Shuttle data back and forth

1 files changed, 56 insertions, 2 deletions

diff --git a/src/vpn/gnunet-vpn-helper.c b/src/vpn/gnunet-vpn-helper.c
index 66af3ca51..a5a569b9a 100644
--- a/src/vpn/gnunet-vpn-helper.c
+++ b/src/vpn/gnunet-vpn-helper.c
@@ -2,6 +2,8 @@
 #include <arpa/inet.h>
 #include <linux/if.h>
 
+#include <fcntl.h>
+
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
@@ -58,6 +60,34 @@ static void set_address(char* dev, char* address, unsigned long prefix_len) { /*
         /* 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);
@@ -75,8 +105,32 @@ int main(int argc, char** argv) {
         if (setresuid (uid, uid, uid) != 0 )
                 fprintf (stderr, "Failed to setresuid: %m\n");
 
-        // Wait
-        read(0, dev, 10);
+        setnonblocking(0);
+        setnonblocking(1);
+        setnonblocking(fd_tun);
+
+        fd_set fds_w;
+        fd_set fds_r;
+        for(;;) {
+                FD_ZERO(&fds_w);
+                FD_ZERO(&fds_r);
+
+                FD_SET(0, &fds_r);
+                FD_SET(fd_tun, &fds_r);
+
+                FD_SET(1, &fds_w);
+                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)) {
+                                copy(0, fd_tun);
+                        } else if (FD_ISSET(1, &fds_w) && FD_ISSET(fd_tun, &fds_r)) {
+                                copy(fd_tun, 1);
+                        }
+                }
+        }
 
         return 0;
 }