Merge pull request #6 from projectdiscovery/feature-syscall-support

adding support for syscalls
projectdiscovery · Feb 24, 2021 · afa9845 · afa9845
2 parents 2448775 + 6fb8195
commit afa9845
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Showing 5 changed files with 30 additions and 11 deletions.
diff --git a/fastdialer/dialer.go b/fastdialer/dialer.go
@@ -15,6 +15,7 @@ import (
 
 // Dialer structure containing data information
 type Dialer struct {
+	options       *Options
 	dnsclient     *retryabledns.Client
 	hm            *hybrid.HybridMap
 	dialerHistory *hybrid.HybridMap
@@ -45,7 +46,7 @@ func NewDialer(options Options) (*Dialer, error) {
 		loadHostsFile(hm)
 	}
 
-	return &Dialer{dnsclient: dnsclient, hm: hm, dialerHistory: dialerHistory, dialer: dialer}, nil
+	return &Dialer{dnsclient: dnsclient, hm: hm, dialerHistory: dialerHistory, dialer: dialer, options: &options}, nil
 }
 
 // Dial function compatible with net/http
@@ -141,6 +142,9 @@ func (d *Dialer) GetDNSData(hostname string) (*retryabledns.DNSData, error) {
 	data, err = d.GetDNSDataFromCache(hostname)
 	if err != nil {
 		data, err = d.dnsclient.Resolve(hostname)
+		if d.options.EnableFallback {
+			data, err = d.dnsclient.ResolveWithSyscall(hostname)
+		}
 		if err != nil {
 			return nil, err
 		}

diff --git a/fastdialer/hostsfile.go b/fastdialer/hostsfile.go
@@ -25,20 +25,34 @@ func loadHostsFile(hm *hybrid.HybridMap) error {
 	}
 	defer file.Close()
 
+	dnsDatas := make(map[string]retryabledns.DNSData)
 	scanner := bufio.NewScanner(utfbom.SkipOnly(file))
 	for scanner.Scan() {
 		ip, hosts := HandleLine(scanner.Text())
 		if ip == "" || len(hosts) == 0 {
 			continue
 		}
+		netIP := net.ParseIP(ip)
+		isiPv4 := netIP.To4() != nil
+		isIPv6 := netIP.To16() != nil
 		for _, host := range hosts {
-			dnsdata := retryabledns.DNSData{Host: host, A: []string{ip}}
-			dnsdataBytes, _ := dnsdata.Marshal()
-			// nolint:errcheck // if they cannot be cached it's not a hard failure
-			hm.Set(host, dnsdataBytes)
+			dnsdata, ok := dnsDatas[host]
+			if !ok {
+				dnsdata = retryabledns.DNSData{Host: host}
+			}
+			if isiPv4 {
+				dnsdata.A = append(dnsdata.A, ip)
+			} else if isIPv6 {
+				dnsdata.A = append(dnsdata.AAAA, ip)
+			}
 		}
 	}
 
+	for host, dnsdata := range dnsDatas {
+		dnsdataBytes, _ := dnsdata.Marshal()
+		_ = hm.Set(host, dnsdataBytes)
+	}
+
 	return nil
 }
 

diff --git a/fastdialer/options.go b/fastdialer/options.go
@@ -9,9 +9,10 @@ var DefaultResolvers = []string{
 }
 
 type Options struct {
-	BaseResolvers []string
-	MaxRetries    int
-	HostsFile     bool
+	BaseResolvers  []string
+	MaxRetries     int
+	HostsFile      bool
+	EnableFallback bool
 }
 
 // DefaultOptions of the cache

diff --git a/go.mod b/go.mod
@@ -7,7 +7,7 @@ require (
 	github.com/golang/snappy v0.0.2 // indirect
 	github.com/miekg/dns v1.1.38 // indirect
 	github.com/projectdiscovery/hmap v0.0.1
-	github.com/projectdiscovery/retryabledns v1.0.6
+	github.com/projectdiscovery/retryabledns v1.0.7
 	github.com/stretchr/testify v1.7.0 // indirect
 	golang.org/x/crypto v0.0.0-20201221181555-eec23a3978ad // indirect
 	golang.org/x/net v0.0.0-20210119194325-5f4716e94777 // indirect

diff --git a/go.sum b/go.sum
@@ -25,8 +25,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/projectdiscovery/hmap v0.0.1 h1:VAONbJw5jP+syI5smhsfkrq9XPGn4aiYy5pR6KR1wog=
 github.com/projectdiscovery/hmap v0.0.1/go.mod h1:VDEfgzkKQdq7iGTKz8Ooul0NuYHQ8qiDs6r8bPD1Sb0=
-github.com/projectdiscovery/retryabledns v1.0.6 h1:fz33puVeUKJJ5s2POSlxO4WA4iodW6Yzm/EVNuO/93w=
-github.com/projectdiscovery/retryabledns v1.0.6/go.mod h1:/UzJn4I+cPdQl6pKiiQfvVAT636YZvJQYZhYhGB0dUQ=
+github.com/projectdiscovery/retryabledns v1.0.7 h1:fwbwrl+0XmWRvwiNzm/YSBjmUh7KwIsryScUK9juOuA=
+github.com/projectdiscovery/retryabledns v1.0.7/go.mod h1:/UzJn4I+cPdQl6pKiiQfvVAT636YZvJQYZhYhGB0dUQ=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=