cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

ip6t_rt.c (4466B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/* Kernel module to match ROUTING parameters. */
      3
      4/* (C) 2001-2002 Andras Kis-Szabo <kisza@sch.bme.hu>
      5 */
      6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
      7#include <linux/module.h>
      8#include <linux/skbuff.h>
      9#include <linux/ipv6.h>
     10#include <linux/types.h>
     11#include <net/checksum.h>
     12#include <net/ipv6.h>
     13
     14#include <asm/byteorder.h>
     15
     16#include <linux/netfilter/x_tables.h>
     17#include <linux/netfilter_ipv6/ip6_tables.h>
     18#include <linux/netfilter_ipv6/ip6t_rt.h>
     19
     20MODULE_LICENSE("GPL");
     21MODULE_DESCRIPTION("Xtables: IPv6 Routing Header match");
     22MODULE_AUTHOR("Andras Kis-Szabo <kisza@sch.bme.hu>");
     23
     24/* Returns 1 if the id is matched by the range, 0 otherwise */
     25static inline bool
     26segsleft_match(u_int32_t min, u_int32_t max, u_int32_t id, bool invert)
     27{
     28	return (id >= min && id <= max) ^ invert;
     29}
     30
     31static bool rt_mt6(const struct sk_buff *skb, struct xt_action_param *par)
     32{
     33	struct ipv6_rt_hdr _route;
     34	const struct ipv6_rt_hdr *rh;
     35	const struct ip6t_rt *rtinfo = par->matchinfo;
     36	unsigned int temp;
     37	unsigned int ptr = 0;
     38	unsigned int hdrlen = 0;
     39	bool ret = false;
     40	struct in6_addr _addr;
     41	const struct in6_addr *ap;
     42	int err;
     43
     44	err = ipv6_find_hdr(skb, &ptr, NEXTHDR_ROUTING, NULL, NULL);
     45	if (err < 0) {
     46		if (err != -ENOENT)
     47			par->hotdrop = true;
     48		return false;
     49	}
     50
     51	rh = skb_header_pointer(skb, ptr, sizeof(_route), &_route);
     52	if (rh == NULL) {
     53		par->hotdrop = true;
     54		return false;
     55	}
     56
     57	hdrlen = ipv6_optlen(rh);
     58	if (skb->len - ptr < hdrlen) {
     59		/* Pcket smaller than its length field */
     60		return false;
     61	}
     62
     63	ret = (segsleft_match(rtinfo->segsleft[0], rtinfo->segsleft[1],
     64			      rh->segments_left,
     65			      !!(rtinfo->invflags & IP6T_RT_INV_SGS))) &&
     66	      (!(rtinfo->flags & IP6T_RT_LEN) ||
     67	       ((rtinfo->hdrlen == hdrlen) ^
     68		!!(rtinfo->invflags & IP6T_RT_INV_LEN))) &&
     69	      (!(rtinfo->flags & IP6T_RT_TYP) ||
     70	       ((rtinfo->rt_type == rh->type) ^
     71		!!(rtinfo->invflags & IP6T_RT_INV_TYP)));
     72
     73	if (ret && (rtinfo->flags & IP6T_RT_RES)) {
     74		const u_int32_t *rp;
     75		u_int32_t _reserved;
     76		rp = skb_header_pointer(skb,
     77					ptr + offsetof(struct rt0_hdr,
     78						       reserved),
     79					sizeof(_reserved),
     80					&_reserved);
     81		if (!rp) {
     82			par->hotdrop = true;
     83			return false;
     84		}
     85
     86		ret = (*rp == 0);
     87	}
     88
     89	if (!(rtinfo->flags & IP6T_RT_FST)) {
     90		return ret;
     91	} else if (rtinfo->flags & IP6T_RT_FST_NSTRICT) {
     92		if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
     93			return false;
     94		} else {
     95			unsigned int i = 0;
     96
     97			for (temp = 0;
     98			     temp < (unsigned int)((hdrlen - 8) / 16);
     99			     temp++) {
    100				ap = skb_header_pointer(skb,
    101							ptr
    102							+ sizeof(struct rt0_hdr)
    103							+ temp * sizeof(_addr),
    104							sizeof(_addr),
    105							&_addr);
    106
    107				if (ap == NULL) {
    108					par->hotdrop = true;
    109					return false;
    110				}
    111
    112				if (ipv6_addr_equal(ap, &rtinfo->addrs[i]))
    113					i++;
    114				if (i == rtinfo->addrnr)
    115					break;
    116			}
    117			if (i == rtinfo->addrnr)
    118				return ret;
    119			else
    120				return false;
    121		}
    122	} else {
    123		if (rtinfo->addrnr > (unsigned int)((hdrlen - 8) / 16)) {
    124			return false;
    125		} else {
    126			for (temp = 0; temp < rtinfo->addrnr; temp++) {
    127				ap = skb_header_pointer(skb,
    128							ptr
    129							+ sizeof(struct rt0_hdr)
    130							+ temp * sizeof(_addr),
    131							sizeof(_addr),
    132							&_addr);
    133				if (ap == NULL) {
    134					par->hotdrop = true;
    135					return false;
    136				}
    137
    138				if (!ipv6_addr_equal(ap, &rtinfo->addrs[temp]))
    139					break;
    140			}
    141			if (temp == rtinfo->addrnr &&
    142			    temp == (unsigned int)((hdrlen - 8) / 16))
    143				return ret;
    144			else
    145				return false;
    146		}
    147	}
    148
    149	return false;
    150}
    151
    152static int rt_mt6_check(const struct xt_mtchk_param *par)
    153{
    154	const struct ip6t_rt *rtinfo = par->matchinfo;
    155
    156	if (rtinfo->invflags & ~IP6T_RT_INV_MASK) {
    157		pr_debug("unknown flags %X\n", rtinfo->invflags);
    158		return -EINVAL;
    159	}
    160	if ((rtinfo->flags & (IP6T_RT_RES | IP6T_RT_FST_MASK)) &&
    161	    (!(rtinfo->flags & IP6T_RT_TYP) ||
    162	     (rtinfo->rt_type != 0) ||
    163	     (rtinfo->invflags & IP6T_RT_INV_TYP))) {
    164		pr_debug("`--rt-type 0' required before `--rt-0-*'");
    165		return -EINVAL;
    166	}
    167
    168	return 0;
    169}
    170
    171static struct xt_match rt_mt6_reg __read_mostly = {
    172	.name		= "rt",
    173	.family		= NFPROTO_IPV6,
    174	.match		= rt_mt6,
    175	.matchsize	= sizeof(struct ip6t_rt),
    176	.checkentry	= rt_mt6_check,
    177	.me		= THIS_MODULE,
    178};
    179
    180static int __init rt_mt6_init(void)
    181{
    182	return xt_register_match(&rt_mt6_reg);
    183}
    184
    185static void __exit rt_mt6_exit(void)
    186{
    187	xt_unregister_match(&rt_mt6_reg);
    188}
    189
    190module_init(rt_mt6_init);
    191module_exit(rt_mt6_exit);