From 7a2cec3945ba700c674f816d47f49060975b854d Mon Sep 17 00:00:00 2001
From: Joel Grunbaum <joelgrun@gmail.com>
Date: Fri, 23 Oct 2020 05:52:50 +0000
Subject: [PATCH] renamed shadowed variable
---
main.c | 146 ++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 144 insertions(+), 2 deletions(-)
diff --git a/main.c b/main.c
index 1e36b9e..3e263dd 100644
--- a/main.c
+++ b/main.c
@@ -1,7 +1,149 @@
+/**
+ * A basic dns benchmark testing program
+ * Tests servers in parallel so reasonably fast
+ * Tried to only use POSIX functions to ensure cross platform compatibility
+ **/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <time.h>
+#include <pthread.h>
#include "dns.h"
+#include "servers.h"
+#include "slist.h"
+
+#define NUM_TESTS 10
+
+int test_dns(void);
+void *test_server(void *in);
+void *print_progress(void *in);
+
+// All global variables as passing to threads in structs caused corruption
+// Variables are only modified before threads are created and as such are thread-safe
+// tests_done is modified to provide a rough count of number of tests being completed for progress measurement
+int tests_done = 0, num_tests = NUM_TESTS, num_servers = NUM_DNS, num_hosts = 0;
+struct hosts_list *hosts = NULL;
+struct dns_list *servers = NULL;
int main(int argc, char** argv)
{
- resolve("google.com", "1.1.1.1", T_A, 1);
- return 0;
+ int option, added_hosts = 0;
+ while((option = getopt(argc, argv, "s:a:t:n:h")) != -1) {
+ switch (option) {
+ case 's': //server to use
+ add_dns_server(&servers, optarg);
+ num_servers++;
+ break;
+ case 'a': //hostname to search
+ add_hosts_server(&hosts, optarg);
+ added_hosts++;
+ break;
+ case 't': //set number of hosts to test
+ num_hosts = atoi(optarg);
+ break;
+ case 'n': //number of tests to perform
+ num_tests = atoi(optarg);
+ break;
+ case '?':
+ case 'h':
+ default:
+ printf("Usage: %s [options]\n", argv[0]);
+ printf("Options:\n");
+ printf("\t-s <server>\tadd a DNS server to be tested\n");
+ printf("\t-a <hostname>\tadd a hostname to be tested\n");
+ printf("\t-t <number>\tspecify the number of hostnames to be tested, capped at 50 + number manually added\n\t\t\tdefaults to test all available\n");
+ printf("\t-n <number>\tspecify the number of tests to perform on each hostname\n\t\t\tdefaults to 10\n");
+ printf("\t-h\t\tShow this help\n");
+ free_dns_list(&servers);
+ free_hosts_list(&hosts);
+ exit(1);
+ }
+ }
+ if (num_hosts == 0 || num_hosts > NUM_HOSTNAMES+added_hosts) {
+ num_hosts = NUM_HOSTNAMES + added_hosts;
+ }
+ for (int i = added_hosts; i < num_hosts; i++) {
+ add_hosts_server(&hosts, (char*)HOSTNAMES[i-added_hosts]);
+ }
+ for (int i = 0; i < NUM_DNS; i++) {
+ add_dns_server(&servers, (char*)DNS_SERVERS[i]);
+ }
+ test_dns();
+ sort_servers(&servers);
+ print_servers(servers);
+ free_dns_list(&servers);
+ free_hosts_list(&hosts);
+ return 0;
+}
+
+// Test each dns server individually
+// Each test runs in its own thread and results are written to the respective dns_list
+int test_dns(void)
+{
+ struct dns_list *curr = servers;
+ int i = 0;
+ pthread_t *threads = malloc(num_servers*sizeof(pthread_t));
+ pthread_t progress;
+ pthread_create(&progress, NULL, print_progress, NULL);
+ while (curr) {
+ pthread_create(&threads[i], NULL, test_server, (void*)curr);
+ curr = curr->next;
+ i++;
+ }
+ for (int i = 0; i < num_servers; i++) {
+ pthread_join(threads[i], NULL);
+ }
+ pthread_cancel(progress);
+ printf("\r100.00%% done\n");
+ free(threads);
+ return 0;
+}
+
+// Tests an individual dns server with all the hostnames configured
+void *test_server(void *in)
+{
+ unsigned long long avg_nsec = 0;
+ struct dns_list *dns = (struct dns_list *)in;
+ dns->time.tv_sec = 0; dns->time.tv_nsec = 0;
+ for (int i = 0; i < num_tests; i++) {
+ struct hosts_list *curr = hosts;
+ while (curr) {
+ struct timespec run;
+ run.tv_sec = -1; run.tv_nsec = 0;
+ unsigned char buf[65536];
+ for (int j = 0; j < 3 && run.tv_sec == -1; j++) {
+ run = resolve(buf, curr->server, dns->server, T_A);
+ }
+ if (run.tv_sec == -1) //if test has failed 3 times, set time taken to 3s as penalty
+ run.tv_sec = 3;
+ dns->time.tv_sec += run.tv_sec;
+ dns->time.tv_nsec += run.tv_nsec;
+ if (dns->time.tv_nsec >= 1000000000) { //nanoseconds have overflowed into seconds
+ dns->time.tv_sec += 1;
+ dns->time.tv_nsec -= 1000000000;
+ }
+ tests_done++;
+ curr = curr->next;
+ }
+ }
+ avg_nsec = 1000000000*(dns->time.tv_sec%(num_hosts*num_tests))+dns->time.tv_nsec;
+ dns->time.tv_sec = dns->time.tv_sec/(num_hosts*num_tests);
+ dns->time.tv_nsec = avg_nsec/(num_hosts*num_tests);
+ return NULL;
+}
+
+// Prints the progress every 0.1s for an indication of speed
+// tests_done is being written to in parallel, so may be overwritten but serves as a decent estimate of the progress
+void *print_progress(void *in)
+{
+ struct timespec s;
+ s.tv_sec = 0; s.tv_nsec = 100000000;
+ while (1) {
+ printf("\r%.2f%% done", ((float)tests_done)/(num_servers*num_hosts*num_tests) * 100);
+ fflush(stdout);
+ nanosleep(&s, NULL);
+ }
+ return NULL;
}
--
Gitblit v1.10.0