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Diffstat (limited to 'src/transport/plugin_transport_xu.c')
| -rw-r--r-- | src/transport/plugin_transport_xu.c | 2490 |
1 files changed, 2490 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..59e00f80eb --- /dev/null +++ b/src/transport/plugin_transport_xu.c @@ -0,0 +1,2490 @@ +/* + 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 Affero General Public License as published + by the Free Software Foundation, either version 3 of the License, + 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 + Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +/** + * @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; + + type = plugin->env->get_address_type (plugin->env->cls, + sa, + slen); + if ( ( (GNUNET_ATS_NET_LAN == type) || + (GNUNET_ATS_NET_WAN == type) ) && + ( (ENETUNREACH == errno) || + (ENETDOWN == errno) ) ) + { + if (slen == sizeof (struct sockaddr_in)) + { + /* IPv4: "Network unreachable" or "Network down" + * + * This indicates we do not have connectivity + */ + LOG (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, + _("XU could not transmit message to `%s': " + "Network seems down, please check your network configuration\n"), + GNUNET_a2s (sa, + slen)); + } + if (slen == sizeof (struct sockaddr_in6)) + { + /* IPv6: "Network unreachable" or "Network down" + * + * This indicates that this system is IPv6 enabled, but does not + * have a valid global IPv6 address assigned or we do not have + * connectivity + */ + LOG (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK, + _("XU could not transmit IPv6 message! " + "Please check your network configuration and disable IPv6 if your " + "connection does not have a global IPv6 address\n")); + } + } + else + { + LOG (GNUNET_ERROR_TYPE_WARNING, + "XU could not transmit message to `%s': `%s'\n", + GNUNET_a2s (sa, + slen), + STRERROR (error)); + } +} + + + + +/** + * Function that can be used by the transport service to transmit a + * message using the plugin. Note that in the case of a peer + * disconnecting, the continuation MUST be called prior to the + * disconnect notification itself. This function will be called with + * this peer's HELLO message to initiate a fresh connection to another + * peer. + * + * @param cls closure + * @param s which session must be used + * @param msgbuf the message to transmit + * @param msgbuf_size number of bytes in @a msgbuf + * @param priority how important is the message (most plugins will + * ignore message priority and just FIFO) + * @param to how long to wait at most for the transmission (does not + * require plugins to discard the message after the timeout, + * just advisory for the desired delay; most plugins will ignore + * this as well) + * @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...); can be NULL + * @param cont_cls closure for @a cont + * @return number of bytes used (on the physical network, with overheads); + * -1 on hard errors (i.e. address invalid); 0 is a legal value + * and does NOT mean that the message was not transmitted (DV) + */ +static ssize_t +xu_plugin_send (void *cls, + struct GNUNET_ATS_Session *s, + const char *msgbuf, + size_t msgbuf_size, + unsigned int priority, + struct GNUNET_TIME_Relative to, + GNUNET_TRANSPORT_TransmitContinuation cont, + void *cont_cls) +{ + struct Plugin *plugin = cls; + size_t xumlen = msgbuf_size + sizeof(struct XUMessage); + struct XUMessage *xu; + char mbuf[xumlen] GNUNET_ALIGN; + ssize_t sent; + socklen_t slen; + const struct sockaddr *a; + const struct IPv4XuAddress *u4; + struct sockaddr_in a4; + const struct IPv6XuAddress *u6; + struct sockaddr_in6 a6; + struct GNUNET_NETWORK_Handle *sock; + + (void) priority; + (void) to; + if ( (sizeof(struct IPv6XuAddress) == s->address->address_length) && + (NULL == plugin->sockv6) ) + return GNUNET_SYSERR; + if ( (sizeof(struct IPv4XuAddress) == s->address->address_length) && + (NULL == plugin->sockv4) ) + return GNUNET_SYSERR; + if (xumlen >= GNUNET_MAX_MESSAGE_SIZE) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + if (GNUNET_YES != + GNUNET_CONTAINER_multipeermap_contains_value (plugin->sessions, + &s->target, + s)) + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + LOG (GNUNET_ERROR_TYPE_DEBUG, + "XU transmits %u-byte message to `%s' using address `%s'\n", + xumlen, + GNUNET_i2s (&s->target), + xu_address_to_string (plugin, + s->address->address, + s->address->address_length)); + xu = (struct XUMessage *) mbuf; + xu->header.size = htons (xumlen); + xu->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_XU_MESSAGE); + xu->reserved = htonl (0); + xu->sender = *plugin->env->my_identity; + GNUNET_memcpy (&xu[1], + msgbuf, + msgbuf_size); + + if (sizeof (struct IPv4XuAddress) == s->address->address_length) + { + u4 = s->address->address; + 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; + a = (const struct sockaddr *) &a4; + slen = sizeof (a4); + sock = plugin->sockv4; + } + else if (sizeof (struct IPv6XuAddress) == s->address->address_length) + { + u6 = s->address->address; + 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; + a = (const struct sockaddr *) &a6; + slen = sizeof (a6); + sock = plugin->sockv6; + } + else + { + GNUNET_break (0); + return GNUNET_SYSERR; + } + + sent = GNUNET_NETWORK_socket_sendto (sock, + mbuf, + xumlen, + a, + slen); + s->last_transmit_time + = GNUNET_TIME_absolute_max (GNUNET_TIME_absolute_get (), + s->last_transmit_time); + + if (GNUNET_SYSERR == sent) + { + /* Failure */ + analyze_send_error (plugin, + a, + slen, + errno); + GNUNET_STATISTICS_update (plugin->env->stats, + "# XU, total, bytes, sent, failure", + sent, + GNUNET_NO); + GNUNET_STATISTICS_update (plugin->env->stats, + "# XU, total, messages, sent, failure", + 1, + GNUNET_NO); + return GNUNET_SYSERR; + } + /* Success */ + LOG (GNUNET_ERROR_TYPE_DEBUG, + "XU transmitted %u-byte message to `%s' `%s' (%d: %s)\n", + (unsigned int) (msgbuf_size), + GNUNET_i2s (&s->target), + GNUNET_a2s (a, + slen), + (int ) sent, + (sent < 0) ? STRERROR (errno) : "ok"); + GNUNET_STATISTICS_update (plugin->env->stats, + "# XU, total, bytes, sent, success", + sent, + GNUNET_NO); + GNUNET_STATISTICS_update (plugin->env->stats, + "# XU, total, messages, sent, success", + 1, + GNUNET_NO); + cont (cont_cls, + &s->target, + GNUNET_OK, + msgbuf_size, + xumlen); + notify_session_monitor (s->plugin, + s, + GNUNET_TRANSPORT_SS_UPDATE); + return xumlen; +} + + +/* ********************** Receiving ********************** */ + + +/** + * Functions with this signature are called whenever we need to close + * a session due to a disconnect or failure to establish a connection. + * + * @param cls closure with the `struct Plugin` + * @param s session to close down + * @return #GNUNET_OK on success + */ +static int +xu_disconnect_session (void *cls, + struct GNUNET_ATS_Session *s) +{ + struct Plugin *plugin = cls; + + GNUNET_assert (GNUNET_YES != s->in_destroy); + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Session %p to peer `%s' at address %s ended\n", + s, + GNUNET_i2s (&s->target), + xu_address_to_string (plugin, + s->address->address, + s->address->address_length)); + if (NULL != s->timeout_task) + { + GNUNET_SCHEDULER_cancel (s->timeout_task); + s->timeout_task = NULL; + } + GNUNET_assert (GNUNET_YES == + GNUNET_CONTAINER_multipeermap_remove (plugin->sessions, + &s->target, + s)); + s->in_destroy = GNUNET_YES; + notify_session_monitor (s->plugin, + s, + GNUNET_TRANSPORT_SS_DONE); + plugin->env->session_end (plugin->env->cls, + s->address, + s); + GNUNET_STATISTICS_set (plugin->env->stats, + "# XU sessions active", + GNUNET_CONTAINER_multipeermap_size (plugin->sessions), + GNUNET_NO); + if (0 == s->rc) + free_session (s); + return GNUNET_OK; +} + + +/** + * Message tokenizer has broken up an incomming message. Pass it on + * to the service. + * + * @param cls the `struct GNUNET_ATS_Session *` + * @param hdr the actual message + * @return #GNUNET_OK (always) + */ +static int +process_inbound_tokenized_messages (void *cls, + const struct GNUNET_MessageHeader *hdr) +{ + struct GNUNET_ATS_Session *session = cls; + struct Plugin *plugin = session->plugin; + + if (GNUNET_YES == session->in_destroy) + return GNUNET_OK; + reschedule_session_timeout (session); + session->flow_delay_for_other_peer + = plugin->env->receive (plugin->env->cls, + session->address, + session, + hdr); + return GNUNET_OK; +} + + +/** + * Destroy a session, plugin is being unloaded. + * + * @param cls the `struct Plugin` + * @param key hash of public key of target peer + * @param value a `struct PeerSession *` to clean up + * @return #GNUNET_OK (continue to iterate) + */ +static int +disconnect_and_free_it (void *cls, + const struct GNUNET_PeerIdentity *key, + void *value) +{ + struct Plugin *plugin = cls; + + (void) key; + xu_disconnect_session (plugin, + value); + return GNUNET_OK; +} + + +/** + * Disconnect from a remote node. Clean up session if we have one for + * this peer. + * + * @param cls closure for this call (should be handle to Plugin) + * @param target the peeridentity of the peer to disconnect + * @return #GNUNET_OK on success, #GNUNET_SYSERR if the operation failed + */ +static void +xu_disconnect (void *cls, + const struct GNUNET_PeerIdentity *target) +{ + struct Plugin *plugin = cls; + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Disconnecting from peer `%s'\n", + GNUNET_i2s (target)); + GNUNET_CONTAINER_multipeermap_get_multiple (plugin->sessions, + target, + &disconnect_and_free_it, + plugin); +} + + +/** + * Session was idle, so disconnect it. + * + * @param cls the `struct GNUNET_ATS_Session` to time out + */ +static void +session_timeout (void *cls) +{ + struct GNUNET_ATS_Session *s = cls; + struct Plugin *plugin = s->plugin; + struct GNUNET_TIME_Relative left; + + s->timeout_task = NULL; + left = GNUNET_TIME_absolute_get_remaining (s->timeout); + if (left.rel_value_us > 0) + { + /* not actually our turn yet, but let's at least update + the monitor, it may think we're about to die ... */ + notify_session_monitor (s->plugin, + s, + GNUNET_TRANSPORT_SS_UPDATE); + s->timeout_task = GNUNET_SCHEDULER_add_delayed (left, + &session_timeout, + s); + return; + } + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Session %p was idle for %s, disconnecting\n", + s, + GNUNET_STRINGS_relative_time_to_string (XU_SESSION_TIME_OUT, + GNUNET_YES)); + /* call session destroy function */ + xu_disconnect_session (plugin, + s); +} + + +/** + * Allocate a new session for the given endpoint address. + * Note that this function does not inform the service + * of the new session, this is the responsibility of the + * caller (if needed). + * + * @param cls the `struct Plugin` + * @param address address of the other peer to use + * @param network_type network type the address belongs to + * @return NULL on error, otherwise session handle + */ +static struct GNUNET_ATS_Session * +xu_plugin_create_session (void *cls, + const struct GNUNET_HELLO_Address *address, + enum GNUNET_ATS_Network_Type network_type) +{ + struct Plugin *plugin = cls; + struct GNUNET_ATS_Session *s; + + s = GNUNET_new (struct GNUNET_ATS_Session); + s->mst = GNUNET_MST_create (&process_inbound_tokenized_messages, + s); + s->plugin = plugin; + s->address = GNUNET_HELLO_address_copy (address); + s->target = address->peer; + s->last_transmit_time = GNUNET_TIME_absolute_get (); + s->last_expected_ack_delay = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, + 250); + s->last_expected_msg_delay = GNUNET_TIME_UNIT_MILLISECONDS; + s->flow_delay_from_other_peer = GNUNET_TIME_UNIT_ZERO; + s->flow_delay_for_other_peer = GNUNET_TIME_UNIT_ZERO; + s->timeout = GNUNET_TIME_relative_to_absolute (XU_SESSION_TIME_OUT); + s->timeout_task = GNUNET_SCHEDULER_add_delayed (XU_SESSION_TIME_OUT, + &session_timeout, + s); + s->scope = network_type; + + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Creating new session %p for peer `%s' address `%s'\n", + s, + GNUNET_i2s (&address->peer), + xu_address_to_string (plugin, + address->address, + address->address_length)); + GNUNET_assert (GNUNET_OK == + GNUNET_CONTAINER_multipeermap_put (plugin->sessions, + &s->target, + s, + GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE)); + GNUNET_STATISTICS_set (plugin->env->stats, + "# XU sessions active", + GNUNET_CONTAINER_multipeermap_size (plugin->sessions), + GNUNET_NO); + notify_session_monitor (plugin, + s, + GNUNET_TRANSPORT_SS_INIT); + return s; +} + + +/** + * Creates a new outbound session the transport service will use to + * send data to the peer. + * + * @param cls the `struct Plugin *` + * @param address the address + * @return the session or NULL of max connections exceeded + */ +static struct GNUNET_ATS_Session * +xu_plugin_get_session (void *cls, + const struct GNUNET_HELLO_Address *address) +{ + struct Plugin *plugin = cls; + struct GNUNET_ATS_Session *s; + enum GNUNET_ATS_Network_Type network_type = GNUNET_ATS_NET_UNSPECIFIED; + const struct IPv4XuAddress *xu_v4; + const struct IPv6XuAddress *xu_v6; + + if (NULL == address) + { + GNUNET_break (0); + return NULL; + } + if ( (address->address_length != sizeof(struct IPv4XuAddress)) && + (address->address_length != sizeof(struct IPv6XuAddress)) ) + { + GNUNET_break_op (0); + return NULL; + } + if (NULL != (s = xu_plugin_lookup_session (cls, + address))) + return s; + + /* need to create new session */ + if (sizeof (struct IPv4XuAddress) == address->address_length) + { + struct sockaddr_in v4; + + xu_v4 = (const struct IPv4XuAddress *) address->address; + memset (&v4, '\0', sizeof (v4)); + v4.sin_family = AF_INET; +#if HAVE_SOCKADDR_IN_SIN_LEN + v4.sin_len = sizeof (struct sockaddr_in); +#endif + v4.sin_port = xu_v4->u4_port; + v4.sin_addr.s_addr = xu_v4->ipv4_addr; + network_type = plugin->env->get_address_type (plugin->env->cls, + (const struct sockaddr *) &v4, + sizeof (v4)); + } + if (sizeof (struct IPv6XuAddress) == address->address_length) + { + struct sockaddr_in6 v6; + + xu_v6 = (const struct IPv6XuAddress *) address->address; + memset (&v6, '\0', sizeof (v6)); + v6.sin6_family = AF_INET6; +#if HAVE_SOCKADDR_IN_SIN_LEN + v6.sin6_len = sizeof (struct sockaddr_in6); +#endif + v6.sin6_port = xu_v6->u6_port; + v6.sin6_addr = xu_v6->ipv6_addr; + network_type = plugin->env->get_address_type (plugin->env->cls, + (const struct sockaddr *) &v6, + sizeof (v6)); + } + GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network_type); + return xu_plugin_create_session (cls, + address, + network_type); +} + + +/** + * We've received a XU Message. Process it (pass contents to main service). + * + * @param plugin plugin context + * @param msg the message + * @param xu_addr sender address + * @param xu_addr_len number of bytes in @a xu_addr + * @param network_type network type the address belongs to + */ +static void +process_xu_message (struct Plugin *plugin, + const struct XUMessage *msg, + const union XuAddress *xu_addr, + size_t xu_addr_len, + enum GNUNET_ATS_Network_Type network_type) +{ + struct GNUNET_ATS_Session *s; + struct GNUNET_HELLO_Address *address; + + GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != network_type); + if (0 != ntohl (msg->reserved)) + { + GNUNET_break_op(0); + return; + } + if (ntohs (msg->header.size) + < sizeof(struct GNUNET_MessageHeader) + sizeof(struct XUMessage)) + { + GNUNET_break_op(0); + return; + } + + address = GNUNET_HELLO_address_allocate (&msg->sender, + PLUGIN_NAME, + xu_addr, + xu_addr_len, + GNUNET_HELLO_ADDRESS_INFO_NONE); + if (NULL == + (s = xu_plugin_lookup_session (plugin, + address))) + { + s = xu_plugin_create_session (plugin, + address, + network_type); + plugin->env->session_start (plugin->env->cls, + address, + s, + s->scope); + notify_session_monitor (plugin, + s, + GNUNET_TRANSPORT_SS_UP); + } + GNUNET_free (address); + + s->rc++; + GNUNET_MST_from_buffer (s->mst, + (const char *) &msg[1], + ntohs (msg->header.size) - sizeof(struct XUMessage), + GNUNET_YES, + GNUNET_NO); + s->rc--; + if ( (0 == s->rc) && + (GNUNET_YES == s->in_destroy) ) + free_session (s); +} + + +/** + * Read and process a message from the given socket. + * + * @param plugin the overall plugin + * @param rsock socket to read from + */ +static void +xu_select_read (struct Plugin *plugin, + struct GNUNET_NETWORK_Handle *rsock) +{ + socklen_t fromlen; + struct sockaddr_storage addr; + char buf[65536] GNUNET_ALIGN; + ssize_t size; + const struct GNUNET_MessageHeader *msg; + struct IPv4XuAddress v4; + struct IPv6XuAddress v6; + const struct sockaddr *sa; + const struct sockaddr_in *sa4; + const struct sockaddr_in6 *sa6; + const union XuAddress *int_addr; + size_t int_addr_len; + enum GNUNET_ATS_Network_Type network_type; + + fromlen = sizeof (addr); + memset (&addr, + 0, + sizeof(addr)); + size = GNUNET_NETWORK_socket_recvfrom (rsock, + buf, + sizeof (buf), + (struct sockaddr *) &addr, + &fromlen); + sa = (const struct sockaddr *) &addr; +#if MINGW + /* On SOCK_DGRAM XU sockets recvfrom might fail with a + * WSAECONNRESET error to indicate that previous sendto() (yes, sendto!) + * on this socket has failed. + * Quote from MSDN: + * WSAECONNRESET - The virtual circuit was reset by the remote side + * executing a hard or abortive close. The application should close + * the socket; it is no longer usable. On a XU-datagram socket this + * error indicates a previous send operation resulted in an ICMP Port + * Unreachable message. + */ + if ( (-1 == size) && + (ECONNRESET == errno) ) + return; +#endif + if (-1 == size) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "XU failed to receive data: %s\n", + STRERROR (errno)); + /* Connection failure or something. Not a protocol violation. */ + return; + } + + /* Check if this is a STUN packet */ + if (GNUNET_NO != + GNUNET_NAT_stun_handle_packet (plugin->nat, + (const struct sockaddr *) &addr, + fromlen, + buf, + size)) + return; /* was STUN, do not process further */ + + if (((size_t) size) < sizeof(struct GNUNET_MessageHeader)) + { + LOG (GNUNET_ERROR_TYPE_WARNING, + "XU got %u bytes from %s, which is not enough for a GNUnet message header\n", + (unsigned int ) size, + GNUNET_a2s (sa, + fromlen)); + /* _MAY_ be a connection failure (got partial message) */ + /* But it _MAY_ also be that the other side uses non-GNUnet protocol. */ + GNUNET_break_op (0); + return; + } + + msg = (const struct GNUNET_MessageHeader *) buf; + LOG (GNUNET_ERROR_TYPE_DEBUG, + "XU received %u-byte message from `%s' type %u\n", + (unsigned int) size, + GNUNET_a2s (sa, + fromlen), + ntohs (msg->type)); + if (size != ntohs (msg->size)) + { + LOG (GNUNET_ERROR_TYPE_WARNING, + "XU malformed message (size %u) header from %s\n", + (unsigned int) size, + GNUNET_a2s (sa, + fromlen)); + GNUNET_break_op (0); + return; + } + GNUNET_STATISTICS_update (plugin->env->stats, + "# XU, total bytes received", + size, + GNUNET_NO); + network_type = plugin->env->get_address_type (plugin->env->cls, + sa, + fromlen); + switch (sa->sa_family) + { + case AF_INET: + sa4 = (const struct sockaddr_in *) &addr; + v4.options = 0; + v4.ipv4_addr = sa4->sin_addr.s_addr; + v4.u4_port = sa4->sin_port; + int_addr = (union XuAddress *) &v4; + int_addr_len = sizeof (v4); + break; + case AF_INET6: + sa6 = (const struct sockaddr_in6 *) &addr; + v6.options = 0; + v6.ipv6_addr = sa6->sin6_addr; + v6.u6_port = sa6->sin6_port; + int_addr = (union XuAddress *) &v6; + int_addr_len = sizeof (v6); + break; + default: + GNUNET_break (0); + return; + } + + switch (ntohs (msg->type)) + { + case GNUNET_MESSAGE_TYPE_TRANSPORT_XU_MESSAGE: + if (ntohs (msg->size) < sizeof(struct XUMessage)) + { + GNUNET_break_op(0); + return; + } + process_xu_message (plugin, + (const struct XUMessage *) msg, + int_addr, + int_addr_len, + network_type); + return; + default: + GNUNET_break_op(0); + return; + } +} + + +/* ***************** Event loop (part 2) *************** */ + + +/** + * 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) +{ + struct Plugin *plugin = cls; + const struct GNUNET_SCHEDULER_TaskContext *tc; + + plugin->select_task_v4 = NULL; + if (NULL == plugin->sockv4) + return; + tc = GNUNET_SCHEDULER_get_task_context (); + if ( (0 != (tc->reason & GNUNET_SCHEDULER_REASON_READ_READY)) && + (GNUNET_NETWORK_fdset_isset (tc->read_ready, + plugin->sockv4)) ) + xu_select_read (plugin, + plugin->sockv4); + schedule_select_v4 (plugin); +} + + +/** + * 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) +{ + struct Plugin *plugin = cls; + const struct GNUNET_SCHEDULER_TaskContext *tc; + + plugin->select_task_v6 = NULL; + if (NULL == plugin->sockv6) + return; + tc = GNUNET_SCHEDULER_get_task_context (); + if ( (0 != (tc->reason & GNUNET_SCHEDULER_REASON_READ_READY)) && + (GNUNET_NETWORK_fdset_isset (tc->read_ready, + plugin->sockv6)) ) + xu_select_read (plugin, + plugin->sockv6); + schedule_select_v6 (plugin); +} + + +/* ******************* Initialization *************** */ + + +/** + * Setup the XU sockets (for IPv4 and IPv6) for the plugin. + * + * @param plugin the plugin to initialize + * @param bind_v6 IPv6 address to bind to (can be NULL, for 'any') + * @param bind_v4 IPv4 address to bind to (can be NULL, for 'any') + * @return number of sockets that were successfully bound + */ +static unsigned int +setup_sockets (struct Plugin *plugin, + const struct sockaddr_in6 *bind_v6, + const struct sockaddr_in *bind_v4) +{ + int tries; + unsigned int sockets_created = 0; + struct sockaddr_in6 server_addrv6; + struct sockaddr_in server_addrv4; + const struct sockaddr *server_addr; + const struct sockaddr *addrs[2]; + socklen_t addrlens[2]; + socklen_t addrlen; + int eno; + + /* Create IPv6 socket */ + eno = EINVAL; + if (GNUNET_YES == plugin->enable_ipv6) + { + plugin->sockv6 = GNUNET_NETWORK_socket_create (PF_INET6, + SOCK_DGRAM, + 0); + if (NULL == plugin->sockv6) + { + LOG (GNUNET_ERROR_TYPE_INFO, + _("Disabling IPv6 since it is not supported on this system!\n")); + plugin->enable_ipv6 = GNUNET_NO; + } + else + { + memset (&server_addrv6, + 0, + sizeof(struct sockaddr_in6)); +#if HAVE_SOCKADDR_IN_SIN_LEN + server_addrv6.sin6_len = sizeof (struct sockaddr_in6); +#endif + server_addrv6.sin6_family = AF_INET6; + if (NULL != bind_v6) + server_addrv6.sin6_addr = bind_v6->sin6_addr; + else + server_addrv6.sin6_addr = in6addr_any; + + if (0 == plugin->port) /* autodetect */ + server_addrv6.sin6_port + = htons (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, + 33537) + + 32000); + else + server_addrv6.sin6_port = htons (plugin->port); + addrlen = sizeof (struct sockaddr_in6); + server_addr = (const struct sockaddr *) &server_addrv6; + + tries = 0; + while (tries < 10) + { + LOG(GNUNET_ERROR_TYPE_DEBUG, + "Binding to IPv6 `%s'\n", + GNUNET_a2s (server_addr, + addrlen)); + /* binding */ + if (GNUNET_OK == + GNUNET_NETWORK_socket_bind (plugin->sockv6, + server_addr, + addrlen)) + break; + eno = errno; + if (0 != plugin->port) + { + tries = 10; /* fail immediately */ + break; /* bind failed on specific port */ + } + /* autodetect */ + server_addrv6.sin6_port + = htons (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, + 33537) + + 32000); + tries++; + } + if (tries >= 10) + { + GNUNET_NETWORK_socket_close (plugin->sockv6); + plugin->enable_ipv6 = GNUNET_NO; + plugin->sockv6 = NULL; + } + else + { + plugin->port = ntohs (server_addrv6.sin6_port); + } + if (NULL != plugin->sockv6) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "IPv6 XU socket created listinging at %s\n", + GNUNET_a2s (server_addr, + addrlen)); + addrs[sockets_created] = server_addr; + addrlens[sockets_created] = addrlen; + sockets_created++; + } + else + { + LOG (GNUNET_ERROR_TYPE_WARNING, + _("Failed to bind XU socket to %s: %s\n"), + GNUNET_a2s (server_addr, + addrlen), + STRERROR (eno)); + } + } + } + + /* Create IPv4 socket */ + eno = EINVAL; + plugin->sockv4 = GNUNET_NETWORK_socket_create (PF_INET, + SOCK_DGRAM, + 0); + if (NULL == plugin->sockv4) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, + "socket"); + LOG (GNUNET_ERROR_TYPE_INFO, + _("Disabling IPv4 since it is not supported on this system!\n")); + plugin->enable_ipv4 = GNUNET_NO; + } + else + { + memset (&server_addrv4, + 0, + sizeof(struct sockaddr_in)); +#if HAVE_SOCKADDR_IN_SIN_LEN + server_addrv4.sin_len = sizeof (struct sockaddr_in); +#endif + server_addrv4.sin_family = AF_INET; + if (NULL != bind_v4) + server_addrv4.sin_addr = bind_v4->sin_addr; + else + server_addrv4.sin_addr.s_addr = INADDR_ANY; + + if (0 == plugin->port) + /* autodetect */ + server_addrv4.sin_port + = htons (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, + 33537) + + 32000); + else + server_addrv4.sin_port = htons (plugin->port); + + addrlen = sizeof (struct sockaddr_in); + server_addr = (const struct sockaddr *) &server_addrv4; + + tries = 0; + while (tries < 10) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Binding to IPv4 `%s'\n", + GNUNET_a2s (server_addr, + addrlen)); + + /* binding */ + if (GNUNET_OK == + GNUNET_NETWORK_socket_bind (plugin->sockv4, + server_addr, + addrlen)) + break; + eno = errno; + if (0 != plugin->port) + { + tries = 10; /* fail */ + break; /* bind failed on specific port */ + } + + /* autodetect */ + server_addrv4.sin_port + = htons (GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, + 33537) + + 32000); + tries++; + } + if (tries >= 10) + { + GNUNET_NETWORK_socket_close (plugin->sockv4); + plugin->enable_ipv4 = GNUNET_NO; + plugin->sockv4 = NULL; + } + else + { + plugin->port = ntohs (server_addrv4.sin_port); + } + + if (NULL != plugin->sockv4) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "IPv4 socket created on port %s\n", + GNUNET_a2s (server_addr, + addrlen)); + addrs[sockets_created] = server_addr; + addrlens[sockets_created] = addrlen; + sockets_created++; + } + else + { + LOG (GNUNET_ERROR_TYPE_ERROR, + _("Failed to bind XU socket to %s: %s\n"), + GNUNET_a2s (server_addr, + addrlen), + STRERROR (eno)); + } + } + + if (0 == sockets_created) + { + LOG (GNUNET_ERROR_TYPE_WARNING, + _("Failed to open XU sockets\n")); + return 0; /* No sockets created, return */ + } + schedule_select_v4 (plugin); + schedule_select_v6 (plugin); + plugin->nat = GNUNET_NAT_register (plugin->env->cfg, + "transport-xu", + IPPROTO_UDP, + sockets_created, + addrs, + addrlens, + &xu_nat_port_map_callback, + NULL, + plugin); + return sockets_created; +} + + +/** + * The exported method. Makes the core api available via a global and + * returns the xu transport API. + * + * @param cls our `struct GNUNET_TRANSPORT_PluginEnvironment` + * @return our `struct GNUNET_TRANSPORT_PluginFunctions` + */ +void * +libgnunet_plugin_transport_xu_init (void *cls) +{ + struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; + struct GNUNET_TRANSPORT_PluginFunctions *api; + struct Plugin *p; + unsigned long long port; + unsigned long long aport; + int enable_v6; + char *bind4_address; + char *bind6_address; + struct sockaddr_in server_addrv4; + struct sockaddr_in6 server_addrv6; + unsigned int res; + int have_bind4; + int have_bind6; + + if (NULL == env->receive) + { + /* run in 'stub' mode (i.e. as part of gnunet-peerinfo), don't fully + initialze the plugin or the API */ + api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); + api->cls = NULL; + api->address_pretty_printer = &xu_plugin_address_pretty_printer; + api->address_to_string = &xu_address_to_string; + api->string_to_address = &xu_string_to_address; + return api; + } + + /* Get port number: port == 0 : autodetect a port, + * > 0 : use this port, not given : 2086 default */ + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_number (env->cfg, + "transport-xu", + "PORT", + &port)) + port = 2086; + if (port > 65535) + { + GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, + "transport-xu", + "PORT", + _("must be in [0,65535]")); + return NULL; + } + if (GNUNET_OK != + GNUNET_CONFIGURATION_get_value_number (env->cfg, + "transport-xu", + "ADVERTISED_PORT", + &aport)) + aport = port; + if (aport > 65535) + { + GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, + "transport-xu", + "ADVERTISED_PORT", + _("must be in [0,65535]")); + return NULL; + } + + if (GNUNET_YES == + GNUNET_CONFIGURATION_get_value_yesno (env->cfg, + "nat", + "DISABLEV6")) + enable_v6 = GNUNET_NO; + else + enable_v6 = GNUNET_YES; + + have_bind4 = GNUNET_NO; + memset (&server_addrv4, + 0, + sizeof (server_addrv4)); + if (GNUNET_YES == + GNUNET_CONFIGURATION_get_value_string (env->cfg, + "transport-xu", + "BINDTO", + &bind4_address)) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Binding XU plugin to specific address: `%s'\n", + bind4_address); + if (1 != inet_pton (AF_INET, + bind4_address, + &server_addrv4.sin_addr)) + { + GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, + "transport-xu", + "BINDTO", + _("must be valid IPv4 address")); + GNUNET_free (bind4_address); + return NULL; + } + have_bind4 = GNUNET_YES; + } + GNUNET_free_non_null (bind4_address); + have_bind6 = GNUNET_NO; + memset (&server_addrv6, + 0, + sizeof (server_addrv6)); + if (GNUNET_YES == + GNUNET_CONFIGURATION_get_value_string (env->cfg, + "transport-xu", + "BINDTO6", + &bind6_address)) + { + LOG (GNUNET_ERROR_TYPE_DEBUG, + "Binding xu plugin to specific address: `%s'\n", + bind6_address); + if (1 != inet_pton (AF_INET6, + bind6_address, + &server_addrv6.sin6_addr)) + { + GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, + "transport-xu", + "BINDTO6", + _("must be valid IPv6 address")); + GNUNET_free (bind6_address); + return NULL; + } + have_bind6 = GNUNET_YES; + } + GNUNET_free_non_null (bind6_address); + + p = GNUNET_new (struct Plugin); + p->port = port; + p->aport = aport; + p->enable_ipv6 = enable_v6; + p->enable_ipv4 = GNUNET_YES; /* default */ + p->env = env; + p->sessions = GNUNET_CONTAINER_multipeermap_create (16, + GNUNET_NO); + res = setup_sockets (p, + (GNUNET_YES == have_bind6) ? &server_addrv6 : NULL, + (GNUNET_YES == have_bind4) ? &server_addrv4 : NULL); + if ( (0 == res) || + ( (NULL == p->sockv4) && + (NULL == p->sockv6) ) ) + { + LOG (GNUNET_ERROR_TYPE_ERROR, + _("Failed to create XU network sockets\n")); + GNUNET_CONTAINER_multipeermap_destroy (p->sessions); + if (NULL != p->nat) + GNUNET_NAT_unregister (p->nat); + GNUNET_free (p); + return NULL; + } + + api = GNUNET_new (struct GNUNET_TRANSPORT_PluginFunctions); + api->cls = p; + api->disconnect_session = &xu_disconnect_session; + api->query_keepalive_factor = &xu_query_keepalive_factor; + api->disconnect_peer = &xu_disconnect; + api->address_pretty_printer = &xu_plugin_address_pretty_printer; + api->address_to_string = &xu_address_to_string; + api->string_to_address = &xu_string_to_address; + api->check_address = &xu_plugin_check_address; + api->get_session = &xu_plugin_get_session; + api->send = &xu_plugin_send; + api->get_network = &xu_plugin_get_network; + api->get_network_for_address = &xu_plugin_get_network_for_address; + api->update_session_timeout = &xu_plugin_update_session_timeout; + api->setup_monitor = &xu_plugin_setup_monitor; + return api; +} + + +/** + * The exported method. Makes the core api available via a global and + * returns the xu transport API. + * + * @param cls our `struct GNUNET_TRANSPORT_PluginEnvironment` + * @return NULL + */ +void * +libgnunet_plugin_transport_xu_done (void *cls) +{ + struct GNUNET_TRANSPORT_PluginFunctions *api = cls; + struct Plugin *plugin = api->cls; + struct PrettyPrinterContext *cur; + + if (NULL == plugin) + { + GNUNET_free (api); + return NULL; + } + if (NULL != plugin->select_task_v4) + { + GNUNET_SCHEDULER_cancel (plugin->select_task_v4); + plugin->select_task_v4 = NULL; + } + if (NULL != plugin->select_task_v6) + { + GNUNET_SCHEDULER_cancel (plugin->select_task_v6); + plugin->select_task_v6 = NULL; + } + if (NULL != plugin->sockv4) + { + GNUNET_break (GNUNET_OK == + GNUNET_NETWORK_socket_close (plugin->sockv4)); + plugin->sockv4 = NULL; + } + if (NULL != plugin->sockv6) + { + GNUNET_break (GNUNET_OK == + GNUNET_NETWORK_socket_close (plugin->sockv6)); + plugin->sockv6 = NULL; + } + if (NULL != plugin->nat) + { + GNUNET_NAT_unregister (plugin->nat); + plugin->nat = NULL; + } + GNUNET_CONTAINER_multipeermap_destroy (plugin->sessions); + + while (NULL != (cur = plugin->ppc_dll_head)) + { + GNUNET_break (0); + GNUNET_CONTAINER_DLL_remove (plugin->ppc_dll_head, + plugin->ppc_dll_tail, + cur); + GNUNET_RESOLVER_request_cancel (cur->resolver_handle); + if (NULL != cur->timeout_task) + { + GNUNET_SCHEDULER_cancel (cur->timeout_task); + cur->timeout_task = NULL; + } + GNUNET_free (cur); + } + GNUNET_free (plugin); + GNUNET_free (api); + return NULL; +} + +/* end of plugin_transport_xu.c */ |