diff options
| -rw-r--r-- | mktuntap.8 | 5 | ||||
| -rw-r--r-- | mktuntap.c | 28 |
2 files changed, 23 insertions, 10 deletions
diff --git a/mktuntap.8 b/mktuntap.8 index 7e6414d..6f2a32f 100644 --- a/mktuntap.8 +++ b/mktuntap.8 @@ -23,6 +23,7 @@ .Sh SYNOPSIS .Nm .Fl ( n | p ) +.Op Fl v .Op Fl E .Op Fl i Ar ifr_name .Ar fd @@ -44,6 +45,10 @@ Create a TAP device. Mutually exclusive with .It Fl n Create a TUN device. Mutually exclusive with .Fl p . +.It Fl v +Set the +.Dv IFF_VNET_HDR +flag on the device. .It Fl E Don't set the TUNTAP_NAME environment variable. Caution: if you use this without using diff --git a/mktuntap.c b/mktuntap.c index cae3f5a..8cbc335 100644 --- a/mktuntap.c +++ b/mktuntap.c @@ -61,10 +61,10 @@ void ex_usage() int main(int argc, char **argv) { char *ifr_name_in = NULL; - bool name_env = true, tap = false, tun = false; + bool name_env = true, tap = false, tun = false, vnet_hdr = false; int c; - while ((c = getopt(argc, argv, "+npEi:")) != -1) { + while ((c = getopt(argc, argv, "+npvEi:")) != -1) { switch (c) { case 'n': tun = true; @@ -72,6 +72,9 @@ int main(int argc, char **argv) case 'p': tap = true; break; + case 'v': + vnet_hdr = true; + break; case 'E': name_env = false; break; @@ -113,19 +116,24 @@ int main(int argc, char **argv) } int target_fd = (int)target_fd_l; - int tuntap_fd = tuntap_alloc(ifr_name_, tap ? IFF_TAP : IFF_TUN); + short flags = tap ? IFF_TAP : IFF_TUN; + if (vnet_hdr) + flags |= IFF_VNET_HDR; + int tuntap_fd = tuntap_alloc(ifr_name_, flags); if (tuntap_fd < 0) { fprintf(stderr, "mktuntap: failed to open tuntap device: %s\n", strerror(errno)); return EX_IOERR; } - if (dup2(tuntap_fd, target_fd) == -1) { - fprintf(stderr, "mktuntap: %s\n", strerror(errno)); - return EX_IOERR; - } - if (close(tuntap_fd) == -1) { - fprintf(stderr, "mktuntap: %s\n", strerror(errno)); - return EX_IOERR; + if (tuntap_fd != target_fd) { + if (dup2(tuntap_fd, target_fd) == -1) { + fprintf(stderr, "mktuntap: %s\n", strerror(errno)); + return EX_IOERR; + } + if (close(tuntap_fd) == -1) { + fprintf(stderr, "mktuntap: %s\n", strerror(errno)); + return EX_IOERR; + } } if (name_env) { |