Updated for go 1.16 modules

pkg/state/header.go

@@ -0,0 +1,57 @@
+package state
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"io"
+
+	"git.adyxax.org/adyxax/bareos-zabbix-check/pkg/utils"
+	"github.com/pkg/errors"
+)
+
+// c.StateFile()HeaderLength : the length of the state file header struct
+const headerLength = 14 + 2 + 4 + 4 + 8 + 8 // + 19*8
+
+// Header is a structure to hold the header of the state file. It is statically aligned for amd64 architecture
+// This comes from bareos repository file core/src/lib/bsys.cc:525 and core/src/lib/bsys.cc:652
+type Header struct {
+	ID                        [14]byte
+	_                         int16
+	Version                   int32
+	_                         int32
+	LastJobsAddr              uint64
+	EndOfRecentJobResultsList uint64
+	//Reserved                  [19]uint64
+}
+
+func (sfh *Header) String() string {
+	return fmt.Sprintf("ID: \"%s\", Version: %d, LastJobsAddr: %d, EndOfRecentJobResultsList: %d",
+		string(sfh.ID[:utils.Clen(sfh.ID[:])]), sfh.Version, sfh.LastJobsAddr, sfh.EndOfRecentJobResultsList)
+}
+
+// ParseHeader parses a Header struct
+func ParseHeader(handle io.Reader) (h *Header, err error) {
+	// Parsing the state file header
+	data := make([]byte, headerLength)
+	n, err := handle.Read(data)
+	if err != nil {
+		return nil, errors.Wrap(err, "Corrupted state file")
+	}
+	if n != headerLength {
+		return nil, fmt.Errorf("Corrupted state file : invalid header length")
+	}
+	buffer := bytes.NewBuffer(data)
+	h = &Header{}
+	_ = binary.Read(buffer, binary.LittleEndian, h) // this call cannot fail since we checked the header length
+	if id := string(h.ID[:utils.Clen(h.ID[:])]); id != "Bareos State\n" && id != "Bacula State\n" {
+		return nil, fmt.Errorf("Corrupted state file : Not a bareos or bacula state file : %s", id)
+	}
+	if h.Version != 4 {
+		return nil, fmt.Errorf("Invalid state file : This script only supports bareos state file version 4, got %d", h.Version)
+	}
+	if h.LastJobsAddr == 0 {
+		return nil, fmt.Errorf("No jobs exist in the state file")
+	}
+	return
+}