Logo Search packages:      
Sourcecode: linux version File versions  Download package

ethertap_user.c

/*
 * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
 * James Leu (jleu@mindspring.net).
 * Copyright (C) 2001 by various other people who didn't put their name here.
 * Licensed under the GPL.
 */

#include <stdio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include "etap.h"
#include "kern_constants.h"
#include "os.h"
#include "net_user.h"
#include "um_malloc.h"
#include "user.h"

#define MAX_PACKET ETH_MAX_PACKET

static int etap_user_init(void *data, void *dev)
{
      struct ethertap_data *pri = data;

      pri->dev = dev;
      return 0;
}

struct addr_change {
      enum { ADD_ADDR, DEL_ADDR } what;
      unsigned char addr[4];
      unsigned char netmask[4];
};

static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
                  int fd)
{
      struct addr_change change;
      char *output;
      int n;

      change.what = op;
      memcpy(change.addr, addr, sizeof(change.addr));
      memcpy(change.netmask, netmask, sizeof(change.netmask));
      CATCH_EINTR(n = write(fd, &change, sizeof(change)));
      if (n != sizeof(change)) {
            printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
                   errno);
            return;
      }

      output = kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
      if (output == NULL)
            printk(UM_KERN_ERR "etap_change : Failed to allocate output "
                   "buffer\n");
      read_output(fd, output, UM_KERN_PAGE_SIZE);
      if (output != NULL) {
            printk("%s", output);
            kfree(output);
      }
}

static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
                     void *arg)
{
      etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
}

static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
                      void *arg)
{
      etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
}

struct etap_pre_exec_data {
      int control_remote;
      int control_me;
      int data_me;
};

static void etap_pre_exec(void *arg)
{
      struct etap_pre_exec_data *data = arg;

      dup2(data->control_remote, 1);
      close(data->data_me);
      close(data->control_me);
}

static int etap_tramp(char *dev, char *gate, int control_me,
                  int control_remote, int data_me, int data_remote)
{
      struct etap_pre_exec_data pe_data;
      int pid, err, n;
      char version_buf[sizeof("nnnnn\0")];
      char data_fd_buf[sizeof("nnnnnn\0")];
      char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
      char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
                         data_fd_buf, gate_buf, NULL };
      char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
                         dev, data_fd_buf, NULL };
      char **args, c;

      sprintf(data_fd_buf, "%d", data_remote);
      sprintf(version_buf, "%d", UML_NET_VERSION);
      if (gate != NULL) {
            strcpy(gate_buf, gate);
            args = setup_args;
      }
      else args = nosetup_args;

      err = 0;
      pe_data.control_remote = control_remote;
      pe_data.control_me = control_me;
      pe_data.data_me = data_me;
      pid = run_helper(etap_pre_exec, &pe_data, args);

      if (pid < 0)
            err = pid;
      close(data_remote);
      close(control_remote);
      CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
      if (n != sizeof(c)) {
            err = -errno;
            printk(UM_KERN_ERR "etap_tramp : read of status failed, "
                   "err = %d\n", -err);
            return err;
      }
      if (c != 1) {
            printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
            err = helper_wait(pid, 0, "uml_net");
      }
      return err;
}

static int etap_open(void *data)
{
      struct ethertap_data *pri = data;
      char *output;
      int data_fds[2], control_fds[2], err, output_len;

      err = tap_open_common(pri->dev, pri->gate_addr);
      if (err)
            return err;

      err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
      if (err) {
            err = -errno;
            printk(UM_KERN_ERR "etap_open - data socketpair failed - "
                   "err = %d\n", errno);
            return err;
      }

      err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
      if (err) {
            err = -errno;
            printk(UM_KERN_ERR "etap_open - control socketpair failed - "
                   "err = %d\n", errno);
            goto out_close_data;
      }

      err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
                   control_fds[1], data_fds[0], data_fds[1]);
      output_len = UM_KERN_PAGE_SIZE;
      output = kmalloc(output_len, UM_GFP_KERNEL);
      read_output(control_fds[0], output, output_len);

      if (output == NULL)
            printk(UM_KERN_ERR "etap_open : failed to allocate output "
                   "buffer\n");
      else {
            printk("%s", output);
            kfree(output);
      }

      if (err < 0) {
            printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
            goto out_close_control;
      }

      pri->data_fd = data_fds[0];
      pri->control_fd = control_fds[0];
      iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
      return data_fds[0];

out_close_control:
      close(control_fds[0]);
      close(control_fds[1]);
out_close_data:
      close(data_fds[0]);
      close(data_fds[1]);
      return err;
}

static void etap_close(int fd, void *data)
{
      struct ethertap_data *pri = data;

      iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
      close(fd);

      if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
            printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
                   "errno = %d\n", errno);

      if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
            printk(UM_KERN_ERR "etap_close - shutdown control socket "
                   "failed, errno = %d\n", errno);

      close(pri->data_fd);
      pri->data_fd = -1;
      close(pri->control_fd);
      pri->control_fd = -1;
}

static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
                    void *data)
{
      struct ethertap_data *pri = data;

      tap_check_ips(pri->gate_addr, addr);
      if (pri->control_fd == -1)
            return;
      etap_open_addr(addr, netmask, &pri->control_fd);
}

static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
                    void *data)
{
      struct ethertap_data *pri = data;

      if (pri->control_fd == -1)
            return;

      etap_close_addr(addr, netmask, &pri->control_fd);
}

const struct net_user_info ethertap_user_info = {
      .init       = etap_user_init,
      .open       = etap_open,
      .close            = etap_close,
      .remove           = NULL,
      .add_address      = etap_add_addr,
      .delete_address = etap_del_addr,
      .mtu        = ETH_MAX_PACKET,
      .max_packet = ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
};

Generated by  Doxygen 1.6.0   Back to index