/* * Copyright (C) 2010 Piotr Jaroszyński * * 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 #include #include #include #include #include #include #include #include #include #include #include #include /* This hack prevents pre-2.6.32 headers from redefining struct sockaddr */ #define _SYS_SOCKET_H #define __GLIBC__ 2 #include #undef __GLIBC__ #include #include #include #define RX_BUF_SIZE 1536 #define RX_QUOTA 4 /** @file * * The TAP driver. * * The TAP is a Virtual Ethernet network device. */ struct tap_nic { /** Tap interface name */ char * interface; /** File descriptor of the opened tap device */ int fd; }; /** Open the TAP device */ static int tap_open(struct net_device * netdev) { struct tap_nic * nic = netdev->priv; struct ifreq ifr; int ret; nic->fd = linux_open("/dev/net/tun", O_RDWR); if (nic->fd < 0) { DBGC(nic, "tap %p open('/dev/net/tun') = %d (%s)\n", nic, nic->fd, linux_strerror(linux_errno)); return nic->fd; } memset(&ifr, 0, sizeof(ifr)); /* IFF_NO_PI for no extra packet information */ ifr.ifr_flags = IFF_TAP | IFF_NO_PI; strncpy(ifr.ifr_name, nic->interface, IFNAMSIZ); DBGC(nic, "tap %p interface = '%s'\n", nic, nic->interface); ret = linux_ioctl(nic->fd, TUNSETIFF, &ifr); if (ret != 0) { DBGC(nic, "tap %p ioctl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno)); linux_close(nic->fd); return ret; } /* Set nonblocking mode to make tap_poll easier */ ret = linux_fcntl(nic->fd, F_SETFL, O_NONBLOCK); if (ret != 0) { DBGC(nic, "tap %p fcntl(%d, ...) = %d (%s)\n", nic, nic->fd, ret, linux_strerror(linux_errno)); linux_close(nic->fd); return ret; } return 0; } /** Close the TAP device */ static void tap_close(struct net_device *netdev) { struct tap_nic * nic = netdev->priv; linux_close(nic->fd); } /** * Transmit an ethernet packet. * * The packet can be written to the TAP device and marked as complete immediately. */ static int tap_transmit(struct net_device *netdev, struct io_buffer *iobuf) { struct tap_nic * nic = netdev->priv; int rc; /* Pad and align packet */ iob_pad(iobuf, ETH_ZLEN); rc = linux_write(nic->fd, iobuf->data, iobuf->tail - iobuf->data); DBGC2(nic, "tap %p wrote %d bytes\n", nic, rc); netdev_tx_complete(netdev, iobuf); return 0; } /** Poll for new packets */ static void tap_poll(struct net_device *netdev) { struct tap_nic * nic = netdev->priv; struct pollfd pfd; struct io_buffer * iobuf; unsigned int quota = RX_QUOTA; int r; pfd.fd = nic->fd; pfd.events = POLLIN; if (linux_poll(&pfd, 1, 0) == -1) { DBGC(nic, "tap %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 (quota-- && ((r = linux_read(nic->fd, iobuf->data, RX_BUF_SIZE)) > 0)) { DBGC2(nic, "tap %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, "tap %p alloc_iob failed\n", nic); } /** * Set irq. * * Not used on linux, provide a dummy implementation. */ static void tap_irq(struct net_device *netdev, int enable) { struct tap_nic *nic = netdev->priv; DBGC(nic, "tap %p irq enable = %d\n", nic, enable); } /** Tap operations */ static struct net_device_operations tap_operations = { .open = tap_open, .close = tap_close, .transmit = tap_transmit, .poll = tap_poll, .irq = tap_irq, }; /** Handle a device request for the tap driver */ static int tap_probe(struct linux_device *device, struct linux_device_request *request) { struct linux_setting *if_setting; struct net_device *netdev; struct tap_nic *nic; int rc; netdev = alloc_etherdev(sizeof(*nic)); if (! netdev) return -ENOMEM; netdev_init(netdev, &tap_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("tap missing a mandatory if setting\n"); rc = -EINVAL; goto err_settings; } nic->interface = if_setting->value; snprintf ( device->dev.name, sizeof ( device->dev.name ), "%s", nic->interface ); device->dev.desc.bus_type = BUS_TYPE_TAP; 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 tap_remove(struct linux_device *device) { struct net_device *netdev = linux_get_drvdata(device); unregister_netdev(netdev); netdev_nullify(netdev); netdev_put(netdev); } /** Tap linux_driver */ struct linux_driver tap_driver __linux_driver = { .name = "tap", .probe = tap_probe, .remove = tap_remove, .can_probe = 1, };