net_sched: use idr to allocate bpf filter handles

Instead of calling cls_bpf_get() in a loop to find
a unused handle, just switch to idr API to allocate
new handles.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Chris Mi <chrism@mellanox.com>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2017-09-25 10:13:49 -07:00 committed by David S. Miller
parent 8f1975e31d
commit 76cf546c28
1 changed files with 28 additions and 29 deletions

View File

@ -17,6 +17,7 @@
#include <linux/skbuff.h>
#include <linux/filter.h>
#include <linux/bpf.h>
#include <linux/idr.h>
#include <net/rtnetlink.h>
#include <net/pkt_cls.h>
@ -32,7 +33,7 @@ MODULE_DESCRIPTION("TC BPF based classifier");
struct cls_bpf_head {
struct list_head plist;
u32 hgen;
struct idr handle_idr;
struct rcu_head rcu;
};
@ -238,6 +239,7 @@ static int cls_bpf_init(struct tcf_proto *tp)
return -ENOBUFS;
INIT_LIST_HEAD_RCU(&head->plist);
idr_init(&head->handle_idr);
rcu_assign_pointer(tp->root, head);
return 0;
@ -264,6 +266,9 @@ static void cls_bpf_delete_prog_rcu(struct rcu_head *rcu)
static void __cls_bpf_delete(struct tcf_proto *tp, struct cls_bpf_prog *prog)
{
struct cls_bpf_head *head = rtnl_dereference(tp->root);
idr_remove_ext(&head->handle_idr, prog->handle);
cls_bpf_stop_offload(tp, prog);
list_del_rcu(&prog->link);
tcf_unbind_filter(tp, &prog->res);
@ -287,6 +292,7 @@ static void cls_bpf_destroy(struct tcf_proto *tp)
list_for_each_entry_safe(prog, tmp, &head->plist, link)
__cls_bpf_delete(tp, prog);
idr_destroy(&head->handle_idr);
kfree_rcu(head, rcu);
}
@ -421,27 +427,6 @@ static int cls_bpf_set_parms(struct net *net, struct tcf_proto *tp,
return 0;
}
static u32 cls_bpf_grab_new_handle(struct tcf_proto *tp,
struct cls_bpf_head *head)
{
unsigned int i = 0x80000000;
u32 handle;
do {
if (++head->hgen == 0x7FFFFFFF)
head->hgen = 1;
} while (--i > 0 && cls_bpf_get(tp, head->hgen));
if (unlikely(i == 0)) {
pr_err("Insufficient number of handles\n");
handle = 0;
} else {
handle = head->hgen;
}
return handle;
}
static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
struct tcf_proto *tp, unsigned long base,
u32 handle, struct nlattr **tca,
@ -451,6 +436,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
struct cls_bpf_prog *oldprog = *arg;
struct nlattr *tb[TCA_BPF_MAX + 1];
struct cls_bpf_prog *prog;
unsigned long idr_index;
int ret;
if (tca[TCA_OPTIONS] == NULL)
@ -476,21 +462,30 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
}
}
if (handle == 0)
prog->handle = cls_bpf_grab_new_handle(tp, head);
else
if (handle == 0) {
ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,
1, 0x7FFFFFFF, GFP_KERNEL);
if (ret)
goto errout;
prog->handle = idr_index;
} else {
if (!oldprog) {
ret = idr_alloc_ext(&head->handle_idr, prog, &idr_index,
handle, handle + 1, GFP_KERNEL);
if (ret)
goto errout;
}
prog->handle = handle;
if (prog->handle == 0) {
ret = -EINVAL;
goto errout;
}
ret = cls_bpf_set_parms(net, tp, prog, base, tb, tca[TCA_RATE], ovr);
if (ret < 0)
goto errout;
goto errout_idr;
ret = cls_bpf_offload(tp, prog, oldprog);
if (ret) {
if (!oldprog)
idr_remove_ext(&head->handle_idr, prog->handle);
__cls_bpf_delete_prog(prog);
return ret;
}
@ -499,6 +494,7 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
prog->gen_flags |= TCA_CLS_FLAGS_NOT_IN_HW;
if (oldprog) {
idr_replace_ext(&head->handle_idr, prog, handle);
list_replace_rcu(&oldprog->link, &prog->link);
tcf_unbind_filter(tp, &oldprog->res);
call_rcu(&oldprog->rcu, cls_bpf_delete_prog_rcu);
@ -509,6 +505,9 @@ static int cls_bpf_change(struct net *net, struct sk_buff *in_skb,
*arg = prog;
return 0;
errout_idr:
if (!oldprog)
idr_remove_ext(&head->handle_idr, prog->handle);
errout:
tcf_exts_destroy(&prog->exts);
kfree(prog);