NotAShelf
ffb4ab2295
Signed-off-by: NotAShelf <raf@notashelf.dev> Change-Id: Iaf89cda3c480d6a8371e5f146ee95fcf6a6a6964
98 lines
2.6 KiB
Go
98 lines
2.6 KiB
Go
package normalize
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import (
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"net/url"
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"strings"
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"golang.org/x/net/publicsuffix"
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)
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// Returns true for localhost, loopback IPs, and private IPs.
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func isInternalHost(hostname string) bool {
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if hostname == "" {
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return false
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}
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// Localhost variants
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if hostname == "localhost" ||
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strings.HasPrefix(hostname, "localhost.") ||
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strings.HasPrefix(hostname, "127.") ||
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hostname == "::1" {
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return true
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}
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// Private IPv4 ranges (RFC1918)
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if strings.HasPrefix(hostname, "10.") ||
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strings.HasPrefix(hostname, "192.168.") ||
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strings.HasPrefix(hostname, "172.16.") ||
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strings.HasPrefix(hostname, "172.17.") ||
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strings.HasPrefix(hostname, "172.18.") ||
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strings.HasPrefix(hostname, "172.19.") ||
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strings.HasPrefix(hostname, "172.20.") ||
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strings.HasPrefix(hostname, "172.21.") ||
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strings.HasPrefix(hostname, "172.22.") ||
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strings.HasPrefix(hostname, "172.23.") ||
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strings.HasPrefix(hostname, "172.24.") ||
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strings.HasPrefix(hostname, "172.25.") ||
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strings.HasPrefix(hostname, "172.26.") ||
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strings.HasPrefix(hostname, "172.27.") ||
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strings.HasPrefix(hostname, "172.28.") ||
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strings.HasPrefix(hostname, "172.29.") ||
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strings.HasPrefix(hostname, "172.30.") ||
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strings.HasPrefix(hostname, "172.31.") {
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return true
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}
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// IPv6 loopback and local
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if strings.HasPrefix(hostname, "::1") ||
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strings.HasPrefix(hostname, "fe80::") ||
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strings.HasPrefix(hostname, "fc00::") ||
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strings.HasPrefix(hostname, "fd00::") {
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return true
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}
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return false
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}
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// Extracts the eTLD+1 domain from a referrer URL.
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// Returns "direct" for empty or same-domain referrers.
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// Returns empty string for invalid URLs.
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func ExtractReferrerDomain(referrer, siteDomain string) string {
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if referrer == "" {
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return "direct"
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}
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u, err := url.Parse(referrer)
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if err != nil {
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return ""
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}
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hostname := strings.ToLower(u.Hostname())
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hostname = strings.TrimSuffix(hostname, ".") // remove trailing dot
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if hostname == "" {
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return ""
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}
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// Check for internal/localhost traffic
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if isInternalHost(hostname) {
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return "internal"
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}
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// Same domain check
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siteDomainLower := strings.ToLower(siteDomain)
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if hostname == siteDomainLower || strings.HasSuffix(hostname, "."+siteDomainLower) {
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return "direct"
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}
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// Extract eTLD+1 (effective top-level domain + 1 label); e.g.
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// - "www.google.co.uk" -> "google.co.uk"
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// - "news.ycombinator.com" -> "ycombinator.com"
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eTLDPlus1, err := publicsuffix.EffectiveTLDPlusOne(hostname)
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if err != nil {
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// If public suffix lookup fails (malformed/unknown TLD), return "other"
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// to prevent unbounded cardinality from malicious referrers
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return "other"
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}
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return eTLDPlus1
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}
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