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

Alexei Starovoitov says:

====================
pull-request: bpf-next 2017-12-07

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

The main changes are:

1) Detailed documentation of BPF development process from Daniel.

2) Addition of is_fullsock, snd_cwnd and srtt_us fields to bpf_sock_ops
   from Lawrence.

3) Minor follow up for bpf_skb_set_tunnel_key() from William.
====================

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

MAINTAINERS

@@ -2724,12 +2724,16 @@ M:	Alexei Starovoitov <ast@kernel.org>
 M:	Daniel Borkmann <daniel@iogearbox.net>
 L:	netdev@vger.kernel.org
 L:	linux-kernel@vger.kernel.org
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git
 S:	Supported
 F:	arch/x86/net/bpf_jit*
 F:	Documentation/networking/filter.txt
 F:	Documentation/bpf/
 F:	include/linux/bpf*
 F:	include/linux/filter.h
+F:	include/trace/events/bpf.h
+F:	include/trace/events/xdp.h
 F:	include/uapi/linux/bpf*
 F:	include/uapi/linux/filter.h
 F:	kernel/bpf/

include/linux/filter.h

@@ -985,6 +985,7 @@ struct bpf_sock_ops_kern {
 		u32 reply;
 		u32 replylong[4];
 	};
+	u32	is_fullsock;
 };
 
 #endif /* __LINUX_FILTER_H__ */

include/net/tcp.h

@@ -2011,10 +2011,12 @@ static inline int tcp_call_bpf(struct sock *sk, int op)
 	struct bpf_sock_ops_kern sock_ops;
 	int ret;
 
-	if (sk_fullsock(sk))
-		sock_owned_by_me(sk);
-
 	memset(&sock_ops, 0, sizeof(sock_ops));
+	if (sk_fullsock(sk)) {
+		sock_ops.is_fullsock = 1;
+		sock_owned_by_me(sk);
+	}
+
 	sock_ops.sk = sk;
 	sock_ops.op = op;
 

include/uapi/linux/bpf.h

@@ -941,6 +941,12 @@ struct bpf_sock_ops {
 	__u32 local_ip6[4];	/* Stored in network byte order */
 	__u32 remote_port;	/* Stored in network byte order */
 	__u32 local_port;	/* stored in host byte order */
+	__u32 is_fullsock;	/* Some TCP fields are only valid if
+				 * there is a full socket. If not, the
+				 * fields read as zero.
+				 */
+	__u32 snd_cwnd;
+	__u32 srtt_us;		/* Averaged RTT << 3 in usecs */
 };
 
 /* List of known BPF sock_ops operators.

net/core/filter.c

@@ -3013,6 +3013,8 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb,
 	info->key.tun_flags = TUNNEL_KEY | TUNNEL_CSUM | TUNNEL_NOCACHE;
 	if (flags & BPF_F_DONT_FRAGMENT)
 		info->key.tun_flags |= TUNNEL_DONT_FRAGMENT;
+	if (flags & BPF_F_ZERO_CSUM_TX)
+		info->key.tun_flags &= ~TUNNEL_CSUM;
 
 	info->key.tun_id = cpu_to_be64(from->tunnel_id);
 	info->key.tos = from->tunnel_tos;
@@ -3028,9 +3030,6 @@ BPF_CALL_4(bpf_skb_set_tunnel_key, struct sk_buff *, skb,
 		info->key.u.ipv4.dst = cpu_to_be32(from->remote_ipv4);
 	}
 
-	if (flags & BPF_F_ZERO_CSUM_TX)
-		info->key.tun_flags &= ~TUNNEL_CSUM;
-
 	return 0;
 }
 
@@ -4438,6 +4437,42 @@ static u32 sock_ops_convert_ctx_access(enum bpf_access_type type,
 		*insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->dst_reg,
 				      offsetof(struct sock_common, skc_num));
 		break;
+
+	case offsetof(struct bpf_sock_ops, is_fullsock):
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(
+						struct bpf_sock_ops_kern,
+						is_fullsock),
+				      si->dst_reg, si->src_reg,
+				      offsetof(struct bpf_sock_ops_kern,
+					       is_fullsock));
+		break;
+
+/* Helper macro for adding read access to tcp_sock fields. */
+#define SOCK_OPS_GET_TCP32(FIELD_NAME)					      \
+	do {								      \
+		BUILD_BUG_ON(FIELD_SIZEOF(struct tcp_sock, FIELD_NAME) != 4); \
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(			      \
+						struct bpf_sock_ops_kern,     \
+						is_fullsock),		      \
+				      si->dst_reg, si->src_reg,		      \
+				      offsetof(struct bpf_sock_ops_kern,      \
+					       is_fullsock));		      \
+		*insn++ = BPF_JMP_IMM(BPF_JEQ, si->dst_reg, 0, 2);	      \
+		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(			      \
+						struct bpf_sock_ops_kern, sk),\
+				      si->dst_reg, si->src_reg,		      \
+				      offsetof(struct bpf_sock_ops_kern, sk));\
+		*insn++ = BPF_LDX_MEM(BPF_W, si->dst_reg, si->dst_reg,        \
+				      offsetof(struct tcp_sock, FIELD_NAME)); \
+	} while (0)
+
+	case offsetof(struct bpf_sock_ops, snd_cwnd):
+		SOCK_OPS_GET_TCP32(snd_cwnd);
+		break;
+
+	case offsetof(struct bpf_sock_ops, srtt_us):
+		SOCK_OPS_GET_TCP32(srtt_us);
+		break;
 	}
 	return insn - insn_buf;
 }