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|
package vnet
import (
"errors"
"net"
"sync"
)
var (
errAddressAlreadyInUse = errors.New("address already in use")
errNoSuchUDPConn = errors.New("no such UDPConn")
errCannotRemoveUnspecifiedIP = errors.New("cannot remove unspecified IP by the specified IP")
)
type udpConnMap struct {
portMap map[int][]*UDPConn
mutex sync.RWMutex
}
func newUDPConnMap() *udpConnMap {
return &udpConnMap{
portMap: map[int][]*UDPConn{},
}
}
func (m *udpConnMap) insert(conn *UDPConn) error {
m.mutex.Lock()
defer m.mutex.Unlock()
udpAddr := conn.LocalAddr().(*net.UDPAddr)
// check if the port has a listener
conns, ok := m.portMap[udpAddr.Port]
if ok {
if udpAddr.IP.IsUnspecified() {
return errAddressAlreadyInUse
}
for _, conn := range conns {
laddr := conn.LocalAddr().(*net.UDPAddr)
if laddr.IP.IsUnspecified() || laddr.IP.Equal(udpAddr.IP) {
return errAddressAlreadyInUse
}
}
conns = append(conns, conn)
} else {
conns = []*UDPConn{conn}
}
m.portMap[udpAddr.Port] = conns
return nil
}
func (m *udpConnMap) find(addr net.Addr) (*UDPConn, bool) {
m.mutex.Lock() // could be RLock, but we have delete() op
defer m.mutex.Unlock()
udpAddr := addr.(*net.UDPAddr)
if conns, ok := m.portMap[udpAddr.Port]; ok {
if udpAddr.IP.IsUnspecified() {
// pick the first one appears in the iteration
if len(conns) == 0 {
// This can't happen!
delete(m.portMap, udpAddr.Port)
return nil, false
}
return conns[0], true
}
for _, conn := range conns {
laddr := conn.LocalAddr().(*net.UDPAddr)
if laddr.IP.IsUnspecified() || laddr.IP.Equal(udpAddr.IP) {
return conn, ok
}
}
}
return nil, false
}
func (m *udpConnMap) delete(addr net.Addr) error {
m.mutex.Lock()
defer m.mutex.Unlock()
udpAddr := addr.(*net.UDPAddr)
conns, ok := m.portMap[udpAddr.Port]
if !ok {
return errNoSuchUDPConn
}
if udpAddr.IP.IsUnspecified() {
// remove all from this port
delete(m.portMap, udpAddr.Port)
return nil
}
newConns := []*UDPConn{}
for _, conn := range conns {
laddr := conn.LocalAddr().(*net.UDPAddr)
if laddr.IP.IsUnspecified() {
// This can't happen!
return errCannotRemoveUnspecifiedIP
}
if laddr.IP.Equal(udpAddr.IP) {
continue
}
newConns = append(newConns, conn)
}
if len(newConns) == 0 {
delete(m.portMap, udpAddr.Port)
} else {
m.portMap[udpAddr.Port] = newConns
}
return nil
}
// size returns the number of UDPConns (UDP listeners)
func (m *udpConnMap) size() int {
m.mutex.RLock()
defer m.mutex.RUnlock()
n := 0
for _, conns := range m.portMap {
n += len(conns)
}
return n
}
|
