Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Alexei Starovoitov says:

====================
pull-request: bpf-next 2021-04-01

The following pull-request contains BPF updates for your *net-next* tree.

We've added 68 non-merge commits during the last 7 day(s) which contain
a total of 70 files changed, 2944 insertions(+), 1139 deletions(-).

The main changes are:

1) UDP support for sockmap, from Cong.

2) Verifier merge conflict resolution fix, from Daniel.

3) xsk selftests enhancements, from Maciej.

4) Unstable helpers aka kernel func calling, from Martin.

5) Batches ops for LPM map, from Pedro.

6) Fix race in bpf_get_local_storage, from Yonghong.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 76 insertions, 3 deletions

diff --git a/net/ipv4/udp_bpf.c b/net/ipv4/udp_bpf.c
index 7a94791efc1a..7d5c4ebf42fe 100644
--- a/net/ipv4/udp_bpf.c
+++ b/net/ipv4/udp_bpf.c
@@ -4,6 +4,68 @@
 #include <linux/skmsg.h>
 #include <net/sock.h>
 #include <net/udp.h>
+#include <net/inet_common.h>
+
+#include "udp_impl.h"
+
+static struct proto *udpv6_prot_saved __read_mostly;
+
+static int sk_udp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+			  int noblock, int flags, int *addr_len)
+{
+#if IS_ENABLED(CONFIG_IPV6)
+	if (sk->sk_family == AF_INET6)
+		return udpv6_prot_saved->recvmsg(sk, msg, len, noblock, flags,
+						 addr_len);
+#endif
+	return udp_prot.recvmsg(sk, msg, len, noblock, flags, addr_len);
+}
+
+static int udp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
+			   int nonblock, int flags, int *addr_len)
+{
+	struct sk_psock *psock;
+	int copied, ret;
+
+	if (unlikely(flags & MSG_ERRQUEUE))
+		return inet_recv_error(sk, msg, len, addr_len);
+
+	psock = sk_psock_get(sk);
+	if (unlikely(!psock))
+		return sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+
+	lock_sock(sk);
+	if (sk_psock_queue_empty(psock)) {
+		ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+		goto out;
+	}
+
+msg_bytes_ready:
+	copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
+	if (!copied) {
+		int data, err = 0;
+		long timeo;
+
+		timeo = sock_rcvtimeo(sk, nonblock);
+		data = sk_msg_wait_data(sk, psock, flags, timeo, &err);
+		if (data) {
+			if (!sk_psock_queue_empty(psock))
+				goto msg_bytes_ready;
+			ret = sk_udp_recvmsg(sk, msg, len, nonblock, flags, addr_len);
+			goto out;
+		}
+		if (err) {
+			ret = err;
+			goto out;
+		}
+		copied = -EAGAIN;
+	}
+	ret = copied;
+out:
+	release_sock(sk);
+	sk_psock_put(sk, psock);
+	return ret;
+}
 
 enum {
 	UDP_BPF_IPV4,
@@ -11,7 +73,6 @@ enum {
 	UDP_BPF_NUM_PROTS,
 };
 
-static struct proto *udpv6_prot_saved __read_mostly;
 static DEFINE_SPINLOCK(udpv6_prot_lock);
 static struct proto udp_bpf_prots[UDP_BPF_NUM_PROTS];
 
@@ -20,6 +81,7 @@ static void udp_bpf_rebuild_protos(struct proto *prot, const struct proto *base)
 	*prot        = *base;
 	prot->unhash = sock_map_unhash;
 	prot->close  = sock_map_close;
+	prot->recvmsg = udp_bpf_recvmsg;
 }
 
 static void udp_bpf_check_v6_needs_rebuild(struct proto *ops)
@@ -41,12 +103,23 @@ static int __init udp_bpf_v4_build_proto(void)
 }
 core_initcall(udp_bpf_v4_build_proto);
 
-struct proto *udp_bpf_get_proto(struct sock *sk, struct sk_psock *psock)
+int udp_bpf_update_proto(struct sock *sk, bool restore)
 {
 	int family = sk->sk_family == AF_INET ? UDP_BPF_IPV4 : UDP_BPF_IPV6;
+	struct sk_psock *psock = sk_psock(sk);
+
+	if (restore) {
+		sk->sk_write_space = psock->saved_write_space;
+		/* Pairs with lockless read in sk_clone_lock() */
+		WRITE_ONCE(sk->sk_prot, psock->sk_proto);
+		return 0;
+	}
 
 	if (sk->sk_family == AF_INET6)
 		udp_bpf_check_v6_needs_rebuild(psock->sk_proto);
 
-	return &udp_bpf_prots[family];
+	/* Pairs with lockless read in sk_clone_lock() */
+	WRITE_ONCE(sk->sk_prot, &udp_bpf_prots[family]);
+	return 0;
 }
+EXPORT_SYMBOL_GPL(udp_bpf_update_proto);