doggo/cmd/parse.go

75 lines
2.1 KiB
Go

package main
import (
"strings"
"github.com/miekg/dns"
)
func (hub *Hub) loadQueryArgs() error {
err := hub.loadNamedArgs()
err = hub.loadFreeArgs()
if err != nil {
hub.Logger.WithError(err).Error("Error parsing arguments")
hub.Logger.Exit(2)
}
err = hub.initResolver()
if err != nil {
hub.Logger.WithError(err).Error("Error parsing nameservers")
hub.Logger.Exit(2)
}
hub.loadFallbacks()
return err
}
// loadFreeArgs tries to parse all the arguments
// given to the CLI. These arguments don't have any specific
// order so we have to deduce based on the pattern of argument.
// For eg, a nameserver must always begin with `@`. In this
// pattern we deduce the arguments and map it to internal query
// options. In case an argument isn't able to fit in any of the existing
// pattern it is considered to be a "query name".
func (hub *Hub) loadFreeArgs() error {
for _, arg := range hub.FreeArgs {
if strings.HasPrefix(arg, "--") || strings.HasPrefix(arg, "-") {
continue
}
if strings.HasPrefix(arg, "@") {
hub.QueryFlags.Nameservers = append(hub.QueryFlags.Nameservers, strings.Trim(arg, "@"))
} else if _, ok := dns.StringToType[strings.ToUpper(arg)]; ok {
hub.QueryFlags.QTypes = append(hub.QueryFlags.QTypes, arg)
} else if _, ok := dns.StringToClass[strings.ToUpper(arg)]; ok {
hub.QueryFlags.QClasses = append(hub.QueryFlags.QClasses, arg)
} else {
// if nothing matches, consider it's a query name.
hub.QueryFlags.QNames = append(hub.QueryFlags.QNames, arg)
}
}
return nil
}
// loadNamedArgs checks for all flags and loads their
// values inside the Hub.
func (hub *Hub) loadNamedArgs() error {
// Unmarshall flags to the struct.
err := k.Unmarshal("", &hub.QueryFlags)
if err != nil {
return err
}
return nil
}
// loadFallbacks sets fallbacks for options
// that are not specified by the user.
func (hub *Hub) loadFallbacks() {
if len(hub.QueryFlags.QTypes) == 0 {
hub.QueryFlags.QTypes = append(hub.QueryFlags.QTypes, "A")
}
if len(hub.QueryFlags.QClasses) == 0 {
hub.QueryFlags.QClasses = append(hub.QueryFlags.QClasses, "IN")
}
}