Commit e5dc0b40 authored by Jason Wang's avatar Jason Wang Committed by Anthony Liguori
Browse files

tap: introduce a helper to get the name of an interface 



This patch introduces a helper tap_get_ifname() to get the device name of tap
device. This is needed when ifname is unspecified in the command line and qemu
were asked to create tap device by itself. In this situation, the name were
allocated by kernel, so if multiqueue is asked, we need to fetch its name after
creating the first queue.

Only linux has this support since it's the only platform that supports
multiqueue tap.

Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
Signed-off-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
parent 16dbaf90

include/net/tap.h

+1 −0
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ void tap_set_offload(NetClientState *nc, int csum, int tso4, int tso6, int ecn, 
void tap_set_vnet_hdr_len(NetClientState *nc, int len);

int tap_enable(NetClientState *nc);

int tap_disable(NetClientState *nc);

int tap_get_ifname(NetClientState *nc, char *ifname);



int tap_get_fd(NetClientState *nc);

net/tap-aix.c

+6 −0
Original line number Diff line number Diff line
@@ -69,3 +69,9 @@ int tap_fd_disable(int fd) 
{

    return -1;

}



int tap_fd_get_ifname(int fd, char *ifname)

{

    return -1;

}

net/tap-bsd.c

+4 −0
Original line number Diff line number Diff line
@@ -156,3 +156,7 @@ int tap_fd_disable(int fd) 
    return -1;

}



int tap_fd_get_ifname(int fd, char *ifname)

{

    return -1;

}

net/tap-haiku.c

+4 −0
Original line number Diff line number Diff line
@@ -70,3 +70,7 @@ int tap_fd_disable(int fd) 
    return -1;

}



int tap_fd_get_ifname(int fd, char *ifname)

{

    return -1;

}

net/tap-linux.c

+13 −0
Original line number Diff line number Diff line
@@ -261,3 +261,16 @@ int tap_fd_disable(int fd) 
    return ret;

}



int tap_fd_get_ifname(int fd, char *ifname)

{

    struct ifreq ifr;



    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {

        error_report("TUNGETIFF ioctl() failed: %s",

                     strerror(errno));

        return -1;

    }



    pstrcpy(ifname, sizeof(ifr.ifr_name), ifr.ifr_name);

    return 0;

}