af_packet.c File Reference

The AF_PACKET driver. More...

#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <ipxe/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>
#include <linux/socket.h>
#include <linux/if.h>
#include <linux/if_ether.h>
#include <linux/if_packet.h>
#include <byteswap.h>

Go to the source code of this file.

Data Structures
struct	af_packet_nic

Macros
#define	_SYS_SOCKET_H
#define	__GLIBC__   2
#define	LINUX_AF_PACKET   17
#define	LINUX_SOCK_RAW   3
#define	LINUX_SIOCGIFINDEX   0x8933
#define	LINUX_SIOCGIFHWADDR   0x8927
#define	RX_BUF_SIZE   1536

Functions
static int	af_packet_nic_open (struct net_device *netdev)
	Open the linux interface.
static void	af_packet_nic_close (struct net_device *netdev)
	Close the packet socket.
static int	af_packet_nic_transmit (struct net_device *netdev, struct io_buffer *iobuf)
	Transmit an ethernet packet.
static void	af_packet_nic_poll (struct net_device *netdev)
	Poll for new packets.
static void	af_packet_nic_irq (struct net_device *netdev, int enable)
	Set irq.
static int	af_packet_update_properties (struct net_device *netdev)
static int	af_packet_nic_probe (struct linux_device *device, struct linux_device_request *request)
	Handle a device request for the af_packet driver.
static void	af_packet_nic_remove (struct linux_device *device)
	Remove the device.
	LINUX_ROM ("af_packet", "AF_PACKET binding NIC")

Variables
static struct net_device_operations	af_packet_nic_operations
	AF_PACKET operations.
struct linux_driver af_packet_nic_driver	__linux_driver
	AF_PACKET linux_driver.

Detailed Description

The AF_PACKET driver.

Bind to an existing linux network interface.

Definition in file af_packet.c.

Macro Definition Documentation

_SYS_SOCKET_H

#define _SYS_SOCKET_H

Definition at line 34 of file af_packet.c.

__GLIBC__

#define __GLIBC__   2

Definition at line 35 of file af_packet.c.

LINUX_AF_PACKET

#define LINUX_AF_PACKET   17

Definition at line 44 of file af_packet.c.

Referenced by af_packet_nic_open(), af_packet_nic_transmit(), and af_packet_update_properties().

LINUX_SOCK_RAW

#define LINUX_SOCK_RAW   3

Definition at line 45 of file af_packet.c.

Referenced by af_packet_nic_open(), and af_packet_update_properties().

LINUX_SIOCGIFINDEX

#define LINUX_SIOCGIFINDEX   0x8933

Definition at line 46 of file af_packet.c.

Referenced by af_packet_nic_open().

LINUX_SIOCGIFHWADDR

#define LINUX_SIOCGIFHWADDR   0x8927

Definition at line 47 of file af_packet.c.

Referenced by af_packet_update_properties().

RX_BUF_SIZE

#define RX_BUF_SIZE   1536

Definition at line 49 of file af_packet.c.

Function Documentation

af_packet_nic_open()

int af_packet_nic_open ( struct net_device * netdev )

static

Open the linux interface.

Definition at line 68 of file af_packet.c.

{
        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;
}

References DBGC, htons, LINUX_AF_PACKET, linux_bind(), linux_close(), linux_errno, linux_fcntl(), linux_ioctl(), LINUX_SIOCGIFINDEX, LINUX_SOCK_RAW, linux_socket(), linux_strerror(), memset(), netdev, and strncpy().

af_packet_nic_close()

void af_packet_nic_close ( struct net_device * netdev )

static

Close the packet socket.

Definition at line 123 of file af_packet.c.

{
        struct af_packet_nic * nic = netdev->priv;
        linux_close(nic->fd);
}

References linux_close(), and netdev.

af_packet_nic_transmit()

int af_packet_nic_transmit ( struct net_device * netdev, struct io_buffer * iobuf )

static

Transmit an ethernet packet.

The packet can be written to the socket and marked as complete immediately.

Definition at line 134 of file af_packet.c.

{
        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;
}

References io_buffer::data, DBGC2, ETH_ALEN, ethhdr::h_dest, LINUX_AF_PACKET, linux_sendto(), memcpy(), memset(), netdev, netdev_tx_complete(), rc, and io_buffer::tail.

af_packet_nic_poll()

void af_packet_nic_poll ( struct net_device * netdev )

static

Poll for new packets.

Definition at line 161 of file af_packet.c.

{
        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);
}

References alloc_iob(), io_buffer::data, DBGC, DBGC2, free_iob(), iob_put, linux_errno, linux_poll(), linux_read(), linux_strerror(), netdev, netdev_rx(), r, and RX_BUF_SIZE.

af_packet_nic_irq()

void af_packet_nic_irq ( struct net_device * netdev, int enable )

static

Set irq.

Not used on linux, provide a dummy implementation.

Definition at line 207 of file af_packet.c.

{
        struct af_packet_nic *nic = netdev->priv;
 
        DBGC(nic, "af_packet %p irq enable = %d\n", nic, enable);
}

References DBGC, and netdev.

af_packet_update_properties()

int af_packet_update_properties ( struct net_device * netdev )

static

Definition at line 215 of file af_packet.c.

{
        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;
}

References DBGC, ETH_ALEN, LINUX_AF_PACKET, linux_close(), linux_errno, linux_ioctl(), LINUX_SIOCGIFHWADDR, LINUX_SOCK_RAW, linux_socket(), linux_strerror(), memcpy(), memset(), netdev, and strncpy().

Referenced by af_packet_nic_probe().

af_packet_nic_probe()

int af_packet_nic_probe ( struct linux_device * device, struct linux_device_request * request )

static

Handle a device request for the af_packet driver.

Definition at line 256 of file af_packet.c.

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

References af_packet_nic_operations, af_packet_update_properties(), alloc_etherdev(), linux_setting::applied, device_description::bus_type, BUS_TYPE_TAP, device::desc, EINVAL, ENOMEM, linux_apply_settings(), linux_find_setting(), linux_set_drvdata(), memset(), device::name, netdev, netdev_init(), netdev_link_up(), netdev_nullify(), netdev_put(), printf(), rc, register_netdev(), request, snprintf(), unregister_netdev(), and linux_setting::value.

af_packet_nic_remove()

void af_packet_nic_remove ( struct linux_device * device )

static

Remove the device.

Definition at line 312 of file af_packet.c.

{
        struct net_device *netdev = linux_get_drvdata(device);
        unregister_netdev(netdev);
        netdev_nullify(netdev);
        netdev_put(netdev);
}

References linux_get_drvdata(), netdev, netdev_nullify(), netdev_put(), and unregister_netdev().

LINUX_ROM()

LINUX_ROM	(	"af_packet"	,
		"AF_PACKET binding NIC"	)

Variable Documentation

af_packet_nic_operations

struct net_device_operations af_packet_nic_operations

static

Initial value:

= {
        .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,
}

AF_PACKET operations.

Definition at line 247 of file af_packet.c.

                                                               {
        .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,
};

Referenced by af_packet_nic_probe().

__linux_driver

struct linux_driver af_packet_nic_driver __linux_driver

Initial value:

= {
        .name = "af_packet",
        .probe = af_packet_nic_probe,
        .remove = af_packet_nic_remove,
}

AF_PACKET linux_driver.

Definition at line 321 of file af_packet.c.

                                                          {
        .name = "af_packet",
        .probe = af_packet_nic_probe,
        .remove = af_packet_nic_remove,
};