cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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nsh.c (3292B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Network Service Header
      4 *
      5 * Copyright (c) 2017 Red Hat, Inc. -- Jiri Benc <jbenc@redhat.com>
      6 */
      7
      8#include <linux/module.h>
      9#include <linux/netdevice.h>
     10#include <linux/skbuff.h>
     11#include <net/nsh.h>
     12#include <net/tun_proto.h>
     13
     14int nsh_push(struct sk_buff *skb, const struct nshhdr *pushed_nh)
     15{
     16	struct nshhdr *nh;
     17	size_t length = nsh_hdr_len(pushed_nh);
     18	u8 next_proto;
     19
     20	if (skb->mac_len) {
     21		next_proto = TUN_P_ETHERNET;
     22	} else {
     23		next_proto = tun_p_from_eth_p(skb->protocol);
     24		if (!next_proto)
     25			return -EAFNOSUPPORT;
     26	}
     27
     28	/* Add the NSH header */
     29	if (skb_cow_head(skb, length) < 0)
     30		return -ENOMEM;
     31
     32	skb_push(skb, length);
     33	nh = (struct nshhdr *)(skb->data);
     34	memcpy(nh, pushed_nh, length);
     35	nh->np = next_proto;
     36	skb_postpush_rcsum(skb, nh, length);
     37
     38	skb->protocol = htons(ETH_P_NSH);
     39	skb_reset_mac_header(skb);
     40	skb_reset_network_header(skb);
     41	skb_reset_mac_len(skb);
     42
     43	return 0;
     44}
     45EXPORT_SYMBOL_GPL(nsh_push);
     46
     47int nsh_pop(struct sk_buff *skb)
     48{
     49	struct nshhdr *nh;
     50	size_t length;
     51	__be16 inner_proto;
     52
     53	if (!pskb_may_pull(skb, NSH_BASE_HDR_LEN))
     54		return -ENOMEM;
     55	nh = (struct nshhdr *)(skb->data);
     56	length = nsh_hdr_len(nh);
     57	if (length < NSH_BASE_HDR_LEN)
     58		return -EINVAL;
     59	inner_proto = tun_p_to_eth_p(nh->np);
     60	if (!pskb_may_pull(skb, length))
     61		return -ENOMEM;
     62
     63	if (!inner_proto)
     64		return -EAFNOSUPPORT;
     65
     66	skb_pull_rcsum(skb, length);
     67	skb_reset_mac_header(skb);
     68	skb_reset_network_header(skb);
     69	skb_reset_mac_len(skb);
     70	skb->protocol = inner_proto;
     71
     72	return 0;
     73}
     74EXPORT_SYMBOL_GPL(nsh_pop);
     75
     76static struct sk_buff *nsh_gso_segment(struct sk_buff *skb,
     77				       netdev_features_t features)
     78{
     79	struct sk_buff *segs = ERR_PTR(-EINVAL);
     80	unsigned int nsh_len, mac_len;
     81	__be16 proto;
     82	int nhoff;
     83
     84	skb_reset_network_header(skb);
     85
     86	nhoff = skb->network_header - skb->mac_header;
     87	mac_len = skb->mac_len;
     88
     89	if (unlikely(!pskb_may_pull(skb, NSH_BASE_HDR_LEN)))
     90		goto out;
     91	nsh_len = nsh_hdr_len(nsh_hdr(skb));
     92	if (nsh_len < NSH_BASE_HDR_LEN)
     93		goto out;
     94	if (unlikely(!pskb_may_pull(skb, nsh_len)))
     95		goto out;
     96
     97	proto = tun_p_to_eth_p(nsh_hdr(skb)->np);
     98	if (!proto)
     99		goto out;
    100
    101	__skb_pull(skb, nsh_len);
    102
    103	skb_reset_mac_header(skb);
    104	skb->mac_len = proto == htons(ETH_P_TEB) ? ETH_HLEN : 0;
    105	skb->protocol = proto;
    106
    107	features &= NETIF_F_SG;
    108	segs = skb_mac_gso_segment(skb, features);
    109	if (IS_ERR_OR_NULL(segs)) {
    110		skb_gso_error_unwind(skb, htons(ETH_P_NSH), nsh_len,
    111				     skb->network_header - nhoff,
    112				     mac_len);
    113		goto out;
    114	}
    115
    116	for (skb = segs; skb; skb = skb->next) {
    117		skb->protocol = htons(ETH_P_NSH);
    118		__skb_push(skb, nsh_len);
    119		skb_set_mac_header(skb, -nhoff);
    120		skb->network_header = skb->mac_header + mac_len;
    121		skb->mac_len = mac_len;
    122	}
    123
    124out:
    125	return segs;
    126}
    127
    128static struct packet_offload nsh_packet_offload __read_mostly = {
    129	.type = htons(ETH_P_NSH),
    130	.priority = 15,
    131	.callbacks = {
    132		.gso_segment = nsh_gso_segment,
    133	},
    134};
    135
    136static int __init nsh_init_module(void)
    137{
    138	dev_add_offload(&nsh_packet_offload);
    139	return 0;
    140}
    141
    142static void __exit nsh_cleanup_module(void)
    143{
    144	dev_remove_offload(&nsh_packet_offload);
    145}
    146
    147module_init(nsh_init_module);
    148module_exit(nsh_cleanup_module);
    149
    150MODULE_AUTHOR("Jiri Benc <jbenc@redhat.com>");
    151MODULE_DESCRIPTION("NSH protocol");
    152MODULE_LICENSE("GPL v2");