Changeset 626

Timestamp:

11/07/08 22:43:57 (4 months ago)

Author:

markdoliner

Message:

* Change rate.c to reset the start of the window when rate_add() is

called rather than when rate_check() is called. This fixes a problem
where we would always eventually hit the rate limit because we
weren't actually respecting the window size.

* Change c2s to close a client connection if it exceeds the rate limit
* Change c2s to log to the normal log and not the debug log when a user

is throttled.

* Change c2s to only try to read the amount of data up to the rate

limit--never more.

* Change c2s to call rate_add() to keep track of how much data each

client sends.

Location:

trunk

Files:

• c2s/c2s.c (modified) (2 diffs)
• ChangeLog (modified) (1 diff)
• util/rate.c (modified) (4 diffs)
• util/util.h (modified) (1 diff)

trunk/c2s/c2s.c

@@ -59 +59 @@
                     }
 
-                    log_debug(ZONE, "%d is throttled, delaying read", sess->fd->fd);
-
-                    buf->len = 0;
-                    return 0;
+                    log_write(sess->c2s->log, LOG_NOTICE, "%d is throttled, disconnecting", sess->fd->fd);
+
+                    /* Disconnect the user.  Ideally we would just stop
+                       reading from their socket until the throttle time
+                       expires.  But that's difficult. */
+                    sx_kill(s);
+                    return -1;
                 }
 
@@ -71 +74 @@
             }
 
+            /* no limit, just read as much as we can */
+            else
+                rlen = buf->len;
+
             /* do the read */
-            len = recv(sess->fd->fd, buf->data, buf->len, 0);
+            len = recv(sess->fd->fd, buf->data, rlen, 0);
+
+            /* update rate limits */
+            if(sess->rate != NULL)
+                rate_add(sess->rate, len);
 
             if(len < 0) {

trunk/ChangeLog

@@ +1 @@
+2008-07-11 Mark Doliner <mark@meebo.com>
+        * Fix c2s's byte rate limiting.
+        * Make c2s's connection rate limiting and router's byte rate limiting
+          work better.
+
 2008-07-09 Mark Doliner <mark@meebo.com>
         * Add a note to sm.xml that our Berkeley DB storage module doesn't

trunk/util/rate.c

@@ -48 +48 @@
 void rate_add(rate_t rt, int count)
 {
+    time_t now;
+
+    now = time(NULL);
+
+    /* rate expired */
+    if(now - rt->time >= rt->seconds)
+        rate_reset(rt);
+
     rt->count += count;
 
     /* first event, so set the time */
     if(rt->time == 0)
-        rt->time = time(NULL);
+        rt->time = now;
 
     /* uhoh, they stuffed up */
     if(rt->count >= rt->total)
-        rt->bad = time(NULL);
+        rt->bad = now;
 }
 
@@ -70 +78 @@
 int rate_check(rate_t rt)
 {
-    time_t now;
-
     /* not tracking */
     if(rt->time == 0)
@@ -80 +86 @@
         return 1;
 
-    now = time(NULL);
-
     /* currently bad */
     if(rt->bad != 0)
     {
         /* wait over, they're good again */
-        if(now - rt->bad >= rt->wait)
+        if(time(NULL) - rt->bad >= rt->wait)
         {
             rate_reset(rt);
@@ -96 +100 @@
     }
 
-    /* rate expired */
-    if(now - rt->time >= rt->seconds)
-    {
-        rate_reset(rt);
-        return 1;
-    }
-
     /* they're inside the time, and not bad yet */
     return 1;

trunk/util/util.h

@@ -268 +268 @@
 JABBERD2_API void        rate_free(rate_t rt);
 JABBERD2_API void        rate_reset(rate_t rt);
+
+/**
+ * Add a number of events to the counter.  This takes care of moving
+ * the sliding window, if we've moved outside the previous window.
+ */
 JABBERD2_API void        rate_add(rate_t rt, int count);
+
+/**
+ * @return The amount of events we have left before we hit the rate
+ *         limit.  This could be number of bytes, or number of
+ *         connection attempts, etc.
+ */
 JABBERD2_API int         rate_left(rate_t rt);
-JABBERD2_API int         rate_check(rate_t rt);          /* 1 == good, 0 == bad */
+
+/**
+ * @return 1 if we're under the rate limit and everything is fine or
+ *         0 if the rate limit has been exceeded and we should throttle
+ *         something.
+ */
+JABBERD2_API int         rate_check(rate_t rt);
 
 /*