Match SIP Trunks by source IP or mask

.changeset/cuddly-buttons-guess.md

@@ -0,0 +1,5 @@
+---
+"github.com/livekit/protocol": patch
+---
+
+Match SIP Trunks by source IP or mask.

sip/sip.go

@@ -17,9 +17,11 @@ package sip
 import (
 	"fmt"
 	"math"
+	"net/netip"
 	"regexp"
 	"sort"
 	"strconv"
+	"strings"
 
 	"golang.org/x/exp/slices"
 
@@ -222,9 +224,36 @@ func ValidateTrunks(trunks []*livekit.SIPTrunkInfo) error {
 	return nil
 }
 
+func matchAddrs(addr string, mask string) bool {
+	if !strings.Contains(mask, "/") {
+		return addr == mask
+	}
+	ip, err := netip.ParseAddr(addr)
+	if err != nil {
+		return false
+	}
+	pref, err := netip.ParsePrefix(mask)
+	if err != nil {
+		return false
+	}
+	return pref.Contains(ip)
+}
+
+func matchAddr(addr string, masks []string) bool {
+	if addr == "" {
+		return true
+	}
+	for _, mask := range masks {
+		if !matchAddrs(addr, mask) {
+			return false
+		}
+	}
+	return true
+}
+
 // MatchTrunk finds a SIP Trunk definition matching the request.
 // Returns nil if no rules matched or an error if there are conflicting definitions.
-func MatchTrunk(trunks []*livekit.SIPTrunkInfo, calling, called string) (*livekit.SIPTrunkInfo, error) {
+func MatchTrunk(trunks []*livekit.SIPTrunkInfo, srcIP, calling, called string) (*livekit.SIPTrunkInfo, error) {
 	var (
 		selectedTrunk   *livekit.SIPTrunkInfo
 		defaultTrunk    *livekit.SIPTrunkInfo
@@ -235,6 +264,9 @@ func MatchTrunk(trunks []*livekit.SIPTrunkInfo, calling, called string) (*liveki
 		if len(tr.InboundNumbers) != 0 && !slices.Contains(tr.InboundNumbers, calling) {
 			continue
 		}
+		if !matchAddr(srcIP, tr.InboundAddresses) {
+			continue
+		}
 		// Deprecated, but we still check it for backward compatibility.
 		matchesRe := len(tr.InboundNumbersRegex) == 0
 		for _, reStr := range tr.InboundNumbersRegex {

sip/sip_test.go

@@ -157,7 +157,7 @@ func TestSIPMatchTrunk(t *testing.T) {
 	for _, c := range trunkCases {
 		c := c
 		t.Run(c.name, func(t *testing.T) {
-			got, err := MatchTrunk(c.trunks, sipNumber1, sipNumber2)
+			got, err := MatchTrunk(c.trunks, "", sipNumber1, sipNumber2)
 			if c.expErr {
 				require.Error(t, err)
 				require.Nil(t, got)
@@ -515,3 +515,23 @@ func TestSIPValidateDispatchRules(t *testing.T) {
 		})
 	}
 }
+
+func TestMatchIP(t *testing.T) {
+	cases := []struct {
+		addr string
+		mask string
+		exp  bool
+	}{
+		{addr: "192.168.0.10", mask: "192.168.0.10", exp: true},
+		{addr: "192.168.0.10", mask: "192.168.0.11", exp: false},
+		{addr: "192.168.0.10", mask: "192.168.0.0/24", exp: true},
+		{addr: "192.168.0.10", mask: "192.168.0.10/0", exp: true},
+		{addr: "192.168.0.10", mask: "192.170.0.0/24", exp: false},
+	}
+	for _, c := range cases {
+		t.Run(c.mask, func(t *testing.T) {
+			got := matchAddrs(c.addr, c.mask)
+			require.Equal(t, c.exp, got)
+		})
+	}
+}