian Grothoff
+ * @author Nathan Evans
+ * @author Matthias Wachs
+ */
+#include "platform.h"
+#include "plugin_transport_xu.h"
+#include "gnunet_hello_lib.h"
+#include "gnunet_util_lib.h"
+#include "gnunet_fragmentation_lib.h"
+#include "gnunet_nat_service.h"
+#include "gnunet_protocols.h"
+#include "gnunet_resolver_service.h"
+#include "gnunet_signatures.h"
+#include "gnunet_constants.h"
+#include "gnunet_statistics_service.h"
+#include "gnunet_transport_service.h"
+#include "gnunet_transport_plugin.h"
+#include "transport.h"
+
+#define LOG(kind,...) GNUNET_log_from (kind, "transport-xu", __VA_ARGS__)
+
+/**
+ * After how much inactivity should a XU session time out?
+ */
+#define XU_SESSION_TIME_OUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 60)
+
+
+/**
+ * XU Message-Packet header (after defragmentation).
+ */
+struct XUMessage
+{
+ /**
+ * Message header.
+ */
+ struct GNUNET_MessageHeader header;
+
+ /**
+ * Always zero for now.
+ */
+ uint32_t reserved;
+
+ /**
+ * What is the identity of the sender
+ */
+ struct GNUNET_PeerIdentity sender;
+
+};
+
+
+/**
+ * Closure for #append_port().
+ */
+struct PrettyPrinterContext
+{
+ /**
+ * DLL
+ */
+ struct PrettyPrinterContext *next;
+
+ /**
+ * DLL
+ */
+ struct PrettyPrinterContext *prev;
+
+ /**
+ * Our plugin.
+ */
+ struct Plugin *plugin;
+
+ /**
+ * Resolver handle
+ */
+ struct GNUNET_RESOLVER_RequestHandle *resolver_handle;
+
+ /**
+ * Function to call with the result.
+ */
+ GNUNET_TRANSPORT_AddressStringCallback asc;
+
+ /**
+ * Clsoure for @e asc.
+ */
+ void *asc_cls;
+
+ /**
+ * Timeout task
+ */
+ struct GNUNET_SCHEDULER_Task *timeout_task;
+
+ /**
+ * Is this an IPv6 address?
+ */
+ int ipv6;
+
+ /**
+ * Options
+ */
+ uint32_t options;
+
+ /**
+ * Port to add after the IP address.
+ */
+ uint16_t port;
+
+};
+
+
+/**
+ * Session with another peer.
+ */
+struct GNUNET_ATS_Session
+{
+ /**
+ * Which peer is this session for?
+ */
+ struct GNUNET_PeerIdentity target;
+
+ /**
+ * Tokenizer for inbound messages.
+ */
+ struct GNUNET_MessageStreamTokenizer *mst;
+
+ /**
+ * Plugin this session belongs to.
+ */
+ struct Plugin *plugin;
+
+ /**
+ * Session timeout task
+ */
+ struct GNUNET_SCHEDULER_Task *timeout_task;
+
+ /**
+ * When does this session time out?
+ */
+ struct GNUNET_TIME_Absolute timeout;
+
+ /**
+ * What time did we last transmit?
+ */
+ struct GNUNET_TIME_Absolute last_transmit_time;
+
+ /**
+ * expected delay for ACKs
+ */
+ struct GNUNET_TIME_Relative last_expected_ack_delay;
+
+ /**
+ * desired delay between XU messages
+ */
+ struct GNUNET_TIME_Relative last_expected_msg_delay;
+
+ /**
+ */
+ struct GNUNET_TIME_Relative flow_delay_for_other_peer;
+ struct GNUNET_TIME_Relative flow_delay_from_other_peer;
+
+ /**
+ * Our own address.
+ */
+ struct GNUNET_HELLO_Address *address;
+
+ /**
+ * Number of bytes waiting for transmission to this peer.
+ */
+ unsigned long long bytes_in_queue;
+
+ /**
+ * Number of messages waiting for transmission to this peer.
+ */
+ unsigned int msgs_in_queue;
+
+ /**
+ * Reference counter to indicate that this session is
+ * currently being used and must not be destroyed;
+ * setting @e in_destroy will destroy it as soon as
+ * possible.
+ */
+ unsigned int rc;
+
+ /**
+ * Network type of the address.
+ */
+ enum GNUNET_ATS_Network_Type scope;
+
+ /**
+ * Is this session about to be destroyed (sometimes we cannot
+ * destroy a session immediately as below us on the stack
+ * there might be code that still uses it; in this case,
+ * @e rc is non-zero).
+ */
+ int in_destroy;
+};
+
+
+
+/**
+ * If a session monitor is attached, notify it about the new
+ * session state.
+ *
+ * @param plugin our plugin
+ * @param session session that changed state
+ * @param state new state of the session
+ */
+static void
+notify_session_monitor (struct Plugin *plugin,
+ struct GNUNET_ATS_Session *session,
+ enum GNUNET_TRANSPORT_SessionState state)
+{
+ struct GNUNET_TRANSPORT_SessionInfo info;
+
+ if (NULL == plugin->sic)
+ return;
+ if (GNUNET_YES == session->in_destroy)
+ return; /* already destroyed, just RC>0 left-over actions */
+ memset (&info,
+ 0,
+ sizeof (info));
+ info.state = state;
+ info.is_inbound = GNUNET_SYSERR; /* hard to say */
+ info.num_msg_pending = session->msgs_in_queue;
+ info.num_bytes_pending = session->bytes_in_queue;
+ /* info.receive_delay remains zero as this is not supported by XU
+ (cannot selectively not receive from 'some' peer while continuing
+ to receive from others) */
+ info.session_timeout = session->timeout;
+ info.address = session->address;
+ plugin->sic (plugin->sic_cls,
+ session,
+ &info);
+}
+
+
+/**
+ * Return information about the given session to the monitor callback.
+ *
+ * @param cls the `struct Plugin` with the monitor callback (`sic`)
+ * @param peer peer we send information about
+ * @param value our `struct GNUNET_ATS_Session` to send information about
+ * @return #GNUNET_OK (continue to iterate)
+ */
+static int
+send_session_info_iter (void *cls,
+ const struct GNUNET_PeerIdentity *peer,
+ void *value)
+{
+ struct Plugin *plugin = cls;
+ struct GNUNET_ATS_Session *session = value;
+
+ (void) peer;
+ notify_session_monitor (plugin,
+ session,
+ GNUNET_TRANSPORT_SS_INIT);
+ notify_session_monitor (plugin,
+ session,
+ GNUNET_TRANSPORT_SS_UP);
+ return GNUNET_OK;
+}
+
+
+/**
+ * Begin monitoring sessions of a plugin. There can only
+ * be one active monitor per plugin (i.e. if there are
+ * multiple monitors, the transport service needs to
+ * multiplex the generated events over all of them).
+ *
+ * @param cls closure of the plugin
+ * @param sic callback to invoke, NULL to disable monitor;
+ * plugin will being by iterating over all active
+ * sessions immediately and then enter monitor mode
+ * @param sic_cls closure for @a sic
+ */
+static void
+xu_plugin_setup_monitor (void *cls,
+ GNUNET_TRANSPORT_SessionInfoCallback sic,
+ void *sic_cls)
+{
+ struct Plugin *plugin = cls;
+
+ plugin->sic = sic;
+ plugin->sic_cls = sic_cls;
+ if (NULL != sic)
+ {
+ GNUNET_CONTAINER_multipeermap_iterate (plugin->sessions,
+ &send_session_info_iter,
+ plugin);
+ /* signal end of first iteration */
+ sic (sic_cls,
+ NULL,
+ NULL);
+ }
+}
+
+
+/* ****************** Little Helpers ****************** */
+
+
+/**
+ * Function to free last resources associated with a session.
+ *
+ * @param s session to free
+ */
+static void
+free_session (struct GNUNET_ATS_Session *s)
+{
+ if (NULL != s->address)
+ {
+ GNUNET_HELLO_address_free (s->address);
+ s->address = NULL;
+ }
+ if (NULL != s->mst)
+ {
+ GNUNET_MST_destroy (s->mst);
+ s->mst = NULL;
+ }
+ GNUNET_free (s);
+}
+
+
+/**
+ * Function that is called to get the keepalive factor.
+ * #GNUNET_CONSTANTS_IDLE_CONNECTION_TIMEOUT is divided by this number to
+ * calculate the interval between keepalive packets.
+ *
+ * @param cls closure with the `struct Plugin`
+ * @return keepalive factor
+ */
+static unsigned int
+xu_query_keepalive_factor (void *cls)
+{
+ (void) cls;
+ return 15;
+}
+
+
+/**
+ * Function obtain the network type for a session
+ *
+ * @param cls closure (`struct Plugin *`)
+ * @param session the session
+ * @return the network type
+ */
+static enum GNUNET_ATS_Network_Type
+xu_plugin_get_network (void *cls,
+ struct GNUNET_ATS_Session *session)
+{
+ (void) cls;
+ return session->scope;
+}
+
+
+/**
+ * Function obtain the network type for an address.
+ *
+ * @param cls closure (`struct Plugin *`)
+ * @param address the address
+ * @return the network type
+ */
+static enum GNUNET_ATS_Network_Type
+xu_plugin_get_network_for_address (void *cls,
+ const struct GNUNET_HELLO_Address *address)
+{
+ struct Plugin *plugin = cls;
+ size_t addrlen;
+ struct sockaddr_in a4;
+ struct sockaddr_in6 a6;
+ const struct IPv4XuAddress *u4;
+ const struct IPv6XuAddress *u6;
+ const void *sb;
+ size_t sbs;
+
+ addrlen = address->address_length;
+ if (addrlen == sizeof(struct IPv6XuAddress))
+ {
+ GNUNET_assert (NULL != address->address); /* make static analysis happy */
+ u6 = address->address;
+ memset (&a6, 0, sizeof(a6));
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ a6.sin6_len = sizeof (a6);
+#endif
+ a6.sin6_family = AF_INET6;
+ a6.sin6_port = u6->u6_port;
+ GNUNET_memcpy (&a6.sin6_addr, &u6->ipv6_addr, sizeof(struct in6_addr));
+ sb = &a6;
+ sbs = sizeof(a6);
+ }
+ else if (addrlen == sizeof(struct IPv4XuAddress))
+ {
+ GNUNET_assert (NULL != address->address); /* make static analysis happy */
+ u4 = address->address;
+ memset (&a4, 0, sizeof(a4));
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ a4.sin_len = sizeof (a4);
+#endif
+ a4.sin_family = AF_INET;
+ a4.sin_port = u4->u4_port;
+ a4.sin_addr.s_addr = u4->ipv4_addr;
+ sb = &a4;
+ sbs = sizeof(a4);
+ }
+ else
+ {
+ GNUNET_break (0);
+ return GNUNET_ATS_NET_UNSPECIFIED;
+ }
+ return plugin->env->get_address_type (plugin->env->cls,
+ sb,
+ sbs);
+}
+
+
+/* ******************* Event loop ******************** */
+
+/**
+ * We have been notified that our readset 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.
+ *
+ * @param cls the plugin handle
+ */
+static void
+xu_plugin_select_v4 (void *cls);
+
+
+/**
+ * We have been notified that our readset 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.
+ *
+ * @param cls the plugin handle
+ */
+static void
+xu_plugin_select_v6 (void *cls);
+
+
+/**
+ * (re)schedule IPv4-select tasks for this plugin.
+ *
+ * @param plugin plugin to reschedule
+ */
+static void
+schedule_select_v4 (struct Plugin *plugin)
+{
+ if ( (GNUNET_YES != plugin->enable_ipv4) ||
+ (NULL == plugin->sockv4) )
+ return;
+ if (NULL != plugin->select_task_v4)
+ GNUNET_SCHEDULER_cancel (plugin->select_task_v4);
+ plugin->select_task_v4
+ = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
+ plugin->sockv4,
+ &xu_plugin_select_v4,
+ plugin);
+}
+
+
+/**
+ * (re)schedule IPv6-select tasks for this plugin.
+ *
+ * @param plugin plugin to reschedule
+ */
+static void
+schedule_select_v6 (struct Plugin *plugin)
+{
+ if ( (GNUNET_YES != plugin->enable_ipv6) ||
+ (NULL == plugin->sockv6) )
+ return;
+ if (NULL != plugin->select_task_v6)
+ GNUNET_SCHEDULER_cancel (plugin->select_task_v6);
+ plugin->select_task_v6
+ = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
+ plugin->sockv6,
+ &xu_plugin_select_v6,
+ plugin);
+}
+
+
+/* ******************* Address to string and back ***************** */
+
+
+/**
+ * Function called for a quick conversion of the binary address to
+ * a numeric address. Note that the caller must not free the
+ * address and that the next call to this function is allowed
+ * to override the address again.
+ *
+ * @param cls closure
+ * @param addr binary address (a `union XuAddress`)
+ * @param addrlen length of the @a addr
+ * @return string representing the same address
+ */
+const char *
+xu_address_to_string (void *cls,
+ const void *addr,
+ size_t addrlen)
+{
+ static char rbuf[INET6_ADDRSTRLEN + 10];
+ char buf[INET6_ADDRSTRLEN];
+ const void *sb;
+ struct in_addr a4;
+ struct in6_addr a6;
+ const struct IPv4XuAddress *t4;
+ const struct IPv6XuAddress *t6;
+ int af;
+ uint16_t port;
+ uint32_t options;
+
+ (void) cls;
+ if (NULL == addr)
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+
+ if (addrlen == sizeof(struct IPv6XuAddress))
+ {
+ t6 = addr;
+ af = AF_INET6;
+ options = ntohl (t6->options);
+ port = ntohs (t6->u6_port);
+ a6 = t6->ipv6_addr;
+ sb = &a6;
+ }
+ else if (addrlen == sizeof(struct IPv4XuAddress))
+ {
+ t4 = addr;
+ af = AF_INET;
+ options = ntohl (t4->options);
+ port = ntohs (t4->u4_port);
+ a4.s_addr = t4->ipv4_addr;
+ sb = &a4;
+ }
+ else
+ {
+ GNUNET_break_op (0);
+ return NULL;
+ }
+ inet_ntop (af,
+ sb,
+ buf,
+ INET6_ADDRSTRLEN);
+ GNUNET_snprintf (rbuf,
+ sizeof(rbuf),
+ (af == AF_INET6)
+ ? "%s.%u.[%s]:%u"
+ : "%s.%u.%s:%u",
+ PLUGIN_NAME,
+ options,
+ buf,
+ port);
+ return rbuf;
+}
+
+
+/**
+ * Function called to convert a string address to a binary address.
+ *
+ * @param cls closure (`struct Plugin *`)
+ * @param addr string address
+ * @param addrlen length of the address
+ * @param buf location to store the buffer
+ * @param added location to store the number of bytes in the buffer.
+ * If the function returns #GNUNET_SYSERR, its contents are undefined.
+ * @return #GNUNET_OK on success, #GNUNET_SYSERR on failure
+ */
+static int
+xu_string_to_address (void *cls,
+ const char *addr,
+ uint16_t addrlen,
+ void **buf,
+ size_t *added)
+{
+ struct sockaddr_storage socket_address;
+ char *address;
+ char *plugin;
+ char *optionstr;
+ uint32_t options;
+
+ (void) cls;
+ /* Format tcp.options.address:port */
+ address = NULL;
+ plugin = NULL;
+ optionstr = NULL;
+
+ if ((NULL == addr) || (0 == addrlen))
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ if ('\0' != addr[addrlen - 1])
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ if (strlen (addr) + 1 != (size_t) addrlen)
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+ plugin = GNUNET_strdup (addr);
+ optionstr = strchr (plugin, '.');
+ if (NULL == optionstr)
+ {
+ GNUNET_break (0);
+ GNUNET_free (plugin);
+ return GNUNET_SYSERR;
+ }
+ optionstr[0] = '\0';
+ optionstr++;
+ options = atol (optionstr);
+ address = strchr (optionstr, '.');
+ if (NULL == address)
+ {
+ GNUNET_break (0);
+ GNUNET_free (plugin);
+ return GNUNET_SYSERR;
+ }
+ address[0] = '\0';
+ address++;
+
+ if (GNUNET_OK !=
+ GNUNET_STRINGS_to_address_ip (address,
+ strlen (address),
+ &socket_address))
+ {
+ GNUNET_break (0);
+ GNUNET_free (plugin);
+ return GNUNET_SYSERR;
+ }
+ GNUNET_free(plugin);
+
+ switch (socket_address.ss_family)
+ {
+ case AF_INET:
+ {
+ struct IPv4XuAddress *u4;
+ const struct sockaddr_in *in4 = (const struct sockaddr_in *) &socket_address;
+
+ u4 = GNUNET_new (struct IPv4XuAddress);
+ u4->options = htonl (options);
+ u4->ipv4_addr = in4->sin_addr.s_addr;
+ u4->u4_port = in4->sin_port;
+ *buf = u4;
+ *added = sizeof (struct IPv4XuAddress);
+ return GNUNET_OK;
+ }
+ case AF_INET6:
+ {
+ struct IPv6XuAddress *u6;
+ const struct sockaddr_in6 *in6 = (const struct sockaddr_in6 *) &socket_address;
+
+ u6 = GNUNET_new (struct IPv6XuAddress);
+ u6->options = htonl (options);
+ u6->ipv6_addr = in6->sin6_addr;
+ u6->u6_port = in6->sin6_port;
+ *buf = u6;
+ *added = sizeof (struct IPv6XuAddress);
+ return GNUNET_OK;
+ }
+ default:
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
+ }
+}
+
+
+/**
+ * Append our port and forward the result.
+ *
+ * @param cls a `struct PrettyPrinterContext *`
+ * @param hostname result from DNS resolver
+ */
+static void
+append_port (void *cls,
+ const char *hostname)
+{
+ struct PrettyPrinterContext *ppc = cls;
+ struct Plugin *plugin = ppc->plugin;
+ char *ret;
+
+ if (NULL == hostname)
+ {
+ /* Final call, done */
+ GNUNET_CONTAINER_DLL_remove (plugin->ppc_dll_head,
+ plugin->ppc_dll_tail,
+ ppc);
+ ppc->resolver_handle = NULL;
+ ppc->asc (ppc->asc_cls,
+ NULL,
+ GNUNET_OK);
+ GNUNET_free (ppc);
+ return;
+ }
+ if (GNUNET_YES == ppc->ipv6)
+ GNUNET_asprintf (&ret,
+ "%s.%u.[%s]:%d",
+ PLUGIN_NAME,
+ ppc->options,
+ hostname,
+ ppc->port);
+ else
+ GNUNET_asprintf (&ret,
+ "%s.%u.%s:%d",
+ PLUGIN_NAME,
+ ppc->options,
+ hostname,
+ ppc->port);
+ ppc->asc (ppc->asc_cls,
+ ret,
+ GNUNET_OK);
+ GNUNET_free (ret);
+}
+
+
+/**
+ * Convert the transports address to a nice, human-readable format.
+ *
+ * @param cls closure with the `struct Plugin *`
+ * @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;
+ * a `union XuAddress`
+ * @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 @a asc
+ */
+static void
+xu_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;
+ struct PrettyPrinterContext *ppc;
+ const struct sockaddr *sb;
+ size_t sbs;
+ struct sockaddr_in a4;
+ struct sockaddr_in6 a6;
+ const struct IPv4XuAddress *u4;
+ const struct IPv6XuAddress *u6;
+ uint16_t port;
+ uint32_t options;
+
+ (void) type;
+ if (addrlen == sizeof(struct IPv6XuAddress))
+ {
+ u6 = addr;
+ memset (&a6,
+ 0,
+ sizeof (a6));
+ a6.sin6_family = AF_INET6;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ a6.sin6_len = sizeof (a6);
+#endif
+ a6.sin6_port = u6->u6_port;
+ a6.sin6_addr = u6->ipv6_addr;
+ port = ntohs (u6->u6_port);
+ options = ntohl (u6->options);
+ sb = (const struct sockaddr *) &a6;
+ sbs = sizeof (a6);
+ }
+ else if (addrlen == sizeof (struct IPv4XuAddress))
+ {
+ u4 = addr;
+ memset (&a4,
+ 0,
+ sizeof(a4));
+ a4.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ a4.sin_len = sizeof (a4);
+#endif
+ a4.sin_port = u4->u4_port;
+ a4.sin_addr.s_addr = u4->ipv4_addr;
+ port = ntohs (u4->u4_port);
+ options = ntohl (u4->options);
+ sb = (const struct sockaddr *) &a4;
+ sbs = sizeof(a4);
+ }
+ else
+ {
+ /* invalid address */
+ GNUNET_break_op (0);
+ asc (asc_cls,
+ NULL,
+ GNUNET_SYSERR);
+ asc (asc_cls,
+ NULL,
+ GNUNET_OK);
+ return;
+ }
+ ppc = GNUNET_new (struct PrettyPrinterContext);
+ ppc->plugin = plugin;
+ ppc->asc = asc;
+ ppc->asc_cls = asc_cls;
+ ppc->port = port;
+ ppc->options = options;
+ if (addrlen == sizeof (struct IPv6XuAddress))
+ ppc->ipv6 = GNUNET_YES;
+ else
+ ppc->ipv6 = GNUNET_NO;
+ GNUNET_CONTAINER_DLL_insert (plugin->ppc_dll_head,
+ plugin->ppc_dll_tail,
+ ppc);
+ ppc->resolver_handle
+ = GNUNET_RESOLVER_hostname_get (sb,
+ sbs,
+ ! numeric,
+ timeout,
+ &append_port,
+ ppc);
+}
+
+
+/**
+ * Check if the given port is plausible (must be either our listen
+ * port or our advertised port). If it is neither, we return
+ * #GNUNET_SYSERR.
+ *
+ * @param plugin global variables
+ * @param in_port port number to check
+ * @return #GNUNET_OK if port is either our open or advertised port
+ */
+static int
+check_port (const struct Plugin *plugin,
+ uint16_t in_port)
+{
+ if ( (plugin->port == in_port) ||
+ (plugin->aport == in_port) )
+ return GNUNET_OK;
+ return GNUNET_SYSERR;
+}
+
+
+/**
+ * Function that will be called to check if a binary address for this
+ * plugin is well-formed and corresponds to an address for THIS peer
+ * (as per our configuration). Naturally, if absolutely necessary,
+ * plugins can be a bit conservative in their answer, but in general
+ * plugins should make sure that the address does not redirect
+ * traffic to a 3rd party that might try to man-in-the-middle our
+ * traffic.
+ *
+ * @param cls closure, should be our handle to the Plugin
+ * @param addr pointer to a `union XuAddress`
+ * @param addrlen length of @a addr
+ * @return #GNUNET_OK if this is a plausible address for this peer
+ * and transport, #GNUNET_SYSERR if not
+ */
+static int
+xu_plugin_check_address (void *cls,
+ const void *addr,
+ size_t addrlen)
+{
+ struct Plugin *plugin = cls;
+ const struct IPv4XuAddress *v4;
+ const struct IPv6XuAddress *v6;
+
+ if (sizeof(struct IPv4XuAddress) == addrlen)
+ {
+ struct sockaddr_in s4;
+
+ v4 = (const struct IPv4XuAddress *) addr;
+ if (GNUNET_OK != check_port (plugin,
+ ntohs (v4->u4_port)))
+ return GNUNET_SYSERR;
+ memset (&s4, 0, sizeof (s4));
+ s4.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ s4.sin_len = sizeof (s4);
+#endif
+ s4.sin_port = v4->u4_port;
+ s4.sin_addr.s_addr = v4->ipv4_addr;
+
+ if (GNUNET_OK !=
+ GNUNET_NAT_test_address (plugin->nat,
+ &s4,
+ sizeof (struct sockaddr_in)))
+ return GNUNET_SYSERR;
+ }
+ else if (sizeof(struct IPv6XuAddress) == addrlen)
+ {
+ struct sockaddr_in6 s6;
+
+ v6 = (const struct IPv6XuAddress *) addr;
+ if (IN6_IS_ADDR_LINKLOCAL (&v6->ipv6_addr))
+ return GNUNET_OK; /* plausible, if unlikely... */
+ memset (&s6, 0, sizeof (s6));
+ s6.sin6_family = AF_INET6;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ s6.sin6_len = sizeof (s6);
+#endif
+ s6.sin6_port = v6->u6_port;
+ s6.sin6_addr = v6->ipv6_addr;
+
+ if (GNUNET_OK !=
+ GNUNET_NAT_test_address (plugin->nat,
+ &s6,
+ sizeof(struct sockaddr_in6)))
+ return GNUNET_SYSERR;
+ }
+ else
+ {
+ GNUNET_break_op (0);
+ return GNUNET_SYSERR;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Our external IP address/port mapping has changed.
+ *
+ * @param cls closure, the `struct Plugin`
+ * @param add_remove #GNUNET_YES to mean the new public IP address,
+ * #GNUNET_NO to mean the previous (now invalid) one
+ * @param ac address class the address belongs to
+ * @param addr either the previous or the new public IP address
+ * @param addrlen actual length of the @a addr
+ */
+static void
+xu_nat_port_map_callback (void *cls,
+ int add_remove,
+ enum GNUNET_NAT_AddressClass ac,
+ const struct sockaddr *addr,
+ socklen_t addrlen)
+{
+ struct Plugin *plugin = cls;
+ struct GNUNET_HELLO_Address *address;
+ struct IPv4XuAddress u4;
+ struct IPv6XuAddress u6;
+ void *arg;
+ size_t args;
+
+ if (GNUNET_NAT_AC_LOOPBACK == ac)
+ return;
+ if (GNUNET_NAT_AC_LAN == ac)
+ return;
+ if (GNUNET_NAT_AC_LAN_PRIVATE == ac)
+ return;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ (GNUNET_YES == add_remove)
+ ? "NAT notification to add address `%s'\n"
+ : "NAT notification to remove address `%s'\n",
+ GNUNET_a2s (addr,
+ addrlen));
+ /* convert 'address' to our internal format */
+ switch (addr->sa_family)
+ {
+ case AF_INET:
+ {
+ const struct sockaddr_in *i4;
+
+ GNUNET_assert (sizeof(struct sockaddr_in) == addrlen);
+ i4 = (const struct sockaddr_in *) addr;
+ if (0 == ntohs (i4->sin_port))
+ return; /* Port = 0 means unmapped, ignore these for XU. */
+ memset (&u4,
+ 0,
+ sizeof(u4));
+ u4.options = htonl (plugin->myoptions);
+ u4.ipv4_addr = i4->sin_addr.s_addr;
+ u4.u4_port = i4->sin_port;
+ arg = &u4;
+ args = sizeof (struct IPv4XuAddress);
+ break;
+ }
+ case AF_INET6:
+ {
+ const struct sockaddr_in6 *i6;
+
+ GNUNET_assert (sizeof(struct sockaddr_in6) == addrlen);
+ i6 = (const struct sockaddr_in6 *) addr;
+ if (0 == ntohs (i6->sin6_port))
+ return; /* Port = 0 means unmapped, ignore these for XU. */
+ memset (&u6,
+ 0,
+ sizeof(u6));
+ u6.options = htonl (plugin->myoptions);
+ u6.ipv6_addr = i6->sin6_addr;
+ u6.u6_port = i6->sin6_port;
+ arg = &u6;
+ args = sizeof (struct IPv6XuAddress);
+ break;
+ }
+ default:
+ GNUNET_break (0);
+ return;
+ }
+ /* modify our published address list */
+ /* TODO: use 'ac' here in the future... */
+ address = GNUNET_HELLO_address_allocate (plugin->env->my_identity,
+ PLUGIN_NAME,
+ arg,
+ args,
+ GNUNET_HELLO_ADDRESS_INFO_NONE);
+ plugin->env->notify_address (plugin->env->cls,
+ add_remove,
+ address);
+ GNUNET_HELLO_address_free (address);
+}
+
+
+/* ********************* Finding sessions ******************* */
+
+
+/**
+ * Closure for #session_cmp_it().
+ */
+struct GNUNET_ATS_SessionCompareContext
+{
+ /**
+ * Set to session matching the address.
+ */
+ struct GNUNET_ATS_Session *res;
+
+ /**
+ * Address we are looking for.
+ */
+ const struct GNUNET_HELLO_Address *address;
+};
+
+
+/**
+ * Find a session with a matching address.
+ *
+ * @param cls the `struct GNUNET_ATS_SessionCompareContext *`
+ * @param key peer identity (unused)
+ * @param value the `struct GNUNET_ATS_Session *`
+ * @return #GNUNET_NO if we found the session, #GNUNET_OK if not
+ */
+static int
+session_cmp_it (void *cls,
+ const struct GNUNET_PeerIdentity *key,
+ void *value)
+{
+ struct GNUNET_ATS_SessionCompareContext *cctx = cls;
+ struct GNUNET_ATS_Session *s = value;
+
+ (void) key;
+ if (0 == GNUNET_HELLO_address_cmp (s->address,
+ cctx->address))
+ {
+ GNUNET_assert (GNUNET_NO == s->in_destroy);
+ cctx->res = s;
+ return GNUNET_NO;
+ }
+ return GNUNET_OK;
+}
+
+
+/**
+ * Locate an existing session the transport service is using to
+ * send data to another peer. Performs some basic sanity checks
+ * on the address and then tries to locate a matching session.
+ *
+ * @param cls the plugin
+ * @param address the address we should locate the session by
+ * @return the session if it exists, or NULL if it is not found
+ */
+static struct GNUNET_ATS_Session *
+xu_plugin_lookup_session (void *cls,
+ const struct GNUNET_HELLO_Address *address)
+{
+ struct Plugin *plugin = cls;
+ const struct IPv6XuAddress *xu_a6;
+ const struct IPv4XuAddress *xu_a4;
+ struct GNUNET_ATS_SessionCompareContext cctx;
+
+ if (NULL == address->address)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ if (sizeof(struct IPv4XuAddress) == address->address_length)
+ {
+ if (NULL == plugin->sockv4)
+ return NULL;
+ xu_a4 = (const struct IPv4XuAddress *) address->address;
+ if (0 == xu_a4->u4_port)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ }
+ else if (sizeof(struct IPv6XuAddress) == address->address_length)
+ {
+ if (NULL == plugin->sockv6)
+ return NULL;
+ xu_a6 = (const struct IPv6XuAddress *) address->address;
+ if (0 == xu_a6->u6_port)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ }
+ else
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+
+ /* check if session already exists */
+ cctx.address = address;
+ cctx.res = NULL;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Looking for existing session for peer `%s' with address `%s'\n",
+ GNUNET_i2s (&address->peer),
+ xu_address_to_string (plugin,
+ address->address,
+ address->address_length));
+ GNUNET_CONTAINER_multipeermap_get_multiple (plugin->sessions,
+ &address->peer,
+ &session_cmp_it,
+ &cctx);
+ if (NULL == cctx.res)
+ return NULL;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Found existing session %p\n",
+ cctx.res);
+ return cctx.res;
+}
+
+
+/* ********************** Timeout ****************** */
+
+
+/**
+ * Increment session timeout due to activity.
+ *
+ * @param s session to reschedule timeout activity for
+ */
+static void
+reschedule_session_timeout (struct GNUNET_ATS_Session *s)
+{
+ if (GNUNET_YES == s->in_destroy)
+ return;
+ GNUNET_assert (NULL != s->timeout_task);
+ s->timeout = GNUNET_TIME_relative_to_absolute (XU_SESSION_TIME_OUT);
+}
+
+
+
+/**
+ * Function that will be called whenever the transport service wants to
+ * notify the plugin that a session is still active and in use and
+ * therefore the session timeout for this session has to be updated
+ *
+ * @param cls closure with the `struct Plugin`
+ * @param peer which peer was the session for
+ * @param session which session is being updated
+ */
+static void
+xu_plugin_update_session_timeout (void *cls,
+ const struct GNUNET_PeerIdentity *peer,
+ struct GNUNET_ATS_Session *session)
+{
+ struct Plugin *plugin = cls;
+
+ if (GNUNET_YES !=
+ GNUNET_CONTAINER_multipeermap_contains_value (plugin->sessions,
+ peer,
+ session))
+ {
+ GNUNET_break (0);
+ return;
+ }
+ /* Reschedule session timeout */
+ reschedule_session_timeout (session);
+}
+
+
+/* ************************* Sending ************************ */
+
+
+/**
+ * We failed to transmit a message via XU. Generate
+ * a descriptive error message.
+ *
+ * @param plugin our plugin
+ * @param sa target address we were trying to reach
+ * @param slen number of bytes in @a sa
+ * @param error the errno value returned from the sendto() call
+ */
+static void
+analyze_send_error (struct Plugin *plugin,
+ const struct sockaddr *sa,
+ socklen_t slen,
+ int error)
+{
+ enum GNUNET_ATS_Network_Type type;
+