/* This file is part of GNUnet. (C) 2010 Christian Grothoff 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 vpn/gnunet-daemon-vpn.c * @brief * @author Philipp Toelke */ #include "platform.h" #include "gnunet_getopt_lib.h" #include "gnunet_program_lib.h" #include "gnunet-vpn-packet.h" #include "gnunet_common.h" #include "gnunet_protocols.h" #include "gnunet_applications.h" #include #include "gnunet_client_lib.h" #include "gnunet_container_lib.h" #include "gnunet_constants.h" #include #include "gnunet-daemon-vpn-helper.h" #include "gnunet-daemon-vpn-dns.h" #include "gnunet-daemon-vpn.h" #include "gnunet-vpn-checksum.h" const struct GNUNET_CONFIGURATION_Handle *cfg; struct GNUNET_MESH_Handle *mesh_handle; struct GNUNET_CONTAINER_MultiHashMap *hashmap; static struct GNUNET_CONTAINER_Heap *heap; struct tunnel_notify_queue { struct tunnel_notify_queue *next; struct tunnel_notify_queue *prev; size_t len; void *cls; }; /** * If there are at least this many address-mappings, old ones will be removed */ static long long unsigned int max_mappings = 200; /** * Final status code. */ static int ret; /** * This hashmap contains the mapping from peer, service-descriptor, * source-port and destination-port to a socket */ static struct GNUNET_CONTAINER_MultiHashMap *udp_connections; GNUNET_SCHEDULER_TaskIdentifier conn_task; GNUNET_SCHEDULER_TaskIdentifier shs_task; /** * Function scheduled as very last function, cleans up after us *{{{ */ static void cleanup (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tskctx) { GNUNET_assert (0 != (tskctx->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)); /* stop the helper */ cleanup_helper (helper_handle); /* close the connection to the service-dns */ if (dns_connection != NULL) { GNUNET_CLIENT_disconnect (dns_connection, GNUNET_NO); dns_connection = NULL; } if (mesh_handle != NULL) { GNUNET_MESH_disconnect (mesh_handle); mesh_handle = NULL; } if (GNUNET_SCHEDULER_NO_TASK != shs_task) { GNUNET_SCHEDULER_cancel (shs_task); shs_task = GNUNET_SCHEDULER_NO_TASK; } if (GNUNET_SCHEDULER_NO_TASK != conn_task) { GNUNET_SCHEDULER_cancel (conn_task); conn_task = GNUNET_SCHEDULER_NO_TASK; } } /*}}}*/ /** * @return the hash of the IP-Address if a mapping exists, NULL otherwise */ GNUNET_HashCode * address6_mapping_exists (unsigned char addr[]) { GNUNET_HashCode *key = GNUNET_malloc (sizeof (GNUNET_HashCode)); unsigned char *k = (unsigned char *) key; memset (key, 0, sizeof (GNUNET_HashCode)); unsigned int i; for (i = 0; i < 16; i++) k[15 - i] = addr[i]; if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (hashmap, key)) return key; else { GNUNET_free (key); return NULL; } } /** * @return the hash of the IP-Address if a mapping exists, NULL otherwise */ GNUNET_HashCode * address4_mapping_exists (uint32_t addr) { GNUNET_HashCode *key = GNUNET_malloc (sizeof (GNUNET_HashCode)); memset (key, 0, sizeof (GNUNET_HashCode)); unsigned char *c = (unsigned char *) &addr; unsigned char *k = (unsigned char *) key; unsigned int i; for (i = 0; i < 4; i++) k[3 - i] = c[i]; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "a4_m_e: getting with key %08x, addr is %08x, %d.%d.%d.%d\n", *((uint32_t *) (key)), addr, c[0], c[1], c[2], c[3]); if (GNUNET_YES == GNUNET_CONTAINER_multihashmap_contains (hashmap, key)) return key; else { GNUNET_free (key); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Mapping not found!\n"); return NULL; } } static void collect_mappings (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; struct map_entry *me = GNUNET_CONTAINER_heap_remove_root (heap); /* This is free()ed memory! */ me->heap_node = NULL; /* FIXME! GNUNET_MESH_close_tunnel(me->tunnel); */ GNUNET_assert (GNUNET_YES == GNUNET_CONTAINER_multihashmap_remove (hashmap, &me->hash, me)); GNUNET_free (me); } void send_icmp4_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; struct ip_icmp *request = cls; struct ip_icmp *response = alloca (ntohs (request->shdr.size)); GNUNET_assert (response != NULL); memset (response, 0, ntohs (request->shdr.size)); response->shdr.size = request->shdr.size; response->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); response->tun.flags = 0; response->tun.type = htons (0x0800); response->ip_hdr.hdr_lngth = 5; response->ip_hdr.version = 4; response->ip_hdr.proto = 0x01; response->ip_hdr.dadr = request->ip_hdr.sadr; response->ip_hdr.sadr = request->ip_hdr.dadr; response->ip_hdr.tot_lngth = request->ip_hdr.tot_lngth; response->ip_hdr.chks = calculate_ip_checksum ((uint16_t *) & response->ip_hdr, 20); response->icmp_hdr.code = 0; response->icmp_hdr.type = 0x0; /* Magic, more Magic! */ response->icmp_hdr.chks = request->icmp_hdr.chks + 0x8; /* Copy the rest of the packet */ memcpy (response + 1, request + 1, ntohs (request->shdr.size) - sizeof (struct ip_icmp)); write_to_helper (response, ntohs (response->shdr.size)); GNUNET_free (request); } void send_icmp6_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; struct ip6_icmp *request = cls; struct ip6_icmp *response = alloca (ntohs (request->shdr.size)); GNUNET_assert (response != NULL); memset (response, 0, ntohs (request->shdr.size)); response->shdr.size = request->shdr.size; response->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); response->tun.flags = 0; response->tun.type = htons (0x86dd); response->ip6_hdr.hoplmt = 255; response->ip6_hdr.paylgth = request->ip6_hdr.paylgth; response->ip6_hdr.nxthdr = 0x3a; response->ip6_hdr.version = 6; memcpy (&response->ip6_hdr.sadr, &request->ip6_hdr.dadr, 16); memcpy (&response->ip6_hdr.dadr, &request->ip6_hdr.sadr, 16); response->icmp_hdr.code = 0; response->icmp_hdr.type = 0x81; /* Magic, more Magic! */ response->icmp_hdr.chks = request->icmp_hdr.chks - 0x1; /* Copy the rest of the packet */ memcpy (response + 1, request + 1, ntohs (request->shdr.size) - sizeof (struct ip6_icmp)); write_to_helper (response, ntohs (response->shdr.size)); GNUNET_free (request); } /** * cls is the pointer to a GNUNET_MessageHeader that is * followed by the service-descriptor and the packet that should be sent; */ static size_t send_pkt_to_peer_notify_callback (void *cls, size_t size, void *buf) { struct GNUNET_MESH_Tunnel **tunnel = cls; struct tunnel_state *ts = GNUNET_MESH_tunnel_get_data (*tunnel); ts->th = NULL; if (NULL != buf) { struct GNUNET_MessageHeader *hdr = (struct GNUNET_MessageHeader *) (tunnel + 1); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "send_pkt_to_peer_notify_callback: buf = %x; size = %u;\n", buf, size); GNUNET_assert (size >= ntohs (hdr->size)); memcpy (buf, hdr, ntohs (hdr->size)); size = ntohs (hdr->size); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent!\n"); } else size = 0; if (NULL != ts->head) { struct tunnel_notify_queue *element = ts->head; GNUNET_CONTAINER_DLL_remove (ts->head, ts->tail, element); ts->th = GNUNET_MESH_notify_transmit_ready (*tunnel, GNUNET_NO, 42, GNUNET_TIME_relative_divide (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2), (const struct GNUNET_PeerIdentity *) NULL, element->len, send_pkt_to_peer_notify_callback, element->cls); /* save the handle */ GNUNET_free (element); } GNUNET_free (cls); return size; } unsigned int port_in_ports (uint64_t ports, uint16_t port) { uint16_t *ps = (uint16_t *) & ports; return ports == 0 || ps[0] == port || ps[1] == port || ps[2] == port || ps[3] == port; } void send_pkt_to_peer (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { /* peer == NULL means that all peers in this request are connected */ if (peer == NULL) return; struct GNUNET_MESH_Tunnel **tunnel = cls; struct GNUNET_MessageHeader *hdr = (struct GNUNET_MessageHeader *) (tunnel + 1); GNUNET_assert (NULL != tunnel); GNUNET_assert (NULL != *tunnel); struct tunnel_state *ts = GNUNET_MESH_tunnel_get_data (*tunnel); if (NULL == ts->th) { ts->th = GNUNET_MESH_notify_transmit_ready (*tunnel, GNUNET_NO, 42, GNUNET_TIME_relative_divide (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2), (const struct GNUNET_PeerIdentity *) NULL, ntohs (hdr->size), send_pkt_to_peer_notify_callback, cls); } else { struct tunnel_notify_queue *element = GNUNET_malloc (sizeof *element); element->cls = cls; element->len = ntohs (hdr->size); GNUNET_CONTAINER_DLL_insert_tail (ts->head, ts->tail, element); } } /** * Create a new Address from an answer-packet */ void new_ip6addr (unsigned char *buf, const GNUNET_HashCode * peer, const GNUNET_HashCode * service_desc) { /* {{{ */ char *ipv6addr; unsigned long long ipv6prefix; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr)); GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "IPV6PREFIX", &ipv6prefix)); GNUNET_assert (ipv6prefix < 127); ipv6prefix = (ipv6prefix + 7) / 8; inet_pton (AF_INET6, ipv6addr, buf); GNUNET_free (ipv6addr); int peer_length = 16 - ipv6prefix - 6; if (peer_length <= 0) peer_length = 0; int service_length = 16 - ipv6prefix - peer_length; if (service_length <= 0) service_length = 0; memcpy (buf + ipv6prefix, service_desc, service_length); memcpy (buf + ipv6prefix + service_length, peer, peer_length); } /*}}}*/ /** * Create a new Address from an answer-packet */ void new_ip6addr_remote (unsigned char *buf, unsigned char *addr, char addrlen) { /* {{{ */ char *ipv6addr; unsigned long long ipv6prefix; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr)); GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "IPV6PREFIX", &ipv6prefix)); GNUNET_assert (ipv6prefix < 127); ipv6prefix = (ipv6prefix + 7) / 8; inet_pton (AF_INET6, ipv6addr, buf); GNUNET_free (ipv6addr); int local_length = 16 - ipv6prefix; memcpy (buf + ipv6prefix, addr, GNUNET_MIN (addrlen, local_length)); } /*}}}*/ /** * Create a new Address from an answer-packet */ void new_ip4addr_remote (unsigned char *buf, unsigned char *addr, char addrlen) { /* {{{ */ char *ipv4addr; char *ipv4mask; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4ADDR", &ipv4addr)); GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4MASK", &ipv4mask)); uint32_t mask; inet_pton (AF_INET, ipv4addr, buf); int r = inet_pton (AF_INET, ipv4mask, &mask); mask = htonl (mask); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "inet_pton: %d; %m; mask: %08x\n", r, mask); GNUNET_free (ipv4addr); int c; if (mask) { mask = (mask ^ (mask - 1)) >> 1; for (c = 0; mask; c++) { mask >>= 1; } } else { c = CHAR_BIT * sizeof (mask); } c = 32 - c; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "The mask %s has %d leading 1s.\n", ipv4mask, c); GNUNET_free (ipv4mask); if (c % 8 == 0) c = c / 8; else GNUNET_assert (0); memcpy (buf + c, addr, GNUNET_MIN (addrlen, 4 - c)); } /*}}}*/ /** * This gets scheduled with cls pointing to an answer_packet and does everything * needed in order to send it to the helper. * * At the moment this means "inventing" and IPv6-Address for .gnunet-services and * doing nothing for "real" services. */ void process_answer (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { if ((tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) != 0) return; struct answer_packet *pkt = cls; struct answer_packet_list *list; /* This answer is about a .gnunet-service * * It contains an almost complete DNS-Response, we have to fill in the ip * at the offset pkt->addroffset */ if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_SERVICE) { pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP; GNUNET_HashCode key; memset (&key, 0, sizeof (GNUNET_HashCode)); unsigned char *c = ((unsigned char *) pkt) + ntohs (pkt->addroffset); unsigned char *k = (unsigned char *) &key; new_ip6addr (c, &pkt->service_descr.peer, &pkt->service_descr.service_descriptor); /* * Copy the newly generated ip-address to the key backwarts (as only the first part is hashed) */ unsigned int i; for (i = 0; i < 16; i++) k[15 - i] = c[i]; uint16_t namelen = strlen ((char *) pkt->data + 12) + 1; struct map_entry *value = GNUNET_malloc (sizeof (struct map_entry) + namelen); char *name = (char *) (value + 1); value->namelen = namelen; memcpy (name, pkt->data + 12, namelen); memcpy (&value->desc, &pkt->service_descr, sizeof (struct GNUNET_vpn_service_descriptor)); memset (value->additional_ports, 0, 8192); memcpy (&value->hash, &key, sizeof (GNUNET_HashCode)); if (GNUNET_NO == GNUNET_CONTAINER_multihashmap_contains (hashmap, &key)) { GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value, GNUNET_TIME_absolute_get ().abs_value); if (GNUNET_CONTAINER_heap_get_size (heap) > max_mappings) GNUNET_SCHEDULER_add_now (collect_mappings, NULL); } else GNUNET_free (value); list = GNUNET_malloc (htons (pkt->hdr.size) + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); memcpy (&list->pkt, pkt, htons (pkt->hdr.size)); } else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REV) { GNUNET_HashCode key; memset (&key, 0, sizeof key); unsigned char *k = (unsigned char *) &key; unsigned char *s = pkt->data + 12; int i = 0; /* Whoever designed the reverse IPv6-lookup is batshit insane */ for (i = 0; i < 16; i++) { unsigned char c1 = s[(4 * i) + 1]; unsigned char c2 = s[(4 * i) + 3]; if (c1 <= '9') k[i] = c1 - '0'; else k[i] = c1 - 87; /* 87 is the difference between 'a' and 10 */ if (c2 <= '9') k[i] += 16 * (c2 - '0'); else k[i] += 16 * (c2 - 87); } struct map_entry *map_entry = GNUNET_CONTAINER_multihashmap_get (hashmap, &key); uint16_t offset = ntohs (pkt->addroffset); if (map_entry == NULL) { GNUNET_free (pkt); return; } GNUNET_CONTAINER_heap_update_cost (heap, map_entry->heap_node, GNUNET_TIME_absolute_get ().abs_value); unsigned short namelen = htons (map_entry->namelen); char *name = (char *) (map_entry + 1); list = GNUNET_malloc (sizeof (struct answer_packet_list) - sizeof (struct answer_packet) + offset + 2 + ntohs (namelen)); struct answer_packet *rpkt = &list->pkt; /* The offset points to the first byte belonging to the address */ memcpy (rpkt, pkt, offset - 1); rpkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP; rpkt->hdr.size = ntohs (offset + 2 + ntohs (namelen)); memcpy (((char *) rpkt) + offset, &namelen, 2); memcpy (((char *) rpkt) + offset + 2, name, ntohs (namelen)); } else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_IP) { list = GNUNET_malloc (htons (pkt->hdr.size) + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); memcpy (&list->pkt, pkt, htons (pkt->hdr.size)); } else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA) { pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP; GNUNET_HashCode key; memset (&key, 0, sizeof (GNUNET_HashCode)); unsigned char *c = ((unsigned char *) pkt) + ntohs (pkt->addroffset); new_ip6addr_remote (c, pkt->addr, pkt->addrsize); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "New mapping to %02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x:%02x%02x\n", c[0], c[1], c[2], c[3], c[4], c[5], c[6], c[7], c[8], c[9], c[10], c[11], c[12], c[13], c[14], c[15]); unsigned char *k = (unsigned char *) &key; /* * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table) */ unsigned int i; for (i = 0; i < 16; i++) k[15 - i] = c[i]; uint16_t namelen = strlen ((char *) pkt->data + 12) + 1; struct map_entry *value = GNUNET_malloc (sizeof (struct map_entry) + namelen); char *name = (char *) (value + 1); value->namelen = namelen; memcpy (name, pkt->data + 12, namelen); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize); value->addrlen = pkt->addrsize; memcpy (&value->addr, &pkt->addr, pkt->addrsize); memset (value->additional_ports, 0, 8192); memcpy (&value->hash, &key, sizeof (GNUNET_HashCode)); if (GNUNET_NO == GNUNET_CONTAINER_multihashmap_contains (hashmap, &key)) { GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value, GNUNET_TIME_absolute_get ().abs_value); if (GNUNET_CONTAINER_heap_get_size (heap) > max_mappings) GNUNET_SCHEDULER_add_now (collect_mappings, NULL); } else GNUNET_free (value); list = GNUNET_malloc (htons (pkt->hdr.size) + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); memcpy (&list->pkt, pkt, htons (pkt->hdr.size)); } else if (pkt->subtype == GNUNET_DNS_ANSWER_TYPE_REMOTE_A) { pkt->subtype = GNUNET_DNS_ANSWER_TYPE_IP; GNUNET_HashCode key; memset (&key, 0, sizeof (GNUNET_HashCode)); unsigned char *c = ((unsigned char *) pkt) + ntohs (pkt->addroffset); new_ip4addr_remote (c, pkt->addr, pkt->addrsize); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "New mapping to %d.%d.%d.%d\n", c[0], c[1], c[2], c[3]); unsigned char *k = (unsigned char *) &key; /* * Copy the newly generated ip-address to the key backwards (as only the first part is used in the hash-table) */ unsigned int i; for (i = 0; i < 4; i++) k[3 - i] = c[i]; uint16_t namelen = strlen ((char *) pkt->data + 12) + 1; struct map_entry *value = GNUNET_malloc (sizeof (struct map_entry) + namelen); char *name = (char *) (value + 1); value->namelen = namelen; memcpy (name, pkt->data + 12, namelen); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Setting addrlen to %d\n", pkt->addrsize); value->addrlen = pkt->addrsize; memcpy (&value->addr, &pkt->addr, pkt->addrsize); memset (value->additional_ports, 0, 8192); memcpy (&value->hash, &key, sizeof (GNUNET_HashCode)); if (GNUNET_NO == GNUNET_CONTAINER_multihashmap_contains (hashmap, &key)) { GNUNET_CONTAINER_multihashmap_put (hashmap, &key, value, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY); value->heap_node = GNUNET_CONTAINER_heap_insert (heap, value, GNUNET_TIME_absolute_get ().abs_value); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Mapping is saved in the hashmap with key %08x.\n", *((uint32_t *) (&key))); if (GNUNET_CONTAINER_heap_get_size (heap) > max_mappings) GNUNET_SCHEDULER_add_now (collect_mappings, NULL); } else GNUNET_free (value); list = GNUNET_malloc (htons (pkt->hdr.size) + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); memcpy (&list->pkt, pkt, htons (pkt->hdr.size)); } else { GNUNET_break (0); GNUNET_free (pkt); return; } GNUNET_free (pkt); GNUNET_CONTAINER_DLL_insert_after (answer_proc_head, answer_proc_tail, answer_proc_tail, list); schedule_helper_write (GNUNET_TIME_UNIT_FOREVER_REL, NULL); return; } /** * Sets a bit active in a bitArray. * * @param bitArray memory area to set the bit in * @param bitIdx which bit to set */ void setBit (char *bitArray, unsigned int bitIdx) { size_t arraySlot; unsigned int targetBit; arraySlot = bitIdx / 8; targetBit = (1L << (bitIdx % 8)); bitArray[arraySlot] |= targetBit; } /** * Clears a bit from bitArray. * * @param bitArray memory area to set the bit in * @param bitIdx which bit to unset */ void clearBit (char *bitArray, unsigned int bitIdx) { size_t slot; unsigned int targetBit; slot = bitIdx / 8; targetBit = (1L << (bitIdx % 8)); bitArray[slot] = bitArray[slot] & (~targetBit); } /** * Checks if a bit is active in the bitArray * * @param bitArray memory area to set the bit in * @param bitIdx which bit to test * @return GNUNET_YES if the bit is set, GNUNET_NO if not. */ int testBit (char *bitArray, unsigned int bitIdx) { size_t slot; unsigned int targetBit; slot = bitIdx / 8; targetBit = (1L << (bitIdx % 8)); if (bitArray[slot] & targetBit) return GNUNET_YES; else return GNUNET_NO; } /** * @brief Add the port to the list of additional ports in the map_entry * * @param me the map_entry * @param port the port in host-byte-order */ static void add_additional_port (struct map_entry *me, uint16_t port) { setBit (me->additional_ports, port); } static int receive_udp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel, void **tunnel_ctx, const struct GNUNET_PeerIdentity *sender, const struct GNUNET_MessageHeader *message, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1); struct remote_addr *s = (struct remote_addr *) desc; struct udp_pkt *pkt = (struct udp_pkt *) (desc + 1); const struct GNUNET_PeerIdentity *other = sender; struct tunnel_state *ts = *tunnel_ctx; if (16 == ts->addrlen) { size_t size = sizeof (struct ip6_udp) + ntohs (pkt->len) - 1 - sizeof (struct udp_pkt); struct ip6_udp *pkt6 = alloca (size); GNUNET_assert (pkt6 != NULL); if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK) new_ip6addr (pkt6->ip6_hdr.sadr, &other->hashPubKey, desc); else new_ip6addr_remote (pkt6->ip6_hdr.sadr, s->addr, s->addrlen); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs (message->size), ntohs (pkt->len)); pkt6->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); pkt6->shdr.size = htons (size); pkt6->tun.flags = 0; pkt6->tun.type = htons (0x86dd); pkt6->ip6_hdr.version = 6; pkt6->ip6_hdr.tclass_h = 0; pkt6->ip6_hdr.tclass_l = 0; pkt6->ip6_hdr.flowlbl = 0; pkt6->ip6_hdr.paylgth = pkt->len; pkt6->ip6_hdr.nxthdr = IPPROTO_UDP; pkt6->ip6_hdr.hoplmt = 0xff; { char *ipv6addr; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr)); inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr); GNUNET_free (ipv6addr); } memcpy (&pkt6->udp_hdr, pkt, ntohs (pkt->len)); GNUNET_HashCode *key = address6_mapping_exists (pkt6->ip6_hdr.sadr); GNUNET_assert (key != NULL); struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key); GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node, GNUNET_TIME_absolute_get ().abs_value); GNUNET_free (key); GNUNET_assert (me != NULL); if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK) { GNUNET_assert (me->desc. service_type & htonl (GNUNET_DNS_SERVICE_TYPE_UDP)); if (!port_in_ports (me->desc.ports, pkt6->udp_hdr.spt) && !testBit (me->additional_ports, ntohs (pkt6->udp_hdr.spt))) { add_additional_port (me, ntohs (pkt6->udp_hdr.spt)); } } pkt6->udp_hdr.crc = 0; uint32_t sum = 0; sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16); sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16); uint32_t tmp = (pkt6->udp_hdr.len & 0xffff); sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); tmp = htons (((pkt6->ip6_hdr.nxthdr & 0x00ff))); sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->udp_hdr, ntohs (pkt->len)); pkt6->udp_hdr.crc = calculate_checksum_end (sum); write_to_helper (pkt6, size); } else { size_t size = sizeof (struct ip_udp) + ntohs (pkt->len) - 1 - sizeof (struct udp_pkt); struct ip_udp *pkt4 = alloca (size); GNUNET_assert (pkt4 != NULL); GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK); uint32_t sadr; new_ip4addr_remote ((unsigned char *) &sadr, s->addr, s->addrlen); pkt4->ip_hdr.sadr = sadr; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Relaying calc:%d gnu:%d udp:%d bytes!\n", size, ntohs (message->size), ntohs (pkt->len)); pkt4->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); pkt4->shdr.size = htons (size); pkt4->tun.flags = 0; pkt4->tun.type = htons (0x0800); pkt4->ip_hdr.version = 4; pkt4->ip_hdr.hdr_lngth = 5; pkt4->ip_hdr.diff_serv = 0; pkt4->ip_hdr.tot_lngth = htons (20 + ntohs (pkt->len)); pkt4->ip_hdr.ident = 0; pkt4->ip_hdr.flags = 0; pkt4->ip_hdr.frag_off = 0; pkt4->ip_hdr.ttl = 255; pkt4->ip_hdr.proto = IPPROTO_UDP; pkt4->ip_hdr.chks = 0; /* Will be calculated later */ { char *ipv4addr; uint32_t dadr; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4ADDR", &ipv4addr)); inet_pton (AF_INET, ipv4addr, &dadr); GNUNET_free (ipv4addr); pkt4->ip_hdr.dadr = dadr; } memcpy (&pkt4->udp_hdr, pkt, ntohs (pkt->len)); GNUNET_HashCode *key = address4_mapping_exists (pkt4->ip_hdr.sadr); GNUNET_assert (key != NULL); struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key); GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node, GNUNET_TIME_absolute_get ().abs_value); GNUNET_free (key); GNUNET_assert (me != NULL); pkt4->udp_hdr.crc = 0; /* Optional for IPv4 */ pkt4->ip_hdr.chks = calculate_ip_checksum ((uint16_t *) & pkt4->ip_hdr, 5 * 4); write_to_helper (pkt4, size); } return GNUNET_OK; } static int receive_tcp_back (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel, void **tunnel_ctx, const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED, const struct GNUNET_MessageHeader *message, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { GNUNET_HashCode *desc = (GNUNET_HashCode *) (message + 1); struct remote_addr *s = (struct remote_addr *) desc; struct tcp_pkt *pkt = (struct tcp_pkt *) (desc + 1); const struct GNUNET_PeerIdentity *other = sender; struct tunnel_state *ts = *tunnel_ctx; size_t pktlen = ntohs (message->size) - sizeof (struct GNUNET_MessageHeader) - sizeof (GNUNET_HashCode); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received TCP-Packet back, addrlen = %d\n", s->addrlen); if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK || ts->addrlen == 16) { size_t size = pktlen + sizeof (struct ip6_tcp) - 1; struct ip6_tcp *pkt6 = alloca (size); memset (pkt6, 0, size); GNUNET_assert (pkt6 != NULL); if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK) new_ip6addr (pkt6->ip6_hdr.sadr, &other->hashPubKey, desc); else new_ip6addr_remote (pkt6->ip6_hdr.sadr, s->addr, s->addrlen); pkt6->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); pkt6->shdr.size = htons (size); pkt6->tun.flags = 0; pkt6->tun.type = htons (0x86dd); pkt6->ip6_hdr.version = 6; pkt6->ip6_hdr.tclass_h = 0; pkt6->ip6_hdr.tclass_l = 0; pkt6->ip6_hdr.flowlbl = 0; pkt6->ip6_hdr.paylgth = htons (pktlen); pkt6->ip6_hdr.nxthdr = IPPROTO_TCP; pkt6->ip6_hdr.hoplmt = 0xff; { char *ipv6addr; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr)); inet_pton (AF_INET6, ipv6addr, pkt6->ip6_hdr.dadr); GNUNET_free (ipv6addr); } memcpy (&pkt6->tcp_hdr, pkt, pktlen); GNUNET_HashCode *key = address6_mapping_exists (pkt6->ip6_hdr.sadr); GNUNET_assert (key != NULL); struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key); GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node, GNUNET_TIME_absolute_get ().abs_value); GNUNET_free (key); GNUNET_assert (me != NULL); if (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK) GNUNET_assert (me->desc. service_type & htonl (GNUNET_DNS_SERVICE_TYPE_TCP)); pkt6->tcp_hdr.crc = 0; uint32_t sum = 0; uint32_t tmp; sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.sadr, 16); sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->ip6_hdr.dadr, 16); tmp = htonl (pktlen); sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); tmp = htonl (((pkt6->ip6_hdr.nxthdr & 0x000000ff))); sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); sum = calculate_checksum_update (sum, (uint16_t *) & pkt6->tcp_hdr, ntohs (pkt6->ip6_hdr.paylgth)); pkt6->tcp_hdr.crc = calculate_checksum_end (sum); write_to_helper (pkt6, size); } else { size_t size = pktlen + sizeof (struct ip_tcp) - 1; struct ip_tcp *pkt4 = alloca (size); GNUNET_assert (pkt4 != NULL); memset (pkt4, 0, size); GNUNET_assert (ntohs (message->type) == GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK); uint32_t sadr; new_ip4addr_remote ((unsigned char *) &sadr, s->addr, s->addrlen); pkt4->ip_hdr.sadr = sadr; pkt4->shdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_HELPER); pkt4->shdr.size = htons (size); pkt4->tun.flags = 0; pkt4->tun.type = htons (0x0800); pkt4->ip_hdr.version = 4; pkt4->ip_hdr.hdr_lngth = 5; pkt4->ip_hdr.diff_serv = 0; pkt4->ip_hdr.tot_lngth = htons (20 + pktlen); pkt4->ip_hdr.ident = 0; pkt4->ip_hdr.flags = 0; pkt4->ip_hdr.frag_off = 0; pkt4->ip_hdr.ttl = 255; pkt4->ip_hdr.proto = IPPROTO_TCP; pkt4->ip_hdr.chks = 0; /* Will be calculated later */ { char *ipv4addr; uint32_t dadr; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV4ADDR", &ipv4addr)); inet_pton (AF_INET, ipv4addr, &dadr); GNUNET_free (ipv4addr); pkt4->ip_hdr.dadr = dadr; } memcpy (&pkt4->tcp_hdr, pkt, pktlen); GNUNET_HashCode *key = address4_mapping_exists (pkt4->ip_hdr.sadr); GNUNET_assert (key != NULL); struct map_entry *me = GNUNET_CONTAINER_multihashmap_get (hashmap, key); GNUNET_CONTAINER_heap_update_cost (heap, me->heap_node, GNUNET_TIME_absolute_get ().abs_value); GNUNET_free (key); GNUNET_assert (me != NULL); pkt4->tcp_hdr.crc = 0; uint32_t sum = 0; uint32_t tmp; tmp = pkt4->ip_hdr.sadr; sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); tmp = pkt4->ip_hdr.dadr; sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); tmp = (0x06 << 16) | (0xffff & pktlen); // 0x06 for TCP? tmp = htonl (tmp); sum = calculate_checksum_update (sum, (uint16_t *) & tmp, 4); sum = calculate_checksum_update (sum, (uint16_t *) & pkt4->tcp_hdr, pktlen); pkt4->tcp_hdr.crc = calculate_checksum_end (sum); pkt4->ip_hdr.chks = calculate_ip_checksum ((uint16_t *) & pkt4->ip_hdr, 5 * 4); write_to_helper (pkt4, size); } return GNUNET_OK; } static void * new_tunnel (void *cls, struct GNUNET_MESH_Tunnel *tunnel, const struct GNUNET_PeerIdentity *initiator, const struct GNUNET_ATS_Information *atsi) { /* Why should anyone open an inbound tunnel to vpn? */ GNUNET_break (0); return NULL; } static void cleaner (void *cls, const struct GNUNET_MESH_Tunnel *tunnel, void *tunnel_ctx) { /* Why should anyone open an inbound tunnel to vpn? */ GNUNET_break (0); } /** * Main function that will be run by the scheduler. * * @param cls closure * @param args remaining command-line arguments * @param cfgfile name of the configuration file used (for saving, can be NULL!) * @param cfg_ configuration */ static void run (void *cls, char *const *args GNUNET_UNUSED, const char *cfgfile GNUNET_UNUSED, const struct GNUNET_CONFIGURATION_Handle *cfg_) { static const struct GNUNET_MESH_MessageHandler handlers[] = { {receive_udp_back, GNUNET_MESSAGE_TYPE_VPN_SERVICE_UDP_BACK, 0}, {receive_tcp_back, GNUNET_MESSAGE_TYPE_VPN_SERVICE_TCP_BACK, 0}, {receive_udp_back, GNUNET_MESSAGE_TYPE_VPN_REMOTE_UDP_BACK, 0}, {receive_tcp_back, GNUNET_MESSAGE_TYPE_VPN_REMOTE_TCP_BACK, 0}, {NULL, 0, 0} }; static const GNUNET_MESH_ApplicationType types[] = { GNUNET_APPLICATION_TYPE_END }; mesh_handle = GNUNET_MESH_connect (cfg_, 42, NULL, new_tunnel, cleaner, handlers, types); cfg = cfg_; restart_hijack = 0; hashmap = GNUNET_CONTAINER_multihashmap_create (65536); heap = GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN); GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "MAX_MAPPINGg", &max_mappings); udp_connections = GNUNET_CONTAINER_multihashmap_create (65536); conn_task = GNUNET_SCHEDULER_add_now (connect_to_service_dns, NULL); shs_task = GNUNET_SCHEDULER_add_after (conn_task, start_helper_and_schedule, NULL); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup, cls); } /** * The main function to obtain template from gnunetd. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int main (int argc, char *const *argv) { static const struct GNUNET_GETOPT_CommandLineOption options[] = { GNUNET_GETOPT_OPTION_END }; return (GNUNET_OK == GNUNET_PROGRAM_run (argc, argv, "vpn", gettext_noop ("help text"), options, &run, NULL)) ? ret : 1; } /* end of gnunet-daemon-vpn.c */