kernel_optimize_test/net/sched/act_tunnel_key.c
Alexey Dobriyan c7d03a00b5 netns: make struct pernet_operations::id unsigned int
Make struct pernet_operations::id unsigned.

There are 2 reasons to do so:

1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.

2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.

"int" being used as an array index needs to be sign-extended
to 64-bit before being used.

	void f(long *p, int i)
	{
		g(p[i]);
	}

  roughly translates to

	movsx	rsi, esi
	mov	rdi, [rsi+...]
	call 	g

MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.

Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:

	static inline void *net_generic(const struct net *net, int id)
	{
		...
		ptr = ng->ptr[id - 1];
		...
	}

And this function is used a lot, so those sign extensions add up.

Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)

Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]

However, overall balance is in negative direction:

	add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
	function                                     old     new   delta
	nfsd4_lock                                  3886    3959     +73
	tipc_link_build_proto_msg                   1096    1140     +44
	mac80211_hwsim_new_radio                    2776    2808     +32
	tipc_mon_rcv                                1032    1058     +26
	svcauth_gss_legacy_init                     1413    1429     +16
	tipc_bcbase_select_primary                   379     392     +13
	nfsd4_exchange_id                           1247    1260     +13
	nfsd4_setclientid_confirm                    782     793     +11
		...
	put_client_renew_locked                      494     480     -14
	ip_set_sockfn_get                            730     716     -14
	geneve_sock_add                              829     813     -16
	nfsd4_sequence_done                          721     703     -18
	nlmclnt_lookup_host                          708     686     -22
	nfsd4_lockt                                 1085    1063     -22
	nfs_get_client                              1077    1050     -27
	tcf_bpf_init                                1106    1076     -30
	nfsd4_encode_fattr                          5997    5930     -67
	Total: Before=154856051, After=154854321, chg -0.00%

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-11-18 10:59:15 -05:00

350 lines
8.8 KiB
C

/*
* Copyright (c) 2016, Amir Vadai <amir@vadai.me>
* Copyright (c) 2016, Mellanox Technologies. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/dst.h>
#include <linux/tc_act/tc_tunnel_key.h>
#include <net/tc_act/tc_tunnel_key.h>
#define TUNNEL_KEY_TAB_MASK 15
static unsigned int tunnel_key_net_id;
static struct tc_action_ops act_tunnel_key_ops;
static int tunnel_key_act(struct sk_buff *skb, const struct tc_action *a,
struct tcf_result *res)
{
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
int action;
rcu_read_lock();
params = rcu_dereference(t->params);
tcf_lastuse_update(&t->tcf_tm);
bstats_cpu_update(this_cpu_ptr(t->common.cpu_bstats), skb);
action = params->action;
switch (params->tcft_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
skb_dst_drop(skb);
break;
case TCA_TUNNEL_KEY_ACT_SET:
skb_dst_drop(skb);
skb_dst_set(skb, dst_clone(&params->tcft_enc_metadata->dst));
break;
default:
WARN_ONCE(1, "Bad tunnel_key action %d.\n",
params->tcft_action);
break;
}
rcu_read_unlock();
return action;
}
static const struct nla_policy tunnel_key_policy[TCA_TUNNEL_KEY_MAX + 1] = {
[TCA_TUNNEL_KEY_PARMS] = { .len = sizeof(struct tc_tunnel_key) },
[TCA_TUNNEL_KEY_ENC_IPV4_SRC] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_IPV4_DST] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_IPV6_SRC] = { .len = sizeof(struct in6_addr) },
[TCA_TUNNEL_KEY_ENC_IPV6_DST] = { .len = sizeof(struct in6_addr) },
[TCA_TUNNEL_KEY_ENC_KEY_ID] = { .type = NLA_U32 },
[TCA_TUNNEL_KEY_ENC_DST_PORT] = {.type = NLA_U16},
};
static int tunnel_key_init(struct net *net, struct nlattr *nla,
struct nlattr *est, struct tc_action **a,
int ovr, int bind)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
struct nlattr *tb[TCA_TUNNEL_KEY_MAX + 1];
struct tcf_tunnel_key_params *params_old;
struct tcf_tunnel_key_params *params_new;
struct metadata_dst *metadata = NULL;
struct tc_tunnel_key *parm;
struct tcf_tunnel_key *t;
bool exists = false;
__be16 dst_port = 0;
__be64 key_id;
int ret = 0;
int err;
if (!nla)
return -EINVAL;
err = nla_parse_nested(tb, TCA_TUNNEL_KEY_MAX, nla, tunnel_key_policy);
if (err < 0)
return err;
if (!tb[TCA_TUNNEL_KEY_PARMS])
return -EINVAL;
parm = nla_data(tb[TCA_TUNNEL_KEY_PARMS]);
exists = tcf_hash_check(tn, parm->index, a, bind);
if (exists && bind)
return 0;
switch (parm->t_action) {
case TCA_TUNNEL_KEY_ACT_RELEASE:
break;
case TCA_TUNNEL_KEY_ACT_SET:
if (!tb[TCA_TUNNEL_KEY_ENC_KEY_ID]) {
ret = -EINVAL;
goto err_out;
}
key_id = key32_to_tunnel_id(nla_get_be32(tb[TCA_TUNNEL_KEY_ENC_KEY_ID]));
if (tb[TCA_TUNNEL_KEY_ENC_DST_PORT])
dst_port = nla_get_be16(tb[TCA_TUNNEL_KEY_ENC_DST_PORT]);
if (tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC] &&
tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]) {
__be32 saddr;
__be32 daddr;
saddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_SRC]);
daddr = nla_get_in_addr(tb[TCA_TUNNEL_KEY_ENC_IPV4_DST]);
metadata = __ip_tun_set_dst(saddr, daddr, 0, 0,
dst_port, TUNNEL_KEY,
key_id, 0);
} else if (tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC] &&
tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]) {
struct in6_addr saddr;
struct in6_addr daddr;
saddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_SRC]);
daddr = nla_get_in6_addr(tb[TCA_TUNNEL_KEY_ENC_IPV6_DST]);
metadata = __ipv6_tun_set_dst(&saddr, &daddr, 0, 0, 0,
dst_port, TUNNEL_KEY,
key_id, 0);
}
if (!metadata) {
ret = -EINVAL;
goto err_out;
}
metadata->u.tun_info.mode |= IP_TUNNEL_INFO_TX;
break;
default:
goto err_out;
}
if (!exists) {
ret = tcf_hash_create(tn, parm->index, est, a,
&act_tunnel_key_ops, bind, true);
if (ret)
return ret;
ret = ACT_P_CREATED;
} else {
tcf_hash_release(*a, bind);
if (!ovr)
return -EEXIST;
}
t = to_tunnel_key(*a);
ASSERT_RTNL();
params_new = kzalloc(sizeof(*params_new), GFP_KERNEL);
if (unlikely(!params_new)) {
if (ret == ACT_P_CREATED)
tcf_hash_release(*a, bind);
return -ENOMEM;
}
params_old = rtnl_dereference(t->params);
params_new->action = parm->action;
params_new->tcft_action = parm->t_action;
params_new->tcft_enc_metadata = metadata;
rcu_assign_pointer(t->params, params_new);
if (params_old)
kfree_rcu(params_old, rcu);
if (ret == ACT_P_CREATED)
tcf_hash_insert(tn, *a);
return ret;
err_out:
if (exists)
tcf_hash_release(*a, bind);
return ret;
}
static void tunnel_key_release(struct tc_action *a, int bind)
{
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
params = rcu_dereference_protected(t->params, 1);
if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET)
dst_release(&params->tcft_enc_metadata->dst);
kfree_rcu(params, rcu);
}
static int tunnel_key_dump_addresses(struct sk_buff *skb,
const struct ip_tunnel_info *info)
{
unsigned short family = ip_tunnel_info_af(info);
if (family == AF_INET) {
__be32 saddr = info->key.u.ipv4.src;
__be32 daddr = info->key.u.ipv4.dst;
if (!nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_SRC, saddr) &&
!nla_put_in_addr(skb, TCA_TUNNEL_KEY_ENC_IPV4_DST, daddr))
return 0;
}
if (family == AF_INET6) {
const struct in6_addr *saddr6 = &info->key.u.ipv6.src;
const struct in6_addr *daddr6 = &info->key.u.ipv6.dst;
if (!nla_put_in6_addr(skb,
TCA_TUNNEL_KEY_ENC_IPV6_SRC, saddr6) &&
!nla_put_in6_addr(skb,
TCA_TUNNEL_KEY_ENC_IPV6_DST, daddr6))
return 0;
}
return -EINVAL;
}
static int tunnel_key_dump(struct sk_buff *skb, struct tc_action *a,
int bind, int ref)
{
unsigned char *b = skb_tail_pointer(skb);
struct tcf_tunnel_key *t = to_tunnel_key(a);
struct tcf_tunnel_key_params *params;
struct tc_tunnel_key opt = {
.index = t->tcf_index,
.refcnt = t->tcf_refcnt - ref,
.bindcnt = t->tcf_bindcnt - bind,
};
struct tcf_t tm;
params = rtnl_dereference(t->params);
opt.t_action = params->tcft_action;
opt.action = params->action;
if (nla_put(skb, TCA_TUNNEL_KEY_PARMS, sizeof(opt), &opt))
goto nla_put_failure;
if (params->tcft_action == TCA_TUNNEL_KEY_ACT_SET) {
struct ip_tunnel_key *key =
&params->tcft_enc_metadata->u.tun_info.key;
__be32 key_id = tunnel_id_to_key32(key->tun_id);
if (nla_put_be32(skb, TCA_TUNNEL_KEY_ENC_KEY_ID, key_id) ||
tunnel_key_dump_addresses(skb,
&params->tcft_enc_metadata->u.tun_info) ||
nla_put_be16(skb, TCA_TUNNEL_KEY_ENC_DST_PORT, key->tp_dst))
goto nla_put_failure;
}
tcf_tm_dump(&tm, &t->tcf_tm);
if (nla_put_64bit(skb, TCA_TUNNEL_KEY_TM, sizeof(tm),
&tm, TCA_TUNNEL_KEY_PAD))
goto nla_put_failure;
return skb->len;
nla_put_failure:
nlmsg_trim(skb, b);
return -1;
}
static int tunnel_key_walker(struct net *net, struct sk_buff *skb,
struct netlink_callback *cb, int type,
const struct tc_action_ops *ops)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tcf_generic_walker(tn, skb, cb, type, ops);
}
static int tunnel_key_search(struct net *net, struct tc_action **a, u32 index)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tcf_hash_search(tn, a, index);
}
static struct tc_action_ops act_tunnel_key_ops = {
.kind = "tunnel_key",
.type = TCA_ACT_TUNNEL_KEY,
.owner = THIS_MODULE,
.act = tunnel_key_act,
.dump = tunnel_key_dump,
.init = tunnel_key_init,
.cleanup = tunnel_key_release,
.walk = tunnel_key_walker,
.lookup = tunnel_key_search,
.size = sizeof(struct tcf_tunnel_key),
};
static __net_init int tunnel_key_init_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
return tc_action_net_init(tn, &act_tunnel_key_ops, TUNNEL_KEY_TAB_MASK);
}
static void __net_exit tunnel_key_exit_net(struct net *net)
{
struct tc_action_net *tn = net_generic(net, tunnel_key_net_id);
tc_action_net_exit(tn);
}
static struct pernet_operations tunnel_key_net_ops = {
.init = tunnel_key_init_net,
.exit = tunnel_key_exit_net,
.id = &tunnel_key_net_id,
.size = sizeof(struct tc_action_net),
};
static int __init tunnel_key_init_module(void)
{
return tcf_register_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
}
static void __exit tunnel_key_cleanup_module(void)
{
tcf_unregister_action(&act_tunnel_key_ops, &tunnel_key_net_ops);
}
module_init(tunnel_key_init_module);
module_exit(tunnel_key_cleanup_module);
MODULE_AUTHOR("Amir Vadai <amir@vadai.me>");
MODULE_DESCRIPTION("ip tunnel manipulation actions");
MODULE_LICENSE("GPL v2");