/*
Copyright (c) 2019 Ben Morrison (gbmor)
This file is part of Getwtxt.
Getwtxt is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Getwtxt is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with Getwtxt. If not, see <https://www.gnu.org/licenses/>.
*/
package svc // import "git.sr.ht/~gbmor/getwtxt/svc"
import (
"context"
"fmt"
"log"
"net"
"net/http"
"strings"
)
// content-type consts
const txtutf8 = "text/plain; charset=utf-8"
const htmlutf8 = "text/html; charset=utf-8"
const cssutf8 = "text/css; charset=utf-8"
// ipCtxKey is the Context value key for user IP addresses
type ipCtxKey int
const ctxKey ipCtxKey = iota
// Attaches a request's IP address to the request's context.
// If getwtxt is behind a reverse proxy, get the last entry
// in the X-Forwarded-For or X-Real-IP HTTP header as the user IP.
func newCtxUserIP(ctx context.Context, r *http.Request) context.Context {
base := strings.Split(r.RemoteAddr, ":")
uip := base[0]
if _, ok := r.Header["X-Forwarded-For"]; ok {
proxied := r.Header["X-Forwarded-For"]
base = strings.Split(proxied[len(proxied)-1], ":")
uip = base[0]
}
xRealIP := http.CanonicalHeaderKey("X-Real-IP")
if _, ok := r.Header[xRealIP]; ok {
proxied := r.Header[xRealIP]
base = strings.Split(proxied[len(proxied)-1], ":")
uip = base[0]
}
return context.WithValue(ctx, ctxKey, uip)
}
// Retrieves a request's IP address from the request's context
func getIPFromCtx(ctx context.Context) net.IP {
uip, ok := ctx.Value(ctxKey).(string)
if !ok {
log.Printf("Couldn't retrieve IP from request\n")
}
return net.ParseIP(uip)
}
// Shim function to modify/pass context value to a handler
func ipMiddleware(hop http.Handler) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
ctx := newCtxUserIP(r.Context(), r)
hop.ServeHTTP(w, r.WithContext(ctx))
})
}
// Appends a 200 OK to the request log
func log200(r *http.Request) {
useragent := r.Header["User-Agent"]
uip := getIPFromCtx(r.Context())
reqLog.Printf("*** %v :: 200 :: %v %v :: %v\n", uip, r.Method, r.URL, useragent)
}
// Appends a request of a given status code to the request
// log. Intended for errors.
func errHTTP(w http.ResponseWriter, r *http.Request, err error, code int) {
useragent := r.Header["User-Agent"]
uip := getIPFromCtx(r.Context())
reqLog.Printf("*** %v :: %v :: %v %v :: %v :: %v\n", uip, code, r.Method, r.URL, useragent, err.Error())
http.Error(w, fmt.Sprintf("Error %v: %v", code, err.Error()), code)
}