Merge pull request #145 from angelabriel/master

Read 1024 Byte from /proc/sys files instead of 512

sap/note/ini.go

@@ -304,7 +304,7 @@ func (vend INISettings) Apply() error {
 			continue
 		}
 
-		if revertValues && vend.SysctlParams[param.Key] != "" {
+		if revertValues && vend.SysctlParams[param.Key] != "PNA" {
 			// revert parameter value
 			pvendID, flstates = vend.setRevertParamValues(param.Key)
 		}
@@ -416,7 +416,7 @@ func (vend INISettings) setRevertParamValues(key string) (string, string) {
 func (vend INISettings) createParamSavedStates(key, flstates string) {
 	// do not write parameter values to the saved state file during
 	// a pure 'verify' action
-	if _, ok := vend.ValuesToApply["verify"]; !ok && vend.SysctlParams[key] != "" {
+	if _, ok := vend.ValuesToApply["verify"]; !ok && vend.SysctlParams[key] != "PNA" {
 		start := vend.SysctlParams[key]
 		if key == "UserTasksMax" {
 			if system.SystemctlIsStarting() {
@@ -437,7 +437,7 @@ func (vend INISettings) createParamSavedStates(key, flstates string) {
 func (vend INISettings) addParamSavedStates(key string) {
 	// do not write parameter values to the saved state file during
 	// a pure 'verify' action
-	if _, ok := vend.ValuesToApply["verify"]; !ok && vend.SysctlParams[key] != "" {
+	if _, ok := vend.ValuesToApply["verify"]; !ok && vend.SysctlParams[key] != "PNA" {
 		AddParameterNoteValues(key, vend.SysctlParams[key], vend.ID)
 	}
 }

system/sys.go

@@ -3,6 +3,7 @@ package system
 // Manipulate /sys/ switches.
 
 import (
+	"bytes"
 	"os"
 	"path"
 	"regexp"
@@ -17,11 +18,26 @@ func GetSysString(parameter string) (string, error) {
 
 // getKeyStringFromPath generalizes the extraction of a string from path
 func getKeyStringFromPath(basePath string, parameter string, logFrom string) (string, error) {
-	val, err := os.ReadFile(path.Join(basePath, strings.Replace(parameter, ".", "/", -1)))
+	// Seams that os.ReadFile reads only 512 Bytes, if it can not detect the
+	// filesize (which is the case for /proc/sys files, returns always 0)
+	// This might not enough for sysctl parameter like
+	// 'net.ipv4.ip_local_reserved_ports'
+	srcFile := path.Join(basePath, strings.Replace(parameter, ".", "/", -1))
+	file, err := os.Open(srcFile)
+	if err != nil {
+		WarningLog("failed to open %s : %v", srcFile, err)
+		return "PNA", err
+	}
+	defer file.Close()
+	val := make([]byte, 1024)
+	bytesread, err := file.Read(val)
+	DebugLog("getKeyStringFromPath - bytes read from '%s': '%+v'\n", srcFile, bytesread)
 	if err != nil {
 		WarningLog("failed to read %v string key '%s': %v", logFrom, parameter, err)
 		return "PNA", err
 	}
+	// remove NULL
+	val = bytes.Trim(val, "\x00")
 	return strings.TrimSpace(string(val)), nil
 }
 

system/sysctl.go

@@ -224,6 +224,9 @@ func SetSysctlString(parameter, value string) error {
 		WarningLog("value is '%s', so sysctl key '%s' is/was not supported by os, skipping.", value, parameter)
 		return nil
 	}
+	if value == "" {
+		value = "\n"
+	}
 	err := os.WriteFile(path.Join("/proc/sys", strings.Replace(parameter, ".", "/", -1)), []byte(value), 0644)
 	if os.IsNotExist(err) {
 		WarningLog("sysctl key '%s' is not supported by os, skipping.", parameter)