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fraiseql_server/middleware/rate_limit/
config.rs

1//! Rate limit configuration types.
2
3use serde::{Deserialize, Serialize};
4
5/// Default failed-login attempt cap, mirroring the CLI `toml_schema` default so the
6/// runtime can tell an operator-tuned value from an untouched one (#356).
7pub const DEFAULT_FAILED_LOGIN_MAX_ATTEMPTS: u32 = 10;
8/// Default failed-login lockout window in seconds, mirroring the CLI default (#356).
9pub const DEFAULT_FAILED_LOGIN_LOCKOUT_SECS: u64 = 900;
10
11const fn default_failed_login_max_attempts() -> u32 {
12    DEFAULT_FAILED_LOGIN_MAX_ATTEMPTS
13}
14const fn default_failed_login_lockout_secs() -> u64 {
15    DEFAULT_FAILED_LOGIN_LOCKOUT_SECS
16}
17
18/// Minimal mirror of the `[security.rate_limiting]` TOML section, deserialized
19/// from the compiled schema's `security.rate_limiting` JSON key.
20#[derive(Debug, Clone, Deserialize, Default)]
21#[serde(default)]
22pub struct RateLimitingSecurityConfig {
23    /// Enable rate limiting.
24    pub enabled: bool,
25    /// Global request rate cap (requests per second, per IP).
26    pub requests_per_second: u32,
27    /// Burst allowance above the steady-state rate.
28    pub burst_size: u32,
29    /// Auth initiation endpoint — max requests per window.
30    pub auth_start_max_requests: u32,
31    /// Auth initiation window in seconds.
32    pub auth_start_window_secs: u64,
33    /// OAuth callback endpoint — max requests per window.
34    pub auth_callback_max_requests: u32,
35    /// OAuth callback window in seconds.
36    pub auth_callback_window_secs: u64,
37    /// Token refresh endpoint — max requests per window.
38    pub auth_refresh_max_requests: u32,
39    /// Token refresh window in seconds.
40    pub auth_refresh_window_secs: u64,
41    /// Maximum failed first-factor login attempts before lockout.
42    ///
43    /// Mirrors the CLI `[security.rate_limiting] failed_login_max_attempts` field.
44    /// The off-the-shelf binary performs no first-factor login of its own (OIDC/JWT
45    /// is validated cryptographically and first-factor auth is delegated to the
46    /// provider; TOTP MFA is a library-only feature), so it cannot enforce this. A
47    /// value tuned away from the default is rejected at startup in production (#356);
48    /// see `failed_login_lockout_check`.
49    #[serde(default = "default_failed_login_max_attempts")]
50    pub failed_login_max_attempts: u32,
51    /// Lockout window in seconds after `failed_login_max_attempts` is exceeded.
52    /// Not enforced by the binary — see `failed_login_max_attempts`.
53    #[serde(default = "default_failed_login_lockout_secs")]
54    pub failed_login_lockout_secs: u64,
55    /// Per-authenticated-user request rate in requests/second.
56    /// Defaults to 10× `requests_per_second` if not set.
57    #[serde(default)]
58    pub requests_per_second_per_user: Option<u32>,
59    /// Redis URL for distributed rate limiting (not yet implemented).
60    pub redis_url: Option<String>,
61    /// Trust `X-Real-IP` / `X-Forwarded-For` headers for the client IP.
62    ///
63    /// Enable only when FraiseQL is deployed behind a trusted reverse proxy
64    /// (e.g. nginx, Cloudflare, AWS ALB) that sets these headers.  Enabling
65    /// without a trusted proxy allows clients to spoof their IP address.
66    #[serde(default)]
67    pub trust_proxy_headers: bool,
68
69    /// CIDR ranges trusted as proxy IPs (e.g. `["10.0.0.0/8", "172.16.0.0/12"]`).
70    ///
71    /// When set and `trust_proxy_headers = true`, X-Forwarded-For is only honoured
72    /// when the direct connection IP falls within one of these CIDR ranges.
73    /// Requests arriving from outside these ranges use the connection IP directly,
74    /// preventing clients from spoofing their address by setting X-Forwarded-For.
75    ///
76    /// When `None` and `trust_proxy_headers = true`, all proxy IPs are trusted
77    /// (less secure — a startup warning is emitted).
78    #[serde(default)]
79    pub trusted_proxy_cidrs: Option<Vec<String>>,
80}
81
82/// Rate limiting configuration (token-bucket algorithm).
83///
84/// Enforces request-per-second limits per IP/user across all GraphQL
85/// operations. This is the canonical rate limiter for request throttling.
86///
87/// Distinct from `fraiseql_auth::AuthRateLimitConfig`, which uses a
88/// sliding-window algorithm for auth endpoint brute-force protection.
89#[derive(Debug, Clone, Serialize, Deserialize)]
90pub struct RateLimitConfig {
91    /// Enable rate limiting
92    pub enabled: bool,
93
94    /// Requests per second per IP
95    pub rps_per_ip: u32,
96
97    /// Requests per second per user (if authenticated)
98    pub rps_per_user: u32,
99
100    /// Burst capacity (maximum tokens to accumulate)
101    pub burst_size: u32,
102
103    /// Cleanup interval in seconds (remove stale entries)
104    pub cleanup_interval_secs: u64,
105
106    /// Trust `X-Real-IP` / `X-Forwarded-For` headers for client IP extraction.
107    ///
108    /// Must only be enabled when behind a trusted reverse proxy.
109    pub trust_proxy_headers: bool,
110
111    /// Parsed CIDR ranges trusted as proxy IPs.
112    ///
113    /// When non-empty, X-Forwarded-For is only trusted if the direct connection IP
114    /// falls within one of these ranges.  An empty `Vec` with `trust_proxy_headers = true`
115    /// means all direct IPs are treated as trusted proxies (less secure).
116    pub trusted_proxy_cidrs: Vec<ipnet::IpNet>,
117
118    /// Maximum number of unique IP/user buckets to hold in memory at once.
119    ///
120    /// When any of the three tracking maps (`ip_buckets`, `user_buckets`,
121    /// `path_ip_buckets`) reaches this limit, requests arriving from a
122    /// previously-unseen key are **denied** until stale entries are evicted by
123    /// the background cleanup task.  This prevents unbounded memory growth
124    /// under a flood of spoofed or unique source IPs.
125    ///
126    /// Defaults to `100_000`.  At ~200 bytes per bucket, this cap allows up to
127    /// ~20 `MiB` of tracking state per map before enforcement kicks in.
128    #[serde(default = "default_max_buckets")]
129    pub max_buckets: usize,
130}
131
132const fn default_max_buckets() -> usize {
133    100_000
134}
135
136impl Default for RateLimitConfig {
137    fn default() -> Self {
138        Self {
139            enabled:               true,
140            rps_per_ip:            100,  // 100 req/sec per IP
141            rps_per_user:          1000, // 1000 req/sec per user
142            burst_size:            500,  // Allow bursts up to 500 requests
143            cleanup_interval_secs: 300,  // Clean up every 5 minutes
144            trust_proxy_headers:   false,
145            trusted_proxy_cidrs:   Vec::new(),
146            max_buckets:           100_000,
147        }
148    }
149}
150
151impl RateLimitConfig {
152    /// Build from the `[security.rate_limiting]` config embedded in the compiled schema.
153    ///
154    /// Maps `requests_per_second` → `rps_per_ip` and `burst_size` directly.
155    /// `rps_per_user` uses the explicit `requests_per_second_per_user` value when set,
156    /// or defaults to 10× `requests_per_second`.
157    ///
158    /// The default 10× multiplier reflects that authenticated users are identifiable
159    /// (abuse is traceable) and include service accounts with higher call rates.
160    /// Operators can override with `requests_per_second_per_user` in `fraiseql.toml`.
161    #[must_use]
162    pub fn from_security_config(sec: &RateLimitingSecurityConfig) -> Self {
163        let trusted_proxy_cidrs = sec
164            .trusted_proxy_cidrs
165            .as_deref()
166            .unwrap_or(&[])
167            .iter()
168            .filter_map(|s| {
169                s.parse::<ipnet::IpNet>()
170                    .map_err(|e| {
171                        tracing::warn!(cidr = %s, error = %e, "Invalid trusted_proxy_cidr — skipping");
172                    })
173                    .ok()
174            })
175            .collect();
176
177        Self {
178            enabled: sec.enabled,
179            rps_per_ip: sec.requests_per_second,
180            rps_per_user: sec
181                .requests_per_second_per_user
182                .unwrap_or_else(|| sec.requests_per_second.saturating_mul(10)),
183            burst_size: sec.burst_size,
184            cleanup_interval_secs: 300,
185            trust_proxy_headers: sec.trust_proxy_headers,
186            trusted_proxy_cidrs,
187            max_buckets: default_max_buckets(),
188        }
189    }
190}
191
192/// Result returned by all `check_*` rate-limit methods.
193///
194/// Carries the allow/deny decision, the approximate remaining token count
195/// (used for the `X-RateLimit-Remaining` response header), and the
196/// recommended `Retry-After` interval in seconds (0 when the request was
197/// allowed).
198#[derive(Debug, Clone)]
199pub struct CheckResult {
200    /// Whether the request should be allowed.
201    pub allowed:          bool,
202    /// Tokens remaining in the bucket after this request (≥ 0).
203    pub remaining:        f64,
204    /// Seconds the client should wait before retrying (0 when allowed).
205    pub retry_after_secs: u32,
206}
207
208impl CheckResult {
209    pub(super) const fn allow(remaining: f64) -> Self {
210        Self {
211            allowed: true,
212            remaining,
213            retry_after_secs: 0,
214        }
215    }
216
217    pub(super) const fn deny(retry_after_secs: u32) -> Self {
218        Self {
219            allowed: false,
220            remaining: 0.0,
221            retry_after_secs,
222        }
223    }
224}