[net-next, v5, 08/11] net: sock: extend SO_TIMESTAMPING for PHC binding

From: Yangbo Lu
Date: Wed Jun 30 2021 - 04:02:01 EST

Since PTP virtual clock support is added, there can be
several PTP virtual clocks based on one PTP physical
clock for timestamping.

This patch is to extend SO_TIMESTAMPING API to support
PHC (PTP Hardware Clock) binding by adding a new flag
SOF_TIMESTAMPING_BIND_PHC. When PTP virtual clocks are
in use, user space can configure to bind one for
timestamping, but PTP physical clock is not supported
and not needed to bind.

This patch is preparation for timestamp conversion from
raw timestamp to a specific PTP virtual clock time in
core net.

Signed-off-by: Yangbo Lu <yangbo.lu@xxxxxxx>
---
Changes for v3:
- Added this patch.
Changes for v4:
- Passed so_timestamping for sock_set_timestamping.
Changes for v5:
- Fixed build.
---
include/net/sock.h | 8 +++-
include/uapi/linux/net_tstamp.h | 17 ++++++++-
net/core/sock.c | 65 +++++++++++++++++++++++++++++++--
net/ethtool/common.c | 1 +
net/mptcp/sockopt.c | 23 +++++++++---
5 files changed, 101 insertions(+), 13 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 8bdd80027ffb..f23cb259b0e2 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -316,7 +316,9 @@ struct bpf_local_storage;
* @sk_timer: sock cleanup timer
* @sk_stamp: time stamp of last packet received
* @sk_stamp_seq: lock for accessing sk_stamp on 32 bit architectures only
- * @sk_tsflags: SO_TIMESTAMPING socket options
+ * @sk_tsflags: SO_TIMESTAMPING flags
+ * @sk_bind_phc: SO_TIMESTAMPING bind PHC index of PTP virtual clock
+ * for timestamping
* @sk_tskey: counter to disambiguate concurrent tstamp requests
* @sk_zckey: counter to order MSG_ZEROCOPY notifications
* @sk_socket: Identd and reporting IO signals
@@ -493,6 +495,7 @@ struct sock {
seqlock_t sk_stamp_seq;
#endif
u16 sk_tsflags;
+ int sk_bind_phc;
u8 sk_shutdown;
u32 sk_tskey;
atomic_t sk_zckey;
@@ -2755,7 +2758,8 @@ void sock_def_readable(struct sock *sk);

int sock_bindtoindex(struct sock *sk, int ifindex, bool lock_sk);
void sock_set_timestamp(struct sock *sk, int optname, bool valbool);
-int sock_set_timestamping(struct sock *sk, int optname, int val);
+int sock_set_timestamping(struct sock *sk, int optname,
+ struct so_timestamping timestamping);

void sock_enable_timestamps(struct sock *sk);
void sock_no_linger(struct sock *sk);
diff --git a/include/uapi/linux/net_tstamp.h b/include/uapi/linux/net_tstamp.h
index 7ed0b3d1c00a..fcc61c73a666 100644
--- a/include/uapi/linux/net_tstamp.h
+++ b/include/uapi/linux/net_tstamp.h
@@ -13,7 +13,7 @@
#include <linux/types.h>
#include <linux/socket.h> /* for SO_TIMESTAMPING */

-/* SO_TIMESTAMPING gets an integer bit field comprised of these values */
+/* SO_TIMESTAMPING flags */
enum {
SOF_TIMESTAMPING_TX_HARDWARE = (1<<0),
SOF_TIMESTAMPING_TX_SOFTWARE = (1<<1),
@@ -30,8 +30,9 @@ enum {
SOF_TIMESTAMPING_OPT_STATS = (1<<12),
SOF_TIMESTAMPING_OPT_PKTINFO = (1<<13),
SOF_TIMESTAMPING_OPT_TX_SWHW = (1<<14),
+ SOF_TIMESTAMPING_BIND_PHC = (1 << 15),

- SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_OPT_TX_SWHW,
+ SOF_TIMESTAMPING_LAST = SOF_TIMESTAMPING_BIND_PHC,
SOF_TIMESTAMPING_MASK = (SOF_TIMESTAMPING_LAST - 1) |
SOF_TIMESTAMPING_LAST
};
@@ -46,6 +47,18 @@ enum {
SOF_TIMESTAMPING_TX_SCHED | \
SOF_TIMESTAMPING_TX_ACK)

+/**
+ * struct so_timestamping - SO_TIMESTAMPING parameter
+ *
+ * @flags: SO_TIMESTAMPING flags
+ * @bind_phc: Index of PTP virtual clock bound to sock. This is available
+ * if flag SOF_TIMESTAMPING_BIND_PHC is set.
+ */
+struct so_timestamping {
+ int flags;
+ int bind_phc;
+};
+
/**
* struct hwtstamp_config - %SIOCGHWTSTAMP and %SIOCSHWTSTAMP parameter
*
diff --git a/net/core/sock.c b/net/core/sock.c
index ba1c0f75cd45..06bba0e3c207 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -139,6 +139,8 @@
#include <net/tcp.h>
#include <net/busy_poll.h>

+#include <linux/ethtool.h>
+
static DEFINE_MUTEX(proto_list_mutex);
static LIST_HEAD(proto_list);

@@ -810,8 +812,47 @@ void sock_set_timestamp(struct sock *sk, int optname, bool valbool)
}
}

-int sock_set_timestamping(struct sock *sk, int optname, int val)
+static int sock_timestamping_bind_phc(struct sock *sk, int phc_index)
{
+ struct net *net = sock_net(sk);
+ struct net_device *dev = NULL;
+ bool match = false;
+ int *vclock_index;
+ int i, num;
+
+ if (sk->sk_bound_dev_if)
+ dev = dev_get_by_index(net, sk->sk_bound_dev_if);
+
+ if (!dev) {
+ pr_err("%s: sock not bind to device\n", __func__);
+ return -EOPNOTSUPP;
+ }
+
+ num = ethtool_get_phc_vclocks(dev, &vclock_index);
+ for (i = 0; i < num; i++) {
+ if (*(vclock_index + i) == phc_index) {
+ match = true;
+ break;
+ }
+ }
+
+ if (num > 0)
+ kfree(vclock_index);
+
+ if (!match)
+ return -EINVAL;
+
+ sk->sk_bind_phc = phc_index;
+
+ return 0;
+}
+
+int sock_set_timestamping(struct sock *sk, int optname,
+ struct so_timestamping timestamping)
+{
+ int val = timestamping.flags;
+ int ret;
+
if (val & ~SOF_TIMESTAMPING_MASK)
return -EINVAL;

@@ -832,6 +873,12 @@ int sock_set_timestamping(struct sock *sk, int optname, int val)
!(val & SOF_TIMESTAMPING_OPT_TSONLY))
return -EINVAL;

+ if (val & SOF_TIMESTAMPING_BIND_PHC) {
+ ret = sock_timestamping_bind_phc(sk, timestamping.bind_phc);
+ if (ret)
+ return ret;
+ }
+
sk->sk_tsflags = val;
sock_valbool_flag(sk, SOCK_TSTAMP_NEW, optname == SO_TIMESTAMPING_NEW);

@@ -907,6 +954,7 @@ EXPORT_SYMBOL(sock_set_mark);
int sock_setsockopt(struct socket *sock, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
+ struct so_timestamping timestamping;
struct sock_txtime sk_txtime;
struct sock *sk = sock->sk;
int val;
@@ -1073,7 +1121,15 @@ int sock_setsockopt(struct socket *sock, int level, int optname,

case SO_TIMESTAMPING_NEW:
case SO_TIMESTAMPING_OLD:
- ret = sock_set_timestamping(sk, optname, val);
+ if (optlen == sizeof(timestamping)) {
+ if (copy_from_sockptr(&timestamping, optval,
+ sizeof(timestamping)))
+ return -EFAULT;
+ } else {
+ memset(&timestamping, 0, sizeof(timestamping));
+ timestamping.flags = val;
+ }
+ ret = sock_set_timestamping(sk, optname, timestamping);
break;

case SO_RCVLOWAT:
@@ -1348,6 +1404,7 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
struct __kernel_old_timeval tm;
struct __kernel_sock_timeval stm;
struct sock_txtime txtime;
+ struct so_timestamping timestamping;
} v;

int lv = sizeof(int);
@@ -1451,7 +1508,9 @@ int sock_getsockopt(struct socket *sock, int level, int optname,
break;

case SO_TIMESTAMPING_OLD:
- v.val = sk->sk_tsflags;
+ lv = sizeof(v.timestamping);
+ v.timestamping.flags = sk->sk_tsflags;
+ v.timestamping.bind_phc = sk->sk_bind_phc;
break;

case SO_RCVTIMEO_OLD:
diff --git a/net/ethtool/common.c b/net/ethtool/common.c
index 798231b07676..c63e0739dc6a 100644
--- a/net/ethtool/common.c
+++ b/net/ethtool/common.c
@@ -398,6 +398,7 @@ const char sof_timestamping_names[][ETH_GSTRING_LEN] = {
[const_ilog2(SOF_TIMESTAMPING_OPT_STATS)] = "option-stats",
[const_ilog2(SOF_TIMESTAMPING_OPT_PKTINFO)] = "option-pktinfo",
[const_ilog2(SOF_TIMESTAMPING_OPT_TX_SWHW)] = "option-tx-swhw",
+ [const_ilog2(SOF_TIMESTAMPING_BIND_PHC)] = "bind-phc",
};
static_assert(ARRAY_SIZE(sof_timestamping_names) == __SOF_TIMESTAMPING_CNT);

diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index ea38cbcd2ad4..8c03afac5ca0 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -207,14 +207,25 @@ static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk,
{
struct mptcp_subflow_context *subflow;
struct sock *sk = (struct sock *)msk;
- int val, ret;
+ struct so_timestamping timestamping;
+ int ret;

- ret = mptcp_get_int_option(msk, optval, optlen, &val);
- if (ret)
- return ret;
+ if (optlen == sizeof(timestamping)) {
+ if (copy_from_sockptr(&timestamping, optval,
+ sizeof(timestamping)))
+ return -EFAULT;
+ } else if (optlen == sizeof(int)) {
+ memset(&timestamping, 0, sizeof(timestamping));
+
+ if (copy_from_sockptr(&timestamping.flags, optval, sizeof(int)))
+ return -EFAULT;
+ } else {
+ return -EINVAL;
+ }

ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname,
- KERNEL_SOCKPTR(&val), sizeof(val));
+ KERNEL_SOCKPTR(&timestamping),
+ sizeof(timestamping));
if (ret)
return ret;

@@ -224,7 +235,7 @@ static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk,
struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
bool slow = lock_sock_fast(ssk);

- sock_set_timestamping(sk, optname, val);
+ sock_set_timestamping(sk, optname, timestamping);
unlock_sock_fast(ssk, slow);
}

--
2.25.1