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Commit 27cf76fe authored by Petr Machata's avatar Petr Machata Committed by David S. Miller
Browse files

mlxsw: spectrum_span: Support mirror to gretap 



When a user requests mirror from a mlxsw physical port (possibly based
on an ACL match) to a gretap netdevice, the driver needs to resolve the
request to a particular physical port that the mirrored packets will
egress through, and a suite of configuration keys (importantly, IP and
MAC addresses). That means calling into routing and neighbor kernel code
to simulate the decisions made by the system for packets passing through
a gretap netdevice.

Add a new instance of mlxsw_sp_span_entry_ops to support this.

Signed-off-by: default avatarPetr Machata <petrm@mellanox.com>
Reviewed-by: default avatarIdo Schimmel <idosch@mellanox.com>
Signed-off-by: default avatarJiri Pirko <jiri@mellanox.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 52a6444c

drivers/net/ethernet/mellanox/mlxsw/Kconfig

+2 −0
Original line number Diff line number Diff line
@@ -78,6 +78,8 @@ config MLXSW_SPECTRUM 
	depends on IPV6 || IPV6=n

	select PARMAN

	select MLXFW

	depends on NET_IPGRE

	depends on !(MLXSW_CORE=y && NET_IPGRE=m)

	default m

	---help---

	  This driver supports Mellanox Technologies Spectrum Ethernet

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.c

+165 −2
Original line number Diff line number Diff line 
/*

 * drivers/net/ethernet/mellanox/mlxsw/mlxsw_span.c

 * Copyright (c) 2018 Mellanox Technologies. All rights reserved.

 * Copyright (c) 2018 Petr Machata <petrm@mellanox.com>

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:
@@ -32,9 +33,12 @@ 
 */



#include <linux/list.h>

#include <net/arp.h>

#include <net/gre.h>



#include "spectrum.h"

#include "spectrum_span.h"

#include "spectrum_ipip.h"



int mlxsw_sp_span_init(struct mlxsw_sp *mlxsw_sp)

{
@@ -127,17 +131,176 @@ struct mlxsw_sp_span_entry_ops mlxsw_sp_span_entry_ops_phys = { 
	.deconfigure = mlxsw_sp_span_entry_phys_deconfigure,

};



static struct net_device *

mlxsw_sp_span_gretap4_route(const struct net_device *to_dev,

			    __be32 *saddrp, __be32 *daddrp)

{

	struct ip_tunnel *tun = netdev_priv(to_dev);

	struct net_device *dev = NULL;

	struct ip_tunnel_parm parms;

	struct rtable *rt = NULL;

	struct flowi4 fl4;



	/* We assume "dev" stays valid after rt is put. */

	ASSERT_RTNL();



	parms = mlxsw_sp_ipip_netdev_parms4(to_dev);

	ip_tunnel_init_flow(&fl4, parms.iph.protocol, *daddrp, *saddrp,

			    0, 0, parms.link, tun->fwmark);



	rt = ip_route_output_key(tun->net, &fl4);

	if (IS_ERR(rt))

		return NULL;



	if (rt->rt_type != RTN_UNICAST)

		goto out;



	dev = rt->dst.dev;

	*saddrp = fl4.saddr;

	*daddrp = rt->rt_gateway;



out:

	ip_rt_put(rt);

	return dev;

}



static int mlxsw_sp_span_dmac(struct neigh_table *tbl,

			      const void *pkey,

			      struct net_device *l3edev,

			      unsigned char dmac[ETH_ALEN])

{

	struct neighbour *neigh = neigh_lookup(tbl, pkey, l3edev);

	int err = 0;



	if (!neigh) {

		neigh = neigh_create(tbl, pkey, l3edev);

		if (IS_ERR(neigh))

			return PTR_ERR(neigh);

	}



	neigh_event_send(neigh, NULL);



	read_lock_bh(&neigh->lock);

	if ((neigh->nud_state & NUD_VALID) && !neigh->dead)

		memcpy(dmac, neigh->ha, ETH_ALEN);

	else

		err = -ENOENT;

	read_unlock_bh(&neigh->lock);



	neigh_release(neigh);

	return err;

}



static int

mlxsw_sp_span_entry_unoffloadable(struct mlxsw_sp_span_parms *sparmsp)

{

	sparmsp->dest_port = NULL;

	return 0;

}



static int

mlxsw_sp_span_entry_tunnel_parms_common(struct net_device *l3edev,

					union mlxsw_sp_l3addr saddr,

					union mlxsw_sp_l3addr daddr,

					union mlxsw_sp_l3addr gw,

					__u8 ttl,

					struct neigh_table *tbl,

					struct mlxsw_sp_span_parms *sparmsp)

{

	unsigned char dmac[ETH_ALEN];



	if (mlxsw_sp_l3addr_is_zero(gw))

		gw = daddr;



	if (!l3edev || !mlxsw_sp_port_dev_check(l3edev) ||

	    mlxsw_sp_span_dmac(tbl, &gw, l3edev, dmac))

		return mlxsw_sp_span_entry_unoffloadable(sparmsp);



	sparmsp->dest_port = netdev_priv(l3edev);

	sparmsp->ttl = ttl;

	memcpy(sparmsp->dmac, dmac, ETH_ALEN);

	memcpy(sparmsp->smac, l3edev->dev_addr, ETH_ALEN);

	sparmsp->saddr = saddr;

	sparmsp->daddr = daddr;

	return 0;

}



static int

mlxsw_sp_span_entry_gretap4_parms(const struct net_device *to_dev,

				  struct mlxsw_sp_span_parms *sparmsp)

{

	struct ip_tunnel_parm tparm = mlxsw_sp_ipip_netdev_parms4(to_dev);

	union mlxsw_sp_l3addr saddr = { .addr4 = tparm.iph.saddr };

	union mlxsw_sp_l3addr daddr = { .addr4 = tparm.iph.daddr };

	bool inherit_tos = tparm.iph.tos & 0x1;

	bool inherit_ttl = !tparm.iph.ttl;

	union mlxsw_sp_l3addr gw = daddr;

	struct net_device *l3edev;



	if (!(to_dev->flags & IFF_UP) ||

	    /* Reject tunnels with GRE keys, checksums, etc. */

	    tparm.i_flags || tparm.o_flags ||

	    /* Require a fixed TTL and a TOS copied from the mirrored packet. */

	    inherit_ttl || !inherit_tos ||

	    /* A destination address may not be "any". */

	    mlxsw_sp_l3addr_is_zero(daddr))

		return mlxsw_sp_span_entry_unoffloadable(sparmsp);



	l3edev = mlxsw_sp_span_gretap4_route(to_dev, &saddr.addr4, &gw.addr4);

	return mlxsw_sp_span_entry_tunnel_parms_common(l3edev, saddr, daddr, gw,

						       tparm.iph.ttl,

						       &arp_tbl, sparmsp);

}



static int

mlxsw_sp_span_entry_gretap4_configure(struct mlxsw_sp_span_entry *span_entry,

				      struct mlxsw_sp_span_parms sparms)

{

	struct mlxsw_sp_port *dest_port = sparms.dest_port;

	struct mlxsw_sp *mlxsw_sp = dest_port->mlxsw_sp;

	u8 local_port = dest_port->local_port;

	char mpat_pl[MLXSW_REG_MPAT_LEN];

	int pa_id = span_entry->id;



	/* Create a new port analayzer entry for local_port. */

	mlxsw_reg_mpat_pack(mpat_pl, pa_id, local_port, true,

			    MLXSW_REG_MPAT_SPAN_TYPE_REMOTE_ETH_L3);

	mlxsw_reg_mpat_eth_rspan_l2_pack(mpat_pl,

				    MLXSW_REG_MPAT_ETH_RSPAN_VERSION_NO_HEADER,

				    sparms.dmac, false);

	mlxsw_reg_mpat_eth_rspan_l3_ipv4_pack(mpat_pl,

					      sparms.ttl, sparms.smac,

					      be32_to_cpu(sparms.saddr.addr4),

					      be32_to_cpu(sparms.daddr.addr4));



	return mlxsw_reg_write(mlxsw_sp->core, MLXSW_REG(mpat), mpat_pl);

}



static void

mlxsw_sp_span_entry_gretap4_deconfigure(struct mlxsw_sp_span_entry *span_entry)

{

	mlxsw_sp_span_entry_deconfigure_common(span_entry,

					MLXSW_REG_MPAT_SPAN_TYPE_REMOTE_ETH_L3);

}



static const struct mlxsw_sp_span_entry_ops mlxsw_sp_span_entry_ops_gretap4 = {

	.can_handle = is_gretap_dev,

	.parms = mlxsw_sp_span_entry_gretap4_parms,

	.configure = mlxsw_sp_span_entry_gretap4_configure,

	.deconfigure = mlxsw_sp_span_entry_gretap4_deconfigure,

};



static const

struct mlxsw_sp_span_entry_ops *const mlxsw_sp_span_entry_types[] = {

	&mlxsw_sp_span_entry_ops_phys,

	&mlxsw_sp_span_entry_ops_gretap4,

};



static int

mlxsw_sp_span_entry_nop_parms(const struct net_device *to_dev,

			      struct mlxsw_sp_span_parms *sparmsp)

{

	sparmsp->dest_port = NULL;

	return 0;

	return mlxsw_sp_span_entry_unoffloadable(sparmsp);

}



static int

drivers/net/ethernet/mellanox/mlxsw/spectrum_span.h

+8 −0
Original line number Diff line number Diff line
@@ -35,6 +35,9 @@ 
#define _MLXSW_SPECTRUM_SPAN_H



#include <linux/types.h>

#include <linux/if_ether.h>



#include "spectrum_router.h"



struct mlxsw_sp;

struct mlxsw_sp_port;
@@ -52,6 +55,11 @@ struct mlxsw_sp_span_inspected_port { 


struct mlxsw_sp_span_parms {

	struct mlxsw_sp_port *dest_port; /* NULL for unoffloaded SPAN. */

	unsigned int ttl;

	unsigned char dmac[ETH_ALEN];

	unsigned char smac[ETH_ALEN];

	union mlxsw_sp_l3addr daddr;

	union mlxsw_sp_l3addr saddr;

};



struct mlxsw_sp_span_entry_ops;