Enable and fix many extra warnings supported by GCC and Clang.

[tinc] / src / subnet.c

diff --git a/src/subnet.c b/src/subnet.c
index 8c76637..1ddf11e 100644 (file)
--- a/src/subnet.c
+++ b/src/subnet.c
@@ -1,6 +1,6 @@
 /*
     subnet.c -- handle subnet lookups and lists
-    Copyright (C) 2000-2017 Guus Sliepen <guus@tinc-vpn.org>,
+    Copyright (C) 2000-2022 Guus Sliepen <guus@tinc-vpn.org>,
                   2000-2005 Ivo Timmermans
 
     This program is free software; you can redistribute it and/or modify
@@ -22,6 +22,7 @@
 
 #include "splay_tree.h"
 #include "control_common.h"
+#include "crypto.h"
 #include "hash.h"
 #include "logger.h"
 #include "net.h"
@@ -40,6 +41,14 @@ splay_tree_t subnet_tree = {
 
 /* Subnet lookup cache */
 
+static uint32_t wrapping_add32(uint32_t a, uint32_t b) {
+       return (uint32_t)((uint64_t)a + b);
+}
+
+static uint32_t wrapping_mul32(uint32_t a, uint32_t b) {
+       return (uint32_t)((uint64_t)a * b);
+}
+
 static uint32_t hash_function_ipv4_t(const ipv4_t *p) {
        /*
        This basic hash works because
@@ -51,7 +60,7 @@ static uint32_t hash_function_ipv4_t(const ipv4_t *p) {
 
 #if __BYTE_ORDER == __LITTLE_ENDIAN
        // 10.0.x.x/16 part
-       hash += halfwidth[1] * 0x9e370001UL;
+       hash = wrapping_add32(hash, wrapping_mul32(halfwidth[1], 0x9e370001U));
 
        // x.x.0.[0-255] part
 #if SUBNET_HASH_SIZE >= 0x10000
@@ -62,7 +71,7 @@ static uint32_t hash_function_ipv4_t(const ipv4_t *p) {
 #endif // _____LP64_____
 #else
        // 10.0.x.x/16 part
-       hash += halfwidth[0] * 0x9e370001UL;
+       hash = wrapping_add32(hash, wrapping_mul32(halfwidth[0], 0x9e370001U));
 
        // x.x.0.[0-255] part (ntohs is nop on big endian)
        return hash ^ halfwidth[1];
@@ -75,8 +84,8 @@ static uint32_t hash_function_ipv6_t(const ipv6_t *p) {
        uint32_t hash = hash_seed;
 
        for(int i = 0; i < 4; i++) {
-               hash += fullwidth[i];
-               hash *= 0x9e370001UL;
+               hash = wrapping_add32(hash, fullwidth[i]);
+               hash = wrapping_mul32(hash, 0x9e370001U);
        }
 
        return hash;
@@ -87,8 +96,8 @@ static uint32_t hash_function_mac_t(const mac_t *p) {
        uint32_t hash = hash_seed;
 
        for(int i = 0; i < 3; i++) {
-               hash += halfwidth[i];
-               hash *= 0x9e370001UL;
+               hash = wrapping_add32(hash, halfwidth[i]);
+               hash = wrapping_mul32(hash, 0x9e370001U);
        }
 
        return hash;
@@ -120,7 +129,10 @@ void subnet_cache_flush_table(subnet_type_t stype) {
 /* Initialising trees */
 
 void init_subnets(void) {
-       hash_seed = (uint32_t)rand();
+       hash_seed = prng(UINT32_MAX);
+
+       // tables need to be cleared on startup
+       subnet_cache_flush_tables();
 }
 
 void exit_subnets(void) {
@@ -150,7 +162,7 @@ void subnet_cache_flush_tables(void) {
        hash_clear(mac_t, &mac_cache);
 }
 
-void subnet_cache_flush(subnet_t *subnet) {
+static void subnet_cache_flush(subnet_t *subnet) {
        switch(subnet->type) {
        case SUBNET_IPV4:
                if(subnet->net.ipv4.prefixlength == 32) {
@@ -310,7 +322,7 @@ subnet_t *lookup_subnet_ipv6(const ipv6_t *address) {
 
 void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
        char netstr[MAXNETSTR];
-       char *name, *address, *port;
+       char *address, *port;
        char empty[] = "";
 
        // Prepare environment variables to be passed to the script
@@ -330,7 +342,7 @@ void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
        int env_subnet = environment_add(&env, NULL);
        int env_weight = environment_add(&env, NULL);
 
-       name = up ? "subnet-up" : "subnet-down";
+       const char *name = up ? "subnet-up" : "subnet-down";
 
        if(!subnet) {
                for splay_each(subnet_t, subnet, &owner->subnet_tree) {