Pierre-Olivier Mercier
90f1b4943f
Generic SRV records checker for happyDomain.
For each SRV record attached to an svcs.UnknownSRV service, the checker
resolves every target and probes reachability:
- DNS resolution (A/AAAA), CNAME detection (RFC 2782 violation),
null-target detection (RFC 2782 "service explicitly unavailable")
- TCP connect to target:port for _tcp SRVs
- UDP probe for _udp SRVs, using ICMP port-unreachable detection
The checker also publishes TLS endpoints (host, port, SNI) for every
SRV target hitting a well-known direct-TLS port (443, 465, 636, 853,
993, 995, 5061, 5223, …) via the EndpointDiscoverer SDK interface, so
a downstream TLS checker can pick them up.
The HTML report groups records as cards and surfaces the most common
failure scenarios (DNS failure, CNAME target, TCP unreachable,
null-target) at the top with remediation guidance.
65 lines
2.2 KiB
Go
65 lines
2.2 KiB
Go
// This file is part of the happyDomain (R) project.
|
|
// Copyright (c) 2020-2026 happyDomain
|
|
// Authors: Pierre-Olivier Mercier, et al.
|
|
//
|
|
// This program is offered under a commercial and under the AGPL license.
|
|
// For commercial licensing, contact us at <contact@happydomain.org>.
|
|
//
|
|
// For AGPL licensing:
|
|
// This program is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Affero General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Affero General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Affero General Public License
|
|
// along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
package checker
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"strings"
|
|
|
|
sdk "git.happydns.org/checker-sdk-go/checker"
|
|
)
|
|
|
|
type ruleTargetsResolve struct{}
|
|
|
|
func RuleTargetsResolve() sdk.CheckRule { return &ruleTargetsResolve{} }
|
|
func (ruleTargetsResolve) Name() string { return "srv_targets_resolve" }
|
|
func (ruleTargetsResolve) Description() string {
|
|
return "Every SRV target resolves to at least one A/AAAA address."
|
|
}
|
|
func (ruleTargetsResolve) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
|
|
d, cs := getData(ctx, obs)
|
|
if cs != nil {
|
|
return []sdk.CheckState{*cs}
|
|
}
|
|
var failed []string
|
|
var checked int
|
|
for _, r := range d.Records {
|
|
if r.IsNullTarget {
|
|
continue
|
|
}
|
|
checked++
|
|
if len(r.Addresses) == 0 {
|
|
failed = append(failed, fmt.Sprintf("%s (%s)", r.Target, r.ResolveError))
|
|
}
|
|
}
|
|
if checked == 0 {
|
|
return []sdk.CheckState{{Status: sdk.StatusUnknown, Code: "srv_no_targets",
|
|
Message: "No resolvable targets to test."}}
|
|
}
|
|
if len(failed) == 0 {
|
|
return []sdk.CheckState{{Status: sdk.StatusOK, Code: "srv_all_resolve",
|
|
Message: fmt.Sprintf("All %d target(s) resolve.", checked)}}
|
|
}
|
|
return []sdk.CheckState{{Status: sdk.StatusCrit, Code: "srv_resolve_fail",
|
|
Message: fmt.Sprintf("Target(s) failed DNS resolution: %s", strings.Join(failed, "; "))}}
|
|
}
|