[chore] add IPPrefixes type so we don't need separate rate limit parsed field (#3982)

* add IPPrefixes type so we don't need separate rate limit parsed field

* sshhhh please linter, mommy's working

10 files changed, 82 insertions, 71 deletions

diff --git a/cmd/gotosocial/action/server/server.go b/cmd/gotosocial/action/server/server.go
index f934aaadd..4caf44cad 100644
--- a/cmd/gotosocial/action/server/server.go
+++ b/cmd/gotosocial/action/server/server.go
@@ -530,10 +530,11 @@ var Start action.GTSAction = func(ctx context.Context) error {
 	// Create per-route / per-grouping middlewares.
 	// rate limiting
 	rlLimit := config.GetAdvancedRateLimitRequests()
-	clLimit := middleware.RateLimit(rlLimit, config.GetAdvancedRateLimitExceptionsParsed())        // client api
-	s2sLimit := middleware.RateLimit(rlLimit, config.GetAdvancedRateLimitExceptionsParsed())       // server-to-server (AP)
-	fsMainLimit := middleware.RateLimit(rlLimit, config.GetAdvancedRateLimitExceptionsParsed())    // fileserver / web templates
-	fsEmojiLimit := middleware.RateLimit(rlLimit*2, config.GetAdvancedRateLimitExceptionsParsed()) // fileserver (emojis only, use high limit)
+	exceptions := config.GetAdvancedRateLimitExceptions()
+	clLimit := middleware.RateLimit(rlLimit, exceptions)        // client api
+	s2sLimit := middleware.RateLimit(rlLimit, exceptions)       // server-to-server (AP)
+	fsMainLimit := middleware.RateLimit(rlLimit, exceptions)    // fileserver / web templates
+	fsEmojiLimit := middleware.RateLimit(rlLimit*2, exceptions) // fileserver (emojis only, use high limit)
 
 	// throttling
 	cpuMultiplier := config.GetAdvancedThrottlingMultiplier()
diff --git a/internal/api/util/template.go b/internal/api/util/template.go
index 38e79484f..86d179cdc 100644
--- a/internal/api/util/template.go
+++ b/internal/api/util/template.go
@@ -171,7 +171,7 @@ func injectTrustedProxiesRec(
 		return
 	}
 
-	except := config.GetAdvancedRateLimitExceptionsParsed()
+	except := config.GetAdvancedRateLimitExceptions()
 	for _, prefix := range except {
 		if prefix.Contains(ip) {
 			// This ip is exempt from
diff --git a/internal/config/config.go b/internal/config/config.go
index 8ce2105b4..d4b3901e7 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -18,7 +18,6 @@
 package config
 
 import (
-	"net/netip"
 	"reflect"
 	"time"
 
@@ -168,15 +167,14 @@ type Configuration struct {
 	SyslogProtocol string `name:"syslog-protocol" usage:"Protocol to use when directing logs to syslog. Leave empty to connect to local syslog."`
 	SyslogAddress  string `name:"syslog-address" usage:"Address:port to send syslog logs to. Leave empty to connect to local syslog."`
 
-	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."`
-	AdvancedRateLimitExceptionsParsed []netip.Prefix `name:"advanced-rate-limit-exceptions-parsed"`
-	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)."`
-	AdvancedCSPExtraURIs              []string       `name:"advanced-csp-extra-uris" usage:"Additional URIs to allow when building content-security-policy for media + images."`
-	AdvancedHeaderFilterMode          string         `name:"advanced-header-filter-mode" usage:"Set incoming request header filtering mode."`
+	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  IPPrefixes    `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)."`
+	AdvancedCSPExtraURIs         []string      `name:"advanced-csp-extra-uris" usage:"Additional URIs to allow when building content-security-policy for media + images."`
+	AdvancedHeaderFilterMode     string        `name:"advanced-header-filter-mode" usage:"Set incoming request header filtering mode."`
 
 	// HTTPClient configuration vars.
 	HTTPClient HTTPClientConfiguration `name:"http-client"`
diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index 78a8230d5..9a507b421 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -136,7 +136,7 @@ var Defaults = Configuration{
 
 	AdvancedCookiesSamesite:      "lax",
 	AdvancedRateLimitRequests:    300, // 1 per second per 5 minutes
-	AdvancedRateLimitExceptions:  []string{},
+	AdvancedRateLimitExceptions:  IPPrefixes{},
 	AdvancedThrottlingMultiplier: 8, // 8 open requests per CPU
 	AdvancedThrottlingRetryAfter: time.Second * 30,
 	AdvancedSenderMultiplier:     2, // 2 senders per CPU
diff --git a/internal/config/flags.go b/internal/config/flags.go
index 3a2564c94..eaf16990c 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -156,7 +156,7 @@ 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().StringSlice(AdvancedRateLimitExceptionsFlag(), cfg.AdvancedRateLimitExceptions.Strings(), 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/gen/gen.go b/internal/config/gen/gen.go
index a3742ee15..9130f8606 100644
--- a/internal/config/gen/gen.go
+++ b/internal/config/gen/gen.go
@@ -65,7 +65,6 @@ func main() {
 	fmt.Fprint(output, license)
 	fmt.Fprint(output, "package config\n\n")
 	fmt.Fprint(output, "import (\n")
-	fmt.Fprint(output, "\t\"net/netip\"\n")
 	fmt.Fprint(output, "\t\"time\"\n\n")
 	fmt.Fprint(output, "\t\"codeberg.org/gruf/go-bytesize\"\n")
 	fmt.Fprint(output, "\t\"github.com/superseriousbusiness/gotosocial/internal/language\"\n")
diff --git a/internal/config/helpers.gen.go b/internal/config/helpers.gen.go
index 156c19fd5..ac41a73e9 100644
--- a/internal/config/helpers.gen.go
+++ b/internal/config/helpers.gen.go
@@ -19,7 +19,6 @@
 package config
 
 import (
-	"net/netip"
 	"time"
 
 	"codeberg.org/gruf/go-bytesize"
@@ -2758,7 +2757,7 @@ func GetAdvancedRateLimitRequests() int { return global.GetAdvancedRateLimitRequ
 func SetAdvancedRateLimitRequests(v int) { global.SetAdvancedRateLimitRequests(v) }
 
 // GetAdvancedRateLimitExceptions safely fetches the Configuration value for state's 'AdvancedRateLimitExceptions' field
-func (st *ConfigState) GetAdvancedRateLimitExceptions() (v []string) {
+func (st *ConfigState) GetAdvancedRateLimitExceptions() (v IPPrefixes) {
 	st.mutex.RLock()
 	v = st.config.AdvancedRateLimitExceptions
 	st.mutex.RUnlock()
@@ -2766,7 +2765,7 @@ func (st *ConfigState) GetAdvancedRateLimitExceptions() (v []string) {
 }
 
 // SetAdvancedRateLimitExceptions safely sets the Configuration value for state's 'AdvancedRateLimitExceptions' field
-func (st *ConfigState) SetAdvancedRateLimitExceptions(v []string) {
+func (st *ConfigState) SetAdvancedRateLimitExceptions(v IPPrefixes) {
 	st.mutex.Lock()
 	defer st.mutex.Unlock()
 	st.config.AdvancedRateLimitExceptions = v
@@ -2777,39 +2776,10 @@ func (st *ConfigState) SetAdvancedRateLimitExceptions(v []string) {
 func AdvancedRateLimitExceptionsFlag() string { return "advanced-rate-limit-exceptions" }
 
 // GetAdvancedRateLimitExceptions safely fetches the value for global configuration 'AdvancedRateLimitExceptions' field
-func GetAdvancedRateLimitExceptions() []string { return global.GetAdvancedRateLimitExceptions() }
+func GetAdvancedRateLimitExceptions() IPPrefixes { return global.GetAdvancedRateLimitExceptions() }
 
 // SetAdvancedRateLimitExceptions safely sets the value for global configuration 'AdvancedRateLimitExceptions' field
-func SetAdvancedRateLimitExceptions(v []string) { global.SetAdvancedRateLimitExceptions(v) }
-
-// GetAdvancedRateLimitExceptionsParsed safely fetches the Configuration value for state's 'AdvancedRateLimitExceptionsParsed' field
-func (st *ConfigState) GetAdvancedRateLimitExceptionsParsed() (v []netip.Prefix) {
-	st.mutex.RLock()
-	v = st.config.AdvancedRateLimitExceptionsParsed
-	st.mutex.RUnlock()
-	return
-}
-
-// SetAdvancedRateLimitExceptionsParsed safely sets the Configuration value for state's 'AdvancedRateLimitExceptionsParsed' field
-func (st *ConfigState) SetAdvancedRateLimitExceptionsParsed(v []netip.Prefix) {
-	st.mutex.Lock()
-	defer st.mutex.Unlock()
-	st.config.AdvancedRateLimitExceptionsParsed = v
-	st.reloadToViper()
-}
-
-// AdvancedRateLimitExceptionsParsedFlag returns the flag name for the 'AdvancedRateLimitExceptionsParsed' field
-func AdvancedRateLimitExceptionsParsedFlag() string { return "advanced-rate-limit-exceptions-parsed" }
-
-// GetAdvancedRateLimitExceptionsParsed safely fetches the value for global configuration 'AdvancedRateLimitExceptionsParsed' field
-func GetAdvancedRateLimitExceptionsParsed() []netip.Prefix {
-	return global.GetAdvancedRateLimitExceptionsParsed()
-}
-
-// SetAdvancedRateLimitExceptionsParsed safely sets the value for global configuration 'AdvancedRateLimitExceptionsParsed' field
-func SetAdvancedRateLimitExceptionsParsed(v []netip.Prefix) {
-	global.SetAdvancedRateLimitExceptionsParsed(v)
-}
+func SetAdvancedRateLimitExceptions(v IPPrefixes) { global.SetAdvancedRateLimitExceptions(v) }
 
 // GetAdvancedThrottlingMultiplier safely fetches the Configuration value for state's 'AdvancedThrottlingMultiplier' field
 func (st *ConfigState) GetAdvancedThrottlingMultiplier() (v int) {
diff --git a/internal/config/types.go b/internal/config/types.go
new file mode 100644
index 000000000..c2296975f
--- /dev/null
+++ b/internal/config/types.go
@@ -0,0 +1,62 @@
+// 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 <http://www.gnu.org/licenses/>.
+
+package config
+
+import (
+	"net/netip"
+
+	"codeberg.org/gruf/go-byteutil"
+)
+
+// IPPrefixes is a type-alias for []netip.Prefix
+// to allow parsing by CLI "flag"-like utilities.
+type IPPrefixes []netip.Prefix
+
+func (p *IPPrefixes) Set(in string) error {
+	prefix, err := netip.ParsePrefix(in)
+	if err != nil {
+		return err
+	}
+	(*p) = append((*p), prefix)
+	return nil
+}
+
+func (p *IPPrefixes) String() string {
+	if p == nil || len(*p) == 0 {
+		return ""
+	}
+	var buf byteutil.Buffer
+	for _, prefix := range *p {
+		str := prefix.String()
+		buf.B = append(buf.B, str...)
+		buf.B = append(buf.B, ',')
+	}
+	buf.Truncate(1)
+	return buf.String()
+}
+
+func (p *IPPrefixes) Strings() []string {
+	if p == nil || len(*p) == 0 {
+		return nil
+	}
+	strs := make([]string, len(*p))
+	for i, prefix := range *p {
+		strs[i] = prefix.String()
+	}
+	return strs
+}
diff --git a/internal/config/validate.go b/internal/config/validate.go
index a4ed08106..d36d18ba4 100644
--- a/internal/config/validate.go
+++ b/internal/config/validate.go
@@ -19,7 +19,6 @@ package config
 
 import (
 	"fmt"
-	"net/netip"
 	"net/url"
 	"strings"
 
@@ -182,22 +181,5 @@ func Validate() error {
 		)
 	}
 
-	// Parse `advanced-rate-limit-exceptions` and set
-	// parsed versions on config to avoid reparsing calls.
-	rles := GetAdvancedRateLimitExceptions()
-	rlesParsed := make([]netip.Prefix, 0, len(rles))
-	for _, rle := range rles {
-		parsed, err := netip.ParsePrefix(rle)
-		if err != nil {
-			errf(
-				"invalid entry %s in %s: %w",
-				rle, AdvancedRateLimitExceptionsFlag(), err,
-			)
-			continue
-		}
-		rlesParsed = append(rlesParsed, parsed)
-	}
-	SetAdvancedRateLimitExceptionsParsed(rlesParsed)
-
 	return errs.Combine()
 }
diff --git a/test/envparsing.sh b/test/envparsing.sh
index fc6afbcc2..66295f1f6 100755
--- a/test/envparsing.sh
+++ b/test/envparsing.sh
@@ -18,7 +18,6 @@ EXPECT=$(cat << "EOF"
         "192.0.2.0/24",
         "127.0.0.1/32"
     ],
-    "advanced-rate-limit-exceptions-parsed": null,
     "advanced-rate-limit-requests": 6969,
     "advanced-sender-multiplier": -1,
     "advanced-throttling-multiplier": -1,