svn commit: r267094 - stable/9/sys/netgraph

[Alexander Motin]

Author: mav
Date: Thu Jun  5 05:58:54 2014
New Revision: 267094
URL: http://svnweb.freebsd.org/changeset/base/267094

Log:
  MFC r266538:
  Make ng_mppc to not disable the node in case of multiple packet loss.
  Quite often it can be just packet reorder, and killing link in such case
  is inconvenient.  Add few sysctl's to control that behavior.
  
  PR:		kern/182212
  Submitted by:	Eugene Grosbein <egrosbein at rdtc.ru>
  Approved by:	re (glebius)

Modified:
  stable/9/sys/netgraph/ng_mppc.c
Directory Properties:
  stable/9/   (props changed)
  stable/9/sys/   (props changed)

Modified: stable/9/sys/netgraph/ng_mppc.c
==============================================================================
--- stable/9/sys/netgraph/ng_mppc.c	Thu Jun  5 05:36:55 2014	(r267093)
+++ stable/9/sys/netgraph/ng_mppc.c	Thu Jun  5 05:58:54 2014	(r267094)
@@ -55,6 +55,7 @@
 #include <sys/malloc.h>
 #include <sys/endian.h>
 #include <sys/errno.h>
+#include <sys/sysctl.h>
 #include <sys/syslog.h>
 
 #include <netgraph/ng_message.h>
@@ -107,6 +108,23 @@ static MALLOC_DEFINE(M_NETGRAPH_MPPC, "n
  */
 #define MPPE_MAX_REKEY		1000
 
+SYSCTL_NODE(_net_graph, OID_AUTO, mppe, CTLFLAG_RW, 0, "MPPE");
+
+static int mppe_block_on_max_rekey = 0;
+TUNABLE_INT("net.graph.mppe.block_on_max_rekey", &mppe_block_on_max_rekey);
+SYSCTL_INT(_net_graph_mppe, OID_AUTO, block_on_max_rekey, CTLFLAG_RW,
+    &mppe_block_on_max_rekey, 0, "Block node on max MPPE key re-calculations");
+
+static int mppe_log_max_rekey = 1;
+TUNABLE_INT("net.graph.mppe.log_max_rekey", &mppe_log_max_rekey);
+SYSCTL_INT(_net_graph_mppe, OID_AUTO, log_max_rekey, CTLFLAG_RW,
+    &mppe_log_max_rekey, 0, "Log max MPPE key re-calculations event");
+
+static int mppe_max_rekey = MPPE_MAX_REKEY;
+TUNABLE_INT("net.graph.mppe.max_rekey", &mppe_max_rekey);
+SYSCTL_INT(_net_graph_mppe, OID_AUTO, max_rekey, CTLFLAG_RW,
+    &mppe_max_rekey, 0, "Maximum number of MPPE key re-calculations");
+
 /* MPPC packet header bits */
 #define MPPC_FLAG_FLUSHED	0x8000		/* xmitter reset state */
 #define MPPC_FLAG_RESTART	0x4000		/* compress history restart */
@@ -646,12 +664,23 @@ ng_mppc_decompress(node_p node, struct m
 			/* How many times are we going to have to re-key? */
 			rekey = ((d->cfg.bits & MPPE_STATELESS) != 0) ?
 			    numLost : (numLost / (MPPE_UPDATE_MASK + 1));
-			if (rekey > MPPE_MAX_REKEY) {
-				log(LOG_ERR, "%s: too many (%d) packets"
-				    " dropped, disabling node %p!",
-				    __func__, numLost, node);
+			if (rekey > mppe_max_rekey) {
+			    if (mppe_block_on_max_rekey) {
+				if (mppe_log_max_rekey) {
+				    log(LOG_ERR, "%s: too many (%d) packets"
+					" dropped, disabling node %p!\n",
+					__func__, numLost, node);
+				}
 				priv->recv.cfg.enable = 0;
 				goto failed;
+			    } else {
+				if (mppe_log_max_rekey) {
+				    log(LOG_ERR, "%s: %d packets"
+					" dropped, node %p\n",
+					__func__, numLost, node);
+				}
+				goto failed;
+			    }
 			}
 
 			/* Re-key as necessary to catch up to peer */