Commit 2efa0567 authored by Roger Dingledine's avatar Roger Dingledine
Browse files

make the "stable" flag in network-status be the median of the uptimes 

of running valid servers. that way the cutoff adapts to the stability
of the network as a whole.


svn:r5693
parent 4868d77a

src/or/dirserv.c

+52 −10
Changes for src/or/dirserv.c: 52 added lines, 10 removed lines.
Original line number Diff line number Diff line
@@ -1220,6 +1220,8 @@ should_generate_v2_networkstatus(void) 
    the_v2_networkstatus_is_dirty + DIR_REGEN_SLACK_TIME < time(NULL);

}



long stable_uptime = 0; /* start at a safe value */



/** Return 1 if <b>router</b> is not suitable for these parameters, else 0.

 * If <b>need_uptime</b> is non-zero, we require a minimum uptime.

 * If <b>need_capacity</b> is non-zero, we require a minimum advertised
@@ -1229,7 +1231,7 @@ static int 
dirserv_thinks_router_is_unreliable(routerinfo_t *router,

                                    int need_uptime, int need_capacity)

{

  if (need_uptime && router->uptime < ROUTER_REQUIRED_MIN_UPTIME)

  if (need_uptime && router->uptime < stable_uptime)

    return 1;

  if (need_capacity &&

      router->bandwidthcapacity < ROUTER_REQUIRED_MIN_BANDWIDTH)
@@ -1237,6 +1239,42 @@ dirserv_thinks_router_is_unreliable(routerinfo_t *router, 
  return 0;

}



static int

_compare_longs(const void **a, const void **b)

{

  long first = **(long **)a, second = **(long **)b;

  if (first < second) return -1;

  if (first > second) return 1;

  return 0;

}



/** Look through the routerlist, and assign the median uptime

 * of running verified servers to stable_uptime. */

void

dirserv_compute_stable_uptime(routerlist_t *rl)

{

  smartlist_t *uptimes = smartlist_create();

  long *up;



  SMARTLIST_FOREACH(rl->routers, routerinfo_t *, ri, {

    if (ri->is_running && ri->is_verified) {

      up = tor_malloc(sizeof(long));

      *up = ri->uptime;

      smartlist_add(uptimes, up);

    }

  });



  smartlist_sort(uptimes, _compare_longs);



  stable_uptime = *(long *)smartlist_get(uptimes,

                                         smartlist_len(uptimes)/2);



  info(LD_DIRSERV, "Uptime cutoff is %ld seconds.", stable_uptime);



  SMARTLIST_FOREACH(uptimes, long *, up, tor_free(up));

  smartlist_free(uptimes);

}



/** For authoritative directories only: replace the contents of

 * <b>the_v2_networkstatus</b> with a newly generated network status

 * object. */
@@ -1325,11 +1363,21 @@ generate_v2_networkstatus(void) 
  outp = status + strlen(status);

  endp = status + len;



  /* precompute this part, since we need it to decide what "stable"

   * means. */

  SMARTLIST_FOREACH(rl->routers, routerinfo_t *, ri, {

    ri->is_running = dirserv_thinks_router_is_reachable(ri, now);

  });



  dirserv_compute_stable_uptime(rl);



  SMARTLIST_FOREACH(rl->routers, routerinfo_t *, ri, {

      int f_exit = router_is_general_exit(ri);

      int f_stable = !dirserv_thinks_router_is_unreliable(ri, 1, 0);

      int f_fast = !dirserv_thinks_router_is_unreliable(ri, 0, 1);

      int f_running;

      int f_stable = ri->is_stable =

                     !dirserv_thinks_router_is_unreliable(ri, 1, 0);

      int f_fast = ri->is_fast =

                   !dirserv_thinks_router_is_unreliable(ri, 0, 1);

      int f_running = ri->is_running; /* computed above */

      int f_authority = router_digest_is_trusted_dir(

                                      ri->cache_info.identity_digest);

      int f_named = naming && ri->is_named;
@@ -1340,12 +1388,6 @@ generate_v2_networkstatus(void) 
        tor_version_as_new_as(ri->platform,"0.1.1.9-alpha");

      char identity64[BASE64_DIGEST_LEN+1];

      char digest64[BASE64_DIGEST_LEN+1];

      if (options->AuthoritativeDir) {

        ri->is_running = dirserv_thinks_router_is_reachable(ri, now);

        ri->is_fast = f_fast;

        ri->is_stable = f_stable;

      }

      f_running = ri->is_running;



      format_iso_time(published, ri->cache_info.published_on);

src/or/or.h

+2 −7
Changes for src/or/or.h: 2 added lines, 7 removed lines.
Original line number Diff line number Diff line
@@ -2244,15 +2244,10 @@ void add_nickname_list_to_smartlist(smartlist_t *sl, const char *list, 
routerinfo_t *routerlist_find_my_routerinfo(void);

int exit_policy_implicitly_allows_local_networks(addr_policy_t *policy,

                                                 int warn);



/** How many seconds a router must be up before we'll use it for

 * reliability-critical node positions.

 */

#define ROUTER_REQUIRED_MIN_UPTIME (24*3600) /* a day */

#define ROUTER_REQUIRED_MIN_BANDWIDTH 10000



routerinfo_t *router_find_exact_exit_enclave(const char *address,

                                             uint16_t port);



#define ROUTER_REQUIRED_MIN_BANDWIDTH 10000

int router_is_unreliable(routerinfo_t *router, int need_uptime,

                         int need_capacity);

routerinfo_t *routerlist_sl_choose_by_bandwidth(smartlist_t *sl);