clatd: change to pass in tun filedescriptor via command lineandroid-mainline-10.0.0_r9android-mainline-10.0.0_r7android-mainline-10.0.0_r5android-mainline-10.0.0_r4android-mainline-10.0.0_r10android-10.0.0_r9android-10.0.0_r8android-10.0.0_r7android-10.0.0_r45android-10.0.0_r44android-10.0.0_r43android-10.0.0_r42android-10.0.0_r41android-10.0.0_r40android-10.0.0_r39android-10.0.0_r38android-10.0.0_r37android-10.0.0_r36android-10.0.0_r35android-10.0.0_r34android-10.0.0_r33android-10.0.0_r32android-10.0.0_r31android-10.0.0_r30android-10.0.0_r14android-10.0.0_r13android-10.0.0_r12android10-qpr3-s1-releaseandroid10-qpr3-releaseandroid10-qpr2-s4-releaseandroid10-qpr2-s3-releaseandroid10-qpr2-s2-releaseandroid10-qpr2-s1-releaseandroid10-qpr2-releaseandroid10-qpr1-mainline-releaseandroid10-mainline-media-releaseandroid10-devandroid10-d4-s1-releaseandroid10-d4-releaseandroid10-c2f2-s2-releaseandroid10-c2f2-s1-releaseandroid10-c2f2-release

Test: atest clatd_test, built and installed on aosp_blueline device
  connected to ipv6-only wifi network: ping 8.8.8.8 still works
  and it is via v4-wlan0 clat tun interface

Bug: 65674744
Bug: 131268436
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I8c9e235e9a5bf1a1436e8dc3af8d0aa86f6dc1a5
Merged-In: I8c9e235e9a5bf1a1436e8dc3af8d0aa86f6dc1a5
(cherry picked from commit 716518d9b9ca52182498b1d7ed0f0ed8ab42cbe1)

1 files changed, 3 insertions, 26 deletions

diff --git a/tun.c b/tun.c
index 7ecbf2c..e2f1342 100644
--- a/tun.c
+++ b/tun.c
@@ -21,20 +21,19 @@
 #include <linux/if_tun.h>
 #include <string.h>
 #include <sys/ioctl.h>
-#include <sys/uio.h>
 #include <unistd.h>
 
 #include "common.h"
 
 /* function: tun_open
- * tries to open the tunnel device
+ * tries to open the tunnel device in non-blocking mode
  */
 int tun_open() {
   int fd;
 
-  fd = open("/dev/tun", O_RDWR | O_CLOEXEC);
+  fd = open("/dev/tun", O_RDWR | O_NONBLOCK | O_CLOEXEC);
   if (fd < 0) {
-    fd = open("/dev/net/tun", O_RDWR | O_CLOEXEC);
+    fd = open("/dev/net/tun", O_RDWR | O_NONBLOCK | O_CLOEXEC);
   }
 
   return fd;
@@ -65,25 +64,3 @@ int tun_alloc(char *dev, int fd, size_t len) {
   strlcpy(dev, ifr.ifr_name, len);
   return 0;
 }
-
-/* function: set_nonblocking
- * sets a filedescriptor to non-blocking mode
- * fd - the filedescriptor
- * returns: 0 on success, -1 on failure
- */
-int set_nonblocking(int fd) {
-  int flags = fcntl(fd, F_GETFL);
-  if (flags == -1) {
-    return flags;
-  }
-  return fcntl(fd, F_SETFL, flags | O_NONBLOCK);
-}
-
-/* function: send_tun
- * sends a clat_packet to a tun interface
- * fd      - the tun filedescriptor
- * out     - the packet to send
- * iov_len - the number of entries in the clat_packet
- * returns: number of bytes read on success, -1 on failure
- */
-int send_tun(int fd, clat_packet out, int iov_len) { return writev(fd, out, iov_len); }