* @file dns/gnunet-service-dns.c
* @brief service to intercept and modify DNS queries (and replies) of this system
* @author Christian Grothoff
+ *
+ * For "secure" interaction with the legacy DNS system, we permit
+ * replies only to arrive within a 5s window (and they must match
+ * ports, IPs and request IDs). Furthermore, we let the OS pick a
+ * source port, opening up to 128 sockets per address family (IPv4 or
+ * IPv6). Those sockets are closed if they are not in use for 5s
+ * (which means they will be freshly randomized afterwards). For new
+ * requests, we pick a random slot in the array with 128 socket slots
+ * (and re-use an existing socket if the slot is still in use). Thus
+ * each request will be given one of 128 random source ports, and the
+ * 128 random source ports will also change "often" (less often if the
+ * system is very busy, each time if we are mostly idle). At the same
+ * time, the system will never use more than 256 UDP sockets.
*/
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_signatures.h"
#include "dns.h"
#include "gnunet_dns_service.h"
+#include "gnunet_dnsparser_lib.h"
#include "gnunet_mesh_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet_tun_lib.h"
+/**
+ * Timeout for an external (Internet-DNS) DNS resolution
+ */
+#define REQUEST_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
+
+/**
+ * How many DNS sockets do we open at most at the same time?
+ * (technical socket maximum is this number x2 for IPv4+IPv6)
+ */
+#define DNS_SOCKET_MAX 128
+
/**
* Phases each request goes through.
*/
};
+/**
+ * UDP socket we are using for sending DNS requests to the Internet.
+ */
+struct RequestSocket
+{
+
+ /**
+ * UDP socket we use for this request for IPv4
+ */
+ struct GNUNET_NETWORK_Handle *dnsout4;
+
+ /**
+ * UDP socket we use for this request for IPv6
+ */
+ struct GNUNET_NETWORK_Handle *dnsout6;
+
+ /**
+ * Task for reading from dnsout4 and dnsout6.
+ */
+ GNUNET_SCHEDULER_TaskIdentifier read_task;
+
+ /**
+ * When should this socket be closed?
+ */
+ struct GNUNET_TIME_Absolute timeout;
+};
+
+
/**
* Entry we keep for each active request.
*/
*/
char *payload;
+ /**
+ * Socket we are using to transmit this request (must match if we receive
+ * a response). Must NOT be freed as part of this request record (as it
+ * might be shared with other requests).
+ */
+ struct GNUNET_NETWORK_Handle *dnsout;
+
/**
* Source address of the original request (for sending response).
*/
*/
struct sockaddr_storage dst_addr;
+ /**
+ * When should this request time out?
+ */
+ struct GNUNET_TIME_Absolute timeout;
+
/**
* ID of this request, also basis for hashing. Lowest 16 bit will
* be our message ID when doing a global DNS request and our index
};
-
/**
* State we keep for each DNS tunnel that terminates at this node.
*/
*/
char *reply;
+ /**
+ * Socket we are using to transmit this request (must match if we receive
+ * a response). Must NOT be freed as part of this request record (as it
+ * might be shared with other requests).
+ */
+ struct GNUNET_NETWORK_Handle *dnsout;
+
/**
* Address we sent the DNS request to.
*/
struct sockaddr_storage addr;
+ /**
+ * When should this request time out?
+ */
+ struct GNUNET_TIME_Absolute timeout;
+
/**
* Number of bytes in 'addr'.
*/
/**
- * The IPv4 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 *dnsout4;
-
-/**
- * The IPv6 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 *dnsout6;
-
-/**
- * Task for reading from dnsout4.
- */
-static GNUNET_SCHEDULER_TaskIdentifier read4_task;
-
-/**
- * Task for reading from dnsout6.
- */
-static GNUNET_SCHEDULER_TaskIdentifier read6_task;
-
-/**
- * The port bound to the socket dnsout (and/or dnsout6). We always (try) to bind
- * both sockets to the same port.
+ * Global return value from 'main'.
*/
-static uint16_t dnsoutport;
+static int global_ret;
/**
* The configuration to use
/**
* Command-line arguments we are giving to the hijacker process.
*/
-static char *helper_argv[8];
+static char *helper_argv[7];
/**
* Head of DLL of clients we consult.
*/
static struct TunnelState *tunnels[UINT16_MAX + 1];
+/**
+ * Array of all open sockets for DNS requests.
+ */
+static struct RequestSocket sockets[DNS_SOCKET_MAX];
+
/**
* Generator for unique request IDs.
*/
static struct GNUNET_MESH_Handle *mesh;
+/**
+ * We're done with a RequestSocket, close it for now.
+ *
+ * @param rs request socket to clean up
+ */
+static void
+cleanup_rs (struct RequestSocket *rs)
+{
+ if (NULL != rs->dnsout4)
+ {
+ GNUNET_NETWORK_socket_close (rs->dnsout4);
+ rs->dnsout4 = NULL;
+ }
+ if (NULL != rs->dnsout6)
+ {
+ GNUNET_NETWORK_socket_close (rs->dnsout6);
+ rs->dnsout6 = NULL;
+ }
+ if (GNUNET_SCHEDULER_NO_TASK != rs->read_task)
+ {
+ GNUNET_SCHEDULER_cancel (rs->read_task);
+ rs->read_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+}
+
+
/**
* We're done processing a DNS request, free associated memory.
*
GNUNET_HELPER_stop (hijacker);
hijacker = NULL;
- for (i=0;i<8;i++)
+ for (i=0;i<7;i++)
GNUNET_free_non_null (helper_argv[i]);
- if (NULL != dnsout4)
- {
- GNUNET_NETWORK_socket_close (dnsout4);
- dnsout4 = NULL;
- }
- if (GNUNET_SCHEDULER_NO_TASK != read4_task)
- {
- GNUNET_SCHEDULER_cancel (read4_task);
- read4_task = GNUNET_SCHEDULER_NO_TASK;
- }
- if (NULL != dnsout6)
- {
- GNUNET_NETWORK_socket_close (dnsout6);
- dnsout6 = NULL;
- }
- if (GNUNET_SCHEDULER_NO_TASK != read6_task)
- {
- GNUNET_SCHEDULER_cancel (read6_task);
- read6_task = GNUNET_SCHEDULER_NO_TASK;
- }
- for (i=0;i<65536;i++)
+ for (i=0;i<=UINT16_MAX;i++)
cleanup_rr (&requests[i]);
GNUNET_SERVER_notification_context_destroy (nc);
nc = NULL;
if (stats != NULL)
{
- GNUNET_STATISTICS_destroy (stats, GNUNET_YES);
+ GNUNET_STATISTICS_destroy (stats, GNUNET_NO);
stats = NULL;
}
if (NULL != dns_exit)
GNUNET_free (dns_exit);
dns_exit = NULL;
}
+ if (NULL != mesh)
+ {
+ GNUNET_MESH_disconnect(mesh);
+ mesh = NULL;
+ }
+}
+
+
+/**
+ * Open source port for sending DNS requests
+ *
+ * @param af AF_INET or AF_INET6
+ * @return GNUNET_OK on success
+ */
+static struct GNUNET_NETWORK_Handle *
+open_socket (int af)
+{
+ struct sockaddr_in a4;
+ struct sockaddr_in6 a6;
+ struct sockaddr *sa;
+ socklen_t alen;
+ struct GNUNET_NETWORK_Handle *ret;
+
+ ret = GNUNET_NETWORK_socket_create (af, SOCK_DGRAM, 0);
+ if (NULL == ret)
+ return NULL;
+ switch (af)
+ {
+ case AF_INET:
+ memset (&a4, 0, alen = sizeof (struct sockaddr_in));
+ sa = (struct sockaddr *) &a4;
+ break;
+ case AF_INET6:
+ memset (&a6, 0, alen = sizeof (struct sockaddr_in6));
+ sa = (struct sockaddr *) &a6;
+ break;
+ default:
+ GNUNET_break (0);
+ GNUNET_NETWORK_socket_close (ret);
+ return NULL;
+ }
+ sa->sa_family = af;
+ if (GNUNET_OK != GNUNET_NETWORK_socket_bind (ret,
+ sa,
+ alen))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Could not bind to any port: %s\n"),
+ STRERROR (errno));
+ GNUNET_NETWORK_socket_close (ret);
+ return NULL;
+ }
+ return ret;
}
{
struct GNUNET_MessageHeader *hdr;
size_t reply_len;
- uint16_t spt;
- uint16_t dpt;
+ uint16_t source_port;
+ uint16_t destination_port;
GNUNET_array_grow (rr->client_wait_list,
rr->client_wait_list_length,
return;
}
{
- char buf[reply_len];
+ char buf[reply_len] GNUNET_ALIGN;
size_t off;
struct GNUNET_TUN_IPv4Header ip4;
struct GNUNET_TUN_IPv6Header ip6;
struct sockaddr_in *src = (struct sockaddr_in *) &rr->src_addr;
struct sockaddr_in *dst = (struct sockaddr_in *) &rr->dst_addr;
- spt = dst->sin_port;
- dpt = src->sin_port;
+ source_port = dst->sin_port;
+ destination_port = src->sin_port;
GNUNET_TUN_initialize_ipv4_header (&ip4,
IPPROTO_UDP,
reply_len - off - sizeof (struct GNUNET_TUN_IPv4Header),
struct sockaddr_in6 *src = (struct sockaddr_in6 *) &rr->src_addr;
struct sockaddr_in6 *dst = (struct sockaddr_in6 *) &rr->dst_addr;
- spt = dst->sin6_port;
- dpt = src->sin6_port;
+ source_port = dst->sin6_port;
+ destination_port = src->sin6_port;
GNUNET_TUN_initialize_ipv6_header (&ip6,
IPPROTO_UDP,
reply_len - sizeof (struct GNUNET_TUN_IPv6Header),
{
struct GNUNET_TUN_UdpHeader udp;
- udp.spt = spt;
- udp.dpt = dpt;
+ udp.source_port = source_port;
+ udp.destination_port = destination_port;
udp.len = htons (reply_len - off);
if (AF_INET == rr->src_addr.ss_family)
GNUNET_TUN_calculate_udp4_checksum (&ip4,
}
/* final checks & sending */
GNUNET_assert (off == reply_len);
- GNUNET_HELPER_send (hijacker,
- hdr,
- GNUNET_YES,
- NULL, NULL);
+ (void) GNUNET_HELPER_send (hijacker,
+ hdr,
+ GNUNET_YES,
+ NULL, NULL);
GNUNET_STATISTICS_update (stats,
gettext_noop ("# DNS requests answered via TUN interface"),
1, GNUNET_NO);
send_request_to_client (struct RequestRecord *rr,
struct GNUNET_SERVER_Client *client)
{
- char buf[sizeof (struct GNUNET_DNS_Request) + rr->payload_length];
+ char buf[sizeof (struct GNUNET_DNS_Request) + rr->payload_length] GNUNET_ALIGN;
struct GNUNET_DNS_Request *req;
if (sizeof (buf) >= GNUNET_SERVER_MAX_MESSAGE_SIZE)
}
+/**
+ * Read a DNS response from the (unhindered) UDP-Socket
+ *
+ * @param cls socket to read from
+ * @param tc scheduler context (must be shutdown or read ready)
+ */
+static void
+read_response (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc);
+
+
+/**
+ * Get a socket of the specified address family to send out a
+ * UDP DNS request to the Internet.
+ *
+ * @param af desired address family
+ * @return NULL on error (given AF not "supported")
+ */
+static struct GNUNET_NETWORK_Handle *
+get_request_socket (int af)
+{
+ struct RequestSocket *rs;
+ struct GNUNET_NETWORK_FDSet *rset;
+ static struct GNUNET_NETWORK_Handle *ret;
+
+ rs = &sockets[GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
+ DNS_SOCKET_MAX)];
+ rs->timeout = GNUNET_TIME_relative_to_absolute (REQUEST_TIMEOUT);
+ switch (af)
+ {
+ case AF_INET:
+ if (NULL == rs->dnsout4)
+ rs->dnsout4 = open_socket (AF_INET);
+ ret = rs->dnsout4;
+ break;
+ case AF_INET6:
+ if (NULL == rs->dnsout6)
+ rs->dnsout6 = open_socket (AF_INET6);
+ ret = rs->dnsout6;
+ break;
+ default:
+ return NULL;
+ }
+ if (GNUNET_SCHEDULER_NO_TASK != rs->read_task)
+ {
+ GNUNET_SCHEDULER_cancel (rs->read_task);
+ rs->read_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ if ( (NULL == rs->dnsout4) &&
+ (NULL == rs->dnsout6) )
+ return NULL;
+ rset = GNUNET_NETWORK_fdset_create ();
+ if (NULL != rs->dnsout4)
+ GNUNET_NETWORK_fdset_set (rset, rs->dnsout4);
+ if (NULL != rs->dnsout6)
+ GNUNET_NETWORK_fdset_set (rset, rs->dnsout6);
+ rs->read_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT,
+ REQUEST_TIMEOUT,
+ rset,
+ NULL,
+ &read_response, rs);
+ GNUNET_NETWORK_fdset_destroy (rset);
+ return ret;
+}
+
+
/**
* A client has completed its processing for this
* request. Move on.
struct ClientRecord *cr;
int nz;
unsigned int j;
- struct GNUNET_NETWORK_Handle *dnsout;
socklen_t salen;
if (rr->phase == RP_DROP)
next_phase (rr);
return;
case RP_QUERY:
- rr->phase = RP_INTERNET_DNS;
switch (rr->dst_addr.ss_family)
{
case AF_INET:
- dnsout = dnsout4;
- salen = sizeof (struct GNUNET_TUN_IPv4Header);
+ salen = sizeof (struct sockaddr_in);
break;
case AF_INET6:
- dnsout = dnsout6;
- salen = sizeof (struct GNUNET_TUN_IPv6Header);
+ salen = sizeof (struct sockaddr_in6);
break;
default:
- GNUNET_break (0);
- cleanup_rr (rr);
- return;
+ GNUNET_assert (0);
}
- if (NULL == dnsout)
+
+ rr->phase = RP_INTERNET_DNS;
+ rr->dnsout = get_request_socket (rr->dst_addr.ss_family);
+ if (NULL == rr->dnsout)
{
GNUNET_STATISTICS_update (stats,
- gettext_noop ("# DNS exit failed (address family not supported)"),
+ gettext_noop ("# DNS exit failed (failed to open socket)"),
1, GNUNET_NO);
cleanup_rr (rr);
return;
}
- GNUNET_NETWORK_socket_sendto (dnsout,
+ GNUNET_NETWORK_socket_sendto (rr->dnsout,
rr->payload,
rr->payload_length,
(struct sockaddr*) &rr->dst_addr,
salen);
+ rr->timeout = GNUNET_TIME_relative_to_absolute (REQUEST_TIMEOUT);
return;
case RP_INTERNET_DNS:
rr->phase = RP_MODIFY;
/**
- * Read a DNS response from the (unhindered) UDP-Socket
+ * Actually do the reading of a DNS packet from our UDP socket and see
+ * if we have a valid, matching, pending request.
*
- * @param cls socket to read from
- * @param tc scheduler context (must be shutdown or read ready)
+ * @param dnsout socket to read from
+ * @return GNUNET_OK on success, GNUNET_NO on drop, GNUNET_SYSERR on IO-errors (closed socket)
*/
-static void
-read_response (void *cls,
- const struct GNUNET_SCHEDULER_TaskContext *tc)
+static int
+do_dns_read (struct GNUNET_NETWORK_Handle *dnsout)
{
- struct GNUNET_NETWORK_Handle *dnsout = cls;
- struct sockaddr_in addr4;
- struct sockaddr_in6 addr6;
- struct sockaddr *addr;
- struct GNUNET_TUN_DnsHeader *dns;
+ struct sockaddr_storage addr;
socklen_t addrlen;
+ struct GNUNET_TUN_DnsHeader *dns;
struct RequestRecord *rr;
struct TunnelState *ts;
ssize_t r;
int len;
- if (dnsout == dnsout4)
- {
- addrlen = sizeof (struct sockaddr_in);
- addr = (struct sockaddr* ) &addr4;
- read4_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
- dnsout,
- &read_response,
- dnsout);
- }
- else
- {
- addrlen = sizeof (struct sockaddr_in6);
- addr = (struct sockaddr* ) &addr6;
- read6_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
- dnsout,
- &read_response,
- dnsout);
- }
- if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
- return;
-
#ifndef MINGW
if (0 != ioctl (GNUNET_NETWORK_get_fd (dnsout), FIONREAD, &len))
{
/* conservative choice: */
- len = 65536;
+ len = UINT16_MAX;
}
#else
/* port the code above? */
- len = 65536;
+ len = UINT16_MAX;
#endif
{
- unsigned char buf[len];
+ unsigned char buf[len] GNUNET_ALIGN;
- memset (addr, 0, addrlen);
+ addrlen = sizeof (addr);
+ memset (&addr, 0, sizeof (addr));
r = GNUNET_NETWORK_socket_recvfrom (dnsout,
buf, sizeof (buf),
- addr, &addrlen);
+ (struct sockaddr*) &addr, &addrlen);
if (-1 == r)
{
GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "recvfrom");
- return;
+ GNUNET_NETWORK_socket_close (dnsout);
+ return GNUNET_SYSERR;
}
if (sizeof (struct GNUNET_TUN_DnsHeader) > r)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Received DNS response that is too small (%u bytes)"),
r);
- return;
+ return GNUNET_NO;
}
dns = (struct GNUNET_TUN_DnsHeader *) buf;
/* Handle case that this is a reply to a request from a MESH DNS tunnel */
ts = tunnels[dns->id];
if ( (NULL == ts) ||
+ (ts->dnsout != dnsout) ||
(addrlen != ts->addrlen) ||
(0 != memcmp (&ts->addr,
- addr,
- addrlen)) )
+ &addr,
+ addrlen)) ||
+ (0 == GNUNET_TIME_absolute_get_remaining (ts->timeout).rel_value) )
ts = NULL; /* DNS responder address missmatch */
if (NULL != ts)
{
}
/* Handle case that this is a reply to a local request (intercepted from TUN interface) */
rr = &requests[dns->id];
- if (rr->phase != RP_INTERNET_DNS)
+ if ( (rr->phase != RP_INTERNET_DNS) ||
+ (rr->dnsout != dnsout) ||
+ (0 != memcmp (&rr->dst_addr,
+ &addr,
+ addrlen)) ||
+ (0 == GNUNET_TIME_absolute_get_remaining (rr->timeout).rel_value) )
{
if (NULL == ts)
{
gettext_noop ("# External DNS response discarded (no matching request)"),
1, GNUNET_NO);
}
- return;
+ return GNUNET_NO;
}
GNUNET_free_non_null (rr->payload);
rr->payload = GNUNET_malloc (r);
rr->payload_length = r;
next_phase (rr);
}
-}
-
-
-/**
- * Open source port for sending DNS request on IPv4.
- *
- * @return GNUNET_OK on success
- */
-static int
-open_port4 ()
-{
- struct sockaddr_in addr;
- socklen_t addrlen;
-
- dnsout4 = GNUNET_NETWORK_socket_create (AF_INET, SOCK_DGRAM, 0);
- if (dnsout4 == NULL)
- return GNUNET_SYSERR;
-
- memset (&addr, 0, sizeof (struct sockaddr_in));
- addr.sin_family = AF_INET;
- int err = GNUNET_NETWORK_socket_bind (dnsout4,
- (struct sockaddr *) &addr,
- sizeof (struct sockaddr_in));
-
- if (err != GNUNET_OK)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Could not bind to any port: %s\n"),
- STRERROR (errno));
- GNUNET_NETWORK_socket_close (dnsout4);
- dnsout4 = NULL;
- return GNUNET_SYSERR;
- }
-
- /* Read the port we bound to */
- addrlen = sizeof (struct sockaddr_in);
- if (0 != getsockname (GNUNET_NETWORK_get_fd (dnsout4),
- (struct sockaddr *) &addr,
- &addrlen))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Could not determine port I got: %s\n"),
- STRERROR (errno));
- GNUNET_NETWORK_socket_close (dnsout4);
- dnsout4 = NULL;
- return GNUNET_SYSERR;
- }
- dnsoutport = htons (addr.sin_port);
-
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("GNUnet DNS will exit on source port %u\n"),
- (unsigned int) dnsoutport);
- read4_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
- dnsout4,
- &read_response, dnsout4);
return GNUNET_OK;
}
/**
- * Open source port for sending DNS request on IPv6. Should be
- * called AFTER open_port4.
+ * Read a DNS response from the (unhindered) UDP-Socket
*
- * @return GNUNET_OK on success
- */
-static int
-open_port6 ()
+ * @param cls socket to read from
+ * @param tc scheduler context (must be shutdown or read ready)
+ */
+static void
+read_response (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
{
- struct sockaddr_in6 addr;
- socklen_t addrlen;
+ struct RequestSocket *rs = cls;
+ struct GNUNET_NETWORK_FDSet *rset;
- dnsout6 = GNUNET_NETWORK_socket_create (AF_INET6, SOCK_DGRAM, 0);
- if (dnsout6 == NULL)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Could not create IPv6 socket: %s\n"),
- STRERROR (errno));
- return GNUNET_SYSERR;
- }
- memset (&addr, 0, sizeof (struct sockaddr_in6));
- addr.sin6_family = AF_INET6;
- addr.sin6_port = htons (dnsoutport);
- 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 to port %u: %s\n"),
- (unsigned int) dnsoutport,
- STRERROR (errno));
- GNUNET_NETWORK_socket_close (dnsout6);
- dnsout6 = NULL;
- return GNUNET_SYSERR;
- }
- if (0 == dnsoutport)
+ rs->read_task = GNUNET_SCHEDULER_NO_TASK;
+ if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_READ_READY))
{
- addrlen = sizeof (struct sockaddr_in6);
- if (0 != getsockname (GNUNET_NETWORK_get_fd (dnsout6),
- (struct sockaddr *) &addr,
- &addrlen))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Could not determine port I got: %s\n"),
- STRERROR (errno));
- GNUNET_NETWORK_socket_close (dnsout6);
- dnsout6 = NULL;
- return GNUNET_SYSERR;
- }
+ /* timeout or shutdown */
+ cleanup_rs (rs);
+ return;
}
- dnsoutport = htons (addr.sin6_port);
- read6_task = GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
- dnsout6,
- &read_response, dnsout6);
- return GNUNET_YES;
+ /* read and process ready sockets */
+ if ((NULL != rs->dnsout4) &&
+ (GNUNET_NETWORK_fdset_isset (tc->read_ready, rs->dnsout4)) &&
+ (GNUNET_SYSERR == do_dns_read (rs->dnsout4)))
+ rs->dnsout4 = NULL;
+ if ((NULL != rs->dnsout6) &&
+ (GNUNET_NETWORK_fdset_isset (tc->read_ready, rs->dnsout6)) &&
+ (GNUNET_SYSERR == do_dns_read (rs->dnsout6)))
+ rs->dnsout6 = NULL;
+
+ /* re-schedule read task */
+ rset = GNUNET_NETWORK_fdset_create ();
+ if (NULL != rs->dnsout4)
+ GNUNET_NETWORK_fdset_set (rset, rs->dnsout4);
+ if (NULL != rs->dnsout6)
+ GNUNET_NETWORK_fdset_set (rset, rs->dnsout6);
+ rs->read_task = GNUNET_SCHEDULER_add_select (GNUNET_SCHEDULER_PRIORITY_DEFAULT,
+ GNUNET_TIME_absolute_get_remaining (rs->timeout),
+ rset,
+ NULL,
+ &read_response, rs);
+ GNUNET_NETWORK_fdset_destroy (rset);
}
return;
}
GNUNET_free_non_null (rr->payload);
-#if DEBUG_DNS
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Changing DNS reply according to client specifications\n"));
-#endif
+ "Changing DNS reply according to client specifications\n");
rr->payload = GNUNET_malloc (msize);
rr->payload_length = msize;
memcpy (rr->payload, &resp[1], msize);
rr->client_wait_list_length,
0);
}
+ /* if query changed to answer, move past DNS resolution phase... */
+ if ( (RP_QUERY == rr->phase) &&
+ (rr->payload_length > sizeof (struct GNUNET_TUN_DnsHeader)) &&
+ ((struct GNUNET_DNSPARSER_Flags*)&(((struct GNUNET_TUN_DnsHeader*) rr->payload)->flags))->query_or_response == 1)
+ {
+ rr->phase = RP_INTERNET_DNS;
+ GNUNET_array_grow (rr->client_wait_list,
+ rr->client_wait_list_length,
+ 0);
+ }
break;
}
next_phase (rr);
* @param client identification of the client
* @param message the actual message, a DNS request we should handle
*/
-static void
+static int
process_helper_messages (void *cls GNUNET_UNUSED, void *client,
const struct GNUNET_MessageHeader *message)
{
{
/* non-IP packet received on TUN!? */
GNUNET_break (0);
- return;
+ return GNUNET_OK;
}
msize -= sizeof (struct GNUNET_MessageHeader);
tun = (const struct GNUNET_TUN_Layer2PacketHeader *) &message[1];
{
case ETH_P_IPV4:
ip4 = (const struct GNUNET_TUN_IPv4Header *) &tun[1];
+ ip6 = NULL; /* make compiler happy */
if ( (msize < sizeof (struct GNUNET_TUN_IPv4Header)) ||
(ip4->version != 4) ||
(ip4->header_length != sizeof (struct GNUNET_TUN_IPv4Header) / 4) ||
/* non-IP/UDP packet received on TUN (or with options) */
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
_("Received malformed IPv4-UDP packet on TUN interface.\n"));
- return;
+ return GNUNET_OK;
}
udp = (const struct GNUNET_TUN_UdpHeader*) &ip4[1];
msize -= sizeof (struct GNUNET_TUN_IPv4Header);
break;
case ETH_P_IPV6:
+ ip4 = NULL; /* make compiler happy */
ip6 = (const struct GNUNET_TUN_IPv6Header *) &tun[1];
if ( (msize < sizeof (struct GNUNET_TUN_IPv6Header)) ||
(ip6->version != 6) ||
/* non-IP/UDP packet received on TUN (or with extensions) */
GNUNET_log (GNUNET_ERROR_TYPE_INFO,
_("Received malformed IPv6-UDP packet on TUN interface.\n"));
- return;
+ return GNUNET_OK;
}
udp = (const struct GNUNET_TUN_UdpHeader*) &ip6[1];
msize -= sizeof (struct GNUNET_TUN_IPv6Header);
_("Got non-IP packet with %u bytes and protocol %u from TUN\n"),
(unsigned int) msize,
ntohs (tun->proto));
- return;
+ return GNUNET_OK;
}
if (msize <= sizeof (struct GNUNET_TUN_UdpHeader) + sizeof (struct GNUNET_TUN_DnsHeader))
{
GNUNET_STATISTICS_update (stats,
gettext_noop ("# Non-DNS UDP packet received via TUN interface"),
1, GNUNET_NO);
- return;
+ return GNUNET_OK;
}
msize -= sizeof (struct GNUNET_TUN_UdpHeader);
dns = (const struct GNUNET_TUN_DnsHeader*) &udp[1];
dsta4->sin_family = AF_INET;
srca4->sin_addr = ip4->source_address;
dsta4->sin_addr = ip4->destination_address;
- srca4->sin_port = udp->spt;
- dsta4->sin_port = udp->dpt;
+ srca4->sin_port = udp->source_port;
+ dsta4->sin_port = udp->destination_port;
#if HAVE_SOCKADDR_IN_SIN_LEN
- srca4->sin_len = sizeof (sizeof (struct sockaddr_in));
- dsta4->sin_len = sizeof (sizeof (struct sockaddr_in));
+ srca4->sin_len = sizeof (struct sockaddr_in);
+ dsta4->sin_len = sizeof (struct sockaddr_in);
#endif
}
break;
dsta6->sin6_family = AF_INET6;
srca6->sin6_addr = ip6->source_address;
dsta6->sin6_addr = ip6->destination_address;
- srca6->sin6_port = udp->spt;
- dsta6->sin6_port = udp->dpt;
+ srca6->sin6_port = udp->source_port;
+ dsta6->sin6_port = udp->destination_port;
#if HAVE_SOCKADDR_IN_SIN_LEN
- srca6->sin6_len = sizeof (sizeof (struct sockaddr_in6));
- dsta6->sin6_len = sizeof (sizeof (struct sockaddr_in6));
+ srca6->sin6_len = sizeof (struct sockaddr_in6);
+ dsta6->sin6_len = sizeof (struct sockaddr_in6);
#endif
}
break;
1, GNUNET_NO);
/* start request processing state machine */
next_phase (rr);
+ return GNUNET_OK;
}
const struct GNUNET_TUN_DnsHeader *dns;
size_t mlen = ntohs (message->size);
size_t dlen = mlen - sizeof (struct GNUNET_MessageHeader);
- char buf[dlen];
+ char buf[dlen] GNUNET_ALIGN;
struct GNUNET_TUN_DnsHeader *dout;
struct sockaddr_in v4;
struct sockaddr_in6 v6;
struct sockaddr *so;
socklen_t salen;
- struct GNUNET_NETWORK_Handle *dnsout;
-
+
if (dlen < sizeof (struct GNUNET_TUN_DnsHeader))
{
GNUNET_break_op (0);
if (tunnels[ts->my_id] == ts)
tunnels[ts->my_id] = NULL;
ts->my_id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
- 65536);
+ UINT16_MAX + 1);
tunnels[ts->my_id] = ts;
memcpy (buf, dns, dlen);
dout = (struct GNUNET_TUN_DnsHeader*) buf;
dout->id = ts->my_id;
-
memset (&v4, 0, sizeof (v4));
memset (&v6, 0, sizeof (v6));
- dnsout = NULL;
if (1 == inet_pton (AF_INET, dns_exit, &v4.sin_addr))
{
salen = sizeof (v4);
v4.sin_len = (u_char) salen;
#endif
so = (struct sockaddr *) &v4;
- dnsout = dnsout4;
- }
- if (1 == inet_pton (AF_INET6, dns_exit, &v6.sin6_addr))
+ ts->dnsout = get_request_socket (AF_INET);
+ }
+ else if (1 == inet_pton (AF_INET6, dns_exit, &v6.sin6_addr))
{
salen = sizeof (v6);
v6.sin6_family = AF_INET6;
v6.sin6_len = (u_char) salen;
#endif
so = (struct sockaddr *) &v6;
- dnsout = dnsout6;
+ ts->dnsout = get_request_socket (AF_INET6);
+ }
+ else
+ {
+ GNUNET_break (0);
+ return GNUNET_SYSERR;
}
- if (NULL == dnsout)
+ if (NULL == ts->dnsout)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
_("Configured DNS exit `%s' is not working / valid.\n"),
so,
salen);
ts->addrlen = salen;
- GNUNET_NETWORK_socket_sendto (dnsout,
+ GNUNET_NETWORK_socket_sendto (ts->dnsout,
buf, dlen, so, salen);
+ ts->timeout = GNUNET_TIME_relative_to_absolute (REQUEST_TIMEOUT);
return GNUNET_OK;
}
* @param cls closure
* @param tunnel new handle to the tunnel
* @param initiator peer that started the tunnel
- * @param atsi performance information for the tunnel
+ * @param ats performance information for the tunnel
* @return initial tunnel context for the tunnel
*/
static void *
{&handle_client_response, NULL, GNUNET_MESSAGE_TYPE_DNS_CLIENT_RESPONSE, 0},
{NULL, NULL, 0, 0}
};
- char port_s[6];
char *ifc_name;
char *ipv4addr;
char *ipv4mask;
char *ipv6addr;
char *ipv6prefix;
+ struct in_addr dns_exit4;
+ struct in6_addr dns_exit6;
cfg = cfg_;
+ if (GNUNET_YES !=
+ GNUNET_OS_check_helper_binary ("gnunet-helper-dns"))
+ {
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("`%s' must be installed SUID, refusing to run\n"),
+ "gnunet-helper-dns");
+ global_ret = 1;
+ return;
+ }
+
stats = GNUNET_STATISTICS_create ("dns", cfg);
nc = GNUNET_SERVER_notification_context_create (server, 1);
GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL, &cleanup_task,
cls);
- (void) GNUNET_CONFIGURATION_get_value_string (cfg, "dns",
- "DNS_EXIT",
- &dns_exit);
- if (GNUNET_YES ==
- GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT"))
+ if ( (GNUNET_YES ==
+ GNUNET_CONFIGURATION_get_value_yesno (cfg_, "dns", "PROVIDE_EXIT")) &&
+ ( (GNUNET_OK !=
+ GNUNET_CONFIGURATION_get_value_string (cfg, "dns",
+ "DNS_EXIT",
+ &dns_exit)) ||
+ ( (1 != inet_pton (AF_INET, dns_exit, &dns_exit4)) &&
+ (1 != inet_pton (AF_INET6, dns_exit, &dns_exit6)) ) ) )
{
- if ( (GNUNET_OK != open_port4 ()) &&
- (GNUNET_OK != open_port6 ()) )
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Failed to open any port to provide DNS exit\n"));
- GNUNET_SCHEDULER_shutdown ();
- return;
- }
+ GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
+ _("Configured to provide DNS exit, but no valid DNS server configured!\n"));
+ GNUNET_free_non_null (dns_exit);
+ dns_exit = NULL;
}
helper_argv[0] = GNUNET_strdup ("gnunet-dns");
return;
}
helper_argv[5] = ipv4mask;
- GNUNET_snprintf (port_s,
- sizeof (port_s),
- "%u",
- (unsigned int) dnsoutport);
- helper_argv[6] = GNUNET_strdup (port_s);
- helper_argv[7] = NULL;
+ helper_argv[6] = NULL;
if (NULL != dns_exit)
{
{
return (GNUNET_OK ==
GNUNET_SERVICE_run (argc, argv, "dns", GNUNET_SERVICE_OPTION_NONE,
- &run, NULL)) ? 0 : 1;
+ &run, NULL)) ? global_ret : 1;
}
projects / oweals / gnunet.git / blobdiff