Include utun device number in utun error messages

For lack of a better API (or knowledge about a better API) we try to
open utun devices on macOS by trying utun0 to utun255 and use the
first one that works. On my Mac I have already 4 devices that
do nothing but are just there and another VPN connection resulting in a
number of error messages. This explicitly  shows in the log that we
tried the devices instead of some unspecific error.

This changes the log from:

Opening utun (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opened utun device utun5

to

Opening utun0 failed (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun1 failed (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun2 failed (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun3 failed (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opening utun4 failed (connect(AF_SYS_CONTROL)): Resource busy (errno=16)
Opened utun device utun5

Signed-off-by: Arne Schwabe <arne@rfc2549.org>
Feature-ACK-by: "Jonathan K. Bullard" <jkbullard@gmail.com>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <20200725235023.22441-1-arne@rfc2549.org>
URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg20590.html
Signed-off-by: Gert Doering <gert@greenie.muc.de>

diff --git a/src/openvpn/tun.c b/src/openvpn/tun.c
index 82d96927c600ba96d4c4f4d7136aed164b725b53..cc7b65cf495ddb84553e0299d043c6a59a0b781a 100644 (file)
--- a/src/openvpn/tun.c
+++ b/src/openvpn/tun.c
@@ -2950,14 +2950,16 @@ utun_open_helper(struct ctl_info ctlInfo, int utunnum)
 
     if (fd < 0)
     {
-        msg(M_INFO | M_ERRNO, "Opening utun (socket(SYSPROTO_CONTROL))");
+        msg(M_INFO | M_ERRNO, "Opening utun%d failed (socket(SYSPROTO_CONTROL))",
+            utunnum);
         return -2;
     }
 
     if (ioctl(fd, CTLIOCGINFO, &ctlInfo) == -1)
     {
         close(fd);
-        msg(M_INFO | M_ERRNO, "Opening utun (ioctl(CTLIOCGINFO))");
+        msg(M_INFO | M_ERRNO, "Opening utun%d failed (ioctl(CTLIOCGINFO))",
+            utunnum);
         return -2;
     }
 
@@ -2975,7 +2977,8 @@ utun_open_helper(struct ctl_info ctlInfo, int utunnum)
 
     if (connect(fd, (struct sockaddr *)&sc, sizeof(sc)) < 0)
     {
-        msg(M_INFO | M_ERRNO, "Opening utun (connect(AF_SYS_CONTROL))");
+        msg(M_INFO | M_ERRNO, "Opening utun%d failed (connect(AF_SYS_CONTROL))",
+            utunnum);
         close(fd);
         return -1;
     }