diff mbox series

[v4,bpf-next,1/2] bpf: Adds support for setting window clamp

Message ID 20201202213152.435886-2-prankgup@fb.com (mailing list archive)
State Accepted
Delegated to: BPF
Headers show
Series Add support to set window_clamp from bpf setsockops | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 1527 this patch: 1527
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 53 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 1513 this patch: 1513
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Prankur gupta Dec. 2, 2020, 9:31 p.m. UTC 
Adds a new bpf_setsockopt for TCP sockets, TCP_BPF_WINDOW_CLAMP,
which sets the maximum receiver window size. It will be useful for
limiting receiver window based on RTT.

Signed-off-by: Prankur gupta <prankgup@fb.com>
---
 include/net/tcp.h |  1 +
 net/core/filter.c |  3 +++
 net/ipv4/tcp.c    | 25 ++++++++++++++++---------
 3 files changed, 20 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/include/net/tcp.h b/include/net/tcp.h
index 4aba0f069b05..347a76f176b4 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -406,6 +406,7 @@  void tcp_syn_ack_timeout(const struct request_sock *req);
 int tcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, int nonblock,
 		int flags, int *addr_len);
 int tcp_set_rcvlowat(struct sock *sk, int val);
+int tcp_set_window_clamp(struct sock *sk, int val);
 void tcp_data_ready(struct sock *sk);
 #ifdef CONFIG_MMU
 int tcp_mmap(struct file *file, struct socket *sock,
diff --git a/net/core/filter.c b/net/core/filter.c
index 2ca5eecebacf..6273883dfeb2 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -4910,6 +4910,9 @@  static int _bpf_setsockopt(struct sock *sk, int level, int optname,
 				tp->notsent_lowat = val;
 				sk->sk_write_space(sk);
 				break;
+			case TCP_WINDOW_CLAMP:
+				ret = tcp_set_window_clamp(sk, val);
+				break;
 			default:
 				ret = -EINVAL;
 			}
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index b2bc3d7fe9e8..17379f6dd955 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3022,6 +3022,21 @@  int tcp_sock_set_keepcnt(struct sock *sk, int val)
 }
 EXPORT_SYMBOL(tcp_sock_set_keepcnt);
 
+int tcp_set_window_clamp(struct sock *sk, int val)
+{
+	struct tcp_sock *tp = tcp_sk(sk);
+
+	if (!val) {
+		if (sk->sk_state != TCP_CLOSE)
+			return -EINVAL;
+		tp->window_clamp = 0;
+	} else {
+		tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
+			SOCK_MIN_RCVBUF / 2 : val;
+	}
+	return 0;
+}
+
 /*
  *	Socket option code for TCP.
  */
@@ -3235,15 +3250,7 @@  static int do_tcp_setsockopt(struct sock *sk, int level, int optname,
 		break;
 
 	case TCP_WINDOW_CLAMP:
-		if (!val) {
-			if (sk->sk_state != TCP_CLOSE) {
-				err = -EINVAL;
-				break;
-			}
-			tp->window_clamp = 0;
-		} else
-			tp->window_clamp = val < SOCK_MIN_RCVBUF / 2 ?
-						SOCK_MIN_RCVBUF / 2 : val;
+		err = tcp_set_window_clamp(sk, val);
 		break;
 
 	case TCP_QUICKACK: