在Linux上使用ioctl进行被动wifi扫描

Question

I can perform normal scan using ioctl SIOCSIWSCAN and SIOCGIWSCAN and get list of AP, but when I set card into monitor mode i get errno = Operation not supported.

Is there a different ioctl call for passive scans??

I know the wifi card is not the issue, because I get results with airodump-ng and I checked two different cards.

Answer 1

First, on the command line type:

iw phy <phy> info 

and see if new_interface is listed under supported commands. You can get the phy for your cards by:

iw dev

Second, I have found that it's easier to set a card in monitor mode if I delete all interfaces on the phy first. Some cards don't play well if there are interfaces active.

Use ioctl to bring cards up or down and to get the card's hw addr. Otherwise you should be using netlink - You're looking for NL80211_CMD_NEW_INTERFACE in nl80211.h