From: Fredrik Tolf <fredrik@dolda2000.com>
Date: Sun, 24 Feb 2008 05:05:23 +0000 (+0100)
Subject: Made the UI reader a bit more resilient to faulty clients.
X-Git-Tag: 1.2~21
X-Git-Url: http://dolda2000.com/gitweb/?p=doldaconnect.git;a=commitdiff_plain;h=821e3843c3fd59ed4806b4e1c40b9ade078c2f61

Made the UI reader a bit more resilient to faulty clients.
---

diff --git a/daemon/ui.c b/daemon/ui.c
index 9c63071..01e1a52 100644
--- a/daemon/ui.c
+++ b/daemon/ui.c
@@ -118,6 +118,7 @@ struct uidata
     struct uidata *next, *prev;
     struct socket *sk;
     struct qcommand *queue, *queuelast;
+    size_t queuesize;
     struct authhandle *auth;
     int close;
     union
@@ -704,7 +705,7 @@ static void cmd_lspeers(struct socket *sk, struct uidata *data, int argc, wchar_
     }
     if(fn->peers == NULL)
     {
-	sq(sk, 0, L"201", L"No peers avaiable", NULL);
+	sq(sk, 0, L"201", L"No peers available", NULL);
     } else {
 	for(peer = btreeiter(fn->peers); peer != NULL; peer = npeer)
 	{
@@ -1421,6 +1422,7 @@ static struct qcommand *unlinkqcmd(struct uidata *data)
     qcmd = data->queue;
     if(qcmd != NULL)
     {
+	data->queuesize--;
 	data->queue = qcmd->next;
 	if(qcmd == data->queuelast)
 	    data->queuelast = qcmd->next;
@@ -1611,6 +1613,7 @@ static void queuecmd(struct uidata *data, struct command *cmd, int argc, wchar_t
     data->queuelast = new;
     if(data->queue == NULL)
 	data->queue = new;
+    data->queuesize++;
 }
 
 static struct uidata *newuidata(struct socket *sk)
@@ -1803,6 +1806,11 @@ static void uiread(struct socket *sk, struct uidata *data)
 	    break;
 	}
     }
+    if(data->cbdata > 16384)
+    {
+	/* Kill clients that send us unreasonably long lines */
+	data->close = 1;
+    }
 }
 
 static void uierror(struct socket *sk, int err, struct uidata *data)
@@ -2400,6 +2408,15 @@ static int run(void)
 	    freequeuecmd(qcmd);
 	    return(1);
 	}
+	if(data->queuesize > 10)
+	{
+	    /* Clients should not be queue up commands at all, since
+	     * they should not send a new command before receiving a
+	     * reply to the previous command. Therefore, we
+	     * mercilessly massacre clients which are stacking up too
+	     * many commands. */
+	    data->close = 1;
+	}
     }
     return(0);
 }