mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Pedro Tammela](/assets/img/avatar_default.png)
Expose the necessary tc act functions and wire up act_api to use direct calls in retpoline kernels. Signed-off-by: Pedro Tammela <pctammela@mojatatu.com> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
325 lines
8 KiB
C
325 lines
8 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* net/sched/act_skbmod.c skb data modifier
|
|
*
|
|
* Copyright (c) 2016 Jamal Hadi Salim <jhs@mojatatu.com>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/if_arp.h>
|
|
#include <linux/init.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/rtnetlink.h>
|
|
#include <net/inet_ecn.h>
|
|
#include <net/netlink.h>
|
|
#include <net/pkt_sched.h>
|
|
#include <net/pkt_cls.h>
|
|
#include <net/tc_wrapper.h>
|
|
|
|
#include <linux/tc_act/tc_skbmod.h>
|
|
#include <net/tc_act/tc_skbmod.h>
|
|
|
|
static struct tc_action_ops act_skbmod_ops;
|
|
|
|
TC_INDIRECT_SCOPE int tcf_skbmod_act(struct sk_buff *skb,
|
|
const struct tc_action *a,
|
|
struct tcf_result *res)
|
|
{
|
|
struct tcf_skbmod *d = to_skbmod(a);
|
|
int action, max_edit_len, err;
|
|
struct tcf_skbmod_params *p;
|
|
u64 flags;
|
|
|
|
tcf_lastuse_update(&d->tcf_tm);
|
|
bstats_update(this_cpu_ptr(d->common.cpu_bstats), skb);
|
|
|
|
action = READ_ONCE(d->tcf_action);
|
|
if (unlikely(action == TC_ACT_SHOT))
|
|
goto drop;
|
|
|
|
max_edit_len = skb_mac_header_len(skb);
|
|
p = rcu_dereference_bh(d->skbmod_p);
|
|
flags = p->flags;
|
|
|
|
/* tcf_skbmod_init() guarantees "flags" to be one of the following:
|
|
* 1. a combination of SKBMOD_F_{DMAC,SMAC,ETYPE}
|
|
* 2. SKBMOD_F_SWAPMAC
|
|
* 3. SKBMOD_F_ECN
|
|
* SKBMOD_F_ECN only works with IP packets; all other flags only work with Ethernet
|
|
* packets.
|
|
*/
|
|
if (flags == SKBMOD_F_ECN) {
|
|
switch (skb_protocol(skb, true)) {
|
|
case cpu_to_be16(ETH_P_IP):
|
|
case cpu_to_be16(ETH_P_IPV6):
|
|
max_edit_len += skb_network_header_len(skb);
|
|
break;
|
|
default:
|
|
goto out;
|
|
}
|
|
} else if (!skb->dev || skb->dev->type != ARPHRD_ETHER) {
|
|
goto out;
|
|
}
|
|
|
|
err = skb_ensure_writable(skb, max_edit_len);
|
|
if (unlikely(err)) /* best policy is to drop on the floor */
|
|
goto drop;
|
|
|
|
if (flags & SKBMOD_F_DMAC)
|
|
ether_addr_copy(eth_hdr(skb)->h_dest, p->eth_dst);
|
|
if (flags & SKBMOD_F_SMAC)
|
|
ether_addr_copy(eth_hdr(skb)->h_source, p->eth_src);
|
|
if (flags & SKBMOD_F_ETYPE)
|
|
eth_hdr(skb)->h_proto = p->eth_type;
|
|
|
|
if (flags & SKBMOD_F_SWAPMAC) {
|
|
u16 tmpaddr[ETH_ALEN / 2]; /* ether_addr_copy() requirement */
|
|
/*XXX: I am sure we can come up with more efficient swapping*/
|
|
ether_addr_copy((u8 *)tmpaddr, eth_hdr(skb)->h_dest);
|
|
ether_addr_copy(eth_hdr(skb)->h_dest, eth_hdr(skb)->h_source);
|
|
ether_addr_copy(eth_hdr(skb)->h_source, (u8 *)tmpaddr);
|
|
}
|
|
|
|
if (flags & SKBMOD_F_ECN)
|
|
INET_ECN_set_ce(skb);
|
|
|
|
out:
|
|
return action;
|
|
|
|
drop:
|
|
qstats_overlimit_inc(this_cpu_ptr(d->common.cpu_qstats));
|
|
return TC_ACT_SHOT;
|
|
}
|
|
|
|
static const struct nla_policy skbmod_policy[TCA_SKBMOD_MAX + 1] = {
|
|
[TCA_SKBMOD_PARMS] = { .len = sizeof(struct tc_skbmod) },
|
|
[TCA_SKBMOD_DMAC] = { .len = ETH_ALEN },
|
|
[TCA_SKBMOD_SMAC] = { .len = ETH_ALEN },
|
|
[TCA_SKBMOD_ETYPE] = { .type = NLA_U16 },
|
|
};
|
|
|
|
static int tcf_skbmod_init(struct net *net, struct nlattr *nla,
|
|
struct nlattr *est, struct tc_action **a,
|
|
struct tcf_proto *tp, u32 flags,
|
|
struct netlink_ext_ack *extack)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, act_skbmod_ops.net_id);
|
|
bool ovr = flags & TCA_ACT_FLAGS_REPLACE;
|
|
bool bind = flags & TCA_ACT_FLAGS_BIND;
|
|
struct nlattr *tb[TCA_SKBMOD_MAX + 1];
|
|
struct tcf_skbmod_params *p, *p_old;
|
|
struct tcf_chain *goto_ch = NULL;
|
|
struct tc_skbmod *parm;
|
|
u32 lflags = 0, index;
|
|
struct tcf_skbmod *d;
|
|
bool exists = false;
|
|
u8 *daddr = NULL;
|
|
u8 *saddr = NULL;
|
|
u16 eth_type = 0;
|
|
int ret = 0, err;
|
|
|
|
if (!nla)
|
|
return -EINVAL;
|
|
|
|
err = nla_parse_nested_deprecated(tb, TCA_SKBMOD_MAX, nla,
|
|
skbmod_policy, NULL);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
if (!tb[TCA_SKBMOD_PARMS])
|
|
return -EINVAL;
|
|
|
|
if (tb[TCA_SKBMOD_DMAC]) {
|
|
daddr = nla_data(tb[TCA_SKBMOD_DMAC]);
|
|
lflags |= SKBMOD_F_DMAC;
|
|
}
|
|
|
|
if (tb[TCA_SKBMOD_SMAC]) {
|
|
saddr = nla_data(tb[TCA_SKBMOD_SMAC]);
|
|
lflags |= SKBMOD_F_SMAC;
|
|
}
|
|
|
|
if (tb[TCA_SKBMOD_ETYPE]) {
|
|
eth_type = nla_get_u16(tb[TCA_SKBMOD_ETYPE]);
|
|
lflags |= SKBMOD_F_ETYPE;
|
|
}
|
|
|
|
parm = nla_data(tb[TCA_SKBMOD_PARMS]);
|
|
index = parm->index;
|
|
if (parm->flags & SKBMOD_F_SWAPMAC)
|
|
lflags = SKBMOD_F_SWAPMAC;
|
|
if (parm->flags & SKBMOD_F_ECN)
|
|
lflags = SKBMOD_F_ECN;
|
|
|
|
err = tcf_idr_check_alloc(tn, &index, a, bind);
|
|
if (err < 0)
|
|
return err;
|
|
exists = err;
|
|
if (exists && bind)
|
|
return 0;
|
|
|
|
if (!lflags) {
|
|
if (exists)
|
|
tcf_idr_release(*a, bind);
|
|
else
|
|
tcf_idr_cleanup(tn, index);
|
|
return -EINVAL;
|
|
}
|
|
|
|
if (!exists) {
|
|
ret = tcf_idr_create(tn, index, est, a,
|
|
&act_skbmod_ops, bind, true, flags);
|
|
if (ret) {
|
|
tcf_idr_cleanup(tn, 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;
|
|
|
|
d = to_skbmod(*a);
|
|
|
|
p = kzalloc(sizeof(struct tcf_skbmod_params), GFP_KERNEL);
|
|
if (unlikely(!p)) {
|
|
err = -ENOMEM;
|
|
goto put_chain;
|
|
}
|
|
|
|
p->flags = lflags;
|
|
|
|
if (ovr)
|
|
spin_lock_bh(&d->tcf_lock);
|
|
/* Protected by tcf_lock if overwriting existing action. */
|
|
goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
|
|
p_old = rcu_dereference_protected(d->skbmod_p, 1);
|
|
|
|
if (lflags & SKBMOD_F_DMAC)
|
|
ether_addr_copy(p->eth_dst, daddr);
|
|
if (lflags & SKBMOD_F_SMAC)
|
|
ether_addr_copy(p->eth_src, saddr);
|
|
if (lflags & SKBMOD_F_ETYPE)
|
|
p->eth_type = htons(eth_type);
|
|
|
|
rcu_assign_pointer(d->skbmod_p, p);
|
|
if (ovr)
|
|
spin_unlock_bh(&d->tcf_lock);
|
|
|
|
if (p_old)
|
|
kfree_rcu(p_old, rcu);
|
|
if (goto_ch)
|
|
tcf_chain_put_by_act(goto_ch);
|
|
|
|
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_skbmod_cleanup(struct tc_action *a)
|
|
{
|
|
struct tcf_skbmod *d = to_skbmod(a);
|
|
struct tcf_skbmod_params *p;
|
|
|
|
p = rcu_dereference_protected(d->skbmod_p, 1);
|
|
if (p)
|
|
kfree_rcu(p, rcu);
|
|
}
|
|
|
|
static int tcf_skbmod_dump(struct sk_buff *skb, struct tc_action *a,
|
|
int bind, int ref)
|
|
{
|
|
struct tcf_skbmod *d = to_skbmod(a);
|
|
unsigned char *b = skb_tail_pointer(skb);
|
|
struct tcf_skbmod_params *p;
|
|
struct tc_skbmod opt = {
|
|
.index = d->tcf_index,
|
|
.refcnt = refcount_read(&d->tcf_refcnt) - ref,
|
|
.bindcnt = atomic_read(&d->tcf_bindcnt) - bind,
|
|
};
|
|
struct tcf_t t;
|
|
|
|
spin_lock_bh(&d->tcf_lock);
|
|
opt.action = d->tcf_action;
|
|
p = rcu_dereference_protected(d->skbmod_p,
|
|
lockdep_is_held(&d->tcf_lock));
|
|
opt.flags = p->flags;
|
|
if (nla_put(skb, TCA_SKBMOD_PARMS, sizeof(opt), &opt))
|
|
goto nla_put_failure;
|
|
if ((p->flags & SKBMOD_F_DMAC) &&
|
|
nla_put(skb, TCA_SKBMOD_DMAC, ETH_ALEN, p->eth_dst))
|
|
goto nla_put_failure;
|
|
if ((p->flags & SKBMOD_F_SMAC) &&
|
|
nla_put(skb, TCA_SKBMOD_SMAC, ETH_ALEN, p->eth_src))
|
|
goto nla_put_failure;
|
|
if ((p->flags & SKBMOD_F_ETYPE) &&
|
|
nla_put_u16(skb, TCA_SKBMOD_ETYPE, ntohs(p->eth_type)))
|
|
goto nla_put_failure;
|
|
|
|
tcf_tm_dump(&t, &d->tcf_tm);
|
|
if (nla_put_64bit(skb, TCA_SKBMOD_TM, sizeof(t), &t, TCA_SKBMOD_PAD))
|
|
goto nla_put_failure;
|
|
|
|
spin_unlock_bh(&d->tcf_lock);
|
|
return skb->len;
|
|
nla_put_failure:
|
|
spin_unlock_bh(&d->tcf_lock);
|
|
nlmsg_trim(skb, b);
|
|
return -1;
|
|
}
|
|
|
|
static struct tc_action_ops act_skbmod_ops = {
|
|
.kind = "skbmod",
|
|
.id = TCA_ACT_SKBMOD,
|
|
.owner = THIS_MODULE,
|
|
.act = tcf_skbmod_act,
|
|
.dump = tcf_skbmod_dump,
|
|
.init = tcf_skbmod_init,
|
|
.cleanup = tcf_skbmod_cleanup,
|
|
.size = sizeof(struct tcf_skbmod),
|
|
};
|
|
|
|
static __net_init int skbmod_init_net(struct net *net)
|
|
{
|
|
struct tc_action_net *tn = net_generic(net, act_skbmod_ops.net_id);
|
|
|
|
return tc_action_net_init(net, tn, &act_skbmod_ops);
|
|
}
|
|
|
|
static void __net_exit skbmod_exit_net(struct list_head *net_list)
|
|
{
|
|
tc_action_net_exit(net_list, act_skbmod_ops.net_id);
|
|
}
|
|
|
|
static struct pernet_operations skbmod_net_ops = {
|
|
.init = skbmod_init_net,
|
|
.exit_batch = skbmod_exit_net,
|
|
.id = &act_skbmod_ops.net_id,
|
|
.size = sizeof(struct tc_action_net),
|
|
};
|
|
|
|
MODULE_AUTHOR("Jamal Hadi Salim, <jhs@mojatatu.com>");
|
|
MODULE_DESCRIPTION("SKB data mod-ing");
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static int __init skbmod_init_module(void)
|
|
{
|
|
return tcf_register_action(&act_skbmod_ops, &skbmod_net_ops);
|
|
}
|
|
|
|
static void __exit skbmod_cleanup_module(void)
|
|
{
|
|
tcf_unregister_action(&act_skbmod_ops, &skbmod_net_ops);
|
|
}
|
|
|
|
module_init(skbmod_init_module);
|
|
module_exit(skbmod_cleanup_module);
|