Allow weight to be assigned to Subnets.
Tinc allows multiple nodes to own the same Subnet, but did not have a sensible way to decide which one to send packets to. Tinc also did not check the reachability of nodes when deciding where to route packets to, so it would not automatically fail over to a reachable node. Tinc now assigns a weight to each Subnet. The default weight is 10, with lower weights having higher priority. The Subnets are now internally sorted in the same way as the kernel's routing table, and the Subnets are search linearly, skipping those of unreachable nodes. A small cache of recently used addresses is used to speed up the lookup functions.
This commit is contained in:
Guus Sliepen
parent
76a1bcaffc
commit
5674bba5c5
5 changed files with 148 additions and 67 deletions
195
src/subnet.c
195
src/subnet.c
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@ -37,6 +37,23 @@
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avl_tree_t *subnet_tree;
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/* Subnet lookup cache */
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static ipv4_t cache_ipv4_address[2];
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static subnet_t *cache_ipv4_subnet[2];
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static bool cache_ipv4_valid[2];
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static int cache_ipv4_slot;
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static ipv6_t cache_ipv6_address[2];
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static subnet_t *cache_ipv6_subnet[2];
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static bool cache_ipv6_valid[2];
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static int cache_ipv6_slot;
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void subnet_cache_flush() {
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cache_ipv4_valid[0] = cache_ipv4_valid[1] = false;
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cache_ipv6_valid[0] = cache_ipv6_valid[1] = false;
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}
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/* Subnet comparison */
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static int subnet_compare_mac(const subnet_t *a, const subnet_t *b)
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@ -45,6 +62,11 @@ static int subnet_compare_mac(const subnet_t *a, const subnet_t *b)
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result = memcmp(&a->net.mac.address, &b->net.mac.address, sizeof(mac_t));
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if(result)
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return result;
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result = a->weight - b->weight;
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if(result || !a->owner || !b->owner)
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return result;
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@ -55,12 +77,17 @@ static int subnet_compare_ipv4(const subnet_t *a, const subnet_t *b)
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{
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int result;
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result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
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result = b->net.ipv4.prefixlength - a->net.ipv4.prefixlength;
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if(result)
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return result;
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result = a->net.ipv4.prefixlength - b->net.ipv4.prefixlength;
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result = memcmp(&a->net.ipv4.address, &b->net.ipv4.address, sizeof(ipv4_t));
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if(result)
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return result;
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result = a->weight - b->weight;
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if(result || !a->owner || !b->owner)
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return result;
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@ -72,12 +99,17 @@ static int subnet_compare_ipv6(const subnet_t *a, const subnet_t *b)
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{
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int result;
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result = b->net.ipv6.prefixlength - a->net.ipv6.prefixlength;
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if(result)
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return result;
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result = memcmp(&a->net.ipv6.address, &b->net.ipv6.address, sizeof(ipv6_t));
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if(result)
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return result;
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result = a->net.ipv6.prefixlength - b->net.ipv6.prefixlength;
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result = a->weight - b->weight;
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if(result || !a->owner || !b->owner)
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return result;
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@ -118,6 +150,8 @@ void init_subnets(void)
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cp();
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subnet_tree = avl_alloc_tree((avl_compare_t) subnet_compare, (avl_action_t) free_subnet);
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subnet_cache_flush();
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}
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void exit_subnets(void)
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@ -167,6 +201,8 @@ void subnet_add(node_t *n, subnet_t *subnet)
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avl_insert(subnet_tree, subnet);
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avl_insert(n->subnet_tree, subnet);
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subnet_cache_flush();
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}
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void subnet_del(node_t *n, subnet_t *subnet)
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@ -175,6 +211,8 @@ void subnet_del(node_t *n, subnet_t *subnet)
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avl_delete(n->subnet_tree, subnet);
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avl_delete(subnet_tree, subnet);
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subnet_cache_flush();
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}
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/* Ascii representation of subnets */
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@ -183,16 +221,18 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
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{
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int i, l;
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uint16_t x[8];
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int weight = 10;
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cp();
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if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d",
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&x[0], &x[1], &x[2], &x[3], &l) == 5) {
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if(sscanf(subnetstr, "%hu.%hu.%hu.%hu/%d#%d",
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&x[0], &x[1], &x[2], &x[3], &l, &weight) >= 5) {
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if(l < 0 || l > 32)
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return false;
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subnet->type = SUBNET_IPV4;
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subnet->net.ipv4.prefixlength = l;
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subnet->weight = weight;
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for(i = 0; i < 4; i++) {
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if(x[i] > 255)
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@ -203,14 +243,15 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
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return true;
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}
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
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&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7],
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&l) == 9) {
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&l, &weight) >= 9) {
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if(l < 0 || l > 128)
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return false;
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subnet->type = SUBNET_IPV6;
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subnet->net.ipv6.prefixlength = l;
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subnet->weight = weight;
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for(i = 0; i < 8; i++)
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subnet->net.ipv6.address.x[i] = htons(x[i]);
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@ -218,9 +259,10 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
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return true;
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}
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if(sscanf(subnetstr, "%hu.%hu.%hu.%hu", &x[0], &x[1], &x[2], &x[3]) == 4) {
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if(sscanf(subnetstr, "%hu.%hu.%hu.%hu#%d", &x[0], &x[1], &x[2], &x[3], &weight) >= 4) {
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subnet->type = SUBNET_IPV4;
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subnet->net.ipv4.prefixlength = 32;
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subnet->weight = weight;
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for(i = 0; i < 4; i++) {
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if(x[i] > 255)
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@ -231,10 +273,11 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
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return true;
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}
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx",
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&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7]) == 8) {
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx#%d",
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&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &x[6], &x[7], &weight) >= 8) {
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subnet->type = SUBNET_IPV6;
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subnet->net.ipv6.prefixlength = 128;
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subnet->weight = weight;
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for(i = 0; i < 8; i++)
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subnet->net.ipv6.address.x[i] = htons(x[i]);
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@ -242,9 +285,10 @@ bool str2net(subnet_t *subnet, const char *subnetstr)
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return true;
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}
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx",
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&x[0], &x[1], &x[2], &x[3], &x[4], &x[5]) == 6) {
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if(sscanf(subnetstr, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
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&x[0], &x[1], &x[2], &x[3], &x[4], &x[5], &weight) >= 6) {
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subnet->type = SUBNET_MAC;
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subnet->weight = weight;
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for(i = 0; i < 6; i++)
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subnet->net.mac.address.x[i] = x[i];
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@ -266,24 +310,28 @@ bool net2str(char *netstr, int len, const subnet_t *subnet)
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switch (subnet->type) {
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case SUBNET_MAC:
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snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx",
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snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx#%d",
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subnet->net.mac.address.x[0],
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subnet->net.mac.address.x[1],
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subnet->net.mac.address.x[2],
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subnet->net.mac.address.x[3],
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subnet->net.mac.address.x[4], subnet->net.mac.address.x[5]);
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subnet->net.mac.address.x[4],
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subnet->net.mac.address.x[5],
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subnet->weight);
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break;
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case SUBNET_IPV4:
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snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d",
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snprintf(netstr, len, "%hu.%hu.%hu.%hu/%d#%d",
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subnet->net.ipv4.address.x[0],
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subnet->net.ipv4.address.x[1],
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subnet->net.ipv4.address.x[2],
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subnet->net.ipv4.address.x[3], subnet->net.ipv4.prefixlength);
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subnet->net.ipv4.address.x[3],
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subnet->net.ipv4.prefixlength,
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subnet->weight);
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break;
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case SUBNET_IPV6:
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snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d",
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snprintf(netstr, len, "%hx:%hx:%hx:%hx:%hx:%hx:%hx:%hx/%d#%d",
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ntohs(subnet->net.ipv6.address.x[0]),
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ntohs(subnet->net.ipv6.address.x[1]),
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ntohs(subnet->net.ipv6.address.x[2]),
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@ -292,7 +340,8 @@ bool net2str(char *netstr, int len, const subnet_t *subnet)
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ntohs(subnet->net.ipv6.address.x[5]),
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ntohs(subnet->net.ipv6.address.x[6]),
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ntohs(subnet->net.ipv6.address.x[7]),
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subnet->net.ipv6.prefixlength);
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subnet->net.ipv6.prefixlength,
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subnet->weight);
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break;
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default:
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@ -332,80 +381,96 @@ subnet_t *lookup_subnet_mac(const mac_t *address)
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subnet_t *lookup_subnet_ipv4(const ipv4_t *address)
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{
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subnet_t *p, subnet = {0};
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subnet_t *p, *r = NULL, subnet = {0};
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avl_node_t *n;
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int i;
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cp();
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// Check if this address is cached
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for(i = 0; i < 2; i++) {
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if(!cache_ipv4_valid[i])
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continue;
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if(!memcmp(address, &cache_ipv4_address[i], sizeof *address))
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return cache_ipv4_subnet[i];
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}
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// Search all subnets for a matching one
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subnet.type = SUBNET_IPV4;
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subnet.net.ipv4.address = *address;
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subnet.net.ipv4.prefixlength = 32;
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subnet.owner = NULL;
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do {
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/* Go find subnet */
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for(n = subnet_tree->head; n; n = n->next) {
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p = n->data;
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if(!p || p->type != subnet.type)
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continue;
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p = avl_search_closest_smaller(subnet_tree, &subnet);
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/* Check if the found subnet REALLY matches */
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if(p) {
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if(p->type != SUBNET_IPV4) {
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p = NULL;
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if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength)) {
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r = p;
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if(p->owner->status.reachable)
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break;
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}
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if(!maskcmp(address, &p->net.ipv4.address, p->net.ipv4.prefixlength))
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break;
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else {
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/* Otherwise, see if there is a bigger enclosing subnet */
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subnet.net.ipv4.prefixlength = p->net.ipv4.prefixlength - 1;
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if(subnet.net.ipv4.prefixlength < 0 || subnet.net.ipv4.prefixlength > 32)
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return NULL;
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maskcpy(&subnet.net.ipv4.address, &p->net.ipv4.address, subnet.net.ipv4.prefixlength, sizeof(ipv4_t));
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}
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}
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} while(p);
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}
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return p;
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// Cache the result
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cache_ipv4_slot = !cache_ipv4_slot;
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memcpy(&cache_ipv4_address[cache_ipv4_slot], address, sizeof *address);
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cache_ipv4_subnet[cache_ipv4_slot] = r;
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cache_ipv4_valid[cache_ipv4_slot] = true;
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return r;
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}
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subnet_t *lookup_subnet_ipv6(const ipv6_t *address)
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{
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subnet_t *p, subnet = {0};
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subnet_t *p, *r = NULL, subnet = {0};
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avl_node_t *n;
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int i;
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cp();
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// Check if this address is cached
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for(i = 0; i < 2; i++) {
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if(!cache_ipv6_valid[i])
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continue;
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if(!memcmp(address, &cache_ipv6_address[i], sizeof *address))
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return cache_ipv6_subnet[i];
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}
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// Search all subnets for a matching one
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subnet.type = SUBNET_IPV6;
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subnet.net.ipv6.address = *address;
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subnet.net.ipv6.prefixlength = 128;
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subnet.owner = NULL;
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do {
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/* Go find subnet */
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for(n = subnet_tree->head; n; n = n->next) {
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p = n->data;
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if(!p || p->type != subnet.type)
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continue;
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p = avl_search_closest_smaller(subnet_tree, &subnet);
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/* Check if the found subnet REALLY matches */
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if(p) {
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if(p->type != SUBNET_IPV6)
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return NULL;
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if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength))
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if(!maskcmp(address, &p->net.ipv6.address, p->net.ipv6.prefixlength)) {
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r = p;
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if(p->owner->status.reachable)
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break;
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else {
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/* Otherwise, see if there is a bigger enclosing subnet */
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subnet.net.ipv6.prefixlength = p->net.ipv6.prefixlength - 1;
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if(subnet.net.ipv6.prefixlength < 0 || subnet.net.ipv6.prefixlength > 128)
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return NULL;
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maskcpy(&subnet.net.ipv6.address, &p->net.ipv6.address, subnet.net.ipv6.prefixlength, sizeof(ipv6_t));
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}
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}
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} while(p);
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}
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return p;
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// Cache the result
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cache_ipv6_slot = !cache_ipv6_slot;
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memcpy(&cache_ipv6_address[cache_ipv6_slot], address, sizeof *address);
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cache_ipv6_subnet[cache_ipv6_slot] = r;
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cache_ipv6_valid[cache_ipv6_slot] = true;
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return r;
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}
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void subnet_update(node_t *owner, subnet_t *subnet, bool up) {
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