From 8f38dc2e7f9dc7272c6882fff369be5e43dc711a Mon Sep 17 00:00:00 2001 From: tobi <31960611+tsmethurst@users.noreply.github.com> Date: Wed, 23 Aug 2023 14:32:27 +0200 Subject: [PATCH] [feature] Add rate limit exceptions option, use ISO8601 for rate limit reset (#2151) * start updating rate limiting, add exceptions * tests, comments, tidying up * add rate limiting exceptions to example config * envparsing * nolint * apply kimbediff * add examples --- cmd/gotosocial/action/server/server.go | 9 +- docs/api/ratelimiting.md | 6 +- docs/configuration/advanced.md | 28 +++ example/config.yaml | 28 +++ internal/config/config.go | 1 + internal/config/defaults.go | 3 +- internal/config/flags.go | 1 + internal/config/helpers.gen.go | 25 +++ ..._test.go => contentsecuritypolicy_test.go} | 0 internal/middleware/ratelimit.go | 131 ++++++++++-- internal/middleware/ratelimit_test.go | 192 ++++++++++++++++++ test/envparsing.sh | 5 + 12 files changed, 402 insertions(+), 27 deletions(-) rename internal/middleware/{middleware_test.go => contentsecuritypolicy_test.go} (100%) create mode 100644 internal/middleware/ratelimit_test.go diff --git a/cmd/gotosocial/action/server/server.go b/cmd/gotosocial/action/server/server.go index e966c46be..fc08c57ac 100644 --- a/cmd/gotosocial/action/server/server.go +++ b/cmd/gotosocial/action/server/server.go @@ -266,10 +266,11 @@ var Start action.GTSAction = func(ctx context.Context) error { // create required middleware // rate limiting - limit := config.GetAdvancedRateLimitRequests() - clLimit := middleware.RateLimit(limit) // client api - s2sLimit := middleware.RateLimit(limit) // server-to-server (AP) - fsLimit := middleware.RateLimit(limit) // fileserver / web templates + rlLimit := config.GetAdvancedRateLimitRequests() + rlExceptions := config.GetAdvancedRateLimitExceptions() + clLimit := middleware.RateLimit(rlLimit, rlExceptions) // client api + s2sLimit := middleware.RateLimit(rlLimit, rlExceptions) // server-to-server (AP) + fsLimit := middleware.RateLimit(rlLimit, rlExceptions) // fileserver / web templates // throttling cpuMultiplier := config.GetAdvancedThrottlingMultiplier() diff --git a/docs/api/ratelimiting.md b/docs/api/ratelimiting.md index 2bdcdf2ba..d99f4d379 100644 --- a/docs/api/ratelimiting.md +++ b/docs/api/ratelimiting.md @@ -16,7 +16,7 @@ Every response will include the current status of the rate limit with the follow - `X-Ratelimit-Limit`: maximum number of requests allowed per time period. - `X-Ratelimit-Remaining`: number of remaining requests that can still be performed within. -- `X-Ratelimit-Reset`: unix timestamp indicating when the rate limit will reset. +- `X-Ratelimit-Reset`: ISO8601 timestamp indicating when the rate limit will reset. In case the rate limit is exceeded, an [HTTP 429 Too Many Requests](https://developer.mozilla.org/en-US/docs/Web/HTTP/Status/429) error is returned to the caller. @@ -35,3 +35,7 @@ If you don't have an HTTP proxy, then it's likely caused by NAT. In this case yo ### Can I configure the rate limit? Can I just turn it off? Yes! Set `advanced-rate-limit-requests: 0` in the config. + +### Can I exclude one or more IP addresses from rate limiting, but leave the rest in place? + +Yes! Set `advanced-rate-limit-exceptions` in the config. diff --git a/docs/configuration/advanced.md b/docs/configuration/advanced.md index 530b75f0f..b0ff4c7b6 100644 --- a/docs/configuration/advanced.md +++ b/docs/configuration/advanced.md @@ -52,6 +52,34 @@ advanced-cookies-samesite: "lax" # Default: 300 advanced-rate-limit-requests: 300 +# Array of string. CIDRs to except from rate limit restrictions. +# Any IPs inside the CIDR range(s) will not have rate limiting +# applied on their requests, and rate limit headers will not be +# set for those requests. +# +# This can be useful in the following example cases (and probably +# a bunch of others as well): +# +# 1. You've set up an automated service that uses the API, and +# it keeps getting rate limited, even though you trust it's +# not abusing the instance. +# +# 2. You live with multiple people who use the same instance, +# and you're all using the same router/NAT, so you all have +# the same IP address, and you keep rate limiting each other. +# +# 3. You mostly use your own home internet to access your instance, +# and you want to exempt your home internet from rate limiting. +# +# You should be careful when adjusting this setting, since you +# might inadvertently make rate limiting useless if you set too +# wide a range. If in doubt, be too restrictive rather than too +# lenient, and adjust as you go. +# +# Example: ["192.168.0.0/16"] +# Default: [] +advanced-rate-limit-exceptions: [] + # Int. Amount of open requests to permit per CPU, per router grouping, before applying http # request throttling. Any requests beyond the calculated limit are held in a backlog queue for # up to 30 seconds before either being processed or timing out. Requests that don't fit in the backlog diff --git a/example/config.yaml b/example/config.yaml index bc8e3d7c1..c27a8f64b 100644 --- a/example/config.yaml +++ b/example/config.yaml @@ -848,6 +848,34 @@ advanced-cookies-samesite: "lax" # Default: 300 advanced-rate-limit-requests: 300 +# Array of string. CIDRs to except from rate limit restrictions. +# Any IPs inside the CIDR range(s) will not have rate limiting +# applied on their requests, and rate limit headers will not be +# set for those requests. +# +# This can be useful in the following example cases (and probably +# a bunch of others as well): +# +# 1. You've set up an automated service that uses the API, and +# it keeps getting rate limited, even though you trust it's +# not abusing the instance. +# +# 2. You live with multiple people who use the same instance, +# and you're all using the same router/NAT, so you all have +# the same IP address, and you keep rate limiting each other. +# +# 3. You mostly use your own home internet to access your instance, +# and you want to exempt your home internet from rate limiting. +# +# You should be careful when adjusting this setting, since you +# might inadvertently make rate limiting useless if you set too +# wide a range. If in doubt, be too restrictive rather than too +# lenient, and adjust as you go. +# +# Example: ["192.168.0.0/16"] +# Default: [] +advanced-rate-limit-exceptions: [] + # Int. Amount of open requests to permit per CPU, per router grouping, before applying http # request throttling. Any requests beyond the calculated limit are held in a backlog queue for # up to 30 seconds before either being processed or timing out. Requests that don't fit in the backlog diff --git a/internal/config/config.go b/internal/config/config.go index 86f6b00dd..612947c5e 100644 --- a/internal/config/config.go +++ b/internal/config/config.go @@ -148,6 +148,7 @@ type Configuration struct { AdvancedCookiesSamesite string `name:"advanced-cookies-samesite" usage:"'strict' or 'lax', see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie/SameSite"` AdvancedRateLimitRequests int `name:"advanced-rate-limit-requests" usage:"Amount of HTTP requests to permit within a 5 minute window. 0 or less turns rate limiting off."` + AdvancedRateLimitExceptions []string `name:"advanced-rate-limit-exceptions" usage:"Slice of CIDRs to exclude from rate limit restrictions."` AdvancedThrottlingMultiplier int `name:"advanced-throttling-multiplier" usage:"Multiplier to use per cpu for http request throttling. 0 or less turns throttling off."` AdvancedThrottlingRetryAfter time.Duration `name:"advanced-throttling-retry-after" usage:"Retry-After duration response to send for throttled requests."` AdvancedSenderMultiplier int `name:"advanced-sender-multiplier" usage:"Multiplier to use per cpu for batching outgoing fedi messages. 0 or less turns batching off (not recommended)."` diff --git a/internal/config/defaults.go b/internal/config/defaults.go index 3703d8372..9ad9c125c 100644 --- a/internal/config/defaults.go +++ b/internal/config/defaults.go @@ -122,7 +122,8 @@ var Defaults = Configuration{ AdvancedCookiesSamesite: "lax", AdvancedRateLimitRequests: 300, // 1 per second per 5 minutes - AdvancedThrottlingMultiplier: 8, // 8 open requests per CPU + AdvancedRateLimitExceptions: []string{}, + AdvancedThrottlingMultiplier: 8, // 8 open requests per CPU AdvancedThrottlingRetryAfter: time.Second * 30, AdvancedSenderMultiplier: 2, // 2 senders per CPU AdvancedCSPExtraURIs: []string{}, diff --git a/internal/config/flags.go b/internal/config/flags.go index 927f4ddfb..ad07ec2ef 100644 --- a/internal/config/flags.go +++ b/internal/config/flags.go @@ -149,6 +149,7 @@ func (s *ConfigState) AddServerFlags(cmd *cobra.Command) { // Advanced flags cmd.Flags().String(AdvancedCookiesSamesiteFlag(), cfg.AdvancedCookiesSamesite, fieldtag("AdvancedCookiesSamesite", "usage")) cmd.Flags().Int(AdvancedRateLimitRequestsFlag(), cfg.AdvancedRateLimitRequests, fieldtag("AdvancedRateLimitRequests", "usage")) + cmd.Flags().StringSlice(AdvancedRateLimitExceptionsFlag(), cfg.AdvancedRateLimitExceptions, fieldtag("AdvancedRateLimitExceptions", "usage")) cmd.Flags().Int(AdvancedThrottlingMultiplierFlag(), cfg.AdvancedThrottlingMultiplier, fieldtag("AdvancedThrottlingMultiplier", "usage")) cmd.Flags().Duration(AdvancedThrottlingRetryAfterFlag(), cfg.AdvancedThrottlingRetryAfter, fieldtag("AdvancedThrottlingRetryAfter", "usage")) cmd.Flags().Int(AdvancedSenderMultiplierFlag(), cfg.AdvancedSenderMultiplier, fieldtag("AdvancedSenderMultiplier", "usage")) diff --git a/internal/config/helpers.gen.go b/internal/config/helpers.gen.go index ab7d38a8a..801d4f667 100644 --- a/internal/config/helpers.gen.go +++ b/internal/config/helpers.gen.go @@ -2274,6 +2274,31 @@ func GetAdvancedRateLimitRequests() int { return global.GetAdvancedRateLimitRequ // SetAdvancedRateLimitRequests safely sets the value for global configuration 'AdvancedRateLimitRequests' field func SetAdvancedRateLimitRequests(v int) { global.SetAdvancedRateLimitRequests(v) } +// GetAdvancedRateLimitExceptions safely fetches the Configuration value for state's 'AdvancedRateLimitExceptions' field +func (st *ConfigState) GetAdvancedRateLimitExceptions() (v []string) { + st.mutex.RLock() + v = st.config.AdvancedRateLimitExceptions + st.mutex.RUnlock() + return +} + +// SetAdvancedRateLimitExceptions safely sets the Configuration value for state's 'AdvancedRateLimitExceptions' field +func (st *ConfigState) SetAdvancedRateLimitExceptions(v []string) { + st.mutex.Lock() + defer st.mutex.Unlock() + st.config.AdvancedRateLimitExceptions = v + st.reloadToViper() +} + +// AdvancedRateLimitExceptionsFlag returns the flag name for the 'AdvancedRateLimitExceptions' field +func AdvancedRateLimitExceptionsFlag() string { return "advanced-rate-limit-exceptions" } + +// GetAdvancedRateLimitExceptions safely fetches the value for global configuration 'AdvancedRateLimitExceptions' field +func GetAdvancedRateLimitExceptions() []string { return global.GetAdvancedRateLimitExceptions() } + +// SetAdvancedRateLimitExceptions safely sets the value for global configuration 'AdvancedRateLimitExceptions' field +func SetAdvancedRateLimitExceptions(v []string) { global.SetAdvancedRateLimitExceptions(v) } + // GetAdvancedThrottlingMultiplier safely fetches the Configuration value for state's 'AdvancedThrottlingMultiplier' field func (st *ConfigState) GetAdvancedThrottlingMultiplier() (v int) { st.mutex.RLock() diff --git a/internal/middleware/middleware_test.go b/internal/middleware/contentsecuritypolicy_test.go similarity index 100% rename from internal/middleware/middleware_test.go rename to internal/middleware/contentsecuritypolicy_test.go diff --git a/internal/middleware/ratelimit.go b/internal/middleware/ratelimit.go index ae31fca56..a59a3e608 100644 --- a/internal/middleware/ratelimit.go +++ b/internal/middleware/ratelimit.go @@ -20,47 +20,136 @@ package middleware import ( "net" "net/http" + "net/netip" + "strconv" "time" "github.com/gin-gonic/gin" + "github.com/superseriousbusiness/gotosocial/internal/gtserror" + "github.com/superseriousbusiness/gotosocial/internal/util" "github.com/ulule/limiter/v3" - limitergin "github.com/ulule/limiter/v3/drivers/middleware/gin" "github.com/ulule/limiter/v3/drivers/store/memory" ) const rateLimitPeriod = 5 * time.Minute -// RateLimit returns a gin middleware that will automatically rate limit caller (by IP address), -// and enrich the response header with the following headers: +// RateLimit returns a gin middleware that will automatically rate +// limit caller (by IP address), and enrich the response header with +// the following headers: // -// - `x-ratelimit-limit` - maximum number of requests allowed per time period (fixed). -// - `x-ratelimit-remaining` - number of remaining requests that can still be performed. -// - `x-ratelimit-reset` - unix timestamp when the rate limit will reset. +// - `X-Ratelimit-Limit` - max requests allowed per time period (fixed). +// - `X-Ratelimit-Remaining` - requests remaining for this IP before reset. +// - `X-Ratelimit-Reset` - ISO8601 timestamp when the rate limit will reset. // -// If `x-ratelimit-limit` is exceeded, the request is aborted and an HTTP 429 TooManyRequests -// status is returned. +// If `X-Ratelimit-Limit` is exceeded, the request is aborted and an +// HTTP 429 TooManyRequests status is returned. // -// If the config AdvancedRateLimitRequests value is <= 0, then a noop handler will be returned, -// which performs no rate limiting. -func RateLimit(limit int) gin.HandlerFunc { +// If the config AdvancedRateLimitRequests value is <= 0, then a noop +// handler will be returned, which performs no rate limiting. +func RateLimit(limit int, exceptions []string) gin.HandlerFunc { if limit <= 0 { - // use noop middleware if ratelimiting is disabled + // Rate limiting is disabled. + // Return noop middleware. return func(ctx *gin.Context) {} } limiter := limiter.New( memory.NewStore(), - limiter.Rate{Period: rateLimitPeriod, Limit: int64(limit)}, - limiter.WithIPv6Mask(net.CIDRMask(64, 128)), // apply /64 mask to IPv6 addresses + limiter.Rate{ + Period: rateLimitPeriod, + Limit: int64(limit), + }, ) - // use custom rate limit reached error - handler := func(c *gin.Context) { - c.AbortWithStatusJSON(http.StatusTooManyRequests, gin.H{"error": "rate limit reached"}) + // Convert exceptions IP ranges into prefixes. + exceptPrefs := make([]netip.Prefix, len(exceptions)) + for i, str := range exceptions { + exceptPrefs[i] = netip.MustParsePrefix(str) } - return limitergin.NewMiddleware( - limiter, - limitergin.WithLimitReachedHandler(handler), - ) + // It's prettymuch impossible to effectively + // rate limit the immense IPv6 address space + // unless we mask some of the bytes. + // + // This mask is pretty coarse, and puts IPv6 + // blocking on more or less the same footing + // as IPv4 blocking in terms of how likely it + // is to prevent abuse while still allowing + // legit users access to the service. + ipv6Mask := net.CIDRMask(64, 128) + + return func(c *gin.Context) { + // Use Gin's heuristic for determining + // clientIP, which accounts for reverse + // proxies and trusted proxies setting. + clientIP := netip.MustParseAddr(c.ClientIP()) + + // Check if this IP is exempt from rate + // limits and skip further checks if so. + for _, prefix := range exceptPrefs { + if prefix.Contains(clientIP) { + c.Next() + return + } + } + + if clientIP.Is6() { + // Convert to "net" package IP for mask. + asIP := net.IP(clientIP.AsSlice()) + + // Apply coarse IPv6 mask. + asIP = asIP.Mask(ipv6Mask) + + // Convert back to netip.Addr from net.IP. + clientIP, _ = netip.AddrFromSlice(asIP) + } + + // Fetch rate limit info for this (masked) clientIP. + context, err := limiter.Get(c, clientIP.String()) + if err != nil { + // Since we use an in-memory cache now, + // it's actually impossible for this to + // error, but handle it nicely anyway in + // case we switch implementation in future. + errWithCode := gtserror.NewErrorInternalError(err) + + // Set error on gin context so it'll + // be picked up by logging middleware. + c.Error(errWithCode) //nolint:errcheck + + // Bail with 500. + c.AbortWithStatusJSON( + errWithCode.Code(), + gin.H{"error": errWithCode.Safe()}, + ) + return + } + + // Provide reset in same format used by + // Mastodon. There's no real standard as + // to what format X-RateLimit-Reset SHOULD + // use, but since most clients interacting + // with us will expect the Mastodon version, + // it makes sense to take this. + resetT := time.Unix(context.Reset, 0) + reset := util.FormatISO8601(resetT) + + c.Header("X-RateLimit-Limit", strconv.FormatInt(context.Limit, 10)) + c.Header("X-RateLimit-Remaining", strconv.FormatInt(context.Remaining, 10)) + c.Header("X-RateLimit-Reset", reset) + + if context.Reached { + // Return JSON error message for + // consistency with other endpoints. + c.AbortWithStatusJSON( + http.StatusTooManyRequests, + gin.H{"error": "rate limit reached"}, + ) + return + } + + // Allow the request + // to continue. + c.Next() + } } diff --git a/internal/middleware/ratelimit_test.go b/internal/middleware/ratelimit_test.go new file mode 100644 index 000000000..ad9891d79 --- /dev/null +++ b/internal/middleware/ratelimit_test.go @@ -0,0 +1,192 @@ +// GoToSocial +// Copyright (C) GoToSocial Authors admin@gotosocial.org +// SPDX-License-Identifier: AGPL-3.0-or-later +// +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU Affero General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. +// +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU Affero General Public License for more details. +// +// You should have received a copy of the GNU Affero General Public License +// along with this program. If not, see . + +package middleware_test + +import ( + "net/http" + "net/http/httptest" + "strconv" + "testing" + "time" + + "github.com/gin-gonic/gin" + "github.com/stretchr/testify/suite" + "github.com/superseriousbusiness/gotosocial/internal/middleware" + "github.com/superseriousbusiness/gotosocial/internal/util" +) + +type RateLimitTestSuite struct { + suite.Suite +} + +func (suite *RateLimitTestSuite) TestRateLimit() { + // Suppress warnings about debug mode. + gin.SetMode(gin.ReleaseMode) + + const ( + trustedPlatform = "X-Test-IP" + rlLimit = "X-RateLimit-Limit" + rlRemaining = "X-RateLimit-Remaining" + rlReset = "X-RateLimit-Reset" + ) + + type rlTest struct { + limit int + exceptions []string + clientIP string + shouldPanic bool + shouldExcept bool + } + + for _, test := range []rlTest{ + { + limit: 10, + exceptions: []string{}, + clientIP: "192.0.2.0", + shouldPanic: false, + shouldExcept: false, + }, + { + limit: 10, + exceptions: []string{}, + clientIP: "192.0.2.0", + shouldPanic: false, + shouldExcept: false, + }, + { + limit: 10, + exceptions: []string{"192.0.2.0/24"}, + clientIP: "192.0.2.0", + shouldPanic: false, + shouldExcept: true, + }, + { + limit: 10, + exceptions: []string{"192.0.2.0/32"}, + clientIP: "192.0.2.1", + shouldPanic: false, + shouldExcept: false, + }, + { + limit: 10, + exceptions: []string{"Ceci n'est pas une CIDR"}, + clientIP: "192.0.2.0", + shouldPanic: true, + shouldExcept: false, + }, + } { + if test.shouldPanic { + // Try to trigger panic. + suite.Panics(func() { + _ = middleware.RateLimit( + test.limit, + test.exceptions, + ) + }) + continue + } + + rlMiddleware := middleware.RateLimit( + test.limit, + test.exceptions, + ) + + // Approximate time when this limiter will reset. + resetAt := time.Now().Add(5 * time.Minute) + + // Make requests up to + + // just over the limit. + limitedAt := test.limit + 1 + for requestsCount := 1; requestsCount < limitedAt; requestsCount++ { + var ( + recorder = httptest.NewRecorder() + ctx, e = gin.CreateTestContext(recorder) + ) + + // Instruct engine to derive + // clientIP from test header. + e.TrustedPlatform = trustedPlatform + ctx.Request = httptest.NewRequest(http.MethodGet, "/example", nil) + ctx.Request.Header.Add(trustedPlatform, test.clientIP) + + // Call the rate limiter. + rlMiddleware(ctx) + + // Fetch RL headers if present. + var ( + limitStr = recorder.Header().Get(rlLimit) + remainingStr = recorder.Header().Get(rlRemaining) + resetStr = recorder.Header().Get(rlReset) + ) + + if test.shouldExcept { + // Request should be allowed through, + // no rate-limit headers should be written. + suite.Equal(http.StatusOK, recorder.Code) + suite.Empty(limitStr) + suite.Empty(remainingStr) + suite.Empty(resetStr) + continue + } + + suite.Equal(strconv.Itoa(test.limit), limitStr) + suite.Equal(strconv.Itoa(test.limit-requestsCount), remainingStr) + + // Ensure reset is ISO8601, and resets at + // approximate reset time (+/- 10 seconds). + reset, err := util.ParseISO8601(resetStr) + if err != nil { + suite.FailNow("", "couldn't parse %s as ISO8601: %q", resetStr, err.Error()) + } + suite.WithinDuration(resetAt, reset, 10*time.Second) + + if requestsCount < limitedAt { + // Request should be allowed through. + suite.Equal(http.StatusOK, recorder.Code) + continue + } + + // Request should be denied. + suite.Equal(http.StatusTooManyRequests, recorder.Code) + + // Make a final request with an unrelated IP to + // ensure it's only the one IP being limited. + var ( + unrelatedRecorder = httptest.NewRecorder() + unrelatedCtx, unrelatedE = gin.CreateTestContext(unrelatedRecorder) + ) + + // Instruct engine to derive + // clientIP from test header. + unrelatedE.TrustedPlatform = trustedPlatform + unrelatedCtx.Request = httptest.NewRequest(http.MethodGet, "/example", nil) + unrelatedCtx.Request.Header.Add(trustedPlatform, "192.0.2.255") + + // Call the rate limiter. + rlMiddleware(unrelatedCtx) + + // Request should be allowed through. + suite.Equal(http.StatusOK, unrelatedRecorder.Code) + + } + } +} + +func TestRateLimitTestSuite(t *testing.T) { + suite.Run(t, new(RateLimitTestSuite)) +} diff --git a/test/envparsing.sh b/test/envparsing.sh index 2ab17dbfb..bd4e69309 100755 --- a/test/envparsing.sh +++ b/test/envparsing.sh @@ -12,6 +12,10 @@ EXPECT=$(cat << "EOF" "accounts-registration-open": true, "advanced-cookies-samesite": "strict", "advanced-csp-extra-uris": [], + "advanced-rate-limit-exceptions": [ + "192.0.2.0/24", + "127.0.0.1/32" + ], "advanced-rate-limit-requests": 6969, "advanced-sender-multiplier": -1, "advanced-throttling-multiplier": -1, @@ -237,6 +241,7 @@ GTS_SYSLOG_PROTOCOL='udp' \ GTS_SYSLOG_ADDRESS='127.0.0.1:6969' \ GTS_TRACING_ENDPOINT='localhost:4317' \ GTS_ADVANCED_COOKIES_SAMESITE='strict' \ +GTS_ADVANCED_RATE_LIMIT_EXCEPTIONS="192.0.2.0/24,127.0.0.1/32" \ GTS_ADVANCED_RATE_LIMIT_REQUESTS=6969 \ GTS_ADVANCED_SENDER_MULTIPLIER=-1 \ GTS_ADVANCED_THROTTLING_MULTIPLIER=-1 \