mirror of https://github.com/gogs/gogs.git
72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
// Copyright 2022 The Gogs Authors. All rights reserved.
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// Use of this source code is governed by a MIT-style
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// license that can be found in the LICENSE file.
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package netutil
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import (
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"fmt"
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"net"
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)
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var localCIDRs []*net.IPNet
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func init() {
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// Parsing hardcoded CIDR strings should never fail, if in case it does, let's
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// fail it at start.
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rawCIDRs := []string{
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// https://datatracker.ietf.org/doc/html/rfc5735:
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"127.0.0.0/8", // Loopback
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"0.0.0.0/8", // "This" network
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"100.64.0.0/10", // Shared address space
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"169.254.0.0/16", // Link local
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"172.16.0.0/12", // Private-use networks
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"192.0.0.0/24", // IETF Protocol assignments
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"192.0.2.0/24", // TEST-NET-1
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"192.88.99.0/24", // 6to4 Relay anycast
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"192.168.0.0/16", // Private-use networks
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"198.18.0.0/15", // Network interconnect
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"198.51.100.0/24", // TEST-NET-2
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"203.0.113.0/24", // TEST-NET-3
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"255.255.255.255/32", // Limited broadcast
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// https://datatracker.ietf.org/doc/html/rfc1918:
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"10.0.0.0/8", // Private-use networks
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// https://datatracker.ietf.org/doc/html/rfc6890:
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"::1/128", // Loopback
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"FC00::/7", // Unique local address
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"FE80::/10", // Multicast address
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}
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for _, raw := range rawCIDRs {
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_, cidr, err := net.ParseCIDR(raw)
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if err != nil {
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panic(fmt.Sprintf("parse CIDR %q: %v", raw, err))
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}
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localCIDRs = append(localCIDRs, cidr)
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}
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}
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// IsLocalHostname returns true if given hostname is resolved to local network
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// address, except exempted from the allowlist.
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func IsLocalHostname(hostname string, allowlist []string) bool {
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for _, allow := range allowlist {
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if hostname == allow {
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return false
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}
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}
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ips, err := net.LookupIP(hostname)
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if err != nil {
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return true
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}
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for _, ip := range ips {
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for _, cidr := range localCIDRs {
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if cidr.Contains(ip) {
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return true
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}
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}
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}
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return false
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}
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