Implemented link padding and receiver token buckets

Each socket reads at most 'bandwidth' bytes per second sustained, but
can handle bursts of up to 10*bandwidth bytes.

Cells are now sent out at evenly-spaced intervals, with padding sent
out otherwise. Set Linkpadding=0 in the rc file to send cells as soon
as they're available (and to never send padding cells).

Added license/copyrights statements at the top of most files.

router->min and router->max have been merged into a single 'bandwidth'
value. We should make the routerinfo_t reflect this (want to do that,
Mat?)

As the bandwidth increases, and we want to stop sleeping more and more
frequently to send a single cell, cpu usage goes up. At 128kB/s we're
pretty much calling poll with a timeout of 1ms or even 0ms. The current
code takes a timeout of 0-9ms and makes it 10ms. prepare_for_poll()
handles everything that should have happened in the past, so as long as
our buffers don't get too full in that 10ms, we're ok.

Speaking of too full, if you run three servers at 100kB/s with -l debug,
it spends too much time printing debugging messages to be able to keep
up with the cells. The outbuf ultimately fills up and it kills that
connection. If you run with -l err, it works fine up through 500kB/s and
probably beyond. Down the road we'll want to teach it to recognize when
an outbuf is getting full, and back off.


svn:r50

1 files changed, 21 insertions, 29 deletions

diff --git a/src/or/connection_or.c b/src/or/connection_or.c
index 7badd19c93..2542e5f4b2 100644
--- a/src/or/connection_or.c
+++ b/src/or/connection_or.c
@@ -1,3 +1,6 @@
+/* Copyright 2001,2002 Roger Dingledine, Matej Pfajfar. */
+/* See LICENSE for licensing information */
+/* $Id$ */
 
 #include "or.h"
 
@@ -17,7 +20,7 @@ int connection_or_process_inbuf(connection_t *conn) {
     return -1;
   }
 
-  log(LOG_DEBUG,"connection_or_process_inbuf(): state %d.",conn->state);
+//  log(LOG_DEBUG,"connection_or_process_inbuf(): state %d.",conn->state);
 
   switch(conn->state) {
     case OR_CONN_STATE_CLIENT_AUTH_WAIT:
@@ -84,6 +87,7 @@ int connection_or_finished_flushing(connection_t *conn) {
       log(LOG_DEBUG,"connection_or_finished_flushing(): client finished sending nonce.");
       conn_or_init_crypto(conn);
       conn->state = OR_CONN_STATE_OPEN;
+      connection_init_timeval(conn);
       connection_watch_events(conn, POLLIN);
       return 0;
     case OR_CONN_STATE_SERVER_SENDING_AUTH:
@@ -148,7 +152,7 @@ connection_t *connection_or_connect(routerinfo_t *router, RSA *prkey, struct soc
   /* set up conn so it's got all the data we need to remember */
   conn->addr = router->addr, conn->port = router->or_port; /* NOTE we store or_port here always */
   conn->prkey = prkey;
-  conn->min = router->min, conn->max = router->max;
+  conn->bandwidth = router->min; /* kludge, should make a router->bandwidth and use that */
   conn->pkey = router->pkey;
   conn->address = strdup(router->address);
   memcpy(&conn->local,local,sizeof(struct sockaddr_in));
@@ -316,6 +320,7 @@ int or_handshake_op_finished_sending_keys(connection_t *conn) {
   conn_or_init_crypto(conn);
 
   conn->state = OR_CONN_STATE_OPEN;
+  connection_init_timeval(conn);
   connection_watch_events(conn, POLLIN); /* give it a default, tho the ap_handshake call may change it */
   ap_handshake_n_conn_open(conn); /* send the pending onion */
   return 0;
@@ -367,8 +372,7 @@ int or_handshake_client_send_auth(connection_t *conn) {
   char buf[44];
   char cipher[128];
 
-  if (!conn)
-    return -1;
+  assert(conn);
 
   /* generate random keys */
   if(!RAND_bytes(conn->f_session_key,8) ||
@@ -385,11 +389,9 @@ int or_handshake_client_send_auth(connection_t *conn) {
   memcpy(buf+10, (void *)&conn->port, 2); /* remote port */
   memcpy(buf+12,conn->f_session_key,8); /* keys */
   memcpy(buf+20,conn->b_session_key,8);
-  *((uint32_t *)(buf+28)) = htonl(conn->min); /* min link utilisation */
-  *((uint32_t *)(buf+32)) = htonl(conn->max); /* maximum link utilisation */
+  *((uint32_t *)(buf+28)) = htonl(conn->bandwidth); /* max link utilisation */
   log(LOG_DEBUG,"or_handshake_client_send_auth() : Generated first authentication message.");
 
-
   /* encrypt message */
   retval = RSA_public_encrypt(36,buf,cipher,conn->pkey,RSA_PKCS1_PADDING);
   if (retval == -1) /* error */
@@ -429,7 +431,7 @@ int or_handshake_client_send_auth(connection_t *conn) {
 int or_handshake_client_process_auth(connection_t *conn) {
   char buf[128]; /* only 44 of this is expected to be used */
   char cipher[128];
-  uint32_t min,max;
+  uint32_t bandwidth;
   int retval;
 
   assert(conn);
@@ -474,15 +476,10 @@ int or_handshake_client_process_auth(connection_t *conn) {
   log(LOG_DEBUG,"or_handshake_client_process_auth() : Response valid.");
 
   /* update link info */
-  min = *(uint32_t *)(buf+28);
-  max = *(uint32_t *)(buf+32);
-  min = ntohl(min);
-  max = ntohl(max);
+  bandwidth = ntohl(*(uint32_t *)(buf+28));
 
-  if (conn->min > min)
-    conn->min = min;
-  if (conn->max > max)
-    conn->max = max;
+  if (conn->bandwidth > bandwidth)
+    conn->bandwidth = bandwidth;
 
   /* reply is just local addr/port, remote addr/port, nonce */
   memcpy(buf+12, buf+36, 8);
@@ -519,6 +516,7 @@ int or_handshake_client_process_auth(connection_t *conn) {
   log(LOG_DEBUG,"or_handshake_client_process_auth(): Finished sending nonce.");
   conn_or_init_crypto(conn);
   conn->state = OR_CONN_STATE_OPEN;
+  connection_init_timeval(conn);
   connection_watch_events(conn, POLLIN);
   return connection_process_inbuf(conn); /* process the rest of the inbuf */
 
@@ -539,7 +537,7 @@ int or_handshake_server_process_auth(connection_t *conn) {
   uint32_t addr;
   uint16_t port;
 
-  uint32_t min,max;
+  uint32_t bandwidth;
   routerinfo_t *router;
 
   assert(conn);
@@ -593,18 +591,12 @@ int or_handshake_server_process_auth(connection_t *conn) {
   memcpy(conn->f_session_key,buf+20,8);
 
   /* update link info */
-  min = *(uint32_t *)(buf+28);
-  max = *(uint32_t *)(buf+32);
-  min = ntohl(min);
-  max = ntohl(max);
+  bandwidth = ntohl(*(uint32_t *)(buf+28));
 
-  conn->min = router->min;
-  conn->max = router->max;
+  conn->bandwidth = router->min; /* FIXME, should make a router->bandwidth and use that */
 
-  if (conn->min > min)
-    conn->min = min;
-  if (conn->max > max)
-    conn->max = max;
+  if (conn->bandwidth > bandwidth)
+    conn->bandwidth = bandwidth;
 
   /* copy all relevant info to conn */
   conn->addr = router->addr, conn->port = router->or_port;
@@ -622,8 +614,7 @@ int or_handshake_server_process_auth(connection_t *conn) {
 
   /* generate message */
   memcpy(buf+36,conn->nonce,8); /* append the nonce to the end of the message */
-  *(uint32_t *)(buf+28) = htonl(conn->min); /* send min link utilisation */
-  *(uint32_t *)(buf+32) = htonl(conn->max); /* send max link utilisation */
+  *(uint32_t *)(buf+28) = htonl(conn->bandwidth); /* send max link utilisation */
 
   /* encrypt message */
   retval = RSA_public_encrypt(44,buf,cipher,conn->pkey,RSA_PKCS1_PADDING);
@@ -709,6 +700,7 @@ int or_handshake_server_process_nonce(connection_t *conn) {
 
   conn_or_init_crypto(conn);
   conn->state = OR_CONN_STATE_OPEN;
+  connection_init_timeval(conn);
   connection_watch_events(conn, POLLIN);
   return connection_process_inbuf(conn); /* process the rest of the inbuf */