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filter: refactor common filter attach code into __sk_attach_prog

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Both sk_attach_filter() and sk_attach_bpf() are setting up sk_filter,
charging skmem and attaching it to the socket after we got the eBPF
prog up and ready. Lets refactor that into a common helper.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Daniel Borkmann 2015-03-02 12:25:51 +01:00 committed by David S. Miller
parent 70c836a4d1
commit 49b31e576a
1 changed files with 33 additions and 38 deletions
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71
net/core/filter.c
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@ -1019,6 +1019,32 @@ void bpf_prog_destroy(struct bpf_prog *fp)
}
EXPORT_SYMBOL_GPL(bpf_prog_destroy);
static int __sk_attach_prog(struct bpf_prog *prog, struct sock *sk)
{
struct sk_filter *fp, *old_fp;
fp = kmalloc(sizeof(*fp), GFP_KERNEL);
if (!fp)
return -ENOMEM;
fp->prog = prog;
atomic_set(&fp->refcnt, 0);
if (!sk_filter_charge(sk, fp)) {
kfree(fp);
return -ENOMEM;
}
old_fp = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
if (old_fp)
sk_filter_uncharge(sk, old_fp);
return 0;
}
/**
* sk_attach_filter - attach a socket filter
* @fprog: the filter program
@ -1031,7 +1057,6 @@ EXPORT_SYMBOL_GPL(bpf_prog_destroy);
*/
int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
{
struct sk_filter *fp, *old_fp;
unsigned int fsize = bpf_classic_proglen(fprog);
unsigned int bpf_fsize = bpf_prog_size(fprog->len);
struct bpf_prog *prog;
@ -1068,26 +1093,11 @@ int sk_attach_filter(struct sock_fprog *fprog, struct sock *sk)
if (IS_ERR(prog))
return PTR_ERR(prog);
fp = kmalloc(sizeof(*fp), GFP_KERNEL);
if (!fp) {
err = __sk_attach_prog(prog, sk);
if (err < 0) {
__bpf_prog_release(prog);
return -ENOMEM;
return err;
}
fp->prog = prog;
atomic_set(&fp->refcnt, 0);
if (!sk_filter_charge(sk, fp)) {
__sk_filter_release(fp);
return -ENOMEM;
}
old_fp = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
if (old_fp)
sk_filter_uncharge(sk, old_fp);
return 0;
}
@ -1095,8 +1105,8 @@ EXPORT_SYMBOL_GPL(sk_attach_filter);
int sk_attach_bpf(u32 ufd, struct sock *sk)
{
struct sk_filter *fp, *old_fp;
struct bpf_prog *prog;
int err;
if (sock_flag(sk, SOCK_FILTER_LOCKED))
return -EPERM;
@ -1110,27 +1120,12 @@ int sk_attach_bpf(u32 ufd, struct sock *sk)
return -EINVAL;
}
fp = kmalloc(sizeof(*fp), GFP_KERNEL);
if (!fp) {
err = __sk_attach_prog(prog, sk);
if (err < 0) {
bpf_prog_put(prog);
return -ENOMEM;
return err;
}
fp->prog = prog;
atomic_set(&fp->refcnt, 0);
if (!sk_filter_charge(sk, fp)) {
__sk_filter_release(fp);
return -ENOMEM;
}
old_fp = rcu_dereference_protected(sk->sk_filter,
sock_owned_by_user(sk));
rcu_assign_pointer(sk->sk_filter, fp);
if (old_fp)
sk_filter_uncharge(sk, old_fp);
return 0;
}