/* This file is part of GNUnet (C) 2010, 2011 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 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., 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 */ #include "platform.h" #include "gnunet_hello_lib.h" #include "gnunet_util_lib.h" #include "gnunet_fragmentation_lib.h" #include "gnunet_nat_lib.h" #include "gnunet_protocols.h" #include "gnunet_resolver_service.h" #include "gnunet_signatures.h" #include "gnunet_statistics_service.h" #include "gnunet_transport_service.h" #include "gnunet_transport_plugin.h" #include "transport.h" #define DEBUG_UDP GNUNET_NO /** * MTU for fragmentation subsystem. Should be conservative since * all communicating peers MUST work with this MTU. */ #define UDP_MTU 1400 /** * Number of messages we can defragment in parallel. We only really * defragment 1 message at a time, but if messages get re-ordered, we * may want to keep knowledge about the previous message to avoid * discarding the current message in favor of a single fragment of a * previous message. 3 should be good since we don't expect massive * message reorderings with UDP. */ #define UDP_MAX_MESSAGES_IN_DEFRAG 3 /** * We keep a defragmentation queue per sender address. How many * sender addresses do we support at the same time? Memory consumption * is roughly a factor of 32k * UDP_MAX_MESSAGES_IN_DEFRAG times this * value. (So 128 corresponds to 12 MB and should suffice for * connecting to roughly 128 peers via UDP). */ #define UDP_MAX_SENDER_ADDRESSES_WITH_DEFRAG 128 /** * UDP Message-Packet header (after defragmentation). */ struct UDPMessage { /** * Message header. */ struct GNUNET_MessageHeader header; /** * Always zero for now. */ uint32_t reserved; /** * What is the identity of the sender */ struct GNUNET_PeerIdentity sender; }; /** * Network format for IPv4 addresses. */ struct IPv4UdpAddress { /** * IPv4 address, in network byte order. */ uint32_t ipv4_addr GNUNET_PACKED; /** * Port number, in network byte order. */ uint16_t u4_port GNUNET_PACKED; }; /** * Network format for IPv6 addresses. */ struct IPv6UdpAddress { /** * IPv6 address. */ struct in6_addr ipv6_addr GNUNET_PACKED; /** * Port number, in network byte order. */ uint16_t u6_port GNUNET_PACKED; }; /* Forward definition */ struct Plugin; /** * Session with another peer. */ struct PeerSession { /** * Which peer is this session for? */ struct GNUNET_PeerIdentity target; /** * Pointer to the global plugin struct. */ struct Plugin *plugin; /** * Address of the other peer */ const struct sockaddr *sock_addr; /** * Function to call upon completion of the transmission. */ GNUNET_TRANSPORT_TransmitContinuation cont; /** * Closure for 'cont'. */ void *cont_cls; /** * Current outgoing message to this peer. */ struct GNUNET_FRAGMENT_Context *frag; }; /** * Data structure to track defragmentation contexts based * on the source of the UDP traffic. */ struct ReceiveContext { /** * Defragmentation context. */ struct GNUNET_DEFRAGMENT_Context *defrag; /** * Source address this receive context is for (allocated at the * end of the struct). */ const struct sockaddr *src_addr; /** * Reference to master plugin struct. */ struct Plugin *plugin; /** * Node in the defrag heap. */ struct GNUNET_CONTAINER_HeapNode *hnode; /** * Length of 'src_addr' */ size_t addr_len; }; /** * Encapsulation of all of the state of the plugin. */ struct Plugin { /** * Our environment. */ struct GNUNET_TRANSPORT_PluginEnvironment *env; /** * Session of peers with whom we are currently connected, * map of peer identity to 'struct PeerSession'. */ struct GNUNET_CONTAINER_MultiHashMap *sessions; /** * Heap with all of our defragmentation activities. */ struct GNUNET_CONTAINER_Heap *defrags; /** * ID of select task */ GNUNET_SCHEDULER_TaskIdentifier select_task; /** * Tokenizer for inbound messages. */ struct GNUNET_SERVER_MessageStreamTokenizer *mst; /** * Bandwidth tracker to limit global UDP traffic. */ struct GNUNET_BANDWIDTH_Tracker tracker; /** * Address we were told to bind to exclusively (IPv4). */ char *bind4_address; /** * Address we were told to bind to exclusively (IPv6). */ char *bind6_address; /** * Handle to NAT traversal support. */ struct GNUNET_NAT_Handle *nat; /** * FD Read set */ struct GNUNET_NETWORK_FDSet *rs; /** * The read socket for IPv4 */ struct GNUNET_NETWORK_Handle *sockv4; /** * The read socket for IPv6 */ struct GNUNET_NETWORK_Handle *sockv6; /** * expected delay for ACKs */ struct GNUNET_TIME_Relative last_expected_delay; /** * Port we listen on. */ uint16_t port; /** * Port we advertise on. */ uint16_t aport; }; /** * Lookup the session for the given peer. * * @param plugin the plugin * @param peer peer's identity * @return NULL if we have no session */ struct PeerSession * find_session (struct Plugin *plugin, const struct GNUNET_PeerIdentity *peer) { return GNUNET_CONTAINER_multihashmap_get (plugin->sessions, &peer->hashPubKey); } /** * 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 udp_disconnect (void *cls, const struct GNUNET_PeerIdentity *target) { struct Plugin *plugin = cls; struct PeerSession *session; session = find_session (plugin, target); if (NULL == session) return; GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap_remove (plugin->sessions, &target->hashPubKey, session)); plugin->last_expected_delay = GNUNET_FRAGMENT_context_destroy (session->frag); session->cont (session->cont_cls, target, GNUNET_SYSERR); GNUNET_free (session); } /** * Actually send out the message. * * @param plugin the plugin * @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 msgbuf_size 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_send (struct Plugin *plugin, const struct sockaddr *sa, const struct GNUNET_MessageHeader *msg) { ssize_t sent; size_t slen; switch (sa->sa_family) { case AF_INET: sent = GNUNET_NETWORK_socket_sendto (plugin->sockv4, msg, ntohs (msg->size), sa, slen = sizeof (struct sockaddr_in)); break; case AF_INET6: sent = GNUNET_NETWORK_socket_sendto (plugin->sockv6, msg, ntohs (msg->size), sa, slen = sizeof (struct sockaddr_in6)); break; default: GNUNET_break (0); return 0; } if (GNUNET_SYSERR == sent) GNUNET_log_strerror (GNUNET_ERROR_TYPE_INFO, "sendto"); #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "UDP transmited %u-byte message to %s (%d: %s)\n", (unsigned int) ntohs (msg->size), GNUNET_a2s (sa, slen), (int) sent, (sent < 0) ? STRERROR (errno) : "ok"); #endif return sent; } /** * Function that is called with messages created by the fragmentation * module. In the case of the 'proc' callback of the * GNUNET_FRAGMENT_context_create function, this function must * eventually call 'GNUNET_FRAGMENT_context_transmission_done'. * * @param cls closure, the 'struct PeerSession' * @param msg the message that was created */ static void send_fragment (void *cls, const struct GNUNET_MessageHeader *msg) { struct PeerSession *session = cls; udp_send (session->plugin, session->sock_addr, msg); GNUNET_FRAGMENT_context_transmission_done (session->frag); } /** * 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 msgbuf_size 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 session identifier used for this session (NULL for UDP) * @param addr the addr to send the message to * @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 (may return 0 and the message can * still be transmitted later!) */ static ssize_t udp_plugin_send (void *cls, const struct GNUNET_PeerIdentity *target, const char *msgbuf, size_t msgbuf_size, unsigned int priority, struct GNUNET_TIME_Relative timeout, struct Session *session, const void *addr, size_t addrlen, int force_address, GNUNET_TRANSPORT_TransmitContinuation cont, void *cont_cls) { struct Plugin *plugin = cls; struct PeerSession *peer_session; const struct IPv4UdpAddress *t4; const struct IPv6UdpAddress *t6; struct sockaddr_in *v4; struct sockaddr_in6 *v6; size_t mlen = msgbuf_size + sizeof (struct UDPMessage); char mbuf[mlen]; struct UDPMessage *udp; if (force_address == GNUNET_SYSERR) return GNUNET_SYSERR; GNUNET_assert (NULL == session); if (mlen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) { GNUNET_break (0); return GNUNET_SYSERR; } switch (addrlen) { case sizeof(struct IPv4UdpAddress): t4 = addr; peer_session = GNUNET_malloc (sizeof (struct PeerSession) + sizeof (struct sockaddr_in)); v4 = (struct sockaddr_in*) &peer_session[1]; v4->sin_family = AF_INET; #if HAVE_SOCKADDR_IN_SIN_LEN v4->sin_len = sizeof (struct sockaddr_in); #endif v4->sin_port = t4->u4_port; v4->sin_addr.s_addr = t4->ipv4_addr; break; case sizeof(struct IPv6UdpAddress): t6 = addr; peer_session = GNUNET_malloc (sizeof (struct PeerSession) + sizeof (struct sockaddr_in6)); v6 = (struct sockaddr_in6*) &peer_session[1]; v6->sin6_family = AF_INET6; #if HAVE_SOCKADDR_IN_SIN_LEN v6->sin6_len = sizeof (struct sockaddr_in6); #endif v6->sin6_port = t6->u6_port; v6->sin6_addr = t6->ipv6_addr; break; default: /* Must have a valid address to send to */ GNUNET_break_op(0); return GNUNET_SYSERR; } udp = (struct UDPMessage*) mbuf; udp->header.size = htons (mlen); udp->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_MESSAGE); udp->reserved = htonl (0); udp->sender = *plugin->env->my_identity; memcpy (&udp[1], msgbuf, msgbuf_size); peer_session->target = *target; peer_session->plugin = plugin; peer_session->sock_addr = (const struct sockaddr*) &peer_session[1]; peer_session->cont = cont; peer_session->cont_cls = cont_cls; if (mlen <= UDP_MTU) { mlen = udp_send (plugin, peer_session->sock_addr, &udp->header); cont (cont_cls, target, (mlen > 0) ? GNUNET_OK : GNUNET_SYSERR); GNUNET_free (peer_session); } else { GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap_put (plugin->sessions, &target->hashPubKey, peer_session, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)); peer_session->frag = GNUNET_FRAGMENT_context_create (plugin->env->stats, UDP_MTU, &plugin->tracker, plugin->last_expected_delay, &udp->header, &send_fragment, peer_session); } return mlen; } /** * Closure for 'process_inbound_tokenized_messages' */ struct SourceInformation { /** * Sender identity. */ struct GNUNET_PeerIdentity sender; /** * Source address. */ const void *arg; /** * Number of bytes in source address. */ size_t args; }; /** * Message tokenizer has broken up an incomming message. Pass it on * to the service. * * @param cls the 'struct Plugin' * @param client the 'struct SourceInformation' * @param hdr the actual message */ static void process_inbound_tokenized_messages (void *cls, void *client, const struct GNUNET_MessageHeader *hdr) { struct Plugin *plugin = cls; struct SourceInformation* si = client; struct GNUNET_TRANSPORT_ATS_Information distance[2]; /* setup ATS */ distance[0].type = htonl (GNUNET_TRANSPORT_ATS_QUALITY_NET_DISTANCE); distance[0].value = htonl (1); distance[1].type = htonl (GNUNET_TRANSPORT_ATS_ARRAY_TERMINATOR); distance[1].value = htonl (0); plugin->env->receive (plugin->env->cls, &si->sender, hdr, distance, 2, NULL, si->arg, si->args); } /** * We've received a UDP Message. Process it (pass contents to main service). * * @param plugin plugin context * @param msg the message * @param sender_addr sender address * @param sender_addr_len number of bytes in sender_addr */ static void process_udp_message (struct Plugin *plugin, const struct UDPMessage *msg, const struct sockaddr *sender_addr, socklen_t sender_addr_len) { struct SourceInformation si; struct IPv4UdpAddress u4; struct IPv6UdpAddress u6; const void *arg; size_t args; if (0 != ntohl (msg->reserved)) { GNUNET_break_op (0); return; } if (ntohs (msg->header.size) < sizeof (struct GNUNET_MessageHeader) + sizeof (struct UDPMessage)) { GNUNET_break_op (0); return; } /* convert address */ switch (sender_addr->sa_family) { case AF_INET: GNUNET_assert (sender_addr_len == sizeof (struct sockaddr_in)); u4.ipv4_addr = ((struct sockaddr_in *) sender_addr)->sin_addr.s_addr; u4.u4_port = ((struct sockaddr_in *) sender_addr)->sin_port; arg = &u4; args = sizeof (u4); break; case AF_INET6: GNUNET_assert (sender_addr_len == sizeof (struct sockaddr_in6)); u6.ipv6_addr = ((struct sockaddr_in6*) sender_addr)->sin6_addr; u6.u6_port = ((struct sockaddr_in6 *) sender_addr)->sin6_port; arg = &u6; args = sizeof (u6); break; default: GNUNET_break (0); return; } #if DEBUG_UDP GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp", "Received message with %u bytes from peer `%s' at `%s'\n", (unsigned int) ntohs (msg->header.size), GNUNET_i2s (&msg->sender), GNUNET_a2s (sender_addr, sender_addr_len)); #endif /* iterate over all embedded messages */ si.sender = msg->sender; si.arg = arg; si.args = args; GNUNET_SERVER_mst_receive (plugin->mst, &si, (const char*) &msg[1], ntohs (msg->header.size) - sizeof (struct UDPMessage), GNUNET_YES, GNUNET_NO); } /** * Process a defragmented message. * * @param cls the 'struct ReceiveContext' * @param msg the message */ static void fragment_msg_proc (void *cls, const struct GNUNET_MessageHeader *msg) { struct ReceiveContext *rc = cls; if (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_MESSAGE) { GNUNET_break (0); return; } if (ntohs (msg->size) < sizeof(struct UDPMessage)) { GNUNET_break (0); return; } process_udp_message (rc->plugin, (const struct UDPMessage*) msg, rc->src_addr, rc->addr_len); } /** * Transmit an acknowledgement. * * @param cls the 'struct ReceiveContext' * @param id message ID (unused) * @param msg ack to transmit */ static void ack_proc (void *cls, uint32_t id, const struct GNUNET_MessageHeader *msg) { struct ReceiveContext *rc = cls; size_t msize = sizeof (struct UDPMessage) + ntohs (msg->size); char buf[msize]; struct UDPMessage *udp; #if DEBUG_UDP GNUNET_log_from (GNUNET_ERROR_TYPE_DEBUG, "udp", "Sending ACK to `%s'\n", GNUNET_a2s (rc->src_addr, (rc->src_addr->sa_family == AF_INET) ? sizeof (struct sockaddr_in) : sizeof (struct sockaddr_in6))); #endif udp = (struct UDPMessage*) buf; udp->header.size = htons ((uint16_t) msize); udp->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_ACK); udp->reserved = htonl (0); udp->sender = *rc->plugin->env->my_identity; memcpy (&udp[1], msg, ntohs (msg->size)); (void) udp_send (rc->plugin, rc->src_addr, &udp->header); } /** * Closure for 'find_receive_context'. */ struct FindReceiveContext { /** * Where to store the result. */ struct ReceiveContext *rc; /** * Address to find. */ const struct sockaddr *addr; /** * Number of bytes in 'addr'. */ socklen_t addr_len; }; /** * Scan the heap for a receive context with the given address. * * @param cls the 'struct FindReceiveContext' * @param node internal node of the heap * @param element value stored at the node (a 'struct ReceiveContext') * @param cost cost associated with the node * @return GNUNET_YES if we should continue to iterate, * GNUNET_NO if not. */ static int find_receive_context (void *cls, struct GNUNET_CONTAINER_HeapNode *node, void *element, GNUNET_CONTAINER_HeapCostType cost) { struct FindReceiveContext *frc = cls; struct ReceiveContext *e = element; if ( (frc->addr_len == e->addr_len) && (0 == memcmp (frc->addr, e->src_addr, frc->addr_len) ) ) { frc->rc = e; return GNUNET_NO; } return GNUNET_YES; } /** * Read and process a message from the given socket. * * @param plugin the overall plugin * @param rsock socket to read from */ static void udp_read (struct Plugin *plugin, struct GNUNET_NETWORK_Handle *rsock) { socklen_t fromlen; char addr[32]; char buf[65536]; ssize_t ret; const struct GNUNET_MessageHeader *msg; const struct GNUNET_MessageHeader *ack; struct PeerSession *peer_session; const struct UDPMessage *udp; struct ReceiveContext *rc; struct GNUNET_TIME_Absolute now; struct FindReceiveContext frc; fromlen = sizeof (addr); memset (&addr, 0, sizeof(addr)); ret = GNUNET_NETWORK_socket_recvfrom (rsock, buf, sizeof (buf), (struct sockaddr *)&addr, &fromlen); if (ret < sizeof (struct GNUNET_MessageHeader)) { GNUNET_break_op (0); return; } #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "UDP received %u-byte message from `%s'\n", (unsigned int) ret, GNUNET_a2s ((const struct sockaddr*) addr, fromlen)); #endif msg = (const struct GNUNET_MessageHeader *) buf; if (ret != ntohs (msg->size)) { GNUNET_break_op (0); return; } switch (ntohs (msg->type)) { case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_MESSAGE: if (ntohs (msg->size) < sizeof (struct UDPMessage)) { GNUNET_break_op (0); return; } process_udp_message (plugin, (const struct UDPMessage *) msg, (const struct sockaddr*) addr, fromlen); return; case GNUNET_MESSAGE_TYPE_TRANSPORT_UDP_ACK: if (ntohs (msg->size) < sizeof (struct UDPMessage) + sizeof (struct GNUNET_MessageHeader)) { GNUNET_break_op (0); return; } udp = (const struct UDPMessage *) msg; if (ntohl (udp->reserved) != 0) { GNUNET_break_op (0); return; } ack = (const struct GNUNET_MessageHeader*) &udp[1]; if (ntohs (ack->size) != ntohs (msg->size) - sizeof (struct UDPMessage)) { GNUNET_break_op (0); return; } #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "UDP processes %u-byte acknowledgement from `%s' at `%s'\n", (unsigned int) ntohs (msg->size), GNUNET_i2s (&udp->sender), GNUNET_a2s ((const struct sockaddr*) addr, fromlen)); #endif peer_session = find_session (plugin, &udp->sender); if (NULL == peer_session) { #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Session for ACK not found, dropping ACK!\n"); #endif return; } if (GNUNET_OK != GNUNET_FRAGMENT_process_ack (peer_session->frag, ack)) return; GNUNET_assert (GNUNET_OK == GNUNET_CONTAINER_multihashmap_remove (plugin->sessions, &udp->sender.hashPubKey, peer_session)); plugin->last_expected_delay = GNUNET_FRAGMENT_context_destroy (peer_session->frag); peer_session->cont (peer_session->cont_cls, &udp->sender, GNUNET_OK); GNUNET_free (peer_session); return; case GNUNET_MESSAGE_TYPE_FRAGMENT: frc.rc = NULL; frc.addr = (const struct sockaddr*) addr; frc.addr_len = fromlen; GNUNET_CONTAINER_heap_iterate (plugin->defrags, &find_receive_context, &frc); now = GNUNET_TIME_absolute_get (); rc = frc.rc; if (rc == NULL) { /* need to create a new RC */ rc = GNUNET_malloc (sizeof (struct ReceiveContext) + fromlen); memcpy (&rc[1], addr, fromlen); rc->src_addr = (const struct sockaddr*) &rc[1]; rc->addr_len = fromlen; rc->plugin = plugin; rc->defrag = GNUNET_DEFRAGMENT_context_create (plugin->env->stats, UDP_MTU, UDP_MAX_MESSAGES_IN_DEFRAG, rc, &fragment_msg_proc, &ack_proc); rc->hnode = GNUNET_CONTAINER_heap_insert (plugin->defrags, rc, (GNUNET_CONTAINER_HeapCostType) now.abs_value); } #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "UDP processes %u-byte fragment from `%s'\n", (unsigned int) ntohs (msg->size), GNUNET_a2s ((const struct sockaddr*) addr, fromlen)); #endif if (GNUNET_OK == GNUNET_DEFRAGMENT_process_fragment (rc->defrag, msg)) { /* keep this 'rc' from expiring */ GNUNET_CONTAINER_heap_update_cost (plugin->defrags, rc->hnode, (GNUNET_CONTAINER_HeapCostType) now.abs_value); } if (GNUNET_CONTAINER_heap_get_size (plugin->defrags) > UDP_MAX_SENDER_ADDRESSES_WITH_DEFRAG) { /* remove 'rc' that was inactive the longest */ rc = GNUNET_CONTAINER_heap_remove_root (plugin->defrags); GNUNET_assert (NULL != rc); GNUNET_DEFRAGMENT_context_destroy (rc->defrag); GNUNET_free (rc); } return; default: GNUNET_break_op (0); return; } } /** * 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. * * @param cls the plugin handle * @param tc the scheduling context (for rescheduling this function again) */ static void udp_plugin_select (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct Plugin *plugin = cls; plugin->select_task = GNUNET_SCHEDULER_NO_TASK; if ( (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; if ( (NULL != plugin->sockv4) && (GNUNET_NETWORK_fdset_isset (tc->read_ready, plugin->sockv4)) ) udp_read (plugin, plugin->sockv4); if ( (NULL != plugin->sockv6) && (GNUNET_NETWORK_fdset_isset (tc->read_ready, plugin->sockv6)) ) udp_read (plugin, plugin->sockv6); plugin->select_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_SCHEDULER_NO_TASK, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, NULL, &udp_plugin_select, plugin); } /** * 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 open_port or adv_port */ static int check_port (struct Plugin *plugin, uint16_t in_port) { if ( (in_port == plugin->port) || (in_port == plugin->aport) ) 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 the address * @param addrlen length of addr * @return GNUNET_OK if this is a plausible address for this peer * and transport, GNUNET_SYSERR if not * */ static int udp_plugin_check_address (void *cls, const void *addr, size_t addrlen) { struct Plugin *plugin = cls; struct IPv4UdpAddress *v4; struct IPv6UdpAddress *v6; if ((addrlen != sizeof (struct IPv4UdpAddress)) && (addrlen != sizeof (struct IPv6UdpAddress))) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (addrlen == sizeof (struct IPv4UdpAddress)) { v4 = (struct IPv4UdpAddress *) addr; if (GNUNET_OK != check_port (plugin, ntohs (v4->u4_port))) return GNUNET_SYSERR; if (GNUNET_OK != GNUNET_NAT_test_address (plugin->nat, &v4->ipv4_addr, sizeof (struct in_addr))) return GNUNET_SYSERR; } else { v6 = (struct IPv6UdpAddress *) addr; if (IN6_IS_ADDR_LINKLOCAL (&v6->ipv6_addr)) { GNUNET_break_op (0); return GNUNET_SYSERR; } if (GNUNET_OK != check_port (plugin, ntohs (v6->u6_port))) return GNUNET_SYSERR; if (GNUNET_OK != GNUNET_NAT_test_address (plugin->nat, &v6->ipv6_addr, sizeof (struct in6_addr))) return GNUNET_SYSERR; } return GNUNET_OK; } /** * 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 * @param addrlen length of the address * @return string representing the same address */ static const char* udp_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 IPv4UdpAddress *t4; const struct IPv6UdpAddress *t6; int af; uint16_t port; if (addrlen == sizeof (struct IPv6UdpAddress)) { t6 = addr; af = AF_INET6; port = ntohs (t6->u6_port); memcpy (&a6, &t6->ipv6_addr, sizeof (a6)); sb = &a6; } else if (addrlen == sizeof (struct IPv4UdpAddress)) { t4 = addr; af = AF_INET; port = ntohs (t4->u4_port); memcpy (&a4, &t4->ipv4_addr, sizeof (a4)); sb = &a4; } else { GNUNET_break_op (0); return NULL; } inet_ntop (af, sb, buf, INET6_ADDRSTRLEN); GNUNET_snprintf (rbuf, sizeof (rbuf), "%s:%u", buf, port); return rbuf; } /** * Closure for 'append_port'. */ struct PrettyPrinterContext { /** * Function to call with the result. */ GNUNET_TRANSPORT_AddressStringCallback asc; /** * Clsoure for 'asc'. */ void *asc_cls; /** * Port to add after the IP address. */ uint16_t port; }; /** * 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; 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_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 PrettyPrinterContext *ppc; const void *sb; size_t sbs; struct sockaddr_in a4; struct sockaddr_in6 a6; const struct IPv4UdpAddress *u4; const struct IPv6UdpAddress *u6; uint16_t port; if (addrlen == sizeof (struct IPv6UdpAddress)) { 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; memcpy (&a6.sin6_addr, &u6->ipv6_addr, sizeof (struct in6_addr)); port = ntohs (u6->u6_port); sb = &a6; sbs = sizeof (a6); } else if (addrlen == sizeof (struct IPv4UdpAddress)) { 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); sb = &a4; sbs = sizeof (a4); } else { /* 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; ppc->port = port; GNUNET_RESOLVER_hostname_get (sb, sbs, !numeric, timeout, &append_port, ppc); } /** * Our external IP address/port mapping has changed. * * @param cls closure, the 'struct LocalAddrList' * @param add_remove GNUNET_YES to mean the new public IP address, GNUNET_NO to mean * the previous (now invalid) one * @param addr either the previous or the new public IP address * @param addrlen actual lenght of the address */ static void udp_nat_port_map_callback (void *cls, int add_remove, const struct sockaddr *addr, socklen_t addrlen) { struct Plugin *plugin = cls; struct IPv4UdpAddress u4; struct IPv6UdpAddress u6; void *arg; size_t args; /* convert 'addr' to our internal format */ switch (addr->sa_family) { case AF_INET: GNUNET_assert (addrlen == sizeof (struct sockaddr_in)); u4.ipv4_addr = ((struct sockaddr_in *) addr)->sin_addr.s_addr; u4.u4_port = ((struct sockaddr_in *) addr)->sin_port; arg = &u4; args = sizeof (u4); break; case AF_INET6: GNUNET_assert (addrlen == sizeof (struct sockaddr_in6)); memcpy (&u6.ipv6_addr, &((struct sockaddr_in6 *) addr)->sin6_addr, sizeof (struct in6_addr)); u6.u6_port = ((struct sockaddr_in6 *) addr)->sin6_port; arg = &u6; args = sizeof (u6); break; default: GNUNET_break (0); return; } /* modify our published address list */ plugin->env->notify_address (plugin->env->cls, add_remove, arg, args); } /** * The exported method. Makes the core api available via a global and * returns the udp transport API. * * @param cls our 'struct GNUNET_TRANSPORT_PluginEnvironment' * @return our 'struct GNUNET_TRANSPORT_PluginFunctions' */ void * libgnunet_plugin_transport_udp_init (void *cls) { struct GNUNET_TRANSPORT_PluginEnvironment *env = cls; unsigned long long port; unsigned long long aport; struct GNUNET_TRANSPORT_PluginFunctions *api; struct Plugin *plugin; int sockets_created; struct sockaddr_in serverAddrv4; struct sockaddr_in6 serverAddrv6; struct sockaddr *serverAddr; struct sockaddr *addrs[2]; socklen_t addrlens[2]; socklen_t addrlen; unsigned int tries; unsigned long long udp_max_bps; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-udp", "PORT", &port)) port = 2086; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-udp", "MAX_BPS", &udp_max_bps)) udp_max_bps = 1024 * 1024 * 50; /* 50 MB/s == infinity for practical purposes */ if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_number (env->cfg, "transport-udp", "ADVERTISED_PORT", &aport)) aport = port; if (port > 65535) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Given `%s' option is out of range: %llu > %u\n"), "PORT", port, 65535); return NULL; } memset (&serverAddrv6, 0, sizeof (serverAddrv6)); memset (&serverAddrv4, 0, sizeof (serverAddrv4)); plugin = GNUNET_malloc (sizeof (struct Plugin)); GNUNET_BANDWIDTH_tracker_init (&plugin->tracker, GNUNET_BANDWIDTH_value_init ((uint32_t) udp_max_bps), 30); plugin->last_expected_delay = GNUNET_TIME_UNIT_SECONDS; plugin->port = port; plugin->aport = aport; plugin->env = env; api = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_PluginFunctions)); api->cls = plugin; api->send = &udp_plugin_send; api->disconnect = &udp_disconnect; api->address_pretty_printer = &udp_plugin_address_pretty_printer; api->address_to_string = &udp_address_to_string; api->check_address = &udp_plugin_check_address; if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_string(env->cfg, "transport-udp", "BINDTO", &plugin->bind4_address)) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Binding udp plugin to specific address: `%s'\n", plugin->bind4_address); if (1 != inet_pton(AF_INET, plugin->bind4_address, &serverAddrv4.sin_addr)) { GNUNET_free (plugin->bind4_address); GNUNET_free (plugin); GNUNET_free (api); return NULL; } } if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_string(env->cfg, "transport-udp", "BINDTO6", &plugin->bind6_address)) { GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "Binding udp plugin to specific address: `%s'\n", plugin->bind6_address); if (1 != inet_pton(AF_INET6, plugin->bind6_address, &serverAddrv6.sin6_addr)) { GNUNET_log(GNUNET_ERROR_TYPE_ERROR, _("Invalid IPv6 address: `%s'\n"), plugin->bind6_address); GNUNET_free_non_null (plugin->bind4_address); GNUNET_free (plugin->bind6_address); GNUNET_free (plugin); GNUNET_free (api); return NULL; } } plugin->defrags = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN); plugin->sessions = GNUNET_CONTAINER_multihashmap_create (UDP_MAX_SENDER_ADDRESSES_WITH_DEFRAG * 2); sockets_created = 0; if ( (GNUNET_YES != GNUNET_CONFIGURATION_get_value_yesno (plugin->env->cfg, "nat", "DISABLEV6"))) { plugin->sockv6 = GNUNET_NETWORK_socket_create (PF_INET6, SOCK_DGRAM, 0); if (NULL == plugin->sockv6) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket"); } else { #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 (plugin->port); addrlen = sizeof (serverAddrv6); serverAddr = (struct sockaddr *) &serverAddrv6; #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Binding to IPv6 port %d\n", ntohs(serverAddrv6.sin6_port)); #endif tries = 0; while (GNUNET_NETWORK_socket_bind (plugin->sockv6, serverAddr, addrlen) != GNUNET_OK) { serverAddrv6.sin6_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000); /* Find a good, non-root port */ #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "IPv6 Binding failed, trying new port %d\n", ntohs(serverAddrv6.sin6_port)); #endif tries++; if (tries > 10) { GNUNET_NETWORK_socket_close (plugin->sockv6); plugin->sockv6 = NULL; break; } } if (plugin->sockv6 != NULL) { addrs[sockets_created] = (struct sockaddr*) &serverAddrv6; addrlens[sockets_created] = sizeof (serverAddrv6); sockets_created++; } } } plugin->mst = GNUNET_SERVER_mst_create (&process_inbound_tokenized_messages, plugin); plugin->sockv4 = GNUNET_NETWORK_socket_create (PF_INET, SOCK_DGRAM, 0); if (NULL == plugin->sockv4) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "socket"); } else { #if HAVE_SOCKADDR_IN_SIN_LEN serverAddrv4.sin_len = sizeof (serverAddrv4); #endif serverAddrv4.sin_family = AF_INET; serverAddrv4.sin_addr.s_addr = INADDR_ANY; serverAddrv4.sin_port = htons (plugin->port); addrlen = sizeof (serverAddrv4); serverAddr = (struct sockaddr *) &serverAddrv4; #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Binding to IPv4 port %d\n", ntohs(serverAddrv4.sin_port)); #endif tries = 0; while (GNUNET_NETWORK_socket_bind (plugin->sockv4, serverAddr, addrlen) != GNUNET_OK) { serverAddrv4.sin_port = htons (GNUNET_CRYPTO_random_u32(GNUNET_CRYPTO_QUALITY_STRONG, 33537) + 32000); /* Find a good, non-root port */ #if DEBUG_UDP GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "IPv4 Binding failed, trying new port %d\n", ntohs(serverAddrv4.sin_port)); #endif tries++; if (tries > 10) { GNUNET_NETWORK_socket_close (plugin->sockv4); plugin->sockv4 = NULL; break; } } if (plugin->sockv4 != NULL) { addrs[sockets_created] = (struct sockaddr*) &serverAddrv4; addrlens[sockets_created] = sizeof (serverAddrv4); sockets_created++; } } plugin->rs = GNUNET_NETWORK_fdset_create (); GNUNET_NETWORK_fdset_zero (plugin->rs); if (NULL != plugin->sockv4) GNUNET_NETWORK_fdset_set (plugin->rs, plugin->sockv4); if (NULL != plugin->sockv6) GNUNET_NETWORK_fdset_set (plugin->rs, plugin->sockv6); plugin->select_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT, GNUNET_SCHEDULER_NO_TASK, GNUNET_TIME_UNIT_FOREVER_REL, plugin->rs, NULL, &udp_plugin_select, plugin); if (sockets_created == 0) GNUNET_log (GNUNET_ERROR_TYPE_WARNING, _("Failed to open UDP sockets\n")); plugin->nat = GNUNET_NAT_register (env->cfg, GNUNET_NO, port, sockets_created, (const struct sockaddr**) addrs, addrlens, &udp_nat_port_map_callback, NULL, plugin); return api; } /** * Destroy a session, plugin is being unloaded. * * @param cls unused * @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 destroy_session (void *cls, const GNUNET_HashCode *key, void *value) { struct PeerSession *peer_session = value; GNUNET_FRAGMENT_context_destroy (peer_session->frag); GNUNET_free (peer_session); return GNUNET_OK; } /** * Shutdown the plugin. * * @param cls our 'struct GNUNET_TRANSPORT_PluginFunctions' * @return NULL */ void * libgnunet_plugin_transport_udp_done (void *cls) { struct GNUNET_TRANSPORT_PluginFunctions *api = cls; struct Plugin *plugin = api->cls; struct ReceiveContext *rc; /* FIXME: clean up heap and hashmap */ GNUNET_CONTAINER_multihashmap_iterate (plugin->sessions, &destroy_session, NULL); GNUNET_CONTAINER_multihashmap_destroy (plugin->sessions); plugin->sessions = NULL; while (NULL != (rc = GNUNET_CONTAINER_heap_remove_root (plugin->defrags))) { GNUNET_DEFRAGMENT_context_destroy (rc->defrag); GNUNET_free (rc); } GNUNET_CONTAINER_heap_destroy (plugin->defrags); if (plugin->select_task != GNUNET_SCHEDULER_NO_TASK) { GNUNET_SCHEDULER_cancel (plugin->select_task); plugin->select_task = GNUNET_SCHEDULER_NO_TASK; } if (plugin->sockv4 != NULL) { GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (plugin->sockv4)); plugin->sockv4 = NULL; } if (plugin->sockv6 != NULL) { GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (plugin->sockv6)); plugin->sockv6 = NULL; } GNUNET_SERVER_mst_destroy (plugin->mst); GNUNET_NETWORK_fdset_destroy (plugin->rs); GNUNET_NAT_unregister (plugin->nat); plugin->nat = NULL; GNUNET_free (plugin); GNUNET_free (api); return NULL; } /* end of plugin_transport_udp.c */