Support hw SCM_TSTAMP_SND case for bpf timestamping.
Add a new sock_ops callback, BPF_SOCK_OPS_TS_HW_OPT_CB. This
callback will occur at the same timestamping point as the user
space's hardware SCM_TSTAMP_SND. The BPF program can use it to
get the same SCM_TSTAMP_SND timestamp without modifying the
user-space application.
To avoid increase the code complexity, replace SKBTX_HW_TSTAMP
with SKBTX_HW_TSTAMP_NOBPF instead of changing numerous callers
from driver side using SKBTX_HW_TSTAMP. The new definition of
SKBTX_HW_TSTAMP means the combination tests of socket timestamping
and bpf timestamping. After this patch, drivers can work under the
bpf timestamping.
Considering some drivers doesn't assign the skb with hardware
timestamp, this patch do the assignment and then BPF program
can acquire the hwstamp from skb directly.
Signed-off-by: Jason Xing <kerneljasonxing@xxxxxxxxx>
---
include/linux/skbuff.h | 4 +++-
include/uapi/linux/bpf.h | 4 ++++
net/core/skbuff.c | 6 +++---
tools/include/uapi/linux/bpf.h | 4 ++++
4 files changed, 14 insertions(+), 4 deletions(-)
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 76582500c5ea..0b4f1889500d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -470,7 +470,7 @@ struct skb_shared_hwtstamps {
/* Definitions for tx_flags in struct skb_shared_info */
enum {
/* generate hardware time stamp */
- SKBTX_HW_TSTAMP = 1 << 0,
+ SKBTX_HW_TSTAMP_NOBPF = 1 << 0,
/* generate software time stamp when queueing packet to NIC */
SKBTX_SW_TSTAMP = 1 << 1,
@@ -494,6 +494,8 @@ enum {
SKBTX_BPF = 1 << 7,
};
+#define SKBTX_HW_TSTAMP (SKBTX_HW_TSTAMP_NOBPF | SKBTX_BPF)
+
#define SKBTX_ANY_SW_TSTAMP (SKBTX_SW_TSTAMP | \
SKBTX_SCHED_TSTAMP | \
SKBTX_BPF)
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index b3bd92281084..f70edd067edf 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -7043,6 +7043,10 @@ enum {
* to the nic when SK_BPF_CB_TX_TIMESTAMPING
* feature is on.
*/
+ BPF_SOCK_OPS_TS_HW_OPT_CB, /* Called in hardware phase when
+ * SK_BPF_CB_TX_TIMESTAMPING feature
+ * is on.
+ */
};
/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index d80d2137692f..4930c43ee77b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -5547,7 +5547,7 @@ static bool skb_tstamp_tx_report_so_timestamping(struct sk_buff *skb,
case SCM_TSTAMP_SCHED:
return skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP;
case SCM_TSTAMP_SND:
- return skb_shinfo(skb)->tx_flags & (hwts ? SKBTX_HW_TSTAMP :
+ return skb_shinfo(skb)->tx_flags & (hwts ? SKBTX_HW_TSTAMP_NOBPF :
SKBTX_SW_TSTAMP);
case SCM_TSTAMP_ACK:
return TCP_SKB_CB(skb)->txstamp_ack;
@@ -5568,9 +5568,9 @@ static void skb_tstamp_tx_report_bpf_timestamping(struct sk_buff *skb,
op = BPF_SOCK_OPS_TS_SCHED_OPT_CB;
break;
case SCM_TSTAMP_SND:
+ op = hwts ? BPF_SOCK_OPS_TS_HW_OPT_CB : BPF_SOCK_OPS_TS_SW_OPT_CB;
if (hwts)
- return;
- op = BPF_SOCK_OPS_TS_SW_OPT_CB;
+ *skb_hwtstamps(skb) = *hwts;
break;
default:
return;
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 9bd1c7c77b17..7b9652ce7e3c 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -7033,6 +7033,10 @@ enum {
* to the nic when SK_BPF_CB_TX_TIMESTAMPING
* feature is on.
*/
+ BPF_SOCK_OPS_TS_HW_OPT_CB, /* Called in hardware phase when
+ * SK_BPF_CB_TX_TIMESTAMPING feature
+ * is on.
+ */
};
/* List of TCP states. There is a build check in net/ipv4/tcp.c to detect
--
2.43.5
