src/drivers/linux/af_packet.c - ipxe - Git at Google

 /*
  * Copyright (C) 2016 David Decotigny <ddecotig@gmail.com>
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License as
  * published by the Free Software Foundation; either version 2 of the
  * License, or any later version.
  *
  * This program is distributed in the hope that it will be useful, but
  * WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  */

 #include <errno.h>
 #include <string.h>
 #include <stdio.h>
 #include <linux_api.h>
 #include <ipxe/list.h>
 #include <ipxe/linux.h>
 #include <ipxe/malloc.h>
 #include <ipxe/device.h>
 #include <ipxe/netdevice.h>
 #include <ipxe/iobuf.h>
 #include <ipxe/ethernet.h>
 #include <ipxe/settings.h>
 #include <ipxe/socket.h>

 /* This hack prevents pre-2.6.32 headers from redefining struct sockaddr */
 #define _SYS_SOCKET_H
 #define __GLIBC__ 2
 #include <linux/socket.h>
 #include <linux/if.h>
 #include <linux/if_ether.h>
 #include <linux/if_packet.h>
 #undef __GLIBC__
 #include <byteswap.h>

 /* linux-specifc syscall params */
 #define LINUX_AF_PACKET 17
 #define LINUX_SOCK_RAW 3
 #define LINUX_SIOCGIFINDEX 0x8933
 #define LINUX_SIOCGIFHWADDR 0x8927

 #define RX_BUF_SIZE 1536

 /** @file
  *
  * The AF_PACKET driver.
  *
  * Bind to an existing linux network interface.
  */

 struct af_packet_nic {
 	/** Linux network interface name */
 	char * ifname;
 	/** Packet socket descriptor */
 	int fd;
 	/** ifindex */
 	int ifindex;
 };

 /** Open the linux interface */
 static int af_packet_nic_open ( struct net_device * netdev )
 {
 	struct af_packet_nic * nic = netdev->priv;
 	struct sockaddr_ll socket_address;
 	struct ifreq if_data;
 	int ret;

 	nic->fd = linux_socket(LINUX_AF_PACKET, LINUX_SOCK_RAW,
 			       htons(ETH_P_ALL));
 	if (nic->fd < 0) {
 		DBGC(nic, "af_packet %p socket(AF_PACKET) = %d (%s)\n",
 		     nic, nic->fd, linux_strerror(linux_errno));
 		return nic->fd;
 	}

 	/* resolve ifindex of ifname */
 	memset(&if_data, 0, sizeof(if_data));
 	strncpy(if_data.ifr_name, nic->ifname, sizeof(if_data.ifr_name));
 	ret = linux_ioctl(nic->fd, LINUX_SIOCGIFINDEX, &if_data);
 	if (ret < 0) {
 		DBGC(nic, "af_packet %p ioctl(SIOCGIFINDEX) = %d (%s)\n",
 		     nic, ret, linux_strerror(linux_errno));
 		linux_close(nic->fd);
 		return ret;
 	}

 	nic->ifindex = if_data.ifr_ifindex;

 	/* bind to interface */
 	memset(&socket_address, 0, sizeof(socket_address));
 	socket_address.sll_family = LINUX_AF_PACKET;
 	socket_address.sll_ifindex = nic->ifindex;
 	socket_address.sll_protocol = htons(ETH_P_ALL);
 	ret = linux_bind(nic->fd, (void *) &socket_address,
 			 sizeof(socket_address));
 	if (ret == -1) {
 		DBGC(nic, "af_packet %p bind() = %d (%s)\n",
 		     nic, ret, linux_strerror(linux_errno));
 		linux_close(nic->fd);
 		return ret;
 	}

 	/* Set nonblocking mode to make af_packet_nic_poll() easier */
 	ret = linux_fcntl(nic->fd, F_SETFL, O_NONBLOCK);
 	if (ret != 0) {
 		DBGC(nic, "af_packet %p fcntl(%d, ...) = %d (%s)\n",
 		     nic, nic->fd, ret, linux_strerror(linux_errno));
 		linux_close(nic->fd);
 		return ret;
 	}

 	return 0;
 }

 /** Close the packet socket */
 static void af_packet_nic_close ( struct net_device *netdev )
 {
 	struct af_packet_nic * nic = netdev->priv;
 	linux_close(nic->fd);
 }

 /**
  * Transmit an ethernet packet.
  *
  * The packet can be written to the socket and marked as complete immediately.
  */
 static int af_packet_nic_transmit ( struct net_device *netdev,
 				    struct io_buffer *iobuf )
 {
 	struct af_packet_nic * nic = netdev->priv;
 	struct sockaddr_ll socket_address;
 	const struct ethhdr * eh;
 	int rc;

 	memset(&socket_address, 0, sizeof(socket_address));
 	socket_address.sll_family = LINUX_AF_PACKET;
 	socket_address.sll_ifindex = nic->ifindex;
 	socket_address.sll_halen = ETH_ALEN;

 	eh = iobuf->data;
 	memcpy(socket_address.sll_addr, eh->h_dest, ETH_ALEN);

 	rc = linux_sendto(nic->fd, iobuf->data, iobuf->tail - iobuf->data,
 			  0, (struct sockaddr *)&socket_address,
 			  sizeof(socket_address));

 	DBGC2(nic, "af_packet %p wrote %d bytes\n", nic, rc);
 	netdev_tx_complete(netdev, iobuf);

 	return 0;
 }

 /** Poll for new packets */
 static void af_packet_nic_poll ( struct net_device *netdev )
 {
 	struct af_packet_nic * nic = netdev->priv;
 	struct pollfd pfd;
 	struct io_buffer * iobuf;
 	int r;

 	pfd.fd = nic->fd;
 	pfd.events = POLLIN;
 	if (linux_poll(&pfd, 1, 0) == -1) {
 		DBGC(nic, "af_packet %p poll failed (%s)\n",
 		     nic, linux_strerror(linux_errno));
 		return;
 	}
 	if ((pfd.revents & POLLIN) == 0)
 		return;

 	/* At this point we know there is at least one new packet to be read */

 	iobuf = alloc_iob(RX_BUF_SIZE);
 	if (! iobuf)
 		goto allocfail;

 	while ((r = linux_read(nic->fd, iobuf->data, RX_BUF_SIZE)) > 0) {
 		DBGC2(nic, "af_packet %p read %d bytes\n", nic, r);

 		iob_put(iobuf, r);
 		netdev_rx(netdev, iobuf);

 		iobuf = alloc_iob(RX_BUF_SIZE);
 		if (! iobuf)
 			goto allocfail;
 	}

 	free_iob(iobuf);
 	return;

 allocfail:
 	DBGC(nic, "af_packet %p alloc_iob failed\n", nic);
 }

 /**
  * Set irq.
  *
  * Not used on linux, provide a dummy implementation.
  */
 static void af_packet_nic_irq ( struct net_device *netdev, int enable )
 {
 	struct af_packet_nic *nic = netdev->priv;

 	DBGC(nic, "af_packet %p irq enable = %d\n", nic, enable);
 }


 static int af_packet_update_properties ( struct net_device *netdev )
 {
 	struct af_packet_nic *nic = netdev->priv;
 	struct ifreq if_data;
 	int ret;

 	/* retrieve default MAC address */
 	int fd = linux_socket(LINUX_AF_PACKET, LINUX_SOCK_RAW, 0);
 	if (fd < 0) {
 		DBGC(nic, "af_packet %p cannot create raw socket (%s)\n",
 		     nic, linux_strerror(linux_errno));
 		return fd;
 	}

 	/* retrieve host's MAC address */
 	memset(&if_data, 0, sizeof(if_data));
 	strncpy(if_data.ifr_name, nic->ifname, sizeof(if_data.ifr_name));
 	ret = linux_ioctl(fd, LINUX_SIOCGIFHWADDR, &if_data);
 	if (ret < 0) {
 		DBGC(nic, "af_packet %p cannot get mac addr (%s)\n",
 		     nic, linux_strerror(linux_errno));
 		linux_close(fd);
 		return ret;
 	}

 	linux_close(fd);
 	/* struct sockaddr = { u16 family, u8 pad[14] (equiv. sa_data) }; */
 	memcpy(netdev->ll_addr, if_data.ifr_hwaddr.pad, ETH_ALEN);
 	return 0;
 }

 /** AF_PACKET operations */
 static struct net_device_operations af_packet_nic_operations = {
 	.open		= af_packet_nic_open,
 	.close		= af_packet_nic_close,
 	.transmit	= af_packet_nic_transmit,
 	.poll		= af_packet_nic_poll,
 	.irq		= af_packet_nic_irq,
 };

 /** Handle a device request for the af_packet driver */
 static int af_packet_nic_probe ( struct linux_device *device,
 				 struct linux_device_request *request )
 {
 	struct linux_setting *if_setting;
 	struct net_device *netdev;
 	struct af_packet_nic *nic;
 	int rc;

 	netdev = alloc_etherdev(sizeof(*nic));
 	if (! netdev)
 		return -ENOMEM;

 	netdev_init(netdev, &af_packet_nic_operations);
 	nic = netdev->priv;
 	linux_set_drvdata(device, netdev);
 	netdev->dev = &device->dev;

 	memset(nic, 0, sizeof(*nic));

 	/* Look for the mandatory if setting */
 	if_setting = linux_find_setting("if", &request->settings);

 	/* No if setting */
 	if (! if_setting) {
 		printf("af_packet missing a mandatory if setting\n");
 		rc = -EINVAL;
 		goto err_settings;
 	}

 	nic->ifname = if_setting->value;
 	snprintf ( device->dev.name, sizeof ( device->dev.name ), "%s",
 		   nic->ifname );
 	device->dev.desc.bus_type = BUS_TYPE_TAP;
 	af_packet_update_properties(netdev);
 	if_setting->applied = 1;

 	/* Apply rest of the settings */
 	linux_apply_settings(&request->settings, &netdev->settings.settings);

 	/* Register network device */
 	if ((rc = register_netdev(netdev)) != 0)
 		goto err_register;

 	netdev_link_up(netdev);

 	return 0;

 err_settings:
 	unregister_netdev(netdev);
 err_register:
 	netdev_nullify(netdev);
 	netdev_put(netdev);
 	return rc;
 }

 /** Remove the device */
 static void af_packet_nic_remove ( struct linux_device *device )
 {
 	struct net_device *netdev = linux_get_drvdata(device);
 	unregister_netdev(netdev);
 	netdev_nullify(netdev);
 	netdev_put(netdev);
 }

 /** AF_PACKET linux_driver */
 struct linux_driver af_packet_nic_driver __linux_driver = {
 	.name = "af_packet",
 	.probe = af_packet_nic_probe,
 	.remove = af_packet_nic_remove,
 	.can_probe = 1,
 };
	/*
	* Copyright (C) 2016 David Decotigny <ddecotig@gmail.com>
	*
	* This program is free software; you can redistribute it and/or
	* modify it under the terms of the GNU General Public License as
	* published by the Free Software Foundation; either version 2 of the
	* License, or any later version.
	*
	* This program is distributed in the hope that it will be useful, but
	* WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*/

	#include <errno.h>
	#include <string.h>
	#include <stdio.h>
	#include <linux_api.h>
	#include <ipxe/list.h>
	#include <ipxe/linux.h>
	#include <ipxe/malloc.h>
	#include <ipxe/device.h>
	#include <ipxe/netdevice.h>
	#include <ipxe/iobuf.h>
	#include <ipxe/ethernet.h>
	#include <ipxe/settings.h>
	#include <ipxe/socket.h>

	/* This hack prevents pre-2.6.32 headers from redefining struct sockaddr */
	#define _SYS_SOCKET_H
	#define __GLIBC__ 2
	#include <linux/socket.h>
	#include <linux/if.h>
	#include <linux/if_ether.h>
	#include <linux/if_packet.h>
	#undef __GLIBC__
	#include <byteswap.h>

	/* linux-specifc syscall params */
	#define LINUX_AF_PACKET 17
	#define LINUX_SOCK_RAW 3
	#define LINUX_SIOCGIFINDEX 0x8933
	#define LINUX_SIOCGIFHWADDR 0x8927

	#define RX_BUF_SIZE 1536

	/** @file
	*
	* The AF_PACKET driver.
	*
	* Bind to an existing linux network interface.
	*/

	struct af_packet_nic {
	/** Linux network interface name */
	char * ifname;
	/** Packet socket descriptor */
	int fd;
	/** ifindex */
	int ifindex;
	};

	/** Open the linux interface */
	static int af_packet_nic_open ( struct net_device * netdev )
	{
	struct af_packet_nic * nic = netdev->priv;
	struct sockaddr_ll socket_address;
	struct ifreq if_data;
	int ret;

	nic->fd = linux_socket(LINUX_AF_PACKET, LINUX_SOCK_RAW,
	htons(ETH_P_ALL));
	if (nic->fd < 0) {
	DBGC(nic, "af_packet %p socket(AF_PACKET) = %d (%s)\n",
	nic, nic->fd, linux_strerror(linux_errno));
	return nic->fd;
	}

	/* resolve ifindex of ifname */
	memset(&if_data, 0, sizeof(if_data));
	strncpy(if_data.ifr_name, nic->ifname, sizeof(if_data.ifr_name));
	ret = linux_ioctl(nic->fd, LINUX_SIOCGIFINDEX, &if_data);
	if (ret < 0) {
	DBGC(nic, "af_packet %p ioctl(SIOCGIFINDEX) = %d (%s)\n",
	nic, ret, linux_strerror(linux_errno));
	linux_close(nic->fd);
	return ret;
	}

	nic->ifindex = if_data.ifr_ifindex;

	/* bind to interface */
	memset(&socket_address, 0, sizeof(socket_address));
	socket_address.sll_family = LINUX_AF_PACKET;
	socket_address.sll_ifindex = nic->ifindex;
	socket_address.sll_protocol = htons(ETH_P_ALL);
	ret = linux_bind(nic->fd, (void *) &socket_address,
	sizeof(socket_address));
	if (ret == -1) {
	DBGC(nic, "af_packet %p bind() = %d (%s)\n",
	nic, ret, linux_strerror(linux_errno));
	linux_close(nic->fd);
	return ret;
	}

	/* Set nonblocking mode to make af_packet_nic_poll() easier */
	ret = linux_fcntl(nic->fd, F_SETFL, O_NONBLOCK);
	if (ret != 0) {
	DBGC(nic, "af_packet %p fcntl(%d, ...) = %d (%s)\n",
	nic, nic->fd, ret, linux_strerror(linux_errno));
	linux_close(nic->fd);
	return ret;
	}

	return 0;
	}

	/** Close the packet socket */
	static void af_packet_nic_close ( struct net_device *netdev )
	{
	struct af_packet_nic * nic = netdev->priv;
	linux_close(nic->fd);
	}

	/**
	* Transmit an ethernet packet.
	*
	* The packet can be written to the socket and marked as complete immediately.
	*/
	static int af_packet_nic_transmit ( struct net_device *netdev,
	struct io_buffer *iobuf )
	{
	struct af_packet_nic * nic = netdev->priv;
	struct sockaddr_ll socket_address;
	const struct ethhdr * eh;
	int rc;

	memset(&socket_address, 0, sizeof(socket_address));
	socket_address.sll_family = LINUX_AF_PACKET;
	socket_address.sll_ifindex = nic->ifindex;
	socket_address.sll_halen = ETH_ALEN;

	eh = iobuf->data;
	memcpy(socket_address.sll_addr, eh->h_dest, ETH_ALEN);

	rc = linux_sendto(nic->fd, iobuf->data, iobuf->tail - iobuf->data,
	0, (struct sockaddr *)&socket_address,
	sizeof(socket_address));

	DBGC2(nic, "af_packet %p wrote %d bytes\n", nic, rc);
	netdev_tx_complete(netdev, iobuf);

	return 0;
	}

	/** Poll for new packets */
	static void af_packet_nic_poll ( struct net_device *netdev )
	{
	struct af_packet_nic * nic = netdev->priv;
	struct pollfd pfd;
	struct io_buffer * iobuf;
	int r;

	pfd.fd = nic->fd;
	pfd.events = POLLIN;
	if (linux_poll(&pfd, 1, 0) == -1) {
	DBGC(nic, "af_packet %p poll failed (%s)\n",
	nic, linux_strerror(linux_errno));
	return;
	}
	if ((pfd.revents & POLLIN) == 0)
	return;

	/* At this point we know there is at least one new packet to be read */

	iobuf = alloc_iob(RX_BUF_SIZE);
	if (! iobuf)
	goto allocfail;

	while ((r = linux_read(nic->fd, iobuf->data, RX_BUF_SIZE)) > 0) {
	DBGC2(nic, "af_packet %p read %d bytes\n", nic, r);

	iob_put(iobuf, r);
	netdev_rx(netdev, iobuf);

	iobuf = alloc_iob(RX_BUF_SIZE);
	if (! iobuf)
	goto allocfail;
	}

	free_iob(iobuf);
	return;

	allocfail:
	DBGC(nic, "af_packet %p alloc_iob failed\n", nic);
	}

	/**
	* Set irq.
	*
	* Not used on linux, provide a dummy implementation.
	*/
	static void af_packet_nic_irq ( struct net_device *netdev, int enable )
	{
	struct af_packet_nic *nic = netdev->priv;

	DBGC(nic, "af_packet %p irq enable = %d\n", nic, enable);
	}


	static int af_packet_update_properties ( struct net_device *netdev )
	{
	struct af_packet_nic *nic = netdev->priv;
	struct ifreq if_data;
	int ret;

	/* retrieve default MAC address */
	int fd = linux_socket(LINUX_AF_PACKET, LINUX_SOCK_RAW, 0);
	if (fd < 0) {
	DBGC(nic, "af_packet %p cannot create raw socket (%s)\n",
	nic, linux_strerror(linux_errno));
	return fd;
	}

	/* retrieve host's MAC address */
	memset(&if_data, 0, sizeof(if_data));
	strncpy(if_data.ifr_name, nic->ifname, sizeof(if_data.ifr_name));
	ret = linux_ioctl(fd, LINUX_SIOCGIFHWADDR, &if_data);
	if (ret < 0) {
	DBGC(nic, "af_packet %p cannot get mac addr (%s)\n",
	nic, linux_strerror(linux_errno));
	linux_close(fd);
	return ret;
	}

	linux_close(fd);
	/* struct sockaddr = { u16 family, u8 pad[14] (equiv. sa_data) }; */
	memcpy(netdev->ll_addr, if_data.ifr_hwaddr.pad, ETH_ALEN);
	return 0;
	}

	/** AF_PACKET operations */
	static struct net_device_operations af_packet_nic_operations = {
	.open = af_packet_nic_open,
	.close = af_packet_nic_close,
	.transmit = af_packet_nic_transmit,
	.poll = af_packet_nic_poll,
	.irq = af_packet_nic_irq,
	};

	/** Handle a device request for the af_packet driver */
	static int af_packet_nic_probe ( struct linux_device *device,
	struct linux_device_request *request )
	{
	struct linux_setting *if_setting;
	struct net_device *netdev;
	struct af_packet_nic *nic;
	int rc;

	netdev = alloc_etherdev(sizeof(*nic));
	if (! netdev)
	return -ENOMEM;

	netdev_init(netdev, &af_packet_nic_operations);
	nic = netdev->priv;
	linux_set_drvdata(device, netdev);
	netdev->dev = &device->dev;

	memset(nic, 0, sizeof(*nic));

	/* Look for the mandatory if setting */
	if_setting = linux_find_setting("if", &request->settings);

	/* No if setting */
	if (! if_setting) {
	printf("af_packet missing a mandatory if setting\n");
	rc = -EINVAL;
	goto err_settings;
	}

	nic->ifname = if_setting->value;
	snprintf ( device->dev.name, sizeof ( device->dev.name ), "%s",
	nic->ifname );
	device->dev.desc.bus_type = BUS_TYPE_TAP;
	af_packet_update_properties(netdev);
	if_setting->applied = 1;

	/* Apply rest of the settings */
	linux_apply_settings(&request->settings, &netdev->settings.settings);

	/* Register network device */
	if ((rc = register_netdev(netdev)) != 0)
	goto err_register;

	netdev_link_up(netdev);

	return 0;

	err_settings:
	unregister_netdev(netdev);
	err_register:
	netdev_nullify(netdev);
	netdev_put(netdev);
	return rc;
	}

	/** Remove the device */
	static void af_packet_nic_remove ( struct linux_device *device )
	{
	struct net_device *netdev = linux_get_drvdata(device);
	unregister_netdev(netdev);
	netdev_nullify(netdev);
	netdev_put(netdev);
	}

	/** AF_PACKET linux_driver */
	struct linux_driver af_packet_nic_driver __linux_driver = {
	.name = "af_packet",
	.probe = af_packet_nic_probe,
	.remove = af_packet_nic_remove,
	.can_probe = 1,
	};