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	Create plugin/pkg/transport that holds the transport related functions. This needed to be a new pkg to prevent cyclic import errors. This cleans up a bunch of duplicated code in core/dnsserver that also tried to parse a transport (now all done in transport.Parse). Signed-off-by: Miek Gieben <miek@miek.nl>
		
			
				
	
	
		
			99 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			99 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
| package dnsutil
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| 
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| import (
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| 	"fmt"
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| 	"net"
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| 	"os"
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| 
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| 	"github.com/coredns/coredns/plugin/pkg/transport"
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| 
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| 	"github.com/miekg/dns"
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| )
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| 
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| // ParseHostPortOrFile parses the strings in s, each string can either be a
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| // address, [scheme://]address:port or a filename. The address part is checked
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| // and in case of filename a resolv.conf like file is (assumed) and parsed and
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| // the nameservers found are returned.
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| func ParseHostPortOrFile(s ...string) ([]string, error) {
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| 	var servers []string
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| 	for _, h := range s {
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| 
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| 		trans, host := transport.Parse(h)
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| 
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| 		addr, _, err := net.SplitHostPort(host)
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| 		if err != nil {
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| 			// Parse didn't work, it is not a addr:port combo
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| 			if net.ParseIP(host) == nil {
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| 				// Not an IP address.
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| 				ss, err := tryFile(host)
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| 				if err == nil {
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| 					servers = append(servers, ss...)
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| 					continue
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| 				}
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| 				return servers, fmt.Errorf("not an IP address or file: %q", host)
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| 			}
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| 			var ss string
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| 			switch trans {
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| 			case transport.DNS:
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| 				ss = net.JoinHostPort(host, "53")
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| 			case transport.TLS:
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| 				ss = transport.TLS + "://" + net.JoinHostPort(host, transport.TLSPort)
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| 			case transport.GRPC:
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| 				ss = transport.GRPC + "://" + net.JoinHostPort(host, transport.GRPCPort)
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| 			case transport.HTTPS:
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| 				ss = transport.HTTPS + "://" + net.JoinHostPort(host, transport.HTTPSPort)
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| 			}
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| 			servers = append(servers, ss)
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| 			continue
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| 		}
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| 
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| 		if net.ParseIP(addr) == nil {
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| 			// Not an IP address.
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| 			ss, err := tryFile(host)
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| 			if err == nil {
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| 				servers = append(servers, ss...)
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| 				continue
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| 			}
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| 			return servers, fmt.Errorf("not an IP address or file: %q", host)
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| 		}
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| 		servers = append(servers, h)
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| 	}
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| 	return servers, nil
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| }
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| 
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| // Try to open this is a file first.
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| func tryFile(s string) ([]string, error) {
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| 	c, err := dns.ClientConfigFromFile(s)
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| 	if err == os.ErrNotExist {
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| 		return nil, fmt.Errorf("failed to open file %q: %q", s, err)
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| 	} else if err != nil {
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| 		return nil, err
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| 	}
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| 
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| 	servers := []string{}
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| 	for _, s := range c.Servers {
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| 		servers = append(servers, net.JoinHostPort(s, c.Port))
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| 	}
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| 	return servers, nil
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| }
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| 
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| // ParseHostPort will check if the host part is a valid IP address, if the
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| // IP address is valid, but no port is found, defaultPort is added.
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| func ParseHostPort(s, defaultPort string) (string, error) {
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| 	addr, port, err := net.SplitHostPort(s)
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| 	if port == "" {
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| 		port = defaultPort
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| 	}
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| 	if err != nil {
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| 		if net.ParseIP(s) == nil {
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| 			return "", fmt.Errorf("must specify an IP address: `%s'", s)
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| 		}
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| 		return net.JoinHostPort(s, port), nil
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| 	}
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| 
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| 	if net.ParseIP(addr) == nil {
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| 		return "", fmt.Errorf("must specify an IP address: `%s'", addr)
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| 	}
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| 	return net.JoinHostPort(addr, port), nil
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| }
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