Adding support for TCP_NOTSENT_LOWAT sockoption (https://lwn.net/Articles/560082/) in tcpbpf v1->v2: - addressing yhs@ comments. explicitly defining TCP_NOTSENT_LOWAT in selftests if it is not defined in the system Signed-off-by: Nikita V. Shirokov <tehnerd@xxxxxxxxxxx> --- include/uapi/linux/bpf.h | 2 +- net/core/filter.c | 4 ++++ .../selftests/bpf/progs/connect4_prog.c | 19 +++++++++++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index d83561e8cd2c..42d2df799397 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -1698,7 +1698,7 @@ union bpf_attr { * **TCP_CONGESTION**, **TCP_BPF_IW**, * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**, * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**, - * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**. + * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**, **TCP_NOTSENT_LOWAT**. * * **IPPROTO_IP**, which supports *optname* **IP_TOS**. * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**. * Return diff --git a/net/core/filter.c b/net/core/filter.c index 05df73780dd3..5da44b11e1ec 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4827,6 +4827,10 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, else icsk->icsk_user_timeout = val; break; + case TCP_NOTSENT_LOWAT: + tp->notsent_lowat = val; + sk->sk_write_space(sk); + break; default: ret = -EINVAL; } diff --git a/tools/testing/selftests/bpf/progs/connect4_prog.c b/tools/testing/selftests/bpf/progs/connect4_prog.c index b1b2773c0b9d..a943d394fd3a 100644 --- a/tools/testing/selftests/bpf/progs/connect4_prog.c +++ b/tools/testing/selftests/bpf/progs/connect4_prog.c @@ -23,6 +23,10 @@ #define TCP_CA_NAME_MAX 16 #endif +#ifndef TCP_NOTSENT_LOWAT +#define TCP_NOTSENT_LOWAT 25 +#endif + #ifndef IFNAMSIZ #define IFNAMSIZ 16 #endif @@ -128,6 +132,18 @@ static __inline int set_keepalive(struct bpf_sock_addr *ctx) return 0; } +static __inline int set_notsent_lowat(struct bpf_sock_addr *ctx) +{ + int lowat = 65535; + + if (ctx->type == SOCK_STREAM) { + if (bpf_setsockopt(ctx, SOL_TCP, TCP_NOTSENT_LOWAT, &lowat, sizeof(lowat))) + return 1; + } + + return 0; +} + SEC("cgroup/connect4") int connect_v4_prog(struct bpf_sock_addr *ctx) { @@ -148,6 +164,9 @@ int connect_v4_prog(struct bpf_sock_addr *ctx) if (set_keepalive(ctx)) return 0; + if (set_notsent_lowat(ctx)) + return 0; + if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM) return 0; else if (ctx->type == SOCK_STREAM) -- 2.25.1
