X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=src%2Fgns%2Fgnunet-dns2gns.c;h=e6e53d40524b4ce8810336af39e238ba421164d3;hb=e54f88a363b8560f83b13875c6e450b5393b0a7b;hp=a33020f161454e47fbb49ff5daf9e797d93f024d;hpb=d74e995ee32c4c37ca104b7ce3b0b1ee84306d22;p=oweals%2Fgnunet.git diff --git a/src/gns/gnunet-dns2gns.c b/src/gns/gnunet-dns2gns.c index a33020f16..e6e53d405 100644 --- a/src/gns/gnunet-dns2gns.c +++ b/src/gns/gnunet-dns2gns.c @@ -1,21 +1,19 @@ /* This file is part of GNUnet. - (C) 2012 Christian Grothoff (and other contributing authors) + Copyright (C) 2012-2013 GNUnet e.V. - GNUnet is free software; you can redistribute it and/or modify - it under the terms of the GNU General Public License as published - by the Free Software Foundation; either version 3, or (at your - option) any later version. + GNUnet is free software: you can redistribute it and/or modify it + under the terms of the GNU Affero General Public License as published + by the Free Software Foundation, either version 3 of the License, + or (at your option) any later version. GNUnet is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - 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. + Affero General Public License for more details. + + You should have received a copy of the GNU Affero General Public License + along with this program. If not, see . */ /** * @file gnunet-dns2gns.c @@ -24,33 +22,542 @@ */ #include "platform.h" #include -#include +#include +#include +#include +#include "gns.h" + +/** + * Timeout for DNS requests. + */ +#define TIMEOUT GNUNET_TIME_UNIT_MINUTES /** * Data kept per request. */ struct Request { + /** + * Socket to use for sending the reply. + */ + struct GNUNET_NETWORK_Handle *lsock; + + /** + * Destination address to use. + */ + const void *addr; + + /** + * Initially, this is the DNS request, it will then be + * converted to the DNS response. + */ + struct GNUNET_DNSPARSER_Packet *packet; + + /** + * Our GNS request handle. + */ + struct GNUNET_GNS_LookupWithTldRequest *lookup; + /** + * Our DNS request handle + */ + struct GNUNET_DNSSTUB_RequestSocket *dns_lookup; + + /** + * Task run on timeout or shutdown to clean up without + * response. + */ + struct GNUNET_SCHEDULER_Task *timeout_task; + + /** + * Original UDP request message. + */ + char *udp_msg; + + /** + * Number of bytes in @e addr. + */ + size_t addr_len; + + /** + * Number of bytes in @e udp_msg. + */ + size_t udp_msg_size; + + /** + * ID of the original request. + */ + uint16_t original_request_id; }; /** - * Listen socket. + * Handle to GNS resolver. */ -static struct GNUNET_NETWORK_Handle *listen_socket; +struct GNUNET_GNS_Handle *gns; + +/** + * Stub resolver + */ +struct GNUNET_DNSSTUB_Context *dns_stub; + +/** + * Listen socket for IPv4. + */ +static struct GNUNET_NETWORK_Handle *listen_socket4; + +/** + * Listen socket for IPv6. + */ +static struct GNUNET_NETWORK_Handle *listen_socket6; + +/** + * Task for IPv4 socket. + */ +static struct GNUNET_SCHEDULER_Task *t4; + +/** + * Task for IPv6 socket. + */ +static struct GNUNET_SCHEDULER_Task *t6; + +/** + * IP of DNS server + */ +static char *dns_ip; + +/** + * UDP Port we listen on for inbound DNS requests. + */ +static unsigned int listen_port = 53; + +/** + * Configuration to use. + */ +static const struct GNUNET_CONFIGURATION_Handle *cfg; /** * Task run on shutdown. Cleans up everything. * * @param cls unused - * @param tc scheduler context */ static void -do_shutdown (void *cls, - const struct GNUNET_SCHEDULER_TaskContext *tc) +do_shutdown (void *cls) +{ + (void) cls; + if (NULL != t4) + { + GNUNET_SCHEDULER_cancel (t4); + t4 = NULL; + } + if (NULL != t6) + { + GNUNET_SCHEDULER_cancel (t6); + t6 = NULL; + } + if (NULL != listen_socket4) + { + GNUNET_NETWORK_socket_close (listen_socket4); + listen_socket4 = NULL; + } + if (NULL != listen_socket6) + { + GNUNET_NETWORK_socket_close (listen_socket6); + listen_socket6 = NULL; + } + if (NULL != gns) + { + GNUNET_GNS_disconnect (gns); + gns = NULL; + } + if (NULL != dns_stub) + { + GNUNET_DNSSTUB_stop (dns_stub); + dns_stub = NULL; + } +} + + +/** + * Send the response for the given request and clean up. + * + * @param request context for the request. + */ +static void +send_response (struct Request *request) +{ + char *buf; + size_t size; + ssize_t sret; + + if (GNUNET_SYSERR == + GNUNET_DNSPARSER_pack (request->packet, + UINT16_MAX /* is this not too much? */, + &buf, + &size)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Failed to pack DNS response into UDP packet!\n")); + } + else + { + sret = GNUNET_NETWORK_socket_sendto (request->lsock, + buf, + size, + request->addr, + request->addr_len); + if ( (sret < 0) || + (size != (size_t) sret) ) + GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, + "sendto"); + GNUNET_free (buf); + } + GNUNET_SCHEDULER_cancel (request->timeout_task); + GNUNET_DNSPARSER_free_packet (request->packet); + GNUNET_free (request->udp_msg); + GNUNET_free (request); +} + + +/** + * Task run on timeout. Cleans up request. + * + * @param cls `struct Request *` of the request to clean up + */ +static void +do_timeout (void *cls) { + struct Request *request = cls; + + if (NULL != request->packet) + GNUNET_DNSPARSER_free_packet (request->packet); + if (NULL != request->lookup) + GNUNET_GNS_lookup_with_tld_cancel (request->lookup); + if (NULL != request->dns_lookup) + GNUNET_DNSSTUB_resolve_cancel (request->dns_lookup); + GNUNET_free (request->udp_msg); + GNUNET_free (request); +} + + +/** + * Iterator called on obtained result for a DNS lookup + * + * @param cls closure + * @param dns the DNS udp payload + * @param r size of the DNS payload + */ +static void +dns_result_processor (void *cls, + const struct GNUNET_TUN_DnsHeader *dns, + size_t r) +{ + struct Request *request = cls; + + if (NULL == dns) + { + /* DNSSTUB gave up, so we trigger timeout early */ + GNUNET_SCHEDULER_cancel (request->timeout_task); + do_timeout (request); + return; + } + if (request->original_request_id != dns->id) + { + /* for a another query, ignore */ + return; + } + request->packet = GNUNET_DNSPARSER_parse ((char*)dns, + r); + send_response (request); +} + + +/** + * Iterator called on obtained result for a GNS lookup. + * + * @param cls closure + * @param was_gns #GNUNET_NO if the TLD is not configured for GNS + * @param rd_count number of records in @a rd + * @param rd the records in reply + */ +static void +result_processor (void *cls, + int was_gns, + uint32_t rd_count, + const struct GNUNET_GNSRECORD_Data *rd) +{ + struct Request *request = cls; + struct GNUNET_DNSPARSER_Packet *packet; + struct GNUNET_DNSPARSER_Record rec; + + request->lookup = NULL; + if (GNUNET_NO == was_gns) + { + /* TLD not configured for GNS, fall back to DNS */ + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Using DNS resolver IP `%s' to resolve `%s'\n", + dns_ip, + request->packet->queries[0].name); + request->original_request_id = request->packet->id; + GNUNET_DNSPARSER_free_packet (request->packet); + request->packet = NULL; + request->dns_lookup = GNUNET_DNSSTUB_resolve (dns_stub, + request->udp_msg, + request->udp_msg_size, + &dns_result_processor, + request); + return; + } + packet = request->packet; + packet->flags.query_or_response = 1; + packet->flags.return_code = GNUNET_TUN_DNS_RETURN_CODE_NO_ERROR; + packet->flags.checking_disabled = 0; + packet->flags.authenticated_data = 1; + packet->flags.zero = 0; + packet->flags.recursion_available = 1; + packet->flags.message_truncated = 0; + packet->flags.authoritative_answer = 0; + //packet->flags.opcode = GNUNET_TUN_DNS_OPCODE_STATUS; // ??? + for (uint32_t i=0;iqueries[0].name); + rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; + rec.type = GNUNET_DNSPARSER_TYPE_A; + rec.data.raw.data = GNUNET_new (struct in_addr); + GNUNET_memcpy (rec.data.raw.data, + rd[i].data, + rd[i].data_size); + rec.data.raw.data_len = sizeof (struct in_addr); + GNUNET_array_append (packet->answers, + packet->num_answers, + rec); + break; + case GNUNET_DNSPARSER_TYPE_AAAA: + GNUNET_assert (sizeof (struct in6_addr) == rd[i].data_size); + rec.name = GNUNET_strdup (packet->queries[0].name); + rec.data.raw.data = GNUNET_new (struct in6_addr); + rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; + rec.type = GNUNET_DNSPARSER_TYPE_AAAA; + GNUNET_memcpy (rec.data.raw.data, + rd[i].data, + rd[i].data_size); + rec.data.raw.data_len = sizeof (struct in6_addr); + GNUNET_array_append (packet->answers, + packet->num_answers, + rec); + break; + case GNUNET_DNSPARSER_TYPE_CNAME: + rec.name = GNUNET_strdup (packet->queries[0].name); + rec.data.hostname = GNUNET_strdup (rd[i].data); + rec.dns_traffic_class = GNUNET_TUN_DNS_CLASS_INTERNET; + rec.type = GNUNET_DNSPARSER_TYPE_CNAME; + GNUNET_memcpy (rec.data.hostname, + rd[i].data, + rd[i].data_size); + GNUNET_array_append (packet->answers, + packet->num_answers, + rec); + break; + default: + /* skip */ + break; + } + } + send_response (request); +} + + +/** + * Handle DNS request. + * + * @param lsock socket to use for sending the reply + * @param addr address to use for sending the reply + * @param addr_len number of bytes in @a addr + * @param udp_msg DNS request payload + * @param udp_msg_size number of bytes in @a udp_msg + */ +static void +handle_request (struct GNUNET_NETWORK_Handle *lsock, + const void *addr, + size_t addr_len, + const char *udp_msg, + size_t udp_msg_size) +{ + struct Request *request; + struct GNUNET_DNSPARSER_Packet *packet; + + packet = GNUNET_DNSPARSER_parse (udp_msg, + udp_msg_size); + if (NULL == packet) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Cannot parse DNS request from %s\n"), + GNUNET_a2s (addr, addr_len)); + return; + } + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Received request for `%s' with flags %u, #answers %d, #auth %d, #additional %d\n", + packet->queries[0].name, + (unsigned int) packet->flags.query_or_response, + (int) packet->num_answers, + (int) packet->num_authority_records, + (int) packet->num_additional_records); + if ( (0 != packet->flags.query_or_response) || + (0 != packet->num_answers) || + (0 != packet->num_authority_records)) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Received malformed DNS request from %s\n"), + GNUNET_a2s (addr, addr_len)); + GNUNET_DNSPARSER_free_packet (packet); + return; + } + if ( (1 != packet->num_queries) ) + { + GNUNET_log (GNUNET_ERROR_TYPE_WARNING, + _("Received unsupported DNS request from %s\n"), + GNUNET_a2s (addr, + addr_len)); + GNUNET_DNSPARSER_free_packet (packet); + return; + } + request = GNUNET_malloc (sizeof (struct Request) + addr_len); + request->lsock = lsock; + request->packet = packet; + request->addr = &request[1]; + request->addr_len = addr_len; + GNUNET_memcpy (&request[1], + addr, + addr_len); + request->udp_msg_size = udp_msg_size; + request->udp_msg = GNUNET_memdup (udp_msg, + udp_msg_size); + request->timeout_task = GNUNET_SCHEDULER_add_delayed (TIMEOUT, + &do_timeout, + request); + GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, + "Calling GNS on `%s'\n", + packet->queries[0].name); + request->lookup = GNUNET_GNS_lookup_with_tld (gns, + packet->queries[0].name, + packet->queries[0].type, + GNUNET_NO, + &result_processor, + request); +} + + +/** + * Task to read IPv4 DNS packets. + * + * @param cls the 'listen_socket4' + */ +static void +read_dns4 (void *cls) +{ + struct sockaddr_in v4; + socklen_t addrlen; + ssize_t size; + const struct GNUNET_SCHEDULER_TaskContext *tc; + + GNUNET_assert (listen_socket4 == cls); + t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, + listen_socket4, + &read_dns4, + listen_socket4); + tc = GNUNET_SCHEDULER_get_task_context (); + if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason)) + return; /* shutdown? */ + size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket4); + if (0 > size) + { + GNUNET_break (0); + return; /* read error!? */ + } + { + char buf[size + 1]; + ssize_t sret; + + addrlen = sizeof (v4); + sret = GNUNET_NETWORK_socket_recvfrom (listen_socket4, + buf, + size + 1, + (struct sockaddr *) &v4, + &addrlen); + if (0 > sret) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, + "recvfrom"); + return; + } + GNUNET_break (size == sret); + handle_request (listen_socket4, + &v4, + addrlen, + buf, + size); + } +} + + +/** + * Task to read IPv6 DNS packets. + * + * @param cls the 'listen_socket6' + */ +static void +read_dns6 (void *cls) +{ + struct sockaddr_in6 v6; + socklen_t addrlen; + ssize_t size; + const struct GNUNET_SCHEDULER_TaskContext *tc; + + GNUNET_assert (listen_socket6 == cls); + t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, + listen_socket6, + &read_dns6, + listen_socket6); + tc = GNUNET_SCHEDULER_get_task_context (); + if (0 == (GNUNET_SCHEDULER_REASON_READ_READY & tc->reason)) + return; /* shutdown? */ + size = GNUNET_NETWORK_socket_recvfrom_amount (listen_socket6); + if (0 > size) + { + GNUNET_break (0); + return; /* read error!? */ + } + { + char buf[size]; + ssize_t sret; + + addrlen = sizeof (v6); + sret = GNUNET_NETWORK_socket_recvfrom (listen_socket6, + buf, + size, + (struct sockaddr *) &v6, + &addrlen); + if (0 > sret) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, + "recvfrom"); + return; + } + GNUNET_break (size == sret); + handle_request (listen_socket6, + &v6, + addrlen, + buf, + size); + } } @@ -60,44 +567,147 @@ do_shutdown (void *cls, * @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 + * @param c configuration */ static void -run (void *cls, char *const *args, const char *cfgfile, - const struct GNUNET_CONFIGURATION_Handle *cfg) +run (void *cls, + char *const *args, + const char *cfgfile, + const struct GNUNET_CONFIGURATION_Handle *c) { - GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, - &do_shutdown, NULL); + (void) cls; + (void) args; + (void) cfgfile; + cfg = c; + if (NULL == dns_ip) + { + GNUNET_log (GNUNET_ERROR_TYPE_ERROR, + _("No DNS server specified!\n")); + return; + } + GNUNET_SCHEDULER_add_shutdown (&do_shutdown, + NULL); + if (NULL == (gns = GNUNET_GNS_connect (cfg))) + return; + GNUNET_assert (NULL != (dns_stub = GNUNET_DNSSTUB_start (128))); + if (GNUNET_OK != + GNUNET_DNSSTUB_add_dns_ip (dns_stub, + dns_ip)) + { + GNUNET_DNSSTUB_stop (dns_stub); + GNUNET_GNS_disconnect (gns); + gns = NULL; + return; + } + listen_socket4 = GNUNET_NETWORK_socket_create (PF_INET, + SOCK_DGRAM, + IPPROTO_UDP); + if (NULL != listen_socket4) + { + struct sockaddr_in v4; + + memset (&v4, 0, sizeof (v4)); + v4.sin_family = AF_INET; +#if HAVE_SOCKADDR_IN_SIN_LEN + v4.sin_len = sizeof (v4); +#endif + v4.sin_port = htons (listen_port); + if (GNUNET_OK != + GNUNET_NETWORK_socket_bind (listen_socket4, + (struct sockaddr *) &v4, + sizeof (v4))) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind"); + GNUNET_NETWORK_socket_close (listen_socket4); + listen_socket4 = NULL; + } + } + listen_socket6 = GNUNET_NETWORK_socket_create (PF_INET6, + SOCK_DGRAM, + IPPROTO_UDP); + if (NULL != listen_socket6) + { + struct sockaddr_in6 v6; + + memset (&v6, 0, sizeof (v6)); + v6.sin6_family = AF_INET6; +#if HAVE_SOCKADDR_IN_SIN_LEN + v6.sin6_len = sizeof (v6); +#endif + v6.sin6_port = htons (listen_port); + if (GNUNET_OK != + GNUNET_NETWORK_socket_bind (listen_socket6, + (struct sockaddr *) &v6, + sizeof (v6))) + { + GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "bind"); + GNUNET_NETWORK_socket_close (listen_socket6); + listen_socket6 = NULL; + } + } + if ( (NULL == listen_socket4) && + (NULL == listen_socket6) ) + { + GNUNET_GNS_disconnect (gns); + gns = NULL; + GNUNET_DNSSTUB_stop (dns_stub); + dns_stub = NULL; + return; + } + if (NULL != listen_socket4) + t4 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, + listen_socket4, + &read_dns4, + listen_socket4); + if (NULL != listen_socket6) + t6 = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, + listen_socket6, + &read_dns6, + listen_socket6); } /** - * The main function for the fcfs daemon. + * The main function for the dns2gns daemon. * * @param argc number of arguments from the command line * @param argv command line arguments * @return 0 ok, 1 on error */ int -main (int argc, +main (int argc, char *const *argv) { - static const struct GNUNET_GETOPT_CommandLineOption options[] = { + struct GNUNET_GETOPT_CommandLineOption options[] = { + GNUNET_GETOPT_option_string ('d', + "dns", + "IP", + gettext_noop ("IP of recursive DNS resolver to use (required)"), + &dns_ip), + GNUNET_GETOPT_option_uint ('p', + "port", + "UDPPORT", + gettext_noop ("UDP port to listen on for inbound DNS requests; default: 2853"), + &listen_port), GNUNET_GETOPT_OPTION_END }; int ret; - if (GNUNET_OK != GNUNET_STRINGS_get_utf8_args (argc, argv, - &argc, &argv)) + if (GNUNET_OK != + GNUNET_STRINGS_get_utf8_args (argc, argv, + &argc, &argv)) return 2; - GNUNET_log_setup ("gnunet-dns2gns", "WARNING", NULL); + GNUNET_log_setup ("gnunet-dns2gns", + "WARNING", + NULL); ret = (GNUNET_OK == - GNUNET_PROGRAM_run (argc, argv, "gnunet-dns2gns", - _("GNUnet DNS-to-GNS proxy (a DNS server)"), + GNUNET_PROGRAM_run (argc, argv, + "gnunet-dns2gns", + _("GNUnet DNS-to-GNS proxy (a DNS server)"), options, &run, NULL)) ? 0 : 1; - + GNUNET_free ((void*) argv); return ret; }