[tor-commits] [goptlib/master] Make resolveAddr more strict.

[dcf at torproject.org]

commit 43b5924d68041cf73f473b56c275e5983ee40014
Author: David Fifield <david at bamsoftware.com>
Date:   Sat Nov 9 18:34:05 2013 -0800

    Make resolveAddr more strict.
    
    Go's net.ResolveTCPAddr allows an empty host or port part, returning for
    them nil and 0 respectively. It will also resolve names, which I don't
    think we need so we should avoid it for now.
    
    These are the test failures that this change fixes:
    --- FAIL: TestResolveAddr (0.00 seconds)
            pt_test.go:201: "" unexpectedly succeeded: "<nil>:0"
            pt_test.go:201: "1.2.3.4:" unexpectedly succeeded: "1.2.3.4:0"
            pt_test.go:201: ":9999" unexpectedly succeeded: "<nil>:9999"
            pt_test.go:201: "[1:2::3:4]:" unexpectedly succeeded: "[1:2::3:4]:0"
            pt_test.go:201: "localhost:9999" unexpectedly succeeded: "127.0.0.1:9999"
            pt_test.go:201: "[localhost]:9999" unexpectedly succeeded: "127.0.0.1:9999"
---
 pt.go |   43 +++++++++++++++++++++++++++++++------------
 1 file changed, 31 insertions(+), 12 deletions(-)

diff --git a/pt.go b/pt.go
index 45efc04..308238c 100644
--- a/pt.go
+++ b/pt.go
@@ -245,21 +245,40 @@ type BindAddr struct {
 	Addr       *net.TCPAddr
 }
 
-// Resolve an address string into a net.TCPAddr.
+// Resolve an address string into a net.TCPAddr. We are a bit more strict than
+// net.ResolveTCPAddr; we don't allow an empty host or port, and the host part
+// must be a literal IP address.
 func resolveAddr(addrStr string) (*net.TCPAddr, error) {
-	addr, err := net.ResolveTCPAddr("tcp", addrStr)
-	if err == nil {
-		return addr, nil
-	}
-	// Before the fixing of bug #7011, tor doesn't put brackets around IPv6
-	// addresses. Split after the last colon, assuming it is a port
-	// separator, and try adding the brackets.
-	parts := strings.Split(addrStr, ":")
-	if len(parts) <= 2 {
+	ipStr, portStr, err := net.SplitHostPort(addrStr)
+	if err != nil {
+		// Before the fixing of bug #7011, tor doesn't put brackets around IPv6
+		// addresses. Split after the last colon, assuming it is a port
+		// separator, and try adding the brackets.
+		parts := strings.Split(addrStr, ":")
+		if len(parts) <= 2 {
+			return nil, err
+		}
+		addrStr := "[" + strings.Join(parts[:len(parts)-1], ":") + "]:" + parts[len(parts)-1]
+		ipStr, portStr, err = net.SplitHostPort(addrStr)
+	}
+	if err != nil {
+		return nil, err
+	}
+	if ipStr == "" {
+		return nil, net.InvalidAddrError(fmt.Sprintf("address string %q lacks a host part", addrStr))
+	}
+	if portStr == "" {
+		return nil, net.InvalidAddrError(fmt.Sprintf("address string %q lacks a port part", addrStr))
+	}
+	ip, err := net.ResolveIPAddr("ip", ipStr)
+	if err != nil {
+		return nil, err
+	}
+	port, err := net.LookupPort("tcp", portStr)
+	if err != nil {
 		return nil, err
 	}
-	addrStr = "[" + strings.Join(parts[:len(parts)-1], ":") + "]:" + parts[len(parts)-1]
-	return net.ResolveTCPAddr("tcp", addrStr)
+	return &net.TCPAddr{IP: ip.IP, Port: port, Zone: ip.Zone}, nil
 }
 
 // Return a new slice, the members of which are those members of addrs having a