feat: ndots and search list support

pull/2/head
Karan Sharma 2020-12-13 12:45:45 +05:30
parent 7df12b2229
commit d9715b1932
10 changed files with 199 additions and 82 deletions

18
TODO.md
View File

@ -5,26 +5,26 @@
- [x]] Add methods to initialise the config, set defaults
- [x] Add a resolve method
- [x] Make it separate from Hub
- [ ] Parse output into separate fields
- [ ] Test UDP6
- [x] Parse output into separate fields
- [ ] Test IPv6
- [x] Add DOH support
- [x] Add DOT support
- [x] Add DNS protocol on TCP mode support.
## CLI Features
- [ ] `digfile`
- [ ] `ndots` support
- [ ] `search path` support
- [ ] JSON output
- [ ] Colorized output
- [ ] Table output
- [x] `ndots` support
- [x] `search path` support
- [x] JSON output
- [x] Colorized output
- [x] Table output
## CLI Grunt
- [x] Query args
- [x] Neatly package them to load args in different functions
- [x] Upper case is not mandatory for query type/classes
- [ ] Output
- [ ] Add client transport options
- [x] Output
- [x] Add client transport options
## Tests

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@ -10,12 +10,11 @@ var (
// Version and date of the build. This is injected at build-time.
buildVersion = "unknown"
buildDate = "unknown"
verboseEnabled = false
)
func main() {
var (
logger = initLogger(verboseEnabled)
logger = initLogger()
app = cli.NewApp()
)
// Initialize hub.
@ -88,6 +87,17 @@ func main() {
Usage: "Display how long it took for the response to arrive",
Destination: &hub.QueryFlags.DisplayTimeTaken,
},
&cli.BoolFlag{
Name: "search",
Usage: "Use the search list provided in resolv.conf. It sets the `ndots` parameter as well unless overriden by `ndots` flag.",
Destination: &hub.QueryFlags.UseSearchList,
},
&cli.IntFlag{
Name: "ndots",
Usage: "Specify the ndots paramter",
DefaultText: "Default value is that set in `/etc/resolv.conf` or 1 if no `ndots` statement is present.",
Destination: &hub.QueryFlags.Ndots,
},
&cli.BoolFlag{
Name: "json",
Aliases: []string{"J"},
@ -95,13 +105,12 @@ func main() {
Destination: &hub.QueryFlags.ShowJSON,
},
&cli.BoolFlag{
Name: "verbose",
Name: "debug",
Usage: "Enable verbose logging",
Destination: &verboseEnabled,
Destination: &hub.QueryFlags.Verbose,
DefaultText: "false",
},
}
app.Before = hub.loadQueryArgs
app.Action = func(c *cli.Context) error {
if len(hub.QueryFlags.QNames.Value()) == 0 {
@ -110,6 +119,7 @@ func main() {
hub.Lookup(c)
return nil
}
// Run the app.
hub.Logger.Debug("Starting doggo...")
err := app.Run(os.Args)

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@ -14,6 +14,7 @@ type Hub struct {
QueryFlags QueryFlags
Questions []dns.Question
Resolver resolvers.Resolver
cliContext *cli.Context
}
// QueryFlags is used store the value of CLI flags.
@ -30,6 +31,9 @@ type QueryFlags struct {
UseIPv6 bool
DisplayTimeTaken bool
ShowJSON bool
Verbose bool
UseSearchList bool
Ndots int
}
// NewHub initializes an instance of Hub which holds app wide configuration.
@ -49,18 +53,11 @@ func NewHub(logger *logrus.Logger, buildVersion string) *Hub {
}
// initLogger initializes logger
func initLogger(verbose bool) *logrus.Logger {
func initLogger() *logrus.Logger {
logger := logrus.New()
logger.SetFormatter(&logrus.TextFormatter{
DisableTimestamp: true,
DisableLevelTruncation: true,
})
// Set logger level
if verbose {
logger.SetLevel(logrus.DebugLevel)
logger.Debug("verbose logging enabled")
} else {
logger.SetLevel(logrus.InfoLevel)
}
return logger
}

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@ -4,12 +4,17 @@ import (
"strings"
"github.com/miekg/dns"
"github.com/mr-karan/doggo/pkg/resolvers"
"github.com/sirupsen/logrus"
"github.com/urfave/cli/v2"
)
// Lookup sends the DNS queries to the server.
func (hub *Hub) Lookup(c *cli.Context) error {
hub.prepareQuestions()
err := hub.prepareQuestions()
if err != nil {
return err
}
responses, err := hub.Resolver.Lookup(hub.Questions)
if err != nil {
return err
@ -21,10 +26,34 @@ func (hub *Hub) Lookup(c *cli.Context) error {
// prepareQuestions iterates on list of domain names
// and prepare a list of questions
// sent to the server with all possible combinations.
func (hub *Hub) prepareQuestions() {
var question dns.Question
func (hub *Hub) prepareQuestions() error {
var (
question dns.Question
)
for _, name := range hub.QueryFlags.QNames.Value() {
question.Name = dns.Fqdn(name)
var (
domains []string
ndots int
)
// If `search` flag is specified then fetch the search list
// from `resolv.conf` and set the
if hub.QueryFlags.UseSearchList {
list, n, err := fetchDomainList(name, hub.cliContext.IsSet("ndots"), hub.QueryFlags.Ndots)
if err != nil {
return err
}
domains = list
ndots = n
} else {
domains = []string{dns.Fqdn(name)}
}
for _, d := range domains {
hub.Logger.WithFields(logrus.Fields{
"domain": d,
"ndots": ndots,
}).Debug("Attmepting to resolve")
question.Name = d
// iterate on a list of query types.
for _, q := range hub.QueryFlags.QTypes.Value() {
question.Qtype = dns.StringToType[strings.ToUpper(q)]
@ -36,4 +65,18 @@ func (hub *Hub) prepareQuestions() {
}
}
}
}
return nil
}
func fetchDomainList(d string, isNdotsSet bool, ndots int) ([]string, int, error) {
cfg, err := dns.ClientConfigFromFile(resolvers.DefaultResolvConfPath)
if err != nil {
return nil, 0, err
}
// if user specified a custom ndots parameter, override it
if isNdotsSet {
cfg.Ndots = ndots
}
return cfg.NameList(d), cfg.Ndots, nil
}

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@ -20,6 +20,7 @@ type Output struct {
TTL string `json:"ttl"`
Address string `json:"address"`
TimeTaken string `json:"rtt"`
Nameserver string `json:"nameserver"`
}
type Query struct {
@ -119,6 +120,7 @@ func collectOutput(responses []resolvers.Response) []Output {
Class: qclass,
Address: addr,
TimeTaken: rtt,
Nameserver: r.Nameserver,
}
out = append(out, o)
}

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@ -4,10 +4,20 @@ import (
"strings"
"github.com/miekg/dns"
"github.com/sirupsen/logrus"
"github.com/urfave/cli/v2"
)
func (hub *Hub) loadQueryArgs(c *cli.Context) error {
// set log level
if c.Bool("debug") {
// Set logger level
hub.Logger.SetLevel(logrus.DebugLevel)
} else {
hub.Logger.SetLevel(logrus.InfoLevel)
}
hub.cliContext = c
err := hub.loadFreeArgs(c)
if err != nil {
cli.Exit("Error parsing arguments", -1)

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@ -23,7 +23,7 @@ func (hub *Hub) initResolver(c *cli.Context) error {
if runtime.GOOS == "windows" {
// TODO: Add a method for reading system default nameserver in windows.
} else {
rslvr, err := resolvers.NewResolverFromResolvFile(resolvers.DefaultResolvConfPath)
rslvr, err := resolvers.NewSystemResolver(resolvers.DefaultResolvConfPath)
if err != nil {
return err
}

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@ -1,7 +1,6 @@
package resolvers
import (
"fmt"
"net"
"github.com/miekg/dns"
@ -47,6 +46,7 @@ func NewClassicResolver(servers []string, opts ClassicResolverOpts) (Resolver, e
nameservers = append(nameservers, srv)
}
}
client.Net = "udp"
if opts.UseIPv4 {
client.Net = "udp4"
@ -66,35 +66,6 @@ func NewClassicResolver(servers []string, opts ClassicResolverOpts) (Resolver, e
}, nil
}
// NewResolverFromResolvFile loads the configuration from resolv config file
// and initialises a DNS resolver.
func NewResolverFromResolvFile(resolvFilePath string) (Resolver, error) {
if resolvFilePath == "" {
resolvFilePath = DefaultResolvConfPath
}
cfg, err := dns.ClientConfigFromFile(resolvFilePath)
if err != nil {
return nil, err
}
servers := make([]string, 0, len(cfg.Servers))
for _, s := range cfg.Servers {
ip := net.ParseIP(s)
// handle IPv6
if ip != nil && ip.To4() != nil {
servers = append(servers, fmt.Sprintf("%s:%s", s, cfg.Port))
} else {
servers = append(servers, fmt.Sprintf("[%s]:%s", s, cfg.Port))
}
}
client := &dns.Client{}
return &ClassicResolver{
client: client,
servers: servers,
}, nil
}
// Lookup prepare a list of DNS messages to be sent to the server.
// It's possible to send multiple question in one message
// but some nameservers are not able to

View File

@ -26,7 +26,7 @@ func NewDOHResolver(servers []string) (Resolver, error) {
}, nil
}
func (r *DOHResolver) Lookup(questions []dns.Question) ([]Response, error) {
func (d *DOHResolver) Lookup(questions []dns.Question) ([]Response, error) {
var (
messages = prepareMessages(questions)
responses []Response
@ -38,10 +38,10 @@ func (r *DOHResolver) Lookup(questions []dns.Question) ([]Response, error) {
if err != nil {
return nil, err
}
for _, srv := range r.servers {
for _, srv := range d.servers {
now := time.Now()
// Make an HTTP POST request to the DNS server with the DNS message as wire format bytes in the body.
resp, err := r.client.Post(srv, "application/dns-message", bytes.NewBuffer(b))
resp, err := d.client.Post(srv, "application/dns-message", bytes.NewBuffer(b))
if err != nil {
return nil, err
}

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@ -0,0 +1,84 @@
package resolvers
import (
"fmt"
"net"
"github.com/miekg/dns"
)
// SystemResolver represents the config options based on the
// resolvconf file.
type SystemResolver struct {
client *dns.Client
config *dns.ClientConfig
servers []string
}
// NewSystemResolver loads the configuration from resolv config file
// and initialises a DNS resolver.
func NewSystemResolver(resolvFilePath string) (Resolver, error) {
if resolvFilePath == "" {
resolvFilePath = DefaultResolvConfPath
}
cfg, err := dns.ClientConfigFromFile(resolvFilePath)
if err != nil {
return nil, err
}
servers := make([]string, 0, len(cfg.Servers))
for _, s := range cfg.Servers {
ip := net.ParseIP(s)
// handle IPv6
if ip != nil && ip.To4() != nil {
servers = append(servers, fmt.Sprintf("%s:%s", s, cfg.Port))
} else {
servers = append(servers, fmt.Sprintf("[%s]:%s", s, cfg.Port))
}
}
client := &dns.Client{}
return &SystemResolver{
client: client,
servers: servers,
config: cfg,
}, nil
}
// Lookup prepare a list of DNS messages to be sent to the server.
// It's possible to send multiple question in one message
// but some nameservers are not able to
func (s *SystemResolver) Lookup(questions []dns.Question) ([]Response, error) {
for _, q := range questions {
domains := s.config.NameList(q.Name)
for _, d := range domains {
ques := dns.Question{
Name: d,
Qtype: q.Qtype,
Qclass: q.Qclass,
}
questions = append(questions, ques)
}
}
var (
messages = prepareMessages(questions)
responses []Response
)
for _, msg := range messages {
for _, srv := range s.servers {
in, rtt, err := s.client.Exchange(&msg, srv)
if err != nil {
return nil, err
}
msg.Answer = in.Answer
rsp := Response{
Message: msg,
RTT: rtt,
Nameserver: srv,
}
responses = append(responses, rsp)
}
}
return responses, nil
}