72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
package resolver
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import (
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"context"
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"net"
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"github.com/ooni/probe-cli/v3/internal/engine/netx/errorx"
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"github.com/ooni/probe-cli/v3/internal/engine/runtimex"
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)
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var privateIPBlocks []*net.IPNet
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func init() {
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for _, cidr := range []string{
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"0.0.0.0/8", // "This" network (however, Linux...)
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"10.0.0.0/8", // RFC1918
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"100.64.0.0/10", // Carrier grade NAT
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"127.0.0.0/8", // IPv4 loopback
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"169.254.0.0/16", // RFC3927 link-local
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"172.16.0.0/12", // RFC1918
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"192.168.0.0/16", // RFC1918
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"224.0.0.0/4", // Multicast
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"::1/128", // IPv6 loopback
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"fe80::/10", // IPv6 link-local
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"fc00::/7", // IPv6 unique local addr
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} {
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_, block, err := net.ParseCIDR(cidr)
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runtimex.PanicOnError(err, "net.ParseCIDR failed")
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privateIPBlocks = append(privateIPBlocks, block)
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}
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}
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func isPrivate(ip net.IP) bool {
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if ip.IsLoopback() || ip.IsLinkLocalUnicast() || ip.IsLinkLocalMulticast() {
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return true
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}
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for _, block := range privateIPBlocks {
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if block.Contains(ip) {
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return true
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}
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}
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return false
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}
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// IsBogon returns whether if an IP address is bogon. Passing to this
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// function a non-IP address causes it to return bogon.
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func IsBogon(address string) bool {
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ip := net.ParseIP(address)
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return ip == nil || isPrivate(ip)
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}
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// BogonResolver is a bogon aware resolver. When a bogon is encountered in
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// a reply, this resolver will return an error.
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type BogonResolver struct {
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Resolver
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}
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// LookupHost implements Resolver.LookupHost
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func (r BogonResolver) LookupHost(ctx context.Context, hostname string) ([]string, error) {
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addrs, err := r.Resolver.LookupHost(ctx, hostname)
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for _, addr := range addrs {
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if IsBogon(addr) == true {
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// We need to return the addrs otherwise the caller cannot see/log/save
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// the specific addresses that triggered our bogon filter
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return addrs, errorx.ErrDNSBogon
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}
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}
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return addrs, err
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}
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var _ Resolver = BogonResolver{}
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