[tor-commits] [tor/master] dos: Move concurrent count into conn_stats object
ahf at torproject.org
ahf at torproject.org
Mon Feb 22 21:03:05 UTC 2021
commit 99703eaca0f575e4739523ca815cf55329d16024
Author: David Goulet <dgoulet at torproject.org>
Date: Tue Jan 26 11:57:58 2021 -0500
dos: Move concurrent count into conn_stats object
No behavior change except for logging. This is so the connection related
statistics are in the right object.
Related to #40253
Signed-off-by: David Goulet <dgoulet at torproject.org>
---
src/core/or/dos.c | 61 +++++++++++++++++++++++++++++++++++------------------
src/core/or/dos.h | 8 +++----
src/test/test_dos.c | 4 ++--
3 files changed, 46 insertions(+), 27 deletions(-)
diff --git a/src/core/or/dos.c b/src/core/or/dos.c
index 8b3dccc871..0169a631c2 100644
--- a/src/core/or/dos.c
+++ b/src/core/or/dos.c
@@ -399,7 +399,7 @@ cc_has_exhausted_circuits(const dos_client_stats_t *stats)
{
tor_assert(stats);
return stats->cc_stats.circuit_bucket == 0 &&
- stats->concurrent_count >= dos_cc_min_concurrent_conn;
+ stats->conn_stats.concurrent_count >= dos_cc_min_concurrent_conn;
}
/* Mark client address by setting a timestamp in the stats object which tells
@@ -491,11 +491,17 @@ conn_consensus_has_changed(const networkstatus_t *ns)
/** Called when a new client connection has arrived. The following will update
* the client connection statistics.
*
+ * The addr is used for logging purposes only.
+ *
* If the connect counter reaches its limit, it is marked. */
static void
-conn_update_on_connect(conn_client_stats_t *stats)
+conn_update_on_connect(conn_client_stats_t *stats, const tor_addr_t *addr)
{
tor_assert(stats);
+ tor_assert(addr);
+
+ /* Update concurrent count for this new connect. */
+ stats->concurrent_count++;
/* Refill connect connection count. */
token_bucket_ctr_refill(&stats->connect_count, (uint32_t) approx_time());
@@ -512,6 +518,31 @@ conn_update_on_connect(conn_client_stats_t *stats)
stats->marked_until_ts == 0) {
conn_mark_client(stats);
}
+
+ log_debug(LD_DOS, "Client address %s has now %u concurrent connections. "
+ "Remaining %lu/sec connections are allowed.",
+ fmt_addr(addr), stats->concurrent_count,
+ token_bucket_ctr_get(&stats->connect_count));
+}
+
+/** Called when a client connection is closed. The following will update
+ * the client connection statistics.
+ *
+ * The addr is used for logging purposes only. */
+static void
+conn_update_on_close(conn_client_stats_t *stats, const tor_addr_t *addr)
+{
+ /* Extra super duper safety. Going below 0 means an underflow which could
+ * lead to most likely a false positive. In theory, this should never happen
+ * but lets be extra safe. */
+ if (BUG(stats->concurrent_count == 0)) {
+ return;
+ }
+
+ stats->concurrent_count--;
+ log_debug(LD_DOS, "Client address %s has lost a connection. Concurrent "
+ "connections are now at %u",
+ fmt_addr(addr), stats->concurrent_count);
}
/* General private API */
@@ -651,7 +682,8 @@ dos_conn_addr_get_defense_type(const tor_addr_t *addr)
/* Need to be above the maximum concurrent connection count to trigger a
* defense. */
- if (entry->dos_stats.concurrent_count > dos_conn_max_concurrent_count) {
+ if (entry->dos_stats.conn_stats.concurrent_count >
+ dos_conn_max_concurrent_count) {
conn_num_addr_rejected++;
return dos_conn_defense_type;
}
@@ -676,7 +708,7 @@ dos_geoip_entry_about_to_free(const clientmap_entry_t *geoip_ent)
/* The count is down to 0 meaning no connections right now, we can safely
* clear the geoip entry from the cache. */
- if (geoip_ent->dos_stats.concurrent_count == 0) {
+ if (geoip_ent->dos_stats.conn_stats.concurrent_count == 0) {
goto end;
}
@@ -831,13 +863,10 @@ dos_new_client_conn(or_connection_t *or_conn, const char *transport_name)
}
/* Update stats from this new connect. */
- conn_update_on_connect(&entry->dos_stats.conn_stats);
+ conn_update_on_connect(&entry->dos_stats.conn_stats,
+ &TO_CONN(or_conn)->addr);
- entry->dos_stats.concurrent_count++;
or_conn->tracked_for_dos_mitigation = 1;
- log_debug(LD_DOS, "Client address %s has now %u concurrent connections.",
- fmt_addr(&TO_CONN(or_conn)->addr),
- entry->dos_stats.concurrent_count);
end:
return;
@@ -867,18 +896,8 @@ dos_close_client_conn(const or_connection_t *or_conn)
goto end;
}
- /* Extra super duper safety. Going below 0 means an underflow which could
- * lead to most likely a false positive. In theory, this should never happen
- * but lets be extra safe. */
- if (BUG(entry->dos_stats.concurrent_count == 0)) {
- goto end;
- }
-
- entry->dos_stats.concurrent_count--;
- log_debug(LD_DOS, "Client address %s has lost a connection. Concurrent "
- "connections are now at %u",
- fmt_addr(&TO_CONN(or_conn)->addr),
- entry->dos_stats.concurrent_count);
+ /* Update stats from this new close. */
+ conn_update_on_close(&entry->dos_stats.conn_stats, &TO_CONN(or_conn)->addr);
end:
return;
diff --git a/src/core/or/dos.h b/src/core/or/dos.h
index 9dba63531b..cadabdb2c9 100644
--- a/src/core/or/dos.h
+++ b/src/core/or/dos.h
@@ -34,6 +34,10 @@ typedef struct cc_client_stats_t {
/* Structure that keeps stats of client connection per-IP. */
typedef struct conn_client_stats_t {
+ /* Concurrent connection count from the specific address. 2^32 - 1 is most
+ * likely way too big for the amount of allowed file descriptors. */
+ uint32_t concurrent_count;
+
/* Connect count from the specific address. We use a token bucket here to
* track the rate and burst of connections from the same IP address.*/
token_bucket_ctr_t connect_count;
@@ -48,10 +52,6 @@ typedef struct conn_client_stats_t {
* per-IP client DoS mitigation. Because it is per-IP, it is used in the geoip
* clientmap_entry_t object. */
typedef struct dos_client_stats_t {
- /* Concurrent connection count from the specific address. 2^32 is most
- * likely way too big for the amount of allowed file descriptors. */
- uint32_t concurrent_count;
-
/* Client connection statistics. */
conn_client_stats_t conn_stats;
diff --git a/src/test/test_dos.c b/src/test/test_dos.c
index 850bbef59b..cbebecb030 100644
--- a/src/test/test_dos.c
+++ b/src/test/test_dos.c
@@ -470,7 +470,7 @@ test_known_relay(void *arg)
GEOIP_CLIENT_CONNECT);
tt_assert(entry);
/* We should have a count of 0. */
- tt_uint_op(entry->dos_stats.concurrent_count, OP_EQ, 0);
+ tt_uint_op(entry->dos_stats.conn_stats.concurrent_count, OP_EQ, 0);
/* To make sure that his is working properly, make a unknown client
* connection and see if we do get it. */
@@ -483,7 +483,7 @@ test_known_relay(void *arg)
GEOIP_CLIENT_CONNECT);
tt_assert(entry);
/* We should have a count of 2. */
- tt_uint_op(entry->dos_stats.concurrent_count, OP_EQ, 2);
+ tt_uint_op(entry->dos_stats.conn_stats.concurrent_count, OP_EQ, 2);
done:
routerstatus_free(rs); routerinfo_free(ri); microdesc_free(md);
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