/* This file is part of GNUnet. (C) 2009 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 vpn/gnunet-service-dns.c * @author Philipp Toelke */ #include "platform.h" #include "gnunet_getopt_lib.h" #include "gnunet_service_lib.h" #include #include "gnunet_network_lib.h" #include "gnunet_os_lib.h" #include "gnunet-service-dns-p.h" #include "gnunet_connection_lib.h" #include "gnunet_protocols.h" #include "gnunet_applications.h" #include "gnunet-vpn-packet.h" #include "gnunet_container_lib.h" #include "gnunet-dns-parser.h" #include "gnunet_dht_service.h" #include "gnunet_block_lib.h" #include "block_dns.h" #include "gnunet_crypto_lib.h" #include "gnunet_mesh_service.h" #include "gnunet_signatures.h" struct GNUNET_MESH_Handle *mesh_handle; struct GNUNET_CONNECTION_TransmitHandle *server_notify; /** * The UDP-Socket through which DNS-Resolves will be sent if they are not to be * sent through gnunet. The port of this socket will not be hijacked. */ static struct GNUNET_NETWORK_Handle *dnsout; static struct GNUNET_NETWORK_Handle *dnsout6; /** * The port bound to the socket dnsout */ static unsigned short dnsoutport; /** * A handle to the DHT-Service */ static struct GNUNET_DHT_Handle *dht; /** * The configuration to use */ static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * A list of DNS-Responses that have to be sent to the requesting client */ static struct answer_packet_list *head; /** * The tail of the list of DNS-responses */ static struct answer_packet_list *tail; /** * A structure containing a mapping from network-byte-ordered DNS-id (16 bit) to * some information needed to handle this query * * It currently allocates at least * (1 + machine-width + machine-width + 32 + 32 + 16 + machine-width + 8) * 65536 bit * = 17 MiB on 64 bit. * = 11 MiB on 32 bit. */ static struct { unsigned valid:1; struct GNUNET_SERVER_Client *client; struct GNUNET_MESH_Tunnel *tunnel; char local_ip[16]; char remote_ip[16]; char addrlen; uint16_t local_port; char *name; uint8_t namelen; uint16_t qtype; } query_states[UINT16_MAX + 1]; /** * A struct used to give more than one value as * closure to receive_dht */ struct receive_dht_cls { uint16_t id; struct GNUNET_DHT_GetHandle *handle; }; struct tunnel_notify_queue { struct tunnel_notify_queue *next; struct tunnel_notify_queue *prev; void *cls; size_t len; GNUNET_CONNECTION_TransmitReadyNotify cb; }; struct tunnel_state { struct tunnel_notify_queue *head, *tail; struct GNUNET_MESH_TransmitHandle *th; }; static size_t send_answer (void *cls, size_t size, void *buf); static void client_disconnect (void *cls, struct GNUNET_SERVER_Client *client) { if (NULL == head) return; if (head->client == client) { GNUNET_CONNECTION_notify_transmit_ready_cancel (server_notify); server_notify = GNUNET_SERVER_notify_transmit_ready (head->next->client, ntohs (head->next->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); } struct answer_packet_list *element = head; while (element != NULL) { if (element->client == client) { GNUNET_SERVER_client_drop (client); GNUNET_CONTAINER_DLL_remove (head, tail, element); struct answer_packet_list *t = element; element = element->next; GNUNET_free (t); } else element = element->next; } } /** * Hijack all outgoing DNS-Traffic but for traffic leaving "our" port. */ static void hijack (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; if (0 == dnsoutport) { GNUNET_log (GNUNET_ERROR_TYPE_INFO, "Delaying the hijacking, port is still %d!\n", dnsoutport); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &hijack, NULL); return; } char port_s[6]; char *virt_dns; struct GNUNET_OS_Process *proc; if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS' in configuration!\n"); exit (1); } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Hijacking, port is %d\n", dnsoutport); snprintf (port_s, 6, "%d", dnsoutport); if (NULL != (proc = GNUNET_OS_start_process (NULL, NULL, "gnunet-helper-hijack-dns", "gnunet-hijack-dns", port_s, virt_dns, NULL))) { GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (proc)); GNUNET_OS_process_close (proc); } GNUNET_free (virt_dns); } static void * new_tunnel (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel, const struct GNUNET_PeerIdentity *initiator GNUNET_UNUSED, const struct GNUNET_ATS_Information *ats GNUNET_UNUSED) { struct tunnel_state *s = GNUNET_malloc (sizeof *s); s->head = NULL; s->tail = NULL; s->th = NULL; return s; } static void clean_tunnel (void *cls GNUNET_UNUSED, const struct GNUNET_MESH_Tunnel *tunnel, void *tunnel_ctx) { GNUNET_free (tunnel_ctx); } /** * Delete the hijacking-routes */ static void unhijack (unsigned short port) { char port_s[6]; char *virt_dns; struct GNUNET_OS_Process *proc; if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS' in configuration!\n"); exit (1); } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "unHijacking, port is %d\n", port); snprintf (port_s, 6, "%d", port); if (NULL != (proc = GNUNET_OS_start_process (NULL, NULL, "gnunet-helper-hijack-dns", "gnunet-hijack-dns", "-d", port_s, virt_dns, NULL))) { GNUNET_break (GNUNET_OK == GNUNET_OS_process_wait (proc)); GNUNET_OS_process_close (proc); } GNUNET_free (virt_dns); } /** * Send the DNS-Response to the client. Gets called via the notify_transmit_ready- * system. */ static size_t send_answer (void *cls, size_t size, void *buf) { server_notify = NULL; struct answer_packet_list *query = head; size_t len = ntohs (query->pkt.hdr.size); GNUNET_assert (len <= size); memcpy (buf, &query->pkt.hdr, len); GNUNET_CONTAINER_DLL_remove (head, tail, query); /* When more data is to be sent, reschedule */ if (head != NULL) server_notify = GNUNET_SERVER_notify_transmit_ready (head->client, ntohs (head->pkt.hdr.size), GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); GNUNET_SERVER_client_drop (query->client); GNUNET_free (query); return len; } struct tunnel_cls { struct GNUNET_MESH_Tunnel *tunnel GNUNET_PACKED; struct GNUNET_MessageHeader hdr; struct dns_pkt dns; }; struct tunnel_cls *remote_pending[UINT16_MAX]; static size_t mesh_send_response (void *cls, size_t size, void *buf) { GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader)); struct GNUNET_MessageHeader *hdr = buf; uint32_t *sz = cls; struct GNUNET_MESH_Tunnel **tunnel = (struct GNUNET_MESH_Tunnel **) (sz + 1); struct dns_pkt *dns = (struct dns_pkt *) (tunnel + 1); GNUNET_MESH_tunnel_set_data (*tunnel, NULL); hdr->type = htons (GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS); hdr->size = htons (*sz + sizeof (struct GNUNET_MessageHeader)); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sending response, size=%d, sz=%d, sz+hdr=%d\n", size, *sz, *sz + sizeof (struct GNUNET_MessageHeader)); GNUNET_assert (size >= (*sz + sizeof (struct GNUNET_MessageHeader))); memcpy (hdr + 1, dns, *sz); struct tunnel_state *s = GNUNET_MESH_tunnel_get_data (*tunnel); if (NULL != s->head) { struct tunnel_notify_queue *element = s->head; struct tunnel_notify_queue *head = s->head; struct tunnel_notify_queue *tail = s->tail; GNUNET_CONTAINER_DLL_remove (head, tail, element); s->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, element->cb, element->cls); } GNUNET_free (cls); return ntohs (hdr->size); } static size_t mesh_send (void *cls, size_t size, void *buf) { struct tunnel_cls *cls_ = (struct tunnel_cls *) cls; GNUNET_MESH_tunnel_set_data (cls_->tunnel, NULL); GNUNET_assert (cls_->hdr.size <= size); size = cls_->hdr.size; cls_->hdr.size = htons (cls_->hdr.size); memcpy (buf, &cls_->hdr, size); struct tunnel_state *s = GNUNET_MESH_tunnel_get_data (cls_->tunnel); if (NULL != s->head) { struct tunnel_notify_queue *element = s->head; struct tunnel_notify_queue *head = s->head; struct tunnel_notify_queue *tail = s->tail;; GNUNET_CONTAINER_DLL_remove (head, tail, element); s->th = GNUNET_MESH_notify_transmit_ready (cls_->tunnel, GNUNET_NO, 42, GNUNET_TIME_relative_divide (GNUNET_CONSTANTS_MAX_CORK_DELAY, 2), (const struct GNUNET_PeerIdentity *) NULL, element->len, element->cb, element->cls); GNUNET_free (element); } return size; } void mesh_connect (void *cls, const struct GNUNET_PeerIdentity *peer, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { if (NULL == peer) return; struct tunnel_cls *cls_ = (struct tunnel_cls *) cls; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connected to peer %s, %x, sending query with id %d\n", GNUNET_i2s (peer), peer, ntohs (cls_->dns.s.id)); struct tunnel_state *s = GNUNET_MESH_tunnel_get_data (cls_->tunnel); if (NULL == s->head) { s->th = GNUNET_MESH_notify_transmit_ready (cls_->tunnel, GNUNET_YES, 42, GNUNET_TIME_UNIT_MINUTES, NULL, cls_->hdr.size, mesh_send, cls); } else { struct tunnel_notify_queue *head = s->head; struct tunnel_notify_queue *tail = s->tail; struct tunnel_notify_queue *element = GNUNET_malloc (sizeof (struct tunnel_notify_queue)); element->cls = cls; element->len = cls_->hdr.size; element->cb = mesh_send; GNUNET_CONTAINER_DLL_insert_tail (head, tail, element); } } static void send_mesh_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; struct tunnel_cls *cls_ = (struct tunnel_cls *) cls; struct tunnel_state *s = GNUNET_malloc (sizeof *s); s->head = NULL; s->tail = NULL; s->th = NULL; cls_->tunnel = GNUNET_MESH_tunnel_create (mesh_handle, s, mesh_connect, NULL, cls_); GNUNET_MESH_peer_request_connect_by_type (cls_->tunnel, GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER); remote_pending[cls_->dns.s.id] = cls_; } static int receive_mesh_query (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel, void **ctx GNUNET_UNUSED, const struct GNUNET_PeerIdentity *sender GNUNET_UNUSED, const struct GNUNET_MessageHeader *message, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { struct dns_pkt *dns = (struct dns_pkt *) (message + 1); struct sockaddr_in dest; struct dns_pkt_parsed *pdns = parse_dns_packet (dns); memset (&dest, 0, sizeof dest); dest.sin_port = htons (53); char *dns_resolver; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (cfg, "dns", "EXTERNAL_DNS", &dns_resolver) || 1 != inet_pton (AF_INET, dns_resolver, &dest.sin_addr)) inet_pton (AF_INET, "8.8.8.8", &dest.sin_addr); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Querying for remote, id=%d\n", ntohs (dns->s.id)); query_states[dns->s.id].tunnel = tunnel; query_states[dns->s.id].valid = GNUNET_YES; int i; for (i = 0; i < ntohs (pdns->s.qdcount); i++) { if (pdns->queries[i]->qtype == htons (28) || pdns->queries[i]->qtype == htons (1)) { query_states[dns->s.id].qtype = pdns->queries[i]->qtype; break; } } free_parsed_dns_packet (pdns); GNUNET_NETWORK_socket_sendto (dnsout, dns, ntohs (message->size) - sizeof (struct GNUNET_MessageHeader), (struct sockaddr *) &dest, sizeof dest); return GNUNET_SYSERR; } static int receive_mesh_answer (void *cls GNUNET_UNUSED, struct GNUNET_MESH_Tunnel *tunnel, void **ctx GNUNET_UNUSED, const struct GNUNET_PeerIdentity *sender, const struct GNUNET_MessageHeader *message, const struct GNUNET_ATS_Information *atsi GNUNET_UNUSED) { /* TODo: size check */ struct dns_pkt *dns = (struct dns_pkt *) (message + 1); /* They sent us a packet we were not waiting for */ if (remote_pending[dns->s.id] == NULL || remote_pending[dns->s.id]->tunnel != tunnel) return GNUNET_OK; GNUNET_free (remote_pending[dns->s.id]); remote_pending[dns->s.id] = NULL; if (query_states[dns->s.id].valid != GNUNET_YES) return GNUNET_SYSERR; query_states[dns->s.id].valid = GNUNET_NO; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received answer from peer %s, dns-id %d\n", GNUNET_i2s (sender), ntohs (dns->s.id)); size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + query_states[dns->s.id].namelen + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */ + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */ struct answer_packet_list *answer = GNUNET_malloc (len + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS); answer->pkt.hdr.size = htons (len); struct dns_pkt_parsed *pdns = parse_dns_packet (dns); if (ntohs (pdns->s.ancount) < 1) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer only contains %d answers.\n", ntohs (pdns->s.ancount)); free_parsed_dns_packet (pdns); GNUNET_free (answer); return GNUNET_OK; } int i = 0; while (i < ntohs (pdns->s.ancount) && ntohs (pdns->answers[i]->type) != 28 && ntohs (pdns->answers[i]->type) != 1) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer contains %d.\n", ntohs (pdns->answers[i]->type)); i++; } if (i >= ntohs (pdns->s.ancount)) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer does not contain any usable answers.\n"); free_parsed_dns_packet (pdns); GNUNET_free (answer); return GNUNET_OK; } answer->pkt.addrsize = ntohs (pdns->answers[i]->data_len); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "The first answer has the addrlen %d\n", answer->pkt.addrsize); memcpy (answer->pkt.addr, pdns->answers[i]->data, ntohs (pdns->answers[i]->data_len)); memcpy (answer->pkt.from, query_states[dns->s.id].remote_ip, query_states[dns->s.id].addrlen); memcpy (answer->pkt.to, query_states[dns->s.id].local_ip, query_states[dns->s.id].addrlen); answer->pkt.addrlen = query_states[dns->s.id].addrlen; answer->pkt.dst_port = query_states[dns->s.id].local_port; struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data; dpkt->s.id = dns->s.id; dpkt->s.aa = 1; dpkt->s.qr = 1; dpkt->s.ra = 1; dpkt->s.qdcount = htons (1); dpkt->s.ancount = htons (1); memcpy (dpkt->data, query_states[dns->s.id].name, query_states[dns->s.id].namelen); GNUNET_free (query_states[dns->s.id].name); query_states[dns->s.id].name = NULL; struct dns_query_line *dque = (struct dns_query_line *) (dpkt->data + (query_states[dns->s.id].namelen)); struct dns_record_line *drec_data = (struct dns_record_line *) (dpkt->data + (query_states[dns->s.id].namelen) + sizeof (struct dns_query_line) + 2); if (htons (28) == query_states[dns->s.id].qtype) { answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_AAAA; dque->type = htons (28); /* AAAA */ drec_data->type = htons (28); /* AAAA */ drec_data->data_len = htons (16); } else if (htons (1) == query_states[dns->s.id].qtype) { answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REMOTE_A; dque->type = htons (1); /* A */ drec_data->type = htons (1); /* A */ drec_data->data_len = htons (4); } else { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "dns-answer with pending qtype = %d\n", query_states[dns->s.id].qtype); GNUNET_assert (0); } dque->class = htons (1); /* IN */ char *anname = (char *) (dpkt->data + (query_states[dns->s.id].namelen) + sizeof (struct dns_query_line)); memcpy (anname, "\xc0\x0c", 2); drec_data->class = htons (1); /* IN */ drec_data->ttl = pdns->answers[i]->ttl; /* Calculate at which offset in the packet the IPv6-Address belongs, it is * filled in by the daemon-vpn */ answer->pkt.addroffset = htons ((unsigned short) ((unsigned long) (&drec_data->data) - (unsigned long) (&answer->pkt))); GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer); answer->client = query_states[dns->s.id].client; if (server_notify == NULL) server_notify = GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client, len, GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Sent answer of length %d on to client, addroffset = %d\n", len, answer->pkt.addroffset); free_parsed_dns_packet (pdns); return GNUNET_OK; } static void send_rev_query (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc) { if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; struct dns_pkt_parsed *pdns = (struct dns_pkt_parsed *) cls; unsigned short id = pdns->s.id; free_parsed_dns_packet (pdns); if (query_states[id].valid != GNUNET_YES) return; query_states[id].valid = GNUNET_NO; GNUNET_assert (query_states[id].namelen == 74); size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + 74 /* this is the length of a reverse ipv6-lookup */ + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */ + sizeof (struct dns_record_line) - 1 - 2 /* We do not know the lenght of the answer yet */ ; struct answer_packet_list *answer = GNUNET_malloc (len + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS); answer->pkt.hdr.size = htons (len); answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_REV; memcpy (answer->pkt.from, query_states[id].remote_ip, query_states[id].addrlen); memcpy (answer->pkt.to, query_states[id].local_ip, query_states[id].addrlen); answer->pkt.dst_port = query_states[id].local_port; struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data; dpkt->s.id = id; dpkt->s.aa = 1; dpkt->s.qr = 1; dpkt->s.ra = 1; dpkt->s.qdcount = htons (1); dpkt->s.ancount = htons (1); memcpy (dpkt->data, query_states[id].name, query_states[id].namelen); GNUNET_free (query_states[id].name); query_states[id].name = NULL; struct dns_query_line *dque = (struct dns_query_line *) (dpkt->data + (query_states[id].namelen)); dque->type = htons (12); /* PTR */ dque->class = htons (1); /* IN */ char *anname = (char *) (dpkt->data + (query_states[id].namelen) + sizeof (struct dns_query_line)); memcpy (anname, "\xc0\x0c", 2); struct dns_record_line *drec_data = (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) + sizeof (struct dns_query_line) + 2); drec_data->type = htons (12); /* AAAA */ drec_data->class = htons (1); /* IN */ /* FIXME: read the TTL from block: * GNUNET_TIME_absolute_get_remaining(rec->expiration_time) * * But how to get the seconds out of this? */ drec_data->ttl = htonl (3600); /* Calculate at which offset in the packet the length of the name and the * name, it is filled in by the daemon-vpn */ answer->pkt.addroffset = htons ((unsigned short) ((unsigned long) (&drec_data->data_len) - (unsigned long) (&answer->pkt))); GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer); answer->client = query_states[id].client; if (server_notify == NULL) server_notify = GNUNET_SERVER_notify_transmit_ready (query_states[id].client, len, GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); } /** * Receive a block from the dht. */ static void receive_dht (void *cls, struct GNUNET_TIME_Absolute exp GNUNET_UNUSED, const GNUNET_HashCode * key GNUNET_UNUSED, const struct GNUNET_PeerIdentity *get_path GNUNET_UNUSED, unsigned int get_path_length GNUNET_UNUSED, const struct GNUNET_PeerIdentity *put_path GNUNET_UNUSED, unsigned int put_path_length GNUNET_UNUSED, enum GNUNET_BLOCK_Type type, size_t size, const void *data) { unsigned short id = ((struct receive_dht_cls *) cls)->id; struct GNUNET_DHT_GetHandle *handle = ((struct receive_dht_cls *) cls)->handle; GNUNET_free (cls); GNUNET_DHT_get_stop (handle); GNUNET_assert (type == GNUNET_BLOCK_TYPE_DNS); /* If no query with this id is pending, ignore the block */ if (query_states[id].valid != GNUNET_YES) return; query_states[id].valid = GNUNET_NO; const struct GNUNET_DNS_Record *rec = data; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Got block of size %d, peer: %08x, desc: %08x\n", size, *((unsigned int *) &rec->peer), *((unsigned int *) &rec->service_descriptor)); size_t len = sizeof (struct answer_packet) - 1 + sizeof (struct dns_static) + query_states[id].namelen + sizeof (struct dns_query_line) + 2 /* To hold the pointer (as defined in RFC1035) to the name */ + sizeof (struct dns_record_line) - 1 + 16; /* To hold the IPv6-Address */ struct answer_packet_list *answer = GNUNET_malloc (len + sizeof (struct answer_packet_list) - sizeof (struct answer_packet)); answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS); answer->pkt.hdr.size = htons (len); answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_SERVICE; answer->client = query_states[id].client; GNUNET_CRYPTO_hash (&rec->peer, sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded), &answer->pkt.service_descr.peer); memcpy (&answer->pkt.service_descr.service_descriptor, &rec->service_descriptor, sizeof (GNUNET_HashCode)); memcpy (&answer->pkt.service_descr.service_type, &rec->service_type, sizeof (answer->pkt.service_descr.service_type)); memcpy (&answer->pkt.service_descr.ports, &rec->ports, sizeof (answer->pkt.service_descr.ports)); memcpy (answer->pkt.from, query_states[id].remote_ip, query_states[id].addrlen); memcpy (answer->pkt.to, query_states[id].local_ip, query_states[id].addrlen); answer->pkt.addrlen = query_states[id].addrlen; answer->pkt.dst_port = query_states[id].local_port; struct dns_pkt *dpkt = (struct dns_pkt *) answer->pkt.data; dpkt->s.id = id; dpkt->s.aa = 1; dpkt->s.qr = 1; dpkt->s.ra = 1; dpkt->s.qdcount = htons (1); dpkt->s.ancount = htons (1); memcpy (dpkt->data, query_states[id].name, query_states[id].namelen); GNUNET_free (query_states[id].name); query_states[id].name = NULL; struct dns_query_line *dque = (struct dns_query_line *) (dpkt->data + (query_states[id].namelen)); dque->type = htons (28); /* AAAA */ dque->class = htons (1); /* IN */ char *anname = (char *) (dpkt->data + (query_states[id].namelen) + sizeof (struct dns_query_line)); memcpy (anname, "\xc0\x0c", 2); struct dns_record_line *drec_data = (struct dns_record_line *) (dpkt->data + (query_states[id].namelen) + sizeof (struct dns_query_line) + 2); drec_data->type = htons (28); /* AAAA */ drec_data->class = htons (1); /* IN */ /* FIXME: read the TTL from block: * GNUNET_TIME_absolute_get_remaining(rec->expiration_time) * * But how to get the seconds out of this? */ drec_data->ttl = htonl (3600); drec_data->data_len = htons (16); /* Calculate at which offset in the packet the IPv6-Address belongs, it is * filled in by the daemon-vpn */ answer->pkt.addroffset = htons ((unsigned short) ((unsigned long) (&drec_data->data) - (unsigned long) (&answer->pkt))); GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer); if (server_notify == NULL) server_notify = GNUNET_SERVER_notify_transmit_ready (answer->client, len, GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); } /** * This receives a GNUNET_MESSAGE_TYPE_REHIJACK and rehijacks the DNS */ static void rehijack (void *cls GNUNET_UNUSED, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message GNUNET_UNUSED) { unhijack (dnsoutport); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &hijack, NULL); GNUNET_SERVER_receive_done (client, GNUNET_OK); } /** * This receives the dns-payload from the daemon-vpn and sends it on over the udp-socket */ static void receive_query (void *cls GNUNET_UNUSED, struct GNUNET_SERVER_Client *client, const struct GNUNET_MessageHeader *message) { struct query_packet *pkt = (struct query_packet *) message; struct dns_pkt *dns = (struct dns_pkt *) pkt->data; struct dns_pkt_parsed *pdns = parse_dns_packet (dns); query_states[dns->s.id].valid = GNUNET_YES; query_states[dns->s.id].client = client; GNUNET_SERVER_client_keep (client); memcpy (query_states[dns->s.id].local_ip, pkt->orig_from, pkt->addrlen); query_states[dns->s.id].addrlen = pkt->addrlen; query_states[dns->s.id].local_port = pkt->src_port; memcpy (query_states[dns->s.id].remote_ip, pkt->orig_to, pkt->addrlen); query_states[dns->s.id].namelen = strlen ((char *) dns->data) + 1; if (query_states[dns->s.id].name != NULL) GNUNET_free (query_states[dns->s.id].name); query_states[dns->s.id].name = GNUNET_malloc (query_states[dns->s.id].namelen); memcpy (query_states[dns->s.id].name, dns->data, query_states[dns->s.id].namelen); int i; for (i = 0; i < ntohs (pdns->s.qdcount); i++) { if (pdns->queries[i]->qtype == htons (28) || pdns->queries[i]->qtype == htons (1)) { query_states[dns->s.id].qtype = pdns->queries[i]->qtype; break; } } /* The query is for a .gnunet-address */ if (pdns->queries[0]->namelen > 9 && 0 == strncmp (pdns->queries[0]->name + (pdns->queries[0]->namelen - 9), ".gnunet.", 9)) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for .gnunet!\n"); GNUNET_HashCode key; GNUNET_CRYPTO_hash (pdns->queries[0]->name, pdns->queries[0]->namelen, &key); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Getting with key %08x, len is %d\n", *((unsigned int *) &key), pdns->queries[0]->namelen); struct receive_dht_cls *cls = GNUNET_malloc (sizeof (struct receive_dht_cls)); cls->id = dns->s.id; cls->handle = GNUNET_DHT_get_start (dht, GNUNET_TIME_UNIT_MINUTES, GNUNET_BLOCK_TYPE_DNS, &key, 5 /* DEFAULT_GET_REPLICATION */ , GNUNET_DHT_RO_NONE, NULL, 0, &receive_dht, cls); goto outfree; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Query for '%s'; namelen=%d\n", pdns->queries[0]->name, pdns->queries[0]->namelen); /* This is a PTR-Query. Check if it is for "our" network */ if (htons (pdns->queries[0]->qtype) == 12 && 74 == pdns->queries[0]->namelen) { char *ipv6addr; char ipv6[16]; char ipv6rev[74] = "X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.X.ip6.arpa."; unsigned int i; unsigned long long ipv6prefix; unsigned int comparelen; GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "IPV6ADDR", &ipv6addr)); inet_pton (AF_INET6, ipv6addr, ipv6); GNUNET_free (ipv6addr); GNUNET_assert (GNUNET_OK == GNUNET_CONFIGURATION_get_value_number (cfg, "vpn", "IPV6PREFIX", &ipv6prefix)); GNUNET_assert (ipv6prefix < 127); ipv6prefix = (ipv6prefix + 7) / 8; for (i = ipv6prefix; i < 16; i++) ipv6[i] = 0; for (i = 0; i < 16; i++) { unsigned char c1 = ipv6[i] >> 4; unsigned char c2 = ipv6[i] & 0xf; if (c1 <= 9) ipv6rev[62 - (4 * i)] = c1 + '0'; else ipv6rev[62 - (4 * i)] = c1 + 87; /* 87 is the difference between 'a' and 10 */ if (c2 <= 9) ipv6rev[62 - ((4 * i) + 2)] = c2 + '0'; else ipv6rev[62 - ((4 * i) + 2)] = c2 + 87; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "My network is %s'.\n", ipv6rev); comparelen = 10 + 4 * ipv6prefix; if (0 == strncmp (pdns->queries[0]->name + (pdns->queries[0]->namelen - comparelen), ipv6rev + (74 - comparelen), comparelen)) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Reverse-Query for .gnunet!\n"); GNUNET_SCHEDULER_add_now (send_rev_query, pdns); goto out; } } unsigned char virt_dns_bytes[16]; if (pkt->addrlen == 4) { char *virt_dns; if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS", &virt_dns)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS' in configuration!\n"); exit (1); } if (1 != inet_pton (AF_INET, virt_dns, &virt_dns_bytes)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Error parsing 'VIRTDNS': %s; %m!\n", virt_dns); exit (1); } GNUNET_free (virt_dns); } else if (pkt->addrlen == 16) { char *virt_dns; if (GNUNET_SYSERR == GNUNET_CONFIGURATION_get_value_string (cfg, "vpn", "VIRTDNS6", &virt_dns)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "No entry 'VIRTDNS6' in configuration!\n"); exit (1); } if (1 != inet_pton (AF_INET6, virt_dns, &virt_dns_bytes)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Error parsing 'VIRTDNS6': %s; %m!\n", virt_dns); exit (1); } GNUNET_free (virt_dns); } else { GNUNET_assert (0); } if (memcmp (virt_dns_bytes, pkt->orig_to, pkt->addrlen) == 0) { /* This is a packet that was sent directly to the virtual dns-server * * This means we have to send this query over gnunet */ size_t size = sizeof (struct GNUNET_MESH_Tunnel *) + sizeof (struct GNUNET_MessageHeader) + (ntohs (message->size) - sizeof (struct query_packet) + 1); struct tunnel_cls *cls_ = GNUNET_malloc (size); cls_->hdr.size = size - sizeof (struct GNUNET_MESH_Tunnel *); cls_->hdr.type = ntohs (GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size); memcpy (&cls_->dns, dns, cls_->hdr.size - sizeof (struct GNUNET_MessageHeader)); GNUNET_SCHEDULER_add_now (send_mesh_query, cls_); if (ntohs (pdns->s.qdcount) == 1) { if (ntohs (pdns->queries[0]->qtype) == 1) pdns->queries[0]->qtype = htons (28); else if (ntohs (pdns->queries[0]->qtype) == 28) pdns->queries[0]->qtype = htons (1); else { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "not sending second packet\n"); goto outfree; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "sending second packet\n"); struct dns_pkt *rdns = unparse_dns_packet (pdns); size_t size = sizeof (struct GNUNET_MESH_Tunnel *) + sizeof (struct GNUNET_MessageHeader) + (ntohs (message->size) - sizeof (struct query_packet) + 1); struct tunnel_cls *cls_ = GNUNET_malloc (size); cls_->hdr.size = size - sizeof (struct GNUNET_MESH_Tunnel *); cls_->hdr.type = ntohs (GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "size: %d\n", size); memcpy (&cls_->dns, rdns, cls_->hdr.size - sizeof (struct GNUNET_MessageHeader)); GNUNET_SCHEDULER_add_now (send_mesh_query, cls_); GNUNET_free (rdns); } goto outfree; } /* The query should be sent to the network */ if (pkt->addrlen == 4) { struct sockaddr_in dest; memset (&dest, 0, sizeof dest); dest.sin_port = htons (53); memcpy (&dest.sin_addr.s_addr, pkt->orig_to, pkt->addrlen); GNUNET_NETWORK_socket_sendto (dnsout, dns, ntohs (pkt->hdr.size) - sizeof (struct query_packet) + 1, (struct sockaddr *) &dest, sizeof dest); } else if (pkt->addrlen == 16) { struct sockaddr_in6 dest; memset (&dest, 0, sizeof dest); dest.sin6_port = htons (53); memcpy (&dest.sin6_addr, pkt->orig_to, pkt->addrlen); GNUNET_NETWORK_socket_sendto (dnsout6, dns, ntohs (pkt->hdr.size) - sizeof (struct query_packet) + 1, (struct sockaddr *) &dest, sizeof dest); } outfree: free_parsed_dns_packet (pdns); pdns = NULL; out: GNUNET_SERVER_receive_done (client, GNUNET_OK); } static void read_response (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); static void read_response6 (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc); static int open_port6 () { struct sockaddr_in6 addr; dnsout6 = GNUNET_NETWORK_socket_create (AF_INET6, SOCK_DGRAM, 0); if (dnsout6 == NULL) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not create socket: %m\n"); return GNUNET_SYSERR; } memset (&addr, 0, sizeof (struct sockaddr_in6)); addr.sin6_family = AF_INET6; int err = GNUNET_NETWORK_socket_bind (dnsout6, (struct sockaddr *) &addr, sizeof (struct sockaddr_in6)); if (err != GNUNET_OK) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not bind a port: %m\n"); return GNUNET_SYSERR; } GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout6, &read_response6, NULL); return GNUNET_YES; } static int open_port () { struct sockaddr_in addr; dnsout = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0); if (dnsout == NULL) return GNUNET_SYSERR; memset (&addr, 0, sizeof (struct sockaddr_in)); addr.sin_family = AF_INET; int err = GNUNET_NETWORK_socket_bind (dnsout, (struct sockaddr *) &addr, sizeof (struct sockaddr_in)); if (err != GNUNET_OK) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "Could not bind a port: %m\n"); return GNUNET_SYSERR; } /* Read the port we bound to */ socklen_t addrlen = sizeof (struct sockaddr_in); err = getsockname (GNUNET_NETWORK_get_fd (dnsout), (struct sockaddr *) &addr, &addrlen); dnsoutport = htons (addr.sin_port); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Bound to port %d.\n", dnsoutport); GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout, &read_response, NULL); return GNUNET_YES; } void handle_response (struct dns_pkt *dns, struct sockaddr *addr, socklen_t addrlen, int r); /** * Read a response-packet of the UDP-Socket */ static void read_response6 (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct sockaddr_in6 addr; socklen_t addrlen = sizeof (addr); int r; int len; if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) return; memset (&addr, 0, sizeof addr); #ifndef MINGW if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout6), FIONREAD, &len)) { (void) open_port6 (); return; } #else /* port the code above? */ len = 65536; #endif unsigned char buf[len]; struct dns_pkt *dns = (struct dns_pkt *) buf; r = GNUNET_NETWORK_socket_recvfrom (dnsout, buf, sizeof (buf), (struct sockaddr *) &addr, &addrlen); if (r < 0) { (void) open_port6 (); return; } struct sockaddr *addr_ = GNUNET_malloc (sizeof addr); memcpy (addr_, &addr, sizeof addr); handle_response (dns, addr_, 4, r); GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout6, &read_response6, NULL); } /** * Read a response-packet of the UDP-Socket */ static void read_response (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { struct sockaddr_in addr; socklen_t addrlen = sizeof (addr); int r; int len; if (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN) return; memset (&addr, 0, sizeof addr); #ifndef MINGW if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len)) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "ioctl"); unhijack (dnsoutport); if (GNUNET_YES == open_port ()) GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &hijack, NULL); return; } #else /* port the code above? */ len = 65536; #endif unsigned char buf[len]; struct dns_pkt *dns = (struct dns_pkt *) buf; r = GNUNET_NETWORK_socket_recvfrom (dnsout, buf, sizeof (buf), (struct sockaddr *) &addr, &addrlen); if (r < 0) { GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "recvfrom"); unhijack (dnsoutport); if (GNUNET_YES == open_port ()) GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &hijack, NULL); return; } struct sockaddr *addr_ = GNUNET_malloc (sizeof addr); memcpy (addr_, &addr, sizeof addr); handle_response (dns, addr_, 4, r); GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, dnsout, &read_response, NULL); } void handle_response (struct dns_pkt *dns, struct sockaddr *addr, socklen_t addrlen, int r) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d\n", ntohs (dns->s.id)); if (query_states[dns->s.id].valid == GNUNET_YES) { if (query_states[dns->s.id].tunnel != NULL) { GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Answer to query %d for a remote peer!\n", ntohs (dns->s.id)); /* This response should go through a tunnel */ uint32_t *c = GNUNET_malloc (4 + sizeof (struct GNUNET_MESH_Tunnel *) + r); *c = r; struct GNUNET_MESH_Tunnel **t = (struct GNUNET_MESH_Tunnel **) (c + 1); *t = query_states[dns->s.id].tunnel; memcpy (t + 1, dns, r); struct tunnel_state *s = GNUNET_MESH_tunnel_get_data (query_states[dns->s.id].tunnel); if (NULL == s->th) { s->th = GNUNET_MESH_notify_transmit_ready (query_states[dns->s.id].tunnel, GNUNET_YES, 32, GNUNET_TIME_UNIT_MINUTES, NULL, r + sizeof (struct GNUNET_MessageHeader), mesh_send_response, c); } else { struct tunnel_notify_queue *element = GNUNET_malloc (sizeof (struct tunnel_notify_queue)); element->cls = c; element->len = r + sizeof (struct GNUNET_MessageHeader); element->cb = mesh_send_response; GNUNET_CONTAINER_DLL_insert_tail (s->head, s->tail, element); } } else { query_states[dns->s.id].valid = GNUNET_NO; size_t len = sizeof (struct answer_packet) + r - 1; /* 1 for the unsigned char data[1]; */ struct answer_packet_list *answer = GNUNET_malloc (len + sizeof (struct answer_packet_list) - (sizeof (struct answer_packet))); answer->pkt.hdr.type = htons (GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_RESPONSE_DNS); answer->pkt.hdr.size = htons (len); answer->pkt.subtype = GNUNET_DNS_ANSWER_TYPE_IP; answer->pkt.addrlen = addrlen; if (addrlen == 16) { struct sockaddr_in6 *addr_ = (struct sockaddr_in6 *) addr; memcpy (answer->pkt.from, &addr_->sin6_addr, addrlen); memcpy (answer->pkt.to, query_states[dns->s.id].local_ip, addrlen); } else if (addrlen == 4) { struct sockaddr_in *addr_ = (struct sockaddr_in *) addr; memcpy (answer->pkt.from, &addr_->sin_addr.s_addr, addrlen); memcpy (answer->pkt.to, query_states[dns->s.id].local_ip, addrlen); } else { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "addrlen = %d\n", addrlen); GNUNET_assert (0); } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "sending answer with addrlen = %d\n", addrlen); answer->pkt.dst_port = query_states[dns->s.id].local_port; memcpy (answer->pkt.data, dns, r); answer->client = query_states[dns->s.id].client; GNUNET_CONTAINER_DLL_insert_after (head, tail, tail, answer); if (server_notify == NULL) server_notify = GNUNET_SERVER_notify_transmit_ready (query_states[dns->s.id].client, len, GNUNET_TIME_UNIT_FOREVER_REL, &send_answer, NULL); } } GNUNET_free (addr); } /** * Task run during shutdown. * * @param cls unused * @param tc unused */ static void cleanup_task (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { GNUNET_assert (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)); unhijack (dnsoutport); GNUNET_DHT_disconnect (dht); GNUNET_MESH_disconnect (mesh_handle); } /** * @brief Create a port-map from udp and tcp redirects * * @param udp_redirects * @param tcp_redirects * * @return */ static uint64_t get_port_from_redirects (const char *udp_redirects, const char *tcp_redirects) { uint64_t ret = 0; char *cpy, *hostname, *redirect; int local_port; unsigned int count = 0; cpy = NULL; if (NULL != udp_redirects) { cpy = GNUNET_strdup (udp_redirects); for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " ")) { if (NULL == (hostname = strstr (redirect, ":"))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect); continue; } hostname[0] = '\0'; local_port = atoi (redirect); if (!((local_port > 0) && (local_port < 65536))) GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect); ret |= (0xFFFF & htons (local_port)); ret <<= 16; count++; if (count > 4) { ret = 0; goto out; } } GNUNET_free (cpy); cpy = NULL; } if (NULL != tcp_redirects) { cpy = GNUNET_strdup (tcp_redirects); for (redirect = strtok (cpy, " "); redirect != NULL; redirect = strtok (NULL, " ")) { if (NULL == (hostname = strstr (redirect, ":"))) { GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: option %s is not formatted correctly!\n", redirect); continue; } hostname[0] = '\0'; local_port = atoi (redirect); if (!((local_port > 0) && (local_port < 65536))) GNUNET_log (GNUNET_ERROR_TYPE_WARNING, "Warning: %s is not a correct port.", redirect); ret |= (0xFFFF & htons (local_port)); ret <<= 16; count++; if (count > 4) { ret = 0; goto out; } } GNUNET_free (cpy); cpy = NULL; } out: GNUNET_free_non_null (cpy); return ret; } static void publish_name (const char *name, uint64_t ports, uint32_t service_type, struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key) { size_t size = sizeof (struct GNUNET_DNS_Record); struct GNUNET_DNS_Record data; memset (&data, 0, size); data.purpose.size = htonl (size - sizeof (struct GNUNET_CRYPTO_RsaSignature)); data.purpose.purpose = GNUNET_SIGNATURE_PURPOSE_DNS_RECORD; GNUNET_CRYPTO_hash (name, strlen (name) + 1, &data.service_descriptor); GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Store with key1 %x\n", *((unsigned long long *) &data.service_descriptor)); data.service_type = service_type; data.ports = ports; GNUNET_CRYPTO_rsa_key_get_public (my_private_key, &data.peer); data.expiration_time = GNUNET_TIME_absolute_hton (GNUNET_TIME_relative_to_absolute (GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 2))); /* Sign the block */ if (GNUNET_OK != GNUNET_CRYPTO_rsa_sign (my_private_key, &data.purpose, &data.signature)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not sign DNS_Record\n"); return; } GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Putting with key %08x, size = %d\n", *((unsigned int *) &data.service_descriptor), size); GNUNET_DHT_put (dht, &data.service_descriptor, 5 /* DEFAULT_PUT_REPLICATION */ , GNUNET_DHT_RO_NONE, GNUNET_BLOCK_TYPE_DNS, size, (char *) &data, GNUNET_TIME_relative_to_absolute (GNUNET_TIME_UNIT_HOURS), GNUNET_TIME_UNIT_MINUTES, NULL, NULL); } /** * @brief Publishes the record defined by the section section * * @param cls closure * @param section the current section */ static void publish_iterate (void *cls GNUNET_UNUSED, const char *section) { char *udp_redirects; char *tcp_redirects; char *alternative_names; char *alternative_name; char *keyfile; if ((strlen (section) < 8) || (0 != strcmp (".gnunet.", section + (strlen (section) - 8)))) return; GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Parsing dns-name %s\n", section); if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (cfg, section, "UDP_REDIRECTS", &udp_redirects)) udp_redirects = NULL; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_string (cfg, section, "TCP_REDIRECTS", &tcp_redirects)) tcp_redirects = NULL; if (GNUNET_OK != GNUNET_CONFIGURATION_get_value_filename (cfg, "GNUNETD", "HOSTKEY", &keyfile)) { GNUNET_log (GNUNET_ERROR_TYPE_ERROR, "could not read keyfile-value\n"); if (keyfile != NULL) GNUNET_free (keyfile); return; } struct GNUNET_CRYPTO_RsaPrivateKey *my_private_key = GNUNET_CRYPTO_rsa_key_create_from_file (keyfile); GNUNET_free (keyfile); GNUNET_assert (my_private_key != NULL); uint64_t ports = get_port_from_redirects (udp_redirects, tcp_redirects); uint32_t service_type = 0; if (NULL != udp_redirects) service_type = GNUNET_DNS_SERVICE_TYPE_UDP; if (NULL != tcp_redirects) service_type |= GNUNET_DNS_SERVICE_TYPE_TCP; service_type = htonl (service_type); publish_name (section, ports, service_type, my_private_key); if (GNUNET_OK == GNUNET_CONFIGURATION_get_value_string (cfg, section, "ALTERNATIVE_NAMES", &alternative_names)) { for (alternative_name = strtok (alternative_names, " "); alternative_name != NULL; alternative_name = strtok (NULL, " ")) { char *altname = alloca (strlen (alternative_name) + strlen (section) + 1 + 1); strcpy (altname, alternative_name); strcpy (altname + strlen (alternative_name) + 1, section); altname[strlen (alternative_name)] = '.'; publish_name (altname, ports, service_type, my_private_key); } GNUNET_free (alternative_names); } GNUNET_CRYPTO_rsa_key_free (my_private_key); GNUNET_free_non_null (udp_redirects); GNUNET_free_non_null (tcp_redirects); } /** * Publish a DNS-record in the DHT. */ static void publish_names (void *cls GNUNET_UNUSED, const struct GNUNET_SCHEDULER_TaskContext *tc) { if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) return; GNUNET_CONFIGURATION_iterate_sections (cfg, &publish_iterate, NULL); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_HOURS, &publish_names, NULL); } /** * @param cls closure * @param server the initialized server * @param cfg_ configuration to use */ static void run (void *cls, struct GNUNET_SERVER_Handle *server, const struct GNUNET_CONFIGURATION_Handle *cfg_) { static const struct GNUNET_SERVER_MessageHandler handlers[] = { /* callback, cls, type, size */ {&receive_query, NULL, GNUNET_MESSAGE_TYPE_VPN_DNS_LOCAL_QUERY_DNS, 0}, {&rehijack, NULL, GNUNET_MESSAGE_TYPE_REHIJACK, sizeof (struct GNUNET_MessageHeader)}, {NULL, NULL, 0, 0} }; static const struct GNUNET_MESH_MessageHandler mesh_handlers[] = { {receive_mesh_query, GNUNET_MESSAGE_TYPE_VPN_REMOTE_QUERY_DNS, 0}, {receive_mesh_answer, GNUNET_MESSAGE_TYPE_VPN_REMOTE_ANSWER_DNS, 0}, {NULL, 0, 0} }; static GNUNET_MESH_ApplicationType apptypes[] = { GNUNET_APPLICATION_TYPE_END, GNUNET_APPLICATION_TYPE_END }; if (GNUNET_YES != open_port6 ()) { GNUNET_SCHEDULER_shutdown (); return; } if (GNUNET_YES != open_port ()) { GNUNET_SCHEDULER_shutdown (); return; } if (GNUNET_YES == GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT")) apptypes[0] = GNUNET_APPLICATION_TYPE_INTERNET_RESOLVER; mesh_handle = GNUNET_MESH_connect (cfg_, 42, NULL, new_tunnel, clean_tunnel, mesh_handlers, apptypes); cfg = cfg_; dht = GNUNET_DHT_connect (cfg, 1024); GNUNET_SCHEDULER_add_now (publish_names, NULL); GNUNET_SERVER_add_handlers (server, handlers); GNUNET_SERVER_disconnect_notify (server, &client_disconnect, NULL); GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup_task, cls); } /** * The main function for the dns service. * * @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) { return (GNUNET_OK == GNUNET_SERVICE_run (argc, argv, "dns", GNUNET_SERVICE_OPTION_NONE, &run, NULL)) ? 0 : 1; }