Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

internal/snmp/mib_loader.go

@@ -0,0 +1,140 @@
+package snmp
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"sync"
+
+	"github.com/sleepinggenius2/gosmi"
+
+	"github.com/influxdata/telegraf"
+)
+
+// must init, append path for each directory, load module for every file
+// or gosmi will fail without saying why
+var m sync.Mutex
+var once sync.Once
+var cache = make(map[string]bool)
+
+type MibLoader interface {
+	// appendPath takes the path of a directory
+	appendPath(path string)
+
+	// loadModule takes the name of a file in one of the
+	// directories. Basename only, no relative or absolute path
+	loadModule(path string) error
+}
+
+type GosmiMibLoader struct{}
+
+func (*GosmiMibLoader) appendPath(path string) {
+	m.Lock()
+	defer m.Unlock()
+
+	gosmi.AppendPath(path)
+}
+
+func (*GosmiMibLoader) loadModule(path string) error {
+	m.Lock()
+	defer m.Unlock()
+
+	_, err := gosmi.LoadModule(path)
+	return err
+}
+
+// will give all found folders to gosmi and load in all modules found in the folders
+func LoadMibsFromPath(paths []string, log telegraf.Logger, loader MibLoader) error {
+	folders, err := walkPaths(paths, log)
+	if err != nil {
+		return err
+	}
+	for _, path := range folders {
+		loader.appendPath(path)
+		modules, err := os.ReadDir(path)
+		if err != nil {
+			log.Warnf("Can't read directory %v", modules)
+			continue
+		}
+
+		for _, entry := range modules {
+			info, err := entry.Info()
+			if err != nil {
+				log.Warnf("Couldn't get info for %v: %v", entry.Name(), err)
+				continue
+			}
+			if info.Mode()&os.ModeSymlink != 0 {
+				symlink := filepath.Join(path, info.Name())
+				target, err := filepath.EvalSymlinks(symlink)
+				if err != nil {
+					log.Warnf("Couldn't evaluate symbolic links for %v: %v", symlink, err)
+					continue
+				}
+				// replace symlink's info with the target's info
+				info, err = os.Lstat(target)
+				if err != nil {
+					log.Warnf("Couldn't stat target %v: %v", target, err)
+					continue
+				}
+			}
+			if info.Mode().IsRegular() {
+				err := loader.loadModule(info.Name())
+				if err != nil {
+					log.Warnf("Couldn't load module %v: %v", info.Name(), err)
+					continue
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// should walk the paths given and find all folders
+func walkPaths(paths []string, log telegraf.Logger) ([]string, error) {
+	once.Do(gosmi.Init)
+
+	folders := make([]string, 0)
+	for _, mibPath := range paths {
+		// Check if we loaded that path already and skip it if so
+		m.Lock()
+		cached := cache[mibPath]
+		cache[mibPath] = true
+		m.Unlock()
+		if cached {
+			continue
+		}
+
+		err := filepath.Walk(mibPath, func(path string, info os.FileInfo, err error) error {
+			if info == nil {
+				log.Warnf("No mibs found")
+				if os.IsNotExist(err) {
+					log.Warnf("MIB path doesn't exist: %q", mibPath)
+				} else if err != nil {
+					return err
+				}
+				return nil
+			}
+
+			if info.Mode()&os.ModeSymlink != 0 {
+				target, err := filepath.EvalSymlinks(path)
+				if err != nil {
+					log.Warnf("Couldn't evaluate symbolic links for %v: %v", path, err)
+				}
+				info, err = os.Lstat(target)
+				if err != nil {
+					log.Warnf("Couldn't stat target %v: %v", target, err)
+				}
+				path = target
+			}
+			if info.IsDir() {
+				folders = append(folders, path)
+			}
+
+			return nil
+		})
+		if err != nil {
+			return folders, fmt.Errorf("couldn't walk path %q: %w", mibPath, err)
+		}
+	}
+	return folders, nil
+}