[sr-dev] git:master:cf105d5a: dispatcher: safety to avoid division by 0 for latency operations

Module: kamailio Branch: master Commit: cf105d5af78963759825f5eaf9feb767c047a49c URL: https://github.com/kamailio/kamailio/commit/cf105d5af78963759825f5eaf9feb76… Author: Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; Committer: Daniel-Constantin Mierla &lt;miconda(a)gmail.com&gt; Date: 2021-04-29T14:47:36+02:00 dispatcher: safety to avoid division by 0 for latency operations --- Modified: src/modules/dispatcher/dispatch.c --- Diff: https://github.com/kamailio/kamailio/commit/cf105d5af78963759825f5eaf9feb76… Patch: https://github.com/kamailio/kamailio/commit/cf105d5af78963759825f5eaf9feb76… --- diff --git a/src/modules/dispatcher/dispatch.c b/src/modules/dispatcher/dispatch.c index 80944e4b05..78ece3fffe 100644 --- a/src/modules/dispatcher/dispatch.c +++ b/src/modules/dispatcher/dispatch.c @@ -2733,7 +2733,8 @@ int ds_mark_dst(struct sip_msg *msg, int state) return (ret == 0) ? 1 : -1; } -void latency_stats_init(ds_latency_stats_t *latency_stats, int latency, int count) { +void latency_stats_init(ds_latency_stats_t *latency_stats, int latency, int count) +{ latency_stats->stdev = 0.0f; latency_stats->m2 = 0.0f; latency_stats->max = latency; @@ -2743,14 +2744,17 @@ void latency_stats_init(ds_latency_stats_t *latency_stats, int latency, int coun latency_stats->count = count; } -static inline void latency_stats_update(ds_latency_stats_t *latency_stats, int latency) { +#define _VOR1(v) ((v)?(v):1) + +static inline void latency_stats_update(ds_latency_stats_t *latency_stats, int latency) +{ int training_count = 10000; /* after 2^21 ~24 days at 1s interval, the average becomes a weighted average */ if (latency_stats->count < 2097152) { latency_stats->count++; } else { /* We adjust the sum of squares used by the oneline algorithm proportionally */ - latency_stats->m2 -= latency_stats->m2/latency_stats->count; + latency_stats->m2 -= latency_stats->m2/_VOR1(latency_stats->count); } if (latency_stats->count == 1) @@ -2771,10 +2775,10 @@ static inline void latency_stats_update(ds_latency_stats_t *latency_stats, int l float delta; float delta2; delta = latency - latency_stats->average; - latency_stats->average += delta/latency_stats->count; + latency_stats->average += delta/_VOR1(latency_stats->count); delta2 = latency - latency_stats->average; latency_stats->m2 += ((double)delta)*delta2; - latency_stats->stdev = sqrt(latency_stats->m2 / (latency_stats->count-1)); + latency_stats->stdev = sqrt(latency_stats->m2 / _VOR1(latency_stats->count-1)); } /* exponentialy weighted moving average */ if (latency_stats->count < 10) { @@ -2793,7 +2797,8 @@ typedef struct congestion_control_state { int apply_rweights; } congestion_control_state_t; -int ds_update_weighted_congestion_control(congestion_control_state_t *cc, int weight, ds_latency_stats_t *latency_stats) +int ds_update_weighted_congestion_control(congestion_control_state_t *cc, + int weight, ds_latency_stats_t *latency_stats) { int active_weight = 0; int congestion_ms = latency_stats->estimate - latency_stats->average; @@ -2894,7 +2899,7 @@ int ds_update_latency(int group, str *address, int code) ds_latency_stats_t *latency_stats = &ds_dest->latency_stats; congestion_ms = latency_stats->estimate - latency_stats->average; /* We multiply by 2^4 to keep enough precision */ - active_weight = (cc.total_congestion_ms << 4) / congestion_ms; + active_weight = (cc.total_congestion_ms << 4) / _VOR1(congestion_ms); if (ds_dest->attrs.rweight != active_weight) { cc.apply_rweights = 1; ds_dest->attrs.rweight = active_weight;