--- /dev/null
+/*
+ * RTL8188EU monitor interface
+ *
+ * Copyright (C) 2015 Jakub Sitnicki
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ */
+
+/*
+ * Monitor interface receives all transmitted and received IEEE 802.11
+ * frames, both Data and Management, and passes them up to userspace
+ * preserving the WLAN headers.
+ */
+
+#ifndef _MON_H_
+#define _MON_H_
+
+struct net_device;
+struct recv_frame;
+struct xmit_frame;
+
+struct net_device *rtl88eu_mon_init(void);
+void rtl88eu_mon_deinit(struct net_device *dev);
+
+void rtl88eu_mon_recv_hook(struct net_device *dev, struct recv_frame *frame);
+void rtl88eu_mon_xmit_hook(struct net_device *dev, struct xmit_frame *frame,
+ uint frag_len);
+
+#endif /* _MON_H_ */
--- /dev/null
+/*
+ * RTL8188EU monitor interface
+ *
+ * Copyright (C) 2015 Jakub Sitnicki
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License version 2 as published by the
+ * Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ */
+
+#include <linux/ieee80211.h>
+#include <linux/netdevice.h>
+#include <net/cfg80211.h>
+
+#include <drv_types.h>
+#include <rtw_recv.h>
+#include <rtw_xmit.h>
+
+/**
+ * unprotect_frame() - unset Protected flag and strip off IV and ICV/MIC
+ */
+static void unprotect_frame(struct sk_buff *skb, int iv_len, int icv_len)
+{
+ struct ieee80211_hdr *hdr;
+ int hdr_len;
+
+ hdr = (struct ieee80211_hdr *)skb->data;
+ hdr_len = ieee80211_hdrlen(hdr->frame_control);
+
+ if (skb->len < hdr_len + iv_len + icv_len)
+ return;
+ if (!ieee80211_has_protected(hdr->frame_control))
+ return;
+
+ hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+
+ memmove(skb->data + iv_len, skb->data, hdr_len);
+ skb_pull(skb, iv_len);
+ skb_trim(skb, skb->len - icv_len);
+}
+
+static void mon_recv_decrypted(struct net_device *dev, const u8 *data,
+ int data_len, int iv_len, int icv_len)
+{
+ struct sk_buff *skb;
+
+ skb = netdev_alloc_skb(dev, data_len);
+ if (!skb)
+ return;
+ memcpy(skb_put(skb, data_len), data, data_len);
+
+ /*
+ * Frame data is not encrypted. Strip off protection so
+ * userspace doesn't think that it is.
+ */
+ unprotect_frame(skb, iv_len, icv_len);
+
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ skb->protocol = eth_type_trans(skb, dev);
+ netif_rx(skb);
+}
+
+static void mon_recv_encrypted(struct net_device *dev, const u8 *data,
+ int data_len)
+{
+ if (net_ratelimit())
+ netdev_info(dev, "Encrypted packets are not supported");
+}
+
+/**
+ * rtl88eu_mon_recv_hook() - forward received frame to the monitor interface
+ *
+ * Assumes that the frame contains an IV and an ICV/MIC, and that
+ * encrypt field in frame->attrib have been set accordingly.
+ */
+void rtl88eu_mon_recv_hook(struct net_device *dev, struct recv_frame *frame)
+{
+ struct rx_pkt_attrib *attr;
+ int iv_len, icv_len;
+ int data_len;
+ u8 *data;
+
+ if (!dev || !frame)
+ return;
+ if (!netif_running(dev))
+ return;
+
+ attr = &frame->attrib;
+ data = frame->rx_data;
+ data_len = frame->len;
+
+ /* Broadcast and multicast frames don't have attr->{iv,icv}_len set */
+ SET_ICE_IV_LEN(iv_len, icv_len, attr->encrypt);
+
+ if (attr->bdecrypted)
+ mon_recv_decrypted(dev, data, data_len, iv_len, icv_len);
+ else
+ mon_recv_encrypted(dev, data, data_len);
+}
+
+/**
+ * rtl88eu_mon_xmit_hook() - forward trasmitted frame to the monitor interface
+ *
+ * Assumes that:
+ * - frame header contains an IV and frame->attrib.iv_len is set accordingly,
+ * - data is not encrypted and ICV/MIC has not been appended yet.
+ */
+void rtl88eu_mon_xmit_hook(struct net_device *dev, struct xmit_frame *frame,
+ uint frag_len)
+{
+ struct pkt_attrib *attr;
+ u8 *data;
+ int i, offset;
+
+ if (!dev || !frame)
+ return;
+ if (!netif_running(dev))
+ return;
+
+ attr = &frame->attrib;
+
+ offset = TXDESC_SIZE + frame->pkt_offset * PACKET_OFFSET_SZ;
+ data = frame->buf_addr + offset;
+
+ for (i = 0; i < attr->nr_frags - 1; i++) {
+ mon_recv_decrypted(dev, data, frag_len, attr->iv_len, 0);
+ data += frag_len;
+ data = (u8 *)round_up((size_t)data, 4);
+ }
+ /* Last fragment has different length */
+ mon_recv_decrypted(dev, data, attr->last_txcmdsz, attr->iv_len, 0);
+}
+
+static netdev_tx_t mon_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+}
+
+static const struct net_device_ops mon_netdev_ops = {
+ .ndo_start_xmit = mon_xmit,
+ .ndo_change_mtu = eth_change_mtu,
+ .ndo_set_mac_address = eth_mac_addr,
+ .ndo_validate_addr = eth_validate_addr,
+};
+
+static void mon_setup(struct net_device *dev)
+{
+ dev->netdev_ops = &mon_netdev_ops;
+ dev->destructor = free_netdev;
+ ether_setup(dev);
+ dev->tx_queue_len = 0;
+ dev->type = ARPHRD_IEEE80211;
+ /*
+ * Use a locally administered address (IEEE 802)
+ * XXX: Copied from mac80211_hwsim driver. Revisit.
+ */
+ eth_zero_addr(dev->dev_addr);
+ dev->dev_addr[0] = 0x12;
+}
+
+struct net_device *rtl88eu_mon_init(void)
+{
+ struct net_device *dev;
+ int err;
+
+ dev = alloc_netdev(0, "mon%d", NET_NAME_UNKNOWN, mon_setup);
+ if (!dev)
+ goto fail;
+
+ err = register_netdev(dev);
+ if (err < 0)
+ goto fail_free_dev;
+
+ return dev;
+
+fail_free_dev:
+ free_netdev(dev);
+fail:
+ return NULL;
+}
+
+void rtl88eu_mon_deinit(struct net_device *dev)
+{
+ if (!dev)
+ return;
+
+ unregister_netdev(dev);
+}