mirror of
https://github.com/zhigang1992/cow.git
synced 2026-01-12 17:12:57 +08:00
127 lines
3.0 KiB
Go
127 lines
3.0 KiB
Go
package main
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import (
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"bufio"
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"bytes"
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"fmt"
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"os"
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"text/template"
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"time"
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)
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var errPageRawTmpl = `<!DOCTYPE html>
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<html>
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<head> <title>Proxy error</title> </head>
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<body>
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<h1>[Error] {{.H1}}</h1>
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{{.Msg}}
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{{.Form}}
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<hr />
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Generated by <i>cow-proxy</i> at {{.T}}
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</body>
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</html>
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`
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// Use GET to simplify form processing. Strictly speaking, this has side
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// effects and should use POST.
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var blockedFormRawTmpl = `<p></p>
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<form action="http://{{.ListenAddr}}/blocked" method="get">
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<input type="hidden" name="uri" value={{.RequestURI}}>
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<b>Refresh to retry</b> or
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<input type="submit" name="add" value="Add {{.Domain}} to blocked sites">
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</form>
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`
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// Do not end with "\r\n" so we can add more header later
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var headRawTmpl = "HTTP/1.1 {{.CodeReason}}\r\n" +
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"Connection: keep-alive\r\n" +
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"Cache-Control: no-cache\r\n" +
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"Pragma: no-cache\r\n" +
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"Content-Type: text/html\r\n" +
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"Content-Length: {{.Length}}\r\n"
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var errPageTmpl, headTmpl, blockedFormTmpl *template.Template
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func init() {
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var err error
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if headTmpl, err = template.New("errorHead").Parse(headRawTmpl); err != nil {
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fmt.Println("Internal error on generating error head template")
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os.Exit(1)
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}
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if errPageTmpl, err = template.New("errorPage").Parse(errPageRawTmpl); err != nil {
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fmt.Println("Internal error on generating error page template")
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os.Exit(1)
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}
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if blockedFormTmpl, err = template.New("blockedForm").Parse(blockedFormRawTmpl); err != nil {
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fmt.Println("Internal error on generating blocked form template")
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os.Exit(1)
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}
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}
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func genErrorPage(h1, msg, form string) (string, error) {
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var err error
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data := struct {
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H1 string
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Msg string
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Form string
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T string
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}{
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h1,
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msg,
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form,
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time.Now().Format(time.ANSIC),
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}
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buf := new(bytes.Buffer)
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err = errPageTmpl.Execute(buf, data)
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return buf.String(), err
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}
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func sendErrorPageGeneric(w *bufio.Writer, errCodeReason, h1, msg, form string) {
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page, err := genErrorPage(h1, msg, form)
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if err != nil {
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errl.Println("Error generating error page:", err)
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return
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}
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data := struct {
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CodeReason string
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Length int
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}{
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errCodeReason,
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len(page),
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}
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buf := new(bytes.Buffer)
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if err := headTmpl.Execute(buf, data); err != nil {
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errl.Println("Error generating error page header:", err)
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return
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}
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w.WriteString(buf.String())
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w.WriteString("\r\n")
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w.WriteString(page)
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w.Flush()
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}
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func sendErrorPage(w *bufio.Writer, errCodeReason, errMsg, detailedMsg string) {
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sendErrorPageGeneric(w, errCodeReason, errMsg, detailedMsg, "")
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}
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func sendBlockedErrorPage(w *bufio.Writer, errCodeReason, errMsg, detailedMsg string, r *Request) {
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data := struct {
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ListenAddr string
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RequestURI string
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Domain string
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}{
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config.listenAddr,
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r.URL.toURI(), // escape URI to put it in request url
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requestDomain(r),
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}
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buf := new(bytes.Buffer)
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if err := blockedFormTmpl.Execute(buf, data); err != nil {
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errl.Println("Error generating blocked form:", err)
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return
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}
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sendErrorPageGeneric(w, errCodeReason, errMsg, detailedMsg, buf.String())
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}
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