WIP: checks before starting jail

cmd/start.go

@@ -277,6 +277,43 @@ func StartJail(args []string) {
 			continue
 		}
 		
+		if len(cj.hostid) > 0 && cj.Hostid_strict_check == true {
+			hostid, err := ioutil.ReadFile("/etc/hostid")
+			if err != nil {
+				return err
+			}
+			hostid = []byte(strings.Replace(string(hostid), "\n", "", -1))
+			if strings.EqualFold(hostid, cj.hostid) == false {
+				fmt.Printf("hostid is not matching and hostid_strict_check is on. Not starting jail.\n")
+				return
+			}
+		}
+		
+		var props_missing []string
+		// DHCP can also be set with "DHCP" value in ip4_addr
+		if cj.Dhcp == true || strings.EqualFold(cj.Ip4_addr, "DHCP") == true {
+			if cj.Bpf == 0 {
+				props_missing = append(props_missing, fmt.Sprintf("%s: dhcp requires bpf", cj.Name))
+			}
+			if cj.Vnet == 0 {
+				props_missing = append(props_missing, fmt.Sprintf("%s: dhcp requires vnet", cj.Name))
+			}
+		}
+		// TODO : Check that this nat_forwards exemple is OK : 
+		// tcp(80:8080),tcp(3300-3310:33060-33070)
+		// If OK, it should map jail port 80 to 8080 on the host
+		//   and range 3300-3310 on jail to 33060-33070 on the host
+		if cj.Nat > 0 && strings.EqualFold(cj.Nat_forwards, "none") == false {
+			// If NAT && port forwarding is enabled, check that port does not conflict 
+			//   with another running jail
+			for _, j := range gJails {
+				if j.Running == false {
+					continue
+				}
+				// TODO : check!
+			}
+		}
+		
 		fmt.Printf("  > Mount special filesystems:\n")
 		err := mountAllJailFsFromHost(cj)
 		if err != nil {