core/limiter/wrapper/conn.go
2022-09-05 10:57:07 +08:00

131 lines
2.2 KiB
Go

package wrapper
import (
"bytes"
"errors"
"net"
"syscall"
"github.com/go-gost/core/limiter"
)
var (
errUnsupport = errors.New("unsupported operation")
)
// serverConn is a server side Conn with metrics supported.
type serverConn struct {
net.Conn
rlimiter limiter.RateLimiter
rbuf bytes.Buffer
}
func WrapConn(rlimiter limiter.RateLimiter, c net.Conn) net.Conn {
if rlimiter == nil {
return c
}
return &serverConn{
Conn: c,
rlimiter: rlimiter,
}
}
func (c *serverConn) Read(b []byte) (n int, err error) {
if c.rlimiter == nil || c.rlimiter.Input() == nil {
return c.Conn.Read(b)
}
burst := len(b)
if c.rbuf.Len() > 0 {
if c.rbuf.Len() < burst {
burst = c.rbuf.Len()
}
return c.rbuf.Read(b[:c.rlimiter.Input().Limit(burst)])
}
nn, err := c.Conn.Read(b)
if err != nil {
return nn, err
}
n = c.rlimiter.Input().Limit(nn)
if n < nn {
if _, err = c.rbuf.Write(b[n:nn]); err != nil {
return 0, err
}
}
return
}
func (c *serverConn) Write(b []byte) (n int, err error) {
if c.rlimiter == nil || c.rlimiter.Output() == nil {
return c.Conn.Write(b)
}
nn := 0
for len(b) > 0 {
nn, err = c.Conn.Write(b[:c.rlimiter.Output().Limit(len(b))])
n += nn
if err != nil {
return
}
b = b[nn:]
}
return
}
func (c *serverConn) SyscallConn() (rc syscall.RawConn, err error) {
if sc, ok := c.Conn.(syscall.Conn); ok {
rc, err = sc.SyscallConn()
return
}
err = errUnsupport
return
}
type packetConn struct {
net.PacketConn
rlimiter limiter.RateLimiter
}
func WrapPacketConn(rlimiter limiter.RateLimiter, pc net.PacketConn) net.PacketConn {
if rlimiter == nil {
return pc
}
return &packetConn{
PacketConn: pc,
rlimiter: rlimiter,
}
}
func (c *packetConn) ReadFrom(p []byte) (n int, addr net.Addr, err error) {
for {
n, addr, err = c.PacketConn.ReadFrom(p)
if err != nil {
return
}
if c.rlimiter == nil || c.rlimiter.Input() == nil {
return
}
if c.rlimiter.Input().Limit(n) < n {
continue
}
return
}
}
func (c *packetConn) WriteTo(p []byte, addr net.Addr) (n int, err error) {
if c.rlimiter != nil &&
c.rlimiter.Output() != nil &&
c.rlimiter.Output().Limit(len(p)) < len(p) {
n = len(p)
return
}
return c.PacketConn.WriteTo(p, addr)
}