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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;
}/*}}}*/
int main(int argc, char** argv) {
unsigned char buf[65600]; // 64k + 64;
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 rea = 1;
int wri = 1;
outer:
while(rea != 0 && wri != 0 && running == 1) {
FD_ZERO(&fds_w);
FD_ZERO(&fds_r);
if (rea) {
FD_SET(fd_tun, &fds_r);
FD_SET(1, &fds_w);
}
if (wri) {
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)) {
struct suid_packet *pkt = (struct suid_packet*) buf;
r = read(0, buf, sizeof(struct suid_packet_header));
if (r < 0) {
fprintf(stderr, "read-error: %m\n");
shutdown(fd_tun, SHUT_WR);
shutdown(0, SHUT_RD);
wri=0;
goto outer;
}
r = 0;
while (r < ntohl(pkt->hdr.size)) {
int t = read(0, buf + r, ntohl(pkt->hdr.size) - r);
if (r < 0) {
fprintf(stderr, "read-error: %m\n");
shutdown(fd_tun, SHUT_WR);
shutdown(0, SHUT_RD);
wri=0;
goto outer;
}
r += t;
}
r = 0;
while (r < ntohl(pkt->hdr.size) - sizeof(struct suid_packet_header)) {
int t = write(fd_tun, pkt->data, ntohl(pkt->hdr.size) - sizeof(struct suid_packet_header) - r);
if (t < 0) {
fprintf(stderr, "write-error 3: %m\n");
shutdown(fd_tun, SHUT_WR);
shutdown(0, SHUT_RD);
wri = 0;
goto outer;
}
r += t;
}
} else if (FD_ISSET(1, &fds_w) && FD_ISSET(fd_tun, &fds_r)) {
r = read(fd_tun, buf, 65600);
if (r < 0) {
fprintf(stderr, "read-error: %m\n");
shutdown(fd_tun, SHUT_RD);
shutdown(1, SHUT_WR);
rea = 0;
goto outer;
}
struct suid_packet_header hdr = { .size = htonl(r + sizeof(struct suid_packet_header))};
r = 0;
while(r < sizeof(struct suid_packet_header)) {
int t = write(1, &hdr, sizeof(struct suid_packet_header) - r);
if (t < 0) {
fprintf(stderr, "write-error 2: %m\n");
shutdown(fd_tun, SHUT_RD);
shutdown(1, SHUT_WR);
rea = 0;
goto outer;
}
r += t;
}
while(r < ntohl(hdr.size)) {
int t = write(1, buf, ntohl(hdr.size) - r);
if (t < 0) {
fprintf(stderr, "write-error 1: %m, written %d/%d\n", r, ntohl(hdr.size));
shutdown(fd_tun, SHUT_RD);
shutdown(1, SHUT_WR);
rea = 0;
goto outer;
}
r += t;
}
}
}
}
fprintf(stderr, "Quitting!\n");
return 0;
}
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