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[GNUnet-SVN] [gnunet] branch master updated: use unique 32-bit IDs for D
From: |
gnunet |
Subject: |
[GNUnet-SVN] [gnunet] branch master updated: use unique 32-bit IDs for DNS requests to avoid random confusions, handle additional and authoritative records as well |
Date: |
Thu, 18 Oct 2018 14:55:19 +0200 |
This is an automated email from the git hooks/post-receive script.
grothoff pushed a commit to branch master
in repository gnunet.
The following commit(s) were added to refs/heads/master by this push:
new c7c6446e3 use unique 32-bit IDs for DNS requests to avoid random
confusions, handle additional and authoritative records as well
c7c6446e3 is described below
commit c7c6446e3ea37531b67252a452937f3578570a57
Author: Christian Grothoff <address@hidden>
AuthorDate: Thu Oct 18 14:55:17 2018 +0200
use unique 32-bit IDs for DNS requests to avoid random confusions, handle
additional and authoritative records as well
---
src/arm/test_gnunet_service_arm.c | 14 +--
src/util/gnunet-service-resolver.c | 206 +++++++++++++++++++++++++++++--------
src/util/resolver.h | 14 +--
src/util/resolver_api.c | 28 ++---
4 files changed, 185 insertions(+), 77 deletions(-)
diff --git a/src/arm/test_gnunet_service_arm.c
b/src/arm/test_gnunet_service_arm.c
index 8b6d09bd9..fd5244ec2 100644
--- a/src/arm/test_gnunet_service_arm.c
+++ b/src/arm/test_gnunet_service_arm.c
@@ -112,7 +112,7 @@ hostname_resolve_cb (void *cls,
if (NULL == addr)
{
GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
- "Name not resolved!\n");
+ "Failed to resolve our own hostname!\n");
GNUNET_break (0);
ret = 3;
GNUNET_ARM_request_service_stop (arm,
@@ -200,7 +200,7 @@ main (int argc, char *av[])
FPRINTF (stderr,
"%s",
"Failed to determine my own hostname, testcase not run.\n");
- return 0;
+ return 77;
}
if ( (0 == strcmp (hostname,
"localhost")) ||
@@ -210,6 +210,8 @@ main (int argc, char *av[])
/* we cannot use 'localhost' as this would not trigger the
resolver service (see resolver_api.c); so in this case,
we fall back to (ab)using gnu.org. */
+ GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
+ "Falling back to `www.gnu.org'\n");
strcpy (hostname,
"www.gnu.org");
}
@@ -224,7 +226,7 @@ main (int argc, char *av[])
FPRINTF (stderr,
"Failed to resolve my hostname `%s', testcase not run.\n",
hostname);
- return 0;
+ return 77;
}
freeaddrinfo (ai);
}
@@ -240,7 +242,7 @@ main (int argc, char *av[])
FPRINTF (stderr,
"Failed to resolve my hostname `%s', testcase not run.\n",
hostname);
- return 0;
+ return 77;
}
}
#elif HAVE_GETHOSTBYNAME
@@ -253,13 +255,13 @@ main (int argc, char *av[])
FPRINTF (stderr,
"Failed to resolve my hostname `%s', testcase not run.\n",
hostname);
- return 0;
+ return 77;
}
}
#else
FPRINTF (stderr,
"libc fails to have resolver function, testcase not run.\n");
- return 0;
+ return 77;
#endif
GNUNET_log_setup ("test-gnunet-service-arm",
"WARNING",
diff --git a/src/util/gnunet-service-resolver.c
b/src/util/gnunet-service-resolver.c
index 90ed746b6..252408466 100644
--- a/src/util/gnunet-service-resolver.c
+++ b/src/util/gnunet-service-resolver.c
@@ -143,7 +143,7 @@ struct ActiveLookup
* Unique request ID of a client if a query for this hostname/record_type
* is currently pending, undefined otherwise.
*/
- uint16_t request_id;
+ uint32_t client_request_id;
/**
* Unique DNS request ID of a client if a query for this hostname/record_type
@@ -180,10 +180,16 @@ static struct ActiveLookup *lookup_tail;
static struct GNUNET_DNSSTUB_Context *dnsstub_ctx;
/**
+ * My domain, to be appended to the hostname to get a FQDN.
+ */
+static char *my_domain;
+
+/**
* How many entries do we have in #cache_head DLL?
*/
static unsigned int cache_size;
+
/**
* Remove @a entry from cache.
*
@@ -262,6 +268,28 @@ extract_dns_server (const char* line,
/**
+ * Find out if the configuration file line contains a string
+ * starting with "search ", and if so, return a copy of
+ * the machine's search domain.
+ *
+ * @param line line to parse
+ * @param line_len number of characters in @a line
+ * @return NULL if no nameserver is configured in this @a line
+ */
+static char *
+extract_search_domain (const char* line,
+ size_t line_len)
+{
+ if (0 == strncmp (line,
+ "search ",
+ strlen ("search ")))
+ return GNUNET_strndup (line + strlen ("search "),
+ line_len - strlen ("search "));
+ return NULL;
+}
+
+
+/**
* Reads the list of nameservers from /etc/resolve.conf
*
* @param server_addrs[out] a list of null-terminated server address strings
@@ -306,9 +334,16 @@ lookup_dns_servers (char ***server_addrs)
dns_server = extract_dns_server (buf + read_offset,
line_len);
if (NULL != dns_server)
+ {
GNUNET_array_append (*server_addrs,
num_dns_servers,
dns_server);
+ }
+ else if (NULL == my_domain)
+ {
+ my_domain = extract_search_domain (buf + read_offset,
+ line_len);
+ }
read_offset += line_len + 1;
}
GNUNET_DISK_file_close (fh);
@@ -392,7 +427,7 @@ make_reverse_hostname (const void *ip,
*
* @param record information to transmit
* @param record_type requested record type from client
- * @param request_id to which request are we responding
+ * @param client_request_id to which request are we responding
* @param client where to send @a record
* @return #GNUNET_YES if we sent a reply,
* #GNUNET_NO if the record type is not understood or
@@ -401,7 +436,7 @@ make_reverse_hostname (const void *ip,
static int
send_reply (struct GNUNET_DNSPARSER_Record *record,
uint16_t record_type,
- uint16_t request_id,
+ uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client)
{
struct GNUNET_RESOLVER_ResponseMessage *msg;
@@ -446,7 +481,7 @@ send_reply (struct GNUNET_DNSPARSER_Record *record,
env = GNUNET_MQ_msg_extra (msg,
payload_len,
GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE);
- msg->id = request_id;
+ msg->client_id = client_request_id;
GNUNET_memcpy (&msg[1],
payload,
payload_len);
@@ -458,13 +493,13 @@ send_reply (struct GNUNET_DNSPARSER_Record *record,
/**
* Send message to @a client that we transmitted all
- * responses for @a request_id
+ * responses for @a client_request_id
*
- * @param request_id to which request are we responding
+ * @param client_request_id to which request are we responding
* @param client where to send @a record
*/
static void
-send_end_msg (uint16_t request_id,
+send_end_msg (uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client)
{
struct GNUNET_RESOLVER_ResponseMessage *msg;
@@ -474,7 +509,7 @@ send_end_msg (uint16_t request_id,
"Sending END message\n");
env = GNUNET_MQ_msg (msg,
GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE);
- msg->id = request_id;
+ msg->client_id = client_request_id;
GNUNET_MQ_send (GNUNET_SERVICE_client_get_mq (client),
env);
}
@@ -518,13 +553,13 @@ remove_expired (struct ResolveCache *rc)
*
* @param hostname DNS name to resolve
* @param record_type desired record type
- * @param request_id client's request ID
+ * @param client_request_id client's request ID
* @param client who should get the result?
*/
static void
process_get (const char *hostname,
uint16_t record_type,
- uint16_t request_id,
+ uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client);
@@ -536,13 +571,13 @@ process_get (const char *hostname,
*
* @param hostname what hostname was to be resolved
* @param record_type what type of record was requested
- * @param request_id unique identification of the client's request
+ * @param client_request_id unique identification of the client's request
* @param client handle to the client making the request (for sending the
reply)
*/
static int
try_cache (const char *hostname,
uint16_t record_type,
- uint16_t request_id,
+ uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client)
{
struct ResolveCache *pos;
@@ -595,18 +630,18 @@ try_cache (const char *hostname,
process_get (hostname,
record_type,
- request_id,
+ client_request_id,
client);
return GNUNET_YES; /* counts as a cache "hit" */
}
found |= send_reply (rle->record,
record_type,
- request_id,
+ client_request_id,
client);
}
if (GNUNET_NO == found)
return GNUNET_NO; /* had records, but none matched! */
- send_end_msg (request_id,
+ send_end_msg (client_request_id,
client);
return GNUNET_YES;
}
@@ -693,14 +728,14 @@ handle_resolve_result (void *cls,
GNUNET_DNSPARSER_free_packet (parsed);
return;
}
- if (0 == parsed->num_answers)
+ if (0 == parsed->num_answers + parsed->num_authority_records +
parsed->num_additional_records)
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"DNS reply (hostname %s, request ID %u) contains no answers\n",
al->hostname,
- al->request_id);
+ (unsigned int) al->client_request_id);
GNUNET_DNSPARSER_free_packet (parsed);
- send_end_msg (al->request_id,
+ send_end_msg (al->client_request_id,
al->client);
free_active_lookup (al);
return;
@@ -712,7 +747,7 @@ handle_resolve_result (void *cls,
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"Got reply for hostname %s and request ID %u\n",
al->hostname,
- al->request_id);
+ (unsigned int) al->client_request_id);
/* add to cache */
for (unsigned int i = 0; i != parsed->num_answers; i++)
{
@@ -740,6 +775,58 @@ handle_resolve_result (void *cls,
rc->records_tail,
rle);
}
+ for (unsigned int i = 0; i != parsed->num_authority_records; i++)
+ {
+ struct GNUNET_DNSPARSER_Record *record = &parsed->authority_records[i];
+ struct RecordListEntry *rle;
+
+ for (rc = cache_head; NULL != rc; rc = rc->next)
+ if (0 == strcasecmp (rc->hostname,
+ record->name))
+ break;
+ if (NULL == rc)
+ {
+ rc = GNUNET_new (struct ResolveCache);
+ rc->hostname = GNUNET_strdup (record->name);
+ GNUNET_CONTAINER_DLL_insert (cache_head,
+ cache_tail,
+ rc);
+ cache_size++;
+ }
+ /* TODO: ought to check first if we have this exact record
+ already in the cache! */
+ rle = GNUNET_new (struct RecordListEntry);
+ rle->record = GNUNET_DNSPARSER_duplicate_record (record);
+ GNUNET_CONTAINER_DLL_insert (rc->records_head,
+ rc->records_tail,
+ rle);
+ }
+ for (unsigned int i = 0; i != parsed->num_additional_records; i++)
+ {
+ struct GNUNET_DNSPARSER_Record *record = &parsed->additional_records[i];
+ struct RecordListEntry *rle;
+
+ for (rc = cache_head; NULL != rc; rc = rc->next)
+ if (0 == strcasecmp (rc->hostname,
+ record->name))
+ break;
+ if (NULL == rc)
+ {
+ rc = GNUNET_new (struct ResolveCache);
+ rc->hostname = GNUNET_strdup (record->name);
+ GNUNET_CONTAINER_DLL_insert (cache_head,
+ cache_tail,
+ rc);
+ cache_size++;
+ }
+ /* TODO: ought to check first if we have this exact record
+ already in the cache! */
+ rle = GNUNET_new (struct RecordListEntry);
+ rle->record = GNUNET_DNSPARSER_duplicate_record (record);
+ GNUNET_CONTAINER_DLL_insert (rc->records_head,
+ rc->records_tail,
+ rle);
+ }
/* see if we need to do the 2nd request for AAAA records */
if ( (GNUNET_DNSPARSER_TYPE_ALL == al->record_type) &&
(GNUNET_NO == al->did_aaaa) )
@@ -774,11 +861,13 @@ handle_resolve_result (void *cls,
if (GNUNET_NO ==
try_cache (al->hostname,
al->record_type,
- al->request_id,
+ al->client_request_id,
al->client))
/* cache failed, tell client we could not get an answer */
- send_end_msg (al->request_id,
+ {
+ send_end_msg (al->client_request_id,
al->client);
+ }
free_active_lookup (al);
GNUNET_DNSPARSER_free_packet (parsed);
}
@@ -798,7 +887,7 @@ handle_resolve_timeout (void *cls)
al->timeout_task = NULL;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
"DNS lookup timeout!\n");
- send_end_msg (al->request_id,
+ send_end_msg (al->client_request_id,
al->client);
free_active_lookup (al);
}
@@ -810,14 +899,14 @@ handle_resolve_timeout (void *cls)
*
* @param hostname DNS name to resolve
* @param record_type record type to locate
- * @param request_id client request ID
+ * @param client_request_id client request ID
* @param client handle to the client
* @return #GNUNET_OK if the DNS query is now pending
*/
static int
resolve_and_cache (const char* hostname,
uint16_t record_type,
- uint16_t request_id,
+ uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client)
{
char *packet_buf;
@@ -827,7 +916,8 @@ resolve_and_cache (const char* hostname,
uint16_t type;
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "resolve_and_cache\n");
+ "resolve_and_cache `%s'\n",
+ hostname);
dns_id = (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
UINT16_MAX);
@@ -851,7 +941,7 @@ resolve_and_cache (const char* hostname,
al = GNUNET_new (struct ActiveLookup);
al->hostname = GNUNET_strdup (hostname);
al->record_type = record_type;
- al->request_id = request_id;
+ al->client_request_id = client_request_id;
al->dns_id = dns_id;
al->client = client;
al->timeout_task = GNUNET_SCHEDULER_add_delayed (DNS_TIMEOUT,
@@ -868,42 +958,68 @@ resolve_and_cache (const char* hostname,
lookup_tail,
al);
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "Resolving %s, request_id = %u, dns_id = %u\n",
+ "Resolving %s, client_request_id = %u, dns_id = %u\n",
hostname,
- (unsigned int) request_id,
+ (unsigned int) client_request_id,
(unsigned int) dns_id);
return GNUNET_OK;
}
/**
- * Process DNS request for @a hostname with request ID @a request_id
+ * Process DNS request for @a hostname with request ID @a client_request_id
* from @a client demanding records of type @a record_type.
*
* @param hostname DNS name to resolve
* @param record_type desired record type
- * @param request_id client's request ID
+ * @param client_request_id client's request ID
* @param client who should get the result?
*/
static void
process_get (const char *hostname,
uint16_t record_type,
- uint16_t request_id,
+ uint32_t client_request_id,
struct GNUNET_SERVICE_Client *client)
{
+ char fqdn[255];
+
+ if ( (NULL != my_domain) &&
+ (NULL == strchr (hostname,
+ (unsigned char) '.')) &&
+ (strlen (hostname) + strlen (my_domain) <= 253) )
+ {
+ GNUNET_snprintf (fqdn,
+ sizeof (fqdn),
+ "%s.%s",
+ hostname,
+ my_domain);
+ }
+ else if (strlen (hostname) < 255)
+ {
+ GNUNET_snprintf (fqdn,
+ sizeof (fqdn),
+ "%s",
+ hostname);
+ }
+ else
+ {
+ GNUNET_break (0);
+ GNUNET_SERVICE_client_drop (client);
+ return;
+ }
if (GNUNET_NO ==
- try_cache (hostname,
+ try_cache (fqdn,
record_type,
- request_id,
+ client_request_id,
client))
{
if (GNUNET_OK !=
- resolve_and_cache (hostname,
+ resolve_and_cache (fqdn,
record_type,
- request_id,
+ client_request_id,
client))
{
- send_end_msg (request_id,
+ send_end_msg (client_request_id,
client);
}
}
@@ -979,12 +1095,13 @@ handle_get (void *cls,
struct GNUNET_SERVICE_Client *client = cls;
int direction;
int af;
- uint16_t request_id;
+ uint32_t client_request_id;
char *hostname;
direction = ntohl (msg->direction);
af = ntohl (msg->af);
- request_id = ntohs (msg->id);
+ client_request_id = msg->client_id;
+ GNUNET_SERVICE_client_continue (client);
if (GNUNET_NO == direction)
{
/* IP from hostname */
@@ -995,7 +1112,7 @@ handle_get (void *cls,
{
process_get (hostname,
GNUNET_DNSPARSER_TYPE_ALL,
- request_id,
+ client_request_id,
client);
break;
}
@@ -1003,7 +1120,7 @@ handle_get (void *cls,
{
process_get (hostname,
GNUNET_DNSPARSER_TYPE_A,
- request_id,
+ client_request_id,
client);
break;
}
@@ -1011,15 +1128,15 @@ handle_get (void *cls,
{
process_get (hostname,
GNUNET_DNSPARSER_TYPE_AAAA,
- request_id,
+ client_request_id,
client);
break;
}
default:
{
GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
- "got invalid af: %d\n",
- af);
+ "got invalid af: %d\n",
+ af);
GNUNET_assert (0);
}
}
@@ -1031,11 +1148,10 @@ handle_get (void *cls,
af);
process_get (hostname,
GNUNET_DNSPARSER_TYPE_PTR,
- request_id,
+ client_request_id,
client);
}
GNUNET_free_non_null (hostname);
- GNUNET_SERVICE_client_continue (client);
}
diff --git a/src/util/resolver.h b/src/util/resolver.h
index 07851d052..54a1cf5fd 100644
--- a/src/util/resolver.h
+++ b/src/util/resolver.h
@@ -41,7 +41,7 @@ GNUNET_NETWORK_STRUCT_BEGIN
struct GNUNET_RESOLVER_GetMessage
{
/**
- * Type: GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST
+ * Type: #GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST
*/
struct GNUNET_MessageHeader header;
@@ -60,7 +60,7 @@ struct GNUNET_RESOLVER_GetMessage
* identifies the request and is contained in the response message. The
* client has to match response to request by this identifier.
*/
- uint16_t id GNUNET_PACKED;
+ uint32_t client_id GNUNET_PACKED;
/* followed by 0-terminated string for A/AAAA-lookup or
by 'struct in_addr' / 'struct in6_addr' for reverse lookup */
@@ -71,15 +71,15 @@ struct GNUNET_RESOLVER_GetMessage
struct GNUNET_RESOLVER_ResponseMessage
{
/**
- * Type: GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE
+ * Type: #GNUNET_MESSAGE_TYPE_RESOLVER_RESPONSE
*/
struct GNUNET_MessageHeader header;
/**
- * identifies the request this message responds to. The client
- * has to match response to request by this identifier.
- */
- uint16_t id GNUNET_PACKED;
+ * identifies the request this message responds to. The client
+ * has to match response to request by this identifier.
+ */
+ uint32_t client_id GNUNET_PACKED;
/* followed by 0-terminated string for response to a reverse lookup
* or by 'struct in_addr' / 'struct in6_addr' for response to
diff --git a/src/util/resolver_api.c b/src/util/resolver_api.c
index 8a054327b..871eeb4bf 100644
--- a/src/util/resolver_api.c
+++ b/src/util/resolver_api.c
@@ -68,10 +68,10 @@ static struct GNUNET_RESOLVER_RequestHandle *req_head;
*/
static struct GNUNET_RESOLVER_RequestHandle *req_tail;
-///**
-// * ID of the last request we sent to the service
-// */
-//static uint16_t last_request_id;
+/**
+ * ID of the last request we sent to the service
+ */
+static uint32_t last_request_id;
/**
* How long should we wait to reconnect?
@@ -445,7 +445,7 @@ process_requests ()
GNUNET_MESSAGE_TYPE_RESOLVER_REQUEST);
msg->direction = htonl (rh->direction);
msg->af = htonl (rh->af);
- msg->id = htons (rh->id);
+ msg->client_id = rh->id;
GNUNET_memcpy (&msg[1],
&rh[1],
rh->data_len);
@@ -491,11 +491,11 @@ handle_response (void *cls,
struct GNUNET_RESOLVER_RequestHandle *rh = req_head;
uint16_t size;
char *nret;
- uint16_t request_id = msg->id;
+ uint32_t client_request_id = msg->client_id;
for (; rh != NULL; rh = rh->next)
{
- if (rh->id == request_id)
+ if (rh->id == client_request_id)
break;
}
@@ -911,14 +911,6 @@ handle_lookup_timeout (void *cls)
}
-static uint16_t
-get_request_id ()
-{
- return (uint16_t) GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_NONCE,
- UINT16_MAX);
-}
-
-
/**
* Convert a string to one or more IP addresses.
*
@@ -953,8 +945,7 @@ GNUNET_RESOLVER_ip_get (const char *hostname,
hostname);
rh = GNUNET_malloc (sizeof (struct GNUNET_RESOLVER_RequestHandle) + slen);
rh->af = af;
- //rh->id = ++last_request_id;
- rh->id = get_request_id ();
+ rh->id = ++last_request_id;
rh->addr_callback = callback;
rh->cls = callback_cls;
GNUNET_memcpy (&rh[1],
@@ -1101,8 +1092,7 @@ GNUNET_RESOLVER_hostname_get (const struct sockaddr *sa,
rh->name_callback = callback;
rh->cls = cls;
rh->af = sa->sa_family;
- //rh->id = ++last_request_id;
- rh->id = get_request_id ();
+ rh->id = ++last_request_id;
rh->timeout = GNUNET_TIME_relative_to_absolute (timeout);
GNUNET_memcpy (&rh[1],
ip,
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- [GNUnet-SVN] [gnunet] branch master updated: use unique 32-bit IDs for DNS requests to avoid random confusions, handle additional and authoritative records as well,
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