Merge branch 'maint-0.4.7'

changes/ticket40194

@@ -0,0 +1,3 @@
+  o Minor feature (relay, metrics):
+    - Add counters to the MetricsPort how many connections, per type, are
+      currently opened and how many were created. Part of ticket 40194.

src/core/mainloop/connection.c

@@ -657,6 +657,9 @@ listener_connection_new(int type, int socket_family)
   listener_connection_t *listener_conn =
     tor_malloc_zero(sizeof(listener_connection_t));
   connection_init(time(NULL), TO_CONN(listener_conn), type, socket_family);
+  /* Listener connections aren't accounted for with note_connection() so do
+   * this explicitly so to count them. */
+  rep_hist_note_conn_opened(false, type);
   return listener_conn;
 }
 
@@ -1158,6 +1161,9 @@ connection_mark_for_close_internal_, (connection_t *conn,
    * the number of seconds since last successful write, so
    * we get our whole 15 seconds */
   conn->timestamp_last_write_allowed = time(NULL);
+
+  /* Note the connection close. */
+  rep_hist_note_conn_closed(conn->from_listener, conn->type);
 }
 
 /** Find each connection that has hold_open_until_flushed set to
@@ -2005,6 +2011,7 @@ connection_handle_listener_read(connection_t *conn, int new_type)
         log_notice(LD_APP,
                    "Denying socks connection from untrusted address %s.",
                    fmt_and_decorate_addr(&addr));
+        rep_hist_note_conn_rejected(new_type);
         tor_close_socket(news);
         return 0;
       }
@@ -2014,6 +2021,7 @@ connection_handle_listener_read(connection_t *conn, int new_type)
       if (dir_policy_permits_address(&addr) == 0) {
         log_notice(LD_DIRSERV,"Denying dir connection from address %s.",
                    fmt_and_decorate_addr(&addr));
+        rep_hist_note_conn_rejected(new_type);
         tor_close_socket(news);
         return 0;
       }
@@ -2022,6 +2030,7 @@ connection_handle_listener_read(connection_t *conn, int new_type)
       /* Assess with the connection DoS mitigation subsystem if this address
        * can open a new connection. */
       if (dos_conn_addr_get_defense_type(&addr) == DOS_CONN_DEFENSE_CLOSE) {
+        rep_hist_note_conn_rejected(new_type);
         tor_close_socket(news);
         return 0;
       }
@@ -2072,6 +2081,9 @@ connection_handle_listener_read(connection_t *conn, int new_type)
     tor_assert(0);
   };
 
+  /* We are receiving this connection. */
+  newconn->from_listener = 1;
+
   if (connection_add(newconn) < 0) { /* no space, forget it */
     connection_free(newconn);
     return 0; /* no need to tear down the parent */
@@ -2083,7 +2095,7 @@ connection_handle_listener_read(connection_t *conn, int new_type)
     return 0;
   }
 
-  note_connection(true /* inbound */, conn->socket_family);
+  note_connection(true /* inbound */, newconn);
 
   return 0;
 }
@@ -2262,7 +2274,7 @@ connection_connect_sockaddr,(connection_t *conn,
     }
   }
 
-  note_connection(false /* outbound */, conn->socket_family);
+  note_connection(false /* outbound */, conn);
 
   /* it succeeded. we're connected. */
   log_fn(inprogress ? LOG_DEBUG : LOG_INFO, LD_NET,

src/core/or/connection_edge.c

@@ -4206,6 +4206,7 @@ connection_exit_connect(edge_connection_t *edge_conn)
     log_info(LD_EXIT,"%s failed exit policy%s. Closing.",
              connection_describe(conn),
              why_failed_exit_policy);
+    rep_hist_note_conn_rejected(conn->type);
     connection_edge_end(edge_conn, END_STREAM_REASON_EXITPOLICY);
     circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
     connection_free(conn);
@@ -4233,6 +4234,7 @@ connection_exit_connect(edge_connection_t *edge_conn)
       nodelist_reentry_contains(&conn->addr, conn->port)) {
     log_info(LD_EXIT, "%s tried to connect back to a known relay address. "
                       "Closing.", connection_describe(conn));
+    rep_hist_note_conn_rejected(conn->type);
     connection_edge_end(edge_conn, END_STREAM_REASON_CONNECTREFUSED);
     circuit_detach_stream(circuit_get_by_edge_conn(edge_conn), edge_conn);
     connection_free(conn);

src/core/or/connection_st.h

@@ -87,6 +87,10 @@ struct connection_t {
   /** True iff we've called connection_close_immediate() on this linked
    * connection. */
   unsigned int linked_conn_is_closed:1;
+  /** True iff this connection was opened from a listener and thus we've
+   * recevied this connection. Else, it means we've initiated an outbound
+   * connection. */
+  unsigned int from_listener:1;
 
   /** CONNECT/SOCKS proxy client handshake state (for outgoing connections). */
   unsigned int proxy_state:4;

src/core/or/status.c

@@ -30,6 +30,7 @@
 #include "app/config/statefile.h"
 #include "feature/hs/hs_stats.h"
 #include "feature/hs/hs_service.h"
+#include "core/or/connection_st.h"
 #include "core/or/dos.h"
 #include "feature/stats/geoip_stats.h"
 
@@ -130,21 +131,23 @@ static unsigned n_outgoing_ipv6;
  * heartbeat message.
  **/
 void
-note_connection(bool inbound, int family)
+note_connection(bool inbound, const connection_t *conn)
 {
-  if (family == AF_INET) {
+  if (conn->socket_family == AF_INET) {
     if (inbound) {
       ++n_incoming_ipv4;
     } else {
       ++n_outgoing_ipv4;
     }
-  } else if (family == AF_INET6) {
+  } else if (conn->socket_family == AF_INET6) {
     if (inbound) {
       ++n_incoming_ipv6;
     } else {
       ++n_outgoing_ipv6;
     }
   }
+
+  rep_hist_note_conn_opened(inbound, conn->type);
 }
 
 /**

src/core/or/status.h

@@ -11,7 +11,7 @@
 
 #include "lib/testsupport/testsupport.h"
 
-void note_connection(bool inbound, int family);
+void note_connection(bool inbound, const connection_t *conn);
 void note_circ_closed_for_unrecognized_cells(time_t n_seconds,
                                              uint32_t n_cells);
 

src/feature/relay/relay_metrics.c

@@ -11,6 +11,7 @@
 #include "orconfig.h"
 
 #include "core/or/or.h"
+#include "core/mainloop/connection.h"
 #include "core/or/relay.h"
 
 #include "lib/malloc/malloc.h"
@@ -24,6 +25,7 @@
 #include <event2/dns.h>
 
 /** Declarations of each fill function for metrics defined in base_metrics. */
+static void fill_connections_values(void);
 static void fill_dns_error_values(void);
 static void fill_dns_query_values(void);
 static void fill_global_bw_limit_values(void);
@@ -87,6 +89,13 @@ static const relay_metrics_entry_t base_metrics[] =
     .help = "Total number of times we ran out of TCP ports",
     .fill_fn = fill_tcp_exhaustion_values,
   },
+  {
+    .key = RELAY_METRICS_NUM_CONNECTIONS,
+    .type = METRICS_TYPE_COUNTER,
+    .name = METRICS_NAME(relay_connections),
+    .help = "Connections metrics of this relay",
+    .fill_fn = fill_connections_values,
+  },
 };
 static const size_t num_base_metrics = ARRAY_LENGTH(base_metrics);
 
@@ -113,6 +122,62 @@ handshake_type_to_str(const uint16_t type)
   }
 }
 
+/** Helper: Fill in single connection metrics output. */
+static void
+fill_single_connection_value(metrics_store_entry_t *sentry,
+                             unsigned int conn_type,
+                             const char* direction,
+                             const char* state,
+                             uint64_t value)
+{
+  metrics_store_entry_add_label(sentry,
+          metrics_format_label("type", conn_type_to_string(conn_type)));
+  metrics_store_entry_add_label(sentry,
+          metrics_format_label("direction", direction));
+  metrics_store_entry_add_label(sentry,
+          metrics_format_label("state", state));
+  metrics_store_entry_update(sentry, value);
+}
+
+/** Fill function for the RELAY_METRICS_NUM_CONNECTIONS metric. */
+static void
+fill_connections_values(void)
+{
+  const relay_metrics_entry_t *rentry =
+    &base_metrics[RELAY_METRICS_NUM_CONNECTIONS];
+
+  for (unsigned int i = CONN_TYPE_MIN_; i < CONN_TYPE_MAX_ ; i++) {
+    /* Type is unused. Ugly but else we clobber the output. */
+    if (i == 10) {
+      continue;
+    }
+    metrics_store_entry_t *sentry =
+      metrics_store_add(the_store, rentry->type, rentry->name, rentry->help);
+    fill_single_connection_value(sentry, i, "initiated", "created",
+                                 rep_hist_get_conn_created(false, i));
+
+    sentry = metrics_store_add(the_store, rentry->type, rentry->name,
+                               rentry->help);
+    fill_single_connection_value(sentry, i, "received", "created",
+                                 rep_hist_get_conn_created(true, i));
+
+    sentry = metrics_store_add(the_store, rentry->type, rentry->name,
+                               rentry->help);
+    fill_single_connection_value(sentry, i, "initiated", "opened",
+                                 rep_hist_get_conn_opened(false, i));
+
+    sentry = metrics_store_add(the_store, rentry->type, rentry->name,
+                               rentry->help);
+    fill_single_connection_value(sentry, i, "received", "opened",
+                                 rep_hist_get_conn_opened(true, i));
+
+    sentry = metrics_store_add(the_store, rentry->type, rentry->name,
+                               rentry->help);
+    fill_single_connection_value(sentry, i, "received", "rejected",
+                                 rep_hist_get_conn_rejected(i));
+  }
+}
+
 /** Fill function for the RELAY_METRICS_NUM_DNS metrics. */
 static void
 fill_tcp_exhaustion_values(void)

src/feature/relay/relay_metrics.h

@@ -29,6 +29,8 @@ typedef enum {
   RELAY_METRICS_NUM_DNS_ERRORS = 5,
   /** Number of TCP exhaustion reached. */
   RELAY_METRICS_NUM_TCP_EXHAUSTION = 6,
+  /** Number of connections. */
+  RELAY_METRICS_NUM_CONNECTIONS = 7,
 } relay_metrics_key_t;
 
 /** The metadata of a relay metric. */

src/feature/stats/rephist.c

@@ -69,6 +69,7 @@
 #define REPHIST_PRIVATE
 #include "core/or/or.h"
 #include "app/config/config.h"
+#include "core/mainloop/connection.h"
 #include "core/or/circuitlist.h"
 #include "core/or/connection_or.h"
 #include "feature/dirauth/authmode.h"
@@ -1638,6 +1639,81 @@ rep_hist_note_exit_stream_opened(uint16_t port)
   log_debug(LD_HIST, "Opened exit stream to port %d", port);
 }
 
+/******* Connections statistics *******/
+
+#define CONN_DIRECTION_INITIATED 0
+#define CONN_DIRECTION_RECEIVED  1
+
+#define CONN_DIRECTION(from_listener) \
+  (from_listener) ? CONN_DIRECTION_RECEIVED : CONN_DIRECTION_INITIATED
+
+/** Number of connections created as in seen per direction per type. */
+static uint64_t conn_num_created[2][CONN_TYPE_MAX_];
+/** Number of connections opened per direction per type. */
+static uint64_t conn_num_opened[2][CONN_TYPE_MAX_];
+/** Number of connections rejected per type. Always inbound. */
+static uint64_t conn_num_rejected[CONN_TYPE_MAX_];
+
+/** Note that a connection has opened of the given type. */
+void
+rep_hist_note_conn_opened(bool from_listener, unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+
+  unsigned int dir = CONN_DIRECTION(from_listener);
+
+  conn_num_created[dir][type]++;
+  conn_num_opened[dir][type]++;
+}
+
+/** Note that a connection has closed of the given type. */
+void
+rep_hist_note_conn_closed(bool from_listener, unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+
+  unsigned int dir = CONN_DIRECTION(from_listener);
+
+  if (conn_num_opened[dir][type] > 0) {
+    conn_num_opened[dir][type]--;
+  }
+}
+
+/** Note that a connection has rejected of the given type. */
+void
+rep_hist_note_conn_rejected(unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+
+  conn_num_rejected[type]++;
+}
+
+/** Return number of created connections of the given type. */
+uint64_t
+rep_hist_get_conn_created(bool from_listener, unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+  unsigned int dir = CONN_DIRECTION(from_listener);
+  return conn_num_created[dir][type];
+}
+
+/** Return number of opened connections of the given type. */
+uint64_t
+rep_hist_get_conn_opened(bool from_listener, unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+  unsigned int dir = CONN_DIRECTION(from_listener);
+  return conn_num_opened[dir][type];
+}
+
+/** Return number of opened connections of the given type. */
+uint64_t
+rep_hist_get_conn_rejected(unsigned int type)
+{
+  tor_assert(type <= CONN_TYPE_MAX_);
+  return conn_num_rejected[type];
+}
+
 /*** cell statistics ***/
 
 /** Start of the current buffer stats interval or 0 if we're not

src/feature/stats/rephist.h

@@ -41,6 +41,13 @@ void rep_hist_note_exit_bytes(uint16_t port, size_t num_written,
                               size_t num_read);
 void rep_hist_note_exit_stream_opened(uint16_t port);
 
+void rep_hist_note_conn_opened(bool initiated, unsigned int type);
+void rep_hist_note_conn_closed(bool initiated, unsigned int type);
+void rep_hist_note_conn_rejected(unsigned int type);
+uint64_t rep_hist_get_conn_created(bool initiated, unsigned int type);
+uint64_t rep_hist_get_conn_opened(bool initiated, unsigned int type);
+uint64_t rep_hist_get_conn_rejected(unsigned int type);
+
 void rep_hist_buffer_stats_init(time_t now);
 void rep_hist_buffer_stats_add_circ(circuit_t *circ,
                                     time_t end_of_interval);