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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act_connmark.c (6705B)


      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * net/sched/act_connmark.c  netfilter connmark retriever action
      4 * skb mark is over-written
      5 *
      6 * Copyright (c) 2011 Felix Fietkau <nbd@openwrt.org>
      7*/
      8
      9#include <linux/module.h>
     10#include <linux/init.h>
     11#include <linux/kernel.h>
     12#include <linux/skbuff.h>
     13#include <linux/rtnetlink.h>
     14#include <linux/pkt_cls.h>
     15#include <linux/ip.h>
     16#include <linux/ipv6.h>
     17#include <net/netlink.h>
     18#include <net/pkt_sched.h>
     19#include <net/act_api.h>
     20#include <net/pkt_cls.h>
     21#include <uapi/linux/tc_act/tc_connmark.h>
     22#include <net/tc_act/tc_connmark.h>
     23
     24#include <net/netfilter/nf_conntrack.h>
     25#include <net/netfilter/nf_conntrack_core.h>
     26#include <net/netfilter/nf_conntrack_zones.h>
     27
     28static unsigned int connmark_net_id;
     29static struct tc_action_ops act_connmark_ops;
     30
     31static int tcf_connmark_act(struct sk_buff *skb, const struct tc_action *a,
     32			    struct tcf_result *res)
     33{
     34	const struct nf_conntrack_tuple_hash *thash;
     35	struct nf_conntrack_tuple tuple;
     36	enum ip_conntrack_info ctinfo;
     37	struct tcf_connmark_info *ca = to_connmark(a);
     38	struct nf_conntrack_zone zone;
     39	struct nf_conn *c;
     40	int proto;
     41
     42	spin_lock(&ca->tcf_lock);
     43	tcf_lastuse_update(&ca->tcf_tm);
     44	bstats_update(&ca->tcf_bstats, skb);
     45
     46	switch (skb_protocol(skb, true)) {
     47	case htons(ETH_P_IP):
     48		if (skb->len < sizeof(struct iphdr))
     49			goto out;
     50
     51		proto = NFPROTO_IPV4;
     52		break;
     53	case htons(ETH_P_IPV6):
     54		if (skb->len < sizeof(struct ipv6hdr))
     55			goto out;
     56
     57		proto = NFPROTO_IPV6;
     58		break;
     59	default:
     60		goto out;
     61	}
     62
     63	c = nf_ct_get(skb, &ctinfo);
     64	if (c) {
     65		skb->mark = c->mark;
     66		/* using overlimits stats to count how many packets marked */
     67		ca->tcf_qstats.overlimits++;
     68		goto out;
     69	}
     70
     71	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
     72			       proto, ca->net, &tuple))
     73		goto out;
     74
     75	zone.id = ca->zone;
     76	zone.dir = NF_CT_DEFAULT_ZONE_DIR;
     77
     78	thash = nf_conntrack_find_get(ca->net, &zone, &tuple);
     79	if (!thash)
     80		goto out;
     81
     82	c = nf_ct_tuplehash_to_ctrack(thash);
     83	/* using overlimits stats to count how many packets marked */
     84	ca->tcf_qstats.overlimits++;
     85	skb->mark = c->mark;
     86	nf_ct_put(c);
     87
     88out:
     89	spin_unlock(&ca->tcf_lock);
     90	return ca->tcf_action;
     91}
     92
     93static const struct nla_policy connmark_policy[TCA_CONNMARK_MAX + 1] = {
     94	[TCA_CONNMARK_PARMS] = { .len = sizeof(struct tc_connmark) },
     95};
     96
     97static int tcf_connmark_init(struct net *net, struct nlattr *nla,
     98			     struct nlattr *est, struct tc_action **a,
     99			     struct tcf_proto *tp, u32 flags,
    100			     struct netlink_ext_ack *extack)
    101{
    102	struct tc_action_net *tn = net_generic(net, connmark_net_id);
    103	struct nlattr *tb[TCA_CONNMARK_MAX + 1];
    104	bool bind = flags & TCA_ACT_FLAGS_BIND;
    105	struct tcf_chain *goto_ch = NULL;
    106	struct tcf_connmark_info *ci;
    107	struct tc_connmark *parm;
    108	int ret = 0, err;
    109	u32 index;
    110
    111	if (!nla)
    112		return -EINVAL;
    113
    114	ret = nla_parse_nested_deprecated(tb, TCA_CONNMARK_MAX, nla,
    115					  connmark_policy, NULL);
    116	if (ret < 0)
    117		return ret;
    118
    119	if (!tb[TCA_CONNMARK_PARMS])
    120		return -EINVAL;
    121
    122	parm = nla_data(tb[TCA_CONNMARK_PARMS]);
    123	index = parm->index;
    124	ret = tcf_idr_check_alloc(tn, &index, a, bind);
    125	if (!ret) {
    126		ret = tcf_idr_create(tn, index, est, a,
    127				     &act_connmark_ops, bind, false, flags);
    128		if (ret) {
    129			tcf_idr_cleanup(tn, index);
    130			return ret;
    131		}
    132
    133		ci = to_connmark(*a);
    134		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
    135					       extack);
    136		if (err < 0)
    137			goto release_idr;
    138		tcf_action_set_ctrlact(*a, parm->action, goto_ch);
    139		ci->net = net;
    140		ci->zone = parm->zone;
    141
    142		ret = ACT_P_CREATED;
    143	} else if (ret > 0) {
    144		ci = to_connmark(*a);
    145		if (bind)
    146			return 0;
    147		if (!(flags & TCA_ACT_FLAGS_REPLACE)) {
    148			tcf_idr_release(*a, bind);
    149			return -EEXIST;
    150		}
    151		err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch,
    152					       extack);
    153		if (err < 0)
    154			goto release_idr;
    155		/* replacing action and zone */
    156		spin_lock_bh(&ci->tcf_lock);
    157		goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
    158		ci->zone = parm->zone;
    159		spin_unlock_bh(&ci->tcf_lock);
    160		if (goto_ch)
    161			tcf_chain_put_by_act(goto_ch);
    162		ret = 0;
    163	}
    164
    165	return ret;
    166release_idr:
    167	tcf_idr_release(*a, bind);
    168	return err;
    169}
    170
    171static inline int tcf_connmark_dump(struct sk_buff *skb, struct tc_action *a,
    172				    int bind, int ref)
    173{
    174	unsigned char *b = skb_tail_pointer(skb);
    175	struct tcf_connmark_info *ci = to_connmark(a);
    176	struct tc_connmark opt = {
    177		.index   = ci->tcf_index,
    178		.refcnt  = refcount_read(&ci->tcf_refcnt) - ref,
    179		.bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
    180	};
    181	struct tcf_t t;
    182
    183	spin_lock_bh(&ci->tcf_lock);
    184	opt.action = ci->tcf_action;
    185	opt.zone = ci->zone;
    186	if (nla_put(skb, TCA_CONNMARK_PARMS, sizeof(opt), &opt))
    187		goto nla_put_failure;
    188
    189	tcf_tm_dump(&t, &ci->tcf_tm);
    190	if (nla_put_64bit(skb, TCA_CONNMARK_TM, sizeof(t), &t,
    191			  TCA_CONNMARK_PAD))
    192		goto nla_put_failure;
    193	spin_unlock_bh(&ci->tcf_lock);
    194
    195	return skb->len;
    196
    197nla_put_failure:
    198	spin_unlock_bh(&ci->tcf_lock);
    199	nlmsg_trim(skb, b);
    200	return -1;
    201}
    202
    203static int tcf_connmark_walker(struct net *net, struct sk_buff *skb,
    204			       struct netlink_callback *cb, int type,
    205			       const struct tc_action_ops *ops,
    206			       struct netlink_ext_ack *extack)
    207{
    208	struct tc_action_net *tn = net_generic(net, connmark_net_id);
    209
    210	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
    211}
    212
    213static int tcf_connmark_search(struct net *net, struct tc_action **a, u32 index)
    214{
    215	struct tc_action_net *tn = net_generic(net, connmark_net_id);
    216
    217	return tcf_idr_search(tn, a, index);
    218}
    219
    220static struct tc_action_ops act_connmark_ops = {
    221	.kind		=	"connmark",
    222	.id		=	TCA_ID_CONNMARK,
    223	.owner		=	THIS_MODULE,
    224	.act		=	tcf_connmark_act,
    225	.dump		=	tcf_connmark_dump,
    226	.init		=	tcf_connmark_init,
    227	.walk		=	tcf_connmark_walker,
    228	.lookup		=	tcf_connmark_search,
    229	.size		=	sizeof(struct tcf_connmark_info),
    230};
    231
    232static __net_init int connmark_init_net(struct net *net)
    233{
    234	struct tc_action_net *tn = net_generic(net, connmark_net_id);
    235
    236	return tc_action_net_init(net, tn, &act_connmark_ops);
    237}
    238
    239static void __net_exit connmark_exit_net(struct list_head *net_list)
    240{
    241	tc_action_net_exit(net_list, connmark_net_id);
    242}
    243
    244static struct pernet_operations connmark_net_ops = {
    245	.init = connmark_init_net,
    246	.exit_batch = connmark_exit_net,
    247	.id   = &connmark_net_id,
    248	.size = sizeof(struct tc_action_net),
    249};
    250
    251static int __init connmark_init_module(void)
    252{
    253	return tcf_register_action(&act_connmark_ops, &connmark_net_ops);
    254}
    255
    256static void __exit connmark_cleanup_module(void)
    257{
    258	tcf_unregister_action(&act_connmark_ops, &connmark_net_ops);
    259}
    260
    261module_init(connmark_init_module);
    262module_exit(connmark_cleanup_module);
    263MODULE_AUTHOR("Felix Fietkau <nbd@openwrt.org>");
    264MODULE_DESCRIPTION("Connection tracking mark restoring");
    265MODULE_LICENSE("GPL");