policy

server/src/services/videoAuthService/streamParsing.js

@@ -0,0 +1,90 @@
+// Video Auth Stream Parsing
+// Purpose: Parses MediaMTX path/body payloads into normalized stream targets for rover and room media checks.
+// Scope: Handles WHEP/WHP path-prefix trimming and SRT streamid extraction without performing auth decisions.
+const { loadConfig } = require('../../helpers/configLoader');
+
+const config = loadConfig();
+const mediaConfig = config.media || {};
+
+function getPathPrefix() {
+  const base = mediaConfig.whepBaseUrl;
+  if (!base) return '';
+  try {
+    const parsed = new URL(base);
+    return parsed.pathname || '';
+  } catch {
+    return base.replace(/^[^/]*:\/\//, '').replace(/^[^/]+/, '');
+  }
+}
+
+const whepPathPrefix = getPathPrefix().replace(/\/+$/, '').replace(/^\/+/, '');
+const whepPrefixSegments = whepPathPrefix ? whepPathPrefix.split('/').filter(Boolean) : [];
+
+function extractStreamInfo(path) {
+  const segments = (path || '').split('/').filter(Boolean);
+  if (!segments.length) return null;
+
+  let start = 0;
+  if (whepPrefixSegments.length && whepPrefixSegments.every((segment, idx) => segments[idx] === segment)) {
+    start = whepPrefixSegments.length;
+  }
+
+  let end = segments.length;
+  if (segments[end - 1] === 'whep' || segments[end - 1] === 'whip') {
+    end -= 1;
+  }
+
+  const remaining = segments.slice(start, end);
+  if (remaining.length === 1) {
+    const rawId = remaining[0] || '';
+    if (rawId.endsWith('-fwd')) {
+      return { type: 'rover', id: rawId, baseId: rawId.slice(0, -4) };
+    }
+    const baseId = rawId.endsWith('-audio') ? rawId.slice(0, -6) : rawId;
+    return { type: 'rover', id: rawId, baseId };
+  }
+
+  if (remaining.length === 2 && remaining[0] === 'room') {
+    return { type: 'room', id: remaining[1] || '' };
+  }
+
+  return null;
+}
+
+function extractSrtStreamId(rawValue) {
+  const value = decodeURIComponent(String(rawValue || '').trim());
+  if (!value) return '';
+
+  const match = value.match(/(?:^|[?&]|,|#!::)r=([^,&]+)/);
+  if (match?.[1]) {
+    return match[1];
+  }
+
+  if (!/[?&=,:]/.test(value)) {
+    return value;
+  }
+
+  return '';
+}
+
+function extractStreamInfoFromBody(body = {}) {
+  const fromPath = extractStreamInfo((body.path || '').replace(/^\//, ''));
+  if (fromPath) return fromPath;
+
+  const srtId =
+    extractSrtStreamId(body.streamid) ||
+    extractSrtStreamId(body.streamId) ||
+    extractSrtStreamId(body.query);
+  if (!srtId) return null;
+
+  if (srtId.endsWith('-fwd')) {
+    return { type: 'rover', id: srtId, baseId: srtId.slice(0, -4) };
+  }
+
+  const baseId = srtId.endsWith('-audio') ? srtId.slice(0, -6) : srtId;
+  return { type: 'rover', id: srtId, baseId };
+}
+
+module.exports = {
+  extractStreamInfoFromBody,
+};