SUSE/saptune

package note

import (
    "fmt"
    "github.com/SUSE/saptune/system"
    "os"
    "strconv"
    "strings"
)

// section [limits]

// GetLimitsVal initialise the security limit structure with the current
// system settings
func GetLimitsVal(value string) (string, string, error) {
    info := ""
    // Find out current limits
    limit := value
    if limit != "" && limit != "NA" {
        lim := strings.Fields(limit)
        // dom=[0], type=[1], item=[2], value=[3]
        // no check, that the syntax/order of the entry in the config file is
        // a valid limits entry

        // /etc/security/limits.d/saptune-<domain>-<item>-<type>.conf
        if len(lim) < 3 {
            return "", info, fmt.Errorf("Wrong format of limit entry in Note definition file. Please check")
        } else if len(lim) == 3 {
            lim = append(lim, "")
        } else if len(lim) > 3 {
            info = getLimitInfo(lim[3])
        }
        dropInFile := fmt.Sprintf("/etc/security/limits.d/saptune-%s-%s-%s.conf", lim[0], lim[2], lim[1])
        secLimits, err := system.ParseSecLimitsFile(dropInFile)
        if err != nil {
            //ANGI TODO - check, if other files in /etc/security/limits.d contain a value for the touple "<domain>-<item>-<type>"
            return "", info, err
        }
        lim[3], _ = secLimits.Get(lim[0], lim[1], lim[2])
        if lim[3] == "" {
            lim[3] = "NA"
        }
        // current limit found
        limit = strings.Join(lim, " ")
    }
    return limit, info, nil
}

// OptLimitsVal optimises the security limit structure with the settings
// from the configuration file or with a calculation
func OptLimitsVal(actval, cfgval string) string {
    cfgval = strings.Join(strings.Fields(strings.TrimSpace(cfgval)), " ")
    return cfgval
}

// SetLimitsVal applies the settings to the system
func SetLimitsVal(key, noteID, value string, revert bool) error {
    var err error
    var secLimits *system.SecLimits
    limit := value
    if limit != "" && limit != "NA" {
        lim := strings.Fields(limit)
        // dom=[0], type=[1], item=[2], value=[3]

        // /etc/security/limits.d/saptune-<domain>-<item>-<type>.conf
        dropInFile := fmt.Sprintf("/etc/security/limits.d/saptune-%s-%s-%s.conf", lim[0], lim[2], lim[1])

        if revert && IsLastNoteOfParameter(key) {
            // revert - remove limits drop-in file
            os.Remove(dropInFile)
            return nil
        }

        secLimits, err = system.ParseSecLimitsFile(dropInFile)
        if err != nil {
            return err
        }

        if lim[3] != "" && lim[3] != "NA" {
            // revert with value from another former applied note
            // or
            // apply - Prepare limits drop-in file
            secLimits.Set(lim[0], lim[1], lim[2], lim[3])

            //err = secLimits.Apply()
            err = secLimits.ApplyDropIn(lim, noteID)
        }
    }
    return err
}

// getLimitInfo returns info, if config value exceeds system limit for nofile
func getLimitInfo(val string) string {
    info := ""
    if val != "" && val != "NA" && val != "infinity" && val != "unlimited" && val != "-1" {
        nrOpen, _ := system.GetSysctlInt("fs.nr_open")
        ilim, _ := strconv.Atoi(val)
        if ilim > nrOpen {
            info = "limit_exceeded"
        }
    }
    return info
}