[VOL-4291] Rw-core updates for gRPC migration

Change-Id: I8d5a554409115b29318089671ca4e1ab3fa98810
diff --git a/vendor/github.com/prometheus/procfs/net_softnet.go b/vendor/github.com/prometheus/procfs/net_softnet.go
new file mode 100644
index 0000000..46f12c6
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/net_softnet.go
@@ -0,0 +1,102 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package procfs
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/procfs/internal/util"
+)
+
+// For the proc file format details,
+// See:
+// * Linux 2.6.23 https://elixir.bootlin.com/linux/v2.6.23/source/net/core/dev.c#L2343
+// * Linux 4.17 https://elixir.bootlin.com/linux/v4.17/source/net/core/net-procfs.c#L162
+// and https://elixir.bootlin.com/linux/v4.17/source/include/linux/netdevice.h#L2810.
+
+// SoftnetStat contains a single row of data from /proc/net/softnet_stat
+type SoftnetStat struct {
+	// Number of processed packets
+	Processed uint32
+	// Number of dropped packets
+	Dropped uint32
+	// Number of times processing packets ran out of quota
+	TimeSqueezed uint32
+}
+
+var softNetProcFile = "net/softnet_stat"
+
+// NetSoftnetStat reads data from /proc/net/softnet_stat.
+func (fs FS) NetSoftnetStat() ([]SoftnetStat, error) {
+	b, err := util.ReadFileNoStat(fs.proc.Path(softNetProcFile))
+	if err != nil {
+		return nil, err
+	}
+
+	entries, err := parseSoftnet(bytes.NewReader(b))
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse /proc/net/softnet_stat: %w", err)
+	}
+
+	return entries, nil
+}
+
+func parseSoftnet(r io.Reader) ([]SoftnetStat, error) {
+	const minColumns = 9
+
+	s := bufio.NewScanner(r)
+
+	var stats []SoftnetStat
+	for s.Scan() {
+		columns := strings.Fields(s.Text())
+		width := len(columns)
+
+		if width < minColumns {
+			return nil, fmt.Errorf("%d columns were detected, but at least %d were expected", width, minColumns)
+		}
+
+		// We only parse the first three columns at the moment.
+		us, err := parseHexUint32s(columns[0:3])
+		if err != nil {
+			return nil, err
+		}
+
+		stats = append(stats, SoftnetStat{
+			Processed:    us[0],
+			Dropped:      us[1],
+			TimeSqueezed: us[2],
+		})
+	}
+
+	return stats, nil
+}
+
+func parseHexUint32s(ss []string) ([]uint32, error) {
+	us := make([]uint32, 0, len(ss))
+	for _, s := range ss {
+		u, err := strconv.ParseUint(s, 16, 32)
+		if err != nil {
+			return nil, err
+		}
+
+		us = append(us, uint32(u))
+	}
+
+	return us, nil
+}