diff options
| author |  Cong Wang <cong.wang@bytedance.com>
| 2021-07-04 12:02:47 -0700 |
|---|---|---|
| committer |  Alexei Starovoitov <ast@kernel.org>
| 2021-07-15 18:17:50 -0700 |
| commit | c63829182c37c2d6d0608976d15fa61ebebe9e6b (patch) | |
| tree | 99491b47f5fed463f7b5db8a7390f3376fcf523a /net | |
| parent | af_unix: Add a dummy ->close() for sockmap (diff) | |
| download | linux-c63829182c37c2d6d0608976d15fa61ebebe9e6b.tar.gz linux-c63829182c37c2d6d0608976d15fa61ebebe9e6b.tar.bz2 linux-c63829182c37c2d6d0608976d15fa61ebebe9e6b.zip | |
af_unix: Implement ->psock_update_sk_prot()
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
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/sock_map.c | 1 | ||||
| -rw-r--r-- | net/unix/Makefile | 1 | ||||
| -rw-r--r-- | net/unix/af_unix.c | 6 | ||||
| -rw-r--r-- | net/unix/unix_bpf.c | 47 |
4 files changed, 54 insertions, 1 deletions
diff --git a/net/core/sock_map.c b/net/core/sock_map.c index 3c427e7e6df9..ae5fa4338d9c 100644 --- a/net/core/sock_map.c +++ b/net/core/sock_map.c @@ -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, diff --git a/net/unix/Makefile b/net/unix/Makefile index 54e58cc4f945..20491825b4d0 100644 --- a/net/unix/Makefile +++ b/net/unix/Makefile @@ -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 diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 875eeaaddc07..573253c5b5c2 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -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; } diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c new file mode 100644 index 000000000000..b1582a659427 --- /dev/null +++ b/net/unix/unix_bpf.c @@ -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); +} |