Changeset 705 in code for trunk/user.go

Timestamp:

Nov 17, 2021, 2:07:58 PM (4 years ago)

Author:

contact

Message:

Add per-user IP addresses

The new upstream-user-ip directive allows bouncer operators to
assign one IP address per user.

File:

• trunk/user.go (modified) (2 diffs)

trunk/user.go

@@ -7 +7 @@
         "encoding/hex"
         "fmt"
+        "math/big"
+        "net"
         "time"
 
@@ -957 +959 @@
         return !isMem
 }
+
+// localAddrForHost returns the local address to use when connecting to host.
+// A nil address is returned when the OS should automatically pick one.
+func (u *user) localTCPAddrForHost(host string) (*net.TCPAddr, error) {
+        upstreamUserIPs := u.srv.Config().UpstreamUserIPs
+        if len(upstreamUserIPs) == 0 {
+                return nil, nil
+        }
+
+        ips, err := net.LookupIP(host)
+        if err != nil {
+                return nil, err
+        }
+
+        wantIPv6 := false
+        for _, ip := range ips {
+                if ip.To4() == nil {
+                        wantIPv6 = true
+                        break
+                }
+        }
+
+        var ipNet *net.IPNet
+        for _, in := range upstreamUserIPs {
+                if wantIPv6 == (in.IP.To4() == nil) {
+                        ipNet = in
+                        break
+                }
+        }
+        if ipNet == nil {
+                return nil, nil
+        }
+
+        var ipInt big.Int
+        ipInt.SetBytes(ipNet.IP)
+        ipInt.Add(&ipInt, big.NewInt(u.ID+1))
+        ip := net.IP(ipInt.Bytes())
+        if !ipNet.Contains(ip) {
+                return nil, fmt.Errorf("IP network %v too small", ipNet)
+        }
+
+        return &net.TCPAddr{IP: ip}, nil
+}