Allow some nesting of ng_iface(4) interfaces and add a configuration knob.

PR:		235500
MFC after:	1 week
This commit is contained in:
Gleb Smirnoff 2019-02-08 06:19:28 +00:00
parent 7cdb0b9d82
commit 938864b71b
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=343895
2 changed files with 23 additions and 2 deletions

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@ -35,7 +35,7 @@
.\" $FreeBSD$
.\" $Whistle: ng_iface.8,v 1.5 1999/01/25 23:46:26 archie Exp $
.\"
.Dd January 12, 2015
.Dd February 6, 2019
.Dt NG_IFACE 4
.Os
.Sh NAME
@ -144,6 +144,17 @@ In case when your graph ends up with some kind of serial line, either
synchronous or modem, the
.Nm
is the right place to turn ALTQ on.
.Sh Nesting
.Nm
supports nesting, a configuration when traffic of one
.Nm
interface flows through the other.
The default maximum allowed nesting level is 2.
It can be changed at runtime setting
.Xr sysctl 8
variable
.Va net.graph.iface.max_nesting
to the desired level of nesting.
.Sh SEE ALSO
.Xr altq 4 ,
.Xr bpf 4 ,
@ -151,6 +162,7 @@ is the right place to turn ALTQ on.
.Xr ng_cisco 4 ,
.Xr ifconfig 8 ,
.Xr ngctl 8
.Xr sysctl
.Sh HISTORY
The
.Nm iface

View File

@ -68,6 +68,7 @@
#include <sys/rmlock.h>
#include <sys/sockio.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <sys/libkern.h>
@ -92,6 +93,13 @@ static MALLOC_DEFINE(M_NETGRAPH_IFACE, "netgraph_iface", "netgraph iface node");
#define M_NETGRAPH_IFACE M_NETGRAPH
#endif
static SYSCTL_NODE(_net_graph, OID_AUTO, iface, CTLFLAG_RW, 0,
"Point to point netgraph interface");
VNET_DEFINE_STATIC(int, ng_iface_max_nest) = 2;
#define V_ng_iface_max_nest VNET(ng_iface_max_nest)
SYSCTL_INT(_net_graph_iface, OID_AUTO, max_nesting, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(ng_iface_max_nest), 0, "Max nested tunnels");
/* This struct describes one address family */
struct iffam {
sa_family_t family; /* Address family */
@ -355,7 +363,8 @@ ng_iface_output(struct ifnet *ifp, struct mbuf *m,
}
/* Protect from deadly infinite recursion. */
error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE, 1);
error = if_tunnel_check_nesting(ifp, m, NGM_IFACE_COOKIE,
V_ng_iface_max_nest);
if (error) {
m_freem(m);
return (error);