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// marque: the DNS zones of the domains an account registered through Marque (marque.at).
//
// A domain is an at.marque.domain record in the account's own repo, keyed by the FQDN. Its zone is ONE
// at.marque.dns record with the same key: { domain, subject (strongRef to the domain record), records,
// createdAt }. Marque's nameserver serves what that public record says, so an edit is a repo write:
// read both records, change the zone's records list, put it back with swapRecord (a concurrent edit
// fails instead of being lost).
//
// Entries (step protocol):
// list_domains -> listRecords at.marque.domain (paged) -> the account's domains
// list_records -> getRecord domain + zone -> the zone's records
// create_record -> getRecord domain + zone -> put/createRecord -> the zone with one record added
// update_record -> getRecord domain + zone -> putRecord -> one record changed
// delete_record -> getRecord domain + zone -> putRecord -> one record removed
use std::net::{Ipv4Addr, Ipv6Addr};
use abi::repo::{self, CREATE_RECORD, PUT_RECORD, get_record};
use abi::{AtUri, Call, Datetime, Did, Event, Handle, Run, entries};
use serde::Deserialize;
use serde_json::{Value, json};
const DOMAIN: &str = "at.marque.domain";
const DNS: &str = "at.marque.dns";
const PAGE_LIMIT: usize = 100;
const TYPES: [&str; 8] = ["A", "AAAA", "CNAME", "MX", "TXT", "SRV", "NS", "CAA"];
const DEFAULT_TTL: i64 = 3600;
#[derive(Deserialize)]
struct Args {
did: Did,
now: String,
#[serde(default)]
domain: Option<String>,
#[serde(default)]
name: Option<String>,
#[serde(default, rename = "type")]
kind: Option<String>,
#[serde(default)]
value: Option<String>,
#[serde(default)]
ttl: Option<Value>,
#[serde(default)]
priority: Option<Value>,
#[serde(default, rename = "newName")]
new_name: Option<String>,
#[serde(default, rename = "newValue")]
new_value: Option<String>,
}
#[derive(Clone, Copy, PartialEq)]
enum Action {
List,
Create,
Update,
Delete,
}
// --- validation -------------------------------------------------------------------------------
fn label_ok(label: &str) -> bool {
(1..=63).contains(&label.len())
&& label.chars().all(|c| c.is_ascii_lowercase() || c.is_ascii_digit() || c == '-' || c == '_')
&& !label.starts_with('-')
&& !label.ends_with('-')
}
// A hostname: lowercase, one trailing dot dropped (Marque stores names without it).
fn host(value: &str, what: &str) -> Result<String, String> {
let host = value.trim().to_ascii_lowercase();
let host = host.strip_suffix('.').unwrap_or(&host).to_string();
if host.is_empty() || host.len() > 253 || !host.split('.').all(label_ok) {
return Err(format!("{what} must be a hostname like mail.example.com, got {value:?}"));
}
Ok(host)
}
fn target(value: &str, what: &str) -> Result<String, String> {
if value.trim() == "." { Ok(".".into()) } else { host(value, what) }
}
fn domain_arg(domain: Option<&str>) -> Result<String, String> {
let domain = host(domain.unwrap_or_default(), "domain")?;
if !domain.contains('.') {
return Err("domain must be a registered domain like example.com".into());
}
Ok(domain)
}
// A name relative to the zone: "@" for the apex, else labels ("www", "_atproto", "*.app").
fn record_name(name: &str, domain: &str, kind: &str) -> Result<String, String> {
let name = name.trim().to_ascii_lowercase();
if name == "@" {
if kind == "NS" {
return Err("NS records at @ are the domain's nameservers: change those in Marque's domain settings".into());
}
return Ok(name);
}
let labels: Vec<&str> = name.split('.').collect();
let wildcard = labels[0] == "*";
if name.is_empty() || name.ends_with('.') || !labels.iter().skip(usize::from(wildcard)).all(|l| label_ok(l)) {
return Err(format!("name must be @ or a name relative to {domain}, like www, _atproto or *.app (no trailing dot), got {name:?}"));
}
if name.len() + 1 + domain.len() > 253 {
return Err(format!("{name}.{domain} is longer than 253 characters"));
}
if kind == "SRV" && !(labels.len() >= 2 && labels[0].starts_with('_') && labels[1].starts_with('_')) {
return Err("SRV name must start with _service._proto, like _sip._tcp".into());
}
Ok(name)
}
fn number(value: &str, what: &str, max: u32) -> Result<u32, String> {
value.parse::<u32>().ok().filter(|n| *n <= max).ok_or_else(|| format!("{what} must be a number from 0 to {max}, got {value:?}"))
}
fn printable(value: &str, what: &str) -> Result<(), String> {
if value.chars().any(char::is_control) { Err(format!("{what} must not contain control characters")) } else { Ok(()) }
}
// The value as Marque stores it, per type.
fn record_value(kind: &str, value: &str) -> Result<String, String> {
let trimmed = value.trim();
match kind {
"A" => trimmed.parse::<Ipv4Addr>().map(|ip| ip.to_string()).map_err(|_| format!("A value must be an IPv4 address, got {value:?}")),
"AAAA" => trimmed.parse::<Ipv6Addr>().map(|ip| ip.to_string()).map_err(|_| format!("AAAA value must be an IPv6 address, got {value:?}")),
"CNAME" | "NS" => host(value, &format!("{kind} value")),
"MX" => target(value, "MX value"),
"TXT" => {
printable(value, "TXT value")?;
if value.is_empty() || value.len() > 4096 {
return Err("TXT value must be 1 to 4096 bytes".into());
}
Ok(value.to_string())
}
// weight port target; priority is its own field, as for MX.
"SRV" => match trimmed.split_whitespace().collect::<Vec<_>>()[..] {
[weight, port, to] => Ok(format!("{} {} {}", number(weight, "SRV weight", 65535)?, number(port, "SRV port", 65535)?, target(to, "SRV target")?)),
_ => Err(format!("SRV value must be \"weight port target\", like 5 5060 sip.example.com, got {value:?}")),
},
// flags tag value: 0 issue "letsencrypt.org"
"CAA" => match trimmed.splitn(3, ' ').collect::<Vec<_>>()[..] {
[flags, tag, v] if !v.trim().is_empty() && (1..=15).contains(&tag.len()) && tag.chars().all(|c| c.is_ascii_alphanumeric()) => {
printable(v, "CAA value")?;
Ok(format!("{} {} {}", number(flags, "CAA flags", 255)?, tag.to_ascii_lowercase(), v.trim()))
}
_ => Err(format!("CAA value must be \"flags tag value\", like 0 issue \"letsencrypt.org\", got {value:?}")),
},
_ => Err(format!("type must be one of {}", TYPES.join(", "))),
}
}
fn kind_arg(kind: Option<&str>) -> Result<String, String> {
let kind = kind.unwrap_or_default().trim().to_ascii_uppercase();
if TYPES.contains(&kind.as_str()) { Ok(kind) } else { Err(format!("type must be one of {}", TYPES.join(", "))) }
}
// Form fields arrive as strings, JSON callers send numbers: take either. Blank is absent.
fn int(value: Option<&Value>, what: &str) -> Result<Option<i64>, String> {
match value {
None | Some(Value::Null) => Ok(None),
Some(Value::Number(n)) => n.as_i64().map(Some).ok_or_else(|| format!("{what} must be a whole number")),
Some(Value::String(s)) if s.trim().is_empty() => Ok(None),
Some(Value::String(s)) => s.trim().parse().map(Some).map_err(|_| format!("{what} must be a whole number, got {s:?}")),
Some(other) => Err(format!("{what} must be a whole number, got {other}")),
}
}
// One at.marque.dns#entry, checked.
fn entry(domain: &str, name: &str, kind: &str, value: &str, ttl: Option<i64>, priority: Option<i64>) -> Result<Value, String> {
let name = record_name(name, domain, kind)?;
let value = record_value(kind, value)?;
if value.len() > 4096 {
return Err("value must be at most 4096 bytes".into());
}
let ttl = ttl.unwrap_or(DEFAULT_TTL);
if !(1..=i64::from(i32::MAX)).contains(&ttl) {
return Err(format!("ttl must be from 1 to {} seconds", i32::MAX));
}
let mut out = json!({ "name": name, "recordType": kind, "value": value, "ttl": ttl });
match (kind, priority) {
("MX" | "SRV", Some(p)) if (0..=65535).contains(&p) => out["priority"] = json!(p),
("MX" | "SRV", _) => return Err(format!("{kind} needs a priority from 0 to 65535")),
(_, Some(_)) => return Err(format!("{kind} records take no priority")),
_ => {}
}
Ok(out)
}
// --- the zone ---------------------------------------------------------------------------------
fn text(v: &Value, key: &str) -> String {
v[key].as_str().unwrap_or_default().to_string()
}
// Compare values as they would be stored; an existing value Marque wrote is taken as is if it does not parse.
fn same_record(r: &Value, name: &str, kind: &str, value: &str) -> bool {
let kind_r = text(r, "recordType").to_ascii_uppercase();
let value_r = text(r, "value");
text(r, "name").eq_ignore_ascii_case(name) && kind_r == kind && record_value(&kind_r, &value_r).unwrap_or(value_r) == value
}
// No exact duplicates, and a CNAME is the only record at its name (RFC 1034 3.6.2).
fn check_conflicts(records: &[Value], new: &Value) -> Result<(), String> {
let (name, kind, value) = (text(new, "name"), text(new, "recordType"), text(new, "value"));
for r in records.iter().filter(|r| text(r, "name").eq_ignore_ascii_case(&name)) {
if same_record(r, &name, &kind, &value) {
return Err(format!("{kind} {name} {value} already exists"));
}
if kind == "CNAME" || text(r, "recordType").eq_ignore_ascii_case("CNAME") {
return Err(format!("a CNAME cannot share the name {name} with any other record"));
}
}
Ok(())
}
// The record named by name, type and value (update and delete), as its index.
fn find(records: &[Value], args: &Args, domain: &str) -> Result<usize, String> {
let kind = kind_arg(args.kind.as_deref())?;
let name = record_name(args.name.as_deref().unwrap_or_default(), domain, "")?;
let raw = args.value.as_deref().unwrap_or_default();
let value = record_value(&kind, raw).unwrap_or_else(|_| raw.trim().to_string());
records
.iter()
.position(|r| same_record(r, &name, &kind, &value))
.ok_or_else(|| format!("no {kind} record {name} {value} in {domain}"))
}
// The checks that need no zone, so bad input fails before any call.
fn check_input(action: Action, args: &Args, domain: &str) -> Result<(), String> {
let kind = || kind_arg(args.kind.as_deref());
match action {
Action::Create => entry(domain, args.name.as_deref().unwrap_or_default(), &kind()?, args.value.as_deref().unwrap_or_default(), int(args.ttl.as_ref(), "ttl")?, int(args.priority.as_ref(), "priority")?).map(drop),
Action::Update | Action::Delete => {
kind()?;
record_name(args.name.as_deref().unwrap_or_default(), domain, "")?;
if args.value.as_deref().unwrap_or_default().trim().is_empty() {
return Err("value is required to say which record".into());
}
int(args.ttl.as_ref(), "ttl")?;
int(args.priority.as_ref(), "priority").map(drop)
}
Action::List => Ok(()),
}
}
// The zone's records after the action, and the record added, changed or removed.
fn apply(action: Action, mut records: Vec<Value>, args: &Args, domain: &str) -> Result<(Vec<Value>, Value), String> {
let ttl = int(args.ttl.as_ref(), "ttl")?;
let priority = int(args.priority.as_ref(), "priority")?;
match action {
Action::Create => {
let kind = kind_arg(args.kind.as_deref())?;
let new = entry(domain, args.name.as_deref().unwrap_or_default(), &kind, args.value.as_deref().unwrap_or_default(), ttl, priority)?;
check_conflicts(&records, &new)?;
records.push(new.clone());
Ok((records, new))
}
Action::Update => {
let at = find(&records, args, domain)?;
let old = records.remove(at);
let pick = |new: &Option<String>, key| new.as_deref().filter(|s| !s.trim().is_empty()).map(String::from).unwrap_or_else(|| text(&old, key));
let kind = text(&old, "recordType").to_ascii_uppercase();
let new = entry(domain, &pick(&args.new_name, "name"), &kind, &pick(&args.new_value, "value"), ttl.or(old["ttl"].as_i64()), priority.or(old["priority"].as_i64()))?;
check_conflicts(&records, &new)?;
records.insert(at, new.clone());
Ok((records, new))
}
Action::Delete => {
let at = find(&records, args, domain)?;
let old = records.remove(at);
Ok((records, old))
}
Action::List => Ok((records, Value::Null)),
}
}
// --- handlers ---------------------------------------------------------------------------------
fn list_page(did: &Did, cursor: Option<&str>) -> Call {
repo::list_records(did.as_str(), DOMAIN, PAGE_LIMIT, cursor).id("page").service(did.as_str())
}
fn list_domains_handler(run: Run<Args>) -> Result<Handle, String> {
let Run { event, state, args } = run;
Ok(match event {
Event::Start => Handle::new().call(list_page(&args.did, None)).state(json!({ "domains": [] })),
Event::Result { result, .. } => {
let output = result.output()?;
let mut domains = state["domains"].as_array().cloned().unwrap_or_default();
for record in output["records"].as_array().into_iter().flatten() {
let mut domain = record["value"].clone();
let Some(fields) = domain.as_object_mut() else { continue };
fields.remove("$type");
fields.insert("uri".into(), record["uri"].clone());
domains.push(domain);
}
match output["cursor"].as_str().filter(|c| !c.is_empty()) {
Some(cursor) => Handle::new().call(list_page(&args.did, Some(cursor))).state(json!({ "domains": domains })),
None => Handle::new().result(json!({ "domains": domains })).done(),
}
}
_ => Handle::new(),
})
}
// A getRecord's { uri, cid, value }, or null when the record does not exist.
fn got(result: &abi::CallResult) -> Result<Value, String> {
match result.output() {
Ok(o) => Ok(json!({ "uri": o["uri"], "cid": o["cid"], "value": o["value"] })),
Err(e) if e.contains("RecordNotFound") => Ok(Value::Null),
Err(e) => Err(e),
}
}
fn zone_handler(run: Run<Args>, action: Action) -> Result<Handle, String> {
let Run { event, mut state, args } = run;
let domain = domain_arg(args.domain.as_deref())?;
let did = args.did.as_str();
match event {
// Reads go to the account's own PDS (a public read), so listing works signed out too.
Event::Start => {
check_input(action, &args, &domain)?;
Ok(Handle::new()
.call(get_record(&AtUri::new(did, DOMAIN, &domain)).id("domain").service(did))
.call(get_record(&AtUri::new(did, DNS, &domain)).id("zone").service(did))
.state(json!({})))
}
Event::Result { id, result, .. } if id == "domain" || id == "zone" => {
state[id.as_str()] = got(&result)?;
let (Some(owned), Some(zone)) = (state.get("domain"), state.get("zone")) else { return Ok(Handle::new().state(state)) };
if owned.is_null() {
return Err(format!("{domain} is not a Marque domain of {did}: there is no at.marque.domain/{domain} record in its repo"));
}
let records = zone["value"]["records"].as_array().cloned().unwrap_or_default();
if action == Action::List {
return Ok(Handle::new().result(json!({ "domain": domain, "status": owned["value"]["status"], "uri": zone["uri"], "cid": zone["cid"], "records": records })).done());
}
let (records, changed) = apply(action, records, &args, &domain)?;
let now = Datetime::new(args.now).map_err(|e| format!("invalid now: {e}"))?;
let created_at = Datetime::try_from(now.to_utc()).map_err(|e| format!("invalid now: {e}"))?;
// Keep any fields Marque added to the zone; point subject at the domain record as it is now.
let mut record = if zone.is_null() { json!({ "$type": DNS }) } else { zone["value"].clone() };
record["domain"] = json!(domain);
record["subject"] = json!({ "uri": owned["uri"], "cid": owned["cid"] });
record["records"] = json!(records);
record["createdAt"] = json!(created_at);
let input = json!({ "repo": did, "collection": DNS, "rkey": domain, "record": record });
let call = if zone.is_null() {
Call::new("write", CREATE_RECORD).input(input)
} else {
let mut input = input;
input["swapRecord"] = zone["cid"].clone();
Call::new("write", PUT_RECORD).input(input)
};
let summary = json!({ "record": changed, "records": records.len() });
Ok(Handle::new().call(call).state(summary))
}
Event::Result { id, result, .. } if id == "write" => {
let written = result.output().map_err(|e| if e.contains("InvalidSwap") { format!("{domain}'s zone changed while editing it, try again ({e})") } else { e })?;
Ok(Handle::new().result(json!({ "domain": domain, "uri": written["uri"], "cid": written["cid"], "record": state["record"], "records": state["records"] })).done())
}
_ => Ok(Handle::new()),
}
}
fn list_records_handler(run: Run<Args>) -> Result<Handle, String> {
zone_handler(run, Action::List)
}
fn create_record_handler(run: Run<Args>) -> Result<Handle, String> {
zone_handler(run, Action::Create)
}
fn update_record_handler(run: Run<Args>) -> Result<Handle, String> {
zone_handler(run, Action::Update)
}
fn delete_record_handler(run: Run<Args>) -> Result<Handle, String> {
zone_handler(run, Action::Delete)
}
entries!(
list_domains => list_domains_handler,
list_records => list_records_handler,
create_record => create_record_handler,
update_record => update_record_handler,
delete_record => delete_record_handler
);
