mix
8ce050ef7f
Initial feature-complete implementation of the v1.0 specification (phases 0-11 of `docs/implementation-plan.md`). Added: - Panel (Go, single static binary) with SQLite persistence, one-time - Domain management with per-domain DKIM (RSA-2048, generated in pure Go) and - Application (sender identity) management: SASL credentials via `sasldb2`, - Full Postfix relay config generated from env at container start: SMTPS 465, - Journal milter (pure Go, `go-milter`) recording every send to `send_log`; … (6 more in CHANGELOG) Full detail: CHANGELOG.md (0.1.0).
90 lines
2.7 KiB
Go
90 lines
2.7 KiB
Go
package dnscheck
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import (
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"context"
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"fmt"
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"time"
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"codeberg.org/mix/selfpost/internal/health"
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)
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// checkServer resolves the panel's own hostname and confirms the reverse
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// lookup of each address points back at that name (FCrDNS). A missing or
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// mismatched PTR is the single most common reason mail from a self-hosted
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// server is rejected or scored as spam, which is why it is an error and not
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// advice.
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func (c *Checker) checkServer(ctx context.Context, hostname string) Server {
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srv := Server{Hostname: hostname, CheckedAt: time.Now()}
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if hostname == "" {
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srv.PTR = Result{
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Status: health.StatusUnknown,
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Detail: "SELFPOST_HOSTNAME is not set, so the server's own name in DNS cannot be checked. Set it in the deployment environment.",
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}
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return srv
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}
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addrs, err := c.resolver.LookupIPAddr(ctx, hostname)
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if err != nil || len(addrs) == 0 {
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srv.PTR = Result{
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Status: health.StatusError,
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Detail: fmt.Sprintf("%s does not resolve to any address. Publish an A (or AAAA) record for it — receiving servers check the name this server announces in HELO.", hostname),
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}
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return srv
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}
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want := normalizeName(hostname)
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matched, total := 0, len(addrs)
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var records []string
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for _, a := range addrs {
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ip := a.IP.String()
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srv.IPs = append(srv.IPs, ip)
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names, err := c.resolver.LookupAddr(ctx, ip)
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if err != nil || len(names) == 0 {
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records = append(records, ip+" → no PTR record")
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continue
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}
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hit := false
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for _, n := range names {
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if normalizeName(n) == want {
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hit = true
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}
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}
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if hit {
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matched++
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records = append(records, ip+" → "+normalizeName(names[0]))
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} else {
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records = append(records, ip+" → "+normalizeName(names[0])+" (does not match)")
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}
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}
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srv.PTR.Records = records
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switch {
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case matched == total:
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srv.PTR.Status = health.StatusOK
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srv.PTR.Detail = fmt.Sprintf("%s resolves to %s and the reverse lookup points back at it.", hostname, joinIPs(srv.IPs))
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case matched > 0:
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srv.PTR.Status = health.StatusWarn
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srv.PTR.Detail = fmt.Sprintf("Only %d of %d addresses of %s have a matching PTR record. Mail sent from the others may be rejected — set the reverse DNS of every address at your hosting provider.", matched, total, hostname)
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default:
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srv.PTR.Status = health.StatusError
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srv.PTR.Detail = fmt.Sprintf("No address of %s has a reverse (PTR) record pointing back at it. Many receiving servers reject or spam-score mail from such a host — set the reverse DNS of the server's IP to %s at your hosting provider.", hostname, hostname)
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}
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return srv
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}
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func joinIPs(ips []string) string {
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switch len(ips) {
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case 0:
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return "no address"
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case 1:
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return ips[0]
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default:
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out := ips[0]
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for _, ip := range ips[1:] {
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out += ", " + ip
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}
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return out
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}
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}
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