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af_unix: Add unix_stream_proto for sockmap

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Previously, sockmap for AF_UNIX protocol only supports
dgram type. This patch add unix stream type support, which
is similar to unix_dgram_proto. To support sockmap, dgram
and stream cannot share the same unix_proto anymore, because
they have different implementations, such as unhash for stream
type (which will remove closed or disconnected sockets from the map),
so rename unix_proto to unix_dgram_proto and add a new
unix_stream_proto.

Also implement stream related sockmap functions.
And add dgram key words to those dgram specific functions.

Signed-off-by: Jiang Wang <jiang.wang@bytedance.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210816190327.2739291-3-jiang.wang@bytedance.com
This commit is contained in:
Jiang Wang 2021-08-16 19:03:21 +00:00 committed by Andrii Nakryiko
parent 77462de14a
commit 94531cfcbe
4 changed files with 148 additions and 37 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

8
include/net/af_unix.h
View file

@ -87,6 +87,8 @@ long unix_outq_len(struct sock *sk);
int __unix_dgram_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
int flags);
int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg, size_t size,
int flags);
#ifdef CONFIG_SYSCTL
int unix_sysctl_register(struct net *net);
void unix_sysctl_unregister(struct net *net);
@ -96,9 +98,11 @@ static inline void unix_sysctl_unregister(struct net *net) {}
#endif
#ifdef CONFIG_BPF_SYSCALL
extern struct proto unix_proto;
extern struct proto unix_dgram_proto;
extern struct proto unix_stream_proto;
int unix_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore);
int unix_stream_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)

1
net/core/sock_map.c
View file

@ -1494,6 +1494,7 @@ void sock_map_unhash(struct sock *sk)
rcu_read_unlock();
saved_unhash(sk);
}
EXPORT_SYMBOL_GPL(sock_map_unhash);
void sock_map_close(struct sock *sk, long timeout)
{

83
net/unix/af_unix.c
View file

@ -798,17 +798,35 @@ static void unix_close(struct sock *sk, long timeout)
*/
}
struct proto unix_proto = {
.name = "UNIX",
static void unix_unhash(struct sock *sk)
{
/* Nothing to do here, unix socket does not need a ->unhash().
* This is merely for sockmap.
*/
}
struct proto unix_dgram_proto = {
.name = "UNIX-DGRAM",
.owner = THIS_MODULE,
.obj_size = sizeof(struct unix_sock),
.close = unix_close,
#ifdef CONFIG_BPF_SYSCALL
.psock_update_sk_prot = unix_bpf_update_proto,
.psock_update_sk_prot = unix_dgram_bpf_update_proto,
#endif
};
static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
struct proto unix_stream_proto = {
.name = "UNIX-STREAM",
.owner = THIS_MODULE,
.obj_size = sizeof(struct unix_sock),
.close = unix_close,
.unhash = unix_unhash,
#ifdef CONFIG_BPF_SYSCALL
.psock_update_sk_prot = unix_stream_bpf_update_proto,
#endif
};
static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, int type)
{
struct sock *sk = NULL;
struct unix_sock *u;
@ -817,7 +835,11 @@ static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
if (atomic_long_read(&unix_nr_socks) > 2 * get_max_files())
goto out;
sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_proto, kern);
if (type == SOCK_STREAM)
sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_stream_proto, kern);
else /*dgram and seqpacket */
sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_dgram_proto, kern);
if (!sk)
goto out;
@ -879,7 +901,7 @@ static int unix_create(struct net *net, struct socket *sock, int protocol,
return -ESOCKTNOSUPPORT;
}
return unix_create1(net, sock, kern) ? 0 : -ENOMEM;
return unix_create1(net, sock, kern, sock->type) ? 0 : -ENOMEM;
}
static int unix_release(struct socket *sock)
@ -1293,7 +1315,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
err = -ENOMEM;
/* create new sock for complete connection */
newsk = unix_create1(sock_net(sk), NULL, 0);
newsk = unix_create1(sock_net(sk), NULL, 0, sock->type);
if (newsk == NULL)
goto out;
@ -2323,8 +2345,10 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg, size_t si
struct sock *sk = sock->sk;
#ifdef CONFIG_BPF_SYSCALL
if (sk->sk_prot != &unix_proto)
return sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
const struct proto *prot = READ_ONCE(sk->sk_prot);
if (prot != &unix_dgram_proto)
return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
flags & ~MSG_DONTWAIT, NULL);
#endif
return __unix_dgram_recvmsg(sk, msg, size, flags);
@ -2728,6 +2752,20 @@ static int unix_stream_read_actor(struct sk_buff *skb,
return ret ?: chunk;
}
int __unix_stream_recvmsg(struct sock *sk, struct msghdr *msg,
size_t size, int flags)
{
struct unix_stream_read_state state = {
.recv_actor = unix_stream_read_actor,
.socket = sk->sk_socket,
.msg = msg,
.size = size,
.flags = flags
};
return unix_stream_read_generic(&state, true);
}
static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
size_t size, int flags)
{
@ -2739,6 +2777,14 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
.flags = flags
};
#ifdef CONFIG_BPF_SYSCALL
struct sock *sk = sock->sk;
const struct proto *prot = READ_ONCE(sk->sk_prot);
if (prot != &unix_stream_proto)
return prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
flags & ~MSG_DONTWAIT, NULL);
#endif
return unix_stream_read_generic(&state, true);
}
@ -2799,7 +2845,9 @@ static int unix_shutdown(struct socket *sock, int mode)
(sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)) {
int peer_mode = 0;
const struct proto *prot = READ_ONCE(other->sk_prot);
prot->unhash(other);
if (mode&RCV_SHUTDOWN)
peer_mode |= SEND_SHUTDOWN;
if (mode&SEND_SHUTDOWN)
@ -2808,10 +2856,12 @@ static int unix_shutdown(struct socket *sock, int mode)
other->sk_shutdown |= peer_mode;
unix_state_unlock(other);
other->sk_state_change(other);
if (peer_mode == SHUTDOWN_MASK)
if (peer_mode == SHUTDOWN_MASK) {
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_HUP);
else if (peer_mode & RCV_SHUTDOWN)
other->sk_state = TCP_CLOSE;
} else if (peer_mode & RCV_SHUTDOWN) {
sk_wake_async(other, SOCK_WAKE_WAITD, POLL_IN);
}
}
if (other)
sock_put(other);
@ -3289,7 +3339,13 @@ static int __init af_unix_init(void)
BUILD_BUG_ON(sizeof(struct unix_skb_parms) > sizeof_field(struct sk_buff, cb));
rc = proto_register(&unix_proto, 1);
rc = proto_register(&unix_dgram_proto, 1);
if (rc != 0) {
pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
goto out;
}
rc = proto_register(&unix_stream_proto, 1);
if (rc != 0) {
pr_crit("%s: Cannot create unix_sock SLAB cache!\n", __func__);
goto out;
@ -3310,7 +3366,8 @@ static int __init af_unix_init(void)
static void __exit af_unix_exit(void)
{
sock_unregister(PF_UNIX);
proto_unregister(&unix_proto);
proto_unregister(&unix_dgram_proto);
proto_unregister(&unix_stream_proto);
unregister_pernet_subsys(&unix_net_ops);
}

93
net/unix/unix_bpf.c
View file

@ -38,9 +38,18 @@ static int unix_msg_wait_data(struct sock *sk, struct sk_psock *psock,
return ret;
}
static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
size_t len, int nonblock, int flags,
int *addr_len)
static int __unix_recvmsg(struct sock *sk, struct msghdr *msg,
size_t len, int flags)
{
if (sk->sk_type == SOCK_DGRAM)
return __unix_dgram_recvmsg(sk, msg, len, flags);
else
return __unix_stream_recvmsg(sk, msg, len, flags);
}
static int unix_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
size_t len, int nonblock, int flags,
int *addr_len)
{
struct unix_sock *u = unix_sk(sk);
struct sk_psock *psock;
@ -48,14 +57,14 @@ static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
psock = sk_psock_get(sk);
if (unlikely(!psock))
return __unix_dgram_recvmsg(sk, msg, len, flags);
return __unix_recvmsg(sk, msg, len, flags);
mutex_lock(&u->iolock);
if (!skb_queue_empty(&sk->sk_receive_queue) &&
sk_psock_queue_empty(psock)) {
mutex_unlock(&u->iolock);
sk_psock_put(sk, psock);
return __unix_dgram_recvmsg(sk, msg, len, flags);
return __unix_recvmsg(sk, msg, len, flags);
}
msg_bytes_ready:
@ -71,7 +80,7 @@ static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
goto msg_bytes_ready;
mutex_unlock(&u->iolock);
sk_psock_put(sk, psock);
return __unix_dgram_recvmsg(sk, msg, len, flags);
return __unix_recvmsg(sk, msg, len, flags);
}
copied = -EAGAIN;
}
@ -80,30 +89,55 @@ static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
return copied;
}
static struct proto *unix_prot_saved __read_mostly;
static DEFINE_SPINLOCK(unix_prot_lock);
static struct proto unix_bpf_prot;
static struct proto *unix_dgram_prot_saved __read_mostly;
static DEFINE_SPINLOCK(unix_dgram_prot_lock);
static struct proto unix_dgram_bpf_prot;
static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
static struct proto *unix_stream_prot_saved __read_mostly;
static DEFINE_SPINLOCK(unix_stream_prot_lock);
static struct proto unix_stream_bpf_prot;
static void unix_dgram_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
{
*prot = *base;
prot->close = sock_map_close;
prot->recvmsg = unix_dgram_bpf_recvmsg;
prot->recvmsg = unix_bpf_recvmsg;
}
static void unix_bpf_check_needs_rebuild(struct proto *ops)
static void unix_stream_bpf_rebuild_protos(struct proto *prot,
const struct proto *base)
{
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);
*prot = *base;
prot->close = sock_map_close;
prot->recvmsg = unix_bpf_recvmsg;
prot->unhash = sock_map_unhash;
}
static void unix_dgram_bpf_check_needs_rebuild(struct proto *ops)
{
if (unlikely(ops != smp_load_acquire(&unix_dgram_prot_saved))) {
spin_lock_bh(&unix_dgram_prot_lock);
if (likely(ops != unix_dgram_prot_saved)) {
unix_dgram_bpf_rebuild_protos(&unix_dgram_bpf_prot, ops);
smp_store_release(&unix_dgram_prot_saved, ops);
}
spin_unlock_bh(&unix_prot_lock);
spin_unlock_bh(&unix_dgram_prot_lock);
}
}
int unix_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
static void unix_stream_bpf_check_needs_rebuild(struct proto *ops)
{
if (unlikely(ops != smp_load_acquire(&unix_stream_prot_saved))) {
spin_lock_bh(&unix_stream_prot_lock);
if (likely(ops != unix_stream_prot_saved)) {
unix_stream_bpf_rebuild_protos(&unix_stream_bpf_prot, ops);
smp_store_release(&unix_stream_prot_saved, ops);
}
spin_unlock_bh(&unix_stream_prot_lock);
}
}
int unix_dgram_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
{
if (sk->sk_type != SOCK_DGRAM)
return -EOPNOTSUPP;
@ -114,12 +148,27 @@ int unix_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
return 0;
}
unix_bpf_check_needs_rebuild(psock->sk_proto);
WRITE_ONCE(sk->sk_prot, &unix_bpf_prot);
unix_dgram_bpf_check_needs_rebuild(psock->sk_proto);
WRITE_ONCE(sk->sk_prot, &unix_dgram_bpf_prot);
return 0;
}
int unix_stream_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_stream_bpf_check_needs_rebuild(psock->sk_proto);
WRITE_ONCE(sk->sk_prot, &unix_stream_bpf_prot);
return 0;
}
void __init unix_bpf_build_proto(void)
{
unix_bpf_rebuild_protos(&unix_bpf_prot, &unix_proto);
unix_dgram_bpf_rebuild_protos(&unix_dgram_bpf_prot, &unix_dgram_proto);
unix_stream_bpf_rebuild_protos(&unix_stream_bpf_prot, &unix_stream_proto);
}