Index: sys/compat/linsysfs/linsysfs.c
===================================================================
--- sys/compat/linsysfs/linsysfs.c
+++ sys/compat/linsysfs/linsysfs.c
@@ -2,6 +2,7 @@
  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
  *
  * Copyright (c) 2006 IronPort Systems
+ * Copyright (c) 2017 Carlos Neira cneirabustos@gmail.com
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -53,7 +54,12 @@
 #include <dev/pci/pcivar.h>
 #include <dev/pci/pcireg.h>
 
+#include <sys/ctype.h>
 #include <net/if.h>
+#include <net/if_types.h>
+#include <net/if_var.h>
+#include <net/if_dl.h>
+#include <net/vnet.h>
 
 #include <vm/vm.h>
 #include <vm/pmap.h>
@@ -68,6 +74,9 @@
 #include <compat/linux/linux_mib.h>
 #include <compat/linux/linux_util.h>
 #include <fs/pseudofs/pseudofs.h>
+#include <sys/jail.h>
+
+#define LINUX_IFNAMSIZ          16
 
 struct scsi_host_queue {
 	TAILQ_ENTRY(scsi_host_queue) scsi_host_next;
@@ -85,6 +94,201 @@
 	return (int)strtol(str, (char **)NULL, 10);
 }
 
+/*
+* Filler function for sys/class/net/<iface> 
+* Only 2 interfaces are created eth0 and lo and they expose the following files
+* address, addr_len, flags, ifindex, mty, tx_queue_len and type.
+*/
+#define ETHERADDRL 6
+#define IFP_IS_ETH(ifp) (ifp->if_type == IFT_ETHER)
+
+static struct ifnet *
+ifname_linux_to_bsd(struct thread *td, const char *lxname, char *bsdname)
+{
+	struct ifnet *ifp;
+	int len, unit;
+	char *ep;
+	int is_eth, index;
+
+	for (len = 0; len < LINUX_IFNAMSIZ; ++len)
+		if (!isalpha(lxname[len]))
+			break;
+	if (len == 0 || len == LINUX_IFNAMSIZ)
+		return (NULL);
+	unit = (int)strtoul(lxname + len, &ep, 10);
+	if (ep == NULL || ep == lxname + len || ep >= lxname + LINUX_IFNAMSIZ)
+		return (NULL);
+	index = 0;
+	is_eth = (len == 3 && !strncmp(lxname, "eth", len)) ? 1 : 0;
+	CURVNET_SET(TD_TO_VNET(td));
+	IFNET_RLOCK();
+	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
+		/*
+		 * Allow Linux programs to use FreeBSD names. Don't presume
+		 * we never have an interface named "eth", so don't make
+		 * the test optional based on is_eth.
+		 */
+		if (strncmp(ifp->if_xname, lxname, LINUX_IFNAMSIZ) == 0)
+			break;
+		if (is_eth && IFP_IS_ETH(ifp) && unit == index++)
+			break;
+	}
+	IFNET_RUNLOCK();
+	CURVNET_RESTORE();
+	if (ifp != NULL)
+		strlcpy(bsdname, ifp->if_xname, IFNAMSIZ);
+	
+	return (ifp);
+}
+
+static int
+linsysfs_ifnet_addr(PFS_FILL_ARGS) {
+	struct ifnet* ifp;
+	char bsdname[IFNAMSIZ+1];
+	uint8_t*  address;
+	if (!memcmp((const char*)pn->pn_parent->pn_name, "lo", 2)) {
+		sbuf_printf (sb, "00:00:00:00:00:00\n");
+		return (0);
+	} else {
+		ifp = ifname_linux_to_bsd(curthread,
+					  (const char*)pn->pn_parent->pn_name,
+					  bsdname);
+		if (!ifp) {
+			sbuf_printf (sb, "00:00:00:00:00:00\n");
+			return (0);
+		}
+		address = IF_LLADDR(ifp);
+		sbuf_printf (sb, "%02hhx:%02hhx:%02hhx:%02hhx:%02hhx:%02hhx\n",
+			     address[0], address[1], address[2],
+			     address[3], address[4], address[5]);
+		return (0);
+	}
+}
+
+static int
+linsysfs_ifnet_addrlen(PFS_FILL_ARGS) {
+	sbuf_printf(sb, "6\n");
+	return (0);
+}
+
+static int
+linsysfs_ifnet_flags(PFS_FILL_ARGS) {
+	int buf;
+	struct ifnet* ifp;
+	char bsdname[IFNAMSIZ+1];
+	if (!memcmp((const char*)pn->pn_parent->pn_name, "eth", 3)) {
+		ifp = ifname_linux_to_bsd(curthread,
+					  (const char*)pn->pn_parent->pn_name,
+					  bsdname);
+		buf = ifp->if_flags & (IFF_UP | IFF_BROADCAST | IFF_DEBUG |
+				       IFF_LOOPBACK | IFF_POINTOPOINT |
+				       IFF_DRV_RUNNING | IFF_NOARP |
+				       IFF_PROMISC | IFF_ALLMULTI);
+		buf |= 0x1000;
+		sbuf_printf(sb, "0x%x\n", buf);
+	} else {
+		sbuf_printf(sb, "0x9\n");
+	}
+	return (0);
+}
+
+static int
+linsysfs_ifnet_ifindex(PFS_FILL_ARGS) {
+	struct ifnet* ifp;
+	char bsdname[IFNAMSIZ+1];
+	if (!memcmp((const char*)pn->pn_parent->pn_name, "eth", 3)) {
+		ifp = ifname_linux_to_bsd(curthread,
+					  (const char*)pn->pn_parent->pn_name, bsdname);
+		sbuf_printf(sb, "%u\n", ifp->if_index);
+	} else {
+		sbuf_printf(sb, "1\n");
+	}
+	return (0);
+}
+
+static int
+linsysfs_ifnet_mtu(PFS_FILL_ARGS) {
+	struct ifnet* ifp;
+	char bsdname[IFNAMSIZ+1];
+	if (!memcmp((const char*)pn->pn_parent->pn_name, "lo", 2)) {
+		sbuf_printf(sb, "65536\n");
+	} else {
+		ifp = ifname_linux_to_bsd(curthread,
+					  (const char*)pn->pn_parent->pn_name,
+					  bsdname);
+		sbuf_printf(sb, "%u\n", ifp->if_mtu);
+	}
+	return (0);
+}
+
+static int
+linsysfs_ifnet_tx_queue_len(PFS_FILL_ARGS) {
+	sbuf_printf(sb, "1000\n");
+	return (0);
+}
+
+static int
+linsysfs_ifnet_type(PFS_FILL_ARGS) {
+	if (!memcmp((const char*)pn->pn_parent->pn_name, "lo", 2))
+		sbuf_printf(sb, "772\n");
+	else
+		sbuf_printf(sb, "2\n");
+	return (0);
+}
+
+static void
+linsysfs_listnics(struct pfs_node *dir)
+{
+	struct pfs_node *nic;
+	struct pfs_node *lo;
+
+	nic = pfs_create_dir (dir, "eth0", NULL, NULL, NULL, 0);
+
+	pfs_create_file(nic, "address", &linsysfs_ifnet_addr,
+			NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "addr_len", &linsysfs_ifnet_addrlen,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "flags", &linsysfs_ifnet_flags,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "ifindex", &linsysfs_ifnet_ifindex,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "mtu", &linsysfs_ifnet_mtu,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "tx_queue_len", &linsysfs_ifnet_tx_queue_len,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(nic, "type", &linsysfs_ifnet_type,
+			 NULL, NULL, NULL, PFS_RD);
+
+	lo = pfs_create_dir(dir, "lo", NULL, NULL, NULL, 0);
+
+	pfs_create_file(lo, "address", &linsysfs_ifnet_addr,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file (lo, "addr_len", &linsysfs_ifnet_addrlen,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file (lo, "flags", &linsysfs_ifnet_flags,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file (lo, "ifindex", &linsysfs_ifnet_ifindex,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file (lo, "mtu", &linsysfs_ifnet_mtu,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(lo, "tx_queue_len", &linsysfs_ifnet_tx_queue_len,
+			 NULL, NULL, NULL, PFS_RD);
+
+	pfs_create_file(lo, "type", &linsysfs_ifnet_type,
+			 NULL, NULL, NULL, PFS_RD);
+}
+
 /*
  * Filler function for proc_name
  */
@@ -496,6 +700,7 @@
 	struct pfs_node *drm;
 	struct pfs_node *pci;
 	struct pfs_node *scsi;
+	struct pfs_node *net;
 	struct pfs_node *devdir, *chardev;
 	devclass_t devclass;
 	device_t dev;
@@ -509,6 +714,9 @@
 	scsi = pfs_create_dir(class, "scsi_host", NULL, NULL, NULL, 0);
 	drm = pfs_create_dir(class, "drm", NULL, NULL, NULL, 0);
 
+	/* /sys/class/net/.. */
+	net = pfs_create_dir(class, "net", NULL, NULL, NULL, 0);
+
 	/* /sys/dev/... */
 	devdir = pfs_create_dir(root, "dev", NULL, NULL, NULL, 0);
 	chardev = pfs_create_dir(devdir, "char", NULL, NULL, NULL, 0);
@@ -535,6 +743,7 @@
 	    NULL, NULL, NULL, PFS_RD);
 
 	linsysfs_listcpus(cpu);
+	linsysfs_listnics(net);
 
 	return (0);
 }