diff mbox series

[bpf-next,v4,1/4] tcp: introduce tcp_read_skb()

Message ID 20220615162014.89193-2-xiyou.wangcong@gmail.com (mailing list archive)
State Accepted
Commit 04919bed948dc22a0032a9da867b7dcb8aece4ca
Delegated to: BPF
Headers show
Series sockmap: some performance optimizations | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1073 this patch: 1073
netdev/cc_maintainers warning 11 maintainers not CCed: songliubraving@fb.com ast@kernel.org pabeni@redhat.com kuba@kernel.org davem@davemloft.net yoshfuji@linux-ipv6.org yhs@fb.com kafai@fb.com dsahern@kernel.org andrii@kernel.org kpsingh@kernel.org
netdev/build_clang success Errors and warnings before: 129 this patch: 129
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 1078 this patch: 1078
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 61 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for Kernel LATEST on ubuntu-latest with gcc
bpf/vmtest-bpf-next-VM_Test-2 success Logs for Kernel LATEST on ubuntu-latest with llvm-15
bpf/vmtest-bpf-next-VM_Test-3 success Logs for Kernel LATEST on z15 with gcc

Commit Message

Cong Wang June 15, 2022, 4:20 p.m. UTC 
From: Cong Wang <cong.wang@bytedance.com>

This patch inroduces tcp_read_skb() based on tcp_read_sock(),
a preparation for the next patch which actually introduces
a new sock ops.

TCP is special here, because it has tcp_read_sock() which is
mainly used by splice(). tcp_read_sock() supports partial read
and arbitrary offset, neither of them is needed for sockmap.

Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
---
 include/net/tcp.h |  2 ++
 net/ipv4/tcp.c    | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 49 insertions(+)

Comments

Eric Dumazet June 16, 2022, 6:25 a.m. UTC | #1 
On Wed, Jun 15, 2022 at 9:20 AM Cong Wang <xiyou.wangcong@gmail.com> wrote:
>
> From: Cong Wang <cong.wang@bytedance.com>
>
> This patch inroduces tcp_read_skb() based on tcp_read_sock(),
> a preparation for the next patch which actually introduces
> a new sock ops.
>
> TCP is special here, because it has tcp_read_sock() which is
> mainly used by splice(). tcp_read_sock() supports partial read
> and arbitrary offset, neither of them is needed for sockmap.
>
> Cc: Eric Dumazet <edumazet@google.com>
> Cc: John Fastabend <john.fastabend@gmail.com>
> Cc: Daniel Borkmann <daniel@iogearbox.net>
> Cc: Jakub Sitnicki <jakub@cloudflare.com>
> Signed-off-by: Cong Wang <cong.wang@bytedance.com>
> ---

Reviewed-by: Eric Dumazet <edumazet@google.com>
diff mbox series

Patch

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 1e99f5c61f84..878544d0f8f9 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -669,6 +669,8 @@  void tcp_get_info(struct sock *, struct tcp_info *);
 /* Read 'sendfile()'-style from a TCP socket */
 int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 		  sk_read_actor_t recv_actor);
+int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
+		 sk_read_actor_t recv_actor);
 
 void tcp_initialize_rcv_mss(struct sock *sk);
 
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 9984d23a7f3e..e4adbdb0a5c4 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1709,6 +1709,53 @@  int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
 }
 EXPORT_SYMBOL(tcp_read_sock);
 
+int tcp_read_skb(struct sock *sk, read_descriptor_t *desc,
+		 sk_read_actor_t recv_actor)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+	u32 seq = tp->copied_seq;
+	struct sk_buff *skb;
+	int copied = 0;
+	u32 offset;
+
+	if (sk->sk_state == TCP_LISTEN)
+		return -ENOTCONN;
+
+	while ((skb = tcp_recv_skb(sk, seq, &offset)) != NULL) {
+		int used;
+
+		__skb_unlink(skb, &sk->sk_receive_queue);
+		used = recv_actor(desc, skb, 0, skb->len);
+		if (used <= 0) {
+			if (!copied)
+				copied = used;
+			break;
+		}
+		seq += used;
+		copied += used;
+
+		if (TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN) {
+			consume_skb(skb);
+			++seq;
+			break;
+		}
+		consume_skb(skb);
+		if (!desc->count)
+			break;
+		WRITE_ONCE(tp->copied_seq, seq);
+	}
+	WRITE_ONCE(tp->copied_seq, seq);
+
+	tcp_rcv_space_adjust(sk);
+
+	/* Clean up data we have read: This will do ACK frames. */
+	if (copied > 0)
+		tcp_cleanup_rbuf(sk, copied);
+
+	return copied;
+}
+EXPORT_SYMBOL(tcp_read_skb);
+
 int tcp_peek_len(struct socket *sock)
 {
 	return tcp_inq(sock->sk);