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// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
/* Copyright (C) 2019 Netronome Systems, Inc. */
#include <linux/if_arp.h>
#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, mac_len;
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);
mac_len = skb->mac_len;
} else {
mac_len = skb_network_header(skb) - skb_mac_header(skb);
}
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, mac_len,
skb->dev && skb->dev->type == ARPHRD_ETHER))
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, mac_len))
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_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, u32 flags,
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;
u32 index;
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]);
index = parm->index;
/* 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, &index, a, bind);
if (err < 0)
return err;
exists = err;
if (exists && bind)
return 0;
if (!exists) {
ret = tcf_idr_create(tn,
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