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#define _GNU_SOURCE
#include <arpa/inet.h>
#include <linux/if.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <string.h>
#include <signal.h>
#include <stdio.h>
#include <unistd.h>
#include "gnunet-vpn-helper-p.h"
#include "tun.h"
#ifndef _LINUX_IN6_H
// This is in linux/include/net/ipv6.h.
struct in6_ifreq {
struct in6_addr ifr6_addr;
__u32 ifr6_prefixlen;
unsigned int ifr6_ifindex;
};
#endif
int running = 1;
void term(int sig) {
fprintf(stderr, "Got SIGTERM...\n");
if (sig == SIGTERM)
running = 0;
}
static void set_address(char* dev, char* address, unsigned long prefix_len) { /* {{{ */
int fd = socket(AF_INET6, SOCK_DGRAM, 0);
struct ifreq ifr;
struct in6_ifreq ifr6;
struct sockaddr_in6 sa6;
memset(&sa6, 0, sizeof(struct sockaddr_in6));
sa6.sin6_family = AF_INET6;
/* FIXME */ inet_pton(AF_INET6, address, sa6.sin6_addr.s6_addr);
memcpy((char *) &ifr6.ifr6_addr, (char *) &sa6.sin6_addr, sizeof(struct in6_addr));
strncpy(ifr.ifr_name, dev, IFNAMSIZ);
if (ioctl(fd, SIOGIFINDEX, &ifr) < 0) {
perror("SIOGIFINDEX");
}
ifr6.ifr6_ifindex = ifr.ifr_ifindex;
ifr6.ifr6_prefixlen = prefix_len;
if (ioctl(fd, SIOCSIFADDR, &ifr6) < 0) {
perror("SIOCSIFADDR");
}
/* FIXME */ ioctl(fd, SIOCGIFFLAGS, &ifr);
ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
/* FIXME */ ioctl(fd, SIOCSIFFLAGS, &ifr);
} /* }}} */
void setnonblocking(int fd) {
int opts;
opts = fcntl(fd,F_GETFL);
if (opts < 0) {
perror("fcntl(F_GETFL)");
}
opts = (opts | O_NONBLOCK);
if (fcntl(fd,F_SETFL,opts) < 0) {
perror("fcntl(F_SETFL)");
}
return;
}
static int copy (int in, int out) {
unsigned char buf[65600]; // 64k + 64;
int r = read(in, buf, 65600);
int w = 0;
if (r < 0) return r;
while (w < r) {
int t = write(out, buf + w, r - w);
if (t > 0) w += t;
if (t < 0) return t;
}
return 0;
}
int main(int argc, char** argv) {
char dev[IFNAMSIZ];
memset(dev, 0, IFNAMSIZ);
signal(SIGTERM, &term);
int fd_tun = init_tun(dev);
fprintf(stderr, "Initialized the interface %s as %d.\n", dev, fd_tun);
// TODO: get this out of argv
char address[] = "1234::1";
unsigned long prefix_len = 8;
set_address(dev, address, prefix_len);
uid_t uid = getuid ();
if (setresuid (uid, uid, uid) != 0 )
fprintf (stderr, "Failed to setresuid: %m\n");
setnonblocking(0);
setnonblocking(1);
setnonblocking(fd_tun);
fd_set fds_w;
fd_set fds_r;
int r = 1;
int w = 1;
while(r != 0 && w != 0 && running == 1) {
FD_ZERO(&fds_w);
FD_ZERO(&fds_r);
if (r) {
FD_SET(fd_tun, &fds_r);
FD_SET(1, &fds_w);
}
if (w) {
FD_SET(0, &fds_r);
FD_SET(fd_tun, &fds_w);
}
int r = select(fd_tun+1, &fds_r, &fds_w, (fd_set*)0, 0);
if(r > 0) {
if (FD_ISSET(0, &fds_r) && FD_ISSET(fd_tun, &fds_w)) {
if (copy(0, fd_tun) < 0) {
fprintf(stderr, "Closing Write\n");
shutdown(fd_tun, SHUT_WR);
w = 0;
}
} else if (FD_ISSET(1, &fds_w) && FD_ISSET(fd_tun, &fds_r)) {
if (copy(fd_tun, 1) < 0) {
fprintf(stderr, "Closing Read\n");
shutdown(fd_tun, SHUT_RD);
r = 0;
}
}
}
}
fprintf(stderr, "Quitting!\n");
return 0;
}
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