Bochs/bochs/iodev/network/eth_tap.cc
2022-08-23 21:46:04 +03:00

446 lines
14 KiB
C++

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2001-2021 The Bochs Project
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public
// License as published by the Free Software Foundation; either
// version 2 of the License, or (at your option) any later version.
//
// This library 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
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////
// eth_tap.cc - TAP interface by Bryce Denney
//
// Here's how to get this working. On the host machine:
// $ su root
// # /sbin/insmod ethertap
// Using /lib/modules/2.2.14-5.0/net/ethertap.o
// # mknod /dev/tap0 c 36 16 # if not already there
// # /sbin/ifconfig tap0 10.0.0.1
// # /sbin/route add -host 10.0.0.2 gw 10.0.0.1
//
// Now you have a tap0 device which you can on the ifconfig output. The
// tap0 interface has the IP address of 10.0.0.1. The bochs machine will have
// the IP address 10.0.0.2.
//
// Compile a bochs version from March 8, 2002 or later with --enable-ne2000.
// Add this ne2k line to your .bochsrc to activate the tap device.
// ne2k: ioaddr=0x280, irq=9, mac=fe:fd:00:00:00:01, ethmod=tap, ethdev=tap0
// Don't change the mac or ethmod!
//
// Boot up DLX Linux in Bochs. Log in as root and then type the following
// commands to set up networking:
// # ifconfig eth0 10.0.0.2
// # route add -net 10.0.0.0
// # route add default gw 10.0.0.1
// Now you should be able to ping from guest OS to your host machine, if
// you give its IP number. I'm still having trouble with pings from the
// host machine to the guest, so something is still not right. Symptoms: I
// ping from the host to the guest's IP address 10.0.0.2. With tcpdump I can
// see the ping going to Bochs, and then the ping reply coming from Bochs.
// But the ping program itself does not see the responses....well every
// once in a while it does, like 1 in 60 pings.
//
// host$ ping 10.0.0.2
// PING 10.0.0.2 (10.0.0.2) from 10.0.0.1 : 56(84) bytes of data.
//
// Netstat output:
// 20:29:59.018776 fe:fd:0:0:0:0 fe:fd:0:0:0:1 0800 98: 10.0.0.1 > 10.0.0.2: icmp: echo request
// 4500 0054 2800 0000 4001 3ea7 0a00 0001
// 0a00 0002 0800 09d3 a53e 0400 9765 893c
// 3949 0000 0809 0a0b 0c0d 0e0f 1011 1213
// 1415 1617 1819
// 20:29:59.023017 fe:fd:0:0:0:1 fe:fd:0:0:0:0 0800 98: 10.0.0.2 > 10.0.0.1: icmp: echo reply
// 4500 0054 004a 0000 4001 665d 0a00 0002
// 0a00 0001 0000 11d3 a53e 0400 9765 893c
// 3949 0000 0809 0a0b 0c0d 0e0f 1011 1213
// 1415 1617 1819
//
// I suspect it may be related to the fact that ping 10.0.0.1 from the
// host also doesn't work. Why wouldn't the host respond to its own IP
// address on the tap0 device?
//
// Theoretically, if you set up packet forwarding (with masquerading) on the
// host, you should be able to get Bochs talking to anyone on the internet.
//
// Pavel Dufek (PD), CZ, 2008 - quick & dirty hack for Solaris 10 sparc tap
// ala Qemu.
// Define BX_PLUGGABLE in files that can be compiled into plugins. For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.
#define BX_PLUGGABLE
#include "bochs.h"
#include "plugin.h"
#include "pc_system.h"
#include "netmod.h"
#if BX_NETWORKING && BX_NETMOD_TAP
// network driver plugin entry point
PLUGIN_ENTRY_FOR_NET_MODULE(tap)
{
if (mode == PLUGIN_PROBE) {
return (int)PLUGTYPE_NET;
}
return 0; // Success
}
// network driver implementation
#define LOG_THIS netdev->
#include <signal.h>
#include <sys/param.h>
#include <sys/ioctl.h>
#ifndef __APPLE__
#include <sys/poll.h>
#endif
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/wait.h>
#if defined(__linux__)
#include <asm/types.h>
#include <linux/netlink.h>
#include <linux/if.h>
#elif BX_HAVE_NET_IF_H
#include <net/if.h>
#endif
#include <assert.h>
#include <fcntl.h>
#include <errno.h>
#if defined(__sun__)
// Sun/Solaris specific defines/includes
#define TUNNEWPPA (('T'<<16) | 0x0001)
#include <stropts.h>
#endif
#define BX_ETH_TAP_LOGGING 0
//
// Define the class. This is private to this module
//
class bx_tap_pktmover_c : public eth_pktmover_c {
public:
bx_tap_pktmover_c(const char *netif, const char *macaddr,
eth_rx_handler_t rxh, eth_rx_status_t rxstat,
logfunctions *netdev, const char *script);
virtual ~bx_tap_pktmover_c();
void sendpkt(void *buf, unsigned io_len);
private:
int fd;
int rx_timer_index;
static void rx_timer_handler(void *);
void rx_timer ();
Bit8u guest_macaddr[6];
#if BX_ETH_TAP_LOGGING
FILE *txlog, *txlog_txt, *rxlog, *rxlog_txt;
#endif
};
//
// Define the static class that registers the derived pktmover class,
// and allocates one on request.
//
class bx_tap_locator_c : public eth_locator_c {
public:
bx_tap_locator_c(void) : eth_locator_c("tap") {}
protected:
eth_pktmover_c *allocate(const char *netif, const char *macaddr,
eth_rx_handler_t rxh, eth_rx_status_t rxstat,
logfunctions *netdev, const char *script) {
return (new bx_tap_pktmover_c(netif, macaddr, rxh, rxstat, netdev, script));
}
} bx_tap_match;
//
// Define the methods for the bx_tap_pktmover derived class
//
// the constructor
bx_tap_pktmover_c::bx_tap_pktmover_c(const char *netif,
const char *macaddr,
eth_rx_handler_t rxh,
eth_rx_status_t rxstat,
logfunctions *netdev,
const char *script)
{
int flags;
char filename[BX_PATHNAME_LEN];
this->netdev = netdev;
if (strncmp (netif, "tap", 3) != 0) {
BX_PANIC(("eth_tap: interface name (%s) must be tap0..tap15", netif));
}
#if defined(__sun__)
strcpy(filename,"/dev/tap"); /* PD - device on Solaris is always the same */
#else
sprintf(filename, "/dev/%s", netif);
#endif
#if defined(__linux__)
// check if the TAP devices is running, and turn on ARP. This is based
// on code from the Mac-On-Linux project. http://http://www.maconlinux.org/
int sock = socket(AF_INET, SOCK_DGRAM, 0);
if (sock < 0) {
BX_PANIC(("socket creation: %s", strerror(errno)));
return;
}
struct ifreq ifr;
memset(&ifr, 0, sizeof(ifr));
strncpy(ifr.ifr_name, netif, sizeof(ifr.ifr_name));
if(ioctl(sock, SIOCGIFFLAGS, &ifr) < 0) {
BX_PANIC(("SIOCGIFFLAGS on %s: %s", netif, strerror(errno)));
close(sock);
return;
}
if (!(ifr.ifr_flags & IFF_RUNNING)) {
BX_PANIC(("%s device is not running", netif));
close(sock);
return;
}
if ((ifr.ifr_flags & IFF_NOARP)){
BX_INFO(("turn on ARP for %s device", netif));
ifr.ifr_flags &= ~IFF_NOARP;
if (ioctl(sock, SIOCSIFFLAGS, &ifr) < 0) {
BX_PANIC(("SIOCSIFFLAGS: %s", strerror(errno)));
close(sock);
return;
}
}
close(sock);
#endif
fd = open (filename, O_RDWR);
if (fd < 0) {
BX_PANIC(("open failed on TAP %s: %s", netif, strerror(errno)));
return;
}
#if defined(__sun__)
char *ptr; /* PD - ppa allocation ala qemu */
char my_dev[10]; /* enough ... */
int ppa=-1;
struct strioctl strioc_ppa;
my_dev[10-1]=0;
strncpy(my_dev,netif,10); /* following ptr= does not work with const char* */
if( *my_dev ) { /* find the ppa number X from string tapX */
ptr = my_dev;
while( *ptr && !isdigit((int)*ptr) ) ptr++;
ppa = atoi(ptr);
}
/* 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 (fd, I_STR, &strioc_ppa)) < 0)
BX_PANIC(("Can't assign new interface tap%d !",ppa));
#endif
/* set O_ASYNC flag so that we can poll with read() */
if ((flags = fcntl(fd, F_GETFL)) < 0) {
BX_PANIC(("getflags on tap device: %s", strerror(errno)));
}
flags |= O_NONBLOCK;
if (fcntl(fd, F_SETFL, flags) < 0) {
BX_PANIC(("set tap device flags: %s", strerror(errno)));
}
BX_INFO(("tap network drive: opened %s device", netif));
/* Execute the configuration script */
char intname[IFNAMSIZ];
strcpy(intname,netif);
if((script != NULL) && (strcmp(script, "") != 0) && (strcmp(script, "none") != 0))
{
if (execute_script(this->netdev, script, intname) < 0)
BX_ERROR(("execute script '%s' on %s failed", script, intname));
}
// Start the rx poll
this->rx_timer_index =
DEV_register_timer(this, this->rx_timer_handler, 1000, 1, 1,
"eth_tap"); // continuous, active
this->rxh = rxh;
this->rxstat = rxstat;
memcpy(&guest_macaddr[0], macaddr, 6);
#if BX_ETH_TAP_LOGGING
// eventually Bryce wants txlog to dump in pcap format so that
// tcpdump -r FILE can read it and interpret packets.
txlog = fopen("eth_tap-tx.log", "wb");
if (!txlog) BX_PANIC(("open eth_tap-tx.log failed"));
txlog_txt = fopen("eth_tap-txdump.txt", "wb");
if (!txlog_txt) BX_PANIC(("open eth_tap-txdump.txt failed"));
fprintf(txlog_txt, "tap packetmover readable log file\n");
fprintf(txlog_txt, "net IF = %s\n", netif);
fprintf(txlog_txt, "MAC address = ");
for (int i=0; i<6; i++)
fprintf(txlog_txt, "%02x%s", 0xff & macaddr[i], i<5?":" : "");
fprintf(txlog_txt, "\n--\n");
fflush(txlog_txt);
rxlog = fopen("eth_tap-rx.log", "wb");
if (!rxlog) BX_PANIC(("open eth_tap-rx.log failed"));
rxlog_txt = fopen("eth_tap-rxdump.txt", "wb");
if (!rxlog_txt) BX_PANIC(("open eth_tap-rxdump.txt failed"));
fprintf(rxlog_txt, "tap packetmover readable log file\n");
fprintf(rxlog_txt, "net IF = %s\n", netif);
fprintf(rxlog_txt, "MAC address = ");
for (int i=0; i<6; i++)
fprintf(rxlog_txt, "%02x%s", 0xff & macaddr[i], i<5?":" : "");
fprintf(rxlog_txt, "\n--\n");
fflush(rxlog_txt);
#endif
}
bx_tap_pktmover_c::~bx_tap_pktmover_c()
{
#if BX_ETH_TAP_LOGGING
fclose(txlog);
fclose(txlog_txt);
fclose(rxlog);
fclose(rxlog_txt);
#endif
}
void bx_tap_pktmover_c::sendpkt(void *buf, unsigned io_len)
{
Bit8u txbuf[BX_PACKET_BUFSIZE];
txbuf[0] = 0;
txbuf[1] = 0;
unsigned int size;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || \
defined(__APPLE__) || defined(__OpenBSD__) || defined(__sun__) // Should be fixed for other *BSD
memcpy(txbuf, buf, io_len);
/* PD - for Sun variant the retry cycle from qemu - mainly to be sure packet
is really out */
#if defined(__sun__)
int ret;
for(;;) {
ret=write(fd, txbuf, io_len);
if (ret < 0 && (errno == EINTR || errno == EAGAIN)) {
} else {
size=ret;
break;
}
}
#else /* not defined __sun__ */
size = write(fd, txbuf, io_len);
#endif /* whole condition about defined __sun__ */
if (size != io_len) {
#else /* not bsd/apple/sun style */
memcpy(txbuf+2, buf, io_len);
size = write(fd, txbuf, io_len+2);
if (size != io_len+2) {
#endif
BX_PANIC(("write on tap device: %s", strerror(errno)));
} else {
BX_DEBUG(("wrote %d bytes + ev. 2 byte pad on tap", io_len));
}
#if BX_ETH_TAP_LOGGING
BX_DEBUG(("sendpkt length %u", io_len));
// dump raw bytes to a file, eventually dump in pcap format so that
// tcpdump -r FILE can interpret them for us.
int n = fwrite(buf, io_len, 1, txlog);
if (n != 1) BX_ERROR(("fwrite to txlog failed, io_len = %u", io_len));
// dump packet in hex into an ascii log file
write_pktlog_txt(txlog_txt, (const Bit8u *)buf, io_len, 0);
// flush log so that we see the packets as they arrive w/o buffering
fflush(txlog);
#endif
}
void bx_tap_pktmover_c::rx_timer_handler(void *this_ptr)
{
bx_tap_pktmover_c *class_ptr = (bx_tap_pktmover_c *) this_ptr;
class_ptr->rx_timer();
}
void bx_tap_pktmover_c::rx_timer()
{
int nbytes;
Bit8u buf[BX_PACKET_BUFSIZE];
Bit8u *rxbuf;
if (fd<0) return;
#if defined(__sun__)
struct strbuf sbuf;
int f = 0;
sbuf.maxlen = sizeof(buf);
sbuf.buf = (char *)buf;
nbytes = getmsg(fd, NULL, &sbuf, &f) >=0 ? sbuf.len : -1;
#else
nbytes = read (fd, buf, sizeof(buf));
#endif
// hack: discard first two bytes
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) || defined(__APPLE__) || defined(__sun__) // Should be fixed for other *BSD
rxbuf = buf;
#else
rxbuf = buf+2;
nbytes-=2;
#endif
#if defined(__linux__)
// hack: TAP device likes to create an ethernet header which has
// the same source and destination address FE:FD:00:00:00:00.
// Change the dest address to FE:FD:00:00:00:01.
if (!memcmp(&rxbuf[0], &rxbuf[6], 6)) {
rxbuf[5] = guest_macaddr[5];
}
#endif
if (nbytes>0)
BX_DEBUG(("tap read returned %d bytes", nbytes));
if (nbytes<0) {
if (errno != EAGAIN)
BX_ERROR(("tap read error: %s", strerror(errno)));
return;
}
#if BX_ETH_TAP_LOGGING
if (nbytes > 0) {
BX_DEBUG(("receive packet length %u", nbytes));
// dump raw bytes to a file, eventually dump in pcap format so that
// tcpdump -r FILE can interpret them for us.
int n = fwrite(rxbuf, nbytes, 1, rxlog);
if (n != 1) BX_ERROR(("fwrite to rxlog failed, nbytes = %d", nbytes));
// dump packet in hex into an ascii log file
write_pktlog_txt(rxlog_txt, rxbuf, nbytes, 1);
// flush log so that we see the packets as they arrive w/o buffering
fflush(rxlog);
}
#endif
BX_DEBUG(("eth_tap: got packet: %d bytes, dst=%x:%x:%x:%x:%x:%x, src=%x:%x:%x:%x:%x:%x\n", nbytes, rxbuf[0], rxbuf[1], rxbuf[2], rxbuf[3], rxbuf[4], rxbuf[5], rxbuf[6], rxbuf[7], rxbuf[8], rxbuf[9], rxbuf[10], rxbuf[11]));
if (nbytes < MIN_RX_PACKET_LEN) {
BX_INFO(("packet too short (%d), padding to %d", nbytes, MIN_RX_PACKET_LEN));
nbytes = MIN_RX_PACKET_LEN;
}
if (this->rxstat(this->netdev) & BX_NETDEV_RXREADY) {
this->rxh(this->netdev, rxbuf, nbytes);
} else {
BX_ERROR(("device not ready to receive data"));
}
}
#endif /* if BX_NETWORKING && BX_NETMOD_TAP */