struct loc_stringpool* pool;
};
+#define MAX_STACK_DEPTH 256
+
+struct loc_node_stack {
+ off_t offset;
+ int i; // Is this node 0 or 1?
+ int depth;
+};
+
struct loc_database_enumerator {
struct loc_ctx* ctx;
struct loc_database* db;
// Search string
char* string;
+ char country_code[3];
// Index of the AS we are looking at
unsigned int as_index;
+
+ // Network state
+ struct in6_addr network_address;
+ struct loc_node_stack network_stack[MAX_STACK_DEPTH];
+ int network_stack_depth;
+ unsigned int* networks_visited;
};
static int loc_database_read_magic(struct loc_database* db, FILE* f) {
return 0;
}
-// Returns the highest result available
-static int __loc_database_lookup_max(struct loc_database* db, const struct in6_addr* address,
- struct loc_network** network, struct in6_addr* network_address,
- const struct loc_database_network_node_v0* node, unsigned int level) {
- int r;
- off_t node_index;
-
- // If the node is a leaf node, we end here
- if (__loc_database_node_is_leaf(node)) {
- r = __loc_database_lookup_handle_leaf(db, address, network, network_address, level, node);
- if (r <= 0)
- return r;
- }
-
- // Try to go down the ones path first
- if (node->one) {
- node_index = be32toh(node->one);
- in6_addr_set_bit(network_address, level, 1);
-
- // Check boundaries
- if (node_index > 0 && (size_t)node_index <= db->network_nodes_count) {
- r = __loc_database_lookup_max(db, address, network, network_address,
- db->network_nodes_v0 + node_index, level + 1);
-
- // Abort when match was found or error
- if (r <= 0)
- return r;
- }
- }
-
- // ... and if that fails, we try to go down one step on a zero
- // branch and then try the ones again...
- if (node->zero) {
- node_index = be32toh(node->zero);
- in6_addr_set_bit(network_address, level, 0);
-
- // Check boundaries
- if (node_index > 0 && (size_t)node_index <= db->network_nodes_count) {
- r = __loc_database_lookup_max(db, address, network, network_address,
- db->network_nodes_v0 + node_index, level + 1);
-
- // Abort when match was found or error
- if (r <= 0)
- return r;
- }
- }
-
- // End of path
- return 1;
-}
-
// Searches for an exact match along the path
static int __loc_database_lookup(struct loc_database* db, const struct in6_addr* address,
struct loc_network** network, struct in6_addr* network_address,
int r;
off_t node_index;
- // If the node is a leaf node, we end here
- if (__loc_database_node_is_leaf(node)) {
- r = __loc_database_lookup_handle_leaf(db, address, network, network_address, level, node);
- if (r <= 0)
- return r;
- }
-
// Follow the path
int bit = in6_addr_get_bit(address, level);
in6_addr_set_bit(network_address, level, bit);
else
node_index = be32toh(node->one);
- // If we point back to root, the path ends here
- if (node_index == 0) {
- DEBUG(db->ctx, "Tree ends here\n");
- return 1;
- }
+ // If the node index is zero, the tree ends here
+ // and we cannot descend any further
+ if (node_index > 0) {
+ // Check boundaries
+ if ((size_t)node_index >= db->network_nodes_count)
+ return -EINVAL;
- // Check boundaries
- if ((size_t)node_index >= db->network_nodes_count)
- return -EINVAL;
+ // Move on to the next node
+ r = __loc_database_lookup(db, address, network, network_address,
+ db->network_nodes_v0 + node_index, level + 1);
- // Move on to the next node
- r = __loc_database_lookup(db, address, network, network_address,
- db->network_nodes_v0 + node_index, level + 1);
+ // End here if a result was found
+ if (r == 0)
+ return r;
- // End here if a result was found
- if (r == 0)
- return r;
+ // Raise any errors
+ else if (r < 0)
+ return r;
- // Raise any errors
- else if (r < 0)
- return r;
+ DEBUG(db->ctx, "No match found below level %u\n", level);
+ } else {
+ DEBUG(db->ctx, "Tree ended at level %u\n", level);
+ }
- DEBUG(db->ctx, "Could not find an exact match at %u\n", level);
+ // If this node has a leaf, we will check if it matches
+ if (__loc_database_node_is_leaf(node)) {
+ r = __loc_database_lookup_handle_leaf(db, address, network, network_address, level, node);
+ if (r <= 0)
+ return r;
+ }
- // If nothing was found, we have to search for an inexact match
- return __loc_database_lookup_max(db, address, network, network_address, node, level);
+ return 1;
}
LOC_EXPORT int loc_database_lookup(struct loc_database* db,
e->db = loc_database_ref(db);
e->refcount = 1;
+ // Initialise graph search
+ //e->network_stack[++e->network_stack_depth] = 0;
+ e->network_stack_depth = 1;
+ e->networks_visited = calloc(db->network_nodes_count, sizeof(*e->networks_visited));
+
DEBUG(e->ctx, "Database enumerator object allocated at %p\n", e);
*enumerator = e;
if (enumerator->string)
free(enumerator->string);
+ // Free network search
+ free(enumerator->networks_visited);
+
free(enumerator);
}
return 0;
}
+LOC_EXPORT int loc_database_enumerator_set_country_code(struct loc_database_enumerator* enumerator, const char* country_code) {
+ // Set empty country code
+ if (!country_code || !*country_code) {
+ *enumerator->country_code = '\0';
+ return 0;
+ }
+
+ // Country codes must be two characters
+ if (strlen(country_code) != 2)
+ return -EINVAL;
+
+ for (unsigned int i = 0; i < 3; i++) {
+ enumerator->country_code[i] = country_code[i];
+ }
+
+ return 0;
+}
+
LOC_EXPORT struct loc_as* loc_database_enumerator_next_as(struct loc_database_enumerator* enumerator) {
struct loc_database* db = enumerator->db;
struct loc_as* as;
return NULL;
r = loc_as_match_string(as, enumerator->string);
- if (r == 0) {
+ if (r == 1) {
DEBUG(enumerator->ctx, "AS%d (%s) matches %s\n",
loc_as_get_number(as), loc_as_get_name(as), enumerator->string);
// We have searched through all of them
return NULL;
}
+
+static int loc_database_enumerator_stack_push_node(
+ struct loc_database_enumerator* e, off_t offset, int i, int depth) {
+ // Do not add empty nodes
+ if (!offset)
+ return 0;
+
+ // Check if there is any space left on the stack
+ if (e->network_stack_depth >= MAX_STACK_DEPTH) {
+ ERROR(e->ctx, "Maximum stack size reached: %d\n", e->network_stack_depth);
+ return -1;
+ }
+
+ // Increase stack size
+ int s = ++e->network_stack_depth;
+
+ DEBUG(e->ctx, "Added node %jd to stack (%d)\n", offset, depth);
+
+ e->network_stack[s].offset = offset;
+ e->network_stack[s].i = i;
+ e->network_stack[s].depth = depth;
+
+ return 0;
+}
+
+static int loc_database_enumerator_network_depth_first_search(
+ struct loc_database_enumerator* e, struct loc_network** network) {
+ // Reset network
+ *network = NULL;
+ int r;
+
+ DEBUG(e->ctx, "Called with a stack of %u nodes\n", e->network_stack_depth);
+
+ // Perform DFS
+ while (e->network_stack_depth > 0) {
+ DEBUG(e->ctx, "Stack depth: %u\n", e->network_stack_depth);
+
+ // Get object from top of the stack
+ struct loc_node_stack* node = &e->network_stack[e->network_stack_depth];
+
+ // Remove the node from the stack if we have already visited it
+ if (e->networks_visited[node->offset]) {
+ e->network_stack_depth--;
+ continue;
+ }
+
+ in6_addr_set_bit(&e->network_address,
+ (node->depth > 0) ? node->depth - 1 : 0, node->i);
+
+ //for (unsigned int i = stack->depth + 1; i < 128; i++)
+ // in6_addr_set_bit(&e->network_address, i, 0);
+
+ DEBUG(e->ctx, "Looking at node %jd\n", node->offset);
+ e->networks_visited[node->offset]++;
+
+ // Pop node from top of the stack
+ struct loc_database_network_node_v0* n =
+ e->db->network_nodes_v0 + node->offset;
+
+ // Add edges to stack
+ r = loc_database_enumerator_stack_push_node(e,
+ be32toh(n->one), 1, node->depth + 1);
+
+ if (r)
+ return r;
+
+ r = loc_database_enumerator_stack_push_node(e,
+ be32toh(n->zero), 0, node->depth + 1);
+
+ if (r)
+ return r;
+
+ // Check if this node is a leaf and has a network object
+ if (__loc_database_node_is_leaf(n)) {
+ off_t network_index = be32toh(n->network);
+
+ DEBUG(e->ctx, "Node has a network at %jd\n", network_index);
+
+ // Fetch the network object
+ r = loc_database_fetch_network(e->db, network,
+ &e->network_address, node->depth, network_index);
+
+ // Break on any errors
+ if (r)
+ return r;
+
+ // Check if we are interested in this network
+
+ // Skip if the country code does not match
+ if (e->country_code && !loc_network_match_country_code(*network, e->country_code)) {
+ loc_network_unref(*network);
+ continue;
+ }
+
+ return 0;
+ }
+ }
+
+ // Reached the end of the search
+
+ // Mark all nodes as non-visited
+ for (unsigned int i = 0; i < e->db->network_nodes_count; i++)
+ e->networks_visited[i] = 0;
+
+ return 0;
+}
+
+LOC_EXPORT struct loc_network* loc_database_enumerator_next_network(
+ struct loc_database_enumerator* enumerator) {
+ struct loc_network* network = NULL;
+
+ int r = loc_database_enumerator_network_depth_first_search(enumerator, &network);
+ if (r) {
+ return NULL;
+ }
+
+ return network;
+}