drivers: eth: Add ethernet driver for native posix arch

This creates zeth network interface in your host and allows user
to send and receive data sent to this network interface.

Fixes #6007

Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>

boards/posix/native_posix/doc/board.rst

@@ -389,6 +389,14 @@ The following peripherals are currently provided with this board:
   and provides interrupt priorities. Interrupts can be individually masked or
   unmasked. SW interrupts are also supported.
 
+**Ethernet driver**:
+  A simple TAP based ethernet driver is provided. The driver will create
+  a **zeth** network interface to the host system. One can communicate with
+  Zephyr via this network interface. Multiple TAP based network interfaces can
+  be created if needed. The IP address configuration can be specified for each
+  network interface instance.
+  See :option:`CONFIG_ETH_NATIVE_POSIX_SETUP_SCRIPT` option for more details.
+
 Shell support
 *************
 

drivers/ethernet/CMakeLists.txt

@@ -6,3 +6,7 @@ zephyr_sources_ifdef(CONFIG_ETH_DW		eth_dw.c)
 zephyr_sources_ifdef(CONFIG_ETH_ENC28J60	eth_enc28j60.c)
 zephyr_sources_ifdef(CONFIG_ETH_MCUX		eth_mcux.c)
 zephyr_sources_ifdef(CONFIG_ETH_STM32_HAL	eth_stm32_hal.c)
+zephyr_sources_ifdef(CONFIG_ETH_NATIVE_POSIX
+	eth_native_posix.c
+	eth_native_posix_adapt.c
+	)

drivers/ethernet/Kconfig

@@ -39,5 +39,6 @@ source "drivers/ethernet/Kconfig.mcux"
 source "drivers/ethernet/Kconfig.dw"
 source "drivers/ethernet/Kconfig.sam_gmac"
 source "drivers/ethernet/Kconfig.stm32_hal"
+source "drivers/ethernet/Kconfig.native_posix"
 
 endmenu

drivers/ethernet/Kconfig.native_posix

@@ -0,0 +1,67 @@
+# Kconfig - Native posix ethernet driver configuration options
+
+# Copyright (c) 2018 Intel Corporation
+#
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig ETH_NATIVE_POSIX
+	bool
+	prompt "Native Posix Ethernet driver"
+	depends on ARCH_POSIX
+	select NET_L2_ETHERNET
+	default n
+	help
+	  Enable native posix ethernet driver. Note, this driver is run inside
+	  a process in your host system.
+
+if ETH_NATIVE_POSIX
+config ETH_NATIVE_POSIX_SETUP_SCRIPT
+	string "Host setup script"
+	default "${ZEPHYR_BASE}/samples/net/eth_native_posix/net_setup_host"
+	help
+	  This option sets the name of the script that is run when the host TAP
+	  network interface is created. The script should setup IP addresses
+	  etc. for the host TAP network interface.
+	  The default script accepts following options:
+	  -i|--interface <network interface name>, default is zeth
+	  -f|--file <config file name>, default is net_setup_host.conf
+	  If needed, you can add these options to this script name option.
+	  Note that the driver will add -i option with the value of
+	  CONFIG_ETH_NATIVE_POSIX_DRV_NAME option to the end of the options
+	  list when calling the host setup script.
+
+config ETH_NATIVE_POSIX_DRV_NAME
+	string "Ethernet driver name"
+	default "zeth"
+	help
+	  This option sets the driver name and name of the network interface
+	  in your host system.
+
+config ETH_NATIVE_POSIX_DEV_NAME
+	string "Host ethernet TUN/TAP device name"
+	default "/dev/net/tun"
+	help
+	  This option sets the TUN/TAP device name in your host system.
+
+config ETH_NATIVE_POSIX_RANDOM_MAC
+	bool "Random MAC address"
+	depends on ENTROPY_GENERATOR
+	default y
+	help
+	  Generate a random MAC address dynamically.
+
+if ! ETH_NATIVE_POSIX_RANDOM_MAC
+
+config	ETH_NATIVE_POSIX_MAC_ADDR
+	string "MAC address for the interface"
+	default ""
+	help
+	  Specify a MAC address for the ethernet interface in the form of
+	  six hex 8-bit chars separated by colons (e.g.:
+	  aa:33:cc:22:e2:c0).  The default is an empty string, which
+	  means the code will make 00:00:5E:00:53:XX, where XX will be
+	  random.
+
+endif
+
+endif

drivers/ethernet/eth_native_posix.c

@@ -0,0 +1,239 @@
+/*
+ * Copyright (c) 2018 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ *
+ * Ethernet driver for native posix board. This is meant for network
+ * connectivity between host and Zephyr.
+ */
+
+#define SYS_LOG_DOMAIN "eth-posix"
+#define SYS_LOG_LEVEL CONFIG_SYS_LOG_ETHERNET_LEVEL
+
+#include <logging/sys_log.h>
+#include <stdio.h>
+
+#include <kernel.h>
+
+#include <stdbool.h>
+#include <errno.h>
+#include <stddef.h>
+
+#include <net/net_pkt.h>
+#include <net/net_core.h>
+#include <net/net_if.h>
+#include <net/ethernet.h>
+
+#include "eth_native_posix_priv.h"
+
+#if defined(CONFIG_NET_L2_ETHERNET)
+#define _ETH_L2_LAYER ETHERNET_L2
+#define _ETH_L2_CTX_TYPE NET_L2_GET_CTX_TYPE(ETHERNET_L2)
+#define _ETH_MTU 1500
+#endif
+
+#define NET_BUF_TIMEOUT MSEC(10)
+
+struct eth_context {
+	u8_t recv[_ETH_MTU + sizeof(struct net_eth_hdr)];
+	u8_t send[_ETH_MTU + sizeof(struct net_eth_hdr)];
+	u8_t mac_addr[6];
+	struct net_linkaddr ll_addr;
+	struct net_if *iface;
+	const char *if_name;
+	int dev_fd;
+	bool init_done;
+	bool status;
+};
+
+NET_STACK_DEFINE(RX_ZETH, eth_rx_stack,
+		 CONFIG_ARCH_POSIX_RECOMMENDED_STACK_SIZE,
+		 CONFIG_ARCH_POSIX_RECOMMENDED_STACK_SIZE);
+static struct k_thread rx_thread_data;
+
+/* TODO: support multiple interfaces */
+static struct eth_context eth_context_data;
+
+static struct eth_context *get_context(struct net_if *iface)
+{
+	return net_if_get_device(iface)->driver_data;
+}
+
+static int eth_send(struct net_if *iface, struct net_pkt *pkt)
+{
+	struct eth_context *ctx = get_context(iface);
+	struct net_buf *frag;
+	int count = 0;
+
+	/* First fragment contains link layer (Ethernet) headers.
+	 */
+	count = net_pkt_ll_reserve(pkt) + pkt->frags->len;
+	memcpy(ctx->send, net_pkt_ll(pkt), count);
+
+	/* Then the remaining data */
+	frag = pkt->frags->frags;
+	while (frag) {
+		memcpy(ctx->send + count, frag->data, frag->len);
+		count += frag->len;
+		frag = frag->frags;
+	}
+
+	net_pkt_unref(pkt);
+
+	SYS_LOG_DBG("Send pkt %p len %d", pkt, count);
+
+	eth_write_data(ctx->dev_fd, ctx->send, count);
+
+	return 0;
+}
+
+static int eth_init(struct device *dev)
+{
+	ARG_UNUSED(dev);
+	return 0;
+}
+
+static struct net_linkaddr *eth_get_mac(struct eth_context *ctx)
+{
+	ctx->ll_addr.addr = ctx->mac_addr;
+	ctx->ll_addr.len = sizeof(ctx->mac_addr);
+
+	return &ctx->ll_addr;
+}
+
+static int read_data(struct eth_context *ctx, int fd)
+{
+	struct net_pkt *pkt;
+	struct net_buf *frag;
+	int ret;
+
+	ret = eth_read_data(fd, ctx->recv, sizeof(ctx->recv));
+	if (ret <= 0) {
+		return 0;
+	}
+
+	pkt = net_pkt_get_reserve_rx(0, NET_BUF_TIMEOUT);
+	if (!pkt) {
+		return -ENOMEM;
+	}
+
+	do {
+		int count = 0;
+
+		frag = net_pkt_get_frag(pkt, NET_BUF_TIMEOUT);
+		if (!frag) {
+			net_pkt_unref(pkt);
+			return -ENOMEM;
+		}
+
+		net_pkt_frag_add(pkt, frag);
+
+		net_buf_add_mem(frag, ctx->recv + count,
+				min(net_buf_tailroom(frag), ret));
+		ret -= frag->len;
+		count += frag->len;
+	} while (ret > 0);
+
+	SYS_LOG_DBG("Recv pkt %p len %d", pkt, net_pkt_get_len(pkt));
+
+	if (net_recv_data(ctx->iface, pkt) < 0) {
+		net_pkt_unref(pkt);
+	}
+
+	return 0;
+}
+
+static void eth_rx(struct eth_context *ctx)
+{
+	int ret;
+
+	SYS_LOG_DBG("Starting ZETH RX thread");
+
+	while (1) {
+		if (net_if_is_up(ctx->iface)) {
+			ret = eth_wait_data(ctx->dev_fd);
+			if (!ret) {
+				read_data(ctx, ctx->dev_fd);
+			}
+		}
+
+		k_sleep(MSEC(50));
+	}
+}
+
+static void create_rx_handler(struct eth_context *ctx)
+{
+	k_thread_create(&rx_thread_data, eth_rx_stack,
+			K_THREAD_STACK_SIZEOF(eth_rx_stack),
+			(k_thread_entry_t)eth_rx,
+			ctx, NULL, NULL, K_PRIO_COOP(14),
+			0, K_NO_WAIT);
+}
+
+static void eth_iface_init(struct net_if *iface)
+{
+	struct eth_context *ctx = net_if_get_device(iface)->driver_data;
+	struct net_linkaddr *ll_addr = eth_get_mac(ctx);
+
+	if (ctx->init_done) {
+		return;
+	}
+
+	ctx->init_done = true;
+	ctx->iface = iface;
+
+#if defined(CONFIG_ETH_NATIVE_POSIX_RANDOM_MAC)
+	/* 00-00-5E-00-53-xx Documentation RFC 7042 */
+	ctx->mac_addr[0] = 0x00;
+	ctx->mac_addr[1] = 0x00;
+	ctx->mac_addr[2] = 0x5E;
+	ctx->mac_addr[3] = 0x00;
+	ctx->mac_addr[4] = 0x53;
+	ctx->mac_addr[5] = sys_rand32_get();
+
+	/* The TUN/TAP setup script will by default set the MAC address of host
+	 * interface to 00:00:5E:00:53:FF so do not allow that.
+	 */
+	if (ctx->mac_addr[5] == 0xff) {
+		ctx->mac_addr[5] = 0x01;
+	}
+#else
+	if (CONFIG_ETH_NATIVE_POSIX_MAC_ADDR[0] != 0) {
+		if (net_bytes_from_str(ctx->mac_addr, sizeof(ctx->mac_addr),
+				       CONFIG_ETH_NATIVE_POSIX_MAC_ADDR) < 0) {
+			SYS_LOG_ERR("Invalid MAC address %s",
+				    CONFIG_ETH_NATIVE_POSIX_MAC_ADDR);
+		}
+	}
+#endif
+
+	net_if_set_link_addr(iface, ll_addr->addr, ll_addr->len,
+			     NET_LINK_ETHERNET);
+
+	ctx->if_name = CONFIG_ETH_NATIVE_POSIX_DRV_NAME;
+
+	ctx->dev_fd = eth_iface_create(ctx->if_name, false);
+	if (ctx->dev_fd < 0) {
+		SYS_LOG_ERR("Cannot create %s (%d)", ctx->if_name,
+			    ctx->dev_fd);
+	} else {
+		/* Create a thread that will handle incoming data from host */
+		create_rx_handler(ctx);
+
+		eth_setup_host(ctx->if_name);
+	}
+}
+
+static struct net_if_api eth_if_api = {
+	.init = eth_iface_init,
+	.send = eth_send,
+};
+
+NET_DEVICE_INIT(eth_native_posix, CONFIG_ETH_NATIVE_POSIX_DRV_NAME,
+		eth_init, &eth_context_data, NULL,
+		CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &eth_if_api,
+		_ETH_L2_LAYER, _ETH_L2_CTX_TYPE, _ETH_MTU);

drivers/ethernet/eth_native_posix_adapt.c

@@ -0,0 +1,140 @@
+/*
+ * Copyright (c) 2018 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/**
+ * @file
+ *
+ * Routines setting up the host system. Those are placed in separate file
+ * because there is naming conflicts between host and zephyr network stacks.
+ */
+
+#define _DEFAULT_SOURCE
+
+/* Host include files */
+#include <stdio.h>
+#include <stdarg.h>
+#include <errno.h>
+#include <string.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <net/if.h>
+
+#ifdef __linux
+#include <linux/if_tun.h>
+#endif
+
+/* Zephyr include files. Be very careful here and only include minimum
+ * things needed.
+ */
+#define SYS_LOG_DOMAIN "eth-posix-adapt"
+#define SYS_LOG_LEVEL CONFIG_SYS_LOG_ETHERNET_LEVEL
+
+#include <zephyr/types.h>
+#include <sys_clock.h>
+#include <logging/sys_log.h>
+
+#include "eth_native_posix_priv.h"
+
+/* Note that we cannot create the TUN/TAP device from the setup script
+ * as we need to get a file descriptor to communicate with the interface.
+ */
+int eth_iface_create(const char *if_name, bool tun_only)
+{
+	struct ifreq ifr;
+	int fd, ret = -EINVAL;
+
+	fd = open(CONFIG_ETH_NATIVE_POSIX_DEV_NAME, O_RDWR);
+	if (fd < 0) {
+		return -errno;
+	}
+
+	memset(&ifr, 0, sizeof(ifr));
+
+#ifdef __linux
+	ifr.ifr_flags = (tun_only ? IFF_TUN : IFF_TAP) | IFF_NO_PI;
+
+	strncpy(ifr.ifr_name, if_name, IFNAMSIZ);
+
+	ret = ioctl(fd, TUNSETIFF, (void *)&ifr);
+	if (ret < 0) {
+		ret = -errno;
+		close(fd);
+		return ret;
+	}
+#endif
+
+	return fd;
+}
+
+int eth_iface_remove(int fd)
+{
+	return close(fd);
+}
+
+static int ssystem(const char *fmt, ...)
+	__attribute__((__format__(__printf__, 1, 2)));
+
+static int ssystem(const char *fmt, ...)
+{
+	char cmd[255];
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsnprintf(cmd, sizeof(cmd), fmt, ap);
+	va_end(ap);
+
+	printk("%s\n", cmd);
+	fflush(stdout);
+
+	return system(cmd);
+}
+
+int eth_setup_host(const char *if_name)
+{
+	/* User might have added -i option to setup script string, so
+	 * check that situation in the script itself so that the -i option
+	 * we add here is ignored in that case.
+	 */
+	return ssystem("%s -i %s", CONFIG_ETH_NATIVE_POSIX_SETUP_SCRIPT,
+		       if_name);
+}
+
+int eth_wait_data(int fd)
+{
+	struct timeval timeout;
+	fd_set rset;
+	int ret;
+
+	FD_ZERO(&rset);
+
+	FD_SET(fd, &rset);
+
+	timeout.tv_sec = 0;
+	timeout.tv_usec = USEC(50);
+
+	ret = select(fd + 1, &rset, NULL, NULL, &timeout);
+	if (ret < 0 && errno != EINTR) {
+		return -errno;
+	} else if (ret > 0) {
+		if (FD_ISSET(fd, &rset)) {
+			return 0;
+		}
+	}
+
+	return -EAGAIN;
+}
+
+ssize_t eth_read_data(int fd, void *buf, size_t buf_len)
+{
+	return read(fd, buf, buf_len);
+}
+
+ssize_t eth_write_data(int fd, void *buf, size_t buf_len)
+{
+	return write(fd, buf, buf_len);
+}

drivers/ethernet/eth_native_posix_priv.h

@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2018 Intel Corporation
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+/** @file
+ * @brief Private functions for native posix ethernet driver.
+ */
+
+#ifndef _ETH_NATIVE_POSIX_PRIV_H
+#define _ETH_NATIVE_POSIX_PRIV_H
+
+int eth_iface_create(const char *if_name, bool tun_only);
+int eth_iface_remove(int fd);
+int eth_setup_host(const char *if_name);
+int eth_wait_data(int fd);
+ssize_t eth_read_data(int fd, void *buf, size_t buf_len);
+ssize_t eth_write_data(int fd, void *buf, size_t buf_len);
+
+#endif /* _ETH_NATIVE_POSIX_PRIV_H */