mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-27 06:34:11 +08:00
9608fa6530
when 'act_mpls' is used to mangle the LSE, the current value is read from
the packet dereferencing 4 bytes at mpls_hdr(): ensure that the label is
contained in the skb "linear" area.
Found by code inspection.
v2:
- use MPLS_HLEN instead of sizeof(new_lse), thanks to Jakub Kicinski
Fixes: 2a2ea50870
("net: sched: add mpls manipulation actions to TC")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Link: https://lore.kernel.org/r/3243506cba43d14858f3bd21ee0994160e44d64a.1606987058.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
436 lines
11 KiB
C
436 lines
11 KiB
C
// SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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/* Copyright (C) 2019 Netronome Systems, Inc. */
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#include <linux/if_arp.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/mpls.h>
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#include <linux/rtnetlink.h>
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#include <linux/skbuff.h>
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#include <linux/tc_act/tc_mpls.h>
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#include <net/mpls.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <net/pkt_cls.h>
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#include <net/tc_act/tc_mpls.h>
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static unsigned int mpls_net_id;
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static struct tc_action_ops act_mpls_ops;
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#define ACT_MPLS_TTL_DEFAULT 255
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static __be32 tcf_mpls_get_lse(struct mpls_shim_hdr *lse,
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struct tcf_mpls_params *p, bool set_bos)
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{
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u32 new_lse = 0;
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if (lse)
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new_lse = be32_to_cpu(lse->label_stack_entry);
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if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET) {
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new_lse &= ~MPLS_LS_LABEL_MASK;
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new_lse |= p->tcfm_label << MPLS_LS_LABEL_SHIFT;
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}
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if (p->tcfm_ttl) {
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new_lse &= ~MPLS_LS_TTL_MASK;
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new_lse |= p->tcfm_ttl << MPLS_LS_TTL_SHIFT;
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}
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if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET) {
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new_lse &= ~MPLS_LS_TC_MASK;
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new_lse |= p->tcfm_tc << MPLS_LS_TC_SHIFT;
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}
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if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET) {
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new_lse &= ~MPLS_LS_S_MASK;
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new_lse |= p->tcfm_bos << MPLS_LS_S_SHIFT;
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} else if (set_bos) {
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new_lse |= 1 << MPLS_LS_S_SHIFT;
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}
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return cpu_to_be32(new_lse);
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}
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static int tcf_mpls_act(struct sk_buff *skb, const struct tc_action *a,
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struct tcf_result *res)
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{
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struct tcf_mpls *m = to_mpls(a);
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struct tcf_mpls_params *p;
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__be32 new_lse;
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int ret, mac_len;
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tcf_lastuse_update(&m->tcf_tm);
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bstats_cpu_update(this_cpu_ptr(m->common.cpu_bstats), skb);
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/* Ensure 'data' points at mac_header prior calling mpls manipulating
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* functions.
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*/
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if (skb_at_tc_ingress(skb)) {
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skb_push_rcsum(skb, skb->mac_len);
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mac_len = skb->mac_len;
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} else {
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mac_len = skb_network_header(skb) - skb_mac_header(skb);
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}
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ret = READ_ONCE(m->tcf_action);
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p = rcu_dereference_bh(m->mpls_p);
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switch (p->tcfm_action) {
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case TCA_MPLS_ACT_POP:
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if (skb_mpls_pop(skb, p->tcfm_proto, mac_len,
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skb->dev && skb->dev->type == ARPHRD_ETHER))
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goto drop;
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break;
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case TCA_MPLS_ACT_PUSH:
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new_lse = tcf_mpls_get_lse(NULL, p, !eth_p_mpls(skb_protocol(skb, true)));
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if (skb_mpls_push(skb, new_lse, p->tcfm_proto, mac_len,
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skb->dev && skb->dev->type == ARPHRD_ETHER))
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goto drop;
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break;
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case TCA_MPLS_ACT_MAC_PUSH:
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if (skb_vlan_tag_present(skb)) {
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if (__vlan_insert_inner_tag(skb, skb->vlan_proto,
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skb_vlan_tag_get(skb),
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ETH_HLEN) < 0)
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goto drop;
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skb->protocol = skb->vlan_proto;
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__vlan_hwaccel_clear_tag(skb);
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}
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new_lse = tcf_mpls_get_lse(NULL, p, mac_len ||
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!eth_p_mpls(skb->protocol));
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if (skb_mpls_push(skb, new_lse, p->tcfm_proto, 0, false))
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goto drop;
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break;
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case TCA_MPLS_ACT_MODIFY:
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if (!pskb_may_pull(skb,
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skb_network_offset(skb) + MPLS_HLEN))
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goto drop;
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new_lse = tcf_mpls_get_lse(mpls_hdr(skb), p, false);
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if (skb_mpls_update_lse(skb, new_lse))
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goto drop;
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break;
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case TCA_MPLS_ACT_DEC_TTL:
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if (skb_mpls_dec_ttl(skb))
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goto drop;
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break;
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}
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if (skb_at_tc_ingress(skb))
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skb_pull_rcsum(skb, skb->mac_len);
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return ret;
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drop:
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qstats_drop_inc(this_cpu_ptr(m->common.cpu_qstats));
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return TC_ACT_SHOT;
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}
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static int valid_label(const struct nlattr *attr,
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struct netlink_ext_ack *extack)
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{
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const u32 *label = nla_data(attr);
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if (*label & ~MPLS_LABEL_MASK || *label == MPLS_LABEL_IMPLNULL) {
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NL_SET_ERR_MSG_MOD(extack, "MPLS label out of range");
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return -EINVAL;
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}
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return 0;
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}
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static const struct nla_policy mpls_policy[TCA_MPLS_MAX + 1] = {
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[TCA_MPLS_PARMS] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_mpls)),
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[TCA_MPLS_PROTO] = { .type = NLA_U16 },
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[TCA_MPLS_LABEL] = NLA_POLICY_VALIDATE_FN(NLA_U32, valid_label),
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[TCA_MPLS_TC] = NLA_POLICY_RANGE(NLA_U8, 0, 7),
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[TCA_MPLS_TTL] = NLA_POLICY_MIN(NLA_U8, 1),
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[TCA_MPLS_BOS] = NLA_POLICY_RANGE(NLA_U8, 0, 1),
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};
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static int tcf_mpls_init(struct net *net, struct nlattr *nla,
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struct nlattr *est, struct tc_action **a,
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int ovr, int bind, bool rtnl_held,
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struct tcf_proto *tp, u32 flags,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, mpls_net_id);
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struct nlattr *tb[TCA_MPLS_MAX + 1];
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struct tcf_chain *goto_ch = NULL;
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struct tcf_mpls_params *p;
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struct tc_mpls *parm;
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bool exists = false;
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struct tcf_mpls *m;
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int ret = 0, err;
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u8 mpls_ttl = 0;
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u32 index;
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if (!nla) {
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NL_SET_ERR_MSG_MOD(extack, "Missing netlink attributes");
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return -EINVAL;
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}
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err = nla_parse_nested(tb, TCA_MPLS_MAX, nla, mpls_policy, extack);
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if (err < 0)
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return err;
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if (!tb[TCA_MPLS_PARMS]) {
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NL_SET_ERR_MSG_MOD(extack, "No MPLS params");
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return -EINVAL;
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}
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parm = nla_data(tb[TCA_MPLS_PARMS]);
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index = parm->index;
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/* Verify parameters against action type. */
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switch (parm->m_action) {
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case TCA_MPLS_ACT_POP:
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if (!tb[TCA_MPLS_PROTO]) {
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NL_SET_ERR_MSG_MOD(extack, "Protocol must be set for MPLS pop");
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return -EINVAL;
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}
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if (!eth_proto_is_802_3(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
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NL_SET_ERR_MSG_MOD(extack, "Invalid protocol type for MPLS pop");
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return -EINVAL;
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}
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if (tb[TCA_MPLS_LABEL] || tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] ||
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tb[TCA_MPLS_BOS]) {
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NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC or BOS cannot be used with MPLS pop");
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return -EINVAL;
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}
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break;
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case TCA_MPLS_ACT_DEC_TTL:
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if (tb[TCA_MPLS_PROTO] || tb[TCA_MPLS_LABEL] ||
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tb[TCA_MPLS_TTL] || tb[TCA_MPLS_TC] || tb[TCA_MPLS_BOS]) {
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NL_SET_ERR_MSG_MOD(extack, "Label, TTL, TC, BOS or protocol cannot be used with MPLS dec_ttl");
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return -EINVAL;
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}
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break;
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case TCA_MPLS_ACT_PUSH:
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case TCA_MPLS_ACT_MAC_PUSH:
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if (!tb[TCA_MPLS_LABEL]) {
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NL_SET_ERR_MSG_MOD(extack, "Label is required for MPLS push");
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return -EINVAL;
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}
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if (tb[TCA_MPLS_PROTO] &&
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!eth_p_mpls(nla_get_be16(tb[TCA_MPLS_PROTO]))) {
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NL_SET_ERR_MSG_MOD(extack, "Protocol must be an MPLS type for MPLS push");
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return -EPROTONOSUPPORT;
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}
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/* Push needs a TTL - if not specified, set a default value. */
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if (!tb[TCA_MPLS_TTL]) {
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#if IS_ENABLED(CONFIG_MPLS)
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mpls_ttl = net->mpls.default_ttl ?
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net->mpls.default_ttl : ACT_MPLS_TTL_DEFAULT;
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#else
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mpls_ttl = ACT_MPLS_TTL_DEFAULT;
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#endif
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}
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break;
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case TCA_MPLS_ACT_MODIFY:
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if (tb[TCA_MPLS_PROTO]) {
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NL_SET_ERR_MSG_MOD(extack, "Protocol cannot be used with MPLS modify");
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return -EINVAL;
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}
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break;
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default:
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NL_SET_ERR_MSG_MOD(extack, "Unknown MPLS action");
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return -EINVAL;
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}
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err = tcf_idr_check_alloc(tn, &index, a, bind);
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if (err < 0)
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return err;
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exists = err;
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if (exists && bind)
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return 0;
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if (!exists) {
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ret = tcf_idr_create(tn, index, est, a,
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&act_mpls_ops, bind, true, 0);
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if (ret) {
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tcf_idr_cleanup(tn, index);
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return ret;
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}
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ret = ACT_P_CREATED;
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} else if (!ovr) {
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tcf_idr_release(*a, bind);
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return -EEXIST;
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}
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err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
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if (err < 0)
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goto release_idr;
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m = to_mpls(*a);
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p = kzalloc(sizeof(*p), GFP_KERNEL);
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if (!p) {
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err = -ENOMEM;
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goto put_chain;
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}
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p->tcfm_action = parm->m_action;
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p->tcfm_label = tb[TCA_MPLS_LABEL] ? nla_get_u32(tb[TCA_MPLS_LABEL]) :
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ACT_MPLS_LABEL_NOT_SET;
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p->tcfm_tc = tb[TCA_MPLS_TC] ? nla_get_u8(tb[TCA_MPLS_TC]) :
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ACT_MPLS_TC_NOT_SET;
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p->tcfm_ttl = tb[TCA_MPLS_TTL] ? nla_get_u8(tb[TCA_MPLS_TTL]) :
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mpls_ttl;
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p->tcfm_bos = tb[TCA_MPLS_BOS] ? nla_get_u8(tb[TCA_MPLS_BOS]) :
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ACT_MPLS_BOS_NOT_SET;
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p->tcfm_proto = tb[TCA_MPLS_PROTO] ? nla_get_be16(tb[TCA_MPLS_PROTO]) :
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htons(ETH_P_MPLS_UC);
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spin_lock_bh(&m->tcf_lock);
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goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
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p = rcu_replace_pointer(m->mpls_p, p, lockdep_is_held(&m->tcf_lock));
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spin_unlock_bh(&m->tcf_lock);
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if (goto_ch)
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tcf_chain_put_by_act(goto_ch);
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if (p)
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kfree_rcu(p, rcu);
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return ret;
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put_chain:
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if (goto_ch)
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tcf_chain_put_by_act(goto_ch);
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release_idr:
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tcf_idr_release(*a, bind);
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return err;
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}
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static void tcf_mpls_cleanup(struct tc_action *a)
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{
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struct tcf_mpls *m = to_mpls(a);
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struct tcf_mpls_params *p;
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p = rcu_dereference_protected(m->mpls_p, 1);
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if (p)
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kfree_rcu(p, rcu);
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}
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static int tcf_mpls_dump(struct sk_buff *skb, struct tc_action *a,
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int bind, int ref)
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{
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unsigned char *b = skb_tail_pointer(skb);
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struct tcf_mpls *m = to_mpls(a);
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struct tcf_mpls_params *p;
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struct tc_mpls opt = {
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.index = m->tcf_index,
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.refcnt = refcount_read(&m->tcf_refcnt) - ref,
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.bindcnt = atomic_read(&m->tcf_bindcnt) - bind,
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};
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struct tcf_t t;
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spin_lock_bh(&m->tcf_lock);
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opt.action = m->tcf_action;
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p = rcu_dereference_protected(m->mpls_p, lockdep_is_held(&m->tcf_lock));
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opt.m_action = p->tcfm_action;
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if (nla_put(skb, TCA_MPLS_PARMS, sizeof(opt), &opt))
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goto nla_put_failure;
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if (p->tcfm_label != ACT_MPLS_LABEL_NOT_SET &&
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nla_put_u32(skb, TCA_MPLS_LABEL, p->tcfm_label))
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goto nla_put_failure;
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if (p->tcfm_tc != ACT_MPLS_TC_NOT_SET &&
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nla_put_u8(skb, TCA_MPLS_TC, p->tcfm_tc))
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goto nla_put_failure;
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if (p->tcfm_ttl && nla_put_u8(skb, TCA_MPLS_TTL, p->tcfm_ttl))
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goto nla_put_failure;
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if (p->tcfm_bos != ACT_MPLS_BOS_NOT_SET &&
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nla_put_u8(skb, TCA_MPLS_BOS, p->tcfm_bos))
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goto nla_put_failure;
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if (nla_put_be16(skb, TCA_MPLS_PROTO, p->tcfm_proto))
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goto nla_put_failure;
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tcf_tm_dump(&t, &m->tcf_tm);
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if (nla_put_64bit(skb, TCA_MPLS_TM, sizeof(t), &t, TCA_MPLS_PAD))
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goto nla_put_failure;
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spin_unlock_bh(&m->tcf_lock);
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return skb->len;
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nla_put_failure:
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spin_unlock_bh(&m->tcf_lock);
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nlmsg_trim(skb, b);
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return -EMSGSIZE;
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}
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static int tcf_mpls_walker(struct net *net, struct sk_buff *skb,
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struct netlink_callback *cb, int type,
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const struct tc_action_ops *ops,
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struct netlink_ext_ack *extack)
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{
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struct tc_action_net *tn = net_generic(net, mpls_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops, extack);
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}
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static int tcf_mpls_search(struct net *net, struct tc_action **a, u32 index)
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{
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struct tc_action_net *tn = net_generic(net, mpls_net_id);
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return tcf_idr_search(tn, a, index);
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}
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static struct tc_action_ops act_mpls_ops = {
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.kind = "mpls",
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.id = TCA_ID_MPLS,
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.owner = THIS_MODULE,
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.act = tcf_mpls_act,
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.dump = tcf_mpls_dump,
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.init = tcf_mpls_init,
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.cleanup = tcf_mpls_cleanup,
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.walk = tcf_mpls_walker,
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.lookup = tcf_mpls_search,
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.size = sizeof(struct tcf_mpls),
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};
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static __net_init int mpls_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, mpls_net_id);
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return tc_action_net_init(net, tn, &act_mpls_ops);
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}
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static void __net_exit mpls_exit_net(struct list_head *net_list)
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{
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tc_action_net_exit(net_list, mpls_net_id);
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}
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static struct pernet_operations mpls_net_ops = {
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.init = mpls_init_net,
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.exit_batch = mpls_exit_net,
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.id = &mpls_net_id,
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.size = sizeof(struct tc_action_net),
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};
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static int __init mpls_init_module(void)
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{
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return tcf_register_action(&act_mpls_ops, &mpls_net_ops);
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}
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static void __exit mpls_cleanup_module(void)
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{
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tcf_unregister_action(&act_mpls_ops, &mpls_net_ops);
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}
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module_init(mpls_init_module);
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module_exit(mpls_cleanup_module);
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MODULE_SOFTDEP("post: mpls_gso");
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MODULE_AUTHOR("Netronome Systems <oss-drivers@netronome.com>");
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MODULE_LICENSE("GPL");
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MODULE_DESCRIPTION("MPLS manipulation actions");
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