From be527d670c50d6bbac90aec41cd87366e16515e4 Mon Sep 17 00:00:00 2001
From: Joel Grunbaum <joelgrun@gmail.com>
Date: Wed, 01 Jun 2022 10:00:01 +0000
Subject: [PATCH] Added input argument for reliability testing
---
slist.c | 6 +++---
main.c | 20 +++++++++++++-------
2 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/main.c b/main.c
index 9787a55..9ac6e1f 100644
--- a/main.c
+++ b/main.c
@@ -16,7 +16,7 @@
#define NUM_TESTS 10
-int test_dns(void);
+int test_dns(int num_reach_tests);
void* test_server(void* in);
void* print_progress(void* in);
@@ -31,7 +31,8 @@
int main(int argc, char** argv)
{
int option, added_hosts = 0;
- while ((option = getopt(argc, argv, "s:a:t:n:h")) != -1) {
+ int num_reach_tests = 10;
+ while ((option = getopt(argc, argv, "s:a:t:n:r:h")) != -1) {
switch (option) {
case 's': // server to use
add_dns_server(&servers, optarg);
@@ -47,6 +48,9 @@
case 'n': // number of tests to perform
num_tests = atoi(optarg);
break;
+ case 'r': // number of tests for reachability
+ num_reach_tests = atoi(optarg);
+ break;
case '?':
case 'h':
default:
@@ -62,6 +66,7 @@
printf(
"\t-n <number>\tspecify the number of tests to perform on each "
"hostname\n\t\t\tdefaults to 10\n");
+ printf("\t-r <number>\tspecify the number of tests to run for reachability, defaulting to 10. Reachability testing only works when run as root\n");
printf("\t-h\t\tShow this help\n");
free_dns_list(&servers);
free_hosts_list(&hosts);
@@ -78,7 +83,7 @@
add_dns_server(&servers, (char*)DNS_SERVERS[i]);
num_servers++;
}
- test_dns();
+ test_dns(num_reach_tests);
sort_servers(&servers);
print_servers(servers);
free_dns_list(&servers);
@@ -89,13 +94,14 @@
// 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)
+int test_dns(int num_reach_tests)
{
struct dns_list* curr = servers;
int i = 0;
int init_num_servers = num_servers;
pthread_t* threads;
pthread_t progress;
+
// Check each server for reachability, can't be done in parallel as incorrect packets are received
// reachable() requires raw packets, which needs root
if (getuid() == 0) {
@@ -105,13 +111,13 @@
int error_count = 0;
curr->errors = 0;
// retry 10 times for UDP unreliability
- for (int i = 0; i < 10; i++) {
+ for (int i = 0; i < num_reach_tests; i++) {
error_count += (reachable((unsigned char*)buf, curr->server) != 0);
}
/* fprintf(stderr, "ip: %s, ec: %d\n", curr->server, error_count); */
// 30% error rate means unreachable
- if (error_count >= 3) {
- curr->errors = -1;
+ if (error_count >= (num_reach_tests * 3) / 10) {
+ curr->errors = -1 * error_count;
num_servers--;
}
curr = curr->next;
diff --git a/slist.c b/slist.c
index 971685f..b4e7ccf 100644
--- a/slist.c
+++ b/slist.c
@@ -133,7 +133,7 @@
struct dns_list* curr = head;
printf("%-16s | %-11s | %s\n", "Server", "Time", "Errors");
while (curr) {
- if (curr->errors != -1) {
+ if (curr->errors >= 0) {
printf("%-16s | %ld.%09ld | %d\n", curr->server, curr->time.tv_sec,
curr->time.tv_nsec, curr->errors);
}
@@ -141,9 +141,9 @@
}
fflush(stdout);
curr = head;
- if (head->errors == -1) {
+ if (head->errors < 0) {
printf("The following servers were unreachable:\n");
- while (curr && curr->errors == -1) {
+ while (curr && curr->errors < 0) {
printf("%s\n", curr->server);
curr = curr->next;
}
--
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