nagai/kernel
3
0
Fork 0
forked from mirrors/linux
Code Pull requests Activity

af_unix: Implement ->psock_update_sk_prot()

Browse source 
Now we can implement unix_bpf_update_proto() to update
sk_prot, especially prot->close().

Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210704190252.11866-7-xiyou.wangcong@gmail.com
This commit is contained in:
Cong Wang 2021-07-04 12:02:47 -07:00 committed by Alexei Starovoitov
parent c7272e15f0
commit c63829182c
6 changed files with 65 additions and 1 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

1
MAINTAINERS
View file

@ -10277,6 +10277,7 @@ F: net/core/skmsg.c
F: net/core/sock_map.c
F: net/ipv4/tcp_bpf.c
F: net/ipv4/udp_bpf.c
F: net/unix/unix_bpf.c
LANDLOCK SECURITY MODULE
M: Mickaël Salaün <mic@digikod.net>

10
include/net/af_unix.h
View file

@ -89,4 +89,14 @@ void unix_sysctl_unregister(struct net *net);
static inline int unix_sysctl_register(struct net *net) { return 0; }
static inline void unix_sysctl_unregister(struct net *net) {}
#endif
#ifdef CONFIG_BPF_SYSCALL
extern struct proto unix_proto;
int unix_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
void __init unix_bpf_build_proto(void);
#else
static inline void __init unix_bpf_build_proto(void)
{}
#endif
#endif

1
net/core/sock_map.c
View file

@ -1517,6 +1517,7 @@ void sock_map_close(struct sock *sk, long timeout)
release_sock(sk);
saved_close(sk, timeout);
}
EXPORT_SYMBOL_GPL(sock_map_close);
static int sock_map_iter_attach_target(struct bpf_prog *prog,
union bpf_iter_link_info *linfo,

1
net/unix/Makefile
View file

@ -7,6 +7,7 @@ obj-$(CONFIG_UNIX) += unix.o
unix-y := af_unix.o garbage.o
unix-$(CONFIG_SYSCTL) += sysctl_net_unix.o
unix-$(CONFIG_BPF_SYSCALL) += unix_bpf.o
obj-$(CONFIG_UNIX_DIAG) += unix_diag.o
unix_diag-y := diag.o

6
net/unix/af_unix.c
View file

@ -788,11 +788,14 @@ static void unix_close(struct sock *sk, long timeout)
*/
}
static struct proto unix_proto = {
struct proto unix_proto = {
.name = "UNIX",
.owner = THIS_MODULE,
.obj_size = sizeof(struct unix_sock),
.close = unix_close,
#ifdef CONFIG_BPF_SYSCALL
.psock_update_sk_prot = unix_bpf_update_proto,
#endif
};
static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
@ -2973,6 +2976,7 @@ static int __init af_unix_init(void)
sock_register(&unix_family_ops);
register_pernet_subsys(&unix_net_ops);
unix_bpf_build_proto();
out:
return rc;
}

47
net/unix/unix_bpf.c Normal file
View file

@ -0,0 +1,47 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (c) 2021 Cong Wang <cong.wang@bytedance.com> */
#include <linux/skmsg.h>
#include <linux/bpf.h>
#include <net/sock.h>
#include <net/af_unix.h>
static struct proto *unix_prot_saved __read_mostly;
static DEFINE_SPINLOCK(unix_prot_lock);
static struct proto unix_bpf_prot;
static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
{
*prot = *base;
prot->close = sock_map_close;
}
static void unix_bpf_check_needs_rebuild(struct proto *ops)
{
if (unlikely(ops != smp_load_acquire(&unix_prot_saved))) {
spin_lock_bh(&unix_prot_lock);
if (likely(ops != unix_prot_saved)) {
unix_bpf_rebuild_protos(&unix_bpf_prot, ops);
smp_store_release(&unix_prot_saved, ops);
}
spin_unlock_bh(&unix_prot_lock);
}
}
int unix_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
{
if (restore) {
sk->sk_write_space = psock->saved_write_space;
WRITE_ONCE(sk->sk_prot, psock->sk_proto);
return 0;
}
unix_bpf_check_needs_rebuild(psock->sk_proto);
WRITE_ONCE(sk->sk_prot, &unix_bpf_prot);
return 0;
}
void __init unix_bpf_build_proto(void)
{
unix_bpf_rebuild_protos(&unix_bpf_prot, &unix_proto);
}