src/feature/hs/hs_metrics.c

   1 /* Copyright (c) 2020-2021, The Tor Project, Inc. */
   2 /* See LICENSE for licensing information */
   3
   4 /**
   5  * @file hs_metrics.c
   6  * @brief Onion service metrics exposed through the MetricsPort
   7  **/
   8
   9 #define HS_METRICS_ENTRY_PRIVATE
  10
  11 #include "orconfig.h"
  12
  13 #include "lib/malloc/malloc.h"
  14 #include "lib/container/smartlist.h"
  15 #include "lib/metrics/metrics_store.h"
  16
  17 #include "feature/hs/hs_metrics.h"
  18 #include "feature/hs/hs_metrics_entry.h"
  19 #include "feature/hs/hs_service.h"
  20
  21 /** Return a static buffer pointer that contains the port as a string.
  22  *
  23  * Subsequent call to this function invalidates the previous buffer. */
  24 static const char *
  25 port_to_str(const uint16_t port)
  26 {
  27   static char buf[8];
  28   tor_snprintf(buf, sizeof(buf), "%u", port);
  29   return buf;
  30 }
  31
  32 /** Initialize a metrics store for the given service.
  33  *
  34  * Essentially, this goes over the base_metrics array and adds them all to the
  35  * store set with their label(s) if any. */
  36 static void
  37 init_store(hs_service_t *service)
  38 {
  39   metrics_store_t *store;
  40
  41   tor_assert(service);
  42
  43   store = service->metrics.store;
  44
  45   for (size_t i = 0; i < base_metrics_size; ++i) {
  46     /* Add entries with port as label. We need one metric line per port. */
  47     if (base_metrics[i].port_as_label && service->config.ports) {
  48       SMARTLIST_FOREACH_BEGIN(service->config.ports,
  49                               const hs_port_config_t *, p) {
  50         metrics_store_entry_t *entry =
  51           metrics_store_add(store, base_metrics[i].type, base_metrics[i].name,
  52                             base_metrics[i].help);
  53
  54         /* Add labels to the entry. */
  55         metrics_store_entry_add_label(entry,
  56                 metrics_format_label("onion", service->onion_address));
  57         metrics_store_entry_add_label(entry,
  58                 metrics_format_label("port", port_to_str(p->virtual_port)));
  59       } SMARTLIST_FOREACH_END(p);
  60     } else {
  61       metrics_store_entry_t *entry =
  62         metrics_store_add(store, base_metrics[i].type, base_metrics[i].name,
  63                           base_metrics[i].help);
  64       metrics_store_entry_add_label(entry,
  65               metrics_format_label("onion", service->onion_address));
  66     }
  67   }
  68 }
  69
  70 /** Update the metrics key entry in the store in the given service. The port,
  71  * if non 0, is used to find the correct metrics entry. The value n is the
  72  * value used to update the entry. */
  73 void
  74 hs_metrics_update_by_service(const hs_metrics_key_t key,
  75                              hs_service_t *service, const uint16_t port,
  76                              int64_t n)
  77 {
  78   tor_assert(service);
  79
  80   /* Get the metrics entry in the store. */
  81   smartlist_t *entries = metrics_store_get_all(service->metrics.store,
  82                                                base_metrics[key].name);
  83   if (BUG(!entries)) {
  84     return;
  85   }
  86
  87   /* We need to find the right metrics entry by finding the port label if any.
  88    *
  89    * XXX: This is not the most optimal due to the string format. Maybe at some
  90    * point turn this into a kvline and a map in a metric entry? */
  91   SMARTLIST_FOREACH_BEGIN(entries, metrics_store_entry_t *, entry) {
  92     if (port == 0 ||
  93         metrics_store_entry_has_label(entry,
  94                       metrics_format_label("port", port_to_str(port)))) {
  95       metrics_store_entry_update(entry, n);
  96       break;
  97     }
  98   } SMARTLIST_FOREACH_END(entry);
  99 }
 100
 101 /** Update the metrics key entry in the store of a service identified by the
 102  * given identity public key. The port, if non 0, is used to find the correct
 103  * metrics entry. The value n is the value used to update the entry.
 104  *
 105  * This is used by callsite that have access to the key but not the service
 106  * object so an extra lookup is done to find the service. */
 107 void
 108 hs_metrics_update_by_ident(const hs_metrics_key_t key,
 109                            const ed25519_public_key_t *ident_pk,
 110                            const uint16_t port, int64_t n)
 111 {
 112   hs_service_t *service;
 113
 114   tor_assert(ident_pk);
 115
 116   service = hs_service_find(ident_pk);
 117   if (!service) {
 118     /* This is possible because an onion service client can end up here due to
 119      * having an identity key onto a connection _to_ an onion service. We
 120      * can't differentiate that from an actual onion service initiated by a
 121      * service and thus the only way to know is to lookup the service. */
 122     return;
 123   }
 124   hs_metrics_update_by_service(key, service, port, n);
 125 }
 126
 127 /** Return a list of all the onion service metrics stores. This is the
 128  * function attached to the .get_metrics() member of the subsys_t. */
 129 const smartlist_t *
 130 hs_metrics_get_stores(void)
 131 {
 132   /* We can't have the caller to free the returned list so keep it static,
 133    * simply update it. */
 134   static smartlist_t *stores_list = NULL;
 135
 136   smartlist_free(stores_list);
 137   stores_list = hs_service_get_metrics_stores();
 138   return stores_list;
 139 }
 140
 141 /** Initialize the metrics store in the given service. */
 142 void
 143 hs_metrics_service_init(hs_service_t *service)
 144 {
 145   tor_assert(service);
 146
 147   /* This function is called when we register a service and so it could either
 148    * be a new service or a service that was just reloaded through a HUP signal
 149    * for instance. Thus, it is possible that the service has already an
 150    * initialized store. If so, just return. */
 151   if (service->metrics.store) {
 152     return;
 153   }
 154
 155   service->metrics.store = metrics_store_new();
 156   init_store(service);
 157 }
 158
 159 /** Free the metrics store in the given service. */
 160 void
 161 hs_metrics_service_free(hs_service_t *service)
 162 {
 163   tor_assert(service);
 164
 165   metrics_store_free(service->metrics.store);
 166 }