From 92ea4656530fc85dd82376883767c4c593deb121 Mon Sep 17 00:00:00 2001
From: Erik Ekman <yarrick@kryo.se>
Date: Sun, 20 Sep 2009 21:10:39 +0000
Subject: [PATCH] #76 merge dns and user

---
 src/dns.c     |  7 +++++++
 src/iodined.c |  1 +
 src/user.c    | 25 +++++++++++++++----------
 src/user.h    | 23 +++++++++++++++++++++++
 4 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/src/dns.c b/src/dns.c
index 8f6cae8..80c31e8 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -356,6 +356,13 @@ dns_decode(char *buf, size_t buflen, struct query *q, qr_t qr, char *packet, siz
 		readshort(packet, &data, &type);
 		readshort(packet, &data, &class);
 		
+		/* if CHECKLEN okay, then we're sure to have a proper name */
+		if (q != NULL) {
+			/* We only need the first char to check it */
+			q->name[0] = name[0];
+			q->name[1] = '\0';
+		}
+
 		/* Assume that first answer is NULL/CNAME that we wanted */
 		readname(packet, packetlen, &data, name, sizeof(name));
 		CHECKLEN(10);
diff --git a/src/iodined.c b/src/iodined.c
index 6ce7d98..8babe62 100644
--- a/src/iodined.c
+++ b/src/iodined.c
@@ -376,6 +376,7 @@ handle_null_request(int tun_fd, int dns_fd, struct query *q, int domain_len)
 				users[userid].inpacket.seqno = 0;
 				users[userid].inpacket.fragment = 0;
 				users[userid].fragsize = 100; /* very safe */
+				users[userid].conn = CONN_DNS_NULL;
 			} else {
 				/* No space for another user */
 				send_version_response(dns_fd, VERSION_FULL, created_users, 0, q);
diff --git a/src/user.c b/src/user.c
index 32b35c1..b2e8f04 100644
--- a/src/user.c
+++ b/src/user.c
@@ -78,14 +78,8 @@ init_users(in_addr_t my_ip, int netbits)
 			users[i].disabled = 0;
 			created_users++;
 		}
-		users[i].inpacket.len = 0;
-		users[i].inpacket.offset = 0;
-		users[i].outpacket.len = 0;
-		users[i].q.id = 0;
-		users[i].out_acked_seqno = 0;
-		users[i].out_acked_fragment = 0;
-		users[i].fragsize = 4096;
-		users[i].conn = CONN_DNS_NULL;
+		users[i].active = 0;
+ 		/* Rest is reset on login ('V' packet) */
 	}
 
 	return created_users;
@@ -129,6 +123,11 @@ find_user_by_ip(uint32_t ip)
 
 int
 all_users_waiting_to_send()
+/* If this returns true, then reading from tun device is blocked.
+   So only return true when all clients have at least one packet in
+   the outpacket-queue, so that sending back-to-back is possible
+   without going through another select loop.
+*/
 {
 	time_t now;
 	int ret;
@@ -139,8 +138,14 @@ all_users_waiting_to_send()
 	for (i = 0; i < USERS; i++) {
 		if (users[i].active && !users[i].disabled &&
 			users[i].last_pkt + 60 > now &&
-			((users[i].outpacket.len == 0 && users[i].conn == CONN_DNS_NULL) 
-				|| users[i].conn == CONN_RAW_UDP)) {
+			((users[i].conn == CONN_RAW_UDP) || 
+			((users[i].conn == CONN_DNS_NULL) 
+#ifdef OUTPACKETQ_LEN
+				&& users[i].outpacketq_filled < 1
+#else
+				&& users[i].outpacket.len == 0
+#endif
+			))) {
 
 			ret = 0;
 			break;
diff --git a/src/user.h b/src/user.h
index 6058a8d..d3f81b4 100644
--- a/src/user.h
+++ b/src/user.h
@@ -19,6 +19,13 @@
 
 #define USERS 16
 
+#define OUTPACKETQ_LEN 4		/* Note: 16 users * 1 packet = 1MB */
+/* Undefine to have no queue for packets coming in from tun device, which may
+   lead to massive dropping in multi-user situations with high traffic. */
+
+#define DNSCACHE_LEN 4
+/* Undefine to disable. MUST be less than 7; also see comments in iodined.c */
+
 struct user {
 	char id;
 	int active;
@@ -28,14 +35,30 @@ struct user {
 	in_addr_t tun_ip;
 	struct in_addr host;
 	struct query q;
+	struct query q_prev;
+	struct query q_sendrealsoon;
+	int q_sendrealsoon_new;
 	struct packet inpacket;
 	struct packet outpacket;
+	int outfragresent;
 	struct encoder *encoder;
 	char downenc;
 	int out_acked_seqno;
 	int out_acked_fragment;
 	int fragsize;
 	enum connection conn;
+	int lazy;
+#ifdef OUTPACKETQ_LEN
+	struct packet outpacketq[OUTPACKETQ_LEN];
+	int outpacketq_nexttouse;
+	int outpacketq_filled;
+#endif
+#ifdef DNSCACHE_LEN
+	struct query dnscache_q[DNSCACHE_LEN];
+	char dnscache_answer[DNSCACHE_LEN][4096];
+	int dnscache_answerlen[DNSCACHE_LEN];
+	int dnscache_lastfilled;
+#endif
 };
 
 extern struct user users[USERS];