feat(api): ✨ Add x-forwarded-for and x-forwarded-proto support

Author: CPlusPatch

CHANGELOG.md

@@ -6,6 +6,7 @@
 
 -  [x] 🥺 Emoji Reactions are now available! You can react to any note with custom emojis.
 -  [x] 🔎 Added support for [batch account data API](https://docs.joinmastodon.org/methods/accounts/#index).
+-  [x] 🛡️ Added support for `X-Forwarded-For` and `X-Forwarded-Proto` headers from trusted proxies.
 
 ### Backend
 

config/config.example.toml

@@ -65,6 +65,11 @@ base_url = "https://example.com"
 bind = "0.0.0.0"
 bind_port = 8080
 
+# IPs of trusted proxies (for X-Forwarded-For and X-Forwarded-Proto headers)
+# v4, v6, ranges and wildcards are supported
+# Your proxy must set these headers correctly for versia-server to work
+proxy_ips = []
+
 # Bans IPv4 or IPv6 IPs (wildcards, networks and ranges are supported)
 banned_ips = []
 # Banned user agents, regex format

packages/config/index.ts

@@ -384,6 +384,7 @@ export const ConfigSchema = z
             ),
             bind: z.string().min(1).default("0.0.0.0"),
             bind_port: unixPort.default(8080),
+            proxy_ips: z.array(ip).default([]),
             banned_ips: z.array(ip).default([]),
             banned_user_agents: z.array(regex).default([]),
             proxy_address: url

utils/server.ts

@@ -2,6 +2,7 @@ import type { ConfigSchema } from "@versia-server/config";
 import { debugResponse } from "@versia-server/kit/api";
 import { type Server, serve } from "bun";
 import type { Hono } from "hono";
+import { matches } from "ip-matching";
 import type { z } from "zod";
 import type { HonoEnv } from "~/types/api.ts";
 
@@ -22,7 +23,34 @@ export const createServer = (
             : undefined,
         hostname: config.http.bind,
         async fetch(req, server): Promise<Response> {
-            const output = await app.fetch(req, { ip: server.requestIP(req) });
+            const ip = server.requestIP(req);
+            const isTrustedProxy =
+                config.http.proxy_ips.includes("*") ||
+                (ip &&
+                    config.http.proxy_ips.some((proxyIp) =>
+                        matches(ip.address, proxyIp),
+                    ));
+
+            const url = new URL(req.url);
+
+            if (ip && isTrustedProxy) {
+                const xff = req.headers.get("x-forwarded-for");
+                const xfp = req.headers.get("x-forwarded-proto");
+
+                if (xff) {
+                    const forwardedIps = xff.split(",").map((s) => s.trim());
+                    const originalIp = forwardedIps[0];
+
+                    ip.address = originalIp;
+                    ip.family = originalIp.includes(":") ? "IPv6" : "IPv4";
+                }
+
+                if (xfp) {
+                    url.protocol = xfp;
+                }
+            }
+
+            const output = await app.fetch(req, { ip });
 
             await debugResponse(output.clone());