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authorChristian Grothoff <christian@grothoff.org>2015-10-18 12:20:14 +0000
committerChristian Grothoff <christian@grothoff.org>2015-10-18 12:20:14 +0000
commitaed237fb57999eaf6f3d578bc1f081a6a684836f (patch)
treecb91c9f305fd4b533731cbc4ba6f091425470ebe /src/transport/gnunet-service-transport_ats.c
parent96e83adb54d5be78b5a5d2245ddd334096c51c9e (diff)
combing through transport ATS logic, documenting and cleaning code
Diffstat (limited to 'src/transport/gnunet-service-transport_ats.c')
-rw-r--r--src/transport/gnunet-service-transport_ats.c176
1 files changed, 127 insertions, 49 deletions
diff --git a/src/transport/gnunet-service-transport_ats.c b/src/transport/gnunet-service-transport_ats.c
index 8eb829875..c866eadd9 100644
--- a/src/transport/gnunet-service-transport_ats.c
+++ b/src/transport/gnunet-service-transport_ats.c
@@ -18,7 +18,7 @@
Boston, MA 02110-1301, USA.
*/
/**
- * @file transport/gnunet-service-transport_ats.h
+ * @file transport/gnunet-service-transport_ats.c
* @brief interfacing between transport and ATS service
* @author Christian Grothoff
*/
@@ -29,6 +29,9 @@
#include "gnunet-service-transport_plugins.h"
#include "gnunet_ats_service.h"
+/**
+ * Log convenience function.
+ */
#define LOG(kind,...) GNUNET_log_from(kind, "transport-ats", __VA_ARGS__)
@@ -39,7 +42,8 @@ struct AddressInfo
{
/**
- * The address (with peer identity).
+ * The address (with peer identity). Must never change
+ * while this struct is in the #p2a map.
*/
struct GNUNET_HELLO_Address *address;
@@ -100,8 +104,9 @@ static struct GNUNET_CONTAINER_MultiPeerMap *p2a;
*/
static unsigned int num_blocked;
+
/**
- * Closure for #find_ai().
+ * Closure for #find_ai_cb() and #find_ai_no_session_cb().
*/
struct FindClosure
{
@@ -144,7 +149,9 @@ publish_p2a_stat_update ()
/**
- * Find matching address info.
+ * Find matching address info. Both the address and the session
+ * must match; note that expired addresses are still found (as
+ * the session kind-of keeps those alive).
*
* @param cls the `struct FindClosure`
* @param key which peer is this about
@@ -167,15 +174,13 @@ find_ai_cb (void *cls,
fc->ret = ai;
return GNUNET_NO;
}
- GNUNET_assert ( (fc->session != ai->session) ||
- (NULL == ai->session) );
return GNUNET_YES;
}
/**
* Find the address information struct for the
- * given address and session.
+ * given @a address and @a session.
*
* @param address address to look for
* @param session session to match for inbound connections
@@ -253,6 +258,8 @@ find_ai_no_session (const struct GNUNET_HELLO_Address *address)
/**
* Test if ATS knows about this @a address and @a session.
+ * Note that even if the address is expired, we return
+ * #GNUNET_YES if the respective session matches.
*
* @param address the address
* @param session the session
@@ -267,7 +274,8 @@ GST_ats_is_known (const struct GNUNET_HELLO_Address *address,
/**
- * Test if ATS knows about this @a address.
+ * Test if ATS knows about this @a address. Note that
+ * expired addresses do not count.
*
* @param address the address
* @return #GNUNET_YES if @a address is known, #GNUNET_NO if not.
@@ -324,7 +332,8 @@ GST_ats_block_address (const struct GNUNET_HELLO_Address *address,
{
struct AddressInfo *ai;
- ai = find_ai (address, session);
+ ai = find_ai (address,
+ session);
if (NULL == ai)
{
GNUNET_assert (0);
@@ -356,7 +365,14 @@ GST_ats_block_address (const struct GNUNET_HELLO_Address *address,
(GNUNET_NO ==
GNUNET_ATS_address_del_session (ai->ar,
session)) )
+ {
GNUNET_ATS_address_destroy (ai->ar);
+ }
+ /* "ar" has been freed, regardless how the branch
+ above played out: it was either freed in
+ #GNUNET_ATS_address_del_session() because it was
+ incoming, or explicitly in
+ #GNUNET_ATS_address_del_session(). */
ai->ar = NULL;
/* determine when the address should come back to life */
@@ -371,7 +387,7 @@ GST_ats_block_address (const struct GNUNET_HELLO_Address *address,
/**
* Reset address blocking time. Resets the exponential
- * back-off timer for this address to zero. Done when
+ * back-off timer for this address to zero. Called when
* an address was used to create a successful connection.
*
* @param address the address to reset the blocking timer
@@ -396,10 +412,10 @@ GST_ats_block_reset (const struct GNUNET_HELLO_Address *address,
/**
- * Notify ATS about the a new inbound address. We may already
- * know the address (as this is called each time we receive
- * a message from an inbound connection). If the address is
- * indeed new, make it available to ATS.
+ * Notify ATS about a new inbound @a address. The @a address in
+ * combination with the @a session must be new, but this function will
+ * perform a santiy check. If the @a address is indeed new, make it
+ * available to ATS.
*
* @param address the address
* @param session the session
@@ -413,12 +429,13 @@ GST_ats_add_inbound_address (const struct GNUNET_HELLO_Address *address,
struct GNUNET_ATS_AddressRecord *ar;
struct AddressInfo *ai;
- /* valid new address, let ATS know! */
+ /* Sanity checks for a valid inbound address */
if (NULL == address->transport_name)
{
GNUNET_break(0);
return;
}
+ GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
GNUNET_assert (GNUNET_YES ==
GNUNET_HELLO_address_check_option (address,
GNUNET_HELLO_ADDRESS_INFO_INBOUND));
@@ -431,20 +448,18 @@ GST_ats_add_inbound_address (const struct GNUNET_HELLO_Address *address,
GNUNET_break (0);
return;
}
- GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
+ /* Is indeed new, let's tell ATS */
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Notifying ATS about peer `%s''s new inbound address `%s' session %p in network %s\n",
GNUNET_i2s (&address->peer),
- (0 == address->address_length)
- ? "<inbound>"
- : GST_plugins_a2s (address),
+ GST_plugins_a2s (address),
session,
GNUNET_ATS_print_network_type (prop->scope));
ar = GNUNET_ATS_address_add (GST_ats,
address,
session,
prop);
- GNUNET_break (NULL != ar);
+ GNUNET_assert (NULL != ar);
ai = GNUNET_new (struct AddressInfo);
ai->address = GNUNET_HELLO_address_copy (address);
ai->session = session;
@@ -472,7 +487,7 @@ GST_ats_add_address (const struct GNUNET_HELLO_Address *address,
struct GNUNET_ATS_AddressRecord *ar;
struct AddressInfo *ai;
- /* valid new address, let ATS know! */
+ /* validadte address */
if (NULL == address->transport_name)
{
GNUNET_break(0);
@@ -484,17 +499,17 @@ GST_ats_add_address (const struct GNUNET_HELLO_Address *address,
ai = find_ai_no_session (address);
GNUNET_assert (NULL == ai);
GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
+
+ /* address seems sane, let's tell ATS */
LOG (GNUNET_ERROR_TYPE_INFO,
- "Notifying ATS about peer `%s''s new address `%s'\n",
+ "Notifying ATS about peer %s's new address `%s'\n",
GNUNET_i2s (&address->peer),
- (0 == address->address_length)
- ? "<inbound>"
- : GST_plugins_a2s (address));
+ GST_plugins_a2s (address));
ar = GNUNET_ATS_address_add (GST_ats,
address,
NULL,
prop);
- GNUNET_break (NULL != ar);
+ GNUNET_assert (NULL != ar);
ai = GNUNET_new (struct AddressInfo);
ai->address = GNUNET_HELLO_address_copy (address);
ai->ar = ar;
@@ -508,8 +523,10 @@ GST_ats_add_address (const struct GNUNET_HELLO_Address *address,
/**
- * Notify ATS about a new session now existing for the given
- * address.
+ * Notify ATS about a new @a session now existing for the given
+ * @a address. Essentially, an outbound @a address was used
+ * to establish a @a session. It is safe to call this function
+ * repeatedly for the same @a address and @a session pair.
*
* @param address the address
* @param session the session
@@ -523,22 +540,28 @@ GST_ats_new_session (const struct GNUNET_HELLO_Address *address,
ai = find_ai (address, NULL);
if (NULL == ai)
{
- /* We may already be aware of the session, even if some other part
- of the code could not tell if it just created a new session or
- just got one recycled from the plugin; hence, we may be called
- with "new" session even for an "old" session; in that case,
- check that this is the case, but just ignore it. */
+ /* We may simply already be aware of the session, even if some
+ other part of the code could not tell if it just created a new
+ session or just got one recycled from the plugin; hence, we may
+ be called with "new" session even for an "old" session; in that
+ case, check that this is the case, but just ignore it. */
GNUNET_assert (NULL != (find_ai (address, session)));
return;
}
- GNUNET_break (NULL == ai->session);
+ GNUNET_assert (NULL == ai->session);
ai->session = session;
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Telling ATS about new session for peer %s\n",
GNUNET_i2s (&address->peer));
+ /* Note that the address might currently be blocked; we only
+ tell ATS about the session if the address is currently not
+ blocked; otherwise, ATS will be told about the session on
+ unblock. */
if (NULL != ai->ar)
GNUNET_ATS_address_add_session (ai->ar,
session);
+ else
+ GNUNET_assert (NULL != ai->unblock_task);
}
@@ -576,8 +599,12 @@ destroy_ai (struct AddressInfo *ai)
/**
- * Notify ATS that the session (but not the address) of
- * a given address is no longer relevant.
+ * Notify ATS that the @a session (but not the @a address) of
+ * a given @a address is no longer relevant. (The @a session
+ * went down.) This function may be called even if for the
+ * respective outbound address #GST_ats_new_session() was
+ * never called and thus the pair is unknown to ATS. In this
+ * case, the call is simply ignored.
*
* @param address the address
* @param session the session
@@ -604,7 +631,6 @@ GST_ats_del_session (const struct GNUNET_HELLO_Address *address,
GNUNET_break (GNUNET_YES !=
GNUNET_HELLO_address_check_option (address,
GNUNET_HELLO_ADDRESS_INFO_INBOUND));
-
return;
}
GNUNET_assert (session == ai->session);
@@ -619,37 +645,66 @@ GST_ats_del_session (const struct GNUNET_HELLO_Address *address,
session is dead as well, clean up */
if (NULL != ai->ar)
{
- GNUNET_break (GNUNET_YES ==
- GNUNET_ATS_address_del_session (ai->ar,
- session));
+ /* Address expired but not blocked, and thus 'ar' was still
+ live because of the session; deleting just the session
+ will do for an inbound session, but for an outbound we
+ then also need to destroy the address with ATS. */
+ if (GNUNET_NO ==
+ GNUNET_ATS_address_del_session (ai->ar,
+ session))
+ {
+ GNUNET_ATS_address_destroy (ai->ar);
+ }
+ /* "ar" has been freed, regardless how the branch
+ above played out: it was either freed in
+ #GNUNET_ATS_address_del_session() because it was
+ incoming, or explicitly in
+ #GNUNET_ATS_address_del_session(). */
+ ai->ar = NULL;
}
destroy_ai (ai);
return;
}
+
if (NULL == ai->ar)
{
- /* If ATS doesn't know about the address/session, and this was an
- inbound session, so we must forget about the address as well.
- Otherwise, we are done as we have set `ai->session` to NULL
- already. */
+ /* If ATS doesn't know about the address/session, this means
+ this address was blocked. */
if (GNUNET_YES ==
GNUNET_HELLO_address_check_option (address,
GNUNET_HELLO_ADDRESS_INFO_INBOUND))
- GST_ats_expire_address (address);
+ {
+ /* This was a blocked inbound session, which now lost the
+ session. But inbound addresses are by themselves useless,
+ so we must forget about the address as well. */
+ destroy_ai (ai);
+ return;
+ }
+ /* Otherwise, we are done as we have set `ai->session` to NULL
+ already and ATS will simply not be told about the session when
+ the connection is unblocked and the outbound address becomes
+ available again. . */
return;
}
+
+ /* This is the "simple" case where ATS knows about the session and
+ the address is neither blocked nor expired. Delete the session,
+ and if it was inbound, free the address as well. */
if (GNUNET_YES ==
GNUNET_ATS_address_del_session (ai->ar,
session))
{
+ /* This was an inbound address, the session is now gone, so we
+ need to also forget about the address itself. */
ai->ar = NULL;
- GST_ats_expire_address (address);
+ destroy_ai (address);
}
}
/**
- * Notify ATS about DV distance change to an address's.
+ * Notify ATS about DV @a distance change to an @a address.
+ * Does nothing if the @a address is not known to us.
*
* @param address the address
* @param distance new distance value
@@ -662,15 +717,21 @@ GST_ats_update_distance (const struct GNUNET_HELLO_Address *address,
ai = find_ai_no_session (address);
if (NULL == ai)
+ {
+ /* We do not know about this address, do nothing. */
return;
+ }
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Updated distance for peer `%s' to %u\n",
GNUNET_i2s (&address->peer),
distance);
ai->properties.distance = distance;
+ /* Give manipulation its chance to change metrics */
GST_manipulation_manipulate_metrics (address,
ai->session,
&ai->properties);
+ /* Address may be blocked, only give ATS if address is
+ currently active. */
if (NULL != ai->ar)
GNUNET_ATS_address_update (ai->ar,
&ai->properties);
@@ -678,7 +739,8 @@ GST_ats_update_distance (const struct GNUNET_HELLO_Address *address,
/**
- * Notify ATS about property changes to an address's properties.
+ * Notify ATS about @a delay changes to properties of an @a address.
+ * Does nothing if the @a address is not known to us.
*
* @param address the address
* @param delay new delay value
@@ -691,16 +753,22 @@ GST_ats_update_delay (const struct GNUNET_HELLO_Address *address,
ai = find_ai_no_session (address);
if (NULL == ai)
+ {
+ /* We do not know about this address, do nothing. */
return;
+ }
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Updated latency for peer `%s' to %s\n",
GNUNET_i2s (&address->peer),
GNUNET_STRINGS_relative_time_to_string (delay,
GNUNET_YES));
ai->properties.delay = delay;
+ /* Give manipulation its chance to change metrics */
GST_manipulation_manipulate_metrics (address,
ai->session,
&ai->properties);
+ /* Address may be blocked, only give ATS if address is
+ currently active. */
if (NULL != ai->ar)
GNUNET_ATS_address_update (ai->ar,
&ai->properties);
@@ -708,7 +776,8 @@ GST_ats_update_delay (const struct GNUNET_HELLO_Address *address,
/**
- * Notify ATS about utilization changes to an address.
+ * Notify ATS about utilization changes to an @a address.
+ * Does nothing if the @a address is not known to us.
*
* @param address our information about the address
* @param bps_in new utilization inbound
@@ -723,7 +792,10 @@ GST_ats_update_utilization (const struct GNUNET_HELLO_Address *address,
ai = find_ai_no_session (address);
if (NULL == ai)
+ {
+ /* We do not know about this address, do nothing. */
return;
+ }
LOG (GNUNET_ERROR_TYPE_DEBUG,
"Updating utilization for peer `%s' address %s: %u/%u\n",
GNUNET_i2s (&address->peer),
@@ -732,9 +804,12 @@ GST_ats_update_utilization (const struct GNUNET_HELLO_Address *address,
(unsigned int) bps_out);
ai->properties.utilization_in = bps_in;
ai->properties.utilization_out = bps_out;
+ /* Give manipulation its chance to change metrics */
GST_manipulation_manipulate_metrics (address,
ai->session,
&ai->properties);
+ /* Address may be blocked, only give ATS if address is
+ currently active. */
if (NULL != ai->ar)
GNUNET_ATS_address_update (ai->ar,
&ai->properties);
@@ -765,9 +840,12 @@ GST_ats_expire_address (const struct GNUNET_HELLO_Address *address)
}
if (NULL != ai->session)
{
+ /* Got an active session, just remember the expiration
+ and act upon it when the session goes down. */
ai->expired = GNUNET_YES;
return;
}
+ /* Address expired, no session, free resources */
destroy_ai (ai);
}