[PATCH bpf-next v1 2/5] af_unix: add unix_stream_proto for sockmap

27 Jul 2021

unix_stream_proto is similar to unix_dgram_proto.
Also implement stream related sockmap functions.
Add dgram key words to those dgram specific functions.
Signed-off-by: Jiang Wang jiang.wang@bytedance.com
Reviewed-by: Cong Wang cong.wang@bytedance.com.
---
 include/net/af_unix.h |  8 +++-
 net/core/sock_map.c   |  8 +++-
 net/unix/af_unix.c    | 77 ++++++++++++++++++++++++++++++-----
 net/unix/unix_bpf.c   | 93 +++++++++++++++++++++++++++++++++----------
 4 files changed, 151 insertions(+), 35 deletions(-)

diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index 435a2c3d5..5d04fbf8a 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -84,6 +84,8 @@ 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);
@@ -93,9 +95,11 @@ 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)
diff --git a/net/core/sock_map.c b/net/core/sock_map.c
index ae5fa4338..42f50ea7a 100644
--- a/net/core/sock_map.c
+++ b/net/core/sock_map.c
@@ -517,9 +517,15 @@ static bool sk_is_tcp(const struct sock *sk)
           sk->sk_protocol == IPPROTO_TCP;
 }
+static bool sk_is_unix_stream(const struct sock *sk)
+{
+	return sk->sk_type == SOCK_STREAM &&
+	       sk->sk_protocol == PF_UNIX;
+}
+
 static bool sock_map_redirect_allowed(const struct sock *sk)
 {
-	if (sk_is_tcp(sk))
+	if (sk_is_tcp(sk) || sk_is_unix_stream(sk))
    	return sk->sk_state != TCP_LISTEN;
    else
    	return sk->sk_state == TCP_ESTABLISHED;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 32eeb4a6a..c68d13f61 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -791,17 +791,35 @@ 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_dgram_bpf_update_proto,
+#endif
+};
+
+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_bpf_update_proto,
+	.psock_update_sk_prot	= unix_stream_bpf_update_proto,
 #endif
 };
-static struct sock *unix_create1(struct net *net, struct socket *sock, int kern)
+static struct sock *unix_create1(struct net *net, struct socket *sock, int kern, int type)
 {
    struct sock *sk = NULL;
    struct unix_sock *u;
@@ -810,7 +828,17 @@ 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 != 0) {
+		if (type == SOCK_STREAM)
+			sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_stream_proto, kern);
+		else /*for seqpacket */
+			sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_dgram_proto, kern);
+	} else {
+		if (sock->type == SOCK_STREAM)
+			sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_stream_proto, kern);
+		else
+			sk = sk_alloc(net, PF_UNIX, GFP_KERNEL, &unix_dgram_proto, kern);
+	}
    if (!sk)
    	goto out;
@@ -872,7 +900,7 @@ 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, 0) ? 0 : -ENOMEM;
 }
static int unix_release(struct socket *sock)
@@ -1286,7 +1314,7 @@ 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;
@@ -2214,7 +2242,7 @@ 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)
+	if (sk->sk_prot != &unix_dgram_proto)
    	return sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
    				    flags & ~MSG_DONTWAIT, NULL);
 #endif
@@ -2533,6 +2561,21 @@ 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 socket *sock = sk->sk_socket;
+	struct unix_stream_read_state state = {
+		.recv_actor = unix_stream_read_actor,
+		.socket = sock,
+		.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)
 {
@@ -2544,6 +2587,13 @@ static int unix_stream_recvmsg(struct socket *sock, struct msghdr *msg,
    	.flags = flags
    };
+	struct sock *sk = sock->sk;
+
+#ifdef CONFIG_BPF_SYSCALL
+	if (sk->sk_prot != &unix_stream_proto)
+		return sk->sk_prot->recvmsg(sk, msg, size, flags & MSG_DONTWAIT,
+					    flags & ~MSG_DONTWAIT, NULL);
+#endif
    return unix_stream_read_generic(&state, true);
 }
@@ -2993,7 +3043,13 @@ 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;
@@ -3009,7 +3065,8 @@ 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);
 }
diff --git a/net/unix/unix_bpf.c b/net/unix/unix_bpf.c
index db0cda29f..9067210d3 100644
--- a/net/unix/unix_bpf.c
+++ b/net/unix/unix_bpf.c
@@ -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;
@@ -48,12 +57,12 @@ 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)) {
-		ret = __unix_dgram_recvmsg(sk, msg, len, flags);
+		ret = __unix_recvmsg(sk, msg, len, flags);
    	goto out;
    }
@@ -68,7 +77,7 @@ static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
    	if (data) {
    		if (!sk_psock_queue_empty(psock))
    			goto msg_bytes_ready;
-			ret = __unix_dgram_recvmsg(sk, msg, len, flags);
+			ret = __unix_recvmsg(sk, msg, len, flags);
    		goto out;
    	}
    	copied = -EAGAIN;
@@ -80,30 +89,55 @@ static int unix_dgram_bpf_recvmsg(struct sock *sk, struct msghdr *msg,
    return ret;
 }
-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 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_bpf_recvmsg;
+}
-static void unix_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
+static void unix_stream_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;
+	prot->unhash  = sock_map_unhash;
 }
-static void unix_bpf_check_needs_rebuild(struct proto *ops)
+static void unix_dgram_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);
+	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 (restore) {
    	sk->sk_write_space = psock->saved_write_space;
@@ -111,12 +145,27 @@ 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);
+
 }
-- 
2.20.1


    

2024

2023

2022

2021

2020

2019

2018

2017

[PATCH bpf-next v1 2/5] af_unix: add unix_stream_proto for sockmap