113 lines
2.8 KiB
Go
113 lines
2.8 KiB
Go
// Copyright (c) HashiCorp, Inc.
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// SPDX-License-Identifier: MPL-2.0
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//go:build linux
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package fingerprint
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import (
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"bufio"
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"fmt"
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"os"
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"regexp"
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"strconv"
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"github.com/hashicorp/go-multierror"
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"github.com/hashicorp/nomad/nomad/structs"
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"github.com/shirou/gopsutil/v3/host"
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)
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const bridgeKernelModuleName = "bridge"
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const (
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dynamicModuleRe = `%s\s+.*$`
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builtinModuleRe = `.+/%s.ko$`
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dependsModuleRe = `.+/%s.ko(\.xz)?:.*$`
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)
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func (f *BridgeFingerprint) Fingerprint(req *FingerprintRequest, resp *FingerprintResponse) error {
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if err := f.detect(bridgeKernelModuleName); err != nil {
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f.logger.Warn("failed to detect bridge kernel module, bridge network mode disabled", "error", err)
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return nil
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}
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resp.NodeResources = &structs.NodeResources{
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Networks: []*structs.NetworkResource{{
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Mode: "bridge",
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}},
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NodeNetworks: []*structs.NodeNetworkResource{{
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Mode: "bridge",
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Device: req.Config.BridgeNetworkName,
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}},
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}
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resp.AddAttribute("nomad.bridge.hairpin_mode",
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strconv.FormatBool(req.Config.BridgeNetworkHairpinMode))
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resp.Detected = true
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return nil
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}
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func (f *BridgeFingerprint) regexp(pattern, module string) *regexp.Regexp {
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return regexp.MustCompile(fmt.Sprintf(pattern, module))
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}
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func (f *BridgeFingerprint) detect(module string) error {
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// accumulate errors from every place we might find the module
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var errs error
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// check if the module has been dynamically loaded
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dynamicPath := "/proc/modules"
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if err := f.searchFile(module, dynamicPath, f.regexp(dynamicModuleRe, module)); err != nil {
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errs = multierror.Append(errs, err)
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} else {
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return nil
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}
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// will need kernel info to look for builtin and unloaded modules
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hostInfo, err := host.Info()
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if err != nil {
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return err
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}
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// check if the module is builtin to the kernel
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builtinPath := fmt.Sprintf("/lib/modules/%s/modules.builtin", hostInfo.KernelVersion)
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if err := f.searchFile(module, builtinPath, f.regexp(builtinModuleRe, module)); err != nil {
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errs = multierror.Append(errs, err)
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} else {
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return nil
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}
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// check if the module is dynamic but unloaded (will have a dep entry)
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dependsPath := fmt.Sprintf("/lib/modules/%s/modules.dep", hostInfo.KernelVersion)
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if err := f.searchFile(module, dependsPath, f.regexp(dependsModuleRe, module)); err != nil {
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errs = multierror.Append(errs, err)
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} else {
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return nil
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}
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return errs
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}
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func (f *BridgeFingerprint) searchFile(module, filename string, re *regexp.Regexp) error {
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file, err := os.Open(filename)
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if err != nil {
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return fmt.Errorf("failed to open %s: %v", filename, err)
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}
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defer func() {
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_ = file.Close()
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}()
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scanner := bufio.NewScanner(file)
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for scanner.Scan() {
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if re.MatchString(scanner.Text()) {
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return nil // found the module!
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}
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}
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if err := scanner.Err(); err != nil {
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return fmt.Errorf("failed to scan %s: %v", filename, err)
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}
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return fmt.Errorf("module %s not in %s", module, filename)
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}
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