140 lines
3.5 KiB
Go
140 lines
3.5 KiB
Go
package main
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import (
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"bufio"
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"errors"
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"fmt"
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"io"
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"net/http"
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"os"
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"path"
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"runtime"
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"strings"
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)
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func clamp(value, low, high int) int {
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if value < low {
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return low
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}
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if value > high {
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return high
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}
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return value
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}
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// ----------------------------------
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// helper functions for HTTP handlers
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// ----------------------------------
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func ensure(method string, handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return func(w http.ResponseWriter, r *http.Request) {
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if r.Method != method {
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http.Error(w, "This request must be "+method, 405)
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return
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}
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handler(w, r)
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}
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}
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func ensurePOST(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return ensure("POST", handler)
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}
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func ensureGET(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return ensure("GET", handler)
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}
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func ensurePUT(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return ensure("PUT", handler)
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}
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func ensureDELETE(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return ensure("DELETE", handler)
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}
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func optionalAuth(handler func(http.ResponseWriter, *http.Request)) func(http.ResponseWriter, *http.Request) {
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return func(w http.ResponseWriter, r *http.Request) {
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if config.AuthName == "" || config.AuthPass == "" {
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handler(w, r)
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return
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}
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user, pass, ok := r.BasicAuth()
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if !ok || user != config.AuthName || pass != config.AuthPass {
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w.Header().Set("WWW-Authenticate", `Basic realm="dnsfilter"`)
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w.WriteHeader(http.StatusUnauthorized)
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w.Write([]byte("Unauthorised.\n"))
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return
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}
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handler(w, r)
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}
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}
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type authHandler struct {
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handler http.Handler
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}
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func (a *authHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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if config.AuthName == "" || config.AuthPass == "" {
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a.handler.ServeHTTP(w, r)
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return
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}
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user, pass, ok := r.BasicAuth()
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if !ok || user != config.AuthName || pass != config.AuthPass {
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w.Header().Set("WWW-Authenticate", `Basic realm="dnsfilter"`)
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w.WriteHeader(http.StatusUnauthorized)
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w.Write([]byte("Unauthorised.\n"))
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return
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}
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a.handler.ServeHTTP(w, r)
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}
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func optionalAuthHandler(handler http.Handler) http.Handler {
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return &authHandler{handler}
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}
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// -------------------------------------------------
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// helper functions for parsing parameters from body
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// -------------------------------------------------
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func parseParametersFromBody(r io.Reader) (map[string]string, error) {
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parameters := map[string]string{}
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scanner := bufio.NewScanner(r)
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for scanner.Scan() {
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line := scanner.Text()
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if len(line) == 0 {
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// skip empty lines
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continue
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}
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parts := strings.SplitN(line, "=", 2)
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if len(parts) != 2 {
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return parameters, errors.New("Got invalid request body")
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}
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parameters[strings.TrimSpace(parts[0])] = strings.TrimSpace(parts[1])
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}
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return parameters, nil
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}
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// ---------------------
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// debug logging helpers
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// ---------------------
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func _Func() string {
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pc := make([]uintptr, 10) // at least 1 entry needed
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runtime.Callers(2, pc)
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f := runtime.FuncForPC(pc[0])
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return path.Base(f.Name())
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}
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func trace(format string, args ...interface{}) {
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pc := make([]uintptr, 10) // at least 1 entry needed
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runtime.Callers(2, pc)
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f := runtime.FuncForPC(pc[0])
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var buf strings.Builder
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buf.WriteString(fmt.Sprintf("%s(): ", path.Base(f.Name())))
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text := fmt.Sprintf(format, args...)
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buf.WriteString(text)
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if len(text) == 0 || text[len(text)-1] != '\n' {
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buf.WriteRune('\n')
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}
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fmt.Fprint(os.Stderr, buf.String())
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}
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