--- /dev/null
+// SPDX-License-Identifier: GPL-2.0+
+/* net/sched/act_ctinfo.c netfilter ctinfo connmark actions
+ *
+ * Copyright (c) 2019 Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/pkt_cls.h>
+#include <linux/ip.h>
+#include <linux/ipv6.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/act_api.h>
+#include <net/pkt_cls.h>
+#include <uapi/linux/tc_act/tc_ctinfo.h>
+#include <net/tc_act/tc_ctinfo.h>
+
+#include <net/netfilter/nf_conntrack.h>
+#include <net/netfilter/nf_conntrack_core.h>
+#include <net/netfilter/nf_conntrack_ecache.h>
+#include <net/netfilter/nf_conntrack_zones.h>
+
+static struct tc_action_ops act_ctinfo_ops;
+static unsigned int ctinfo_net_id;
+
+static void tcf_ctinfo_dscp_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
+ struct tcf_ctinfo_params *cp,
+ struct sk_buff *skb, int wlen, int proto)
+{
+ u8 dscp, newdscp;
+
+ newdscp = (((ct->mark & cp->dscpmask) >> cp->dscpmaskshift) << 2) &
+ ~INET_ECN_MASK;
+
+ switch (proto) {
+ case NFPROTO_IPV4:
+ dscp = ipv4_get_dsfield(ip_hdr(skb)) & ~INET_ECN_MASK;
+ if (dscp != newdscp) {
+ if (likely(!skb_try_make_writable(skb, wlen))) {
+ ipv4_change_dsfield(ip_hdr(skb),
+ INET_ECN_MASK,
+ newdscp);
+ ca->stats_dscp_set++;
+ } else {
+ ca->stats_dscp_error++;
+ }
+ }
+ break;
+ case NFPROTO_IPV6:
+ dscp = ipv6_get_dsfield(ipv6_hdr(skb)) & ~INET_ECN_MASK;
+ if (dscp != newdscp) {
+ if (likely(!skb_try_make_writable(skb, wlen))) {
+ ipv6_change_dsfield(ipv6_hdr(skb),
+ INET_ECN_MASK,
+ newdscp);
+ ca->stats_dscp_set++;
+ } else {
+ ca->stats_dscp_error++;
+ }
+ }
+ break;
+ default:
+ break;
+ }
+}
+
+static void tcf_ctinfo_cpmark_set(struct nf_conn *ct, struct tcf_ctinfo *ca,
+ struct tcf_ctinfo_params *cp,
+ struct sk_buff *skb)
+{
+ ca->stats_cpmark_set++;
+ skb->mark = ct->mark & cp->cpmarkmask;
+}
+
+static int tcf_ctinfo_act(struct sk_buff *skb, const struct tc_action *a,
+ struct tcf_result *res)
+{
+ const struct nf_conntrack_tuple_hash *thash = NULL;
+ struct tcf_ctinfo *ca = to_ctinfo(a);
+ struct nf_conntrack_tuple tuple;
+ struct nf_conntrack_zone zone;
+ enum ip_conntrack_info ctinfo;
+ struct tcf_ctinfo_params *cp;
+ struct nf_conn *ct;
+ int proto, wlen;
+ int action;
+
+ cp = rcu_dereference_bh(ca->params);
+
+ tcf_lastuse_update(&ca->tcf_tm);
+ bstats_update(&ca->tcf_bstats, skb);
+ action = READ_ONCE(ca->tcf_action);
+
+ wlen = skb_network_offset(skb);
+ if (tc_skb_protocol(skb) == htons(ETH_P_IP)) {
+ wlen += sizeof(struct iphdr);
+ if (!pskb_may_pull(skb, wlen))
+ goto out;
+
+ proto = NFPROTO_IPV4;
+ } else if (tc_skb_protocol(skb) == htons(ETH_P_IPV6)) {
+ wlen += sizeof(struct ipv6hdr);
+ if (!pskb_may_pull(skb, wlen))
+ goto out;
+
+ proto = NFPROTO_IPV6;
+ } else {
+ goto out;
+ }
+
+ ct = nf_ct_get(skb, &ctinfo);
+ if (!ct) { /* look harder, usually ingress */
+ if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb),
+ proto, cp->net, &tuple))
+ goto out;
+ zone.id = cp->zone;
+ zone.dir = NF_CT_DEFAULT_ZONE_DIR;
+
+ thash = nf_conntrack_find_get(cp->net, &zone, &tuple);
+ if (!thash)
+ goto out;
+
+ ct = nf_ct_tuplehash_to_ctrack(thash);
+ }
+
+ if (cp->mode & CTINFO_MODE_DSCP)
+ if (!cp->dscpstatemask || (ct->mark & cp->dscpstatemask))
+ tcf_ctinfo_dscp_set(ct, ca, cp, skb, wlen, proto);
+
+ if (cp->mode & CTINFO_MODE_CPMARK)
+ tcf_ctinfo_cpmark_set(ct, ca, cp, skb);
+
+ if (thash)
+ nf_ct_put(ct);
+out:
+ return action;
+}
+
+static const struct nla_policy ctinfo_policy[TCA_CTINFO_MAX + 1] = {
+ [TCA_CTINFO_ACT] = { .len = sizeof(struct
+ tc_ctinfo) },
+ [TCA_CTINFO_ZONE] = { .type = NLA_U16 },
+ [TCA_CTINFO_PARMS_DSCP_MASK] = { .type = NLA_U32 },
+ [TCA_CTINFO_PARMS_DSCP_STATEMASK] = { .type = NLA_U32 },
+ [TCA_CTINFO_PARMS_CPMARK_MASK] = { .type = NLA_U32 },
+};
+
+static int tcf_ctinfo_init(struct net *net, struct nlattr *nla,
+ struct nlattr *est, struct tc_action **a,
+ int ovr, int bind, bool rtnl_held,
+ struct tcf_proto *tp,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
+ struct nlattr *tb[TCA_CTINFO_MAX + 1];
+ struct tcf_ctinfo_params *cp_new;
+ struct tcf_chain *goto_ch = NULL;
+ u32 dscpmask = 0, dscpstatemask;
+ struct tc_ctinfo *actparm;
+ struct tcf_ctinfo *ci;
+ u8 dscpmaskshift;
+ int ret = 0, err;
+
+ if (!nla)
+ return -EINVAL;
+
+ err = nla_parse_nested(tb, TCA_CTINFO_MAX, nla, ctinfo_policy, NULL);
+ if (err < 0)
+ return err;
+
+ if (!tb[TCA_CTINFO_ACT])
+ return -EINVAL;
+ actparm = nla_data(tb[TCA_CTINFO_ACT]);
+
+ /* do some basic validation here before dynamically allocating things */
+ /* that we would otherwise have to clean up. */
+ if (tb[TCA_CTINFO_PARMS_DSCP_MASK]) {
+ dscpmask = nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_MASK]);
+ /* need contiguous 6 bit mask */
+ dscpmaskshift = dscpmask ? __ffs(dscpmask) : 0;
+ if ((~0 & (dscpmask >> dscpmaskshift)) != 0x3f)
+ return -EINVAL;
+ dscpstatemask = tb[TCA_CTINFO_PARMS_DSCP_STATEMASK] ?
+ nla_get_u32(tb[TCA_CTINFO_PARMS_DSCP_STATEMASK]) : 0;
+ /* mask & statemask must not overlap */
+ if (dscpmask & dscpstatemask)
+ return -EINVAL;
+ }
+
+ /* done the validation:now to the actual action allocation */
+ err = tcf_idr_check_alloc(tn, &actparm->index, a, bind);
+ if (!err) {
+ ret = tcf_idr_create(tn, actparm->index, est, a,
+ &act_ctinfo_ops, bind, false);
+ if (ret) {
+ tcf_idr_cleanup(tn, actparm->index);
+ return ret;
+ }
+ } else if (err > 0) {
+ if (bind) /* don't override defaults */
+ return 0;
+ if (!ovr) {
+ tcf_idr_release(*a, bind);
+ return -EEXIST;
+ }
+ } else {
+ return err;
+ }
+
+ err = tcf_action_check_ctrlact(actparm->action, tp, &goto_ch, extack);
+ if (err < 0)
+ goto release_idr;
+
+ ci = to_ctinfo(*a);
+
+ cp_new = kzalloc(sizeof(*cp_new), GFP_KERNEL);
+ if (unlikely(!cp_new)) {
+ err = -ENOMEM;
+ goto put_chain;
+ }
+
+ cp_new->net = net;
+ cp_new->zone = tb[TCA_CTINFO_ZONE] ?
+ nla_get_u16(tb[TCA_CTINFO_ZONE]) : 0;
+ if (dscpmask) {
+ cp_new->dscpmask = dscpmask;
+ cp_new->dscpmaskshift = dscpmaskshift;
+ cp_new->dscpstatemask = dscpstatemask;
+ cp_new->mode |= CTINFO_MODE_DSCP;
+ } else {
+ cp_new->mode &= ~CTINFO_MODE_DSCP;
+ }
+
+ if (tb[TCA_CTINFO_PARMS_CPMARK_MASK]) {
+ cp_new->cpmarkmask =
+ nla_get_u32(tb[TCA_CTINFO_PARMS_CPMARK_MASK]);
+ cp_new->mode |= CTINFO_MODE_CPMARK;
+ } else {
+ cp_new->mode &= ~CTINFO_MODE_CPMARK;
+ }
+
+ spin_lock_bh(&ci->tcf_lock);
+ goto_ch = tcf_action_set_ctrlact(*a, actparm->action, goto_ch);
+ rcu_swap_protected(ci->params, cp_new,
+ lockdep_is_held(&ci->tcf_lock));
+ spin_unlock_bh(&ci->tcf_lock);
+
+ if (goto_ch)
+ tcf_chain_put_by_act(goto_ch);
+ if (cp_new)
+ kfree_rcu(cp_new, rcu);
+
+ if (ret == ACT_P_CREATED)
+ tcf_idr_insert(tn, *a);
+
+ return ret;
+
+put_chain:
+ if (goto_ch)
+ tcf_chain_put_by_act(goto_ch);
+release_idr:
+ tcf_idr_release(*a, bind);
+ return err;
+}
+
+static int tcf_ctinfo_dump(struct sk_buff *skb, struct tc_action *a,
+ int bind, int ref)
+{
+ struct tcf_ctinfo *ci = to_ctinfo(a);
+ struct tc_ctinfo opt = {
+ .index = ci->tcf_index,
+ .refcnt = refcount_read(&ci->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&ci->tcf_bindcnt) - bind,
+ };
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tcf_ctinfo_params *cp;
+ struct tcf_t t;
+
+ spin_lock_bh(&ci->tcf_lock);
+ cp = rcu_dereference_protected(ci->params,
+ lockdep_is_held(&ci->tcf_lock));
+
+ tcf_tm_dump(&t, &ci->tcf_tm);
+ if (nla_put_64bit(skb, TCA_CTINFO_TM, sizeof(t), &t, TCA_CTINFO_PAD))
+ goto nla_put_failure;
+
+ opt.action = ci->tcf_action;
+ if (nla_put(skb, TCA_CTINFO_ACT, sizeof(opt), &opt))
+ goto nla_put_failure;
+
+ if (nla_put_u16(skb, TCA_CTINFO_ZONE, cp->zone))
+ goto nla_put_failure;
+
+ if (cp->mode & CTINFO_MODE_DSCP) {
+ if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_MASK,
+ cp->dscpmask))
+ goto nla_put_failure;
+ if (nla_put_u32(skb, TCA_CTINFO_PARMS_DSCP_STATEMASK,
+ cp->dscpstatemask))
+ goto nla_put_failure;
+ }
+
+ if (cp->mode & CTINFO_MODE_CPMARK) {
+ if (nla_put_u32(skb, TCA_CTINFO_PARMS_CPMARK_MASK,
+ cp->cpmarkmask))
+ goto nla_put_failure;
+ }
+
+ if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_SET,
+ ci->stats_dscp_set, TCA_CTINFO_PAD))
+ goto nla_put_failure;
+
+ if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_DSCP_ERROR,
+ ci->stats_dscp_error, TCA_CTINFO_PAD))
+ goto nla_put_failure;
+
+ if (nla_put_u64_64bit(skb, TCA_CTINFO_STATS_CPMARK_SET,
+ ci->stats_cpmark_set, TCA_CTINFO_PAD))
+ goto nla_put_failure;
+
+ spin_unlock_bh(&ci->tcf_lock);
+ return skb->len;
+
+nla_put_failure:
+ spin_unlock_bh(&ci->tcf_lock);
+ nlmsg_trim(skb, b);
+ return -1;
+}
+
+static int tcf_ctinfo_walker(struct net *net, struct sk_buff *skb,
+ struct netlink_callback *cb, int type,
+ const struct tc_action_ops *ops,
+ struct netlink_ext_ack *extack)
+{
+ struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
+
+ return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_ctinfo_search(struct net *net, struct tc_action **a, u32 index)
+{
+ struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
+
+ return tcf_idr_search(tn, a, index);
+}
+
+static struct tc_action_ops act_ctinfo_ops = {
+ .kind = "ctinfo",
+ .id = TCA_ID_CTINFO,
+ .owner = THIS_MODULE,
+ .act = tcf_ctinfo_act,
+ .dump = tcf_ctinfo_dump,
+ .init = tcf_ctinfo_init,
+ .walk = tcf_ctinfo_walker,
+ .lookup = tcf_ctinfo_search,
+ .size = sizeof(struct tcf_ctinfo),
+};
+
+static __net_init int ctinfo_init_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, ctinfo_net_id);
+
+ return tc_action_net_init(tn, &act_ctinfo_ops);
+}
+
+static void __net_exit ctinfo_exit_net(struct list_head *net_list)
+{
+ tc_action_net_exit(net_list, ctinfo_net_id);
+}
+
+static struct pernet_operations ctinfo_net_ops = {
+ .init = ctinfo_init_net,
+ .exit_batch = ctinfo_exit_net,
+ .id = &ctinfo_net_id,
+ .size = sizeof(struct tc_action_net),
+};
+
+static int __init ctinfo_init_module(void)
+{
+ return tcf_register_action(&act_ctinfo_ops, &ctinfo_net_ops);
+}
+
+static void __exit ctinfo_cleanup_module(void)
+{
+ tcf_unregister_action(&act_ctinfo_ops, &ctinfo_net_ops);
+}
+
+module_init(ctinfo_init_module);
+module_exit(ctinfo_cleanup_module);
+MODULE_AUTHOR("Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>");
+MODULE_DESCRIPTION("Connection tracking mark actions");
+MODULE_LICENSE("GPL");