Archipelago » qemu

/*

 * QEMU System Emulator

 *

 * Copyright (c) 2003-2008 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#include "net/tap.h"

#include <sys/stat.h>

#include <sys/ethernet.h>

#include <sys/sockio.h>

#include <netinet/arp.h>

#include <netinet/in.h>

#include <netinet/in_systm.h>

#include <netinet/ip.h>

#include <netinet/ip_icmp.h> // must come after ip.h

#include <netinet/udp.h>

#include <netinet/tcp.h>

#include <net/if.h>

#include <syslog.h>

#include <stropts.h>

ssize_t tap_read_packet(int tapfd, uint8_t *buf, int maxlen)

{

    struct strbuf sbuf;

    int f = 0;

    sbuf.maxlen = maxlen;

    sbuf.buf = (char *)buf;

    return getmsg(tapfd, NULL, &sbuf, &f) >= 0 ? sbuf.len : -1;

}

#define TUNNEWPPA       (('T'<<16) | 0x0001)

/*

 * Allocate TAP device, returns opened fd.

 * Stores dev name in the first arg(must be large enough).

 */

static int tap_alloc(char *dev, size_t dev_size)

{

    int tap_fd, if_fd, ppa = -1;

    static int ip_fd = 0;

    char *ptr;

    static int arp_fd = 0;

    int ip_muxid, arp_muxid;

    struct strioctl  strioc_if, strioc_ppa;

    int link_type = I_PLINK;;

    struct lifreq ifr;

    char actual_name[32] = "";

    memset(&ifr, 0x0, sizeof(ifr));

    if( *dev ){

       ptr = dev;

       while( *ptr && !qemu_isdigit((int)*ptr) ) ptr++;

       ppa = atoi(ptr);

    }

    /* Check if IP device was opened */

    if( ip_fd )

       close(ip_fd);

    TFR(ip_fd = open("/dev/udp", O_RDWR, 0));

    if (ip_fd < 0) {

       syslog(LOG_ERR, "Can't open /dev/ip (actually /dev/udp)");

       return -1;

    }

    TFR(tap_fd = open("/dev/tap", O_RDWR, 0));

    if (tap_fd < 0) {

       syslog(LOG_ERR, "Can't open /dev/tap");

       return -1;

    }

    /* Assign a new PPA and get its unit number. */

    strioc_ppa.ic_cmd = TUNNEWPPA;

    strioc_ppa.ic_timout = 0;

    strioc_ppa.ic_len = sizeof(ppa);

    strioc_ppa.ic_dp = (char *)&ppa;

    if ((ppa = ioctl (tap_fd, I_STR, &strioc_ppa)) < 0)

       syslog (LOG_ERR, "Can't assign new interface");

    TFR(if_fd = open("/dev/tap", O_RDWR, 0));

    if (if_fd < 0) {

       syslog(LOG_ERR, "Can't open /dev/tap (2)");

       return -1;

    }

    if(ioctl(if_fd, I_PUSH, "ip") < 0){

       syslog(LOG_ERR, "Can't push IP module");

       return -1;

    }

    if (ioctl(if_fd, SIOCGLIFFLAGS, &ifr) < 0)

        syslog(LOG_ERR, "Can't get flags\n");

    snprintf (actual_name, 32, "tap%d", ppa);

    pstrcpy(ifr.lifr_name, sizeof(ifr.lifr_name), actual_name);

    ifr.lifr_ppa = ppa;

    /* Assign ppa according to the unit number returned by tun device */

    if (ioctl (if_fd, SIOCSLIFNAME, &ifr) < 0)

        syslog (LOG_ERR, "Can't set PPA %d", ppa);

    if (ioctl(if_fd, SIOCGLIFFLAGS, &ifr) <0)

        syslog (LOG_ERR, "Can't get flags\n");

    /* Push arp module to if_fd */

    if (ioctl (if_fd, I_PUSH, "arp") < 0)

        syslog (LOG_ERR, "Can't push ARP module (2)");

    /* Push arp module to ip_fd */

    if (ioctl (ip_fd, I_POP, NULL) < 0)

        syslog (LOG_ERR, "I_POP failed\n");

    if (ioctl (ip_fd, I_PUSH, "arp") < 0)

        syslog (LOG_ERR, "Can't push ARP module (3)\n");

    /* Open arp_fd */

    TFR(arp_fd = open ("/dev/tap", O_RDWR, 0));

    if (arp_fd < 0)

       syslog (LOG_ERR, "Can't open %s\n", "/dev/tap");

    /* Set ifname to arp */

    strioc_if.ic_cmd = SIOCSLIFNAME;

    strioc_if.ic_timout = 0;

    strioc_if.ic_len = sizeof(ifr);

    strioc_if.ic_dp = (char *)𝔦

    if (ioctl(arp_fd, I_STR, &strioc_if) < 0){

        syslog (LOG_ERR, "Can't set ifname to arp\n");

    }

    if((ip_muxid = ioctl(ip_fd, I_LINK, if_fd)) < 0){

       syslog(LOG_ERR, "Can't link TAP device to IP");

       return -1;

    }

    if ((arp_muxid = ioctl (ip_fd, link_type, arp_fd)) < 0)

        syslog (LOG_ERR, "Can't link TAP device to ARP");

    close (if_fd);

    memset(&ifr, 0x0, sizeof(ifr));

    pstrcpy(ifr.lifr_name, sizeof(ifr.lifr_name), actual_name);

    ifr.lifr_ip_muxid  = ip_muxid;

    ifr.lifr_arp_muxid = arp_muxid;

    if (ioctl (ip_fd, SIOCSLIFMUXID, &ifr) < 0)

    {

      ioctl (ip_fd, I_PUNLINK , arp_muxid);

      ioctl (ip_fd, I_PUNLINK, ip_muxid);

      syslog (LOG_ERR, "Can't set multiplexor id");

    }

    snprintf(dev, dev_size, "tap%d", ppa);

    return tap_fd;

}

int tap_open(char *ifname, int ifname_size, int *vnet_hdr, int vnet_hdr_required)

{

    char  dev[10]="";

    int fd;

    if( (fd = tap_alloc(dev, sizeof(dev))) < 0 ){

       fprintf(stderr, "Cannot allocate TAP device\n");

       return -1;

    }

    pstrcpy(ifname, ifname_size, dev);

    fcntl(fd, F_SETFL, O_NONBLOCK);

    return fd;

}