[ipxe-devel] [PATCH ipxe v1 4/4] [af_packet] new AF_PACKET driver for Linux

David Decotigny ddecotig at gmail.com
Mon Nov 14 07:11:50 GMT 2016


Just realized that this doesn't compile for i386, which uses
socketcall. Please ignore this version, I will send an update later.

On Fri, Nov 11, 2016 at 12:23 PM, David Decotigny <ddecotig at gmail.com> wrote:
> This code largely inspired from tap.c.
>
> Allows to test ipxe on real NICs from Linux. Example:
>   make -j -C src bin-x86_64-linux/af_packet.linux
>   valgrind ./af_packet.linux --net af_packet,if=eth3 --settings uuid=$(uuidgen)
>
>
> ---
>  src/arch/x86/core/linux/linux_api.c |  14 ++
>  src/drivers/linux/af_packet.c       | 325 ++++++++++++++++++++++++++++++++++++
>  src/include/ipxe/errfile.h          |   1 +
>  src/include/linux_api.h             |   7 +
>  4 files changed, 347 insertions(+)
>  create mode 100644 src/drivers/linux/af_packet.c
>
> diff --git a/src/arch/x86/core/linux/linux_api.c b/src/arch/x86/core/linux/linux_api.c
> index 0bed9fd..dd57be7 100644
> --- a/src/arch/x86/core/linux/linux_api.c
> +++ b/src/arch/x86/core/linux/linux_api.c
> @@ -108,3 +108,17 @@ void * linux_mremap ( void *old_address, __kernel_size_t old_size,
>  int linux_munmap ( void *addr, __kernel_size_t length ) {
>         return linux_syscall ( __NR_munmap, addr, length );
>  }
> +
> +int linux_socket ( int domain, int type_, int protocol ) {
> +       return linux_syscall ( __NR_socket, domain, type_, protocol );
> +}
> +
> +int linux_bind ( int fd, const struct sockaddr *addr, socklen_t addrlen ) {
> +       return linux_syscall ( __NR_bind, fd, addr, addrlen );
> +}
> +
> +ssize_t linux_sendto ( int fd, const void *buf, size_t len, int flags,
> +                      const struct sockaddr *daddr, socklen_t addrlen ) {
> +       return linux_syscall ( __NR_sendto, fd, buf, len, flags,
> +                              daddr, addrlen );
> +}
> diff --git a/src/drivers/linux/af_packet.c b/src/drivers/linux/af_packet.c
> new file mode 100644
> index 0000000..1622c8c
> --- /dev/null
> +++ b/src/drivers/linux/af_packet.c
> @@ -0,0 +1,325 @@
> +/*
> + * Copyright (C) 2016 David Decotigny <ddecotig at 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 __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,
> +};
> diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
> index 08e166c..67de123 100644
> --- a/src/include/ipxe/errfile.h
> +++ b/src/include/ipxe/errfile.h
> @@ -193,6 +193,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
>  #define ERRFILE_pciea               ( ERRFILE_DRIVER | 0x00c00000 )
>  #define ERRFILE_axge                ( ERRFILE_DRIVER | 0x00c10000 )
>  #define ERRFILE_thunderx            ( ERRFILE_DRIVER | 0x00c20000 )
> +#define ERRFILE_af_packet           ( ERRFILE_DRIVER | 0x00c30000 )
>
>  #define ERRFILE_aoe                    ( ERRFILE_NET | 0x00000000 )
>  #define ERRFILE_arp                    ( ERRFILE_NET | 0x00010000 )
> diff --git a/src/include/linux_api.h b/src/include/linux_api.h
> index 28a3cda..fe9fa91 100644
> --- a/src/include/linux_api.h
> +++ b/src/include/linux_api.h
> @@ -46,6 +46,8 @@ typedef __kernel_loff_t loff_t;
>  #include <linux/poll.h>
>  typedef unsigned long nfds_t;
>  typedef uint32_t useconds_t;
> +typedef uint32_t socklen_t;
> +struct sockaddr;
>  #define MAP_FAILED ( ( void * ) -1 )
>  #define SEEK_SET 0
>
> @@ -68,6 +70,11 @@ extern void * linux_mmap ( void *addr, __kernel_size_t length, int prot,
>  extern void * linux_mremap ( void *old_address, __kernel_size_t old_size,
>                              __kernel_size_t new_size, int flags );
>  extern int linux_munmap ( void *addr, __kernel_size_t length );
> +extern int linux_socket ( int domain, int type_, int protocol );
> +extern int linux_bind ( int fd, const struct sockaddr *addr,
> +                       socklen_t addrlen );
> +extern ssize_t linux_sendto ( int fd, const void *buf, size_t len, int flags,
> +                             const struct sockaddr *daddr, socklen_t addrlen );
>
>  extern const char * linux_strerror ( int errnum );
>
> --
> 2.8.0.rc3.226.g39d4020
>


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