/*
This file is part of GNUnet.
- (C) 2009 Christian Grothoff (and other contributing authors)
+ (C) 2009-2013 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 2, or (at your
+ 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
*/
/**
- * @file resolver/resolver_api.c
+ * @file util/resolver_api.c
* @brief resolver for writing a tool
* @author Christian Grothoff
*/
#include "platform.h"
-#include "gnunet_getopt_lib.h"
-#include "gnunet_client_lib.h"
+#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_resolver_service.h"
-#include "gnunet_server_lib.h"
#include "resolver.h"
+#define LOG(kind,...) GNUNET_log_from (kind, "resolver-api", __VA_ARGS__)
+
+#define LOG_STRERROR(kind,syscall) GNUNET_log_from_strerror (kind, "resolver-api", syscall)
+
+/**
+ * Maximum supported length for a hostname
+ */
+#define MAX_HOSTNAME 1024
+
+
+/**
+ * Possible hostnames for "loopback".
+ */
+static const char *loopback[] = {
+ "localhost",
+ "ip6-localnet",
+ NULL
+};
+
+
+/**
+ * Configuration.
+ */
+static const struct GNUNET_CONFIGURATION_Handle *resolver_cfg;
+
+/**
+ * Our connection to the resolver service, created on-demand, but then
+ * persists until error or shutdown.
+ */
+static struct GNUNET_CLIENT_Connection *client;
+
+/**
+ * Head of DLL of requests.
+ */
+static struct GNUNET_RESOLVER_RequestHandle *req_head;
/**
- * FIXME.
+ * Tail of DLL of requests.
*/
-struct GetAddressContext
+static struct GNUNET_RESOLVER_RequestHandle *req_tail;
+
+/**
+ * How long should we wait to reconnect?
+ */
+static struct GNUNET_TIME_Relative backoff;
+
+/**
+ * Task for reconnecting.
+ */
+static GNUNET_SCHEDULER_TaskIdentifier r_task;
+
+/**
+ * Task ID of shutdown task; only present while we have a
+ * connection to the resolver service.
+ */
+static GNUNET_SCHEDULER_TaskIdentifier s_task;
+
+
+/**
+ * Handle to a request given to the resolver. Can be used to cancel
+ * the request prior to the timeout or successful execution. Also
+ * used to track our internal state for the request.
+ */
+struct GNUNET_RESOLVER_RequestHandle
{
/**
- * FIXME.
+ * Next entry in DLL of requests.
*/
- GNUNET_RESOLVER_AddressCallback callback;
+ struct GNUNET_RESOLVER_RequestHandle *next;
/**
- * Closure for "callback".
+ * Previous entry in DLL of requests.
*/
- void *cls;
+ struct GNUNET_RESOLVER_RequestHandle *prev;
/**
- * FIXME.
+ * Callback if this is an name resolution request,
+ * otherwise NULL.
*/
- struct GNUNET_RESOLVER_GetMessage *msg;
+ GNUNET_RESOLVER_AddressCallback addr_callback;
+
+ /**
+ * Callback if this is a reverse lookup request,
+ * otherwise NULL.
+ */
+ GNUNET_RESOLVER_HostnameCallback name_callback;
/**
- * FIXME.
+ * Closure for the respective "callback".
*/
- struct GNUNET_CLIENT_Connection *client;
+ void *cls;
/**
- * FIXME.
+ * When should this request time out?
*/
struct GNUNET_TIME_Absolute timeout;
-};
+ /**
+ * Task handle for numeric lookups.
+ */
+ GNUNET_SCHEDULER_TaskIdentifier task;
-/**
- * Possible hostnames for "loopback".
- */
-static const char *loopback[] = {
- "localhost",
- "ip6-localnet",
- NULL
+ /**
+ * Desired address family.
+ */
+ int af;
+
+ /**
+ * Has this request been transmitted to the service?
+ * GNUNET_YES if transmitted
+ * GNUNET_YES if not transmitted
+ * GNUNET_SYSERR when request was canceled
+ */
+ int was_transmitted;
+
+ /**
+ * Did we add this request to the queue?
+ */
+ int was_queued;
+
+ /**
+ * Desired direction (IP to name or name to IP)
+ */
+ int direction;
+
+ /**
+ * GNUNET_YES if a response was received
+ */
+ int received_response;
+
+ /**
+ * Length of the data that follows this struct.
+ */
+ size_t data_len;
};
* (or equivalent).
*/
static void
-check_config (const struct GNUNET_CONFIGURATION_Handle *cfg)
+check_config ()
{
char *hostname;
unsigned int i;
- struct in_addr v4;
- struct in6_addr v6;
+ struct sockaddr_in v4;
+ struct sockaddr_in6 v6;
+ memset (&v4, 0, sizeof (v4));
+ v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+ v4.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v4.sin_len = sizeof (v4);
+#endif
+ memset (&v6, 0, sizeof (v6));
+ v6.sin6_family = AF_INET6;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v6.sin6_len = sizeof (v6);
+#endif
if (GNUNET_OK !=
- GNUNET_CONFIGURATION_get_value_string (cfg,
- "resolver",
- "HOSTNAME",
- &hostname))
- {
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Must specify `%s' for `%s' in configuration!\n"),
- "HOSTNAME",
- "resolver");
- GNUNET_assert (0);
- }
- if ( (0 == inet_pton (AF_INET,
- hostname,
- &v4)) ||
- (0 == inet_pton (AF_INET6,
- hostname,
- &v6)) )
+ GNUNET_CONFIGURATION_get_value_string (resolver_cfg, "resolver",
+ "HOSTNAME", &hostname))
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Must specify `%s' for `%s' in configuration!\n"), "HOSTNAME",
+ "resolver");
+ GNUNET_assert (0);
+ }
+ if ((1 != inet_pton (AF_INET, hostname, &v4)) ||
+ (1 != inet_pton (AF_INET6, hostname, &v6)))
+ {
+ GNUNET_free (hostname);
return;
+ }
i = 0;
- while (loopback[i] != NULL)
- if (0 == strcmp (loopback[i++], hostname))
- {
- GNUNET_free (hostname);
- return;
- }
- GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- _("Must specify `%s' for `%s' in configuration!\n"),
- "localhost",
- "resolver");
- GNUNET_free (hostname);
- GNUNET_assert (0);
+ while (NULL != loopback[i])
+ if (0 == strcasecmp (loopback[i++], hostname))
+ {
+ GNUNET_free (hostname);
+ return;
+ }
+ LOG (GNUNET_ERROR_TYPE_ERROR,
+ _("Must specify `%s' or numeric IP address for `%s' of `%s' in configuration!\n"),
+ "localhost", "HOSTNAME", "resolver");
+ GNUNET_free (hostname);
+ GNUNET_assert (0);
+}
+
+
+/**
+ * Create the connection to the resolver service.
+ *
+ * @param cfg configuration to use
+ */
+void
+GNUNET_RESOLVER_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
+{
+ GNUNET_assert (NULL != cfg);
+ backoff = GNUNET_TIME_UNIT_MILLISECONDS;
+ resolver_cfg = cfg;
+ check_config ();
+}
+
+
+/**
+ * Destroy the connection to the resolver service.
+ */
+void
+GNUNET_RESOLVER_disconnect ()
+{
+ GNUNET_assert (NULL == req_head);
+ GNUNET_assert (NULL == req_tail);
+ if (NULL != client)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Disconnecting from DNS service\n");
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ }
+ if (GNUNET_SCHEDULER_NO_TASK != r_task)
+ {
+ GNUNET_SCHEDULER_cancel (r_task);
+ r_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ if (GNUNET_SCHEDULER_NO_TASK != s_task)
+ {
+ GNUNET_SCHEDULER_cancel (s_task);
+ s_task = GNUNET_SCHEDULER_NO_TASK;
+ }
}
/**
* Convert IP address to string without DNS resolution.
*
- * @param sa the address
- * @param salen number of bytes in sa
+ * @param af address family
+ * @param ip the address
+ * @param ip_len number of bytes in ip
* @return address as a string, NULL on error
*/
static char *
-no_resolve (const struct sockaddr *sa, socklen_t salen)
+no_resolve (int af,
+ const void *ip, socklen_t ip_len)
{
- char *ret;
- char inet4[INET_ADDRSTRLEN];
- char inet6[INET6_ADDRSTRLEN];
+ char buf[INET6_ADDRSTRLEN];
- if (salen < sizeof (struct sockaddr))
- return NULL;
- switch (sa->sa_family)
+ switch (af)
+ {
+ case AF_INET:
+ if (ip_len != sizeof (struct in_addr))
+ return NULL;
+ if (NULL ==
+ inet_ntop (AF_INET, ip, buf, sizeof (buf)))
{
- case AF_INET:
- if (salen != sizeof (struct sockaddr_in))
- return NULL;
- inet_ntop (AF_INET,
- &((struct sockaddr_in *) sa)->sin_addr,
- inet4, INET_ADDRSTRLEN);
- ret = GNUNET_strdup (inet4);
- break;
- case AF_INET6:
- if (salen != sizeof (struct sockaddr_in6))
- return NULL;
- inet_ntop (AF_INET6,
- &((struct sockaddr_in6 *) sa)->sin6_addr,
- inet6, INET6_ADDRSTRLEN);
- ret = GNUNET_strdup (inet6);
- break;
- default:
- ret = NULL;
- break;
+ LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
+ return NULL;
}
- return ret;
+ break;
+ case AF_INET6:
+ if (ip_len != sizeof (struct in6_addr))
+ return NULL;
+ if (NULL ==
+ inet_ntop (AF_INET6, ip, buf, sizeof (buf)))
+ {
+ LOG_STRERROR (GNUNET_ERROR_TYPE_WARNING, "inet_ntop");
+ return NULL;
+ }
+ break;
+ default:
+ GNUNET_break (0);
+ return NULL;
+ }
+ return GNUNET_strdup (buf);
}
/**
- * FIXME
+ * Adjust exponential back-off and reconnect to the service.
+ */
+static void
+reconnect ();
+
+
+/**
+ * Process pending requests to the resolver.
+ */
+static void
+process_requests ();
+
+
+/**
+ * Process response with a hostname for a DNS lookup.
*
- * @param cls FIXME
- * @param msg FIXME
+ * @param cls our "struct GNUNET_RESOLVER_RequestHandle" context
+ * @param msg message with the hostname, NULL on error
*/
static void
-handle_address_response (void *cls, const struct GNUNET_MessageHeader *msg)
+handle_response (void *cls, const struct GNUNET_MessageHeader *msg)
{
- struct GetAddressContext *gac = cls;
+ struct GNUNET_RESOLVER_RequestHandle *rh = cls;
uint16_t size;
- const struct sockaddr *sa;
- socklen_t salen;
-
- if (msg == NULL)
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Receiving response from DNS service\n");
+ if (NULL == msg)
+ {
+ char buf[INET6_ADDRSTRLEN];
+
+ if (NULL != rh->name_callback)
+ LOG (GNUNET_ERROR_TYPE_INFO,
+ _("Timeout trying to resolve IP address `%s'.\n"),
+ inet_ntop (rh->af, (const void *) &rh[1], buf, sizeof(buf)));
+ else
+ LOG (GNUNET_ERROR_TYPE_INFO,
+ _("Timeout trying to resolve hostname `%s'.\n"),
+ (const char *) &rh[1]);
+ /* check if request was canceled */
+ if (GNUNET_SYSERR != rh->was_transmitted)
{
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Timeout trying to resolve hostname.\n"));
- gac->callback (gac->cls, NULL, 0);
- GNUNET_CLIENT_disconnect (gac->client);
- GNUNET_free (gac);
- return;
+ if (NULL != rh->name_callback)
+ {
+ /* no reverse lookup was successful, return ip as string */
+ if (rh->received_response == GNUNET_NO)
+ {
+ rh->name_callback (rh->cls, no_resolve (rh->af, &rh[1], rh->data_len));
+ rh->name_callback (rh->cls, NULL);
+ }
+ /* at least one reverse lookup was successful */
+ else
+ rh->name_callback (rh->cls, NULL);
+ }
+ if (NULL != rh->addr_callback)
+ rh->addr_callback (rh->cls, NULL, 0);
}
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ reconnect ();
+ return;
+ }
if (GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE != ntohs (msg->type))
+ {
+ GNUNET_break (0);
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ reconnect ();
+ return;
+ }
+ size = ntohs (msg->size);
+ /* message contains not data, just header */
+ if (size == sizeof (struct GNUNET_MessageHeader))
+ {
+ /* check if request was canceled */
+ if (rh->was_transmitted != GNUNET_SYSERR)
+ {
+ if (NULL != rh->name_callback)
+ rh->name_callback (rh->cls, NULL);
+ if (NULL != rh->addr_callback)
+ rh->addr_callback (rh->cls, NULL, 0);
+ }
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ process_requests ();
+ return;
+ }
+ /* return reverse lookup results to caller */
+ if (NULL != rh->name_callback)
+ {
+ const char *hostname;
+
+ hostname = (const char *) &msg[1];
+ if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
{
GNUNET_break (0);
- gac->callback (gac->cls, NULL, 0);
- GNUNET_CLIENT_disconnect (gac->client);
- GNUNET_free (gac);
+ if (rh->was_transmitted != GNUNET_SYSERR)
+ rh->name_callback (rh->cls, NULL);
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ reconnect ();
return;
}
-
- size = ntohs (msg->size);
- if (size == sizeof (struct GNUNET_MessageHeader))
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Resolver returns `%s' for IP `%s'.\n",
+ hostname, GNUNET_a2s ((const void *) &rh[1], rh->data_len));
+ if (rh->was_transmitted != GNUNET_SYSERR)
+ rh->name_callback (rh->cls, hostname);
+ rh->received_response = GNUNET_YES;
+ GNUNET_CLIENT_receive (client, &handle_response, rh,
+ GNUNET_TIME_absolute_get_remaining (rh->timeout));
+ }
+ /* return lookup results to caller */
+ if (NULL != rh->addr_callback)
+ {
+ struct sockaddr_in v4;
+ struct sockaddr_in6 v6;
+ const struct sockaddr *sa;
+ socklen_t salen;
+ const void *ip;
+ size_t ip_len;
+
+ ip = &msg[1];
+ ip_len = size - sizeof (struct GNUNET_MessageHeader);
+ if (ip_len == sizeof (struct in_addr))
{
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Received end message resolving hostname.\n"));
+ memset (&v4, 0, sizeof (v4));
+ v4.sin_family = AF_INET;
+ v4.sin_addr = *(struct in_addr*) ip;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v4.sin_len = sizeof (v4);
#endif
- gac->callback (gac->cls, NULL, 0);
- GNUNET_CLIENT_disconnect (gac->client);
- GNUNET_free (gac);
- return;
+ salen = sizeof (v4);
+ sa = (const struct sockaddr *) &v4;
+ }
+ else if (ip_len == sizeof (struct in6_addr))
+ {
+ memset (&v6, 0, sizeof (v6));
+ v6.sin6_family = AF_INET6;
+ v6.sin6_addr = *(struct in6_addr*) ip;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v6.sin6_len = sizeof (v6);
+#endif
+ salen = sizeof (v6);
+ sa = (const struct sockaddr *) &v6;
}
- sa = (const struct sockaddr *) &msg[1];
- salen = size - sizeof (struct GNUNET_MessageHeader);
- if (salen < sizeof (struct sockaddr))
+ else
{
GNUNET_break (0);
- gac->callback (gac->cls, NULL, 0);
- GNUNET_CLIENT_disconnect (gac->client);
- GNUNET_free (gac);
+ if (rh->was_transmitted != GNUNET_SYSERR)
+ rh->addr_callback (rh->cls, NULL, 0);
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ reconnect ();
return;
}
-#if DEBUG_RESOLVER
- {
- char *ips = no_resolve (sa, salen);
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, _("Resolver returns `%s'.\n"), ips);
- GNUNET_free (ips);
+ rh->addr_callback (rh->cls, sa, salen);
+ GNUNET_CLIENT_receive (client, &handle_response, rh,
+ GNUNET_TIME_absolute_get_remaining (rh->timeout));
}
-#endif
- gac->callback (gac->cls, sa, salen);
- GNUNET_CLIENT_receive (gac->client,
- &handle_address_response,
- gac,
- GNUNET_TIME_absolute_get_remaining (gac->timeout));
}
/**
- * FIXME
+ * We've been asked to lookup the address for a hostname and were
+ * given a valid numeric string. Perform the callbacks for the
+ * numeric addresses.
*
- * @param cls FIXME
- * @param size number of bytes available in buf
- * @param buf target buffer, NULL on error
- * @return number of bytes written to buf
+ * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
+ * @param tc unused scheduler context
*/
-static size_t
-transmit_get_ip (void *cls, size_t size, void *buf)
+static void
+numeric_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
- struct GetAddressContext *actx = cls;
- uint16_t ms;
+ struct GNUNET_RESOLVER_RequestHandle *rh = cls;
+ struct sockaddr_in v4;
+ struct sockaddr_in6 v6;
+ const char *hostname;
- if (buf == NULL)
+ memset (&v4, 0, sizeof (v4));
+ v4.sin_family = AF_INET;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v4.sin_len = sizeof (v4);
+#endif
+ memset (&v6, 0, sizeof (v6));
+ v6.sin6_family = AF_INET6;
+#if HAVE_SOCKADDR_IN_SIN_LEN
+ v6.sin6_len = sizeof (v6);
+#endif
+ hostname = (const char *) &rh[1];
+ if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET)) &&
+ (1 == inet_pton (AF_INET, hostname, &v4.sin_addr)))
+ {
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
+ if ((rh->af == AF_UNSPEC) &&
+ (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
{
- /* timeout / error */
- GNUNET_free (actx->msg);
- actx->callback (actx->cls, NULL, 0);
- GNUNET_CLIENT_disconnect (actx->client);
- GNUNET_free (actx);
- return 0;
+ /* this can happen on some systems IF "hostname" is "localhost" */
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
}
- ms = ntohs (actx->msg->header.size);
- GNUNET_assert (size >= ms);
- memcpy (buf, actx->msg, ms);
- GNUNET_free (actx->msg);
- actx->msg = NULL;
- GNUNET_CLIENT_receive (actx->client,
- &handle_address_response,
- actx,
- GNUNET_TIME_absolute_get_remaining (actx->timeout));
- return ms;
+ rh->addr_callback (rh->cls, NULL, 0);
+ GNUNET_free (rh);
+ return;
+ }
+ if (((rh->af == AF_UNSPEC) || (rh->af == AF_INET6)) &&
+ (1 == inet_pton (AF_INET6, hostname, &v6.sin6_addr)))
+ {
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
+ rh->addr_callback (rh->cls, NULL, 0);
+ GNUNET_free (rh);
+ return;
+ }
+ /* why are we here? this task should not have been scheduled! */
+ GNUNET_assert (0);
+ GNUNET_free (rh);
}
-
/**
- * Convert a string to one or more IP addresses.
+ * We've been asked to lookup the address for a hostname and were
+ * given a variant of "loopback". Perform the callbacks for the
+ * respective loopback numeric addresses.
*
- * @param sched scheduler to use
- * @param cfg configuration to use
- * @param hostname the hostname to resolve
- * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any"
- * @param callback function to call with addresses
- * @param callback_cls closure for callback
- * @param timeout how long to try resolving
+ * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
+ * @param tc unused scheduler context
*/
-void
-GNUNET_RESOLVER_ip_get (struct GNUNET_SCHEDULER_Handle *sched,
- const struct GNUNET_CONFIGURATION_Handle *cfg,
- const char *hostname,
- int domain,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_RESOLVER_AddressCallback callback,
- void *callback_cls)
+static void
+loopback_resolution (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
- struct GNUNET_CLIENT_Connection *client;
- struct GNUNET_RESOLVER_GetMessage *msg;
- struct GetAddressContext *actx;
- size_t slen;
- unsigned int i;
+ struct GNUNET_RESOLVER_RequestHandle *rh = cls;
struct sockaddr_in v4;
struct sockaddr_in6 v6;
- memset (&v4, 0, sizeof(v4));
- v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+ memset (&v4, 0, sizeof (v4));
+ v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
v4.sin_family = AF_INET;
#if HAVE_SOCKADDR_IN_SIN_LEN
- v4.sin_len = sizeof(v4);
+ v4.sin_len = sizeof (v4);
#endif
- memset (&v6, 0, sizeof(v6));
+ memset (&v6, 0, sizeof (v6));
v6.sin6_family = AF_INET6;
#if HAVE_SOCKADDR_IN_SIN_LEN
- v6.sin6_len = sizeof(v6);
+ v6.sin6_len = sizeof (v6);
#endif
- /* first, check if this is a numeric address */
- if ( ( (domain == AF_UNSPEC) || (domain == AF_INET) ) &&
- (0 == inet_pton (AF_INET,
- hostname,
- &v4.sin_addr)) )
- {
- callback (callback_cls,
- (const struct sockaddr*) &v4,
- sizeof(v4));
- if ( (domain == AF_UNSPEC) &&
- (0 == inet_pton (AF_INET6,
- hostname,
- &v6.sin6_addr)) )
- {
- /* this can happen on some systems IF "hostname" is "localhost" */
- callback (callback_cls,
- (const struct sockaddr*) &v6,
- sizeof(v6));
- }
- callback (callback_cls, NULL, 0);
- return;
- }
- if ( ( (domain == AF_UNSPEC) ||(domain == AF_INET) ) &&
- (0 == inet_pton (AF_INET6,
- hostname,
- &v6.sin6_addr)) )
- {
- callback (callback_cls,
- (const struct sockaddr*) &v6,
- sizeof(v6));
- callback (callback_cls, NULL, 0);
- return;
- }
- check_config (cfg);
- /* then, check if this is a loopback address */
- i = 0;
- while (loopback[i] != NULL)
- if (0 == strcmp (loopback[i++], hostname))
- {
- v4.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
- v6.sin6_addr = in6addr_loopback;
- switch (domain)
- {
- case AF_INET:
- callback (callback_cls,
- (const struct sockaddr*) &v4,
- sizeof(v4));
- break;
- case AF_INET6:
- callback (callback_cls,
- (const struct sockaddr*) &v6,
- sizeof(v6));
- break;
- case AF_UNSPEC:
- callback (callback_cls,
- (const struct sockaddr*) &v6,
- sizeof(v6));
- callback (callback_cls,
- (const struct sockaddr*) &v4,
- sizeof(v4));
- break;
- }
- callback (callback_cls, NULL, 0);
- return;
- }
- slen = strlen (hostname) + 1;
- if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
- GNUNET_SERVER_MAX_MESSAGE_SIZE)
- {
- GNUNET_break (0);
- callback (callback_cls, NULL, 0);
- return;
- }
- client = GNUNET_CLIENT_connect (sched, "resolver", cfg);
- if (client == NULL)
- {
- callback (callback_cls, NULL, 0);
- return;
- }
- msg = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_GetMessage) + slen);
- msg->header.size =
- htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + slen);
- msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
- msg->direction = htonl (GNUNET_NO);
- msg->domain = htonl (domain);
- memcpy (&msg[1], hostname, slen);
- actx = GNUNET_malloc (sizeof (struct GetAddressContext));
- actx->callback = callback;
- actx->cls = callback_cls;
- actx->client = client;
- actx->timeout = GNUNET_TIME_relative_to_absolute (timeout);
- actx->msg = msg;
-
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Resolver requests DNS resolution of hostname `%s'.\n"),
- hostname);
-#endif
- if (NULL ==
- GNUNET_CLIENT_notify_transmit_ready (client,
- slen +
- sizeof (struct
- GNUNET_RESOLVER_GetMessage),
- timeout, &transmit_get_ip, actx))
- {
- GNUNET_free (msg);
- GNUNET_free (actx);
- callback (callback_cls, NULL, 0);
- GNUNET_CLIENT_disconnect (client);
- return;
- }
+ v6.sin6_addr = in6addr_loopback;
+ switch (rh->af)
+ {
+ case AF_INET:
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
+ break;
+ case AF_INET6:
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
+ break;
+ case AF_UNSPEC:
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v6, sizeof (v6));
+ rh->addr_callback (rh->cls, (const struct sockaddr *) &v4, sizeof (v4));
+ break;
+ default:
+ GNUNET_break (0);
+ break;
+ }
+ rh->addr_callback (rh->cls, NULL, 0);
+ GNUNET_free (rh);
}
/**
- * FIXME.
+ * Task executed on system shutdown.
*/
-struct GetHostnameContext
+static void
+shutdown_task (void *cls,
+ const struct GNUNET_SCHEDULER_TaskContext *tc)
{
+ s_task = GNUNET_SCHEDULER_NO_TASK;
+ GNUNET_RESOLVER_disconnect ();
+ backoff = GNUNET_TIME_UNIT_MILLISECONDS;
+}
- /**
- * FIXME.
- */
- GNUNET_RESOLVER_HostnameCallback callback;
-
- /**
- * FIXME.
- */
- void *cls;
-
- /**
- * FIXME.
- */
+
+/**
+ * Process pending requests to the resolver.
+ */
+static void
+process_requests ()
+{
struct GNUNET_RESOLVER_GetMessage *msg;
-
- /**
- * FIXME.
- */
- struct GNUNET_CLIENT_Connection *client;
-
- /**
- * FIXME.
- */
- struct GNUNET_TIME_Absolute timeout;
-};
+ char buf[GNUNET_SERVER_MAX_MESSAGE_SIZE - 1] GNUNET_ALIGN;
+ struct GNUNET_RESOLVER_RequestHandle *rh;
+
+ if (NULL == client)
+ {
+ reconnect ();
+ return;
+ }
+ rh = req_head;
+ if (NULL == rh)
+ {
+ /* nothing to do, release socket really soon if there is nothing
+ * else happening... */
+ s_task =
+ GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_MILLISECONDS,
+ &shutdown_task, NULL);
+ return;
+ }
+ if (GNUNET_YES == rh->was_transmitted)
+ return; /* waiting for reply */
+ msg = (struct GNUNET_RESOLVER_GetMessage *) buf;
+ msg->header.size =
+ htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + rh->data_len);
+ msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
+ msg->direction = htonl (rh->direction);
+ msg->af = htonl (rh->af);
+ memcpy (&msg[1], &rh[1], rh->data_len);
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Transmitting DNS resolution request to DNS service\n");
+ if (GNUNET_OK !=
+ GNUNET_CLIENT_transmit_and_get_response (client, &msg->header,
+ GNUNET_TIME_absolute_get_remaining
+ (rh->timeout), GNUNET_YES,
+ &handle_response, rh))
+ {
+ GNUNET_CLIENT_disconnect (client);
+ client = NULL;
+ GNUNET_break (0);
+ reconnect ();
+ return;
+ }
+ rh->was_transmitted = GNUNET_YES;
+}
/**
- * FIXME.
+ * Now try to reconnect to the resolver service.
*
- * @param cls FIXME
- * @param msg FIXME
+ * @param cls NULL
+ * @param tc scheduler context
*/
static void
-handle_hostname_response (void *cls, const struct GNUNET_MessageHeader *msg)
+reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
- struct GetHostnameContext *ghc = cls;
- uint16_t size;
- const char *hostname;
+ r_task = GNUNET_SCHEDULER_NO_TASK;
+ if (NULL == req_head)
+ return; /* no work pending */
+ if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
+ return;
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Trying to connect to DNS service\n");
+ client = GNUNET_CLIENT_connect ("resolver", resolver_cfg);
+ if (NULL == client)
+ {
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Failed to connect, will try again later\n");
+ reconnect ();
+ return;
+ }
+ process_requests ();
+}
- if (msg == NULL)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_INFO,
- _("Timeout trying to resolve IP address.\n"));
- ghc->callback (ghc->cls, NULL);
- GNUNET_CLIENT_disconnect (ghc->client);
- GNUNET_free (ghc);
- return;
- }
- size = ntohs (msg->size);
- if (size == sizeof (struct GNUNET_MessageHeader))
- {
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Received end message resolving IP address.\n"));
-#endif
- ghc->callback (ghc->cls, NULL);
- GNUNET_CLIENT_disconnect (ghc->client);
- GNUNET_free (ghc);
- return;
- }
- hostname = (const char *) &msg[1];
- if (hostname[size - sizeof (struct GNUNET_MessageHeader) - 1] != '\0')
+
+/**
+ * Adjust exponential back-off and reconnect to the service.
+ */
+static void
+reconnect ()
+{
+ struct GNUNET_RESOLVER_RequestHandle *rh;
+
+ if (GNUNET_SCHEDULER_NO_TASK != r_task)
+ return;
+ GNUNET_assert (NULL == client);
+ if (NULL != (rh = req_head))
+ {
+ switch (rh->was_transmitted)
{
- GNUNET_break (0);
- ghc->callback (ghc->cls, NULL);
- GNUNET_CLIENT_disconnect (ghc->client);
- GNUNET_free (ghc);
- return;
+ case GNUNET_NO:
+ /* nothing more to do */
+ break;
+ case GNUNET_YES:
+ /* disconnected, transmit again! */
+ rh->was_transmitted = GNUNET_NO;
+ break;
+ case GNUNET_SYSERR:
+ /* request was cancelled, remove entirely */
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ break;
+ default:
+ GNUNET_assert (0);
+ break;
}
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Resolver returns `%s'.\n"), hostname);
-#endif
- ghc->callback (ghc->cls, hostname);
- GNUNET_CLIENT_receive (ghc->client,
- &handle_hostname_response,
- ghc,
- GNUNET_TIME_absolute_get_remaining (ghc->timeout));
+ }
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Will try to connect to DNS service in %s\n",
+ GNUNET_STRINGS_relative_time_to_string (backoff, GNUNET_YES));
+ GNUNET_assert (NULL != resolver_cfg);
+ r_task = GNUNET_SCHEDULER_add_delayed (backoff, &reconnect_task, NULL);
+ backoff = GNUNET_TIME_STD_BACKOFF (backoff);
}
/**
- * FIXME
+ * Convert a string to one or more IP addresses.
*
- * @param cls FIXME
- * @param size number of bytes available in buf
- * @param buf target buffer, NULL on error
- * @return number of bytes written to buf
+ * @param hostname the hostname to resolve
+ * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
+ * @param callback function to call with addresses
+ * @param callback_cls closure for callback
+ * @param timeout how long to try resolving
+ * @return handle that can be used to cancel the request, NULL on error
*/
-static size_t
-transmit_get_hostname (void *cls, size_t size, void *buf)
+struct GNUNET_RESOLVER_RequestHandle *
+GNUNET_RESOLVER_ip_get (const char *hostname, int af,
+ struct GNUNET_TIME_Relative timeout,
+ GNUNET_RESOLVER_AddressCallback callback,
+ void *callback_cls)
{
- struct GetHostnameContext *hctx = cls;
- uint16_t msize;
+ struct GNUNET_RESOLVER_RequestHandle *rh;
+ size_t slen;
+ unsigned int i;
+ struct in_addr v4;
+ struct in6_addr v6;
- if (buf == NULL)
+ slen = strlen (hostname) + 1;
+ if (slen + sizeof (struct GNUNET_RESOLVER_GetMessage) >=
+ GNUNET_SERVER_MAX_MESSAGE_SIZE)
+ {
+ GNUNET_break (0);
+ return NULL;
+ }
+ rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
+ rh->af = af;
+ rh->addr_callback = callback;
+ rh->cls = callback_cls;
+ memcpy (&rh[1], hostname, slen);
+ rh->data_len = slen;
+ rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+ rh->direction = GNUNET_NO;
+ /* first, check if this is a numeric address */
+ if (((1 == inet_pton (AF_INET, hostname, &v4)) &&
+ ((af == AF_INET) || (af == AF_UNSPEC))) ||
+ ((1 == inet_pton (AF_INET6, hostname, &v6)) &&
+ ((af == AF_INET6) || (af == AF_UNSPEC))))
+ {
+ rh->task = GNUNET_SCHEDULER_add_now (&numeric_resolution, rh);
+ return rh;
+ }
+ /* then, check if this is a loopback address */
+ i = 0;
+ while (NULL != loopback[i])
+ if (0 == strcasecmp (loopback[i++], hostname))
{
- GNUNET_free (hctx->msg);
- hctx->callback (hctx->cls, NULL);
- GNUNET_CLIENT_disconnect (hctx->client);
- GNUNET_free (hctx);
- return 0;
+ rh->task = GNUNET_SCHEDULER_add_now (&loopback_resolution, rh);
+ return rh;
}
- msize = ntohs (hctx->msg->header.size);
- GNUNET_assert (size >= msize);
- memcpy (buf, hctx->msg, msize);
- GNUNET_free (hctx->msg);
- hctx->msg = NULL;
- GNUNET_CLIENT_receive (hctx->client,
- &handle_hostname_response,
- hctx,
- GNUNET_TIME_absolute_get_remaining (hctx->timeout));
- return msize;
+ GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
+ rh->was_queued = GNUNET_YES;
+ if (s_task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (s_task);
+ s_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ process_requests ();
+ return rh;
}
+/**
+ * We've been asked to convert an address to a string without
+ * a reverse lookup. Do it.
+ *
+ * @param cls struct GNUNET_RESOLVER_RequestHandle for the request
+ * @param tc unused scheduler context
+ */
+static void
+numeric_reverse (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
+{
+ struct GNUNET_RESOLVER_RequestHandle *rh = cls;
+ char *result;
+
+ result = no_resolve (rh->af, &rh[1], rh->data_len);
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Resolver returns `%s'.\n", result);
+ if (result != NULL)
+ {
+ rh->name_callback (rh->cls, result);
+ GNUNET_free (result);
+ }
+ rh->name_callback (rh->cls, NULL);
+ GNUNET_free (rh);
+}
/**
* Get an IP address as a string.
*
- * @param sched scheduler to use
- * @param cfg configuration to use
* @param sa host address
* @param salen length of host address
* @param do_resolve use GNUNET_NO to return numeric hostname
* @param timeout how long to try resolving
* @param callback function to call with hostnames
+ * last callback is NULL when finished
* @param cls closure for callback
+ * @return handle that can be used to cancel the request
*/
-void
-GNUNET_RESOLVER_hostname_get (struct GNUNET_SCHEDULER_Handle *sched,
- const struct GNUNET_CONFIGURATION_Handle *cfg,
- const struct sockaddr *sa,
- socklen_t salen,
+struct GNUNET_RESOLVER_RequestHandle *
+GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa, socklen_t salen,
int do_resolve,
struct GNUNET_TIME_Relative timeout,
GNUNET_RESOLVER_HostnameCallback callback,
void *cls)
{
- char *result;
- struct GNUNET_CLIENT_Connection *client;
- struct GNUNET_RESOLVER_GetMessage *msg;
- struct GetHostnameContext *hctx;
+ struct GNUNET_RESOLVER_RequestHandle *rh;
+ size_t ip_len;
+ const void *ip;
- check_config (cfg);
+ check_config ();
+ switch (sa->sa_family)
+ {
+ case AF_INET:
+ ip_len = sizeof (struct in_addr);
+ ip = &((const struct sockaddr_in*)sa)->sin_addr;
+ break;
+ case AF_INET6:
+ ip_len = sizeof (struct in6_addr);
+ ip = &((const struct sockaddr_in6*)sa)->sin6_addr;
+ break;
+ default:
+ GNUNET_break (0);
+ return NULL;
+ }
+ rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + salen);
+ rh->name_callback = callback;
+ rh->cls = cls;
+ rh->af = sa->sa_family;
+ rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
+ memcpy (&rh[1], ip, ip_len);
+ rh->data_len = ip_len;
+ rh->direction = GNUNET_YES;
+ rh->received_response = GNUNET_NO;
if (GNUNET_NO == do_resolve)
- {
- result = no_resolve (sa, salen);
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Resolver returns `%s'.\n"), result);
-#endif
- callback (cls, result);
- if (result != NULL)
- {
- GNUNET_free (result);
- callback (cls, NULL);
- }
- return;
- }
- if (salen + sizeof (struct GNUNET_RESOLVER_GetMessage) >
- GNUNET_SERVER_MAX_MESSAGE_SIZE)
- {
- GNUNET_break (0);
- callback (cls, NULL);
- return;
- }
- client = GNUNET_CLIENT_connect (sched, "resolver", cfg);
- if (client == NULL)
- {
- callback (cls, NULL);
- return;
- }
- msg = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_GetMessage) + salen);
- msg->header.size =
- htons (sizeof (struct GNUNET_RESOLVER_GetMessage) + salen);
- msg->header.type = htons (GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
- msg->direction = htonl (GNUNET_YES);
- msg->domain = htonl (sa->sa_family);
- memcpy (&msg[1], sa, salen);
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Resolver requests DNS resolution of IP address.\n"));
-#endif
- hctx = GNUNET_malloc (sizeof (struct GetHostnameContext));
- hctx->callback = callback;
- hctx->cls = cls;
- hctx->client = client;
- hctx->timeout = GNUNET_TIME_relative_to_absolute (timeout);
- hctx->msg = msg;
- if (NULL ==
- GNUNET_CLIENT_notify_transmit_ready (client,
- sizeof (struct
- GNUNET_RESOLVER_GetMessage)
- + salen, timeout,
- &transmit_get_hostname, hctx))
- {
- GNUNET_free (msg);
- callback (cls, NULL);
- GNUNET_CLIENT_disconnect (client);
- GNUNET_free (hctx);
- }
+ {
+ rh->task = GNUNET_SCHEDULER_add_now (&numeric_reverse, rh);
+ return rh;
+ }
+ GNUNET_CONTAINER_DLL_insert_tail (req_head, req_tail, rh);
+ rh->was_queued = GNUNET_YES;
+ if (s_task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (s_task);
+ s_task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ process_requests ();
+ return rh;
}
+
/**
- * Maximum supported length of hostname
+ * Get local fully qualified af name
+ *
+ * @return fqdn
*/
-#define MAX_HOSTNAME 1024
+char *
+GNUNET_RESOLVER_local_fqdn_get ()
+{
+ struct hostent *host;
+ char hostname[GNUNET_OS_get_hostname_max_length () + 1];
+
+ if (0 != gethostname (hostname, sizeof (hostname) - 1))
+ {
+ LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+ "gethostname");
+ return NULL;
+ }
+ LOG (GNUNET_ERROR_TYPE_DEBUG, "Resolving our FQDN `%s'\n", hostname);
+ host = gethostbyname (hostname);
+ if (NULL == host)
+ {
+ LOG (GNUNET_ERROR_TYPE_ERROR, _("Could not resolve our FQDN : %s\n"),
+ hstrerror (h_errno));
+ return NULL;
+ }
+ return GNUNET_strdup (host->h_name);
+}
/**
- * Resolve our hostname to an IP address.
+ * Looking our own hostname.
*
- * @param sched scheduler to use
- * @param cfg configuration to use
- * @param domain AF_INET or AF_INET6; use AF_UNSPEC for "any"
+ * @param af AF_INET or AF_INET6; use AF_UNSPEC for "any"
* @param callback function to call with addresses
* @param cls closure for callback
* @param timeout how long to try resolving
+ * @return handle that can be used to cancel the request, NULL on error
*/
-void
-GNUNET_RESOLVER_hostname_resolve (struct GNUNET_SCHEDULER_Handle *sched,
- const struct GNUNET_CONFIGURATION_Handle *cfg,
- int domain,
+struct GNUNET_RESOLVER_RequestHandle *
+GNUNET_RESOLVER_hostname_resolve (int af,
struct GNUNET_TIME_Relative timeout,
GNUNET_RESOLVER_AddressCallback callback,
void *cls)
{
- char hostname[MAX_HOSTNAME];
+ char hostname[GNUNET_OS_get_hostname_max_length () + 1];
- check_config (cfg);
if (0 != gethostname (hostname, sizeof (hostname) - 1))
- {
- GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR |
- GNUNET_ERROR_TYPE_BULK, "gethostname");
- callback (cls, NULL, 0);
- return;
- }
-#if DEBUG_RESOLVER
- GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- _("Resolving our hostname `%s'\n"), hostname);
-#endif
- GNUNET_RESOLVER_ip_get (sched,
- cfg, hostname, domain, timeout, callback, cls);
+ {
+ LOG_STRERROR (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
+ "gethostname");
+ return NULL;
+ }
+ LOG (GNUNET_ERROR_TYPE_DEBUG,
+ "Resolving our hostname `%s'\n",
+ hostname);
+ return GNUNET_RESOLVER_ip_get (hostname, af, timeout, callback, cls);
}
+/**
+ * Cancel a request that is still pending with the resolver.
+ * Note that a client MUST NOT cancel a request that has
+ * been completed (i.e, the callback has been called to
+ * signal timeout or the final result).
+ *
+ * @param rh handle of request to cancel
+ */
+void
+GNUNET_RESOLVER_request_cancel (struct GNUNET_RESOLVER_RequestHandle *rh)
+{
+ if (rh->task != GNUNET_SCHEDULER_NO_TASK)
+ {
+ GNUNET_SCHEDULER_cancel (rh->task);
+ rh->task = GNUNET_SCHEDULER_NO_TASK;
+ }
+ if (rh->was_transmitted == GNUNET_NO)
+ {
+ if (rh->was_queued == GNUNET_YES)
+ GNUNET_CONTAINER_DLL_remove (req_head, req_tail, rh);
+ GNUNET_free (rh);
+ return;
+ }
+ GNUNET_assert (rh->was_transmitted == GNUNET_YES);
+ rh->was_transmitted = GNUNET_SYSERR; /* mark as cancelled */
+}
/* end of resolver_api.c */
projects / oweals / gnunet.git / blobdiff