dashboard: own links over the API, and CORS

GET /admin/dashboard/links/own and its event stream: a node's own links,
as LINKS_REPLY carried them, for other members' dashboards with a
token. CORS for the members' dashboard origins and --cors-origins,
without credentials.

Auth plan M3.

1 files changed, 19 insertions, 0 deletions

diff --git a/src/config/mod.rs b/src/config/mod.rs
index 60ad413..f0e5dc5 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -138,6 +138,13 @@ pub(crate) const OPTIONS: &[OptionSpec] = &[
         "How long after a login (POST /auth/login) its tokens may be refreshed; then the user logs in again.",
     ),
     option(
+        "cors-origins",
+        Kind::List,
+        "ORIGIN,[ORIGIN...]",
+        None,
+        "Origins (scheme://host[:port]) whose pages may read this node's own links and refresh tokens here, with a token (docs/access.md, Tokens): the dashboards of other members are allowed anyway, as the member list names them (dashboard-url). Without credentials: a page sends its token itself.",
+    ),
+    option(
         "bootstrap-users",
         Kind::List,
         "USER,[USER...]",
@@ -557,6 +564,8 @@ pub(crate) struct Settings {
     pub(crate) protocol_writers: Vec<String>,
     #[serde(default)]
     pub(crate) bootstrap_users: Vec<String>,
+    #[serde(default)]
+    pub(crate) cors_origins: Vec<String>,
     #[serde(
         default = "default_token_lifetime",
         with = "crate::units::duration_option"
@@ -790,6 +799,16 @@ impl Settings {
         if self.remake.is_some() && !self.genesis {
             bail!("remake makes a new swarm's document; it needs genesis");
         }
+        if let Some(bad) = self.cors_origins.iter().find(|origin| {
+            url::Url::parse(origin)
+                .ok()
+                .filter(|url| url.origin().is_tuple())
+                .is_none_or(|url| url.origin().ascii_serialization() != **origin)
+        }) {
+            bail!(
+                "cors-origins: {bad:?} isn't an origin (scheme://host[:port], no path; * isn't taken)"
+            );
+        }
         if !self.bootstrap_users.is_empty() && !self.genesis {
             bail!(
                 "bootstrap-users names the first users of a new swarm; it needs genesis (drop it once the swarm exists)"