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, 21 insertions, 20 deletions

diff --git a/auto_tests/onion_test.c b/auto_tests/onion_test.c
index 58fde2d6..dd5a1946 100644
--- a/auto_tests/onion_test.c
+++ b/auto_tests/onion_test.c
@@ -23,7 +23,7 @@
 #define c_sleep(x) usleep(1000*x)
 #endif
 
-void do_onion(Onion *onion)
+static void do_onion(Onion *onion)
 {
     networking_poll(onion->net, NULL);
     do_DHT(onion->dht);
@@ -38,7 +38,7 @@ static int handle_test_1(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
-    if (send_onion_response(onion->net, source, (uint8_t *)"install gentoo", sizeof("install gentoo"),
+    if (send_onion_response(onion->net, source, (const uint8_t *)"install gentoo", sizeof("install gentoo"),
                             packet + sizeof("Install Gentoo")) == -1) {
         return 1;
     }
@@ -54,14 +54,14 @@ static int handle_test_2(void *object, IP_Port source, const uint8_t *packet, ui
         return 1;
     }
 
-    if (memcmp(packet, (uint8_t *)"install gentoo", sizeof("install gentoo")) != 0) {
+    if (memcmp(packet, (const uint8_t *)"install gentoo", sizeof("install gentoo")) != 0) {
         return 1;
     }
 
     handled_test_2 = 1;
     return 0;
 }
-/*
+#if 0
 void print_client_id(uint8_t *client_id, uint32_t length)
 {
     uint32_t j;
@@ -69,13 +69,14 @@ void print_client_id(uint8_t *client_id, uint32_t length)
     for (j = 0; j < length; j++) {
         printf("%02hhX", client_id[j]);
     }
+
     printf("\n");
 }
-*/
-uint8_t sb_data[ONION_ANNOUNCE_SENDBACK_DATA_LENGTH];
+#endif
+static uint8_t sb_data[ONION_ANNOUNCE_SENDBACK_DATA_LENGTH];
 static int handled_test_3;
-uint8_t test_3_pub_key[crypto_box_PUBLICKEYBYTES];
-uint8_t test_3_ping_id[crypto_hash_sha256_BYTES];
+static uint8_t test_3_pub_key[crypto_box_PUBLICKEYBYTES];
+static uint8_t test_3_ping_id[crypto_hash_sha256_BYTES];
 static int handle_test_3(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
 {
     Onion *onion = object;
@@ -106,7 +107,7 @@ static int handle_test_3(void *object, IP_Port source, const uint8_t *packet, ui
     return 0;
 }
 
-uint8_t nonce[crypto_box_NONCEBYTES];
+static uint8_t nonce[crypto_box_NONCEBYTES];
 static int handled_test_4;
 static int handle_test_4(void *object, IP_Port source, const uint8_t *packet, uint16_t length, void *userdata)
 {
@@ -165,7 +166,7 @@ START_TEST(test_basic)
     nodes[3] = n2;
     Onion_Path path;
     create_onion_path(onion1->dht, &path, nodes);
-    int ret = send_onion_packet(onion1->net, &path, nodes[3].ip_port, (uint8_t *)"Install Gentoo",
+    int ret = send_onion_packet(onion1->net, &path, nodes[3].ip_port, (const uint8_t *)"Install Gentoo",
                                 sizeof("Install Gentoo"));
     ck_assert_msg(ret == 0, "Failed to create/send onion packet.");
 
@@ -227,7 +228,7 @@ START_TEST(test_basic)
     new_nonce(nonce);
     ret = send_data_request(onion3->net, &path, nodes[3].ip_port, onion1->dht->self_public_key,
                             onion1->dht->self_public_key,
-                            nonce, (uint8_t *)"Install gentoo", sizeof("Install gentoo"));
+                            nonce, (const uint8_t *)"Install gentoo", sizeof("Install gentoo"));
     ck_assert_msg(ret == 0, "Failed to create/send onion data_request packet.");
     handled_test_4 = 0;
 
@@ -278,7 +279,7 @@ typedef struct {
     Onion_Client *onion_c;
 } Onions;
 
-Onions *new_onions(uint16_t port)
+static Onions *new_onions(uint16_t port)
 {
     IP ip;
     ip_init(&ip, 1);
@@ -297,14 +298,14 @@ Onions *new_onions(uint16_t port)
     return NULL;
 }
 
-void do_onions(Onions *on)
+static void do_onions(Onions *on)
 {
     networking_poll(on->onion->net, NULL);
     do_DHT(on->onion->dht);
     do_onion_client(on->onion_c);
 }
 
-void kill_onions(Onions *on)
+static void kill_onions(Onions *on)
 {
     Networking_Core *net = on->onion->dht->net;
     DHT *dht = on->onion->dht;
@@ -322,8 +323,8 @@ void kill_onions(Onions *on)
 #define NUM_FIRST 7
 #define NUM_LAST 37
 
-_Bool first_ip, last_ip;
-void dht_ip_callback(void *object, int32_t number, IP_Port ip_port)
+static _Bool first_ip, last_ip;
+static void dht_ip_callback(void *object, int32_t number, IP_Port ip_port)
 {
     if (NUM_FIRST == number) {
         first_ip = 1;
@@ -338,9 +339,9 @@ void dht_ip_callback(void *object, int32_t number, IP_Port ip_port)
     ck_abort_msg("Error.");
 }
 
-_Bool first, last;
-uint8_t first_dht_pk[crypto_box_PUBLICKEYBYTES];
-uint8_t last_dht_pk[crypto_box_PUBLICKEYBYTES];
+static _Bool first, last;
+static uint8_t first_dht_pk[crypto_box_PUBLICKEYBYTES];
+static uint8_t last_dht_pk[crypto_box_PUBLICKEYBYTES];
 
 static void dht_pk_callback(void *object, int32_t number, const uint8_t *dht_public_key, void *userdata)
 {
@@ -460,7 +461,7 @@ START_TEST(test_announce)
 }
 END_TEST
 
-Suite *onion_suite(void)
+static Suite *onion_suite(void)
 {
     Suite *s = suite_create("Onion");