https://github.com/torvalds/linux
Tip revision: 8834f5600cf3c8db365e18a3d5cac2c2780c81e5 authored by Linus Torvalds on 03 February 2019, 21:48:04 UTC
Linux 5.0-rc5
Linux 5.0-rc5
Tip revision: 8834f56
mon.c
// SPDX-License-Identifier: GPL-2.0
/*
* RTL8188EU monitor interface
*
* Copyright (C) 2015 Jakub Sitnicki
*/
#include <linux/ieee80211.h>
#include <linux/netdevice.h>
#include <net/cfg80211.h>
#include <drv_types.h>
#include <rtw_recv.h>
#include <rtw_xmit.h>
#include <mon.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;
skb_put_data(skb, 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->pkt->data;
data_len = frame->pkt->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_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->needs_free_netdev = true;
ether_setup(dev);
dev->priv_flags |= IFF_NO_QUEUE;
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);
}