taglinefilesource code
IFF_UP464drivers/net/ppp.cppp->dev->flags &= ~IFF_UP; /* down the device */
IFF_UP650drivers/net/ppp.cif (((struct ppp *) ppp)->dev->flags & IFF_UP)
IFF_UP1021drivers/net/ppp.cif ((ppp->dev->flags & IFF_UP) && ppp_do_ip(ppp, proto, c, count)) {
IFF_UP1693drivers/net/ppp.cif (!(dev->flags & IFF_UP)) {
IFF_UP1910drivers/net/ppp.cif (ppp->dev->flags & IFF_UP)
IFF_UP1923drivers/net/ppp.cif (ppp->dev->flags & IFF_UP)
IFF_UP626drivers/net/slip.cdev->flags|=IFF_UP;
IFF_UP260net/inet/dev.cdev->flags |= (IFF_UP | IFF_RUNNING);
IFF_UP342net/inet/dev.c(dev->slave->flags & IFF_UP))
IFF_UP855net/inet/dev.cif(!(dev->flags & IFF_UP))  /* Downed devices don't count */
IFF_UP1026net/inet/dev.cIFF_UP | IFF_BROADCAST | IFF_DEBUG | IFF_LOOPBACK |
IFF_UP1054net/inet/dev.cif ((old_flags & IFF_UP) && ((dev->flags & IFF_UP) == 0)) 
IFF_UP1064net/inet/dev.cret = (! (old_flags & IFF_UP) && (dev->flags & IFF_UP))
IFF_UP1070net/inet/dev.cdev->flags&=~IFF_UP;  /* Didnt open so down the if */
IFF_UP1270net/inet/dev.cif((slave->flags&(IFF_UP|IFF_RUNNING))!=(IFF_UP|IFF_RUNNING))
IFF_UP143net/inet/devinet.cif (!(dev->flags & IFF_UP))
IFF_UP227net/inet/devinet.cif (!(dev->flags & IFF_UP))
IFF_UP237net/inet/devinet.cif (!(dev->flags & IFF_UP))
IFF_UP1358net/inet/ip.cif (dev2->flags & IFF_UP) 
IFF_UP1781net/inet/ip.cif (dev->flags & IFF_UP) 
IFF_UP1859net/inet/ip.cif (dev->flags & IFF_UP) 
IFF_UP213net/inet/packet.cif (dev->flags & IFF_UP) 
IFF_UP402net/inet/route.cif ((dev2->flags & IFF_UP) && dev2->pa_addr == gw)