traefik/pkg/ip/strategy.go

74 lines
1.6 KiB
Go

package ip
import (
"net"
"net/http"
"strings"
)
const (
xForwardedFor = "X-Forwarded-For"
)
// Strategy a strategy for IP selection.
type Strategy interface {
GetIP(req *http.Request) string
}
// RemoteAddrStrategy a strategy that always return the remote address.
type RemoteAddrStrategy struct{}
// GetIP returns the selected IP.
func (s *RemoteAddrStrategy) GetIP(req *http.Request) string {
ip, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
return req.RemoteAddr
}
return ip
}
// DepthStrategy a strategy based on the depth inside the X-Forwarded-For from right to left.
type DepthStrategy struct {
Depth int
}
// GetIP return the selected IP.
func (s *DepthStrategy) GetIP(req *http.Request) string {
xff := req.Header.Get(xForwardedFor)
xffs := strings.Split(xff, ",")
if len(xffs) < s.Depth {
return ""
}
return strings.TrimSpace(xffs[len(xffs)-s.Depth])
}
// PoolStrategy is a strategy based on an IP Checker.
// It allows to check whether addresses are in a given pool of IPs.
type PoolStrategy struct {
Checker *Checker
}
// GetIP checks the list of Forwarded IPs (most recent first) against the
// Checker pool of IPs. It returns the first IP that is not in the pool, or the
// empty string otherwise.
func (s *PoolStrategy) GetIP(req *http.Request) string {
if s.Checker == nil {
return ""
}
xff := req.Header.Get(xForwardedFor)
xffs := strings.Split(xff, ",")
for i := len(xffs) - 1; i >= 0; i-- {
xffTrimmed := strings.TrimSpace(xffs[i])
if len(xffTrimmed) == 0 {
continue
}
if contain, _ := s.Checker.Contains(xffTrimmed); !contain {
return xffTrimmed
}
}
return ""
}