tetragon

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// SPDX-License-Identifier: Apache-2.0
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// Copyright Authors of Tetragon
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package checkprocfs
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import (
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	"path/filepath"
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	"syscall"
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	"github.com/cilium/tetragon/pkg/logger"
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	"github.com/cilium/tetragon/pkg/option"
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	"github.com/sirupsen/logrus"
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)
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// Check tries to determine whether the configured procfs is the host's procfs
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func Check() {
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	path := filepath.Join(option.Config.ProcFS, "1", "ns", "pid")
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	var stat syscall.Stat_t
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	if err := syscall.Stat(path, &stat); err != nil {
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		logger.GetLogger().WithField("path", path).WithError(err).Info("stat failed")
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	}
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	// we compare against the known inode of the host pid namespace:
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	// ...
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	// 	PROC_PID_INIT_INO	= 0xEFFFFFFCU,
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	// ...
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	expectedIno := uint64(0xEFFFFFFC)
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	if stat.Ino != expectedIno {
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		logger.GetLogger().WithFields(logrus.Fields{
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			"path":           path,
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			"inode":          stat.Ino,
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			"expected inode": expectedIno,
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		}).Warn("inode mismatch: procfs does not appear to be host procfs")
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	}
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}
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