diff options
Diffstat (limited to 'iterator/iter_utils.c')
| -rw-r--r-- | iterator/iter_utils.c | 123 |
1 files changed, 113 insertions, 10 deletions
diff --git a/iterator/iter_utils.c b/iterator/iter_utils.c index 90c8cf114e332..4ac8efd0d17ac 100644 --- a/iterator/iter_utils.c +++ b/iterator/iter_utils.c @@ -282,10 +282,13 @@ iter_filter_unsuitable(struct iter_env* iter_env, struct module_env* env, static int iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, uint8_t* name, size_t namelen, uint16_t qtype, time_t now, - struct delegpt* dp, int* best_rtt, struct sock_list* blacklist) + struct delegpt* dp, int* best_rtt, struct sock_list* blacklist, + size_t* num_suitable_results) { int got_it = 0; struct delegpt_addr* a; + *num_suitable_results = 0; + if(dp->bogus) return 0; /* NS bogus, all bogus, nothing found */ for(a=dp->result_list; a; a = a->next_result) { @@ -301,11 +304,58 @@ iter_fill_rtt(struct iter_env* iter_env, struct module_env* env, } else if(a->sel_rtt < *best_rtt) { *best_rtt = a->sel_rtt; } + (*num_suitable_results)++; } } return got_it; } +/** compare two rtts, return -1, 0 or 1 */ +static int +rtt_compare(const void* x, const void* y) +{ + if(*(int*)x == *(int*)y) + return 0; + if(*(int*)x > *(int*)y) + return 1; + return -1; +} + +/** get RTT for the Nth fastest server */ +static int +nth_rtt(struct delegpt_addr* result_list, size_t num_results, size_t n) +{ + int rtt_band; + size_t i; + int* rtt_list, *rtt_index; + + if(num_results < 1 || n >= num_results) { + return -1; + } + + rtt_list = calloc(num_results, sizeof(int)); + if(!rtt_list) { + log_err("malloc failure: allocating rtt_list"); + return -1; + } + rtt_index = rtt_list; + + for(i=0; i<num_results && result_list; i++) { + if(result_list->sel_rtt != -1) { + *rtt_index = result_list->sel_rtt; + rtt_index++; + } + result_list=result_list->next_result; + } + qsort(rtt_list, num_results, sizeof(*rtt_list), rtt_compare); + + log_assert(n > 0); + rtt_band = rtt_list[n-1]; + free(rtt_list); + + return rtt_band; +} + /** filter the address list, putting best targets at front, * returns number of best targets (or 0, no suitable targets) */ static int @@ -314,12 +364,13 @@ iter_filter_order(struct iter_env* iter_env, struct module_env* env, struct delegpt* dp, int* selected_rtt, int open_target, struct sock_list* blacklist, time_t prefetch) { - int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND; + int got_num = 0, low_rtt = 0, swap_to_front, rtt_band = RTT_BAND, nth; + size_t num_results; struct delegpt_addr* a, *n, *prev=NULL; /* fillup sel_rtt and find best rtt in the bunch */ got_num = iter_fill_rtt(iter_env, env, name, namelen, qtype, now, dp, - &low_rtt, blacklist); + &low_rtt, blacklist, &num_results); if(got_num == 0) return 0; if(low_rtt >= USEFUL_SERVER_TOP_TIMEOUT && @@ -329,14 +380,19 @@ iter_filter_order(struct iter_env* iter_env, struct module_env* env, return 0 to force the caller to fetch more */ } - if(env->cfg->low_rtt_permil != 0 && prefetch == 0 && - low_rtt < env->cfg->low_rtt && - ub_random_max(env->rnd, 1000) < env->cfg->low_rtt_permil) { + if(env->cfg->fast_server_permil != 0 && prefetch == 0 && + num_results > env->cfg->fast_server_num && + ub_random_max(env->rnd, 1000) < env->cfg->fast_server_permil) { /* the query is not prefetch, but for a downstream client, - * there is a low_rtt (fast) server. We choose that x% of the - * time */ - /* pick rtt numbers from 0..LOWBAND_RTT */ - rtt_band = env->cfg->low_rtt - low_rtt; + * there are more servers available then the fastest N we want + * to choose from. Limit our choice to the fastest servers. */ + nth = nth_rtt(dp->result_list, num_results, + env->cfg->fast_server_num); + if(nth > 0) { + rtt_band = nth - low_rtt; + if(rtt_band > RTT_BAND) + rtt_band = RTT_BAND; + } } got_num = 0; @@ -1210,3 +1266,50 @@ int iter_dp_cangodown(struct query_info* qinfo, struct delegpt* dp) return 0; return 1; } + +int +iter_stub_fwd_no_cache(struct module_qstate *qstate, struct query_info *qinf) +{ + struct iter_hints_stub *stub; + struct delegpt *dp; + + /* Check for stub. */ + stub = hints_lookup_stub(qstate->env->hints, qinf->qname, + qinf->qclass, NULL); + dp = forwards_lookup(qstate->env->fwds, qinf->qname, qinf->qclass); + + /* see if forward or stub is more pertinent */ + if(stub && stub->dp && dp) { + if(dname_strict_subdomain(dp->name, dp->namelabs, + stub->dp->name, stub->dp->namelabs)) { + stub = NULL; /* ignore stub, forward is lower */ + } else { + dp = NULL; /* ignore forward, stub is lower */ + } + } + + /* check stub */ + if (stub != NULL && stub->dp != NULL) { + if(stub->dp->no_cache) { + char qname[255+1]; + char dpname[255+1]; + dname_str(qinf->qname, qname); + dname_str(stub->dp->name, dpname); + verbose(VERB_ALGO, "stub for %s %s has no_cache", qname, dpname); + } + return (stub->dp->no_cache); + } + + /* Check for forward. */ + if (dp) { + if(dp->no_cache) { + char qname[255+1]; + char dpname[255+1]; + dname_str(qinf->qname, qname); + dname_str(dp->name, dpname); + verbose(VERB_ALGO, "forward for %s %s has no_cache", qname, dpname); + } + return (dp->no_cache); + } + return 0; +} |