reduce thread-unsafe use of static variables

- rework ip_ntoa() to avoid use of static variables
- rework sort_client_list() to avoid use of static variables
- move static 'lastdump' into Messenger struct
- rework ID2String() to avoid use of static variables; rename to id_to_string()
- fetch_broadcast_info(): attempt to mitigate risks from concurrent execution
- current_time_monotonic(): attempt to mitigate risks from concurrent execution
- comment on non-thread-safety of unix_time_update

1 files changed, 6 insertions, 4 deletions

diff --git a/testing/DHT_test.c b/testing/DHT_test.c
index 1fbe6def..c42dc053 100644
--- a/testing/DHT_test.c
+++ b/testing/DHT_test.c
@@ -87,16 +87,17 @@ static void print_hardening(Hardening *h)
 static void print_assoc(IPPTsPng *assoc, uint8_t ours)
 {
     IP_Port *ipp = &assoc->ip_port;
-    printf("\nIP: %s Port: %u", ip_ntoa(&ipp->ip), ntohs(ipp->port));
+    char ip_str[IP_NTOA_LEN];
+    printf("\nIP: %s Port: %u", ip_ntoa(&ipp->ip, ip_str, sizeof(ip_str)), ntohs(ipp->port));
     printf("\nTimestamp: %llu", (long long unsigned int) assoc->timestamp);
     printf("\nLast pinged: %llu\n", (long long unsigned int) assoc->last_pinged);
 
     ipp = &assoc->ret_ip_port;
 
     if (ours) {
-        printf("OUR IP: %s Port: %u\n", ip_ntoa(&ipp->ip), ntohs(ipp->port));
+        printf("OUR IP: %s Port: %u\n", ip_ntoa(&ipp->ip, ip_str, sizeof(ip_str)), ntohs(ipp->port));
     } else {
-        printf("RET IP: %s Port: %u\n", ip_ntoa(&ipp->ip), ntohs(ipp->port));
+        printf("RET IP: %s Port: %u\n", ip_ntoa(&ipp->ip, ip_str, sizeof(ip_str)), ntohs(ipp->port));
     }
 
     printf("Timestamp: %llu\n", (long long unsigned int) assoc->ret_timestamp);
@@ -136,7 +137,8 @@ static void print_friendlist(DHT *dht)
         print_client_id(dht->friends_list[k].public_key);
 
         int friendok = DHT_getfriendip(dht, dht->friends_list[k].public_key, &p_ip);
-        printf("\nIP: %s:%u (%d)", ip_ntoa(&p_ip.ip), ntohs(p_ip.port), friendok);
+        char ip_str[IP_NTOA_LEN];
+        printf("\nIP: %s:%u (%d)", ip_ntoa(&p_ip.ip, ip_str, sizeof(ip_str)), ntohs(p_ip.port), friendok);
 
         printf("\nCLIENTS IN LIST:\n\n");