all: integrate with mac80211_hwsim

Two virtual wireless devices are instantiated during network devices
initialization.

A new flag (-wifi) is added that controls whether these virtual wifi
devices are instantiated and configured during proc initialization.

Also, two new pseudo syscalls are added:
1. syz_80211_inject_frame(mac_addr, packet, packet_len) -- injects an
arbitrary packet into the wireless stack. It is injected as if it
originated from the device identitied by mac_addr.
2. syz_80211_join_ibss(interface_name, ssid, ssid_len, mode) --
puts a specific network interface into IBSS state and joins an IBSS
network.

Arguments of syz_80211_join_ibss:
1) interface_name -- null-terminated string that identifies
a wireless interface
2) ssid, ssid_len -- SSID of an IBSS network to join to
3) mode -- mode of syz_80211_join_ibss operation (see below)

Modes of operation:
JOIN_IBSS_NO_SCAN (0x0) -- channel scan is not performed and
syz_80211_join_ibss waits until the interface reaches IF_OPER_UP.
JOIN_IBSS_BG_SCAN (0x1) -- channel scan is performed (takes ~ 9
seconds), syz_80211_join_ibss does not await IF_OPER_UP.
JOIN_IBSS_BG_NO_SCAN (0x2) -- channel scan is not performed,
syz_80211_join_ibss does not await IF_OPER_UP.

Local testing ensured that these syscalls are indeed able to set up an
operating network and inject packets into mac80211.

1 files changed, 8 insertions, 0 deletions

diff --git a/pkg/host/features_linux.go b/pkg/host/features_linux.go
index 230022c38..5a91fc8ea 100644
--- a/pkg/host/features_linux.go
+++ b/pkg/host/features_linux.go
@@ -29,6 +29,7 @@ func init() {
 	checkFeature[FeatureDevlinkPCI] = checkDevlinkPCI
 	checkFeature[FeatureUSBEmulation] = checkUSBEmulation
 	checkFeature[FeatureVhciInjection] = checkVhciInjection
+	checkFeature[FeatureWifiEmulation] = checkWifiEmulation
 }
 
 func checkCoverage() string {
@@ -219,3 +220,10 @@ func checkDevlinkPCI() string {
 	}
 	return ""
 }
+
+func checkWifiEmulation() string {
+	if err := osutil.IsAccessible("/sys/class/mac80211_hwsim/"); err != nil {
+		return err.Error()
+	}
+	return ""
+}