umka/linux/vnet/tap.c
Ivan Baravy e71791c0ab Implement vnet_null device
Such device don't need new threads and files but are valid ethernet
devices for the kernel. Convenient for testing.
2023-02-07 04:32:32 +00:00

137 lines
3.3 KiB
C

/*
SPDX-License-Identifier: GPL-2.0-or-later
UMKa - User-Mode KolibriOS developer tools
vnet - virtual network card, tap interface
Copyright (C) 2023 Ivan Baravy <dunkaist@gmail.com>
*/
#include <stdio.h>
#include <stdlib.h>
#include <fcntl.h>
#include <arpa/inet.h>
#include <linux/if.h>
#include <linux/if_tun.h>
#include <net/if_arp.h>
#include <sys/ioctl.h>
#include <unistd.h>
#include "trace.h"
#include "vnet.h"
#define TAP_DEV "/dev/net/tun"
#define UMKA_TAP_NAME "umka%d"
static STDCALL void
vnet_unload_tap(void) {
COVERAGE_ON();
COVERAGE_OFF();
}
static STDCALL void
vnet_reset_tap(void) {
COVERAGE_ON();
COVERAGE_OFF();
}
static STDCALL int
vnet_transmit_tap(net_buff_t *buf) {
struct vnet *net;
__asm__ __inline__ __volatile__ (
""
: "=b"(net)
:
: "memory");
ssize_t written = write(net->fdout, buf->data, buf->length);
(void)written;
buf->length = 0;
COVERAGE_OFF();
COVERAGE_ON();
return 0;
}
struct vnet *
vnet_init_tap(void) {
struct ifreq ifr = {.ifr_name = UMKA_TAP_NAME,
.ifr_flags = IFF_TAP | IFF_NO_PI};
int fd, err;
if( (fd = open(TAP_DEV, O_RDWR)) < 0 ) {
perror("Opening " TAP_DEV );
return NULL;
}
if( (err = ioctl(fd, TUNSETIFF, &ifr)) < 0 ) {
perror("ioctl(TUNSETIFF)");
close(fd);
return NULL;
}
ifr.ifr_hwaddr.sa_family = ARPHRD_ETHER;
memcpy(ifr.ifr_hwaddr.sa_data, (char[]){0x00, 0x11, 0x00, 0x00, 0x00, 0x00}, 6);
if( (err = ioctl(fd, SIOCSIFHWADDR, &ifr)) < 0 ) {
perror("ioctl(SIOCSIFHWADDR)");
close(fd);
return NULL;
}
struct sockaddr_in sai;
sai.sin_family = AF_INET;
sai.sin_port = 0;
sai.sin_addr.s_addr = inet_addr("10.50.0.1");
memcpy(&ifr.ifr_addr, &sai, sizeof(struct sockaddr));
int sockfd = socket(AF_INET, SOCK_DGRAM, 0);
if ( (err = ioctl(sockfd, SIOCSIFADDR, &ifr)) < 0 ) {
perror("ioctl(SIOCSIFADDR)");
close(fd);
return NULL;
}
sai.sin_addr.s_addr = inet_addr("255.255.255.0");
memcpy(&ifr.ifr_netmask, &sai, sizeof(struct sockaddr));
if ((err = ioctl(sockfd, SIOCSIFNETMASK, &ifr)) < 0) {
perror("ioctl(SIOCSIFNETMASK)");
close(fd);
return NULL;
}
if ((err = ioctl(sockfd, SIOCGIFFLAGS, &ifr)) < 0) {
perror("ioctl(SIOCGIFFLAGS)");
close(fd);
return NULL;
}
ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
ifr.ifr_flags &= ~(IFF_BROADCAST | IFF_LOWER_UP);
if ((err = ioctl(sockfd, SIOCSIFFLAGS, &ifr)) < 0) {
perror("ioctl(SIOCSIFFLAGS)");
close(fd);
return NULL;
}
struct vnet *vnet = malloc(sizeof(struct vnet));
vnet->eth.net.device_type = NET_TYPE_ETH;
vnet->eth.net.mtu = 1514;
char *devname = malloc(8);
sprintf(devname, "UMKTAP%d", 0); // FIXME: support more devices
vnet->eth.net.name = devname;
vnet->eth.net.unload = vnet_unload_tap;
vnet->eth.net.reset = vnet_reset_tap;
vnet->eth.net.transmit = vnet_transmit_tap;
vnet->fdin = fd;
vnet->fdout = fd;
vnet->input_processed = 1;
memcpy(vnet->eth.mac, (uint8_t[]){0x80, 0x2b, 0xf9, 0x3b, 0x6c, 0xca},
sizeof(vnet->eth.mac));
return vnet;
}