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5fce1e43e2
This driver calls ether_setup to set up the network device.
The ether_setup function would add the IFF_TX_SKB_SHARING flag to the
device. This flag indicates that it is safe to transmit shared skbs to
the device.
However, this is not true. This driver may pad the frame (in eth_tx)
before transmission, so the skb may be modified.
Fixes: 550fd08c2c ("net: Audit drivers to identify those needing IFF_TX_SKB_SHARING cleared")
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: Xie He <xie.he.0141@gmail.com>
Link: https://lore.kernel.org/r/20201020063420.187497-1-xie.he.0141@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
133 lines
3.0 KiB
C
133 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Generic HDLC support routines for Linux
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* HDLC Ethernet emulation support
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*
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* Copyright (C) 2002-2006 Krzysztof Halasa <khc@pm.waw.pl>
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*/
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#include <linux/errno.h>
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#include <linux/etherdevice.h>
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#include <linux/gfp.h>
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#include <linux/hdlc.h>
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#include <linux/if_arp.h>
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#include <linux/inetdevice.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pkt_sched.h>
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#include <linux/poll.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr);
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static netdev_tx_t eth_tx(struct sk_buff *skb, struct net_device *dev)
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{
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int pad = ETH_ZLEN - skb->len;
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if (pad > 0) { /* Pad the frame with zeros */
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int len = skb->len;
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if (skb_tailroom(skb) < pad)
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if (pskb_expand_head(skb, 0, pad, GFP_ATOMIC)) {
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dev->stats.tx_dropped++;
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dev_kfree_skb(skb);
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return 0;
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}
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skb_put(skb, pad);
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memset(skb->data + len, 0, pad);
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}
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return dev_to_hdlc(dev)->xmit(skb, dev);
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}
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static struct hdlc_proto proto = {
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.type_trans = eth_type_trans,
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.xmit = eth_tx,
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.ioctl = raw_eth_ioctl,
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.module = THIS_MODULE,
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};
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static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
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{
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raw_hdlc_proto __user *raw_s = ifr->ifr_settings.ifs_ifsu.raw_hdlc;
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const size_t size = sizeof(raw_hdlc_proto);
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raw_hdlc_proto new_settings;
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hdlc_device *hdlc = dev_to_hdlc(dev);
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unsigned int old_qlen;
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int result;
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switch (ifr->ifr_settings.type) {
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case IF_GET_PROTO:
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if (dev_to_hdlc(dev)->proto != &proto)
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return -EINVAL;
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ifr->ifr_settings.type = IF_PROTO_HDLC_ETH;
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if (ifr->ifr_settings.size < size) {
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ifr->ifr_settings.size = size; /* data size wanted */
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return -ENOBUFS;
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}
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if (copy_to_user(raw_s, hdlc->state, size))
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return -EFAULT;
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return 0;
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case IF_PROTO_HDLC_ETH:
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if (!capable(CAP_NET_ADMIN))
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return -EPERM;
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if (dev->flags & IFF_UP)
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return -EBUSY;
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if (copy_from_user(&new_settings, raw_s, size))
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return -EFAULT;
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if (new_settings.encoding == ENCODING_DEFAULT)
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new_settings.encoding = ENCODING_NRZ;
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if (new_settings.parity == PARITY_DEFAULT)
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new_settings.parity = PARITY_CRC16_PR1_CCITT;
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result = hdlc->attach(dev, new_settings.encoding,
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new_settings.parity);
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if (result)
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return result;
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result = attach_hdlc_protocol(dev, &proto,
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sizeof(raw_hdlc_proto));
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if (result)
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return result;
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memcpy(hdlc->state, &new_settings, size);
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old_qlen = dev->tx_queue_len;
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ether_setup(dev);
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dev->tx_queue_len = old_qlen;
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dev->priv_flags &= ~IFF_TX_SKB_SHARING;
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eth_hw_addr_random(dev);
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call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE, dev);
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netif_dormant_off(dev);
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return 0;
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}
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return -EINVAL;
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}
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static int __init mod_init(void)
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{
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register_hdlc_protocol(&proto);
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return 0;
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}
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static void __exit mod_exit(void)
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{
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unregister_hdlc_protocol(&proto);
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}
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module_init(mod_init);
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module_exit(mod_exit);
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MODULE_AUTHOR("Krzysztof Halasa <khc@pm.waw.pl>");
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MODULE_DESCRIPTION("Ethernet encapsulation support for generic HDLC");
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MODULE_LICENSE("GPL v2");
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