From 9bbead0ac73edc9b991f9facc853e6dde9e49410 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Anton=20Luka=20=C5=A0ijanec?= <anton@sijanec.eu>
Date: Thu, 8 Dec 2022 11:40:56 +0100
Subject: untested for compilation, dht.c -- TODO: DNS+bootstrap

---
 makefile   |  2 +-
 src/dht.c  | 80 ++++++++++++++++++++++++++++++++++++++++++++++----------------
 src/main.c |  2 ++
 3 files changed, 63 insertions(+), 21 deletions(-)

diff --git a/makefile b/makefile
index 5de5868..9aac5dc 100644
--- a/makefile
+++ b/makefile
@@ -3,7 +3,7 @@ CC=cc
 
 default:
 	mkdir -p tmp
-	$(CC) -Wall -Wextra -Wformat -pedantic -g -Isrc -Itmp $(CFLAGS) src/main.c -otravnik -lm $(LDFLAGS)
+	$(CC) -Wall -Wextra -Wformat -pedantic -g -Isrc -Itmp -Itiny-AES-c $(CFLAGS) src/main.c -otravnik -lm $(LDFLAGS)
 
 install:
 	mkdir -p $(DESTDIR)/usr/bin/
diff --git a/src/dht.c b/src/dht.c
index 05403e4..18d23b4 100644
--- a/src/dht.c
+++ b/src/dht.c
@@ -722,8 +722,8 @@ int bucket_good (const struct dht * d, const struct bucket * b) {
 		if (in_bucket(d->id, b)) {
 			struct node * n = b->nodes;
 			while (n->next) {
-				if (distance(n->id, n->next->id) != 1)
-					return 0;
+				if (distance(n->id, n->next->id) <= 2)	// we allow holes of 1, since we don't actually store our ID in the bucket
+					return 0;			// it's really impossible that a non-malicious node would by chance get so close
 			}
 			return 1;
 		}
@@ -1392,26 +1392,33 @@ void handle (struct dht * d, char * pkt, int len, struct sockaddr_in6 addr) {
  * do periodic housekeeping on the routing table LL, making sure no nodes are bad. removes bad nodes and does not ping questionable nodes. see NOTE03
  *
  * @param b	[in]	first bucket in LL - basically either d->buckets or d->buckets6
+ * @return number of good nodes
  */
 
-void refresh (struct bucket * b) {
-	struct node ** n = &b->nodes;
-	while (*n) {
-		switch (node_grade(*n)) {
-			case bad:
-				;
-				struct node * old = *n;
-				*n = (*n)->next;
-				node_free(old);
-				break;
-			case questionable:
-				// ping_node(d, *n); // NOTE03 about not pinging questionable nodes: this ensures a constant regeneration of the routing table. this is just an idea, if the client frequently gets in a situation without any nodes in the routing table, remove the comment before ping_node call.
-				break;
-			case good:
-				break;
+int refresh (struct bucket * b) {
+	int good = 0;
+	while (b) {
+		struct node ** n = &b->nodes;
+		while (*n) {
+			switch (node_grade(*n)) {
+				case bad:
+					;
+					struct node * old = *n;
+					*n = (*n)->next;
+					node_free(old);
+					break;
+				case questionable:
+					// ping_node(d, *n); // NOTE03 about not pinging questionable nodes: this ensures a constant regeneration of the routing table. this is just an idea, if the client frequently gets in a situation without any nodes in the routing table, remove the comment before ping_node call.
+					break;
+				case good:
+					good++;
+					break;
+			}
+			n = &(*n)->next;
 		}
-		n = &(*n)->next;
+		b = b->next;
 	}
+	return good;
 }
 
 /**
@@ -1474,16 +1481,49 @@ void get_peers (struct dht * d, const struct sockaddr_in6 * addr, const unsigned
  */
 
 void periodic (struct dht * d) {
-	refresh(d->buckets);
-	refresh(d->buckets6);
+	int dns = 0;
+	if (!refresh(d->buckets))
+		dns++;
+	if (!refresh(d->buckets6))
+		dns++;
+	if (dns) {
+		
+		// perform a query to SRV travnik.sijanec.eu, continue with parsing in handle()
+	}
 	struct torrent * t = d->torrents;
 	while (t) {
 		if (t->type & (peers | announce)) {
 			struct node * n = t->nodes;
+			int sent = 0;
 			while (n) {
+				sent++;
 				get_peers(d, &n->addr, t->hash);
 				n = n->next;
 			}
+			if (sent < K) {
+#define RTGP(buckets)		struct bucket * b = d->buckets; \
+				find(t->hash, &b, NULL); \
+				struct node * n = b->nodes; \
+				while (sent < K && n) { \
+					sent++; \
+					get_peers(d, &n->addr, t->hash); \
+					n = n->next;
+				}
+				RTGP(buckets);
+				RTGP(buckets6);
+			}
+			if (sent < K) {
+				struct bucket * b = d->buckets;
+				while (sent < K && b) {
+					n = b->nodes;
+					while (sent < K && n) {
+						sent++;
+						get_peers(d, &n->addr, t->hash);
+						n = n->next;
+					}
+					b = b->next;
+				}
+			}
 		}
 		t = t->next;
 	}
diff --git a/src/main.c b/src/main.c
index e8debe6..70d12fb 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1,5 +1,7 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+#include <dht.c>
 int main (void) {
+	struct dht * dht = dht_init();
 }
-- 
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