mirror of
https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git
synced 2025-10-13 20:11:19 -04:00
b512e242e8
Implement better client IP per rendezvous method tracking for clients Add tests for added code, fix existing tests chore(deps): update module github.com/miekg/dns to v1.1.58 Implement better client IP tracking for http and ampcache Add tests for added code, fix existing tests Implement GetCandidateAddrs from SDP Add getting client IP for SQS Bug fixes Bug fix for tests
78 lines
2.7 KiB
Go
78 lines
2.7 KiB
Go
package main
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import (
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"log"
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"net/http"
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"strings"
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"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/amp"
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"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/messages"
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"gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake/v2/common/util"
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)
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// ampClientOffers is the AMP-speaking endpoint for client poll messages,
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// intended for access via an AMP cache. In contrast to the other clientOffers,
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// the client's encoded poll message is stored in the URL path rather than the
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// HTTP request body (because an AMP cache does not support POST), and the
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// encoded client poll response is sent back as AMP-armored HTML.
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func ampClientOffers(i *IPC, w http.ResponseWriter, r *http.Request) {
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// The encoded client poll message immediately follows the /amp/client/
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// path prefix, so this function unfortunately needs to be aware of and
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// remote its own routing prefix.
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path := strings.TrimPrefix(r.URL.Path, "/amp/client/")
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if path == r.URL.Path {
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// The path didn't start with the expected prefix. This probably
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// indicates an internal bug.
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log.Println("ampClientOffers: unexpected prefix in path")
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w.WriteHeader(http.StatusInternalServerError)
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return
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}
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var encPollReq []byte
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var response []byte
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var err error
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encPollReq, err = amp.DecodePath(path)
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if err == nil {
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arg := messages.Arg{
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Body: encPollReq,
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RemoteAddr: util.GetClientIp(r),
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RendezvousMethod: messages.RendezvousAmpCache,
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}
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err = i.ClientOffers(arg, &response)
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} else {
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response, err = (&messages.ClientPollResponse{
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Error: "cannot decode URL path",
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}).EncodePollResponse()
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}
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if err != nil {
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// We couldn't even construct a JSON object containing an error
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// message :( Nothing to do but signal an error at the HTTP
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// layer. The AMP cache will translate this 500 status into a
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// 404 status.
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// https://amp.dev/documentation/guides-and-tutorials/learn/amp-caches-and-cors/amp-cache-urls/#redirect-%26-error-handling
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log.Printf("ampClientOffers: %v", err)
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w.WriteHeader(http.StatusInternalServerError)
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return
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}
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w.Header().Set("Content-Type", "text/html")
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// Attempt to hint to an AMP cache not to waste resources caching this
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// document. "The Google AMP Cache considers any document fresh for at
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// least 15 seconds."
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// https://developers.google.com/amp/cache/overview#google-amp-cache-updates
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w.Header().Set("Cache-Control", "max-age=15")
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w.WriteHeader(http.StatusOK)
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enc, err := amp.NewArmorEncoder(w)
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if err != nil {
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log.Printf("amp.NewArmorEncoder: %v", err)
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return
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}
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defer enc.Close()
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if _, err := enc.Write(response); err != nil {
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log.Printf("ampClientOffers: unable to write answer: %v", err)
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}
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}
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