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bpf: Add SO_KEEPALIVE and related options to bpf_setsockopt

This patch adds support of SO_KEEPALIVE flag and TCP related options to bpf_setsockopt() routine. This is helpful if we want to enable or tune TCP keepalive for applications which don't do it in the userspace code. v3: - update kernel-doc in uapi (Nikita Vetoshkin <nekto0n@yandex-team.ru>) v4: - update kernel-doc in tools too (Alexei Starovoitov) - add test to selftests (Alexei Starovoitov)

Dmitry Yakunin committed 6 years ago

Commit f9bcf961 parent aad4a0a4 files · +72 −5Browse files

Unified · Split

4 files
  1. include/uapi/linux/bpf.h +5 −2
  2. net/core/filter.c +35 −1
  3. tools/include/uapi/linux/bpf.h +5 −2
  4. tools/testing/selftests/bpf/progs/connect4_prog.c +27 −0
include/uapi/linux/bpf.h+5−2
@@ -1621,10 +1621,13 @@ union bpf_attr { · 1620 unmodified lines
16211621 *
16221622 * * **SOL_SOCKET**, which supports the following *optname*\ s:
16231623 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
1624− * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
1624+ * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
1625+ * **SO_BINDTODEVICE**, **SO_KEEPALIVE**.
16251626 * * **IPPROTO_TCP**, which supports the following *optname*\ s:
16261627 * **TCP_CONGESTION**, **TCP_BPF_IW**,
1627− * **TCP_BPF_SNDCWND_CLAMP**.
1628+ * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
1629+ * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
1630+ * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**.
16281631 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
16291632 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
16301633 * Return
net/core/filter.c+35−1
@@ -4289,10 +4289,10 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, · 4288 unmodified lines
42894289 char *optval, int optlen, u32 flags)
42904290 {
42914291 char devname[IFNAMSIZ];
4292+ int val, valbool;
42924293 struct net *net;
42934294 int ifindex;
42944295 int ret = 0;
4295− int val;
42964296
42974297 if (!sk_fullsock(sk))
42984298 return -EINVAL;
@@ -4303,6 +4303,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, · 4 unmodified lines
43034303 if (optlen != sizeof(int) && optname != SO_BINDTODEVICE)
43044304 return -EINVAL;
43054305 val = *((int *)optval);
4306+ valbool = val ? 1 : 0;
43064307
43074308 /* Only some socketops are supported */
43084309 switch (optname) {
@@ -4361,6 +4362,11 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, · 52 unmodified lines
43614362 }
43624363 ret = sock_bindtoindex(sk, ifindex, false);
43634364 break;
4365+ case SO_KEEPALIVE:
4366+ if (sk->sk_prot->keepalive)
4367+ sk->sk_prot->keepalive(sk, valbool);
4368+ sock_valbool_flag(sk, SOCK_KEEPOPEN, valbool);
4369+ break;
43644370 default:
43654371 ret = -EINVAL;
43664372 }
@@ -4421,6 +4427,7 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, · 54 unmodified lines
44214427 ret = tcp_set_congestion_control(sk, name, false,
44224428 reinit, true);
44234429 } else {
4430+ struct inet_connection_sock *icsk = inet_csk(sk);
44244431 struct tcp_sock *tp = tcp_sk(sk);
44254432
44264433 if (optlen != sizeof(int))
@@ -4449,6 +4456,33 @@ static int _bpf_setsockopt(struct sock *sk, int level, int optname, · 22 unmodified lines
44494456 else
44504457 tp->save_syn = val;
44514458 break;
4459+ case TCP_KEEPIDLE:
4460+ ret = tcp_sock_set_keepidle_locked(sk, val);
4461+ break;
4462+ case TCP_KEEPINTVL:
4463+ if (val < 1 || val > MAX_TCP_KEEPINTVL)
4464+ ret = -EINVAL;
4465+ else
4466+ tp->keepalive_intvl = val * HZ;
4467+ break;
4468+ case TCP_KEEPCNT:
4469+ if (val < 1 || val > MAX_TCP_KEEPCNT)
4470+ ret = -EINVAL;
4471+ else
4472+ tp->keepalive_probes = val;
4473+ break;
4474+ case TCP_SYNCNT:
4475+ if (val < 1 || val > MAX_TCP_SYNCNT)
4476+ ret = -EINVAL;
4477+ else
4478+ icsk->icsk_syn_retries = val;
4479+ break;
4480+ case TCP_USER_TIMEOUT:
4481+ if (val < 0)
4482+ ret = -EINVAL;
4483+ else
4484+ icsk->icsk_user_timeout = val;
4485+ break;
44524486 default:
44534487 ret = -EINVAL;
44544488 }
tools/include/uapi/linux/bpf.h+5−2
@@ -1621,10 +1621,13 @@ union bpf_attr { · 1620 unmodified lines
16211621 *
16221622 * * **SOL_SOCKET**, which supports the following *optname*\ s:
16231623 * **SO_RCVBUF**, **SO_SNDBUF**, **SO_MAX_PACING_RATE**,
1624− * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**.
1624+ * **SO_PRIORITY**, **SO_RCVLOWAT**, **SO_MARK**,
1625+ * **SO_BINDTODEVICE**, **SO_KEEPALIVE**.
16251626 * * **IPPROTO_TCP**, which supports the following *optname*\ s:
16261627 * **TCP_CONGESTION**, **TCP_BPF_IW**,
1627− * **TCP_BPF_SNDCWND_CLAMP**.
1628+ * **TCP_BPF_SNDCWND_CLAMP**, **TCP_SAVE_SYN**,
1629+ * **TCP_KEEPIDLE**, **TCP_KEEPINTVL**, **TCP_KEEPCNT**,
1630+ * **TCP_SYNCNT**, **TCP_USER_TIMEOUT**.
16281631 * * **IPPROTO_IP**, which supports *optname* **IP_TOS**.
16291632 * * **IPPROTO_IPV6**, which supports *optname* **IPV6_TCLASS**.
16301633 * Return
tools/testing/selftests/bpf/progs/connect4_prog.c+27−0
@@ -104,6 +104,30 @@ static __inline int bind_to_device(struct bpf_sock_addr *ctx) · 103 unmodified lines
104104 return 0;
105105 }
106106
107+static __inline int set_keepalive(struct bpf_sock_addr *ctx)
108+{
109+ int zero = 0, one = 1;
110+
111+ if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one)))
112+ return 1;
113+ if (ctx->type == SOCK_STREAM) {
114+ if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPIDLE, &one, sizeof(one)))
115+ return 1;
116+ if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPINTVL, &one, sizeof(one)))
117+ return 1;
118+ if (bpf_setsockopt(ctx, SOL_TCP, TCP_KEEPCNT, &one, sizeof(one)))
119+ return 1;
120+ if (bpf_setsockopt(ctx, SOL_TCP, TCP_SYNCNT, &one, sizeof(one)))
121+ return 1;
122+ if (bpf_setsockopt(ctx, SOL_TCP, TCP_USER_TIMEOUT, &one, sizeof(one)))
123+ return 1;
124+ }
125+ if (bpf_setsockopt(ctx, SOL_SOCKET, SO_KEEPALIVE, &zero, sizeof(zero)))
126+ return 1;
127+
128+ return 0;
129+}
130+
107131 SEC("cgroup/connect4")
108132 int connect_v4_prog(struct bpf_sock_addr *ctx)
109133 {
@@ -121,6 +145,9 @@ int connect_v4_prog(struct bpf_sock_addr *ctx) · 11 unmodified lines
121145 if (bind_to_device(ctx))
122146 return 0;
123147
148+ if (set_keepalive(ctx))
149+ return 0;
150+
124151 if (ctx->type != SOCK_STREAM && ctx->type != SOCK_DGRAM)
125152 return 0;
126153 else if (ctx->type == SOCK_STREAM)