network: Store the first and last address of each network

This avoids recomputing the last address multiple times.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

diff --git a/src/network.c b/src/network.c
index 44c6f712bd9f5afbc0c328affc9211ba144f899a..a4c7646e90fccd4d4ca3622209f2d9ae202299d7 100644 (file)
--- a/src/network.c
+++ b/src/network.c
@@ -36,6 +36,7 @@ struct loc_network {
        int refcount;
 
        struct in6_addr first_address;
+       struct in6_addr last_address;
        unsigned int prefix;
 
        char country_code[3];
@@ -75,24 +76,22 @@ static struct in6_addr prefix_to_bitmask(unsigned int prefix) {
        return bitmask;
 }
 
-static struct in6_addr make_first_address(const struct in6_addr* address, unsigned int prefix) {
+static struct in6_addr make_first_address(const struct in6_addr* address, const struct in6_addr* bitmask) {
        struct in6_addr a;
-       struct in6_addr bitmask = prefix_to_bitmask(prefix);
 
        // Perform bitwise AND
        for (unsigned int i = 0; i < 4; i++)
-               a.s6_addr32[i] = address->s6_addr32[i] & bitmask.s6_addr32[i];
+               a.s6_addr32[i] = address->s6_addr32[i] & bitmask->s6_addr32[i];
 
        return a;
 }
 
-static struct in6_addr make_last_address(const struct in6_addr* address, unsigned int prefix) {
+static struct in6_addr make_last_address(const struct in6_addr* address, const struct in6_addr* bitmask) {
        struct in6_addr a;
-       struct in6_addr bitmask = prefix_to_bitmask(prefix);
 
        // Perform bitwise OR
        for (unsigned int i = 0; i < 4; i++)
-               a.s6_addr32[i] = address->s6_addr32[i] | ~bitmask.s6_addr32[i];
+               a.s6_addr32[i] = address->s6_addr32[i] | ~bitmask->s6_addr32[i];
 
        return a;
 }
@@ -136,10 +135,16 @@ LOC_EXPORT int loc_network_new(struct loc_ctx* ctx, struct loc_network** network
        n->ctx = loc_ref(ctx);
        n->refcount = 1;
 
-       // Store the first address in the network
-       n->first_address = make_first_address(address, prefix);
+       // Store the prefix
        n->prefix = prefix;
 
+       // Convert the prefix into a bitmask
+       struct in6_addr bitmask = prefix_to_bitmask(n->prefix);
+
+       // Store the first and last address in the network
+       n->first_address = make_first_address(address, &bitmask);
+       n->last_address = make_last_address(&n->first_address, &bitmask);
+
        DEBUG(n->ctx, "Network allocated at %p\n", n);
        *network = n;
        return 0;
@@ -278,11 +283,8 @@ LOC_EXPORT int loc_network_match_address(struct loc_network* network, const stru
        if (in6_addr_cmp(&network->first_address, address) > 0)
                return 1;
 
-       // Determine the last address in this network
-       struct in6_addr last_address = make_last_address(&network->first_address, network->prefix);
-
        // Address must be smaller than the last address
-       if (in6_addr_cmp(address, &last_address) > 0)
+       if (in6_addr_cmp(&network->last_address, address) < 0)
                return 1;
 
        // The address is inside this network
@@ -352,13 +354,9 @@ LOC_EXPORT int loc_network_is_subnet_of(struct loc_network* self, struct loc_net
        if (in6_addr_cmp(&self->first_address, &other->first_address) < 0)
                return 0;
 
-       // Get the end addresses
-       struct in6_addr last_address_self  = make_last_address(&self->first_address,  self->prefix);
-       struct in6_addr last_address_other = make_last_address(&other->first_address, other->prefix);
-
        // If the end address of the other network is greater than this network,
        // it cannot be a subnet.
-       if (in6_addr_cmp(&last_address_self, &last_address_other) > 0)
+       if (in6_addr_cmp(&self->last_address, &other->last_address) > 0)
                return 0;
 
        return 1;