1edf8abe04
when the following command
# tc actions replace action vlan pop index 100
is run for the first time, and tcf_vlan_init() fails allocating struct
tcf_vlan_params, tcf_vlan_cleanup() calls kfree_rcu(NULL, ...). This causes
the following error:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000018
IP: __call_rcu+0x23/0x2b0
PGD 80000000760a2067 P4D 80000000760a2067 PUD 742c1067 PMD 0
Oops: 0002 [#1] SMP PTI
Modules linked in: act_vlan(E) ip6table_filter ip6_tables iptable_filter binfmt_misc ext4 snd_hda_codec_generic snd_hda_intel mbcache snd_hda_codec jbd2 snd_hda_core crct10dif_pclmul crc32_pclmul ghash_clmulni_intel pcbc snd_hwdep snd_seq snd_seq_device snd_pcm aesni_intel crypto_simd snd_timer glue_helper snd cryptd joydev soundcore virtio_balloon pcspkr i2c_piix4 nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables xfs libcrc32c ata_generic pata_acpi qxl drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm drm virtio_console virtio_blk virtio_net ata_piix crc32c_intel libata virtio_pci i2c_core virtio_ring serio_raw virtio floppy dm_mirror dm_region_hash dm_log dm_mod [last unloaded: act_vlan]
CPU: 3 PID: 3119 Comm: tc Tainted: G E 4.16.0-rc4.act_vlan.orig+ #403
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
RIP: 0010:__call_rcu+0x23/0x2b0
RSP: 0018:ffffaac3005fb798 EFLAGS: 00010246
RAX: ffffffffc0704080 RBX: ffff97f2b4bbe900 RCX: 00000000ffffffff
RDX: ffffffffabca5f00 RSI: 0000000000000010 RDI: 0000000000000010
RBP: 0000000000000010 R08: 0000000000000001 R09: 0000000000000044
R10: 00000000fd003000 R11: ffff97f2faab5b91 R12: 0000000000000000
R13: ffffffffabca5f00 R14: ffff97f2fb80202c R15: 00000000fffffff4
FS: 00007f68f75b4740(0000) GS:ffff97f2ffd80000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000018 CR3: 0000000072b52001 CR4: 00000000001606e0
Call Trace:
__tcf_idr_release+0x79/0xf0
tcf_vlan_init+0x168/0x270 [act_vlan]
tcf_action_init_1+0x2cc/0x430
tcf_action_init+0xd3/0x1b0
tc_ctl_action+0x18b/0x240
rtnetlink_rcv_msg+0x29c/0x310
? _cond_resched+0x15/0x30
? __kmalloc_node_track_caller+0x1b9/0x270
? rtnl_calcit.isra.28+0x100/0x100
netlink_rcv_skb+0xd2/0x110
netlink_unicast+0x17c/0x230
netlink_sendmsg+0x2cd/0x3c0
sock_sendmsg+0x30/0x40
___sys_sendmsg+0x27a/0x290
? filemap_map_pages+0x34a/0x3a0
? __handle_mm_fault+0xbfd/0xe20
__sys_sendmsg+0x51/0x90
do_syscall_64+0x6e/0x1a0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x7f68f69c5ba0
RSP: 002b:00007fffd79c1118 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fffd79c1240 RCX: 00007f68f69c5ba0
RDX: 0000000000000000 RSI: 00007fffd79c1190 RDI: 0000000000000003
RBP: 000000005aaa708e R08: 0000000000000002 R09: 0000000000000000
R10: 00007fffd79c0ba0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffd79c1254 R14: 0000000000000001 R15: 0000000000669f60
Code: 5d e9 42 da ff ff 66 90 0f 1f 44 00 00 41 57 41 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 08 40 f6 c7 07 0f 85 19 02 00 00 <48> 89 75 08 48 c7 45 00 00 00 00 00 9c 58 0f 1f 44 00 00 49 89
RIP: __call_rcu+0x23/0x2b0 RSP: ffffaac3005fb798
CR2: 0000000000000018
fix this in tcf_vlan_cleanup(), ensuring that kfree_rcu(p, ...) is called
only when p is not NULL.
Fixes: 4c5b9d9642
("act_vlan: VLAN action rewrite to use RCU lock/unlock and update")
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Manish Kurup <manish.kurup@verizon.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
333 lines
7.7 KiB
C
333 lines
7.7 KiB
C
/*
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* Copyright (c) 2014 Jiri Pirko <jiri@resnulli.us>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/skbuff.h>
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#include <linux/rtnetlink.h>
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#include <linux/if_vlan.h>
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#include <net/netlink.h>
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#include <net/pkt_sched.h>
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#include <linux/tc_act/tc_vlan.h>
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#include <net/tc_act/tc_vlan.h>
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static unsigned int vlan_net_id;
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static struct tc_action_ops act_vlan_ops;
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static int tcf_vlan(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_vlan *v = to_vlan(a);
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struct tcf_vlan_params *p;
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int action;
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int err;
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u16 tci;
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tcf_lastuse_update(&v->tcf_tm);
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bstats_cpu_update(this_cpu_ptr(v->common.cpu_bstats), skb);
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/* Ensure 'data' points at mac_header prior calling vlan 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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rcu_read_lock();
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action = READ_ONCE(v->tcf_action);
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p = rcu_dereference(v->vlan_p);
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switch (p->tcfv_action) {
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case TCA_VLAN_ACT_POP:
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err = skb_vlan_pop(skb);
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if (err)
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goto drop;
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break;
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case TCA_VLAN_ACT_PUSH:
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err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
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(p->tcfv_push_prio << VLAN_PRIO_SHIFT));
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if (err)
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goto drop;
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break;
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case TCA_VLAN_ACT_MODIFY:
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/* No-op if no vlan tag (either hw-accel or in-payload) */
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if (!skb_vlan_tagged(skb))
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goto unlock;
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/* extract existing tag (and guarantee no hw-accel tag) */
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if (skb_vlan_tag_present(skb)) {
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tci = skb_vlan_tag_get(skb);
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skb->vlan_tci = 0;
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} else {
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/* in-payload vlan tag, pop it */
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err = __skb_vlan_pop(skb, &tci);
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if (err)
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goto drop;
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}
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/* replace the vid */
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tci = (tci & ~VLAN_VID_MASK) | p->tcfv_push_vid;
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/* replace prio bits, if tcfv_push_prio specified */
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if (p->tcfv_push_prio) {
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tci &= ~VLAN_PRIO_MASK;
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tci |= p->tcfv_push_prio << VLAN_PRIO_SHIFT;
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}
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/* put updated tci as hwaccel tag */
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__vlan_hwaccel_put_tag(skb, p->tcfv_push_proto, tci);
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break;
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default:
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BUG();
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}
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goto unlock;
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drop:
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action = TC_ACT_SHOT;
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qstats_drop_inc(this_cpu_ptr(v->common.cpu_qstats));
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unlock:
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rcu_read_unlock();
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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 action;
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}
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static const struct nla_policy vlan_policy[TCA_VLAN_MAX + 1] = {
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[TCA_VLAN_PARMS] = { .len = sizeof(struct tc_vlan) },
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[TCA_VLAN_PUSH_VLAN_ID] = { .type = NLA_U16 },
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[TCA_VLAN_PUSH_VLAN_PROTOCOL] = { .type = NLA_U16 },
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[TCA_VLAN_PUSH_VLAN_PRIORITY] = { .type = NLA_U8 },
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};
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static int tcf_vlan_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)
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{
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struct tc_action_net *tn = net_generic(net, vlan_net_id);
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struct nlattr *tb[TCA_VLAN_MAX + 1];
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struct tcf_vlan_params *p, *p_old;
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struct tc_vlan *parm;
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struct tcf_vlan *v;
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int action;
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__be16 push_vid = 0;
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__be16 push_proto = 0;
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u8 push_prio = 0;
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bool exists = false;
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int ret = 0, err;
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if (!nla)
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return -EINVAL;
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err = nla_parse_nested(tb, TCA_VLAN_MAX, nla, vlan_policy, NULL);
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if (err < 0)
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return err;
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if (!tb[TCA_VLAN_PARMS])
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return -EINVAL;
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parm = nla_data(tb[TCA_VLAN_PARMS]);
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exists = tcf_idr_check(tn, parm->index, a, bind);
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if (exists && bind)
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return 0;
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switch (parm->v_action) {
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case TCA_VLAN_ACT_POP:
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break;
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case TCA_VLAN_ACT_PUSH:
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case TCA_VLAN_ACT_MODIFY:
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if (!tb[TCA_VLAN_PUSH_VLAN_ID]) {
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if (exists)
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tcf_idr_release(*a, bind);
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return -EINVAL;
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}
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push_vid = nla_get_u16(tb[TCA_VLAN_PUSH_VLAN_ID]);
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if (push_vid >= VLAN_VID_MASK) {
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if (exists)
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tcf_idr_release(*a, bind);
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return -ERANGE;
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}
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if (tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]) {
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push_proto = nla_get_be16(tb[TCA_VLAN_PUSH_VLAN_PROTOCOL]);
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switch (push_proto) {
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case htons(ETH_P_8021Q):
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case htons(ETH_P_8021AD):
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break;
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default:
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return -EPROTONOSUPPORT;
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}
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} else {
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push_proto = htons(ETH_P_8021Q);
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}
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if (tb[TCA_VLAN_PUSH_VLAN_PRIORITY])
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push_prio = nla_get_u8(tb[TCA_VLAN_PUSH_VLAN_PRIORITY]);
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break;
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default:
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if (exists)
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tcf_idr_release(*a, bind);
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return -EINVAL;
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}
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action = parm->v_action;
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if (!exists) {
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ret = tcf_idr_create(tn, parm->index, est, a,
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&act_vlan_ops, bind, true);
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if (ret)
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return ret;
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ret = ACT_P_CREATED;
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} else {
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tcf_idr_release(*a, bind);
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if (!ovr)
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return -EEXIST;
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}
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v = to_vlan(*a);
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ASSERT_RTNL();
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p = kzalloc(sizeof(*p), GFP_KERNEL);
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if (!p) {
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if (ovr)
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tcf_idr_release(*a, bind);
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return -ENOMEM;
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}
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v->tcf_action = parm->action;
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p_old = rtnl_dereference(v->vlan_p);
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p->tcfv_action = action;
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p->tcfv_push_vid = push_vid;
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p->tcfv_push_prio = push_prio;
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p->tcfv_push_proto = push_proto;
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rcu_assign_pointer(v->vlan_p, p);
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if (p_old)
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kfree_rcu(p_old, rcu);
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if (ret == ACT_P_CREATED)
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tcf_idr_insert(tn, *a);
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return ret;
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}
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static void tcf_vlan_cleanup(struct tc_action *a)
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{
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struct tcf_vlan *v = to_vlan(a);
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struct tcf_vlan_params *p;
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p = rcu_dereference_protected(v->vlan_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_vlan_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_vlan *v = to_vlan(a);
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struct tcf_vlan_params *p = rtnl_dereference(v->vlan_p);
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struct tc_vlan opt = {
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.index = v->tcf_index,
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.refcnt = v->tcf_refcnt - ref,
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.bindcnt = v->tcf_bindcnt - bind,
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.action = v->tcf_action,
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.v_action = p->tcfv_action,
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};
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struct tcf_t t;
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if (nla_put(skb, TCA_VLAN_PARMS, sizeof(opt), &opt))
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goto nla_put_failure;
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if ((p->tcfv_action == TCA_VLAN_ACT_PUSH ||
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p->tcfv_action == TCA_VLAN_ACT_MODIFY) &&
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(nla_put_u16(skb, TCA_VLAN_PUSH_VLAN_ID, p->tcfv_push_vid) ||
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nla_put_be16(skb, TCA_VLAN_PUSH_VLAN_PROTOCOL,
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p->tcfv_push_proto) ||
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(nla_put_u8(skb, TCA_VLAN_PUSH_VLAN_PRIORITY,
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p->tcfv_push_prio))))
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goto nla_put_failure;
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tcf_tm_dump(&t, &v->tcf_tm);
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if (nla_put_64bit(skb, TCA_VLAN_TM, sizeof(t), &t, TCA_VLAN_PAD))
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goto nla_put_failure;
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return skb->len;
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nla_put_failure:
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nlmsg_trim(skb, b);
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return -1;
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}
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static int tcf_vlan_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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{
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struct tc_action_net *tn = net_generic(net, vlan_net_id);
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return tcf_generic_walker(tn, skb, cb, type, ops);
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}
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static int tcf_vlan_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, vlan_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_vlan_ops = {
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.kind = "vlan",
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.type = TCA_ACT_VLAN,
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.owner = THIS_MODULE,
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.act = tcf_vlan,
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.dump = tcf_vlan_dump,
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.init = tcf_vlan_init,
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.cleanup = tcf_vlan_cleanup,
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.walk = tcf_vlan_walker,
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.lookup = tcf_vlan_search,
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.size = sizeof(struct tcf_vlan),
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};
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static __net_init int vlan_init_net(struct net *net)
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{
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struct tc_action_net *tn = net_generic(net, vlan_net_id);
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return tc_action_net_init(tn, &act_vlan_ops);
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}
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static void __net_exit vlan_exit_net(struct list_head *net_list)
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{
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tc_action_net_exit(net_list, vlan_net_id);
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}
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static struct pernet_operations vlan_net_ops = {
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.init = vlan_init_net,
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.exit_batch = vlan_exit_net,
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.id = &vlan_net_id,
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.size = sizeof(struct tc_action_net),
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};
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static int __init vlan_init_module(void)
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{
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return tcf_register_action(&act_vlan_ops, &vlan_net_ops);
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}
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static void __exit vlan_cleanup_module(void)
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{
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tcf_unregister_action(&act_vlan_ops, &vlan_net_ops);
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}
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module_init(vlan_init_module);
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module_exit(vlan_cleanup_module);
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MODULE_AUTHOR("Jiri Pirko <jiri@resnulli.us>");
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MODULE_DESCRIPTION("vlan manipulation actions");
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MODULE_LICENSE("GPL v2");
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