Improve static and const correctness.

- Any non-externally-visible declarations should be `static`.
- Casting away the `const` qualifier from pointers-to-const is
  dangerous. All but one instance of this are now correct. The one
  instance where we can't keep `const` is one where toxav code actually
  writes to a chunk of memory marked as `const`. This code also assumes
  4 byte alignment of data packets. I don't know whether that is a valid
  assumption, but it's likely unportable, and *not* obviously correct.
- Replaced empty parameter lists with `(void)` to avoid passing
  parameters to it. Empty parameter lists are old style declarations for
  unknown number and type of arguments.
- Commented out (as `#if DHT_HARDENING` block) the hardening code that
  was never executed.
- Minor style fix: don't use `default` in enum-switches unless the number
  of enumerators in the default case is very large. In this case, it was
  2, so we want to list them both explicitly to be warned about missing
  one if we add one in the future.
- Removed the only two function declarations from nTox.h and put them
  into nTox.c. They are not used outside and nTox is not a library.

1 files changed, 34 insertions, 32 deletions

diff --git a/auto_tests/dht_test.c b/auto_tests/dht_test.c
index 7aab9573..dd68ffbe 100644
--- a/auto_tests/dht_test.c
+++ b/auto_tests/dht_test.c
@@ -10,6 +10,9 @@
 
 #include "helpers.h"
 
+
+// These tests currently fail.
+#if 0
 #define swap(x,y) do \
    { unsigned char swap_temp[sizeof(x) == sizeof(y) ? (signed)sizeof(x) : -1]; \
      memcpy(swap_temp,&y,sizeof(x)); \
@@ -18,7 +21,7 @@
     } while(0)
 
 
-void mark_bad(IPPTsPng *ipptp)
+static void mark_bad(IPPTsPng *ipptp)
 {
     ipptp->timestamp = unix_time() - 2 * BAD_NODE_TIMEOUT;
     ipptp->hardening.routes_requests_ok = 0;
@@ -26,7 +29,7 @@ void mark_bad(IPPTsPng *ipptp)
     ipptp->hardening.testing_requests = 0;
 }
 
-void mark_possible_bad(IPPTsPng *ipptp)
+static void mark_possible_bad(IPPTsPng *ipptp)
 {
     ipptp->timestamp = unix_time();
     ipptp->hardening.routes_requests_ok = 0;
@@ -34,7 +37,7 @@ void mark_possible_bad(IPPTsPng *ipptp)
     ipptp->hardening.testing_requests = 0;
 }
 
-void mark_good(IPPTsPng *ipptp)
+static void mark_good(IPPTsPng *ipptp)
 {
     ipptp->timestamp = unix_time();
     ipptp->hardening.routes_requests_ok = (HARDENING_ALL_OK >> 0) & 1;
@@ -42,7 +45,7 @@ void mark_good(IPPTsPng *ipptp)
     ipptp->hardening.testing_requests = (HARDENING_ALL_OK >> 2) & 1;
 }
 
-void mark_all_good(Client_data *list, uint32_t length, uint8_t ipv6)
+static void mark_all_good(Client_data *list, uint32_t length, uint8_t ipv6)
 {
     uint32_t i;
 
@@ -57,7 +60,7 @@ void mark_all_good(Client_data *list, uint32_t length, uint8_t ipv6)
 
 /* Returns 1 if public_key has a furthest distance to comp_client_id
    than all public_key's  in the list */
-uint8_t is_furthest(const uint8_t *comp_client_id, Client_data *list, uint32_t length, const uint8_t *public_key)
+static uint8_t is_furthest(const uint8_t *comp_client_id, Client_data *list, uint32_t length, const uint8_t *public_key)
 {
     uint32_t i;
 
@@ -70,7 +73,7 @@ uint8_t is_furthest(const uint8_t *comp_client_id, Client_data *list, uint32_t l
     return 1;
 }
 
-int client_in_list(Client_data *list, uint32_t length, const uint8_t *public_key)
+static int client_in_list(Client_data *list, uint32_t length, const uint8_t *public_key)
 {
     int i;
 
@@ -83,10 +86,10 @@ int client_in_list(Client_data *list, uint32_t length, const uint8_t *public_key
     return -1;
 }
 
-void test_addto_lists_update(DHT            *dht,
-                             Client_data    *list,
-                             uint32_t        length,
-                             IP_Port        *ip_port)
+static void test_addto_lists_update(DHT            *dht,
+                                    Client_data    *list,
+                                    uint32_t        length,
+                                    IP_Port        *ip_port)
 {
     int used, test, test1, test2, found;
     IP_Port test_ipp;
@@ -157,10 +160,10 @@ void test_addto_lists_update(DHT            *dht,
                   "Client IP_Port is incorrect");
 }
 
-void test_addto_lists_bad(DHT            *dht,
-                          Client_data    *list,
-                          uint32_t        length,
-                          IP_Port        *ip_port)
+static void test_addto_lists_bad(DHT            *dht,
+                                 Client_data    *list,
+                                 uint32_t        length,
+                                 IP_Port        *ip_port)
 {
     // check "bad" clients replacement
     int used, test1, test2, test3;
@@ -200,11 +203,11 @@ void test_addto_lists_bad(DHT            *dht,
     ck_assert_msg(client_in_list(list, length, test_id3) >= 0, "Wrong bad client removed");
 }
 
-void test_addto_lists_possible_bad(DHT            *dht,
-                                   Client_data    *list,
-                                   uint32_t        length,
-                                   IP_Port        *ip_port,
-                                   const uint8_t  *comp_client_id)
+static void test_addto_lists_possible_bad(DHT            *dht,
+        Client_data    *list,
+        uint32_t        length,
+        IP_Port        *ip_port,
+        const uint8_t  *comp_client_id)
 {
     // check "possibly bad" clients replacement
     int used, test1, test2, test3;
@@ -265,11 +268,11 @@ void test_addto_lists_possible_bad(DHT            *dht,
     }
 }
 
-void test_addto_lists_good(DHT            *dht,
-                           Client_data    *list,
-                           uint32_t        length,
-                           IP_Port        *ip_port,
-                           const uint8_t  *comp_client_id)
+static void test_addto_lists_good(DHT            *dht,
+                                  Client_data    *list,
+                                  uint32_t        length,
+                                  IP_Port        *ip_port,
+                                  const uint8_t  *comp_client_id)
 {
     uint8_t public_key[crypto_box_PUBLICKEYBYTES];
     uint8_t ipv6 = ip_port->ip.family == AF_INET6 ? 1 : 0;
@@ -295,8 +298,6 @@ void test_addto_lists_good(DHT            *dht,
     ck_assert_msg(client_in_list(list, length, public_key) == -1, "Good client id is in the list");
 }
 
-// These tests currently fail.
-#if 0
 static void test_addto_lists(IP ip)
 {
     Networking_Core *net = new_networking(NULL, ip, TOX_PORT_DEFAULT);
@@ -382,7 +383,7 @@ END_TEST
 
 #define DHT_LIST_LENGTH 128
 
-void print_pk(uint8_t *public_key)
+static void print_pk(uint8_t *public_key)
 {
     uint32_t j;
 
@@ -393,8 +394,9 @@ void print_pk(uint8_t *public_key)
     printf("\n");
 }
 
-void test_add_to_list(uint8_t cmp_list[][crypto_box_PUBLICKEYBYTES + 1], unsigned int length, const uint8_t *pk,
-                      const uint8_t *cmp_pk)
+static void test_add_to_list(uint8_t cmp_list[][crypto_box_PUBLICKEYBYTES + 1],
+                             unsigned int length, const uint8_t *pk,
+                             const uint8_t *cmp_pk)
 {
     uint8_t p_b[crypto_box_PUBLICKEYBYTES];
     unsigned int i;
@@ -423,7 +425,7 @@ void test_add_to_list(uint8_t cmp_list[][crypto_box_PUBLICKEYBYTES + 1], unsigne
 
 #define NUM_DHT 100
 
-void test_list_main()
+static void test_list_main(void)
 {
     DHT *dhts[NUM_DHT];
 
@@ -555,7 +557,7 @@ START_TEST(test_list)
 }
 END_TEST
 
-void ip_callback(void *data, int32_t number, IP_Port ip_port)
+static void ip_callback(void *data, int32_t number, IP_Port ip_port)
 {
 }
 
@@ -646,7 +648,7 @@ loop_top:
 }
 END_TEST
 
-Suite *dht_suite(void)
+static Suite *dht_suite(void)
 {
     Suite *s = suite_create("DHT");