--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+/* Copyright (C) 2019 Netronome Systems, Inc. */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mpls.h>
+#include <linux/rtnetlink.h>
+#include <linux/skbuff.h>
+#include <linux/tc_act/tc_mpls.h>
+#include <net/mpls.h>
+#include <net/netlink.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/tc_act/tc_mpls.h>
+
+static unsigned int mpls_net_id;
+static struct tc_action_ops act_mpls_ops;
+
+#define ACT_MPLS_TTL_DEFAULT 255
+
+static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse,
+ struct tcf_mpls_params *p, bool set_bos)
+{
+ u32 new_lse = 0;
+
+ if (lse)
+ new_lse = be32_to_cpu(lse->label_stack_entry);
+
+ if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) {
+ new_lse &= ~MPLS_LS_LABEL_MASK;
+ new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT;
+ }
+ if (p->tcfm_ttl) {
+ new_lse &= ~MPLS_LS_TTL_MASK;
+ new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT;
+ }
+ if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) {
+ new_lse &= ~MPLS_LS_TC_MASK;
+ new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT;
+ }
+ if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) {
+ new_lse &= ~MPLS_LS_S_MASK;
+ new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT;
+ } else if (set_bos) {
+ new_lse |= 1 << MPLS_LS_S_SHIFT;
+ }
+
+ return cpu_to_be32(new_lse);
+}
+
+static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
+ struct tcf_result *res)
+{
+ struct tcf_mpls *m = to_mpls(a);
+ struct tcf_mpls_params *p;
+ __be32 new_lse;
+ int ret;
+
+ tcf_lastuse_update(&m->tcf_tm);
+ bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
+
+ /* Ensure 'data' points at mac_header prior calling mpls manipulating
+ * functions.
+ */
+ if (skb_at_tc_ingress(skb))
+ skb_push_rcsum(skb, skb->mac_len);
+
+ ret = READ_ONCE(m->tcf_action);
+
+ p = rcu_dereference_bh(m->mpls_p);
+
+ switch (p->tcfm_action) {
+ case TCA_MPLS_ACT_POP:
+ if (skb_mpls_pop(skb, p->tcfm_proto))
+ goto drop;
+ break;
+ case TCA_MPLS_ACT_PUSH:
+ new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb->protocol));
+ if (skb_mpls_push(skb, new_lse, p->tcfm_proto))
+ goto drop;
+ break;
+ case TCA_MPLS_ACT_MODIFY:
+ new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
+ if (skb_mpls_update_lse(skb, new_lse))
+ goto drop;
+ break;
+ case TCA_MPLS_ACT_DEC_TTL:
+ if (skb_mpls_dec_ttl(skb))
+ goto drop;
+ break;
+ }
+
+ if (skb_at_tc_ingress(skb))
+ skb_pull_rcsum(skb, skb->mac_len);
+
+ return ret;
+
+drop:
+ qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
+ return TC_ACT_SHOT;
+}
+
+static int valid_label(const struct nlattr *attr,
+ struct netlink_ext_ack *extack)
+{
+ const u32 *label = nla_data(attr);
+
+ if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
+ NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
+ [TCA_MPLS_UNSPEC] = { .strict_start_type = TCA_MPLS_UNSPEC + 1 },
+ [TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
+ [TCA_MPLS_PROTO] = { .type = NLA_U16 },
+ [TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
+ [TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
+ [TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
+ [TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
+};
+
+static int tcf_mpls_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, mpls_net_id);
+ struct nlattr *tb[TCA_MPLS_MAX + 1];
+ struct tcf_chain *goto_ch = NULL;
+ struct tcf_mpls_params *p;
+ struct tc_mpls *parm;
+ bool exists = false;
+ struct tcf_mpls *m;
+ int ret = 0, err;
+ u8 mpls_ttl = 0;
+
+ if (!nla) {
+ NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
+ return -EINVAL;
+ }
+
+ err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
+ if (err < 0)
+ return err;
+
+ if (!tb[TCA_MPLS_PARMS]) {
+ NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
+ return -EINVAL;
+ }
+ parm = nla_data(tb[TCA_MPLS_PARMS]);
+
+ /* Verify parameters against action type. */
+ switch (parm->m_action) {
+ case TCA_MPLS_ACT_POP:
+ if (!tb[TCA_MPLS_PROTO]) {
+ NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
+ return -EINVAL;
+ }
+ if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
+ NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
+ return -EINVAL;
+ }
+ if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
+ tb[TCA_MPLS_BOS]) {
+ NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
+ return -EINVAL;
+ }
+ break;
+ case TCA_MPLS_ACT_DEC_TTL:
+ if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
+ tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
+ NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
+ return -EINVAL;
+ }
+ break;
+ case TCA_MPLS_ACT_PUSH:
+ if (!tb[TCA_MPLS_LABEL]) {
+ NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
+ return -EINVAL;
+ }
+ if (tb[TCA_MPLS_PROTO] &&
+ !eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
+ NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
+ return -EPROTONOSUPPORT;
+ }
+ /* Push needs a TTL - if not specified, set a default value. */
+ if (!tb[TCA_MPLS_TTL]) {
+#if IS_ENABLED(CONFIG_MPLS)
+ mpls_ttl = net->mpls.default_ttl ?
+ net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
+#else
+ mpls_ttl = ACT_MPLS_TTL_DEFAULT;
+#endif
+ }
+ break;
+ case TCA_MPLS_ACT_MODIFY:
+ if (tb[TCA_MPLS_PROTO]) {
+ NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
+ return -EINVAL;
+ }
+ break;
+ default:
+ NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
+ return -EINVAL;
+ }
+
+ err = tcf_idr_check_alloc(tn, &parm->index, a, bind);
+ if (err < 0)
+ return err;
+ exists = err;
+ if (exists && bind)
+ return 0;
+
+ if (!exists) {
+ ret = tcf_idr_create(tn, parm->index, est, a,
+ &act_mpls_ops, bind, true);
+ if (ret) {
+ tcf_idr_cleanup(tn, parm->index);
+ return ret;
+ }
+
+ ret = ACT_P_CREATED;
+ } else if (!ovr) {
+ tcf_idr_release(*a, bind);
+ return -EEXIST;
+ }
+
+ err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
+ if (err < 0)
+ goto release_idr;
+
+ m = to_mpls(*a);
+
+ p = kzalloc(sizeof(*p), GFP_KERNEL);
+ if (!p) {
+ err = -ENOMEM;
+ goto put_chain;
+ }
+
+ p->tcfm_action = parm->m_action;
+ p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
+ ACT_MPLS_LABEL_NOT_SET;
+ p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
+ ACT_MPLS_TC_NOT_SET;
+ p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
+ mpls_ttl;
+ p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
+ ACT_MPLS_BOS_NOT_SET;
+ p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
+ htons(ETH_P_MPLS_UC);
+
+ spin_lock_bh(&m->tcf_lock);
+ goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
+ rcu_swap_protected(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
+ spin_unlock_bh(&m->tcf_lock);
+
+ if (goto_ch)
+ tcf_chain_put_by_act(goto_ch);
+ if (p)
+ kfree_rcu(p, 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 void tcf_mpls_cleanup(struct tc_action *a)
+{
+ struct tcf_mpls *m = to_mpls(a);
+ struct tcf_mpls_params *p;
+
+ p = rcu_dereference_protected(m->mpls_p, 1);
+ if (p)
+ kfree_rcu(p, rcu);
+}
+
+static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
+ int bind, int ref)
+{
+ unsigned char *b = skb_tail_pointer(skb);
+ struct tcf_mpls *m = to_mpls(a);
+ struct tcf_mpls_params *p;
+ struct tc_mpls opt = {
+ .index = m->tcf_index,
+ .refcnt = refcount_read(&m->tcf_refcnt) - ref,
+ .bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
+ };
+ struct tcf_t t;
+
+ spin_lock_bh(&m->tcf_lock);
+ opt.action = m->tcf_action;
+ p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
+ opt.m_action = p->tcfm_action;
+
+ if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
+ goto nla_put_failure;
+
+ if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
+ nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
+ goto nla_put_failure;
+
+ if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
+ nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
+ goto nla_put_failure;
+
+ if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
+ goto nla_put_failure;
+
+ if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
+ nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
+ goto nla_put_failure;
+
+ if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
+ goto nla_put_failure;
+
+ tcf_tm_dump(&t, &m->tcf_tm);
+
+ if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
+ goto nla_put_failure;
+
+ spin_unlock_bh(&m->tcf_lock);
+
+ return skb->len;
+
+nla_put_failure:
+ spin_unlock_bh(&m->tcf_lock);
+ nlmsg_trim(skb, b);
+ return -EMSGSIZE;
+}
+
+static int tcf_mpls_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, mpls_net_id);
+
+ return tcf_generic_walker(tn, skb, cb, type, ops, extack);
+}
+
+static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
+{
+ struct tc_action_net *tn = net_generic(net, mpls_net_id);
+
+ return tcf_idr_search(tn, a, index);
+}
+
+static struct tc_action_ops act_mpls_ops = {
+ .kind = "mpls",
+ .id = TCA_ID_MPLS,
+ .owner = THIS_MODULE,
+ .act = tcf_mpls_act,
+ .dump = tcf_mpls_dump,
+ .init = tcf_mpls_init,
+ .cleanup = tcf_mpls_cleanup,
+ .walk = tcf_mpls_walker,
+ .lookup = tcf_mpls_search,
+ .size = sizeof(struct tcf_mpls),
+};
+
+static __net_init int mpls_init_net(struct net *net)
+{
+ struct tc_action_net *tn = net_generic(net, mpls_net_id);
+
+ return tc_action_net_init(tn, &act_mpls_ops);
+}
+
+static void __net_exit mpls_exit_net(struct list_head *net_list)
+{
+ tc_action_net_exit(net_list, mpls_net_id);
+}
+
+static struct pernet_operations mpls_net_ops = {
+ .init = mpls_init_net,
+ .exit_batch = mpls_exit_net,
+ .id = &mpls_net_id,
+ .size = sizeof(struct tc_action_net),
+};
+
+static int __init mpls_init_module(void)
+{
+ return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
+}
+
+static void __exit mpls_cleanup_module(void)
+{
+ tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
+}
+
+module_init(mpls_init_module);
+module_exit(mpls_cleanup_module);
+
+MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("MPLS manipulation actions");