conf_test.go

Documentation: net

     1  // Copyright 2015 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // +build darwin dragonfly freebsd linux netbsd openbsd solaris
     6  
     7  package net
     8  
     9  import (
    10  	"os"
    11  	"strings"
    12  	"testing"
    13  )
    14  
    15  type nssHostTest struct {
    16  	host      string
    17  	localhost string
    18  	want      hostLookupOrder
    19  }
    20  
    21  func nssStr(s string) *nssConf { return parseNSSConf(strings.NewReader(s)) }
    22  
    23  // represents a dnsConfig returned by parsing a nonexistent resolv.conf
    24  var defaultResolvConf = &dnsConfig{
    25  	servers:  defaultNS,
    26  	ndots:    1,
    27  	timeout:  5,
    28  	attempts: 2,
    29  	err:      os.ErrNotExist,
    30  }
    31  
    32  func TestConfHostLookupOrder(t *testing.T) {
    33  	tests := []struct {
    34  		name      string
    35  		c         *conf
    36  		resolver  *Resolver
    37  		hostTests []nssHostTest
    38  	}{
    39  		{
    40  			name: "force",
    41  			c: &conf{
    42  				forceCgoLookupHost: true,
    43  				nss:                nssStr("foo: bar"),
    44  				resolv:             defaultResolvConf,
    45  			},
    46  			hostTests: []nssHostTest{
    47  				{"foo.local", "myhostname", hostLookupCgo},
    48  				{"google.com", "myhostname", hostLookupCgo},
    49  			},
    50  		},
    51  		{
    52  			name: "netgo_dns_before_files",
    53  			c: &conf{
    54  				netGo:  true,
    55  				nss:    nssStr("hosts: dns files"),
    56  				resolv: defaultResolvConf,
    57  			},
    58  			hostTests: []nssHostTest{
    59  				{"x.com", "myhostname", hostLookupDNSFiles},
    60  			},
    61  		},
    62  		{
    63  			name: "netgo_fallback_on_cgo",
    64  			c: &conf{
    65  				netGo:  true,
    66  				nss:    nssStr("hosts: dns files something_custom"),
    67  				resolv: defaultResolvConf,
    68  			},
    69  			hostTests: []nssHostTest{
    70  				{"x.com", "myhostname", hostLookupFilesDNS},
    71  			},
    72  		},
    73  		{
    74  			name: "ubuntu_trusty_avahi",
    75  			c: &conf{
    76  				nss:    nssStr("hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4"),
    77  				resolv: defaultResolvConf,
    78  			},
    79  			hostTests: []nssHostTest{
    80  				{"foo.local", "myhostname", hostLookupCgo},
    81  				{"foo.local.", "myhostname", hostLookupCgo},
    82  				{"foo.LOCAL", "myhostname", hostLookupCgo},
    83  				{"foo.LOCAL.", "myhostname", hostLookupCgo},
    84  				{"google.com", "myhostname", hostLookupFilesDNS},
    85  			},
    86  		},
    87  		{
    88  			name: "freebsdlinux_no_resolv_conf",
    89  			c: &conf{
    90  				goos:   "freebsd",
    91  				nss:    nssStr("foo: bar"),
    92  				resolv: defaultResolvConf,
    93  			},
    94  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFilesDNS}},
    95  		},
    96  		// On OpenBSD, no resolv.conf means no DNS.
    97  		{
    98  			name: "openbsd_no_resolv_conf",
    99  			c: &conf{
   100  				goos:   "openbsd",
   101  				resolv: defaultResolvConf,
   102  			},
   103  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFiles}},
   104  		},
   105  		{
   106  			name: "solaris_no_nsswitch",
   107  			c: &conf{
   108  				goos:   "solaris",
   109  				nss:    &nssConf{err: os.ErrNotExist},
   110  				resolv: defaultResolvConf,
   111  			},
   112  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupCgo}},
   113  		},
   114  		{
   115  			name: "openbsd_lookup_bind_file",
   116  			c: &conf{
   117  				goos:   "openbsd",
   118  				resolv: &dnsConfig{lookup: []string{"bind", "file"}},
   119  			},
   120  			hostTests: []nssHostTest{
   121  				{"google.com", "myhostname", hostLookupDNSFiles},
   122  				{"foo.local", "myhostname", hostLookupDNSFiles},
   123  			},
   124  		},
   125  		{
   126  			name: "openbsd_lookup_file_bind",
   127  			c: &conf{
   128  				goos:   "openbsd",
   129  				resolv: &dnsConfig{lookup: []string{"file", "bind"}},
   130  			},
   131  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFilesDNS}},
   132  		},
   133  		{
   134  			name: "openbsd_lookup_bind",
   135  			c: &conf{
   136  				goos:   "openbsd",
   137  				resolv: &dnsConfig{lookup: []string{"bind"}},
   138  			},
   139  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupDNS}},
   140  		},
   141  		{
   142  			name: "openbsd_lookup_file",
   143  			c: &conf{
   144  				goos:   "openbsd",
   145  				resolv: &dnsConfig{lookup: []string{"file"}},
   146  			},
   147  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupFiles}},
   148  		},
   149  		{
   150  			name: "openbsd_lookup_yp",
   151  			c: &conf{
   152  				goos:   "openbsd",
   153  				resolv: &dnsConfig{lookup: []string{"file", "bind", "yp"}},
   154  			},
   155  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupCgo}},
   156  		},
   157  		{
   158  			name: "openbsd_lookup_two",
   159  			c: &conf{
   160  				goos:   "openbsd",
   161  				resolv: &dnsConfig{lookup: []string{"file", "foo"}},
   162  			},
   163  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupCgo}},
   164  		},
   165  		{
   166  			name: "openbsd_lookup_empty",
   167  			c: &conf{
   168  				goos:   "openbsd",
   169  				resolv: &dnsConfig{lookup: nil},
   170  			},
   171  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupDNSFiles}},
   172  		},
   173  		// glibc lacking an nsswitch.conf, per
   174  		// https://www.gnu.org/software/libc/manual/html_node/Notes-on-NSS-Configuration-File.html
   175  		{
   176  			name: "linux_no_nsswitch.conf",
   177  			c: &conf{
   178  				goos:   "linux",
   179  				nss:    &nssConf{err: os.ErrNotExist},
   180  				resolv: defaultResolvConf,
   181  			},
   182  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupDNSFiles}},
   183  		},
   184  		{
   185  			name: "files_mdns_dns",
   186  			c: &conf{
   187  				nss:    nssStr("hosts: files mdns dns"),
   188  				resolv: defaultResolvConf,
   189  			},
   190  			hostTests: []nssHostTest{
   191  				{"x.com", "myhostname", hostLookupFilesDNS},
   192  				{"x.local", "myhostname", hostLookupCgo},
   193  			},
   194  		},
   195  		{
   196  			name: "dns_special_hostnames",
   197  			c: &conf{
   198  				nss:    nssStr("hosts: dns"),
   199  				resolv: defaultResolvConf,
   200  			},
   201  			hostTests: []nssHostTest{
   202  				{"x.com", "myhostname", hostLookupDNS},
   203  				{"x\\.com", "myhostname", hostLookupCgo},     // punt on weird glibc escape
   204  				{"foo.com%en0", "myhostname", hostLookupCgo}, // and IPv6 zones
   205  			},
   206  		},
   207  		{
   208  			name: "mdns_allow",
   209  			c: &conf{
   210  				nss:          nssStr("hosts: files mdns dns"),
   211  				resolv:       defaultResolvConf,
   212  				hasMDNSAllow: true,
   213  			},
   214  			hostTests: []nssHostTest{
   215  				{"x.com", "myhostname", hostLookupCgo},
   216  				{"x.local", "myhostname", hostLookupCgo},
   217  			},
   218  		},
   219  		{
   220  			name: "files_dns",
   221  			c: &conf{
   222  				nss:    nssStr("hosts: files dns"),
   223  				resolv: defaultResolvConf,
   224  			},
   225  			hostTests: []nssHostTest{
   226  				{"x.com", "myhostname", hostLookupFilesDNS},
   227  				{"x", "myhostname", hostLookupFilesDNS},
   228  				{"x.local", "myhostname", hostLookupCgo},
   229  			},
   230  		},
   231  		{
   232  			name: "dns_files",
   233  			c: &conf{
   234  				nss:    nssStr("hosts: dns files"),
   235  				resolv: defaultResolvConf,
   236  			},
   237  			hostTests: []nssHostTest{
   238  				{"x.com", "myhostname", hostLookupDNSFiles},
   239  				{"x", "myhostname", hostLookupDNSFiles},
   240  				{"x.local", "myhostname", hostLookupCgo},
   241  			},
   242  		},
   243  		{
   244  			name: "something_custom",
   245  			c: &conf{
   246  				nss:    nssStr("hosts: dns files something_custom"),
   247  				resolv: defaultResolvConf,
   248  			},
   249  			hostTests: []nssHostTest{
   250  				{"x.com", "myhostname", hostLookupCgo},
   251  			},
   252  		},
   253  		{
   254  			name: "myhostname",
   255  			c: &conf{
   256  				nss:    nssStr("hosts: files dns myhostname"),
   257  				resolv: defaultResolvConf,
   258  			},
   259  			hostTests: []nssHostTest{
   260  				{"x.com", "myhostname", hostLookupFilesDNS},
   261  				{"myhostname", "myhostname", hostLookupCgo},
   262  				{"myHostname", "myhostname", hostLookupCgo},
   263  				{"myhostname.dot", "myhostname.dot", hostLookupCgo},
   264  				{"myHostname.dot", "myhostname.dot", hostLookupCgo},
   265  				{"gateway", "myhostname", hostLookupCgo},
   266  				{"Gateway", "myhostname", hostLookupCgo},
   267  				{"localhost", "myhostname", hostLookupCgo},
   268  				{"Localhost", "myhostname", hostLookupCgo},
   269  				{"anything.localhost", "myhostname", hostLookupCgo},
   270  				{"Anything.localhost", "myhostname", hostLookupCgo},
   271  				{"localhost.localdomain", "myhostname", hostLookupCgo},
   272  				{"Localhost.Localdomain", "myhostname", hostLookupCgo},
   273  				{"anything.localhost.localdomain", "myhostname", hostLookupCgo},
   274  				{"Anything.Localhost.Localdomain", "myhostname", hostLookupCgo},
   275  				{"somehostname", "myhostname", hostLookupFilesDNS},
   276  				{"", "myhostname", hostLookupFilesDNS}, // Issue 13623
   277  			},
   278  		},
   279  		{
   280  			name: "ubuntu14.04.02",
   281  			c: &conf{
   282  				nss:    nssStr("hosts: files myhostname mdns4_minimal [NOTFOUND=return] dns mdns4"),
   283  				resolv: defaultResolvConf,
   284  			},
   285  			hostTests: []nssHostTest{
   286  				{"x.com", "myhostname", hostLookupFilesDNS},
   287  				{"somehostname", "myhostname", hostLookupFilesDNS},
   288  				{"myhostname", "myhostname", hostLookupCgo},
   289  			},
   290  		},
   291  		// Debian Squeeze is just "dns,files", but lists all
   292  		// the default criteria for dns, but then has a
   293  		// non-standard but redundant notfound=return for the
   294  		// files.
   295  		{
   296  			name: "debian_squeeze",
   297  			c: &conf{
   298  				nss:    nssStr("hosts: dns [success=return notfound=continue unavail=continue tryagain=continue] files [notfound=return]"),
   299  				resolv: defaultResolvConf,
   300  			},
   301  			hostTests: []nssHostTest{
   302  				{"x.com", "myhostname", hostLookupDNSFiles},
   303  				{"somehostname", "myhostname", hostLookupDNSFiles},
   304  			},
   305  		},
   306  		{
   307  			name: "resolv.conf-unknown",
   308  			c: &conf{
   309  				nss:    nssStr("foo: bar"),
   310  				resolv: &dnsConfig{servers: defaultNS, ndots: 1, timeout: 5, attempts: 2, unknownOpt: true},
   311  			},
   312  			hostTests: []nssHostTest{{"google.com", "myhostname", hostLookupCgo}},
   313  		},
   314  		// Android should always use cgo.
   315  		{
   316  			name: "android",
   317  			c: &conf{
   318  				goos:   "android",
   319  				nss:    nssStr(""),
   320  				resolv: defaultResolvConf,
   321  			},
   322  			hostTests: []nssHostTest{
   323  				{"x.com", "myhostname", hostLookupCgo},
   324  			},
   325  		},
   326  		// Issue 24393: make sure "Resolver.PreferGo = true" acts like netgo.
   327  		{
   328  			name:     "resolver-prefergo",
   329  			resolver: &Resolver{PreferGo: true},
   330  			c: &conf{
   331  				goos:               "darwin",
   332  				forceCgoLookupHost: true, // always true for darwin
   333  				resolv:             defaultResolvConf,
   334  				nss:                nssStr(""),
   335  				netCgo:             true,
   336  			},
   337  			hostTests: []nssHostTest{
   338  				{"localhost", "myhostname", hostLookupFilesDNS},
   339  			},
   340  		},
   341  	}
   342  
   343  	origGetHostname := getHostname
   344  	defer func() { getHostname = origGetHostname }()
   345  
   346  	for _, tt := range tests {
   347  		for _, ht := range tt.hostTests {
   348  			getHostname = func() (string, error) { return ht.localhost, nil }
   349  
   350  			gotOrder := tt.c.hostLookupOrder(tt.resolver, ht.host)
   351  			if gotOrder != ht.want {
   352  				t.Errorf("%s: hostLookupOrder(%q) = %v; want %v", tt.name, ht.host, gotOrder, ht.want)
   353  			}
   354  		}
   355  	}
   356  
   357  }
   358  
   359  func TestSystemConf(t *testing.T) {
   360  	systemConf()
   361  }
   362
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