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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ipcomp.c (4477B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * IP Payload Compression Protocol (IPComp) - RFC3173.
      4 *
      5 * Copyright (c) 2003 James Morris <jmorris@intercode.com.au>
      6 *
      7 * Todo:
      8 *   - Tunable compression parameters.
      9 *   - Compression stats.
     10 *   - Adaptive compression.
     11 */
     12#include <linux/module.h>
     13#include <linux/err.h>
     14#include <linux/rtnetlink.h>
     15#include <net/ip.h>
     16#include <net/xfrm.h>
     17#include <net/icmp.h>
     18#include <net/ipcomp.h>
     19#include <net/protocol.h>
     20#include <net/sock.h>
     21
     22static int ipcomp4_err(struct sk_buff *skb, u32 info)
     23{
     24	struct net *net = dev_net(skb->dev);
     25	__be32 spi;
     26	const struct iphdr *iph = (const struct iphdr *)skb->data;
     27	struct ip_comp_hdr *ipch = (struct ip_comp_hdr *)(skb->data+(iph->ihl<<2));
     28	struct xfrm_state *x;
     29
     30	switch (icmp_hdr(skb)->type) {
     31	case ICMP_DEST_UNREACH:
     32		if (icmp_hdr(skb)->code != ICMP_FRAG_NEEDED)
     33			return 0;
     34		break;
     35	case ICMP_REDIRECT:
     36		break;
     37	default:
     38		return 0;
     39	}
     40
     41	spi = htonl(ntohs(ipch->cpi));
     42	x = xfrm_state_lookup(net, skb->mark, (const xfrm_address_t *)&iph->daddr,
     43			      spi, IPPROTO_COMP, AF_INET);
     44	if (!x)
     45		return 0;
     46
     47	if (icmp_hdr(skb)->type == ICMP_DEST_UNREACH)
     48		ipv4_update_pmtu(skb, net, info, 0, IPPROTO_COMP);
     49	else
     50		ipv4_redirect(skb, net, 0, IPPROTO_COMP);
     51	xfrm_state_put(x);
     52
     53	return 0;
     54}
     55
     56/* We always hold one tunnel user reference to indicate a tunnel */
     57static struct xfrm_state *ipcomp_tunnel_create(struct xfrm_state *x)
     58{
     59	struct net *net = xs_net(x);
     60	struct xfrm_state *t;
     61
     62	t = xfrm_state_alloc(net);
     63	if (!t)
     64		goto out;
     65
     66	t->id.proto = IPPROTO_IPIP;
     67	t->id.spi = x->props.saddr.a4;
     68	t->id.daddr.a4 = x->id.daddr.a4;
     69	memcpy(&t->sel, &x->sel, sizeof(t->sel));
     70	t->props.family = AF_INET;
     71	t->props.mode = x->props.mode;
     72	t->props.saddr.a4 = x->props.saddr.a4;
     73	t->props.flags = x->props.flags;
     74	t->props.extra_flags = x->props.extra_flags;
     75	memcpy(&t->mark, &x->mark, sizeof(t->mark));
     76	t->if_id = x->if_id;
     77
     78	if (xfrm_init_state(t))
     79		goto error;
     80
     81	atomic_set(&t->tunnel_users, 1);
     82out:
     83	return t;
     84
     85error:
     86	t->km.state = XFRM_STATE_DEAD;
     87	xfrm_state_put(t);
     88	t = NULL;
     89	goto out;
     90}
     91
     92/*
     93 * Must be protected by xfrm_cfg_mutex.  State and tunnel user references are
     94 * always incremented on success.
     95 */
     96static int ipcomp_tunnel_attach(struct xfrm_state *x)
     97{
     98	struct net *net = xs_net(x);
     99	int err = 0;
    100	struct xfrm_state *t;
    101	u32 mark = x->mark.v & x->mark.m;
    102
    103	t = xfrm_state_lookup(net, mark, (xfrm_address_t *)&x->id.daddr.a4,
    104			      x->props.saddr.a4, IPPROTO_IPIP, AF_INET);
    105	if (!t) {
    106		t = ipcomp_tunnel_create(x);
    107		if (!t) {
    108			err = -EINVAL;
    109			goto out;
    110		}
    111		xfrm_state_insert(t);
    112		xfrm_state_hold(t);
    113	}
    114	x->tunnel = t;
    115	atomic_inc(&t->tunnel_users);
    116out:
    117	return err;
    118}
    119
    120static int ipcomp4_init_state(struct xfrm_state *x)
    121{
    122	int err = -EINVAL;
    123
    124	x->props.header_len = 0;
    125	switch (x->props.mode) {
    126	case XFRM_MODE_TRANSPORT:
    127		break;
    128	case XFRM_MODE_TUNNEL:
    129		x->props.header_len += sizeof(struct iphdr);
    130		break;
    131	default:
    132		goto out;
    133	}
    134
    135	err = ipcomp_init_state(x);
    136	if (err)
    137		goto out;
    138
    139	if (x->props.mode == XFRM_MODE_TUNNEL) {
    140		err = ipcomp_tunnel_attach(x);
    141		if (err)
    142			goto out;
    143	}
    144
    145	err = 0;
    146out:
    147	return err;
    148}
    149
    150static int ipcomp4_rcv_cb(struct sk_buff *skb, int err)
    151{
    152	return 0;
    153}
    154
    155static const struct xfrm_type ipcomp_type = {
    156	.owner		= THIS_MODULE,
    157	.proto	     	= IPPROTO_COMP,
    158	.init_state	= ipcomp4_init_state,
    159	.destructor	= ipcomp_destroy,
    160	.input		= ipcomp_input,
    161	.output		= ipcomp_output
    162};
    163
    164static struct xfrm4_protocol ipcomp4_protocol = {
    165	.handler	=	xfrm4_rcv,
    166	.input_handler	=	xfrm_input,
    167	.cb_handler	=	ipcomp4_rcv_cb,
    168	.err_handler	=	ipcomp4_err,
    169	.priority	=	0,
    170};
    171
    172static int __init ipcomp4_init(void)
    173{
    174	if (xfrm_register_type(&ipcomp_type, AF_INET) < 0) {
    175		pr_info("%s: can't add xfrm type\n", __func__);
    176		return -EAGAIN;
    177	}
    178	if (xfrm4_protocol_register(&ipcomp4_protocol, IPPROTO_COMP) < 0) {
    179		pr_info("%s: can't add protocol\n", __func__);
    180		xfrm_unregister_type(&ipcomp_type, AF_INET);
    181		return -EAGAIN;
    182	}
    183	return 0;
    184}
    185
    186static void __exit ipcomp4_fini(void)
    187{
    188	if (xfrm4_protocol_deregister(&ipcomp4_protocol, IPPROTO_COMP) < 0)
    189		pr_info("%s: can't remove protocol\n", __func__);
    190	xfrm_unregister_type(&ipcomp_type, AF_INET);
    191}
    192
    193module_init(ipcomp4_init);
    194module_exit(ipcomp4_fini);
    195
    196MODULE_LICENSE("GPL");
    197MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp/IPv4) - RFC3173");
    198MODULE_AUTHOR("James Morris <jmorris@intercode.com.au>");
    199
    200MODULE_ALIAS_XFRM_TYPE(AF_INET, XFRM_PROTO_COMP);