87 lines
2.3 KiB
Go
87 lines
2.3 KiB
Go
package middlewares
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"net/http"
|
|
|
|
"github.com/containous/traefik/log"
|
|
"github.com/pkg/errors"
|
|
"github.com/urfave/negroni"
|
|
)
|
|
|
|
// IPWhitelister is a middleware that provides Checks of the Requesting IP against a set of Whitelists
|
|
type IPWhitelister struct {
|
|
handler negroni.Handler
|
|
whitelists []*net.IPNet
|
|
}
|
|
|
|
// NewIPWhitelister builds a new IPWhitelister given a list of CIDR-Strings to whitelist
|
|
func NewIPWhitelister(whitelistStrings []string) (*IPWhitelister, error) {
|
|
|
|
if len(whitelistStrings) == 0 {
|
|
return nil, errors.New("no whitelists provided")
|
|
}
|
|
|
|
whitelister := IPWhitelister{}
|
|
|
|
for _, whitelistString := range whitelistStrings {
|
|
_, whitelist, err := net.ParseCIDR(whitelistString)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("parsing CIDR whitelist %s: %v", whitelist, err)
|
|
}
|
|
whitelister.whitelists = append(whitelister.whitelists, whitelist)
|
|
}
|
|
|
|
whitelister.handler = negroni.HandlerFunc(whitelister.handle)
|
|
log.Debugf("configured %u IP whitelists: %s", len(whitelister.whitelists), whitelister.whitelists)
|
|
|
|
return &whitelister, nil
|
|
}
|
|
|
|
func (whitelister *IPWhitelister) handle(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
|
|
remoteIP, err := ipFromRemoteAddr(r.RemoteAddr)
|
|
if err != nil {
|
|
log.Warnf("unable to parse remote-address from header: %s - rejecting", r.RemoteAddr)
|
|
reject(w)
|
|
return
|
|
}
|
|
|
|
for _, whitelist := range whitelister.whitelists {
|
|
if whitelist.Contains(*remoteIP) {
|
|
log.Debugf("source-IP %s matched whitelist %s - passing", remoteIP, whitelist)
|
|
next.ServeHTTP(w, r)
|
|
return
|
|
}
|
|
}
|
|
|
|
log.Debugf("source-IP %s matched none of the whitelists - rejecting", remoteIP)
|
|
reject(w)
|
|
return
|
|
}
|
|
|
|
func reject(w http.ResponseWriter) {
|
|
statusCode := http.StatusForbidden
|
|
|
|
w.WriteHeader(statusCode)
|
|
w.Write([]byte(http.StatusText(statusCode)))
|
|
}
|
|
|
|
func ipFromRemoteAddr(addr string) (*net.IP, error) {
|
|
ip, _, err := net.SplitHostPort(addr)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("can't extract IP/Port from address %s: %s", addr, err)
|
|
}
|
|
|
|
userIP := net.ParseIP(ip)
|
|
if userIP == nil {
|
|
return nil, fmt.Errorf("can't parse IP from address %s", ip)
|
|
}
|
|
|
|
return &userIP, nil
|
|
}
|
|
|
|
func (whitelister *IPWhitelister) ServeHTTP(rw http.ResponseWriter, r *http.Request, next http.HandlerFunc) {
|
|
whitelister.handler.ServeHTTP(rw, r, next)
|
|
}
|