[U-Boot] [PATCH] sandbox: Add tap based networking
Simon Glass
sjg at chromium.org
Wed Dec 14 00:54:59 CET 2011
Hi Matthias,
On Sun, Dec 4, 2011 at 9:57 AM, Matthias Weisser <weisserm at arcor.de> wrote:
> This patch adds support for networking to sandbox architecture using
> tap. A tap device "tap0" has to be created e.g. using openvpn
>
> $ openvpn --mktun --dev tap0
>
> u-boot should then be able to detect the network device on startup.
> To test the network related commands the following commands can be used
> to create an ethernet bridge to local network connection.
>
> $ brctl addbr br0
> $ ifconfig eth0 0.0.0.0 promisc
> $ ifconfig tap0 0.0.0.0
> $ brctl addif br0 eth0
> $ brctl addif br0 tap0
> $ ifconfig br0 up
> $ pump -i br0
>
> Signed-off-by: Matthias Weisser <weisserm at arcor.de>
Unfortunately I was unable to test this easily and then ran out of
time. But it looks good, with a few comments.
> ---
> This patch also needs these patches to work
> http://patchwork.ozlabs.org/patch/128279/
> http://patchwork.ozlabs.org/patch/129084/
>
> Changes from RFC:
> Multiple tap interfaces possible now
> Minor cleanups due to comments from Mike Frysinger
>
> arch/sandbox/cpu/cpu.c | 8 +++
> arch/sandbox/cpu/os.c | 101 ++++++++++++++++++++++++++++++++++++++
> arch/sandbox/lib/board.c | 5 ++
> drivers/net/Makefile | 1 +
> drivers/net/tap.c | 118 +++++++++++++++++++++++++++++++++++++++++++++
> include/configs/sandbox.h | 9 ++--
> include/netdev.h | 1 +
> include/os.h | 18 +++++++
> 8 files changed, 257 insertions(+), 4 deletions(-)
> create mode 100644 drivers/net/tap.c
>
> diff --git a/arch/sandbox/cpu/cpu.c b/arch/sandbox/cpu/cpu.c
> index d7684d3..2fb3bae 100644
> --- a/arch/sandbox/cpu/cpu.c
> +++ b/arch/sandbox/cpu/cpu.c
> @@ -21,6 +21,7 @@
>
> #include <common.h>
> #include <os.h>
> +#include <netdev.h>
>
> DECLARE_GLOBAL_DATA_PTR;
>
> @@ -60,3 +61,10 @@ void *map_physmem(phys_addr_t paddr, unsigned long len, unsigned long flags)
> void flush_dcache_range(unsigned long start, unsigned long stop)
> {
> }
> +
> +#ifdef CONFIG_NET_TAP
> +int cpu_eth_init(bd_t *bis)
> +{
> + return tap_initialize(bis, "tap0");
> +}
> +#endif
> diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
> index 6d55b5c..0c8cc82 100644
> --- a/arch/sandbox/cpu/os.c
> +++ b/arch/sandbox/cpu/os.c
> @@ -19,6 +19,7 @@
> * MA 02111-1307 USA
> */
>
> +#include <config.h>
> #include <fcntl.h>
> #include <stdlib.h>
> #include <termios.h>
> @@ -30,6 +31,19 @@
> #include <sys/mman.h>
> #include <linux/types.h>
>
> +#ifdef CONFIG_NET_TAP
I don't think we need this #ifdef
> +#include <string.h>
> +#include <stdio.h>
> +#include <sys/ioctl.h>
> +#include <sys/socket.h>
> +#include <linux/socket.h>
> +#include <linux/if.h>
> +#include <linux/if_tun.h>
> +#include <linux/if_arp.h>
> +#include <linux/if_ether.h>
> +
> +#endif
> +
> #include <os.h>
>
> /* Operating System Interface */
> @@ -121,3 +135,90 @@ u64 os_get_nsec(void)
> return tv.tv_sec * 1000000000ULL + tv.tv_usec * 1000;
> #endif
> }
> +
> +#ifdef CONFIG_NET_TAP
Is there a reason for not always enabling this function?
> +int os_tap_open(const char *dev, unsigned char *hwaddr)
> +{
> + struct ifreq ifr;
> + int fd, err;
> +
> + fd = open("/dev/net/tun", O_RDWR | O_NONBLOCK);
> + if (fd < 0) {
> + perror("could not open /dev/net/tun");
> + return -1;
> + }
> +
> + memset(&ifr, 0, sizeof(ifr));
> +
> + /* Flags: IFF_TUN - TUN device (no Ethernet headers)
Comment style:
/*
* Flags:
> + * IFF_TAP - TAP device
> + *
> + * IFF_NO_PI - Do not provide packet information
> + */
> + ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
> + strncpy(ifr.ifr_name, dev, IFNAMSIZ);
> +
> + err = ioctl(fd, TUNSETIFF, (void *)&ifr);
> + if (err < 0) {
> + perror("could not get tap device");
> + close(fd);
> + return err;
> + }
> +
> + if (ioctl(fd, SIOCGIFHWADDR, (void *)&ifr) >= 0)
> + memcpy(hwaddr, &ifr.ifr_hwaddr.sa_data, ETH_ALEN);
> +
> + return fd;
> +}
> +
> +int os_tap_set_hw_addr(int fd, unsigned char *hwaddr)
> +{
> + /*
> + * The following code should be able to change the MAC of a TAP
> + * interface but doesn't work on my box. So leave it disabled
> + * here as a reference if someone is going to pick that up in
> + * the future.
> + */
> +#if 0
> + struct ifreq ifr;
> +
> + memset(&ifr, 0, sizeof(ifr));
> + strncpy(ifr.ifr_name, "tap0", IFNAMSIZ);
> +
> + /* Get the interface flags */
> + if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
> + perror("Could not get interface flags");
> + return -1;
> + }
> + /* Shut down the interface */
> + ifr.ifr_flags &= ~(IFF_UP);
> + if (ioctl(fd, SIOCSIFFLAGS, &ifr) < 0) {
> + perror("Could not down the interface");
> + return -1;
> + }
> +
> + /* Set the new hw address */
> + ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
> + memcpy(&ifr.ifr_hwaddr.sa_data, hwaddr, ETH_ALEN);
> +
> + if (ioctl(fd, SIOCSIFHWADDR, &ifr) < 0) {
> + perror("ioctl(SIOCSIFHWADDR)");
> + return -1;
> + }
> +
> + /* Get the interface flags */
> + if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
> + perror("Could not get interface flags");
> + return -1;
> + }
> + /* Shut down the interface */
> + ifr.ifr_flags |= IFF_UP;
> + if (ioctl(fd, SIOCSIFFLAGS, &ifr) < 0) {
> + perror("Could not up the interface");
> + return -1;
> + }
> + return 0;
> +#endif
> + return -1;
> +}
> +#endif
> diff --git a/arch/sandbox/lib/board.c b/arch/sandbox/lib/board.c
> index b7997e9..d02f6ca 100644
> --- a/arch/sandbox/lib/board.c
> +++ b/arch/sandbox/lib/board.c
> @@ -257,6 +257,11 @@ void board_init_r(gd_t *id, ulong dest_addr)
> board_late_init();
> #endif
>
> +#if defined(CONFIG_CMD_NET)
> + puts("Net: ");
> + eth_initialize(gd->bd);
> +#endif
> +
> #ifdef CONFIG_POST
> post_run(NULL, POST_RAM | post_bootmode_get(0));
> #endif
> diff --git a/drivers/net/Makefile b/drivers/net/Makefile
> index d3df82e..914b1b7 100644
> --- a/drivers/net/Makefile
> +++ b/drivers/net/Makefile
> @@ -69,6 +69,7 @@ COBJS-$(CONFIG_SH_ETHER) += sh_eth.o
> COBJS-$(CONFIG_SMC91111) += smc91111.o
> COBJS-$(CONFIG_SMC911X) += smc911x.o
> COBJS-$(CONFIG_DRIVER_TI_EMAC) += davinci_emac.o
> +COBJS-$(CONFIG_NET_TAP) += tap.o
> COBJS-$(CONFIG_TSEC_ENET) += tsec.o fsl_mdio.o
> COBJS-$(CONFIG_FMAN_ENET) += fsl_mdio.o
> COBJS-$(CONFIG_TSI108_ETH) += tsi108_eth.o
> diff --git a/drivers/net/tap.c b/drivers/net/tap.c
> new file mode 100644
> index 0000000..c02bb1b
> --- /dev/null
> +++ b/drivers/net/tap.c
> @@ -0,0 +1,118 @@
> +/*
> + * tap.c - A tap ethernet driver for u-boot
> + *
> + * Copyright (c) 2011 Matthias Weißer <weisserm at arcor.de>
> + *
> + * Based on fec_mxc.c and tap.c from barebox:
> + * Copyright (c) 2007 Sascha Hauer <s.hauer at pengutronix.de>, Pengutronix
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2
> + * as published by the Free Software Foundation.
> + *
> + * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
> + */
> +
> +#include <common.h>
> +#include <malloc.h>
> +#include <errno.h>
> +#include <net.h>
> +#include <os.h>
> +
> +struct tap_priv {
> + int fd; /* file descriptor */
> +};
> +
> +static int tap_init(struct eth_device *dev, bd_t* bd)
> +{
> + /* Nothing to be done here */
> + return 0;
> +}
> +
> +static void tap_halt(struct eth_device *dev)
> +{
> + /* Nothing to be done here */
> +}
> +
> +static int tap_send(struct eth_device *dev, volatile void *packet, int length)
> +{
> + struct tap_priv *tap = dev->priv;
> +
> + os_write(tap->fd, (void *)packet, length);
check for os_write() failure?
> + return 0;
> +}
> +
> +static int tap_recv(struct eth_device *dev)
> +{
> + struct tap_priv *tap = dev->priv;
> + int length;
Use ssize_t here?
> +
> + length = (int)os_read(tap->fd, (void *)NetRxPackets[0], PKTSIZE);
> +
> + if (length > 0)
> + NetReceive(NetRxPackets[0], length);
> +
> + return 0;
> +}
> +
> +static int tap_set_hwaddr(struct eth_device *dev)
> +{
> + struct tap_priv *tap = dev->priv;
> +
> + return os_tap_set_hw_addr(tap->fd, dev->enetaddr);
> +}
> +
> +int tap_initialize(bd_t *bd, char * dname)
> +{
> + struct eth_device *dev;
> + struct tap_priv *tap;
> + int res = 0;
Perhaps set this to -1 until you get to the success path? Otherwise
you see success with err1 and err2 below.
> +
> + /* create and fill edev struct */
> + dev = malloc(sizeof(struct eth_device));
> + if (!dev)
> + goto err1;
> +
> + tap = malloc(sizeof(struct tap_priv));
> + if (!tap)
> + goto err2;
> +
> + memset(dev, 0, sizeof(*dev));
> + memset(tap, 0, sizeof(*tap));
> +
> + strncpy(dev->name, dname, sizeof(dev->name));
> + tap->fd = os_tap_open(dev->name, dev->enetaddr);
> + if (tap->fd < 0) {
> + res = -1;
> + goto err3;
> + }
> +
> + dev->priv = tap;
> + dev->init = tap_init;
> + dev->send = tap_send;
> + dev->recv = tap_recv;
> + dev->halt = tap_halt;
> + dev->write_hwaddr = tap_set_hwaddr;
> +
> + strncpy(dev->name, dname, sizeof(dev->name));
> + eth_register(dev);
> +
> + return res;
> +
> +err3:
> + free(tap);
> +err2:
> + free(dev);
> +err1:
> + return res;
> +}
> diff --git a/include/configs/sandbox.h b/include/configs/sandbox.h
> index 10565e6..33b1a19 100644
> --- a/include/configs/sandbox.h
> +++ b/include/configs/sandbox.h
> @@ -69,12 +69,13 @@
>
> #define CONFIG_SYS_NO_FLASH
>
> +/* Network support */
> +#define CONFIG_NET_TAP
> +
> /* include default commands */
> #include <config_cmd_default.h>
> -
> -/* We don't have networking support yet */
> -#undef CONFIG_CMD_NET
> -#undef CONFIG_CMD_NFS
> +#define CONFIG_CMD_DHCP
> +#define CONFIG_CMD_PING
>
> #define CONFIG_BOOTARGS ""
>
> diff --git a/include/netdev.h b/include/netdev.h
> index 04d9f75..25173a8 100644
> --- a/include/netdev.h
> +++ b/include/netdev.h
> @@ -100,6 +100,7 @@ int xilinx_axiemac_initialize(bd_t *bis, unsigned long base_addr,
> unsigned long dma_addr);
> int xilinx_emaclite_initialize(bd_t *bis, unsigned long base_addr,
> int txpp, int rxpp);
> +int tap_initialize(bd_t *bd, char * dname);
Can we please have arg/return comments on this new function?
>
> /* Boards with PCI network controllers can call this from their board_eth_init()
> * function to initialize whatever's on board.
> diff --git a/include/os.h b/include/os.h
> index f3af4f0..3b0c629 100644
> --- a/include/os.h
> +++ b/include/os.h
> @@ -98,3 +98,21 @@ void os_usleep(unsigned long usec);
> * \return A monotonic increasing time scaled in nano seconds
> */
> u64 os_get_nsec(void);
> +
> +/**
> + * Opens a TAP device for network emulation
> + *
> + * \param dev Device name to be opened
> + * \param hwaddr Ethernet address of interface is copied here (6 byte)
> + * \return File descriptor of the device
While I'm fine with \ I think U-Boot tends to use @.
> + */
> +int os_tap_open(const char *dev, unsigned char *hwaddr);
> +
> +/**
> + * Sets the hw address of a open tap interface
> + *
> + * \param fd The fd of the tap interface
> + * \param hwaddr The address to be set (6 byte)
> + * \return -1 if the hwaddr couldn't be set
or 0 on success?
> + */
> +int os_tap_set_hw_addr(int fd, unsigned char *hwaddr);
> --
> 1.7.5.4
>
Regards,
Simon
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