RAINS name resolution (#52)

* vendor RAINS deps

* enabled resolving names via RAINS

* temporarily removed vendoring

* updated RAINS bootstrapping

* removed test files

* revised after feedback

* added RAINS deps to vendor.json

* simplified init

* fixed ineffectual assignment

Author: chaehni

bat/bat.go

@@ -74,7 +74,6 @@ var (
 )
 
 func init() {
-
 	flag.BoolVar(&interactive, "in", false, "Lets user choose the path to destination")
 	flag.BoolVar(&ver, "v", false, "Print Version Number")
 	flag.BoolVar(&ver, "version", false, "Print Version Number")

lib/scionutil/hosts.go

@@ -18,23 +18,39 @@ import (
 	"bytes"
 	"fmt"
 	"io/ioutil"
-	"log"
+	"os"
+	"path"
 	"regexp"
 	"strings"
+	"time"
 
+	"github.com/netsec-ethz/rains/pkg/rains"
 	libaddr "github.com/scionproto/scion/go/lib/addr"
+	"github.com/scionproto/scion/go/lib/snet"
 )
 
 type scionAddress struct {
 	ia libaddr.IA
 	l3 libaddr.HostAddr
 }
 
+// hosts file
 var (
 	hostFilePath = "/etc/hosts"
 	addrRegexp   = regexp.MustCompile(`^(?P<ia>\d+-[\d:A-Fa-f]+),\[(?P<host>[^\]]+)\]`)
-	hosts        map[string]scionAddress // hostname -> scionAddress
-	revHosts     map[string][]string     // SCION address w/o port -> hostnames
+	hosts        = make(map[string]scionAddress) // hostname -> scionAddress
+	revHosts     = make(map[string][]string)     // SCION address w/o port -> hostnames
+)
+
+// RAINS
+var (
+	rainsConfigPath = path.Join(os.Getenv("SC"), "gen", "rains.cfg")
+	ctx             = "."                    // use global context
+	qType           = rains.OTScionAddr4     // request SCION IPv4 addresses
+	qOpts           = []rains.Option{}       // no options
+	expire          = 5 * time.Minute        // sensible expiry date?
+	timeout         = 500 * time.Millisecond // timeout for query
+	rainsServer     *snet.Addr               // resolver address
 )
 
 const (
@@ -43,19 +59,20 @@ const (
 )
 
 func init() {
+	// parse hosts file
 	hostsFile, err := readHostsFile()
-	if err != nil {
-		hostsFile = []byte{}
-	}
-	parseHostsFile(hostsFile)
-	if err != nil {
-		log.Fatal(err)
+	if err == nil {
+		parseHostsFile(hostsFile)
 	}
+
+	// read RAINS server address
+	rainsServer = readRainsConfig()
 }
 
 // AddHost adds a host to the map of known hosts
 // An error is returned if the address has a wrong format or
 // the hostname already exists
+// The added host will not persist between program executions
 func AddHost(hostname, address string) error {
 	if addrs, ok := hosts[hostname]; ok {
 		return fmt.Errorf("Host %q already exists, address(es): %v", hostname, addrs)
@@ -72,14 +89,35 @@ func AddHost(hostname, address string) error {
 
 // GetHostByName returns the IA and HostAddr corresponding to hostname
 func GetHostByName(hostname string) (libaddr.IA, libaddr.HostAddr, error) {
+	// try to resolve hostname locally
 	addr, ok := hosts[hostname]
-	if !ok {
-		return libaddr.IA{}, nil, fmt.Errorf("Address for host %q not found", hostname)
+	if ok {
+		return addr.ia, addr.l3, nil
+	}
+
+	if rainsServer == nil {
+		return libaddr.IA{}, nil, fmt.Errorf("Could not resolve %q, no RAINS server configured", hostname)
 	}
-	return addr.ia, addr.l3, nil
+
+	// fall back to RAINS
+
+	// TODO(chaehni): This call can sometimes cause a timeout even though the server is reachable (see issue #221)
+	// The timeout value has been decreased to counter this behavior until the problem is resolved.
+	reply, err := rains.Query(hostname, ctx, []rains.Type{qType}, qOpts, expire, timeout, rainsServer)
+	if err != nil {
+		return libaddr.IA{}, nil, fmt.Errorf("Address for host %q not found: %v", hostname, err)
+	}
+	scionAddr, err := addrFromString(reply[qType])
+	if err != nil {
+		return libaddr.IA{}, nil, fmt.Errorf("Address for host %q invalid: %v", hostname, err)
+	}
+
+	return scionAddr.ia, scionAddr.l3, nil
+
 }
 
 // GetHostnamesByAddress returns the hostnames corresponding to address
+// TODO: (chaehni) RAINS address query to resolve address to name
 func GetHostnamesByAddress(address string) ([]string, error) {
 	match := addrRegexp.FindString(address)
 	host, ok := revHosts[match]
@@ -98,8 +136,6 @@ func readHostsFile() ([]byte, error) {
 }
 
 func parseHostsFile(hostsFile []byte) {
-	hosts = make(map[string]scionAddress)
-	revHosts = make(map[string][]string)
 	lines := bytes.Split(hostsFile, []byte("\n"))
 	for _, line := range lines {
 		fields := strings.Fields(string(line))
@@ -124,8 +160,23 @@ func parseHostsFile(hostsFile []byte) {
 	}
 }
 
+func readRainsConfig() *snet.Addr {
+	bs, err := ioutil.ReadFile(rainsConfigPath)
+	if err != nil {
+		return nil
+	}
+	addr, err := snet.AddrFromString(strings.TrimSpace(string(bs)))
+	if err != nil {
+		return nil
+	}
+	return addr
+}
+
 func addrFromString(addr string) (scionAddress, error) {
 	parts := addrRegexp.FindStringSubmatch(addr)
+	if parts == nil {
+		return scionAddress{}, fmt.Errorf("No valid SCION address: %q", addr)
+	}
 	ia, err := libaddr.IAFromString(parts[iaIndex])
 	if err != nil {
 		return scionAddress{}, fmt.Errorf("Invalid IA string: %v", parts[iaIndex])

lib/scionutil/initialization.go

@@ -67,6 +67,9 @@ func GetDefaultDispatcher() string {
 // GetLocalhost returns a local SCION address an application can bind to
 func GetLocalhost() (*snet.Addr, error) {
 	str, err := GetLocalhostString()
+	if err != nil {
+		return nil, err
+	}
 	addr, err := snet.AddrFromString(str)
 	if err != nil {
 		return nil, err

vendor/vendor.json

@@ -90,6 +90,12 @@
 			"revision": "198357931e6129b810c9c77c12e0dd754846170c",
 			"revisionTime": "2018-03-06T13:52:33Z"
 		},
+		{
+			"checksumSHA1": "I9USlnFClp2E/Ap9vfano+H7/bk=",
+			"path": "github.com/britram/borat",
+			"revision": "f891bcfcfb9b69c58b8348ec13eadad5bf2a5a2d",
+			"revisionTime": "2018-10-11T13:03:14Z"
+		},
 		{
 			"checksumSHA1": "PYXuf7wvcj492uWhjvmXlyyQUYc=",
 			"path": "github.com/cheekybits/genny/generic",
@@ -316,6 +322,90 @@
 			"revision": "b3511bfdd742af558b54eb6160aca9446d762a19",
 			"revisionTime": "2018-07-18T00:29:43Z"
 		},
+		{
+			"checksumSHA1": "oAzVVzZ8G62Tc8Z6QKKuFmI79bk=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/algorithmTypes",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "74bjp4b7F8YZIKKsMTfTF1cPafU=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/cbor",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "JF0HSoKCifEckCKfi9eX54lxUb0=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/connection",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "1WY5z5R39nDBaunrcEnUs1l0itI=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/datastructures/bitarray",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "vq0RzZ/9ctflFEOJ4nn/arquwwA=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/keys",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "7n3dj+WS6lVlWGXNLfVYzPOT8tU=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/message",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "gR86BQoomx0zX22xefse2trtHJw=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/object",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "aaQD2Wm6Q9yETQaqk0bByLgYyNE=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/query",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "I3t/4fX/VIEUBhaEZlja2G0EcBE=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/section",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "lCbtqf/yBKG45tYEZs9SvjODing=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/signature",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "0mE6gU++UPNzNQmeRkQmTah/C/U=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/token",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "DqmAjSj4jCz7MIk72DFhu8WxzWw=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/util",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "chhRV8twUksUbKcKaRMmXhWKRlQ=",
+			"path": "github.com/netsec-ethz/rains/internal/pkg/zonefile",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
+		{
+			"checksumSHA1": "jup0QWu5f6W4YKZkZ1YZnWlfKJ4=",
+			"path": "github.com/netsec-ethz/rains/pkg/rains",
+			"revision": "ea31b8af8390375bf72b810804de21f17036a5d0",
+			"revisionTime": "2019-03-25T15:14:30Z"
+		},
 		{
 			"checksumSHA1": "SQi5yeNb9HnAMRpEhQgcv9x9yKc=",
 			"path": "github.com/patrickmn/go-cache",
@@ -669,6 +759,12 @@
 			"revision": "8ac0e0d97ce45cd83d1d7243c060cb8461dda5e9",
 			"revisionTime": "2018-06-07T13:59:11Z"
 		},
+		{
+			"checksumSHA1": "asZBHvcTKF5gVlI7AYnMlLXRYys=",
+			"path": "golang.org/x/crypto/sha3",
+			"revision": "b7391e95e576cacdcdd422573063bc057239113d",
+			"revisionTime": "2019-03-19T22:29:04Z"
+		},
 		{
 			"checksumSHA1": "GtamqiJoL7PGHsN454AoffBFMa8=",
 			"path": "golang.org/x/net/context",
@@ -699,6 +795,12 @@
 			"revision": "65e2d4e15006aab9813ff8769e768bbf4bb667a0",
 			"revisionTime": "2019-02-01T23:59:58Z"
 		},
+		{
+			"checksumSHA1": "c2uqM0KcVJ2SFu/9Nt4w63GZ9xo=",
+			"path": "golang.org/x/sys/cpu",
+			"revision": "f49334f85ddcf0f08d7fb6dd7363e9e6d6b777eb",
+			"revisionTime": "2019-03-21T05:14:46Z"
+		},
 		{
 			"checksumSHA1": "tY+5thYxjKDUQyQXYcBqogmMS5U=",
 			"license": "3-BSD",