commit 14b0bba06e65a1dfca6a2f15f3016cb36409183f Author: teor teor2345@gmail.com Date: Wed Nov 8 14:09:50 2017 +1100

Use node counts in networks with all zero-bandwidths

When calculating the fraction of nodes that have descriptors, and all all nodes in the network have zero bandwidths, count the number of nodes instead.

Fixes bug 23318; bugfix on 0.2.4.10-alpha. --- changes/bug23318 | 4 ++++ src/or/routerlist.c | 28 ++++++++++++++++++++-------- 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/changes/bug23318 b/changes/bug23318 index 32c85eb19..7fcb8d448 100644 --- a/changes/bug23318 +++ b/changes/bug23318 @@ -5,3 +5,7 @@ integer. This had the biggest effect when a relay's weight adjustments should have given it weight 0, but it got weight 1 instead. Fixes bug 23318; bugfix on 0.2.4.3-alpha. + - When calculating the fraction of nodes that have descriptors, and all + all nodes in the network have zero bandwidths, count the number of nodes + instead. + Fixes bug 23318; bugfix on 0.2.4.10-alpha. diff --git a/src/or/routerlist.c b/src/or/routerlist.c index faf2eeda5..d6347c49f 100644 --- a/src/or/routerlist.c +++ b/src/or/routerlist.c @@ -149,7 +149,8 @@ typedef struct cert_list_t cert_list_t; /* static function prototypes */ static int compute_weighted_bandwidths(const smartlist_t *sl, bandwidth_weight_rule_t rule, - double **bandwidths_out); + double **bandwidths_out, + double *total_bandwidth_out); static const routerstatus_t *router_pick_trusteddirserver_impl( const smartlist_t *sourcelist, dirinfo_type_t auth, int flags, int *n_busy_out); @@ -2513,7 +2514,7 @@ smartlist_choose_node_by_bandwidth_weights(const smartlist_t *sl, double *bandwidths_dbl=NULL; uint64_t *bandwidths_u64=NULL;

- if (compute_weighted_bandwidths(sl, rule, &bandwidths_dbl) < 0) + if (compute_weighted_bandwidths(sl, rule, &bandwidths_dbl, NULL) < 0) return NULL;

bandwidths_u64 = tor_calloc(smartlist_len(sl), sizeof(uint64_t)); @@ -2533,11 +2534,14 @@ smartlist_choose_node_by_bandwidth_weights(const smartlist_t *sl, * smartlist_choose_node_by_bandwidth_weights, compute weighted bandwidth * values for each node and store them in a freshly allocated * *<b>bandwidths_out</b> of the same length as <b>sl</b>, and holding results - * as doubles. Return 0 on success, -1 on failure. */ + * as doubles. If <b>total_bandwidth_out</b> is non-NULL, set it to the total + * of all the bandwidths. + * Return 0 on success, -1 on failure. */ static int compute_weighted_bandwidths(const smartlist_t *sl, bandwidth_weight_rule_t rule, - double **bandwidths_out) + double **bandwidths_out, + double *total_bandwidth_out) { int64_t weight_scale; double Wg = -1, Wm = -1, We = -1, Wd = -1; @@ -2545,6 +2549,7 @@ compute_weighted_bandwidths(const smartlist_t *sl, uint64_t weighted_bw = 0; guardfraction_bandwidth_t guardfraction_bw; double *bandwidths; + double total_bandwidth = 0.0;

/* Can't choose exit and guard at same time */ tor_assert(rule == NO_WEIGHTING || @@ -2553,6 +2558,10 @@ compute_weighted_bandwidths(const smartlist_t *sl, rule == WEIGHT_FOR_MID || rule == WEIGHT_FOR_DIR);

+ if (total_bandwidth_out) { + *total_bandwidth_out = 0.0; + } + if (smartlist_len(sl) == 0) { log_info(LD_CIRC, "Empty routerlist passed in to consensus weight node " @@ -2714,6 +2723,7 @@ compute_weighted_bandwidths(const smartlist_t *sl, }

bandwidths[node_sl_idx] = final_weight; + total_bandwidth += final_weight; } SMARTLIST_FOREACH_END(node);

log_debug(LD_CIRC, "Generated weighted bandwidths for rule %s based " @@ -2724,6 +2734,10 @@ compute_weighted_bandwidths(const smartlist_t *sl,

*bandwidths_out = bandwidths;

+ if (total_bandwidth_out) { + *total_bandwidth_out = total_bandwidth; + } + return 0; }

@@ -2740,7 +2754,8 @@ frac_nodes_with_descriptors(const smartlist_t *sl, if (smartlist_len(sl) == 0) return 0.0;

- if (compute_weighted_bandwidths(sl, rule, &bandwidths) < 0) { + if (compute_weighted_bandwidths(sl, rule, &bandwidths, &total) < 0 || + total <= 0.0) { int n_with_descs = 0; SMARTLIST_FOREACH(sl, const node_t *, node, { if (node_has_descriptor(node)) @@ -2759,9 +2774,6 @@ frac_nodes_with_descriptors(const smartlist_t *sl,

tor_free(bandwidths);

- if (total < 1.0) - return 0; - return present / total; }