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| 1 | +import type { IncomingMessage, ServerResponse } from 'node:http'; |
| 2 | +import type { RuntimeContext } from '../types.js'; |
| 3 | +import { getGlobalLogger } from '../../logger.js'; |
| 4 | + |
| 5 | +const logger = getGlobalLogger(); |
| 6 | +const DID_PATTERN = /^did:claw:z[A-Za-z0-9]{32,}$/; |
| 7 | +const MAX_BODY_SIZE = 1_048_576; // 1 MB |
| 8 | + |
| 9 | +// ── Simple in-memory rate limiter ──────────────────────── |
| 10 | + |
| 11 | +interface RateBucket { |
| 12 | + count: number; |
| 13 | + resetAt: number; |
| 14 | +} |
| 15 | + |
| 16 | +const rateBuckets = new Map<string, RateBucket>(); |
| 17 | + |
| 18 | +function checkRateLimit(sourceIp: string, maxPerMinute: number): boolean { |
| 19 | + const now = Date.now(); |
| 20 | + const bucket = rateBuckets.get(sourceIp); |
| 21 | + if (!bucket || now >= bucket.resetAt) { |
| 22 | + rateBuckets.set(sourceIp, { count: 1, resetAt: now + 60_000 }); |
| 23 | + return true; |
| 24 | + } |
| 25 | + bucket.count++; |
| 26 | + return bucket.count <= maxPerMinute; |
| 27 | +} |
| 28 | + |
| 29 | +// ── Body reading ───────────────────────────────────────── |
| 30 | + |
| 31 | +function readBody(req: IncomingMessage, maxBytes: number): Promise<string> { |
| 32 | + return new Promise((resolve, reject) => { |
| 33 | + const chunks: Buffer[] = []; |
| 34 | + let totalSize = 0; |
| 35 | + req.on('data', (chunk: Buffer) => { |
| 36 | + totalSize += chunk.length; |
| 37 | + if (totalSize > maxBytes) { |
| 38 | + req.destroy(); |
| 39 | + reject(new Error('Body too large')); |
| 40 | + return; |
| 41 | + } |
| 42 | + chunks.push(chunk); |
| 43 | + }); |
| 44 | + req.on('end', () => resolve(Buffer.concat(chunks).toString('utf-8'))); |
| 45 | + req.on('error', reject); |
| 46 | + }); |
| 47 | +} |
| 48 | + |
| 49 | +// ── JSON response helper ───────────────────────────────── |
| 50 | + |
| 51 | +function writeJson(res: ServerResponse, status: number, data: unknown): void { |
| 52 | + res.setHeader('Content-Type', 'application/json'); |
| 53 | + res.writeHead(status); |
| 54 | + res.end(JSON.stringify(data)); |
| 55 | +} |
| 56 | + |
| 57 | +/** |
| 58 | + * Handle /relay/* requests. Returns true if the request was handled. |
| 59 | + * |
| 60 | + * Routes: |
| 61 | + * GET /relay/info — gateway info |
| 62 | + * GET /relay/:targetDid/ping — DID reachability check |
| 63 | + * ALL /relay/:targetDid/api/v1/... — proxy API requests to target |
| 64 | + */ |
| 65 | +export async function handleRelayRequest( |
| 66 | + req: IncomingMessage, |
| 67 | + res: ServerResponse, |
| 68 | + pathname: string, |
| 69 | + ctx: RuntimeContext, |
| 70 | +): Promise<boolean> { |
| 71 | + if (!pathname.startsWith('/relay/') && pathname !== '/relay') return false; |
| 72 | + if (!ctx.apiProxyService) return false; |
| 73 | + |
| 74 | + // Strip /relay prefix |
| 75 | + const subPath = pathname.slice('/relay'.length) || '/'; |
| 76 | + |
| 77 | + // GET /relay/info |
| 78 | + if (subPath === '/info' || subPath === '/info/') { |
| 79 | + if (req.method !== 'GET') { |
| 80 | + writeJson(res, 405, { error: 'Method not allowed' }); |
| 81 | + return true; |
| 82 | + } |
| 83 | + const selfDid = ctx.identityService.getSelfDid(); |
| 84 | + writeJson(res, 200, { |
| 85 | + data: { |
| 86 | + gatewayDid: selfDid, |
| 87 | + gatewayEnabled: true, |
| 88 | + }, |
| 89 | + }); |
| 90 | + return true; |
| 91 | + } |
| 92 | + |
| 93 | + // Parse /:targetDid/... |
| 94 | + // subPath starts with '/', e.g. '/did:claw:zXXX/ping' |
| 95 | + const withoutLeadingSlash = subPath.slice(1); |
| 96 | + const firstSlash = withoutLeadingSlash.indexOf('/'); |
| 97 | + const targetDid = firstSlash === -1 |
| 98 | + ? withoutLeadingSlash |
| 99 | + : withoutLeadingSlash.slice(0, firstSlash); |
| 100 | + const remaining = firstSlash === -1 ? '' : withoutLeadingSlash.slice(firstSlash); |
| 101 | + |
| 102 | + if (!DID_PATTERN.test(decodeURIComponent(targetDid))) { |
| 103 | + writeJson(res, 400, { error: 'Invalid DID format. Expected did:claw:z...' }); |
| 104 | + return true; |
| 105 | + } |
| 106 | + |
| 107 | + const decodedDid = decodeURIComponent(targetDid); |
| 108 | + |
| 109 | + // Rate limiting |
| 110 | + const sourceIp = (req.headers['x-forwarded-for'] as string)?.split(',')[0]?.trim() |
| 111 | + || req.socket.remoteAddress |
| 112 | + || 'unknown'; |
| 113 | + if (!checkRateLimit(sourceIp, ctx.apiProxyService.config.rateLimitPerMinute)) { |
| 114 | + res.setHeader('Retry-After', '60'); |
| 115 | + writeJson(res, 429, { error: 'Rate limit exceeded' }); |
| 116 | + return true; |
| 117 | + } |
| 118 | + |
| 119 | + // GET /:targetDid/ping |
| 120 | + if (remaining === '/ping' || remaining === '/ping/') { |
| 121 | + if (req.method !== 'GET') { |
| 122 | + writeJson(res, 405, { error: 'Method not allowed' }); |
| 123 | + return true; |
| 124 | + } |
| 125 | + try { |
| 126 | + const result = await ctx.apiProxyService.ping(decodedDid); |
| 127 | + writeJson(res, 200, { data: result }); |
| 128 | + } catch (err) { |
| 129 | + logger.error('[relay] Ping failed for %s: %s', decodedDid, (err as Error).message); |
| 130 | + writeJson(res, 502, { error: 'Ping failed' }); |
| 131 | + } |
| 132 | + return true; |
| 133 | + } |
| 134 | + |
| 135 | + // Proxy: /:targetDid/api/v1/... |
| 136 | + if (!remaining.startsWith('/api/')) { |
| 137 | + writeJson(res, 400, { error: 'Proxy path must start with /api/' }); |
| 138 | + return true; |
| 139 | + } |
| 140 | + |
| 141 | + // Read request body |
| 142 | + let body: string | undefined; |
| 143 | + if (req.method !== 'GET' && req.method !== 'HEAD' && req.method !== 'DELETE') { |
| 144 | + try { |
| 145 | + body = await readBody(req, MAX_BODY_SIZE); |
| 146 | + } catch { |
| 147 | + writeJson(res, 413, { error: 'Request body too large (max 1MB)' }); |
| 148 | + return true; |
| 149 | + } |
| 150 | + } |
| 151 | + |
| 152 | + // Collect headers to forward |
| 153 | + const forwardHeaders: Record<string, string> = {}; |
| 154 | + if (req.headers.authorization) { |
| 155 | + forwardHeaders['authorization'] = req.headers.authorization as string; |
| 156 | + } |
| 157 | + if (req.headers['content-type']) { |
| 158 | + forwardHeaders['content-type'] = req.headers['content-type'] as string; |
| 159 | + } |
| 160 | + forwardHeaders['accept'] = (req.headers.accept as string) || 'application/json'; |
| 161 | + |
| 162 | + try { |
| 163 | + const proxyResponse = await ctx.apiProxyService.proxyRequest( |
| 164 | + decodedDid, |
| 165 | + req.method || 'GET', |
| 166 | + remaining, |
| 167 | + forwardHeaders, |
| 168 | + body, |
| 169 | + ); |
| 170 | + |
| 171 | + // Write proxy response back to client |
| 172 | + for (const [key, value] of Object.entries(proxyResponse.headers)) { |
| 173 | + if (key.toLowerCase() === 'transfer-encoding') continue; |
| 174 | + res.setHeader(key, String(value)); |
| 175 | + } |
| 176 | + res.writeHead(proxyResponse.status); |
| 177 | + res.end(proxyResponse.body ?? ''); |
| 178 | + } catch (err) { |
| 179 | + writeJson(res, 504, { |
| 180 | + error: 'Gateway timeout — target node did not respond', |
| 181 | + detail: (err as Error).message, |
| 182 | + }); |
| 183 | + } |
| 184 | + |
| 185 | + return true; |
| 186 | +} |
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